802GHz integrated horn antennas imaging array

NASA Technical Reports Server (NTRS)

Ali-Ahmad, Walid Y.; Rebeiz, Gabriel M.; Dave, Hemant; Chin, Gordon

1991-01-01

Pattern measurements at 802GHz of a single element in 256-element integrated horn imaging array are presented. The integrated-horn antenna consists of a dipole-antenna suspended on a 1-micron dielectric membrane inside a pyramidal cavity etched in silicon. The theoretical far-field patterns, calculated using reciprocity and Floquet-modes representation of the free-space field, agree well with the measured far-field patterns at 802GHz. The associated directivity for a 1.40 lambda horn aperture, calculated from the measured E and H-plane patterns is 12.3dB + or - 0.2dB. This work demonstrates that high-efficiency integrated-horn antennas are easily scalable to terahertz frequencies and could be used for radio-astronomical and plasma-diagnostic applications.

Debris Evaluation after Root Canal Shaping with Rotating and Reciprocating Single-File Systems

PubMed Central

Dagna, Alberto; Gastaldo, Giulia; Beltrami, Riccardo; Poggio, Claudio

2016-01-01

This study evaluated the root canal dentine surface by scanning electron microscope (SEM) after shaping with two reciprocating single-file NiTi systems and two rotating single-file NiTi systems, in order to verify the presence/absence of the smear layer and the presence/absence of open tubules along the walls of each sample; Forty-eight single-rooted teeth were divided into four groups and shaped with OneShape (OS), F6 SkyTaper (F6), WaveOne (WO) and Reciproc and irrigated using 5.25% NaOCl and 17% EDTA. Root canal walls were analyzed by SEM at a standard magnification of 2500×. The presence/absence of the smear layer and the presence/absence of open tubules at the coronal, middle, and apical third of each canal were estimated using a five-step scale for scores. Numeric data were analyzed using Kruskal-Wallis and Mann-Whitney U statistical tests and significance was predetermined at P < 0.05; The Kruskal-Wallis ANOVA for debris score showed significant differences among the NiTi systems (P < 0.05). The Mann-Whitney test confirmed that reciprocating systems presented significantly higher score values than rotating files. The same results were assessed considering the smear layer scores. ANOVA confirmed that the apical third of the canal maintained a higher quantity of debris and smear layer after preparation of all the samples; Single-use NiTi systems used in continuous rotation appeared to be more effective than reciprocating instruments in leaving clean walls. The reciprocating systems produced more debris and smear layer than rotating instruments. PMID:27763503

Comparison of cyclic fatigue and torsional resistance in reciprocating single-file systems and continuous rotary instrumentation systems.

PubMed

da Frota, Matheus F; Espir, Camila G; Berbert, Fábio L C V; Marques, André A F; Sponchiado-Junior, Emílio C; Tanomaru-Filho, Mario; Garcia, Lucas F R; Bonetti-Filho, Idomeo

2014-12-01

As compared with continuous rotary systems, reciprocating motion is believed to increase the fatigue resistance of NiTi instruments. We compared the cyclic fatigue and torsional resistance of reciprocating single-file systems and continuous rotary instrumentation systems in simulated root canals. Eighty instruments from the ProTaper Universal, WaveOne, MTwo, and Reciproc systems (n = 20) were submitted to dynamic bending testing in stainless-steel simulated curved canals. Axial displacement of the simulated canals was performed with half of the instruments (n = 10), with back-and-forth movements in a range of 1.5 mm. Time until fracture was recorded, and the number of cycles until instrument fracture was calculated. Cyclic fatigue resistance was greater for reciprocating systems than for rotary systems (P < 0.05). Instruments from the Reciproc and WaveOne systems significantly differed only when axial displacement occurred (P < 0.05). Instruments of the ProTaper Universal and MTwo systems did not significantly differ (P > 0.05). Cyclic fatigue and torsional resistance were greater for reciprocating systems than for continuous rotary systems, irrespective of axial displacement.

Design considerations for eye-safe single-aperture laser radars

NASA Astrophysics Data System (ADS)

Starodubov, D.; McCormick, K.; Volfson, L.

2015-05-01

The design considerations for low cost, shock resistant, compact and efficient laser radars and ranging systems are discussed. The reviewed approach with single optical aperture allows reducing the size, weight and power of the system. Additional design benefits include improved stability, reliability and rigidity of the overall system. The proposed modular architecture provides simplified way of varying the performance parameters of the range finder product family by selecting the sets of specific illumination and detection modules. The performance operation challenges are presented. The implementation of non-reciprocal optical elements is considered. The cross talk between illumination and detection channels for single aperture design is reviewed. 3D imaging capability for the ranging applications is considered. The simplified assembly and testing process for single aperture range finders that allows to mass produce the design are discussed. The eye safety of the range finder operation is summarized.

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

Jo, J.C.; Shin, W.K.; Choi, C.Y.

Transient heat transfer problems with phase changes (Stefan problems) occur in many engineering situations, including potential core melting and solidification during pressurized-water-reactor severe accidents, ablation of thermal shields, melting and solidification of alloys, and many others. This article addresses the numerical analysis of nonlinear transient heat transfer with melting or solidification. An effective and simple procedure is presented for the simulation of the motion of the boundary and the transient temperature field during the phase change process. To accomplish this purpose, an iterative implicit solution algorithm has been developed by employing the dual-reciprocity boundary-element method. The dual-reciprocity boundary-element approach providedmore » in this article is much simpler than the usual boundary-element method in applying a reciprocity principle and an available technique for dealing with the domain integral of the boundary element formulation simultaneously. In this article, attention is focused on two-dimensional melting (ablation)/solidification problems for simplicity. The accuracy and effectiveness of the present analysis method have been illustrated through comparisons of the calculation results of some examples of one-phase ablation/solidification problems with their known semianalytical or numerical solutions where available.« less

Evaluation of Apical Extrusion of Debris and Irrigant Using Two New Reciprocating and One Continuous Rotation Single File Systems

PubMed Central

Nayak, Gurudutt; Singh, Inderpreet; Shetty, Shashit; Dahiya, Surya

2014-01-01

Objective: Apical extrusion of debris and irrigants during cleaning and shaping of the root canal is one of the main causes of periapical inflammation and postoperative flare-ups. The purpose of this study was to quantitatively measure the amount of debris and irrigants extruded apically in single rooted canals using two reciprocating and one rotary single file nickel-titanium instrumentation systems. Materials and Methods: Sixty human mandibular premolars, randomly assigned to three groups (n = 20) were instrumented using two reciprocating (Reciproc and Wave One) and one rotary (One Shape) single-file nickel-titanium systems. Bidistilled water was used as irrigant with traditional needle irrigation delivery system. Eppendorf tubes were used as test apparatus for collection of debris and irrigant. The volume of extruded irrigant was collected and quantified via 0.1-mL increment measure supplied on the disposable plastic insulin syringe. The liquid inside the tubes was dried and the mean weight of debris was assessed using an electronic microbalance. The data were statistically analysed using Kruskal-Wallis nonparametric test and Mann Whitney U test with Bonferroni adjustment. P-values less than 0.05 were considered significant. Results: The Reciproc file system produced significantly more debris compared with OneShape file system (P<0.05), but no statistically significant difference was obtained between the two reciprocating instruments (P>0.05). Extrusion of irrigant was statistically insignificant irrespective of the instrument or instrumentation technique used (P >0.05). Conclusions: Although all systems caused apical extrusion of debris and irrigant, continuous rotary instrumentation was associated with less extrusion as compared with the use of reciprocating file systems. PMID:25628665

Turbofan Acoustic Propagation and Radiation

NASA Technical Reports Server (NTRS)

Eversman, Walter

2000-01-01

This document describes progress in the development of finite element codes for the prediction of near and far field acoustic radiation from the inlet and aft fan ducts of turbofan engines. The report consists of nine papers which have appeared in archival journals and conference proceedings, or are presently in review for publication. Topics included are: 1. Aft Fan Duct Acoustic Radiation; 2. Mapped Infinite Wave Envelope Elements for Acoustic Radiation in a Uniformly Moving Medium; 3. A Reflection Free Boundary Condition for Propagation in Uniform Flow Using Mapped Infinite Wave Envelope Elements; 4. A Numerical Comparison Between Multiple-Scales and FEM Solution for Sound Propagation in Lined Flow Ducts; 5. Acoustic Propagation at High Frequencies in Ducts; 6. The Boundary Condition at an Impedance Wall in a Nonuniform Duct with Potential Flow; 7. A Reverse Flow Theorem and Acoustic Reciprocity in Compressible Potential Flows; 8. Reciprocity and Acoustics Power in One Dimensional Compressible Potential Flows; and 9. Numerical Experiments on Acoustic Reciprocity in Compressible Potential Flows.

Comparison of tungsten carbide and stainless steel ball bearings for grinding single maize kernels in a reciprocating grinder

USDA-ARS?s Scientific Manuscript database

Reciprocating grinders can grind single maize kernels by shaking the kernel in a vial with a ball bearing. This process results in a grind quality that is not satisfactory for many experiments. Tungesten carbide ball bearings are nearly twice as dense as steel, so we compared their grinding performa...

Reciprocal Influence of Protein Domains in the Cold-Adapted Acyl Aminoacyl Peptidase from Sporosarcina psychrophila

PubMed Central

Parravicini, Federica; Natalello, Antonino; Papaleo, Elena; De Gioia, Luca; Doglia, Silvia Maria; Lotti, Marina; Brocca, Stefania

2013-01-01

Acyl aminoacyl peptidases are two-domain proteins composed by a C-terminal catalytic α/β-hydrolase domain and by an N-terminal β-propeller domain connected through a structural element that is at the N-terminus in sequence but participates in the 3D structure of the C-domain. We investigated about the structural and functional interplay between the two domains and the bridge structure (in this case a single helix named α1-helix) in the cold-adapted enzyme from Sporosarcina psychrophila (SpAAP) using both protein variants in which entire domains were deleted and proteins carrying substitutions in the α1-helix. We found that in this enzyme the inter-domain connection dramatically affects the stability of both the whole enzyme and the β-propeller. The α1-helix is required for the stability of the intact protein, as in other enzymes of the same family; however in this psychrophilic enzyme only, it destabilizes the isolated β-propeller. A single charged residue (E10) in the α1-helix plays a major role for the stability of the whole structure. Overall, a strict interaction of the SpAAP domains seems to be mandatory for the preservation of their reciprocal structural integrity and may witness their co-evolution. PMID:23457536

Reciprocal influence of protein domains in the cold-adapted acyl aminoacyl peptidase from Sporosarcina psychrophila.

PubMed

Parravicini, Federica; Natalello, Antonino; Papaleo, Elena; De Gioia, Luca; Doglia, Silvia Maria; Lotti, Marina; Brocca, Stefania

2013-01-01

Acyl aminoacyl peptidases are two-domain proteins composed by a C-terminal catalytic α/β-hydrolase domain and by an N-terminal β-propeller domain connected through a structural element that is at the N-terminus in sequence but participates in the 3D structure of the C-domain. We investigated about the structural and functional interplay between the two domains and the bridge structure (in this case a single helix named α1-helix) in the cold-adapted enzyme from Sporosarcina psychrophila (SpAAP) using both protein variants in which entire domains were deleted and proteins carrying substitutions in the α1-helix. We found that in this enzyme the inter-domain connection dramatically affects the stability of both the whole enzyme and the β-propeller. The α1-helix is required for the stability of the intact protein, as in other enzymes of the same family; however in this psychrophilic enzyme only, it destabilizes the isolated β-propeller. A single charged residue (E10) in the α1-helix plays a major role for the stability of the whole structure. Overall, a strict interaction of the SpAAP domains seems to be mandatory for the preservation of their reciprocal structural integrity and may witness their co-evolution.

Collaborative Strategic Reading (CSR): Improving Secondary Students' Reading Comprehension Skills. Research to Practice Brief: Improving Secondary Education and Transition Services through Research.

ERIC Educational Resources Information Center

Bremer, Christine D.; Vaughn, Sharon; Clapper, Ann T.; Kim, Ae-Hwa

This brief introduces a research-based practice, Collaborative Strategic Reading (CSR). This reading comprehension practice, designed to improve secondary students reading comprehension skills, combines two instructional elements: modified reciprocal teaching and cooperative learning or student pairing. In reciprocal teaching, teachers and…

Integration of neutron time-of-flight single-crystal Bragg peaks in reciprocal space

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

Schultz, Arthur J; Joergensen, Mads; Wang, Xiaoping

2014-01-01

The intensity of single crystal Bragg peaks obtained by mapping neutron time-of-flight event data into reciprocal space and integrating in various ways are compared. These include spherical integration with a fixed radius, ellipsoid fitting and integrating of the peak intensity and one-dimensional peak profile fitting. In comparison to intensities obtained by integrating in real detector histogram space, the data integrated in reciprocal space results in better agreement factors and more accurate atomic parameters. Furthermore, structure refinement using integrated intensities from one-dimensional profile fitting is demonstrated to be more accurate than simple peak-minus-background integration.

Hydraulic flow visualization method and apparatus

DOEpatents

Karidis, Peter G.

1984-01-01

An apparatus and method for visualizing liquid flow. Pulses of gas bubbles are introduced into a liquid flow stream and a strobe light is operated at a frequency related to the frequency of the gas pulses to shine on the bubbles as they pass through the liquid stream. The gas pulses pass through a probe body having a valve element, and a reciprocating valve stem passes through the probe body to operate the valve element. A stem actuating device comprises a slidable reciprocating member, operated by a crank arm. The actuated member is adjustable to adjust the amount of the valve opening during each pulse.

"Dentinal microcracks after root canal preparation" a comparative evaluation with hand, rotary and reciprocating instrumentation.

PubMed

Priya, N Tulasi; Chandrasekhar, Veeramachaneni; Anita, S; Tummala, Muralidhar; Raj, T B Phanindhar; Badami, Vijetha; Kumar, Pradeep; Soujanya, E

2014-12-01

The purpose of this study was to compare the incidence of dentinal micro cracks after instrumentation with various types of NiTi files in rotary and reciprocating motion. One hundred human extracted mandibular central incisors were taken and divided into 10 groups (n=10 teeth per group). Group 1- No preparation, Group 2 - Hand instrumentation, Groups 3,4 - ProTaper files in rotary and reciprocating motion, Groups 5,6 - ProTaper Next files in rotary and reciprocating motion, Groups 7,8 - Oneshape files in rotary and reciprocating motion, Groups 9,10 - Reciproc files in rotary and reciprocating motion. Specimens were sectioned horizontally at 3,6 and 9 mm from the apex and dentinal micro cracks were observed under a stereomicroscope. There was a statistically significant difference between the groups (p<0.05). There were no significant differences in crack formation between the groups (Protaper Next - Rot, Protaper Next - Rec, Reciproc - Rec); (ProTaper - Rot, ProTaper - Rec, Oneshape - Rot), (Oneshape - Rot, Reciproc - Rot), (One shape Reciproc, Reciproc - Rec); (p >.05). Least cracks were seen in canals instrumented with Pro Taper Next files both in rotary and reciprocating motion. Full sequence rotary systems showed less cracks than single file systems and full sequence rotary systems showed less cracks in reciprocating motion than in rotary motion.

Reciprocal uniparental disomy in yeast.

PubMed

Andersen, Sabrina L; Petes, Thomas D

2012-06-19

In the diploid cells of most organisms, including humans, each chromosome is usually distinguishable from its partner homolog by multiple single-nucleotide polymorphisms. One common type of genetic alteration observed in tumor cells is uniparental disomy (UPD), in which a pair of homologous chromosomes are derived from a single parent, resulting in loss of heterozygosity for all single-nucleotide polymorphisms while maintaining diploidy. Somatic UPD events are usually explained as reflecting two consecutive nondisjunction events. Here we report a previously undescribed mode of chromosome segregation in Saccharomyces cerevisiae in which one cell division produces daughter cells with reciprocal UPD for the same pair of chromosomes without an aneuploid intermediate. One pair of sister chromatids is segregated into one daughter cell and the other pair is segregated into the other daughter cell, mimicking a meiotic chromosome segregation pattern. We term this process "reciprocal uniparental disomy."

Endodontic retreatment: clinical comparison of reciprocating systems versus rotary system in disinfecting root canals.

PubMed

Martinho, Frederico C; Freitas, Lilian F; Nascimento, Gustavo G; Fernandes, Aleteia M; Leite, Fabio R M; Gomes, Ana P M; Camões, Izabel C G

2015-07-01

This clinical study was conducted to compare the effectiveness of single-file reciprocating systems and rotary systems in removing endotoxins and cultivable bacteria in endodontic retreatment. Thirty endodontically treated teeth with post-treatment apical periodontitis were selected. The specimens were divided into three groups according to the system used: WaveOne (n = 10), Reciproc instrument (n = 10), and ProTaper Universal Retreatment system (n = 10). Samples were collected before and after chemomechanical preparation. The irrigation was performed by using 2.5% sodium hypochlorite. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins. Culture techniques were used to determine bacterial colony-forming unit counts. At baseline, endotoxins and cultivable bacteria were recovered from 100% of the root canal samples in a median value of 5.84 EU/mL and 4.98 × 10(3) CFU/mL, respectively. After CMP, no differences were found in the median percentage values of endotoxin reduction achieved with reciprocating systems-WaveOne [94.11%] and Reciproc [93.29%] and with rotary systems-ProTaper [94.98%] (P > 0.05). Both single-file reciprocating systems [WaveOne (98.27%) and Reciproc (99.54%)] and rotary system [ProTaper (98.73%)] were effective in reducing bacterial load (P > 0.05). Moreover, no differences were found among the systems tested. The Reciproc and WaveOne reciprocating systems were as effective as the ProTaper system for removal of endotoxins and bacteria in endodontic retreatment. All systems tested were effective to remove cultivable bacteria and endotoxin in endodontic retreatment. As no differences among systems were observed, it is possible to suggest that clinicians should choose the preferred technique to perform endodontic.

Reciprocal and Complementary Sibling Interactions: Relations with Socialization Outcomes in the Kindergarten Classroom

PubMed Central

Harrist, Amanda W.; Achacoso, Joseph A.; John, Aesha; Pettit, Gregory S.; Bates, John E.; Dodge, Kenneth A.

2013-01-01

Research Findings To examine associations between sibling interaction patterns and later social outcomes in single- and two-parent families, 113 kindergarteners took part in naturalistic observations at home with siblings, classmates participated in sociometric interviews, and teachers completed behavior ratings. Sibling interactions were coded using a newly-developed 39-item checklist, and proportions of complementary and reciprocal sibling interactions computed. Complementarity occurred more among dyads where kindergartners were with toddler or infant siblings than among kindergartners with older or near-age younger siblings. Higher levels of complementarity predicted lower levels of internalizing but were not related to externalizing problems. Kindergartners’ sociometric status in the classroom differed as a function of sibling interaction patterns, with neglected and controversial children experiencing less complementarity/more reciprocity than popular, average, and rejected children. Finally, there was some evidence for differential associations of sibling interaction patterns with social outcomes for children in single- versus two-parent families: regressions testing interaction effects show sibling reciprocity positively associated with kindergartners’ social skills only in single-parent families, and complementary sibling interactions positively related to internalizing problems only in two-parent families. Implications for Practice Those working with divorcing or other single-parent families might consider sibling interactions as a potential target for social skill building. PMID:26005311

Effects of propranolol on conversational reciprocity in autism spectrum disorder: a pilot, double-blind, single-dose psychopharmacological challenge study.

PubMed

Zamzow, Rachel M; Ferguson, Bradley J; Stichter, Janine P; Porges, Eric C; Ragsdale, Alexandra S; Lewis, Morgan L; Beversdorf, David Q

2016-04-01

Pharmacological intervention for autism spectrum disorder (ASD) is an important addition to treatment, yet currently available agents target co-morbid psychiatric concerns, such as aggression and irritability. Propranolol, a beta-adrenergic antagonist with anxiolytic effects, has been shown to improve verbal fluency and working memory in adults and adolescents with ASD in single-dose challenges. The present pilot study explores the acute effects of propranolol on a measure of conversational reciprocity in this population. We also examined whether autonomic activity and anxiety moderate or mediate response to the drug, given relationships between these variables and ASD, as well as the drug's effects. In a within-subject crossover design, 20 individuals with ASD received a single dose of propranolol or placebo during two sessions in a double-blinded, counterbalanced manner. After drug administration, participants performed a conversational reciprocity task by engaging in a short conversation with the researcher. Measurements of autonomic activity and anxiety were obtained before and after drug administration. Propranolol significantly improved performance on the conversational reciprocity task total [d = 0.40] and nonverbal communication domain scores when compared to the placebo condition. However, neither autonomic activity nor anxiety was significantly associated with drug response. Acute propranolol administration improved conversational reciprocity in ASD. Further exploration of these preliminary findings, as well as other potential treatment response predictors, with serial doses is warranted.

Identification of misexpressed genetic elements in hybrids between Drosophila-related species.

PubMed

Lopez-Maestre, Hélène; Carnelossi, Elias A G; Lacroix, Vincent; Burlet, Nelly; Mugat, Bruno; Chambeyron, Séverine; Carareto, Claudia M A; Vieira, Cristina

2017-01-16

Crosses between close species can lead to genomic disorders, often considered to be the cause of hybrid incompatibility, one of the initial steps in the speciation process. How these incompatibilities are established and what are their causes remain unclear. To understand the initiation of hybrid incompatibility, we performed reciprocal crosses between two species of Drosophila (D. mojavensis and D. arizonae) that diverged less than 1 Mya. We performed a genome-wide transcriptomic analysis on ovaries from parental lines and on hybrids from reciprocal crosses. Using an innovative procedure of co-assembling transcriptomes, we show that parental lines differ in the expression of their genes and transposable elements. Reciprocal hybrids presented specific gene categories and few transposable element families misexpressed relative to the parental lines. Because TEs are mainly silenced by piwi-interacting RNAs (piRNAs), we hypothesize that in hybrids the deregulation of specific TE families is due to the absence of such small RNAs. Small RNA sequencing confirmed our hypothesis and we therefore propose that TEs can indeed be major players of genome differentiation and be implicated in the first steps of genomic incompatibilities through small RNA regulation.

Identification of misexpressed genetic elements in hybrids between Drosophila-related species

PubMed Central

Lopez-Maestre, Hélène; Carnelossi, Elias A. G.; Lacroix, Vincent; Burlet, Nelly; Mugat, Bruno; Chambeyron, Séverine; Carareto, Claudia M. A.; Vieira, Cristina

2017-01-01

Crosses between close species can lead to genomic disorders, often considered to be the cause of hybrid incompatibility, one of the initial steps in the speciation process. How these incompatibilities are established and what are their causes remain unclear. To understand the initiation of hybrid incompatibility, we performed reciprocal crosses between two species of Drosophila (D. mojavensis and D. arizonae) that diverged less than 1 Mya. We performed a genome-wide transcriptomic analysis on ovaries from parental lines and on hybrids from reciprocal crosses. Using an innovative procedure of co-assembling transcriptomes, we show that parental lines differ in the expression of their genes and transposable elements. Reciprocal hybrids presented specific gene categories and few transposable element families misexpressed relative to the parental lines. Because TEs are mainly silenced by piwi-interacting RNAs (piRNAs), we hypothesize that in hybrids the deregulation of specific TE families is due to the absence of such small RNAs. Small RNA sequencing confirmed our hypothesis and we therefore propose that TEs can indeed be major players of genome differentiation and be implicated in the first steps of genomic incompatibilities through small RNA regulation. PMID:28091568

Endodontic Treatment of Hypertaurodontic Mandibular Molar Using Reciprocating Single-file System: A Case Report.

PubMed

C do Nascimento, Adriano; A F Marques, André; C Sponchiado-Júnior, Emílio; F R Garcia, Lucas; M A de Carvalho, Fredson

2016-01-01

Taurodontism is a developmental tooth disorder characterized by lack of constriction in the cementoenamel junction and consequent vertical stretch of the pulp chamber, accompanied by apical displacement of the pulpal floor. The endodontic treatment of teeth with this type of morpho-anatomical anomaly is challenging. The purpose of this article is to report the successful endodontic treatment of a hypertaurodontic mandibular molar using a reciprocating single-file system.

Detecting reciprocity at a global scale

PubMed Central

Frank, Morgan R.; Obradovich, Nick; Sun, Lijun; Woon, Wei Lee; LeVeck, Brad L.; Rahwan, Iyad

2018-01-01

Reciprocity stabilizes cooperation from the level of microbes all the way up to humans interacting in small groups, but does reciprocity also underlie stable cooperation between larger human agglomerations, such as nation states? Famously, evolutionary models show that reciprocity could emerge as a widespread strategy for achieving international cooperation. However, existing studies have only detected reciprocity-driven cooperation in a small number of country pairs. We apply a new method for detecting mutual influence in dynamical systems to a new large-scale data set that records state interactions with high temporal resolution. Doing so, we detect reciprocity between many country pairs in the international system and find that these reciprocating country pairs exhibit qualitatively different cooperative dynamics when compared to nonreciprocating pairs. Consistent with evolutionary theories of cooperation, reciprocating country pairs exhibit higher levels of stable cooperation and are more likely to punish instances of noncooperation. However, countries in reciprocity-based relationships are also quicker to forgive single acts of noncooperation by eventually returning to previous levels of mutual cooperation. By contrast, nonreciprocating pairs are more likely to exploit each other’s cooperation via higher rates of defection. Together, these findings provide the strongest evidence to date that reciprocity is a widespread mechanism for achieving international cooperation. PMID:29326983

Detecting reciprocity at a global scale.

PubMed

Frank, Morgan R; Obradovich, Nick; Sun, Lijun; Woon, Wei Lee; LeVeck, Brad L; Rahwan, Iyad

2018-01-01

Reciprocity stabilizes cooperation from the level of microbes all the way up to humans interacting in small groups, but does reciprocity also underlie stable cooperation between larger human agglomerations, such as nation states? Famously, evolutionary models show that reciprocity could emerge as a widespread strategy for achieving international cooperation. However, existing studies have only detected reciprocity-driven cooperation in a small number of country pairs. We apply a new method for detecting mutual influence in dynamical systems to a new large-scale data set that records state interactions with high temporal resolution. Doing so, we detect reciprocity between many country pairs in the international system and find that these reciprocating country pairs exhibit qualitatively different cooperative dynamics when compared to nonreciprocating pairs. Consistent with evolutionary theories of cooperation, reciprocating country pairs exhibit higher levels of stable cooperation and are more likely to punish instances of noncooperation. However, countries in reciprocity-based relationships are also quicker to forgive single acts of noncooperation by eventually returning to previous levels of mutual cooperation. By contrast, nonreciprocating pairs are more likely to exploit each other's cooperation via higher rates of defection. Together, these findings provide the strongest evidence to date that reciprocity is a widespread mechanism for achieving international cooperation.

Cyclic Fatigue Life of Two Single File Engine-Driven Systems in Simulated Curved Canals.

PubMed

Nabavizadeh, Mohammad Reza; Sedigh-Shams, Mahdi; Abdolrasoulnia, Sara

2018-01-01

This study aimed to evaluate the cyclic fatigue resistance of two single file engine-driven instruments, Reciproc and NeoNiTi, in simulated root canals. Two groups of 15 NiTi endodontic instruments with an identical tip size of 0.25 mm were tested: Reciproc R25 (group A) and NeoNiTi A1 (group B). Cyclic fatigue testing was performed in a stainless steel artificial canal. The simulated canals had a 60 ° angle and 5-mm radius curvature. The Reciproc instruments were operated using the preset program on torque control electric motor specific for the Reciproc instruments, while the NeoNiTi instruments were operated using the manufacturer recommendation. All instruments were rotated until fracture occurred, and the number of cycles to fracture (NCF) and the length of the fractured tip were recorded and registered. Means and standard deviations of NCF and fragment length were calculated for each system and data were subjected to Student's t test ( P <0.05). A statistically significant difference ( P <0.05) was noted between Reciproc and NeoNiTi instruments. NeoNiTi A1 instruments were associated with a significantly higher mean NCF as compared to Reciproc R25 instruments (833±176 vs. 318±87 NCF). There was no significant difference ( P >0.05) in the mean length of the fractured fragments between the instruments. NeoNiTi instruments were associated with a significantly higher cyclic fatigue resistance than Reciproc instruments.

Apical Transportation, Centering Ability, and Cleaning Effectiveness of Reciprocating Single-file System Associated with Different Glide Path Techniques.

PubMed

de Carvalho, Guilherme Moreira; Sponchiado Junior, Emílio Carlos; Garrido, Angela Delfina Bittencourt; Lia, Raphael Carlos Comelli; Garcia, Lucas da Fonseca Roberti; Marques, André Augusto Franco

2015-12-01

The aim of this study was to evaluate the apical transportation, the centering ability, and the cleaning effectiveness of a reciprocating single-file system associated to different glide path techniques. The mesial root canals of 52 mandibular molars were randomly distributed into 4 groups (n = 13) according to the different glide path techniques used before biomechanical preparation with Reciproc System (RS): KF/RS (sizes 10 and 15 K-files), NGP/RS (no glide path, only reciprocating system), PF/RS (sizes 13, 16, and 19 PathFile instruments), and NP (no preparation). Cone-beam computed tomography analysis was performed before and after instrumentation for apical third images acquisition. Apical transportation and its direction were evaluated by using the formula D = (X1 - X2) - (Y1 - Y2), and the centering ability was analyzed by the formula CC = (X1 - X2/Y1 - Y2 or Y1 - Y2/X1 - X2). The samples were submitted to histologic processing and analyzed under a digital microscope for debris quantification. The values were statistically analyzed (Kruskal-Wallis, the Dunn multiple comparisons test, P < .05). All groups had similar apical transportation values, with no significant difference among them (P > .05). Groups had a tendency toward transportation in the mesial direction. No technique had perfect centering ability (=1.0), with no significant difference among them. KF/RS had larger amount of debris, with statistically significant difference in comparison with NGP/RS (P > .05). The different glide path techniques promoted minimal apical transportation, and the reciprocating single-file system tested remained relatively centralized within the root canal. Also, the different techniques interfered in the cleaning effectiveness of the reciprocating system. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Dynamic ASXL1 Exon Skipping and Alternative Circular Splicing in Single Human Cells

PubMed Central

Natarajan, Sivaraman; Carter, Robert; Brown, Patrick O.

2016-01-01

Circular RNAs comprise a poorly understood new class of noncoding RNA. In this study, we used a combination of targeted deletion, high-resolution splicing detection, and single-cell sequencing to deeply probe ASXL1 circular splicing. We found that efficient circular splicing required the canonical transcriptional start site and inverted AluSx elements. Sequencing-based interrogation of isoforms after ASXL1 overexpression identified promiscuous linear splicing between all exons, with the two most abundant non-canonical linear products skipping the exons that produced the circular isoforms. Single-cell sequencing revealed a strong preference for either the linear or circular ASXL1 isoforms in each cell, and found the predominant exon skipping product is frequently co-expressed with its reciprocal circular isoform. Finally, absolute quantification of ASXL1 isoforms confirmed our findings and suggests that standard methods overestimate circRNA abundance. Taken together, these data reveal a dynamic new view of circRNA genesis, providing additional framework for studying their roles in cellular biology. PMID:27736885

Comparison of the root canal debridement ability of two single file systems with a conventional multiple rotary system in long oval-shaped root canals: In vitro study.

PubMed

Khoshbin, Elham; Shokri, Abbas; Donyavi, Zakieh; Shahriari, Shahriar; Salehimehr, Golsa; Farhadian, Maryam; Kavandi, Zeinab

2017-08-01

This study sought to compare the root canal debridement ability of Neolix, Reciproc and ProTaper rotary systems in long oval-shaped root canals. Eighty five extracted single-rooted human teeth with long oval-shaped single root canals were selected and divided into three experimental groups(n=25) and one control group (n= 10). Root canals were filled with Vitapex radiopaque contrast medium and prepared with Neolix, Reciproc or ProTaper systems. The control group only received irrigation. Digital radiographs were obtained at baseline and postoperatively and subjected to digital subtraction. The percentage of reduction in contrast medium was quantified at 0-5 mm and 5-10 mm distances from the apex. The data were analyzed using one-way ANOVA and t-test. The mean percentage of the contrast medium removed was not significantly different in the 0-5mm segment among the three groups ( P =0.6). In the 5-10mm segment a significant difference was found in this regard among the ProTaper and Reciproc groups ( P =0.02) and the highest mean percentage of contrast medium was removed by ProTaper. But, difference between ProTaper and Neolix as well as Neolix and Reciproc was not significant. In Neolix ( P =0.024) and Reciproc ( P =0.002) systems, the mean percentage of the contrast medium removed from the 0-5mm segment was significantly greater than that in 5-10mm segment; however, this difference was not significant in ProTaper group ( P =0.069). Neolix single-file system may be a suitable alternative to ProTaper multiple-file system in debridement of long oval shaped canals. Key words: Root Canal Preparation, Debridement, Root Canal Therapy.

Cleaning Effectiveness of a Reciprocating Single-file and a Conventional Rotary Instrumentation System.

PubMed

de Carvalho, Fredson Marcio Acris; Gonçalves, Leonardo Cantanhede de Oliveira; Marques, André Augusto Franco; Alves, Vanessa; Bueno, Carlos Eduardo da Silveira; De Martin, Alexandre Sigrist

2016-01-01

To compare cleaning effectiveness by histological analysis of a reciprocating single-file system with ProTaper rotary instruments during the preparation of curved root canals in extracted teeth. A total of 40 root canals with curvatures ranging between 20 - 40 degrees were divided into two groups of 20 canals. Canals were prepared to the following apical sizes: Reciproc size 25 (n=20); ProTaper: F2 (n=20). The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for the test (Mann-Whitney U test, P < .05) were statistically analyzed using the GraphPad InStat for the Mac OS software (GraphPad Software, La Jolla, CA, USA). There were no significant differences in remaining debris (P > .05) between the two groups. The application of reciprocating motion during instrumentation did not result in increased debris when compared with continuous rotation motion, even in the apical part of curved canals. Both instruments resulted in debris in the canal lumen, irrespective of the movement kinematics applied.

Microtomography-based comparison of reciprocating single-file F2 ProTaper technique versus rotary full sequence.

PubMed

Paqué, Frank; Zehnder, Matthias; De-Deus, Gustavo

2011-10-01

A preparation technique with only 1 single instrument was proposed on the basis of the reciprocating movement of the F2 ProTaper instrument. The present study was designed to quantitatively assess canal preparation outcomes achieved by this technique. Twenty-five extracted human mandibular first molars with 2 separate mesial root canals were selected. Canals were randomly assigned to 1 of the 2 experimental groups: group 1, rotary conventional preparation by using ProTaper, and group 2, reciprocate instrumentation with 1 single ProTaper F2 instrument. Specimens were scanned initially and after root canal preparation with an isotropic resolution of 20 μm by using a micro-computed tomography system. The following parameters were assessed: changes in dentin volume, percentage of shaped canal walls, and degree of canal transportation. In addition, the time required to reach working length with the F2 instrument was recorded. Preoperatively, there were no differences regarding root canal curvature and volume between experimental groups. Overall, instrumentation led to enlarged canal shapes with no evidence of preparation errors. There were no statistical differences between the 2 preparation techniques in the anatomical parameters assessed (P > .01), except for a significantly higher canal transportation caused by the reciprocating file in the coronal canal third. On the other hand, preparation was faster by using the single-file technique (P < .01). Shaping outcomes with the single-file F2 ProTaper technique and conventional ProTaper full-sequence rotary approach were similar. However, the single-file F2 ProTaper technique was markedly faster in reaching working length. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of coronal flaring on apical extrusion of debris during root canal instrumentation using single-file systems.

PubMed

Topçuoğlu, H S; Üstün, Y; Akpek, F; Aktı, A; Topçuoğlu, G

2016-09-01

To evaluate the effect of coronal flaring on the amount of debris extruded apically during root canal preparation using the Reciproc, WaveOne (WO) and OneShape (OS) single-file systems. Ninety extracted single-rooted mandibular incisor teeth were randomly assigned to six groups (n = 15 for each group) for canal instrumentation. Endodontic access cavities were prepared in each tooth. In three of the six groups, coronal flaring was not performed; coronal flaring was performed with Gates-Glidden drills on all teeth in the remaining three groups. The canals were then instrumented with one or other of the following single-file instrument systems: Reciproc, WO and OS. Debris extruded apically during instrumentation was collected into pre-weighed Eppendorf tubes. The tubes were then stored in an incubator at 70 °C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. Data were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests (P = 0.05). Reciproc and WO files without coronal flaring produced significantly more debris compared with the other groups (P < 0.05). There was no significant difference in apical extrusion of debris amongst the other groups (P > 0.05). All single-file systems caused apical extrusion of debris. Performing coronal flaring prior to canal preparation reduced the amount of apically extruded debris when using Reciproc or WO systems. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Fast calculation of the sensitivity matrix in magnetic induction tomography by tetrahedral edge finite elements and the reciprocity theorem.

PubMed

Hollaus, K; Magele, C; Merwa, R; Scharfetter, H

2004-02-01

Magnetic induction tomography of biological tissue is used to reconstruct the changes in the complex conductivity distribution by measuring the perturbation of an alternating primary magnetic field. To facilitate the sensitivity analysis and the solution of the inverse problem a fast calculation of the sensitivity matrix, i.e. the Jacobian matrix, which maps the changes of the conductivity distribution onto the changes of the voltage induced in a receiver coil, is needed. The use of finite differences to determine the entries of the sensitivity matrix does not represent a feasible solution because of the high computational costs of the basic eddy current problem. Therefore, the reciprocity theorem was exploited. The basic eddy current problem was simulated by the finite element method using symmetric tetrahedral edge elements of second order. To test the method various simulations were carried out and discussed.

The relationship between reciprocity and burnout in Dutch medical residents.

PubMed

Prins, Jelle T; Gazendam-Donofrio, Stacey M; Dillingh, Gea S; van de Wiel, Harry B M; van der Heijden, Frank M M A; Hoekstra-Weebers, Josette E H M

2008-07-01

This study examined reciprocity in medical residents' relationships with supervisors, fellow residents, nurses and patients, and associations between reciprocity and burnout. Furthermore, we considered if a discrepancy between the perceived and preferred levels of reciprocity influenced the level of burnout complaints. In 2003, self-report questionnaires were sent to the homes of all 292 medical residents at the University Medical Centre Groningen (UMCG), Groningen, the Netherlands. Reciprocity was measured with a single-item reciprocity scale based on the Hatfield Global Measure of Equity Scale. The Utrecht Burn-Out Scale (UBOS/MBI-HHS) was used to measure burnout. A total of 158 residents participated in the study. Those who reported under-benefiting in the relationship with supervisors perceived significantly more emotional exhaustion and depersonalisation than those who perceived a reciprocal relationship. Residents who indicated that they over-benefited in the relationship with nurses reported more emotional exhaustion than residents who perceived a reciprocal relationship and less personal accomplishment than residents who perceived a reciprocal relationship or under-benefit. No differences on the burnout subscales were found between residents who perceived their relationships with patients and fellow residents to be reciprocal and those who considered they under- or over-benefited. The greater the discrepancy between perceived and preferred reciprocity in the relationship with the supervisor, the more emotional exhaustion residents reported. Perceptions of reciprocity in relationships with supervisors and nurses had particular influence on the level of burnout complaints among residents. The discrepancy between the impacts of perceived and preferred reciprocity on burnout was negligible and the only significant relationship to emerge concerned that with emotional exhaustion.

Embodied cognition and circular causality: on the role of constitutive autonomy in the reciprocal coupling of perception and action

PubMed Central

Vernon, David; Lowe, Robert; Thill, Serge; Ziemke, Tom

2015-01-01

The reciprocal coupling of perception and action in cognitive agents has been firmly established: perceptions guide action but so too do actions influence what is perceived. While much has been said on the implications of this for the agent's external behavior, less attention has been paid to what it means for the internal bodily mechanisms which underpin cognitive behavior. In this article, we wish to redress this by reasserting that the relationship between cognition, perception, and action involves a constitutive element as well as a behavioral element, emphasizing that the reciprocal link between perception and action in cognition merits a renewed focus on the system dynamics inherent in constitutive biological autonomy. Our argument centers on the idea that cognition, perception, and action are all dependent on processes focussed primarily on the maintenance of the agent's autonomy. These processes have an inherently circular nature—self-organizing, self-producing, and self-maintaining—and our goal is to explore these processes and suggest how they can explain the reciprocity of perception and action. Specifically, we argue that the reciprocal coupling is founded primarily on their endogenous roles in the constitutive autonomy of the agent and an associated circular causality of global and local processes of self-regulation, rather than being a mutual sensory-motor contingency that derives from exogenous behavior. Furthermore, the coupling occurs first and foremost via the internal milieu realized by the agent's organismic embodiment. Finally, we consider how homeostasis and the related concept of allostasis contribute to this circular self-regulation. PMID:26579043

Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-file Systems.

PubMed

Prabhakar, Attiguppe R; Yavagal, Chandrashekar; Dixit, Kratika; Naik, Saraswathi V

2016-01-01

Primary root canals are considered to be most challenging due to their complex anatomy. "Wave one" and "one shape" are single-file systems with reciprocating and rotary motion respectively. The aim of this study was to evaluate and compare dentin thickness, centering ability, canal transportation, and instrumentation time of wave one and one shape files in primary root canals using a cone beam computed tomographic (CBCT) analysis. This is an experimental, in vitro study comparing the two groups. A total of 24 extracted human primary teeth with minimum 7 mm root length were included in the study. Cone beam computed tomographic images were taken before and after the instrumentation for each group. Dentin thickness, centering ability, canal transportation, and instrumentation times were evaluated for each group. A significant difference was found in instrumentation time and canal transportation measures between the two groups. Wave one showed less canal transportation as compared with one shape, and the mean instrumentation time of wave one was significantly less than one shape. Reciprocating single-file systems was found to be faster with much less procedural errors and can hence be recommended for shaping the root canals of primary teeth. How to cite this article: Prabhakar AR, Yavagal C, Dixit K, Naik SV. Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-File Systems. Int J Clin Pediatr Dent 2016;9(1):45-49.

Shaping ability of 4 different single-file systems in simulated S-shaped canals.

PubMed

Saleh, Abdulrahman Mohammed; Vakili Gilani, Pouyan; Tavanafar, Saeid; Schäfer, Edgar

2015-04-01

The aim of this study was to compare the shaping ability of 4 different single-file systems in simulated S-shaped canals. Sixty-four S-shaped canals in resin blocks were prepared to an apical size of 25 using Reciproc (VDW, Munich, Germany), WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), OneShape (Micro Méga, Besançon, France), and F360 (Komet Brasseler, Lemgo, Germany) (n = 16 canals/group) systems. Composite images were made from the superimposition of pre- and postinstrumentation images. The amount of resin removed by each system was measured by using a digital template and image analysis software. Canal aberrations and the preparation time were also recorded. The data were statistically analyzed by using analysis of variance, Tukey, and chi-square tests. Canals prepared with the F360 and OneShape systems were better centered compared with the Reciproc and WaveOne systems. Reciproc and WaveOne files removed significantly greater amounts of resin from the inner side of both curvatures (P < .05). Instrumentation with OneShape and Reciproc files was significantly faster compared with WaveOne and F360 files (P < .05). No instrument fractured during canal preparation. Under the conditions of this study, all single-file instruments were safe to use and were able to prepare the canals efficiently. However, single-file systems that are less tapered seem to be more favorable when preparing S-shaped canals. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The timing of sequences of saccades in visual search.

PubMed Central

Van Loon, E M; Hooge, I Th C; Van den Berg, A V

2002-01-01

According to the LATER model (linear approach to thresholds with ergodic rate), the latency of a single saccade in response to target appearance can be understood as a decision process, which is subject to (i) variations in the rate of (visual) information processing; and (ii) the threshold for the decision. We tested whether the LATER model can also be applied to the sequences of saccades in a multiple fixation search, during which latencies of second and subsequent saccades are typically shorter than that of the initial saccade. We found that the distributions of the reciprocal latencies for later saccades, unlike those of the first saccade, are highly asymmetrical, much like a gamma distribution. This suggests that the normal distribution of the rate r, which the LATER model assumes, is not appropriate to describe the rate distributions of subsequent saccades in a scanning sequence. By contrast, the gamma distribution is also appropriate to describe the distribution of reciprocal latencies for the first saccade. The change of the gamma distribution parameters as a function of the ordinal number of the saccade suggests a lowering of the threshold for second and later saccades, as well as a reduction in the number of target elements analysed. PMID:12184827

Influence of operator's experience on root canal shaping ability with a rotary nickel-titanium single-file reciprocating motion system.

PubMed

Muñoz, Estefanía; Forner, Leopoldo; Llena, Carmen

2014-04-01

The aim of this study was to evaluate the influence of the operator's experience on the shaping of double-curvature simulated root canals with a nickel-titanium single-file reciprocating motion system. Sixty double-curvature root canals simulated in methacrylate blocks were prepared by 10 students without any experience in endodontics and by 10 professionals who had studied endodontics at the postgraduate level. The Reciproc-VDW system's R25 file was used in the root canal preparation. The blocks were photographed before and after the instrumentation, and the time of instrumentation was also evaluated. Changes in root canal dimensions were analyzed in 6 positions. Significant differences (P < .05) were found in the apical transport of the first root canal curvature, with a larger percentage of increase of the root canal occurring in the novice group than in the expert one, as well as in the canal deviation at the beginning of the curvatures, whereas no significant results were obtained in the growth rate of the canal area. There was difference in the time of instrumentation, with 3.76 minutes observed in the novice group, as opposed to 2.05 minutes in the expert group. The use of the single-file reciprocating motion system Reciproc is not seen to be influenced by the operator's experience regarding the increase of the canal area. Previous training and the need to acquire experience are important in the use of this system, in spite of its apparent simplicity. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Molarity (Aromic Density) of the Elements as Pure Crystals.

ERIC Educational Resources Information Center

Pauling, Linus; Herman, Zelek S.

1985-01-01

Provides background information for teachers on the atomic density of the elements as pure crystals. Atomic density is defined as the reciprocal of the atomic volume. Includes atomic-density diagrams which were prepared using the atomic-volume values given by Singman, supplemented by additional values for some allotropes. (JN)

Conflict and Fairness in Social Exchange

ERIC Educational Resources Information Center

Molm, Linda D.; Collett, Jessica L.; Schaefer, David R.

2006-01-01

Inherent to all social exchange relations are elements of both cooperation and competition. We develop and test a theoretical model which proposes that the relative salience of the competitive, conflictual elements of exchange mediate and explain the negative effects of negotiated exchange, as compared with reciprocal exchange, on actors'…

Evaluation of Single File Systems Reciproc, Oneshape, and WaveOne using Cone Beam Computed Tomography -An In Vitro Study.

PubMed

Dhingra, Annil; Ruhal, Nidhi; Miglani, Anjali

2015-04-01

Successful endodontic therapy depends on many factor, one of the most important step in any root canal treatment is root canal preparation. In addition, respecting the original shape of the canal is of the same importance; otherwise, canal aberrations such as transportation will be created. The purpose of this study is to compare and evaluate Reciprocating WaveOne ,Reciproc and Rotary Oneshape Single File Instrumentation System On Cervical Dentin Thickness, Cross Sectional Area and Canal Transportation on First Mandibular Molar Using Cone Beam Computed Tomography. Sixty Mandibular First Molars extracted due to periodontal reason was collected from the Department of Oral and Maxillofacial. Teeth were prepared using one rotary and two reciprocating single file system. Teeth were divided into 3 groups 20 teeth in each group. Pre instrumentation and Post instrumentation scans was done and evaluated for three parameters Canal Transportation, Cervical Dentinal Thickness, Cross-sectional Area. Results were analysed statistically using ANOVA, Post-Hoc Tukey analysis. The change in cross-sectional area after filing showed significant difference at 0mm, 1mm, 2mm and 7mm (p<0.001, p =0.006, 0.004 & <0.001 respectively). There was significant difference between wave one and oneshape; oneshape and reciproc at 0mm, 1mm, 2mm & 7mm (p-values for waveone and Oneshape <0.001, 0.022, 0.011 & <0.001 resp. and for oneshape and reciproc < 0.001, p= 0.011, p=0.008 & <0.001). On assessing the transportation of the three file system over a distance of 7 mm (starting from 0mm and then evaluation at 1mm, 2mm, 3mm, 5mm and 7mm), the results showed a significant difference among the file systems at various lengths (p= 0.014, 0.046, 0.004, 0.028, 0.005 & 0.029 respectively). Mean value of cervical dentinal removal is maximum at all the levels for oneshape and minimum for waveone showing the better quality of waveone and reciproc over oneshape file system. Significant difference was found at 9mm, 11mm and 12mm between all the three file systems (p<0.001,< 0.001, <0.001). It was concluded that reciprocating motion is better than rotary motion in all the three parameters Canal Transportation, Cross-sectional Area, Cervical Dentinal Thickness.

The Reciprocal Relationship between Motivation and Self-Regulation: A Longitudinal Study on Academic Performance

ERIC Educational Resources Information Center

Ning, Hoi Kwan; Downing, Kevin

2010-01-01

While previous studies have examined the single directional effects of motivation constructs in influencing students' use of self-regulatory strategies, few attempts have been made to unravel their interrelationship in a unified framework. In this study we adopt the social cognitive perspective and examine the reciprocal interplay between…

Ameliorating the English Reading Comprehension of Spanish-Speaking ELLs through a Reciprocal Teaching Intervention

ERIC Educational Resources Information Center

Ramos, Jose A.

2012-01-01

Through a single-subject multiple-baseline across-participants design, the present study examined the effects of Reciprocal Teaching (RT) instruction and Spanish use on the cognitive strategy use and English reading comprehension of four, 4th grade Spanish-speaking bilingual students that are "good" decoders but "poor"…

Cleaning Effectiveness of a Reciprocating Single-file and a Conventional Rotary Instrumentation System

PubMed Central

de Carvalho, Fredson Marcio Acris; Gonçalves, Leonardo Cantanhede de Oliveira; Marques, André Augusto Franco; Alves, Vanessa; Bueno, Carlos Eduardo da Silveira; De Martin, Alexandre Sigrist

2016-01-01

Objective: To compare cleaning effectiveness by histological analysis of a reciprocating single-file system with ProTaper rotary instruments during the preparation of curved root canals in extracted teeth. Methods: A total of 40 root canals with curvatures ranging between 20 - 40 degrees were divided into two groups of 20 canals. Canals were prepared to the following apical sizes: Reciproc size 25 (n=20); ProTaper: F2 (n=20). The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for the test (Mann-Whitney U test, P < .05) were statistically analyzed using the GraphPad InStat for the Mac OS software (GraphPad Software, La Jolla, CA, USA). Results: There were no significant differences in remaining debris (P > .05) between the two groups. Conclusion: The application of reciprocating motion during instrumentation did not result in increased debris when compared with continuous rotation motion, even in the apical part of curved canals. Both instruments resulted in debris in the canal lumen, irrespective of the movement kinematics applied. PMID:28217185

Liposuction cannula device and method

DOEpatents

Weber, Paul J.; Visuri, Steven R.; Everett, Matthew J.; Da Silva, Luiz B.; Kolster, Alwin H.

2003-10-28

A liposuction apparatus and method optionally having a sonic or ultrasonic source with an axial lumen passage in which the shaft can be made to reciprocate (oscillate) in a non-rectilinear fashion. The apparatus may also contain the concomitant use of rectilinear reciprocation motion in addition to ultrasonic motion or energy along the shaft of the apparatus. The advantages of the liposuction apparatus are as follows: 1) non-rectilinear single shaft reciprocating cannula, 2) sonic or ultrasonic energy delivered to the distal tip, 3) rectilinear reciprocating cannula with ultrasonic energy along the shaft from the handle, and 4) any of the above reciprocating components powered by excess unused vacuum capacity in the liposuction aspirator (suction engine) apparatus. There are three (3) primary sources of energy applied to the cannula shaft: the first is the oscillating surgeon's arm motion (approximately 1-2 hertz); the reciprocating motion (of about 100 Hz); and the optional concomitant motion as delivered by the ultrasonic energy (e.g. 25 KHz).

Liposuction Cannula Device And Method

DOEpatents

Weber, Paul J.; Visuri, Steven R.; Everett, Matthew J.; Da Silva, Luiz B.; Kolster, Alwin H.

2005-04-05

A liposuction apparatus and method optionally having a sonic or ultrasonic source with an axial lumen passage in which the shaft can be made to reciprocate (oscillate) in a non-rectilinear fashion. The apparatus may also contain the concomitant use of rectilinear reciprocation motion in addition to ultrasonic motion or energy along the shaft of the apparatus. The advantages of the liposuction apparatus are as follows: 1) non-rectilinear single shaft reciprocating cannula, 2) sonic or ultrasonic energy delivered to the distal tip, 3) rectilinear reciprocating cannula with ultrasonic energy along the shaft from the handle, and 4) any of the above reciprocating components powered by excess unused vacuum capacity in the liposuction aspirator (suction engine) apparatus. There are three (3) primary sources of energy applied to the cannula shaft: the first is the oscillating surgeon's arm motion (approximately 1-2 hertz); the reciprocating motion (of about 100 Hz); and the optional concomitant motion as delivered by the ultrasonic energy (e.g. 25 KHz).

Reciproc versus Twisted file for root canal filling removal: assessment of apically extruded debris.

PubMed

Altunbas, Demet; Kutuk, Betul; Toyoglu, Mustafa; Kutlu, Gizem; Kustarci, Alper; Er, Kursat

2016-01-01

The aim of this study was to evaluate the amount of apically extruded debris during endodontic retreatment with different file systems. Sixty extracted human mandibular premolar teeth were used in this study. Root canals of the teeth were instrumented and filled before being randomly assigned to three groups. Guttapercha was removed using the Reciproc system, the Twisted File system (TF), and Hedström-files (H-file). Apically extruded debris was collected and dried in pre-weighed Eppendorf tubes. The amount of extruded debris was assessed with an electronic balance. Data were statistically analyzed using one-way ANOVA, Kruskal-Wallis, and Mann-Whitney U tests. The Reciproc and TF systems extruded significantly less debris than the H-file (p<0.05). However, no significant difference was found between the Reciproc and TF systems. All tested file systems caused apical extrusion of debris. Both the rotary file (TF) and the reciprocating single-file (Reciproc) systems were associated with less apical extrusion compared with the H-file.

Reciprocal space mapping and single-crystal scattering rods.

PubMed

Smilgies, Detlef M; Blasini, Daniel R; Hotta, Shu; Yanagi, Hisao

2005-11-01

Reciprocal space mapping using a linear gas detector in combination with a matching Soller collimator has been applied to map scattering rods of well oriented organic microcrystals grown on a solid surface. Formulae are provided to correct image distortions in angular space and to determine the required oscillation range, in order to measure properly integrated scattering intensities.

Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-file Systems

PubMed Central

Prabhakar, Attiguppe R; Yavagal, Chandrashekar; Naik, Saraswathi V

2016-01-01

ABSTRACT Background: Primary root canals are considered to be most challenging due to their complex anatomy. "Wave one" and "one shape" are single-file systems with reciprocating and rotary motion respectively. The aim of this study was to evaluate and compare dentin thickness, centering ability, canal transportation, and instrumentation time of wave one and one shape files in primary root canals using a cone beam computed tomographic (CBCT) analysis. Study design: This is an experimental, in vitro study comparing the two groups. Materials and methods: A total of 24 extracted human primary teeth with minimum 7 mm root length were included in the study. Cone beam computed tomographic images were taken before and after the instrumentation for each group. Dentin thickness, centering ability, canal transportation, and instrumentation times were evaluated for each group. Results: A significant difference was found in instrumentation time and canal transportation measures between the two groups. Wave one showed less canal transportation as compared with one shape, and the mean instrumentation time of wave one was significantly less than one shape. Conclusion: Reciprocating single-file systems was found to be faster with much less procedural errors and can hence be recommended for shaping the root canals of primary teeth. How to cite this article: Prabhakar AR, Yavagal C, Dixit K, Naik SV. Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-File Systems. Int J Clin Pediatr Dent 2016;9(1):45-49. PMID:27274155

Does the Reciproc file remove root canal bacteria and endotoxins as effectively as multifile rotary systems?

PubMed

Marinho, A C S; Martinho, F C; Gonçalves, L M; Rabang, H R C; Gomes, B P F A

2015-06-01

To evaluate the effectiveness of Reciproc for the removal of cultivable bacteria and endotoxins from root canals in comparison with multifile rotary systems. The root canals of forty human single-rooted mandibular pre-molars were contaminated with an Escherichia coli suspension for 21 days and randomly assigned to four groups according to the instrumentation system: GI - Reciproc (VDW); GII - Mtwo (VDW); GIII - ProTaper Universal (Dentsply Maillefer); and GIV -FKG Race(™) (FKG Dentaire) (n = 10 per group). Bacterial and endotoxin samples were taken with a sterile/apyrogenic paper point before (s1) and after instrumentation (s2). Culture techniques determined the colony-forming units (CFU) and the Limulus Amebocyte Lysate assay was used for endotoxin quantification. Results were submitted to paired t-test and anova. At s1, bacteria and endotoxins were recovered in 100% of the root canals investigated (40/40). After instrumentation, all systems were associated with a highly significant reduction of the bacterial load and endotoxin levels, respectively: GI - Reciproc (99.34% and 91.69%); GII - Mtwo (99.86% and 83.11%); GIII - ProTaper (99.93% and 78.56%) and GIV - FKG Race(™) (99.99% and 82.52%) (P < 0.001). No statistical difference were found amongst the instrumentation systems regarding bacteria and endotoxin removal (P > 0.01). The reciprocating single file, Reciproc, was as effective as the multifile rotary systems for the removal of bacteria and endotoxins from root canals. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Post endodontic pain following single-visit root canal preparation with rotary vs reciprocating instruments: a meta-analysis of randomized clinical trials.

PubMed

Hou, Xiao-Mei; Su, Zheng; Hou, Ben-Xiang

2017-05-25

In endodontic therapy, continuous rotary instrumentation reduced debris compared to reciprocal instrumentation, which might affect the incidence of post-endodontic pain (PP). The aim of our study was to assess whether PP incidence and levels were influenced by the choice of rotary or reciprocal instruments. In this meta-analysis the Pubmed and EM databases were searched for prospective clinical randomized trials published before April 20, 2016, using combinations of the keywords: root canal preparation/instrumentation/treatment/therapy; post-operative/endodontic pain; reciprocal and rotary instruments. Three studies were included, involving a total of 1,317 patients, 659 treated with reciprocating instruments and 658 treated with rotary instruments. PP was reported in 139 patients in the reciprocating group and 172 in the rotary group. The PP incidence odds ratio was 1.27 with 95% confidence interval (CI) (0.25, 6.52) favoring rotary instruments. The mild, moderate and severe PP levels odds ratios were 0.31 (0.11, 0.84), 2.24 (0.66, 7.59) and 11.71 (0.63, 218.15), respectively. No evidence of publication bias was found. Rotary instrument choice in endodontic therapy is associated with a lower incidence of PP than reciprocating instruments, while reciprocating instruments are associated with less mild PP incidence.

Fatigue Testing of Wing Beam by the Resonance Method

NASA Technical Reports Server (NTRS)

Bleakney, William M

1938-01-01

Preliminary fatigue tests on two aluminum-alloy wing-beam specimens subjected to reversed axial loading are described. The motion used consists in incorporating one or two reciprocating motors in a resonance system of which the specimen is the spring element. A description is given of the reciprocating motors, and of the method of assembling and adjusting the vibrating system. The results indicate that the method is well adapted to fatigue tests of not only uniform wing beams but also wing beams with asymmetrical local reinforcements.

X-ray diffraction tomography of polycrystalline materials: present and future (Conference Presentation)

NASA Astrophysics Data System (ADS)

Stock, Stuart R.; Almer, Jonathan D.; Birkedal, Henrik

2016-10-01

Scattered x-radiation can be used for computed tomographic reconstruction of the distribution of crystallographic phases within the interior of specimens, and diffraction patterns can be measured for each volume element (voxel) within a reconstructed slice. This modality has been applied to systems as diverse as mineralized tissues and inorganic composites. Use of high energy x-rays (E < 40 keV) offers advantages including the ability to study volumes deep with specimens and to sample large ranges of reciprocal space, i.e., many reflections. The bases of diffraction tomography are reviewed, and the power of the technique is illustrated by the results obtained for specimens containing: a) different materials (SiC/Al composite), b) different polytypes (calcite/aragonite in a bivalve attachment system); c) mixtures of nanocrystalline and amorphous phases; d) a single phase, but volumes with different lattice parameters (hydroxyapatite, hAp, the mineral in bone and tooth); e) a single phase containing a spatial distribution of crystallographic texture (bone); a single phase with a spatial distribution of strains produced by in situ loading (bone). Finally, challenges and future directions are discussed.

A reciprocal theorem for a mixture theory. [development of linearized theory of interacting media

NASA Technical Reports Server (NTRS)

Martin, C. J.; Lee, Y. M.

1972-01-01

A dynamic reciprocal theorem for a linearized theory of interacting media is developed. The constituents of the mixture are a linear elastic solid and a linearly viscous fluid. In addition to Steel's field equations, boundary conditions and inequalities on the material constants that have been shown by Atkin, Chadwick and Steel to be sufficient to guarantee uniqueness of solution to initial-boundary value problems are used. The elements of the theory are given and two different boundary value problems are considered. The reciprocal theorem is derived with the aid of the Laplace transform and the divergence theorem and this section is concluded with a discussion of the special cases which arise when one of the constituents of the mixture is absent.

Efficacy of Twisted File Adaptive, Reciproc and ProTaper Universal Retreatment instruments for root-canal-filling removal: A cone-beam computed tomography study.

