Relative and absolute reliability of the clinical version of the Narrow Path Walking Test (NPWT) under single and dual task conditions.

Decline in gait stability has been associated with increased fall risk in older adults. Reliable and clinically feasible methods of gait instability assessment are needed. This study evaluated the relative and absolute reliability and concurrent validity of the testing procedure of the clinical version of the Narrow Path Walking Test (NPWT) under single task (ST) and dual task (DT) conditions. Thirty independent community-dwelling older adults (65-87 years) were tested twice. Participants were instructed to walk within the 6-m narrow path without stepping out. Trial time, number of steps, trial velocity, number of step errors, and number of cognitive task errors were determined. Intraclass correlation coefficients (ICCs) were calculated as indices of agreement, and a graphic approach called "mountain plot" was applied to help interpret the direction and magnitude of disagreements between testing procedures. Smallest detectable change and smallest real difference (SRD) were computed to determine clinically relevant improvement at group and individual levels, respectively. Concurrent validity was assessed using Performance Oriented Mobility Assessment Tool (POMA) and the Short Physical Performance Battery (SPPB). Test-retest agreement (ICC1,2) varied from 0.77 to 0.92 in ST and from 0.78 to 0.92 in DT conditions, with no apparent systematic differences between testing procedures demonstrated by the mountain plot graphs. Smallest detectable change and smallest real change were small for motor task performance and larger for cognitive errors. Significant correlations were observed for trial velocity and trial time with POMA and SPPB. The present results indicate that the NPWT testing procedure is highly reliable and reproducible.

Dual boundary element formulation applied to analysis of multi-fractured domains

This paper deals with analysis of multiple random crack propagation in two-dimensional domains using the boundary element method (BEM). BEM is known to be a robust and accurate numerical technique for analysing this type of problem. The formulation adopted in this work is based on the dual BEM, for which singular and hyper-singular integral equations are used. We propose an iterative scheme to predict the crack growth path and the crack length increment at each time step. The proposed scheme able us to simulate localisation and coalescence phenomena, which is the main contribution of this paper. Considering the fracture mechanics analysis, the displacement correlation technique is applied to evaluate the stress intensity factors. The propagation angle and the equivalent stress intensity factor are calculated using the theory of maximum circumferential stress. Examples of simple and multi-fractured domains, loaded up to the rupture, are considered to illustrate the applicability of the proposed scheme. (C) 2010 Elsevier Ltd. All rights reserved.

Simultaneous cell morphometry and refractive index measurement with dual-wavelength digital holographic microscopy and dye-enhanced dispersion of perfusion medium.

Digital holographic microscopy (DHM) allows optical-path-difference (OPD) measurements with nanometric accuracy. OPD induced by transparent cells depends on both the refractive index (RI) of cells and their morphology. This Letter presents a dual-wavelength DHM that allows us to separately measure both the RI and the cellular thickness by exploiting an enhanced dispersion of the perfusion medium achieved by the utilization of an extracellular dye. The two wavelengths are chosen in the vicinity of the absorption peak of the dye, where the absorption is accompanied by a significant variation of the RI as a function of the wavelength.

Dual-mode RNS based programmable decimation filter for WCDMA and WLANa

The recent trends envisage multi-standard architectures as a promising solution for the future wireless transceivers. The computationally intensive decimation filter plays an important role in channel selection for multi-mode systems. An efficient reconfigurable implementation is a key to achieve low power consumption. To this end, this paper presents a dual-mode Residue Number System (RNS) based decimation filter which can be programmed for WCDMA and 802.11a standards. Decimation is done using multistage, multirate finite impulse response (FIR) filters. These FIR filters implemented in RNS domain offers high speed because of its carry free operation on smaller residues in parallel channels. Also, the FIR filters exhibit programmability to a selected standard by reconfiguring the hardware architecture. The total area is increased only by 33% to include WLANa compared to a single mode WCDMA transceiver. In each mode, the unused parts of the overall architecture is powered down and bypassed to attain power saving. The performance of the proposed decimation filter in terms of critical path delay and area are tabulated

