The Common Patterns of Nature

PubMed Central

Frank, Steven A.

2010-01-01

We typically observe large-scale outcomes that arise from the interactions of many hidden, small-scale processes. Examples include age of disease onset, rates of amino acid substitutions, and composition of ecological communities. The macroscopic patterns in each problem often vary around a characteristic shape that can be generated by neutral processes. A neutral generative model assumes that each microscopic process follows unbiased or random stochastic fluctuations: random connections of network nodes; amino acid substitutions with no effect on fitness; species that arise or disappear from communities randomly. These neutral generative models often match common patterns of nature. In this paper, I present the theoretical background by which we can understand why these neutral generative models are so successful. I show where the classic patterns come from, such as the Poisson pattern, the normal or Gaussian pattern, and many others. Each classic pattern was often discovered by a simple neutral generative model. The neutral patterns share a special characteristic: they describe the patterns of nature that follow from simple constraints on information. For example, any aggregation of processes that preserves information only about the mean and variance attracts to the Gaussian pattern; any aggregation that preserves information only about the mean attracts to the exponential pattern; any aggregation that preserves information only about the geometric mean attracts to the power law pattern. I present a simple and consistent informational framework of the common patterns of nature based on the method of maximum entropy. This framework shows that each neutral generative model is a special case that helps to discover a particular set of informational constraints; those informational constraints define a much wider domain of non-neutral generative processes that attract to the same neutral pattern. PMID:19538344

Study on the generation technology of Li brocade pattern mutant genes based on the AI and Java technology

NASA Astrophysics Data System (ADS)

Zhou, Yuping; Zhang, Qi

2018-04-01

In the information environment, digital and information processing to Li brocade patterns reveals an important means of Li ethnic style and inheriting the national culture. Adobe Illustrator CS3 and Java language were used in the paper to make "variation" processing to Li brocade patterns, and generate "Li brocade pattern mutant genes". The generation of pattern mutant genes includes color mutation, shape mutation, adding and missing transform, and twisted transform, etc. Research shows that Li brocade pattern mutant genes can be generated by using the Adobe Illustrator CS3 and the image processing tools of Java language edit, etc.

Generation 1.5 Written Error Patterns: A Comparative Study

ERIC Educational Resources Information Center

Doolan, Stephen M.; Miller, Donald

2012-01-01

In an attempt to contribute to existing research on Generation 1.5 students, the current study uses quantitative and qualitative methods to compare error patterns in a corpus of Generation 1.5, L1, and L2 community college student writing. This error analysis provides one important way to determine if error patterns in Generation 1.5 student…

Pattern self-repetition of fingerprints, lip prints, and palatal rugae among three generations of family: A forensic approach to identify family hierarchy.

PubMed

Mala, Sankeerti; Rathod, Vanita; Pundir, Siddharth; Dixit, Sudhanshu

2017-01-01

The unique pattern and structural diversity of fingerprints, lip prints, palatal rugae, and their occurrence in different patterns among individuals make it questionable whether they are completely unique even in a family hierarchy? Do they have any repetition of the patterns among the generations? Or is this a mere chaos theory? The present study aims to assess the pattern self-repetition of fingerprints, lip prints, and palatal rugae among three generations of ten different families. The present study was conducted at Rungta College of Dental Science and Research, Bhilai, India. Participants birth by origin of Chhattisgarh were only included in the study. Thirty participants from three consecutive generations of ten different families were briefed about the purpose of the study, and their fingerprints, lip prints, and palatal rugae impression were recorded and analyzed for the pattern of self-repetition. Multiple comparisons among the generations and one-way analysis of variance test were performed using SPSS 20 trial version. Among the pattern of primary palatal rugae, 10% showed repetition in all the three generations. Thirty percent showed repetition of the pattern of thumb fingerprints in all the three generation. The pattern of lip prints in the middle 1/3 rd of lower lip, 20% showed repetition in alternative generations. The evaluations of fingerprints, lip prints, and palatal rugae showed fractal dimensions, occurring variations in dimensions according to the complexity of each structure. Even though a minute self-repetition in the patterns of lip, thumb, and palate among the three consequent generations in a family was observed considering the sample size, these results need to be confirmed in a larger sample, either to establish the role of chaos theory in forensic science or identifying a particular pattern of the individual in his family hierarchy.

Caregiving Practice Patterns of Asian, Hispanic, and Non-Hispanic White American Family Caregivers of Older Adults Across Generations.

PubMed

Miyawaki, Christina E

2016-03-01

This study is a cross-sectional investigation of caregiving practice patterns among Asian, Hispanic and non-Hispanic White American family caregivers of older adults across three immigrant generations. The 2009 California Health Interview Survey (CHIS) dataset was used, and 591 Asian, 989 Hispanic and 6537 non-Hispanic White American caregivers of older adults were selected. First, descriptive analyses of caregivers' characteristics, caregiving situations and practice patterns were examined by racial/ethnic groups and immigrant generations. Practice patterns measured were respite care use, hours and length of caregiving. Three hypotheses on caregiving patterns based on assimilation theory were tested and analyzed using logistic regression and generalized linear models by racial/ethnic groups and generations. Caregiving patterns of non-Hispanic White caregivers supported all three hypotheses regarding respite care use, caregiving hours and caregiving duration, showing less caregiving involvement in later generations. However, Asian and Hispanic counterparts showed mixed results. Third generation Asian and Hispanic caregivers used respite care the least and spent the most caregiving hours per week and had the longest caregiving duration compared to earlier generations. These caregiving patterns revealed underlying cultural values related to filial responsibility, even among later generations of caregivers of color. Findings suggest the importance of considering the cultural values of each racial/ethnic group regardless of generation when working with racially and ethnically diverse populations of family caregivers of older adults.

Simple Process-Based Simulators for Generating Spatial Patterns of Habitat Loss and Fragmentation: A Review and Introduction to the G-RaFFe Model

PubMed Central

Pe'er, Guy; Zurita, Gustavo A.; Schober, Lucia; Bellocq, Maria I.; Strer, Maximilian; Müller, Michael; Pütz, Sandro

2013-01-01

Landscape simulators are widely applied in landscape ecology for generating landscape patterns. These models can be divided into two categories: pattern-based models that generate spatial patterns irrespective of the processes that shape them, and process-based models that attempt to generate patterns based on the processes that shape them. The latter often tend toward complexity in an attempt to obtain high predictive precision, but are rarely used for generic or theoretical purposes. Here we show that a simple process-based simulator can generate a variety of spatial patterns including realistic ones, typifying landscapes fragmented by anthropogenic activities. The model “G-RaFFe” generates roads and fields to reproduce the processes in which forests are converted into arable lands. For a selected level of habitat cover, three factors dominate its outcomes: the number of roads (accessibility), maximum field size (accounting for land ownership patterns), and maximum field disconnection (which enables field to be detached from roads). We compared the performance of G-RaFFe to three other models: Simmap (neutral model), Qrule (fractal-based) and Dinamica EGO (with 4 model versions differing in complexity). A PCA-based analysis indicated G-RaFFe and Dinamica version 4 (most complex) to perform best in matching realistic spatial patterns, but an alternative analysis which considers model variability identified G-RaFFe and Qrule as performing best. We also found model performance to be affected by habitat cover and the actual land-uses, the latter reflecting on land ownership patterns. We suggest that simple process-based generators such as G-RaFFe can be used to generate spatial patterns as templates for theoretical analyses, as well as for gaining better understanding of the relation between spatial processes and patterns. We suggest caution in applying neutral or fractal-based approaches, since spatial patterns that typify anthropogenic landscapes are often non-fractal in nature. PMID:23724108

Simple process-based simulators for generating spatial patterns of habitat loss and fragmentation: a review and introduction to the G-RaFFe model.

PubMed

Pe'er, Guy; Zurita, Gustavo A; Schober, Lucia; Bellocq, Maria I; Strer, Maximilian; Müller, Michael; Pütz, Sandro

2013-01-01

Landscape simulators are widely applied in landscape ecology for generating landscape patterns. These models can be divided into two categories: pattern-based models that generate spatial patterns irrespective of the processes that shape them, and process-based models that attempt to generate patterns based on the processes that shape them. The latter often tend toward complexity in an attempt to obtain high predictive precision, but are rarely used for generic or theoretical purposes. Here we show that a simple process-based simulator can generate a variety of spatial patterns including realistic ones, typifying landscapes fragmented by anthropogenic activities. The model "G-RaFFe" generates roads and fields to reproduce the processes in which forests are converted into arable lands. For a selected level of habitat cover, three factors dominate its outcomes: the number of roads (accessibility), maximum field size (accounting for land ownership patterns), and maximum field disconnection (which enables field to be detached from roads). We compared the performance of G-RaFFe to three other models: Simmap (neutral model), Qrule (fractal-based) and Dinamica EGO (with 4 model versions differing in complexity). A PCA-based analysis indicated G-RaFFe and Dinamica version 4 (most complex) to perform best in matching realistic spatial patterns, but an alternative analysis which considers model variability identified G-RaFFe and Qrule as performing best. We also found model performance to be affected by habitat cover and the actual land-uses, the latter reflecting on land ownership patterns. We suggest that simple process-based generators such as G-RaFFe can be used to generate spatial patterns as templates for theoretical analyses, as well as for gaining better understanding of the relation between spatial processes and patterns. We suggest caution in applying neutral or fractal-based approaches, since spatial patterns that typify anthropogenic landscapes are often non-fractal in nature.

Maskless micro-ion-beam reduction lithography system

DOEpatents

Leung, Ka-Ngo; Barletta, William A.; Patterson, David O.; Gough, Richard A.

2005-05-03

A maskless micro-ion-beam reduction lithography system is a system for projecting patterns onto a resist layer on a wafer with feature size down to below 100 nm. The MMRL system operates without a stencil mask. The patterns are generated by switching beamlets on and off from a two electrode blanking system or pattern generator. The pattern generator controllably extracts the beamlet pattern from an ion source and is followed by a beam reduction and acceleration column.

Design space exploration for early identification of yield limiting patterns

NASA Astrophysics Data System (ADS)

Li, Helen; Zou, Elain; Lee, Robben; Hong, Sid; Liu, Square; Wang, JinYan; Du, Chunshan; Zhang, Recco; Madkour, Kareem; Ali, Hussein; Hsu, Danny; Kabeel, Aliaa; ElManhawy, Wael; Kwan, Joe

2016-03-01

In order to resolve the causality dilemma of which comes first, accurate design rules or real designs, this paper presents a flow for exploration of the layout design space to early identify problematic patterns that will negatively affect the yield. A new random layout generating method called Layout Schema Generator (LSG) is reported in this paper, this method generates realistic design-like layouts without any design rule violation. Lithography simulation is then used on the generated layout to discover the potentially problematic patterns (hotspots). These hotspot patterns are further explored by randomly inducing feature and context variations to these identified hotspots through a flow called Hotspot variation Flow (HSV). Simulation is then performed on these expanded set of layout clips to further identify more problematic patterns. These patterns are then classified into design forbidden patterns that should be included in the design rule checker and legal patterns that need better handling in the RET recipes and processes.

Development of biomass in a drinking water granular active carbon (GAC) filter.

PubMed

Velten, Silvana; Boller, Markus; Köster, Oliver; Helbing, Jakob; Weilenmann, Hans-Ulrich; Hammes, Frederik

2011-12-01

Indigenous bacteria are essential for the performance of drinking water biofilters, yet this biological component remains poorly characterized. In the present study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the first six months of operation. GAC particles were sampled from four different depths (10, 45, 80 and 115 cm) and attached biomass was measured with adenosine tri-phosphate (ATP) analysis. The attached biomass accumulated rapidly on the GAC particles throughout all levels in the filter during the first 90 days of operation and maintained a steady state afterward. Vertical gradients of biomass density and growth rates were observed during start-up and also in steady state. During steady state, biomass concentrations ranged between 0.8-1.83 x 10(-6) g ATP/g GAC in the filter, and 22% of the influent dissolved organic carbon (DOC) was removed. Concomitant biomass production was about 1.8 × 10(12) cells/m(2)h, which represents a yield of 1.26 × 10(6) cells/μg. The bacteria assimilated only about 3% of the removed carbon as biomass. At one point during the operational period, a natural 5-fold increase in the influent phytoplankton concentration occurred. As a result, influent assimilable organic carbon concentrations increased and suspended bacteria in the filter effluent increased 3-fold as the direct consequence of increased growth in the biofilter. This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilters. Copyright © 2011 Elsevier Ltd. All rights reserved.

Rejuvenation capacity of red blood cells in additive solutions over long-term storage.

PubMed

Meyer, Erin K; Dumont, Deborah F; Baker, Sharry; Dumont, Larry J

2011-07-01

Red blood cells (RBCs) are Food and Drug Administration (FDA)-approved for 42-day storage with the use of additive solutions (ASs). However, adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) levels in the RBCs decline over this time. These constituents may be restored by treatment with rejuvenation (REJ) solutions. This study was done to assess the response capability of RBCs from 30 to 120 days of storage in three FDA-licensed RBC storage solutions after incubation with a rejuvenating solution of pyruvate, inosine, phosphate, and adenine. Three units each of RBCs in approved AS (AS-1 [Adsol, Fenwal, Inc.], AS-3 [Nutricel, Medsep Corp.], and AS-5 [Optisol, Terumo Corp.]) were stored under standard conditions at 1 to 6°C for up to 120 days. Aliquots (4 mL) on Days 30, 42, 60, 80, 100, and 120 (± 2 days) were REJ by incubating with Rejuvesol (Encyte Corp.). Control untreated and REJ aliquots were extracted using perchloric acid and stored at -80°C until assayed for 2,3-DPG and ATP. RBCs responded to REJ by increasing DPG and ATP contents. The response declined linearly at 0.070 ± 0.008 µmol DPG/g hemoglobin (Hb)/day and 0.035 ± 0.004 µmol ATP/g Hb/day with no differences between ASs. We conclude that Rejuvesol is able to restore ATP and 2,3-DPG levels in RBCs stored up to 120 days in AS. The response diminishes as storage time increases. This rejuvenation (REJ) capability does not seem useful for routine assessment of RBC anabolic capacity in research programs, but may be useful to the investigator when studying unique and novel treatment methods. © 2011 American Association of Blood Banks.

Automatic Generation of English-Japanese Translation Pattern Utilizing Genetic Programming Technique

NASA Astrophysics Data System (ADS)

Matsumura, Koki; Tamekuni, Yuji; Kimura, Shuhei

There are a lot of constructional differences in an English-Japanese phrase template, and that often makes the act of translation difficult. Moreover, there exist various and tremendous phrase templates and sentence to be refered to. It is not easy to prepare the corpus that covers the all. Therefore, it is very significant to generate the translation pattern of the sentence pattern automatically from a viewpoint of the translation success rate and the capacity of the pattern dictionary. Then, for the purpose of realizing the automatic generation of the translation pattern, this paper proposed the new method for the generation of the translation pattern by using the genetic programming technique (GP). The technique tries to generate the translation pattern of various sentences which are not registered in the phrase template dictionary automatically by giving the genetic operation to the parsing tree of a basic pattern. The tree consists of the pair of the English-Japanese sentence generated as the first stage population. The analysis tree data base with 50,100,150,200 pairs was prepared as the first stage population. And this system was applied and executed for an English input of 1,555 sentences. As a result, the analysis tree increases from 200 to 517, and the accuracy rate of the translation pattern has improved from 42.57% to 70.10%. And, 86.71% of the generated translations was successfully done, whose meanings are enough acceptable and understandable. It seemed that this proposal technique became a clue to raise the translation success rate, and to find the possibility of the reduction of the analysis tree data base.

On the role of the reticular formation in vocal pattern generation.

PubMed

Jürgens, Uwe; Hage, Steffen R

2007-09-04

This review is an attempt to localize the brain region responsible for pattern generation of species-specific vocalizations. A catalogue is set up, listing the criteria considered to be essential for a vocal pattern generator. According to this catalogue, a vocal pattern generator should show vocalization-correlated activity, starting before vocal onset and reflecting specific acoustic features of the vocalization. Artificial activation by electrical or glutamatergic stimulation should produce artificially sounding vocalization. Lesioning is expected to have an inhibitory or deteriorating effect on vocalization. Anatomically, a vocal pattern generator can be assumed to have direct or, at least, oligosynaptic connections with all the motoneuron pools involved in phonation. A survey of the literature reveals that the only area meeting all these criteria is a region, reaching from the parvocellular pontine reticular formation just above the superior olive through the lateral reticular formation around the facial nucleus and nucleus ambiguus down to the caudalmost medulla, including the dorsal and ventral reticular nuclei and nucleus retroambiguus. It is proposed that vocal pattern generation takes place within this whole region.

Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography

PubMed Central

He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

2016-01-01

With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment. PMID:26902520

Identification of nuclear weapons

DOEpatents

Mihalczo, J.T.; King, W.T.

1987-04-10

A method and apparatus for non-invasively indentifying different types of nuclear weapons is disclosed. A neutron generator is placed against the weapon to generate a stream of neutrons causing fissioning within the weapon. A first detects the generation of the neutrons and produces a signal indicative thereof. A second particle detector located on the opposite side of the weapon detects the fission particles and produces signals indicative thereof. The signals are converted into a detected pattern and a computer compares the detected pattern with known patterns of weapons and indicates which known weapon has a substantially similar pattern. Either a time distribution pattern or noise analysis pattern, or both, is used. Gamma-neutron discrimination and a third particle detector for fission particles adjacent the second particle detector are preferably used. The neutrons are generated by either a decay neutron source or a pulled neutron particle accelerator.

Generation of shape complexity through tissue conflict resolution

PubMed Central

Rebocho, Alexandra B; Southam, Paul; Kennaway, J Richard; Coen, Enrico

2017-01-01

Out-of-plane tissue deformations are key morphogenetic events during plant and animal development that generate 3D shapes, such as flowers or limbs. However, the mechanisms by which spatiotemporal patterns of gene expression modify cellular behaviours to generate such deformations remain to be established. We use the Snapdragon flower as a model system to address this problem. Combining cellular analysis with tissue-level modelling, we show that an orthogonal pattern of growth orientations plays a key role in generating out-of-plane deformations. This growth pattern is most likely oriented by a polarity field, highlighted by PIN1 protein localisation, and is modulated by dorsoventral gene activity. The orthogonal growth pattern interacts with other patterns of differential growth to create tissue conflicts that shape the flower. Similar shape changes can be generated by contraction as well as growth, suggesting tissue conflict resolution provides a flexible morphogenetic mechanism for generating shape diversity in plants and animals. DOI: http://dx.doi.org/10.7554/eLife.20156.001 PMID:28166865

The New England travel market: generational travel patterns, 1979 to 1996

Treesearch

Rod Warnick

2002-01-01

Generations of travelers who select New England as a primary destination are examined over time from the years of 1979 through 1996 and the analysis serves to update an earlier review of generational travel patterns of the region (Warnick, 1994). Changes in travel patterns are noted by overall adjusted annual change rates by demographic and geographic regions of...

Expedient generation of patterned surface aldehydes by microfluidic oxidation for chemoselective immobilization of ligands and cells.

PubMed

Westcott, Nathan P; Pulsipher, Abigail; Lamb, Brian M; Yousaf, Muhammad N

2008-09-02

An expedient and inexpensive method to generate patterned aldehydes on self-assembled monolayers (SAMs) of alkanethiolates on gold with control of density for subsequent chemoselective immobilization from commercially available starting materials has been developed. Utilizing microfluidic cassettes, primary alcohol oxidation of tetra(ethylene glycol) undecane thiol and 11-mercapto-1-undecanol SAMs was performed directly on the surface generating patterned aldehyde groups with pyridinium chlorochromate. The precise density of surface aldehydes generated can be controlled and characterized by electrochemistry. For biological applications, fibroblast cells were seeded on patterned surfaces presenting biospecifc cell adhesive (Arg-Glyc-Asp) RGD peptides.

Automated branching pattern report generation for laparoscopic surgery assistance

NASA Astrophysics Data System (ADS)

Oda, Masahiro; Matsuzaki, Tetsuro; Hayashi, Yuichiro; Kitasaka, Takayuki; Misawa, Kazunari; Mori, Kensaku

2015-05-01

This paper presents a method for generating branching pattern reports of abdominal blood vessels for laparoscopic gastrectomy. In gastrectomy, it is very important to understand branching structure of abdominal arteries and veins, which feed and drain specific abdominal organs including the stomach, the liver and the pancreas. In the real clinical stage, a surgeon creates a diagnostic report of the patient anatomy. This report summarizes the branching patterns of the blood vessels related to the stomach. The surgeon decides actual operative procedure. This paper shows an automated method to generate a branching pattern report for abdominal blood vessels based on automated anatomical labeling. The report contains 3D rendering showing important blood vessels and descriptions of branching patterns of each vessel. We have applied this method for fifty cases of 3D abdominal CT scans and confirmed the proposed method can automatically generate branching pattern reports of abdominal arteries.

Laser induced Erasable Patterns in a N* Liquid Crystal on an Iron Doped Lithium Niobate (Postprint)

DTIC Science & Technology

2017-10-12

be applied selectively to erase these patterns. Thus, a promising method is reported to generate reconfigurable patterns, photonic motives , and...erase these patterns. Thus, a promising method is reported to generate reconfigurable patterns, photonic motives , and touch sensitive devices in a...release (PA): distribution unlimited. loss of the patterns inscribed. Possible motives are not limited to graphics. It should be also possible to write

Patterning roadmap: 2017 prospects

NASA Astrophysics Data System (ADS)

Neisser, Mark

2017-06-01

Road mapping of semiconductor chips has been underway for over 20 years, first with the International Technology Roadmap for Semiconductors (ITRS) roadmap and now with the International Roadmap for Devices and Systems (IRDS) roadmap. The original roadmap was mostly driven bottom up and was developed to ensure that the large numbers of semiconductor producers and suppliers had good information to base their research and development on. The current roadmap is generated more top-down, where the customers of semiconductor chips anticipate what will be needed in the future and the roadmap projects what will be needed to fulfill that demand. The More Moore section of the roadmap projects that advanced logic will drive higher-resolution patterning, rather than memory chips. Potential solutions for patterning future logic nodes can be derived as extensions of `next-generation' patterning technologies currently under development. Advanced patterning has made great progress, and two `next-generation' patterning technologies, EUV and nanoimprint lithography, have potential to be in production as early as 2018. The potential adoption of two different next-generation patterning technologies suggests that patterning technology is becoming more specialized. This is good for the industry in that it lowers overall costs, but may lead to slower progress in extending any one patterning technology in the future.

Direct generation of abruptly focusing vortex beams using a 3/2 radial phase-only pattern.

PubMed

Davis, Jeffrey A; Cottrell, Don M; Zinn, Jonathan M

2013-03-20

Abruptly focusing Airy beams have previously been generated using a radial cubic phase pattern that represents the Fourier transform of the Airy beam. The Fourier transform of this pattern is formed using a system length of 2f, where f is the focal length of the Fourier transform lens. In this work, we directly generate these abruptly focusing Airy beams using a 3/2 radial phase pattern encoded onto a liquid crystal display. The resulting optical system is much shorter. In addition, we can easily produce vortex patterns at the focal point of these beams. Experimental results match theoretical predictions.

Test pattern generation for ILA sequential circuits

NASA Technical Reports Server (NTRS)

Feng, YU; Frenzel, James F.; Maki, Gary K.

1993-01-01

An efficient method of generating test patterns for sequential machines implemented using one-dimensional, unilateral, iterative logic arrays (ILA's) of BTS pass transistor networks is presented. Based on a transistor level fault model, the method affords a unique opportunity for real-time fault detection with improved fault coverage. The resulting test sets are shown to be equivalent to those obtained using conventional gate level models, thus eliminating the need for additional test patterns. The proposed method advances the simplicity and ease of the test pattern generation for a special class of sequential circuitry.

Self-Assembly of Human Serum Albumin: A Simplex Phenomenon

PubMed Central

Thakur, Garima; Prashanthi, Kovur; Jiang, Keren; Thundat, Thomas

2017-01-01

Spontaneous self-assemblies of biomolecules can generate geometrical patterns. Our findings provide an insight into the mechanism of self-assembled ring pattern generation by human serum albumin (HSA). The self-assembly is a process guided by kinetic and thermodynamic parameters. The generated protein ring patterns display a behavior which is geometrically related to a n-simplex model and is explained through thermodynamics and chemical kinetics. PMID:28930179

The heparanome--the enigma of encoding and decoding heparan sulfate sulfation.

PubMed

Lamanna, William C; Kalus, Ina; Padva, Michael; Baldwin, Rebecca J; Merry, Catherine L R; Dierks, Thomas

2007-04-30

Heparan sulfate (HS) is a cell surface carbohydrate polymer modified with sulfate moieties whose highly ordered composition is central to directing specific cell signaling events. The ability of the cell to generate these information rich glycans with such specificity has opened up a new field of "heparanomics" which seeks to understand the systems involved in generating these cell type and developmental stage specific HS sulfation patterns. Unlike other instances where biological information is encrypted as linear sequences in molecules such as DNA, HS sulfation patterns are generated through a non-template driven process. Thus, deciphering the sulfation code and the dynamic nature of its generation has posed a new challenge to system biologists. The recent discovery of two sulfatases, Sulf1 and Sulf2, with the unique ability to edit sulfation patterns at the cell surface, has opened up a new dimension as to how we understand the regulation of HS sulfation patterning and pattern-dependent cell signaling events. This review will focus on the functional relationship between HS sulfation patterning and biological processes. Special attention will be given to Sulf1 and Sulf2 and how these key editing enzymes might act in concert with the HS biosynthetic enzymes to generate and regulate specific HS sulfation patterns in vivo. We will further explore the use of knock out mice as biological models for understanding the dynamic systems involved in generating HS sulfation patterns and their biological relevance. A brief overview of new technologies and innovations summarizes advances in the systems biology field for understanding non-template molecular networks and their influence on the "heparanome".

The New England travel market: changes in generational travel patterns

Treesearch

Rodney B. Warnick

1995-01-01

The purpose of this study was to examine and explore the New England domestic travel market trends, from 1979 through 1991 within the context of generations. The existing travel markets, who travel to New England, are changing by age cohorts and specifically within different generations. The New England changes in generational travel patterns do not reflect national...

Generation of 3D templates of active sites of proteins with rigid prosthetic groups.

PubMed

Nebel, Jean-Christophe

2006-05-15

With the increasing availability of protein structures, the generation of biologically meaningful 3D patterns from the simultaneous alignment of several protein structures is an exciting prospect: active sites could be better understood, protein functions and protein 3D structures could be predicted more accurately. Although patterns can already be generated at the fold and topological levels, no system produces high-resolution 3D patterns including atom and cavity positions. To address this challenge, our research focuses on generating patterns from proteins with rigid prosthetic groups. Since these groups are key elements of protein active sites, the generated 3D patterns are expected to be biologically meaningful. In this paper, we present a new approach which allows the generation of 3D patterns from proteins with rigid prosthetic groups. Using 237 protein chains representing proteins containing porphyrin rings, our method was validated by comparing 3D templates generated from homologues with the 3D structure of the proteins they model. Atom positions were predicted reliably: 93% of them had an accuracy of 1.00 A or less. Moreover, similar results were obtained regarding chemical group and cavity positions. Results also suggested our system could contribute to the validation of 3D protein models. Finally, a 3D template was generated for the active site of human cytochrome P450 CYP17, the 3D structure of which is unknown. Its analysis showed that it is biologically meaningful: our method detected the main patterns of the cytochrome P450 superfamily and the motifs linked to catalytic reactions. The 3D template also suggested the position of a residue, which could be involved in a hydrogen bond with CYP17 substrates and the shape and location of a cavity. Comparisons with independently generated 3D models comforted these hypotheses. Alignment software (Nestor3D) is available at http://www.kingston.ac.uk/~ku33185/Nestor3D.html

Effects of traffic generation patterns on the robustness of complex networks

NASA Astrophysics Data System (ADS)

Wu, Jiajing; Zeng, Junwen; Chen, Zhenhao; Tse, Chi K.; Chen, Bokui

2018-02-01

Cascading failures in communication networks with heterogeneous node functions are studied in this paper. In such networks, the traffic dynamics are highly dependent on the traffic generation patterns which are in turn determined by the locations of the hosts. The data-packet traffic model is applied to Barabási-Albert scale-free networks to study the cascading failures in such networks and to explore the effects of traffic generation patterns on network robustness. It is found that placing the hosts at high-degree nodes in a network can make the network more robust against both intentional attacks and random failures. It is also shown that the traffic generation pattern plays an important role in network design.

Human spinal locomotor control is based on flexibly organized burst generators.

PubMed

Danner, Simon M; Hofstoetter, Ursula S; Freundl, Brigitta; Binder, Heinrich; Mayr, Winfried; Rattay, Frank; Minassian, Karen

2015-03-01

Constant drive provided to the human lumbar spinal cord by epidural electrical stimulation can cause local neural circuits to generate rhythmic motor outputs to lower limb muscles in people paralysed by spinal cord injury. Epidural spinal cord stimulation thus allows the study of spinal rhythm and pattern generating circuits without their configuration by volitional motor tasks or task-specific peripheral feedback. To reveal spinal locomotor control principles, we studied the repertoire of rhythmic patterns that can be generated by the functionally isolated human lumbar spinal cord, detected as electromyographic activity from the legs, and investigated basic temporal components shared across these patterns. Ten subjects with chronic, motor-complete spinal cord injury were studied. Surface electromyographic responses to lumbar spinal cord stimulation were collected from quadriceps, hamstrings, tibialis anterior, and triceps surae in the supine position. From these data, 10-s segments of rhythmic activity present in the four muscle groups of one limb were extracted. Such samples were found in seven subjects. Physiologically adequate cycle durations and relative extension- and flexion-phase durations similar to those needed for locomotion were generated. The multi-muscle activation patterns exhibited a variety of coactivation, mixed-synergy and locomotor-like configurations. Statistical decomposition of the electromyographic data across subjects, muscles and samples of rhythmic patterns identified three common temporal components, i.e. basic or shared activation patterns. Two of these basic patterns controlled muscles to contract either synchronously or alternatingly during extension- and flexion-like phases. The third basic pattern contributed to the observed muscle activities independently from these extensor- and flexor-related basic patterns. Each bifunctional muscle group was able to express both extensor- and flexor-patterns, with variable ratios across the samples of rhythmic patterns. The basic activation patterns can be interpreted as central drives implemented by spinal burst generators that impose specific spatiotemporally organized activation on the lumbosacral motor neuron pools. Our data thus imply that the human lumbar spinal cord circuits can form burst-generating elements that flexibly combine to obtain a wide range of locomotor outputs from a constant, repetitive input. It may be possible to use this flexibility to incorporate specific adaptations to gait and stance to improve locomotor control, even after severe central nervous system damage. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Human spinal locomotor control is based on flexibly organized burst generators

PubMed Central

Danner, Simon M.; Hofstoetter, Ursula S.; Freundl, Brigitta; Binder, Heinrich; Mayr, Winfried; Rattay, Frank

2015-01-01

Constant drive provided to the human lumbar spinal cord by epidural electrical stimulation can cause local neural circuits to generate rhythmic motor outputs to lower limb muscles in people paralysed by spinal cord injury. Epidural spinal cord stimulation thus allows the study of spinal rhythm and pattern generating circuits without their configuration by volitional motor tasks or task-specific peripheral feedback. To reveal spinal locomotor control principles, we studied the repertoire of rhythmic patterns that can be generated by the functionally isolated human lumbar spinal cord, detected as electromyographic activity from the legs, and investigated basic temporal components shared across these patterns. Ten subjects with chronic, motor-complete spinal cord injury were studied. Surface electromyographic responses to lumbar spinal cord stimulation were collected from quadriceps, hamstrings, tibialis anterior, and triceps surae in the supine position. From these data, 10-s segments of rhythmic activity present in the four muscle groups of one limb were extracted. Such samples were found in seven subjects. Physiologically adequate cycle durations and relative extension- and flexion-phase durations similar to those needed for locomotion were generated. The multi-muscle activation patterns exhibited a variety of coactivation, mixed-synergy and locomotor-like configurations. Statistical decomposition of the electromyographic data across subjects, muscles and samples of rhythmic patterns identified three common temporal components, i.e. basic or shared activation patterns. Two of these basic patterns controlled muscles to contract either synchronously or alternatingly during extension- and flexion-like phases. The third basic pattern contributed to the observed muscle activities independently from these extensor- and flexor-related basic patterns. Each bifunctional muscle group was able to express both extensor- and flexor-patterns, with variable ratios across the samples of rhythmic patterns. The basic activation patterns can be interpreted as central drives implemented by spinal burst generators that impose specific spatiotemporally organized activation on the lumbosacral motor neuron pools. Our data thus imply that the human lumbar spinal cord circuits can form burst-generating elements that flexibly combine to obtain a wide range of locomotor outputs from a constant, repetitive input. It may be possible to use this flexibility to incorporate specific adaptations to gait and stance to improve locomotor control, even after severe central nervous system damage. PMID:25582580

Initial benchmarking of a new electron-beam raster pattern generator for 130-100 nm maskmaking

NASA Astrophysics Data System (ADS)

Sauer, Charles A.; Abboud, Frank E.; Babin, Sergey V.; Chakarian, Varoujan; Ghanbari, Abe; Innes, Robert; Trost, David; Raymond, Frederick, III

2000-07-01

The decision by the Semiconductor Industry Association (SIA) to accelerate the continuing evolution to smaller linewidths is consistent with the commitment by Etec Systems, Inc. to rapidly develop new technologies for pattern generation systems with improved resolution, critical dimension (CD) uniformity, positional accuracy, and throughput. Current pattern generation designs are inadequate to meet the more advanced requirements for masks, particularly at or below the 100 nm node. Major changes to all pattern generation tools will be essential to meet future market requirements. An electron-beam (e-beam) system that is designed to meet the challenges for 130 - 100 nm device generation with extendibility to the 70-nm range will be discussed. This system has an architecture that includes a graybeam writing strategy, a new state system, and improved thermal management. Detailed changes include a pulse width modulated blanking system, per-pixel deflection, retrograde scanning multipass writing, and a column with a 50 kV accelerating voltage that supports a dose of up to 45 (mu) C/cm2 with minimal amounts of resist heating. This paper examines current issues, our approach to meeting International Technology Roadmap for Semiconductors (ITRS) requirements, and some preliminary results from a new pattern generator.

Geographic migration of black and white families over four generations.

PubMed

Sharkey, Patrick

2015-02-01

This article analyzes patterns of geographic migration of black and white American families over four consecutive generations. The analysis is based on a unique set of questions in the Panel Study of Income Dynamics (PSID) asking respondents about the counties and states in which their parents and grandparents were raised. Using this information along with the extensive geographic information available in the PSID survey, the article tracks the geographic locations of four generations of family members and considers the ways in which families and places are linked together over the course of a family's history. The patterns documented in the article are consistent with much of the demographic literature on the Great Migration of black Americans out of the South, but they reveal new insights into patterns of black migration after the Great Migration. In the most recent generation, black Americans have remained in place to a degree that is unique relative to the previous generation and relative to whites of the same generation. This new geographic immobility is the most pronounced change in black Americans' migration patterns after the Great Migration, and it is a pattern that has implications for the demography of black migration as well as the literature on racial inequality.

Automatic two- and three-dimensional mesh generation based on fuzzy knowledge processing

NASA Astrophysics Data System (ADS)

Yagawa, G.; Yoshimura, S.; Soneda, N.; Nakao, K.

1992-09-01

This paper describes the development of a novel automatic FEM mesh generation algorithm based on the fuzzy knowledge processing technique. A number of local nodal patterns are stored in a nodal pattern database of the mesh generation system. These nodal patterns are determined a priori based on certain theories or past experience of experts of FEM analyses. For example, such human experts can determine certain nodal patterns suitable for stress concentration analyses of cracks, corners, holes and so on. Each nodal pattern possesses a membership function and a procedure of node placement according to this function. In the cases of the nodal patterns for stress concentration regions, the membership function which is utilized in the fuzzy knowledge processing has two meanings, i.e. the “closeness” of nodal location to each stress concentration field as well as “nodal density”. This is attributed to the fact that a denser nodal pattern is required near a stress concentration field. What a user has to do in a practical mesh generation process are to choose several local nodal patterns properly and to designate the maximum nodal density of each pattern. After those simple operations by the user, the system places the chosen nodal patterns automatically in an analysis domain and on its boundary, and connects them smoothly by the fuzzy knowledge processing technique. Then triangular or tetrahedral elements are generated by means of the advancing front method. The key issue of the present algorithm is an easy control of complex two- or three-dimensional nodal density distribution by means of the fuzzy knowledge processing technique. To demonstrate fundamental performances of the present algorithm, a prototype system was constructed with one of object-oriented languages, Smalltalk-80 on a 32-bit microcomputer, Macintosh II. The mesh generation of several two- and three-dimensional domains with cracks, holes and junctions was presented as examples.

ROLE OF NMDA, NICOTINIC, AND GABA RECEPTORS IN THE STEADY STATE VISUAL EVOKED POTENTIAL IN RATS.

EPA Science Inventory

This manuscript characterizes the receptor pathways involved in pattern-evoked potential generation in rats

" NMDA and nicotinic acetylcholine receptors appear to be involved in the generation of the steady-state pattern evoked response in vivo.

" The pattern evok...

Breathing simulator of workers for respirator performance test.

PubMed

Yuasa, Hisashi; Kumita, Mikio; Honda, Takeshi; Kimura, Kazushi; Nozaki, Kosuke; Emi, Hitoshi; Otani, Yoshio

2015-01-01

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.

Model-based guiding pattern synthesis for robust assembly of contact layers using directed self-assembly

NASA Astrophysics Data System (ADS)

Mitra, Joydeep; Torres, Andres; Ma, Yuansheng; Pan, David Z.

2018-01-01

Directed self-assembly (DSA) has emerged as one of the most compelling next-generation patterning techniques for sub 7 nm via or contact layers. A key issue in enabling DSA as a mainstream patterning technique is the generation of grapho-epitaxy-based guiding pattern (GP) shapes to assemble the contact patterns on target with high fidelity and resolution. Current GP generation is mostly empirical, and limited to a very small number of via configurations. We propose the first model-based GP synthesis algorithm and methodology for on-target and robust DSA, on general via pattern configurations. The final postoptical proximity correction-printed GPs derived from our original synthesized GPs are resilient to process variations and continue to maintain the same DSA fidelity in terms of placement error and target shape.

Controlling flows in microchannels with patterned surface charge and topography.

PubMed

Stroock, Abraham D; Whitesides, George M

2003-08-01

This Account reviews two procedures for controlling the flow of fluids in microchannels. The first procedure involves patterning the density of charge on the inner surfaces of a channel. These patterns generate recirculating electroosmotic flows in the presence of a steady electric field. The second procedure involves patterning topography on an inner surface of a channel. These patterns generate recirculation in the cross-section of steady, pressure-driven flows. This Account summarizes applications of these flow to mixing and to controlling dispersion (band broadening).

Assessment of CLIGEN precipitation and storm pattern generation under four precipitation depth categories in China

USDA-ARS?s Scientific Manuscript database

CLIGEN (CLImate GENerator) is a widely used stochastic weather generator to simulate continuous daily precipitation and storm pattern information for hydrological and soil erosion models. Although CLIGEN has been tested in several regions in the world, thoroughly assessment before applying it to Chi...

Central Pattern Generation and the Motor Infrastructure for Suck, Respiration, and Speech

ERIC Educational Resources Information Center

Barlow, Steven M.; Estep, Meredith

2006-01-01

The objective of the current report is to review experimental findings on centrally patterned movements and sensory and descending modulation of central pattern generators (CPGs) in a variety of animal and human models. Special emphasis is directed toward speech production muscle systems, including the chest wall and orofacial complex during…

Sex-biased phoretic mite load on two seaweed flies: Coelopa frigida and Coelopa pilipes.

PubMed

Gilburn, Andre S; Stewart, Katie M; Edward, Dominic A

2009-12-01

Two hypotheses explain male-biased parasitism. Physiological costs of male sexually selected characteristics can reduce immunocompetence. Alternatively, ecological differences could generate male-biased parasitism. One method of comparing the importance of the two theories is to investigate patterns of phoresy, which are only likely to be generated by ecological rather than immunological differences between the sexes. Here we studied the pattern of phoresy of the mite, Thinoseius fucicola, on two species of seaweed fly hosts, Coelopa frigida and Coelopa pilipes. We found a highly male-biased pattern of phoresy of T. fucicola on both species. These are the first reported instances of sex-biased phoresy in a solely phoretic parasite. We also show the first two cases of size-biased phoresy. We suggest that ecological factors, particularly, male mate searching, generated male biased patterns of phoresy. We highlight the potential importance of studies of phoresy in determining the relative roles of the immunocompetence and ecological theories in generating male-biased parasitism. We suggest that more studies of patterns of phoresy are carried out to allow detailed comparisons with patterns of parasitism.

Efficient generation of holographic news ticker in holographic 3DTV

NASA Astrophysics Data System (ADS)

Kim, Seung-Cheol; Kim, Eun-Soo

2009-08-01

News ticker is used to show breaking news or news headlines in conventional 2-D broadcasting system. For the case of the breaking news, the fast creation is need, because the information should be sent quickly. In addition, if holographic 3- D broadcasting system is started in the future, news ticker will remain. On the other hands, some approaches for generation of CGH patterns have been suggested like the ray-tracing method and look-up table (LUT) method. However, these methods have some drawbacks that needs much time or needs huge memory size for look-up table. Recently, a novel LUT (N-LUT) method for fast generation of CGH patterns of 3-D objects with a dramatically reduced LUT without the loss of computational speed was proposed. Therefore, we proposed the method to efficiently generate the holographic news ticker in holographic 3DTV or 3-D movies using N-LUT method. The proposed method is largely consisted of five steps: construction of the LUT for each character, extraction of characters in news ticker, generation and shift of the CGH pattern for news ticker using the LUT for each character, composition of hologram pattern for 3-D video and hologram pattern for news ticker and reconstruct the holographic 3D video with news ticker. To confirm the proposed method, moving car in front of the castle is used as a 3D video and the words 'HOLOGRAM CAPTION GENERATOR' is used as a news ticker. From this simulation results confirmed the feasibility of the proposed method in fast generation of CGH patterns for holographic captions.

Computer Generated Holography with Intensity-Graded Patterns

PubMed Central

Conti, Rossella; Assayag, Osnath; de Sars, Vincent; Guillon, Marc; Emiliani, Valentina

2016-01-01

Computer Generated Holography achieves patterned illumination at the sample plane through phase modulation of the laser beam at the objective back aperture. This is obtained by using liquid crystal-based spatial light modulators (LC-SLMs), which modulate the spatial phase of the incident laser beam. A variety of algorithms is employed to calculate the phase modulation masks addressed to the LC-SLM. These algorithms range from simple gratings-and-lenses to generate multiple diffraction-limited spots, to iterative Fourier-transform algorithms capable of generating arbitrary illumination shapes perfectly tailored on the base of the target contour. Applications for holographic light patterning include multi-trap optical tweezers, patterned voltage imaging and optical control of neuronal excitation using uncaging or optogenetics. These past implementations of computer generated holography used binary input profile to generate binary light distribution at the sample plane. Here we demonstrate that using graded input sources, enables generating intensity graded light patterns and extend the range of application of holographic light illumination. At first, we use intensity-graded holograms to compensate for LC-SLM position dependent diffraction efficiency or sample fluorescence inhomogeneity. Finally we show that intensity-graded holography can be used to equalize photo evoked currents from cells expressing different levels of chanelrhodopsin2 (ChR2), one of the most commonly used optogenetics light gated channels, taking into account the non-linear dependence of channel opening on incident light. PMID:27799896

Generation of isolated asymmetric umbilics in light's polarization

NASA Astrophysics Data System (ADS)

Galvez, Enrique J.; Rojec, Brett L.; Kumar, Vijay; Viswanathan, Nirmal K.

2014-03-01

Polarization-singularity C points, a form of line singularities, are the vectorial counterparts of the optical vortices of spatial modes and fundamental optical features of polarization-spatial modes. Their generation in tailored beams has been limited to so-called "lemon" and "star" C points that contain symmetric dislocations in state-of-polarization patterns. In this Rapid Communication we present the theory and laboratory measurements of two complementary methods to generate isolated asymmetric C points in tailored beams, of which symmetric lemon and star patterns are limiting cases; and we report on the generation of so-called "monstar" patterns, an asymmetric C point with characteristics of both lemons and stars.

A Study of the Female Life Course.

ERIC Educational Resources Information Center

Sugaya, Yoshiko

1985-01-01

A study examined the historical changes that have occurred in the female life course pattern in rural communities in Japan. The family and career patterns of two generations of women were studied from a generation-lineage and age cohort perspective. The older-generation sample consisted of women between the ages of 50 and 79, and the…

From Central Pattern Generator to Sensory Template in the Evolution of Birdsong

ERIC Educational Resources Information Center

Konishi, Masakazu

2010-01-01

Central nervous networks, be they a part of the human brain or a group of neurons in a snail, may be designed to produce distinct patterns of movement. Central pattern generators can account for the development and production of normal vocal signals without auditory feedback in non-songbirds. Songbirds need auditory feedback to develop and…

Breathing simulator of workers for respirator performance test

PubMed Central

YUASA, Hisashi; KUMITA, Mikio; HONDA, Takeshi; KIMURA, Kazushi; NOZAKI, Kosuke; EMI, Hitoshi; OTANI, Yoshio

2014-01-01

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker’s respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns. PMID:25382381

Laser illuminator and optical system for disk patterning

DOEpatents

Hackel, Lloyd A.; Dane, C. Brent; Dixit, Shamasundar N.; Everett, Mathew; Honig, John

2000-01-01

Magnetic recording media are textured over areas designated for contact in order to minimize friction with data transducing heads. In fabricating a hard disk, an aluminum nickel-phosphorous substrate is polished to a specular finish. A mechanical means is then used to roughen an annular area intended to be the head contact band. An optical and mechanical system allows thousands of spots to be generated with each laser pulse, allowing the textured pattern to be rapidly generated with a low repetition rate laser and an uncomplicated mechanical system. The system uses a low power laser, a beam expander, a specially designed phase plate, a prism to deflect the beam, a lens to transmit the diffraction pattern to the far field, a mechanical means to rotate the pattern and a trigger system to fire the laser when sections of the pattern are precisely aligned. The system generates an annular segment of the desired pattern with which the total pattern is generated by rotating the optical system about its optic axis, sensing the rotational position and firing the laser as the annular segment rotates into the next appropriate position. This marking system can be integrated into a disk sputtering system for manufacturing magnetic disks, allowing for a very streamlined manufacturing process.

A fast process development flow by applying design technology co-optimization

NASA Astrophysics Data System (ADS)

Chen, Yi-Chieh; Yeh, Shin-Shing; Ou, Tsong-Hua; Lin, Hung-Yu; Mai, Yung-Ching; Lin, Lawrence; Lai, Jun-Cheng; Lai, Ya Chieh; Xu, Wei; Hurat, Philippe

2017-03-01

Beyond 40 nm technology node, the pattern weak points and hotspot types increase dramatically. The typical patterns for lithography verification suffers huge turn-around-time (TAT) to handle the design complexity. Therefore, in order to speed up process development and increase pattern variety, accurate design guideline and realistic design combinations are required. This paper presented a flow for creating a cell-based layout, a lite realistic design, to early identify problematic patterns which will negatively affect the yield. A new random layout generating method, Design Technology Co-Optimization Pattern Generator (DTCO-PG), is reported in this paper to create cell-based design. DTCO-PG also includes how to characterize the randomness and fuzziness, so that it is able to build up the machine learning scheme which model could be trained by previous results, and then it generates patterns never seen in a lite design. This methodology not only increases pattern diversity but also finds out potential hotspot preliminarily. This paper also demonstrates an integrated flow from DTCO pattern generation to layout modification. Optical Proximity Correction, OPC and lithographic simulation is then applied to DTCO-PG design database to detect hotspots and then hotspots or weak points can be automatically fixed through the procedure or handled manually. This flow benefits the process evolution to have a faster development cycle time, more complexity pattern design, higher probability to find out potential hotspots in early stage, and a more holistic yield ramping operation.

Why the leopard got its spots: relating pattern development to ecology in felids

PubMed Central

Allen, William L.; Cuthill, Innes C.; Scott-Samuel, Nicholas E.; Baddeley, Roland

2011-01-01

A complete explanation of the diversity of animal colour patterns requires an understanding of both the developmental mechanisms generating them and their adaptive value. However, only two previous studies, which involved computer-generated evolving prey, have attempted to make this link. This study examines variation in the camouflage patterns displayed on the flanks of many felids. After controlling for the effects of shared ancestry using a fully resolved molecular phylogeny, this study shows how phenotypes from plausible felid coat pattern generation mechanisms relate to ecology. We found that likelihood of patterning and pattern attributes, such as complexity and irregularity, were related to felids' habitats, arboreality and nocturnality. Our analysis also indicates that disruptive selection is a likely explanation for the prevalence of melanistic forms in Felidae. Furthermore, we show that there is little phylogenetic signal in the visual appearance of felid patterning, indicating that camouflage adapts to ecology over relatively short time scales. Our method could be applied to any taxon with colour patterns that can reasonably be matched to reaction–diffusion and similar models, where the kinetics of the reaction between two or more initially randomly dispersed morphogens determines the outcome of pattern development. PMID:20961899

Concept and analytical basis for revistas - A fast, flexible computer/graphic system for generating periodic satellite coverage patterns

NASA Technical Reports Server (NTRS)

King, J. C.

1976-01-01

The generation of satellite coverage patterns is facilitated by three basic strategies: use of a simplified physical model, permitting rapid closed-form calculation; separation of earth rotation and nodal precession from initial geometric analyses; and use of symmetries to construct traces of indefinite length by repetitive transposition of basic one-quadrant elements. The complete coverage patterns generated consist of a basic nadir trace plus a number of associated off-nadir traces, one for each sensor swath edge to be delineated. Each trace is generated by transposing one or two of the basic quadrant elements into a circle on a nonrotating earth model sphere, after which the circle is expanded into the actual 'helical' pattern by adding rotational displacements to the longitude coordinates. The procedure adapts to the important periodic coverage cases by direct insertion of the characteristic integers N and R (days and orbital revolutions, respectively, per coverage period).

Changing clothes easily: connexin41.8 regulates skin pattern variation.

PubMed

Watanabe, Masakatsu; Kondo, Shigeru

2012-05-01

The skin patterns of animals are very important for their survival, yet the mechanisms involved in skin pattern formation remain unresolved. Turing's reaction-diffusion model presents a well-known mathematical explanation of how animal skin patterns are formed, and this model can predict various animal patterns that are observed in nature. In this study, we used transgenic zebrafish to generate various artificial skin patterns including a narrow stripe with a wide interstripe, a narrow stripe with a narrow interstripe, a labyrinth, and a 'leopard' pattern (or donut-like ring pattern). In this process, connexin41.8 (or its mutant form) was ectopically expressed using the mitfa promoter. Specifically, the leopard pattern was generated as predicted by Turing's model. Our results demonstrate that the pigment cells in animal skin have the potential and plasticity to establish various patterns and that the reaction-diffusion principle can predict skin patterns of animals. © 2012 John Wiley & Sons A/S.

A random generation approach to pattern library creation for full chip lithographic simulation

NASA Astrophysics Data System (ADS)

Zou, Elain; Hong, Sid; Liu, Limei; Huang, Lucas; Yang, Legender; Kabeel, Aliaa; Madkour, Kareem; ElManhawy, Wael; Kwan, Joe; Du, Chunshan; Hu, Xinyi; Wan, Qijian; Zhang, Recoo

2017-04-01

As technology advances, the need for running lithographic (litho) checking for early detection of hotspots before tapeout has become essential. This process is important at all levels—from designing standard cells and small blocks to large intellectual property (IP) and full chip layouts. Litho simulation provides high accuracy for detecting printability issues due to problematic geometries, but it has the disadvantage of slow performance on large designs and blocks [1]. Foundries have found a good compromise solution for running litho simulation on full chips by filtering out potential candidate hotspot patterns using pattern matching (PM), and then performing simulation on the matched locations. The challenge has always been how to easily create a PM library of candidate patterns that provides both comprehensive coverage for litho problems and fast runtime performance. This paper presents a new strategy for generating candidate real design patterns through a random generation approach using a layout schema generator (LSG) utility. The output patterns from the LSG are simulated, and then classified by a scoring mechanism that categorizes patterns according to the severity of the hotspots, probability of their presence in the design, and the likelihood of the pattern causing a hotspot. The scoring output helps to filter out the yield problematic patterns that should be removed from any standard cell design, and also to define potential problematic patterns that must be simulated within a bigger context to decide whether or not they represent an actual hotspot. This flow is demonstrated on SMIC 14nm technology, creating a candidate hotspot pattern library that can be used in full chip simulation with very high coverage and robust performance.

Quality issues in blue noise halftoning

NASA Astrophysics Data System (ADS)

Yu, Qing; Parker, Kevin J.

1998-01-01

The blue noise mask (BNM) is a halftone screen that produces unstructured visually pleasing dot patterns. The BNM combines the blue-noise characteristics of error diffusion and the simplicity of ordered dither. A BNM is constructed by designing a set of interdependent binary patterns for individual gray levels. In this paper, we investigate the quality issues in blue-noise binary pattern design and mask generation as well as in application to color reproduction. Using a global filtering technique and a local 'force' process for rearranging black and white pixels, we are able to generate a series of binary patterns, all representing a certain gray level, ranging from white-noise pattern to highly structured pattern. The quality of these individual patterns are studied in terms of low-frequency structure and graininess. Typically, the low-frequency structure (LF) is identified with a measurement of the energy around dc in the spatial frequency domain, while the graininess is quantified by a measurement of the average minimum distance (AMD) between minority dots as well as the kurtosis of the local kurtosis distribution (KLK) for minority pixels of the binary pattern. A set of partial BNMs are generated by using the different patterns as unique starting 'seeds.' In this way, we are able to study the quality of binary patterns over a range of gray levels. We observe that the optimality of a binary pattern for mask generation is related to its own quality mertirc values as well as the transition smoothness of those quality metric values over neighboring levels. Several schemes have been developed to apply blue-noise halftoning to color reproduction. Different schemes generate halftone patterns with different textures. In a previous paper, a human visual system (HVS) model was used to study the color halftone quality in terms of luminance and chrominance error in CIELAB color space. In this paper, a new series of psycho-visual experiments address the 'preferred' color rendering among four different blue noise halftoning schemes. The experimental results will be interpreted with respect to the proposed halftone quality metrics.

Mask pattern generator employing EPL technology

NASA Astrophysics Data System (ADS)

Yoshioka, Nobuyuki; Yamabe, Masaki; Wakamiya, Wataru; Endo, Nobuhiro

2003-08-01

Mask cost is one of crucial issues in device fabrication, especially in SoC (System on a Chip) with small-volume production. The cost mainly depends on productivity of mask manufacturing tools such as mask writers and defect inspection tools. EPL (Electron Projection Lithography) has been developing as a high-throughput electron beam exposure technology that will succeed optical lithography. The application of EPL technology to mask writing will result in high productivity and contribute to decrease the mask cost. The concept of a mask pattern generator employing EPL technology is proposed in this paper. It is very similar to EPL technology used for pattern printing on a wafer. The mask patterns on the glass substrate are exposed by projecting the basic circuit patterns formed on the mother EPL mask. One example of the mother EPL mask is a stencil type made with 200-mm Si wafer. The basic circuit patterns are IP patterns and logical primitive patterns such as cell libraries (AND, OR, Inverter, Flip-Flop and etc.) to express the SoC device patterns. Since the SoC patterns are exposed with its collective units such as IP and logical primitive patterns by using this method, the high throughput will be expected comparing with conventional mask E-beam writers. In this paper, the mask pattern generator with the EPL technology is proposed. The concept, its advantages and issues to be solved are discussed.

Automating the generation of lexical patterns for processing free text in clinical documents.

PubMed

Meng, Frank; Morioka, Craig

2015-09-01

Many tasks in natural language processing utilize lexical pattern-matching techniques, including information extraction (IE), negation identification, and syntactic parsing. However, it is generally difficult to derive patterns that achieve acceptable levels of recall while also remaining highly precise. We present a multiple sequence alignment (MSA)-based technique that automatically generates patterns, thereby leveraging language usage to determine the context of words that influence a given target. MSAs capture the commonalities among word sequences and are able to reveal areas of linguistic stability and variation. In this way, MSAs provide a systemic approach to generating lexical patterns that are generalizable, which will both increase recall levels and maintain high levels of precision. The MSA-generated patterns exhibited consistent F1-, F.5-, and F2- scores compared to two baseline techniques for IE across four different tasks. Both baseline techniques performed well for some tasks and less well for others, but MSA was found to consistently perform at a high level for all four tasks. The performance of MSA on the four extraction tasks indicates the method's versatility. The results show that the MSA-based patterns are able to handle the extraction of individual data elements as well as relations between two concepts without the need for large amounts of manual intervention. We presented an MSA-based framework for generating lexical patterns that showed consistently high levels of both performance and recall over four different extraction tasks when compared to baseline methods. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Center for the Study of Rhythmic Processes.

DTIC Science & Technology

1987-10-20

pattern generators Neural network Spinal cord Mathematical modeling Neuromodulators Regeneration Sensory feedback 19 ABSTRACT (Continue on reverse if...generator circuit. Trends in Neurosciences 9: 432-437. Marder, E. (1987) Neurotransmitters and neuromodulators . In Selverston, A.I. and Moulins, M. The...relating to the effects of neuromodulators on the output of the lobster stomatogastric central pattern generator. (See Sections III and IV.) 2. Trainig

Photomask and pattern programming manual

NASA Technical Reports Server (NTRS)

Kirschman, R. K.

1978-01-01

A user's manual for a set of computer programs written in FORTRAN for the layout and generation of photomasks is presented. A limited amount of related information on photomasks, their design, and use is included. Input to the programs includes data describing the photomask design. Possible outputs include plots of the layout and a magnetic tape for controlling generation of the photomask by a pattern generator.

A Changing Trend In Eruption Age and Pattern of First Deciduous Tooth: Correlation to Feeding Pattern

PubMed Central

Kohli, Monika V; Patil, Gururaj B.; Kulkarni, Narayan B.; Bagalkot, Kishore; Purohit, Zarana; Dave, Nilixa; Sagari, Shitalkumar G; Malaghan, Manjunath

2014-01-01

Background: Feeding mode during infancy and its effect on deciduous tooth appearance in oral cavity in two generations and among genders. Aim and Objective: Study aimed to compare and correlate times and patterns of deciduous tooth eruption in breastfeeding (OBF), partial breastfeeding (PBF) and spoon feeding (SF) infants and initiation of semisolid food feeding (SSF) in infants. It also aimed to address the variations in the time of eruption of first deciduous tooth and its pattern in two generations who had more than a decade of difference in ages. Materials and methods: An open-ended questionnaire study was conducted on mothers of 265 patients from two groups, generation 1 (G1)- adults who were aged 20-35 years and second group, generation 2 (G2) - children who were below 5 years of age . Results: A statistical significance was observed with respect to age, gender, generations, and frequency of breastfeeding, partial breastfeeding and time of initiation of semisolid food. Conclusion: There is a delayed eruption of teeth in present generation. For girls, it occurs at age of 7.88 months and for boys, it occurs at the age of 8.08 months. PMID:24783136

A Comparative Study of Random Patterns for Digital Image Correlation

NASA Astrophysics Data System (ADS)

Stoilov, G.; Kavardzhikov, V.; Pashkouleva, D.

2012-06-01

Digital Image Correlation (DIC) is a computer based image analysis technique utilizing random patterns, which finds applications in experimental mechanics of solids and structures. In this paper a comparative study of three simulated random patterns is done. One of them is generated according to a new algorithm, introduced by the authors. A criterion for quantitative evaluation of random patterns after the calculation of their autocorrelation functions is introduced. The patterns' deformations are simulated numerically and realized experimentally. The displacements are measured by using the DIC method. Tensile tests are performed after printing the generated random patterns on surfaces of standard iron sheet specimens. It is found that the new designed random pattern keeps relatively good quality until reaching 20% deformation.

Deaf-And-Mute Sign Language Generation System

NASA Astrophysics Data System (ADS)

Kawai, Hideo; Tamura, Shinichi

1984-08-01

We have developed a system which can recognize speech and generate the corresponding animation-like sign language sequence. The system is implemented in a popular personal computer. This has three video-RAM's and a voice recognition board which can recognize only registered voice of a specific speaker. Presently, fourty sign language patterns and fifty finger spellings are stored in two floppy disks. Each sign pattern is composed of one to four sub-patterns. That is, if the pattern is composed of one sub-pattern, it is displayed as a still pattern. If not, it is displayed as a motion pattern. This system will help communications between deaf-and-mute persons and healthy persons. In order to display in high speed, almost programs are written in a machine language.

Scalable patterning using laser-induced shock waves

NASA Astrophysics Data System (ADS)

Ilhom, Saidjafarzoda; Kholikov, Khomidkhodza; Li, Peizhen; Ottman, Claire; Sanford, Dylan; Thomas, Zachary; San, Omer; Karaca, Haluk E.; Er, Ali O.

2018-04-01

An advanced direct imprinting method with low cost, quick, and minimal environmental impact to create a thermally controllable surface pattern using the laser pulses is reported. Patterned microindents were generated on Ni50Ti50 shape memory alloys and aluminum using an Nd: YAG laser operating at 1064 nm combined with a suitable transparent overlay, a sacrificial layer of graphite, and copper grid. Laser pulses at different energy densities, which generate pressure pulses up to a few GPa on the surface, were focused through the confinement medium, ablating the copper grid to create plasma and transferring the grid pattern onto the surface. Scanning electron microscope and optical microscope images show that various patterns were obtained on the surface with high fidelity. One-dimensional profile analysis indicates that the depth of the patterned sample initially increases with the laser energy and later levels off. Our simulations of laser irradiation process also confirm that high temperature and high pressure could be generated when the laser energy density of 2 J/cm2 is used.

Diffractive elements for generating microscale laser beam patterns: a Y2K problem

NASA Astrophysics Data System (ADS)

Teiwes, Stephan; Krueger, Sven; Wernicke, Guenther K.; Ferstl, Margit

2000-03-01

Lasers are widely used in industrial fabrication for engraving, cutting and many other purposes. However, material processing at very small scales is still a matter of concern. Advances in diffractive optics could provide for laser systems that could be used for engraving or cutting of micro-scale patterns at high speeds. In our paper we focus on the design of diffractive elements which can be used for this special application. It is a common desire in material processing to apply 'discrete' as well as 'continuous' beam patterns. Especially, the latter case is difficult to handle as typical micro-scale patterns are characterized by bad band-limitation properties, and as speckles can easily occur in beam patterns. It is shown in this paper that a standard iterative design method usually fails to obtain diffractive elements that generate diffraction patterns with acceptable quality. Insights gained from an analysis of the design problems are used to optimize the iterative design method. We demonstrate applicability and success of our approach by the design of diffractive phase elements that generate a discrete and a continuous 'Y2K' pattern.

