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Sample records for punctate patterns ofmembrane-bound

  1. TUNABLE TENSOR VOTING FOR REGULARIZING PUNCTATE PATTERNS OFMEMBRANE-BOUND PROTEIN SIGNALS

    SciTech Connect

    Loss, Leandro; Bebis, George; Parvin, Bahram

    2009-04-29

    Membrane-bound protein, expressed in the basal-lateral region, is heterogeneous and an important endpoint for understanding biological processes. At the optical resolution, membrane-bound protein can be visualized as being diffused (e.g., E-cadherin), punctate (e.g., connexin), or simultaneously diffused and punctate as a result of sample preparation or conditioning. Furthermore, there is a significant amount of heterogeneity as a result of technical and biological variations. This paper aims at enhancing membrane-bound proteins that are expressed between epithelial cells so that quantitative analysis can be enabled on a cell-by-cell basis. We propose a method to detect and enhance membrane-bound protein signal from noisy images. More precisely, we build upon the tensor voting framework in order to produce an efficient method to detect and refine perceptually interesting linear structures in images. The novelty of the proposed method is in its iterative tuning of the tensor voting fields, which allows the concentration of the votes only over areas of interest. The method is shown to produce high quality enhancements of membrane-bound protein signals with combined punctate and diffused characteristics. Experimental results demonstrate the benefits of using tunable tensor voting for enhancing and differentiating cell-cell adhesion mediated by integral cell membrane protein.

  2. Automated Learning of Subcellular Variation among Punctate Protein Patterns and a Generative Model of Their Relation to Microtubules

    PubMed Central

    Johnson, Gregory R.; Li, Jieyue; Shariff, Aabid; Rohde, Gustavo K.; Murphy, Robert F.

    2015-01-01

    Characterizing the spatial distribution of proteins directly from microscopy images is a difficult problem with numerous applications in cell biology (e.g. identifying motor-related proteins) and clinical research (e.g. identification of cancer biomarkers). Here we describe the design of a system that provides automated analysis of punctate protein patterns in microscope images, including quantification of their relationships to microtubules. We constructed the system using confocal immunofluorescence microscopy images from the Human Protein Atlas project for 11 punctate proteins in three cultured cell lines. These proteins have previously been characterized as being primarily located in punctate structures, but their images had all been annotated by visual examination as being simply “vesicular”. We were able to show that these patterns could be distinguished from each other with high accuracy, and we were able to assign to one of these subclasses hundreds of proteins whose subcellular localization had not previously been well defined. In addition to providing these novel annotations, we built a generative approach to modeling of punctate distributions that captures the essential characteristics of the distinct patterns. Such models are expected to be valuable for representing and summarizing each pattern and for constructing systems biology simulations of cell behaviors. PMID:26624011

  3. PUNCTATE VASCULAR EXPRESSION1 Is a Novel Maize Gene Required for Leaf Pattern Formation That Functions Downstream of the Trans-Acting Small Interfering RNA Pathway1[C][W][OA

    PubMed Central

    Zhang, Xiaolan; Douglas, Ryan N.; Strable, Josh; Lee, Michelle; Buckner, Brent; Janick-Buckner, Diane; Schnable, Patrick S.; Timmermans, Marja C.P.; Scanlon, Michael J.

    2012-01-01

    The maize (Zea mays) gene RAGGED SEEDLING2-R (RGD2-R) encodes an ARGONAUTE7-like protein required for the biogenesis of trans-acting small interfering RNA, which regulates the accumulation of AUXIN RESPONSE FACTOR3A transcripts in shoots. Although dorsiventral polarity is established in the narrow and cylindrical leaves of rgd2-R mutant plants, swapping of adaxial/abaxial epidermal identity occurs and suggests a model wherein RGD2 is required to coordinate dorsiventral and mediolateral patterning in maize leaves. Laser microdissection-microarray analyses of the rgd2-R mutant shoot apical meristem identified a novel gene, PUNCTATE VASCULAR EXPRESSION1 (PVE1), that is down-regulated in rgd2-R mutant apices. Transcripts of PVE1 provide an early molecular marker for vascular morphogenesis. Reverse genetic analyses suggest that PVE1 functions during vascular development and in mediolateral and dorsiventral patterning of maize leaves. Molecular genetic analyses of PVE1 and of rgd2-R;pve1-M2 double mutants suggest a model wherein PVE1 functions downstream of RGD2 in a pathway that intersects and interacts with the trans-acting small interfering RNA pathway. PMID:22669891

  4. Unilateral Punctate Keratitis Secondary to Wallenberg Syndrome

    PubMed Central

    Boto, Ana; Del Hierro, Almudena; Capote, Maria; Noval, Susana; Garcia, Amanda; Santiago, Susana

    2014-01-01

    We studied three patients who developed left unilateral punctate keratitis after suffering left-sided Wallenberg Syndrome. A complex evolution occurred in two of them. In all cases, neurophysiological studies showed damage in the trigeminal sensory component at the bulbar level. Corneal involvement secondary to Wallenberg syndrome is a rare cause of unilateral superficial punctate keratitis. The loss of corneal sensitivity caused by trigeminal neuropathy leads to epithelial erosions that are frequently unobserved by the patient, resulting in a high risk of corneal-ulcer development with the possibility of superinfection. Neurophysiological studies can help to locate the anatomical level of damage at the ophthalmic branch of the trigeminal nerve, confirming the suspected etiology of stroke, and demonstrating that prior vascular involvement coincides with the location of trigeminal nerve damage. In some of these patients, oculofacial pain is a distinctive feature. PMID:24882965

  5. Combined treatment in punctate inner choroidopathy

    PubMed Central

    Terelak-Borys, Barbara; Zagajewska, Katarzyna; Jankowska-Lech, Irmina; Tesla, Piotr; Grabska-Liberek, Iwona

    2016-01-01

    Purpose The purpose of this study was to describe a combination treatment for choroidal neovascular (CNV) membrane, secondary to punctate inner choroidopathy (PIC). Patient and methods A 44-year-old female patient was diagnosed with PIC complicated by the development of recurrent juxtafoveal neovascular membrane. The treatment included a sequence of monotherapy regimens: systemic steroid therapy, photodynamic therapy, and intravitreal injections of vascular endothelial growth factor (VEGF) inhibitor (anti-VEGF). Owing to the CNV membrane resistance to various types of monotherapy, a combination treatment consisting of local injections of steroid underneath the Tenon’s capsule and intravitreal anti-VEGF injections was used. Results Systemic steroid therapy resulted in rapid local improvement with a very short remission period. No positive effects of photodynamic therapy were observed. Sequential anti-VEGF injections led to remission periods of several months. Permanent regression of CNV membrane was achieved following combined local application of steroid and intravitreal anti-VEGF injections. Conclusion A combination treatment including steroid and anti-VEGF medication characterized by anti-inflammatory and antiangiogenic effects may be a very beneficial option for the treatment of recurrent CNV membrane as a complication of PIC. PMID:27729795

  6. Monoclonal Antibodies Against Muscleblind-like 3, a Protein with Punctate Nuclear Localization

    PubMed Central

    Lee, Kyung-Soon; Lewis, K.A.; Tom, Susan; Wayner, Elizabeth A.

    2011-01-01

    Muscleblind-like 3 (MBNL3) belongs to a family of RNA binding proteins that regulate alternative splicing. We have generated a set of monoclonal antibodies (MAbs) against mouse MBNL3, three of which do not cross-react with the other muscleblind-like (MBNL) proteins, MBNL1 and MBNL2. Epitope mapping revealed that MAbs P1C7, P1E7, SP1C2, and P2E6 recognize distinct, non-overlapping segments of the MBNL3 polypeptide sequence. Immunohistochemical staining of proliferating muscle precursor cells localized MBNL3 to the nucleus in a punctate pattern, characteristic of subcellular structures in the nucleus enriched in pre-messenger RNA splicing factors. Although MBNL3 did not co-localize with SC35 and PSP1 (widely used markers of splicing speckles and paraspeckles), the punctate localization pattern of MBNL3 within interchromatin regions of the nucleus is highly predictive of proteins involved in pre-mRNA processing. Monoclonal antibodies specific for mouse MBNL3 will facilitate further investigation of the expression pattern and unique functions of this splicing factor during development and in different adult mouse tissues. PMID:21529292

  7. Point process models for localization and interdependence of punctate cellular structures.

    PubMed

    Li, Ying; Majarian, Timothy D; Naik, Armaghan W; Johnson, Gregory R; Murphy, Robert F

    2016-07-01

    Accurate representations of cellular organization for multiple eukaryotic cell types are required for creating predictive models of dynamic cellular function. To this end, we have previously developed the CellOrganizer platform, an open source system for generative modeling of cellular components from microscopy images. CellOrganizer models capture the inherent heterogeneity in the spatial distribution, size, and quantity of different components among a cell population. Furthermore, CellOrganizer can generate quantitatively realistic synthetic images that reflect the underlying cell population. A current focus of the project is to model the complex, interdependent nature of organelle localization. We built upon previous work on developing multiple non-parametric models of organelles or structures that show punctate patterns. The previous models described the relationships between the subcellular localization of puncta and the positions of cell and nuclear membranes and microtubules. We extend these models to consider the relationship to the endoplasmic reticulum (ER), and to consider the relationship between the positions of different puncta of the same type. Our results do not suggest that the punctate patterns we examined are dependent on ER position or inter- and intra-class proximity. With these results, we built classifiers to update previous assignments of proteins to one of 11 patterns in three distinct cell lines. Our generative models demonstrate the ability to construct statistically accurate representations of puncta localization from simple cellular markers in distinct cell types, capturing the complex phenomena of cellular structure interaction with little human input. This protocol represents a novel approach to vesicular protein annotation, a field that is often neglected in high-throughput microscopy. These results suggest that spatial point process models provide useful insight with respect to the spatial dependence between cellular structures.

  8. Fluorescein Punctate Staining Traced to Superficial Corneal Epithelial Cells by Impression Cytology and Confocal Microscopy

    PubMed Central

    Mokhtarzadeh, Maryam; Casey, Richard

    2011-01-01

    Purpose. The basis of fluorescein-associated superficial punctate staining in dry eyes is controversial. Prior explanations include fluorescein pooling in surface erosive defects, intercellular trapping of fluorescein, and intracellular staining in dead cells. In this study, the hypothesis that punctate erosions are individual cells with enhanced fluorescence was tested. Methods. Ten impression cytology membrane materials were compared, to optimize cellular yield in buccal mucosa and cornea. Clinicocytologic correlation of punctate fluorescent spots was performed in four dry eye patients. Individual punctate spots were localized by fiducial marks in photographs, before and after removal with impression membranes, and were traced in fluorescence microscopy and cytologic staining. Two-way contingency table analysis was used to determine the correlation of punctate spots with cells removed by the membrane. Clinicopathologic correlation of punctate spots was performed in 10 corneas removed in dry eye patients by transplantation for concurrent diseases. Punctate fluorescence was tracked in specimens by fiducial marks and epifluorescence. The distribution of fluorescent spots in specific cell layers of the cornea was determined by confocal microscopy. Results. Cellular yield was greatest with impressions from polytetrafluoroethylene (PTFE [Teflon]; BioPore; Millipore, Billerica, MA) membrane compared with its closest rival (P = 0.019). Punctate fluorescent spots, most of which disappeared after impression cytology (71%), correlated with cells on the membranes (P = 0.009). The punctate spots were more frequent in the superficial cell layers of the cornea (80%) compared with the deepest two layers (0%) (P < 0.00049). Conclusions. Punctate epithelial erosions correspond to enhanced fluorescence in epithelial cells predominantly in superficial layers of the cornea and would be more aptly named fluorescent epithelial cells (FLECs). PMID:21212176

  9. A novel MIP gene mutation analysis in a Chinese family affected with congenital progressive punctate cataract.

    PubMed

    Ding, Xuchen; Zhou, Nan; Lin, Hui; Chen, Jianjun; Zhao, Chunyuan; Zhou, Guangkai; Hejtmancik, J Fielding; Qi, Yanhua

    2014-01-01

    Congenital cataracts are one of the leading causes of visual impairment and blindness in children, and genetic factors play an important role in their development. This study aimed to identify the genetic defects associated with autosomal dominant congenital progressive punctate cataracts in a Chinese family and to explore the potential pathogenesis. Detailed family history and clinical data were recorded, and all the family members' blood samples were collected for DNA extraction. Linkage analysis was performed by microsatellite markers that are associated with punctate cataracts, and logarithm (base 10) of odds (LOD) scores were calculated using the LINKAGE program. Positive two-point LOD scores were obtained at markers D12S1622 (Zmax = 2.71 at θ = 0.0), D12S1724 (Zmax = 2.71 at θ = 0.0), and D12S90 (Zmax = 2.71 at θ = 0.0), which flank the major intrinsic protein of lens fiber (MIP) gene on chromosomal region 12q13. Direct sequencing of the encoding region of the MIP gene revealed a novel mutation (G>D) in exon 4 at nucleotide 644, which caused a substitution of glycine to aspartic acid at codon 215 (p.G215D) for the MIP protein. The mutation cosegregated with all patients with congenital progressive punctate cataracts, but it was absent in the healthy members. Bioinformatics analysis predicted that the mutation affects the function of the MIP protein. The wild type (WT) and G215D mutant of MIP were transfected with green fluorescent protein (GFP) into Hela cells separately, and it was found that the G215D mutant was aberrantly located in the cytoplasm instead of in the plasma membrane. In summary, our study presented genetic and functional evidence linking the new MIP mutation of G215D to autosomal dominant congenital cataracts, which adds to the list of MIP mutations linked to congenital progressive punctate cataracts.

  10. Adjunctive use of systematic retinal thickness map analysis to monitor disease activity in punctate inner choroidopathy.

    PubMed

    Madhusudhan, Savitha; Keane, Pearse A; Denniston, Alastair K

    2016-12-01

    A challenge in the management of 'white dot syndromes' is the lack of sensitive objective measures of disease activity. Retinal thickness maps from spectral domain optical coherence tomography (SD-OCT) inform treatment decisions in other retinal conditions such as age-related macular degeneration and diabetic maculopathy. In this report, we demonstrate their value in providing quantitative monitoring of a patient with punctate inner choroidopathy (PIC). Retinal thickness maps referenced against a baseline scan reliably detected focal areas of increased macular volume in active PIC lesions during symptomatic episodes, highlighting these as 'hot spots' that could be quantified, providing an objective basis for treatment decisions.

  11. Identification of a locus for type I punctate palmoplantar keratoderma on chromosome 15q22–q24

    PubMed Central

    Martinez-Mir, A; Zlotogorski, A; Londono, D; Gordon, D; Grunn, A; Uribe, E; Horev, L; Ruiz, I; Davalos, N; Alayan, O; Liu, J; Gilliam, T; Salas-Alanis, J; Christiano, A

    2003-01-01

    Background: The identification of the molecular basis of disorders of keratinisation has significantly advanced our understanding of skin biology, revealing new information on key structures in the skin, such as the intermediate filaments, desmosomes, and gap junctions. Among these disorders, there is an extraordinarily heterogeneous group known as palmoplantar keratodermas (PPK), for which only a few molecular defects have been described. A particular form of PPK, known as punctate PPK, has been described in a few large autosomal dominant pedigrees, but its genetic basis has yet to be identified. Aim: Identification of the gene for punctate PPK. Methods: Clinical examination and linkage analysis in three families with punctate PPK. Results: A genomewide scan was performed on an extended autosomal dominant pedigree, and linkage to chromosome 15q22–q24 was identified. With the addition of two new families with the same phenotype, we confirmed the mapping of the locus for punctate PPK to a 9.98 cM interval, flanked by markers D15S534 and D15S818 (maximum two point lod score of 4.93 at θ = 0 for marker D15S988). Conclusions: We report the clinical and genetic findings in three pedigrees with the punctate form of PPK. We have mapped a genetic locus for this phenotype to chromosome 15q22–q24, which indicates the identification of a new gene involved in skin integrity. PMID:14684683

  12. Spectral domain optical coherence tomography imaging of punctate outer retinal toxoplasmosis

    PubMed Central

    Lujan, Brandon J.

    2014-01-01

    Punctate outer retinal toxoplasmosis is a recognized phenotype of this common ocular parasite. We present a case presenting with poor visual acuity, but with prompt treatment regaining excellent vision by the final time point. Imaging demonstrates progression of an active lesion adjacent to an inactive retinal scar with color photography, fluorescein angiography, and Spectral Domain Optical Coherence Tomography (SD-OCT). SD-OCT imaging of the chorioretinal scar demonstrated alternating hypertrophy and atrophy of the retinal pigment epithelium along with a discrete break in Bruch’s membrane. At baseline, the active lesion demonstrated a large collection of inflammatory subretinal fluid adjacent to an area of active retinitis. Over time, the subretinal material was found to resolve, there was restoration of the foveal anatomy, and the area of retinitis progressed into a chorioretinal scar. PMID:24843310

  13. Nonsense Mutations in AAGAB Cause Punctate Palmoplantar Keratoderma Type Buschke-Fischer-Brauer

    PubMed Central

    Giehl, Kathrin A.; Eckstein, Gertrud N.; Pasternack, Sandra M.; Praetzel-Wunder, Silke; Ruzicka, Thomas; Lichtner, Peter; Seidl, Kerstin; Rogers, Mike; Graf, Elisabeth; Langbein, Lutz; Braun-Falco, Markus; Betz, Regina C.; Strom, Tim M.

    2012-01-01

    Punctate palmoplantar keratodermas (PPKPs) are rare autosomal-dominant inherited skin diseases that are characterized by multiple hyperkeratotic plaques distributed on the palms and soles. To date, two different loci in chromosomal regions 15q22-15q24 and 8q24.13-8q24.21 have been reported. Pathogenic mutations, however, have yet to be identified. In order to elucidate the genetic cause of PPKP type Buschke-Fischer-Brauer (PPKP1), we performed exome sequencing in five affected individuals from three families, and we identified in chromosomal region 15q22.33-q23 two heterozygous nonsense mutations—c.370C>T (p.Arg124∗) and c.481C>T (p.Arg161∗)—in AAGAB in all affected individuals. Using immunoblot analysis, we showed that both mutations result in premature termination of translation and truncated protein products. Analyses of mRNA of affected individuals revealed that the disease allele is either not detectable or only detectable at low levels. To assess the consequences of the mutations in skin, we performed immunofluorescence analyses. Notably, the amount of granular staining in the keratinocytes of affected individuals was lower in the cytoplasm but higher around the nucleus than it was in the keratinocytes of control individuals. AAGAB encodes the alpha-and gamma-adaptin-binding protein p34 and might play a role in membrane traffic as a chaperone. The identification of mutations, along with the results from additional studies, defines the genetic basis of PPKP1 and provides evidence that AAGAB plays an important role in skin integrity. PMID:23000146

  14. Punctate LC3B expression is a common feature of solid tumors and associated with proliferation, metastasis and poor outcome

    PubMed Central

    Lazova, Rossitza; Camp, Robert L.; Klump, Vincent; Siddiqui, Summar F.; Amaravadi, Ravi K.; Pawelek, John M.

    2014-01-01

    Purpose Measurement of autophagy in cancer and correlation with histopathologic grading or clinical outcomes has been limited. Accordingly, we investigated LC3B as an autophagosome marker by analyzing nearly 1400 tumors from 20 types of cancer, focussing on correlations with clinical outcomes in melanoma and breast cancer. Experimental Design Staining protocols were developed for automated quantitative analysis (AQUA) using antibodies vs LC3 isoform B (LC3B) and Ki-67. Clinically annotated breast and melanoma TMA’s and a multitumor array were employed. An AQUA program was developed to quantitate LC3B distribution in punctate and diffuse compartments of the cell. Results LC3B staining was moderate to high in the large majority of tumors. The % area occupied by punctate LC3B was elevated 3–5 fold at high LC3B intensities. In breast cancer and melanoma TMAs, LC3B and Ki-67 showed strong correlations (p < 0.0001) and in multitumor TMAs mitotic figures were most often seen in tumors with highest LC3B expression (p < 0.002). In breast cancer, LC3B expression was elevated in node-positive vs node-negative primaries and associated with increased nuclear grade and shortened survival. In a melanoma TMA with no survival data, LC3B levels were highest in nodal, visceral and cutaneous metastases. Conclusions The results reveal a common expression of LC3B in malignancy and support emerging evidence that autophagy plays a significant role in cancer progression. High LC3B was associated proliferation, invasion and metastasis, high nuclear grade and worse outcome. Thus autophagy presents a key target of therapeutic vulnerability in solid tumors. PMID:22080440

  15. Patterned charring along the contact points of a metallic locket due to lightning strike.

    PubMed

    Adil, Md Tanveer; Rahman, Rumana; Das, Soumen

    2016-06-01

    Superficial cutaneous burns following lightning strike may vary in patterns ranging from linear burns, punctate burns, feathering burns, and thermal burns. Contact with an extrinsic object in the pathway of lightning current can lead to disastrous consequences. The lucky who survive may show bizarre and interesting burn patterns to tell their story. PMID:27398211

  16. Patterned charring along the contact points of a metallic locket due to lightning strike.

    PubMed

    Adil, Md Tanveer; Rahman, Rumana; Das, Soumen

    2016-06-01

    Superficial cutaneous burns following lightning strike may vary in patterns ranging from linear burns, punctate burns, feathering burns, and thermal burns. Contact with an extrinsic object in the pathway of lightning current can lead to disastrous consequences. The lucky who survive may show bizarre and interesting burn patterns to tell their story.

  17. Patterns of Broken Patterns

    NASA Astrophysics Data System (ADS)

    Field, R. W.; Park, G. B.; Changala, P. B.; Baraban, J. H.; Stanton, J. F.; Merer, A. J.

    2013-06-01

    Spectroscopy - it is all about patterns. Some patterns look so indescribably complicated that, unlike pornography, you do not know one when you see one. It is tempting to say that, at high vibrational excitation, interactions among normal mode basis states are so strong and widespread that all patterns are obliterated. But this is not true. When normal mode frequencies are in near integer multiple ratios, polyads emerge. A polyad is a robust pattern often comprising many vibrational eigenstates. Each such pattern might span many hundreds of cm^{-1}, and it is inevitable that several unrelated polyad patterns overlap. When polyads overlap, it might seem impossible to disentangle them. However, the key to disentanglement is that polyads come in families in which successive generations are related by harmonic oscillator matrix element selection and scaling rules. Families of polyads are described by families of scaling-based effective Hamiltonian matrices, {H}^{{eff}}. No matter how complex and overlapped, the polyad {H}^{{eff}} serves as a magic decoder for picking out the polyad pattern. Sometimes the polyad patterns are systematically broken (a meta-pattern), owing to proximity to an isomerization barrier, as occurs in highly excited bending levels of the S_{1} state of HCCH, which encode the trans-cis minimum energy isomerization path. Quantum Chemists often dismiss {H}^{{eff}} models, precisely because they are models that do not express the full dimensionality of the complete Hamiltonian. But an {H}^{{eff}} explains rather than describes. Shunning {H}^{{eff}}s is like throwing out the baby with the bath water. Don't do it!

  18. Marangoni patterns

    NASA Astrophysics Data System (ADS)

    Thyagu, N. Nirmal; Strombom, Evelyn; Palumbo, Daniel; Caicedo, Carlos; Shinbrot, Troy

    2010-11-01

    We study Marangoni patterns that emerge when common food dye is dropped into a dish of shallow water. These patterns consist of tendrils and spots that sharpen over time before eventually fading. We demonstrate that the patterns can be modeled using coupled reaction-diffusion equations, where the "reaction" terms appear due to a nonlinear dependence of surface tension on dye concentration. We show using a spatio-temporal metric that these patterns are distinct from previously described Turing patterns.

  19. Foam patterns

    DOEpatents

    Chaudhry, Anil R; Dzugan, Robert; Harrington, Richard M; Neece, Faurice D; Singh, Nipendra P; Westendorf, Travis

    2013-11-26

    A method of creating a foam pattern comprises mixing a polyol component and an isocyanate component to form a liquid mixture. The method further comprises placing a temporary core having a shape corresponding to a desired internal feature in a cavity of a mold and inserting the mixture into the cavity of the mold so that the mixture surrounds a portion of the temporary core. The method optionally further comprises using supporting pins made of foam to support the core in the mold cavity, with such pins becoming integral part of the pattern material simplifying subsequent processing. The method further comprises waiting for a predetermined time sufficient for a reaction from the mixture to form a foam pattern structure corresponding to the cavity of the mold, wherein the foam pattern structure encloses a portion of the temporary core and removing the temporary core from the pattern independent of chemical leaching.

  20. Pattern Formation

    NASA Astrophysics Data System (ADS)

    Hoyle, Rebecca

    2006-03-01

    From the stripes of a zebra and the spots on a leopard's back to the ripples on a sandy beach or desert dune, regular patterns arise everywhere in nature. The appearance and evolution of these phenomena has been a focus of recent research activity across several disciplines. This book provides an introduction to the range of mathematical theory and methods used to analyse and explain these often intricate and beautiful patterns. Bringing together several different approaches, from group theoretic methods to envelope equations and theory of patterns in large-aspect ratio-systems, the book also provides insight behind the selection of one pattern over another. Suitable as an upper-undergraduate textbook for mathematics students or as a fascinating, engaging, and fully illustrated resource for readers in physics and biology, Rebecca Hoyle's book, using a non-partisan approach, unifies a range of techniques used by active researchers in this growing field. Accessible description of the mathematical theory behind fascinating pattern formation in areas such as biology, physics and materials science Collects recent research for the first time in an upper level textbook Features a number of exercises - with solutions online - and worked examples

  1. Classification of abnormal fundus autofluorescence patterns in the junctional zone of geographic atrophy in patients with age related macular degeneration

    PubMed Central

    Bindewald, A; Schmitz-Valckenberg, S; Jorzik, J J; Dolar-Szczasny, J; Sieber, H; Keilhauer, C; Weinberger, A W A; Dithmar, S; Pauleikhoff, D; Mansmann, U; Wolf, S; Holz, F G

    2005-01-01

    Aim: To describe and classify patterns of abnormal fundus autofluorescence (FAF) in the junctional zone of geographic atrophy (GA) in patients with age related macular degeneration. Methods: Digital FAF images were recorded in 164 eyes of 107 patients using a confocal scanning laser ophthalmoscope (cSLO; excitation 488 nm, detection above 500 nm) as part of a prospective multicentre natural history study (FAM Study). FAF images were obtained in accordance with a standardised protocol for digital image acquisition and generation of mean images after automated alignment. Results: Image quality was sufficient for classification of FAF patterns in 149 eyes (90.9%) with lens opacities being the most common reason for insufficient image quality. Abnormal FAF outside GA in 149 eyes was classified into four patterns: focal (12.1%), banded (12.8%), patchy (2.0%), and diffuse (57.0%), whereby 12.1% had normal background FAF in the junctional zone. In 4% there was no predominant pattern. The diffuse pattern was subdivided into four groups including reticular (4.7%), branching (27.5%), fine granular (18.1%), and fine granular with peripheral punctate spots (6.7%). Conclusions: Different phenotypic patterns of abnormal FAF in the junctional zone of GA can be identified with cSLO FAF imaging. These distinct patterns may reflect heterogeneity at a cellular and molecular level in contrast with a non-specific ageing process. A refined phenotypic classification may be helpful to identify prognostic determinants for the spread of atrophy and visual loss, for identification of genetic risk factors as well as for the design of future interventional trials. PMID:15965170

  2. An imidazole functionalized pentameric thiophene displays different staining patterns in normal and malignant cells

    PubMed Central

    Magnusson, Karin; Appelqvist, Hanna; Cieślar-Pobuda, Artur; Bäck, Marcus; Kågedal, Bertil; Jonasson, Jon A.; Los, Marek J.; Nilsson, K. Peter R.

    2015-01-01

    Molecular tools for fluorescent imaging of cells and their components are vital for understanding the function and activity of cells. Here, we report an imidazole functionalized pentameric oligothiophene, p-HTIm, that can be utilized for fluorescent imaging of cells. p-HTIm fluorescence in normal cells appeared in a peripheral punctate pattern partially co-localized with lysosomes, whereas a one-sided perinuclear Golgi associated localization of the dye was observed in malignant cells. The uptake of p-HTIm was temperature dependent and the intracellular target was reached within 1 h after staining. The ability of p-HTIm to stain cells was reduced when the imidazole side chain was chemically altered, verifying that specific imidazole side-chain functionalities are necessary for achieving the observed cellular staining. Our findings confirm that properly functionalized oligothiophenes can be utilized as fluorescent tools for vital staining of cells and that the selectivity toward distinct intracellular targets are highly dependent on the side-chain functionalities along the conjugated thiophene backbone. PMID:26501054

  3. Identification and punctate nuclear localization of a novel noncoding RNA, Ks-1, from the honeybee brain.

    PubMed Central

    Sawata, Miyuki; Yoshino, Daisuke; Takeuchi, Hideaki; Kamikouchi, Azusa; Ohashi, Kazuaki; Kubo, Takeo

    2002-01-01

    We identified a novel gene, Ks-1, which is expressed preferentially in the small-type Kenyon cells of the honeybee brain. This gene is also expressed in some of the large soma neurons in the brain and in the suboesophageal ganglion. Reverse transcription-polymerase chain reaction experiments indicated that Ks-1 transcripts are enriched in the honeybee brain. cDNA cloning revealed that the consensus Ks-1 cDNA is over 17 kbp and contains no significant open reading frames. Furthermore, fluorescent in situ hybridization revealed that Ks-1 transcripts are located in the nuclei of the neural cells, accumulating in some scattered spots. These findings demonstrate that Ks-1 encodes a novel class of noncoding nuclear RNA and is possibly involved in the regulation of neural functions. PMID:12088150

  4. Pattern Formation without Patterning Proteins in Cyanobacteria

    NASA Astrophysics Data System (ADS)

    Allard, Jun; Rutenberg, Andrew

    2006-03-01

    Filaments of cyanobacteria respond to nitrogen starvation by differentiating one cell in ten into a heterocyst, which is devoted to fixing atmospheric nitrogen. This is an example of self-organized pattern formation. We present a dynamical model explaining the initial selection of heterocysts in mutated cyanobacteria that are effectively without normal patterning proteins. Our simulations of this model produce distributions of heterocyst spacings that are consistent with experimental data, and lead to new qualitative predictions on the mechanisms of pattern formation in filamentous cyanobacteria. We discuss possible experimental tests of our results.

  5. Pattern recognition technique

    NASA Technical Reports Server (NTRS)

    Hong, J. P.

    1971-01-01

    Technique operates regardless of pattern rotation, translation or magnification and successfully detects out-of-register patterns. It improves accuracy and reduces cost of various optical character recognition devices and page readers and provides data input to computer.

  6. Formalising Interaction Patterns

    NASA Astrophysics Data System (ADS)

    Bottoni, Paolo; Guerra, Esther; de Lara, Juan

    The use of patterns as a way to refer to common solutions in the field of interface design is becoming widespread. However, contrary to the situation for software patterns, definitions of interaction patterns do not enjoy a common standard yet. Moreover, patterns are developed for design aspects as diverse as: user experience, layout, action coordination, or specification of entire widgets, reflecting the complexity of the field. As a consequence, research on formalisation of interaction patterns is not developed, and few attempts have been made to extend techniques developed for design pattern formalisation. We show here how an extension to an approach to pattern formalisation recently proposed by the authors can be usefully employed to formalize some classes of interaction patterns, to express relations like subtyping and composition, and to detect conflicts.

  7. Male pattern baldness (image)

    MedlinePlus

    Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than by looking ...

  8. Mathematical Pattern Hunters

    ERIC Educational Resources Information Center

    Whitin, Phyllis; Whitin, David J.

    2011-01-01

    The habit of looking for patterns, the skills to find them, and the expectation that patterns have explanations is an essential mathematical habit of mind for young children (Goldenberg, Shteingold, & Feurzeig 2003, 23). Work with patterns leads to the ability to form generalizations, the bedrock of algebraic thinking, and teachers must nurture…

  9. Ramadan Major Dietary Patterns

    PubMed Central

    Shadman, Zhaleh; Poorsoltan, Nooshin; Akhoundan, Mahdieh; Larijani, Bagher; Soleymanzadeh, Mozhdeh; Akhgar Zhand, Camelia; Seyed Rohani, Zahra Alsadat; Khoshniat Nikoo, Mohsen

    2014-01-01

    Background: There has been no data on population based dietary patterns during the Ramadan fasting month. Objectives: The purpose of this study was to detect Ramadan major dietary patterns among those who fast in Tehran. Materials and Methods: This cross-sectional study included 600 subjects, aged 18-65 with body mass index (BMI) of 18.5-40, who had decided to fast during Ramadan. Anthropometric measurements, usual physical activity level and educational status were collected two weeks before Ramadan. Information on Ramadan dietary intakes was obtained using a food frequency questionnaire and factor analysis was used to identify major dietary patterns. Results: We identified four major dietary patterns: 1) Western-like pattern; high in fast foods, salty snacks, nuts, potato, fish, poultry, chocolates, juices; 2) high cholesterol and high sweet junk food pattern; high in pickles, sweets and condiments, butter and cream, canned fish, visceral meats and eggs; 3) Mediterranean-like pattern; high in vegetables, olive oil, dates, dairy, dried fruits, fruits, red meats, tea and coffee and 4) Ramadan-style pattern; large consumption of Halim, soups, porridges, legumes and whole grains, soft drinks, Zoolbia and Bamieh. Age was positively and inversely associated with Mediterranean-like (P = 0.003; r = 0.17) and Ramadan style (P = 0.1; r = -0.13) dietary pattern, respectively. Pre-Ramadan physical activity level was associated with a Mediterranean-like dietary pattern (P < 0.0001; r = 0.20). Conclusions: This study showed a Ramadan-specific dietary pattern has unique characteristics, which has not yet been identified as a model of dietary pattern. Also, among identified dietary patterns, Mediterranean-like was the healthiest. PMID:25593728

  10. Characterizations of natural patterns

    NASA Astrophysics Data System (ADS)

    Gunaratne, Gemunu H.; Hoffman, David K.; Kouri, Donald J.

    1998-05-01

    Labyrinthine patterns are observed in systems as diverse as animal coats, slime mold colonies, fish scales, and cloud streets. However, even under well-controlled conditions, repetition of an experiment gives structures with vastly different details. A theoretical analysis of ``universal'' aspects of patterns requires a quantitative description that gives similar values for distinct configurations. We introduce a function to characterize the ``disorder'' of labyrinthine patterns that is the same for structures generated under identical control parameters. Furthermore, patterns with different visual characteristics are described by distinct functions.

  11. Chemically functionalized surface patterning.

    PubMed

    Zhou, Xiaozhu; Boey, Freddy; Huo, Fengwei; Huang, Ling; Zhang, Hua

    2011-08-22

    Patterning substrates with versatile chemical functionalities from micro- to nanometer scale is a long-standing and interesting topic. This review provides an overview of a range of techniques commonly used for surface patterning. The first section briefly introduces conventional micropatterning tools, such as photolithography and microcontact printing. The second section focuses on the currently used nanolithographic techniques, for example, scanning probe lithography (SPL), and their applications in surface patterning. Their advantages and disadvantages are also demonstrated. In the last section, dip-pen nanolithography (DPN) is emphatically illustrated, with a particular stress on the patterning and applications of biomolecules.

  12. Female-pattern baldness (image)

    MedlinePlus

    Female-pattern baldness is a pattern of hair loss (alopecia) caused by hormones, aging and genetics. Unlike male-pattern baldness, female-pattern baldness is an over-all thinning which maintains the normal ...

  13. Biologic Patterns of Disability.

    ERIC Educational Resources Information Center

    Granger, Carl V.; Linn, Richard T.

    2000-01-01

    Describes the use of Rasch analysis to elucidate biological patterns of disability present in the functional ability of persons undergoing medical rehabilitation. Uses two measures, one for inpatients and one for outpatients, to illustrate the approach and provides examples of some biological patterns of disability associated with specific types…

  14. Engaging with Islamic Patterns

    ERIC Educational Resources Information Center

    Sugarman, Ian

    2012-01-01

    Islamic patterns were a regular feature in mathematics classrooms, and probably still feature in many wall displays. However, as part of the learning process, these ancient designs appear to have lost any significant contemporary appeal. Here, the power of software is engaged to bring the construction of Islamic type patterns up to date. Forget…

  15. Patterns in Multiples.

    ERIC Educational Resources Information Center

    Robold, Alice I.

    1982-01-01

    Activities that allow students to represent patterns concretely before showing the patterns in color on paper are presented. Three basic activities are described, with suggestions made for extensions that allow further pupil exploration of multiples. Student discovery of relationships not found by the teacher is expected. (MP)

  16. Patterned Personality Portraits

    ERIC Educational Resources Information Center

    Surrena, Michelle Flandera

    2008-01-01

    In this article, the author describes a self-portrait project she developed for her students. The project emphasizes personality and pattern as the main objectives through a series of steps that include drawing exercises, observation skills, stream-of-color, intense patterning and texturizing, and colored pencil techniques. By drawing down the…

  17. Is It a Pattern?

    ERIC Educational Resources Information Center

    McGarvey, Lynn M.

    2013-01-01

    This article describes how in early mathematics learning, young children are often asked to recognize and describe visual patterns in their environment--perhaps on their clothing, a toy, or the carpet; around a picture frame; or in the playground equipment. Exploring patterns in the early years is seen as an important introduction to algebraic…

  18. Choreographing Patterns and Functions

    ERIC Educational Resources Information Center

    Hawes, Zachary; Moss, Joan; Finch, Heather; Katz, Jacques

    2012-01-01

    In this article, the authors begin with a description of an algebraic dance--the translation of composite linear growing patterns into choreographed movement--which was the last component of a research-based instructional unit that focused on fostering an understanding of linear functional rules through geometric growing patterns and…

  19. Places with Patterns

    ERIC Educational Resources Information Center

    Bachman, Julie

    2004-01-01

    Matisse's use of bright colors and strong pattern is an instant motivator for elementary students. He effectively balances colors and simple shapes. This lesson, designed for 3rd graders, is an example of how art studio experiences for young students can draw upon art history. Sections include: (1) Discovering Patterns; (2) Planning Special…

  20. Airborne antenna pattern calculations

    NASA Technical Reports Server (NTRS)

    Bagherian, A. B.; Mielke, R. R.

    1983-01-01

    Use of calculation program START and modeling program P 3D to produce radiation patterns of antennas mounted on a space station is discussed. Basic components of two space stations in the early design stage are simulated and radiation patterns for antennas mounted on the modules are presented.

  1. Solar cell grid patterns

    NASA Technical Reports Server (NTRS)

    Yasui, R. K.; Berman, P. A. (Inventor)

    1976-01-01

    A grid pattern is described for a solar cell of the type which includes a semiconductive layer doped to a first polarity and a top counter-doped layer. The grid pattern comprises a plurality of concentric conductive grids of selected geometric shapes which are centered about the center of the exposed active surface of the counter-doped layer. Connected to the grids is one or more conductors which extend to the cell's periphery. For the pattern area, the grids and conductors are arranged in the pattern to minimize the maximum distance which any injected majority carriers have to travel to reach any of the grids or conductors. The pattern has a multiaxes symmetry with respect to the cell center to minimize the maximum temperature differentials between points on the cell surface and to provide a more uniform temperature distribution across the cell face.

  2. Active element pattern

    NASA Astrophysics Data System (ADS)

    Pozar, D. M.

    1994-08-01

    This review article will discuss the use of the active element pattern for prediction of the scan performance of large phased array antennas. The introduction and application of the concept of the active element pattern goes back at least 30 years (1) -(6) , but the subject is generally not covered in modern antenna engineering textbooks or handbooks, and many contemporary workers are unfamiliar with this simple but powerful idea. In addition, early references on this subject do not provide a rigorous discussion or derivation of the active element pattern, relying instead on a more qualitative interpretation. The purpose of this communication is to make the technique of active element patterns more accessible to antenna engineers, and to provide a new derivation of the basic active element pattern relations in terms of scattering parameters.

  3. Patterns from drying drops.

    PubMed

    Sefiane, Khellil

    2014-04-01

    The objective of this review is to investigate different deposition patterns from dried droplets of a range of fluids: paints, polymers and biological fluids. This includes looking at mechanisms controlling the patterns and how they can be manipulated for use in certain applications such as medical diagnostics and nanotechnology. This review introduces the fundamental properties of droplets during evaporation. These include profile evolution (constant contact angle regime (CCAR) and constant radius regime (CRR)) and the internal flow (Marangoni and Capillary flow (Deegan et al. [22])). The understanding of these processes and the basic physics behind the phenomenon are crucial to the understanding of the factors influencing the deposition patterns. It concludes with the applications that each of these fluids can be used in and how the manipulation of the deposition pattern is useful. The most commonly seen pattern is the coffee-ring deposit which can be seen frequently in real life from tea/coffee stains and in water colour painting. This is caused by an outward flow known as capillary flow which carries suspended particles out to the edge of the wetted area. Other patterns that were found were uniform, central deposits and concentric rings which are caused by inward Marangoni flow. Complex biological fluids displayed an array of different patterns which can be used to diagnose patients.

  4. Patterns from drying drops.

    PubMed

    Sefiane, Khellil

    2014-04-01

    The objective of this review is to investigate different deposition patterns from dried droplets of a range of fluids: paints, polymers and biological fluids. This includes looking at mechanisms controlling the patterns and how they can be manipulated for use in certain applications such as medical diagnostics and nanotechnology. This review introduces the fundamental properties of droplets during evaporation. These include profile evolution (constant contact angle regime (CCAR) and constant radius regime (CRR)) and the internal flow (Marangoni and Capillary flow (Deegan et al. [22])). The understanding of these processes and the basic physics behind the phenomenon are crucial to the understanding of the factors influencing the deposition patterns. It concludes with the applications that each of these fluids can be used in and how the manipulation of the deposition pattern is useful. The most commonly seen pattern is the coffee-ring deposit which can be seen frequently in real life from tea/coffee stains and in water colour painting. This is caused by an outward flow known as capillary flow which carries suspended particles out to the edge of the wetted area. Other patterns that were found were uniform, central deposits and concentric rings which are caused by inward Marangoni flow. Complex biological fluids displayed an array of different patterns which can be used to diagnose patients. PMID:23746427

  5. Patterns of gender development.

    PubMed

    Martin, Carol Lynn; Ruble, Diane N

    2010-01-01

    A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains-sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development.

  6. Multiscale conformal pattern transfer.

    PubMed

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-01-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics. PMID:27329824

  7. Multiscale conformal pattern transfer

    PubMed Central

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-01-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics. PMID:27329824

  8. Patterns of Gender Development

    PubMed Central

    Martin, Carol Lynn; Ruble, Diane N.

    2013-01-01

    A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains—sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development. PMID:19575615

  9. Multiscale conformal pattern transfer

    NASA Astrophysics Data System (ADS)

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-06-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics.

  10. Female Pattern Alopecia

    MedlinePlus

    ... or cyproterone acetate (not available in the US). Finasteride, also an oral medication, is approved for male ... show no effect for female pattern hair loss. Finasteride, spironolactone, and cyproterone should not be used in ...

  11. Pattern formation today

    PubMed Central

    Chuong, Cheng-Ming; Richardson, Michael K.

    2010-01-01

    Patterns are orders embedded in randomness. They may appear as spatial arrangements or temporal series, and the elements may appear identical or with variations. Patterns exist in the physical world as well as in living systems. In the biological world, patterns can range from simple to complex, forming the basic building blocks of life. The process which generates this ordering in the biological world was termed pattern formation. Since Wolpert promoted this concept four decades ago, scientists from molecular biology, developmental biology, stem cell biology, tissue engineering, theoretical modeling and other disciplines have made remarkable progress towards understanding its mechanisms. It is time to review and re-integrate our understanding. Here, we explore the origin of pattern formation, how the genetic code is translated into biological form, and how complex phenotypes are selected over evolutionary time. We present four topics: Principles, Evolution, Development, and Stem Cells and Regeneration. We have interviewed several leaders in the field to gain insight into how their research and the field of pattern formation have shaped each other. We have learned that both molecular process and physico-chemical principles are important for biological pattern formation. New understanding will emerge through integration of the analytical approach of molecular-genetic manipulation and the systemic approach of model simulation. We regret that we could not include every major investigator in the field, but hope that this Special Issue of the Int. J. Dev. Biol. represents a sample of our knowledge of pattern formation today, which will help to stimulate more research on this fundamental process. PMID:19557673

  12. MSU Antenna Pattern Data

    NASA Technical Reports Server (NTRS)

    Mo, Tsan; Kleespies, Thomas J.; Green, J. Philip

    2000-01-01

    The Microwave Sounding Unit (MSU) antenna pattern data for nine MSU Flight Models (FMs) have been successfully rescued from 22-year old 7-track and 9-track magnetic tapes and cartridges. These antenna pattern data were unpacked into user-friendly ASCII format, and are potentially useful for making antenna pattern corrections to MSU antenna temperatures in retrieving the true brightness temperatures. We also properly interpreted the contents of the data and show how to convert the measured antenna signal amplitude in volts into relative antenna power in dB with proper normalization. It is found that the data are of high quality with a 60-dB drop in the co-polarized antenna patterns from the central peak value to its side-lobe regions at scan angles beyond 30 deg. The unpacked antenna pattern data produced in this study provide a useful database for data users to correct the antenna side-lobe contribution to MSU measurements. All of the data are available to the scientific community on a single CD-ROM.

  13. Intensity patterns in eastern Asia.

    USGS Publications Warehouse

    Evernden, J.F.

    1983-01-01

    Investigation of the intensity patterns of earthquakes of E Asia indicates a strong regional pattern of attenuation parameter k and systematic correlation of this pattern with topography, P residuals, and level of seismicity as in the USA.-Author

  14. Female pattern hair loss.

    PubMed

    Ioannides, Dimitrios; Lazaridou, Elizabeth

    2015-01-01

    Female pattern hair loss, or female pattern androgenetic alopecia, is a nonscarring alopecia with a multi-factorial etiology that mostly affects postmenopausal women and is characterized by a reduction in hair density over the crown and frontal scalp. The clinical picture is characterized by a diffuse rarefaction of scalp hair over the mid-frontal scalp and a more-or-less intact frontal hairline without any signs of inflammation or scarring. Although the disease poses only a cosmetic concern, it is chronic and may have a significant negative psychological impact on the affected person. The aim of treating female pattern hair loss is to reduce hair loss and, to a certain extent, succeed in promoting hair regrowth. Various treatment methods are available, but it remains unclear which are the most effective. Early initiation of treatment and the combination of various modalities seem to be more efficacious than monotherapy. PMID:26370643

  15. Design Patterns - Past, Present & Future

    NASA Astrophysics Data System (ADS)

    Gamma, Erich

    Design Patterns are now a 15 year old thought experiment. And today, for many, Design Patterns have become part of the standard development lexicon. This talk looks back to the origin of Design Patterns and how they evolved since their initial description. I will then show patterns in action in the context of the Eclipse and Jazz platforms. Finally, I will discuss how the Design Patterns from the book can be refactored towards a Design Pattern 2.0 version.

  16. Diapiric spoke patterns

    NASA Astrophysics Data System (ADS)

    Talbot, C. J.; Rönnlund, P.; Schmeling, H.; Koyi, H.; Jackson, M. P. A.

    1991-03-01

    Not all finger-like diapirs evolve from or into linear walls as previously supposed. That would imply that all contemporaneous finger diapirs lie in rows and many do not. Physical models demonstrate that diapiric linear walls or rows of fingers have to be forced by lateral forces, lateral boundaries, or internal edge effects. By contrast, the kinematics of the simplest isothermal gravity overturns responsible for finger-like diapirs are geometrically, kinematically and dynamically similar to the "spoke patterns" of vigorous thermal convection. This is because Rayleigh-Taylor (RT) diapirism and Rayleigh-Bènard (RB) thermal convection are end members of a continuous dynamic spectrum due to any combination of compositional or thermally induced density inversions. All simple RT overturns are dynamically similar, but the vigour of thermal convection varies with the heat flow. The kinematics of spoke patterns are difficult to study in rapid, multiple overturns of thermal convection in low viscosity fluids. However, spoke patterns in slow, isothermal diapiric analogues can be analysed at any stage during their single overturn. Such studies indicate that two sets of spokes conduct fluids of different densities horizontally along the top and bottom boundaries to finger-like diapiric stems or plumes where they rise or sink to spread in polygonal bulbs at the opposite boundary. Spokes converge to hubs at the bottom boundary beneath stems feeding diapiric bulbs at the top boundary and vice versa. If the movement cells are considered centred on rising plumes, the cell corners are mapped by sinking plumes. The differences between spoke patterns and previously understood diapiric patterns are illustrated by geological examples with emphasis on relevance to the search for oil and gas. Physical arguments suggest that spoke patterns are probably the most common geometries of gravity-driven overturns in layered rocks of both the crust and the mantle.

  17. Design friendly double patterning

    NASA Astrophysics Data System (ADS)

    Yesilada, Emek

    2012-03-01

    Double patterning using 193nm immersion has been adapted as the solution to enable 2x nm technology nodes until the arrival of EUV tools. As a result the past few years have seen a huge effort in creating double patterning friendly design flows. These flows have so far proposed a combination of decomposition rules at cell level and/or at placement level as well as sophisticated decomposition tools with varying density, design iteration and decomposition complexity penalties. What is more, designers have to familiarize themselves with double patterning challenges and decomposition tools. In this paper an alternative approach is presented that allows the development of dense standard cells with minimal impact on design flow due to double patterning. A real case study is done on 20nm node first metal layer where standard cells are designed without considering decomposition restrictions. The resulting layout is carefully studied in order to establish decomposition or color rules that can map the layout into two masks required for double patterning but without the need of complex coloring algorithms. Since the rules are derived from a decomposition unaware design they do not in return impose heavy restrictions on the design at the cell or placement level and show substantial density gains compared to previously proposed methods. Other key advantages are a simplified design flow without complex decomposition tools that can generate a faster time to market solution all at the same time keeping designers isolated from the challenges of the double patterning. The derived design rules highlight process development path required for design driven manufacturing.

  18. Calculating cellulose diffraction patterns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although powder diffraction of cellulose is a common experiment, the patterns are not widely understood. The theory is mathematical, there are numerous different crystal forms, and the conventions are not standardized. Experience with IR spectroscopy is not directly transferable. An awful error, tha...

  19. Turing Patterns Inside Cells

    PubMed Central

    Strier, Damián E.; Ponce Dawson, Silvina

    2007-01-01

    Concentration gradients inside cells are involved in key processes such as cell division and morphogenesis. Here we show that a model of the enzymatic step catalized by phosphofructokinase (PFK), a step which is responsible for the appearance of homogeneous oscillations in the glycolytic pathway, displays Turing patterns with an intrinsic length-scale that is smaller than a typical cell size. All the parameter values are fully consistent with classic experiments on glycolytic oscillations and equal diffusion coefficients are assumed for ATP and ADP. We identify the enzyme concentration and the glycolytic flux as the possible regulators of the pattern. To the best of our knowledge, this is the first closed example of Turing pattern formation in a model of a vital step of the cell metabolism, with a built-in mechanism for changing the diffusion length of the reactants, and with parameter values that are compatible with experiments. Turing patterns inside cells could provide a check-point that combines mechanical and biochemical information to trigger events during the cell division process. PMID:17940616

  20. Understanding taxi travel patterns

    NASA Astrophysics Data System (ADS)

    Cai, Hua; Zhan, Xiaowei; Zhu, Ji; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

    2016-09-01

    Taxis play important roles in modern urban transportation systems, especially in mega cities. While providing necessary amenities, taxis also significantly contribute to traffic congestion, urban energy consumption, and air pollution. Understanding the travel patterns of taxis is thus important for addressing many urban sustainability challenges. Previous research has primarily focused on examining the statistical properties of passenger trips, which include only taxi trips occupied with passengers. However, unoccupied trips are also important for urban sustainability issues because they represent potential opportunities to improve the efficiency of the transportation system. Therefore, we need to understand the travel patterns of taxis as an integrated system, instead of focusing only on the occupied trips. In this study we examine GPS trajectory data of 11,880 taxis in Beijing, China for a period of three weeks. Our results show that taxi travel patterns share similar traits with travel patterns of individuals but also exhibit differences. Trip displacement distribution of taxi travels is statistically greater than the exponential distribution and smaller than the truncated power-law distribution. The distribution of short trips (less than 30 miles) can be best fitted with power-law while long trips follow exponential decay. We use radius of gyration to characterize individual taxi's travel distance and find that it does not follow a truncated power-law as observed in previous studies. Spatial and temporal regularities exist in taxi travels. However, with increasing spatial coverage, taxi trips can exhibit dual high probability density centers.

  1. Experiments with Patterns

    ERIC Educational Resources Information Center

    de Mestre, Neville

    2008-01-01

    This article presents a hands-on experiment that covers many areas of high school mathematics. Included are the notions of patterns, proof, triangular numbers and various aspects of problem solving. The problem involves the arrangements of a school of fish using split peas or buttons to represent the fish. (Contains 4 figures.)

  2. Reconfigurable antenna pattern verification

    NASA Technical Reports Server (NTRS)

    Drexler, Jerome P. (Inventor); Becker, Robert C. (Inventor); Meyers, David W. (Inventor); Muldoon, Kelly P. (Inventor)

    2013-01-01

    A method of verifying programmable antenna configurations is disclosed. The method comprises selecting a desired antenna configuration from a plurality of antenna configuration patterns, with the selected antenna configuration forming at least one reconfigurable antenna from reconfigurable antenna array elements. The method validates the formation of the selected antenna configuration to determine antenna performance of the at least one reconfigurable antenna.

  3. Nutritional Patterns of Centenarians.

    ERIC Educational Resources Information Center

    Johnson, Mary Ann; And Others

    1992-01-01

    Compared dietary patterns of 165 older adults. Compared to younger cohorts, centenarians (n=24) consumed breakfast more regularly, avoided weight loss diets and large fluctuation in body weight, consumed slightly more vegetables, and relied on doctors and family for nutrition information. Centenarians were less likely to consume low-fat diets and…

  4. Bumblebees Learn Polarization Patterns

    PubMed Central

    Foster, James J.; Sharkey, Camilla R.; Gaworska, Alicia V.A.; Roberts, Nicholas W.; Whitney, Heather M.; Partridge, Julian C.

    2014-01-01

    Summary Foraging insect pollinators such as bees must find and identify flowers in a complex visual environment. Bees use skylight polarization patterns for navigation [1–3], a capacity mediated by the polarization-sensitive dorsal rim area (DRA) of their eye [4, 5]. While other insects use polarization sensitivity to identify appropriate habitats [6], oviposition sites, and food sources [7], to date no nonnavigational functions of polarization vision have been identified in bees. Here we investigated the ability of bumblebees (Bombus terrestris) to learn polarization patterns on artificial “flowers” in order to obtain a food reward. We show that foraging bumblebees can learn to discriminate between two differently polarized targets, but only when the target artificial “flower” is viewed from below. A context for these results is provided by polarization imaging of bee-pollinated flowers, revealing the potential for polarization patterns in real flowers. Bees may therefore have the ability to use polarization vision, possibly mediated by their polarization-sensitive DRA, both for navigation and to learn polarization patterns on flowers, the latter being the first nonnavigational function for bee polarization vision to be identified. PMID:24909321

  5. A Passion for Pattern

    ERIC Educational Resources Information Center

    Venola, Penelope

    2012-01-01

    Popular culture is a relatively new area of study in the artroom, and combining it with the demands of a rigorous curriculum requires some thought. Combining threads from several sources was the key to an exciting exploration of pattern inspired by a newspaper headline. In 2006, a landmark case was settled in Austria, which repatriated five famous…

  6. Patterning of somatosympathetic reflexes

    NASA Technical Reports Server (NTRS)

    Kerman, I. A.; Yates, B. J.

    1999-01-01

    In a previous study, we reported that vestibular nerve stimulation in the cat elicits a specific pattern of sympathetic nerve activation, such that responses are particularly large in the renal nerve. This patterning of vestibulosympathetic reflexes was the same in anesthetized and decerebrate preparations. In the present study, we report that inputs from skin and muscle also elicit a specific patterning of sympathetic outflow, which is distinct from that produced by vestibular stimulation. Renal, superior mesenteric, and lumbar colonic nerves respond most strongly to forelimb and hindlimb nerve stimulation (approximately 60% of maximal nerve activation), whereas external carotid and hypogastric nerves were least sensitive to these inputs (approximately 20% of maximal nerve activation). In contrast to vestibulosympathetic reflexes, the expression of responses to skin and muscle afferent activation differs in decerebrate and anesthetized animals. In baroreceptor-intact animals, somatosympathetic responses were strongly attenuated (to <20% of control in every nerve) by increasing blood pressure levels to >150 mmHg. These findings demonstrate that different types of somatic inputs elicit specific patterns of sympathetic nerve activation, presumably generated through distinct neural circuits.

