940 resultados para One Up Bond F


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The structure and spin-crossover magnetic behavior of [FeII16][BF4]2 (1 = isoxazole) and [FeII16][ClO4]2 have been studied. [FeII16][BF4]2 undergoes two reversible spin-crossover transitions at 91 and 192 K, and is the first two-step spin transition to undergo a simultaneous crystallographic phase transition, but does not exhibit thermal hysteresis. The single-crystal structure determinations at 260 [space group P3̄, a = 17.4387(4) Å, c = 7.6847(2) Å] and at 130 K [space group P1̄, a = 17.0901(2) Å, b = 16.7481(2) Å, c = 7.5413(1) Å, α = 90.5309(6)°, β = 91.5231(6)°, γ = 117.8195(8)°] reveal two different iron sites, Fe1 and Fe2, in a 1:2 ratio. The room-temperature magnetic moment of 5.0 μB is consistent with high-spin Fe(II). A plateau in μ(T) having a moment of 3.3 μB centered at 130 K suggests a mixed spin system of some high-spin and some low-spin Fe(II) molecules. On the basis of the Fe−N bond distances at the two temperatures, and the molar fraction of high-spin molecules at the transition plateau, Fe1 and Fe2 can be assigned to the 91 and 192 K transitions, respectively. [FeII16][ClO4]2 [space group P3̄, a = 17.5829(3) Å, c = 7.8043(2) Å, β = 109.820 (3)°, T = 295 K] also possesses Fe1:Fe2 in a 1:2 ratio, and magnetic measurements show a single spin transition at 213 K, indicating that both Fe1 and Fe2 undergo a simultaneous spin transition. [FeII16][ClO4]2 slowly decomposes in solutions containing acetic anhydride to form [FeIII3O(OAc)613][ClO4] [space group I2, a = 10.1547(7) Å, b = 16.5497(11) Å, c = 10.3205(9) Å, β = 109.820 (3)°, T = 200 K]. The isosceles Fe3 unit contains two Fe···Fe distances of 3.2844(1) Å and a third Fe···Fe distance of 3.2857(1) Å. The magnetic data can be fit to a trinuclear model with ℋ = −2J(S1·S2 + S2·S3) − 2J13(S1·S3), where J = −27.1 and J13 = −32.5 cm-1.

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Up to a third of patients do not respond to their first antidepressant and many remain depressed despite multiple treatments. Combining antidepressants is one strategy recommended for patients who respond inadequately to initial treatment and in this article Celia Feetam discusses the evidence for this approach. © 2012 John Wiley & Sons, Ltd.

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In this paper, we investigate the design of few-mode fibers (FMFs) guiding 4 to 12 non-degenerate linearly polarized (LP) modes with low differential mode delay (DMD) over the C-band, suitable for long-haul transmission. The refractive index profile considered is composed by a graded-core with a cladding trench (GCCT). The optimization of the profile parameters aims the lowest possible DMD and macro-bend losses (MBL) lower than the ITU-T standard recommendation. The optimization results show that the optimum DMD and the MBL scale with the number of modes. Additionally, it is shown that the refractive-index relative difference at the core center is one of the most preponderant parameters, allowing to reduce the DMD at the expense of increasing MBL. Finally, the optimum DMD obtained for 12 LP modes is lower than 3 ps/km. © 2014 IEEE.