Module Based Complexity Formation: Periodic Patterning in Feathers and Hairs

PubMed Central

Chuong, Cheng-Ming; Yeh, Chao-Yuan; Jiang, Ting-Xin; Widelitz, Randall

2012-01-01

Patterns describe order which emerges from homogeneity. Complex patterns on the integument are striking because of their visibility throughout an organism's lifespan. Periodic patterning is an effective design because the ensemble of hair or feather follicles (modules) allows the generation of complexity, including regional variations and cyclic regeneration, giving the skin appendages a new lease on life. Spatial patterns include the arrangements of feathers and hairs in specified number, size, and spacing. We explore how a field of equivalent progenitor cells can generate periodically arranged modules based on genetic information, physical-chemical rules and developmental timing. Reconstitution experiments suggest a competitive equilibrium regulated by activators / inhibitors involving Turing reaction-diffusion. Temporal patterns result from oscillating stem cell activities within each module (micro-environment regulation), reflected as growth (anagen) and resting (telogen) phases during the cycling of feather and hair follicles. Stimulating modules with activators initiates the spread of regenerative hair waves, while global inhibitors outside each module (macro-environment) prevent this. Different wave patterns can be simulated by Cellular Automata principles. Hormonal status and seasonal changes can modulate appendage phenotypes, leading to “organ metamorphosis”, with multiple ectodermal organ phenotypes generated from the same precursors. We discuss potential evolutionary novel steps using this module based complexity in several amniote integument organs, exemplified by the spectacular peacock feather pattern. We thus explore the application of the acquired knowledge of patterning in tissue engineering. New hair follicles can be generated after wounding. Hairs and feathers can be reconstituted through self-organization of dissociated progenitor cells. PMID:23539312

Module-based complexity formation: periodic patterning in feathers and hairs.

PubMed

Chuong, Cheng-Ming; Yeh, Chao-Yuan; Jiang, Ting-Xin; Widelitz, Randall

2013-01-01

Patterns describe order which emerges from homogeneity. Complex patterns on the integument are striking because of their visibility throughout an organism’s lifespan. Periodic patterning is an effective design because the ensemble of hair or feather follicles (modules) allows the generation of complexity, including regional variations and cyclic regeneration, giving the skin appendages a new lease on life. Spatial patterns include the arrangements of feathers and hairs in specific number, size, and spacing.We explorehowa field of equivalent progenitor cells can generate periodically arranged modules based on genetic information, physical–chemical rules and developmental timing. Reconstitution experiments suggest a competitive equilibrium regulated by activators/inhibitors involving Turing reaction-diffusion. Temporal patterns result from oscillating stem cell activities within each module (microenvironment regulation), reflected as growth (anagen) and resting (telogen) phases during the cycling of feather and hair follicles. Stimulating modules with activators initiates the spread of regenerative hair waves, while global inhibitors outside each module (macroenvironment) prevent this. Different wave patterns can be simulated by cellular automata principles. Hormonal status and seasonal changes can modulate appendage phenotypes, leading to ‘organ metamorphosis’, with multiple ectodermal organ phenotypes generated from the same precursors. We discuss potential novel evolutionary steps using this module-based complexity in several amniote integument organs, exemplified by the spectacular peacock feather pattern. We thus explore the application of the acquired knowledge of patterning in tissue engineering. New hair follicles can be generated after wounding. Hairs and feathers can be reconstituted through self-organization of dissociated progenitor cells. © 2012 Wiley Periodicals, Inc.

Efficient generation of 3D hologram for American Sign Language using look-up table

NASA Astrophysics Data System (ADS)

Park, Joo-Sup; Kim, Seung-Cheol; Kim, Eun-Soo

2010-02-01

American Sign Language (ASL) is one of the languages giving the greatest help for communication of the hearing impaired person. Current 2-D broadcasting, 2-D movies are used the ASL to give some information, help understand the situation of the scene and translate the foreign language. These ASL will not be disappeared in future three-dimensional (3-D) broadcasting or 3-D movies because the usefulness of the ASL. On the other hands, some approaches for generation of CGH patterns have been suggested like the ray-tracing method and look-up table (LUT) method. However, these methods have some drawbacks that needs much time or needs huge memory size for look-up table. Recently, a novel LUT (N-LUT) method for fast generation of CGH patterns of 3-D objects with a dramatically reduced LUT without the loss of computational speed was proposed. Therefore, we proposed the method to efficiently generate the holographic ASL in holographic 3DTV or 3-D movies using look-up table method. The proposed method is largely consisted of five steps: construction of the LUT for each ASL images, extraction of characters in scripts or situation, call the fringe patterns for characters in the LUT for each ASL, composition of hologram pattern for 3-D video and hologram pattern for ASL and reconstruct the holographic 3D video with ASL. Some simulation results confirmed the feasibility of the proposed method in efficient generation of CGH patterns for ASL.

An image-processing methodology for extracting bloodstain pattern features.

PubMed

Arthur, Ravishka M; Humburg, Philomena J; Hoogenboom, Jerry; Baiker, Martin; Taylor, Michael C; de Bruin, Karla G

2017-08-01

There is a growing trend in forensic science to develop methods to make forensic pattern comparison tasks more objective. This has generally involved the application of suitable image-processing methods to provide numerical data for identification or comparison. This paper outlines a unique image-processing methodology that can be utilised by analysts to generate reliable pattern data that will assist them in forming objective conclusions about a pattern. A range of features were defined and extracted from a laboratory-generated impact spatter pattern. These features were based in part on bloodstain properties commonly used in the analysis of spatter bloodstain patterns. The values of these features were consistent with properties reported qualitatively for such patterns. The image-processing method developed shows considerable promise as a way to establish measurable discriminating pattern criteria that are lacking in current bloodstain pattern taxonomies. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of rainfall patterns and land cover on the subsurface flow generation of sloping Ferralsols in southern China

PubMed Central

Yang, Jie; Tang, Chongjun; Chen, Lihua; Liu, Yaojun; Wang, Lingyun

2017-01-01

Rainfall patterns and land cover are two important factors that affect the runoff generation process. To determine the surface and subsurface flows associated with different rainfall patterns on sloping Ferralsols under different land cover types, observational data related to surface and subsurface flows from 5 m × 15 m plots were collected from 2010 to 2012. The experiment was conducted to assess three land cover types (grass, litter cover and bare land) in the Jiangxi Provincial Soil and Water Conservation Ecological Park. During the study period, 114 natural rainfall events produced subsurface flow and were divided into four groups using k-means clustering according to rainfall duration, rainfall depth and maximum 30-min rainfall intensity. The results showed that the total runoff and surface flow values were highest for bare land under all four rainfall patterns and lowest for the covered plots. However, covered plots generated higher subsurface flow values than bare land. Moreover, the surface and subsurface flows associated with the three land cover types differed significantly under different rainfall patterns. Rainfall patterns with low intensities and long durations created more subsurface flow in the grass and litter cover types, whereas rainfall patterns with high intensities and short durations resulted in greater surface flow over bare land. Rainfall pattern I had the highest surface and subsurface flow values for the grass cover and litter cover types. The highest surface flow value and lowest subsurface flow value for bare land occurred under rainfall pattern IV. Rainfall pattern II generated the highest subsurface flow value for bare land. Therefore, grass or litter cover are able to convert more surface flow into subsurface flow under different rainfall patterns. The rainfall patterns studied had greater effects on subsurface flow than on total runoff and surface flow for covered surfaces, as well as a greater effect on surface flows associated with bare land. PMID:28792507

Generative electronic background music system

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

Mazurowski, Lukasz

In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

Passive Transport Disrupts Grid Signals in the Parahippocampal Cortex.

PubMed

Winter, Shawn S; Mehlman, Max L; Clark, Benjamin J; Taube, Jeffrey S

2015-10-05

Navigation is usually thought of relative to landmarks, but neural signals representing space also use information generated by an animal's movements. These signals include grid cells, which fire at multiple locations, forming a repeating grid pattern. Grid cell generation depends upon theta rhythm, a 6-10 Hz electroencephalogram (EEG) oscillation that is modulated by the animals' movement velocity. We passively moved rats in a clear cart to eliminate motor related self-movement cues that drive moment-to-moment changes in theta rhythmicity. We found that passive movement maintained theta power and frequency at levels equivalent to low active movement velocity, spared overall head-direction (HD) cell characteristics, but abolished both velocity modulation of theta rhythmicity and grid cell firing patterns. These results indicate that self-movement motor cues are necessary for generating grid-specific firing patterns, possibly by driving velocity modulation of theta rhythmicity, which may be used as a speed signal to generate the repeating pattern of grid cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

Out-of-plane stretching for simultaneous generation of different morphological wrinkles on a soft matter

NASA Astrophysics Data System (ADS)

Li, Xin; Zhao, Zhi-Jun; Park, Sang-Hu

2016-07-01

This study demonstrates a simple and flexible out-of-plane induced mechanical stretching method for generating labyrinthic, waving, and straight orderly microscale directional wrinkles. Different complex wrinkling patterns were fabricated simultaneously using a UV-curable thin layer of resin NOA-68T that was coated on a soft foundation. Then an out-of-plane pre-straining deformation was applied by a specially designed punch to generate internal elastic instabilities. The surface wrinkling pattern characteristics (shapes and size) changed according to the amount of punch stroke (pre-strain) and the cross-sectional shape of the punch. This study confirms the usefulness of this method for controlling and generating local wrinkling patterns for diverse applications. As an example, the contact angles of a water droplet on a local area of the same pattern were measured to identify the change in wettability with respect to different wrinkling shapes. This method can be utilized in topographical tunable wrinkle fabrication for local surface modification.

Passive Transport Disrupts Grid Signals in the Parahippocampal Cortex

PubMed Central

Winter, Shawn S.; Mehlman, Max L.; Clark, Benjamin J.; Taube, Jeffrey S.

2015-01-01

Summary Navigation is usually thought of relative to landmarks, but neural signals representing space also use information generated by an animal’s movements. These signals include grid cells, which fire at multiple locations forming a repeating grid pattern. Grid cell generation depends upon theta rhythm, a 6-10 Hz EEG oscillation that is modulated by the animals’ movement velocity. We passively moved rats in a clear cart to eliminate motor related self-movement cues that drive moment-to-moment changes in theta rhythmicity. We found that passive movement maintained theta power and frequency at levels equivalent to low active movement velocity, spared overall HD cell characteristics, and abolished velocity modulation of theta rhythmicity and grid cell firing patterns. These results indicate that self-movement motor cues are necessary for generating grid-specific firing patterns, possibly by driving velocity modulation of theta rhythmicity. Velocity modulation of theta may be used as a speed signal to generate the repeating pattern of grid cells. PMID:26387719

Generative Models of Segregation: Investigating Model-Generated Patterns of Residential Segregation by Ethnicity and Socioeconomic Status

PubMed Central

Fossett, Mark

2011-01-01

This paper considers the potential for using agent models to explore theories of residential segregation in urban areas. Results of generative experiments conducted using an agent-based simulation of segregation dynamics document that varying a small number of model parameters representing constructs from urban-ecological theories of segregation can generate a wide range of qualitatively distinct and substantively interesting segregation patterns. The results suggest how complex, macro-level patterns of residential segregation can arise from a small set of simple micro-level social dynamics operating within particular urban-demographic contexts. The promise and current limitations of agent simulation studies are noted and optimism is expressed regarding the potential for such studies to engage and contribute to the broader research literature on residential segregation. PMID:21379372

Healthy eating patterns associated with acculturation, sex and BMI among Mexican Americans.

PubMed

Reininger, Belinda; Lee, MinJae; Jennings, Rose; Evans, Alexandra; Vidoni, Michelle

2017-05-01

Examine relationships of healthy and unhealthy dietary patterns with BMI, sex, age and acculturation among Mexican Americans. Cross-sectional. Participants completed culturally tailored Healthy and Unhealthy Eating Indices. Multivariable mixed-effect Poisson regression models compared food pattern index scores and dietary intake of specific foods by BMI, sex, age and acculturation defined by language preference and generational status. Participants recruited from the Cameron County Hispanic Cohort study, Texas-Mexico border region, between 2008 and 2011. Mexican-American males and females aged 18-97 years (n 1250). Participants were primarily female (55·3 %), overweight or obese (85·7 %), preferred Spanish language (68·0 %) and first-generation status (60·3 %). Among first-generation participants, bilingual participants were less likely to have a healthy eating pattern than preferred Spanish-speaking participants (rate ratio (RR)=0·79, P=0·0218). This association was also found in males (RR=0·81, P=0·0098). Preferred English-speaking females were less likely to consume healthy foods than preferred Spanish-speaking females (RR=0·84, P=0·0293). Among second-generation participants, preferred English-speaking participants were more likely to report a higher unhealthy eating pattern than preferred Spanish-speaking participants (RR=1·23, P=0·0114). Higher unhealthy eating patterns were also found in females who preferred English v. females who preferred Spanish (RR=1·23, P=0·0107) or were bilingual (RR=1·26, P=0·0159). Younger, male participants were more likely to have a higher unhealthy eating pattern. BMI and diabetes status were not significantly associated with healthy or unhealthy eating patterns. Acculturation, age, sex and education are associated with healthy and unhealthy dietary patterns. Nutrition interventions for Mexican Americans should tailor approaches by these characteristics.

Generating Customized Verifiers for Automatically Generated Code

NASA Technical Reports Server (NTRS)

Denney, Ewen; Fischer, Bernd

2008-01-01

Program verification using Hoare-style techniques requires many logical annotations. We have previously developed a generic annotation inference algorithm that weaves in all annotations required to certify safety properties for automatically generated code. It uses patterns to capture generator- and property-specific code idioms and property-specific meta-program fragments to construct the annotations. The algorithm is customized by specifying the code patterns and integrating them with the meta-program fragments for annotation construction. However, this is difficult since it involves tedious and error-prone low-level term manipulations. Here, we describe an annotation schema compiler that largely automates this customization task using generative techniques. It takes a collection of high-level declarative annotation schemas tailored towards a specific code generator and safety property, and generates all customized analysis functions and glue code required for interfacing with the generic algorithm core, thus effectively creating a customized annotation inference algorithm. The compiler raises the level of abstraction and simplifies schema development and maintenance. It also takes care of some more routine aspects of formulating patterns and schemas, in particular handling of irrelevant program fragments and irrelevant variance in the program structure, which reduces the size, complexity, and number of different patterns and annotation schemas that are required. The improvements described here make it easier and faster to customize the system to a new safety property or a new generator, and we demonstrate this by customizing it to certify frame safety of space flight navigation code that was automatically generated from Simulink models by MathWorks' Real-Time Workshop.

Biological pattern formation: from basic mechanisms to complex structures

NASA Astrophysics Data System (ADS)

Koch, A. J.; Meinhardt, H.

1994-10-01

The reliable development of highly complex organisms is an intriguing and fascinating problem. The genetic material is, as a rule, the same in each cell of an organism. How then do cells, under the influence of their common genes, produce spatial patterns? Simple models are discussed that describe the generation of patterns out of an initially nearly homogeneous state. They are based on nonlinear interactions of at least two chemicals and on their diffusion. The concepts of local autocatalysis and of long-range inhibition play a fundamental role. Numerical simulations show that the models account for many basic biological observations such as the regeneration of a pattern after excision of tissue or the production of regular (or nearly regular) arrays of organs during (or after) completion of growth. Very complex patterns can be generated in a reproducible way by hierarchical coupling of several such elementary reactions. Applications to animal coats and to the generation of polygonally shaped patterns are provided. It is further shown how to generate a strictly periodic pattern of units that themselves exhibit a complex and polar fine structure. This is illustrated by two examples: the assembly of photoreceptor cells in the eye of Drosophila and the positioning of leaves and axillary buds in a growing shoot. In both cases, the substructures have to achieve an internal polarity under the influence of some primary pattern-forming system existing in the fly's eye or in the plant. The fact that similar models can describe essential steps in organisms as distantly related as animals and plants suggests that they reveal some universal mechanisms.

Analysis of Different Ploidy and Parent–Offspring Genomic DNA Methylation in the Loach Misgurnus anguillicaudatus

PubMed Central

Zhou, He; Ma, Tian-Yu; Zhang, Rui; Xu, Qi-Zheng; Shen, Fu; Qin, Yan-Jie; Xu, Wen; Wang, Yuan; Li, Ya-Juan

2016-01-01

In this study, we selected natural polyploidy loach (diploid, triploid and tetraploid) and hybrid F1 generation obverse cross (4 × 2) and inverse cross (2 × 4) by diploids and tetraploids as the research model. The MSAP (methylation-sensitive amplified polymorphism) reaction system was established by our laboratory to explore methylation levels and pattern diversification features at the whole genome level of the polyploidy loach. The results showed that the total methylation and full methylation rates decreased on increased ploidy individuals; moreover, the hemimethylation rate showed no consistent pattern. Compared with diploid loach, the methylation patterns of tetraploid sites changed 68.17%, and the methylation patterns of triploid sites changed 73.05%. The proportion of hypermethylation genes is significantly higher than the proportion of demethylation genes. The methylation level of reciprocal cross F1 generation is lower than the male diploid and higher than the female tetraploid. The hemimethylation and total methylation rate of the cross hybrid F1 generation is significantly higher than the orthogonal F1 generation (p < 0.01). After readjusting, the methylation pattern of genome DNA of reciprocal hybrids changed 69.59% and 72.83%, respectively. PMID:27556458

Microstrip Antenna Generates Circularly Polarized Beam

NASA Technical Reports Server (NTRS)

Huang, J.

1986-01-01

Circular microstrip antenna excited with higher order transverse magnetic (TM) modes generates circularly polarized, conical radiation patterns. Found both theoretically and experimentally that peak direction of radiation pattern is varied within wide angular range by combination of mode selection and loading substrate with materials of different dielectric constants.

The hybrid modulatory/pattern generating N1L interneuron in the buccal feeding system of Lymnaea is cholinergic.

PubMed

Vehovszky, A; Elliott, C J

1995-01-01

This study examines neurotransmission between identified buccal interneurons in the feeding system of the snail Lymnaea stagnalis. We compare the pharmacology of the individual synaptic connections from a hybrid modulatory/pattern generating interneuron (N1L) to a pattern generating interneuron (N1M) with that from a modulatory interneuron (SO) to the same follower cell (N1M). The pharmacological properties of the N1L to N1M and the SO to N1M connections closely resemble each other. Both interneurons produce fast cholinergic EPSPs as judged by the blocking effects of cholinergic antagonists hexamethonium, d-tubocurarine and the cholinergic neurotoxin AF-64A. A slower, more complex but non-cholinergic component of the synaptic response is also present after stimulating either the presynaptic N1L or SO interneurons. This second component of the postsynaptic response is not dopaminergic, on the basis of its persistence in the presence of dopaminergic antagonists ergometrine and fluphenazine and the dopaminergic neurotoxin MPP+. We conclude that, although there has been an evolutionary divergence in function, the modulatory SO and the hybrid modulatory/pattern generating N1L are pharmacologically similar. Neither of them contributes directly to dopaminergic modulation of the feeding activity. These neurons also resemble the N1M protraction phase pattern generating neurons which are cholinergic (Elliott and Kemenes, 1992).

Feedback Signal from Motoneurons Influences a Rhythmic Pattern Generator.

PubMed

Rotstein, Horacio G; Schneider, Elisa; Szczupak, Lidia

2017-09-20

Motoneurons are not mere output units of neuronal circuits that control motor behavior but participate in pattern generation. Research on the circuit that controls the crawling motor behavior in leeches indicated that motoneurons participate as modulators of this rhythmic motor pattern. Crawling results from successive bouts of elongation and contraction of the whole leech body. In the isolated segmental ganglia, dopamine can induce a rhythmic antiphasic activity of the motoneurons that control contraction (DE-3 motoneurons) and elongation (CV motoneurons). The study was performed in isolated ganglia where manipulation of the activity of specific motoneurons was performed in the course of fictive crawling ( crawling ). In this study, the membrane potential of CV was manipulated while crawling was monitored through the rhythmic activity of DE-3. Matching behavioral observations that show that elongation dominates the rhythmic pattern, the electrophysiological activity of CV motoneurons dominates the cycle. Brief excitation of CV motoneurons during crawling episodes resets the rhythmic activity of DE-3, indicating that CV feeds back to the rhythmic pattern generator. CV hyperpolarization accelerated the rhythm to an extent that depended on the magnitude of the cycle period, suggesting that CV exerted a positive feedback on the unit(s) of the pattern generator that controls the elongation phase. A simple computational model was implemented to test the consequences of such feedback. The simulations indicate that the duty cycle of CV depended on the strength of the positive feedback between CV and the pattern generator circuit. SIGNIFICANCE STATEMENT Rhythmic movements of animals are controlled by neuronal networks that have been conceived as hierarchical structures. At the basis of this hierarchy, we find the motoneurons, few neurons at the top control global aspects of the behavior (e.g., onset, duration); and within these two ends, specific neuronal circuits control the actual rhythmic pattern of movements. We have investigated whether motoneurons are limited to function as output units. Analysis of the network that controls crawling behavior in the leech has clearly indicated that motoneurons, in addition to controlling muscle activity, send signals to the pattern generator. Physiological and modeling studies on the role of specific motoneurons suggest that these feedback signals modulate the phase relationship of the rhythmic activity. Copyright © 2017 the authors 0270-6474/17/379149-11$15.00/0.

Multiple bunch HOM evaluation for ERL cavities

DOE PAGES

Xu, Chen; Ben-Zvi, I.; Blaskiewicz, Michael M.; ...

2017-06-15

In this paper we investigate the effect of the bunch pattern in a linac on the Higher Order Mode (HOM) power generation. The future ERL-based electron–ion collider eRHIC at BNL is used as an illustrative example. This ERL has multiple high current Superconducting Radiofrequency (SRF) 5-cell cavities. The HOM power generated when a single bunch traverses the cavity is estimated by the corresponding loss factor. Multiple re-circulations through the Energy Recovery Linac (ERL) create a specific bunch pattern. In this case the loss factor can be different than the single bunch loss factor. HOM power can vary dramatically when themore » ERL bunch pattern changes. The HOM power generation can be surveyed in the time and frequency domains. We estimate the average HOM power in a 5-cell cavity with different ERL bunch patterns.« less

Multiple bunch HOM evaluation for ERL cavities

NASA Astrophysics Data System (ADS)

Xu, Chen; Ben-Zvi, I.; Blaskiewicz, Michael M.; Hao, Yue; Ptitsyn, Vadim

2017-09-01

In this work we investigate the effect of the bunch pattern in a linac on the Higher Order Mode (HOM) power generation. The future ERL-based electron-ion collider eRHIC at BNL is used as an illustrative example. This ERL has multiple high current Superconducting Radiofrequency (SRF) 5-cell cavities. The HOM power generated when a single bunch traverses the cavity is estimated by the corresponding loss factor. Multiple re-circulations through the Energy Recovery Linac (ERL) create a specific bunch pattern. In this case the loss factor can be different than the single bunch loss factor. HOM power can vary dramatically when the ERL bunch pattern changes. The HOM power generation can be surveyed in the time and frequency domains. We estimate the average HOM power in a 5-cell cavity with different ERL bunch patterns.

Multiple bunch HOM evaluation for ERL cavities

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

Xu, Chen; Ben-Zvi, I.; Blaskiewicz, Michael M.

In this paper we investigate the effect of the bunch pattern in a linac on the Higher Order Mode (HOM) power generation. The future ERL-based electron–ion collider eRHIC at BNL is used as an illustrative example. This ERL has multiple high current Superconducting Radiofrequency (SRF) 5-cell cavities. The HOM power generated when a single bunch traverses the cavity is estimated by the corresponding loss factor. Multiple re-circulations through the Energy Recovery Linac (ERL) create a specific bunch pattern. In this case the loss factor can be different than the single bunch loss factor. HOM power can vary dramatically when themore » ERL bunch pattern changes. The HOM power generation can be surveyed in the time and frequency domains. We estimate the average HOM power in a 5-cell cavity with different ERL bunch patterns.« less

The Intergenerational Continuity of Fathers' Absence in a Socioeconomically Disadvantaged Sample

ERIC Educational Resources Information Center

Pougnet, Erin; Serbin, Lisa A.; Stack, Dale M.; Ledingham, Jane E.; Schwartzman, Alex E.

2012-01-01

Fathers' absence is a pattern that shows intergenerational continuity, most notably within disadvantaged populations. The process whereby this pattern is repeated across generations is not well understood. Using data from the Concordia Longitudinal Risk Project, the authors investigated pathways between fathers' absence in 1 generation and the…

Mathematically guided approaches to distinguish models of periodic patterning

PubMed Central

Hiscock, Tom W.; Megason, Sean G.

2015-01-01

How periodic patterns are generated is an open question. A number of mechanisms have been proposed – most famously, Turing's reaction-diffusion model. However, many theoretical and experimental studies focus on the Turing mechanism while ignoring other possible mechanisms. Here, we use a general model of periodic patterning to show that different types of mechanism (molecular, cellular, mechanical) can generate qualitatively similar final patterns. Observation of final patterns is therefore not sufficient to favour one mechanism over others. However, we propose that a mathematical approach can help to guide the design of experiments that can distinguish between different mechanisms, and illustrate the potential value of this approach with specific biological examples. PMID:25605777

Method of locating underground mines fires

DOEpatents

Laage, Linneas; Pomroy, William

1992-01-01

An improved method of locating an underground mine fire by comparing the pattern of measured combustion product arrival times at detector locations with a real time computer-generated array of simulated patterns. A number of electronic fire detection devices are linked thru telemetry to a control station on the surface. The mine's ventilation is modeled on a digital computer using network analysis software. The time reguired to locate a fire consists of the time required to model the mines' ventilation, generate the arrival time array, scan the array, and to match measured arrival time patterns to the simulated patterns.

Fast electron microscopy via compressive sensing

DOEpatents

Larson, Kurt W; Anderson, Hyrum S; Wheeler, Jason W

2014-12-09

Various technologies described herein pertain to compressive sensing electron microscopy. A compressive sensing electron microscope includes a multi-beam generator and a detector. The multi-beam generator emits a sequence of electron patterns over time. Each of the electron patterns can include a plurality of electron beams, where the plurality of electron beams is configured to impart a spatially varying electron density on a sample. Further, the spatially varying electron density varies between each of the electron patterns in the sequence. Moreover, the detector collects signals respectively corresponding to interactions between the sample and each of the electron patterns in the sequence.

Apparatus, Method, and Computer Program for a Resolution-Enhanced Pseudo-Noise Code Technique

NASA Technical Reports Server (NTRS)

Li, Steven X. (Inventor)

2015-01-01

An apparatus, method, and computer program for a resolution enhanced pseudo-noise coding technique for 3D imaging is provided. In one embodiment, a pattern generator may generate a plurality of unique patterns for a return to zero signal. A plurality of laser diodes may be configured such that each laser diode transmits the return to zero signal to an object. Each of the return to zero signal includes one unique pattern from the plurality of unique patterns to distinguish each of the transmitted return to zero signals from one another.

Uppermost synchronized generators of spike-wave activity are localized in limbic cortical areas in late-onset absence status epilepticus.

PubMed

Piros, Palma; Puskas, Szilvia; Emri, Miklos; Opposits, Gabor; Spisak, Tamas; Fekete, Istvan; Clemens, Bela

2014-03-01

Absence status (AS) epilepticus with generalized spike-wave pattern is frequently found in severely ill patients in whom several disease states co-exist. The cortical generators of the ictal EEG pattern and EEG functional connectivity (EEGfC) of this condition are unknown. The present study investigated the localization of the uppermost synchronized generators of spike-wave activity in AS. Seven patients with late-onset AS were investigated by EEG spectral analysis, LORETA (Low Resolution Electromagnetic Tomography) source imaging, and LSC (LORETA Source Correlation) analysis, which estimates cortico-cortical EEGfC among 23 ROIs (regions of interest) in each hemisphere. All the patients showed generalized ictal EEG activity. Maximum Z-scored spectral power was found in the 1-6 Hz and 12-14 Hz frequency bands. LORETA showed that the uppermost synchronized generators of 1-6 Hz band activity were localized in frontal and temporal cortical areas that are parts of the limbic system. For the 12-14 Hz band, abnormally synchronized generators were found in the antero-medial frontal cortex. Unlike the rather stereotyped spectral and LORETA findings, the individual EEGfC patterns were very dissimilar. The findings are discussed in the context of nonconvulsive seizure types and the role of the underlying cortical areas in late-onset AS. The diversity of the EEGfC patterns remains an enigma. Localizing the cortical generators of the EEG patterns contributes to understanding the neurophysiology of the condition. Copyright © 2013 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Generation of fluoroscopic 3D images with a respiratory motion model based on an external surrogate signal

NASA Astrophysics Data System (ADS)

Hurwitz, Martina; Williams, Christopher L.; Mishra, Pankaj; Rottmann, Joerg; Dhou, Salam; Wagar, Matthew; Mannarino, Edward G.; Mak, Raymond H.; Lewis, John H.

2015-01-01

Respiratory motion during radiotherapy can cause uncertainties in definition of the target volume and in estimation of the dose delivered to the target and healthy tissue. In this paper, we generate volumetric images of the internal patient anatomy during treatment using only the motion of a surrogate signal. Pre-treatment four-dimensional CT imaging is used to create a patient-specific model correlating internal respiratory motion with the trajectory of an external surrogate placed on the chest. The performance of this model is assessed with digital and physical phantoms reproducing measured irregular patient breathing patterns. Ten patient breathing patterns are incorporated in a digital phantom. For each patient breathing pattern, the model is used to generate images over the course of thirty seconds. The tumor position predicted by the model is compared to ground truth information from the digital phantom. Over the ten patient breathing patterns, the average absolute error in the tumor centroid position predicted by the motion model is 1.4 mm. The corresponding error for one patient breathing pattern implemented in an anthropomorphic physical phantom was 0.6 mm. The global voxel intensity error was used to compare the full image to the ground truth and demonstrates good agreement between predicted and true images. The model also generates accurate predictions for breathing patterns with irregular phases or amplitudes.

Statistical model for speckle pattern optimization.

PubMed

Su, Yong; Zhang, Qingchuan; Gao, Zeren

2017-11-27

Image registration is the key technique of optical metrologies such as digital image correlation (DIC), particle image velocimetry (PIV), and speckle metrology. Its performance depends critically on the quality of image pattern, and thus pattern optimization attracts extensive attention. In this article, a statistical model is built to optimize speckle patterns that are composed of randomly positioned speckles. It is found that the process of speckle pattern generation is essentially a filtered Poisson process. The dependence of measurement errors (including systematic errors, random errors, and overall errors) upon speckle pattern generation parameters is characterized analytically. By minimizing the errors, formulas of the optimal speckle radius are presented. Although the primary motivation is from the field of DIC, we believed that scholars in other optical measurement communities, such as PIV and speckle metrology, will benefit from these discussions.

Mining continuous activity patterns from animal trajectory data

USGS Publications Warehouse

Wang, Y.; Luo, Ze; Baoping, Yan; Takekawa, John Y.; Prosser, Diann J.; Newman, Scott H.

2014-01-01

The increasing availability of animal tracking data brings us opportunities and challenges to intuitively understand the mechanisms of animal activities. In this paper, we aim to discover animal movement patterns from animal trajectory data. In particular, we propose a notion of continuous activity pattern as the concise representation of underlying similar spatio-temporal movements, and develop an extension and refinement framework to discover the patterns. We first preprocess the trajectories into significant semantic locations with time property. Then, we apply a projection-based approach to generate candidate patterns and refine them to generate true patterns. A sequence graph structure and a simple and effective processing strategy is further developed to reduce the computational overhead. The proposed approaches are extensively validated on both real GPS datasets and large synthetic datasets.

Implementation of pattern generation algorithm in forming Gilmore and Gomory model for two dimensional cutting stock problem

NASA Astrophysics Data System (ADS)

Octarina, Sisca; Radiana, Mutia; Bangun, Putra B. J.

2018-01-01

Two dimensional cutting stock problem (CSP) is a problem in determining the cutting pattern from a set of stock with standard length and width to fulfill the demand of items. Cutting patterns were determined in order to minimize the usage of stock. This research implemented pattern generation algorithm to formulate Gilmore and Gomory model of two dimensional CSP. The constraints of Gilmore and Gomory model was performed to assure the strips which cut in the first stage will be used in the second stage. Branch and Cut method was used to obtain the optimal solution. Based on the results, it found many patterns combination, if the optimal cutting patterns which correspond to the first stage were combined with the second stage.

rasbhari: Optimizing Spaced Seeds for Database Searching, Read Mapping and Alignment-Free Sequence Comparison.

PubMed

Hahn, Lars; Leimeister, Chris-André; Ounit, Rachid; Lonardi, Stefano; Morgenstern, Burkhard

2016-10-01

Many algorithms for sequence analysis rely on word matching or word statistics. Often, these approaches can be improved if binary patterns representing match and don't-care positions are used as a filter, such that only those positions of words are considered that correspond to the match positions of the patterns. The performance of these approaches, however, depends on the underlying patterns. Herein, we show that the overlap complexity of a pattern set that was introduced by Ilie and Ilie is closely related to the variance of the number of matches between two evolutionarily related sequences with respect to this pattern set. We propose a modified hill-climbing algorithm to optimize pattern sets for database searching, read mapping and alignment-free sequence comparison of nucleic-acid sequences; our implementation of this algorithm is called rasbhari. Depending on the application at hand, rasbhari can either minimize the overlap complexity of pattern sets, maximize their sensitivity in database searching or minimize the variance of the number of pattern-based matches in alignment-free sequence comparison. We show that, for database searching, rasbhari generates pattern sets with slightly higher sensitivity than existing approaches. In our Spaced Words approach to alignment-free sequence comparison, pattern sets calculated with rasbhari led to more accurate estimates of phylogenetic distances than the randomly generated pattern sets that we previously used. Finally, we used rasbhari to generate patterns for short read classification with CLARK-S. Here too, the sensitivity of the results could be improved, compared to the default patterns of the program. We integrated rasbhari into Spaced Words; the source code of rasbhari is freely available at http://rasbhari.gobics.de/.

Effects of ion channel noise on neural circuits: an application to the respiratory pattern generator to investigate breathing variability.

PubMed

Yu, Haitao; Dhingra, Rishi R; Dick, Thomas E; Galán, Roberto F

2017-01-01

Neural activity generally displays irregular firing patterns even in circuits with apparently regular outputs, such as motor pattern generators, in which the output frequency fluctuates randomly around a mean value. This "circuit noise" is inherited from the random firing of single neurons, which emerges from stochastic ion channel gating (channel noise), spontaneous neurotransmitter release, and its diffusion and binding to synaptic receptors. Here we demonstrate how to expand conductance-based network models that are originally deterministic to include realistic, physiological noise, focusing on stochastic ion channel gating. We illustrate this procedure with a well-established conductance-based model of the respiratory pattern generator, which allows us to investigate how channel noise affects neural dynamics at the circuit level and, in particular, to understand the relationship between the respiratory pattern and its breath-to-breath variability. We show that as the channel number increases, the duration of inspiration and expiration varies, and so does the coefficient of variation of the breath-to-breath interval, which attains a minimum when the mean duration of expiration slightly exceeds that of inspiration. For small channel numbers, the variability of the expiratory phase dominates over that of the inspiratory phase, and vice versa for large channel numbers. Among the four different cell types in the respiratory pattern generator, pacemaker cells exhibit the highest sensitivity to channel noise. The model shows that suppressing input from the pons leads to longer inspiratory phases, a reduction in breathing frequency, and larger breath-to-breath variability, whereas enhanced input from the raphe nucleus increases breathing frequency without changing its pattern. A major source of noise in neuronal circuits is the "flickering" of ion currents passing through the neurons' membranes (channel noise), which cannot be suppressed experimentally. Computational simulations are therefore the best way to investigate the effects of this physiological noise by manipulating its level at will. We investigate the role of noise in the respiratory pattern generator and show that endogenous, breath-to-breath variability is tightly linked to the respiratory pattern. Copyright © 2017 the American Physiological Society.

Dorsal and ventral aspects of the most caudal medullary reticular formation have differential roles in modulation and formation of the respiratory motor pattern in rat.

PubMed

Jones, Sarah E; Stanić, Davor; Dutschmann, Mathias

2016-12-01

The respiratory pattern generator of mammals is anatomically organized in lateral respiratory columns (LRCs) within the brainstem. LRC compartments serve specific functions in respiratory pattern and rhythm generation. While the caudal medullary reticular formation (cMRF) has respiratory functions reportedly related to the mediation of expulsive respiratory reflexes, it remains unclear whether neurons of the cMRF functionally belong to the LRC. In the present study we specifically investigated the respiratory functions of the cMRF. Tract tracing shows that the cMRF has substantial connectivity with key compartments of the LRC, particularly the parafacial respiratory group and the Kölliker-Fuse nuclei. These neurons have a loose topography and are located in the ventral and dorsal cMRF. Systematic mapping of the cMRF with glutamate stimulation revealed potent respiratory modulation of the respiratory motor pattern from both dorsal and ventral injection sites. Pharmacological inhibition of the cMRF with the GABA-receptor agonist isoguvacine produced significant and robust changes to the baseline respiratory motor pattern (decreased laryngeal post-inspiratory and abdominal expiratory motor activity, delayed inspiratory off-switch and increased respiratory frequency) after dorsal cMRF injection, while ventral injections had no effect. The present data indicate that the ventral cMRF is not an integral part of the respiratory pattern generator and merely serves as a relay for sensory and/or higher command-related modulation of respiration. On the contrary, the dorsal aspect of the cMRF clearly has a functional role in respiratory pattern formation. These findings revive the largely abandoned concept of a dorsal respiratory group that contributes to the generation of the respiratory motor pattern.

Neural Sequence Generation Using Spatiotemporal Patterns of Inhibition.

PubMed

Cannon, Jonathan; Kopell, Nancy; Gardner, Timothy; Markowitz, Jeffrey

2015-11-01

Stereotyped sequences of neural activity are thought to underlie reproducible behaviors and cognitive processes ranging from memory recall to arm movement. One of the most prominent theoretical models of neural sequence generation is the synfire chain, in which pulses of synchronized spiking activity propagate robustly along a chain of cells connected by highly redundant feedforward excitation. But recent experimental observations in the avian song production pathway during song generation have shown excitatory activity interacting strongly with the firing patterns of inhibitory neurons, suggesting a process of sequence generation more complex than feedforward excitation. Here we propose a model of sequence generation inspired by these observations in which a pulse travels along a spatially recurrent excitatory chain, passing repeatedly through zones of local feedback inhibition. In this model, synchrony and robust timing are maintained not through redundant excitatory connections, but rather through the interaction between the pulse and the spatiotemporal pattern of inhibition that it creates as it circulates the network. These results suggest that spatially and temporally structured inhibition may play a key role in sequence generation.

Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites.

PubMed

González Pericot, N; Villoria Sáez, P; Del Río Merino, M; Liébana Carrasco, O

2014-11-01

The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites. Copyright © 2014 Elsevier Ltd. All rights reserved.

Probing Atomic Dynamics and Structures Using Optical Patterns

NASA Astrophysics Data System (ADS)

Schmittberger, Bonnie L.; Gauthier, Daniel J.

2015-05-01

Pattern formation is a widely studied phenomenon that can provide fundamental insights into nonlinear systems. Emergent patterns in cold atoms are of particular interest in condensed matter physics and quantum information science because one can relate optical patterns to spatial structures in the atoms. In our experimental system, we study multimode optical patterns generated from a sample of cold, thermal atoms. We observe this nonlinear optical phenomenon at record low input powers due to the highly nonlinear nature of the spatial bunching of atoms in an optical lattice. We present a detailed study of the dynamics of these bunched atoms during optical pattern formation. We show how small changes in the atomic density distribution affect the symmetry of the generated patterns as well as the nature of the nonlinearity that describes the light-atom interaction. We gratefully acknowledge the financial support of the National Science Foundation through Grant #PHY-1206040.

The Development of Group Interaction Patterns: How Groups become Adaptive, Generative, and Transformative Learners

ERIC Educational Resources Information Center

London, Manuel; Sessa, Valerie I.

2007-01-01

This article integrates the literature on group interaction process analysis and group learning, providing a framework for understanding how patterns of interaction develop. The model proposes how adaptive, generative, and transformative learning processes evolve and vary in their functionality. Environmental triggers for learning, the group's…

Demonstration of Numerical Equivalence of Ensemble and Spectral Averaging in Electromagnetic Scattering by Random Particulate Media

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Dlugach, Janna M.; Zakharova, Nadezhda T.

2016-01-01

The numerically exact superposition T-matrix method is used to model far-field electromagnetic scattering by two types of particulate object. Object 1 is a fixed configuration which consists of N identical spherical particles (with N 200 or 400) quasi-randomly populating a spherical volume V having a median size parameter of 50. Object 2 is a true discrete random medium (DRM) comprising the same number N of particles randomly moving throughout V. The median particle size parameter is fixed at 4. We show that if Object 1 is illuminated by a quasi-monochromatic parallel beam then it generates a typical speckle pattern having no resemblance to the scattering pattern generated by Object 2. However, if Object 1 is illuminated by a parallel polychromatic beam with a 10 bandwidth then it generates a scattering pattern that is largely devoid of speckles and closely reproduces the quasi-monochromatic pattern generated by Object 2. This result serves to illustrate the capacity of the concept of electromagnetic scattering by a DRM to encompass fixed quasi-random particulate samples provided that they are illuminated by polychromatic light.

Towards multifocal ultrasonic neural stimulation: pattern generation algorithms

NASA Astrophysics Data System (ADS)

Hertzberg, Yoni; Naor, Omer; Volovick, Alexander; Shoham, Shy

2010-10-01

Focused ultrasound (FUS) waves directed onto neural structures have been shown to dynamically modulate neural activity and excitability, opening up a range of possible systems and applications where the non-invasiveness, safety, mm-range resolution and other characteristics of FUS are advantageous. As in other neuro-stimulation and modulation modalities, the highly distributed and parallel nature of neural systems and neural information processing call for the development of appropriately patterned stimulation strategies which could simultaneously address multiple sites in flexible patterns. Here, we study the generation of sparse multi-focal ultrasonic distributions using phase-only modulation in ultrasonic phased arrays. We analyse the relative performance of an existing algorithm for generating multifocal ultrasonic distributions and new algorithms that we adapt from the field of optical digital holography, and find that generally the weighted Gerchberg-Saxton algorithm leads to overall superior efficiency and uniformity in the focal spots, without significantly increasing the computational burden. By combining phased-array FUS and magnetic-resonance thermometry we experimentally demonstrate the simultaneous generation of tightly focused multifocal distributions in a tissue phantom, a first step towards patterned FUS neuro-modulation systems and devices.

Novel layered clustering-based approach for generating ensemble of classifiers.

PubMed

Rahman, Ashfaqur; Verma, Brijesh

2011-05-01

This paper introduces a novel concept for creating an ensemble of classifiers. The concept is based on generating an ensemble of classifiers through clustering of data at multiple layers. The ensemble classifier model generates a set of alternative clustering of a dataset at different layers by randomly initializing the clustering parameters and trains a set of base classifiers on the patterns at different clusters in different layers. A test pattern is classified by first finding the appropriate cluster at each layer and then using the corresponding base classifier. The decisions obtained at different layers are fused into a final verdict using majority voting. As the base classifiers are trained on overlapping patterns at different layers, the proposed approach achieves diversity among the individual classifiers. Identification of difficult-to-classify patterns through clustering as well as achievement of diversity through layering leads to better classification results as evidenced from the experimental results.

Wide-field depth-sectioning fluorescence microscopy using projector-generated patterned illumination

NASA Astrophysics Data System (ADS)

Delica, Serafin; Mar Blanca, Carlo

2007-10-01

We present a simple and cost-effective wide-field, depth-sectioning, fluorescence microscope utilizing a commercial multimedia projector to generate excitation patterns on the sample. Highly resolved optical sections of fluorescent pollen grains at 1.9 μm axial resolution are constructed using the structured illumination technique. This requires grid excitation patterns to be scanned across the sample, which is straightforwardly implemented by creating slideshows of gratings at different phases, projecting them onto the sample, and synchronizing camera acquisition with slide transition. In addition to rapid dynamic pattern generation, the projector provides high illumination power and spectral excitation selectivity. We exploit these properties by imaging mouse neural cells in cultures multistained with Alexa 488 and Cy3. The spectral and structural neural information is effectively resolved in three dimensions. The flexibility and commercial availability of this light source is envisioned to open multidimensional imaging to a broader user base.

Neural basis of singing in crickets: central pattern generation in abdominal ganglia

NASA Astrophysics Data System (ADS)

Schöneich, Stefan; Hedwig, Berthold

2011-12-01

The neural mechanisms underlying cricket singing behavior have been the focus of several studies, but the central pattern generator (CPG) for singing has not been localized conclusively. To test if the abdominal ganglia contribute to the singing motor pattern and to analyze if parts of the singing CPG are located in these ganglia, we systematically truncated the abdominal nerve cord of fictively singing crickets while recording the singing motor pattern from a front-wing nerve. Severing the connectives anywhere between terminal ganglion and abdominal ganglion A3 did not preclude singing, although the motor pattern became more variable and failure-prone as more ganglia were disconnected. Singing terminated immediately and permanently after transecting the connectives between the metathoracic ganglion complex and the first unfused abdominal ganglion A3. The contribution of abdominal ganglia for singing pattern generation was confirmed by intracellular interneuron recordings and current injections. During fictive singing, an ascending interneuron with its soma and dendrite in A3 depolarized rhythmically. It spiked 10 ms before the wing-opener activity and hyperpolarized in phase with the wing-closer activity. Depolarizing current injection elicited rhythmic membrane potential oscillations and spike bursts that elicited additional syllables and reliably reset the ongoing chirp rhythm. Our results disclose that the abdominal ganglion A3 is directly involved in generating the singing motor pattern, whereas the more posterior ganglia seem to provide only stabilizing feedback to the CPG circuit. Localizing the singing CPG in the anterior abdominal neuromeres now allows analyzing its circuitry at the level of identified interneurons in subsequent studies.

Cellular basis for singing motor pattern generation in the field cricket (Gryllus bimaculatus DeGeer)

PubMed Central

Schöneich, Stefan; Hedwig, Berthold

2012-01-01

The singing behavior of male crickets allows analyzing a central pattern generator (CPG) that was shaped by sexual selection for reliable production of species-specific communication signals. After localizing the essential ganglia for singing in Gryllus bimaculatus, we now studied the calling song CPG at the cellular level. Fictive singing was initiated by pharmacological brain stimulation. The motor pattern underlying syllables and chirps was recorded as alternating spike bursts of wing-opener and wing-closer motoneurons in a truncated wing nerve; it precisely reflected the natural calling song. During fictive singing, we intracellularly recorded and stained interneurons in thoracic and abdominal ganglia and tested their impact on the song pattern by intracellular current injections. We identified three interneurons of the metathoracic and first unfused abdominal ganglion that rhythmically de- and hyperpolarized in phase with the syllable pattern and spiked strictly before the wing-opener motoneurons. Depolarizing current injection in two of these opener interneurons caused additional rhythmic singing activity, which reliably reset the ongoing chirp rhythm. The closely intermeshing arborizations of the singing interneurons revealed the dorsal midline neuropiles of the metathoracic and three most anterior abdominal neuromeres as the anatomical location of singing pattern generation. In the same neuropiles, we also recorded several closer interneurons that rhythmically hyper- and depolarized in the syllable rhythm and spiked strictly before the wing-closer motoneurons. Some of them received pronounced inhibition at the beginning of each chirp. Hyperpolarizing current injection in the dendrite revealed postinhibitory rebound depolarization as one functional mechanism of central pattern generation in singing crickets. PMID:23170234

Graphene Transistor fabricated by Helium Ion Milling

NASA Astrophysics Data System (ADS)

Zhang, Kaiwen; Zhao, Xiangming; Xu, Xiangfan; Vignesh, Viswanathan; Li, Baowen; Pickard, Daniel; Özyilmaz, Barbaros; Department of Physics, National University of Singapore Team; Department of Electrical; Computer Engineering, National University of Singapore Team; eNanoCore, National University of Singapore Team

2011-03-01

We report the direct patterning of graphene for various nano-device applications. The Helium Ion Microscope (HIM), able to resolve nano-scale features on solid samples with an edge resolution of a mere 0.25 nm, has a number of attributes which make it attractive for the imaging of graphene structures. Even more compelling is the ability to directly modify graphene, through surface sputtering, enabling direct pattern transfer for the fabrication of graphene devices. The integration of the HIM with a vector pattern generator (Nano Pattern Generation System, NPGS), provides the capability to directly pattern graphene into nano-ribbons. We have successfully fabricated sub-100nm graphene nano-ribbon devices on Si/SiO2 substrate. Resistance measurement has been made as a function of temperature.

Importance Sampling of Word Patterns in DNA and Protein Sequences

PubMed Central

Chan, Hock Peng; Chen, Louis H.Y.

2010-01-01

Abstract Monte Carlo methods can provide accurate p-value estimates of word counting test statistics and are easy to implement. They are especially attractive when an asymptotic theory is absent or when either the search sequence or the word pattern is too short for the application of asymptotic formulae. Naive direct Monte Carlo is undesirable for the estimation of small probabilities because the associated rare events of interest are seldom generated. We propose instead efficient importance sampling algorithms that use controlled insertion of the desired word patterns on randomly generated sequences. The implementation is illustrated on word patterns of biological interest: palindromes and inverted repeats, patterns arising from position-specific weight matrices (PSWMs), and co-occurrences of pairs of motifs. PMID:21128856

Network Sampling and Classification:An Investigation of Network Model Representations

PubMed Central

Airoldi, Edoardo M.; Bai, Xue; Carley, Kathleen M.

2011-01-01

Methods for generating a random sample of networks with desired properties are important tools for the analysis of social, biological, and information networks. Algorithm-based approaches to sampling networks have received a great deal of attention in recent literature. Most of these algorithms are based on simple intuitions that associate the full features of connectivity patterns with specific values of only one or two network metrics. Substantive conclusions are crucially dependent on this association holding true. However, the extent to which this simple intuition holds true is not yet known. In this paper, we examine the association between the connectivity patterns that a network sampling algorithm aims to generate and the connectivity patterns of the generated networks, measured by an existing set of popular network metrics. We find that different network sampling algorithms can yield networks with similar connectivity patterns. We also find that the alternative algorithms for the same connectivity pattern can yield networks with different connectivity patterns. We argue that conclusions based on simulated network studies must focus on the full features of the connectivity patterns of a network instead of on the limited set of network metrics for a specific network type. This fact has important implications for network data analysis: for instance, implications related to the way significance is currently assessed. PMID:21666773

Optical Potential Field Mapping System

NASA Technical Reports Server (NTRS)

Reid, Max B. (Inventor)

1996-01-01

The present invention relates to an optical system for creating a potential field map of a bounded two dimensional region containing a goal location and an arbitrary number of obstacles. The potential field mapping system has an imaging device and a processor. Two image writing modes are used by the imaging device, electron deposition and electron depletion. Patterns written in electron deposition mode appear black and expand. Patterns written in electron depletion mode are sharp and appear white. The generated image represents a robot's workspace. The imaging device under processor control then writes a goal location in the work-space using the electron deposition mode. The black image of the goal expands in the workspace. The processor stores the generated images, and uses them to generate a feedback pattern. The feedback pattern is written in the workspace by the imaging device in the electron deposition mode to enhance the expansion of the original goal pattern. After the feedback pattern is written, an obstacle pattern is written by the imaging device in the electron depletion mode to represent the obstacles in the robot's workspace. The processor compares a stored image to a previously stored image to determine a change therebetween. When no change occurs, the processor averages the stored images to produce the potential field map.

Reliable, responsive pacemaking and pattern generation with minimal cell numbers: the crustacean cardiac ganglion.

PubMed

Cooke, Ian M

2002-04-01

Investigations of the electrophysiology of crustacean cardiac ganglia over the last half-century are reviewed for their contributions to elucidating the cellular mechanisms and interactions by which a small (as few as nine cells) neuronal network accomplishes extremely reliable, rhythmical, patterned activation of muscular activity-in this case, beating of the neurogenic heart. This ganglion is thus a model for pacemaking and central pattern generation. Favorable anatomy has permitted voltage- and space-clamp analyses of voltage-dependent ionic currents that endow each neuron with the intrinsic ability to respond with rhythmical, patterned impulse activity to nonpatterned stimulation. The crustacean soma and initial axon segment do not support impulse generation but integrate input from stretch-sensitive dendrites and electrotonic and chemically mediated synapses on axonal processes in neuropils. The soma and initial axon produce a depolarization-activated, calcium-mediated, sustained potential, the "driver potential," so-called because it drives a train of impulses at the "trigger zone" of the axon. Extreme reliability results from redundancy and the electrotonic coupling and synaptic interaction among all the neurons. Complex modulation by central nervous system inputs and by neurohormones to adjust heart pumping to physiological demands has long been demonstrated, but much remains to be learned about the cellular and molecular mechanisms of action. The continuing relevance of the crustacean cardiac ganglion as a relatively simple model for pacemaking and central pattern generation is confirmed by the rapidly widening documentation of intrinsic potentials such as plateau potentials in neurons of all major animal groups. The suite of ionic currents (a slowly inactivating calcium current and various potassium currents, with variations) observed for the crustacean cardiac ganglion have been implicated in or proven to underlie a majority of the intrinsic potentials of neurons involved in pattern generation.

Central pattern generator for vocalization: is there a vertebrate morphotype?

PubMed

Bass, Andrew H

2014-10-01

Animals that generate acoustic signals for social communication are faced with two essential tasks: generate a temporally precise signal and inform the auditory system about the occurrence of one's own sonic signal. Recent studies of sound producing fishes delineate a hindbrain network comprised of anatomically distinct compartments coding equally distinct neurophysiological properties that allow an organism to meet these behavioral demands. A set of neural characters comprising a vocal-sonic central pattern generator (CPG) morphotype is proposed for fishes and tetrapods that shares evolutionary developmental origins with pectoral appendage motor systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Central pattern generator for vocalization: Is there a vertebrate morphotype?

PubMed Central

Bass, Andrew H.

2014-01-01

Animals that generate acoustic signals for social communication are faced with two essential tasks: generate a temporally precise signal and inform the auditory system about the occurrence of one’s own sonic signal. Recent studies of sound producing fishes delineate a hindbrain network comprised of anatomically distinct compartments coding equally distinct neurophysiological properties that allow an organism to meet these behavioral demands. A set of neural characters comprising a vocal-sonic central pattern generator (CPG) morphotype is proposed for fishes and tetrapods that shares evolutionary developmental origins with pectoral appendage motor systems. PMID:25050813

Computer simulation of airflow through a multi-generation tracheobronchial conducting airway

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

Fan, B.; Cheng, Yung-Sung; Yeh, Hsu-Chi

1995-12-01

Knowledge of airflow patterns in the human lung is important for an analysis of lung diseases and drug delivery of aerosolized medicine for medical treatment. However, very little systematic information is available on the pattern of airflow in the lung and on how this pattern affects the deposition of toxicants in the lung, and the efficacy of aerosol drug therapy. Most previous studies have only considered the airflow through a single bifurcating airway. However, the flow in a network of more than one bifurcation is more complicated due to the effect of interrelated lung generations. Because of the variation ofmore » airway geometry and flow condition from generation to generation, a single bifurcating airway cannot be taken as a representative for the others in different generations. The flow in the network varies significantly with airway generations because of a redistribution of axial momentum by the secondary flow motions. The influence of the redistribution of flow is expected in every generation. Therefore, a systematic information of the airflow through a multi-generation tracheobronchial conducting airway is needed, and it becomes the purpose of this study. This study has provided information on airflow in a lung model which is necessary to the study of the deposition of toxicants and therapeutic aerosols.« less

Application of reaction-diffusion models to cell patterning in Xenopus retina. Initiation of patterns and their biological stability.

PubMed

Shoaf, S A; Conway, K; Hunt, R K

1984-08-07

We have examined the behavior of two reaction-diffusion models, originally proposed by Gierer & Meinhardt (1972) and by Kauffman, Shymko & Trabert (1978), for biological pattern formation. Calculations are presented for pattern formation on a disc (approximating the geometry of a number of embryonic anlagen including the frog eye rudiment), emphasizing the sensitivity of patterns to changes in initial conditions and to perturbations in the geometry of the morphogen-producing space. Analysis of the linearized equations from the models enabled us to select appropriate parameters and disc size for pattern growth. A computer-implemented finite element method was used to solve the non-linear model equations reiteratively. For the Gierer-Meinhardt model, initial activation (varying in size over two orders of magnitude) of one point on the disc's edge was sufficient to generate the primary gradient. Various parts of the disc were removed (remaining only as diffusible space) from the morphogen-producing cycle to investigate the effects of cells dropping out of the cycle due to cell death or malfunction (single point removed) or differentiation (center removed), as occur in the Xenopus eye rudiment. The resulting patterns had the same general shape and amplitude as normal gradients. Nor did a two-fold increase in disc size affect the pattern-generating ability of the model. Disc fragments bearing their primary gradient patterns were fused (with gradients in opposite directions, but each parallel to the fusion line). The resulting patterns generated by the model showed many similarities to results of "compound eye" experiments in Xenopus. Similar patterns were obtained with the model of Kauffman's group (1978), but we found less stability of the pattern subject to simulations of central differentiation. However, removal of a single point from the morphogen cycle (cell death) did not result in any change. The sensitivity of the Kauffman et al. model to shape perturbations is not surprising since the model was originally designed to use shape and increasing size during growth to generate a sequence of transient patterns. However, the Gierer-Meinhardt model is remarkably stable even when subjected to a wide range of perturbations in the diffusible space, thus allowing it to cope with normal biological variability, and offering an exciting range of possibilities for reaction-diffusion models as mechanisms underlying the spatial patterns of tissue structures.

Self-interferometric technique for visualization of phase patterns encoded onto a liquid-crystal display

NASA Astrophysics Data System (ADS)

Bentley, Joel B.; Davis, Jeffrey A.; Albero, Jorge; Moreno, Ignacio

2006-10-01

We report a new self-interferometric technique for visualizing phase patterns that are encoded onto a phase-only liquid-crystal display (LCD). In our approach, the LCD generates both the desired object beam as well as the reference beam. Normally the phase patterns are encoded with a phase depth of 2π radians, and all of the incident energy is diffracted into the first-order beam. However, by reducing this phase depth, we can generate an additional zero-order diffracted beam, which acts as the reference beam. We work at distances such that these two patterns spatially interfere, producing an interference pattern that displays the encoded phase pattern. This approach was used recently to display the phase vortices of helical Ince-Gaussian beams. Here we show additional experimental results and analyze the process.

A new method for discovering behavior patterns among animal movements

USGS Publications Warehouse

Wang, Y.; Luo, Ze; Takekawa, John Y.; Prosser, Diann J.; Xiong, Y.; Newman, S.; Xiao, X.; Batbayar, N.; Spragens, Kyle A.; Balachandran, S.; Yan, B.

2016-01-01

Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets.

A new method for discovering behavior patterns among animal movements.

PubMed

Wang, Yuwei; Luo, Ze; Takekawa, John; Prosser, Diann; Xiong, Yan; Newman, Scott; Xiao, Xiangming; Batbayar, Nyambayar; Spragens, Kyle; Balachandran, Sivananinthaperumal; Yan, Baoping

Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets.

A new method for discovering behavior patterns among animal movements

PubMed Central

Wang, Yuwei; Luo, Ze; Takekawa, John; Prosser, Diann; Xiong, Yan; Newman, Scott; Xiao, Xiangming; Batbayar, Nyambayar; Spragens, Kyle; Balachandran, Sivananinthaperumal; Yan, Baoping

2016-01-01

Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets. PMID:27217810

Neuromorphic walking gait control.

PubMed

Still, Susanne; Hepp, Klaus; Douglas, Rodney J

2006-03-01

We present a neuromorphic pattern generator for controlling the walking gaits of four-legged robots which is inspired by central pattern generators found in the nervous system and which is implemented as a very large scale integrated (VLSI) chip. The chip contains oscillator circuits that mimic the output of motor neurons in a strongly simplified way. We show that four coupled oscillators can produce rhythmic patterns with phase relationships that are appropriate to generate all four-legged animal walking gaits. These phase relationships together with frequency and duty cycle of the oscillators determine the walking behavior of a robot driven by the chip, and they depend on a small set of stationary bias voltages. We give analytic expressions for these dependencies. This chip reduces the complex, dynamic inter-leg control problem associated with walking gait generation to the problem of setting a few stationary parameters. It provides a compact and low power solution for walking gait control in robots.

Angiographic patterns of restenosis with 2nd generation drug-eluting stent: comparative analysis from a 10-year single-center experience .

PubMed

Lee, Sahmin; Yoon, Chang-Hwan; Oh, Il-Young; Suh, Jung-Won; Cho, Young-Seok; Cho, Goo-Yeong; Chae, In-Ho; Choi, Dong-Ju; Youn, Tae-Jin

2015-01-01

The angiographic features of restenosis contain prognostic information. However, restenosis patterns of the new generation drug-eluting stents (DES), everolimus-(EES) and resolute zotarolimus-eluting stent (ZES) have not been described.A total of 210 consecutive patients with DES restenosis were enrolled from 2003 to 2012. We analyzed 217 restenotic lesions after DES implantation, and compared the morphologic characteristics of the 2nd generation DES restenosis to those of restenosis with 2 first generation DES, sirolimus-(SES) and paclitaxel-eluting stent (PES).Baseline characteristics were comparable between the different stent groups. The incidence of focal restenosis was significantly lower for PES than the other stents (49.5% versus 87.0%, 76.2%, and 82.1% for PES versus SES, EES, and ZES, respectively, P < 0.001). When considering the pattern of restenosis solely within the stent margins, a further clear distinction between PES and other stents was observed (40.0% versus 92.9%, 88.9%, and 81.2% in PES versus SES, EES, and ZES, respectively, P < 0.001). There were no significant differences in restenosis patterns among SES, EES, and ZES. In multivariate analysis, PES implantation, hypertension, and age were associated with non-focal type of restenosis after DES implantation. After the introduction of EES and ZES into routine clinical practice in 2008, focal restenosis significantly increased from 63.9% to 76.7% and diffuse restenosis significantly decreased from 26.4% to 11.0% (P = 0.045).Focal restenosis was the most common pattern of restenosis in the new generation DES and the incidence of diffuse restenosis significantly decreased with the introduction of the 2nd generation DES.

A two-step patterning process increases the robustness of periodic patterning in the fly eye.

PubMed

Gavish, Avishai; Barkai, Naama

2016-06-01

Complex periodic patterns can self-organize through dynamic interactions between diffusible activators and inhibitors. In the biological context, self-organized patterning is challenged by spatial heterogeneities ('noise') inherent to biological systems. How spatial variability impacts the periodic patterning mechanism and how it can be buffered to ensure precise patterning is not well understood. We examine the effect of spatial heterogeneity on the periodic patterning of the fruit fly eye, an organ composed of ∼800 miniature eye units (ommatidia) whose periodic arrangement along a hexagonal lattice self-organizes during early stages of fly development. The patterning follows a two-step process, with an initial formation of evenly spaced clusters of ∼10 cells followed by a subsequent refinement of each cluster into a single selected cell. Using a probabilistic approach, we calculate the rate of patterning errors resulting from spatial heterogeneities in cell size, position and biosynthetic capacity. Notably, error rates were largely independent of the desired cluster size but followed the distributions of signaling speeds. Pre-formation of large clusters therefore greatly increases the reproducibility of the overall periodic arrangement, suggesting that the two-stage patterning process functions to guard the pattern against errors caused by spatial heterogeneities. Our results emphasize the constraints imposed on self-organized patterning mechanisms by the need to buffer stochastic effects. Author summary Complex periodic patterns are common in nature and are observed in physical, chemical and biological systems. Understanding how these patterns are generated in a precise manner is a key challenge. Biological patterns are especially intriguing, as they are generated in a noisy environment; cell position and cell size, for example, are subject to stochastic variations, as are the strengths of the chemical signals mediating cell-to-cell communication. The need to generate a precise and robust pattern in this 'noisy' environment restricts the space of patterning mechanisms that can function in the biological setting. Mathematical modeling is useful in comparing the sensitivity of different mechanisms to such variations, thereby highlighting key aspects of their design.We use mathematical modeling to study the periodic patterning of the fruit fly eye. In this system, a highly ordered lattice of differentiated cells is generated in a two-dimensional cell epithelium. The pattern is first observed by the appearance of evenly spaced clusters of ∼10 cells that express specific genes. Each cluster is subsequently refined into a single cell, which initiates the formation and differentiation of a miniature eye unit, the ommatidium. We formulate a mathematical model based on the known molecular properties of the patterning mechanism, and use a probabilistic approach to calculate the errors in cluster formation and refinement resulting from stochastic cell-to-cell variations ('noise') in different quantitative parameters. This enables us to define the parameters most influencing noise sensitivity. Notably, we find that this error is roughly independent of the desired cluster size, suggesting that large clusters are beneficial for ensuring the overall reproducibility of the periodic cluster arrangement. For the stage of cluster refinement, we find that rapid communication between cells is critical for reducing error. Our work provides new insights into the constraints imposed on mechanisms generating periodic patterning in a realistic, noisy environment, and in particular, discusses the different considerations in achieving optimal design of the patterning network.

