Two-step solar filament eruptions

NASA Astrophysics Data System (ADS)

Filippov, B.

2018-04-01

Coronal mass ejections (CMEs) are closely related to eruptive filaments and usually are the continuation of the same eruptive process into the upper corona. There are failed filament eruptions when a filament decelerates and stops at some greater height in the corona. Sometimes the filament after several hours starts to rise again and develops into the successful eruption with a CME formation. We propose a simple model for the interpretation of such two-step eruptions in terms of equilibrium of a flux rope in a two-scale ambient magnetic field. The eruption is caused by a slow decrease of the holding magnetic field. The presence of two critical heights for the initiation of the flux-rope vertical instability allows the flux rope to stay after the first jump some time in a metastable equilibrium near the second critical height. If the decrease of the ambient field continues, the next eruption step follows.

Critical Constructivism: Interpreting Mathematics Education for Social Justice

ERIC Educational Resources Information Center

Skovsmose, Ole

2018-01-01

The notion of social justice has been addressed from the perspective of 'ethical realism' and 'ethical anarchistic'. Here, however, the possibility of 'ethical constructivism' becomes formulated. With departure in Rawls' description of an idealised meeting defining social justice, the initial steps into ethical constructivism become taken.…

Interrupting Situated Practices: Critical Incidents in International Partnerships

ERIC Educational Resources Information Center

Flint, Amy Seely; Albers, Peggy; Matthews, Mona

2018-01-01

This paper examines the initial steps of an internationally funded project focused on enhancing teachers' conceptual and pedagogical knowledge of literacy development in the Western Cape of South Africa. We asked what are the tensions and breakthroughs when engaged in international teacher professional development? Four lines of inquiry support…

Real time detection of ESKAPE pathogens by a nitroreductase-triggered fluorescence turn-on probe.

PubMed

Xu, Shengnan; Wang, Qinghua; Zhang, Qingyang; Zhang, Leilei; Zuo, Limin; Jiang, Jian-Dong; Hu, Hai-Yu

2017-10-18

The identification of bacterial pathogens is the critical first step in conquering infection diseases. A novel turn-on fluorescent probe for the selective sensing of nitroreductase (NTR) activity and its initial applications in rapid, real-time detection and identification of ESKAPE pathogens have been reported.

Initiating Formal Requirements Specifications with Object-Oriented Models

NASA Technical Reports Server (NTRS)

Ampo, Yoko; Lutz, Robyn R.

1994-01-01

This paper reports results of an investigation into the suitability of object-oriented models as an initial step in developing formal specifications. The requirements for two critical system-level software modules were used as target applications. It was found that creating object-oriented diagrams prior to formally specifying the requirements enhanced the accuracy of the initial formal specifications and reduced the effort required to produce them. However, the formal specifications incorporated some information not found in the object-oriented diagrams, such as higher-level strategy or goals of the software.

Initial growth and topography of 4,4'-biphenyldicarboxylic acid on Cu(001)

NASA Astrophysics Data System (ADS)

Poelsema, Bene; Schwarz, Daniel; van Gastel, Raoul; Zandvliet, Harold J. W.

2013-03-01

We have investigated nucleation and initial growth of BDA on Cu(001) at 300 - 410K, using LEEM and μLEED. BDA condenses in a 2D supramolecular c(8 ×8) network of lying molecules. The dehydrogenated molecules form hydrogen bonds with perpendicular adjacent ones. First, the adsorbed BDA molecules form a disordered dilute phase and at a sufficiently high density, the c(8 ×8) crystalline phase nucleates. From the equilibrium densities at different temperatures we obtain the 2D phase diagram. The phase coexistence line provides a cohesive energy of 0.35 eV. LEEM allows a detailed study of nucleation and growth of BDA on Cu(001) at low supersaturation. The real time microscopic information allows a direct visualization of near-critical nuclei. At 332 K and a deposition rate of 1.4 x 10-6ML/s we find a critical nucleus size about 600 nm2. The corresponding value obtained from classic nucleation theory corresponds nicely with this direct result. We estimate the Gibbs free energy for nucleation under these conditions at 4 eV. The size fluctuations are an order of magnitude stronger than expected. At 410 K the influence of steps on the growth process becomes evident: domain growth is terminated by steps even when they are permeable for individual molecules. This leads to a novel Mullins-Sekerka type of growth instability: the growth is very fast along the steps and less fast perpendicular to the steps. The large solid angle at the advancing edge of the condensate dictates the high growth rate along the step.

A Data-Driven, Integrated Flare Model Based on Self-Organized Criticality

NASA Astrophysics Data System (ADS)

Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M.

2013-09-01

We interpret solar flares as events originating in solar active regions having reached the self-organized critical state, by alternatively using two versions of an "integrated flare model" - one static and one dynamic. In both versions the initial conditions are derived from observations aiming to investigate whether well-known scaling laws observed in the distribution functions of characteristic flare parameters are reproduced after the self-organized critical state has been reached. In the static model, we first apply a nonlinear force-free extrapolation that reconstructs the three-dimensional magnetic fields from two-dimensional vector magnetograms. We then locate magnetic discontinuities exceeding a threshold in the Laplacian of the magnetic field. These discontinuities are relaxed in local diffusion events, implemented in the form of cellular-automaton evolution rules. Subsequent loading and relaxation steps lead the system to self-organized criticality, after which the statistical properties of the simulated events are examined. In the dynamic version we deploy an enhanced driving mechanism, which utilizes the observed evolution of active regions, making use of sequential vector magnetograms. We first apply the static cellular automaton model to consecutive solar vector magnetograms until the self-organized critical state is reached. We then evolve the magnetic field inbetween these processed snapshots through spline interpolation, acting as a natural driver in the dynamic model. The identification of magnetically unstable sites as well as their relaxation follow the same rules as in the static model after each interpolation step. Subsequent interpolation/driving and relaxation steps cover all transitions until the end of the sequence. Physical requirements, such as the divergence-free condition for the magnetic field vector, are approximately satisfied in both versions of the model. We obtain robust power laws in the distribution functions of the modelled flaring events with scaling indices in good agreement with observations. We therefore conclude that well-known statistical properties of flares are reproduced after active regions reach self-organized criticality. The significant enhancement in both the static and the dynamic integrated flare models is that they initiate the simulation from observations, thus facilitating energy calculation in physical units. Especially in the dynamic version of the model, the driving of the system is based on observed, evolving vector magnetograms, allowing for the separation between MHD and kinetic timescales through the assignment of distinct MHD timestamps to each interpolation step.

Genetic inactivation of Nrf2 prevents clonal expansion of initiated cells in a nutritional model of rat hepatocarcinogenesis.

PubMed

Orrù, Claudia; Szydlowska, Marta; Taguchi, Keiko; Zavattari, Patrizia; Perra, Andrea; Yamamoto, Masayuki; Columbano, Amedeo

2018-06-21

Dysregulation of the Keap1-Nrf2 pathway has been observed in experimental and human tumors, suggesting possible roles of the pathway in cancer development. Herein, we examined whether Nrf2 (Nfe2l2) activation occurs at early steps of rat hepatocarcinogenesis, to assess critical contributions of Nrf2 to the onset of hepatocellular carcinoma (HCC). We used wild-type (WT) and Nrf2 knockout (Nrf2KO) rats treated with a single injection of diethylnitrosamine (DENA) followed by choline-devoid methionine-deficient (CMD) diet. This experimental model causes massive fatty liver and steatohepatitis with fibrosis and enables identification of early stages of hepatocarcinogenesis. We found that Nrf2 activation takes place in early preneoplastic lesions identified by the marker glutathione S-transferase placental form (GSTP). Nrf2 missense mutations, known to disrupt the Keap1-Nrf2 binding, were present in 65.7% of GSTP-positive foci. Nrf2KO rats were used to directly investigate whether Nrf2 is critical for initiation and/or clonal expansion of DENA-damaged hepatocytes. While Nrf2 genetic inactivation did not alter DENA-induced initiation, it led to increased liver injury and chronic compensatory hepatocyte regeneration when rats were fed a CMD diet. However, in spite of such a permissive environment, the livers of Nrf2KO rats did not display any preneoplastic lesion unlike those of WT rats. These results demonstrate that, in a model of hepatocarcinogenesis resembling human non-alcoholic fatty liver disease: i) Nrf2 is activated at early steps of the tumorigenic process and ii) Nrf2 is mandatory for the clonal expansion of initiated cells, indicating that Nrf2 is critical in the onset of HCC. Dysregulation of the Keap1-Nrf2 molecular pathway has been observed in human tumors. In a nutritional model of hepatocarcinogenesis, the protein Nrf2 is frequently mutated/activated at early steps of the tumorigenic process. Herein, we show that Nrf2 is mandatory for the development of preneoplastic lesions. These results suggest that Nrf2 has a critical role in the onset of hepatocellular carcinoma. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Laboratory Layered Latte

NASA Astrophysics Data System (ADS)

Xue, Nan; Khodaparast, Sepideh; Zhu, Lailai; Nunes, Janine; Kim, Hyoungsoo; Stone, Howard

2017-11-01

Layered composite fluids are sometimes observed in confined systems of rather chaotic initial states, for example, layered lattes formed by pouring espresso into a glass of warm milk. In such configurations, pouring forces a lower density liquid (espresso) into a higher density ambient, which is similar to the fountain effects that characterize a wide range of flows driven by injecting a fluid into a second miscible phase. Although the initial state of the mixture is complex and chaotic, there are conditions where the mixture cools at room temperature and exhibits an organized layered pattern. Here we report controlled experiments injecting a fluid into a miscible phase and show that, above a critical injection velocity, layering naturally emerges over the time scale of minutes. We perform experimental and numerical analyses of the time-dependent flows to observe and understand the convective circulation in the layers. We identify critical conditions to produce the layering and relate the results quantitatively to the critical Rayleigh number in double-diffusive convection, which indicates the competition between the horizontal thermal gradient and the vertical density gradient generated by the fluid injection. Based on this understanding, we show how to employ this single-step process to produce layered structures in soft materials, where the local elastic properties as well as the local material concentration vary step-wise along the length of the material.

A Critical Assessment of Vector Control for Dengue Prevention

PubMed Central

Achee, Nicole L.; Gould, Fred; Perkins, T. Alex; Reiner, Robert C.; Morrison, Amy C.; Ritchie, Scott A.; Gubler, Duane J.; Teyssou, Remy; Scott, Thomas W.

2015-01-01

Recently, the Vaccines to Vaccinate (v2V) initiative was reconfigured into the Partnership for Dengue Control (PDC), a multi-sponsored and independent initiative. This redirection is consistent with the growing consensus among the dengue-prevention community that no single intervention will be sufficient to control dengue disease. The PDC's expectation is that when an effective dengue virus (DENV) vaccine is commercially available, the public health community will continue to rely on vector control because the two strategies complement and enhance one another. Although the concept of integrated intervention for dengue prevention is gaining increasingly broader acceptance, to date, no consensus has been reached regarding the details of how and what combination of approaches can be most effectively implemented to manage disease. To fill that gap, the PDC proposed a three step process: (1) a critical assessment of current vector control tools and those under development, (2) outlining a research agenda for determining, in a definitive way, what existing tools work best, and (3) determining how to combine the best vector control options, which have systematically been defined in this process, with DENV vaccines. To address the first step, the PDC convened a meeting of international experts during November 2013 in Washington, DC, to critically assess existing vector control interventions and tools under development. This report summarizes those deliberations. PMID:25951103

Enhancing the Value of the Federal Climate-Relevant Data Through the Climate Data Initiative

NASA Astrophysics Data System (ADS)

Meyer, D. J.; Pinheiro Privette, A. C.; Bugbee, K.

2016-12-01

The Climate Data Initiative (CDI), launched by the Obama Administration in March of 2014, is an effort to leverage the extensive open Federal data to spur innovation and private-sector entrepreneurship around climate resilience. As part of this initiative the federal agencies identified key climate-relevant datasets and made them discoverable through an online catalog at data.gov/climate. Although this was a critical and foundational step to improve the discoverability to these federal data, enhancements to its accessibility and usability require a deeper understanding of the data needs of the different user communities. More recently, the focus of the CDI project has evolved toward extended engagement with communities of resilience trough the identification of use-cases. This effort aims to guide the next steps of the CDI project to make the CDI resources more easily integrated into decision support systems

Why Inquiry Is Inherently Difficult...and Some Ways to Make It Easier

ERIC Educational Resources Information Center

Meyer, Daniel Z.; Avery, Leanne M.

2010-01-01

In this article, the authors offer a framework that identifies two critical problems in designing inquiry-based instruction and suggests three models for developing instruction that overcomes those problems. The Protocol Model overcomes the Getting on Board Problem by providing students an initial experience through clearly delineated steps with a…

The Relationships Among Ecosystem Services and Human Well Being and the Construction of an Index of Well Being

EPA Science Inventory

The Millennium Ecosystem Assessment produced a compelling synthesis of the global value of ecosystem services to human well-being. While the MEA was a critical, initial step to demonstrate the potential for assessing global trends in ecosystem services, it is important to note th...

Selecting Top-of-the-Class Teachers for an Alternative Principal Preparation Program

ERIC Educational Resources Information Center

Mallory, Barbara J.; Zwadyk, Barbara; Johnson, Tina; Davis, James V.

2017-01-01

In an attempt to improve training and development of principals, the General Assembly in North Carolina established a competitive grant program to transform the way principals are certified. This qualitative study aimed to inform principal preparation practices by examining the initial, critical steps of recruitment, screening, and selection of…

E-learning for Critical Thinking: Using Nominal Focus Group Method to Inform Software Content and Design.

PubMed

Parker, Steve; Mayner, Lidia; Michael Gillham, David

2015-12-01

Undergraduate nursing students are often confused by multiple understandings of critical thinking. In response to this situation, the Critiique for critical thinking (CCT) project was implemented to provide consistent structured guidance about critical thinking. This paper introduces Critiique software, describes initial validation of the content of this critical thinking tool and explores wider applications of the Critiique software. Critiique is flexible, authorable software that guides students step-by-step through critical appraisal of research papers. The spelling of Critiique was deliberate, so as to acquire a unique web domain name and associated logo. The CCT project involved implementation of a modified nominal focus group process with academic staff working together to establish common understandings of critical thinking. Previous work established a consensus about critical thinking in nursing and provided a starting point for the focus groups. The study was conducted at an Australian university campus with the focus group guided by open ended questions. Focus group data established categories of content that academic staff identified as important for teaching critical thinking. This emerging focus group data was then used to inform modification of Critiique software so that students had access to consistent and structured guidance in relation to critical thinking and critical appraisal. The project succeeded in using focus group data from academics to inform software development while at the same time retaining the benefits of broader philosophical dimensions of critical thinking.

E-learning for Critical Thinking: Using Nominal Focus Group Method to Inform Software Content and Design

PubMed Central

Parker, Steve; Mayner, Lidia; Michael Gillham, David

2015-01-01

Background: Undergraduate nursing students are often confused by multiple understandings of critical thinking. In response to this situation, the Critiique for critical thinking (CCT) project was implemented to provide consistent structured guidance about critical thinking. Objectives: This paper introduces Critiique software, describes initial validation of the content of this critical thinking tool and explores wider applications of the Critiique software. Materials and Methods: Critiique is flexible, authorable software that guides students step-by-step through critical appraisal of research papers. The spelling of Critiique was deliberate, so as to acquire a unique web domain name and associated logo. The CCT project involved implementation of a modified nominal focus group process with academic staff working together to establish common understandings of critical thinking. Previous work established a consensus about critical thinking in nursing and provided a starting point for the focus groups. The study was conducted at an Australian university campus with the focus group guided by open ended questions. Results: Focus group data established categories of content that academic staff identified as important for teaching critical thinking. This emerging focus group data was then used to inform modification of Critiique software so that students had access to consistent and structured guidance in relation to critical thinking and critical appraisal. Conclusions: The project succeeded in using focus group data from academics to inform software development while at the same time retaining the benefits of broader philosophical dimensions of critical thinking. PMID:26835469

11-Step Total Synthesis of (−)-Maoecrystal V

PubMed Central

2016-01-01

An expedient, practical, and enantioselective route to the highly congested ent-kaurane diterpene maoecrystal V is presented. This route, which has been several years in the making, is loosely modeled after a key pinacol shift in the proposed biosynthesis. Only 11 steps, many of which are strategic in that they build key skeletal bonds and incorporate critical functionalities, are required to access (−)-maoecrystal V. Several unique and unexpected maneuvers are featured in this potentially scalable pathway. Reevaluation of the biological activity calls into question the initial exuberance surrounding this natural product. PMID:27457680

Future Directions and Challenges in Shell Stability Analysis

NASA Technical Reports Server (NTRS)

Arbocz, Johann

1997-01-01

An answer is sought to the question how comes that today, in 1997, after so many years of concentrated research effort, when it comes to designing buckling critical thin walled shells, one cannot do any better than using the rather conservative Lower Bound Design Philosophy of the sixties. It will be shown that with the establishment of Initial Imperfection Data Banks and the introduction of Probabilistic Design Procedures one has, what appears to be, a viable alternative that when used judiciously may lead step by step to improved shell design recommendations.

Nanodusty plasma chemistry: a mechanistic and variational transition state theory study of the initial steps of silyl anion-silane and silylene anion-silane polymerization reactions.

PubMed

Bao, Junwei Lucas; Seal, Prasenjit; Truhlar, Donald G

2015-06-28

The growth of nanodusty particles, which is critical in plasma chemistry, physics, and engineering. The aim of the present work is to understand the detailed reaction mechanisms of early steps in this growth. The polymerization of neutral silane with the silylene or silyl anion, which eliminates molecular hydrogen with the formation of their higher homologues, governs the silicon hydride clustering in nanodusty plasma chemistry. The detailed mechanisms of these important polymerization reactions in terms of elementary reactions have not been proposed yet. In the present work, we investigated the initial steps of these polymerization reactions, i.e., the SiH4 + Si2H4(-)/Si2H5(-) reactions, and we propose a three-step mechanism, which is also applicable to the following polymerization steps. CM5 charges of all the silicon-containing species were computed in order to analyze the character of the species in the proposed reaction mechanisms. We also calculated thermal rate constant of each step using multi-structural canonical variational transition state theory (MS-CVT) with the small-curvature tunneling (SCT) approximation, based on the minimum energy path computed using M08-HX/MG3S electronic structure method.

Targeting the eIF4F translation initiation complex: a critical nexus for cancer development.

PubMed

Pelletier, Jerry; Graff, Jeremy; Ruggero, Davide; Sonenberg, Nahum

2015-01-15

Elevated protein synthesis is an important feature of many cancer cells and often arises as a consequence of increased signaling flux channeled to eukaryotic initiation factor 4F (eIF4F), the key regulator of the mRNA-ribosome recruitment phase of translation initiation. In many cellular and preclinical models of cancer, eIF4F deregulation results in changes in translational efficiency of specific mRNA classes. Importantly, many of these mRNAs code for proteins that potently regulate critical cellular processes, such as cell growth and proliferation, enhanced cell survival and cell migration that ultimately impinge on several hallmarks of cancer, including increased angiogenesis, deregulated growth control, enhanced cellular survival, epithelial-to-mesenchymal transition, invasion, and metastasis. By being positioned as the molecular nexus downstream of key oncogenic signaling pathways (e.g., Ras, PI3K/AKT/TOR, and MYC), eIF4F serves as a direct link between important steps in cancer development and translation initiation. Identification of mRNAs particularly responsive to elevated eIF4F activity that typifies tumorigenesis underscores the critical role of eIF4F in cancer and raises the exciting possibility of developing new-in-class small molecules targeting translation initiation as antineoplastic agents. ©2014 American Association for Cancer Research.

A Data-Driven Approach to SEM Development at a Two-Year College

ERIC Educational Resources Information Center

Pirius, Landon K.

2014-01-01

This article explores implementation of strategic enrollment management (SEM) at a two-year college and why SEM is critical to the long-term viability of an institution. This article also outlines the five initial steps needed to implement SEM, including identifying SEM leadership, building a SEM committee, developing a common understanding of…

P-2 Years Targeted to Achieve Grade 3 Reading Proficiency

ERIC Educational Resources Information Center

Gewertz, Catherine

2011-01-01

In a bid to help more students read proficiently in 3rd grade--a skill considered critical to their future educational success--new laws and initiatives springing up around the country require educators to step up their efforts to identify and help struggling readers even before they enter kindergarten. It's not unusual for states or school…

Deliberation Makes a Difference: Preparation Strategies for TeamSTEPPS Implementation in Small and Rural Hospitals

PubMed Central

Zhu, Xi; Baloh, Jure; Ward, Marcia M.; Stewart, Greg L.

2016-01-01

Small and rural hospitals face special challenges to implement and sustain organization-wide quality improvement (QI) initiatives due to limited resources and infrastructures. We studied the implementation of TeamSTEPPS, a national QI initiative, in 14 critical access hospitals. Drawing on QI and organization development theories, we propose five strategic preparation steps for TeamSTEPPS: assess needs, reflect on the context, set goals, develop a shared understanding, and select change agents. We explore how hospitals’ practices correspond to suggested best practices by analyzing qualitative data collected through quarterly interviews with key informants. We find that the level of deliberation was a key factor that differentiated hospitals’ practices. Hospitals that were more deliberate in preparing for the five strategic steps were more likely to experience engagement, perceive efficacy, foresee and manage barriers, and achieve progress during implementation. We discuss potential steps that hospitals may take to better prepare for TeamSTEPPS implementation. PMID:26429835

Fully Flexible Docking of Medium Sized Ligand Libraries with RosettaLigand

PubMed Central

DeLuca, Samuel; Khar, Karen; Meiler, Jens

2015-01-01

RosettaLigand has been successfully used to predict binding poses in protein-small molecule complexes. However, the RosettaLigand docking protocol is comparatively slow in identifying an initial starting pose for the small molecule (ligand) making it unfeasible for use in virtual High Throughput Screening (vHTS). To overcome this limitation, we developed a new sampling approach for placing the ligand in the protein binding site during the initial ‘low-resolution’ docking step. It combines the translational and rotational adjustments to the ligand pose in a single transformation step. The new algorithm is both more accurate and more time-efficient. The docking success rate is improved by 10–15% in a benchmark set of 43 protein/ligand complexes, reducing the number of models that typically need to be generated from 1000 to 150. The average time to generate a model is reduced from 50 seconds to 10 seconds. As a result we observe an effective 30-fold speed increase, making RosettaLigand appropriate for docking medium sized ligand libraries. We demonstrate that this improved initial placement of the ligand is critical for successful prediction of an accurate binding position in the ‘high-resolution’ full atom refinement step. PMID:26207742

Primary School Pre-Service Teachers' Self-Assessed Competency Level of Teaching How to Read in Turkey

ERIC Educational Resources Information Center

Çayir, Aybala

2017-01-01

Learning to read is an important step for a child's academic and social success. Meaningful and fluent reading skills are linked to children's progress in their thinking and criticizing abilities. The knowledge and skills required for effective reading are initially taught in primary schools. The main responsibility of primary school teachers' is…

Young drivers' engagement with social interactive technology on their smartphone: Critical beliefs to target in public education messages.

PubMed

Gauld, Cassandra S; Lewis, Ioni M; White, Katherine M; Watson, Barry

2016-11-01

The current study forms part of a larger study based on the Step Approach to Message Design and Testing (SatMDT), a new and innovative framework designed to guide the development and evaluation of health communication messages, including road safety messages. This four step framework is based on several theories, including the Theory of Planned Behaviour. The current study followed steps one and two of the SatMDT framework and utilised a quantitative survey to validate salient beliefs (behavioural, normative, and control) about initiating, monitoring/reading, and responding to social interactive technology on smartphones by N=114 (88F, 26M) young drivers aged 17-25 years. These beliefs had been elicited in a prior in-depth qualitative study. A subsequent critical beliefs analysis identified seven beliefs as potential targets for public education messages, including, 'slow-moving traffic' (control belief - facilitator) for both monitoring/reading and responding behaviours; 'feeling at ease that you had received an expected communication' (behavioural belief -advantage) for monitoring/reading behaviour; and 'friends/peers more likely to approve' (normative belief) for responding behaviour. Potential message content targeting these seven critical beliefs is discussed in accordance with the SatMDT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Utility of repeat testing of critical values: a Q-probes analysis of 86 clinical laboratories.

PubMed

Lehman, Christopher M; Howanitz, Peter J; Souers, Rhona; Karcher, Donald S

2014-06-01

A common laboratory practice is to repeat critical values before reporting the test results to the clinical care provider. This may be an unnecessary step that delays the reporting of critical test results without adding value to the accuracy of the test result. To determine the proportions of repeated chemistry and hematology critical values that differ significantly from the original value as defined by the participating laboratory, to determine the threshold differences defined by the laboratory as clinically significant, and to determine the additional time required to analyze the repeat test. Participants prospectively reviewed critical test results for 4 laboratory tests: glucose, potassium, white blood cell count, and platelet count. Participants reported the following information: initial and repeated test result; time initial and repeat results were first known to laboratory staff; critical result notification time; if the repeat result was still a critical result; if the repeat result was significantly different from the initial result, as judged by the laboratory professional or policy; significant difference threshold, as defined by the laboratory; the make and model of the instrument used for primary and repeat testing. Routine, repeat analysis of critical values is a common practice. Most laboratories did not formally define a significant difference between repeat results. Repeated results were rarely considered significantly different. Median repeated times were at least 17 to 21 minutes for 10% of laboratories. Twenty percent of laboratories reported at least 1 incident in the last calendar year of delayed result reporting that clinicians indicated had adversely affected patient care. Routine repeat analysis of automated chemistry and hematology critical values is unlikely to be clinically useful and may adversely affect patient care.

A resolution supporting the goals and ideals of World Malaria Day, and reaffirming United States leadership and support for efforts to combat malaria as a critical component of the President's Global Health Initiative.

THOMAS, 111th Congress

Sen. Feingold, Russell D. [D-WI

2010-04-22

Senate - 04/22/2010 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

Critical role of cerebellar fastigial nucleus in programming sequences of saccades

PubMed Central

King, Susan A.; Schneider, Rosalyn M.; Serra, Alessandro; Leigh, R. John

2011-01-01

The cerebellum plays an important role in programming accurate saccades. Cerebellar lesions affecting the ocular motor region of the fastigial nucleus (FOR) cause saccadic hypermetria; however, if a second target is presented before a saccade can be initiated (double-step paradigm), saccade hypermetria may be decreased. We tested the hypothesis that the cerebellum, especially FOR, plays a pivotal role in programming sequences of saccades. We studied patients with saccadic hypermetria due either to genetic cerebellar ataxia or surgical lesions affecting FOR and confirmed that the gain of initial saccades made to double-step stimuli was reduced compared with the gain of saccades to single target jumps. Based on measurements of the intersaccadic interval, we found that the ability to perform parallel processing of saccades was reduced or absent in all of our patients with cerebellar disease. Our results support the crucial role of the cerebellum, especially FOR, in programming sequences of saccades. PMID:21950988

Mechanisms for regulating step length while running towards and over an obstacle.

PubMed

Larsen, Roxanne J; Jackson, William H; Schmitt, Daniel

2016-10-01

The ability to run across uneven terrain with continuous stable movement is critical to the safety and efficiency of a runner. Successful step-to-step stabilization while running may be mediated by minor adjustments to a few key parameters (e.g., leg stiffness, step length, foot strike pattern). However, it is not known to what degree runners in relatively natural settings (e.g., trails, paved road, curbs) use the same strategies across multiple steps. This study investigates how three readily measurable running parameters - step length, foot placement, and foot strike pattern - are adjusted in response to encountering a typical urban obstacle - a sidewalk curb. Thirteen subjects were video-recorded as they ran at self-selected slow and fast paces. Runners targeted a specific distance before the curb for foot placement, and lengthened their step over the curb (p<0.0001) regardless of where the step over the curb was initiated. These strategies of adaptive locomotion disrupt step cycles temporarily, and may increase locomotor cost and muscle loading, but in the end assure dynamic stability and minimize the risk of injury over the duration of a run. Copyright © 2016 Elsevier B.V. All rights reserved.

How Academic Psychiatry Can Better Prepare Students for Their Future Patients: Part II--A Course in Ultra-Brief Initial Diagnostic Screening Suitable for Future Primary Care Physicians

ERIC Educational Resources Information Center

Lake, C. Raymond

2008-01-01

Depression is inadequately treated in primary care (PC), primarily because of a failure to recognize symptoms of depression. The results can be catastrophic and include death by suicide. The prevention of suicide is a critical function of physicians. The recognition of depression is the first step to preventing suicide because suicide…

Frontal Joint Dynamics when Initiating Stair Ascent from a Walk versus a Stand

PubMed Central

Vallabhajosula, Srikant; Yentes, Jennifer M.; Stergiou, Nicholas

2011-01-01

Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using a 3-D motion capture system and kinetics data using two force platforms on the first and third stair treads were recorded simultaneously as ten healthy young adults ascended a custom-built staircase. Data were collected from two starting conditions of stair ascent, from a walk (speed: 1.42±0.21m/s) and from a stand. Results showed that subjects generated greater peak knee abductor moment and greater peak hip abductor moment when initiating stair ascent from a walk. Greater peak joint moments and powers at all joints were also seen while ascending the second ipsilateral step. Particularly, greater peak hip abductor moment was needed to avoid contact of the contralateral limb with the intermediate step by counteracting the pelvic drop on the contralateral side. This could be important for therapists using stair climbing as a testing/training tool to evaluate hip strength in individuals with documented frontal plane abnormalities (i.e. knee and hip osteoarthritis, ACL injury). PMID:22172606

Towards development and validation of an intraoperative assessment tool for robot-assisted radical prostatectomy training: results of a Delphi study.

PubMed

Morris, Christopher; Hoogenes, Jen; Shayegan, Bobby; Matsumoto, Edward D

2017-01-01

As urology training shifts toward competency-based frameworks, the need for tools for high stakes assessment of trainees is crucial. Validated assessment metrics are lacking for many robot-assisted radical prostatectomy (RARP). As it is quickly becoming the gold standard for treatment of localized prostate cancer, the development and validation of a RARP assessment tool for training is timely. We recruited 13 expert RARP surgeons from the United States and Canada to serve as our Delphi panel. Using an initial inventory developed via a modified Delphi process with urology residents, fellows, and staff at our institution, panelists iteratively rated each step and sub-step on a 5-point Likert scale of agreement for inclusion in the final assessment tool. Qualitative feedback was elicited for each item to determine proper step placement, wording, and suggestions. Panelist's responses were compiled and the inventory was edited through three iterations, after which 100% consensus was achieved. The initial inventory steps were decreased by 13% and a skip pattern was incorporated. The final RARP stepwise inventory was comprised of 13 critical steps with 52 sub-steps. There was no attrition throughout the Delphi process. Our Delphi study resulted in a comprehensive inventory of intraoperative RARP steps with excellent consensus. This final inventory will be used to develop a valid and psychometrically sound intraoperative assessment tool for use during RARP training and evaluation, with the aim of increasing competency of all trainees. Copyright® by the International Brazilian Journal of Urology.

Towards development and validation of an intraoperative assessment tool for robot-assisted radical prostatectomy training: results of a Delphi study

PubMed Central

Morris, Christopher; Hoogenes, Jen; Shayegan, Bobby; Matsumoto, Edward D.

2017-01-01

ABSTRACT Introduction As urology training shifts toward competency-based frameworks, the need for tools for high stakes assessment of trainees is crucial. Validated assessment metrics are lacking for many robot-assisted radical prostatectomy (RARP). As it is quickly becoming the gold standard for treatment of localized prostate cancer, the development and validation of a RARP assessment tool for training is timely. Materials and methods We recruited 13 expert RARP surgeons from the United States and Canada to serve as our Delphi panel. Using an initial inventory developed via a modified Delphi process with urology residents, fellows, and staff at our institution, panelists iteratively rated each step and sub-step on a 5-point Likert scale of agreement for inclusion in the final assessment tool. Qualitative feedback was elicited for each item to determine proper step placement, wording, and suggestions. Results Panelist’s responses were compiled and the inventory was edited through three iterations, after which 100% consensus was achieved. The initial inventory steps were decreased by 13% and a skip pattern was incorporated. The final RARP stepwise inventory was comprised of 13 critical steps with 52 sub-steps. There was no attrition throughout the Delphi process. Conclusions Our Delphi study resulted in a comprehensive inventory of intraoperative RARP steps with excellent consensus. This final inventory will be used to develop a valid and psychometrically sound intraoperative assessment tool for use during RARP training and evaluation, with the aim of increasing competency of all trainees. PMID:28379668

Accelerometer-based step initiation control for gait-assist neuroprostheses.

PubMed

Foglyano, Kevin M; Schnellenberger, John R; Kobetic, Rudi; Lombardo, Lisa; Pinault, Gilles; Selkirk, Stephen; Makowski, Nathaniel S; Triolo, Ronald J

2016-01-01

Electrical activation of paralyzed musculature can generate or augment joint movements required for walking after central nervous system trauma. Proper timing of stimulation relative to residual volitional control is critical to usefully affecting ambulation. This study evaluates three-dimensional accelerometers and customized algorithms to detect the intent to step from voluntary movements to trigger stimulation during walking in individuals with significantly different etiologies, mobility limitations, manual dexterities, and walking aids. Three individuals with poststroke hemiplegia or partial spinal cord injury exhibiting varying gait deficits were implanted with multichannel pulse generators to provide joint motions at the hip, knee, and ankle. An accelerometer integrated into the external control unit was used to detect heel strike or walker movement, and wireless accelerometers were used to detect crutch strike. Algorithms were developed for each sensor location to detect intent to step to progress through individualized stimulation patterns. Testing these algorithms produced detection accuracies of at least 90% on both level ground and uneven terrain. All participants use their accelerometer-triggered implanted gait systems in the community; the validation/system testing was completed in the hospital. The results demonstrated that safe, reliable, and convenient accelerometer-based step initiation can be achieved regardless of specific gait deficits, manual dexterities, and walking aids.

Numerical investigation on the prefabricated crack propagation of FV520B stainless steel

NASA Astrophysics Data System (ADS)

Pan, Juyi; Qin, Ming; Chen, Songying

FV520B is a common stainless steel for manufacturing centrifugal compressor impeller and shaft. The internal metal flaw destroys the continuity of the material matrix, resulting in the crack propagation fracture of the component, which seriously reduces the service life of the equipment. In this paper, Abaqus software was used to simulate the prefabricated crack propagation of FV520B specimen with unilateral gap. The results of static crack propagation simulation results show that the maximum value of stress-strain located at the tip of the crack and symmetrical distributed like a butterfly along the prefabricated crack direction, the maximum stress is 1990 MPa and the maximum strain is 9.489 × 10-3. The Mises stress and stress intensity factor KI increases with the increase of the expansion step, the critical value of crack initiation is reached at the 6th extension step. The dynamic crack propagation simulation shows that the crack propagation path is perpendicular to the load loading direction. Similarly, the maximum Mises stress located at the crack tip and is symmetrically distributed along the crack propagation direction. The critical stress range of the crack propagation is 23.3-43.4 MPa. The maximum value of stress-strain curve located at the 8th extension step, that is, the crack initiation point, the maximum stress is 55.22 MPa, and the maximum strain is 2.26 × 10-4. On the crack tip, the stress changed as 32.24-40.16 MPa, the strain is at 1.292 × 10-4-1.897 × 10-4.

A Coordinated Initialization Process for the Distributed Space Exploration Simulation

NASA Technical Reports Server (NTRS)

Crues, Edwin Z.; Phillips, Robert G.; Dexter, Dan; Hasan, David

2007-01-01

A viewgraph presentation on the federate initialization process for the Distributed Space Exploration Simulation (DSES) is described. The topics include: 1) Background: DSES; 2) Simulation requirements; 3) Nine Step Initialization; 4) Step 1: Create the Federation; 5) Step 2: Publish and Subscribe; 6) Step 3: Create Object Instances; 7) Step 4: Confirm All Federates Have Joined; 8) Step 5: Achieve initialize Synchronization Point; 9) Step 6: Update Object Instances With Initial Data; 10) Step 7: Wait for Object Reflections; 11) Step 8: Set Up Time Management; 12) Step 9: Achieve startup Synchronization Point; and 13) Conclusions

Models for structuring a clinical initiative to enhance palliative care in the intensive care unit: a report from the IPAL-ICU Project (Improving Palliative Care in the ICU).

PubMed

Nelson, Judith E; Bassett, Rick; Boss, Renee D; Brasel, Karen J; Campbell, Margaret L; Cortez, Therese B; Curtis, J Randall; Lustbader, Dana R; Mulkerin, Colleen; Puntillo, Kathleen A; Ray, Daniel E; Weissman, David E

2010-09-01

To describe models used in successful clinical initiatives to improve the quality of palliative care in critical care settings. We searched the MEDLINE database from inception to April 2010 for all English language articles using the terms "intensive care," "critical care," or "ICU" and "palliative care"; we also hand-searched reference lists and author files. Based on review and synthesis of these data and the experiences of our interdisciplinary expert Advisory Board, we prepared this consensus report. We critically reviewed the existing data with a focus on models that have been used to structure clinical initiatives to enhance palliative care for critically ill patients in intensive care units and their families. There are two main models for intensive care unit-palliative care integration: 1) the "consultative model," which focuses on increasing the involvement and effectiveness of palliative care consultants in the care of intensive care unit patients and their families, particularly those patients identified as at highest risk for poor outcomes; and 2) the "integrative model," which seeks to embed palliative care principles and interventions into daily practice by the intensive care unit team for all patients and families facing critical illness. These models are not mutually exclusive but rather represent the ends of a spectrum of approaches. Choosing an overall approach from among these models should be one of the earliest steps in planning an intensive care unit-palliative care initiative. This process entails a careful and realistic assessment of available resources, attitudes of key stakeholders, structural aspects of intensive care unit care, and patterns of local practice in the intensive care unit and hospital. A well-structured intensive care unit-palliative care initiative can provide important benefits for patients, families, and providers.

How to perform a critical appraisal of diagnostic tests: 7 steps.

PubMed

Chughtai, Aamer; Kelly, Aine Marie; Cronin, Paul

2015-06-01

The critically appraised topic (CAT) is a format in evidence-based practice for sharing information. A CAT is a standardized way of summarizing the most current research evidence focused on a pertinent clinical question. Its aim is to provide both a critique of the most up-to-date retrieved research and an indication of the clinical relevance of results. A clinical question is initially generated following a patient encounter, which leads to and directs a literature search to answer the clinical question. Studies obtained from the literature search are assigned a level of evidence. This allows the most valid and relevant articles to be selected and to be critically appraised. The results are summarized, and this information is translated into clinically useful procedures and processes.

A discrete classical space-time could require 6 extra-dimensions

NASA Astrophysics Data System (ADS)

Guillemant, Philippe; Medale, Marc; Abid, Cherifa

2018-01-01

We consider a discrete space-time in which conservation laws are computed in such a way that the density of information is kept bounded. We use a 2D billiard as a toy model to compute the uncertainty propagation in ball positions after every shock and the corresponding loss of phase information. Our main result is the computation of a critical time step above which billiard calculations are no longer deterministic, meaning that a multiverse of distinct billiard histories begins to appear, caused by the lack of information. Then, we highlight unexpected properties of this critical time step and the subsequent exponential evolution of the number of histories with time, to observe that after certain duration all billiard states could become possible final states, independent of initial conditions. We conclude that if our space-time is really a discrete one, one would need to introduce extra-dimensions in order to provide supplementary constraints that specify which history should be played.

Dynamic data-driven integrated flare model based on self-organized criticality

NASA Astrophysics Data System (ADS)

Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M. K.

2013-05-01

Context. We interpret solar flares as events originating in active regions that have reached the self-organized critical state. We describe them with a dynamic integrated flare model whose initial conditions and driving mechanism are derived from observations. Aims: We investigate whether well-known scaling laws observed in the distribution functions of characteristic flare parameters are reproduced after the self-organized critical state has been reached. Methods: To investigate whether the distribution functions of total energy, peak energy, and event duration follow the expected scaling laws, we first applied the previously reported static cellular automaton model to a time series of seven solar vector magnetograms of the NOAA active region 8210 recorded by the Imaging Vector Magnetograph on May 1 1998 between 18:59 UT and 23:16 UT until the self-organized critical state was reached. We then evolved the magnetic field between these processed snapshots through spline interpolation, mimicking a natural driver in our dynamic model. We identified magnetic discontinuities that exceeded a threshold in the Laplacian of the magnetic field after each interpolation step. These discontinuities were relaxed in local diffusion events, implemented in the form of cellular automaton evolution rules. Subsequent interpolation and relaxation steps covered all transitions until the end of the processed magnetograms' sequence. We additionally advanced each magnetic configuration that has reached the self-organized critical state (SOC configuration) by the static model until 50 more flares were triggered, applied the dynamic model again to the new sequence, and repeated the same process sufficiently often to generate adequate statistics. Physical requirements, such as the divergence-free condition for the magnetic field, were approximately imposed. Results: We obtain robust power laws in the distribution functions of the modeled flaring events with scaling indices that agree well with observations. Peak and total flare energy obey single power laws with indices -1.65 ± 0.11 and -1.47 ± 0.13, while the flare duration is best fitted with a double power law (-2.15 ± 0.15 and -3.60 ± 0.09 for the flatter and steeper parts, respectively). Conclusions: We conclude that well-known statistical properties of flares are reproduced after active regions reach the state of self-organized criticality. A significant enhancement of our refined cellular automaton model is that it initiates and further drives the simulation from observed evolving vector magnetograms, thus facilitating energy calculation in physical units, while a separation between MHD and kinetic timescales is possible by assigning distinct MHD timestamps to each interpolation step.

Turning tumor-promoting copper into an anti-cancer weapon via high-throughput chemistry.

PubMed

Wang, F; Jiao, P; Qi, M; Frezza, M; Dou, Q P; Yan, B

2010-01-01

Copper is an essential element for multiple biological processes. Its concentration is elevated to a very high level in cancer tissues for promoting cancer development through processes such as angiogenesis. Organic chelators of copper can passively reduce cellular copper and serve the role as inhibitors of angiogenesis. However, they can also actively attack cellular targets such as proteasome, which plays a critical role in cancer development and survival. The discovery of such molecules initially relied on a step by step synthesis followed by biological assays. Today high-throughput chemistry and high-throughput screening have significantly expedited the copper-binding molecules discovery to turn "cancer-promoting" copper into anti-cancer agents.

[Results from ten years newborn hearing screening in a secondary hospital].

PubMed

Sequi Canet, José Miguel; Sala Langa, Maria José; Collar Del Castillo, José Ignacio

2016-10-01

A critical analysis is performed on the results of a newborn hearing screening program in a regional hospital. Screening results from 14,247 newborns in our maternity ward from 2002 to 2013. Two step recordings of bilateral otoacoustic emissions (initial and repeat, if failed, at about one month of life). Assessment by clinical brainstem responses. The first step was performed on 14,015 newborns (98.3% of the total) reaching the screening objective. The first step pass figures were 93.7%, which implies a good pass rate with a few patients to repeat. The second step is also good because it has a pass rate of 88.9% of newborns examined (only 0.63% of initial group needed brainstem responses assessment), but 10.6% were lost to follow up, and that is a major problem. In newborns, scheduled for brainstem responses, the loss to follow-up is worse, with a figure of 29.5%, despite the high accuracy of this test given that 69.4% of those assessed showed hearing loss. This figure represents a 0.31% of the initial group, and is a similar to that published for congenital hearing loss. Including patients that were lost to follow up this figure could be greater. Newborn hearing screening is useful but needs stronger control to avoid the follow up loss. In order to achieve this, it is crucial to have a good database and a screening coordinator. Copyright © 2015 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Human immune cells' behavior and survival under bioenergetically restricted conditions in an in vitro fracture hematoma model

PubMed Central

Hoff, Paula; Maschmeyer, Patrick; Gaber, Timo; Schütze, Tabea; Raue, Tobias; Schmidt-Bleek, Katharina; Dziurla, René; Schellmann, Saskia; Lohanatha, Ferenz Leonard; Röhner, Eric; Ode, Andrea; Burmester, Gerd-Rüdiger; Duda, Georg N; Perka, Carsten; Buttgereit, Frank

2013-01-01

The initial inflammatory phase of bone fracture healing represents a critical step for the outcome of the healing process. However, both the mechanisms initiating this inflammatory phase and the function of immune cells present at the fracture site are poorly understood. In order to study the early events within a fracture hematoma, we established an in vitro fracture hematoma model: we cultured hematomas forming during an osteotomy (artificial bone fracture) of the femur during total hip arthroplasty (THA) in vitro under bioenergetically controlled conditions. This model allowed us to monitor immune cell populations, cell survival and cytokine expression during the early phase following a fracture. Moreover, this model enabled us to change the bioenergetical conditions in order to mimic the in vivo situation, which is assumed to be characterized by hypoxia and restricted amounts of nutrients. Using this model, we found that immune cells adapt to hypoxia via the expression of angiogenic factors, chemoattractants and pro-inflammatory molecules. In addition, combined restriction of oxygen and nutrient supply enhanced the selective survival of lymphocytes in comparison with that of myeloid derived cells (i.e., neutrophils). Of note, non-restricted bioenergetical conditions did not show any similar effects regarding cytokine expression and/or different survival rates of immune cell subsets. In conclusion, we found that the bioenergetical conditions are among the crucial factors inducing the initial inflammatory phase of fracture healing and are thus a critical step for influencing survival and function of immune cells in the early fracture hematoma. PMID:23396474

Kinetic characterization of the critical step in HIV-1 protease maturation.

PubMed

Sadiq, S Kashif; Noé, Frank; De Fabritiis, Gianni

2012-12-11

HIV maturation requires multiple cleavage of long polyprotein chains into functional proteins that include the viral protease itself. Initial cleavage by the protease dimer occurs from within these precursors, and yet only a single protease monomer is embedded in each polyprotein chain. Self-activation has been proposed to start from a partially dimerized protease formed from monomers of different chains binding its own N termini by self-association to the active site, but a complete structural understanding of this critical step in HIV maturation is missing. Here, we captured the critical self-association of immature HIV-1 protease to its extended amino-terminal recognition motif using large-scale molecular dynamics simulations, thus confirming the postulated intramolecular mechanism in atomic detail. We show that self-association to a catalytically viable state requires structural cooperativity of the flexible β-hairpin "flap" regions of the enzyme and that the major transition pathway is first via self-association in the semiopen/open enzyme states, followed by enzyme conformational transition into a catalytically viable closed state. Furthermore, partial N-terminal threading can play a role in self-association, whereas wide opening of the flaps in concert with self-association is not observed. We estimate the association rate constant (k(on)) to be on the order of ∼1 × 10(4) s(-1), suggesting that N-terminal self-association is not the rate-limiting step in the process. The shown mechanism also provides an interesting example of molecular conformational transitions along the association pathway.

Frontal joint dynamics when initiating stair ascent from a walk versus a stand.

PubMed

Vallabhajosula, Srikant; Yentes, Jennifer M; Stergiou, Nicholas

2012-02-02

Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using a 3-D motion capture system and kinetics data using two force platforms on the first and third stair treads were recorded simultaneously as ten healthy young adults ascended a custom-built staircase. Data were collected from two starting conditions of stair ascent, from a walk (speed: 1.42 ± 0.21 m/s) and from a stand. Results showed that subjects generated greater peak knee abductor moment and greater peak hip abductor moment when initiating stair ascent from a walk. Greater peak joint moments and powers at all joints were also seen while ascending the second ipsilateral step. Particularly, greater peak hip abductor moment was needed to avoid contact of the contralateral limb with the intermediate step by counteracting the pelvic drop on the contralateral side. This could be important for therapists using stair climbing as a testing/training tool to evaluate hip strength in individuals with documented frontal plane abnormalities (i.e. knee and hip osteoarthritis, ACL injury). Copyright © 2011 Elsevier Ltd. All rights reserved.

Critical role of cerebellar fastigial nucleus in programming sequences of saccades.

PubMed

King, Susan A; Schneider, Rosalyn M; Serra, Alessandro; Leigh, R John

2011-09-01

The cerebellum plays an important role in programming accurate saccades. Cerebellar lesions affecting the ocular motor region of the fastigial nucleus (FOR) cause saccadic hypermetria; however, if a second target is presented before a saccade can be initiated (double-step paradigm), saccade hypermetria may be decreased. We tested the hypothesis that the cerebellum, especially FOR, plays a pivotal role in programming sequences of saccades. We studied patients with saccadic hypermetria because of either genetic cerebellar ataxia or surgical lesions affecting FOR and confirmed that the gain of initial saccades made to double-step stimuli was reduced compared with the gain of saccades to single target jumps. Based on measurements of the intersaccadic interval, we found that the ability to perform parallel processing of saccades was reduced or absent in all of our patients with cerebellar disease. Our results support the crucial role of the cerebellum, especially FOR, in programming sequences of saccades. © 2011 New York Academy of Sciences.

An improved implementable process for the synthesis of zeolite 4A from bauxite tailings and its Cr3+ removal capacity

NASA Astrophysics Data System (ADS)

Lei, Peng-cheng; Shen, Xian-jiang; Li, Yang; Guo, Min; Zhang, Mei

2016-07-01

A simple and practical method for the synthesis of zeolite 4A from bauxite tailings is presented in this paper. Systematic investigations were carried out regarding the capacity of zeolite 4A to remove Cr(III) from aqueous solutions with relatively low initial concentrations of Cr(III) (5-100 mg·L-1). It is found that the new method is extremely cost-effective and can significantly contribute in decreasing environmental pollution caused by the dumping of bauxite tailings. The Cr(III) removal capacity highly depends on the initial pH value and concentration of Cr(III) in the solution. The maximum removal capacity of Cr(III) was evaluated to be 85.1 mg·g-1 for zeolite 4A, measured at an initial pH value of 4 and an initial Cr(III) concentration of 5 mg·L-1. This approach enables a higher removal capacity at lower concentrations of Cr(III), which is a clear advantage over the chemical precipitation method. The removal mechanism of Cr(III) by zeolite 4A was examined. The results suggest that both ion exchange and the surface adsorption-crystallization reaction are critical steps. These two steps collectively resulted in the high removal capacity of zeolite 4A to remove Cr(III).

Perspective—Localized Corrosion: Passive Film Breakdown vs Pit Growth Stability

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

Frankel, G. S.; Li, Tianshu; Scully, J. R.

2017-02-24

A debate about the critical step in localized corrosion has raged for decades. Some researchers focus on the composition and structure of the passive film associated with the initial breakdown of the film, whereas others consider that the susceptibility to pitting is controlled by the pit growth kinetics and the stabilization of pit growth. The basis for a unified theory of pitting is presented here in which pit stability considerations are controlling under aggressive conditions (harsh electrolytes and extreme environments and/or susceptible microstructures) and the passive film properties and protectiveness are the critical factors in less extreme environments and/or formore » less susceptible alloys.« less

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

Chen, Daohong; Chen, Xi; Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003

Highlights: ► CCCP-induced LC3 lipidation can be independent of initiation/nucleation molecules. ► Atg9-mediated trafficking is critically required for CCCP-induced LC3 lipidation. ► CCCP-induced mitophagy may thus be more dependent on Atg9-positive vesicles. -- Abstract: Treatment of cells with carbonyl cyanide m-chlorophenylhydrazone (CCCP), a mitochondrial proton gradient uncoupler, can result in mitochondrial damage and autophagy activation, which in turn eliminates the injured mitochondria in a Parkin-dependent way. How CCCP mobilizes the autophagy machinery is not fully understood. By analyzing a key autophagy step, LC3 lipidation, we examined the roles of two kinase complexes typically involved in the initiation and nucleation phasesmore » of autophagy, namely the ULK kinase complex (UKC) and the Beclin 1/Atg14 complex. We found that CCCP-induced LC3 lipidation could be independent of Beclin 1 and Atg14. In addition, deletion or knockdown of the UKC component FIP200 or Atg13 only led to a partial reduction in LC3 lipidation, indicating that UKC could be also dispensable for this step during CCCP treatment. In contrast, Atg9, which is important for transporting vesicles to early autophagosomal structure, was required for CCCP-induced LC3 lipidation. Taken together, these data suggest that CCCP-induced autophagy and mitophagy depends more critically on Atg9 vesicles than on UKC and Beclin 1/Atg14 complex.« less

Oxidative and Nitrosative Stress in the Metastatic Microenvironment

PubMed Central

Ortega, Ángel L.; Mena, Salvador; Estrela, José M.

2010-01-01

Metastases that are resistant to conventional therapies are the main cause of most cancer-related deaths in humans. Tumor cell heterogeneity, which associates with genomic and phenotypic instability, represents a major problem for cancer therapy. Additional factors, such as the attack of immune cells or organ-specific microenvironments, also influence metastatic cell behavior and the response to therapy. Interaction of cancer and endothelial cells in capillary beds, involving mechanical contact and transient adhesion, is a critical step in the initiation of metastasis. This interaction initiates a cascade of activation pathways that involves cytokines, growth factors, bioactive lipids and reactive oxygen and nitrogen species (ROS and RNS) produced by either the cancer cell or the endothelium. Vascular endothelium-derived NO and H2O2 are cytotoxic for the cancer cells, but also help to identify some critical molecular targets that appear essential for survival of invasive metastatic cell subsets. Surviving cancer cells that extravasate and start colonization of an organ or tissue can still be attacked by macrophages and be influenced by specific intraorgan microenvironment conditions. At all steps; from the primary tumor until colonization of a distant organ; metastatic cells undergo a dynamic process of constant adaptations that may lead to the survival of highly resistant malignant cell subsets. In this sequence of molecular events both ROS and RNS play key roles. PMID:24281071

Measure Guideline. Five Steps to Implement the Public Housing Authority Energy-Efficient Unit Turnover Checklist

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

Liaukus, Christine

2015-07-09

Five Steps to Implementing the PHA Energy Efficient Unit Turnover Package (ARIES, 2014) is a guide to prepare for the installation of energy efficient measures during a typical public housing authority unit turnover. While a PHA is cleaning, painting and readying a unit for a new resident, there is an opportunity to incorporate energy efficiency measures to further improve the unit's performance. The measures on the list are simple enough to be implemented by in-house maintenance personnel, inexpensive enough to be folded into operating expenses without needing capital budget, and fast enough to implement without substantially changing the number ofmore » days between occupancies, a critical factor for organizations where the demand for dwelling units far outweighs the supply. The following guide lays out a five step plan to implement the EE Unit Turnover Package in your PHA, from an initial Self-Assessment through to Package Implementation.« less

Coalbed-methane pilots - timing, design, and analysis

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

Roadifer, R.D.; Moore, T.R.

2009-10-15

Four distinct sequential phases form a recommended process for coalbed-methane (CBM)-prospect assessment: initial screening reconnaissance, pilot testing, and final appraisal. Stepping through these four phases provides a program of progressively ramping work and cost, while creating a series of discrete decision points at which analysis of results and risks can be assessed. While discussing each of these phases in some degree, this paper focuses on the third, the critically important pilot-testing phase. This paper contains roughly 30 specific recommendations and the fundamental rationale behind each recommendation to help ensure that a CBM pilot will fulfill its primary objectives of (1)more » demonstrating whether the subject coal reservoir will desorb and produce consequential gas and (2) gathering the data critical to evaluate and risk the prospect at the next-often most critical-decision point.« less

Structural Transition and Antibody Binding of EBOV GP and ZIKV E Proteins from Pre-Fusion to Fusion-Initiation State.

PubMed

Lappala, Anna; Nishima, Wataru; Miner, Jacob; Fenimore, Paul; Fischer, Will; Hraber, Peter; Zhang, Ming; McMahon, Benjamin; Tung, Chang-Shung

2018-05-10

Membrane fusion proteins are responsible for viral entry into host cells—a crucial first step in viral infection. These proteins undergo large conformational changes from pre-fusion to fusion-initiation structures, and, despite differences in viral genomes and disease etiology, many fusion proteins are arranged as trimers. Structural information for both pre-fusion and fusion-initiation states is critical for understanding virus neutralization by the host immune system. In the case of Ebola virus glycoprotein (EBOV GP) and Zika virus envelope protein (ZIKV E), pre-fusion state structures have been identified experimentally, but only partial structures of fusion-initiation states have been described. While the fusion-initiation structure is in an energetically unfavorable state that is difficult to solve experimentally, the existing structural information combined with computational approaches enabled the modeling of fusion-initiation state structures of both proteins. These structural models provide an improved understanding of four different neutralizing antibodies in the prevention of viral host entry.

Analysis on burnup step effect for evaluating reactor criticality and fuel breeding ratio

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

Saputra, Geby; Purnama, Aditya Rizki; Permana, Sidik

Criticality condition of the reactors is one of the important factors for evaluating reactor operation and nuclear fuel breeding ratio is another factor to show nuclear fuel sustainability. This study analyzes the effect of burnup steps and cycle operation step for evaluating the criticality condition of the reactor as well as the performance of nuclear fuel breeding or breeding ratio (BR). Burnup step is performed based on a day step analysis which is varied from 10 days up to 800 days and for cycle operation from 1 cycle up to 8 cycles reactor operations. In addition, calculation efficiency based onmore » the variation of computer processors to run the analysis in term of time (time efficiency in the calculation) have been also investigated. Optimization method for reactor design analysis which is used a large fast breeder reactor type as a reference case was performed by adopting an established reactor design code of JOINT-FR. The results show a criticality condition becomes higher for smaller burnup step (day) and for breeding ratio becomes less for smaller burnup step (day). Some nuclides contribute to make better criticality when smaller burnup step due to individul nuclide half-live. Calculation time for different burnup step shows a correlation with the time consuming requirement for more details step calculation, although the consuming time is not directly equivalent with the how many time the burnup time step is divided.« less

The roles of SSU processome components and surveillance factors in the initial processing of human ribosomal RNA

PubMed Central

Sloan, Katherine E.; Bohnsack, Markus T.; Schneider, Claudia; Watkins, Nicholas J.

2014-01-01

During eukaryotic ribosome biogenesis, three of the mature ribosomal (r)RNAs are released from a single precursor transcript (pre-rRNA) by an ordered series of endonucleolytic cleavages and exonucleolytic processing steps. Production of the 18S rRNA requires the removal of the 5′ external transcribed spacer (5′ETS) by endonucleolytic cleavages at sites A0 and A1/site 1. In metazoans, an additional cleavage in the 5′ETS, at site A′, upstream of A0, has also been reported. Here, we have investigated how A′ processing is coordinated with assembly of the early preribosomal complex. We find that only the tUTP (UTP-A) complex is critical for A′ cleavage, while components of the bUTP (UTP-B) and U3 snoRNP are important, but not essential, for efficient processing at this site. All other factors involved in the early stages of 18S rRNA processing that were tested here function downstream from this processing step. Interestingly, we show that the RNA surveillance factors XRN2 and MTR4 are also involved in A′ cleavage in humans. A′ cleavage is largely bypassed when XRN2 is depleted, and we also discover that A′ cleavage is not always the initial processing event in all cell types. Together, our data suggest that A′ cleavage is not a prerequisite for downstream pre-rRNA processing steps and may, in fact, represent a quality control step for initial pre-rRNA transcripts. Furthermore, we show that components of the RNA surveillance machinery, including the exosome and TRAMP complexes, also play key roles in the recycling of excised spacer fragments and degradation of aberrant pre-rRNAs in human cells. PMID:24550520

Electro-Chemical-Mechanical, Low Stress, Automatic Polishing (ECMP) Device (Preprint)

DTIC Science & Technology

2010-01-01

into models that predict mechanical response [ 4 - 6 ]. In addition, surface preparation steps are critical to the imaging of ceramic and hybrid...2p 3/2 peak in the spectral data found in Figure 4 . The Ti 2p 3/2 peak is initially observed at 458.4 eV indicating that titanium is present in its...above 6 acceptable limits for both (average IQ values were higher than 2000). For the titanium samples, the samples processed without applied

A dynamic dual role of IL-2 signaling in the two-step differentiation process of adaptive regulatory T cells.

PubMed

Guo, Zhiyong; Khattar, Mithun; Schroder, Paul M; Miyahara, Yoshihiro; Wang, Guohua; He, Xiaoshung; Chen, Wenhao; Stepkowski, Stanislaw M

2013-04-01

The molecular mechanism of the extrathymic generation of adaptive, or inducible, CD4(+)Foxp3(+) regulatory T cells (iTregs) remains incompletely defined. We show that exposure of splenic CD4(+)CD25(+)Foxp3(-) cells to IL-2, but not other common γ-chain cytokines, resulted in Stat5 phosphorylation and induced Foxp3 expression in ∼10% of the cells. Thus, IL-2/Stat5 signaling may be critical for Foxp3 induction in peripheral CD4(+)CD25(+)Foxp3(-) iTreg precursors. In this study, to further define the role of IL-2 in the formation of iTreg precursors as well as their subsequent Foxp3 expression, we designed a two-step iTreg differentiation model. During the initial "conditioning" step, CD4(+)CD25(-)Foxp3(-) naive T cells were activated by TCR stimulation. Inhibition of IL-2 signaling via Jak3-Stat5 was required during this step to generate CD4(+)CD25(+)Foxp3(-) cells containing iTreg precursors. During the subsequent Foxp3-induction step driven by cytokines, IL-2 was the most potent cytokine to induce Foxp3 expression in these iTreg precursors. This two-step method generated a large number of iTregs with relatively stable expression of Foxp3, which were able to prevent CD4(+)CD45RB(high) cell-mediated colitis in Rag1(-/-) mice. In consideration of this information, whereas initial inhibition of IL-2 signaling upon T cell priming generates iTreg precursors, subsequent activation of IL-2 signaling in these precursors induces the expression of Foxp3. These findings advance the understanding of iTreg differentiation and may facilitate the therapeutic use of iTregs in immune disorders.

How Different kinds of Communication and the Mass Media Affect Tourism.

DTIC Science & Technology

1984-12-01

C. Criticism of the Two-Step Flow Model------------------------------ 38 3. The Multi-Step Flow Model or Theory------- 39 4. One-Step Flow Model or... Criticism of the Two-Step Flow Model Researchers have identified deficiencies in the r,,c-w:er :low-model. McNelly, for instance, se,7s mass...evidence of the relative importance of cc munication on the diffusion flow. 38 Rogers ’as criticized ] the theor-y on the grounds that: neither its

Health inequalities and the health of the poor: what do we know? What can we do?

PubMed Central

Gwatkin, D. R.

2000-01-01

The contents of this theme section of the Bulletin of the World Health Organization on "Inequalities in health" have two objectives: to present the initial findings from a new generation of research that has been undertaken in response to renewed concern for health inequalities; and to stimulate movement for action in order to correct the problems identified by this research. The research findings are presented in the five articles which follow. This Critical Reflection proposes two initial steps for the action needed to alleviate the problem; other suggestions are given by the participants in a Round Table discussion which is published after these articles. The theme section concludes with extracts from the classic writings of the nineteenth-century public health pioneer, William Farr, who is widely credited as one of the founders of the scientific study of health inequalities, together with a commentary. This Critical Reflection contributes to the discussion of the action needed by proposing two initial steps for action. That professionals who give very high priority to the distinct but related objectives of poverty alleviation, inequality reduction, and equity enhancement recognize that their shared concern for the distributional aspects of health policy is far more important than any differences that may divide them. That health policy goals, currently expressed as societal averages, be reformulated so that they point specifically to conditions among the poor and to poor-rich differences. For example, infant mortality rates among the poor or the differences in infant mortality between rich and poor sectors would be more useful indicators than the average infant mortality rates for the whole population. PMID:10686729

Consequence-driven cyber-informed engineering (CCE)

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

Freeman, Sarah G.; St Michel, Curtis; Smith, Robert

The Idaho National Lab (INL) is leading a high-impact, national security-level initiative to reprioritize the way the nation looks at high-consequence risk within the industrial control systems (ICS) environment of the country’s most critical infrastructure and other national assets. The Consequence-driven Cyber-informed Engineering (CCE) effort provides both private and public organizations with the steps required to examine their own environments for high-impact events/risks; identify implementation of key devices and components that facilitate that risk; illuminate specific, plausible cyber attack paths to manipulate these devices; and develop concrete mitigations, protections, and tripwires to address the high-consequence risk. The ultimate goal ofmore » the CCE effort is to help organizations take the steps necessary to thwart cyber attacks from even top-tier, highly resourced adversaries that would result in a catastrophic physical effect. CCE participants are encouraged to work collaboratively with each other and with key U.S. Government (USG) contributors to establish a coalition, maximizing the positive effect of lessons-learned and further contributing to the protection of critical infrastructure and other national assets.« less

Large woody debris and flow resistance in step-pool channels, Cascade Range, Washington

USGS Publications Warehouse

Curran, Janet H.; Wohl, Ellen E.

2003-01-01

Total flow resistance, measured as Darcy-Weisbach f, in 20 step-pool channels with large woody debris (LWD) in Washington, ranged from 5 to 380 during summer low flows. Step risers in the study streams consist of either (1) large and relatively immobile woody debris, bedrock, or roots that form fixed, or “forced,” steps, or (2) smaller and relatively mobile wood or clasts, or a mixture of both, arranged across the channel by the stream. Flow resistance in step-pool channels may be partitioned into grain, form, and spill resistance. Grain resistance is calculated as a function of particle size, and form resistance is calculated as large woody debris drag. Combined, grain and form resistance account for less than 10% of the total flow resistance. We initially assumed that the substantial remaining portion is spill resistance attributable to steps. However, measured step characteristics could not explain between-reach variations in flow resistance. This suggests that other factors may be significant; the coefficient of variation of the hydraulic radius explained 43% of the variation in friction factors between streams, for example. Large woody debris generates form resistance on step treads and spill resistance at step risers. Because the form resistance of step-pool channels is relatively minor compared to spill resistance and because wood in steps accentuates spill resistance by increasing step height, we suggest that wood in step risers influences channel hydraulics more than wood elsewhere in the channel. Hence, the distribution and function, not just abundance, of large woody debris is critical in steep, step-pool channels.

A first step in understanding an invasive weed through its genes: an EST analysis of invasive Centaurea maculosa.

PubMed

Broz, Amanda K; Broeckling, Corey D; He, Ji; Dai, Xinbin; Zhao, Patrick X; Vivanco, Jorge M

2007-05-24

The economic and biological implications of plant invasion are overwhelming; however, the processes by which plants become successful invaders are not well understood. Limited genetic resources are available for most invasive and weedy species, making it difficult to study molecular and genetic aspects that may be associated with invasion. As an initial step towards understanding the molecular mechanisms by which plants become invasive, we have generated a normalized Expressed Sequence Tag (EST) library comprising seven invasive populations of Centaurea maculosa, an invasive aster in North America. Seventy-seven percent of the 4423 unique transcripts showed significant similarity to existing proteins in the NCBI database and could be grouped based on gene ontology assignments. The C. maculosa EST library represents an initial step towards looking at gene-specific expression in this species, and will pave the way for creation of other resources such as microarray chips that can help provide a view of global gene expression in invasive C. maculosa and its native counterparts. To our knowledge, this is the first published set of ESTs derived from an invasive weed that will be targeted to study invasive behavior. Understanding the genetic basis of evolution for increased invasiveness in exotic plants is critical to understanding the mechanisms through which exotic invasions occur.

The Impact of a Community-Based Chronic Disease Prevention Initiative: Evaluation Findings from "Steps to Health King County"

ERIC Educational Resources Information Center

Cheadle, Allen; Bourcier, Emily; Krieger, James; Beery, William; Smyser, Michael; Vinh, Diana V.; Lessler, Dan; Alfonsi, Lorrie

2011-01-01

"Steps to Health King County" ("Steps KC"; Seattle, Washington) was one of 40 community-level initiatives funded in 2003 as part of the "Steps to a HealthierUS" initiative. "Steps KC" goals included reducing the impact of chronic diseases through a comprehensive, coordinated approach and reducing health…

A National Cohort Study of U.S. Medical School Students Who Initially Failed Step 1 of the United States Medical Licensing Examination

PubMed Central

Andriole, Dorothy A.; Jeffe, Donna B.

2012-01-01

Purpose To describe educational outcomes for a national cohort of U.S. medical students who initially failed Step 1 of the United States Medical Licensing Examination Method The authors analyzed de-identified, individualized records for the 1993–2000 cohort of U.S. medical school matriculants who both initially failed Step l and were no longer in medical school as of March 2, 2009, using multivariable logistic regression to identify factors associated with attempting, and initially passing, Step 2 Clinical Knowledge (CK). Results Of 6,594 students who failed Step l, 5,985 (90.8%) took Step 2CK. Women and Asian/Pacific Islander students were more likely to attempt Step 2CK; more recent matriculants and students with lower failing Step 1 scores were less likely. Of the 5,985 students who attempted Step 2CK, 4,168 (69.6%) initially passed. Women, students with higher Medical College Admission Test scores, and more recent matriculants were more likely to pass Step 2CK; Asian/Pacific Islander students, underrepresented minority students, older students, and students with lower failing Step 1 scores were less likely. Ninety percent of students in the study sample (5,952/6,594) ultimately graduated from medical school, including 99.5% (4,148/4,168) of those who initially passed, 96.7% (1,757/1,817) of those who initially failed, and 7.7% (47/609) of those who never attempted Step 2CK. Conclusions The authors identified variables associated with educational outcomes among students who failed Step l. These findings can inform medical schools’ efforts to develop tailored interventions to maximize the likelihood that students will take Step 2CK and pass it on the first attempt. PMID:22361789

Intensive care unit quality improvement: a "how-to" guide for the interdisciplinary team.