Fixed point dual carrier modulation performance for wireless USB

Dual Carrier Modulation (DCM) is currently used as the higher data rate modulation scheme for Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) in the ECMA-368 defined Ultra-Wideband (UWB) radio platform. ECMA-368 has been chosen as the physical radio platform for many systems including Wireless USB (W-USB), Bluetooth 3.0 and Wireless HDMI; hence ECMA-368 is an important issue to consumer electronics and the user’s experience of these products. In this paper, Log Likelihood Ratio (LLR) demapping method is used for the DCM demaper implemented in fixed point model. Channel State Information (CSI) aided scheme coupled with the band hopping information is used as the further technique to improve the DCM demapping performance. The receiver performance for the fixed point DCM is simulated in realistic multi-path environments.

Dual carrier modulation demapping methods and performances for wireless USB

Dual Carrier Modulation (DCM) was chosen as the higher data rate modulation scheme for MB-OFDM (Multiband Orthogonal Frequency Division Multiplexing) in the UWB (Ultra-Wide Band) radio platform ECMA-368. ECMA-368 has been chosen as the physical implementation for high data rate Wireless USB (W-USB) and Bluetooth 3.0. In this paper, different demapping methods for the DCM demapper are presented, being Soft Bit, Maximum Likely (ML) Soft Bit and Log Likelihood Ratio (LLR). Frequency diversity and Channel State Information (CSI) are further techniques to enhance demapping methods. The system performance for those DCM demapping methods simulated in realistic multi-path environments are provided and compared.

Algorithms for autonomous tandem operation of a dual M113 system

In mid-July 2003, the U.S. Army Tank-Automotive & Armaments Command (TACOM) performed a series of experiments at Keweenaw Research Center (KRC), with a remote operated mine roller system. This system, named Panther Lite, consists of two M113 Armored Personnel Carriers (APC’s) connected by a Tandem Vehicle Linkage Assembly (TVLA). The system has three sets of mine rollers, two of which are connected to the front of the lead vehicle with one set trailing from the trail vehicle. Currently, the system requires two joystick controllers. One regulates the braking of the tracks, throttle, and transmission of the lead vehicle and the other controls the braking and throttle of the rear vehicle. One operator controls both joysticks, attempting to maneuver the lead vehicle along a desired path. At the same time, this operator makes compensation maneuvers to reduce lateral loads in the TVLA and to guide the rear mine rollers along the desired path. The purpose of this project is to create algorithms that would allow the slave (trail) vehicle to operate using inputs that maneuver the control (lead) vehicle. The project will be completed by first reconstructing the experimental data. Kinematic models will be generated and simulations created. The models will then be correlated with the reconstructions of the experimental data. The successful completion of this project will be a first step to eliminating the need for the second joystick.

Governor Tom Judge: Early Years - The Path to Becoming Montana's 18th Governor -- Sidney Armstrong, Larry Pettit & Kent Kleinkopf “In the Crucible of Change”