Sequence data for two large-subunit rRNA genes from an Asian strain of Alexandrium catenella.

PubMed Central

Yeung, P K; Kong, K F; Wong, F T; Wong, J T

1996-01-01

PCR generated two distinct products from a toxic isolate of Alexandrium catenella, which had been taken from Dai Ya Bay (southern China), by using primers for large-subunit rRNA. This pattern is distinct from published data for North American Alexandrium species. Sequences of the two products suggest that the smaller was generated by a deletion event. Single-cell PCR generated the same pattern, confirming that the two products were not the results from different individuals. PMID:8900010

Sequential patterns of essential trace elements composition in Gracilaria verrucosa and its generated products

NASA Astrophysics Data System (ADS)

Izzati, Munifatul; Haryanti, Sri; Parman, Sarjana

2018-05-01

Gracilaria widely known as a source of essential trace elements. However this red seaweeds also has great potential for being developed into commercial products. This study examined the sequential pattern of essential trace elements composition in fresh Gracilaria verrucosa and a selection of its generated products, nemely extracted agar, Gracilaria salt and Gracilaria residue. The sample was collected from a brackish water pond, located in north part Semarang, Central Java. The collected sample was then dried under the sun, and subsequently processed into aformentioned generated products. The Gracilaria salt was obtain by soaking the sun dried Gracilaria overnight in fresh water overnight. The resulted salt solution was then boiled leaving crystal salt. Extracted agar was obtained with alkali agar extraction method. The rest of remaining material was considered as Gracilaria residue. The entire process was repeated 3 times. The compositin of trace elements was examined using ICP-MS Spectrometry. Collected data was then analyzed by ANOVA single factor. Resulting sequential pattern of its essential trace elements composition was compared. A regular table salt was used as controls. Resuts from this study revealed that Gracilaria verrucosa and its all generated products all have similarly patterned the composition of essential trace elements, where Mn>Zn>Cu>Mo. Additionally this pattern is similar to different subspecies of Gracilaria from different location and and different season. However, Gracilaria salt has distinctly different pattern of sequential essential trace elements composition compared to table salt.

Diagnostic Hypothesis Generation and Human Judgment

ERIC Educational Resources Information Center

Thomas, Rick P.; Dougherty, Michael R.; Sprenger, Amber M.; Harbison, J. Isaiah

2008-01-01

Diagnostic hypothesis-generation processes are ubiquitous in human reasoning. For example, clinicians generate disease hypotheses to explain symptoms and help guide treatment, auditors generate hypotheses for identifying sources of accounting errors, and laypeople generate hypotheses to explain patterns of information (i.e., data) in the…

Influence of Maternal Work Patterns and Socioeconomic Status on Gen Y Lifestyle Choice

ERIC Educational Resources Information Center

Bosco, Susan M.; Bianco, Candy A.

2005-01-01

This article examines the lifestyle balance between career and family desired by the next generation of workers and whether these desires have been influenced by socioeconomic variables and maternal work patterns. The individuals who will enter the workforce in the next several years are the first generation in which most mothers worked outside…

Laser fresnel distance measuring system and method

NASA Technical Reports Server (NTRS)

Campbell, Jonathan W. (Inventor); Lehner, David L. (Inventor); Smalley, Larry L. (Inventor); Smith, legal representative, Molly C. (Inventor); Sanders, Alvin J. (Inventor); Earl, Dennis Duncan (Inventor); Allison, Stephen W. (Inventor); Smith, Kelly L. (Inventor)

2008-01-01

A method and system for determining range to a target are provided. A beam of electromagnetic energy is transmitted through an aperture in an opaque screen such that a portion of the beam passes through the aperture to generate a region of diffraction that varies as a function of distance from the aperture. An imaging system is focused on a target plane in the region of diffraction with the generated image being compared to known diffraction patterns. Each known diffraction pattern has a unique value associated therewith that is indicative of a distance from the aperture. A match between the generated image and at least one of the known diffraction patterns is indicative of a distance between the aperture and target plane.

Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites

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

González Pericot, N., E-mail: natalia.gpericot@upm.es; Villoria Sáez, P., E-mail: paola.villoria@upm.es; Del Río Merino, M., E-mail: mercedes.delrio@upm.es

2014-11-15

Highlights: • On-site segregation level: 1.80%; training and motivation strategies were not effective. • 70% Cardboard waste: from switches and sockets during the building services stage. • 40% Plastic waste: generated during structures and partition works due to palletizing. • >50% Wood packaging waste, basically pallets, generated during the envelope works. - Abstract: The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste hasmore » been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites.« less

Cytokinin signalling inhibitory fields provide robustness to phyllotaxis

NASA Astrophysics Data System (ADS)

Besnard, Fabrice; Refahi, Yassin; Morin, Valérie; Marteaux, Benjamin; Brunoud, Géraldine; Chambrier, Pierre; Rozier, Frédérique; Mirabet, Vincent; Legrand, Jonathan; Lainé, Stéphanie; Thévenon, Emmanuel; Farcot, Etienne; Cellier, Coralie; Das, Pradeep; Bishopp, Anthony; Dumas, Renaud; Parcy, François; Helariutta, Ykä; Boudaoud, Arezki; Godin, Christophe; Traas, Jan; Guédon, Yann; Vernoux, Teva

2014-01-01

How biological systems generate reproducible patterns with high precision is a central question in science. The shoot apical meristem (SAM), a specialized tissue producing plant aerial organs, is a developmental system of choice to address this question. Organs are periodically initiated at the SAM at specific spatial positions and this spatiotemporal pattern defines phyllotaxis. Accumulation of the plant hormone auxin triggers organ initiation, whereas auxin depletion around organs generates inhibitory fields that are thought to be sufficient to maintain these patterns and their dynamics. Here we show that another type of hormone-based inhibitory fields, generated directly downstream of auxin by intercellular movement of the cytokinin signalling inhibitor ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 6 (AHP6), is involved in regulating phyllotactic patterns. We demonstrate that AHP6-based fields establish patterns of cytokinin signalling in the meristem that contribute to the robustness of phyllotaxis by imposing a temporal sequence on organ initiation. Our findings indicate that not one but two distinct hormone-based fields may be required for achieving temporal precision during formation of reiterative structures at the SAM, thus indicating an original mechanism for providing robustness to a dynamic developmental system.

Comparing patterns and predictors of immigrant offending among a sample of adjudicated youth.

PubMed

Bersani, Bianca E; Loughran, Thomas A; Piquero, Alex R

2014-11-01

Research on immigration and crime has only recently started to consider potential heterogeneity in longitudinal patterns of immigrant offending. Guided by segmented assimilation and life course criminology frameworks, this article advances prior research on the immigration-crime nexus in three ways: using a large sample of high-risk adjudicated youth containing first and second generation immigrants; examining longitudinal trajectories of official and self-reported offending; and merging segmented assimilation and life course theories to distinguish between offending patterns. Data come from the Pathways to Desistance study containing detailed offending and socio-demographic background information on 1,354 adolescents (13.6 % female; n = 1,061 native-born; n = 210 second generation immigrants; n = 83 first generation immigrants) as they transition to young adulthood (aged 14-17 at baseline). Over 84 months we observe whether patterns of offending, and the correlates that may distinguish them, operate differently across immigrant generations. Collectively, this study offers the first investigation of whether immigrants, conditioned on being adjudicated, are characterized by persistent offending. Results show that first generation immigrants are less likely to be involved in serious offending and to evidence persistence in offending, and appear to be on a path toward desistance much more quickly than their peers. Further, assimilation and neighborhood disadvantage operate in unique ways across generational status and relate to different offending styles. The findings show that the risk for persistent offending is greatest among those with high levels of assimilation who reside in disadvantaged contexts, particularly among the second generation youth in the sample.

Characteristics of tuberculosis patients who generate secondary cases.

PubMed

Rodrigo, T; Caylà, J A; García de Olalla, P; Galdós-Tangüis, H; Jansà, J M; Miranda, P; Brugal, T

1997-08-01

To determine the characteristics of smear positive tuberculosis (TB) patients who generate secondary TB cases. Those smear positive TB patients detected by the Barcelona Tuberculosis Program between 1990-1993, and for whom contact studies had been performed, were studied. We analyzed the predictive role of the variables: age, sex, intravenous drug use (IVDU), the presence of the acquired immune deficiency syndrome (AIDS), human immunodeficiency virus (HIV) infection, radiology pattern, district of residence, history of imprisonment, alcoholism, smoking, history of TB, treatment compliance and the number of secondary cases generated. Statistical analysis was based on the logistic regression model, calculating the odds ratios (OR) with 95% confidence intervals (CI). Of the 1079 patients studied, 78 (7.2%) had generated only one secondary case, and 30 (2.8%) two or more. The variables associated with generating two or more secondary cases were: IVDU (P < 0.001; OR = 4.06; CI: 1.80-9.15), cavitary radiology pattern (P = 0.002; OR = 3.69; CI: 1.62-8.43), and age (P = 0.016; OR = 0.98; CI: 0.96-0.99). When we examined those who had generated one or more secondary cases, the following variables were significant: IVDU (P = 0.043; OR = 1.75; CI: 1.02-3.02), cavitary radiology pattern (P < 0.001; OR = 3.07; CI: 1.98-4.77) and age (P < 0.001; OR = 0.98; CI: 0.97-0.99). The study of the contacts of smear positive TB patients allows us to detect an important number of secondary cases. Young adults, those with cavitary radiology pattern, and IVDU are more likely to generate secondary cases.

A new mechanism for spatial pattern formation via lateral and protrusion-mediated lateral signalling

PubMed Central

Hunter, Ginger L.; Baum, Buzz

2016-01-01

Tissue organization and patterning are critical during development when genetically identical cells take on different fates. Lateral signalling plays an important role in this process by helping to generate self-organized spatial patterns in an otherwise uniform collection of cells. Recent data suggest that lateral signalling can be mediated both by junctional contacts between neighbouring cells and via cellular protrusions that allow non-neighbouring cells to interact with one another at a distance. However, it remains unclear precisely how signalling mediated by these distinct types of cell–cell contact can physically contribute to the generation of complex patterns without the assistance of diffusible morphogens or pre-patterns. To explore this question, in this work we develop a model of lateral signalling based on a single receptor/ligand pair as exemplified by Notch and Delta. We show that allowing the signalling kinetics to differ at junctional versus protrusion-mediated contacts, an assumption inspired by recent data which show that the cleavage of Notch in several systems requires both Delta binding and the application of mechanical force, permits individual cells to act to promote both lateral activation and lateral inhibition. Strikingly, under this model, in which Delta can sequester Notch, a variety of patterns resembling those typical of reaction–diffusion systems is observed, together with more unusual patterns that arise when we consider changes in signalling kinetics, and in the length and distribution of protrusions. Importantly, these patterns are self-organizing—so that local interactions drive tissue-scale patterning. Together, these data show that protrusions can, in principle, generate different types of patterns in addition to contributing to long-range signalling and to pattern refinement. PMID:27807273

Transgenerational effects of adolescent nicotine exposure in rats: Evidence for cognitive deficits in adult female offspring.

PubMed

Renaud, Samantha M; Fountain, Stephen B

2016-01-01

This study investigated whether adolescent nicotine exposure in one generation of rats would impair the cognitive capacity of a subsequent generation. Male and female rats in the parental F0 generation were given twice-daily i.p. injections of either 1.0mg/kg nicotine or an equivalent volume of saline for 35days during adolescence on postnatal days 25-59 (P25-59). After reaching adulthood, male and female nicotine-exposed rats were paired for breeding as were male and female saline control rats. Only female offspring were used in this experiment. Half of the offspring of F0 nicotine-exposed breeders and half of the offspring of F0 saline control rats received twice-daily i.p. injections of 1.0mg/kg nicotine during adolescence on P25-59. The remainder of the rats received twice-daily saline injections for the same period. To evaluate transgenerational effects of nicotine exposure on complex cognitive learning abilities, F1 generation rats were trained to perform a highly structured serial pattern in a serial multiple choice (SMC) task. Beginning on P95, rats in the F1 generation were given either 4days of massed training (20patterns/day) followed by spaced training (10 patterns/day) or only spaced training. Transgenerational effects of adolescent nicotine exposure were observed as greater difficulty in learning a "violation element" of the pattern, which indicated that rats were impaired in the ability to encode and remember multiple sequential elements as compound or configural cues. The results indicated that for rats that received massed training, F1 generation rats with adolescent nicotine exposure whose F0 generation parents also experienced adolescent nicotine exposure showed poorer learning of the violation element than rats that experienced adolescent nicotine exposure only in the F1 generation. Thus, adolescent nicotine exposure in one generation of rats produced a cognitive impairment in the next generation. Copyright © 2016 Elsevier Inc. All rights reserved.

Motor unit firing rate patterns during voluntary muscle force generation: a simulation study

NASA Astrophysics Data System (ADS)

Hu, Xiaogang; Rymer, William Z.; Suresh, Nina L.

2014-04-01

Objective. Muscle force is generated by a combination of motor unit (MU) recruitment and changes in the discharge rate of active MUs. There have been two basic MU recruitment and firing rate paradigms reported in the literature, which describe the control of the MUs during force generation. The first (termed the reverse ‘onion skin’ profile), exhibits lower firing rates for lower threshold units, with higher firing rates occurring in higher threshold units. The second (termed the ‘onion skin’ profile), exhibits an inverse arrangement, with lower threshold units reaching higher firing rates. Approach. Using a simulation of the MU activity in a hand muscle, this study examined the force generation capacity and the variability of the muscle force magnitude at different excitation levels of the MU pool under these two different MU control paradigms. We sought to determine which rate/recruitment scheme was more efficient for force generation, and which scheme gave rise to the lowest force variability. Main results. We found that the force output of both firing patterns leads to graded force output at low excitation levels, and that the force generation capacity of the two different paradigms diverged around 50% excitation. In the reverse ‘onion skin’ pattern, at 100% excitation, the force output reached up to 88% of maximum force, whereas for the ‘onion skin’ pattern, the force output only reached up to 54% of maximum force at 100% excitation. The force variability was lower at the low to moderate force levels under the ‘onion skin’ paradigm than with the reverse ‘onion skin’ firing patterns, but this effect was reversed at high force levels. Significance. This study captures the influence of MU recruitment and firing rate organization on muscle force properties, and our results suggest that the different firing organizations can be beneficial at different levels of voluntary muscle force generation and perhaps for different tasks.

Minimal-resource computer program for automatic generation of ocean wave ray or crest diagrams in shoaling waters

NASA Technical Reports Server (NTRS)

Poole, L. R.; Lecroy, S. R.; Morris, W. D.

1977-01-01

A computer program for studying linear ocean wave refraction is described. The program features random-access modular bathymetry data storage. Three bottom topography approximation techniques are available in the program which provide varying degrees of bathymetry data smoothing. Refraction diagrams are generated automatically and can be displayed graphically in three forms: Ray patterns with specified uniform deepwater ray density, ray patterns with controlled nearshore ray density, or crest patterns constructed by using a cubic polynomial to approximate crest segments between adjacent rays.

Towards control of dexterous hand manipulations using a silicon Pattern Generator.

PubMed

Russell, Alexander; Tenore, Francesco; Singhal, Girish; Thakor, Nitish; Etienne-Cummings, Ralph

2008-01-01

This work demonstrates how an in silico Pattern Generator (PG) can be used as a low power control system for rhythmic hand movements in an upper-limb prosthesis. Neural spike patterns, which encode rotation of a cylindrical object, were implemented in a custom Very Large Scale Integration chip. PG control was tested by using the decoded control signals to actuate the fingers of a virtual prosthetic arm. This system provides a framework for prototyping and controlling dexterous hand manipulation tasks in a compact and efficient solution.

Order parameter for bursting polyrhythms in multifunctional central pattern generators

NASA Astrophysics Data System (ADS)

Wojcik, Jeremy; Clewley, Robert; Shilnikov, Andrey

2011-05-01

We examine multistability of several coexisting bursting patterns in a central pattern generator network composed of three Hodgkin-Huxley type cells coupled reciprocally by inhibitory synapses. We establish that the control of switching between bursting polyrhythms and their bifurcations are determined by the temporal characteristics, such as the duty cycle, of networked interneurons and the coupling strength asymmetry. A computationally effective approach to the reduction of dynamics of the nine-dimensional network to two-dimensional Poincaré return mappings for phase lags between the interneurons is presented.

Exploratory Movement Generates Higher-Order Information That Is Sufficient for Accurate Perception of Scaled Egocentric Distance

PubMed Central

Mantel, Bruno; Stoffregen, Thomas A.; Campbell, Alain; Bardy, Benoît G.

2015-01-01

Body movement influences the structure of multiple forms of ambient energy, including optics and gravito-inertial force. Some researchers have argued that egocentric distance is derived from inferential integration of visual and non-visual stimulation. We suggest that accurate information about egocentric distance exists in perceptual stimulation as higher-order patterns that extend across optics and inertia. We formalize a pattern that specifies the egocentric distance of a stationary object across higher-order relations between optics and inertia. This higher-order parameter is created by self-generated movement of the perceiver in inertial space relative to the illuminated environment. For this reason, we placed minimal restrictions on the exploratory movements of our participants. We asked whether humans can detect and use the information available in this higher-order pattern. Participants judged whether a virtual object was within reach. We manipulated relations between body movement and the ambient structure of optics and inertia. Judgments were precise and accurate when the higher-order optical-inertial parameter was available. When only optic flow was available, judgments were poor. Our results reveal that participants perceived egocentric distance from the higher-order, optical-inertial consequences of their own exploratory activity. Analysis of participants’ movement trajectories revealed that self-selected movements were complex, and tended to optimize availability of the optical-inertial pattern that specifies egocentric distance. We argue that accurate information about egocentric distance exists in higher-order patterns of ambient energy, that self-generated movement can generate these higher-order patterns, and that these patterns can be detected and used to support perception of egocentric distance that is precise and accurate. PMID:25856410

Age-Related Variability in Tongue Pressure Patterns for Maximum Isometric and Saliva Swallowing Tasks

PubMed Central

Peladeau-Pigeon, Melanie

2017-01-01

Purpose The ability to generate tongue pressure plays a major role in bolus transport in swallowing. In studies of motor control, stability or variability of movement is a feature that changes with age, disease, task complexity, and perturbation. In this study, we explored whether age and tongue strength influence the stability of the tongue pressure generation pattern during isometric and swallowing tasks in healthy volunteers. Method Tongue pressure data, collected using the Iowa Oral Performance Instrument, were analyzed from 84 participants in sex-balanced and decade age-group strata. Tasks included maximum anterior and posterior isometric pressures and regular-effort saliva swallows. The cyclic spatiotemporal index (cSTI) was used to capture stability (vs. variability) in patterns of pressure generation. Mixed-model repeated measures analyses of covariance were performed separately for each task (anterior and posterior isometric pressures, saliva swallows) with between-participant factors of age group and sex, a within-participant factor of task repetition, and a continuous covariate of tongue strength. Results Neither age group nor sex effects were found. There was no significant relationship between tongue strength and the cSTI on the anterior isometric tongue pressure task (r = −.11). For the posterior isometric tongue pressure task, a significant negative correlation (r = −.395) was found between tongue strength and the cSTI. The opposite pattern of a significant positive correlation (r = .29) between tongue strength and the cSTI was seen for the saliva swallow task. Conclusions Tongue pressure generation patterns appear highly stable across repeated maximum isometric and saliva swallow tasks, despite advancing age. Greater pattern variability is seen with weaker posterior isometric pressures. Overall, saliva swallows had the lowest pressure amplitudes and highest pressure pattern variability as measured by the cSTI. PMID:29114767

Spatial pattern and ecological process in the coffee agroforestry system.

PubMed

Perfecto, Ivette; Vandermeer, John

2008-04-01

The coffee agroforestry system provides an ideal platform for the study of spatial ecology. The uniform pattern of the coffee plants and shade trees allows for the study of pattern generation through intrinsic biological forces rather than extrinsic habitat patchiness. Detailed studies, focusing on a key mutualism between an ant (Azteca instabilis) and a scale insect (Coccus viridis), conducted in a 45-ha plot in a coffee agroforestry system have provided insights into (1) the quantitative evaluation of spatial pattern of the scale insect Coccus viridis on coffee bushes, (2) the mechanisms for the generation of patterns through the combination of local satellite ant nest formation and regional control from natural enemies, and (3) the consequences of the spatial pattern for the stability of predator-prey (host-parasitoid) systems, for a key coccinelid beetle preying on the scale insects and a phorid fly parasitoid parasitizing the ant.

Pigment cell interactions and differential xanthophore recruitment underlying zebrafish stripe reiteration and Danio pattern evolution

PubMed Central

Patterson, Larissa B.; Bain, Emily J.; Parichy, David M.

2014-01-01

Fishes have diverse pigment patterns, yet mechanisms of pattern evolution remain poorly understood. In zebrafish, Danio rerio, pigment-cell autonomous interactions generate dark stripes of melanophores that alternate with light interstripes of xanthophores and iridophores. Here, we identify mechanisms underlying the evolution of a uniform pattern in D. albolineatus in which all three pigment cell classes are intermingled. We show that in this species xanthophores differentiate precociously over a wider area, and that cis regulatory evolution has increased expression of xanthogenic Colony Stimulating Factor-1 (Csf1). Expressing Csf1 similarly in D. rerio has cascading effects, driving the intermingling of all three pigment cell classes and resulting in the loss of stripes, as in D. albolineatus. Our results identify novel mechanisms of pattern development and illustrate how pattern diversity can be generated when a core network of pigment-cell autonomous interactions is coupled with changes in pigment cell differentiation. PMID:25374113

Predictive model for CO2 generation and decay in building envelopes

NASA Astrophysics Data System (ADS)

Aglan, Heshmat A.

2003-01-01

Understanding carbon dioxide generation and decay patterns in buildings with high occupancy levels is useful to identify their indoor air quality, air change rates, percent fresh air makeup, occupancy pattern, and how a variable air volume system to off-set undesirable CO2 level can be modulated. A mathematical model governing the generation and decay of CO2 in building envelopes with forced ventilation due to high occupancy is developed. The model has been verified experimentally in a newly constructed energy efficient healthy house. It was shown that the model accurately predicts the CO2 concentration at any time during the generation and decay processes.

Characterizing Urban Household Waste Generation and Metabolism Considering Community Stratification in a Rapid Urbanizing Area of China.

PubMed

Xiao, Lishan; Lin, Tao; Chen, Shaohua; Zhang, Guoqin; Ye, Zhilong; Yu, Zhaowu

2015-01-01

The relationship between social stratification and municipal solid waste generation remains uncertain under current rapid urbanization. Based on a multi-object spatial sampling technique, we selected 191 households in a rapidly urbanizing area of Xiamen, China. The selected communities were classified into three types: work-unit, transitional, and commercial communities in the context of housing policy reform in China. Field survey data were used to characterize household waste generation patterns considering community stratification. Our results revealed a disparity in waste generation profiles among different households. The three community types differed with respect to family income, living area, religious affiliation, and homeowner occupation. Income, family structure, and lifestyle caused significant differences in waste generation among work-unit, transitional, and commercial communities, respectively. Urban waste generation patterns are expected to evolve due to accelerating urbanization and associated community transition. A multi-scale integrated analysis of societal and ecosystem metabolism approach was applied to waste metabolism linking it to particular socioeconomic conditions that influence material flows and their evolution. Waste metabolism, both pace and density, was highest for family structure driven patterns, followed by lifestyle and income driven. The results will guide community-specific management policies in rapidly urbanizing areas.

Force generation within tissues during development

NASA Astrophysics Data System (ADS)

Kasza, Karen

During embryonic development, multicellular tissues physically change shape, move, and grow. Changes in epithelial tissue organization are often accomplished by local movements of cells that are driven largely by forces generated by the motor protein myosin II. These forces are patterned to orient cell movements, resulting in changes in tissue shape and organization to build functional tissues and organs. To investigate the mechanisms of force generation in vivo, we use the fruit fly embryo as a model system. Spatial patterns of forces orient cell movements to drive rapid tissue elongation along the head-to-tail axis of the embryo. I will describe how studying embryos generated with engineered myosin variants provides insight into where, when, and how forces are generated to efficiently reorganize tissues. We found that a myosin variant that is locked-in to the active or ``on'' state accelerates cell movements, while two mutant myosin variants associated with human disease produce slowed cell movement. These myosin variants all disrupt tissue elongation, but live imaging and biophysical measurements reveal distinct effects on myosin organization and dynamics within cells and uncover mechanisms that control the spatial and temporal patterns of force generation. These studies shed light not only on how defects in force generation contribute to disease but also on physical principles at work in active, living materials.

Does Epileptiform Activity Represent a Failure of Neuromodulation to Control Central Pattern Generator-Like Neocortical Behavior?

PubMed Central

Traub, Roger D.; Whittington, Miles A.; Hall, Stephen P.

2017-01-01

Rhythmic motor patterns in invertebrates are often driven by specialized “central pattern generators” (CPGs), containing small numbers of neurons, which are likely to be “identifiable” in one individual compared with another. The dynamics of any particular CPG lies under the control of modulatory substances, amines, or peptides, entering the CPG from outside it, or released by internal constituent neurons; consequently, a particular CPG can generate a given rhythm at different frequencies and amplitudes, and perhaps even generate a repertoire of distinctive patterns. The mechanisms exploited by neuromodulators in this respect are manifold: Intrinsic conductances (e.g., calcium, potassium channels), conductance state of postsynaptic receptors, degree of plasticity, and magnitude and kinetics of transmitter release can all be affected. The CPG concept has been generalized to vertebrate motor pattern generating circuits (e.g., for locomotion), which may contain large numbers of neurons – a construct that is sensible, if there is enough redundancy: that is, the large number of neurons consists of only a small number of classes, and the cells within any one class act stereotypically. Here we suggest that CPG and modulator ideas may also help to understand cortical oscillations, normal ones, and particularly transition to epileptiform pathology. Furthermore, in the case illustrated, the mechanism of the transition appears to be an exaggerated form of a normal modulatory action used to influence sensory processing. PMID:29093667

Crack displacement sensing and measurement in concrete using circular grating moire fringes and pattern matching

NASA Astrophysics Data System (ADS)

Chan, H. M.; Yen, K. S.; Ratnam, M. M.

2008-09-01

The moire method has been extensively studied in the past and applied in various engineering applications. Several techniques are available for generating the moire fringes in these applications, which include moire interferometry, projection moire, shadow moire, moire deflectometry etc. Most of these methods use the superposition of linear gratings to generate the moire patterns. The use of non-linear gratings, such as circular, radial and elongated gratings has received less attention from the research community. The potential of non-linear gratings in engineering measurement has been realized in a limited number of applications, such as rotation measurement, measurement of linear displacement, measurement of expansion coefficients of materials and measurement of strain distribution. In this work, circular gratings of different pitch were applied to the sensing and measurement of crack displacement in concrete structures. Gratings of pitch 0.50 mm and 0.55 mm were generated using computer software and attached to two overlapping acrylic plates that were bonded to either side of the crack. The resulting moire patterns were captured using a standard digital camera and compared with a set of reference patterns generated using a precision positioning stage. Using several image pre-processing stages, such as filtering and morphological operations, and pattern matching the magnitude displacements along two orthogonal axes can be detected with a resolution of 0.05 mm.

Neural Regulation Of Chromatophore Function In Cephalopods

DTIC Science & Technology

2015-05-19

which include octopus , squid and cuttlefish, are the only animals able to generate active body patterns directly controlled by the nervous system...Pattering Behavior, the ability of cephalopod mollusks to generate numerous and highly complex body patterns. Cephalopods, which include octopus , squid...cephalopod species, Octopus vulgaris with the Fiorito lab at the Stazione Zoologica in Napoli, Italy and showed that regeneration follows a

Mining Productive-Associated Periodic-Frequent Patterns in Body Sensor Data for Smart Home Care

PubMed Central

Ismail, Walaa N.; Hassan, Mohammad Mehedi

2017-01-01

The understanding of various health-oriented vital sign data generated from body sensor networks (BSNs) and discovery of the associations between the generated parameters is an important task that may assist and promote important decision making in healthcare. For example, in a smart home scenario where occupants’ health status is continuously monitored remotely, it is essential to provide the required assistance when an unusual or critical situation is detected in their vital sign data. In this paper, we present an efficient approach for mining the periodic patterns obtained from BSN data. In addition, we employ a correlation test on the generated patterns and introduce productive-associated periodic-frequent patterns as the set of correlated periodic-frequent items. The combination of these measures has the advantage of empowering healthcare providers and patients to raise the quality of diagnosis as well as improve treatment and smart care, especially for elderly people in smart homes. We develop an efficient algorithm named PPFP-growth (Productive Periodic-Frequent Pattern-growth) to discover all productive-associated periodic frequent patterns using these measures. PPFP-growth is efficient and the productiveness measure removes uncorrelated periodic items. An experimental evaluation on synthetic and real datasets shows the efficiency of the proposed PPFP-growth algorithm, which can filter a huge number of periodic patterns to reveal only the correlated ones. PMID:28445441

Mining Productive-Associated Periodic-Frequent Patterns in Body Sensor Data for Smart Home Care.

PubMed

Ismail, Walaa N; Hassan, Mohammad Mehedi

2017-04-26

The understanding of various health-oriented vital sign data generated from body sensor networks (BSNs) and discovery of the associations between the generated parameters is an important task that may assist and promote important decision making in healthcare. For example, in a smart home scenario where occupants' health status is continuously monitored remotely, it is essential to provide the required assistance when an unusual or critical situation is detected in their vital sign data. In this paper, we present an efficient approach for mining the periodic patterns obtained from BSN data. In addition, we employ a correlation test on the generated patterns and introduce productive-associated periodic-frequent patterns as the set of correlated periodic-frequent items. The combination of these measures has the advantage of empowering healthcare providers and patients to raise the quality of diagnosis as well as improve treatment and smart care, especially for elderly people in smart homes. We develop an efficient algorithm named PPFP-growth (Productive Periodic-Frequent Pattern-growth) to discover all productive-associated periodic frequent patterns using these measures. PPFP-growth is efficient and the productiveness measure removes uncorrelated periodic items. An experimental evaluation on synthetic and real datasets shows the efficiency of the proposed PPFP-growth algorithm, which can filter a huge number of periodic patterns to reveal only the correlated ones.

A selection criterion for patterns in reaction–diffusion systems

PubMed Central

2014-01-01

Background Alan Turing’s work in Morphogenesis has received wide attention during the past 60 years. The central idea behind his theory is that two chemically interacting diffusible substances are able to generate stable spatial patterns, provided certain conditions are met. Ever since, extensive work on several kinds of pattern-generating reaction diffusion systems has been done. Nevertheless, prediction of specific patterns is far from being straightforward, and a great deal of interest in deciphering how to generate specific patterns under controlled conditions prevails. Results Techniques allowing one to predict what kind of spatial structure will emerge from reaction–diffusion systems remain unknown. In response to this need, we consider a generalized reaction diffusion system on a planar domain and provide an analytic criterion to determine whether spots or stripes will be formed. Our criterion is motivated by the existence of an associated energy function that allows bringing in the intuition provided by phase transitions phenomena. Conclusions Our criterion is proved rigorously in some situations, generalizing well-known results for the scalar equation where the pattern selection process can be understood in terms of a potential. In more complex settings it is investigated numerically. Our work constitutes a first step towards rigorous pattern prediction in arbitrary geometries/conditions. Advances in this direction are highly applicable to the efficient design of Biotechnology and Developmental Biology experiments, as well as in simplifying the analysis of morphogenetic models. PMID:24476200

Adapted random sampling patterns for accelerated MRI.

PubMed

Knoll, Florian; Clason, Christian; Diwoky, Clemens; Stollberger, Rudolf

2011-02-01

Variable density random sampling patterns have recently become increasingly popular for accelerated imaging strategies, as they lead to incoherent aliasing artifacts. However, the design of these sampling patterns is still an open problem. Current strategies use model assumptions like polynomials of different order to generate a probability density function that is then used to generate the sampling pattern. This approach relies on the optimization of design parameters which is very time consuming and therefore impractical for daily clinical use. This work presents a new approach that generates sampling patterns by making use of power spectra of existing reference data sets and hence requires neither parameter tuning nor an a priori mathematical model of the density of sampling points. The approach is validated with downsampling experiments, as well as with accelerated in vivo measurements. The proposed approach is compared with established sampling patterns, and the generalization potential is tested by using a range of reference images. Quantitative evaluation is performed for the downsampling experiments using RMS differences to the original, fully sampled data set. Our results demonstrate that the image quality of the method presented in this paper is comparable to that of an established model-based strategy when optimization of the model parameter is carried out and yields superior results to non-optimized model parameters. However, no random sampling pattern showed superior performance when compared to conventional Cartesian subsampling for the considered reconstruction strategy.

Polymorphism and methylation patterns in Agave tequilana Weber var. 'Azul' plants propagated asexually by three different methods.

PubMed

Díaz-Martínez, Miriam; Nava-Cedillo, Alejandro; Guzmán-López, José Alfredo; Escobar-Guzmán, Rocío; Simpson, June

2012-04-01

Genetic variation in three forms of asexually propagated Agave tequilana Weber var. 'Azul' plants namely offsets, bulbils and in vitro cultured individuals was studied by AFLP analysis. Low levels of variation were observed between mother plants and offsets and a higher level between mother plant and bulbils. Families obtained from commercial plantations showed lower levels of variation in comparison to families grown as ornamentals. No variation was observed between the original explant and four generations of in vitro cultured plants. Epigenetic variation was also studied by analyzing changes in methylation patterns between mother plants and offspring in each form of asexual reproduction. Offsets and bulbils showed an overall decrease in methylation whereas in vitro cultured plants showed patterns specific to each generation: Generations 1 and 4 showed overall demethylation whereas Generations 2 and 3 showed increased methylation. Analysis of ESTs associated with transposable elements revealed higher proportions of ESTs from Ty1-copia-like, Gypsy and CACTA transposable elements in cDNA libraries obtained from pluripotent tissue suggesting a possible correlation between methylation patterns, expression of transposable element associated genes and somaclonal variation. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Origins of adult pigmentation: diversity in pigment stem cell lineages and implications for pattern evolution

PubMed Central

Spiewak, Jessica E.

2014-01-01

Summary Teleosts comprise about half of all vertebrate species and exhibit an extraordinary diversity of adult pigment patterns that function in shoaling, camouflage and mate choice and have played important roles in speciation. Here, we review recent studies that have identified several distinct neural crest lineages, with distinct genetic requirements, that give rise to adult pigment cells in fishes. These lineages include post-embryonic, peripheral nerve associated stem cells that generate black melanophores and iridescent iridophores, cells derived directly from embryonic neural crest cells that generate yellow-orange xanthophores, and bipotent stem cells that generate both melanophores and xanthophores. This complexity in adult chromatophore lineages has implications for our understanding of adult traits, melanoma, and the evolutionary diversification of pigment cell lineages and patterns. PMID:25421288

Phase velocity nonuniformity-resulted beam patterns in difference frequency generation.

PubMed

Lu, Daquan; Qian, Liejia; Li, Yongzhong; Yang, Hua; Zhu, Heyuan; Fan, Dianyuan

2007-04-16

The evolution of the difference frequency generation between a planar pump wave and a focused signal wave has been numerically investigated in this paper. We show that, at the difference frequency wave, various beam patterns such as ring and moon-like, are resulted due to the nonuniform distribution of phase velocity in the focused signal wave. The subluminal and superluminal regions can be identified by the intersection of two generated beam profiles that correspond to a pair of phase-mismatches with equal value but opposite signs.

Temporally diverse firing patterns in olfactory receptor neurons underlie spatiotemporal neural codes for odors

PubMed Central

Raman, Baranidharan; Joseph, Joby; Tang, Jeff; Stopfer, Mark

2010-01-01

Odorants are represented as spatiotemporal patterns of spikes in neurons of the antennal lobe (AL, insects) and olfactory bulb (OB, vertebrates). These response patterns have been thought to arise primarily from interactions within the AL/OB, an idea supported, in part, by the assumption that olfactory receptor neurons (ORNs) respond to odorants with simple firing patterns. However, activating the AL directly with simple pulses of current evoked responses in AL neurons that were much less diverse, complex, and enduring than responses elicited by odorants. Similarly, models of the AL driven by simplistic inputs generated relatively simple output. How then are dynamic neural codes for odors generated? Consistent with recent results from several other species, our recordings from locust ORNs showed a great diversity of temporal structure. Further, we found that, viewed as a population, many response features of ORNs were remarkably similar to those observed within the AL. Using a set of computational models constrained by our electrophysiological recordings, we found that the temporal heterogeneity of responses of ORNs critically underlies the generation of spatiotemporal odor codes in the AL. A test then performed in vivo confirmed that, given temporally homogeneous input, the AL cannot create diverse spatiotemporal patterns on its own; however, given temporally heterogeneous input, the AL generated realistic firing patterns. Finally, given the temporally structured input provided by ORNs, we clarified several separate, additional contributions of the AL to olfactory information processing. Thus, our results demonstrate the origin and subsequent reformatting of spatiotemporal neural codes for odors. PMID:20147528

A random approach of test macro generation for early detection of hotspots

NASA Astrophysics Data System (ADS)

Lee, Jong-hyun; Kim, Chin; Kang, Minsoo; Hwang, Sungwook; Yang, Jae-seok; Harb, Mohammed; Al-Imam, Mohamed; Madkour, Kareem; ElManhawy, Wael; Kwan, Joe

2016-03-01

Multiple-Patterning Technology (MPT) is still the preferred choice over EUV for the advanced technology nodes, starting the 20nm node. Down the way to 7nm and 5nm nodes, Self-Aligned Multiple Patterning (SAMP) appears to be one of the effective multiple patterning techniques in terms of achieving small pitch of printed lines on wafer, yet its yield is in question. Predicting and enhancing the yield in the early stages of technology development are some of the main objectives for creating test macros on test masks. While conventional yield ramp techniques for a new technology node have relied on using designs from previous technology nodes as a starting point to identify patterns for Design of Experiment (DoE) creation, these techniques are challenging to apply in the case of introducing an MPT technique like SAMP that did not exist in previous nodes. This paper presents a new strategy for generating test structures based on random placement of unit patterns that can construct more meaningful bigger patterns. Specifications governing the relationships between those unit patterns can be adjusted to generate layout clips that look like realistic SAMP designs. A via chain can be constructed to connect the random DoE of SAMP structures through a routing layer to external pads for electrical measurement. These clips are decomposed according to the decomposition rules of the technology into the appropriate mandrel and cut masks. The decomposed clips can be tested through simulations, or electrically on silicon to discover hotspots. The hotspots can be used in optimizing the fabrication process and models to fix them. They can also be used as learning patterns for DFM deck development. By expanding the size of the randomly generated test structures, more hotspots can be detected. This should provide a faster way to enhance the yield of a new technology node.

Emergent Archetype Hydrological-Biogeochemical Response Patterns in Heterogeneous Catchments

NASA Astrophysics Data System (ADS)

Jawitz, J. W.; Gall, H. E.; Rao, P.

2013-12-01

What can spatiotemporally integrated patterns observed in stream hydrologic and biogeochemical signals generated in response to transient hydro-climatic and anthropogenic forcing tell us about the interactions between spatially heterogeneous soil-mediated hydrological and biogeochemical processes? We seek to understand how the spatial structure of solute sources coupled with hydrologic responses affect observed concentration-discharge (C-Q) patterns. These patterns are expressions of the spatiotemporal structure of solute loads exported from managed catchments, and their likely ecological consequences manifested in receiving water bodies (e.g., wetlands, rivers, lakes, and coastal waters). We investigated the following broad questions: (1) How does the correlation between flow-generating areas and biogeochemical source areas across a catchment evolve under stochastic hydro-climatic forcing? (2) What are the feasible hydrologic and biogeochemical responses that lead to the emergence of the observed archetype C-Q patterns? and; (3) What implications do these coupled dynamics have for catchment monitoring and implementation of management practices? We categorize the observed temporal signals into three archetypical C-Q patterns: dilution; accretion, and constant concentration. We introduce a parsimonious stochastic model of heterogeneous catchments, which act as hydrologic and biogeochemical filters, to examine the relationship between spatial heterogeneity and temporal history of solute export signals. The core concept of the modeling framework is considering the types and degree of spatial correlation between solute source zones and flow generating zones, and activation of different portions of the catchments during rainfall events. Our overarching hypothesis is that each of the archetype C-Q patterns can be generated by explicitly linking landscape-scale hydrologic responses and spatial distributions of solute source properties within a catchment. The model simulations reproduce the three major C-Q patterns observed in published data, offering valuable insight into coupled catchment processes. The findings have important implications for effective catchment management for water quality improvement, and stream monitoring strategies.

SPMBR: a scalable algorithm for mining sequential patterns based on bitmaps

NASA Astrophysics Data System (ADS)

Xu, Xiwei; Zhang, Changhai

2013-12-01

Now some sequential patterns mining algorithms generate too many candidate sequences, and increase the processing cost of support counting. Therefore, we present an effective and scalable algorithm called SPMBR (Sequential Patterns Mining based on Bitmap Representation) to solve the problem of mining the sequential patterns for large databases. Our method differs from previous related works of mining sequential patterns. The main difference is that the database of sequential patterns is represented by bitmaps, and a simplified bitmap structure is presented firstly. In this paper, First the algorithm generate candidate sequences by SE(Sequence Extension) and IE(Item Extension), and then obtain all frequent sequences by comparing the original bitmap and the extended item bitmap .This method could simplify the problem of mining the sequential patterns and avoid the high processing cost of support counting. Both theories and experiments indicate that the performance of SPMBR is predominant for large transaction databases, the required memory size for storing temporal data is much less during mining process, and all sequential patterns can be mined with feasibility.

Global-scale tectonic patterns on Pluto

NASA Astrophysics Data System (ADS)

Matsuyama, I.; Keane, J. T.; Kamata, S.

2016-12-01

The New Horizons spacecraft revealed a global-scale tectonic pattern on the surface of Pluto which is presumably related to its formation and early evolution. Changes in the rotational and tidal potentials, expansion, and loading can generate stresses capable of producing global-scale tectonic patterns. The current alignment of Sputnik Planum with the tidal axis suggests a reorientation of Pluto relative to the rotation and tidal axes, or true polar wander. This reorientation can be driven by mass loading associated with Sputnik Planum. We developed a general theoretical formalism for the calculation of tectonic patterns due to a variety of process including true polar wander, loading, and expansion. The formalism is general enough to be applicable to non-axisymmetric loads. We illustrate that the observed global-scale tectonic pattern can be explained by stresses generated by true polar wander, Sputnik Planum loading, and expansion.

Research on trading patterns of large users' direct power purchase considering consumption of clean energy

NASA Astrophysics Data System (ADS)

Guojun, He; Lin, Guo; Zhicheng, Yu; Xiaojun, Zhu; Lei, Wang; Zhiqiang, Zhao

2017-03-01

In order to reduce the stochastic volatility of supply and demand, and maintain the electric power system's stability after large scale stochastic renewable energy sources connected to grid, the development and consumption should be promoted by marketing means. Bilateral contract transaction model of large users' direct power purchase conforms to the actual situation of our country. Trading pattern of large users' direct power purchase is analyzed in this paper, characteristics of each power generation are summed up, and centralized matching mode is mainly introduced. Through the establishment of power generation enterprises' priority evaluation index system and the analysis of power generation enterprises' priority based on fuzzy clustering, the sorting method of power generation enterprises' priority in trading patterns of large users' direct power purchase is put forward. Suggestions for trading mechanism of large users' direct power purchase are offered by this method, which is good for expand the promotion of large users' direct power purchase further.

Comparative assessment of ceramic media for drinking water biofiltration.

PubMed

Sharma, Dikshant; Taylor-Edmonds, Liz; Andrews, Robert C

2018-01-01

Media type is a critical design consideration when implementing biofiltration for drinking water treatment. Granular activated carbon (GAC) has been shown to provide superior performance when compared to a wide range of media types, largely due to its higher surface area. Engineered ceramic media is an attractive alternative to GAC as it has a similar surface area but at a lower cost. This pilot-scale biofiltration study compared the performance of GAC, anthracite and two different effective sizes of ceramic (CER) media (1.0 mm and 1.2 mm), in terms of dissolved organic carbon (DOC), head loss, turbidity, and disinfection by-product formation potential (DBPFP). Biological acclimation was monitored using adenosine tri-phosphate (ATP) measurements; biomass was further examined using laccase and esterase enzyme activity assays. When compared to other media types examined, biological GAC had higher (p > 0.05) removals of DOC (9.8 ± 3.8%), trihalomethane formation potential (THMFP, 26.3 ± 10.2%), and haloacetic acid formation potential (HAAFP, 27.2 ± 14.0%). CER media required 6-7 months to biologically acclimate, while filters containing GAC and anthracite were biologically active (>100 ng of ATP/g media) following 30-45 days of operation. Once acclimated, ATP values of 243 and 208 ng/g attained for CER 1.0 and 1.2, respectively, were statistically comparable to GAC (244 ng/g) and higher than anthracite (110 ng/g), however this did not translate into greater organics removal. Esterase and laccase enzyme kinetics were highest for GAC, while CER was shown to have greater biodegradation potential than anthracite. The four media types attained similar turbidity reduction (p > 0.05), however ceramic media filters were observed to have run times which were 1.5-2.3 times longer when compared to anthracite, which could represent potential cost savings in terms of energy for pumping and backwash requirements. Overall, ceramic media was shown to be a potential alternative to anthracite when considering biofiltration, especially during cold water conditions (T < 10 °C). Copyright © 2017 Elsevier Ltd. All rights reserved.

Long-term variability of wind patterns at hub-height over Texas

NASA Astrophysics Data System (ADS)

Jung, J.; Jeon, W.; Choi, Y.; Souri, A.

2017-12-01

Wind energy is getting more attention because of its environmentally friendly attributes. Texas is a state with significant capacity and number of wind turbines. Wind power generation is significantly affected by wind patterns, and it is important to understand this seasonal and decadal variability for long-term power generation from wind turbines. This study focused on the trends of changes in wind pattern and its strength at two hub-heights (80 m and 110 m) over 30-years (1986 to 2015). We only analyzed summer data(June to September) because of concentrated electricity usage in Texas. We extracted hub-height wind data (U and V components) from the three-hourly National Centers for Environmental Prediction-North American Regional Reanalysis (NCEP-NARR) and classified wind patterns properly by using nonhierarchical K-means method. Hub-height wind patterns in summer seasons of 1986 to 2015 were classified in six classes at day and seven classes at night. Mean wind speed was 4.6 ms-1 at day and 5.4 ms-1 at night, but showed large variability in time and space. We combined each cluster's frequencies and wind speed tendencies with large scale atmospheric circulation features and quantified the amount of wind power generation.

Laser-induced erasable patterns in a N* liquid crystal on an iron doped lithium niobate surface.

PubMed

Habibpourmoghadam, Atefeh; Lucchetti, Liana; Evans, Dean R; Reshetnyak, Victor Y; Omairat, Faissal; Schafforz, Samuel L; Lorenz, Alexander

2017-10-16

A chiral nematic (N*) liquid crystal (LC) was hybridized with a z-cut iron doped lithium niobate (Fe:LN) substrate and exposed with a focused continuous wave diode laser beam. The N* LC layer was confined with a cover glass to provide a homogeneous LC layer thickness. Two distinct kinds of test cells were investigated, one with an uncoated glass covering slip and one with an indium tin oxide (ITO) coated cover glass. Photo generated electric fields (generated in the Fe:LN) resulted in a localized defect formation and textural transitions in the N* LC. Due to field confinement, the field induced responses were more localized in samples with ITO coated cover glasses. By scanning the laser beam on programmed trajectories, formation of persistent patterns could be achieved in the N* LC layer. Polarized optical microscopy of the exposed samples revealed that these patterns consisted of adjacent circular Frank-Pryce defects. Exposure with a slightly defocused laser beam could be applied selectively to erase these patterns. Thus, a promising method is reported to generate reconfigurable patterns, photonic motives, and touch sensitive devices in a hybridized N* LC with micron accuracy.

Deductive Glue Code Synthesis for Embedded Software Systems Based on Code Patterns

NASA Technical Reports Server (NTRS)

Liu, Jian; Fu, Jicheng; Zhang, Yansheng; Bastani, Farokh; Yen, I-Ling; Tai, Ann; Chau, Savio N.

2006-01-01

Automated code synthesis is a constructive process that can be used to generate programs from specifications. It can, thus, greatly reduce the software development cost and time. The use of formal code synthesis approach for software generation further increases the dependability of the system. Though code synthesis has many potential benefits, the synthesis techniques are still limited. Meanwhile, components are widely used in embedded system development. Applying code synthesis to component based software development (CBSD) process can greatly enhance the capability of code synthesis while reducing the component composition efforts. In this paper, we discuss the issues and techniques for applying deductive code synthesis techniques to CBSD. For deductive synthesis in CBSD, a rule base is the key for inferring appropriate component composition. We use the code patterns to guide the development of rules. Code patterns have been proposed to capture the typical usages of the components. Several general composition operations have been identified to facilitate systematic composition. We present the technique for rule development and automated generation of new patterns from existing code patterns. A case study of using this method in building a real-time control system is also presented.

The Human Central Pattern Generator for Locomotion.

PubMed

Minassian, Karen; Hofstoetter, Ursula S; Dzeladini, Florin; Guertin, Pierre A; Ijspeert, Auke

2017-03-01

The ability of dedicated spinal circuits, referred to as central pattern generators (CPGs), to produce the basic rhythm and neural activation patterns underlying locomotion can be demonstrated under specific experimental conditions in reduced animal preparations. The existence of CPGs in humans is a matter of debate. Equally elusive is the contribution of CPGs to normal bipedal locomotion. To address these points, we focus on human studies that utilized spinal cord stimulation or pharmacological neuromodulation to generate rhythmic activity in individuals with spinal cord injury, and on neuromechanical modeling of human locomotion. In the absence of volitional motor control and step-specific sensory feedback, the human lumbar spinal cord can produce rhythmic muscle activation patterns that closely resemble CPG-induced neural activity of the isolated animal spinal cord. In this sense, CPGs in humans can be defined by the activity they produce. During normal locomotion, CPGs could contribute to the activation patterns during specific phases of the step cycle and simplify supraspinal control of step cycle frequency as a feedforward component to achieve a targeted speed. Determining how the human CPGs operate will be essential to advance the theory of neural control of locomotion and develop new locomotor neurorehabilitation paradigms.

36 CFR 242.16 - Customary and traditional use determination process.

Code of Federal Regulations, 2013 CFR

2013-07-01

... generation to generation; (7) A pattern of use in which the harvest is shared or distributed within a... storing fish or wildlife which has been traditionally used by past generations, including consideration of...

Impact of cercal air currents on singing motor pattern generation in the cricket (Gryllus bimaculatus DeGeer)

PubMed Central

2015-01-01

The cercal system of crickets detects low-frequency air currents produced by approaching predators and self-generated air currents during singing, which may provide sensory feedback to the singing motor network. We analyzed the effect of cercal stimulation on singing motor pattern generation to reveal the response of a singing interneuron to predator-like signals and to elucidate the possible role of self-generated air currents during singing. In fictive singing males, we recorded an interneuron of the singing network while applying air currents to the cerci; additionally, we analyzed the effect of abolishing the cercal system in freely singing males. In fictively singing crickets, the effect of short air stimuli is either to terminate prematurely or to lengthen the interchirp interval, depending on their phase in the chirp cycle. Within our stimulation paradigm, air stimuli of different velocities and durations always elicited an inhibitory postsynaptic potential in the singing interneuron. Current injection in the singing interneuron elicited singing motor activity, even during the air current-evoked inhibitory input from the cercal pathway. The disruptive effects of air stimuli on the fictive singing pattern and the inhibitory response of the singing interneuron point toward the cercal system being involved in initiating avoidance responses in singing crickets, according to the established role of cerci in a predator escape pathway. After abolishing the activity of the cercal system, the timing of natural singing activity was not significantly altered. Our study provides no evidence that self-generated cercal sensory activity has a feedback function for singing motor pattern generation. PMID:26334014

Phase-conjugate holographic lithography based on micromirror array recording.

PubMed

Lim, Yongjun; Hahn, Joonku; Lee, Byoungho

2011-12-01

We present phase-conjugate holographic lithography with a hologram recorded by a digital micromirror device (DMD) and a telecentric lens. In our lithography system, a phase-conjugate hologram is applied instead of conventional masks or reticles to form patterns. This method has the advantage of increasing focus range, and it is applicable to the formation of patterns on fairly uneven surfaces. The hologram pattern is dynamically generated by the DMD, and its resolution is mainly determined by the demagnification of the telecentric lens. We experimentally demonstrate that our holographic lithographic system has a large focus range, and it is feasible to make a large-area hologram by stitching each pattern generated by the DMD without a falling off in resolution. © 2011 Optical Society of America

The study on the effect of pattern density distribution on the STI CMP process

NASA Astrophysics Data System (ADS)

Sub, Yoon Myung; Hian, Bernard Yap Tzen; Fong, Lee It; Anak, Philip Menit; Minhar, Ariffin Bin; Wui, Tan Kim; Kim, Melvin Phua Twang; Jin, Looi Hui; Min, Foo Thai

2017-08-01

The effects of pattern density on CMP characteristics were investigated using specially designed wafer for the characterization of pattern-dependencies in STI CMP [1]. The purpose of this study is to investigate the planarization behavior based on a direct STI CMP used in cerium (CeO2) based slurry system in terms of pattern density variation. The minimal design rule (DR) of 180nm generation technology node was adopted for the mask layout. The mask was successfully applied for evaluation of a cerium (CeO2) abrasive based direct STI CMP process. In this study, we described a planarization behavior of the loading-effects of pattern density variation which were characterized with layout pattern density and pitch variations using masks mentioned above. Furthermore, the characterizing pattern dependent on the variations of the dimensions and spacing features, in thickness remaining after CMP, were analyzed and evaluated. The goal was to establish a concept of library method which will be used to generate design rules reducing the probability of CMP-related failures. Details of the characterization were measured in various layouts showing different pattern density ranges and the effects of pattern density on STI CMP has been discussed in this paper.

Neural constraints on learning.

PubMed

Sadtler, Patrick T; Quick, Kristin M; Golub, Matthew D; Chase, Steven M; Ryu, Stephen I; Tyler-Kabara, Elizabeth C; Yu, Byron M; Batista, Aaron P

2014-08-28

Learning, whether motor, sensory or cognitive, requires networks of neurons to generate new activity patterns. As some behaviours are easier to learn than others, we asked if some neural activity patterns are easier to generate than others. Here we investigate whether an existing network constrains the patterns that a subset of its neurons is capable of exhibiting, and if so, what principles define this constraint. We employed a closed-loop intracortical brain-computer interface learning paradigm in which Rhesus macaques (Macaca mulatta) controlled a computer cursor by modulating neural activity patterns in the primary motor cortex. Using the brain-computer interface paradigm, we could specify and alter how neural activity mapped to cursor velocity. At the start of each session, we observed the characteristic activity patterns of the recorded neural population. The activity of a neural population can be represented in a high-dimensional space (termed the neural space), wherein each dimension corresponds to the activity of one neuron. These characteristic activity patterns comprise a low-dimensional subspace (termed the intrinsic manifold) within the neural space. The intrinsic manifold presumably reflects constraints imposed by the underlying neural circuitry. Here we show that the animals could readily learn to proficiently control the cursor using neural activity patterns that were within the intrinsic manifold. However, animals were less able to learn to proficiently control the cursor using activity patterns that were outside of the intrinsic manifold. These results suggest that the existing structure of a network can shape learning. On a timescale of hours, it seems to be difficult to learn to generate neural activity patterns that are not consistent with the existing network structure. These findings offer a network-level explanation for the observation that we are more readily able to learn new skills when they are related to the skills that we already possess.

Comparative population genetics of a mimicry locus among hybridizing Heliconius butterfly species.

PubMed

Chamberlain, N L; Hill, R I; Baxter, S W; Jiggins, C D; Kronforst, M R

2011-09-01

The comimetic Heliconius butterfly species pair, H. erato and H. melpomene, appear to use a conserved Mendelian switch locus to generate their matching red wing patterns. Here we investigate whether H. cydno and H. pachinus, species closely related to H. melpomene, use this same switch locus to generate their highly divergent red and brown color pattern elements. Using an F2 intercross between H. cydno and H. pachinus, we first map the genomic positions of two novel red/brown wing pattern elements; the G locus, which controls the presence of red vs brown at the base of the ventral wings, and the Br locus, which controls the presence vs absence of a brown oval pattern on the ventral hind wing. The results reveal that the G locus is tightly linked to markers in the genomic interval that controls red wing pattern elements of H. erato and H. melpomene. Br is on the same linkage group but approximately 26 cM away. Next, we analyze fine-scale patterns of genetic differentiation and linkage disequilibrium throughout the G locus candidate interval in H. cydno, H. pachinus and H. melpomene, and find evidence for elevated differentiation between H. cydno and H. pachinus, but no localized signature of association. Overall, these results indicate that the G locus maps to the same interval as the locus controlling red patterning in H. melpomene and H. erato. This, in turn, suggests that the genes controlling red pattern elements may be homologous across Heliconius, supporting the hypothesis that Heliconius butterflies use a limited suite of conserved genetic switch loci to generate both convergent and divergent wing patterns.

Evolution-development congruence in pattern formation dynamics: Bifurcations in gene expression and regulation of networks structures.

PubMed

Kohsokabe, Takahiro; Kaneko, Kunihiko

2016-01-01

Search for possible relationships between phylogeny and ontogeny is important in evolutionary-developmental biology. Here we uncover such relationships by numerical evolution and unveil their origin in terms of dynamical systems theory. By representing developmental dynamics of spatially located cells with gene expression dynamics with cell-to-cell interaction under external morphogen gradient, gene regulation networks are evolved under mutation and selection with the fitness to approach a prescribed spatial pattern of expressed genes. For most numerical evolution experiments, evolution of pattern over generations and development of pattern by an evolved network exhibit remarkable congruence. Both in the evolution and development pattern changes consist of several epochs where stripes are formed in a short time, while for other temporal regimes, pattern hardly changes. In evolution, these quasi-stationary regimes are generations needed to hit relevant mutations, while in development, they are due to some gene expression that varies slowly and controls the pattern change. The morphogenesis is regulated by combinations of feedback or feedforward regulations, where the upstream feedforward network reads the external morphogen gradient, and generates a pattern used as a boundary condition for the later patterns. The ordering from up to downstream is common in evolution and development, while the successive epochal changes in development and evolution are represented as common bifurcations in dynamical-systems theory, which lead to the evolution-development congruence. Mechanism of exceptional violation of the congruence is also unveiled. Our results provide a new look on developmental stages, punctuated equilibrium, developmental bottlenecks, and evolutionary acquisition of novelty in morphogenesis. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution Published by Wiley Periodicals, Inc.

Evolution‐development congruence in pattern formation dynamics: Bifurcations in gene expression and regulation of networks structures

PubMed Central

Kohsokabe, Takahiro

2016-01-01

ABSTRACT Search for possible relationships between phylogeny and ontogeny is important in evolutionary‐developmental biology. Here we uncover such relationships by numerical evolution and unveil their origin in terms of dynamical systems theory. By representing developmental dynamics of spatially located cells with gene expression dynamics with cell‐to‐cell interaction under external morphogen gradient, gene regulation networks are evolved under mutation and selection with the fitness to approach a prescribed spatial pattern of expressed genes. For most numerical evolution experiments, evolution of pattern over generations and development of pattern by an evolved network exhibit remarkable congruence. Both in the evolution and development pattern changes consist of several epochs where stripes are formed in a short time, while for other temporal regimes, pattern hardly changes. In evolution, these quasi‐stationary regimes are generations needed to hit relevant mutations, while in development, they are due to some gene expression that varies slowly and controls the pattern change. The morphogenesis is regulated by combinations of feedback or feedforward regulations, where the upstream feedforward network reads the external morphogen gradient, and generates a pattern used as a boundary condition for the later patterns. The ordering from up to downstream is common in evolution and development, while the successive epochal changes in development and evolution are represented as common bifurcations in dynamical‐systems theory, which lead to the evolution‐development congruence. Mechanism of exceptional violation of the congruence is also unveiled. Our results provide a new look on developmental stages, punctuated equilibrium, developmental bottlenecks, and evolutionary acquisition of novelty in morphogenesis. J. Exp. Zool. (Mol. Dev. Evol.) 326B:61–84, 2016. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution Published by Wiley Periodicals, Inc. PMID:26678220

Local denoising of digital speckle pattern interferometry fringes by multiplicative correlation and weighted smoothing splines.

PubMed

Federico, Alejandro; Kaufmann, Guillermo H

2005-05-10

We evaluate the use of smoothing splines with a weighted roughness measure for local denoising of the correlation fringes produced in digital speckle pattern interferometry. In particular, we also evaluate the performance of the multiplicative correlation operation between two speckle patterns that is proposed as an alternative procedure to generate the correlation fringes. It is shown that the application of a normalization algorithm to the smoothed correlation fringes reduces the excessive bias generated in the previous filtering stage. The evaluation is carried out by use of computer-simulated fringes that are generated for different average speckle sizes and intensities of the reference beam, including decorrelation effects. A comparison with filtering methods based on the continuous wavelet transform is also presented. Finally, the performance of the smoothing method in processing experimental data is illustrated.

Development of dielectrophoresis MEMS device for PC12 cell patterning to elucidate nerve-network generation

NASA Astrophysics Data System (ADS)

Nakamachi, Eiji; Koga, Hirotaka; Morita, Yusuke; Yamamoto, Koji; Sakamoto, Hidetoshi

2018-01-01

We developed a PC12 cell trapping and patterning device by combining the dielectrophoresis (DEP) methodology and the micro electro mechanical systems (MEMS) technology for time-lapse observation of morphological change of nerve network to elucidate the generation mechanism of neural network. We succeeded a neural network generation, which consisted of cell body, axon and dendrites by using tetragonal and hexagonal cell patterning. Further, the time laps observations was carried out to evaluate the axonal extension rate. The axon extended in the channel and reached to the target cell body. We found that the shorter the PC12 cell distance, the less the axonal connection time in both tetragonal and hexagonal structures. After 48 hours culture, a maximum success rate of network formation was 85% in the case of 40 μm distance tetragonal structure.

Nonlinear pattern analysis of ventricular premature beats by mutual information

NASA Technical Reports Server (NTRS)

Osaka, M.; Saitoh, H.; Yokoshima, T.; Kishida, H.; Hayakawa, H.; Cohen, R. J.