PubMed

Curtis, J Randall; Cook, Deborah J; Wall, Richard J; Angus, Derek C; Bion, Julian; Kacmarek, Robert; Kane-Gill, Sandra L; Kirchhoff, Karin T; Levy, Mitchell; Mitchell, Pamela H; Moreno, Rui; Pronovost, Peter; Puntillo, Kathleen

2006-01-01

Quality improvement is an important activity for all members of the interdisciplinary critical care team. Although an increasing number of resources are available to guide clinicians, quality improvement activities can be overwhelming. Therefore, the Society of Critical Care Medicine charged this Outcomes Task Force with creating a "how-to" guide that focuses on critical care, summarizes key concepts, and outlines a practical approach to the development, implementation, evaluation, and maintenance of an interdisciplinary quality improvement program in the intensive care unit. The task force met in person twice and by conference call twice to write this document. We also conducted a literature search on "quality improvement" and "critical care or intensive care" and searched online for additional resources. DATA SYNTHESIS AND OVERVIEW: We present an overview of quality improvement in the intensive care unit setting and then describe the following steps for initiating or improving an interdisciplinary critical care quality improvement program: a) identify local motivation, support teamwork, and develop strong leadership; b) prioritize potential projects and choose the first target; c) operationalize the measures, build support for the project, and develop a business plan; d) perform an environmental scan to better understand the problem, potential barriers, opportunities, and resources for the project; e) create a data collection system that accurately measures baseline performance and future improvements; f) create a data reporting system that allows clinicians and others to understand the problem; g) introduce effective strategies to change clinician behavior. In addition, we identify four steps for evaluating and maintaining this program: a) determine whether the target is changing with periodic data collection; b) modify behavior change strategies to improve or sustain improvements; c) focus on interdisciplinary collaboration; and d) develop and sustain support from the hospital leadership. We also identify a number of online resources to complement this overview. This Society of Critical Care Medicine Task Force report provides an overview for clinicians interested in developing or improving a quality improvement program using a step-wise approach. Success depends not only on committed interdisciplinary work that is incremental and continuous but also on strong leadership. Further research is needed to refine the methods and identify the most cost-effective means of improving the quality of health care received by critically ill patients and their families.

A Graphical User Interface for Software-assisted Tracking of Protein Concentration in Dynamic Cellular Protrusions.

PubMed

Saha, Tanumoy; Rathmann, Isabel; Galic, Milos

2017-07-11

Filopodia are dynamic, finger-like cellular protrusions associated with migration and cell-cell communication. In order to better understand the complex signaling mechanisms underlying filopodial initiation, elongation and subsequent stabilization or retraction, it is crucial to determine the spatio-temporal protein activity in these dynamic structures. To analyze protein function in filopodia, we recently developed a semi-automated tracking algorithm that adapts to filopodial shape-changes, thus allowing parallel analysis of protrusion dynamics and relative protein concentration along the whole filopodial length. Here, we present a detailed step-by-step protocol for optimized cell handling, image acquisition and software analysis. We further provide instructions for the use of optional features during image analysis and data representation, as well as troubleshooting guidelines for all critical steps along the way. Finally, we also include a comparison of the described image analysis software with other programs available for filopodia quantification. Together, the presented protocol provides a framework for accurate analysis of protein dynamics in filopodial protrusions using image analysis software.

Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2.

PubMed

Favaro, Marco; Xiao, Hai; Cheng, Tao; Goddard, William A; Yano, Junko; Crumlin, Ethan J

2017-06-27

A national priority is to convert CO 2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO 2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO 2 in the physisorbed configuration at 298 K, and we show that this suboxide is essential for converting to the chemisorbed CO 2 in the presence of water as the first step toward CO 2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts.

Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2

PubMed Central

Favaro, Marco; Yano, Junko; Crumlin, Ethan J.

2017-01-01

A national priority is to convert CO2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO2 in the physisorbed configuration at 298 K, and we show that this suboxide is essential for converting to the chemisorbed CO2 in the presence of water as the first step toward CO2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts. PMID:28607092

Bonabeau model on a fully connected graph

NASA Astrophysics Data System (ADS)

Malarz, K.; Stauffer, D.; Kułakowski, K.

2006-03-01

Numerical simulations are reported on the Bonabeau model on a fully connected graph, where spatial degrees of freedom are absent. The control parameter is the memory factor f. The phase transition is observed at the dispersion of the agents power hi. The critical value fC shows a hysteretic behavior with respect to the initial distribution of hi. fC decreases with the system size; this decrease can be compensated by a greater number of fights between a global reduction of the distribution width of hi. The latter step is equivalent to a partial forgetting.

Host epithelial-viral interactions as cause and cure for asthma.

PubMed

Holtzman, Michael J; Patel, Dhara A; Zhang, Yong; Patel, Anand C

2011-08-01

Research on the pathogenesis of asthma has concentrated on initial stimuli, genetic susceptibilities, adaptive immune responses, and end-organ alterations (particularly in airway mucous cells and smooth muscle) as critical steps leading to disease. Recent evidence indicates that the innate immune cell response to respiratory viruses also contributes to the development of inflammatory airway disease. We further develop this concept by raising the issue that the interaction between host airway epithelial cells and respiratory viruses is another aspect of innate immunity that is also a critical determinant of asthma. We also introduce a rationale for how antiviral performance at the epithelial cell level might be improved to prevent acute infectious illness and chronic inflammatory disease caused by respiratory viruses. Copyright © 2011 Elsevier Ltd. All rights reserved.

Case study of evaluations that go beyond clinical outcomes to assess quality improvement diabetes programmes using the Diabetes Evaluation Framework for Innovative National Evaluations (DEFINE).

PubMed

Paquette-Warren, Jann; Harris, Stewart B; Naqshbandi Hayward, Mariam; Tompkins, Jordan W

2016-10-01

Investments in efforts to reduce the burden of diabetes on patients and health care are critical; however, more evaluation is needed to provide evidence that informs and supports future policies and programmes. The newly developed Diabetes Evaluation Framework for Innovative National Evaluations (DEFINE) incorporates the theoretical concepts needed to facilitate the capture of critical information to guide investments, policy and programmatic decision making. The aim of the study is to assess the applicability and value of DEFINE in comprehensive real-world evaluation. Using a critical and positivist approach, this intrinsic and collective case study retrospectively examines two naturalistic evaluations to demonstrate how DEFINE could be used when conducting real-world comprehensive evaluations in health care settings. The variability between the cases and the evaluation designs are described and aligned to the DEFINE goals, steps and sub-steps. The majority of the theoretical steps of DEFINE were exemplified in both cases, although limited for knowledge translation efforts. Application of DEFINE to evaluate diverse programmes that target various chronic diseases is needed to further test the inclusivity and built-in flexibility of DEFINE and its role in encouraging more comprehensive knowledge translation. This case study shows how DEFINE could be used to structure or guide comprehensive evaluations of programmes and initiatives implemented in health care settings and support scale-up of successful innovations. Future use of the framework will continue to strengthen its value in guiding programme evaluation and informing health policy to reduce the burden of diabetes and other chronic diseases. © 2016 The Authors. Journal of Evaluation in Clinical Practice published by John Wiley & Sons, Ltd.

Case study of evaluations that go beyond clinical outcomes to assess quality improvement diabetes programmes using the Diabetes Evaluation Framework for Innovative National Evaluations (DEFINE)

PubMed Central

Harris, Stewart B.; Naqshbandi Hayward, Mariam; Tompkins, Jordan W.

2016-01-01

Abstract Rationale, aims and objectives Investments in efforts to reduce the burden of diabetes on patients and health care are critical; however, more evaluation is needed to provide evidence that informs and supports future policies and programmes. The newly developed Diabetes Evaluation Framework for Innovative National Evaluations (DEFINE) incorporates the theoretical concepts needed to facilitate the capture of critical information to guide investments, policy and programmatic decision making. The aim of the study is to assess the applicability and value of DEFINE in comprehensive real‐world evaluation. Method Using a critical and positivist approach, this intrinsic and collective case study retrospectively examines two naturalistic evaluations to demonstrate how DEFINE could be used when conducting real‐world comprehensive evaluations in health care settings. Results The variability between the cases and the evaluation designs are described and aligned to the DEFINE goals, steps and sub‐steps. The majority of the theoretical steps of DEFINE were exemplified in both cases, although limited for knowledge translation efforts. Application of DEFINE to evaluate diverse programmes that target various chronic diseases is needed to further test the inclusivity and built‐in flexibility of DEFINE and its role in encouraging more comprehensive knowledge translation. Conclusions This case study shows how DEFINE could be used to structure or guide comprehensive evaluations of programmes and initiatives implemented in health care settings and support scale‐up of successful innovations. Future use of the framework will continue to strengthen its value in guiding programme evaluation and informing health policy to reduce the burden of diabetes and other chronic diseases. PMID:26804339

Subharmonic and fundamental high amplitude excitation of an axisymmetric jet

NASA Technical Reports Server (NTRS)

Raman, Ganesh; Rice, Edward J.

1989-01-01

A circular jet was excited simultaneously by two different harmonically related tones. Data for three pairs of Strouhal numbers (St(D) = f*D/U (sub j) = 0.2 and 0.4, 0.3 and 0.6, 0.4 and 0.8). For each case the initial phase difference between the two waves was varied in steps of 45 deg, for one full cycle and the level of the fundamental and subharmonic forcing were varied independently over the range of 0.1 to 7 percent of the jet exit velocity. Our initial findings concurred with published findings, such as a critical level of the fundamental is required for subharmonic augmentation, the initial phase difference is critical in determining whether the subharmonic is augmented or suppressed. The detailed documentation of several aspects of this phenomenon all measured in one and the same experimental facility in a controlled manner, bring out several important points that eluded previous researchers: (1) At high amplitudes of the fundamental and subharmonic forcing levels the subharmonic augmentation is independent of the initial phase difference. (2) Contrary to the earlier belief that stable pairing could be produced only with an initial laminar boundary layer, the present work shows that by the two-frequency excitation method this phenomenon can be induced over a range of conditions for a jet with an initially turbulent boundary layer. (3) It is seen that two-frequency excitation is indeed more effective than single frequency excitation in jet mixing enhancement. Higher spreading rates seem to go along with higher subharmonic levels.

Errors in Postural Preparation Lead to Increased Choice Reaction Times for Step Initiation in Older Adults

PubMed Central

Nutt, John G.; Horak, Fay B.

2011-01-01

Background. This study asked whether older adults were more likely than younger adults to err in the initial direction of their anticipatory postural adjustment (APA) prior to a step (indicating a motor program error), whether initial motor program errors accounted for reaction time differences for step initiation, and whether initial motor program errors were linked to inhibitory failure. Methods. In a stepping task with choice reaction time and simple reaction time conditions, we measured forces under the feet to quantify APA onset and step latency and we used body kinematics to quantify forward movement of center of mass and length of first step. Results. Trials with APA errors were almost three times as common for older adults as for younger adults, and they were nine times more likely in choice reaction time trials than in simple reaction time trials. In trials with APA errors, step latency was delayed, correlation between APA onset and step latency was diminished, and forward motion of the center of mass prior to the step was increased. Participants with more APA errors tended to have worse Stroop interference scores, regardless of age. Conclusions. The results support the hypothesis that findings of slow choice reaction time step initiation in older adults are attributable to inclusion of trials with incorrect initial motor preparation and that these errors are caused by deficits in response inhibition. By extension, the results also suggest that mixing of trials with correct and incorrect initial motor preparation might explain apparent choice reaction time slowing with age in upper limb tasks. PMID:21498431

Investigation of infrared radiation in rubidium vapor upon two-photon and step-by-step excitations of the initial level

NASA Astrophysics Data System (ADS)

Bimagambetov, T. S.

2011-12-01

Stimulated infrared (IR) 5.231-μm line radiation is obtained upon two-photon and step-by-step excitations of the initial level. Dependences of the line power on the concentration of atoms and laser frequency are investigated. The mechanism of initial level occupation is explained.

Contamination control in hybrid microelectronic modules. Identification of critical process and contaminants, part 1

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

Hybrid processes, handling procedures, and materials were examined to identify the critical process steps in which contamination is most likely to occur, to identify the particular contaminants associated with these critical steps, and to propose method for the control of these contaminants.

Differentiation of pernicious anemia from thrombotic thrombocytopenic purpura: The clinical value of subtle pathologic findings.

PubMed

Abbott, Daniel W; Friedman, Kenneth D; Karafin, Matthew S

2016-12-01

Thrombotic thrombocytopenic purpura (TTP) is a microangiopathic hemolytic anemia that requires emergent treatment with plasma exchange and is one of the most important conditions for which apheresis service professionals are consulted. Careful interpretation of initial laboratory values and the peripheral blood smear is a critical first step to determining the need for plasma exchange because other conditions can show deceptively similar red cell morphology, and ADAMTS13 levels are often not rapidly available. We report a case of a patient who was initially diagnosed with TTP and treated with plasma exchange based on preliminary laboratory data and a peripheral blood smear that contained bizarre microcytic red blood cells presumed to be schistocytes. The peripheral blood smear was later interpreted by the hematopathologist to be inconsistent with TTP, and further workup led to a diagnosis of severe vitamin B12 deficiency secondary to pernicious anemia. This case highlights the diagnostic complexity of thrombotic microangiopathies and the importance of a critical evaluation of the blood smear and presenting laboratory data when there is a concern for TTP. Copyright © 2016 Elsevier Ltd. All rights reserved.

Proposed strategies for designing sustainable high-rise apartment buildings in Ho Chi Minh City responding to critical urban issues

NASA Astrophysics Data System (ADS)

Truong, Nguyen Hoang Long; Huan Giang, Ngoc; Binh Duong, Trong

2018-03-01

This paper aims at finding practical strategies for designing sustainable high-rise apartment buildings in Ho Chi Minh City responding to varied municipal issues. Two steps are made. Step-1 identifies the critical issues of Ho Chi Minh City which are associated with high-rise apartment building projects. Step-2 finds potential and applicable strategies which are solutions for the critical issues in Step-1 with reference of seven selected assessment methods. The study finds the set of 58 strategies applicable to designing sustainable high-rise apartment buildings in Ho Chi Minh City.

Theoretical Basis for Estimated Test Times and Conditions for Drop Tower and Space-Based Droplet Burning Experiments With Methanol and N-Heptane

NASA Technical Reports Server (NTRS)

Marchese, Anthony J.; Dryer, Fredrick L.; Choi, Mun Y.

1994-01-01

In order to develop an extensive envelope of test conditions for NASA's space-based Droplet Combustion Experiment (DCE) as well those droplet experiments which can be performed using a drop tower, the transient vaporization and combustion of methanol and n-heptane droplets were simulated using a recently developed fully time-dependent, spherically symmetric droplet combustion model. The transient vaporization of methanol and n-heptane was modeled to characterize the instantaneous gas phase composition surrounding the droplet prior to the introduction of an ignition source. The results for methanol/air showed that the entire gas phase surrounding a 2 mm methanol droplet deployed in zero-g .quickly falls outside the lean flammability limit. The gas phase surrounding an identically-sized n-heptane droplet, on the other hand, remains flammable. The combustion of methanol was then modeled considering a detailed gas phase chemical kinetic mechanism (168 steps, 26 species) and the effect of the dissolution of flame-generated water into the liquid droplet. These results were used to determine the critical ignition diameter required to achieve quasi-steady droplet combustion in a given oxidizing environment. For droplet diameters greater than the critical ignition diameter, the model predicted a finite diameter at which the flame would extinguish. These extinction diameters were found to vary significantly with initial droplet diameter. This phenomenon appears to be unique to the transient heat transfer, mass transfer and chemical kinetics of the system and thus has not been reported elsewhere to date. The extinction diameter was also shown to vary significantly with the liquid phase Lewis number since the amount of water present in the droplet at extinction is largely governed by the rate at which water is transported into the droplet via mass diffusion. Finally, the numerical results for n-heptane combustion were obtained using both 2 step and 96 step semi-emperical chemical kinetic mechanisms. Neither mechanism exhibited the variation of extinction diameter with initial diameter.

A first step in understanding an invasive weed through its genes: an EST analysis of invasive Centaurea maculosa

PubMed Central

Broz, Amanda K; Broeckling, Corey D; He, Ji; Dai, Xinbin; Zhao, Patrick X; Vivanco, Jorge M

2007-01-01

Background The economic and biological implications of plant invasion are overwhelming; however, the processes by which plants become successful invaders are not well understood. Limited genetic resources are available for most invasive and weedy species, making it difficult to study molecular and genetic aspects that may be associated with invasion. Results As an initial step towards understanding the molecular mechanisms by which plants become invasive, we have generated a normalized Expressed Sequence Tag (EST) library comprising seven invasive populations of Centaurea maculosa, an invasive aster in North America. Seventy-seven percent of the 4423 unique transcripts showed significant similarity to existing proteins in the NCBI database and could be grouped based on gene ontology assignments. Conclusion The C. maculosa EST library represents an initial step towards looking at gene-specific expression in this species, and will pave the way for creation of other resources such as microarray chips that can help provide a view of global gene expression in invasive C. maculosa and its native counterparts. To our knowledge, this is the first published set of ESTs derived from an invasive weed that will be targeted to study invasive behavior. Understanding the genetic basis of evolution for increased invasiveness in exotic plants is critical to understanding the mechanisms through which exotic invasions occur. PMID:17524143

"Nano" Scale Biosignatures and the Search for Extraterrestrial Life

NASA Technical Reports Server (NTRS)

Oehler, D. Z.; Robert, F.; Meibom, A.; Mostefaoui, S.; Selo, M.; Walter, M. R.; Sugitani, K.; Allwood, A.; Mimura, K.; Gibson, E. K.

2008-01-01

A critical step in the search for remnants of potential life forms on other planets lies in our ability to recognize indigenous fragments of ancient microbes preserved in some of Earth's oldest rocks. To this end, we are building a database of nano-scale chemical and morphological characteristics of some of Earth's oldest organic microfossils. We are primarily using the new technology of Nano-Secondary ion mass spectrometry (NanoSIMS) which provides in-situ, nano-scale elemental analysis of trace quantities of organic residues. The initial step was to characterize element composition of well-preserved, organic microfossils from the late Proterozoic (0.8 Ga) Bitter Springs Formation of Australia. Results from that work provide morphologic detail and nitrogen/carbon ratios that appear to reflect the well-established biological origin of these 0.8 Ga fossils.

Multivariable bio-inspired photonic sensors for non-condensable gases

NASA Astrophysics Data System (ADS)

Potyrailo, Radislav A.; Karker, Nicholas; Carpenter, Michael A.; Minnick, Andrew

2018-02-01

Existing gas sensors often lose their measurement accuracy in practical field applications. To mitigate this significant problem, here, we report a demonstration of fabricated multivariable photonic sensors inspired by a known nanostructure of Morpho butterfly scales for detection of exemplary non-condensable gases such as H2, CO, and CO2. We fabricated bio-inspired nanostructures using conventional photolithography and chemical etching and detected individual gases that were difficult or unrealistic to detect using natural Morpho nanostructures. Such bio-inspired gas sensors are the critical step in the development of new sensors with improved accuracy for diverse operational scenarios. While this report is our initial demonstration of responses of fabricated multivariable sensors to individual gases in pristine laboratory conditions, it is a significant milestone in understanding the next steps toward field tests and practical applications of these sensors.

Single-Chain Folding of Synthetic Polymers: A Critical Update.

PubMed

Altintas, Ozcan; Barner-Kowollik, Christopher

2015-11-23

The current contribution serves as a critical update to a previous feature article from us (Macromol. Rapid Commun. 2012, 33, 958-971), and highlights the latest advances in the preparation of single chain polymeric nanoparticles and initial-yet promising-attempts towards mimicking the structure of natural biomacromolecules via single-chain folding of well-defined linear polymers via so-called single chain selective point folding and repeat unit folding. The contribution covers selected examples from the literature published up to ca. September 2015. Our aim is not to provide an exhaustive review but rather highlight a selection of new and exciting examples for single-chain folding based on advanced macromolecular precision chemistry. Initially, the discussion focuses on the synthesis and characterization of single-chain folded structures via selective point folding. The second part of the feature article addresses the folding of well-defined single-chain polymers by means of repeat unit folding. The current state of the art in the field of single-chain folding indicates that repeat unit folding-driven nanoparticle preparation is well-advanced, while initial encouraging steps towards building selective point folding systems have been taken. In addition, a summary of the-in our view-open key questions is provided that may guide future biomimetic design efforts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Postural adjustment errors during lateral step initiation in older and younger adults

PubMed Central

Sparto, Patrick J.; Fuhrman, Susan I.; Redfern, Mark S.; Perera, Subashan; Jennings, J. Richard; Furman, Joseph M.

2016-01-01

The purpose was to examine age differences and varying levels of step response inhibition on the performance of a voluntary lateral step initiation task. Seventy older adults (70 – 94 y) and twenty younger adults (21 – 58 y) performed visually-cued step initiation conditions based on direction and spatial location of arrows, ranging from a simple choice reaction time task to a perceptual inhibition task that included incongruous cues about which direction to step (e.g. a left pointing arrow appearing on the right side of a monitor). Evidence of postural adjustment errors and step latencies were recorded from vertical ground reaction forces exerted by the stepping leg. Compared with younger adults, older adults demonstrated greater variability in step behavior, generated more postural adjustment errors during conditions requiring inhibition, and had greater step initiation latencies that increased more than younger adults as the inhibition requirements of the condition became greater. Step task performance was related to clinical balance test performance more than executive function task performance. PMID:25595953

Postural adjustment errors during lateral step initiation in older and younger adults

PubMed Central

Sparto, Patrick J.; Fuhrman, Susan I.; Redfern, Mark S.; Perera, Subashan; Jennings, J. Richard; Furman, Joseph M.

2014-01-01

The purpose was to examine age differences and varying levels of step response inhibition on the performance of a voluntary lateral step initiation task. Seventy older adults (70 – 94 y) and twenty younger adults (21 – 58 y) performed visually-cued step initiation conditions based on direction and spatial location of arrows, ranging from a simple choice reaction time task to a perceptual inhibition task that included incongruous cues about which direction to step (e.g. a left pointing arrow appearing on the right side of a monitor). Evidence of postural adjustment errors and step latencies were recorded from vertical ground reaction forces exerted by the stepping leg. Compared with younger adults, older adults demonstrated greater variability in step behavior, generated more postural adjustment errors during conditions requiring inhibition, and had greater step initiation latencies that increased more than younger adults as the inhibition requirements of the condition became greater. Step task performance was related to clinical balance test performance more than executive function task performance. PMID:25183162

Signal-activated phospholipase regulation of leukocyte chemotaxis.

PubMed

Cathcart, Martha K

2009-04-01

Signal-activated phospholipases are a recent focus of the rapidly growing field of lipid signaling. The extent of their impact on the pathways regulating diverse cell functions is beginning to be appreciated. A critical step in inflammation is the attraction of leukocytes to injured or diseased tissue. Chemotaxis of leukocytes, a requisite process for monocyte and neutrophil extravasation from the blood into tissues, is a critical step for initiating and maintaining inflammation in both acute and chronic settings. Recent studies have identified new important and required roles for two signal-activated phospholipases A2 (PLA2) in regulating chemotaxis. The two intracellular phospholipases, cPLA2alpha (Group IVA) and iPLA2beta (Group VIA), act in parallel to provide distinct lipid mediators at different intracellular sites that are both required for leukocytes to migrate toward the chemokine monocyte chemoattractant protein-1. This review will summarize the separate roles of these phospholipases as well as what is currently known about the influence of two other classes of intracellular signal-activated phospholipases, phospholipase C and phospholipase D, in regulating chemotaxis in eukaryotic cells, but particularly in human monocytes. The contributions of these phospholipases to chemotaxis both in vitro and in vivo will be highlighted.

[Internal audit in medical laboratory: what means of control for an effective audit process?].

PubMed

Garcia-Hejl, Carine; Chianéa, Denis; Dedome, Emmanuel; Sanmartin, Nancy; Bugier, Sarah; Linard, Cyril; Foissaud, Vincent; Vest, Philippe

2013-01-01

To prepare the French Accreditation Committee (COFRAC) visit for initial certification of our medical laboratory, our direction evaluated its quality management system (QMS) and all its technical activities. This evaluation was performed owing an internal audit. This audit was outsourced. Auditors had an expertise in audit, a whole knowledge of biological standards and were independent. Several nonconformities were identified at that time, including a lack of control of several steps of the internal audit process. Hence, necessary corrective actions were taken in order to meet the requirements of standards, in particular, the formalization of all stages, from the audit program, to the implementation, review and follow-up of the corrective actions taken, and also the implementation of the resources needed to carry out audits in a pre-established timing. To ensure an optimum control of each step, the main concepts of risk management were applied: process approach, root cause analysis, effects and criticality analysis (FMECA). After a critical analysis of our practices, this methodology allowed us to define our "internal audit" process, then to formalize it and to follow it up, with a whole documentary system.

Characteristics of U.S. Veteran Patients with Major Depressive Disorder who require "next-step" treatments: A VAST-D report.

PubMed

Zisook, Sidney; Tal, Ilanit; Weingart, Kimberly; Hicks, Paul; Davis, Lori L; Chen, Peijun; Yoon, Jean; Johnson, Gary R; Vertrees, Julia E; Rao, Sanjai; Pilkinton, Patricia D; Wilcox, James A; Sapra, Mamta; Iranmanesh, Ali; Huang, Grant D; Mohamed, Somaia

2016-12-01

Finding effective and lasting treatments for patients with Major Depressive Disorder (MDD) that fail to respond optimally to initial standard treatment is a critical public health imperative. Understanding the nature and characteristics of patients prior to initiating "next-step" treatment is an important component of identifying which specific treatments are best suited for individual patients. We describe clinical features and demographic characteristics of a sample of Veterans who enrolled in a "next-step" clinical trial after failing to achieve an optimal outcome from at least one well-delivered antidepressant trial. 1522 Veteran outpatients with nonpsychotic MDD completed assessments prior to being randomized to study treatment. Data is summarized and presented in terms of demographic, social, historical and clinical features and compared to a similar, non-Veteran sample. Participants were largely male and white, with about half unmarried and half unemployed. They were moderately severely depressed, with about one-third reporting recent suicidal ideation. More than half had chronic and/or recurrent depression. General medical and psychiatric comorbidities were highly prevalent, particularly PTSD. Many had histories of childhood adversity and bereavement. Participants were impaired in multiple domains of their lives and had negative self-worth. These results may not be generalizable to females, and some characteristics may be specific to Veterans of US military service. There was insufficient data on age of clinical onset and depression subtypes, and three novel measures were not psychometrically validated. Characterizing VAST-D participants provides important information to help clinicians understand features that may optimize "next-step" MDD treatments. Published by Elsevier B.V.

Moral distress experienced by health care professionals who provide home-based palliative care.

PubMed

Brazil, Kevin; Kassalainen, Sharon; Ploeg, Jenny; Marshall, Denise

2010-11-01

Health care providers regularly encounter situations of moral conflict and distress in their practice. Moral distress may result in unfavorable outcomes for both health care providers and those in their care. The purpose of this study was to examine the experience of moral distress from a broad range of health care occupations that provide home-based palliative care as the initial step of addressing the issue. A critical incident approach was used in qualitative interviews to elicit the experiences on moral distress from 18 health care providers drawn from five home visiting organizations in south central Ontario, Canada. Most participants described at least two critical incidents in their interview generating a total of 47 critical incidents. Analyses of the critical incidents revealed 11 issues that triggered moral distress which clustered into three themes, (a) the role of informal caregivers, b) challenging clinical situations and (c) service delivery issues. The findings suggest that the training and practice environments for health care providers need to be designed to recognize the moral challenges related to day-to-day practice. Copyright © 2010 Elsevier Ltd. All rights reserved.

Step-to-step spatiotemporal variables and ground reaction forces of intra-individual fastest sprinting in a single session.

PubMed

Nagahara, Ryu; Mizutani, Mirai; Matsuo, Akifumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo

2018-06-01

We aimed to investigate the step-to-step spatiotemporal variables and ground reaction forces during the acceleration phase for characterising intra-individual fastest sprinting within a single session. Step-to-step spatiotemporal variables and ground reaction forces produced by 15 male athletes were measured over a 50-m distance during repeated (three to five) 60-m sprints using a long force platform system. Differences in measured variables between the fastest and slowest trials were examined at each step until the 22nd step using a magnitude-based inferences approach. There were possibly-most likely higher running speed and step frequency (2nd to 22nd steps) and shorter support time (all steps) in the fastest trial than in the slowest trial. Moreover, for the fastest trial there were likely-very likely greater mean propulsive force during the initial four steps and possibly-very likely larger mean net anterior-posterior force until the 17th step. The current results demonstrate that better sprinting performance within a single session is probably achieved by 1) a high step frequency (except the initial step) with short support time at all steps, 2) exerting a greater mean propulsive force during initial acceleration, and 3) producing a greater mean net anterior-posterior force during initial and middle acceleration.

Viral capsomere structure, surface processes and growth kinetics in the crystallization of macromolecular crystals visualized by in situ atomic force microscopy

NASA Astrophysics Data System (ADS)

Malkin, A. J.; Kuznetsov, Yu. G.; McPherson, A.

2001-11-01

In situ atomic force microscopy (AFM) was used to investigate surface evolution during the growth of single crystals of turnip yellow mosaic virus (TYMV), cucumber mosaic virus (CMV) and glucose isomerase. Growth of these crystals proceeded by two-dimensional (2D) nucleation. For glucose isomerase, from supersaturation dependencies of tangential step rates and critical step length, the kinetic coefficients of the steps and the surface free energy of the step edge were calculated for different crystallographic directions. The molecular structure of the step edges, the adsorption of individual virus particles and their aggregates, and the initial stages of formation of 2D nuclei on the surfaces of TYMV and CMV crystals were recorded. The surfaces of individual TYMV virions within crystals were visualized, and hexameric and pentameric capsomers of the T=3 capsids were clearly resolved. This, so far as we are aware, is the first direct visualization of the capsomere structure of a virus by AFM. In the course of recording the in situ development of the TYMV crystals, a profound restructuring of the surface arrangement was observed. This transformation was highly cooperative in nature, but the transitions were unambiguous and readily explicable in terms of an organized loss of classes of virus particles from specific lattice positions.

The STEP database through the end-users eyes--USABILITY STUDY.

PubMed

Salunke, Smita; Tuleu, Catherine

2015-08-15

The user-designed database of Safety and Toxicity of Excipients for Paediatrics ("STEP") is created to address the shared need of drug development community to access the relevant information of excipients effortlessly. Usability testing was performed to validate if the database satisfies the need of the end-users. Evaluation framework was developed to assess the usability. The participants performed scenario based tasks and provided feedback and post-session usability ratings. Failure Mode Effect Analysis (FMEA) was performed to prioritize the problems and improvements to the STEP database design and functionalities. The study revealed several design vulnerabilities. Tasks such as limiting the results, running complex queries, location of data and registering to access the database were challenging. The three critical attributes identified to have impact on the usability of the STEP database included (1) content and presentation (2) the navigation and search features (3) potential end-users. Evaluation framework proved to be an effective method for evaluating database effectiveness and user satisfaction. This study provides strong initial support for the usability of the STEP database. Recommendations would be incorporated into the refinement of the database to improve its usability and increase user participation towards the advancement of the database. Copyright © 2015 Elsevier B.V. All rights reserved.

A Guide for Designing and Analyzing RNA-Seq Data.

PubMed

Chatterjee, Aniruddha; Ahn, Antonio; Rodger, Euan J; Stockwell, Peter A; Eccles, Michael R

2018-01-01

The identity of a cell or an organism is at least in part defined by its gene expression and therefore analyzing gene expression remains one of the most frequently performed experimental techniques in molecular biology. The development of the RNA-Sequencing (RNA-Seq) method allows an unprecedented opportunity to analyze expression of protein-coding, noncoding RNA and also de novo transcript assembly of a new species or organism. However, the planning and design of RNA-Seq experiments has important implications for addressing the desired biological question and maximizing the value of the data obtained. In addition, RNA-Seq generates a huge volume of data and accurate analysis of this data involves several different steps and choices of tools. This can be challenging and overwhelming, especially for bench scientists. In this chapter, we describe an entire workflow for performing RNA-Seq experiments. We describe critical aspects of wet lab experiments such as RNA isolation, library preparation and the initial design of an experiment. Further, we provide a step-by-step description of the bioinformatics workflow for different steps involved in RNA-Seq data analysis. This includes power calculations, setting up a computational environment, acquisition and processing of publicly available data if desired, quality control measures, preprocessing steps for the raw data, differential expression analysis, and data visualization. We particularly mention important considerations for each step to provide a guide for designing and analyzing RNA-Seq data.

Modelling the graphite fracture mechanisms

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

Jacquemoud, C.; Marie, S.; Nedelec, M.

2012-07-01

In order to define a design criterion for graphite components, it is important to identify the physical phenomena responsible for the graphite fracture, to include them in a more effective modelling. In a first step, a large panel of experiments have been realised in order to build up an important database; results of tensile tests, 3 and 4 point bending tests on smooth and notched specimens have been analysed and have demonstrated an important geometry related effects on the behavior up to fracture. Then, first simulations with an elastic or an elastoplastic bilinear constitutive law have not made it possiblemore » to simulate the experimental fracture stress variations with the specimen geometry, the fracture mechanisms of the graphite being at the microstructural scale. That is the reason why a specific F.E. model of the graphite structure has been developed in which every graphite grain has been meshed independently, the crack initiation along the basal plane of the particles as well as the crack propagation and coalescence have been modelled too. This specific model has been used to test two different approaches for fracture initiation: a critical stress criterion and two criteria of fracture mechanic type. They are all based on crystallographic considerations as a global critical stress criterion gave unsatisfactory results. The criteria of fracture mechanic type being extremely unstable and unable to represent the graphite global behaviour up to the final collapse, the critical stress criterion has been preferred to predict the results of the large range of available experiments, on both smooth and notched specimens. In so doing, the experimental observations have been correctly simulated: the geometry related effects on the experimental fracture stress dispersion, the specimen volume effects on the macroscopic fracture stress and the crack propagation at a constant stress intensity factor. In addition, the parameters of the criterion have been related to experimental observations: the local crack initiation stress of 8 MPa corresponds to the non-linearity apparition on the global behavior observed experimentally and the the maximal critical stress defined for the particle of 30 MPa is equivalent to the fracture stress of notched specimens. This innovative combination of crack modelling and a local crystallographic critical stress criterion made it possible to understand that cleavage initiation and propagation in the graphite microstructure was driven by a mean critical stress criterion. (authors)« less

Anticipatory Postural Adjustment During Self-Initiated, Cued, and Compensatory Stepping in Healthy Older Adults and Patients With Parkinson Disease.

PubMed

Schlenstedt, Christian; Mancini, Martina; Horak, Fay; Peterson, Daniel

2017-07-01

To characterize anticipatory postural adjustments (APAs) across a variety of step initiation tasks in people with Parkinson disease (PD) and healthy subjects. Cross-sectional study. Step initiation was analyzed during self-initiated gait, perceptual cued gait, and compensatory forward stepping after platform perturbation. People with PD were assessed on and off levodopa. University research laboratory. People (N=31) with PD (n=19) and healthy aged-matched subjects (n=12). Not applicable. Mediolateral (ML) size of APAs (calculated from center of pressure recordings), step kinematics, and body alignment. With respect to self-initiated gait, the ML size of APAs was significantly larger during the cued condition and significantly smaller during the compensatory condition (P<.001). Healthy subjects and patients with PD did not differ in body alignment during the stance phase prior to stepping. No significant group effect was found for ML size of APAs between healthy subjects and patients with PD. However, the reduction in APA size from cued to compensatory stepping was significantly less pronounced in PD off medication compared with healthy subjects, as indicated by a significant group by condition interaction effect (P<.01). No significant differences were found comparing patients with PD on and off medications. Specific stepping conditions had a significant effect on the preparation and execution of step initiation. Therefore, APA size should be interpreted with respect to the specific stepping condition. Across-task changes in people with PD were less pronounced compared with healthy subjects. Antiparkinsonian medication did not significantly improve step initiation in this mildly affected PD cohort. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Estimating heterotrophic respiration at large scales: challenges, approaches, and next steps

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

Bond-Lamberty, Benjamin; Epron, Daniel; Harden, Jennifer W.

2016-06-27

Heterotrophic respiration (HR), the aerobic and anaerobic processes mineralizing organic matter, is a key carbon flux but one impossible to measure at scales significantly larger than small experimental plots. This impedes our ability to understand carbon and nutrient cycles, benchmark models, or reliably upscale point measurements. Given that a new generation of highly mechanistic, genomic-specific global models is not imminent, we suggest that a useful step to improve this situation would be the development of "Decomposition Functional Types" (DFTs). Analogous to plant functional types (PFTs), DFTs would abstract and capture important differences in HR metabolism and flux dynamics, allowing modelsmore » to efficiently group and vary these characteristics across space and time. We argue that DFTs should be initially informed by top-down expert opinion, but ultimately developed using bottom-up, data-driven analyses, and provide specific examples of potential dependent and independent variables that could be used. We present and discuss an example clustering analysis to show how model-produced annual HR can be broken into distinct groups associated with global variability in biotic and abiotic factors, and demonstrate that these groups are distinct from already-existing PFTs. A similar analysis, incorporating observational data, could form a basis for future DFTs. Finally, we suggest next steps and critical priorities: collection and synthesis of existing data; more in-depth analyses combining open data with high-performance computing; rigorous testing of analytical results; and planning by the global modeling community for decoupling decomposition from fixed site data. These are all critical steps to build a foundation for DFTs in global models, thus providing the ecological and climate change communities with robust, scalable estimates of HR at large scales.« less

Estimating heterotrophic respiration at large scales: Challenges, approaches, and next steps

DOE PAGES

Bond-Lamberty, Ben; Epron, Daniel; Harden, Jennifer; ...

2016-06-27

Heterotrophic respiration (HR), the aerobic and anaerobic processes mineralizing organic matter, is a key carbon flux but one impossible to measure at scales significantly larger than small experimental plots. This impedes our ability to understand carbon and nutrient cycles, benchmark models, or reliably upscale point measurements. Given that a new generation of highly mechanistic, genomic-specific global models is not imminent, we suggest that a useful step to improve this situation would be the development of Decomposition Functional Types (DFTs). Analogous to plant functional types (PFTs), DFTs would abstract and capture important differences in HR metabolism and flux dynamics, allowing modelersmore » and experimentalists to efficiently group and vary these characteristics across space and time. We argue that DFTs should be initially informed by top-down expert opinion, but ultimately developed using bottom-up, data-driven analyses, and provide specific examples of potential dependent and independent variables that could be used. We present an example clustering analysis to show how annual HR can be broken into distinct groups associated with global variability in biotic and abiotic factors, and demonstrate that these groups are distinct from (but complementary to) already-existing PFTs. A similar analysis incorporating observational data could form the basis for future DFTs. Finally, we suggest next steps and critical priorities: collection and synthesis of existing data; more in-depth analyses combining open data with rigorous testing of analytical results; using point measurements and realistic forcing variables to constrain process-based models; and planning by the global modeling community for decoupling decomposition from fixed site data. Lastly, these are all critical steps to build a foundation for DFTs in global models, thus providing the ecological and climate change communities with robust, scalable estimates of HR.« less

Estimating heterotrophic respiration at large scales: Challenges, approaches, and next steps

USGS Publications Warehouse

Bond-Lamberty, Ben; Epron, Daniel; Harden, Jennifer W.; Harmon, Mark E.; Hoffman, Forrest; Kumar, Jitendra; McGuire, Anthony David; Vargas, Rodrigo

2016-01-01

Heterotrophic respiration (HR), the aerobic and anaerobic processes mineralizing organic matter, is a key carbon flux but one impossible to measure at scales significantly larger than small experimental plots. This impedes our ability to understand carbon and nutrient cycles, benchmark models, or reliably upscale point measurements. Given that a new generation of highly mechanistic, genomic-specific global models is not imminent, we suggest that a useful step to improve this situation would be the development of “Decomposition Functional Types” (DFTs). Analogous to plant functional types (PFTs), DFTs would abstract and capture important differences in HR metabolism and flux dynamics, allowing modelers and experimentalists to efficiently group and vary these characteristics across space and time. We argue that DFTs should be initially informed by top-down expert opinion, but ultimately developed using bottom-up, data-driven analyses, and provide specific examples of potential dependent and independent variables that could be used. We present an example clustering analysis to show how annual HR can be broken into distinct groups associated with global variability in biotic and abiotic factors, and demonstrate that these groups are distinct from (but complementary to) already-existing PFTs. A similar analysis incorporating observational data could form the basis for future DFTs. Finally, we suggest next steps and critical priorities: collection and synthesis of existing data; more in-depth analyses combining open data with rigorous testing of analytical results; using point measurements and realistic forcing variables to constrain process-based models; and planning by the global modeling community for decoupling decomposition from fixed site data. These are all critical steps to build a foundation for DFTs in global models, thus providing the ecological and climate change communities with robust, scalable estimates of HR.

Are Your Students Critically Reading an Opinion Piece? Have Them RATTKISS It!

ERIC Educational Resources Information Center

Snair, Scott

2008-01-01

Scott Snair proposes a mnemonic for students to use when critically examining written opinion. The acronym, RATTKISS, represents a "step-by-step method for understanding and evaluating written opinion." (Contains 1 figure.)

Transcription and methylation analyses of preleukemic promyelocytes indicate a dual role for PML/RARA in leukemia initiation

PubMed Central

Gaillard, Coline; Tokuyasu, Taku A.; Rosen, Galit; Sotzen, Jason; Vitaliano-Prunier, Adeline; Roy, Ritu; Passegué, Emmanuelle; de Thé, Hugues; Figueroa, Maria E.; Kogan, Scott C.

2015-01-01

Acute promyelocytic leukemia is an aggressive malignancy characterized by the accumulation of promyelocytes in the bone marrow. PML/RARA is the primary abnormality implicated in this pathology, but the mechanisms by which this chimeric fusion protein initiates disease are incompletely understood. Identifying PML/RARA targets in vivo is critical for comprehending the road to pathogenesis. Utilizing a novel sorting strategy, we isolated highly purified promyelocyte populations from normal and young preleukemic animals, carried out microarray and methylation profiling analyses, and compared the results from the two groups of animals. Surprisingly, in the absence of secondary lesions, PML/RARA had an overall limited impact on both the transcriptome and methylome. Of interest, we did identify down-regulation of secondary and tertiary granule genes as the first step engaging the myeloid maturation block. Although initially not sufficient to arrest terminal granulopoiesis in vivo, such alterations set the stage for the later, complete differentiation block seen in leukemia. Further, gene set enrichment analysis revealed that PML/RARA promyelocytes exhibit a subtle increase in expression of cell cycle genes, and we show that this leads to both increased proliferation of these cells and expansion of the promyelocyte compartment. Importantly, this proliferation signature was absent from the poorly leukemogenic p50/RARA fusion model, implying a critical role for PML in the altered cell-cycle kinetics and ability to initiate leukemia. Thus, our findings challenge the predominant model in the field and we propose that PML/RARA initiates leukemia by subtly shifting cell fate decisions within the promyelocyte compartment. PMID:26088929

[Comparison between one-step and two-step space closing methods of sliding mechanics using three-dimensional finite element].

PubMed

Han, Yaohui; Mou, Lan; Xu, Gengchi; Yang, Yiqiang; Ge, Zhenlin

2015-03-01

To construct a three-dimensional finite element model comparing between one-step and two-step methods in torque control of anterior teeth during space closure. Dicom image data including maxilla and upper teeth were obtained though cone-beam CT. A three-dimensional model was set up and the maxilla, upper teeth and periodontium were separated using Mimics software. The models were instantiated using Pro/Engineer software, and Abaqus finite element analysis software was used to simulate the sliding mechanics by loading 1.47 Nforce on traction hooks with different heights (2, 4, 6, 8, 10, 12 and 14 mm, respectively) in order to compare the initial displacement between six maxillary anterior teeth (one-step method) and four maxillary anterior teeth (two-step method). When moving anterior teeth bodily, initial displacements of central incisors in two-step method and in one-step method were 29.26 × 10⁻⁶ mm and 15.75 × 10⁻⁶ mm, respectively. The initial displacements of lateral incisors in two-step method and in one-step method were 46.76 × 10(-6) mm and 23.18 × 10(-6) mm, respectively. Under the same amount of light force, the initial displacement of anterior teeth in two-step method was doubled compared with that in one-step method. The root and crown of the canine couldn't obtain the same amount of displacement in one-step method. Two-step method could produce more initial displacement than one-step method. Therefore, two-step method was easier to achieve torque control of the anterior teeth during space closure.

Quality research in radiation oncology: a self-improvement initiative 30 years ahead of its time?

PubMed

Wilson, J Frank; Owen, Jean

2005-12-01

The quality of cancer care in the United States should be better than it is. Society has demanded improvement, but much work remains to be done to define and measure both the current quality of care and the steps needed to optimize such care. Various public and private organizations are directing early efforts toward attempts to determine the quality of selected oncology services as a first step in a broad-based quality improvement process. In contrast, the ACR Patterns of Care Study (PCS) for over 30 years has relied on exemplary voluntary engagement by American radiation oncologists in critical self-assessment and self-improvement as a highly effective pathway to improved practice quality. This article provides an overview of the documented historical and recent impact of PCS research findings on practice and describes the deliberate adaptation of the PCS identity and methodology to the quality-sensitive national environment with the new project name Quality Research in Radiation Oncology. The article concludes with a discussion of the rationale for continuing this unique quality improvement initiative and some of the challenges to this imperative that are being faced.

Role of initial correlation in coarsening of a ferromagnet

NASA Astrophysics Data System (ADS)

Chakraborty, Saikat; Das, Subir K.

2015-06-01

We study the dynamics of ordering in ferromagnets via Monte Carlo simulations of the Ising model, employing the Glauber spin-flip mechanism, in space dimensions d = 2 and 3, on square and simple cubic lattices. Results for the persistence probability and the domain growth are discussed for quenches to various temperatures (Tf) below the critical one (Tc), from different initial temperatures Ti ≥ Tc. In long time limit, for Ti>Tc, the persistence probability exhibits power-law decay with exponents θ ≃ 0.22 and ≃ 0.18 in d = 2 and 3, respectively. For finite Ti, the early time behavior is a different power-law whose life-time diverges and exponent decreases as Ti → Tc. The two steps are connected via power-law as a function of domain length and the crossover to the second step occurs when this characteristic length exceeds the equilibrium correlation length at T = Ti. Ti = Tc is expected to provide a new universality class for which we obtain θ ≡ θc ≃ 0.035 in d = 2 and ≃0.105 in d = 3. The time dependence of the average domain size ℓ, however, is observed to be rather insensitive to the choice of Ti.

Reduced-order aeroelastic model for limit-cycle oscillations in vortex-dominated unsteady airfoil flows

NASA Astrophysics Data System (ADS)

Suresh Babu, Arun Vishnu; Ramesh, Kiran; Gopalarathnam, Ashok

2017-11-01

In previous research, Ramesh et al. (JFM,2014) developed a low-order discrete vortex method for modeling unsteady airfoil flows with intermittent leading edge vortex (LEV) shedding using a leading edge suction parameter (LESP). LEV shedding is initiated using discrete vortices (DVs) whenever the Leading Edge Suction Parameter (LESP) exceeds a critical value. In subsequent research, the method was successfully employed by Ramesh et al. (JFS, 2015) to predict aeroelastic limit-cycle oscillations in airfoil flows dominated by intermittent LEV shedding. When applied to flows that require large number of time steps, the computational cost increases due to the increasing vortex count. In this research, we apply an amalgamation strategy to actively control the DV count, and thereby reduce simulation time. A pair each of LEVs and TEVs are amalgamated at every time step. The ideal pairs for amalgamation are identified based on the requirement that the flowfield in the vicinity of the airfoil is least affected (Spalart, 1988). Instead of placing the amalgamated vortex at the centroid, we place it at an optimal location to ensure that the leading-edge suction and the airfoil bound circulation are conserved. Results of the initial study are promising.

Crossing of the epithelial barriers by Bacillus anthracis: the Known and the Unknown

PubMed Central

Goossens, Pierre L.; Tournier, Jean-Nicolas

2015-01-01

Anthrax, caused by Bacillus anthracis, a Gram-positive spore-forming bacterium, is initiated by the entry of spores into the host body. There are three types of human infection: cutaneous, inhalational, and gastrointestinal. For each form, B. anthracis spores need to cross the cutaneous, respiratory or digestive epithelial barriers, respectively, as a first obligate step to establish infection. Anthrax is a toxi-infection: an association of toxemia and rapidly spreading infection progressing to septicemia. The pathogenicity of Bacillus anthracis mainly depends on two toxins and a capsule. The capsule protects bacilli from the immune system, thus promoting systemic dissemination. The toxins alter host cell signaling, thereby paralyzing the immune response of the host and perturbing the endocrine and endothelial systems. In this review, we will mainly focus on the events and mechanisms leading to crossing of the respiratory epithelial barrier, as the majority of studies have addressed inhalational infection. We will discuss the critical gaps of knowledge that need to be addressed to gain a comprehensive view of the initial steps of inhalational anthrax. We will then discuss the few data available on B. anthracis crossing the cutaneous and digestive epithelia. PMID:26500645

Pulse measurement of the hot spot current in a NbTiN superconducting filament

NASA Astrophysics Data System (ADS)

Harrabi, K.; Mekki, A.; Kunwar, S.; Maneval, J. P.

2018-02-01

We have studied the voltage response of superconducting NbTiN filaments to a step-pulse of over-critical current I > Ic. The current induces the destruction of the Cooper pairs and initiates different mechanisms of dissipation depending on the bath temperature T. For the sample investigated, and for T above a certain T*, not far from Tc, the resistance manifests itself in the form of a phase-slip center, which turns into a normal hot spot (HS) as the step-pulse is given larger amplitudes. However, at all temperatures below T*, the destruction of superconductivity still occurs at Ic(T), but leads directly to an ever-growing HS. By lowering the current amplitude during the pulse, one can produce a steady HS and thus define a threshold HS current Ih(T). That is achieved by combining two levels of current, the first and larger one to initiate an HS, the second one to search for constant voltage response. The double diagram of the functions Ic(T) and Ih(T) was plotted in the T-range Tc/2 < T < Tc, and their crossing found at T* = (8.07 ± 0.07) K.

Training Rapid Stepping Responses in an Individual With Stroke

PubMed Central

Inness, Elizabeth L.; Komar, Janice; Biasin, Louis; Brunton, Karen; Lakhani, Bimal; McIlroy, William E.

2011-01-01

Background and Purpose Compensatory stepping reactions are important responses to prevent a fall following a postural perturbation. People with hemiparesis following a stroke show delayed initiation and execution of stepping reactions and often are found to be unable to initiate these steps with the more-affected limb. This case report describes a targeted training program involving repeated postural perturbations to improve control of compensatory stepping in an individual with stroke. Case Description Compensatory stepping reactions of a 68-year-old man were examined 52 days after left hemorrhagic stroke. He required assistance to prevent a fall in all trials administered during his initial examination because he showed weight-bearing asymmetry (with more weight borne on the more-affected right side), was unable to initiate stepping with the right leg (despite blocking of the left leg in some trials), and demonstrated delayed response times. The patient completed 6 perturbation training sessions (30–60 minutes per session) that aimed to improve preperturbation weight-bearing symmetry, to encourage stepping with the right limb, and to reduce step initiation and completion times. Outcomes Improved efficacy of compensatory stepping reactions with training and reduced reliance on assistance to prevent falling were observed. Improvements were noted in preperturbation asymmetry and step timing. Blocking the left foot was effective in encouraging stepping with the more-affected right foot. Discussion This case report demonstrates potential short-term adaptations in compensatory stepping reactions following perturbation training in an individual with stroke. Future work should investigate the links between improved compensatory step characteristics and fall risk in this vulnerable population. PMID:21511992

Developing Brain Vital Signs: Initial Framework for Monitoring Brain Function Changes Over Time

PubMed Central

Ghosh Hajra, Sujoy; Liu, Careesa C.; Song, Xiaowei; Fickling, Shaun; Liu, Luke E.; Pawlowski, Gabriela; Jorgensen, Janelle K.; Smith, Aynsley M.; Schnaider-Beeri, Michal; Van Den Broek, Rudi; Rizzotti, Rowena; Fisher, Kirk; D'Arcy, Ryan C. N.

2016-01-01

Clinical assessment of brain function relies heavily on indirect behavior-based tests. Unfortunately, behavior-based assessments are subjective and therefore susceptible to several confounding factors. Event-related brain potentials (ERPs), derived from electroencephalography (EEG), are often used to provide objective, physiological measures of brain function. Historically, ERPs have been characterized extensively within research settings, with limited but growing clinical applications. Over the past 20 years, we have developed clinical ERP applications for the evaluation of functional status following serious injury and/or disease. This work has identified an important gap: the need for a clinically accessible framework to evaluate ERP measures. Crucially, this enables baseline measures before brain dysfunction occurs, and might enable the routine collection of brain function metrics in the future much like blood pressure measures today. Here, we propose such a framework for extracting specific ERPs as potential “brain vital signs.” This framework enabled the translation/transformation of complex ERP data into accessible metrics of brain function for wider clinical utilization. To formalize the framework, three essential ERPs were selected as initial indicators: (1) the auditory N100 (Auditory sensation); (2) the auditory oddball P300 (Basic attention); and (3) the auditory speech processing N400 (Cognitive processing). First step validation was conducted on healthy younger and older adults (age range: 22–82 years). Results confirmed specific ERPs at the individual level (86.81–98.96%), verified predictable age-related differences (P300 latency delays in older adults, p < 0.05), and demonstrated successful linear transformation into the proposed brain vital sign (BVS) framework (basic attention latency sub-component of BVS framework reflects delays in older adults, p < 0.05). The findings represent an initial critical step in developing, extracting, and characterizing ERPs as vital signs, critical for subsequent evaluation of dysfunction in conditions like concussion and/or dementia. PMID:27242415

Critical Motor Number for Fractional Steps of Cytoskeletal Filaments in Gliding Assays

PubMed Central

Li, Xin; Lipowsky, Reinhard; Kierfeld, Jan

2012-01-01

In gliding assays, filaments are pulled by molecular motors that are immobilized on a solid surface. By varying the motor density on the surface, one can control the number of motors that pull simultaneously on a single filament. Here, such gliding assays are studied theoretically using Brownian (or Langevin) dynamics simulations and taking the local force balance between motors and filaments as well as the force-dependent velocity of the motors into account. We focus on the filament stepping dynamics and investigate how single motor properties such as stalk elasticity and step size determine the presence or absence of fractional steps of the filaments. We show that each gliding assay can be characterized by a critical motor number, . Because of thermal fluctuations, fractional filament steps are only detectable as long as . The corresponding fractional filament step size is where is the step size of a single motor. We first apply our computational approach to microtubules pulled by kinesin-1 motors. For elastic motor stalks that behave as linear springs with a zero rest length, the critical motor number is found to be , and the corresponding distributions of the filament step sizes are in good agreement with the available experimental data. In general, the critical motor number depends on the elastic stalk properties and is reduced to for linear springs with a nonzero rest length. Furthermore, is shown to depend quadratically on the motor step size . Therefore, gliding assays consisting of actin filaments and myosin-V are predicted to exhibit fractional filament steps up to motor number . Finally, we show that fractional filament steps are also detectable for a fixed average motor number as determined by the surface density (or coverage) of the motors on the substrate surface. PMID:22927953

STUDIES OF THE MECHANISM OF ACTION OF URETHANE IN INITIATING PULMONARY ADENOMAS IN MICE

PubMed Central

Rogers, Stanfield

1957-01-01

The process of carcinogenesis following exposure of mice to urethane is demonstrated in the present work to be intimately related to nucleic acid synthesis. Injection of animals with a DNA hydrolysate immediately prior to a single exposure of the animals to urethane markedly reduced the number of pulmonary adenomas initiated. Aminopterin, known to interfere in nucleic acid synthesis (46), potentiated the carcinogenic action of urethane and this potentiation was blocked by injection of a DNA hydrolysate. Of the components and precursors of nucleic acids the pyrimidine series seemed especially concerned. Alterations in the utilization of oxaloacetate, ureidosuccinic acid, dihydro-orotic acid, orotic acid, cytidylic acid, and thymine appeared to be critical steps in the oncogenic process, following upon the primary disorder of cellular metabolism initiated by the carcinogen. All these substances except oxaloacetate profoundly reduced the number of tumors initiated by urethane. Oxaloacetate potentiated the carcinogenic effect. When these results are viewed together and in relation to known facts concerning nucleic acid synthesis they provide evidence suggesting that the point of action of the carcinogen is in the pathway of nucleic acid synthesis below orotic acid and perhaps at the level of ureidosuccinic acid. The potentiating influence of adenine, 4-amino-5-imidazole carboxamide, and aminopterin, the lack of effect of uracil, and the inhibitory influence of thymine together suggest that DNA rather than RNA is the nucleic acid critical to the oncogenic response of mice to urethane. PMID:13416469

A Comparative Proteome Profile of Female Mouse Gonads Suggests a Tight Link between the Electron Transport Chain and Meiosis Initiation.

PubMed

Shen, Cong; Li, Mingrui; Zhang, Pan; Guo, Yueshuai; Zhang, Hao; Zheng, Bo; Teng, Hui; Zhou, Tao; Guo, Xuejiang; Huo, Ran

2018-01-01

Generation of haploid gametes by meiosis is a unique property of germ cells and is critical for sexual reproduction. Leaving mitosis and entering meiosis is a key step in germ cell development. Several inducers or intrinsic genes are known to be important for meiotic initiation, but the regulation of meiotic initiation, especially at the protein level, is still not well understood. We constructed a comparative proteome profile of female mouse fetal gonads at specific time points (11.5, 12.5, and 13.5 days post coitum), spanning a critical window for initiation of meiosis in female germ cells. We identified 3666 proteins, of which 473 were differentially expressed. Further bioinformatics analysis showed that these differentially expressed proteins were enriched in the mitochondria, especially in the electron transport chain and, notably, 9 proteins in electron transport chain Complex I were differentially expressed. We disrupted the mitochondrial electron transport chain function by adding the complex I inhibitor, rotenone to 11.5 days post coitum female gonads cultured in vitro. This treatment resulted in a decreased proportion of meiotic germ cells, as assessed by staining for histone γH2AX. Rotenone treatment also caused decreased ATP levels, increased reactive oxygen species levels and failure of the germ cells to undergo premeiotic DNA replication. These effects were partially rescued by adding Coenzyme Q10. Taken together, our results suggested that a functional electron transport chain is important for meiosis initiation. Our characterization of the quantitative proteome of female gonads provides an inventory of proteins, useful for understanding the mechanisms of meiosis initiation and female fertility. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

The effect of size and composition on structural transitions in monometallic nanoparticles

NASA Astrophysics Data System (ADS)

Rossi, Kevin; Pavan, Luca; Soon, YeeYeen; Baletto, Francesca

2018-02-01

Predicting the morphological stability of nanoparticles is an essential step towards the accurate modelling of their chemophysical properties. Here we investigate solid-solid transitions in monometallic clusters of 0.5-2.0 nm diameter at finite temperatures and we report the complex dependence of the rearrangement mechanism on the nanoparticle's composition and size. The concerted Lipscomb's Diamond-Square-Diamond mechanisms which connects the decahedral or the cuboctahedral to the icosahedral basins, take place only below a material dependent critical size above which surface diffusion prevails and leads to low-symmetry and defected shapes still belonging to the initial basin.

A model for critical thinking measurement of dental student performance.

PubMed

Johnsen, David C; Finkelstein, Michael W; Marshall, Teresa A; Chalkley, Yvonne M

2009-02-01

The educational application of critical thinking has increased in the last twenty years with programs like problem-based learning. Performance measurement related to the dental student's capacity for critical thinking remains elusive, however. This article offers a model now in use to measure critical thinking applied to patient assessment and treatment planning across the four years of the dental school curriculum and across clinical disciplines. Two elements of the model are described: 1) a critical thinking measurement "cell," and 2) a list of minimally essential steps in critical thinking for patient assessment and treatment planning. Issues pertaining to this model are discussed: adaptations on the path from novice to expert, the role of subjective measurement, variations supportive of the model, and the correlation of individual and institutional assessment. The critical thinking measurement cell consists of interacting performance tasks and measures. The student identifies the step in the process (for example, chief complaint) with objective measurement; the student then applies the step to a patient or case with subjective measurement; the faculty member then combines the objective and subjective measurements into an evaluation on progress toward competence. The activities in the cell are then repeated until all the steps in the process have been addressed. A next task is to determine consistency across the four years and across clinical disciplines.

The Effect of Forward-Facing Steps on Stationary Crossflow Instability Growth and Breakdown

NASA Technical Reports Server (NTRS)

Eppink, Jenna L.

2018-01-01

The e?ect of a forward-facing step on stationary cross?ow transition was studied using standard stereo particle image velocimetry (PIV) and time-resolved PIV. Step heights ranging from 53 to 71% of the boundary-layer thickness were studied in detail. The steps above a critical step height of approximately 60% of the boundary-layer thickness had a signi?cant impact on the stationary cross?ow growth downstream of the step. For the critical cases, the stationary cross?ow amplitude grew suddenly downstream of the step, decayed for a short region, then grew again. The adverse pressure gradient upstream of the step resulted in a region of cross?ow reversal. A secondary set of vortices, rotating in the opposite direction to the primary vortices, developed underneath the uplifted primary vortices. The wall-normal velocity disturbance (V' ) created by these secondary vortices impacted the step, and is believed to feed into the strong vortex that developed downstream of the step. A large but very short negative cross?ow region formed for a short region downstream of the step due to a sharp inboard curvature of the streamlines near the wall. For the larger step height cases, a cross?ow-reversal region formed just downstream of the strong negative cross?ow region. This cross?ow reversal region is believed to play an important role in the growth of the stationary cross?ow vortices downstream of the step, and may be a good indication of the critical forward-facing step height.

Initial Validation of Robotic Operations for In-Space Assembly of a Large Solar Electric Propulsion Transport Vehicle

NASA Technical Reports Server (NTRS)

Komendera, Erik E.; Dorsey, John T.

2017-01-01

Developing a capability for the assembly of large space structures has the potential to increase the capabilities and performance of future space missions and spacecraft while reducing their cost. One such application is a megawatt-class solar electric propulsion (SEP) tug, representing a critical transportation ability for the NASA lunar, Mars, and solar system exploration missions. A series of robotic assembly experiments were recently completed at Langley Research Center (LaRC) that demonstrate most of the assembly steps for the SEP tug concept. The assembly experiments used a core set of robotic capabilities: long-reach manipulation and dexterous manipulation. This paper describes cross-cutting capabilities and technologies for in-space assembly (ISA), applies the ISA approach to a SEP tug, describes the design and development of two assembly demonstration concepts, and summarizes results of two sets of assembly experiments that validate the SEP tug assembly steps.

Cooperation, logistics critical to well control operation in Irian Jaya jungle

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

Gebhardt, F.; Leturno, R.

1996-04-15

Solving a well control problem in remote Irian Jaya, Indonesia, required fast regional and international transportation of both people and equipment. Initial information indicated that the well was experiencing an underground flow with a constant surface pressure because of a shallow hole in the 9 5/8-in. casing. The surface pressure made pipe movement inadvisable until proper pressure control equipment was in place. Several factors contributed to the overall success of this well control project. Atlantic Richfield Indonesia Inc.`s commitment to blowout contingency planning and well control team made it possible to institute a predetermined organizational structure. This organization structure providedmore » a means to gather and evaluate data quickly. Thus, crucial decisions could be made without delay, and proper personnel and equipment were mobilized. This paper reviews the step-by-step process used in this effort.« less

Towards a Competency-based Vision for Construction Safety Education

NASA Astrophysics Data System (ADS)

Pedro, Akeem; Hai Chien, Pham; Park, Chan Sik

2018-04-01

Accidents still prevail in the construction industry, resulting in injuries and fatalities all over the world. Educational programs in construction should deliver safety knowledge and skills to students who will become responsible for ensuring safe construction work environments in the future. However, there is a gap between the competencies current pedagogical approaches target, and those required for safety in practice. This study contributes to addressing this issue in three steps. Firstly, a vision for competency-based construction safety education is conceived. Building upon this, a research scheme to achieve the vision is developed, and the first step of the scheme is initiated in this study. The critical competencies required for safety education are investigated through analyses of literature, and confirmed through surveys with construction and safety management professionals. Results from the study would be useful in establishing and orienting education programs towards current industry safety needs and requirements

Subsurface oxide plays a critical role in CO 2 activation by Cu(111) surfaces to form chemisorbed CO 2, the first step in reduction of CO 2

DOE PAGES

Favaro, Marco; Xiao, Hai; Cheng, Tao; ...

2017-06-12

A national priority is to convert CO 2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO 2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO 2 in the physisorbed configuration at 298 K, and we show that this suboxide ismore » essential for converting to the chemisorbed CO 2 in the presence of water as the first step toward CO 2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts.« less

Risk Assessment Methodology for Water utilities (RAM-W) : the foundation for emergency response planning.

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

Danneels, Jeffrey John

2005-03-01

Concerns about acts of terrorism against critical infrastructures have been on the rise for several years. Critical infrastructures are those physical structures and information systems (including cyber) essential to the minimum operations of the economy and government. The President's Commission on Critical Infrastructure Protection (PCCIP) probed the security of the nation's critical infrastructures. The PCCIP determined the water infrastructure is highly vulnerable to a range of potential attacks. In October 1997, the PCCIP proposed a public/private partnership between the federal government and private industry to improve the protection of the nation's critical infrastructures. In early 2000, the EPA partnered withmore » the Awwa Research Foundation (AwwaRF) and Sandia National Laboratories to create the Risk Assessment Methodology for Water Utilities (RAM-W{trademark}). Soon thereafter, they initiated an effort to create a template and minimum requirements for water utility Emergency Response Plans (ERP). All public water utilities in the US serving populations greater than 3,300 are required to undertaken both a vulnerability assessment and the development of an emergency response plan. This paper explains the initial steps of RAM-W{trademark} and then demonstrates how the security risk assessment is fundamental to the ERP. During the development of RAM-W{trademark}, Sandia performed several security risk assessments at large metropolitan water utilities. As part of the scope of that effort, ERPs at each utility were reviewed to determine how well they addressed significant vulnerabilities uncovered during the risk assessment. The ERP will contain responses to other events as well (e.g. natural disasters) but should address all major findings in the security risk assessment.« less

Single-Cell Analysis Uncovers Extensive Biological Noise in Poliovirus Replication

PubMed Central

Schulte, Michael B.

2014-01-01

ABSTRACT Viral infections often begin with a very small number of initiating particles. Accordingly, the outcome of an infection is likely to be affected by variability in the initial molecular interactions between virus and host. In this study, we investigated the range of outcomes upon infection of single cells. We isolated individual cells infected with poliovirus at low or high multiplicities of infection (MOI) and measured viral genomic replication and infectious viral progeny in each cell. We first determined that at 7 h postinfection, the ratio of positive to negative strands in individual cells varies from 5:1 to more than 190:1, with and average of 20:1, suggesting a significant variability in RNA synthesis. We further found that while virus genome production is higher in cells infected at a high multiplicity, the production of infectious particles is largely independent of the number of viruses infecting each cell. Strikingly, by correlating RNA and particle production within individual infections, we uncovered a significant contribution of stochastic noise to the outcome of infection. At low MOI, stochastic influences appear as kinetic effects which are most critical at the initial steps in infection. At high MOI, stochastic influences appear to dictate the virus's ability to harness cellular resources. We conclude that biological noise is a critical determinant of the overall productivity of viral infections. The distinct nature of stochasticity in the outcome of infection by low and high numbers of viral particles may have important implications for our understanding of the determinants of successful viral infections. IMPORTANCE By correlating genome and particle production in single-cell infections, we elucidated sources of noise in viral infections. When a cell was infected by only a single infectious particle, variation in the kinetics of the initial steps of replication contributed significantly to the overall productivity of the infection. Additionally, variation in the distribution of subcellular resources impacted infections initiated by one or many infectious particles. We also observed that when a cell was infected with multiple particles, more genomes were produced, while particle production was hindered by an apparent cellular resource limit. Understanding variations in viral infections may illuminate the dynamics of infection and pathogenesis and has implications for virus adaptation and evolution. PMID:24648454

Marine Microorganism-Invertebrate Assemblages: Perspectives to Solve the “Supply Problem” in the Initial Steps of Drug Discovery

PubMed Central

Leal, Miguel Costa; Sheridan, Christopher; Osinga, Ronald; Dionísio, Gisela; Rocha, Rui Jorge Miranda; Silva, Bruna; Rosa, Rui; Calado, Ricardo

2014-01-01

The chemical diversity associated with marine natural products (MNP) is unanimously acknowledged as the “blue gold” in the urgent quest for new drugs. Consequently, a significant increase in the discovery of MNP published in the literature has been observed in the past decades, particularly from marine invertebrates. However, it remains unclear whether target metabolites originate from the marine invertebrates themselves or from their microbial symbionts. This issue underlines critical challenges associated with the lack of biomass required to supply the early stages of the drug discovery pipeline. The present review discusses potential solutions for such challenges, with particular emphasis on innovative approaches to culture invertebrate holobionts (microorganism-invertebrate assemblages) through in toto aquaculture, together with methods for the discovery and initial production of bioactive compounds from these microbial symbionts. PMID:24983638

Metatranscriptome of an Anaerobic Benzene-Degrading, Nitrate-Reducing Enrichment Culture Reveals Involvement of Carboxylation in Benzene Ring Activation

PubMed Central

Luo, Fei; Gitiafroz, Roya; Devine, Cheryl E.; Gong, Yunchen; Hug, Laura A.; Raskin, Lutgarde

2014-01-01

The enzymes involved in the initial steps of anaerobic benzene catabolism are not known. To try to elucidate this critical step, a metatranscriptomic analysis was conducted to compare the genes transcribed during the metabolism of benzene and benzoate by an anaerobic benzene-degrading, nitrate-reducing enrichment culture. RNA was extracted from the mixed culture and sequenced without prior mRNA enrichment, allowing simultaneous examination of the active community composition and the differential gene expression between the two treatments. Ribosomal and mRNA sequences attributed to a member of the family Peptococcaceae from the order Clostridiales were essentially only detected in the benzene-amended culture samples, implicating this group in the initial catabolism of benzene. Genes similar to each of two subunits of a proposed benzene-carboxylating enzyme were transcribed when the culture was amended with benzene. Anaerobic benzoate degradation genes from strict anaerobes were transcribed only when the culture was amended with benzene. Genes for other benzoate catabolic enzymes and for nitrate respiration were transcribed in both samples, with those attributed to an Azoarcus species being most abundant. These findings indicate that the mineralization of benzene starts with its activation by a strict anaerobe belonging to the Peptococcaceae, involving a carboxylation step to form benzoate. These data confirm the previously hypothesized syntrophic association between a benzene-degrading Peptococcaceae strain and a benzoate-degrading denitrifying Azoarcus strain for the complete catabolism of benzene with nitrate as the terminal electron acceptor. PMID:24795366

Initiation of movement from quiet stance: comparison of gait and stepping in elderly subjects of different levels of functional ability.