PubMed

Akbulut, Makbule Bilge; Akman, Melek; Terlemez, Arslan; Magat, Guldane; Sener, Sevgi; Shetty, Heeresh

2016-01-01

The aim of this study was to evaluate the efficacy of Twisted File (TF) Adaptive, Reciproc, and ProTaper Universal Retreatment (UR) System instruments for removing root-canal-filling. Sixty single rooted teeth were decoronated, instrumented and obturated. Preoperative CBCT scans were taken and the teeth were retreated with TF Adaptive, Reciproc, ProTaper UR, or hand files (n=15). Then, the teeth were rescanned, and the percentage volume of the residual root-canal-filling material was established. The total time for retreatment was recorded, and the data was statistically analyzed. The statistical ranking of the residual filling material volume was as follows: hand file=TF Adaptive>ProTaper UR=Reciproc. The ProTaper UR and Reciproc systems required shorter periods of time for retreatment. Root canal filling was more efficiently removed by using Reciproc and ProTaper UR instruments than TF Adaptive instruments and hand files. The TF Adaptive system was advantageous over hand files with regard to operating time.

Sub-pm{{\\sqrt{Hz}^{-1}}} non-reciprocal noise in the LISA backlink fiber

NASA Astrophysics Data System (ADS)

Fleddermann, Roland; Diekmann, Christian; Steier, Frank; Tröbs, Michael; Heinzel, Gerhard; Danzmann, Karsten

2018-04-01

The future space-based gravitational wave detector laser interferometer space antenna (LISA) requires bidirectional exchange of light between its two optical benches on board of each of its three satellites. The current baseline foresees a polarization-maintaining single-mode fiber for this backlink connection. Phase changes which are common in both directions do not enter the science measurement, but differential (‘non-reciprocal’) phase fluctuations directly do and must thus be guaranteed to be small enough. We have built a setup consisting of a Zerodur baseplate with fused silica components attached to it using hydroxide-catalysis bonding and demonstrated the reciprocity of a polarization-maintaining single-mode fiber at the 1 pm \\sqrt{Hz}-1 level as is required for LISA. We used balanced detection to reduce the influence of parasitic optical beams on the reciprocity measurement and a fiber length stabilization to avoid nonlinear effects in our phase measurement system (phase meter). For LISA, a different phase meter is planned to be used that does not show this nonlinearity. We corrected the influence of beam angle changes and temperature changes on the reciprocity measurement in post-processing.

Endodontic treatment of mandibular molar with root dilaceration using Reciproc single-file system.

PubMed

Meireles, Daniely Amorin; Bastos, Mariana Mena Barreto; Marques, André Augusto Franco; Garcia, Lucas da Fonseca Roberti; Sponchiado, Emílio Carlos

2013-08-01

Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods.

Evaluation of Single File Systems Reciproc, Oneshape, and WaveOne using Cone Beam Computed Tomography –An In Vitro Study

PubMed Central

Dhingra, Annil; Miglani, Anjali

2015-01-01

Background Successful endodontic therapy depends on many factor, one of the most important step in any root canal treatment is root canal preparation. In addition, respecting the original shape of the canal is of the same importance; otherwise, canal aberrations such as transportation will be created. Aim The purpose of this study is to compare and evaluate Reciprocating WaveOne ,Reciproc and Rotary Oneshape Single File Instrumentation System On Cervical Dentin Thickness, Cross Sectional Area and Canal Transportation on First Mandibular Molar Using Cone Beam Computed Tomography. Materials and Methods Sixty Mandibular First Molars extracted due to periodontal reason was collected from the Department of Oral and Maxillofacial. Teeth were prepared using one rotary and two reciprocating single file system. Teeth were divided into 3 groups 20 teeth in each group. Pre instrumentation and Post instrumentation scans was done and evaluated for three parameters Canal Transportation, Cervical Dentinal Thickness, Cross-sectional Area. Results were analysed statistically using ANOVA, Post-Hoc Tukey analysis. Results The change in cross-sectional area after filing showed significant difference at 0mm, 1mm, 2mm and 7mm (p<0.001, p =0.006, 0.004 & <0.001 respectively). There was significant difference between wave one and oneshape; oneshape and reciproc at 0mm, 1mm, 2mm & 7mm (p-values for waveone and Oneshape <0.001, 0.022, 0.011 & <0.001 resp. and for oneshape and reciproc < 0.001, p= 0.011, p=0.008 & <0.001). On assessing the transportation of the three file system over a distance of 7 mm (starting from 0mm and then evaluation at 1mm, 2mm, 3mm, 5mm and 7mm), the results showed a significant difference among the file systems at various lengths (p= 0.014, 0.046, 0.004, 0.028, 0.005 & 0.029 respectively). Mean value of cervical dentinal removal is maximum at all the levels for oneshape and minimum for waveone showing the better quality of waveone and reciproc over oneshape file system. Significant difference was found at 9mm, 11mm and 12mm between all the three file systems (p<0.001,< 0.001, <0.001). Conclusion It was concluded that reciprocating motion is better than rotary motion in all the three parameters Canal Transportation, Cross-sectional Area, Cervical Dentinal Thickness. PMID:26023639

Multiple scattering in planetary regoliths using first-order incoherent interactions

NASA Astrophysics Data System (ADS)

Muinonen, Karri; Markkanen, Johannes; Väisänen, Timo; Penttilä, Antti

2017-10-01

We consider scattering of light by a planetary regolith modeled using discrete random media of spherical particles. The size of the random medium can range from microscopic sizes of a few wavelengths to macroscopic sizes approaching infinity. The size of the particles is assumed to be of the order of the wavelength. We extend the numerical Monte Carlo method of radiative transfer and coherent backscattering (RT-CB) to the case of dense packing of particles. We adopt the ensemble-averaged first-order incoherent extinction, scattering, and absorption characteristics of a volume element of particles as input for the RT-CB. The volume element must be larger than the wavelength but smaller than the mean free path length of incoherent extinction. In the radiative transfer part, at each absorption and scattering process, we account for absorption with the help of the single-scattering albedo and peel off the Stokes parameters of radiation emerging from the medium in predefined scattering angles. We then generate a new scattering direction using the joint probability density for the local polar and azimuthal scattering angles. In the coherent backscattering part, we utilize amplitude scattering matrices along the radiative-transfer path and the reciprocal path, and utilize the reciprocity of electromagnetic waves to verify the computation. We illustrate the incoherent volume-element scattering characteristics and compare the dense-medium RT-CB to asymptotically exact results computed using the Superposition T-matrix method (STMM). We show that the dense-medium RT-CB compares favorably to the STMM results for the current cases of sparse and dense discrete random media studied. The novel method can be applied in modeling light scattering by the surfaces of asteroids and other airless solar system objects, including UV-Vis-NIR spectroscopy, photometry, polarimetry, and radar scattering problems.Acknowledgments. Research supported by European Research Council with Advanced Grant No. 320773 SAEMPL, Scattering and Absorption of ElectroMagnetic waves in ParticuLate media. Computational resources provided by CSC - IT Centre for Science Ltd, Finland.

The Importance of Collegiality and Reciprocal Learning in the Professional Development of Beginning Teachers

ERIC Educational Resources Information Center

Patrick, Fiona; Elliot, Dely; Hulme, Moira; McPhee, Alastair

2010-01-01

This paper discusses factors that enhance induction experiences for beginning teachers. It reports the findings from case studies that explore the impact of new entrants to the teaching profession in Scotland. The data suggest that the most supportive induction processes mix both formal and informal elements, but that the informal elements such as…

Incidence of dentinal defects after root canal preparation: reciprocating versus rotary instrumentation.

PubMed

Bürklein, Sebastian; Tsotsis, Polymnia; Schäfer, Edgar

2013-04-01

The purpose of this study was to evaluate the incidence of dentinal defects after root canal preparation with reciprocating instruments (Reciproc and WaveOne) and rotary instruments. One hundred human central mandibular incisors were randomly assigned to 5 groups (n = 20 teeth per group). The root canals were instrumented by using the reciprocating single-file systems Reciproc and WaveOne and the full-sequence rotary Mtwo and ProTaper instruments. One group was left unprepared as control. Roots were sectioned horizontally at 3, 6, and 9 mm from the apex and evaluated under a microscope by using 25-fold magnification. The presence of dentinal defects (complete/incomplete cracks and craze lines) was noted and analyzed by using the chi-square test. No defects were observed in the controls. All canal preparation created dentinal defects. Overall, instrumentation with Reciproc was associated with more complete cracks than the full-sequence files (P = .021). Although both reciprocating files produced more incomplete cracks apically (3 mm) compared with the rotary files (P = .001), no statistically significant differences were obtained concerning the summarized values of all cross sections (P > .05). Under the conditions of this study, root canal preparation with both rotary and reciprocating instruments resulted in dentinal defects. At the apical level of the canals, reciprocating files produced significantly more incomplete dentinal cracks than full-sequence rotary systems (P < .05). Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Assessment of postoperative pain after reciprocating or rotary NiTi instrumentation of root canals: a randomized, controlled clinical trial.

PubMed

Relvas, João Bosko Formigas; Bastos, Mariana Mena Barreto; Marques, André Augusto Franco; Garrido, Angela Delfina Bitencourt; Sponchiado, Emílio Carlos

2016-11-01

The aim of this study was to assess postoperative pain in a prospective randomized clinical trial comparing two groups, using the Reciproc® system in one group and the ProTaper® rotary system in the other. The study included 78 male patients, aged 18-64 years (mean age of 26 years), with asymptomatic pulp necrosis in mandibular molar teeth (n = 78). The single-session endodontic treatment was performed by a single operator specialized in Endodontics. Mechanical preparation of the root canals was performed using the ProTaper® and Reciproc® instrumentation techniques. Postoperative pain was recorded using a verbal rating scale (VRS) and verbal description with well-defined categories at the three following time intervals: 24 h, 72 h, and 7 days after the endodontic procedure. The assessment of postoperative pain was recorded as no pain, mild pain, moderate pain, and severe pain or flare-up. Data were analyzed using the nonparametric Mann-Whitney test with the aid of the STATA® software. The incidence of postoperative pain in the ProTaper group (PT) 24 h after the endodontic procedure was 17.9 and 5.1 % after 72 h. In the Reciproc group (RP), the incidence after 24 h was 15.3 and 2.5 % after 72 h. No patients presented severe pain at the time intervals assessed. No significant difference (p > 0.05) in postoperative pain was found between the ProTaper® and Reciproc® instrumentation technique during endodontic treatment in this study. According to our findings and the results of the clinical trial, the occurrence of postoperative pain was low and similar between the reciprocating and rotary techniques during the time intervals assessed. These results are different from basic laboratory studies that affirm that the reciprocating techniques tend to promote more postoperative pain since extrusion of debris is greater.

The Role of Different Types of Feedback in the Reciprocal Interaction of Teaching Performance and Self-Efficacy Belief

ERIC Educational Resources Information Center

Akkuzu, Nalan

2014-01-01

The purpose of this study was to explore the role of feedback based on self-efficacy belief sources in the reciprocal interaction of teaching performance and self-efficacy beliefs. A single case study design was employed to address and began to bridge the gap in our understanding of the relationship between feedback, self-efficacy belief and…

The Effects of the Reciprocal and the Self-Check Styles on Pupils' Performance in Primary Physical Education

ERIC Educational Resources Information Center

Kolovelonis, Athanasios; Goudas, Marios; Gerodimos, Vassilios

2011-01-01

The aim of this study was to examine the effects of the reciprocal and the self-check teaching styles on pupils' basketball chest pass performance and on related psychosocial variables in a single physical education session. Participants were 64 fifth and sixth grade pupils between 11 and 12 years of age who were randomly assigned to three…

Modeling thermoelastic distortion of optics using elastodynamic reciprocity

NASA Astrophysics Data System (ADS)

King, Eleanor; Levin, Yuri; Ottaway, David; Veitch, Peter

2015-07-01

Thermoelastic distortion resulting from optical absorption by transmissive and reflective optics can cause unacceptable changes in optical systems that employ high-power beams. In advanced-generation laser-interferometric gravitational wave detectors, for example, optical absorption is expected to result in wavefront distortions that would compromise the sensitivity of the detector, thus necessitating the use of adaptive thermal compensation. Unfortunately, these systems have long thermal time constants, and so predictive feed-forward control systems could be required, but the finite-element analysis is computationally expensive. We describe here the use of the Betti-Maxwell elastodynamic reciprocity theorem to calculate the response of linear elastic bodies (optics) to heating that has arbitrary spatial distribution. We demonstrate, using a simple example, that it can yield accurate results in computational times that are significantly less than those required for finite-element analyses.

Expanding Lorentz and spectrum corrections to large volumes of reciprocal space for single-crystal time-of-flight neutron diffraction

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

Michels-Clark, Tara M.; Savici, Andrei T.; Lynch, Vickie E.

Evidence is mounting that potentially exploitable properties of technologically and chemically interesting crystalline materials are often attributable to local structure effects, which can be observed as modulated diffuse scattering (mDS) next to Bragg diffraction (BD). BD forms a regular sparse grid of intense discrete points in reciprocal space. Traditionally, the intensity of each Bragg peak is extracted by integration of each individual reflection first, followed by application of the required corrections. In contrast, mDS is weak and covers expansive volumes of reciprocal space close to, or between, Bragg reflections. For a representative measurement of the diffuse scattering, multiple sample orientationsmore » are generally required, where many points in reciprocal space are measured multiple times and the resulting data are combined. The common post-integration data reduction method is not optimal with regard to counting statistics. A general and inclusive data processing method is needed. In this contribution, a comprehensive data analysis approach is introduced to correct and merge the full volume of scattering data in a single step, while correctly accounting for the statistical weight of the individual measurements. Lastly, development of this new approach required the exploration of a data treatment and correction protocol that includes the entire collected reciprocal space volume, using neutron time-of-flight or wavelength-resolved data collected at TOPAZ at the Spallation Neutron Source at Oak Ridge National Laboratory.« less

Cyclic Fatigue Resistance of Reciproc, WaveOne, and WaveOne Gold Nickel-Titanium Instruments.

PubMed

Özyürek, Taha

2016-10-01

The purpose of this study was to compare the cyclic fatigue resistance of Reciproc R25 (VDW, Munich, Germany), WaveOne Primary (Dentsply Maillefer, Ballaigues, Switzerland), and WaveOne Gold Primary files (Dentsply Maillefer). Twenty Reciproc R25, 20 WaveOne Primary, and 20 WaveOne Gold Primary instruments were included in this study. The cyclic fatigue tests were performed using a cyclic fatigue testing device, which has an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius of curvature. The files were randomly divided into 3 groups (group 1: Reciproc R25; group 2: WaveOne Primary; and group 3: WaveOne Gold Primary). All the instruments were rotated until fracture occurred, and the time to fracture was recorded in seconds using a digital chronometer. The number of cycles to failure (NCF) was calculated. The data were analyzed statistically (P < .05). There was a significant difference among the groups (P < .05). The WaveOne Gold Primary showed the greatest mean of NCF (1628 ± 107), and the WaveOne Primary showed the lowest mean of NCF (1153 ± 119.2). Within the limitations of this in vitro study, the cyclic fatigue resistance of the WaveOne Gold Primary single-file system was higher than the WaveOne Primary and Reciproc R25 single-file instruments. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Expanding Lorentz and spectrum corrections to large volumes of reciprocal space for single-crystal time-of-flight neutron diffraction

DOE PAGES

Michels-Clark, Tara M.; Savici, Andrei T.; Lynch, Vickie E.; ...

2016-03-01

Evidence is mounting that potentially exploitable properties of technologically and chemically interesting crystalline materials are often attributable to local structure effects, which can be observed as modulated diffuse scattering (mDS) next to Bragg diffraction (BD). BD forms a regular sparse grid of intense discrete points in reciprocal space. Traditionally, the intensity of each Bragg peak is extracted by integration of each individual reflection first, followed by application of the required corrections. In contrast, mDS is weak and covers expansive volumes of reciprocal space close to, or between, Bragg reflections. For a representative measurement of the diffuse scattering, multiple sample orientationsmore » are generally required, where many points in reciprocal space are measured multiple times and the resulting data are combined. The common post-integration data reduction method is not optimal with regard to counting statistics. A general and inclusive data processing method is needed. In this contribution, a comprehensive data analysis approach is introduced to correct and merge the full volume of scattering data in a single step, while correctly accounting for the statistical weight of the individual measurements. Lastly, development of this new approach required the exploration of a data treatment and correction protocol that includes the entire collected reciprocal space volume, using neutron time-of-flight or wavelength-resolved data collected at TOPAZ at the Spallation Neutron Source at Oak Ridge National Laboratory.« less

Postoperative quality of life following single-visit root canal treatment performed by rotary or reciprocating instrumentation: a randomized clinical trial.

PubMed

Pasqualini, D; Corbella, S; Alovisi, M; Taschieri, S; Del Fabbro, M; Migliaretti, G; Carpegna, G C; Scotti, N; Berutti, E

2016-11-01

To compare the impact of rotary and reciprocating instrumentation on postoperative quality of life (POQoL) after single-visit primary root canal treatment. A randomized controlled clinical trial was designed and carried out in a University endodontic practice in northern Italy. Healthy subjects with asymptomatic irreversible pulpitis, symptomatic irreversible pulpitis or pulp necrosis with or without apical periodontitis (symptomatic or asymptomatic) scheduled for primary root canal treatment were enrolled. Single-visit root canal treatment was performed with ProTaper ™ S1-S2-F1-F2 (rotary group, n = 23) and WaveOne ™ Primary (reciprocating group, n = 24). Irrigation was performed with 5% NaOCl and 10% EDTA. Root canal filling was performed with the continuous-wave technique and ZOE sealer. POQoL indicators were evaluated for 7 days post-treatment. The variation of each indicator over time was compared using anova for repeated measures (P < 0.05). The impact of each variable on POQoL was analysed with a multivariate logistic regression model (P < 0.05). Pain curves demonstrated a more favourable time-trend in the rotary group (mean, P = 0.077; maximum, P = 0.015). Difficulty in eating (P = 0.017), in performing daily activities (P = 0.023), in sleeping (P = 0.021) and in social relations (P = 0.077), was more evident in the reciprocating group. Patients' perception of the impact of treatment on POQoL was more favourable in the rotary group (P = 0.006). Multirooted tooth type and pre-existing periradicular inflammation were associated with a decrease in POQoL. Reciprocating instrumentation affected POQoL to a greater extent than rotary instrumentation. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

In situ three-dimensional reciprocal-space mapping during mechanical deformation.

PubMed

Cornelius, T W; Davydok, A; Jacques, V L R; Grifone, R; Schülli, T; Richard, M I; Beutier, G; Verdier, M; Metzger, T H; Pietsch, U; Thomas, O

2012-09-01

Mechanical deformation of a SiGe island epitaxically grown on Si(001) was studied by a specially adapted atomic force microscope and nanofocused X-ray diffraction. The deformation was monitored during in situ mechanical loading by recording three-dimensional reciprocal-space maps around a selected Bragg peak. Scanning the energy of the incident beam instead of rocking the sample allowed the safe and reliable measurement of the reciprocal-space maps without removal of the mechanical load. The crystal truncation rods originating from the island side facets rotate to steeper angles with increasing mechanical load. Simulations of the displacement field and the intensity distribution, based on the finite-element method, reveal that the change in orientation of the side facets of about 25° corresponds to an applied pressure of 2-3 GPa on the island top plane.

Postoperative pain intensity after using different instrumentation techniques: a randomized clinical study

PubMed Central

ÇIÇEK, Ersan; KOÇAK, Mustafa Murat; KOÇAK, Sibel; SAĞLAM, Baran Can; TÜRKER, Sevinç Aktemur

2017-01-01

Abstract Postoperative pain is a frequent complication associated with root canal treatment, especially during apical instrumentation of tooth with preexisting periradicular inflammation Objectives The aim of this clinical study was to evaluate the influence of the instrumentation techniques on the incidence and intensity of postoperative pain in single-visit root canal treatment. Material and Methods Ninety patients with single root/canal and non-vital pulps were included. The patients were assigned into 3 groups according to root canal instrumentation technique used; modified step-back, reciprocal, and rotational techniques. Root canal treatment was carried out in a single visit and the severity of postoperative pain was assessed via 4-point pain intensity scale. All the participants were called through the phone at 12, 24 and 48 h to obtain the pain scores. Data were analyzed through the Kruskal–Wallis test. Results There was significant difference between all groups (p<0.05). The modified step-back technique produced postoperative pain significantly lower than the rotational (p=0.018) and reciprocal (p=0.020) techniques. No difference was found between the reciprocal and rotational techniques (p=0.868). Postoperative pain in the first 12 h period (p=0.763) and in the 24 h period (p=0.147) was not significantly different between the groups. However, the difference in the 48 h period was statistically different between the groups (p=0.040). Conclusion All instrumentation techniques caused postoperative pain. The modified step-back technique produced less pain compared to the rotational and reciprocal techniques. PMID:28198972

Feminist Research Practice: Learning from Older Women.

ERIC Educational Resources Information Center

Leane, Maire; Duggan, Helen; Chambers, Pat

2002-01-01

The process of collecting oral histories from 21 older Irish women incorporated elements of feminist research, including equalized power relations between researchers and participants, reciprocal information, empowerment of participants, and ownership of data. (Contains 17 references.) (SK)

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

Caruso, M., E-mail: mcaruso@ugr.es; Fanchiotti, H.; Canal, C.A. Garcia

An equivalence between the Schroedinger dynamics of a quantum system with a finite number of basis states and a classical dynamics is presented. The equivalence is an isomorphism that connects in univocal way both dynamical systems. We treat the particular case of neutral kaons and found a class of electric networks uniquely related to the kaon system finding the complete map between the matrix elements of the effective Hamiltonian of kaons and those elements of the classical dynamics of the networks. As a consequence, the relevant {epsilon} parameter that measures CP violation in the kaon system is completely determined inmore » terms of network parameters. - Highlights: > We provide a formal equivalence between classical and quantum dynamics. > We make use of the decomplexification concept. > Neutral kaon systems can be represented by electric circuits. > CP symmetry violation can be taken into account by non-reciprocity. > Non-reciprocity is represented by gyrators.« less

Swimming by reciprocal motion at low Reynolds number.

PubMed

Qiu, Tian; Lee, Tung-Chun; Mark, Andrew G; Morozov, Konstantin I; Münster, Raphael; Mierka, Otto; Turek, Stefan; Leshansky, Alexander M; Fischer, Peer

2014-11-04

Biological microorganisms swim with flagella and cilia that execute nonreciprocal motions for low Reynolds number (Re) propulsion in viscous fluids. This symmetry requirement is a consequence of Purcell's scallop theorem, which complicates the actuation scheme needed by microswimmers. However, most biomedically important fluids are non-Newtonian where the scallop theorem no longer holds. It should therefore be possible to realize a microswimmer that moves with reciprocal periodic body-shape changes in non-Newtonian fluids. Here we report a symmetric 'micro-scallop', a single-hinge microswimmer that can propel in shear thickening and shear thinning (non-Newtonian) fluids by reciprocal motion at low Re. Excellent agreement between our measurements and both numerical and analytical theoretical predictions indicates that the net propulsion is caused by modulation of the fluid viscosity upon varying the shear rate. This reciprocal swimming mechanism opens new possibilities in designing biomedical microdevices that can propel by a simple actuation scheme in non-Newtonian biological fluids.

Studies of self-reciprocating characteristic of carbon nanotube film-based cantilevers under light and thermal radiation.

PubMed

Gong, Zhongcheng; Tseng, Yi-Hsuan; He, Yuan; Que, Long

2012-01-01

Self-reciprocating characteristic of carbon nanotube film (CNF)-Cu cantilevers upon exposure to light and thermal radiation was observed. This unique characteristic offers an attractive technical platform for harvesting solar and thermal energies on a single chip, which has been demonstrated recently. This paper reports the detailed experimental studies of this phenomenon. It reveals that the low-frequency self-reciprocation, sensitive to the thicknesses of CNF and Cu and the intensity of the light and thermal radiation, is mainly attributed to the electrostatic interaction among randomly connected carbon nanotubes (CNTs) in CNF. This is due to the fact that electrical currents in CNF induced by light and thermal radiation also exhibit an oscillating characteristic, similar to the self-reciprocating characteristic of the CNF-Cu cantilevers. The mechanism for this observed phenomenon is also discussed by relating the optical, thermal, electrical, elastic and mechanical properties of the CNF.

Small-angle X-ray scattering tensor tomography: model of the three-dimensional reciprocal-space map, reconstruction algorithm and angular sampling requirements.

PubMed

Liebi, Marianne; Georgiadis, Marios; Kohlbrecher, Joachim; Holler, Mirko; Raabe, Jörg; Usov, Ivan; Menzel, Andreas; Schneider, Philipp; Bunk, Oliver; Guizar-Sicairos, Manuel

2018-01-01

Small-angle X-ray scattering tensor tomography, which allows reconstruction of the local three-dimensional reciprocal-space map within a three-dimensional sample as introduced by Liebi et al. [Nature (2015), 527, 349-352], is described in more detail with regard to the mathematical framework and the optimization algorithm. For the case of trabecular bone samples from vertebrae it is shown that the model of the three-dimensional reciprocal-space map using spherical harmonics can adequately describe the measured data. The method enables the determination of nanostructure orientation and degree of orientation as demonstrated previously in a single momentum transfer q range. This article presents a reconstruction of the complete reciprocal-space map for the case of bone over extended ranges of q. In addition, it is shown that uniform angular sampling and advanced regularization strategies help to reduce the amount of data required.

Reciprocity principle for scattered fields from discontinuities in waveguides.

PubMed

Pau, Annamaria; Capecchi, Danilo; Vestroni, Fabrizio

2015-01-01

This study investigates the scattering of guided waves from a discontinuity exploiting the principle of reciprocity in elastodynamics, written in a form that applies to waveguides. The coefficients of reflection and transmission for an arbitrary mode can be derived as long as the principle of reciprocity is satisfied at the discontinuity. Two elastodynamic states are related by the reciprocity. One is the response of the waveguide in the presence of the discontinuity, with the scattered fields expressed as a superposition of wave modes. The other state is the response of the waveguide in the absence of the discontinuity oscillating according to an arbitrary mode. The semi-analytical finite element method is applied to derive the needed dispersion relation and wave mode shapes. An application to a solid cylinder with a symmetric double change of cross-section is presented. This model is assumed to be representative of a damaged rod. The coefficients of reflection and transmission of longitudinal waves are investigated for selected values of notch length and varying depth. Copyright © 2014 Elsevier B.V. All rights reserved.

Dramatic genotypic difference in, and effect of genetic crossing on, tissue culture-induced mobility of retrotransposon Tos17 in rice.

PubMed

Lin, Chunjing; Lin, Xiuyun; Hu, Lanjuan; Yang, Jingjing; Zhou, Tianqi; Long, Likun; Xu, Chunming; Xing, Shaochen; Qi, Bao; Dong, Yingshan; Liu, Bao

2012-11-01

KEY MESSAGE : We show for the first time that intraspecific crossing may impact mobility of the prominent endogenous retrotransposon Tos17 under tissue culture conditions in rice. Tos17, an endogenous copia retrotransposon of rice, is transpositionally active in tissue culture. To study whether there exists fundamental genotypic difference in the tissue culture-induced mobility of Tos17, and if so, whether the difference is under genetic and/or epigenetic control, we conducted this investigation. We show that dramatic difference in tissue culture-induced Tos17 mobility exists among different rice pure-line cultivars sharing the same maternal parent: of the three lines studied that harbor Tos17, two showed mobilization of Tos17, which accrued in proportion to subculture duration, while the third line showed total quiescence (immobility) of the element and the fourth line did not contain the element. In reciprocal F1 hybrids between Tos17-mobile and -immobile (or absence) parental lines, immobility was dominant over mobility. In reciprocal F1 hybrids between both Tos17-mobile parental lines, an additive or synergistic effect on mobility of the element was noticed. In both types of reciprocal F1 hybrids, clear difference in the extent of Tos17 mobility was noted between crossing directions. Given that all lines share the same maternal parent, this observation indicates the existence of epigenetic parent-of-origin effect. We conclude that the tissue culture-induced mobility of Tos17 in rice is under complex genetic and epigenetic control, which can be either enhanced or repressed by intraspecific genetic crossing.

Reciprocity relationships in vector acoustics and their application to vector field calculations.

PubMed

Deal, Thomas J; Smith, Kevin B

2017-08-01

The reciprocity equation commonly stated in underwater acoustics relates pressure fields and monopole sources. It is often used to predict the pressure measured by a hydrophone for multiple source locations by placing a source at the hydrophone location and calculating the field everywhere for that source. A similar equation that governs the orthogonal components of the particle velocity field is needed to enable this computational method to be used for acoustic vector sensors. This paper derives a general reciprocity equation that accounts for both monopole and dipole sources. This vector-scalar reciprocity equation can be used to calculate individual components of the received vector field by altering the source type used in the propagation calculation. This enables a propagation model to calculate the received vector field components for an arbitrary number of source locations with a single model run for each vector field component instead of requiring one model run for each source location. Application of the vector-scalar reciprocity principle is demonstrated with analytic solutions for a range-independent environment and with numerical solutions for a range-dependent environment using a parabolic equation model.

Storage of electric and magnetic energy in passive nonreciprocal networks

NASA Technical Reports Server (NTRS)

Smith, W. E.

1969-01-01

Examination of the relation of stored electric and magnetic energy within a system to the terminal behavior of nonreciprocal passive networks shows both similarities and important differences between wholly reciprocal systems and systems containing nonreciprocal elements.

Alcohol Expectancies, Perceived Norms and Drinking Behavior among College Students: Examining the Reciprocal Determinism Hypothesis

PubMed Central

Wardell, Jeffrey D.; Read, Jennifer P.

2012-01-01

Social learning mechanisms, such as descriptive norms for drinking behavior (norms) and positive alcohol expectancies (PAEs), play a major role in college student alcohol use. According to the principle of reciprocal determinism (Bandura, 1977), norms and PAEs should be reciprocally associated with alcohol use, each influencing one another over time. However, the nature of these prospective relationships for college students is in need of further investigation. This study provided the first examination of the unique reciprocal associations among norms, PAEs, and drinking together in a single model. PAEs become more stable with age, whereas norms are likely to be more dynamic upon college entry. Thus, we hypothesized that alcohol use would show stronger reciprocal associations with norms than with PAEs for college students. Students (N=557; 67% female) completed online measures of PAEs, norms and quantity and frequency of alcohol use in September of their first (T1), second (T2), and third (T3) years of college. Reciprocal associations were analyzed using a cross-lagged panel design. PAEs had unidirectional influences on frequency and quantity of alcohol use, with no prospective effects from alcohol use to PAEs. Reciprocal associations were observed between norms and alcohol use, but only for quantity and not frequency. Specifically, drinking quantity prospectively predicted quantity norms and quantity norms prospectively predicted drinking quantity. This effect was observed across both years in the model. These findings support the reciprocal determinism hypothesis for norms but not for PAEs in college students, and may help to inform norm-based interventions. PMID:23088403

Alcohol expectancies, perceived norms, and drinking behavior among college students: examining the reciprocal determinism hypothesis.

PubMed

Wardell, Jeffrey D; Read, Jennifer P

2013-03-01

Social learning mechanisms, such as descriptive norms for drinking behavior (norms) and positive alcohol expectancies (PAEs), play a major role in college student alcohol use. According to the principle of reciprocal determinism (Bandura, 1977), norms and PAEs should be reciprocally associated with alcohol use, each influencing one another over time. However, the nature of these prospective relationships for college students is in need of further investigation. This study provided the first examination of the unique reciprocal associations among norms, PAEs, and drinking together in a single model. PAEs become more stable with age, whereas norms are likely to be more dynamic upon college entry. Thus, we hypothesized that alcohol use would show stronger reciprocal associations with norms than with PAEs for college students. Students (N = 557; 67% women) completed online measures of PAEs, norms, and quantity and frequency of alcohol use in September of their first (T1), second (T2), and third (T3) years of college. Reciprocal associations were analyzed using a cross-lagged panel design. PAEs had unidirectional influences on frequency and quantity of alcohol use, with no prospective effects from alcohol use to PAEs. Reciprocal associations were observed between norms and alcohol use, but only for quantity and not for frequency. Specifically, drinking quantity prospectively predicted quantity norms and quantity norms prospectively predicted drinking quantity. This effect was observed across both years in the model. These findings support the reciprocal determinism hypothesis for norms but not for PAEs in college students and may help to inform norm-based interventions. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Viscoelastic reciprocating contacts in presence of finite rough interfaces: A numerical investigation

NASA Astrophysics Data System (ADS)

Putignano, Carmine; Carbone, Giuseppe

2018-05-01

Viscoelastic reciprocating contacts are crucial in a number of systems, ranging from sealing components to viscoelastic dampers. Roughness plays in these conditions a central role, but no exhaustive assessment in terms of influence on area, separation and friction has been drawn so far. This is due to the huge number of time and space scales involved in the problem. By means of an innovative Boundary Element methodology, which treats the time as a parameter and then requires only to discretize the space domain, we investigate the viscoelastic reciprocating contact mechanics between rough solids. In particular, we consider the alternate contact of a rigid finite-size rough punch over a viscoelastic layer: the importance of the domain finiteness in the determination of the contact area and the contact solution anisotropy is enlightened. Implications on real system may be drawn on this basis. Finally, we focus on the hysteretic cycle related to the viscoelastic tangential forces.

High-energy x-ray diffraction from surfaces and nanoparticles

NASA Astrophysics Data System (ADS)

Hejral, U.; Müller, P.; Shipilin, M.; Gustafson, J.; Franz, D.; Shayduk, R.; Rütt, U.; Zhang, C.; Merte, L. R.; Lundgren, E.; Vonk, V.; Stierle, A.

2017-11-01

High-energy surface-sensitive x-ray diffraction (HESXRD) is a powerful high-energy photon technique (E > 70 keV) that has in recent years proven to allow a fast data acquisition for the 3D structure determination of surfaces and nanoparticles under in situ and operando conditions. The use of a large-area detector facilitates the direct collection of nearly distortion-free diffraction patterns over a wide q range, including crystal truncation rods perpendicular to the surface and large-area reciprocal space maps from epitaxial nanoparticles, which is not possible in the conventional low-photon energy approach (E =10 -20 keV ). Here, we present a comprehensive mathematical approach, explaining the working principle of HESXRD for both single-crystal surfaces and epitaxial nanostructures on single-crystal supports. The angular calculations used in conventional crystal truncation rod measurements at low-photon energies are adopted for the high-photon-energy regime, illustrating why and to which extent large reciprocal-space areas can be probed in stationary geometry with fixed sample rotation. We discuss how imperfections such as mosaicity and finite domain size aid in sampling a substantial part of reciprocal space without the need of rotating the sample. An exact account is given of the area probed in reciprocal space using such a stationary mode, which is essential for in situ or operando time-resolved experiments on surfaces and nanostructures.

Reciprocal inhibition between motor neurons of the tibialis anterior and triceps surae in humans.

PubMed

Yavuz, Utku Ş; Negro, Francesco; Diedrichs, Robin; Farina, Dario

2018-05-01

Motor neurons innervating antagonist muscles receive reciprocal inhibitory afferent inputs to facilitate the joint movement in the two directions. The present study investigates the mutual transmission of reciprocal inhibitory afferent inputs between the tibialis anterior (TA) and triceps surae (soleus and medial gastrocnemius) motor units. We assessed this mutual mechanism in large populations of motor units for building a statistical distribution of the inhibition amplitudes during standardized input to the motor neuron pools to minimize the effect of modulatory pathways. Single motor unit activities were identified using high-density surface electromyography (HDsEMG) recorded from the TA, soleus (Sol), and medial gastrocnemius (GM) muscles during isometric dorsi- and plantarflexion. Reciprocal inhibition on the antagonist muscle was elicited by electrical stimulation of the tibial (TN) or common peroneal nerves (CPN). The probability density distributions of reflex strength for each muscle were estimated to examine the strength of mutual transmission of reciprocal inhibitory input. The results showed that the strength of reciprocal inhibition in the TA motor units was fourfold greater than for the GM and the Sol motor units. This suggests an asymmetric transmission of reciprocal inhibition between ankle extensor and flexor muscles. This asymmetry cannot be explained by differences in motor unit type composition between the investigated muscles since we sampled low-threshold motor units in all cases. Therefore, the differences observed for the strength of inhibition are presumably due to a differential reciprocal spindle afferent input and the relative contribution of nonreciprocal inhibitory pathways. NEW & NOTEWORTHY We investigated the mutual transmission of reciprocal inhibition in large samples of motor units using a standardized input (electrical stimulation) to the motor neurons. The results demonstrated that the disynaptic reciprocal inhibition exerted between ankle flexor and extensor muscles is asymmetric. The functional implication of asymmetric transmission may be associated with the neural strategies of postural control.

The importance of relational coordination and reciprocal learning for chronic illness care within primary care teams.

PubMed

Noël, Polly Hitchcock; Lanham, Holly J; Palmer, Ray F; Leykum, Luci K; Parchman, Michael L

2013-01-01

Recent research from a complexity theory perspective suggests that implementation of complex models of care, such as the Chronic Care Model (CCM), requires strong relationships and learning capacities among primary care teams. Our primary aim was to assess the extent to which practice member perceptions of relational coordination and reciprocal learning were associated with the presence of CCM elements in community-based primary care practices. We used baseline measures from a cluster randomized controlled trial testing a practice facilitation intervention to implement the CCM and improve risk factor control for patients with Type 2 diabetes in small primary care practices. Practice members (i.e., physicians, nonphysician providers, and staff) completed baseline assessments, which included the Relational Coordination Scale, Reciprocal Learning Scale, and the Assessment of Chronic Illness Care (ACIC) survey, along with items assessing individual and clinic characteristics. To assess the association between Relational Coordination, Reciprocal Learning, and ACIC, we used a series of hierarchical linear regression models accounting for clustering of individual practice members within clinics and controlling for individual- and practice-level characteristics and tested for mediation effects. A total of 283 practice members from 39 clinics completed baseline measures. Relational Coordination scores were significantly and positively associated with ACIC scores (Model 1). When Reciprocal Learning was added, Relational Coordination remained a significant yet notably attenuated predictor of ACIC (Model 2). The mediation effect was significant (z = 9.3, p < .01); 24% of the association between Relational Coordination and ACIC scores was explained by Reciprocal Learning. Of the individual- and practice-level covariates included in Model 3, only the presence of an electronic medical record was significant; Relational Coordination and Reciprocal Learning remained significant independent predictors of ACIC. Efforts to implement complex models of care should incorporate strategies to strengthen relational coordination and reciprocal learning among team members.

The Importance of Relational Coordination and Reciprocal Learning for Chronic Illness Care within Primary Care Teams

PubMed Central

Noël, Polly Hitchcock; Lanham, Holly J.; Palmer, Ray F.; Leykum, Luci K.; Parchman, Michael L.

2012-01-01

Background Recent research from a complexity theory perspective suggests that implementation of complex models of care, such as the Chronic Care Model (CCM), requires strong relationships and learning capacities among primary care teams. Purposes Our primary aim was to assess the extent to which practice member perceptions of relational coordination and reciprocal learning were associated with the presence of CCM elements in community-based primary care practices. Methodology/Approach We used baseline measures from a cluster randomized controlled trial testing a practice facilitation intervention to implement the CCM and improve risk factor control for patients with type 2 diabetes in small primary care practices. Practice members (i.e., physicians, non-physician providers, and staff) completed baseline assessments, which included the Relational Coordination Scale, Reciprocal Learning Scale, and the Assessment of Chronic Illness Care (ACIC) survey, along with items assessing individual and clinic characteristics. To assess the association between Relational Coordination, Reciprocal Learning, and ACIC, we used a series of hierarchical linear regression models accounting for clustering of individual practice members within clinics and controlling for individual- and practice-level characteristics, and tested for mediation effects. Findings 283 practice members from 39 clinics completed baseline measures. Relational Coordination scores were significantly and positively associated with ACIC scores (Model 1). When Reciprocal Learning was added, Relational Coordination remained a significant yet notably attenuated predictor of ACIC (Model 2). The mediation effect was significant (z = 9.3, p<.01); 24% of the association between Relational Coordination and ACIC scores was explained by Reciprocal Learning. Of the individual and practice level covariates included in Model 3, only the presence of an electronic medical record was significant; Relational Coordination and Reciprocal Learning remained significant independent predictors of ACIC. Practice Implications Efforts to implement complex models of care should incorporate strategies to strengthen relational coordination and reciprocal learning among team members. PMID:22310483

Effects of NiTi rotary and reciprocating instruments on debris and smear layer scores: an SEM evaluation.

PubMed

Poggio, Claudio; Dagna, Alberto; Chiesa, Marco; Scribante, Andrea; Beltrami, Riccardo; Colombo, Marco

2014-12-30

The purpose of the present study was to investigate the cleaning efficacy of 2 different nickel-titanium (NiTi) rotary systems: a new single system Reciproc compared with the rotary full sequence Mtwo. The amount of debris and the morphology of smear layer were the parameters for the evaluation of the cleanliness of root canals. The null hypothesis of the study was that there would be no significant difference in debris scores and smear layer scores between the 2 systems. 
 Forty single-rooted freshly extracted teeth were selected and divided into 2 groups. For each group, all root canals were shaped with 2 different NiTi instruments (Mtwo and Reciproc) and irrigated with 5.25% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA) solutions by 3 trained operators. Specimens were fractured longitudinally and prepared for scanning electron microscopy (SEM) analysis at a standard magnification of ×5,000. The presence/absence of smear layer and the presence/absence of debris at the coronal, middle and apical third of each canal were evaluated using two 5-step scales for scores. Numeric data were analyzed using the Kruskal-Wallis and Mann-Whitney U statistical tests, and significance was set at a P value <0.05. 
 This study revealed significant differences among the various groups. The Mtwo group presented significantly lower smear layer scores than the Reciproc group (P<0.01) in the middle and apical third of the canal. 
 Conventional continuous rotary NiTi instruments associated with 5.25% NaOCl and 17% EDTA solutions seem to be better for obtaining clean dentinal canal walls. Reciprocating instruments leave a higher quantity of smear layer which covers dentinal walls and dentinal tubules.

Transcranial Electrical Neuromodulation Based on the Reciprocity Principle

PubMed Central

Fernández-Corazza, Mariano; Turovets, Sergei; Luu, Phan; Anderson, Erik; Tucker, Don

2016-01-01

A key challenge in multi-electrode transcranial electrical stimulation (TES) or transcranial direct current stimulation (tDCS) is to find a current injection pattern that delivers the necessary current density at a target and minimizes it in the rest of the head, which is mathematically modeled as an optimization problem. Such an optimization with the Least Squares (LS) or Linearly Constrained Minimum Variance (LCMV) algorithms is generally computationally expensive and requires multiple independent current sources. Based on the reciprocity principle in electroencephalography (EEG) and TES, it could be possible to find the optimal TES patterns quickly whenever the solution of the forward EEG problem is available for a brain region of interest. Here, we investigate the reciprocity principle as a guideline for finding optimal current injection patterns in TES that comply with safety constraints. We define four different trial cortical targets in a detailed seven-tissue finite element head model, and analyze the performance of the reciprocity family of TES methods in terms of electrode density, targeting error, focality, intensity, and directionality using the LS and LCMV solutions as the reference standards. It is found that the reciprocity algorithms show good performance comparable to the LCMV and LS solutions. Comparing the 128 and 256 electrode cases, we found that use of greater electrode density improves focality, directionality, and intensity parameters. The results show that reciprocity principle can be used to quickly determine optimal current injection patterns in TES and help to simplify TES protocols that are consistent with hardware and software availability and with safety constraints. PMID:27303311

Transcranial Electrical Neuromodulation Based on the Reciprocity Principle.

PubMed

Fernández-Corazza, Mariano; Turovets, Sergei; Luu, Phan; Anderson, Erik; Tucker, Don

2016-01-01

A key challenge in multi-electrode transcranial electrical stimulation (TES) or transcranial direct current stimulation (tDCS) is to find a current injection pattern that delivers the necessary current density at a target and minimizes it in the rest of the head, which is mathematically modeled as an optimization problem. Such an optimization with the Least Squares (LS) or Linearly Constrained Minimum Variance (LCMV) algorithms is generally computationally expensive and requires multiple independent current sources. Based on the reciprocity principle in electroencephalography (EEG) and TES, it could be possible to find the optimal TES patterns quickly whenever the solution of the forward EEG problem is available for a brain region of interest. Here, we investigate the reciprocity principle as a guideline for finding optimal current injection patterns in TES that comply with safety constraints. We define four different trial cortical targets in a detailed seven-tissue finite element head model, and analyze the performance of the reciprocity family of TES methods in terms of electrode density, targeting error, focality, intensity, and directionality using the LS and LCMV solutions as the reference standards. It is found that the reciprocity algorithms show good performance comparable to the LCMV and LS solutions. Comparing the 128 and 256 electrode cases, we found that use of greater electrode density improves focality, directionality, and intensity parameters. The results show that reciprocity principle can be used to quickly determine optimal current injection patterns in TES and help to simplify TES protocols that are consistent with hardware and software availability and with safety constraints.

Reciprocal Loss of CArG-Boxes and Auxin Response Elements Drives Expression Divergence of MPF2-Like MADS-Box Genes Controlling Calyx Inflation

PubMed Central

Khan, Muhammad Ramzan; Hu, Jinyong; Ali, Ghulam Muhammad

2012-01-01

Expression divergence is thought to be a hallmark of functional diversification between homologs post duplication. Modification in regulatory elements has been invoked to explain expression divergence after duplication for several MADS-box genes, however, verification of reciprocal loss of cis-regulatory elements is lacking in plants. Here, we report that the evolution of MPF2-like genes has entailed degenerative mutations in a core promoter CArG-box and an auxin response factor (ARF) binding element in the large 1st intron in the coding region. Previously, MPF2-like genes were duplicated into MPF2-like-A and -B through genome duplication in Withania and Tubocapsicum (Withaninae). The calyx of Withania grows exorbitantly after pollination unlike Tubocapsicum, where it degenerates. Besides inflated calyx syndrome formation, MPF2-like transcription factors are implicated in functions both during the vegetative and reproductive development as well as in phase transition. MPF2-like-A of Withania (WSA206) is strongly expressed in sepals, while MPF2-like-B (WSB206) is not. Interestingly, their combined expression patterns seem to replicate the pattern of their closely related hypothetical progenitors from Vassobia and Physalis. Using phylogenetic shadowing, site-directed mutagenesis and motif swapping, we could show that the loss of a conserved CArG-box in MPF2-like-B of Withania is responsible for impeding its expression in sepals. Conversely, loss of an ARE in MPF2-like-A relaxed the constraint on expression in sepals. Thus, the ARE is an active suppressor of MPF2-like gene expression in sepals, which in contrast is activated via the CArG-box. The observed expression divergence in MPF2-like genes due to reciprocal loss of cis-regulatory elements has added to genetic and phenotypic variations in the Withaninae and enhanced the potential of natural selection for the adaptive evolution of ICS. Moreover, these results provide insight into the interplay of floral developmental and hormonal pathways during ICS development and add to the understanding of the importance of polyploidy in plants. PMID:22900049

Microelectromechanical ratcheting apparatus

DOEpatents

Barnes, Stephen M.; Miller, Samuel L.; Jensen, Brian D.; Rodgers, M. Steven; Burg, Michael S.

2001-01-01

A microelectromechanical (MEM) ratcheting apparatus is disclosed which includes an electrostatic or thermal actuator that drives a moveable member in the form of a ring gear, stage, or rack. Motion is effected by one or more reciprocating pawls driven by the actuator in a direction that is parallel to, in line with, or tangential to the path. The reciprocating pawls engage indexing elements (e.g. teeth or pins) on the moveable member to incrementally move the member along a curved or straight path with the ability to precisely control and determine the position of the moveable member. The MEM apparatus can be formed on a silicon substrate by conventional surface micromachining methods.

Carcinogenesis: alterations in reciprocal interactions of normal functional structure of biologic systems.

PubMed

Davydyan, Garri

2015-12-01

The evolution of biologic systems (BS) includes functional mechanisms that in some conditions may lead to the development of cancer. Using mathematical group theory and matrix analysis, previously, it was shown that normally functioning BS are steady functional structures regulated by three basis regulatory components: reciprocal links (RL), negative feedback (NFB) and positive feedback (PFB). Together, they form an integrative unit maintaining system's autonomy and functional stability. It is proposed that phylogenetic development of different species is implemented by the splitting of "rudimentary" characters into two relatively independent functional parts that become encoded in chromosomes. The functional correlate of splitting mechanisms is RL. Inversion of phylogenetic mechanisms during ontogenetic development leads cell differentiation until cells reach mature states. Deterioration of reciprocal structure in the genome during ontogenesis gives rise of pathological conditions characterized by unsteadiness of the system. Uncontrollable cell proliferation and invasive cell growth are the leading features of the functional outcomes of malfunctioning systems. The regulatory element responsible for these changes is RL. In matrix language, pathological regulation is represented by matrices having positive values of diagonal elements ( TrA  > 0) and also positive values of matrix determinant ( detA  > 0). Regulatory structures of that kind can be obtained if the negative entry of the matrix corresponding to RL is replaced with the positive one. To describe not only normal but also pathological states of BS, a unit matrix should be added to the basis matrices representing RL, NFB and PFB. A mathematical structure corresponding to the set of these four basis functional patterns (matrices) is a split quaternion (coquaternion). The structure and specific role of basis elements comprising four-dimensional linear space of split quaternions help to understand what changes in mechanism of cell differentiation may lead to cancer development.

Structure characterization of MHEMT heterostructure elements with In0.4Ga0.6As quantum well grown by molecular beam epitaxy on GaAs substrate using reciprocal space mapping

NASA Astrophysics Data System (ADS)

Aleshin, A. N.; Bugaev, A. S.; Ermakova, M. A.; Ruban, O. A.

2016-03-01

The crystallographic parameters of elements of a metamorphic high-electron-mobility transistor (MHEMT) heterostructure with In0.4Ga0.6As quantum well are determined using reciprocal space mapping. The heterostructure has been grown by molecular-beam epitaxy (MBE) on the vicinal surface of a GaAs substrate with a deviation angle of 2° from the (001) plane. The structure consists of a metamorphic step-graded buffer (composed of six layers, including an inverse step), a high-temperature buffer of constant composition, and active high-electron-mobility transistor (HEMT) layers. The InAs content in the metamorphic buffer layers varies from 0.1 to 0.48. Reciprocal space mapping has been performed for the 004 and 224 reflections (the latter in glancing exit geometry). Based on map processing, the lateral and vertical lattice parameters of In x Ga1- x As ternary solid solutions of variable composition have been determined. The degree of layer lattice relaxation and the compressive stress are found within the linear elasticity theory. The high-temperature buffer layer of constant composition (on which active MHEMT layers are directly formed) is shown to have the highest (close to 100%) degree of relaxation in comparison with all other heterostructure layers and a minimum compressive stress.

Nonreciprocal Signal Routing in an Active Quantum Network

NASA Astrophysics Data System (ADS)

Tureci, Hakan E.; Metelmann, Anja

As superconductor quantum technologies are moving towards large-scale integrated circuits, a robust and flexible approach to routing photons at the quantum level becomes a critical problem. Active circuits, which contain driven linear or non-linear elements judiciously embedded in the circuit offer a viable solution. We present a general strategy for routing non-reciprocally quantum signals between two sites of a given lattice of resonators, implementable with existing superconducting circuit components. Our approach makes use of a dual lattice of superconducting non-linear elements on the links connecting the nodes of the main lattice. Solutions for spatially selective driving of the link-elements can be found, which optimally balance coherent and dissipative hopping of microwave photons to non-reciprocally route signals between two given nodes. In certain lattices these optimal solutions are obtained at the exceptional point of the scattering matrix of the network. The presented strategy provides a design space that is governed by a dynamically tunable non-Hermitian generator that can be used to minimize the added quantum noise as well. This work was supported by the U.S. Army Research Office (ARO) under Grant No. W911NF-15-1-0299.

Swimming by reciprocal motion at low Reynolds number

PubMed Central

Qiu, Tian; Lee, Tung-Chun; Mark, Andrew G.; Morozov, Konstantin I.; Münster, Raphael; Mierka, Otto; Turek, Stefan; Leshansky, Alexander M.; Fischer, Peer

2014-01-01

Biological microorganisms swim with flagella and cilia that execute nonreciprocal motions for low Reynolds number (Re) propulsion in viscous fluids. This symmetry requirement is a consequence of Purcell’s scallop theorem, which complicates the actuation scheme needed by microswimmers. However, most biomedically important fluids are non-Newtonian where the scallop theorem no longer holds. It should therefore be possible to realize a microswimmer that moves with reciprocal periodic body-shape changes in non-Newtonian fluids. Here we report a symmetric ‘micro-scallop’, a single-hinge microswimmer that can propel in shear thickening and shear thinning (non-Newtonian) fluids by reciprocal motion at low Re. Excellent agreement between our measurements and both numerical and analytical theoretical predictions indicates that the net propulsion is caused by modulation of the fluid viscosity upon varying the shear rate. This reciprocal swimming mechanism opens new possibilities in designing biomedical microdevices that can propel by a simple actuation scheme in non-Newtonian biological fluids. PMID:25369018

Most Uv-Induced Reciprocal Translocations in SORDARIA MACROSPORA Occur in or near Centromere Regions

PubMed Central

Leblon, G.; Zickler, D.; Lebilcot, S.

1986-01-01

In fungi, translocations can be identified and classified by the patterns of ascospore abortion in asci from crosses of rearrangement x normal sequence. Previous studies of UV-induced rearrangements in Sordaria macrospora revealed that a major class (called type III) appeared to be reciprocal translocations that were anomalous in producing an unexpected class of asci with four aborted ascospores in bbbbaaaa linear sequence (b = black; a = abortive). The present study shows that the anomalous type III rearrangements are, in fact, reciprocal translocations having both breakpoints within or adjacent to centromeres and that bbbbaaaa asci result from 3:1 disjunction from the translocation quadrivalent.—Electron microscopic observations of synaptonemal complexes enable centromeres to be visualized. Lengths of synaptonemal complexes lateral elements in translocation quadrivalents accurately reflect chromosome arm lengths, enabling breakpoints to be located reliably in centromere regions. All genetic data are consistent with the behavior expected of translocations with breakpoints at centromeres.—Two-thirds of the UV-induced reciprocal translocations are of this type. Certain centromere regions are involved preferentially. Among 73 type-III translocations, there were but 13 of the 21 possible chromosome combinations and 20 of the 42 possible combinations of chromosome arms. PMID:17246312

Most Uv-Induced Reciprocal Translocations in SORDARIA MACROSPORA Occur in or near Centromere Regions.

PubMed

Leblon, G; Zickler, D; Lebilcot, S

1986-02-01

In fungi, translocations can be identified and classified by the patterns of ascospore abortion in asci from crosses of rearrangement x normal sequence. Previous studies of UV-induced rearrangements in Sordaria macrospora revealed that a major class (called type III) appeared to be reciprocal translocations that were anomalous in producing an unexpected class of asci with four aborted ascospores in bbbbaaaa linear sequence (b = black; a = abortive). The present study shows that the anomalous type III rearrangements are, in fact, reciprocal translocations having both breakpoints within or adjacent to centromeres and that bbbbaaaa asci result from 3:1 disjunction from the translocation quadrivalent.-Electron microscopic observations of synaptonemal complexes enable centromeres to be visualized. Lengths of synaptonemal complexes lateral elements in translocation quadrivalents accurately reflect chromosome arm lengths, enabling breakpoints to be located reliably in centromere regions. All genetic data are consistent with the behavior expected of translocations with breakpoints at centromeres.-Two-thirds of the UV-induced reciprocal translocations are of this type. Certain centromere regions are involved preferentially. Among 73 type-III translocations, there were but 13 of the 21 possible chromosome combinations and 20 of the 42 possible combinations of chromosome arms.

Comparative analysis of strain fields in layers of step-graded metamorphic buffers of various designs

NASA Astrophysics Data System (ADS)

Aleshin, A. N.; Bugaev, A. S.; Ruban, O. A.; Tabachkova, N. Yu.; Shchetinin, I. V.

2017-10-01

Spatial distribution of residual elastic strain in the layers of two step-graded metamophic buffers of various designs, grown by molecular beam epitaxy from ternary InxAl1-xAs solutions on GaAs(001) substrates, is obtained using reciprocal space mapping by three-axis X-ray diffractometry and the linear theory of elasticity. The difference in the design of the buffers enabled the formation of a dislocation-free layer with different thickness in each of the heterostructures, which was the main basis of this study. It is shown that, in spite of the different design of graded metamorphic buffers, the nature of strain fields in them is the same, and the residual elastic strains in the final elements of both buffers adjusted for the effect of work hardening subject to the same phenomenological law, which describes the strain relief process in single-layer heterostructures.

Revealing the Crystalline Integrity of Wafer-Scale Graphene on SiO2/Si: An Azimuthal RHEED Approach.

PubMed

Lu, Zonghuan; Sun, Xin; Xiang, Yu; Washington, Morris A; Wang, Gwo-Ching; Lu, Toh-Ming

2017-07-12

The symmetry of graphene is usually determined by a low-energy electron diffraction (LEED) method when the graphene is on the conductive substrates, but LEED cannot handle graphene transferred to SiO 2 /Si substrates due to the charging effect. While transmission electron microscopy can generate electron diffraction on post-transferred graphene, this method is too localized. Herein, we employed an azimuthal reflection high-energy electron diffraction (RHEED) method to construct the reciprocal space mapping and determine the symmetry of wafer-size graphene both pre- and post-transfer. In this work, single-crystalline Cu(111) films were prepared on sapphire(0001) and spinel(111) substrates with sputtering. Then the graphene was epitaxially grown on single-crystalline Cu(111) films with a low pressure chemical vapor deposition. The reciprocal space mapping using azimuthal RHEED confirmed that the graphene grown on Cu(111) films was single-crystalline, no matter the form of the monolayer or multilayer structure. While the Cu(111) film grown on sapphire(0001) may occasionally consist of 60° in-plane rotational twinning, the reciprocal space mapping revealed that the in-plane orientation of graphene grown atop was not affected. The proposed method for checking the crystalline integrity of the post-transferred graphene sheets is an important step in the realization of the graphene as a platform to fabricate electronic and optoelectronic devices.

Identification of groundwater flow parameters using reciprocal data from hydraulic interference tests

NASA Astrophysics Data System (ADS)

Marinoni, Marianna; Delay, Frederick; Ackerer, Philippe; Riva, Monica; Guadagnini, Alberto

2016-08-01

We investigate the effect of considering reciprocal drawdown curves for the characterization of hydraulic properties of aquifer systems through inverse modeling based on interference well testing. Reciprocity implies that drawdown observed in a well B when pumping takes place from well A should strictly coincide with the drawdown observed in A when pumping in B with the same flow rate as in A. In this context, a critical point related to applications of hydraulic tomography is the assessment of the number of available independent drawdown data and their impact on the solution of the inverse problem. The issue arises when inverse modeling relies upon mathematical formulations of the classical single-continuum approach to flow in porous media grounded on Darcy's law. In these cases, introducing reciprocal drawdown curves in the database of an inverse problem is equivalent to duplicate some information, to a certain extent. We present a theoretical analysis of the way a Least-Square objective function and a Levenberg-Marquardt minimization algorithm are affected by the introduction of reciprocal information in the inverse problem. We also investigate the way these reciprocal data, eventually corrupted by measurement errors, influence model parameter identification in terms of: (a) the convergence of the inverse model, (b) the optimal values of parameter estimates, and (c) the associated estimation uncertainty. Our theoretical findings are exemplified through a suite of computational examples focused on block-heterogeneous systems with increased complexity level. We find that the introduction of noisy reciprocal information in the objective function of the inverse problem has a very limited influence on the optimal parameter estimates. Convergence of the inverse problem improves when adding diverse (nonreciprocal) drawdown series, but does not improve when reciprocal information is added to condition the flow model. The uncertainty on optimal parameter estimates is influenced by the strength of measurement errors and it is not significantly diminished or increased by adding noisy reciprocal information.

Incidence of dentinal defects after preparation of severely curved root canals using the Reciproc single-file system with and without prior creation of a glide path.

PubMed

Saber, S E D M; Schäfer, E

2016-11-01

To investigate the incidence of dentinal defects after preparation of severely curved root canals using the Reciproc single-file system with and without prior creation of a glide path. Mesial roots from extracted mandibular first molars were collected and scanned with CBCT to assess the morphology of the root canal systems. Three groups of 20 anatomically comparable specimens were generated. The control group was left unprepared, whilst the experimental groups were prepared with Reciproc R25 with and without a glide path (groups RG and R, respectively). Roots were then sectioned perpendicular to the long axis at 2, 4, 6, 8 and 10 mm from the apex, and coloured photographs of the sections at 40× were obtained. Two blinded examiners registered the presence of dentinal defects twice at 2-week interval. Data were statistically analysed using the Fisher exact and Cochran's Q tests. No defects were observed in the control group. The overall incidence of dentinal defects was 26% in group R and 24% in group RG, with no significant differences between them (P > 0.05). Dentinal defects occurred significantly more often in the middle and coronal thirds compared to the apical third of the canals (P < 0.05). Prior preparation of a glide path had no impact on the incidence of dentinal defects when using Reciproc files. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Deterministic photon-emitter coupling in chiral photonic circuits.