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Three experiments investigated the dynamics of auditory stream segregation. Experiment 1 used a 2.0-s constant-frequency inducer (10 repetitions of a low-frequency pure tone) to promote segregation in a subsequent, 1.2-s test sequence of alternating low- and high-frequency tones. Replacing the final inducer tone with silence reduced reported test-sequence segregation substantially. This reduction did not occur when either the 4th or 7th inducer was replaced with silence. This suggests that a change at the induction/test-sequence boundary actively resets buildup, rather than less segregation occurring simply because fewer inducer tones were presented. Furthermore, Experiment 2 found that a constant-frequency inducer produced its maximum segregation-promoting effect after only 3 tone cycles - this contrasts with the more gradual build-up typically observed for alternating sequences. Experiment 3 required listeners to judge continuously the grouping of 20-s test sequences. Constant-frequency inducers were considerably more effective at promoting segregation than alternating ones; this difference persisted for ∼10 s. In addition, resetting arising from a single deviant (longer tone) was associated only with constant-frequency inducers. Overall, the results suggest that constant-frequency inducers promote segregation by capturing one subset of test-sequence tones into an on-going, pre-established stream and that a deviant tone may reduce segregation by disrupting this capture. © 2013 Acoustical Society of America.

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Why are some entrepreneurs able to start a new firm more quickly than others in the venture creation process? Drawing on pecking order and agency theory, this study investigates how start-up capital structure influences the time to either new firm founding or quitting the start-up process. The temporal aspect of the start-up process is one that is often discussed, but rarely studied. Therefore, we utilize competing risk and Cox regression event history analysis on a nationally representative sample of US entrepreneurs to investigate how start-up capital structure impacts the time in gestation to particular kinds of start-up outcomes. Our findings suggest that external equity has an appreciable impact on new firm emergence over time, and that the percentage of ownership held by the founders attenuates the benefits of external equity.

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This paper studies the Spanish fictional novel by Andrés Barba, Ahora tocad música de baile (2004), one of the first cultural texts dealing entirely with Alzheimer’s disease (AD) to appear in Spain. It argues that the significance of Barba’s fictional novel rests on two important issues: the ethics of representation of violence against vulnerable subjects and the ethics of care. The paper analyses how these two issues allow Barba to create a story in which the verbal and physical abuse to which the person living with Alzheimer’s disease is subjected places the reader, on the one hand, as voyeur/witness of the abuse; and, on the other, as interpreter, and ultimately judge, of the fine line that separates euthanasia, assisted suicide, and murder. The open ending of the novel defers all ethical and moral judgment to the reader. It examines how the novel offers a monolithic perspective about AD, in which care is presented as a burden. In fact, this study shows that the novel’s multi-layered structure and polyphonic nature places the emphasis on stigmas, stereotypes and negative metaphors around AD, as found in contemporary social discourses.

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The cell:cell bond between an immune cell and an antigen presenting cell is a necessary event in the activation of the adaptive immune response. At the juncture between the cells, cell surface molecules on the opposing cells form non-covalent bonds and a distinct patterning is observed that is termed the immunological synapse. An important binding molecule in the synapse is the T-cell receptor (TCR), that is responsible for antigen recognition through its binding with a major-histocompatibility complex with bound peptide (pMHC). This bond leads to intracellular signalling events that culminate in the activation of the T-cell, and ultimately leads to the expression of the immune eector function. The temporal analysis of the TCR bonds during the formation of the immunological synapse presents a problem to biologists, due to the spatio-temporal scales (nanometers and picoseconds) that compare with experimental uncertainty limits. In this study, a linear stochastic model, derived from a nonlinear model of the synapse, is used to analyse the temporal dynamics of the bond attachments for the TCR. Mathematical analysis and numerical methods are employed to analyse the qualitative dynamics of the nonequilibrium membrane dynamics, with the specic aim of calculating the average persistence time for the TCR:pMHC bond. A single-threshold method, that has been previously used to successfully calculate the TCR:pMHC contact path sizes in the synapse, is applied to produce results for the average contact times of the TCR:pMHC bonds. This method is extended through the development of a two-threshold method, that produces results suggesting the average time persistence for the TCR:pMHC bond is in the order of 2-4 seconds, values that agree with experimental evidence for TCR signalling. The study reveals two distinct scaling regimes in the time persistent survival probability density prole of these bonds, one dominated by thermal uctuations and the other associated with the TCR signalling. Analysis of the thermal fluctuation regime reveals a minimal contribution to the average time persistence calculation, that has an important biological implication when comparing the probabilistic models to experimental evidence. In cases where only a few statistics can be gathered from experimental conditions, the results are unlikely to match the probabilistic predictions. The results also identify a rescaling relationship between the thermal noise and the bond length, suggesting a recalibration of the experimental conditions, to adhere to this scaling relationship, will enable biologists to identify the start of the signalling regime for previously unobserved receptor:ligand bonds. Also, the regime associated with TCR signalling exhibits a universal decay rate for the persistence probability, that is independent of the bond length.