The dramatic period of progressive change in Montana that is documented "In the Crucible of Change" series really exploded with the election of Governors Forrest Anderson and Tom Judge. Anderson's single term saw the dispatching of the sales tax as an issue for a long period, the reorganization of the executive branch of state government and the revision of Montana's Constitution. As a former legislator, county attorney, Supreme Court justice, and Attorney General, Anderson brought unmatched experience to the governorship when elected. Tom Judge, although much younger (elected MT’s youngest governor at age 38 immediately following Anderson), also brought serious experience to the governorship: six years as a MT State Representative, two years as a MT State Senator, four years is Lieutenant Governor and significant business experience. The campaign and election of John F. Kennedy in 1960 spurred other young Americans to service, including Tom Judge. First elected in 1960, he rose rapidly through MT’s political-governmental hierarchy until he took over the governorship in time to implement many of the changes started in Governor Anderson’s term. But as a strong progressive leader in his own right, Governor Judge sponsored and implemented significant advancements of his own for Montana. Those accomplishments, however, are the subject of other films in this series. This film deals with Tom Judge’s early years – his rise to the governorship from when he returned home after college at Notre Dame and newspaper experience in Kentucky to his actual election in November 1972. That story is discussed in this episode by three major players in the effort, all directly involved in Tom Judge’s early years and path to the governorship: Sidney Armstrong, Larry Pettit and Kent Kleinkopf. Their recollections of the early Tom Judge and the period of his advancement to the governorship provide an insider’s perspective of the growth of this significant leader of the important period of progressive change documented “In the Crucible of Change.” Sidney Armstrong, President of Sidney Armstrong Consulting, serves on the board and as the Executive Director of the Greater Montana Foundation. Formerly Executive Director of the Montana Community Foundation (MCF), she has served on national committees and participated in national foundation initiatives. While at MCF, she worked extensively with MT Governors Racicot and Martz on the state charitable endowment tax credit and other endowed philanthropy issues. A member of MT Governor Thomas L. Judge’s staff in the 1970s, she was also part of Governor Brian Schweitzer’s 2004 Transition Team, continuing to serve as a volunteer advisor during his term. In the 1980s, Sidney also worked for the MT State AFL-CIO and the MT Democratic Party as well as working two sessions with the MT Senate as Assistant Secretary of the Senate and aide to the President. A Helena native, and great granddaughter of pioneer Montanans, Sidney has served on numerous nonprofit boards, and is currently a board member for the Montana History Foundation. Recently she served on the board of the Holter Museum of Art and was a Governor’s appointee to the Humanities Montana board. She is a graduate of the International School of Geneva, Switzerland and the University of Montana. Armstrong's Irish maternal immigrant great-grandparents, Thomas and Maria Cahill Cooney, came to Virginia City, MT in a covered wagon in 1865, looking for gold. Eventually, they settled on the banks of the Missouri River outside Helena as ranchers. She also has roots in Butte, MT, where her journalist father's family, both of whom were newspaper people, lived. Her father, Richard K. O’Malley, is also the author of a well-known book about Butte, Mile High, Mile Deep, recently re-published by Russell Chatham. She is the mother of four and the grandmother of eight. Dr. Lawrence K. Pettit (Larry Pettit) (b. 5/2/1937) has had a dual career in politics and higher education. In addition to being Montana’s first Commissioner of Higher Education (the subject of another film in this series); Pettit, of Lewistown, served as legislative assistant to U.S. Senators James E. Murray and Lee Metcalf, campaign manager, head of transition team and assistant to Montana Governor Thomas L. Judge; taught political science at The Pennsylvania State University (main campus), was chair of political science at Montana State University, Deputy Commissioner for Academic Programs at the Texas Higher Education Coordinating Board, Chancellor of the University System of South Texas (since merged with Texas A&M University), President of Southern Illinois University, and President of Indiana University of Pennsylvania from where he retired in 2003. He has served as chair of the Commission on Leadership for the American Council on Education, president of the National Association of (University) System Heads, and on many national and state boards and commissions in higher education. Pettit is author of “If You Live by the Sword: Politics in the Making and Unmaking of a University President.” More about Pettit is found at http://www.lawrencekpettit.com… Kent Kleinkopf of Missoula is co-founder of a firm with a national scope of business that specializes in litigation consultation, expert vocational testimony, and employee assistance programs. His partner (and wife of 45 years) Kathy, is an expert witness in the 27 year old business. Kent received a BA in History/Education from the University of Idaho and an MA in Economics from the University of Utah. The Kleinkopfs moved to Helena, MT in 1971 where he was Assistant to the Commissioner of State Lands (later Governor) Ted Schwinden. In early 1972 Kent volunteered full time in Lt. Governor Tom Judge’s campaign for Governor, driving the Lt. Governor extensively throughout Montana. After Judge was elected governor, Kent briefly joined the staff of Governor Forrest Anderson, then in 1973 transitioned to Judge’s Governor’s Office staff, where he became Montana’s first “Citizens’ Advocate.” In that capacity he fielded requests for assistance from citizens with concerns and information regarding State Agencies. While on the Governor’s staff, Kent continued as a travel aide with the governor both in Montana and nationally. In 1977 Kent was appointed Director of the MT Department of Business Regulation. That role included responsibility as Superintendent of Banking and Chairman of the State Banking Board, where Kent presided over the chartering of many banks, savings and loans, and credit unions. In 1981 the Kleinkopfs moved to Missoula and went into the business they run today. Kent was appointed by Governor Brian Schweitzer to the Board of the Montana Historical Society in 2006, was reappointed and continues to serve. Kathy and Kent have a daughter and son-in-law in Missoula.