1997-01-01

The frequency of ventricular premature beats (VPBs) has been related to the risk of mortality. However, little is known about the temporal pattern of occurrence of VPBs and its relationship to autonomic activity. Hence, we applied a general correlation measure, mutual information, to quantify how VPBs are generated over time. We also used mutual information to determine the correlation between VPB production and heart rate in order to evaluate effects of autonomic activity on VPB production. We examined twenty subjects with more than 3000 VPBs/day and simulated random time series of VPB occurrence. We found that mutual information values could be used to characterize quantitatively the temporal patterns of VPB generation. Our data suggest that VPB production is not random and VPBs generated with a higher value of mutual information may be more greatly affected by autonomic activity.

Membership generation using multilayer neural network

NASA Technical Reports Server (NTRS)

Kim, Jaeseok

1992-01-01

There has been intensive research in neural network applications to pattern recognition problems. Particularly, the back-propagation network has attracted many researchers because of its outstanding performance in pattern recognition applications. In this section, we describe a new method to generate membership functions from training data using a multilayer neural network. The basic idea behind the approach is as follows. The output values of a sigmoid activation function of a neuron bear remarkable resemblance to membership values. Therefore, we can regard the sigmoid activation values as the membership values in fuzzy set theory. Thus, in order to generate class membership values, we first train a suitable multilayer network using a training algorithm such as the back-propagation algorithm. After the training procedure converges, the resulting network can be treated as a membership generation network, where the inputs are feature values and the outputs are membership values in the different classes. This method allows fairly complex membership functions to be generated because the network is highly nonlinear in general. Also, it is to be noted that the membership functions are generated from a classification point of view. For pattern recognition applications, this is highly desirable, although the membership values may not be indicative of the degree of typicality of a feature value in a particular class.

Characterizing Urban Household Waste Generation and Metabolism Considering Community Stratification in a Rapid Urbanizing Area of China

PubMed Central

Xiao, Lishan; Lin, Tao; Chen, Shaohua; Zhang, Guoqin; Ye, Zhilong; Yu, Zhaowu

2015-01-01

The relationship between social stratification and municipal solid waste generation remains uncertain under current rapid urbanization. Based on a multi-object spatial sampling technique, we selected 191 households in a rapidly urbanizing area of Xiamen, China. The selected communities were classified into three types: work-unit, transitional, and commercial communities in the context of housing policy reform in China. Field survey data were used to characterize household waste generation patterns considering community stratification. Our results revealed a disparity in waste generation profiles among different households. The three community types differed with respect to family income, living area, religious affiliation, and homeowner occupation. Income, family structure, and lifestyle caused significant differences in waste generation among work-unit, transitional, and commercial communities, respectively. Urban waste generation patterns are expected to evolve due to accelerating urbanization and associated community transition. A multi-scale integrated analysis of societal and ecosystem metabolism approach was applied to waste metabolism linking it to particular socioeconomic conditions that influence material flows and their evolution. Waste metabolism, both pace and density, was highest for family structure driven patterns, followed by lifestyle and income driven. The results will guide community-specific management policies in rapidly urbanizing areas. PMID:26690056

Insights into the mechanisms underlying colonic motor patterns

PubMed Central

Dinning, Phil G.; Brookes, Simon J.; Costa, Marcello

2016-01-01

Abstract In recent years there have been significant technical and methodological advances in our ability to record the movements of the gastrointestinal tract. This has led to significant changes in our understanding of the different types of motor patterns that exist in the gastrointestinal tract (particularly the large intestine) and in our understanding of the mechanisms underlying their generation. Compared with other tubular smooth muscle organs, a rich variety of motor patterns occurs in the large intestine. This reflects a relatively autonomous nervous system in the gut wall, which has its own unique population of sensory neurons. Although the enteric nervous system can function independently of central neural inputs, under physiological conditions bowel motility is influenced by the CNS: if spinal pathways are disrupted, deficits in motility occur. The combination of high resolution manometry and video imaging has improved our knowledge of the range of motor patterns and provided some insight into the neural and mechanical factors underlying propulsion of contents. The neural circuits responsible for the generation of peristalsis and colonic migrating motor complexes have now been identified to lie within the myenteric plexus and do not require inputs from the mucosa or submucosal ganglia for their generation, but can be modified by their activity. This review will discuss the recent advances in our understanding of the different patterns of propagating motor activity in the large intestine of mammals and how latest technologies have led to major changes in our understanding of the mechanisms underlying their generation. PMID:26990133

Generating Spatiotemporal Joint Torque Patterns from Dynamical Synchronization of Distributed Pattern Generators

PubMed Central

Pitti, Alexandre; Lungarella, Max; Kuniyoshi, Yasuo

2009-01-01

Pattern generators found in the spinal cord are no more seen as simple rhythmic oscillators for motion control. Indeed, they achieve flexible and dynamical coordination in interaction with the body and the environment dynamics giving to rise motor synergies. Discovering the mechanisms underlying the control of motor synergies constitutes an important research question not only for neuroscience but also for robotics: the motors coordination of high dimensional robotic systems is still a drawback and new control methods based on biological solutions may reduce their overall complexity. We propose to model the flexible combination of motor synergies in embodied systems via partial phase synchronization of distributed chaotic systems; for specific coupling strength, chaotic systems are able to phase synchronize their dynamics to the resonant frequencies of one external force. We take advantage of this property to explore and exploit the intrinsic dynamics of one specified embodied system. In two experiments with bipedal walkers, we show how motor synergies emerge when the controllers phase synchronize to the body's dynamics, entraining it to its intrinsic behavioral patterns. This stage is characterized by directed information flow from the sensors to the motors exhibiting the optimal situation when the body dynamics drive the controllers (mutual entrainment). Based on our results, we discuss the relevance of our findings for modeling the modular control of distributed pattern generators exhibited in the spinal cord, and for exploring the motor synergies in robots. PMID:20011216

A visual analytics approach for pattern-recognition in patient-generated data.

PubMed

Feller, Daniel J; Burgermaster, Marissa; Levine, Matthew E; Smaldone, Arlene; Davidson, Patricia G; Albers, David J; Mamykina, Lena

2018-06-13

To develop and test a visual analytics tool to help clinicians identify systematic and clinically meaningful patterns in patient-generated data (PGD) while decreasing perceived information overload. Participatory design was used to develop Glucolyzer, an interactive tool featuring hierarchical clustering and a heatmap visualization to help registered dietitians (RDs) identify associative patterns between blood glucose levels and per-meal macronutrient composition for individuals with type 2 diabetes (T2DM). Ten RDs participated in a within-subjects experiment to compare Glucolyzer to a static logbook format. For each representation, participants had 25 minutes to examine 1 month of diabetes self-monitoring data captured by an individual with T2DM and identify clinically meaningful patterns. We compared the quality and accuracy of the observations generated using each representation. Participants generated 50% more observations when using Glucolyzer (98) than when using the logbook format (64) without any loss in accuracy (69% accuracy vs 62%, respectively, p = .17). Participants identified more observations that included ingredients other than carbohydrates using Glucolyzer (36% vs 16%, p = .027). Fewer RDs reported feelings of information overload using Glucolyzer compared to the logbook format. Study participants displayed variable acceptance of hierarchical clustering. Visual analytics have the potential to mitigate provider concerns about the volume of self-monitoring data. Glucolyzer helped dietitians identify meaningful patterns in self-monitoring data without incurring perceived information overload. Future studies should assess whether similar tools can support clinicians in personalizing behavioral interventions that improve patient outcomes.

Dynamical origin of complex motor patterns

NASA Astrophysics Data System (ADS)

Alonso, L. M.; Alliende, J. A.; Mindlin, G. B.

2010-11-01

Behavior emerges as the nervous system generates motor patterns in charge of driving a peripheral biomechanical device. For several cases in the animal kingdom, it has been identified that the motor patterns used in order to accomplish a diversity of tasks are the different solutions of a simple, low dimensional nonlinear dynamical system. Yet, motor patterns emerge from the interaction of an enormous number of individual dynamical units. In this work, we study the dynamics of the average activity of a large set of coupled excitable units which are periodically forced. We show that low dimensional, yet non trivial dynamics emerges. As a case study, we analyze the air sac pressure patterns used by domestic canaries during song, which consists of a succession of repetitions of different syllable types. We show that the pressure patterns used to generate different syllables can be approximated by the solutions of the investigated model. In this way, we are capable of integrating different description scales of our problem.

Stress adapted embroidered meshes with a graded pattern design for abdominal wall hernia repair

NASA Astrophysics Data System (ADS)

Hahn, J.; Bittrich, L.; Breier, A.; Spickenheuer, A.

2017-10-01

Abdominal wall hernias are one of the most relevant injuries of the digestive system with 25 million patients in 2013. Surgery is recommended primarily using allogenic non-absorbable wrap-knitted meshes. These meshes have in common that their stress-strain behaviour is not adapted to the anisotropic behaviour of native abdominal wall tissue. The ideal mesh should possess an adequate mechanical behaviour and a suitable porosity at the same time. An alternative fabrication method to wrap-knitting is the embroidery technology with a high flexibility in pattern design and adaption of mechanical properties. In this study, a pattern generator was created for pattern designs consisting of a base and a reinforcement pattern. The embroidered mesh structures demonstrated different structural and mechanical characteristics. Additionally, the investigation of the mechanical properties exhibited an anisotropic mechanical behaviour for the embroidered meshes. As a result, the investigated pattern generator and the embroidery technology allow the production of stress adapted mesh structures that are a promising approach for hernia reconstruction.

Parasol cell mosaics are unlikely to drive the formation of structured orientation maps in primary visual cortex.

PubMed

Hore, Victoria R A; Troy, John B; Eglen, Stephen J

2012-11-01

The receptive fields of on- and off-center parasol cell mosaics independently tile the retina to ensure efficient sampling of visual space. A recent theoretical model represented the on- and off-center mosaics by noisy hexagonal lattices of slightly different density. When the two lattices are overlaid, long-range Moiré interference patterns are generated. These Moiré interference patterns have been suggested to drive the formation of highly structured orientation maps in visual cortex. Here, we show that noisy hexagonal lattices do not capture the spatial statistics of parasol cell mosaics. An alternative model based upon local exclusion zones, termed as the pairwise interaction point process (PIPP) model, generates patterns that are statistically indistinguishable from parasol cell mosaics. A key difference between the PIPP model and the hexagonal lattice model is that the PIPP model does not generate Moiré interference patterns, and hence stimulated orientation maps do not show any hexagonal structure. Finally, we estimate the spatial extent of spatial correlations in parasol cell mosaics to be only 200-350 μm, far less than that required to generate Moiré interference. We conclude that parasol cell mosaics are too disordered to drive the formation of highly structured orientation maps in visual cortex.

Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution

PubMed Central

Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I.; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

2016-01-01

This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented. PMID:27516737

Three ancient hormonal cues co-ordinate shoot branching in a moss.

PubMed

Coudert, Yoan; Palubicki, Wojtek; Ljung, Karin; Novak, Ondrej; Leyser, Ottoline; Harrison, C Jill

2015-03-25

Shoot branching is a primary contributor to plant architecture, evolving independently in flowering plant sporophytes and moss gametophytes. Mechanistic understanding of branching is largely limited to flowering plants such as Arabidopsis, which have a recent evolutionary origin. We show that in gametophytic shoots of Physcomitrella, lateral branches arise by re-specification of epidermal cells into branch initials. A simple model co-ordinating the activity of leafy shoot tips can account for branching patterns, and three known and ancient hormonal regulators of sporophytic branching interact to generate the branching pattern- auxin, cytokinin and strigolactone. The mode of auxin transport required in branch patterning is a key divergence point from known sporophytic pathways. Although PIN-mediated basipetal auxin transport regulates branching patterns in flowering plants, this is not so in Physcomitrella, where bi-directional transport is required to generate realistic branching patterns. Experiments with callose synthesis inhibitors suggest plasmodesmal connectivity as a potential mechanism for transport.

Computer Generated Diffraction Patterns Of Rough Surfaces

NASA Astrophysics Data System (ADS)

Rakels, Jan H.

1989-03-01

It is generally accepted, that optical methods are the most promising for the in-process measurement of surface finish. These methods have the advantages of being non-contacting and fast data acquisition. In the Micro-Engineering Centre at the University of Warwick, an optical sensor has been devised which can measure the rms roughness, slope and wavelength of turned and precision ground surfaces. The operation of this device is based upon the Kirchhoff-Fresnel diffraction integral. Application of this theory to ideal turned surfaces is straightforward, and indeed the theoretically calculated diffraction patterns are in close agreement with patterns produced by an actual optical instrument. Since it is mathematically difficult to introduce real surface profiles into the diffraction integral, a computer program has been devised, which simulates the operation of the optical sensor. The program produces a diffraction pattern as a graphical output. Comparison between computer generated and actual diffraction patterns of the same surfaces show a high correlation.

Light-Directed Particle Patterning by Evaporative Optical Marangoni Assembly.

PubMed

Varanakkottu, Subramanyan Namboodiri; Anyfantakis, Manos; Morel, Mathieu; Rudiuk, Sergii; Baigl, Damien

2016-01-13

Controlled particle deposition on surfaces is crucial for both exploiting collective properties of particles and their integration into devices. Most available methods depend on intrinsic properties of either the substrate or the particles to be deposited making them difficult to apply to complex, naturally occurring or industrial formulations. Here we describe a new strategy to pattern particles from an evaporating drop, regardless of inherent particle characteristics and suspension composition. We use light to generate Marangoni surface stresses resulting in flow patterns that accumulate particles at predefined positions. Using projected images, we generate a broad variety of complex patterns, including multiple spots, lines and letters. Strikingly, this method, which we call evaporative optical Marangoni assembly (eOMA), allows us to pattern particles regardless of their size or surface properties, in model suspensions as well as in complex, real-world formulations such as commercial coffee.

Generation and dynamics of optical beams with polarization singularities.

PubMed

Cardano, Filippo; Karimi, Ebrahim; Marrucci, Lorenzo; de Lisio, Corrado; Santamato, Enrico

2013-04-08

We present a convenient method to generate vector beams of light having polarization singularities on their axis, via partial spin-to-orbital angular momentum conversion in a suitably patterned liquid crystal cell. The resulting polarization patterns exhibit a C-point on the beam axis and an L-line loop around it, and may have different geometrical structures such as "lemon", "star", and "spiral". Our generation method allows us to control the radius of L-line loop around the central C-point. Moreover, we investigate the free-air propagation of these fields across a Rayleigh range.

Cell assembly sequences arising from spike threshold adaptation keep track of time in the hippocampus

PubMed Central

Itskov, Vladimir; Curto, Carina; Pastalkova, Eva; Buzsáki, György

2011-01-01

Hippocampal neurons can display reliable and long-lasting sequences of transient firing patterns, even in the absence of changing external stimuli. We suggest that time-keeping is an important function of these sequences, and propose a network mechanism for their generation. We show that sequences of neuronal assemblies recorded from rat hippocampal CA1 pyramidal cells can reliably predict elapsed time (15-20 sec) during wheel running with a precision of 0.5sec. In addition, we demonstrate the generation of multiple reliable, long-lasting sequences in a recurrent network model. These sequences are generated in the presence of noisy, unstructured inputs to the network, mimicking stationary sensory input. Identical initial conditions generate similar sequences, whereas different initial conditions give rise to distinct sequences. The key ingredients responsible for sequence generation in the model are threshold-adaptation and a Mexican-hat-like pattern of connectivity among pyramidal cells. This pattern may arise from recurrent systems such as the hippocampal CA3 region or the entorhinal cortex. We hypothesize that mechanisms that evolved for spatial navigation also support tracking of elapsed time in behaviorally relevant contexts. PMID:21414904

Inducing any virtual two-dimensional movement in humans by applying muscle tendon vibration.

PubMed

Roll, Jean-Pierre; Albert, Frédéric; Thyrion, Chloé; Ribot-Ciscar, Edith; Bergenheim, Mikael; Mattei, Benjamin

2009-02-01

In humans, tendon vibration evokes illusory sensation of movement. We developed a model mimicking the muscle afferent patterns corresponding to any two-dimensional movement and checked its validity by inducing writing illusory movements through specific sets of muscle vibrators. Three kinds of illusory movements were compared. The first was induced by vibration patterns copying the responses of muscle spindle afferents previously recorded by microneurography during imposed ankle movements. The two others were generated by the model. Sixteen different vibratory patterns were applied to 20 motionless volunteers in the absence of vision. After each vibration sequence, the participants were asked to name the corresponding graphic symbol and then to reproduce the illusory movement perceived. Results showed that the afferent patterns generated by the model were very similar to those recorded microneurographically during actual ankle movements (r=0.82). The model was also very efficient for generating afferent response patterns at the wrist level, if the preferred sensory directions of the wrist muscle groups were first specified. Using recorded and modeled proprioceptive patterns to pilot sets of vibrators placed at the ankle or wrist levels evoked similar illusory movements, which were correctly identified by the participants in three quarters of the trials. Our proprioceptive model, based on neurosensory data recorded in behaving humans, should then be a useful tool in fields of research such as sensorimotor learning, rehabilitation, and virtual reality.

Light-induced quantitative microprinting of biomolecules

NASA Astrophysics Data System (ADS)

Strale, Pierre-Olivier; Azioune, Ammar; Bugnicourt, Ghislain; Lecomte, Yohan; Chahid, Makhlad; Studer, Vincent

2017-02-01

Printing of biomolecules on substrates has developed tremendously in the past few years. The existing methods either rely on slow serial writing processes or on parallelized photolithographic techniques where cumbersome mask alignment procedures usually impair the ability to generate multi-protein patterns. We recently developed a new technology allowing for high resolution multi protein micro-patterning. This technology named "Light-Induced Molecular Adsorption of Proteins (LIMAP)" is based on a water-soluble photo-initiator able to reverse the antifouling property of polymer brushes when exposed to UV light. We developed a wide-field pattern projection system based on a DMD coupled to a conventional microscope which permits to generate arbitrary grayscale patterns of UV light at the micron scale. Interestingly, the density of adsorbed molecules scales with the dose of UV light thus allowing the quantitative patterning of biomolecules. The very low non specific background of biomolecules outside of the UV-exposed areas allows for the sequential printing of multiple proteins without alignment procedures. Protein patterns ranging from 500 nm up to 1 mm can be performed within seconds, as well as gradients of arbitrary shapes. The range of applications of the LIMAP approach extends from the single molecule up to the multicellular scale with an exquisite control over local protein density. We show that it can be used to generate complex protein landscapes useful to study protein-protein, cell-cell and cell-matrix interactions.

Pattern database applications from design to manufacturing

NASA Astrophysics Data System (ADS)

Zhuang, Linda; Zhu, Annie; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh

2017-03-01

Pattern-based approaches are becoming more common and popular as the industry moves to advanced technology nodes. At the beginning of a new technology node, a library of process weak point patterns for physical and electrical verification are starting to build up and used to prevent known hotspots from re-occurring on new designs. Then the pattern set is expanded to create test keys for process development in order to verify the manufacturing capability and precheck new tape-out designs for any potential yield detractors. With the database growing, the adoption of pattern-based approaches has expanded from design flows to technology development and then needed for mass-production purposes. This paper will present the complete downstream working flows of a design pattern database(PDB). This pattern-based data analysis flow covers different applications across different functional teams from generating enhancement kits to improving design manufacturability, populating new testing design data based on previous-learning, generating analysis data to improve mass-production efficiency and manufacturing equipment in-line control to check machine status consistency across different fab sites.

Linking Substance Use and Problem Behavior across Three Generations

ERIC Educational Resources Information Center

Bailey, Jennifer A.; Hill, Karl G.; Oesterle, Sabrina; Hawkins, J. David

2006-01-01

This study examined patterns of between-generation continuity in substance use from generation 1 (G1) parents to generation 2 (G2) adolescents and from G2 adult substance use and G1 substance use to generation 3 (G3) problem behavior in childhood. Structural equation modeling of prospective, longitudinal data from 808 participants, their parents,…

A weak pattern random creation and scoring method for lithography process tuning

NASA Astrophysics Data System (ADS)

Zhang, Meili; Deng, Guogui; Wang, Mudan; Yu, Shirui; Hu, Xinyi; Du, Chunshan; Wan, Qijian; Liu, Zhengfang; Gao, Gensheng; Kabeel, Aliaa; Madkour, Kareem; ElManhawy, Wael; Kwan, Joe

2018-03-01

As the IC technology node moves forward, critical dimension becomes smaller and smaller, which brings huge challenge to IC manufacturing. Lithography is one of the most important steps during the whole manufacturing process and litho hotspots become a big source of yield detractors. Thus tuning lithographic recipes to cover a big range of litho hotspots is very essential to yield enhancing. During early technology developing stage, foundries only have limited customer layout data for recipe tuning. So collecting enough patterns is significant for process optimization. After accumulating enough patterns, a general way to treat them is not precise and applicable. Instead, an approach to scoring these patterns could provide a priority and reference to address different patterns more effectively. For example, the weakest group of patterns could be applied the most limited specs to ensure process robustness. This paper presents a new method of creation of real design alike patterns of multiple layers based on design rules using Layout Schema Generator (LSG) utility and a pattern scoring flow using Litho-friendly Design (LFD) and Pattern Matching. Through LSG, plenty of new unknown patterns could be created for further exploration. Then, litho simulation through LFD and topological matches by using Pattern Matching is applied on the output patterns of LSG. Finally, lithographical severity, printability properties and topological distribution of every pattern are collected. After a statistical analysis of pattern data, every pattern is given a relative score representing the pattern's yield detracting level. By sorting the output pattern score tables, weak patterns could be filtered out for further research and process tuning. This pattern generation and scoring flow is demonstrated on 28nm logic technology node. A weak pattern library is created and scored to help improve recipe coverage of litho hotspots and enhance the reliability of process.

Perturbations of Respiratory Rhythm and Pattern by Disrupting Synaptic Inhibition within Pre-Bötzinger and Bötzinger Complexes123

PubMed Central

Koizumi, Hidehiko; Mosher, Bryan; Tariq, Mohammad F.; Zhang, Ruli; Molkov, Yaroslav I.

2016-01-01

The pre-Bötzinger (pre-BötC) and Bötzinger (BötC) complexes are the brainstem compartments containing interneurons considered to be critically involved in generating respiratory rhythm and motor pattern in mammals. Current models postulate that both generation of the rhythm and coordination of the inspiratory-expiratory pattern involve inhibitory synaptic interactions within and between these regions. Both regions contain glycinergic and GABAergic neurons, and rhythmically active neurons in these regions receive appropriately coordinated phasic inhibition necessary for generation of the normal three-phase respiratory pattern. However, recent experiments attempting to disrupt glycinergic and GABAergic postsynaptic inhibition in the pre-BötC and BötC in adult rats in vivo have questioned the critical role of synaptic inhibition in these regions, as well as the importance of the BötC, which contradicts previous physiological and pharmacological studies. To further evaluate the roles of synaptic inhibition and the BötC, we bilaterally microinjected the GABAA receptor antagonist gabazine and glycinergic receptor antagonist strychnine into the pre-BötC or BötC in anesthetized adult rats in vivo and in perfused in situ brainstem–spinal cord preparations from juvenile rats. Muscimol was microinjected to suppress neuronal activity in the pre-BötC or BötC. In both preparations, disrupting inhibition within pre-BötC or BötC caused major site-specific perturbations of the rhythm and disrupted the three-phase motor pattern, in some experiments terminating rhythmic motor output. Suppressing BötC activity also potently disturbed the rhythm and motor pattern. We conclude that inhibitory circuit interactions within and between the pre-BötC and BötC critically regulate rhythmogenesis and are required for normal respiratory motor pattern generation. PMID:27200412

Contributions of ignitions, fuels, and weather to the spatial patterns of burn probability of a boreal landscape

Treesearch

Marc-Andre Parisien; Sean A. Parks; Carol Miller; Meg A. Krawchuck; Mark Heathcott; Max A. Moritz

2011-01-01

The spatial pattern of fire observed across boreal landscapes is the outcome of complex interactions among components of the fire environment. We investigated how the naturally occurring patterns of ignitions, fuels, and weather generate spatial pattern of burn probability (BP) in a large and highly fireprone boreal landscape of western Canada, Wood Buffalo National...

PatternCoder: A Programming Support Tool for Learning Binary Class Associations and Design Patterns

ERIC Educational Resources Information Center

Paterson, J. H.; Cheng, K. F.; Haddow, J.

2009-01-01

PatternCoder is a software tool to aid student understanding of class associations. It has a wizard-based interface which allows students to select an appropriate binary class association or design pattern for a given problem. Java code is then generated which allows students to explore the way in which the class associations are implemented in a…

Preparation of Iridescent 2D Photonic Crystals by Using a Mussel-Inspired Spatial Patterning of ZIF-8 with Potential Applications in Optical Switch and Chemical Sensor.

PubMed

Razmjou, Amir; Asadnia, Mohsen; Ghaebi, Omid; Yang, Hao-Cheng; Ebrahimi Warkiani, Majid; Hou, Jingwei; Chen, Vicki

2017-11-01

In this work, spatial patterning of a thin, dense, zeolitic imidazolate framework (ZIF-8) pattern was generated using photolithography and nanoscale (60 nm) dopamine coating. A bioinspired, unique, reversible, two-color iridescent pattern can be easily obtained for potential applications in sensing and photonics.

Stochastic nonlinear dynamics pattern formation and growth models

PubMed Central

Yaroslavsky, Leonid P

2007-01-01

Stochastic evolutionary growth and pattern formation models are treated in a unified way in terms of algorithmic models of nonlinear dynamic systems with feedback built of a standard set of signal processing units. A number of concrete models is described and illustrated by numerous examples of artificially generated patterns that closely imitate wide variety of patterns found in the nature. PMID:17908341

High-speed high-accuracy three-dimensional shape measurement using digital binary defocusing method versus sinusoidal method

NASA Astrophysics Data System (ADS)

Hyun, Jae-Sang; Li, Beiwen; Zhang, Song

2017-07-01

This paper presents our research findings on high-speed high-accuracy three-dimensional shape measurement using digital light processing (DLP) technologies. In particular, we compare two different sinusoidal fringe generation techniques using the DLP projection devices: direct projection of computer-generated 8-bit sinusoidal patterns (a.k.a., the sinusoidal method), and the creation of sinusoidal patterns by defocusing binary patterns (a.k.a., the binary defocusing method). This paper mainly examines their performance on high-accuracy measurement applications under precisely controlled settings. Two different projection systems were tested in this study: a commercially available inexpensive projector and the DLP development kit. Experimental results demonstrated that the binary defocusing method always outperforms the sinusoidal method if a sufficient number of phase-shifted fringe patterns can be used.

High-speed 3D imaging using digital binary defocusing method vs sinusoidal method

NASA Astrophysics Data System (ADS)

Zhang, Song; Hyun, Jae-Sang; Li, Beiwen

2017-02-01

This paper presents our research findings on high-speed 3D imaging using digital light processing (DLP) technologies. In particular, we compare two different sinusoidal fringe generation techniques using the DLP projection devices: direct projection of 8-bit computer generated sinusoidal patterns (a.k.a, the sinusoidal method), and the creation of sinusoidal patterns by defocusing binary patterns (a.k.a., the binary defocusing method). This paper mainly examines their performance on high-accuracy measurement applications under precisely controlled settings. Two different projection systems were tested in this study: the commercially available inexpensive projector, and the DLP development kit. Experimental results demonstrated that the binary defocusing method always outperforms the sinusoidal method if a sufficient number of phase-shifted fringe patterns can be used.

Decompositions of injection patterns for nodal flow allocation in renewable electricity networks

NASA Astrophysics Data System (ADS)

Schäfer, Mirko; Tranberg, Bo; Hempel, Sabrina; Schramm, Stefan; Greiner, Martin

2017-08-01

The large-scale integration of fluctuating renewable power generation represents a challenge to the technical and economical design of a sustainable future electricity system. In this context, the increasing significance of long-range power transmission calls for innovative methods to understand the emerging complex flow patterns and to integrate price signals about the respective infrastructure needs into the energy market design. We introduce a decomposition method of injection patterns. Contrary to standard flow tracing approaches, it provides nodal allocations of link flows and costs in electricity networks by decomposing the network injection pattern into market-inspired elementary import/export building blocks. We apply the new approach to a simplified data-driven model of a European electricity grid with a high share of renewable wind and solar power generation.

Programmable assembly of pressure sensors using pattern-forming bacteria.

PubMed

Cao, Yangxiaolu; Feng, Yaying; Ryser, Marc D; Zhu, Kui; Herschlag, Gregory; Cao, Changyong; Marusak, Katherine; Zauscher, Stefan; You, Lingchong

2017-11-01

Biological systems can generate microstructured materials that combine organic and inorganic components and possess diverse physical and chemical properties. However, these natural processes in materials fabrication are not readily programmable. Here, we use a synthetic-biology approach to assemble patterned materials. We demonstrate programmable fabrication of three-dimensional (3D) materials by printing engineered self-patterning bacteria on permeable membranes that serve as a structural scaffold. Application of gold nanoparticles to the colonies creates hybrid organic-inorganic dome structures. The dynamics of the dome structures' response to pressure is determined by their geometry (colony size, dome height, and pattern), which is easily modified by varying the properties of the membrane (e.g., pore size and hydrophobicity). We generate resettable pressure sensors that process signals in response to varying pressure intensity and duration.

Analysis of communication in the standard versus automated aircraft

NASA Technical Reports Server (NTRS)

Veinott, Elizabeth S.; Irwin, Cheryl M.

1993-01-01

Past research has shown crew communication patterns to be associated with overall crew performance, recent flight experience together, low-and high-error crew performance and personality variables. However, differences in communication patterns as a function of aircraft type and level of aircraft automation have not been fully addressed. Crew communications from ten MD-88 and twelve DC-9 crews were obtained during a full-mission simulation. In addition to large differences in overall amount of communication during the normal and abnormal phases of flight (DC-9 crews generating less speech than MD-88 crews), differences in specific speech categories were also found. Log-linear analyses also generated speaker-response patterns related to each aircraft type, although in future analyses these patterns will need to account for variations due to crew performance.

Huygens-Fresnel Acoustic Interference and the Development of Robust Time-Averaged Patterns from Traveling Surface Acoustic Waves

NASA Astrophysics Data System (ADS)

Devendran, Citsabehsan; Collins, David J.; Ai, Ye; Neild, Adrian

2017-04-01

Periodic pattern generation using time-averaged acoustic forces conventionally requires the intersection of counterpropagating wave fields, where suspended micro-objects in a microfluidic system collect along force potential minimizing nodal or antinodal lines. Whereas this effect typically requires either multiple transducer elements or whole channel resonance, we report the generation of scalable periodic patterning positions without either of these conditions. A single propagating surface acoustic wave interacts with the proximal channel wall to produce a knife-edge effect according to the Huygens-Fresnel principle, where these cylindrically propagating waves interfere with classical wave fronts emanating from the substrate. We simulate these conditions and describe a model that accurately predicts the lateral spacing of these positions in a robust and novel approach to acoustic patterning.

Extreme ultraviolet resist materials for sub-7 nm patterning.

PubMed

Li, Li; Liu, Xuan; Pal, Shyam; Wang, Shulan; Ober, Christopher K; Giannelis, Emmanuel P

2017-08-14

Continuous ongoing development of dense integrated circuits requires significant advancements in nanoscale patterning technology. As a key process in semiconductor high volume manufacturing (HVM), high resolution lithography is crucial in keeping with Moore's law. Currently, lithography technology for the sub-7 nm node and beyond has been actively investigated approaching atomic level patterning. EUV technology is now considered to be a potential alternative to HVM for replacing in some cases ArF immersion technology combined with multi-patterning. Development of innovative resist materials will be required to improve advanced fabrication strategies. In this article, advancements in novel resist materials are reviewed to identify design criteria for establishment of a next generation resist platform. Development strategies and the challenges in next generation resist materials are summarized and discussed.

Fast computation of hologram patterns of a 3D object using run-length encoding and novel look-up table methods.

PubMed

Kim, Seung-Cheol; Kim, Eun-Soo

2009-02-20

In this paper we propose a new approach for fast generation of computer-generated holograms (CGHs) of a 3D object by using the run-length encoding (RLE) and the novel look-up table (N-LUT) methods. With the RLE method, spatially redundant data of a 3D object are extracted and regrouped into the N-point redundancy map according to the number of the adjacent object points having the same 3D value. Based on this redundancy map, N-point principle fringe patterns (PFPs) are newly calculated by using the 1-point PFP of the N-LUT, and the CGH pattern for the 3D object is generated with these N-point PFPs. In this approach, object points to be involved in calculation of the CGH pattern can be dramatically reduced and, as a result, an increase of computational speed can be obtained. Some experiments with a test 3D object are carried out and the results are compared to those of the conventional methods.

Reconstructing the spatial pattern of trees from routine stand examination measurements

USGS Publications Warehouse

Hanus, M.L.; Hann, D.W.; Marshall, D.D.

1998-01-01

Reconstruction of the spatial pattern of trees is important for the accurate visual display of unmapped stands. The proposed process for generating the spatial pattern is a nonsimple sequential inhibition process, with the inhibition zone proportionate to the scaled maximum crown width of an open-grown tree of the same species and same diameter at breast height as the subject tree. The results of this coordinate generation procedure are compared with mapped stem data from nine natural stands of Douglas-fir at two ages by the use of a transformed Ripley's K(d) function. The results of this comparison indicate that the proposed method, based on complete tree lists, successfully replicated the spatial patterns of the trees in all nine stands at both ages and over the range of distances examined. On the basis of these findings and the procedure's ability to model effects through time, the nonsimple sequential inhibition process has been chosen to generate tree coordinates in the VIZ4ST computer program for displaying forest stand structure in naturally regenerated young Douglas-fir stands. For. Sci.

FPGA implementation of a configurable neuromorphic CPG-based locomotion controller.

PubMed

Barron-Zambrano, Jose Hugo; Torres-Huitzil, Cesar

2013-09-01

Neuromorphic engineering is a discipline devoted to the design and development of computational hardware that mimics the characteristics and capabilities of neuro-biological systems. In recent years, neuromorphic hardware systems have been implemented using a hybrid approach incorporating digital hardware so as to provide flexibility and scalability at the cost of power efficiency and some biological realism. This paper proposes an FPGA-based neuromorphic-like embedded system on a chip to generate locomotion patterns of periodic rhythmic movements inspired by Central Pattern Generators (CPGs). The proposed implementation follows a top-down approach where modularity and hierarchy are two desirable features. The locomotion controller is based on CPG models to produce rhythmic locomotion patterns or gaits for legged robots such as quadrupeds and hexapods. The architecture is configurable and scalable for robots with either different morphologies or different degrees of freedom (DOFs). Experiments performed on a real robot are presented and discussed. The obtained results demonstrate that the CPG-based controller provides the necessary flexibility to generate different rhythmic patterns at run-time suitable for adaptable locomotion. Copyright © 2013 Elsevier Ltd. All rights reserved.

A living mesoscopic cellular automaton made of skin scales.

PubMed

Manukyan, Liana; Montandon, Sophie A; Fofonjka, Anamarija; Smirnov, Stanislav; Milinkovitch, Michel C

2017-04-12

In vertebrates, skin colour patterns emerge from nonlinear dynamical microscopic systems of cell interactions. Here we show that in ocellated lizards a quasi-hexagonal lattice of skin scales, rather than individual chromatophore cells, establishes a green and black labyrinthine pattern of skin colour. We analysed time series of lizard scale colour dynamics over four years of their development and demonstrate that this pattern is produced by a cellular automaton (a grid of elements whose states are iterated according to a set of rules based on the states of neighbouring elements) that dynamically computes the colour states of individual mesoscopic skin scales to produce the corresponding macroscopic colour pattern. Using numerical simulations and mathematical derivation, we identify how a discrete von Neumann cellular automaton emerges from a continuous Turing reaction-diffusion system. Skin thickness variation generated by three-dimensional morphogenesis of skin scales causes the underlying reaction-diffusion dynamics to separate into microscopic and mesoscopic spatial scales, the latter generating a cellular automaton. Our study indicates that cellular automata are not merely abstract computational systems, but can directly correspond to processes generated by biological evolution.

TauG-guidance of transients in expressive musical performance.

PubMed

Schogler, Benjaman; Pepping, Gert-Jan; Lee, David N

2008-08-01

The sounds in expressive musical performance, and the movements that produce them, offer insight into temporal patterns in the brain that generate expression. To gain understanding of these brain patterns, we analyzed two types of transient sounds, and the movements that produced them, during a vocal duet and a bass solo. The transient sounds studied were inter-tone f (0)(t)-glides (the continuous change in fundamental frequency, f (0)(t), when gliding from one tone to the next), and attack intensity-glides (the continuous rise in sound intensity when attacking, or initiating, a tone). The temporal patterns of the inter-tone f (0)(t)-glides and attack intensity-glides, and of the movements producing them, all conformed to the mathematical function, tau (G)(t) (called tauG), predicted by General Tau Theory, and assumed to be generated in the brain. The values of the parameters of the tau (G)(t) function were modulated by the performers when they modulated musical expression. Thus the tau (G)(t) function appears to be a fundamental of brain activity entailed in the generation of expressive temporal patterns of movement and sound.

Virus-based surface patterning of biological molecules, probes, and inorganic materials.

PubMed

Ahn, Suji; Jeon, Seongho; Kwak, Eun-A; Kim, Jong-Man; Jaworski, Justyn

2014-10-01

An essential requirement for continued technological advancement in many areas of biology, physics, chemistry, and materials science is the growing need to generate custom patterned materials. Building from recent achievements in the site-specific modification of virus for covalent surface tethering, we show in this work that stable 2D virus patterns can be generated in custom geometries over large area glass surfaces to yield templates of biological, biochemical, and inorganic materials in high density. As a nanomaterial building block, filamentous viruses have been extensively used in recent years to produce materials with interesting properties, owing to their ease of genetic and chemical modification. By utilizing un-natural amino acids generated at specific locations on the filamentous fd bacteriophage protein coat, surface immobilization is carried out on APTES patterned glass resulting in precise geometries of covalently linked virus material. This technique facilitated the surface display of a high density of virus that were labeled with biomolecules, fluorescent probes, and gold nanoparticles, thereby opening the possibility of integrating virus as functional components for surface engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

A living mesoscopic cellular automaton made of skin scales

NASA Astrophysics Data System (ADS)

Manukyan, Liana; Montandon, Sophie A.; Fofonjka, Anamarija; Smirnov, Stanislav; Milinkovitch, Michel C.

2017-04-01

In vertebrates, skin colour patterns emerge from nonlinear dynamical microscopic systems of cell interactions. Here we show that in ocellated lizards a quasi-hexagonal lattice of skin scales, rather than individual chromatophore cells, establishes a green and black labyrinthine pattern of skin colour. We analysed time series of lizard scale colour dynamics over four years of their development and demonstrate that this pattern is produced by a cellular automaton (a grid of elements whose states are iterated according to a set of rules based on the states of neighbouring elements) that dynamically computes the colour states of individual mesoscopic skin scales to produce the corresponding macroscopic colour pattern. Using numerical simulations and mathematical derivation, we identify how a discrete von Neumann cellular automaton emerges from a continuous Turing reaction-diffusion system. Skin thickness variation generated by three-dimensional morphogenesis of skin scales causes the underlying reaction-diffusion dynamics to separate into microscopic and mesoscopic spatial scales, the latter generating a cellular automaton. Our study indicates that cellular automata are not merely abstract computational systems, but can directly correspond to processes generated by biological evolution.

Cultured embryonic non-innervated mouse muzzle is capable of generating a whisker pattern.

PubMed

Andrés, F L; Van Der Loos, H

1983-01-01

The whisker pattern on the muzzle of the mouse is mapped in the contralateral parietal neocortex, each whisker follicle projecting to its own multineuronal unit ('barrel'). To determine the role, if any, of the peripheral innervation in the establishment of the vibrissal array, we cultured non-innervated prospective whiskerpads from 9- and 10-day-old embryos, mostly on chorioallantoic membrane. The results show that skin, alone, is capable of generating the whisker pattern, thus adducing a strong argument for the hypothesis that the central brain maps have their origin in the periphery. Copyright © 1983. Published by Elsevier Ltd.

Different patterns of language activation in post-stroke aphasia are detected by overt and covert versions of the verb generation fMRI task

PubMed Central

Allendorfer, Jane B.; Kissela, Brett M.; Holland, Scott K.; Szaflarski, Jerzy P.

2012-01-01

Summary Background Post-stroke language functions depend on the relative contributions of the dominant and non-dominant hemispheres. Thus, we aimed to identify the neural correlates of overt and covert verb generation in adult post-stroke aphasia. Material/Methods Sixteen aphasic LMCA stroke patients (SPs) and 32 healthy controls (HCs) underwent language testing followed by fMRI while performing an overt event-related verb generation task (ER-VGT) isolating activations related to noun-verb semantic processing or to articulation and auditory processing, and a covert block design verb generation task (BD-VGT). Results BD-VGT activation patterns were consistent with previous studies, while ER-VGT showed different patterns in SPs relative to HCs including less left-hemispheric involvement during semantic processing and predominantly right-sided activation related to articulation and auditory processing. ER-VGT intra-scanner performance was positively associated with activation during semantic associations in the left middle temporal gyrus for HCs (p=0.031) and left middle frontal gyrus for SPs (p=0.042). Increased activation in superior frontal/cingulate gyri was associated with better intra-scanner performance (p=0.020). Lesion size negatively impacted verbal fluency tested with Controlled Oral Word Association Test (p=0.0092) and the Semantic Fluency Test (p=0.033) and trended towards a negative association with verb generation performance on the event-related verb generation task (p=0.081). Conclusions Greater retention of pre-stroke language skills is associated with greater involvement of the left hemisphere with different cortical recruitment patterns observed in SPs versus HCs. Post-stroke verbal fluency may depend more upon the structural and functional integrity of the dominant left hemisphere language network rather than the shift to contralateral homologues. PMID:22367124

Patterns of the cosmic microwave background from evolving string networks

NASA Technical Reports Server (NTRS)

Bouchet, Francois R.; Bennett, David P.; Stebbins, Albert

1988-01-01

A network of cosmic strings generated in the early universe may still exist today. As the strings move across the sky, they produce, by gravitational lensing, a characteristic pattern of anisotropies in the temperature of the cosmic microwave background. The observed absence of such anisotropies places constraints on theories in which galaxy formation is seeded by strings, but it is anticipated that the next generation of experiments will detect them.

Generating Textures for Arbitrary Surfaces Using Reaction-Diffusion

DTIC Science & Technology

1990-01-01

Review and Classification," Computer Aided Design, Vol. 20, No. 1, pp. 27-38 (January/February 1988). [ Hubel and Wiesel 79] Hubel , David H. and...columns found in mammals [ Hubel and Wiesel 791. Complex Patterns This section shows how we can generate more complex patterns using reaction-diffusion by... Torsten N. Wiesel , "Brain Mechanisms of Vision," Scientific American, Vol. 241, No. 3, pp. 150-162 (September 1979). [Hunding 90] Hunding, Axel, Stuart A

Temporal sequence learning in winner-take-all networks of spiking neurons demonstrated in a brain-based device.

PubMed

McKinstry, Jeffrey L; Edelman, Gerald M

2013-01-01

Animal behavior often involves a temporally ordered sequence of actions learned from experience. Here we describe simulations of interconnected networks of spiking neurons that learn to generate patterns of activity in correct temporal order. The simulation consists of large-scale networks of thousands of excitatory and inhibitory neurons that exhibit short-term synaptic plasticity and spike-timing dependent synaptic plasticity. The neural architecture within each area is arranged to evoke winner-take-all (WTA) patterns of neural activity that persist for tens of milliseconds. In order to generate and switch between consecutive firing patterns in correct temporal order, a reentrant exchange of signals between these areas was necessary. To demonstrate the capacity of this arrangement, we used the simulation to train a brain-based device responding to visual input by autonomously generating temporal sequences of motor actions.

Generation of Micropatterned Substrates Using Micro Photopatterning

PubMed Central

Doyle, Andrew D.

2010-01-01

Micro photopatterning (µPP) has been developed to rapidly test and generate different patterns for extracellular matrix adsorption without being hindered with the process of making physical stamps through nanolithography techniques. It uses two-photon excitation guided through a point-scanning confocal microscope to locally photoablate poly(vinyl) alcohol (PVA) thin films in user-defined computer-controlled patterns. PVA thin films are ideal for surface blocking, being hydrophilic substrates that deter protein adsorption and cell attachment. Because gold substrates are not used during µPP, all live-cell fluorescent imaging techniques including total internal reflection fluorescence microscopy of GFP–linked proteins can be performed with minimal loss of fluorescence signal. Furthermore, because µPP does not require physical stamps for pattern generation, multiple ECMs or other proteins can be localized within microns of each other. This unit details the setup of µPP as well as giving troubleshooting techniques. PMID:20013752

To and From Campus: Changing Student Transportation Patterns.

ERIC Educational Resources Information Center

Fink, Ira Stephen

A thorough study of changing student transportation patterns is justified on the grounds that (1) campuses are major traffic generators; (2) there is increased concern over the need to develop transportation systems that pose less ecological threat to the urban environment; (3) transportation patterns of students, faculty, and staff are changing…

Dentate network activity is necessary for spatial working memory by supporting CA3 sharp-wave ripple generation and prospective firing of CA3 neurons.

PubMed

Sasaki, Takuya; Piatti, Verónica C; Hwaun, Ernie; Ahmadi, Siavash; Lisman, John E; Leutgeb, Stefan; Leutgeb, Jill K

2018-02-01

Complex spatial working memory tasks have been shown to require both hippocampal sharp-wave ripple (SWR) activity and dentate gyrus (DG) neuronal activity. We therefore asked whether DG inputs to CA3 contribute to spatial working memory by promoting SWR generation. Recordings from DG and CA3 while rats performed a dentate-dependent working memory task on an eight-arm radial maze revealed that the activity of dentate neurons and the incidence rate of SWRs both increased during reward consumption. We then found reduced reward-related CA3 SWR generation without direct input from dentate granule neurons. Furthermore, CA3 cells with place fields in not-yet-visited arms preferentially fired during SWRs at reward locations, and these prospective CA3 firing patterns were more pronounced for correct trials and were dentate-dependent. These results indicate that coordination of CA3 neuronal activity patterns by DG is necessary for the generation of neuronal firing patterns that support goal-directed behavior and memory.

Females and males are highly similar in language performance and cortical activation patterns during verb generation.

PubMed

Allendorfer, Jane B; Lindsell, Christopher J; Siegel, Miriam; Banks, Christi L; Vannest, Jennifer; Holland, Scott K; Szaflarski, Jerzy P

2012-10-01

To test the existence of sex differences in cortical activation during verb generation when performance is controlled for. Twenty male and 20 female healthy adults underwent functional magnetic resonance imaging (fMRI) using a covert block-design verb generation task (BD-VGT) and its event-related version (ER-VGT) that allowed for intra-scanner recordings of overt responses. Task-specific activations were determined using the following contrasts: BD-VGT covert generation>finger-tapping; ER-VGT overt generation>repetition; ER-VGT overt>covert generation. Lateral cortical regions activated during each contrast were used for calculating language lateralization index scores. Voxelwise regressions were used to determine sex differences in activation, with and without controlling for performance. Each brain region showing male/female activation differences for ER-VGT overt generation>repetition (isolating noun-verb association) was defined as a region of interest (ROI). For each subject, the signal change in each ROI was extracted, and the association between ER-VGT activation related to noun-verb association and performance was assessed separately for each sex. Males and females performed similarly on language assessments, had similar patterns of language lateralization, and exhibited similar activation patterns for each fMRI task contrast. Regression analysis controlling for overt intra-scanner performance either abolished (BD-VGT) or reduced (ER-VGT) the observed differences in activation between sexes. The main difference between sexes occurred during ER-VGT processing of noun-verb associations, where males showed greater activation than females in the right middle/superior frontal gyrus (MFG/SFG) and the right caudate/anterior cingulate gyrus (aCG) after controlling for performance. Better verb generation performance was associated with increased right caudate/aCG activation in males and with increased right MFG/SFG activation in females. Males and females exhibit similar activation patterns during verb generation fMRI, and controlling for intra-scanner performance reduces or even abolishes sex differences in language-related activation. These results suggest that previous findings of sex differences in neuroimaging studies that did not control for task performance may reflect false positives. Copyright © 2011 Elsevier Srl. All rights reserved.

Evaluation of attenuated PSM photomask blanks with TF11 chrome and FEP-171 resist on a 248 nm DUV laser pattern generator

NASA Astrophysics Data System (ADS)

Xing, Kezhao; Björnborg, Charles; Karlsson, Henrik; Paulsson, Adisa; Rosendahl, Anna; Beiming, Peter; Vedenpää, Jukka; Walford, Jonathan; Newman, Tom

2007-10-01

Tighter requirements on mask resolution, CD and image positioning accuracy at and beyond the 45 nm technology node push the development of improved photomask blanks. One such blank for attenuated phase-shift masks (att-PSM) provides a thinner chrome film, named TF11, with higher chrome etch rate compared to the previous generation Att- PSM blank (NTAR5 chrome film) from the same supplier. Reduced stress in the chrome film also results in less image placement error induced by the material. FEP-171 is the positive chemically amplified resist (PCAR) that is most commonly used in advanced mask manufacturing with both 50 keV variable shaped e-beam (VSB) and DUV laser pattern generators. TF11 allows an FEP-171 resist film down to about 2000 Å thickness with sufficient etch resistance, while the standard resist thickness for NTAR5 is around 3000 Å. This work has experimentally evaluated the use of TF11 chrome and FEP-171 resist together with a 248 nm DUV laser pattern generator, the Sigma7500. First, patterning performance in resist with thicknesses from 2000 Å to 2600 Å, in steps of 100 Å, was tested with respect to swing curve and basic lithographic parameters including resolution, CD linearity, CD iso-dense bias and dose sensitivity. Patterning results on mask showed a swing minimum at around 2200 Å and a swing maximum at around 2500 Å, which correspond to reflectivity measurements for 248 nm wavelength performed by the blank supplier. It was concluded that the overall patterning performance was best close to the swing maximum. Thereafter the patterning performance using TF11 at two resist thicknesses, 2000 Å and 2550 Å, was studied in more detail and compared to performance using NTAR5 with 3200 Å resist. The evaluation showed that the Sigma7500-II offers good compatibility with TF11, especially using the optimized FEP-171 resist thickness of 2550 Å. It also showed that the patterning capability of the Sigma7500-II using TF11 and 2550 Å resist is improved compared to using NTAR5 and 3200 Å resist.

The Impact of Perceived Need and Relational Factors on Mental Health Service Use Among Generations of Asian Americans.

PubMed

Lee, Minsun; Takeuchi, David; Gellis, Zvi; Kendall, Philip; Zhu, Lin; Zhao, Shanyang; Ma, Grace X

2017-08-01

The present study examined generational differences in the patterns and predictors of formal and informal mental health service utilization among a nationally representative sample of 1850 Asian Americans from the National Latino and Asian American Study. We focused on the effects of perceived need and relational factors on service utilization among 1st-, 1.5-, and 2nd-generation Asian Americans. Results of hierarchical logistic regression showed significant intergenerational differences. Specifically, 1.5-generation Asian Americans exhibited distinctive pattern of service use, with perceived need being associated with a higher likelihood of using formal mental health services, but only for those with high level of social support. First- and second-generation Asian Americans, on the other hand, perceived need was independently associated with formal service use, and a significant predictor of informal service use for first generation. Greater family conflict was also associated with greater use of formal and informal services for both first- and second generations. However, family cohesion was associated with only informal service use among first -generation Asian Americans. Implications for mental health service policy were discussed.

Evaluating the impacts of real-time pricing on the usage of wind generation

DOE PAGES

Sioshansi, Ramteen; Short, Walter

2009-02-13

One of the impediments to large-scale use of wind generation within power systems is its nondispatchability and variable and uncertain real-time availability. Operating constraints on conventional generators such as minimum generation points, forbidden zones, and ramping limits as well as system constraints such as power flow limits and ancillary service requirements may force a system operator to curtail wind generation in order to ensure feasibility. Furthermore, the pattern of wind availability and electricity demand may not allow wind generation to be fully utilized in all hours. One solution to these issues, which could reduce these inflexibilities, is the use ofmore » real-time pricing (RTP) tariffs which can both smooth-out the diurnal load pattern in order to reduce the impact of binding unit operating and system constraints on wind utilization, and allow demand to increase in response to the availability of costless wind generation. As a result, we use and analyze a detailed unit commitment model of the Texas power system with different estimates of demand elasticities to demonstrate the potential increases in wind generation from implementing RTP.« less

Species-Specific Diversity of a Fixed Motor Pattern: The Electric Organ Discharge of Gymnotus

PubMed Central

Rodríguez-Cattaneo, Alejo; Pereira, Ana Carolina; Aguilera, Pedro A.; Crampton, William G. R.; Caputi, Angel A.

2008-01-01

Understanding fixed motor pattern diversity across related species provides a window for exploring the evolution of their underlying neural mechanisms. The electric organ discharges of weakly electric fishes offer several advantages as paradigmatic models for investigating how a neural decision is transformed into a spatiotemporal pattern of action. Here, we compared the far fields, the near fields and the electromotive force patterns generated by three species of the pulse generating New World gymnotiform genus Gymnotus. We found a common pattern in electromotive force, with the far field and near field diversity determined by variations in amplitude, duration, and the degree of synchronization of the different components of the electric organ discharges. While the rostral regions of the three species generate similar profiles of electromotive force and local fields, most of the species-specific differences are generated in the main body and tail regions of the fish. This causes that the waveform of the field is highly site dependant in all the studied species. These findings support a hypothesis of the relative separation of the electrolocation and communication carriers. The presence of early head negative waves in the rostral region, a species-dependent early positive wave at the caudal region, and the different relationship between the late negative peak and the main positive peak suggest three points of lability in the evolution of the electrogenic system: a) the variously timed neuronal inputs to different groups of electrocytes; b) the appearance of both rostrally and caudally innervated electrocytes, and c) changes in the responsiveness of the electrocyte membrane. PMID:18461122

Identification of trunk and pelvis movement compensations in patients with transtibial amputation using angular momentum separation.

PubMed

Gaffney, Brecca M; Murray, Amanda M; Christiansen, Cory L; Davidson, Bradley S

2016-03-01

Patients with unilateral dysvascular transtibial amputation (TTA) have a higher risk of developing low back pain than their healthy counterparts, which may be related to movement compensations used in the absence of ankle function. Assessing components of segmental angular momentum provides a unique framework to identify and interpret these movement compensations alongside traditional observational analyses. Angular momentum separation indicates two components of total angular momentum: (1) transfer momentum and (2) rotational momentum. The objective of this investigation was to assess movement compensations in patients with dysvascular TTA, patients with diabetes mellitus (DM), and healthy controls (HC) by examining patterns of generating and arresting trunk and pelvis segmental angular momenta during gait. We hypothesized that all groups would demonstrate similar patterns of generating/arresting total momentum and transfer momentum in the trunk and pelvis in reference to the groups (patients with DM and HC). We also hypothesized that patients with amputation would demonstrate different (larger) patterns of generating/arresting rotational angular momentum in the trunk. Patients with amputation demonstrated differences in trunk and pelvis transfer angular momentum in the sagittal and transverse planes in comparison to the reference groups, which indicates postural compensations adopted during walking. However, patients with amputation demonstrated larger patterns of generating and arresting of trunk and pelvis rotational angular momentum in comparison to the reference groups. These segmental rotational angular momentum patterns correspond with high eccentric muscle demands needed to arrest the angular momentum, and may lead to consequential long-term effects such as low back pain. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of a rhythmic firing pattern in the enteric nervous system that generates rhythmic electrical activity in smooth muscle.

PubMed

Spencer, Nick J; Hibberd, Timothy J; Travis, Lee; Wiklendt, Lukasz; Costa, Marcello; Hu, Hongzhen; Brookes, Simon J; Wattchow, David A; Dinning, Phil G; Keating, Damien J; Sorensen, Julian

2018-05-28

The enteric nervous system (ENS) contains millions of neurons essential for organization of motor behaviour of the intestine. It is well established the large intestine requires ENS activity to drive propulsive motor behaviours. However, the firing pattern of the ENS underlying propagating neurogenic contractions of the large intestine remains unknown. To identify this, we used high resolution neuronal imaging with electrophysiology from neighbouring smooth muscle. Myoelectric activity underlying propagating neurogenic contractions along murine large intestine (referred to as colonic migrating motor complexes, CMMCs) consisted of prolonged bursts of rhythmic depolarizations at a frequency of ∼2 Hz. Temporal coordination of this activity in the smooth muscle over large spatial fields (∼7mm, longitudinally) was dependent on the ENS. During quiescent periods between neurogenic contractions, recordings from large populations of enteric neurons, in mice of either sex, revealed ongoing activity. The onset of neurogenic contractions was characterized by the emergence of temporally synchronized activity across large populations of excitatory and inhibitory neurons. This neuronal firing pattern was rhythmic and temporally synchronized across large numbers of ganglia at ∼2 Hz. ENS activation preceded smooth muscle depolarization, indicating rhythmic depolarizations in smooth muscle were controlled by firing of enteric neurons. The cyclical emergence of temporally coordinated firing of large populations of enteric neurons represents a unique neural motor pattern outside the central nervous system. This is the first direct observation of rhythmic firing in the ENS underlying rhythmic electrical depolarizations in smooth muscle. The pattern of neuronal activity we identified underlies the generation of CMMCs. SIGNIFICANCE STATEMENT How the enteric nervous system (ENS) generates neurogenic contractions of smooth muscle in the gastrointestinal (GI) tract has been a long-standing mystery in vertebrates. It is well known that myogenic pacemaker cells exist in the GI-tract (called Interstitial cells of Cajal, ICC) that generate rhythmic myogenic contractions. However, the mechanisms underlying the generation of rhythmic neurogenic contractions of smooth muscle in the GI-tract remains unknown. We developed a high resolution neuronal imaging method with electrophysiology to address this issue. This technique revealed a novel pattern of rhythmic coordinated neuronal firing in the ENS that has never been identified. Rhythmic neuronal firing in the ENS was found to generate rhythmic neurogenic depolarizations in smooth muscle that underlie contraction of the GI-tract. Copyright © 2018 the authors.

matK-QR classifier: a patterns based approach for plant species identification.

PubMed

More, Ravi Prabhakar; Mane, Rupali Chandrashekhar; Purohit, Hemant J

2016-01-01

DNA barcoding is widely used and most efficient approach that facilitates rapid and accurate identification of plant species based on the short standardized segment of the genome. The nucleotide sequences of maturaseK ( matK ) and ribulose-1, 5-bisphosphate carboxylase ( rbcL ) marker loci are commonly used in plant species identification. Here, we present a new and highly efficient approach for identifying a unique set of discriminating nucleotide patterns to generate a signature (i.e. regular expression) for plant species identification. In order to generate molecular signatures, we used matK and rbcL loci datasets, which encompass 125 plant species in 52 genera reported by the CBOL plant working group. Initially, we performed Multiple Sequence Alignment (MSA) of all species followed by Position Specific Scoring Matrix (PSSM) for both loci to achieve a percentage of discrimination among species. Further, we detected Discriminating Patterns (DP) at genus and species level using PSSM for the matK dataset. Combining DP and consecutive pattern distances, we generated molecular signatures for each species. Finally, we performed a comparative assessment of these signatures with the existing methods including BLASTn, Support Vector Machines (SVM), Jrip-RIPPER, J48 (C4.5 algorithm), and the Naïve Bayes (NB) methods against NCBI-GenBank matK dataset. Due to the higher discrimination success obtained with the matK as compared to the rbcL , we selected matK gene for signature generation. We generated signatures for 60 species based on identified discriminating patterns at genus and species level. Our comparative assessment results suggest that a total of 46 out of 60 species could be correctly identified using generated signatures, followed by BLASTn (34 species), SVM (18 species), C4.5 (7 species), NB (4 species) and RIPPER (3 species) methods As a final outcome of this study, we converted signatures into QR codes and developed a software matK -QR Classifier (http://www.neeri.res.in/matk_classifier/index.htm), which search signatures in the query matK gene sequences and predict corresponding plant species. This novel approach of employing pattern-based signatures opens new avenues for the classification of species. In addition to existing methods, we believe that matK -QR Classifier would be a valuable tool for molecular taxonomists enabling precise identification of plant species.

Generation of helical Ince-Gaussian beams with a liquid-crystal display.

PubMed

Bentley, Joel B; Davis, Jeffrey A; Bandres, Miguel A; Gutiérrez-Vega, Julio C

2006-03-01

We generate helical Ince-Gaussian (HIG) beams by using complex amplitude and phase masks encoded onto a liquid-crystal display (LCD). These beams display an intensity pattern consisting of elliptic rings, whose number and ellipticity can be controlled, and a phase exhibiting a number of in-line vortices, each with a unitary topological charge. We show experimental results that display the properties of these elliptic dark hollow beams. We introduce a novel interference technique for generating the object and reference beams by using a single LCD and show the vortex interference patterns. We expect that these HIG beams will be useful in optical trapping applications.

Surface relief structures for multiple beam LO generation

NASA Technical Reports Server (NTRS)

Veldkamp, W. B.

1980-01-01

Linear and binary holograms for use in heterodyne detection with 10.6 micron imaging arrays are described. The devices match the amplitude and phase of the local oscillator to the received signal and thus maximize the system signal to noise ratio and resolution and minimize heat generation on the focal plane. In both the linear and binary approaches, the holographic surface-relief pattern is coded to generate a set of local oscillator beams when the relief pattern is illuminated by a single planewave. Each beam of this set has the same amplitude shape distribution as, and is collinear with, each single element wavefront illuminating array.

Generation of helical Ince-Gaussian beams with a liquid-crystal display

NASA Astrophysics Data System (ADS)

Bentley, Joel B.; Davis, Jeffrey A.; Bandres, Miguel A.; Gutiérrez-Vega, Julio C.

2006-03-01

We generate helical Ince-Gaussian (HIG) beams by using complex amplitude and phase masks encoded onto a liquid-crystal display (LCD). These beams display an intensity pattern consisting of elliptic rings, whose number and ellipticity can be controlled, and a phase exhibiting a number of in-line vortices, each with a unitary topological charge. We show experimental results that display the properties of these elliptic dark hollow beams. We introduce a novel interference technique for generating the object and reference beams by using a single LCD and show the vortex interference patterns. We expect that these HIG beams will be useful in optical trapping applications.

Ontorat: automatic generation of new ontology terms, annotations, and axioms based on ontology design patterns.

PubMed

Xiang, Zuoshuang; Zheng, Jie; Lin, Yu; He, Yongqun

2015-01-01

It is time-consuming to build an ontology with many terms and axioms. Thus it is desired to automate the process of ontology development. Ontology Design Patterns (ODPs) provide a reusable solution to solve a recurrent modeling problem in the context of ontology engineering. Because ontology terms often follow specific ODPs, the Ontology for Biomedical Investigations (OBI) developers proposed a Quick Term Templates (QTTs) process targeted at generating new ontology classes following the same pattern, using term templates in a spreadsheet format. Inspired by the ODPs and QTTs, the Ontorat web application is developed to automatically generate new ontology terms, annotations of terms, and logical axioms based on a specific ODP(s). The inputs of an Ontorat execution include axiom expression settings, an input data file, ID generation settings, and a target ontology (optional). The axiom expression settings can be saved as a predesigned Ontorat setting format text file for reuse. The input data file is generated based on a template file created by a specific ODP (text or Excel format). Ontorat is an efficient tool for ontology expansion. Different use cases are described. For example, Ontorat was applied to automatically generate over 1,000 Japan RIKEN cell line cell terms with both logical axioms and rich annotation axioms in the Cell Line Ontology (CLO). Approximately 800 licensed animal vaccines were represented and annotated in the Vaccine Ontology (VO) by Ontorat. The OBI team used Ontorat to add assay and device terms required by ENCODE project. Ontorat was also used to add missing annotations to all existing Biobank specific terms in the Biobank Ontology. A collection of ODPs and templates with examples are provided on the Ontorat website and can be reused to facilitate ontology development. With ever increasing ontology development and applications, Ontorat provides a timely platform for generating and annotating a large number of ontology terms by following design patterns. http://ontorat.hegroup.org/.