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We present a review of the latest developments in one-dimensional (1D) optical wave turbulence (OWT). Based on an original experimental setup that allows for the implementation of 1D OWT, we are able to show that an inverse cascade occurs through the spontaneous evolution of the nonlinear field up to the point when modulational instability leads to soliton formation. After solitons are formed, further interaction of the solitons among themselves and with incoherent waves leads to a final condensate state dominated by a single strong soliton. Motivated by the observations, we develop a theoretical description, showing that the inverse cascade develops through six-wave interaction, and that this is the basic mechanism of nonlinear wave coupling for 1D OWT. We describe theory, numerics and experimental observations while trying to incorporate all the different aspects into a consistent context. The experimental system is described by two coupled nonlinear equations, which we explore within two wave limits allowing for the expression of the evolution of the complex amplitude in a single dynamical equation. The long-wave limit corresponds to waves with wave numbers smaller than the electrical coherence length of the liquid crystal, and the opposite limit, when wave numbers are larger. We show that both of these systems are of a dual cascade type, analogous to two-dimensional (2D) turbulence, which can be described by wave turbulence (WT) theory, and conclude that the cascades are induced by a six-wave resonant interaction process. WT theory predicts several stationary solutions (non-equilibrium and thermodynamic) to both the long- and short-wave systems, and we investigate the necessary conditions required for their realization. Interestingly, the long-wave system is close to the integrable 1D nonlinear Schrödinger equation (NLSE) (which contains exact nonlinear soliton solutions), and as a result during the inverse cascade, nonlinearity of the system at low wave numbers becomes strong. Subsequently, due to the focusing nature of the nonlinearity, this leads to modulational instability (MI) of the condensate and the formation of solitons. Finally, with the aid of the probability density function (PDF) description of WT theory, we explain the coexistence and mutual interactions between solitons and the weakly nonlinear random wave background in the form of a wave turbulence life cycle (WTLC).

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Close-Up of Charles and Betty Perry in their Palm Beach Home. Charles Edward Perry (Chuck), 1937-1999, was the founding president of Florida International University in Miami, Florida. He grew up in Logan County, West Virginia and received his bachelor's and masters's degrees from Bowling Green State University. He married Betty Laird in 1960. In 1969, at the age of 32, Perry was the youngest president of any university in the nation. The name of the university reflects Perry’s desire for a title that would not limit the scope of the institution and would support his vision of having close ties to Latin America. Perry and a founding corps opened FIU to 5,667 students in 1972 with only one large building housing six different schools. Perry left the office of President of FIU in 1976 when the student body had grown to 10,000 students and the university had six buildings, offered 134 different degrees and was fully accredited. Charles Perry died on August 30, 1999 at his home in Rockwall, Texas. He is buried on the FIU campus in front of the Graham Center entrance. Betty Laird Perry was born Betty Laird in Ashland, Ohio. She attended Akron General Hospital School of Nursing, where she was the president of the Akron, Ohio TriCity Student Government Association. She received a 3 year diploma in nursing in 1960 and took her state board exams for licensure as an RN that same year. Ultimately, she became licensed in Ohio, Florida and Texas. She met Charles Perry in 1959 and the couple married on September 17, 1960, in Ashland, Ohio; the same week of her graduation. Betty began her nursing career at the Bowling Green State University campus Health Center while Chuck worked on the Admissions staff. In 1974, Mrs. Perry received her BSN from Florida International University and in 1985 she earned a Master's Degree in Healthcare Policy and Planning from Georgia State University. She went on to start her own business, BC Golf, Ltd., in 1992 where she was recognized by Cambridge’s Who's Who for demonstrating dedication, leadership and excellence in business management. Betty’s passion for art is reflected in the Student Art Award at Florida International University which she and Charles Perry started. In 2010-2011, Betty made a generous donation to the Patricia & Phillip Frost Art Museum Building Fund at Florida International University where she has a gallery named in her honor that is dedicated to student, faculty, and alumni exhibitions.