  7. Computational Thinking Patterns

    ERIC Educational Resources Information Center

    Ioannidou, Andri; Bennett, Vicki; Repenning, Alexander; Koh, Kyu Han; Basawapatna, Ashok

    2011-01-01

    The iDREAMS project aims to reinvent Computer Science education in K-12 schools, by using game design and computational science for motivating and educating students through an approach we call Scalable Game Design, starting at the middle school level. In this paper we discuss the use of Computational Thinking Patterns as the basis for our…

  8. Spider Web Pattern

    NASA Technical Reports Server (NTRS)

    2006-01-01

    A delicate pattern, like that of a spider web, appears on top of the Mars residual polar cap, after the seasonal carbon-dioxide ice slab has disappeared. Next spring, these will likely mark the sites of vents when the carbon-dioxide ice cap returns. This Mars Global Surveyor, Mars Orbiter Camera image is about 3-kilometers wide (2-miles).

  9. Optimal ciliary beating patterns

    NASA Astrophysics Data System (ADS)

    Vilfan, Andrej; Osterman, Natan

    2011-11-01

    We introduce a measure for energetic efficiency of single or collective biological cilia. We define the efficiency of a single cilium as Q2 / P , where Q is the volume flow rate of the pumped fluid and P is the dissipated power. For ciliary arrays, we define it as (ρQ) 2 / (ρP) , with ρ denoting the surface density of cilia. We then numerically determine the optimal beating patterns according to this criterion. For a single cilium optimization leads to curly, somewhat counterintuitive patterns. But when looking at a densely ciliated surface, the optimal patterns become remarkably similar to what is observed in microorganisms like Paramecium. The optimal beating pattern then consists of a fast effective stroke and a slow sweeping recovery stroke. Metachronal waves lead to a significantly higher efficiency than synchronous beating. Efficiency also increases with an increasing density of cilia up to the point where crowding becomes a problem. We finally relate the pumping efficiency of cilia to the swimming efficiency of a spherical microorganism and show that the experimentally estimated efficiency of Paramecium is surprisingly close to the theoretically possible optimum.

  10. Algebraic Reasoning through Patterns

    ERIC Educational Resources Information Center

    Rivera, F. D.; Becker, Joanne Rossi

    2009-01-01

    This article presents the results of a three-year study that explores students' performance on patterning tasks involving prealgebra and algebra. The findings, insights, and issues drawn from the study are intended to help teach prealgebra and algebra. In the remainder of the article, the authors take a more global view of the three-year study on…

  11. Northern Plains Patterns

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-513, 14 October 2003

    Patterns are common on the northern plains of Mars. Like their terrestrial counterparts in places like Siberia, Alaska, and northern Canada, patterned ground on Mars might be an indicator of the presence of ground ice. Whether it is true that the patterns on Mars are related to ground ice and whether the ice is still present beneath the martian surface are unknown. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows an example of patterned ground on the martian northern plains near 72.4oN, 252.6oW. The dark dots and lines are low mounds and chains of mounds. The circular feature near the center of the image is the location of a buried meteor impact crater; its presence today is marked only by the dark boulders on its rim and ejecta blanket that have managed to remain uncovered at the martian surface. The area shown is 3 km (1.9 mi) wide and illuminated by sunlight from the lower left.

  12. Pattern recognition in bioinformatics.

    PubMed

    de Ridder, Dick; de Ridder, Jeroen; Reinders, Marcel J T

    2013-09-01

    Pattern recognition is concerned with the development of systems that learn to solve a given problem using a set of example instances, each represented by a number of features. These problems include clustering, the grouping of similar instances; classification, the task of assigning a discrete label to a given instance; and dimensionality reduction, combining or selecting features to arrive at a more useful representation. The use of statistical pattern recognition algorithms in bioinformatics is pervasive. Classification and clustering are often applied to high-throughput measurement data arising from microarray, mass spectrometry and next-generation sequencing experiments for selecting markers, predicting phenotype and grouping objects or genes. Less explicitly, classification is at the core of a wide range of tools such as predictors of genes, protein function, functional or genetic interactions, etc., and used extensively in systems biology. A course on pattern recognition (or machine learning) should therefore be at the core of any bioinformatics education program. In this review, we discuss the main elements of a pattern recognition course, based on material developed for courses taught at the BSc, MSc and PhD levels to an audience of bioinformaticians, computer scientists and life scientists. We pay attention to common problems and pitfalls encountered in applications and in interpretation of the results obtained.

  13. Storyboards for Meaningful Patterns

    ERIC Educational Resources Information Center

    Dubon, Lucille P.; Shafer, Kathryn G.

    2010-01-01

    The initial focus of this kindergarten-level action research project was on identifying which students could create a pattern. The focus then shifted to helping all students successfully achieve this goal. The intervention uses a storyboard where students select colored cubes to represent objects and then snap the cubes together as indicated on…

  14. Fixture for forming evaporative pattern (EPC) process patterns

    DOEpatents

    Turner, Paul C.; Jordan, Ronald R.; Hansen, Jeffrey S.

    1993-01-01

    A method of casting metal using evaporative pattern casting process patterns in combination with a fixture for creating and maintaining a desired configuration in flexible patterns. A pattern is constructed and gently bent to the curvature of a suitable fixture. String or thin wire, which burns off during casting, is used to tie the pattern to the fixture. The fixture with pattern is dipped in a commercially available refractory wash to prevent metal adherence and sticking to the fixture. When the refractory wash is dry, the fixture and pattern are placed in a flask, and sand is added and compacted by vibration. The pattern remains in position, restrained by the fixture. Metal that is poured directly into the pattern replaces the pattern exactly but does not contact or weld to the fixture due to the protective refractory layer. When solid, the casting is easily separated from the fixture. The fixture can be cleaned for reuse in conventional casting cleaning equipment.

  15. Expendable Pattern Casting Technology

    NASA Astrophysics Data System (ADS)

    1990-07-01

    The expendable pattern casting (EPC) process is a potential casting process breakthrough which could dramatically improve the competitiveness of the U.S. foundry industry. Cooperatively supported by U.S. Industry and the Department of Energy and managed by the American Foundrymen's Society, a project was started in May 1989 to develop and optimize expendable pattern casting technology. Four major tasks were conducted in the first phase of the project. Those tasks involved: (1) reviewing published literature to determine the major problems in the EPC process; (2) evaluating factors influencing sand flow and compaction; (3) evaluating and comparing casting precision obtained in the EPC process with that obtained in other processes; and (4) identifying critical parameters that control dimensional precision and defect formation in EP castings.

  16. Expandable pattern casting research

    NASA Astrophysics Data System (ADS)

    1993-09-01

    The Expandable Pattern Casting (EPC) Process is a developing foundry technology that allows designers the opportunity to consolidate parts, reduce machining, and minimize assembly operations. An air gauging system was developed for measuring foam patterns; exact shrinkage depended on type and density of the foam. Compaction studies showed that maximum sand densities in cavities and under overhangs are achieved with vibrational amplitudes 0.001-0.004 in., and that sand moved most freely within a few inches of the top free surface. Key to complete mold filling while minimizing casting defects lies in removing the foam decomposition products. The most precise iron castings were made by EPC in four commercial EPC foundries, with attention paid to molding and compaction. EP cast 60-45-12 ductile iron had yield strengths, ultimate strengths, and elastic modulus similar to conventionally cast ductile iron cast from the same ladle.

  17. Hidden patterns of reciprocity.

    PubMed

    Syi

    2014-03-21

    Reciprocity can help the evolution of cooperation. To model both types of reciprocity, we need the concept of strategy. In the case of direct reciprocity there are four second-order action rules (Simple Tit-for-tat, Contrite Tit-for-tat, Pavlov, and Grim Trigger), which are able to promote cooperation. In the case of indirect reciprocity the key component of cooperation is the assessment rule. There are, again, four elementary second-order assessment rules (Image Scoring, Simple Standing, Stern Judging, and Shunning). The eight concepts can be formalized in an ontologically thin way we need only an action predicate and a value function, two agent concepts, and the constant of goodness. The formalism helps us to discover that the action and assessment rules can be paired, and that they show the same patterns. The logic of these patterns can be interpreted with the concept of punishment that has an inherent paradoxical nature.

  18. Patterns of sleep behaviour.

    NASA Technical Reports Server (NTRS)

    Webb, W. B.

    1972-01-01

    Discussion of the electroencephalogram as the critical measurement procedure for sleep research, and survey of major findings that have emerged in the last decade on the presence of sleep within the twenty-four-hour cycle. Specifically, intrasleep processes, frequency of stage changes, sequence of stage events, sleep stage amounts, temporal patterns of sleep, and stability of intrasleep pattern in both man and lower animals are reviewed, along with some circadian aspects of sleep, temporal factors, and number of sleep episodes. It is felt that it is particularly critical to take the presence of sleep into account whenever performance is considered. When it is recognized that responsive performance is extremely limited during sleep, it is easy to visualize the extent to which performance is controlled by sleep itself.

  19. Hidden patterns of reciprocity.

    PubMed

    Syi

    2014-03-21

    Reciprocity can help the evolution of cooperation. To model both types of reciprocity, we need the concept of strategy. In the case of direct reciprocity there are four second-order action rules (Simple Tit-for-tat, Contrite Tit-for-tat, Pavlov, and Grim Trigger), which are able to promote cooperation. In the case of indirect reciprocity the key component of cooperation is the assessment rule. There are, again, four elementary second-order assessment rules (Image Scoring, Simple Standing, Stern Judging, and Shunning). The eight concepts can be formalized in an ontologically thin way we need only an action predicate and a value function, two agent concepts, and the constant of goodness. The formalism helps us to discover that the action and assessment rules can be paired, and that they show the same patterns. The logic of these patterns can be interpreted with the concept of punishment that has an inherent paradoxical nature. PMID:24368125

  20. Patterns of Flux Emergence

    NASA Astrophysics Data System (ADS)

    Title, A.; Cheung, M.

    2008-05-01

    The high spatial resolution and high cadence of the Solar Optical Telescope on the JAXA Hinode spacecraft have allowed capturing many examples of magnetic flux emergence from the scale of granulation to active regions. The observed patterns of emergence are quite similar. Flux emerges as a array of small bipoles on scales from 1 to 5 arc seconds throughout the region that the flux eventually condenses. Because the fields emerging from the underlying flux rope my appear many in small segments and the total flux (absolute sum) is not a conserved quantity the amount of total flux on the surface may vary significantly during the emergence process. Numerical simulations of flux emergence exhibit patterns similar to observations. Movies of both observations and numerical simulations will be presented.

  1. Shells and Patterns

    ERIC Educational Resources Information Center

    Sutley, Jane

    2009-01-01

    "Shells and Patterns" was a project the author felt would easily put smiles on the faces of her fifth-graders, and teach them about unity and the use of watercolor pencils as well. It was thrilling to see the excitement in her students as they made their line drawings of shells come to life. For the most part, they quickly got the hang of…

  2. Labyrinthine dissipative patterns

    NASA Astrophysics Data System (ADS)

    Bordeu, I.

    2016-05-01

    A wide range of physical systems exhibit labyrinthine patterns as transient or steady states. One of the routes by which labyrinths emerge is through the destabilization of a localized structure through a curvature instability. In this work, we will study the emergence of labyrinths through this mechanism in different physical contexts, including nonlinear cavity optics, vegetation dynamics and chemical reactions. Furthermore, it is shown that the resulting labyrinths can be classified depending on their connectivities.

  3. Patterns of Emphysema Heterogeneity

    PubMed Central

    Valipour, Arschang; Shah, Pallav L.; Gesierich, Wolfgang; Eberhardt, Ralf; Snell, Greg; Strange, Charlie; Barry, Robert; Gupta, Avina; Henne, Erik; Bandyopadhyay, Sourish; Raffy, Philippe; Yin, Youbing; Tschirren, Juerg; Herth, Felix J.F.

    2016-01-01

    Background Although lobar patterns of emphysema heterogeneity are indicative of optimal target sites for lung volume reduction (LVR) strategies, the presence of segmental, or sublobar, heterogeneity is often underappreciated. Objective The aim of this study was to understand lobar and segmental patterns of emphysema heterogeneity, which may more precisely indicate optimal target sites for LVR procedures. Methods Patterns of emphysema heterogeneity were evaluated in a representative cohort of 150 severe (GOLD stage III/IV) chronic obstructive pulmonary disease (COPD) patients from the COPDGene study. High-resolution computerized tomography analysis software was used to measure tissue destruction throughout the lungs to compute heterogeneity (≥ 15% difference in tissue destruction) between (inter-) and within (intra-) lobes for each patient. Emphysema tissue destruction was characterized segmentally to define patterns of heterogeneity. Results Segmental tissue destruction revealed interlobar heterogeneity in the left lung (57%) and right lung (52%). Intralobar heterogeneity was observed in at least one lobe of all patients. No patient presented true homogeneity at a segmental level. There was true homogeneity across both lungs in 3% of the cohort when defining heterogeneity as ≥ 30% difference in tissue destruction. Conclusion Many LVR technologies for treatment of emphysema have focused on interlobar heterogeneity and target an entire lobe per procedure. Our observations suggest that a high proportion of patients with emphysema are affected by interlobar as well as intralobar heterogeneity. These findings prompt the need for a segmental approach to LVR in the majority of patients to treat only the most diseased segments and preserve healthier ones. PMID:26430783

  4. [Electrocardiograph beat pattern recognition].

    PubMed

    Zhou, Qunyi; Lu, Xudong; Duan, Huiling

    2005-02-01

    It is very important to recognize arrhythmia in clinical electrocardiography (ECG) analysis. The fundamental of beat pattern recognition is presented in this paper. Various prevalent methods for arrhythmia recognitiion are categorized and summarized, based on which the advantages and disadvantages among the methods are compared, and the main problems are discussed in depth. At last, the development trend of arrhythmia recognition technology is pointed out.

  5. Australopithecine enamel prism patterns.

    PubMed

    Vrba, E S; Grine, F E

    1978-11-24

    Following a recent suggestion that tooth enamel prism shape differs within Hominoidea, the teeth of a number of extinct and extant hominoid species were analyzed by scanning electron microscopy. The enamel prism patterns of some gracile and robust australopithecine specimens from Sterkfontein, Swartkrans, and Kromdraai are recorded. The characteristic arrangements of enamel prisms in all modern and extinct hominoid species were found to be essentially similar. The implications of enamel prisms for phylogenetic deduction in Hominoidea are discussed. PMID:102032

  6. LANL application communication patterns

    SciTech Connect

    Pakiin, Scott

    2011-01-10

    This brief presentation describes the communication patterns used by a set of unclassified applications developed at Los Alamos National Laboratory: XNobel/XRAGE/RAGE/SAGE, Krak, Sweep3D, and Partisn. It mentions which processes communicate with which other processes, whether the application is typically run in a strong-scaling mode or a weak-scaling mode, what message sizes are commonly used, and how the application's performance changes at scale.

  7. Tooth patterning and evolution.

    PubMed

    Salazar-Ciudad, Isaac

    2012-12-01

    Teeth are a good system for studying development and evolution. Tooth development is largely independent of the rest of the body and teeth can be grown in culture to attain almost normal morphology. Their development is not affected by the patterns of movement or sensorial perception in the embryo. Teeth are hard and easily preserved. Thus, there is plenty of easily accessible information about the patterns of morphological variation occurring between and within species. This review summarises recent work and describes how tooth development can be understood as the coupling between a reaction-diffusion system and differential growth produced by diffusible growth factors: which growth factors are involved, how they affect each other's expression and how they affect the spatial patterns of proliferation that lead to final morphology. There are some aspects of tooth development, however, that do not conform to some common assumptions in many reaction-diffusion models. Those are discussed here since they provide clues about how reaction-diffusion systems may work in actual developmental systems. Mathematical models implementing what we know about tooth development are discussed.

  8. Pattern Driven Stress Localization

    NASA Astrophysics Data System (ADS)

    Croll, Andrew; Crosby, Alfred

    2010-03-01

    The self-assembly of patterns from isotropic initial states is a major driver of modern soft-matter research. This avenue of study is directed by the desire to understand the complex physics of the varied structures found in Nature, and by technological interest in functional materials that may be derived through biomimicry. In this work we show how a simple striped phase can respond with significant complexity to an appropriately chosen perturbation. In particular, we show how a buckled elastic plate transitions into a state of stress localization using a simple, self-assembled variation in surface topography. The collection of topographic boundaries act in concert to change the state from isotropic sinusoidal wrinkles, to sharp folds or creases separated by relatively flat regions. By varying the size of the imposed topographic pattern or the wavelength of the wrinkles, we construct a state diagram of the system. The localized state has implications for both biological systems, and for the control of non-linear pattern formation.

  9. Gardosian Patterns in Tribology

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher

    2004-01-01

    The following paper is a memorial retrospective on selected research of Dr. Michael N. Gardos. Dr. Gardos spent his professional career engaged in tribological research which often extended the scientific boundaries of the field. Several of the concepts he put forth into the tribology community were initially met with grave skepticism but over time his views have been largely embraced but not widely acknowledged. His approach to new research topics was often characterized by these qualities: 1) pioneering points of view, 2) the use of the model experiment, and 3) the presence of multiple research agendas for each single experiment. I have chosen to name his research approach as "Gardosian Patterns" in honor of his contributions to Tribology. Three specific examples of these patterns will be reviewed. One is the concept of atomic level tailoring of materials to control macroscopic properties. A second is the use of a model ball polishing experiment to identify high fracture toughness ceramics for use in rolling element bearings. A third Gardosian Pattern example is his pioneering work with the tribology of diamond and diamond films in which he proposed controlling friction via surface bond tailoring. In these examples, Gardos utilized conventional research tools in unconventional ways and, at times, even developed new tools which have become part of the mainstream. His remarkable career has left a positive and lasting mark on Tribology.

  10. Blood stain pattern analysis.

    PubMed

    Peschel, O; Kunz, S N; Rothschild, M A; Mützel, E

    2011-09-01

    Bloodstain pattern analysis (BPA) refers to the collection, categorization and interpretation of the shape and distribution of bloodstains connected with a crime. These kinds of stains occur in a considerable proportion of homicide cases. They offer extensive information and are an important part of a functional, medically and scientifically based reconstruction of a crime. The following groups of patterns can essentially be distinguished: dripped and splashed blood, projected blood, impact patterns, cast-off stains, expirated and transferred bloodstains. A highly qualified analysis can help to estimate facts concerning the location, quality and intensity of an external force. A sequence of events may be recognized, and detailed questions connected with the reconstruction of the crime might be answered. In some cases, BPA helps to distinguish between accident, homicide and suicide or to identify bloodstains originating from a perpetrator. BPA is based on systematic training, a visit to the crime scene or alternatively good photographic documentation, and an understanding and knowledge of autopsy findings or statements made by the perpetrator and/or victim. A BPA working group has been established within the German Society of Legal Medicine aiming to put the knowledge and practical applications of this subdiscipline of forensic science on a wider basis. PMID:21069481

  11. Conditional entropy of ordinal patterns

    NASA Astrophysics Data System (ADS)

    Unakafov, Anton M.; Keller, Karsten

    2014-02-01

    In this paper we investigate a quantity called conditional entropy of ordinal patterns, akin to the permutation entropy. The conditional entropy of ordinal patterns describes the average diversity of the ordinal patterns succeeding a given ordinal pattern. We observe that this quantity provides a good estimation of the Kolmogorov-Sinai entropy in many cases. In particular, the conditional entropy of ordinal patterns of a finite order coincides with the Kolmogorov-Sinai entropy for periodic dynamics and for Markov shifts over a binary alphabet. Finally, the conditional entropy of ordinal patterns is computationally simple and thus can be well applied to real-world data.

  12. Perforation patterned electrical interconnects

    DOEpatents

    Frey, Jonathan

    2014-01-28

    This disclosure describes systems and methods for increasing the usable surface area of electrical contacts within a device, such as a thin film solid state device, through the implementation of electrically conductive interconnects. Embodiments described herein include the use of a plurality of electrically conductive interconnects that penetrate through a top contact layer, through one or more multiple layers, and into a bottom contact layer. The plurality of conductive interconnects may form horizontal and vertical cross-sectional patterns. The use of lasers to form the plurality of electrically conductive interconnects from reflowed layer material further aids in the manufacturing process of a device.

  13. Electrohydrodynamically patterned colloidal crystals

    NASA Technical Reports Server (NTRS)

    Hayward, Ryan C. (Inventor); Poon, Hak F. (Inventor); Xiao, Yi (Inventor); Saville, Dudley A. (Inventor); Aksay, Ilhan A. (Inventor)

    2003-01-01

    A method for assembling patterned crystalline arrays of colloidal particles using ultraviolet illumination of an optically-sensitive semiconducting anode while using the anode to apply an electronic field to the colloidal particles. The ultraviolet illumination increases current density, and consequently, the flow of the colloidal particles. As a result, colloidal particles can be caused to migrate from non-illuminated areas of the anode to illuminated areas of the anode. Selective illumination of the anode can also be used to permanently affix colloidal crystals to illuminated areas of the anode while not affixing them to non-illuminated areas of the anode.

  14. Patterns of public participation.

    PubMed

    Slutsky, Jean; Tumilty, Emma; Max, Catherine; Lu, Lanting; Tantivess, Sripen; Hauegen, Renata Curi; Whitty, Jennifer A; Weale, Albert; Pearson, Steven D; Tugendhaft, Aviva; Wang, Hufeng; Staniszewska, Sophie; Weerasuriya, Krisantha; Ahn, Jeonghoon; Cubillos, Leonardo

    2016-08-15

    Purpose - The paper summarizes data from 12 countries, chosen to exhibit wide variation, on the role and place of public participation in the setting of priorities. The purpose of this paper is to exhibit cross-national patterns in respect of public participation, linking those differences to institutional features of the countries concerned. Design/methodology/approach - The approach is an example of case-orientated qualitative assessment of participation practices. It derives its data from the presentation of country case studies by experts on each system. The country cases are located within the historical development of democracy in each country. Findings - Patterns of participation are widely variable. Participation that is effective through routinized institutional processes appears to be inversely related to contestatory participation that uses political mobilization to challenge the legitimacy of the priority setting process. No system has resolved the conceptual ambiguities that are implicit in the idea of public participation. Originality/value - The paper draws on a unique collection of country case studies in participatory practice in prioritization, supplementing existing published sources. In showing that contestatory participation plays an important role in a sub-set of these countries it makes an important contribution to the field because it broadens the debate about public participation in priority setting beyond the use of minipublics and the observation of public representatives on decision-making bodies. PMID:27468773

  15. Evolutionary pattern search algorithms

    SciTech Connect

    Hart, W.E.

    1995-09-19

    This paper defines a class of evolutionary algorithms called evolutionary pattern search algorithms (EPSAs) and analyzes their convergence properties. This class of algorithms is closely related to evolutionary programming, evolutionary strategie and real-coded genetic algorithms. EPSAs are self-adapting systems that modify the step size of the mutation operator in response to the success of previous optimization steps. The rule used to adapt the step size can be used to provide a stationary point convergence theory for EPSAs on any continuous function. This convergence theory is based on an extension of the convergence theory for generalized pattern search methods. An experimental analysis of the performance of EPSAs demonstrates that these algorithms can perform a level of global search that is comparable to that of canonical EAs. We also describe a stopping rule for EPSAs, which reliably terminated near stationary points in our experiments. This is the first stopping rule for any class of EAs that can terminate at a given distance from stationary points.

  16. Archetypes as action patterns.

    PubMed

    Hogenson, George B

    2009-06-01

    The discovery of mirror neurons by researchers at the University of Parma promises to radically alter our understanding of fundamental cognitive and affective states. This paper explores the relationship of mirror neurons to Jung's theory of archetypes and proposes that archetypes may be viewed as elementary action patterns. The paper begins with a review of a proposed interpretation of the fainting spells of S. Freud in his relationship with Jung as an example of an action pattern that also defines an archetypal image. The challenge that mirror neurons present to traditional views in analytical psychology and psychoanalysis, however, is that they operate without recourse to a cognitive processing element. This is a position that is gaining increasing acceptance in other fields as well. The paper therefore reviews the most recent claims made by the Boston Process of Change Study Group as well as conclusions drawn from dynamic systems views of development and theoretical robotics to underline the conclusion that unconscious agency is not a requirement for coherent action. It concludes with the suggestion that this entire body of research may lead to the conclusion that the dynamic unconscious is an unnecessary hypothesis in psychoanalysis and analytical psychology.

  17. Patterns of Negotiation

    NASA Astrophysics Data System (ADS)

    Sood, Suresh; Pattinson, Hugh

    Traditionally, face-to-face negotiations in the real world have not been looked at as a complex systems interaction of actors resulting in a dynamic and potentially emergent system. If indeed negotiations are an outcome of a dynamic interaction of simpler behavior just as with a complex system, we should be able to see the patterns contributing to the complexities of a negotiation under study. This paper and the supporting research sets out to show B2B (business-to-business) negotiations as complex systems of interacting actors exhibiting dynamic and emergent behavior. This paper discusses the exploratory research based on negotiation simulations in which a large number of business students participate as buyers and sellers. The student interactions are captured on video and a purpose built research method attempts to look for patterns of interactions between actors using visualization techniques traditionally reserved to observe the algorithmic complexity of complex systems. Students are videoed negotiating with partners. Each video is tagged according to a recognized classification and coding scheme for negotiations. The classification relates to the phases through which any particular negotiation might pass, such as laughter, aggression, compromise, and so forth — through some 30 possible categories. Were negotiations more or less successful if they progressed through the categories in different ways? Furthermore, does the data depict emergent pathway segments considered to be more or less successful? This focus on emergence within the data provides further strong support for face-to-face (F2F) negotiations to be construed as complex systems.

  18. Archetypes as action patterns.

    PubMed

    Hogenson, George B

    2009-06-01

    The discovery of mirror neurons by researchers at the University of Parma promises to radically alter our understanding of fundamental cognitive and affective states. This paper explores the relationship of mirror neurons to Jung's theory of archetypes and proposes that archetypes may be viewed as elementary action patterns. The paper begins with a review of a proposed interpretation of the fainting spells of S. Freud in his relationship with Jung as an example of an action pattern that also defines an archetypal image. The challenge that mirror neurons present to traditional views in analytical psychology and psychoanalysis, however, is that they operate without recourse to a cognitive processing element. This is a position that is gaining increasing acceptance in other fields as well. The paper therefore reviews the most recent claims made by the Boston Process of Change Study Group as well as conclusions drawn from dynamic systems views of development and theoretical robotics to underline the conclusion that unconscious agency is not a requirement for coherent action. It concludes with the suggestion that this entire body of research may lead to the conclusion that the dynamic unconscious is an unnecessary hypothesis in psychoanalysis and analytical psychology. PMID:19531123

  19. Female Pattern Hair Loss

    PubMed Central

    Herskovitz, Ingrid; Tosti, Antonella

    2013-01-01

    Context: Female pattern hair loss (FPHL) also known as female androgenetic alopecia is a common condition afflicting millions of women that can be cosmetically disrupting. Prompt diagnosis and treatment are essential for obtaining optimal outcome. This review addresses the clinical presentation of female pattern hair loss, its differential diagnosis and treatment modalities. Evidence Acquisition: A) Diffuse thinning of the crown region with preservation of the frontal hairline (Ludwig’s type) B) The “Christmas tree pattern” where the thinning is wider in the frontal scalp giving the alopecic area a triangular shaped figure resembling a christmas tree. C) Thinning associated with bitemporal recession (Hamilton type). Generally, FPHL is not associated with elevated androgens. Less commonly females with FPHL may have other skin or general signs of hyperandrogenism such as hirsutism, acne, irregular menses, infertility, galactorrhea and insulin resistance. The most common endocrinological abnormality associated with FPHL is polycystic ovarian syndrome (PCOS). Results: The most important diseases to consider in the differential diagnosis of FPHL include Chronic Telogen Effluvium (CTE), Permanent Alopecia after Chemotherapy (PAC), Alopecia Areata Incognito (AAI) and Frontal Fibrosing Alopecia (FFA). This review describes criteria for distinguishing these conditions from FPHL. Conclusions: The only approved treatment for FPHL, which is 2% topical Minoxidil, should be applied at the dosage of 1ml twice day for a minimum period of 12 months. This review will discuss off-label alternative modalities of treatment including 5-alfa reductase inhibitors, antiandrogens, estrogens, prostaglandin analogs, lasers, light treatments and hair transplantation. PMID:24719635

  20. Complex networks: Patterns of complexity

    NASA Astrophysics Data System (ADS)

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2010-07-01

    The Turing mechanism provides a paradigm for the spontaneous generation of patterns in reaction-diffusion systems. A framework that describes Turing-pattern formation in the context of complex networks should provide a new basis for studying the phenomenon.

  1. Fractal dynamics of bioconvective patterns

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1991-01-01

    Biologically generated cellular patterns, sometimes called bioconvective patterns, are found to cluster into aggregates which follow fractal growth dynamics akin to diffusion-limited aggregation (DLA) models. The pattern formed is self-similar with fractal dimension of 1.66 +/-0.038. Bioconvective DLA branching results from thermal roughening which shifts the balance between ordering viscous forces and disordering cell motility and random diffusion. The phase diagram for pattern morphology includes DLA, boundary spokes, random clusters, and reverse clusters.

  2. The Dissemination of Pedagogical Patterns

    ERIC Educational Resources Information Center

    Bennedsen, Jens

    2006-01-01

    Pedagogical patterns have been around since 1995, but several authors claim their impact is limited. However, these claims are based on authors' own observations and not on methodical evaluations of the use and dissemination of pedagogical patterns. This claim is in contrast to the vision of the creators of pedagogical patterns--they think…

  3. Patterns to Develop Algebraic Reasoning

    ERIC Educational Resources Information Center

    Stump, Sheryl L.

    2011-01-01

    What is the role of patterns in developing algebraic reasoning? This important question deserves thoughtful attention. In response, this article examines some differing views of algebraic reasoning, discusses a controversy regarding patterns, and describes how three types of patterns--in contextual problems, in growing geometric figures, and in…

  4. Pattern, Growth and Control

    PubMed Central

    Lander, Arthur D.

    2011-01-01

    The view of biology as goal-directed engineering has deep historical roots in developmental biology, a field currently benefitting from an influx of ideas and methods from systems biology. Systems biology draws on non-biological paradigms to explain developmental mechanisms of control, the specific type of regulation that achieves or maintains a desired end. This review highlights some of the current efforts designed to elucidate basic design principles underlying the engineering objectives of robustness, precision, and scaling that are required during developmental control of growth and pattern formation. Examples from vertebrate and invertebrate development are used to illustrate general principles including the value of integral feedback in achieving set-point control; the usefulness of self-organizing behavior; the importance of recognizing and appropriately handling noise; and the No Free Lunch theory. Through the examination of such principles, systems biology offers a functional framework to make sense of the mechanistic complexity of organismal development. PMID:21414486

  5. [Normal myelination patterns].

    PubMed

    González Alenda, F J; Pérez-Romero, M; Sánchez, I; Frutos, R; Fraile, E; Romero, J; Carrasco, E G

    1991-12-01

    The MR images obtained of brain during the process of myelination taking place from birth to 2 years of age are analyzed. Basically, the study focuses on the changes in signal intensity experienced by the elements of the brain in the different sequences, consisting in an increase (T1 weighted sequence) or decrease (T2 sequences) in the signal. The chronological evolution of these changes is compared with the classic myelination pattern, described prior to the development of MR, based on necropsies. Also assessed were the progressive changes in the signals of the gray and white matter, reflecting their hydric contents, throughout the period of maturation of the brain structures. It is concluded that MR imaging is presently the diagnostic method of choice in the monitoring of myelination. MR spectroscopy studies offer important perspectives for assessment and follow up of this process from the metabolic point of view.

  6. Female pattern hair loss.

    PubMed

    Singal, Archana; Sonthalia, Sidharth; Verma, Prashant

    2013-01-01

    Female pattern hair loss (FPHL) is a common cause of hair loss in women characterized by diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline. Its prevalence increases with advancing age and is associated with significant psychological morbidity. The pathophysiology of FPHL is still not completely understood and seems to be multifactorial. Although androgens have been implicated, the involvement of androgen-independent mechanisms is evident from frequent lack of clinical or biochemical markers of hyperandrogenism in affected women. The role of genetic polymorphisms involving the androgen and estrogen receptors is being increasingly recognized in its causation and predicting treatment response to anti-androgens. There are different clinical patterns and classifications of FPHL, knowledge of which facilitates patient management and research. Chronic telogen effluvium remains as the most important differential diagnosis. Thorough history, clinical examination, and evaluation are essential to confirm diagnosis. Patients with clinical signs of androgen excess require assessment of biochemical parameters and imaging studies. It is prudent to screen the patients for metabolic syndrome and cardiovascular risk factors. The treatment comprises medical and/or surgical modalities. Medical treatment should be initiated early as it effectively arrests hair loss progression rather than stimulating regrowth. Minoxidil continues to be the first line therapy whereas anti-androgens form the second line of treatment. The progressive nature of FPHL mandates long-term treatment for sustained effect. Medical therapy may be supplemented with cosmetic concealment in those desirous of greater hair density. Surgery may be worthwhile in some carefully selected patients. PMID:23974580

  7. Smart pattern recognition

    NASA Astrophysics Data System (ADS)

    Alfalou, A.; Brosseau, C.; Alam, M. S.

    2013-03-01

    The purpose of this paper is to test correlation methods for pattern recognition applications. A broad overview of the main correlation architectures is first given. Many correlation data are compared with those obtained from standard pattern recognition methods. We used our simulations to predict improved decisional performance from correlation methods. More specifically, we are focused on the POF filter and composite filter family. We present an optimized composite correlation filter, called asymmetric segmented phase-only filter (ASPOF) for mobile target recognition applications. The main objective is to find a compromise between the number of references to be merged in the correlation filter and the time needed for making a decision. We suggest an all-numerical implementation of a VanderLugt (VLC) type composite filter. The aim of this all-numerical implementation is to take advantage of the benefits of the correlation methods and make the correlator easily reconfigurable for various scenarios. The use of numerical implementation of the optical Fourier transform improves the decisional performance of the correlator. Further, it renders the correlator less sensitive to the saturation phenomenon caused by the increased number of references used for fabricating the composite filter. Different tests are presented making use of the peak-to-correlation energy criterion and ROC curves. These tests confirm the validity ofour technique. Elderly fall detection and underwater mine detection are two applications which are considered for illustrating the benefits of our approach. The present work is motivated by the need for detailed discussions of the choice of the correlation architecture for these specific applications, pre-processing in the input plane and post processing in the output plane techniques for such analysis.

  8. Validation of an automated punctate mechanical stimuli delivery system designed for fMRI studies in rodents.

    PubMed

    Governo, Ricardo Jose Moylan; Prior, Malcolm John William; Morris, Peter Gordon; Marsden, Charles Alexander; Chapman, Victoria

    2007-06-15

    Functional magnetic resonance imaging (fMRI) is increasingly being used for animal studies studying the transmission of nociceptive information. Application of noxious mechanical stimuli is widely used for animal and human assessment of pain processing. Any accessory hardware used in animal imaging studies must, however, be sufficiently small to fit in the magnet bore diameter and be non-magnetic. We have developed a system that can apply mechanical stimuli simultaneously with fMRI. This system consists of a standardized instrument to deliver mechanical stimuli (VonFrey monofilament) and a gas-pressured mechanical transducer. These components were integrated with a computer console that controlled the period of stimuli to match acquisition scans. Preliminary experiments demonstrated that the force-stimulus transducer did not influence MRI signal to noise ratio. Mechanical stimulation of the hindpaw significantly increased blood oxygen level dependent (BOLD) signal intensity in several midbrain regions involved in the processing of nociceptive information in the rat (p<0.001, uncorrected for multiple comparisons). This system can be applied to both animal and human imaging studies and has a wide range of applications for studies of nociceptive processing. PMID:17368787

  9. Resolution of choroidal neovascularization secondary to punctate inner choroidopathy (PIC) with intravitreal anti-VEGF agents: a case series.

    PubMed

    Mangat, Simran S; Ramasamy, B; Prasad, Som; Walters, Gavin; Mohammed, Moin; Mckibbin, Martin

    2011-01-01

    Case series of four patients with CNVM secondary to PIC treated solely with anti VEGF in three cases and in combination with PDT in the other. This series reveals long term follow up (3 months to 28 months) which is currently not described in the literature.

  10. 3-D laser patterning process utilizing horizontal and vertical patterning

    DOEpatents

    Malba, Vincent; Bernhardt, Anthony F.

    2000-01-01

    A process which vastly improves the 3-D patterning capability of laser pantography (computer controlled laser direct-write patterning). The process uses commercially available electrodeposited photoresist (EDPR) to pattern 3-D surfaces. The EDPR covers the surface of a metal layer conformally, coating the vertical as well as horizontal surfaces. A laser pantograph then patterns the EDPR, which is subsequently developed in a standard, commercially available developer, leaving patterned trench areas in the EDPR. The metal layer thereunder is now exposed in the trench areas and masked in others, and thereafter can be etched to form the desired pattern (subtractive process), or can be plated with metal (additive process), followed by a resist stripping, and removal of the remaining field metal (additive process). This improved laser pantograph process is simpler, faster, move manufacturable, and requires no micro-machining.

  11. The logical model for pattern representation

    NASA Astrophysics Data System (ADS)

    Telnarova, Zdenka; Schenk, Jiri

    2016-06-01

    Patterns are mentioned usually in the extraction context. Little stress is posed in their representation and management. This paper is focused on representation of the patterns, manipulation with patterns and query patterns. Crucial issue can be seen in systematic approach to pattern management and specific pattern query language which takes into consideration semantics of patterns..

  12. FLARING PATTERNS IN BLAZARS

    SciTech Connect

    Paggi, A.; Cavaliere, A.; Tavani, M.; Vittorini, V.; D'Ammando, F.

    2011-08-01

    Blazars radiate from relativistic jets launched by a supermassive black hole along our line of sight; the subclass of flat spectrum radio quasars exhibits broad emission lines, a telltale sign of a gas-rich environment and high accretion rate, contrary to the other subclass of the BL Lacertae objects. We show that this dichotomy of the sources in physical properties is enhanced in their flaring activity. The BL Lac flares yielded spectral evidence of being driven by further acceleration of highly relativistic electrons in the jet. Here, we discuss spectral fits of multi-{lambda} data concerning strong flares of the two flat spectrum radio quasars 3C 454.3 and 3C 279 recently detected in {gamma}-rays by the AGILE and Fermi satellites. We find that optimal spectral fits are provided by external Compton radiation enhanced by increasing production of thermal seed photons by growing accretion. We find such flares to trace patterns on the jet-power-electron-energy plane that diverge from those followed by flaring BL Lac objects and discuss why these occur.

  13. Pattern, growth, and control.

    PubMed

    Lander, Arthur D

    2011-03-18

    Systems biology seeks not only to discover the machinery of life but to understand how such machinery is used for control, i.e., for regulation that achieves or maintains a desired, useful end. This sort of goal-directed, engineering-centered approach also has deep historical roots in developmental biology. Not surprisingly, developmental biology is currently enjoying an influx of ideas and methods from systems biology. This Review highlights current efforts to elucidate design principles underlying the engineering objectives of robustness, precision, and scaling as they relate to the developmental control of growth and pattern formation. Examples from vertebrate and invertebrate development are used to illustrate general lessons, including the value of integral feedback in achieving set-point control; the usefulness of self-organizing behavior; the importance of recognizing and appropriately handling noise; and the absence of "free lunch." By illuminating such principles, systems biology is helping to create a functional framework within which to make sense of the mechanistic complexity of organismal development. PMID:21414486

  14. Multinomial pattern matching revisited

    NASA Astrophysics Data System (ADS)

    Horvath, Matthew S.; Rigling, Brian D.

    2015-05-01

    Multinomial pattern matching (MPM) is an automatic target recognition algorithm developed for specifically radar data at Sandia National Laboratories. The algorithm is in a family of algorithms that first quantizes pixel value into Nq bins based on pixel amplitude before training and classification. This quantization step reduces the sensitivity of algorithm performance to absolute intensity variation in the data, typical of radar data where signatures exhibit high variation for even small changes in aspect angle. Our previous work has focused on performance analysis of peaky template matching, a special case of MPM where binary quantization is used (Nq = 2). Unfortunately references on these algorithms are generally difficult to locate and here we revisit the MPM algorithm and illustrate the underlying statistical model and decision rules for two algorithm interpretations: the 1-of-K vector form and the scalar. MPM can also be used as a detector and specific attention is given to algorithm tuning where "peak pixels" are chosen based on their underlying empirical probabilities according to a reward minimization strategy aimed at reducing false alarms in the detection scenario and false positives in a classification capacity. The algorithms are demonstrated using Monte Carlo simulations on the AFRL civilian vehicle dataset for variety of choices of Nq.

  15. Brugada ECG patterns in athletes.

    PubMed

    Chung, Eugene H

    2015-01-01

    Brugada syndrome is responsible for up to 4% of all sudden cardiac deaths worldwide and up to 20% of sudden cardiac deaths in patients with structurally normal hearts. Heterogeneity of repolarization and depolarization, particularly over the right ventricle and the outflow tract, is responsible for the arrhythmogenic substrate. The coved Type I ECG pattern is considered diagnostic of the syndrome but its prevalence is very low. Distinguishing between a saddle back Type 2 Brugada pattern and one of many "Brugada-like" patterns presents challenges especially in athletes. A number of criteria have been proposed to assess Brugada ECG patterns. Proper precordial ECG lead placement is paramount. This paper reviews Brugada syndrome, Brugada ECG patterns, and recently proposed criteria. Recommendations for evaluating a Brugada ECG pattern are provided.

  16. Pattern formation with proportionate growth

    NASA Astrophysics Data System (ADS)

    Dhar, Deepak

    It is a common observation that as baby animals grow, different body parts grow approximately at same rate. This property, called proportionate growth is remarkable in that it is not encountered easily outside biology. The models of growth that have been studied in Physics so far, e.g diffusion -limited aggregation, surface deposition, growth of crystals from melt etc. involve only growth at the surface, with the inner structure remaining frozen. Interestingly, patterns formed in growing sandpiles provide a very wide variety of patterns that show proportionate growth. One finds patterns with different features, with sharply defined boundaries. In particular, even with very simple rules, one can produce patterns that show striking resemblance to those seen in nature. We can characterize the asymptotic pattern exactly in some special cases. I will discuss in particular the patterns grown on noisy backgrounds. Supported by J. C. Bose fellowship from DST (India).

  17. Dissociation Patterns in Evolving Populations

    NASA Astrophysics Data System (ADS)

    Moreno, F. J.; Hernández, J. A.; Sánchez, F.

    2011-09-01

    The recent explosion and availability of mobility based technologies such as geographic information systems, cell phones equipped with built-in GPS, among others, are a valuable source of spatio-temporal data. However, only recently there have been works focused on identifying movement patterns in groups of moving entities. We focus on a particular movement pattern: dissociation. A dissociation pattern occurs when an entity that was once associated to a population, eventually separated from it and subsequently reintegrated it again. The backwarding and forwarding patterns are a type of dissociation where an entity stays behind or ahead of another entity, respectively. Dissociation really is a diversity generator, so instead avoiding it, taking advantage could be better to prevent premature convergence in evolutionary algorithms. In this work, we present formal mathematical definitions for these patterns. A discussion of how to use dissociation patterns as a mean to preserve diversity in evolutionary algorithms is also shown.

  18. Communication patterns and allocation strategies.

    SciTech Connect

    Leung, Vitus Joseph; Mache, Jens Wolfgang; Bunde, David P.

    2004-01-01

    Motivated by observations about job runtimes on the CPlant system, we use a trace-driven microsimulator to begin characterizing the performance of different classes of allocation algorithms on jobs with different communication patterns in space-shared parallel systems with mesh topology. We show that relative performance varies considerably with communication pattern. The Paging strategy using the Hilbert space-filling curve and the Best Fit heuristic performed best across several communication patterns.

  19. Cancer patterns in Canada.

    PubMed Central

    Wigle, D T; Mao, Y; Semenciw, R; Morrison, H I

    1986-01-01

    Cancer is diagnosed in about 70 000 Canadians each year and is the leading cause of the loss of potential years of life before age 75 among women. Life-threatening forms of cancer will develop in at least one of every three Canadian newborns during their lifetimes if current cancer risks are not reduced. Lung and breast cancers are, respectively, the leading causes of premature death due to cancer among men and women. Compared with other countries Canada has low death rates for stomach cancer but high rates for certain smoking-related cancers (those of the lung and of the mouth and throat), leukemia and cancers of the colon, breast and lymphatic tissues. Newfoundland has the highest rates of death from stomach cancer and the lowest rates of death from prostatic cancer, whereas the western provinces have the opposite pattern. The rates of death from lung cancer among men are highest in Quebec, the province with the highest prevalence of smoking. In Canada the overall rates of death from cancer increased by 32% among men from 1951 to 1983. However, among women they declined by 12% from 1951 to 1976 and increased from 1976 to 1983, particularly among those aged 55 to 74. The rising rates of death due to lung cancer were primarily responsible for these increases. Lung cancer will likely displace breast cancer as the leading cancer killer of Canadian women by 1990. Given the relatively low survival rates for cancers caused by smoking and the lack of substantial improvement in rates for the most frequent types of cancer, preventive strategies that include effective measures to reduce tobacco consumption are urgently required. PMID:3942929

  20. Stochastic Simulation of Turing Patterns

    NASA Astrophysics Data System (ADS)

    Fu, Zheng-Ping; Xu, Xin-Hang; Wang, Hong-Li; Ouyang, Qi

    2008-04-01

    We investigate the effects of intrinsic noise on Turing pattern formation near the onset of bifurcation from the homogeneous state to Turing pattern in the reaction-diffusion Brusselator. By performing stochastic simulations of the master equation and using Gillespie's algorithm, we check the spatiotemporal behaviour influenced by internal noises. We demonstrate that the patterns of occurrence frequency for the reaction and diffusion processes are also spatially ordered and temporally stable. Turing patterns are found to be robust against intrinsic fluctuations. Stochastic simulations also reveal that under the influence of intrinsic noises, the onset of Turing instability is advanced in comparison to that predicted deterministically.

  1. Learning with imperfectly labeled patterns

    NASA Technical Reports Server (NTRS)

    Chittineni, C. B.

    1979-01-01

    The problem of learning in pattern recognition using imperfectly labeled patterns is considered. The performance of the Bayes and nearest neighbor classifiers with imperfect labels is discussed using a probabilistic model for the mislabeling of the training patterns. Schemes for training the classifier using both parametric and non parametric techniques are presented. Methods for the correction of imperfect labels were developed. To gain an understanding of the learning process, expressions are derived for success probability as a function of training time for a one dimensional increment error correction classifier with imperfect labels. Feature selection with imperfectly labeled patterns is described.

  2. Lithographically patterned nanowire electrodeposition

    NASA Astrophysics Data System (ADS)

    Xiang, Chengxiang

    Lithographically patterned nanowire electrodeposition (LPNE) is a new method for fabricating polycrystalline metal nanowires using electrodeposition. In LPNE, a sacrificial metal (M1 = silver or nickel) layer, 5 - 100 nm in thickness, is first vapor deposited onto a glass, oxidized silicon, or Kapton polymer film. A photoresist (PR) layer is then deposited, photopatterned, and the exposed Ag or Ni is removed by wet etching. The etching duration is adjusted to produce an undercut ≈300 nm in width at the edges of the exposed PR. This undercut produces a horizontal trench with a precisely defined height equal to the thickness of theM1 layer. Within this trench, a nanowire of metal M2 is electrodeposited (M2 = gold, platinum, palladium, or bismuth). Finally the PR layer and M1 layer are removed. The nanowire height and width can be independently controlled down to minimum dimensions of 5 nm (h) and 11 nm (w), for example, in the case of platinum. These nanowires can be 1 cm in total length. We measure the temperature-dependent resistance of 100 um sections of Au and Pd wires in order to estimate an electrical grain size for comparison with measurements by X-ray diffraction and transmission electron microscopy. Nanowire arrays can be postpatterned to produce two-dimensional arrays of nanorods. Nanowire patterns can also be overlaid one on top of another by repeating the LPNE process twice in succession to produce, for example, arrays of low-impedance, nanowirenanowire junctions. The resistance, R, of single gold nanowires was measured in situ during electrooxidation in aqueous 0.10 M sulfuric acid. Electrooxidation caused the formation of a gold oxide that is approximately 0.8 monolayers (ML) in thickness at +1.1 V vs saturated mercurous sulfate reference electrode (MSE) based upon coulometry and ex situ X-ray photoelectron spectroscopic analysis. As the gold nanowires were electrooxidized, R increased by an amount that depended on the wire thickness, ranging from

  3. Dietary Patterns: Challenges and Opportunities in Dietary Patterns Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, increasing numbers of researchers have used dietary patterns to characterize the population’s diet and to examine associations between diet and disease outcomes. Many methods, primarily data-driven and index-based approaches, are available for characterizing dietary patterns in a p...

  4. Field theory of pattern identification

    NASA Astrophysics Data System (ADS)

    Agu, Masahiro

    1988-06-01

    Based on the psychological experimental fact that images in mental space are transformed into other images for pattern identification, a field theory of pattern identification of geometrical patterns is developed with the use of gauge field theory in Euclidean space. Here, the ``image'' or state function ψ[χ] of the brain reacting to a geometrical pattern χ is made to correspond to the electron's wave function in Minkowski space. The pattern identification of the pattern χ with the modified pattern χ+Δχ is assumed to be such that their images ψ[χ] and ψ[χ+Δχ] in the brain are transformable with each other through suitable transformation groups such as parallel transformation, dilatation, or rotation. The transformation group is called the ``image potential'' which corresponds to the vector potential of the gauge field. An ``image field'' derived from the image potential is found to be induced in the brain when the two images ψ[χ] and ψ[χ+Δχ] are not transformable through suitable transformation groups or gauge transformations. It is also shown that, when the image field exists, the final state of the image ψ[χ] is expected to be different, depending on the paths of modifications of the pattern χ leading to a final pattern. The above fact is interpreted as a version of the Aharonov and Bohm effect of the electron's wave function [A. Aharonov and D. Bohm, Phys. Rev. 115, 485 (1959)]. An excitation equation of the image field is also derived by postulating that patterns are identified maximally for the purpose of minimizing the number of memorized standard patterns.

  5. Patterning nanocrystals using DNA

    SciTech Connect

    Williams, Shara Carol

    2003-09-01

    One of the goals of nanotechnology is to enable programmed self-assembly of patterns made of various materials with nanometer-sized control. This dissertation describes the results of experiments templating arrangements of gold and semiconductor nanocrystals using 2'-deoxyribonucleic acid (DNA). Previously, simple DNA-templated linear arrangements of two and three nanocrystals structures have been made.[1] Here, we have sought to assemble larger and more complex nanostructures. Gold-DNA conjugates with 50 to 100 bases self-assembled into planned arrangements using strands of DNA containing complementary base sequences. We used two methods to increase the complexity of the arrangements: using branched synthetic doublers within the DNA covalent backbone to create discrete nanocrystal groupings, and incorporating the nanocrystals into a previously developed DNA lattice structure [2][3] that self-assembles from tiles made of DNA double-crossover molecules to create ordered nanoparticle arrays. In the first project, the introduction of a covalently-branched synthetic doubler reagent into the backbone of DNA strands created a branched DNA ''trimer.'' This DNA trimer templated various structures that contained groupings of three and four gold nanoparticles, giving promising, but inconclusive transmission electron microscopy (TEM) results. Due to the presence of a variety of possible structures in the reaction mixtures, and due to the difficulty of isolating the desired structures, the TEM and gel electrophoresis results for larger structures having four particles, and for structures containing both 5 and 10 nm gold nanoparticles were inconclusive. Better results may come from using optical detection methods, or from improved sample preparation. In the second project, we worked toward making two-dimensional ordered arrays of nanocrystals. We replicated and improved upon previous results for making DNA lattices, increasing the size of the lattices to a length greater than

  6. Injury Patterns in Youth Sports.

    ERIC Educational Resources Information Center

    Goldberg, Barry

    1989-01-01

    Presents statistics on injury patterns in youth sports, recommending that physicians who care for young athletes understand the kinds of injuries likely to be sustained. Awareness of injury patterns helps medical professionals identify variables associated with injury, anticipate or prevent injuries, plan medical coverage, and compare individual…

  7. Patterns of Personal Learning Environments

    ERIC Educational Resources Information Center

    Wilson, Scott

    2008-01-01

    The use of design patterns is now well established as an approach within the field of software systems as well as within the field of architecture. An initial effort was made to harness patterns as a tool for elaborating the design of the elements of personal learning environments as part of the University of Bolton's Personal Learning Environment…

  8. Adult Reading Habits and Patterns.

    ERIC Educational Resources Information Center

    Scales, Alice M.; Rhee, Ock

    2001-01-01

    Examines the reading habits and patterns of White and Asian American adults. Hypothesizes that when grouped by demographic variables, participants' responses about their reading habits and patterns would not differ. Concludes that gender, race, and education were predictors for participants' reading habits; education and race were predictors for…

  9. Retirement Patterns and Income Inequality

    ERIC Educational Resources Information Center

    Fasang, Anette Eva

    2012-01-01

    How do social policies shape life courses, and which consequences do different life course patterns hold for individuals? This article engages the example of retirement in Germany and Britain to analyze life course patterns and their consequences for income inequality. Sequence analysis is used to measure retirement trajectories. The liberal…

  10. Capillarity Guided Patterning of Microliquids.

    PubMed

    Kang, Myeongwoo; Park, Woohyun; Na, Sangcheol; Paik, Sang-Min; Lee, Hyunjae; Park, Jae Woo; Kim, Ho-Young; Jeon, Noo Li

    2015-06-01

    Soft lithography and other techniques have been developed to investigate biological and chemical phenomena as an alternative to photolithography-based patterning methods that have compatibility problems. Here, a simple approach for nonlithographic patterning of liquids and gels inside microchannels is described. Using a design that incorporates strategically placed microstructures inside the channel, microliquids or gels can be spontaneously trapped and patterned when the channel is drained. The ability to form microscale patterns inside microfluidic channels using simple fluid drain motion offers many advantages. This method is geometrically analyzed based on hydrodynamics and verified with simulation and experiments. Various materials (i.e., water, hydrogels, and other liquids) are successfully patterned with complex shapes that are isolated from each other. Multiple cell types are patterned within the gels. Capillarity guided patterning (CGP) is fast, simple, and robust. It is not limited by pattern shape, size, cell type, and material. In a simple three-step process, a 3D cancer model that mimics cell-cell and cell-extracellular matrix interactions is engineered. The simplicity and robustness of the CGP will be attractive for developing novel in vitro models of organ-on-a-chip and other biological experimental platforms amenable to long-term observation of dynamic events using advanced imaging and analytical techniques.

  11. The overall patterns of burns

    PubMed Central

    Almoghrabi, A.; Abu Shaban, N.

    2011-01-01

    Summary Burn patterns differ across the whole world and not only in relation to lack of education, overcrowding, and poverty. Cultures, habits, traditions, psychiatric illness, and epilepsy are strongly correlated to burn patterns. However, burns may also occur because of specific religious beliefs and activities, social events and festivals, traditional medical practices, occupational activities, and war. PMID:22639565

  12. Verbal Patterns in Dyadic Interaction.

    ERIC Educational Resources Information Center

    Ayres, Joe; Ivie, Robert L.

    Selected aspects of Kenneth Burke's "dramatistic" model of symbolic interaction were operationalized to describe and compare verbal patterns in transactions between five pairs of friends and five pairs of strangers. Based on Altman and Taylor's social penetration theory, it was predicted that interactants would display verbal patterns unique to…

  13. Patterned Growth in Extreme Environments

    NASA Astrophysics Data System (ADS)

    Curnutt, J.; Gomez, E.; Schubert, K. E.

    2009-12-01

    In this paper, cellular automata are used to model patterned growth of organisms in extreme environments. A brief introduction to cellular automaton modeling is given to assist the reader. Patterned growth of soil surface cyanobacteria and biovermiculation microbial mats in sulfuric acid caves are modeled and simulations conducted. Simulations are compared with actual systems, and future directions are discussed.

  14. Pattern Identification Exercise. ERIC Digest.

    ERIC Educational Resources Information Center

    Amundson, Norm

    Career exploration typically involves the investigation of personal factors: interests, aptitudes, values, and personal style. This digest outlines one counseling method, pattern identification exercise (PIE). PIE starts with past experiences and identifies personal patterns which are relevant to career decisions. A premise of PIE is that…

  15. Developing Linguistic Auditory Memory Patterns.

    ERIC Educational Resources Information Center

    Valett, Robert E.