Emergence of order in visual system development.

PubMed Central

Shatz, C J

1996-01-01

Neural connections in the adult central nervous system are highly precise. In the visual system, retinal ganglion cells send their axons to target neurons in the lateral geniculate nucleus (LGN) in such a way that axons originating from the two eyes terminate in adjacent but nonoverlapping eye-specific layers. During development, however, inputs from the two eyes are intermixed, and the adult pattern emerges gradually as axons from the two eyes sort out to form the layers. Experiments indicate that the sorting-out process, even though it occurs in utero in higher mammals and always before vision, requires retinal ganglion cell signaling; blocking retinal ganglion cell action potentials with tetrodotoxin prevents the formation of the layers. These action potentials are endogenously generated by the ganglion cells, which fire spontaneously and synchronously with each other, generating "waves" of activity that travel across the retina. Calcium imaging of the retina shows that the ganglion cells undergo correlated calcium bursting to generate the waves and that amacrine cells also participate in the correlated activity patterns. Physiological recordings from LGN neurons in vitro indicate that the quasiperiodic activity generated by the retinal ganglion cells is transmitted across the synapse between ganglion cells to drive target LGN neurons. These observations suggest that (i) a neural circuit within the immature retina is responsible for generating specific spatiotemporal patterns of neural activity; (ii) spontaneous activity generated in the retina is propagated across central synapses; and (iii) even before the photoreceptors are present, nerve cell function is essential for correct wiring of the visual system during early development. Since spontaneously generated activity is known to be present elsewhere in the developing CNS, this process of activity-dependent wiring could be used throughout the nervous system to help refine early sets of neural connections into their highly precise adult patterns. Images Fig. 1 Fig. 4 PMID:8570602

Differences in contraceptive use across generations of migration among women of Mexican origin.

PubMed

Wilson, Ellen K

2009-09-01

To explore differences in contraceptive use among women of Mexican origin across generations of migration. Logit models were used to assess contraceptive use among 1,830 women of Mexican origin in Cycles 5 (1995) and 6 (2002) of the National Survey of Family Growth (NSFG). Analyses were stratified by age. Initial models controlled for survey year and underlying differences across generations of migration in age and parity; subsequent models added a range of potential mediating variables. Models account for significant interactions between generation of migration and parity. Among women under age 30 who have not yet had any children, women in their twenties with parity 3 or more, and women 30 or older with parity 1 or 2, those born in the US are much more likely to use contraception than immigrant women. For other levels of parity, there are no significant differences in contraceptive use across generations of migration. Generational differences in marital status, socio-economic status, health insurance coverage, and catholic religiosity did little to mediate the association between generation of migration and contraceptive use. Among women of Mexican origin, patterns of contraceptive use among first-generation immigrants and women of generation 1.5 are similar to those of women in Mexico, with very low rates of contraceptive use among young women who have not yet had a child. Further research is needed to investigate the extent to which this pattern is due to fertility preferences, contraceptive access, or concerns about side effects and infertility. Patterns of contraceptive use appear to change more slowly with acculturation than many other factors, such as education, income, and work force participation.

Apparatus, system, and method for laser-induced breakdown spectroscopy

DOEpatents

Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

2014-11-18

In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

Pleasure systems in the brain

PubMed Central

Berridge, Kent C.; Kringelbach, Morten L.

2015-01-01

Pleasure is mediated by well-developed mesocorticolimbic circuitry, and serves adaptive functions. In affective disorders anhedonia (lack of pleasure) or dysphoria (negative affect) can result from breakdowns of that hedonic system. Human neuroimaging studies indicate that surprisingly similar circuitry is activated by quite diverse pleasures, suggesting a common neural currency shared by all. Wanting for rewards is generated by a large and distributed brain system. Liking, or pleasure itself, is generated by a smaller set of hedonic hotspots within limbic circuitry. Those hotspots also can be embedded in broader anatomical patterns of valence organization, such as in a keyboard pattern of nucleus accumbens generators for desire versus dread. In contrast, some of the best known textbook candidates for pleasure generators, including classic pleasure electrodes and the mesolimbic dopamine system, may not generate pleasure after all. These emerging insights into brain pleasure mechanisms may eventually facilitate better treatments for affective disorders. PMID:25950633

Fractal Branching in Vascular Trees and Networks by VESsel GENeration Analysis (VESGEN)

NASA Technical Reports Server (NTRS)

Parsons-Wingerter, Patricia A.

2016-01-01

Vascular patterning offers an informative multi-scale, fractal readout of regulatory signaling by complex molecular pathways. Understanding such molecular crosstalk is important for physiological, pathological and therapeutic research in Space Biology and Astronaut countermeasures. When mapped out and quantified by NASA's innovative VESsel GENeration Analysis (VESGEN) software, remodeling vascular patterns become useful biomarkers that advance out understanding of the response of biology and human health to challenges such as microgravity and radiation in space environments.

Photochemical preparation of sub-wavelength heterogeneous laser-induced periodic surface structures.

PubMed

Kim, Hee-Cheol; Reinhardt, Hendrik; Hillebrecht, Pierre; Hampp, Norbert A

2012-04-17

Laser-induced periodic surface structures (LIPSS) are a phenomenon caused by interaction of light with solid surfaces. We present a photochemical concept which uses LIPSS-related light intensity patterns for the generation of heterogeneous nanostructures. The process facilitates arbitrary combinations of substrate and LIPSS-pattern materials. An efficient method for the generation of organometallic hybrid-nanowire arrays on porous anodic aluminum oxide is demonstrated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Whole-genome sequencing analysis of phenotypic heterogeneity and anticipation in Li-Fraumeni cancer predisposition syndrome.

PubMed

Ariffin, Hany; Hainaut, Pierre; Puzio-Kuter, Anna; Choong, Soo Sin; Chan, Adelyne Sue Li; Tolkunov, Denis; Rajagopal, Gunaretnam; Kang, Wenfeng; Lim, Leon Li Wen; Krishnan, Shekhar; Chen, Kok-Siong; Achatz, Maria Isabel; Karsa, Mawar; Shamsani, Jannah; Levine, Arnold J; Chan, Chang S

2014-10-28

The Li-Fraumeni syndrome (LFS) and its variant form (LFL) is a familial predisposition to multiple forms of childhood, adolescent, and adult cancers associated with germ-line mutation in the TP53 tumor suppressor gene. Individual disparities in tumor patterns are compounded by acceleration of cancer onset with successive generations. It has been suggested that this apparent anticipation pattern may result from germ-line genomic instability in TP53 mutation carriers, causing increased DNA copy-number variations (CNVs) with successive generations. To address the genetic basis of phenotypic disparities of LFS/LFL, we performed whole-genome sequencing (WGS) of 13 subjects from two generations of an LFS kindred. Neither de novo CNV nor significant difference in total CNV was detected in relation with successive generations or with age at cancer onset. These observations were consistent with an experimental mouse model system showing that trp53 deficiency in the germ line of father or mother did not increase CNV occurrence in the offspring. On the other hand, individual records on 1,771 TP53 mutation carriers from 294 pedigrees were compiled to assess genetic anticipation patterns (International Agency for Research on Cancer TP53 database). No strictly defined anticipation pattern was observed. Rather, in multigeneration families, cancer onset was delayed in older compared with recent generations. These observations support an alternative model for apparent anticipation in which rare variants from noncarrier parents may attenuate constitutive resistance to tumorigenesis in the offspring of TP53 mutation carriers with late cancer onset.

Patterned mask inspection technology with Projection Electron Microscope (PEM) technique for 11 nm half-pitch (hp) generation EUV masks

NASA Astrophysics Data System (ADS)

Hirano, Ryoichi; Iida, Susumu; Amano, Tsuyoshi; Watanabe, Hidehiro; Hatakeyama, Masahiro; Murakami, Takeshi; Yoshikawa, Shoji; Suematsu, Kenichi; Terao, Kenji

2015-07-01

High-sensitivity EUV mask pattern defect detection is one of the major issues in order to realize the device fabrication by using the EUV lithography. We have already designed a novel Projection Electron Microscope (PEM) optics that has been integrated into a new inspection system named EBEYE-V30 ("Model EBEYE" is an EBARA's model code), and which seems to be quite promising for 16 nm hp generation EUVL Patterned mask Inspection (PI). Defect inspection sensitivity was evaluated by capturing an electron image generated at the mask by focusing onto an image sensor. The progress of the novel PEM optics performance is not only about making an image sensor with higher resolution but also about doing a better image processing to enhance the defect signal. In this paper, we describe the experimental results of EUV patterned mask inspection using the above-mentioned system. The performance of the system is measured in terms of defect detectability for 11 nm hp generation EUV mask. To improve the inspection throughput for 11 nm hp generation defect detection, it would require a data processing rate of greater than 1.5 Giga- Pixel-Per-Second (GPPS) that would realize less than eight hours of inspection time including the step-and-scan motion associated with the process. The aims of the development program are to attain a higher throughput, and enhance the defect detection sensitivity by using an adequate pixel size with sophisticated image processing resulting in a higher processing rate.

Reflection Patterns Generated by Condensed-Phase Oblique Detonation Interaction with a Rigid Wall

NASA Astrophysics Data System (ADS)

Short, Mark; Chiquete, Carlos; Bdzil, John; Meyer, Chad

2017-11-01

We examine numerically the wave reflection patterns generated by a detonation in a condensed phase explosive inclined obliquely but traveling parallel to a rigid wall as a function of incident angle. The problem is motivated by the characterization of detonation-material confiner interactions. We compare the reflection patterns for two detonation models, one where the reaction zone is spatially distributed, and the other where the reaction is instantaneous (a Chapman-Jouguet detonation). For the Chapman-Jouguet model, we compare the results of the computations with an asymptotic study recently conducted by Bdzil and Short for small detonation incident angles. We show that the ability of a spatially distributed reaction energy release to turn flow streamlines has a significant impact on the nature of the observed reflection patterns. The computational approach uses a shock-fit methodology.

Combinatorial Histone Acetylation Patterns Are Generated by Motif-Specific Reactions.

PubMed

Blasi, Thomas; Feller, Christian; Feigelman, Justin; Hasenauer, Jan; Imhof, Axel; Theis, Fabian J; Becker, Peter B; Marr, Carsten

2016-01-27

Post-translational modifications (PTMs) are pivotal to cellular information processing, but how combinatorial PTM patterns ("motifs") are set remains elusive. We develop a computational framework, which we provide as open source code, to investigate the design principles generating the combinatorial acetylation patterns on histone H4 in Drosophila melanogaster. We find that models assuming purely unspecific or lysine site-specific acetylation rates were insufficient to explain the experimentally determined motif abundances. Rather, these abundances were best described by an ensemble of models with acetylation rates that were specific to motifs. The model ensemble converged upon four acetylation pathways; we validated three of these using independent data from a systematic enzyme depletion study. Our findings suggest that histone acetylation patterns originate through specific pathways involving motif-specific acetylation activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Programmable assembly of pressure sensors using pattern-forming bacteria

PubMed Central

Cao, Yangxiaolu; Feng, Yaying; Ryser, Marc D.; Zhu, Kui; Herschlag, Gregory; Cao, Changyong; Marusak, Katherine; Zauscher, Stefan; You, Lingchong

2017-01-01

Biological systems can generate microstructured materials that combine organic and inorganic components and possess diverse physical and chemical properties. However, these natural processes in materials fabrication are not readily programmable. Here, we use a synthetic-biology approach to mimic such natural processes to assemble patterned materials.. We demonstrate programmable fabrication of three-dimensional (3D) materials by printing engineered self-patterning bacteria on permeable membranes that serve as a structural scaffold. Application of gold nanoparticles to the colonies creates hybrid organic-inorganic dome structures. The dynamics of the dome structures' response to pressure is determined by their geometry (colony size, dome height and pattern), which is easily modified by varying the properties of the membrane (e.g., pore size and hydrophobicity). We generate resettable pressure sensors that process signals in response to varying pressure intensity and duration. PMID:28991268

Pattern Formations for Optical Switching Using Cold Atoms as a Nonlinear Medium

NASA Astrophysics Data System (ADS)

Schmittberger, Bonnie; Greenberg, Joel; Gauthier, Daniel

2011-05-01

The study of spatio-temporal pattern formation in nonlinear optical systems has both led to an increased understanding of nonlinear dynamics as well as given rise to sensitive new methods for all-optical switching. Whereas the majority of past experiments utilized warm atomic vapors as nonlinear media, we report the first observation of an optical instability leading to pattern formation in a cloud of cold Rubidium atoms. When we shine a pair of counterpropagating pump laser beams along the pencil-shaped cloud's long axis, new beams of light are generated along cones centered on the trap. This generated light produces petal-like patterns in the plane orthogonal to the pump beams that can be used for optical switching. We gratefully acknowledge the financial support of the NSF through Grant #PHY-0855399 and the DARPA Slow Light Program.

Pattern formation in individual-based systems with time-varying parameters

NASA Astrophysics Data System (ADS)

Ashcroft, Peter; Galla, Tobias

2013-12-01

We study the patterns generated in finite-time sweeps across symmetry-breaking bifurcations in individual-based models. Similar to the well-known Kibble-Zurek scenario of defect formation, large-scale patterns are generated when model parameters are varied slowly, whereas fast sweeps produce a large number of small domains. The symmetry breaking is triggered by intrinsic noise, originating from the discrete dynamics at the microlevel. Based on a linear-noise approximation, we calculate the characteristic length scale of these patterns. We demonstrate the applicability of this approach in a simple model of opinion dynamics, a model in evolutionary game theory with a time-dependent fitness structure, and a model of cell differentiation. Our theoretical estimates are confirmed in simulations. In further numerical work, we observe a similar phenomenon when the symmetry-breaking bifurcation is triggered by population growth.

Geographic patterns of industry in the United States. An aid to the study of occupational disease.

PubMed

Stone, B J; Blot, W J; Fraumeni, J F

1978-07-01

The geographic location of 18 major manufacturing industries within the United States is illustrated by a series of computer-generated county maps. The metal and machinery industries, the two largest employers, an the transportation and rubber industries are concentrated in the northeastern quadrant of the United States, while most counties with textile, apparel, tobacco, and furniture manufacturing are in the South. Other industries had different patterns. The counties where industry was concentrated tended to be more urban and to have higher levels of income and education. The maps and associated demographic data on industrial counties may prove a useful adjunct to county maps illustrating mortality patterns for cancer and other diseases. Despite obvious limitations, the visual patterns and correlation analyses may help to generate and formulate hypothese concerning occupationally induced diease.

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

Rodríguez-González, R.; Martínez-Orozco, J. C.; Madrigal-Melchor, J.

In this work we use the standard T-matrix method to study the tunneling of Dirac electrons through graphene multilayers. A graphene sheet is deposited on top of slabs of Silicon-Oxide (SiO{sub 2}) and Silicon-Carbide (SiC) substrates, in which we applied the Cantor’s series. We calculate the transmittance as a function of energy for different incident angles and different generations of the Cantor’s series. Comparing the transmittance, we found three types of self-similarity: (a) local - into generations, (b) between incident angles and (c) between generations. We also compute the angular distribution of the transmittance for fixed energies finding a self-similarmore » pattern between generations. To our knowledge is the first time that four different self-similar patterns are presented in Cantor-based multilayers.« less

Isotropic image in structured illumination microscopy patterned with a spatial light modulator.

PubMed

Chang, Bo-Jui; Chou, Li-Jun; Chang, Yun-Ching; Chiang, Su-Yu

2009-08-17

We developed a structured illumination microscopy (SIM) system that uses a spatial light modulator (SLM) to generate interference illumination patterns at four orientations - 0 degrees, 45 degrees, 90 degrees, and 135 degrees, to reconstruct a high-resolution image. The use of a SLM for pattern alterations is rapid and precise, without mechanical calibration; moreover, our design of SLM patterns allows generating the four illumination patterns of high contrast and nearly equivalent periods to achieve a near isotropic enhancement in lateral resolution. We compare the conventional image of 100-nm beads with those reconstructed from two (0 degrees +90 degrees or 45 degrees +135 degrees) and four (0 degrees +45 degrees +90 degrees +135 degrees) pattern orientations to show the differences in resolution and image, with the support of simulations. The reconstructed images of 200-nm beads at various depths and fine structures of actin filaments near the edge of a HeLa cell are presented to demonstrate the intensity distributions in the axial direction and the prospective application to biological systems. (c) 2009 Optical Society of America

Cell adhesion and mechanics as drivers of tissue organization and differentiation: local cues for large scale organization.

PubMed

Wickström, Sara A; Niessen, Carien M

2018-06-01

Biological patterns emerge through specialization of genetically identical cells to take up distinct fates according to their position within the organism. How initial symmetry is broken to give rise to these patterns remains an intriguing open question. Several theories of patterning have been proposed, most prominently Turing's reaction-diffusion model of a slowly diffusing activator and a fast diffusing inhibitor generating periodic patterns. Although these reaction-diffusion systems can generate diverse patterns, it is becoming increasingly evident that cell shape and tension anisotropies, mediated via cell-cell and/or cell-matrix contacts, also facilitate symmetry breaking and subsequent self-organized tissue patterning. This review will highlight recent studies that implicate local changes in adhesion and/or tension as key drivers of cell rearrangements. We will also discuss recent studies on the role of cadherin and integrin adhesive receptors in mediating and responding to local tissue tension asymmetries to coordinate cell fate, position and behavior essential for tissue self-organization and maintenance. Copyright © 2018 Elsevier Ltd. All rights reserved.

NeuroPG: open source software for optical pattern generation and data acquisition

PubMed Central

Avants, Benjamin W.; Murphy, Daniel B.; Dapello, Joel A.; Robinson, Jacob T.

2015-01-01

Patterned illumination using a digital micromirror device (DMD) is a powerful tool for optogenetics. Compared to a scanning laser, DMDs are inexpensive and can easily create complex illumination patterns. Combining these complex spatiotemporal illumination patterns with optogenetics allows DMD-equipped microscopes to probe neural circuits by selectively manipulating the activity of many individual cells or many subcellular regions at the same time. To use DMDs to study neural activity, scientists must develop specialized software to coordinate optical stimulation patterns with the acquisition of electrophysiological and fluorescence data. To meet this growing need we have developed an open source optical pattern generation software for neuroscience—NeuroPG—that combines, DMD control, sample visualization, and data acquisition in one application. Built on a MATLAB platform, NeuroPG can also process, analyze, and visualize data. The software is designed specifically for the Mightex Polygon400; however, as an open source package, NeuroPG can be modified to incorporate any data acquisition, imaging, or illumination equipment that is compatible with MATLAB’s Data Acquisition and Image Acquisition toolboxes. PMID:25784873

Laser shock wave assisted patterning on NiTi shape memory alloy surfaces

NASA Astrophysics Data System (ADS)

Seyitliyev, Dovletgeldi; Li, Peizhen; Kholikov, Khomidkhodza; Grant, Byron; Karaca, Haluk E.; Er, Ali O.

2017-02-01

An advanced direct imprinting method with low cost, quick, and less environmental impact to create thermally controllable surface pattern using the laser pulses is reported. Patterned micro indents were generated on Ni50Ti50 shape memory alloys (SMA) using an Nd:YAG laser operating at 1064 nm combined with suitable transparent overlay, a sacrificial layer of graphite, and copper grid. Laser pulses at different energy densities which generates pressure pulses up to 10 GPa on the surface was focused through the confinement medium, ablating the copper grid to create plasma and transferring the grid pattern onto the NiTi surface. Scanning electron microscope (SEM) and optical microscope images of square pattern with different sizes were studied. One dimensional profile analysis shows that the depth of the patterned sample initially increase linearly with the laser energy until 125 mJ/pulse where the plasma further absorbs and reflects the laser beam. In addition, light the microscope image show that the surface of NiTi alloy was damaged due to the high power laser energy which removes the graphite layer.

Injury Patterns Sustained in Fatal Motor Vehicle Collisions with Driver's Third-Generation Airbag Deployment.

PubMed

Kuk, Mariya; Shkrum, Michael J

2018-05-01

The Office of the Chief Coroner for Ontario database for 2011-2012 was used to compare fatal injury patterns in drivers whose third-generation airbags deployed compared to first- and second-generation airbag deployments and airbag nondeployments with and without seatbelt use. There were 110 frontal and offset frontal crashes analyzed. The small sample size meant that the odds of craniocerebral, cervical spinal, thoracic, and abdominal injuries were not statistically different for airbag generation, deployment status, and seatbelt use; however, the risk of fatal thoracic injuries in third- and second-generation cases was increased. Seatbelt usage in third- and second-generation deployment cases reduced the risk of all injuries except abdominal trauma. High severity impacts and occupant compartment intrusion were frequently observed. The analyses in this retrospective study were challenged by data that were not collated in a standardized way and were limited in details about scene, vehicle, and driver variables. © 2017 American Academy of Forensic Sciences.

Generational Patterns in Mexican Americans' Academic Performance in an Unwelcoming Political Context

PubMed Central

Moosmann, Danyel A. V.; Roosa, Mark W.; Knight, George P.

2014-01-01

Research has shown that immigrant students often do better academically than their U.S.-born peers from the same ethnic group but it is unclear whether this pattern holds for Mexican Americans. We examined the academic performance of four generations of Mexican American students from fifth to 10th grade looking for generation differences and explanations for them. Using data from 749 families, we tested a model with fifth grade variables that differed by generation as potential mediators linking student generation to 10th grade academic performance. Results showed that immigrants were academically behind at fifth grade but caught up by seventh. Only economic hardship mediated the long term relationship between student generation and 10th grade academic performance; maternal educational expectations and child language hassles, English usage, discrimination, and mainstream values helped explained the early academic deficit of immigrant children. The results identified potential targets for interventions to improve Mexican American students' academic performance. PMID:24578588

Surface Structuring with Polarization-Singular Femtosecond Laser Beams Generated by a q-plate

PubMed Central

Nivas, Jijil JJ; Cardano, Filippo; Song, Zhenming; Rubano, Andrea; Fittipaldi, Rosalba; Vecchione, Antonio; Paparo, Domenico; Marrucci, Lorenzo; Bruzzese, Riccardo; Amoruso, Salvatore

2017-01-01

In the last few years femtosecond optical vortex beams with different spatial distributions of the state of polarization (e.g. azimuthal, radial, spiral, etc.) have been used to generate complex, regular surface patterns on different materials. Here we present an experimental investigation on direct femtosecond laser surface structuring based on a larger class of vector beams generated by means of a q-plate with topological charge q = +1/2. In fact, voltage tuning of q-plate optical retardation allows generating a family of ultrashort laser beams with a continuous spatial evolution of polarization and fluence distribution in the focal plane. These beams can be thought of as a controlled coherent superposition of a Gaussian beam with uniform polarization and a vortex beam with a radial or azimuthal state of polarization. The use of this family of ultrashort laser beams in surface structuring leads to a further extension of the achievable surface patterns. The comparison of theoretical predictions of the vector beam characteristics at the focal plane and the generated surface patterns is used to rationalize the dependence of the surface structures on the local state of the laser beam, thus offering an effective way to either design unconventional surface structures or diagnose complex ultrashort laser beams. PMID:28169342

Surface Structuring with Polarization-Singular Femtosecond Laser Beams Generated by a q-plate.

PubMed

Nivas, Jijil Jj; Cardano, Filippo; Song, Zhenming; Rubano, Andrea; Fittipaldi, Rosalba; Vecchione, Antonio; Paparo, Domenico; Marrucci, Lorenzo; Bruzzese, Riccardo; Amoruso, Salvatore

2017-02-07

In the last few years femtosecond optical vortex beams with different spatial distributions of the state of polarization (e.g. azimuthal, radial, spiral, etc.) have been used to generate complex, regular surface patterns on different materials. Here we present an experimental investigation on direct femtosecond laser surface structuring based on a larger class of vector beams generated by means of a q-plate with topological charge q = +1/2. In fact, voltage tuning of q-plate optical retardation allows generating a family of ultrashort laser beams with a continuous spatial evolution of polarization and fluence distribution in the focal plane. These beams can be thought of as a controlled coherent superposition of a Gaussian beam with uniform polarization and a vortex beam with a radial or azimuthal state of polarization. The use of this family of ultrashort laser beams in surface structuring leads to a further extension of the achievable surface patterns. The comparison of theoretical predictions of the vector beam characteristics at the focal plane and the generated surface patterns is used to rationalize the dependence of the surface structures on the local state of the laser beam, thus offering an effective way to either design unconventional surface structures or diagnose complex ultrashort laser beams.

Surface Structuring with Polarization-Singular Femtosecond Laser Beams Generated by a q-plate

NASA Astrophysics Data System (ADS)

Nivas, Jijil Jj; Cardano, Filippo; Song, Zhenming; Rubano, Andrea; Fittipaldi, Rosalba; Vecchione, Antonio; Paparo, Domenico; Marrucci, Lorenzo; Bruzzese, Riccardo; Amoruso, Salvatore

2017-02-01

In the last few years femtosecond optical vortex beams with different spatial distributions of the state of polarization (e.g. azimuthal, radial, spiral, etc.) have been used to generate complex, regular surface patterns on different materials. Here we present an experimental investigation on direct femtosecond laser surface structuring based on a larger class of vector beams generated by means of a q-plate with topological charge q = +1/2. In fact, voltage tuning of q-plate optical retardation allows generating a family of ultrashort laser beams with a continuous spatial evolution of polarization and fluence distribution in the focal plane. These beams can be thought of as a controlled coherent superposition of a Gaussian beam with uniform polarization and a vortex beam with a radial or azimuthal state of polarization. The use of this family of ultrashort laser beams in surface structuring leads to a further extension of the achievable surface patterns. The comparison of theoretical predictions of the vector beam characteristics at the focal plane and the generated surface patterns is used to rationalize the dependence of the surface structures on the local state of the laser beam, thus offering an effective way to either design unconventional surface structures or diagnose complex ultrashort laser beams.

Unravelling a biogeographical knot: origin of the 'leapfrog' distribution pattern of Australo-Papuan sooty owls (Strigiformes) and logrunners (Passeriformes).

PubMed

Norman, J A; Christidis, L; Joseph, L; Slikas, B; Alpers, D

2002-10-22

Molecular analysis of two Australo-Papuan rainforest birds exhibiting correlated 'leapfrog' patterns were used to elucidate the evolutionary origin of this unusual pattern of geographical differentiation. In both sooty owls (Tyto) and logrunners (Orthonyx), phenotypically similar populations occupy widely disjunct areas (central-eastern Australia and upland New Guinea) with a third, highly distinctive population, occurring between them in northeastern Queensland. Two mechanisms have been proposed to explain the origin of leapfrog patterns in avian distributions: recent shared ancestry of terminal populations and unequal rates or phenotypic change among populations. As the former should generate correlated patterns of phenotypic and genetic differentiation, we tested for a sister relationship between populations from New Guinea and central-eastern Australia using nuclear and mitochondrial DNA sequences. The resulting phylogenies not only refute recent ancestry as an explanation for the leapfrog pattern, but provide evidence of vastly different spatio-temporal histories for sooty owls and logrunners within the Australo-Papuan rainforests. This incongruence indicates that the evolutionary processes responsible for generating leapfrog patterns in these co-distributed taxa are complex, possibly involving a combination of selection and drift in sooty owls and convergence or retention of ancestral characteristics in logrunners.

Optimization of Training Sets For Neural-Net Processing of Characteristic Patterns From Vibrating Solids

NASA Technical Reports Server (NTRS)

Decker, Arthur J. (Inventor)

2006-01-01

An artificial neural network is disclosed that processes holography generated characteristic pattern of vibrating structures along with finite-element models. The present invention provides for a folding operation for conditioning training sets for optimally training forward-neural networks to process characteristic fringe pattern. The folding pattern increases the sensitivity of the feed-forward network for detecting changes in the characteristic pattern The folding routine manipulates input pixels so as to be scaled according to the location in an intensity range rather than the position in the characteristic pattern.

Laboratory Instrumentation Design Research for Scalable Next Generation Epitaxy: Non-Equilibrium Wide Application Epitaxial Patterning by Intelligent Control (NEW-EPIC). Volume 1. 3D Composition/Doping Control via Micromiror Patterned Deep UV Photodesorption: Revolutionary in situ Characterization/Control

DTIC Science & Technology

2009-02-19

magnesium dopant concentration. A digital micromirror device is introduced to pattern incident UV radiation during InGaN growth, demonstrating that the...magnesium dopant concentration. A digital micromirror device is introduced to pattern incident UV radiation during InGaN growth, demonstrating that the...successful compositional patterning of InGaN using in situ digital micromirror device (DMD) patterning of ultraviolet (UV

Host-induced bacterial cell wall decomposition mediates pattern-triggered immunity in Arabidopsis

PubMed Central

Liu, Xiaokun; Grabherr, Heini M; Willmann, Roland; Kolb, Dagmar; Brunner, Frédéric; Bertsche, Ute; Kühner, Daniel; Franz-Wachtel, Mirita; Amin, Bushra; Felix, Georg; Ongena, Marc; Nürnberger, Thorsten; Gust, Andrea A

2014-01-01

Peptidoglycans (PGNs) are immunogenic bacterial surface patterns that trigger immune activation in metazoans and plants. It is generally unknown how complex bacterial structures such as PGNs are perceived by plant pattern recognition receptors (PRRs) and whether host hydrolytic activities facilitate decomposition of bacterial matrices and generation of soluble PRR ligands. Here we show that Arabidopsis thaliana, upon bacterial infection or exposure to microbial patterns, produces a metazoan lysozyme-like hydrolase (lysozyme 1, LYS1). LYS1 activity releases soluble PGN fragments from insoluble bacterial cell walls and cleavage products are able to trigger responses typically associated with plant immunity. Importantly, LYS1 mutant genotypes exhibit super-susceptibility to bacterial infections similar to that observed on PGN receptor mutants. We propose that plants employ hydrolytic activities for the decomposition of complex bacterial structures, and that soluble pattern generation might aid PRR-mediated immune activation in cell layers adjacent to infection sites. DOI: http://dx.doi.org/10.7554/eLife.01990.001 PMID:24957336

Micropattern differentiation of mouse pluripotent stem cells recapitulates embryo regionalized cell fate patterning

PubMed Central

Morgani, Sophie M; Metzger, Jakob J; Nichols, Jennifer

2018-01-01

During gastrulation epiblast cells exit pluripotency as they specify and spatially arrange the three germ layers of the embryo. Similarly, human pluripotent stem cells (PSCs) undergo spatially organized fate specification on micropatterned surfaces. Since in vivo validation is not possible for the human, we developed a mouse PSC micropattern system and, with direct comparisons to mouse embryos, reveal the robust specification of distinct regional identities. BMP, WNT, ACTIVIN and FGF directed mouse epiblast-like cells to undergo an epithelial-to-mesenchymal transition and radially pattern posterior mesoderm fates. Conversely, WNT, ACTIVIN and FGF patterned anterior identities, including definitive endoderm. By contrast, epiblast stem cells, a developmentally advanced state, only specified anterior identities, but without patterning. The mouse micropattern system offers a robust scalable method to generate regionalized cell types present in vivo, resolve how signals promote distinct identities and generate patterns, and compare mechanisms operating in vivo and in vitro and across species. PMID:29412136

EUV patterning improvement toward high-volume manufacturing

NASA Astrophysics Data System (ADS)

Kuwahara, Yuhei; Matsunaga, Koichi; Kawakami, Shinichiro; Nafus, Kathleen; Foubert, Philippe; Goethals, Anne-Marie

2015-03-01

Extreme ultraviolet lithography (EUVL) technology is a promising candidate for a semiconductor process for 18nm half pitch and beyond. So far, the studies of EUV for manufacturability have been focused on particular aspects. It still requires fine resolution, uniform and smooth patterns, and low defectivity, not only after lithography but also after the etch process. Tokyo Electron Limited and imec are continuously collaborating to improve manufacturing quality of the process of record (POR) on a CLEAN TRACKTM LITHIUS ProTMZ-EUV. This next generation coating/developing system has been upgraded with defectivity reduction enhancements which are applied along with TELTM best known methods. We have evaluated process defectivity post lithography and post etch. Apart from defectivity, FIRMTM rinse material and application compatibility with sub 18nm patterning is improved to prevent line pattern collapse and increase process window on next generation resist materials. This paper reports on the progress of defectivity and patterning performance optimization towards the NXE:3300 POR.

Fundamental physics issues of multilevel logic in developing a parallel processor.

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Anirban; Miki, Kazushi

2007-06-01

In the last century, On and Off physical switches, were equated with two decisions 0 and 1 to express every information in terms of binary digits and physically realize it in terms of switches connected in a circuit. Apart from memory-density increase significantly, more possible choices in particular space enables pattern-logic a reality, and manipulation of pattern would allow controlling logic, generating a new kind of processor. Neumann's computer is based on sequential logic, processing bits one by one. But as pattern-logic is generated on a surface, viewing whole pattern at a time is a truly parallel processing. Following Neumann's and Shannons fundamental thermodynamical approaches we have built compatible model based on series of single molecule based multibit logic systems of 4-12 bits in an UHV-STM. On their monolayer multilevel communication and pattern formation is experimentally verified. Furthermore, the developed intelligent monolayer is trained by Artificial Neural Network. Therefore fundamental weak interactions for the building of truly parallel processor are explored here physically and theoretically.

Three ancient hormonal cues co-ordinate shoot branching in a moss

PubMed Central

Coudert, Yoan; Palubicki, Wojtek; Ljung, Karin; Novak, Ondrej; Leyser, Ottoline; Harrison, C Jill

2015-01-01

Shoot branching is a primary contributor to plant architecture, evolving independently in flowering plant sporophytes and moss gametophytes. Mechanistic understanding of branching is largely limited to flowering plants such as Arabidopsis, which have a recent evolutionary origin. We show that in gametophytic shoots of Physcomitrella, lateral branches arise by re-specification of epidermal cells into branch initials. A simple model co-ordinating the activity of leafy shoot tips can account for branching patterns, and three known and ancient hormonal regulators of sporophytic branching interact to generate the branching pattern- auxin, cytokinin and strigolactone. The mode of auxin transport required in branch patterning is a key divergence point from known sporophytic pathways. Although PIN-mediated basipetal auxin transport regulates branching patterns in flowering plants, this is not so in Physcomitrella, where bi-directional transport is required to generate realistic branching patterns. Experiments with callose synthesis inhibitors suggest plasmodesmal connectivity as a potential mechanism for transport. DOI: http://dx.doi.org/10.7554/eLife.06808.001 PMID:25806686

System-dependent regulations of colour-pattern development: a mutagenesis study of the pale grass blue butterfly

PubMed Central

Iwata, Masaki; Hiyama, Atsuki; Otaki, Joji M.

2013-01-01

Developmental studies on wing colour patterns have been performed in nymphalid butterflies, but efficient genetic manipulations, including mutagenesis, have not been well established. Here, we have performed mutagenesis experiments in a lycaenid butterfly, the pale grass blue Zizeeria maha, to produce colour-pattern mutants. We fed the P-generation larvae an artificial diet containing the mutagen ethyl methane sulfonate (EMS), and the F1- and F2-generation adults showed various aberrant colour patterns: dorsoventral transformation, anterioposterior background colouration gap, weak contrast, disarrangement of spots, reduction of the size of spots, loss of spots, fusion of spots, and ectopic spots. Among them, the disarrangement, reduction, and loss of spots were likely produced by the coordinated changes of many spots of a single wing around the discal spot in a system-dependent manner, demonstrating the existence of the central symmetry system. The present study revealed multiple genetic regulations for system-dependent and wing-wide colour-pattern determination in lycaenid butterflies. PMID:23917124

PatterNet: a system to learn compact physical design pattern representations for pattern-based analytics

NASA Astrophysics Data System (ADS)

Lutich, Andrey

2017-07-01

This research considers the problem of generating compact vector representations of physical design patterns for analytics purposes in semiconductor patterning domain. PatterNet uses a deep artificial neural network to learn mapping of physical design patterns to a compact Euclidean hyperspace. Distances among mapped patterns in this space correspond to dissimilarities among patterns defined at the time of the network training. Once the mapping network has been trained, PatterNet embeddings can be used as feature vectors with standard machine learning algorithms, and pattern search, comparison, and clustering become trivial problems. PatterNet is inspired by the concepts developed within the framework of generative adversarial networks as well as the FaceNet. Our method facilitates a deep neural network (DNN) to learn directly the compact representation by supplying it with pairs of design patterns and dissimilarity among these patterns defined by a user. In the simplest case, the dissimilarity is represented by an area of the XOR of two patterns. Important to realize that our PatterNet approach is very different to the methods developed for deep learning on image data. In contrast to "conventional" pictures, the patterns in the CAD world are the lists of polygon vertex coordinates. The method solely relies on the promise of deep learning to discover internal structure of the incoming data and learn its hierarchical representations. Artificial intelligence arising from the combination of PatterNet and clustering analysis very precisely follows intuition of patterning/optical proximity correction experts paving the way toward human-like and human-friendly engineering tools.

Waves and patterning in developmental biology: vertebrate segmentation and feather bud formation as case studies

PubMed Central

Baker, Ruth E.; Schnell, Santiago; Maini, Philip K.

2014-01-01

In this article we will discuss the integration of developmental patterning mechanisms with waves of competency that control the ability of a homogeneous field of cells to react to pattern forming cues and generate spatially heterogeneous patterns. We base our discussion around two well known patterning events that take place in the early embryo: somitogenesis and feather bud formation. We outline mathematical models to describe each patterning mechanism, present the results of numerical simulations and discuss the validity of each model in relation to our example patterning processes. PMID:19557684

Patterns of glaucomatous visual field loss in sita fields automatically identified using independent component analysis.

PubMed

Goldbaum, Michael H; Jang, Gil-Jin; Bowd, Chris; Hao, Jiucang; Zangwill, Linda M; Liebmann, Jeffrey; Girkin, Christopher; Jung, Tzyy-Ping; Weinreb, Robert N; Sample, Pamela A

2009-12-01

To determine if the patterns uncovered with variational Bayesian-independent component analysis-mixture model (VIM) applied to a large set of normal and glaucomatous fields obtained with the Swedish Interactive Thresholding Algorithm (SITA) are distinct, recognizable, and useful for modeling the severity of the field loss. SITA fields were obtained with the Humphrey Visual Field Analyzer (Carl Zeiss Meditec, Inc, Dublin, California) on 1,146 normal eyes and 939 glaucoma eyes from subjects followed by the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. VIM modifies independent component analysis (ICA) to develop separate sets of ICA axes in the cluster of normal fields and the 2 clusters of abnormal fields. Of 360 models, the model with the best separation of normal and glaucomatous fields was chosen for creating the maximally independent axes. Grayscale displays of fields generated by VIM on each axis were compared. SITA fields most closely associated with each axis and displayed in grayscale were evaluated for consistency of pattern at all severities. The best VIM model had 3 clusters. Cluster 1 (1,193) was mostly normal (1,089, 95% specificity) and had 2 axes. Cluster 2 (596) contained mildly abnormal fields (513) and 2 axes; cluster 3 (323) held mostly moderately to severely abnormal fields (322) and 5 axes. Sensitivity for clusters 2 and 3 combined was 88.9%. The VIM-generated field patterns differed from each other and resembled glaucomatous defects (eg, nasal step, arcuate, temporal wedge). SITA fields assigned to an axis resembled each other and the VIM-generated patterns for that axis. Pattern severity increased in the positive direction of each axis by expansion or deepening of the axis pattern. VIM worked well on SITA fields, separating them into distinctly different yet recognizable patterns of glaucomatous field defects. The axis and pattern properties make VIM a good candidate as a preliminary process for detecting progression.

BrEPS 2.0: Optimization of sequence pattern prediction for enzyme annotation.

PubMed

Dudek, Christian-Alexander; Dannheim, Henning; Schomburg, Dietmar

2017-01-01

The prediction of gene functions is crucial for a large number of different life science areas. Faster high throughput sequencing techniques generate more and larger datasets. The manual annotation by classical wet-lab experiments is not suitable for these large amounts of data. We showed earlier that the automatic sequence pattern-based BrEPS protocol, based on manually curated sequences, can be used for the prediction of enzymatic functions of genes. The growing sequence databases provide the opportunity for more reliable patterns, but are also a challenge for the implementation of automatic protocols. We reimplemented and optimized the BrEPS pattern generation to be applicable for larger datasets in an acceptable timescale. Primary improvement of the new BrEPS protocol is the enhanced data selection step. Manually curated annotations from Swiss-Prot are used as reliable source for function prediction of enzymes observed on protein level. The pool of sequences is extended by highly similar sequences from TrEMBL and SwissProt. This allows us to restrict the selection of Swiss-Prot entries, without losing the diversity of sequences needed to generate significant patterns. Additionally, a supporting pattern type was introduced by extending the patterns at semi-conserved positions with highly similar amino acids. Extended patterns have an increased complexity, increasing the chance to match more sequences, without losing the essential structural information of the pattern. To enhance the usability of the database, we introduced enzyme function prediction based on consensus EC numbers and IUBMB enzyme nomenclature. BrEPS is part of the Braunschweig Enzyme Database (BRENDA) and is available on a completely redesigned website and as download. The database can be downloaded and used with the BrEPScmd command line tool for large scale sequence analysis. The BrEPS website and downloads for the database creation tool, command line tool and database are freely accessible at http://breps.tu-bs.de.

BrEPS 2.0: Optimization of sequence pattern prediction for enzyme annotation

PubMed Central

Schomburg, Dietmar

2017-01-01

The prediction of gene functions is crucial for a large number of different life science areas. Faster high throughput sequencing techniques generate more and larger datasets. The manual annotation by classical wet-lab experiments is not suitable for these large amounts of data. We showed earlier that the automatic sequence pattern-based BrEPS protocol, based on manually curated sequences, can be used for the prediction of enzymatic functions of genes. The growing sequence databases provide the opportunity for more reliable patterns, but are also a challenge for the implementation of automatic protocols. We reimplemented and optimized the BrEPS pattern generation to be applicable for larger datasets in an acceptable timescale. Primary improvement of the new BrEPS protocol is the enhanced data selection step. Manually curated annotations from Swiss-Prot are used as reliable source for function prediction of enzymes observed on protein level. The pool of sequences is extended by highly similar sequences from TrEMBL and SwissProt. This allows us to restrict the selection of Swiss-Prot entries, without losing the diversity of sequences needed to generate significant patterns. Additionally, a supporting pattern type was introduced by extending the patterns at semi-conserved positions with highly similar amino acids. Extended patterns have an increased complexity, increasing the chance to match more sequences, without losing the essential structural information of the pattern. To enhance the usability of the database, we introduced enzyme function prediction based on consensus EC numbers and IUBMB enzyme nomenclature. BrEPS is part of the Braunschweig Enzyme Database (BRENDA) and is available on a completely redesigned website and as download. The database can be downloaded and used with the BrEPScmd command line tool for large scale sequence analysis. The BrEPS website and downloads for the database creation tool, command line tool and database are freely accessible at http://breps.tu-bs.de. PMID:28750104

Long-Term Interactions of Streamflow Generation and River Basin Morphology

NASA Astrophysics Data System (ADS)

Huang, X.; Niemann, J.

2005-12-01

It is well known that the spatial patterns and dynamics of streamflow generation processes depend on river basin topography, but the impact of streamflow generation processes on the long-term evolution of river basins has not drawn as much attention. Fluvial erosion processes are driven by streamflow, which can be produced by Horton runoff, Dunne runoff, and groundwater discharge. In this analysis, we hypothesize that the dominant streamflow generation process in a basin affects the spatial patterns of fluvial erosion and that the nature of these patterns changes for storm events with differing return periods. Furthermore, we hypothesize that differences in the erosion patterns modify the topography over the long term in a way that promotes and/or inhibits the other streamflow generation mechanisms. In order to test these hypotheses, a detailed hydrologic model is imbedded into an existing landscape evolution model. Precipitation events are simulated with a Poisson process and have random intensities and durations. The precipitation is partitioned between Horton runoff and infiltration to groundwater using a specified infiltration capacity. Groundwater flow is described by a two-dimensional Dupuit equation for a homogeneous, isotropic, unconfined aquifer with an irregular underlying impervious layer. Dunne runoff occurs when precipitation falls on locations where the water table reaches the land surface. The combined hydrologic/geomorphic model is applied to the WE-38 basin, an experimental watershed in Pennsylvania that has substantial available hydrologic data. First, the hydrologic model is calibrated to reproduce the observed streamflow for 1990 using the observed rainfall as the input. Then, the relative roles of Horton runoff, Dunne runoff, and groundwater discharge are controlled by varying the infiltration capacity of the soil. For each infiltration capacity, the hydrologic and geomorphic behavior of the current topography is analyzed and the long-term evolution of the basin is simulated. The results indicate that the topography can be divided into three types of locations (unsaturated, saturated, and intermittently saturated) which control the patterns of streamflow generation for events with different return periods. The results also indicate that the streamflow generation processes can produce different geomorphic effective events at upstream and downstream locations. The model also suggests that a topography dominated by groundwater discharge evolves over a long period of time to a shape that tends to inhibit the development of saturated areas and Dunne runoff.

Quantitative Photochemical Immobilization of Biomolecules on Planar and Corrugated Substrates: A Versatile Strategy for Creating Functional Biointerfaces

PubMed Central

Martin, Teresa A.; Herman, Christine T.; Limpoco, Francis T.; Michael, Madeline C.; Potts, Gregory K.; Bailey, Ryan C.

2014-01-01

Methods for the generation of substrates presenting biomolecules in a spatially controlled manner are enabling tools for applications in biosensor systems, microarray technologies, fundamental biological studies and biointerface science. We have implemented a method to create biomolecular patterns by using light to control the direct covalent immobilization of biomolecules onto benzophenone-modified glass substrates. We have generated substrates presenting up to three different biomolecules patterned in sequence, and demonstrate biomolecular photopatterning on corrugated substrates. The chemistry of the underlying monolayer was optimized to incorporate poly(ethylene glycol) to enable adhesive cell adhesion onto patterned extracellular matrix proteins. Substrates were characterized with contact angle goniometry, AFM, and immunofluorescence microscopy. Importantly, radioimmunoassays were performed to quantify the site density of immobilized biomolecules on photopatterned substrates. Retention of function of photopatterned proteins was demonstrated both by native ligand recognition and cell adhesion to photopatterned substrates, revealing that substrates generated with this method are suitable for probing specific cell receptor-ligand interactions. This molecularly general photochemical patterning method is an enabling tool that will allow the creation of substrates presenting both biochemical and topographical variation, which is an important feature of many native biointerfaces. PMID:21793535

A model-based exploration of the role of pattern generating circuits during locomotor adaptation.

PubMed

Marjaninejad, Ali; Finley, James M

2016-08-01

In this study, we used a model-based approach to explore the potential contributions of central pattern generating circuits (CPGs) during adaptation to external perturbations during locomotion. We constructed a neuromechanical modeled of locomotion using a reduced-phase CPG controller and an inverted pendulum mechanical model. Two different forms of locomotor adaptation were examined in this study: split-belt treadmill adaptation and adaptation to a unilateral, elastic force field. For each simulation, we first examined the effects of phase resetting and varying the model's initial conditions on the resulting adaptation. After evaluating the effect of phase resetting on the adaptation of step length symmetry, we examined the extent to which the results from these simple models could explain previous experimental observations. We found that adaptation of step length symmetry during split-belt treadmill walking could be reproduced using our model, but this model failed to replicate patterns of adaptation observed in response to force field perturbations. Given that spinal animal models can adapt to both of these types of perturbations, our findings suggest that there may be distinct features of pattern generating circuits that mediate each form of adaptation.

Realization of all-optical switch and diode via Raman gain process using a Kerr field

NASA Astrophysics Data System (ADS)

Abbas, Muqaddar; Qamar, Sajid; Qamar, Shahid

2016-08-01

The idea of optical photonic crystal, which is generated using two counter-propagating fields, is revisited to study gain-assisted all-optical switch and diode using Kerr field. Two counter-propagating fields with relative detuning Δ ν generate standing-wave field pattern which interacts with a four-level atomic system. The standing-wave field pattern acts like a static photonic crystal for Δ ν =0 , however, it behaves as a moving photonic crystal for Δ ν \

Design Flexibility for Uncertain Distributed Generation from Photovoltaics

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

Palmintier, Bryan; Krishnamurthy, Dheepak; Wu, Hongyu

2016-12-12

Uncertainty in the future adoption patterns for distributed energy resources (DERs) introduces a challenge for electric distribution system planning. This paper explores the potential for flexibility in design - also known as real options - to identify design solutions that may never emerge when future DER patterns are treated as deterministic. A test case for storage system design with uncertain distributed generation for solar photovoltaics (DGPV) demonstrates this approach and is used to study sensitivities to a range of techno-economic assumptions.

Vapor-Generator Wand Helps To Reveal Airflow Patterns

NASA Technical Reports Server (NTRS)

Robelen, David B.

1993-01-01

In vapor-generator wand, liquid propylene glycol flows into electrically heated stainless-steel tube. Liquid boils in heated tube, and emerging vapor forms dense, smoke-like fog used to make airflow patterns visible. Built in variety of sizes, suitable for uses ranging from tabletop demonstrations to research in wind tunnels. For best viewing, plume illuminated by bright, focused incandescent spotlight at right angle to viewing direction. Viewing further enhanced by coating walls of test chamber with flat, dark color to minimize reflections and increase contrast.

The anticipatory profile. An attempt to describe anticipation as process

NASA Astrophysics Data System (ADS)

Nadin, Mihai

2012-01-01

Inductive class representation and the more comprehensive evolving transformation system (ETS) are congenial to the subject matter of anticipation. In substantiating this assertion, we examine the epistemological premises of a new form of representation, of interest to pattern recognition and Artificial Intelligence (AI), but even more to the study of living systems. Some concepts, such as classes, time and time scale, and generative processes are examined in detail with respect to their pertinence to anticipation. Finally, pattern generation and ETS programming are suggested.

Dune field pattern formation and recent transporting winds in the Olympia Undae Dune Field, north polar region of Mars

NASA Astrophysics Data System (ADS)

Ewing, Ryan C.; Peyret, Aymeric-Pierre B.; Kocurek, Gary; Bourke, Mary

2010-08-01

High-Resolution Imaging Science Experiment (HiRISE) imagery of the central Olympia Undae Dune Field in the north polar region of Mars shows a reticulate dune pattern consisting of two sets of nearly orthogonal dune crestlines, with apparent slipfaces on the primary crests, ubiquitous wind ripples, areas of coarse-grained wind ripples, and deflated interdune areas. Geomorphic evidence and dune field pattern analysis of dune crest length, spacing, defect density, and orientation indicates that the pattern is complex, representing two constructional generations of dunes. The oldest and best-organized generation forms the primary crestlines and is transverse to circumpolar easterly winds. Gross bed form-normal analysis of the younger pattern of crestlines indicates that it emerged with both circumpolar easterly winds and NE winds and is reworking the older pattern. Mapping of secondary flow fields over the dunes indicates that the most recent transporting winds were from the NE. The younger pattern appears to represent an influx of sediment to the dune field associated with the development of the Olympia Cavi reentrant, with NE katabatic winds channeling through the reentrant. A model of the pattern reformation based upon the reconstructed primary winds and resulting secondary flow fields shows that the development of the secondary pattern is controlled by the boundary condition of the older dune topography.

Experimental verification of multilevel spatial pattern generation from binary data page with four-step phase pattern (Conference Presentation)

NASA Astrophysics Data System (ADS)

Barada, Daisuke; Yatagai, Toyohiko

2016-09-01

Holographic memory is expected for cold storage because of the features of huge data capacity, high data transfer rate, and long life time. In holographic memory, a signal beam is modulated by a spatial light modulator according to data pages. The recording density is dependent on information amount per pixel in a data page. However, a binary spatial light modulator is used to realize high data transfer rate in general. In our previous study, an optical conversion method from binary data to multilevel data has been proposed. In this paper, the principle of the method is experimentally verified. In the proposed method, a data page consists of symbols with 2x2 pixels and a four-step phase mask is used. Then, the complex amplitudes of four pixels in a symbol become positive real, positive imaginary, negative real, and negative imaginary values, respectively. A square pixel pattern is spread by spatial frequency filtering with a square aperture in a Fourier plane. When the aperture size is too small, the complex amplitude of four pixels in a symbol is superposed and a symbol is regarded as a pixel with a complex number. In this work, a data page pattern with a four-step phase pattern was generated by using a computer-generated circular polarization hologram (CGCPH). The CGCPH was prepared by electron beam lithography. The page data pattern is Fourier transformed by a lens and spatially filtered by a variable rectangular aperture. The complex amplitude of the spatial filtered data page pattern was measured by digital holography and the principle was experimentally verified.

Health Care Satisfaction: Effects of Immigration, Acculturation, Language.

PubMed

Schutt, Russell K; Mejía, Camila

2017-12-01

Differences in health care satisfaction can alter patterns of health care utilization and so affect health outcomes, but little is known about variation in satisfaction in relation to immigration status. Health care satisfaction is analyzed with survey data from state public health program patients. Overall health care satisfaction is higher for first generation Hispanic immigrants and lower among those in the second generation compared to white Americans-consistent with the pattern termed the "healthy migrant effect." This pattern is more pronounced for Portuguese-speaking immigrants and is not explained by self-reported health, communication ability or acculturation. Satisfaction with specific aspects of health care follows different patterns that may be explained by differences in experiences and culture. As anticipated by segmented assimilation theory, we find variation in cross-generational patterns of health care satisfaction both within and between ethnic groups. This variation indicates the importance of distinguishing Portuguese-speakers from Spanish-speakers and of taking into account differences in the ways they are able to communicate with health care providers as well as differences in their orientations toward health care. Our disparate findings with other immigrant groups also reinforce limiting expectations of a "healthy migrant effect" to Latinos. Finally, the variable influences on different satisfaction measures indicate the importance of considering the relative influence of culturally-based orientations and health care experiences on the specific outcomes measured, with particular sensitivity to acceptance of individualized standards of care.

Cross-diffusion-induced subharmonic spatial resonances in a predator-prey system

NASA Astrophysics Data System (ADS)

Gambino, G.; Lombardo, M. C.; Sammartino, M.

2018-01-01

In this paper we investigate the complex dynamics originated by a cross-diffusion-induced subharmonic destabilization of the fundamental subcritical Turing mode in a predator-prey reaction-diffusion system. The model we consider consists of a two-species Lotka-Volterra system with linear diffusion and a nonlinear cross-diffusion term in the predator equation. The taxis term in the search strategy of the predator is responsible for the onset of complex dynamics. In fact, our model does not exhibit any Hopf or wave instability, and on the basis of the linear analysis one should only expect stationary patterns; nevertheless, the presence of the nonlinear cross-diffusion term is able to induce a secondary instability: due to a subharmonic spatial resonance, the stationary primary branch bifurcates to an out-of-phase oscillating solution. Noticeably, the strong resonance between the harmonic and the subharmonic is able to generate the oscillating pattern albeit the subharmonic is below criticality. We show that, as the control parameter is varied, the oscillating solution (sub T mode) can undergo a sequence of secondary instabilities, generating a transition toward chaotic dynamics. Finally, we investigate the emergence of sub T -mode solutions on two-dimensional domains: when the fundamental mode describes a square pattern, subharmonic resonance originates oscillating square patterns. In the case of subcritical Turing hexagon solutions, the internal interactions with a subharmonic mode are able to generate the so-called "twinkling-eyes" pattern.

Design and implementation of integrated solid wastes management pattern in industrial zones, case study of Shahroud, Iran.

PubMed

Saeid, Nazemi; Roudbari, Aliakbar; Yaghmaeian, Kamyar

2014-01-14

The aim of the study was to design and implementation of integrated solid wastes management pattern in Shahroud industrial zone, evaluates the results and determine possible performance problems. This cross - sectional study was carried out for 4 years in Shahroud industrial zone and the implementation process included:1- Qualitative and quantitative analysis of all solid waste generated in the city, 2- determine the current state of solid waste management in the zone and to identify programs conducted, 3- Design and implementation of integrated solid wastes management pattern including design and implementation of training programs, laws, penalties and incentives and explain and implement programs for all factories and 4- The monitoring of the implementation process and determine the results. Annually, 1,728 tons of solid wastes generated in the town including 1603 tons of industrial wastes and 125 tons of municipal wastes. By implementing this pattern, the two separated systems of collection and recycling of domestic and industrial wastes was launched in this zone. Also consistent with the goals, the amount of solid wastes generated and disposed in 2009 was 51.5 and 28.6 kg per 100 million Rials production, respectively. Results showed that implementation of pattern of separated collection, training programs, capacity building, providing technical services, completing chain of industries and strengthening the cooperation between industrial estate management and industrial units could greatly reduce the waste management problems.

[Congenital talipes equinovarus--family occurrence].

PubMed

Kołecka, Ewa; Niedzielski, Kryspin Ryszard; Cukras, Zbigniew; Piotrowicz, Małgorzata

2011-01-01

Although congenital talipes equinovarus (CTEV) is one of the most frequently occurring congenital defects of locomotor organs, its ethiopathogenesis is still not fully known. Amongst the others, the inheritance patterns of that defect are not fully known, and that restricts genetic therapeutics and development of new treatment technologies. The aim of this study was analysis of family lineages of 205 children with CTEV (298 feet) treated at our centre in the years 1998-2008. The family occurrence of CTEV was found in 16 cases (8% of analysed group). 6 lineages, in which CTEV occurred in successive generations, were analysed in detail. Particularly interesting is the lineage of the family 1, in which the defect occurred in three successive generations. In case of that family, an autosomal dominant inheritance pattern is possible. Previously that pattern of CTEV inheritance was described only for isolated populations of Polynesians. In own material the family occurrence of CTEV was found to be less frequent than in bibliographic references. The defect occurred twice as often in boys, while the severe form was more frequently observed in girls, and that is consisted with data in the available bibliography. The analysis of presented lineages of families with CTEV did not allow unambiguous defining of the inheritance pattern for that defect. To confirm the autosomal dominant pattern of CTEV inheritance in the family in which the defect occurred in three successive generations, genetic tests would be necessary.

The importance of topographically corrected null models for analyzing ecological point processes.

PubMed

McDowall, Philip; Lynch, Heather J

2017-07-01

Analyses of point process patterns and related techniques (e.g., MaxEnt) make use of the expected number of occurrences per unit area and second-order statistics based on the distance between occurrences. Ecologists working with point process data often assume that points exist on a two-dimensional x-y plane or within a three-dimensional volume, when in fact many observed point patterns are generated on a two-dimensional surface existing within three-dimensional space. For many surfaces, however, such as the topography of landscapes, the projection from the surface to the x-y plane preserves neither area nor distance. As such, when these point patterns are implicitly projected to and analyzed in the x-y plane, our expectations of the point pattern's statistical properties may not be met. When used in hypothesis testing, we find that the failure to account for the topography of the generating surface may bias statistical tests that incorrectly identify clustering and, furthermore, may bias coefficients in inhomogeneous point process models that incorporate slope as a covariate. We demonstrate the circumstances under which this bias is significant, and present simple methods that allow point processes to be simulated with corrections for topography. These point patterns can then be used to generate "topographically corrected" null models against which observed point processes can be compared. © 2017 by the Ecological Society of America.

Operant conditioning of synaptic and spiking activity patterns in single hippocampal neurons.

PubMed

Ishikawa, Daisuke; Matsumoto, Nobuyoshi; Sakaguchi, Tetsuya; Matsuki, Norio; Ikegaya, Yuji

2014-04-02

Learning is a process of plastic adaptation through which a neural circuit generates a more preferable outcome; however, at a microscopic level, little is known about how synaptic activity is patterned into a desired configuration. Here, we report that animals can generate a specific form of synaptic activity in a given neuron in the hippocampus. In awake, head-restricted mice, we applied electrical stimulation to the lateral hypothalamus, a reward-associated brain region, when whole-cell patch-clamped CA1 neurons exhibited spontaneous synaptic activity that met preset criteria. Within 15 min, the mice learned to generate frequently the excitatory synaptic input pattern that satisfied the criteria. This reinforcement learning of synaptic activity was not observed for inhibitory input patterns. When a burst unit activity pattern was conditioned in paired and nonpaired paradigms, the frequency of burst-spiking events increased and decreased, respectively. The burst reinforcement occurred in the conditioned neuron but not in other adjacent neurons; however, ripple field oscillations were concomitantly reinforced. Neural conditioning depended on activation of NMDA receptors and dopamine D1 receptors. Acutely stressed mice and depression model mice that were subjected to forced swimming failed to exhibit the neural conditioning. This learning deficit was rescued by repetitive treatment with fluoxetine, an antidepressant. Therefore, internally motivated animals are capable of routing an ongoing action potential series into a specific neural pathway of the hippocampal network.

Fast in-situ tool inspection based on inverse fringe projection and compact sensor heads

NASA Astrophysics Data System (ADS)

Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

2016-11-01

Inspection of machine elements is an important task in production processes in order to ensure the quality of produced parts and to gather feedback for the continuous improvement process. A new measuring system is presented, which is capable of performing the inspection of critical tool geometries, such as gearing elements, inside the forming machine. To meet the constraints on sensor head size and inspection time imposed by the limited space inside the machine and the cycle time of the process, the measuring device employs a combination of endoscopy techniques with the fringe projection principle. Compact gradient index lenses enable a compact design of the sensor head, which is connected to a CMOS camera and a flexible micro-mirror based projector via flexible fiber bundles. Using common fringe projection patterns, the system achieves measuring times of less than five seconds. To further reduce the time required for inspection, the generation of inverse fringe projection patterns has been implemented for the system. Inverse fringe projection speeds up the inspection process by employing object-adapted patterns, which enable the detection of geometry deviations in a single image. Two different approaches to generate object adapted patterns are presented. The first approach uses a reference measurement of a manufactured tool master to generate the inverse pattern. The second approach is based on a virtual master geometry in the form of a CAD file and a ray-tracing model of the measuring system. Virtual modeling of the measuring device and inspection setup allows for geometric tolerancing for free-form surfaces by the tool designer in the CAD-file. A new approach is presented, which uses virtual tolerance specifications and additional simulation steps to enable fast checking of metric tolerances. Following the description of the pattern generation process, the image processing steps required for inspection are demonstrated on captures of gearing geometries.

Transmission patterns of smallpox: systematic review of natural outbreaks in Europe and North America since World War II.

PubMed

Bhatnagar, Vibha; Stoto, Michael A; Morton, Sally C; Boer, Rob; Bozzette, Samuel A

2006-05-05

Because smallpox (variola major) may be used as a biological weapon, we reviewed outbreaks in post-World War II Europe and North America in order to understand smallpox transmission patterns. A systematic review was used to identify papers from the National Library of Medicine, Embase, Biosis, Cochrane Library, Defense Technical Information Center, WorldCat, and reference lists of included publications. Two authors reviewed selected papers for smallpox outbreaks. 51 relevant outbreaks were identified from 1,389 publications. The median for the effective first generation reproduction rate (initial R) was 2 (range 0-38). The majority outbreaks were small (less than 5 cases) and contained within one generation. Outbreaks with few hospitalized patients had low initial R values (median of 1) and were prolonged if not initially recognized (median of 3 generations); outbreaks with mostly hospitalized patients had higher initial R values (median 12) and were shorter (median of 3 generations). Index cases with an atypical presentation of smallpox were less likely to have been diagnosed with smallpox; outbreaks in which the index case was not correctly diagnosed were larger (median of 27.5 cases) and longer (median of 3 generations) compared to outbreaks in which the index case was correctly diagnosed (median of 3 cases and 1 generation). Patterns of spread during Smallpox outbreaks varied with circumstances, but early detection and implementation of control measures is a most important influence on the magnitude of outbreaks. The majority of outbreaks studied in Europe and North America were controlled within a few generations if detected early.