DUAL ENERGY COMPUTED TOMOGRAPHY FOR PROTON THERAPY TREATMENT PLANNING

Proton radiation therapy is gaining popularity because of the unique characteristics of its dose distribution, e.g., high dose-gradient at the distal end of the percentage-depth-dose curve (known as the Bragg peak). The high dose-gradient offers the possibility of delivering high dose to the target while still sparing critical organs distal to the target. However, the high dose-gradient is a double-edged sword: a small shift of the highly conformal high-dose area can cause the target to be substantially under-dosed or the critical organs to be substantially over-dosed. Because of that, large margins are required in treatment planning to ensure adequate dose coverage of the target, which prevents us from realizing the full potential of proton beams. Therefore, it is critical to reduce uncertainties in the proton radiation therapy. One major uncertainty in a proton treatment is the range uncertainty related to the estimation of proton stopping power ratio (SPR) distribution inside a patient. The SPR distribution inside a patient is required to account for tissue heterogeneities when calculating dose distribution inside the patient. In current clinical practice, the SPR distribution inside a patient is estimated from the patient’s treatment planning computed tomography (CT) images based on the CT number-to-SPR calibration curve. The SPR derived from a single CT number carries large uncertainties in the presence of human tissue composition variations, which is the major drawback of the current SPR estimation method. We propose to solve this problem by using dual energy CT (DECT) and hypothesize that the range uncertainty can be reduced by a factor of two from currently used value of 3.5%. A MATLAB program was developed to calculate the electron density ratio (EDR) and effective atomic number (EAN) from two CT measurements of the same object. An empirical relationship was discovered between mean excitation energies and EANs existing in human body tissues. With the MATLAB program and the empirical relationship, a DECT-based method was successfully developed to derive SPRs for human body tissues (the DECT method). The DECT method is more robust against the uncertainties in human tissues compositions than the current single-CT-based method, because the DECT method incorporated both density and elemental composition information in the SPR estimation. Furthermore, we studied practical limitations of the DECT method. We found that the accuracy of the DECT method using conventional kV-kV x-ray pair is susceptible to CT number variations, which compromises the theoretical advantage of the DECT method. Our solution to this problem is to use a different x-ray pair for the DECT. The accuracy of the DECT method using different combinations of x-ray energies, i.e., the kV-kV, kV-MV and MV-MV pair, was compared using the measured imaging uncertainties for each case. The kV-MV DECT was found to be the most robust against CT number variations. In addition, we studied how uncertainties propagate through the DECT calculation, and found general principles of selecting x-ray pairs for the DECT method to minimize its sensitivity to CT number variations. The uncertainties in SPRs estimated using the kV-MV DECT were analyzed further and compared to those using the stoichiometric method. The uncertainties in SPR estimation can be divided into five categories according to their origins: the inherent uncertainty, the DECT modeling uncertainty, the CT imaging uncertainty, the uncertainty in the mean excitation energy, and SPR variation with proton energy. Additionally, human body tissues were divided into three tissue groups – low density (lung) tissues, soft tissues and bone tissues. The uncertainties were estimated separately because their uncertainties were different under each condition. An estimate of the composite range uncertainty (2s) was determined for three tumor sites – prostate, lung, and head-and-neck, by combining the uncertainty estimates of all three tissue groups, weighted by their proportions along typical beam path for each treatment site. In conclusion, the DECT method holds theoretical advantages in estimating SPRs for human tissues over the current single-CT-based method. Using existing imaging techniques, the kV-MV DECT approach was capable of reducing the range uncertainty from the currently used value of 3.5% to 1.9%-2.3%, but it is short to reach our original goal of reducing the range uncertainty by a factor of two. The dominant source of uncertainties in the kV-MV DECT was the uncertainties in CT imaging, especially in MV CT imaging. Further reduction in beam hardening effect, the impact of scatter, out-of-field object etc. would reduce the Hounsfeld Unit variations in CT imaging. The kV-MV DECT still has the potential to reduce the range uncertainty further.