    1983-01-01

    For learning handicapped children with impaired language associations, patterns, and expressions, this paper summarizes relevant linguistic research and instructional strategies. Linguistic auditory memory pattern exercises and examples are then presented as an integrated multisensory approach which has been found useful by special educators.…

  16. Growing Patterns: Seeing beyond Counting

    ERIC Educational Resources Information Center

    Markworth, Kimberly A.

    2012-01-01

    Over the past two decades, mathematical patterns have been acknowledged as important early components of children's development of algebraic reasoning (NCTM 2000). In particular, growing patterns have attracted significant attention as a context that helps students develop an understanding of functional relationships (Lee and Freiman 2006; Moss et…

  17. Capillarity Guided Patterning of Microliquids.

    PubMed

    Kang, Myeongwoo; Park, Woohyun; Na, Sangcheol; Paik, Sang-Min; Lee, Hyunjae; Park, Jae Woo; Kim, Ho-Young; Jeon, Noo Li

    2015-06-01

    Soft lithography and other techniques have been developed to investigate biological and chemical phenomena as an alternative to photolithography-based patterning methods that have compatibility problems. Here, a simple approach for nonlithographic patterning of liquids and gels inside microchannels is described. Using a design that incorporates strategically placed microstructures inside the channel, microliquids or gels can be spontaneously trapped and patterned when the channel is drained. The ability to form microscale patterns inside microfluidic channels using simple fluid drain motion offers many advantages. This method is geometrically analyzed based on hydrodynamics and verified with simulation and experiments. Various materials (i.e., water, hydrogels, and other liquids) are successfully patterned with complex shapes that are isolated from each other. Multiple cell types are patterned within the gels. Capillarity guided patterning (CGP) is fast, simple, and robust. It is not limited by pattern shape, size, cell type, and material. In a simple three-step process, a 3D cancer model that mimics cell-cell and cell-extracellular matrix interactions is engineered. The simplicity and robustness of the CGP will be attractive for developing novel in vitro models of organ-on-a-chip and other biological experimental platforms amenable to long-term observation of dynamic events using advanced imaging and analytical techniques. PMID:25678019

  18. Biomolecular Patterning via Photocatalytic Lithography

    SciTech Connect

    Bearinger, J P; Hiddessen, A L; Wu, K J; Christian, A T; Dugan, L C; Stone, G; Camarero, J; Hinz, A K; Hubbell, J A

    2005-02-18

    We have developed a novel method for patterning surface chemistry: Photocatalytic Lithography. This technique relies on inexpensive stamp materials and light; it does not necessitate mass transport or specified substrates, and the wavelength of light should not limit feature resolution. We have demonstrated the utility of this technique through the patterning of proteins, single cells and bacteria.

  19. Method of patterning an aerogel

    DOEpatents

    Reed, Scott T.

    2012-07-24

    A method for producing a pattern in an aerogel disposed as a coating on a substrate comprises exposing the aerogel coating to the vapors of a hydrophobic silane compound, masking the aerogel coating with a shadow photomask and irradiating the aerogel coating with ultraviolet (UV) irradiation. The exposure to UV through the shadow mask creates a pattern of hydrophobic and hydrophilic regions in the aerogel coating. Etching away the hydrophilic regions of the aerogel coating, preferably with a 1 molar solution of sodium hydroxide, leaves the unwetted and unetched hydrophobic regions of the aerogel layer on the substrate, replicating the pattern of the photomask. The hydrophobic aerogel pattern can be further exposed to UV irradiation if desired, to create a hydrophilic aerogel pattern.

  20. Patterning by area selective oxidation

    SciTech Connect

    Nam, Chang-Yong; Kamcev, Jovan; Black, Charles T.; Grubbs, Robert

    2015-12-29

    Technologies are described for methods for producing a pattern of a material on a substrate. The methods may comprise receiving a patterned block copolymer on a substrate. The patterned block copolymer may include a first polymer block domain and a second polymer block domain. The method may comprise exposing the patterned block copolymer to a light effective to oxidize the first polymer block domain in the patterned block copolymer. The method may comprise applying a precursor to the block copolymer. The precursor may infuse into the oxidized first polymer block domain and generate the material. The method may comprise applying a removal agent to the block copolymer. The removal agent may be effective to remove the first polymer block domain and the second polymer block domain from the substrate, and may not be effective to remove the material in the oxidized first polymer block domain.

  1. Patterning and templating for nanoelectronics.

    PubMed

    Galatsis, Kosmas; Wang, Kang L; Ozkan, Mihri; Ozkan, Cengiz S; Huang, Yu; Chang, Jane P; Monbouquette, Harold G; Chen, Yong; Nealey, Paul; Botros, Youssry

    2010-02-01

    The semiconductor industry will soon be launching 32 nm complementary metal oxide semiconductor (CMOS) technology node using 193 nm lithography patterning technology to fabricate microprocessors with more than 2 billion transistors. To ensure the survival of Moore's law, alternative patterning techniques that offer advantages beyond conventional top-down patterning are aggressively being explored. It is evident that most alternative patterning techniques may not offer compelling advantages to succeed conventional top-down lithography for silicon integrated circuits, but alternative approaches may well indeed offer functional advantages in realising next-generation information processing nanoarchitectures such as those based on cellular, bioinsipired, magnetic dot logic, and crossbar schemes. This paper highlights and evaluates some patterning methods from the Center on Functional Engineered Nano Architectonics in Los Angeles and discusses key benchmarking criteria with respect to CMOS scaling.

  2. Thermography pattern analysis and separation

    NASA Astrophysics Data System (ADS)

    Gao, Bin; Bai, Libing; Woo, W. L.; Tian, Guiyun

    2014-06-01

    Analysis of thermography spatial-transient patterns has considerable potential to enable automatic identification and quantification of defects in non-destructive testing and evaluation. This Letter proposes a non-negative pattern separation model for eddy current pulsed thermography to automatically extract important spatial and time patterns according to the transient thermal sequences without any pre-training or prior knowledge. In particular, the method is scale-invariant, such that large differences in surface emissivity, hot spots, and cool areas with dynamic range of thermal contrast can be extracted. Finally, an artificial slot in a steel sample with shining, black strip on the surface is tested to validate the proposed method.

  3. Temporal pattern processing in songbirds.

    PubMed

    Comins, Jordan A; Gentner, Timothy Q

    2014-10-01

    Understanding how the brain perceives, organizes and uses patterned information is directly related to the neurobiology of language. Given the present limitations, such knowledge at the scale of neurons, neural circuits and neural populations can only come from non-human models, focusing on shared capacities that are relevant to language processing. Here we review recent advances in the behavioral and neural basis of temporal pattern processing of natural auditory communication signals in songbirds, focusing on European starlings. We suggest a general inhibitory circuit for contextual modulation that can act to control sensory representations based on patterning rules. PMID:25201176

  4. Turing patterns in multiplex networks

    NASA Astrophysics Data System (ADS)

    Asllani, Malbor; Busiello, Daniel M.; Carletti, Timoteo; Fanelli, Duccio; Planchon, Gwendoline

    2014-10-01

    The theory of patterns formation for a reaction-diffusion system defined on a multiplex is developed by means of a perturbative approach. The interlayer diffusion constants act as a small parameter in the expansion and the unperturbed state coincides with the limiting setting where the multiplex layers are decoupled. The interaction between adjacent layers can seed the instability of a homogeneous fixed point, yielding self-organized patterns which are instead impeded in the limit of decoupled layers. Patterns on individual layers can also fade away due to cross-talking between layers. Analytical results are compared to direct simulations.

  5. A Pattern Theory of Self

    PubMed Central

    Gallagher, Shaun

    2013-01-01

    I argue for a pattern theory of self as a useful way to organize an interdisciplinary approach to discussions of what constitutes a self. According to the pattern theory, a self is constituted by a number of characteristic features or aspects that may include minimal embodied, minimal experiential, affective, intersubjective, psychological/cognitive, narrative, extended, and situated aspects. A pattern theory of self helps to clarify various interpretations of self as compatible or commensurable instead of thinking them in opposition, and it helps to show how various aspects of self may be related across certain dimensions. I also suggest that a pattern theory of self can help to adjudicate (or at least map the differences) between the idea that the self correlates to self-referential processing in the cortical midline structures of the brain and other narrower or wider conceptions of self. PMID:23914173

  6. Waveguides having patterned, flattened modes

    SciTech Connect

    Messerly, Michael J.; Pax, Paul H.; Dawson, Jay W.

    2015-10-27

    Field-flattening strands may be added to and arbitrarily positioned within a field-flattening shell to create a waveguide that supports a patterned, flattened mode. Patterning does not alter the effective index or flattened nature of the mode, but does alter the characteristics of other modes. Compared to a telecom fiber, a hexagonal pattern of strands allows for a three-fold increase in the flattened mode's area without reducing the separation between its effective index and that of its bend-coupled mode. Hexagonal strand and shell elements prove to be a reasonable approximation, and, thus, to be of practical benefit vis-a-vis fabrication, to those of circular cross section. Patterned flattened modes offer a new and valuable path to power scaling.

  7. Detection of Patterns Within Randomness

    NASA Astrophysics Data System (ADS)

    Stoop, Ruedi; Christen, Markus

    The identification of jittered regular signals (="patterns#) embedded in a noisy background is an important and difficult task, particularly in the neurosciences. Traditional methods generally fail to capture such signals. Staircase-like structures in the log-log correlation plot, however, are reliable indicators of such signal components.We provide a number of applications of this method and derive an analytic relationship between the length of the pattern n and the maximal number of steps s(n,m) that are observable at a chosen embedding dimension m. For integer linearly independent patterns and small jitter and noise, the length of the embedded pattern can be calculated from the number of steps. The method is demonstrated to have a huge potential for experimental applications.

  8. Diurnal patterns of blowing sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex process that involves an interaction between solar heating, thermal instability, atmospheric turbulence, wind strength, and surface threshold conditions. During the day, solar heating produces thermal instability, which enhances the convect...

  9. Casting Using A Polystyrene Pattern

    NASA Technical Reports Server (NTRS)

    Vasquez, Peter; Guenther, Bengamin; Vranas, Thomas; Veneris, Peter; Joyner, Michael

    1993-01-01

    New technique for making metal aircraft models saves significant amount of time and effort in comparison with conventional lost-wax method. Produces inexpensive, effective wind-tunnel models. Metal wind-tunnel model cast by use of polystyrene pattern.

  10. Stable Multibubble Sonoluminescence Bubble Patterns

    SciTech Connect

    Posakony, Gerald J.; Greenwood, Lawrence R.; Ahmed, Salahuddin

    2006-06-30

    Multibubble standing wave patterns can be generated from a flat piezoceramic transducer element propagating into water. By adding a second transducer positioned at 90 degrees from the transducer generating the standing wave, a 3-dimensional volume of stable single bubbles can be established. Further, the addition of the second transducer stabilizes the bubble pattern so that individual bubbles may be studied. The size of the bubbles and the separation of the standing waves depend on the frequency of operation. Two transducers, operating at frequencies above 500 kHz, provided the most graphic results for the configuration used in this study. At these frequencies stable bubbles exhibit a bright sonoluminescence pattern. Whereas stable SBSL is well-known, stable MBSL has not been previously reported. This paper includes discussions of the acoustic responses, standing wave patterns, and pictorial results of the separation of individual bubble of sonoluminescence in a multibubble sonoluminescence environment.

  11. Pattern formation in multiplex networks

    PubMed Central

    Kouvaris, Nikos E.; Hata, Shigefumi; Guilera, Albert Díaz-

    2015-01-01

    The advances in understanding complex networks have generated increasing interest in dynamical processes occurring on them. Pattern formation in activator-inhibitor systems has been studied in networks, revealing differences from the classical continuous media. Here we study pattern formation in a new framework, namely multiplex networks. These are systems where activator and inhibitor species occupy separate nodes in different layers. Species react across layers but diffuse only within their own layer of distinct network topology. This multiplicity generates heterogeneous patterns with significant differences from those observed in single-layer networks. Remarkably, diffusion-induced instability can occur even if the two species have the same mobility rates; condition which can never destabilize single-layer networks. The instability condition is revealed using perturbation theory and expressed by a combination of degrees in the different layers. Our theory demonstrates that the existence of such topology-driven instabilities is generic in multiplex networks, providing a new mechanism of pattern formation. PMID:26042606

  12. Capacitance enhancement via electrode patterning

    SciTech Connect

    Ho, Tuan A.; Striolo, Alberto

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  13. Capacitance enhancement via electrode patterning.

    PubMed

    Ho, Tuan A; Striolo, Alberto

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  14. Turing patterns in three dimensions

    NASA Astrophysics Data System (ADS)

    Shoji, Hiroto; Yamada, Kohtaro; Ueyama, Daishin; Ohta, Takao

    2007-04-01

    We investigate three-dimensional Turing patterns in two-component reaction diffusion systems. The FitzHugh-Nagumo equation, the Brusselator, and the Gray-Scott model are solved numerically in three dimensions. Several interconnected structures of domains as well as lamellar, hexagonal, and spherical domains are obtained as stable motionless equilibrium patterns. The relative stability of these structures is studied analytically based on the reduction approximation. The relation with the microphase-separated structures in block copolymers is also discussed.

  15. Monolithic pattern-sensitive detector

    DOEpatents

    Berger, Kurt W.

    2000-01-01

    Extreme ultraviolet light (EUV) is detected using a precisely defined reference pattern formed over a shallow junction photodiode. The reference pattern is formed in an EUV absorber preferably comprising nickel or other material having EUV- and other spectral region attenuating characteristics. An EUV-transmissive energy filter is disposed between a passivation oxide layer of the photodiode and the EUV transmissive energy filter. The device is monolithically formed to provide robustness and compactness.

  16. Grade Organization Patterns. ERS Reporter.

    ERIC Educational Resources Information Center

    American Association of School Administrators, Washington, DC.

    Information regarding grade organization patterns in 449 of the 515 school districts enrolling 12,000 or more pupils is reported in this national survey, which repeated a similar survey made in 1963. Results show that the predominant plan is that which follows the 6-3-3 pattern. Of interest are the four percent rise in the 4-4-4 or 5-3-4 middle…

  17. TOPTRAC: Topical Trajectory Pattern Mining

    PubMed Central

    Kim, Younghoon; Han, Jiawei; Yuan, Cangzhou

    2015-01-01

    With the increasing use of GPS-enabled mobile phones, geo-tagging, which refers to adding GPS information to media such as micro-blogging messages or photos, has seen a surge in popularity recently. This enables us to not only browse information based on locations, but also discover patterns in the location-based behaviors of users. Many techniques have been developed to find the patterns of people's movements using GPS data, but latent topics in text messages posted with local contexts have not been utilized effectively. In this paper, we present a latent topic-based clustering algorithm to discover patterns in the trajectories of geo-tagged text messages. We propose a novel probabilistic model to capture the semantic regions where people post messages with a coherent topic as well as the patterns of movement between the semantic regions. Based on the model, we develop an efficient inference algorithm to calculate model parameters. By exploiting the estimated model, we next devise a clustering algorithm to find the significant movement patterns that appear frequently in data. Our experiments on real-life data sets show that the proposed algorithm finds diverse and interesting trajectory patterns and identifies the semantic regions in a finer granularity than the traditional geographical clustering methods. PMID:26709365

  18. Erosion Patterns on Dissolving Surfaces

    NASA Astrophysics Data System (ADS)

    Cohen, Caroline; Polizzi, Stefano; Berhanu, Michael; Derr, Julien; Courrech Du Pont, Sylvain

    2015-11-01

    The shaping of landscapes results from water or wind erosional processes. Here we focus on dissolution processes. We perform laboratory experiments on hard caramel bodies, which dissolve on a short timescale, compared to geological material such as limestone. We highlight the spontaneous appearance of a dissolution pattern with no external flow. When a tilted hard caramel block dissolves, the syrup (denser than water) sinks in the bath and induces a flow, which results in a pattern on the bottom of the block. First parallel stripes appear, which evolve to transversal scallops in about one hour. The whole pattern moves upstream at a slow velocity. The stripes appearance is due to a buoyancy-driven instability. By varying the density and the viscosity of the bath, we show that the initial wavelengths of the pattern are in agreement with those given by the solutal Rayleigh-Benard number. Later pattern evolution to scallops results from complex interactions between the flow and the topography. Finally we emphasize that similar mechanism of patterns formation can occur in the dissolution of minerals like salt, but also in the shaping of the bottom face of melting icebergs in the cold seas.

  19. Pattern formation in geochemical systems

    NASA Astrophysics Data System (ADS)

    Katsev, Sergei

    2002-08-01

    Compositional patterns are extremely common in natural minerals. While, in many cases, variations in the solid mineral composition reflect the external changes in the environment at the time of the mineral formation, the role of self-organization is increasingly acknowledged. For example, in reaction-transport systems, the patterns may form spontaneously from an unpatterned state at the time of crystal growth and then become preserved by being "frozen" in the solid mineral. In this work, the pattern formation by self-organization is investigated by means of model construction and computer simulations in several minerals from different geologic environments. The impact of environmental noise is investigated on a model of oscillatory zoning in plagioclase feldspar. It is shown that environmental noise can lead to pattern formation such as oscillatory zoning, even when no deterministic periodic solutions exist. Coherence resonance close to the Hopf bifurcation is observed. Oscillatory zoning in barite-celestite system is simulated to quantitatively describe the results of the previously reported nucleation and growth experiments. The zoning is thought to be formed by autocatalytic growth from an aqueous solution. In addition to the description of the reaction-diffusion system in terns of partial and ordinary differential equations, a cellular automata model is proposed for the first time for this oscillatory crystallization type of problems. A quantitative model of banding in Mississippi Valley-type sphalerite is presented. Banded ring-like patterns are shown to arise due to a self-propagating sequence of growth and dissolution (coarsening wave). A two-dimensional model is presented for the first time and the conditions for the pattern generation and preservation are discussed. A number of time series analysis techniques are applied to characterize the compositional patterns observed in natural minerals as well as in the colored rythmites found in the marine clay

  20. Techniques for Specifying Bug Patterns

    SciTech Connect

    Quinlan, D J; Vuduc, R W; Misherghi, G

    2007-04-30

    We present our on-going work to develop techniques for specifying source code signatures of bug patterns. Specifically, we discuss two approaches. The first approach directly analyzes a program in the intermediate representation (IR) of the ROSE compiler infrastructure using ROSE's API. The second analyzes the program using the bddbddb system of Lam, Whaley, et al.. In this approach, we store the IR produced by ROSE as a relational database, express patterns as declarative inference rules on relations in the language Datalog, and bddbddb implements the Datalog programs using binary decision diagram (BDD) techniques. Both approaches readily apply to large-scale applications, since ROSE provides full type analysis, control flow, and other available analysis information. In this paper, we primarily consider bug patterns expressed with respect to the structure of the source code or the control flow, or both. More complex techniques to specify patterns that are functions of data flow properties may be addressed by either of the above approaches, but are not directly treated here. Our Datalog-based work includes explicit support for expressing patterns on the use of the Message Passing Interface (MPI) in parallel distributed memory programs. We show examples of this on-going work as well.

  1. Submicron patterned metal hole etching

    DOEpatents

    McCarthy, Anthony M.; Contolini, Robert J.; Liberman, Vladimir; Morse, Jeffrey

    2000-01-01

    A wet chemical process for etching submicron patterned holes in thin metal layers using electrochemical etching with the aid of a wetting agent. In this process, the processed wafer to be etched is immersed in a wetting agent, such as methanol, for a few seconds prior to inserting the processed wafer into an electrochemical etching setup, with the wafer maintained horizontal during transfer to maintain a film of methanol covering the patterned areas. The electrochemical etching setup includes a tube which seals the edges of the wafer preventing loss of the methanol. An electrolyte composed of 4:1 water: sulfuric is poured into the tube and the electrolyte replaces the wetting agent in the patterned holes. A working electrode is attached to a metal layer of the wafer, with reference and counter electrodes inserted in the electrolyte with all electrodes connected to a potentiostat. A single pulse on the counter electrode, such as a 100 ms pulse at +10.2 volts, is used to excite the electrochemical circuit and perform the etch. The process produces uniform etching of the patterned holes in the metal layers, such as chromium and molybdenum of the wafer without adversely effecting the patterned mask.

  2. How do drumlin patterns evolve?

    NASA Astrophysics Data System (ADS)

    Ely, Jeremy; Clark, Chris; Spagnolo, Matteo; Hughes, Anna

    2016-04-01

    The flow of a geomorphic agent over a sediment bed creates patterns in the substrate composed of bedforms. Ice is no exception to this, organising soft sedimentary substrates into subglacial bedforms. As we are yet to fully observe their initiation and evolution beneath a contemporary ice mass, little is known about how patterns in subglacial bedforms develop. Here we study 36,222 drumlins, divided into 72 flowsets, left behind by the former British-Irish Ice sheet. These flowsets provide us with 'snapshots' of drumlin pattern development. The probability distribution functions of the size and shape metrics of drumlins within these flowsets were analysed to determine whether behaviour that is common of other patterned phenomena has occurred. Specifically, we ask whether drumlins i) are printed at a specific scale; ii) grow or shrink after they initiate; iii) stabilise at a specific size and shape; and iv) migrate. Our results indicate that drumlins initiate at a minimum size and spacing. After initiation, the log-normal distribution of drumlin size and shape metrics suggests that drumlins grow, or possibly shrink, as they develop. We find no evidence for stabilisation in drumlin length, supporting the idea of a subglacial bedform continuum. Drumlin migration is difficult to determine from the palaeo-record. However, there are some indications that a mixture of static and mobile drumlins occurs, which could potentially lead to collisions, cannibalisation and coarsening. Further images of modern drumlin fields evolving beneath ice are required to capture stages of drumlin pattern evolution.

  3. Pattern Formation in Convective Instabilities

    NASA Astrophysics Data System (ADS)

    Friedrich, R.; Bestehorn, M.; Haken, H.

    The present article reviews recent progress in the study of pattern formation in convective instabilities. After a brief discussion of the relevant basic hydrodynamic equations as well as a short outline of the mathematical treatment of pattern formation in complex systems the self-organization of spatial and spatio-temporal structures due to convective instabilities is considered. The formation of various forms of convective patterns arising in the Bénard experiment, i.e. in a horizontal fluid layer heated from below, is discussed. Then the review considers pattern formation in the Bénard instability in spherical geometries. In that case it can be demonstrated how the interaction among several convective cells may lead to time dependent as well as chaotic evolution of the spatial structures. Finally, the convective instability in a binary fluid mixture is discussed. In contrast to the instability in a single component fluid the instability may be oscillatory. In that case convection sets in in the form of travelling wave patterns which in addition to a complicated and chaotic temporal behaviour exhibit more or less spatial irregularity already close to threshold.

  4. Pattern separation in the hippocampus

    PubMed Central

    Yassa, Michael A.; Stark, Craig E. L.

    2011-01-01

    The ability to discriminate among similar experiences is a critical feature of episodic memory. This ability has long been hypothesized to require the hippocampus, with computational models suggesting it is dependent on pattern separation. However, empirical data for the hippocampus’ role in pattern separation was not available until recently. This review summarizes data from electrophysiological recordings, lesion studies, immediate early gene imaging, transgenic mouse models, as well as human functional neuroimaging that provide convergent evidence for the involvement of particular hippocampal subfields in this key process. We discuss the impact of aging and adult neurogenesis on pattern separation, as well as highlight several challenges to linking across species and approaches and suggest future directions for investigation. PMID:21788086

  5. Dissolution patterns on caramel blocks

    NASA Astrophysics Data System (ADS)

    Cohen, Caroline; Derr, Julien; Berhanu, Michael; Courrech Du Pont, Sylvain

    2015-11-01

    We investigate erosion by dissolution processes. We perform laboratory experiments on hard caramel bodies, which dissolve on a short timescale, compared to geological material such as limestone. We put a block of caramel, tilted from the horizontal, in a water tank without flow. The dissolution syrup, which is denser than pure water, sinks and the flow detaching from the surface creates patterns underneath the caramel block. These patterns result from the coupled dynamics of the flow detaching and the eroding surface and are reminiscent of scallops observed in the walls of phreatic cave passages. We investigate the mechanisms of formation of these structures and their evolution depending on several parameters such as the fluid density or the flow velocity. We finally parallel the formation of patterns on melting iceberg.

  6. Helicity patterns on the Sun

    NASA Astrophysics Data System (ADS)

    Pevtsov, A.

    Solar magnetic fields exhibit hemispheric preference for negative (pos- itive) helicity in northern (southern) hemisphere. The hemispheric he- licity rule, however, is not very strong, - the patterns of opposite sign helicity were observed on different spatial scales in each hemisphere. For instance, many individual sunspots exhibit patches of opposite he- licity inside the single polarity field. There are also helicity patterns on scales larger than the size of typical active region. Such patterns were observed in distribution of active regions with abnormal (for a give hemisphere) helicity, in large-scale photospheric magnetic fields and coronal flux systems. We will review the observations of large-scale pat- terns of helicity in solar atmosphere and their possible relationship with (sub-)photospheric processes. The emphasis will be on large-scale pho- tospheric magnetic field and solar corona.

  7. Plant pattern-recognition receptors.

    PubMed

    Zipfel, Cyril

    2014-07-01

    Plants are constantly exposed to would-be pathogens in their immediate environment. Yet, despite relying on innate immunity only, plants are resistant to most microbes. They employ pattern-recognition receptors (PRRs) for sensitive and rapid detection of the potential danger caused by microbes and pests. Plant PRRs are either surface-localized receptor kinases (RKs) or receptor-like proteins (RLPs) containing various ligand-binding ectodomains that perceive pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). In this review, I summarize our current knowledge of plant PRRs and their ligands, illustrating the multiple molecular strategies employed by plant PRRs to activate innate immune signaling to survive.

  8. Pattern nulling by reflector shaping

    NASA Astrophysics Data System (ADS)

    Havens, D. A.

    1983-12-01

    The applicability of adaptive array concepts to continuous aperture antennas was studied and appropriate aperture field distributions for pattern nulling were found from them. The adaptive array weights were found to be useful as discrete points in a continuous distribution. This distribution could then be used in an aperture integration scheme to produce a nulled pattern. Also studied was the use of geometrical optics to calculate the aperture field distribution of an arbitrarily shaped reflector. Under some restrictions, geometrical optics can provide a useful approximation. Constructing the aperture field of a reflector defined by a discrete grid of points using a numerical ray tracing scheme was also investigated. Certain numerical problems were identified. Finally, an attempt was made to implement the nulled pattern by a well known beam shaping method based on geometrical optics principles. This technique was found to be inadequate. More promising techniques for implementing the aperture distributions were suggested but not pursued in this work.

  9. Spatial patterns in ant colonies.

    PubMed

    Theraulaz, Guy; Bonabeau, Eric; Nicolis, Stamatios C; Solé, Ricard V; Fourcassié, Vincent; Blanco, Stéphane; Fournier, Richard; Joly, Jean-Louis; Fernández, Pau; Grimal, Anne; Dalle, Patrice; Deneubourg, Jean-Louis

    2002-07-23

    The origins of large-scale spatial patterns in biology have been an important source of theoretical speculation since the pioneering work by Turing (1952) on the chemical basis of morphogenesis. Knowing how these patterns emerge and their functional role is important to our understanding of the evolution of biocomplexity and the role played by self organization. However, so far, conclusive evidence for local activation-long-range inhibition mechanisms in real biological systems has been elusive. Here a well-defined experimental and theoretical analysis of the pattern formation dynamics exhibited by clustering behavior in ant colonies is presented. These experiments and a simple mathematical model show that these colonies do indeed use this type of mechanism. All microscopic variables have been measured and provide the first evidence, to our knowledge, for this type of self-organized behavior in complex biological systems, supporting early conjectures about its role in the organization of insect societies. PMID:12114538

  10. Pattern Formation on Networks: from Localised Activity to Turing Patterns

    PubMed Central

    McCullen, Nick; Wagenknecht, Thomas

    2016-01-01

    Networks of interactions between competing species are used to model many complex systems, such as in genetics, evolutionary biology or sociology and knowledge of the patterns of activity they can exhibit is important for understanding their behaviour. The emergence of patterns on complex networks with reaction-diffusion dynamics is studied here, where node dynamics interact via diffusion via the network edges. Through the application of a generalisation of dynamical systems analysis this work reveals a fundamental connection between small-scale modes of activity on networks and localised pattern formation seen throughout science, such as solitons, breathers and localised buckling. The connection between solutions with a single and small numbers of activated nodes and the fully developed system-scale patterns are investigated computationally using numerical continuation methods. These techniques are also used to help reveal a much larger portion of of the full number of solutions that exist in the system at different parameter values. The importance of network structure is also highlighted, with a key role being played by nodes with a certain so-called optimal degree, on which the interaction between the reaction kinetics and the network structure organise the behaviour of the system. PMID:27273339

  11. Pattern Formation on Networks: from Localised Activity to Turing Patterns

    NASA Astrophysics Data System (ADS)

    McCullen, Nick; Wagenknecht, Thomas

    2016-06-01

    Networks of interactions between competing species are used to model many complex systems, such as in genetics, evolutionary biology or sociology and knowledge of the patterns of activity they can exhibit is important for understanding their behaviour. The emergence of patterns on complex networks with reaction-diffusion dynamics is studied here, where node dynamics interact via diffusion via the network edges. Through the application of a generalisation of dynamical systems analysis this work reveals a fundamental connection between small-scale modes of activity on networks and localised pattern formation seen throughout science, such as solitons, breathers and localised buckling. The connection between solutions with a single and small numbers of activated nodes and the fully developed system-scale patterns are investigated computationally using numerical continuation methods. These techniques are also used to help reveal a much larger portion of of the full number of solutions that exist in the system at different parameter values. The importance of network structure is also highlighted, with a key role being played by nodes with a certain so-called optimal degree, on which the interaction between the reaction kinetics and the network structure organise the behaviour of the system.

  12. Pattern Formation on Networks: from Localised Activity to Turing Patterns.

    PubMed

    McCullen, Nick; Wagenknecht, Thomas

    2016-01-01

    Networks of interactions between competing species are used to model many complex systems, such as in genetics, evolutionary biology or sociology and knowledge of the patterns of activity they can exhibit is important for understanding their behaviour. The emergence of patterns on complex networks with reaction-diffusion dynamics is studied here, where node dynamics interact via diffusion via the network edges. Through the application of a generalisation of dynamical systems analysis this work reveals a fundamental connection between small-scale modes of activity on networks and localised pattern formation seen throughout science, such as solitons, breathers and localised buckling. The connection between solutions with a single and small numbers of activated nodes and the fully developed system-scale patterns are investigated computationally using numerical continuation methods. These techniques are also used to help reveal a much larger portion of of the full number of solutions that exist in the system at different parameter values. The importance of network structure is also highlighted, with a key role being played by nodes with a certain so-called optimal degree, on which the interaction between the reaction kinetics and the network structure organise the behaviour of the system. PMID:27273339

  13. Pattern Drill. ZE-Diskussion. (Pattern Drill. ZE [Zielsprache Englisch

    ERIC Educational Resources Information Center

    Zielsprache Englisch, 1976

    1976-01-01

    This "Zielsprache Englisch" Discussion consists of 8 articles on pattern drill. They will be found under the authors' names: Freudenstein, R.; Gutschow, H.; Hill, L. A.; Mugglestone, P.; Piepho, H-E; Raasch, A.; Schmitz, A.; Schrand, H. (Text is in German.) (IFS/WGA)

  14. Spatiotemporal Wave Patterns: Information Dynamics

    SciTech Connect

    Mikhail Rabinovich; Lev Tsimring

    2006-01-20

    Pattern formation has traditionally been studied in non-equilibrium physics from the viewpoint of describing the basic structures and their interactions. While this is still an important area of research, the emphasis in the last few years has shifted towards analysis of specific properties of patterns in various complex media. For example, diverse and unexpected phenomena occur in neuro-like media that are characterized by highly non-trivial local dynamics. We carried out an active research program on analysis of spatio-temporal patterns in various physical systems (convection, oscillating fluid layer, soap film), as well as in neuro-like media, with an emphasis on informational aspects of the dynamics. Nonlinear nonequilibrium media and their discrete analogs have a unique ability to represent, memorize, and process the information contained in spatio-temporal patterns. Recent neurophysiological experiments demonstrated a certain universality of spatio-temporal representation of information by neural ensembles. Information processing is also revealed in the spatio-temporal dynamics of cellular patterns in nonequilibrium media. It is extremely important for many applications to study the informational aspects of these dynamics, including the origins and mechanisms of information generation, propagation and storage. Some of our results are: the discovery of self-organization of periodically oscillatory patterns in chaotic heterogeneous media; the analysis of the propagation of the information along a chaotic media as function of the entropy of the signal; the analysis of wave propagation in discrete non-equilibrium media with autocatalytic properties, which simulates the calcium dynamics in cellular membranes. Based on biological experiments we suggest the mechanism by which the spatial sensory information is transferred into the spatio-temporal code in the neural media. We also found a new mechanism of self-pinning in cellular structures and the related phenomenon

  15. Musical patterns for comparative epigenomics.

    PubMed

    Brocks, David

    2015-01-01

    Scientific data has been transformed into music in order to raise awareness in the non-scientific community. While the general public is nowadays familiar with the genetic code, there is still a lack of knowledge regarding epigenetic regulation. By making use of the binary nature of the methylome, we here describe a method that transforms methylation patterns into music. The resulting musical pieces show decent complexity and allow the audible recognition between music and underlying methylation state. This approach might therefore facilitate the recognition of complex methylation patterns and increase awareness for epigenetic regulation in the general public. PMID:26357527

  16. Turing patterns in three dimensions.

    PubMed

    Shoji, Hiroto; Yamada, Kohtaro; Ueyama, Daishin; Ohta, Takao

    2007-04-01

    We investigate three-dimensional Turing patterns in two-component reaction diffusion systems. The FitzHugh-Nagumo equation, the Brusselator, and the Gray-Scott model are solved numerically in three dimensions. Several interconnected structures of domains as well as lamellar, hexagonal, and spherical domains are obtained as stable motionless equilibrium patterns. The relative stability of these structures is studied analytically based on the reduction approximation. The relation with the microphase-separated structures in block copolymers is also discussed. PMID:17500983

  17. Glass strengthening and patterning methods

    DOEpatents

    Harper, David C; Wereszczak, Andrew A; Duty, Chad E

    2015-01-27

    High intensity plasma-arc heat sources, such as a plasma-arc lamp, are used to irradiate glass, glass ceramics and/or ceramic materials to strengthen the glass. The same high intensity plasma-arc heat source may also be used to form a permanent pattern on the glass surface--the pattern being raised above the glass surface and integral with the glass (formed of the same material) by use of, for example, a screen-printed ink composition having been irradiated by the heat source.

  18. Pattern formation in the geosciences

    PubMed Central

    Goehring, Lucas

    2013-01-01

    Pattern formation is a natural property of nonlinear and non-equilibrium dynamical systems. Geophysical examples of such systems span practically all observable length scales, from rhythmic banding of chemical species within a single mineral crystal, to the morphology of cusps and spits along hundreds of kilometres of coastlines. This article briefly introduces the general principles of pattern formation and argues how they can be applied to open problems in the Earth sciences. Particular examples are then discussed, which summarize the contents of the rest of this Theme Issue. PMID:24191107

  19. Pattern transfer using block copolymers.

    PubMed

    Gu, Xiaodan; Gunkel, Ilja; Russell, Thomas P

    2013-10-13

    To meet the increasing demand for patterning smaller feature sizes, a lithography technique is required with the ability to pattern sub-20 nm features. While top-down photolithography is approaching its limit in the continued drive to meet Moore's law, the use of directed self-assembly (DSA) of block copolymers (BCPs) offers a promising route to meet this challenge in achieving nanometre feature sizes. Recent developments in BCP lithography and in the DSA of BCPs are reviewed. While tremendous advances have been made in this field, there are still hurdles that need to be overcome to realize the full potential of BCPs and their actual use.

  20. Fractal dimension of bioconvection patterns

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1990-01-01

    Shallow cultures of the motile algal strain, Euglena gracilis, were concentrated to 2 x 10 to the 6th organisms per ml and placed in constant temperature water baths at 24 and 38 C. Bioconvective patterns formed an open two-dimensional structure with random branches, similar to clusters encountered in the diffusion-limited aggregation (DLA) model. When averaged over several example cultures, the pattern was found to have no natural length scale, self-similar branching, and a fractal dimension (d about 1.7). These agree well with the two-dimensional DLA.

  1. Interactive design of generic chemical patterns.

    PubMed

    Schomburg, Karen T; Wetzer, Lars; Rarey, Matthias

    2013-07-01

    Every medicinal chemist has to create chemical patterns occasionally for querying databases, applying filters or describing functional groups. However, the representations of chemical patterns have been so far limited to languages with highly complex syntax, handicapping the application of patterns. Graphic pattern editors similar to chemical editors can facilitate the work with patterns. In this article, we review the interfaces of frequently used web search engines for chemical patterns. We take a look at pattern editing concepts of standalone chemical editors and finally present a completely new, unpublished graphical approach to pattern design, the SMARTSeditor.

  2. 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…

  3. Computer Simulation of Diffraction Patterns.

    ERIC Educational Resources Information Center

    Dodd, N. A.

    1983-01-01

    Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral…

  4. Peoples, Processes and Patterns: Islam.

    ERIC Educational Resources Information Center

    Gibbons, Joan; And Others

    Designed for use by elementary and secondary teachers but useful to anyone interested in Islamic art, this booklet considers the ways in which design issues have been solved in Islamic cultures, both in the past and the present. The text covers two major areas: aspects of pattern in Islamic weaving and aspects of Islamic tilework. Under weaving…

  5. A Lesson in Number Pattern

    ERIC Educational Resources Information Center

    Fletcher, Rodney

    2008-01-01

    This article presents a guided investigation into the spacial relationships between the centres of the squares in a Fibonacci tiling. It is essentially a lesson in number pattern, but includes work with surds, coordinate geometry, and some elementary use of complex numbers. The investigation could be presented to students in a number of ways…

  6. Space Biology: Patterns of Life

    ERIC Educational Resources Information Center

    Salisbury, Frank B.

    1971-01-01

    Present knowledge about Mars is compared with past beliefs about the planet. Biological experiments that indicate life may exist on Mars are interpreted. Life patterns or biological features that might be postulated for extraterrestrial life are presented at the molecular, cellular, organism, and ecosystem levels. (DS)

  7. Design Patterns for Complex Learning

    ERIC Educational Resources Information Center

    Rohse, Shanta; Anderson, Terry

    2006-01-01

    A complex view of learning recognises that learning cannot be pre-determined by teaching, but is as much defined by circumstances and context as pre-defined learning objectives. Learning designs that accept uncertainty help us to envision classrooms and curricula that are open, dynamic and innovative. Architect Christopher Alexander's patterns and…

  8. Champagne Patterns and Lake Nyos

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Carbon dioxide bubbles in a glass of champagne rise to the surface in fine threads, which are made of bubble groupings that change over time. Researchers from French and Brazilian universities have produced a new model that accounts for the patterns in strings of bubbles in champagne and other effervescent fluids. The research appears in Physical…

  9. Spatial vegetation patterns and desertification

    NASA Astrophysics Data System (ADS)

    Rietkerk, M.; Kéfi, S.

    2009-04-01

    Arid ecosystems are amongst the most sensitive ecosystems to human pressure and climate change, and are liable to undergo desertification. This is a main concern because this may occur abruptly and irreversibly, with concomitant losses of ecological and economic resources. Such ecosystem shifts have been theoretically attributed to positive feedback and alternative stable ecosystem states. However, verifications and predictive power with respect to such ecosystem dynamics are lacking for spatially extensive ecosystems. Therefore, management and recovery strategies against desertification for arid ecosystems are difficult to achieve. Theoretical models predict that so-called regular vegetation patterns observed in large areas in arid ecosystems world-wide are a result of spatial self-organization, and the shapes of the patterns are associated with approaching desertification thresholds. Also, patch-size distribution of the vegetation in various arid ecosystems follows a power law, and consistent deviations from power laws occur if grazing pressure is high. Model analysis suggests that such deviations from power laws may be a warning signal for the onset of desertification, independent of the vegetation cover. So, spatial patterns of vegetation, not cover, can be used to assess the vulnerability of arid ecosystems to increased human pressure or ongoing climate change. Common ecological mechanisms that account for these patterns are scale-dependent feedback and local facilitation. Our results are relevant to identify areas that are vulnerable to desertification in the face of increased human pressure and ongoing global climate change, as well as for the restoration of areas that are already degraded.

  10. Monolingual and Bilingual Development Patterns.

    ERIC Educational Resources Information Center

    Johnson, Teresa H.

    Similarities and differences in language acquisition and variations in patterns of language dominance were studied with three four-year-old girls. The ideoqraphic study of child speech involved a monolingual English-speaking child, a monolingual Spanish-speaking child, and a bilingual English-Spanish-speaking child. The following measures were…

  11. Diurnal patterns of blowing sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex process that involves the interaction between the sun, wind, and earth. During the day, solar heating produces thermal instability, which enhances the convective mixing of high momentum winds from the upper levels of the atmosphere to the s...

  12. The inheritance of fingerprint patterns.

    PubMed Central

    Slatis, H M; Katznelson, M B; Bonné-Tamir, B

    1976-01-01

    Analysis of the fingerprints of 571 members of the Habbanite isolate suggest inherited patterns and pattern sequences. A genetic theory has been developed; it assumes that the basic fingerprint pattern sequence is all ulnar loops and that a variety of genes cause deviations from this pattern sequence. Genes that have been proposed include: (1) a semidominant gene for whorls on the thumbs (one homozygote has whorls on both thumbs, the other has ulnar loops on both thumbs and the heterozygote usually has two ulnar loops or one ulnar loop and one whorl); (2) a semidominant gene for whorls on the ring fingers which acts like the gene for whorls on the thumbs; (3) a dominant gene for arches on the thumbs and often on other fingers; (4) one or more dominant genes for arches on the fingers; (5) a dominant gene for whorls on all fingers except for an ulnar loop on the middle finger; (6) a dominant gene for radial loops on the index fingers, frequently associated with an arch on the middle fingers; and (7) a recessive gene for radial loops on the ring and little fingers. These genes may act independently or may show epistasis. PMID:1266855

  13. Error Patterns of Bilingual Readers.

    ERIC Educational Resources Information Center

    Gonzalez, Phillip C.; Elijah, David V.

    1979-01-01

    In a study of developmental reading behaviors, errors of 75 Spanish-English bilingual students (grades 2-9) on the McLeod GAP Comprehension Test were categorized in an attempt to ascertain a pattern of language difficulties. Contrary to previous research, bilingual readers minimally used native language cues in reading second language materials.…

  14. School Dropouts: Patterns and Policies.

    ERIC Educational Resources Information Center

    Natriello, Gary, Ed.

    This book collects articles that examine the patterns of dropping out evident among American youth, and the policies developed and implemented to reduce the incidence of dropping out. The following chapters (and their authors) are included: (1) Introduction (G. Natriello); (2) Can We Help Dropouts? Thinking about the Undoable (D. Mann); (3) Large…

  15. Patterning via optical saturable transitions

    NASA Astrophysics Data System (ADS)

    Cantu, Precious

    For the past 40 years, optical lithography has been the patterning workhorse for the semiconductor industry. However, as integrated circuits have become more and more complex, and as device geometries shrink, more innovative methods are required to meet these needs. In the far-field, the smallest feature that can be generated with light is limited to approximately half the wavelength. This, so called far-field diffraction limit or the Abbe limit (after Prof. Ernst Abbe who first recognized this), effectively prevents the use of long-wavelength photons >300nm from patterning nanostructures <100nm. Even with a 193nm laser source and extremely complicated processing, patterns below ˜20nm are incredibly challenging to create. Sources with even shorter wavelengths can potentially be used. However, these tend be much more expensive and of much lower brightness, which in turn limits their patterning speed. Multi-photon reactions have been proposed to overcome the diffraction limit. However, these require very large intensities for modest gain in resolution. Moreover, the large intensities make it difficult to parallelize, thus limiting the patterning speed. In this dissertation, a novel nanopatterning technique using wavelength-selective small molecules that undergo single-photon reactions, enabling rapid top-down nanopatterning over large areas at low-light intensities, thereby allowing for the circumvention of the far-field diffraction barrier is developed and experimentally verified. This approach, which I refer to as Patterning via Optical Saturable Transitions (POST) has the potential for massive parallelism, enabling the creation of nanostructures and devices at a speed far surpassing what is currently possible with conventional optical lithographic techniques. The fundamental understanding of this technique goes beyond optical lithography in the semiconductor industry and is applicable to any area that requires the rapid patterning of large-area two or three

  16. Metacommunity patterns in larval odonates.

    PubMed

    McCauley, Shannon J; Davis, Christopher J; Relyea, Rick A; Yurewicz, Kerry L; Skelly, David K; Werner, Earl E

    2008-11-01

    The growth of metacommunity ecology as a subdiscipline has increased interest in how processes at different spatial scales structure communities. However, there is still a significant knowledge gap with respect to relating the action of niche- and dispersal-assembly mechanisms to observed species distributions across gradients. Surveys of the larval dragonfly community (Odonata: Anisoptera) in 57 lakes and ponds in southeast Michigan were used to evaluate hypotheses about the processes regulating community structure in this system. We considered the roles of both niche- and dispersal-assembly processes in determining patterns of species richness and composition across a habitat gradient involving changes in the extent of habitat permanence, canopy cover, area, and top predator type. We compared observed richness patterns and species distributions in this system to patterns predicted by four general community models: species sorting related to adaptive trade-offs, a developmental constraints hypothesis, dispersal assembly, and a neutral community assemblage. Our results supported neither the developmental constraints nor the neutral-assemblage models. Observed patterns of richness and species distributions were consistent with patterns expected when adaptive tradeoffs and dispersal-assembly mechanisms affect community structure. Adaptive trade-offs appeared to be important in limiting the distributions of species which segregate across the habitat gradient. However, dispersal was important in shaping the distributions of species that utilize habitats with a broad range of hydroperiods and alternative top predator types. Our results also suggest that the relative importance of these mechanisms may change across this habitat gradient and that a metacommunity perspective which incorporates both niche- and dispersal-assembly processes is necessary to understand how communities are organized. PMID:18781330

  17. Applications of inverse pattern projection

    NASA Astrophysics Data System (ADS)

    Li, Wansong; Bothe, Thorsten; Kalms, Michael K.; von Kopylow, Christoph; Jueptner, Werner P. O.

    2003-05-01

    Fast and robust 3D quality control as well as fast deformation measurement is of particular importance for industrial inspection. Additionally a direct response about measured properties is desired. Therefore, robust optical techniques are needed which use as few images as possible for measurement and visualize results in an efficient way. One promising technique for this aim is the inverse pattern projection which has the following advantages: The technique codes the information of a preceding measurement into the projected inverse pattern. Thus, it is possible to do differential measurements using only one camera frame for each state. Additionally, the results are optimized straight fringes for sampling which are independent of the object curvature. The hardware needs are low as just a programmable projector and a standard camera are necessary. The basic idea of inverse pattern projection, necessary algorithms and found optimizations are demonstrated, roughly. Evaluation techniques were found to preserve a high quality phase measurement under imperfect conditions. The different application fields can be sorted out by the type of pattern used for inverse projection. We select two main topics for presentation. One is the incremental (one image per state) deformation measurement which is a promising technique for high speed deformation measurements. A video series of a wavering flag with projected inverse pattern was evaluated to show the complete deformation series. The other application is the optical feature marking (augmented reality) that allows to map any measured result directly onto the object under investigation. Any properties can be visualized directly on the object"s surface which makes inspections easier than with use of a separated indicating device. The general ability to straighten any kind of information on 3D surfaces is shown while preserving an exact mapping of camera image and object parts. In many cases this supersedes an additional monitor to

  18. Erosion patterns on dissolving blocks

    NASA Astrophysics Data System (ADS)

    Courrech du Pont, Sylvain; Cohen, Caroline; Derr, Julien; Berhanu, Michael

    2016-04-01

    Patterns in nature are shaped under water flows and wind action, and the understanding of their morphodynamics goes through the identification of the physical mechanisms at play. When a dissoluble body is exposed to a water flow, typical patterns with scallop-like shapes may appear [1,2]. These shapes are observed on the walls of underground rivers or icebergs. We experimentally study the erosion of dissolving bodies made of salt, caramel or ice into water solutions without external flow. The dissolving mixture, which is created at the solid/liquid interface, undergoes a buoyancy-driven instability comparable to a Rayleigh-Bénard instability so that the dissolving front destabilizes into filaments. This mechanism yields to spatial variations of solute concentration and to differential dissolution of the dissolving block. We first observe longitudinal stripes with a well defined wavelength, which evolve towards chevrons and scallops that interact and move again the dissolving current. Thanks to a careful analysis of the competing physical mechanisms, we propose scaling laws, which account for the characteristic lengths and times of the early regime in experiments. The long-term evolution of patterns is understood qualitatively. A close related mechanism has been proposed to explain structures observed on the basal boundary of ice cover on brakish lakes [3] and we suggest that our experiments are analogous and explain the scallop-like patterns on iceberg walls. [1] P. Meakin and B. Jamtveit, Geological pattern formation by growth and dissolution in aqueous systems, Proc. R. Soc. A 466, 659-694 (2010). [2] P.N. Blumberg and R.L. Curl, Experimental and theoretical studies of dissolution roughness, J. Fluid Mech. 65, 735-751 (1974). [3] L. Solari and G. Parker, Morphodynamic modelling of the basal boundary of ice cover on brakish lakes, J.G.R. 118, 1432-1442 (2013).

  19. A Repeat Look at Repeating Patterns

    ERIC Educational Resources Information Center

    Markworth, Kimberly A.

    2016-01-01

    A "repeating pattern" is a cyclical repetition of an identifiable core. Children in the primary grades usually begin pattern work with fairly simple patterns, such as AB, ABC, or ABB patterns. The unique letters represent unique elements, whereas the sequence of letters represents the core that is repeated. Based on color, shape,…

  20. Ecophysiological patterns in field crops

    NASA Astrophysics Data System (ADS)

    Langensiepen, M.; Stadler, A.; Kupisch, M.; Ewert, F.

    2013-12-01

    Soils in agricultural fields are often characterized by different degrees of heterogeneities in physical, chemical, and biological conditions. Plants may respond distinctively to these patterns by adjusting ecophysiological processes and architectural growth at different organizational, spatial, and temporal, scales. The purpose of this research was to quantify the heterogeneity in physical soil conditions at a key research field of the Transregio 32 collaborative research center (www.tr32.de) near Jülich (50°52' N , 6° 27‧ E) and to characterize their effects on the magnitudes of photosynthesis, transpiration, and sap-flow rates at the leaf, point, and field scales. Such information is a necessary prerequisite for deciding which theoretical model representations should be taken for quantifying these processes and which routines are appropriate for scaling the chosen model types from point to field level and beyond. Outputs from the gas-exchange and sap-flow equipment were initially validated against independent eddy-covariance measurements of H2O and CO2 fluxes in a uniform wheat-field 10 km apart from the research site to ensure good data quality. The actual experiment was subsequently carried during two wheat growing years (2010/11 and 2011/12) at the actual field site in. Electromagnetic induction (EMI) and soil measurements were carried out to quantify heterogeneities in soil physical conditions which showed distinctive patterns. These patterns were reflected in observed spatial and temporal patterns of leaf area development and biomass growth which were carried out at bi-weekly intervals. Surprisingly, spatial patterns in soil heterogeneity did not significantly affect field patterns of stomatal conductance, leaf gas-exchange and sap-flow which reflects whole-plant transpiration, whereas canopy fluxes of H2O and CO2 were strongly distinct in different field locations. Morphological adaptations at the plant and canopy levels to soil heterogeneity were

  1. Magnetic Assisted Colloidal Pattern Formation

    NASA Astrophysics Data System (ADS)

    Yang, Ye

    Pattern formation is a mysterious phenomenon occurring at all scales in nature. The beauty of the resulting structures and myriad of resulting properties occurring in naturally forming patterns have attracted great interest from scientists and engineers. One of the most convenient experimental models for studying pattern formation are colloidal particle suspensions, which can be used both to explore condensed matter phenomena and as a powerful fabrication technique for forming advanced materials. In my thesis, I have focused on the study of colloidal patterns, which can be conveniently tracked in an optical microscope yet can also be thermally equilibrated on experimentally relevant time scales, allowing for ground states and transitions between them to be studied with optical tracking algorithms. In particular, I have focused on systems that spontaneously organize due to particle-surface and particle-particle interactions, paying close attention to systems that can be dynamically adjusted with an externally applied magnetic or acoustic field. In the early stages of my doctoral studies, I developed a magnetic field manipulation technique to quantify the adhesion force between particles and surfaces. This manipulation technique is based on the magnetic dipolar interactions between colloidal particles and their "image dipoles" that appear within planar substrate. Since the particles interact with their own images, this system enables massively parallel surface force measurements (>100 measurements) in a single experiment, and allows statistical properties of particle-surface adhesion energies to be extracted as a function of loading rate. With this approach, I was able to probe sub-picoNewton surface interactions between colloidal particles and several substrates at the lowest force loading rates ever achieved. In the later stages of my doctoral studies, I focused on studying patterns formed from particle-particle interaction, which serve as an experimental model of

  2. Maladaptive eating patterns in children.

    PubMed

    Wildermuth, Sarah A; Mesman, Glenn R; Ward, Wendy L

    2013-01-01

    Given the increasing frequency of obesity and related maladaptive eating patterns in pediatric populations, health care professionals in a variety of settings must find ways to treat persons who are obese and have maladaptive eating patterns. The authors summarized literature related to binge eating disorder, boredom eating, emotional eating, and night eating syndrome and developed educational handouts designed for children/adolescents and their families who present with these eating problems. These educational handouts may be used by primary care physicians, psychologists, psychiatrists, nurses, and other specialists in medical settings. They are free for use in educational purposes, with permission from the authors, but are not intended to replace appropriate health care and follow-up.

  3. Broadband patterned magnetic microwave absorber

    SciTech Connect

    Li, Wei; Wu, Tianlong; Wang, Wei; Guan, Jianguo; Zhai, Pengcheng

    2014-07-28

    It is a tough task to greatly improve the working bandwidth for the traditional flat microwave absorbers because of the restriction of available material parameters. In this work, a simple patterning method is proposed to drastically broaden the absorption bandwidth of a conventional magnetic absorber. As a demonstration, an ultra-broadband microwave absorber with more than 90% absorption in the frequency range of 4–40 GHz is designed and experimentally realized, which has a thin thickness of 3.7 mm and a light weight equivalent to a 2-mm-thick flat absorber. In such a patterned absorber, the broadband strong absorption is mainly originated from the simultaneous incorporation of multiple λ/4 resonances and edge diffraction effects. This work provides a facile route to greatly extend the microwave absorption bandwidth for the currently available absorbing materials.

  4. Pattern formation in quantum networks

    NASA Astrophysics Data System (ADS)

    Kim, Ilki; Mahler, Günter

    1999-03-01

    We investigate the iteration of a sequence of local and pair unitary transformations (quantum gate approximation), which can be interpreted to result from a Turing-head (pseudo-spin S) rotating along a closed Turing-tape (M additional pseudo-spins). The dynamical evolution of the Bloch-vector of S, which can be decomposed into 2M primitive pure state Turing-head trajectories, gives rise to fascinating geometrical patterns reflecting the entanglement between head and tape. For specific initial states ("input"), these patterns ("output") can be easily calculated for any tape size. We thus show intuitive examples for quantum parallelism and, at the same time, means for local testing of quantum network dynamics.

  5. Gene Insertion Patterns and Sites

    NASA Astrophysics Data System (ADS)

    Vain, Philippe; Thole, Vera

    During the past 25 years, the molecular analysis of transgene insertion patterns and sites in plants has greatly contributed to our understanding of the mechanisms underlying transgene integration, expression, and stability in the nuclear genome. Molecular characterization is also an essential step in the safety assessment of genetically modified crops. This chapter describes the standard experimental procedures used to analyze transgene insertion patterns and loci in cereals and grasses transformed using Agrobacterium tumefaciens or direct transfer of DNA. Methods and protocols enabling the determination of the number and configuration of transgenic loci via a combination of inheritance studies, polymerase chain reaction, and Southern analyses are presented. The complete characterization of transgenic inserts in plants is, however, a holistic process relying on a wide variety of experimental approaches. In this chapter, these additional approaches are not detailed but references to relevant bibliographic records are provided.

  6. Historic Patterns in Astronomical Incomprehension

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia

    2006-04-01

    Because astronomy is old, it has had a chance to display some very prolonged battles in the war between ideas (theories) and observations (data) that we call science. It is possible to discern two major patterns -- data leading vs. ideas leading -- and very short to very long durations of the events that eventually led to understanding. A variant has the community converging with vigor around a wrong answer (gamma ray bursters are a recent example). The talk will explore some of the author's favorite examples of each pattern. These include the rapid basic understanding of quasars and pulsars vs. the extremely long times required to figure out the solar corona and pulsating variable stars. Among the cases where theory has led via prediction, discovery was almost immediate for 21 cm radio emission and superluminal motion in quasars, but very slow for fluctuations in the cosmic microwave background radiation, certain kinds of polarization, and (surely a record never to be broken) heliocentric parallax.