PubMed

Söllner, Immo; Mahmoodian, Sahand; Hansen, Sofie Lindskov; Midolo, Leonardo; Javadi, Alisa; Kiršanskė, Gabija; Pregnolato, Tommaso; El-Ella, Haitham; Lee, Eun Hye; Song, Jin Dong; Stobbe, Søren; Lodahl, Peter

2015-09-01

Engineering photon emission and scattering is central to modern photonics applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine photons to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with photons in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that photon emission and scattering may become directional. Here we show that the helicity of the optical transition of a quantum emitter determines the direction of single-photon emission in a specially engineered photonic-crystal waveguide. We observe single-photon emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted photons are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional photon emission for experimentally achievable on-chip non-reciprocal photonic elements. These may serve as key building blocks for single-photon optical diodes, transistors and deterministic quantum gates. Furthermore, chiral photonic circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological photon states and could be applied for directional steering of light.

Deterministic photon-emitter coupling in chiral photonic circuits

NASA Astrophysics Data System (ADS)

Söllner, Immo; Mahmoodian, Sahand; Hansen, Sofie Lindskov; Midolo, Leonardo; Javadi, Alisa; Kiršanskė, Gabija; Pregnolato, Tommaso; El-Ella, Haitham; Lee, Eun Hye; Song, Jin Dong; Stobbe, Søren; Lodahl, Peter

2015-09-01

Engineering photon emission and scattering is central to modern photonics applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine photons to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with photons in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that photon emission and scattering may become directional. Here we show that the helicity of the optical transition of a quantum emitter determines the direction of single-photon emission in a specially engineered photonic-crystal waveguide. We observe single-photon emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted photons are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional photon emission for experimentally achievable on-chip non-reciprocal photonic elements. These may serve as key building blocks for single-photon optical diodes, transistors and deterministic quantum gates. Furthermore, chiral photonic circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological photon states and could be applied for directional steering of light.

Geography as destiny? Social and ecological resilience in rangelands of the American southwest

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods: Social-ecological systems perspectives focus on the reciprocal relationships between human and natural ecosystem elements and how these interactions determine human well-being, ecological state change, and land use change. In the arid southwestern US, which is dominated...

A Single Base Difference between Pit-1 Binding Sites at the hGH Promoter and Locus Control Region Specifies Distinct Pit-1 Conformations and Functions

PubMed Central

Shewchuk, Brian M.; Ho, Yugong; Liebhaber, Stephen A.; Cooke, Nancy E.

2006-01-01

Activation of the human growth hormone (hGH-N) gene in pituitary somatotropes is mediated by a locus control region (LCR). This LCR is composed of DNase I-hypersensitive sites (HS) located −14.5 kb to −32 kb relative to the hGH-N promoter. HSI, at −14.5 kb, is the dominant determinant of hGH-N expression and is essential for establishment of a 32-kb domain of histone acetylation that encompasses the active hGH locus. This activity is conferred by three binding sites for the POU domain transcription factor Pit-1. These Pit-1 elements are sufficient to activate hGH-N expression in the mouse pituitary. In contrast, Pit-1 sites at the hGH-N promoter are consistently unable to mediate similar activity. In the present study, we demonstrate that the functional difference between the promoter-proximal and the HSI Pit-1 binding sites can be attributed in part to a single base difference. This base affects the conformation of the Pit-1/DNA complex, and reciprocal exchange of the divergent bases between the two sets of Pit-1 elements results in a partial reversal of their transgenic activities. These data support a model in which the Pit-1 binding sites in the hGH LCR allosterically program the bound Pit-1 complex for chromatin activating functions. PMID:16914737

A microfluidic reciprocating intracochlear drug delivery system with reservoir and active dose control

PubMed Central

Kim, Ernest S.; Gustenhoven, Erich; Mescher, Mark J.; Pararas, Erin E. Leary; Smith, Kim A.; Spencer, Abigail J.; Tandon, Vishal; Borenstein, Jeffrey T.; Fiering, Jason

2014-01-01

Reciprocating microfluidic drug delivery, as compared to steady or pulsed infusion, has unique features which may be advantageous in many therapeutic applications. We have previously described a device, designed for wearable use in small animal models, which periodically infuses then withdraws a sub-microliter volume of drug solution to and from the endogenous fluid of the inner ear. This delivery approach results in zero net volume of liquid transfer while enabling mass transport of compounds to the cochlea by means of diffusion and mixing. We report here on an advanced wearable delivery system aimed at further miniaturization and complex dose protocols. Enhancements to the system include the incorporation of a planar micropump to generate reciprocating flow and a novel drug reservoir which maintains zero net volume delivery and permits programmable modulation of the drug concentration in the infused bolus. The reciprocating pump is fabricated from laminated polymer films and employs a miniature electromagnetic actuator to meet the size and weight requirements of a head-mounted in vivo guinea pig testing system. The reservoir comprises a long microchannel in series with a micropump, connected in parallel with the reciprocating flow network. We characterized in vitro the response and repeatability of the planar pump and compared the results with a lumped element simulation. We also characterized the performance of the reservoir, including repeatability of dosing and range of dose modulation. Acute in vivo experiments were performed in which the reciprocating pump was used to deliver a test compound to the cochlea of anesthetized guinea pigs to evaluate short-term safety and efficacy of the system. These advances are key steps toward realization of an implantable device for long-term therapeutic applications in humans. PMID:24302432

External calibration of polarimetric radars using point and distributed targets

NASA Technical Reports Server (NTRS)

Yueh, S. H.; Kong, J. A.; Shin, R. T.

1991-01-01

Polarimetric calibration algorithms using combinations of point targets and reciprocal distributed targets are developed. From the reciprocity relations of distributed targets, and equivalent point target response is derived. Then the problem of polarimetric calibration using two point targets and one distributed target reduces to that using three point targets, which has been previously solved. For calibration using one point target and one reciprocal distributed target, two cases are analyzed with the point target being a trihedral reflector or a polarimetric active radar calibrator (PARC). For both cases, the general solutions of the system distortion matrices are written as a product of a particular solution and a matrix with one free parameter. For the trihedral-reflector case, this free parameter is determined by assuming azimuthal symmetry for the distributed target. For the PARC case, knowledge of one ratio of two covariance matrix elements of the distributed target is required to solve for the free parameter. Numerical results are simulated to demonstrate the usefulness of the developed algorithms.

External calibration of polarimetric radars using point and distributed targets

NASA Astrophysics Data System (ADS)

Yueh, S. H.; Kong, J. A.; Shin, R. T.

1991-08-01

Polarimetric calibration algorithms using combinations of point targets and reciprocal distributed targets are developed. From the reciprocity relations of distributed targets, and equivalent point target response is derived. Then the problem of polarimetric calibration using two point targets and one distributed target reduces to that using three point targets, which has been previously solved. For calibration using one point target and one reciprocal distributed target, two cases are analyzed with the point target being a trihedral reflector or a polarimetric active radar calibrator (PARC). For both cases, the general solutions of the system distortion matrices are written as a product of a particular solution and a matrix with one free parameter. For the trihedral-reflector case, this free parameter is determined by assuming azimuthal symmetry for the distributed target. For the PARC case, knowledge of one ratio of two covariance matrix elements of the distributed target is required to solve for the free parameter. Numerical results are simulated to demonstrate the usefulness of the developed algorithms.

Evaluation of instrumentation systems in reducing E. faecalis from root canals: TF adaptive and ProTaper next versus single file systems.

PubMed

Karataş, Ertuğrul; Gültekin, Esra; Arslan, Hakan; Kirici, Damla Özsu; Alsancak, Meltem; Topçu, Meltem Çolak

2015-03-01

To compare the effect of the TF Adaptive, ProTaper Next, OneShape, WaveOne, Reciproc, (SAF) on the reduction of E. faecalis in experimentally infected root canals. 70 human mandibular incisor teeth with straight roots and single root canals were selected for this experiment and the root canals of the selected teeth were infected with E. faecalis. After contamination, all the root canals were randomly divided into 7 groups: control, ProTaper Next, TF Adaptive, SAF, WaveOne, Reciproc, and OneShape. After the irrigation procedures, samples were taken from root canals with paper points and incubated in blood agar plates. The colonies grown on the blood agar were counted and interpreted as colony forming units per milliliter. Analysis of results showed that all instrumentation systems were more effective in reducing the number of bacteria than the control (P<.001). The ProTaper Next, TF Adaptive, WaveOne, Reciproc, and OneShape systems were significantly more effective than the SAF system in reducing E. faecalis within the root canals (P<.001). All instrumentation systems used in this study provided a significant reduction in bacterial populations.

Reciprocal Modulation of IK1–INa Extends Excitability in Cardiac Ventricular Cells

PubMed Central

Varghese, Anthony

2016-01-01

The inwardly rectifying potassium current (IK1) and the fast inward sodium current (INa) are reciprocally modulated in mammalian ventricular myocytes. An increase in the expression of channels responsible for one of these two currents results in a corresponding increase in expression of the other. These currents are critical in the propagation of action potentials (AP) during the normal functioning of the heart. This study identifies a physiological role for IK1–INa reciprocal modulation in ventricular fiber activation thresholds and conduction. Simulations of action potentials in single cells and propagating APs in cardiac fibers were carried out using an existing model of electrical activity in cardiac ventricular myocytes. The conductances, GK1, of the inwardly rectifying potassium current, and GNa, of the fast inward sodium current were modified independently and in tandem to simulate reciprocal modulation. In single cells, independent modulation of GK1 alone resulted in changes in activation thresholds that were qualitatively similar to those for reciprocal GK1–GNa modulation and unlike those due to independent modulation of GNa alone, indicating that GK1 determines the cellular activation threshold. On the other hand, the variations in conduction velocity in cardiac cell fibers were similar for independent GNa modulation and for tandem changes in GK1–GNa, suggesting that GNa is primarily responsible for setting tissue AP conduction velocity. Conduction velocity dependence on GK1–GNa is significantly affected by the intercellular gap junction conductance. While the effects on the passive fiber space constant due to changes in both GK1 and the intercellular gap junction conductance, Ggj, were in line with linear cable theory predictions, both conductances had surprisingly large effects on fiber activation thresholds. Independent modulation of GK1 rendered cardiac fibers inexcitable at higher levels of GK1 whereas tandem GK1–GNa changes allowed fibers to remain excitable at high GK1 values. Reciprocal modulation of the inwardly rectifying potassium current and the fast inward sodium current may have a functional role in allowing cardiac tissue to remain excitable when IK1 is upregulated. PMID:27895596

Phase coexistence and domain configuration in Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 single crystal revealed by synchrotron-based X-ray diffractive three-dimensional reciprocal space mapping and piezoresponse force microscopy

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

Wang, Ruixue; Xu, Han; Yang, Bin

The crystalline phases and domain configuration in the morphotropic phase boundary composition Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 (PMN-0.34PT) single crystal have been investigated by synchrotronbased X-ray 3D Reciprocal Space Mapping (3D-RSM) and Piezoresponse Force Microscopy. The coexistence of tetragonal (T) and monoclinic MC phases in this PMN-0.34PT single crystal is confirmed. The affiliation of each diffraction spot in the 3D-RSM was identified with the assistance of qualitative simulation. Most importantly, the twinning structure between different domains in such a mixed phase PMN-PT crystal is firmly clarified, and the spatial distribution of different twin domains is demonstrated. In addition, the lattice parameters of T andmore » MC phases in PMN-0.34PT single crystal as well as the tilting angles of crystal lattices caused by the interfacial lattice mismatch are determined.« less

Game theory and reciprocity in some extensive form experimental games.

PubMed

McCabe, K A; Rassenti, S J; Smith, V L

1996-11-12

We examine decision making in two-person extensive form game trees using nine treatments that vary matching protocol, payoffs, and payoff information. Our objective is to establish replicable principles of cooperative versus noncooperative behavior that involve the use of signaling, reciprocity, and backward induction strategies, depending on the availability of dominated direct punishing strategies and the probability of repeated interaction with the same partner. Contrary to the predictions of game theory, we find substantial support for cooperation under complete information even in various single-play treatments.

Effect of atmospheric anisoplanatism on earth-to-satellite time transfer over laser communication links.

PubMed

Belmonte, Aniceto; Taylor, Michael T; Hollberg, Leo; Kahn, Joseph M

2017-07-10

The need for an accurate time reference on orbiting platforms motivates study of time transfer via free-space optical communication links. The impact of atmospheric turbulence on earth-to-satellite optical time transfer has not been fully characterized, however. We analyze limits to two-way laser time transfer accuracy posed by anisoplanatic non-reciprocity between uplink and downlink. We show that despite limited reciprocity, two-way time transfer can still achieve sub-picosecond accuracy in realistic propagation scenarios over a single satellite visibility period.

A novel multi-detection technique for three-dimensional reciprocal-space mapping in grazing-incidence X-ray diffraction.

PubMed

Schmidbauer, M; Schäfer, P; Besedin, S; Grigoriev, D; Köhler, R; Hanke, M

2008-11-01

A new scattering technique in grazing-incidence X-ray diffraction geometry is described which enables three-dimensional mapping of reciprocal space by a single rocking scan of the sample. This is achieved by using a two-dimensional detector. The new set-up is discussed in terms of angular resolution and dynamic range of scattered intensity. As an example the diffuse scattering from a strained multilayer of self-assembled (In,Ga)As quantum dots grown on GaAs substrate is presented.

Promised and Delivered Inducements and Contributions: An Integrated View of Psychological Contract Appraisal

ERIC Educational Resources Information Center

Lambert, Lisa Schurer

2011-01-01

The reciprocal exchange of employees' work for pay that is central to employment relationships is viewed here through the lens of the psychological contract. A psychological contract involves promised inducements, promised contributions, delivered inducements, and delivered contributions: How an employee cognitively integrates these 4 elements is…

Neurons the decision makers, Part I: The firing function of a single neuron.

PubMed

Saaty, Thomas

2017-02-01

This paper is concerned with understanding synthesis of electric signals in the neural system based on making pairwise comparisons. Fundamentally, every person and every animal are born with the talent to compare stimuli from things that share properties in space or over time. Comparisons always need experience to distinguish among things. Pairwise comparisons are numerically reciprocal. If a value is assigned to the larger of two elements that have a given property when compared with the smaller one, then the smaller has the reciprocal of that value when compared with the larger. Because making comparisons requires the reciprocal property, we need mathematics that can cope with division. There are four division algebras that would allow us to use our reciprocals arising from comparisons: The real numbers, the complex numbers, the non-commutative quaternions and the non-associative octonions. Rather than inferring function as from electric flow in a network, in this paper we infer the flow from function. Neurons fire in response to stimuli and their firings vary relative to the intensities of the stimuli. We believe neurons use some kind of pairwise comparison mechanism to determine when to fire based on the stimuli they receive. The ideas we develop here about flows are used to deduce how a system based on this kind of firing determination works and can be described. Furthermore the firing of neurons requires continuous comparisons. To develop a formula describing the output of these pairwise comparisons requires solving Fredholm's equation of the second kind which is satisfied if and only if a simple functional equation has solutions. The Fourier transform of the real solution of this equation leads to inverse square laws like those that are common in physics. The Fourier transform applied to a complex valued solution leads to Dirac type of firings. Such firings are dense in the very general fields of functions known as Sobolev spaces and thus can be used to represent the very diverse phenomena in and around us. The non-commutative solution in quaternions can be interpreted as rotations in space. The also non-commutative and non-associative solution in octonions has yet to be adequately interpreted outside physics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of retreatment ability of full-sequence reciprocating instrumentation and 360° rotary instrumentation.

PubMed

Capar, Ismail Davut; Gok, Tuba; Orhan, Ezgi

2015-12-01

The purpose of the present study was to investigate the amount of root canal filling material after root canal filling removal with 360° rotary instrumentation or reciprocating motion with the same file sequence. Root canals of the 36 mandibular premolars were shaped with ProTaper Universal instruments up to size F2 and filled with corresponding single gutta-percha cone and sealer. The teeth were assigned to two retreatment groups (n = 18): group 1 360° rotational motion and group 2 reciprocating motion of ATR Tecnika motors (1310° clockwise and 578° counterclockwise). Retreatment procedure was performed with ProTaper Universal retreatment files with a sequence of D1-3 and ProTaper Universal F3 instruments. Total time required to remove filling material were recorded. Remaining filling material was examined under stereomicroscope at ×8 magnification. The data were analysed statistically using the Mann-Whitney U test, and testing was performed at 95 % confidence level (p < 0.05). There were no significant differences between the groups (p > 0.05) in terms of remaining filling material. The total time required for retreatment was shorter in 360° rotational motion group compared to reciprocating motion group (p < 0.05). Both continuous rotation and reciprocating motion showed similar effectiveness in terms of root canal filling material removal. Using ProTaper Universal retreatment instruments with reciprocating motion of ATR motor and conventional rotary motion have similar efficacy in root canal filling removal.

Effects of Glide Path on the Centering Ability and Preparation Time of Two Reciprocating Instruments

PubMed Central

Coelho, Marcelo Santos; Fontana, Carlos Eduardo; Kato, Augusto Shoji; de Martin, Alexandre Sigrist; da Silveira Bueno, Carlos Eduardo

2016-01-01

Introduction: The aim of this in vitro study was to evaluate the effects of establishing glide path on the centering ability and preparation time of two single-file reciprocating systems in mesial root canals of mandibular molars. Methods and Materials: Sixty extracted mandibular molars with curvatures of 25-39 degrees and separate foramina for the mesiobuccal and mesiolingual canals, were divided into four groups (n=15); WaveOne+glide path; WaveOne; Reciproc+glide path and Reciproc. Non-patent canals were excluded and only one canal in each tooth was instrumented. A manual glide path was established in first and third groups with #10, 15 and 20 hand K-files. Preparation was performed with reciprocating in-and-out motion, with a 3-4 mm amplitude and slight apical pressure. Initial and final radiographs were taken to analyze the amount of dentin removed in the instrumented canals. The radiographs were superimposed with an image editing software and examined to assess discrepancies at 3-, 6- and 9-mm distances from the apex. The Kruskal-Wallis test was used for statistical analysis. The level of significance was set at 0.05. Results: Preparation in groups without glide paths was swifter than the other groups (P=0.001). However, no difference was observed regarding centering ability. Conclusion: Establishing a glide path increased the total instrumentation time for preparing curved canals with WaveOne and Reciproc instruments. Glide path had no influence on the centering ability of these systems. PMID:26843875

DISCHARGE DEVICE FOR RADIOACTIVE MATERIAL

DOEpatents

Ohlinger, L.A.

1958-09-23

A device is described fur unloading bodies of fissionable material from a neutronic reactor. It is comprised essentially of a wheeled flat car having a receptacle therein containing a liquid coolant fur receiving and cooling the fuel elements as they are discharged from the reactor, and a reciprocating plunger fur supporting the fuel element during discharge thereof prior to its being dropped into the coolant. The flat car is adapted to travel along the face of the reactor adjacent the discharge ends of the coolant tubes.

Structure characterization of MHEMT heterostructure elements with In{sub 0.4}Ga{sub 0.6}As quantum well grown by molecular beam epitaxy on GaAs substrate using reciprocal space mapping

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

Aleshin, A. N., E-mail: a.n.aleshin@mail.ru; Bugaev, A. S.; Ermakova, M. A.

2016-03-15

The crystallographic parameters of elements of a metamorphic high-electron-mobility transistor (MHEMT) heterostructure with In{sub 0.4}Ga{sub 0.6}As quantum well are determined using reciprocal space mapping. The heterostructure has been grown by molecular-beam epitaxy (MBE) on the vicinal surface of a GaAs substrate with a deviation angle of 2° from the (001) plane. The structure consists of a metamorphic step-graded buffer (composed of six layers, including an inverse step), a high-temperature buffer of constant composition, and active high-electron-mobility transistor (HEMT) layers. The InAs content in the metamorphic buffer layers varies from 0.1 to 0.48. Reciprocal space mapping has been performed for themore » 004 and 224 reflections (the latter in glancing exit geometry). Based on map processing, the lateral and vertical lattice parameters of In{sub x}Ga{sub 1–x}As ternary solid solutions of variable composition have been determined. The degree of layer lattice relaxation and the compressive stress are found within the linear elasticity theory. The high-temperature buffer layer of constant composition (on which active MHEMT layers are directly formed) is shown to have the highest (close to 100%) degree of relaxation in comparison with all other heterostructure layers and a minimum compressive stress.« less

Simulation study of a chaotic cavity transducer based virtual phased array used for focusing in the bulk of a solid material.

PubMed

Delrue, Steven; Van Den Abeele, Koen; Bou Matar, Olivier

2016-04-01

In acoustic and ultrasonic non-destructive testing techniques, it is sometimes beneficial to concentrate sound energy at a chosen location in space and at a specific instance in time, for example to improve the signal-to-noise ratio or activate the nonlinearity of damage features. Time Reversal (TR) techniques, taking advantage of the reversible character of the wave equation, are particularly suited to focus ultrasonic waves in time and space. The characteristics of the energy focusing in solid media using principles of time reversed acoustics are highly influenced by the nature and dimensions of the medium, the number of transducers and the length of the received signals. Usually, a large number of transducers enclosing the domain of interest is needed to improve the quality of the focusing. However, in the case of highly reverberant media, the number of transducers can be reduced to only one (single-channel TR). For focusing in a non-reverberant medium, which is impossible when using only one source, an adaptation of the single-channel reciprocal TR procedure has been recently suggested by means of a Chaotic Cavity Transducer (CCT), a single element transducer glued on a cavity of chaotic shape. In this paper, a CCT is used to focus elastic energy, at different times, in different points along a predefined line on the upper surface of a thick solid sample. Doing so, all focusing points can act as a virtual phased array transducer, allowing to focus in any point along the depth direction of the sample. This is impossible using conventional reciprocal TR, as you need to have access to all points in the bulk of the material for detecting signals to be used in the TR process. To asses and provide a better understanding of this concept, a numerical study has been developed, allowing to verify the basic concepts of the virtual phased array and to illustrate multi-component time reversal focusing in the bulk of a solid material. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of a glide path on apical extrusion of debris during canal preparation using single-file systems in curved canals.

PubMed

Topçuoğlu, H S; Düzgün, S; Akpek, F; Topçuoğlu, G; Aktı, A

2016-06-01

To evaluate the effect of a glide path on the amount of apically extruded debris during canal preparation using single-file systems in curved canals. Ninety extracted mandibular molar teeth were randomly assigned to six groups (n = 15 for each group) for canal instrumentation. Endodontic access cavities were prepared in each tooth. In three of the six groups, a glide path was not created whereas a glide path was created using PathFile instruments on the mesial canals of all teeth in the remaining three groups. The mesial canals of the teeth were then instrumented with the following single-file instrument systems: WaveOne, Reciproc and OneShape. Debris extruded apically during instrumentation was collected into pre-weighed Eppendorf tubes. The tubes were then stored in an incubator at 70 °C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. The data obtained were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests. The OneShape file was associated with less debris extrusion than the Reciproc and WaveOne files when canal instrumentation was performed without a glide path (P < 0.05). However, no significant difference was found between the Reciproc and WaveOne files (P > 0.05). There was no significant difference amongst the OneShape, Reciproc and WaveOne files when a glide path was created before canal preparation in curved root canals (P > 0.05). All systems extruded significantly less debris in groups with a glide path than in groups without a glide path (P < 0.05). All instruments were associated with apical extrusion of debris. Creating a glide path prior to canal instrumentation reduced the amount of apically extruded debris in curved canals. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Comparison of Apical Extrusion of Debris by Using Single-File, Full-Sequence Rotary and Reciprocating Systems

PubMed Central

Ehsani, Maryam; Harandi, Azadeh; Tavanafar, Saeid; Raoof, Maryam; Galledar, Saeedeh

2016-01-01

Objectives: During root canal preparation, apical extrusion of debris can cause inflammation, flare-ups, and delayed healing. Therefore, instrumentation techniques that cause the least extrusion of debris are desirable. This study aimed to compare apical extrusion of debris by five single-file, full-sequence rotary and reciprocating systems. Materials and Methods: One hundred twenty human mandibular premolars with similar root lengths, apical diameters, and canal curvatures were selected and randomly assigned to six groups (n=20): Reciproc R25 (25, 0.08), WaveOne Primary (25, 0.08), OneShape (25, 0.06), F360 (25, 0.04), Neoniti A1 (25, 0.08), and ProTaper Universal. Instrumentation of the root canals was performed in accordance with the manufacturers’ instructions. Each tooth's debris was collected in a pre-weighed vial. After drying the debris in an incubator, the mass was measured three times consecutively; the mean was then calculated. The preparation time by each system was also measured. For data analysis, one-way ANOVA and Games-Howell post hoc test were used. Results: The mean masses (±standard deviation) of the apical debris were as follows: 2.071±1.38mg (ProTaper Universal), 1.702±1.306mg (Neoniti A1), 1.295±0.839mg (OneShape), 1.109±0.676mg (WaveOne), 0.976±0.478mg (Reciproc) and 0.797±0.531mg (F360). Compared to ProTaper Universal, F360 generated significantly less debris (P=0.02). The ProTaper system required the longest preparation time (mean=88.6 seconds); the Reciproc (P=0.008), OneShape (P=0.006), and F360 (P=0.001) required significantly less time (P<0.05). Conclusions: All instruments caused extrusion of debris through the apex. The F360 produced significantly less debris than did the ProTaper Universal. PMID:28243300

Comparison of Apical Extrusion of Debris by Using Single-File, Full-Sequence Rotary and Reciprocating Systems.

PubMed

Ehsani, Maryam; Farhang, Robab; Harandi, Azadeh; Tavanafar, Saeid; Raoof, Maryam; Galledar, Saeedeh

2016-11-01

During root canal preparation, apical extrusion of debris can cause inflammation, flare-ups, and delayed healing. Therefore, instrumentation techniques that cause the least extrusion of debris are desirable. This study aimed to compare apical extrusion of debris by five single-file, full-sequence rotary and reciprocating systems. One hundred twenty human mandibular premolars with similar root lengths, apical diameters, and canal curvatures were selected and randomly assigned to six groups (n=20): Reciproc R25 (25, 0.08), WaveOne Primary (25, 0.08), OneShape (25, 0.06), F360 (25, 0.04), Neoniti A1 (25, 0.08), and ProTaper Universal. Instrumentation of the root canals was performed in accordance with the manufacturers' instructions. Each tooth's debris was collected in a pre-weighed vial. After drying the debris in an incubator, the mass was measured three times consecutively; the mean was then calculated. The preparation time by each system was also measured. For data analysis, one-way ANOVA and Games-Howell post hoc test were used. The mean masses (±standard deviation) of the apical debris were as follows: 2.071±1.38mg (ProTaper Universal), 1.702±1.306mg (Neoniti A1), 1.295±0.839mg (OneShape), 1.109±0.676mg (WaveOne), 0.976±0.478mg (Reciproc) and 0.797±0.531mg (F360). Compared to ProTaper Universal, F360 generated significantly less debris (P=0.02). The ProTaper system required the longest preparation time (mean=88.6 seconds); the Reciproc (P=0.008), OneShape (P=0.006), and F360 (P=0.001) required significantly less time (P<0.05). All instruments caused extrusion of debris through the apex. The F360 produced significantly less debris than did the ProTaper Universal.

Presence of Metallic Microfragments on Dentinal Walls and Instrument Defects following Root Canal Preparation.

PubMed

Solda, Caroline; Langaro, Marina C; Machado, Alessandra N; Vanni, José R; de A Decurcio, Daniel; Silva, Julio A; Estrela, Carlos; Barletta, Fernando B

2017-04-01

To determine the presence of metallic microfragments and their elemental composition in the dentinal walls of root canals following preparation using different endodontic instruments and to assess the active cutting edges of instruments with regard to structural defects. A total of 108 molar teeth were selected and prepared using different endodontic instruments. Teeth were randomly divided into nine groups of 12 teeth each, according to the instruments employed: Manual systems -K-FlexoFile, K-File, and Hedstroem; rotary systems - ProTaper Next, Mtwo, BioRaCe; and reciprocating systems - Reciproc, Unicone, and WaveOne. Both root canals and instruments were assessed using scanning electron microscopy, and the elemental composition of metallic microfragments was determined using energy-dispersive X-ray spectroscopy. Metallic microfragments were found in the groups prepared with both manual and reciprocating instruments, with no statistically significant differences between groups, thirds, or presence of metallic microfragments (p ≥ 0.05). Moreover, all groups presented structural defects in both new and used instruments; however, rotary instruments (ProTaper Next, Mtwo 702, BioRaCe) were the ones with the lowest number of defects, at statistically significant differences in comparison with other instruments (p < 0.05). The presence of metallic microfragments on dentinal walls following root canal preparation was associated with manual and reciprocating instrumentation. Furthermore, rotary instruments were the ones with the lowest number of defects. Considering the outcomes measured in this study, rotary instruments performed better than the other two groups, as they were associated with the lowest number of metallic microfragments and structural defects. During root canal preparation, operative procedures may induce changes to the root canal shape, as well as the release of metallic fragments resulting from the action of instruments on dentinal walls. Therefore, it is important to determine, among the different techniques used for this purpose, which ones are least susceptible to this occurrence.

The numerical study and comparison of radial basis functions in applications of the dual reciprocity boundary element method to convection-diffusion problems

NASA Astrophysics Data System (ADS)

Chanthawara, Krittidej; Kaennakham, Sayan; Toutip, Wattana

2016-02-01

The methodology of Dual Reciprocity Boundary Element Method (DRBEM) is applied to the convection-diffusion problems and investigating its performance is our first objective of the work. Seven types of Radial Basis Functions (RBF); Linear, Thin-plate Spline, Cubic, Compactly Supported, Inverse Multiquadric, Quadratic, and that proposed by [12], were closely investigated in order to numerically compare their effectiveness drawbacks etc. and this is taken as our second objective. A sufficient number of simulations were performed covering as many aspects as possible. Varidated against both exacts and other numerical works, the final results imply strongly that the Thin-Plate Spline and Linear type of RBF are superior to others in terms of both solutions' quality and CPU-time spent while the Inverse Multiquadric seems to poorly yield the results. It is also found that DRBEM can perform relatively well at moderate level of convective force and as anticipated becomes unstable when the problem becomes more convective-dominated, as normally found in all classical mesh-dependence methods.

Investigation of the torsional stiffness of flexible disc coupling

NASA Astrophysics Data System (ADS)

Buryy, A.; Simonovsky, V.; Obolonik, V.

2017-08-01

Calculation of flexible coupling torsional stiffness is required when analyzing the torsional vibrations of the reciprocating machinery train. While having the lowest torsional stiffness of all the elements of the train, flexible coupling has a significant influence on the natural frequencies of torsional vibration. However, considering structural complexity of coupling, precise definition of its torsional stiffness is quite a difficult task. The paper presents a method for calculating the torsional stiffness of flexible disc coupling based on the study of its finite element model response under the action of torque. The analysis of the basic parameters that quantitatively and qualitatively affect the coupling torsional stiffness has been also provided. The results of the calculation as well as model adequacy, sufficient for practical application, have been confirmed at the experimental measurement of flexible disc coupling torsional stiffness. The obtained elastic characteristics (dependences of applied torque and torsional stiffness versus twist angle) are nonlinear in the initial stage of loading. This feature should be taken into account when creating reliable mathematical models of torsional vibrations of reciprocating machinery trains containing flexible disc couplings.

Photonic crystal Fano resonances for realizing optical switches, lasers, and non-reciprocal elements

NASA Astrophysics Data System (ADS)

Bekele, Dagmawi A.; Yu, Yi; Hu, Hao; Ding, Yunhong; Sakanas, Aurimas; Ottaviano, Luisa; Semenova, Elizaveta; Oxenløwe, Leif K.; Yvind, Kresten; Mork, Jesper

2017-08-01

We present our work on photonic crystal membrane devices exploiting Fano resonance between a line-defect waveguide and a side coupled nanocavity. Experimental demonstration of fast and compact all-optical switches for wavelength-conversion is reported. It is shown how the use of an asymmetric structure in combination with cavity-enhanced nonlinearity can be used to realize non-reciprocal transmission at ultra-low power and with large bandwidth. A novel type of laser structure, denoted a Fano laser, is discussed in which one of the mirrors is based on a Fano resonance. Finally, the design, fabrication and characterization of grating couplers for efficient light coupling in and out of the indium phosphide photonic crystal platform is discussed.

On the use of the Reciprocity Gap Functional in inverse scattering with near-field data: An application to mammography

NASA Astrophysics Data System (ADS)

Delbary, Fabrice; Aramini, Riccardo; Bozza, Giovanni; Brignone, Massimo; Piana, Michele

2008-11-01

Microwave tomography is a non-invasive approach to the early diagnosis of breast cancer. However the problem of visualizing tumors from diffracted microwaves is a difficult nonlinear ill-posed inverse scattering problem. We propose a qualitative approach to the solution of such a problem, whereby the shape and location of cancerous tissues can be detected by means of a combination of the Reciprocity Gap Functional method and the Linear Sampling method. We validate this approach to synthetic near-fields produced by a finite element method for boundary integral equations, where the breast is mimicked by the axial view of two nested cylinders, the external one representing the skin and the internal one representing the fat tissue.

Comparison of Shaping Ability of 10 Rotary and Reciprocating Systems: an In Vitro Study with AutoCad.

PubMed

Rubio, Jorge; Zarzosa, José Ignacio; Pallarés, Antonio

2017-09-01

The aim of this study was to compare the cutting are, root canal anatomy preservation and non-instrumented areas of F360®, F6-SkyTaper®, Hyflex-EDM®, iRACE®, Neoniti®, O.Shape®, P.Next®, Reciproc®, Revo-S® and Wave-One-Gold® size 25 files. 300 teeth with a single straight root and a circular or elliptical root canal were divided into 10 groups (1-F360®, 2- F6-SkyTaper®, 3-Hyflex-EDM®, 4-iRACE®, 5-Neoniti®, 6-O.Shape®, 7-P.Next®, 8-Reciproc®, 9-Revo-S® and 10-Wave-One-Gold®) cut into 3 cross sections using an ultrafine cutting disc. They were photographed under a stereo microscope and preinstrumentation analyses were made before rebuilding the teeth with# 10 K- File and epoxy glue. A glide path was created with #10 and #15 K files and each group was instrumented using rotary or reciprocating systems. Cutting areas, root canal anatomy preservation and non-instrumented areas were analyzed using the AutoCAD 2015 Levene's test, the Welch´s test, and the Games-Howell´s test. The Pearson's chi-squared test was used for statistical analysis. Levene's test showed no equality of variances (P<0.05), therefore Welch´s and Games-Howell's tests were applied to cutting areas, showing significant differences in all thirds and overall (P<0.05). No differences in root canal anatomy preservation were observed (P>0.05). In non-instrumented areas, significant differences were found (P<0.05) in middle third being better in Reciproc®, Neoniti® and WaveOneGold®, and in apical thirds being higher P.Next®, Reciproc®, HyflexEDM®, Neoniti® and WaveOneGold®. In cutting area, P.Next® and Reciproc® were superior in coronal third, Neoniti® and Hyflex EDM® medially and apically and Neoniti® and Reciproc® overall. Regarding the root canal anatomy preservation, all systems were similar. For non-instrumented areas, all systems achieved similar results coronally, but Reciproc®, Neoniti® and Wave One Gold® were superior in middle third and P.Next®, Reciproc®, Hyflex EDM®, Neoniti® and Wave One Gold® were superior in apically.

Comparison of Shaping Ability of 10 Rotary and Reciprocating Systems: an In Vitro Study with AutoCad

PubMed Central

Zarzosa, José Ignacio; Pallarés, Antonio

2017-01-01

Objective The aim of this study was to compare the cutting are, root canal anatomy preservation and non-instrumented areas of F360®, F6-SkyTaper®, Hyflex-EDM®, iRACE®, Neoniti®, O.Shape®, P.Next®, Reciproc®, Revo-S® and Wave-One-Gold® size 25 files. Materials and Methods 300 teeth with a single straight root and a circular or elliptical root canal were divided into 10 groups (1-F360®, 2- F6-SkyTaper®, 3-Hyflex-EDM®, 4-iRACE®, 5-Neoniti®, 6-O.Shape®, 7-P.Next®, 8-Reciproc®, 9-Revo-S® and 10-Wave-One-Gold®) cut into 3 cross sections using an ultrafine cutting disc. They were photographed under a stereo microscope and preinstrumentation analyses were made before rebuilding the teeth with# 10 K- File and epoxy glue. A glide path was created with #10 and #15 K files and each group was instrumented using rotary or reciprocating systems. Cutting areas, root canal anatomy preservation and non-instrumented areas were analyzed using the AutoCAD 2015 Levene's test, the Welch´s test, and the Games-Howell´s test. The Pearson’s chi-squared test was used for statistical analysis. Results Levene's test showed no equality of variances (P<0.05), therefore Welch´s and Games-Howell's tests were applied to cutting areas, showing significant differences in all thirds and overall (P<0.05). No differences in root canal anatomy preservation were observed (P>0.05). In non-instrumented areas, significant differences were found (P<0.05) in middle third being better in Reciproc®, Neoniti® and WaveOneGold®, and in apical thirds being higher P.Next®, Reciproc®, HyflexEDM®, Neoniti® and WaveOneGold®. Conclusions In cutting area, P.Next® and Reciproc® were superior in coronal third, Neoniti® and Hyflex EDM® medially and apically and Neoniti® and Reciproc® overall. Regarding the root canal anatomy preservation, all systems were similar. For non-instrumented areas, all systems achieved similar results coronally, but Reciproc®, Neoniti® and Wave One Gold® were superior in middle third and P.Next®, Reciproc®, Hyflex EDM®, Neoniti® and Wave One Gold® were superior in apically. PMID:29225361

Evolution of direct reciprocity under uncertainty can explain human generosity in one-shot encounters

PubMed Central

Delton, Andrew W.; Krasnow, Max M.; Cosmides, Leda; Tooby, John

2011-01-01

Are humans too generous? The discovery that subjects choose to incur costs to allocate benefits to others in anonymous, one-shot economic games has posed an unsolved challenge to models of economic and evolutionary rationality. Using agent-based simulations, we show that such generosity is the necessary byproduct of selection on decision systems for regulating dyadic reciprocity under conditions of uncertainty. In deciding whether to engage in dyadic reciprocity, these systems must balance (i) the costs of mistaking a one-shot interaction for a repeated interaction (hence, risking a single chance of being exploited) with (ii) the far greater costs of mistaking a repeated interaction for a one-shot interaction (thereby precluding benefits from multiple future cooperative interactions). This asymmetry builds organisms naturally selected to cooperate even when exposed to cues that they are in one-shot interactions. PMID:21788489

Evolution of direct reciprocity under uncertainty can explain human generosity in one-shot encounters.

PubMed

Delton, Andrew W; Krasnow, Max M; Cosmides, Leda; Tooby, John

2011-08-09

Are humans too generous? The discovery that subjects choose to incur costs to allocate benefits to others in anonymous, one-shot economic games has posed an unsolved challenge to models of economic and evolutionary rationality. Using agent-based simulations, we show that such generosity is the necessary byproduct of selection on decision systems for regulating dyadic reciprocity under conditions of uncertainty. In deciding whether to engage in dyadic reciprocity, these systems must balance (i) the costs of mistaking a one-shot interaction for a repeated interaction (hence, risking a single chance of being exploited) with (ii) the far greater costs of mistaking a repeated interaction for a one-shot interaction (thereby precluding benefits from multiple future cooperative interactions). This asymmetry builds organisms naturally selected to cooperate even when exposed to cues that they are in one-shot interactions.

Confirmation of linear system theory prediction: Changes in Herrnstein's k as a function of changes in reinforcer magnitude.

PubMed

McDowell, J J; Wood, H M

1984-03-01

Eight human subjects pressed a lever on a range of variable-interval schedules for 0.25 cent to 35.0 cent per reinforcement. Herrnstein's hyperbola described seven of the eight subjects' response-rate data well. For all subjects, the y-asymptote of the hyperbola increased with increasing reinforcer magnitude and its reciprocal was a linear function of the reciprocal of reinforcer magnitude. These results confirm predictions made by linear system theory; they contradict formal properties of Herrnstein's account and of six other mathematical accounts of single-alternative responding.

Confirmation of linear system theory prediction: Changes in Herrnstein's k as a function of changes in reinforcer magnitude

PubMed Central

McDowell, J. J; Wood, Helena M.

1984-01-01

Eight human subjects pressed a lever on a range of variable-interval schedules for 0.25¢ to 35.0¢ per reinforcement. Herrnstein's hyperbola described seven of the eight subjects' response-rate data well. For all subjects, the y-asymptote of the hyperbola increased with increasing reinforcer magnitude and its reciprocal was a linear function of the reciprocal of reinforcer magnitude. These results confirm predictions made by linear system theory; they contradict formal properties of Herrnstein's account and of six other mathematical accounts of single-alternative responding. PMID:16812366

GAPD: a GPU-accelerated atom-based polychromatic diffraction simulation code.

PubMed

E, J C; Wang, L; Chen, S; Zhang, Y Y; Luo, S N

2018-03-01

GAPD, a graphics-processing-unit (GPU)-accelerated atom-based polychromatic diffraction simulation code for direct, kinematics-based, simulations of X-ray/electron diffraction of large-scale atomic systems with mono-/polychromatic beams and arbitrary plane detector geometries, is presented. This code implements GPU parallel computation via both real- and reciprocal-space decompositions. With GAPD, direct simulations are performed of the reciprocal lattice node of ultralarge systems (∼5 billion atoms) and diffraction patterns of single-crystal and polycrystalline configurations with mono- and polychromatic X-ray beams (including synchrotron undulator sources), and validation, benchmark and application cases are presented.

The role of the background: texture segregation and figure-ground segmentation.

PubMed

Caputo, G

1996-09-01

The effects of a texture surround composed of line elements on a stimulus within which a target line element segregates, were studied. Detection and discrimination of the target when it had the same orientation as the surround were impaired at short presentation time; on the other hand, no effect was present when they were reciprocally orthogonal. These results are interpreted as background completion in texture segregation; a texture made up of similar elements is represented as a continuous surface with contour and contrast of an embedded element inhibited. This interpretation is further confirmed with a simple line protruding from an annulus. Generally, the results are taken as evidence that local features are prevented from segmenting when they are parts of a global entity.

Ex vivo evaluation of various instrumentation techniques and irrigants in reducing E. faecalis within root canals.

PubMed

Basmaci, F; Oztan, M D; Kiyan, M

2013-09-01

To evaluate ex vivo the effectiveness of single-file instrumentation techniques compared with serial Ni-Ti rotary instrumentation with several irrigation regimens in reducing E. faecalis within root canals. A total of 81 extracted human mandibular premolar teeth with a single root canal were infected with E. faecalis before and after canal preparation. Samples were divided randomly into 9 groups, as follows: group 1-A: sterile phosphate-buffered saline + Self-adjusting file, group 1-B: 5% sodium hypochlorite + 15% EDTA + Self-adjusting file, group 1-C: 5% sodium hypochlorite + 7% maleic acid + Self-adjusting file, group 2-A: sterile phosphate-buffered saline + Reciproc (R25), group 2-B: 5% sodium hypochlorite + 15% EDTA + Reciproc (R25), group 2-C: 5% sodium hypochlorite + 7% maleic acid + Reciproc (R25), group 3-A: sterile phosphate-buffered saline + ProTaper, group 3-B: 5% sodium hypochlorite + 15% EDTA + ProTaper, group 3-C: 5% sodium hypochlorite + 7% maleic acid + ProTaper. anova was used to analyse statistically the differences in terms of reduction in colony counts between the groups, and Dunn's post hoc test was used for multiple comparisons. All techniques and irrigation regimens significantly reduced the number of bacterial cells in the root canal (P < 0.001). Comparisons amongst the groups revealed significant differences between group 1A (sterile phosphate-buffered saline + Self-adjusting file)/group 1B (5% sodium hypochlorite + 15% EDTA + Self-adjusting file) (P = 0.031), group 1A (sterile phosphate-buffered saline + Self-adjusting file)/group 2C (5% sodium hypochlorite + 7% maleic acid + Reciproc) (P = 0.003), group 2A (sterile phosphate-buffered saline + Reciproc)/group 3B (5% sodium hypochlorite + 15% EDTA + ProTaper) (P = 0.036), group 3B (5% sodium hypochlorite + 15% EDTA + ProTaper)/group 1A (sterile phosphate-buffered saline + Self-adjusting file) (P < 0.001), and group 3C (5% sodium hypochlorite + 7% maleic acid + ProTaper)/group 1A (sterile phosphate-buffered saline + Self-adjusting file) (P = 0.033). No significant differences in terms of reduction in microbial counts were observed between single-file techniques (SAF and Reciproc) and serial Ni-Ti instrumentation technique (ProTaper) in combination with irrigants. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Pain after root canal treatment with different instruments: A systematic review and meta-analysis.

PubMed

Sun, Chengjun; Sun, Jicheng; Tan, Minmin; Hu, Bo; Gao, Xiang; Song, Jinlin

2018-03-07

The aims of this systematic review were to compare the incidence and intensity of postoperative pain after single-visit root canal treatment using manual, rotary and reciprocating instruments. An extensive literature search in PubMed, EMBASE, Cochrane Library, and Web of Science was performed to identify investigations that evaluated the effects of different instruments on post-endodontic pain. Meta-analyses and additional analyses, including subgroup and sensitivity analyses, were conducted. We included seventeen trials in this study. Pooled results showed that patients treated with rotary instruments experienced a significantly lower incidence of postoperative pain (RR, 0.32, P = 0.0005) and reduced pain intensity than did patients treated with manual instruments. In addition, patients treated with multiple rotary-file systems experienced a significantly lower incidence of postoperative pain than did those treated with reciprocating systems (RR, 0.73; P < 0.0001). The use of rotary instruments contributed to a lower incidence and intensity of postoperative pain than did the use of hand files in patients who received single-visit root canal treatment. In addition, the use of multiple rotary-file systems contributed to a lower incidence of postoperative pain than did the use of reciprocating systems. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Piezohydraulic Pump Development

NASA Technical Reports Server (NTRS)

Lynch, Christopher S.

2005-01-01

Reciprocating piston piezohydraulic pumps were developed originally under the Smart Wing Phase II program (Lynch) and later under the CHAP program (CSA, Kinetic Ceramics). These pumps focused on 10 cm scale stack actuators operating below resonance and, more recently, at resonance. A survey of commercially available linear actuators indicates that obtaining power density and specific power greater than electromagnetic linear actuators requires driving the stacks at frequencies greater than 1 KHz at high fields. In the case of 10 cm scale actuators the power supply signal conditioning becomes large and heavy and the soft PZT stack actuators generate a lot of heat due to internal losses. Reciprocation frequencies can be increased and material losses significantly decreased through use of millimeter scale single crystal stack actuators. We are presently targeting the design of pumps that utilize stacks at the 1-10 mm length scale and run at reciprocating frequencies of 20kHz or greater. This offers significant advantages over current approaches including eliminating audible noise and significantly increasing the power density and specific power of the system (including electronics). The pump currently under development will comprise an LC resonant drive of a resonant crystal and head mass operating against a resonant fluid column. Each of these resonant systems are high Q and together should produce a single high Q second order system.

Phase coexistence and domain configuration in Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.34PbTiO{sub 3} single crystal revealed by synchrotron-based X-ray diffractive three-dimensional reciprocal space mapping and piezoresponse force microscopy

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

Wang, Ruixue; Yang, Bin, E-mail: binyang@hit.edu.cn; Sun, Enwei

The crystalline phases and domain configuration in the morphotropic phase boundary composition Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.34PbTiO{sub 3} (PMN-0.34PT) single crystal have been investigated by synchrotron-based X-ray 3D Reciprocal Space Mapping (3D-RSM) and Piezoresponse Force Microscopy. The coexistence of tetragonal (T) and monoclinic M{sub C} phases in this PMN-0.34PT single crystal is confirmed. The affiliation of each diffraction spot in the 3D-RSM was identified with the assistance of qualitative simulation. Most importantly, the twinning structure between different domains in such a mixed phase PMN-PT crystal is firmly clarified, and the spatial distribution of different twin domains is demonstrated. In addition, themore » lattice parameters of T and M{sub C} phases in PMN-0.34PT single crystal as well as the tilting angles of crystal lattices caused by the interfacial lattice mismatch are determined.« less

Angular dependence models for radiance to flux conversion

NASA Technical Reports Server (NTRS)

Green, Richard N.; Suttles, John T.; Wielicki, Bruce A.

1990-01-01

Angular dependence models (ADM) used for converting the measured radiance to flux at the top of the atmosphere are reviewed, and emphasis is placed on the measure of their effectiveness and the implications of requiring the ADMs to satisfy reciprocity. The overall significance of the ADMs is figured out by analyzing the same satellite data with a single Lambertian model, single mean model, and the 12 Earth Radiation Budget Experiment (ERBE) ADMs. It is shown that the Lambertian ADM is inadequate, while the mean ADM results in nearly unbiased fluxes but creates substantial differences for individual pixel fluxes. The standard ERBE ADM works well except for a 10-pct to 15-pct albedo growth across the scan; a modified ADM based on the standard ERBE ADM but forced to satisfy the principle of reciprocity increases the limb brightening and reduces the albedo growth but does not improve the scanner and nonscanner intercomparison.

Coherent manipulation of a solid-state artificial atom with few photons.

PubMed

Giesz, V; Somaschi, N; Hornecker, G; Grange, T; Reznychenko, B; De Santis, L; Demory, J; Gomez, C; Sagnes, I; Lemaître, A; Krebs, O; Lanzillotti-Kimura, N D; Lanco, L; Auffeves, A; Senellart, P

2016-06-17

In a quantum network based on atoms and photons, a single atom should control the photon state and, reciprocally, a single photon should allow the coherent manipulation of the atom. Both operations require controlling the atom environment and developing efficient atom-photon interfaces, for instance by coupling the natural or artificial atom to cavities. So far, much attention has been drown on manipulating the light field with atomic transitions, recently at the few-photon limit. Here we report on the reciprocal operation and demonstrate the coherent manipulation of an artificial atom by few photons. We study a quantum dot-cavity system with a record cooperativity of 13. Incident photons interact with the atom with probability 0.95, which radiates back in the cavity mode with probability 0.96. Inversion of the atomic transition is achieved for 3.8 photons on average, showing that our artificial atom performs as if fully isolated from the solid-state environment.

Transfer of chirality from light to a Disperse Red 1 molecular glass surface.

PubMed

Mazaheri, Leila; Lebel, Olivier; Nunzi, Jean-Michel

2017-12-01

Chiral structures and materials interact with light in well-documented ways, but light can also interact with achiral materials to generate chirality by inscribing its asymmetric configuration on photoresponsive materials, such as azobenzene derivatives. While it is thus possible to generate both two-dimensional (2D) and three-dimensional (3D) chirality, 2D chirality is especially attractive because of its non-reciprocity. Herein, 2D chirality is induced on the surface of a glass-forming Disperse Red 1 derivative by irradiation with a single laser beam, yielding crossed spontaneous surface relief gratings with different pitches. Azimuth rotations up to 10° have been observed, and the absence of 3D chirality has been confirmed. This method thus allows generating non-reciprocal planar chiral objects by a simple, single irradiation process on a thin film of a material that can easily be processed over large areas or onto small objects.

Energy gap formation mechanism through the interference phenomena of electrons in face-centered cubic elements and compounds with the emphasis on half-Heusler and Heusler compounds

NASA Astrophysics Data System (ADS)

Mizutani, U.; Sato, H.

2018-05-01

Many face-centred cubic elements and compounds with the number of atoms per unit cell N equal to 8, 12 and 16 are known to be stabilised by forming either a band gap or a pseudogap at the Fermi level. They are conveniently expressed as cF8, cF12 and cF16, respectively, in the Pearson symbol. From the cF8 family, we worked on three tetravalent elements C (diamond), Si and Ge, SZn-type AsGa compound and NaCl-type compounds like BiLu, AsSc, etc. From the cF12 family, more than 80 compounds were selected, with a particular emphasis on ABC- and half-Heusler-type ternary equiatomic compounds. Among cF16 compounds, both the Heusler compounds ABC2 and Zintl compounds were studied. We revealed that, regardless of whether or not the transition metal (TM) and/or rare-earth (RE) elements are involved as constituent elements, the energy gap formation mechanism for cF8, cF12 and cF16 compounds can be universally discussed in terms of interference phenomenon of itinerant electrons with set of reciprocal lattice planes with ? = 8, 11 and 12, where ? refers to square of the critical reciprocal of lattice vector of an fcc lattice. The number of itinerant electrons per unit cell, e/uc, for all these band gap/pseudogap-bearing compounds is found to fall on a universal line called "3/2-power law" when plotted against ? on a logarithmic scale. This proves the validity of the fulfilment of the interference condition ? in conformity with other pseudogap compounds with different crystal symmetries and different sizes of the unit cell reported in literature.

Universals and cultural diversity in the expression of gratitude.

PubMed

Floyd, Simeon; Rossi, Giovanni; Baranova, Julija; Blythe, Joe; Dingemanse, Mark; Kendrick, Kobin H; Zinken, Jörg; Enfield, N J

2018-05-01

Gratitude is argued to have evolved to motivate and maintain social reciprocity among people, and to be linked to a wide range of positive effects-social, psychological and even physical. But is socially reciprocal behaviour dependent on the expression of gratitude, for example by saying 'thank you' as in English? Current research has not included cross-cultural elements, and has tended to conflate gratitude as an emotion with gratitude as a linguistic practice, as might appear to be the case in English. Here, we ask to what extent people express gratitude in different societies by focusing on episodes of everyday life where someone seeks and obtains a good, service or support from another, comparing these episodes across eight languages from five continents. We find that expressions of gratitude in these episodes are remarkably rare, suggesting that social reciprocity in everyday life relies on tacit understandings of rights and duties surrounding mutual assistance and collaboration. At the same time, we also find minor cross-cultural variation, with slightly higher rates in Western European languages English and Italian, showing that universal tendencies of social reciprocity should not be equated with more culturally variable practices of expressing gratitude. Our study complements previous experimental and culture-specific research on gratitude with a systematic comparison of audiovisual corpora of naturally occurring social interaction from different cultures from around the world.

Universals and cultural diversity in the expression of gratitude

PubMed Central

Floyd, Simeon; Baranova, Julija; Blythe, Joe; Dingemanse, Mark; Kendrick, Kobin H.; Zinken, Jörg; Enfield, N. J.

2018-01-01

Gratitude is argued to have evolved to motivate and maintain social reciprocity among people, and to be linked to a wide range of positive effects—social, psychological and even physical. But is socially reciprocal behaviour dependent on the expression of gratitude, for example by saying ‘thank you’ as in English? Current research has not included cross-cultural elements, and has tended to conflate gratitude as an emotion with gratitude as a linguistic practice, as might appear to be the case in English. Here, we ask to what extent people express gratitude in different societies by focusing on episodes of everyday life where someone seeks and obtains a good, service or support from another, comparing these episodes across eight languages from five continents. We find that expressions of gratitude in these episodes are remarkably rare, suggesting that social reciprocity in everyday life relies on tacit understandings of rights and duties surrounding mutual assistance and collaboration. At the same time, we also find minor cross-cultural variation, with slightly higher rates in Western European languages English and Italian, showing that universal tendencies of social reciprocity should not be equated with more culturally variable practices of expressing gratitude. Our study complements previous experimental and culture-specific research on gratitude with a systematic comparison of audiovisual corpora of naturally occurring social interaction from different cultures from around the world. PMID:29892463

Reciprocal chromosome painting shows that the great difference in diploid number between human and African green monkey is mostly due to non-Robertsonian fissions.

PubMed

Finelli, P; Stanyon, R; Plesker, R; Ferguson-Smith, M A; O'Brien, P C; Wienberg, J

1999-07-01

We used reciprocal chromosome painting with both African green monkey (C. aethiops) and human chromosome specific DNA probes to delineate homologous regions in the two species. Probes were derived by fluorescence-activated chromosome flow sorting and then were reciprocally hybridized to metaphase spreads of each species. Segments in the size range of a single chromosome band were identified, demonstrating the sensitivity of the approach when comparing species that diverged more than 20 million years ago. Outgroup analysis shows that the great difference in diploid numbers between the African green monkey (2n = 60) and humans (2n = 46) is mainly owing to fissions, and the direction of change is towards increasing diploid numbers. However, most break points apparently lie outside of the centromere regions, suggesting that the changes were not solely Robertsonian as has been previously assumed. No reciprocal translocations have occurred in the phylogenetic lines leading to humans or African green monkeys. The primate paints established here are a valuable tool to establish interspecies homology, to define rearrangements, and to determine the mechanisms of chromosomal evolution in primate species.

Photometric study of single-shot energy-dispersive x-ray diffraction at a laser plasma facility

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

Hoidn, O. R.; Seidler, G. T., E-mail: seidler@uw.edu

The low repetition rates and possible shot-to-shot variations in laser-plasma studies place a high value on single-shot diagnostics. For example, white-beam scattering methods based on broadband backlighter x-ray sources are used to determine changes in the structure of laser-shocked crystalline materials by the evolution of coincidences of reciprocal lattice vectors and kinematically allowed momentum transfers. Here, we demonstrate that white-beam techniques can be extended to strongly disordered dense plasma and warm dense matter systems where reciprocal space is only weakly structured and spectroscopic detection is consequently needed to determine the static structure factor and thus, the ion-ion radial distribution function.more » Specifically, we report a photometric study of energy-dispersive x-ray diffraction (ED-XRD) for structural measurement of high energy density systems at large-scale laser facilities such as OMEGA and the National Ignition Facility. We find that structural information can be obtained in single-shot ED-XRD experiments using established backlighter and spectrometer technologies.« less

A combined temperature-dependent electron and single-crystal X-ray diffraction study of the fresnoite compound Rb 2V 4+V 25+O 8

NASA Astrophysics Data System (ADS)

Withers, Ray L.; Höche, Thomas; Liu, Yun; Esmaeilzadeh, Saeid; Keding, Ralf; Sales, Brian

2004-10-01

High-purity Rb2V3O8 has been grown and temperature-dependent electron and single-crystal X-ray diffraction used to carefully investigate its fresnoite-type reciprocal lattice. In contrast to other recently investigated representatives of the fresnoite family of compounds, Rb2V3O8 is not incommensurately modulated with an incommensurate basal plane primary modulation wave vector given by q∼0.3 <110>*. A careful low-temperature electron diffraction study has, however, revealed the existence of weak incommensurate satellite reflections characterized by the primitive primary modulation wave vector q1∼0.16c*. The reciprocal space positioning of these incommensurate satellite reflections, the overall (3+1)-d superspace group symmetry, as well as the shapes of the refined displacement ellipsoids determined from single-crystal XRD refinement, are all consistent with their arising from a distinct type of condensed rigid unit modes (RUMs) of distortion of the Rb2V3O8 parent structure.

Finding Common Ground: Coordinating Housing and Education Policy to Promote Integration

ERIC Educational Resources Information Center

Tegeler, Philip, Ed.

2011-01-01

The powerful, reciprocal connection between school and housing segregation has long been recognized. The housing-school link was a key element in both the 1968 Kerner Commission Report and in the legislative history of the Fair Housing Act. The relation of school and housing segregation was also explored in a series of school desegregation cases…

Stabilizing gas bearing in free piston machines

NASA Technical Reports Server (NTRS)

Dhar, Manmohan (Inventor)

1992-01-01

In a free piston engine, to reduce dynamic loads on the reciprocating elements caused by a time varying pressure gradient across the gas bearing and close clearance seals provided therein, drain galleries are incorporated at the ends of the gas bearings to isolate the same, and circumferentially spaced grooves are incorporated in the close clearance seal region.

Landmine detection using two-tapped joint orthogonal matching pursuits

NASA Astrophysics Data System (ADS)

Goldberg, Sean; Glenn, Taylor; Wilson, Joseph N.; Gader, Paul D.

2012-06-01

Joint Orthogonal Matching Pursuits (JOMP) is used here in the context of landmine detection using data obtained from an electromagnetic induction (EMI) sensor. The response from an object containing metal can be decomposed into a discrete spectrum of relaxation frequencies (DSRF) from which we construct a dictionary. A greedy iterative algorithm is proposed for computing successive residuals of a signal by subtracting away the highest matching dictionary element at each step. The nal condence of a particular signal is a combination of the reciprocal of this residual and the mean of the complex component. A two-tap approach comparing signals on opposite sides of the geometric location of the sensor is examined and found to produce better classication. It is found that using only a single pursuit does a comparable job, reducing complexity and allowing for real-time implementation in automated target recognition systems. JOMP is particularly highlighted in comparison with a previous EMI detection algorithm known as String Match.

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

Lan, Chune; Xue, Jianming; Zhang, Yanwen

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (< {approx} 25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation schememore » is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.« less

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

Lan, Chune; Xue, Jianming; Zhang, Yanwen

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (<25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developedmore » to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.« less

Finite Element Study on Continuous Rotating versus Reciprocating Nickel-Titanium Instruments.

PubMed

El-Anwar, Mohamed I; Yousief, Salah A; Kataia, Engy M; El-Wahab, Tarek M Abd

2016-01-01

In the present study, GTX and ProTaper as continuous rotating endodontic files were numerically compared with WaveOne reciprocating file using finite element analysis, aiming at having a low cost, accurate/trustworthy comparison as well as finding out the effect of instrument design and manufacturing material on its lifespan. Two 3D finite element models were especially prepared for this comparison. Commercial engineering CAD/CAM package was used to model full detailed flute geometries of the instruments. Multi-linear materials were defined in analysis by using real strain-stress data of NiTi and M-Wire. Non-linear static analysis was performed to simulate the instrument inside root canal at a 45° angle in the apical portion and subjected to 0.3 N.cm torsion. The three simulations in this study showed that M-Wire is slightly more resistant to failure than conventional NiTi. On the other hand, both materials are fairly similar in case of severe locking conditions. For the same instrument geometry, M-Wire instruments may have longer lifespan than the conventional NiTi ones. In case of severe locking conditions both materials will fail similarly. Larger cross sectional area (function of instrument taper) resisted better to failure than the smaller ones, while the cross sectional shape and its cutting angles could affect instrument cutting efficiency.