La unidad de lo dual : tradición y modernidad en la obra de Tadao Ando y Toyo Ito

La referencia a la tradición como una fuerza capaz de aportar unidad, al abarcar tanto la continuidad como los cambios en las expresiones al margen de la época o las técnicas empleadas, ha sido siempre un componente muy importante de las manifestaciones artísticas de Japón y es la sutil ligazón que las conecta desde el pasado hasta la actualidad. Se entiende aquí que tradición no equivale simplemente a preservación, sino que se trata de una transmisión con una vertiente dual, pues permite una constante evolución sin que se altere su esencia básica. Es de esta forma que la cultura japonesa de la era Edo (1600-1868), con su alto grado de innovación, riqueza y sofisticación, pero además como epílogo histórico previo a la Restauración Meiji de 1868, ha sido la referencia clave en lo relativo a esa mirada a la tradición nipona para el desarrollo de esta tesis. A partir de la segunda mitad del siglo XIX, todas estas características tan genuinas del período Edo quedaron en suspenso y, desde entonces, Japón ha seguido la vía de la modernización (que en muchos aspectos ha sido también la de la occidentalización). Los entrelazamientos de otras dualidades provocados en Japón por los ataques nucleares de 1945 condujeron a una inevitable fusión de aquel mundo físico con el mundo metafísico, de aquella terrible presencia con un tremendo sentimiento de ausencia y, en definitiva, de Oriente con Occidente. El consiguiente impacto sobre la cultura de la nación tuvo una especial repercusión en el ámbito arquitectónico. En este sentido, el pensamiento francés ha desempeñado un papel fundamental en el replanteamiento radical de muchos supuestos esenciales, de muchos conceptos y valores de la cultura occidental, incluyendo los procedentes de la Ilustración, en este mundo contemporáneo que es cada vez más complejo y plural. Éstos y otros hechos otorgan a la cultura japonesa tradicional una cualidad multidimensional (frente a la marcada bidimensionalidad que suele caracterizar a las culturas occidentales) que, tal y como esta tesis doctoral pretende poner de manifiesto, podría revelarse como una «síntesis de contradicciones» en la obra de los arquitectos japoneses Tadao Ando (Osaka, 1941-) y Toyo Ito (Keijo, actual Seúl, 1941-). En el pensamiento oriental una dualidad es entendida como la complementariedad entre dos polos, sólo en apariencia opuestos, que integra dos vertientes de un único concepto. Al igual que la idea de «parejas» budista, concebida según esta doctrina como una unidad entre dos extremos inevitablemente interrelacionados, el objetivo principal sería el de poner de manifiesto cómo la obra de ambos arquitectos trata de resolver los mismos conflictos partiendo de puntos de vista polarizados. ABSTRACT The reference to tradition as a force for unity, encompassing both continuity and changes in expressions regardless of the time or techniques used, has always been a very important component of the artistic manifestations of Japan and it is the subtle link that connects them from the past to the present. It is understood here that tradition does not mean simply preservation, but it is a transmission with a dual aspect, because it allows a constant evolution without altering its basic essence. It is thus that the Japanese culture of the Edo era (1600-1868), with its high degree of innovation, wealth and sophistication, but also as a historical epilogue prior to the Meiji Restoration of 1868 has been the key reference concerning that look to the Japanese tradition for the development of this thesis. From the second half of the 19th century, all these as genuine features of the Edo period remained at a standstill and, since then, Japan has followed the path of modernization (which has also been that of Westernization in many ways). The interlacements of other dualities caused in Japan by the 1945 nuclear attacks led to an inevitable fusion of the physical with the metaphysical world, of that terrible presence with a tremendous sense of absence and, eventually, of East with West. The resulting impact on the culture of the nation had a special repercussion on the architectural field. In this sense, the French thought has played a key role in the radical rethinking of many core assumptions, many concepts and values of Western thought, including those from the Age of Enlightenment, in this contemporary world that is increasingly complex and plural. These and other facts give the traditional Japanese culture a multidimensional quality (opposed to the marked two-dimensionality that usually characterizes Western cultures). As this thesis aims to highlight, this could prove to be a «synthesis of contradictions» in the work of Japanese architects Tadao Ando (Osaka, 1941-) and Toyo Ito (Keijo, current Seoul, 1941-). In the Eastern thought a duality is understood as the complementarity between two poles, only apparently opposite, which integrates two aspects of a single concept. Like the Buddhist notion of «couples» (conceived according to this doctrine as a unity between two inevitably interlinked extremes) the main objective would be to show how the work of both architects tries to resolve the same conflicts starting with polarized viewpoints.