PubMed

Brunt, Denis; Santos, Valeria; Kim, Hyeong Dong; Light, Kathye; Levy, Charles

2005-04-01

This study describes how elderly subjects initiate gait, and step from a position of quiet stance. Based on scores from selected standardized tests subjects were placed in either a high (HFL) or low functional level (LFL) group and were asked to initiate gait, step onto a 10 cm high, 1.22 m wide curb and step over a 10 cm high, 9 cm wide obstacle at a self paced speed. Stepping conditions affected the velocity of movement. It was clear that all subjects decreased initiation velocity for both curb and obstacle compared to gait initiation. Swing and stance limb acceleration ground reaction forces and EMG amplitude were modulated according to initiation velocity. Toe clearance was greater for obstacle than curb and gait initiation. Swing toe-off was significantly earlier and there was a trend for obstacle clearance to be greater for the HFL group. Those in the LFL group appear to be at a greater risk for falling due to the possible effect of slower rate of toe-off that could influence toe clearance over the obstacle.

KLF4 Nuclear Export Requires ERK Activation and Initiates Exit from Naive Pluripotency.

PubMed

Dhaliwal, Navroop K; Miri, Kamelia; Davidson, Scott; Tamim El Jarkass, Hala; Mitchell, Jennifer A

2018-04-10

Cooperative action of a transcription factor complex containing OCT4, SOX2, NANOG, and KLF4 maintains the naive pluripotent state; however, less is known about the mechanisms that disrupt this complex, initiating exit from pluripotency. We show that, as embryonic stem cells (ESCs) exit pluripotency, KLF4 protein is exported from the nucleus causing rapid decline in Nanog and Klf4 transcription; as a result, KLF4 is the first pluripotency transcription factor removed from transcription-associated complexes during differentiation. KLF4 nuclear export requires ERK activation, and phosphorylation of KLF4 by ERK initiates interaction of KLF4 with nuclear export factor XPO1, leading to KLF4 export. Mutation of the ERK phosphorylation site in KLF4 (S132) blocks KLF4 nuclear export, the decline in Nanog, Klf4, and Sox2 mRNA, and differentiation. These findings demonstrate that relocalization of KLF4 to the cytoplasm is a critical first step in exit from the naive pluripotent state and initiation of ESC differentiation. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Transcription closed and open complex dynamics studies reveal balance between genetic determinants and co-factors

NASA Astrophysics Data System (ADS)

Sala, Adrien; Shoaib, Muhammad; Anufrieva, Olga; Mutharasu, Gnanavel; Jahan Hoque, Rawnak; Yli-Harja, Olli; Kandhavelu, Meenakshisundaram

2015-05-01

In E. coli, promoter closed and open complexes are key steps in transcription initiation, where magnesium-dependent RNA polymerase catalyzes RNA synthesis. However, the exact mechanism of initiation remains to be fully elucidated. Here, using single mRNA detection and dual reporter studies, we show that increased intracellular magnesium concentration affects Plac initiation complex formation resulting in a highly dynamic process over the cell growth phases. Mg2+ regulates transcription transition, which modulates bimodality of mRNA distribution in the exponential phase. We reveal that Mg2+ regulates the size and frequency of the mRNA burst by changing the open complex duration. Moreover, increasing magnesium concentration leads to higher intrinsic and extrinsic noise in the exponential phase. RNAP-Mg2+ interaction simulation reveals critical movements creating a shorter contact distance between aspartic acid residues and Nucleotide Triphosphate residues and increasing electrostatic charges in the active site. Our findings provide unique biophysical insights into the balanced mechanism of genetic determinants and magnesium ion in transcription initiation regulation during cell growth.

How to perform a critically appraised topic: part 2, appraise, evaluate, generate, and recommend.

PubMed

Kelly, Aine Marie; Cronin, Paul

2011-11-01

This article continues the discussion of a critically appraised topic started in Part 1. A critically appraised topic is a practical tool for learning and applying critical appraisal skills. This article outlines steps 4-7 involved in performing a critically appraised topic for studies of diagnostic tests: Appraise, Appraise the literature; Evaluate, evaluate the strength of the evidence from the literature; Generate, generate graphs of conditional probability; and Recommend, draw conclusions and make recommendations. For steps 4-7 of performing a critically appraised topic, the main study results are summarized and translated into clinically useful measures of accuracy, efficacy, or risk.

Genome-wide Analysis Reveals Extensive Functional Interaction between DNA Replication Initiation and Transcription in the Genome of Trypanosoma brucei

PubMed Central

Tiengwe, Calvin; Marcello, Lucio; Farr, Helen; Dickens, Nicholas; Kelly, Steven; Swiderski, Michal; Vaughan, Diane; Gull, Keith; Barry, J. David; Bell, Stephen D.; McCulloch, Richard

2012-01-01

Summary Identification of replication initiation sites, termed origins, is a crucial step in understanding genome transmission in any organism. Transcription of the Trypanosoma brucei genome is highly unusual, with each chromosome comprising a few discrete transcription units. To understand how DNA replication occurs in the context of such organization, we have performed genome-wide mapping of the binding sites of the replication initiator ORC1/CDC6 and have identified replication origins, revealing that both localize to the boundaries of the transcription units. A remarkably small number of active origins is seen, whose spacing is greater than in any other eukaryote. We show that replication and transcription in T. brucei have a profound functional overlap, as reducing ORC1/CDC6 levels leads to genome-wide increases in mRNA levels arising from the boundaries of the transcription units. In addition, ORC1/CDC6 loss causes derepression of silent Variant Surface Glycoprotein genes, which are critical for host immune evasion. PMID:22840408

Free energy landscape for glucose condensation and dehydration reactions in dimethyl sulfoxide and the effects of solvent.

PubMed

Qian, Xianghong; Liu, Dajiang

2014-03-31

The mechanisms and free energy surfaces (FES) for the initial critical steps during proton-catalyzed glucose condensation and dehydration reactions were elucidated in dimethyl sulfoxide (DMSO) using Car-Parrinello molecular dynamics (CPMD) coupled with metadynamics (MTD) simulations. Glucose condensation reaction is initiated by protonation of C1--OH whereas dehydration reaction is initiated by protonation of C2--OH. The mechanisms in DMSO are similar to those in aqueous solution. The DMSO molecules closest to the C1--OH or C2--OH on glucose are directly involved in the reactions and act as proton acceptors during the process. However, the energy barriers are strongly solvent dependent. Moreover, polarization from the long-range electrostatic interaction affects the mechanisms and energetics of glucose reactions. Experimental measurements conducted in various DMSO/Water mixtures also show that energy barriers are solvent dependent in agreement with our theoretical results. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stakeholder Education for Community-Wide Health Initiatives: A Focus on Teen Pregnancy Prevention.

PubMed

Finley, Cara; Suellentrop, Katherine; Griesse, Rebecca; House, Lawrence Duane; Brittain, Anna

2018-01-01

Teen pregnancies and births continue to decline due in part to implementation of evidence-based interventions and clinical strategies. While local stakeholder education is also thought to be critical to this success, little is known about what types of strategies work best to engage stakeholders. With the goal of identifying and describing evidence-based or best practice strategies for stakeholder education in community-based public health initiatives, we conducted a systematic literature review of strategies used for effective stakeholder education. Over 400 articles were initially retrieved; 59 articles met inclusion criteria. Strategies were grouped into four steps that communities can use to support stakeholder education efforts: identify stakeholder needs and resources, develop a plan, develop tailored and compelling messaging, and use implementation strategies. These strategies lay a framework for high-quality stakeholder education. In future research, it is important to prioritize evaluating specific activities taken to raise awareness, educate, and engage a community in community-wide public health efforts.

DDX41 Recognizes RNA/DNA Retroviral Reverse Transcripts and Is Critical for In Vivo Control of Murine Leukemia Virus Infection.

PubMed

Stavrou, Spyridon; Aguilera, Alexya N; Blouch, Kristin; Ross, Susan R

2018-06-05

Host recognition of viral nucleic acids generated during infection leads to the activation of innate immune responses essential for early control of virus. Retrovirus reverse transcription creates numerous potential ligands for cytosolic host sensors that recognize foreign nucleic acids, including single-stranded RNA (ssRNA), RNA/DNA hybrids, and double-stranded DNA (dsDNA). We and others recently showed that the sensors cyclic GMP-AMP synthase (cGAS), DEAD-box helicase 41 (DDX41), and members of the Aim2-like receptor (ALR) family participate in the recognition of retroviral reverse transcripts. However, why multiple sensors might be required and their relative importance in in vivo control of retroviral infection are not known. Here, we show that DDX41 primarily senses the DNA/RNA hybrid generated at the first step of reverse transcription, while cGAS recognizes dsDNA generated at the next step. We also show that both DDX41 and cGAS are needed for the antiretroviral innate immune response to murine leukemia virus (MLV) and HIV in primary mouse macrophages and dendritic cells (DCs). Using mice with cell type-specific knockout of the Ddx41 gene, we show that DDX41 sensing in DCs but not macrophages was critical for controlling in vivo MLV infection. This suggests that DCs are essential in vivo targets for infection, as well as for initiating the antiviral response. Our work demonstrates that the innate immune response to retrovirus infection depends on multiple host nucleic acid sensors that recognize different reverse transcription intermediates. IMPORTANCE Viruses are detected by many different host sensors of nucleic acid, which in turn trigger innate immune responses, such as type I interferon (IFN) production, required to control infection. We show here that at least two sensors are needed to initiate a highly effective innate immune response to retroviruses-DDX41, which preferentially senses the RNA/DNA hybrid generated at the first step of retrovirus replication, and cGAS, which recognizes double-stranded DNA generated at the second step. Importantly, we demonstrate using mice lacking DDX41 or cGAS that both sensors are needed for the full antiviral response needed to control in vivo MLV infection. These findings underscore the need for multiple host factors to counteract retroviral infection. Copyright © 2018 Stavrou et al.

Clarification of vaccines: An overview of filter based technology trends and best practices.

PubMed

Besnard, Lise; Fabre, Virginie; Fettig, Michael; Gousseinov, Elina; Kawakami, Yasuhiro; Laroudie, Nicolas; Scanlan, Claire; Pattnaik, Priyabrata

2016-01-01

Vaccines are derived from a variety of sources including tissue extracts, bacterial cells, virus particles, recombinant mammalian, yeast and insect cell produced proteins and nucleic acids. The most common method of vaccine production is based on an initial fermentation process followed by purification. Production of vaccines is a complex process involving many different steps and processes. Selection of the appropriate purification method is critical to achieving desired purity of the final product. Clarification of vaccines is a critical step that strongly impacts product recovery and subsequent downstream purification. There are several technologies that can be applied for vaccine clarification. Selection of a harvesting method and equipment depends on the type of cells, product being harvested, and properties of the process fluids. These techniques include membrane filtration (microfiltration, tangential-flow filtration), centrifugation, and depth filtration (normal flow filtration). Historically vaccine harvest clarification was usually achieved by centrifugation followed by depth filtration. Recently membrane based technologies have gained prominence in vaccine clarification. The increasing use of single-use technologies in upstream processes necessitated a shift in harvest strategies. This review offers a comprehensive view on different membrane based technologies and their application in vaccine clarification, outlines the challenges involved and presents the current state of best practices in the clarification of vaccines. Copyright © 2015 Elsevier Inc. All rights reserved.

Transport calculation of neutrons leaked to the surroundings of the facilities by the JCO criticality accident in Tokai-mura.

PubMed

Imanaka, T

2001-09-01

A transport calculation of the neutrons leaked to the environment by the JCO criticality accident was carried out based on three-dimensional geometrical models of the buildings within the JCO territory. Our work started from an initial step to simulate the leakage process of neutrons from the precipitation tank, and proceeded to a step to calculate the neutron propagation throughout the JCO facilities. The total fission number during the accident in the precipitation tank was evaluated to be 2.5 x 10(18) by comparing the calculated neutron-induced activities per 235U fission with the measured values in a stainless-steel net sample taken 2 m from the precipitation tank. Shield effects by various structures within the JCO facilities were evaluated by comparing the present results with a previous calculation using two-dimensional models which suppose a point source of the fission spectrum in the air above the ground without any shield structures. The shield effect by the precipitation tank, itself, was obtained to be a factor of 3. The shield factor by the conversion building varied between 1.1 and 2, depending on the direction from the building. The shield effect by the surrounding buildings within the JCO territory was between I and 5, also depending on the direction.

Erosion characteristics and horizontal variability for small erosion depths in the Sacramento-San Joaquin River Delta, California, USA

NASA Astrophysics Data System (ADS)

Schoellhamer, David H.; Manning, Andrew J.; Work, Paul A.

2017-06-01

Erodibility of cohesive sediment in the Sacramento-San Joaquin River Delta (Delta) was investigated with an erosion microcosm. Erosion depths in the Delta and in the microcosm were estimated to be about one floc diameter over a range of shear stresses and times comparable to half of a typical tidal cycle. Using the conventional assumption of horizontally homogeneous bed sediment, data from 27 of 34 microcosm experiments indicate that the erosion rate coefficient increased as eroded mass increased, contrary to theory. We believe that small erosion depths, erosion rate coefficient deviation from theory, and visual observation of horizontally varying biota and texture at the sediment surface indicate that erosion cannot solely be a function of depth but must also vary horizontally. We test this hypothesis by developing a simple numerical model that includes horizontal heterogeneity, use it to develop an artificial time series of suspended-sediment concentration (SSC) in an erosion microcosm, then analyze that time series assuming horizontal homogeneity. A shear vane was used to estimate that the horizontal standard deviation of critical shear stress was about 30% of the mean value at a site in the Delta. The numerical model of the erosion microcosm included a normal distribution of initial critical shear stress, a linear increase in critical shear stress with eroded mass, an exponential decrease of erosion rate coefficient with eroded mass, and a stepped increase in applied shear stress. The maximum SSC for each step increased gradually, thus confounding identification of a single well-defined critical shear stress as encountered with the empirical data. Analysis of the artificial SSC time series with the assumption of a homogeneous bed reproduced the original profile of critical shear stress, but the erosion rate coefficient increased with eroded mass, similar to the empirical data. Thus, the numerical experiment confirms the small-depth erosion hypothesis. A linear model of critical shear stress and eroded mass is proposed to simulate small-depth erosion, assuming that the applied and critical shear stresses quickly reach equilibrium.

Erosion characteristics and horizontal variability for small erosion depths in the Sacramento-San Joaquin River Delta, California, USA

USGS Publications Warehouse

Schoellhamer, David H.; Manning, Andrew J.; Work, Paul A.

2017-01-01

Erodibility of cohesive sediment in the Sacramento-San Joaquin River Delta (Delta) was investigated with an erosion microcosm. Erosion depths in the Delta and in the microcosm were estimated to be about one floc diameter over a range of shear stresses and times comparable to half of a typical tidal cycle. Using the conventional assumption of horizontally homogeneous bed sediment, data from 27 of 34 microcosm experiments indicate that the erosion rate coefficient increased as eroded mass increased, contrary to theory. We believe that small erosion depths, erosion rate coefficient deviation from theory, and visual observation of horizontally varying biota and texture at the sediment surface indicate that erosion cannot solely be a function of depth but must also vary horizontally. We test this hypothesis by developing a simple numerical model that includes horizontal heterogeneity, use it to develop an artificial time series of suspended-sediment concentration (SSC) in an erosion microcosm, then analyze that time series assuming horizontal homogeneity. A shear vane was used to estimate that the horizontal standard deviation of critical shear stress was about 30% of the mean value at a site in the Delta. The numerical model of the erosion microcosm included a normal distribution of initial critical shear stress, a linear increase in critical shear stress with eroded mass, an exponential decrease of erosion rate coefficient with eroded mass, and a stepped increase in applied shear stress. The maximum SSC for each step increased gradually, thus confounding identification of a single well-defined critical shear stress as encountered with the empirical data. Analysis of the artificial SSC time series with the assumption of a homogeneous bed reproduced the original profile of critical shear stress, but the erosion rate coefficient increased with eroded mass, similar to the empirical data. Thus, the numerical experiment confirms the small-depth erosion hypothesis. A linear model of critical shear stress and eroded mass is proposed to simulate small-depth erosion, assuming that the applied and critical shear stresses quickly reach equilibrium.

Co-state initialization for the minimum-time low-thrust trajectory optimization

NASA Astrophysics Data System (ADS)

Taheri, Ehsan; Li, Nan I.; Kolmanovsky, Ilya

2017-05-01

This paper presents an approach for co-state initialization which is a critical step in solving minimum-time low-thrust trajectory optimization problems using indirect optimal control numerical methods. Indirect methods used in determining the optimal space trajectories typically result in two-point boundary-value problems and are solved by single- or multiple-shooting numerical methods. Accurate initialization of the co-state variables facilitates the numerical convergence of iterative boundary value problem solvers. In this paper, we propose a method which exploits the trajectory generated by the so-called pseudo-equinoctial and three-dimensional finite Fourier series shape-based methods to estimate the initial values of the co-states. The performance of the approach for two interplanetary rendezvous missions from Earth to Mars and from Earth to asteroid Dionysus is compared against three other approaches which, respectively, exploit random initialization of co-states, adjoint-control transformation and a standard genetic algorithm. The results indicate that by using our proposed approach the percent of the converged cases is higher for trajectories with higher number of revolutions while the computation time is lower. These features are advantageous for broad trajectory search in the preliminary phase of mission designs.

Minimally invasive convection-enhanced delivery of biologics into dorsal root ganglia: validation in the pig model and prospective modeling in humans. Technical note.

PubMed

Pleticha, Josef; Maus, Timothy P; Christner, Jodie A; Marsh, Michael P; Lee, Kendall H; Hooten, W Michael; Beutler, Andreas S

2014-10-01

Dorsal root ganglia (DRG) are critical anatomical structures involved in nociception. Intraganglionic (IG) drug delivery is therefore an important route of administration for novel analgesic therapies. Although IG injection in large animal models is highly desirable for preclinical biodistribution and toxicology studies of new drugs, no method to deliver pharmaceutical agents into the DRG has been reported in any large species. The present study describes a minimally invasive technique of IG agent delivery in domestic swine, one of the most common large animal models. The technique utilizes CT guidance for DRG targeting and a custom-made injection assembly for convection enhanced delivery (CED) of therapeutic agents directly into DRG parenchyma. The DRG were initially visualized by CT myelography to determine the optimal access route to the DRG. The subsequent IG injection consisted of 3 steps. First, a commercially available guide needle was advanced to a position dorsolateral to the DRG, and the dural root sleeve was punctured, leaving the guide needle contiguous with, but not penetrating, the DRG. Second, the custom-made stepped stylet was inserted through the guide needle into the DRG parenchyma. Third, the stepped stylet was replaced by the custom-made stepped needle, which was used for the IG CED. Initial dye injections performed in pig cadavers confirmed the accuracy of DRG targeting under CT guidance. Intraganglionic administration of adeno-associated virus in vivo resulted in a unilateral transduction of the injected DRG, with 33.5% DRG neurons transduced. Transgene expression was also found in the dorsal root entry zones at the corresponding spinal levels. The results thereby confirm the efficacy of CED by the stepped needle and a selectivity of DRG targeting. Imaging-based modeling of the procedure in humans suggests that IG CED may be translatable to the clinical setting.

Critical motor number for fractional steps of cytoskeletal filaments in gliding assays.

PubMed

Li, Xin; Lipowsky, Reinhard; Kierfeld, Jan

2012-01-01

In gliding assays, filaments are pulled by molecular motors that are immobilized on a solid surface. By varying the motor density on the surface, one can control the number N of motors that pull simultaneously on a single filament. Here, such gliding assays are studied theoretically using brownian (or Langevin) dynamics simulations and taking the local force balance between motors and filaments as well as the force-dependent velocity of the motors into account. We focus on the filament stepping dynamics and investigate how single motor properties such as stalk elasticity and step size determine the presence or absence of fractional steps of the filaments. We show that each gliding assay can be characterized by a critical motor number, N(c). Because of thermal fluctuations, fractional filament steps are only detectable as long as N < N(c). The corresponding fractional filament step size is l/N where l is the step size of a single motor. We first apply our computational approach to microtubules pulled by kinesin-1 motors. For elastic motor stalks that behave as linear springs with a zero rest length, the critical motor number is found to be N(c) = 4, and the corresponding distributions of the filament step sizes are in good agreement with the available experimental data. In general, the critical motor number N(c) depends on the elastic stalk properties and is reduced to N(c) = 3 for linear springs with a nonzero rest length. Furthermore, N(c) is shown to depend quadratically on the motor step size l. Therefore, gliding assays consisting of actin filaments and myosin-V are predicted to exhibit fractional filament steps up to motor number N = 31. Finally, we show that fractional filament steps are also detectable for a fixed average motor number as determined by the surface density (or coverage) of the motors on the substrate surface.

Critical validation studies of neurofeedback.

PubMed

Gruzelier, John; Egner, Tobias

2005-01-01

The field of neurofeedback training has proceeded largely without validation. In this article the authors review studies directed at validating sensory motor rhythm, beta and alpha-theta protocols for improving attention, memory, and music performance in healthy participants. Importantly, benefits were demonstrable with cognitive and neurophysiologic measures that were predicted on the basis of regression models of learning to enhance sensory motor rhythm and beta activity. The first evidence of operant control over the alpha-theta ratio is provided, together with remarkable improvements in artistic aspects of music performance equivalent to two class grades in conservatory students. These are initial steps in providing a much needed scientific basis to neurofeedback.

A kinematic analysis of the rapid step test in balance-impaired and unimpaired older women.

PubMed

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2007-04-01

Little is known about the kinematic and kinetic determinants that might explain age and balance-impairment alterations in the results of volitional stepping performance tests. Maximal unipedal stance time (UST) was used to distinguish "balance-impaired" old (BI, UST<10s, N=15, mean age=76 years) from unimpaired old (O, UST>30s, N=12, mean age=71 years) before they and healthy young females (Y, UST>30s, N=13, mean age=23 years) performed the rapid step test (RST). The RST evaluates the time required to take volitional front, side, and back steps of at least 80% maximum step length in response to verbal commands. Kinematic and kinetic data were recorded during the RST. The results indicate that the initiation phase of the step was the major source of age- and balance impairment-related delays. The delays in BI were primarily caused by increased postural adjustments prior to step initiation, as measured by center-of-pressure (COP) path length (p<0.003). The Step landing phase showed similar, but non-significant, temporal trends. Step length and peak center-of-mass (COM) deceleration during the Step-Out landing decreased in O by 18% (p=0.0002) and 24% (p=0.001), respectively, and a further 12% (p=0.04) and 18% (p=0.08) in BI. We conclude that the delay in BI step initiation was due to the increase in their postural adjustments prior to step initiation.

Variability of Anticipatory Postural Adjustments During Gait Initiation in Individuals With Parkinson Disease.

PubMed

Lin, Cheng-Chieh; Creath, Robert A; Rogers, Mark W

2016-01-01

In people with Parkinson disease (PD), difficulties with initiating stepping may be related to impairments of anticipatory postural adjustments (APAs). Increased variability in step length and step time has been observed in gait initiation in individuals with PD. In this study, we investigated whether the ability to generate consistent APAs during gait initiation is compromised in these individuals. Fifteen subjects with PD and 8 healthy control subjects were instructed to take rapid forward steps after a verbal cue. The changes in vertical force and ankle marker position were recorded via force platforms and a 3-dimensional motion capture system, respectively. Means, standard deviations, and coefficients of variation of both timing and magnitude of vertical force, as well as stepping variables, were calculated. During the postural phase of gait initiation the interval was longer and the force modulation was smaller in subjects with PD. Both the variability of timing and force modulation were larger in subjects with PD. Individuals with PD also had a longer time to complete the first step, but no significant differences were found for the variability of step time, length, and speed between groups. The increased variability of APAs during gait initiation in subjects with PD could affect posture-locomotion coupling, and lead to start hesitation, and even falls. Future studies are needed to investigate the effect of rehabilitation interventions on the variability of APAs during gait initiation in individuals with PD.Video abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A119).

Co-evolving Physical and Biological Organization in Step-pool Channels: Experiments from a Restoration Reach on Wildcat Creek, California

NASA Astrophysics Data System (ADS)

Chin, A.; O'Dowd, A. P.; Mendez, P. K.; Velasco, K. Z.; Leventhal, R. D.; Storesund, R.; Laurencio, L. R.

2014-12-01

Step-pools are important features in fluvial systems. Through energy dissipation, step-pools provide stability in high-energy environments that otherwise may erode and degrade. Although research has focused on geomorphological aspects of step-pool channels, the ecological significance of step-pool streams is increasingly recognized. Step-pool streams often contain higher density and diversity of benthic macroinvertebrates and are critical habitats for organisms such as salmonids and tailed frogs. Step-pools are therefore increasingly used to restore eroding channels and improve ecological conditions. This paper addresses a restoration reach of Wildcat Creek in Berkeley, California that featured an installation of step-pools in 2012. The design framework recognized step-pool formation as a self-organizing process that produces a rhythmic morphology. After placing step particles at locations where step-pools are expected to form according to hydraulic theory, the self-organizing approach allowed fluvial processes to refine the rocks into adjusted sequences over time. In addition, a 30-meter "experimental" reach was created to explore the co-evolution of geomorphological and ecological characteristics. After constructing a plane bed channel, boulders and cobbles piled at the upstream end allowed natural flows to mobilize and sort them into step-pool sequences. Ground surveys and LiDAR recorded the development of step-pool sequences over several seasons. Concurrent sampling of benthic macroinvertebrates documented the formation of biological communities in conjunction with habitat. Biological sampling in an upstream reference reach provided a comparison with the restored reach over time. Results to date show an emergent step-pool channel with steps that segment the plane bed into initial step and pool habitats. Biological communities are beginning to form, showing more distinction among habitat types during some seasons, although they do not yet approach reference values at this stage of development. Research over longer timeframes is needed to reveal how biological and physical characteristics may co-organize toward an equilibrium landscape. Such integrated understanding will assist development of innovative restoration designs.

The effect of anatase TiO2 surface structure on the behavior of ethanol adsorption and its initial dissociation step: A DFT study

NASA Astrophysics Data System (ADS)

Zhang, Riguang; Liu, Zhixue; Ling, Lixia; Wang, Baojun

2015-10-01

The perfect and defective surfaces of anatase TiO2 including (1 0 1) and (0 0 1) surfaces have been chosen to probe into the effect of anatase TiO2 surface structure on the behavior of ethanol adsorption and initial dissociation step. Here, the results are obtained by density functional theory (DFT) calculation together with the periodic slab model. Our results show that the surface structure of anatase TiO2 can obviously affect the behavior of ethanol adsorption and the catalytic activity of its initial dissociation step; firstly, on the perfect and defective surfaces of anatase (1 0 1), ethanol dominantly exists in the form of molecule adsorption; however, ethanol is the dissociative adsorption on the hydroxylated anatase (0 0 1), and the coexistences of molecular and dissociation adsorption modes on the perfect anatase (0 0 1). On the other hand, the initial dissociation step of ethanol with molecule adsorption prefers to begin with its O-H bond cleavage leading to CH3CH2O and H species rather than the cleavage of its α-C-H, β-C-H, C-C and C-O bonds, namely, the preferable O-H bond cleavage for the initial dissociation step of ethanol is independent of the surface structure of anatase TiO2; however, the corresponding catalytic activity of ethanol initial dissociation step with the O-H bond cleavage on different anatase TiO2 surfaces is in the following order: hydroxylated (0 0 1) > perfect (0 0 1) > defective (1 0 1) > perfect (1 0 1), suggesting that the catalytic activity for the initial dissociation step of ethanol is sensitive to the surface structure of anatase TiO2, and the hydroxylated (0 0 1) is the most favorable surface. Among these surfaces, the most favorable product for the initial dissociation step of ethanol is CH3CH2O species.

Next Generation Wiring

NASA Technical Reports Server (NTRS)

Medelius, Petro; Jolley, Scott; Fitzpatrick, Lilliana; Vinje, Rubiela; Williams, Martha; Clayton, LaNetra; Roberson, Luke; Smith, Trent; Santiago-Maldonado, Edgardo

2007-01-01

Wiring is a major operational component on aerospace hardware that accounts for substantial weight and volumetric space. Over time wire insulation can age and fail, often leading to catastrophic events such as system failure or fire. The next generation of wiring must be reliable and sustainable over long periods of time. These features will be achieved by the development of a wire insulation capable of autonomous self-healing that mitigates failure before it reaches a catastrophic level. In order to develop a self-healing insulation material, three steps must occur. First, methods of bonding similar materials must be developed that are capable of being initiated autonomously. This process will lead to the development of a manual repair system for polyimide wire insulation. Second, ways to initiate these bonding methods that lead to materials that are similar to the primary insulation must be developed. Finally, steps one and two must be integrated to produce a material that has no residues from the process that degrades the insulating properties of the final repaired insulation. The self-healing technology, teamed with the ability to identify and locate damage, will greatly improve reliability and safety of electrical wiring of critical systems. This paper will address these topics, discuss the results of preliminary testing, and remaining development issues related to self-healing wire insulation.

Neutrophils suppress intraluminal NK-mediated tumor cell clearance and enhance extravasation of disseminated carcinoma cells

PubMed Central

Spiegel, Asaf; Brooks, Mary W.; Houshyar, Samin; Reinhardt, Ferenc; Ardolino, Michele; Fessler, Evelyn; Chen, Michelle B.; Krall, Jordan A.; DeCock, Jasmine; Zervantonakis, Ioannis K.; Iannello, Alexandre; Iwamoto, Yoshiko; Cortez-Retamozo, Virna; Kamm, Roger D.; Pittet, Mikael J.; Raulet, David H.; Weinberg, Robert A.

2016-01-01

Immune cells promote the initial metastatic dissemination of carcinoma cells from primary tumors. In contrast to their well-studied functions in the initial stages of metastasis, the specific roles of immunocytes in facilitating progression through the critical later steps of the invasion-metastasis cascade remain poorly understood. Here we define novel functions of neutrophils in promoting intraluminal survival and extravasation at sites of metastatic dissemination. We show that CD11b+/Ly6G+ neutrophils enhance metastasis formation via two distinct mechanisms. First, neutrophils inhibit natural killer cell function, which leads to a significant increase in the intraluminal survival time of tumor cells. Thereafter, neutrophils operate to facilitate extravasation of tumor cells through the secretion of IL-1β and matrix metalloproteinases. These results identify neutrophils as key regulators of intraluminal survival and extravasation through their crosstalk with host cells and disseminating carcinoma cells. PMID:27072748

Publication Guidelines for Quality Improvement Studies in Health Care: Evolution of the SQUIRE Project

PubMed Central

Batalden, Paul; Stevens, David; Ogrinc, Greg; Mooney, Susan

2008-01-01

In 2005 we published draft guidelines for reporting studies of quality improvement interventions as the initial step in a consensus process for development of a more definitive version. The current article contains the revised version, which we refer to as SQUIRE (Standards for QUality Improvement Reporting Excellence). We describe the consensus process, which included informal feedback, formal written commentaries, input from publication guideline developers, review of the literature on the epistemology of improvement and on methods for evaluating complex social programs, and a meeting of stakeholders for critical review of the guidelines’ content and wording, followed by commentary on sequential versions from an expert consultant group. Finally, we examine major differences between SQUIRE and the initial draft, and consider limitations of and unresolved questions about SQUIRE; we also describe ancillary supporting documents and alternative versions under development, and plans for dissemination, testing, and further development of SQUIRE. PMID:18830766

Critical Thinking Theory to Practice: Using the Expert's Thought Process as Guide for Learning and Assessment.

PubMed

Marshall, Teresa A; Marchini, Leonardo; Cowen, Howard; Hartshorn, Jennifer E; Holloway, Julie A; Straub-Morarend, Cheryl L; Gratton, David; Solow, Catherine M; Colangelo, Nicholas; Johnsen, David C

2017-08-01

Critical thinking skills are essential for the successful dentist, yet few explicit skillsets in critical thinking have been developed and published in peer-reviewed literature. The aims of this article are to 1) offer an assessable critical thinking teaching model with the expert's thought process as the outcome, learning guide, and assessment instrument and 2) offer three critical thinking skillsets following this model: for geriatric risk assessment, technology decision making, and situation analysis/reflections. For the objective component, the student demonstrates delivery of each step in the thought process. For the subjective component, the student is judged to have grasped the principles as applied to the patient or case. This article describes the framework and the results of pilot tests in which students in one year at this school used the model in the three areas, earning scores of 90% or above on the assessments. The model was thus judged to be successful for students to demonstrate critical thinking skillsets in the course settings. Students consistently delivered each step of the thought process and were nearly as consistent in grasping the principles behind each step. As more critical thinking skillsets are implemented, a reinforcing network develops.

Development of clinical process measures for pediatric burn care: Understanding variation in practice patterns.

PubMed

Kazis, Lewis E; Sheridan, Robert L; Shapiro, Gabriel D; Lee, Austin F; Liang, Matthew H; Ryan, Colleen M; Schneider, Jeffrey C; Lydon, Martha; Soley-Bori, Marina; Sonis, Lily A; Dore, Emily C; Palmieri, Tina; Herndon, David; Meyer, Walter; Warner, Petra; Kagan, Richard; Stoddard, Frederick J; Murphy, Michael; Tompkins, Ronald G

2018-04-01

There has been little systematic examination of variation in pediatric burn care clinical practices and its effect on outcomes. As a first step, current clinical care processes need to be operationally defined. The highly specialized burn care units of the Shriners Hospitals for Children system present an opportunity to describe the processes of care. The aim of this study was to develop a set of process-based measures for pediatric burn care and examine adherence to them by providers in a cohort of pediatric burn patients. We conducted a systematic literature review to compile a set of process-based indicators. These measures were refined by an expert panel of burn care providers, yielding 36 process-based indicators in four clinical areas: initial evaluation and resuscitation, acute excisional surgery and critical care, psychosocial and pain control, and reconstruction and aftercare. We assessed variability in adherence to the indicators in a cohort of 1,076 children with burns at four regional pediatric burn programs in the Shriners Hospital system. The percentages of the cohort at each of the four sites were as follows: Boston, 20.8%; Cincinnati, 21.1%; Galveston, 36.0%; and Sacramento, 22.1%. The cohort included children who received care between 2006 and 2010. Adherence to the process indicators varied both across sites and by clinical area. Adherence was lowest for the clinical areas of acute excisional surgery and critical care, with a range of 35% to 48% across sites, followed by initial evaluation and resuscitation (range, 34%-60%). In contrast, the clinical areas of psychosocial and pain control and reconstruction and aftercare had relatively high adherence across sites, with ranges of 62% to 93% and 71% to 87%, respectively. Of the 36 process indicators, 89% differed significantly in adherence between clinical sites (p < 0.05). Acute excisional surgery and critical care exhibited the most variability. The development of this set of process-based measures represents an important step in the assessment of clinical practice in pediatric burn care. Substantial variation was observed in practices of pediatric burn care. However, further research is needed to link these process-based measures to clinical outcomes. Therapeutic/care management, level IV.

Scaling behavior of Film growth mechanism

NASA Astrophysics Data System (ADS)

Yoon, Mina; Nyung, Lee Ho; Suo, Zhigang; Hong, Wei; Christen, Hans M.; Lowndes, Doug; Zhang, Zhenyu

2006-03-01

Experimental evidence has accumulated that a strained film can grow stably on a vicinal surface. Linear perturbation analysis of the step-flow regime results in a dispersion relation which determines the persistence of the step-flow growth. The dispersion relation can also be used to probe the system parameters. Investigating the growth dynamics in the step-bunching regime, we found that there is a critical film thickness above which step-bunching occurs. The critical thickness shows a scaling behavior depending on the terrace width and the deposition flux. Experiments show a qualitative agreement with the theory. Our results may open a way to grow films in a desired way.

Technical Steps to Support Nuclear Arsenal Downsizing: A Report by the APS Panel on Public Affairs

DTIC Science & Technology

2010-02-01

play a critical role in advancing the US plan to balance deter- rence with downsizing the US nuclear arsenal. In particular, S&T are essential to enable...nuclear-armed nations must be assured that they will continue to be able to meet those critical security needs. While individual nuclear-armed...steps are essential to progress towards the eventual elimination of nuclear arsenals. Science and technology (S&T) will play a critical role in

In Vitro Modeling of Mechanics in Cancer Metastasis

PubMed Central

2017-01-01

In addition to a multitude of genetic and biochemical alterations, abnormal morphological, structural, and mechanical changes in cells and their extracellular environment are key features of tumor invasion and metastasis. Furthermore, it is now evident that mechanical cues alongside biochemical signals contribute to critical steps of cancer initiation, progression, and spread. Despite its importance, it is very challenging to study mechanics of different steps of metastasis in the clinic or even in animal models. While considerable progress has been made in developing advanced in vitro models for studying genetic and biological aspects of cancer, less attention has been paid to models that can capture both biological and mechanical factors realistically. This is mainly due to lack of appropriate models and measurement tools. After introducing the central role of mechanics in cancer metastasis, we provide an outlook on the emergence of novel in vitro assays and their combination with advanced measurement technologies to probe and recapitulate mechanics in conditions more relevant to the metastatic disease. PMID:29457129

Function-oriented synthesis: biological evaluation of laulimalide analogues derived from a last step cross metathesis diversification strategy.

PubMed

Mooberry, Susan L; Hilinski, Michael K; Clark, Erin A; Wender, Paul A

2008-01-01

Laulimalide is a potent microtubule stabilizing agent and a promising anticancer therapeutic lead. The identification of stable, efficacious and accessible analogues is critical to clinically exploiting this novel lead. To determine which structural features of laulimalide are required for beneficial function and thus for accessing superior clinical candidates, a series of side chain analogues were prepared through a last step cross metathesis diversification strategy and their biological activities were evaluated. Five analogues, differing in potency from 233 nM to 7.9 muM, effectively inhibit cancer cell proliferation. Like laulimalide, they retain activity against multidrug resistant cells, stabilize microtubules and cause the formation of aberrant mitotic spindles, mitotic accumulation, Bcl-2 phosphorylation and initiation of apoptosis. Structural modifications in the C 23-C 27 dihydropyran side chain can be made without changing the overall mechanism of action, but it is clear that this subunit has more than a bystander role.

First steps of bacteriophage SPP1 entry into Bacillus subtilis.

PubMed

Jakutytė, Lina; Lurz, Rudi; Baptista, Catarina; Carballido-Lopez, Rut; São-José, Carlos; Tavares, Paulo; Daugelavičius, Rimantas

2012-01-20

The mechanism of genome transfer from the virion to the host cytoplasm is critical to understand and control the beginning of viral infection. The initial steps of bacteriophage SPP1 infection of the Gram-positive bacterium Bacillus subtilis were monitored by following changes in permeability of the cytoplasmic membrane (CM). SPP1 leads to a distinctively faster CM depolarization than the one caused by podovirus ϕ29 or myovirus SP01 during B. subtilis infection. Depolarization requires interaction of SPP1 infective virion to its receptor protein YueB. The amplitude of depolarization depends on phage input and concentration of YueB at the cell surface. Sub-millimolar concentrations of Ca(2+) are necessary and sufficient for SPP1 reversible binding to the host envelope and thus to trigger depolarization while DNA delivery to the cytoplasm depends on millimolar concentrations of this divalent cation. A model describing the early events of bacteriophage SPP1 infection is presented. Copyright © 2011 Elsevier Inc. All rights reserved.

PICK1 interacts with ABP/GRIP to regulate AMPA receptor trafficking.

PubMed

Lu, Wei; Ziff, Edward B

2005-08-04

PICK1 and ABP/GRIP bind to the AMPA receptor (AMPAR) GluR2 subunit C terminus. Transfer of the receptor from ABP/GRIP to PICK1, facilitated by GluR2 S880 phosphorylation, may initiate receptor trafficking. Here we report protein interactions that regulate these steps. The PICK1 BAR domain interacts intermolecularly with the ABP/GRIP linker II region and intramolecularly with the PICK1 PDZ domain. Binding of PKCalpha or GluR2 to the PICK1 PDZ domain disrupts the intramolecular interaction and facilitates the PICK1 BAR domain association with ABP/GRIP. Interference with the PICK1-ABP/GRIP interaction impairs S880 phosphorylation of GluR2 by PKC and decreases the constitutive surface expression of GluR2, the NMDA-induced endocytosis of GluR2, and recycling of internalized GluR2. We suggest that the PICK1 interaction with ABP/GRIP is a critical step in controlling GluR2 trafficking.

Unnatural substrates reveal the importance of 8-oxoguanine for in vivo mismatch repair by MutY

PubMed Central

Livingston, Alison L.; O’Shea, Valerie L.; Kim, Taewoo; Kool, Eric T.; David, Sheila S.

2009-01-01

Escherchia coli MutY plays an important role in preventing mutations associated with the oxidative lesion 7,8-dihydro-8-oxo-2′-deoxyguanosine (OG) in DNA by excising adenines from OG:A mismatches as the first step of base excision repair. To determine the importance of specific steps in the base pair recognition and base removal process of MutY, we have evaluated the effects of modifications of the OG:A substrate on the kinetics of base removal, mismatch affinity and repair to G:C in an Escherchia coli-based assay. Surprisingly, adenine modification was tolerated in the cellular assay, while modification of OG results in minimal cellular repair. High affinity for the mismatch and efficient base removal require the presence of OG. Taken together, these results suggest that the presence of OG is a critical feature for MutY to locate OG:A mismatches and select the appropriate adenines for excision to initiate repair in vivo prior to replication. PMID:18026095

Control of mediolateral stability during rapid step initiation with preferred and non-preferred leg: is it symmetrical?

PubMed

Yiou, E; Do, M C

2010-05-01

During voluntary stepping initiation, postural stability along the mediolateral direction is controlled via "anticipatory postural adjustment" (APA). This study tested the hypothesis that, in young healthy subjects, the biomechanical features of mediolateral APA depend on the leg that initiates stepping. Subjects (N=10) initiated a rapid single step with the preferred (P condition) and the non-preferred leg (NP condition) on a force-plate. Results showed that mediolateral APA duration (P=0.020) and amplitude were higher (as attested by the increase in maximal center-of-gravity velocity (P=0.003) and displacement (P<0.001) during APA), and that mediolateral stability was better (as attested by the attenuation in center-of-gravity velocity at time of swing-foot contact (P=0.007)) in P than in NP. These results support the view that stepping initiation in healthy subjects involves postural asymmetry. This statement may have relevant implications in clinical evaluation where postural asymmetry is generally considered as reflecting postural impairment. Copyright 2010 Elsevier B.V. All rights reserved.

Acoustic investigation of the aperture dynamics of an elastic membrane closing an overpressurized cylindrical cavity

NASA Astrophysics Data System (ADS)

Sánchez, Claudia; Vidal, Valérie; Melo, Francisco

2015-08-01

We report an experimental study of the acoustic signal produced by the rupture of an elastic membrane that initially closes a cylindrical overpressurized cavity. This configuration has been recently used as an experimental model system for the investigation of the acoustic emission from the bursting of elongated gas bubbles rising in a conduit. Here, we investigate the effect of the membrane rupture dynamics on the acoustic signal produced by the pressure release by changing the initial tension of the membrane. The initial overpressure in the cavity is fixed at a value such that the system remains in the linear acoustic regime. For large initial membrane deformation, the rupture time τ rup is small compared to the wave propagation time in the cavity and the pressure wave inside the conduit can be fully captured by the linear theory. For low membrane tension, a hole is pierced in the membrane but its rupture does not occur. For intermediate deformation, finally, the rupture progresses in two steps: first the membrane opens slowly; then, after reaching a critical size, the rupture accelerates. A transversal wave is excited along the membrane surface. The characteristic signature of each opening dynamics on the acoustic emission is described.

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

Gehin, Jess C; Godfrey, Andrew T; Evans, Thomas M

The Consortium for Advanced Simulation of Light Water Reactors (CASL) is developing a collection of methods and software products known as VERA, the Virtual Environment for Reactor Applications, including a core simulation capability called VERA-CS. A key milestone for this endeavor is to validate VERA against measurements from operating nuclear power reactors. The first step in validation against plant data is to determine the ability of VERA to accurately simulate the initial startup physics tests for Watts Bar Nuclear Power Station, Unit 1 (WBN1) cycle 1. VERA-CS calculations were performed with the Insilico code developed at ORNL using cross sectionmore » processing from the SCALE system and the transport capabilities within the Denovo transport code using the SPN method. The calculations were performed with ENDF/B-VII.0 cross sections in 252 groups (collapsed to 23 groups for the 3D transport solution). The key results of the comparison of calculations with measurements include initial criticality, control rod worth critical configurations, control rod worth, differential boron worth, and isothermal temperature reactivity coefficient (ITC). The VERA results for these parameters show good agreement with measurements, with the exception of the ITC, which requires additional investigation. Results are also compared to those obtained with Monte Carlo methods and a current industry core simulator.« less

Heterogeneous selenite reduction by zero valent iron steel wool.

PubMed

Li, Ziyan; Huang, Donglin; McDonald, Louis M

2017-02-01

Mine drainage from the low-sulfur surface coal mines in southern West Virginia, USA, is circumneutral (pH > 6) but contains elevated selenium (Se) concentrations. Removal of selenite ions from aqueous solutions under anoxic condition at pH 6-8.5 by zero valent iron steel wool (ZVI-SW) was investigated in bench-scale kinetic experiments using wet chemical, microscopic and spectroscopic techniques (X-ray photoelectron spectroscopy). ZVI-SW could effectively and efficiently remove Se IV from solution with pH 6-8.5. A two-step removal mechanism was identified for Se IV reduction by ZVI-SW. The proposed mechanism was electrochemical reduction of Se IV by Fe 0 in an initial lag stage, followed by a faster heterogeneous reduction, mediated by an Fe II -bearing phase (hydroxide or green rust). Solution pH was a critical factor for the kinetic rate in the lag stage (0.33 h -1 for pH > 8 and 0.10 h -1 for pH 6-8). The length of lag stage was 20-30 min as determined by the time for dissolved Fe II concentration to reach 0.30 ± 0.04 mg L -1 which was critical for induction of the faster stage. About 65% of the initial Se IV was reduced to Se 0 , the primary reductive product in both stages.

Improving quality of care for depression: the German Action Programme for the implementation of evidence-based guidelines.

PubMed

Härter, Martin; Bermejo, Isaac; Ollenschläger, Günter; Schneider, Frank; Gaebel, Wolfgang; Hegerl, Ulrich; Niebling, Wilhelm; Berger, Mathias

2006-04-01

Depressive disorders are of great medical and political significance. The potential inherent in achieving better guideline orientation and a better collaboration between different types of care is clear. Throughout the 1990s, educational initiatives were started for implementing guidelines. Evidence-based guidelines on depression have been formulated in many countries. This article presents an action programme for structural, educational, and research-related measures to implement evidence-based care of depressive disorders in the German health system. The starting points of the programme are the 'Guidelines Critical Appraisal Reports' of the 'Guideline Clearing House' and measures from the 'Competence Network on Depression and Suicidality' (CNDS) funded by the Federal Ministry of Education and Research. The article gives an overview of the steps achieved as recommended by the Guidelines Critical Appraisal Reports and the ongoing transfer process into the German health care system. The action programme shows that comprehensive interventions to develop and introduce evidence-based guidelines for depression can achieve benefits in the care of depression, e.g. in recognition, management, and clinical outcome. It was possible to implement the German Action Programme in selected care settings, and initial evaluation results suggest some improvements. The action programme provides preliminary work, materials, and results for developing a future 'Disease Management Programme' (DMP) for depression.

Taking Leadership in Initiating a Comprehensive US International Education Policy

ERIC Educational Resources Information Center

Lad, Kaetlyn

2008-01-01

A first step to ensuring that emerging school leaders possess the dispositions and skills necessary to be successful in a global community is for educational leaders to take initiative in moving toward a comprehensive Us International Education Policy. This article introduces possible steps to initiate such a policy.

The computation of all plane/surface intersections for CAD/CAM applications

NASA Technical Reports Server (NTRS)

Hoitsma, D. H., Jr.; Roche, M.

1984-01-01

The problem of the computation and display of all intersections of a given plane with a rational bicubic surface patch for use on an interactive CAD/CAM system is examined. The general problem of calculating all intersections of a plane and a surface consisting of rational bicubic patches is reduced to the case of a single generic patch by applying a rejection algorithm which excludes all patches that do not intersect the plane. For each pertinent patch the algorithm presented computed the intersection curves by locating an initial point on each curve, and computes successive points on the curve using a tolerance step equation. A single cubic equation solver is used to compute the initial curve points lying on the boundary of a surface patch, and the method of resultants as applied to curve theory is used to determine critical points which, in turn, are used to locate initial points that lie on intersection curves which are in the interior of the patch. Examples are given to illustrate the ability of this algorithm to produce all intersection curves.

Continuous track paths reveal additive evidence integration in multistep decision making.

PubMed

Buc Calderon, Cristian; Dewulf, Myrtille; Gevers, Wim; Verguts, Tom

2017-10-03

Multistep decision making pervades daily life, but its underlying mechanisms remain obscure. We distinguish four prominent models of multistep decision making, namely serial stage, hierarchical evidence integration, hierarchical leaky competing accumulation (HLCA), and probabilistic evidence integration (PEI). To empirically disentangle these models, we design a two-step reward-based decision paradigm and implement it in a reaching task experiment. In a first step, participants choose between two potential upcoming choices, each associated with two rewards. In a second step, participants choose between the two rewards selected in the first step. Strikingly, as predicted by the HLCA and PEI models, the first-step decision dynamics were initially biased toward the choice representing the highest sum/mean before being redirected toward the choice representing the maximal reward (i.e., initial dip). Only HLCA and PEI predicted this initial dip, suggesting that first-step decision dynamics depend on additive integration of competing second-step choices. Our data suggest that potential future outcomes are progressively unraveled during multistep decision making.

Ten steps to successful software process improvement

NASA Technical Reports Server (NTRS)

Kandt, R. K.

2003-01-01

This paper identifies ten steps for managing change that address organizational and cultural issues. Four of these steps are critical, that if not done, will almost guarantee failure. This ten-step program emphasizes the alignment of business goals, change process goals, and the work performed by the employees of an organization.

Powerlessness Reinterpreted: Reframing Step One.

ERIC Educational Resources Information Center

Young, Susan L.

The 12 steps of the well-known mutual help group, Alcoholics Anonymous (AA), begin with Step One, admitting powerlessness. Although Step One has helped many problem drinkers and other addicts, its spiritual concepts have been criticized. The possibility of reconceptualizing powerlessness as empowering, not only within AA and its offshoot programs,…

Do-It-Yourself Critical Path Method.

ERIC Educational Resources Information Center

Morris, Edward P., Jr.

This report describes the critical path method (CPM), a system for planning and scheduling work to get the best time-cost combination for any particular job. With the use of diagrams, the report describes how CPM works on a step-by-step basis. CPM uses a network to show which parts of a job must be done and how they would eventually fit together…

Deformable registration of the inflated and deflated lung in cone-beam CT-guided thoracic surgery: Initial investigation of a combined model- and image-driven approach

PubMed Central

Uneri, Ali; Nithiananthan, Sajendra; Schafer, Sebastian; Otake, Yoshito; Stayman, J. Webster; Kleinszig, Gerhard; Sussman, Marc S.; Prince, Jerry L.; Siewerdsen, Jeffrey H.

2013-01-01

Purpose: Surgical resection is the preferred modality for curative treatment of early stage lung cancer, but localization of small tumors (<10 mm diameter) during surgery presents a major challenge that is likely to increase as more early-stage disease is detected incidentally and in low-dose CT screening. To overcome the difficulty of manual localization (fingers inserted through intercostal ports) and the cost, logistics, and morbidity of preoperative tagging (coil or dye placement under CT-fluoroscopy), the authors propose the use of intraoperative cone-beam CT (CBCT) and deformable image registration to guide targeting of small tumors in video-assisted thoracic surgery (VATS). A novel algorithm is reported for registration of the lung from its inflated state (prior to pleural breach) to the deflated state (during resection) to localize surgical targets and adjacent critical anatomy. Methods: The registration approach geometrically resolves images of the inflated and deflated lung using a coarse model-driven stage followed by a finer image-driven stage. The model-driven stage uses image features derived from the lung surfaces and airways: triangular surface meshes are morphed to capture bulk motion; concurrently, the airways generate graph structures from which corresponding nodes are identified. Interpolation of the sparse motion fields computed from the bounding surface and interior airways provides a 3D motion field that coarsely registers the lung and initializes the subsequent image-driven stage. The image-driven stage employs an intensity-corrected, symmetric form of the Demons method. The algorithm was validated over 12 datasets, obtained from porcine specimen experiments emulating CBCT-guided VATS. Geometric accuracy was quantified in terms of target registration error (TRE) in anatomical targets throughout the lung, and normalized cross-correlation. Variations of the algorithm were investigated to study the behavior of the model- and image-driven stages by modifying individual algorithmic steps and examining the effect in comparison to the nominal process. Results: The combined model- and image-driven registration process demonstrated accuracy consistent with the requirements of minimally invasive VATS in both target localization (∼3–5 mm within the target wedge) and critical structure avoidance (∼1–2 mm). The model-driven stage initialized the registration to within a median TRE of 1.9 mm (95% confidence interval (CI) maximum = 5.0 mm), while the subsequent image-driven stage yielded higher accuracy localization with 0.6 mm median TRE (95% CI maximum = 4.1 mm). The variations assessing the individual algorithmic steps elucidated the role of each step and in some cases identified opportunities for further simplification and improvement in computational speed. Conclusions: The initial studies show the proposed registration method to successfully register CBCT images of the inflated and deflated lung. Accuracy appears sufficient to localize the target and adjacent critical anatomy within ∼1–2 mm and guide localization under conditions in which the target cannot be discerned directly in CBCT (e.g., subtle, nonsolid tumors). The ability to directly localize tumors in the operating room could provide a valuable addition to the VATS arsenal, obviate the cost, logistics, and morbidity of preoperative tagging, and improve patient safety. Future work includes in vivo testing, optimization of workflow, and integration with a CBCT image guidance system. PMID:23298134

Deformable registration of the inflated and deflated lung in cone-beam CT-guided thoracic surgery: initial investigation of a combined model- and image-driven approach.

PubMed

Uneri, Ali; Nithiananthan, Sajendra; Schafer, Sebastian; Otake, Yoshito; Stayman, J Webster; Kleinszig, Gerhard; Sussman, Marc S; Prince, Jerry L; Siewerdsen, Jeffrey H

2013-01-01

Surgical resection is the preferred modality for curative treatment of early stage lung cancer, but localization of small tumors (<10 mm diameter) during surgery presents a major challenge that is likely to increase as more early-stage disease is detected incidentally and in low-dose CT screening. To overcome the difficulty of manual localization (fingers inserted through intercostal ports) and the cost, logistics, and morbidity of preoperative tagging (coil or dye placement under CT-fluoroscopy), the authors propose the use of intraoperative cone-beam CT (CBCT) and deformable image registration to guide targeting of small tumors in video-assisted thoracic surgery (VATS). A novel algorithm is reported for registration of the lung from its inflated state (prior to pleural breach) to the deflated state (during resection) to localize surgical targets and adjacent critical anatomy. The registration approach geometrically resolves images of the inflated and deflated lung using a coarse model-driven stage followed by a finer image-driven stage. The model-driven stage uses image features derived from the lung surfaces and airways: triangular surface meshes are morphed to capture bulk motion; concurrently, the airways generate graph structures from which corresponding nodes are identified. Interpolation of the sparse motion fields computed from the bounding surface and interior airways provides a 3D motion field that coarsely registers the lung and initializes the subsequent image-driven stage. The image-driven stage employs an intensity-corrected, symmetric form of the Demons method. The algorithm was validated over 12 datasets, obtained from porcine specimen experiments emulating CBCT-guided VATS. Geometric accuracy was quantified in terms of target registration error (TRE) in anatomical targets throughout the lung, and normalized cross-correlation. Variations of the algorithm were investigated to study the behavior of the model- and image-driven stages by modifying individual algorithmic steps and examining the effect in comparison to the nominal process. The combined model- and image-driven registration process demonstrated accuracy consistent with the requirements of minimally invasive VATS in both target localization (∼3-5 mm within the target wedge) and critical structure avoidance (∼1-2 mm). The model-driven stage initialized the registration to within a median TRE of 1.9 mm (95% confidence interval (CI) maximum = 5.0 mm), while the subsequent image-driven stage yielded higher accuracy localization with 0.6 mm median TRE (95% CI maximum = 4.1 mm). The variations assessing the individual algorithmic steps elucidated the role of each step and in some cases identified opportunities for further simplification and improvement in computational speed. The initial studies show the proposed registration method to successfully register CBCT images of the inflated and deflated lung. Accuracy appears sufficient to localize the target and adjacent critical anatomy within ∼1-2 mm and guide localization under conditions in which the target cannot be discerned directly in CBCT (e.g., subtle, nonsolid tumors). The ability to directly localize tumors in the operating room could provide a valuable addition to the VATS arsenal, obviate the cost, logistics, and morbidity of preoperative tagging, and improve patient safety. Future work includes in vivo testing, optimization of workflow, and integration with a CBCT image guidance system.

Initiation precursors and initiators in laser-induced copolymerization of styrene and maleic anhydride in acetone

NASA Technical Reports Server (NTRS)

Miner, Gilda A.; Meador, Willard E.; Chang, C. Ken

1990-01-01

The initiation step of photopolymerized styrene/maleic anhydride copolymer was investigated at 365 nm. UV absorption measurements provide decisive evidence that the styrene/maleic anhydride charge transfer complex is the sole absorbing species; however, key laser experiments suggest intermediate reactions lead to a monoradical initiating species. A mechanism for the photoinitiation step of the copolymer is proposed.

A Survey of Usability Practices in Free/Libre/Open Source Software

NASA Astrophysics Data System (ADS)

Paul, Celeste Lyn

A review of case studies about usability in eight Free/Libre/Open Source Software (FLOSS) projects showed that an important issue regarding a usability initiative in the project was the lack of user research. User research is a key component in the user-centered design (UCD) process and a necessary step for creating usable products. Reasons why FLOSS projects suffered from a lack of user research included poor or unclear project leadership, cultural differences between developer and designers, and a lack of usability engineers. By identifying these critical issues, the FLOSS usability community can begin addressing problems in the efficacy of usability activities and work towards creating more usable FLOSS products.

[Differences in anticipatory postural adjustments between self-generated and triggered gait initiation in 20 healthy subjects].

PubMed

Delval, A; Krystkowiak, P; Blatt, J-L; Labyt, E; Destée, A; Derambure, P; Defebvre, L

2005-01-01

Preparation of upper-limb movements differs between self-paced and triggered conditions. This study analyzed the anticipatory postural adjustments (APAs) of gait initiation in normal subjects in 2 conditions: self-generated and triggered by a "beep" sound. We recorded kinematic, spatiotemporal parameters of the first two steps by means of video motion analysis (6 infrared cameras), and kinetic parameters (using a force platform and the optoelectronic system) in 20 normal subjects. Two conditions: 1) self-generated initiation; and 2) initiation triggered by a "beep" sound were studied to evaluate the APA phase, by recording kinetic data (duration of the APAs, trajectory of the center of pressure, speed and trajectory of the center of mass). Kinematic data (first and second step speed, length and duration) were also recorded. First step speed and length were increased in self-paced gait initiation compared to triggered gait initiation in controls. We found no difference between the 2 conditions in terms of second step kinematic data. It was caused by a significant difference between the 2 conditions for the temporal characteristics of anticipatory postural adjustments (APAs) in the initiation of the first step, which was longer when normal subjects performed self-generated gait initiation. The trajectory of center of pressure and center of mass remained the same in the 2 conditions. APAs of gait initiation process are delayed under self-paced condition, although they do not differ qualitatively between reaction time and self-paced condition. Neuphysiological support of self-generated movement could explain these differences.

Back off! The effect of emotion on backward step initiation.

PubMed

Bouman, Daniëlle; Stins, John F

2018-02-01

The distance regulation (DR) hypothesis states that actors are inclined to increase their distance from an unpleasant stimulus. The current study investigated the relation between emotion and its effect on the control of backward step initiation, which constitutes an avoidance-like behavior. Participants stepped backward on a force plate in response to neutral, high-arousing pleasant and high-arousing unpleasant visual emotional stimuli. Gait initiation parameters and the results of an exploratory analysis of postural sway were compared across the emotion categories using significance testing and Bayesian statistics. Evidence was found that gait initiation parameters were largely unaffected by emotional conditions. In contrast, the exploratory analysis of postural immobility showed a significant effect: highly arousing stimuli (pleasant and unpleasant) resulted in more postural sway immediately preceding gait initiation compared to neutral stimuli. This suggests that arousal, rather than valence, affects pre-step sway. These results contradict the DR hypothesis, since avoidance gait-initiation in response to unpleasant stimuli was no different compared to pleasant stimuli. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Aging effect on step adjustments and stability control in visually perturbed gait initiation.

PubMed

Sun, Ruopeng; Cui, Chuyi; Shea, John B

2017-10-01

Gait adaptability is essential for fall avoidance during locomotion. It requires the ability to rapidly inhibit original motor planning, select and execute alternative motor commands, while also maintaining the stability of locomotion. This study investigated the aging effect on gait adaptability and dynamic stability control during a visually perturbed gait initiation task. A novel approach was used such that the anticipatory postural adjustment (APA) during gait initiation were used to trigger the unpredictable relocation of a foot-size stepping target. Participants (10 young adults and 10 older adults) completed visually perturbed gait initiation in three adjustment timing conditions (early, intermediate, late; all extracted from the stereotypical APA pattern) and two adjustment direction conditions (medial, lateral). Stepping accuracy, foot rotation at landing, and Margin of Dynamic Stability (MDS) were analyzed and compared across test conditions and groups using a linear mixed model. Stepping accuracy decreased as a function of adjustment timing as well as stepping direction, with older subjects exhibited a significantly greater undershoot in foot placement to late lateral stepping. Late adjustment also elicited a reaching-like movement (i.e. foot rotation prior to landing in order to step on the target), regardless of stepping direction. MDS measures in the medial-lateral and anterior-posterior direction revealed both young and older adults exhibited reduced stability in the adjustment step and subsequent steps. However, young adults returned to stable gait faster than older adults. These findings could be useful for future study of screening deficits in gait adaptability and preventing falls. Copyright © 2017 Elsevier B.V. All rights reserved.

Single-round selection yields a unique retroviral envelope utilizing GPR172A as its host receptor.

PubMed

Mazari, Peter M; Linder-Basso, Daniela; Sarangi, Anindita; Chang, Yehchung; Roth, Monica J

2009-04-07

The recognition by a viral envelope of its cognate host-cell receptor is the initial critical step in defining the viral host-range and tissue specificity. This study combines a single-round of selection of a random envelope library with a parallel cDNA screen for receptor function to identify a distinct retroviral envelope/receptor pair. The 11-aa targeting domain of the modified feline leukemia virus envelope consists of a constrained peptide. Critical to the binding of the constrained peptide envelope to its cellular receptor are a pair of internal cysteines and an essential Trp required for maintenance of titers >10(5) lacZ staining units per milliliter. The receptor used for viral entry is the human GPR172A protein, a G-protein-coupled receptor isolated from osteosarcoma cells. The ability to generate unique envelopes capable of using tissue- or disease-specific receptors marks an advance in the development of efficient gene-therapy vectors.

An African theory of bioethics: reply to MacPherson and Macklin.

PubMed

Metz, Thaddeus

2010-12-01

In a prior issue of Developing World Bioethics, Cheryl Macpherson and Ruth Macklin critically engaged with an article of mine, where I articulated a moral theory grounded on indigenous values salient in the sub-Saharan region, and then applied it to four major issues in bioethics, comparing and contrasting its implications with those of the dominant Western moral theories, utilitarianism and Kantianism. In response to my essay, Macpherson and Macklin have posed questions about: whether philosophical justifications are something with which bioethicists ought to be concerned; why something counts as 'African'; how medicine is a moral enterprise; whether an individual right to informed consent is consistent with sub-Saharan values; and when thought experiments help to establish firm conclusions about moral status. These are important issues for the field, and I use this reply to take discussion of them a step or two farther, defending my initial article from Macpherson's and Macklin's critical questions and objections. © 2010 Blackwell Publishing Ltd.

The KIM-family protein-tyrosine phosphatases use distinct reversible oxidation intermediates: Intramolecular or intermolecular disulfide bond formation.

PubMed

Machado, Luciana E S F; Shen, Tun-Li; Page, Rebecca; Peti, Wolfgang

2017-05-26

The kinase interaction motif (KIM) family of protein-tyrosine phosphatases (PTPs) includes hematopoietic protein-tyrosine phosphatase (HePTP), striatal-enriched protein-tyrosine phosphatase (STEP), and protein-tyrosine phosphatase receptor type R (PTPRR). KIM-PTPs bind and dephosphorylate mitogen-activated protein kinases (MAPKs) and thereby critically modulate cell proliferation and differentiation. PTP activity can readily be diminished by reactive oxygen species (ROS), e.g. H 2 O 2 , which oxidize the catalytically indispensable active-site cysteine. This initial oxidation generates an unstable sulfenic acid intermediate that is quickly converted into either a sulfinic/sulfonic acid (catalytically dead and irreversible inactivation) or a stable sulfenamide or disulfide bond intermediate (reversible inactivation). Critically, our understanding of ROS-mediated PTP oxidation is not yet sufficient to predict the molecular responses of PTPs to oxidative stress. However, identifying distinct responses will enable novel routes for PTP-selective drug design, important for managing diseases such as cancer and Alzheimer's disease. Therefore, we performed a detailed biochemical and molecular study of all KIM-PTP family members to determine their H 2 O 2 oxidation profiles and identify their reversible inactivation mechanism(s). We show that despite having nearly identical 3D structures and sequences, each KIM-PTP family member has a unique oxidation profile. Furthermore, we also show that whereas STEP and PTPRR stabilize their reversibly oxidized state by forming an intramolecular disulfide bond, HePTP uses an unexpected mechanism, namely, formation of a reversible intermolecular disulfide bond. In summary, despite being closely related, KIM-PTPs significantly differ in oxidation profiles. These findings highlight that oxidation protection is critical when analyzing PTPs, for example, in drug screening. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

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

Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu; Botas, Pablo; Faculty of Physics, Ruprecht-Karls-Universität Heidelberg, Heidelberg

Purpose: We describe a treatment plan optimization method for intensity modulated proton therapy (IMPT) that avoids high values of linear energy transfer (LET) in critical structures located within or near the target volume while limiting degradation of the best possible physical dose distribution. Methods and Materials: To allow fast optimization based on dose and LET, a GPU-based Monte Carlo code was extended to provide dose-averaged LET in addition to dose for all pencil beams. After optimizing an initial IMPT plan based on physical dose, a prioritized optimization scheme is used to modify the LET distribution while constraining the physical dosemore » objectives to values close to the initial plan. The LET optimization step is performed based on objective functions evaluated for the product of LET and physical dose (LET×D). To first approximation, LET×D represents a measure of the additional biological dose that is caused by high LET. Results: The method is effective for treatments where serial critical structures with maximum dose constraints are located within or near the target. We report on 5 patients with intracranial tumors (high-grade meningiomas, base-of-skull chordomas, ependymomas) in whom the target volume overlaps with the brainstem and optic structures. In all cases, high LET×D in critical structures could be avoided while minimally compromising physical dose planning objectives. Conclusion: LET-based reoptimization of IMPT plans represents a pragmatic approach to bridge the gap between purely physical dose-based and relative biological effectiveness (RBE)-based planning. The method makes IMPT treatments safer by mitigating a potentially increased risk of side effects resulting from elevated RBE of proton beams near the end of range.« less

Eureka: Six Easy Steps to Research Success

ERIC Educational Resources Information Center

Hubel, Joy Alter

2005-01-01

Eureka is similar to the Big6(super TM) research skills by Michael Eisenberg and Bob Berkowitz, as both methods simplify the complex process of critical information gathering into six user-friendly steps. The six research steps to Eureka are presented.

The critical steps for successful research: The research proposal and scientific writing: (A report on the pre-conference workshop held in conjunction with the 64(th) annual conference of the Indian Pharmaceutical Congress-2012).

PubMed

Balakumar, Pitchai; Inamdar, Mohammed Naseeruddin; Jagadeesh, Gowraganahalli

2013-04-01

An interactive workshop on 'The Critical Steps for Successful Research: The Research Proposal and Scientific Writing' was conducted in conjunction with the 64(th) Annual Conference of the Indian Pharmaceutical Congress-2012 at Chennai, India. In essence, research is performed to enlighten our understanding of a contemporary issue relevant to the needs of society. To accomplish this, a researcher begins search for a novel topic based on purpose, creativity, critical thinking, and logic. This leads to the fundamental pieces of the research endeavor: Question, objective, hypothesis, experimental tools to test the hypothesis, methodology, and data analysis. When correctly performed, research should produce new knowledge. The four cornerstones of good research are the well-formulated protocol or proposal that is well executed, analyzed, discussed and concluded. This recent workshop educated researchers in the critical steps involved in the development of a scientific idea to its successful execution and eventual publication.

ANTICIPATORY POSTURAL ADJUSTMENTS PRIOR TO STEP INITIATION ARE HYPOMETRIC IN UNTREATED PARKINSON'S DISEASE: AN ACCELEROMETER-BASED APPROACH

PubMed Central

Mancini, Martina; Zampieri, Cris; Carlson-Kuhta, Patricia; Chiari, Lorenzo; Horak, Fay B.