Hamiltonian Monte Carlo Inversion of Seismic Sources in Complex Media

NASA Astrophysics Data System (ADS)

Fichtner, A.; Simutė, S.

2017-12-01

We present a probabilistic seismic source inversion method that properly accounts for 3D heterogeneous Earth structure and provides full uncertainty information on the timing, location and mechanism of the event. Our method rests on two essential elements: (1) reciprocity and spectral-element simulations in complex media, and (2) Hamiltonian Monte Carlo sampling that requires only a small amount of test models. Using spectral-element simulations of 3D, visco-elastic, anisotropic wave propagation, we precompute a data base of the strain tensor in time and space by placing sources at the positions of receivers. Exploiting reciprocity, this receiver-side strain data base can be used to promptly compute synthetic seismograms at the receiver locations for any hypothetical source within the volume of interest. The rapid solution of the forward problem enables a Bayesian solution of the inverse problem. For this, we developed a variant of Hamiltonian Monte Carlo (HMC) sampling. Taking advantage of easily computable derivatives, HMC converges to the posterior probability density with orders of magnitude less samples than derivative-free Monte Carlo methods. (Exact numbers depend on observational errors and the quality of the prior). We apply our method to the Japanese Islands region where we previously constrained 3D structure of the crust and upper mantle using full-waveform inversion with a minimum period of around 15 s.

Shaping ability of single-file reciprocating and heat-treated multifile rotary systems: a micro-CT study.

PubMed

Marceliano-Alves, M F V; Sousa-Neto, M D; Fidel, S R; Steier, L; Robinson, J P; Pécora, J D; Versiani, M A

2015-12-01

To investigate changes in three-dimensional geometry, in various cross-sectional morphological parameters and in the centring ability of root canals prepared with different preparation systems using microcomputed tomographic imaging technology. Sixty-four mesial canals of mandibular molars were matched based on similar morphological dimensions using micro-CT evaluation and assigned to four experimental groups (n = 16), according to the canal preparation technique: Reciproc, WaveOne, Twisted File and HyFlex CM systems. Changes in several 2D (area, perimeter, form factor, roundness, minor and major diameter) and 3D [volume, surface area, structure model index (SMI)] morphological parameters, as well as canal transportation, were compared with preoperative values using Kruskal-Wallis and anovapost hoc Tukey's tests with the significance level set at 5%. Preparation significantly increased all tested parameters in the experimental groups. No significant differences were observed between groups regarding changes in volume, surface area, SMI, form factor and roundness of the root canal after preparation (P > 0.05). In the apical third, the Reciproc group had significantly greater changes in canal area, perimeter, major and minor diameters than the other groups (P < 0.05). Overall, the Twisted File and HyFlex CM systems were associated with significantly less transportation than the reciprocating instruments, Reciproc and WaveOne (P < 0.05). Shaping procedures led to the enlargement of the root canal space with no evidence of significant preparation errors. Changes in 3D parameters were not different between groups whilst, in the apical third, Reciproc was associated with significantly greater changes in several 2D parameters compared to the other groups. Twisted File and HyFlex CM systems were able to maintain the original canal anatomy with less canal transportation than Reciproc and WaveOne; however, these differences are unlikely to be of clinical significance. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Remote detection of single emitters via optical waveguides

NASA Astrophysics Data System (ADS)

Then, Patrick; Razinskas, Gary; Feichtner, Thorsten; Haas, Philippe; Wild, Andreas; Bellini, Nicola; Osellame, Roberto; Cerullo, Giulio; Hecht, Bert

2014-05-01

The integration of lab-on-a-chip technologies with single-molecule detection techniques may enable new applications in analytical chemistry, biotechnology, and medicine. We describe a method based on the reciprocity theorem of electromagnetic theory to determine and optimize the detection efficiency of photons emitted by single quantum emitters through truncated dielectric waveguides of arbitrary shape positioned in their proximity. We demonstrate experimentally that detection of single quantum emitters via such waveguides is possible, confirming the predicted behavior of the detection efficiency. Our findings blaze the trail towards efficient lensless single-emitter detection compatible with large-scale optofluidic integration.

Evaluation of apically extruded debris during root canal retreatment with several NiTi systems.

PubMed

Dincer, A N; Er, O; Canakci, B C

2015-12-01

To compare the amount of debris extruded apically during root canal retreatment using ProTaper, Mtwo and Reciproc instruments with hand H-files. In total, 60 freshly extracted human mandibular incisor teeth were used. All root canals were prepared with a Reciproc R25 file than filled with Gutta-percha and AH Plus sealer using cold lateral condensation before being assigned randomly to four groups (n = 15 each). In group 1, root fillings were removed with the Protaper Universal retreatment system; ProTaper Universal F3 and F4 instruments were used for the final preparation. In group 2, root fillings were removed with the Mtwo retreatment system; Mtwo size 30, .06 taper, size 35, .06 taper and size 40, .06 taper files were used for the final preparation. In group 3, root fillings were removed with Reciproc R25 instruments; Reciproc R40 instruments were used for the final preparation. In group 4, the root fillings were removed with Gates Glidden burs and sizes 35, 30 and 25 H-files; for final preparation, a size 40 H-file was used. Glass vials were used for debris collection. The vials were weighed before and after Gutta-percha removal. Additionally, the times required for the retreatment procedures were recorded. Data were analysed statistically using one-way analysis of variance. The Reciproc system produced significantly smaller amounts of apical extruded debris than the other groups (P < 0.05). There was no significant difference between the Mtwo, H-file and ProTaper groups. The ProTaper and Reciproc groups required significantly less time than the Mtwo and H-file groups (P < 0.001). Use of the reciprocating single file system resulted in the extrusion of significantly less debris compared with the full-sequence rotary NiTi instruments and hand filing. Use of the ProTaper and Reciproc instruments required less time for retreatment procedures than use of the Mtwo or H-file. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Establishment of high reciprocal connectivity between clonal cortical neurons is regulated by the Dnmt3b DNA methyltransferase and clustered protocadherins.

PubMed

Tarusawa, Etsuko; Sanbo, Makoto; Okayama, Atsushi; Miyashita, Toshio; Kitsukawa, Takashi; Hirayama, Teruyoshi; Hirabayashi, Takahiro; Hasegawa, Sonoko; Kaneko, Ryosuke; Toyoda, Shunsuke; Kobayashi, Toshihiro; Kato-Itoh, Megumi; Nakauchi, Hiromitsu; Hirabayashi, Masumi; Yagi, Takeshi; Yoshimura, Yumiko

2016-12-02

The specificity of synaptic connections is fundamental for proper neural circuit function. Specific neuronal connections that underlie information processing in the sensory cortex are initially established without sensory experiences to a considerable extent, and then the connections are individually refined through sensory experiences. Excitatory neurons arising from the same single progenitor cell are preferentially connected in the postnatal cortex, suggesting that cell lineage contributes to the initial wiring of neurons. However, the postnatal developmental process of lineage-dependent connection specificity is not known, nor how clonal neurons, which are derived from the same neural stem cell, are stamped with the identity of their common neural stem cell and guided to form synaptic connections. We show that cortical excitatory neurons that arise from the same neural stem cell and reside within the same layer preferentially establish reciprocal synaptic connections in the mouse barrel cortex. We observed a transient increase in synaptic connections between clonal but not nonclonal neuron pairs during postnatal development, followed by selective stabilization of the reciprocal connections between clonal neuron pairs. Furthermore, we demonstrate that selective stabilization of the reciprocal connections between clonal neuron pairs is impaired by the deficiency of DNA methyltransferase 3b (Dnmt3b), which determines DNA-methylation patterns of genes in stem cells during early corticogenesis. Dnmt3b regulates the postnatal expression of clustered protocadherin (cPcdh) isoforms, a family of adhesion molecules. We found that cPcdh deficiency in clonal neuron pairs impairs the whole process of the formation and stabilization of connections to establish lineage-specific connection reciprocity. Our results demonstrate that local, reciprocal neural connections are selectively formed and retained between clonal neurons in layer 4 of the barrel cortex during postnatal development, and that Dnmt3b and cPcdhs are required for the establishment of lineage-specific reciprocal connections. These findings indicate that lineage-specific connection reciprocity is predetermined by Dnmt3b during embryonic development, and that the cPcdhs contribute to postnatal cortical neuron identification to guide lineage-dependent synaptic connections in the neocortex.

Reciprocal synapses between outer hair cells and their afferent terminals: evidence for a local neural network in the mammalian cochlea.

PubMed

Thiers, Fabio A; Nadol, Joseph B; Liberman, M Charles

2008-12-01

Cochlear outer hair cells (OHCs) serve both as sensory receptors and biological motors. Their sensory function is poorly understood because their afferent innervation, the type-II spiral ganglion cell, has small unmyelinated axons and constitutes only 5% of the cochlear nerve. Reciprocal synapses between OHCs and their type-II terminals, consisting of paired afferent and efferent specialization, have been described in the primate cochlea. Here, we use serial and semi-serial-section transmission electron microscopy to quantify the nature and number of synaptic interactions in the OHC area of adult cats. Reciprocal synapses were found in all OHC rows and all cochlear frequency regions. They were more common among third-row OHCs and in the apical half of the cochlea, where 86% of synapses were reciprocal. The relative frequency of reciprocal synapses was unchanged following surgical transection of the olivocochlear bundle in one cat, confirming that reciprocal synapses were not formed by efferent fibers. In the normal ear, axo-dendritic synapses between olivocochlear terminals and type-II terminals and/or dendrites were as common as synapses between olivocochlear terminals and OHCs, especially in the first row, where, on average, almost 30 such synapses were seen in the region under a single OHC. The results suggest that a complex local neuronal circuitry in the OHC area, formed by the dendrites of type-II neurons and modulated by the olivocochlear system, may be a fundamental property of the mammalian cochlea, rather than a curiosity of the primate ear. This network may mediate local feedback control of, and bidirectional communication among, OHCs throughout the cochlear spiral.

A comparison of the shaping ability of three nickel-titanium rotary instruments: a micro-computed tomography study via a contrast radiopaque technique in vitro.

PubMed

Wei, Zhao; Cui, Zhi; Yan, Ping; Jiang, Han

2017-01-09

Micro-CT (μCT) studies that combine simulated canals with meglucamine diatrizoate to evaluate the shaping ability of nickel-titanium (NiTi) rotary instruments are lacking in the literature. The purpose of this study was to evaluate the shaping ability of three new different nickel-titanium rotary instruments in simulated root canals using μCT. Thirty simulated root canals with a curvature of 60° were randomly allocated into the following 3 groups (n = 10): Group 1, ProTaper Universal (PTU) rotary system; Group 2, Reciproc single-file system; and Group 3, K3XF rotary system. Pre- and post-instrumented images of simulated canals were scanned with μCT via a radiopaque contrast technique to build a 3-dimensional (3D) model. Canal transportation, volumetric change and centring ability were evaluated in each group. Instrument failure and preparation time were also recorded. The Kruskal-Wallis test was used for statistical analysis and the significance level was set at p = 0.05. Reciproc produced greater volume change in the apical part of the canals compared with PTU and K3XF (p < 0.05). K3XF exhibited less transportation and better centring ability at the 2- and 3-mm levels from the apical foramen compared with PTU and Reciproc (p < 0.05). There were no significant differences in the centring ratio and transportation between PTU and Reciproc. Preparation time was significantly shorter in the Reciproc group (p < 0.05). Under the conditions of our study, all of the canals were 3D reconstructed successfully via the radiopaque contrast technique. Reciproc showed enhanced apical volume changes and K3XF exhibited better centring ability when compared with other groups.

Kinetics of reciprocating drug delivery to the inner ear.

PubMed

Pararas, Erin E Leary; Chen, Zhiqiang; Fiering, Jason; Mescher, Mark J; Kim, Ernest S; McKenna, Michael J; Kujawa, Sharon G; Borenstein, Jeffrey T; Sewell, William F

2011-06-10

Reciprocating drug delivery is a means of delivering soluble drugs directly to closed fluid spaces in the body via a single cannula without an accompanying fluid volume change. It is ideally suited for drug delivery into small, sensitive and unique fluid spaces such as the cochlea. We characterized the pharmacokinetics of reciprocating drug delivery to the scala tympani within the cochlea by measuring the effects of changes in flow parameters on the distribution of drug throughout the length of the cochlea. Distribution was assessed by monitoring the effects of DNQX, a reversible glutamate receptor blocker, delivered directly to the inner ear of guinea pigs using reciprocating flow profiles. We then modeled the effects of those parameters on distribution using both an iterative curve-fitting approach and a computational fluid dynamic model. Our findings are consistent with the hypothesis that reciprocating delivery distributes the drug into a volume in the base of the cochlea, and suggest that the primary determinant of distribution throughout more distal regions of the cochlea is diffusion. Increases in flow rate distributed the drug into a larger volume that extended more apically. Over short time courses (less than 2h), the apical extension, though small, significantly enhanced apically directed delivery of drug. Over longer time courses (>5h) or greater distances (>3mm), maintenance of drug concentration in the basal scala tympani may prove more advantageous for extending apical delivery than increases in flow rate. These observations demonstrate that this reciprocating technology is capable of providing controlled delivery kinetics to the closed fluid space in the cochlea, and may be suitable for other applications such as localized brain and retinal delivery. Copyright © 2011 Elsevier B.V. All rights reserved.

Kinetics of Reciprocating Drug Delivery to the Inner Ear

PubMed Central

Leary Pararas, Erin E.; Chen, Zhiqiang; Fiering, Jason; Mescher, Mark J.; Kim, Ernest S.; McKenna, Michael J.; Kujawa, Sharon G.; Borenstein, Jeffrey T.; Sewell, William F.

2011-01-01

Reciprocating drug delivery is a means of delivering soluble drugs directly to closed fluid spaces in the body via a single cannula without an accompanying fluid volume change. It is ideally suited for drug delivery into small, sensitive and unique fluid spaces such as the cochlea. We characterized the pharmacokinetics of reciprocating drug delivery to the scala tympani within the cochlea by measuring the effects of changes in flow parameters on the distribution of drug throughout the length of the cochlea. Distribution was assessed by monitoring the effects of DNQX, a reversible glutamate receptor blocker, delivered directly to the inner ear of guinea pigs using reciprocating flow profiles. We then modeled the effects of those parameters on distribution using both an iterative curve-fitting approach and a computational fluid dynamic model. Our findings are consistent with the hypothesis that reciprocating delivery distributes the drug into a volume in the base of the cochlea, and suggest that the primary determinant of distribution throughout more distal regions of the cochlea is diffusion. Increases in flow rate distributed the drug into a larger volume that extended more apically. Over short time courses (less than 2 h), the apical extension, though small, significantly enhanced apically directed delivery of drug. Over longer time courses (>5 h) or greater distances (>3 mm), maintenance of drug concentration in the basal scala tympani may prove more advantageous for extending apical delivery than increases in flow rate. These observations demonstrate that this reciprocating technology is capable of providing controlled delivery kinetics to the closed fluid space in the cochlea, and may be suitable for other applications such as localized brain and retinal delivery. PMID:21385596

Effect of finishing instrumentation using NiTi hand files on volume, surface area and uninstrumented surfaces in C-shaped root canal systems.

PubMed

Amoroso-Silva, P; Alcalde, M P; Hungaro Duarte, M A; De-Deus, G; Ordinola-Zapata, R; Freire, L G; Cavenago, B C; De Moraes, I G

2017-06-01

To assess the effect of 90°-oscillatory instrumentation with hand files on several morphological parameters (volume, surface area and uninstrumented surface) in C-shaped root canals after instrumentation using a single-file reciprocation system (Reciproc; VDW, Munich, Germany) and a Self-Adjusting File System (SAF; ReDent Nova, Ra'anana, Israel). Twenty mandibular second molars with C-shaped canals and C1 canal configurations were divided into two groups (n = 10) and instrumented with Reciproc and SAF instruments. A size 30 NiTi hand K-file attached to a 90°-oscillatory motion handpiece was used as final instrumentation in both groups. The specimens were scanned using micro-computed tomography after all procedures. Volume, surface area increase and uninstrumented root canal surface were analysed using CTAn software (Bruker-microCT, Kontich, Belgium). Also, the uninstrumented root canal surface was calculated for each canal third. All values were compared between groups using the Mann-Whitney test and within groups using the Wilcoxon's signed-rank test. Instrumentation with Reciproc significantly increased canal volume compared with instrumentation with SAF. Additionally, the canal volumes were significantly increased after 90°-oscillatory instrumentation (between and within group comparison; (P < 0.05)). Regarding the increase in surface area after all instrumentation protocols, statistical analysis only revealed significant differences in the within groups comparison (P < 0.05). Reciproc and SAF instrumentation yielded an uninstrumented root canal surface of 28% and 34%, respectively, which was not significantly different (P > 0.05). Final oscillatory instrumentation significantly reduced the uninstrumented root canal surface from 28% to 9% (Reciproc) and from 34% to 15% (SAF; P < 0.05). The apical and middle thirds exhibited larger uninstrumented root canal surfaces after the first instrumentation that was significantly reduced after oscillatory instrumentation (P < 0.05). The Reciproc and SAF system were associated with similar morphological parameters after instrumentation of mandibular second molars with C-shaped canals except for a higher canal volume increase in the Reciproc group compared to the SAF. Furthermore, the final use of 90°-oscillatory instrumentation using NiTi hand files significantly decreased the uninstrumented canal walls that remained after Reciproc and SAF instrumentation. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Advanced Reciprocating Engine Systems (ARES) Research at Argonne National Laboratory. A Report

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

Gupta, Sreenath; Biruduganti, Muni; Bihari, Bipin

The goals of these experiments were to determine the potential of employing spectral measurements to deduce combustion metrics such as HRR, combustion temperatures, and equivalence ratios in a natural gas-fired reciprocating engine. A laser-ignited, natural gas-fired single-cylinder research engine was operated at various equivalence ratios between 0.6 and 1.0, while varying the EGR levels between 0% and maximum to thereby ensure steady combustion. Crank angle-resolved spectral signatures were collected over 266-795 nm, encompassing chemiluminescence emissions from OH*, CH*, and predominantly by CO2* species. Further, laser-induced gas breakdown spectra were recorded under various engine operating conditions.

The temporal structure of intergenerational exchange: a within-family analysis of parent-child reciprocity.

PubMed

Leopold, Thomas; Raab, Marcel

2013-08-01

Previous studies of parent-child reciprocity have focused either on the long term (generalized exchange over the life course) or on the short term (concurrent exchange in later life). The purpose of this research was to investigate the linkage between both temporal patterns of reciprocity within an integrative conceptual framework. We assessed whether long-term and short-term reciprocity operated as interdependent mechanisms that initially selected and subsequently relieved intergenerational caregiving relationships. We used data from the Asset and Health Dynamics Among the Oldest Old study (AHEAD) provided by frail, single-living parents of at least two children (N=1010 respondents comprising 3768 parent-child dyads). Fixed-effects conditional logit models estimated between-sibling differences in assistance provided to parents, measured by instrumental help (i.e., assistance with IADLs) and hands-on care (i.e., assistance with ADLs). Key predictors were two measures of financial transfers given to children referring to longer and shorter recall periods. Receiving earlier and current financial transfers increased adult children's propensity to support their parents in later life. The effect of earlier transfers pertained to help rather than care whereas the reverse was true for the effect of current transfers. We found no evidence for a linkage between long-term and short-term reciprocity. Overall, the results indicate that adult children might balance long-term support accounts relative to their siblings, suggesting an intra-generational orientation on equity. Copyright © 2013 Elsevier Inc. All rights reserved.

Reciprocal Exchange Patterned by Market Forces Helps Explain Cooperation in a Small-Scale Society.

PubMed

Jaeggi, Adrian V; Hooper, Paul L; Beheim, Bret A; Kaplan, Hillard; Gurven, Michael

2016-08-22

Social organisms sometimes depend on help from reciprocating partners to solve adaptive problems [1], and individual cooperation strategies should aim to offer high supply commodities at low cost to the donor in exchange for high-demand commodities with large return benefits [2, 3]. Although such market dynamics have been documented in some animals [4-7], naturalistic studies of human cooperation are often limited by focusing on single commodities [8]. We analyzed cooperation in five domains (meat sharing, produce sharing, field labor, childcare, and sick care) among 2,161 household dyads of Tsimane' horticulturalists, using Bayesian multilevel models and information-theoretic model comparison. Across domains, the best-fit models included kinship and residential proximity, exchanges in kind and across domains, measures of supply and demand and their interactions with exchange, and household-specific exchange slopes. In these best models, giving, receiving, and reciprocating were to some extent shaped by market forces, and reciprocal exchange across domains had a strong partial effect on cooperation independent of more exogenous factors like kinship and proximity. Our results support the view that reciprocal exchange can provide a reliable solution to adaptive problems [8-11]. Although individual strategies patterned by market forces may generate gains from trade in any species [3], humans' slow life history and skill-intensive foraging niche favor specialization and create interdependence [12, 13], thus stabilizing cooperation and fostering divisions of labor even in informal economies [14, 15]. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative evaluation of apically extruded debris during root canal preparation using ProTaper™, Hyflex™ and Waveone™ rotary systems

PubMed Central

Surakanti, Jayaprada Reddy; Venkata, Ravi Chandra Polavarapu; Vemisetty, Hari Kumar; Dandolu, Ram Kiran; Jaya, Nagendra Krishna Muppalla; Thota, Shirisha

2014-01-01

Background and Aims: Extrusion of any debris during endodontic treatment may potentially cause post-operative complications such as flare-ups. The purpose of this in vitro study was to assess the amount of apically extruded debris during the root canal preparation using rotary and reciprocating nickel-titanium instrumentation systems. Materials and Methods: In this study, 60 human mandibular first premolars were randomly assigned to 3 groups (n = 20 teeth/group). The root canals were instrumented according to the manufacturers’ instructions using the Reciprocating single-file system WaveOne™ (Dentsply Maillefer, Ballaigues, Switzerland) and full-sequence rotary Hyflex CM™ (Coltene Whaledent, Allstetten, Switzerland) and ProTaper™ (Dentsply Maillefer, Ballaigues, Switzerland) instruments. The canals were then irrigated using bidistilled water. The debris that was extruded apically was collected in preweighed eppendorf tubes and assessed with an electronic balance and compared. Statistical Analysis Used: The debris extrusion was compared and statistically analyzed using analysis of variance and the post hoc Student-Newman-Keuls test. Results: The WaveOne™ and ProTaper™ rotary instruments produced significantly more debris compared with Hyflex CM™ rotary instruments (P < 0.05). Conclusions: Under the conditions of this study, all systems that were used resulted in extrusion of apical debris. Full-sequence rotary instrumentation was associated with less debris extrusion compared with the use of reciprocating single-file systems. PMID:24778507

Exponential approximations in optimal design

NASA Technical Reports Server (NTRS)

Belegundu, A. D.; Rajan, S. D.; Rajgopal, J.

1990-01-01

One-point and two-point exponential functions have been developed and proved to be very effective approximations of structural response. The exponential has been compared to the linear, reciprocal and quadratic fit methods. Four test problems in structural analysis have been selected. The use of such approximations is attractive in structural optimization to reduce the numbers of exact analyses which involve computationally expensive finite element analysis.

Semi-active compressor valve

DOEpatents

Brun, Klaus; Gernentz, Ryan S.

2010-07-27

A method and system for fine-tuning the motion of suction or discharge valves associated with cylinders of a reciprocating gas compressor, such as the large compressors used for natural gas transmission. The valve's primary driving force is conventional, but the valve also uses an electromagnetic coil to sense position of the plate (or other plugging element) and to provide an opposing force prior to impact.

3 CFR 13488 - Executive Order 13488 of January 16, 2009. Granting Reciprocity on Excepted Service and Federal...

Code of Federal Regulations, 2010 CFR

2010-01-01

..., United States Code, but does not include those positions in any element of the intelligence community as... 3 The President 1 2010-01-01 2010-01-01 false Executive Order 13488 of January 16, 2009. Granting... and Reinvestigating Individuals in Positions of Public Trust By the authority vested in me as...

Tolerant indirect reciprocity can boost social welfare through solidarity with unconditional cooperators in private monitoring.

PubMed

Okada, Isamu; Sasaki, Tatsuya; Nakai, Yutaka

2017-08-29

Indirect reciprocity is an important mechanism for resolving social dilemmas. Previous studies explore several types of assessment rules that are evolutionarily stable for keeping cooperation regimes. However, little is known about the effects of private information on social systems. Most indirect reciprocity studies assume public monitoring in which individuals share a single assessment for each individual. Here, we consider a private monitoring system that loosens such an unnatural assumption. We explore the stable norms in the private system using an individual-based simulation. We have three main findings. First, narrow and unstable cooperation: cooperation in private monitoring becomes unstable and the restricted norms cannot maintain cooperative regimes while they can in public monitoring. Second, stable coexistence of discriminators and unconditional cooperators: under private monitoring, unconditional cooperation can play a role in keeping a high level of cooperation in tolerant norm situations. Finally, Pareto improvement: private monitoring can achieve a higher cooperation rate than does public monitoring.

Adhesive and tribocorrosive behavior of TiAlPtN/TiAlN/TiAl multilayers sputtered coatings over CoCrMo

NASA Astrophysics Data System (ADS)

Canto, C. E.; Andrade, E.; Rocha, M. F.; Alemón, B.; Flores, M.

2017-09-01

The tribocorrosion resistance and adherence of multilayer coatings of TiAlPtN/TiAlN/TiAl synthesized by PVD reactive magnetron sputtering over a CoCrMo alloy substrate in 10 periods of 30 min each were analyzed and compared to those of the substrate alone and to that of a TiAlPtN single layer coating of the same thickness. The objective of the present work was to create multilayers with different amounts of Pt in order to enhance the tribocorrosion resistance of a biomedical alloy of CoCrMo. Tribocorrosion tests were performed using Simulated Body Fluid (SBF) at typical body temperature with a tribometer in a pin on disk test. The elemental composition and thickness of the coating which behave better at the tribocorrosion tests were evaluated by means of RBS (Rutherford Backscattering Spectroscopy) IBA (Ion Beam Analysis) technique, using an alpha particles beam of 1.8 MeV, before and after the reciprocating motion in the tribocorrosion test. In order to simulate the elemental profile of the samples, the SIMNRA simulation computer code was used. Measurements of the adhesion of the coatings to the substrate were carried on by means of a scratch test using a tribometer. By taking micrographs of the produced tracks, the critical loads at which the coatings are fully separated from the substrate were determined. From these tests it was observed that a coating with 10 min of TiAlPtN in a TiAlPtN/TiAl period of 30 min in multilayers of 10 periods and with an average thickness of 145 nm for the TiAlPtN nanolayers had the best tribocorrosion resistance behavior, compared to that of the CoCrMo alloy. The RBS experiments showed a reduction of the thickness of the films along with some loss of the multilayer structure after the reciprocating motion. The adhesion tests indicated that the multilayer with the average TiAlPtN thickness of 145 nm displayed the highest critical load. These results indicate a high correlation between the adherence and the tribocorrosion behavior.

The Effect of Canal Preparation with Four Different Rotary Systems on Formation of Dentinal Cracks: An In Vitro Evaluation.

PubMed

Khoshbin, Elham; Donyavi, Zakiyeh; Abbasi Atibeh, Erfan; Roshanaei, Ghodratollah; Amani, Faranak

2018-01-01

Endodontic rotary systems may result in dentinal cracks. They may propagate to vertical root fracture that compromises the outcome of endodontic treatment. This study aimed to compare Neolix and Reciproc (single-file systems), Mtwo and ProTaper (conventional rotary systems) in terms of dentinal crack formation in root canal walls. This in vitro study was conducted on 110 extracted human single-rooted teeth. The teeth were randomly divided into four experimental groups ( n =25) for root canal preparation with Neolix, Reciproc, Mtwo and ProTaper systems and two control groups ( n =5). The first control group underwent root canal instrumentation with hand files while the second control group received no preparation and was only irrigated. After instrumentation, root canals were horizontally sectioned at 3, 6 and 9 mm from the apex and inspected under a stereomicroscope under 12× magnification for detection of cracks. The data were analyzed using Chi-square, GEE test and Bonferroni tests ( P <0.05). No crack was found in the control groups. All rotary systems caused dentinal cracks. ProTaper, Reciproc, Mtwo and Neolix caused cracks in 92%, 80%, 68% and 48% of samples. ProTaper caused significantly more cracks than Neolix and Mtwo ( P <0.05). No significant differences were noted between other groups ( P >0.05). All rotary systems cause dentinal cracks and it is significantly different in apical, middle and coronal third of the root. Neolix appears to be a suitable alternative to other rotary systems since use of this single-file system saves time and cost and minimizes trauma to dentinal walls.

The Effect of Canal Preparation with Four Different Rotary Systems on Formation of Dentinal Cracks: An In Vitro Evaluation

PubMed Central

Khoshbin, Elham; Donyavi, Zakiyeh; Abbasi Atibeh, Erfan; Roshanaei, Ghodratollah; Amani, Faranak

2018-01-01

Introduction: Endodontic rotary systems may result in dentinal cracks. They may propagate to vertical root fracture that compromises the outcome of endodontic treatment. This study aimed to compare Neolix and Reciproc (single-file systems), Mtwo and ProTaper (conventional rotary systems) in terms of dentinal crack formation in root canal walls. Methods and Materials: This in vitro study was conducted on 110 extracted human single-rooted teeth. The teeth were randomly divided into four experimental groups (n=25) for root canal preparation with Neolix, Reciproc, Mtwo and ProTaper systems and two control groups (n=5). The first control group underwent root canal instrumentation with hand files while the second control group received no preparation and was only irrigated. After instrumentation, root canals were horizontally sectioned at 3, 6 and 9 mm from the apex and inspected under a stereomicroscope under 12× magnification for detection of cracks. The data were analyzed using Chi-square, GEE test and Bonferroni tests (P<0.05). Results: No crack was found in the control groups. All rotary systems caused dentinal cracks. ProTaper, Reciproc, Mtwo and Neolix caused cracks in 92%, 80%, 68% and 48% of samples. ProTaper caused significantly more cracks than Neolix and Mtwo (P<0.05). No significant differences were noted between other groups (P>0.05). Conclusion: All rotary systems cause dentinal cracks and it is significantly different in apical, middle and coronal third of the root. Neolix appears to be a suitable alternative to other rotary systems since use of this single-file system saves time and cost and minimizes trauma to dentinal walls. PMID:29707009

Use of the reciprocity theorem for a closed form solution of scattering of the lowest axially symmetric torsional wave mode by a defect in a pipe.

PubMed

Lee, Jaesun; Achenbach, Jan D; Cho, Younho

2018-03-01

Guided waves can effectively be used for inspection of large scale structures. Surface corrosion is often found as major defect type in large scale structures such as pipelines. Guided wave interaction with surface corrosion can provide useful information for sizing and classification. In this paper, the elastodynamic reciprocity theorem is used to formulate and solve complicated scattering problems in a simple manner. The approach has already been applied to scattering of Rayleigh and Lamb waves by defects to produce closed form solutions of amplitude of scattered waves. In this paper, the scattering of the lowest axially symmetric torsional mode, which is widely used in commercial applications, is analyzed by the reciprocity theorem. In the present paper, the theorem is used to determine the scattering of the lowest torsional mode by a tapered defect that was earlier considered experimentally and numerically by the finite element method. It is shown that by the presented method it is simple to obtain the ratio of amplitudes of scattered torsional modes for a tapered notch. The results show a good agreement with earlier numerical results. The wave field superposition technique in conjunction with the reciprocity theorem simplifies the solution of the scattering problem to yield a closed form solution which can play a significant role in quantitative signal interpretation. Copyright © 2017 Elsevier B.V. All rights reserved.

Cooperation beyond the dyad: on simple models and a complex society

PubMed Central

Connor, Richard C.

2010-01-01

Players in Axelrod and Hamilton's model of cooperation were not only in a Prisoner's Dilemma, but by definition, they were also trapped in a dyad. But animals are rarely so restricted and even the option to interact with third parties allows individuals to escape from the Prisoner's Dilemma into a much more interesting and varied world of cooperation, from the apparently rare ‘parcelling’ to the widespread phenomenon of market effects. Our understanding of by-product mutualism, pseudo-reciprocity and the snowdrift game is also enriched by thinking ‘beyond the dyad’. The concepts of by-product mutualism and pseudo-reciprocity force us to think again about our basic definitions of cooperative behaviour (behaviour by a single individual) and cooperation (the outcome of an interaction between two or more individuals). Reciprocity is surprisingly rare outside of humans, even among large-brained ‘intelligent’ birds and mammals. Are humans unique in having extensive cooperative interactions among non-kin and an integrated cognitive system for mediating reciprocity? Perhaps, but our best chance for finding a similar phenomenon may be in delphinids, which also live in large societies with extensive cooperative interactions among non-relatives. A system of nested male alliances in bottlenose dolphins illustrates the potential and difficulties of finding a complex system of cooperation close to our own. PMID:20679112

Interactions of Circadian Rhythmicity, Stress and Orexigenic Neuropeptide Systems: Implications for Food Intake Control.

PubMed

Blasiak, Anna; Gundlach, Andrew L; Hess, Grzegorz; Lewandowski, Marian H

2017-01-01

Many physiological processes fluctuate throughout the day/night and daily fluctuations are observed in brain and peripheral levels of several hormones, neuropeptides and transmitters. In turn, mediators under the "control" of the "master biological clock" reciprocally influence its function. Dysregulation in the rhythmicity of hormone release as well as hormone receptor sensitivity and availability in different tissues, is a common risk-factor for multiple clinical conditions, including psychiatric and metabolic disorders. At the same time circadian rhythms remain in a strong, reciprocal interaction with the hypothalamic-pituitary-adrenal (HPA) axis. Recent findings point to a role of circadian disturbances and excessive stress in the development of obesity and related food consumption and metabolism abnormalities, which constitute a major health problem worldwide. Appetite, food intake and energy balance are under the influence of several brain neuropeptides, including the orexigenic agouti-related peptide, neuropeptide Y, orexin, melanin-concentrating hormone and relaxin-3. Importantly, orexigenic neuropeptide neurons remain under the control of the circadian timing system and are highly sensitive to various stressors, therefore the potential neuronal mechanisms through which disturbances in the daily rhythmicity and stress-related mediator levels contribute to food intake abnormalities rely on reciprocal interactions between these elements.

Housework: Cause and consequence of gender ideology?

PubMed

Carlson, Daniel L; Lynch, Jamie L

2013-11-01

Nearly all quantitative studies examining the association between the division of housework and gender ideology have found that gender egalitarianism results in less housework for wives, more for husbands, and more equal sharing of housework by couples. However, a few studies suggest housework has a nontrivial influence on gender ideology. An overreliance on single-direction, single-equation regression models and cross-sectional data has limited past research from making strong claims about the causal relationship between gender ideology and housework. We use data on married couples from Waves 1 and 2 of the National Survey of Families and Households and nonrecursive simultaneous equation models to assess the causal relationship between housework and gender ideology. Results show a mutual and reciprocal relationship between the division of housework and gender ideology for both husbands' and wives'. Reciprocity is strongest for husbands while for wives the relationship is partially indirect and mediated through their husbands' gender ideologies. Copyright © 2013 Elsevier Inc. All rights reserved.

Asymmetric nonlinear system is not sufficient for a nonreciprocal wave diode

NASA Astrophysics Data System (ADS)

Wu, Gaomin; Long, Yang; Ren, Jie

2018-05-01

We demonstrate symmetric wave propagations in asymmetric nonlinear systems. By solving the nonlinear Schördinger equation, we first analytically prove the existence of symmetric transmission in asymmetric systems with a single nonlinear delta-function interface. We then point out that a finite width of the nonlinear interface region is necessary to produce nonreciprocity in asymmetric systems. However, a geometrical resonant condition for breaking nonreciprocal propagation is then identified theoretically and verified numerically. With such a resonant condition, the nonlinear interface region of finite width behaves like a single nonlinear delta-barrier so that wave propagations in the forward and backward directions are identical under arbitrary incident wave intensity. As such, reciprocity reemerges periodically in the asymmetric nonlinear system when changing the width of interface region. Finally, similar resonant conditions of discrete nonlinear Schördinger equation are discussed. Therefore, we have identified instances of reciprocity that breaking spatial symmetry in nonlinear interface systems is not sufficient to produce nonreciprocal wave propagation.

Elements of the corruption crime (element analysis of authority abuse and self-enrich and corporations in Indonesia)

NASA Astrophysics Data System (ADS)

Mandasari Saragih, Yasmirah; Medaline, Onny

2018-03-01

In effect the authority abuse very closely relates to the presence of invalidity (disability juridical) of a decision or government action/state officials. Sadjijono, by citing the opinion of M. Hadjon Phlipus suggests that defective judicial decision or government action/state officials generally involves three main elements, namely the element of authority, the element of the procedure and elements of substance, thus flawed judicial action state officials can be classified into three kinds, namely: disability authority, defective procedure and substance defects. The three of them are the essence of the onset authority abuse. Their acts that profitable and or self-enrich or another person or entity covering for the authority abuse or opportunity. These criteria have been expanded because there is a term for position and so on, including bribery, both among non-civil and public servants. Reciprocally with the given gifts and the promise of the new legislation, the criteria have been expanded.

Learning through Teaching: Challenges and Opportunities in Facilitating Student Learning in Food Science and Nutrition by Using the Interteaching Approach

ERIC Educational Resources Information Center

Goto, Keiko; Schneider, Julie

2010-01-01

Interteaching is a new pedagogical strategy for classroom instruction that demonstrates great effective student learning outcomes in the field of psychology. It is a 20 to 30 min student-to-student discussion addressing the main points in a specified body of reading materials. Interteaching includes elements such as reciprocal peer tutoring,…

Soviet Policy Issues

DTIC Science & Technology

1989-05-01

ADORESS (City, .,n Zip Co4k) 10. SOURCE OF FUNDING NUMBERS PROGRAM ELEMENT PROJECT NO.1 TASK NO. ACCESSION NO. WORK UNIT 11. TITLE (Includ. Securily ...gaining military advantage, had insisted on reciprocal (albeit asymmetrical if necessary) force reductions. But Gorbachev, perceiving the growing need...fortifications backed up by mobile counter-attack forces--appears identical in the forward region. The existence of rapidly mobilizable second-echelon forces in

Shaping ability of reciprocating single-file systems in severely curved canals: WaveOne and Reciproc versus WaveOne Gold and Reciproc blue.

PubMed

Bürklein, Sebastian; Flüch, Stefanie; Schäfer, Edgar

2018-05-18

The aim was to compare the canal straightening of M-wire [Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply Maillefer, Ballaigues, Switzerland)] and gold- and blue-wire heat-treated [Reciproc blue (VDW) and WaveOne Gold (Dentsply Maillefer)] instruments in severely curved root canals. A total of 80 root canals in extracted human teeth with angles of curvatures ranging between 25° and 35° and radii ranging between 3.1 and 8.5 mm were divided into four groups (n = 20). Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radius of canal curvature (P = 1.0 and P = 1.0, respectively). All canals were prepared to an apical size 25 according to the manufacturers' instructions. Pre- and post-instrumentation radiographs were superimposed and canal straightening was analysed using a computer imaging programme. Preparation time and instrument failure were also recorded. Data were analysed statistically using ANOVA and Student-Newman-Keuls test. During preparation no instrument fractured. All instruments maintained the original canal curvature well with no significant differences between the instruments (P = 0.278). Regarding preparation time, no significant differences between the four instruments were obtained (P > 0.05). Under the conditions of this study, all instruments respected the original canal curvature well. Instruments were safe to use. The use of the gold- and blue-wire heat-treated instruments was not associated with an improved shaping ability.

Preovulatory estradiol and the establishment and maintenance of pregnancy in suckled beef cows

USDA-ARS?s Scientific Manuscript database

In postpartum beef cows, GnRH-induced ovulation of small dominant follicles decreased pregnancy rates and increased late embryonic/fetal mortality. In Exp. 1, single ovulation reciprocal embryo transfer (ET) was utilized to examine the relationship between preovulatory serum concentrations of estrad...

14 CFR 23.49 - Stalling period.

Code of Federal Regulations, 2010 CFR

2010-01-01

... which the airplane is controllable with— (1) For reciprocating engine-powered airplanes, the engine(s... more than 110 percent of the stalling speed; (2) For turbine engine-powered airplanes, the propulsive..., VSOand VS1at maximum weight must not exceed 61 knots for— (1) Single-engine airplanes; and (2...

Multiple Scattering in Planetary Regoliths Using Incoherent Interactions

NASA Astrophysics Data System (ADS)

Muinonen, K.; Markkanen, J.; Vaisanen, T.; Penttilä, A.

2017-12-01

We consider scattering of light by a planetary regolith using novel numerical methods for discrete random media of particles. Understanding the scattering process is of key importance for spectroscopic, photometric, and polarimetric modeling of airless planetary objects, including radar studies. In our modeling, the size of the spherical random medium can range from microscopic to macroscopic sizes, whereas the particles are assumed to be of the order of the wavelength in size. We extend the radiative transfer and coherent backscattering method (RT-CB) to the case of dense packing of particles by adopting the ensemble-averaged first-order incoherent extinction, scattering, and absorption characteristics of a volume element of particles as input. In the radiative transfer part, at each absorption and scattering process, we account for absorption with the help of the single-scattering albedo and peel off the Stokes parameters of radiation emerging from the medium in predefined scattering angles. We then generate a new scattering direction using the joint probability density for the local polar and azimuthal scattering angles. In the coherent backscattering part, we utilize amplitude scattering matrices along the radiative-transfer path and the reciprocal path. Furthermore, we replace the far-field interactions of the RT-CB method with rigorous interactions facilitated by the Superposition T-matrix method (STMM). This gives rise to a new RT-RT method, radiative transfer with reciprocal interactions. For microscopic random media, we then compare the new results to asymptotically exact results computed using the STMM, succeeding in the numerical validation of the new methods.Acknowledgments. Research supported by European Research Council with Advanced Grant No. 320773 SAEMPL, Scattering and Absorption of ElectroMagnetic waves in ParticuLate media. Computational resources provided by CSC - IT Centre for Science Ltd, Finland.

Mechanisms of Zero-Lag Synchronization in Cortical Motifs

PubMed Central

Gollo, Leonardo L.; Mirasso, Claudio; Sporns, Olaf; Breakspear, Michael

2014-01-01

Zero-lag synchronization between distant cortical areas has been observed in a diversity of experimental data sets and between many different regions of the brain. Several computational mechanisms have been proposed to account for such isochronous synchronization in the presence of long conduction delays: Of these, the phenomenon of “dynamical relaying” – a mechanism that relies on a specific network motif – has proven to be the most robust with respect to parameter mismatch and system noise. Surprisingly, despite a contrary belief in the community, the common driving motif is an unreliable means of establishing zero-lag synchrony. Although dynamical relaying has been validated in empirical and computational studies, the deeper dynamical mechanisms and comparison to dynamics on other motifs is lacking. By systematically comparing synchronization on a variety of small motifs, we establish that the presence of a single reciprocally connected pair – a “resonance pair” – plays a crucial role in disambiguating those motifs that foster zero-lag synchrony in the presence of conduction delays (such as dynamical relaying) from those that do not (such as the common driving triad). Remarkably, minor structural changes to the common driving motif that incorporate a reciprocal pair recover robust zero-lag synchrony. The findings are observed in computational models of spiking neurons, populations of spiking neurons and neural mass models, and arise whether the oscillatory systems are periodic, chaotic, noise-free or driven by stochastic inputs. The influence of the resonance pair is also robust to parameter mismatch and asymmetrical time delays amongst the elements of the motif. We call this manner of facilitating zero-lag synchrony resonance-induced synchronization, outline the conditions for its occurrence, and propose that it may be a general mechanism to promote zero-lag synchrony in the brain. PMID:24763382

[A study of linearity and reciprocity during shock applied with a hammer to human dry skull].

PubMed

Kumazawa, Y; Sekiguchi, J; Saito, M; Honma, K; Toyoda, M; Matsuo, E

1990-09-01

The authors used a human dry skull on which the cranial bone mandible had been joined with an artificial articulator disk to form a single unit. Impact acceleration corresponding to weak and strong tapping was considered a dynamic load in examining the vibration transfer characteristics of the facial cranial bone when impact was applied from the mentum section in a situation designed to be closer to reality. Flexion injection type (resonance frequency f0 = 100 to 150 Hz, produced by GC Corp.) was applied to the human dry skull as an artificial periodontal membrane at thickness of 0.3 mm. In addition, Exaflex heavy body type (f0 = 400 Hz, produced by GC Corp.) was applied as an artificial disk. This was then placed on a damper produced by spreading a rubber dam sheet with a thickness of 35 microns on a tire tube with a diameter of 35 cm and an air pressure of 35 kg/cm2. Investigations were then made concerning linearity and reciprocity to determine whether an experimental system could be achieved or not. This was then followed by modal analysis. As a result, the following matters were ascertained: (1) The resonating area differed according to the extent of the force. (2) An increase in the viscoelastic elements of the silicon was accompanied by attenuation of force. (3) Directionality of force attenuation was caused by the complexity of bone structure. (4) A tapping force of 0.3G or 1G was sufficiently attenuated by the facial cranial bone. (5) The transfer function at the bone seams and thinner areas of the bones was insufficient for modal analysis of the facial region and total cranial bone of the human dry skull.

In situ MEMS testing: correlation of high-resolution X-ray diffraction with mechanical experiments and finite element analysis.

PubMed

Schifferle, Andreas; Dommann, Alex; Neels, Antonia

2017-01-01

New methods are needed in microsystems technology for evaluating microelectromechanical systems (MEMS) because of their reduced size. The assessment and characterization of mechanical and structural relations of MEMS are essential to assure the long-term functioning of devices, and have a significant impact on design and fabrication. Within this study a concept for the investigation of mechanically loaded MEMS materials on an atomic level is introduced, combining high-resolution X-ray diffraction (HRXRD) measurements with finite element analysis (FEA) and mechanical testing. In situ HRXRD measurements were performed on tensile loaded single crystal silicon (SCSi) specimens by means of profile scans and reciprocal space mapping (RSM) on symmetrical (004) and (440) reflections. A comprehensive evaluation of the rather complex XRD patterns and features was enabled by the correlation of measured with simulated, 'theoretical' patterns. Latter were calculated by a specifically developed, simple and fast approach on the basis of continuum mechanical relations. Qualitative and quantitative analysis confirmed the admissibility and accuracy of the presented method. In this context [001] Poisson's ratio was determined providing an error of less than 1.5% with respect to analytical prediction. Consequently, the introduced procedure contributes to further going investigations of weak scattering being related to strain and defects in crystalline structures and therefore supports investigations on materials and devices failure mechanisms.

In situ MEMS testing: correlation of high-resolution X-ray diffraction with mechanical experiments and finite element analysis

PubMed Central

Schifferle, Andreas; Dommann, Alex; Neels, Antonia

2017-01-01

Abstract New methods are needed in microsystems technology for evaluating microelectromechanical systems (MEMS) because of their reduced size. The assessment and characterization of mechanical and structural relations of MEMS are essential to assure the long-term functioning of devices, and have a significant impact on design and fabrication. Within this study a concept for the investigation of mechanically loaded MEMS materials on an atomic level is introduced, combining high-resolution X-ray diffraction (HRXRD) measurements with finite element analysis (FEA) and mechanical testing. In situ HRXRD measurements were performed on tensile loaded single crystal silicon (SCSi) specimens by means of profile scans and reciprocal space mapping (RSM) on symmetrical (004) and (440) reflections. A comprehensive evaluation of the rather complex XRD patterns and features was enabled by the correlation of measured with simulated, ‘theoretical’ patterns. Latter were calculated by a specifically developed, simple and fast approach on the basis of continuum mechanical relations. Qualitative and quantitative analysis confirmed the admissibility and accuracy of the presented method. In this context [001] Poisson’s ratio was determined providing an error of less than 1.5% with respect to analytical prediction. Consequently, the introduced procedure contributes to further going investigations of weak scattering being related to strain and defects in crystalline structures and therefore supports investigations on materials and devices failure mechanisms. PMID:28533825

Flirtation Rejection Strategies: Toward an Understanding of Communicative Disinterest in Flirting

ERIC Educational Resources Information Center

Goodboy, Alan K.; Brann, Maria

2010-01-01

Single adults often seek successful flirtatious encounters; yet these encounters can sometimes be considered failures. However, little research has identified flirtation rejection strategies enacted by those not interested in reciprocal flirting. The purpose of this study was to examine behavioral and verbal flirtation rejection strategies among…

Serial Transmission of Plant Viruses by Cutting During Grafting

USDA-ARS?s Scientific Manuscript database

Reciprocal grafts of two tomato (Solanum lycopersicum L.) cultivars were made by hand using commercial grafting techniques. The razor blade used to cut rootstock or scion was first contaminated by making a single cut on tomato plants infected with either tomato spotted wilt virus (TSWV) or tomato m...

Reciprocal and Complementary Sibling Interactions: Relations with Socialization Outcomes in the Kindergarten Classroom

ERIC Educational Resources Information Center

Harrist, Amanda W.; Achacoso, Joseph A.; John, Aesha; Pettit, Gregory S.; Bates, John E.; Dodge, Kenneth A.

2014-01-01

Research Findings: In this examination of associations between sibling interaction patterns and later social outcomes in single- and 2-parent families, 113 kindergarteners took part in naturalistic observations at home with siblings, classmates participated in sociometric interviews, and teachers completed behavior ratings. Sibling interactions…

Array automated assembly, phase 2

NASA Technical Reports Server (NTRS)

Taylor, W. E.

1978-01-01

An analysis was made of cost tradeoffs for shaping modified square wafers from cylindrical crystals. Tests were conducted of the effectiveness of texture etching for removal of surface damage on sawed wafers. A single step texturing etch appeared adequate for removal of surface damage on wafers cut with multiple blade reciprocating slurry saws.

The Musical Lives of Babies and Families.

ERIC Educational Resources Information Center

Fenichel, Emily, Ed.

2002-01-01

"Zero to Three" is a single focus bulletin of the National Center for Infants, Toddlers, and Families providing insight from multiple disciplines on the development of infants, toddlers, and their families. Noting that knowledge of childrens musical experiences in context is central to understanding childrens lives, and that reciprocally,…

14 CFR 23.77 - Balked landing.

Code of Federal Regulations, 2013 CFR

2013-01-01

... reciprocating engine-powered and single engine turbine powered airplane of more than 6,000 pounds maximum weight, and multiengine turbine engine-powered airplane of 6,000 pounds or less maximum weight in the normal... of movement of the power controls from minimum flight-idle position; (2) The landing gear extended...

14 CFR 23.77 - Balked landing.

Code of Federal Regulations, 2014 CFR

2014-01-01

... reciprocating engine-powered and single engine turbine powered airplane of more than 6,000 pounds maximum weight, and multiengine turbine engine-powered airplane of 6,000 pounds or less maximum weight in the normal... of movement of the power controls from minimum flight-idle position; (2) The landing gear extended...

Leading and Growing in a Culture of Reciprocal Trust

ERIC Educational Resources Information Center

Sopko, Kim Moherek; LaRocco, Diana J.

2018-01-01

Building and sustaining an organizational culture and climate where productive and positive leader-follower relationships can thrive is perhaps the single most important responsibility of those who aspire to lead. The attributes of benevolence, honesty, openness, reliability, and competence form a framework that individuals use in determining a…

Unequal crossing-over associated with asymmetrical synapsis between nomadic elements in the Drosophila melanogaster genome

PubMed Central

Goldberg, Michael L.; Sheen, Jenq-Yunn; Gehring, Walter J.; Green, M. M.

1983-01-01

The molecular structure of reciprocal duplications and deficiencies produced by unequal crossing-over at the white (w) locus of Drosophila melanogaster females heterozygous for the alleles wa and wa4 has been examined. A transposable, copia-like element is found at the rearrangement breakpoints. Further characterization indicates that asymmetrical pairing between two copies of this element, which are at least 60 kilobases apart in the parental chromosomes, followed by a crossover within the paired elements, is responsible for the duplication and deficiencies observed. The frequency of these events is high compared with normal homologous exchange, implying that synaptic pairing during meiosis must be sufficiently flexible as to allow efficient recognition of sequences located in nonidentical positions on homologous chromosomes. These results suggest a possible mechanism for the generation of tandem duplications in eukaryotic organisms. Images PMID:16593354

Assessment of apically extruded debris produced by the single-file ProTaper F2 technique under reciprocating movement.

PubMed

De-Deus, Gustavo; Brandão, Maria Claudia; Barino, Bianca; Di Giorgi, Karina; Fidel, Rivail Antonio Sergio; Luna, Aderval Severino

2010-09-01

This study was designed to quantitatively evaluate the amount of dentin debris extruded from the apical foramen by comparing the conventional sequence of the ProTaper Universal nickel-titanium (NiTi) files with the single-file ProTaper F2 technique. Thirty mesial roots of lower molars were selected, and the use of different instrumentation techniques resulted in 3 groups (n=10 each). In G1, a crown-down hand-file technique was used, and in G2 conventional ProTaper Universal technique was used. In G3, ProTaper F2 file was used in a reciprocating motion. The apical finish preparation was equivalent to ISO size 25. An apparatus was used to evaluate the apically extruded debris. Statistical analysis was performed using 1-way analysis of variance and Tukey multiple comparisons. No significant difference was found in the amount of the debris extruded between the conventional sequence of the ProTaper Universal NiTi files and the single-file ProTaper F2 technique (P>.05). In contrast, the hand instrumentation group extruded significantly more debris than both NiTi groups (P<.05). The present results yielded favorable input for the F2 single-file technique in terms of apically extruded debris, inasmuch as it is the most simple and cost-effective instrumentation approach. Copyright (c) 2010 Mosby, Inc. All rights reserved.

Protein secondary structure prediction using modular reciprocal bidirectional recurrent neural networks.

PubMed

Babaei, Sepideh; Geranmayeh, Amir; Seyyedsalehi, Seyyed Ali

2010-12-01

The supervised learning of recurrent neural networks well-suited for prediction of protein secondary structures from the underlying amino acids sequence is studied. Modular reciprocal recurrent neural networks (MRR-NN) are proposed to model the strong correlations between adjacent secondary structure elements. Besides, a multilayer bidirectional recurrent neural network (MBR-NN) is introduced to capture the long-range intramolecular interactions between amino acids in formation of the secondary structure. The final modular prediction system is devised based on the interactive integration of the MRR-NN and the MBR-NN structures to arbitrarily engage the neighboring effects of the secondary structure types concurrent with memorizing the sequential dependencies of amino acids along the protein chain. The advanced combined network augments the percentage accuracy (Q₃) to 79.36% and boosts the segment overlap (SOV) up to 70.09% when tested on the PSIPRED dataset in three-fold cross-validation. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

[Towards understanding human ecology in nursing practice: a concept analysis].

PubMed

Huynh, Truc; Alderson, Marie

2010-06-01

Human ecology is an umbrella concept encompassing several social, physical, and cultural elements existing in the individual's external environment. The pragmatic utility method was used to analyze the "human ecology" concept in order to ascertain the conceptual fit with nursing epistemology and to promote its use by nurses in clinical practice. Relevant articles for the review were retrieved from the MEDLINE, CINAHL, PsycINFO, and CSA databases using the terms "human ecology," "environment," "nursing," and "ecology." Data analysis revealed that human ecology is perceived as a theoretical perspective designating a complex, multilayered, and multidimensional system, one that comprises individuals and their reciprocal interactions with their global environments and the subsequent impact of these interactions upon their health. Human ecology preconditions include the individuals, their environments, and their transactions. Attributes of this concept encompass the characteristics of an open system (e.g., interdependence, reciprocal).

American Exceptionalism: Essential Context for National Security Strategy Development

DTIC Science & Technology

2006-03-10

character emerge: a belief in the ethical importance of American elements of national power as means and ends in themselves; a belief in the universal...applicability of liberal values and institutions to mankind; a belief in the ethic of reciprocity as a normative means to achieve positive interactions among...nations ; and a belief in the value of maintaining strategic flexibility in an increasingly complex strategic environment. These ethical and value

Object-oriented design and implementation of CFDLab: a computer-assisted learning tool for fluid dynamics using dual reciprocity boundary element methodology

NASA Astrophysics Data System (ADS)

Friedrich, J.

1999-08-01

As lecturers, our main concern and goal is to develop more attractive and efficient ways of communicating up-to-date scientific knowledge to our students and facilitate an in-depth understanding of physical phenomena. Computer-based instruction is very promising to help both teachers and learners in their difficult task, which involves complex cognitive psychological processes. This complexity is reflected in high demands on the design and implementation methods used to create computer-assisted learning (CAL) programs. Due to their concepts, flexibility, maintainability and extended library resources, object-oriented modeling techniques are very suitable to produce this type of pedagogical tool. Computational fluid dynamics (CFD) enjoys not only a growing importance in today's research, but is also very powerful for teaching and learning fluid dynamics. For this purpose, an educational PC program for university level called 'CFDLab 1.1' for Windows™ was developed with an interactive graphical user interface (GUI) for multitasking and point-and-click operations. It uses the dual reciprocity boundary element method as a versatile numerical scheme, allowing to handle a variety of relevant governing equations in two dimensions on personal computers due to its simple pre- and postprocessing including 2D Laplace, Poisson, diffusion, transient convection-diffusion.

Touch, the essence of caring for people with end-stage dementia: a mental health perspective in Namaste Care.

PubMed

Nicholls, Daniel; Chang, Esther; Johnson, Amanda; Edenborough, Michel

2013-01-01

This article presents the mental health aspects of 'touch' associated with a funded research project: Avoiding 'high tech' through 'high touch' in end-stage dementia: Protocol for care at the end-of-life. These mental health aspects highlight the human need for touch that continues up until and inclusive of the final stages of life. This study was informed by Simard's (2007) 'high touch' protocol based on the End-of-Life Namaste Care programme for people with dementia. The article is situated in relation to the research project which used a three-phase mixed methods approach. Data explored in this article are derived from focus groups conducted at three residential aged care facilities located in metropolitan and regional areas of NSW, Australia. The exploration of touch vis-a-vis mental health fell under two broad themes: touch by others and touch by the person. Sub-elements of these themes comprised touch towards a physical objective, touch towards an emotional objective, touch of objects and touch of others. The overarching outcome of interconnectedness embraced environmental awareness and human and life awareness. These two broad themes, with their accompanying elements, express the essential nature of mental health as a reciprocal connectedness, with reciprocal impacts on both those people with advanced dementia and their carers.

Social capital, socioeconomic status, and depression in community-living elderly.

PubMed

Han, Kyu-Man; Han, Changsu; Shin, Cheolmin; Jee, Hee-Jung; An, Hyonggin; Yoon, Ho-Kyoung; Ko, Young-Hoon; Kim, Seung-Hyun

2018-03-01

A growing body of evidence has suggested that social capital is an upstream social determinant of mental health. We investigated the association of cognitive social capital, including interpersonal trust and reciprocity, with depressive symptoms in the elderly. We also explored the mediating role of cognitive social capital in the association between socioeconomic status (SES) and depressive symptoms and the moderating effect of SES on the relationship between social capital and depressive symptoms. Data from the 2012 Korea Welfare Panel Study (KOWEPS) was analyzed for 5969 participants aged 60 years or older. Cognitive components of social capital, including interpersonal trust and reciprocity, were evaluated using single-item questionnaires. Socioeconomic and health-related characteristics were investigated and depressive symptoms were evaluated by an 11-item version of the Center for Epidemiologic Studies Depression Scale. Low interpersonal trust and reciprocity levels were significantly associated with depressive symptoms in the elderly. Reciprocity level mediated the association between household income level and depressive symptoms. We did not observe any significant moderating effect of SES on the association between cognitive social capital and depressive symptoms. A significant association between cognitive social capital and depressive symptoms in Korean elderly was found. We elucidated how SES interacted with depressive symptoms through the mediation pathway of cognitive social capital using a representative sample of the Korean elderly population. Copyright © 2018. Published by Elsevier Ltd.

Selective Cooperation in the Supermarket : Field Experimental Evidence for Indirect Reciprocity.

PubMed

Lange, Florian; Eggert, Frank

2015-12-01

Numerous laboratory experiments suggest that mechanisms of indirect reciprocity might account for human cooperation. However, conclusive field data supporting the predictions of indirect reciprocity in everyday life situations is still scarce. Here, we attempt to compensate for this lack by examining the determinants of cooperative behavior in a German supermarket. Our methods were as follows: Confederates of the experimenter lined up at the checkout, apparently to buy a single item. As an act of cooperation, the waiting person in front (the potential helper) could allow the confederate to go ahead. By this means, the potential helper could take a cost (additional waiting time) by providing the confederate with a benefit (saved waiting time). We recorded the potential helpers' behavior and the number of items they purchased as a quantitative measure proportional to the confederate's benefit. Moreover, in a field experimental design, we varied the confederates' image by manipulating the item they purchased (beer vs. water). As predicted, the more waiting time they could save, the more likely the confederates were to receive cooperation. This relationship was moderated by the confederates' image. Cost-to-benefit ratios were required to be more favorable for beer-purchasing individuals to receive cooperation. Our results demonstrate that everyday human cooperation can be studied unobtrusively in the field and that cooperation among strangers is selective in a way that is consistent with current models of indirect reciprocity.

The UIC ICBG (University of Illinois at Chicago International Cooperative Biodiversity Group) Memorandum of Agreement: a model of benefit-sharing arrangement in natural products drug discovery and development.