Long-term potentiation and dual-component quantal signaling in the dentate gyrus

Long-term potentiation (LTP) of excitatory transmission is an important candidate cellular mechanism for the storage of memories in the mammalian brain. The subcellular phenomena that underlie the persistent increase in synaptic strength, however, are incompletely understood. A potentially powerful method to detect a presynaptic increase in glutamate release is to examine the effect of LTP induction on the rate at which the use-dependent blocker MK-801 attenuates successive N-methyl-d-aspartic acid (NMDA) receptor-mediated synaptic signals. This method, however, has given apparently contradictory results when applied in hippocampal CA1. The inconsistency could be explained if NMDA receptors were opened by glutamate not only released from local presynaptic terminals, but also diffusing from synapses on neighboring cells where LTP was not induced. Here we examine the effect of pairing-induced LTP on the MK-801 blocking rate in two afferent inputs to dentate granule cells. LTP in the medial perforant path is associated with a significant increase in the MK-801 blocking rate, implying a presynaptic increase in glutamate release probability. An enhanced MK-801 blocking rate is not seen, however, in the lateral perforant path. This result still could be compatible with a presynaptic contribution to LTP in the lateral perforant path if intersynaptic cross-talk occurred. In support of this hypothesis, we show that NMDA receptors consistently sense more quanta of glutamate than do α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. In the medial perforant path, in contrast, there is no significant difference in the number of quanta mediated by the two receptors. These results support a presynaptic contribution to LTP and imply that differences in intersynaptic cross-talk can complicate the interpretation of experiments designed to detect changes in transmitter release.

Interface Between Intellectual Disability And Mental Health: Hermeneutic Review.

A literature review was conducted aiming to understand the interface between the Intellectual Disability and Mental Health fields and to contribute to mitigating the path of institutionalizing individuals with intellectual deficiencies. The so-called dual diagnosis phenomenon remains underestimated in Brazil but is the object of research and specific public policy internationally. This phenomenon alerts us to the prevalence of mental health problems in those with intellectual disabilities, limiting their social inclusion. The findings reinforce the importance of this theme and indicate possible diagnostic invisibility of the development of mental illness in those with intellectual disabilities in Brazil, which may contribute to sustaining psychiatric institutionalization of this population. 