2010-01-01

Background and purpose Anticipatory postural adjustments (APAs), prior to step initiation, are bradykinetic in advanced Parkinson's disease (PD) and may be one of the factors associated with ‘start hesitation’. However, little is known about APAs in the early stage of PD. In this study, we determined whether body-worn accelerometers could be used to characterize step initiation deficits in subjects with early-to-moderate, untreated PD. Methods Eleven PD and 12 healthy control subjects were asked to take two steps. Postural adjustments were compared from center of pressure (COP) and from acceleration of the trunk at the center of mass level (L5). Results Our findings show that APAs measured from the peak COP displacement towards the swing leg and the peak trunk acceleration towards the stance leg were smaller in untreated PD compared to control subjects. The magnitude of APAs measured from peak COP displacements and accelerations were correlated. Conclusion These results suggest that quantitative analysis of step initiation from one accelerometer on the trunk could provide useful information for the characterization of patients in early stages of PD, when clinical evidence of start hesitation may not be detectable. Ambulatory monitoring of step initiation is also promising for monitoring patient progression in the home environment, and eventually providing feedback for preventing freezing of gait episodes. PMID:19473350

Controls on the breach geometry and flood hydrograph during overtopping of non-cohesive earthen dams

USGS Publications Warehouse

Walder, Joseph S.; Iverson, Richard M.; Godt, Jonathan W.; Logan, Matthew; Solovitz, Stephen A.

2015-01-01

Overtopping failure of non-cohesive earthen dams was investigated in 13 large-scale experiments with dams built of compacted, damp, fine-grained sand. Breaching was initiated by cutting a notch across the dam crest and allowing water escaping from a finite upstream reservoir to form its own channel. The channel developed a stepped profile, and upstream migration of the steps, which coalesced into a headcut, led to the establishment of hydraulic control (critical flow) at the channel head, or breach crest, an arcuate erosional feature that functions hydraulically as a weir. Novel photogrammetric methods, along with underwater videography, revealed that the retreating headcut maintained a slope near the angle of friction of the sand, while the cross section at the breach crest maintained a geometrically similar shape through time. That cross-sectional shape was nearly unaffected by slope failures, contrary to the assumption in many models of dam breaching. Flood hydrographs were quite reproducible--for sets of dams ranging in height from 0.55 m to 0.98 m--when the time datum was chosen as the time that the migrating headcut intersected the breach crest. Peak discharge increased almost linearly as a function of initial dam height. Early-time variability between flood hydrographs for nominally identical dams is probably a reflection of subtle experiment-to-experiment differences in groundwater hydrology and the interaction between surface water and groundwater.

MPA in Labor: Securing the Pearl Cays of Nicaragua

NASA Astrophysics Data System (ADS)

Gonzalez, Clarence; Jentoft, Svein

2011-04-01

Implementation of Marine Protected Areas (MPAs) has always a step-zero, i.e., an initial phase when the idea is incepted, communicated and negotiated among stakeholders. What happens during this phase is likely to have an impact later on. If not done right, the management of the MPA may encounter problems at later stage that will be difficult to correct. Inspired by this working theory, this article describes the effort to establish the Pearl Cays off the Caribbean coast of Nicaragua as a protected area. This case-study illustrates the critical actions to be taken during step-zero, i.e., what needs to be considered and done before an MPA is formally declared. The area investigated consists of a number of small islands (cays) and coral reefs, fishing grounds and marine turtle nesting areas. Throughout history, the cays have played an important role in sustaining livelihoods of nearby communities. Although the idea of an MPA was originally conservation, the communities saw it as an opportunity to regain ownership and control of the cays. By Nicaraguan law, in order to establish protected areas, consultation and approval from local people is required. In the case of the Pearl Cays, this has proved difficult. The article demonstrates how MPA initiatives must sometimes relate to already ongoing complex social processes in the area where they are to be instigated.

MPA in labor: securing the Pearl Cays of Nicaragua.

PubMed

Gonzalez, Clarence; Jentoft, Svein

2011-04-01

Implementation of Marine Protected Areas (MPAs) has always a step-zero, i.e., an initial phase when the idea is incepted, communicated and negotiated among stakeholders. What happens during this phase is likely to have an impact later on. If not done right, the management of the MPA may encounter problems at later stage that will be difficult to correct. Inspired by this working theory, this article describes the effort to establish the Pearl Cays off the Caribbean coast of Nicaragua as a protected area. This case-study illustrates the critical actions to be taken during step-zero, i.e., what needs to be considered and done before an MPA is formally declared. The area investigated consists of a number of small islands (cays) and coral reefs, fishing grounds and marine turtle nesting areas. Throughout history, the cays have played an important role in sustaining livelihoods of nearby communities. Although the idea of an MPA was originally conservation, the communities saw it as an opportunity to regain ownership and control of the cays. By Nicaraguan law, in order to establish protected areas, consultation and approval from local people is required. In the case of the Pearl Cays, this has proved difficult. The article demonstrates how MPA initiatives must sometimes relate to already ongoing complex social processes in the area where they are to be instigated.

Proton pump inhibitor step-down therapy for GERD: A multi-center study in Japan

PubMed Central

Tsuzuki, Takao; Okada, Hiroyuki; Kawahara, Yoshiro; Takenaka, Ryuta; Nasu, Junichiro; Ishioka, Hidehiko; Fujiwara, Akiko; Yoshinaga, Fumiya; Yamamoto, Kazuhide

2011-01-01

AIM: To investigate the predictors of success in step-down of proton pump inhibitor and to assess the quality of life (QOL). METHODS: Patients who had heartburn twice a week or more were treated with 20 mg omeprazole (OPZ) once daily for 8 wk as an initial therapy (study 1). Patients whose heartburn decreased to once a week or less at the end of the initial therapy were enrolled in study 2 and treated with 10 mg OPZ as maintenance therapy for an additional 6 mo (study 2). QOL was investigated using the gastrointestinal symptom rating scale (GSRS) before initial therapy, after both 4 and 8 wk of initial therapy, and at 1, 2, 3, and 6 mo after starting maintenance therapy. RESULTS: In study 1, 108 patients were analyzed. Their characteristics were as follows; median age: 63 (range: 20-88) years, sex: 46 women and 62 men. The success rate of the initial therapy was 76%. In the patients with successful initial therapy, abdominal pain, indigestion and reflux GSRS scores were improved. In study 2, 83 patients were analyzed. Seventy of 83 patients completed the study 2 protocol. In the per-protocol analysis, 80% of 70 patients were successful for step-down. On multivariate analysis of baseline demographic data and clinical information, no previous treatment for gastroesophageal reflux disease (GERD) [odds ratio (OR) 0.255, 95% CI: 0.06-0.98] and a lower indigestion score in GSRS at the beginning of step-down therapy (OR 0.214, 95% CI: 0.06-0.73) were found to be the predictors of successful step-down therapy. The improved GSRS scores by initial therapy were maintained through the step-down therapy. CONCLUSION: OPZ was effective for most GERD patients. However, those who have had previous treatment for GERD and experience dyspepsia before step-down require particular monitoring for relapse. PMID:21472108

Does a microprocessor-controlled prosthetic knee affect stair ascent strategies in persons with transfemoral amputation?

PubMed

Aldridge Whitehead, Jennifer M; Wolf, Erik J; Scoville, Charles R; Wilken, Jason M

2014-10-01

Stair ascent can be difficult for individuals with transfemoral amputation because of the loss of knee function. Most individuals with transfemoral amputation use either a step-to-step (nonreciprocal, advancing one stair at a time) or skip-step strategy (nonreciprocal, advancing two stairs at a time), rather than a step-over-step (reciprocal) strategy, because step-to-step and skip-step allow the leading intact limb to do the majority of work. A new microprocessor-controlled knee (Ottobock X2(®)) uses flexion/extension resistance to allow step-over-step stair ascent. We compared self-selected stair ascent strategies between conventional and X2(®) prosthetic knees, examined between-limb differences, and differentiated stair ascent mechanics between X2(®) users and individuals without amputation. We also determined which factors are associated with differences in knee position during initial contact and swing within X2(®) users. Fourteen individuals with transfemoral amputation participated in stair ascent sessions while using conventional and X2(®) knees. Ten individuals without amputation also completed a stair ascent session. Lower-extremity stair ascent joint angles, moment, and powers and ground reaction forces were calculated using inverse dynamics during self-selected strategy and cadence and controlled cadence using a step-over-step strategy. One individual with amputation self-selected a step-over-step strategy while using a conventional knee, while 10 individuals self-selected a step-over-step strategy while using X2(®) knees. Individuals with amputation used greater prosthetic knee flexion during initial contact (32.5°, p = 0.003) and swing (68.2°, p = 0.001) with higher intersubject variability while using X2(®) knees compared to conventional knees (initial contact: 1.6°, swing: 6.2°). The increased prosthetic knee flexion while using X2(®) knees normalized knee kinematics to individuals without amputation during swing (88.4°, p = 0.179) but not during initial contact (65.7°, p = 0.002). Prosthetic knee flexion during initial contact and swing were positively correlated with prosthetic limb hip power during pull-up (r = 0.641, p = 0.046) and push-up/early swing (r = 0.993, p < 0.001), respectively. Participants with transfemoral amputation were more likely to self-select a step-over-step strategy similar to individuals without amputation while using X2(®) knees than conventional prostheses. Additionally, the increased prosthetic knee flexion used with X2(®) knees placed large power demands on the hip during pull-up and push-up/early swing. A modified strategy that uses less knee flexion can be used to allow step-over-step ascent in individuals with less hip strength.

Vitamins C and E improve regrowth and reduce lipid peroxidation of blackberry shoot tips following cryopreservation.

PubMed

Uchendu, Esther E; Leonard, Scott W; Traber, Maret G; Reed, Barbara M

2010-01-01

Oxidative processes involved in cryopreservation protocols may be responsible for the reduced viability of tissues after liquid nitrogen exposure. Antioxidants that counteract these reactions should improve recovery. This study focused on oxidative lipid injury and the effects of exogenous vitamin E (tocopherol, Vit E) and vitamin C (ascorbic acid, Vit C) treatments on regrowth at four critical steps of the plant vitrification solution number 2 (PVS2) vitrification cryopreservation technique; pretreatment, loading, rinsing, and regrowth. Initial experiments showed that Vit E at 11-15 mM significantly increased regrowth (P < 0.001) when added at any of the four steps. There was significantly more malondialdehyde (MDA), a lipid peroxidation product, at each of the steps than in fresh untreated shoot tips. Vit E uptake was assayed at each step and showed significantly more alpha- and gamma-tocopherols in treated shoots than those without Vit E. Vit E added at each step significantly reduced MDA formation and improved shoot regrowth. Vit C (0.14-0.58 mM) also significantly improved regrowth of shoot tips at each step compared to the controls. Regrowth medium with high iron concentrations and Vit C decreased recovery. However, in iron-free medium, Vit C significantly improved recovery. Treatments with Vit E (11 mM) and Vit C (0.14 mM) combined were not significantly better than Vit C alone. We recommend adding Vit C (0.28 mM) to the pretreatment medium, the loading solution or the rinse solution in the PVS2 vitrification protocol. This is the first report of the application of vitamins for improving cryopreservation of plant tissues by minimizing oxidative damage.

Granular gel support-enabled extrusion of three-dimensional alginate and cellular structures.

PubMed

Jin, Yifei; Compaan, Ashley; Bhattacharjee, Tapomoy; Huang, Yong

2016-06-03

Freeform fabrication of soft structures has been of great interest in recent years. In particular, it is viewed as a critical step toward the grand vision of organ printing--the on-demand design and fabrication of three-dimensional (3D) human organ constructs for implantation and regenerative medicine. The objective of this study is to develop a novel granular gel support material-enabled, two-step gelation-based 'printing-then-gelation' approach to fabricate 3D alginate structures using filament extrusion. Specifically, a granular Carbopol microgel bath holds the ungelled alginate structure being extruded, avoiding the instantaneous gelation of each printed layer as well as resultant surface tension-induced nozzle clogging. Since Carbopol microgels react with multivalent cations, which are needed for alginate crosslinking, gelatin is introduced as a sacrificial material to make an alginate and gelatin bioink for extrusion, which gels thermally (step-one gelation) to initially stabilize the printed structure for removal from Carbopol. Then gelatin is melted and diffused away while alginate is ionically crosslinked in a 37 °C calcium chloride bath (step-two gelation), resulting in an alginate structure. The proposed 'printing-then-gelation' approach works for alginate structure fabrication, and it is also applicable for the printing of cellular constructs and other similar homogeneous soft structures using a two-step or even multi-step approach. The main conclusions are: (1) 0.8% (w/v) Carbopol bath with a neutral pH value may be most suitable for soft structure printing; (2) it is most effective to use a 0.9% (w/v) NaCl solution to facilitate the removal of residual Carbopol; and (3) alginate structures fabricated using the proposed approach demonstrate better mechanical properties than those fabricated using the conventional 'gelation-while-printing' approach.

Three-step cylindrical seal for high-performance turbomachines

NASA Technical Reports Server (NTRS)

Hendricks, Robert C.

1987-01-01

A three-step cylindrical seal configuration representing the seal for a high performance turbopump (e.g., the space shuttle main engine fuel pump) was tested under static (nonrotating) conditions. The test data included critical mass flux and pressure profiles over a wide range of inlet temperatures and pressures for fluid nitrogen and fluid hydrogen with the seal in concentric and fully eccentric positions. The critical mass flux (leakage rate) was 70% that of an equivalent straight cylindrical seal with a correspondingly higher pressure drop based on the same flow areas of 0.3569 sq cm but 85% that of the straight seal based on the third-step flow area of 0.3044 sq cm. The mass flow rates for the three step cylindrical seal in the fully eccentric and concentric positions were essentially the same, and the trends in flow coefficient followed those of a simple axisymmetric inlet configuration. However, for inlet stagnation temperatures less than the thermodynamic critical temperature the pressure profiles exhibited a flat region throughout the third step of the seal, with the pressure magnitude dependent on the inlet stagnation temperature. Such profiles represent an extreme positive direct stiffness. These conditions engendered a crossover in the pressure profile upstream of the postulated choke that resulted in a local negative stiffness. Flat and crossover profiles resulting from choking within the seal are practically unknown to the seal designer. However, they are of critical importance to turbomachine stability and must be integrated into any dynamic analysis of a seal of this configuration. In addition, choking is highly dependent on geometry, inlet-to-backpressure ratio, and inlet temperature and can occur within the seal even though the backpressure is above the critical pressure.

Development of a cross-disciplinary continuous insulin infusion protocol for non-critically ill patients in a French university hospital.

PubMed

Bernard, Lise; Roche, Béatrice; Batisse, Marie; Maqdasy, Salwan; Terral, Daniel; Sautou, Valérie; Tauveron, Igor

2016-10-01

In non-critically ill patients, the use of an insulin syringe pump allows the management of temporary situations during which other therapies cannot be used (failure of subcutaneous injections, awaiting advice from the diabetes team, emergency situations, prolonged corticosteroid therapy, initiation of an artificial nutrition, need for a fasting status, etc.). To manage the risks related to this «never event», the use of a standard validated protocol for insulin administration and monitoring is an essential prerequisite. To this end, a multidisciplinary approach is recommended. With the support of our subcommission «Endocrinology-Diabetology», we proceeded with a «step-by-step process» to create such a standardized protocol: (1) review of all existing protocols in our hospital; (2) overview of the literature data concerning insulin infusion protocols developed by multidisciplinary teams in France and abroad; (3) development of a standardized protocol for non-intensive care unit patients, respecting the current recommendations and adapting it to the working habits of health teams; and (4) validation of the protocol Two protocols based on the same structure but adapted to the health status of the patient have been developed. The protocols are divided in to three parts: (1) golden rules to make the use of the protocol appropriate and safe; (2) the algorithm (a double entry table) corresponding to a dynamic adaptation of insulin doses, clearly defining the target and the 'at risk situations'; and (3) practical aspects of the protocol: preparation of the syringe, treatment initiation and traceability. The protocols have been validated by the institution. Our standardized insulin infusion protocol is simple, easy to implement, safe and is likely to be applicable in diverse care units. However, the efficiency, safety and the workability of our protocols have to be clinically evaluated. © 2016 John Wiley & Sons, Ltd.

Analysis of the critical thinking process of junior high school students in solving geometric problems by utilizing the v-a-k learning styles model

NASA Astrophysics Data System (ADS)

Hananto, R. B.; Kusmayadi, T. A.; Riyadi

2018-05-01

The research aims to identify the critical thinking process of students in solving geometry problems. The geometry problem selected in this study was the building of flat side room (cube). The critical thinking process was implemented to visual, auditory and kinesthetic learning styles. This research was a descriptive analysis research using qualitative method. The subjects of this research were 3 students selected by purposive sampling consisting of visual, auditory, and kinesthetic learning styles. Data collection was done through test, interview, and observation. The results showed that the students' critical thinking process in identifying and defining steps for each learning style were similar in solving problems. The critical thinking differences were seen in enumerate, analyze, list, and self-correct steps. It was also found that critical thinking process of students with kinesthetic learning style was better than visual and auditory learning styles.

Examining racial and ethnic minority differences among YMSM during recruitment for an online HIV prevention intervention study.

PubMed

Du Bois, Steve N; Johnson, Sarah E; Mustanski, Brian

2012-08-01

HIV disproportionately affects racial and ethnic minority young men who have sex with men (YMSM). HIV prevention research does not include these YMSM commensurate to their HIV burden. We examined racial and ethnic differences during a unique three-step recruitment process for an online, YMSM HIV prevention intervention study (N = 660). Step one was completed in-person; steps two and three online. Fewer Black and Latino YMSM completed step two-initiating online participation-than White YMSM. Internet use frequency accounted for the Latino versus White difference in initiating online participation, but not the Black versus White difference. Future online HIV prevention interventions recruiting diverse YMSM should focus on initiating online engagement among Black participants.

Examining Racial and Ethnic Minority Differences among YMSM during Recruitment for an Online HIV Prevention Intervention Study

PubMed Central

Du Bois, Steve N.; Johnson, Sarah E.; Mustanski, Brian

2011-01-01

HIV disproportionately affects racial and ethnic minority young men who have sex with men (YMSM). HIV prevention research does not include these YMSM commensurate to their HIV burden. We examined racial and ethnic differences during a unique three-step recruitment process for an online, YMSM HIV prevention intervention study (N=660). Step one was completed in-person; steps two and three online. Fewer Black and Latino YMSM completed step two – initiating online participation – than White YMSM. Internet use frequency accounted for the Latino vs. White difference in initiating online participation, but not the Black vs. White difference. Future online HIV prevention interventions recruiting diverse YMSM should focus on initiating online engagement among Black participants. PMID:21986869

Results of a prospective clinical study on the diagnostic performance of standard magnetic resonance imaging in comparison to a combination of 3T MRI and additional CT imaging in Kienböck's disease.

PubMed

Stahl, Stephane; Hentschel, Pascal; Ketelsen, Dominik; Grosse, Ulrich; Held, Manuel; Wahler, Theodora; Syha, Roland; Schaller, Hans-Eberhard; Nikolaou, Konstantin; Grözinger, Gerd

2017-05-01

This prospective clinical study examined standard wrist magnetic resonance imaging (MRI) examinations and the incremental value of computed tomography (CT) in the diagnosis of Kienböck's disease (KD) with regard to reliability and precision in the different diagnostic steps during diagnostic work-up. Sixty-four consecutive patients referred between January 2009 and January 2014 with positive initial suspicion of KD according to external standard wrist MRI were prospectively included (step one). Institutional review board approval was obtained. Clinical examination by two handsurgeons were followed by wrist radiographs (step two), ultrathin-section CT, and 3T contrast-enhanced MRI (step three). Final diagnosis was established in a consensus conference involving all examiners and all examinations results available from step three. In 12/64 patients, initial suspicion was discarded at step two and in 34/64 patients, the initial suspicion of KD was finally discarded at step three. The final external MRI positive predictive value was 47%. The most common differential diagnoses at step three were intraosseous cysts (n=15), lunate pseudarthrosis (n=13), and ulnar impaction syndrome (n=5). A correlation between radiograph-based diagnoses (step two) with final diagnosis (step three) showed that initial suspicion of stage I KD had the lowest sensitivity for correct diagnosis (2/11). Technical factors associated with a false positive external MRI KD diagnosis were not found. Standard wrist MRI should be complemented with thin-section CT, and interdisciplinary interpretation of images and clinical data, to increase diagnostic accuracy in patients with suspected KD. Copyright © 2017. Published by Elsevier B.V.

Critical induction a key quantity for the optimisation of transformer core operation

NASA Astrophysics Data System (ADS)

Ilo, A.; Pfützner, H.; Nakata, T.

2000-06-01

No-load losses P of transformers core have been considerably decreased through introduction of the so-called multi-step-lap designs. However, profound guidelines for the optimum step-number N do not exist. This study shows that the combination of both N and working induction B characterises the flux distribution. Transformer cores can operate in an over or an under-critical way depending on N and B.

The European cooperative approach to securing critical information infrastructure.

PubMed

Purser, Steve

2011-10-01

This paper provides an overview of the EU approach to securing critical information infrastructure, as defined in the Action Plan contained in the Commission Communication of March 2009, entitled 'Protecting Europe from large-scale cyber-attacks and disruptions: enhancing preparedness, security and resilience' and further elaborated by the Communication of May 2011 on critical Information infrastructure protection 'Achievements and next steps: towards global cyber-security'. After explaining the need for pan-European cooperation in this area, the CIIP Action Plan is explained in detail. Finally, the current state of progress is summarised together with the proposed next steps.

Birth order dependent growth cone segregation determines synaptic layer identity in the Drosophila visual system.

PubMed

Kulkarni, Abhishek; Ertekin, Deniz; Lee, Chi-Hon; Hummel, Thomas

2016-03-17

The precise recognition of appropriate synaptic partner neurons is a critical step during neural circuit assembly. However, little is known about the developmental context in which recognition specificity is important to establish synaptic contacts. We show that in the Drosophila visual system, sequential segregation of photoreceptor afferents, reflecting their birth order, lead to differential positioning of their growth cones in the early target region. By combining loss- and gain-of-function analyses we demonstrate that relative differences in the expression of the transcription factor Sequoia regulate R cell growth cone segregation. This initial growth cone positioning is consolidated via cell-adhesion molecule Capricious in R8 axons. Further, we show that the initial growth cone positioning determines synaptic layer selection through proximity-based axon-target interactions. Taken together, we demonstrate that birth order dependent pre-patterning of afferent growth cones is an essential pre-requisite for the identification of synaptic partner neurons during visual map formation in Drosophila.

Acyl-CoA synthetase 3 promotes lipid droplet biogenesis in ER microdomains

PubMed Central

Kassan, Adam; Herms, Albert; Fernández-Vidal, Andrea; Bosch, Marta; Schieber, Nicole L.; Reddy, Babu J.N.; Fajardo, Alba; Gelabert-Baldrich, Mariona; Tebar, Francesc; Enrich, Carlos; Gross, Steven P.

2013-01-01

Control of lipid droplet (LD) nucleation and copy number are critical, yet poorly understood, processes. We use model peptides that shift from the endoplasmic reticulum (ER) to LDs in response to fatty acids to characterize the initial steps of LD formation occurring in lipid-starved cells. Initially, arriving lipids are rapidly packed in LDs that are resistant to starvation (pre-LDs). Pre-LDs are restricted ER microdomains with a stable core of neutral lipids. Subsequently, a first round of “emerging” LDs is nucleated, providing additional lipid storage capacity. Finally, in proportion to lipid concentration, new rounds of LDs progressively assemble. Confocal microscopy and electron tomography suggest that emerging LDs are nucleated in a limited number of ER microdomains after a synchronized stepwise process of protein gathering, lipid packaging, and recognition by Plin3 and Plin2. A comparative analysis demonstrates that the acyl-CoA synthetase 3 is recruited early to the assembly sites, where it is required for efficient LD nucleation and lipid storage. PMID:24368806

Modeling of an initial stage of bone fracture healing

NASA Astrophysics Data System (ADS)

Lu, Yanfei; Lekszycki, Tomasz

2015-09-01

In case of the secondary bone fracture healing, four characteristic steps are often distinguished. The first stage, hematoma and clot formation, which is an object of our study, is important because it prepares the environment for the following stages. In this work, a new mathematical model describing basic effects present short after the injury is proposed. The main idea is based on the assumption that blood leaking from the ruptured blood vessels propagates into a poroelastic saturated tissue close to the fracture and mixes with the interstitial liquid present in pores. After certain time period from the first contact with surrounding tissue, the solidification of blood in the fluid mixture starts. This results in clot formation. By assuming the time necessary to initiate solidification and critical saturation of blood in the mixture, the shape and the structure of blood clot could be determined. In numerical example, proposed mathematical formulas were used to study the size of the gap between fractured parts and its effect in blood clot formation.

Bacterial Sigma Factors and Anti-Sigma Factors: Structure, Function and Distribution

PubMed Central

Paget, Mark S.

2015-01-01

Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play critical roles in transcription initiation, including the recognition and opening of promoters as well as the initial steps in RNA synthesis. This review focuses on the structure and function of the major sigma-70 class that includes the housekeeping sigma factor (Group 1) that directs the bulk of transcription during active growth, and structurally-related alternative sigma factors (Groups 2–4) that control a wide variety of adaptive responses such as morphological development and the management of stress. A recurring theme in sigma factor control is their sequestration by anti-sigma factors that occlude their RNAP-binding determinants. Sigma factors are then released through a wide variety of mechanisms, often involving branched signal transduction pathways that allow the integration of distinct signals. Three major strategies for sigma release are discussed: regulated proteolysis, partner-switching, and direct sensing by the anti-sigma factor. PMID:26131973

Reactive pathways of hydrogen and carbon removal from organosilicate glass low- κ films by F atoms

NASA Astrophysics Data System (ADS)

Voronina, Ekaterina N.; Mankelevich, Yuri A.; Rakhimova, Tatyana V.

2017-07-01

Direct molecular dynamic simulation on the base of the density functional theory (DFT) method is used to study some critical reactions of F atoms with organosilicate glass (OSG) low-κ films. Here static and dynamic DFT-based approaches are applied for a variety of reactive pathways of hydrogen and carbon removal in the form of volatile products (HF, CF2 and CF3 molecules) from initial SiCH3 surface groups. These reactions constitute an important part of the proposed multi-step mechanism of OSG films damage and etching by thermal F atoms. Two models (POSS and TMCTS macromolecules and their modifications) are used to illustrate the peculiarities and dynamics of the successive reactions of F atoms with the initial SiCH3 and appeared SiCHxFy (x + y ≤ 3) surface groups. Contribution to the Topical Issue "Dynamics of Molecular Systems (MOLEC 2016)", edited by Alberto Garcia-Vela, Luis Banares and Maria Luisa Senent.

Fracture control methods for space vehicles. Volume 1: Fracture control design methods. [for space shuttle configuration planning

NASA Technical Reports Server (NTRS)

Liu, A. F.

1974-01-01

A systematic approach for applying methods for fracture control in the structural components of space vehicles consists of four major steps. The first step is to define the primary load-carrying structural elements and the type of load, environment, and design stress levels acting upon them. The second step is to identify the potential fracture-critical parts by means of a selection logic flow diagram. The third step is to evaluate the safe-life and fail-safe capabilities of the specified part. The last step in the sequence is to apply the control procedures that will prevent damage to the fracture-critical parts. The fracture control methods discussed include fatigue design and analysis methods, methods for preventing crack-like defects, fracture mechanics analysis methods, and nondestructive evaluation methods. An example problem is presented for evaluation of the safe-crack-growth capability of the space shuttle crew compartment skin structure.

Stepping up for Childhood: A Contextual Critical Methodology

ERIC Educational Resources Information Center

Kyriacopoulos, Konstantine; Sánchez, Marta

2017-01-01

In this paper, we theorize a critical methodology for education centering community experiences of systemic injustice, drawing upon Critical Race Theory, critical educational leadership studies, Chicana feminism, participant action research and political theory, to refocus our work on the human relationships at the center of the learning and…

The role of template superhelicity in the initiation of bacteriophage lambda DNA replication.

PubMed Central

Alfano, C; McMacken, R

1988-01-01

The prepriming steps in the initiation of bacteriophage lambda DNA replication depend on the action of the lambda O and P proteins and on the DnaB helicase, single-stranded DNA binding protein (SSB), and DnaJ and DnaK heat shock proteins of the E. coli host. The binding of multiple copies of the lambda O protein to the phage replication origin (ori lambda) initiates the ordered assembly of a series of nucleoprotein structures that form at ori lambda prior to DNA unwinding, priming and DNA synthesis steps. Since the initiation of lambda DNA replication is known to occur only on supercoiled templates in vivo and in vitro, we examined how the early steps in lambda DNA replication are influenced by superhelical tension. All initiation complexes formed prior to helicase-mediated DNA-unwinding form with high efficiency on relaxed ori lambda DNA. Nonetheless, the DNA templates in these structures must be negatively supertwisted before they can be replicated. Once DNA helicase unwinding is initiated at ori lambda, however, later steps in lambda DNA replication proceed efficiently in the absence of superhelical tension. We conclude that supercoiling is required during the initiation of lambda DNA replication to facilitate entry of a DNA helicase, presumably the DnaB protein, between the DNA strands. Images PMID:2847118

Two-step rocket engine bipropellant valve concept

NASA Technical Reports Server (NTRS)

Capps, J. E.; Ferguson, R. E.; Pohl, H. O.

1969-01-01

Initiating combustion of altitude control rocket engines in a precombustion chamber of ductile material reduces high pressure surges generated by hypergolic propellants. Two-step bipropellant valve concepts control initial propellant flow into precombustion chamber and subsequent full flow into main chamber.

A survey of critical care nurses' practices and perceptions surrounding early intravenous antibiotic initiation during septic shock.

PubMed

Roberts, Russel J; Alhammad, Abdullah M; Crossley, Lindsay; Anketell, Eric; Wood, LeeAnn; Schumaker, Greg; Garpestad, Erik; Devlin, John W

2017-08-01

Delays in antibiotic administration after severe sepsis recognition increases mortality. While physician and pharmacy-related barriers to early antibiotic initiation have been well evaluated, those factors that affect the speed by which critical care nurses working in either the emergency department or the intensive care unit setting initiate antibiotic therapy remains poorly characterized. To evaluate the knowledge, practices and perceptions of critical care nurses regarding antibiotic initiation in patients with newly recognised septic shock. A validated survey was distributed to 122 critical care nurses at one 320-bed academic institution with a sepsis protocol advocating intravenous(IV) antibiotic initiation within 1hour of shock recognition. Among 100 (82%) critical care nurses responding, nearly all (98%) knew of the existence of the sepsis protocol. However, many critical care nurses stated they would optimise blood pressure [with either fluid (38%) or both fluid and a vasopressor (23%)] before antibiotic initiation. Communicated barriers to rapid antibiotic initiation included: excessive patient workload (74%), lack of awareness IV antibiotic(s) ordered (57%) or delivered (69%), need for administration of multiple non-antibiotic IV medications (54%) and no IV access (51%). Multiple nurse-related factors influence IV antibiotic(s) initiation speed and should be incorporated into sepsis quality improvement efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Timing of the initiation of parenteral nutrition in critically ill children.

PubMed

Jimenez, Lissette; Mehta, Nilesh M; Duggan, Christopher P

2017-05-01

To review the current literature evaluating clinical outcomes of early and delayed parenteral nutrition initiation among critically ill children. Nutritional management remains an important aspect of care among the critically ill, with enteral nutrition generally preferred. However, inability to advance enteral feeds to caloric goals and contraindications to enteral nutrition often leads to reliance on parenteral nutrition. The timing of parenteral nutrition initiation is varied among critically ill children, and derives from an assessment of nutritional status, energy requirements, and physiologic differences between adults and children, including higher nutrient needs and lower body reserves. A recent randomized control study among critically ill children suggests improved clinical outcomes with avoiding initiation of parenteral nutrition on day 1 of admission to the pediatric ICU. Although there is no consensus on the optimal timing of parenteral nutrition initiation among critically ill children, recent literature does not support the immediate initiation of parenteral nutrition on pediatric ICU admission. A common theme in the reviewed literature highlights the importance of accurate assessment of nutritional status and energy expenditure in deciding when to initiate parenteral nutrition. As with all medical interventions, the initiation of parenteral nutrition should be considered in light of the known benefits of judiciously provided nutritional support with the known risks of artificial, parenteral feeding.

Timing of the initiation of parenteral nutrition in critically ill children

PubMed Central

Jimenez, Lissette; Mehta, Nilesh M.; Duggan, Christopher

2018-01-01

Purpose of Review To review the current literature evaluating clinical outcomes of early and delayed parenteral nutrition initiation among critically ill children. Recent Findings Nutritional management remains an important aspect of care among the critically ill, with enteral nutrition (EN) generally preferred. However, inability to advance enteral feeds to caloric goals and contraindications to EN often leads to reliance on parenteral nutrition (PN). The timing of PN initiation is varied among critically ill children, and derives from an assessment of nutritional status, energy requirements, and physiologic differences between adults and children, including higher nutrient needs and lower body reserves. A recent randomized control study among critically ill children suggests improved clinical outcomes with postponing initiation of PN to 1 week after admission to the pediatric intensive care unit (PICU). Summary Although there is no consensus on the optimal timing of PN initiation among critically ill children, recent literature does not support the immediate initiation of PN on PICU admission. A common theme in the reviewed literature highlights the importance of accurate assessment of nutritional status and energy expenditure in deciding when to initiate PN. As with all medical interventions, the initiation of PN should be considered in light of the known benefits of judiciously provided nutritional support with the known risks of artificial, parenteral feeding. PMID:28376054

A generalized theory of thin film growth

NASA Astrophysics Data System (ADS)

Du, Feng; Huang, Hanchen

2018-03-01

This paper reports a theory of thin film growth that is generalized for arbitrary incidence angle during physical vapor deposition in two dimensions. The accompanying kinetic Monte Carlo simulations serve as verification. A special theory already exists for thin film growth with zero incidence angle, and another theory also exists for nanorod growth with a glancing angle. The theory in this report serves as a bridge to describe the transition from thin film growth to nanorod growth. In particular, this theory gives two critical conditions in analytical form of critical coverage, ΘI and ΘII. The first critical condition defines the onset when crystal growth or step dynamics stops following the wedding cake model for thin film growth. The second critical condition defines the onset when multiple-layer surface steps form to enable nanorod growth. Further, this theory also reveals a critical incidence angle, below which nanorod growth is impossible. The critical coverages, together with the critical incidence angle, defines a phase diagram of thin growth versus nanorod growth.

Validity of contents of a paediatric critical comfort scale using mixed methodology.

PubMed

Bosch-Alcaraz, A; Jordan-Garcia, I; Alcolea-Monge, S; Fernández-Lorenzo, R; Carrasquer-Feixa, E; Ferrer-Orona, M; Falcó-Pegueroles, A

Critical illness in paediatric patients includes acute conditions in a healthy child as well as exacerbations of chronic disease, and therefore these situations must be clinically managed in Critical Care Units. The role of the paediatric nurse is to ensure the comfort of these critically ill patients. To that end, instruments are required that correctly assess critical comfort. To describe the process for validating the content of a paediatric critical comfort scale using mixed-method research. Initially, a cross-cultural adaptation of the Comfort Behavior Scale from English to Spanish using the translation and back-translation method was made. After that, its content was evaluated using mixed method research. This second step was divided into a quantitative stage in which an ad hoc questionnaire was used in order to assess each scale's item relevance and wording and a qualitative stage with two meetings with health professionals, patients and a family member following the Delphi Method recommendations. All scale items obtained a content validity index >0.80, except physical movement in its relevance, which obtained 0.76. Global content scale validity was 0.87 (high). During the qualitative stage, items from each of the scale domains were reformulated or eliminated in order to make the scale more comprehensible and applicable. The use of a mixed-method research methodology during the scale content validity phase allows the design of a richer and more assessment-sensitive instrument. Copyright © 2017 Sociedad Española de Enfermería Intensiva y Unidades Coronarias (SEEIUC). Publicado por Elsevier España, S.L.U. All rights reserved.

Postural adjustment errors reveal deficits in inhibition during lateral step initiation in older adults

PubMed Central

Fuhrman, Susan I.; Redfern, Mark S.; Jennings, J. Richard; Perera, Subashan; Nebes, Robert D.; Furman, Joseph M.

2013-01-01

Postural dual-task studies have demonstrated effects of various executive function components on gait and postural control in older adults. The purpose of the study was to explore the role of inhibition during lateral step initiation. Forty older adults participated (range 70–94 yr). Subjects stepped to the left or right in response to congruous and incongruous visual cues that consisted of left and right arrows appearing on left or right sides of a monitor. The timing of postural adjustments was identified by inflection points in the vertical ground reaction forces (VGRF) measured separately under each foot. Step responses could be classified into preferred and nonpreferred step behavior based on the number of postural adjustments that were made. Delays in onset of the first postural adjustment (PA1) and liftoff (LO) of the step leg during preferred steps progressively increased among the simple, choice, congruous, and incongruous tasks, indicating interference in processing the relevant visuospatial cue. Incongruous cues induced subjects to make more postural adjustments than they typically would (i.e., nonpreferred steps), representing errors in selection of the appropriate motor program. During these nonpreferred steps, the onset of the PA1 was earlier than during the preferred steps, indicating a failure to inhibit an inappropriate initial postural adjustment. The functional consequence of the additional postural adjustments was a delay in the LO compared with steps in which they did not make an error. These results suggest that deficits in inhibitory function may detrimentally affect step decision processing, by delaying voluntary step responses. PMID:23114211

Timing paradox of stepping and falls in ageing: not so quick and quick(er) on the trigger

PubMed Central

Mille, Marie‐Laure

2016-01-01

Abstract Physiological and degenerative changes affecting human standing balance are major contributors to falls with ageing. During imbalance, stepping is a powerful protective action for preserving balance that may be voluntarily initiated in recognition of a balance threat, or be induced by an externally imposed mechanical or sensory perturbation. Paradoxically, with ageing and falls, initiation slowing of voluntary stepping is observed together with perturbation‐induced steps that are triggered as fast as or faster than for younger adults. While age‐associated changes in sensorimotor conduction, central neuronal processing and cognitive functions are linked to delayed voluntary stepping, alterations in the coupling of posture and locomotion may also prolong step triggering. It is less clear, however, how these factors may explain the accelerated triggering of induced stepping. We present a conceptual model that addresses this issue. For voluntary stepping, a disruption in the normal coupling between posture and locomotion may underlie step‐triggering delays through suppression of the locomotion network based on an estimation of the evolving mechanical state conditions for stability. During induced stepping, accelerated step initiation may represent an event‐triggering process whereby stepping is released according to the occurrence of a perturbation rather than to the specific sensorimotor information reflecting the evolving instability. In this case, errors in the parametric control of induced stepping and its effectiveness in stabilizing balance would be likely to occur. We further suggest that there is a residual adaptive capacity with ageing that could be exploited to improve paradoxical triggering and other changes in protective stepping to impact fall risk. PMID:26915664

Sensory gating for the initiation of the swing phase in different directions of human infant stepping.

PubMed

Pang, Marco Y C; Yang, Jaynie F

2002-07-01

Humans can make smooth, continuous transitions in walking direction from forward to backward. Thus, the processing of sensory input must allow a similar continuum of possibilities. Hip extension and reduced load are two important conditions that control the transition from the stance to swing phase during forward stepping in human infants. The purpose of this study was to determine whether the same factors also regulate the initiation of the swing phase in other directions of stepping. Thirty-seven infants between the ages of 5 and 13 months were studied during supported forward and sideways stepping on a treadmill. Disturbances were elicited by placing a piece of cardboard under the foot and pulling the cardboard in different directions. In this way, the leg was displaced in a particular direction and simultaneously unloaded. We observed whether the swing phase was immediately initiated after the application of disturbances in various directions. Electromyography, vertical ground reaction forces, and hip motion in frontal and sagittal planes were recorded. The results showed that the most potent sensory input to initiate the swing phase depends on the direction of stepping. Although low load was always necessary to initiate swing for all directions of walking, the preferred hip position was always one directly opposite the direction of walking. The results indicated the presence of selective gating of sensory input from the legs as a function of the direction of stepping.

48 CFR 52.214-25 - Step Two of Two-Step Sealed Bidding.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Step Two of Two-Step... Clauses 52.214-25 Step Two of Two-Step Sealed Bidding. As prescribed in 14.201-6(t), insert the following provision: Step Two of Two-Step Sealed Bidding (APR 1985) (a) This invitation for bids is issued to initiate...

Reforming Cookbook Labs

ERIC Educational Resources Information Center

Peters, Erin

2005-01-01

Deconstructing cookbook labs to require the students to be more thoughtful could break down perceived teacher barriers to inquiry learning. Simple steps that remove or disrupt the direct transfer of step-by-step procedures in cookbook labs make students think more critically about their process. Through trials in the author's middle school…

Coupling image processing and stress analysis for damage identification in a human premolar tooth.

PubMed

Andreaus, U; Colloca, M; Iacoviello, D

2011-08-01

Non-carious cervical lesions are characterized by the loss of dental hard tissue at the cement-enamel junction (CEJ). Exceeding stresses are therefore generated in the cervical region of the tooth that cause disruption of the bonds between the hydroxyapatite crystals, leading to crack formation and eventual loss of enamel and the underlying dentine. Damage identification was performed by image analysis techniques and allowed to quantitatively assess changes in teeth. A computerized two-step procedure was generated and applied to the first left maxillary human premolar. In the first step, dental images were digitally processed by a segmentation method in order to identify the damage. The considered morphological properties were the enamel thickness and total area, the number of fragments in which the enamel is chipped. The information retrieved by the data processing of the section images allowed to orient the stress investigation toward selected portions of the tooth. In the second step, a three-dimensional finite element model based on CT images of both the tooth and the periodontal ligament was employed to compare the changes occurring in the stress distributions in normal occlusion and malocclusion. The stress states were analyzed exclusively in the critical zones designated in the first step. The risk of failure at the CEJ and of crack initiation at the dentin-enamel junction through the quantification of first and third principal stresses, von Mises stress, and normal and tangential stresses, were also estimated. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Ca2+ spike initiation from sensitized inositol 1,4,5-trisphosphate-sensitive Ca2+ stores in megakaryocytes.

PubMed

Ikeda, M; Kurokawa, K; Maruyama, Y

1994-06-01

Ca(2+)-mediated Ca2+ spikes were analysed in fura-2-loaded megakaryocytes. Direct Ca2+ loading using whole-cell dialysis induced an all-or-none Ca2+ spike on top of a tonic increase in cellular Ca2+ concentration ([Ca2+]i) with a latency of 3-7 s. The latency decreased with increasingly higher concentrations of Ca2+ in the dialysing solution. Spike size and its initiation did not correlate with the tonic level of [Ca2+]i. Thapsigargin completely abolished the Ca(2+)-induced spike initiation, suggesting that Ca2+ spikes originate from thapsigargin-sensitive Ca2+ pools. An inhibitor of phosphatidylinositide-specific phospholipase C (PLC), 2-nitro-4-carboxyphenyl-N,N-diphenyl-carbamate prolonged the latency without changes of spike size in most cases (6/9 cells), but abolished the spike initiation in the other cells (3/9). The results suggest that an increase in [Ca2+]i charges up the inositol-1,4,5-trisphosphate-(InsP3)- and thapsigargin-sensitive Ca2+ pools which progressively sensitize to low or slightly elevated levels of InsP3 by the action of Ca(2+)-dependent PLC until a critical Ca2+ content is reached, and then the Ca2+ spike is triggered. Thus, the limiting step of Ca2+ spike triggering is the initial filling process and the level of InsP3 in megakaryocytes.

High-Throughput Screening and Quantitative Chemical Ranking for Sodium-Iodide Symporter Inhibitors in ToxCast Phase I Chemical Library.

PubMed

Wang, Jun; Hallinger, Daniel R; Murr, Ashley S; Buckalew, Angela R; Simmons, Steven O; Laws, Susan C; Stoker, Tammy E

2018-05-01

Thyroid uptake of iodide via the sodium-iodide symporter (NIS) is the first step in the biosynthesis of thyroid hormones that are critical for health and development in humans and wildlife. Despite having long been a known target of endocrine disrupting chemicals such as perchlorate, information regarding NIS inhibition activity is still unavailable for the vast majority of environmental chemicals. This study applied a previously validated high-throughput approach to screen for NIS inhibitors in the ToxCast phase I library, representing 293 important environmental chemicals. Here 310 blinded samples were screened in a tiered-approach using an initial single-concentration (100 μM) radioactive-iodide uptake (RAIU) assay, followed by 169 samples further evaluated in multi-concentration (0.001 μM-100 μM) testing in parallel RAIU and cell viability assays. A novel chemical ranking system that incorporates multi-concentration RAIU and cytotoxicity responses was also developed as a standardized method for chemical prioritization in current and future screenings. Representative chemical responses and thyroid effects of high-ranking chemicals are further discussed. This study significantly expands current knowledge of NIS inhibition potential in environmental chemicals and provides critical support to U.S. EPA's Endocrine Disruptor Screening Program (EDSP) initiative to expand coverage of thyroid molecular targets, as well as the development of thyroid adverse outcome pathways (AOPs).

Knowing your friends and foes--plant receptor-like kinases as initiators of symbiosis or defence.

PubMed

Antolín-Llovera, Meritxell; Petutsching, Elena Kristin; Ried, Martina Katharina; Lipka, Volker; Nürnberger, Thorsten; Robatzek, Silke; Parniske, Martin

2014-12-01

The decision between defence and symbiosis signalling in plants involves alternative and modular plasma membrane-localized receptor complexes. A critical step in their activation is ligand-induced homo- or hetero-oligomerization of leucine-rich repeat (LRR)- and/or lysin motif (LysM) receptor-like kinases (RLKs). In defence signalling, receptor complexes form upon binding of pathogen-associated molecular patterns (PAMPs), including the bacterial flagellin-derived peptide flg22, or chitin. Similar mechanisms are likely to operate during the perception of microbial symbiont-derived (lipo)-chitooligosaccharides. The structurally related chitin-oligomer ligands chitooctaose and chitotetraose trigger defence and symbiosis signalling, respectively, and their discrimination involves closely related, if not identical, LysM-RLKs. This illustrates the demand for and the challenges imposed on decision mechanisms that ensure appropriate signal initiation. Appropriate signalling critically depends on abundance and localization of RLKs at the cell surface. This is regulated by internalization, which also provides a mechanism for the removal of activated signalling RLKs. Abundance of the malectin-like domain (MLD)-LRR-RLK Symbiosis Receptor-like Kinase (SYMRK) is additionally controlled by cleavage of its modular ectodomain, which generates a truncated and rapidly degraded RLK fragment. This review explores LRR- and LysM-mediated signalling, the involvement of MLD-LRR-RLKs in symbiosis and defence, and the role of endocytosis in RLK function. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Critical factors determining the variation in SOA yields from terpene ozonolysis: a combined experimental and computational study.

PubMed

Donahue, Neil M; Hartz, Kara E Huff; Chuong, Bao; Presto, Albert A; Stanier, Charles O; Rosenhørn, Thomas; Robinson, Allen L; Pandis, Spyros N

2005-01-01

A substantial fraction of the total ultrafine particulate mass is comprised of organic compounds. Of this fraction, a significant subfraction is secondary organic aerosol (SOA), meaning that the compounds are a by-product of chemistry in the atmosphere. However, our understanding of the kinetics and mechanisms leading to and following SOA formation is in its infancy. We lack a clear description of critical phenomena; we often don't know the key, rate limiting steps in SOA formation mechanisms. We know almost nothing about aerosol yields past the first generation of oxidation products. Most importantly, we know very little about the derivatives in these mechanisms; we do not understand how changing conditions, be they precursor levels, oxidant concentrations, co-reagent concentrations (i.e., the VOC/NOx ratio) or temperature will influence the yields of SOA. In this paper we explore the connections between fundamental details of physical chemistry and the multitude of steps associated with SOA formation, including the initial gas-phase reaction mechanisms leading to condensible products, the phase partitioning itself, and the continued oxidation of the condensed-phase organic products. We show that SOA yields in the alpha-pinene + ozone are highly sensitive to NOx, and that SOA yields from beta-caryophylene + ozone appear to increase with continued ozone exposure, even as aerosol hygroscopicity increases as well. We suggest that SOA yields are likely to increase substantially through several generations of oxidative processing of the semi-volatile products.

Mutational analysis of human RNA polymerase II subunit 5 (RPB5): the residues critical for interactions with TFIIF subunit RAP30 and hepatitis B virus X protein.

PubMed

Le, Thi Thu Thuy; Zhang, Shijun; Hayashi, Naoyuki; Yasukawa, Mami; Delgermaa, Luvsanjav; Murakami, Seishi

2005-09-01

RNA polymerase II (RNAPII) subunit 5 (RPB5) is positioned close to DNA downstream of the initiation site and is the site of interaction with several regulators. Hepatitis B virus X protein (HBx) binds the central part of RPB5 to modulate activated transcription, and TFIIF subunit RAP30 interacts with the same part of RPB5 that is critical for the association between TFIIF and RNAPII. However the residues necessary for these interactions remain unknown. Here we report systematic mutagenesis of the central part of RPB5 using two-step alanine scanning libraries to pinpoint critical residues for its binding to RAP30 in the TFIIF complex and/or to HBx, and identified these residues in both mammalian cells and in an in vitro binding assay. Four residues, F76, I104, T111 and S113, are critical for both TFIIF- and HBx-binding, indicating the overlapping nature of the sites of interaction. In addition, V74 and N98 are required for HBx-binding, and T56 and L58 are needed for RAP30-binding. Interestingly the residues exposed to solvent, T111 and S113, are very close to the DNA, implying that two factors may modulate the interaction between DNA and RPB5.

Optimizing health information technology's role in enabling comparative effectiveness research.

PubMed

Navathe, Amol S; Conway, Patrick H

2010-12-01

Health information technology (IT) is a key enabler of comparative effectiveness research (CER). Health IT standards for data sharing are essential to advancing the research data infrastructure, and health IT is critical to the next step of incorporating clinical data into data sources. Four key principles for advancement of CER are (1) utilization of data as a strategic asset, (2) leveraging public-private partnerships, (3) building robust, scalable technology platforms, and (4) coordination of activities across government agencies. To maximize the value of the resources, payers and providers must contribute data to initiatives, engage with government agencies on lessons learned, continue to develop new technologies that address key challenges, and utilize the data to improve patient outcomes and conduct research.

Long length coated conductor fabrication by inclined substrate deposition and evaporation

NASA Astrophysics Data System (ADS)

Prusseit, W.; Hoffmann, C.; Nemetschek, R.; Sigl, G.; Handke, J.; Lümkemann, A.; Kinder, H.

2006-06-01

The commercial development of coated conductors is rapidly progressing. As a result we present an economic route to produce second generation HTS tape from the initial substrate preparation to the final metal coating. The most important and technically challenging steps are the deposition of an oriented buffer layer and the superconductor film in a reel-to-reel configuration. New evaporation techniques have been developed to enable reliable, high rate tape coating. Highly oriented MgO - buffer layers are realized by inclined substrate deposition (ISD) and DyBCO is deposited by simple e-gun evaporation yielding critical currents beyond 200 A/cm. Coated conductors have been fabricated up to 40 m length and are currently tested in a variety of applications.

The Daniel K. Inouye College of Pharmacy Scripts

PubMed Central

Ciarleglio, Anita E; Ma, Carolyn

2017-01-01

The precision medicine initiative brought forth by President Barack Obama in 2015 is an important step on the journey to truly personalized medicine. A broad knowledge and understanding of the implications of the pharmacogenomic literature will be critical to the achievement of this goal. While a great amount of data has been published in the areas of pharmacogenomics and pharmacogenetics, there are still relatively few instances in which the need for clinical intervention can be stated without doubt, and which are widely accepted and practiced by the medical community. As our knowledge base rapidly expands, issues such as insurance reimbursement for genetic testing and education of the health care workforce will be paramount to achieving the goal of precision medicine for all patients. PMID:28900583

Mathematical Modeling of the Origins of Life

NASA Technical Reports Server (NTRS)

Pohorille, Andrew

2006-01-01

The emergence of early metabolism - a network of catalyzed chemical reactions that supported self-maintenance, growth, reproduction and evolution of the ancestors of contemporary cells (protocells) was a critical, but still very poorly understood step on the path from inanimate to animate matter. Here, it is proposed and tested through mathematical modeling of biochemically plausible systems that the emergence of metabolism and its initial evolution towards higher complexity preceded the emergence of a genome. Even though the formation of protocellular metabolism was driven by non-genomic, highly stochastic processes the outcome was largely deterministic, strongly constrained by laws of chemistry. It is shown that such concepts as speciation and fitness to the environment, developed in the context of genomic evolution, also held in the absence of a genome.

Carbon Nanotubes Exposure Risk Assessment: From Toxicology to Epidemiologic Studies (Overview of the Current Problem)

PubMed Central

Fatkhutdinova, L. M.; Khaliullin, T. O.; Shvedova, A. A.

2015-01-01

Nanoscale size and fiber like structure of carbon nanotubes (CNTs) may determine high reactivity and penetration, as well as the pathogenicity of asbestos and other mineral fibers. Despite many in vitro and in vivo studies, the absence of full-scale data on CNT effects on human health clearly point out the necessity for epidemiological studies. Currently, several projects are initiated worldwide on studying health risks associated with the inhalation of industrial CNTs, including NIOSH-promoted research (United States), the European CANTES study, and the Russian CNT-ERA project. Studies comprising several successive steps, such as CNT exposure assessment in occupational settings, toxicological evaluation, and epidemiological observations, are critical for determining material safety and use criteria. PMID:26457172

Plasma Discharge Process in a Pulsed Diaphragm Discharge System

NASA Astrophysics Data System (ADS)

Duan, Jianjin; Hu, Jue; Zhang, Chao; Wen, Yuanbin; Meng, Yuedong; Zhang, Chengxu

2014-12-01

As one of the most important steps in wastewater treatment, limited study on plasma discharge process is a key challenge in the development of plasma applications. In this study, we focus on the plasma discharge process of a pulsed diaphragm discharge system. According to the analysis, the pulsed diaphragm discharge proceeds in seven stages: (1) Joule heating and heat exchange stage; (2) nucleated site formation; (3) plasma generation (initiation of the breakdown stage); (4) avalanche growth and plasma expansion; (5) plasma contraction; (6) termination of the plasma discharge; and (7) heat exchange stage. From this analysis, a critical voltage criterion for breakdown is obtained. We anticipate this finding will provide guidance for a better application of plasma discharges, especially diaphragm plasma discharges.

Assessment of molecular contamination in mask pod

NASA Astrophysics Data System (ADS)

Foray, Jean Marie; Dejaune, Patrice; Sergent, Pierre; Gough, Stuart; Cheung, D.; Davenet, Magali; Favre, Arnaud; Rude, C.; Trautmann, T.; Tissier, Michel; Fontaine, H.; Veillerot, M.; Avary, K.; Hollein, I.; Lerit, R.

2008-04-01

Context/ study Motivation: Contamination and especially Airbone Molecular Contamination (AMC) is a critical issue for mask material flow with a severe and fairly unpredictable risk of induced contamination and damages especially for 193 nm lithography. It is therefore essential to measure, to understand and then try to reduce AMC in mask environment. Mask material flow was studied in a global approach by a pool of European partners, especially within the frame of European MEDEA+ project, so called "MUSCLE". This paper deals with results and assessment of mask pod environment in term of molecular contamination in a first step, then in a second step preliminary studies to reduce mask pod influence and contamination due to material out gassing. Approach and techniques: A specific assessment of environmental / molecular contamination along the supply chain was performed by all partners. After previous work presented at EMLC 07, further studies were performed on real time contamination measurement pod at different sites locations (including Mask manufacturing site, blank manufacturing sites, IC fab). Studies were linked to the main critical issues: cleaning, storage, handling, materials and processes. Contamination measurement campaigns were carried out along the mask supply chain using specific Adixen analyzer in order to monitor in real time organic contaminants (ppb level) in mask pods. Key results would be presented: VOC, AMC and humidity level on different kinds of mask carriers, impact of basic cleaning on pod outgassing measurement (VOC, NH3), and process influence on pod contamination... In a second step, preliminary specific pod conditioning studies for better pod environment were performed based on Adixen vacuum process. Process influence had been experimentally measured in term of molecular outgassing from mask pods. Different AMC experimental characterization methods had been carried out leading to results on a wide range of organic and inorganic contaminants: by inline techniques based on Adixen humidity, also VOC and organic sensors, together by off-line techniques already used in the extensive previous mask pods benchmark (TD-GCMS & Ionic Chromatography). Humidity and VOC levels from mask carriers had shown significant reduction after Adixen pod conditioning process. Focus had been made on optimized vacuum step (for AMC) after particles carrier cleaning cycle. Based upon these key results new procedures, as well as guidelines for mask carrier cleaning optimization are proposed to improve pod contamination control. Summary results/next steps: This paper reports molecular contamination measurement campaigns performed by a pool of European partners along the mask supply chain. It allows us to investigate, identify and quantify critical molecular contamination in mask pod, as well as VOC and humidity, issues depending on locations, uses, and carrier's type. Preliminary studies highlight initial process solutions for pods conditioning that are being used for short term industrialization and further industrialized.

Systematic risk assessment methodology for critical infrastructure elements - Oil and Gas subsectors

NASA Astrophysics Data System (ADS)

Gheorghiu, A.-D.; Ozunu, A.

2012-04-01

The concern for the protection of critical infrastructure has been rapidly growing in the last few years in Europe. The level of knowledge and preparedness in this field is beginning to develop in a lawfully organized manner, for the identification and designation of critical infrastructure elements of national and European interest. Oil and gas production, refining, treatment, storage and transmission by pipelines facilities, are considered European critical infrastructure sectors, as per Annex I of the Council Directive 2008/114/EC of 8 December 2008 on the identification and designation of European critical infrastructures and the assessment of the need to improve their protection. Besides identifying European and national critical infrastructure elements, member states also need to perform a risk analysis for these infrastructure items, as stated in Annex II of the above mentioned Directive. In the field of risk assessment, there are a series of acknowledged and successfully used methods in the world, but not all hazard identification and assessment methods and techniques are suitable for a given site, situation, or type of hazard. As Theoharidou, M. et al. noted (Theoharidou, M., P. Kotzanikolaou, and D. Gritzalis 2009. Risk-Based Criticality Analysis. In Critical Infrastructure Protection III. Proceedings. Third Annual IFIP WG 11.10 International Conference on Critical Infrastructure Protection. Hanover, New Hampshire, USA, March 23-25, 2009: revised selected papers, edited by C. Palmer and S. Shenoi, 35-49. Berlin: Springer.), despite the wealth of knowledge already created, there is a need for simple, feasible, and standardized criticality analyses. The proposed systematic risk assessment methodology includes three basic steps: the first step (preliminary analysis) includes the identification of hazards (including possible natural hazards) for each installation/section within a given site, followed by a criterial analysis and then a detailed analysis step. The criterial evaluation is used as a ranking system in order to establish the priorities for the detailed risk assessment. This criterial analysis stage is necessary because the total number of installations and sections on a site can be quite large. As not all installations and sections on a site contribute significantly to the risk of a major accident occurring, it is not efficient to include all installations and sections in the detailed risk assessment, which can be time and resource consuming. The selected installations are then taken into consideration in the detailed risk assessment, which is the third step of the systematic risk assessment methodology. Following this step, conclusions can be drawn related to the overall risk characteristics of the site. The proposed methodology can as such be successfully applied to the assessment of risk related to critical infrastructure elements falling under the energy sector of Critical Infrastructure, mainly the sub-sectors oil and gas. Key words: Systematic risk assessment, criterial analysis, energy sector critical infrastructure elements

Mechanistic Kinetic Modeling of Thiol-Michael Addition Photopolymerizations via Photocaged "Superbase" Generators: An Analytical Approach.

PubMed

Claudino, Mauro; Zhang, Xinpeng; Alim, Marvin D; Podgórski, Maciej; Bowman, Christopher N

2016-11-08

A kinetic mechanism and the accompanying mathematical framework are presented for base-mediated thiol-Michael photopolymerization kinetics involving a photobase generator. Here, model kinetic predictions demonstrate excellent agreement with a representative experimental system composed of 2-(2-nitrophenyl)propyloxycarbonyl-1,1,3,3-tetramethylguanidine (NPPOC-TMG) as a photobase generator that is used to initiate thiol-vinyl sulfone Michael addition reactions and polymerizations. Modeling equations derived from a basic mechanistic scheme indicate overall polymerization rates that follow a pseudo-first-order kinetic process in the base and coreactant concentrations, controlled by the ratio of the propagation to chain-transfer kinetic parameters ( k p / k CT ) which is dictated by the rate-limiting step and controls the time necessary to reach gelation. Gelation occurs earlier as the k p / k CT ratio reaches a critical value, wherefrom gel times become nearly independent of k p / k CT . The theoretical approach allowed determining the effect of induction time on the reaction kinetics due to initial acid-base neutralization for the photogenerated base caused by the presence of protic contaminants. Such inhibition kinetics may be challenging for reaction systems that require high curing rates but are relevant for chemical systems that need to remain kinetically dormant until activated although at the ultimate cost of lower polymerization rates. The pure step-growth character of this living polymerization and the exhibited kinetics provide unique potential for extended dark-cure reactions and uniform material properties. The general kinetic model is applicable to photobase initiators where photolysis follows a unimolecular cleavage process releasing a strong base catalyst without cogeneration of intermediate radical species.

Electronic Nose Testing Procedure for the Definition of Minimum Performance Requirements for Environmental Odor Monitoring

PubMed Central

Eusebio, Lidia; Capelli, Laura; Sironi, Selena

2016-01-01

Despite initial enthusiasm towards electronic noses and their possible application in different fields, and quite a lot of promising results, several criticalities emerge from most published research studies, and, as a matter of fact, the diffusion of electronic noses in real-life applications is still very limited. In general, a first step towards large-scale-diffusion of an analysis method, is standardization. The aim of this paper is describing the experimental procedure adopted in order to evaluate electronic nose performances, with the final purpose of establishing minimum performance requirements, which is considered to be a first crucial step towards standardization of the specific case of electronic nose application for environmental odor monitoring at receptors. Based on the experimental results of the performance testing of a commercialized electronic nose type with respect to three criteria (i.e., response invariability to variable atmospheric conditions, instrumental detection limit, and odor classification accuracy), it was possible to hypothesize a logic that could be adopted for the definition of minimum performance requirements, according to the idea that these are technologically achievable. PMID:27657086

Electronic Nose Testing Procedure for the Definition of Minimum Performance Requirements for Environmental Odor Monitoring.

PubMed

Eusebio, Lidia; Capelli, Laura; Sironi, Selena

2016-09-21

Despite initial enthusiasm towards electronic noses and their possible application in different fields, and quite a lot of promising results, several criticalities emerge from most published research studies, and, as a matter of fact, the diffusion of electronic noses in real-life applications is still very limited. In general, a first step towards large-scale-diffusion of an analysis method, is standardization. The aim of this paper is describing the experimental procedure adopted in order to evaluate electronic nose performances, with the final purpose of establishing minimum performance requirements, which is considered to be a first crucial step towards standardization of the specific case of electronic nose application for environmental odor monitoring at receptors. Based on the experimental results of the performance testing of a commercialized electronic nose type with respect to three criteria (i.e., response invariability to variable atmospheric conditions, instrumental detection limit, and odor classification accuracy), it was possible to hypothesize a logic that could be adopted for the definition of minimum performance requirements, according to the idea that these are technologically achievable.

Adsorption of dissymmetric cationic gemini surfactants at silica/water interface

NASA Astrophysics Data System (ADS)

Sun, Yuhai; Feng, Yujun; Dong, Hongwei; Chen, Zhi

2007-05-01

Adsorption of a series of cationic gemini surfactants 12-2- m ( m = 8, 12, 16) on the surface of silica was investigated. The critical micelle concentrations, cmcs, of cationic gemini surfactants in the initial solutions and in the supernatants were measured by conductometry and tensiometer. The changes in cmc values indicate that the ion exchanges take place between polar groups of gemini surfactants adsorbed and ions bound on the surface of silica. The adsorption isotherms of cationic gemini surfactants were obtained by a solution depletion method. Based on the driving force, the adsorption includes two steps, one of which is ion exchange, and the other is hydrophobic interaction. In each step, the tendency of surfactant molecules in the solution to form aggregates or to be adsorbed on the silica varies with their structures. The maximum adsorption amount of gemini surfactants on the silica, τmax, decreases as increasing in the length of one alkyl chain, m, from 8, 12 to 16. So the results show that the adsorption behaviors of gemini surfactants are closely related to the dissymmetry of gemini molecules.

Best infection control practices for intradermal, subcutaneous, and intramuscular needle injections.

PubMed Central

Hutin, Yvan; Hauri, Anja; Chiarello, Linda; Catlin, Mary; Stilwell, Barbara; Ghebrehiwet, Tesfamicael; Garner, Julia

2003-01-01

OBJECTIVE: To draw up evidence-based guidelines to make injections safer. METHODS: A development group summarized evidence-based best practices for preventing injection-associated infections in resource-limited settings. The development process included a breakdown of the WHO reference definition of a safe injection into a list of potentially critical steps, a review of the literature for each of these steps, the formulation of best practices, and the submission of the draft document to peer review. FINDINGS: Eliminating unnecessary injections is the highest priority in preventing injection-associated infections. However, when intradermal, subcutaneous, or intramuscular injections are medically indicated, best infection control practices include the use of sterile injection equipment, the prevention of contamination of injection equipment and medication, the prevention of needle-stick injuries to the provider, and the prevention of access to used needles. CONCLUSION: The availability of best infection control practices for intradermal, subcutaneous, and intramuscular injections will provide a reference for global efforts to achieve the goal of safe and appropriate use of injections. WHO will revise the best practices five years after initial development, i.e. in 2005. PMID:12973641

Timing paradox of stepping and falls in ageing: not so quick and quick(er) on the trigger.

PubMed

Rogers, Mark W; Mille, Marie-Laure

2016-08-15

Physiological and degenerative changes affecting human standing balance are major contributors to falls with ageing. During imbalance, stepping is a powerful protective action for preserving balance that may be voluntarily initiated in recognition of a balance threat, or be induced by an externally imposed mechanical or sensory perturbation. Paradoxically, with ageing and falls, initiation slowing of voluntary stepping is observed together with perturbation-induced steps that are triggered as fast as or faster than for younger adults. While age-associated changes in sensorimotor conduction, central neuronal processing and cognitive functions are linked to delayed voluntary stepping, alterations in the coupling of posture and locomotion may also prolong step triggering. It is less clear, however, how these factors may explain the accelerated triggering of induced stepping. We present a conceptual model that addresses this issue. For voluntary stepping, a disruption in the normal coupling between posture and locomotion may underlie step-triggering delays through suppression of the locomotion network based on an estimation of the evolving mechanical state conditions for stability. During induced stepping, accelerated step initiation may represent an event-triggering process whereby stepping is released according to the occurrence of a perturbation rather than to the specific sensorimotor information reflecting the evolving instability. In this case, errors in the parametric control of induced stepping and its effectiveness in stabilizing balance would be likely to occur. We further suggest that there is a residual adaptive capacity with ageing that could be exploited to improve paradoxical triggering and other changes in protective stepping to impact fall risk. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Resuscitator’s perceptions and time for corrective ventilation steps during neonatal resuscitation☆

PubMed Central

Sharma, Vinay; Lakshminrusimha, Satyan; Carrion, Vivien; Mathew, Bobby

2016-01-01

Background The 2010 neonatal resuscitation program (NRP) guidelines incorporate ventilation corrective steps (using the mnemonic – MRSOPA) into the resuscitation algorithm. The perception of neonatal providers, time taken to perform these maneuvers or the effectiveness of these additional steps has not been evaluated. Methods Using two simulated clinical scenarios of varying degrees of cardiovascular compromise –perinatal asphyxia with (i) bradycardia (heart rate – 40 min−1) and (ii) cardiac arrest, 35 NRP certified providers were evaluated for preference to performing these corrective measures, the time taken for performing these steps and time to onset of chest compressions. Results The average time taken to perform ventilation corrective steps (MRSOPA) was 48.9 ± 21.4 s. Providers were less likely to perform corrective steps and proceed directly to endotracheal intubation in the scenario of cardiac arrest as compared to a state of bradycardia. Cardiac compressions were initiated significantly sooner in the scenario of cardiac arrest 89 ± 24 s as compared to severe bradycardia 122 ± 23 s, p < 0.0001. There were no differences in the time taken to initiation of chest compressions between physicians or mid-level care providers or with the level of experience of the provider. Conclusions Effective ventilation of the lungs with corrective steps using a mask is important in most cases of neonatal resuscitation. Neonatal resuscitators prefer early endotracheal intubation and initiation of chest compressions in the presence of asystolic cardiac arrest. Corrective ventilation steps can potentially postpone initiation of chest compressions and may delay return of spontaneous circulation in the presence of severe cardiovascular compromise. PMID:25796996

The critical steps for successful research: The research proposal and scientific writing: (A report on the pre-conference workshop held in conjunction with the 64th annual conference of the Indian Pharmaceutical Congress-2012)

PubMed Central

Balakumar, Pitchai; Inamdar, Mohammed Naseeruddin; Jagadeesh, Gowraganahalli

2013-01-01

An interactive workshop on ‘The Critical Steps for Successful Research: The Research Proposal and Scientific Writing’ was conducted in conjunction with the 64th Annual Conference of the Indian Pharmaceutical Congress-2012 at Chennai, India. In essence, research is performed to enlighten our understanding of a contemporary issue relevant to the needs of society. To accomplish this, a researcher begins search for a novel topic based on purpose, creativity, critical thinking, and logic. This leads to the fundamental pieces of the research endeavor: Question, objective, hypothesis, experimental tools to test the hypothesis, methodology, and data analysis. When correctly performed, research should produce new knowledge. The four cornerstones of good research are the well-formulated protocol or proposal that is well executed, analyzed, discussed and concluded. This recent workshop educated researchers in the critical steps involved in the development of a scientific idea to its successful execution and eventual publication. PMID:23761709

Progress Report on the US Critical Zone Observatory Program

NASA Astrophysics Data System (ADS)

Barrera, E. C.