PubMed

Soejarto, D D; Gyllenhaal, C; Fong, H H S; Xuan, L T; Hiep, N T; Hung, N V; Bich, T Q; Southavong, B; Sydara, K; Pezzuto, J M

2004-02-01

The Convention on Biodiversity mandates a new approach to the discovery of natural product drugs, one that incorporates concepts of national ownership of genetic resources, intellectual property rights in traditional knowledge, and sharing of economic benefits with countries that are the source of new natural products. The International Cooperative Biodiversity Group (ICBG) program was established to support experimentation in implementation of the Convention through development and execution of international agreements for bioprospecting. The agreement of one such ICBG program, between the University of Illinois at Chicago and institutions in Vietnam and Laos, is presented here. The core elements contained in the single, five-way Memorandum of Agreement are the arrangements for intellectual property rights, treatment of informed consent, and plans for benefit-sharing (including the sharing of short- and long-term royalty benefits, capacity building, and community reciprocity). Program participants were able to develop a practical and flexible agreement that satisfies the wishes of all institutions that are parties to it.

Performance of an on-chip superconducting circulator for quantum microwave systems

NASA Astrophysics Data System (ADS)

Chapman, Benjamin; Rosenthal, Eric; Moores, Bradley; Kerckhoff, Joseph; Mates, J. A. B.; Hilton, G. C.; Vale, L. R.; Ullom, J. N.; LalumíEre, Kevin; Blais, Alexandre; Lehnert, K. W.

Microwave circulators enforce a single propagation direction for signals in an electrical network. Unfortunately, commercial circulators are bulky, lossy, and cannot be integrated close to superconducting circuits because they require strong ( kOe) magnetic fields produced by permanent magnets. Here we report on the performance of an on-chip, active circulator for superconducting microwave circuits, which uses no permanent magnets. Non-reciprocity is achieved by actively modulating reactive elements around 100 MHz, giving roughly a factor of 50 in the separation between signal and control frequencies, which facilitates filtering. The circulator's active components are dynamically tunable inductors constructed with arrays of dc-SQUIDs in series. Array inductance is tuned by varying the magnetic flux through the SQUIDs with fields weaker than 1 Oe. Although the instantaneous bandwidth of the device is narrow, the operation frequency is tunable between 4 and 8 GHz. This presentation will describe the device's theory of operation and compare its measured performance to design goals. This work is supported by the ARO under contract W911NF-14-1-0079 and the National Science Foundation under Grant Number 1125844.

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

Hopkins, Rebecca J.; Lewis, K.; Desyaterik, Yury

Aerosols generated from burning different plant fuels were characterized to determine relationships between chemical, optical and physical properties. Single scattering albedo ({omega}) and Angstrom absorption coefficients ({alpha}{sub ap}) were measured using a photoacoustic technique combined with a reciprocal nephelometer. Carbon-to-oxygen atomic ratios, sp{sup 2} hybridization, elemental composition and morphology of individual particles were measured using scanning transmission X-ray microscopy coupled with near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS) and scanning electron microscopy with energy dispersion of X-rays (SEM/EDX). Particles were grouped into three categories based on sp2 hybridization and chemical composition. Measured {omega} (0.4-1.0 at 405 nm) and {alpha}{sub ap}more » (1.0-3.5) values displayed a fuel dependence. The category with sp{sup 2} hybridization >80% had values of {omega} (<0.5) and {alpha}{sub ap} ({approx}1.25) characteristic of light absorbing soot. Other categories with lower sp2 hybridization (20 to 60%) exhibited higher {omega} (>0.8) and {alpha}{sub ap} (1.0 to 3.5) values, indicating increased absorption spectral selectivity.« less

Multiplexity and multireciprocity in directed multiplexes.

PubMed

Gemmetto, Valerio; Squartini, Tiziano; Picciolo, Francesco; Ruzzenenti, Franco; Garlaschelli, Diego

2016-10-01

Real-world multilayer networks feature nontrivial dependencies among links of different layers. Here we argue that if links are directed, then dependencies are twofold. Besides the ordinary tendency of links of different layers to align as the result of "multiplexity," there is also a tendency to antialign as a result of what we call "multireciprocity," i.e., the fact that links in one layer can be reciprocated by opposite links in a different layer. Multireciprocity generalizes the scalar definition of single-layer reciprocity to that of a square matrix involving all pairs of layers. We introduce multiplexity and multireciprocity matrices for both binary and weighted multiplexes and validate their statistical significance against maximum-entropy null models that filter out the effects of node heterogeneity. We then perform a detailed empirical analysis of the world trade multiplex (WTM), representing the import-export relationships between world countries in different commodities. We show that the WTM exhibits strong multiplexity and multireciprocity, an effect which is, however, largely encoded into the degree or strength sequences of individual layers. The residual effects are still significant and allow us to classify pairs of commodities according to their tendency to be traded together in the same direction and/or in opposite ones. We also find that the multireciprocity of the WTM is significantly lower than the usual reciprocity measured on the aggregate network. Moreover, layers with low (high) internal reciprocity are embedded within sets of layers with comparably low (high) mutual multireciprocity. This suggests that, in the WTM, reciprocity is inherent to groups of related commodities rather than to individual commodities. We discuss the implications for international trade research focusing on product taxonomies, the product space, and fitness and complexity metrics.

Apically Extruded Debris in Curved Root Canals Using the WaveOne Gold Reciprocating and Twisted File Adaptive Systems.

PubMed

Boijink, Daiana; Costa, Débora Delai; Hoppe, Carolina Bender; Kopper, Patrícia Maria Polli; Grecca, Fabiana Saores

2018-06-13

The purpose of this study was to evaluate apical debris extrusion associated with different kinematics in curved root canals. Forty-five extracted mandibular molars with root curvature angles ranging between 20° and 40° and curvature radii <10 mm were randomly assigned to 3 groups (n = 15) according to the kinematics used for root canal preparation: reciprocating motion with the WaveOne Gold system (Dentsply Tulsa Dental, Tulsa, OK), rotary/reciprocating motion with the Twisted File Adaptive system (SybronEndo, Orange, CA), and the manual technique. The debris apically extruded during preparation was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The extruded debris was quantified by subtracting the preinstrumentation from the postinstrumentation weight of the Eppendorf tubes. The time required for each instrumentation procedure was recorded. Data were analyzed using 1-way analysis of variance Tukey post hoc tests (∝ = 0.05). The WaveOne Gold reciprocating single-file system was associated with less extrusion of debris compared with hand files (P < .05) and the Twisted File Adaptive system (P > .05). The preparation time required by hand files was significantly longer than that required by the other techniques (P < .05). Under the conditions of this study, all of the instrumentation systems caused apical debris extrusion to some degree. The WaveOne Gold reciprocating system was associated with less debris extrusion in curved root canals compared with the manual technique and the Twisted File Adaptive system although the difference between the WaveOne Gold and Twisted File Adaptive systems was not significant. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Crossed reciprocal inhibition evoked by electrical stimulation of the lamprey spinal cord.

PubMed

Fagerstedt, P; Zelenin, P V; Deliagina, T G; Orlovsky, G N; Grillner, S

2000-09-01

Activation of a motoneuron pool is often accompanied by inhibition of the antagonistic pool through a system of reciprocal inhibition between the two parts of the neuronal network controlling the antagonistic pools. In the present study, we describe the activity of such a system in the isolated spinal cord of the lamprey, when a tonic motor output is evoked by extracellular stimulation (0.5-1 s train of pulses, 20 Hz) of either end of the spinal cord. With two electrodes symmetrically positioned in relation to the midline, stimulation with either of them separately elicited prolonged (1-5 s) ipsilateral ventral root activity. Activity could be abolished by stronger, simultaneously applied, stimulation of the contralateral side of the cord, suggesting that reciprocal inhibition between hemisegments operates when a tonic motor output is generated. Simultaneous stimulation of both sides of the spinal cord with a single electrode with a large tip (300-400 microm in diameter), positioned over the anatomical midline, elicited inconsistent right-side, leftside, or bilateral ventral root responses. A minor displacement (10-20 microm) to the left or right from the midline resulted in activation of ipsilateral motoneurons, whereas the contralateral motoneurons were silent. These findings indicate that a small asymmetry in the excitatory drive to the left and right spinal hemisegments can be further amplified by reciprocal inhibition between the hemisegments. Longitudinal splitting of the spinal cord along the midline resulted in reduced reciprocal inhibition between the hemisegments separated by the lesion. The reduction was proportional to the extent of the split. The inhibition was abolished when the split reached nine segments in length. From these experiments, the longitudinal distribution of the commissural axons responsible for inhibition of contralateral motor output could be estimated.

Study of a MHEMT heterostructure with an In{sub 0.4}Ga{sub 0.6}As channel MBE-grown on a GaAs substrate using reciprocal space mapping

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

Aleshin, A. N., E-mail: a.n.aleshin@mail.ru; Bugaev, A. S.; Ermakova, M. A.

2015-08-15

The crystallographic characteristics of the design elements of a metamorphic high-electron-mobility (MHEMT) heterostructure with an In{sub 0.4}Ga{sub 0.6}As channel are determined based on reciprocal space mapping. The heterostructure is grown by molecular beam epitaxy on the vicinal surface of a GaAs substrate with a deviation angle from the (001) plane of 2° and consists of a stepped metamorphic buffer containing six layers including an inverse step, a high-temperature buffer layer with constant composition, and active HEMT layers. The InAs content in the layers of the metamorphic buffer is varied from 0.1 to 0.48. Reciprocal space maps are constructed for themore » (004) symmetric reflection and (224)+ asymmetric reflection. It is found that the heterostructure layers are characterized both by a tilt angle relative to the plane of the (001) substrate and a rotation angle around the [001] axis. The tilt angle of the layer increases as the InAs concentration in the layer increases. It is shown that a high-temperature buffer layer of constant composition has the largest degree of relaxation compared with all other layers of the heterostructure.« less

Germ line insertion of mtDNA at the breakpoint junction of a reciprocal constitutional translocation.

PubMed

Willett-Brozick, J E; Savul, S A; Richey, L E; Baysal, B E

2001-08-01

Constitutional chromosomal translocations are relatively common causes of human morbidity, yet the DNA double-strand break (DSB) repair mechanisms that generate them are incompletely understood. We cloned, sequenced and analyzed the breakpoint junctions of a familial constitutional reciprocal translocation t(9;11)(p24;q23). Within the 10-kb region flanking the breakpoints, chromosome 11 had 25% repeat elements, whereas chromosome 9 had 98% repeats, 95% of which were L1-type LINE elements. The breakpoints occurred within an L1-type repeat element at 9p24 and at the 3'-end of an Alu sequence at 11q23. At the breakpoint junction of derivative chromosome 9, we discovered an unusually large 41-bp insertion, which showed 100% identity to 12S mitochondrial DNA (mtDNA) between nucleotides 896 and 936 of the mtDNA sequence. Analysis of the human genome failed to show the preexistence of the inserted sequence at normal chromosomes 9 and 11 breakpoint junctions or elsewhere in the genome, strongly suggesting that the insertion was derived from human mtDNA and captured into the junction during the DSB repair process. To our knowledge, these findings represent the first observation of spontaneous germ line insertion of modern human mtDNA sequences and suggest that DSB repair may play a role in inter-organellar gene transfer in vivo. Our findings also provide evidence for a previously unrecognized insertional mechanism in human, by which non-mobile extra-chromosomal fragments can be inserted into the genome at DSB repair junctions.

Temperature increases on the external root surface during endodontic treatment using single file systems.

PubMed

Özkocak, I; Taşkan, M M; Gökt Rk, H; Aytac, F; Karaarslan, E Şirin

2015-01-01

The aim of this study is to evaluate increases in temperature on the external root surface during endodontic treatment with different rotary systems. Fifty human mandibular incisors with a single root canal were selected. All root canals were instrumented using a size 20 Hedstrom file, and the canals were irrigated with 5% sodium hypochlorite solution. The samples were randomly divided into the following three groups of 15 teeth: Group 1: The OneShape Endodontic File no.: 25; Group 2: The Reciproc Endodontic File no.: 25; Group 3: The WaveOne Endodontic File no.: 25. During the preparation, the temperature changes were measured in the middle third of the roots using a noncontact infrared thermometer. The temperature data were transferred from the thermometer to the computer and were observed graphically. Statistical analysis was performed using the Kruskal-Wallis analysis of variance at a significance level of 0.05. The increases in temperature caused by the OneShape file system were lower than those of the other files (P < 0.05). The WaveOne file showed the highest temperature increases. However, there were no significant differences between the Reciproc and WaveOne files. The single file rotary systems used in this study may be recommended for clinical use.

Indium droplet formation in InGaN thin films with single and double heterojunctions prepared by MOCVD

PubMed Central

2014-01-01

Indium gallium nitride (InGaN) samples with single heterojunction (SH) and double heterojunction (DH) were prepared using metal-organic chemical vapor deposition. SH has a layer of InGaN thin film (thicknesses, 25, 50, 100, and 200 nm) grown on an uGaN film (thickness, 2 μm). The DH samples are distinguished by DH uGaN film (thickness, 120 nm) grown on the InGaN layer. Reciprocal space mapping measurements reveal that the DH samples are fully strained with different thicknesses, whereas the strain in the SH samples are significantly relaxed with the increasing thickness of the InGaN film. Scanning electron microscopy results show that the surface roughness of the sample increases when the sample is relaxed. High-resolution transmission electron microscopy images of the structure of indium droplets in the DH sample indicate that the thickness of the InGaN layer decreases with the density of indium droplets. The formation of these droplets is attributed to the insufficient kinetic energy of indium atom to react with the elements of group V, resulting to aggregation. The gallium atoms in the GaN thin film will not be uniformly replaced by indium atoms; the InGaN thin film has an uneven distribution of indium atoms and the quality of the epitaxial layer is degraded. PMID:25024692

[In vitro study of shaping ability of single-file techniques in curved canals].

PubMed

Zeng, Yajie; Gu, Lisha; Cai, Yanling; Chen, Dian; Wei, Xi

2014-11-01

To compare the shaping quality in curved canals of two single-file technique systems with other two traditional full-sequential systems. Eighty mature molar canals with the curvature between 20 and 45 degrees were randomly divided into four groups. Specimens in each group were prepared to size 25 at working length using A (Reciproc), B (OneShape), C (MTwo) and D (Revo S), respectively. Each canal was scanned by micro-computed tomography before and after preparation. Parameters including changes in dentine volume, percentage of uninstrumented area, degree and tendency of transportation were analyzed. The operating time was also recorded. In full canal length, there was no difference in canal dentine removal, instrumented percentage and transportation degree among four groups (P > 0.05). In the apical 4 mm region, group A removed more dentine [(2.14±0.76) mm(2) of canal surface area and (0.38 ± 0.15) mm(3) of canal volume] than groups B and C(P < 0.05). At 1 mm level, median of transportation degree of group A was 0.05 (0.03)mm, which was smaller than other groups (P < 0.05). Groups A and B took (86.3±24.6) s and (85.9±21.3) s, while groups C and D took (147.4±28.3) s and (126.3±27.7) s srespectively to finish preparation. Single file techniques were significantly faster than the two full-sequential systems (P < 0.01). Compared with the continuous rotary systems, the reciprocating single-file system A showed better apical shaping ability. Both single-file techniques were more efficient than full-sequential systems for curved canal preparation. Single-file techniques appear to be the effective and efficient method for curved canal preparation.

Belief in reciprocity in a Chinese sample.

PubMed

Zhang, Zhen; Zhang, Jianxin

2012-08-01

Belief in reciprocity refers to a personally internalized faith in the reciprocity norm: that people will return positive and negative interactions or favors in kind. The current study aims to examine the relationship between belief in reciprocity and altruism among a Chinese sample. The Personal Norm of Reciprocity Scale, Trait Forgiveness Scale, Prosocial Tendency Measure, and Altruism Scale were used to assess extent of belief in reciprocity, forgiveness, and prosocial motivation, respectively, among 204 Chinese undergraduates. The results indicated that belief in reciprocity was a partially negative, but not neutral, reciprocity norm for Chinese people. Specifically, belief in reciprocity was positively related to negative reciprocity, but not significantly related to positive reciprocity. Moreover, belief in reciprocity was negatively related to both prosocial tendency and altruistic motivation. The results also indicated that forgiveness largely mediated the effect of belief in reciprocity on altruism. Finally, the implications and limitations of the current study were discussed.

Reciprocity in spatial evolutionary public goods game on double-layered network

NASA Astrophysics Data System (ADS)

Kim, Jinho; Yook, Soon-Hyung; Kim, Yup

2016-08-01

Spatial evolutionary games have mainly been studied on a single, isolated network. However, in real world systems, many interaction topologies are not isolated but many different types of networks are inter-connected to each other. In this study, we investigate the spatial evolutionary public goods game (SEPGG) on double-layered random networks (DRN). Based on the mean-field type arguments and numerical simulations, we find that SEPGG on DRN shows very rich interesting phenomena, especially, depending on the size of each layer, intra-connectivity, and inter-connected couplings, the network reciprocity of SEPGG on DRN can be drastically enhanced through the inter-connected coupling. Furthermore, SEPGG on DRN can provide a more general framework which includes the evolutionary dynamics on multiplex networks and inter-connected networks at the same time.

The LaueUtil toolkit for Laue photocrystallography. I. Rapid orientation matrix determination for intermediate-size-unit-cell Laue data

PubMed Central

Kalinowski, Jarosław A.; Makal, Anna; Coppens, Philip

2011-01-01

A new method for determination of the orientation matrix of Laue X-ray data is presented. The method is based on matching of the experimental patterns of central reciprocal lattice rows projected on a unit sphere centered on the origin of the reciprocal lattice with the corresponding pattern of a monochromatic data set on the same material. This technique is applied to the complete data set and thus eliminates problems often encountered when single frames with a limited number of peaks are to be used for orientation matrix determination. Application of the method to a series of Laue data sets on organometallic crystals is described. The corresponding program is available under a Mozilla Public License-like open-source license. PMID:22199400

21. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model no. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. Steam-feed pipe at top left of engine. Steam exhaust pipe leaves base of engine on right end and projects upwards. The boiler feed and supply pipe running water through the engine's pre-heat system are seen running to the lower left end of the engine. Pulley in the foreground was not used. The centrifugals were powered by a belt running from the flywheel in the background. Ball-type governor and pulley are on left end of the engine. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Reciprocity in spatial evolutionary public goods game on double-layered network

PubMed Central

Kim, Jinho; Yook, Soon-Hyung; Kim, Yup

2016-01-01

Spatial evolutionary games have mainly been studied on a single, isolated network. However, in real world systems, many interaction topologies are not isolated but many different types of networks are inter-connected to each other. In this study, we investigate the spatial evolutionary public goods game (SEPGG) on double-layered random networks (DRN). Based on the mean-field type arguments and numerical simulations, we find that SEPGG on DRN shows very rich interesting phenomena, especially, depending on the size of each layer, intra-connectivity, and inter-connected couplings, the network reciprocity of SEPGG on DRN can be drastically enhanced through the inter-connected coupling. Furthermore, SEPGG on DRN can provide a more general framework which includes the evolutionary dynamics on multiplex networks and inter-connected networks at the same time. PMID:27503801

Subjective Caregiver Burden and Caregiver Satisfaction: The Role of Partner Relationship Quality and Reciprocity.

PubMed

Tough, Hannah; Brinkhof, Martin W; Siegrist, Johannes; Fekete, Christine

2017-10-01

To explore the effect of relationship quality and reciprocity in partnerships on subjective caregiver burden and caregiver satisfaction in partners of persons with a severe physical disability (spinal cord injury). Cross-sectional, observational. Community setting. Caregiving partners of persons with spinal cord injury (N=118). Not applicable. Subjective caregiver burden measured by the Zarit Burden Interview (short form) and caregiver satisfaction measured by a single item on feelings of satisfaction resulting from the caregiver role. Caregiving partners who rated their relationship quality as high encountered less subjective caregiver burden (β=-1.10; 95% confidence interval [CI], -1.47 to -0.72; P<.001) and more caregiver satisfaction (odds ratio [OR], 1.18; 95% CI, 1.01-1.45; P=.049). These associations persisted even after controlling for sociodemographic characteristics, lesion severity of the care receiver, and objective caregiver burden. Partners who indicated high reciprocity in their relationship to the care receiver indicated less subjective caregiver burden and more caregiver satisfaction when relationship quality was excluded from the final models; however, the effect of reciprocity on subjective burden (β=-.38; 95% CI, -3.71 to 2.95; P=.82) and caregiver satisfaction (OR, 1.21; 95% CI, 0.28-5.22; P=.80) disappeared when including relationship quality. Results highlight the importance of relationship quality as a target for couple interventions aimed at reducing subjective caregiver burden and increasing satisfaction in the caregiving role. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Comparison of postoperative pain after root canal treatment using reciprocating instruments based on operator’s experience: A prospective clinical study

PubMed Central

Duran-Sindreu, Fernando; Calvo, Carmen; Basilio, Juan; Abella, Fransesc; Ali, Akram; Roig, Miguel; Olivieri, Juan-Gonzalo

2017-01-01

Background The aim of the present study was to compare clinically the incidence of postoperative pain after endodontic treatment using the Reciproc System, taking into account the operator’s experience. Material and Methods One hundred patients scheduled for routine endodontic treatment were enrolled in this study. Endodontic treatment was carried out in a single visit by undergraduate and postgraduate students. The chemomechanical preparation of root canals was performed with Reciproc instruments. Pretreatment and postoperative pain was recorded using a visual analogue scale (VAS). Postoperative pain and the need for analgesic consumption were assessed at 4, 8, 16, 24, 48 and 72 hours post-treatment. The data were analyzed using the Mann–Whitney U and Chi-Square test, and the significance was set at P<0.05. Results The mean value of pain after root canal treatment was 1.13±1.94 and 1.91±2.07 on a VAS between 0 and 10 in treatments performed by undergraduate and postgraduate students, respectively. There was a significant difference in the incidence of postoperative pain between the two groups (P<0.05). Conclusions The prevalence of postoperative pain was high in the treatments performed by postgraduate students in comparison with undergraduate students. This suggests that operator experience has an influence on the prevalence of postoperative pain after root canal treatment. Key words:Post-endodontic pain, root canal treatment, reciprocating systems, Expert operators Inexperienced operators. PMID:28828152

Expanding Lorentz and spectrum corrections to large volumes of reciprocal space for single-crystal time-of-flight neutron diffraction. Corrigendum

DOE PAGES

Michels-Clark, Tara M.; Savici, Andrei T.; Lynch, Vickie E.; ...

2017-09-25

The author list is amended with the addition of Michal Chodkiewicz, Thomas Weber and Hans-Beat Bürgi. Here, the complete list of authors is Tara Michels-Clark, Andrei Savici, Vickie Lynch, Xiaoping Wang, Michal Chodkiewicz, Thomas Weber, Hans-Beat Bürgi and Christina Hoffmann.

Living the Ethics of Responsibility through University Service and Service-Learning: "Phronesis" and "Praxis" Reconsidered

ERIC Educational Resources Information Center

Lukenchuk, Anotonina

2009-01-01

This article considers the notion of service-learning (SL) as essentially different from other similar activities, such as philanthropy, charity, voluntarism, or a single act of kindness which are "one-way" socially engaged activities. Service-learning is different because it necessarily entails reciprocity and mutuality which are "two-way"…

Expanding Lorentz and spectrum corrections to large volumes of reciprocal space for single-crystal time-of-flight neutron diffraction. Corrigendum

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

Michels-Clark, Tara M.; Savici, Andrei T.; Lynch, Vickie E.

The author list is amended with the addition of Michal Chodkiewicz, Thomas Weber and Hans-Beat Bürgi. Here, the complete list of authors is Tara Michels-Clark, Andrei Savici, Vickie Lynch, Xiaoping Wang, Michal Chodkiewicz, Thomas Weber, Hans-Beat Bürgi and Christina Hoffmann.

Research to Develop Effective Teaching and Management Techniques for Severely Disturbed and Retarded Children. Final Report.

ERIC Educational Resources Information Center

Kauffman, James M.; Birnbrauer, Jay S.

The final report of a project on teaching and management techniques with severely disturbed and/or retarded children presents analysis of single subject research using contingent imitation of the child as an intervention technique. The effects of this technique were examined on the following behaviors: toyplay and reciprocal imitation, self…

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

Nitao, J J

The goal of the Event Reconstruction Project is to find the location and strength of atmospheric release points, both stationary and moving. Source inversion relies on observational data as input. The methodology is sufficiently general to allow various forms of data. In this report, the authors will focus primarily on concentration measurements obtained at point monitoring locations at various times. The algorithms being investigated in the Project are the MCMC (Markov Chain Monte Carlo), SMC (Sequential Monte Carlo) Methods, classical inversion methods, and hybrids of these. They refer the reader to the report by Johannesson et al. (2004) for explanationsmore » of these methods. These methods require computing the concentrations at all monitoring locations for a given ''proposed'' source characteristic (locations and strength history). It is anticipated that the largest portion of the CPU time will take place performing this computation. MCMC and SMC will require this computation to be done at least tens of thousands of times. Therefore, an efficient means of computing forward model predictions is important to making the inversion practical. In this report they show how Green's functions and reciprocal Green's functions can significantly accelerate forward model computations. First, instead of computing a plume for each possible source strength history, they can compute plumes from unit impulse sources only. By using linear superposition, they can obtain the response for any strength history. This response is given by the forward Green's function. Second, they may use the law of reciprocity. Suppose that they require the concentration at a single monitoring point x{sub m} due to a potential (unit impulse) source that is located at x{sub s}. instead of computing a plume with source location x{sub s}, they compute a ''reciprocal plume'' whose (unit impulse) source is at the monitoring locations x{sub m}. The reciprocal plume is computed using a reversed-direction wind field. The wind field and transport coefficients must also be appropriately time-reversed. Reciprocity says that the concentration of reciprocal plume at x{sub s} is related to the desired concentration at x{sub m}. Since there are many less monitoring points than potential source locations, the number of forward model computations is drastically reduced.« less

Generation of Tandem Direct Duplications by Reversed-Ends Transposition of Maize Ac Elements

PubMed Central

Peterson, Thomas

2013-01-01

Tandem direct duplications are a common feature of the genomes of eukaryotes ranging from yeast to human, where they comprise a significant fraction of copy number variations. The prevailing model for the formation of tandem direct duplications is non-allelic homologous recombination (NAHR). Here we report the isolation of a series of duplications and reciprocal deletions isolated de novo from a maize allele containing two Class II Ac/Ds transposons. The duplication/deletion structures suggest that they were generated by alternative transposition reactions involving the termini of two nearby transposable elements. The deletion/duplication breakpoint junctions contain 8 bp target site duplications characteristic of Ac/Ds transposition events, confirming their formation directly by an alternative transposition mechanism. Tandem direct duplications and reciprocal deletions were generated at a relatively high frequency (∼0.5 to 1%) in the materials examined here in which transposons are positioned nearby each other in appropriate orientation; frequencies would likely be much lower in other genotypes. To test whether this mechanism may have contributed to maize genome evolution, we analyzed sequences flanking Ac/Ds and other hAT family transposons and identified three small tandem direct duplications with the structural features predicted by the alternative transposition mechanism. Together these results show that some class II transposons are capable of directly inducing tandem sequence duplications, and that this activity has contributed to the evolution of the maize genome. PMID:23966872

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

Itagaki, Masafumi; Miyoshi, Yoshinori; Hirose, Hideyuki

A procedure is presented for the determination of geometric buckling for regular polygons. A new computation technique, the multiple reciprocity boundary element method (MRBEM), has been applied to solve the one-group neutron diffusion equation. The main difficulty in applying the ordinary boundary element method (BEM) to neutron diffusion problems has been the need to compute a domain integral, resulting from the fission source. The MRBEM has been developed for transforming this type of domain integral into an equivalent boundary integral. The basic idea of the MRBEM is to apply repeatedly the reciprocity theorem (Green's second formula) using a sequence ofmore » higher order fundamental solutions. The MRBEM requires discretization of the boundary only rather than of the domain. This advantage is useful for extensive survey analyses of buckling for complex geometries. The results of survey analyses have indicated that the general form of geometric buckling is B[sub g][sup 2] = (a[sub n]/R[sub c])[sup 2], where R[sub c] represents the radius of the circumscribed circle of the regular polygon under consideration. The geometric constant A[sub n] depends on the type of regular polygon and takes the value of [pi] for a square and 2.405 for a circle, an extreme case that has an infinite number of sides. Values of a[sub n] for a triangle, pentagon, hexagon, and octagon have been calculated as 4.190, 2.281, 2.675, and 2.547, respectively.« less

Cyclic Fatigue Resistance of Reciproc Blue and Reciproc Files in an S-shaped Canal.

PubMed

Topçuoğlu, Hüseyin Sinan; Topçuoğlu, Gamze

2017-10-01

This study evaluated the cyclic fatigue resistance (CFR) of Reciproc (R25 and R40; VDW, Munich, Germany) and Reciproc Blue (R25 and R40, VDW) instruments used in an artificial S-shaped canal. A total of 80 files were tested in an S-shaped canal (n = 20 for each file, Reciproc R25 and R40 and Reciproc Blue R25 and R40). This study compared Reciproc R25 with Reciproc Blue R25 files and Reciproc R40 with Reciproc Blue R40 files. All files were rotated in an S-shaped artificial canal until fracture. CFR was determined by recording the time to fracture in the artificial canal. The length of each fractured fragment was measured in millimeters. An independent sample t test was used to analyze the data. Between the R25 files, Reciproc Blue instruments showed significantly greater CFR than the Reciproc files in the apical and coronal curves (P < .05). Between the R40 files, Reciproc Blue instruments exhibited greater CFR in the apical and coronal curves (P < .05). There was no difference in the fractured fragment lengths of the Reciproc Blue files compared with the Reciproc files (P > .05). The Reciproc Blue R25 and R40 files showed greater CFR than the Reciproc R25 and R40 files in an S-shaped canal. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Root canal anatomy preservation of WaveOne reciprocating files with or without glide path.

PubMed

Berutti, Elio; Paolino, Davide Salvatore; Chiandussi, Giorgio; Alovisi, Mario; Cantatore, Giuseppe; Castellucci, Arnaldo; Pasqualini, Damiano

2012-01-01

This study evaluated the influence of glide path on canal curvature and axis modification after instrumentation with WaveOne Primary reciprocating files. Thirty ISO 15, 0.02 taper Endo Training Blocks were used. In group 1, glide path was created with PathFile 1, 2, and 3 at working length, whereas in group 2, glide path was not performed. In both groups, canals were shaped with WaveOne Primary reciprocating files at working length. Preinstrumentation and postinstrumentation digital images were superimposed and processed with Matlab r2010b software to analyze the curvature radius ratio (CRr) and the relative axis error (rAe), representing canal curvature modification. Data were analyzed with 1-way balanced analyses of variance at 2 levels (P < .05). Glide path was found to be extremely significant for both CRr parameter (F = 9.59; df = 1; P = .004) and rAe parameter (F = 13.55; df = 1; P = .001). Canal modifications seem to be significantly reduced when previous glide path is performed by using the new WaveOne nickel-titanium single-file system. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Modulation of dendrodendritic interactions and mitral cell excitability in the mouse accessory olfactory bulb by vaginocervical stimulation.

PubMed

Otsuka, T; Ishii, K; Osako, Y; Okutani, F; Taniguchi, M; Oka, T; Kaba, H

2001-05-01

When female mice are mated, they form a memory to the pheromonal signal of their male partner. The neural changes underlying this memory occur in the accessory olfactory bulb, depend upon vaginocervical stimulation at mating and involve changes at the reciprocal synapses between mitral and granule cells. However, the action of vaginocervical stimulation on the reciprocal interactions between mitral and granule cells remains to be elucidated. We have examined the effects of vaginocervical stimulation on paired-pulse depression of amygdala-evoked field potentials recorded in the external plexiform layer of the accessory olfactory bulb (AOB) and the single-unit activity of mitral cells antidromically stimulated from the amygdala in urethane-anaesthetized female mice. Artificial vaginocervical stimulation reduced paired-pulse depression (considered to be due to feedback inhibition of the mitral cell dendrites from the granule cells via reciprocal dendrodendritic synapses) recorded in the AOB external plexiform layer. As would be expected from this result, vaginocervical stimulation also enhanced the spontaneous activity of a proportion of the mitral cells tested. These results suggest that vaginocervical stimulation reduces dendrodendritic feedback inhibition to mitral cells and enhances their activity.

Promised and delivered inducements and contributions: an integrated view of psychological contract appraisal.

PubMed

Lambert, Lisa Schurer

2011-07-01

The reciprocal exchange of employees' work for pay that is central to employment relationships is viewed here through the lens of the psychological contract. A psychological contract involves promised inducements, promised contributions, delivered inducements, and delivered contributions: How an employee cognitively integrates these 4 elements is a central question in psychological contract theory. Three alternative approaches for integrating the 4 elements were drawn from discrepancy theory, from equity theory, and from need theories of satisfaction, respectively. Experimental findings disconfirmed the discrepancy and equity approaches. Findings were consistent with the premise of the needs model, which is that appraisal is driven by how psychological contract elements facilitate or hinder an employee's effort to fulfill personal needs. Results showed that promised and delivered pay and work contribute uniquely to appraisal but that they vary in their influence on appraisal. These findings were consistent with the needs model principle that elements proximal to need satisfaction matter more than distal elements. That is, what is delivered (for pay and for work) matters more than what is promised, and pay matters more than work.

Effects of Macrophage Depletion on Sleep in Mice

PubMed Central

Ames, Conner; Boland, Erin; Szentirmai, Éva

2016-01-01

The reciprocal interaction between the immune system and sleep regulation has been widely acknowledged but the cellular mechanisms that underpin this interaction are not completely understood. In the present study, we investigated the role of macrophages in sleep loss- and cold exposure-induced sleep and body temperature responses. Macrophage apoptosis was induced in mice by systemic injection of clodronate-containing liposomes (CCL). We report that CCL treatment induced an immediate and transient increase in non-rapid-eye movement sleep (NREMS) and fever accompanied by decrease in rapid-eye movement sleep, motor activity and NREMS delta power. Chronically macrophage-depleted mice had attenuated NREMS rebound after sleep deprivation compared to normal mice. Cold-induced increase in wakefulness and decrease in NREMS, rapid-eye movement sleep and body temperature were significantly enhanced in macrophage-depleted mice indicating increased cold sensitivity. These findings provide further evidence for the reciprocal interaction among the immune system, sleep and metabolism, and identify macrophages as one of the key cellular elements in this interplay. PMID:27442442

On-chip microwave circulators using quantum Hall plasmonics

NASA Astrophysics Data System (ADS)

Mahoney, Alice; Colless, James; Pauka, Sebastian; Hornibrook, John; Doherty, Andrew; Reilly, David; Peeters, Lucas; Fox, Eli; Goldhaber-Gordon, David; Kou, Xuefeng; Pan, Lei; Wang, Kang; Watson, John; Gardner, Geoffrey; Manfra, Michael

Circulators are directional circuit elements integral to technologies including radar systems, microwave communication transceivers and the readout of quantum information devices. Their non-reciprocity commonly arises from the interference of microwaves over the centimetre-scale of the signal wavelength in the presence of bulky magnetic media that breaks time-reversal symmetry. We present a completely passive on-chip microwave circulator with size 1/1000th the wavelength by exploiting the chiral, `slow-light' response of a GaAs/AlGaAs 2-dimensional electron gas in the quantum Hall regime. Further, by implementing this circulator design on a thin film of a magnetic topological insulator (Cr0.12(Bi0.26Sb0.62)2Te3), we show that similar non-reciprocity can be achieved at zero magnetic field. This additional mode of operation serves as a non-invasive probe of edge states in the quantum anomalous Hall effect, while also extending the possibility for integration with superconducting devices.

Fully nonlocal inelastic scattering computations for spectroscopical transmission electron microscopy methods

NASA Astrophysics Data System (ADS)

Rusz, Ján; Lubk, Axel; Spiegelberg, Jakob; Tyutyunnikov, Dmitry

2017-12-01

The complex interplay of elastic and inelastic scattering amenable to different levels of approximation constitutes the major challenge for the computation and hence interpretation of TEM-based spectroscopical methods. The two major approaches to calculate inelastic scattering cross sections of fast electrons on crystals—Yoshioka-equations-based forward propagation and the reciprocal wave method—are founded in two conceptually differing schemes—a numerical forward integration of each inelastically scattered wave function, yielding the exit density matrix, and a computation of inelastic scattering matrix elements using elastically scattered initial and final states (double channeling). Here, we compare both approaches and show that the latter is computationally competitive to the former by exploiting analytical integration schemes over multiple excited states. Moreover, we show how to include full nonlocality of the inelastic scattering event, neglected in the forward propagation approaches, at no additional computing costs in the reciprocal wave method. Detailed simulations show in some cases significant errors due to the z -locality approximation and hence pitfalls in the interpretation of spectroscopical TEM results.

The study of the mechanisms of the different phenotypical manifestations in patients with reciprocal translocations

NASA Astrophysics Data System (ADS)

Lozynskyi, Rostyslav; Lozynska, Maria

2006-04-01

Cytogenetical study of lymphocytes using the light microscopy could reveal a large amount of chromosomal abnormalities, which determine corresponding hereditary disorders. However, geneticists sometimes observe the cases where the same chromosomal rearrangements seen in light microscope cause quite different phenotype (from normal to abnormal) in relatives. The aim of the study was to explain the mechanisms of the different phenotype appearance in family members carrying the same reciprocal translocations. It was carried out the standard chromosome analysis in 12 families, where some relatives had reciprocal translocations. Chromosomes were differentially stained using G-method. The samples were analysed in optical microscope (x1000). Using OMIM gene map, UCSC Genome Browser, eGenome Release v2.3 and Unigene databases it was revealed transposons and transposon derivates in chromosome regions involved in translocations. We suppose that the variability of clinical manifestations in translocation-bearing patient is caused by the influence of the transposons, such as Hsmar2, Alu-elements or some others. We propose the following mechanisms of transposone action in these patients. The first may lie on recombination between the 2 specific DNA-transposon containing sites on different chromosomes resulting in balanced reciprocal translocation with no significant influence on the most genes' activity in corresponding regions. The weakening of transposase repression, which may follow in gametes, increases the transposase activity, and hereby, the probability of transposon dislocation. Dislocation can change the activity of groups of genes, because transposons often carry the regulatory sequences. This can induce multiply innate disorders in the progeny of the phenotypically healthy parents, carrying the translocation. According to the second mechanism, the reciprocal translocation is caused by recombination between 2 Alu repeats. These repeats can undergo reverse transcription, and a DNA-product, formed during this process, can paste in a new chromosome region in gametes. As the Alu repeats contain the CpG-islands, they can change the gene activity resulting in a disorder. The understanding of the cases of such genetical disorders might help to predict the appearance of the progeny with pathological karyotype, making the light microscopy more informative in diagnostic of the diseases.

Mechanical seal having a single-piece, perforated mating ring

DOEpatents

Khonsari, Michael M [Baton Rouge, LA; Somanchi, Anoop K [Fremont, CA

2007-08-07

A mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) with reduced contact surface temperature, reduced contact surface wear, or increased life span. The mechanical seal comprises a rotating ring and a single-piece, perforated mating ring, which improves heat transfer by controllably channeling coolant flow through the single-piece mating ring such that the coolant is in substantially uniform thermal contact with a substantial portion of the interior surface area of the seal face, while maintaining the structural integrity of the mechanical seal and minimizing the potential for coolant flow interruptions to the seal face caused by debris or contaminants (e.g., small solids and trash) in the coolant.

The incidence of root microcracks caused by 3 different single-file systems versus the ProTaper system.

PubMed

Liu, Rui; Hou, Ben Xiang; Wesselink, Paul R; Wu, Min-Kai; Shemesh, Hagay

2013-08-01

The aim of this study was to compare the incidence of root cracks observed at the apical root surface and/or in the canal wall after canal instrumentation with 3 single-file systems and the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland). One hundred mandibular incisors were selected. Twenty control teeth were coronally flared with Gates-Glidden drills (Dentsply Maillefer). No further preparation was made. The other 80 teeth were mounted in resin blocks with simulated periodontal ligaments, and the apex was exposed. They were divided into 4 experimental groups (n = 20); the root canals were first coronally flared with Gates-Glidden drills and then instrumented to the full working length with the ProTaper, OneShape (Micro-Mega, Besancon, France), Reciproc (VDW, Munich, Germany), or the Self-Adjusting File (ReDent-Nova, Ra'anana, Israel). The apical root surface and horizontal sections 2, 4, and 6 mm from the apex were observed under a microscope. The presence of cracks was noted. The chi-square test was performed to compare the appearance of cracked roots between the experimental groups. No cracks were found in the control teeth and teeth instrumented with the Self-Adjusting File. Cracks were found in 10 of 20 (50%), 7 of 20 (35%), and 1 of 20 (5%) teeth after canal instrumentation with the ProTaper, OneShape, and Reciproc files, respectively. The difference between the experimental groups was statistically significant (P < .001). Nickel-titanium instruments may cause cracks on the apical root surface or in the canal wall; the Self-Adjusting File and Reciproc files caused less cracks than the ProTaper and OneShape files. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comprehensive model of a hermetic reciprocating compressor

NASA Astrophysics Data System (ADS)

Yang, B.; Ziviani, D.; Groll, E. A.

2017-08-01

A comprehensive simulation model is presented to predict the performance of a hermetic reciprocating compressor and to reveal the underlying mechanisms when the compressor is running. The presented model is composed of sub-models simulating the in-cylinder compression process, piston ring/journal bearing frictional power loss, single phase induction motor and the overall compressor energy balance among different compressor components. The valve model, leakage through piston ring model and in-cylinder heat transfer model are also incorporated into the in-cylinder compression process model. A numerical algorithm solving the model is introduced. The predicted results of the compressor mass flow rate and input power consumption are compared to the published compressor map values. Future work will focus on detailed experimental validation of the model and parametric studies investigating the effects of structural parameters, including the stroke-to-bore ratio, on the compressor performance.

8. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model No. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. It received steam from the locomotive type, fire-tube portable boiler in the background. The engine's water pump which pumped water from the feed-water clarifying cistern, in between the boiler and engine, through a pre-heat system and on to the boiler, is seen in front of the fluted cylinder. The fly-ball governor, missing its balls, the steam port, and manual throttle valve are above and behind the cylinder. The flywheel, drive shaft, and pulley are on the left side of the engine bed. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Microfabrication of low-loss lumped-element Josephson circuits for non-reciprocal and parametric devices

NASA Astrophysics Data System (ADS)

Cicak, Katarina; Lecocq, Florent; Ranzani, Leonardo; Peterson, Gabriel A.; Kotler, Shlomi; Teufel, John D.; Simmonds, Raymond W.; Aumentado, Jose

Recent developments in coupled mode theory have opened the doors to new nonreciprocal amplification techniques that can be directly leveraged to produce high quantum efficiency in current measurements in microwave quantum information. However, taking advantage of these techniques requires flexible multi-mode circuit designs comprised of low-loss materials that can be implemented using common fabrication techniques. In this talk we discuss the design and fabrication of a new class of multi-pole lumped-element superconducting parametric amplifiers based on Nb/Al-AlOx/Nb Josephson junctions on silicon or sapphire. To reduce intrinsic loss in these circuits we utilize PECVD amorphous silicon as a low-loss dielectric (tanδ 5 ×10-4), resulting in nearly quantum-limited directional amplification.

Does Parenting Explain the Effects of Structural Conditions on Children's Antisocial Behavior? A Comparison of Blacks and Whites.

ERIC Educational Resources Information Center

McLeod, Jane D.; And Others

1994-01-01

Data on black children and white children over age six and their mothers (from National Longitudinal Survey of Youth) indicate no racial differences in total effects of poverty and single parenthood on parenting practices (affection and spanking). Parenting practices were reciprocally related to child's antisocial behavior for whites, but did not…

Teaching the Imitation and Spontaneous Use of Descriptive Gestures in Young Children with Autism Using a Naturalistic Behavioral Intervention

ERIC Educational Resources Information Center

Ingersoll, Brooke; Lewis, Elizabeth; Kroman, Emily

2007-01-01

Children with autism exhibit deficits in the imitation and spontaneous use of descriptive gestures. Reciprocal Imitation Training (RIT), a naturalistic imitation intervention, has been shown to increase object imitation skills in young children with autism. A single-subject, multiple-baseline design across five young children with autism was used…

Three-dimensional magnetotelluric inversion including topography using deformed hexahedral edge finite elements, direct solvers and data space Gauss-Newton, parallelized on SMP computers

NASA Astrophysics Data System (ADS)

Kordy, M. A.; Wannamaker, P. E.; Maris, V.; Cherkaev, E.; Hill, G. J.

2014-12-01

We have developed an algorithm for 3D simulation and inversion of magnetotelluric (MT) responses using deformable hexahedral finite elements that permits incorporation of topography. Direct solvers parallelized on symmetric multiprocessor (SMP), single-chassis workstations with large RAM are used for the forward solution, parameter jacobians, and model update. The forward simulator, jacobians calculations, as well as synthetic and real data inversion are presented. We use first-order edge elements to represent the secondary electric field (E), yielding accuracy O(h) for E and its curl (magnetic field). For very low frequency or small material admittivity, the E-field requires divergence correction. Using Hodge decomposition, correction may be applied after the forward solution is calculated. It allows accurate E-field solutions in dielectric air. The system matrix factorization is computed using the MUMPS library, which shows moderately good scalability through 12 processor cores but limited gains beyond that. The factored matrix is used to calculate the forward response as well as the jacobians of field and MT responses using the reciprocity theorem. Comparison with other codes demonstrates accuracy of our forward calculations. We consider a popular conductive/resistive double brick structure and several topographic models. In particular, the ability of finite elements to represent smooth topographic slopes permits accurate simulation of refraction of electromagnetic waves normal to the slopes at high frequencies. Run time tests indicate that for meshes as large as 150x150x60 elements, MT forward response and jacobians can be calculated in ~2.5 hours per frequency. For inversion, we implemented data space Gauss-Newton method, which offers reduction in memory requirement and a significant speedup of the parameter step versus model space approach. For dense matrix operations we use tiling approach of PLASMA library, which shows very good scalability. In synthetic inversions we examine the importance of including the topography in the inversion and we test different regularization schemes using weighted second norm of model gradient as well as inverting for a static distortion matrix following Miensopust/Avdeeva approach. We also apply our algorithm to invert MT data collected at Mt St Helens.

Reciprocity Calibration in a Plane Wave Resonator.

DTIC Science & Technology

1985-12-01

300 N. Quincy St. (code 11121ELEMENT NO INO :4NO ACCESS~oN NO Arlington, Va. , zip. 22217 6 115 3N IR1108-0 384_-1 8 V0 14 351-R 7IT..E (include...room " temperature [22 deg C3 ----------------------- 66 1.7 Differential volume under consideration ----- 71 2.1 .-.Iified four port network...natural log of both sides and differentiate , V Equation 1.41 If the acoustic pressure is harmonic then it can be written as, * L 4 U j i OEquation

Shuttle plate braiding machine

NASA Technical Reports Server (NTRS)

Huey, Jr., Cecil O. (Inventor)

1994-01-01

A method and apparatus for moving yarn in a selected pattern to form a braided article. The apparatus includes a segmented grid of stationary support elements and a plurality of shuttles configured to carry yarn. The shuttles are supported for movement on the grid assembly and each shuttle includes a retractable plunger for engaging a reciprocating shuttle plate that moves below the grid assembly. Such engagement at selected times causes the shuttles to move about the grid assembly in a selected pattern to form a braided article of a particular geometry.

Comparative evaluation of root canal preparations of maxillary first molars with self-adjusting file, reciproc single file, and revo-s rotary file: A micro-computed tomography study.

PubMed

Ahmetoglu, Fuat; Keles, Ali; Simsek, Neslihan; Ocak, M Sinan; Yologlu, Saim

2015-01-01

This study was aimed to use micro-computed tomography (μ-CT) to evaluate the canal shaping properties of three nickel-titanium instruments, Self-Adjusting File (SAF), Reciproc, and Revo-S rotary file, in maxillary first molars. Thirty maxillary molars were scanned preoperatively by using micro-computed tomography (μ-CT) scans at 13,68 μm resolution. The teeth were randomly assigned to three groups (n = 10). The root canals were shaped with SAF, Reciproc, and Revo-S, respectively. The shaped root canals were rescanned. Changes in canal volumes and surface areas were compared with preoperative values. The data were analyzed using Kruskal-Wallis and Conover's post hoc tests, with p < .05 denoting a statistically significant difference. Preoperatively canal volumes and surface area were statistically similar among the three groups (p > .05). There were statistically significant differences in all measures comparing preoperative and postoperative canal models (p = 0.0001). These differences occurred after instrumentation among the three experimental groups showed no statistically significant difference for volume (p > .05). Surface area showed the similar activity in buccal canals in each of the three techniques whereas no statistically significant difference was detected among surface area, the SAF, and the Revo-S in the palatal (P) canal. Each of three shaping system showed the similar volume activity in all canals, but SAF and Revo-S provided more effectively root planning in comparison with Reciproc in P canal. © Wiley Periodicals, Inc.

Eye investigation with optical microradar techniques

NASA Astrophysics Data System (ADS)

Molebny, Vasyl V.; Pallikaris, Ioannis G.; Naoumidis, Leonidas P.; Kurashov, Vitalij N.; Chyzh, Igor H.

1997-08-01

Many problems exist in ophthalmology, where accurate measurements of eye structure and its parameters can be provided using optical radar concept is of remote sensing. Coherent and non-coherent approaches are reviewed aiming cornea shape measurement and measurement of aberration distribution in the elements and media of an eye. Coherent radar techniques are analyzed taking into account non- reciprocity of eye media and anisoplanatism of the fovea, that results in an exiting image being not an auto- correlation of the point-spread function of a single pass, even in the approximation of spatial invariance of the system. It is found, that aberrations of the cornea and lens are not additive, and may not be brought to summary aberrations on the entrance aperture of the lens. Anisoplanatism of the fovea and its roughness lead to low degree of coherence in scattered light. To estimate the result of measurements, methodology has been developed using Zernike polynomials expansions. Aberration distributions were gotten from measurements in 16 points of an eye situated on two concentric circles. Wave aberration functions have been approximated using least-square criterion. Thus, all data were provided necessary for cornea ablation with PRK procedure.

Is ethnic prejudice declining in Britain? Change in social distance attitudes among ethnic majority and minority Britons.

PubMed

Storm, Ingrid; Sobolewska, Maria; Ford, Robert

2017-09-01

Most literature on racial prejudice deals with the racial attitudes of the ethnic majority and ethnic minorities separately. This paper breaks this tradition. We examine the social distance attitudes of white and non-white British residents to test if these attitudes follow the same trends over time, whether they are driven by the same social processes and whether they are inter-related. We have three main findings. Firstly, social distance from other ethnic groups has declined over time for both white and ethnic minority Britons. For the white majority there are both period and cohort elements to this decline. Secondly, we see some evidence that social distance between the majority and minority groups is reciprocal. Specifically, minorities who experience rejection by the white British feel a greater sense of distance from them. Thirdly, we find that all groups share the perception of the same ethnic hierarchy. We see evidence of particularly widespread hostility towards Muslim Britons from all ethnic groups suggesting that Muslims are singled out for negative attention from many British residents of all other backgrounds, including a large number who do not express hostility to other groups. © London School of Economics and Political Science 2017.

Radiation patterns of multimode feed-horn-coupled bolometers for FAR-IR space applications

NASA Astrophysics Data System (ADS)

Kalinauskaite, Eimante; Murphy, J. Anthony; McAuley, Ian; Trappe, Neal A.; McCarthy, Darragh N.; Bracken, Colm P.; Doherty, Stephen; Gradziel, Marcin L.; O'Sullivan, Créidhe; Wilson, Daniel; Peacocke, Tully; Maffei, Bruno; Lamarre, Jean-Michel; Ade, Peter A. R.; Savini, Giorgio

2017-02-01

A multimode horn differs from a single mode horn in that it has a larger sized waveguide feeding it. Multimode horns can therefore be utilized as high efficiency feeds for bolometric detectors, providing increased throughput and sensitivity over single mode feeds, while also ensuring good control of the beam pattern characteristics. Although a cavity mounted bolometer can be modelled as a perfect black body radiator (using reciprocity in order to calculate beam patterns), nevertheless, this is an approximation. In this paper we present how this approach can be improved to actually include the cavity coupled bolometer, now modelled as a thin absorbing film. Generally, this is a big challenge for finite element software, in that the structures are typically electrically large. However, the radiation pattern of multimode horns can be more efficiently simulated using mode matching, typically with smooth-walled waveguide modes as the basis and computing an overall scattering matrix for the horn-waveguide-cavity system. Another issue on the optical efficiency of the detectors is the presence of any free space gaps, through which power can escape. This is best dealt with treating the system as an absorber. Appropriate reflection and transmission matrices can be determined for the cavity using the natural eigenfields of the bolometer cavity system. We discuss how the approach can be applied to proposed terahertz systems, and also present results on how the approach was applied to improve beam pattern predictions on the sky for the multi-mode HFI 857GHz channel on Planck.

Cutting efficiency of Reciproc and waveOne reciprocating instruments.

PubMed

Plotino, Gianluca; Giansiracusa Rubini, Alessio; Grande, Nicola M; Testarelli, Luca; Gambarini, Gianluca

2014-08-01

The aim of the present study was to evaluate the cutting efficiency of 2 new reciprocating instruments, Reciproc and WaveOne. Twenty-four new Reciproc R25 and 24 new WaveOne Primary files were activated by using a torque-controlled motor (Silver Reciproc) and divided into 4 groups (n = 12): group 1, Reciproc activated by Reciproc ALL program; group 2, Reciproc activated by WaveOne ALL program; group 3, WaveOne activated by Reciproc ALL program; and group 4, WaveOne activated by WaveOne ALL program. The device used for the cutting test consisted of a main frame to which a mobile plastic support for the handpiece is connected and a stainless steel block containing a Plexiglas block (inPlexiglass, Rome, Italy) against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1 mm. Means and standard deviations of each group were calculated, and data were statistically analyzed with 1-way analysis of variance and Bonferroni test (P < .05). Reciproc R25 displayed greater cutting efficiency than WaveOne Primary for both the movements used (P < .05); in particular, Reciproc instruments used with their proper reciprocating motion presented a statistically significant higher cutting efficiency than WaveOne instruments used with their proper reciprocating motion (P < .05). There was no statistically significant difference between the 2 movements for both instruments (P > .05). Reciproc instruments demonstrated statistically higher cutting efficiency than WaveOne instruments. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Marmoset monkeys evaluate third-party reciprocity.

PubMed

Kawai, Nobuyuki; Yasue, Miyuki; Banno, Taku; Ichinohe, Noritaka

2014-05-01

Many non-human primates have been observed to reciprocate and to understand reciprocity in one-to-one social exchanges. A recent study demonstrated that capuchin monkeys are sensitive to both third-party reciprocity and violation of reciprocity; however, whether this sensitivity is a function of general intelligence, evidenced by their larger brain size relative to other primates, remains unclear. We hypothesized that highly pro-social primates, even with a relatively smaller brain, would be sensitive to others' reciprocity. Here, we show that common marmosets discriminated between human actors who reciprocated in social exchanges with others and those who did not. Monkeys accepted rewards less frequently from non-reciprocators than they did from reciprocators when the non-reciprocators had retained all food items, but they accepted rewards from both actors equally when they had observed reciprocal exchange between the actors. These results suggest that mechanisms to detect unfair reciprocity in third-party social exchanges do not require domain-general higher cognitive ability based on proportionally larger brains, but rather emerge from the cooperative and pro-social tendencies of species, and thereby suggest this ability evolved in multiple primate lineages. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Lunar single-scattering, porosity, and surface-roughness properties with SMART-1/AMIE

NASA Astrophysics Data System (ADS)

Parviainen, H.; Muinonen, K.; Näränen, J.; Josset, J.-L.; Beauvivre, S.; Pinet, P.; Chevrel, S.; Koschny, D.; Grieger, B.; Foing, B.

2009-04-01

We analyze the single-scattering albedo and phase function, local surface roughness and regolith porosity, and the coherent backscattering, single scattering, and shadowing contributions to the opposition effect for specific lunar mare regions imaged by the SMART-1/AMIE camera. We account for shadowing due to surface roughness and mutual shadowing among the regolith particles with ray-tracing computations for densely-packed particulate media with a fractional-Brownian-motion interface with free space. The shadowing modeling allows us to derive the hundred-micron-scale volume-element scattering phase function for the lunar mare regolith. We explain the volume-element phase function by a coherent-backscattering model, where the single scatterers are the submicron-to-micron-scale particle inhomogeneities and/or the smallest particles on the lunar surface. We express the single-scatterer phase function as a sum of three Henyey-Greenstein terms, accounting for increased backward scattering in both narrow and wide angular ranges. The Moon exhibits an opposition effect, that is, a nonlinear increase of disk-integrated brightness with decreasing solar phase angle, the angle between the Sun and the observer as seen from the object. Recently, the coherent-backscattering mechanism (CBM) has been introduced to explain the opposition effect. CBM is a multiple-scattering interference mechanism, where reciprocal waves propagating through the same scatterers in opposite directions always interfere constructively in the backward-scattering direction but with varying interference characteristics in other directions. In addition to CBM, mutual shadowing among regolith particles (SMp) and rough-surface shadowing (SMr) have their effect on the behavior of the observed lunar surface brightness. In order to accrue knowledge on the volume-element and, ultimately, single-scattering properties of the lunar regolith, both SMp and SMr need to be accurately accounted for. We included four different lunar mare regions in our study. Each of these regions covers several hundreds of square kilometers of lunar surface. When selecting the regions, we have required that they have been imaged by AMIE across a wide range of phase angles, including the opposition geometry. The phase-angle range covered is 0-109 °, with incidence and emergence angles (ι and ε) ranging within 7-87 ° and 0-53 °, respectively. The pixel scale varies from 288m down to 29m. Biases and dark currents were subtracted from the images in the usual way, followed by a flat-field correction. New dark-current reduction procedures have recently been derived from in-flight measurements to replace the ground-calibration images . The clear filter was chosen for the present study as it provides the largest field of view and is currently the best-calibrated channel. Off-nadir-pointing observations allowed for the extensive phase-angle coverage. In total, 220 images are used for the present study. The photometric data points were extracted as follows. First, on average, 50 sample areas of 10 Ã- 10 pixels were chosen by hand from each image. Second, the surface normal, ι, ε, °, and α were computed for each pixel in each sample area using the NASA/NAIF SPICE software toolkit with the latest and corrected SMART-1/AMIE SPICE kernels. Finally, the illumination angles and the observed intensity were averaged over each sample area. In total, the images used in the study resulted in approximately 11000 photometric sample points for the four mare regions. We make use of fractional-Brownian-motion surfaces in modeling the interface between free space and regolith and a size distribution of spherical particles in modeling the particulate medium. We extract the effects of the stochastic geometry from the lunar photometry and, simultaneously, obtain the volume-element scattering phase function of the lunar regolith locations studied. The volume-element phase function allows us to constrain the physical properties of the regolith particles. Based on the present theoretical modeling of the lunar photometry from SMART-1/AMIE, we conclude that most of the lunar mare opposition effect is caused by coherent backscattering and single scattering within volume elements comparable to lunar particle sizes, with only a small contribution from shadowing effects. We thus suggest that the lunar single scatterers exhibit intensity enhancement towards the backward scattering direction in resemblance to the scattering characteristics experimentally measured and theoretically computed for realistic small particles. Further interpretations of the lunar volume-element phase function will be the subject of future research.

Evidence of direct reciprocity, but not of indirect and generalized reciprocity, in the grooming exchanges of wild Barbary macaques (Macaca sylvanus).

PubMed

Molesti, Sandra; Majolo, Bonaventura

2017-09-01

Reciprocity is one of the mechanisms that have been proposed to explain the exchange of social behaviors, such as grooming, in animals. Reciprocity assumes that individuals act as the donor and recipient of grooming and switch roles over time to balance the benefits and costs of this behavior. Three main patterns of reciprocity may follow a grooming given: (i) direct reciprocity, where the former recipient returns the grooming to the former donor; (ii) indirect reciprocity, where another individual returns the grooming to the former donor; and (iii) generalized reciprocity, where the former recipient returns the grooming to another individual. While there is evidence that direct reciprocity plays an important role in various species of animals, the role of indirect and generalized reciprocity is less clear and has been rarely analyzed. We tested the role of direct, indirect, and generalized reciprocity in explaining grooming exchanges of wild Barbary macaques, by analyzing the temporal contingency between giving and receiving grooming. We collected the occurrence and latency of the three types of grooming reciprocation during 1 hr long focal sessions run simultaneously on two partners who just stopped grooming (post-grooming session) or who were in proximity (i.e., within 1.5 m) without grooming each other (control session). We ran the analyses on 284 post-grooming and 63 control sessions. The results revealed a temporal contingency of grooming interactions exchanged according to direct reciprocity but not according to indirect or generalized reciprocity. Our results indicate that grooming distribution in Barbary macaques is partner-specific. We discuss the possible role of cognition and emotions in explaining direct reciprocity in animals. © 2017 Wiley Periodicals, Inc.

Chaos, oscillation and the evolution of indirect reciprocity in n-person games.

PubMed

Suzuki, Shinsuke; Akiyama, Eizo

2008-06-21

Evolution of cooperation among genetically unrelated individuals has been of considerable concern in various fields such as biology, economics, and psychology. The evolution of cooperation is often explained by reciprocity. Under reciprocity, cooperation can prevail in a society because a donor of cooperation receives reciprocation from the recipient of the cooperation, called direct reciprocity, or from someone else in the community, called indirect reciprocity. Nowak and Sigmund [1993. Chaos and the evolution of cooperation. Proc. Natl. Acad. Sci. USA 90, 5091-5094] have demonstrated that directly reciprocal cooperation in two-person prisoner's dilemma games with mutation of strategies can be maintained dynamically as periodic or chaotic oscillation. Furthermore, Eriksson and Lindgren [2005. Cooperation driven by mutations in multi-person Prisoner's Dilemma. J. Theor. Biol. 232, 399-409] have reported that directly reciprocal cooperation in n-person prisoner's dilemma games (n>2) can be maintained as periodic oscillation. Is dynamic cooperation observed only in direct reciprocity? Results of this study show that indirectly reciprocal cooperation in n-person prisoner's dilemma games can be maintained dynamically as periodic or chaotic oscillation. This is, to our knowledge, the first demonstration of chaos in indirect reciprocity. Furthermore, the results show that oscillatory dynamics are observed in common in the evolution of reciprocal cooperation whether for direct or indirect.