Variation in motor output and motor performance in a centrally generated motor pattern

PubMed Central

Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

2014-01-01

Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved. PMID:24717348

Age Differences and Educational Attainment across the Life Span on Three Generations of Wechsler Adult Scales

ERIC Educational Resources Information Center

Kaufman, A. S.; Salthouse, T. A.; Scheiber, C.; Chen, H.

2016-01-01

Patterns of maintenance of ability across the life span have been documented on tests of knowledge ("Gc"), as have patterns of steady decline on measures of reasoning ("Gf/Gv"), working memory ("Gsm"), and speed ("Gs"). Whether these patterns occur at the same rate for adults from different educational…

Brainstem Circuits that Control Mastication: Do They Have Anything to Say during Speech?

ERIC Educational Resources Information Center

Lund, James P.; Kolta, Arlette

2006-01-01

Mastication results from the interaction of an intrinsic rhythmical neural pattern and sensory feedback from the mouth, muscles and joints. The pattern is matched to the physical characteristics of food, but also varies with age. There are large differences in masticatory movements among subjects. The intrinsic rhythmical pattern is generated by…

Comparison of Computational-Model and Experimental-Example Trained Neural Networks for Processing Speckled Fringe Patterns

NASA Technical Reports Server (NTRS)

Decker, A. J.; Fite, E. B.; Thorp, S. A.; Mehmed, O.

1998-01-01

The responses of artificial neural networks to experimental and model-generated inputs are compared for detection of damage in twisted fan blades using electronic holography. The training-set inputs, for this work, are experimentally generated characteristic patterns of the vibrating blades. The outputs are damage-flag indicators or second derivatives of the sensitivity-vector-projected displacement vectors from a finite element model. Artificial neural networks have been trained in the past with computational-model-generated training sets. This approach avoids the difficult inverse calculations traditionally used to compare interference fringes with the models. But the high modeling standards are hard to achieve, even with fan-blade finite-element models.

Comparison of Computational, Model and Experimental, Example Trained Neural Networks for Processing Speckled Fringe Patterns

NASA Technical Reports Server (NTRS)

Decker, A. J.; Fite, E. B.; Thorp, S. A.; Mehmed, O.

1998-01-01

The responses of artificial neural networks to experimental and model-generated inputs are compared for detection of damage in twisted fan blades using electronic holography. The training-set inputs, for this work, are experimentally generated characteristic patterns of the vibrating blades. The outputs are damage-flag indicators or second derivatives of the sensitivity-vector-projected displacement vectors from a finite element model. Artificial neural networks have been trained in the past with computational-model- generated training sets. This approach avoids the difficult inverse calculations traditionally used to compare interference fringes with the models. But the high modeling standards are hard to achieve, even with fan-blade finite-element models.

Multiple layer optical memory system using second-harmonic-generation readout

DOEpatents

Boyd, Gary T.; Shen, Yuen-Ron

1989-01-01

A novel optical read and write information storage system is described which comprises a radiation source such as a laser for writing and illumination, the radiation source being capable of radiating a preselected first frequency; a storage medium including at least one layer of material for receiving radiation from the radiation source and capable of being surface modified in response to said radiation source when operated in a writing mode and capable of generating a pattern of radiation of the second harmonic of the preselected frequency when illuminated by the radiation source at the preselected frequency corresponding to the surface modifications on the storage medium; and a detector to receive the pattern of second harmonic frequency generated.

Development of human locomotion.

PubMed

Lacquaniti, Francesco; Ivanenko, Yuri P; Zago, Myrka

2012-10-01

Neural control of locomotion in human adults involves the generation of a small set of basic patterned commands directed to the leg muscles. The commands are generated sequentially in time during each step by neural networks located in the spinal cord, called Central Pattern Generators. This review outlines recent advances in understanding how motor commands are expressed at different stages of human development. Similar commands are found in several other vertebrates, indicating that locomotion development follows common principles of organization of the control networks. Movements show a high degree of flexibility at all stages of development, which is instrumental for learning and exploration of variable interactions with the environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Morphological computation of multi-gaited robot locomotion based on free vibration.

PubMed

Reis, Murat; Yu, Xiaoxiang; Maheshwari, Nandan; Iida, Fumiya

2013-01-01

In recent years, there has been increasing interest in the study of gait patterns in both animals and robots, because it allows us to systematically investigate the underlying mechanisms of energetics, dexterity, and autonomy of adaptive systems. In particular, for morphological computation research, the control of dynamic legged robots and their gait transitions provides additional insights into the guiding principles from a synthetic viewpoint for the emergence of sensible self-organizing behaviors in more-degrees-of-freedom systems. This article presents a novel approach to the study of gait patterns, which makes use of the intrinsic mechanical dynamics of robotic systems. Each of the robots consists of a U-shaped elastic beam and exploits free vibration to generate different locomotion patterns. We developed a simplified physics model of these robots, and through experiments in simulation and real-world robotic platforms, we show three distinctive mechanisms for generating different gait patterns in these robots.

3D absolute shape measurement of live rabbit hearts with a superfast two-frequency phase-shifting technique

PubMed Central

Wang, Yajun; Laughner, Jacob I.; Efimov, Igor R.; Zhang, Song

2013-01-01

This paper presents a two-frequency binary phase-shifting technique to measure three-dimensional (3D) absolute shape of beating rabbit hearts. Due to the low contrast of the cardiac surface, the projector and the camera must remain focused, which poses challenges for any existing binary method where the measurement accuracy is low. To conquer this challenge, this paper proposes to utilize the optimal pulse width modulation (OPWM) technique to generate high-frequency fringe patterns, and the error-diffusion dithering technique to produce low-frequency fringe patterns. Furthermore, this paper will show that fringe patterns produced with blue light provide the best quality measurements compared to fringe patterns generated with red or green light; and the minimum data acquisition speed for high quality measurements is around 800 Hz for a rabbit heart beating at 180 beats per minute. PMID:23482151

Three-dimensional spatiotemporal focusing of holographic patterns

PubMed Central

Hernandez, Oscar; Papagiakoumou, Eirini; Tanese, Dimitrii; Fidelin, Kevin; Wyart, Claire; Emiliani, Valentina

2016-01-01

Two-photon excitation with temporally focused pulses can be combined with phase-modulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes. Adding lens-phase modulations to 2D-phase holograms enables remote axial pattern displacement as well as simultaneous pattern generation in multiple distinct planes. However, the axial confinement linearly degrades with lateral shape area in previous reports where axially shifted holographic shapes were not temporally focused. Here we report an optical system using two spatial light modulators to independently control transverse- and axial-target light distribution. This approach enables simultaneous axial translation of single or multiple spatiotemporally focused patterns across the sample volume while achieving the axial confinement of temporal focusing. We use the system's capability to photoconvert tens of Kaede-expressing neurons with single-cell resolution in live zebrafish larvae. PMID:27306044

Simple robot suggests physical interlimb communication is essential for quadruped walking

PubMed Central

Owaki, Dai; Kano, Takeshi; Nagasawa, Ko; Tero, Atsushi; Ishiguro, Akio

2013-01-01

Quadrupeds have versatile gait patterns, depending on the locomotion speed, environmental conditions and animal species. These locomotor patterns are generated via the coordination between limbs and are partly controlled by an intraspinal neural network called the central pattern generator (CPG). Although this forms the basis for current control paradigms of interlimb coordination, the mechanism responsible for interlimb coordination remains elusive. By using a minimalistic approach, we have developed a simple-structured quadruped robot, with the help of which we propose an unconventional CPG model that consists of four decoupled oscillators with only local force feedback in each leg. Our robot exhibits good adaptability to changes in weight distribution and walking speed simply by responding to local feedback, and it can mimic the walking patterns of actual quadrupeds. Our proposed CPG-based control method suggests that physical interaction between legs during movements is essential for interlimb coordination in quadruped walking. PMID:23097501

Simple robot suggests physical interlimb communication is essential for quadruped walking.

PubMed

Owaki, Dai; Kano, Takeshi; Nagasawa, Ko; Tero, Atsushi; Ishiguro, Akio

2013-01-06

Quadrupeds have versatile gait patterns, depending on the locomotion speed, environmental conditions and animal species. These locomotor patterns are generated via the coordination between limbs and are partly controlled by an intraspinal neural network called the central pattern generator (CPG). Although this forms the basis for current control paradigms of interlimb coordination, the mechanism responsible for interlimb coordination remains elusive. By using a minimalistic approach, we have developed a simple-structured quadruped robot, with the help of which we propose an unconventional CPG model that consists of four decoupled oscillators with only local force feedback in each leg. Our robot exhibits good adaptability to changes in weight distribution and walking speed simply by responding to local feedback, and it can mimic the walking patterns of actual quadrupeds. Our proposed CPG-based control method suggests that physical interaction between legs during movements is essential for interlimb coordination in quadruped walking.

Continuities and changes in infant attachment patterns across two generations.

PubMed

Raby, K Lee; Steele, Ryan D; Carlson, Elizabeth A; Sroufe, L Alan

2015-01-01

This study examined the intergenerational continuities and changes in infant attachment patterns within a higher-risk longitudinal sample of 55 female participants born into poverty. Infant attachment was assessed using the Strange Situation when participants were 12 and 18 months as well as several decades later with participants' children. Paralleling earlier findings from this sample on the stability of attachment patterns from infancy to young adulthood, results provided evidence for intergenerational continuities in attachment disorganization but not security. Children of adults with histories of infant attachment disorganization were at an increased risk of forming disorganized attachments. Although changes in infant attachment patterns across the two generations were not correlated with individuals' caregiving experiences or interpersonal stresses and supports during childhood and adolescence, higher quality social support during adulthood was associated with intergenerational changes from insecure to secure infant-caregiver attachment relationships.

Continuities and Changes in Infant Attachment Patterns Across Two Generations

PubMed Central

Raby, K. Lee; Steele, Ryan D.; Carlson, Elizabeth A.; Sroufe, L. Alan

2015-01-01

This study examined the intergenerational continuities and changes in infant attachment patterns within a higher-risk longitudinal sample of 55 female participants born into poverty. Infant attachment was assessed using the Strange Situation when participants were 12 and 18 months as well as several decades later with participants’ children. Paralleling earlier findings from this sample on the stability of attachment patterns from infancy to young adulthood, results provided evidence for intergenerational continuities in attachment disorganization but not security. Children of adults with histories of infant attachment disorganization were at an increased risk of forming disorganized attachments. Although changes in infant attachment patterns across the two generations were not correlated with individuals’ caregiving experiences or interpersonal stresses and supports during childhood and adolescence, higher quality social support during adulthood was associated with intergenerational changes from insecure to secure infant-caregiver attachment relationships. PMID:26213155

Storage of sparse files using parallel log-structured file system

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

Bent, John M.; Faibish, Sorin; Grider, Gary

A sparse file is stored without holes by storing a data portion of the sparse file using a parallel log-structured file system; and generating an index entry for the data portion, the index entry comprising a logical offset, physical offset and length of the data portion. The holes can be restored to the sparse file upon a reading of the sparse file. The data portion can be stored at a logical end of the sparse file. Additional storage efficiency can optionally be achieved by (i) detecting a write pattern for a plurality of the data portions and generating a singlemore » patterned index entry for the plurality of the patterned data portions; and/or (ii) storing the patterned index entries for a plurality of the sparse files in a single directory, wherein each entry in the single directory comprises an identifier of a corresponding sparse file.« less

Frequency and amplitude dependences of molding accuracy in ultrasonic nanoimprint technology

NASA Astrophysics Data System (ADS)

Mekaru, Harutaka; Takahashi, Masaharu

2009-12-01

We use neither a heater nor ultraviolet lights, and are researching and developing an ultrasonic nanoimprint as a new nano-patterning technology. In our ultrasonic nanoimprint technology, ultrasonic vibration is not used as a heat generator instead of the heater. A mold is connected with an ultrasonic generator, and mold patterns are pushed down and pulled up at a high speed into a thermoplastic. Frictional heat is generated by ultrasonic vibration between mold patterns and thermoplastic patterns formed by an initial contact force. However, because frictional heat occurs locally, the whole mold is not heated. Therefore, a molding material can be comprehensively processed at room temperature. A magnetostriction actuator was built into our ultrasonic nanoimprint system as an ultrasonic generator, and the frequency and amplitude can be changed between dc-10 kHz and 0-4 µm, respectively. First, the ultrasonic nanoimprint was experimented by using this system on polyethylene terephthalate (PET, Tg = 69 °C), whose the glass transition temperature (Tg) is comparatively low in engineering plastics, and it was ascertained that the most suitable elastic material for this technique was an ethyl urethane rubber. In addition, we used a changeable frequency of the magnetostriction actuator, and nano-patterns in an electroformed-Ni mold were transferred to a 0.5 mm thick sheet of PET, polymethylmethacrylate (PMMA) and polycarbonate (PC), which are typical engineering plastics, under variable molding conditions. The frequency and amplitude dependence of ultrasonic vibration to the molding accuracy were investigated by measuring depth and width of imprinted patterns. As a result, regardless of the molding material, the imprinted depth was changed drastically when the frequency exceeded 5 kHz. On the other hand, when the amplitude of ultrasonic vibration grew, the imprinted depth gradually deepened. Influence of the frequency and amplitude of ultrasonic vibration was not observed on the width of imprinted patterns. Moreover, the imprinted depth deepened as the Tg of the molding material lowered, and a progressive change according to conditions of ultrasonic vibration also became remarkable. Therefore, it seems that impressing ultrasonic vibration with a high frequency and large amplitude promotes thermal deformation and improves the molding accuracy in the ultrasonic nanoimprint technology.

Feedback of Erosional-Depositional Processes Generating Anabranching Patterns in a Mega-River the Case of the PARANÁ River, Argentina

NASA Astrophysics Data System (ADS)

Latrubesse, E. M.; Pereira, M.; Ramonell, C. G.; Szupiany, R. N.

2011-12-01

A new category of "very large" rivers was recently proposed and defined as mega-rivers, which are those rivers with a Qmean of more than ~17,000m3/s. This category includes the nine largest rivers on Earth and the Parana River is one of the selected members of that peculiar group. The planform adjustment of mega-rivers is a variety of anabranching patterns characterized by the existence of alluvial islands. The processes and mechanisms involved in the generation of the different anabranching styles, however, are not well understood. The Paraná channel pattern has been classified as a low to moderate anabranching, low sinuosity with tendency to braided and having a meandering thalweg. We analyzed a reach of the middle Paraná in Argentina applying a combined multitemporal, hydraulic, sedimentologic and geomorphologic approach. Multitemporal geomorphologic maps, sedimentary descriptions of bars, islands and banks, volumetric calculations using multitemporal bathymetric charts, measurements with ADCP and bathymetric surveys with echosound, sediment transport estimations and the hydrological analysis of available data from gauge stations were some of the tools used in our research. The evolution of the reach was studied from 1908 to present. The reach is subdivided in two sub-reaches (named Chapeton and Curtiembre) which are comprised between nodal points. Chapeton has been in a more mature quasi-equilibrium state through the XX Century but the main channel in Curtiembre evolved from a single pattern to anabranching pattern since 1950s. We conclude that the generation of the anabranching pattern in the studied reach depends of a combination of factors such as the architecture of the floodplain and islands, the main role played by the morphodynamics and shifting of the thalweg, the availability and path of sandy sediments bedforms architecture and the temporal variability of the effective discharge among other secondary factors. A feedback system coupling erosional/depositional processes at the decadal scale seems to be the main responsible for the generation of the complex anabranching pattern in such subreaches.

Stretchable Kirigami Polyvinylidene Difluoride Thin Films for Energy Harvesting: Design, Analysis, and Performance

NASA Astrophysics Data System (ADS)

Hu, Nan; Chen, Dajing; Wang, Dong; Huang, Shicheng; Trase, Ian; Grover, Hannah M.; Yu, Xiaojiao; Zhang, John X. J.; Chen, Zi

2018-02-01

Kirigami, a modified form of origami which includes cutting, has been used to improve material stretchability and compliance. However, this technique is, so far, underexplored in patterning piezoelectric materials towards developing efficient and mechanically flexible thin-film energy generators. Motivated by existing kirigami-based applications, we introduce interdigitated cuts to polyvinylidene fluoride (PVDF) films to evaluate the effect on voltage generation and stretchability. Our results from theoretical analysis, numerical simulations, and experimental tests show that kirigami PVDF films exhibit an extended strain range while still maintaining significant voltage generation compared to films without cuts. Various cutting patterns are studied, and it is found that films with denser cuts have a larger voltage output. This kirigami design can enhance the properties of existing piezoelectric materials and help to integrate tunable PVDF generators into biomedical devices.

Low-frequency ultrasonic Bessel-like collimated beam generation from radial modes of piezoelectric transducers

DOE PAGES

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

2017-02-06

We present a very simple approach to generate a collimated ultrasonic beam that exploits the natural Bessel-like vibration pattern of the radial modes of a piezoelectric disc with lateral clamping. This eliminates the need for the conventional annular Bessel pattern of the electrodes with individual electrode excitation on the piezo-disc, thus simplifying the transducer design. Numerical and experimental studies are carried out to investigate the Bessel-like vibration patterns of these radial modes showing an excellent agreement between these two studies. Measured ultrasonic beam- pro les in water from the radial modes con rm the profile to be a Bessel beam.more » Collimated beam generation from radial modes is investigated using a coupled electromechanical finite-element model. It is found that clamping the lateral edges of piezoelectric transducers results in a high-degree of collimation with practically no side-lobes similar to a parametric array beam. Ultrasonic beam- profile measurements in water with both free and clamped piezoelectric transducer are presented. The collimated beam generation using the present technique of using the laterally clamped radial modes finds significant applications in low-frequency imaging through highly attenuating materials.« less

Temperature-dependent regulation of vocal pattern generator.

PubMed

Yamaguchi, Ayako; Gooler, David; Herrold, Amy; Patel, Shailja; Pong, Winnie W

2008-12-01

Vocalizations of Xenopus laevis are generated by central pattern generators (CPGs). The advertisement call of male X. laevis is a complex biphasic motor rhythm consisting of fast and slow trills (a train of clicks). We found that the trill rate of these advertisement calls is sensitive to temperature and that this rate modification of the vocal rhythms originates in the central pattern generators. In vivo the rates of fast and slow trills increased linearly with an increase in temperature. In vitro a similar linear relation between temperature and compound action potential frequency in the laryngeal nerve was found when fictive advertisement calls were evoked in the isolated brain. Temperature did not limit the contractile properties of laryngeal muscles within the frequency range of vocalizations. We next took advantage of the temperature sensitivity of the vocal CPG in vitro to localize the source of the vocal rhythms. We focused on the dorsal tegmental area of the medulla (DTAM), a brain stem nucleus that is essential for vocal production. We found that bilateral cooling of DTAM reduced both fast and slow trill rates. Thus we conclude that DTAM is a source of biphasic vocal rhythms.

Possible disruption of remote viewing by complex weak magnetic fields around the stimulus site and the possibility of accessing real phase space: a pilot study.

PubMed

Koren, S A; Persinger, M A

2002-12-01

In 2002 Persinger, Roll, Tiller, Koren, and Cook considered whether there are physical processes by which recondite information exists within the space and time of objects or events. The stimuli that compose this information might be directly detected within the whole brain without being processed by the typical sensory modalities. We tested the artist Ingo Swann who can reliably draw and describe randomly selected photographs sealed in envelopes in another room. In the present experiment the photographs were immersed continuously in repeated presentations (5 times per sec.) of one of two types of computer-generated complex magnetic field patterns whose intensities were less than 20 nT over most of the area. WINDOWS-generated but not DOS-generated patterns were associated with a marked decrease in Mr. Swann's accuracy. Whereas the DOS software generated exactly the same pattern, WINDOWS software phase-modulated the actual wave form resulting in an infinite bandwidth and complexity. We suggest that information obtained by processes attributed to "paranormal" phenomena have physical correlates that can be masked by weak, infinitely variable magnetic fields.

Low-frequency ultrasonic Bessel-like collimated beam generation from radial modes of piezoelectric transducers

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

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

We present a very simple approach to generate a collimated ultrasonic beam that exploits the natural Bessel-like vibration pattern of the radial modes of a piezoelectric disc with lateral clamping. This eliminates the need for the conventional annular Bessel pattern of the electrodes with individual electrode excitation on the piezo-disc, thus simplifying the transducer design. Numerical and experimental studies are carried out to investigate the Bessel-like vibration patterns of these radial modes showing an excellent agreement between these two studies. Measured ultrasonic beam- pro les in water from the radial modes con rm the profile to be a Bessel beam.more » Collimated beam generation from radial modes is investigated using a coupled electromechanical finite-element model. It is found that clamping the lateral edges of piezoelectric transducers results in a high-degree of collimation with practically no side-lobes similar to a parametric array beam. Ultrasonic beam- profile measurements in water with both free and clamped piezoelectric transducer are presented. The collimated beam generation using the present technique of using the laterally clamped radial modes finds significant applications in low-frequency imaging through highly attenuating materials.« less

Evolution of central pattern generators and rhythmic behaviours

PubMed Central

Katz, Paul S.

2016-01-01

Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization. PMID:26598733

Evolution of central pattern generators and rhythmic behaviours.

PubMed

Katz, Paul S

2016-01-05

Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization. © 2015 The Author(s).

A vertical (pseudodominant) pattern of inheritance in the autosomal recessive disease primary hyperoxaluria type 1: lack of relationship between genotype, enzymic phenotype, and disease severity.

PubMed

Hoppe, B; Danpure, C J; Rumsby, G; Fryer, P; Jennings, P R; Blau, N; Schubiger, G; Neuhaus, T; Leumann, E

1997-01-01

Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive disease caused by a deficiency of alanine:glyoxylate aminotransferase (encoded by the AGXT gene). Primary hyperoxaluria type 1 is characterized by the elevated urinary excretion of oxalate and glycolate, and the deposition of insoluble calcium oxalate in the renal parenchyma and urinary tract. In the present study, we investigated an unusual family containing four affected individuals in two different generations. Based on our genetic, enzymic, metabolic, and clinical analyses, we have come to the following conclusions. First, although the pattern of inheritance of PH1 is usually horizontal (ie, all patients in the same generation), as expected for an autosomal recessive disease, it can sometimes show a vertical (pseudodominant) pattern of inheritance (ie, patients in more than one generation) due to the segregation within a family of three, rather than two, mutant AGXT alleles. Second, affected members of such a family can manifest very different clinical phenotypes both within and between generations. Although the clinical differences between generations might be at least partly due to differences in AGXT genotype, differences can equally occur within the same generation in individuals who possess the same AGXT genotype. Finally, individuals with PH1 at the level of the AGXT genotype might remain asymptomatic and undiagnosed for many years. The consequences of these findings for the clinical management and genetic counseling of families with PH1 are profound and wide-ranging.

The effect of acculturation and discrimination on mental health symptoms and risk behaviors among adolescent migrants in Israel.

PubMed

Nakash, Ora; Nagar, Maayan; Shoshani, Anat; Zubida, Hani; Harper, Robin A

2012-07-01

This study examines the role of acculturation, perceived discrimination, and self-esteem in predicting the mental health symptoms and risk behaviors among 1.5 and second generation non-Jewish adolescents born to migrant families compared with native-born Jewish Israeli adolescents in Israel. Participants included n = 65 1.5 migrant adolescents, n = 60 second generation migrant adolescents, and n = 146 age, gender, and socioeconomic matched sample of native-born Jewish Israelis. Participants completed measures of acculturation pattern, perceived discrimination, and self-esteem as well as measures of mental health symptoms and risk behaviors. Results show that migrant adolescents across generations reported worse mental health symptoms compared with native-born Jewish Israelis. However, only the 1.5 generation migrants reported higher engagement in risk behaviors compared with second generation migrants and native-born Jewish Israelis. Our findings further showed that acculturation plays an important role in predicting the mental health status of migrant youth, with those characterized with integrated acculturative pattern reporting lower mental health symptoms compared with assimilated acculturation pattern. Importantly, contextual factors, such as higher perception of discrimination in the receiving culture as well as individual factors such as lower self-esteem and female gender were strongly associated with worse mental health symptoms. The findings manifest the complex relationship between contextual factors and individual level variables in the acculturative process of migrants as well as the importance of examining the effect of migration generation on mental health outcomes.

Tracking the unconscious generation of free decisions using ultra-high field fMRI.

PubMed

Bode, Stefan; He, Anna Hanxi; Soon, Chun Siong; Trampel, Robert; Turner, Robert; Haynes, John-Dylan

2011-01-01

Recently, we demonstrated using functional magnetic resonance imaging (fMRI) that the outcome of free decisions can be decoded from brain activity several seconds before reaching conscious awareness. Activity patterns in anterior frontopolar cortex (BA 10) were temporally the first to carry intention-related information and thus a candidate region for the unconscious generation of free decisions. In the present study, the original paradigm was replicated and multivariate pattern classification was applied to functional images of frontopolar cortex, acquired using ultra-high field fMRI at 7 Tesla. Here, we show that predictive activity patterns recorded before a decision was made became increasingly stable with increasing temporal proximity to the time point of the conscious decision. Furthermore, detailed questionnaires exploring subjects' thoughts before and during the decision confirmed that decisions were made spontaneously and subjects were unaware of the evolution of their decision outcomes. These results give further evidence that FPC stands at the top of the prefrontal executive hierarchy in the unconscious generation of free decisions.

Clinical proteomics: Applications for prostate cancer biomarker discovery and detection.

PubMed

Petricoin, Emanuel F; Ornstein, David K; Liotta, Lance A

2004-01-01

The science of proteomics comprises much more than simply generating lists of proteins that change in expression as a cause of or consequence of pathophysiology. The goal of proteomics should be to characterize the information flow through the intercellular protein circuitry that communicates with the extracellular microenvironment and then ultimately to the serum/plasma macroenvironment. Serum proteomic pattern diagnostics is a new type of proteomic concept in which patterns of ion signatures generated from high dimensional mass spectrometry data are used as diagnostic classifiers. This recent approach has exciting potential for clinical utility of diagnostic patterns because low molecular weight metabolites, peptides, and protein fragments may have higher accuracy than traditional biomarkers of cancer detection. Intriguingly, we now have discovered that this diagnostic information exists in a bound state, complexed with circulating highly abundant carrier proteins. These diagnostic fragments may one day be harvested by circulating nanoparticles, designed to absorb, enrich, and amplify the repertoire of diagnostic biomarkers generated-even at the critical, initial stages of carcinogenesis. Copyright 2004 Elsevier Inc.

Versatile robotic interface to evaluate, enable and train locomotion and balance after neuromotor disorders.

PubMed

Dominici, Nadia; Keller, Urs; Vallery, Heike; Friedli, Lucia; van den Brand, Rubia; Starkey, Michelle L; Musienko, Pavel; Riener, Robert; Courtine, Grégoire

2012-07-01

Central nervous system (CNS) disorders distinctly impair locomotor pattern generation and balance, but technical limitations prevent independent assessment and rehabilitation of these subfunctions. Here we introduce a versatile robotic interface to evaluate, enable and train pattern generation and balance independently during natural walking behaviors in rats. In evaluation mode, the robotic interface affords detailed assessments of pattern generation and dynamic equilibrium after spinal cord injury (SCI) and stroke. In enabling mode,the robot acts as a propulsive or postural neuroprosthesis that instantly promotes unexpected locomotor capacities including overground walking after complete SCI, stair climbing following partial SCI and precise paw placement shortly after stroke. In training mode, robot-enabled rehabilitation, epidural electrical stimulation and monoamine agonists reestablish weight-supported locomotion, coordinated steering and balance in rats with a paralyzing SCI. This new robotic technology and associated concepts have broad implications for both assessing and restoring motor functions after CNS disorders, both in animals and in humans.

Simulation of an Ice Giant-style Dynamo

NASA Astrophysics Data System (ADS)

Soderlund, K. M.; Aurnou, J. M.

2010-12-01

The Ice Giants, Uranus and Neptune, are unique in the solar system. These planets are the only known bodies to have multipolar magnetic fields where the quadrupole and octopole components have strengths comparable to or greater than that of the dipole. Cloud layer observations show that the planets also have zonal (east-west) flows that are fundamentally different from the banded winds of Jupiter and Saturn. The surface winds are characterized by strong retrograde equatorial jets that are flanked on either side by prograde jets at high latitudes. Thermal emission measurements of Neptune show that the surface energy flux pattern peaks in the equatorial and polar regions with minima at mid-latitudes. (The measurements for Uranus cannot adequately resolve the emission pattern.) The winds and magnetic fields are thought to be the result of convection in the planetary interior, which will also affect the heat flux pattern. Typically, it is implicitly assumed that the zonal winds are generated in a shallow layer, separate from the dynamo generation region. However, if the magnetic fields are driven near the surface, a single region can simultaneously generate both the zonal flows and the magnetic fields. Here, we present a novel numerical model of an Ice Giant-style dynamo to investigate this possibility. An order unity convective Rossby number (ratio of buoyancy to Coriolis forces) has been chosen because retrograde equatorial jets tend to occur in spherical shells when the effects of rotation are relatively weak. Our modeling results qualitatively reproduce all of the structural features of the global dynamical observations. Thus, a self-consistent model can generate magnetic field, zonal flow, and thermal emission patterns that agree with those of Uranus and Neptune. This model, then, leads us to hypothesize that the Ice Giants' zonal flows and magnetic fields are generated via dynamically coupled deep convection processes.

Cognitive patterns: giving autonomy some context

NASA Astrophysics Data System (ADS)

Dumond, Danielle; Stacy, Webb; Geyer, Alexandra; Rousseau, Jeffrey; Therrien, Mike

2013-05-01

Today's robots require a great deal of control and supervision, and are unable to intelligently respond to unanticipated and novel situations. Interactions between an operator and even a single robot take place exclusively at a very low, detailed level, in part because no contextual information about a situation is conveyed or utilized to make the interaction more effective and less time consuming. Moreover, the robot control and sensing systems do not learn from experience and, therefore, do not become better with time or apply previous knowledge to new situations. With multi-robot teams, human operators, in addition to managing the low-level details of navigation and sensor management while operating single robots, are also required to manage inter-robot interactions. To make the most use of robots in combat environments, it will be necessary to have the capability to assign them new missions (including providing them context information), and to have them report information about the environment they encounter as they proceed with their mission. The Cognitive Patterns Knowledge Generation system (CPKG) has the ability to connect to various knowledge-based models, multiple sensors, and to a human operator. The CPKG system comprises three major internal components: Pattern Generation, Perception/Action, and Adaptation, enabling it to create situationally-relevant abstract patterns, match sensory input to a suitable abstract pattern in a multilayered top-down/bottom-up fashion similar to the mechanisms used for visual perception in the brain, and generate new abstract patterns. The CPKG allows the operator to focus on things other than the operation of the robot(s).

Applying AFM-based nanofabrication for measuring the thickness of nanopatterns: the role of head groups in the vertical self-assembly of omega-functionalized n-alkanethiols.

PubMed

Kelley, Algernon T; Ngunjiri, Johnpeter N; Serem, Wilson K; Lawrence, Steve O; Yu, Jing-Jiang; Crowe, William E; Garno, Jayne C

2010-03-02

Molecules of n-alkanethiols with methyl head groups typically form well-ordered monolayers during solution self-assembly for a wide range of experimental conditions. However, we have consistently observed that, for either carboxylic acid or thiol-terminated n-alkanethiols, under certain conditions nanografted patterns are generated with a thickness corresponding precisely to a double layer. To investigate the role of head groups for solution self-assembly, designed patterns of omega-functionalized n-alkanethiols were nanografted with systematic changes in concentration. Nanografting is an in situ approach for writing patterns of thiolated molecules on gold surfaces by scanning with an AFM tip under high force, accomplished in dilute solutions of desired ink molecules. As the tip is scanned across the surface of a self-assembled monolayer under force, the matrix molecules are displaced from the surface and are immediately replaced with fresh molecules from solution to generate nanopatterns. In this report, side-by-side comparison of nanografted patterns is achieved for different matrix molecules using AFM images. The chain length and head groups (i.e., carboxyl, hydroxyl, methyl, thiol) were varied for the nanopatterns and matrix monolayers. Interactions such as head-to-head dimerization affect the vertical self-assembly of omega-functionalized n-alkanethiol molecules within nanografted patterns. At certain threshold concentrations, double layers were observed to form when nanografting with head groups of carboxylic acid and dithiols, whereas single layers were generated exclusively for nanografted patterns with methyl and hydroxyl groups, regardless of changes in concentration.

Generation of Olympic logo with freeform lens array

NASA Astrophysics Data System (ADS)

Liu, Chengkun; Huang, Qilu; Qiu, Yishen; Chen, Weijuan; Liao, Tingdi

2017-10-01

In this paper, the Olympic rings pattern is generated by using freeform lens array and illumination light source array. Based on nonimaging optics, the freeform lens array is designed for point light source, which can generate the focused pattern of annular light spot. In order to obtain the Olympic logo pattern of five rings, the array with five freeform lenses is used. By adjusting the emission angle of each light source, the annular spot is obtained at different positions of the target plane and the Olympic rings logo is formed. We used the shading plate on the surface of the freeform lens to reduce the local light intensity so that the light spot overall irradiance distribution is more uniform. We designed a freeform lens with aperture of 26.2mm, focal length of 2000mm and the diameter of a single annual spot is 400mm. We modeled freeform lens and simulated by optical software TracePro. The ray tracing results show that the Olympic rings with uniform illumination can be obtained on the target plane with the optical efficiency up to 85.7%. At the same time, this paper also studies the effects of the target plane defocusing on the spot pattern. Simulations show that when the distance of the receiving surface to the focal plane varies within 300mm, a reasonable uniform and small distorted light spot pattern can be obtained. Compared with the traditional projection method, our method of design has the advantages of high optical efficiency, low cost and the pattern is clear and uniform.

Towards pattern generation and chaotic series prediction with photonic reservoir computers

NASA Astrophysics Data System (ADS)

Antonik, Piotr; Hermans, Michiel; Duport, François; Haelterman, Marc; Massar, Serge

2016-03-01

Reservoir Computing is a bio-inspired computing paradigm for processing time dependent signals that is particularly well suited for analog implementations. Our team has demonstrated several photonic reservoir computers with performance comparable to digital algorithms on a series of benchmark tasks such as channel equalisation and speech recognition. Recently, we showed that our opto-electronic reservoir computer could be trained online with a simple gradient descent algorithm programmed on an FPGA chip. This setup makes it in principle possible to feed the output signal back into the reservoir, and thus highly enrich the dynamics of the system. This will allow to tackle complex prediction tasks in hardware, such as pattern generation and chaotic and financial series prediction, which have so far only been studied in digital implementations. Here we report simulation results of our opto-electronic setup with an FPGA chip and output feedback applied to pattern generation and Mackey-Glass chaotic series prediction. The simulations take into account the major aspects of our experimental setup. We find that pattern generation can be easily implemented on the current setup with very good results. The Mackey-Glass series prediction task is more complex and requires a large reservoir and more elaborate training algorithm. With these adjustments promising result are obtained, and we now know what improvements are needed to match previously reported numerical results. These simulation results will serve as basis of comparison for experiments we will carry out in the coming months.

High-bandwidth generation of duobinary and alternate-mark-inversion modulation formats using SOA-based signal processing.

PubMed

Dailey, James M; Power, Mark J; Webb, Roderick P; Manning, Robert J

2011-12-19

We report on the novel all-optical generation of duobinary (DB) and alternate-mark-inversion (AMI) modulation formats at 42.6 Gb/s from an input on-off keyed signal. The modulation converter consists of two semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer gates. A detailed SOA model numerically confirms the operational principles and experimental data shows successful AMI and DB conversion at 42.6 Gb/s. We also predict that the operational bandwidth can be extended beyond 40 Gb/s by utilizing a new pattern-effect suppression scheme, and demonstrate dramatic reductions in patterning up to 160 Gb/s. We show an increasing trade-off between pattern-effect reduction and mean output power with increasing bitrate.

Prediction of Spatiotemporal Patterns of Neural Activity from Pairwise Correlations

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

Marre, O.; El Boustani, S.; Fregnac, Y.

We designed a model-based analysis to predict the occurrence of population patterns in distributed spiking activity. Using a maximum entropy principle with a Markovian assumption, we obtain a model that accounts for both spatial and temporal pairwise correlations among neurons. This model is tested on data generated with a Glauber spin-glass system and is shown to correctly predict the occurrence probabilities of spatiotemporal patterns significantly better than Ising models only based on spatial correlations. This increase of predictability was also observed on experimental data recorded in parietal cortex during slow-wave sleep. This approach can also be used to generate surrogatesmore » that reproduce the spatial and temporal correlations of a given data set.« less

Electron Beam Pattern Rotation as a Method of Tunable Bunch Train Generation

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

Halavanau, A.; Piot, P.

Transversely modulated electron beams can be formed in photo injectors via microlens array (MLA) UV laser shap- ing technique. Microlenses can be arranged in polygonal lattices, with resulting transverse electron beam modula- tion mimicking the lenses pattern. Conventionally, square MLAs are used for UV laser beam shaping, and generated electron beam patterns form square beamlet arrays. The MLA setup can be placed on a rotational mount, thereby rotating electron beam distribution. In combination with transverse-to-longitudinal emittance exchange (EEX) beam line, it allows to vary beamlets horizontal projection and tune electron bunch train. In this paper, we extend the technique tomore » the case of different MLA lattice arrangements and explore the benefits of its rotational symmetries.« less

How the Leopard Gets Its Spots.

ERIC Educational Resources Information Center

Murray, James D.

1988-01-01

Discusses a single pattern formation mechanism that could underlie the wide variety of animal coat markings found in nature. Presents the results of a mathematical model for how these patterns may be generated in the course of embryonic development. (CW)

S-SPatt: simple statistics for patterns on Markov chains.

PubMed

Nuel, Grégory

2005-07-01

S-SPatt allows the counting of patterns occurrences in text files and, assuming these texts are generated from a random Markovian source, the computation of the P-value of a given observation using a simple binomial approximation.

Generation and use of observational data patterns in the evaluation of data quality for AmeriFlux and FLUXNET

NASA Astrophysics Data System (ADS)

Pastorello, G.; Agarwal, D.; Poindexter, C.; Papale, D.; Trotta, C.; Ribeca, A.; Canfora, E.; Faybishenko, B.; Gunter, D.; Chu, H.

2015-12-01

The fluxes-measuring sites that are part of AmeriFlux are operated and maintained in a fairly independent fashion, both in terms of scientific goals and operational practices. This is also the case for most sites from other networks in FLUXNET. This independence leads to a degree of heterogeneity in the data sets collected at the sites, which is also reflected in data quality levels. The generation of derived data products and data synthesis efforts, two of the main goals of these networks, are directly affected by the heterogeneity in data quality. In a collaborative effort between AmeriFlux and ICOS, a series of quality checks are being conducted for the data sets before any network-level data processing and product generation take place. From these checks, a set of common data issues were identified, and are being cataloged and classified into data quality patterns. These patterns are now being used as a basis for implementing automation for certain data quality checks, speeding up the process of applying the checks and evaluating the data. Currently, most data checks are performed individually in each data set, requiring visual inspection and inputs from a data curator. This manual process makes it difficult to scale the quality checks, creating a bottleneck for the data processing. One goal of the automated checks is to free up time of data curators so they can focus on new or less common issues. As new issues are identified, they can also be cataloged and classified, extending the coverage of existing patterns or potentially generating new patterns, helping both improve existing automated checks and create new ones. This approach is helping make data quality evaluation faster, more systematic, and reproducible. Furthermore, these patterns are also helping with documenting common causes and solutions for data problems. This can help tower teams with diagnosing problems in data collection and processing, and also in correcting historical data sets. In this presentation, using AmeriFlux fluxes and micrometeorological data, we discuss our approach to creating observational data patterns, and how we are using them to implement new automated checks. We also detail examples of these observational data patterns, illustrating how they are being used.

Unravelling a biogeographical knot: origin of the 'leapfrog' distribution pattern of Australo-Papuan sooty owls (Strigiformes) and logrunners (Passeriformes).

PubMed Central

Norman, J A; Christidis, L; Joseph, L; Slikas, B; Alpers, D

2002-01-01

Molecular analysis of two Australo-Papuan rainforest birds exhibiting correlated 'leapfrog' patterns were used to elucidate the evolutionary origin of this unusual pattern of geographical differentiation. In both sooty owls (Tyto) and logrunners (Orthonyx), phenotypically similar populations occupy widely disjunct areas (central-eastern Australia and upland New Guinea) with a third, highly distinctive population, occurring between them in northeastern Queensland. Two mechanisms have been proposed to explain the origin of leapfrog patterns in avian distributions: recent shared ancestry of terminal populations and unequal rates or phenotypic change among populations. As the former should generate correlated patterns of phenotypic and genetic differentiation, we tested for a sister relationship between populations from New Guinea and central-eastern Australia using nuclear and mitochondrial DNA sequences. The resulting phylogenies not only refute recent ancestry as an explanation for the leapfrog pattern, but provide evidence of vastly different spatio-temporal histories for sooty owls and logrunners within the Australo-Papuan rainforests. This incongruence indicates that the evolutionary processes responsible for generating leapfrog patterns in these co-distributed taxa are complex, possibly involving a combination of selection and drift in sooty owls and convergence or retention of ancestral characteristics in logrunners. PMID:12396487

Correlation between k-space sampling pattern and MTF in compressed sensing MRSI.

PubMed

Heikal, A A; Wachowicz, K; Fallone, B G

2016-10-01

To investigate the relationship between the k-space sampling patterns used for compressed sensing MR spectroscopic imaging (CS-MRSI) and the modulation transfer function (MTF) of the metabolite maps. This relationship may allow the desired frequency content of the metabolite maps to be quantitatively tailored when designing an undersampling pattern. Simulations of a phantom were used to calculate the MTF of Nyquist sampled (NS) 32 × 32 MRSI, and four-times undersampled CS-MRSI reconstructions. The dependence of the CS-MTF on the k-space sampling pattern was evaluated for three sets of k-space sampling patterns generated using different probability distribution functions (PDFs). CS-MTFs were also evaluated for three more sets of patterns generated using a modified algorithm where the sampling ratios are constrained to adhere to PDFs. Strong visual correlation as well as high R 2 was found between the MTF of CS-MRSI and the product of the frequency-dependant sampling ratio and the NS 32 × 32 MTF. Also, PDF-constrained sampling patterns led to higher reproducibility of the CS-MTF, and stronger correlations to the above-mentioned product. The relationship established in this work provides the user with a theoretical solution for the MTF of CS MRSI that is both predictable and customizable to the user's needs.

A Multi-Scale Comparative Study of Shape and Sprawl in Metropolitan Regions of the United States

ERIC Educational Resources Information Center

Kugler, Tracy A.

2012-01-01

This dissertation constitutes a multi-scale quantitative and qualitative investigation of patterns of urban development in metropolitan regions of the United States. This work has generated a comprehensive data set on spatial patterns of metropolitan development in the U.S. and an approach to the study of such patterns that can be used to further…

Selectively Patterning Polymer Opal Films via Microimprint Lithography.

PubMed

Ding, Tao; Zhao, Qibin; Smoukov, Stoyan K; Baumberg, Jeremy J

2014-11-01

Large-scale structural color flexible coatings have been hard to create, and patterning color on them is key to many applications, including large-area strain sensors, wall-size displays, security devices, and smart fabrics. To achieve controlled tuning, a micro-imprinting technique is applied here to pattern both the surface morphology and the structural color of the polymer opal films (POFs). These POFs are made of 3D ordered arrays of hard spherical particles embedded inside soft shells. The soft outer shells cause the POFs to deform upon imprinting with a pre-patterned stamp, driving a flow of the soft polymer and a rearrangement of the hard spheres within the films. As a result, a patterned surface morphology is generated within the POFs and the structural colors are selectively modified within different regions. These changes are dependent on the pressure, temperature, and duration of imprinting, as well as the feature sizes in the stamps. Moreover, the pattern geometry and structural colors can then be further tuned by stretching. Micropattern color generation upon imprinting depends on control of colloidal transport in a polymer matrix under shear flow and brings many potential properties including stretchability and tunability, as well as being of fundamental interest.

Germline transformation of the butterfly Bicyclus anynana.

PubMed

Marcus, Jeffrey M; Ramos, Diane M; Monteiro, Antónia

2004-08-07

Ecological and evolutionary theory has frequently been inspired by the diversity of colour patterns on the wings of butterflies. More recently, these varied patterns have also become model systems for studying the evolution of developmental mechanisms. A technique that will facilitate our understanding of butterfly colour-pattern development is germline transformation. Germline transformation permits functional tests of candidate gene products and of cis-regulatory regions, and provides a means of generating new colour-pattern mutants by insertional mutagenesis. We report the successful transformation of the African satyrid butterfly Bicyclus anynana with two different transposable element vectors, Hermes and piggyBac, each carrying EGFP coding sequences driven by the 3XP3 synthetic enhancer that drives gene expression in the eyes. Candidate lines identified by screening for EGFP in adult eyes were later confirmed by PCR amplification of a fragment of the EGFP coding sequence from genomic DNA. Flanking DNA surrounding the insertions was amplified by inverse PCR and sequenced. Transformation rates were 5% for piggyBac and 10.2% for Hermes. Ultimately, the new data generated by these techniques may permit an integrated understanding of the developmental genetics of colour-pattern formation and of the ecological and evolutionary processes in which these patterns play a role.

Dynamic sensory cues shape song structure in Drosophila

NASA Astrophysics Data System (ADS)

Coen, Philip; Clemens, Jan; Weinstein, Andrew J.; Pacheco, Diego A.; Deng, Yi; Murthy, Mala

2014-03-01

The generation of acoustic communication signals is widespread across the animal kingdom, and males of many species, including Drosophilidae, produce patterned courtship songs to increase their chance of success with a female. For some animals, song structure can vary considerably from one rendition to the next; neural noise within pattern generating circuits is widely assumed to be the primary source of such variability, and statistical models that incorporate neural noise are successful at reproducing the full variation present in natural songs. In direct contrast, here we demonstrate that much of the pattern variability in Drosophila courtship song can be explained by taking into account the dynamic sensory experience of the male. In particular, using a quantitative behavioural assay combined with computational modelling, we find that males use fast modulations in visual and self-motion signals to pattern their songs, a relationship that we show is evolutionarily conserved. Using neural circuit manipulations, we also identify the pathways involved in song patterning choices and show that females are sensitive to song features. Our data not only demonstrate that Drosophila song production is not a fixed action pattern, but establish Drosophila as a valuable new model for studies of rapid decision-making under both social and naturalistic conditions.

Chimera states in networks of logistic maps with hierarchical connectivities

NASA Astrophysics Data System (ADS)

zur Bonsen, Alexander; Omelchenko, Iryna; Zakharova, Anna; Schöll, Eckehard

2018-04-01

Chimera states are complex spatiotemporal patterns consisting of coexisting domains of coherence and incoherence. We study networks of nonlocally coupled logistic maps and analyze systematically how the dilution of the network links influences the appearance of chimera patterns. The network connectivities are constructed using an iterative Cantor algorithm to generate fractal (hierarchical) connectivities. Increasing the hierarchical level of iteration, we compare the resulting spatiotemporal patterns. We demonstrate that a high clustering coefficient and symmetry of the base pattern promotes chimera states, and asymmetric connectivities result in complex nested chimera patterns.

Continuous monitoring of the lunar or Martian subsurface using on-board pattern recognition and neural processing of Rover geophysical data

NASA Technical Reports Server (NTRS)

Glass, Charles E.; Boyd, Richard V.; Sternberg, Ben K.

1991-01-01

The overall aim is to provide base technology for an automated vision system for on-board interpretation of geophysical data. During the first year's work, it was demonstrated that geophysical data can be treated as patterns and interpreted using single neural networks. Current research is developing an integrated vision system comprising neural networks, algorithmic preprocessing, and expert knowledge. This system is to be tested incrementally using synthetic geophysical patterns, laboratory generated geophysical patterns, and field geophysical patterns.

Dual CARS and SHG image acquisition scheme that combines single central fiber and multimode fiber bundle to collect and differentiate backward and forward generated photons

PubMed Central

Weng, Sheng; Chen, Xu; Xu, Xiaoyun; Wong, Kelvin K.; Wong, Stephen T. C.

2016-01-01

In coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) imaging, backward and forward generated photons exhibit different image patterns and thus capture salient intrinsic information of tissues from different perspectives. However, they are often mixed in collection using traditional image acquisition methods and thus are hard to interpret. We developed a multimodal scheme using a single central fiber and multimode fiber bundle to simultaneously collect and differentiate images formed by these two types of photons and evaluated the scheme in an endomicroscopy prototype. The ratio of these photons collected was calculated for the characterization of tissue regions with strong or weak epi-photon generation while different image patterns of these photons at different tissue depths were revealed. This scheme provides a new approach to extract and integrate information captured by backward and forward generated photons in dual CARS/SHG imaging synergistically for biomedical applications. PMID:27375938

Religious Homogamy and Marital Quality: Historical and Generational Patterns, 1980-1997

ERIC Educational Resources Information Center

Myers, Scott M.

2006-01-01

Despite significant social changes in the past 50 years, research continues to find a strong and enduring link between religious homogamy and marital quality. Yet, research has not explicitly examined whether this link has changed over time or over generations. To address historical and generational trends, I use national, longitudinal data…

Patterns of Generative Discourse in Online Discussions during the Field Experience

ERIC Educational Resources Information Center

Lafferty, Karen Elizabeth; Kopcha, Theodore J.

2016-01-01

This study examined how online discussion of the classroom challenges that preservice teachers face during the field experience can lead to problem solving and knowledge generation. Drawing upon Horn and Little's (2010) descriptions of generative discourse, the study examined how a community of preservice teachers, their university supervisors,…

RANDOM PULSE GENERATOR PRODUCING FIDUCIAL MARKS

DOEpatents

Nielsen, W.F.

1960-02-01

The apparatus for automatically applying a fiducial marking, having a nonrepetitive pattern, to a plurality of simultaneously made records comprises, in series, a bypass filter, a trigger circuit, and a pulse generator, with printing means connected to and controlled by the pulse generator for simultaneously making the visible fiducial marks on a plurality of simultaneously produced records.

Intergenerational Relationship Quality, Gender, and Grandparent Involvement

ERIC Educational Resources Information Center

Barnett, Melissa A.; Scaramella, Laura V.; Neppl, Tricia K.; Ontai, Lenna; Conger, Rand D.

2010-01-01

This prospective, intergenerational study (N = 181) considered how parent (G1, Generation 1) and child (G2, Generation 2) relationship quality during adolescence and adulthood is associated with G1's level of involvement with their 3- to 4-year-old grandchildren (G3, Generation 3). Path model analyses indicated different patterns of results for…

Sparsity-based fast CGH generation using layer-based approach for 3D point cloud model

NASA Astrophysics Data System (ADS)

Kim, Hak Gu; Jeong, Hyunwook; Ro, Yong Man

2017-03-01

Computer generated hologram (CGH) is becoming increasingly important for a 3-D display in various applications including virtual reality. In the CGH, holographic fringe patterns are generated by numerically calculating them on computer simulation systems. However, a heavy computational cost is required to calculate the complex amplitude on CGH plane for all points of 3D objects. This paper proposes a new fast CGH generation based on the sparsity of CGH for 3D point cloud model. The aim of the proposed method is to significantly reduce computational complexity while maintaining the quality of the holographic fringe patterns. To that end, we present a new layer-based approach for calculating the complex amplitude distribution on the CGH plane by using sparse FFT (sFFT). We observe the CGH of a layer of 3D objects is sparse so that dominant CGH is rapidly generated from a small set of signals by sFFT. Experimental results have shown that the proposed method is one order of magnitude faster than recently reported fast CGH generation.

Fabrication of multi-scale periodic surface structures on Ti-6Al-4V by direct laser writing and direct laser interference patterning for modified wettability applications

NASA Astrophysics Data System (ADS)

Huerta-Murillo, D.; Aguilar-Morales, A. I.; Alamri, S.; Cardoso, J. T.; Jagdheesh, R.; Lasagni, A. F.; Ocaña, J. L.

2017-11-01

In this work, hierarchical surface patterns fabricated on Ti-6Al-4V alloy combining two laser micro-machining techniques are presented. The used technologies are based on nanosecond Direct Laser Writing and picosecond Direct Laser Interference Patterning. Squared shape micro-cells with different hatch distances were produced by Direct Laser Writing with depths values in the micro-scale, forming a well-defined closed packet. Subsequently, cross-like periodic patterns were fabricated by means of Direct Laser Interference Patterning using a two-beam configuration, generating a dual-scale periodic surface structure in both micro- and nano-scale due to the formation of Laser-Induced Periodic Surface Structure after the picosecond process. As a result a triple hierarchical periodic surface structure was generated. The surface morphology of the irradiated area was characterized with scanning electron microscopy and confocal microscopy. Additionally, static contact angle measurements were made to analyze the wettability behavior of the structures, showing a hydrophobic behavior for the hierarchical structures.

A Design Principle for an Autonomous Post-translational Pattern Formation.

PubMed

Sugai, Shuhei S; Ode, Koji L; Ueda, Hiroki R

2017-04-25

Previous autonomous pattern-formation models often assumed complex molecular and cellular networks. This theoretical study, however, shows that a system composed of one substrate with multisite phosphorylation and a pair of kinase and phosphatase can generate autonomous spatial information, including complex stripe patterns. All (de-)phosphorylation reactions are described with a generic Michaelis-Menten scheme, and all species freely diffuse without pre-existing gradients. Computational simulation upon >23,000,000 randomly generated parameter sets revealed the design motifs of cyclic reaction and enzyme sequestration by slow-diffusing substrates. These motifs constitute short-range positive and long-range negative feedback loops to induce Turing instability. The width and height of spatial patterns can be controlled independently by distinct reaction-diffusion processes. Therefore, multisite reversible post-translational modification can be a ubiquitous source for various patterns without requiring other complex regulations such as autocatalytic regulation of enzymes and is applicable to molecular mechanisms for inducing subcellular localization of proteins driven by post-translational modifications. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Inkjet-Printed Biofunctional Thermo-Plasmonic Interfaces for Patterned Neuromodulation.

PubMed

Kang, Hongki; Lee, Gu-Haeng; Jung, Hyunjun; Lee, Jee Woong; Nam, Yoonkey

2018-02-27

Localized heat generation by the thermo-plasmonic effect of metal nanoparticles has great potential in biomedical engineering research. Precise patterning of the nanoparticles using inkjet printing can enable the application of the thermo-plasmonic effect in a well-controlled way (shape and intensity). However, a universally applicable inkjet printing process that allows good control in patterning and assembly of nanoparticles with good biocompatibility is missing. Here we developed inkjet-printing-based biofunctional thermo-plasmonic interfaces that can modulate biological activities. We found that inkjet printing of plasmonic nanoparticles on a polyelectrolyte layer-by-layer substrate coating enables high-quality, biocompatible thermo-plasmonic interfaces across various substrates (rigid/flexible, hydrophobic/hydrophilic) by induced contact line pinning and electrostatically assisted nanoparticle assembly. We experimentally confirmed that the generated heat from the inkjet-printed thermo-plasmonic patterns can be applied in micrometer resolution over a large area. Lastly, we demonstrated that the patterned thermo-plasmonic effect from the inkjet-printed gold nanorods can selectively modulate neuronal network activities. This inkjet printing process therefore can be a universal method for biofunctional thermo-plasmonic interfaces in various bioengineering applications.

Bio-inspired patterned networks (BIPS) for development of wearable/disposable biosensors

NASA Astrophysics Data System (ADS)

McLamore, E. S.; Convertino, M.; Hondred, John; Das, Suprem; Claussen, J. C.; Vanegas, D. C.; Gomes, C.

2016-05-01

Here we demonstrate a novel approach for fabricating point of care (POC) wearable electrochemical biosensors based on 3D patterning of bionanocomposite networks. To create Bio-Inspired Patterned network (BIPS) electrodes, we first generate fractal network in silico models that optimize transport of network fluxes according to an energy function. Network patterns are then inkjet printed onto flexible substrate using conductive graphene ink. We then deposit fractal nanometal structures onto the graphene to create a 3D nanocomposite network. Finally, we biofunctionalize the surface with biorecognition agents using covalent bonding. In this paper, BIPS are used to develop high efficiency, low cost biosensors for measuring glucose as a proof of concept. Our results on the fundamental performance of BIPS sensors show that the biomimetic nanostructures significantly enhance biosensor sensitivity, accuracy, response time, limit of detection, and hysteresis compared to conventional POC non fractal electrodes (serpentine, interdigitated, and screen printed electrodes). BIPs, in particular Apollonian patterned BIPS, represent a new generation of POC biosensors based on nanoscale and microscale fractal networks that significantly improve electrical connectivity, leading to enhanced sensor performance.

Development of signal processing algorithms for ultrasonic detection of coal seam interfaces

NASA Technical Reports Server (NTRS)

Purcell, D. D.; Ben-Bassat, M.

1976-01-01

A pattern recognition system is presented for determining the thickness of coal remaining on the roof and floor of a coal seam. The system was developed to recognize reflected pulse echo signals that are generated by an acoustical transducer and reflected from the coal seam interface. The flexibility of the system, however, should enable it to identify pulse-echo signals generated by radar or other techniques. The main difference being the specific features extracted from the recorded data as a basis for pattern recognition.

High-fidelity large area nano-patterning of silicon with femtosecond light sheet

NASA Astrophysics Data System (ADS)

Sidhu, Mehra S.; Munjal, Pooja; Singh, Kamal P.

2018-01-01

We employ a femtosecond light sheet generated by a cylindrical lens to rapidly produce high-fidelity nano-structures over large area on silicon surface. The Fourier analysis of electron microscopy images of the laser-induced surface structures reveals sharp peaks indicating good homogeneity. We observed an emergence of second-order spatial periodicity on increasing the scan speed. Our reliable approach may rapidly nano-pattern curved solid surfaces and tiny objects for diverse potential applications in optical devices, structural coloring, plasmonic substrates and in high-harmonic generation.

Predicting synchrony in heterogeneous pulse coupled oscillators

NASA Astrophysics Data System (ADS)

Talathi, Sachin S.; Hwang, Dong-Uk; Miliotis, Abraham; Carney, Paul R.; Ditto, William L.

2009-08-01

Pulse coupled oscillators (PCOs) represent an ubiquitous model for a number of physical and biological systems. Phase response curves (PRCs) provide a general mathematical framework to analyze patterns of synchrony generated within these models. A general theoretical approach to account for the nonlinear contributions from higher-order PRCs in the generation of synchronous patterns by the PCOs is still lacking. Here, by considering a prototypical example of a PCO network, i.e., two synaptically coupled neurons, we present a general theory that extends beyond the weak-coupling approximation, to account for higher-order PRC corrections in the derivation of an approximate discrete map, the stable fixed point of which can predict the domain of 1:1 phase locked synchronous states generated by the PCO network.

Differential theory of learning for efficient neural network pattern recognition

NASA Astrophysics Data System (ADS)

Hampshire, John B., II; Vijaya Kumar, Bhagavatula

1993-09-01

We describe a new theory of differential learning by which a broad family of pattern classifiers (including many well-known neural network paradigms) can learn stochastic concepts efficiently. We describe the relationship between a classifier's ability to generate well to unseen test examples and the efficiency of the strategy by which it learns. We list a series of proofs that differential learning is efficient in its information and computational resource requirements, whereas traditional probabilistic learning strategies are not. The proofs are illustrated by a simple example that lends itself to closed-form analysis. We conclude with an optical character recognition task for which three different types of differentially generated classifiers generalize significantly better than their probabilistically generated counterparts.

50 CFR 100.16 - Customary and traditional use determination process.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the community or area; (2) A pattern of use recurring in specific seasons for many years; (3) A... handing down of knowledge of fishing and hunting skills, values, and lore from generation to generation...

Controlling selective stimulations below a spinal cord hemisection using brain recordings with a neural interface system approach

NASA Astrophysics Data System (ADS)

Panetsos, Fivos; Sanchez-Jimenez, Abel; Torets, Carlos; Largo, Carla; Micera, Silvestro

2011-08-01

In this work we address the use of realtime cortical recordings for the generation of coherent, reliable and robust motor activity in spinal-lesioned animals through selective intraspinal microstimulation (ISMS). The spinal cord of adult rats was hemisectioned and groups of multielectrodes were implanted in both the central nervous system (CNS) and the spinal cord below the lesion level to establish a neural system interface (NSI). To test the reliability of this new NSI connection, highly repeatable neural responses recorded from the CNS were used as a pattern generator of an open-loop control strategy for selective ISMS of the spinal motoneurons. Our experimental procedure avoided the spontaneous non-controlled and non-repeatable neural activity that could have generated spurious ISMS and the consequent undesired muscle contractions. Combinations of complex CNS patterns generated precisely coordinated, reliable and robust motor actions.

Implementation of a data packet generator using pattern matching for wearable ECG monitoring systems.

PubMed

Noh, Yun Hong; Jeong, Do Un

2014-07-15

In this paper, a packet generator using a pattern matching algorithm for real-time abnormal heartbeat detection is proposed. The packet generator creates a very small data packet which conveys sufficient crucial information for health condition analysis. The data packet envelopes real time ECG signals and transmits them to a smartphone via Bluetooth. An Android application was developed specifically to decode the packet and extract ECG information for health condition analysis. Several graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent.

Statistical spatial properties of speckle patterns generated by multiple laser beams

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

Le Cain, A.; Sajer, J. M.; Riazuelo, G.

2011-08-15

This paper investigates hot spot characteristics generated by the superposition of multiple laser beams. First, properties of speckle statistics are studied in the context of only one laser beam by computing the autocorrelation function. The case of multiple laser beams is then considered. In certain conditions, it is shown that speckles have an ellipsoidal shape. Analytical expressions of hot spot radii generated by multiple laser beams are derived and compared to numerical estimates made from the autocorrelation function. They are also compared to numerical simulations performed within the paraxial approximation. Excellent agreement is found for the speckle width as wellmore » as for the speckle length. Application to the speckle patterns generated in the Laser MegaJoule configuration in the zone where all the beams overlap is presented. Influence of polarization on the size of the speckles as well as on their abundance is studied.« less

[Alcohol- and substance abuse among mentally ill patients with migration background in Austria].

PubMed

Stompe, Thomas; Ritter, Kristina; Holzer, David; Topitz, Andrea; Wenzel, Thomas

2016-09-01

The refugee movements of the recent years are confronting the health care with new challenges. However, it has turned out that in Austria data on the mental health of migrants are nearly not available. Especially data on the frequency and patterns of comorbid substance abuse of migrants with mental disorders do not exist even from international studies. We analyzed data from 1819 patients (1726 first generation, 93 second generation) treated in the outpatient clinic for transcultural psychiatry and migration related disorders at the Vienna General Hospital: In first-generation migrants the cultural and religious background of the region of origin has the greatest impact on the frequency and the patterns of misused substances. In second-generation migrants the consumer habits approximate to those of the majority of the society. The primary diagnosis plays a minor role. Only patients with personality disorders exhibit higher rates of illicit substance compared with other diagnoses.