  7. 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.

  8. Chromatin pattern by variogram analysis.

    PubMed

    Diaz, G; Zucca, A; Setzu, M D; Cappai, C

    1997-11-01

    Many cytological processes such as cell proliferation, differentiation, transformation, apoptosis, etc., are accompanied by specific chromatin changes, usually identified on the basis of the relative content of euchromatin and heterochromatin. In order to achieve a quantitative, non-subjective evaluation of the chromatin pattern, two different approaches may be undertaken, one consisting in the analysis of the several morphological features of chromatin grains (size, shape, density, arrangement, and distribution), and the second consisting in the analysis of the chromatin globally considered as a coherent texture. Although the second approach appears to be simpler and more suitable, methods of texture analysis--including those specifically designed for the analysis of the chromatin pattern--are rarely applied due mainly to the unsuitability of sampling procedures and the excessive crypticism of results. As an alternative to traditional texture analysis, we suggest a method supported by a sound mathematical theory and approximately 30 years of applications in the field of geostatistics. The method, called variogram, analyzes the intrinsic structure of data sampled at different distance intervals and directions, and outputs easily understandable results. Recently, variogram analysis has successfully been exported from geostatistics to other fields (for example, ecology and epidemiology) that make use of spatially referenced variables. Based on the fact that pixels represent a perfect array of data ordered at regular distance intervals and directions, the variogram can be adopted to explore nuclear images and recognize chromatin patterns. Variograms of different nuclei can be summarized by multivariate methods without the need of previous standardization of data. This allows comparison and discrimination of chromatin patterns from mixed cell populations. Preliminary data obtained from young neurons undergoing massive apoptosis reveal a self-consistent map of nuclear

  9. An Efficient Pattern Matching Algorithm

    NASA Astrophysics Data System (ADS)

    Sleit, Azzam; Almobaideen, Wesam; Baarah, Aladdin H.; Abusitta, Adel H.

    In this study, we present an efficient algorithm for pattern matching based on the combination of hashing and search trees. The proposed solution is classified as an offline algorithm. Although, this study demonstrates the merits of the technique for text matching, it can be utilized for various forms of digital data including images, audio and video. The performance superiority of the proposed solution is validated analytically and experimentally.

  10. Raman Radiation Patterns of Graphene

    PubMed Central

    2015-01-01

    We report the angular distribution of the G and 2D Raman scattering from graphene on glass by detecting back focal plane patterns. The G Raman emission can be described by a superposition of two incoherent orthogonal point dipoles oriented in the graphene plane. Due to double resonant Raman scattering, the 2D emission can be represented by the sum of either three incoherent dipoles oriented 120° with respect to each other, or two orthogonal incoherent ones with a 3:1 weight ratio. Parameter-free calculations of the G and 2D intensities are in excellent agreement with the experimental radiation patterns. We show that the 2D polarization ratio and the 2D/G intensity ratio depend on the numerical aperture of the microscope objective. This is due to the depolarization of the emission and excitation light when graphene is on a dielectric substrate, as well as to tight focusing. The polarization contrast decreases substantially for increasing collection angle, due to polarization mixing caused by the air-dielectric interface. This also influences the intensity ratio I(2D)/I(G), a crucial quantity for estimating the doping in graphene. Our results are thus important for the quantitative analysis of the Raman intensities in confocal microscopy. In addition, they are relevant for understanding the influence of signal enhancing plasmonic antenna structures, which typically modify the sample’s radiation pattern. PMID:26651030

  11. 'Festoon' Pattern in Meridiani Outcrop

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Close-Up of 'Festoon' Pattern

    This image from the panoramic camera on NASA's Mars Exploration Rover Opportunity shows the best examples yet seen in Meridiani Planum outcrop rocks of well-preserved, fine-scale layering and what geologists call 'cross-lamination.' Opportunity acquired this image of a rock called 'Overgaard' at the edge of 'Erebus Crater' during the rover's 690th Martian day (Jan. 2, 2006).

    The uppermost part of the rock, just above the center of the image and in the enlargement at top, shows distinctive centimeter-sized, smile-shaped features that sedimentary geologists call 'festoons.' The detailed geometric patterns of such nested sets of concave-upward layers in sedimentary rocks imply the presence of small, sinuous sand ripples that form only in water on Earth. Similar festoon cross-lamination and other distinctive sedimentary layer patterns are also visible in the lower parts of the rock, just left of center, and in other rocks near the rim of Erebus. Essentially, these features are the preserved remnants of tiny (centimeter-sized) underwater sand dunes formed long ago by waves in shallow water on the surface of Mars.

    This image was obtained in the late afternoon (4:15 p.m. local solar time) using the panoramic camera's 430 nanometer filter.

  12. Visualizing Dynamic Bitcoin Transaction Patterns.

    PubMed

    McGinn, Dan; Birch, David; Akroyd, David; Molina-Solana, Miguel; Guo, Yike; Knottenbelt, William J

    2016-06-01

    This work presents a systemic top-down visualization of Bitcoin transaction activity to explore dynamically generated patterns of algorithmic behavior. Bitcoin dominates the cryptocurrency markets and presents researchers with a rich source of real-time transactional data. The pseudonymous yet public nature of the data presents opportunities for the discovery of human and algorithmic behavioral patterns of interest to many parties such as financial regulators, protocol designers, and security analysts. However, retaining visual fidelity to the underlying data to retain a fuller understanding of activity within the network remains challenging, particularly in real time. We expose an effective force-directed graph visualization employed in our large-scale data observation facility to accelerate this data exploration and derive useful insight among domain experts and the general public alike. The high-fidelity visualizations demonstrated in this article allowed for collaborative discovery of unexpected high frequency transaction patterns, including automated laundering operations, and the evolution of multiple distinct algorithmic denial of service attacks on the Bitcoin network. PMID:27441715

  13. Crack patterns over uneven substrates.

    PubMed

    Nandakishore, Pawan; Goehring, Lucas

    2016-02-28

    Cracks in thin layers are influenced by what lies beneath them. From buried craters to crocodile skin, crack patterns are found over an enormous range of length scales. Regardless of absolute size, their substrates can dramatically influence how cracks form, guiding them in some cases, or shielding regions from them in others. Here we investigate how a substrate's shape affects the appearance of cracks above it, by preparing mud cracks over sinusoidally varying surfaces. We find that as the thickness of the cracking layer increases, the observed crack patterns change from wavy to ladder-like to isotropic. Two order parameters are introduced to measure the relative alignment of these crack networks, and, along with Fourier methods, are used to characterise the transitions between crack pattern types. Finally, we explain these results with a model, based on the Griffith criteria of fracture, that identifies the conditions for which straight or wavy cracks will be seen, and predicts how well-ordered the cracks will be. Our metrics and results can be applied to any situation where connected networks of cracks are expected, or found. PMID:26762761

  14. Fractal patterns from chemical dissolution

    NASA Astrophysics Data System (ADS)

    Daccord, Gérard; Lenormand, Roland

    1987-01-01

    The highly ramified patterns1,2 produced by the flow of a reactive fluid through a soluble porous medium have never been quantitatively described. The theoretical understanding of this phenomenon is limited to very simple conditions (such as the flow of a liquid through a; capillary3) due to the complexity of the coupling between the chemical reaction and the fluid flow. We show here that the dissolution patterns (DP) obtained experimentally by injecting water through pure plaster are fractal, for different geometries of the samples. In two dimensions, these DP are remarkably'similar to patterns associated with diffusion-limited aggregation4-6 (DLA), that is, dielectric breakdown7, viscous fingering8,9 and diffusion-limited polymerization10. In three dimensions, we compare them with DLA clusters grown in the same boundary conditions and find a good qualitative and quantitative similarity. These results should be of interest in different areas where chemical dissolution of porous media by a flowing fluid occurs, for example, in nature (the formation of caves) and in industry (in the oil industry where acids are routinely injected into oil reservoirs).

  15. Vascular pattern formation in plants.

    PubMed

    Scarpella, Enrico; Helariutta, Ykä

    2010-01-01

    Reticulate tissue systems exist in most multicellular organisms, and the principles underlying the formation of cellular networks have fascinated philosophers, mathematicians, and biologists for centuries. In particular, the beautiful and varied arrangements of vascular tissues in plants have intrigued mankind since antiquity, yet the organizing signals have remained elusive. Plant vascular tissues form systems of interconnected cell files throughout the plant body. Vascular cells are aligned with one another along continuous lines, and vascular tissues differentiate at reproducible positions within organ environments. However, neither the precise path of vascular differentiation nor the exact geometry of vascular networks is fixed or immutable. Several recent advances converge to reconcile the seemingly conflicting predictability and plasticity of vascular tissue patterns. A control mechanism in which an apical-basal flow of signal establishes a basic coordinate system for body axis formation and vascular strand differentiation, and in which a superimposed level of radial organizing cues elaborates cell patterns, would generate a reproducible tissue configuration in the context of an underlying robust, self-organizing structure, and account for the simultaneous regularity and flexibility of vascular tissue patterns.

  16. Natural patterns of energy dispersal.

    PubMed

    Mäkelä, Teemu; Annila, Arto

    2010-12-01

    Universal patterns such as power-law dependences, skewed distributions, tree-like structures, networks and spirals are associated with energy dispersal processes using the principle of least action. Also ubiquitous temporal courses such as sigmoid growth, bifurcations and chaos are ascribed to the decrease of free energy in the least time. Moreover, emergence of natural standards such as the common genetic code and chirality consensus of amino acids are understood to follow from the quest to maximize the dispersal of energy. Many mathematical functions that model natural patterns and processes are found as approximations of the evolutionary equation of motion that has been derived from statistical physics of open systems. The evolutionary processes can be described as flows of energy that run from high energy sources to low energy sinks in the least time. However, the equation of evolution cannot be solved in general because the flows of energy and their driving forces are inseparable. Since the energy of the system keeps changing, the paths of evolution cannot be integrated from a given initial state to a final state. Although evolutionary courses of these non-Hamiltonian systems with two or more alternative ways of dissipation cannot be predicted, the flows of energy will search and naturally select paths of least action, known as geodesics, to consume free energy in the least time. The scale-invariant natural patterns follow from this natural law that impinges on processes at all scales of space and time.

  17. Female pattern alopecia: current perspectives.

    PubMed

    Levy, Lauren L; Emer, Jason J

    2013-01-01

    Hair loss is a commonly encountered problem in clinical practice, with men presenting with a distinctive pattern involving hairline recession and vertex balding (Norwood-Hamilton classification) and women exhibiting diffuse hair thinning over the crown (increased part width) and sparing of the frontal hairline (Ludwig classification). Female pattern hair loss has a strikingly overwhelming psychological effect; thus, successful treatments are necessary. Difficulty lies in successful treatment interventions, as only two medications - minoxidil and finasteride - are approved for the treatment of androgenetic alopecia, and these medications offer mediocre results, lack of a permanent cure, and potential complications. Hair transplantation is the only current successful permanent option, and it requires surgical procedures. Several other medical options, such as antiandrogens (eg, spironolactone, oral contraceptives, cyproterone, flutamide, dutasteride), prostaglandin analogs (eg, bimatoprost, latanoprost), and ketoconazole are reported to be beneficial. Laser and light therapies have also become popular despite the lack of a profound benefit. Management of expectations is crucial, and the aim of therapy, given the current therapeutic options, is to slow or stop disease progression with contentment despite patient expectations of permanent hair regrowth. This article reviews current perspectives on therapeutic options for female pattern hair loss. PMID:24039457

  18. Female pattern alopecia: current perspectives

    PubMed Central

    Levy, Lauren L; Emer, Jason J

    2013-01-01

    Hair loss is a commonly encountered problem in clinical practice, with men presenting with a distinctive pattern involving hairline recession and vertex balding (Norwood-Hamilton classification) and women exhibiting diffuse hair thinning over the crown (increased part width) and sparing of the frontal hairline (Ludwig classification). Female pattern hair loss has a strikingly overwhelming psychological effect; thus, successful treatments are necessary. Difficulty lies in successful treatment interventions, as only two medications – minoxidil and finasteride – are approved for the treatment of androgenetic alopecia, and these medications offer mediocre results, lack of a permanent cure, and potential complications. Hair transplantation is the only current successful permanent option, and it requires surgical procedures. Several other medical options, such as antiandrogens (eg, spironolactone, oral contraceptives, cyproterone, flutamide, dutasteride), prostaglandin analogs (eg, bimatoprost, latanoprost), and ketoconazole are reported to be beneficial. Laser and light therapies have also become popular despite the lack of a profound benefit. Management of expectations is crucial, and the aim of therapy, given the current therapeutic options, is to slow or stop disease progression with contentment despite patient expectations of permanent hair regrowth. This article reviews current perspectives on therapeutic options for female pattern hair loss. PMID:24039457

  19. Visualizing Dynamic Bitcoin Transaction Patterns.

    PubMed

    McGinn, Dan; Birch, David; Akroyd, David; Molina-Solana, Miguel; Guo, Yike; Knottenbelt, William J

    2016-06-01

    This work presents a systemic top-down visualization of Bitcoin transaction activity to explore dynamically generated patterns of algorithmic behavior. Bitcoin dominates the cryptocurrency markets and presents researchers with a rich source of real-time transactional data. The pseudonymous yet public nature of the data presents opportunities for the discovery of human and algorithmic behavioral patterns of interest to many parties such as financial regulators, protocol designers, and security analysts. However, retaining visual fidelity to the underlying data to retain a fuller understanding of activity within the network remains challenging, particularly in real time. We expose an effective force-directed graph visualization employed in our large-scale data observation facility to accelerate this data exploration and derive useful insight among domain experts and the general public alike. The high-fidelity visualizations demonstrated in this article allowed for collaborative discovery of unexpected high frequency transaction patterns, including automated laundering operations, and the evolution of multiple distinct algorithmic denial of service attacks on the Bitcoin network.

  20. Visualizing Dynamic Bitcoin Transaction Patterns

    PubMed Central

    McGinn, Dan; Birch, David; Akroyd, David; Molina-Solana, Miguel; Guo, Yike; Knottenbelt, William J.

    2016-01-01

    Abstract This work presents a systemic top-down visualization of Bitcoin transaction activity to explore dynamically generated patterns of algorithmic behavior. Bitcoin dominates the cryptocurrency markets and presents researchers with a rich source of real-time transactional data. The pseudonymous yet public nature of the data presents opportunities for the discovery of human and algorithmic behavioral patterns of interest to many parties such as financial regulators, protocol designers, and security analysts. However, retaining visual fidelity to the underlying data to retain a fuller understanding of activity within the network remains challenging, particularly in real time. We expose an effective force-directed graph visualization employed in our large-scale data observation facility to accelerate this data exploration and derive useful insight among domain experts and the general public alike. The high-fidelity visualizations demonstrated in this article allowed for collaborative discovery of unexpected high frequency transaction patterns, including automated laundering operations, and the evolution of multiple distinct algorithmic denial of service attacks on the Bitcoin network. PMID:27441715

  1. Intrinsic Patterns of Human Activity

    NASA Astrophysics Data System (ADS)

    Hu, Kun; Ivanov, Plamen Ch.; Chen, Zhi; Hilton, Michael; Stanley, H. Eugene; Shea, Steven

    2003-03-01

    Activity is one of the defining features of life. Control of human activity is complex, being influenced by many factors both extrinsic and intrinsic to the body. The most obvious extrinsic factors that affect activity are the daily schedule of planned events, such as work and recreation, as well as reactions to unforeseen or random events. These extrinsic factors may account for the apparently random fluctuations in human motion observed over short time scales. The most obvious intrinsic factors are the body clocks including the circadian pacemaker that influences our sleep/wake cycle and ultradian oscillators with shorter time scales [2, 3]. These intrinsic rhythms may account for the underlying regularity in average activity level over longer periods of up to 24 h. Here we ask if the known extrinsic and intrinsic factors fully account for all complex features observed in recordings of human activity. To this end, we measure activity over two weeks from forearm motion in subjects undergoing their regular daily routine. Utilizing concepts from statistical physics, we demonstrate that during wakefulness human activity possesses previously unrecognized complex dynamic patterns. These patterns of activity are characterized by robust fractal and nonlinear dynamics including a universal probability distribution and long-range power-law correlations that are stable over a wide range of time scales (from minutes to hours). Surprisingly, we find that these dynamic patterns are unaffected by changes in the average activity level that occur within individual subjects throughout the day and on different days of the week, and between subjects. Moreover, we find that these patterns persist when the same subjects undergo time-isolation laboratory experiments designed to account for the phase of the circadian pacemaker, and control the known extrinsic factors by restricting behaviors and manipulating scheduled events including the sleep/wake cycle. We attribute these newly

  2. Inspection of imprint lithography patterns for semiconductor and patterned media

    NASA Astrophysics Data System (ADS)

    Resnick, Douglas J.; Haase, Gaddi; Singh, Lovejeet; Curran, David; Schmid, Gerard M.; Luo, Kang; Brooks, Cindy; Selinidis, Kosta; Fretwell, John; Sreenivasan, S. V.

    2010-03-01

    Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the requirements of cost-effective device production. This work summarizes the results of defect inspections of semiconductor masks, wafers and hard disks patterned using Jet and Flash Imprint Lithography (J-FILTM). Inspections were performed with optical and e-beam based automated inspection tools. For the semiconductor market, a test mask was designed which included dense features (with half pitches ranging between 32 nm and 48 nm) containing an extensive array of programmed defects. For this work, both e-beam inspection and optical inspection were used to detect both random defects and the programmed defects. Analytical SEMs were then used to review the defects detected by the inspection. Defect trends over the course of many wafers were observed with another test mask using a KLA-T 2132 optical inspection tool. The primary source of defects over 2000 imprints were particle related. For the hard drive market, it is important to understand the defectivity of both the template and the imprinted disk. This work presents a methodology for automated pattern inspection and defect classification for imprint-patterned media. Candela CS20 and 6120 tools from KLA-Tencor map the optical properties of the disk surface, producing highresolution grayscale images of surface reflectivity, scattered light, phase shift, etc. Defects that have been identified in this manner are further characterized according to the morphology

  3. Frequent patterns mining in multiple biological sequences.

    PubMed

    Chen, Ling; Liu, Wei

    2013-10-01

    Existing algorithms for mining frequent patterns in multiple biosequences may generate multiple projected databases and short candidate patterns, which can increase computation time and memory requirement. In order to overcome such shortcomings, we propose a fast and efficient algorithm for mining frequent patterns in multiple biological sequences (MSPM). We first present the concept of a primary pattern, which can be extended to form larger patterns in the sequence. To detect frequent primary patterns, a prefix tree is constructed. Based on this prefix tree, a pattern-extending approach is also presented to mine frequent patterns without producing a large number of irrelevant candidate patterns. The experimental results show that the MSPM algorithm can achieve not only faster speed, but also higher quality results as compared with other methods. PMID:24034736

  4. Clinical application of simultaneous pattern VEP and pattern ERG recording.

    PubMed

    Song, H S; Ku, W C; Yeh, S F

    1995-06-01

    Thirteen eyes of optic neuropathy and 13 eyes of maculopathy during Sep. 1990-May 1992 were studied by simultaneous pattern VEP (PVEP) and pattern ERG (PERG) recording. In optic neuropathy, the P100 of PVEP was delayed in 7 eyes (ave. 108.87 msec; normal 94.41 +/- 3.51 msec), absent in 5 eyes, normal in 1 eye. Their PERG showed normal P50 amplitude (either normal or delayed latency) but small or absent N95 in 8 eyes. In maculopathy, the P100 of PVEP was delayed in 2 eyes (ave. 103.59msec), absent in 7 eyes, normal in 4 eyes. However, their PERG showed 12 eyes had small or absent P50. Combined PVEP & PERG test, when compared to PVEP alone, increased the diagnostic value from 57.1% to 100% for optic neuropathy and from 42.9% to 80% for maculopathy in this study. Thus, simultaneous PVEP & PERG recording is highly recommended in evaluation of anterior visual pathway disorders. PMID:7641105

  5. Pattern Search Algorithms for Bound Constrained Minimization

    NASA Technical Reports Server (NTRS)

    Lewis, Robert Michael; Torczon, Virginia

    1996-01-01

    We present a convergence theory for pattern search methods for solving bound constrained nonlinear programs. The analysis relies on the abstract structure of pattern search methods and an understanding of how the pattern interacts with the bound constraints. This analysis makes it possible to develop pattern search methods for bound constrained problems while only slightly restricting the flexibility present in pattern search methods for unconstrained problems. We prove global convergence despite the fact that pattern search methods do not have explicit information concerning the gradient and its projection onto the feasible region and consequently are unable to enforce explicitly a notion of sufficient feasible decrease.

  6. Invarient patterns in articulatory movements

    NASA Astrophysics Data System (ADS)

    Bonaventura, Patrizia

    2004-04-01

    The purpose of the reported study is to discover an effective method of characterizing movement patterns of the crucial articulator as the function of an abstract syllable magnitude and the adjacent boundary, and at the same time to investigate effects of prosodic control on utterance organization. In particular, the speed of movement when a flesh point on the tongue blade or the lower lip crosses a selected position relative to the occlusion plane is examined. The time of such crossing provides an effective measure of syllable timing and syllable duration according to previous work. In the present work, using a very limited vocabulary with only a few consonants and one vowel as the key speech materials, effects of contrastive emphasis on demisyllabic movement patterns were studied. The theoretical framework for this analysis is the C/D model of speech production in relation to the concept of an invariant part of selected articulatory movements. The results show evidence in favor of the existence of ``iceberg'' patterns, but a linear dependence of slope on the total excursion of the demisyllabic movement, instead of the approximate constancy of the threshold crossing speed as suggested in the original proposal of the iceberg, has been found. Accordingly, a revision of the original concept of iceberg, seems necessary. This refinement is consistent with the C/D model assumption on ``prominence control'' that the syllable magnitude determines the movement amplitude, accompanying directly related syllable duration change. In this assumption, the movement of a consonantal component should also be proportional to syllable magnitude. The results suggests, however, systematic outliers deviating from the linear dependence of movement speed on excursion. This deviation may be caused by the effect of the immediately following boundary, often referred to as phrase-final elongation. Thesis advisor: Osamu Fujimura Copies of this thesis written in English can be obtained from

  7. Separation vortices and pattern formation

    NASA Astrophysics Data System (ADS)

    Andersen, Anders; Bohr, Tomas; Schnipper, Teis

    2010-03-01

    In this paper examples are given of the importance of flow separation for fluid patterns at moderate Reynolds numbers—both in the stationary and in the time-dependent domain. In the case of circular hydraulic jumps, it has been shown recently that it is possible to generalise the Prandtl-Kármán-Pohlhausen approach to stationary boundary layers with free surfaces going through separation, and thus obtain a quantitative theory of the simplest type of hydraulic jump, where a single separation vortex is present outside the jump. A second type of jump, where an additional roller appears at the surface, cannot be captured by this approach and has not been given an adequate theoretical description. Such a model is needed to describe “polygonal” hydraulic jumps, which occur by spontaneous symmetry breaking of the latter state. Time-dependent separation is of importance in the formation of sand ripples under oscillatory flow, where the separation vortices become very strong. In this case no simple theory exists for the determination of the location and strengths of separation vortices over a wavy bottom of arbitrary profile. We have, however, recently suggested an amplitude equation describing the long-time evolution of the sand ripple pattern, which has the surprising features that it breaks the local sand conservation and has long-range interaction, features that can be underpinned by experiments. Very similar vortex dynamics takes place around oscillating structures such as wings and fins. Here, we present results for the vortex patterns behind a flapping foil in a flowing soap film, which shows the interaction and competition between the vortices shed from the round leading edge (like the von Kármán vortex street) and those created at the sharp trailing edge.

  8. Recent data on zebra patterns

    NASA Astrophysics Data System (ADS)

    Chernov, G. P.; Yan, Y. H.; Fu, Q. J.; Tan, Ch. M.

    2005-07-01

    A comparative analysis of two recent solar radio outbursts around 3 GHz with zebra structures and fiber bursts in their dynamical radio spectra is carried out using all available ground-based and satellite data (SOHO, TRACE, RHESSI). The latest theoretical models of the zebra pattern are critically discussed. New data on microwave zebra structures and fiber bursts suggests that they are analogous to similar structures observed at meter wavelengths. It was discovered that in the 2,6-3,8 GHz frequency band more than 34 zebra stripes can appear simultaneously, and some isolated fiber bursts can continuously be transformed into zebra stripes. This fact indicates a single origin for both structures. The zebra pattern was observed when the signs of magnetic reconnections were revealed in images of 195 Å UV lines, and radio sources coincided with positions of some new sources in hard X-rays. All the main properties of the stripes in emission and absorption can be explained if they are associated with interactions between electrostatic plasma waves and whistlers, taking into account the quasi-linear diffusion of fast particles with the loss-cone distribution on whistlers. In this model it is possible to obtain realistic values for the magnetic field strength of B ≈ 160~G at the plasma level of about 3 GHz. The double plasma resonance model for the zebra pattern based on the known realistic dependences of electron density and magnetic field yields a frequency dependence for the frequency separation between stripes that does not agree with the observations.

  9. Patterns of fish sound production

    NASA Astrophysics Data System (ADS)

    Mann, David A.

    2003-04-01

    While vocalization and chorusing behavior has been intensively studied in frogs and birds, little has been done with fishes. This paper presents patterns of sound production in damselfish, toadfish, and spotted seatrout on seasonal, daily, and subdaily time scales. Chorus behavior ranges from highly coordinated behavior between neighboring toadfish to uncoordinated behavior in spotted seatrout. Differences in coordination of sound production (i.e., the degree of overlap in calls) can be related to differences in territoriality and modes of reproduction. Toadfish and damselfish are territorial fishes in which males guard benthic eggs laid in nests. Sciaenids (croakers and drums) spawn planktonic eggs, and form temporary aggregations of calling males.

  10. Spray patternation at high pressure

    NASA Astrophysics Data System (ADS)

    Cohen, J. M.; Rosfjord, T. J.

    1989-07-01

    The spatial distribution of the fuel spray created by a gas turbine fuel injector has been measured at high pressure and temperature. A patternation system for measuring fuel spray mass flux distributions at high power conditions has been designed and operated. The facility has been designed to simulate the environment inside a gas turbine combustor as closely as possible. Results for a full scale gas turbine fuel injector have been obtained at high levels of pressure, temperature and liquid flowrate and compared with visual observations.

  11. Pattern recognition techniques in Polarimetry

    NASA Astrophysics Data System (ADS)

    Ariste, Arturo López

    2015-10-01

    Sparsity is a property of data by which it can be represented using a small number of patterns. It is the key concept behind an evergrowing list of mathematical techniques for handling data and recover from it signals or information in conditions previously thought impossible. The application of those techniques to spectropolarimetric data is relatively straightforward. We present three examples of such application: the use of Principal Component Analysis to invert the magnetic field in solar prominences from spectropolarimetry of the He D3 line, the removal of fringes from spectropolarimetric data with Relevance Vector Machines, and the retrieval of high resolution spectra from low resolution data with Compressed Sensing.

  12. Zonal flow as pattern formation

    NASA Astrophysics Data System (ADS)

    Parker, Jeffrey B.; Krommes, John A.

    2013-10-01

    Zonal flows are well known to arise spontaneously out of turbulence. We show that for statistically averaged equations of the stochastically forced generalized Hasegawa-Mima model, steady-state zonal flows, and inhomogeneous turbulence fit into the framework of pattern formation. There are many implications. First, the wavelength of the zonal flows is not unique. Indeed, in an idealized, infinite system, any wavelength within a certain continuous band corresponds to a solution. Second, of these wavelengths, only those within a smaller subband are linearly stable. Unstable wavelengths must evolve to reach a stable wavelength; this process manifests as merging jets.

  13. Zonal flow as pattern formation

    SciTech Connect

    Parker, Jeffrey B.; Krommes, John A.

    2013-10-15

    Zonal flows are well known to arise spontaneously out of turbulence. We show that for statistically averaged equations of the stochastically forced generalized Hasegawa-Mima model, steady-state zonal flows, and inhomogeneous turbulence fit into the framework of pattern formation. There are many implications. First, the wavelength of the zonal flows is not unique. Indeed, in an idealized, infinite system, any wavelength within a certain continuous band corresponds to a solution. Second, of these wavelengths, only those within a smaller subband are linearly stable. Unstable wavelengths must evolve to reach a stable wavelength; this process manifests as merging jets.

  14. Apparatus for generating nonlinear pulse patterns

    DOEpatents

    Nakamura, Michiyuki

    1981-01-01

    Apparatus for generating a plurality of nonlinear pulse patterns from a single linear pulse pattern. A first counter counts the pulses of the linear pulse pattern and a second counter counts the pulses of the nonlinear pulse pattern. A comparator compares the counts of both counters, and in response to an equal count, a gate is enabled to gate a pulse of the linear pattern as a pulse of the nonlinear pattern, the latter also resetting the first counter. Presettable dividers divide the pulses of each pattern before they are counted by the respective counters. Also, apparatus for generating a logarithmic pulse pattern from a linear pulse pattern to any log base. In one embodiment, a shift register is used in place of the second counter to be clocked by each pulse of the logarithmic pattern to generate the pattern. In another embodiment, a memory stores the logarithmic pattern and is addressed by the second counter which is clocked by the pulses of the logarithmic pulse pattern.

  15. Apparatus for generating nonlinear pulse patterns

    DOEpatents

    Nakamura, N.M.I.

    Apparatus for generating a plurality of nonlinear pulse patterns from a single linear pulse pattern. A first counter counts the pulses of the linear pulse pattern and a second counter counts the pulses of the nonlinear pulse pattern. A comparator compares the counts of both counters, and in response to an equal count, a gate is enabled to gate a pulse of the linear pattern as a pulse of the nonlinear pattern, the latter also resetting the first counter. Presettable dividers divide the pulses of each pattern before they are counted by the respective counters. Apparatus for generating a logarithmic pulse pattern from a linear pulse pattern to any log base is described. In one embodiment, a shift register is used in place of the second counter to be clocked by each pulse of the logarithmic pattern to generate the pattern. In another embodiment, a memory stores the logarithmic pattern and is addressed by the second counter which is clocked by the pulses of the logarithmic pulse pattern.

  16. A positive patterning advantage with complex but not simple patterning: a cue constellation approach.

    PubMed

    Whitlow, J W

    2013-01-01

    Determinants of a positive patterning advantage (that is, an advantage for positive patterning over negative patterning) in human causal reasoning were examined in an experiment that compared simple patterning discriminations (A, B vs. AB) to complex patterning discriminations (AB, BC, AC vs. ABC). As predicted by a cue constellation analysis of complex discriminations, a positive patterning advantage was found with complex patterning but not with simple patterning discriminations. This result may explain why some recent studies have found a positive patterning advantage where earlier studies had failed to find one. The interaction of patterning complexity with the positive patterning advantage appears to pose problems for rule-based accounts of patterning. The results support the view that associative theories of human causal reasoning are more easily distinguished from rule-based approaches when applied to conditions that make simple rules difficult to identify or implement.

  17. Prolegomenon to patterns in evolution.

    PubMed

    Kauffman, Stuart A

    2014-09-01

    Despite Darwin, we remain children of Newton and dream of a grand theory that is epistemologically complete and would allow prediction of the evolution of the biosphere. The main purpose of this article is to show that this dream is false, and bears on studying patterns of evolution. To do so, I must justify the use of the word "function" in biology, when physics has only happenings. The concept of "function" lifts biology irreducibly above physics, for as we shall see, we cannot prestate the ever new biological functions that arise and constitute the very phase space of evolution. Hence, we cannot mathematize the detailed becoming of the biosphere, nor write differential equations for functional variables we do not know ahead of time, nor integrate those equations, so no laws "entail" evolution. The dream of a grand theory fails. In place of entailing laws, I propose a post-entailing law explanatory framework in which Actuals arise in evolution that constitute new boundary conditions that are enabling constraints that create new, typically unprestatable, adjacent possible opportunities for further evolution, in which new Actuals arise, in a persistent becoming. Evolution flows into a typically unprestatable succession of adjacent possibles. Given the concept of function, the concept of functional closure of an organism making a living in its world becomes central. Implications for patterns in evolution include historical reconstruction, and statistical laws such as the distribution of extinction events, or species per genus, and the use of formal cause, not efficient cause, laws. PMID:24704211

  18. Dynamics of evaporative colloidal patterning

    NASA Astrophysics Data System (ADS)

    Kaplan, C. Nadir; Wu, Ning; Mandre, Shreyas; Aizenberg, Joanna; Mahadevan, L.

    2015-09-01

    Drying suspensions often leave behind complex patterns of particulates, as might be seen in the coffee stains on a table. Here, we consider the dynamics of periodic band or uniform solid film formation on a vertical plate suspended partially in a drying colloidal solution. Direct observations allow us to visualize the dynamics of band and film deposition, where both are made of multiple layers of close packed particles. We further see that there is a transition between banding and filming when the colloidal concentration is varied. A minimal theory of the liquid meniscus motion along the plate reveals the dynamics of the banding and its transition to the filming as a function of the ratio of deposition and evaporation rates. We also provide a complementary multiphase model of colloids dissolved in the liquid, which couples the inhomogeneous evaporation at the evolving meniscus to the fluid and particulate flows and the transition from a dilute suspension to a porous plug. This allows us to determine the concentration dependence of the bandwidth and the deposition rate. Together, our findings allow for the control of drying-induced patterning as a function of the colloidal concentration and evaporation rate.

  19. Pattern Formation and Complexity Emergence

    NASA Astrophysics Data System (ADS)

    Berezin, Alexander A.

    2001-03-01

    Success of nonlinear modelling of pattern formation and self-organization encourages speculations on informational and number theoretical foundations of complexity emergence. Pythagorean "unreasonable effectiveness of integers" in natural processes is perhaps extrapolatable even to universal emergence "out-of-nothing" (Leibniz, Wheeler). Because rational numbers (R = M/N) are everywhere dense on real axis, any digital string (hence any "book" from "Library of Babel" of J.L.Borges) is "recorded" infinitely many times in arbitrary many rationals. Furthermore, within any arbitrary small interval there are infinitely many Rs for which (either or both) integers (Ms and Ns) "carry" any given string of any given length. Because any iterational process (such as generation of fractal features of Mandelbrot Set) is arbitrary closely approximatable with rational numbers, the infinite pattern of integers expresses itself in generation of complexity of the world, as well as in emergence of the world itself. This "tunnelling" from Platonic World ("Platonia" of J.Barbour) to a real (physical) world is modern recast of Leibniz's motto ("for deriving all from nothing there suffices a single principle").

  20. Locomotor patterns in cerebellar ataxia.

    PubMed

    Martino, G; Ivanenko, Y P; Serrao, M; Ranavolo, A; d'Avella, A; Draicchio, F; Conte, C; Casali, C; Lacquaniti, F

    2014-12-01

    Several studies have demonstrated how cerebellar ataxia (CA) affects gait, resulting in deficits in multijoint coordination and stability. Nevertheless, how lesions of cerebellum influence the locomotor muscle pattern generation is still unclear. To better understand the effects of CA on locomotor output, here we investigated the idiosyncratic features of the spatiotemporal structure of leg muscle activity and impairments in the biomechanics of CA gait. To this end, we recorded the electromyographic (EMG) activity of 12 unilateral lower limb muscles and analyzed kinematic and kinetic parameters of 19 ataxic patients and 20 age-matched healthy subjects during overground walking. Neuromuscular control of gait in CA was characterized by a considerable widening of EMG bursts and significant temporal shifts in the center of activity due to overall enhanced muscle activation between late swing and mid-stance. Patients also demonstrated significant changes in the intersegmental coordination, an abnormal transient in the vertical ground reaction force and instability of limb loading at heel strike. The observed abnormalities in EMG patterns and foot loading correlated with the severity of pathology [International Cooperative Ataxia Rating Scale (ICARS), a clinical ataxia scale] and the changes in the biomechanical output. The findings provide new insights into the physiological role of cerebellum in optimizing the duration of muscle activity bursts and the control of appropriate foot loading during locomotion.

  1. A typology of street patterns

    PubMed Central

    Louf, Rémi; Barthelemy, Marc

    2014-01-01

    We propose a quantitative method to classify cities according to their street pattern. We use the conditional probability distribution of shape factor of blocks with a given area and define what could constitute the ‘fingerprint’ of a city. Using a simple hierarchical clustering method, these fingerprints can then serve as a basis for a typology of cities. We apply this method to a set of 131 cities in the world, and at an intermediate level of the dendrogram, we observe four large families of cities characterized by different abundances of blocks of a certain area and shape. At a lower level of the classification, we find that most European cities and American cities in our sample fall in their own sub-category, highlighting quantitatively the differences between the typical layouts of cities in both regions. We also show with the example of New York and its different boroughs, that the fingerprint of a city can be seen as the sum of the ones characterizing the different neighbourhoods inside a city. This method provides a quantitative comparison of urban street patterns, which could be helpful for a better understanding of the causes and mechanisms behind their distinct shapes. PMID:25297318

  2. Prolegomenon to patterns in evolution.

    PubMed

    Kauffman, Stuart A

    2014-09-01

    Despite Darwin, we remain children of Newton and dream of a grand theory that is epistemologically complete and would allow prediction of the evolution of the biosphere. The main purpose of this article is to show that this dream is false, and bears on studying patterns of evolution. To do so, I must justify the use of the word "function" in biology, when physics has only happenings. The concept of "function" lifts biology irreducibly above physics, for as we shall see, we cannot prestate the ever new biological functions that arise and constitute the very phase space of evolution. Hence, we cannot mathematize the detailed becoming of the biosphere, nor write differential equations for functional variables we do not know ahead of time, nor integrate those equations, so no laws "entail" evolution. The dream of a grand theory fails. In place of entailing laws, I propose a post-entailing law explanatory framework in which Actuals arise in evolution that constitute new boundary conditions that are enabling constraints that create new, typically unprestatable, adjacent possible opportunities for further evolution, in which new Actuals arise, in a persistent becoming. Evolution flows into a typically unprestatable succession of adjacent possibles. Given the concept of function, the concept of functional closure of an organism making a living in its world becomes central. Implications for patterns in evolution include historical reconstruction, and statistical laws such as the distribution of extinction events, or species per genus, and the use of formal cause, not efficient cause, laws.

  3. How to pattern a leaf.

    PubMed

    Bolduc, N; O'Connor, D; Moon, J; Lewis, M; Hake, S

    2012-01-01

    Leaf development presents a tremendous resource for tackling the question of patterning in biology. Leaves can be simple or highly dissected. They may have elaborated parts such as the tendrils of a pea leaf or the rolled blade of a carnivorous pitcher plant. Despite the variation in size, shape, and function, all leaves initiate in the same manner: from the flanks of a meristem. The maize leaf is useful for analysis of patterning due to the wealth of mutants and the distinct tissues along the proximal distal axis. The blade is distal, the sheath is proximal, and the ligule forms at the blade/sheath boundary. Establishment of this boundary involves the transcription factors LIGULELESS1 and LIGULELESS2 and the kinase LIGULELESS NARROW. The meristem-specific protein KNOTTED1 (KN1) binds and modulates the lg2 gene. Given the localization of KN1 at the proximal end of the leaf from the time of inception, we hypothesize that KN1 has a role in establishing the very proximal end of the leaf, whereas an auxin maximum guides the growing distal tip. PMID:23174765

  4. A typology of street patterns.

    PubMed

    Louf, Rémi; Barthelemy, Marc

    2014-12-01

    We propose a quantitative method to classify cities according to their street pattern. We use the conditional probability distribution of shape factor of blocks with a given area and define what could constitute the 'fingerprint' of a city. Using a simple hierarchical clustering method, these fingerprints can then serve as a basis for a typology of cities. We apply this method to a set of 131 cities in the world, and at an intermediate level of the dendrogram, we observe four large families of cities characterized by different abundances of blocks of a certain area and shape. At a lower level of the classification, we find that most European cities and American cities in our sample fall in their own sub-category, highlighting quantitatively the differences between the typical layouts of cities in both regions. We also show with the example of New York and its different boroughs, that the fingerprint of a city can be seen as the sum of the ones characterizing the different neighbourhoods inside a city. This method provides a quantitative comparison of urban street patterns, which could be helpful for a better understanding of the causes and mechanisms behind their distinct shapes. PMID:25297318

  5. Crowding by a repeating pattern.

    PubMed

    Rosen, Sarah; Pelli, Denis G

    2015-01-01

    Theinability to recognize a peripheral target among flankers is called crowding. For a foveal target, crowding can be distinguished from overlap masking by its sparing of detection, linear scaling with eccentricity, and invariance with target size.Crowding depends on the proximity and similarity of the flankers to the target. Flankers that are far from or dissimilar to the target do not crowd it. On a gray page, text whose neighboring letters have different colors, alternately black and white, has enough dissimilarity that it might escape crowding. Since reading speed is normally limited by crowding, escape from crowding should allow faster reading. Yet reading speed is unchanged (Chung & Mansfield, 2009). Why? A recent vernier study found that using alternating-color flankers produces strong crowding (Manassi, Sayim, & Herzog, 2012). Might that effect occur with letters and reading? Critical spacing is the minimum center-to-center target-flanker spacing needed to correctly identify the target. We measure it for a target letter surrounded by several equidistant flanker letters of the same polarity, opposite polarity, or mixed polarity: alternately white and black. We find strong crowding in the alternating condition, even though each flanker letter is beyond its own critical spacing (as measured in a separate condition). Thus a periodic repeating pattern can produce crowding even when the individual elements do not. Further, in all conditions we find that, once a periodic pattern repeats (two cycles), further repetition does not affect critical spacing of the innermost flanker.

  6. Smart skin patterns protect springtails.

    PubMed

    Helbig, Ralf; Nickerl, Julia; Neinhuis, Christoph; Werner, Carsten

    2011-01-01

    Springtails, arthropods who live in soil, in decaying material, and on plants, have adapted to demanding conditions by evolving extremely effective and robust anti-adhesive skin patterns. However, details of these unique properties and their structural basis are still unknown. Here we demonstrate that collembolan skin can resist wetting by many organic liquids and at elevated pressures. We show that the combination of bristles and a comb-like hexagonal or rhombic mesh of interconnected nanoscopic granules distinguish the skin of springtails from anti-adhesive plant surfaces. Furthermore, the negative overhang in the profile of the ridges and granules were revealed to be a highly effective, but as yet neglected, design principle of collembolan skin. We suggest an explanation for the non-wetting characteristics of surfaces consisting of such profiles irrespective of the chemical composition. Many valuable opportunities arise from the translation of the described comb-like patterns and overhanging profiles of collembolan skin into man-made surfaces that combine stability against wear and friction with superior non-wetting and anti-adhesive characteristics. PMID:21980383

  7. Pattern formation in centrosome assembly.

    PubMed

    Mahen, Robert; Venkitaraman, Ashok R

    2012-02-01

    A striking but poorly explained feature of cell division is the ability to assemble and maintain organelles not bounded by membranes, from freely diffusing components in the cytosol. This process is driven by information transfer across biological scales such that interactions at the molecular scale allow pattern formation at the scale of the organelle. One important example of such an organelle is the centrosome, which is the main microtubule organising centre in the cell. Centrosomes consist of two centrioles surrounded by a cloud of proteins termed the pericentriolar material (PCM). Profound structural and proteomic transitions occur in the centrosome during specific cell cycle stages, underlying events such as centrosome maturation during mitosis, in which the PCM increases in size and microtubule nucleating capacity. Here we use recent insights into the spatio-temporal behaviour of key regulators of centrosomal maturation, including Polo-like kinase 1, CDK5RAP2 and Aurora-A, to propose a model for the assembly and maintenance of the PCM through the mobility and local interactions of its constituent proteins. We argue that PCM structure emerges as a pattern from decentralised self-organisation through a reaction-diffusion mechanism, with or without an underlying template, rather than being assembled from a central structural template alone. Self-organisation of this kind may have broad implications for the maintenance of mitotic structures, which, like the centrosome, exist stably as supramolecular assemblies on the micron scale, based on molecular interactions at the nanometer scale. PMID:22245706

  8. Urban biodiversity: patterns and mechanisms.

    PubMed

    Faeth, Stanley H; Bang, Christofer; Saari, Susanna

    2011-03-01

    The patterns of biodiversity changes in cities are now fairly well established, although diversity changes in temperate cities are much better studied than cities in other climate zones. Generally, plant species richness often increases in cities due to importation of exotic species, whereas animal species richness declines. Abundances of some groups, especially birds and arthropods, often increase in urban areas despite declines in species richness. Although several models have been proposed for biodiversity change, the processes underlying the patterns of biodiversity in cities are poorly understood. We argue that humans directly control plants but relatively few animals and microbes-the remaining biological community is determined by this plant "template" upon which natural ecological and evolutionary processes act. As a result, conserving or reconstructing natural habitats defined by vegetation within urban areas is no guarantee that other components of the biological community will follow suit. Understanding the human-controlled and natural processes that alter biodiversity is essential for conserving urban biodiversity. This urban biodiversity will comprise a growing fraction of the world's repository of biodiversity in the future.

  9. Smart Skin Patterns Protect Springtails

    PubMed Central

    Helbig, Ralf; Nickerl, Julia; Neinhuis, Christoph; Werner, Carsten

    2011-01-01

    Springtails, arthropods who live in soil, in decaying material, and on plants, have adapted to demanding conditions by evolving extremely effective and robust anti-adhesive skin patterns. However, details of these unique properties and their structural basis are still unknown. Here we demonstrate that collembolan skin can resist wetting by many organic liquids and at elevated pressures. We show that the combination of bristles and a comb-like hexagonal or rhombic mesh of interconnected nanoscopic granules distinguish the skin of springtails from anti-adhesive plant surfaces. Furthermore, the negative overhang in the profile of the ridges and granules were revealed to be a highly effective, but as yet neglected, design principle of collembolan skin. We suggest an explanation for the non-wetting characteristics of surfaces consisting of such profiles irrespective of the chemical composition. Many valuable opportunities arise from the translation of the described comb-like patterns and overhanging profiles of collembolan skin into man-made surfaces that combine stability against wear and friction with superior non-wetting and anti-adhesive characteristics. PMID:21980383

  10. Optimizing Grid Patterns on Photovoltaic Cells

    NASA Technical Reports Server (NTRS)

    Burger, D. R.

    1984-01-01

    CELCAL computer program helps in optimizing grid patterns for different photovoltaic cell geometries and metalization processes. Five different powerloss phenomena associated with front-surface metal grid pattern on photovoltaic cells.

  11. Hierarchically UVO patterned elastomeric and thermoplastic structures

    NASA Astrophysics Data System (ADS)

    Chen, Ying; Kulkarni, Manish; Marshall, Allan; Karim, Alamgir

    2014-03-01

    We demonstrate a simple yet versatile method to fabricate tunable hierarchical micro-nanostructures on flexible Poly(dimethylsiloxane) (PDMS) elastomer and thermoplastic polymer surface by a two-step process. Nanoscale patterned PDMS was obtained by imprinting compact disc (CD)/digital video disc (DVD) patterns. The second micro pattern was superposed by selective densification of PDMS by exposing to ultraviolet-ozone radiation (UVO) through micro-patterned TEM grid as a mask. The nanoscale patterns are preserved through UVO exposure step leading to formation of deep hierarchical patterns, so that for a 19 um square mesh, the micro pattern has a depth of 600nm with 6h PDMS UVO exposure time. This simple method can be promoted to fabricate hierarchical structures of thermoplastic materials (such as polystyrene), from which the mechanism of capillary imprinting and thermal stability of hierarchical patterns are investigated. This study is potentially important to various applications ranging from biomimetic scaffolds to solar cell.

  12. A patterns catalog for RTSJ software designs

    NASA Technical Reports Server (NTRS)

    Benowitz, E. G.; Niessner, A. F.

    2003-01-01

    In this survey paper, we bring together current progress to date in identifying design patterns for use with the real-time specification for Java in a format consistent with contemporary patterns descriptions.

  13. Derivative Sign Patterns in Two Dimensions

    ERIC Educational Resources Information Center

    Schilling, Kenneth

    2013-01-01

    Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

  14. Sidewall forcing of hexagonal Turing patterns: rhombic patterns

    NASA Astrophysics Data System (ADS)

    Pérez-Muñuzuri, V.; Gómez-Gesteira, M.; Muñuzuri, A. P.; Chua, L. O.; Pérez-Villar, V.

    Rhombic arrays were obtained by sidewall forcing during Turing pattern formation in numerical simulations. Locking between the frequency of forcing and the wave length between blobs was obtained in accordance with the Farey sequence. This locking appears as a perfect rhombic array oriented in the direction of the imposed forcing. For a constant forcing in duration and amplitude, the following scheme of bifurcation was observed: parallel stripes ↦ rhombic array ↦ domains of hexagons and rhombi separated by “penta-hepta” defects. Symmetry considerations based on a non-uniform stretching along the x-axis were used to describe these transitions. Unstable “varicose-vein” stripes were observed to evolve during the temporal evolution arrays.

  15. Patterning microsphere surfaces by templating colloidal crystals.

    PubMed

    Zhang, Gang; Wang, Dayang; Möhwald, Helmuth

    2005-01-01

    By using the upper single or double layers in colloidal crystals as masks during Au vapor deposition, various Au patterns have been successfully constructed on the surfaces of the lower spheres. The dimension and geometry of the Au patterns obtained are dependent on the orientation of the colloidal crystal templates. Our patterning procedure is independent of the curvature and chemical composition of the surfaces, which definitely pave a promising way to pattern highly curved surfaces.

  16. Antenna with Dielectric Having Geometric Patterns

    NASA Technical Reports Server (NTRS)

    Dudley, Kenneth L. (Inventor); Elliott, Holly A. (Inventor); Cravey, Robin L. (Inventor); Connell, John W. (Inventor); Ghose, Sayata (Inventor); Watson, Kent A. (Inventor); Smith, Jr., Joseph G. (Inventor)

    2013-01-01

    An antenna includes a ground plane, a dielectric disposed on the ground plane, and an electrically-conductive radiator disposed on the dielectric. The dielectric includes at least one layer of a first dielectric material and a second dielectric material that collectively define a dielectric geometric pattern, which may comprise a fractal geometry. The radiator defines a radiator geometric pattern, and the dielectric geometric pattern is geometrically identical, or substantially geometrically identical, to the radiator geometric pattern.

  17. Oblique patterned etching of vertical silicon sidewalls

    DOE PAGES

    Burckel, D. Bruce; Finnegan, Patrick S.; Henry, M. David; Resnick, Paul J.; Jarecki, Jr., Robert L.

    2016-04-05

    A method for patterning on vertical silicon surfaces in high aspect ratio silicontopography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  18. Nonlinear pattern selection in explosive crystallization

    NASA Technical Reports Server (NTRS)

    Kurtze, Douglas A.

    1988-01-01

    It is shown analytically, in a suitable limit, that a sharp pattern-selection mechanism exists in driven explosive crystallization: after the onset of a morphological instability of the steady-state crystallization front, nonlinear effects cause the front to develop a spatial pattern with a definite wavelength. The amplitude, wavelength, and shape of the selected pattern are calculated analytically.

  19. Teaching Design Patterns through Computer Game Development

    ERIC Educational Resources Information Center

    Gestwicki, Paul; Sun, Fu-Shing

    2008-01-01

    We present an approach for teaching design patterns that emphasizes object-orientation and patterns integration. The context of computer game development is used to engage and motivate students, and it is additionally rich with design patterns. A case study is presented based on "EEClone," an arcade-style computer game implemented in Java. Our…

  20. Higher-Order Neural Networks Recognize Patterns

    NASA Technical Reports Server (NTRS)

    Reid, Max B.; Spirkovska, Lilly; Ochoa, Ellen

    1996-01-01

    Networks of higher order have enhanced capabilities to distinguish between different two-dimensional patterns and to recognize those patterns. Also enhanced capabilities to "learn" patterns to be recognized: "trained" with far fewer examples and, therefore, in less time than necessary to train comparable first-order neural networks.

  1. Oblique patterned etching of vertical silicon sidewalls

    NASA Astrophysics Data System (ADS)

    Bruce Burckel, D.; Finnegan, Patrick S.; David Henry, M.; Resnick, Paul J.; Jarecki, Robert L.

    2016-04-01

    A method for patterning on vertical silicon surfaces in high aspect ratio silicon topography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  2. Visual Templates in Pattern Generalization Activity

    ERIC Educational Resources Information Center

    Rivera, F. D.

    2010-01-01

    In this research article, I present evidence of the existence of visual templates in pattern generalization activity. Such templates initially emerged from a 3-week design-driven classroom teaching experiment on pattern generalization involving linear figural patterns and were assessed for existence in a clinical interview that was conducted four…

  3. Discursive Hierarchical Patterning in Economics Cases

    ERIC Educational Resources Information Center

    Lung, Jane

    2011-01-01

    This paper attempts to apply Lung's (2008) model of the discursive hierarchical patterning of cases to a closer and more specific study of Economics cases and proposes a model of the distinct discursive hierarchical patterning of the same. It examines a corpus of 150 Economics cases with a view to uncovering the patterns of discourse construction.…

  4. Detection and recognition of angular frequency patterns.

    PubMed

    Wilson, Hugh R; Propp, Roni

    2015-05-01

    Previous research has extensively explored visual encoding of smoothly curved, closed contours described by sinusoidal variation of pattern radius as a function of polar angle (RF patterns). Although the contours of many biologically significant objects are curved, we also confront shapes with a more jagged and angular appearance. To study these, we introduce here a novel class of visual stimuli that deform smoothly from a circle to an equilateral polygon with N sides (AF patterns). Threshold measurements reveal that both AF and RF patterns can be discriminated from circles at the same deformation amplitude, approximately 18.0arcsec, which is in the hyperacuity range. Thresholds were slightly higher for patterns with 3.0 cycles than for those with 5.0 cycles. Discrimination between AF and RF patterns was 75% correct at an amplitude that was approximately 3.0 times the threshold amplitude, which implies that AF and RF patterns activate different neural populations. Experiments with jittered patterns in which the contour was broken into several pieces and shifted inward or outward had much less effect on AF patterns than on RF patterns. Similarly, thresholds for single angles of AF patterns showed no significant difference from thresholds for the entire AF pattern. Taken together, these results imply that the visual system incorporates angles explicitly in the representation of closed object contours, but it suggests that angular contours are represented more locally than are curved contours.

  5. Orthogonal Patterns In A Binary Neural Network

    NASA Technical Reports Server (NTRS)

    Baram, Yoram

    1991-01-01

    Report presents some recent developments in theory of binary neural networks. Subject matter relevant to associate (content-addressable) memories and to recognition of patterns - both of considerable importance in advancement of robotics and artificial intelligence. When probed by any pattern, network converges to one of stored patterns.

  6. Psychological and Demographic Correlates of Career Patterns

    ERIC Educational Resources Information Center

    Reitzle, Matthias; Korner, Astrid; Vondracek, Fred W.

    2009-01-01

    Recent years have witnessed a growing diversity of career patterns, resulting from the relative decline of stable employment. In the present study of 1368 employed and self-employed German adults career pattern diversity was assessed using nine pictograms. The goal was to identify psychological and demographic correlates of these patterns and to…

  7. Organisational Pattern Driven Recovery Mechanisms

    NASA Astrophysics Data System (ADS)

    Giacomo, Valentina Di; Presenza, Domenico; Riccucci, Carlo

    The process of reaction to system failures and security attacks is strongly influenced by its infrastructural, procedural and organisational settings. Analysis of reaction procedures and practices from different domains (Air Traffic Management, Response to Computer Security Incident, Response to emergencies, recovery in Chemical Process Industry) highlight three key requirements for this activity: smooth collaboration and coordination among responders, accurate monitoring and management of resources and ability to adapt pre-established reaction plans to the actual context. The SERENITY Reaction Mechanisms (SRM) is the subsystem of the SERENITY Run-time Framework aimed to provide SERENITY aware AmI settings (i.e. socio-technical systems with highly distributed dynamic services) with functionalities to implement applications specific reaction strategies. The SRM uses SERENITY Organisational S&D Patterns as run-time models to drive these three key functionalities.