2014-12-01

The Critical Zone Observatory (CZO) program supported by the National Science Foundation originated from the recommendation of the Earth Science community published in the National Research Council report "Basic Research Opportunities in Earth Sciences" (2001) to establish natural laboratories to study processes and systems of the Critical Zone - the surface and near-surface environment sustaining nearly all terrestrial life. After a number of critical zone community workshops to develop a science plan, the CZO program was initiated in 2007 with three sites and has now grown to 10 sites and a National Office, which coordinates research, education and outreach activities of the network. Several of the CZO sites are collocated with sites supported by the US Long Term Ecological Research (LTER) and the Long Term Agricultural Research (LTAR) programs, and the National Ecological Observatory Network (NEON). Future collaboration with additional sites of these networks will add to the potential to answer questions in a more comprehensive manner and in a larger regional scale about the critical zone form and function. At the international level, CZOs have been established in many countries and strong collaborations with the US program have been in place for many years. The next step is the development of a coordinated international program of critical zone research. The success of the CZO network of sites can be measured in transformative results that elucidate properties and processes controlling the critical zone and how the critical zone structure, stores and fluxes respond to climate and land use change. This understanding of the critical zone can be used to enhance resilience and sustainability, and restore ecosystem function. Thus, CZO science can address major societal challenges. The US CZO network is a facility open to research of the critical zone community at large. Scientific data and information about the US program are available at www.criticalzone.org.

Initiation structure of oblique detonation waves behind conical shocks

NASA Astrophysics Data System (ADS)

Yang, Pengfei; Ng, Hoi Dick; Teng, Honghui; Jiang, Zonglin

2017-08-01

The understanding of oblique detonation dynamics has both inherent basic research value for high-speed compressible reacting flow and propulsion application in hypersonic aerospace systems. In this study, the oblique detonation structures formed by semi-infinite cones are investigated numerically by solving the unsteady, two-dimensional axisymmetric Euler equations with a one-step irreversible Arrhenius reaction model. The present simulation results show that a novel wave structure, featured by two distinct points where there is close-coupling between the shock and combustion front, is depicted when either the cone angle or incident Mach number is reduced. This structure is analyzed by examining the variation of the reaction length scale and comparing the flow field with that of planar, wedge-induced oblique detonations. Further simulations are performed to study the effects of chemical length scale and activation energy, which are both found to influence the formation of this novel structure. The initiation mechanism behind the conical shock is discussed to investigate the interplay between the effect of the Taylor-Maccoll flow, front curvature, and energy releases from the chemical reaction in conical oblique detonations. The observed flow fields are interpreted by means of the energetic limit as in the critical regime for initiation of detonation.

Investigating Initial Disclosures and Reactions to Unexpected, Positive HPV Diagnosis.

PubMed

Smith, Rachel A; Hernandez, Rachael; Catona, Danielle

2014-07-01

Initial disclosures of health conditions are critical communication moments. Existing research focuses on disclosers; integrating confidants into studies of initial disclosures is needed. Guided by the disclosure decision-making model (DD-MM; Greene, 2009), this study examined what diagnosed persons and confidants may say when faced with unexpected test results and unexpected disclosures, respectively. Participants ( N = 151) recorded an audio-visual message for another person, after imagining that they or the other person had just received unexpected, positive HPV test results. The qualitative analysis revealed four themes: (1) impression management and social distance, (2) invisible symptoms and advice regarding future disclosures, (3) expressing and acknowledging emotional reactions, and (4) misunderstandings and lacking knowledge about HPV. These findings suggested that DD-MM may be a relevant framework for understanding not only when disclosers share, but what disclosers and confidants say in early conversations about new diagnoses. While disclosers' and confidants' messages showed marked similarities, important differences appeared. For example, confidants focused on assuaging disclosers' fear about the consequences, whereas disclosers expressed distress related to their uncertainty about the prognosis of an HPV infection and how to prepare for next steps. The discussion highlighted implications for the DD-MM, HPV disclosures, and future interventions.

Exploring the Process of Implementing Healthy Workplace Initiatives: Mapping to Kotter's Leading Change Model.

PubMed

Chappell, Stacie; Pescud, Melanie; Waterworth, Pippa; Shilton, Trevor; Roche, Dee; Ledger, Melissa; Slevin, Terry; Rosenberg, Michael

2016-10-01

The aim of this study was to use Kotter's leading change model to explore the implementation of workplace health and wellbeing initiatives. Qualitative interviews were conducted with 31 workplace representatives with a healthy workplace initiative. None of the workplaces used a formal change management model when implementing their healthy workplace initiatives. Not all of the steps in Kotter model were considered necessary and the order of the steps was challenged. For example, interviewees perceived that communicating the vision, developing the vision, and creating a guiding coalition were integral parts of the process, although there was less emphasis on the importance of creating a sense of urgency and consolidating change. Although none of the workplaces reported using a formal organizational change model when implementing their healthy workplace initiatives, there did appear to be perceived merit in using the steps in Kotter's model.

Registered nurses' experiences of caring for pregnant and postpartum women in general hospital settings: a systematic review and meta-synthesis of qualitative data.

PubMed

Bayes, Sara; Ewens, Beverley

2017-03-01

To understand how nurses view and experience caring for pregnant and postpartum women in nonmaternity care settings. A degree of apprehension is perceived to exist among nurses in relation to caring for pregnant or postpartum women in nonmaternity care settings. The nature of nonmidwife nurses' concerns about caring for this group of women in these contexts, however, is not known. A six-step systematic approach was employed for this review. In Step 1, the research question was developed; Step 2 involved developing the inclusion criteria for articles; the literature search strategy was devised in Step 3; Step 4 comprised the conduct of the literature search and selection of articles for review; in Step 5, the critical appraisal of selected studies and synthesis of data was undertaken; interpretation of the findings occurred in Step 6. Following a process of elimination, the final number of articles retained for this review was three. Fifty-four Level 1 findings were extracted from these three articles which were subsequently collapsed into four Level 2 categories. Two Level 3 synthesised findings that characterise what is known about the topic of interest were then derived from these four Level two categories. Nurses are reportedly ill prepared for the experience of caring for pregnant and postpartum women in general care settings. A combination of a lack of education and a need to 'learn on the job' reportedly evokes stress, trauma and a sense of professional inadequacy. This review identifies lack of knowledge and of adequate supervision for nurses in this context, which in turn poses a clinical risk to pregnant and postpartum women in their care. Effective strategies to establish initial and ongoing collaborative education and clinical practice guidelines are required. © 2016 John Wiley & Sons Ltd.

Development of assessment instruments to measure critical thinking skills

NASA Astrophysics Data System (ADS)

Sumarni, W.; Supardi, K. I.; Widiarti, N.

2018-04-01

Assessment instruments that is commonly used in the school generally have not been orientated on critical thinking skills. The purpose of this research is to develop assessment instruments to measure critical thinking skills, to test validity, reliability, and practicality. This type of research is Research and Development. There are two stages on the preface step, which are field study and literacy study. On the development steps, there some parts, which are 1) instrument construction, 2) expert validity, 3) limited scale tryout and 4) narrow scale try-out. The developed assessment instrument are analysis essay and problem solving. Instruments were declared valid, reliable and practical.

Respiratory assessment in critical care units.

PubMed

Cox, C L; McGrath, A

1999-08-01

As healthcare delivery changes in critical care, nursing continues to extend its practice base. Nursing practice is expanding to incorporate skills once seen as the remit of the medical profession. Critical care nurses are equipping themselves with evidence-based knowledge and skills that can enhance the care they provide to their patients. Assessment of patients is a major role in nursing and, by expanding assessment techniques, nurses can ensure patients receive the care most appropriate to their needs. Nurses in critical care are well placed to perform a more detailed assessment which can help to focus nursing care. This article describes the step-by-step process of undertaking a full and comprehensive respiratory assessment in critical care settings. It identifies many of the problems that patients may have and the signs and symptoms that a nurse may not whilst undertaking the assessment and preparing to prescribe care.

Short bowel mucosal morphology, proliferation and inflammation at first and repeat STEP procedures.

PubMed

Mutanen, Annika; Barrett, Meredith; Feng, Yongjia; Lohi, Jouko; Rabah, Raja; Teitelbaum, Daniel H; Pakarinen, Mikko P

2018-04-17

Although serial transverse enteroplasty (STEP) improves function of dilated short bowel, a significant proportion of patients require repeat surgery. To address underlying reasons for unsuccessful STEP, we compared small intestinal mucosal characteristics between initial and repeat STEP procedures in children with short bowel syndrome (SBS). Fifteen SBS children, who underwent 13 first and 7 repeat STEP procedures with full thickness small bowel samples at median age 1.5 years (IQR 0.7-3.7) were included. The specimens were analyzed histologically for mucosal morphology, inflammation and muscular thickness. Mucosal proliferation and apoptosis was analyzed with MIB1 and Tunel immunohistochemistry. Median small bowel length increased 42% by initial STEP and 13% by repeat STEP (p=0.05), while enteral caloric intake increased from 6% to 36% (p=0.07) during 14 (12-42) months between the procedures. Abnormal mucosal inflammation was frequently observed both at initial (69%) and additional STEP (86%, p=0.52) surgery. Villus height, crypt depth, enterocyte proliferation and apoptosis as well as muscular thickness were comparable at first and repeat STEP (p>0.05 for all). Patients, who required repeat STEP tended to be younger (p=0.057) with less apoptotic crypt cells (p=0.031) at first STEP. Absence of ileocecal valve associated with increased intraepithelial leukocyte count and reduced crypt cell proliferation index (p<0.05 for both). No adaptive mucosal hyperplasia or muscular alterations occurred between first and repeat STEP. Persistent inflammation and lacking mucosal growth may contribute to continuing bowel dysfunction in SBS children, who require repeat STEP procedure, especially after removal of the ileocecal valve. Level IV, retrospective study. Copyright © 2018 Elsevier Inc. All rights reserved.

An aggregation-volume-bias Monte Carlo investigation on the condensation of a Lennard-Jones vapor below the triple point and crystal nucleation in cluster systems: an in-depth evaluation of the classical nucleation theory.

PubMed

Chen, Bin; Kim, Hyunmi; Keasler, Samuel J; Nellas, Ricky B

2008-04-03

The aggregation-volume-bias Monte Carlo based simulation technique, which has led to our recent success in vapor-liquid nucleation research, was extended to the study of crystal nucleation processes. In contrast to conventional bulk-phase techniques, this method deals with crystal nucleation events in cluster systems. This approach was applied to the crystal nucleation of Lennard-Jonesium under a wide range of undercooling conditions from 35% to 13% below the triple point. It was found that crystal nucleation in these model clusters proceeds initially via a vapor-liquid like aggregation followed by the formation of crystals inside the aggregates. The separation of these two stages of nucleation is distinct except at deeper undercooling conditions where the crystal nucleation barrier was found to diminish. The simulation results obtained for these two nucleation steps are separately compared to the classical nucleation theory (CNT). For the vapor-liquid nucleation step, the CNT was shown to provide a reasonable description of the critical cluster size but overestimate the barrier heights, consistent with previous simulation studies. On the contrary, for the crystal nucleation step, nearly perfect agreement with the barrier heights was found between the simulations and the CNT. For the critical cluster size, the comparison is more difficult as the simulation data were found to be sensitive to the definition of the solid cluster, but a stringent criterion and lower undercooling conditions generally lead to results closer with the CNT. Additional simulations at undercooling conditions of 40% or above indicate a nearly barrierless transition from the liquid to crystalline-like structure for sufficiently large clusters, which leads to further departure of the barrier height predicted by the CNT from the simulation data for the aggregation step. This is consistent with the latest experimental results on argon that show an unusually large underestimation of the nucleation rate by the CNT toward deep undercooling conditions.

Evaluating time dynamics of topographic threshold relations for gully initiation

NASA Astrophysics Data System (ADS)

Hayas, Antonio; Vanwalleghem, Tom; Poesen, Jean

2016-04-01

Gully erosion is one of the most important soil degradation processes at global scale. However, modelling of gully erosion is still difficult. Despite advances in the modelling of gully headcut rates and incision rates, it remains difficult to predict the location of gully initiation points and trajectories. In different studies it has been demonstrated that a good method of predicting gully initiation is by using a slope (S) - area (A) threshold. Such an S-A relation is a simple way of estimating the critical discharges needed to generate a critical shear stress that can incise a particular soil and initiate a gully. As such, the simple S-A threshold will vary if the rainfall-runoff behaviour of the soil changes or if the soil's erodibility changes. Over the past decades, important agronomic changes have produced significant changes in the soil use and soil management in SW Spain. It is the objective of this research to evaluate how S-A relations for gully initiation have changed over time and for two different land uses, cereal and olive. Data was collected for a gully network in the Cordoba Province, SW Spain. From photo-interpretation of historical air photos between 1956 and 2013, the gully network and initiation points were derived. In total 10 different time steps are available (1956; 1977; 1984; 1998; 2001; 2004; 2006; 2008; 2010; 2013). Topographical thresholds were extracted by combining the digitized gully network with the DEM. Due to small differences in the alignment of ortophotos and DEM, an optimization technique was developed in GIS to extract the correct S-A value for each point. With the S-A values for each year, their dynamics was evaluated as a function of land use (olive or cereal) and in function of the following variables in each of the periods considered: • soil management • soil cover by weeds, where weed growth was modeled from the daily soil water balance • rainfall intensity • root cohesion, , where root growth was modeled from the daily soil water balance We found important differences between cereal and olive and significant changes in the S-A relation over time.

On the Transition from Initial Leader to Stepped Leader in Negative Cloud-to-ground Lightning

NASA Astrophysics Data System (ADS)

Stolzenburg, M.; Marshall, T. C.; Karunarathne, S.; Orville, R. E.

2017-12-01

High-speed video and electric field change (E-change) data are used to describe the first 5 ms of a natural negative cloud-to-ground (CG) flash. These observations reveal differences in appearance of both the video luminosity and the E-change pulses before the leader transitions to propagating as a negative stepped leader (SL). During the initial breakdown (IB) stage, the initial leader advances intermittently forward in jumps of 78-175 m, at intervals of 100-280 μs, and in separate bursts that are bright for a few 20-μs video frames. The IB pulses accompanying these luminosity bursts have long duration, large amplitude, and a characteristic bipolar shape in nearby E-change observations. In the time between IB pulses, the initial leader is very dim or not visible during the earliest 1-2 ms of the IB stage. Over the next few milliseconds, the leader propagation transitions to an early SL phase, in which the leader tips advance 20-59 m forward at more regular intervals of 40-80 μs during relatively dim and brief steps. In the E-change data, the accompanying SL pulses have very short duration, small amplitude, and are typically unipolar. These data indicate that when the entire initial leader length behind the lower end begins to remain illuminated between bursts, the propagation mode changes from IB bursts to SL steps, and the IB stage ends. Additional differences in initial leader character are evident during the return stroke, as its luminosity speed decreases sharply upon reaching the topmost initial leader section of the channel, and that section of channel does not saturate the video intensity. Results of these analyses support a prior hypothesis that the early initial leader development occurs in the absence of a continuously hot channel, and consequently, the initial leader propagation is unlike the self-propagating advance of the later stepped leader.

Comparison of enamel bond fatigue durability of universal adhesives and two-step self-etch adhesives in self-etch mode.

PubMed

Tsujimoto, Akimasa; Barkmeier, Wayne W; Hosoya, Yumiko; Nojiri, Kie; Nagura, Yuko; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

2017-10-01

To comparatively evaluate universal adhesives and two-step self-etch adhesives for enamel bond fatigue durability in self-etch mode. Three universal adhesives (Clearfil Universal Bond; G-Premio Bond; Scotchbond Universal Adhesive) and three two-step self-etch adhesives (Clearfil SE Bond; Clearfil SE Bond 2; OptiBond XTR) were used. The initial shear bond strength and shear fatigue strength of the adhesive to enamel in self-etch mode were determined. The initial shear bond strengths of the universal adhesives to enamel in self-etch mode was significantly lower than those of two-step self-etch adhesives and initial shear bond strengths were not influenced by type of adhesive in each adhesive category. The shear fatigue strengths of universal adhesives to enamel in self-etch mode were significantly lower than that of Clearfil SE Bond and Clearfil SE Bond 2, but similar to that OptiBond XTR. Unlike two-step self-etch adhesives, the initial shear bond strength and shear fatigue strength of universal adhesives to enamel in self-etch mode was not influenced by the type of adhesive. This laboratory study showed that the enamel bond fatigue durability of universal adhesives was lower than Clearfil SE Bond and Clearfil SE Bond 2, similar to Optibond XTR, and was not influenced by type of adhesive, unlike two-step self-etch adhesives.

Central vein perforation during tunneled dialysis catheter insertion: principles of acute management.

PubMed

Pua, Uei

2014-10-01

Central venous perforation during dialysis catheter insertion is a potentially fatal complication. Prompt recognition and judicious initial steps are important in optimizing the outcome. The purpose of this manuscript is to illustrate the imaging features and steps in initial management. © 2014 International Society for Hemodialysis.

Using Mixed Methods to Assess Initiatives with Broad-Based Goals

ERIC Educational Resources Information Center

Inkelas, Karen Kurotsuchi

2017-01-01

This chapter describes a process for assessing programmatic initiatives with broad-ranging goals with the use of a mixed-methods design. Using an example of a day-long teaching development conference, this chapter provides practitioners step-by-step guidance on how to implement this assessment process.

Automatic initial and final segmentation in cleft palate speech of Mandarin speakers

PubMed Central

Liu, Yin; Yin, Heng; Zhang, Junpeng; Zhang, Jing; Zhang, Jiang

2017-01-01

The speech unit segmentation is an important pre-processing step in the analysis of cleft palate speech. In Mandarin, one syllable is composed of two parts: initial and final. In cleft palate speech, the resonance disorders occur at the finals and the voiced initials, while the articulation disorders occur at the unvoiced initials. Thus, the initials and finals are the minimum speech units, which could reflect the characteristics of cleft palate speech disorders. In this work, an automatic initial/final segmentation method is proposed. It is an important preprocessing step in cleft palate speech signal processing. The tested cleft palate speech utterances are collected from the Cleft Palate Speech Treatment Center in the Hospital of Stomatology, Sichuan University, which has the largest cleft palate patients in China. The cleft palate speech data includes 824 speech segments, and the control samples contain 228 speech segments. The syllables are extracted from the speech utterances firstly. The proposed syllable extraction method avoids the training stage, and achieves a good performance for both voiced and unvoiced speech. Then, the syllables are classified into with “quasi-unvoiced” or with “quasi-voiced” initials. Respective initial/final segmentation methods are proposed to these two types of syllables. Moreover, a two-step segmentation method is proposed. The rough locations of syllable and initial/final boundaries are refined in the second segmentation step, in order to improve the robustness of segmentation accuracy. The experiments show that the initial/final segmentation accuracies for syllables with quasi-unvoiced initials are higher than quasi-voiced initials. For the cleft palate speech, the mean time error is 4.4ms for syllables with quasi-unvoiced initials, and 25.7ms for syllables with quasi-voiced initials, and the correct segmentation accuracy P30 for all the syllables is 91.69%. For the control samples, P30 for all the syllables is 91.24%. PMID:28926572

Automatic initial and final segmentation in cleft palate speech of Mandarin speakers.

PubMed

He, Ling; Liu, Yin; Yin, Heng; Zhang, Junpeng; Zhang, Jing; Zhang, Jiang

2017-01-01

The speech unit segmentation is an important pre-processing step in the analysis of cleft palate speech. In Mandarin, one syllable is composed of two parts: initial and final. In cleft palate speech, the resonance disorders occur at the finals and the voiced initials, while the articulation disorders occur at the unvoiced initials. Thus, the initials and finals are the minimum speech units, which could reflect the characteristics of cleft palate speech disorders. In this work, an automatic initial/final segmentation method is proposed. It is an important preprocessing step in cleft palate speech signal processing. The tested cleft palate speech utterances are collected from the Cleft Palate Speech Treatment Center in the Hospital of Stomatology, Sichuan University, which has the largest cleft palate patients in China. The cleft palate speech data includes 824 speech segments, and the control samples contain 228 speech segments. The syllables are extracted from the speech utterances firstly. The proposed syllable extraction method avoids the training stage, and achieves a good performance for both voiced and unvoiced speech. Then, the syllables are classified into with "quasi-unvoiced" or with "quasi-voiced" initials. Respective initial/final segmentation methods are proposed to these two types of syllables. Moreover, a two-step segmentation method is proposed. The rough locations of syllable and initial/final boundaries are refined in the second segmentation step, in order to improve the robustness of segmentation accuracy. The experiments show that the initial/final segmentation accuracies for syllables with quasi-unvoiced initials are higher than quasi-voiced initials. For the cleft palate speech, the mean time error is 4.4ms for syllables with quasi-unvoiced initials, and 25.7ms for syllables with quasi-voiced initials, and the correct segmentation accuracy P30 for all the syllables is 91.69%. For the control samples, P30 for all the syllables is 91.24%.

Genuine participation in participant-centred research initiatives: the rhetoric and the potential reality.

PubMed

Feeney, Oliver; Borry, Pascal; Felzmann, Heike; Galvagni, Lucia; Haukkala, Ari; Loi, Michele; Nordal, Salvör; Rakic, Vojin; Riso, Brígida; Sterckx, Sigrid; Vears, Danya

2018-04-01

The introduction of Web 2.0 technology, along with a population increasingly proficient in Information and Communications Technology (ICT), coupled with the rapid advancements in genetic testing methods, has seen an increase in the presence of participant-centred research initiatives. Such initiatives, aided by the centrality of ICT interconnections, and the ethos they propound seem to further embody the ideal of increasing the participatory nature of research, beyond what might be possible in non-ICT contexts alone. However, the majority of such research seems to actualise a much narrower definition of 'participation'-where it is merely the case that such research initiatives have increased contact with participants through ICT but are otherwise non-participatory in any important normative sense. Furthermore, the rhetoric of participant-centred initiatives tends to inflate this minimalist form of participation into something that it is not, i.e. something genuinely participatory, with greater connections with both the ICT-facilitated political contexts and the largely non-ICT participatory initiatives that have expanded in contemporary health and research contexts. In this paper, we highlight that genuine (ICT-based) 'participation' should enable a reasonable minimum threshold of participatory engagement through, at least, three central participatory elements: educative, sense of being involved and degree of control. While we agree with criticisms that, at present, genuine participation seems more rhetoric than reality, we believe that there is clear potential for a greater ICT-facilitated participatory engagement on all three participatory elements. We outline some practical steps such initiatives could take to further develop these elements and thereby their level of ICT-facilitated participatory engagement.

Simulation trainer for practicing emergent open thoracotomy procedures.

PubMed

Hamilton, Allan J; Prescher, Hannes; Biffar, David E; Poston, Robert S

2015-07-01

An emergent open thoracotomy (OT) is a high-risk, low-frequency procedure uniquely suited for simulation training. We developed a cost-effective Cardiothoracic (CT) Surgery trainer and assessed its potential for improving technical and interprofessional skills during an emergent simulated OT. We modified a commercially available mannequin torso with artificial tissue models to create a custom CT Surgery trainer. The trainer's feasibility for simulating emergent OT was tested using a multidisciplinary CT team in three consecutive in situ simulations. Five discretely observable milestones were identified as requisite steps in carrying out an emergent OT; namely (1) diagnosis and declaration of a code situation, (2) arrival of the code cart, (3) arrival of the thoracotomy tray, (4) initiation of the thoracotomy incision, and (5) defibrillation of a simulated heart. The time required for a team to achieve each discrete step was measured by an independent observer over the course of each OT simulation trial and compared. Over the course of the three OT simulation trials conducted in the coronary care unit, there was an average reduction of 29.5% (P < 0.05) in the times required to achieve the five critical milestones. The time required to complete the whole OT procedure improved by 7 min and 31 s from the initial to the final trial-an overall improvement of 40%. In our preliminary evaluation, the CT Surgery trainer appears to be useful for improving team performance during a simulated emergent bedside OT in the coronary care unit. Copyright © 2015 Elsevier Inc. All rights reserved.

Step-Initiation Deficits in Children with Faulty Posture Diagnosed with Neurodevelopmental Disorders during Infancy.

PubMed

Stania, Magdalena; Sarat-Spek, Alina; Blacha, Teresa; Kazek, Beata; Słomka, Kajetan J; Emich-Widera, Ewa; Juras, Grzegorz

2017-01-01

Early detection of movement deficits during step initiation will facilitate the selection of the optimal physiotherapy management strategy. The main aim of the study was to assess potential differences in step initiation between 5- and 6-year-old children with faulty posture who had been diagnosed with neurodevelopmental disorders during infancy and healthy children. The experimental group consisted of 19 children aged 5-6 years with faulty posture, who had been diagnosed with neurodevelopmental disorders during infancy and were given physiotherapy in the first year of their lives. The control group comprised 19 nursery school children aged 5-6 years with no postural defects, no history of postural control or movement deficits, and no physiotherapy interventions in the first year of their lives. Step initiation was performed on force platforms under various conditions, i.e., with and without an obstacle, stepping up onto a platform placed at a higher level, stepping down onto a platform placed on a lower level. The recording of center of foot pressure (COP) displacements was divided into three phases: phase 1 (P1)-quiet standing before step initiation, phase 2 (P2)-transit, phase 3 (P3)-quiet standing until measurement completion. The Tukey post hoc test showed that the means of sway range (raCOP) and mean velocity (vCOP) in sagittal ( AP ) plane for phase 1 and vCOP in frontal ( ML ) plane for phase 3 registered in the step-up trial were significantly higher ( p  < 0.05) in children with faulty posture compared to children with typical development. P1vCOP ML , P3vCOP AP , P3raCOP ML , and P3vCOP ML of the step-down trial were also significantly higher in children with faulty posture ( p  < 0.05). Inclusion of functional movement exercises (stair-walking tasks) in physiotherapy interventions for children with postural defects seems well justified.The trial was registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12617001068358).

Phase Variable O Antigen Biosynthetic Genes Control Expression of the Major Protective Antigen and Bacteriophage Receptor in Vibrio cholerae O1

PubMed Central

Seed, Kimberley D.; Faruque, Shah M.; Mekalanos, John J.; Calderwood, Stephen B.; Qadri, Firdausi; Camilli, Andrew

2012-01-01

The Vibrio cholerae lipopolysaccharide O1 antigen is a major target of bacteriophages and the human immune system and is of critical importance for vaccine design. We used an O1-specific lytic bacteriophage as a tool to probe the capacity of V. cholerae to alter its O1 antigen and identified a novel mechanism by which this organism can modulate O antigen expression and exhibit intra-strain heterogeneity. We identified two phase variable genes required for O1 antigen biosynthesis, manA and wbeL. manA resides outside of the previously recognized O1 antigen biosynthetic locus, and encodes for a phosphomannose isomerase critical for the initial step in O1 antigen biosynthesis. We determined that manA and wbeL phase variants are attenuated for virulence, providing functional evidence to further support the critical role of the O1 antigen for infectivity. We provide the first report of phase variation modulating O1 antigen expression in V. cholerae, and show that the maintenance of these phase variable loci is an important means by which this facultative pathogen can generate the diverse subpopulations of cells needed for infecting the host intestinal tract and for escaping predation by an O1-specific phage. PMID:23028317

New theory for Mode I crack-tip dislocation emission

NASA Astrophysics Data System (ADS)

Andric, Predrag; Curtin, W. A.

2017-09-01

A material is intrinsically ductile under Mode I loading when the critical stress intensity KIe for dislocation emission is lower than the critical stress intensity KIc for cleavage. KIe is usually evaluated using the approximate Rice theory, which predicts a dependence on the elastic constants and the unstable stacking fault energy γusf for slip along the plane of dislocation emission. Here, atomistic simulations across a wide range of fcc metals show that KIe is systematically larger (10-30%) than predicted. However, the critical (crack tip) shear displacement is up to 40% smaller than predicted. The discrepancy arises because Mode I emission is accompanied by the formation of a surface step that is not considered in the Rice theory. A new theory for Mode I emission is presented based on the ideas that (i) the stress resisting step formation at the crack tip creates "lattice trapping" against dislocation emission such that (ii) emission is due to a mechanical instability at the crack tip. The new theory is formulated using a Peierls-type model, naturally includes the energy to form the step, and reduces to the Rice theory (no trapping) when the step energy is small. The new theory predicts a higher KIe at a smaller critical shear displacement, rationalizing deviations of simulations from the Rice theory. Specific predictions of KIe for the simulated materials, usually requiring use of the measured critical crack tip shear displacement due to complex material non-linearity, show very good agreement with simulations. An analytic model involving only γusf, the surface energy γs, and anisotropic elastic constants is shown to be quite accurate, serves as a replacement for the analytical Rice theory, and is used to understand differences between Rice theory and simulation in recent literature. The new theory highlights the role of surface steps created by dislocation emission in Mode I, which has implications not only for intrinsic ductility but also for crack tip twinning and fracture due to chemical interactions at the crack tip.

Pediatricians Transitioning Practices, Youth With Special Health Care Needs in New York State.

PubMed

Davidson, Lynn F; Chhabra, Rosy; Cohen, Hillel W; Lechuga, Claudia; Diaz, Patricia; Racine, Andrew

2015-10-01

To assess current practices of New York State pediatricians as they transition youth with special health care needs to adult-oriented medical care. A survey of New York State pediatricians included 6 critical steps from 2002 consensus statement, 11 essential steps adapted from recent literature, and questions targeting age of starting transition and availability of transition policy. Of 181 respondents, only 11% have a transition policy. Most assist patients in transition process; identify an adult provider (92%); and create portable medical summary (57%). Only 3% start planning process at recommended age. No respondents are compliant with all 6 critical steps; subspecialists were more likely to report compliance to more than 4 steps. Participating pediatricians are making gains, yet effort is needed, to incorporate the essential steps into practice for transitioning youth with special health care needs. Recognition of barriers, use of electronic tools, and clarifying subspecialist's approach, may improve compliance with transition recommendations. © The Author(s) 2015.

Nogo Receptor 1 Confines a Disinhibitory Microcircuit to the Critical Period in Visual Cortex.

PubMed

Stephany, Céleste-Élise; Ikrar, Taruna; Nguyen, Collins; Xu, Xiangmin; McGee, Aaron W

2016-10-26

A characteristic of the developing mammalian visual system is a brief interval of plasticity, termed the "critical period," when the circuitry of primary visual cortex is most sensitive to perturbation of visual experience. Depriving one eye of vision (monocular deprivation [MD]) during the critical period alters ocular dominance (OD) by shifting the responsiveness of neurons in visual cortex to favor the nondeprived eye. A disinhibitory microcircuit involving parvalbumin-expressing (PV) interneurons initiates this OD plasticity. The gene encoding the neuronal nogo-66-receptor 1 (ngr1/rtn4r) is required to close the critical period. Here we combined mouse genetics, electrophysiology, and circuit mapping with laser-scanning photostimulation to investigate whether disinhibition is confined to the critical period by ngr1 We demonstrate that ngr1 mutant mice retain plasticity characteristic of the critical period as adults, and that ngr1 operates within PV interneurons to restrict the loss of intracortical excitatory synaptic input following MD in adult mice, and this disinhibition induces a "lower PV network configuration" in both critical-period wild-type mice and adult ngr1 -/- mice. We propose that ngr1 limits disinhibition to close the critical period for OD plasticity and that a decrease in PV expression levels reports the diminished recent cumulative activity of these interneurons. Life experience refines brain circuits throughout development during specified critical periods. Abnormal experience during these critical periods can yield enduring maladaptive changes in neural circuits that impair brain function. In the developing visual system, visual deprivation early in life can result in amblyopia (lazy-eye), a prevalent childhood disorder comprising permanent deficits in spatial vision. Here we identify that the nogo-66 receptor 1 gene restricts an early and essential step in OD plasticity to the critical period. These findings link the emerging circuit-level description of OD plasticity to the genetic regulation of the critical period. Understanding how plasticity is confined to critical periods may provide clues how to better treat amblyopia. Copyright © 2016 the authors 0270-6474/16/3611006-07$15.00/0.

Global action to reduce HIV stigma and discrimination

PubMed Central

Grossman, Cynthia I; Stangl, Anne L

2013-01-01

There is no question that the stigma and discrimination associated with HIV and AIDS can be reduced through intervention. The inclusion of stigma and discrimination reduction as a critical component of achieving an AIDS-free generation in recent UNAIDS, UN and PEPFAR political initiatives is promising. Yet national governments need evidence on effective interventions at the individual, community and societal levels in order to strategically incorporate stigma and discrimination reduction into national AIDS plans. Currently, the heterogeneity of stigma and discrimination reduction approaches and measurement makes it challenging to compare and contrast evaluated interventions. Moving forward, it is critical for the research community to: (1) clearly link intervention activities to the domains of stigma to be shifted; (2) assess the stigma domains in a consistent manner; and (3) link stigma and discrimination reduction with HIV prevention, care and treatment outcomes (e.g., uptake, adherence and retention of ART). These steps would further advance the scientific evidence base of stigma and discrimination reduction and allow for the identification of effective interventions that could be scaled up by national governments. PMID:24242269

Mission to Planet Earth Strategic Enterprise Plan 1996-2002

NASA Technical Reports Server (NTRS)

1996-01-01

Mission to Planet Earth's (MTPE's) first Strategic Enterprise Plan, issued in May 1995, defined the Agency's major goals and objectives as well as constraints. This update of the Strategic Enterprise Plan identifies the following major changes: a focused Science Research Plan that integrates space-based and in situ observational critical science to address critical science uncertainties; a technology infusion plan to reduce the cost of future missions; a series of flight opportunities to infuse new science into the overall program; and a tighter coupling between NASA and NOAA to reduce costs and to improve the overall program. Three important new initiatives are also under development and are described briefly in this plan: MTPE Education Strategy, MTPE Commercial Strategy, and an emerging concept for an Integrated Global Observing Strategy. This first update to the MTPE Strategic Enterprise Plan captures these new developments, and takes a significant step forward in planning this complex Earth system science endeavor. The plan and other information on MTPE may be viewed via the Internet at http://www.hq.nasa.gov/office/mtpe/.

Perceptions of strengths and deficiencies: Disconnects between graduate students and prospective employers

USGS Publications Warehouse

Sundberg, M.D.; Deangelis, P.; Havens, K.; Holsinger, K.; Kennedy, K.; Kramer, A.T.; Muir, R.; Olwell, P.; Schierenbeck, K.; Stritch, L.; Zorn-Arnold, B.

2011-01-01

The US Botanical Capacity Assessment Project (BCAP) was initiated as a first step to gauge the nation's collective ability to meet the environmental challenges of the 21st century. The project, in which the authors of this article are involved, specifically aimed to identify multisector contributions to and gaps in botanical capacity in order to develop growth opportunities to address research and management problems. One of the primary gaps revealed by the BCAP surveys was that the skills graduate students identified as their greatest strengths closely matched the areas future employers (government and private sectors) identified as needing greatest improvement. Although our survey focused on only one discipline (botany), we suspect that the results are applicable throughout the science, technology, engineering, and mathematics disciplines. We suggest that it is critical for university faculty and administrators to team with professionals from government, nonprofit, and for-profit organizations to identify critical and desired knowledge and skill sets and implement the necessary curriculum changes to provide graduates with the tools they need. ?? 2011 by American Institute of Biological Sciences. All rights reserved.

Editorial: Global action to reduce HIV stigma and discrimination.

PubMed

Grossman, Cynthia I; Stangl, Anne L

2013-11-13

There is no question that the stigma and discrimination associated with HIV and AIDS can be reduced through intervention. The inclusion of stigma and discrimination reduction as a critical component of achieving an AIDS-free generation in recent UNAIDS, UN and PEPFAR political initiatives is promising. Yet national governments need evidence on effective interventions at the individual, community and societal levels in order to strategically incorporate stigma and discrimination reduction into national AIDS plans. Currently, the heterogeneity of stigma and discrimination reduction approaches and measurement makes it challenging to compare and contrast evaluated interventions. Moving forward, it is critical for the research community to: (1) clearly link intervention activities to the domains of stigma to be shifted; (2) assess the stigma domains in a consistent manner; and (3) link stigma and discrimination reduction with HIV prevention, care and treatment outcomes (e.g., uptake, adherence and retention of ART). These steps would further advance the scientific evidence base of stigma and discrimination reduction and allow for the identification of effective interventions that could be scaled up by national governments.

Conformational dynamics underlie the activity of the auxin-binding protein, Nt-abp1.

PubMed

David, K; Carnero-Diaz, E; Leblanc, N; Monestiez, M; Grosclaude, J; Perrot-Rechenmann, C

2001-09-14

The auxin-binding protein 1 (ABP1) has been proposed to be involved in the perception of the phytohormone at the plasma membrane. Site-directed mutagenesis was performed on highly conserved residues at the C terminus of ABP1 to investigate their relative importance in protein folding and activation of a functional response at the plasma membrane. Detailed analysis of the dynamic interaction of the wild-type ABP1 and mutated proteins with three distinct monoclonal antibodies recognizing conformation-dependent epitopes was performed by surface plasmon resonance. The influence of auxin on these interactions was also investigated. The Cys(177) as well as Asp(175) and Glu(176) were identified as critical residues for ABP1 folding and action at the plasma membrane. On the contrary, the C-terminal KDEL sequence was demonstrated not to be essential for auxin binding, interaction with the plasma membrane, or activation of the transduction cascade although it does appear to be involved in the stability of ABP1. Taken together, the results confirmed that ABP1 conformational change is the critical step for initiating the signal from the plasma membrane.

Critical Steps in Data Analysis for Precision Casimir Force Measurements with Semiconducting Films

NASA Astrophysics Data System (ADS)

Banishev, A. A.; Chang, Chia-Cheng; Mohideen, U.

2011-06-01

Some experimental procedures and corresponding results of the precision measurement of the Casimir force between low doped Indium Tin Oxide (ITO) film and gold sphere are described. Measurements were performed using an Atomic Force Microscope in high vacuum. It is shown that the magnitude of the Casimir force decreases after prolonged UV treatment of the ITO film. Some critical data analysis steps such as the correction for the mechanical drift of the sphere-plate system and photodiodes are discussed.

Critical Steps in Data Analysis for Precision Casimir Force Measurements with Semiconducting Films

NASA Astrophysics Data System (ADS)

Banishev, A. A.; Chang, Chia-Cheng; Mohideen, U.

Some experimental procedures and corresponding results of the precision measurement of the Casimir force between low doped Indium Tin Oxide (ITO) film and gold sphere are described. Measurements were performed using an Atomic Force Microscope in high vacuum. It is shown that the magnitude of the Casimir force decreases after prolonged UV treatment of the ITO film. Some critical data analysis steps such as the correction for the mechanical drift of the sphere-plate system and photodiodes are discussed.

Formal Methods for Life-Critical Software

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Johnson, Sally C.

1993-01-01

The use of computer software in life-critical applications, such as for civil air transports, demands the use of rigorous formal mathematical verification procedures. This paper demonstrates how to apply formal methods to the development and verification of software by leading the reader step-by-step through requirements analysis, design, implementation, and verification of an electronic phone book application. The current maturity and limitations of formal methods tools and techniques are then discussed, and a number of examples of the successful use of formal methods by industry are cited.

Using discharge data to reduce structural deficits in a hydrological model with a Bayesian inference approach and the implications for the prediction of critical source areas

NASA Astrophysics Data System (ADS)

Frey, M. P.; Stamm, C.; Schneider, M. K.; Reichert, P.

2011-12-01

A distributed hydrological model was used to simulate the distribution of fast runoff formation as a proxy for critical source areas for herbicide pollution in a small agricultural catchment in Switzerland. We tested to what degree predictions based on prior knowledge without local measurements could be improved upon relying on observed discharge. This learning process consisted of five steps: For the prior prediction (step 1), knowledge of the model parameters was coarse and predictions were fairly uncertain. In the second step, discharge data were used to update the prior parameter distribution. Effects of uncertainty in input data and model structure were accounted for by an autoregressive error model. This step decreased the width of the marginal distributions of parameters describing the lower boundary (percolation rates) but hardly affected soil hydraulic parameters. Residual analysis (step 3) revealed model structure deficits. We modified the model, and in the subsequent Bayesian updating (step 4) the widths of the posterior marginal distributions were reduced for most parameters compared to those of the prior. This incremental procedure led to a strong reduction in the uncertainty of the spatial prediction. Thus, despite only using spatially integrated data (discharge), the spatially distributed effect of the improved model structure can be expected to improve the spatially distributed predictions also. The fifth step consisted of a test with independent spatial data on herbicide losses and revealed ambiguous results. The comparison depended critically on the ratio of event to preevent water that was discharged. This ratio cannot be estimated from hydrological data only. The results demonstrate that the value of local data is strongly dependent on a correct model structure. An iterative procedure of Bayesian updating, model testing, and model modification is suggested.

Development of a Rubric to Improve Critical Thinking

ERIC Educational Resources Information Center

Hildenbrand, Kasee J.; Schultz, Judy A.

2012-01-01

Context: Health care professionals, including athletic trainers are confronted daily with multiple complex problems that require critical thinking. Objective: This research attempts to develop a reliable process to assess students' critical thinking in a variety of athletic training and kinesiology courses. Design: Our first step was to create a…

Comprehensive Nuclear-Test-Ban Treaty: Issues and Arguments

DTIC Science & Technology

2008-03-12

further fissions. “ Criticality ” is the point at which this chain reaction occurs; a “ critical mass ” is the amount of fissile material just enough to...support criticality . The amount of material for a critical mass depends on many factors, such as shape, density, impurities that absorb neutrons, and use...less than a critical mass of fissile material; as the amount of this material was stepped up toward criticality from one experiment to the next, some of

Characteristics and adaptive strategies linked with falls in stroke survivors from analysis of laboratory-induced falls

PubMed Central

Honeycutt, Claire F.; Nevisipour, Masood; Grabiner, Mark D.

2016-01-01

Falls are the most common and expensive medical complication in stroke survivors. There is remarkably little information about what factors lead to a fall in stroke survivors. With few exceptions, the falls literature in stroke has focused on relating metrics of static balance and impairment to fall outcomes in the acute care setting or in community. While informative, these studies provide little information about what specific impairments in a stroke-survivor’s response to dynamic balance challenges lead to a fall. We identified the key kinematic characteristics of stroke survivors’ stepping responses following a balance disturbance that are associated with a fall following dynamic balance challenges. Stroke survivors were exposed to posteriorly-directed translations of a treadmill belt that elicited a stepping response. Kinematics were compared between successful and failed recovery attempts (i.e. a fall). We found that the ability to arrest and reverse trunk flexion and the ability to perform an appropriate initial compensatory step were the most critical response contributors to a successful recovery. We also identified 2 compensatory strategies utilized by stroke survivors to avoid a fall. Despite significant post-stroke functional impairments, the biomechanical causes of trip-related falls by stroke survivors appear to be similar to those of unimpaired older adults and lower extremity amputees. However, compensatory strategies (pivot, hopping) were observed. PMID:27614614

Application of a quality by design approach to the cell culture process of monoclonal antibody production, resulting in the establishment of a design space.

PubMed

Nagashima, Hiroaki; Watari, Akiko; Shinoda, Yasuharu; Okamoto, Hiroshi; Takuma, Shinya

2013-12-01

This case study describes the application of Quality by Design elements to the process of culturing Chinese hamster ovary cells in the production of a monoclonal antibody. All steps in the cell culture process and all process parameters in each step were identified by using a cause-and-effect diagram. Prospective risk assessment using failure mode and effects analysis identified the following four potential critical process parameters in the production culture step: initial viable cell density, culture duration, pH, and temperature. These parameters and lot-to-lot variability in raw material were then evaluated by process characterization utilizing a design of experiments approach consisting of a face-centered central composite design integrated with a full factorial design. Process characterization was conducted using a scaled down model that had been qualified by comparison with large-scale production data. Multivariate regression analysis was used to establish statistical prediction models for performance indicators and quality attributes; with these, we constructed contour plots and conducted Monte Carlo simulation to clarify the design space. The statistical analyses, especially for raw materials, identified set point values, which were most robust with respect to the lot-to-lot variability of raw materials while keeping the product quality within the acceptance criteria. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

The 12 Steps of Addiction Recovery Programs as an Influence on Leadership Development: A Personal Narrative

ERIC Educational Resources Information Center

Friedman, Mitchell

2016-01-01

My participation in a 12-step addiction program based on the principles and traditions of Alcoholics Anonymous (AA) has been critical for my leadership development. As I worked to refrain from addictive behaviors and practiced 12-step principles, I experienced a shift from individualistic, self-centered leadership towards a servant leader…

A review for identification of initiating events in event tree development process on nuclear power plants

NASA Astrophysics Data System (ADS)

Riyadi, Eko H.

2014-09-01

Initiating event is defined as any event either internal or external to the nuclear power plants (NPPs) that perturbs the steady state operation of the plant, if operating, thereby initiating an abnormal event such as transient or loss of coolant accident (LOCA) within the NPPs. These initiating events trigger sequences of events that challenge plant control and safety systems whose failure could potentially lead to core damage or large early release. Selection for initiating events consists of two steps i.e. first step, definition of possible events, such as by evaluating a comprehensive engineering, and by constructing a top level logic model. Then the second step, grouping of identified initiating event's by the safety function to be performed or combinations of systems responses. Therefore, the purpose of this paper is to discuss initiating events identification in event tree development process and to reviews other probabilistic safety assessments (PSA). The identification of initiating events also involves the past operating experience, review of other PSA, failure mode and effect analysis (FMEA), feedback from system modeling, and master logic diagram (special type of fault tree). By using the method of study for the condition of the traditional US PSA categorization in detail, could be obtained the important initiating events that are categorized into LOCA, transients and external events.

Managing pregnancy of unknown location based on initial serum progesterone and serial serum hCG levels: development and validation of a two-step triage protocol.

PubMed

Van Calster, B; Bobdiwala, S; Guha, S; Van Hoorde, K; Al-Memar, M; Harvey, R; Farren, J; Kirk, E; Condous, G; Sur, S; Stalder, C; Timmerman, D; Bourne, T

2016-11-01

A uniform rationalized management protocol for pregnancies of unknown location (PUL) is lacking. We developed a two-step triage protocol to select PUL at high risk of ectopic pregnancy (EP), based on serum progesterone level at presentation (step 1) and the serum human chorionic gonadotropin (hCG) ratio, defined as the ratio of hCG at 48 h to hCG at presentation (step 2). This was a cohort study of 2753 PUL (301 EP), involving a secondary analysis of prospectively and consecutively collected PUL data from two London-based university teaching hospitals. Using a chronological split we used 1449 PUL for development and 1304 for validation. We aimed to assign PUL as low risk with high confidence (high negative predictive value (NPV)) while classifying most EP as high risk (high sensitivity). The first triage step assigned PUL as low risk using a threshold of serum progesterone at presentation. The remaining PUL were triaged using a novel logistic regression risk model based on hCG ratio and initial serum progesterone (second step), defining low risk as an estimated EP risk of < 5%. On validation, initial serum progesterone ≤ 2 nmol/L (step 1) classified 16.1% PUL as low risk. Second-step classification with the risk model selected an additional 46.0% of all PUL as low risk. Overall, the two-step protocol classified 62.1% of PUL as low risk, with an NPV of 98.6% and a sensitivity of 92.0%. When the risk model was used in isolation (i.e. without the first step), 60.5% of PUL were classified as low risk with 99.1% NPV and 94.9% sensitivity. PUL can be classified efficiently into being either high or low risk for complications using a two-step protocol involving initial progesterone and hCG levels and the hCG ratio. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Neural network based automatic limit prediction and avoidance system and method

NASA Technical Reports Server (NTRS)

Calise, Anthony J. (Inventor); Prasad, Jonnalagadda V. R. (Inventor); Horn, Joseph F. (Inventor)

2001-01-01

A method for performance envelope boundary cueing for a vehicle control system comprises the steps of formulating a prediction system for a neural network and training the neural network to predict values of limited parameters as a function of current control positions and current vehicle operating conditions. The method further comprises the steps of applying the neural network to the control system of the vehicle, where the vehicle has capability for measuring current control positions and current vehicle operating conditions. The neural network generates a map of current control positions and vehicle operating conditions versus the limited parameters in a pre-determined vehicle operating condition. The method estimates critical control deflections from the current control positions required to drive the vehicle to a performance envelope boundary. Finally, the method comprises the steps of communicating the critical control deflection to the vehicle control system; and driving the vehicle control system to provide a tactile cue to an operator of the vehicle as the control positions approach the critical control deflections.

Engineering bacterial translation initiation - Do we have all the tools we need?

PubMed

Vigar, Justin R J; Wieden, Hans-Joachim

2017-11-01

Reliable tools that allow precise and predictable control over gene expression are critical for the success of nearly all bioengineering applications. Translation initiation is the most regulated phase during protein biosynthesis, and is therefore a promising target for exerting control over gene expression. At the translational level, the copy number of a protein can be fine-tuned by altering the interaction between the translation initiation region of an mRNA and the ribosome. These interactions can be controlled by modulating the mRNA structure using numerous approaches, including small molecule ligands, RNAs, or RNA-binding proteins. A variety of naturally occurring regulatory elements have been repurposed, facilitating advances in synthetic gene regulation strategies. The pursuit of a comprehensive understanding of mechanisms governing translation initiation provides the framework for future engineering efforts. Here we outline state-of-the-art strategies used to predictably control translation initiation in bacteria. We also discuss current limitations in the field and future goals. Due to its function as the rate-determining step, initiation is the ideal point to exert effective translation regulation. Several engineering tools are currently available to rationally design the initiation characteristics of synthetic mRNAs. However, improvements are required to increase the predictability, effectiveness, and portability of these tools. Predictable and reliable control over translation initiation will allow greater predictability when designing, constructing, and testing genetic circuits. The ability to build more complex circuits predictably will advance synthetic biology and contribute to our fundamental understanding of the underlying principles of these processes. "This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

Jurassic subduction initiation in the western and central Neo-Tethys and the origin of the Balkan ophiolites

NASA Astrophysics Data System (ADS)

Van Hinsbergen, D. J. J.; Maffione, M.

2017-12-01

Jurassic subduction initiation in the Neo-Tethys Ocean was the first, critical step of a long tectonic process that eventually led to the collision of the Adria-Africa and Eurasia plates and the formation of a 6000 km long Alpine orogenic belt spanning from the Balkan Peninsula to Iran. Investigating the process of subduction initiation in the Neo-Tethys during the Jurassic is crucial to (i) reconstruct the complex geological evolution of this orogen from its initial stages, and (ii) shed new lights over the enigmatic kinematics and driving mechanisms of subduction initiation. Records of the initial closure of the Neo-Tethys are today preserved in a fragmented belt of Middle Jurassic ophiolites (170-160 Ma) distributed above the Alpine orogen. In particular, the well-preserved and extensively studied ophiolites of the Balkan Peninsula offer a unique chance to study the mechanisms leading to the closure of the western domain of the Neo-Tethys. Here we provide the first quantitative constraints on the geometry of the Jurassic Neo-Tethyan subduction system using a net tectonic rotation analysis based on paleomagnetic and structural geological data from the sheeted dyke complexes of various ophiolites of Serbia (Maljen, Ibar) and Greece (Othris, Pindos, Vourinos, Guevgueli). Our results show that closure of the western Neo-Tethys was accommodated by two subduction zones, one intra-oceanic, formed at the N-S trending Neo-Tethyan ridge, the other initiated at the European passive margin and curving southward from a N-S to a NW-SE direction following the shape of the passive margin. We propose that these two subduction zones formed upon propagation of subduction(s) initiated in the central Neo-Tethys (modern Turkey) in the late Early Jurassic ( 185-180 Ma).

Self-triggered assistive stimulus training improves step initiation in persons with Parkinson’s disease

PubMed Central

2013-01-01

Background Prior studies demonstrated that hesitation-prone persons with Parkinson’s disease (PDs) acutely improve step initiation using a novel self-triggered stimulus that enhances lateral weight shift prior to step onset. PDs showed reduced anticipatory postural adjustment (APA) durations, earlier step onsets, and faster 1st step speed immediately following stimulus exposure. Objective This study investigated the effects of long-term stimulus exposure. Methods Two groups of hesitation-prone subjects with Parkinson’s disease (PD) participated in a 6-week step-initiation training program involving one of two stimulus conditions: 1) Drop. The stance-side support surface was lowered quickly (1.5 cm); 2) Vibration. A short vibration (100 ms) was applied beneath the stance-side support surface. Stimuli were self-triggered by a 5% reduction in vertical force under the stance foot during the APA. Testing was at baseline, immediately post-training, and 6 weeks post-training. Measurements included timing and magnitude of ground reaction forces, and step speed and length. Results Both groups improved their APA force modulation after training. Contrary to previous results, neither group showed reduced APA durations or earlier step onset times. The vibration group showed 55% increase in step speed and a 39% increase in step length which were retained 6 weeks post-training. The drop group showed no stepping-performance improvements. Conclusions The acute sensitivity to the quickness-enhancing effects of stimulus exposure demonstrated in previous studies was supplanted by improved force modulation following prolonged stimulus exposure. The results suggest a potential approach to reduce the severity of start hesitation in PDs, but further study is needed to understand the relationship between short- and long-term effects of stimulus exposure. PMID:23363975

Aeromechanics and Aeroacoustics Predictions of the Boeing-SMART Rotor Using Coupled-CFD/CSD Analyses

NASA Technical Reports Server (NTRS)

Bain, Jeremy; Sim, Ben W.; Sankar, Lakshmi; Brentner, Ken

2010-01-01

This paper will highlight helicopter aeromechanics and aeroacoustics prediction capabilities developed by Georgia Institute of Technology, the Pennsylvania State University, and Northern Arizona University under the Helicopter Quieting Program (HQP) sponsored by the Tactical Technology Office of the Defense Advanced Research Projects Agency (DARPA). First initiated in 2004, the goal of the HQP was to develop high fidelity, state-of-the-art computational tools for designing advanced helicopter rotors with reduced acoustic perceptibility and enhanced performance. A critical step towards achieving this objective is the development of rotorcraft prediction codes capable of assessing a wide range of helicopter configurations and operations for future rotorcraft designs. This includes novel next-generation rotor systems that incorporate innovative passive and/or active elements to meet future challenging military performance and survivability goals.

Steroid Signaling and Temperature-Dependent Sex Determination – Reviewing the Evidence for Early Action of Estrogen during Ovarian Determination in the Red-Eared Slider Turtle (Trachemys scripta elegans)

PubMed Central

Ramsey, Mary; Crews, David

2009-01-01

The developmental processes underlying gonadal differentiation are conserved across vertebrates, but the triggers initiating these trajectories are extremely variable. The red-eared slider turtle (Trachemys scripta elegans) exhibits temperature-dependent sex determination (TSD), a system where incubation temperature during a temperature-sensitive period of development determines offspring sex. However, gonadal sex is sensitive to both temperature and hormones during this period – particularly estrogen. We present a model for temperature-based differences in aromatase expression as a critical step in ovarian determination. Localized estrogen production facilitates ovarian development while inhibiting male-specific gene expression. At male-producing temperatures aromatase is not upregulated, thereby allowing testis development. PMID:18992835

Optics Alignment of a Balloon-Borne Far-Infrared Interferometer BETTII

NASA Technical Reports Server (NTRS)

Dhabal, Arnab; Rinehart, Stephen A.; Rizzo, Maxime J.; Mundy, Lee; Sampler, Henry; Juanola Parramon, Roser; Veach, Todd; Fixsen, Dale; Vila Hernandez De Lorenzo, Jor; Silverberg, Robert F.

2017-01-01

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-m baseline far-infrared (FIR: 30 90 micrometer) interferometer providing spatially resolved spectroscopy. The initial scientific focus of BETTII is on clustered star formation, but this capability likely has a much broader scientific application.One critical step in developing an interferometer, such as BETTII, is the optical alignment of the system. We discuss how we determine alignment sensitivities of different optical elements on the interferogram outputs. Accordingly, an alignment plan is executed that makes use of a laser tracker and theodolites for precise optical metrology of both the large external optics and the small optics inside the cryostat. We test our alignment on the ground by pointing BETTII to bright near-infrared sources and obtaining their images in the tracking detectors.

Ignition, Burning, and Extinction of a Strained Fuel Strip

NASA Technical Reports Server (NTRS)

Selerland, T.; Karagozian, A. R.

1996-01-01

Flame structure and ignition and extinction processes associated with a strained fuel strip are explored numerically using detailed transport and complex kinetics for a propane-air reaction. Ignition modes are identified that are similar to those predicted by one-step activation energy asymptotics, i.e., modes in which diffusion flames can ignite as independent or dependent interfaces, and modes in which single premixed or partially premixed flames ignite. These ignition modes are found to be dependent on critical combinations of strain rate, fuel strip thickness, and initial reactant temperatures. Extinction in this configuration is seen to occur due to fuel consumption by adjacent flames, although viscosity is seen to have the effect of delaying extinction by reducing the effective strain rate and velocity field experienced by the flames.

Human Rights Education and Training for Professionals

NASA Astrophysics Data System (ADS)

Andreopoulos, George

2002-07-01

Although human rights education (HRE) has a long history, it has only recently begun to realize its transformative potential. A critical catalyst in this process is the emerging global ethos of accountability. Within this context, HRE can play a crucial role in the construction of a universal culture of human rights, inspired by a shared commitment to a humane order and a belief that human beings have both the capacity and the responsibility to make a difference. In such an effort, the training of professionals is vital, especially of those professionals who can influence public debate on accountability and governance. Innovative HRE initiatives, characterized by a commitment to experiential learning and to international and regional cooperation among state and non-state actors, constitute a step in the right direction.

Biomechanics of Step Initiation After Balance Recovery With Implications for Humanoid Robot Locomotion.

PubMed

Miller Buffinton, Christine; Buffinton, Elise M; Bieryla, Kathleen A; Pratt, Jerry E

2016-03-01

Balance-recovery stepping is often necessary for both a human and humanoid robot to avoid a fall by taking a single step or multiple steps after an external perturbation. The determination of where to step to come to a complete stop has been studied, but little is known about the strategy for initiation of forward motion from the static position following such a step. The goal of this study was to examine the human strategy for stepping by moving the back foot forward from a static, double-support position, comparing parameters from normal step length (SL) to those from increasing SLs to the point of step failure, to provide inspiration for a humanoid control strategy. Healthy young adults instrumented with joint reflective markers executed a prescribed-length step from rest while marker positions and ground reaction forces (GRFs) were measured. The participants were scaled to the Gait2354 model in opensim software to calculate body kinematic and joint kinetic parameters, with further post-processing in matlab. With increasing SL, participants reduced both static and push-off back-foot GRF. Body center of mass (CoM) lowered and moved forward, with additional lowering at the longer steps, and followed a path centered within the initial base of support (BoS). Step execution was successful if participants gained enough forward momentum at toe-off to move the instantaneous capture point (ICP) to within the BoS defined by the final position of both feet on the front force plate. All lower extremity joint torques increased with SL except ankle joint. Front knee work increased dramatically with SL, accompanied by decrease in back-ankle work. As SL increased, the human strategy changed, with participants shifting their CoM forward and downward before toe-off, thus gaining forward momentum, while using less propulsive work from the back ankle and engaging the front knee to straighten the body. The results have significance for human motion, suggesting the upper limit of the SL that can be completed with back-ankle push-off before additional knee flexion and torque is needed. For biped control, the results support stability based on capture-point dynamics and suggest strategy for center-of-mass trajectory and distribution of ground force reactions that can be compared with robot controllers for initiation of gait after recovery steps.

Inverting the planning gradient: adjustment of grasps to late segments of multi-step object manipulations.

PubMed

Mathew, Hanna; Kunde, Wilfried; Herbort, Oliver

2017-05-01

When someone grasps an object, the grasp depends on the intended object manipulation and usually facilitates it. If several object manipulation steps are planned, the first step has been reported to primarily determine the grasp selection. We address whether the grasp can be aligned to the second step, if the second step's requirements exceed those of the first step. Participants grasped and rotated a dial first by a small extent and then by various extents in the opposite direction, without releasing the dial. On average, when the requirements of the first and the second step were similar, participants mostly aligned the grasp to the first step. When the requirements of the second step were considerably higher, participants aligned the grasp to the second step, even though the first step still had a considerable impact. Participants employed two different strategies. One subgroup initially aligned the grasp to the first step and then ceased adjusting the grasp to either step. Another group also initially aligned the grasp to the first step and then switched to aligning it primarily to the second step. The data suggest that participants are more likely to switch to the latter strategy when they experienced more awkward arm postures. In summary, grasp selections for multi-step object manipulations can be aligned to the second object manipulation step, if the requirements of this step clearly exceed those of the first step and if participants have some experience with the task.

Change of wandering pattern with anisotropy in step kinetics

NASA Astrophysics Data System (ADS)

Sato, Masahide; Uwaha, Makio

1999-03-01

We study the effect of anisotropy in step kinetics on the wandering instability of an isolated step. With the asymmetry of the step kinetics, a straight step becomes unstable for long wavelength fluctuations and wanders when the step velocity exceeds a critical value. Near the threshold of the instability, an isotropic step obeys the Kuramoto-Sivashinsky equation, HT=- HXX- HXXXX+( H2X/2), and shows a chaotic pattern. A step with anisotropic kinetics obeys the Benney equation, HT=- HXX- δHXXX- HXXXX+( H2X/2), and the wandering pattern changes: when the anisotropy is strong, δ≫1, the step shows a regular pattern. Near the threshold of the instability, the anisotropy effect becomes strong while that of the step stiffness becomes weak.

29 CFR 1956.52 - Completed developmental steps and certification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Completed developmental steps and certification. 1956.52... PLANS New York § 1956.52 Completed developmental steps and certification. (a) In accordance with 29 CFR..., 2006 as having successfully completed all developmental steps specified in the plan as initially...

40 CFR 35.2203 - Step 7 projects.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Step 7 projects. 35.2203 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2203 Step 7 projects. (a) Prior to initiating action to acquire real property, a Step 7 grantee shall submit for Regional...

Photodamage: all signs lead to actinic keratosis and early squamous cell carcinoma.

PubMed

Wei, Jerry; Kok, Lai Fong; Byrne, Scott N; Halliday, Gary M

2015-01-01

Ultraviolet (UV) radiation is likely to drive the initiation and progression of skin cancer from actinic keratosis to squamous cell carcinoma. Signs of photodamage occur at multiple steps. UV radiation damages many cellular constituents, including lipids, proteins and DNA, all of which are likely to contribute to UV-induced skin cancer. Two biological events culminating from photodamage are mutations in the genes critical to the control of cell division, differentiation and invasion and immunosuppression. DNA photodamage, if unrepaired prior to cell division, can result in the incorporation of an incorrect nucleotide into newly synthesised DNA. Mutations in critical genes contribute to carcinogenesis. Photodamage to proteins such as those involved in DNA repair or proteins or lipids involved in cellular signalling can interfere with this repair process and contribute to mutagenesis. Mutations in key genes, including TP53, BRM, PTCH1, and HRAS, contribute to skin carcinogenesis. UV also damages immunity. Photodamage to DNA and signalling lipids as well as other molecular changes are detrimental to the key cells that regulate immunity. Photodamaged dendritic cells and altered responses by mast cells lead to the activation of T and B regulatory cells that suppress immunity to the protein products of UV-mutated genes. This stops the immune response from its protective function of destroying mutated cells, enabling the transformed cells to progress to skin cancer. UV appears to play a pivotal role at each of these steps, and therefore, signs of photodamage point to the development of skin cancer. © 2015 S. Karger AG, Basel.

The Effect of Backward-Facing Step Height on Instability Growth and Breakdown in Swept Wing Boundary-Layer Transition

NASA Technical Reports Server (NTRS)

Eppink, Jenna L.; Wlezien, Richard W.; King, Rudolph A.; Choudhari, Meelan

2015-01-01

A low-speed experiment was performed on a swept at plate model with an imposed pressure gradient to determine the effect of a backward-facing step on transition in a stationary-cross flow dominated flow. Detailed hot-wire boundary-layer measurements were performed for three backward-facing step heights of approximately 36, 45, and 49% of the boundary-layer thickness at the step. These step heights correspond to a subcritical, nearly-critical, and critical case. Three leading-edge roughness configurations were tested to determine the effect of stationary-cross flow amplitude on transition. The step caused a local increase in amplitude of the stationary cross flow for the two larger step height cases, but farther downstream the amplitude decreased and remained below the baseline amplitude. The smallest step caused a slight local decrease in amplitude of the primary stationary cross flow mode, but the amplitude collapsed back to the baseline case far downstream of the step. The effect of the step on the amplitude of the primary cross flow mode increased with step height, however, the stationary cross flow amplitudes remained low and thus, stationary cross flow was not solely responsible for transition. Unsteady disturbances were present downstream of the step for all three step heights, and the amplitudes increased with increasing step height. The only exception is that the lower frequency (traveling crossflow-like) disturbance was not present in the lowest step height case. Positive and negative spikes in instantaneous velocity began to occur for the two larger step height cases and then grew in number and amplitude downstream of reattachment, eventually leading to transition. The number and amplitude of spikes varied depending on the step height and cross flow amplitude. Despite the low amplitude of the disturbances in the intermediate step height case, breakdown began to occur intermittently and the flow underwent a long transition region.

Voluntary saccadic eye movements in humans studied with a double-cue paradigm.

PubMed

Sheliga, B M; Brown, V J; Miles, F A

2002-07-01

In the classic double-step paradigm, subjects are required to make a saccade to a visual target that is briefly presented at one location and then shifted to a new location before the subject has responded. The saccades in this situation are "reflexive" in that they are made in response to the appearance of the target itself. In the present experiments we adapted the double-step paradigm to study "voluntary" saccades. For this, several identical targets were always visible and subjects were given a cue to indicate that they should make a saccade to one of them. This cue was then changed to indicate another of the targets before the subject had responded: double-cue (DC) paradigm. The saccadic eye movements in our DC paradigm had many features in common with those in the double-step paradigm and we show that apparent differences can be attributed to the spatio-temporal arrangements of the cues/targets rather than to any intrinsic differences in the programming of these two kinds of eye movements. For example, a feature of our DC paradigm that is not seen in the usual double-step paradigm is that the second cue could cause transient delays of the initial saccade, and these delays still occurred when the second cue was reflexive--provided that it was at the fovea (as in our DC paradigm) and not in the periphery (as in the usual double-step paradigm). Thus, the critical factor for the delay was the retinal (foveal) location of the second cue/target--not whether it was cognitive or reflexive--and we argue that the second cue/target is here acting as a distractor. We conclude that the DC paradigm can be used to study the programming of voluntary saccades in the same way that the double-step paradigm can be used to study reflexive saccades.

Health information technology and implementation science: partners in progress in the VHA.

PubMed

Hynes, Denise M; Whittier, Erika R; Owens, Arika

2013-03-01

The Department of Veterans Affairs (VA) Quality Enhancement Research Initiative (QUERI) has demonstrated how implementation science can enhance the quality of health care. During this time an increasing number of implementation research projects have developed or utilized health information technology (HIT) innovations to leverage the VA's electronic health record and information systems. To describe the HIT approaches used and to characterize the facilitators and barriers to progress within implementation research projects in the VA QUERI program. Nine case studies were selected from among 88 projects and represented 8 of 14 HIT categories identified. Each case study included key informants whose roles on the project were principal investigator, implementation science and informatics development. We conducted documentation analysis and semistructured in-person interviews with key informants for each of the 9 case studies. We used qualitative analysis software to identify and thematically code information and interview responses. : Thematic analyses revealed 3 domains or pathways critical to progression through the QUERI steps. These pathways addressed: (1) compliance and collaboration with information technology policies and procedures; (2) operating within organizational policies and building collaborations with end users, clinicians, and administrators; and (3) obtaining and maintaining research resources and approvals. Sustained efforts in HIT innovation and in implementation science in the Veterans Health Administration demonstrates the interdependencies of these initiatives and the critical pathways that can contribute to progress. Other health care quality improvement efforts that rely on HIT can learn from the Veterans Health Administration experience.

Pressure Testing of a Minimum Gauge PRSEUS Panel

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew J.; Rouse, Marshall; Linton, Kim A.; Li, Victor P.

2011-01-01

Advanced aircraft configurations that have been developed to increase fuel efficiency require advanced, novel structural concepts capable of handling the unique load conditions that arise. One such concept is the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) developed by the Boeing Company. The PRSEUS concept is being investigated by NASA s Environmentally Responsible Aviation (ERA) Program for use in a hybrid-wing body (HWB) aircraft. This paper summarizes the analysis and test of a PRSEUS panel subjected to internal pressure, the first such pressure test for this structural concept. The pressure panel used minimum gauge skin, with stringer and frame configurations consistent with previous PRSEUS tests. Analysis indicated that for the minimum gauge skin panel, the stringer locations exhibit fairly linear response, but the skin bays between the stringers exhibit nonlinear response. Excellent agreement was seen between nonlinear analysis and test results in the critical portion at the center of the panel. The pristine panel was capable of withstanding the required 18.4 psi pressure load condition without exhibiting any damage. The impacted panel was capable of withstanding a pressure load in excess of 28 psi before initial failure occurred at the center stringer, and the panel was capable of sustaining increased pressure load after the initial failure. This successful PRSEUS panel pressure panel test was a critical step in the building block approach for enabling the use of this advanced structural concept on future aircraft, such as the HWB.