Obstacle Crossing With Dual Tasking Is A Danger For Individuals With Alzheimer's Disease And For Healthy Older People.

The aim of this study was to analyze the effects of dual tasking on obstacle crossing during walking by individuals with Alzheimer's disease (AD) and by healthy older people. Thirty four elderly individuals (16 healthy subjects and 18 individuals with AD) were recruited to participate in this study. Three AD individuals and one control participant were excluded due to exclusion criteria. The participants were instructed to walk barefoot at their own speed along an 8 m long pathway. Each participant performed five trials for each condition (unobstructed walking, unobstructed walking with dual tasking, and obstacle crossing during walking with dual tasking). The trials were completely randomized for each participant. The mid-pathway stride was measured in the unobstructed walking trials and the stride that occurred during the obstacle avoidance was measured in the trials that involved obstacle crossing. The behavior of the healthy elderly subjects and individuals with AD was similar for obstacle crossing during walking with dual tasking. Both groups used the posture first strategy to prioritize stability and showed decreased attention to executive tasking while walking. Additionally, AD had a strong influence on the modifications that are made by the elderly while walking under different walking conditions.

Morphological analysis of glass, carbon and glass/carbon fiber posts and bonding to self or dual-cured resin luting agents

OBJECTIVE: The aim of this study was to evaluate the morphology of glass (GF), carbon (CF) and glass/carbon (G/CF) fiber posts and their bond strength to self or dual-cured resin luting agents. MATERIAL AND METHODS: Morphological analysis of each post type was conducted under scanning electron microscopy (SEM). Bond strength was evaluated by microtensile test after bisecting the posts and re-bonding the two halves with the luting agents. Data were subjected to two-way ANOVA and Tukey's test (α=0.05). Failure modes were evaluated under optical microscopy and SEM. RESULTS: GF presented wider fibers and higher amount of matrix than CF, and G/CF presented carbon fibers surrounded by glass fibers, and both involved by matrix. For CF and GF, the dual-cured material presented significantly higher (p<0.05) bond strength than the self-cured agent. For the dual agent, CF presented similar bond strength to GF (p>0.05), but higher than that of G/CF (p<0.05). For the self-cured agent, no significant differences (p>0.05) were detected, irrespective of the post type. For GF and G/CF, all failures were considered mixed, while a predominance of adhesive failures was detected for CF. CONCLUSION: The bonding between fiber posts and luting agents was affected by the type of fibers and polymerization mode of the cement. When no surface treatment of the post is performed, the bonding between glass fiber post and dual-cured agent seems to be more reliable.

Production and body composition traits of broilers in relation to breast weight evaluated by path analysis

Breast weight has great economic importance in poultry industry, and may be associated with other variables. This work aimed to estimate phenotypic correlations between performance (live body weight at 7 and 28 days, and at slaughter, and depth of the breast muscle measured by ultrasonography), carcass (eviscerated body weight and leg weight) and body composition (heart, liver and abdominal fat weight) traits in a broiler line, and quantify the direct and indirect influence of these traits on breast weight. Path analysis was used by expanding the matrix of partial correlation in coefficients which give the direct influence of one trait on another, regardless the effect of the other traits. The simultaneous maintenance of live body weight at slaughter and eviscerated body weight in the matrix of correlations might be harmful for statistical analysis involving systems of normal equations, like path analysis, due to the observed multicollinearity. The live body weight at slaughter and the depth of the breast muscle as measured by ultrasonography directly affected breast weight and were identified as the most responsible factors for the magnitude of the correlation coefficients obtained between the studied traits and breast weight. Individual pre-selection for these traits could favor an increased breast weight in the future reproducer candidates of this line if the broilers' environmental conditions and housing are maintained, since the live body weight at slaughter and the depth of breast muscle measured by ultrasonography were directly related to breast weight.