  8. Emerging patterns of epigenomic variation

    PubMed Central

    Milosavljevic, Aleksandar

    2011-01-01

    Fuelled by new sequencing technologies, epigenome mapping projects are revealing epigenomic variation at all levels of biological complexity, from species to cells. Comparisons of methylation profiles among species reveal evolutionary conservation of gene body methylation patterns, pointing to the fundamental role of epigenomes in gene regulation. At the human population level, epigenomic changes provide footprints of the effects of genomic variants within the vast non-protein coding fraction of the genome while comparisons of the epigenomes of parents and their offspring point to quantitative epigenomic parent-of-origin effects confounding classical Mendelian genetics. At the organismal level, comparisons of epigenomes from diverse cell types provide insights into cellular differentiation. Finally, comparisons of epigenomes from monozygotic twins help dissect genetic and environmental influences on human phenotypes and longitudinal comparisons reveal aging-associated epigenomic drift. The development of new bioinformatic frameworks for comparative epigenome analysis is putting epigenome maps within reach of researchers across a wide spectrum of biological disciplines. PMID:21507501

  9. Complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-01-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  10. Anastomosing Rivers are Disequilibrium Patterns

    NASA Astrophysics Data System (ADS)

    Lavooi, E.; de Haas, T.; Kleinhans, M. G.; Makaske, B.; Smith, D. G.

    2010-12-01

    Anastomosing rivers have multiple interconnected channels that enclose floodbasins. Various theories have been proposed to explain this pattern, including an increased discharge conveyance and sediment transport capacity of multiple channels, or, alternatively, a tendency to avulse due to upstream sediment overloading. The former implies an equilibrium pattern whereas the latter implies a temporary increase of the number of channels. Our objective was to test these hypotheses on a well-documented case: the upper Columbia River. We combined a geological approach with physics-based morphological modelling. Three geological sections across the entire valley were constructed based on hand auger data, covering a depth up to 8.6 m corresponding to the last 4000 years, corroborated by 14C dating. The sections were integrated with surface mapping to derive proportions of channel and floodplain sediment volumes and sedimentation rates along the river. Existing sediment transport measurements at a location upstream and downstream of the study area were re-analysed and time-integrated for comparison. A network model was built based on gradually varied flow equations, sediment transport prediction, mass conservation and detailed transverse slope and spiral meander flow effects at the bifurcations. The geological sections show a clear downstream trend of decreasing number of channels and decreasing bed sediment deposition in channels and crevasses, indicating bed sediment overloading from upstream and subsequent avulsions. The measured suspended sediment is much larger than the amount captured in the floodplains, indicating that this is not limiting the aggradation in the valley. Extensive crevasse splays in the upstream section and an increased bed elevation and gradient demonstrate a tendency to avulse due to overloading of bed sediment. The measured bedload transport indeed indicates bed material overloading. The 14C dating confirms that long-term average floodplain

  11. Quantitative patterns in drone wars

    NASA Astrophysics Data System (ADS)

    Garcia-Bernardo, Javier; Dodds, Peter Sheridan; Johnson, Neil F.

    2016-02-01

    Attacks by drones (i.e., unmanned combat air vehicles) continue to generate heated political and ethical debates. Here we examine the quantitative nature of drone attacks, focusing on how their intensity and frequency compare with that of other forms of human conflict. Instead of the power-law distribution found recently for insurgent and terrorist attacks, the severity of attacks is more akin to lognormal and exponential distributions, suggesting that the dynamics underlying drone attacks lie beyond these other forms of human conflict. We find that the pattern in the timing of attacks is consistent with one side having almost complete control, an important if expected result. We show that these novel features can be reproduced and understood using a generative mathematical model in which resource allocation to the dominant side is regulated through a feedback loop.

  12. Changing patterns of wildlife diseases

    USGS Publications Warehouse

    McLean, R.G.

    2001-01-01

    The purpose of this paper was not to analyze the effects of global warming on wildlife disease patterns, but to serve as a springboard for future efforts to identify those wildlife diseases, including zoonotic diseases, that could be influenced the most by warming climates and to encourage the development of models to examine the potential effects. Hales et al. (1999) examined the relationship of the incidence of a vector-borne human disease, Dengue fever, and El Nino southern oscillations for South Pacific Island nations. The development of similar models on specific wildlife diseases which have environmental factors strongly associated with transmission would provide information and options for the future management of our wildlife resources.

  13. The stress pattern of Iceland

    NASA Astrophysics Data System (ADS)

    Ziegler, Moritz; Rajabi, Mojtaba; Heidbach, Oliver; Hersir, Gylfi Páll; Ágústsson, Kristján; Árnadóttir, Sigurveig; Zang, Arno

    2016-04-01

    Iceland is located on the Mid-Atlantic Ridge which is the plate boundary between the Eurasian and the North American plates. It is one of the few places on earth where an active spreading centre is located onshore but the stress pattern has not been extensively investigated so far. In this paper we present a comprehensive compilation of the orientation of maximum horizontal stress (SHmax). In particular we interpret borehole breakouts and drilling induced fractures from borehole image logs in 57 geothermal wells onshore Iceland. The borehole results are combined with other stress indicators including earthquake focal mechanism solutions, geological information and overcoring measurements resulting in a dataset with 495 data records for the SHmax orientation. The reliability of each indicator is assessed according to the quality criteria of the World Stress Map project. The majority of SHmax orientation data records in Iceland is derived from earthquake focal mechanism solutions (35%) and geological fault slip inversions (26%). 20% of the data are borehole related stress indicators. In addition minor shares of SHmax orientations are compiled, amongst others, from focal mechanism inversions and the alignment of fissure eruptions. The results show that the SHmax orientations derived from different depths and stress indicators are consistent with each other. The resulting pattern of the present-day stress in Iceland has four distinct subsets of SHmax orientations. The SHmax orientation is parallel to the rift axes in the vicinity of the active spreading regions. It changes from NE-SW in the South to approximately N-S in central Iceland and NNW-SSE in the North. In the Westfjords which is located far away from the ridge the regional SHmax rotates and is parallel to the plate motion.

  14. Subsymmetries predict auditory and visual pattern complexity.

    PubMed

    Toussaint, Godfried T; Beltran, Juan F

    2013-01-01

    A mathematical measure of pattern complexity based on subsymmetries possessed by the pattern, previously shown to correlate highly with empirically derived measures of cognitive complexity in the visual domain, is found to also correlate significantly with empirically derived complexity measures of perception and production of auditory temporal and musical rhythmic patterns. Not only does the subsymmetry measure correlate highly with the difficulty of reproducing the rhythms by tapping after listening to them, but also the empirical measures exhibit similar behavior, for both the visual and auditory patterns, as a function of the relative number of subsymmetries present in the patterns. PMID:24494441

  15. Composite patterning devices for soft lithography

    DOEpatents

    Rogers, John A.; Menard, Etienne

    2007-03-27

    The present invention provides methods, devices and device components for fabricating patterns on substrate surfaces, particularly patterns comprising structures having microsized and/or nanosized features of selected lengths in one, two or three dimensions. The present invention provides composite patterning devices comprising a plurality of polymer layers each having selected mechanical properties, such as Young's Modulus and flexural rigidity, selected physical dimensions, such as thickness, surface area and relief pattern dimensions, and selected thermal properties, such as coefficients of thermal expansion, to provide high resolution patterning on a variety of substrate surfaces and surface morphologies.

  16. Learning Decision Trees over Erasing Pattern Languages

    NASA Astrophysics Data System (ADS)

    Mukouchi, Yasuhito; Sato, Masako

    2008-07-01

    In this paper, we consider a learning problem of decision trees over erasing patterns from positive examples in the framework of identification in the limit due to Gold and Angluin. An erasing pattern is a string pattern with constant symbols and erasable variables. A decision tree over erasing patterns can be applied to identify or express transmembrane domains of amino acid sequences, and gives intuitive knowledge expressions. We first show that the ordinary decision trees with height 1 over erasing regular patterns are learnable but those with height at most 2 are not learnable from positive examples. Then we introduce a co-pattern pc for an erasing pattern p, and we redefine the language of a decision tree over erasing patterns as a language obtainable by finitely many applications of union operations and intersection operations to the languages of erasing patterns and co-patterns. Under the new definition of decision trees, we show that these decision trees with height at most n are learnable from positive examples. Moreover, we investigate efficient learning algorithms for decision trees with height 1. Terada et al. discussed the same problem for decision trees over nonerasing patterns, and the results obtained in the present work are natural extensions of Terada's results.

  17. Mechanically patterning the embryonic airway epithelium

    PubMed Central

    Varner, Victor D.; Gleghorn, Jason P.; Miller, Erin; Radisky, Derek C.; Nelson, Celeste M.

    2015-01-01

    Collections of cells must be patterned spatially during embryonic development to generate the intricate architectures of mature tissues. In several cases, including the formation of the branched airways of the lung, reciprocal signaling between an epithelium and its surrounding mesenchyme helps generate these spatial patterns. Several molecular signals are thought to interact via reaction-diffusion kinetics to create distinct biochemical patterns, which act as molecular precursors to actual, physical patterns of biological structure and function. Here, however, we show that purely physical mechanisms can drive spatial patterning within embryonic epithelia. Specifically, we find that a growth-induced physical instability defines the relative locations of branches within the developing murine airway epithelium in the absence of mesenchyme. The dominant wavelength of this instability determines the branching pattern and is controlled by epithelial growth rates. These data suggest that physical mechanisms can create the biological patterns that underlie tissue morphogenesis in the embryo. PMID:26170292

  18. A Formal Basis for Safety Case Patterns

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Pai, Ganesh

    2013-01-01

    By capturing common structures of successful arguments, safety case patterns provide an approach for reusing strategies for reasoning about safety. In the current state of the practice, patterns exist as descriptive specifications with informal semantics, which not only offer little opportunity for more sophisticated usage such as automated instantiation, composition and manipulation, but also impede standardization efforts and tool interoperability. To address these concerns, this paper gives (i) a formal definition for safety case patterns, clarifying both restrictions on the usage of multiplicity and well-founded recursion in structural abstraction, (ii) formal semantics to patterns, and (iii) a generic data model and algorithm for pattern instantiation. We illustrate our contributions by application to a new pattern, the requirements breakdown pattern, which builds upon our previous work

  19. Systematic physical verification with topological patterns

    NASA Astrophysics Data System (ADS)

    Dai, Vito; Lai, Ya-Chieh; Gennari, Frank; Teoh, Edward; Capodieci, Luigi

    2014-03-01

    Design rule checks (DRC) are the industry workhorse for constraining design to ensure both physical and electrical manufacturability. Where DRCs fail to fully capture the concept of manufacturability, pattern-based approaches, such as DRC Plus, fill the gap using a library of patterns to capture and identify problematic 2D configurations. Today, both a DRC deck and a pattern matching deck may be found in advanced node process development kits. Major electronic design automation (EDA) vendors offer both DRC and pattern matching solutions for physical verification; in fact, both are frequently integrated into the same physical verification tool. In physical verification, DRCs represent dimensional constraints relating directly to process limitations. On the other hand, patterns represent the 2D placement of surrounding geometries that can introduce systematic process effects. It is possible to combine both DRCs and patterns in a single topological pattern representation. A topological pattern has two separate components: a bitmap representing the placement and alignment of polygon edges, and a vector of dimensional constraints. The topological pattern is unique and unambiguous; there is no code to write, and no two different ways to represent the same physical structure. Furthermore, markers aligned to the pattern can be generated to designate specific layout optimizations for improving manufacturability. In this paper, we describe how to do systematic physical verification with just topological patterns. Common mappings between traditional design rules and topological pattern rules are presented. We describe techniques that can be used during the development of a topological rule deck such as: taking constraints defined on one rule, and systematically projecting it onto other related rules; systematically separating a single rule into two or more rules, when the single rule is not sufficient to capture manufacturability constraints; creating test layout which

  20. Root Patterns in Heterogeneous Soils

    NASA Astrophysics Data System (ADS)

    Dara, A.; Moradi, A. B.; Carminati, A.; Oswald, S. E.

    2010-12-01

    Heterogeneous water availability is a typical characteristic of soils in which plant roots grow. Despite the intrinsic heterogeneity of soil-plant water relations, we know little about the ways how plants respond to local environmental quality. Furthermore, increasing use of soil amendments as partial water reservoirs in agriculture calls for a better understanding of plant response to soil heterogeneity. Neutron radiography is a non-invasive imaging that is highly sensitive to water and root distribution and that has high capability for monitoring spatial and temporal soil-plant water relations in heterogeneous systems. Maize plants were grown in 25 x 30 x 1 cm aluminum slabs filled with sandy soil. On the right side of the compartments a commercial water absorbent (Geohumus) was mixed with the soil. Geohumus was distributed with two patterns: mixed homogeneously with the soil, and arranged as 1-cm diameter aggregates (Fig. 1). Two irrigation treatments were applied: sufficient water irrigation and moderate water stress. Neutron radiography started 10 days after planting and has been performed twice a day for one week. At the end of the experiment, the containers were opened, the root were removed and dry root weight in different soil segments were measured. Neutron radiography showed root growth tendency towards Geohumus treated parts and preferential water uptake from Geohumus aggregates. Number and length of fine lateral roots were lower in treated areas compared to the non-treated zone and to control soil. Although corn plants showed an overall high proliferation towards the soil water sources, they decreased production of branches and fine root when water was more available near the main root parts. However there was 50% higher C allocation in roots grown in Geohumus compartments, as derived by the relative dry weight of root. The preferential C allocation in treated regions was higher when plants grew under water stress. We conclude that in addition to the

  1. Pattern activation/recognition theory of mind.

    PubMed

    du Castel, Bertrand

    2015-01-01

    In his 2012 book How to Create a Mind, Ray Kurzweil defines a "Pattern Recognition Theory of Mind" that states that the brain uses millions of pattern recognizers, plus modules to check, organize, and augment them. In this article, I further the theory to go beyond pattern recognition and include also pattern activation, thus encompassing both sensory and motor functions. In addition, I treat checking, organizing, and augmentation as patterns of patterns instead of separate modules, therefore handling them the same as patterns in general. Henceforth I put forward a unified theory I call "Pattern Activation/Recognition Theory of Mind." While the original theory was based on hierarchical hidden Markov models, this evolution is based on their precursor: stochastic grammars. I demonstrate that a class of self-describing stochastic grammars allows for unifying pattern activation, recognition, organization, consistency checking, metaphor, and learning, into a single theory that expresses patterns throughout. I have implemented the model as a probabilistic programming language specialized in activation/recognition grammatical and neural operations. I use this prototype to compute and present diagrams for each stochastic grammar and corresponding neural circuit. I then discuss the theory as it relates to artificial network developments, common coding, neural reuse, and unity of mind, concluding by proposing potential paths to validation.

  2. Pattern activation/recognition theory of mind

    PubMed Central

    du Castel, Bertrand

    2015-01-01

    In his 2012 book How to Create a Mind, Ray Kurzweil defines a “Pattern Recognition Theory of Mind” that states that the brain uses millions of pattern recognizers, plus modules to check, organize, and augment them. In this article, I further the theory to go beyond pattern recognition and include also pattern activation, thus encompassing both sensory and motor functions. In addition, I treat checking, organizing, and augmentation as patterns of patterns instead of separate modules, therefore handling them the same as patterns in general. Henceforth I put forward a unified theory I call “Pattern Activation/Recognition Theory of Mind.” While the original theory was based on hierarchical hidden Markov models, this evolution is based on their precursor: stochastic grammars. I demonstrate that a class of self-describing stochastic grammars allows for unifying pattern activation, recognition, organization, consistency checking, metaphor, and learning, into a single theory that expresses patterns throughout. I have implemented the model as a probabilistic programming language specialized in activation/recognition grammatical and neural operations. I use this prototype to compute and present diagrams for each stochastic grammar and corresponding neural circuit. I then discuss the theory as it relates to artificial network developments, common coding, neural reuse, and unity of mind, concluding by proposing potential paths to validation. PMID:26236228

  3. Pattern activation/recognition theory of mind.

    PubMed

    du Castel, Bertrand

    2015-01-01

    In his 2012 book How to Create a Mind, Ray Kurzweil defines a "Pattern Recognition Theory of Mind" that states that the brain uses millions of pattern recognizers, plus modules to check, organize, and augment them. In this article, I further the theory to go beyond pattern recognition and include also pattern activation, thus encompassing both sensory and motor functions. In addition, I treat checking, organizing, and augmentation as patterns of patterns instead of separate modules, therefore handling them the same as patterns in general. Henceforth I put forward a unified theory I call "Pattern Activation/Recognition Theory of Mind." While the original theory was based on hierarchical hidden Markov models, this evolution is based on their precursor: stochastic grammars. I demonstrate that a class of self-describing stochastic grammars allows for unifying pattern activation, recognition, organization, consistency checking, metaphor, and learning, into a single theory that expresses patterns throughout. I have implemented the model as a probabilistic programming language specialized in activation/recognition grammatical and neural operations. I use this prototype to compute and present diagrams for each stochastic grammar and corresponding neural circuit. I then discuss the theory as it relates to artificial network developments, common coding, neural reuse, and unity of mind, concluding by proposing potential paths to validation. PMID:26236228

  4. Gender differences in collaboration patterns

    NASA Astrophysics Data System (ADS)

    Zeng, Xiaohan; Duch, Jordi; Sales-Pardo, Marta; Radicchi, Filippo; Ribeiro, Haroldo V.; Woodruff, Teresa K.; Amaral, Luis A. N.

    2014-03-01

    Collaboration plays an increasingly important role in research productivity and impact. However, it remains unclear whether female and male researchers in science, technology, engineering and mathematical (STEM) disciplines differ significantly from each other in their collaboration propensity. Here, we report on an empirical analysis of the complete publication records of 3,920 faculty members in six STEM disciplines at selected top U.S. research universities. We find that while female faculty have significantly fewer co-authors over their careers, this can be fully explained by their lower number of publications. Indeed, we also find that females tend to distribute their co-authoring opportunities among their co-authors more evenly than males do. Our results suggest that females have had a greater propensity to collaborate, in order to succeed in a historically men-dominated academic world. Surprisingly, we find evidence that in molecular biology there has been a gender segregation within sub-disciplines. Female faculty in molecular biology departments tend to collaborate with smaller teams and publish in journals and fields where typical team size is smaller. Our results identify gender-specific collaborative behaviors as well as disciplines with distinct patterns. The authors thank the support from the following grants: NSF SBE 0624318, NSF IIS 0830388, and Spanish DGICYT under project FIS2010-18639.

  5. Pattern Formation in Driven Systems

    NASA Astrophysics Data System (ADS)

    Klymko, Katherine

    Model colloidal particles of two types, driven in opposite directions, will in two dimensions segregate into lanes, a phenomenon studied extensively by Lowen and co-workers [Dzubiella et al. Phys. Rev. E 65, 021402 (2002)]. We have simulated mixtures of oppositely-driven particles using three numerical protocols. We find that laning results from enhanced diffusion, in the direction perpendicular to the drive, of particles surrounded by particles of the opposite type, consistent with the observation of Vissers et al. [Soft Matter 7, 6, 2352 (2011)]. By comparing protocols we find that enhanced diffusion follows from a simple geometrical constraint: oppositely-driven particles must, in the time taken to encounter each other in the direction of the drive, diffuse in the perpendicular direction by about one particle diameter. This constraint implies that the effective lateral diffusion constant grows linearly with drive speed and as the square root of the packing fraction, a prediction supported by our numerics. By invoking an analogy between hard particles with environment-dependent mobilities and mutually attractive particles we argue that there exists an equilibrium system whose pattern-forming properties are similar to those of the driven system. Katherine Klymko acknowledges support from the NSF Graduate Research Fellowship.

  6. Pattern prediction in EUV resists

    NASA Astrophysics Data System (ADS)

    Biafore, John J.; Smith, Mark D.; Wallow, Tom; Nalleau, Patrick; Blankenship, David; Deng, Yunfei

    2009-12-01

    Accurate and flexible simulation methods may be used to further a researcher's understanding of how complex resist effects influence the patterning of critical structures. In this work, we attempt to gain insight into the behavior of a state-of-the-art EUV resist through the use of stochastic resist modeling. The statistics of photon and molecule counting are discussed. The acid generation mechanism at EUV is discussed. At lambda = 13.5 nm, the acid generation mechanism may be similar to that found in electron beam resists: acid generators are hypothesized to be activated by secondary electrons yielded by ionization of the resist matrix by high-energy EUV photons, suggesting that acid generators may be activated some distance from the absorption site. A discrete, probabilistic ionization and electron scattering model for PAG conversion at EUV is discussed. The simulated effect of resist absorbance at EUV upon doseto- size and line-width roughness is shown. The model's parameterized fit to experimental data from a resist irradiated EUV are shown. Predictions of statistical resist responses such as CD distribution and line-width roughness are compared with experimental data.

  7. Suction patterns in preterm infants.

    PubMed

    Martell, M; Martínez, G; González, M; Díaz Rosselló, J L

    1993-01-01

    The suction pattern for breast and bottle feeding in two groups of preterm infants is described. The time elapsed between birth and the moment of suction was longer in preterm neonates born at lower gestational ages for both groups studied, breast and bottle fed (figure 1). The evolution of suckling in breastfeeding was analyzed in a composite study (longitudinal and transverse) in a group of 16 neonates starting from 32 weeks of gestation. The velocity of milk extraction during suckling varied with gestational age. It was uniform at lower gestational ages, then it became faster in the first minutes and at the 36th week, it was very similar to that of mature neonates (figure 2 and table I). The evaluation of bottle feeding was performed in a transverse study in 46 preterm neonates which had been exclusively bottle fed during 1 or 2 weeks. All of them had previously been fed using an orogastric tube. Nourishing time was shorter than in breastfeeding; the average duration was 3.7 minutes (table II). The greatest volume was ingested in the first minute, 40% (range between 44 and 25%) (figure 3). The frequency of suction did not change the duration of feeding, but it was found that the efficiency of suction (number of suctions to ingest 1 cc) was significantly lower in the first minute (Anova, p < 0.05) (figure 4).

  8. Proximodistal patterning during limb regeneration.

    PubMed

    Echeverri, Karen; Tanaka, Elly M

    2005-03-15

    Regeneration is an ability that has been observed extensively throughout metazoan phylogeny. Amongst vertebrates, the urodele amphibians stand out for their exceptional capacity to regenerate body parts such as the limb. During this process, only the missing portion of the limb is precisely replaced--amputation in the upper arm results in regeneration of the entire limb, while amputation at the wrist produces a hand. Limb regeneration occurs through the formation of a local proliferative zone called the blastema. Here, we examine how proximodistal identity is established in the blastema. Using cell marking and transplantation experiments, we show that distal identities have already been established in the earliest stages of blastemas examined. Transplantation of cells into new environments is not sufficient to respecify cell identity. However, overexpression of the CD59, a cell surface molecule previously implicated in proximodistal identity during limb regeneration, causes distal blastema cells to translocate to a more proximal location and causes defects in the patterning of the distal elements of the regenerate. We suggest a model for the limb regeneration blastema where by 4 days post-amputation the blastema is already divided into distinct growth zones; the cells of each zone are already specified to give rise to upper arm, lower arm, and hand. PMID:15733667

  9. Bond failure patterns in vivo.

    PubMed

    Linklater, Rognvald A; Gordon, Peter H

    2003-05-01

    The aim of this study was to identify the presence and pattern of differences in bond failure between tooth types in vivo when bonding orthodontic brackets with the no-mix orthodontic composite adhesive Right-On. In vivo bond failure for a single operator was recorded for 108 consecutive patients undergoing fixed-appliance orthodontic treatment. The bond failure data were analyzed by survival analysis. Time to first failure or censorship was recorded for each bonded attachment. Overall failure in the sample matched previous clinical studies but conflicted with previous ex vivo bond strength data. Mandibular and posterior teeth had significantly higher rates of failure than did maxillary and anterior teeth. The type of attachment used had a significant effect on bond survival. The results of this study confirm that in vivo bond survival is not uniform for all teeth. Comparisons between the findings of this study and those of a previous ex vivo study by the same authors failed to validate ex vivo bond strength testing as clinically relevant.

  10. Changes in patterns of risk.

    PubMed

    Hankins, C

    1998-06-01

    Against the background of debate about the nature of risk in relation to HIV transmission, and resultant changes in risk discourse from risk group to risk behaviour to risk situation, declines in the velocity of HIV spread are being documented in countries with high levels of political commitment and multi-sectoral approaches. Biological markers of sexual activity such as sexually transmitted disease incidence and HIV prevalence corroborate reports that young adults in Uganda and Thailand are increasingly adopting preventive behaviours. Risk perception, perceived social and community norms and self-efficacy influence behavioural change, but structural and contextual factors, including resource constraints affecting HIV prevention programmes and the treatment of sexually transmitted diseases, and social marginalization and stigmatization affecting access of vulnerable populations to the means of prevention play determinant roles. Both patterns of risk for HIV infection and our understanding of them are evolving. More research is required to gain knowledge and understanding of factors such as partner concurrency as well as cultural and socio-economic determinants and contextual underpinnings of sexual and drug injecting networks. This is an essential first step to mobilizing communities to take action at the individual, partnership and community levels to reduce risk.

  11. Cell patterning with mucin biopolymers

    PubMed Central

    Crouzier, T.; Jang, H.; Ahn, J.; Stocker, R.; Ribbeck, K.

    2014-01-01

    The precise spatial control of cell adhesion to surfaces is an endeavor that has enabled discoveries in cell biology and new possibilities in tissue engineering. The generation of cell-repellent surfaces currently requires advanced chemistry techniques and could be simplified. Here we show that mucins, glycoproteins of high structural and chemical complexity, spontaneously adsorb on hydrophobic substrates to form coatings that prevent the surface adhesion of mammalian epithelial cells, fibroblasts, and myoblasts. These mucin coatings can be patterned with micrometer precision using a microfluidic device, and are stable enough to support myoblast differentiation over seven days. Moreover, our data indicate that the cell-repellent effect is dependent on mucin-associated glycans because their removal results in a loss of effective cell-repulsion. Last, we show that a critical surface density of mucins, which is required to achieve cell-repulsion, is efficiently obtained on hydrophobic surfaces, but not on hydrophilic glass surfaces. However, this limitation can be overcome by coating glass with hydrophobic fluorosilane. We conclude that mucin biopolymers are attractive candidates to control cell adhesion on surfaces. PMID:23980712

  12. Advanced precision expendable pattern casting technology. 1994 Summary report

    SciTech Connect

    1995-05-01

    Casting technology is described. The following areas are reported on: precision pattern production; pattern coating; sand fill and compaction; pattern gating; mechanical properties; and technology transfer efforts.

  13. 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.

  14. Orthogonal patterns in binary neural networks

    NASA Technical Reports Server (NTRS)

    Baram, Yoram

    1988-01-01

    A binary neural network that stores only mutually orthogonal patterns is shown to converge, when probed by any pattern, to a pattern in the memory space, i.e., the space spanned by the stored patterns. The latter are shown to be the only members of the memory space under a certain coding condition, which allows maximum storage of M=(2N) sup 0.5 patterns, where N is the number of neurons. The stored patterns are shown to have basins of attraction of radius N/(2M), within which errors are corrected with probability 1 in a single update cycle. When the probe falls outside these regions, the error correction capability can still be increased to 1 by repeatedly running the network with the same probe.

  15. Excitation and Characterization of Chladni Plate Patterns

    NASA Astrophysics Data System (ADS)

    Bourke, Shannon; Behringer, Ernest

    2011-04-01

    When a thin metal plate with a small amount of sand on it is made to vibrate, aesthetically pleasing sand patterns can form along the nodal lines of the plate. These symmetric patterns are called Chladni Patterns. Students taking PHY 101 Physical Science in the Arts at Eastern Michigan University create these patterns by pulling a violin bow across the edge of a plate, or by using a mechanical oscillator to drive the center of a plate. These two methods only allow a small subset of all possible points on the plate to be excited. We designed and built an electronic device that allows its user to excite the plate at any point. We present patterns created with this electronic device and other methods, and describe ways to model the observed patterns.

  16. Minimal perceptrons for memorizing complex patterns

    NASA Astrophysics Data System (ADS)

    Pastor, Marissa; Song, Juyong; Hoang, Danh-Tai; Jo, Junghyo

    2016-11-01

    Feedforward neural networks have been investigated to understand learning and memory, as well as applied to numerous practical problems in pattern classification. It is a rule of thumb that more complex tasks require larger networks. However, the design of optimal network architectures for specific tasks is still an unsolved fundamental problem. In this study, we consider three-layered neural networks for memorizing binary patterns. We developed a new complexity measure of binary patterns, and estimated the minimal network size for memorizing them as a function of their complexity. We formulated the minimal network size for regular, random, and complex patterns. In particular, the minimal size for complex patterns, which are neither ordered nor disordered, was predicted by measuring their Hamming distances from known ordered patterns. Our predictions agree with simulations based on the back-propagation algorithm.

  17. Pattern Selection by Dynamical Biochemical Signals

    PubMed Central

    Palau-Ortin, David; Formosa-Jordan, Pau; Sancho, José M.; Ibañes, Marta

    2015-01-01

    The development of multicellular organisms involves cells to decide their fate upon the action of biochemical signals. This decision is often spatiotemporally coordinated such that a spatial pattern arises. The dynamics that drive pattern formation usually involve genetic nonlinear interactions and positive feedback loops. These complex dynamics may enable multiple stable patterns for the same conditions. Under these circumstances, pattern formation in a developing tissue involves a selection process: why is a certain pattern formed and not another stable one? Herein we computationally address this issue in the context of the Notch signaling pathway. We characterize a dynamical mechanism for developmental selection of a specific pattern through spatiotemporal changes of the control parameters of the dynamics, in contrast to commonly studied situations in which initial conditions and noise determine which pattern is selected among multiple stable ones. This mechanism can be understood as a path along the parameter space driven by a sequence of biochemical signals. We characterize the selection process for three different scenarios of this dynamical mechanism that can take place during development: the signal either 1) acts in all the cells at the same time, 2) acts only within a cluster of cells, or 3) propagates along the tissue. We found that key elements for pattern selection are the destabilization of the initial pattern, the subsequent exploration of other patterns determined by the spatiotemporal symmetry of the parameter changes, and the speeds of the path compared to the timescales of the pattern formation process itself. Each scenario enables the selection of different types of patterns and creates these elements in distinct ways, resulting in different features. Our approach extends the concept of selection involved in cellular decision-making, usually applied to cell-autonomous decisions, to systems that collectively make decisions through cell

  18. The perception of prominence patterns.

    PubMed

    Kohler, Klaus J

    2008-01-01

    The term 'stress' is used to refer to the perceptual salience at certain places in strings of syllables, but it has several different referents: (a) relative syllable salience in an utterance; this is syllable-, not word-oriented; (b) stress in a word; this is part of the lexical phonology; (c) stressing of words in utterances for various aspects of propositional and expressive meaning, often called 'accent(uation)'. Referents b and c are word- and meaning-oriented. In this article, the terms are more stringently defined. 'Stress' is only used to refer to a lexical stress position (referent b), i.e. a syllable in a word that becomes the docking place for various types of 'accent' to weight words in utterances (referent c). 'Stress' has no physical attributes by itself. 'Prominence' refers to the patterns of salience in syllable strings (referent a). The article reports results of an experiment in prominence perception of the logatome baba, in which the physical parameters F0, syllabic duration, and overall acoustic energy were systematically varied across the bisyllable. Sixteen German subjects had to indicate, by pressing buttons of a computerized reaction time device, whether the first or the second syllable was more prominent. F(0) was a more powerful cue than the other two. Equal syllable duration on a monotone resulted in more first-syllable judgements, which could be counteracted by a slightly falling F(0) contour on the second syllable to reach equal response frequencies for the two syllables. This ties in with Lehiste's earlier findings that F(0) movement increases the perception of duration. Extrapolating from the results, a research programme for prominence perception is developed that will eventually shed new light on the investigation into the nature and manifestation of speech rhythm. PMID:19221454

  19. Writing magnetic patterns with surface acoustic waves

    SciTech Connect

    Li, Weiyang; Buford, Benjamin; Jander, Albrecht; Dhagat, Pallavi

    2014-05-07

    A novel patterning technique that creates magnetization patterns in a continuous magnetostrictive film with surface acoustic waves is demonstrated. Patterns of 10 μm wide stripes of alternating magnetization and a 3 μm dot of reversed magnetization are written using standing and focusing acoustic waves, respectively. The magnetization pattern is size-tunable, erasable, and rewritable by changing the magnetic field and acoustic power. This versatility, along with its solid-state implementation (no moving parts) and electronic control, renders it as a promising technique for application in magnetic recording, magnonic signal processing, magnetic particle manipulation, and spatial magneto-optical modulation.

  20. Associative Pattern Recognition In Analog VLSI Circuits

    NASA Technical Reports Server (NTRS)

    Tawel, Raoul

    1995-01-01

    Winner-take-all circuit selects best-match stored pattern. Prototype cascadable very-large-scale integrated (VLSI) circuit chips built and tested to demonstrate concept of electronic associative pattern recognition. Based on low-power, sub-threshold analog complementary oxide/semiconductor (CMOS) VLSI circuitry, each chip can store 128 sets (vectors) of 16 analog values (vector components), vectors representing known patterns as diverse as spectra, histograms, graphs, or brightnesses of pixels in images. Chips exploit parallel nature of vector quantization architecture to implement highly parallel processing in relatively simple computational cells. Through collective action, cells classify input pattern in fraction of microsecond while consuming power of few microwatts.

  1. Modeling spatial patterns in the visual cortex

    NASA Astrophysics Data System (ADS)

    Daza C., Yudy Carolina; Tauro, Carolina B.; Tamarit, Francisco A.; Gleiser, Pablo M.

    2014-10-01

    We propose a model for the formation of patterns in the visual cortex. The dynamical units of the model are Kuramoto phase oscillators that interact through a complex network structure embedded in two dimensions. In this way the strength of the interactions takes into account the geographical distance between units. We show that for different parameters, clustered or striped patterns emerge. Using the structure factor as an order parameter we are able to quantitatively characterize these patterns and present a phase diagram. Finally, we show that the model is able to reproduce patterns with cardinal preference, as observed in ferrets.

  2. Automatic Behavior Pattern Classification for Social Robots

    NASA Astrophysics Data System (ADS)

    Prieto, Abraham; Bellas, Francisco; Caamaño, Pilar; Duro, Richard J.

    In this paper, we focus our attention on providing robots with a system that allows them to automatically detect behavior patterns in other robots, as a first step to introducing social responsive robots. The system is called ANPAC (Automatic Neural-based Pattern Classification). Its main feature is that ANPAC automatically adjusts the optimal processing window size and obtains the appropriate features through a dimensional transformation process that allow for the classification of behavioral patterns of large groups of entities from perception datasets. Here we present the basic elements and operation of ANPAC, and illustrate its applicability through the detection of behavior patterns in the motion of flocks.

  3. Self-assembly of lithographically patterned nanoparticles

    PubMed Central

    Cho, Jeong-Hyun; Gracias, David H.

    2009-01-01

    The construction of three dimensional (3D) objects, with any desired surface patterns, is both critical to and easily achieved in macroscale, science and engineering. However, on the nanoscale, 3D fabrication is limited to particles with only very limited surface patterning. Here, we demonstrate a self-assembly strategy that harnesses the strengths of well established 2D nanoscale patterning techniques and additionally enables the construction of stable 3D polyhedral nanoparticles. As a proof of the concept, we self-assembled cubic particles with sizes as small as 100 nm and with specific and lithographically defined surface patterns. PMID:19681638

  4. Patterns - “A crime solver”

    PubMed Central

    Nagasupriya, A; Dhanapal, Raghu; Reena, K; Saraswathi, TR; Ramachandran, CR

    2011-01-01

    Objective: This study is intended to analyze the predominant pattern of lip and finger prints in males and females and to correlate lip print and finger print for gender identity. Materials and Methods: The study sample comprised of 200 students of Vishnu Dental College, Bhimavaram, Andhra Pradesh, 100 males and 100 females aged between 18 to 27 years. Brown/pink colored lip stick was applied on the lips and the subject was asked to spread it uniformly over the lips. Lip prints were traced in the normal rest position of the lips with the help of cellophane tape. The imprint of the left thumb was taken on a white chart sheet and visualized using magnifying lens. While three main types of finger prints are identified, the classification of lip prints is simplified into branched, reticular, and vertical types. Association between lip prints and finger prints was statistically tested using Chi-square test. Results: This study showed that lip and finger patterns did not reveal statistically significant results within the gender. The correlation between lip and finger patterns for gender identification, was statistically significant. In males, branched type of lip pattern associated with arch, loop, and whorl type of finger pattern was most significant. In females, vertical lip pattern associated with arch finger pattern and reticular lip pattern associated with whorl finger patterns were most significant. Conclusion: We conclude that a correlative study between the lip print and finger print will be very useful in forensic science for gender identification. PMID:22022131

  5. Evaluation of ALE processes for patterning

    NASA Astrophysics Data System (ADS)

    Papalia, J. M.; Marchack, N.; Bruce, R. L.; Miyazoe, H.; Engelmann, S. U.; Joseph, E. A.

    2016-03-01

    The need for continued device scaling along with the increasing demand for high precision have lead to the development of atomic layer etch processes in semiconductor manufacturing. We have tested this new methodology with regard to patterning applications. While these new plasma-enhanced atomic layer etch (PE-ALE) processes show encouraging results, most patterning applications are best realized by optimizations through discharge chemistry and/or plasma parameters. While PE-ALE approaches seem to have limited success for trilayer patterning applications, significant improvements were obtained when applying them to small pitch. In particular the increased selectivity to OPL seems to offer a potential benefit for patterning high aspect ratio features.

  6. Plasma stencilling methods for cell patterning.

    PubMed

    Frimat, Jean-Philippe; Menne, Heike; Michels, Antje; Kittel, Silke; Kettler, Raffael; Borgmann, Sabine; Franzke, Joachim; West, Jonathan

    2009-10-01

    In this paper we describe plasma stencilling techniques for patterning 10 mammalian cell lines on hydrophobic and cell repellent poly(dimethylsiloxane) (PDMS), methylated glass and bacterial grade polystyrene surfaces. An air plasma produced with a Tesla generator operating at atmospheric pressure was used with microengineered stencils for patterned surface oxidation, selectively transforming the surface to a hydrophilic state to enable cell adhesion and growth. Plasma stencilling obviates the need for directly patterning cell adhesion molecules. Instead, during cell culture, adhesion proteins from the media assemble in a bioactive form on the hydrophilic regions. Critically, the removal of protein patterning prior to cell culture provides the option to also use PDMS-PDMS plasma bonding to incorporate cell patterns within microfluidic systems. Linear patterns were generated using PDMS microchannel stencils, and polyimide stencils with through holes were used for the production of cellular arrays. For the production of smaller cellular arrays, a novel microcapillary-based dielectric barrier discharge system was developed. A numerical method to characterise the cell patterns is also introduced and was used to demonstrate that plasma stencilling is highly effective, with complete patterns confined during long term cell culture (>10 days). In summary, plasma stencilling is simple, rapid, inexpensive, reproducible and a potentially universal cell line patterning capability.

  7. Word recognition using ideal word patterns

    NASA Astrophysics Data System (ADS)

    Zhao, Sheila X.; Srihari, Sargur N.

    1994-03-01

    The word shape analysis approach to text recognition is motivated by discoveries in psychological studies of the human reading process. It attempts to describe and compare the shape of the word as a whole object without trying to segment and recognize the individual characters, so it bypasses the errors committed in character segmentation and classification. However, the large number of classes and large variation and distortion expected in all patterns belonging to the same class make it difficult for conventional, accurate, pattern recognition approaches. A word shape analysis approach using ideal word patterns to overcome the difficulty and improve recognition performance is described in this paper. A special word pattern which characterizes a word class is extracted from different sample patterns of the word class and stored in memory. Recognition of a new word pattern is achieved by comparing it with the special pattern of each word class called ideal word pattern. The process of generating the ideal word pattern of each word class is proposed. The algorithm was tested on a set of machine printed gray scale word images which included a wide range of print types and qualities.

  8. Pattern Organization of Premature Ventricular Heartbeats

    NASA Astrophysics Data System (ADS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Ivanov, Plamen; Stanley, H. Eugene; Stanley, Gene; Goldberger, Ary L.

    2000-03-01

    Increased number of premature (abnormal) ventricular beats in a record of heartbeat intervals are known to be associated with an advanced stage of pathology (e.g. congestive heart failure). These abnormal beats usually occur in repeated bursts for relatively short periods of time. Here we ask the question if particular abnormal patterns appear throughout records of heartbeat intervals. We study the temporal organization of specific patterns of ventricular beats in long 24 hour records and their relation to different stages of disease. We analyze the statistical properties of such patterns and combination of patterns by means of crosscorrelation matrices.

  9. Pattern Search Methods for Linearly Constrained Minimization

    NASA Technical Reports Server (NTRS)

    Lewis, Robert Michael; Torczon, Virginia

    1998-01-01

    We extend pattern search methods to linearly constrained minimization. We develop a general class of feasible point pattern search algorithms and prove global convergence to a Karush-Kuhn-Tucker point. As in the case of unconstrained minimization, pattern search methods for linearly constrained problems accomplish this without explicit recourse to the gradient or the directional derivative. Key to the analysis of the algorithms is the way in which the local search patterns conform to the geometry of the boundary of the feasible region.

  10. On the Local Convergence of Pattern Search

    NASA Technical Reports Server (NTRS)

    Dolan, Elizabeth D.; Lewis, Robert Michael; Torczon, Virginia; Bushnell, Dennis M. (Technical Monitor)

    2000-01-01

    We examine the local convergence properties of pattern search methods, complementing the previously established global convergence properties for this class of algorithms. We show that the step-length control parameter which appears in the definition of pattern search algorithms provides a reliable asymptotic measure of first-order stationarity. This gives an analytical justification for a traditional stopping criterion for pattern search methods. Using this measure of first-order stationarity, we analyze the behavior of pattern search in the neighborhood of an isolated local minimizer. We show that a recognizable subsequence converges r-linearly to the minimizer.

  11. EUV contact holes and pillars patterning

    NASA Astrophysics Data System (ADS)

    Park, Sarohan; De Simone, Danilo; Tao, Zheng; Vandenberghe, Geert; Hyun, Yoonsuk; Kim, Seo-Min; Lim, Chang-Moon

    2015-03-01

    In this paper, we will present the experimental comparison results on contact holes (CHs) and pillars patterning in EUV lithography with several candidate processes. Firstly, we have compared the normalized image log-slope (NILS), local critical dimension uniformity (LCDU) and dose-to-size (DtS) with respect to positive tone imaging (PTI) and negative tone imaging (NTI) process by EUV stochastic simulation. From the simulation results, we found that NTI process has higher absorbed photon density that can reduce the DtS and the LCDU of pillars pattern is improved with higher NILS compared to CHs patterning with similar DtS. So we have experimentally evaluated the pillars patterning process with 0.25NA EUV scanner system and compared the process margin, LCDU and DtS with the same parameters of the CHs pattering process. Further, we have demonstrated the CHs patterning with reverse process from pillars by using the dry development rinse process (DDRP). Different to the simulation results, the experimental LCDU results of pillars pattern and CHs pattern by DDRP show worse values comparing with the reference resist CHs pattern. In order to analyze these results, we have investigated the effect of flare, target CD, PR thickness and mask stack of the experimental conditions. Furthermore, we have evaluated the pillar patterning with NTD resist and by DDRP.

  12. Fictive motor patterns in chronic spinal cats.

    PubMed

    Pearson, K G; Rossignol, S

    1991-12-01

    1. Fictive motor patterns were recorded in hind leg nerves of 10 adult chronic spinal cats (spinalized at T13). Four of these animals had been trained to step with their hind legs on a treadmill (late-spinal animals), whereas the remainder received no training and were examined a short time after spinalization (early-spinal animals). 2. A fictive pattern resembling the locomotor pattern for stepping was evoked in all animals in response to stimulation of the skin of the perineal region. (2-[2,6-Dichloroaniline]-2-imidazoline) hydrochloride (Clonidine) at doses ranging from 100 to 500 micrograms/kg iv facilitated the production of this pattern, particularly in early-spinal animals. 3. The fictive locomotor pattern in late-spinal animals was more complex than that occurring in early-spinal animals. In the latter the pattern consisted of an alternation of activity in flexor and extensor nerves, and changing leg position did not qualitatively alter the pattern, whereas in late-spinal animals the relative durations of the bursts in different flexors were usually not the same, and the pattern of flexor activity was dependent on leg position. 4. Moving the legs from extension to flexion progressively decreased the duration of flexor bursts, increased the cycle period, and decreased the ease with which the pattern could be evoked in both early- and late-spinal animals. 5. 1-beta-3,4-Dihydroxyphenylalanine (DOPA)/Isonocotinic acid 2-[(2-benzylcarbamoyl)ethyl]hydrazide (Nialamide) treatment following Clonidine in early-spinal animals increased the complexity of flexor burst activity. This, and other observations, indicates that DOPA and Clonidine do not have strictly identical actions on the locomotor pattern generator. 6. Stimulation of the paws in late-spinal animals produced two patterns of activity distinctly different from the locomotor pattern. of activity distinctly different from the locomotor pattern. One was a short sequence of high-frequency rhythmic activity (at

  13. Algorithms for adaptive nonlinear pattern recognition

    NASA Astrophysics Data System (ADS)

    Schmalz, Mark S.; Ritter, Gerhard X.; Hayden, Eric; Key, Gary

    2011-09-01

    In Bayesian pattern recognition research, static classifiers have featured prominently in the literature. A static classifier is essentially based on a static model of input statistics, thereby assuming input ergodicity that is not realistic in practice. Classical Bayesian approaches attempt to circumvent the limitations of static classifiers, which can include brittleness and narrow coverage, by training extensively on a data set that is assumed to cover more than the subtense of expected input. Such assumptions are not realistic for more complex pattern classification tasks, for example, object detection using pattern classification applied to the output of computer vision filters. In contrast, we have developed a two step process, that can render the majority of static classifiers adaptive, such that the tracking of input nonergodicities is supported. Firstly, we developed operations that dynamically insert (or resp. delete) training patterns into (resp. from) the classifier's pattern database, without requiring that the classifier's internal representation of its training database be completely recomputed. Secondly, we developed and applied a pattern replacement algorithm that uses the aforementioned pattern insertion/deletion operations. This algorithm is designed to optimize the pattern database for a given set of performance measures, thereby supporting closed-loop, performance-directed optimization. This paper presents theory and algorithmic approaches for the efficient computation of adaptive linear and nonlinear pattern recognition operators that use our pattern insertion/deletion technology - in particular, tabular nearest-neighbor encoding (TNE) and lattice associative memories (LAMs). Of particular interest is the classification of nonergodic datastreams that have noise corruption with time-varying statistics. The TNE and LAM based classifiers discussed herein have been successfully applied to the computation of object classification in hyperspectral

  14. Practical DTCO through design/patterning exploration

    NASA Astrophysics Data System (ADS)

    Lafferty, Neal; Meiring, Jason; Bahnas, Mohamed; O'Neill, Joseph; Endo, Toshikazu; Schumacher, Dan; Culp, James; Wawrzynski, Glenn; Lamba, Gurpreet S.; Adam, Kostas; Sturtevant, John; McGinty, Chris

    2015-03-01

    Design Technology Co-Optimization (DTCO) becomes more important with every new technology node. Complex patterning issues can no longer wait to be detected experimentally using test sites because of compressed technology development schedules. Simulation must be used to discover complex interactions between an iteration of the design rules, and a simultaneous iteration of an intended patterning technology. The problem is often further complicated by an incomplete definition of the patterning space. The DTCO process must be efficient and thoroughly interrogate the legal design space for a technology to be successful. In this paper we present our view of DTCO, called Design and Patterning Exploration. Three emphasis areas are identified and explained with examples: Technology Definition, Technology Learning, and Technology Refinement. The Design and Patterning Exploration flows are applied to a logic 1.3x metal routing layer. Using these flows, yield limiting patterns are identified faster using random layout generation, and can be ruled out or tracked using a database of problem patterns. At the same time, a pattern no longer in the set of rules should not be considered during OPC tuning. The OPC recipe may then be adjusted for better performance on the legal set of pattern constructs. The entire system is dynamic, and users must be able to access related teams output for faster more accurate understanding of design and patterning interactions. In the discussed example, the design rules and OPC recipe are tuned at the same time, leading to faster design rule revisions, as well as improved patterning through more customized OPC and RET.

  15. Superlattice nanowire pattern transfer (SNAP).

    PubMed

    Heath, James R

    2008-12-01

    During the past 15 years or so, nanowires (NWs) have emerged as a new and distinct class of materials. Their novel structural and physical properties separate them from wires that can be prepared using the standard methods for manufacturing electronics. NW-based applications that range from traditional electronic devices (logic and memory) to novel biomolecular and chemical sensors, thermoelectric materials, and optoelectronic devices, all have appeared during the past few years. From a fundamental perspective, NWs provide a route toward the investigation of new physics in confined dimensions. Perhaps the most familiar fabrication method is the vapor-liquid-solid (VLS) growth technique, which produces semiconductor nanowires as bulk materials. However, other fabrication methods exist and have their own advantages. In this Account, I review a particular class of NWs produced by an alternative method called superlattice nanowire pattern transfer (SNAP). The SNAP method is distinct from other nanowire preparation methods in several ways. It can produce large NW arrays from virtually any thin-film material, including metals, insulators, and semiconductors. The dimensions of the NWs can be controlled with near-atomic precision, and NW widths and spacings can be as small as a few nanometers. In addition, SNAP is almost fully compatible with more traditional methods for manufacturing electronics. The motivation behind the development of SNAP was to have a general nanofabrication method for preparing electronics-grade circuitry, but one that would operate at macromolecular dimensions and with access to a broad materials set. Thus, electronics applications, including novel demultiplexing architectures; large-scale, ultrahigh-density memory circuits; and complementary symmetry nanowire logic circuits, have served as drivers for developing various aspects of the SNAP method. Some of that work is reviewed here. As the SNAP method has evolved into a robust nanofabrication

  16. Superlattice nanowire pattern transfer (SNAP).

    PubMed

    Heath, James R

    2008-12-01

    During the past 15 years or so, nanowires (NWs) have emerged as a new and distinct class of materials. Their novel structural and physical properties separate them from wires that can be prepared using the standard methods for manufacturing electronics. NW-based applications that range from traditional electronic devices (logic and memory) to novel biomolecular and chemical sensors, thermoelectric materials, and optoelectronic devices, all have appeared during the past few years. From a fundamental perspective, NWs provide a route toward the investigation of new physics in confined dimensions. Perhaps the most familiar fabrication method is the vapor-liquid-solid (VLS) growth technique, which produces semiconductor nanowires as bulk materials. However, other fabrication methods exist and have their own advantages. In this Account, I review a particular class of NWs produced by an alternative method called superlattice nanowire pattern transfer (SNAP). The SNAP method is distinct from other nanowire preparation methods in several ways. It can produce large NW arrays from virtually any thin-film material, including metals, insulators, and semiconductors. The dimensions of the NWs can be controlled with near-atomic precision, and NW widths and spacings can be as small as a few nanometers. In addition, SNAP is almost fully compatible with more traditional methods for manufacturing electronics. The motivation behind the development of SNAP was to have a general nanofabrication method for preparing electronics-grade circuitry, but one that would operate at macromolecular dimensions and with access to a broad materials set. Thus, electronics applications, including novel demultiplexing architectures; large-scale, ultrahigh-density memory circuits; and complementary symmetry nanowire logic circuits, have served as drivers for developing various aspects of the SNAP method. Some of that work is reviewed here. As the SNAP method has evolved into a robust nanofabrication

  17. Pattern formation in evaporating drops

    NASA Astrophysics Data System (ADS)

    Li, Fang-I.

    The redistribution of organic solutes during drop evaporation is a nanoscale self assembly process with relevance to technologies ranging from inkjet printing of organic displays to synthesis of bio-smart interfaces for sensing and screening. Atomic force microscopy studies comparing the behavior of different generation dendrimers with different surface chemistry in two solvent alcohols on mica substrates confirm that the detailed morphologies of condensed dendrimer ring structures resulting from micro-droplet evaporation sensitively depend on the surface chemistry, the solute evaporation rate and the dendrimer generation. For the dilute concentration studied here the presence of periodically 'scalloped' molecular rings is ubiquitous. The instability wavelength of the scalloped rings is found to be proportional to the width of the ring, similar to observations of the rim instability in dewetting holes. The effect of the surface chemistry of the dendrimer molecules is obvious in the detailed structure of the self assembled rings. Varying the chain length of solvent alcohol leads to modification of ring patterns. The influence of dendrimer generation on ring structure primarily reflects the increase in dendrimer density with generation number. The evolution of G2-50%C12 -pentanol rings as a function of dendrimer concentration is also described. High surface mobility and phase transformation phenomena in condensed, micro-scale dendrimer structures are documented, again using atomic force microscopy. Stratified dendrimer rings undergo dramatic temperature, time and dendrimer generation dependent morphological changes associated with large-scale molecular rearrangements and partial melting. These transformations produce ring structures consisting of a highly stable first monolayer of the scalloped structure in equilibrium with spherical cap shaped dendrimer islands that form at the center of each pre-existing scallop (creating a 'pearl necklace' structure). Analysis of

  18. Global Patterns of Drought Recovery

    NASA Astrophysics Data System (ADS)

    Schwalm, C.; Anderegg, W.; Biondi, F.; Koch, G. W.; Litvak, M. E.; Shaw, J.; Wolf, A.; Huntzinger, D. N.; Michalak, A. M.; Schaefer, K. M.; Fisher, J. B.; Cook, R. B.; Wei, Y.; Fang, Y.; Hayes, D. J.; Huang, M.; Jain, A. K.; Tian, H.

    2015-12-01

    Understanding the impacts of drought on carbon metabolism is crucial to elucidate how global environmental change will alter the climate regulation ecosystem service provided by terrestrial vegetation. Notwithstanding past and anticipated future changes in drought regime the interplay between hydrologic (amelioration of precipitation deficit) and functional (return to pre-drought levels of carbon metabolism) post-drought recovery is not well understood. Recovery time is however a prime determinant of whether ecosystems revert to their initial state or transition to a new equilibrium. Here we quantify post-drought recovery time of gross primary productivity (GPP) at grid cell (0.5° spatial resolution) to global scales using three reconstructions: MODIS, upscaled FLUXNET, and an ensemble of state-of-the-art standardized land surface model runs taken from MsTMIP (Multi-scale Synthesis and Terrestrial Model Intercomparison Project). Drought is tracked using the multiscalar Standardized Precipitation-Evapotranspiration Index drought metric where the integration period (the retrospective window used to calculate the metric) is varied from 1 to 24-months. We define recovery time as a function of both hydrologic and GPP recovery, i.e., both must attain pre-drought levels for recovery to occur. Despite the diverse provenance of the reconstructions, different reconstruction periods, and variable integration lengths several consistent patterns emerge across the c. 4 000 000 drought events and subsequent recovery times cataloged. Recovery time scales with drought severity and drought length. Biological productivity and biodiversity exhibit response surfaces with large amplitudes and clear thresholds whereas soil fertility is a weak constraint. In general, GPP-based descriptors of drought events serve as key boundary conditions for drought recovery. The longest recovery times occur on marginal lands--non-forested, mixed tree-grass, and boreal systems--with a slight uptick for

  19. In vivo responses of cutaneous C-mechanosensitive neurons in mouse to punctate chemical stimuli that elicit itch and nociceptive sensations in humans.