Preparing Synthetic Aβ in Different Aggregation States

PubMed Central

Stine, W. Blaine; Jungbauer, Lisa; Yu, Chunjiang; LaDu, Mary Jo

2013-01-01

This chapter outlines protocols that produce homogenous preparations of oligomeric and fibrillar amyloid -β peptide (Aβ). While there are several isoforms of this peptide, the 42 amino acid form is the focus because of its genetic and pathological link to Alzheimer’s disease (AD). Past decades of AD research highlight the dependence of Aβ42 function on its structural assembly state. Biochemical, cellular and in vivo studies of Aβ42 usually begin with purified peptide obtained by chemical synthesis or recombinant expression. The initial steps to solubilize and prepare these purified dry peptide stocks are critical to controlling the structural assembly of Aβ. To develop homogenous Aβ42 assemblies, we initially monomerize the peptide, erasing any “structural history” that could seed aggregation, by using a strong solvent. It is this starting material that has allowed us to define and optimize conditions that consistently produce homogenous solutions of soluble oligomeric and fibrillar Aβ42 assemblies. These preparations have been developed and characterized by using atomic force microscopy (AFM) to identify the structurally discrete species formed by Aβ42 under specific solution conditions. These preparations have been used extensively to demonstrate a variety of functional differences between oligomeric and fibrillar Aβ42. We also present a protocol for fluorescently labeling oligomeric Aβ42 that does not affect structure, as measured by AFM, or function, as measured by a cellular uptake assay. These reagents are critical experimental tools that allow for defining specific structure/function connections. PMID:20967580

Effects of an aft facing step on the surface of a laminar flow glider wing

NASA Technical Reports Server (NTRS)

Sandlin, Doral R.; Saiki, Neal

1993-01-01

A motor glider was used to perform a flight test study on the effects of aft facing steps in a laminar boundary layer. This study focuses on two dimensional aft facing steps oriented spanwise to the flow. The size and location of the aft facing steps were varied in order to determine the critical size that will force premature transition. Transition over a step was found to be primarily a function of Reynolds number based on step height. Both of the step height Reynolds numbers for premature and full transition were determined. A hot film anemometry system was used to detect transition.

Simplified Two-Time Step Method for Calculating Combustion and Emission Rates of Jet-A and Methane Fuel With and Without Water Injection

NASA Technical Reports Server (NTRS)

Molnar, Melissa; Marek, C. John

2005-01-01

A simplified kinetic scheme for Jet-A, and methane fuels with water injection was developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) or even simple FORTRAN codes. The two time step method is either an initial time averaged value (step one) or an instantaneous value (step two). The switch is based on the water concentration in moles/cc of 1x10(exp -20). The results presented here results in a correlation that gives the chemical kinetic time as two separate functions. This two time step method is used as opposed to a one step time averaged method previously developed to determine the chemical kinetic time with increased accuracy. The first time averaged step is used at the initial times for smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, initial water to fuel mass ratio, temperature, and pressure. The second instantaneous step, to be used with higher water concentrations, gives the chemical kinetic time as a function of instantaneous fuel and water mole concentration, pressure and temperature (T4). The simple correlations would then be compared to the turbulent mixing times to determine the limiting rates of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide and NOx are obtained for Jet-A fuel and methane with and without water injection to water mass loadings of 2/1 water to fuel. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentrations of carbon monoxide and nitrogen oxide as functions of overall equivalence ratio, water to fuel mass ratio, pressure and temperature (T3). The temperature of the gas entering the turbine (T4) was also correlated as a function of the initial combustor temperature (T3), equivalence ratio, water to fuel mass ratio, and pressure.

Meeting information needs of families of critical care patients.

PubMed

Barbret, L C; Westphal, C G; Daly, G A

1997-01-01

Families of patients in critical care experience extreme anxiety and frustration while awaiting their loved ones' recovery or stabilization. To study the hypothesis that meeting families' informational needs can reduce their anxiety and help them cope with the initial crisis, a small task force at a Midwest acute care facility, using a CQI approach, studied possible solutions. Initial findings showed low satisfaction for families of critically ill patients with the present system of imparting information to them. After initiation of a storyboard to present information by the critical care team, families reported increased satisfaction and greater knowledge recall.

Critical thinking analysis based on Facione (2015) – Angelo (1995) logical mathematics material of vocational high school (VHS)

NASA Astrophysics Data System (ADS)

Seventika, S. Y.; Sukestiyarno, Y. L.; Mariani, Scolastika

2018-03-01

The research has purpose to analyze and categorize the critical thinking ability of VHS students based on modified critical thinking indicator according to Facione-Angelo covering: interpreting the problem, analyzing alternative solution, applying the problem, evaluating the solution and concluding the results gained – attached by supportive evidence. The subject of the research is 30 eleventh graders of TKJ in Yabujah VHS, Indramayu in the odd semester 2016/2017. The collected data are critical thinking test and interviews. The result shows 15% is in good category, 30% in fair category, and 55% in low category. The students in “Good” category has accomplished critical thinking steps although imperfect, especially the indicators of evaluating and concluding attached by supportive evidence. The “Fair” categorized students only show partial steps of the indicators. The analyzing, evaluating, and concluding indicators are the most seldom to do, meanwhile the “low” categorized students show all indicators in low quality even to identify has problem to do.

Foot and Ankle Kinematics During Descent From Varying Step Heights.

PubMed

Gerstle, Emily E; O'Connor, Kristian; Keenan, Kevin G; Cobb, Stephen C

2017-12-01

In the general population, one-third of incidences during step negotiation occur during the transition to level walking. Furthermore, falls during curb negotiation are a common cause of injury in older adults. Distal foot kinematics may be an important factor in determining injury risk associated with transition step negotiation. The purpose of this study was to identify foot and ankle kinematics of uninjured individuals during descent from varying step heights. A 7-segment foot model was used to quantify kinematics as participants walked on a level walkway, stepped down a single step (heights: 5 cm, 15 cm, 25 cm), and continued walking. As step height increased, landing strategy transitioned from the rearfoot to the forefoot, and the rearfoot, lateral and medial midfoot, and medial forefoot became more plantar flexed. During weight acceptance, sagittal plane range of motion of the rearfoot, lateral midfoot, and medial and lateral forefoot increased as step height increased. The changes in landing strategy and distal foot function suggest a less stable ankle position at initial contact and increased demand on the distal foot at initial contact and through the weight acceptance phase of transition step negotiation as step height increases.

Driven neutron star collapse: Type I critical phenomena and the initial black hole mass distribution

NASA Astrophysics Data System (ADS)

Noble, Scott C.; Choptuik, Matthew W.

2016-01-01

We study the general relativistic collapse of neutron star (NS) models in spherical symmetry. Our initially stable models are driven to collapse by the addition of one of two things: an initially ingoing velocity profile, or a shell of minimally coupled, massless scalar field that falls onto the star. Tolman-Oppenheimer-Volkoff (TOV) solutions with an initially isentropic, gamma-law equation of state serve as our NS models. The initial values of the velocity profile's amplitude and the star's central density span a parameter space which we have surveyed extensively and which we find provides a rich picture of the possible end states of NS collapse. This parameter space survey elucidates the boundary between Type I and Type II critical behavior in perfect fluids which coincides, on the subcritical side, with the boundary between dispersed and bound end states. For our particular model, initial velocity amplitudes greater than 0.3 c are needed to probe the regime where arbitrarily small black holes can form. In addition, we investigate Type I behavior in our system by varying the initial amplitude of the initially imploding scalar field. In this case we find that the Type I critical solutions resemble TOV solutions on the 1-mode unstable branch of equilibrium solutions, and that the critical solutions' frequencies agree well with the fundamental mode frequencies of the unstable equilibria. Additionally, the critical solution's scaling exponent is shown to be well approximated by a linear function of the initial star's central density.

Continuous powder feeding for pharmaceutical solid dosage form manufacture: a short review.

PubMed

Blackshields, Caroline A; Crean, Abina M

2018-07-01

There has been a noticeable shift from pharmaceutical batch processing towards a more continuous mode of manufacture for solid oral dosage forms. Continuous solid oral dose processes would not be possible in the absence of a highly accurate feeding system. The performance of feeders defines the content of formulations and is therefore a critical operation in continuous manufacturing of solid dosage forms. It was the purpose of this review to review the role of the initial powder feeding step in a continuous manufacturing process. Different feeding mechanisms are discussed with a particular emphasis on screw controlled loss in weight (LIW) feeding. The importance of understanding the physical properties of the raw materials and its impact on the feeding process is reviewed. Prior knowledge of materials provides an initial indication of how the powders will behave through processing and facilitates in the selection of the most suitable (i) feeder (capacity), (ii) feeding mechanism, and (iii) in the case of screw feeder - screw type. The studies identified in this review focus on the impact of material on powder feeding performance.

Reciprocal Signaling between the Ectoderm and a Mesendodermal Left-Right Organizer Directs Left-Right Determination in the Sea Urchin Embryo

PubMed Central

Bessodes, Nathalie; Haillot, Emmanuel; Duboc, Véronique; Röttinger, Eric; Lahaye, François; Lepage, Thierry

2012-01-01

During echinoderm development, expression of nodal on the right side plays a crucial role in positioning of the rudiment on the left side, but the mechanisms that restrict nodal expression to the right side are not known. Here we show that establishment of left-right asymmetry in the sea urchin embryo relies on reciprocal signaling between the ectoderm and a left-right organizer located in the endomesoderm. FGF/ERK and BMP2/4 signaling are required to initiate nodal expression in this organizer, while Delta/Notch signaling is required to suppress formation of this organizer on the left side of the archenteron. Furthermore, we report that the H+/K+-ATPase is critically required in the Notch signaling pathway upstream of the S3 cleavage of Notch. Our results identify several novel players and key early steps responsible for initiation, restriction, and propagation of left-right asymmetry during embryogenesis of a non-chordate deuterostome and uncover a functional link between the H+/K+-ATPase and the Notch signaling pathway. PMID:23271979

Intragranular cracking as a critical barrier for high-voltage usage of layer-structured cathode for lithium-ion batteries

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

Yan, Pengfei; Zheng, Jianming; Gu, Meng

LiNi 1/3Mn 1/3Co 1/3O 2 (NMC333) layered cathode is often fabricated as secondary particles of consisting of densely packed primary particles, which offers advantage of high energy density and alleviation of cathode side reactions/corrosions, but introduces other drawbacks, such as intergranular cracking. Here, we report unexpected observations on the nucleation and growth of intragranular cracks in the commercial NMC333 layered cathode by using advanced S/TEM. We found that the formation of the intragranular cracks is directly associated with high voltage cycling, which is an electrochemically driven and diffusion controlled process. The intragranular cracks were noticed to be characteristically initiated frommore » grain interior, a consequence of dislocation based crack incubation mechanism. This observation is in sharp contrast with the general theoretical models, predicting the initiation of intragranular cracks from grain boundaries or particle surface. As a result, our study indicates that maintain a structural stability is the key step toward high voltage operation of layered cathode materials.« less

Nasal embryonic LHRH factor plays a role in the developmental migration and projection of gonadotropin-releasing hormone 3 neurons in zebrafish.

PubMed

Palevitch, Ori; Abraham, Eytan; Borodovsky, Natalya; Levkowitz, Gil; Zohar, Yonathan; Gothilf, Yoav

2009-01-01

The initiation of puberty and the functioning of the reproductive system depend on proper development of the hypophysiotropic gonadotropin-releasing hormone (GnRH) system. One critical step in this process is the embryonic migration of GnRH neurons from the olfactory area to the hypothalamus. Using a transgenic zebrafish model, Tg(gnrh3:EGFP), in which GnRH3 neurons and axons are fluorescently labeled, we investigated whether zebrafish NELF is essential for the development of GnRH3 neurons. The zebrafish nelf cDNA was cloned and characterized. During embryonic development, nelf is expressed in GnRH3 neurons and in target sites of GnRH3 projections and perikarya, before the initiation of their migration. Nelf knockdown resulted in a disruption of the GnRH3 system which included absence or misguiding of GnRH3 axonal outgrowth and incorrect or arrested migration of GnRH3 perikarya. These results suggest that Nelf is an important factor in the developmental migration and projection of GnRH3 neurons in zebrafish. Copyright (c) 2008 Wiley-Liss, Inc.

Birth order dependent growth cone segregation determines synaptic layer identity in the Drosophila visual system

PubMed Central

Kulkarni, Abhishek; Ertekin, Deniz; Lee, Chi-Hon; Hummel, Thomas

2016-01-01

The precise recognition of appropriate synaptic partner neurons is a critical step during neural circuit assembly. However, little is known about the developmental context in which recognition specificity is important to establish synaptic contacts. We show that in the Drosophila visual system, sequential segregation of photoreceptor afferents, reflecting their birth order, lead to differential positioning of their growth cones in the early target region. By combining loss- and gain-of-function analyses we demonstrate that relative differences in the expression of the transcription factor Sequoia regulate R cell growth cone segregation. This initial growth cone positioning is consolidated via cell-adhesion molecule Capricious in R8 axons. Further, we show that the initial growth cone positioning determines synaptic layer selection through proximity-based axon-target interactions. Taken together, we demonstrate that birth order dependent pre-patterning of afferent growth cones is an essential pre-requisite for the identification of synaptic partner neurons during visual map formation in Drosophila. DOI: http://dx.doi.org/10.7554/eLife.13715.001 PMID:26987017

Optimal design of the satellite constellation arrangement reconfiguration process

NASA Astrophysics Data System (ADS)

Fakoor, Mahdi; Bakhtiari, Majid; Soleymani, Mahshid

2016-08-01

In this article, a novel approach is introduced for the satellite constellation reconfiguration based on Lambert's theorem. Some critical problems are raised in reconfiguration phase, such as overall fuel cost minimization, collision avoidance between the satellites on the final orbital pattern, and necessary maneuvers for the satellites in order to be deployed in the desired position on the target constellation. To implement the reconfiguration phase of the satellite constellation arrangement at minimal cost, the hybrid Invasive Weed Optimization/Particle Swarm Optimization (IWO/PSO) algorithm is used to design sub-optimal transfer orbits for the satellites existing in the constellation. Also, the dynamic model of the problem will be modeled in such a way that, optimal assignment of the satellites to the initial and target orbits and optimal orbital transfer are combined in one step. Finally, we claim that our presented idea i.e. coupled non-simultaneous flight of satellites from the initial orbital pattern will lead to minimal cost. The obtained results show that by employing the presented method, the cost of reconfiguration process is reduced obviously.

Specification of Dendritogenesis Site in Drosophila aCC Motoneuron by Membrane Enrichment of Pak1 through Dscam1.

PubMed

Kamiyama, Daichi; McGorty, Ryan; Kamiyama, Rie; Kim, Michael D; Chiba, Akira; Huang, Bo

2015-10-12

Precise positioning of dendritic branches is a critical step in the establishment of neuronal circuitry. However, there is limited knowledge on how environmental cues translate into dendrite initiation or branching at a specific position. Here, through a combination of mutation, RNAi, and imaging experiments, we found that a Dscam-Dock-Pak1 hierarchical interaction defines the stereotypical dendrite growth site in the Drosophila aCC motoneuron. This interaction localizes the Cdc42 effector Pak1 to the plasma membrane at the dendrite initiation site before the activation of Cdc42. Ectopic expression of membrane-anchored Pak1 overrides this spatial specification of dendritogenesis, confirming its function in guiding Cdc42 signaling. We further discovered that Dscam1 localization in aCC occurs through an inter-neuronal contact that involves Dscam1 in the partner MP1 neuron. These findings elucidate a mechanism by which Dscam1 controls neuronal morphogenesis through spatial regulation of Cdc42 signaling and, subsequently, cytoskeletal remodeling. Copyright © 2015 Elsevier Inc. All rights reserved.

Intersections and evolution of 'Butch-trans' categories in Puerto Rico: Needs and barriers of an invisible population.

PubMed

Ramos-Pibernus, Alíxida G; Rodríguez-Madera, Sheilla L; Padilla, Mark; Varas-Díaz, Nelson; Vargas Molina, Ricardo

2016-01-01

Public health research among transgender populations globally has primarily focused on HIV/AIDS. However, trans men remain outside of this conceptual framework, with distinct but overlapping social contexts and needs. In Puerto Rico (PR), the trans men population has remained largely hidden within the 'butch' lesbian community. The objective of this article is to document the identity construction of trans men and 'buchas' (local term to refer to butch lesbians) in PR and its relation to their bodily practices and overall health. We conducted an exploratory qualitative study with 29 trans men and buchas based on ethnographic observation, focus groups, audio-recorded in-depth interviews, and critical discourse analysis. Findings emphasise two domains to be addressed by health policies and initiatives: (1) bodily representations and gender performance, and (2) the meanings of female biological processes. This small-scale ethnographic study represents an initial step towards understanding the social context of this 'invisible' community and significant implications for their health and well-being. We provide several recommendations to address public health concerns of this understudied, marginalised community.

Intersections and evolution of ‘Butch-trans’ categories in Puerto Rico: Needs and barriers of an invisible population

PubMed Central

Ramos-Pibernus, Alíxida G.; Rodríguez-Madera, Sheilla L.; Padilla, Mark; Varas-Díaz, Nelson; Molina, Ricardo Vargas

2016-01-01

Public health research among transgender populations globally has primarily focused on HIV/AIDS. However, trans men remain outside of this conceptual framework, with distinct but overlapping social contexts and needs. In Puerto Rico (PR), the trans men population has remained largely hidden within the ‘butch’ lesbian community. The objective of this article is to document the identity construction of trans men and ‘buchas’ (local term to refer to butch lesbians) in PR and its relation to their bodily practices and overall health. We conducted an exploratory qualitative study with 29 trans men and buchas based on ethnographic observation; focus groups; audio-recorded in-depth interviews; and critical discourse analysis. Findings emphasize two domains to be addressed by health policies and initiatives: 1) bodily representations and gender performance, and 2) the meanings of female biological processes. This small-scale ethnographic study represents an initial step toward understanding the social context of this ‘invisible’ community and significant implications for their health and well-being. We provide several recommendations to address public health concerns of this understudied, marginalized community. PMID:27142002

Stakeholder conceptualisation of multi-level HIV and AIDS determinants in a Black epicentre.

PubMed

Brawner, Bridgette M; Reason, Janaiya L; Hanlon, Kelsey; Guthrie, Barbara; Schensul, Jean J

2017-09-01

HIV has reached epidemic proportions among African Americans in the USA but certain urban contexts appear to experience a disproportionate disease burden. Geographic information systems mapping in Philadelphia indicates increased HIV incidence and prevalence in predominantly Black census tracts, with major differences across adjacent communities. What factors shape these geographic HIV disparities among Black Philadelphians? This descriptive study was designed to refine and validate a conceptual model developed to better understand multi-level determinants of HIV-related risk among Black Philadelphians. We used an expanded ecological approach to elicit reflective perceptions from administrators, direct service providers and community members about individual, social and structural factors that interact to protect against or increase the risk for acquiring HIV within their community. Gender equity, social capital and positive cultural mores (e.g., monogamy, abstinence) were seen as the main protective factors. Historical negative contributory influences of racial residential segregation, poverty and incarceration were among the most salient risk factors. This study was a critical next step toward initiating theory-based, multi-level community-based HIV prevention initiatives.

Intragranular cracking as a critical barrier for high-voltage usage of layer-structured cathode for lithium-ion batteries

DOE PAGES

Yan, Pengfei; Zheng, Jianming; Gu, Meng; ...

2017-01-16

LiNi 1/3Mn 1/3Co 1/3O 2 (NMC333) layered cathode is often fabricated as secondary particles of consisting of densely packed primary particles, which offers advantage of high energy density and alleviation of cathode side reactions/corrosions, but introduces other drawbacks, such as intergranular cracking. Here, we report unexpected observations on the nucleation and growth of intragranular cracks in the commercial NMC333 layered cathode by using advanced S/TEM. We found that the formation of the intragranular cracks is directly associated with high voltage cycling, which is an electrochemically driven and diffusion controlled process. The intragranular cracks were noticed to be characteristically initiated frommore » grain interior, a consequence of dislocation based crack incubation mechanism. This observation is in sharp contrast with the general theoretical models, predicting the initiation of intragranular cracks from grain boundaries or particle surface. As a result, our study indicates that maintain a structural stability is the key step toward high voltage operation of layered cathode materials.« less

Publication guidelines for quality improvement in health care: evolution of the SQUIRE project

PubMed Central

Davidoff, F; Batalden, P; Stevens, D; Ogrinc, G; Mooney, S

2008-01-01

In 2005, draft guidelines were published for reporting studies of quality improvement interventions as the initial step in a consensus process for development of a more definitive version. This article contains the full revised version of the guidelines, which the authors refer to as SQUIRE (Standards for QUality Improvement Reporting Excellence). This paper also describes the consensus process, which included informal feedback from authors, editors and peer reviewers who used the guidelines; formal written commentaries; input from a group of publication guideline developers; ongoing review of the literature on the epistemology of improvement and methods for evaluating complex social programmes; a two-day meeting of stakeholders for critical discussion and debate of the guidelines’ content and wording; and commentary on sequential versions of the guidelines from an expert consultant group. Finally, the authors consider the major differences between SQUIRE and the initial draft guidelines; limitations of and unresolved questions about SQUIRE; ancillary supporting documents and alternative versions that are under development; and plans for dissemination, testing and further development of SQUIRE. PMID:18836063

Adaptation of catch-up saccades during the initiation of smooth pursuit eye movements.

PubMed

Schütz, Alexander C; Souto, David

2011-04-01

Reduction of retinal speed and alignment of the line of sight are believed to be the respective primary functions of smooth pursuit and saccadic eye movements. As the eye muscles strength can change in the short-term, continuous adjustments of motor signals are required to achieve constant accuracy. While adaptation of saccade amplitude to systematic position errors has been extensively studied, we know less about the adaptive response to position errors during smooth pursuit initiation, when target motion has to be taken into account to program saccades, and when position errors at the saccade endpoint could also be corrected by increasing pursuit velocity. To study short-term adaptation (250 adaptation trials) of tracking eye movements, we introduced a position error during the first catch-up saccade made during the initiation of smooth pursuit-in a ramp-step-ramp paradigm. The target position was either shifted in the direction of the horizontally moving target (forward step), against it (backward step) or orthogonally to it (vertical step). Results indicate adaptation of catch-up saccade amplitude to back and forward steps. With vertical steps, saccades became oblique, by an inflexion of the early or late saccade trajectory. With a similar time course, post-saccadic pursuit velocity was increased in the step direction, adding further evidence that under some conditions pursuit and saccades can act synergistically to reduce position errors.

Step-wise supercritical extraction of carbonaceous residua

DOEpatents

Warzinski, Robert P.

1987-01-01

A method of fractionating a mixture containing high boiling carbonaceous material and normally solid mineral matter includes processing with a plurality of different supercritical solvents. The mixture is treated with a first solvent of high critical temperature and solvent capacity to extract a large fraction as solute. The solute is released as liquid from solvent and successively treated with other supercritical solvents of different critical values to extract fractions of differing properties. Fractionation can be supplemented by solute reflux over a temperature gradient, pressure let down in steps and extractions at varying temperature and pressure values.

Initiating and optimizing acute therapy for migraine: the role of patient-centered stratified care.

PubMed

Diamond, Merle; Cady, Roger

2005-03-01

Migraine is a chronic, intermittently disabling condition that affects physical, mental, and social aspects of health-related quality of life. Because patients seeking assistance with migraine most often present to primary care providers, these healthcare professionals play critical roles in the diagnosis and treatment process. A comprehensive migraine management plan involves a partnership between the patient and healthcare professional where treatment goals and strategies are established. Elements of such a plan should include preventive strategies to reduce the frequency and effects of future attacks as well as the use of acute treatments to address the immediate need for relief during an attack. Approaches to prevention include education, lifestyle modification, and, often, appropriate medication. Many medications have been used for acute treatment. Nonspecific agents include nonsteroidal anti-inflammatory drugs (NSAIDs), single or combination analgesics (sometimes including antiemetics or caffeine), and narcotics. Migraine-specific medications include ergot alkaloids and triptans (5-hydroxytryptamine(1B/1D) agonists). Various professional organizations have created guidelines to help providers in choosing appropriate management interventions. Clinical approaches to the patient with migraine include step care, whereby all patients begin on a simple or nonspecific treatment, stepping up to the next level of therapy if treatment is unsuccessful; or stratified care, whereby first-line therapy is tailored to the severity of the patient's pattern of headache. Studies have demonstrated that for more disabled headache patients, the stratified-care approach results in more robust headache response with less disability and greater cost-effectiveness than step care. Patient satisfaction studies demonstrate that the use of migraine-specific abortive medications (triptans) is associated with a higher satisfaction rate than over-the-counter preparations, NSAIDs, and analgesic combinations. Patients who initially reported satisfaction with the latter medications also reported a preference for triptan therapy. Healthcare professionals can assist patients, not only by choosing the most appropriate medication but also by assessing whether the level of benefit the patient is currently receiving could be improved.

40 CFR 35.2202 - Step 2+3 projects.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Step 2+3 projects. 35.2202 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2202 Step 2+3 projects. (a) Prior to initiating action to acquire eligible real property, a Step 2+3 grantee shall submit for...

APWPs: Critical Building Steps and Potential for Future Geodynamical Studies.

NASA Astrophysics Data System (ADS)

Besse, J.

2004-12-01

Among other items, the Apparent Polar Wander Paths (APWP) of individual tectonic blocks contain information on geodynamical events from both shallower lithospheric sources (e.g. continental breakups and collisions) and deeper mantle sources affected by convection. Recent advances in the Earth Sciences, such as provided by global tomography or climate modeling, have emphasized the essential need for accurate reconstructions of the Earth's surface (blocks, plates and their boundaries and topographies), in order for instance to compare the initial positions of downgoing slabs or emerging hot spots with deeper mantle features, or to understand why and how time-varying climates and biomes may be related. A half century after its initial pionneering contributions to the formulation of continental drift and plate tectonics, paleomagnetism remains an invaluable tool which will allow us to solve a very large range of problems concerning both internal and external geodynamics (solid, fluid and bio-spheres). The accurate determination of the APWPs of crustal and lithospheric blocks remains one of the main goals that must be pursued by the paleomagnetic community. Based on two examples, one extending from Permian to Present, the other in the Late Proterozoic to Early Paleozoic, I will discuss various aspects of the construction of APWPs and reconstruction of past plate positions. Critical steps involve: 1) how are original paleomagnetic data selected? 2) how are the kinematic models used to transfer data from one plate to the other determined ? 3) how can poles coming from deformed (e.g. rotated) regions be used ? and 4) how good is the geocentric axial dipole (GAD) assumption, which is fundamental for reliable plate reconstructions ? Particular emphasis will be given to this last topic, since the GAD hypothesis has recently been challenged, with suggestions that significant long-term octupolar contributions might have existed from the Precambrian throughout to the early Tertiary. These might account for the low inclinations observed in central Asia in the Cretaceous and early Tertiary, or for the misfits of Pangea (Pangea A or B?). GAD hypothesis appears to be essentially correct and APWPs still have a bright future.

Kinematic and behavioral analyses of protective stepping strategies and risk for falls among community living older adults.

PubMed

Bair, Woei-Nan; Prettyman, Michelle G; Beamer, Brock A; Rogers, Mark W

2016-07-01

Protective stepping evoked by externally applied lateral perturbations reveals balance deficits underlying falls. However, a lack of comprehensive information about the control of different stepping strategies in relation to the magnitude of perturbation limits understanding of balance control in relation to age and fall status. The aim of this study was to investigate different protective stepping strategies and their kinematic and behavioral control characteristics in response to different magnitudes of lateral waist-pulls between older fallers and non-fallers. Fifty-two community-dwelling older adults (16 fallers) reacted naturally to maintain balance in response to five magnitudes of lateral waist-pulls. The balance tolerance limit (BTL, waist-pull magnitude where protective steps transitioned from single to multiple steps), first step control characteristics (stepping frequency and counts, spatial-temporal kinematic, and trunk position at landing) of four naturally selected protective step types were compared between fallers and non-fallers at- and above-BTL. Fallers took medial-steps most frequently while non-fallers most often took crossover-back-steps. Only non-fallers varied their step count and first step control parameters by step type at the instants of step initiation (onset time) and termination (trunk position), while both groups modulated step execution parameters (single stance duration and step length) by step type. Group differences were generally better demonstrated above-BTL. Fallers primarily used a biomechanically less effective medial-stepping strategy that may be partially explained by reduced somato-sensation. Fallers did not modulate their step parameters by step type at first step initiation and termination, instances particularly vulnerable to instability, reflecting their limitations in balance control during protective stepping. Copyright © 2016. Published by Elsevier Ltd.

A review for identification of initiating events in event tree development process on nuclear power plants

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

Riyadi, Eko H., E-mail: e.riyadi@bapeten.go.id

2014-09-30

Initiating event is defined as any event either internal or external to the nuclear power plants (NPPs) that perturbs the steady state operation of the plant, if operating, thereby initiating an abnormal event such as transient or loss of coolant accident (LOCA) within the NPPs. These initiating events trigger sequences of events that challenge plant control and safety systems whose failure could potentially lead to core damage or large early release. Selection for initiating events consists of two steps i.e. first step, definition of possible events, such as by evaluating a comprehensive engineering, and by constructing a top level logicmore » model. Then the second step, grouping of identified initiating event's by the safety function to be performed or combinations of systems responses. Therefore, the purpose of this paper is to discuss initiating events identification in event tree development process and to reviews other probabilistic safety assessments (PSA). The identification of initiating events also involves the past operating experience, review of other PSA, failure mode and effect analysis (FMEA), feedback from system modeling, and master logic diagram (special type of fault tree). By using the method of study for the condition of the traditional US PSA categorization in detail, could be obtained the important initiating events that are categorized into LOCA, transients and external events.« less

A gaussian mixture + demons deformable registration method for cone-beam CT-guided robotic transoral base-of-tongue surgery

NASA Astrophysics Data System (ADS)

Reaungamornrat, S.; Liu, W. P.; Schafer, S.; Otake, Y.; Nithiananthan, S.; Uneri, A.; Richmon, J.; Sorger, J.; Siewerdsen, J. H.; Taylor, R. H.

2013-03-01

Purpose: An increasingly popular minimally invasive approach to resection of oropharyngeal / base-of-tongue cancer is made possible by a transoral technique conducted with the assistance of a surgical robot. However, the highly deformed surgical setup (neck flexed, mouth open, and tongue retracted) compared to the typical patient orientation in preoperative images poses a challenge to guidance and localization of the tumor target and adjacent critical anatomy. Intraoperative cone-beam CT (CBCT) can account for such deformation, but due to the low contrast of soft-tissue in CBCT images, direct localization of the target and critical tissues in CBCT images can be difficult. Such structures may be more readily delineated in preoperative CT or MR images, so a method to deformably register such information to intraoperative CBCT could offer significant value. This paper details the initial implementation of a deformable registration framework to align preoperative images with the deformed intraoperative scene and gives preliminary evaluation of the geometric accuracy of registration in CBCT-guided TORS. Method: The deformable registration aligns preoperative CT or MR to intraoperative CBCT by integrating two established approaches. The volume of interest is first segmented (specifically, the region of the tongue from the tip to the hyoid), and a Gaussian mixture (GM) mode1 of surface point clouds is used for rigid initialization (GMRigid) as well as an initial deformation (GMNonRigid). Next, refinement of the registration is performed using the Demons algorithm applied to distance transformations of the GM-registered and CBCT volumes. The registration accuracy of the framework was quantified in preliminary studies using a cadaver emulating preoperative and intraoperative setups. Geometric accuracy of registration was quantified in terms of target registration error (TRE) and surface distance error. Result: With each step of the registration process, the framework demonstrated improved registration, achieving mean TRE of 3.0 mm following the GM rigid, 1.9 mm following GM nonrigid, and 1.5 mm at the output of the registration process. Analysis of surface distance demonstrated a corresponding improvement of 2.2, 0.4, and 0.3 mm, respectively. The evaluation of registration error revealed the accurate alignment in the region of interest for base-of-tongue robotic surgery owing to point-set selection in the GM steps and refinement in the deep aspect of the tongue in the Demons step. Conclusions: A promising framework has been developed for CBCT-guided TORS in which intraoperative CBCT provides a basis for registration of preoperative images to the highly deformed intraoperative setup. The registration framework is invariant to imaging modality (accommodating preoperative CT or MR) and is robust against CBCT intensity variations and artifact, provided corresponding segmentation of the volume of interest. The approach could facilitate overlay of preoperative planning data directly in stereo-endoscopic video in support of CBCT-guided TORS.

The impact of a public health department's expansion from a one-step to a two-step refugee screening process on the detection and initiation of treatment of latent tuberculosis.

PubMed

Einterz, E M; Younge, O; Hadi, C

2018-06-01

To determine, subsequent to the expansion of a county health department's refugee screening process from a one-step to a two-step process, the change in early loss to follow-up and time to initiation of treatment of new refugees with latent tuberculosis infection (LTBI). Quasi-experimental, quantitative. Review of patient medical records. Among 384 refugees who met the case definition of LTBI without prior tuberculosis (TB) classification, the number of cases lost to early follow-up fell from 12.5% to 0% after expansion to a two-step screening process. The average interval between in-country arrival and initiation of LTBI treatment was shortened by 41.4%. The addition of a second step to the refugee screening process was correlated with significant improvements in the county's success in tracking and treating cases of LTBI in refugees. Given the disproportionate importance of foreign-born cases of LTBI to the incidence of TB disease in low-incidence countries, these improvements could have a substantial impact on overall TB control, and the process described could serve as a model for other local health department refugee screening programs. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Initiation of forward gait with lateral occurrence of emotional stimuli: general findings and relevance for pedestrians crossing roads.

PubMed

Caffier, D; Gillet, C; Heurley, L P; Bourrelly, A; Barbier, F; Naveteur, J

2017-03-01

With reference to theoretical models regarding links between emotions and actions, the present study examined whether the lateral occurrence of an emotional stimulus influences spatial and temporal parameters of gait initiation in 18 younger and 18 older healthy adults. In order to simulate road-crossing hazard for pedestrians, slides of approaching cars were used and they were presented in counterbalanced order with threatening slides from the International Affective Picture System (IAPS) and control slides of safe walking areas. Each slide was presented on the left side of the participant once the first step was initiated. The results evidenced medio-lateral shifts to the left for the first step (right foot) and to the right for the second step (left foot). These shifts were both modulated by the slide contents in such a way that the resulting distance between the screen and the foot (right or left) was larger with the IAPS and traffic slides than with the control slides. The slides did not affect the base of support, step length, step velocity and time of double support. Advancing age influenced the subjective impact of the slides and gait characteristics, but did not modulate medio-lateral shifts. The data extend evidence of fast, emotional modulation of stepping, with theoretical and applied consequences.

Hybrid method to estimate two-layered superficial tissue optical properties from simulated data of diffuse reflectance spectroscopy.

PubMed

Hsieh, Hong-Po; Ko, Fan-Hua; Sung, Kung-Bin

2018-04-20

An iterative curve fitting method has been applied in both simulation [J. Biomed. Opt.17, 107003 (2012)JBOPFO1083-366810.1117/1.JBO.17.10.107003] and phantom [J. Biomed. Opt.19, 077002 (2014)JBOPFO1083-366810.1117/1.JBO.19.7.077002] studies to accurately extract optical properties and the top layer thickness of a two-layered superficial tissue model from diffuse reflectance spectroscopy (DRS) data. This paper describes a hybrid two-step parameter estimation procedure to address two main issues of the previous method, including (1) high computational intensity and (2) converging to local minima. The parameter estimation procedure contained a novel initial estimation step to obtain an initial guess, which was used by a subsequent iterative fitting step to optimize the parameter estimation. A lookup table was used in both steps to quickly obtain reflectance spectra and reduce computational intensity. On simulated DRS data, the proposed parameter estimation procedure achieved high estimation accuracy and a 95% reduction of computational time compared to previous studies. Furthermore, the proposed initial estimation step led to better convergence of the following fitting step. Strategies used in the proposed procedure could benefit both the modeling and experimental data processing of not only DRS but also related approaches such as near-infrared spectroscopy.

Plane-Based Registration of Several Thousand Laser Scans on Standard Hardware

NASA Astrophysics Data System (ADS)

Wujanz, D.; Schaller, S.; Gielsdorf, F.; Gründig, L.

2018-05-01

The automatic registration of terrestrial laser scans appears to be a solved problem in science as well as in practice. However, this assumption is questionable especially in the context of large projects where an object of interest is described by several thousand scans. A critical issue inherently linked to this task is memory management especially if cloud-based registration approaches such as the ICP are being deployed. In order to process even thousands of scans on standard hardware a plane-based registration approach is applied. As a first step planar features are detected within the unregistered scans. This step drastically reduces the amount of data that has to be handled by the hardware. After determination of corresponding planar features a pairwise registration procedure is initiated based on a graph that represents topological relations among all scans. For every feature individual stochastic characteristics are computed that are consequently carried through the algorithm. Finally, a block adjustment is carried out that minimises the residuals between redundantly captured areas. The algorithm is demonstrated on a practical survey campaign featuring a historic town hall. In total, 4853 scans were registered on a standard PC with four processors (3.07 GHz) and 12 GB of RAM.

Telomeric 3′ overhangs derive from resection by Exo1 and Apollo and fill-in by POT1b-associated CST

PubMed Central

Wu, Peng; Takai, Hiroyuki; de Lange, Titia

2012-01-01

SUMMARY A 3′ overhang is critical for the protection and maintenance of mammalian telomeres. How these overhangs are generated and whether different processing steps modify telomeres synthesized by leading- and lagging-strand DNA replication was not known. Here we evaluate changes in the telomeric overhangs through the cell cycle and at leading- and lagging-end telomeres in mouse cells lacking relevant genes. Apollo, a nuclease bound to the shelterin subunit TRF2, initiated formation of the 3′ overhang at leading-, but not lagging-end telomeres. Hyper-resection by Apollo was blocked at both ends by the shelterin protein POT1b. Exo1 extensively resected both telomere ends, generating long 3′ overhangs that transiently occurred in S/G2. CST/AAF, a DNA polymeraseα. primase accessory factor related to yeast CST, bound POT1b and shortened the extended overhangs produced by Exo1, most likely through fill-in synthesis. The results establish 3′ overhang formation as a multi-step, shelterin-controlled process that ensures functional telomeric overhangs at all chromosome ends. PMID:22748632

Coordination of rapid stepping with arm pointing: anticipatory changes and step adaptation.

PubMed

Yiou, Eric; Schneider, Cyril; Roussel, Didier

2007-06-01

The present study explored whether rapid stepping is influenced by the coordination of an arm pointing task. Nine participants were instructed to (a) point the index finger of the dominant arm towards a target from the standing posture, (b) initiate a rapid forward step with the contralateral leg, and (c) synchronize stepping and pointing (combined task). Force plate and ankle muscle electromyography (EMG) recordings were contrasted between (b) and (c). In the combined task, the arm acceleration trace most often peaked around foot-off, coinciding with a 15% increase in the forward acceleration of the center of gravity (CoG). Backward displacement of the center of foot pressure at foot-off, duration of anticipatory postural adjustments (APAs) and ankle muscle EMG activity remained unchanged. In contrast, durations of swing phase and whole step were reduced and step length was smaller in the combined task. A reduction in the swing phase was correlated with an increased CoG forward acceleration at foot-off. Changes in the biomechanics of step initiation during the combined task might be ascribed to the postural dynamics elicited by arm pointing, and not to a modulation of the step APAs programming.

From Empathy to Critical Reflection: The Use of Testimonies in The Training of Holocaust Educators

ERIC Educational Resources Information Center

Bornstein, Lilach Naishtat; Naveh, Eyal

2018-01-01

How can we bridge the emotional and cognitive study of Holocaust testimonies in Israel? Can empathy be used as a stepping stone to critical reflection? And how can teachers address the manipulative popular interpretation of these testimonies in Israel, which seemingly place them beyond critical reflection? We examine these questions through an…

The Non-Transparency of the Self and the Ethical Value of Bildung

ERIC Educational Resources Information Center

Thompson, Christiane

2005-01-01

In the light of the modern idea of a sovereign and self-transparent subject, the paper evaluates the philosophical and ethical relevance of Bildung. As a first step, (the early) Nietzsche's and Adorno's criticism of Bildung is explicated, a criticism based upon the thinkers' critical stance towards the modern epistemological relation of subject…

Instructional Model of Critical Literacy in an EFL Context: Balancing Conventional and Critical Literacy

ERIC Educational Resources Information Center

Huh, Seonmin

2016-01-01

This article explores the general patterns of interactions between the teacher and students during the different instructional steps when the teacher attempted to incorporate both conventional skill-based reading and critical literacy in an English as a foreign language (EFL) literacy class in a Korean university. There has been a paucity of EFL…

Is Truthiness Enough? Classroom Activities for Encouraging Evidence-Based Critical Thinking

ERIC Educational Resources Information Center

Kraus, Sue; Sears, Sharon R.; Burke, Brian L.

2013-01-01

Teaching students how to think critically and develop lifelong habits of evidence-based inquiry outside of the classroom is a primary goal for educators today. This paper describes nine activities designed to promote evidence-based critical thinking in college or high school classrooms in any discipline. We have developed a seven step process for…

Conceptual and Critical Development in Student Teachers: First Steps towards an Integrated Comprehension of Osmosis

ERIC Educational Resources Information Center

Viennot, Laurence; Décamp, Nicolas

2016-01-01

This investigation is focused on possible links between the development of critical attitude and conceptual understanding. We conducted a fine grained analysis of five student teachers' critical and conceptual development during a one hour and a half interaction with an expert. This investigation completes a series of three previous studies…

Preparation of SS316L MIM feedstock with biopolymer as a binder

NASA Astrophysics Data System (ADS)

Abdullah, A. A.; Norita, H.; Azlina, H. N.; Sulong, A. B.; Mas'ood, N. N.

2018-01-01

This paper focus on feedstock preparation for SS316L metal injection molding (MIM) part. The primary step of feedstock preparation, critical powder loading determined by two method; maximum filled volume calculation model and torque analysis. The critical powder loading determined by calculation was 70 vol% to 77 vol% while for experimental approaches shows the value of 75 vol%. The feedstock was prepared by mixing SS316L powder and polymer binder with ratio 70:30 at 175 °C with speed of 50 rpm. The feedstock was analyzed by thermogravimetric analysis (TGA) and Scanning electron microscope (SEM). The composition for the feedstock after preparation step was confirmed by TGA. It was found that the prepared feedstock component was compatible to each other and composition is maintain along the mixing step.

Dual initiation strip charge apparatus and methods for making and implementing the same

DOEpatents

Jakaboski, Juan-Carlos [Albuquerque, NM; Todd,; Steven, N [Rio Rancho, NM; Polisar, Stephen [Albuquerque, NM; Hughs, Chance [Tijeras, NM

2011-03-22

A Dual Initiation Strip Charge (DISC) apparatus is initiated by a single initiation source and detonates a strip of explosive charge at two separate contacts. The reflection of explosively induced stresses meet and create a fracture and breach a target along a generally single fracture contour and produce generally fragment-free scattering and no spallation. Methods for making and implementing a DISC apparatus provide numerous advantages over previous methods of creating explosive charges by utilizing steps for rapid prototyping; by implementing efficient steps and designs for metering consistent, repeatable, and controlled amount of high explosive; and by utilizing readily available materials.

Boon and Bane of Inflammation in Bone Tissue Regeneration and Its Link with Angiogenesis.

PubMed

Schmidt-Bleek, Katharina; Kwee, Brian J; Mooney, David J; Duda, Georg N

2015-08-01

Delayed healing or nonhealing of bone is an important clinical concern. Although bone, one of the two tissues with scar-free healing capacity, heals in most cases, healing is delayed in more than 10% of clinical cases. Treatment of such delayed healing condition is often painful, risky, time consuming, and expensive. Tissue healing is a multistage regenerative process involving complex and well-orchestrated steps, which are initiated in response to injury. At best, these steps lead to scar-free tissue formation. At the onset of healing, during the inflammatory phase, stationary and attracted macrophages and other immune cells at the fracture site release cytokines in response to injury. This initial reaction to injury is followed by the recruitment, proliferation, and differentiation of mesenchymal stromal cells, synthesis of extracellular matrix proteins, angiogenesis, and finally tissue remodeling. Failure to heal is often associated with poor revascularization. Since blood vessels mediate the transport of circulating cells, oxygen, nutrients, and waste products, they appear essential for successful healing. The strategy of endogenous regeneration in a tissue such as bone is interesting to analyze since it may represent a blueprint of successful tissue formation. This review highlights the interdependency of the time cascades of inflammation, angiogenesis, and tissue regeneration. A better understanding of these inter-relations is mandatory to early identify patients at risk as well as to overcome critical clinical conditions that limit healing. Instead of purely tolerating the inflammatory phase, modulations of inflammation (immunomodulation) might represent a valid therapeutic strategy to enhance angiogenesis and foster later phases of tissue regeneration.

Reducing Bottlenecks to Improve the Efficiency of the Lung Cancer Care Delivery Process: A Process Engineering Modeling Approach to Patient-Centered Care.

PubMed

Ju, Feng; Lee, Hyo Kyung; Yu, Xinhua; Faris, Nicholas R; Rugless, Fedoria; Jiang, Shan; Li, Jingshan; Osarogiagbon, Raymond U

2017-12-01

The process of lung cancer care from initial lesion detection to treatment is complex, involving multiple steps, each introducing the potential for substantial delays. Identifying the steps with the greatest delays enables a focused effort to improve the timeliness of care-delivery, without sacrificing quality. We retrospectively reviewed clinical events from initial detection, through histologic diagnosis, radiologic and invasive staging, and medical clearance, to surgery for all patients who had an attempted resection of a suspected lung cancer in a community healthcare system. We used a computer process modeling approach to evaluate delays in care delivery, in order to identify potential 'bottlenecks' in waiting time, the reduction of which could produce greater care efficiency. We also conducted 'what-if' analyses to predict the relative impact of simulated changes in the care delivery process to determine the most efficient pathways to surgery. The waiting time between radiologic lesion detection and diagnostic biopsy, and the waiting time from radiologic staging to surgery were the two most critical bottlenecks impeding efficient care delivery (more than 3 times larger compared to reducing other waiting times). Additionally, instituting surgical consultation prior to cardiac consultation for medical clearance and decreasing the waiting time between CT scans and diagnostic biopsies, were potentially the most impactful measures to reduce care delays before surgery. Rigorous computer simulation modeling, using clinical data, can provide useful information to identify areas for improving the efficiency of care delivery by process engineering, for patients who receive surgery for lung cancer.

Planning for Growth.

ERIC Educational Resources Information Center

Astle, Judy Hughes

2001-01-01

A summer camp expanded into year-round operation one step at a time. Initial steps included identifying the camp mission, history, and assets. Successive steps became larger and included expanding the program within the mission, increasing marketing efforts, developing natural resources, creating plans for maintenance and improvements, and…

Electrification in winter storms and the analysis of thunderstorm overflight data

NASA Technical Reports Server (NTRS)

Brook, Marx

1993-01-01

We have been focusing our study of electrification in winter storms on the lightning initiation process, making inferences about the magnitude of the electric fields from the initial pulses associated with breakdown, i.e., with the formation of the initial streamers. The essence of the most significant finding is as follows: (1) initial breakdown radiation pulses from stepped leaders prior to the first return stroke are very large, reaching values of 20-30 Volts/meter, comparable to return stroke radiation; and (2) the duration of the stepped leader, from the initial detectable radiation pulse to the return stroke onset, is very-short-ranging from a minimum 1.5 ms to a maximum of 4.5 ms. This past summer (June-August of 1991) we participated in the CAPE program at the Kennedy Space Center in order to acquire data on stepped leaders in summer storms with the same equipment used to get the winter storm data. We discovered that the vigorous leaders seen in winter so frequently were present in summer storms, although not as large in amplitude and certainly not as frequent.

24 CFR Appendix E to Part 3500 - Arithmetic Steps

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Arithmetic Steps E Appendix E to...—Arithmetic Steps I. Example Illustrating Aggregate Analysis: ASSUMPTIONS: Disbursements: $360 for school... Payment: July 1 Step 1—Initial Trial Balance Aggregate pmt disb bal Jun 0 0 0 Jul 130 500 −370 Aug 130 0...

The effect of different screw-tightening techniques on the stress generated on an internal-connection implant superstructure.

PubMed

Choi, Jung-Han; Lim, Young-Jun; Kim, Chang-Whe; Kim, Myung-Joo

2009-01-01

This study evaluated the effect of different screw-tightening sequences, forces, and methods on the stresses generated on a well-fitting internal-connection implant (Astra Tech) superstructure. A metal framework directly connected to four parallel implants was fabricated on a fully edentulous mandibular resin model. Six stone casts with four implant replicas were made from a pickup impression of the superstructure to represent a "well-fitting" situation. Stresses generated by four screw-tightening sequences (1-2-3-4, 4-3-2-1, 2-4-3-1, and 2-3-1-4), two forces (10 and 20 Ncm), and two methods (one-step and two-step) were evaluated. In the two-step method, screws were tightened to the initial torque (10 Ncm) in a predetermined screw-tightening sequence and then to the final torque (20 Ncm) in the same sequence. Stresses were recorded twice by three strain gauges attached to the framework (superior face midway between abutments). Deformation data were analyzed using multiple analysis of variance at a .05 level of statistical significance. In all stone casts, stresses were produced by the superstructure connection, regardless of screw-tightening sequence, force, and method. No statistically significant differences for superstructure preload stresses were found based on screw-tightening sequences (-180.0 to -181.6 microm/m) or forces (-163.4 and -169.2 microm/m) (P > .05). However, different screw-tightening methods induced different stresses on the superstructure. The two-step screw-tightening method (-180.1 microm/m) produced significantly higher stress than the one-step method (-169.2 microm/m) (P = .0457). Within the limitations of this in vitro study, screw-tightening sequence and force were not critical factors in the stress generated on a well-fitting internal-connection implant superstructure. The stress caused by the two-step method was greater than that produced using the one-step method. Further studies are needed to evaluate the effect of screw-tightening techniques on preload stress in various different clinical situations.

The Neuro-Mechanical Processes That Underlie Goal-Directed Medio-Lateral APA during Gait Initiation.

PubMed

Honeine, Jean-Louis; Schieppati, Marco; Crisafulli, Oscar; Do, Manh-Cuong

2016-01-01

Gait initiation (GI) involves passing from bipedal to unipedal stance. It requires a rapid movement of the center of foot pressure (CoP) towards the future swing foot and of the center of mass (CoM) in the direction of the stance foot prior to the incoming step. This anticipatory postural adjustment (APA) allows disengaging the swing leg from the ground and establishing favorable conditions for stepping. This study aimed to describe the neuro-mechanical process that underlies the goal-directed medio-lateral (ML) APA. We hypothesized that controlled knee flexion of the stance leg contributes to the initial ML displacement of the CoP and to the calibration of the first step. Fourteen subjects initiated gait starting from three different initial stance widths of 15 cm (Small), 30 cm (Medium), and 45 cm (Large). Optoelectronic, force platform and electromyogram (EMG) measurements were performed. During APA, soleus activity diminished bilaterally, while tibialis anterior (TA) activity increased, more so in the stance leg than in the swing leg, and to a larger extent with increasing initial stance width. Knee flexion of the stance leg was observed during APA and correlated with the ML CoP displacement towards the swing leg. ML CoP and CoM displacements during APA increased with increasing stance width. The activity of stance-leg TA was correlated with the degree of knee flexion. Swing-leg tensor fasciae latae (TFL) was also active during APA. Across subjects, when stance-leg tibialis activity was low, TFL activity was large and vice versa. The modulation of the ML CoP position during APA allowed the gravity-driven torque to place the CoM just lateral to the stance foot during step execution. Accordingly, the gravity-driven torque, the ML CoM velocity during step execution, and the step width at foot contact (FC) were lower in the Small and greater in the Large condition. Consequently, the position of the stepping foot at FC remained close to the sagittal plane in all three conditions. Conclusively, coordinated activation of hip abductors and ankle dorsiflexors during APA displaces the CoP towards the swing leg, and sets the contact position for the swing foot.

The Neuro-Mechanical Processes That Underlie Goal-Directed Medio-Lateral APA during Gait Initiation

PubMed Central

Honeine, Jean-Louis; Schieppati, Marco; Crisafulli, Oscar; Do, Manh-Cuong

2016-01-01

Gait initiation (GI) involves passing from bipedal to unipedal stance. It requires a rapid movement of the center of foot pressure (CoP) towards the future swing foot and of the center of mass (CoM) in the direction of the stance foot prior to the incoming step. This anticipatory postural adjustment (APA) allows disengaging the swing leg from the ground and establishing favorable conditions for stepping. This study aimed to describe the neuro-mechanical process that underlies the goal-directed medio-lateral (ML) APA. We hypothesized that controlled knee flexion of the stance leg contributes to the initial ML displacement of the CoP and to the calibration of the first step. Fourteen subjects initiated gait starting from three different initial stance widths of 15 cm (Small), 30 cm (Medium), and 45 cm (Large). Optoelectronic, force platform and electromyogram (EMG) measurements were performed. During APA, soleus activity diminished bilaterally, while tibialis anterior (TA) activity increased, more so in the stance leg than in the swing leg, and to a larger extent with increasing initial stance width. Knee flexion of the stance leg was observed during APA and correlated with the ML CoP displacement towards the swing leg. ML CoP and CoM displacements during APA increased with increasing stance width. The activity of stance-leg TA was correlated with the degree of knee flexion. Swing-leg tensor fasciae latae (TFL) was also active during APA. Across subjects, when stance-leg tibialis activity was low, TFL activity was large and vice versa. The modulation of the ML CoP position during APA allowed the gravity-driven torque to place the CoM just lateral to the stance foot during step execution. Accordingly, the gravity-driven torque, the ML CoM velocity during step execution, and the step width at foot contact (FC) were lower in the Small and greater in the Large condition. Consequently, the position of the stepping foot at FC remained close to the sagittal plane in all three conditions. Conclusively, coordinated activation of hip abductors and ankle dorsiflexors during APA displaces the CoP towards the swing leg, and sets the contact position for the swing foot. PMID:27642280

Soliton radiation beat analysis of optical pulses generated from two continuous-wave lasers

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

Zajnulina, M.; Giannone, D.; Haynes, R.

We propose a fibre-based approach for generation of optical frequency combs (OFCs) with the aim of calibration of astronomical spectrographs in the low and medium-resolution range. This approach includes two steps: in the first step, an appropriate state of optical pulses is generated and subsequently moulded in the second step delivering the desired OFC. More precisely, the first step is realised by injection of two continuous-wave (CW) lasers into a conventional single-mode fibre, whereas the second step generates a broad OFC by using the optical solitons generated in step one as initial condition. We investigate the conversion of a bichromaticmore » input wave produced by two initial CW lasers into a train of optical solitons, which happens in the fibre used as step one. Especially, we are interested in the soliton content of the pulses created in this fibre. For that, we study different initial conditions (a single cosine-hump, an Akhmediev breather, and a deeply modulated bichromatic wave) by means of soliton radiation beat analysis and compare the results to draw conclusion about the soliton content of the state generated in the first step. In case of a deeply modulated bichromatic wave, we observed the formation of a collective soliton crystal for low input powers and the appearance of separated solitons for high input powers. An intermediate state showing the features of both, the soliton crystal and the separated solitons, turned out to be most suitable for the generation of OFC for the purpose of calibration of astronomical spectrographs.« less

Soliton radiation beat analysis of optical pulses generated from two continuous-wave lasers.

PubMed

Zajnulina, M; Böhm, M; Blow, K; Rieznik, A A; Giannone, D; Haynes, R; Roth, M M

2015-10-01

We propose a fibre-based approach for generation of optical frequency combs (OFCs) with the aim of calibration of astronomical spectrographs in the low and medium-resolution range. This approach includes two steps: in the first step, an appropriate state of optical pulses is generated and subsequently moulded in the second step delivering the desired OFC. More precisely, the first step is realised by injection of two continuous-wave (CW) lasers into a conventional single-mode fibre, whereas the second step generates a broad OFC by using the optical solitons generated in step one as initial condition. We investigate the conversion of a bichromatic input wave produced by two initial CW lasers into a train of optical solitons, which happens in the fibre used as step one. Especially, we are interested in the soliton content of the pulses created in this fibre. For that, we study different initial conditions (a single cosine-hump, an Akhmediev breather, and a deeply modulated bichromatic wave) by means of soliton radiation beat analysis and compare the results to draw conclusion about the soliton content of the state generated in the first step. In case of a deeply modulated bichromatic wave, we observed the formation of a collective soliton crystal for low input powers and the appearance of separated solitons for high input powers. An intermediate state showing the features of both, the soliton crystal and the separated solitons, turned out to be most suitable for the generation of OFC for the purpose of calibration of astronomical spectrographs.

Soliton radiation beat analysis of optical pulses generated from two continuous-wave lasers

NASA Astrophysics Data System (ADS)

Zajnulina, M.; Böhm, M.; Blow, K.; Rieznik, A. A.; Giannone, D.; Haynes, R.; Roth, M. M.

2015-10-01

We propose a fibre-based approach for generation of optical frequency combs (OFCs) with the aim of calibration of astronomical spectrographs in the low and medium-resolution range. This approach includes two steps: in the first step, an appropriate state of optical pulses is generated and subsequently moulded in the second step delivering the desired OFC. More precisely, the first step is realised by injection of two continuous-wave (CW) lasers into a conventional single-mode fibre, whereas the second step generates a broad OFC by using the optical solitons generated in step one as initial condition. We investigate the conversion of a bichromatic input wave produced by two initial CW lasers into a train of optical solitons, which happens in the fibre used as step one. Especially, we are interested in the soliton content of the pulses created in this fibre. For that, we study different initial conditions (a single cosine-hump, an Akhmediev breather, and a deeply modulated bichromatic wave) by means of soliton radiation beat analysis and compare the results to draw conclusion about the soliton content of the state generated in the first step. In case of a deeply modulated bichromatic wave, we observed the formation of a collective soliton crystal for low input powers and the appearance of separated solitons for high input powers. An intermediate state showing the features of both, the soliton crystal and the separated solitons, turned out to be most suitable for the generation of OFC for the purpose of calibration of astronomical spectrographs.

Critical pathogenic steps to high risk Helicobacter pylori gastritis and gastric carcinogenesis

PubMed Central

Lee, Inchul

2014-01-01

Helicobacter pylori (H. pylori) gastritis may progress to high risk gastropathy and cancer. However, the pathological progression has not been characterized in detail. H. pylori induce persistent inflammatory infiltration. Neutrophils are unique in that they directly infiltrate into foveolar epithelium aiming the proliferative zone specifically. Neutrophilic proliferative zone foveolitis is a critical pathogenic step in H. pylori gastritis inducing intensive epithelial damage. Epithelial cells carrying accumulated genomic damage and mutations show the Malgun (clear) cell change, characterized by large clear nucleus and prominent nucleolus. Malgun cells further undergo atypical changes, showing nuclear folding, coarse chromatin, and multiple nucleoli. The atypical Malgun cell (AMC) change is a novel premalignant condition in high risk gastropathy, which may progress and undergo malignant transformation directly. The pathobiological significance of AMC in gastric carcinogenesis is reviewed. A new diagnosis system of gastritis is proposed based on the critical pathologic steps classifying low and high risk gastritis for separate treatment modality. It is suggested that the regulation of H. pylori-induced neutrophilic foveolitis might be a future therapeutic goal replacing bactericidal antibiotics approach. PMID:24914362

Critical pathogenic steps to high risk Helicobacter pylori gastritis and gastric carcinogenesis.

PubMed

Lee, Inchul

2014-06-07

Helicobacter pylori (H. pylori) gastritis may progress to high risk gastropathy and cancer. However, the pathological progression has not been characterized in detail. H. pylori induce persistent inflammatory infiltration. Neutrophils are unique in that they directly infiltrate into foveolar epithelium aiming the proliferative zone specifically. Neutrophilic proliferative zone foveolitis is a critical pathogenic step in H. pylori gastritis inducing intensive epithelial damage. Epithelial cells carrying accumulated genomic damage and mutations show the Malgun (clear) cell change, characterized by large clear nucleus and prominent nucleolus. Malgun cells further undergo atypical changes, showing nuclear folding, coarse chromatin, and multiple nucleoli. The atypical Malgun cell (AMC) change is a novel premalignant condition in high risk gastropathy, which may progress and undergo malignant transformation directly. The pathobiological significance of AMC in gastric carcinogenesis is reviewed. A new diagnosis system of gastritis is proposed based on the critical pathologic steps classifying low and high risk gastritis for separate treatment modality. It is suggested that the regulation of H. pylori-induced neutrophilic foveolitis might be a future therapeutic goal replacing bactericidal antibiotics approach.

Q-Sample Construction: A Critical Step for a Q-Methodological Study.

PubMed

Paige, Jane B; Morin, Karen H

2016-01-01

Q-sample construction is a critical step in Q-methodological studies. Prior to conducting Q-studies, researchers start with a population of opinion statements (concourse) on a particular topic of interest from which a sample is drawn. These sampled statements are known as the Q-sample. Although literature exists on methodological processes to conduct Q-methodological studies, limited guidance exists on the practical steps to reduce the population of statements to a Q-sample. A case exemplar illustrates the steps to construct a Q-sample in preparation for a study that explored perspectives nurse educators and nursing students hold about simulation design. Experts in simulation and Q-methodology evaluated the Q-sample for readability, clarity, and for representativeness of opinions contained within the concourse. The Q-sample was piloted and feedback resulted in statement refinement. Researchers especially those undertaking Q-method studies for the first time may benefit from the practical considerations to construct a Q-sample offered in this article. © The Author(s) 2014.

Fabrication of Optimized Superconducting Phase Inverters Based on Superconductor-Ferromagnet-Superconductor pi π -Junctions

NASA Astrophysics Data System (ADS)

Bolginov, V. V.; Rossolenko, A. N.; Shkarin, A. B.; Oboznov, V. A.; Ryazanov, V. V.

2018-03-01

We have implemented a trilayer technological approach to fabricate Nb-Cu_{0.47} Ni_{0.53}-Nb superconducting phase inverters (π -junctions) with enhanced critical current. Within this technique, all three layers of the superconductor-ferromagnet-superconductor junction deposited in a single vacuum cycle that have allowed us to obtain π -junctions with critical current density up to 20 kA/cm^2. The value achieved is a factor of 10 higher than for the step-by-step method used in earlier works. Our additional experiments have shown that this difference is related to a bilayered CuNi/Cu barrier used in the case of the step-by-step technique and interlayer diffusion at the CuNi/Cu interface. We show that the interlayer diffusion can be utilized for fine tuning of the 0{-}π transition temperature of already fabricated junctions. The results obtained open new opportunities for the CuNi-based phase inverters in digital and quantum Josephson electronics.

Transoral endoscopic anatomy of the parapharyngeal space: a step-by-step logical approach with surgical considerations.

PubMed

Dallan, Iacopo; Seccia, Veronica; Muscatello, Luca; Lenzi, Riccardo; Castelnuovo, Paolo; Bignami, Maurizio; Montevecchi, Filippo; Tschabitscher, Manfred; Vicini, Claudio

2011-04-01

Surgical approaches to the parapharyngeal spaces are challenging. Little is known about the transoral perspective of the anatomy of the parapharyngeal space. Thus, transoral approaches are seldom performed, and only for small-sized tumors. Six freshly injected cadaver heads were dissected to illustrate the transoral surgical anatomy of the parapharyngeal space. The transoral window dominates the parapharyngeal space from the medial pterygoid muscle laterally to the superior constrictor muscle medially. The stylopharyngeus and styloglossus muscles seem to be critical landmarks in this approach. Posterior to these muscles and laterally to the superior constrictor muscle, the internal carotid artery, internal jugular vein, and lower cranial nerves are identifiable. This anatomic study emphasizes the critical role of the superior constrictor, styloglossus, and stylopharyngeus muscles and highlights the concept of a logical step by step technique that allows the identification of important structures and the creation of safe surgical corridors. Copyright © 2010 Wiley Periodicals, Inc.

A Practical Risk Assessment Methodology for Safety-Critical Train Control Systems

DOT National Transportation Integrated Search

2009-07-01

This project proposes a Practical Risk Assessment Methodology (PRAM) for analyzing railroad accident data and assessing the risk and benefit of safety-critical train control systems. This report documents in simple steps the algorithms and data input...

THE EFFECT OF STEP RATE MANIPULATION ON FOOT STRIKE PATTERN OF LONG DISTANCE RUNNERS.

PubMed

Allen, Darrell J; Heisler, Hollie; Mooney, Jennifer; Kring, Richard

2016-02-01

Running gait retraining to change foot strike pattern in runners from a heel strike pattern to a non heel- strike pattern has been shown to reduce impact forces and may help to reduce running related injuries. Step rate manipulation above preferred is known to help decrease step length, foot inclination angle, and vertical mass excursion, but has not yet been evaluated as a method to change foot strike pattern. The purpose of this study was to investigate the effect of step rate manipulation on foot strike pattern in shod recreational runners who run with a heel strike pattern. A secondary purpose was to describe the effect of step rate manipulation at specific percentages above preferred on foot inclination angle at initial contact. Forty volunteer runners, who were self-reported heel strikers and had a weekly running mileage of at least 10 miles, were recruited. Runners were confirmed to be heel strikers during the warm up period on the treadmill. The subject's step rate was determined at their preferred running pace. A metronome was used to increase step rate above the preferred step rate by 5%, 10% and 15%. 2D video motion analysis was utilized to determine foot strike pattern and to measure foot inclination angle at initial contact for each step rate condition. There was a statistically significant change in foot strike pattern from a heel strike pattern to a mid-foot or forefoot strike pattern at both 10% and 15% step rates above preferred. Seven of the 40 subjects (17.5%) changed from a heel- strike pattern to a non- heel strike pattern at +10% and 12 of the 40 subjects (30%) changed to a non-heel strike pattern at +15%. Mean foot inclination angle at initial contact showed a statistically significant change (reduction) as step rate increased. Step rate manipulation of 10% or greater may be enough to change foot strike pattern from a heel strike to a mid-foot or forefoot strike pattern in a small percentage of recreational runners who run in traditional running shoes. If changing the foot strike pattern is the main goal, other gait re-training methods may be needed to make a change from a heel strike to a non-heel strike pattern. Step rate manipulation shows a progressive reduction of foot inclination angle at 5%, 10%, and 15% above preferred step rate which reduces the severity of the heel strike at initial contact. Step rate manipulation of at least +10% above preferred may be an effective running gait retraining method for clinicians to decrease the severity of heel strike and possibly assist a runner to change to a non-heel strike pattern. 3.

On the critical flame radius and minimum ignition energy for spherical flame initiation

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

Chen, Zheng; Burke, M. P.; Ju, Yiguang

2011-01-01

Spherical flame initiation from an ignition kernel is studied theoretically and numerically using different fuel/oxygen/helium/argon mixtures (fuel: hydrogen, methane, and propane). The emphasis is placed on investigating the critical flame radius controlling spherical flame initiation and its correlation with the minimum ignition energy. It is found that the critical flame radius is different from the flame thickness and the flame ball radius and that their relationship depends strongly on the Lewis number. Three different flame regimes in terms of the Lewis number are observed and a new criterion for the critical flame radius is introduced. For mixtures with Lewis numbermore » larger than a critical Lewis number above unity, the critical flame radius is smaller than the flame ball radius but larger than the flame thickness. As a result, the minimum ignition energy can be substantially over-predicted (under-predicted) based on the flame ball radius (the flame thickness). The results also show that the minimum ignition energy for successful spherical flame initiation is proportional to the cube of the critical flame radius. Furthermore, preferential diffusion of heat and mass (i.e. the Lewis number effect) is found to play an important role in both spherical flame initiation and flame kernel evolution after ignition. It is shown that the critical flame radius and the minimum ignition energy increase significantly with the Lewis number. Therefore, for transportation fuels with large Lewis numbers, blending of small molecule fuels or thermal and catalytic cracking will significantly reduce the minimum ignition energy.« less

A Rapid Method of Isolating Neoantigen-specific T Cell Receptor Sequences | NCI Technology Transfer Center | TTC

Cancer.gov

Recent research has demonstrated that neoantigen-specific T-cell receptors (TCRs) can be isolated from a cancer patient’s lymphocytes. These TCRs may be used to engineer populations of tumor-reactive T cells for cancer immunotherapies. Obtaining sequences of these functional TCRs is a critical initial step in preparing this type of personalized cancer treatment; however, current methods are time-consuming and labor-intensive. Scientists at the National Cancer Institute (NCI) have developed a rapid and robust method of isolating the sequences of mutation-specific TCRs to alleviate these issues; they seek licensing and/or co-development research collaborations for the development of a method for isolating the sequences of tumor-reactive TCRs. For collaboration opportunities, please contact Steven A. Rosenberg, M.D., Ph.D. at sar@nih.gov.

National Facilities Study. Volume 1: Facilities Inventory

NASA Technical Reports Server (NTRS)

1994-01-01

The inventory activity was initiated to solve the critical need for a single source of site specific descriptive and parametric data on major public and privately held aeronautics and aerospace related facilities. This a challenging undertaking due to the scope of the effort and the short lead time in which to assemble the inventory and have it available to support the task group study needs. The inventory remains dynamic as sites are being added and the data is accessed and refined as the study progresses. The inventory activity also included the design and implementation of a computer database and analytical tools to simplify access to the data. This volume describes the steps which were taken to define the data requirements, select sites, and solicit and acquire data from them. A discussion of the inventory structure and analytical tools is also provided.

Exploring the Requisite Skills and Competencies of Pharmacists Needed for Success in an Evolving Health Care Environment.

PubMed

McLaughlin, Jacqueline E; Bush, Antonio A; Rodgers, Philip T; Scott, Mollie Ashe; Zomorodi, Meg; Pinelli, Nicole R; Roth, Mary T

2017-08-01

Objective. To identify and describe the core competencies and skills considered essential for success of pharmacists in today's rapidly evolving health care environment. Methods. Six breakout groups of 15-20 preceptors, pharmacists, and partners engaged in a facilitated discussion about the qualities and characteristics relevant to the success of a pharmacy graduate. Data were analyzed using qualitative methods. Peer-debriefing, multiple coders, and member-checking were used to promote trustworthiness of findings. Results. Eight overarching themes were identified: critical thinking and problem solving; collaboration across networks and leading by influence; agility and adaptability; initiative and entrepreneurialism; effective oral and written communication; accessing and analyzing information; curiosity and imagination; and self-awareness. Conclusion. This study is an important step toward understanding how to best prepare pharmacy students for the emerging health care needs of society.