Electricity prices in a competitive environment: Marginal cost pricing of generation services and financial status of electric utilities. A preliminary analysis through 2015

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

NONE

1997-08-01

The emergence of competitive markets for electricity generation services is changing the way that electricity is and will be priced in the United States. This report presents the results of an analysis that focuses on two questions: (1) How are prices for competitive generation services likely to differ from regulated prices if competitive prices are based on marginal costs rather than regulated {open_quotes}cost-of-service{close_quotes} pricing? (2) What impacts will the competitive pricing of generation services (based on marginal costs) have on electricity consumption patterns, production costs, and the financial integrity patterns, production costs, and the financial integrity of electricity suppliers? Thismore » study is not intended to be a cost-benefit analysis of wholesale or retail competition, nor does this report include an analysis of the macroeconomic impacts of competitive electricity prices.« less

Comparison of drug utilization patterns in observational data: antiepileptic drugs in pediatric patients

PubMed Central

Bourgeois, Florence T; Olson, Karen L; Poduri, Annapurna; Mandl, Kenneth D

2015-01-01

Purpose Physicians require information on the comparative benefits and harms of medications for optimal treatment decisions. However, this type of data is limited, especially for pediatric patients. Objective Our aim was to use observational data to measure and compare medication utilization patterns in a pediatric patient population. Methods Using pharmacy claims data from a large, national-scale insurance program in the US, we identified all patients with a diagnosis of epilepsy treated with a first-generation (carabamazepine, ethosuximide, phenobarbital, phenytoin, valproate) or second-generation (carbamazepine XR, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, valproate XR, zonisamide) antiepileptic drug. Treatment periods were defined based on prescription fill dates and medication days supplied. Medication use was measured for individual antiepileptic drugs and for first-generation and second-generation drugs as groups. Results There were 2527 (54%) patients who initiated therapy with first-generation and 2139 (46%) with second-generation antiepileptics. First- and second-generation drugs had the same one-year retention rates (26% [95%CI 24–28] and 26% [95%CI 25–28], respectively). A total of 26% (95%CI 25–28) and 29% (95%CI 27–31) of patients who started on a first- or second-generation antiepileptic medication, respectively, resumed treatment with the initial drug after discontinuation. Overall, 73% (95%CI 71–74) of patients were treated with only one antiepileptic drug, with similar rates for patients started on first- and second-generation drugs (71% [95%CI 69–73] vs 74% [95%CI 72–76]). Conclusions Comparing drug utilization patterns in a pediatric population using observational data, we found similar rates of retention and therapeutic changes. These findings are consistent with available comparative data and demonstrate an approach that could be extended to other drug classes and conditions in pediatric populations to examine drug effectiveness. PMID:26070280

Comparison of Drug Utilization Patterns in Observational Data: Antiepileptic Drugs in Pediatric Patients.

PubMed

Bourgeois, Florence T; Olson, Karen L; Poduri, Annapurna; Mandl, Kenneth D

2015-10-01

Physicians require information on the comparative benefits and harms of medications for optimal treatment decisions. However, this type of data is limited, especially for pediatric patients. Our aim was to use observational data to measure and compare medication utilization patterns in a pediatric patient population. Using pharmacy claims data from a large, national-scale insurance program in the USA, we identified all patients with a diagnosis of epilepsy treated with a first-generation antiepileptic drug (carbamazepine, ethosuximide, phenobarbital, phenytoin, or valproate) or a second-generation antiepileptic drug [carbamazepine extended release (XR), gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, valproate XR, or zonisamide]. Treatment periods were defined on the basis of prescription fill dates and medication days supplied. Medication use was measured for individual antiepileptic drugs and for first-generation and second-generation drugs as groups. There were 2527 patients (54 %) who initiated therapy with first-generation antiepileptics and 2139 patients (46 %) who initiated therapy with second-generation antiepileptics. First- and second-generation drugs had the same 1-year retention rates [26 % (95 % confidence interval (CI) 24-28) and 26 % (95 % CI 25-28), respectively], and 26 % of patients (95 % CI 25-28) and 29 % of patients (95 % CI 27-31) who started on a first- or second-generation antiepileptic medication, respectively, resumed treatment with the initial drug after discontinuation. Overall, 73 % of patients (95 % CI 71-74) were treated with only one antiepileptic drug, with similar rates for patients started on first- and second-generation drugs [71 % (95 % CI 69-73) versus 74 % (95 % CI 72-76)]. Comparing drug utilization patterns in a pediatric population using observational data, we found similar rates of retention and therapeutic changes. These findings are consistent with the available comparative data and demonstrate an approach that could be extended to other drug classes and conditions in pediatric populations to examine drug effectiveness.

Persistent pattern speeds in Saturn's D ring

NASA Astrophysics Data System (ADS)

Chancia, Robert; Hedman, Matthew M.

2016-05-01

Saturn's D ring is the innermost part of Saturn's ring system. Due to its close proximity to the planet, it is sensitive to perturbing forces caused by asymmetries in Saturn's interior and magnetic field. Using high-phase-angle images obtained by the Imaging Science Subsystem (ISS) over the course of the entire Cassini mission we investigate the region between 71000-73000 km from Saturn's center. Previous studies have shown that this region contains azimuthal brightness variations generated by periodic perturbing forces with frequencies close to Saturn's rotation rate (nearly twice the local orbital period). These structures are not due to a single resonance, but instead involve a complex network of patterns drifting past one another over time. Some of these could be caused by asymmetries in Saturn's magnetosphere, which have rotation rates that have been observed to change over the course of the Cassini mission. However, some patterns may be generated by perturbations from long-lived gravitational anomalies inside the planet that move at speeds comparable to Saturn's winds. By comparing observations taken over several years we can distinguish the patterns caused by each phenomenon. We identify multiple structures with nearly constant pattern speeds that would appear to be due to persistent structures inside the planet. Strangely, the rotation rates required to produce these D ring structures are different from those responsible for generating waves in the C ring (where the local orbital rate is roughly 3/2 Saturn's rotation rate).

Design and implementation of integrated solid wastes management pattern in industrial zones, case study of Shahroud, Iran

PubMed Central

2014-01-01

Background The aim of the study was to design and implementation of integrated solid wastes management pattern in Shahroud industrial zone, evaluates the results and determine possible performance problems. This cross - sectional study was carried out for 4 years in Shahroud industrial zone and the implementation process included:1- Qualitative and quantitative analysis of all solid waste generated in the city, 2- determine the current state of solid waste management in the zone and to identify programs conducted, 3- Design and implementation of integrated solid wastes management pattern including design and implementation of training programs, laws, penalties and incentives and explain and implement programs for all factories and 4- The monitoring of the implementation process and determine the results. Results Annually, 1,728 tons of solid wastes generated in the town including 1603 tons of industrial wastes and 125 tons of municipal wastes. By implementing this pattern, the two separated systems of collection and recycling of domestic and industrial wastes was launched in this zone. Also consistent with the goals, the amount of solid wastes generated and disposed in 2009 was 51.5 and 28.6 kg per 100 million Rials production, respectively. Conclusion Results showed that implementation of pattern of separated collection, training programs, capacity building, providing technical services, completing chain of industries and strengthening the cooperation between industrial estate management and industrial units could greatly reduce the waste management problems. PMID:24423020

Neurogenesis and pattern separation: time for a divorce.

PubMed

Becker, Suzanna

2017-05-01

The generation of new neurons in the adult mammalian brain has led to numerous theories as to their functional significance. One of the most widely held views is that adult neurogenesis promotes pattern separation, a process by which overlapping patterns of neural activation are mapped to less overlapping representations. While a large body of evidence supports a role for neurogenesis in high interference memory tasks, it does not support the proposed function of neurogenesis in mediating pattern separation. Instead, the adult-generated neurons seem to generate highly overlapping and yet distinct distributed representations for similar events. One way in which these immature, highly plastic, hyperactive neurons may contribute to novel memory formation while avoiding interference is by virtue of their extremely sparse connectivity with incoming perforant path fibers. Another intriguing proposal, awaiting empirical confirmation, is that the young neurons' recruitment into memory formation is gated by a novelty/mismatch mechanism mediated by CA3 or hilar back-projections. Ongoing research into the intriguing link between neurogenesis, stress-related mood disorders, and age-related neurodegeneration may lead to promising neurogenesis-based treatments for this wide range of clinical disorders. WIREs Cogn Sci 2017, 8:e1427. doi: 10.1002/wcs.1427 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

Toward robust phase-locking in Melibe swim central pattern generator models

NASA Astrophysics Data System (ADS)

Jalil, Sajiya; Allen, Dane; Youker, Joseph; Shilnikov, Andrey

2013-12-01

Small groups of interneurons, abbreviated by CPG for central pattern generators, are arranged into neural networks to generate a variety of core bursting rhythms with specific phase-locked states, on distinct time scales, which govern vital motor behaviors in invertebrates such as chewing and swimming. These movements in lower level animals mimic motions of organs in higher animals due to evolutionarily conserved mechanisms. Hence, various neurological diseases can be linked to abnormal movement of body parts that are regulated by a malfunctioning CPG. In this paper, we, being inspired by recent experimental studies of neuronal activity patterns recorded from a swimming motion CPG of the sea slug Melibe leonina, examine a mathematical model of a 4-cell network that can plausibly and stably underlie the observed bursting rhythm. We develop a dynamical systems framework for explaining the existence and robustness of phase-locked states in activity patterns produced by the modeled CPGs. The proposed tools can be used for identifying core components for other CPG networks with reliable bursting outcomes and specific phase relationships between the interneurons. Our findings can be employed for identifying or implementing the conditions for normal and pathological functioning of basic CPGs of animals and artificially intelligent prosthetics that can regulate various movements.

Printable thermoelectric devices and conductive patterns for medical applications

NASA Astrophysics Data System (ADS)

Lee, Jungmin; Kim, Hyunjung; Chen, Linfeng; Choi, Sang H.; Varadan, Vijay K.

2012-10-01

Remote point-of-care is expected to revolutionize the modern medical practice, and many efforts have been made for the development of wireless health monitoring systems for continuously detecting the physiological signals of patients. To make the remote point-of-care generally accepted and widely used, it is necessary to develop cost-effective and durable wireless health monitoring systems. Printing technique will be helpful for the fabrication of high-quality and low-cost medical devices and systems because it allows high-resolution and high-speed fabrication, low material consumption and nano-sized patterning on both flexible and rigid substrates. Furthermore, application of thermoelectric generators can replace conventional batteries as the power sources for wireless health monitoring systems because thermoelectric generators can convert the wasted heat or the heat from nature into electricity which is required for the operation of the wireless health monitoring systems. In this research, we propose the concept of printable thermoelectric devices and conductive patterns for the realization of more portable and cost-effective medical devices. To print thermoelectric generators and conductive patterns on substrates, printing inks with special characteristics should be developed. For the development of thermoelectric inks, nano-structured thermoelectric materials are synthesized and characterized; and for the development of conductive inks, two kinds of surface treated carbon nanotubes are used as active materials.

Birth-cohort patterns in Crohn's disease and ulcerative colitis.

PubMed

Sonnenberg, Amnon

2014-01-01

To test the long-term time trends of mortality from inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), for the presence of birth-cohort phenomena. We analyzed mortality data from the national statistical offices of Canada, England and Wales, Italy, the Netherlands, Switzerland, and the USA for the past 60-80 years. Age-specific rates of death were plotted against the period of death, as period-age contours, and against the period of birth, as cohort-age contours. In all six countries alike, the general time trends of IBD have been shaped by an underlying birth-cohort pattern. This pattern was also observed in the data of CD and UC analyzed separately. UC mortality increased in all generations born during the 19th century. It peaked among generations born shortly before the turn of the century and then decreased in all subsequent generations born throughout the 20th century. Compared with UC, the birth-cohort pattern of CD was delayed by 30-50 years. In addition to one risk factor responsible for the general occurrence of IBD and possibly UC alone, there exists at least one additional risk factor responsible for CD. Exposure to both separate risk factors must occur during early life.

Design of pseudorandom binary sequence generator using lithium-niobate-based Mach-Zehnder interferometers

NASA Astrophysics Data System (ADS)

Choudhary, Kuldeep; Kumar, Santosh

2017-05-01

The application of electro-optic effect in lithium-niobate-based Mach-Zehnder interferometer to design a 3-bit optical pseudorandom binary sequence (PRBS) generator has been proposed, which is characterized by its simplicity of generation and stability. The proposed device is optoelectronic in nature. The PBRS generator is immensely applicable for pattern generation, encryption, and coding applications in optical networks. The study is carried out by simulating the proposed device with beam propagation method.

A Social-Cognitive Approach to Motivation and Personality.

ERIC Educational Resources Information Center

Dweck, Carol S.; Leggett, Ellen L.

1988-01-01

A research-based model is presented that accounts for major patterns of adaptive and maladaptive behavior in terms of underlying psychological processes. It is postulated that as individuals' self-attributes are translated into allied goals, these goals generate corresponding behavior patterns. (SLD)

Intertidal habitat utilization patterns of birds in a Northeast Pacific estuary

EPA Science Inventory

A habitat-based framework is a practical method for developing models (or, ecological production functions, EPFs) to describe the spatial distribution of ecosystem services. To generate EPFs for Yaquina estuary, Oregon, USA, we compared bird use patterns among intertidal habitats...

FAST TRACK COMMUNICATION: Effects of Penning ionization on the discharge patterns of atmospheric pressure plasma jets

NASA Astrophysics Data System (ADS)

Li, Qing; Zhu, Wen-Chao; Zhu, Xi-Ming; Pu, Yi-Kang

2010-09-01

Atmospheric pressure plasma jets, generated in a coaxial dielectric barrier discharge configuration, have been investigated with different flowing gases. Discharge patterns in different tube regions were compared in the flowing gases of helium, neon and krypton. To explain the difference of these discharge patterns, a theoretical analysis is presented to reveal the possible basic processes. A comparison of experimental and theoretical results identifies that Penning ionization is mainly responsible for the discharge patterns of helium and neon plasma jets.

Electro-Optic Properties of Holographically Patterned, Polymer Stabilized Cholesteric Liquid Crystals (Preprint)

DTIC Science & Technology

2007-01-01

Electro - optic properties of cholesteric liquid crystals with holographically patterned polymer stabilization were examined. It is hypothesized that...enhanced electro - optic properties of the final device. Prior to holographic patterning, polymer stabilization with large elastic memory was generated by way... electro - optic properties appear to stem from a single dimension domain size increase, which allows for a reduction in the LC/polymer interaction.

Efficiency and Equity in the Time Pattern of Teacher Pension Benefits: An Analysis of Four State Systems. Working Paper 2007-01

ERIC Educational Resources Information Center

Costrell, Robert M.; Podgursky, Michael J.

2007-01-01

Defined Benefit pension plans often generate odd time patterns of benefits. One typical pattern exhibits low accrual in early years, accelerating in mid-late years, followed by dramatic decline, or even negative returns in years that are relatively young for retirement. We consider four states for specific analysis: Arkansas, Missouri, California…

Measurement of in-plane displacements using the phase singularities generated by directional wavelet transforms of speckle pattern images.

PubMed

Vadnjal, Ana Laura; Etchepareborda, Pablo; Federico, Alejandro; Kaufmann, Guillermo H

2013-03-20

We present a method to determine micro and nano in-plane displacements based on the phase singularities generated by application of directional wavelet transforms to speckle pattern images. The spatial distribution of the obtained phase singularities by the wavelet transform configures a network, which is characterized by two quasi-orthogonal directions. The displacement value is determined by identifying the intersection points of the network before and after the displacement produced by the tested object. The performance of this method is evaluated using simulated speckle patterns and experimental data. The proposed approach is compared with the optical vortex metrology and digital image correlation methods in terms of performance and noise robustness, and the advantages and limitations associated to each method are also discussed.

Generation mechanisms of fundamental rogue wave spatial-temporal structure.

PubMed

Ling, Liming; Zhao, Li-Chen; Yang, Zhan-Ying; Guo, Boling

2017-08-01

We discuss the generation mechanism of fundamental rogue wave structures in N-component coupled systems, based on analytical solutions of the nonlinear Schrödinger equation and modulational instability analysis. Our analysis discloses that the pattern of a fundamental rogue wave is determined by the evolution energy and growth rate of the resonant perturbation that is responsible for forming the rogue wave. This finding allows one to predict the rogue wave pattern without the need to solve the N-component coupled nonlinear Schrödinger equation. Furthermore, our results show that N-component coupled nonlinear Schrödinger systems may possess N different fundamental rogue wave patterns at most. These results can be extended to evaluate the type and number of fundamental rogue wave structure in other coupled nonlinear systems.

Studies of uncontrolled air traffic patterns, phase 1

NASA Technical Reports Server (NTRS)

Baxa, E. G., Jr.; Scharf, L. L.; Ruedger, W. H.; Modi, J. A.; Wheelock, S. L.; Davis, C. M.

1975-01-01

The general aviation air traffic flow patterns at uncontrolled airports are investigated and analyzed and traffic pattern concepts are developed to minimize the midair collision hazard in uncontrolled airspace. An analytical approach to evaluate midair collision hazard probability as a function of traffic densities is established which is basically independent of path structure. Two methods of generating space-time interrelationships between terminal area aircraft are presented; one is a deterministic model to generate pseudorandom aircraft tracks, the other is a statistical model in preliminary form. Some hazard measures are presented for selected traffic densities. It is concluded that the probability of encountering a hazard should be minimized independently of any other considerations and that the number of encounters involving visible-avoidable aircraft should be maximized at the expense of encounters in other categories.

Exploration of spatio-temporal patterns of students' movement in field trip by visualizing the log data

NASA Astrophysics Data System (ADS)

Cho, Nahye; Kang, Youngok

2018-05-01

A numerous log data in addition to user input data are being generated as mobile and web users continue to increase recently, and the studies in order to explore the patterns and meanings of various movement activities by making use of these log data are also rising rapidly. On the other hand, in the field of education, people have recognized the importance of field trip as the creative education is highlighted. Also, the examples which utilize the mobile devices in the field trip in accordance to the development of information technology are growing. In this study, we try to explore the patterns of student's activity by visualizing the log data generated from high school students' field trip with mobile device.

Neuropeptide modulation of pattern-generating systems in crustaceans: comparative studies and approaches.

PubMed

Dickinson, Patsy S; Qu, Xuan; Stanhope, Meredith E

2016-12-01

Central pattern generators are subject to modulation by peptides, allowing for flexibility in patterned output. Current techniques used to characterize peptides include mass spectrometry and transcriptomics. In recent years, hundreds of neuropeptides have been sequenced from crustaceans; mass spectrometry has been used to identify peptides and to determine their levels and locations, setting the stage for comparative studies investigating the physiological roles of peptides. Such studies suggest that there is some evolutionary conservation of function, but also divergence of function even within a species. With current baseline data, it should be possible to begin using comparative approaches to ask fundamental questions about why peptides are encoded the way that they are and how this affects nervous system function. Copyright © 2016 Elsevier Ltd. All rights reserved.

Socio-demographic differences in acculturation and mental health for a sample of 2nd generation/early immigrant Arab Americans.

PubMed

Amer, Mona M; Hovey, Joseph D

2007-10-01

This study examined socio-demographic differences in acculturation patterns among early immigrant and second-generation Arab Americans, using data from 120 participants who completed a Web-based study. Although sex, age, education, and income did not significantly relate to the acculturation process, respondents who were female and those who were married reported greater Arab ethnic identity and religiosity. Striking differences were found based on religious affiliation. Christian patterns of acculturation and mental health were consistent with acculturation theory. For Muslims, however, integration was not associated with better mental health, and religiosity was predictive of better family functioning and less depression. The results of this study suggest unique acculturation patterns for Christian and Muslim subgroups that can better inform future research and mental health service.

Generation of Crystal-Structure Transverse Patterns via a Self-Frequency-Doubling Laser

PubMed Central

Yu, Haohai; Zhang, Huaijin; Wang, Yicheng; Wang, Zhengping; Wang, Jiyang; Petrov, V.

2013-01-01

Two-dimensional (2D) visible crystal-structure patterns analogous to the quantum harmonic oscillator (QHO) have been experimentally observed in the near- and far-fields of a self-frequency-doubling (SFD) microchip laser. Different with the fundamental modes, the localization of the SFD light is changed with the propagation. Calculation based on Hermite-Gaussian (HG) functions and second harmonic generation theory reproduces well the patterns both in the near- and far-field which correspond to the intensity distribution in coordinate and momentum spaces, respectively. Considering the analogy of wave functions of the transverse HG mode and 2D harmonic oscillator, we propose that the simple monolithic SFD lasers can be used for developing of new materials and devices and testing 2D quantum mechanical theories. PMID:23336067

Generation of crystal-structure transverse patterns via a self-frequency-doubling laser.

PubMed

Yu, Haohai; Zhang, Huaijin; Wang, Yicheng; Wang, Zhengping; Wang, Jiyang; Petrov, V

2013-01-01

Two-dimensional (2D) visible crystal-structure patterns analogous to the quantum harmonic oscillator (QHO) have been experimentally observed in the near- and far-fields of a self-frequency-doubling (SFD) microchip laser. Different with the fundamental modes, the localization of the SFD light is changed with the propagation. Calculation based on Hermite-Gaussian (HG) functions and second harmonic generation theory reproduces well the patterns both in the near- and far-field which correspond to the intensity distribution in coordinate and momentum spaces, respectively. Considering the analogy of wave functions of the transverse HG mode and 2D harmonic oscillator, we propose that the simple monolithic SFD lasers can be used for developing of new materials and devices and testing 2D quantum mechanical theories.

Super-resolution photoacoustic microscopy using joint sparsity

NASA Astrophysics Data System (ADS)

Burgholzer, P.; Haltmeier, M.; Berer, T.; Leiss-Holzinger, E.; Murray, T. W.

2017-07-01

We present an imaging method that uses the random optical speckle patterns that naturally emerge as light propagates through strongly scattering media as a structured illumination source for photoacoustic imaging. Our approach, termed blind structured illumination photoacoustic microscopy (BSIPAM), was inspired by recent work in fluorescence microscopy where super-resolution imaging was demonstrated using multiple unknown speckle illumination patterns. We extend this concept to the multiple scattering domain using photoacoustics (PA), with the speckle pattern serving to generate ultrasound. The optical speckle pattern that emerges as light propagates through diffuse media provides structured illumination to an object placed behind a scattering wall. The photoacoustic signal produced by such illumination is detected using a focused ultrasound transducer. We demonstrate through both simulation and experiment, that by acquiring multiple photoacoustic images, each produced by a different random and unknown speckle pattern, an image of an absorbing object can be reconstructed with a spatial resolution far exceeding that of the ultrasound transducer. We experimentally and numerically demonstrate a gain in resolution of more than a factor of two by using multiple speckle illuminations. The variations in the photoacoustic signals generated with random speckle patterns are utilized in BSIPAM using a novel reconstruction algorithm. Exploiting joint sparsity, this algorithm is capable of reconstructing the absorbing structure from measured PA signals with a resolution close to the speckle size. Another way to excite random excitation for photoacoustic imaging are small absorbing particles, including contrast agents, which flow through small vessels. For such a set-up, the joint-sparsity is generated by the fact that all the particles move in the same vessels. Structured illumination in that case is not necessary.

SU-F-T-479: Estimation of the Accuracy in Respiratory-Gated Radiotherapy

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

Kurosawa, T; Miyakawa, S; Sato, M

Purpose: Irregular respiratory patterns affects dose outputs in respiratorygated radiotherapy and there is no commercially available quality assurance (QA) system for it. We designed and developed a patient specific QA system for respiratory-gated radiotherapy to estimate irradiated output. Methods: Our in-house QA system for gating was composed of a personal computer with the USB-FSIO electronic circuit connecting to the linear accelerator (ONCOR-K, Toshiba Medical Systems). The linac implements a respiratory gating system (AZ-733V, Anzai Medical). During the beam was on, 4.2 V square-wave pulses were continually sent to the system. Our system can receive and count the pulses. At first,more » our system and an oscilloscope were compared to check the performance of our system. Next, basic estimation models were generated when ionization-chamber measurements were performed in gating using regular sinusoidal wave patterns (2.0, 2.5, 4.0, 8.0, 15 sec/cycle). During gated irradiation with the regular patterns, the number of the pulses per one gating window was measured using our system. Correlation between the number of the pulses per one gating and dose per the gating window were assessed to generate the estimation model. Finally, two irregular respiratory patterns were created and the accuracy of the estimation was evaluated. Results: Compared to the oscilloscope, our system worked similarly. The basic models were generated with the accuracy within 0.1%. The results of the gated irradiations with two irregular respiratory patterns show good agreement within 0.4% estimation accuracy. Conclusion: Our developed system shows good estimation for even irregular respiration patterns. The system would be a useful tool to verify the output for respiratory-gated radiotherapy.« less

Establishment of spatial pattern.

PubMed

Slack, Jonathan

2014-01-01

An overview and perspective are presented of mechanisms for the development of spatial pattern in animal embryos. It is intended both for new entrants to developmental biology and for specialists in other fields, with only a basic knowledge of animal life cycles being required. The first event of pattern formation is normally the localization of a cytoplasmic determinant in the egg, either during oogenesis or post-fertilization. Following cleavage to a multicellular stage, some cells contain the determinant and others do not. The determinant confers a specific developmental pathway on the cells that contain it, often making them the source of the first extracellular signal, or inducing factor. Inducing factors often form concentration gradients to which cells respond by up or downregulating genes at various concentration thresholds. This enables an initial situation consisting of two cell states (with or without the determinant) to generate a multistate pattern. Multiple rounds of gradient signaling, interspersed with phases of morphogenetic movements, can generate a complex pattern using a small number of signals and responding genes. Development proceeds in a hierarchical manner, with broad body subdivisions being specified initially, and becoming successively subdivided to give individual organs and tissues composed of multiple cell types in a characteristic arrangement. Double gradient models can account for embryonic regulation, whereby a similarly proportioned body pattern is formed following removal of material. Processes that are involved at the later stages include the formation of repeating structures by the combination of an oscillator with a gradient, and the formation of tissues with one cell type scattered in a background of another through a process called lateral inhibition. This set of processes make up a 'developmental toolkit' which can be deployed in various sequences and combinations to generate a very wide variety of structures and cell types. © 2014 Wiley Periodicals, Inc.

Narrowing the Gap between Theory and Practice: Proposals for a Fifth Generation of Community Colleges.

ERIC Educational Resources Information Center

Deegan, William L.; Tillery, Dale

1986-01-01

The "fifth generation" of community colleges must assess and resolve fundamental questions of quality and productivity. A research agenda is outlined that addresses mission, delivery systems, student needs, and attendance patterns. (LB)

A 3D stand generator for central Appalachian hardwood forests

Treesearch

Jingxin Wang; Yaoxiang Li; Gary W. Miller

2002-01-01

A 3-dimensional (3D) stand generator was developed for central Appalachian hardwood forests. It was designed for a harvesting simulator to examine the interactions of stand, harvest, and machine. The Component Object Model (COM) was used to design and implement the program. Input to the generator includes species composition, stand density, and spatial pattern. Output...

The role of ferroelectric domain structure in second harmonic generation in random quadratic media.

PubMed

Roppo, Vito; Wang, W; Kalinowski, K; Kong, Y; Cojocaru, C; Trull, J; Vilaseca, R; Scalora, M; Krolikowski, W; Kivshar, Yu

2010-03-01

We study theoretically and numerically the second harmonic generation in a nonlinear crystal with random distribution of ferroelectric domains. We show that the specific features of disordered domain structure greatly affect the emission pattern of the generated harmonics. This phenomena can be used to characterize the degree of disorder in nonlinear photonic structures.

Learning through the Ages? Generational Inequalities and Inter-Generational Dynamics of Lifelong Learning

ERIC Educational Resources Information Center

Field, John

2013-01-01

This exploratory paper considers the concept of generation in the context of learning across the life course. Although researchers have often found considerable inequalities in participation by age, as well as strongly articulated attitudinal differences, there have so far been only a handful of studies that have explored these patterns through…

The Digital Natives as Learners: Technology Use Patterns and Approaches to Learning

ERIC Educational Resources Information Center

Thompson, Penny

2013-01-01

This study investigated the claims made in the popular press about the "digital native" generation as learners. Because students' lives today are saturated with digital media at a time when their brains are still developing, many popular press authors claim that this generation of students thinks and learns differently than any generation that has…

First-Generation and Continuing-Generation College Students: A Comparison of High School and Postsecondary Experiences. Stats in Brief. NCES 2018-009

ERIC Educational Resources Information Center

Redford, Jeremy; Hoyer, Kathleen Mulvaney

2017-01-01

This Statistics in Brief examines background and educational characteristics, plans for college, postsecondary enrollment, and postsecondary completion patterns of first-generation college students and their peers whose parents have college degrees. The brief also explores how postsecondary plans, attendance, and completion varies between these…

Mixed Methods Case Study of Generational Patterns in Responses to Shame and Guilt

ERIC Educational Resources Information Center

Ng, Tony

2013-01-01

Moral socialization and moral learning are antecedents of moral motivation. As many as 4 generations interact in workplace and education settings; hence, a deeper understanding of the moral motivation of members of those generations is needed. The purpose of this convergent mixed methods case study was to understand the moral motivation of 5…

Layout pattern analysis using the Voronoi diagram of line segments

NASA Astrophysics Data System (ADS)

Dey, Sandeep Kumar; Cheilaris, Panagiotis; Gabrani, Maria; Papadopoulou, Evanthia

2016-01-01

Early identification of problematic patterns in very large scale integration (VLSI) designs is of great value as the lithographic simulation tools face significant timing challenges. To reduce the processing time, such a tool selects only a fraction of possible patterns which have a probable area of failure, with the risk of missing some problematic patterns. We introduce a fast method to automatically extract patterns based on their structure and context, using the Voronoi diagram of line-segments as derived from the edges of VLSI design shapes. Designers put line segments around the problematic locations in patterns called "gauges," along which the critical distance is measured. The gauge center is the midpoint of a gauge. We first use the Voronoi diagram of VLSI shapes to identify possible problematic locations, represented as gauge centers. Then we use the derived locations to extract windows containing the problematic patterns from the design layout. The problematic locations are prioritized by the shape and proximity information of the design polygons. We perform experiments for pattern selection in a portion of a 22-nm random logic design layout. The design layout had 38,584 design polygons (consisting of 199,946 line segments) on layer Mx, and 7079 markers generated by an optical rule checker (ORC) tool. The optical rules specify requirements for printing circuits with minimum dimension. Markers are the locations of some optical rule violations in the layout. We verify our approach by comparing the coverage of our extracted patterns to the ORC-generated markers. We further derive a similarity measure between patterns and between layouts. The similarity measure helps to identify a set of representative gauges that reduces the number of patterns for analysis.

[Central Pattern Generators: Mechanisms of the Activity and Their Role in the Control of "Automatic" Movements].

PubMed

Arshavsky, I; Deliagina, T G; Orlovsky, G N

2015-01-01

Central pattern generators (CPGs) are a set of interconnected neurons capable of generating a basic pattern of motor output underlying "automatic" movements (breathing, locomotion, chewing, swallowing, and so on) in the absence of afferent signals from the executive motor apparatus. They can be divided into the constitutive CPGs active throughout the entire lifetime (respiratory CPGs) and conditional CPGs controlling episodic movements (locomotion, chewing, swallowing, and others). Since a motor output of CPGs is determined by their internal organization, the activities of the conditional CPGs are initiated by simple commands coming from higher centers. We describe the structural and functional organization of the locomotor CPGs in the marine mollusk Clione limacina, lamprey, frog embryo, and laboratory mammals (cat, mouse, and rat), CPGs controlling the respiratory and swallowing movements in mammals, and CPGs controlling discharges of the electric organ in the gymnotiform fish. It is shown that in all these cases, the generation of rhythmic motor output is based both on the endogenous (pacemaker) activity of specific groups of interneurons and on interneural interactions. These two interrelated mechanisms complement each other, ensuring the high reliability of CPG functionality. We discuss how the experience obtained in studying CPGs can be used to understand mechanisms of more complex functions of the brain, including its cognitive functions.

Generation, absorption, and transfer of mechanical energy during walking in children.

PubMed

Umberger, Brian R; Augsburger, Sam; Resig, JoAnne; Oeffinger, Donna; Shapiro, Robert; Tylkowski, Chester

2013-05-01

The purpose of this study was to characterize the manner in which net joint moments and non-muscular forces generate, absorb, and transfer mechanical energy during walking in able-bodied children. Standard gait data from seven healthy subjects between 6 and 17 years of age were combined with a dynamic model of the whole body to perform a power analysis based on induced acceleration techniques. These data were used to determine how each moment and force generates energy to, absorbs energy from, and transfers energy among the major body segments. The joint moments were found to induce transfers of mechanical energy between body segments that generally exceeded the magnitudes of energy generation and absorption. The amount of energy transferred by gravitational and velocity-dependent forces was considerably less than for the joint moments. The hip and ankle joint moments had relatively simple power patterns that tended to oppose each other, particularly over the stance phase. The knee joint moment had a more complex power pattern that appeared distinct from the hip and ankle moments. The general patterns of mechanical energy flow were similar to previous reports in adults. The approach described in this paper should provide a useful complement to standard clinical gait analysis procedures. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

SAR Reduction in 7T C-Spine Imaging Using a “Dark Modes” Transmit Array Strategy

PubMed Central

Eryaman, Yigitcan; Guerin, Bastien; Keil, Boris; Mareyam, Azma; Herraiz, Joaquin L.; Kosior, Robert K.; Martin, Adrian; Torrado-Carvajal, Angel; Malpica, Norberto; Hernandez-Tamames, Juan A.; Schiavi, Emanuele; Adalsteinsson, Elfar; Wald, Lawrence L.

2016-01-01

Purpose Local specific absorption rate (SAR) limits many applications of parallel transmit (pTx) in ultra high-field imaging. In this Note, we introduce the use of an array element, which is intentionally inefficient at generating spin excitation (a “dark mode”) to attempt a partial cancellation of the electric field from those elements that do generate excitation. We show that adding dipole elements oriented orthogonal to their conventional orientation to a linear array of conventional loop elements can lower the local SAR hotspot in a C-spine array at 7 T. Methods We model electromagnetic fields in a head/torso model to calculate SAR and excitation B1+ patterns generated by conventional loop arrays and loop arrays with added electric dipole elements. We utilize the dark modes that are generated by the intentional and inefficient orientation of dipole elements in order to reduce peak 10g local SAR while maintaining excitation fidelity. Results For B1+ shimming in the spine, the addition of dipole elements did not significantly alter the B1+ spatial pattern but reduced local SAR by 36%. Conclusion The dipole elements provide a sufficiently complimentary B1+ and electric field pattern to the loop array that can be exploited by the radiofrequency shimming algorithm to reduce local SAR. PMID:24753012

Threshold matrix for digital halftoning by genetic algorithm optimization

NASA Astrophysics Data System (ADS)

Alander, Jarmo T.; Mantere, Timo J.; Pyylampi, Tero

1998-10-01

Digital halftoning is used both in low and high resolution high quality printing technologies. Our method is designed to be mainly used for low resolution ink jet marking machines to produce both gray tone and color images. The main problem with digital halftoning is pink noise caused by the human eye's visual transfer function. To compensate for this the random dot patterns used are optimized to contain more blue than pink noise. Several such dot pattern generator threshold matrices have been created automatically by using genetic algorithm optimization, a non-deterministic global optimization method imitating natural evolution and genetics. A hybrid of genetic algorithm with a search method based on local backtracking was developed together with several fitness functions evaluating dot patterns for rectangular grids. By modifying the fitness function, a family of dot generators results, each with its particular statistical features. Several versions of genetic algorithms, backtracking and fitness functions were tested to find a reasonable combination. The generated threshold matrices have been tested by simulating a set of test images using the Khoros image processing system. Even though the work was focused on developing low resolution marking technology, the resulting family of dot generators can be applied also in other halftoning application areas including high resolution printing technology.

Removal of spike frequency adaptation via neuromodulation intrinsic to the Tritonia escape swim central pattern generator.

PubMed

Katz, P S; Frost, W N

1997-10-15

For the mollusc Tritonia diomedea to generate its escape swim motor pattern, interneuron C2, a crucial member of the central pattern generator (CPG) for this rhythmic behavior, must fire repetitive bursts of action potentials. Yet, before swimming, repeated depolarizing current pulses injected into C2 at periods similar those in the swim motor program are incapable of mimicking the firing rate attained by C2 on each cycle of a swim motor program. This resting level of C2 inexcitability is attributable to its own inherent spike frequency adaptation (SFA). Clearly, this property must be altered for the swim behavior to occur. The pathway for initiation of the swimming behavior involves activation of the serotonergic dorsal swim interneurons (DSIs), which are also intrinsic members of the swim CPG. Physiologically appropriate DSI stimulation transiently decreases C2 SFA, allowing C2 to fire at higher rates even when repeatedly depolarized at short intervals. The increased C2 excitability caused by DSI stimulation is mimicked and occluded by serotonin application. Furthermore, the change in excitability is not caused by the depolarization associated with DSI stimulation or serotonin application but is correlated with a decrease in C2 spike afterhyperpolarization. This suggests that the DSIs use serotonin to evoke a neuromodulatory action on a conductance in C2 that regulates its firing rate. This modulatory action of one CPG neuron on another is likely to play a role in configuring the swim circuit into its rhythmic pattern-generating mode and maintaining it in that state.

Anticonvulsant use after formulary status change for brand-name second-generation anticonvulsants.

PubMed

Patel, Hemal; Toe, Diana C; Burke, Shawn; Rasu, Rafia S

2010-08-01

Anticonvulsant medications are commonly used for off-label indications. However, managed care organizations can restrict utilization of medication to indicated uses only. To evaluate the pattern of off-label use of second-generation anticonvulsants after implementing a formulary change. We did a retrospective analysis of an administrative pharmacy claims database for a managed care plan with more than 1 million members continuously enrolled during 2004-2005. The study evaluated off-label use and explored pharmacy utilization patterns (by physician specialty, region, plan type, age, sex, copayment) across the study population following the formulary change. A total of 10,185 patients had at least 1 pharmacy claim (total of 137,638 claims) for a second-generation anticonvulsant during the study period. Most members were female (68%), and 4.9% were <18 years old. A total of 3986 of 4698 patients (84.8%) and 4600 of 5487 patients (83.8%) had anticonvulsants prescribed for off-label use in 2004 and 2005, respectively (P = .162). The off-label usage pattern varied for individual anticonvulsants in 2004 and 2005 (P <.050), which may have been because of the change to nonpreferred coverage. Primary care physicians accounted for 41.3% of the prescribing of second-generation anticonvulsants for off-label uses, followed by neurologists (9.4%), psychiatrists (2.8%), and other (46.5%). The coverage change resulted in cost savings for the plan of $0.16 per member per month. The off-label usage pattern varied for individual anticonvulsants in 2004 and 2005. Future considerations for controlling off-label use may include requiring prior authorization and provider education.

Image Correlation Pattern Optimization for Micro-Scale In-Situ Strain Measurements

NASA Technical Reports Server (NTRS)

Bomarito, G. F.; Hochhalter, J. D.; Cannon, A. H.

2016-01-01

The accuracy and precision of digital image correlation (DIC) is a function of three primary ingredients: image acquisition, image analysis, and the subject of the image. Development of the first two (i.e. image acquisition techniques and image correlation algorithms) has led to widespread use of DIC; however, fewer developments have been focused on the third ingredient. Typically, subjects of DIC images are mechanical specimens with either a natural surface pattern or a pattern applied to the surface. Research in the area of DIC patterns has primarily been aimed at identifying which surface patterns are best suited for DIC, by comparing patterns to each other. Because the easiest and most widespread methods of applying patterns have a high degree of randomness associated with them (e.g., airbrush, spray paint, particle decoration, etc.), less effort has been spent on exact construction of ideal patterns. With the development of patterning techniques such as microstamping and lithography, patterns can be applied to a specimen pixel by pixel from a patterned image. In these cases, especially because the patterns are reused many times, an optimal pattern is sought such that error introduced into DIC from the pattern is minimized. DIC consists of tracking the motion of an array of nodes from a reference image to a deformed image. Every pixel in the images has an associated intensity (grayscale) value, with discretization depending on the bit depth of the image. Because individual pixel matching by intensity value yields a non-unique scale-dependent problem, subsets around each node are used for identification. A correlation criteria is used to find the best match of a particular subset of a reference image within a deformed image. The reader is referred to references for enumerations of typical correlation criteria. As illustrated by Schreier and Sutton and Lu and Cary systematic errors can be introduced by representing the underlying deformation with under-matched shape functions. An important implication, as discussed by Sutton et al., is that in the presence of highly localized deformations (e.g., crack fronts), error can be reduced by minimizing the subset size. In other words, smaller subsets allow the more accurate resolution of localized deformations. Contrarily, the choice of optimal subset size has been widely studied and a general consensus is that larger subsets with more information content are less prone to random error. Thus, an optimal subset size balances the systematic error from under matched deformations with random error from measurement noise. The alternative approach pursued in the current work is to choose a small subset size and optimize the information content within (i.e., optimizing an applied DIC pattern), rather than finding an optimal subset size. In the literature, many pattern quality metrics have been proposed, e.g., sum of square intensity gradient (SSSIG), mean subset fluctuation, gray level co-occurrence, autocorrelation-based metrics, and speckle-based metrics. The majority of these metrics were developed to quantify the quality of common pseudo-random patterns after they have been applied, and were not created with the intent of pattern generation. As such, it is found that none of the metrics examined in this study are fit to be the objective function of a pattern generation optimization. In some cases, such as with speckle-based metrics, application to pixel by pixel patterns is ill-conditioned and requires somewhat arbitrary extensions. In other cases, such as with the SSSIG, it is shown that trivial solutions exist for the optimum of the metric which are ill-suited for DIC (such as a checkerboard pattern). In the current work, a multi-metric optimization method is proposed whereby quality is viewed as a combination of individual quality metrics. Specifically, SSSIG and two auto-correlation metrics are used which have generally competitive objectives. Thus, each metric could be viewed as a constraint imposed upon the others, thereby precluding the achievement of their trivial solutions. In this way, optimization produces a pattern which balances the benefits of multiple quality metrics. The resulting pattern, along with randomly generated patterns, is subjected to numerical deformations and analyzed with DIC software. The optimal pattern is shown to outperform randomly generated patterns.

Finding Patterns

ERIC Educational Resources Information Center

Mulvey, Bridget

2016-01-01

Students best learn science through a combination of science inquiry and language learning. This article presents a series of chemistry lessons on the naming of compounds. The weeklong unit focuses on patterns across compound names and chemical formulas and addresses several of the "Next Generation Science Standards" (NGSS Lead States…

Moving Object Detection Using a Parallax Shift Vector Algorithm

NASA Astrophysics Data System (ADS)

Gural, Peter S.; Otto, Paul R.; Tedesco, Edward F.

2018-07-01

There are various algorithms currently in use to detect asteroids from ground-based observatories, but they are generally restricted to linear or mildly curved movement of the target object across the field of view. Space-based sensors in high inclination, low Earth orbits can induce significant parallax in a collected sequence of images, especially for objects at the typical distances of asteroids in the inner solar system. This results in a highly nonlinear motion pattern of the asteroid across the sensor, which requires a more sophisticated search pattern for detection processing. Both the classical pattern matching used in ground-based asteroid search and the more sensitive matched filtering and synthetic tracking techniques, can be adapted to account for highly complex parallax motion. A new shift vector generation methodology is discussed along with its impacts on commonly used detection algorithms, processing load, and responsiveness to asteroid track reporting. The matched filter, template generator, and pattern matcher source code for the software described herein are available via GitHub.

Differential Tuning of Ventral and Dorsal Streams during the Generation of Common and Uncommon Tool Uses.

PubMed

Matheson, Heath E; Buxbaum, Laurel J; Thompson-Schill, Sharon L

2017-11-01

Our use of tools is situated in different contexts. Prior evidence suggests that diverse regions within the ventral and dorsal streams represent information supporting common tool use. However, given the flexibility of object concepts, these regions may be tuned to different types of information when generating novel or uncommon uses of tools. To investigate this, we collected fMRI data from participants who reported common or uncommon tool uses in response to visually presented familiar objects. We performed a pattern dissimilarity analysis in which we correlated cortical patterns with behavioral measures of visual, action, and category information. The results showed that evoked cortical patterns within the dorsal tool use network reflected action and visual information to a greater extent in the uncommon use group, whereas evoked neural patterns within the ventral tool use network reflected categorical information more strongly in the common use group. These results reveal the flexibility of cortical representations of tool use and the situated nature of cortical representations more generally.

Random technique to encode complex valued holograms with on axis reconstruction onto phase-only displays.

PubMed

Luis Martínez Fuentes, Jose; Moreno, Ignacio

2018-03-05

A new technique for encoding the amplitude and phase of diffracted fields in digital holography is proposed. It is based on a random spatial multiplexing of two phase-only diffractive patterns. The first one is the phase information of the intended pattern, while the second one is a diverging optical element whose purpose is the control of the amplitude. A random number determines the choice between these two diffractive patterns at each pixel, and the amplitude information of the desired field governs its discrimination threshold. This proposed technique is computationally fast and does not require iterative methods, and the complex field reconstruction appears on axis. We experimentally demonstrate this new encoding technique with holograms implemented onto a flicker-free phase-only spatial light modulator (SLM), which allows the axial generation of such holograms. The experimental verification includes the phase measurement of generated patterns with a phase-shifting polarization interferometer implemented in the same experimental setup.

Override of spontaneous respiratory pattern generator reduces cardiovascular parasympathetic influence

NASA Technical Reports Server (NTRS)

Patwardhan, A. R.; Vallurupalli, S.; Evans, J. M.; Bruce, E. N.; Knapp, C. F.

1995-01-01

We investigated the effects of voluntary control of breathing on autonomic function in cardiovascular regulation. Variability in heart rate was compared between 5 min of spontaneous and controlled breathing. During controlled breathing, for 5 min, subjects voluntarily reproduced their own spontaneous breathing pattern (both rate and volume on a breath-by-breath basis). With the use of this experimental design, we could unmask the effects of voluntary override of the spontaneous respiratory pattern generator on autonomic function in cardiovascular regulation without the confounding effects of altered respiratory pattern. Results from 10 subjects showed that during voluntary control of breathing, mean values of heart rate and blood pressure increased, whereas fractal and spectral powers in heart rate in the respiratory frequency region decreased. End-tidal PCO2 was similar during spontaneous and controlled breathing. These results indicate that the act of voluntary control of breathing decreases the influence of the vagal component, which is the principal parasympathetic influence in cardiovascular regulation.

New activity pattern in human interactive dynamics

NASA Astrophysics Data System (ADS)

Formentin, Marco; Lovison, Alberto; Maritan, Amos; Zanzotto, Giovanni

2015-09-01

We investigate the response function of human agents as demonstrated by written correspondence, uncovering a new pattern for how the reactive dynamics of individuals is distributed across the set of each agent’s contacts. In long-term empirical data on email, we find that the set of response times considered separately for the messages to each different correspondent of a given writer, generate a family of heavy-tailed distributions, which have largely the same features for all agents, and whose characteristic times grow exponentially with the rank of each correspondent. We furthermore show that this new behavioral pattern emerges robustly by considering weighted moving averages of the priority-conditioned response-time probabilities generated by a basic prioritization model. Our findings clarify how the range of priorities in the inputs from one’s environment underpin and shape the dynamics of agents embedded in a net of reactive relations. These newly revealed activity patterns might be universal, being present in other general interactive environments, and constrain future models of communication and interaction networks, affecting their architecture and evolution.

Computer driven optical keratometer and method of evaluating the shape of the cornea

NASA Technical Reports Server (NTRS)

Baroth, Edmund C. (Inventor); Mouneimme, Samih A. (Inventor)

1994-01-01

An apparatus and method for measuring the shape of the cornea utilize only one reticle to generate a pattern of rings projected onto the surface of a subject's eye. The reflected pattern is focused onto an imaging device such as a video camera and a computer compares the reflected pattern with a reference pattern stored in the computer's memory. The differences between the reflected and stored patterns are used to calculate the deformation of the cornea which may be useful for pre-and post-operative evaluation of the eye by surgeons.

Mining Temporal Patterns to Improve Agents Behavior: Two Case Studies

NASA Astrophysics Data System (ADS)

Fournier-Viger, Philippe; Nkambou, Roger; Faghihi, Usef; Nguifo, Engelbert Mephu

We propose two mechanisms for agent learning based on the idea of mining temporal patterns from agent behavior. The first one consists of extracting temporal patterns from the perceived behavior of other agents accomplishing a task, to learn the task. The second learning mechanism consists in extracting temporal patterns from an agent's own behavior. In this case, the agent then reuses patterns that brought self-satisfaction. In both cases, no assumption is made on how the observed agents' behavior is internally generated. A case study with a real application is presented to illustrate each learning mechanism.

Neural-Net Processing of Characteristic Patterns From Electronic Holograms of Vibrating Blades

NASA Technical Reports Server (NTRS)

Decker, Arthur J.

1999-01-01

Finite-element-model-trained artificial neural networks can be used to process efficiently the characteristic patterns or mode shapes from electronic holograms of vibrating blades. The models used for routine design may not yet be sufficiently accurate for this application. This document discusses the creation of characteristic patterns; compares model generated and experimental characteristic patterns; and discusses the neural networks that transform the characteristic patterns into strain or damage information. The current potential to adapt electronic holography to spin rigs, wind tunnels and engines provides an incentive to have accurate finite element models lor training neural networks.

Laser pattern generator challenges in airborne molecular contamination protection

NASA Astrophysics Data System (ADS)

Ekberg, Mats; Skotte, Per-Uno; Utterback, Tomas; Paul, Swaraj; Kishkovich, Oleg P.; Hudzik, James S.

2003-08-01

The introduction of photomask laser pattern generators presents new challenges to system designers and manufacturers. One of the laser pattern generator's environmental operating challenges is Airborne Molecular Contamination (AMC), which affects both chemically amplified resists (CAResist) and laser optics. Similar challenges in CAResist protection have already been addressed in semiconductor wafer lithography with reasonable solutions and experience gained by all those involved. However, photomask and photomask equipment manufacturers have not previously had a comparable experience, and some photomask AMC issues differ from those seen in semiconductor wafer lithography. Culminating years of AMC experience, the authors discuss specific requirements of Photomask AMC. Air sampling and material of construction analysis were performed to understand these particular AMC challenges and used to develop an appropriate filtration specification for different classes of contaminates. The authors portray the importance of cooperation between tool designers and AMC experts early in the design stage to assure goal attainment to maximize both process stability and machine productivity in advanced mask making. In conclusion, the authors provide valuable recommendations to both laser tool users and other equipment manufacturers.

Symmetry in locomotor central pattern generators and animal gaits

NASA Astrophysics Data System (ADS)

Golubitsky, Martin; Stewart, Ian; Buono, Pietro-Luciano; Collins, J. J.

1999-10-01

Animal locomotion is controlled, in part, by a central pattern generator (CPG), which is an intraspinal network of neurons capable of generating a rhythmic output. The spatio-temporal symmetries of the quadrupedal gaits walk, trot and pace lead to plausible assumptions about the symmetries of locomotor CPGs. These assumptions imply that the CPG of a quadruped should consist of eight nominally identical subcircuits, arranged in an essentially unique matter. Here we apply analogous arguments to myriapod CPGs. Analyses based on symmetry applied to these networks lead to testable predictions, including a distinction between primary and secondary gaits, the existence of a new primary gait called `jump', and the occurrence of half-integer wave numbers in myriapod gaits. For bipeds, our analysis also predicts two gaits with the out-of-phase symmetry of the walk and two gaits with the in-phase symmetry of the hop. We present data that support each of these predictions. This work suggests that symmetry can be used to infer a plausible class of CPG network architectures from observed patterns of animal gaits.

Unique identification code for medical fundus images using blood vessel pattern for tele-ophthalmology applications.

PubMed

Singh, Anushikha; Dutta, Malay Kishore; Sharma, Dilip Kumar

2016-10-01

Identification of fundus images during transmission and storage in database for tele-ophthalmology applications is an important issue in modern era. The proposed work presents a novel accurate method for generation of unique identification code for identification of fundus images for tele-ophthalmology applications and storage in databases. Unlike existing methods of steganography and watermarking, this method does not tamper the medical image as nothing is embedded in this approach and there is no loss of medical information. Strategic combination of unique blood vessel pattern and patient ID is considered for generation of unique identification code for the digital fundus images. Segmented blood vessel pattern near the optic disc is strategically combined with patient ID for generation of a unique identification code for the image. The proposed method of medical image identification is tested on the publically available DRIVE and MESSIDOR database of fundus image and results are encouraging. Experimental results indicate the uniqueness of identification code and lossless recovery of patient identity from unique identification code for integrity verification of fundus images. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Rapid in situ generation of two patterned chemoselective surface chemistries from a single hydroxy-terminated surface using controlled microfluidic oxidation.

PubMed

Pulsipher, Abigail; Westcott, Nathan P; Luo, Wei; Yousaf, Muhammad N

2009-06-10

In this work, we develop a new, rapid and inexpensive method to generate spatially controlled aldehyde and carboxylic acid surface groups by microfluidic oxidation of 11-hydroxyundecylphosphonic acid self-assembled monolayers (SAMs) on indium tin oxide (ITO) surfaces. SAMs are activated and patterned using a reversibly sealable, elastomeric polydimethylsiloxane cassette, fabricated with preformed micropatterns by soft lithography. By flowing the mild oxidant pyridinium chlorochromate through the microchannels, only selected areas of the SAM are chemically altered. This microfluidic oxidation strategy allows for ligand immobilization by two chemistries originating from a single SAM composition. ITO is robust, conductive, and transparent, making it an ideal platform for studying interfacial interactions. We display spatial control over the immobilization of a variety of ligands on ITO and characterize the resulting oxime and amide linkages by electrochemistry, X-ray photoelectron spectroscopy, contact angle, fluorescence microscopy, and atomic force microscopy. This general method may be used with many other materials to rapidly generate patterned and tailored surfaces for studies ranging from molecular electronics to biospecific cell-based assays and biomolecular microarrays.

Automatic Hidden-Web Table Interpretation by Sibling Page Comparison

NASA Astrophysics Data System (ADS)

Tao, Cui; Embley, David W.

The longstanding problem of automatic table interpretation still illudes us. Its solution would not only be an aid to table processing applications such as large volume table conversion, but would also be an aid in solving related problems such as information extraction and semi-structured data management. In this paper, we offer a conceptual modeling solution for the common special case in which so-called sibling pages are available. The sibling pages we consider are pages on the hidden web, commonly generated from underlying databases. We compare them to identify and connect nonvarying components (category labels) and varying components (data values). We tested our solution using more than 2,000 tables in source pages from three different domains—car advertisements, molecular biology, and geopolitical information. Experimental results show that the system can successfully identify sibling tables, generate structure patterns, interpret tables using the generated patterns, and automatically adjust the structure patterns, if necessary, as it processes a sequence of hidden-web pages. For these activities, the system was able to achieve an overall F-measure of 94.5%.

Microgravity

NASA Image and Video Library

2001-06-06

X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

Improved Volitional Recall of Motor-Imagery-Related Brain Activation Patterns Using Real-Time Functional MRI-Based Neurofeedback.

PubMed

Bagarinao, Epifanio; Yoshida, Akihiro; Ueno, Mika; Terabe, Kazunori; Kato, Shohei; Isoda, Haruo; Nakai, Toshiharu

2018-01-01

Motor imagery (MI), a covert cognitive process where an action is mentally simulated but not actually performed, could be used as an effective neurorehabilitation tool for motor function improvement or recovery. Recent approaches employing brain-computer/brain-machine interfaces to provide online feedback of the MI during rehabilitation training have promising rehabilitation outcomes. In this study, we examined whether participants could volitionally recall MI-related brain activation patterns when guided using neurofeedback (NF) during training. The participants' performance was compared to that without NF. We hypothesized that participants would be able to consistently generate the relevant activation pattern associated with the MI task during training with NF compared to that without NF. To assess activation consistency, we used the performance of classifiers trained to discriminate MI-related brain activation patterns. Our results showed significantly higher predictive values of MI-related activation patterns during training with NF. Additionally, this improvement in the classification performance tends to be associated with the activation of middle temporal gyrus/inferior occipital gyrus, a region associated with visual motion processing, suggesting the importance of performance monitoring during MI task training. Taken together, these findings suggest that the efficacy of MI training, in terms of generating consistent brain activation patterns relevant to the task, can be enhanced by using NF as a mechanism to enable participants to volitionally recall task-related brain activation patterns.

Image projection optical system for measuring pattern electroretinograms

NASA Astrophysics Data System (ADS)

Starkey, Douglas E.; Taboada, John; Peters, Daniel

1994-06-01

The use of the pattern-electroretinogram (PERG) as a noninvasive diagnostic tool for the early detection of glaucoma has been supported by a number of recent studies. We have developed a unique device which uses a laser interferometer to generate a sinusoidal fringe pattern that is presented to the eye in Maxwellian view for the purpose of producing a PERG response. The projection system stimulates a large visual field and is designed to bypass the optics of the eye in order to measure the true retinal response to a temporally alternating fringe pattern. The contrast, spatial frequency, total power output, orientation, alternating temporal frequency, and field location of the fringe pattern presented to the eye can all be varied by the device. It is critical for these parameters to be variable so that optimal settings may be determined for the normal state and any deviation from it, i.e. early or preclinical glaucoma. Several interferometer designs and optical projection systems were studied in order to design a compact system which provided the desired variable pattern stimulus to the eye. This paper will present a description of the clinical research instrument and its performance with the primary emphasis on the optical system design as it relates to the fringe pattern generation and other optical parameters. Examples of its use in the study of glaucoma diagnosis will also be presented.

Inferring the Structure of Social Contacts from Demographic Data in the Analysis of Infectious Diseases Spread

PubMed Central

Fumanelli, Laura; Ajelli, Marco; Manfredi, Piero; Vespignani, Alessandro; Merler, Stefano

2012-01-01

Social contact patterns among individuals encode the transmission route of infectious diseases and are a key ingredient in the realistic characterization and modeling of epidemics. Unfortunately, the gathering of high quality experimental data on contact patterns in human populations is a very difficult task even at the coarse level of mixing patterns among age groups. Here we propose an alternative route to the estimation of mixing patterns that relies on the construction of virtual populations parametrized with highly detailed census and demographic data. We present the modeling of the population of 26 European countries and the generation of the corresponding synthetic contact matrices among the population age groups. The method is validated by a detailed comparison with the matrices obtained in six European countries by the most extensive survey study on mixing patterns. The methodology presented here allows a large scale comparison of mixing patterns in Europe, highlighting general common features as well as country-specific differences. We find clear relations between epidemiologically relevant quantities (reproduction number and attack rate) and socio-demographic characteristics of the populations, such as the average age of the population and the duration of primary school cycle. This study provides a numerical approach for the generation of human mixing patterns that can be used to improve the accuracy of mathematical models in the absence of specific experimental data. PMID:23028275

Patterning of polymer nanofiber meshes by electrospinning for biomedical applications

PubMed Central

Neves, Nuno M; Campos, Rui; Pedro, Adriano; Cunha, José; Macedo, Francisco; Reis, Rui L

2007-01-01

The end-product of the electrospinning process is typically a randomly aligned fiber mesh or membrane. This is a result of the electric field generated between the drop of polymer solution at the needle and the collector. The developed electric field causes the stretching of the fibers and their random deposition. By judicious selection of the collector architecture, it is thus possible to develop other morphologies on the nanofiber meshes. The aim of this work is to prepare fiber meshes using various patterned collectors with specific dimensions and designs and to evaluate how those patterns can affect the properties of the meshes relevant to biomedical applications. This study aims at verifying whether it is possible to control the architecture of the fiber meshes by tailoring the geometry of the collector. Three different metallic collector topographies are used to test this hypothesis. Electrospun nonwoven patterned meshes of polyethylene oxide (PEO) and poly(ε-capro-lactone) (PCL) were successfully prepared. Those fiber meshes were analyzed by scanning electron microscopy (SEM). Both mechanical properties of the meshes and cell contacting experiments were performed to test the effect of the produced patterns over the properties of the meshes relevant for biomedical applications. The present study will evaluate cell adhesion sensitivity to the patterns generated and the effect of those patterns on the tensile properties of the fiber meshes. PMID:18019842

A novel method for accurate patterning and positioning of biological cells

NASA Astrophysics Data System (ADS)

Jing, Gaoshan; Labukas, Joseph P.; Iqbal, Aziz; Perry, Susan Fueshko; Ferguson, Gregory S.; Tatic-Lucic, Svetlana

2007-05-01

The ability to anchor cells in predefined patterns on a surface has become very important for the development of cell-based sensors, tissue-engineering applications, and the understanding of basic cell functions. Currently, the most widely used technique to generate micrometer or sub-micrometer-sized patterns for various biological applications is microcontact printing (μCP). However, the fidelity of the final pattern may be compromised by deformation of the PDMS stamps used during printing. A novel technique for accurately patterning and positioning biological cells is presented, which can overcome this obstacle. We have fabricated a chip on a silicon wafer using standard photolithographic and deposition processes consisting of gold patterns on top of PECVD silicon dioxide. A hydrophobic self-assembled monolayer (SAM) derived from 1-hexadecanethiol (HDT) was coated on the gold surface to prevent cell growth, and a hydrophilic SAM derived from (3-trimethoxysilyl propyl)-diethylenetriamine (DETA) was coated on the exposed PECVD silicon dioxide surface to promote cell growth. Immortalized mouse hypothalamic neurons (GT1-7) were cultured in vitro on the chip, and patterned cells were fluorescently stained and visualized by fluorescence microscopy. By our method, hydrophobic and hydrophilic regions can be reliably generated and easily visualized under a microscope prior to cell culturing. Cell growth was precisely controlled and limited to specific areas. The achieved resolution was 2 microns, and it could be improved with high resolution photolithographic methods.

Neural mechanisms of single corrective steps evoked in the standing rabbit

PubMed Central

Hsu, L.-J.; Zelenin, P. V.; Lyalka, V. F.; Vemula, M. G.; Orlovsky, G. N.; Deliagina, T. G.

2017-01-01

Single steps in different directions are often used for postural corrections. However, our knowledge about the neural mechanisms underlying their generation is scarce. This study was aimed to characterize the corrective steps generated in response to disturbances of the basic body configuration caused by forward, backward or outward displacement of the hindlimb, as well as to reveal location in the CNS of the corrective step generating mechanisms. Video recording of the motor response to translation of the supporting surface under the hindlimb along with contact forces and activity of back and limb muscles was performed in freely standing intact and in fixed postmammillary rabbits. In intact rabbits, displacement of the hindlimb in any direction caused a lateral trunk movement towards the contralateral hindlimb, and then a corrective step in the direction opposite to the initial displacement. The time difference between onsets of these two events varied considerably. The EMG pattern in the supporting hindlimb was similar for all directions of corrective steps. It caused the increase in the limb stiffness. EMG pattern in the stepping limb differed in steps with different directions. In postmammillary rabbits the corrective stepping movements, as well as EMG patterns in both stepping and standing hindlimbs were similar to those observed in intact rabbits. This study demonstrates that the corrective trunk and limb movements are generated by separate mechanisms activated by sensory signals from the deviated limb. The neuronal networks generating postural corrective steps reside in the brainstem, cerebellum, and spinal cord. PMID:28215990

Application of DNA Machineries for the Barcode Patterned Detection of Genes or Proteins.