    PubMed

    Ma, C; Nie, H; Gu, Q; Sikand, P; Lamotte, R H

    2012-01-01

    Native cowhage spicules, and heat-inactivated spicules containing histamine or capsaicin, evoke similar sensations of itch and nociceptive sensations in humans. In ongoing studies of the peripheral neural mechanisms of chemical itch and pain in the mouse, extracellular electrophysiological recordings were obtained, in vivo, from the cell bodies of mechanosensitive nociceptive neurons in response to spicule stimuli delivered to their cutaneous receptive fields (RFs) on the distal hindlimb. A total of 43 mechanosensitive, cutaneous, nociceptive neurons with axonal conduction velocities in the C-fiber range (C-nociceptors) were classified as CM if responsive to noxious mechanical stimuli, such as pinch, or CMH if responsive to noxious mechanical and heat stimuli (51°C, 5 s). The tips of native cowhage spicules, or heat-inactivated spicules containing histamine or capsaicin, were applied to the RF. Heat-inactivated spicules containing no chemical produced only a transient response occurring during insertion. Of the 43 mechanosensitive nociceptors recorded, 20 of the 25 CMHs responded to capsaicin, and of these, 13 also responded to cowhage and/or histamine. In contrast, none of the 18 CMs responded to any of the chemical stimuli. The time course of the mean discharge rate of CMHs was similar in response to each type of spicule and generally similar, although reaching a peak earlier, to the temporal profiles of itch and nociceptive sensations evoked by the same stimuli in humans. These findings are consistent with the hypothesis that the itch and nociceptive sensations evoked by these punctuate chemical stimuli are mediated at least in part by the activity of mechanoheat-sensitive C-nociceptors. In contrast, activity in mechanosensitive C-nociceptors that do not respond to heat or to pruritic chemicals is hypothesized as contributing to pain but not to itch. PMID:21994268

  20. Family Patterns Associated with Anorexia Nervosa.

    ERIC Educational Resources Information Center

    Grigg, Darryl N.; And Others

    1989-01-01

    Used family systems perspective to explore familial transactional patterns related to anorexia nervosa among 22 families with an anorexic child and 22 matched control families. Identified 7 family groups with unique family dynamics differentiating one from another. With no single family pattern characterizing families of anorexics, results…

  1. Turn Allocation Patterns and Learning Opportunities

    ERIC Educational Resources Information Center

    Xie, Xiaoyan

    2011-01-01

    Drawing on data from three English classrooms at two Chinese universities, this paper documents the turn-taking patterns that the teachers and students developed over time and explores how these patterns affected students' opportunities to participate in classroom discourse. The data were collected through observations, audio- and video-taping,…

  2. Pattern-fluid interpretation of chemical turbulence

    NASA Astrophysics Data System (ADS)

    Scholz, Christian; Schröder-Turk, Gerd E.; Mecke, Klaus

    2015-04-01

    The spontaneous formation of heterogeneous patterns is a hallmark of many nonlinear systems, from biological tissue to evolutionary population dynamics. The standard model for pattern formation in general, and for Turing patterns in chemical reaction-diffusion systems in particular, are deterministic nonlinear partial differential equations where an unstable homogeneous solution gives way to a stable heterogeneous pattern. However, these models fail to fully explain the experimental observation of turbulent patterns with spatio-temporal disorder in chemical systems. Here we introduce a pattern-fluid model as a general concept where turbulence is interpreted as a weakly interacting ensemble obtained by random superposition of stationary solutions to the underlying reaction-diffusion system. The transition from turbulent to stationary patterns is then interpreted as a condensation phenomenon, where the nonlinearity forces one single mode to dominate the ensemble. This model leads to better reproduction of the experimental concentration profiles for the "stationary phases" and reproduces the turbulent chemical patterns observed by Q. Ouyang and H. L. Swinney [Chaos 1, 411 (1991), 10.1063/1.165851].

  3. Is Patterning Helpful in Children's Education?

    ERIC Educational Resources Information Center

    Kidd, Julie K.; Gadzichowski, K. Marinka; Gallington, Debbie A.; Boyer, Caroline E.; Pasnak, Robert

    2012-01-01

    The authors' purpose was to study the efficacy of patterning instruction in improving the reading and mathematics proficiency of first grade children. Patterning instruction was compared to equal time and effort spent on instruction on reading or mathematics or social studies, which are control conditions in this experiment. The question for…

  4. Automatic optometer operates with infrared test pattern

    NASA Technical Reports Server (NTRS)

    Cornsweet, T. N.; Crane, H. D.

    1970-01-01

    Refractive strength of human eye is monitored by optometer that automatically and continuously images infrared test pattern onto the retina. Condition of focus of the eye at any instant is determined from optometer settings needed to maintain focus of the pattern on the retina.

  5. Discovering Semantic Patterns in Bibliographically Coupled Documents.

    ERIC Educational Resources Information Center

    Qin, Jian

    1999-01-01

    An example of semantic pattern analysis, based on keywords selected from documents grouped by bibliographical coupling, is used to demonstrate the methodological aspects of knowledge discovery in bibliographic databases. Frequency distribution patterns suggest the existence of a common intellectual base with a wide range of specialties and…

  6. Shifting the patterns of nurses' work.

    PubMed

    Buchan, J

    Although most nurses tend to work a three shift pattern of 'earlies', 'lates' and 'nights', increasing interest is being shown in the use of 12-hour shift patterns. James Buchan outlines the advantages and disadvantages of this type of work for both patients and nurses.

  7. THE STRUCTURE OF GROSS MOTOR SKILL PATTERNS.

    ERIC Educational Resources Information Center

    SAFRIT, MARGARET J.

    THIS EFFORT INVOLVED AN EXAMINATION OF BASIC, GROSS MOTOR SKILLS IN A VARIETY OF SPORTS ACTIVITIES THROUGH FACTOR ANALYTIC TECHNIQUES. THREE ALTERNATE SETS OF MOVEMENT FACTOR PATTERNS WERE HYPOTHESIZED ON THE BASIS OF A LOGICAL "OPINION" ANALYSIS. PATTERN "A" REPRESENTED AN OBVIOUS "OPINION" CLASSIFICATION OF THE VARIABLE BY EXTREMITIES USED IN…

  8. Patterns of saccular afferent innervation in sciaenids.

    PubMed

    Selckmann, G M; Ramcharitar, J

    2013-09-01

    In this study, saccular afferent arborization patterns in Atlantic croaker Micropogonias undulatus, red drum Sciaenops ocellatus and spot Leiostomus xanthurus were characterized. Leiostomus xanthurus showed the simplest configuration while M. undulatus displayed the most complex. In addition, hair-cell densities at sites sampled along the rostro-caudal axis of the saccular epithelia correlated with the observed patterns of arborization. PMID:23991887

  9. Patterns of Conceptual Change in Evolution.

    ERIC Educational Resources Information Center

    Demastes, Sherry S.; And Others

    1996-01-01

    Investigates the patterns of students' conceptual restructuring within the theoretical framework of biologic evolution. Results indicate that many conceptions in this content are closely interwoven, so that a change in one conception requires a change in many others. Reports four patterns of conceptual change: cascade, wholesale, incremental, and…

  10. PNP: mining of profile navigational patterns

    NASA Astrophysics Data System (ADS)

    Li, Hua-Fu; Shan, Man-Kwan

    2002-03-01

    Web usage mining is a key knowledge discovery research and as such has been well researched. So far, this research has focused mainly on databases containing access log data only. However, many real-world databases contain users profile data and current solutions for this situation are still insufficient. In this paper we have a large database containing of user profile information together with user web-pages navigation patterns. The user profile data includes quantitative attributes, such as salary or age, and categorical attributes, such as sex or marital status. We introduce the concept of profile navigation patterns, which discusses the problem of relating user profile information to navigational behavior. An example of such profile navigation pattern might be 20% of married people between age 25 and 30 have the similar navigational behavior <(a,c)(c,h)(h,i)(i,h)(h,l)>, where a, c, h, i, l are web pages in a web site. The navigation patterns may contain the generic traversal behavior, e.g. trend to backward moves, cycles etc. The objective of mining profile navigation patterns is to identify browser profile for web personalization. We give an algorithm for mining such profile navigation patterns. Our method (algorithm PNP) can discover profile navigation patterns efficiently. We also present new inclination measurements to identify the interesting profile navigational patterns. Experimental results show the efficiency and scalability of PNP.

  11. Nonlinear pattern formation in Dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Dong, Lifang; Fan, Weili; He, Yafeng; Pattern Formation in DBD Team

    2015-11-01

    Dielectric barrier discharge (DBD) has proven to be a fascinating system for the study of nonlinear pattern formation, which presents an extraordinary variety and richness of patterns with the prominent convenience and practicality of experimental setups. In recent years, by using the special designed DBD system with two water electrodes, we have obtained a rich variety of patterns through nonlinear self-organization of the filaments [Phys. Rev. E 87, 042914 (2013), Phys. Rev. E 85, 066403 (2012), Phys. Rev. E 86, 036211 (2012)]. The spatio-temporal dynamics of these patterns have been studied systematically, and furthermore, the detailed plasma diagnostics have been carried out. These results are of great significance to give deep insight into the nature of nonlinear pattern formation. Based on our previous studies, here we will present the first report on a new complex superlattice pattern, as so called concentric superlattice. It evolves from hexagon pattern and transits to homogenous glow discharge with an increasing of the applied voltage. The spatio-temporal dynamics of the patterns have been investigated by a high speed camera. Results show that the concentric superlattice is an interleaving of three different sub-lattices, which are concentric-ring, concentric-framework, and concentric-dot embedded in the concentric-framework. Based on the experimental measurements, the involved intrinsic physical mechanism will be demonstrated.

  12. Patterns of Giftedness: A Triarchic Analysis.

    ERIC Educational Resources Information Center

    Sternberg, Robert J.

    2000-01-01

    This article presents an analysis of patterns of giftedness based on the triarchic theory of intelligence. The analysis distinguishes among seven different patterns of giftedness and includes: the Analyzer, the Creator, the Practitioner, the Analytical Creator, the Analytical Practitioners, the Creative Practitioner, and the Consummate Balancer.…

  13. Explanation patterns: Understanding mechanically and creatively

    SciTech Connect

    Schank, R.

    1986-01-01

    This book explores an aspect of artificial intelligence. Topics considered include the explanation game, what needs to be explained, explanation goals, the process of explanation: explanation patterns, creativity through the misapplication of explanation patterns, natural language processing (revisited) and some final questions.

  14. 78 FR 5055 - Pattern of Violations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-23

    ... the pattern of violations (POV) provision to provide MSHA with an additional enforcement tool, when other tools had proven ineffective. The final rule implements the statutory and legislative intent that... concerns, the preamble to the final rule addresses: MSHA's Monthly Monitoring Tool for Pattern...

  15. Topological sparse learning of dynamic form patterns.

    PubMed

    Guthier, T; Willert, V; Eggert, J

    2015-01-01

    Motion is a crucial source of information for a variety of tasks in social interactions. The process of how humans recognize complex articulated movements such as gestures or face expressions remains largely unclear. There is an ongoing discussion if and how explicit low-level motion information, such as optical flow, is involved in the recognition process. Motivated by this discussion, we introduce a computational model that classifies the spatial configuration of gradient and optical flow patterns. The patterns are learned with an unsupervised learning algorithm based on translation-invariant nonnegative sparse coding called VNMF that extracts prototypical optical flow patterns shaped, for example, as moving heads or limb parts. A key element of the proposed system is a lateral inhibition term that suppresses activations of competing patterns in the learning process, leading to a low number of dominant and topological sparse activations. We analyze the classification performance of the gradient and optical flow patterns on three real-world human action recognition and one face expression recognition data set. The results indicate that the recognition of human actions can be achieved by gradient patterns alone, but adding optical flow patterns increases the classification performance. The combined patterns outperform other biological-inspired models and are competitive with current computer vision approaches. PMID:25248088

  16. Specific dietary patterns and concentrations of adiponectin

    PubMed Central

    Izadi, Vajihe; Azadbakht, Leila

    2015-01-01

    Background: One of the adipokines mostly secreted from adipose tissue is adiponectin. Adiponectin is well known as the anti-diabetic, anti-obesity and cardio-protective factor. Present study focused on the review the previous studies about relationship between adherence to healthy dietary pattern, independent of one or two special dietary components, and concentration of adiponectin. Materials and Methods: We searched in PubMed search engine from 2003 to July 2014 using the following key words: Healthy dietary pattern, mediterranean dietary pattern, dietary pattern, diet intervention and adiponectin and adipokines. Then, we recruited 10 articles to review in the present study. Results: Cohort studies that are examined this relationship among women showed the strong positive association in this regard. According to cross-sectional studies adherence to healthy dietary pattern like Mediterranian intervention with moderate weight loss had a positive association with concentration of adiponectin. Conclusion: It seems that adherents to the healthy dietary patterns have great levels of circulating adiponectin. However, it is not clear that whether the separate components of healthy dietary patterns like good sources of fats or protein or fibers mostly have important roles in these beneficial effects of such dietary patterns or not. PMID:25983773

  17. International Business Research: Coauthorship Patterns and Quality

    ERIC Educational Resources Information Center

    Chan, Kam C; Fung, Hung-Gay; Leung, Wai K.

    2008-01-01

    The authors investigate published international business research in four international business journals over a 10-year period, 1995-2004: (a) patterns of coauthorship across regions, and (b) the relation between coauthorship patterns and the quality of international business (IB) articles. A cross-region coauthorship enhances the quality of an…

  18. Graphical Representations of Electronic Search Patterns.

    ERIC Educational Resources Information Center

    Lin, Xia; And Others

    1991-01-01

    Discussion of search behavior in electronic environments focuses on the development of GRIP (Graphic Representor of Interaction Patterns), a graphing tool based on HyperCard that produces graphic representations of search patterns. Search state spaces are explained, and forms of data available from electronic searches are described. (34…

  19. Event Structure and Grammatical Patterns: Resultative Constructions

    ERIC Educational Resources Information Center

    Lee, Leslie

    2013-01-01

    This thesis investigates the nature of grammatical patterns through an in-depth study of resultative constructions in Mandarin and Thai. At the heart of the thesis lies the proposal that event structure templates--complex, meaning-based grammatical patterns--must be recognised as primary objects of linguistic analysis. As content-theoretic objects…

  20. Patterns for Designing Children's Centers. A Report.

    ERIC Educational Resources Information Center

    Osmon, Fred Linn

    This book summarizes the issues involved in the design of a children's center. A children's center is defined as an away from home, group child care program for 2-4 year olds. The material is organized into 35 chapters or "patterns." A pattern is a package of design requirements whose solution is focused on a distinct part of the physical…

  1. Number Sense Made Simple Using Number Patterns

    ERIC Educational Resources Information Center

    Su, Hui Fang Huang; Marinas, Carol; Furner, Joseph

    2011-01-01

    This article highlights investigating intriguing number patterns utilising an emerging technology called the Square Tool. Mathematics teachers of grades K-12 will find the Square Tool useful in making connections and bridging the gap from the concrete to the abstract. Pattern recognition helps students discover various mathematical concepts. With…

  2. 78 FR 11902 - Pattern of Violations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ... published in the Federal Register on January 23, 2013 (78 FR 5055). The final rule revised the Agency's... Safety and Health Administration RIN 1219-AB73 Pattern of Violations AGENCY: Mine Safety and Health... requirements contained in the final rule on Pattern of Violations. DATES: The Office of Management and...

  3. Essential Use Cases for Pedagogical Patterns

    ERIC Educational Resources Information Center

    Derntl, Michael; Botturi, Luca

    2006-01-01

    Coming from architecture, through computer science, pattern-based design spread into other disciplines and is nowadays recognized as a powerful way of capturing and reusing effective design practice. However, current pedagogical pattern approaches lack widespread adoption, both by users and authors, and are still limited to individual initiatives.…

  4. Does Science Also Prefer a Ternary Pattern?

    ERIC Educational Resources Information Center

    Pogliani, L.; Klein, D. J.; Balaban, A. T.

    2006-01-01

    Through the importance of the number three in our culture and the strange preference for a ternary pattern of our nature one can perceive how and why number theory degraded to numerology. The strong preference of our minds for simple patterns can be read as the key to understanding not only the development of numerology, but also why scientists…

  5. Sonographic patterns of ribs with tumor involvement.

    PubMed

    Yang, G G; Wu, H D; Yang, P C; Kuo, S H; Luh, K T

    1991-02-01

    We analyzed the sonographic appearance of the ribs when there was tumor involvement in 16 patients (12 men and 4 women). The tumors included 11 carcinomas, 3 nonepithelial malignancies and 2 benign tumors. Three sonographic patterns on the cross section of abnormal ribs were identified. Pattern I was an eccentrical hyperechoic plate-like shadow inside a hypoechoic tumor. Pattern II was a round hyperechoic shadow or ring in the center of a hypoechoic tumor. Pattern III was a hypoechoic tumor only. The Pancoast tumor manifested pattern I. Metastatic cancer, mostly squamous cell carcinoma, manifested pattern II, and both malignant and benign tumors could manifest pattern III. In sonography, the margin and shape of the tumors, the change in the acoustic shadow of the rib and the pleural line did not differentiate the malignant tumors from benign tumors. When we routinely took a biopsy of these tumors under sonar guidance, the diagnostic yield was 100% without any complications. We conclude that the rib should be evaluated in chest sonography, and that pattern recognition and biopsy under sonar guidance are most useful.

  6. A system for learning statistical motion patterns.

    PubMed

    Hu, Weiming; Xiao, Xuejuan; Fu, Zhouyu; Xie, Dan; Tan, Tieniu; Maybank, Steve

    2006-09-01

    Analysis of motion patterns is an effective approach for anomaly detection and behavior prediction. Current approaches for the analysis of motion patterns depend on known scenes, where objects move in predefined ways. It is highly desirable to automatically construct object motion patterns which reflect the knowledge of the scene. In this paper, we present a system for automatically learning motion patterns for anomaly detection and behavior prediction based on a proposed algorithm for robustly tracking multiple objects. In the tracking algorithm, foreground pixels are clustered using a fast accurate fuzzy K-means algorithm. Growing and prediction of the cluster centroids of foreground pixels ensure that each cluster centroid is associated with a moving object in the scene. In the algorithm for learning motion patterns, trajectories are clustered hierarchically using spatial and temporal information and then each motion pattern is represented with a chain of Gaussian distributions. Based on the learned statistical motion patterns, statistical methods are used to detect anomalies and predict behaviors. Our system is tested using image sequences acquired, respectively, from a crowded real traffic scene and a model traffic scene. Experimental results show the robustness of the tracking algorithm, the efficiency of the algorithm for learning motion patterns, and the encouraging performance of algorithms for anomaly detection and behavior prediction. PMID:16929731

  7. 30 CFR 104.3 - Pattern criteria.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... recurrence of violations of mandatory safety standards or health standards which significantly and substantially contribute to the cause and effect of mine safety or health hazards. These criteria are— (1) A... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR PATTERN OF VIOLATIONS PATTERN...

  8. Resurgence of Temporal Patterns of Responding

    ERIC Educational Resources Information Center

    Cancado, Carlos R. X.; Lattal, Kennon A.

    2011-01-01

    The resurgence of temporal patterns of key pecking by pigeons was investigated in two experiments. In Experiment 1, positively accelerated and linear patterns of responding were established on one key under a discrete-trial multiple fixed-interval variable-interval schedule. Subsequently, only responses on a second key produced reinforcers…

  9. 18 CFR 701.5 - Organization pattern.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Organization pattern. 701.5 Section 701.5 Conservation of Power and Water Resources WATER RESOURCES COUNCIL COUNCIL ORGANIZATION Introduction § 701.5 Organization pattern. (a) The Office of the Water Resources Council...

  10. 18 CFR 701.5 - Organization pattern.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Organization pattern. 701.5 Section 701.5 Conservation of Power and Water Resources WATER RESOURCES COUNCIL COUNCIL ORGANIZATION Introduction § 701.5 Organization pattern. (a) The Office of the Water Resources Council...

  11. 18 CFR 701.5 - Organization pattern.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Organization pattern. 701.5 Section 701.5 Conservation of Power and Water Resources WATER RESOURCES COUNCIL COUNCIL ORGANIZATION Introduction § 701.5 Organization pattern. (a) The Office of the Water Resources Council...

  12. 18 CFR 701.5 - Organization pattern.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Organization pattern. 701.5 Section 701.5 Conservation of Power and Water Resources WATER RESOURCES COUNCIL COUNCIL ORGANIZATION Introduction § 701.5 Organization pattern. (a) The Office of the Water Resources Council...

  13. 18 CFR 701.5 - Organization pattern.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Organization pattern. 701.5 Section 701.5 Conservation of Power and Water Resources WATER RESOURCES COUNCIL COUNCIL ORGANIZATION Introduction § 701.5 Organization pattern. (a) The Office of the Water Resources Council...

  14. Speech Patterns and Racial Wage Inequality

    ERIC Educational Resources Information Center

    Grogger, Jeffrey

    2011-01-01

    Speech patterns differ substantially between whites and many African Americans. I collect and analyze speech data to understand the role that speech may play in explaining racial wage differences. Among blacks, speech patterns are highly correlated with measures of skill such as schooling and AFQT scores. They are also highly correlated with the…

  15. Herpes in Dyadic Relationships: Patterns and Treatment.

    ERIC Educational Resources Information Center

    Drob, Sanford; Bernard, Harold S.

    1985-01-01

    Explores how dyadic relationships can be affected when one partner suffers from genital herpes. Six patterns are described: When One Partner Does Not Know, The Compromise Relationship, The Enraged Partner, The Mark of Guilt, Problems in Risk Management, and Herpes Used as Weapon. Treatment strategies for dealing with patterns are offered.…

  16. Online Search Patterns: NLM CATLINE Database.

    ERIC Educational Resources Information Center

    Tolle, John E.; Hah, Sehchang

    1985-01-01

    Presents analysis of online search patterns within user searching sessions of National Library of Medicine ELHILL system and examines user search patterns on the CATLINE database. Data previously analyzed on MEDLINE database for same period is used to compare the performance parameters of different databases within the same information system.…

  17. Visual pattern recognition based on spatio-temporal patterns of retinal ganglion cells’ activities

    PubMed Central

    Jing, Wei; Liu, Wen-Zhong; Gong, Xin-Wei; Gong, Hai-Qing

    2010-01-01

    Neural information is processed based on integrated activities of relevant neurons. Concerted population activity is one of the important ways for retinal ganglion cells to efficiently organize and process visual information. In the present study, the spike activities of bullfrog retinal ganglion cells in response to three different visual patterns (checker-board, vertical gratings and horizontal gratings) were recorded using multi-electrode arrays. A measurement of subsequence distribution discrepancy (MSDD) was applied to identify the spatio-temporal patterns of retinal ganglion cells’ activities in response to different stimulation patterns. The results show that the population activity patterns were different in response to different stimulation patterns, such difference in activity pattern was consistently detectable even when visual adaptation occurred during repeated experimental trials. Therefore, the stimulus pattern can be reliably discriminated according to the spatio-temporal pattern of the neuronal activities calculated using the MSDD algorithm. PMID:21886670

  18. Maternal Dietary Patterns and Pregnancy Outcome

    PubMed Central

    Chen, Xuyang; Zhao, Diqi; Mao, Xun; Xia, Yinyin; Baker, Philip N.; Zhang, Hua

    2016-01-01

    Maternal nutritional status during pregnancy will affect the outcomes for the mother and the baby. Many analyses of the relationship between diet and outcome are often based on a single or a few food items or nutrients. However, foods are not consumed in isolation and dietary patterns can be used to assess the whole diet consumed. The use of dietary pattern analysis to understand nutritional intake and pregnancy outcome is becoming more and more popular. Many published studies have showed the association between maternal dietary patterns and pregnancy outcome. This review examined articles about the relationship between maternal dietary patterns and pregnancy outcome. As a modifiable factor, dietary patterns may be more applicable to clinical and pregnant health interventions. PMID:27338455

  19. Signatures of chaos in animal search patterns

    PubMed Central

    Reynolds, Andy M; Bartumeus, Frederic; Kölzsch, Andrea; van de Koppel, Johan

    2016-01-01

    One key objective of the emerging discipline of movement ecology is to link animal movement patterns to underlying biological processes, including those operating at the neurobiological level. Nonetheless, little is known about the physiological basis of animal movement patterns, and the underlying search behaviour. Here we demonstrate the hallmarks of chaotic dynamics in the movement patterns of mud snails (Hydrobia ulvae) moving in controlled experimental conditions, observed in the temporal dynamics of turning behaviour. Chaotic temporal dynamics are known to occur in pacemaker neurons in molluscs, but there have been no studies reporting on whether chaotic properties are manifest in the movement patterns of molluscs. Our results suggest that complex search patterns, like the Lévy walks made by mud snails, can have their mechanistic origins in chaotic neuronal processes. This possibility calls for new research on the coupling between neurobiology and motor properties. PMID:27019951

  20. Modeling the radiation pattern of LEDs.

    PubMed

    Moreno, Ivan; Sun, Ching-Cherng

    2008-02-01

    Light-emitting diodes (LEDs) come in many varieties and with a wide range of radiation patterns. We propose a general, simple but accurate analytic representation for the radiation pattern of the light emitted from an LED. To accurately render both the angular intensity distribution and the irradiance spatial pattern, a simple phenomenological model takes into account the emitting surfaces (chip, chip array, or phosphor surface), and the light redirected by both the reflecting cup and the encapsulating lens. Mathematically, the pattern is described as the sum of a maximum of two or three Gaussian or cosine-power functions. The resulting equation is widely applicable for any kind of LED of practical interest. We accurately model a wide variety of radiation patterns from several world-class manufacturers.

  1. DNA pattern recognition using canonical correlation algorithm.

    PubMed

    Sarkar, B K; Chakraborty, Chiranjib

    2015-10-01

    We performed canonical correlation analysis as an unsupervised statistical tool to describe related views of the same semantic object for identifying patterns. A pattern recognition technique based on canonical correlation analysis (CCA) was proposed for finding required genetic code in the DNA sequence. Two related but different objects were considered: one was a particular pattern, and other was test DNA sequence. CCA found correlations between two observations of the same semantic pattern and test sequence. It is concluded that the relationship possesses maximum value in the position where the pattern exists. As a case study, the potential of CCA was demonstrated on the sequence found from HIV-1 preferred integration sites. The subsequences on the left and right flanking from the integration site were considered as the two views, and statistically significant relationships were established between these two views to elucidate the viral preference as an important factor for the correlation. PMID:26564973

  2. Skin diseases following a Christmas tree pattern.

    PubMed

    Wollenberg, Andreas; Eames, Tatiana

    2011-01-01

    Pattern analysis of skin lesions is an art and a key competence of every dermatologist. Three major line patterns cover the human body-the dermatomes or Head zones, the nevoid lines of Blaschko, and the relaxed skin tension lines, or Langer lines. Head zones represent skin areas innervated from the same sensory neuronal segment or spinal nerve zone. Blaschko lines are borderlines of epidermal aberration caused by genetic mosaicism occurring in the early stages of embryogenesis. Langer lines show the direction of the lowest naturally occurring skin tension, and its thoracodorsal manifestation is the Christmas tree pattern. Here we review clinical aspects of pityriasis rosea, mycosis fungoides, stage 2 syphilis, exanthematic Kaposi sarcoma, exanthematic psoriasis, Leser-Trelat syndrome, and other primary skin diseases with a Christmas tree pattern. Secondary skin diseases, such as herpes zoster or indeterminate cell histiocytosis, may follow this pattern if they are linked to a primary skin disease by the Wolf isotopic response.

  3. Dietary patterns in pregnancy and birth weight

    PubMed Central

    Coelho, Natália de Lima Pereira; Cunha, Diana Barbosa; Esteves, Ana Paula Pereira; Lacerda, Elisa Maria de Aquino; Filha, Mariza Miranda Theme

    2015-01-01

    OBJECTIVE To analyze if dietary patterns during the third gestational trimester are associated with birth weight. METHODS Longitudinal study conducted in the cities of Petropolis and Queimados, Rio de Janeiro (RJ), Southeastern Brazil, between 2007 and 2008. We analyzed data from the first and second follow-up wave of a prospective cohort. Food consumption of 1,298 pregnant women was assessed using a semi-quantitative questionnaire about food frequency. Dietary patterns were obtained by exploratory factor analysis, using the Varimax rotation method. We also applied the multivariate linear regression model to estimate the association between food consumption patterns and birth weight. RESULTS Four patterns of consumption – which explain 36.4% of the variability – were identified and divided as follows: (1) prudent pattern (milk, yogurt, cheese, fruit and fresh-fruit juice, cracker, and chicken/beef/fish/liver), which explained 14.9% of the consumption; (2) traditional pattern, consisting of beans, rice, vegetables, breads, butter/margarine and sugar, which explained 8.8% of the variation in consumption; (3) Western pattern (potato/cassava/yams, macaroni, flour/farofa/grits, pizza/hamburger/deep fried pastries, soft drinks/cool drinks and pork/sausages/egg), which accounts for 6.9% of the variance; and (4) snack pattern (sandwich cookie, salty snacks, chocolate, and chocolate drink mix), which explains 5.7% of the consumption variability. The snack dietary pattern was positively associated with birth weight (β = 56.64; p = 0.04) in pregnant adolescents. CONCLUSIONS For pregnant adolescents, the greater the adherence to snack pattern during pregnancy, the greater the baby’s birth weight. PMID:26398873

  4. Dietary patterns in pregnancy and birth weight.

    PubMed

    Coelho, Natália de Lima Pereira; Cunha, Diana Barbosa; Esteves, Ana Paula Pereira; Lacerda, Elisa Maria de Aquino; Theme Filha, Mariza Miranda

    2015-01-01

    OBJECTIVE To analyze if dietary patterns during the third gestational trimester are associated with birth weight.METHODS Longitudinal study conducted in the cities of Petropolis and Queimados, Rio de Janeiro (RJ), Southeastern Brazil, between 2007 and 2008. We analyzed data from the first and second follow-up wave of a prospective cohort. Food consumption of 1,298 pregnant women was assessed using a semi-quantitative questionnaire about food frequency. Dietary patterns were obtained by exploratory factor analysis, using the Varimax rotation method. We also applied the multivariate linear regression model to estimate the association between food consumption patterns and birth weight.RESULTS Four patterns of consumption - which explain 36.4% of the variability - were identified and divided as follows: (1) prudent pattern (milk, yogurt, cheese, fruit and fresh-fruit juice, cracker, and chicken/beef/fish/liver), which explained 14.9% of the consumption; (2) traditional pattern, consisting of beans, rice, vegetables, breads, butter/margarine and sugar, which explained 8.8% of the variation in consumption; (3) Western pattern (potato/cassava/yams, macaroni, flour/farofa/grits, pizza/hamburger/deep fried pastries, soft drinks/cool drinks and pork/sausages/egg), which accounts for 6.9% of the variance; and (4) snack pattern (sandwich cookie, salty snacks, chocolate, and chocolate drink mix), which explains 5.7% of the consumption variability. The snack dietary pattern was positively associated with birth weight (β = 56.64; p = 0.04) in pregnant adolescents.CONCLUSIONS For pregnant adolescents, the greater the adherence to snack pattern during pregnancy, the greater the baby's birth weight. PMID:26398873

  5. Dietary patterns in pregnancy and birth weight.

    PubMed

    Coelho, Natália de Lima Pereira; Cunha, Diana Barbosa; Esteves, Ana Paula Pereira; Lacerda, Elisa Maria de Aquino; Theme Filha, Mariza Miranda

    2015-01-01

    OBJECTIVE To analyze if dietary patterns during the third gestational trimester are associated with birth weight.METHODS Longitudinal study conducted in the cities of Petropolis and Queimados, Rio de Janeiro (RJ), Southeastern Brazil, between 2007 and 2008. We analyzed data from the first and second follow-up wave of a prospective cohort. Food consumption of 1,298 pregnant women was assessed using a semi-quantitative questionnaire about food frequency. Dietary patterns were obtained by exploratory factor analysis, using the Varimax rotation method. We also applied the multivariate linear regression model to estimate the association between food consumption patterns and birth weight.RESULTS Four patterns of consumption - which explain 36.4% of the variability - were identified and divided as follows: (1) prudent pattern (milk, yogurt, cheese, fruit and fresh-fruit juice, cracker, and chicken/beef/fish/liver), which explained 14.9% of the consumption; (2) traditional pattern, consisting of beans, rice, vegetables, breads, butter/margarine and sugar, which explained 8.8% of the variation in consumption; (3) Western pattern (potato/cassava/yams, macaroni, flour/farofa/grits, pizza/hamburger/deep fried pastries, soft drinks/cool drinks and pork/sausages/egg), which accounts for 6.9% of the variance; and (4) snack pattern (sandwich cookie, salty snacks, chocolate, and chocolate drink mix), which explains 5.7% of the consumption variability. The snack dietary pattern was positively associated with birth weight (β = 56.64; p = 0.04) in pregnant adolescents.CONCLUSIONS For pregnant adolescents, the greater the adherence to snack pattern during pregnancy, the greater the baby's birth weight.

  6. Dietary patterns in India: a systematic review.

    PubMed

    Green, Rosemary; Milner, James; Joy, Edward J M; Agrawal, Sutapa; Dangour, Alan D

    2016-07-01

    Dietary patterns analysis is an emerging area of research. Identifying distinct patterns within a large dietary survey can give a more accurate representation of what people are eating. Furthermore, it allows researchers to analyse relationships between non-communicable diseases (NCD) and complete diets rather than individual food items or nutrients. However, few such studies have been conducted in developing countries including India, where the population has a high burden of diabetes and CVD. We undertook a systematic review of published and grey literature exploring dietary patterns and relationships with diet-related NCD in India. We identified eight studies, including eleven separate models of dietary patterns. Most dietary patterns were vegetarian with a predominance of fruit, vegetables and pulses, as well as cereals; dietary patterns based on high-fat, high-sugar foods and more meat were also identified. There was large variability between regions in dietary patterns, and there was some evidence of change in diets over time, although no evidence of different diets by sex or age was found. Consumers of high-fat dietary patterns were more likely to have greater BMI, and a dietary pattern high in sweets and snacks was associated with greater risk of diabetes compared with a traditional diet high in rice and pulses, but other relationships with NCD risk factors were less clear. This review shows that dietary pattern analyses can be highly valuable in assessing variability in national diets and diet-disease relationships. However, to date, most studies in India are limited by data and methodological shortcomings. PMID:27146890

  7. Blood drop patterns: Formation and applications.

    PubMed

    Chen, Ruoyang; Zhang, Liyuan; Zang, Duyang; Shen, Wei

    2016-05-01

    The drying of a drop of blood or plasma on a solid substrate leads to the formation of interesting and complex patterns. Inter- and intra-cellular and macromolecular interactions in the drying plasma or blood drop are responsible for the final morphologies of the dried patterns. Changes in these cellular and macromolecular components in blood caused by diseases have been suspected to cause changes in the dried drop patterns of plasma and whole blood, which could be used as simple diagnostic tools to identify the health of humans and livestock. However, complex physicochemical driving forces involved in the pattern formation are not fully understood. This review focuses on the scientific development in microscopic observations and pattern interpretation of dried plasma and whole blood samples, as well as the diagnostic applications of pattern analysis. Dried drop patterns of plasma consist of intricate visible cracks in the outer region and fine structures in the central region, which are mainly influenced by the presence and concentration of inorganic salts and proteins during drying. The shrinkage of macromolecular gel and its adhesion to the substrate surface have been thought to be responsible for the formation of the cracks. Dried drop patterns of whole blood have three characteristic zones; their formation as functions of drying time has been reported in the literature. Some research works have applied engineering treatment to the evaporation process of whole blood samples. The sensitivities of the resultant patterns to the relative humidity of the environment, the wettability of the substrates, and the size of the drop have been reported. These research works shed light on the mechanisms of spreading, evaporation, gelation, and crack formation of the blood drops on solid substrates, as well as on the potential applications of dried drop patterns of plasma and whole blood in diagnosis. PMID:26988066

  8. Food patterns and the prevention of depression.

    PubMed

    Martínez-González, Miguel A; Sánchez-Villegas, Almudena

    2016-05-01

    An emerging field of research in nutritional epidemiology is the assessment of several links between nutritional quality and mental health. Specifically, some studies have pointed out that several food patterns could be associated with a reduced risk of depression among adults. This association seems to be consistent across countries, cultures and populations according to several systematic reviews and meta-analyses of observational studies. Some previously described food patterns, specifically the Mediterranean Food Pattern, the Alternative Healthy Eating Index, the Prudent diet or the Provegetarian Food Pattern may be effective to reduce the future risk of depression. Among them, only the Mediterranean Food Pattern has been tested for primary prevention in a large randomised trial, but the inverse association found was not statistically significant. The scientific report of the 2015 Dietary Guidelines for Americans Advisory Committee concluded that current evidence is still limited. Notwithstanding, this field is promising and, according to large and well-conducted observational studies, food patterns potentially associated with reduced risk of depression are those emphasising seafood, vegetables, fruits and nuts. There is a need to assess whether differences in the intake of some micro or macronutrients between these dietary patterns can make a difference in their association with a lower risk of depression. Moreover, the shape of the dose-response curve and the potential existence of a nonlinear threshold effect have not yet been established. PMID:26898781

  9. Competitive STDP-based spike pattern learning.

    PubMed

    Masquelier, Timothée; Guyonneau, Rudy; Thorpe, Simon J

    2009-05-01

    Recently it has been shown that a repeating arbitrary spatiotemporal spike pattern hidden in equally dense distracter spike trains can be robustly detected and learned by a single neuron equipped with spike-timing-dependent plasticity (STDP) (Masquelier, Guyonneau, & Thorpe, 2008). To be precise, the neuron becomes selective to successive coincidences of the pattern. Here we extend this scheme to a more realistic scenario with multiple repeating patterns and multiple STDP neurons "listening" to the incoming spike trains. These "listening" neurons are in competition: as soon as one fires, it strongly inhibits the others through lateral connections (one-winner-take-all mechanism). This tends to prevent the neurons from learning the same (parts of the) repeating patterns, as shown in simulations. Instead, the population self-organizes, trying to cover the different patterns or coding one pattern by the successive firings of several neurons, and a powerful distributed coding scheme emerges. Taken together, these results illustrate how the brain could easily encode and decode information in the spike times, a theory referred to as temporal coding, and how STDP could play a key role by detecting repeating patterns and generating selective response to them. PMID:19718815

  10. Adaptive pattern for autonomous UAV guidance

    NASA Astrophysics Data System (ADS)

    Sung, Chen-Ko; Segor, Florian

    2013-09-01

    The research done at the Fraunhofer IOSB in Karlsruhe within the AMFIS project is focusing on a mobile system to support rescue forces in accidents or disasters. The system consists of a ground control station which has the capability to communicate with a large number of heterogeneous sensors and sensor carriers and provides several open interfaces to allow easy integration of additional sensors into the system. Within this research we focus mainly on UAV such as VTOL (Vertical takeoff and Landing) systems because of their ease of use and their high maneuverability. To increase the positioning capability of the UAV, different onboard processing chains of image exploitation for real time detection of patterns on the ground and the interfacing technology for controlling the UAV from the payload during flight were examined. The earlier proposed static ground pattern was extended by an adaptive component which admits an additional visual communication channel to the aircraft. For this purpose different components were conceived to transfer additive information using changeable patterns on the ground. The adaptive ground pattern and their application suitability had to be tested under external influence. Beside the adaptive ground pattern, the onboard process chains and the adaptations to the demands of changing patterns are introduced in this paper. The tracking of the guiding points, the UAV navigation and the conversion of the guiding point positions from the images to real world co-ordinates in video sequences, as well as use limits and the possibilities of an adaptable pattern are examined.

  11. Antenna system providing a spherical radiation pattern

    NASA Technical Reports Server (NTRS)

    Sickles, II, Louis (Inventor)

    1993-01-01

    An antenna system provides a substantially spherical radiation pattern about a structure located above ground level, by locating the individual radiation pattern of each of a plurality of individual antennae, each positioned to have a radiation pattern covering only a portion of the desired sphere, and then applying all antenna signals, during either transmission or reception time intervals, through space-diversity and/or time-diversity apparatus, to cause the patterns of all of the antennae to combine into the desired substantially-spherical pattern. The antennae may have substantially hemispherical patterns, with each antenna of a pair thereof being directed in a direction generally opposite to the other antenna of that pair. Time domain multiple access (TDMA) operation of a master system station, with transmission in different time slots for different portions of the coverage sphere, and selection of the strongest received signal from among all of the plurality N of signals simultaneously received by the plurality N of antennae, can provide the desired spherical radiation pattern in both the transmission and reception modes of operation.

  12. CD bias control on hole pattern

    NASA Astrophysics Data System (ADS)

    Koike, Kyohei; Hara, Arisa; Natori, Sakurako; Yamauchi, Shohei; Yamato, Masatoshi; Oyama, Kenichi; Yaegashi, Hidetami

    2016-03-01

    Gridded design rules[1] is major process in configuring logic circuit used 193-immersion lithography. In the scaling of grid patterning, we can make 10nm order line and space pattern by using multiple patterning techniques such as self-aligned multiple patterning (SAMP) and litho-etch- litho-etch (LELE)[2][3][5] . On the other hand, Line cut process has some error parameters such as pattern defect, placement error, roughness and X-Y CD bias with the decreasing scale. Especially roughness and X-Y CD bias are paid attention because it cause cut error and pattern defect. In this case, we applied some smoothing process to care hole roughness[4]. Each smoothing process showed different effect on X-Y CD bias. In this paper, we will report the pattern controllability comparison of trench and block + inverse. It include X-Y CD bias, roughness and process usability. Furthermore we will discuss optimum method focused on X-Y CD bias when we use additional process such as smoothing and shrink etching .

  13. Pattern formation by a moving morphogen source

    NASA Astrophysics Data System (ADS)

    Zartman, Jeremiah J.; Cheung, Lily S.; Niepielko, Matthew G.; Bonini, Christine; Haley, Benjamin; Yakoby, Nir; Shvartsman, Stanislav Y.

    2011-08-01

    During Drosophila melanogaster oogenesis, the follicular epithelium that envelops the germline cyst gives rise to an elaborate eggshell, which houses the future embryo and mediates its interaction with the environment. A prominent feature of the eggshell is a pair of dorsal appendages, which are needed for embryo respiration. Morphogenesis of this structure depends on broad, a zinc-finger transcription factor, regulated by the EGFR pathway. While much has been learned about the mechanisms of broad regulation by EGFR, current understanding of processes that shape the spatial pattern of broad expression is incomplete. We propose that this pattern is defined by two different phases of EGFR activation: an early, posterior-to-anterior gradient of EGFR signaling sets the posterior boundary of broad expression, while the anterior boundary is set by a later phase of EGFR signaling, distributed in a dorsoventral gradient. This model can explain the wild-type pattern of broad in D. melanogaster, predicts how this pattern responds to genetic perturbations, and provides insight into the mechanisms driving diversification of eggshell patterning. The proposed model of the broad expression pattern can be used as a starting point for the quantitative analysis of a large number of gene expression patterns in Drosophila oogenesis.

  14. Discriminative Chemical Patterns: Automatic and Interactive Design.

    PubMed

    Bietz, Stefan; Schomburg, Karen T; Hilbig, Matthias; Rarey, Matthias

    2015-08-24

    The classification of molecules with respect to their inhibiting, activating, or toxicological potential constitutes a central aspect in the field of cheminformatics. Often, a discriminative feature is needed to distinguish two different molecule sets. Besides physicochemical properties, substructures and chemical patterns belong to the descriptors most frequently applied for this purpose. As a commonly used example of this descriptor class, SMARTS strings represent a powerful concept for the representation and processing of abstract chemical patterns. While their usage facilitates a convenient way to apply previously derived classification rules on new molecule sets, the manual generation of useful SMARTS patterns remains a complex and time-consuming process. Here, we introduce SMARTSminer, a new algorithm for the automatic derivation of discriminative SMARTS patterns from preclassified molecule sets. Based on a specially adapted subgraph mining algorithm, SMARTSminer identifies structural features that are frequent in only one of the given molecule classes. In comparison to elemental substructures, it also supports the consideration of general and specific SMARTS features. Furthermore, SMARTSminer is integrated into an interactive pattern editor named SMARTSeditor. This allows for an intuitive visualization on the basis of the SMARTSviewer concept as well as interactive adaption and further improvement of the generated patterns. Additionally, a new molecular matching feature provides an immediate feedback on a pattern's matching behavior across the molecule sets. We demonstrate the utility of the SMARTSminer functionality and its integration into the SMARTSeditor software in several different classification scenarios.

  15. Pattern formation by a moving morphogen source

    PubMed Central

    Zartman, Jeremiah J.; Cheung, Lily S.; Niepielko, Matthew; Bonini, Christine; Haley, Benjamin; Yakoby, Nir; Shvartsman, Stanislav Y.

    2013-01-01

    During Drosophila melanogaster oogenesis, the follicular epithelium that envelops the germline cyst gives rise to an elaborate eggshell, which houses the future embryo and mediates its interaction with the environment. A prominent feature of the eggshell is a pair of dorsal appendages, which are needed for embryo respiration. Morphogenesis of this structure depends on Broad, a Zinc-finger transcription factor, regulated by the EGFR pathway. While much has been learned about the mechanisms of Broad regulation by EGFR, current understanding of processes that shape the spatial pattern of Broad expression is incomplete. We propose that this pattern is defined by two different phases of EGFR activation: An early, posterior-to-anterior gradient of EGFR signaling sets the posterior boundary of Broad expression, while the anterior boundary is set by a later phase of EGFR signaling, distributed in a dorsoventral gradient. This model can explain the wild-type pattern of Broad in D. melanogaster, predicts how this pattern responds to genetic perturbations, and provides insight into the mechanisms driving diversification of eggshell patterning. The proposed model of the Broad expression pattern can be used as a starting point for the quantitative analysis of a large number of gene expression patterns in Drosophila oogenesis. PMID:21750363

  16. Turing patterns beyond hexagons and stripes.

    PubMed

    Yang, Lingfa; Dolnik, Milos; Zhabotinsky, Anatol M; Epstein, Irving R

    2006-09-01

    The best known Turing patterns are composed of stripes or simple hexagonal arrangements of spots. Until recently, Turing patterns with other geometries have been observed only rarely. Here we present experimental studies and mathematical modeling of the formation and stability of hexagonal and square Turing superlattice patterns in a photosensitive reaction-diffusion system. The superlattices develop from initial conditions created by illuminating the system through a mask consisting of a simple hexagonal or square lattice with a wavelength close to a multiple of the intrinsic Turing pattern's wavelength. We show that interaction of the photochemical periodic forcing with the Turing instability generates multiple spatial harmonics of the forcing patterns. The harmonics situated within the Turing instability band survive after the illumination is switched off and form superlattices. The square superlattices are the first examples of time-independent square Turing patterns. We also demonstrate that in a system where the Turing band is slightly below criticality, spatially uniform internal or external oscillations can create oscillating square patterns. PMID:17014248

  17. Ultraviolet laser patterning of porous silicon

    SciTech Connect

    Vega, Fidel; Peláez, Ramón J.; Kuhn, Timo; Afonso, Carmen N.; Recio-Sánchez, Gonzalo; Martín-Palma, Raúl J.

    2014-05-14

    This work reports on the fabrication of 1D fringed patterns on nanostructured porous silicon (nanoPS) layers (563, 372, and 290 nm thick). The patterns are fabricated by phase-mask laser interference using single pulses of an UV excimer laser (193 nm, 20 ns pulse duration). The method is a single-step and flexible approach to produce a large variety of patterns formed by alternate regions of almost untransformed nanoPS and regions where its surface has melted and transformed into Si nanoparticles (NPs). The role of laser fluence (5–80 mJ cm{sup −2}), and pattern period (6.3–16 μm) on pattern features and surface structuring are discussed. The results show that the diameter of Si NPs increases with fluence up to a saturation value of 75 nm for a fluence ≈40 mJ cm{sup −2}. In addition, the percentage of transformed to non-transformed region normalized to the pattern period follows similar fluence dependence regardless the period and thus becomes an excellent control parameter. This dependence is fitted within a thermal model that allows for predicting the in-depth profile of the pattern. The model assumes that transformation occurs whenever the laser-induced temperature increase reaches the melting temperature of nanoPS that has been found to be 0.7 of that of crystalline silicon for a porosity of around 79%. The role of thermal gradients across the pattern is discussed in the light of the experimental results and the calculated temperature profiles, and shows that the contribution of lateral thermal flow to melting is not significant for pattern periods ≥6.3 μm.

  18. Nanotribological and wetting performance of hierarchical patterns.

    PubMed

    Grewal, H S; Piao, Shuxue; Cho, Il-Joo; Jhang, Kyung-Young; Yoon, Eui-Sung

    2016-01-21

    Surface modification is a promising method to solve the tribological problems in microsystems. To modify the surface, we fabricated hierarchical patterns with different pitches of nano-scale features and different surface chemistries. Micro- and nano-patterns with similar geometrical configurations were also fabricated for comparison. The nano-tribological behavior of the patterns was investigated using an atomic force microscope at different relative humidity levels (5% to 80%) and applied normal loads (40 nN to 120 nN) under a constant sliding velocity. The results showed significant enhancement in the de-wetting and tribological performance of the hierarchical patterns compared with those of flat and micro- and nano-patterned surfaces. The PTFE-coated hierarchical patterns showed similar dynamic contact angles (advancing and receding) to those of the real lotus leaf. The influence of relative humidity on adhesion and friction behavior was found to be significant for all the tested surfaces. The tribological performance was improved as the pitch of the nano-scale geometry of the hierarchical pattern increased, even though the wetting property was not influenced significantly. A model was proposed based on the role of intermolecular force to explain the effect of the pitch of the hierarchical patterns on the adhesion and friction behavior. According to the model based on the molecular force, the contact between a ball and the patterned surface was a multi-asperity contact, contrary to the single-asperity contact predicted by the Johnson-Kendall-Roberts (JKR) and Maugis-Dugdale (MD) models. The strong intermolecular forces, which are activated in the confined spaces between the adjacent nano-pillars and the ball, contributed to the contact area and hence the adhesion and friction forces.

  19. Nanotribological and wetting performance of hierarchical patterns.

    PubMed

    Grewal, H S; Piao, Shuxue; Cho, Il-Joo; Jhang, Kyung-Young; Yoon, Eui-Sung

    2016-01-21

    Surface modification is a promising method to solve the tribological problems in microsystems. To modify the surface, we fabricated hierarchical patterns with different pitches of nano-scale features and different surface chemistries. Micro- and nano-patterns with similar geometrical configurations were also fabricated for comparison. The nano-tribological behavior of the patterns was investigated using an atomic force microscope at different relative humidity levels (5% to 80%) and applied normal loads (40 nN to 120 nN) under a constant sliding velocity. The results showed significant enhancement in the de-wetting and tribological performance of the hierarchical patterns compared with those of flat and micro- and nano-patterned surfaces. The PTFE-coated hierarchical patterns showed similar dynamic contact angles (advancing and receding) to those of the real lotus leaf. The influence of relative humidity on adhesion and friction behavior was found to be significant for all the tested surfaces. The tribological performance was improved as the pitch of the nano-scale geometry of the hierarchical pattern increased, even though the wetting property was not influenced significantly. A model was proposed based on the role of intermolecular force to explain the effect of the pitch of the hierarchical patterns on the adhesion and friction behavior. According to the model based on the molecular force, the contact between a ball and the patterned surface was a multi-asperity contact, contrary to the single-asperity contact predicted by the Johnson-Kendall-Roberts (JKR) and Maugis-Dugdale (MD) models. The strong intermolecular forces, which are activated in the confined spaces between the adjacent nano-pillars and the ball, contributed to the contact area and hence the adhesion and friction forces. PMID:26549103

  20. Strategies for the reduction of pattern effects

    SciTech Connect

    Kersch, A.; Schafbauer, T.; Deutschmann, L.

    1996-12-01

    The pattern effects in hot processes arise from a spatial variation of the radiative heat flux imbalance between emission and absorption. There are two scenarios to reduce the pattern effect: a very reflective chamber facing the patterned side with an illumination from the backside or a controlled double sided illumination on the other hand. The paper demonstrates the mechanism of both scenarios with a simple mathematical model and discusses the limitations of the approaches. The results will be exemplified with the help of reactor scale simulations involving a detailed Monte Carlo radiation model featuring continuous spectral dependence.

  1. Dynamic pattern matcher using incomplete data

    NASA Technical Reports Server (NTRS)

    Johnson, Gordon G. (Inventor); Wang, Lui (Inventor)

    1993-01-01

    This invention relates generally to pattern matching systems, and more particularly to a method for dynamically adapting the system to enhance the effectiveness of a pattern match. Apparatus and methods for calculating the similarity between patterns are known. There is considerable interest, however, in the storage and retrieval of data, particularly, when the search is called or initiated by incomplete information. For many search algorithms, a query initiating a data search requires exact information, and the data file is searched for an exact match. Inability to find an exact match thus results in a failure of the system or method.

  2. STPMiner: A Highperformance Spatiotemporal Pattern Mining Toolbox

    SciTech Connect

    Vatsavai, Raju

    2011-01-01

    The volume of spatiotemporal data being generated from scientific simulations and observations from sensors is growing at an astronomical rate. This data explosion is going to pose three challenges to the existing data mining infrastructure: algorithmic, computational, and I/O. Over the years we have implemented several spatiotemporal data mining algorithms including: outliers/anomalies, colocation patterns, change patterns, clustering, classification, and prediction algorithms. In this paper we briefly discuss the core spatiotemporal pattern mining algorithms along with some of the computational and I/O challenges associated with the big data.

  3. Fabrication of scrolled magnetic thin film patterns

    NASA Astrophysics Data System (ADS)

    Min, Seonggi; Lim, Jin-Hee; Gaffney, John; Kinttle, Kristofer; Wiley, John B.; Malkinski, Leszek

    2012-04-01

    Magnetic film scrolls have been fabricated via a deterministic release of rectangular patterns of bimetallic Ti (20 nm)/Ni (20 , 30 or 40 nm) films from a sacrificial Cu underlayer. The diameter of the scrolls varied from 2.64 μm to 4.28 μm with increasing thickness of the Ni layer from 20 to 40 nm. This behavior was found to be consistent with the model of bilayered film with interfacial strain between the Ti and Ni layers of about Δɛ = 0.01. Changing the geometry of the patterns from flat patterns to scrolls led to changes in their magnetic properties.

  4. Pattern formation by vascular mesenchymal cells

    NASA Astrophysics Data System (ADS)

    Garfinkel, Alan; Tintut, Yin; Petrasek, Danny; Boström, Kristina; Demer, Linda L.

    2004-06-01

    In embryogenesis, immature mesenchymal cells aggregate and organize into patterned tissues. Later in life, a pathological recapitulation of this process takes place in atherosclerotic lesions, when vascular mesenchymal cells organize into trabecular bone tissue within the artery wall. Here we show that multipotential adult vascular mesenchymal cells self-organize in vitro into patterns that are predicted by a mathematical model based on molecular morphogens interacting in a reaction-diffusion process. We identify activator and inhibitor morphogens for stripe, spot, and labyrinthine patterns and confirm the model predictions in vitro. Thus, reaction-diffusion principles may play a significant role in morphogenetic processes in adult mesenchymal cells.

  5. Global Software Development Patterns for Project Management

    NASA Astrophysics Data System (ADS)

    Välimäki, Antti; Kääriäinen, Jukka; Koskimies, Kai

    Global software development with the agile or waterfall development process has been taken into use in many companies. GSD offers benefits but also new challenges without known, documented solutions. The goal of this research is to present current best practices for GSD in the form of process patterns for project management, evaluated by using a scenario-based assessment method. The best practices have been collected from a large company operating in process automation. It is expected that the resulting pattern language helps other companies to improve their GSD processes by incorporating the patterns in the processes.

  6. Patterning NHS-terminated SAMs on germanium.

    PubMed

    Morris, Carleen J; Shestopalov, Alexander A; Gold, Brian H; Clark, Robert L; Toone, Eric J

    2011-05-17

    Here we report a simple, robust approach to patterning functional SAMs on germanium. The protocol relies on catalytic soft-lithographic pattern transfer from an elastomeric stamp bearing pendant immobilized sulfonic acid moieties to an NHS-functionalized bilayer molecular system comprising a primary ordered alkyl monolayer and a reactive ester secondary overlayer. The catalytic polyurethane-acrylate stamp was used to form micrometer-scale features of chemically distinct SAMs on germanium. The methodology represents the first example of patterned SAMs on germanium, a semiconductor material.

  7. Deciphering skeletal patterning: clues from the limb.

    PubMed

    Mariani, Francesca V; Martin, Gail R

    2003-05-15

    Even young children can distinguish a Tyrannosaurus rex from a Brontosaurus by observing differences in bone size, shape, number and arrangement, that is, skeletal pattern. But despite our extensive knowledge about cartilage and bone formation per se, it is still largely a mystery how skeletal pattern is established. Much of what we do know has been learned from studying limb development in chicken and mouse embryos. Based on the data from such studies, models for how limb skeletal pattern is established have been proposed and continue to be hotly debated.

  8. Photovoltaic cell with nano-patterned substrate

    DOEpatents

    Cruz-Campa, Jose Luis; Zhou, Xiaowang; Zubia, David

    2016-10-18

    A photovoltaic solar cell comprises a nano-patterned substrate layer. A plurality of nano-windows are etched into an intermediate substrate layer to form the nano-patterned substrate layer. The nano-patterned substrate layer is positioned between an n-type semiconductor layer composed of an n-type semiconductor material and a p-type semiconductor layer composed of a p-type semiconductor material. Semiconductor material accumulates in the plurality of nano-windows, causing a plurality of heterojunctions to form between the n-type semiconductor layer and the p-type semiconductor layer.

  9. Pattern recognition monitoring of PEM fuel cell

    DOEpatents

    Meltser, Mark Alexander

    1999-01-01

    The CO-concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H.sub.2 fuel stream.

  10. Coauthorship networks and patterns of scientific collaboration.

    PubMed

    Newman, M E J

    2004-04-01

    By using data from three bibliographic databases in biology, physics, and mathematics, respectively, networks are constructed in which the nodes are scientists, and two scientists are connected if they have coauthored a paper. We use these networks to answer a broad variety of questions about collaboration patterns, such as the numbers of papers authors write, how many people they write them with, what the typical distance between scientists is through the network, and how patterns of collaboration vary between subjects and over time. We also summarize a number of recent results by other authors on coauthorship patterns.

  11. Coauthorship networks and patterns of scientific collaboration

    PubMed Central

    Newman, M. E. J.