Interface Evaluation for Open System Architectures

DTIC Science & Technology

2014-03-01

maker (SDM) is responsible for balancing all of the influences of the IPT when making decisions. Coalescing the IPT perspectives for a single IIM...factors are considered in IIM decisions and that decisions are consistent with the preferences of the SDM, ultimately leading to a balance of schedule... board to perform ranking and weighting determinations. Rank sum, rank exponent, rank reciprocal and ROC leverage a subjective assessment of the

Strong spectral variation of biomass smoke light absorption and single scattering albedo observed with a novel dual-wavelength photoacoustic instrument

Treesearch

Kristin Lewis; William P. Arnott; Hans Moosmuller; Cyle E. Wold

2008-01-01

A dual-wavelength photoacoustic instrument operating at 405 and 870 nm was used during the 2006 Fire Lab at Missoula Experiment to measure light scattering and absorption by smoke from the combustion of a variety of biomass fuels. Simultaneous measurements of aerosol light scattering by reciprocal nephelometry within the instrument's acoustic resonator accompany...

Empowering low-income black families of handicapped children.

PubMed

Kalyanpur, M; Rao, S S

1991-10-01

A qualitative study of four black, low-income, single mothers used in-depth interviews and participant observation to evaluate their interactions with outreach agency professionals. Three perceived aspects (disrespect, focus on deficits, and discounting parenting style differences) were associated with exclusionary (unempowering) relationships. A reciprocal and supportive approach was associated with collaborative (empowering) relationships. Implications of these findings for professionals serving minority families are discussed.

Global Health Opportunities in Obstetrics and Gynecology Training: Examining Engagement through an Ethical Lens

PubMed Central

Zaidi, Mohammad Y.; Haddad, Lisa; Lathrop, Eva

2015-01-01

This study aims to describe global health training (GHT) programs through the ethical lens suggested by the Working Group on Ethics Guidelines for Global Health Training (WEIGHT). A total of 35 GHT programs were identified, and general information was obtained online. Semi-structured telephone interviews of key members of 19 programs were then conducted and transcribed. The interview guide was constructed using WEIGHT recommendations. Transcript data were grouped according to domains: reciprocity, trainee selection and preparedness, needs assessments, and ethical questions. Many programs expressed difficulty in building reciprocal relationships due to imbalanced power structures. Eleven programs reported no formal application process for selecting trainees. Twelve (63%) programs reported only a single day of preparation. Nine (47%) programs did not conduct a formalized needs assessment of partner sites. Ethical considerations varied from concerns for safety to inadequate training for residents. This study reveals the limited preparedness curricula and lack of formalized needs assessments among several programs. Although many programs make an effort to build reciprocal exchanges with host partners, experiences for foreign trainees within the United States are limited, and U.S. residents are often tasked with duties above their training level abroad. This study demonstrates the need to restructure how GHT programs are formed and operated. PMID:26324736

Longitudinal and Reciprocal Relationships Between Depression and Disability in Older Women Caregivers and Noncaregivers

PubMed Central

Bacon, Kathryn L.; Heeren, Timothy; Keysor, Julie J.; Stuver, Sherri O.; Cauley, Jane A.; Fredman, Lisa

2016-01-01

Purpose of the Study: Depressive symptoms and disability each increase the risk of the other, yet few studies have examined reciprocal associations between these conditions in a single study, or over periods longer than 3 years. These associations may differ in older caregivers due to chronic stress, health characteristics, or factors related to caregiving. Design and Methods: Structural equation models were used to investigate relationships between depressive symptoms and disability over 3 interviews spanning 6 years among 956 older women (M = 81.5 years) from the Caregiver Study of Osteoporotic Fractures. Results were evaluated separately for 611 noncaregivers and 345 caregivers to a relative or friend. Results: In noncaregivers, more depressive symptoms significantly predicted greater disability, whereas greater disability predicted increased depressive symptoms at the next interview in age-adjusted models. In contrast, there was not a significant relationship between depression and disability in either direction for caregivers. Further adjustment for body mass index and medical condition variables did not change these relationships. Implications: Caregivers did not exhibit longitudinal or reciprocal relationships between depressive symptoms and disability observed in noncaregivers. It is possible that older women caregivers are buffered by better physical condition or social interactions related to caregiving activities. PMID:26035874

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

Carpentier, J.L.; Di Bono, P.J.; Tournebise, P.J.

The efficient bounding method for DC contingency analysis is improved using reciprocity properties. Knowing the consequences of the outage of a branch, these properties provide the consequences on that branch of various kinds of outages. This is used in order to reduce computation times and to get rid of some difficulties, such as those occurring when a branch flow is close to its limit before outage. Compensation, sparse vector, sparse inverse and bounding techniques are also used. A program has been implemented for single branch outages and tested on actual French EHV 650 bus network. Computation times are 60% ofmore » the Efficient Bounding method. The relevant algorithm is described in detail in the first part of this paper. In the second part, reciprocity properties and bounding formulas are extended for multiple branch outages and for multiple generator or load outages. An algorithm is proposed in order to handle all these cases simultaneously.« less

10. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model No. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. To the left of the horizontal (fluted) cylinder is the water pump which moved the boiler feed water through the engine's pre-heat system (the exhaust steam heated the boiler feedwater before it was pumped on to the boiler). The steam-feed port, manual throttle valve, and fly-ball governor and pulley and to the right of the cylinder. The drive shaft with flywheel to the left and pulley to the right are seen behind the piston rod, cross-head, wrist pen, connecting rod and the slide valve and eccentric. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Nick-free formation of reciprocal heteroduplexes: a simple solution to the topological problem.

PubMed Central

Wilson, J H

1979-01-01

Because the individual strands of DNA are intertwined, formation of heteroduplex structures between duplexes--as in presumed recombination intermediates--presents a topological puzzle, known as the winding problem. Previous approaches to this problem have assumed that single-strand breaks are required to permit formation of fully coiled heteroduplexes. This paper describes a simple, nick-free solution to the winding problem that satisfies all topological constraints. Homologous duplexes associated by their minor-groove surfaces can switch strand pairing to form reciprocal heteroduplexes that coil together into a compact, four-stranded helix throughout the region of pairing. Model building shows that this fused heteroduplex structure is plausible, being composed entirely of right-handed primary helices with Watson-Crick base pairing throughout. Its simplicity of formation, structural symmetry, and high degree of specificity are suggestive of a natural mechanism for alignment by base pairing between intact homologous duplexes. Implications for genetic recombination are discussed. Images PMID:291028

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

Tropp, James

We give formulas for transduction in magnetic resonance - i.e., the appearance of an emf due to Larmor precession of spins - based upon the modified Lorentz reciprocity principle for gyrotropic (also called 'nonreciprocal') media, i.e., in which a susceptibility tensor is carried to its transpose by reversal of an external static field [cf., R. F. Harrington and A. T. Villeneuve IRE Trans. Microwave Theory and Technique MTT6, 308 (1958)]. Prior applications of reciprocity to magnetic resonance, despite much success, have ignored the gyrotropism which necessarily arises due to nuclear and/or unpaired electronic spins. For detection with linearly polarized fields,more » oscillating at the Larmor frequency, the emf is written in terms of a volume integral containing a product of two factors which we define as the antenna patterns, i.e. (H{sub 1x}{+-}iH{sub 1y}), where, e.g., for a single transceive antenna, the H's are just the spatially dependent oscillatory magnetic field strengths, per the application of some reference current at the antenna terminals, with the negative sign obtaining for transmission, and the positive for reception. Similar expressions hold for separate transmit and receive antennas; expressions are also given for circular polarization of the fields. We then exhibit a receive-only array antenna of two elements for magnetic resonance imaging of protons, which, due an intensity artifact arising from stray reactive coupling of the elements, produces, despite its own bilateral symmetry, asymmetric proton NMR images of a symmetric cylindrical phantom containing aqueous saline solution [J. Tropp and T. Schirmer, J. Magn. Reson. 151, 146 (2001)]. Modification of this two-port antenna, to function in transmit-receive mode, allows us to demonstrate highly nonreciprocal behavior: that is, to record images (of cylindrical test phantoms containing aqueous saline solution) whose appearance dramatically changes, when the roles of transmission and reception are swapped between the two antenna ports--giving in one instance a signal intensity pattern whose form resembles an umbrella (i.e., with a central column of moderate intensity surmounted by a bright canopy), and in the other, a distorted oval with slight concavities at its horizontal extremes, whose outline suggests that of a cat's eye. The relation between image patterns and drive scheme can be shown to reverse if the static polarizing field is reversed. Electromagnetic and circuit calculations, together with the modified reciprocity principle, allow us to reproduce these pattern changes in numerical simulations, closely and convincingly. Although the imaging experiments are performed at a static field of 3.0 T, and consequently a Larmor frequency of 128 MHz, the nonreciprocal effects are not related to the shortness of the wavelength in aqueous medium, but appear equally in simulations based in either the quasistatic or full electromagnetic regimes. Finally, we show that although antenna patterns for transmission and reception are swapped with reversal of the polarizing field, meaning that the receive pattern equals the transmit pattern with the field reversed, this in no way invalidates the familiar rotating wave model of spin dynamics in magnetic resonance.« less

30 CFR 57.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors rated...

30 CFR 57.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors rated...

Reciprocity of weighted networks

PubMed Central

Squartini, Tiziano; Picciolo, Francesco; Ruzzenenti, Franco; Garlaschelli, Diego

2013-01-01

In directed networks, reciprocal links have dramatic effects on dynamical processes, network growth, and higher-order structures such as motifs and communities. While the reciprocity of binary networks has been extensively studied, that of weighted networks is still poorly understood, implying an ever-increasing gap between the availability of weighted network data and our understanding of their dyadic properties. Here we introduce a general approach to the reciprocity of weighted networks, and define quantities and null models that consistently capture empirical reciprocity patterns at different structural levels. We show that, counter-intuitively, previous reciprocity measures based on the similarity of mutual weights are uninformative. By contrast, our measures allow to consistently classify different weighted networks according to their reciprocity, track the evolution of a network's reciprocity over time, identify patterns at the level of dyads and vertices, and distinguish the effects of flux (im)balances or other (a)symmetries from a true tendency towards (anti-)reciprocation. PMID:24056721

Reciprocity of weighted networks.

PubMed

Squartini, Tiziano; Picciolo, Francesco; Ruzzenenti, Franco; Garlaschelli, Diego

2013-01-01

In directed networks, reciprocal links have dramatic effects on dynamical processes, network growth, and higher-order structures such as motifs and communities. While the reciprocity of binary networks has been extensively studied, that of weighted networks is still poorly understood, implying an ever-increasing gap between the availability of weighted network data and our understanding of their dyadic properties. Here we introduce a general approach to the reciprocity of weighted networks, and define quantities and null models that consistently capture empirical reciprocity patterns at different structural levels. We show that, counter-intuitively, previous reciprocity measures based on the similarity of mutual weights are uninformative. By contrast, our measures allow to consistently classify different weighted networks according to their reciprocity, track the evolution of a network's reciprocity over time, identify patterns at the level of dyads and vertices, and distinguish the effects of flux (im)balances or other (a)symmetries from a true tendency towards (anti-)reciprocation.

Toward a Behavior of Reciprocity.

PubMed

Gernsbacher, Morton Ann

It is frequently believed that autism is characterized by a lack of social or emotional reciprocity. In this article, I question that assumption by demonstrating how many professionals-researchers and clinicians-and likewise many parents, have neglected the true meaning of reciprocity. Reciprocity is "a relation of mutual dependence or action or influence," or "a mode of exchange in which transactions take place between individuals who are symmetrically placed." Assumptions by clinicians and researchers suggest that they have forgotten that reciprocity needs to be mutual and symmetrical-that reciprocity is a two-way street. Research is reviewed to illustrate that when professionals, peers, and parents are taught to act reciprocally, autistic children become more responsive. In one randomized clinical trial of "reciprocity training" to parents, their autistic children's language developed rapidly and their social engagement increased markedly. Other demonstrations of how parents and professionals can increase their behavior of reciprocity are provided.

High-compactness coating grown by plasma electrolytic oxidation on AZ31 magnesium alloy in the solution of silicate-borax

NASA Astrophysics Data System (ADS)

Shen, M. J.; Wang, X. J.; Zhang, M. F.

2012-10-01

A ceramic coating was formed on the surface of AZ31 magnesium alloy by plasma electrolytic oxidation (PEO) in the silicate solution with and without borax doped. The composition, morphology, elements and roughness as well as mechanical property of the coating were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and reciprocal-sliding tribometer. The results show that the PEO coating is mainly composed of magnesia. When using borax dope, boron element is permeating into the coating and the boron containing phase exist in the form of amorphous. In addition, the microhardness and compactness of the PEO coating are improved significantly due to doped borax.

Elements of patient-health-care provider communication related to cardiovascular rehabilitation referral.

PubMed

Pourhabib, Sanam; Chessex, Caroline; Murray, Judy; Grace, Sherry L

2016-04-01

Cardiovascular rehabilitation has been designed to decrease the burden of cardiovascular disease. This study described (1) patient-health-care provider interactions regarding cardiovascular rehabilitation and (2) which discussion elements were related to patient referral. This was a prospective study of cardiovascular patients and their health-care providers. Discussion utterances were coded using the Roter Interaction Analysis System. Discussion between 26 health-care providers and 50 patients were recorded. Cardiovascular rehabilitation referral was related to greater health-care provider interactivity (odds ratio = 2.82, 95% confidence interval = 1.01-7.86) and less patient concern and worry (odds ratio = 0.64, 95% confidence interval = 0.45-0.89). Taking time for reciprocal discussion and allaying patient anxiety may promote greater referral. © The Author(s) 2014.

32 CFR 148.1 - Intergency reciprocal acceptance .

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND CIVILIAN NATIONAL POLICY AND IMPLEMENTATION OF RECIPROCITY OF FACILITIES National Policy on Reciprocity of Use and Inspections of Facilities § 148.1 Intergency reciprocal acceptance . Interagency...

32 CFR 148.1 - Intergency reciprocal acceptance .

Code of Federal Regulations, 2011 CFR

2011-07-01

... AND CIVILIAN NATIONAL POLICY AND IMPLEMENTATION OF RECIPROCITY OF FACILITIES National Policy on Reciprocity of Use and Inspections of Facilities § 148.1 Intergency reciprocal acceptance . Interagency...

Alternative approximation concepts for space frame synthesis

NASA Technical Reports Server (NTRS)

Lust, R. V.; Schmit, L. A.

1985-01-01

A structural synthesis methodology for the minimum mass design of 3-dimensionall frame-truss structures under multiple static loading conditions and subject to limits on displacements, rotations, stresses, local buckling, and element cross-sectional dimensions is presented. A variety of approximation concept options are employed to yield near optimum designs after no more than 10 structural analyses. Available options include: (A) formulation of the nonlinear mathematcal programming problem in either reciprocal section property (RSP) or cross-sectional dimension (CSD) space; (B) two alternative approximate problem structures in each design space; and (C) three distinct assumptions about element end-force variations. Fixed element, design element linking, and temporary constraint deletion features are also included. The solution of each approximate problem, in either its primal or dual form, is obtained using CONMIN, a feasible directions program. The frame-truss synthesis methodology is implemented in the COMPASS computer program and is used to solve a variety of problems. These problems were chosen so that, in addition to exercising the various approximation concepts options, the results could be compared with previously published work.

32 CFR 148.1 - Interagency reciprocal acceptance .

Code of Federal Regulations, 2014 CFR

2014-07-01

..., MILITARY AND CIVILIAN NATIONAL POLICY AND IMPLEMENTATION OF RECIPROCITY OF FACILITIES National Policy on Reciprocity of Use and Inspections of Facilities § 148.1 Interagency reciprocal acceptance . Interagency...

32 CFR 148.1 - Interagency reciprocal acceptance .

Code of Federal Regulations, 2012 CFR

2012-07-01

..., MILITARY AND CIVILIAN NATIONAL POLICY AND IMPLEMENTATION OF RECIPROCITY OF FACILITIES National Policy on Reciprocity of Use and Inspections of Facilities § 148.1 Interagency reciprocal acceptance . Interagency...

32 CFR 148.1 - Interagency reciprocal acceptance .

Code of Federal Regulations, 2013 CFR

2013-07-01

..., MILITARY AND CIVILIAN NATIONAL POLICY AND IMPLEMENTATION OF RECIPROCITY OF FACILITIES National Policy on Reciprocity of Use and Inspections of Facilities § 148.1 Interagency reciprocal acceptance . Interagency...

Direct reciprocity in spatial populations enhances R-reciprocity as well as ST-reciprocity.

PubMed

Miyaji, Kohei; Tanimoto, Jun; Wang, Zhen; Hagishima, Aya; Ikegaya, Naoki

2013-01-01

As is well-known, spatial reciprocity plays an important role in facilitating the emergence of cooperative traits, and the effect of direct reciprocity is also obvious for explaining the cooperation dynamics. However, how the combination of these two scenarios influences cooperation is still unclear. In the present work, we study the evolution of cooperation in 2 × 2 games via considering both spatial structured populations and direct reciprocity driven by the strategy with 1-memory length. Our results show that cooperation can be significantly facilitated on the whole parameter plane. For prisoner's dilemma game, cooperation dominates the system even at strong dilemma, where maximal social payoff is still realized. In this sense, R-reciprocity forms and it is robust to the extremely strong dilemma. Interestingly, when turning to chicken game, we find that ST-reciprocity is also guaranteed, through which social average payoff and cooperation is greatly enhanced. This reciprocity mechanism is supported by mean-field analysis and different interaction topologies. Thus, our study indicates that direct reciprocity in structured populations can be regarded as a more powerful factor for the sustainability of cooperation.

Institutionalize Reciprocity to Overcome the Public Goods Provision Problem

PubMed Central

2016-01-01

Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner’s dilemma (PD) experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG) games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR), which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy). We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system. PMID:27248493

Nonlinear Time-Reversal in a Wave Chaotic System

NASA Astrophysics Data System (ADS)

Frazier, Matthew; Taddese, Biniyam; Ott, Edward; Antonsen, Thomas; Anlage, Steven

2012-02-01

Time reversal mirrors are particularly simple to implement in wave chaotic systems and form the basis for a new class of sensors [1-3]. These sensors work by applying the quantum mechanical concepts of Loschmidt echo and fidelity decay to classical waves. The sensors make explicit use of time-reversal invariance and spatial reciprocity in a wave chaotic system to remotely measure the presence of small perturbations to the system. The underlying ray chaos increases the sensitivity to small perturbations throughout the volume explored by the waves. We extend our time-reversal mirror to include a discrete element with a nonlinear dynamical response. The initially injected pulse interacts with the nonlinear element, generating new frequency components originating at the element. By selectively filtering for and applying the time-reversal mirror to the new frequency components, we focus a pulse only onto the element, without knowledge of its location. Furthermore, we demonstrate transmission of arbitrary patterns of pulses to the element, creating a targeted communication channel to the exclusion of 'eavesdroppers' at other locations in the system. [1] Appl. Phys. Lett. 95, 114103 (2009) [2] J. Appl. Phys. 108, 1 (2010) [3] Acta Physica Polonica A 112, 569 (2007)

Modeling of Structural-Acoustic Interaction Using Coupled FE/BE Method and Control of Interior Acoustic Pressure Using Piezoelectric Actuators

NASA Technical Reports Server (NTRS)

Mei, Chuh; Shi, Yacheng

1997-01-01

A coupled finite element (FE) and boundary element (BE) approach is presented to model full coupled structural/acoustic/piezoelectric systems. The dual reciprocity boundary element method is used so that the natural frequencies and mode shapes of the coupled system can be obtained, and to extend this approach to time dependent problems. The boundary element method is applied to interior acoustic domains, and the results are very accurate when compared with limited exact solutions. Structural-acoustic problems are then analyzed with the coupled finite element/boundary element method, where the finite element method models the structural domain and the boundary element method models the acoustic domain. Results for a system consisting of an isotropic panel and a cubic cavity are in good agreement with exact solutions and experiment data. The response of a composite panel backed cavity is then obtained. The results show that the mass and stiffness of piezoelectric layers have to be considered. The coupled finite element and boundary element equations are transformed into modal coordinates, which is more convenient for transient excitation. Several transient problems are solved based on this formulation. Two control designs, a linear quadratic regulator (LQR) and a feedforward controller, are applied to reduce the acoustic pressure inside the cavity based on the equations in modal coordinates. The results indicate that both controllers can reduce the interior acoustic pressure and the plate deflection.

Postoperative Pain after Endodontic Retreatment Using Rotary or Reciprocating Instruments: A Randomized Clinical Trial.

PubMed

Comparin, Daniel; Moreira, Edson Jorge Lima; Souza, Erick M; De-Deus, Gustavo; Arias, Ana; Silva, Emmanuel João Nogueira Leal

2017-07-01

The aim of this randomized clinical trial was to evaluate the influence of rotary or reciprocating retreatment techniques on the incidence, intensity, duration of postoperative pain, and medication intake. After power analysis calculations, 65 patients who needed endodontic retreatment were randomly assigned to 1 of 2 groups according to the instrumentation system used: Mtwo (VDW, Munich, Germany) or Reciproc (VDW). Retreatments were performed in a single visit by an endodontic specialist. Participants were asked to rate the incidence and intensity of the postoperative pain on a verbal rating scale 24, 48, and 72 hours after treatment. Patients were also asked to record the number of prescribed analgesic medication tablets (ibuprofen 400 mg) taken. A logistic regression analysis was used to assess both the incidence and duration of pain. Differences in the intensity of pain were analyzed using the ordinal (linear) chi-square test, and the Mann-Whitney U test was used to assess differences in the intake of analgesic medication between groups. No statistically significant difference was found among the 2 groups in relation to postoperative pain or analgesic medication intake at the 3 time points assessed (P > .05). Multivariate analysis showed a significantly higher incidence of pain after 24 hours when preoperative pain was present and a significantly longer duration of pain for men than women independently of the retreatment technique used. The reciprocating system and the continuous rotary system were found to be equivalent regarding the incidence, intensity, duration of postoperative pain, and intake of analgesic medication. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

NSK reciprocating handpiece: in vitro comparative analysis of dentinal removal during root canal preparation by different operators.

PubMed

Wagner, Márcia Helena; Barletta, Fernando Branco; Reis, Magda de Souza; Mello, Luciano Loureiro; Ferreira, Ronise; Fernandes, Antônio Luiz Rocha

2006-01-01

The purpose of this study was to assess dentin removal during root canal preparation by different operators using a NSK reciprocating handpiece. Eighty-four human single-rooted mandibular premolars were hand instrumented using Triple-Flex stainless-steel files (Kerr) up to #30, weighed in analytical balance and randomly assigned to 4 groups (n=21). All specimens were mechanically prepared at the working length with #35 to #45 Triple-Flex files (Kerr) coupled to a NSK (TEP-E10R, Nakanishi Inc.) reciprocating handpiece powered by an electric motor (Endo Plus; VK Driller). Groups 1 to 4 were prepared by a professor of Endodontics, an endodontist, a third-year dental student and a general dentist, respectively. Teeth were reweighed after root canal preparation. The difference between weights was calculated and the means of dentin removal in each group were analyzed statistically by ANOVA and Tukey's test at 5 % significance level. The greatest amount of dentin removal was found in group 4, followed by groups 2, 3 and 1. Group 4 differed statistically from the other groups regarding dentin removal means [p<0.001 (group 1); p=0.005 (group 2); and p=0.001 (group 3)]. No statistically significant difference was found between groups 1 and 2 (p=0.608), 1 and 3 (p=0.914) and 2 and 3 (p=0.938). In conclusion, although the group prepared by a general dentist differed statistically from the other groups in terms of amount of dentin removal, this difference was clinically irrelevant. The NSK reciprocating handpiece powered by an electric engine was proved an effective auxiliary tool in root canal preparation, regardless of the operator's skills.

Payoff non-linearity sways the effect of mistakes on the evolution of reciprocity.

PubMed

Kurokawa, Shun

2016-09-01

The existence of cooperation is considered to require explanation, and reciprocity is a potential explanatory mechanism. Animals sometimes fail to cooperate even when they attempt to do so, and a reciprocator has an Achilles' heel: it is vulnerable to error (the interaction between two reciprocators can lead to an endless vendetta.). However, the strategy favored by natural selection is determined also by its interaction with other strategies. The relationship between two reciprocators leading to a collapse of cooperation through error does not straightforwardly imply that mistakes make the conditions under which reciprocity evolves stringent. Hence, mistakes may facilitate the evolution of reciprocity. However, it has been shown through the analysis of the interaction between reciprocators and unconditional defectors that the existence of mistakes makes the conditions for reciprocators stable against invasion by an unconditional defector more stringent, which indicates that mistakes discourage the evolution of reciprocity. However, this result is based on the assumption that the effects of cooperation are additive (payoff is linear), while the game played by real animals does not always display this feature. In such cases, the result may be swayed. In this paper, we remove this assumption, reexamining whether mistakes disturb the evolution of reciprocity. Using the analysis of an evolutionarily stable strategy (ESS), we show that when extra fitness costs are present in cases where mutual cooperation is established, mistakes can facilitate the evolution of reciprocity; whereas, when the effect of cooperation is additive, mistakes always disturb the evolution of reciprocity, as has been shown previously. Copyright © 2016. Published by Elsevier Inc.

Simulations of X-ray diffraction of shock-compressed single-crystal tantalum with synchrotron undulator sources.

PubMed

Tang, M X; Zhang, Y Y; E, J C; Luo, S N

2018-05-01

Polychromatic synchrotron undulator X-ray sources are useful for ultrafast single-crystal diffraction under shock compression. Here, simulations of X-ray diffraction of shock-compressed single-crystal tantalum with realistic undulator sources are reported, based on large-scale molecular dynamics simulations. Purely elastic deformation, elastic-plastic two-wave structure, and severe plastic deformation under different impact velocities are explored, as well as an edge release case. Transmission-mode diffraction simulations consider crystallographic orientation, loading direction, incident beam direction, X-ray spectrum bandwidth and realistic detector size. Diffraction patterns and reciprocal space nodes are obtained from atomic configurations for different loading (elastic and plastic) and detection conditions, and interpretation of the diffraction patterns is discussed.

Simulations of X-ray diffraction of shock-compressed single-crystal tantalum with synchrotron undulator sources

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

Tang, M. X.; Zhang, Y. Y.; E, J. C.

Polychromatic synchrotron undulator X-ray sources are useful for ultrafast single-crystal diffraction under shock compression. Here, simulations of X-ray diffraction of shock-compressed single-crystal tantalum with realistic undulator sources are reported, based on large-scale molecular dynamics simulations. Purely elastic deformation, elastic–plastic two-wave structure, and severe plastic deformation under different impact velocities are explored, as well as an edge release case. Transmission-mode diffraction simulations consider crystallographic orientation, loading direction, incident beam direction, X-ray spectrum bandwidth and realistic detector size. Diffraction patterns and reciprocal space nodes are obtained from atomic configurations for different loading (elastic and plastic) and detection conditions, and interpretation of themore » diffraction patterns is discussed.« less

Transient nature of cooperation by pay-it-forward reciprocity

PubMed Central

Horita, Yutaka; Takezawa, Masanori; Kinjo, Takuji; Nakawake, Yo; Masuda, Naoki

2016-01-01

Humans often forward kindness received from others to strangers, a phenomenon called the upstream or pay-it-forward indirect reciprocity. Some field observations and laboratory experiments found evidence of pay-it-forward reciprocity in which chains of cooperative acts persist in social dilemma situations. Theoretically, however, cooperation based on pay-it-forward reciprocity is not sustainable. We carried out laboratory experiments of a pay-it-forward indirect reciprocity game (i.e., chained gift-giving game) on a large scale in terms of group size and time. We found that cooperation consistent with pay-it-forward reciprocity occurred only in a first few decisions per participant and that cooperation originated from inherent pro-sociality of individuals. In contrast, the same groups of participants showed persisting chains of cooperation in a different indirect reciprocity game in which participants earned reputation by cooperating. Our experimental results suggest that pay-it-forward reciprocity is transient and disappears when a person makes decisions repeatedly, whereas the reputation-based reciprocity is stable in the same situation. PMID:26786178

Competition among cooperators: Altruism and reciprocity

PubMed Central

Danielson, Peter

2002-01-01

Levine argues that neither self-interest nor altruism explains experimental results in bargaining and public goods games. Subjects' preferences appear also to be sensitive to their opponents' perceived altruism. Sethi and Somanathan provide a general account of reciprocal preferences that survive under evolutionary pressure. Although a wide variety of reciprocal strategies pass this evolutionary test, Sethi and Somanthan conjecture that fewer are likely to survive when reciprocal strategies compete with each other. This paper develops evolutionary agent-based models to test their conjecture in cases where reciprocal preferences can differ in a variety of games. We confirm that reciprocity is necessary but not sufficient for optimal cooperation. We explore the theme of competition among reciprocal cooperators and display three interesting emergent organizations: racing to the “moral high ground,” unstable cycles of preference change, and, when we implement reciprocal mechanisms, hierarchies resulting from exploiting fellow cooperators. If reciprocity is a basic mechanism facilitating cooperation, we can expect interaction that evolves around it to be complex, non-optimal, and resistant to change. PMID:12011403

Transient nature of cooperation by pay-it-forward reciprocity.

PubMed

Horita, Yutaka; Takezawa, Masanori; Kinjo, Takuji; Nakawake, Yo; Masuda, Naoki

2016-01-20

Humans often forward kindness received from others to strangers, a phenomenon called the upstream or pay-it-forward indirect reciprocity. Some field observations and laboratory experiments found evidence of pay-it-forward reciprocity in which chains of cooperative acts persist in social dilemma situations. Theoretically, however, cooperation based on pay-it-forward reciprocity is not sustainable. We carried out laboratory experiments of a pay-it-forward indirect reciprocity game (i.e., chained gift-giving game) on a large scale in terms of group size and time. We found that cooperation consistent with pay-it-forward reciprocity occurred only in a first few decisions per participant and that cooperation originated from inherent pro-sociality of individuals. In contrast, the same groups of participants showed persisting chains of cooperation in a different indirect reciprocity game in which participants earned reputation by cooperating. Our experimental results suggest that pay-it-forward reciprocity is transient and disappears when a person makes decisions repeatedly, whereas the reputation-based reciprocity is stable in the same situation.

Automated fuel pin loading system

DOEpatents

Christiansen, David W.; Brown, William F.; Steffen, Jim M.

1985-01-01

An automated loading system for nuclear reactor fuel elements utilizes a gravity feed conveyor which permits individual fuel pins to roll along a constrained path perpendicular to their respective lengths. The individual lengths of fuel cladding are directed onto movable transports, where they are aligned coaxially with the axes of associated handling equipment at appropriate production stations. Each fuel pin can be reciprocated axially and/or rotated about its axis as required during handling steps. The fuel pins are inserted as a batch prior to welding of end caps by one of two disclosed welding systems.

Automated fuel pin loading system

DOEpatents

Christiansen, D.W.; Brown, W.F.; Steffen, J.M.

An automated loading system for nuclear reactor fuel elements utilizes a gravity feed conveyor which permits individual fuel pins to roll along a constrained path perpendicular to their respective lengths. The individual lengths of fuel cladding are directed onto movable transports, where they are aligned coaxially with the axes of associated handling equipment at appropriate production stations. Each fuel pin can be be reciprocated axially and/or rotated about its axis as required during handling steps. The fuel pins are inerted as a batch prior to welding of end caps by one of two disclosed welding systems.

Supplementary Material for Finding the Stable Structures of N1-xWX with an Ab-initio High-Throughput Approach

DTIC Science & Technology

2015-05-08

around errors ENMAX=560 # 1.4*ENMAX (400) of pseudopotentials LREAL=.FALSE. # reciprocal space projection technique EDIFF=1E-6 # high accuracy...required ALGO=Fast # ALGO = Fast SYMPREC=1e-7 # Precise Symmetry ISPIN=1 # SPIN=OFF ISMEAR=-1 # Fermi broadening SIGMA =0.0272 # About 0.002 Ry The vdW-DF29...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S

Revisiting "The evolution of reciprocity in sizable groups": continuous reciprocity in the repeated n-person prisoner's dilemma.

PubMed

Takezawa, Masanori; Price, Michael E

2010-05-21

For many years in evolutionary science, the consensus view has been that while reciprocal altruism can evolve in dyadic interactions, it is unlikely to evolve in sizable groups. This view had been based on studies which have assumed cooperation to be discrete rather than continuous (i.e., individuals can either fully cooperate or else fully defect, but they cannot continuously vary their level of cooperation). In real world cooperation, however, cooperation is often continuous. In this paper, we re-examine the evolution of reciprocity in sizable groups by presenting a model of the n-person prisoner's dilemma that assumes continuous rather than discrete cooperation. This model shows that continuous reciprocity has a dramatically wider basin of attraction than discrete reciprocity, and that this basin's size increases with efficiency of cooperation (marginal per capita return). Further, we find that assortative interaction interacts synergistically with continuous reciprocity to a much greater extent than it does with discrete reciprocity. These results suggest that previous models may have underestimated reciprocity's adaptiveness in groups. However, we also find that the invasion of continuous reciprocators into a population of unconditional defectors becomes realistic only within a narrow parameter space in which the efficiency of cooperation is close to its maximum bound. Therefore our model suggests that continuous reciprocity can evolve in large groups more easily than discrete reciprocity only under unusual circumstances. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Femtosecond laser-induced structural difference in fused silica with a non-reciprocal writing process

NASA Astrophysics Data System (ADS)

Song, Hui; Dai, Ye; Song, Juan; Ma, Hongliang; Yan, Xiaona; Ma, Guohong

2017-04-01

In this paper, we report a non-reciprocal writing process for inducing asymmetric microstructure using a femtosecond laser with tilted pulse fronts in fused silica. The shape of the induced microstructure at the focus closely depends on the laser scan direction. An elongated end is observed as a kind of structural difference between the written lines with two reverse scans along + x and - x, which further leads to a birefringence intensity difference. We also find a bifurcation in the head region of the induced microstructure between the written lines along x and y. That process results from the focal intensity distortion caused by the pulse front tilt by comparing the simulated intensity distribution with the experimental results. The current results demonstrate that the pulse front tilt not only affects the free electron excitation at the focus but also further distorts the shape of the induced microstructure during a high-energy femtosecond laser irradiation. These results offer a route to fabricate optical elements by changing the spatiotemporal characteristics of ultrashort pulses.

Structure of Ce2RhIn8: an example of complementary use of high-resolution neutron powder diffraction and reciprocal-space mapping to study complex materials.

PubMed

Moshopoulou, E G; Ibberson, R M; Sarrao, J L; Thompson, J D; Fisk, Z

2006-04-01

The room-temperature crystal structure of the heavy fermion antiferromagnet Ce2RhIn8, dicerium rhodium octaindide, has been studied by a combination of high-resolution synchrotron X-ray reciprocal-space mapping of single crystals and high-resolution time-of-flight neutron powder diffraction. The structure is disordered, exhibiting a complex interplay of non-periodic, partially correlated planar defects, coexistence and segregation of polytypic phases (induced by periodic planar ;defects'), mosaicity (i.e. domain misalignment) and non-uniform strain. These effects evolve as a function of temperature in a complicated way, but they remain down to low temperatures. The room-temperature diffraction data are best represented by a complex mixture of two polytypic phases, which are affected by non-periodic, partially correlated planar defects, differ slightly in their tetragonal structures, and exhibit different mosaicities and strain values. Therefore, Ce2RhIn8 approaches the paracrystalline state, rather than the classic crystalline state and thus several of the concepts of conventional single-crystal crystallography are inapplicable. The structural results are discussed in the context of the role of disorder in the heavy-fermion state and in the interplay between superconductivity and magnetism.

Apical extrusion of debris and irrigants using ProTaper hand, M-two rotary and WaveOne single file reciprocating system: An ex vivo study.

PubMed

Singh, Abhishek; Arunagiri, Doraiswamy; Pushpa, Shankarappa; Sawhny, Asheesh; Misra, Abhinav; Khetan, Kirti

2015-01-01

The purpose of this ex vivo study was to evaluate and compare the weight of debris and volume of irrigant extruded apically from teeth using different preparation techniques. Thirty extracted human mandibular premolars with single canals and similar lengths were instrumented using hand ProTaper F2 (25, 0.08; Dentsply Maillefer, Ballaigues, Switzerland), M-two (25, 0.06; VDW, Munich, Germany) and WaveOne Primary (25, 0.08; Dentsply Maillefer, Ballaigues, Switzerland). Debris and irrigant extruded during instrumentation were collected into preweighed Eppendorf tubes. The volume of the irrigant was measured, and then the tubes were stored in an incubator at 70°C for 2 days. The Eppendorf tubes were weighed to obtain the final weight when the extruded debris was included. Three consecutive weights were obtained for each tube. Data were statistically analyzed by one-way analysis of variance and Student's t-test. There were no statistically significant differences among the groups. The WaveOne reciprocating system showed the maximum amount of apical extrusion of debris and irrigant among all the groups. The least amount of debris and irrigant was observed in ProTaper hand instrument (P > 0.05). All instrumentation techniques were associated with debris and irrigant extrusion.

Neural correlate of human reciprocity in social interactions

PubMed Central

Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

2013-01-01

Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions. PMID:24381534

Neural correlate of human reciprocity in social interactions.

PubMed

Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

2013-01-01

Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions.

Imperfect information facilitates the evolution of reciprocity.

PubMed

Kurokawa, Shun

2016-06-01

The existence of cooperation demands explanation since cooperation is costly to the actor. Reciprocity has long been regarded as a potential explanatory mechanism for the existence of cooperation. Reciprocity is a mechanism wherein a cooperator responds to an opponent's behavior by switching his/her own behavior. Hence, a possible problematic case relevant to the theory of reciprocity evolution arises when the mechanism is such that the information regarding an opponent's behavior is imperfect. Although it has been confirmed also by previous theoretical studies that imperfect information interferes with the evolution of reciprocity, this argument is based on the assumption that there are no mistakes in behavior. And, a previous study presumed that it might be expected that when such mistakes occur, reciprocity can more readily evolve in the case of imperfect information than in the case of perfect information. The reason why the previous study considers so is that in the former case, reciprocators can miss defections incurred by other reciprocators' mistakes due to imperfect information, allowing cooperation to persist when such reciprocators meet. However, contrary to this expectation, the previous study has shown that even when mistakes occur, imperfect information interferes with the evolution of reciprocity. Nevertheless, the previous study assumed that payoffs are linear (i.e., that the effect of behavior is additive and there are no synergetic effects). In this study, we revisited the same problem but removed the assumption that payoffs are linear. We used evolutionarily stable strategy analysis to compare the condition for reciprocity to evolve when mistakes occur and information is imperfect with the condition for reciprocity to evolve when mistakes occur and information is perfect. Our study revealed that when payoffs are not linear, imperfect information can facilitate the evolution of reciprocity when mistakes occur; while when payoffs are linear, imperfect information disturbs the evolution of reciprocity even when mistakes occur. Imperfect information can encourage the evolution of cooperation. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of Glide Path Creating on Cyclic Fatigue Resistance of Reciproc and Reciproc Blue Nickel-titanium Files: A Laboratory Study.

PubMed

Özyürek, Taha; Uslu, Gülşah; Yılmaz, Koray; Gündoğar, Mustafa

2018-06-01

The purpose of this article was to compare the cyclic fatigue resistance of Reciproc and Reciproc Blue files (VDW GmbH, Munich, Germany) that were used to prepare root canals of mandibular molar teeth with or without a glide path. Sixty Reciproc R25 and 60 Reciproc Blue R25 files were used. The Reciproc and Reciproc Blue groups were divided into 3 subgroups (ie, as received condition, used without a glide path, and used with a glide path). All the instruments were rotated in a stainless steel artificial canal with an inner diameter of 1.5 mm, a 60° angle of curvature, and a radius of curvature of 5 mm until fracture occurred. The number of cycle to fracture was calculated, and the length of the fractured segments was measured. The Kruskal-Wallis test was performed to statistically analyze the data using SPSS 21.0 software (IBM Corp, Armonk, NY) at a 5% significance level. The cyclic fatigue resistance of as received condition Reciproc Blue files was found to be higher than as received condition Reciproc files (P < .05). Reciproc Blue files used for root canal preparation showed higher cyclic fatigue resistance than Reciproc files used for root canal preparation (P < .05). There was no statistically significant difference between Reciproc and Reciproc Blue files used with a glide path and without a glide path (P > .05). There was no statistically significant difference in the mean length of the fractured fragments of the instruments (P > .05). Within the limitations of this in vitro study, it was concluded that creating a glide path using ProGlider files had no effect on the cyclic fatigue resistance of RPC and RPC Blue files. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Reciprocity-Based Reasons for Benefiting Research Participants: Most Fail, the Most Plausible is Problematic

PubMed Central

Sofaer, Neema

2014-01-01

A common reason for giving research participants post-trial access (PTA) to the trial intervention appeals to reciprocity, the principle, stated most generally, that if one person benefits a second, the second should reciprocate: benefit the first in return. Many authors consider it obvious that reciprocity supports PTA. Yet their reciprocity principles differ, with many authors apparently unaware of alternative versions. This article is the first to gather the range of reciprocity principles. It finds that: (1) most are false. (2) The most plausible principle, which is also problematic, applies only when participants experience significant net risks or burdens. (3) Seldom does reciprocity support PTA for participants or give researchers stronger reason to benefit participants than equally needy non-participants. (4) Reciprocity fails to explain the common view that it is bad when participants in a successful trial have benefited from the trial intervention but lack PTA to it. PMID:24602060

30 CFR 955.5 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... not granted through reciprocity. Reciprocity means the recognition by OSM of a blaster certificate... subsequent certificate that is not granted through reciprocity and for which additional training and... blaster certificate a subsequent certificate that is not granted through reciprocity and for which...

30 CFR 955.5 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... not granted through reciprocity. Reciprocity means the recognition by OSM of a blaster certificate... subsequent certificate that is not granted through reciprocity and for which additional training and... blaster certificate a subsequent certificate that is not granted through reciprocity and for which...

30 CFR 955.5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... not granted through reciprocity. Reciprocity means the recognition by OSM of a blaster certificate... subsequent certificate that is not granted through reciprocity and for which additional training and... blaster certificate a subsequent certificate that is not granted through reciprocity and for which...

30 CFR 955.5 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... not granted through reciprocity. Reciprocity means the recognition by OSM of a blaster certificate... subsequent certificate that is not granted through reciprocity and for which additional training and... blaster certificate a subsequent certificate that is not granted through reciprocity and for which...

30 CFR 955.5 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... not granted through reciprocity. Reciprocity means the recognition by OSM of a blaster certificate... subsequent certificate that is not granted through reciprocity and for which additional training and... blaster certificate a subsequent certificate that is not granted through reciprocity and for which...

Bromeliad growth and stoichiometry: responses to atmospheric nutrient supply in fog-dependent ecosystems of the hyper-arid Atacama Desert, Chile.

PubMed

González, Angélica L; Fariña, José Miguel; Pinto, Raquel; Pérez, Cecilia; Weathers, Kathleen C; Armesto, Juan J; Marquet, Pablo A

2011-11-01

Carbon, nitrogen, and phosphorus (C, N, P) stoichiometry influences the growth of plants and nutrient cycling within ecosystems. Indeed, elemental ratios are used as an index for functional differences between plants and their responses to natural or anthropogenic variations in nutrient supply. We investigated the variation in growth and elemental content of the rootless terrestrial bromeliad Tillandsia landbeckii, which obtains its moisture, and likely its nutrients, from coastal fogs in the Atacama Desert. We assessed (1) how fog nutrient supply influences plant growth and stoichiometry and (2) the response of plant growth and stoichiometry to variations in nutrient supply by using reciprocal transplants. We hypothesized that T. landbeckii should exhibit physiological and biochemical plastic responses commensurate with nutrient supply from atmospheric deposition. In the case of the Atacama Desert, nutrient supply from fog is variable over space and time, which suggests a relatively high variation in the growth and elemental content of atmospheric bromeliads. We found that the nutrient content of T. landbeckii showed high spatio-temporal variability, driven partially by fog nutrient deposition but also by plant growth rates. Reciprocal transplant experiments showed that transplanted individuals converged to similar nutrient content, growth rates, and leaf production of resident plants at each site, reflecting local nutrient availability. Although plant nutrient content did not exactly match the relative supply of N and P, our results suggest that atmospheric nutrient supply is a dominant driver of plant growth and stoichiometry. In fact, our results indicate that N uptake by T. landbeckii plants depends more on N supplied by fog, whereas P uptake is mainly regulated by within-plant nutrient demand for growth. Overall, these findings indicate that variation in fog nutrient supply exerts a strong control over growth and nutrient dynamics of atmospheric plants, which are ubiquitous across fog-dominated ecosystems.

78 FR 53792 - Draft Guidance for Reciprocity

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-30

... NUCLEAR REGULATORY COMMISSION [NRC-2013-0186] Draft Guidance for Reciprocity AGENCY: Nuclear... Commission (NRC) is revising its licensing guidance for reciprocity. The NRC is requesting public comment on... Work in Agreement State Jurisdiction (Reciprocity).'' The document has been updated from the previous...

Reciprocating pellet press

DOEpatents

Jones, Charles W.

1981-04-07

A machine for pressing loose powder into pellets using a series of reciprocating motions has an interchangeable punch and die as its only accurately machines parts. The machine reciprocates horizontally between powder receiving and pressing positions. It reciprocates vertically to press, strip and release a pellet.

Alternative energy efficient membrane bioreactor using reciprocating submerged membrane.

PubMed

Ho, J; Smith, S; Roh, H K

2014-01-01

A novel membrane bioreactor (MBR) pilot system, using membrane reciprocation instead of air scouring, was operated at constant high flux and daily fluctuating flux to demonstrate its application under peak and diurnal flow conditions. Low and stable transmembrane pressure was achieved at 40 l/m(2)/h (LMH) by use of repetitive membrane reciprocation. The results reveal that the inertial forces acting on the membrane fibers effectively propel foulants from the membrane surface. Reciprocation of the hollow fiber membrane is beneficial for the constant removal of solids that may build up on the membrane surface and inside the membrane bundle. The membrane reciprocation in the reciprocating MBR pilot consumed less energy than coarse air scouring used in conventional MBR systems. Specific energy consumption for the membrane reciprocation was 0.072 kWh/m(3) permeate produced at 40 LMH flux, which is 75% less than for a conventional air scouring system as reported in literature without consideration of energy consumption for biological aeration (0.29 kWh/m(3)). The daily fluctuating flux test confirmed that the membrane reciprocation is effective to handle fluctuating flux up to 50 LMH. The pilot-scale reciprocating MBR system successfully demonstrated that fouling can be controlled via 0.43 Hz membrane reciprocation with 44 mm or higher amplitude.

Canal shaping with WaveOne Primary reciprocating files and ProTaper system: a comparative study.

PubMed

Berutti, Elio; Chiandussi, Giorgio; Paolino, Davide Salvatore; Scotti, Nicola; Cantatore, Giuseppe; Castellucci, Arnaldo; Pasqualini, Damiano

2012-04-01

This study compared the canal curvature and axis modification after instrumentation with WaveOne Primary reciprocating files (Dentsply Maillefer, Ballaigues, Switzerland) and nickel-titanium (NiTi) rotary ProTaper (Dentsply Maillefer). Thirty ISO 15, 0.02 taper, Endo Training Blocks (Dentsply Maillefer) were used. In all specimens, the glide path was achieved with PathFile 1, 2, and 3 (Dentsply Maillefer) at the working length (WL). Specimens were then assigned to 1 of 2 groups for shaping: specimens in group 1 were shaped with ProTaper S1-S2-F1-F2 at the WL and specimens in group 2 were shaped with WaveOne Primary reciprocating files at the WL. Pre- and postinstrumentation digital images were superimposed and processed with Matlab r2010b (The MathWorks Inc, Natick, MA) software to analyze the curvature-radius ratio (CRr) and the relative axis error (rAe), representing canal curvature modification. Data were analyzed with one-way balanced analyses of variance at 2 levels (P < .05). The instrument factor was extremely significant for both the CRr parameter (F(1) = 9.59, P = .004) and the rAe parameter (F(1) = 13.55, P = .001). Canal modifications are reduced when the new WaveOne NiTi single-file system is used. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A Longitudinal Investigation of Anxiety and Depressive Symptomatology and Exercise Behaviour Among Adults With Type 2 Diabetes Mellitus.

PubMed

Ivanova, Elena; Burns, Rachel J; Deschênes, Sonya S; Knäuper, Bärbel; Schmitz, Norbert

2017-02-01

Evidence suggests that symptoms of depression and anxiety predict lower exercise behaviour and, inversely, that less exercise predicts higher symptomatology. The present longitudinal study examined this reciprocal association in adults with type 2 diabetes mellitus. We predicted that symptoms of anxiety or depression would intensify over time as a consequence of lower exercise frequency and, similarly, that exercise frequency would decrease as a consequence of greater symptoms of anxiety or depression. We studied 1691 adults with type 2 diabetes who provided baseline measures in 2011 and 2 subsequent annual assessments (Follow-up 1 and Follow-up 2). Symptoms of depression and anxiety were measured using the Patient Health Questionnaire-9 and the Generalized Anxiety Disorder-7, respectively. A single item assessed exercise frequency in the past month (in days). Separate 3-wave cross-lagged path models for symptoms of anxiety and depression tested the reciprocal associations. Contrary to our hypotheses, the reciprocal associations were not supported and, by extension, the predicted secondary associations were not tested. In sum, only depressive symptoms negatively predicted subsequent exercise frequency (Follow-up 1 and Follow-up 2). Symptoms of depression were prospectively associated with lower exercise frequency, which is consistent with evidence from population-based studies that identify depressive symptoms as a barrier to exercise participation. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Advanced development of BEM for elastic and inelastic dynamic analysis of solids

NASA Technical Reports Server (NTRS)

Banerjee, P. K.; Ahmad, S.; Wang, H. C.

1989-01-01

Direct Boundary Element formulations and their numerical implementation for periodic and transient elastic as well as inelastic transient dynamic analyses of two-dimensional, axisymmetric and three-dimensional solids are presented. The inelastic formulation is based on an initial stress approach and is the first of its kind in the field of Boundary Element Methods. This formulation employs the Navier-Cauchy equation of motion, Graffi's dynamic reciprocal theorem, Stokes' fundamental solution, and the divergence theorem, together with kinematical and constitutive equations to obtain the pertinent integral equations of the problem in the time domain within the context of the small displacement theory of elastoplasticity. The dynamic (periodic, transient as well as nonlinear transient) formulations have been applied to a range of problems. The numerical formulations presented here are included in the BEST3D and GPBEST systems.

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

Frayce, D.; Khayat, R.E.; Derdouri, A.

The dual reciprocity boundary element method (DRBEM) is implemented to solve three-dimensional transient heat conduction problems in the presence of arbitrary sources, typically as these problems arise in materials processing. The DRBEM has a major advantage over conventional BEM, since it avoids the computation of volume integrals. These integrals stem from transient, nonlinear, and/or source terms. Thus there is no need to discretize the inner domain, since only a number of internal points are needed for the computation. The validity of the method is assessed upon comparison with results from benchmark problems where analytical solutions exist. There is generally goodmore » agreement. Comparison against finite element results is also favorable. Calculations are carried out in order to assess the influence of the number and location of internal nodes. The influence of the ratio of the numbers of internal to boundary nodes is also examined.« less

Reciprocity on the Hardwood: Passing Patterns among Professional Basketball Players

PubMed Central

Willer, Robb; Sharkey, Amanda; Frey, Seth

2012-01-01

Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA) games of the 2008–9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had “received” assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity – a tendency to “pay forward” assists – and only very limited evidence for indirect reciprocity – a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition. PMID:23236354

Reciprocity on the hardwood: passing patterns among professional basketball players.

PubMed

Willer, Robb; Sharkey, Amanda; Frey, Seth

2012-01-01

Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA) games of the 2008-9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had "received" assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity - a tendency to "pay forward" assists - and only very limited evidence for indirect reciprocity - a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition.

32 CFR 634.16 - Reciprocal state-military action.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and direct the installation law enforcement officer to pursue reciprocity with state or host nation... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize official... agreement concerning reciprocity may be permitted at a particular overseas installation, the commander must...

32 CFR 634.16 - Reciprocal state-military action.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and direct the installation law enforcement officer to pursue reciprocity with state or host nation... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize official... agreement concerning reciprocity may be permitted at a particular overseas installation, the commander must...

32 CFR 634.16 - Reciprocal state-military action.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and direct the installation law enforcement officer to pursue reciprocity with state or host nation... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize official... agreement concerning reciprocity may be permitted at a particular overseas installation, the commander must...

32 CFR 634.16 - Reciprocal state-military action.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and direct the installation law enforcement officer to pursue reciprocity with state or host nation... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize official... agreement concerning reciprocity may be permitted at a particular overseas installation, the commander must...

Reciprocity of Interpersonal Attraction: A Confirmed Hypothesis.

ERIC Educational Resources Information Center

La Voie, Lawrence; Kenny, David A.

An increase in reciprocity of interpersonal attraction during the early acquaintance period followed by continuing social reciprocity are propositions that are central principles of several social psychological viewpoints. However, there is little empirical evidence of increasing reciprocity of interpersonal attraction over time. Two potential…

Effect of holding office on the behavior of politicians

PubMed Central

Enemark, Daniel; Gibson, Clark C.; McCubbins, Mathew D.; Seim, Brigitte

2016-01-01

Reciprocity is central to our understanding of politics. Most political exchanges—whether they involve legislative vote trading, interbranch bargaining, constituent service, or even the corrupt exchange of public resources for private wealth—require reciprocity. But how does reciprocity arise? Do government officials learn reciprocity while holding office, or do recruitment and selection practices favor those who already adhere to a norm of reciprocity? We recruit Zambian politicians who narrowly won or lost a previous election to play behavioral games that provide a measure of reciprocity. This combination of regression discontinuity and experimental designs allows us to estimate the effect of holding office on behavior. We find that holding office increases adherence to the norm of reciprocity. This study identifies causal effects of holding office on politicians’ behavior. PMID:27856736

Effect of holding office on the behavior of politicians.

PubMed

Enemark, Daniel; Gibson, Clark C; McCubbins, Mathew D; Seim, Brigitte

2016-11-29

Reciprocity is central to our understanding of politics. Most political exchanges-whether they involve legislative vote trading, interbranch bargaining, constituent service, or even the corrupt exchange of public resources for private wealth-require reciprocity. But how does reciprocity arise? Do government officials learn reciprocity while holding office, or do recruitment and selection practices favor those who already adhere to a norm of reciprocity? We recruit Zambian politicians who narrowly won or lost a previous election to play behavioral games that provide a measure of reciprocity. This combination of regression discontinuity and experimental designs allows us to estimate the effect of holding office on behavior. We find that holding office increases adherence to the norm of reciprocity. This study identifies causal effects of holding office on politicians' behavior.

Efficient inversion of volcano deformation based on finite element models : An application to Kilauea volcano, Hawaii

NASA Astrophysics Data System (ADS)

Charco, María; González, Pablo J.; Galán del Sastre, Pedro

2017-04-01

The Kilauea volcano (Hawaii, USA) is one of the most active volcanoes world-wide and therefore one of the better monitored volcanoes around the world. Its complex system provides a unique opportunity to investigate the dynamics of magma transport and supply. Geodetic techniques, as Interferometric Synthetic Aperture Radar (InSAR) are being extensively used to monitor ground deformation at volcanic areas. The quantitative interpretation of such surface ground deformation measurements using geodetic data requires both, physical modelling to simulate the observed signals and inversion approaches to estimate the magmatic source parameters. Here, we use synthetic aperture radar data from Sentinel-1 radar interferometry satellite mission to image volcano deformation sources during the inflation along Kilauea's Southwest Rift Zone in April-May 2015. We propose a Finite Element Model (FEM) for the calculation of Green functions in a mechanically heterogeneous domain. The key aspect of the methodology lies in applying the reciprocity relationship of the Green functions between the station and the source for efficient numerical inversions. The search for the best-fitting magmatic (point) source(s) is generally conducted for an array of 3-D locations extending below a predefined volume region. However, our approach allows to reduce the total number of Green functions to the number of the observation points by using the, above mentioned, reciprocity relationship. This new methodology is able to accurately represent magmatic processes using physical models capable of simulating volcano deformation in non-uniform material properties distribution domains, which eventually will lead to better description of the status of the volcano.

Percussion tool

DOEpatents

Reed, Teddy R.

2006-11-28

A percussion tool is described and which includes a housing mounting a tool bit; a reciprocally moveable hammer borne by the housing and which is operable to repeatedly strike the tool bit; and a reciprocally moveable piston enclosed within the hammer and which imparts reciprocal movement to the reciprocally moveable hammer.

The Personal Norm of Reciprocity among mental health service users: conceptual development and measurement.

PubMed

Matejkowski, Jason; McCarthy, Kevin S; Draine, Jeffrey

2011-01-01

A measure of an individual's level of internalization of the norm of reciprocity may signal exchange preferences and indicate whether "active" or "passive" mental health services are preferable to consumers. We evaluated the psychometric properties of one such measure, the Personal Norm of Reciprocity (PNR) scale. We recruited 70 persons receiving mental health services and 65 comparison participants to complete questionnaires assessing reciprocity tendencies and correlates of mental illness. Two of three subscales of a shortened PNR showed evidence of reliability and validity. Consumers endorsed higher levels of the reciprocity norm than persons not seeking services. Persons in "active" service settings displayed greater rigidity in application of the reciprocity norm than individuals in "passive" service settings or comparison participants. The shortened PNR can be a useful measure of individual reciprocity preferences. Measurement of the internalization of the norm of reciprocity may assist practitioners in identifying what types of services are more likely to retain and benefit mental health service consumers.

Reciprocity-based reasons for benefiting research participants: most fail, the most plausible is problematic.

PubMed

Sofaer, Neema

2014-11-01

A common reason for giving research participants post-trial access (PTA) to the trial intervention appeals to reciprocity, the principle, stated most generally, that if one person benefits a second, the second should reciprocate: benefit the first in return. Many authors consider it obvious that reciprocity supports PTA. Yet their reciprocity principles differ, with many authors apparently unaware of alternative versions. This article is the first to gather the range of reciprocity principles. It finds that: (1) most are false. (2) The most plausible principle, which is also problematic, applies only when participants experience significant net risks or burdens. (3) Seldom does reciprocity support PTA for participants or give researchers stronger reason to benefit participants than equally needy non-participants. (4) Reciprocity fails to explain the common view that it is bad when participants in a successful trial have benefited from the trial intervention but lack PTA to it. © 2013 John Wiley & Sons Ltd.

A multipurpose ultra-high vacuum-compatible chamber for in situ X-ray surface scattering studies over a wide range of temperature and pressure environment conditions

NASA Astrophysics Data System (ADS)

Ferrer, P.; Rubio-Zuazo, J.; Heyman, C.; Esteban-Betegón, F.; Castro, G. R.

2013-03-01

A low/high temperature (60-1000K) and pressure (10-10-3x103 mbar) "baby chamber", specially adapted to the grazing-incidence X-ray scattering station, has been designed, developed and installed at the Spanish CRG BM25 SpLine beamline at European Synchrotron Radiation Facility. The chamber has a cylindrical form with 100 mm of diameter, built on a 360° beryllium nipple of 150 mm height. The UHV equipment and a turbo pump are located on the upper part of the chamber to leave a wide solid angle for exploring reciprocal space. The chamber features 4 CF16 and 5 CF40 ports for electrical feed through and leak valves, ion gun, etc. The heat exchanger is a customized compact LN2 (or LHe) continuous flow cryostat. The sample is mounted on a Mo support on the heat exchanger, which has in the back side a BORALECTRIC® Heater Elements. Experiments of surfaces/interfaces/ multilayer materials, thin films or single crystals in a huge variety of environments can be performed, also in situ studies of growth or evolution of the samples. Data measurement can be collected with a punctual and a bi-dimensional detector, being possible to simultaneously use them.

Apical Extrusion of Intracanal Bacteria with Single File and Multifile Rotary Instrumentation Systems.

PubMed

Saberi, Eshaghali; Zahedani, Shahram Shahraki; Ebrahimipour, Sediqe

2017-01-01

Instrumentation techniques may cause extrusion of microorganisms and their products into the periapical region resulting inflammation and treatment failure. The aim of this ex vivo study was comparing the apical bacterial extrusion in canals prepared with single file versus multiple file rotary systems. Ninety-two human single-rooted mandibular first premolars were used. Endodontic access cavities were prepared, and root canals were contaminated with an Enterococcus faecalis ( E. faecalis ) suspension. The samples were incubated at 37°C for 30 days; the contaminated teeth were divided into four groups of 20 specimens each (1: Reciproc, 2: Mtwo, 3: Neoniti A1, 4: Safesider). Six teeth were not infected and each were prepared with one of the above instruments were considered as negative and six teeth which had been previously infected, were used as positive control groups. Extruded bacteria from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbial samples were taken from the vials and incubated in brain heart agar medium for 24 h. The resulting bacterial titer, in colony-forming units per mL, was determined. The data entered into SPSS 18 software and were analyzed by Kruskal-Wallis and Mann-Whitney U-tests at 0.05 significance level. Mtwo multifile system showed significantly less bacterial extrusion than Safesider ( P = 0.015) and Neoniti A1 ( P = 0.042) but did not show significant difference with Reciproc system ( P = 0.25). All instrumentation systems extruded bacteria beyond the apical foramen. However, this study showed that Mtwo multifile rotary system extruded fewer bacteria.