The Daniel K. Inouye College of Pharmacy Scripts: Precision Medicine Through the Use of Pharmacogenomics: Current Status and Barriers to Implementation.

PubMed

Ciarleglio, Anita E; Ma, Carolyn

2017-09-01

The precision medicine initiative brought forth by President Barack Obama in 2015 is an important step on the journey to truly personalized medicine. A broad knowledge and understanding of the implications of the pharmacogenomic literature will be critical to the achievement of this goal. While a great amount of data has been published in the areas of pharmacogenomics and pharmacogenetics, there are still relatively few instances in which the need for clinical intervention can be stated without doubt, and which are widely accepted and practiced by the medical community. As our knowledge base rapidly expands, issues such as insurance reimbursement for genetic testing and education of the health care workforce will be paramount to achieving the goal of precision medicine for all patients.

Tumour-derived SPARC drives vascular permeability and extravasation through endothelial VCAM1 signalling to promote metastasis.

PubMed

Tichet, Mélanie; Prod'Homme, Virginie; Fenouille, Nina; Ambrosetti, Damien; Mallavialle, Aude; Cerezo, Michael; Ohanna, Mickaël; Audebert, Stéphane; Rocchi, Stéphane; Giacchero, Damien; Boukari, Fériel; Allegra, Maryline; Chambard, Jean-Claude; Lacour, Jean-Philippe; Michiels, Jean-François; Borg, Jean-Paul; Deckert, Marcel; Tartare-Deckert, Sophie

2015-04-30

Disruption of the endothelial barrier by tumour-derived secreted factors is a critical step in cancer cell extravasation and metastasis. Here, by comparative proteomic analysis of melanoma secretomes, we identify the matricellular protein SPARC as a novel tumour-derived vascular permeability factor. SPARC deficiency abrogates tumour-initiated permeability of lung capillaries and prevents extravasation, whereas SPARC overexpression enhances vascular leakiness, extravasation and lung metastasis. SPARC-induced paracellular permeability is dependent on the endothelial VCAM1 receptor and p38 MAPK signalling. Blocking VCAM1 impedes melanoma-induced endothelial permeability and extravasation. The clinical relevance of our findings is highlighted by high levels of SPARC detected in tumour from human pulmonary melanoma lesions. Our study establishes tumour-produced SPARC and VCAM1 as regulators of cancer extravasation, revealing a novel targetable interaction for prevention of metastasis.

Optochemical Control of Protein Localization and Activity within Cell-like Compartments.

PubMed

Caldwell, Reese M; Bermudez, Jessica G; Thai, David; Aonbangkhen, Chanat; Schuster, Benjamin S; Courtney, Taylor; Deiters, Alexander; Hammer, Daniel A; Chenoweth, David M; Good, Matthew C

2018-05-08

We report inducible dimerization strategies for controlling protein positioning, enzymatic activity, and organelle assembly inside synthetic cell-like compartments upon photostimulation. Using a photocaged TMP-Haloligand compound, we demonstrate small molecule and light-induced dimerization of DHFR and Haloenzyme to localize proteins to a compartment boundary and reconstitute tripartite sfGFP assembly. Using photocaged rapamycin and fragments of split TEV protease fused to FRB and FKBP, we establish optical triggering of protease activity inside cell-size compartments. We apply light-inducible protease activation to initiate assembly of membraneless organelles, demonstrating the applicability of these tools for characterizing cell biological processes in vitro. This modular toolkit, which affords spatial and temporal control of protein function in a minimal cell-like system, represents a critical step toward the reconstitution of a tunable synthetic cell, built from the bottom up.

Toward a methodology for moral decision making in medicine.

PubMed

Kushner, T; Belliotti, R A; Buckner, D

1991-12-01

The failure of medical codes to provide adequate guidance for physicians' moral dilemmas points to the fact that some rules of analysis, informed by moral theory, are needed to assist in resolving perplexing ethical problems occurring with increasing frequency as medical technology advances. Initially, deontological and teleological theories appear more helpful, but criticisms can be lodged against both, and neither proves to be sufficient in itself. This paper suggests that to elude the limitations of previous approaches, a method of moral decision making must be developed incorporating both coherence methodology and some independently supported theoretical foundations. Wide Reflective Equilibrium is offered, and its process described along with a theory of the person which is used to animate the process. Steps are outlined to be used in the process, leading to the application of the method to an actual case.

Timing and Targeting of Treatment in Left Ventricular Hypertrophy.

PubMed

Nam, Deokhwa; Reineke, Erin L

2017-01-01

In most clinical cases, left ventricular hypertrophy (LVH) occurs over time from persistent cardiac stress. At the molecular level, this results in both transient and long-term changes to metabolic, sarcomeric, ion handling, and stress signaling pathways. Although this is initially an adaptive change, the mechanisms underlying LVH eventually lead to maladaptive changes including fibrosis, decreased cardiac function, and failure. Understanding the regulators of long-term changes, which are largely driven by transcriptional remodeling, is a crucial step in identifying novel therapeutic targets for preventing the downstream negative effects of LVH and treatments that could reverse or prevent it. The development of effective therapeutics, however, will require a critical understanding of what to target, how to modify important pathways, and how to identify the stage of pathology in which a specific treatment should be used.

Cell nuclei segmentation in fluorescence microscopy images using inter- and intra-region discriminative information.

PubMed

Song, Yang; Cai, Weidong; Feng, David Dagan; Chen, Mei

2013-01-01

Automated segmentation of cell nuclei in microscopic images is critical to high throughput analysis of the ever increasing amount of data. Although cell nuclei are generally visually distinguishable for human, automated segmentation faces challenges when there is significant intensity inhomogeneity among cell nuclei or in the background. In this paper, we propose an effective method for automated cell nucleus segmentation using a three-step approach. It first obtains an initial segmentation by extracting salient regions in the image, then reduces false positives using inter-region feature discrimination, and finally refines the boundary of the cell nuclei using intra-region contrast information. This method has been evaluated on two publicly available datasets of fluorescence microscopic images with 4009 cells, and has achieved superior performance compared to popular state of the art methods using established metrics.

Re-Imagining Initial Multiracial Teacher Education (IMTE) Model through the ODL Philosophy: A Critical Qualitative Meta-Synthesis Study

ERIC Educational Resources Information Center

Nyoni, J.

2012-01-01

This article reports on a critical meta-analysis of empirical studies done by human sciences researchers on the initial multicultural teacher education (IMTE) models in multicultural post-colonial transitional societies with reference to sub-Saharan African states in general and South Africa in particular. Using a critical post-positivist…

Nanopore sequencing technology and tools for genome assembly: computational analysis of the current state, bottlenecks and future directions.

PubMed

Senol Cali, Damla; Kim, Jeremie S; Ghose, Saugata; Alkan, Can; Mutlu, Onur

2018-04-02

Nanopore sequencing technology has the potential to render other sequencing technologies obsolete with its ability to generate long reads and provide portability. However, high error rates of the technology pose a challenge while generating accurate genome assemblies. The tools used for nanopore sequence analysis are of critical importance, as they should overcome the high error rates of the technology. Our goal in this work is to comprehensively analyze current publicly available tools for nanopore sequence analysis to understand their advantages, disadvantages and performance bottlenecks. It is important to understand where the current tools do not perform well to develop better tools. To this end, we (1) analyze the multiple steps and the associated tools in the genome assembly pipeline using nanopore sequence data, and (2) provide guidelines for determining the appropriate tools for each step. Based on our analyses, we make four key observations: (1) the choice of the tool for basecalling plays a critical role in overcoming the high error rates of nanopore sequencing technology. (2) Read-to-read overlap finding tools, GraphMap and Minimap, perform similarly in terms of accuracy. However, Minimap has a lower memory usage, and it is faster than GraphMap. (3) There is a trade-off between accuracy and performance when deciding on the appropriate tool for the assembly step. The fast but less accurate assembler Miniasm can be used for quick initial assembly, and further polishing can be applied on top of it to increase the accuracy, which leads to faster overall assembly. (4) The state-of-the-art polishing tool, Racon, generates high-quality consensus sequences while providing a significant speedup over another polishing tool, Nanopolish. We analyze various combinations of different tools and expose the trade-offs between accuracy, performance, memory usage and scalability. We conclude that our observations can guide researchers and practitioners in making conscious and effective choices for each step of the genome assembly pipeline using nanopore sequence data. Also, with the help of bottlenecks we have found, developers can improve the current tools or build new ones that are both accurate and fast, to overcome the high error rates of the nanopore sequencing technology.

Integrating medical informatics into the medical undergraduate curriculum.

PubMed

Khonsari, L S; Fabri, P J

1997-01-01

The advent of healthcare reform and the rapid application of new technologies have resulted in a paradigm shift in medical practice. Integrating medical Informatics into the full spectrum of medical education is a viral step toward implementing this new instructional model, a step required for the understanding and practice of modern medicine. We have developed an informatics curriculum, a new educational paradigm, and an intranet-based teaching module which are designed to enhance adult-learning principles, life-long self education, and evidence-based critical thinking. Thirty two, fourth year medical students have participated in a one month, full time, independent study focused on but not limited to four topics: mastering the windows-based environment, understanding hospital based information management systems, developing competence in using the internet/intranet and world wide web/HTML, and experiencing distance communication and TeleVideo networks. Each student has completed a clinically relevant independent study project utilizing technology mastered during the course. This initial curriculum offering was developed in conjunction with faculty from the College of Medicine, College of Engineering, College of Education, College of Business, College of Public Health. Florida Center of Instructional Technology, James A. Haley Veterans Hospital, Moffitt Cancer Center, Tampa General Hospital, GTE, Westshore Walk-in Clinic (paperless office), and the Florida Engineering Education Delivery System. Our second step toward the distributive integration process was the introduction of Medical Informatics to first, second and third year medical students. To date, these efforts have focused on undergraduate medical education. Our next step is to offer workshops in Informatics to college of medicine faculty, to residents in post graduate training programs (GME), and ultimately as a method of distance learning in continuing medical education (CME).

New Reduced Two-Time Step Method for Calculating Combustion and Emission Rates of Jet-A and Methane Fuel With and Without Water Injection

NASA Technical Reports Server (NTRS)

Molnar, Melissa; Marek, C. John

2004-01-01

A simplified kinetic scheme for Jet-A, and methane fuels with water injection was developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) or even simple FORTRAN codes that are being developed at Glenn. The two time step method is either an initial time averaged value (step one) or an instantaneous value (step two). The switch is based on the water concentration in moles/cc of 1x10(exp -20). The results presented here results in a correlation that gives the chemical kinetic time as two separate functions. This two step method is used as opposed to a one step time averaged method previously developed to determine the chemical kinetic time with increased accuracy. The first time averaged step is used at the initial times for smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, initial water to fuel mass ratio, temperature, and pressure. The second instantaneous step, to be used with higher water concentrations, gives the chemical kinetic time as a function of instantaneous fuel and water mole concentration, pressure and temperature (T4). The simple correlations would then be compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates were then used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide and NOx were obtained for Jet-A fuel and methane with and without water injection to water mass loadings of 2/1 water to fuel. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentrations of carbon monoxide and nitrogen oxide as functions of overall equivalence ratio, water to fuel mass ratio, pressure and temperature (T3). The temperature of the gas entering the turbine (T4) was also correlated as a function of the initial combustor temperature (T3), equivalence ratio, water to fuel mass ratio, and pressure.

Academic Provenance: Mapping Geoscience Students' Academic Pathways to their Career Trajectories

NASA Astrophysics Data System (ADS)

Houlton, H. R.; Gonzales, L. M.; Keane, C. M.

2011-12-01

Targeted recruitment and retention efforts for the geosciences have become increasingly important with the growing concerns about program visibility on campuses, and given that geoscience degree production remains low relative to the demand for new geoscience graduates. Furthermore, understanding the career trajectories of geoscience degree recipients is essential for proper occupational placement. A theoretical framework was developed by Houlton (2010) to focus recruitment and retention efforts. This "pathway model" explicitly maps undergraduate students' geoscience career trajectories, which can be used to refine existing methods for recruiting students into particular occupations. Houlton's (2010) framework identified three main student population groups: Natives, Immigrants or Refugees. Each student followed a unique pathway, which consisted of six pathway steps. Each pathway step was comprised of critical incidents that influenced students' overall career trajectories. An aggregate analysis of students' pathways (Academic Provenance Analysis) showed that different populations' pathways exhibited a deviation in career direction: Natives indicated intentions to pursue industry or government sectors, while Immigrants intended to pursue academic or research-based careers. We expanded on Houlton's (2010) research by conducting a follow-up study to determine if the original participants followed the career trajectories they initially indicated in the 2010 study. A voluntary, 5-question, short-answer survey was administered via email. We investigated students' current pathway steps, pathway deviations, students' goals for the near future and their ultimate career ambitions. This information may help refine Houlton's (2010) "pathway model" and may aid geoscience employers in recruiting the new generation of professionals for their respective sectors.

An intelligent listening framework for capturing encounter notes from a doctor-patient dialog

PubMed Central

Klann, Jeffrey G; Szolovits, Peter

2009-01-01

Background Capturing accurate and machine-interpretable primary data from clinical encounters is a challenging task, yet critical to the integrity of the practice of medicine. We explore the intriguing possibility that technology can help accurately capture structured data from the clinical encounter using a combination of automated speech recognition (ASR) systems and tools for extraction of clinical meaning from narrative medical text. Our goal is to produce a displayed evolving encounter note, visible and editable (using speech) during the encounter. Results This is very ambitious, and so far we have taken only the most preliminary steps. We report a simple proof-of-concept system and the design of the more comprehensive one we are building, discussing both the engineering design and challenges encountered. Without a formal evaluation, we were encouraged by our initial results. The proof-of-concept, despite a few false positives, correctly recognized the proper category of single-and multi-word phrases in uncorrected ASR output. The more comprehensive system captures and transcribes speech and stores alternative phrase interpretations in an XML-based format used by a text-engineering framework. It does not yet use the framework to perform the language processing present in the proof-of-concept. Conclusion The work here encouraged us that the goal is reachable, so we conclude with proposed next steps. Some challenging steps include acquiring a corpus of doctor-patient conversations, exploring a workable microphone setup, performing user interface research, and developing a multi-speaker version of our tools. PMID:19891797

Growth of Transgressive Sills in Mechanically Layered Media: Faroe Islands, NE Atlantic Margin

NASA Astrophysics Data System (ADS)

Walker, R. J.

2014-12-01

Igneous sills represent an important contribution to upper crustal magma transport, acting as magma conduits and stores (i.e. as sill networks, or as nascent magma chambers). Complex sill-network intrusion in basin settings can have significant impact on subsurface fluid flow (e.g., water aquifer and hydrocarbon systems), geothermal systems, the maturation of hydrocarbons, and methane release. Models for these effects are critically dependent on the models for sill emplacement. This study focuses on staircase-geometry sills in the Faroe Islands, on the European Atlantic Margin, which are hosted in mechanically layered lavas (1-20 m thick) and basaltic volcaniclastic units (1-30 m thick). The sills range from 20-50 m thick, with each covering ~17 km2, and transgressing a vertical range of ~480 m. Steps in the sills are elliptical in cross section, and discontinuous laterally, forming smooth transgressive ramps, hence are interpreted as representing initial stages of sill propagation as magma fingers, which inflate through time to create a through-going sheet. Although steps correspond to the position of some host rock layer interfaces and volcaniclastic horizons, most interfaces are bypassed. The overall geometry of the sills is consistent with ENE-WSW compression, and NNW-SSE extension, and stress anisotropy-induced transgression. Local morphology indicates that mechanical layering suppressed tensile stress ahead of the crack tip, leading to a switch in minimum and intermediate stress axes, facilitating lateral sill propagation as fingers, and resulting in a stepped transgressive geometry.

Destination Math. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2009

2009-01-01

"Destination Math" is a series of computer-based curricula designed to be used for at least 90 minutes a week. Featuring sequenced, prescriptive, step-by-step instruction, "Destination Math" is designed for the development of fluency in critical skills, math reasoning, conceptual understanding, and problem-solving skills.…

Critical behavior of a two-step contagion model with multiple seeds

NASA Astrophysics Data System (ADS)

Choi, Wonjun; Lee, Deokjae; Kahng, B.

2017-06-01

A two-step contagion model with a single seed serves as a cornerstone for understanding the critical behaviors and underlying mechanism of discontinuous percolation transitions induced by cascade dynamics. When the contagion spreads from a single seed, a cluster of infected and recovered nodes grows without any cluster merging process. However, when the contagion starts from multiple seeds of O (N ) where N is the system size, a node weakened by a seed can be infected more easily when it is in contact with another node infected by a different pathogen seed. This contagion process can be viewed as a cluster merging process in a percolation model. Here we show analytically and numerically that when the density of infectious seeds is relatively small but O (1 ) , the epidemic transition is hybrid, exhibiting both continuous and discontinuous behavior, whereas when it is sufficiently large and reaches a critical point, the transition becomes continuous. We determine the full set of critical exponents describing the hybrid and the continuous transitions. Their critical behaviors differ from those in the single-seed case.

Clinopyroxene Diffusion Chronometry of the Scaup Lake Rhyolite, Yellowstone Caldera, WY

NASA Astrophysics Data System (ADS)

Brugman, K. K.; Till, C. B.; Bose, M.

2016-12-01

Eruption of the Scaup Lake flow (SCL) ended 220,000 years of dormancy and began the youngest sequence of eruptions at Yellowstone caldera [Christiansen et al., USGS, 2007]. Quantification of the time intervals between magmatic events and eruption recorded in SCL is critical to interpreting signs of unrest at modern-day Yellowstone. SCL rhyolite includes zoned phenocrysts and accessory phases that indicate multiple rejuvenation events occurred shortly before eruption; previous studies focused on feldspar and zircon crystal records [e.g. Bindeman et al., J.Pet, 2008; Till et al., Geology, 2015]. Here we exploit zoned clinopyroxene (cpx)—one of the earliest-crystalized minerals in SCL as indicated by petrographic relationships—as a diffusion dating tool and utilize elements with different diffusivities to more precisely resolve rejuvenation-eruption timescales. Using NanoSIMS concentration profiles with 300-900 nanometer spacing, we employ the slower-diffusing REE Ce as a proxy for the initial profile shape of faster-diffusing Fe to calculate diffusive timescales. The outermost resolvable zone boundary in SCL cpx yields a rejuvenation-eruption timescale of 166 ± 80 yrs (1 SD). In comparison, modeling relaxation of Fe from a step function initial condition at the same temperature (920°C) yields a less precise timescale of 488 +9000 -300 yrs. Examination of our results, in concert with observed petrographic relationships, indicates SCL cpx may record an older, separate rejuvenation event than those recorded in feldspar rims at < 10 months and 10-40 years prior to eruption [Till et al., Geology, 2015]. The difference in the youngest recorded event between feldspar and cpx may be due to different crystallization intervals for these phases and/or slower crystal growth rates for cpx relative to feldspar. Our diffusion modeling results reinforce that intracrystalline zoning timescales modeled using a step function initial condition should be considered maxima, especially in viscous rhyolitic magmas, and that different phases may not record the same series of pre-eruptive events due to differences in crystallization behavior.

An integrated assessment instrument: Developing and validating instrument for facilitating critical thinking abilities and science process skills on electrolyte and nonelectrolyte solution matter

NASA Astrophysics Data System (ADS)

Astuti, Sri Rejeki Dwi; Suyanta, LFX, Endang Widjajanti; Rohaeti, Eli

2017-05-01

The demanding of assessment in learning process was impact by policy changes. Nowadays, assessment is not only emphasizing knowledge, but also skills and attitudes. However, in reality there are many obstacles in measuring them. This paper aimed to describe how to develop integrated assessment instrument and to verify instruments' validity such as content validity and construct validity. This instrument development used test development model by McIntire. Development process data was acquired based on development test step. Initial product was observed by three peer reviewer and six expert judgments (two subject matter experts, two evaluation experts and two chemistry teachers) to acquire content validity. This research involved 376 first grade students of two Senior High Schools in Bantul Regency to acquire construct validity. Content validity was analyzed used Aiken's formula. The verifying of construct validity was analyzed by exploratory factor analysis using SPSS ver 16.0. The result show that all constructs in integrated assessment instrument are asserted valid according to content validity and construct validity. Therefore, the integrated assessment instrument is suitable for measuring critical thinking abilities and science process skills of senior high school students on electrolyte solution matter.

Methylation controls the low temperature induction of flowering in Arabidopsis.

PubMed

Dennis, E S; Bilodeau, P; Burn, J; Finnegan, E J; Genger, R; Helliwell, C; Kang, B J; Sheldon, C C; Peacock, W J

1998-01-01

Control of the transition to flowering is critical for reproductive success of a plant. Studies in Arabidopsis have led us to suggest how this species has harnessed the environmental cue of a period of low temperature to ensure flowering occurs at an appropriate time. We propose that Arabidopsis has both vernalization-independent and vernalization-dependent pathways for the initiation of inflorescence development in the shoot apex. The vernalization-independent pathway may be concerned with the supply of carbohydrate to the shoot apex. In late flowering ecotypes which respond to vernalization the vernalization-independent pathway is blocked by the action of two dominant repressors of flowering, FRI and FLC, which interact to produce very late flowering plants which respond strongly to vernalization. We have isolated a gene which may correspond to FLC. We suggest the vernalization-dependent pathway, which may be concerned with apical GA biosynthesis, is blocked by methylation of a gene critical for flowering. This gene may correspond to that encoding kaurenoic acid hydroxylase (KAH), an enzyme catalysing a step in the GA biosynthetic pathway. Under this scheme vernalization causes unblocking of this pathway by demethylation possibly of the KAH gene and consequent biosynthesis of active GAs in the apex.

Multiple effects of S13 in modulating the strength of intersubunit interactions in the ribosome during translation.

PubMed

Cukras, Anthony R; Green, Rachel

2005-05-27

The ribosomal protein S13 is found in the head region of the small subunit, where it interacts with the central protuberance of the large ribosomal subunit and with the P site-bound tRNA through its extended C terminus. The bridging interactions between the large and small subunits are dynamic, and are thought to be critical in orchestrating the molecular motions of the translation cycle. S13 provides a direct link between the tRNA-binding site and the movements in the head of the small subunit seen during translocation, thereby providing a possible pathway of signal transduction. We have created and characterized an rpsM(S13)-deficient strain of Escherichia coli and have found significant defects in subunit association, initiation and translocation through in vitro assays of S13-deficient ribosomes. Targeted mutagenesis of specific bridge and tRNA contact elements in S13 provides evidence that these two interaction domains play critical roles in maintaining the fidelity of translation. This ribosomal protein thus appears to play a non-essential, yet important role by modulating subunit interactions in multiple steps of the translation cycle.

Numerical study of heating and evaporation processes of quartz particles in RF inductively coupled plasma

NASA Astrophysics Data System (ADS)

Grishin, Yu M.; Miao, Long

2017-05-01

Numerical simulations of heat and evaporation processes of quartz particles in Ar radio frequency inductively coupled plasma (ICP) are investigated. The quartz particles are supplied by the carrier gas into the ICP within gas-cooling. It is shown that with the increase of amplitude of discharge current above critical value there is a toroidal vortex in the ICP torch at the first coil. The conditions for the formation of vortex and the parameters of the vortex tube have been evaluated and determined. The influence of vortex, discharge current, coil numbers and feed rate of carrier gas on the evaporation efficiency of quartz particles have been demonstrated. It was found that the optimal discharge current is close to the critical value when the quartz particles with initial sizes up to 130 μm can be fully vaporized in the ICP torch with thermal power of 10kW. The heat and evaporation processes of quartz particles in the ICP torch have significant importance for the study of one-step plasma chemical reaction method directly producing silicon from silicide (SiO2) in the argon-hydrogen plasma.

Economics of fluid therapy in critically ill patients.

PubMed

Lyu, Peter F; Murphy, David J

2014-08-01

Fluid therapy practices are an ongoing debate in critical care as evidence continues to emerge on the clinical effectiveness of different fluids and regimens. Although fluid therapy is a frequent and often costly treatment in the ICU, cost considerations have been largely absent from these studies. To facilitate a more structured approach to understanding fluid therapy costs and their role in clinical practice, we summarize currently available options and describe a framework for identifying and organizing relevant costs. Fluid therapy is a complex area of care that has been rarely studied from a cost-effectiveness perspective. We identify seven cost areas that capture fluid therapy-related costs during preutilization, point-of-utilization, and postutilization periods. These costs are driven by decisions on the type of fluid and administration strategy. Although estimates for some cost areas could be informed by medical literature, other cost areas remain unclear and require further investigation. Given the growing emphasis on the value of care, providers must recognize the important cost consequences of clinical decisions in fluid therapy. Future research into fluid therapy costs is needed and can be guided by this framework. Developing a complete cost picture is an initial and necessary step for improving values for patients, hospitals, and healthcare systems.

Mammalian cell culture monitoring using in situ spectroscopy: Is your method really optimised?

PubMed

André, Silvère; Lagresle, Sylvain; Hannas, Zahia; Calvosa, Éric; Duponchel, Ludovic

2017-03-01

In recent years, as a result of the process analytical technology initiative of the US Food and Drug Administration, many different works have been carried out on direct and in situ monitoring of critical parameters for mammalian cell cultures by Raman spectroscopy and multivariate regression techniques. However, despite interesting results, it cannot be said that the proposed monitoring strategies, which will reduce errors of the regression models and thus confidence limits of the predictions, are really optimized. Hence, the aim of this article is to optimize some critical steps of spectroscopic acquisition and data treatment in order to reach a higher level of accuracy and robustness of bioprocess monitoring. In this way, we propose first an original strategy to assess the most suited Raman acquisition time for the processes involved. In a second part, we demonstrate the importance of the interbatch variability on the accuracy of the predictive models with a particular focus on the optical probes adjustment. Finally, we propose a methodology for the optimization of the spectral variables selection in order to decrease prediction errors of multivariate regressions. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:308-316, 2017. © 2017 American Institute of Chemical Engineers.

Implementation of hazard analysis and critical control point (HACCP) in dried anchovy production process

NASA Astrophysics Data System (ADS)

Citraresmi, A. D. P.; Wahyuni, E. E.

2018-03-01

The aim of this study was to inspect the implementation of Hazard Analysis and Critical Control Point (HACCP) for identification and prevention of potential hazards in the production process of dried anchovy at PT. Kelola Mina Laut (KML), Lobuk unit, Sumenep. Cold storage process is needed in each anchovy processing step in order to maintain its physical and chemical condition. In addition, the implementation of quality assurance system should be undertaken to maintain product quality. The research was conducted using a survey method, by following the whole process of making anchovy from the receiving raw materials to the packaging of final product. The method of data analysis used was descriptive analysis method. Implementation of HACCP at PT. KML, Lobuk unit, Sumenep was conducted by applying Pre Requisite Programs (PRP) and preparation stage consisting of 5 initial stages and 7 principles of HACCP. The results showed that CCP was found in boiling process flow with significant hazard of Listeria monocytogenesis bacteria and final sorting process with significant hazard of foreign material contamination in the product. Actions taken were controlling boiling temperature of 100 – 105°C for 3 - 5 minutes and training for sorting process employees.

The Relationship Between Constraint and Ductile Fracture Initiation as Defined by Micromechanical Analyses

NASA Technical Reports Server (NTRS)

Panontin, Tina L.; Sheppard, Sheri D.

1994-01-01

The use of small laboratory specimens to predict the integrity of large, complex structures relies on the validity of single parameter fracture mechanics. Unfortunately, the constraint loss associated with large scale yielding, whether in a laboratory specimen because of its small size or in a structure because it contains shallow flaws loaded in tension, can cause the breakdown of classical fracture mechanics and the loss of transferability of critical, global fracture parameters. Although the issue of constraint loss can be eliminated by testing actual structural configurations, such an approach can be prohibitively costly. Hence, a methodology that can correct global fracture parameters for constraint effects is desirable. This research uses micromechanical analyses to define the relationship between global, ductile fracture initiation parameters and constraint in two specimen geometries (SECT and SECB with varying a/w ratios) and one structural geometry (circumferentially cracked pipe). Two local fracture criteria corresponding to ductile fracture micromechanisms are evaluated: a constraint-modified, critical strain criterion for void coalescence proposed by Hancock and Cowling and a critical void ratio criterion for void growth based on the Rice and Tracey model. Crack initiation is assumed to occur when the critical value in each case is reached over some critical length. The primary material of interest is A516-70, a high-hardening pressure vessel steel sensitive to constraint; however, a low-hardening structural steel that is less sensitive to constraint is also being studied. Critical values of local fracture parameters are obtained by numerical analysis and experimental testing of circumferentially notched tensile specimens of varying constraint (e.g., notch radius). These parameters are then used in conjunction with large strain, large deformation, two- and three-dimensional finite element analyses of the geometries listed above to predict crack initiation loads and to calculate the associated (critical) global fracture parameters. The loads are verified experimentally, and microscopy is used to measure pre-crack length, crack tip opening displacement (CTOD), and the amount of stable crack growth. Results for A516-70 steel indicate that the constraint-modified, critical strain criterion with a critical length approximately equal to the grain size (0.0025 inch) provides accurate predictions of crack initiation. The critical void growth criterion is shown to considerably underpredict crack initiation loads with the same critical length. The relationship between the critical value of the J-integral for ductile crack initiation and crack depth for SECT and SECB specimens has been determined using the constraint-modified, critical strain criterion, demonstrating that this micromechanical model can be used to correct in-plane constraint effects due to crack depth and bending vs. tension loading. Finally, the relationship developed for the SECT specimens is used to predict the behavior of circumferentially cracked pipe specimens.

Initiative Games in Physical Education: A Practical Approach for Teaching Critical Thinking Skills--Part 1

ERIC Educational Resources Information Center

Maina, Michael P.; Maina, Julie Schlegel; Hunt, Kevin

2016-01-01

As teachers prepare children for the future, the need for developing critical thinking skills in students becomes clearly evident. One way to promote this process is through initiative games. Initiative games are clearly defined problems that a group must find a solution to through cooperation, physical effort and cognitive functioning. The…

The Enactment of the Policy Initiative for Critical Thinking in Singapore Schools

ERIC Educational Resources Information Center

Tan, Charlene

2017-01-01

This article examines the enactment of the policy initiative to promote critical thinking in Singapore schools from the perspectives of educators in Singapore. It is argued that teachers in Singapore are not passive recipients or mere implementers of top-down policy decisions. Rather, they enact the policy initiative by making sense of,…

Development of a Premium Quality Plasma-derived IVIg (IQYMUNE®) Utilizing the Principles of Quality by Design-A Worked-through Case Study.

PubMed

Paolantonacci, Philippe; Appourchaux, Philippe; Claudel, Béatrice; Ollivier, Monique; Dennett, Richard; Siret, Laurent

2018-01-01

Polyvalent human normal immunoglobulins for intravenous use (IVIg), indicated for rare and often severe diseases, are complex plasma-derived protein preparations. A quality by design approach has been used to develop the Laboratoire Français du Fractionnement et des Biotechnologies new-generation IVIg, targeting a high level of purity to generate an enhanced safety profile while maintaining a high level of efficacy. A modular approach of quality by design was implemented consisting of five consecutive steps to cover all the stages from the product design to the final product control strategy.A well-defined target product profile was translated into 27 product quality attributes that formed the basis of the process design. In parallel, a product risk analysis was conducted and identified 19 critical quality attributes among the product quality attributes. Process risk analysis was carried out to establish the links between process parameters and critical quality attributes. Twelve critical steps were identified, and for each of these steps a risk mitigation plan was established.Among the different process risk mitigation exercises, five process robustness studies were conducted at qualified small scale with a design of experiment approach. For each process step, critical process parameters were identified and, for each critical process parameter, proven acceptable ranges were established. The quality risk management and risk mitigation outputs, including verification of proven acceptable ranges, were used to design the process verification exercise at industrial scale.Finally, the control strategy was established using a mix, or hybrid, of the traditional approach plus elements of the quality by design enhanced approach, as illustrated, to more robustly assign material and process controls and in order to securely meet product specifications.The advantages of this quality by design approach were improved process knowledge for industrial design and process validation and a clear justification of the process and product specifications as a basis for control strategy and future comparability exercises. © PDA, Inc. 2018.

Reducing Unnecessary Portable Pelvic Radiographs in Trauma Patients: A Resident-Driven Quality Improvement Initiative.

PubMed

Langer, Jessica M; Tsai, Emily B; Luhar, Aarti; McWilliams, Justin; Motamedi, Kambiz

2015-09-01

Quality improvement is increasingly important in the changing health care climate. We aim to establish a methodology and identify critical factors leading to successful implementation of a resident-led radiology quality improvement intervention at the institutional level. Under guidance of faculty mentors, the first-year radiology residents developed a quality improvement initiative to decrease unnecessary STAT pelvic radiographs (PXRs) in hemodynamically stable trauma patients who would additionally receive STAT pelvic CT scans. Development and implementation of this initiative required multiple steps, including: establishing resident and faculty leadership, gathering evidence from published literature, cultivating multidisciplinary support, and developing and implementing an institution-wide ordering algorithm. A visual aid and brief questionnaire were distributed to clinicians for use during treatment of trauma cases to ensure sustainability of the initiative. At multiple time points, pre- and post-intervention, residents performed a retrospective chart review to evaluate changes in imaging-ordering trends for trauma patients. Chart review showed a decline in the number of PXRs for hemodynamically stable trauma patients, as recommended in the ordering algorithm: 78% of trauma patients received both a PXR and a pelvic CT scan in the first 24 hours of the initiative, compared with 26% at 1 month; 24% at 6 months; and 18% at 10 to 12 months postintervention. The resident-led radiology quality improvement initiative created a shift in ordering culture at an institutional level. Development and implementation of this algorithm exemplified the impact of a multidisciplinary collaborative effort involving multiple departments and multiple levels of the medical hierarchy. Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Triggered lightning strikes to aircraft and natural intracloud discharges

NASA Technical Reports Server (NTRS)

Mazur, Vladislav

1989-01-01

The physical model of Mazur (1989) for triggering lightning strikes by aircraft was used to interpret the initiation of intracloud flashes observed by the French UHF-VHF interferometric system. It is shown that both the intracloud discharges and airplane-triggered lightning strikes were initiated by simultaneous bidirectional development of the negative stepped leader and the positive leader-continous current process. However, the negative stepped leader phase in triggered flashes is of shorter duration (tens of milliseconds), than that in intracloud flashes (usually hundreds of milliseconds). This is considered to be due to the fact that, on the aircraft there is a single initiation process, versus the numerous initiation processes that occur inside the cloud.

A case study: the initiative to improve RN scheduling at Hamilton Health Sciences.

PubMed

Wallace, Laurel-Anne; Pierson, Sharon

2008-01-01

In 2003, Hamilton Health Sciences embarked on an initiative to improve and standardize nursing schedules and scheduling practices. The scheduling project was one of several initiatives undertaken by a corporate-wide Nursing Resource Group established to enhance the work environment and patient care and to ensure appropriate utilization of nursing resources across the organization's five hospitals. This article focuses on major activities undertaken in the scheduling initiative. The step-by-step approach described, plus examples of the scheduling resources developed and samples of extended-tour schedules, will all provide insight, potential strategies and practical help for nursing administrators, human resources (HR) personnel and others interested in improving nurse scheduling.

Effects of age and lean direction on the threshold of single-step balance recovery in younger, middle-aged and older adults.

PubMed

Carbonneau, Evelyne; Smeesters, Cécile

2014-01-01

Several studies have quantified and compared balance recovery between healthy younger and older adults, using a variety of large postural perturbations and loss of balance directions. However, to the best of our knowledge, no studies at the threshold of balance recovery, where avoiding a fall is not always possible, have included middle-aged adults. We thus determined the maximum lean angle from which 20 younger, 16 middle-aged and 16 older healthy adults could be suddenly released and still recover balance using a single step for forward, sideways and backward leans. Results showed that the maximum lean angles of younger adults were 23% greater than middle-aged adults and 48% greater than older adults. The maximum lean angles for forward leans were 23% greater than sideways leans and 22% greater than backward leans. These declines with age and lean direction were associated with declines in response initiation, execution and geometry. Finally exponential regressions showed that the critical ages at which the ability to recover balance and avoid a fall significantly decreases were 51.0, 60.6 and 69.9 yrs for forward, sideways and backward leans, respectively. Therefore, we have demonstrated that age affects the ability to recover balance nearly a decade earlier than the rate of falls. Future studies should thus not only include older adults over 65 yrs, but also middle-aged adults under 65 yrs, or recruit all ages from 18 to 85 yrs. Finally, the critical ages identified in this study may justify an earlier screening of aging adults to prevent future falls, especially the first fall. Copyright © 2013 Elsevier B.V. All rights reserved.

Improving HIV outcomes in resource-limited countries: the importance of quality indicators.

PubMed

Ahonkhai, Aima A; Bassett, Ingrid V; Ferris, Timothy G; Freedberg, Kenneth A

2012-11-24

Resource-limited countries increasingly depend on quality indicators to improve outcomes within HIV treatment programs, but indicators of program performance suitable for use at the local program level remain underdeveloped. Using the existing literature as a guide, we applied standard quality improvement (QI) concepts to the continuum of HIV care from HIV diagnosis, to enrollment and retention in care, and highlighted critical service delivery process steps to identify opportunities for performance indicator development. We then identified existing indicators to measure program performance, citing examples used by pivotal donor agencies, and assessed their feasibility for use in surveying local program performance. Clinical delivery steps without existing performance measures were identified as opportunities for measure development. Using National Quality Forum (NQF) criteria as a guide, we developed measurement concepts suitable for use at the local program level that address existing gaps in program performance assessment. This analysis of the HIV continuum of care identified seven critical process steps providing numerous opportunities for performance measurement. Analysis of care delivery process steps and the application of NQF criteria identified 24 new measure concepts that are potentially useful for improving operational performance in HIV care at the local level. An evidence-based set of program-level quality indicators is critical for the improvement of HIV care in resource-limited settings. These performance indicators should be utilized as treatment programs continue to grow.

Pregnant & Lactating Mothers' Attitudes and Practice of the Ten Steps to Successful Breastfeeding at King Fahd Hospital of University (KFHU)--Khobar, Saudi Arabia: Appraisal of Baby Friendly Hospital Initiatives

ERIC Educational Resources Information Center

Salem, Laila Younis Abu; Al Madani, Maha Mohammed

2015-01-01

Background: World Health organization (WHO) and the United Nations Children's Fund (UNICEF) have been recommended the application of the Ten Steps to Successful Breastfeeding of the Baby-Friendly Hospital Initiative (BFHI) in order to promote & support breastfeeding. The aim of this study was to assess pregnant and lactating mothers' attitudes…

Biomedical Information Extraction: Mining Disease Associated Genes from Literature

ERIC Educational Resources Information Center

Huang, Zhong

2014-01-01

Disease associated gene discovery is a critical step to realize the future of personalized medicine. However empirical and clinical validation of disease associated genes are time consuming and expensive. In silico discovery of disease associated genes from literature is therefore becoming the first essential step for biomarker discovery to…

The Practical Search

ERIC Educational Resources Information Center

Hamilton, John D.

2007-01-01

Although the five classic evidence-based medicine steps to make the literature useful in caring for patients sound simple, most clinicians who try this approach do not find it easy. Although the first step--creating an answerable question--is manageable for busy clinicians, tracking down "the best evidence" and critically appraising it for…

The Creative Music Strategy: A Seven-Step Instructional Model

ERIC Educational Resources Information Center

Robinson, Nathalie G.; Bell, Cindy L.; Pogonowski, Lenore

2011-01-01

The creative music strategy is a dynamic and flexible seven-step model for guiding general music students through the music concepts of improvisation and composition, followed by critical reflection. These are musical behaviors that cultivate the development of our students' deeper conceptual understandings and music independence by helping them…

Special Education Eligibility: A Step-by-Step Guide for Educators

ERIC Educational Resources Information Center

Pierangelo, Roger; Giuliani, George A.

2007-01-01

Understanding the criteria and process for determining a student's eligibility for special education services is critical for any educator in an inclusive school environment. Based on the current reauthorization of IDEA 2004, this timely resource offers teachers and administrators an overview of each eligible disability and clear, specific…

Chemical Genetics Reveals Bacterial and Host Cell Functions Critical for Type IV Effector Translocation by Legionella pneumophila

PubMed Central

Charpentier, Xavier; Gabay, Joëlle E.; Reyes, Moraima; Zhu, Jing W.; Weiss, Arthur; Shuman, Howard A.

2009-01-01

Delivery of effector proteins is a process widely used by bacterial pathogens to subvert host cell functions and cause disease. Effector delivery is achieved by elaborate injection devices and can often be triggered by environmental stimuli. However, effector export by the L. pneumophila Icm/Dot Type IVB secretion system cannot be detected until the bacterium encounters a target host cell. We used chemical genetics, a perturbation strategy that utilizes small molecule inhibitors, to determine the mechanisms critical for L. pneumophila Icm/Dot activity. From a collection of more than 2,500 annotated molecules we identified specific inhibitors of effector translocation. We found that L. pneumophila effector translocation in macrophages requires host cell factors known to be involved in phagocytosis such as phosphoinositide 3-kinases, actin and tubulin. Moreover, we found that L. pneumophila phagocytosis and effector translocation also specifically require the receptor protein tyrosine phosphate phosphatases CD45 and CD148. We further show that phagocytosis is required to trigger effector delivery unless intimate contact between the bacteria and the host is artificially generated. In addition, real-time analysis of effector translocation suggests that effector export is rate-limited by phagocytosis. We propose a model in which L. pneumophila utilizes phagocytosis to initiate an intimate contact event required for the translocation of pre-synthesized effector molecules. We discuss the need for host cell participation in the initial step of the infection and its implications in the L. pneumophila lifestyle. Chemical genetic screening provides a novel approach to probe the host cell functions and factors involved in host–pathogen interactions. PMID:19578436

Development of a critical appraisal tool to assess the quality of cross-sectional studies (AXIS)

PubMed Central

Downes, Martin J; Brennan, Marnie L; Williams, Hywel C; Dean, Rachel S

2016-01-01

Objectives The aim of this study was to develop a critical appraisal (CA) tool that addressed study design and reporting quality as well as the risk of bias in cross-sectional studies (CSSs). In addition, the aim was to produce a help document to guide the non-expert user through the tool. Design An initial scoping review of the published literature and key epidemiological texts was undertaken prior to the formation of a Delphi panel to establish key components for a CA tool for CSSs. A consensus of 80% was required from the Delphi panel for any component to be included in the final tool. Results An initial list of 39 components was identified through examination of existing resources. An international Delphi panel of 18 medical and veterinary experts was established. After 3 rounds of the Delphi process, the Appraisal tool for Cross-Sectional Studies (AXIS tool) was developed by consensus and consisted of 20 components. A detailed explanatory document was also developed with the tool, giving expanded explanation of each question and providing simple interpretations and examples of the epidemiological concepts being examined in each question to aid non-expert users. Conclusions CA of the literature is a vital step in evidence synthesis and therefore evidence-based decision-making in a number of different disciplines. The AXIS tool is therefore unique and was developed in a way that it can be used across disciplines to aid the inclusion of CSSs in systematic reviews, guidelines and clinical decision-making. PMID:27932337

Growth and Morphology of Supercritical Fluids Studied in Microgravity on Mir

NASA Technical Reports Server (NTRS)

Wilkinson, R. Allen

2000-01-01

The Growth and Morphology of Supercritical Fluids (GMSF) is an international experiment facilitated by the NASA Glenn Research Center at Lewis Field and under the guidance of U.S. principal investigator Professor John Hegseth of the University of New Orleans and three French coinvestigators Daniel Beysens, Yves Garrabos, and Carole Chabot. In early 1999, GMSF experiments were operated for 20 days on the Russian Space Station Mir. Mir astronauts performed experiments One through Seven, which spanned the three science themes of near-critical phase separation rates, interface dynamics in near-critical boiling, and measurement of the spectrum of density fluctuation length scales very close to the critical point. The fluids used were pure CO2 or SF6. Three of the five thermostats used could adjust the sample volume with the scheduled crew time. Such a volume adjustment enabled variable sample densities around the critical density as well as pressure steps (as distinct from the usual temperature steps) to be applied to the sample.

Pure F-actin networks are distorted and branched by steps in the critical-point drying method.

PubMed

Resch, Guenter P; Goldie, Kenneth N; Hoenger, Andreas; Small, J Victor

2002-03-01

Elucidation of the ultrastructural organization of actin networks is crucial for understanding the molecular mechanisms underlying actin-based motility. Results obtained from cytoskeletons and actin comets prepared by the critical-point procedure, followed by rotary shadowing, support recent models incorporating actin filament branching as a main feature of lamellipodia and pathogen propulsion. Since actin branches were not evident in earlier images obtained by negative staining, we explored how these differences arise. Accordingly, we have followed the structural fate of dense networks of pure actin filaments subjected to steps of the critical-point drying protocol. The filament networks have been visualized in parallel by both cryo-electron microscopy and negative staining. Our results demonstrate the selective creation of branches and other artificial structures in pure F-actin networks by the critical-point procedure and challenge the reliability of this method for preserving the detailed organization of actin assemblies that drive motility. (c) 2002 Elsevier Science (USA).

Think Like a Nurse: A Critical Thinking Initiative.

PubMed

Ward, Terry D; Morris, Tiffany

2016-01-01

Critical thinking is essential in the practice of the nurse generalist, today. Nursing faculty is frequently trying to identify teaching strategies in promoting critical thinking and engaging students in active learning. To close the gap between critical thinking and student success, a school in the south east United States implemented the use of the 'think like a nurse initiative" for incoming junior nursing students. Faculty collaborated to adopt the fundamental and essential nursing concepts for nursing students to support thinking like a nurse.

Determining Water Quality Trends in the Sacramento-San Joaquin Delta Watershed in the Face of Climate Change

NASA Astrophysics Data System (ADS)

Kynett, K.; Azimi-Gaylon, S.; Doidic, C.

2014-12-01

The Sacramento-San Joaquin Delta and Suisun Marsh (Delta) is the largest estuary on the West Coast of the Americas and is a resource of local, State, and national significance. The Delta is simultaneously the most critical component of California's water supply, a primary focus of the state's ecological conservation measures, and a vital resource deeply imperiled by degraded water quality. Delta waterbodies are identified as impaired by salinity, excess nutrients, low dissolved oxygen, pathogens, pesticides, heavy metals, and other contaminants. Climate change is expected to exacerbate the impacts of existing stressors in the Delta and magnify the challenges of managing this natural resource. A clear understanding of the current state of the watershed is needed to better inform scientists, decision makers, and the public about potential impacts from climate change. The Delta Watershed Initiative Network (Delta WIN) leverages the ecological benefits of healthy watersheds, and enhances, expands and creates opportunities for greater watershed health by coordinating with agencies, established programs, and local organizations. At this critical junction, Delta WIN is coordinating data integration and analysis to develop better understanding of the existing and emerging water quality concerns. As first steps, Delta WIN is integrating existing water quality data, analyzing trends, and monitoring to fill data gaps and to evaluate indicators of climate change impacts. Available data will be used for trend analysis; Delta WIN will continue to monitor where data is incomplete and new questions arise. Understanding how climate change conditions may affect water quality will be used to inform efforts to build resilience and maintain water quality levels which sustain aquatic life and human needs. Assessments of historical and new data will aid in recognition of potential climate change impacts and in initiating implementation of best management practices in collaboration with State and local agencies. Ultimately, Delta WIN can inform responsive science and adaptive management in other estuaries and critical natural resource areas facing times of change.

Compliance With WHO/UNICEF BFHI Standards in Croatia After Implementation of the BFHI.

PubMed

Zakarija-Grković, Irena; Boban, Marija; Janković, Sunčana; Ćuže, Anamarija; Burmaz, Tea

2018-02-01

The primary goal of the Baby-Friendly Hospital Initiative (BFHI) is to create conditions in maternity facilities that enable women to initiate and sustain the practice of breastfeeding exclusively. Research aim: This study aimed to determine hospital practices and breastfeeding rates before and after BFHI implementation and assess compliance with UNICEF/World Health Organization (WHO) standards for seven of the BFHI's Ten Steps to Successful Breastfeeding ( Ten Steps). Mothers of healthy, term infants ( N = 1,115) were recruited from the postnatal ward of the University Hospital of Split, Croatia, between February 2008 and July 2011 and followed for 12 months in a repeated-measures, prospective, longitudinal, three-group, nonequivalent, cohort study. Breastfeeding rates, hospital practices-including seven of the Ten Steps-and maternal sociodemographic data were collected. Parts of all seven Ten Steps that were assessed improved significantly post-BFHI. Step 3 ("antenatal education") showed the least improvement, whereas Step 7 ("rooming-in"; 2.6% pre-BFHI vs. 98.5% post-BFHI) and Step 9 ("no pacifiers/teats"; 21.8% pre-BFHI vs. 99.4% post-BFHI) showed the greatest improvement. Six months after Baby-Friendly designation, only Steps 7 and 9 were in full compliance with UNICEF/WHO standards. In-hospital, exclusive-breastfeeding rates rose markedly ( p < .001), but no change occurred in breastfeeding rates at 3, 6, or 12 months. Full implementation of the BFHI was associated with significant improvement in hospital practices and in-hospital, exclusive-breastfeeding rates, but it did not affect breastfeeding rates postdischarge, emphasizing the vital role of community support. Baby-Friendly Hospital Initiative standards declined rapidly post-hospital designation, indicating the need for regular monitoring and reassessment as well as ongoing, effective training for hospital staff.

Does footwear type impact the number of steps required to reach gait steady state?: an innovative look at the impact of foot orthoses on gait initiation.

PubMed

Najafi, Bijan; Miller, Daniel; Jarrett, Beth D; Wrobel, James S

2010-05-01

Many studies have attempted to better elucidate the effect of foot orthoses on gait dynamics. To our knowledge, most previous studies exclude the first few steps of gait and begin analysis at steady state walking. These unanalyzed steps of gait may contain important information about the dynamic and complex processes required to achieve equilibrium for a given gait velocity. The purpose of this study was to quantify gait initiation and determine how many steps were required to reach steady state walking under three footwear conditions: barefoot, habitual shoes, and habitual shoes with a prefabricated foot orthoses. Fifteen healthy subjects walked 50m at habitual speed in each condition. Wearing habitual shoes with the prefabricated orthoses enabled subjects to reach steady state walking in fewer steps (3.5 steps+/-2.0) compared to the barefoot condition (5.2 steps+/-3.0; p=0.02) as well as compared to the habitual shoes condition (4.7 steps+/-1.6; p=0.05). Interestingly, the subjects' dynamic medial-lateral balance was significantly improved (22%, p<0.05) by using foot orthoses compared to other footwear conditions. These findings suggest that foot orthoses may help individuals reach steady state more quickly and with a better dynamic balance in the medial-lateral direction, independent of foot type. The findings of this pilot study may open new avenues for objectively assessing the impact of prescription footwear on dynamic balance and spatio-temporal parameters of gait. Further work to better assess the impact of foot orthoses on gait initiation in patients suffering from gait and instability pathologies may be warranted. Copyright 2010 Elsevier B.V. All rights reserved.

An optimized fed-batch culture strategy integrated with a one-step fermentation improves L-lactic acid production by Rhizopus oryzae.

PubMed

Fu, Yongqian; Sun, Xiaolong; Zhu, Huayue; Jiang, Ru; Luo, Xi; Yin, Longfei

2018-05-21

In previous work, we proposed a novel modified one-step fermentation fed-batch strategy to efficiently generate L-lactic acid (L-LA) using Rhizopus oryzae. In this study, to further enhance efficiency of L-LA production through one-step fermentation in fed-batch cultures, we systematically investigated the initial peptone- and glucose-feeding approaches, including different initial peptone and glucose concentrations and maintained residual glucose levels. Based on the results of this study, culturing R. oryzae with initial peptone and glucose concentrations of 3.0 and 50.0 g/l, respectively, using a fed-batch strategy is an effective approach of producing L-LA through one-step fermentation. Changing the residual glucose had no obvious effect on the generation of L-LA. We determined the maximum LA production and productivity to be 162 g/l and 6.23 g/(l·h), respectively, during the acid production stage. Compared to our previous work, there was almost no change in L-LA production or yield; however, the productivity of L-LA increased by 14.3%.

Effect of 24-h continuous rotigotine treatment on stationary and non-stationary locomotion in de novo patients with Parkinson disease in an open-label uncontrolled study.

PubMed

Serrao, Mariano; Ranavolo, Alberto; Conte, Carmela; Davassi, Chiara; Mari, Silvia; Fasano, Alfonso; Chini, Giorgia; Coppola, Gianluca; Draicchio, Francesco; Pierelli, Francesco

2015-11-01

The aim of this study was to investigate the effect of a rotigotine transdermal patch on stationary and non-stationary locomotion in de novo Parkinson disease (PD) patients in an open-label uncontrolled study. A 3-D gait analysis system was used to investigate four different locomotor tasks: steady-state linear walking, gait initiation, gait termination and 180°-turning. A series of gait variables were measured for each locomotor task. PD patients who received rotigotine treatment (4-8 mg) displayed: (1) increased step length, gait speed, cadence and arm oscillations, and reduced double support duration and step asymmetry during steady-state linear gait; (2) increased initial step length during gait initiation; (3) increased final step length and gait speed, and decreased stability index during gait termination; (4) decreased duration of turning and head-pelvis delays during 180°-turning. The main finding that emerges from the present study is that the dopamine agonist rotigotine can improve various aspects of gait in de novo PD patients.

Combustion efficiency determined from wall pressure and temperature measurement in a Mach 2 combustor

NASA Technical Reports Server (NTRS)

Segal, Corin; Mcdaniel, James C.; Whitehurst, Robert B.; Krauss, Roland H.

1991-01-01

A study of transverse hydrogen injection behind a rearward facing step in a Mach 2 airflow was conducted to determine the combustion efficiency and the combustor/inlet interactions at the low temperature lean-mixture operational end of a scramjet combustor model. The fuel was injected at sonic conditions into the electrically heated airstream, which was maintained at 850 K or below. The static pressure delivered at the entrance of the combustor ranged between 0.25 to 0.5 atm. Injector configurations included single and staged injectors placed at 3 or 3-and-7 step-heights downstream of the step, respectively, with injector diameters of 1, 1.5, and 2 mm. Ignition was achieved by initially unstarting the test section. The constant area combustor and the low initial temperatures caused thermal choking and upstream interaction to occur at very low equivalence ratios. Typically, most of the fuel was burned in the recirculation region behind the step and around the jets. The effects of initial conditions (temperature and pressure), fuel-to-air dynamic pressure ratio, and boundaries (thermal vs adiabatic) are presented.

Stepping responses to treadmill perturbations vary with severity of motor deficits in human SCI.

PubMed

Chu, Virginia Way Tong; Hornby, T George; Schmit, Brian D

2018-04-18

In this study, we investigated the responses to tread perturbations during human stepping on a treadmill. Our approach was to test the effects of perturbations to a single leg using a split-belt treadmill in healthy participants and in participants with varying severity of spinal cord injury (SCI). We recruited 11 people with incomplete SCI and 5 noninjured participants. As participants walked on an instrumented treadmill, the belt on one side was stopped or accelerated briefly during mid to late stance. A majority of participants initiated an unnecessary swing when the treadmill was stopped in mid stance, although the likelihood of initiating a step was decreased in participants with more severe SCI. Accelerating or decelerating one belt of the treadmill during stance altered the characteristics of swing. We observed delayed swing initiation when the belt was decelerated (i.e. the hip was in a more flexed position at time of swing) and advanced swing initiation with acceleration (i.e. hip extended at swing initiation). Further, the timing and leg posture of heel strike appeared to remain constant, reflected by a sagittal plane hip angle at heel strike that remained the same regardless of the perturbation. In summary, our results supported the current understanding of the role of sensory feedback and central drive in the control of stepping in participants with incomplete SCI and noninjured participants. In particular, the observation of unnecessary swing during a stop perturbation highlights the interdependence of central and sensory drive in walking control.

Nucleation of uniform mono- and bilayer epitaxial graphene on SiC(0001)

NASA Astrophysics Data System (ADS)

Wu, Xiaosong; Zhang, Rui; Dong, Yunliang; Guo, Shuai; Kong, Wenjie; Liao, Zhimin; Yu, Dapeng

2012-02-01

Early stage of epitaxial graphene growth on SiC(0001) has been investigated. Using the confinement controlled sublimation (CCS) method, we has achieved well controlled growth and been able to see the formation of mono- and bilayer graphene islands. The growth features reveal the intriguing growth mechanism. In particular, a new ``stepdown'' growth mode has been identified. Graphene can propagate tens of micrometers across many SiC steps, while, most importantly, step bunching is avoided and the initial regular stepped SiC surface morphology is preserved. The stepdown growth demonstrates a route towards uniform epitaxial graphene in wafer size without sacrificing the initial substrate surface morphology.

Initial conditions for critical Higgs inflation

NASA Astrophysics Data System (ADS)

Salvio, Alberto

2018-05-01

It has been pointed out that a large non-minimal coupling ξ between the Higgs and the Ricci scalar can source higher derivative operators, which may change the predictions of Higgs inflation. A variant, called critical Higgs inflation, employs the near-criticality of the top mass to introduce an inflection point in the potential and lower drastically the value of ξ. We here study whether critical Higgs inflation can occur even if the pre-inflationary initial conditions do not satisfy the slow-roll behavior (retaining translation and rotation symmetries). A positive answer is found: inflation turns out to be an attractor and therefore no fine-tuning of the initial conditions is necessary. A very large initial Higgs time-derivative (as compared to the potential energy density) is compensated by a moderate increase in the initial field value. These conclusions are reached by solving the exact Higgs equation without using the slow-roll approximation. This also allows us to consistently treat the inflection point, where the standard slow-roll approximation breaks down. Here we make use of an approach that is independent of the UV completion of gravity, by taking initial conditions that always involve sub-planckian energies.

Novel synthesis and characterization of a collagen-based biopolymer initiated by hydroxyapatite nanoparticles.

PubMed

Bhuiyan, D; Jablonsky, M J; Kolesov, I; Middleton, J; Wick, T M; Tannenbaum, R

2015-03-01

In this study, we developed a novel synthesis method to create a complex collagen-based biopolymer that promises to possess the necessary material properties for a bone graft substitute. The synthesis was carried out in several steps. In the first step, a ring-opening polymerization reaction initiated by hydroxyapatite nanoparticles was used to polymerize d,l-lactide and glycolide monomers to form poly(lactide-co-glycolide) co-polymer. In the second step, the polymerization product was coupled with succinic anhydride, and subsequently was reacted with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide as the cross-linking agent, in order to activate the co-polymer for collagen attachment. In the third and final step, the activated co-polymer was attached to calf skin collagen type I, in hydrochloric acid/phosphate buffer solution and the precipitated co-polymer with attached collagen was isolated. The synthesis was monitored by proton nuclear magnetic resonance, infrared and Raman spectroscopies, and the products after each step were characterized by thermal and mechanical analysis. Calculations of the relative amounts of the various components, coupled with initial dynamic mechanical analysis testing of the resulting biopolymer, afforded a preliminary assessment of the structure of the complex biomaterial formed by this novel polymerization process. Copyright © 2015. Published by Elsevier Ltd.

The Critical Incident Interview and Ethnoracial Identity.

ERIC Educational Resources Information Center

Montalvo, Frank F.

1999-01-01

Describes the critical-incident interview, a cross-cultural training technique that helps social work students assess clients' ethnic- and racial-identity development. Uses examples from student interviews to present the steps involved in teaching the technique. Includes guidelines for selecting and interviewing informants, and gives three scales…

Three-Dimensional Structure of Boundary Layers in Transition to Turbulence

DTIC Science & Technology

1989-03-01

step-by-step Orr- Sommerfeld solution and integration. What is needed is an initial condition and initial wavenumber. These data can be obtained from a ...general than unsteady boundary-layer equations and Orr- Sommerfeld equation which are special cases. There- fore, the PSE will be a valuable tool for...spectra (discrete, continuous) result in a given problem is discussed in monographs and journal articles. Here, we try to find solutions to the

Integrating disease management and wound care critical pathways in home care.

PubMed

Barr, J E

1999-10-01

This article discusses the need for an integration of the concepts of disease management and critical pathways as a foundation of a healthcare delivery system. The steps in the process for development, implementation, and evaluation of a wound care critical pathway are reviewed and variance classifications are defined. Co-pathways and algorithms are presented as methodologies for dealing with variances. A template of a wound care critical pathway that has been developed for use in the home care setting is included.

A genetic explanation of Slaughter's concept of field cancerization: evidence and clinical implications.

PubMed

Braakhuis, Boudewijn J M; Tabor, Maarten P; Kummer, J Alain; Leemans, C René; Brakenhoff, Ruud H

2003-04-15

The concept of "field cancerization" was first introduced by Slaughter et al. [D. P, Slaughter et al., Cancer (Phila.), 6: 963-968, 1953] in 1953 when studying the presence of histologically abnormal tissue surrounding oral squamous cell carcinoma. It was proposed to explain the development of multiple primary tumors and locally recurrent cancer. Organ systems in which field cancerization has been described since then are: head and neck (oral cavity, oropharynx, and larynx), lung, vulva, esophagus, cervix, breast, skin, colon, and bladder. Recent molecular findings support the carcinogenesis model in which the development of a field with genetically altered cells plays a central role. In the initial phase, a stem cell acquires genetic alterations and forms a "patch," a clonal unit of altered daughter cells. These patches can be recognized on the basis of mutations in TP53, and have been reported for head and neck, lung, skin, and breast cancer. The conversion of a patch into an expanding field is the next logical and critical step in epithelial carcinogenesis. Additional genetic alterations are required for this step, and by virtue of its growth advantage, a proliferating field gradually displaces the normal mucosa. In the mucosa of the head and neck, as well as the esophagus, such fields have been detected with dimensions of >7 cm in diameter, whereas they are usually not detected by routine diagnostic techniques. Ultimately, clonal divergence leads to the development of one or more tumors within a contiguous field of preneoplastic cells. An important clinical implication is that fields often remain after surgery of the primary tumor and may lead to new cancers, designated presently by clinicians as "a second primary tumor" or "local recurrence," depending on the exact site and time interval. In conclusion, the development of an expanding preneoplastic field appears to be a critical step in epithelial carcinogenesis with important clinical consequences. Diagnosis and treatment of epithelial cancers should not only be focused on the tumor but also on the field from which it developed.

Paraná flood basalt volcanism primarily limited to 1 Myr beginning at 135 Ma: New 40Ar/39Ar ages for rocks from Rio Grande do Sul, and critical evaluation of published radiometric data

NASA Astrophysics Data System (ADS)

Baksi, Ajoy K.

2018-04-01

40Ar/39Ar step heating analyses were carried out on seven rocks (five basalts, an andesite and a rhyolite) from the southern Paraná Province ( 28°S-30°S); they yield plateau/isochron ages of 135-134 Ma, in good agreement with published step heating data on rocks from the same area. Critical review of laser spot isochron ages for rocks from the Province, ranging from 140 to 130 Ma, are shown to be unreliable estimates of crystallization ages, as the rocks were substantially altered; step heating results on three of these rocks thought to yield good plateau ages, are shown to be incorrect, as a result of a technicality in dating procedures followed. U-Pb ages on zircon and baddeleyite separated from a variety of rock types ( 30°S-23°S) fall in the range 135 to 134 Ma. All reliable 40Ar/39Ar and U-Pb ages indicate volcanism was sharply focused, initiated at 135 Ma, and 1 Myr in duration; no variation of age with either latitude or longitude is noted, Scrutiny of published 40Ar/39Ar ages on the Florianopolis dykes shows they cannot be used as reliable crystallization ages. U-Pb work shows that this dyke swarm was formed coevally with the main part of the Parana province. Most of the published 40Ar/39Ar ages on the Ponta Grossa dyke swarm are unreliable; a few ages appear reliable and suggest the magmatic event in this area, may have postdated the main Paraná pulse by 1-2 Myr. A single 40Ar/39Ar age from a high-Nb basalt in the southernmost part ( 34°S) of the Paraná at 135 Ma, highlights the need for further radiometric work on other areas of this flood basalt province. The Paraná Province postdates the time of the Jurassic-Cretaceous bound­ary by 10 Myr.

Multilevel Evaluation Alignment: An Explication of a Four-Step Model

ERIC Educational Resources Information Center

Yang, Huilan; Shen, Jianping; Cao, Honggao; Warfield, Charles

2004-01-01

Using the evaluation work on the W.K. Kellogg Foundation's Unleashing Resources Initiative as an example, in this article we explicate a general four-step model appropriate for multilevel evaluation alignment. We review the relevant literature, argue for the need for evaluation alignment in a multilevel context, explain the four-step model,…

Output-Sensitive Construction of Reeb Graphs.

PubMed

Doraiswamy, H; Natarajan, V

2012-01-01

The Reeb graph of a scalar function represents the evolution of the topology of its level sets. This paper describes a near-optimal output-sensitive algorithm for computing the Reeb graph of scalar functions defined over manifolds or non-manifolds in any dimension. Key to the simplicity and efficiency of the algorithm is an alternate definition of the Reeb graph that considers equivalence classes of level sets instead of individual level sets. The algorithm works in two steps. The first step locates all critical points of the function in the domain. Critical points correspond to nodes in the Reeb graph. Arcs connecting the nodes are computed in the second step by a simple search procedure that works on a small subset of the domain that corresponds to a pair of critical points. The paper also describes a scheme for controlled simplification of the Reeb graph and two different graph layout schemes that help in the effective presentation of Reeb graphs for visual analysis of scalar fields. Finally, the Reeb graph is employed in four different applications-surface segmentation, spatially-aware transfer function design, visualization of interval volumes, and interactive exploration of time-varying data.

Using the critical incident technique in community-based participatory research: a case study.

PubMed

Belkora, Jeffrey; Stupar, Lauren; O'Donnell, Sara

2011-01-01

Successful community-based participatory research involves the community partner in every step of the research process. The primary study for this paper took place in rural, Northern California. Collaborative partners included an academic researcher and two community based resource centers that provide supportive services to people diagnosed with cancer. This paper describes our use of the Critical Incident Technique (CIT) to conduct Community-based Participatory Research. We ask: Did the CIT facilitate or impede the active engagement of the community in all steps of the study process? We identified factors about the Critical Incident Technique that were either barriers or facilitators to involving the community partner in every step of the research process. Facilitators included the CIT's ability to accommodate involvement from a large spectrum of the community, its flexible design, and its personal approach. Barriers to community engagement included training required to conduct interviews, depth of interview probes, and time required. Overall, our academic-community partners felt that our use of the CIT facilitated community involvement in our Community-Based Participatory Research Project, where we used it to formally document the forces promoting and inhibiting successful achievement of community aims.

Cross-sectional observational assessment of quality of newborn care immediately after birth in health facilities across six sub-Saharan African countries

PubMed Central

de Graft-Johnson, Joseph; Vesel, Linda; Rosen, Heather E; Rawlins, Barbara; Abwao, Stella; Mazia, Goldy; Bozsa, Robert; Mwebesa, Winifrede; Khadka, Neena; Kamunya, Rosemary; Getachew, Ashebir; Tibaijuka, Gaudiosa; Rakotovao, Jean Pierre; Tekleberhan, Alemnesh

2017-01-01

Objective To present information on the quality of newborn care services and health facility readiness to provide newborn care in 6 African countries, and to advocate for the improvement of providers' essential newborn care knowledge and skills. Design Cross-sectional observational health facility assessment. Setting Ethiopia, Kenya, Madagascar, Mozambique, Rwanda and Tanzania. Participants Health workers in 643 facilities. 1016 health workers were interviewed, and 2377 babies were observed in the facilities surveyed. Main outcome measures Indicators of quality of newborn care included (1) provision of immediate essential newborn care: thermal care, hygienic cord care, and early and exclusive initiation of breast feeding; (2) actual and simulated resuscitation of asphyxiated newborn infants; and (3) knowledge of health workers on essential newborn care, including resuscitation. Results Sterile or clean cord cutting instruments, suction devices, and tables or firm surfaces for resuscitation were commonly available. 80% of newborns were immediately dried after birth and received clean cord care in most of the studied facilities. In all countries assessed, major deficiencies exist for essential newborn care supplies and equipment, as well as for health worker knowledge and performance of key routine newborn care practices, particularly for immediate skin-to-skin contact and breastfeeding initiation. Of newborns who did not cry at birth, 89% either recovered on their own or through active steps taken by the provider through resuscitation with initial stimulation and/or ventilation. 11% of newborns died. Assessment of simulated resuscitation using a NeoNatalie anatomic model showed that less than a third of providers were able to demonstrate ventilation skills correctly. Conclusions The findings shared in this paper call attention to the critical need to improve health facility readiness to provide quality newborn care services and to ensure that service providers have the necessary equipment, supplies, knowledge and skills that are critical to save newborn lives. PMID:28348194

Making Knowledge Delivery Failsafe: Adding Step Zero in Hypothesis Testing

ERIC Educational Resources Information Center

Pan, Xia; Zhou, Qiang

2010-01-01

Knowledge of statistical analysis is increasingly important for professionals in modern business. For example, hypothesis testing is one of the critical topics for quality managers and team workers in Six Sigma training programs. Delivering the knowledge of hypothesis testing effectively can be an important step for the incapable learners or…

The Budget Process in Parks and Recreation. A Case Study Manual.