    2004-01-01

    By using data from three bibliographic databases in biology, physics, and mathematics, respectively, networks are constructed in which the nodes are scientists, and two scientists are connected if they have coauthored a paper. We use these networks to answer a broad variety of questions about collaboration patterns, such as the numbers of papers authors write, how many people they write them with, what the typical distance between scientists is through the network, and how patterns of collaboration vary between subjects and over time. We also summarize a number of recent results by other authors on coauthorship patterns. PMID:14745042

  12. Spatial patterns of mortality in Bangladesh.

    PubMed

    Sharif, A H; Huq, S M; Mesbah-us-Saleheen

    1993-05-01

    This paper depicts the spatial patterns of mortality of the administrative upazilas of Bangladesh. Due to the absence of adequate data on mortality rates from across the country, the mortality rates of the upazilas are calculated from the age sex structure of the population of the respective upazilas employing the standardized mortality rates of divisional headquarters. Crude death rates are used to determine spatial patterns of mortality in Bangladesh. The patterns portray strong regional differences. Such differentiation is accounted for by traditional differences in demographic and socio-economic factors. Also, regression analysis is used to assist in explaining spatial variations.

  13. Patterns In Debris Disks: No Planets Required?

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2012-01-01

    Debris disks like those around Fomalhaut and Beta Pictoris show striking dust patterns often attributed to hidden exoplanets. These patterns have been crucial for constraining the masses and orbits of these planets. But adding a bit of gas to our models of debris disks--too little gas to detect--seems to alter this interpretation. Small amounts of gas lead to new dynamical instabilities that may mimic the narrow eccentric rings and other structures planets would create in a gas-free disk. Can we still use dust patterns to find hidden exoplanets?

  14. Pattern recognition monitoring of PEM fuel cell

    DOEpatents

    Meltser, M.A.

    1999-08-31

    The CO-concentration in the H{sub 2} feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H{sub 2} fuel stream. 4 figs.

  15. Patterned when wet: environment-dependent multifunctional patterns within amphiphilic colloidal crystals.

    PubMed

    Brozell, Adrian M; Muha, Michelle A; Abed-Amoli, Arian; Bricarello, Daniel; Parikh, Atul N

    2007-12-01

    A simple integration of molecular and colloidal self-assembly approaches with photopatterning is shown to produce multifunctional patterns of amphiphilic colloidal crystals. These crystals display binary spatial patterns of wettability by water and a single photonic stop-band in air. Upon exposure to water, the uniform stop-band is replaced by a pattern of coexisting stop-bands that reflect the underlying pattern of surface wetting. These hydration-dependent photonic patterns within single colloidal crystals form because of near-complete water rejection from the three-dimensionally disposed nanoscale interstices in hydrophobic regions and its exclusive permeation within the hydrophilic regions. This water permeation pattern is further structured by the three-dimensional (3D) distribution and contiguity of the nanoscale interstices between individual colloids, allowing 3D patterned organization of functional units in secondary self-assembly processes, as illustrated using quantum dots, metal nanoparticles, and fluorescent probes.

  16. Patterned Taping: A High-Efficiency Soft Lithographic Method for Universal Thin Film Patterning.

    PubMed

    Oh, Sangyoon; Park, Sang Kyu; Kim, Jin Hong; Cho, Illhun; Kim, Hyeong-Ju; Park, Soo Young

    2016-03-22

    As a universal lithographic technique for microscale/nanoscale film patterns, we develop a strategy for the use of soft lithographically patterned pressure-sensitive tape (patterned tape) as a pattern-transporting stamp material. Patterning was successfully implemented through the selective detachment and/or attachment of various thin films, including organic and metallic layers demanding no subsequent physical, thermal, or chemical treatment, as this incurs the risk of the deformation of the thin film and the deterioration of its functionalities. Its features of universal adhesion and flexibility enable pressure-sensitive tapes to form patterns on a variety of surfaces: organic, polymeric, and inorganic surfaces as well as flat, curved, uneven, and flexible substrates. Moreover, the proposed technique boasts the unique and distinct advantages of short operation time, supreme patterning yield, and multilayer stacking capability, which suggest considerable potential for their application to advanced optoelectronic device fabrication.

  17. Patterned Taping: A High-Efficiency Soft Lithographic Method for Universal Thin Film Patterning.

    PubMed

    Oh, Sangyoon; Park, Sang Kyu; Kim, Jin Hong; Cho, Illhun; Kim, Hyeong-Ju; Park, Soo Young

    2016-03-22

    As a universal lithographic technique for microscale/nanoscale film patterns, we develop a strategy for the use of soft lithographically patterned pressure-sensitive tape (patterned tape) as a pattern-transporting stamp material. Patterning was successfully implemented through the selective detachment and/or attachment of various thin films, including organic and metallic layers demanding no subsequent physical, thermal, or chemical treatment, as this incurs the risk of the deformation of the thin film and the deterioration of its functionalities. Its features of universal adhesion and flexibility enable pressure-sensitive tapes to form patterns on a variety of surfaces: organic, polymeric, and inorganic surfaces as well as flat, curved, uneven, and flexible substrates. Moreover, the proposed technique boasts the unique and distinct advantages of short operation time, supreme patterning yield, and multilayer stacking capability, which suggest considerable potential for their application to advanced optoelectronic device fabrication. PMID:26863506

  18. Using pattern analysis methods to do fast detection of manufacturing pattern failures

    NASA Astrophysics Data System (ADS)

    Zhao, Evan; Wang, Jessie; Sun, Mason; Wang, Jeff; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh; Ding, Hua

    2016-03-01

    At the advanced technology node, logic design has become extremely complex and is getting more challenging as the pattern geometry size decreases. The small sizes of layout patterns are becoming very sensitive to process variations. Meanwhile, the high pressure of yield ramp is always there due to time-to-market competition. The company that achieves patterning maturity earlier than others will have a great advantage and a better chance to realize maximum profit margins. For debugging silicon failures, DFT diagnostics can identify which nets or cells caused the yield loss. But normally, a long time period is needed with many resources to identify which failures are due to one common layout pattern or structure. This paper will present a new yield diagnostic flow, based on preliminary EFA results, to show how pattern analysis can more efficiently detect pattern related systematic defects. Increased visibility on design pattern related failures also allows more precise yield loss estimation.

  19. Adaptive pattern recognition and neural networks

    SciTech Connect

    Pao, Yohhan.

    1989-01-01

    The application of neural-network computers to pattern-recognition tasks is discussed in an introduction for advanced students. Chapters are devoted to the nature of the pattern-recognition task, the Bayesian approach to the estimation of class membership, the fuzzy-set approach, patterns with nonnumeric feature values, learning discriminants and the generalized perceptron, recognition and recall on the basis of partial cues, associative memories, self-organizing nets, the functional-link net, fuzzy logic in the linking of symbolic and subsymbolic processing, and adaptive pattern recognition and its applications. Also included are C-language programs for (1) a generalized delta-rule net for supervised learning and (2) unsupervised learning based on the discovery of clustered structure. 183 refs.

  20. Patterned cholesteric liquid crystal polymer film.

    PubMed

    Hsu, Wei-Liang; Ma, Ji; Myhre, Graham; Balakrishnan, Kaushik; Pau, Stanley

    2013-02-01

    Herein, the ability to create arbitrarily patterned circular polarized optical devices is demonstrated by using cholesteric liquid crystal polymer. Photoalignment with polarized ultraviolet light is utilized to create aligned cholesteric liquid crystal films. Two different methods, thermal annealing and solvent rinse, are utilized for patterning cholesteric liquid crystal films over large areas. The patterned cholesteric liquid crystal films are measured using a Mueller matrix imaging polarimeter, and the polarization properties, including depolarization index, circular diattenuation (CD), and circular retardance are derived. Patterned nonlinearly polarized optical devices can be fabricated with feature sizes as small as 20 μm with a CD of 0.812±0.015. Circular polarizing filters based on polymer cholesteric liquid crystal films have applications in three-dimensional displays, medical imaging, polarimetry, and interferometry. PMID:23456060

  1. Controlling synchronous patterns in complex networks.

    PubMed

    Lin, Weijie; Fan, Huawei; Wang, Ying; Ying, Heping; Wang, Xingang

    2016-04-01

    Although the set of permutation symmetries of a complex network could be very large, few of them give rise to stable synchronous patterns. Here we present a general framework and develop techniques for controlling synchronization patterns in complex network of coupled chaotic oscillators. Specifically, according to the network permutation symmetry, we design a small-size and weighted network, namely the control network, and use it to control the large-size complex network by means of pinning coupling. We argue mathematically that for any of the network symmetries, there always exists a critical pinning strength beyond which the unstable synchronous pattern associated to this symmetry can be stabilized. The feasibility of the control method is verified by numerical simulations of both artificial and real-world networks and demonstrated experimentally in systems of coupled chaotic circuits. Our studies show the controllability of synchronous patterns in complex networks of coupled chaotic oscillators.

  2. Forbidden patterns in financial time series

    NASA Astrophysics Data System (ADS)

    Zanin, Massimiliano

    2008-03-01

    The existence of forbidden patterns, i.e., certain missing sequences in a given time series, is a recently proposed instrument of potential application in the study of time series. Forbidden patterns are related to the permutation entropy, which has the basic properties of classic chaos indicators, such as Lyapunov exponent or Kolmogorov entropy, thus allowing to separate deterministic (usually chaotic) from random series; however, it requires fewer values of the series to be calculated, and it is suitable for using with small datasets. In this paper, the appearance of forbidden patterns is studied in different economical indicators such as stock indices (Dow Jones Industrial Average and Nasdaq Composite), NYSE stocks (IBM and Boeing), and others (ten year Bond interest rate), to find evidence of deterministic behavior in their evolutions. Moreover, the rate of appearance of the forbidden patterns is calculated, and some considerations about the underlying dynamics are suggested.

  3. Career Development and Emerging Managerial Career Patterns.

    ERIC Educational Resources Information Center

    Grzeda, Maurice

    1999-01-01

    Career-motivation theory provides a new framework for managerial careers in the context of contemporary career patterns. The framework includes the concepts of career resilience, career insight, and career identity. (SK)

  4. Harnessing vocal patterns for social communication

    PubMed Central

    Sweeney, Lora B.; Kelley, Darcy B.

    2014-01-01

    Work on vocal communication, influenced by a drive to understand the evolution of language, has focused on auditory processing and forebrain control of learned vocalizations. The actual hindbrain neural mechanisms used to create communication signals are understudied, in part because of the difficulty of experimental studies in species that rely on respiration for vocalization. In these experimental systems – including those that embody vocal learning – vocal behaviors have rhythmic qualities. Recent studies using molecular markers and “fictive” patterns produced by isolated brains are beginning to reveal how hindbrain circuits generate vocal patterns. Insights from central pattern generators for respiration and locomotion are illuminating common neural and developmental mechanisms. Choice of vocal patterns is responsive to socially salient input. Studies of the vertebrate social brain network suggest mechanisms used to integrate socially salient information and produce an appropriate vocal response. PMID:24995669

  5. The compass rose pattern in electricity prices

    NASA Astrophysics Data System (ADS)

    Batten, Jonathan A.; Hamada, Mahmoud

    2009-12-01

    The "compass rose pattern" is known to appear in the phase portraits, or scatter diagrams, of the high-frequency returns of financial series. We first show that this pattern is also present in the returns of spot electricity prices. Early researchers investigating these phenomena hoped that these patterns signaled the presence of rich dynamics, possibly chaotic or fractal in nature. Although there is a definite autoregressive and conditional heteroscedasticity structure in electricity returns, we find that after simple filtering no pattern remains. While the series is non-normal in terms of their distribution and statistical tests fail to identify significant chaos, there is evidence of fractal structures in periodic price returns when measured over the trading day. The phase diagram of the filtered returns provides a useful visual check on independence, a property necessary for pricing and trading derivatives and portfolio construction, as well as providing useful insights into the market dynamics.

  6. Patterns and Symmetry: Reflections of Culture.

    ERIC Educational Resources Information Center

    Moyer, Patricia S.

    2001-01-01

    Describes how students connect culture and mathematics by using tessellating and symmetrical patterns in the designs of architecture, pottery, blankets, and baskets as models to create geometric designs for a quilt. (Author/YDS)

  7. Moving contact line on chemically patterned surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Ping; Qian, Tiezheng; Sheng, Ping

    We simulate the moving contact line in two-dimensional chemically patterned channels using a diffuse-interface model with the generalized Navier boundary condition. The motion of the fluidslip behaviour of the contact line. The extra dissipation induced by this oscillatory contact-line motion is significant and increases rapidly with the wettability contrast of the pattern. A critical value of the wettability contrast is identified above which the effect of diffusion becomes important, leading to the interesting behaviour of fluid-fluid interface breaking, with the transport of the non-wetting fluid being assisted and mediated by rapid diffusion through the wetting fluid. Near the critical value, the time-averaged extra dissipation scales as U, the displacement velocity. By decreasing the period of the pattern, we show the solid surface to be characterized by an effective contact angle whose value depends on the material characteristics and composition of the patterned surfaces.

  8. Universal predictability of mobility patterns in cities.

    PubMed

    Yan, Xiao-Yong; Zhao, Chen; Fan, Ying; Di, Zengru; Wang, Wen-Xu

    2014-11-01

    Despite the long history of modelling human mobility, we continue to lack a highly accurate approach with low data requirements for predicting mobility patterns in cities. Here, we present a population-weighted opportunities model without any adjustable parameters to capture the underlying driving force accounting for human mobility patterns at the city scale. We use various mobility data collected from a number of cities with different characteristics to demonstrate the predictive power of our model. We find that insofar as the spatial distribution of population is available, our model offers universal prediction of mobility patterns in good agreement with real observations, including distance distribution, destination travel constraints and flux. By contrast, the models that succeed in modelling mobility patterns in countries are not applicable in cities, which suggests that there is a diversity of human mobility at different spatial scales. Our model has potential applications in many fields relevant to mobility behaviour in cities, without relying on previous mobility measurements. PMID:25232053

  9. THE IDENTIFICATION AND TESTING OF INTERACTION PATTERNS

    EPA Science Inventory

    This paper presents a method for identifying and assessing the significance of interaction patterns among various chemicals and chemical classes of importance to regulatory toxicologists. To this end, efforts were made to assemble and evaluate experimental data on toxicologically...

  10. Immigration Patterns, Public Opinion, and Government Policy.

    ERIC Educational Resources Information Center

    Mueller, Jean West; Schamel, Wynell Burroughs

    1990-01-01

    Presents a lesson plan for illustrating how shifting patterns of immigration and public reaction have influenced public policy toward immigration restriction. Details objectives and procedures for activities using National Archives documents. Includes a worksheet and copies of government documents. (CH)

  11. Visual pattern degradation based image quality assessment

    NASA Astrophysics Data System (ADS)

    Wu, Jinjian; Li, Leida; Shi, Guangming; Lin, Weisi; Wan, Wenfei

    2015-08-01

    In this paper, we introduce a visual pattern degradation based full-reference (FR) image quality assessment (IQA) method. Researches on visual recognition indicate that the human visual system (HVS) is highly adaptive to extract visual structures for scene understanding. Existing structure degradation based IQA methods mainly take local luminance contrast to represent structure, and measure quality as degradation on luminance contrast. In this paper, we suggest that structure includes not only luminance contrast but also orientation information. Therefore, we analyze the orientation characteristic for structure description. Inspired by the orientation selectivity mechanism in the primary visual cortex, we introduce a novel visual pattern to represent the structure of a local region. Then, the quality is measured as the degradations on both luminance contrast and visual pattern. Experimental results on Five benchmark databases demonstrate that the proposed visual pattern can effectively represent visual structure and the proposed IQA method performs better than the existing IQA metrics.

  12. Visual cluster analysis and pattern recognition methods

    DOEpatents

    Osbourn, Gordon Cecil; Martinez, Rubel Francisco

    2001-01-01

    A method of clustering using a novel template to define a region of influence. Using neighboring approximation methods, computation times can be significantly reduced. The template and method are applicable and improve pattern recognition techniques.

  13. The compass rose pattern in electricity prices.

    PubMed

    Batten, Jonathan A; Hamada, Mahmoud

    2009-12-01

    The "compass rose pattern" is known to appear in the phase portraits, or scatter diagrams, of the high-frequency returns of financial series. We first show that this pattern is also present in the returns of spot electricity prices. Early researchers investigating these phenomena hoped that these patterns signaled the presence of rich dynamics, possibly chaotic or fractal in nature. Although there is a definite autoregressive and conditional heteroscedasticity structure in electricity returns, we find that after simple filtering no pattern remains. While the series is non-normal in terms of their distribution and statistical tests fail to identify significant chaos, there is evidence of fractal structures in periodic price returns when measured over the trading day. The phase diagram of the filtered returns provides a useful visual check on independence, a property necessary for pricing and trading derivatives and portfolio construction, as well as providing useful insights into the market dynamics.

  14. Pattern formation in superdiffusion Oregonator model

    NASA Astrophysics Data System (ADS)

    Feng, Fan; Yan, Jia; Liu, Fu-Cheng; He, Ya-Feng

    2016-10-01

    Pattern formations in an Oregonator model with superdiffusion are studied in two-dimensional (2D) numerical simulations. Stability analyses are performed by applying Fourier and Laplace transforms to the space fractional reaction-diffusion systems. Antispiral, stable turing patterns, and travelling patterns are observed by changing the diffusion index of the activator. Analyses of Floquet multipliers show that the limit cycle solution loses stability at the wave number of the primitive vector of the travelling hexagonal pattern. We also observed a transition between antispiral and spiral by changing the diffusion index of the inhibitor. Project supported by the National Natural Science Foundation of China (Grant Nos. 11205044 and 11405042), the Research Foundation of Education Bureau of Hebei Province, China (Grant Nos. Y2012009 and ZD2015025), the Program for Young Principal Investigators of Hebei Province, China, and the Midwest Universities Comprehensive Strength Promotion Project.

  15. Sequential pattern formation governed by signaling gradients

    NASA Astrophysics Data System (ADS)

    Jörg, David J.; Oates, Andrew C.; Jülicher, Frank

    2016-10-01

    Rhythmic and sequential segmentation of the embryonic body plan is a vital developmental patterning process in all vertebrate species. However, a theoretical framework capturing the emergence of dynamic patterns of gene expression from the interplay of cell oscillations with tissue elongation and shortening and with signaling gradients, is still missing. Here we show that a set of coupled genetic oscillators in an elongating tissue that is regulated by diffusing and advected signaling molecules can account for segmentation as a self-organized patterning process. This system can form a finite number of segments and the dynamics of segmentation and the total number of segments formed depend strongly on kinetic parameters describing tissue elongation and signaling molecules. The model accounts for existing experimental perturbations to signaling gradients, and makes testable predictions about novel perturbations. The variety of different patterns formed in our model can account for the variability of segmentation between different animal species.

  16. Patterning pentacene surfaces by local oxidation nanolithography.

    PubMed

    Losilla, N S; Martinez, J; Bystrenova, E; Greco, P; Biscarini, F; García, R

    2010-05-01

    Sequential and parallel local oxidation nanolithographies have been applied to pattern pentacene samples by creating a variety of nanostructures. The sequential local oxidation process is performed with an atomic force microscope and requires the application of a sequence of voltage pulses of 36V for 1ms. The parallel local oxidation process is performed by using a conductive and patterned stamp. Then, a voltage pulse is applied between the stamp and the pentacene surface. Patterns formed by arrays of parallel lines covering 1mm(2) regions and with a periodicity of less than 1microm have been generated in a few seconds. We also show that the patterns can be used as templates for the deposition of antibodies.

  17. Mechanisms of scaling in pattern formation

    PubMed Central

    Umulis, David M.; Othmer, Hans G.

    2013-01-01

    Many organisms and their constituent tissues and organs vary substantially in size but differ little in morphology; they appear to be scaled versions of a common template or pattern. Such scaling involves adjusting the intrinsic scale of spatial patterns of gene expression that are set up during development to the size of the system. Identifying the mechanisms that regulate scaling of patterns at the tissue, organ and organism level during development is a longstanding challenge in biology, but recent molecular-level data and mathematical modeling have shed light on scaling mechanisms in several systems, including Drosophila and Xenopus. Here, we investigate the underlying principles needed for understanding the mechanisms that can produce scale invariance in spatial pattern formation and discuss examples of systems that scale during development. PMID:24301464

  18. Radiation Pattern of Chair Armed Microstrip Antenna

    NASA Astrophysics Data System (ADS)

    Mishra, Rabindra Kishore; Sahu, Kumar Satyabrat

    2016-07-01

    This work analyzes planar antenna conformable to chair arm shaped surfaces for WLAN application. Closed form expressions for its radiation pattern are developed and validated using measurements on prototype and commercial EM code at 2.4 GHz.

  19. Lineament and polygon patterns on Europa

    NASA Technical Reports Server (NTRS)

    Pieri, D. C.

    1981-01-01

    A classification scheme is presented for the lineaments and associated polygonal patterns observed on the surface of Europa, and the frequency distribution of the polygons is discussed in terms of the stress-relief fracturing of the surface. The lineaments are divided on the basis of albedo, morphology, orientation and characteristic geometry into eight groups based on Voyager 2 images taken at a best resolution of 4 km. The lineaments in turn define a system of polygons varying in size from small reticulate patterns the limit of resolution to 1,000,000 sq km individuals. Preliminary analysis of polygon side frequency distributions reveals a class of polygons with statistics similar to those found in complex terrestrial terrains, particularly in areas of well-oriented stresses, a class with similar statistics around the antijovian point, and a class with a distribution similar to those seen in terrestrial tensional fracture patterns. Speculations concerning the processes giving rise to the lineament patterns are presented.

  20. Universal ecological patterns in college basketball communities.

    PubMed

    Warren, Robert J; Skelly, David K; Schmitz, Oswald J; Bradford, Mark A

    2011-01-01

    The rank abundance of common and rare species within ecological communities is remarkably consistent from the tropics to the tundra. This invariant patterning provides one of ecology's most enduring and unified tenets: most species rare and a few very common. Increasingly, attention is focused upon elucidating biological mechanisms that explain these species abundance distributions (SADs), but these evaluations remain controversial. We show that college basketball wins generate SADs just like those observed in ecological communities. Whereas college basketball wins are structured by competitive interactions, the result produces a SAD pattern indistinguishable from random wins. We also show that species abundance data for tropical trees exhibits a significant-digit pattern consistent with data derived from complex structuring forces. These results cast doubt upon the ability of SAD analysis to resolve ecological mechanism, and their patterning may reflect statistical artifact as much as biological processes.

  1. Microgravity effects on 'postural' muscle activity patterns

    NASA Technical Reports Server (NTRS)

    Layne, Charles S.; Spooner, Brian S.

    1994-01-01

    Changes in neuromuscular activation patterns associated with movements made in microgravity can contribute to muscular atrophy. Using electromyography (EMG) to monitor 'postural' muscles, it was found that free floating arm flexions made in microgravity were not always preceded by neuromuscular activation patterns normally observed during movements made in unit gravity. Additionally, manipulation of foot sensory input during microgravity arm flexion impacted upon anticipatory postural muscle activation.

  2. Laser patterning of laminated structures for electroplating

    DOEpatents

    Mayer, Steven T.; Evans, Leland B.

    1993-01-01

    A process for laser patterning of a substrate so that it can be subsequently electroplated or electrolessly plated. The process utilizes a laser to treat an inactive (inert) layer formed over an active layer to either combine or remove the inactive layer to produce a patterned active layer on which electrodeposition can occur. The process is carried out by utilizing laser alloying and laser etching, and involves only a few relatively high yield steps and can be performed on a very small scale.

  3. Apply Design Patterns to Refactor Software Design

    NASA Technical Reports Server (NTRS)

    Baggs, Rhoda; Shaykhian, Gholam Ali

    2007-01-01

    Refactoring software design is a method of changing software design while explicitly preserving its unique design functionalities. Presented approach is to utilize design patterns as the basis for refactoring software design. Comparison of a design solution will be made through C++ programming language examples to exploit this approach. Developing reusable component will be discussed, the paper presents that the construction of such components can diminish the added burden of both refactoring and the use of design patterns.

  4. Species Abundance Patterns in Complex Evolutionary Dynamics

    NASA Astrophysics Data System (ADS)

    Tokita, Kei

    2004-10-01

    An analytic theory of species abundance patterns (SAPs) in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka-Volterra equation, with diverse interspecies interactions. Various SAPs observed in nature are derived from a single parameter. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g., gene expression.

  5. Management of advanced hair loss patterns.

    PubMed

    Beehner, Michael L

    2013-08-01

    This article covers how to manage patients with extensive hair loss in whom complete, dense coverage is not possible. In addition to discussing planning a transplant pattern for already bald men, I discuss a conservative approach for recognizing and transplanting younger patients who have telltale warning signs that may evolve to extensive hair loss. For both groups, a variant of a frontal forelock-type pattern is usually the best course to follow.

  6. Spontaneous Patterning of Confined Granular Rods

    NASA Astrophysics Data System (ADS)

    Galanis, Jennifer; Harries, Daniel; Sackett, Dan L.; Losert, Wolfgang; Nossal, Ralph

    2006-01-01

    Vertically vibrated rod-shaped granular materials confined to quasi-2D containers self-organize into distinct patterns. We find, consistent with theory and simulation, a density dependent isotropic-nematic transition. Along the walls, rods interact sterically to form a wetting layer. For high rod densities, complex patterns emerge as a result of competition between bulk and boundary alignment. A continuum elastic energy accounting for nematic distortion and local wall anchoring reproduces the structures seen experimentally.

  7. Growth patterns of adolescents in Bahrain.

    PubMed

    Mater, A M; Alekri, S A; Mahdi, A R; Musaiger, A O

    1990-10-01

    Weight and height of adolescents in Bahrain (15.5-19.5 years) was measured to evaluate their growth patterns. A cross-sectional survey was done on 825 students that represented 5% of total secondary students. The results showed that median height and weight of Bahraini adolescents were below the 50th percentiles of the Western standard. However, when compared with earlier surveys in Bahrain, the growth pattern has improved. This is because of improvement in health and in the environment.

  8. Pattern recognition using linguistic fuzzy logic predictors

    NASA Astrophysics Data System (ADS)

    Habiballa, Hashim

    2016-06-01

    The problem of pattern recognition has been solved with numerous methods in the Artificial Intelligence field. We present an unconventional method based on Lingustic Fuzzy Logic Forecaster which is primarily used for the task of time series analysis and prediction through logical deduction wtih linguistic variables. This method should be used not only to the time series prediction itself, but also for recognition of patterns in a signal with seasonal component.

  9. Behavior patterns and coronary heart disease

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.; Cronin, J. P.

    1975-01-01

    The relationships between two behavioral patterns, cardiac risk factors, and coronary heart disease are investigated. Risk factors used in the analysis were family history of coronary disease, smoking, cholesterol, obesity, systotic blood pressure, diastolic blood pressure, blood sugar, uric acid, erythrocyte sedimentation rate, and white blood unit. It was found that conventional, non-behavioral pattern risk factors alone were not significantly related to coronary heart disease.

  10. Topological pattern selection in recurrent networks.

    PubMed

    Bahraini, Alireza; Abbassian, Abdolhossein

    2012-07-01

    The impact of adding correlation to a population of neurons on the information and the activity of the population is one of the fundamental questions in recent system neuroscience. In this paper, we would like to introduce topology-based correlation at the level of storing patterns in a recurrent network. We then study the effects of topological patterns on the activity and memory capacity of the network. The general aim of the present work is to show how the repertoire of possible stored patterns is determined by the underlying network topology. Two topological probability rules for pattern selection in recurrent network are introduced. The first one selects patterns according to a Gibbs-type distribution. We start with a Hopfield-type dynamics on a ring model and then a Langevin model on a general random graph is treated. The phenomenon of phase transition in pattern selection motivated us to introduce an alternative topological rule for pattern selection. In a network of N neurons on a random d-regular graph, two asymptotic cases, d/N→0 and d/N→1, have been discussed for the new rule, and it is shown that capacity of the network grows considerably as d/N→1. By introducing the notions of asymptotic eigenvector, we will be able to study the behaviour of the discrete model in the limit d/N→0. It will be proved that for degree d less than a critical value there is a positive role for noise, in which case increasing the number of patterns will improve the storage capacity.

  11. Bloodstain pattern analysis--casework experience.

    PubMed

    Karger, B; Rand, S; Fracasso, T; Pfeiffer, H

    2008-10-25

    The morphology of bloodstain distribution patterns at the crime scene carries vital information for a reconstruction of the events. Contrary to experimental work, case reports where the reconstruction has been verified have rarely been published. This is the reason why a series of four illustrative cases is presented where bloodstain pattern analysis at the crime scene made a reconstruction of the events possible and where this reconstruction was later verified by a confession of the offender. The cases include various types of bloodstains such as contact and smear stains, drop stains, arterial blood spatter and splash stains from both impact and cast-off pattern. Problems frequently encountered in practical casework are addressed, such as unfavourable environmental conditions or combinations of different bloodstain patterns. It is also demonstrated that the analysis of bloodstain morphology can support individualisation of stains by directing the selection of a limited number of stains from a complex pattern for DNA analysis. The complexity of real situations suggests a step-by-step approach starting with a comprehensive view of the overall picture. This is followed by a differentiation and analysis of single bloodstain patterns and a search for informative details. It is ideal when the expert inspecting the crime scene has also performed the autopsy, but he definitely must have detailed knowledge of the injuries of the deceased/injured and of the possible mechanisms of production. PMID:18790581

  12. Caenorhabditis elegans vulval cell fate patterning

    NASA Astrophysics Data System (ADS)

    Félix, Marie-Anne

    2012-08-01

    The spatial patterning of three cell fates in a row of competent cells is exemplified by vulva development in the nematode Caenorhabditis elegans. The intercellular signaling network that underlies fate specification is well understood, yet quantitative aspects remain to be elucidated. Quantitative models of the network allow us to test the effect of parameter variation on the cell fate pattern output. Among the parameter sets that allow us to reach the wild-type pattern, two general developmental patterning mechanisms of the three fates can be found: sequential inductions and morphogen-based induction, the former being more robust to parameter variation. Experimentally, the vulval cell fate pattern is robust to stochastic and environmental challenges, and minor variants can be detected. The exception is the fate of the anterior cell, P3.p, which is sensitive to stochastic variation and spontaneous mutation, and is also evolving the fastest. Other vulval precursor cell fates can be affected by mutation, yet little natural variation can be found, suggesting stabilizing selection. Despite this fate pattern conservation, different Caenorhabditis species respond differently to perturbations of the system. In the quantitative models, different parameter sets can reconstitute their response to perturbation, suggesting that network variation among Caenorhabditis species may be quantitative. Network rewiring likely occurred at longer evolutionary scales.

  13. Wettability Patterning for Enhanced Dropwise Condensation

    NASA Astrophysics Data System (ADS)

    Ghosh, Aritra; Ganguly, Ranjan; Megaridis, Constantine

    2014-11-01

    Dropwise condensation (DwC), in order to be sustainable, requires removal of the condensate droplets. This removal is frequently facilitated by gravity. The rate of DwC heat transfer depends strongly on the maximum departing droplet diameter. Based on wettability patterning, we present a facile technique designed to control the maximum droplet size in DwC within vapor/air atmospheres, and demonstrate how this approach can be used to enhance the corresponding heat transfer rate. We examine various hydrophilic-superhydrophilic patterns, which, respectively sustain DwC and filmwise (FwC) condensation on the substrate. The fabrication method does notemploy any hydrophobizing agent. By juxtaposing parallel lines of hydrophilic (CA ~ 78°) and superhydrophilic (CA ~ 0°) regions on the condensing surface, we create alternating domains of DwC and FwC. The average droplet size on the DwC domain is reduced by ~ 60% compared to the theoretical maximum, which corresponds to the line width. We compare heat transfer rate between unpatternend DwC surfaces and patterned DwC surfaces. Even after sacrificing 40% of condensing area, we achieve up to 20% improvement in condensate collection rate using an interdigitated superhydrophilic pattern, inspired by the vein network of plant leaves. The bioinspired interdigitated pattern is found to outperform the straight hydrophilic-superhydrophilic pattern, particularly under higher vapor loadings in an air/vapor ambient atmosphere. NSF STTR Grant 1331817 via NBD Nano.

  14. Accommodation, pattern glare, and coloured overlays.

    PubMed

    Allen, Peter M; Dedi, Sonia; Kumar, Dimple; Patel, Tanuj; Aloo, Mohammed; Wilkins, Arnold J

    2012-01-01

    We manipulated the accommodative response using positive and negative lenses to study any association between symptoms of pattern glare and accommodation. Two groups of eighteen young adults were selected from seventy-eight on the basis (i) that their rate of reading increased by 5% or more with an overlay compared to their rate without it, and (ii) that they reported more than 2 symptoms of pattern glare (group 1) or had no such increment in reading speed and reported fewer than 3 symptoms (group 2). Under double-masked conditions participants observed at 0.4 m a pattern of stripes while measurements of accommodation were made using an open field autorefractor with and without positive and negative trial lenses (0.75 D), and with and without a coloured overlay. Pattern glare was also assessed with and without the trial lenses. Without lenses, the mean accommodative response in group 1 was 1.55 D, a lag of 0.95 D +/- 0.24 D relative to the demand. The lag decreased by 0.43 D (p < 0.0001) when the chosen overlay was used, an effect that was not shown in group 2 even when lag increased with negative trial lenses (p = 0.13). In both groups, pattern glare scores were reduced by the trial lenses, but were unaffected by the sign of the lenses. This suggests that symptoms of pattern glare are not strongly associated with accommodative response. PMID:23586285

  15. Surface patterning of nanoparticles with polymer patches

    NASA Astrophysics Data System (ADS)

    Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; Klinkova, Anna; Larin, Egor M.; Querejeta-Fernández, Ana; Han, Lili; Xin, Huolin L.; Gang, Oleg; Zhulina, Ekaterina B.; Rubinstein, Michael; Kumacheva, Eugenia

    2016-10-01

    Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules, serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient, but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties. At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles, and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. Here we demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. These patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.

  16. Using Capillary Flows to Pattern Lines

    NASA Astrophysics Data System (ADS)

    Vyawahare, Saurabh; Craig, Kate; Scherer, Axel

    2006-03-01

    One can appreciate how capillary forces cause unexpected patterns and shapes by looking at a soap bubble. Pattern formation by surface tension is seen in ring patterns of coffee stains, fingering patterns in Hele-Shaw cells, ordering of two dimensional micro-sphere crystals, combing of DNA and skeleton formation in marine creatures called radiolarians. Though comman, problems involving the understanding and control of the self-assembly mechanism need to be resolved before using capillary forces as a practical lithographic tool. Here, we report capillary flows create line patterns in evaporating liquids between closely spaced parallel plates. The widths of these lines range from a few microns to a few nanometers. Deliberate patterning of such lines requires pinning of the contact line and the presence of foaming surfactants. The position and type of line can be controlled with artificial pinning points and varying solutes respectively, and large-scale photolithography can be used to guide and control the definition of nanostructures. We provide ``proof of principle'' demonstrations of this method's application by creating lines of colloidal quantum dots and micro-spheres. This represents the first step in using capillary phenomena to create controlled, self--assembling, one-dimensional wire-like structures

  17. Spatiotemporal patterns and predictability of cyberattacks.

    PubMed

    Chen, Yu-Zhong; Huang, Zi-Gang; Xu, Shouhuai; Lai, Ying-Cheng

    2015-01-01

    A relatively unexplored issue in cybersecurity science and engineering is whether there exist intrinsic patterns of cyberattacks. Conventional wisdom favors absence of such patterns due to the overwhelming complexity of the modern cyberspace. Surprisingly, through a detailed analysis of an extensive data set that records the time-dependent frequencies of attacks over a relatively wide range of consecutive IP addresses, we successfully uncover intrinsic spatiotemporal patterns underlying cyberattacks, where the term "spatio" refers to the IP address space. In particular, we focus on analyzing macroscopic properties of the attack traffic flows and identify two main patterns with distinct spatiotemporal characteristics: deterministic and stochastic. Strikingly, there are very few sets of major attackers committing almost all the attacks, since their attack "fingerprints" and target selection scheme can be unequivocally identified according to the very limited number of unique spatiotemporal characteristics, each of which only exists on a consecutive IP region and differs significantly from the others. We utilize a number of quantitative measures, including the flux-fluctuation law, the Markov state transition probability matrix, and predictability measures, to characterize the attack patterns in a comprehensive manner. A general finding is that the attack patterns possess high degrees of predictability, potentially paving the way to anticipating and, consequently, mitigating or even preventing large-scale cyberattacks using macroscopic approaches. PMID:25992837

  18. Bloodstain pattern analysis--casework experience.

    PubMed

    Karger, B; Rand, S; Fracasso, T; Pfeiffer, H

    2008-10-25

    The morphology of bloodstain distribution patterns at the crime scene carries vital information for a reconstruction of the events. Contrary to experimental work, case reports where the reconstruction has been verified have rarely been published. This is the reason why a series of four illustrative cases is presented where bloodstain pattern analysis at the crime scene made a reconstruction of the events possible and where this reconstruction was later verified by a confession of the offender. The cases include various types of bloodstains such as contact and smear stains, drop stains, arterial blood spatter and splash stains from both impact and cast-off pattern. Problems frequently encountered in practical casework are addressed, such as unfavourable environmental conditions or combinations of different bloodstain patterns. It is also demonstrated that the analysis of bloodstain morphology can support individualisation of stains by directing the selection of a limited number of stains from a complex pattern for DNA analysis. The complexity of real situations suggests a step-by-step approach starting with a comprehensive view of the overall picture. This is followed by a differentiation and analysis of single bloodstain patterns and a search for informative details. It is ideal when the expert inspecting the crime scene has also performed the autopsy, but he definitely must have detailed knowledge of the injuries of the deceased/injured and of the possible mechanisms of production.

  19. Wavelength selection of rippling patterns in myxobacteria.

    PubMed

    Bonilla, L L; Glavan, A; Marquina, A

    2016-01-01

    Rippling patterns of myxobacteria appear in starving colonies before they aggregate to form fruiting bodies. These periodic traveling cell density waves arise from the coordination of individual cell reversals, resulting from an internal clock regulating them and from contact signaling during bacterial collisions. Here we revisit a mathematical model of rippling in myxobacteria due to Igoshin et al. [Proc. Natl. Acad. Sci. USA 98, 14913 (2001)PNASA60027-842410.1073/pnas.221579598 and Phys. Rev. E 70, 041911 (2004)PLEEE81539-375510.1103/PhysRevE.70.041911]. Bacteria in this model are phase oscillators with an extra internal phase through which they are coupled to a mean field of oppositely moving bacteria. Previously, patterns for this model were obtained only by numerical methods, and it was not possible to find their wave number analytically. We derive an evolution equation for the reversal point density that selects the pattern wave number in the weak signaling limit, shows the validity of the selection rule by solving numerically the model equations, and describes other stable patterns in the strong signaling limit. The nonlocal mean-field coupling tends to decohere and confine patterns. Under appropriate circumstances, it can annihilate the patterns leaving a constant density state via a nonequilibrium phase transition reminiscent of destruction of synchronization in the Kuramoto model. PMID:26871106

  20. Wavelength selection of rippling patterns in myxobacteria

    NASA Astrophysics Data System (ADS)

    Bonilla, L. L.; Glavan, A.; Marquina, A.

    2016-01-01

    Rippling patterns of myxobacteria appear in starving colonies before they aggregate to form fruiting bodies. These periodic traveling cell density waves arise from the coordination of individual cell reversals, resulting from an internal clock regulating them and from contact signaling during bacterial collisions. Here we revisit a mathematical model of rippling in myxobacteria due to Igoshin et al. [Proc. Natl. Acad. Sci. USA 98, 14913 (2001), 10.1073/pnas.221579598 and Phys. Rev. E 70, 041911 (2004), 10.1103/PhysRevE.70.041911]. Bacteria in this model are phase oscillators with an extra internal phase through which they are coupled to a mean field of oppositely moving bacteria. Previously, patterns for this model were obtained only by numerical methods, and it was not possible to find their wave number analytically. We derive an evolution equation for the reversal point density that selects the pattern wave number in the weak signaling limit, shows the validity of the selection rule by solving numerically the model equations, and describes other stable patterns in the strong signaling limit. The nonlocal mean-field coupling tends to decohere and confine patterns. Under appropriate circumstances, it can annihilate the patterns leaving a constant density state via a nonequilibrium phase transition reminiscent of destruction of synchronization in the Kuramoto model.

  1. Spatiotemporal patterns and predictability of cyberattacks.

    PubMed

    Chen, Yu-Zhong; Huang, Zi-Gang; Xu, Shouhuai; Lai, Ying-Cheng

    2015-01-01

    A relatively unexplored issue in cybersecurity science and engineering is whether there exist intrinsic patterns of cyberattacks. Conventional wisdom favors absence of such patterns due to the overwhelming complexity of the modern cyberspace. Surprisingly, through a detailed analysis of an extensive data set that records the time-dependent frequencies of attacks over a relatively wide range of consecutive IP addresses, we successfully uncover intrinsic spatiotemporal patterns underlying cyberattacks, where the term "spatio" refers to the IP address space. In particular, we focus on analyzing macroscopic properties of the attack traffic flows and identify two main patterns with distinct spatiotemporal characteristics: deterministic and stochastic. Strikingly, there are very few sets of major attackers committing almost all the attacks, since their attack "fingerprints" and target selection scheme can be unequivocally identified according to the very limited number of unique spatiotemporal characteristics, each of which only exists on a consecutive IP region and differs significantly from the others. We utilize a number of quantitative measures, including the flux-fluctuation law, the Markov state transition probability matrix, and predictability measures, to characterize the attack patterns in a comprehensive manner. A general finding is that the attack patterns possess high degrees of predictability, potentially paving the way to anticipating and, consequently, mitigating or even preventing large-scale cyberattacks using macroscopic approaches.

  2. Chemically patterned flat stamps for microcontact printing.

    PubMed

    Sharpe, Ruben B A; Burdinski, Dirk; Huskens, Jurriaan; Zandvliet, Harold J W; Reinhoudt, David N; Poelsema, Bene

    2005-07-27

    Locally oxidized patterns on flat poly(dimethylsiloxane) stamps for microcontact printing were used as a platform for the transfer of a hydrophilic fluorescent ink to a glass substrate. The contrast was found to be limited. These locally oxidized patterns were conversely used as barriers for the transfer of hydrophobic n-octadecanethiol. In this case a good contrast was obtained, but the pattern was found to be susceptible to defects (cracks) in the barrier layer. Local stamp surface oxidation and subsequent modification with 1H,1H,2H,2H-perfluorodecyltrichlorosilane, for use as a barrier in the transfer of n-octadecanethiol, 16-mercaptohexadecanoic acid, and octanethiol, resulted in remarkably good contrast and stable patterns. The improved ink transfer control is ascribed to the reduction of undesired surface spreading and a superior mechanical stability of the stamp pattern. This new approach substantially expands the applicability of microcontact printing and provides a tool for the faithful reproduction of even extremely low filling ratio patterns.

  3. Preference for starting and finishing behavior patterns.

    PubMed Central

    Shimp, C P; Sabulsky, S L; Childers, L J

    1989-01-01

    Pigeon's key pecking was reinforced with food in two experiments in which the correspondence between preference for starting one of two reinforced behavior patterns and the likelihood of finishing it subsequently was examined. Reinforcers were scheduled according to concurrent schedules for two classes of interresponse times, modified such that reinforcers followed a center-key peck terminating either a shorter interresponse time started by a left-key peck or a longer interresponse time started by a right-key peck. In Experiment 1, the times when reinforcers potentially were available were not discriminated, whereas in Experiment 2 they were. Absolute reinforced pattern durations were varied. The relative frequency of starting a particular pattern was highly correlated with relative frequency of that completed pattern in both experiments. Other relations between starting and finishing a pattern depended on whether reinforced interresponse times were discriminated. For instance, preference for starting a pattern sometimes correlated negatively with the likelihood of subsequently completing it. The present experiments are described as capturing part of the ordinary language meaning of "intention," according to which an organism's behavior at one moment sets the occasion for an observer to say that the organism "intends" in the future to engage in one behavior rather than another. PMID:2584918

  4. Recent progress on multiple-patterning process

    NASA Astrophysics Data System (ADS)

    Yaegashi, Hidetami; Oyama, Kenichi; Hara, Arisa; Natori, Sakurako; Yamauchi, Shohei; Yamato, Masatoshi

    2014-03-01

    The optical projection technique with evolution of Exposure wave length (λ) and Numerical Aperture (NA) has been historically driven Photolithographic scaling. Although the delay of EUV tool for HVM has been concerned, scaling is going on steadily after limitation of 193nm-immersion technique. Double patterning process has been firstly adopted in 30nm node device of memory device, and evolved step by step from SADP, SAQP to SAOP [1][2][3]. Self-Aligned Multiple-Patterning (SAMP) with 193-immersion is getting most promising technology for further downwards scaling at the present. For the extension of 193-immersion, many solutions in mask and illumination area were suggested, and these are represented by SMO (Source and Mask Optimization) and linked to "Computational lithography". Furthermore, the change of device layout design to 1D (Single directional) layout [4] is the solution to mitigate several process issues, which are represented by process variability, pattern fidelity and Edge placement error (EPE). This paper presents the results of observing pattern fidelity in the multiple patterning process from many aspects and the results of testing a technique for high-accuracy management of pattern fidelity in 1D layout.

  5. Nearest matched filter classification of spatiotemporal patterns.

    PubMed

    Hecht-Nielsen, R

    1987-05-15

    Recent advances in massively parallel optical and electronic neural network processing technology have made it plausible to consider the use of matched filter banks containing large numbers of individual filters as pattern classifiers for complex spatiotemporal pattern environments such as speech, sonar, radar, and advanced communications. This paper begins with an overview of how neural networks can be used to approximately implement such multidimensional matched filter banks. The nearest matched filter classifier is then formally defined. This definition is then reformulated to show that the classifier is equivalent to a nearest neighbor classifier in a separable infinite-dimensional metric space that specifies the local-in-time behavior of spatiotemporal patterns. The result of Cover and Hart is then applied to show that, given a statistically comprehensive set of filter templates, the nearest matched filter classifier will have near-Bayesian performance for spatiotemporal patterns. The combination of near-Bayesian classifier performance with the excellent performance of matched filtering in noise yields a powerful new classification technique. This result adds additional interest to Grossberg's hypothesis that the mammalian cerebral cortex carries out local-in-time nearest matched filter classification of both auditory and visual sensory inputs as an initial step in sensory pattern recognition-which may help explain the almost instantaneous pattern recognition capabilities of animals.

  6. Spatiotemporal Patterns and Predictability of Cyberattacks

    PubMed Central

    Chen, Yu-Zhong; Huang, Zi-Gang; Xu, Shouhuai; Lai, Ying-Cheng

    2015-01-01

    A relatively unexplored issue in cybersecurity science and engineering is whether there exist intrinsic patterns of cyberattacks. Conventional wisdom favors absence of such patterns due to the overwhelming complexity of the modern cyberspace. Surprisingly, through a detailed analysis of an extensive data set that records the time-dependent frequencies of attacks over a relatively wide range of consecutive IP addresses, we successfully uncover intrinsic spatiotemporal patterns underlying cyberattacks, where the term “spatio” refers to the IP address space. In particular, we focus on analyzing macroscopic properties of the attack traffic flows and identify two main patterns with distinct spatiotemporal characteristics: deterministic and stochastic. Strikingly, there are very few sets of major attackers committing almost all the attacks, since their attack “fingerprints” and target selection scheme can be unequivocally identified according to the very limited number of unique spatiotemporal characteristics, each of which only exists on a consecutive IP region and differs significantly from the others. We utilize a number of quantitative measures, including the flux-fluctuation law, the Markov state transition probability matrix, and predictability measures, to characterize the attack patterns in a comprehensive manner. A general finding is that the attack patterns possess high degrees of predictability, potentially paving the way to anticipating and, consequently, mitigating or even preventing large-scale cyberattacks using macroscopic approaches. PMID:25992837

  7. Theory of ocular dominance pattern formation

    NASA Astrophysics Data System (ADS)

    Scherf, O.; Pawelzik, K.; Wolf, F.; Geisel, T.

    1999-06-01

    We investigate a general and analytically tractable model for the activity-dependent formation of neuronal connectivity patterns. Previous models are contained as limiting cases. As an important example we analyze the formation of ocular dominance patterns in the visual cortex. A linear stability analysis reveals that the model undergoes a Turing-type instability as a function of interaction range and receptive field size. The phase transitions is of second order. After the linear instability the patterns may reorganize which we analyze in terms of a potential for the dynamics. Our analysis demonstrates that the experimentally observed dependency of ocular dominance patterns on interocular correlations of visual experience during development can emerge according to two generic scenarios: either the system is driven through the phase transition during development thereby selecting and stabilizing the first unstable mode or a primary pattern reorganizes towards larger wavelength according their lower energy. Experimentally observing the time course of ocular dominance pattern formation will decide which scenario is realized in the brain.

  8. Correlation Among Lip Print Pattern, Finger Print Pattern and Abo Blood Group

    PubMed Central

    N, Srilekha; A, Anuradha; Srinivas G, Vijay; Devi R, Sabitha

    2014-01-01

    Aim: To study correlation between lip print pattern, finger print pattern and ABO blood group. Materials and Methods: The study group consisted of 27 males and 27 females who were aged between 20–40 years. Lip prints, finger prints and ABO and Rh blood groups of each individual were recorded. Lip prints were classified, based on Suzuki’s and Tsuchihashi’s classification and finger prints were classified, based on Michael’s and Kucken’s classification. The results were statistically analyzed by using Chi–square test. Results: Complete vertical lip print, loop finger print pattern, O+ blood group were predominant among individual groups. O+ blood group-type I lip print combination, loop finger print pattern-type IV lip print pattern combination, O+ blood group-loop finger print pattern combination and both B+ blood group-loop finger print pattern- type IV lip print pattern combination and O+ blood group-loop finger print pattern-type I lip print pattern were predominant. Conclusion: Though lip prints, finger prints and blood groups had their own specificities, correlation of the three parameters did not show any significance. PMID:24783079

  9. Drumlins: A Classic Example of Pattern Formation.

    NASA Astrophysics Data System (ADS)

    Ely, Jeremy C.; Clark, Chris D.; Spagnolo, Matteo; Hahn, Ute; Hughes, Anna L. C.

    2014-05-01

    Drumlins are elongate streamlined hills, typically 250-1000 m long and 120-300 m wide, formed beneath ice sheets. They occur in fields or swarms, covering vast swathes of previously glaciated terrain, and are the most common variant of a continuum of subglacial bedforms. The processes of drumlin formation are currently elusive and contentious, hindering our understanding of the ice-bed interface. Yet, insight into drumlin formation can be gained through studying their spatial distribution and morphometric properties. When viewed from above, drumlins display striking regularity and self-similarity, suggesting that they form through a self-organising pattern forming process. However, the difficulty of observing drumlins forming in situ (i.e. beneath an ice sheet), and a focus upon individual drumlin forms, has hindered both the recognition and understanding of drumlin pattern formation. Hence, the nature of drumlin patterning is poorly understood, especially in comparison to bedforms generated by other geomorphic agents (e.g. dunes and ripples). To address these issues, here we analyse the morphometric properties of a large database of drumlins mapped from palaeo-ice sheet beds at a variety of geological and glaciological settings. Spatial statistical point pattern tests suggest that drumlins are regularly spaced across drumlin fields. However, defects to this regularity occur due to differences in preservation and initial formation conditions. Furthermore, drumlin morphometric parameters frequently conform to a log-normal distribution, common for phenomena which experience incremental growth or fragmentation. Hence, drumlin morphometrics can provide us with insight into how drumlin patterns have evolved. Between separate drumlin fields, variations in patterning and morphometrics vary, highlighting the response of drumlin patterning to local glaciological and geological factors. Hence, we suggest that many of the patterning principles which have been applied to other

  10. Lysozyme pattern formation in evaporating droplets

    NASA Astrophysics Data System (ADS)

    Gorr, Heather Meloy

    Liquid droplets containing suspended particles deposited on a solid, flat surface generally form ring-like structures due to the redistribution of solute during evaporation (the "coffee ring effect"). The forms of the deposited patterns depend on complex interactions between solute(s), solvent, and substrate in a rapidly changing, far from equilibrium system. Solute self-organization during evaporation of colloidal sessile droplets has attracted the attention of researchers over the past few decades due to a variety of technological applications. Recently, pattern formation during evaporation of various biofluids has been studied due to potential applications in medical screening and diagnosis. Due to the complexity of 'real' biological fluids and other multicomponent systems, a comprehensive understanding of pattern formation during droplet evaporation of these fluids is lacking. In this PhD dissertation, the morphology of the patterns remaining after evaporation of droplets of a simplified model biological fluid (aqueous lysozyme solutions + NaCl) are examined by atomic force microscopy (AFM) and optical microscopy. Lysozyme is a globular protein found in high concentration, for example, in human tears and saliva. The drop diameters, D, studied range from the micro- to the macro- scale (1 microm -- 2 mm). In this work, the effect of evaporation conditions, solution chemistry, and heat transfer within the droplet on pattern formation is examined. In micro-scale deposits of aqueous lysozyme solutions (1 microm < D < 50 microm), the protein motion and the resulting dried residue morphology are highly influenced by the decreased evaporation time of the drop. The effect of electrolytes on pattern formation is also investigated by adding varying concentrations NaCl to the lysozyme solutions. Finally, a novel pattern recognition program is described and implemented which classifies deposit images by their solution chemistries. The results presented in this Ph

  11. Cryptically patterned moths perceive bark structure when choosing body orientations that match wing color pattern to the bark pattern.

    PubMed

    Kang, Chang-Ku; Moon, Jong-Yeol; Lee, Sang-Im; Jablonski, Piotr G

    2013-01-01

    Many moths have wing patterns that resemble bark of trees on which they rest. The wing patterns help moths to become camouflaged and to avoid predation because the moths are able to assume specific body orientations that produce a very good match between the pattern on the bark and the pattern on the wings. Furthermore, after landing on a bark moths are able to perceive stimuli that correlate with their crypticity and are able to re-position their bodies to new more cryptic locations and body orientations. However, the proximate mechanisms, i.e. how a moth finds an appropriate resting position and orientation, are poorly studied. Here, we used a geometrid moth Jankowskia fuscaria to examine i) whether a choice of resting orientation by moths depends on the properties of natural background, and ii) what sensory cues moths use. We studied moths' behavior on natural (a tree log) and artificial backgrounds, each of which was designed to mimic one of the hypothetical cues that moths may perceive on a tree trunk (visual pattern, directional furrow structure, and curvature). We found that moths mainly used structural cues from the background when choosing their resting position and orientation. Our findings highlight the possibility that moths use information from one type of sensory modality (structure of furrows is probably detected through tactile channel) to achieve crypticity in another sensory modality (visual). This study extends our knowledge of how behavior, sensory systems and morphology of animals interact to produce crypsis.

  12. Pattern drilling exploration: Optimum pattern types and hole spacings when searching for elliptical shaped targets

    USGS Publications Warehouse

    Drew, L.J.

    1979-01-01

    In this study the selection of the optimum type of drilling pattern to be used when exploring for elliptical shaped targets is examined. The rhombic pattern is optimal when the targets are known to have a preferred orientation. Situations can also be found where a rectangular pattern is as efficient as the rhombic pattern. A triangular or square drilling pattern should be used when the orientations of the targets are unknown. The way in which the optimum hole spacing varies as a function of (1) the cost of drilling, (2) the value of the targets, (3) the shape of the targets, (4) the target occurrence probabilities was determined for several examples. Bayes' rule was used to show how target occurrence probabilities can be revised within a multistage pattern drilling scheme. ?? 1979 Plenum Publishing Corporation.

  13. Annual snowpack patterns across the Rockies: Long-term trends and associated 500-mb synoptic patterns

    SciTech Connect

    Changnon, D. ); McKee, T.B.; Doesken, N.J. )

    1993-03-01

    Winter snowpack was investigated to determine spatial and temporal climate variability in a five-state region (Colorado, Idaho, Montana, Utah, and Wyoming) in the northern Rocky Mountains, covering the period 1951-1985. Annual 1 April snowpack (SN) measurements were selected for analyses. Three basic and persistent patterns of annual SN values surfaced: years with a consistent anomaly over the entire region (wet or dry); years with a distinct north-to-south gradient; and average years. Nearly 90% of the nonaverage annual SN patterns were explained by the frequency of seven 500-mb winter synoptic patterns. The wet-north-dry-south gradient SN patterns occurred only before 1974, and the dry-north-wet-south gradient southern areas of the five-state region are due to periods when one of the two north-to-south gradient SN patterns occurred and are explained by the changes in the frequency of synoptic patterns. 20 refs., 19 figs., 6 tabs.