Attitudes toward reciprocity systems for organ donation and allocation for transplantation.

PubMed

Burkell, Jacquelyn A; Chandler, Jennifer A; Shemie, Sam D

2013-10-01

Many of those who support organ donation do not register to become organ donors. The use of reciprocity systems, under which some degree of priority is offered to registered donors who require an organ transplant, is one suggestion for increasing registration rates. This article uses a combination of survey and focus group methodologies to explore the reaction of Canadians to a reciprocity proposal. Our results suggest that the response is mixed. Participants are more convinced of the efficacy than they are of the fairness of a reciprocity system. Those more positive about donation (decided donors and those leaning toward donation) rate the system more positively. Although there is general endorsement of the notion that those who wish to receive should be prepared to give (the Golden Rule), this does not translate into universal support for a reciprocity system. In discussions of efficacy, decided donors focus on the positive impact of reciprocity, whereas undecided donors also reflect on the limits of reciprocity for promoting registration. The results demonstrate divided support for reciprocity systems in the Canadian context, with perceptions of efficacy at the cost of fairness. Further studies are warranted prior to considering a reciprocity system in Canada.

Symmetry-based reciprocity: evolutionary constraints on a proximate mechanism

PubMed Central

Campennì, Marco

2016-01-01

Background. While the evolution of reciprocal cooperation has attracted an enormous attention, the proximate mechanisms underlying the ability of animals to cooperate reciprocally are comparatively neglected. Symmetry-based reciprocity is a hypothetical proximate mechanism that has been suggested to be widespread among cognitively unsophisticated animals. Methods. We developed two agent-based models of symmetry-based reciprocity (one relying on an arbitrary tag and the other on interindividual proximity) and tested their ability both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Results. Populations formed by agents adopting symmetry-based reciprocity showed differentiated “social relationships” and a positive correlation between cooperation given and received: two common aspects of animal cooperation. However, when reproduction and selection across multiple generations were added to the models, agents adopting symmetry-based reciprocity were outcompeted by selfish agents that never cooperated. Discussion. In order to evolve, hypothetical proximate mechanisms must be able to stand competition from alternative strategies. While the results of our simulations require confirmation using analytical methods, we provisionally suggest symmetry-based reciprocity is to be abandoned as a possible proximate mechanism underlying the ability of animals to reciprocate cooperative interactions. PMID:26998412

Symmetry-based reciprocity: evolutionary constraints on a proximate mechanism.

PubMed

Campennì, Marco; Schino, Gabriele

2016-01-01

Background. While the evolution of reciprocal cooperation has attracted an enormous attention, the proximate mechanisms underlying the ability of animals to cooperate reciprocally are comparatively neglected. Symmetry-based reciprocity is a hypothetical proximate mechanism that has been suggested to be widespread among cognitively unsophisticated animals. Methods. We developed two agent-based models of symmetry-based reciprocity (one relying on an arbitrary tag and the other on interindividual proximity) and tested their ability both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Results. Populations formed by agents adopting symmetry-based reciprocity showed differentiated "social relationships" and a positive correlation between cooperation given and received: two common aspects of animal cooperation. However, when reproduction and selection across multiple generations were added to the models, agents adopting symmetry-based reciprocity were outcompeted by selfish agents that never cooperated. Discussion. In order to evolve, hypothetical proximate mechanisms must be able to stand competition from alternative strategies. While the results of our simulations require confirmation using analytical methods, we provisionally suggest symmetry-based reciprocity is to be abandoned as a possible proximate mechanism underlying the ability of animals to reciprocate cooperative interactions.

Effects of psychosocial variables in the similarity and interdependence of physical activity levels among adolescent best friend dyads.

PubMed

Lopes, Vítor P; Gabbard, Carl; Rodrigues, Luis P

2016-01-01

Given that physical activity (PA) tends to decrease with age during adolescence, addressing factors that affect change is important. This study examined the similarity and interdependence of PA as influenced by psychosocial factors among adolescent best friend dyads. A total of 660 adolescents, representing 330 best friend dyads, completed questionnaires with regard to PA, sitting time, perceived exercise benefits and barriers, physical self-perception and social support for PA. Dyads were also identified as reciprocal and non-reciprocal best friends; reciprocal means that both considered each other best friends and non-reciprocal were those in which only one considered the other a best friend. Data were analysed using a hierarchical linear model framework. Results indicated significant similarities between reciprocal best friend dyads for PA and sitting time, and for sitting time in non-reciprocal best friends (P values <.01). Psychosocial variables were associated with PA in reciprocal best friend dyads and with sitting time in reciprocal and non-reciprocal best friend dyads. Best friend gender, regular sports practice of the person, perceived exercise barriers of the best friend and best friend social support were the best predictors for PA.

Capuchin Monkeys Judge Third-Party Reciprocity

ERIC Educational Resources Information Center

Anderson, James R.; Takimoto, Ayaka; Kuroshima, Hika; Fujita, Kazuo

2013-01-01

Increasing interest is being shown in how children develop an understanding of reciprocity in social exchanges and fairness in resource distribution, including social exchanges between third parties. Although there are descriptions of reciprocity on a one-to-one basis in other species, whether nonhumans detect reciprocity and violations of…

32 CFR 156.6 - Common access card (CAC) investigation and adjudication.

Code of Federal Regulations, 2014 CFR

2014-07-01

... national background investigations may vary based on standing reciprocity treaties concerning identity... repository when available. (g) Reciprocity of CAC Determinations. (1) The sponsoring activity shall not re... determinations are not eligible to be transferred or reciprocally accepted. Reciprocity shall be based on final...

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Reciprocating-type air compressors. 56.13010...

30 CFR 57.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Reciprocating-type air compressors. 57.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

47 CFR 51.703 - Non-Access reciprocal compensation obligation of LECs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 3 2013-10-01 2013-10-01 false Non-Access reciprocal compensation obligation... Telecommunications Traffic § 51.703 Non-Access reciprocal compensation obligation of LECs. (a) Each LEC shall establish Non-Access Reciprocal Compensation arrangements for transport and termination of Non-Access...

47 CFR 51.703 - Non-Access reciprocal compensation obligation of LECs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 3 2012-10-01 2012-10-01 false Non-Access reciprocal compensation obligation... Telecommunications Traffic § 51.703 Non-Access reciprocal compensation obligation of LECs. (a) Each LEC shall establish Non-Access Reciprocal Compensation arrangements for transport and termination of Non-Access...

47 CFR 51.703 - Non-Access reciprocal compensation obligation of LECs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 3 2014-10-01 2014-10-01 false Non-Access reciprocal compensation obligation... Telecommunications Traffic § 51.703 Non-Access reciprocal compensation obligation of LECs. (a) Each LEC shall establish Non-Access Reciprocal Compensation arrangements for transport and termination of Non-Access...

Mortality salience increases personal relevance of the norm of reciprocity.

PubMed

Schindler, Simon; Reinhard, Marc-André; Stahlberg, Dagmar

2012-10-01

Research on terror management theory found evidence that people under mortality salience strive to live up to salient cultural norms and values, like egalitarianism, pacifism, or helpfulness. A basic, strongly internalized norm in most human societies is the norm of reciprocity: people should support those who supported them (i.e., positive reciprocity), and people should injure those who injured them (i.e., negative reciprocity), respectively. In an experiment (N = 98; 47 women, 51 men), mortality salience overall significantly increased personal relevance of the norm of reciprocity (M = 4.45, SD = 0.65) compared to a control condition (M = 4.19, SD = 0.59). Specifically, under mortality salience there was higher motivation to punish those who treated them unfavourably (negative norm of reciprocity). Unexpectedly, relevance of the norm of positive reciprocity remained unaffected by mortality salience. Implications and limitations are discussed.

Reciprocity and depressive symptoms in Belgian workers: a cross-sectional multilevel analysis.

PubMed

De Clercq, Bart; Clays, Els; Janssens, Heidi; De Bacquer, Dirk; Casini, Annalisa; Kittel, France; Braeckman, Lutgart

2013-07-01

This study examines the multidimensional association between reciprocity at work and depressive symptoms. Data from the Belgian BELSTRESS survey (32 companies; N = 24,402) were analyzed. Multilevel statistical procedures were used to account for company-level associations while controlling for individual-level associations. Different dimensions of individual reciprocity were negatively associated with depressive symptoms. On the company level, only vertical emotional reciprocity was negatively associated (β = -4.660; SE = 1.117) independently from individual reciprocity (β = -0.557; SE = 0.042). Complex interactions were found such that workplace reciprocity (1) may not uniformly benefit individuals and (2) related differently to depressive symptoms, depending on occupational group. This study extends the existing literature with evidence on the multidimensional, contextual, and cross-level interaction associations of reciprocity as a key aspect of social capital on depressive symptoms.

[The reciprocity rule in the construction of relationships as the key in relational processes].

PubMed

Fenelli, Antonio; Volpi, Cecilia; Guarracino, Emanuele; Galli, Virginia; Esposito, Massimo

2011-01-01

Reciprocity as an expression of the therapist-patient relationship is pointed-out by Mario Reda who refers to Comparetti's studies on the mother-foetus reciprocity, mediated by the so-called "jumps". Reciprocal behaviours are clearly observable during bird and other animal courtship behaviour, whereas in the Sapiens sapiens species, we may observe the establishing of a very complex reciprocity system, which starts with gestures and bodily attitudes, subsequently activating sensory-motor emotional schemata and internal working models, thus enabling the construction of personal meanings. A relationship may result from an encounter provided that "compatible" meanings are constructed in the context of "possible reciprocity" of significant systems. The observation of reciprocity provides a concrete possibility to reduce the risk of absolute subjectivity related to the I or the you, superceding it through the us.

30 CFR 955.16 - Reciprocity.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Reciprocity. 955.16 Section 955.16 Mineral... AND ON INDIAN LANDS § 955.16 Reciprocity. (a) Grant of certificate. OSM shall grant an OSM blaster certificate through reciprocity to any qualified applicant who demonstrates that he or she, and whom OSM finds...

46 CFR 8.120 - Reciprocity.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Reciprocity. 8.120 Section 8.120 Shipping COAST GUARD... § 8.120 Reciprocity. (a) The Commandant may delegate authority to a classification society that has... determine reciprocity on a “case-by-case” basis. (b) In order to demonstrate that the conditions described...

46 CFR 8.120 - Reciprocity.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Reciprocity. 8.120 Section 8.120 Shipping COAST GUARD... § 8.120 Reciprocity. (a) The Commandant may delegate authority to a classification society that has... determine reciprocity on a “case-by-case” basis. (b) In order to demonstrate that the conditions described...

46 CFR 8.120 - Reciprocity.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Reciprocity. 8.120 Section 8.120 Shipping COAST GUARD... § 8.120 Reciprocity. (a) The Commandant may delegate authority to a classification society that has... determine reciprocity on a “case-by-case” basis. (b) In order to demonstrate that the conditions described...

30 CFR 955.16 - Reciprocity.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Reciprocity. 955.16 Section 955.16 Mineral... AND ON INDIAN LANDS § 955.16 Reciprocity. (a) Grant of certificate. OSM shall grant an OSM blaster certificate through reciprocity to any qualified applicant who demonstrates that he or she, and whom OSM finds...

30 CFR 955.16 - Reciprocity.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Reciprocity. 955.16 Section 955.16 Mineral... AND ON INDIAN LANDS § 955.16 Reciprocity. (a) Grant of certificate. OSM shall grant an OSM blaster certificate through reciprocity to any qualified applicant who demonstrates that he or she, and whom OSM finds...

Context-Specific Effects on Reciprocity in Mentoring Relationships: Ethical Implications

ERIC Educational Resources Information Center

Shore, Wendelyn J.; Toyokawa, Teru; Anderson, Dana D.

2008-01-01

Reciprocity is fundamental to effective mentoring relationships. However, we argue that it is inappropriate, and perhaps unethical, to expect comparable levels of reciprocity in all mentoring relationships. Instead, contextual factors influence optimal levels of reciprocity. Foremost is the developmental stage of the protege, with less mature,…

30 CFR 955.16 - Reciprocity.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Reciprocity. 955.16 Section 955.16 Mineral... AND ON INDIAN LANDS § 955.16 Reciprocity. (a) Grant of certificate. OSM shall grant an OSM blaster certificate through reciprocity to any qualified applicant who demonstrates that he or she, and whom OSM finds...

46 CFR 8.120 - Reciprocity.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Reciprocity. 8.120 Section 8.120 Shipping COAST GUARD... § 8.120 Reciprocity. (a) The Commandant may delegate authority to a classification society that has... determine reciprocity on a “case-by-case” basis. (b) In order to demonstrate that the conditions described...

30 CFR 955.16 - Reciprocity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Reciprocity. 955.16 Section 955.16 Mineral... AND ON INDIAN LANDS § 955.16 Reciprocity. (a) Grant of certificate. OSM shall grant an OSM blaster certificate through reciprocity to any qualified applicant who demonstrates that he or she, and whom OSM finds...

46 CFR 8.120 - Reciprocity.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Reciprocity. 8.120 Section 8.120 Shipping COAST GUARD... § 8.120 Reciprocity. (a) The Commandant may delegate authority to a classification society that has... determine reciprocity on a “case-by-case” basis. (b) In order to demonstrate that the conditions described...

14 CFR 135.371 - Large transport category airplanes: Reciprocating engine powered: En route limitations: One...

Code of Federal Regulations, 2010 CFR

2010-01-01

... Limitations § 135.371 Large transport category airplanes: Reciprocating engine powered: En route limitations... reciprocating engine powered large transport category airplane may take off that airplane at a weight, allowing..., under an approved procedure, operate a reciprocating engine powered large transport category airplane at...

An Inquiry into Relationship Suicides and Reciprocity

ERIC Educational Resources Information Center

Davis, Mark S.; Callanan, Valerie J.; Lester, David; Haines, Janet

2009-01-01

Few theories on suicide have been grounded in the norm of reciprocity. There is literature on suicide, however, describing motivations such as retaliation and retreat which can be interpreted as modes of adaptation to the norm of reciprocity. We propose a reciprocity-based theory to explain suicides associated with relationship problems. Employing…

Excitons in boron nitride single layer

NASA Astrophysics Data System (ADS)

Galvani, Thomas; Paleari, Fulvio; Miranda, Henrique P. C.; Molina-Sánchez, Alejandro; Wirtz, Ludger; Latil, Sylvain; Amara, Hakim; Ducastelle, François

2016-09-01

Boron nitride single layer belongs to the family of two-dimensional materials whose optical properties are currently receiving considerable attention. Strong excitonic effects have already been observed in the bulk and still stronger effects are predicted for single layers. We present here a detailed study of these properties by combining ab initio calculations and a tight-binding Wannier analysis in both real and reciprocal space. Due to the simplicity of the band structure with single valence (π ) and conduction (π*) bands the tight-binding analysis becomes quasiquantitative with only two adjustable parameters and provides tools for a detailed analysis of the exciton properties. Strong deviations from the usual hydrogenic model are evidenced. The ground-state exciton is not a genuine Frenkel exciton, but a very localized tightly bound one. The other ones are similar to those found in transition-metal dichalcogenides and, although more localized, can be described within a Wannier-Mott scheme.

De novo reciprocal translocation t(5;11)(q22;p15) associated with hydrops fetalis (reciprocal translocation and hydrops fetalis).

PubMed

Pala, Halil Gursoy; Artunc-Ulkumen, Burcu; Uyar, Yildiz; Bal, Filiz; Baytur, Yesim Bulbul; Koyuncu, Faik Mumtaz

2015-02-01

This is a case of a prenatally diagnosed non-immune hydrops fetalis (NIHF) associated with translocation t(5;11)(q22;p15). An association between NIHF and this translocation has not been reported previously. The patient was referred to the perinatology clinic with hydrops fetalis diagnosis at 23 weeks' gestation. We noted that the fetus had bilateral pleural effusion, ascites, widespread subcutaneous edema, membranous ventricular septal defect, hypoplastic fifth finger middle phalanx, clinodactyly, single umbilical artery. We performed cordocentesis. Chromosomal analysis on blood showed a balanced translocation between the long arm of chromosome 5 and the short arm of chromosome 11 with karyotype of 46,XX,t(5;11)(q22;p15). We present prenatal diagnosis of a de novo translocation (5;11) in a hydropic fetus with ultrason abnormalities. In our case, karyotype analysis of the fetus, mother and father provided evidence of a de novo translocation, that might explain the NIHF.

The swimming of a perfect deforming helix

NASA Astrophysics Data System (ADS)

Koens, Lyndon; Zhang, Hang; Mourran, Ahmed; Lauga, Eric

2017-11-01

Many bacteria rotate helical flagellar filaments in order to swim. When at rest or rotated counter-clockwise these flagella are left handed helices but they undergo polymorphic transformations to right-handed helices when the motor is reversed. These helical deformations themselves can generate motion, with for example Rhodobacter sphaeroides using the polymorphic transformation of the flagellum to generate rotation, or Spiroplasma propagating a change of helix handedness across its body's length to generate forward motion. Recent experiments reported on an artificial helical microswimmer generating motion without a propagating change in handedness. Made of a temperature sensitive gel, these swimmers moved by changing the dimensions of the helix in a non-reciprocal way. Inspired by these results and helix's ubiquitous presence in the bacterial world, we investigate how a deforming helix moves within a viscous fluid. Maintaining a single handedness along its entire length, we discuss how a perfect deforming helix can create a non-reciprocal swimming stroke, identify its principle directions of motion, and calculate the swimming kinematics asymptotically.

Reciprocal genomic evolution in the ant–fungus agricultural symbiosis

PubMed Central

Nygaard, Sanne; Hu, Haofu; Li, Cai; Schiøtt, Morten; Chen, Zhensheng; Yang, Zhikai; Xie, Qiaolin; Ma, Chunyu; Deng, Yuan; Dikow, Rebecca B.; Rabeling, Christian; Nash, David R.; Wcislo, William T.; Brady, Seán G.; Schultz, Ted R.; Zhang, Guojie; Boomsma, Jacobus J.

2016-01-01

The attine ant–fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal cultivars. We show that ant subsistence farming probably originated in the early Tertiary (55–60 MYA), followed by further transitions to the farming of fully domesticated cultivars and leaf-cutting, both arising earlier than previously estimated. Evolutionary modifications in the ants include unprecedented rates of genome-wide structural rearrangement, early loss of arginine biosynthesis and positive selection on chitinase pathways. Modifications of fungal cultivars include loss of a key ligninase domain, changes in chitin synthesis and a reduction in carbohydrate-degrading enzymes as the ants gradually transitioned to functional herbivory. In contrast to human farming, increasing dependence on a single cultivar lineage appears to have been essential to the origin of industrial-scale ant agriculture. PMID:27436133

The impact of rapid evolution on population dynamics in the wild: experimental test of eco-evolutionary dynamics.

PubMed

Turcotte, Martin M; Reznick, David N; Hare, J Daniel

2011-11-01

Rapid evolution challenges the assumption that evolution is too slow to impact short-term ecological dynamics. This insight motivates the study of 'Eco-Evolutionary Dynamics' or how evolution and ecological processes reciprocally interact on short time scales. We tested how rapid evolution impacts concurrent population dynamics using an aphid (Myzus persicae) and an undomesticated host (Hirschfeldia incana) in replicated wild populations. We manipulated evolvability by creating non-evolving (single clone) and potentially evolving (two-clone) aphid populations that contained genetic variation in intrinsic growth rate. We observed significant evolution in two-clone populations whether or not they were exposed to predators and competitors. Evolving populations grew up to 42% faster and attained up to 67% higher density, compared with non-evolving control populations but only in treatments exposed to competitors and predators. Increased density also correlates with relative fitness of competing clones suggesting a full eco-evolutionary dynamic cycle defined as reciprocal interactions between evolution and density. © 2011 Blackwell Publishing Ltd/CNRS.

A 15 kWe (nominal) solar thermal-electric power conversion concept definition study: Steam Rankin reciprocator system

NASA Technical Reports Server (NTRS)

Wingenback, W.; Carter, J., Jr.

1979-01-01

A conceptual design of a 3600 rpm reciprocation expander was developed for maximum thermal input power of 80 kW. The conceptual design covered two engine configurations; a single cylinder design for simple cycle operation and a two cylinder design for reheat cycle operation. The reheat expander contains a high pressure cylinder and a low pressure cylinder with steam being reheated to the initial inlet temperature after expansion in the high pressure cylinder. Power generation is accomplished with a three-phase induction motor coupled directly to the expander and connected electrically to the public utility power grid. The expander, generator, water pump and control system weigh 297 kg and are dish mounted. The steam condenser, water tank and accessory pumps are ground based. Maximum heat engine efficiency is 33 percent: maximum power conversion efficiency is 30 percent. Total cost is $3,307 or $138 per kW of maximum output power.

Free-piston reciprocating cryogenic expander utilizing phase controller

NASA Astrophysics Data System (ADS)

Cha, Jeongmin; Park, Jiho; Kim, Kyungjoong; Jeong, Sangkwon

2017-02-01

In a free-piston expander which eliminates mechanical linkages, a prescribed behaviour of the free-piston movement is the key to an expander performance. In this paper, we have proposed an idea of reducing complexity of the free-piston expander. It is to replace both multiple solenoid valves and reservoirs that are indispensable in a previous machine with a combination of a single orifice-reservoir assembly. It functions as a phase controller like that of a pulse tube refrigerator so that it generates time-delay of pressure variation between the warm-end and the reservoir resulting in the intended expansion of the cold-end volume down to the pre-set reservoir pressure. The modeling of this unique free-piston reciprocating expander utilizing phase controller is developed to understand and predict the performance of the new-type expander. Additionally, the operating parameters are analysed at the specified conditions to enable one to develop a more efficient free-piston type cryogenic expander.

The calibration of photographic and spectroscopic films. 1: Film batch variations of reciprocity failure in IIaO film. 2: Thermal and aging effects in relationship to reciprocity failure. 3: Shifting of reciprocity failure points as a function of thermal and aging effects

NASA Technical Reports Server (NTRS)

Peters, K. A.; Atkinson, P. F.; Hammond, E. C., Jr.

1986-01-01

Reciprocity failure was examined for IIaO spectroscopic film. Three separate experiments were performed in order to study film batch variations, thermal and aging effects in relationship to reciprocity failure, and shifting of reciprocity failure points as a function of thermal and aging effects. The failure was examined over ranges of time between 5 and 60 seconds. The variation to illuminance was obtained by using thirty neutral density filters. A standard sensitometer device imprinted the wedge pattern on the film as exposure time was subjected to variation. The results indicate that film batch differences, temperature, and aging play an important role in reciprocity failure of IIaO spectroscopic film. A shifting of the failure points was also observed in various batches of film.

Realizing total reciprocity violation in the phase for photon scattering

PubMed Central

Deák, László; Bottyán, László; Fülöp, Tamás; Merkel, Dániel Géza; Nagy, Dénes Lajos; Sajti, Szilárd; Schulze, Kai Sven; Spiering, Hartmut; Uschmann, Ingo; Wille, Hans-Christian

2017-01-01

Reciprocity is when wave or quantum scattering satisfies a symmetry property, connecting a scattering process with the reversed one. While reciprocity involves the interchange of source and detector, it is fundamentally different from rotational invariance, and is a generalization of time reversal invariance, occurring in absorptive media as well. Due to its presence at diverse areas of physics, it admits a wide variety of applications. For polarization dependent scatterings, reciprocity is often violated, but violation in the phase of the scattering amplitude is much harder to experimentally observe than violation in magnitude. Enabled by the advantageous properties of nuclear resonance scattering of synchrotron radiation, we have measured maximal, i.e., 180-degree, reciprocity violation in the phase. For accessing phase information, we introduced a new version of stroboscopic detection. The scattering setting was devised based on a generalized reciprocity theorem that opens the way to construct new types of reciprocity related devices. PMID:28225031

The neural correlates of reciprocity are sensitive to prior experience of reciprocity.

PubMed

Cáceda, Ricardo; Prendes-Alvarez, Stefania; Hsu, Jung-Jiin; Tripathi, Shanti P; Kilts, Clint D; James, G Andrew

2017-08-14

Reciprocity is central to human relationships and is strongly influenced by multiple factors including the nature of social exchanges and their attendant emotional reactions. Despite recent advances in the field, the neural processes involved in this modulation of reciprocal behavior by ongoing social interaction are poorly understood. We hypothesized that activity within a discrete set of neural networks including a putative moral cognitive neural network is associated with reciprocity behavior. Nineteen healthy adults underwent functional magnetic resonance imaging scanning while playing the trustee role in the Trust Game. Personality traits and moral development were assessed. Independent component analysis was used to identify task-related functional brain networks and assess their relationship to behavior. The saliency network (insula and anterior cingulate) was positively correlated with reciprocity behavior. A consistent array of brain regions supports the engagement of emotional, self-referential and planning processes during social reciprocity behavior. Published by Elsevier B.V.

Realizing total reciprocity violation in the phase for photon scattering.

PubMed

Deák, László; Bottyán, László; Fülöp, Tamás; Merkel, Dániel Géza; Nagy, Dénes Lajos; Sajti, Szilárd; Schulze, Kai Sven; Spiering, Hartmut; Uschmann, Ingo; Wille, Hans-Christian

2017-02-22

Reciprocity is when wave or quantum scattering satisfies a symmetry property, connecting a scattering process with the reversed one. While reciprocity involves the interchange of source and detector, it is fundamentally different from rotational invariance, and is a generalization of time reversal invariance, occurring in absorptive media as well. Due to its presence at diverse areas of physics, it admits a wide variety of applications. For polarization dependent scatterings, reciprocity is often violated, but violation in the phase of the scattering amplitude is much harder to experimentally observe than violation in magnitude. Enabled by the advantageous properties of nuclear resonance scattering of synchrotron radiation, we have measured maximal, i.e., 180-degree, reciprocity violation in the phase. For accessing phase information, we introduced a new version of stroboscopic detection. The scattering setting was devised based on a generalized reciprocity theorem that opens the way to construct new types of reciprocity related devices.

77 FR 4663 - Final Revisions to Certain Data Collection and Reporting Requirements, Final Priority; State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-31

... into data reciprocity agreements with contiguous States or States with which it has tuition reciprocity... activities as: (1) Entering into data reciprocity agreements with private in-state IHEs that receive any... into data reciprocity agreements with private in-state IHEs over which the State exercises significant...

Familial Reciprocity and Subjective Well-Being in Ghana

ERIC Educational Resources Information Center

Tsai, Ming-Chang; Dzorgbo, Dan-Bright S.

2012-01-01

The authors investigated variations in reciprocity and the impact of reciprocity on well-being in a West African society. They hypothesized that household size and income diversity encourage reciprocity, which in turn enhances subjective well-being. In empirical testing of these hypotheses the authors used the data of the Core Welfare Indicators…

76 FR 2173 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... exchange. This proposed reciprocity is currently permitted with the Exchange's $1 Strike Program,\\4\\ $0.50... because the proposed reciprocity provision is similar to reciprocity provisions in place for other option..., with reciprocity provision). \\13\\ For purposes only of waiving the 30-day operative delay, the...

76 FR 82110 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-30

... Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines AGENCY: Federal Aviation...) for Thielert Aircraft Engines GmbH models TAE 125-02-99 and TAE 125-01 reciprocating engines. That AD... flight hours to within 600 flight hours for TAE 125-01 reciprocating engines. This AD was prompted by the...

14 CFR 121.181 - Airplanes: Reciprocating engine-powered: En route limitations: One engine inoperative.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airplanes: Reciprocating engine-powered: En... OPERATIONS Airplane Performance Operating Limitations § 121.181 Airplanes: Reciprocating engine-powered: En... person operating a reciprocating engine powered airplane may take off that airplane at a weight, allowing...

14 CFR 121.181 - Airplanes: Reciprocating engine-powered: En route limitations: One engine inoperative.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplanes: Reciprocating engine-powered: En... OPERATIONS Airplane Performance Operating Limitations § 121.181 Airplanes: Reciprocating engine-powered: En... person operating a reciprocating engine powered airplane may take off that airplane at a weight, allowing...

14 CFR 121.181 - Airplanes: Reciprocating engine-powered: En route limitations: One engine inoperative.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplanes: Reciprocating engine-powered: En... OPERATIONS Airplane Performance Operating Limitations § 121.181 Airplanes: Reciprocating engine-powered: En... person operating a reciprocating engine powered airplane may take off that airplane at a weight, allowing...

14 CFR 121.181 - Airplanes: Reciprocating engine-powered: En route limitations: One engine inoperative.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airplanes: Reciprocating engine-powered: En... OPERATIONS Airplane Performance Operating Limitations § 121.181 Airplanes: Reciprocating engine-powered: En... person operating a reciprocating engine powered airplane may take off that airplane at a weight, allowing...

14 CFR 121.181 - Airplanes: Reciprocating engine-powered: En route limitations: One engine inoperative.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplanes: Reciprocating engine-powered: En... OPERATIONS Airplane Performance Operating Limitations § 121.181 Airplanes: Reciprocating engine-powered: En... person operating a reciprocating engine powered airplane may take off that airplane at a weight, allowing...

Non-reciprocity in nonlinear elastodynamics

NASA Astrophysics Data System (ADS)

Blanchard, Antoine; Sapsis, Themistoklis P.; Vakakis, Alexander F.

2018-01-01

Reciprocity is a fundamental property of linear time-invariant (LTI) acoustic waveguides governed by self-adjoint operators with symmetric Green's functions. The break of reciprocity in LTI elastodynamics is only possible through the break of time reversal symmetry on the micro-level, and this can be achieved by imposing external biases, adding nonlinearities or allowing for time-varying system properties. We present a Volterra-series based asymptotic analysis for studying spatial non-reciprocity in a class of one-dimensional (1D), time-invariant elastic systems with weak stiffness nonlinearities. We show that nonlinearity is neither necessary nor sufficient for breaking reciprocity in this class of systems; rather, it depends on the boundary conditions, the symmetries of the governing linear and nonlinear operators, and the choice of the spatial points where the non-reciprocity criterion is tested. Extension of the analysis to higher dimensions and time-varying systems is straightforward from a mathematical point of view (but not in terms of new non-reciprocal physical phenomena), whereas the connection of non-reciprocity and time irreversibility can be studied as well. Finally, we show that suitably defined non-reciprocity measures enable optimization, and can provide physical understanding of the nonlinear effects in the dynamics, enabling one to establish regimes of "maximum nonlinearity." We highlight the theoretical developments by means of a numerical example.

Reciprocity explains food sharing in humans and other primates independent of kin selection and tolerated scrounging: a phylogenetic meta-analysis.

PubMed

Jaeggi, Adrian V; Gurven, Michael

2013-10-07

Helping, i.e. behaviour increasing the fitness of others, can evolve when directed towards kin or reciprocating partners. These predictions have been tested in the context of food sharing both in human foragers and non-human primates. Here, we performed quantitative meta-analyses on 32 independent study populations to (i) test for overall effects of reciprocity on food sharing while controlling for alternative explanations, methodological biases, publication bias and phylogeny and (ii) compare the relative effects of reciprocity, kinship and tolerated scrounging, i.e. sharing owing to costs imposed by others. We found a significant overall weighted effect size for reciprocity of r = 0.20-0.48 for the most and least conservative measure, respectively. Effect sizes did not differ between humans and other primates, although there were species differences in in-kind reciprocity and trade. The relative effect of reciprocity in sharing was similar to those of kinship and tolerated scrounging. These results indicate a significant independent contribution of reciprocity to human and primate helping behaviour. Furthermore, similar effect sizes in humans and primates speak against cognitive constraints on reciprocity. This study is the first to use meta-analyses to quantify these effects on human helping and to directly compare humans and other primates.

Reciprocity in therapeutic relationships: A conceptual review.

PubMed

Sandhu, Sima; Arcidiacono, Eleonora; Aguglia, Eugenio; Priebe, Stefan

2015-12-01

Reciprocity has generally been understood as a process of giving and taking, within an exchange of emotions or services, and has long been recognized as a central part of human life. However, an understanding of reciprocity in professional helping relationships has seldom received attention, despite movements in mental health care towards more collaborative approaches between service users and professionals. In this review, a systematic search of the published papers was conducted in order to explore how reciprocity is conceptualized and understood as part of the dyadic therapeutic relationship between professionals and service users. Eleven papers met our inclusion criteria and a narrative synthesis was used to synthesize the key concepts of reciprocity. The concepts of: 'dynamic equilibrium', 'shared affect', 'asymmetric alliance', and 'recognition as a fellow human being' were recurrent in understandings of reciprocity in professional contexts. These conceptualizations of reciprocity were also linked to specific behavioural and psychological processes. The findings suggest that reciprocity may be conceptualized and incorporated as a component of mental health care, with recurrent and observable processes which may be harnessed to promote positive outcomes for service users. To this end, we make recommendations for further research to progress and develop reciprocal processes in mental health care. © 2015 Australian College of Mental Health Nurses Inc.

Reciprocity explains food sharing in humans and other primates independent of kin selection and tolerated scrounging: a phylogenetic meta-analysis

PubMed Central

Jaeggi, Adrian V.; Gurven, Michael

2013-01-01

Helping, i.e. behaviour increasing the fitness of others, can evolve when directed towards kin or reciprocating partners. These predictions have been tested in the context of food sharing both in human foragers and non-human primates. Here, we performed quantitative meta-analyses on 32 independent study populations to (i) test for overall effects of reciprocity on food sharing while controlling for alternative explanations, methodological biases, publication bias and phylogeny and (ii) compare the relative effects of reciprocity, kinship and tolerated scrounging, i.e. sharing owing to costs imposed by others. We found a significant overall weighted effect size for reciprocity of r = 0.20–0.48 for the most and least conservative measure, respectively. Effect sizes did not differ between humans and other primates, although there were species differences in in-kind reciprocity and trade. The relative effect of reciprocity in sharing was similar to those of kinship and tolerated scrounging. These results indicate a significant independent contribution of reciprocity to human and primate helping behaviour. Furthermore, similar effect sizes in humans and primates speak against cognitive constraints on reciprocity. This study is the first to use meta-analyses to quantify these effects on human helping and to directly compare humans and other primates. PMID:23945693

Intrinsic rippling enhances static non-reciprocity in a graphene metamaterial.

PubMed

Ho, Duc Tam; Park, Harold S; Kim, Sung Youb

2018-01-18

In mechanical systems, Maxwell-Betti reciprocity means that the displacement at point B in response to a force at point A is the same as the displacement at point A in response to the same force applied at point B. Because the notion of reciprocity is general, fundamental, and is operant for other physical systems like electromagnetics, acoustics, and optics, there is significant interest in understanding systems that are not reciprocal, or exhibit non-reciprocity. However, most studies on non-reciprocity have occurred in bulk-scale structures for dynamic problems involving time reversal symmetry. As a result, little is known about the mechanisms governing static non-reciprocal responses, particularly in atomically-thin two-dimensional materials like graphene. Here, we use classical atomistic simulations to demonstrate that out-of-plane ripples, which are intrinsic to graphene, enable significant, multiple orders of magnitude enhancements in the statically non-reciprocal response of graphene metamaterials. Specifically, we find that a striking interplay between the ripples and the stress fields that are induced in the metamaterials due to their geometry impacts the displacements that are transmitted by the metamaterial, thus leading to a significantly enhanced static non-reciprocal response. This study thus demonstrates the potential of two-dimensional mechanical metamaterials for symmetry-breaking applications.

Parent-specific reciprocity from infancy to adolescence shapes children's social competence and dialogical skills.

PubMed

Feldman, Ruth; Bamberger, Esther; Kanat-Maymon, Yaniv

2013-01-01

Reciprocity - the capacity to engage in social exchange that integrates inputs from multiple partners into a unified social event - is a cornerstone of adaptive social life that is learned within dyad-specific attachments during an early period of neuroplasticity. Yet, very little research traced the expression of children's reciprocity with their mother and father in relation to long-term outcomes. Guided by evolutionary models, we followed mothers, fathers, and their firstborn child longitudinally and observed mother-child and father-child reciprocity in infancy, preschool, and adolescence. In preschool, children's social competence, aggression, and prosocial behavior were observed at kindergarten. In adolescence, children's dialogical skills were assessed during positive and conflict interactions with same-sex best friends. Father-child and mother-child reciprocity were individually stable, inter-related at each stage, and consisted of distinct behavioral components. Structural equation modeling indicated that early maternal and paternal reciprocity were each uniquely predictive of social competence and lower aggression in preschool, which, in turn, shaped dialogical skills in adolescence. Father-adolescent reciprocity contributed to the dialogical negotiation of conflict, whereas mother-adolescent reciprocity predicted adolescents' dialogical skills during positive exchanges. Results highlight the role of parent-child reciprocity in shaping children's social collaboration and intimate relationships with non-kin members of their social world.

Resistance to flexural fatigue of Reciproc R25 files under continuous rotation and reciprocating movement.

PubMed

Gavini, Giulio; Caldeira, Celso Luiz; Akisue, Eduardo; Candeiro, George Táccio de Miranda; Kawakami, Dirce Akemi Sacaguti

2012-05-01

The aim of the present work was to evaluate the resistance to flexural fatigue of Reciproc R25 nickel-titanium files, 25 mm, used in continuous rotation motion or reciprocation motion, in dynamic assays device. Thirty-six Reciproc R25 files were divided into 2 groups (n = 18) according to kinematics applied, continuous rotary (group CR) and reciprocation motion (group RM). The files were submitted to dynamic assays device moved by an electric engine with 300 rpm of speed that permitted the reproduction of pecking motion. The files run on a ring's groove of temperate steel, simulating instrumentation of a curved root canal with 40° and 5 mm of curvature radius. The fracture of file was detected by sensor of device, and the time was marked. The data were analyzed statistically by Student's t test, with level of significance of 95%. The instruments moved by reciprocating movement reached significantly higher numbers of cycles before fracture (mean, 1787.78 cycles) when compared with instruments moved by continuous rotary (mean, 816.39 cycles). The results showed that the reciprocation motion improves flexural fatigue resistance in nickel-titanium instrument Reciproc R25 when compared with continuous rotation movement. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Method and apparatus for optical encoding with compressible imaging

NASA Technical Reports Server (NTRS)

Leviton, Douglas B. (Inventor)

2006-01-01

The present invention presents an optical encoder with increased conversion rates. Improvement in the conversion rate is a result of combining changes in the pattern recognition encoder's scale pattern with an image sensor readout technique which takes full advantage of those changes, and lends itself to operation by modern, high-speed, ultra-compact microprocessors and digital signal processors (DSP) or field programmable gate array (FPGA) logic elements which can process encoder scale images at the highest speeds. Through these improvements, all three components of conversion time (reciprocal conversion rate)--namely exposure time, image readout time, and image processing time--are minimized.

A generalized graph-theoretical matrix of heterosystems and its application to the VMV procedure.

PubMed

Mozrzymas, Anna

2011-12-14

The extensions of generalized (molecular) graph-theoretical matrix and vector-matrix-vector procedure are considered. The elements of the generalized matrix are redefined in order to describe molecules containing heteroatoms and multiple bonds. The adjacency, distance, detour and reciprocal distance matrices of heterosystems, and corresponding vectors are derived from newly defined generalized graph matrix. The topological indices, which are most widely used in predicting physicochemical and biological properties/activities of various compounds, can be calculated from the new generalized vector-matrix-vector invariant. Copyright © 2011 Elsevier Ltd. All rights reserved.

Breathing of Graphite Particles in a Lithium-Ion Battery

NASA Astrophysics Data System (ADS)

Takata, Keiji; Okuda, Mitsuhiro; Yura, Nobuki; Tamura, Ryota

2012-04-01

We imaged changes in volume of graphite particles in a Li-ion battery due to the insertion and extraction of Li ions using scanning probe microscopy. When Li ions were extracted from the graphite particles, the particles were contracted, while expansion was induced in the interspaces between the particles. Variations of the images of volume changes depending on modulation frequencies clearly showed lithium intercalation. A linear relationship between the amplitudes of volume changes and the products of the diffusion elements and the reciprocals of the frequencies has been proven. Thus, the detected signals quantitatively well corresponded to the lithium ion movements.

Natural antisense RNAs as mRNA regulatory elements in bacteria: a review on function and applications.

PubMed

Saberi, Fatemeh; Kamali, Mehdi; Najafi, Ali; Yazdanparast, Alavieh; Moghaddam, Mehrdad Moosazadeh

2016-01-01

Naturally occurring antisense RNAs are small, diffusible, untranslated transcripts that pair to target RNAs at specific regions of complementarity to control their biological function by regulating gene expression at the post-transcriptional level. This review focuses on known cases of antisense RNA control in prokaryotes and provides an overview of some natural RNA-based mechanisms that bacteria use to modulate gene expression, such as mRNA sensors, riboswitches and antisense RNAs. We also highlight recent advances in RNA-based technology. The review shows that studies on both natural and synthetic systems are reciprocally beneficial.

Two distinct neural mechanisms underlying indirect reciprocity.

PubMed

Watanabe, Takamitsu; Takezawa, Masanori; Nakawake, Yo; Kunimatsu, Akira; Yamasue, Hidenori; Nakamura, Mitsuhiro; Miyashita, Yasushi; Masuda, Naoki

2014-03-18

Cooperation is a hallmark of human society. Humans often cooperate with strangers even if they will not meet each other again. This so-called indirect reciprocity enables large-scale cooperation among nonkin and can occur based on a reputation mechanism or as a succession of pay-it-forward behavior. Here, we provide the functional and anatomical neural evidence for two distinct mechanisms governing the two types of indirect reciprocity. Cooperation occurring as reputation-based reciprocity specifically recruited the precuneus, a region associated with self-centered cognition. During such cooperative behavior, the precuneus was functionally connected with the caudate, a region linking rewards to behavior. Furthermore, the precuneus of a cooperative subject had a strong resting-state functional connectivity (rsFC) with the caudate and a large gray matter volume. In contrast, pay-it-forward reciprocity recruited the anterior insula (AI), a brain region associated with affective empathy. The AI was functionally connected with the caudate during cooperation occurring as pay-it-forward reciprocity, and its gray matter volume and rsFC with the caudate predicted the tendency of such cooperation. The revealed difference is consistent with the existing results of evolutionary game theory: although reputation-based indirect reciprocity robustly evolves as a self-interested behavior in theory, pay-it-forward indirect reciprocity does not on its own. The present study provides neural mechanisms underlying indirect reciprocity and suggests that pay-it-forward reciprocity may not occur as myopic profit maximization but elicit emotional rewards.

Two distinct neural mechanisms underlying indirect reciprocity

PubMed Central

Watanabe, Takamitsu; Takezawa, Masanori; Nakawake, Yo; Kunimatsu, Akira; Yamasue, Hidenori; Nakamura, Mitsuhiro; Miyashita, Yasushi; Masuda, Naoki

2014-01-01

Cooperation is a hallmark of human society. Humans often cooperate with strangers even if they will not meet each other again. This so-called indirect reciprocity enables large-scale cooperation among nonkin and can occur based on a reputation mechanism or as a succession of pay-it-forward behavior. Here, we provide the functional and anatomical neural evidence for two distinct mechanisms governing the two types of indirect reciprocity. Cooperation occurring as reputation-based reciprocity specifically recruited the precuneus, a region associated with self-centered cognition. During such cooperative behavior, the precuneus was functionally connected with the caudate, a region linking rewards to behavior. Furthermore, the precuneus of a cooperative subject had a strong resting-state functional connectivity (rsFC) with the caudate and a large gray matter volume. In contrast, pay-it-forward reciprocity recruited the anterior insula (AI), a brain region associated with affective empathy. The AI was functionally connected with the caudate during cooperation occurring as pay-it-forward reciprocity, and its gray matter volume and rsFC with the caudate predicted the tendency of such cooperation. The revealed difference is consistent with the existing results of evolutionary game theory: although reputation-based indirect reciprocity robustly evolves as a self-interested behavior in theory, pay-it-forward indirect reciprocity does not on its own. The present study provides neural mechanisms underlying indirect reciprocity and suggests that pay-it-forward reciprocity may not occur as myopic profit maximization but elicit emotional rewards. PMID:24591599

Effect of direct reciprocity and network structure on continuing prosperity of social networking services.

PubMed

Osaka, Kengo; Toriumi, Fujio; Sugawara, Toshihauru

2017-01-01

Social networking services (SNSs) are widely used as communicative tools for a variety of purposes. SNSs rely on the users' individual activities associated with some cost and effort, and thus it is not known why users voluntarily continue to participate in SNSs. Because the structures of SNSs are similar to that of the public goods (PG) game, some studies have focused on why voluntary activities emerge as an optimal strategy by modifying the PG game. However, their models do not include direct reciprocity between users, even though reciprocity is a key mechanism that evolves and sustains cooperation in human society. We developed an abstract SNS model called the reciprocity rewards and meta-rewards games that include direct reciprocity by extending the existing models. Then, we investigated how direct reciprocity in an SNS facilitates cooperation that corresponds to participation in SNS by posting articles and comments and how the structure of the networks of users exerts an influence on the strategies of users using the reciprocity rewards game. We run reciprocity rewards games on various complex networks and an instance network of Facebook and found that two types of stable cooperation emerged. First, reciprocity slightly improves the rate of cooperation in complete graphs but the improvement is insignificant because of the instability of cooperation. However, this instability can be avoided by making two assumptions: high degree of fun, i.e. articles are read with high probability, and different attitudes to reciprocal and non-reciprocal agents. We then propose the concept of half free riders to explain what strategy sustains cooperation-dominant situations. Second, we indicate that a certain WS network structure affects users' optimal strategy and facilitates stable cooperation without any extra assumptions. We give a detailed analysis of the different characteristics of the two types of cooperation-dominant situations and the effect of the memory of reciprocal agents on cooperation.

The Mathematics of Sex and Marriage

DTIC Science & Technology

1972-01-01

the sense in which the one-sex problem is solved. A given and fixed set of birth and death rates , specific by age, say for females, determines the...and the second a weighted arithmetic mean of the given death rates ,UM and AF, the weights being the reciprocals of the birth rates. The... death rates . An example will suffice to present the problem and the proposed solution. Let us try to decide whether marriage among single persons 20 to

Optimal Periodic Control Theory.

DTIC Science & Technology

1980-08-01

single pair of complex eigenvalues are restricted to the unit circle in the complex plane . This is shown by first applying the reciprocity property to a...figure 6.2a and for H in figure 6.2b. Traversing the right half plot of figure 6.1a in a counter-clockwise direction, beginning at the origin...respectively. Only the lower half of the plots are shown because this region provides the solutions of most interest to the optimal periodic control problem

Control and postural thixotropy of the forearm muscles: changes caused by cold.

PubMed

Lakie, M; Walsh, E G; Wright, G W

1986-01-01

The forearm was cooled in water at 5-10 degrees C while wrist biodynamics were investigated. Pronounced loosening following a perturbation (thixotropy) was no longer seen. The wrist became stiffer for large or moderate but not small movements; EMG activity did not increase. Cooling the wrist alone, or opposite forearm, was without effect. The ability to make rapid reciprocating movements was reduced and muscle relaxation time was increased. Single movements were not affected.

Control and postural thixotropy of the forearm muscles: changes caused by cold.

PubMed Central

Lakie, M; Walsh, E G; Wright, G W

1986-01-01

The forearm was cooled in water at 5-10 degrees C while wrist biodynamics were investigated. Pronounced loosening following a perturbation (thixotropy) was no longer seen. The wrist became stiffer for large or moderate but not small movements; EMG activity did not increase. Cooling the wrist alone, or opposite forearm, was without effect. The ability to make rapid reciprocating movements was reduced and muscle relaxation time was increased. Single movements were not affected. PMID:3958734

Receive Mode Analysis and Design of Microstrip Reflectarrays

NASA Technical Reports Server (NTRS)

Rengarajan, Sembiam

2011-01-01

Traditionally microstrip or printed reflectarrays are designed using the transmit mode technique. In this method, the size of each printed element is chosen so as to provide the required value of the reflection phase such that a collimated beam results along a given direction. The reflection phase of each printed element is approximated using an infinite array model. The infinite array model is an excellent engineering approximation for a large microstrip array since the size or orientation of elements exhibits a slow spatial variation. In this model, the reflection phase from a given printed element is approximated by that of an infinite array of elements of the same size and orientation when illuminated by a local plane wave. Thus the reflection phase is a function of the size (or orientation) of the element, the elevation and azimuth angles of incidence of a local plane wave, and polarization. Typically, one computes the reflection phase of the infinite array as a function of several parameters such as size/orientation, elevation and azimuth angles of incidence, and in some cases for vertical and horizontal polarization. The design requires the selection of the size/orientation of the printed element to realize the required phase by interpolating or curve fitting all the computed data. This is a substantially complicated problem, especially in applications requiring a computationally intensive commercial code to determine the reflection phase. In dual polarization applications requiring rectangular patches, one needs to determine the reflection phase as a function of five parameters (dimensions of the rectangular patch, elevation and azimuth angles of incidence, and polarization). This is an extremely complex problem. The new method employs the reciprocity principle and reaction concept, two well-known concepts in electromagnetics to derive the receive mode analysis and design techniques. In the "receive mode design" technique, the reflection phase is computed for a plane wave incident on the reflectarray from the direction of the beam peak. In antenna applications with a single collimated beam, this method is extremely simple since all printed elements see the same angles of incidence. Thus the number of parameters is reduced by two when compared to the transmit mode design. The reflection phase computation as a function of five parameters in the rectangular patch array discussed previously is reduced to a computational problem with three parameters in the receive mode. Furthermore, if the beam peak is in the broadside direction, the receive mode design is polarization independent and the reflection phase computation is a function of two parameters only. For a square patch array, it is a function of the size, one parameter only, thus making it extremely simple.

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

Volker, Arno; Hunter, Alan

Anisotropic materials are being used increasingly in high performance industrial applications, particularly in the aeronautical and nuclear industries. Some important examples of these materials are composites, single-crystal and heavy-grained metals. Ultrasonic array imaging in these materials requires exact knowledge of the anisotropic material properties. Without this information, the images can be adversely affected, causing a reduction in defect detection and characterization performance. The imaging operation can be formulated in two consecutive and reciprocal focusing steps, i.e., focusing the sources and then focusing the receivers. Applying just one of these focusing steps yields an interesting intermediate domain. The resulting common focusmore » point gather (CFP-gather) can be interpreted to determine the propagation operator. After focusing the sources, the observed travel-time in the CFP-gather describes the propagation from the focus point to the receivers. If the correct propagation operator is used, the measured travel-times should be the same as the time-reversed focusing operator due to reciprocity. This makes it possible to iteratively update the focusing operator using the data only and allows the material to be imaged without explicit knowledge of the anisotropic material parameters. Furthermore, the determined propagation operator can also be used to invert for the anisotropic medium parameters. This paper details the proposed technique and demonstrates its use on simulated array data from a specimen of Inconel single-crystal alloy commonly used in the aeronautical and nuclear industries.« less

The self-adjusting file instrumentation results in less debris extrusion apically when compared to WaveOne and ProTaper NEXT

PubMed Central

Pawar, Ajinkya M.; Pawar, Mansing G.; Metzger, Zvi; Kokate, Sharad R.

2015-01-01

Aim: The present ex vivo study aimed to evaluate the debris extrusion after instrumenting the root canals by three different files systems. Materials and Methods: Sixty extracted human mandibular premolars with single canals were selected and randomly divided into three groups (n = 20) for instrumentation with three different files. Group 1: WaveOne (primary) single reciprocating file (WO; Dentsply Maillefer, Ballaigues, Switzerland) (25/08), Group 2: Self-adjusting file (SAF; ReDent-Nova, Ra’anana, Israel) (1.5 mm), and Group 3: ProTaper NEXT X1 and X2 (PTN; Dentsply Tulsa Dental, Tulsa, OK) (25/06). Debris extruding by instrumentation were collected into pre-weighed Eppendorf tubes. These tubes were then stored in an incubator at 70°C for 5 days. The tubes were then weighed to obtain the final weight, with the extruded debris. Statistical analysis for the debris extruded apically was performed using one-way analysis of variance and post hoc Tukey's test. Results: The statistical analysis showed a significant difference between all the three groups tested (P < 0.01). The following post hoc Tukey's test confirmed that Group 2 (SAF) exhibited significantly least (P < 0.01) debris extrusion between the three groups tested. Conclusions: The SAF resulted in significantly less extrusion of debris when compared to reciprocating WO and rotary PTN. PMID:25829683

Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector

DOEpatents

Strauss, Charlie E.

1997-01-01

Apparatus and method for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO.sub.2 laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart.

Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector

DOEpatents

Strauss, C.E.

1997-11-18

Apparatus and method are disclosed for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO{sub 2} laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart. 4 figs.

76 FR 2187 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing and Immediate Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... reciprocity currently is permitted with the Exchange's $1 Strike Program, $.50 Strike Program and $2.50 Strike... interest because the proposed reciprocity provision is similar to reciprocity provisions in place for other... reciprocity provision). \\11\\ For purposes only of waiving the 30-day operative delay, the Commission has...

Short-Term Reciprocity in Late Parent-Child Relationships

ERIC Educational Resources Information Center

Leopold, Thomas; Raab, Marcel

2011-01-01

Long-term concepts of parent-child reciprocity assume that the amount of support given and received is only balanced in a generalized fashion over the life course. We argue that reciprocity in parent-child relationships also operates in the short term. Our analysis of short-term reciprocity focuses on concurrent exchange in its main upward and…

Reciprocity in directed networks

NASA Astrophysics Data System (ADS)

Yin, Mei; Zhu, Lingjiong

2016-04-01

Reciprocity is an important characteristic of directed networks and has been widely used in the modeling of World Wide Web, email, social, and other complex networks. In this paper, we take a statistical physics point of view and study the limiting entropy and free energy densities from the microcanonical ensemble, the canonical ensemble, and the grand canonical ensemble whose sufficient statistics are given by edge and reciprocal densities. The sparse case is also studied for the grand canonical ensemble. Extensions to more general reciprocal models including reciprocal triangle and star densities will likewise be discussed.

Local Burn-Up Effects in the NBSR Fuel Element

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

Brown N. R.; Hanson A.; Diamond, D.

2013-01-31

This study addresses the over-prediction of local power when the burn-up distribution in each half-element of the NBSR is assumed to be uniform. A single-element model was utilized to quantify the impact of axial and plate-wise burn-up on the power distribution within the NBSR fuel elements for both high-enriched uranium (HEU) and low-enriched uranium (LEU) fuel. To validate this approach, key parameters in the single-element model were compared to parameters from an equilibrium core model, including neutron energy spectrum, power distribution, and integral U-235 vector. The power distribution changes significantly when incorporating local burn-up effects and has lower power peakingmore » relative to the uniform burn-up case. In the uniform burn-up case, the axial relative power peaking is over-predicted by as much as 59% in the HEU single-element and 46% in the LEU single-element with uniform burn-up. In the uniform burn-up case, the plate-wise power peaking is over-predicted by as much as 23% in the HEU single-element and 18% in the LEU single-element. The degree of over-prediction increases as a function of burn-up cycle, with the greatest over-prediction at the end of Cycle 8. The thermal flux peak is always in the mid-plane gap; this causes the local cumulative burn-up near the mid-plane gap to be significantly higher than the fuel element average. Uniform burn-up distribution throughout a half-element also causes a bias in fuel element reactivity worth, due primarily to the neutronic importance of the fissile inventory in the mid-plane gap region.« less

Single cell versus large population analysis: cell variability in elemental intracellular concentration and distribution.

PubMed

Malucelli, Emil; Procopio, Alessandra; Fratini, Michela; Gianoncelli, Alessandra; Notargiacomo, Andrea; Merolle, Lucia; Sargenti, Azzurra; Castiglioni, Sara; Cappadone, Concettina; Farruggia, Giovanna; Lombardo, Marco; Lagomarsino, Stefano; Maier, Jeanette A; Iotti, Stefano

2018-01-01

The quantification of elemental concentration in cells is usually performed by analytical assays on large populations missing peculiar but important rare cells. The present article aims at comparing the elemental quantification in single cells and cell population in three different cell types using a new approach for single cells elemental analysis performed at sub-micrometer scale combining X-ray fluorescence microscopy and atomic force microscopy. The attention is focused on the light element Mg, exploiting the opportunity to compare the single cell quantification to the cell population analysis carried out by a highly Mg-selective fluorescent chemosensor. The results show that the single cell analysis reveals the same Mg differences found in large population of the different cell strains studied. However, in one of the cell strains, single cell analysis reveals two cells with an exceptionally high intracellular Mg content compared with the other cells of the same strain. The single cell analysis allows mapping Mg and other light elements in whole cells at sub-micrometer scale. A detailed intensity correlation analysis on the two cells with the highest Mg content reveals that Mg subcellular localization correlates with oxygen in a different fashion with respect the other sister cells of the same strain. Graphical abstract Single cells or large population analysis this is the question!

Reciprocal inhibition between miR-26a and NF-κB regulates obesity-related chronic inflammation in chondrocytes.

PubMed

Xie, Qingyun; Wei, Meng; Kang, Xia; Liu, Da; Quan, Yi; Pan, Xianming; Liu, Xiling; Liao, Dongfa; Liu, Jinbiao; Zhang, Bo

2015-04-25

Obesity is causally linked to osteoarthritis (OA), with the mechanism being not fully elucidated. miRNAs (miRs) are pivotal regulators of various diseases in multiple tissues, including inflammation in the chondrocytes. In the present study, we for the first time identified the expression of miR-26a in mouse chondrocytes. Decreased level of miR-26a was correlated to increased chronic inflammation in the chondrocytes and circulation in obese mouse model. Mechanistically, we demonstrated that miR-26a attenuated saturated free fatty acid-induced activation of NF-κB (p65) and production of proinflammatory cytokines in chondrocytes. Meanwhile, NF-κB (p65) also suppressed miR-26a production by directly binding to a predicted NF-κB binding element in the promoter region of miR-26a. Finally, we observed a negative correlation between NF-κB and miR-26a in human patients with osteoarthritis. Thus, we identified a reciprocal inhibition between miR-26a and NF-κB downstream of non-esterified fatty acid (NEFA) signalling in obesity-related chondrocytes. Our findings provide a potential mechanism linking obesity to cartilage inflammation. © 2015 Authors.

Kinematic Effects of Nickel-Titanium Instruments with Reciprocating or Continuous Rotation Motion: A Systematic Review of In Vitro Studies.

PubMed

Ahn, So-Yeon; Kim, Hyeon-Cheol; Kim, Euiseong

2016-07-01

This review aimed to compare the kinematic effect of nickel-titanium instruments with reciprocating and continuous rotation motion for cyclic fatigue resistance, shaping ability, apical debris extrusion, and dentinal defects or cracks. Articles were selected for inclusion in this review if they fulfilled all of the following criteria: described in vitro studies performed on either extracted human teeth or an artificial canal model, assessed both reciprocating and rotary instruments, compared reciprocating files and rotary files for the kinematics of files, and evaluated reciprocating and rotary files regarding the aim of this study. The electronic search was undertaken in MEDLINE, Cochrane database, and manual searches, including journals, reference lists, and other reviews. Twelve studies were chosen for cyclic fatigue, 19 studies for shaping ability, 14 studies for apical debris extrusion, and 13 studies for dentinal defects or cracks. Most of the studies showed that reciprocating motion had a higher resistance to cyclic fatigue. Nine studies from the shaping studies reported less canal transportation by using the reciprocating motion than the continuous rotation. The reciprocating instruments tended to extrude more dentin debris than the continuous rotating instruments, but many of the studies showed conflicting results. In addition, 2 studies from the defects or cracks studies claimed the reciprocating motion produced more dentinal defects than the continuous rotating motion. Instruments with reciprocating motion seemed to have better resistance to cyclic fatigue with less canal transportation tendency than the instruments with continuous rotating motion. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Participation costs can suppress the evolution of upstream reciprocity.

PubMed

Peña, Jorge; Pestelacci, Enea; Berchtold, André; Tomassini, Marco

2011-03-21

Indirect reciprocity, one of the many mechanisms proposed to explain the evolution of cooperation, is the idea that altruistic actions can be rewarded by third parties. Upstream or generalized reciprocity is one type of indirect reciprocity in which individuals help someone if they have been helped by somebody else in the past. Although empirically found to be at work in humans, the evolution of upstream reciprocity is difficult to explain from a theoretical point of view. A recent model of upstream reciprocity, first proposed by Nowak and Roch (2007) and further analyzed by Iwagami and Masuda (2010), shows that while upstream reciprocity alone does not lead to the evolution of cooperation, it can act in tandem with mechanisms such as network reciprocity and increase the total level of cooperativity in the population. We argue, however, that Nowak and Roch's model systematically leads to non-uniform interaction rates, where more cooperative individuals take part in more games than less cooperative ones. As a result, the critical benefit-to-cost ratios derived under this model in previous studies are not invariant with respect to the addition of participation costs. We show that accounting for these costs can hinder and even suppress the evolution of upstream reciprocity, both for populations with non-random encounters and graph-structured populations. Copyright © 2011 Elsevier Ltd. All rights reserved.

On use of CO{sub 2} chemiluminescence for combustion metrics in natural gas fired reciprocating engines.

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

Gupta, S. B.; Bihari, B.; Biruduganti, M.