PubMed

Zhou, Zhixin; Luo, Guofeng; Wulf, Verena; Willner, Itamar

2018-06-05

The study introduces an analytical platform for the detection of genes or aptamer-ligand complexes by nucleic acid barcode patterns generated by DNA machineries. The DNA machineries consist of nucleic acid scaffolds that include specific recognition sites for the different genes or aptamer-ligand analytes. The binding of the analytes to the scaffolds initiate, in the presence of the nucleotide mixture, a cyclic polymerization/nicking machinery that yields displaced strands of variable lengths. The electrophoretic separation of the resulting strands provides barcode patterns for the specific detection of the different analytes. Mixtures of DNA machineries that yield, upon sensing of different genes (or aptamer ligands), one-, two-, or three-band barcode patterns are described. The combination of nucleic acid scaffolds acting, in the presence of polymerase/nicking enzyme and nucleotide mixture, as DNA machineries, that generate multiband barcode patterns provide an analytical platform for the detection of an individual gene out of many possible genes. The diversity of genes (or other analytes) that can be analyzed by the DNA machineries and the barcode patterned imaging is given by the Pascal's triangle. As a proof-of-concept, the detection of one of six genes, that is, TP53, Werner syndrome, Tay-Sachs normal gene, BRCA1, Tay-Sachs mutant gene, and cystic fibrosis disorder gene by six two-band barcode patterns is demonstrated. The advantages and limitations of the detection of analytes by polymerase/nicking DNA machineries that yield barcode patterns as imaging readout signals are discussed.

Evaluation of TF11 attenuated-PSM mask blanks with DUV laser patterning

NASA Astrophysics Data System (ADS)

Xing, Kezhao; Björnberg, Charles; Karlsson, Henrik; Paulsson, Adisa; Beiming, Peter; Vedenpää, Jukka; Walford, Jonathan

2008-05-01

Tightening requirements on resolution, CD uniformity and positional accuracy push the development of improved photomask blanks. One such blank for 45nm node attenuated phase shift masks (att-PSM) provides a thinner chrome film, TF11, with a higher etch rate compared to previous generation NTAR5 att-PSM blanks from the same supplier. FEP-171, a positive chemically amplified resist, is commonly used in mask manufacturing for both e-beam and DUV laser pattern generators. TF11 chrome allows the FEP-171 resist thickness to be decreased at least down to 2000 Å while maintaining sufficient etch resistance, thereby improving photomask CD performance. The lower stress level in TF11 chrome films also reduces the image placement error induced by the material. In this study, TF11 chrome and FEP-171 resist are evaluated with exposures on a 248 nm DUV laser pattern generator, the Sigma7500. Patterning is first characterized for resist thicknesses of 2000 Å to 2600 Å in steps of 100 Å, assessing the minimum feature resolution, CD linearity, isolated-dense CD bias and dose sensitivity. Swing curve analysis shows a minimum near 2200 Å and a maximum near 2500 Å, corresponding closely to the reflectivity measurements provided by the blank supplier. The best overall patterning performance is obtained when operating near the swing maximum. The patterning performance is then studied in more detail with a resist thickness of 2550 Å that corresponds to the reflectivity maximum. This is compared to the results with 2000 Å resist, a standard thickness for e-beam exposures on TF11. The lithographic performance on NTAR5 att-PSM blanks with 3200 Å resist is also included for reference. This evaluation indicates that TF11 blanks with 2550 Å resist provide the best overall mask patterning performance obtained with the Sigma7500, showing a global CD uniformity below 4 nm (3s) and minimum feature resolution below 100 nm.

SHARAKU: an algorithm for aligning and clustering read mapping profiles of deep sequencing in non-coding RNA processing.

PubMed

Tsuchiya, Mariko; Amano, Kojiro; Abe, Masaya; Seki, Misato; Hase, Sumitaka; Sato, Kengo; Sakakibara, Yasubumi

2016-06-15

Deep sequencing of the transcripts of regulatory non-coding RNA generates footprints of post-transcriptional processes. After obtaining sequence reads, the short reads are mapped to a reference genome, and specific mapping patterns can be detected called read mapping profiles, which are distinct from random non-functional degradation patterns. These patterns reflect the maturation processes that lead to the production of shorter RNA sequences. Recent next-generation sequencing studies have revealed not only the typical maturation process of miRNAs but also the various processing mechanisms of small RNAs derived from tRNAs and snoRNAs. We developed an algorithm termed SHARAKU to align two read mapping profiles of next-generation sequencing outputs for non-coding RNAs. In contrast with previous work, SHARAKU incorporates the primary and secondary sequence structures into an alignment of read mapping profiles to allow for the detection of common processing patterns. Using a benchmark simulated dataset, SHARAKU exhibited superior performance to previous methods for correctly clustering the read mapping profiles with respect to 5'-end processing and 3'-end processing from degradation patterns and in detecting similar processing patterns in deriving the shorter RNAs. Further, using experimental data of small RNA sequencing for the common marmoset brain, SHARAKU succeeded in identifying the significant clusters of read mapping profiles for similar processing patterns of small derived RNA families expressed in the brain. The source code of our program SHARAKU is available at http://www.dna.bio.keio.ac.jp/sharaku/, and the simulated dataset used in this work is available at the same link. Accession code: The sequence data from the whole RNA transcripts in the hippocampus of the left brain used in this work is available from the DNA DataBank of Japan (DDBJ) Sequence Read Archive (DRA) under the accession number DRA004502. yasu@bio.keio.ac.jp Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

Role of Emission Character in Auger Electron Diffraction

NASA Astrophysics Data System (ADS)

Idzerda, Y. U.

A review of the interpretation of the angle-dependent Auger intensity pattern by both Auger electron diffraction (AED), which is concerned with identifying the nearby atomic structure, and angle-resolved Auger electron spectroscopy (ARAES), which is concerned with identifying the character of the emitted electron source function, is presented. The importance of the emission character of the Auger electron (in terms of its angular momentum, l, and its magnetic quantum number, m) in understanding the generation of the AED and ARAES patterns is described. Understanding of how the various direct and secondary mechanisms for the Auger electron generation can affect the populations of these states can also be used to help identify the multiplet structure within the Auger lineshape as well as elucidate the core hole generation process.

Independent Manipulation of Topological Charges and Polarization Patterns of Optical Vortices

PubMed Central

Yang, Ching-Han; Chen, Yuan-Di; Wu, Shing-Trong; Fuh, Andy Ying-Guey

2016-01-01

We present a simple and flexible method to generate various vectorial vortex beams (VVBs) with a Pancharatnam phase based on the scheme of double reflections from a single liquid crystal spatial light modulator (SLM). In this configuration, VVBs are constructed by the superposition of two orthogonally polarized orbital angular momentum (OAM) eigenstates. To verify the optical properties of the generated beams, Stokes polarimetry is developed to measure the states of polarization (SOP) over the transverse plane, while a Shack–Hartmann wavefront sensor is used to measure the OAM charge of beams. It is shown that both the simulated and the experimental results are in good qualitative agreement. In addition, polarization patterns and OAM charges of generated beams can be controlled independently using the proposed method. PMID:27526858

Near-field diffraction from amplitude diffraction gratings: theory, simulation and results

NASA Astrophysics Data System (ADS)

Abedin, Kazi Monowar; Rahman, S. M. Mujibur

2017-08-01

We describe a computer simulation method by which the complete near-field diffract pattern of an amplitude diffraction grating can be generated. The technique uses the method of iterative Fresnel integrals to calculate and generate the diffraction images. Theoretical background as well as the techniques to perform the simulation is described. The program is written in MATLAB, and can be implemented in any ordinary PC. Examples of simulated diffraction images are presented and discussed. The generated images in the far-field where they reduce to Fraunhofer diffraction pattern are also presented for a realistic grating, and compared with the results predicted by the grating equation, which is applicable in the far-field. The method can be used as a tool to teach the complex phenomenon of diffraction in classrooms.

Cryopyrin-associated periodic syndromes: development of a patient-reported outcomes instrument to assess the pattern and severity of clinical disease activity.

PubMed

Hoffman, Hal M; Wolfe, Frederick; Belomestnov, Pavel; Mellis, Scott J

2008-09-01

Development of an instrument for characterization of symptom patterns and severity in patients with cryopyrin-associated periodic syndromes (CAPS). Two generations of daily health assessment forms (DHAFs) were evaluated in this study. The first-generation DHAF queried 11 symptoms. Analyses of results obtained with that instrument identified five symptoms included in a revised second-generation DHAF that was tested for internal consistency and test-retest reliability. This DHAF was also assessed during the initial portion of a phase 3 clinical study of CAPS treatment. Forty-eight CAPS patients provided data for the first-generation DHAFs. Five symptoms (rash, fever, joint pain, eye redness/pain, and fatigue) were included in the revised second-generation DHAF. Symptom severity was highly variable during all study phases with as many as 89% of patients reporting at least one symptom flare, and percentages of days with flares reaching 58% during evaluation of the second-generation instrument. Mean composite key symptom scores (KSSs) computed during evaluation of the second-generation DHAF correlated well with Physician's Global Assessment of Disease Activity (r=0.91, p<0.0001) and patient reports of limitations of daily activities (r=0.68, p<0.0001). Test-retest reliability and Cronbach's alpha's were high (0.93 and 0.94, respectively) for the second-generation DHAF. Further evaluation of this DHAF during a baseline period and placebo treatment in a phase 3 clinical study of CAPS patients indicated strong correlations between baseline KSS and Physician's Global Assessment of Disease Activity. Cronbach's alpha's at baseline and test-retest reliability were also high. Potentially important study limitations include small sample size, the lack of a standard tool for CAPS symptom assessment against which to validate the DHAF, and no assessment of the instrument's responsivity to CAPS therapy. The DHAF is a new instrument that may be useful for capturing symptom patterns and severity in CAPS patients and monitoring responses to therapies for these conditions.

Modeling of Diffusion Based Correlations Between Heart Rate Modulations and Respiration Pattern

DTIC Science & Technology

2001-10-25

1 of 4 MODELING OF DIFFUSION BASED CORRELATIONS BETWEEN HEART RATE MODULATIONS AND RESPIRATION PATTERN R.Langer,(1) Y.Smorzik,(2) S.Akselrod,(1...generations of the bronchial tree. The second stage describes the oxygen diffusion process from the pulmonary gas in the alveoli into the pulmonary...patterns (FRC, TV, rate). Keywords – Modeling, Diffusion , Heart Rate fluctuations I. INTRODUCTION Under a whole-body management perception, the

A perturbation analysis of a mechanical model for stable spatial patterning in embryology

NASA Astrophysics Data System (ADS)

Bentil, D. E.; Murray, J. D.

1992-12-01

We investigate a mechanical cell-traction mechanism that generates stationary spatial patterns. A linear analysis highlights the model's potential for these heterogeneous solutions. We use multiple-scale perturbation techniques to study the evolution of these solutions and compare our solutions with numerical simulations of the model system. We discuss some potential biological applications among which are the formation of ridge patterns, dermatoglyphs, and wound healing.

DNA fingerprinting of isolates of Streptococcus mutans by pulsed-field gel electrophoresis.

PubMed

Mineyama, R; Yoshino, S; Maeda, N

2007-01-01

Forty isolates and five standard laboratory strains, representing serotypes c, e and f of Streptococcus mutans were analyzed by pulsed-field gel electrophoresis (PFGE) after digestion of the genomic DNA with BssH II. The digestion patterns of standard laboratory strains were characteristic of serotypes c, e and f. Serotypes c and f generated diagnostic DNA fragments of approximately 145 kbp and of approximately 130-175 kbp in length, respectively. Serotype e generated a ladder of at least 14 fragments of 15-155 kbp in length. The digestion patterns of isolates were essentially similar to those of the standard laboratory strains. The patterns of almost all isolates obtained from a single individual were identical, but patterns of a few different types were also observed among isolates obtained from two individuals. Digestion with BssH II revealed differences among isolates obtained from different individuals. We used differences in banding patterns among isolates to construct a dendrogram. The dendrogram included two major clusters, one that consisted of isolates of serotypes c and f, and an other that consisted of isolates of serotype e. Our results indicate that BssH II is a useful enzyme for distinguishing among isolates of S. mutans and that digestion patterns obtained by PFGE can be used for chromosomal DNA fingerprinting.

Imaging performance improvement of coherent extreme-ultraviolet scatterometry microscope with high-harmonic-generation extreme-ultraviolet source

NASA Astrophysics Data System (ADS)

Mamezaki, Daiki; Harada, Tetsuo; Nagata, Yutaka; Watanabe, Takeo

2017-06-01

In extreme-ultraviolet (EUV) lithography, the development of a review apparatus for the EUV mask pattern at an exposure wavelength of 13.5 nm is required. The EUV mask is composed of an absorber pattern and a Mo/Si multilayer on a glass substrate. This mask pattern has a three-dimensional (3D) structure. The 3D structure would modulate the EUV reflection phase, which would cause focus and pattern shifts. Thus, the review of the EUV phase image is also important. We have developed a coherent EUV scatterometry microscope (CSM), which is a simple microscope without objective optics. The EUV phase and intensity images were reconstructed with diffraction images by ptychography. For a standalone mask review, the high-harmonic-generation (HHG) EUV source was employed. In this study, we updated the sample stage, pump-laser reduction system, and gas-pressure control system to reconstruct the image. As a result, an 88 nm line-and-space pattern and a cross-line pattern were reconstructed. In addition, a particle defect of 2 µm diameter was well reconstructed. This demonstrated the high capability of the standalone CSM, which can hence be used in factories, such as mask shops and semiconductor fabrication plants.

Observation of EUVL mask using coherent EUV scatterometry microscope with high-harmonic-generation EUV source

NASA Astrophysics Data System (ADS)

Mamezaki, Daiki; Harada, Tetsuo; Nagata, Yutaka; Watanabe, Takeo

2017-07-01

In extreme ultraviolet (EUV) lithography, development of review tools for EUV mask pattern and phase defect at working wavelength of 13.5 nm is required. The EUV mask is composed of an absorber pattern (50 - 70 nm thick) and Mo/Si multilayer (280 nm thick) on a glass substrate. This mask pattern seems three-dimensional (3D) structure. This 3D structure would modulate EUV reflection phase, which would cause focus and pattern shifts. Thus, EUV phase imaging is important to evaluate this phase modulation. We have developed coherent EUV scatterometry microscope (CSM), which is a simple microscope without objective optics. EUV phase and intensity image are reconstructed with diffraction images by ptychography with coherent EUV illumination. The high-harmonic-generation (HHG) EUV source was employed for standalone CSM system. In this study, we updated HHG system of pump-laser reduction and gas-pressure control. Two types of EUV mask absorber patterns were observed. An 88-nm lines-and-spaces and a cross-line patterns were clearly reconstructed by ptychography. In addition, a natural defect with 2-μm diameter on the cross-line was well reconstructed. This demonstrated the high capability of the standalone CSM, which system will be used in the factories, such as mask shops and semiconductor fabrication plants.

Mining co-occurrence and sequence patterns from cancer diagnoses in New York State.

PubMed

Wang, Yu; Hou, Wei; Wang, Fusheng

2018-01-01

The goal of this study is to discover disease co-occurrence and sequence patterns from large scale cancer diagnosis histories in New York State. In particular, we want to identify disparities among different patient groups. Our study will provide essential knowledge for clinical researchers to further investigate comorbidities and disease progression for improving the management of multiple diseases. We used inpatient discharge and outpatient visit records from the New York State Statewide Planning and Research Cooperative System (SPARCS) from 2011-2015. We grouped each patient's visit history to generate diagnosis sequences for seven most popular cancer types. We performed frequent disease co-occurrence mining using the Apriori algorithm, and frequent disease sequence patterns discovery using the cSPADE algorithm. Different types of cancer demonstrated distinct patterns. Disparities of both disease co-occurrence and sequence patterns were observed from patients within different age groups. There were also considerable disparities in disease co-occurrence patterns with respect to different claim types (i.e., inpatient, outpatient, emergency department and ambulatory surgery). Disparities regarding genders were mostly found where the cancer types were gender specific. Supports of most patterns were usually higher for males than for females. Compared with secondary diagnosis codes, primary diagnosis codes can convey more stable results. Two disease sequences consisting of the same diagnoses but in different orders were usually with different supports. Our results suggest that the methods adopted can generate potentially interesting and clinically meaningful disease co-occurrence and sequence patterns, and identify disparities among various patient groups. These patterns could imply comorbidities and disease progressions.

The punctum fixum-punctum mobile model: a neuromuscular principle for efficient movement generation?

PubMed

von Laßberg, Christoph; Rapp, Walter

2015-01-01

According to the "punctum fixum-punctum mobile model" that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of context-specific key movement sequences in different disciplines of sports, as well as during non-sport specific movements.

The Punctum Fixum-Punctum Mobile Model: A Neuromuscular Principle for Efficient Movement Generation?

PubMed Central

von Laßberg, Christoph; Rapp, Walter

2015-01-01

According to the “punctum fixum–punctum mobile model” that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of context-specific key movement sequences in different disciplines of sports, as well as during non-sport specific movements. PMID:25822498

Solution Patterns Predicting Pythagorean Triples

ERIC Educational Resources Information Center

Ezenweani, Ugwunna Louis

2013-01-01

Pythagoras Theorem is an old mathematical treatise that has traversed the school curricula from secondary to tertiary levels. The patterns it produced are quite interesting that many researchers have tried to generate a kind of predictive approach to identifying triples. Two attempts, namely Diophantine equation and Brahmagupta trapezium presented…

TOOLS FOR PRESENTING SPATIAL AND TEMPORAL PATTERNS OF ENVIRONMENTAL MONITORING DATA

EPA Science Inventory

The EPA Health Effects Research Laboratory has developed this data presentation tool for use with a variety of types of data which may contain spatial and temporal patterns of interest. he technology links mainframe computing power to the new generation of "desktop publishing" ha...

Biological Systems and Career Analysis.

ERIC Educational Resources Information Center

Thiemann, Francis C.

Neither a review of the literature nor three data displays (showing career paths, general influence patterns, and predecessor and successor influence patterns) yield a generative or explanatory theory by which to understand data collected on the professional career paths of Alberta (Canada) educational administrators. The data came from a survey…

Demonstration of lithography patterns using reflective e-beam direct write

NASA Astrophysics Data System (ADS)

Freed, Regina; Sun, Jeff; Brodie, Alan; Petric, Paul; McCord, Mark; Ronse, Kurt; Haspeslagh, Luc; Vereecke, Bart

2011-04-01

Traditionally, e-beam direct write lithography has been too slow for most lithography applications. E-beam direct write lithography has been used for mask writing rather than wafer processing since the maximum blur requirements limit column beam current - which drives e-beam throughput. To print small features and a fine pitch with an e-beam tool requires a sacrifice in processing time unless one significantly increases the total number of beams on a single writing tool. Because of the uncertainty with regards to the optical lithography roadmap beyond the 22 nm technology node, the semiconductor equipment industry is in the process of designing and testing e-beam lithography tools with the potential for high volume wafer processing. For this work, we report on the development and current status of a new maskless, direct write e-beam lithography tool which has the potential for high volume lithography at and below the 22 nm technology node. A Reflective Electron Beam Lithography (REBL) tool is being developed for high throughput electron beam direct write maskless lithography. The system is targeting critical patterning steps at the 22 nm node and beyond at a capital cost equivalent to conventional lithography. Reflective Electron Beam Lithography incorporates a number of novel technologies to generate and expose lithographic patterns with a throughput and footprint comparable to current 193 nm immersion lithography systems. A patented, reflective electron optic or Digital Pattern Generator (DPG) enables the unique approach. The Digital Pattern Generator is a CMOS ASIC chip with an array of small, independently controllable lens elements (lenslets), which act as an array of electron mirrors. In this way, the REBL system is capable of generating the pattern to be written using massively parallel exposure by ~1 million beams at extremely high data rates (~ 1Tbps). A rotary stage concept using a rotating platen carrying multiple wafers optimizes the writing strategy of the DPG to achieve the capability of high throughput for sparse pattern wafer levels. The lens elements on the DPG are fabricated at IMEC (Leuven, Belgium) under IMEC's CMORE program. The CMOS fabricated DPG contains ~ 1,000,000 lens elements, allowing for 1,000,000 individually controllable beamlets. A single lens element consists of 5 electrodes, each of which can be set at controlled voltage levels to either absorb or reflect the electron beam. A system using a linear movable stage and the DPG integrated into the electron optics module was used to expose patterns on device representative wafers. Results of these exposure tests are discussed.

Advances in roll to roll processing of optics

NASA Astrophysics Data System (ADS)

Watts, Michael P. C.

2008-02-01

Today, there are a number of successful commercial applications that utilize roll to roll processing and almost all involve optics; unpatterned film, patterned film, and devices on film. The largest applications today are in holograms, and brightness enhancement film (BEF) for LCD. Solar cells are rapidly growing. These are mostly made in large captive facilities with their own proprietary equipment, materials and pattern generation capability. World wide roll to roll volume is > 100M meters2 year -1, and generates sales of > $5B. The vast majority of the sales are in BEF film by 3M.

Polarization pattern of vector vortex beams generated by q-plates with different topological charges.

PubMed

Cardano, Filippo; Karimi, Ebrahim; Slussarenko, Sergei; Marrucci, Lorenzo; de Lisio, Corrado; Santamato, Enrico

2012-04-01

We describe the polarization topology of the vector beams emerging from a patterned birefringent liquid crystal plate with a topological charge q at its center (q-plate). The polarization topological structures for different q-plates and different input polarization states have been studied experimentally by measuring the Stokes parameters point-by-point in the beam transverse plane. Furthermore, we used a tuned q=1/2-plate to generate cylindrical vector beams with radial or azimuthal polarizations, with the possibility of switching dynamically between these two cases by simply changing the linear polarization of the input beam.

Single-Chip Microcomputer Control Of The PWM Inverter

NASA Astrophysics Data System (ADS)

Morimoto, Masayuki; Sato, Shinji; Sumito, Kiyotaka; Oshitani, Katsumi

1987-10-01

A single-chip microcomputer-based con-troller for a pulsewidth modulated 1.7 KVA inverter of an airconditioner is presented. The PWM pattern generation and the system control of the airconditioner are achieved by software of the 8-bit single-chip micro-computer. The single-chip microcomputer has the disadvantages of low processing speed and small memory capacity which can be overcome by the magnetic flux control method. The PWM pattern is generated every 90 psec. The memory capacity of the PWM look-up table is less than 2 kbytes. The simple and reliable control is realized by the software-based implementation.

Three-dimensional imaging of micro-specimen by optical scanning holography

NASA Astrophysics Data System (ADS)

Liu, Jung-Ping; Tsou, Cheng-Hao

2017-04-01

Optical scanning holography (OSH) is a scanning-type digital holographic technique. In OSH, a heterodyne interference pattern is generated to raster scan the object. OSH can be operated in the incoherent mode and thus is able to record a fluorescence hologram. In addition, resolution of the OSH is proportional to the density of the interference pattern. Here we use a high-NA microscope objective to generate a dynamic Fresnel zone plate to record a hologram of micro-specimen. The achieved transverse resolution and longitudinal resolution are 0.78μm and 3.1μm, respectively.

High aspect ratio patterning of photosensitive polyimide with low thermal expansion coefficient and low dielectric constant

NASA Astrophysics Data System (ADS)

Dick, Andrew R.; Bell, William K.; Luke, Brendan; Maines, Erin; Mueller, Brennen; Rawlings, Brandon; Kohl, Paul A.; Grant Willson, C.

2016-07-01

A photosensitive polyimide system based on amine catalyzed imidization of a precursor poly(amic ester) is described. The material is based on the meta ethyl ester of pyromellitic dianhydride and 2,2' bis(trifluoromethyl)benzidine. It acts as a negative tone resist when formulated with a photobase generator. The material exhibits a dielectric constant of 3.0 in the gigahertz range, a coefficient of thermal expansion of 6±2 ppm/K, and can be patterned to aspect ratios of >2 when formulated with a highly quantum efficient cinnamide type photobase generator.

Safety Case Patterns: Theory and Applications

NASA Technical Reports Server (NTRS)

Denney, Ewen W.; Pai, Ganesh J.

2015-01-01

We develop the foundations for a theory of patterns of safety case argument structures, clarifying the concepts involved in pattern specification, including choices, labeling, and well-founded recursion. We specify six new patterns in addition to those existing in the literature. We give a generic way to specify the data required to instantiate patterns and a generic algorithm for their instantiation. This generalizes earlier work on generating argument fragments from requirements tables. We describe an implementation of these concepts in AdvoCATE, the Assurance Case Automation Toolset, showing how patterns are defined and can be instantiated. In particular, we describe how our extended notion of patterns can be specified, how they can be instantiated in an interactive manner, and, finally, how they can be automatically instantiated using our algorithm.

Language Maintenance and Language Shift among Chinese Immigrant Parents and Their Second-Generation Children in the U.S.

ERIC Educational Resources Information Center

Zhang, Donghui

2010-01-01

This study examines the language experiences of two distinct Chinese immigrant groups in the U.S.: a Mandarin-speaking group and a Fujianese-speaking group across two generations. The different language trajectories of the parents' generation, along with their social class and different settlement patterns in the U.S., shaped the second-generation…

Geometric pre-patterning based tuning of the period doubling onset strain during thin film wrinkling

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

Saha, Sourabh K.

Wrinkling of supported thin films is an easy-to-implement and low-cost fabrication technique for generation of stretch-tunable periodic micro and nano-scale structures. However, the tunability of such structures is often limited by the emergence of an undesirable period doubled mode at high strains. Predictively tuning the onset strain for period doubling via existing techniques requires one to have extensive knowledge about the nonlinear pattern formation behavior. Herein, a geometric pre-patterning based technique is introduced to delay the onset of period doubling that can be implemented to predictively tune the onset strain even with limited system knowledge. The technique comprises pre-patterning themore » film/base bilayer with a sinusoidal pattern that has the same period as the natural wrinkle period of the system. The effectiveness of this technique has been verified via physical and computational experiments on the polydimethylsiloxane/glass bilayer system. It is observed that the period doubling onset strain can be increased from the typical value of 20% for flat films to greater than 30% with a modest pre-pattern aspect ratio (2∙amplitude/period) of 0.15. In addition, finite element simulations reveal that (i) the onset strain can be increased up to a limit by increasing the amplitude of the pre-patterns and (ii) the delaying effect can be captured entirely by the pre-pattern geometry. As a result, one can implement this technique even with limited system knowledge, such as material properties or film thickness, by simply replicating pre-existing wrinkled patterns to generate prepatterned bilayers. Thus, geometric pre-patterning is a practical scheme to suppress period doubling that can increase the operating range of stretch-tunable wrinkle-based devices by at least 50%.« less

Association mining of dependency between time series

NASA Astrophysics Data System (ADS)

Hafez, Alaaeldin

2001-03-01

Time series analysis is considered as a crucial component of strategic control over a broad variety of disciplines in business, science and engineering. Time series data is a sequence of observations collected over intervals of time. Each time series describes a phenomenon as a function of time. Analysis on time series data includes discovering trends (or patterns) in a time series sequence. In the last few years, data mining has emerged and been recognized as a new technology for data analysis. Data Mining is the process of discovering potentially valuable patterns, associations, trends, sequences and dependencies in data. Data mining techniques can discover information that many traditional business analysis and statistical techniques fail to deliver. In this paper, we adapt and innovate data mining techniques to analyze time series data. By using data mining techniques, maximal frequent patterns are discovered and used in predicting future sequences or trends, where trends describe the behavior of a sequence. In order to include different types of time series (e.g. irregular and non- systematic), we consider past frequent patterns of the same time sequences (local patterns) and of other dependent time sequences (global patterns). We use the word 'dependent' instead of the word 'similar' for emphasis on real life time series where two time series sequences could be completely different (in values, shapes, etc.), but they still react to the same conditions in a dependent way. In this paper, we propose the Dependence Mining Technique that could be used in predicting time series sequences. The proposed technique consists of three phases: (a) for all time series sequences, generate their trend sequences, (b) discover maximal frequent trend patterns, generate pattern vectors (to keep information of frequent trend patterns), use trend pattern vectors to predict future time series sequences.

Spin voltage generation through optical excitation of complementary spin populations

NASA Astrophysics Data System (ADS)

Bottegoni, Federico; Celebrano, Michele; Bollani, Monica; Biagioni, Paolo; Isella, Giovanni; Ciccacci, Franco; Finazzi, Marco

2014-08-01

By exploiting the spin degree of freedom of carriers inside electronic devices, spintronics has a huge potential for quantum computation and dissipationless interconnects. Pure spin currents in spintronic devices should be driven by a spin voltage generator, able to drive the spin distribution out of equilibrium without inducing charge currents. Ideally, such a generator should operate at room temperature, be highly integrable with existing semiconductor technology, and not interfere with other spintronic building blocks that make use of ferromagnetic materials. Here we demonstrate a device that matches these requirements by realizing the spintronic equivalent of a photovoltaic generator. Whereas a photovoltaic generator spatially separates photoexcited electrons and holes, our device exploits circularly polarized light to produce two spatially well-defined electron populations with opposite in-plane spin projections. This is achieved by modulating the phase and amplitude of the light wavefronts entering a semiconductor (germanium) with a patterned metal overlayer (platinum). The resulting light diffraction pattern features a spatially modulated chirality inside the semiconductor, which locally excites spin-polarized electrons thanks to electric dipole selection rules.

Object tracking mask-based NLUT on GPUs for real-time generation of holographic videos of three-dimensional scenes.

PubMed

Kwon, M-W; Kim, S-C; Yoon, S-E; Ho, Y-S; Kim, E-S

2015-02-09

A new object tracking mask-based novel-look-up-table (OTM-NLUT) method is proposed and implemented on graphics-processing-units (GPUs) for real-time generation of holographic videos of three-dimensional (3-D) scenes. Since the proposed method is designed to be matched with software and memory structures of the GPU, the number of compute-unified-device-architecture (CUDA) kernel function calls and the computer-generated hologram (CGH) buffer size of the proposed method have been significantly reduced. It therefore results in a great increase of the computational speed of the proposed method and enables real-time generation of CGH patterns of 3-D scenes. Experimental results show that the proposed method can generate 31.1 frames of Fresnel CGH patterns with 1,920 × 1,080 pixels per second, on average, for three test 3-D video scenarios with 12,666 object points on three GPU boards of NVIDIA GTX TITAN, and confirm the feasibility of the proposed method in the practical application of electro-holographic 3-D displays.

Three-directional motion-compensation mask-based novel look-up table on graphics processing units for video-rate generation of digital holographic videos of three-dimensional scenes.

PubMed

Kwon, Min-Woo; Kim, Seung-Cheol; Kim, Eun-Soo

2016-01-20

A three-directional motion-compensation mask-based novel look-up table method is proposed and implemented on graphics processing units (GPUs) for video-rate generation of digital holographic videos of three-dimensional (3D) scenes. Since the proposed method is designed to be well matched with the software and memory structures of GPUs, the number of compute-unified-device-architecture kernel function calls can be significantly reduced. This results in a great increase of the computational speed of the proposed method, allowing video-rate generation of the computer-generated hologram (CGH) patterns of 3D scenes. Experimental results reveal that the proposed method can generate 39.8 frames of Fresnel CGH patterns with 1920×1080 pixels per second for the test 3D video scenario with 12,088 object points on dual GPU boards of NVIDIA GTX TITANs, and they confirm the feasibility of the proposed method in the practical application fields of electroholographic 3D displays.

Hybrid strategies for nanolithography and chemical patterning

NASA Astrophysics Data System (ADS)

Srinivasan, Charan

Remarkable technological advances in photolithography have extended patterning to the sub-50-nm regime. However, because photolithography is a top-down approach, it faces substantial technological and economic challenges in maintaining the downward scaling trends of feature sizes below 30 nm. Concurrently, fundamental research on chemical self-assembly has enabled the path to access molecular length scales. The key to the success of photolithography is its inherent economies of scale, which justify the large capital investment for its implementation. In this thesis research, top-down and bottom-up approaches have been combined synergistically, and these hybrid strategies have been employed in applications that do not have the economies of scale found in semiconductor chip manufacturing. The specific instances of techniques developed here include molecular-ruler lithography and a series of nanoscale chemical patterning methods. Molecular-ruler lithography utilizes self-assembled multilayered films as a sidewall spacer on initial photolithographically patterned gold features (parent) to place a second-generation feature (daughter) in precise proximity to the parent. The parent-daughter separation, which is on the nanometer length scale, is defined by the thickness of the molecular-ruler resist. Analogous to protocols followed in industry to evaluate lithographic performance, electrical test-pad structures were designed to interrogate the nanostructures patterned by molecular-ruler nanolithography, failure modes creating electrical shorts were mapped to each lithographic step, and subsequent lithographic optimization was performed to pattern nanoscale devices with excellent electrical performance. The optimized lithographic processes were applied to generate nanoscale devices such as nanowires and thin-film transistors (TFTs). Metallic nanowires were patterned by depositing a tertiary generation material in the nanogap and surrounding micron-scale regions, and then chemically removing the parent and daughter structures selectively. This processing was also performed on silicon-on-insulator substrates and the metallic nanowires were used as a hard mask to transfer the pattern to the single crystalline silicon epilayer resulting in a quaternary generation structure of single-crystalline silicon nanowire field-effect transistors. Additionally, the proof of concept for patterning nanoscale pentacene TFTs utilizing molecular-rulers was demonstrated. For applications in sub-100-nm lithography, the limitations on the relative heights of parent and daughter structures were overcome and processes to integrate molecular-ruler nanolithography with existing complementary metal-oxide-semiconductor (CMOS) processing were developed. Pattern transfer to underlying SiO2 substrates has opened a new avenue of opportunities to apply these nanostructures in nanofluidics and in non-traditional lithography such as imprint lithography. Additionally, the molecular-ruler process has been shown to increase the spatial density of features created by high-resolution techniques such as electron-beam lithography. A limitation of photolithography is its inability to pattern chemical functionality on surfaces. To overcome this limitation, two techniques were developed to extend nanolithography beyond semiconductors and apply them to patterning of self-assembled monolayers. First, a novel bilayer resist was devised to protect and to pattern chemical functionality on surfaces by being able to withstand conditions necessary for both chemical self-assembly and photooxidation of the Au-S bond while not disrupting the preexisting SAM. In addition to photolithography, soft-lithographic approaches such as microcontact printing are often used to create chemical patterns. In this work, a technique for the creation of chemical patterns of inserted molecules with dilute coverages (≤10%) was implemented. As part of the research in chemical patterning, a method for characterizing chemical patterns using scanning electron microscopy has been developed. These tools are the standard for metrology in nanolithography, and thus are readily accessible as our advances in chemical patterning are adopted and applied by the lithography community.

Characterization of Disease-Related Covariance Topographies with SSMPCA Toolbox: Effects of Spatial Normalization and PET Scanners

PubMed Central

Peng, Shichun; Ma, Yilong; Spetsieris, Phoebe G; Mattis, Paul; Feigin, Andrew; Dhawan, Vijay; Eidelberg, David

2013-01-01

In order to generate imaging biomarkers from disease-specific brain networks, we have implemented a general toolbox to rapidly perform scaled subprofile modeling (SSM) based on principal component analysis (PCA) on brain images of patients and normals. This SSMPCA toolbox can define spatial covariance patterns whose expression in individual subjects can discriminate patients from controls or predict behavioral measures. The technique may depend on differences in spatial normalization algorithms and brain imaging systems. We have evaluated the reproducibility of characteristic metabolic patterns generated by SSMPCA in patients with Parkinson's disease (PD). We used [18F]fluorodeoxyglucose PET scans from PD patients and normal controls. Motor-related (PDRP) and cognition-related (PDCP) metabolic patterns were derived from images spatially normalized using four versions of SPM software (spm99, spm2, spm5 and spm8). Differences between these patterns and subject scores were compared across multiple independent groups of patients and control subjects. These patterns and subject scores were highly reproducible with different normalization programs in terms of disease discrimination and cognitive correlation. Subject scores were also comparable in PD patients imaged across multiple PET scanners. Our findings confirm a very high degree of consistency among brain networks and their clinical correlates in PD using images normalized in four different SPM platforms. SSMPCA toolbox can be used reliably for generating disease-specific imaging biomarkers despite the continued evolution of image preprocessing software in the neuroimaging community. Network expressions can be quantified in individual patients independent of different physical characteristics of PET cameras. PMID:23671030

Characterization of disease-related covariance topographies with SSMPCA toolbox: effects of spatial normalization and PET scanners.

PubMed

Peng, Shichun; Ma, Yilong; Spetsieris, Phoebe G; Mattis, Paul; Feigin, Andrew; Dhawan, Vijay; Eidelberg, David

2014-05-01

To generate imaging biomarkers from disease-specific brain networks, we have implemented a general toolbox to rapidly perform scaled subprofile modeling (SSM) based on principal component analysis (PCA) on brain images of patients and normals. This SSMPCA toolbox can define spatial covariance patterns whose expression in individual subjects can discriminate patients from controls or predict behavioral measures. The technique may depend on differences in spatial normalization algorithms and brain imaging systems. We have evaluated the reproducibility of characteristic metabolic patterns generated by SSMPCA in patients with Parkinson's disease (PD). We used [(18) F]fluorodeoxyglucose PET scans from patients with PD and normal controls. Motor-related (PDRP) and cognition-related (PDCP) metabolic patterns were derived from images spatially normalized using four versions of SPM software (spm99, spm2, spm5, and spm8). Differences between these patterns and subject scores were compared across multiple independent groups of patients and control subjects. These patterns and subject scores were highly reproducible with different normalization programs in terms of disease discrimination and cognitive correlation. Subject scores were also comparable in patients with PD imaged across multiple PET scanners. Our findings confirm a very high degree of consistency among brain networks and their clinical correlates in PD using images normalized in four different SPM platforms. SSMPCA toolbox can be used reliably for generating disease-specific imaging biomarkers despite the continued evolution of image preprocessing software in the neuroimaging community. Network expressions can be quantified in individual patients independent of different physical characteristics of PET cameras. Copyright © 2013 Wiley Periodicals, Inc.

Mechanical Influences on Morphogenesis of the Knee Joint Revealed through Morphological, Molecular and Computational Analysis of Immobilised Embryos

PubMed Central

Roddy, Karen A.; Prendergast, Patrick J.; Murphy, Paula

2011-01-01

Very little is known about the regulation of morphogenesis in synovial joints. Mechanical forces generated from muscle contractions are required for normal development of several aspects of normal skeletogenesis. Here we show that biophysical stimuli generated by muscle contractions impact multiple events during chick knee joint morphogenesis influencing differential growth of the skeletal rudiment epiphyses and patterning of the emerging tissues in the joint interzone. Immobilisation of chick embryos was achieved through treatment with the neuromuscular blocking agent Decamethonium Bromide. The effects on development of the knee joint were examined using a combination of computational modelling to predict alterations in biophysical stimuli, detailed morphometric analysis of 3D digital representations, cell proliferation assays and in situ hybridisation to examine the expression of a selected panel of genes known to regulate joint development. This work revealed the precise changes to shape, particularly in the distal femur, that occur in an altered mechanical environment, corresponding to predicted changes in the spatial and dynamic patterns of mechanical stimuli and region specific changes in cell proliferation rates. In addition, we show altered patterning of the emerging tissues of the joint interzone with the loss of clearly defined and organised cell territories revealed by loss of characteristic interzone gene expression and abnormal expression of cartilage markers. This work shows that local dynamic patterns of biophysical stimuli generated from muscle contractions in the embryo act as a source of positional information guiding patterning and morphogenesis of the developing knee joint. PMID:21386908

Neural mechanism of optimal limb coordination in crustacean swimming

PubMed Central

Zhang, Calvin; Guy, Robert D.; Mulloney, Brian; Zhang, Qinghai; Lewis, Timothy J.

2014-01-01

A fundamental challenge in neuroscience is to understand how biologically salient motor behaviors emerge from properties of the underlying neural circuits. Crayfish, krill, prawns, lobsters, and other long-tailed crustaceans swim by rhythmically moving limbs called swimmerets. Over the entire biological range of animal size and paddling frequency, movements of adjacent swimmerets maintain an approximate quarter-period phase difference with the more posterior limbs leading the cycle. We use a computational fluid dynamics model to show that this frequency-invariant stroke pattern is the most effective and mechanically efficient paddling rhythm across the full range of biologically relevant Reynolds numbers in crustacean swimming. We then show that the organization of the neural circuit underlying swimmeret coordination provides a robust mechanism for generating this stroke pattern. Specifically, the wave-like limb coordination emerges robustly from a combination of the half-center structure of the local central pattern generating circuits (CPGs) that drive the movements of each limb, the asymmetric network topology of the connections between local CPGs, and the phase response properties of the local CPGs, which we measure experimentally. Thus, the crustacean swimmeret system serves as a concrete example in which the architecture of a neural circuit leads to optimal behavior in a robust manner. Furthermore, we consider all possible connection topologies between local CPGs and show that the natural connectivity pattern generates the biomechanically optimal stroke pattern most robustly. Given the high metabolic cost of crustacean swimming, our results suggest that natural selection has pushed the swimmeret neural circuit toward a connection topology that produces optimal behavior. PMID:25201976

The generation of vertebral segmental patterning in the chick embryo

PubMed Central

Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

2012-01-01

We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline. PMID:22458512

Laser Shock Wave-Assisted Patterning on NiTi Shape Memory Alloy Surfaces

NASA Astrophysics Data System (ADS)

Ilhom, Saidjafarzoda; Seyitliyev, Dovletgeldi; Kholikov, Khomidkohodza; Thomas, Zachary; Er, Ali O.; Li, Peizhen; Karaca, Haluk E.; San, Omer

2018-01-01

Shape memory alloys (SMAs) are a unique class of smart materials and they were employed in various applications in engineering, biomedical, and aerospace technologies. Here, we report an advanced, efficient, and low-cost direct imprinting method with low environmental impact to create thermally controllable surface patterns. Patterned microindents were generated on Ni50Ti50 (at. %) SMAs using an Nd:YAG laser with 1064 nm wavelength at 10 Hz. Laser pulses at selected fluences were focused on the NiTi surface and generated pressure pulses of up to a few GPa. Optical microscope images showed that surface patterns with tailorable sizes can be obtained. The depth of the patterns increases with laser power and irradiation time. Upon heating, the depth profile of SMA surfaces changed where the maximum depth recovery ratio of 30% was observed. Recovery ratio decreased and stabilized when the number of pulses and thus the well depth were further increased. A numerical simulation of pressure evolution in shape memory alloys showed a good agreement with the experimental results. The stress wave closely followed the rise time of the laser pulse to its peak value and initial decay. Rapid attenuation and dispersion of the stress wave were found in our simulation.

Rhythm Pattern of Sole through Electrification of the Human Body When Walking

NASA Astrophysics Data System (ADS)

Takiguchi, Kiyoaki; Wada, Takayuki; Tohyama, Shigeki

The rhythm of automatic cyclic movements such as walking is known to be generated by a rhythm generator called CPG in the spinal cord. The measurement of rhythm characteristics in walking is considered to be important for analyzing human bipedal walking and adaptive walking on irregular terrain. In particular, the soles that contact the terrain surface perform flexible movements similar to the movement of the fins of a lungfish, which is considered to be the predecessor of land animals. The sole movements are believed to be a basic movement acquired during prehistoric times. The detailed rhythm pattern of sole motion is considered to be important. We developed a method for measuring electrification without installing device on a subject's body and footwear for stabilizing the electrification of the human body. We measured the rhythm pattern of 20 subjects including 4 infants when walking by using this system and the corresponding equipment. Therefore, we confirmed the commonality of the correlative rhythm patterns of 20 subjects. Further, with regard to an individual subject, the reproducibility of a rhythm pattern with strong correlation coefficient > 0.93 ± 0.5 (mean ± SD) concerning rhythms of trials that are differently conducted on adult subjects could be confirmed.

Mathematical model of sediment and solute transport along slope land in different rainfall pattern conditions

PubMed Central

Tao, Wanghai; Wu, Junhu; Wang, Quanjiu

2017-01-01

Rainfall erosion is a major cause of inducing soil degradation, and rainfall patterns have a significant influence on the process of sediment yield and nutrient loss. The mathematical models developed in this study were used to simulate the sediment and nutrient loss in surface runoff. Four rainfall patterns, each with a different rainfall intensity variation, were applied during the simulated rainfall experiments. These patterns were designated as: uniform-type, increasing-type, increasing- decreasing -type and decreasing-type. The results revealed that changes in the rainfall intensity can have an appreciable impact on the process of runoff generation, but only a slight effect on the total amount of runoff generated. Variations in the rainfall intensity in a rainfall event not only had a significant effect on the process of sediment yield and nutrient loss, but also the total amount of sediment and nutrient produced, and early high rainfall intensity may lead to the most severe erosion and nutrient loss. In this study, the calculated data concur with the measured values. The model can be used to predict the process of surface runoff, sediment transport and nutrient loss associated with different rainfall patterns. PMID:28272431

Stress-induced thermotolerance of ventilatory motor pattern generation in the locust, Locusta migratoria.

PubMed

Newman, Amy E M; Foerster, Melody; Shoemaker, Kelly L; Robertson, R Meldrum

2003-11-01

Ventilation is a crucial motor activity that provides organisms with an adequate circulation of respiratory gases. For animals that exist in harsh environments, an important goal is to protect ventilation under extreme conditions. Heat shock, anoxia, and cold shock are environmental stresses that have previously been shown to trigger protective responses. We used the locust to examine stress-induced thermotolerance by monitoring the ability of the central nervous system to generate ventilatory motor patterns during a subsequent heat exposure. Preparations from pre-stressed animals had an increased incidence of motor pattern recovery following heat-induced failure, however, prior stress did not alter the characteristics of the ventilatory motor pattern. During constant heat exposure at sub-lethal temperatures, we observed a protective effect of heat shock pre-treatment. Serotonin application had similar effects on motor patterns when compared to prior heat shock. These studies are consistent with previous studies that indicate prior exposure to extreme temperatures and hypoxia can protect neural operation against high temperature stress. They further suggest that the protective mechanism is a time-dependent process best revealed during prolonged exposure to extreme temperatures and is mediated by a neuromodulator such as serotonin.

Laser Shock Wave-Assisted Patterning on NiTi Shape Memory Alloy Surfaces

NASA Astrophysics Data System (ADS)

Ilhom, Saidjafarzoda; Seyitliyev, Dovletgeldi; Kholikov, Khomidkohodza; Thomas, Zachary; Er, Ali O.; Li, Peizhen; Karaca, Haluk E.; San, Omer

2018-03-01

Shape memory alloys (SMAs) are a unique class of smart materials and they were employed in various applications in engineering, biomedical, and aerospace technologies. Here, we report an advanced, efficient, and low-cost direct imprinting method with low environmental impact to create thermally controllable surface patterns. Patterned microindents were generated on Ni50Ti50 (at. %) SMAs using an Nd:YAG laser with 1064 nm wavelength at 10 Hz. Laser pulses at selected fluences were focused on the NiTi surface and generated pressure pulses of up to a few GPa. Optical microscope images showed that surface patterns with tailorable sizes can be obtained. The depth of the patterns increases with laser power and irradiation time. Upon heating, the depth profile of SMA surfaces changed where the maximum depth recovery ratio of 30% was observed. Recovery ratio decreased and stabilized when the number of pulses and thus the well depth were further increased. A numerical simulation of pressure evolution in shape memory alloys showed a good agreement with the experimental results. The stress wave closely followed the rise time of the laser pulse to its peak value and initial decay. Rapid attenuation and dispersion of the stress wave were found in our simulation.

Application of genotypic and phenotypic analyses to commercial probiotic strain identity and relatedness.

PubMed

Yeung, P S M; Kitts, C L; Cano, R; Tong, P S; Sanders, M E

2004-01-01

The objective of this study was to generate strain-specific genomic patterns of a bank of 67 commercial and reference probiotic strains, with a focus on probiotic lactobacilli. Pulsed-field gel electrophoresis (PFGE) was used as the primary method for strain differentiation. This method was compared with carbohydrate fermentation analysis. To supplement visual comparison, PFGE patterns were analysed quantitatively by cluster analysis using unweighted pair group method with arithmetic averages. SmaI, NotI and XbaI were found to effectively generate clear and easy-to-interpret PFGE patterns of a range of probiotic strains. Some probiotic strains from different sources shared highly similar PFGE patterns. Results document the value of genotypic strain identification methods, combined with phenotypic methods, for determining probiotic strain identity and relatedness. No correlation was found between relatedness determined by carbohydrate fermentation profiles alone compared with PFGE analysis alone. Some commercial strains are probably derived from similar sources. This approach is valuable to the probiotic industry to develop commercial strain identification patterns, to provide quality control of strain manufacturing production runs, to track use of protected strains and to determine the relatedness among different research and commercial probiotic strains.

Regulatory sequence analysis tools.

PubMed

van Helden, Jacques

2003-07-01

The web resource Regulatory Sequence Analysis Tools (RSAT) (http://rsat.ulb.ac.be/rsat) offers a collection of software tools dedicated to the prediction of regulatory sites in non-coding DNA sequences. These tools include sequence retrieval, pattern discovery, pattern matching, genome-scale pattern matching, feature-map drawing, random sequence generation and other utilities. Alternative formats are supported for the representation of regulatory motifs (strings or position-specific scoring matrices) and several algorithms are proposed for pattern discovery. RSAT currently holds >100 fully sequenced genomes and these data are regularly updated from GenBank.

Numerical solutions for patterns statistics on Markov chains.

PubMed

Nuel, Gregory

2006-01-01

We propose here a review of the methods available to compute pattern statistics on text generated by a Markov source. Theoretical, but also numerical aspects are detailed for a wide range of techniques (exact, Gaussian, large deviations, binomial and compound Poisson). The SPatt package (Statistics for Pattern, free software available at http://stat.genopole.cnrs.fr/spatt) implementing all these methods is then used to compare all these approaches in terms of computational time and reliability in the most complete pattern statistics benchmark available at the present time.

Lacunarity study of speckle patterns produced by rough surfaces

NASA Astrophysics Data System (ADS)

Dias, M. R. B.; Dornelas, D.; Balthazar, W. F.; Huguenin, J. A. O.; da Silva, L.

2017-11-01

In this work we report on the study of Lacunarity of digital speckle patterns generated by rough surfaces. The study of Lacunarity of speckle patterns was performed on both static and moving rough surfaces. The results show that the Lacunarity is sensitive to the surface roughness, which suggests that it can be used to perform indirect measurement of surface roughness as well as to monitor defects, or variations of roughness, of metallic moving surfaces. Our results show the robustness of this statistical tool applied to speckle pattern in order to study surface roughness.

Information-generated Influence as a Function of Locus-of-Control Patterns in Children

ERIC Educational Resources Information Center

Wolk, Stephen; Eliot, John

1974-01-01

Investigated the degree to which an individual disregards information about himself and his environment, as a function of his locus of control patterns, and hence is less responsive to or influenced by a given segment of information. Subjects were 341 fourth- and fifth-grade children. (SDH)

Motor Patterns in Walking.

PubMed

Lacquaniti, F.; Grasso, R.; Zago, M.

1999-08-01

Despite the fact that locomotion may differ widely in mammals, common principles of kinematic control are at work. These reflect common mechanical and neural constraints. The former are related to the need to maintain balance and to limit energy expenditure. The latter are related to the organization of the central pattern-generating networks.

Equilibrium theory of island biogeography: A review

Treesearch

Angela D. Yu; Simon A. Lei

2001-01-01

The topography, climatic pattern, location, and origin of islands generate unique patterns of species distribution. The equilibrium theory of island biogeography creates a general framework in which the study of taxon distribution and broad island trends may be conducted. Critical components of the equilibrium theory include the species-area relationship, island-...

Photo-Definable Self Assembled Maerials

DOEpatents

DOSHI, DHAVAL; [et al

2004-10-26

The present invention provides a mesoporous material comprising at least one region of mesoporous material patterned at a lithographic scale. The present invention also provides a a method for forming a patterned mesoporous material comprising: coating a sol on a substrate to form a film, the sol comprising: a templating molecule, a photoactivator generator, a material capable of being sol-gel processed, water, and a solvent; and exposing the film to light to form a patterned mesoporous material.

Rayleigh-Taylor instability and mushroom-pattern formation in a two-component Bose-Einstein condensate

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

Sasaki, Kazuki; Suzuki, Naoya; Saito, Hiroki

2009-12-15

The Rayleigh-Taylor instability at the interface in an immiscible two-component Bose-Einstein condensate is investigated using the mean field and Bogoliubov theories. Rayleigh-Taylor fingers are found to grow from the interface and mushroom patterns are formed. Quantized vortex rings and vortex lines are then generated around the mushrooms. The Rayleigh-Taylor instability and mushroom-pattern formation can be observed in a trapped system.

Patterns and Prevalence of School Access, Transitions and Equity in South Africa: Secondary Analyses of BT20 Large-Scale Data Sources. CREATE Pathways to Access. Research Monograph No. 27

ERIC Educational Resources Information Center

Fleisch, Brahm; Shindler, Jennifer

2009-01-01

This monograph looks at patterns and prevalence of initial school enrolment, late entry, attainment promotion, and repetition in urban South Africa. The paper pays special attention to the particular gender nature of the patterns of school participation. The study analyses data generated in the genuine representative cohort study, Birth-to-Twenty…

Fabrication of patterned surface by soft lithographic technique for confinement of lipid bilayer

NASA Astrophysics Data System (ADS)

Moulick, Ranjita Ghosh; Mayer, Dirk

2018-04-01

In this paper we demonstrated that a 3D pattern can be well transferred from a silicon Master to a gold substrate using µcontact printing. In this process 1-Octadecanthiol served as an ink and printing followed by etching generated the desired pattern on the gold substrate. The prepatterned substrate was also used for lipid vesicle fusion and revealed that lipid molecules selectively bind to the gold layer.

Feminized Intergenerational Mobility Without Assimilation? Post-1965 U.S. Immigrants and the Gender Revolution.

PubMed

Park, Julie; Nawyn, Stephanie J; Benetsky, Megan J

2015-10-01

Women in the United States have made significant socioeconomic advances over the last generation. The second generation of post-1965 immigrants came of age during this "gender revolution." However, assimilation theories focus mainly on racial/ethnic trajectories. Do gendered trajectories between and within groups better capture mobility patterns? Using the 1980 decennial census and the 2003-2007 Current Population Survey (CPS), we observe the socioeconomic status of Latino and Asian immigrant parents and their second-generation children 25 years later. We compare the educational, occupational, and earnings attainment of second-generation daughters and sons with that of their immigrant mothers and fathers. We simultaneously compare those socioeconomic trajectories with a U.S.-born white, non-Latino reference group. We find that second-generation women experience greater status attainment than both their mothers and their male counterparts, but the earnings of second-generation women lag behind those of men. However, because white mainstream women experienced similar intergenerational mobility, many gaps between the second generation and the mainstream remain. These patterns remain even after we control for parenthood status. With feminized intergenerational mobility occurring similarly across race, the racial/ethnic gaps observed in 1980 narrow but persist into the next generation for many outcomes. Both gender and race shape mobility trajectories, so ignoring either leads to an incomplete picture of assimilation.

Increasing the Efficiency of a Thermoelectric Generator Using an Evaporative Cooling System

NASA Astrophysics Data System (ADS)

Boonyasri, M.; Jamradloedluk, J.; Lertsatitthanakorn, C.; Therdyothin, A.; Soponronnarit, S.

2017-05-01

A system for reducing heat from the cold side of a thermoelectric (TE) power generator, based on the principle of evaporative cooling, is presented. An evaporative cooling system could increase the conversion efficiency of a TE generator. To this end, two sets of TE generators were constructed. Both TE generators were composed of five TE power modules. The cold and hot sides of the TE modules were fixed to rectangular fin heat sinks. The hot side heat sinks were inserted in a hot gas duct. The cold side of one set was cooled by the cooling air from a counter flow evaporative cooling system, whereas the other set was cooled by the parallel flow evaporative cooling system. The counter flow pattern had better performance than the parallel flow pattern. A comparison between the TE generator with and without an evaporative cooling system was made. Experimental results show that the power output increased by using the evaporative cooling system. This can significantly increase the TE conversion efficiency. The evaporative cooling system increased the power output of the TE generator from 22.9 W of ambient air flowing through the heat sinks to 28.6 W at the hot gas temperature of 350°C (an increase of about 24.8%). The present study shows the promising potential of using TE generators with evaporative cooling for waste heat recovery.

Control of Vertebrate Respiration and Locomotion: A Brief Account.

ERIC Educational Resources Information Center

Feldman, Jack L.; Grillner, Sten

1983-01-01

Areas considered in this discussion include: activation/modulation of movement; control of motoneuronal discharge by excitation/inhibition; neural generation of movement synergies (considering interaction of central/peripheral elements, phasic gating of reflex effects, and neuronal organization of central pattern generators); protean nature of…

Continuities in Antisocial Behavior and Parenting across Three Generations

ERIC Educational Resources Information Center

Smith, Carolyn A.; Farrington, David P.

2004-01-01

Background: Accumulating evidence indicates that there are intergenerational continuities in antisocial behavior, and that parenting patterns play a role in these continuities. Very few studies, however, enable assessment across two generations of children at comparable ages, employing independent reporters and comparable measurements. The present…

It's Life, but Not as We Know It.

ERIC Educational Resources Information Center

Parr, Alan

1992-01-01

Presents the game "Life91," an adaptation of Conway's "The Game of Life." Played on a hexagonal board, the game generates number patterns of population size by rules that determine cell growth and death from one generation to another. An example illustrates the process. (MDH)

Reflections of Low Income, Second Generation Latinas about Experiences in Depression Therapy

PubMed Central

Heilemann, MarySue V.; Pieters, Huibrie C.; Dornig, Katrina

2016-01-01

Depression is higher among second generation Latinas compared to immigrants but mental health treatment is stigmatized. Therefore, second generation Latinas were interviewed after completing an eight-session depression treatment program to gain insight on what they found valuable about their therapy experiences. Constructivist Grounded Theory guided data collection and analysis which showed that women valued treatment more when they recognized their needs were being met, the therapist was a worthy co-pilot, and the program’s structure had flexibility. Four processes were considered important to their work in therapy: understanding feelings about past events, seeing patterns, accepting self, and changing family patterns but still being “family”. Post therapy, women valued their enhanced confidence and a “toolbelt” of techniques they gained for self-treatment. These findings have implications for designing future depression treatment programs that are more likely to be desirable and effective for the growing subgroup of underserved second generation Latinas in the U.S. PMID:26825479

Shear wave speed and dispersion measurements using crawling wave chirps.

PubMed

Hah, Zaegyoo; Partin, Alexander; Parker, Kevin J

2014-10-01

This article demonstrates the measurement of shear wave speed and shear speed dispersion of biomaterials using a chirp signal that launches waves over a range of frequencies. A biomaterial is vibrated by two vibration sources that generate shear waves inside the medium, which is scanned by an ultrasound imaging system. Doppler processing of the acquired signal produces an image of the square of vibration amplitude that shows repetitive constructive and destructive interference patterns called "crawling waves." With a chirp vibration signal, successive Doppler frames are generated from different source frequencies. Collected frames generate a distinctive pattern which is used to calculate the shear speed and shear speed dispersion. A special reciprocal chirp is designed such that the equi-phase lines of a motion slice image are straight lines. Detailed analysis is provided to generate a closed-form solution for calculating the shear wave speed and the dispersion. Also several phantoms and an ex vivo human liver sample are scanned and the estimation results are presented. © The Author(s) 2014.

Peripheral mechanisms for vocal production in birds - differences and similarities to human speech and singing.

PubMed

Riede, Tobias; Goller, Franz

2010-10-01

Song production in songbirds is a model system for studying learned vocal behavior. As in humans, bird phonation involves three main motor systems (respiration, vocal organ and vocal tract). The avian respiratory mechanism uses pressure regulation in air sacs to ventilate a rigid lung. In songbirds sound is generated with two independently controlled sound sources, which reside in a uniquely avian vocal organ, the syrinx. However, the physical sound generation mechanism in the syrinx shows strong analogies to that in the human larynx, such that both can be characterized as myoelastic-aerodynamic sound sources. Similarities include active adduction and abduction, oscillating tissue masses which modulate flow rate through the organ and a layered structure of the oscillating tissue masses giving rise to complex viscoelastic properties. Differences in the functional morphology of the sound producing system between birds and humans require specific motor control patterns. The songbird vocal apparatus is adapted for high speed, suggesting that temporal patterns and fast modulation of sound features are important in acoustic communication. Rapid respiratory patterns determine the coarse temporal structure of song and maintain gas exchange even during very long songs. The respiratory system also contributes to the fine control of airflow. Muscular control of the vocal organ regulates airflow and acoustic features. The upper vocal tract of birds filters the sounds generated in the syrinx, and filter properties are actively adjusted. Nonlinear source-filter interactions may also play a role. The unique morphology and biomechanical system for sound production in birds presents an interesting model for exploring parallels in control mechanisms that give rise to highly convergent physical patterns of sound generation. More comparative work should provide a rich source for our understanding of the evolution of complex sound producing systems. Copyright © 2009 Elsevier Inc. All rights reserved.

Solar-based navigation for robotic explorers

NASA Astrophysics Data System (ADS)

Shillcutt, Kimberly Jo

2000-12-01

This thesis introduces the application of solar position and shadowing information to robotic exploration. Power is a critical resource for robots with remote, long-term missions, so this research focuses on the power generation capabilities of robotic explorers during navigational tasks, in addition to power consumption. Solar power is primarily considered, with the possibility of wind power also contemplated. Information about the environment, including the solar ephemeris, terrain features, time of day, and surface location, is incorporated into a planning structure, allowing robots to accurately predict shadowing and thus potential costs and gains during navigational tasks. By evaluating its potential to generate and expend power, a robot can extend its lifetime and accomplishments. The primary tasks studied are coverage patterns, with a variety of plans developed for this research. The use of sun, terrain and temporal information also enables new capabilities of identifying and following sun-synchronous and sun-seeking paths. Digital elevation maps are combined with an ephemeris algorithm to calculate the altitude and azimuth of the sun from surface locations, and to identify and map shadows. Solar navigation path simulators use this information to perform searches through two-dimensional space, while considering temporal changes. Step by step simulations of coverage patterns also incorporate time in addition to location. Evaluations of solar and wind power generation, power consumption, area coverage, area overlap, and time are generated for sets of coverage patterns, with on-board environmental information linked to the simulations. This research is implemented on the Nomad robot for the Robotic Antarctic Meteorite Search. Simulators have been developed for coverage pattern tests, as well as for sun-synchronous and sun-seeking path searches. Results of field work and simulations are reported and analyzed, with demonstrated improvements in efficiency, productivity and lifetime of robotic explorers, along with new solar navigation abilities.

Simulated Models Suggest That Price per Calorie Is the Dominant Price Metric That Low-Income Individuals Use for Food Decision Making123

PubMed Central

2016-01-01

Background: The price of food has long been considered one of the major factors that affects food choices. However, the price metric (e.g., the price of food per calorie or the price of food per gram) that individuals predominantly use when making food choices is unclear. Understanding which price metric is used is especially important for studying individuals with severe budget constraints because food price then becomes even more important in food choice. Objective: We assessed which price metric is used by low-income individuals in deciding what to eat. Methods: With the use of data from NHANES and the USDA Food and Nutrient Database for Dietary Studies, we created an agent-based model that simulated an environment representing the US population, wherein individuals were modeled as agents with a specific weight, age, and income. In our model, agents made dietary food choices while meeting their budget limits with the use of 1 of 3 different metrics for decision making: energy cost (price per calorie), unit price (price per gram), and serving price (price per serving). The food consumption patterns generated by our model were compared to 3 independent data sets. Results: The food choice behaviors observed in 2 of the data sets were found to be closest to the simulated dietary patterns generated by the price per calorie metric. The behaviors observed in the third data set were equidistant from the patterns generated by price per calorie and price per serving metrics, whereas results generated by the price per gram metric were further away. Conclusions: Our simulations suggest that dietary food choice based on price per calorie best matches actual consumption patterns and may therefore be the most salient price metric for low-income populations. PMID:27655757