ERIC Educational Resources Information Center

Kelsey, Craig; Gray, Howard

This case study manual, designed for undergraduate or graduate students studying the area of parks and recreation fiscal management, considers the practical, critical skills of budgeting techniques. The manual deals with the most common budgeting styles in a step-by-step approach with case study exercises. Each chapter includes an introduction to…

Regularities in the association of polymethacrylic acid with benzethonium chloride in aqueous solutions

NASA Astrophysics Data System (ADS)

Tugay, A. V.; Zakordonskiy, V. P.

2006-06-01

The association of cationogenic benzethonium chloride with polymethacrylic acid in aqueous solutions was studied by nephelometry, conductometry, tensiometry, viscometry, and pH-metry. The critical concentrations of aggregation and polymer saturation with the surface-active substance were determined. A model describing processes in such systems step by step was suggested.

Council Regulation (EC) No. 1099/2009: State of the Art and Its Application in a Local Health Unit in Piedmont, Italy

PubMed Central

Paolucci, Ginevra; Cagnasso, Daniela; Cassani, Francesco

2015-01-01

In the last decade, the European Union has reinforced the concept of animal welfare throughout the food chain, from breeding to slaughtering. Studies and assessments of economic nature led to the adoption of Regulation EC 1099/2009 and at the end of 2014 this regulation will be applied to all the members involved in the food chain. For this reason several local health units organized different initiatives. The local health unit of Turin no. 4 (ASLTO4) has developed a project aimed to train food business operators (FBO) to fulfill all the criteria developed in this Regulation. This initiative was divided into four steps: i) communication to the companies about the criteria of the new regulation; ii) a training course for official veterinarians; iii) slaughterhouse audits in order to get information about animal welfare; iv) and a training course for the personnel involved in slaughterhouses. The purpose of this paper was to report the results of the audits in order to identify critical points of structural, instrumental and documentary facilities. Then, the results can be compared with similar studies in order to develop common strategies and intervention areas. PMID:27800389

Automated Web-Based Request Mechanism for Workflow Enhancement in an Academic Customer-Focused Biorepository.

PubMed

McDonald, Sandra A; Ryan, Benjamin J; Brink, Amy; Holtschlag, Victoria L

2012-02-01

Informatics systems, particularly those that provide capabilities for data storage, specimen tracking, retrieval, and order fulfillment, are critical to the success of biorepositories and other laboratories engaged in translational medical research. A crucial item-one easily overlooked-is an efficient way to receive and process investigator-initiated requests. A successful electronic ordering system should allow request processing in a maximally efficient manner, while also allowing streamlined tracking and mining of request data such as turnaround times and numerical categorizations (user groups, funding sources, protocols, and so on). Ideally, an electronic ordering system also facilitates the initial contact between the laboratory and customers, while still allowing for downstream communications and other steps toward scientific partnerships. We describe here the recently established Web-based ordering system for the biorepository at Washington University Medical Center, along with its benefits for workflow, tracking, and customer service. Because of the system's numerous value-added impacts, we think our experience can serve as a good model for other customer-focused biorepositories, especially those currently using manual or non-Web-based request systems. Our lessons learned also apply to the informatics developers who serve such biobanks.

The global health concept of the German government: strengths, weaknesses, and opportunities.

PubMed

Bozorgmehr, Kayvan; Bruchhausen, Walter; Hein, Wolfgang; Knipper, Michael; Korte, Rolf; Razum, Oliver; Tinnemann, Peter

2014-01-01

Recognising global health as a rapidly emerging policy field, the German federal government recently released a national concept note for global health politics (July 10, 2013). As the German government could have a significant impact on health globally by making a coherent, evidence-informed, and long-term commitment in this field, we offer an initial appraisal of the strengths, weaknesses, and opportunities for development recognised in this document. We conclude that the national concept is an important first step towards the implementation of a coherent global health policy. However, important gaps were identified in the areas of intellectual property rights and access to medicines. In addition, global health determinants such as trade, economic crises, and liberalisation as well as European Union issues such as the health of migrants, refugees, and asylum seekers are not adequately addressed. Furthermore, little information is provided about the establishment of instruments to ensure an effective inter-ministerial cooperation. Finally, because implementation aspects for the national concept are critical for the success of this initiative, we call upon the newly elected 2013 German government to formulate a global health strategy, which includes a concrete plan of action, a time scale, and measurable goals.

Carbon Nanotube Chopped Fiber for Enhanced Properties in Additive Manufacturing

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

Menchhofer, Paul A.; Johnson, Joseph E.; Lindahl, John M.

2016-06-06

Nanocomp Technologies, Inc. is working with Oak Ridge National Laboratory to develop carbon nanotube (CNT) composite materials and evaluate their use in additive manufacturing (3D printing). The first phase demonstrated feasibility and improvements for carbon nanotube (CNT)- acrylonitrile butadiene styrene (ABS) composite filaments use in additive manufacturing, with potential future work centering on further improvements. By focusing the initial phase on standard processing methods (developed mainly for the incorporation of carbon fibers in ABS) and characterization techniques, a basis of knowledge for the incorporation of CNTs in ABS was learned. The ability to understand the various processing variables is criticalmore » to the successful development of these composites. From the degradation effects on ABS (caused by excessive temperatures), to the length of time the ABS is in the melt state, to the order of addition of constituents, and also to the many possible mixing approaches, a workable flow sequence that addresses each processing step is critical to the final material properties. Although this initial phase could not deal with each of these variables in-depth, a future study is recommended that will build on the lessons learned for this effort.« less

On the nucleation and initial film growth of rod-like organic molecules

NASA Astrophysics Data System (ADS)

Winkler, Adolf

2016-10-01

In this article, some fundamental topics related to the initial steps of organic film growth are reviewed. General conclusions will be drawn based on experimental results obtained for the film formation of oligophenylene and pentacene molecules on gold and mica substrates. Thin films were prepared via physical vapor deposition under ultrahigh-vacuum conditions and characterized in-situ mainly by thermal desorption spectroscopy, and ex-situ by X-ray diffraction and atomic force microscopy. In this short review article the following topics will be discussed: What are the necessary conditions to form island-like films which are either composed of flat-lying or of standing molecules? Does a wetting layer exist below and in between the islands? What is the reason behind the occasionally observed bimodal island size distribution? Can one describe the nucleation process with the diffusion-limited aggregation model? Do the impinging molecules directly adsorb on the surface or rather via a hot-precursor state? Finally, it will be described how the critical island size can be determined by an independent measurement of the deposition rate dependence of the island density and the capture-zone distribution via a universal relationship.

Automated Web-Based Request Mechanism for Workflow Enhancement in an Academic Customer-Focused Biorepository

PubMed Central

Ryan, Benjamin J.; Brink, Amy; Holtschlag, Victoria L.

2012-01-01

Informatics systems, particularly those that provide capabilities for data storage, specimen tracking, retrieval, and order fulfillment, are critical to the success of biorepositories and other laboratories engaged in translational medical research. A crucial item—one easily overlooked—is an efficient way to receive and process investigator-initiated requests. A successful electronic ordering system should allow request processing in a maximally efficient manner, while also allowing streamlined tracking and mining of request data such as turnaround times and numerical categorizations (user groups, funding sources, protocols, and so on). Ideally, an electronic ordering system also facilitates the initial contact between the laboratory and customers, while still allowing for downstream communications and other steps toward scientific partnerships. We describe here the recently established Web-based ordering system for the biorepository at Washington University Medical Center, along with its benefits for workflow, tracking, and customer service. Because of the system's numerous value-added impacts, we think our experience can serve as a good model for other customer-focused biorepositories, especially those currently using manual or non-Web–based request systems. Our lessons learned also apply to the informatics developers who serve such biobanks. PMID:23386921

Initiated chemical vapor deposition of thermoresponsive poly(N-vinylcaprolactam) thin films for cell sheet engineering.

PubMed

Lee, Bora; Jiao, Alex; Yu, Seungjung; You, Jae Bem; Kim, Deok-Ho; Im, Sung Gap

2013-08-01

Poly(N-vinylcaprolactam) (PNVCL) is a thermoresponsive polymer known to be nontoxic, water soluble and biocompatible. Here, PNVCL homopolymer was successfully synthesized for the first time by use of a one-step vapor-phase process, termed initiated chemical vapor deposition (iCVD). Fourier transform infrared spectroscopy results showed that radical polymerization took place from N-vinylcaprolactam monomers without damaging the functional caprolactam ring. A sharp lower critical solution temperature transition was observed at 31°C from the iCVD poly(N-vinylcaprolactam) (PNVCL) film. The thermoresponsive PNVCL surface exhibited a hydrophilic/hydrophobic alteration with external temperature change, which enabled the thermally modulated attachment and detachment of cells. The conformal coverage of PNVCL film on various substrates with complex topography, including fabrics and nanopatterns, was successfully demonstrated, which can further be utilized to fabricate cell sheets with aligned cell morphology. The advantage of this system is that cells cultured on such thermoresponsive surfaces could be recovered as an intact cell sheet by simply lowering the temperature, eliminating the need for conventional enzymatic treatments. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Neurocognitive predictors of financial capacity in traumatic brain injury.

PubMed

Martin, Roy C; Triebel, Kristen; Dreer, Laura E; Novack, Thomas A; Turner, Crystal; Marson, Daniel C

2012-01-01

To develop cognitive models of financial capacity (FC) in patients with traumatic brain injury (TBI). Longitudinal design. Inpatient brain injury rehabilitation unit. Twenty healthy controls, and 24 adults with moderate-to-severe TBI were assessed at baseline (30 days postinjury) and 6 months postinjury. The FC instrument (FCI) and a neuropsychological test battery. Univariate correlation and multiple regression procedures were employed to develop cognitive models of FCI performance in the TBI group, at baseline and 6-month time follow-up. Three cognitive predictor models of FC were developed. At baseline, measures of mental arithmetic/working memory and immediate verbal memory predicted baseline FCI performance (R = 0.72). At 6-month follow-up, measures of executive function and mental arithmetic/working memory predicted 6-month FCI performance (R = 0.79), and a third model found that these 2 measures at baseline predicted 6-month FCI performance (R = 0.71). Multiple cognitive functions are associated with initial impairment and partial recovery of FC in moderate-to-severe TBI patients. In particular, arithmetic, working memory, and executive function skills appear critical to recovery of FC in TBI. The study results represent an initial step toward developing a neurocognitive model of FC in patients with TBI.

On The Evolutionary Origin of Symbolic Communication

NASA Astrophysics Data System (ADS)

Grouchy, Paul; D'Eleuterio, Gabriele M. T.; Christiansen, Morten H.; Lipson, Hod

2016-10-01

The emergence of symbolic communication is often cited as a critical step in the evolution of Homo sapiens, language, and human-level cognition. It is a widely held assumption that humans are the only species that possess natural symbolic communication schemes, although a variety of other species can be taught to use symbols. The origin of symbolic communication remains a controversial open problem, obfuscated by the lack of a fossil record. Here we demonstrate an unbroken evolutionary pathway from a population of initially noncommunicating robots to the spontaneous emergence of symbolic communication. Robots evolve in a simulated world and are supplied with only a single channel of communication. When their ability to reproduce is motivated by the need to find a mate, robots evolve indexical communication schemes from initially noncommunicating populations in 99% of all experiments. Furthermore, 9% of the populations evolve a symbolic communication scheme allowing pairs of robots to exchange information about two independent spatial dimensions over a one-dimensional channel, thereby increasing their chance of reproduction. These results suggest that the ability for symbolic communication could have emerged spontaneously under natural selection, without requiring cognitive preadaptations or preexisting iconic communication schemes as previously conjectured.

The global health concept of the German government: strengths, weaknesses, and opportunities

PubMed Central

Bozorgmehr, Kayvan; Bruchhausen, Walter; Hein, Wolfgang; Knipper, Michael; Korte, Rolf; Razum, Oliver; Tinnemann, Peter

2014-01-01

Recognising global health as a rapidly emerging policy field, the German federal government recently released a national concept note for global health politics (July 10, 2013). As the German government could have a significant impact on health globally by making a coherent, evidence-informed, and long-term commitment in this field, we offer an initial appraisal of the strengths, weaknesses, and opportunities for development recognised in this document. We conclude that the national concept is an important first step towards the implementation of a coherent global health policy. However, important gaps were identified in the areas of intellectual property rights and access to medicines. In addition, global health determinants such as trade, economic crises, and liberalisation as well as European Union issues such as the health of migrants, refugees, and asylum seekers are not adequately addressed. Furthermore, little information is provided about the establishment of instruments to ensure an effective inter-ministerial cooperation. Finally, because implementation aspects for the national concept are critical for the success of this initiative, we call upon the newly elected 2013 German government to formulate a global health strategy, which includes a concrete plan of action, a time scale, and measurable goals. PMID:24560258

A 24-Week, Randomized, Controlled Study to Evaluate the Tolerability, Safety and Efficacy of 2 Different Titration Schemes of the Rivastigmine Patch in Japanese Patients with Mild to Moderate Alzheimer's Disease.

PubMed

Nakamura, Yu; Strohmaier, Christine; Tamura, Kaoru; Kataoka, Naoko; Nakano, Masayuki; Oda, Shoichiro; Nishimura, Kazuma; Homma, Akira

2015-01-01

To investigate whether 1-step titration of the rivastigmine patch (initiated at 5 cm(2) and titrated to 10 cm(2) after 4 weeks) is well tolerated in Japanese patients with Alzheimer's disease (AD) as compared to 3-step titration (initiated at 2.5 cm(2) and titrated by 2.5 cm(2) every 4 weeks to 10 cm(2)). A 24-week, multicenter, randomized, double-blind study was conducted in Japan between July 2012 and May 2014. Patients with mild to moderate AD aged 50-85 years were randomized 1:1 to 1-step or 3-step titration of the rivastigmine once-daily patch. The primary endpoint was the proportion of patients with adverse events leading to discontinuation. Of 216 patients randomized, 215 (1-step, n = 107; 3-step, n = 108) were included in the safety analysis. The primary endpoint outcome was 15.0% in the 1-step group and 18.5% in the 3-step group. The observed treatment difference was -3.6% (95% confidence interval: -17.0, 9.6), falling within the prespecified acceptance range. The tolerability of two different titration schemes was similar in Japanese patients with AD.

A 24-Week, Randomized, Controlled Study to Evaluate the Tolerability, Safety and Efficacy of 2 Different Titration Schemes of the Rivastigmine Patch in Japanese Patients with Mild to Moderate Alzheimer's Disease

PubMed Central

Nakamura, Yu; Strohmaier, Christine; Tamura, Kaoru; Kataoka, Naoko; Nakano, Masayuki; Oda, Shoichiro; Nishimura, Kazuma; Homma, Akira

2015-01-01

Aim To investigate whether 1-step titration of the rivastigmine patch (initiated at 5 cm2 and titrated to 10 cm2 after 4 weeks) is well tolerated in Japanese patients with Alzheimer's disease (AD) as compared to 3-step titration (initiated at 2.5 cm2 and titrated by 2.5 cm2 every 4 weeks to 10 cm2). Methods A 24-week, multicenter, randomized, double-blind study was conducted in Japan between July 2012 and May 2014. Patients with mild to moderate AD aged 50-85 years were randomized 1:1 to 1-step or 3-step titration of the rivastigmine once-daily patch. The primary endpoint was the proportion of patients with adverse events leading to discontinuation. Results Of 216 patients randomized, 215 (1-step, n = 107; 3-step, n = 108) were included in the safety analysis. The primary endpoint outcome was 15.0% in the 1-step group and 18.5% in the 3-step group. The observed treatment difference was −3.6% (95% confidence interval: −17.0, 9.6), falling within the prespecified acceptance range. Conclusion The tolerability of two different titration schemes was similar in Japanese patients with AD. PMID:26557135

Nucleosome occupancy as a novel chromatin parameter for replication origin functions

PubMed Central

Rodriguez, Jairo; Lee, Laura; Lynch, Bryony; Tsukiyama, Toshio

2017-01-01

Eukaryotic DNA replication initiates from multiple discrete sites in the genome, termed origins of replication (origins). Prior to S phase, multiple origins are poised to initiate replication by recruitment of the pre-replicative complex (pre-RC). For proper replication to occur, origin activation must be tightly regulated. At the population level, each origin has a distinct firing time and frequency of activation within S phase. Many studies have shown that chromatin can strongly influence initiation of DNA replication. However, the chromatin parameters that affect properties of origins have not been thoroughly established. We found that nucleosome occupancy in G1 varies greatly around origins across the S. cerevisiae genome, and nucleosome occupancy around origins significantly correlates with the activation time and efficiency of origins, as well as pre-RC formation. We further demonstrate that nucleosome occupancy around origins in G1 is established during transition from G2/M to G1 in a pre-RC-dependent manner. Importantly, the diminished cell-cycle changes in nucleosome occupancy around origins in the orc1-161 mutant are associated with an abnormal global origin usage profile, suggesting that proper establishment of nucleosome occupancy around origins is a critical step for regulation of global origin activities. Our work thus establishes nucleosome occupancy as a novel and key chromatin parameter for proper origin regulation. PMID:27895110

Crossing the chasm: information technology to biomedical informatics.

PubMed

Fahy, Brenda G; Balke, C William; Umberger, Gloria H; Talbert, Jeffery; Canales, Denise Niles; Steltenkamp, Carol L; Conigliaro, Joseph

2011-06-01

Accelerating the translation of new scientific discoveries to improve human health and disease management is the overall goal of a series of initiatives integrated in the National Institutes of Health (NIH) "Roadmap for Medical Research." The Clinical and Translational Science Award (CTSA) program is, arguably, the most visible component of the NIH Roadmap providing resources to institutions to transform their clinical and translational research enterprises along the goals of the Roadmap. The CTSA program emphasizes biomedical informatics as a critical component for the accomplishment of the NIH's translational objectives. To be optimally effective, emerging biomedical informatics programs must link with the information technology platforms of the enterprise clinical operations within academic health centers.This report details one academic health center's transdisciplinary initiative to create an integrated academic discipline of biomedical informatics through the development of its infrastructure for clinical and translational science infrastructure and response to the CTSA mechanism. This approach required a detailed informatics strategy to accomplish these goals. This transdisciplinary initiative was the impetus for creation of a specialized biomedical informatics core, the Center for Biomedical Informatics (CBI). Development of the CBI codified the need to incorporate medical informatics including quality and safety informatics and enterprise clinical information systems within the CBI. This article describes the steps taken to develop the biomedical informatics infrastructure, its integration with clinical systems at one academic health center, successes achieved, and barriers encountered during these efforts.

Measured close lightning leader-step electric-field-derivative waveforms.

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

Jordan, Doug M.; Hill, Dustin; Biagi, Christopher J.

2010-12-01

We characterize the measured electric field-derivative (dE/dt) waveforms of lightning stepped-leader steps from three negative lightning flashes at distances of tens to hundreds of meters. Electromagnetic signatures of leader steps at such close distances have rarely been documented in previous literature. Individual leader-step three-dimensional locations are determined by a dE/dt TOA system. The leader-step field derivative is typically a bipolar pulse with a sharp initial half-cycle of the same polarity as that of the return stroke, followed by an opposite polarity overshoot that decays relatively slowly to background level. This overshoot increases in amplitude relative to the initial peak andmore » becomes dominant as range decreases. The initial peak is often preceded by a 'slow front,' similar to the slow front that precedes the fast transition to peak in first return stroke dE/dt and E waveforms. The overall step-field waveform duration is typically less than 1 {micro}s. The mean initial peak of dE/dt, range-normalized to 100 km, is 7.4 V m{sup -1} {micro}s{sup -1} (standard deviation (S.D.), 3.7 V m{sup -1} {micro}s{sup -1}, N = 103), the mean half-peak width is 33.5 ns (S.D., 11.9 ns, N = 69), and the mean 10-to-90% risetime is 43.6 ns (S.D., 24.2 ns, N = 69). From modeling, we determine the properties of the leader step currents which produced two typical measured field derivatives, and we use one of these currents to calculate predicted leader step E and dE/dt as a function of source range and height, the results being in good agreement with our observations. The two modeled current waveforms had maximum rates of current rise-to-peak near 100 kA {micro}s{sup -1}, peak currents in the 5-7 kA range, current half-peak widths of about 300 ns, and charge transfers of {approx}3 mC. As part of the modeling, those currents were propagated upward at 1.5 x 10{sup 8} m s{sup -1}, with their amplitudes decaying exponentially with a decay height constant of 25 m.« less

Critical Race Theory and the Whiteness of Teacher Education

ERIC Educational Resources Information Center

Sleeter, Christine E.

2017-01-01

This article uses three tenets of critical race theory to critique the common pattern of teacher education focusing on preparing predominantly White cohorts of teacher candidates for racially and ethnically diverse students. The tenet of interest convergence asks how White interests are served through incremental steps. The tenet of color…

Using Digital Comics to Develop Digital Literacy: Fostering Functionally, Critically, and Rhetorically Literate Students

ERIC Educational Resources Information Center

Kirchoff, Jeff

2017-01-01

Literacy scholarship has established the importance of teaching, supporting, and facilitating digital literacy education for 21st century students. Stuart Selber goes a step further, arguing that students must be functionally (using digital technology), critically (questioning digital technology), and rhetorically (producing effective digital…

Natural Genetic Variation in Selected Populations of Arabidopsis thaliana is Associated with Ionomic Differences

USDA-ARS?s Scientific Manuscript database

Controlling elemental composition is critical for plant growth and development as well as the nutrition of humans who utilize plants for food. Uncovering the genes that underpin mineral ion homeostasis in plants is a critical first step towards understanding the biochemical networks that regulate a ...

Older Women in the Academy: Games We Learn To Play Coping with Systems of Inequity.

ERIC Educational Resources Information Center

Erickson, Jacqueline M.

This critical qualitative study explored the obstacles older women encounter as they pursue doctorates. Introductory material identifies steps in a critical qualitative approach including monological data collection, preliminary reconstructive analysis, dialogical data generation, and description and explanation of system relationships. Four women…

Beyond Composite Scores and Cronbach's Alpha: Advancing Methodological Rigor in Recreation Research

ERIC Educational Resources Information Center

Gagnon, Ryan J.; Stone, Garrett A.; Garst, Barry A.

2017-01-01

Critically examining common statistical approaches and their strengths and weaknesses is an important step in advancing recreation and leisure sciences. To continue this critical examination and to inform methodological decision making, this study compared three approaches to determine how alternative approaches may result in contradictory…

Master Logic Diagram: An Approach to Identify Initiating Events of HTGRs

NASA Astrophysics Data System (ADS)

Purba, J. H.

2018-02-01

Initiating events of a nuclear power plant being evaluated need to be firstly identified prior to applying probabilistic safety assessment on that plant. Various types of master logic diagrams (MLDs) have been proposedforsearching initiating events of the next generation of nuclear power plants, which have limited data and operating experiences. Those MLDs are different in the number of steps or levels and different in the basis for developing them. This study proposed another type of MLD approach to find high temperature gas cooled reactor (HTGR) initiating events. It consists of five functional steps starting from the top event representing the final objective of the safety functions to the basic event representing the goal of the MLD development, which is an initiating event. The application of the proposed approach to search for two HTGR initiating events, i.e. power turbine generator trip and loss of offsite power, is provided. The results confirmed that the proposed MLD is feasiblefor finding HTGR initiating events.

Detection of Protein SUMOylation In Situ by Proximity Ligation Assays.

PubMed

Sahin, Umut; Jollivet, Florence; Berthier, Caroline; de Thé, Hugues; Lallemand-Breitenbach, Valérie

2016-01-01

Sumoylation is a posttranslational process essential for life and concerns a growing number of crucial proteins. Understanding the influence of this phenomenon on individual proteins or on cellular pathways in which they function has become an intense area of research. A critical step in studying protein sumoylation is to detect sumoylated forms of a particular protein. This has proven to be a challenging task for a number of reasons, especially in the case of endogenous proteins and in vivo studies or when studying rare cells such as stem cells. Proximity ligation assays that allow detection of closely interacting protein partners can be adapted for initial detection of endogenous sumoylation or ubiquitination in a rapid, ultrasensitive, and cheap manner. In addition, modified forms of a given protein can be detected in situ in various cellular compartments. Finally, the flexibility of this technique may allow rapid screening of drugs and stress signals that may modulate protein sumoylation.

Prolactin receptor in regulation of neuronal excitability and channels

PubMed Central

Patil, Mayur J; Henry, Michael A; Akopian, Armen N

2014-01-01

Prolactin (PRL) activates PRL receptor isoforms to exert regulation of specific neuronal circuitries, and to control numerous physiological and clinically-relevant functions including; maternal behavior, energy balance and food intake, stress and trauma responses, anxiety, neurogenesis, migraine and pain. PRL controls these critical functions by regulating receptor potential thresholds, neuronal excitability and/or neurotransmission efficiency. PRL also influences neuronal functions via activation of certain neurons, resulting in Ca2+ influx and/or electrical firing with subsequent release of neurotransmitters. Although PRL was identified almost a century ago, very little specific information is known about how PRL regulates neuronal functions. Nevertheless, important initial steps have recently been made including the identification of PRL-induced transient signaling pathways in neurons and the modulation of neuronal transient receptor potential (TRP) and Ca2+-dependent K+ channels by PRL. In this review, we summarize current knowledge and recent progress in understanding the regulation of neuronal excitability and channels by PRL. PMID:24758841

Care team identification in the electronic health record: A critical first step for patient-centered communication.

PubMed

Dalal, Anuj K; Schnipper, Jeffrey L

2016-05-01

Patient-centered communication is essential to coordinate care and safely progress patients from admission through discharge. Hospitals struggle with improving the complex and increasingly electronic conversation patterns among care team members, patients, and caregivers to achieve effective patient-centered communication across settings. Accurate and reliable identification of all care team members is a precursor to effective patient-centered communication and ideally should be facilitated by the electronic health record. However, the process of identifying care team members is challenging, and team lists in the electronic health record are typically neither accurate nor reliable. Based on the literature and on experience from 2 initiatives at our institution, we outline strategies to improve care team identification in the electronic health record and discuss potential implications for patient-centered communication. Journal of Hospital Medicine 2016;11:381-385. © 2016 Society of Hospital Medicine. © 2016 Society of Hospital Medicine.

Recommended Practices in Thrust Measurements

NASA Technical Reports Server (NTRS)

Polk, James E.; Pancotti, Anthony; Haag, Thomas; King, Scott; Walker, Mitchell; Blakely, Joseph; Ziemer, John

2013-01-01

Accurate, direct measurement of thrust or impulse is one of the most critical elements of electric thruster characterization, and one of the most difficult measurements to make. The American Institute of Aeronautics and Astronautics has started an initiative to develop standards for many important measurement processes in electric propulsion, including thrust measurements. This paper summarizes recommended practices for the design, calibration, and operation of pendulum thrust stands, which are widely recognized as the best approach for measuring micro N- to mN-level thrust and micro Ns-level impulse bits. The fundamentals of pendulum thrust stand operation are reviewed, along with its implementation in hanging pendulum, inverted pendulum, and torsional balance configurations. Methods of calibration and recommendations for calibration processes are presented. Sources of error are identified and methods for data processing and uncertainty analysis are discussed. This review is intended to be the first step toward a recommended practices document to help the community produce high quality thrust measurements.

Rabbit genome analysis reveals a polygenic basis for phenotypic change during domestication.

PubMed

Carneiro, Miguel; Rubin, Carl-Johan; Di Palma, Federica; Albert, Frank W; Alföldi, Jessica; Martinez Barrio, Alvaro; Pielberg, Gerli; Rafati, Nima; Sayyab, Shumaila; Turner-Maier, Jason; Younis, Shady; Afonso, Sandra; Aken, Bronwen; Alves, Joel M; Barrell, Daniel; Bolet, Gerard; Boucher, Samuel; Burbano, Hernán A; Campos, Rita; Chang, Jean L; Duranthon, Veronique; Fontanesi, Luca; Garreau, Hervé; Heiman, David; Johnson, Jeremy; Mage, Rose G; Peng, Ze; Queney, Guillaume; Rogel-Gaillard, Claire; Ruffier, Magali; Searle, Steve; Villafuerte, Rafael; Xiong, Anqi; Young, Sarah; Forsberg-Nilsson, Karin; Good, Jeffrey M; Lander, Eric S; Ferrand, Nuno; Lindblad-Toh, Kerstin; Andersson, Leif

2014-08-29

The genetic changes underlying the initial steps of animal domestication are still poorly understood. We generated a high-quality reference genome for the rabbit and compared it to resequencing data from populations of wild and domestic rabbits. We identified more than 100 selective sweeps specific to domestic rabbits but only a relatively small number of fixed (or nearly fixed) single-nucleotide polymorphisms (SNPs) for derived alleles. SNPs with marked allele frequency differences between wild and domestic rabbits were enriched for conserved noncoding sites. Enrichment analyses suggest that genes affecting brain and neuronal development have often been targeted during domestication. We propose that because of a truly complex genetic background, tame behavior in rabbits and other domestic animals evolved by shifts in allele frequencies at many loci, rather than by critical changes at only a few domestication loci. Copyright © 2014, American Association for the Advancement of Science.

Accelerated leukemogenesis by truncated CBFβ-SMMHC defective in high-affinity binding with RUNX1

PubMed Central

Kamikubo, Yasuhiko; Zhao, Ling; Wunderlich, Mark; Corpora, Takeshi; Hyde, R. Katherine; Paul, Thomas A.; Kundu, Mondira; Garrett, Lisa; Compton, Sheila; Huang, Gang; Wolff, Linda; Ito, Yoshiaki; Bushweller, John; Mulloy, James C.; Liu, P. Paul

2010-01-01

SUMMARY Dominant RUNX1 inhibition has been proposed as a common pathway for CBF-leukemia. CBFβ-SMMHC, a fusion protein in human acute myeloid leukemia (AML), dominantly inhibits RUNX1 largely through its RUNX1 high-affinity binding domain (HABD). However, the type I CBFβ-SMMHC fusion in AML patients lacks HABD. Here we report that the type I CBFβ-SMMHC protein binds RUNX1 inefficiently. Knock-in mice expressing CBFβ-SMMHC with a HABD deletion developed leukemia quickly, even though hematopoietic defects associated with Runx1-inhibition were partially rescued. A larger pool of leukemia initiating cells, increased MN1 expression, and retention of RUNX1 phosphorylation are potential mechanisms for accelerated leukemia development in these mice. Our data suggest that RUNX1 dominant inhibition may not be a critical step for leukemogenesis by CBFβ-SMMHC. PMID:20478528

New tools for sculpting cranial implants in a shared haptic augmented reality environment.

PubMed

Ai, Zhuming; Evenhouse, Ray; Leigh, Jason; Charbel, Fady; Rasmussen, Mary

2006-01-01

New volumetric tools were developed for the design and fabrication of high quality cranial implants from patient CT data. These virtual tools replace time consuming physical sculpting, mold making and casting steps. The implant is designed by medical professionals in tele-immersive collaboration. Virtual clay is added in the virtual defect area on the CT data using the adding tool. With force feedback the modeler can feel the edge of the defect and fill only the space where no bone is present. A carving tool and a smoothing tool are then used to sculpt and refine the implant. To make a physical evaluation, the skull with simulated defect and the implant are fabricated via stereolithography to allow neurosurgeons to evaluate the quality of the implant. Initial tests demonstrate a very high quality fit. These new haptic volumetric sculpting tools are a critical component of a comprehensive tele-immersive system.

Cases of ergotism in livestock and associated ergot alkaloid concentrations in feed

NASA Astrophysics Data System (ADS)

Craig, A.; Klotz, James; Duringer, Jennifer

2015-02-01

Ergot-induced disease was known long before Biblical times and has been the root cause for countless human epidemics spanning from the early fourteenth century to the late sixteenth century. In contrast, many of these same ergot alkaloids have been utilized for their medicinal properties to mitigate migraine headaches and have had indications as anticarcinogens. Although ergot alkaloids have been used for centuries, basic pharmacokinetic data has not been documented for clinical disease. Consequently, a threshold dose and accurate dose-response data have yet to be established. Throughout the past several years, new detection techniques have emerged to detect these alkaloids at the parts per billion which have allowed for new efforts to be made with respect to determining threshold levels and making accurate clinical diagnoses. This perspectives article provides a critical initial step for establishing a uniform interpretation of ergot toxicosis from limited existing data.

Application of the Newell liberal arts model for interdisciplinary course design and implementation.

PubMed

Haas, Barbara Ann; Sheehan, Judith M; Stone, Jennie Ann M; Hammer-Beem, Marji J

2009-10-01

Health professions faculty think that interdisciplinary education is critical for students pursuing careers as health care professionals. Initial attempts at interdisciplinary education by simply combining students into groups without adequate curriculum adaptation, preparation, and planning have been ineffective. Applying the liberal arts interdisciplinary model, developed by William Newell, a transdisciplinary faculty team in the College of Health Professions of the University of New England identified the course content, design, and instructional processes necessary to create an interdisciplinary elective course. The eight-step model and how it was applied to the development of an ethics course for seven different health care professional disciplines is presented. The result of this applied design approach was a course that assisted the transition of health care professional students previously accustomed to studying and working within their own discipline to communicate, cooperate, and collaborate across discipline-specific lines. Copyright 2009, SLACK Incorporated.

Quantum computing with defects.

PubMed

Weber, J R; Koehl, W F; Varley, J B; Janotti, A; Buckley, B B; Van de Walle, C G; Awschalom, D D

2010-05-11

Identifying and designing physical systems for use as qubits, the basic units of quantum information, are critical steps in the development of a quantum computer. Among the possibilities in the solid state, a defect in diamond known as the nitrogen-vacancy (NV(-1)) center stands out for its robustness--its quantum state can be initialized, manipulated, and measured with high fidelity at room temperature. Here we describe how to systematically identify other deep center defects with similar quantum-mechanical properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate defect systems. To illustrate these points in detail, we compare electronic structure calculations of the NV(-1) center in diamond with those of several deep centers in 4H silicon carbide (SiC). We then discuss the proposed criteria for similar defects in other tetrahedrally coordinated semiconductors.

Reduced opsin gene expression in a cave-dwelling fish

PubMed Central

Tobler, Michael; Coleman, Seth W.; Perkins, Brian D.; Rosenthal, Gil G.

2010-01-01

Regressive evolution of structures associated with vision in cave-dwelling organisms is the focus of intense research. Most work has focused on differences between extreme visual phenotypes: sighted, surface animals and their completely blind, cave-dwelling counterparts. We suggest that troglodytic systems, comprising multiple populations that vary along a gradient of visual function, may prove critical in understanding the mechanisms underlying initial regression in visual pathways. Gene expression assays of natural and laboratory-reared populations of the Atlantic molly (Poecilia mexicana) revealed reduced opsin expression in cave-dwelling populations compared with surface-dwelling conspecifics. Our results suggest that the reduction in opsin expression in cave-dwelling populations is not phenotypically plastic but reflects a hardwired system not rescued by exposure to light during retinal ontogeny. Changes in opsin gene expression may consequently represent a first evolutionary step in the regression of eyes in cave organisms. PMID:19740890

Mobile DNA in the pathogenic Neisseria

PubMed Central

Obergfell, Kyle P.; Seifert, H. Steven

2015-01-01

The genus Neisseria contains two pathogenic species of notable public health concern: Neisseria gonorrhoeae and Neisseria meningitidis. These pathogens display a notable ability to undergo frequent programmed recombination events. The recombination mediated pathways of transformation and pilin antigenic variation in the Neisseria are well studied systems that are critical for pathogenesis. Here we will detail the conserved and unique aspects of transformation and antigenic variation in the Neisseria. Transformation will be followed from initial DNA binding through recombination into the genome with consideration to the factors necessary at each step. Additional focus is paid to the unique type IV secretion system that mediates donation of transforming DNA in the pathogenic Neisseria. The pilin antigenic variation system uses programed recombinations to alter a major surface determinant which allows immune avoidance and promotes infection. We discuss the trans- and cis- acting factors which facilitate pilin antigenic variation and present the current understanding of the mechanisms involved in the process. PMID:25866700

Two men with multiple disabilities carry out an assembly work activity with the support of a technology system.

PubMed

Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Green, Vanessa A; Oliva, Doretta; Campodonico, Francesca

2013-10-01

To assess whether two persons with multiple disabilities could learn a work activity (i.e., assembling trolley wheels) with the support of a technology system. After an initial baseline, the study compared the effects of intervention sessions relying on the technology system (which called the participants to the different workstations and provided feedback and final stimulation) with the effects of intervention sessions carried out without technology. The two types of intervention sessions were conducted according to an alternating treatments design. Eventually, only intervention sessions relying on the technology system were used. Both participants managed to assemble wheels independently during intervention sessions relying on the technology system while they failed during sessions without the system. Their performance was strengthened during the final part of the study, in which only sessions with the system occurred. Technology may be critical in helping persons with multiple disabilities manage multi-step work activities.

Large scale extraction of poly(3-hydroxybutyrate) from Ralstonia eutropha H16 using sodium hypochlorite

PubMed Central

2012-01-01

Isolation of polyhydroxyalkanoates (PHAs) from bacterial cell matter is a critical step in order to achieve a profitable production of the polymer. Therefore, an extraction method must lead to a high recovery of a pure product at low costs. This study presents a simplified method for large scale poly(3-hydroxybutyrate), poly(3HB), extraction using sodium hypochlorite. Poly(3HB) was extracted from cells of Ralstonia eutropha H16 at almost 96% purity. At different extraction volumes, a maximum recovery rate of 91.32% was obtained. At the largest extraction volume of 50 L, poly(3HB) with an average purity of 93.32% ± 4.62% was extracted with a maximum recovery of 87.03% of the initial poly(3HB) content. This process is easy to handle and requires less efforts than previously described processes. PMID:23164136

Pharmacogenetics and personalised medicine: maintain a critical approach.

PubMed

2013-06-01

The purpose of pharmacogenetics is to offer"personalised" treatment, in which a drug is only prescribed to patients in whom it is very likely to be effective, or to withhold a drug from patients at increased risk of adverse effects. Pharmacogenetics requires the use of genetic tests which, as with any other diagnostic test, must be evaluated for their discriminatory power (sensitivity, specificity, etc.). These evaluations are sometimes biased. Pharmacogenetics has been heralded as a means of tailoring cancer therapy. However large clinical trials with demanding clinical endpoints are often disappointing, despite initially encouraging results. Pharmacogenetic information is included in many summaries of product characteristics for non-cancer drugs, mainly in order to reduce the frequency of certain serious adverse effects. In summary, pharmacogenetics theoretically represents a step forward but must be evaluated in rigorous clinical trials, as is the case with all other "therapeutic tools".

Application of point kinetics equations to the design of a reactivity meter

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

Binney, S.E.; Bakir, A.J.M.

1988-01-01

The time-dependent reactivity of a nuclear reactor is obviously one of the most important reactor parameters that describes the state of the reactor. Although several different types of techniques exist to measure reactivity, only the kinetic method is described here. The paper illustrates the measured reactor power and calculated reactivity for a 70 cents step change in reactivity. These data were taken at 1-s time intervals. It is seen that the reactivity, initially at zero, rises rapidly to a predetermined value (determined by the reactivity change induced in the system) and then returns to zero as the reactor is reestablishedmore » in a critical situation by insertion of another control rod. It is concluded that the method of Tuttle has been adapted to produce a reliable, on-line calculation of reactivity from a time-dependent reactor power signal.« less

[Practical approach to infection control and antimicrobial stewardship by medical technologists].

PubMed

Komori, Toshiaki; Yamada, Yukiji; Kimura, Takeshi; Kosaka, Tadashi; Nakanishi, Masaki; Fujitomo, Yumiko; Fujita, Naohisa

2013-04-01

Since establishing an antimicrobial management team (AMT) in 2003, we have been promoting both appropriate diagnosis and treatment and improving the prognosis of hospitalized patients with infections. AMT is composed of 4 doctors, 2 nurses, 2 pharmacists and one medical technologist. AMT members meet twice a week and discuss patients with positive blood cultures, with prescribed anti-MRSA drugs and suspected infections. Antimicrobial prescription and clinical laboratory data are obtained from the database of electric medical records and microbiological data from the laboratory database system. The initial step in infection control and antimicrobial stewardship is an accurate diagnosis of infection. Clinical microbiology laboratories play a critical role in infection control and antimicrobial stewardship by reporting accurate and timely results of both bacterial identification and antimicrobial susceptibility tests. Medical technologists are required to develop better competency and proficiency about clinical microbiology in both infection control and antimicrobial stewardship.

Call for participation in the neurogenetics consortium within the Human Variome Project.

PubMed

Haworth, Andrea; Bertram, Lars; Carrera, Paola; Elson, Joanna L; Braastad, Corey D; Cox, Diane W; Cruts, Marc; den Dunnen, Johann T; Farrer, Matthew J; Fink, John K; Hamed, Sherifa A; Houlden, Henry; Johnson, Dennis R; Nuytemans, Karen; Palau, Francesc; Rayan, Dipa L Raja; Robinson, Peter N; Salas, Antonio; Schüle, Birgitt; Sweeney, Mary G; Woods, Michael O; Amigo, Jorge; Cotton, Richard G H; Sobrido, Maria-Jesus

2011-08-01

The rate of DNA variation discovery has accelerated the need to collate, store and interpret the data in a standardised coherent way and is becoming a critical step in maximising the impact of discovery on the understanding and treatment of human disease. This particularly applies to the field of neurology as neurological function is impaired in many human disorders. Furthermore, the field of neurogenetics has been proven to show remarkably complex genotype-to-phenotype relationships. To facilitate the collection of DNA sequence variation pertaining to neurogenetic disorders, we have initiated the "Neurogenetics Consortium" under the umbrella of the Human Variome Project. The Consortium's founding group consisted of basic researchers, clinicians, informaticians and database creators. This report outlines the strategic aims established at the preliminary meetings of the Neurogenetics Consortium and calls for the involvement of the wider neurogenetic community in enabling the development of this important resource.

The state-of-the-art port of entry workshop

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

Godfrey, B.

1995-05-01

The increased demand for freight movements through international ports of entry and the signing of the North American Free Trade Agreement (NAFTA) have increased freight traffic at border ports of entry. The State-of-the-Art Port of Entry Workshop initiated a dialogue among technologists and stakeholders to explore the potential uses of technology at border crossings and to set development priorities. International ports of entry are both information and labor intensive, and there are many promising technologies that could be used to provide timely information and optimize inspection resources. Participants universally held that integration of technologies and operations is critical to improvingmore » port services. A series of Next Steps was developed to address stakeholder issues and national priorities, such as the National Transportation Policy and National Drug Policy. This report documents the views of the various stakeholders and technologists present at the workshop and outlines future directions of study.« less

Using a critical reflection process to create an effective learning community in the workplace.

PubMed

Walker, Rachel; Cooke, Marie; Henderson, Amanda; Creedy, Debra K

2013-05-01

Learning circles are an enabling process to critically examine and reflect on practices with the purpose of promoting individual and organizational growth and change. The authors adapted and developed a learning circle strategy to facilitate open discourse between registered nurses, clinical leaders, clinical facilitators and students, to critically reflect on practice experiences to promote a positive learning environment. This paper reports on an analysis of field notes taken during a critical reflection process used to create an effective learning community in the workplace. A total of 19 learning circles were conducted during in-service periods (that is, the time allocated for professional education between morning and afternoon shifts) over a 3 month period with 56 nurses, 33 students and 1 university-employed clinical supervisor. Participation rates ranged from 3 to 12 individuals per discussion. Ten themes emerged from content analysis of the clinical learning issues identified through the four-step model of critical reflection used in learning circle discussions. The four-step model of critical reflection allowed participants to reflect on clinical learning issues, and raise them in a safe environment that enabled topics to be challenged and explored in a shared and cooperative manner. Copyright © 2012 Elsevier Ltd. All rights reserved.

Classical evolution of fractal measures on the lattice

NASA Astrophysics Data System (ADS)

Antoniou, N. G.; Diakonos, F. K.; Saridakis, E. N.; Tsolias, G. A.

2007-04-01

We consider the classical evolution of a lattice of nonlinear coupled oscillators for a special case of initial conditions resembling the equilibrium state of a macroscopic thermal system at the critical point. The displacements of the oscillators define initially a fractal measure on the lattice associated with the scaling properties of the order parameter fluctuations in the corresponding critical system. Assuming a sudden symmetry breaking (quench), leading to a change in the equilibrium position of each oscillator, we investigate in some detail the deformation of the initial fractal geometry as time evolves. In particular, we show that traces of the critical fractal measure can be sustained for large times, and we extract the properties of the chain that determine the associated time scales. Our analysis applies generally to critical systems for which, after a slow developing phase where equilibrium conditions are justified, a rapid evolution, induced by a sudden symmetry breaking, emerges on time scales much shorter than the corresponding relaxation or observation time. In particular, it can be used in the fireball evolution in a heavy-ion collision experiment, where the QCD critical point emerges, or in the study of evolving fractals of astrophysical and cosmological scales, and may lead to determination of the initial critical properties of the Universe through observations in the symmetry-broken phase.

Rolling Out Xpert® MTB/RIF for TB Detection in HIV-Infected Populations:An Opportunity for Systems Strengthening.

PubMed

Pathmanathan, Ishani; Date, Anand; Coggin, William L; Nkengasong, John; Piatek, Amy S; Alexander, Heather

2017-03-31

To eliminate preventable deaths, disease and suffering due to tuberculosis (TB), improved diagnostic capacity is critical. The Cepheid Xpert ® MTB/RIF assay is recommended by the World Health Organization as the initial diagnostic test for people with suspected HIV-associated TB. However, despite high expectations, its scale-up in real-world settings has faced challenges, often due to the systems that support it. In this commentary we discuss needs and opportunities for systems strengthening to support widespread scale-up of Xpert ® MTB/RIF as they relate to each step within the TB diagnostic cascade, from finding presumptive patients, to collecting, transporting and testing sputum specimens, to reporting and receiving results, to initiating and monitoring treatment and, ultimately, to ensuring successful and timely treatment and cure. Investments in evidence-based interventions at each step along the cascade and within the system as a whole will augment not only the utility of Xpert ® MTB/RIF, but also the successful implementation of future diagnostic tests. Xpert ® MTB/RIF will only improve patient outcomes if optimally implemented within the context of strong TB programs and systems. Roll-out of this technology to people living with HIV and others in resource-limited settings offers the opportunity to leverage current TB and HIV laboratory, diagnostic and programmatic investments, while also addressing challenges and strengthening coordination between laboratory systems, laboratory-program interfaces, and TB-HIV program interfaces. If successful, the benefits of this tool could extend beyond progress towards global End TB Strategy goals, to improve system-wide capacity for global disease detection and control.

Roles of Copper and a Conserved Aspartic Acid in the Autocatalytic Hydroxylation of a Specific Tryptophan Residue during Cysteine Tryptophylquinone Biogenesis.

PubMed

Williamson, Heather R; Sehanobish, Esha; Shiller, Alan M; Sanchez-Amat, Antonio; Davidson, Victor L

2017-02-21

The first posttranslational modification step in the biosynthesis of the tryptophan-derived quinone cofactors is the autocatalytic hydroxylation of a specific Trp residue at position C-7 on the indole side chain. Subsequent modifications are catalyzed by modifying enzymes, but the mechanism by which this first step occurs is unknown. LodA possesses a cysteine tryptophylquinone (CTQ) cofactor. Metal analysis as well as spectroscopic and kinetic studies of the mature and precursor forms of a D512A LodA variant provides evidence that copper is required for the initial hydroxylation of the precursor protein and that if alternative metals are bound, the modification does not occur and the precursor is unstable. It is shown that the mature native LodA also contains loosely bound copper, which affects the visible absorbance spectrum and quenches the fluorescence spectrum that is attributed to the mature CTQ cofactor. When copper is removed, the fluorescence appears, and when it is added back to the protein, the fluorescence is quenched, indicating that copper reversibly binds in the proximity of CTQ. Removal of copper does not diminish the enzymatic activity of LodA. This distinguishes LodA from enzymes with protein-derived tyrosylquinone cofactors in which copper is present near the cofactor and is absolutely required for activity. Mechanisms are proposed for the role of copper in the hydroxylation of the unactivated Trp side chain. These results demonstrate that the reason that the highly conserved Asp512 is critical for LodA, and possibly all tryptophylquinone enzymes, is not because it is required for catalysis but because it is necessary for CTQ biosynthesis, more specifically to facilitate the initial copper-dependent hydroxylation of a specific Trp residue.

The New Hampshire Ten Steps to Successful Breastfeeding Collaborative: A Statewide QI Initiative.

PubMed

Whalen, Bonny L; Kelly, Joyce; Holmes, Alison Volpe

2015-06-01

Despite national recognition for their breastfeeding-friendly practices, many New Hampshire hospitals are still not achieving the Ten Steps to Successful Breastfeeding. To increase achievement of the Ten Steps in New Hampshire's birthing hospitals, facilitate Baby-Friendly Hospital Initiative (BFHI) designation for interested hospitals, and improve rates of in-hospital any and exclusive breastfeeding. After a 2010 needs assessment, we conducted 2 statewide workshops targeting 6 of the Ten Steps found to be most deficient among New Hampshire birthing hospitals. Eighteen of 20 hospitals attended at least 1 workshop, and 6 participated in an intensive collaborative. In 2013, we analyzed interval Ten Step achievement and in-hospital breastfeeding trends. Staff education showed the greatest improvement, increasing step 2 achievement from 1 to 6 hospitals (P=.05). Although the number of hospitals implementing step 6 (breast milk only) and step 9 (no artificial nipples) increased, differences were not statistically significant. Intensive collaborative hospitals achieved an average of 1.5 new steps, whereas non-Baby Friendly hospitals lost 0.7 steps (P=.05). In-hospital breastfeeding rates increased in intensive collaborative hospitals and were significantly higher than those in non-Baby Friendly hospitals by the end of the study (any breastfeeding, 89% vs 73%, P=.03; exclusive breastfeeding, 84% vs 61%, P<.001). A statewide improvement collaborative facilitated increases in Ten Step achievement and in-hospital breastfeeding for hospitals participating in an intensive collaborative. Active work in Ten Step implementation, including staff education, appears to be more effective in increasing in-hospital breastfeeding than does BFHI designation alone. Copyright © 2015 by the American Academy of Pediatrics.

Persistent hypertransaminasemia in asymptomatic children: A stepwise approach

PubMed Central

Vajro, Pietro; Maddaluno, Sergio; Veropalumbo, Claudio

2013-01-01

We aimed to examine the major causes of isolated chronic hypertransaminasemia in asymptomatic children and develop a comprehensive diagnostic flow diagram. A MEDLINE search inclusive of publications throughout August 2012 was performed. We found only a small number of publications that had comprehensively investigated this topic. Consequently, it was difficult to construct a diagnostic flowchart similar to those already available for adults. In children, a “retesting panel” prescription, including gamma-glutamyl transpeptidase and creatine kinase in addition to aminotransferases, is considered a reasonable approach for proficiently confirming the persistence of the abnormality, ruling out cholestatic hepatopathies and myopathies, and guiding the subsequent diagnostic steps. If re-evaluation of physical and historical findings suggests specific etiologies, then these should be evaluated in the initial enzyme retesting panel. A simple multi-step diagnostic algorithm incorporating a large number of possible pediatric scenarios, in addition to the few common to adults, is available. Accurately classifying a child with asymptomatic persistent hypertransaminasemia may be a difficult task, but the results are critical for preventing the progression of an underlying, possibly occult, condition later in childhood or during transition. Given the high benefit/cost ratio of preventing hepatic deterioration, no effort should be spared in diagnosing and properly treating each case of persistent hypertransaminasemia in pediatric patients. PMID:23687411

Studying Policy Changes in Disaster Management in India: A Tale of Two Cyclones.

PubMed

Jha, Ayan; Basu, Rivu; Basu, Atreyee

2016-02-01

The mainstay of India's disaster management policy until the early 2000s had been relief and rescue operations. The Odisha Super Cyclone (1999) with 10,000 deaths and US $3 billion economic damage provided a rude awakening. Recognizing the importance of preemptive preparedness, the government initiated systematic steps to implement a national framework interlinking economic, environmental, and overall developmental issues for efficient response to and mitigation of disasters. We attempted a critical analysis of this paradigm shift in India's disaster management policy through the prism of 2 cyclones, 14 years apart in time. With improved preparedness and response measures, the death toll in 2013 Cyclone Phailin was 0.5% and the economic loss was about one-third of that during 1999. Concomitant improvements in the technological expertise of the early warning system, an integrated approach at all levels of administration including joint planning with major nongovernmental organizations, and improved community participation were identified as game-changers. An unbelievable 1 million people were evacuated to safety. Our essay aims to highlight key steps in this success and calls for futuristic approaches like insurance programs and gender-sensitive recovery plans. With thorough scrutiny, India's model may well stand to be replicated in resource-restricted settings.

Electron nanoprobe induced oxidation: A simulation of direct-write purification

DOE PAGES

Fowlkes, J. D.; Geier, B.; Lewis, B. B.; ...

2015-06-01

Electron beam direct-write has recently taken a large step forward with the advent of methods to purify deposits. This development has opened the door for future direct-write device prototyping and editing. In one such approach, an additional beam scanning procedure removes carbonaceous impurities via oxidation from metal–carbon deposits (e.g., PtC 5) in the presence of H 2O or O 2 after deposition. So far, critical aspects of the oxidation reaction remain unclear; experiments reveal clearly that electron stimulated oxidation drives the process yet it is not understood why H 2O purifies by a bottom-up mechanism while O 2 purifies frommore » the top-down. The simulation results presented here suggest that the chemisorption of dissolved O 2 at buried Pt nanoparticle surfaces controls purification in the top-down case while both the high relative solubility coupled with weak physisorption of H 2O explains the bottom-up process. Crucial too is the role that the carbonaceous contaminant itself has on the dissolution and diffusion of O 2 and H 2O. The results pave the way for simulation driven experiments where (1) the transient densification of the deposit can be accounted for in the initial deposit design stage and (2) the deposition and purification steps can be combined.« less

Brazilian version of the Functional Status Score for the ICU: translation and cross-cultural adaptation

PubMed Central

da Silva, Vinicius Zacarias Maldaner; de Araújo Neto, Jose Aires; Cipriano Jr., Gerson; Pinedo, Mariela; Needham, Dale M.; Zanni, Jennifer M.; Guimarães, Fernando Silva

2017-01-01

Objective The aim of the present study was to translate and cross-culturally adapt the Functional Status Score for the intensive care unit (FSS-ICU) into Brazilian Portuguese. Methods This study consisted of the following steps: translation (performed by two independent translators), synthesis of the initial translation, back-translation (by two independent translators who were unaware of the original FSS-ICU), and testing to evaluate the target audience's understanding. An Expert Committee supervised all steps and was responsible for the modifications made throughout the process and the final translated version. Results The testing phase included two experienced physiotherapists who assessed a total of 30 critical care patients (mean FSS-ICU score = 25 ± 6). As the physiotherapists did not report any uncertainties or problems with interpretation affecting their performance, no additional adjustments were made to the Brazilian Portuguese version after the testing phase. Good interobserver reliability between the two assessors was obtained for each of the 5 FSS-ICU tasks and for the total FSS-ICU score (intraclass correlation coefficients ranged from 0.88 to 0.91). Conclusion The adapted version of the FSS-ICU in Brazilian Portuguese was easy to understand and apply in an intensive care unit environment. PMID:28444070

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

Mays, Jeff

One-step hydrogen generation, using Sorption Enhanced Reforming (SER) technology, is an innovative means of providing critical energy and environmental improvements to US manufacturing processes. The Gas Technology Institute (GTI) is developing a Compact Hydrogen Generator (CHG) process, based on SER technology, which successfully integrates previously independent process steps, achieves superior energy efficiency by lowering reaction temperatures, and provides pathways to doubling energy productivity with less environmental pollution. GTI’s prior CHG process development efforts have culminated in an operational pilot plant. During the initial pilot testing, GTI identified two operating risks- 1) catalyst coating with calcium aluminate compounds, 2) limited solidsmore » handling of the sorbent. Under this contract GTI evaluated alternative materials (one catalyst and two sorbents) to mitigate both risks. The alternate catalyst met performance targets and did not experience coating with calcium aluminate compounds of any kind. The alternate sorbent materials demonstrated viable operation, with one material enabling a three-fold increase in sorbent flow. The testing also demonstrated operation at 90% of its rated capacity. Lastly, a carbon dioxide co-production study was performed to assess the advantage of the solid phase separation of carbon dioxide- inherent in the CHG process. Approximately 70% lower capital cost is achievable compared to SMR-based hydrogen production with CO2 capture, as well as improved operating costs.« less

Electron nanoprobe induced oxidation: A simulation of direct-write purification

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

Fowlkes, J. D.; Geier, B.; Lewis, B. B.

Electron beam direct-write has recently taken a large step forward with the advent of methods to purify deposits. This development has opened the door for future direct-write device prototyping and editing. In one such approach, an additional beam scanning procedure removes carbonaceous impurities via oxidation from metal–carbon deposits (e.g., PtC 5) in the presence of H 2O or O 2 after deposition. So far, critical aspects of the oxidation reaction remain unclear; experiments reveal clearly that electron stimulated oxidation drives the process yet it is not understood why H 2O purifies by a bottom-up mechanism while O 2 purifies frommore » the top-down. The simulation results presented here suggest that the chemisorption of dissolved O 2 at buried Pt nanoparticle surfaces controls purification in the top-down case while both the high relative solubility coupled with weak physisorption of H 2O explains the bottom-up process. Crucial too is the role that the carbonaceous contaminant itself has on the dissolution and diffusion of O 2 and H 2O. The results pave the way for simulation driven experiments where (1) the transient densification of the deposit can be accounted for in the initial deposit design stage and (2) the deposition and purification steps can be combined.« less

Improved quality-by-design compliant methodology for method development in reversed-phase liquid chromatography.

PubMed

Debrus, Benjamin; Guillarme, Davy; Rudaz, Serge

2013-10-01

A complete strategy dedicated to quality-by-design (QbD) compliant method development using design of experiments (DOE), multiple linear regressions responses modelling and Monte Carlo simulations for error propagation was evaluated for liquid chromatography (LC). The proposed approach includes four main steps: (i) the initial screening of column chemistry, mobile phase pH and organic modifier, (ii) the selectivity optimization through changes in gradient time and mobile phase temperature, (iii) the adaptation of column geometry to reach sufficient resolution, and (iv) the robust resolution optimization and identification of the method design space. This procedure was employed to obtain a complex chromatographic separation of 15 antipsychotic basic drugs, widely prescribed. To fully automate and expedite the QbD method development procedure, short columns packed with sub-2 μm particles were employed, together with a UHPLC system possessing columns and solvents selection valves. Through this example, the possibilities of the proposed QbD method development workflow were exposed and the different steps of the automated strategy were critically discussed. A baseline separation of the mixture of antipsychotic drugs was achieved with an analysis time of less than 15 min and the robustness of the method was demonstrated simultaneously with the method development phase. Copyright © 2013 Elsevier B.V. All rights reserved.

Doppler radar sensing of fish physiological motion

NASA Astrophysics Data System (ADS)

Hafner, Noah

The monitoring vital of signs for fish is critical for advancing the study of trophic and energetic strategies, distributions and behavior, environmental impact, and aquaculture approaches. Presented here is a new approach for monitoring fish metabolic state without the trauma and stress associated with capture, surgical ECG, or other implanted sensing systems. Original research contributions include analysis for radar operation under water, development of radar systems for aquatic operation, and application of these systems to non invasively sense the heart and gill motion of fish. Tilapia and Sturgeon were studied to test the efficacy across varied fish body shapes and sizes, ranging from 0.1 to 1.3m in snout to tail length. Monitoring experiments were conducted with eleven tilapia and three sturgeons to assess activity level participated in these experiments, the results from which include activity level monitoring (tilapia: still or fidgeting 94% of time observed), ventilation rate (tilapia: 42 bpm, sturgeon: 145 bpm), and heart rate (tilapia: 41 bpm, sturgeon: 35 bpm). Bland-Altman analysis of radar and ECG measured heart rate indicate agreement between the two measurement techniques and the suitability of radar as an alternative to ECG. The initial steps for developing a system for practical application is also presented including designs for radar system miniaturization and discussion on further characterization steps with less constrained environments.

Influence of prepreg characteristics on stamp consolidation

NASA Astrophysics Data System (ADS)

Slange, T. K.; Warnet, L. L.; Grouve, W. J. B.; Akkerman, R.

2017-10-01

Stamp forming is a rapid manufacturing technology used to shape flat blanks of thermoplastic composite material into three-dimensional components. The development of automated lay-up technologies further extends the applicability of stamp forming by allowing rapid lay-up of tailored blanks and partial preconsolidation. This partial preconsolidation makes the influence of prepreg more critical compared to conventional preconsolidation methods which provide full preconsolidation. This paper aims to highlight consolidation challenges that can appear when stamp forming blanks manufactured by automated lay-up. Important prepreg characteristics were identified based on an experimental study where a comparison was made between various prepreg in their as-received, deconsolidated and stamp consolidated state. It was found that adding up small thickness variations across the width of a prepreg when stacking plies into a blank by automated lay-up can cause non-uniform consolidation. Additionally, deconsolidation of the prepreg does not seem to obstruct interlaminar bonding, while intralaminar voids initially present in a prepreg cannot be removed during stamp forming. An additional preconsolidation step after automated lay-up seems necessary to remove blank thickness variations and intralaminar voids for the current prepregs. Eliminating this process step and the successful combination of rapid automated lay-up and stamp forming requires prepregs which are void-free and have less thickness variation.

Geometries for roughness shapes in laminar flow

NASA Technical Reports Server (NTRS)

Holmes, Bruce J. (Inventor); Martin, Glenn L. (Inventor); Domack, Christopher S. (Inventor); Obara, Clifford J. (Inventor); Hassan, Ahmed A. (Inventor)

1986-01-01

A passive interface mechanism between upper and lower skin structures, and a leading edge structure of a laminar flow airfoil is described. The interface mechanism takes many shapes. All are designed to be different than the sharp orthogonal arrangement prevalent in the prior art. The shapes of the interface structures are generally of two types: steps away from the centerline of the airfoil with a sloping surface directed toward the trailing edge and, the other design has a gap before the sloping surface. By properly shaping the step, the critical step height is increased by more than 50% over the orthogonal edged step.

Critical to quality in telemedicine service management: application of DFSS (Design for Six Sigma) and SERVQUAL).

PubMed

Yun, Eun Kyoung; Chun, Kee Moon

2008-01-01

Telemedicine generally refers to the use of communications and information technologies for the delivery of health care. owever, telemedicine is not merely a simple combination of health care and technology. The researchers propose a systematic approach for assessing needs of telemedicine customers, called critical-to-quality (CTQ) in Six Sigma, with a purpose of continuous quality improvement. The combination approach using DFSS (Design for Six Sigma) and SERVQUAL (Service Quality Framework) was applied to define the critical quality attributes of telemedicine service management and to match them with the current telemedicine process. With a step-by-step procedure, telemedicine service process was reviewed and all the important CTQ candidates identified via a case study. The findings suggest that nurses need further understanding and research methods that will improve and manage the quality of health care service in various medical fields.

Expansion of a quantum wave packet in a one-dimensional disordered potential in the presence of a uniform bias force

NASA Astrophysics Data System (ADS)

Crosnier de Bellaistre, C.; Trefzger, C.; Aspect, A.; Georges, A.; Sanchez-Palencia, L.

2018-01-01

We study numerically the expansion dynamics of an initially confined quantum wave packet in the presence of a disordered potential and a uniform bias force. For white-noise disorder, we find that the wave packet develops asymmetric algebraic tails for any ratio of the force to the disorder strength. The exponent of the algebraic tails decays smoothly with that ratio and no evidence of a critical behavior on the wave density profile is found. Algebraic localization features a series of critical values of the force-to-disorder strength where the m th position moment of the wave packet diverges. Below the critical value for the m th moment, we find fair agreement between the asymptotic long-time value of the m th moment and the predictions of diagrammatic calculations. Above it, we find that the m th moment grows algebraically in time. For correlated disorder, we find evidence of systematic delocalization, irrespective to the model of disorder. More precisely, we find a two-step dynamics, where both the center-of-mass position and the width of the wave packet show transient localization, similar to the white-noise case, at short time and delocalization at sufficiently long time. This correlation-induced delocalization is interpreted as due to the decrease of the effective de Broglie wavelength, which lowers the effective strength of the disorder in the presence of finite-range correlations.

Baby-Friendly Hospital Initiative: evaluation of the Ten Steps to Successful Breastfeeding

PubMed Central

Lopes, Soraia da Silva; Laignier, Mariana Rabello; Primo, Cândida Caniçali; Leite, Franciéle Marabotti C.

2013-01-01

OBJECTIVE: To asses the performance of the Ten Steps to Successful Breastfeeding in an university hospital. METHODS: Descriptive and quantitative research, in which 103 people were interviewed in the outpatient prenatal clinic, in the maternity-ward and in the Neonatal Intensive Care Unit of a university hospital in Vitória, Southeast Brazil. The "Institutional Self-Evaluation Questionnaire" of the Baby Friendly Hospital Initiative was applied. Using this tool, the outcome was measured by the concordance index (CI) proposed by the World Health Organization and by the United Nations Children's Fund. RESULTS: Although the hospital does not have a policy that addresses promotion, protection and support for breastfeeding, 93.3% of the mothers had contact with their babies immediately after birth (step 4), 83.3% of the professionals guided mothers how to breastfeed (step 5), 86.6% of the neonates did not receive any food or drink other than breast milk (step 6), 100% of babies were housed together with their mothers (step 7), 83.3% of the women were encouraged for breastfeeding on demand (step 8) and 100% of the infants did not use bottles or pacifiers (step 9). CONCLUSIONS: 60% of the steps were completed by the hospital. The greatest difficulty was to inform pregnant women about the importance and the management of breastfeeding (step 3). Therefore, visits to pregnant women are recommended, in order to prepare them for breastfeeding and to explain about the infants' healthy feeding habits. PMID:24473954

Folding and Boudinage As the Same Fundamental Energy Bifurcation in Elasto-Visco-Plastic Rocks

NASA Astrophysics Data System (ADS)

Peters, M.; Paesold, M.; Veveakis, M.; Poulet, T.; Herwegh, M.; Regenauer-Lieb, K.

2014-12-01

Folding or boudinage are commonly thought to develop due to viscosity contrasts induced by either geometric interactions or material imperfections. However, there exists an additional localization phenomenon, i.e. strain localization out of steady state in homogeneous materials at a critical material parameter (set) or deformation rate. This study focuses on imperfections in terms of grain size variations, using the paleowattmeter relationship [Austin and Evans, 2007; 2009, Herwegh et al., 2014]. We identify the parameters for bifurcation, which is the critical amount of dissipation, expressed by the Gruntfest number [Gruntfest, 1963], incorporating flow stress, the Arrhenius number (Q/RT) and the layer dimensions. We verify the robustness of the solution through a method, developed to analyze such material instabilities [Rudnicki and Rice, 1975]. The second step is to identify the natural mode shapes and frequencies of the geometric structure and material parameters, including geometric imperfections. In a third step, the eigenmodes are perturbed and superposed to the initial conditions. We then subject the composite structure to natural deformation conditions. Grain sizes within the layer relatively quickly equilibrate to a homogeneous state, which is in response to energy optimization following the paleowattmeterrelationship. Upon continued loading, localization in terms of a necking or folding instability consequently arises out of this steady state. We obtain the criteria for the onset of localization from theory and numerical simulation, i.e. the critical Gruntfest number. Boudinage and folding instabilities occur when heat produced by dissipative work overcomes the diffusive capacity of the system. Both instabilities develop for the exact same Arrhenius and Gruntfestnumbers. Consequently, folding and boudinage instabilities can be seen as the same energy bifurcation triggered by dissipative work out of homogeneous state. Austin, N.J. and Evans, B. (2007) Geology, 35Austin, N.J. and Evans, B. (2009) Journal of Geophysical Research, 114Gruntfest, I.J. (1963) Transactions of the Society of Rheology, 7Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (2014) Journal of Geophysical Research, 119Rudnicki, J.W. and Rice, J.R. (1975) Journal of Mechanics and Physics of Solids, 23

Molten salt reactor neutronics and fuel cycle modeling and simulation with SCALE

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

Betzler, Benjamin R.; Powers, Jeffrey J.; Worrall, Andrew

Current interest in advanced nuclear energy and molten salt reactor (MSR) concepts has enhanced interest in building the tools necessary to analyze these systems. A Python script known as ChemTriton has been developed to simulate equilibrium MSR fuel cycle performance by modeling the changing isotopic composition of an irradiated fuel salt using SCALE for neutron transport and depletion calculations. Some capabilities in ChemTriton that have improved, include a generic geometry capable of modeling multi-zone and multi-fluid systems, enhanced time-dependent feed and separations, and a critical concentration search. Although more generally applicable, the capabilities developed to date are illustrated in thismore » paper in three applied problems: (1) simulating the startup of a thorium-based MSR fuel cycle (a likely scenario requires the first of these MSRs to be started without available 233U); (2) determining the effect of the removal of different fission products on MSR operations; and (3) obtaining the equilibrium concentration of a mixed-oxide light-water reactor fuel in a two-stage fuel cycle with a sodium fast reactor. Moreover, the third problem is chosen to demonstrate versatility in an application to analyze the fuel cycle of a non-MSR system. During the first application, the initial fuel salt compositions fueled with different sources of fissile material are made feasible after (1) removing the associated nonfissile actinides after much of the initial fissile isotopes have burned and (2) optimizing the thorium concentration to maintain a critical configuration without significantly reducing breeding capability. In the second application, noble metal, volatile gas, and rare earth element fission products are shown to have a strong negative effect on criticality in a uranium-fueled thermal-spectrum MSR; their removal significantly increases core lifetime (by 30%) and fuel utilization. In the third application, the fuel of a mixed-oxide light-water reactor approaches an equilibrium composition after 20 depletion steps, demonstrating the potential for the longer time scales required to achieve equilibrium for solid-fueled systems over liquid fuel systems. This time to equilibrium can be reduced by starting with an initial fuel composition closer to that of the equilibrium fuel, reducing the need to handle time-dependent fuel compositions.« less