Flame chemiluminescence is widely acknowledged to be an indicator of heat release rate in premixed turbulent flames that are representative of gas turbine combustion. Though heat release rate is an important metric for evaluating combustion strategies in reciprocating engine systems, its correlation with flame chemiluminescence is not well studied. To address this gap an experimental study was carried out in a single-cylinder natural gas fired reciprocating engine that could simulate turbocharged conditions with exhaust gas recirculation. Crank angle resolved spectra (266-795 nm) of flame luminosity were measured for various operational conditions by varying the ignition timing for MBT conditions andmore » by holding the speed at 1800 rpm and Brake Mean effective Pressure (BMEP) at 12 bar. The effect of dilution on CO*{sub 2}chemiluminescence intensities was studied, by varying the global equivalence ratio (0.6-1.0) and by varying the exhaust gas recirculation rate. It was attempted to relate the measured chemiluminescence intensities to thermodynamic metrics of importance to engine research -- in-cylinder bulk gas temperature and heat release rate (HRR) calculated from measured cylinder pressure signals. The peak of the measured CO*{sub 2} chemiluminescence intensities coincided with peak pressures within {+-}2 CAD for all test conditions. For each combustion cycle, the peaks of heat release rate, spectral intensity and temperature occurred in that sequence, well separated temporally. The peak heat release rates preceded the peak chemiluminescent emissions by 3.8-9.5 CAD, whereas the peak temperatures trailed by 5.8-15.6 CAD. Such a temporal separation precludes correlations on a crank-angle resolved basis. However, the peak cycle heat release rates and to a lesser extent the peak cycle temperatures correlated well with the chemiluminescent emission from CO*{sub 2}. Such observations point towards the potential use of flame chemiluminescence to monitor peak bulk gas temperatures as well as peak heat release rates in natural gas fired reciprocating engines.« less

Cyclic fatigue resistance of new reciprocating files (Reciproc Blue, WaveOne Gold, and SmartTrack) in two different curved canals.

PubMed

Topçuoğlu, Hüseyin Sinan; Demirbuga, Sezer; Düzgün, Salih; Topçuoğlu, Gamze

2018-06-04

In the present study, we compared the cyclic fatigue resistance (CFR) of Reciproc Blue, WaveOne Gold, and SmartTrack files in curved artificial canals. Ninety new Reciproc Blue R25, WaveOne Gold Primary, and SmartTrack X1 files were tested in artificial canals with 45° and 60° angles of curvature. CFR was determined by recording the time to fracture in the artificial canals. Two-way analysis of variance was used to analyze the data. In the canal with a 45° angle of curvature, no significant differences were observed amongst Reciproc Blue, WaveOne Gold, and SmartTrack (P > .05). In the canal with a 60° angle of curvature, Reciproc Blue and SmartTrack had a greater CFR than WaveOne Gold (P < .05); there was no significant difference between the Reciproc Blue and SmartTrack files (P > .05). The results of the present study showed that Reciproc Blue and SmartTrack files exhibited greater CFR than WaveOne Gold only in canals with a 60° angle of curvature. © 2018 John Wiley & Sons Australia, Ltd.

The Role of Friendship Reciprocity in University Freshmen's Alcohol Consumption.

PubMed

Giese, Helge; Stok, F Marijn; Renner, Britta

2017-07-01

The similarity of friends in the frequency and quantity of alcohol consumption is explored. During their first semester, 57 psychology freshmen indicated weekly drinking frequency and quantity and nominated the three peers of this group they liked most. These nominations were then used to derive the weekly alcohol consumption of friends that either did or did not reciprocate a nomination. Multilevel modeling of weekly variations showed that individuals' drinking frequency was similar to peers who reciprocated a friendship (b = 0.15, p = .001), but not to non-reciprocating peers (b = -0.01, p = .720). In contrast, weekly variation in quantity of individual students' drinking was similar to both reciprocating (b = 0.11, p = .018) and non-reciprocating peers' drinking (b = 0.10, p = .014). Yet across all weeks, quantity tended only to be similar to non-reciprocating peers (b = 0.49, p = .020). Freshmen might spend drinking time with peers who reciprocate a friendship, but are similar regarding the quantity of drinks consumed to all people they find interesting. Thus, alcohol consumption is used strategically for social purposes. This social purpose should also be acknowledged in alcohol-reduction interventions. © 2017 The International Association of Applied Psychology.

Trust and Reciprocity: Are Effort and Money Equivalent?

PubMed Central

Vilares, Iris; Dam, Gregory; Kording, Konrad

2011-01-01

Trust and reciprocity facilitate cooperation and are relevant to virtually all human interactions. They are typically studied using trust games: one subject gives (entrusts) money to another subject, which may return some of the proceeds (reciprocate). Currently, however, it is unclear whether trust and reciprocity in monetary transactions are similar in other settings, such as physical effort. Trust and reciprocity of physical effort are important as many everyday decisions imply an exchange of physical effort, and such exchange is central to labor relations. Here we studied a trust game based on physical effort and compared the results with those of a computationally equivalent monetary trust game. We found no significant difference between effort and money conditions in both the amount trusted and the quantity reciprocated. Moreover, there is a high positive correlation in subjects' behavior across conditions. This suggests that trust and reciprocity may be character traits: subjects that are trustful/trustworthy in monetary settings behave similarly during exchanges of physical effort. Our results validate the use of trust games to study exchanges in physical effort and to characterize inter-subject differences in trust and reciprocity, and also suggest a new behavioral paradigm to study these differences. PMID:21364931

Effect of processing conditions on quality of green beans subjected to reciprocating agitation thermal processing.

PubMed

Singh, Anika; Singh, Anubhav Pratap; Ramaswamy, Hosahalli S

2015-12-01

The effect of reciprocating agitation thermal processing (RA-TP) on quality of canned beans was evaluated in a lab-scale reciprocating retort. Green beans were selected due to their soft texture and sensitive color. Green beans (2.5cm length×0.8cm diameter) were filled into 307×409 cans with carboxylmethylcellulose (0-2%) solutions and processed at different temperatures (110-130°C) and reciprocation frequency (1-3Hz) for predetermined heating times to achieve a process lethality (F o ) of 10min. Products processed at higher temperatures and higher reciprocation frequencies resulted in better retention of chlorophyll and antioxidant activity. However, high reciprocation frequency also resulted in texture losses, with higher breakage of beans, increased turbidity and higher leaching. There was total loss of product quality at the highest agitation speed, especially with low viscosity covering solutions. Results suggest that reciprocating agitation frequency needs to be adequately moderated to get the best quality. For getting best quality, particularly for canned liquid particulate foods with soft particulates and those susceptible to high impact agitation, a gentle reciprocating motion (~1Hz) would be a good compromise. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reciprocity of agonistic support in ravens.

PubMed

Fraser, Orlaith N; Bugnyar, Thomas

2012-01-01

Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim's likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals.

The calibration of photographic and spectroscopic films. Part 1: Film batch variations of reciprocity failure in IIaO film. Part 2: Thermal and aging effects in relationship to reciprocity failure. P art 3: Shifting of reciprocity failure points as a function of thermal and aging effects

NASA Technical Reports Server (NTRS)

Peters, Kevin A.; Atkinson, Pamela F.; Hammond, Ernest C., Jr

1987-01-01

Reciprocity failure was examined for IIaO spectroscopic film. Three separate experiments were performed in order to study film batch variations, thermal and aging effects in relationship to reciprocity failure, and shifting of reciprocity failure points as a function of thermal and aging effects. The failure was examined over ranges of time between 5 and 60 seconds. The variation to illuminance was obtained by using thirty neutral density filters. A standard sensitometer device imprinted the wedge pattern on the film as exposure time was subjected to variation. Results indicate that film batch differences, temperature, and aging play an important role in reciprocity failure of IIaO spectroscopic film. A shifting of the failure points was also observed in various batches of film.

A coupled mode formulation by reciprocity and a variational principle

NASA Technical Reports Server (NTRS)

Chuang, Shun-Lien

1987-01-01

A coupled mode formulation for parallel dielectric waveguides is presented via two methods: a reciprocity theorem and a variational principle. In the first method, a generalized reciprocity relation for two sets of field solutions satisfying Maxwell's equations and the boundary conditions in two different media, respectively, is derived. Based on the generalized reciprocity theorem, the coupled mode equations can then be formulated. The second method using a variational principle is also presented for a general waveguide system which can be lossy. The results of the variational principle can also be shown to be identical to those from the reciprocity theorem. The exact relations governing the 'conventional' and the new coupling coefficients are derived. It is shown analytically that the present formulation satisfies the reciprocity theorem and power conservation exactly, while the conventional theory violates the power conservation and reciprocity theorem by as much as 55 percent and the Hardy-Streifer (1985, 1986) theory by 0.033 percent, for example.

Influence of reciprocal edges on degree distribution and degree correlations

NASA Astrophysics Data System (ADS)

Zlatić, Vinko; Štefančić, Hrvoje

2009-07-01

Reciprocal edges represent the lowest-order cycle possible to find in directed graphs without self-loops. Representing also a measure of feedback between vertices, it is interesting to understand how reciprocal edges influence other properties of complex networks. In this paper, we focus on the influence of reciprocal edges on vertex degree distribution and degree correlations. We show that there is a fundamental difference between properties observed on the static network compared to the properties of networks, which are obtained by simple evolution mechanism driven by reciprocity. We also present a way to statistically infer the portion of reciprocal edges, which can be explained as a consequence of feedback process on the static network. In the rest of the paper, the influence of reciprocal edges on a model of growing network is also presented. It is shown that our model of growing network nicely interpolates between Barabási-Albert (BA) model for undirected and the BA model for directed networks.

Reciprocal feedback regulation of PI3K and androgen receptor signaling in PTEN-deficient prostate cancer

PubMed Central

Carver, Brett S; Chapinski, Caren; Wongvipat, John; Hieronymus, Haley; Chen, Yu; Chandarlapaty, Sarat; Arora, Vivek K; Le, Carl; Koutcher, Jason; Scher, Howard; Scardino, Peter T; Rosen, Neal; Sawyers, Charles L

2011-01-01

Summary Prostate cancer is characterized by its dependence on androgen receptor and frequent activation of PI3K signaling. We find that AR transcriptional output is decreased in human and murine tumors with PTEN deletion and that PI3K pathway inhibition activates AR signaling by relieving feedback inhibition of HER kinases. Similarly, AR inhibition activates AKT signaling by reducing levels of the AKT phosphatase PHLPP. Thus, these two oncogenic pathways cross-regulate each other by reciprocal feedback. Inhibition of one activates the other, thereby maintaining tumor cell survival. However, combined pharmacologic inhibition of PI3K and AR signaling caused near complete prostate cancer regressions in a Pten-deficient murine prostate cancer model and in human prostate cancer xenografts, indicating that both pathways coordinately support survival. Significance The two most frequently activated signaling pathways in prostate cancer are driven by AR and PI3K. Inhibitors of the PI3K pathway are in early clinical trials and AR inhibitors confer clinical responses in most patients. However, these inhibitors rarely induce tumor regression in preclinical models. Here we show that these pathways regulate each other by reciprocal negative feedback, such that inhibition of one activates the other. Therefore, tumor cells can adapt and survive when either single pathway is inhibited pharmacologically. Our demonstration of profound tumor regressions with combined pathway inhibition in preclinical prostate tumor models provides rationale for combination therapy in patients. PMID:21575859

Design and evaluation of a grid reciprocation scheme for use in digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Patel, Tushita; Sporkin, Helen; Peppard, Heather; Williams, Mark B.

2016-03-01

This work describes a methodology for efficient removal of scatter radiation during digital breast tomosynthesis (DBT). The goal of this approach is to enable grid image obscuration without a large increase in radiation dose by minimizing misalignment of the grid focal point (GFP) and x-ray focal spot (XFS) during grid reciprocation. Hardware for the motion scheme was built and tested on the dual modality breast tomosynthesis (DMT) scanner, which combines DBT and molecular breast tomosynthesis (MBT) on a single gantry. The DMT scanner uses fully isocentric rotation of tube and x-ray detector for maintaining a fixed tube-detector alignment during DBT imaging. A cellular focused copper prototype grid with 80 cm focal length, 3.85 mm height, 0.1 mm thick lamellae, and 1.1 mm hole pitch was tested. Primary transmission of the grid at 28 kV tube voltage was on average 74% with the grid stationary and aligned for maximum transmission. It fell to 72% during grid reciprocation by the proposed method. Residual grid line artifacts (GLAs) in projection views and reconstructed DBT images are characterized and methods for reducing the visibility of GLAs in the reconstructed volume through projection image flat-field correction and spatial frequency-based filtering of the DBT slices are described and evaluated. The software correction methods reduce the visibility of these artifacts in the reconstructed volume, making them imperceptible both in the reconstructed DBT images and their Fourier transforms.

Reciprocity Outperforms Conformity to Promote Cooperation.

PubMed

Romano, Angelo; Balliet, Daniel

2017-10-01

Evolutionary psychologists have proposed two processes that could give rise to the pervasiveness of human cooperation observed among individuals who are not genetically related: reciprocity and conformity. We tested whether reciprocity outperformed conformity in promoting cooperation, especially when these psychological processes would promote a different cooperative or noncooperative response. To do so, across three studies, we observed participants' cooperation with a partner after learning (a) that their partner had behaved cooperatively (or not) on several previous trials and (b) that their group members had behaved cooperatively (or not) on several previous trials with that same partner. Although we found that people both reciprocate and conform, reciprocity has a stronger influence on cooperation. Moreover, we found that conformity can be partly explained by a concern about one's reputation-a finding that supports a reciprocity framework.

A literature review on the mutual impact of the spousal caregiver-cancer patients dyads: 'communication', 'reciprocal influence', and 'caregiver-patient congruence'.

PubMed

Li, Qiuping; Loke, Alice Yuen

2014-02-01

A diagnosis of cancer is the start of a journey of distress and adjustment for both the patient and his/her spouse. However, the dyadic phenomena are less conceptualised and related research is in the early stages. This review explores concepts of mutuality among spousal caregiver-cancer patient dyads and identifies directions for future research. A systematic search, including trawling through six electronic databases, a manual search, and an author search, was conducted to identity articles that had been published in English and Chinese from January 2000 to March 2013, using key terms related to caregiver-patients dyads in cancer care. An inductive content analysis approach was adopted to analyse and synthesise the concepts of spousal caregiver-cancer patient dyads. Thirty-one articles were identified. The findings are described according to Fletcher et al.'s proposals for conceptualising spousal caregiver-patient dyads. The proposed concepts of 'communication', 'reciprocal influence', and 'caregiver-patient congruence' have been found to be interrelated, and to contribute to the spousal caregiver-patient dyads' mutual appraisal of caregiving and role adjustment through the cancer trajectory. The findings highlight the importance of a perspective that focuses on the nature of the relationship between couples coping with cancer and the quality of their communication with each other. It is recognised that communication may act as a fundamental element of the abovementioned three concepts. Better communication between couples would probably facilitate reciprocal influence and caregiver-patient congruence, which in turn would have a positive effect on intimacy between the couple and improve the caregiving outcomes. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Electromagnetic characterization of photo-definable ferrite loaded polymers and their applications in micro-rectangular coaxial phase shifters

NASA Astrophysics Data System (ADS)

Sholiyi, Olusegun Samuel

As the demand for smaller size, lighter weight, lower loss and cost of communications transmit and receive (T/R) modules increases, there is an urgent need to focus investigation to the major subsystem or components that can improve these parameters. Phase shifters contribute greatly to the cost of T/R modules, and thus this research investigation examines a new way to reduce the weight and cost by miniaturizing the phaser design. Characterization of hexaferrite powders compatible with the sequential multilayer micro-fabrication technology and numerical simulations of a novel rectangular micro-coaxial phase shifter are investigated. This effort aims to integrate ferrite material into a rectangular micro-coaxial waveguide at Ka-band using electromagnetic finite element numerical tools. The proposed technique exploits rectangular coaxial waveguide with a symmetrically placed inner signal conductor inside an outer conductor connected to the ground. Strontium ferrite-SU8 composite is used as an anisotropic material of choice in the modelled design. Numerical modeling is employed using High Frequency Structure Simulator, HFSS, a 3-D full wave electromagnetic solver for analyzing the performance of the device. Two model structures were designed for reciprocal and non-reciprocal applications. The first model (Model A) produced a tunable phase shift of almost 60 degrees /cm across 0 to 400 kA/m applied field and at 1800 Gauss. In model B, a non-reciprocal phase shift performance of 20 degrees /cm from a reference phase of 24 degrees at 0 A/m was realized at the same saturation magnetization. A return loss better than 20 dB and an insertion loss less than 1.5 dB were obtained for both models.

Effectiveness of ProTaper Universal retreatment instruments used with rotary or reciprocating adaptive motion in the removal of root canal filling material.

PubMed

Capar, I D; Arslan, H; Ertas, H; Gök, T; Saygılı, G

2015-01-01

To compare the effectiveness of ProTaper Universal retreatment instruments with continuous rotation and adaptive motion (AM; a modified reciprocating motion that combines rotational and reciprocating motion) in the removal of filling material. Mesiobuccal root canals in 36 mandibular first molars were instrumented up to size F2 with the ProTaper Universal instrument (Dentsply Maillefer, Ballaigues, Switzerland) and filled using sealer and ProTaper Universal F2 gutta-percha cones. Gutta-percha was then down-packed and the root canal backfilled using the extruder hand-piece of the Elements Obturation System (SybronEndo, Orange, CA, USA). The teeth were assigned to two groups (n = 18), and removal of the root fillings was performed using one of the following techniques: group 1) ProTaper Universal retreatment files used with rotational motion (RM) and group 2) ProTaper Universal retreatment files used with adaptive motion (AM) (600° clockwise/0° counter-clockwise to 370° clockwise/50° counter-clockwise). The teeth were sectioned, and both halves were analysed at 8 × magnification. The percentage of remaining filling material was recorded. The data were analysed statistically using the Student's t-test at a 95% confidence level (P < 0.05). There was no significant difference between the groups with respect to the total time required for retreatment (P = 0.481). The AM technique left significantly less filling material than the RM method (P = 0.013). The use of ProTaper Universal retreatment files with adaptive motion removed more filling materials from root canals than the rotational movement. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A hierarchical generalization of the acoustic reciprocity theorem involving higher-order derivatives and interaction quantities.

PubMed

Lin, Ju; Li, Jie; Li, Xiaolei; Wang, Ning

2016-10-01

An acoustic reciprocity theorem is generalized, for a smoothly varying perturbed medium, to a hierarchy of reciprocity theorems including higher-order derivatives of acoustic fields. The standard reciprocity theorem is the first member of the hierarchy. It is shown that the conservation of higher-order interaction quantities is related closely to higher-order derivative distributions of perturbed media. Then integral reciprocity theorems are obtained by applying Gauss's divergence theorem, which give explicit integral representations connecting higher-order interactions and higher-order derivative distributions of perturbed media. Some possible applications to an inverse problem are also discussed.

Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance

PubMed Central

Horn, Bruce W.; Gell, Richard M.; Singh, Rakhi; Sorensen, Ronald B.; Carbone, Ignazio

2016-01-01

Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing. PMID:26731416

Bacterial Reduction after Gutta-Percha Removal with Single vs. Multiple Instrument Systems.

PubMed

Xavier, Felipe; Nevares, Giselle; Gominho, Luciana; Rodrigues, Renata; Cassimiro, Marcely; Romeiro, Kaline; Albuquerque, Diana

2018-01-01

The aim of this study was to evaluate the effectiveness of a reciprocating single-instrument system (Reciproc-REC) compared with combined continuously rotating multiple-instrument systems [D-Race (DR) and BioRace (BR)] in reducing Enterococcus faecalis (E.f.) after gutta-percha removal. Forty-six extracted human maxillary incisors were prepared and contaminated with E.f. strain (ATCC 29212) for 30 days. The samples were obturated and randomly divided into two experimental groups for gutta-percha removal ( n =23): a REC group (R50) and a DR/BR group (DR1, DR2 and BR6). A standardized irrigation with 0.9% saline solution was performed. Root canal samples were taken with paper points before (S1) and after (S2) the removal of gutta-percha to establish bacterial quantification by culture. The time required for gutta-percha removal was also recorded. Positive and negative control groups ( n =6) were used to test bacterial viability and control asepsis, respectively. Data were analysed using t -Student and one-way ANOVA tests (5% margin of error). The mean percentage of bacterial reduction was significantly higher in DR/BR group (84.2%) than in REC group (72.3%) ( P <0.05). The mean time for obturation removal was 74.00 sec in REC group and 107.53 sec in DR/BR group ( P <0.05). The combined continuously rotating multiple-instrument system was more effective in reducing bacteria after the removal of gutta-percha than the single-instrument system. None of the tested systems was able to completely eliminate root canal infection after gutta-percha removal. Thus, additional techniques should be considered.

Series of Reciprocal Triangular Numbers

ERIC Educational Resources Information Center

Bruckman, Paul; Dence, Joseph B.; Dence, Thomas P.; Young, Justin

2013-01-01

Reciprocal triangular numbers have appeared in series since the very first infinite series were summed. Here we attack a number of subseries of the reciprocal triangular numbers by methodically expressing them as integrals.

Effect of sodium hypochlorite and saline on cyclic fatigue resistance of WaveOne Gold and Reciproc reciprocating instruments.

PubMed

Elnaghy, A M; Elsaka, S E

2017-10-01

To compare the cyclic fatigue resistance of WaveOne Gold (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA) and Reciproc (VDW, Munich, Germany) reciprocating instruments during immersion in sodium hypochlorite (NaOCl) and saline solutions at body temperature. A total of 180 new WaveOne Gold primary size 25, .07 taper, and Reciproc size 25, .08 taper were randomly divided into three groups: group 1: no immersion (control, air); group 2: immersion in saline at 37 ± 1 °C; and group 3: immersion in 5% NaOCl at 37 ± 1 °C. The instruments were reciprocated in the test solution until fracture, and the number of cycles to failure was recorded. The data were analysed statistically using t-tests and one-way analysis of variance (anova) with the significance level set at P < 0.05. A Weibull analysis was performed on number of cycles to failure data. WaveOne Gold instruments had significantly greater number of cycles to failure than Reciproc instruments in all groups (P < 0.001). Fatigue resistance for both instruments tested in air was significantly higher than that in saline and NaOCl solutions (P < 0.001). For both instruments, there was no significant difference in the fatigue resistance between saline and NaOCl solutions (P > 0.05). The Weibull analysis showed that the predicted cycles of WaveOne Gold in air was 1027 cycles for 99% survival. However, Reciproc instruments tested in NaOCl solution had the lowest predicted cycles (613 cycles) among the groups. Immersion of WaveOne Gold and Reciproc reciprocating instruments in saline and NaOCl solutions decreased considerably their cyclic fatigue resistance. The fatigue resistance of WaveOne Gold instruments was higher than that of Reciproc instruments. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Reciprocal role of vitamin D receptor on β-catenin regulated keratinocyte proliferation and differentiation.

PubMed

Hu, Lizhi; Bikle, Daniel D; Oda, Yuko

2014-10-01

The active metabolite of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), suppresses the proliferation while promoting the differentiation of keratinocytes through the vitamin D receptor (VDR). β-Catenin, on the other hand, promotes proliferation and blocks epidermal differentiation, although it stimulates hair follicle differentiation. In intestinal epithelia VDR binds β-catenin and blocks its proliferative effects. In this study we investigated the role of 1,25(OH)2D3/VDR on β-catenin regulated gene transcription during keratinocyte proliferation and differentiation. 1,25(OH)2D3 suppressed promoter reporter activity driven by synthetic and natural TCF/β-catenin response elements. Over-expression of VDR further suppressed these TCF/β-catenin promoter activities. 1,25(OH)2D3 also suppressed the mRNA expression of the β-catenin regulated gene Gli1 through VDR. These data were consistent with our previous observations that VDR silencing resulted in keratinocyte hyperproliferation with increased expression of Gli1 in vitro, whereas VDR null skin showed hyperproliferation in vivo. In contrast, 1,25(OH)2D3 induced expression of another β-catenin regulated gene, PADI1, important for both epidermal and hair follicle differentiation. Deletion of VDR resulted in defects in hair differentiation in vivo, with decreased expression of β-catenin regulated hair differentiation genes such as PADI1, hair keratin KRT31 and calcium binding protein S100a3. These genes possess vitamin D response elements (VDRE) adjacent to TCF/β-catenin response elements and are regulated by both VDR and β-catenin signaling. Therefore, we propose that VDR and β-catenin interact reciprocally to promote VDR stimulation of genes involved with differentiation that contain both VDR and β-catenin response elements while inhibiting β-catenin stimulation of genes involved with proliferation. Thus the major finding of this study is that while 1,25(OH)2D3/VDR inhibits the actions of β-catenin to promote keratinocyte proliferation, 1,25(OH)2D3/VDR promotes the ability of β-catenin to stimulate hair follicle differentiation. This article is part of a Special Issue entitled '16th Vitamin D Workshop'. Copyright © 2013 Elsevier Ltd. All rights reserved.

On Reciprocal Causation in the Evolutionary Process.

PubMed

Svensson, Erik I

2018-01-01

Recent calls for a revision of standard evolutionary theory (SET) are based partly on arguments about the reciprocal causation. Reciprocal causation means that cause-effect relationships are bi-directional, as a cause could later become an effect and vice versa. Such dynamic cause-effect relationships raise questions about the distinction between proximate and ultimate causes, as originally formulated by Ernst Mayr. They have also motivated some biologists and philosophers to argue for an Extended Evolutionary Synthesis (EES). The EES will supposedly expand the scope of the Modern Synthesis (MS) and SET, which has been characterized as gene-centred, relying primarily on natural selection and largely neglecting reciprocal causation. Here, I critically examine these claims, with a special focus on the last conjecture. I conclude that reciprocal causation has long been recognized as important by naturalists, ecologists and evolutionary biologists working in the in the MS tradition, although it it could be explored even further. Numerous empirical examples of reciprocal causation in the form of positive and negative feedback are now well known from both natural and laboratory systems. Reciprocal causation have also been explicitly incorporated in mathematical models of coevolutionary arms races, frequency-dependent selection, eco-evolutionary dynamics and sexual selection. Such dynamic feedback were already recognized by Richard Levins and Richard Lewontin in their bok The Dialectical Biologist . Reciprocal causation and dynamic feedback might also be one of the few contributions of dialectical thinking and Marxist philosophy in evolutionary theory. I discuss some promising empirical and analytical tools to study reciprocal causation and the implications for the EES. Finally, I briefly discuss how quantitative genetics can be adapated to studies of reciprocal causation, constructive inheritance and phenotypic plasticity and suggest that the flexibility of this approach might have been underestimated by critics of contemporary evolutionary biology.

Thermoacoustic Engines in Alternate Geometry Resonators

DTIC Science & Technology

1997-09-12

paper pieces fabricated by Micatron Incorporated. A schematic of a single stack element is shown in Fig. 3.2. The inner diameter of the pieces was...26.28 cm Figure 3.2: A single element of the radial wave "washer" style stack. The element is composed of silicon bonded mica paper with a thickness...washer shaped pieces of silicon bonded mica paper , described previously. An image of a single stack element is shown in Fig. 3.9. 39 Figure 3.7: The

Rethinking natural altruism: Simple reciprocal interactions trigger children’s benevolence

PubMed Central

Cortes Barragan, Rodolfo; Dweck, Carol S.

2014-01-01

A very simple reciprocal activity elicited high degrees of altruism in 1- and 2-y-old children, whereas friendly but nonreciprocal activity yielded little subsequent altruism. In a second study, reciprocity with one adult led 1- and 2-y-olds to provide help to a new person. These results question the current dominant claim that social experiences cannot account for early occurring altruistic behavior. A third study, with preschool-age children, showed that subtle reciprocal cues remain potent elicitors of altruism, whereas a fourth study with preschoolers showed that even a brief reciprocal experience fostered children’s expectation of altruism from others. Collectively, the studies suggest that simple reciprocal interactions are a potent trigger of altruism for young children, and that these interactions lead children to believe that their relationships are characterized by mutual care and commitment. PMID:25404334

Sex differences in the reciprocal behaviour of children with autism.

PubMed

Backer van Ommeren, Tineke; Koot, Hans M; Scheeren, Anke M; Begeer, Sander

2017-08-01

Differences in the social limitations of girls compared to boys on the autism spectrum are still poorly understood. Impaired social-emotional reciprocity is a core diagnostic criterion for an autism spectrum disorder. This study compares sex differences in reciprocal behaviour in children with autism spectrum disorder (32 girls, 114 boys) and in typically developing children (24 girls, 55 boys). While children with autism spectrum disorder showed clear limitations in reciprocal behaviour compared to typically developing children, sex differences were found only in the autism spectrum disorder group: girls with autism spectrum disorder had higher reciprocity scores than boys with autism spectrum disorder. However, compared to typically developing girls, girls with autism spectrum disorder showed subtle differences in reciprocal behaviour. The sex-specific response patterns in autism spectrum disorder can inform and improve the diagnostic assessment of autism in females.

Methods for synthesizing semiconductor quality chalcopyrite crystals for nonlinear optical and radiation detection applications and the like

DOEpatents

Stowe, Ashley; Burger, Arnold

2016-05-10

A method for synthesizing I-III-VI.sub.2 compounds, including: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound under heat, with mixing, and/or via vapor transport. The Group III element is melted at a temperature of between about 200 degrees C. and about 700 degrees C. Preferably, the Group I element consists of a neutron absorber and the group III element consists of In or Ga. The Group VI element and the single phase I-III compound are heated to a temperature of between about 700 degrees C. and about 1000 degrees C. Preferably, the Group VI element consists of S, Se, or Te. Optionally, the method also includes doping with a Group IV element activator.

Clustering in large networks does not promote upstream reciprocity.

PubMed

Masuda, Naoki

2011-01-01

Upstream reciprocity (also called generalized reciprocity) is a putative mechanism for cooperation in social dilemma situations with which players help others when they are helped by somebody else. It is a type of indirect reciprocity. Although upstream reciprocity is often observed in experiments, most theories suggest that it is operative only when players form short cycles such as triangles, implying a small population size, or when it is combined with other mechanisms that promote cooperation on their own. An expectation is that real social networks, which are known to be full of triangles and other short cycles, may accommodate upstream reciprocity. In this study, I extend the upstream reciprocity game proposed for a directed cycle by Boyd and Richerson to the case of general networks. The model is not evolutionary and concerns the conditions under which the unanimity of cooperative players is a Nash equilibrium. I show that an abundance of triangles or other short cycles in a network does little to promote upstream reciprocity. Cooperation is less likely for a larger population size even if triangles are abundant in the network. In addition, in contrast to the results for evolutionary social dilemma games on networks, scale-free networks lead to less cooperation than networks with a homogeneous degree distribution.

Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity.

PubMed

Yamagishi, Toshio; Horita, Yutaka; Mifune, Nobuhiro; Hashimoto, Hirofumi; Li, Yang; Shinada, Mizuho; Miura, Arisa; Inukai, Keigo; Takagishi, Haruto; Simunovic, Dora

2012-12-11

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner's dilemma game. We did not find any correlation between the participants' tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants' responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status.

Behavioral and neuronal determinants of negative reciprocity in the ultimatum game

PubMed Central

Hildebrandt, Andrea; Wilhelm, Oliver; Sommer, Werner

2016-01-01

The rejection of unfair offers in the ultimatum game (UG) indicates negative reciprocity. The model of strong reciprocity claims that negative reciprocity reflects prosociality because the rejecting individual is sacrificing resources in order to punish unfair behavior. However, a recent study found that the rejection rate of unfair offers is linked to assertiveness (status defense model). To pursue the question what drives negative reciprocity, the present study investigated individual differences in the rejection of unfair offers along with their behavioral and neuronal determinants. We measured fairness preferences and event-related potentials (ERP) in 200 healthy participants playing a computerized version of the UG with pictures of unfair and fair proposers. Structural equation modeling (SEM) on the behavioral data corroborated both the strong reciprocity and the status defense models of human cooperation: Not only more prosocial but also more assertive individuals were more likely to show negative reciprocity by rejecting unfair offers. Experimental ERP results confirmed the feedback negativity (FN) as a neural signature of fairness processing. Multilevel SEM of brain–behavior relationships revealed that negative reciprocity was significantly associated with individual differences in FN amplitudes in response to proposers. Our results confirm stable individual differences in fairness processing at the behavioral and neuronal level. PMID:27261490

Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity

PubMed Central

Yamagishi, Toshio; Horita, Yutaka; Mifune, Nobuhiro; Hashimoto, Hirofumi; Li, Yang; Shinada, Mizuho; Miura, Arisa; Inukai, Keigo; Takagishi, Haruto; Simunovic, Dora

2012-01-01

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner’s dilemma game. We did not find any correlation between the participants’ tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants’ responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status. PMID:23188801

Clustering in Large Networks Does Not Promote Upstream Reciprocity

PubMed Central

Masuda, Naoki

2011-01-01

Upstream reciprocity (also called generalized reciprocity) is a putative mechanism for cooperation in social dilemma situations with which players help others when they are helped by somebody else. It is a type of indirect reciprocity. Although upstream reciprocity is often observed in experiments, most theories suggest that it is operative only when players form short cycles such as triangles, implying a small population size, or when it is combined with other mechanisms that promote cooperation on their own. An expectation is that real social networks, which are known to be full of triangles and other short cycles, may accommodate upstream reciprocity. In this study, I extend the upstream reciprocity game proposed for a directed cycle by Boyd and Richerson to the case of general networks. The model is not evolutionary and concerns the conditions under which the unanimity of cooperative players is a Nash equilibrium. I show that an abundance of triangles or other short cycles in a network does little to promote upstream reciprocity. Cooperation is less likely for a larger population size even if triangles are abundant in the network. In addition, in contrast to the results for evolutionary social dilemma games on networks, scale-free networks lead to less cooperation than networks with a homogeneous degree distribution. PMID:21998641

Reciprocity of agonistic support in ravens

PubMed Central

Fraser, Orlaith N.; Bugnyar, Thomas

2012-01-01

Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim’s likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals. PMID:22298910

Teacher License Reciprocity. 50-State Review

ERIC Educational Resources Information Center

Aragon, Stephanie

2017-01-01

This policy report defines and provides a 50-state review of teacher license reciprocity, explores how state-specific licensing requirements impact the teacher labor market, and includes examples of national and state efforts to facilitate reciprocity.

47 CFR 51.711 - Symmetrical reciprocal compensation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 3 2013-10-01 2013-10-01 false Symmetrical reciprocal compensation. 51.711 Section 51.711 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERCONNECTION Reciprocal Compensation for Transport and Termination of Telecommunications...

Static non-reciprocity in mechanical metamaterials.

PubMed

Coulais, Corentin; Sounas, Dimitrios; Alù, Andrea

2017-02-23

Reciprocity is a general, fundamental principle governing various physical systems, which ensures that the transfer function-the transmission of a physical quantity, say light intensity-between any two points in space is identical, regardless of geometrical or material asymmetries. Breaking this transmission symmetry offers enhanced control over signal transport, isolation and source protection. So far, devices that break reciprocity (and therefore show non-reciprocity) have been mostly considered in dynamic systems involving electromagnetic, acoustic and mechanical wave propagation associated with fields varying in space and time. Here we show that it is possible to break reciprocity in static systems, realizing mechanical metamaterials that exhibit vastly different output displacements under excitation from different sides, as well as one-way displacement amplification. This is achieved by combining large nonlinearities with suitable geometrical asymmetries and/or topological features. In addition to extending non-reciprocity and isolation to statics, our work sheds light on energy propagation in nonlinear materials with asymmetric crystalline structures and topological properties. We anticipate that breaking reciprocity will open avenues for energy absorption, conversion and harvesting, soft robotics, prosthetics and optomechanics.

Reciprocal Family, Friendship and Church Support Networks of African Americans: Findings from the National Survey of American Life.

PubMed

Taylor, Robert Joseph; Mouzon, Dawne M; Nguyen, Ann W; Chatters, Linda M

2016-12-01

This study examined reciprocal support networks involving extended family, friends and church members among African Americans. Our analysis examined specific patterns of reciprocal support (i.e., received only, gave only, both gave and received, neither gave or received), as well as network characteristics (i.e., contact and subjective closeness) as correlates of reciprocal support. The analysis is based on the African American sub-sample of the National Survey of American Life (NSAL). Overall, our findings indicate that African Americans are very involved in reciprocal support networks with their extended family, friends and church members. Respondents were most extensively involved in reciprocal supports with extended family members, followed closely by friends and church networks. Network characteristics (i.e., contact and subjective closeness) were significantly and consistently associated with involvement with reciprocal support exchanges for all three networks. These and other findings are discussed in detail. This study complements previous work on the complementary roles of family, friend and congregational support networks, as well as studies of racial differences in informal support networks.

Diverse ontogenies of reciprocal and prosocial behavior: cooperative development in Fiji and the United States.

PubMed

House, Bailey R

2017-11-01

Contingent reciprocity is an important foundation of human cooperation, but we know little about how reciprocal behavior develops across diverse societies, nor about how the development of reciprocal behavior is related to the development of prosocial behavior more broadly. Three- to 16-year-old children were presented with the opportunity to control the allocation of real food rewards in a binary-choice cooperative dilemma. Within dyads children alternated making choices across multiple trials, and reciprocal behavior emerged in three diverse populations (rural Fijian villages, and urban communities in both Fiji and the United States) by age 7-8. There was more societal variation in prosocial behavior than in reciprocal behavior, and there were more substantial differences between Fijians and Americans than between rural and urban populations. This suggests that the development of prosocial behavior is not driven entirely by the development of reciprocity, and differences in prosocial behavior across rural Fijians and urban Americans may not be due only to differences across rural and urban populations. © 2016 John Wiley & Sons Ltd.

Atomic resolution elemental mapping using energy-filtered imaging scanning transmission electron microscopy with chromatic aberration correction.

PubMed

Krause, F F; Rosenauer, A; Barthel, J; Mayer, J; Urban, K; Dunin-Borkowski, R E; Brown, H G; Forbes, B D; Allen, L J

2017-10-01

This paper addresses a novel approach to atomic resolution elemental mapping, demonstrating a method that produces elemental maps with a similar resolution to the established method of electron energy-loss spectroscopy in scanning transmission electron microscopy. Dubbed energy-filtered imaging scanning transmission electron microscopy (EFISTEM) this mode of imaging is, by the quantum mechanical principle of reciprocity, equivalent to tilting the probe in energy-filtered transmission electron microscopy (EFTEM) through a cone and incoherently averaging the results. In this paper we present a proof-of-principle EFISTEM experimental study on strontium titanate. The present approach, made possible by chromatic aberration correction, has the advantage that it provides elemental maps which are immune to spatial incoherence in the electron source, coherent aberrations in the probe-forming lens and probe jitter. The veracity of the experiment is supported by quantum mechanical image simulations, which provide an insight into the image-forming process. Elemental maps obtained in EFTEM suffer from the effect known as preservation of elastic contrast, which, for example, can lead to a given atomic species appearing to be in atomic columns where it is not to be found. EFISTEM very substantially reduces the preservation of elastic contrast and yields images which show stability of contrast with changing thickness. The experimental application is demonstrated in a proof-of-principle study on strontium titanate. Copyright © 2017 Elsevier B.V. All rights reserved.

Acoustic reciprocity: An extension to spherical harmonics domain.

PubMed

Samarasinghe, Prasanga; Abhayapala, Thushara D; Kellermann, Walter

2017-10-01

Acoustic reciprocity is a fundamental property of acoustic wavefields that is commonly used to simplify the measurement process of many practical applications. Traditionally, the reciprocity theorem is defined between a monopole point source and a point receiver. Intuitively, it must apply to more complex transducers than monopoles. In this paper, the authors formulate the acoustic reciprocity theory in the spherical harmonics domain for directional sources and directional receivers with higher order directivity patterns.

Mechanism of magnetic liquid flowing in the magnetic liquid seal gap of reciprocating shaft

NASA Astrophysics Data System (ADS)

Li, Decai; Chui, Haichun; Yang, Qingxin

2003-04-01

In order to solve the problems that exist in the magnetic liquid seal of reciprocating shaft, we have set up an experimental facility, which composes a camera, a microscope, a step-by-step motor, a pin roller screw, a reciprocating motion shaft, pole pieces, a permanent magnet and the magnetic liquid in the seal gap. Through the optical technology and image process of the experimental facility, we have studied the magnetic liquid flow in the seal gap when the reciprocating shaft moves with different velocities and strokes, this study especially concentrates on 1) the regular pattern of such flow; 2) the loss quantity of magnetic liquid caused by the reciprocating motion shaft; 3) the failure reasons of this magnetic liquid seal and 4) the design of a new structure for the magnetic liquid seal of reciprocating shaft. The application indicates that the new structure is very effective in some occasions.

Perceptions of intimacy and friendship reciprocity moderate peer influence on aggression.

PubMed

Meter, Diana J; Casper, Deborah M; Card, Noel A

2015-01-01

Previous research has shown that close friends' influence can exacerbate adolescents' aggressive behavior, but results of studies which examine whether friendships of greater or lesser qualities moderate peer influence effects are inconsistent. The present study tested whether the perception of the positive friendship quality of intimate exchange and friendship reciprocity moderated best friend influence on participant aggression over time. The 243 participants were approximately 12 years old and ethnically diverse. Neither intimate exchange nor reciprocity significantly moderated friend influence on aggression in a simple way, but the interaction of intimate exchange and friendship reciprocity predicted peer influence on participants' aggression over time. Specifically, highly intimate, nonreciprocal best friendships and less intimate, reciprocal best friendships showed greatest influence when friends' proportion of peer nominations for aggression was high. Reciprocity and intimacy should be considered when predicting peer influence on aggression. © 2014 Wiley Periodicals, Inc.

Indirect reciprocity can overcome free-rider problems on costly moral assessment.

PubMed

Sasaki, Tatsuya; Okada, Isamu; Nakai, Yutaka

2016-07-01

Indirect reciprocity is one of the major mechanisms of the evolution of cooperation. Because constant monitoring and accurate evaluation in moral assessments tend to be costly, indirect reciprocity can be exploited by cost evaders. A recent study crucially showed that a cooperative state achieved by indirect reciprocators is easily destabilized by cost evaders in the case with no supportive mechanism. Here, we present a simple and widely applicable solution that considers pre-assessment of cost evaders. In the pre-assessment, those who fail to pay for costly assessment systems are assigned a nasty image that leads to them being rejected by discriminators. We demonstrate that considering the pre-assessment can crucially stabilize reciprocal cooperation for a broad range of indirect reciprocity models. In particular for the most leading social norms, we analyse the conditions under which a prosocial state becomes locally stable. © 2016 The Authors.

Marital conflict and the quality of young children's peer play behavior: the mediating and moderating role of parent-child emotional reciprocity and attachment security.

PubMed

Lindsey, Eric W; Caldera, Yvonne M; Tankersley, Laura

2009-04-01

Parent-child attachment security and dyadic measures of parent-child positive and negative emotional reciprocity were examined as possible mediators and moderators of the connection between marital conflict and children's peer play behavior. Eighty parents were observed in a laboratory play session with their 15- to 18-month-old child. Subsequently, at 36 months children were observed interacting with peers at their child care setting. Connections between marital conflict and children's positive peer interaction were mediated by mother-child attachment security, mother-child positive emotional reciprocity, and father-child negative emotional reciprocity. Connections between marital conflict and children's negative peer interaction were mediated by mother-child positive emotional reciprocity and father-child attachment security. Parent-child attachment security and negative emotional reciprocity emerged as important moderators of the connection between marital conflict and children's peer play behavior.

Perceptions of intimacy and friendship reciprocity moderate peer influence on aggression.

PubMed

Meter, Diana J; Casper, Deborah M; Card, Noel A

2014-12-15

Previous research has shown that close friends' influence can exacerbate adolescents' aggressive behavior, but results of studies which examine whether friendships of greater or lesser qualities moderate peer influence effects are inconsistent. The present study tested whether the perception of the positive friendship quality of intimate exchange and friendship reciprocity moderated best friend influence on participant aggression over time. The 243 participants were approximately 12 years old and ethnically diverse. Neither intimate exchange nor reciprocity significantly moderated friend influence on aggression in a simple way, but the interaction of intimate exchange and friendship reciprocity predicted peer influence on participants' aggression over time. Specifically, highly intimate, nonreciprocal best friendships and less intimate, reciprocal best friendships showed greatest influence when friends' proportion of peer nominations for aggression was high. Reciprocity and intimacy should be considered when predicting peer influence on aggression. Aggr. Behav. 9999:1-11, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

New opportunities for future small civil turbine engines: Overviewing the GATE studies

NASA Technical Reports Server (NTRS)

Strack, W. C.

1979-01-01

An overview of four independent studies forecasts the potential impact of advanced technology turbine engines in the post 1988 market, identifies important aircraft and missions, desirable engine sizes, engine performance, and cost goals. Parametric evaluations of various engine cycles, configurations, design features, and advanced technology elements defined baseline conceptual engines for each of the important missions identified by the market analysis. Both fixed-wing and helicopter aircraft, and turboshaft, turboprop, and turbofan engines were considered. Sizable performance gains (e.g., 20% SFC decrease), and large engine cost reductions of sufficient magnitude are predicted to challenge the reciprocating engine in the 300-500 SHP class.

Petrographic evidence shows that pottery exchange between the Olmec and their neighbors was two-way

PubMed Central

Stoltman, James B.; Marcus, Joyce; Flannery, Kent V.; Burton, James H.; Moyle, Robert G.

2005-01-01

Petrographic thin sections of pottery from five Formative Mexican archaeological sites show that exchanges of vessels between highland and lowland chiefly centers were reciprocal, or two-way. These analyses contradict recent claims that the Gulf Coast was the sole source of pottery carved with iconographic motifs. Those claims were based on neutron activation, which, by relying on chemical elements rather than actual minerals, has important limitations in its ability to identify nonlocal pottery from within large data sets. Petrography shows that the ceramics in question (and hence their carved motifs) have multiple origins and were widely traded. PMID:16061796

Assessment of advanced technologies for high performance single-engine business airplanes

NASA Technical Reports Server (NTRS)

Kohlman, D. L.; Holmes, B. J.

1982-01-01

The prospects for significantly increasing the fuel efficiency and mission capability of single engine business aircraft through the incorporation of advanced propulsion, aerodynamics and materials technologies are explored. It is found that turbine engines cannot match the fuel economy of the heavier rotary, diesel and advanced spark reciprocating engines. The rotary engine yields the lightest and smallest aircraft for a given mission requirement, and also offers greater simplicity and a multifuel capability. Great promise is also seen in the use of composite material primary structures in conjunction with laminar flow wing surfaces, a pusher propeller and conventional wing-tail configuration. This study was conducted with the General Aviation Synthesis Program, which can furnish the most accurate mission performance calculations yet obtained.

[Hygiene between tradition and implementation].

PubMed

Hansis, M L

2004-04-01

The basis of evidence for hygiene rules implemented in hospitals is traditionally small. This is not only because there is little theoretical knowledge on the reciprocal influence between a single hygienic mistake/a single microbial input and the manifestation of a nosocomial infection. There are also not enough clinical studies, especially on complex hygiene questions, to determine whether special measures (e.g., septic rooms)can compensate for deficits in hygiene practice. Furthermore, it would be necessary to designate security buffers distinctly. In-house traditions are able to stabilize hygienic behavior in an excellent manner. They should be fostered and not disparaged as myths. Discussions of experts should not be conducted in public; that is disastrous for the everyday work of physicians in hospitals.

General practitioners' perceptions of the stigma of dementia and the role of reciprocity.

PubMed

Gove, Dianne; Small, Neil; Downs, Murna; Vernooij-Dassen, Myrra

2017-10-01

A qualitative exploration of the stigma of dementia reported that general practitioners described lack of reciprocity as one way in which people with dementia are perceived within society. This was closely linked to their perception of dementia as a stigma. In this article, we explore whether general practitioners perceive people with dementia as lacking reciprocity and, if so, if this is linked with societal opinions about dementia as a stigma. The implications of both perceptions of people with dementia failing to reciprocate and of stigma for timely diagnosis are explored. Our approach is to follow the thread of reciprocity in the data from our initial study. In this follow-up study, general practitioners' perceptions of societal views of people with dementia included a perception of a lack of reciprocity specifically linked with; failing to respond to human contact, the absence of an appropriate return on social investment and failing to contribute to, or being a burden on, society. General practitioners reported a link between societal perceptions of lack of reciprocity and stereotypes about advanced dementia, difficulties communicating with people with dementia, and lack of opportunities for people with dementia to reciprocate. General practitioners occupy a key position, they can challenge stereotypes and, with support and targeted training about communicating with people living with dementia, can emphasize the ways in which people with dementia can communicate, thereby enhancing their potential to reciprocate. Such changes have implications for improved care and quality of life through the continued maintenance of social inclusion and perceptions of personhood.

Simulation of a Single-Element Lean-Direct Injection Combustor Using a Polyhedral Mesh Derived from Hanging-Node Elements

NASA Technical Reports Server (NTRS)

Wey, Thomas; Liu, Nan-Suey

2013-01-01

This paper summarizes the procedures of generating a polyhedral mesh derived from hanging-node elements as well as presents sample results from its application to the numerical solution of a single element lean direct injection (LDI) combustor using an open-source version of the National Combustion Code (NCC).

Reciprocal relations for transmission coefficients - Theory and application

NASA Technical Reports Server (NTRS)

Qu, Jianmin; Achenbach, Jan D.; Roberts, Ronald A.

1989-01-01

The authors present a rigorous proof of certain intuitively plausible reciprocal relations for time harmonic plane-wave transmission and reflection at the interface between a fluid and an anisotropic elastic solid. Precise forms of the reciprocity relations for the transmission coefficients and for the transmitted energy fluxes are derived, based on the reciprocity theorem of elastodynamics. It is shown that the reciprocity relations can be used in conjunction with measured values of peak amplitudes for transmission through a slab of the solid (water-solid-water) to obtain the water-solid coefficients. Experiments were performed for a slab of a unidirectional fiber-reinforced composite. Good agreement of the experimentally measured transmission coefficients with theoretical values was obtained.

Relatedness decreases and reciprocity increases cooperation in Norway rats.

PubMed

Schweinfurth, Manon K; Taborsky, Michael

2018-03-14

Kin selection and reciprocity are two mechanisms underlying the evolution of cooperation, but the relative importance of kinship and reciprocity for decisions to cooperate are yet unclear for most cases of cooperation. Here, we experimentally tested the relative importance of relatedness and received cooperation for decisions to help a conspecific in wild-type Norway rats ( Rattus norvegicus ). Test rats provided more food to non-kin than to siblings, and they generally donated more food to previously helpful social partners than to those that had refused help. The rats thus applied reciprocal cooperation rules irrespective of relatedness, highlighting the importance of reciprocal help for cooperative interactions among both related and unrelated conspecifics. © 2018 The Author(s).

Immaterial and monetary gifts in economic transactions: evidence from the field.

PubMed

Kirchler, Michael; Palan, Stefan

2018-01-01

Reciprocation of monetary gifts is well-understood in economics. In contrast, there is little research on reciprocal behavior following immaterial gifts like compliments. We narrow this gap and investigate how employees reciprocate after receiving immaterial gifts and material gifts over time. We purchase (1) ice cream from fast food restaurants, and (2) durum doner, a common lunch snack, from independent vendors. Prior to the food's preparation, we either compliment or tip the salesperson. We find that salespersons reciprocate compliments with higher product weight than in a control treatment. Importantly, this reciprocal behavior following immaterial gifts grows over repeated transactions. Tips, in contrast, have a stronger level effect which does not change over time.

Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading

DOE PAGES

Fan, D.; Huang, J. W.; Zeng, X. L.; ...

2016-05-23

We develop a mini gas gun system for simultaneous, single-pulse, x-ray diffraction and imaging under high strain-rate loading at the beamline 32-ID of the Advanced Photon Source. In order to increase the reciprocal space covered by a small-area detector, a conventional target chamber is split into two chambers: a narrowed measurement chamber and a relief chamber. The gas gun impact is synchronized with synchrotron x-ray pulses and high-speed cameras. Depending on a camera’s capability, multiframe imaging and diffraction can be achieved. The proof-of-principle experiments are performed on single-crystal sapphire. The diffraction spots and images during impact are analyzed to quantifymore » lattice deformation and fracture; diffraction peak broadening is largely caused by fracture-induced strain inhomogeneity. Finally, our results demonstrate the potential of such multiscale measurements for revealing and understanding high strain-rate phenomena at dynamic extremes.« less

Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading

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

Fan, D.; Huang, J. W.; Zeng, X. L.

We develop a mini gas gun system for simultaneous, single-pulse, x-ray diffraction and imaging under high strain-rate loading at the beamline 32-ID of the Advanced Photon Source. In order to increase the reciprocal space covered by a small-area detector, a conventional target chamber is split into two chambers: a narrowed measurement chamber and a relief chamber. The gas gun impact is synchronized with synchrotron x-ray pulses and high-speed cameras. Depending on a camera’s capability, multiframe imaging and diffraction can be achieved. The proof-of-principle experiments are performed on single-crystal sapphire. The diffraction spots and images during impact are analyzed to quantifymore » lattice deformation and fracture; diffraction peak broadening is largely caused by fracture-induced strain inhomogeneity. Finally, our results demonstrate the potential of such multiscale measurements for revealing and understanding high strain-rate phenomena at dynamic extremes.« less

Why an extended evolutionary synthesis is necessary

PubMed Central

2017-01-01

Since the last major theoretical integration in evolutionary biology—the modern synthesis (MS) of the 1940s—the biosciences have made significant advances. The rise of molecular biology and evolutionary developmental biology, the recognition of ecological development, niche construction and multiple inheritance systems, the ‘-omics’ revolution and the science of systems biology, among other developments, have provided a wealth of new knowledge about the factors responsible for evolutionary change. Some of these results are in agreement with the standard theory and others reveal different properties of the evolutionary process. A renewed and extended theoretical synthesis, advocated by several authors in this issue, aims to unite pertinent concepts that emerge from the novel fields with elements of the standard theory. The resulting theoretical framework differs from the latter in its core logic and predictive capacities. Whereas the MS theory and its various amendments concentrate on genetic and adaptive variation in populations, the extended framework emphasizes the role of constructive processes, ecological interactions and systems dynamics in the evolution of organismal complexity as well as its social and cultural conditions. Single-level and unilinear causation is replaced by multilevel and reciprocal causation. Among other consequences, the extended framework overcomes many of the limitations of traditional gene-centric explanation and entails a revised understanding of the role of natural selection in the evolutionary process. All these features stimulate research into new areas of evolutionary biology. PMID:28839929

Efficiency of the Self Adjusting File, WaveOne, Reciproc, ProTaper and hand files in root canal debridement.

PubMed

Topcu, K Meltem; Karatas, Ertugrul; Ozsu, Damla; Ersoy, Ibrahim

2014-07-01

The aim of this study was to compare the canal debridement capabilities of three single file systems, ProTaper, and K-files in oval-shaped canals. Seventy-five extracted human mandibular central incisors with oval-shaped root canals were selected. A radiopaque contrast medium (Metapex; Meta Biomed Co. Ltd., Chungcheongbuk-do, Korea) was introduced into the canal systems and the self-adjusting file (SAF), WaveOne, Reciproc, ProTaper, and K-files were used for the instrumentation of the canals. The percentage of removed contrast medium was calculated using pre- and post-operative radiographs. An overall comparison between the groups revealed that the hand file (HF) and SAF groups presented the lowest percentage of removed contrast medium, whereas the WaveOne group showed the highest percentage (P < 0.001). The ProTaper group removed more contrast medium than the SAF and HF groups (P < 0.05). None of the instruments was able to remove the contrast medium completely. WaveOne performed significantly better than other groups.

Efficiency of the Self Adjusting File, WaveOne, Reciproc, ProTaper and hand files in root canal debridement

PubMed Central

Topcu, K. Meltem; Karatas, Ertugrul; Ozsu, Damla; Ersoy, Ibrahim

2014-01-01

Objectives: The aim of this study was to compare the canal debridement capabilities of three single file systems, ProTaper, and K-files in oval-shaped canals. Materials and Methods: Seventy-five extracted human mandibular central incisors with oval-shaped root canals were selected. A radiopaque contrast medium (Metapex; Meta Biomed Co. Ltd., Chungcheongbuk-do, Korea) was introduced into the canal systems and the self-adjusting file (SAF), WaveOne, Reciproc, ProTaper, and K-files were used for the instrumentation of the canals. The percentage of removed contrast medium was calculated using pre- and post-operative radiographs. Results: An overall comparison between the groups revealed that the hand file (HF) and SAF groups presented the lowest percentage of removed contrast medium, whereas the WaveOne group showed the highest percentage (P < 0.001). The ProTaper group removed more contrast medium than the SAF and HF groups (P < 0.05). Conclusions: None of the instruments was able to remove the contrast medium completely. WaveOne performed significantly better than other groups. PMID:25202211

Simple Y-autosomal incompatibilities cause hybrid male sterility in reciprocal crosses between Drosophila virilis and D. americana.

PubMed

Sweigart, Andrea L

2010-03-01

Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F(1) hybrid males are perfectly fertile. Second, later generation (backcross and F(2)) hybrid male sterility between D. virilis and D. americana is not polygenic. In fact, I identified only three genetically independent incompatibilities that cause hybrid male sterility. Remarkably, each of these incompatibilities involves the Y chromosome. In one direction of the cross, the D. americana Y is incompatible with recessive D. virilis alleles at loci on chromosomes 2 and 5. In the other direction, the D. virilis Y chromosome causes hybrid male sterility in combination with recessive D. americana alleles at a single QTL on chromosome 5. Finally, in contrast with findings from other Drosophila species pairs, the X chromosome has only a modest effect on hybrid male sterility between D. virilis and D. americana.

Simple Y-Autosomal Incompatibilities Cause Hybrid Male Sterility in Reciprocal Crosses Between Drosophila virilis and D. americana

PubMed Central

Sweigart, Andrea L.

2010-01-01

Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F1 hybrid males are perfectly fertile. Second, later generation (backcross and F2) hybrid male sterility between D. virilis and D. americana is not polygenic. In fact, I identified only three genetically independent incompatibilities that cause hybrid male sterility. Remarkably, each of these incompatibilities involves the Y chromosome. In one direction of the cross, the D. americana Y is incompatible with recessive D. virilis alleles at loci on chromosomes 2 and 5. In the other direction, the D. virilis Y chromosome causes hybrid male sterility in combination with recessive D. americana alleles at a single QTL on chromosome 5. Finally, in contrast with findings from other Drosophila species pairs, the X chromosome has only a modest effect on hybrid male sterility between D. virilis and D. americana. PMID:20048051

A diffusion approach to approximating preservation probabilities for gene duplicates.

PubMed

O'Hely, Martin

2006-08-01

Consider a haploid population and, within its genome, a gene whose presence is vital for the survival of any individual. Each copy of this gene is subject to mutations which destroy its function. Suppose one member of the population somehow acquires a duplicate copy of the gene, where the duplicate is fully linked to the original gene's locus. Preservation is said to occur if eventually the entire population consists of individuals descended from this one which initially carried the duplicate. The system is modelled by a finite state-space Markov process which in turn is approximated by a diffusion process, whence an explicit expression for the probability of preservation is derived. The event of preservation can be compared to the fixation of a selectively neutral gene variant initially present in a single individual, the probability of which is the reciprocal of the population size. For very weak mutation, this and the probability of preservation are equal, while as mutation becomes stronger, the preservation probability tends to double this reciprocal. This is in excellent agreement with simulation studies.

Why seeking help from teammates is a blessing and a curse: a theory of help seeking and individual creativity in team contexts.

PubMed

Mueller, Jennifer S; Kamdar, Dishan

2011-03-01

Research has not explored the extent to which seeking help from teammates positively relates to a person's own creativity. This question is important to explore as help seeking is commonly enacted in organizations and may come with reciprocation costs that may also diminish creativity. Results based on 291 employees in a single division of a large multinational organization revealed that seeking help predicted creativity and mediated the relationship between intrinsic motivation and creativity. However, help seekers also incurred reciprocation costs in that they tended to give more help to teammates, and giving help to teammates was negatively related to creativity. In general, giving higher levels of help attenuated the positive relationship between help seeking and creativity. We also tested an integrated model to show that help giving moderated the mediated relationship between intrinsic motivation and creativity via help seeking, such that higher levels of help giving attenuated this mediated effect. We discuss theoretical and practical implications recommending additional research regarding the interpersonal creative process in team contexts. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Feed-forward and reciprocal inhibition for gain and phase timing control in a computational model of repetitive cough

PubMed Central

Morris, Kendall F.; Segers, Lauren S.; Poliacek, Ivan; Rose, Melanie J.; Lindsey, Bruce G.; Davenport, Paul W.; Howland, Dena R.; Bolser, Donald C.

2016-01-01

We investigated the hypothesis, motivated in part by a coordinated computational cough network model, that second-order neurons in the nucleus tractus solitarius (NTS) act as a filter and shape afferent input to the respiratory network during the production of cough. In vivo experiments were conducted on anesthetized spontaneously breathing cats. Cough was elicited by mechanical stimulation of the intrathoracic airways. Electromyograms of the parasternal (inspiratory) and rectus abdominis (expiratory) muscles and esophageal pressure were recorded. In vivo data revealed that expiratory motor drive during bouts of repetitive coughs is variable: peak expulsive amplitude increases from the first cough, peaks about the eighth or ninth cough, and then decreases through the remainder of the bout. Model simulations indicated that feed-forward inhibition of a single second-order neuron population is not sufficient to account for this dynamic feature of a repetitive cough bout. When a single second-order population was split into two subpopulations (inspiratory and expiratory), the resultant model produced simulated expiratory motor bursts that were comparable to in vivo data. However, expiratory phase durations during these simulations of repetitive coughing had less variance than those in vivo. Simulations in which reciprocal inhibitory processes between inspiratory-decrementing and expiratory-augmenting-late neurons were introduced exhibited increased variance in the expiratory phase durations. These results support the prediction that serial and parallel processing of airway afferent signals in the NTS play a role in generation of the motor pattern for cough. PMID:27283917