  14. Post hoc pattern matching: assigning significance to statistically defined expression patterns in single channel microarray data

    PubMed Central

    Hulshizer, Randall; Blalock, Eric M

    2007-01-01

    Background Researchers using RNA expression microarrays in experimental designs with more than two treatment groups often identify statistically significant genes with ANOVA approaches. However, the ANOVA test does not discriminate which of the multiple treatment groups differ from one another. Thus, post hoc tests, such as linear contrasts, template correlations, and pairwise comparisons are used. Linear contrasts and template correlations work extremely well, especially when the researcher has a priori information pointing to a particular pattern/template among the different treatment groups. Further, all pairwise comparisons can be used to identify particular, treatment group-dependent patterns of gene expression. However, these approaches are biased by the researcher's assumptions, and some treatment-based patterns may fail to be detected using these approaches. Finally, different patterns may have different probabilities of occurring by chance, importantly influencing researchers' conclusions about a pattern and its constituent genes. Results We developed a four step, post hoc pattern matching (PPM) algorithm to automate single channel gene expression pattern identification/significance. First, 1-Way Analysis of Variance (ANOVA), coupled with post hoc 'all pairwise' comparisons are calculated for all genes. Second, for each ANOVA-significant gene, all pairwise contrast results are encoded to create unique pattern ID numbers. The # genes found in each pattern in the data is identified as that pattern's 'actual' frequency. Third, using Monte Carlo simulations, those patterns' frequencies are estimated in random data ('random' gene pattern frequency). Fourth, a Z-score for overrepresentation of the pattern is calculated ('actual' against 'random' gene pattern frequencies). We wrote a Visual Basic program (StatiGen) that automates PPM procedure, constructs an Excel workbook with standardized graphs of overrepresented patterns, and lists of the genes comprising

  15. Pattern recognition with "materials that compute".

    PubMed

    Fang, Yan; Yashin, Victor V; Levitan, Steven P; Balazs, Anna C

    2016-09-01

    Driven by advances in materials and computer science, researchers are attempting to design systems where the computer and material are one and the same entity. Using theoretical and computational modeling, we design a hybrid material system that can autonomously transduce chemical, mechanical, and electrical energy to perform a computational task in a self-organized manner, without the need for external electrical power sources. Each unit in this system integrates a self-oscillating gel, which undergoes the Belousov-Zhabotinsky (BZ) reaction, with an overlaying piezoelectric (PZ) cantilever. The chemomechanical oscillations of the BZ gels deflect the PZ layer, which consequently generates a voltage across the material. When these BZ-PZ units are connected in series by electrical wires, the oscillations of these units become synchronized across the network, where the mode of synchronization depends on the polarity of the PZ. We show that the network of coupled, synchronizing BZ-PZ oscillators can perform pattern recognition. The "stored" patterns are set of polarities of the individual BZ-PZ units, and the "input" patterns are coded through the initial phase of the oscillations imposed on these units. The results of the modeling show that the input pattern closest to the stored pattern exhibits the fastest convergence time to stable synchronization behavior. In this way, networks of coupled BZ-PZ oscillators achieve pattern recognition. Further, we show that the convergence time to stable synchronization provides a robust measure of the degree of match between the input and stored patterns. Through these studies, we establish experimentally realizable design rules for creating "materials that compute."

  16. Pattern recognition with "materials that compute".

    PubMed

    Fang, Yan; Yashin, Victor V; Levitan, Steven P; Balazs, Anna C

    2016-09-01

    Driven by advances in materials and computer science, researchers are attempting to design systems where the computer and material are one and the same entity. Using theoretical and computational modeling, we design a hybrid material system that can autonomously transduce chemical, mechanical, and electrical energy to perform a computational task in a self-organized manner, without the need for external electrical power sources. Each unit in this system integrates a self-oscillating gel, which undergoes the Belousov-Zhabotinsky (BZ) reaction, with an overlaying piezoelectric (PZ) cantilever. The chemomechanical oscillations of the BZ gels deflect the PZ layer, which consequently generates a voltage across the material. When these BZ-PZ units are connected in series by electrical wires, the oscillations of these units become synchronized across the network, where the mode of synchronization depends on the polarity of the PZ. We show that the network of coupled, synchronizing BZ-PZ oscillators can perform pattern recognition. The "stored" patterns are set of polarities of the individual BZ-PZ units, and the "input" patterns are coded through the initial phase of the oscillations imposed on these units. The results of the modeling show that the input pattern closest to the stored pattern exhibits the fastest convergence time to stable synchronization behavior. In this way, networks of coupled BZ-PZ oscillators achieve pattern recognition. Further, we show that the convergence time to stable synchronization provides a robust measure of the degree of match between the input and stored patterns. Through these studies, we establish experimentally realizable design rules for creating "materials that compute." PMID:27617290

  17. Reconsidering the origins of Forsbergh birefringence patterns

    NASA Astrophysics Data System (ADS)

    Schilling, A.; Kumar, A.; McQuaid, R. G. P.; Glazer, A. M.; Thomas, P. A.; Gregg, J. M.

    2016-07-01

    In 1949, Forsbergh, Jr. reported spontaneous spatial ordering in the birefringence patterns seen in flux-grown BaTi O3 crystals under the transmission polarized light microscope [Phys. Rev. 76, 1187 (1949), 10.1103/PhysRev.76.1187]. Stunningly regular square-net arrays were often only found within a finite temperature window and could be induced on both heating and cooling, suggesting genuine thermodynamic stability. At the time, Forsbergh rationalized the patterns to have resulted from the impingement of ferroelastic domains, creating a complex tessellation of variously shaped domain packets. However, no direct evidence for the intricate microstructural arrangement proposed by Forsbergh has subsequently been found. Moreover, there are no robust thermodynamic arguments to explain the finite region of thermal stability, its occurrence just below the Curie temperature, and the apparent increase in entropy associated with the loss of the Forsbergh pattern on cooling. Despite decades of research on ferroelectrics, this ordering phenomenon and its thermodynamic origin have hence remained a mystery. In this paper, we reexamine the microstructure of flux-grown BaTi O3 crystals, which show Forsbergh birefringence patterns. Given an absence of any obvious arrays of domain polyhedra or even regular shapes of domain packets, we suggest an alternative origin for the Forsbergh pattern in which sheets of orthogonally oriented ferroelastic stripe domains simply overlay one another. We show explicitly that the Forsbergh birefringence pattern occurs if the periodicity of the stripe domains is above a critical value. Moreover, by considering well-established semiempirical models, we show that the significant domain coarsening needed to generate the Forsbergh birefringence is fully expected in a finite window below the Curie temperature. We hence present a much more straightforward rationalization of the Forsbergh pattern than that originally proposed in which exotic thermodynamic

  18. Geometry-induced protein pattern formation.

    PubMed

    Thalmeier, Dominik; Halatek, Jacob; Frey, Erwin

    2016-01-19

    Protein patterns are known to adapt to cell shape and serve as spatial templates that choreograph downstream processes like cell polarity or cell division. However, how can pattern-forming proteins sense and respond to the geometry of a cell, and what mechanistic principles underlie pattern formation? Current models invoke mechanisms based on dynamic instabilities arising from nonlinear interactions between proteins but neglect the influence of the spatial geometry itself. Here, we show that patterns can emerge as a direct result of adaptation to cell geometry, in the absence of dynamical instability. We present a generic reaction module that allows protein densities robustly to adapt to the symmetry of the spatial geometry. The key component is an NTPase protein that cycles between nucleotide-dependent membrane-bound and cytosolic states. For elongated cells, we find that the protein dynamics generically leads to a bipolar pattern, which vanishes as the geometry becomes spherically symmetrical. We show that such a reaction module facilitates universal adaptation to cell geometry by sensing the local ratio of membrane area to cytosolic volume. This sensing mechanism is controlled by the membrane affinities of the different states. We apply the theory to explain AtMinD bipolar patterns in [Formula: see text] EcMinDE Escherichia coli. Due to its generic nature, the mechanism could also serve as a hitherto-unrecognized spatial template in many other bacterial systems. Moreover, the robustness of the mechanism enables self-organized optimization of protein patterns by evolutionary processes. Finally, the proposed module can be used to establish geometry-sensitive protein gradients in synthetic biological systems.

  19. Advanced Pattern Material for Investment Casting Applications

    SciTech Connect

    F. Douglas Neece Neil Chaudhry

    2006-02-08

    Cleveland Tool and Machine (CTM) of Cleveland, Ohio in conjunction with Harrington Product Development Center (HPDC) of Cincinnati, Ohio have developed an advanced, dimensionally accurate, temperature-stable, energy-efficient and cost-effective material and process to manufacture patterns for the investment casting industry. In the proposed technology, FOPAT (aFOam PATtern material) has been developed which is especially compatible with the investment casting process and offers the following advantages: increased dimensional accuracy; increased temperature stability; lower cost per pattern; less energy consumption per pattern; decreased cost of pattern making equipment; decreased tooling cost; increased casting yield. The present method for investment casting is "the lost wax" process, which is exactly that, the use of wax as a pattern material, which is then melted out or "lost" from the ceramic shell. The molten metal is then poured into the ceramic shell to produce a metal casting. This process goes back thousands of years and while there have been improvements in the wax and processing technology, the material is basically the same, wax. The proposed technology is based upon an established industrial process of "Reaction Injection Molding" (RIM) where two components react when mixed and then "molded" to form a part. The proposed technology has been modified and improved with the needs of investment casting in mind. A proprietary mix of components has been formulated which react and expand to form a foam-like product. The result is an investment casting pattern with smooth surface finish and excellent dimensional predictability along with the other key benefits listed above.

  20. Effective Spine Triage: Patterns of Pain

    PubMed Central

    Hall, Hamilton

    2014-01-01

    Background The most common cause of recurring lost time from work, low back pain is a huge burden on society. Medical training dictates that we must establish a cause for pain before we can treat it and then base our treatment on a recognized and agreed-upon pathology. But in the overwhelming majority of low back pain cases, the issue is nothing more than a minor mechanical malfunction, the inevitable consequence of normal wear and tear. The severity of the pain does not reflect the benign nature of the underlying problem and its limited extent makes a definitive diagnosis impossible. One important component of the solution is improved spinal triage. Using patterns or syndromes in the initial assessment of low back pain is gaining renewed interest and clinical acceptance. Methods Identifying a patient's pain pattern is achieved primarily through an assessment of the patient's history. The patient interview begins with a series of questions to determine the specific syndrome. A subsequent physical examination supports or refutes the findings in history. Combining information from the history with the findings of the physical examination, the clinician has the ability to rule out a number of potentially grim diagnoses. Results More than 90% of back pain patients have benign mechanical problems and their pain can be classified into 4 distinct patterns: 2 back-dominant patterns and 2 leg-dominant patterns. Conclusion A clinical perspective capable of recognizing a defined syndrome at first contact will lead to a better outcome. Most patients with low back pain can be treated successfully with simple, pattern-specific, noninvasive primary management. Patients without a pattern and those who do not respond as anticipated require further investigation and specialized care. PMID:24688339

  1. Face recognition system and method using face pattern words and face pattern bytes

    SciTech Connect

    Zheng, Yufeng

    2014-12-23

    The present invention provides a novel system and method for identifying individuals and for face recognition utilizing facial features for face identification. The system and method of the invention comprise creating facial features or face patterns called face pattern words and face pattern bytes for face identification. The invention also provides for pattern recognitions for identification other than face recognition. The invention further provides a means for identifying individuals based on visible and/or thermal images of those individuals by utilizing computer software implemented by instructions on a computer or computer system and a computer readable medium containing instructions on a computer system for face recognition and identification.

  2. Applicability of double-patterning process for fine-hole patterns

    NASA Astrophysics Data System (ADS)

    Yamauchi, Shohei; Hara, Arisa; Oyama, Kenichi; Natori, Sakurako; Yaegashi, Hidetami

    2012-03-01

    Self-aligned spacer Double Patterning (SADP) has been adopted in HVM of NAND FLASH memory device, because SADP can fabricate fine periodical line pattern more easily than pitch-split type DP. Furthermore, SADP can mitigate overlay accuracy such like pith-split type DP needed. The remarkable feature of SADP process is the adoption of a SiO2 film that can be deposited at extremely low temperatures for spacer formation. SADP and this deposition process also produce wide applicability to density multiplication on hole pattern. In our previous study, hole pattern fabrication below 40nmhp was examined. 30nm hp hole pattern was viable with single 193-immersion exposure successfully with our newly developed process scheme named EKB, and ultimate down-scaling on hole pattern, achieved to 20nm hp, was introduced utilizing cross-SADP[1][2]. In logic device manufacturing, pattern layout is getting to single directional, tabbed Gridded design rule (GDR) for the mitigation of various lithographic issues. Although Self-aligned type DP for hole pattern can describe periodical layout, it is really enabled for future simplified pattern layout. In this paper, successful demonstration results would be introduced in process simplification, process extendibility, CD controllability and further downward scaling.

  3. On Pattern Formation Mechanisms for Lepidopteran Wing Patterns and Mammalian Coat Markings

    NASA Astrophysics Data System (ADS)

    Murray, J. D.

    1981-10-01

    The patterns on wings of Lepidoptera can be generated with a few pattern elements, but no mechanism has been suggested for producing them. I consider two of the basic patterns, namely, central symmetry and dependent patterns. A biochemically plausible model mechanism is proposed for generating major aspects of these patterns, based on a diffusing morphogen that activates a gene or colour-specific enzyme in a threshold manner to generate a stable heterogeneous spatial pattern. The model is applied to the determination stream hypothesis of Kuhn & von Engelhardt (Wilhelm Roux Arch. Entw Mech. Org. 130, 660 (1933)), and results from the model compared with their microcautery experiments on the pupal wing of Ephestia kuhniella. In the case of dependent patterns, results are compared with patterns on specific Papilionidae. For the same mechanism and a fixed set of parameters I demonstrate the important roles of geometry and scale on the spatial patterns obtained. The results and evidence presented here suggest the existence of diffusion fields of the order of several millimetres, which are very much larger than most embryonic fields. The existence of zones of polarizing activity is also indicated. Colour patterns on animals are considered to be genetically determined, but the mechanism is not known. I have previously suggested that a single mechanism that can exhibit an infinite variety of patterns is a candidate for that mechanism, and proposed that a reaction-diffusion system that can be diffusively driven unstable could be responsible for the laying down of the spacing patterns that generates the prepattern for animal coat markings. For illustrative purposes I consider a practical reaction mechanism, which exhibits substrate inhibition, and show that the geometry and scale of the domain (part of the epidermis) play a crucial role in the structural patterns that result. Patterns are obtained for a selection of geometries, and general features are related to the coat

  4. Understanding conoscopic interference patterns in anisotropic crystals

    NASA Astrophysics Data System (ADS)

    Olorunsola, Oluwatobi Gabriel

    The interference patterns observed in conoscopy are important in studying the optical and geometrical properties of anisotropic materials. They have also been used to identify minerals and to explore the structure of biological tissues. In a conoscopic interferometer, an optically anisotropic specimen is placed between two crossed linear polarizers and illuminated by a convergent light beam. The interference patterns are produced because in an anisotropic material an incident light is split into two eigenwaves, namely the ordinary and the extraordinary waves. We report our work on the theoretical simulation and experimental observation of the conoscopic interference patterns in anisotropic crystals. In our simulation, the interference patterns are decomposed into fringes of isogyres and isochromates. For each light propagation direction inside the crystal there exist two eigenwaves that have their own characteristic velocities and vibration directions. The isogyres are obtained by computing the angle between the polarization of the incident light and the vibration directions of the two eigenwaves. The isochromates are obtained by computing the phase retardance between the two eigenwaves inside the crystal. The interference patterns are experimentally observed in several crystals, with their optic axes either parallel or perpendicular to their surfaces. An external electric field is applied to deform the crystals from uniaxial to biaxial. The results of our experimental observation agree well with our computer simulation. In conventional interferometers the isochromatic interference fringes are observed by using a circular polarizer and a circular analyzer, both constructed by a linear polarizer and a quarter wave plate. However, due to the dispersion of the quarter wave plates, the phase-retardance between the two light waves inside the quarter wave plates is wavelength-dependent, which results in different conoscopic interference patterns for different colors of

  5. Enhancing dropwise condensation through bioinspired wettability patterning.

    PubMed

    Ghosh, Aritra; Beaini, Sara; Zhang, Bong June; Ganguly, Ranjan; Megaridis, Constantine M

    2014-11-01

    Dropwise condensation (DWC) heat transfer depends strongly on the maximum diameter (Dmax) of condensate droplets departing from the condenser surface. This study presents a facile technique implemented to gain control of Dmax in DWC within vapor/air atmospheres. We demonstrate how this approach can enhance the corresponding heat transfer rate by harnessing the capillary forces in the removal of the condensate from the surface. We examine various hydrophilic-superhydrophilic patterns, which, respectively, sustain and combine DWC and filmwise condensation on the substrate. The material system uses laser-patterned masking and chemical etching to achieve the desired wettability contrast and does not employ any hydrophobizing agent. By applying alternating straight parallel strips of hydrophilic (contact angle ∼78°) mirror-finish aluminum and superhydrophilic regions (etched aluminum) on the condensing surface, we show that the average maximum droplet size on the less-wettable domains is nearly 42% of the width of the corresponding strips. An overall improvement in the condensate collection rate, up to 19% (as compared to the control case of DWC on mirror-finish aluminum) was achieved by using an interdigitated superhydrophilic track pattern (on the mirror-finish hydrophilic surface) inspired by the vein network of plant leaves. The bioinspired interdigitated pattern is found to outperform the straight hydrophilic-superhydrophilic pattern design, particularly under higher humidity conditions in the presence of noncondensable gases (NCG), a condition that is more challenging for maintaining sustained DWC.

  6. Patterning of Indium Tin Oxide Films

    NASA Technical Reports Server (NTRS)

    Immer, Christopher

    2008-01-01

    A relatively rapid, economical process has been devised for patterning a thin film of indium tin oxide (ITO) that has been deposited on a polyester film. ITO is a transparent, electrically conductive substance made from a mixture of indium oxide and tin oxide that is commonly used in touch panels, liquid-crystal and plasma display devices, gas sensors, and solar photovoltaic panels. In a typical application, the ITO film must be patterned to form electrodes, current collectors, and the like. Heretofore it has been common practice to pattern an ITO film by means of either a laser ablation process or a photolithography/etching process. The laser ablation process includes the use of expensive equipment to precisely position and focus a laser. The photolithography/etching process is time-consuming. The present process is a variant of the direct toner process an inexpensive but often highly effective process for patterning conductors for printed circuits. Relative to a conventional photolithography/ etching process, this process is simpler, takes less time, and is less expensive. This process involves equipment that costs less than $500 (at 2005 prices) and enables patterning of an ITO film in a process time of less than about a half hour.

  7. [Interstitial lung diseases. The pattern is important].

    PubMed

    Fink, L

    2014-11-01

    Interstitial lung diseases (ILDs) comprise a number of rare entities with an estimated incidence of 10-25 per 100,000 inhabitants but the incidence greatly increases beyond the age of 65 years. The prognosis depends on the underlying cause. The fibrotic disorders show a set of radiological and histopathological patterns that are distinct but not entirely specific. In the absence of a clear clinical picture and consistent high resolution computed tomography (HRCT) findings, patients are advised to undergo surgical lung biopsies from two or three lung lobes (or transbronchial biopsies) to determine the histopathological pattern. The ILDs are differentiated into disorders of known causes (e.g. collagen vascular disease, drug-related), idiopathic interstitial pneumonia (IIP), granulomatous ILDs (e.g. sarcoidosis) and other forms of ILD (e.g. Langerhans' cell histiocytosis). The IIPs encompass idiopathic pulmonary fibrosis (IPF), non-specific interstitial pneumonia, desquamative interstitial pneumonia, respiratory bronchiolitis-interstitial lung disease, cryptogen organizing pneumonia, lymphocytic interstitial pneumonia and acute interstitial pneumonia. Additionally, a category of unclassified interstitial pneumonia exists. The pathologist has to recognize and address the histopathological pattern. In a multidisciplinary discussion the disorder is allocated to a clinicopathological entity and the histopathological pattern plays a major role in the classification of the entity. Recognition of the underlying pattern and the respective histopathological differential diagnoses is important as the therapy varies depending on the cause and ranges from elimination of the stimulus (if possible) to antifibrotic drug therapy up to preparation for lung transplantation.

  8. Optimal flux patterns in cellular metabolic networks

    NASA Astrophysics Data System (ADS)

    Almaas, Eivind

    2007-06-01

    The availability of whole-cell-level metabolic networks of high quality has made it possible to develop a predictive understanding of bacterial metabolism. Using the optimization framework of flux balance analysis, I investigate the metabolic response and activity patterns to variations in the availability of nutrient and chemical factors such as oxygen and ammonia by simulating 30 000 random cellular environments. The distribution of reaction fluxes is heavy tailed for the bacteria H. pylori and E. coli, and the eukaryote S. cerevisiae. While the majority of flux balance investigations has relied on implementations of the simplex method, it is necessary to use interior-point optimization algorithms to adequately characterize the full range of activity patterns on metabolic networks. The interior-point activity pattern is bimodal for E. coli and S. cerevisiae, suggesting that most metabolic reactions are either in frequent use or are rarely active. The trimodal activity pattern of H. pylori indicates that a group of its metabolic reactions (20%) are active in approximately half of the simulated environments. Constructing the high-flux backbone of the network for every environment, there is a clear trend that the more frequently a reaction is active, the more likely it is a part of the backbone. Finally, I briefly discuss the predicted activity patterns of the central carbon metabolic pathways for the sample of random environments.

  9. Temporal sleep patterns in adults using actigraph.

    PubMed

    Matuzaki, Lia; Santos-Silva, Rogerio; Marqueze, Elaine Cristina; de Castro Moreno, Claudia Roberta; Tufik, Sergio; Bittencourt, Lia

    2014-09-01

    The aim of the present study was to characterize the temporal patterns of sleep and wakefulness in a sample of the adult subjects from São Paulo city. All subjects filled the Morningness/Eveningness Questionnaire (MEQ) and wore an actigraph for at least three consecutive days. A total of 359 subjects were considered for the analyses. The mean age was 43±14 years, the mean body mass index was 26.7±5.7 kg/m(2), and 60% were female. The mean MEQ score was 58.0±10.7. The sleep pattern evaluated by the actigraphic analyses showed that 92% had a monophasic sleep pattern, 7% biphasic, and 1% polyphasic sleep pattern. Cluster analysis, based on time to sleep onset, sleep efficiency, sleep latency, and total sleep time, was able to identify three different groups denominated: morning type, evening type, and undefined type. Morning type subjects were more frequent, older, and had higher MEQ scores than evening type subjects. Our results showed that the actigraph objectively assessed the sleep-wake cycle and was able to discriminate between morning and evening type individuals. These findings suggest that the actigraph could be a valuable tool for assessing temporal sleep patterns, including the circadian preferences. PMID:26483920

  10. Optimal flux patterns in cellular metabolic networks

    SciTech Connect

    Almaas, E

    2007-01-20

    The availability of whole-cell level metabolic networks of high quality has made it possible to develop a predictive understanding of bacterial metabolism. Using the optimization framework of flux balance analysis, I investigate metabolic response and activity patterns to variations in the availability of nutrient and chemical factors such as oxygen and ammonia by simulating 30,000 random cellular environments. The distribution of reaction fluxes is heavy-tailed for the bacteria H. pylori and E. coli, and the eukaryote S. cerevisiae. While the majority of flux balance investigations have relied on implementations of the simplex method, it is necessary to use interior-point optimization algorithms to adequately characterize the full range of activity patterns on metabolic networks. The interior-point activity pattern is bimodal for E. coli and S. cerevisiae, suggesting that most metabolic reaction are either in frequent use or are rarely active. The trimodal activity pattern of H. pylori indicates that a group of its metabolic reactions (20%) are active in approximately half of the simulated environments. Constructing the high-flux backbone of the network for every environment, there is a clear trend that the more frequently a reaction is active, the more likely it is a part of the backbone. Finally, I briefly discuss the predicted activity patterns of the central-carbon metabolic pathways for the sample of random environments.

  11. Temporal sleep patterns in adults using actigraph

    PubMed Central

    Matuzaki, Lia; Santos-Silva, Rogerio; Marqueze, Elaine Cristina; de Castro Moreno, Claudia Roberta; Tufik, Sergio; Bittencourt, Lia

    2014-01-01

    The aim of the present study was to characterize the temporal patterns of sleep and wakefulness in a sample of the adult subjects from São Paulo city. All subjects filled the Morningness/Eveningness Questionnaire (MEQ) and wore an actigraph for at least three consecutive days. A total of 359 subjects were considered for the analyses. The mean age was 43±14 years, the mean body mass index was 26.7±5.7 kg/m2, and 60% were female. The mean MEQ score was 58.0±10.7. The sleep pattern evaluated by the actigraphic analyses showed that 92% had a monophasic sleep pattern, 7% biphasic, and 1% polyphasic sleep pattern. Cluster analysis, based on time to sleep onset, sleep efficiency, sleep latency, and total sleep time, was able to identify three different groups denominated: morning type, evening type, and undefined type. Morning type subjects were more frequent, older, and had higher MEQ scores than evening type subjects. Our results showed that the actigraph objectively assessed the sleep-wake cycle and was able to discriminate between morning and evening type individuals. These findings suggest that the actigraph could be a valuable tool for assessing temporal sleep patterns, including the circadian preferences. PMID:26483920

  12. Transcranial direct current stimulation modulates pattern separation.

    PubMed

    Cappiello, Marcus; Xie, Weizhen; David, Alexander; Bikson, Marom; Zhang, Weiwei

    2016-08-01

    Maintaining similar memories in a distinct and nonoverlapping manner, known as pattern separation, is an important mnemonic process. The medial temporal lobe, especially the hippocampus, has been implicated in this crucial memory function. The present study thus examines whether it is possible to modulate pattern separation using bilateral transcranial direct current stimulation (tDCS) over the temporal lobes. Specifically, in this study, pattern separation was assessed using the Mnemonic Similarity Task following 15-min offline bilateral temporal lobe tDCS (left cathode and right anode or left anode and right cathode) or sham stimulation. In the Mnemonic Similarity Task, participants studied a series of sequentially presented visual objects. In the subsequent recognition memory test, participants viewed a series of sequentially presented objects that could be old images from study, novel foils, or lures that were visually similar to the studied images. Participants reported whether these images were exactly the same as, similar to, or different from the studied images. Following both active tDCS conditions, participants were less likely to identify lures as 'similar' compared with the sham condition, indicating a reduction in pattern separation resulting from temporal lobe tDCS. In contrast, no significant difference in overall accuracy was found for participants' discrimination of old and new images. Together, these results suggest that temporal lobe tDCS can selectively modulate the pattern separation function without changing participants' baseline recognition memory performance. PMID:27285728

  13. Venous Drainage Patterns in Carotid Cavernous Fistulas

    PubMed Central

    Aralasmak, Ayse; Karaali, Kamil; Senol, Utku; Ozdemir, Huseyin; Alkan, Alpay

    2014-01-01

    Purpose. The carotid-cavernous fistula (CCF) is an abnormal arteriovenous communication and its drainage pathways may affect the clinic presentation and change treatment approach. We evaluated drainage patterns of CCFs by digital subtraction angiography (DSA) and categorized drainage pathways according to their types and etiology. Materials and Methods. Venous drainage patterns of 13 CCFs from 10 subjects were studied and categorized as anterior, posterior, superior, inferior, and contralateral on DSA. Drainage patterns were correlated to types and etiology of CCFs. Diagnosis of CCFs was first made by noninvasive imaging techniques. Results. On DSA, traumatic CCFs were usually high flow, direct type while spontaneous CCFs were usually slow flow, indirect type. Bilaterality and mixed types were observed among the indirect spontaneous CCFs. In all CCFs, anterior and inferior drainages were the most common. Contrary to the literature, posterior and superior drainages were noted only in high flow and long standing direct fistulas. Contralateral drainage was not observed in all, supporting plausible compartmentalization of cavernous sinuses. Conclusion. Types, etiology, and duration of the CCFs may affect their drainage patterns. DSA is valuable for categorization of CCFs and verification of drainage patterns. Drainage pathways may affect the clinic presentation and also change treatment approach. PMID:24967298

  14. Pattern Recognition in Pharmacokinetic Data Analysis.

    PubMed

    Gabrielsson, Johan; Meibohm, Bernd; Weiner, Daniel

    2016-01-01

    Pattern recognition is a key element in pharmacokinetic data analyses when first selecting a model to be regressed to data. We call this process going from data to insight and it is an important aspect of exploratory data analysis (EDA). But there are very few formal ways or strategies that scientists typically use when the experiment has been done and data collected. This report deals with identifying the properties of a kinetic model by dissecting the pattern that concentration-time data reveal. Pattern recognition is a pivotal activity when modeling kinetic data, because a rigorous strategy is essential for dissecting the determinants behind concentration-time courses. First, we extend a commonly used relationship for calculation of the number of potential model parameters by simultaneously utilizing all concentration-time courses. Then, a set of points to consider are proposed that specifically addresses exploratory data analyses, number of phases in the concentration-time course, baseline behavior, time delays, peak shifts with increasing doses, flip-flop phenomena, saturation, and other potential nonlinearities that an experienced eye catches in the data. Finally, we set up a series of equations related to the patterns. In other words, we look at what causes the shapes that make up the concentration-time course and propose a strategy to construct a model. By practicing pattern recognition, one can significantly improve the quality and timeliness of data analysis and model building. A consequence of this is a better understanding of the complete concentration-time profile.

  15. Multifrequency control of Faraday wave patterns.

    PubMed

    Topaz, Chad M; Porter, Jeff; Silber, Mary

    2004-12-01

    We show how pattern formation in Faraday waves may be manipulated by varying the harmonic content of the periodic forcing function. Our approach relies on the crucial influence of resonant triad interactions coupling pairs of critical standing wave modes with damped, spatiotemporally resonant modes. Under the assumption of weak damping and forcing, we perform a symmetry-based analysis that reveals the damped modes most relevant for pattern selection, and how the strength of the corresponding triad interactions depends on the forcing frequencies, amplitudes, and phases. In many cases, the further assumption of Hamiltonian structure in the inviscid limit determines whether the given triad interaction has an enhancing or suppressing effect on related patterns. Surprisingly, even for forcing functions with arbitrarily many frequency components, there are at most five frequencies that affect each of the important triad interactions at leading order. The relative phases of those forcing components play a key role, sometimes making the difference between an enhancing and suppressing effect. In numerical examples, we examine the validity of our results for larger values of the damping and forcing. Finally, we apply our findings to one-dimensional periodic patterns obtained with impulsive forcing and to two-dimensional superlattice patterns and quasipatterns obtained with multifrequency forcing.

  16. Dermatoglyphic Patterns in Cystic Fibrosis Children

    PubMed Central

    Ezzati, Atefeh; Batoei, Fereshteh; Jafari, Seyed-Ali; Kiyani, Mohammad-Ali; Mahdavi-Shahri, Naser; Ahanchian, Hamid; Tehranian, Shahrzad; Kianifar, Hamid-Reza

    2014-01-01

    Objective: It is believed that fingerprints and palm patterns may represent genetically determined congenital abnormalities in Cystic Fibrosis (CF). The main idea of this paper was to determine differences of fingerprints and palm patterns in CF and normal children. Methods: Forty-six CF children (27 males, 19 females) and 341 (113 males, 228 females) healthy individuals were recruited for this study. Fingerprint patterns, Total ridge count (TRC) of each finger, a-b ridge count, and atd angles of all participants were recorded. Asymmetry of the right and left hand for each value was determined and dissimilarity in fingerprint patterns between homologous fingers was compared using Chi-square analysis, Mann-Whitney U test and Fisher's exact test. Findings: There were significant differences in the mean TRC of the right digit IV (P=0.009), left digit III (P=0.02), left digit IV (P=0.03), and left digit V (P=0.03). Furthermore, we found significant differences in right atd angel (P=0.001), left atd angel (P=0.002), right a-b ridge (P=0.007) and left a-b ridge (P=0.001). In contrast, we found no significant differences in atd angle asymmetry, a-b ridge count asymmetry and pattern dissimilarity score between both groups (P>0.05). Conclusion: Dermatoglyphic characteristics could be used as a supplementary diagnostic method in CF children. PMID:25793070

  17. Protein patterns as endpoints in environmental remediation

    SciTech Connect

    Bradley, B.; Brown, D.

    1995-12-31

    Biological endpoints can complement chemical analyses in monitoring environmental remediation. In some cases the levels of chemical detection are so low that the costs of clean-up to no detection would be prohibitive. And chemical tests do not indicate the availability of the contaminants to the biota. On the other hand many if not most biological tests lack specificity. The authors have investigated a protein expression assay to establish an endpoint for clean-up of sulfur mustard and breakdown products. Earthworms (Lumbricus terrestris) were exposed to sulfur mustard (SM), a breakdown product thiodiethanol (TDE), and ethylene glycol, the solvent for the two chemicals. Tissue from the lining of the coelomic cavity was taken from each of 6 worms in each treatment class. Soluble proteins were extracted and separated on one and two-dimensional (1D and 2D) gels. The 1 D gels showed no difference by eye but the patterns from control and solvent control worms on 2D gels differed from those of worms exposed to TDE and SM. The 1D gel data were digitized and analyzed by pattern recognition using artificial neural networks. The protein patterns under the two treatments and the two controls were learned in one set of data and successfully recognized in a second. This indicated that what was learned was useful in recognizing patterns induced by SM and TDE. Thus a possible endpoint for remediation would be the protein pattern at no effect levels of chemicals of interest.

  18. Commentary on eupneic breathing patterns and gasping.

    PubMed

    Richter, Diethelm W

    2003-12-16

    The term "eupneic activity pattern" is a trivial phenotypical description of a particular activity pattern in respiratory nerves as recorded under in vivo like experimental conditions. This term is, however, inadequate, because Eupnea describes a behavioral breathing performance that is trouble-free occurring without conscious effort. Obviously, the term "eupneic activity pattern" is meant to describe a neural activity that is normal and comparable with quiet breathing conditions. The various in vivo, in situ and in vitro preparations all generate their specific "normal" activity patterns, when the conditions are undisturbed. The commentary describes some of the numerous reasons why such normal activity patterns must be different in the various preparations without indicating their pathological operation. The conclusion is that special considerations are necessary for any extension of the in vitro and in situ findings into in vivo situations, because the capacity of the respiratory network is greatly reduced and thus not comparable with conditions leading to "eupneic breathing" in the fully intact animal.

  19. Humoral pattern recognition and the complement system.

    PubMed

    Degn, S E; Thiel, S

    2013-08-01

    In the context of immunity, pattern recognition is the art of discriminating friend from foe and innocuous from noxious. The basis of discrimination is the existence of evolutionarily conserved patterns on microorganisms, which are intrinsic to these microorganisms and necessary for their function and existence. Such immutable or slowly evolving patterns are ideal handles for recognition and have been targeted by early cellular immune defence mechanisms such as Toll-like receptors, NOD-like receptors, RIG-I-like receptors, C-type lectin receptors and by humoral defence mechanisms such as the complement system. Complement is a proteolytic cascade system comprising around 35 different soluble and membrane-bound proteins. It constitutes a central part of the innate immune system, mediating several major innate effector functions and modulating adaptive immune responses. The complement cascade proceeds via controlled, limited proteolysis and conformational changes of constituent proteins through three activation pathways: the classical pathway, the alternative pathway and the lectin pathway, which converge in common effector functions. Here, we review the nature of the pattern recognition molecules involved in complement activation, as well as their close relatives with no or unknown capacity for activating complement. We proceed to examine the composition of the pattern recognition complexes involved in complement activation, focusing on those of the lectin pathway, and arrive at a new model for their mechanism of operation, supported by recently emerging evidence.

  20. Metal hierarchical patterning by direct nanoimprint lithography

    PubMed Central

    Radha, Boya; Lim, Su Hui; Saifullah, Mohammad S. M.; Kulkarni, Giridhar U.

    2013-01-01

    Three-dimensional hierarchical patterning of metals is of paramount importance in diverse fields involving photonics, controlling surface wettability and wearable electronics. Conventionally, this type of structuring is tedious and usually involves layer-by-layer lithographic patterning. Here, we describe a simple process of direct nanoimprint lithography using palladium benzylthiolate, a versatile metal-organic ink, which not only leads to the formation of hierarchical patterns but also is amenable to layer-by-layer stacking of the metal over large areas. The key to achieving such multi-faceted patterning is hysteretic melting of ink, enabling its shaping. It undergoes transformation to metallic palladium under gentle thermal conditions without affecting the integrity of the hierarchical patterns on micro- as well as nanoscale. A metallic rice leaf structure showing anisotropic wetting behavior and woodpile-like structures were thus fabricated. Furthermore, this method is extendable for transferring imprinted structures to a flexible substrate to make them robust enough to sustain numerous bending cycles. PMID:23446801

  1. Visual pattern memory without shape recognition.

    PubMed

    Dill, M; Heisenberg, M

    1995-08-29

    Visual pattern memory of Drosophila melanogaster at the torque meter is investigated by a new learning paradigm called novelty choice. In this procedure the fly is first exposed to four identical patterns presented at the wall of the cylinder surrounding it. In the test it has the choice between two pairs of patterns, a new one and one the same as the training pattern. Flies show a lasting preference for the new figure. Figures presented during training are not recognized as familiar in the test, if displayed (i) at a different height, (ii) at a different size, (iii) rotated or (iv) after contrast reversal. No special invariance mechanisms are found. A pixel-by-pixel matching process is sufficient to explain the observed data. Minor transfer effects can be explained if a graded similarity function is assumed. Recognition depends upon the overlap between the stored template and the actual image. The similarity function is best described by the ratio of the area of overlap to the area of the actual image. The similarity function is independent of the geometrical properties of the employed figures. Visual pattern memory at this basic level does not require the analysis of shape. PMID:8668723

  2. Female pattern hair loss: Current treatment concepts

    PubMed Central

    Dinh, Quan Q; Sinclair, Rodney

    2007-01-01

    Fewer than 45% of women go through life with a full head of hair. Female pattern hair loss is the commonest cause of hair loss in women and prevalence increases with advancing age. Affected women may experience psychological distress and impaired social functioning. In most cases the diagnosis can be made clinically and the condition treated medically. While many women using oral antiandrogens and topical minoxidil will regrow some hair, early diagnosis and initiation of treatment is desirable as these treatments are more effective at arresting progression of hair loss than stimulating regrowth. Adjunctive nonpharmacological treatment modalities such as counseling, cosmetic camouflage and hair transplantation are important measures for some patients. The histology of female pattern hair loss is identical to that of male androgenetic alopecia. While the clinical pattern of the hair loss differs between men, the response to oral antiandrogens suggests that female pattern hair loss is an androgen dependant condition, at least in the majority of cases. Female pattern hair loss is a chronic progressive condition. All treatments need to be continued to maintain the effect. An initial therapeutic response often takes 12 or even 24 months. Given this delay, monitoring for treatment effect through clinical photography or standardized clinical severity scales is helpful. PMID:18044135

  3. Enhancing dropwise condensation through bioinspired wettability patterning.

    PubMed

    Ghosh, Aritra; Beaini, Sara; Zhang, Bong June; Ganguly, Ranjan; Megaridis, Constantine M

    2014-11-01

    Dropwise condensation (DWC) heat transfer depends strongly on the maximum diameter (Dmax) of condensate droplets departing from the condenser surface. This study presents a facile technique implemented to gain control of Dmax in DWC within vapor/air atmospheres. We demonstrate how this approach can enhance the corresponding heat transfer rate by harnessing the capillary forces in the removal of the condensate from the surface. We examine various hydrophilic-superhydrophilic patterns, which, respectively, sustain and combine DWC and filmwise condensation on the substrate. The material system uses laser-patterned masking and chemical etching to achieve the desired wettability contrast and does not employ any hydrophobizing agent. By applying alternating straight parallel strips of hydrophilic (contact angle ∼78°) mirror-finish aluminum and superhydrophilic regions (etched aluminum) on the condensing surface, we show that the average maximum droplet size on the less-wettable domains is nearly 42% of the width of the corresponding strips. An overall improvement in the condensate collection rate, up to 19% (as compared to the control case of DWC on mirror-finish aluminum) was achieved by using an interdigitated superhydrophilic track pattern (on the mirror-finish hydrophilic surface) inspired by the vein network of plant leaves. The bioinspired interdigitated pattern is found to outperform the straight hydrophilic-superhydrophilic pattern design, particularly under higher humidity conditions in the presence of noncondensable gases (NCG), a condition that is more challenging for maintaining sustained DWC. PMID:25295388

  4. Algorithm for dynamic Speckle pattern processing

    NASA Astrophysics Data System (ADS)

    Cariñe, J.; Guzmán, R.; Torres-Ruiz, F. A.

    2016-07-01

    In this paper we present a new algorithm for determining surface activity by processing speckle pattern images recorded with a CCD camera. Surface activity can be produced by motility or small displacements among other causes, and is manifested as a change in the pattern recorded in the camera with reference to a static background pattern. This intensity variation is considered to be a small perturbation compared with the mean intensity. Based on a perturbative method we obtain an equation with which we can infer information about the dynamic behavior of the surface that generates the speckle pattern. We define an activity index based on our algorithm that can be easily compared with the outcomes from other algorithms. It is shown experimentally that this index evolves in time in the same way as the Inertia Moment method, however our algorithm is based on direct processing of speckle patterns without the need for other kinds of post-processes (like THSP and co-occurrence matrix), making it a viable real-time method. We also show how this algorithm compares with several other algorithms when applied to calibration experiments. From these results we conclude that our algorithm offer qualitative and quantitative advantages over current methods.

  5. Automatically generating extraction patterns from untagged text

    SciTech Connect

    Riloff, E.

    1996-12-31

    Many corpus-based natural language processing systems rely on text corpora that have been manually annotated with syntactic or semantic tags. In particular, all previous dictionary construction systems for information extraction have used an annotated training corpus or some form of annotated input. We have developed a system called AutoSlog-TS that creates dictionaries of extraction patterns using only untagged text. AutoSlog-TS is based on the AutoSlog system, which generated extraction patterns using annotated text and a set of heuristic rules. By adapting AutoSlog and combining it with statistical techniques, we eliminated its dependency on tagged text. In experiments with the MUC-4 terrorism domain, AutoSlog-TS created a dictionary of extraction patterns that performed comparably to a dictionary created by AutoSlog, using only preclassified texts as input.

  6. Enhanced patterning by tilted ion implantation

    NASA Astrophysics Data System (ADS)

    Kim, Sang Wan; Zheng, Peng; Kato, Kimihiko; Rubin, Leonard; Liu, Tsu-Jae King

    2016-03-01

    Tilted ion implantation (TII) is proposed as a lower-cost alternative to self-aligned double patterning (SADP) for pitch halving. This new approach is based on an enhancement in etch rate of a hard-mask layer by implant-induced damage. Ar+ implantation into a thin layer of silicon dioxide (SiO2) is shown to enhance its etch rate in dilute hydrofluoric acid (HF) solution, by up to 9× for an implant dose of 3×1014 cm-2. The formation of sub-lithographic features defined by masked tilted Ar+ implantation into a SiO2 hard-mask layer is experimentally demonstrated. Features with sizes as small as ~21 nm, self-aligned to the lithographically patterned mask, are achieved. As compared with SADP, enhanced patterning by TII requires far fewer and lower-cost process steps and hence is expected to be much more cost-effective.

  7. "Anticipated" nucleosome positioning pattern in prokaryotes.

    PubMed

    Rapoport, Alexandra E; Trifonov, Edward N

    2011-11-15

    Linguistic (word count) analysis of prokaryotic genome sequences, by Shannon N-gram extension, reveals that the dominant hidden motifs in A+T rich genomes are T(A)(T)A and G(A)(T)C with uncertain number of repeating A and T. Since prokaryotic sequences are largely protein-coding, the motifs would correspond to amphipathic alpha-helices with alternating lysine and phenylalanine as preferential polar and non-polar residues. The motifs are also known in eukaryotes, as nucleosome positioning patterns. Their existence in prokaryotes as well may serve for binding of histone-like proteins to DNA. In this case the above patterns in prokaryotes may be considered as "anticipated" nucleosome positioning patterns which, quite likely, existed in prokaryotic genomes before the evolutionary separation between eukaryotes and prokaryotes.

  8. Pattern formation, logistics, and maximum path probability

    NASA Astrophysics Data System (ADS)

    Kirkaldy, J. S.

    1985-05-01

    The concept of pattern formation, which to current researchers is a synonym for self-organization, carries the connotation of deductive logic together with the process of spontaneous inference. Defining a pattern as an equivalence relation on a set of thermodynamic objects, we establish that a large class of irreversible pattern-forming systems, evolving along idealized quasisteady paths, approaches the stable steady state as a mapping upon the formal deductive imperatives of a propositional function calculus. In the preamble the classical reversible thermodynamics of composite systems is analyzed as an externally manipulated system of space partitioning and classification based on ideal enclosures and diaphragms. The diaphragms have discrete classification capabilities which are designated in relation to conserved quantities by descriptors such as impervious, diathermal, and adiabatic. Differentiability in the continuum thermodynamic calculus is invoked as equivalent to analyticity and consistency in the underlying class or sentential calculus. The seat of inference, however, rests with the thermodynamicist. In the transition to an irreversible pattern-forming system the defined nature of the composite reservoirs remains, but a given diaphragm is replaced by a pattern-forming system which by its nature is a spontaneously evolving volume partitioner and classifier of invariants. The seat of volition or inference for the classification system is thus transferred from the experimenter or theoretician to the diaphragm, and with it the full deductive facility. The equivalence relations or partitions associated with the emerging patterns may thus be associated with theorems of the natural pattern-forming calculus. The entropy function, together with its derivatives, is the vehicle which relates the logistics of reservoirs and diaphragms to the analog logistics of the continuum. Maximum path probability or second-order differentiability of the entropy in isolation are

  9. Face recognition based on fringe pattern analysis

    NASA Astrophysics Data System (ADS)

    Guo, Hong; Huang, Peisen

    2010-03-01

    Two-dimensional face-recognition techniques suffer from facial texture and illumination variations. Although 3-D techniques can overcome these limitations, the reconstruction and storage expenses of 3-D information are extremely high. We present a novel face-recognition method that directly utilizes 3-D information encoded in face fringe patterns without having to reconstruct 3-D geometry. In the proposed method, a digital video projector is employed to sequentially project three phase-shifted sinusoidal fringe patterns onto the subject's face. Meanwhile, a camera is used to capture the distorted fringe patterns from an offset angle. Afterward, the face fringe images are analyzed by the phase-shifting method and the Fourier transform method to obtain a spectral representation of the 3-D face. Finally, the eigenface algorithm is applied to the face-spectrum images to perform face recognition. Simulation and experimental results demonstrate that the proposed method achieved satisfactory recognition rates with reduced computational complexity and storage expenses.

  10. Stochasticity in plant cellular growth and patterning

    PubMed Central

    Meyer, Heather M.; Roeder, Adrienne H. K.

    2014-01-01

    Plants, along with other multicellular organisms, have evolved specialized regulatory mechanisms to achieve proper tissue growth and morphogenesis. During development, growing tissues generate specialized cell types and complex patterns necessary for establishing the function of the organ. Tissue growth is a tightly regulated process that yields highly reproducible outcomes. Nevertheless, the underlying cellular and molecular behaviors are often stochastic. Thus, how does stochasticity, together with strict genetic regulation, give rise to reproducible tissue development? This review draws examples from plants as well as other systems to explore stochasticity in plant cell division, growth, and patterning. We conclude that stochasticity is often needed to create small differences between identical cells, which are amplified and stabilized by genetic and mechanical feedback loops to begin cell differentiation. These first few differentiating cells initiate traditional patterning mechanisms to ensure regular development. PMID:25250034

  11. Periodic Patterns in Distributions of Peptide Masses

    PubMed Central

    Hubler, Shane L.; Craciun, Gheorghe

    2015-01-01

    We are investigating the distribution of the number of peptides for given masses, and especially the observation that peptide density reaches a local maximum approximately every 14 Daltons. This wave pattern exists across species (e.g. human or yeast) and enzyme digestion techniques. To analyze this phenomenon we have developed a mathematical method for computing the mass distributions of peptides, and we present both theoretical and empirical evidence that this 14-Dalton periodicity does not arise from species selection of peptides but from the number-theoretic properties of the masses of amino acid residues. We also describe other, more subtle periodic patterns in the distribution of peptide masses. We also show that these periodic patterns are robust under a variety of conditions, including the addition of amino acid modifications and selection of mass accuracy scale. The method used here is also applicable to any family of sequential molecules, such as linear hydrocarbons, RNA, single- and double-stranded DNA. PMID:22579741

  12. Periodic patterns in distributions of peptide masses.

    PubMed

    Hubler, Shane L; Craciun, Gheorghe

    2012-08-01

    We are investigating the distribution of the number of peptides for given masses, and especially the observation that peptide density reaches a local maximum approximately every 14Da. This wave pattern exists across species (e.g. human or yeast) and enzyme digestion techniques. To analyze this phenomenon we have developed a mathematical method for computing the mass distributions of peptides, and we present both theoretical and empirical evidence that this 14-Da periodicity does not arise from species selection of peptides but from the number- theoretic properties of the masses of amino acid residues. We also describe other, more subtle periodic patterns in the distribution of peptide masses. We also show that these periodic patterns are robust under a variety of conditions, including the addition of amino acid modifications and selection of mass accuracy scale. The method used here is also applicable to any family of sequential molecules, such as linear hydrocarbons, RNA, single- and double-stranded DNA.

  13. The Early Repolarization Pattern: A Consensus Paper.

    PubMed

    Macfarlane, Peter W; Antzelevitch, Charles; Haissaguerre, Michel; Huikuri, Heikki V; Potse, Mark; Rosso, Raphael; Sacher, Frederic; Tikkanen, Jani T; Wellens, Hein; Yan, Gan-Xin

    2015-07-28

    The term early repolarization has been in use for more than 50 years. This electrocardiographic pattern was considered benign until 2008, when it was linked to sudden cardiac arrest due to idiopathic ventricular fibrillation. Much confusion over the definition of early repolarization followed. Thus, the objective of this paper was to prepare an agreed definition to facilitate future research in this area. The different definitions of the early repolarization pattern were reviewed to delineate the electrocardiographic measures to be used when defining this pattern. An agreed definition has been established, which requires the peak of an end-QRS notch and/or the onset of an end-QRS slur as a measure, denoted Jp, to be determined when an interpretation of early repolarization is being considered. One condition for early repolarization to be present is Jp ≥0.1 mV, while ST-segment elevation is not a required criterion.

  14. Ultrasmooth patterned metals for plasmonics and metamaterials.

    PubMed

    Nagpal, Prashant; Lindquist, Nathan C; Oh, Sang-Hyun; Norris, David J

    2009-07-31

    Surface plasmons are electromagnetic waves that can exist at metal interfaces because of coupling between light and free electrons. Restricted to travel along the interface, these waves can be channeled, concentrated, or otherwise manipulated by surface patterning. However, because surface roughness and other inhomogeneities have so far limited surface-plasmon propagation in real plasmonic devices, simple high-throughput methods are needed to fabricate high-quality patterned metals. We combined template stripping with precisely patterned silicon substrates to obtain ultrasmooth pure metal films with grooves, bumps, pyramids, ridges, and holes. Measured surface-plasmon-propagation lengths on the resulting surfaces approach theoretical values for perfectly flat films. With the use of our method, we demonstrated structures that exhibit Raman scattering enhancements above 10(7) for sensing applications and multilayer films for optical metamaterials.

  15. Symptom Patterns Among Gulf War Registry Veterans

    PubMed Central

    Hallman, William K.; Kipen, Howard M.; Diefenbach, Michael; Boyd, Kendal; Kang, Han; Leventhal, Howard; Wartenberg, Daniel

    2003-01-01

    Objectives. We identify symptom patterns among veterans who believe they suffer from Gulf War–related illnesses and characterize groups of individuals with similar patterns. Methods. A mail survey was completed by 1161 veterans drawn from the Gulf War Health Registry. Results. An exploratory factor analysis revealed 4 symptom factors. A K-means cluster analysis revealed 2 groups: (1) veterans reporting good health and few moderate/severe symptoms, and (2) veterans reporting fair/poor health and endorsing an average of 37 symptoms, 75% as moderate/severe. Those in Cluster 2 were more likely to report having 1 or more of 24 medical conditions. Conclusions. These findings are consistent with previous investigations of symptom patterns in Gulf War veterans. This multisymptom illness may be more fully characterized by the extent, breadth, and severity of symptoms reported. PMID:12660208

  16. Mating ecology explains patterns of genome elimination

    PubMed Central

    Gardner, Andy; Ross, Laura

    2014-01-01

    Genome elimination – whereby an individual discards chromosomes inherited from one parent, and transmits only those inherited from the other parent – is found across thousands of animal species. It is more common in association with inbreeding, under male heterogamety, in males, and in the form of paternal genome elimination. However, the reasons for this broad pattern remain unclear. We develop a mathematical model to determine how degree of inbreeding, sex determination, genomic location, pattern of gene expression and parental origin of the eliminated genome interact to determine the fate of genome-elimination alleles. We find that: inbreeding promotes paternal genome elimination in the heterogametic sex; this may incur population extinction under female heterogamety, owing to eradication of males; and extinction is averted under male heterogamety, owing to countervailing sex-ratio selection. Thus, we explain the observed pattern of genome elimination. Our results highlight the interaction between mating system, sex-ratio selection and intragenomic conflict. PMID:25328085

  17. Scale and Nature of Sulcification Patterns

    NASA Astrophysics Data System (ADS)

    Hohlfeld, Evan; Mahadevan, L.

    2012-07-01

    Sulci are surface folds commonly seen in strained soft elastomers and form via a strongly subcritical, yet scale-free, instability. Treating the threshold for nonlinear instability as a nonlinear critical point, we explain the nature of sulcus patterns in terms of the scale and translation symmetries which are broken by the formation of an isolated, small sulcus. Our perturbative theory and simulations show that sulcus formation in a thick, compressed slab can arise either as a supercritical or as a weakly subcritical bifurcation relative to this nonlinear critical point, depending on the boundary conditions. An infinite number of competing, equilibrium patterns simultaneously emerge at this critical point, but the one selected has the lowest energy. We give a simple, physical explanation for the formation of these sulcification patterns using an analogy to a solid-solid phase transition with a finite energy of transformation.

  18. Taming contact line instability for pattern formation

    PubMed Central

    Deblais, A.; Harich, R.; Colin, A.; Kellay, H.

    2016-01-01

    Coating surfaces with different fluids is prone to instability producing inhomogeneous films and patterns. The contact line between the coating fluid and the surface to be coated is host to different instabilities, limiting the use of a variety of coating techniques. Here we take advantage of the instability of a receding contact line towards cusp and droplet formation to produce linear patterns of variable spacings. We stabilize the instability of the cusps towards droplet formation by using polymer solutions that inhibit this secondary instability and give rise to long slender cylindrical filaments. We vary the speed of deposition to change the spacing between these filaments. The combination of the two gives rise to linear patterns into which different colloidal particles can be embedded, long DNA molecules can be stretched and particles filtered by size. The technique is therefore suitable to prepare anisotropic structures with variable properties. PMID:27506626

  19. Atomic momentum patterns with narrower intervals

    NASA Astrophysics Data System (ADS)

    Yang, Baoguo; Jin, Shengjie; Dong, Xiangyu; Liu, Zhe; Yin, Lan; Zhou, Xiaoji

    2016-10-01

    We studied the atomic momentum distribution of a superposition of Bloch states in the lowest band of an optical lattice after the action of the standing-wave pulse. By designing the imposing pulse on this superposed state, an atomic momentum pattern appears with a narrow interval between the adjacent peaks that can be far less than double recoil momentum. The patterns with narrower interval come from the effect of the designed pulse on the superposition of many Bloch states with quasimomenta throughout the first Brillouin zone. Our experimental result of narrow interval peaks is consistent with the theoretical simulation. The patterns of multiple modes with different quasimomenta may be helpful for precise measurement and atomic manipulation.

  20. Chiral patterning in Paenibacillus colonies under stress

    NASA Astrophysics Data System (ADS)

    Levine, Herbert

    2012-02-01

    One of the most striking examples of bacterial colony patterning occurs in the C-morphotype of Paenibacillus strains. Here, macroscopic chirality results from the interaction of local liquid-crystal ordering of the long bacterial cells with the self-propelled motility driven by the non-reflection-symmetric flagella. This talk will review some of the original experimental data from the Ben-Jacob lab as well as recent insight obtained via genomics. I will then discuss attempts to model and simulate the chiral patterns via solving reaction-diffusion equations on random lattices. At the end, I will introduce the challenges still to be faced in understanding transitions between these patterns and more common branching structures