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It may soon be the norm for many airline passengers arriving at the check-in desk of any international airline with both stow- away and carry-on luggage to be asked to step onto the weighing scale as the airlines attempt to compete and remain operationally viable in what has become for most a cut-throat and highly litigious operating environment. The author's commentary seeks to highlight a number of the issues surrounding the current impasse. It is also intended to catalyze a more healthy and informed debate aimed at finding an acceptable resolution to this crisis prior to one being imposed which fails to satisfy the needs of either camp.

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This dissertation examined the long-term efficacy (8-to-13 years, M = 9.54, SD = 1.689) of exposure-based cognitive-behavioral therapy (CBT) for phobic and anxiety disorders in youths. Long-term efficacy was examined in terms of diagnostic recovery, symptom reductions, and clinically significant change. This dissertation also examined predictors of long-term efficacy (e.g., age, gender, and other clinical characteristics) as well as the relative long-term efficacy of CBT for Hispanic/Latino and European American youth. ^ Participants consisted of 67 youth (age range 15–26 years; M = 19.43, SD = 3.02 years at time of follow-up assessment), (47.8% females, 37.3% Hispanic/Latino) who had participated in one of two clinical trials (Silverman et al., 1999a, b). After providing informed consent to participate in the long term follow-up, youths completed a diagnostic interview and a battery of questionnaires. Results indicated that treatment gains were maintained about 9.5 years after treatment was completed. Maintenance of treatment gains was evident in terms of diagnostic recovery, symptom reductions, and clinically significant change. Long-term treatment gains extended to both ethnic groups and the two ethnic groups were functionally equivalent along most indices examined. Analyses of predictors of long-term outcome showed that parent self-reported pre-treatment depression, youth-reported pre-treatment depression, and youths retrospective reports of negative life events were significantly associated with less favorable long-term gains in terms of total symptoms of anxiety at long-term follow-up. In terms of long-term sequelae, youths with less successful post-treatment outcomes reported seeking-out additional treatment as well as using/abused substances and substance dependence significantly more than youths with successful post-treatment outcomes. Results are discussed in terms of the contribution of the present study to knowledge base about the long-term efficacy of exposure-based CBT procedures for phobic and anxiety disorders in youth. Findings also are discussed in terms of the need to modify CBT procedures to target youths with less successful post-treatment outcomes. Limitations and future directions are presented. ^

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Bonded repair of concrete structures with fiber reinforced polymer (FRP) systems is increasingly being accepted as a cost-efficient and structurally viable method of rapid rehabilitation of concrete structures. However, the relationships between long-term performance attributes, service-life, and details of the installation process are not easy to quantify. Accordingly, there is currently a lack of generally accepted construction specifications, making it difficult for the field engineer to certify the adequacy of the construction process. ^ The objective of the present study, as part of the National Cooperative Highway Research Program (NCHRP) Project 10-59B, was to investigate the effect of surface preparation on the behavior of wet lay-up FRP repair systems and consequently develop rational thresholds that provide sufficient performance. ^ The research program was comprised of both experimental and analytical work for wet lay-up FRP applications. The experimental work included flexure testing of sixty-seven (67) reinforced concrete beams and bond testing of ten (10) reinforced concrete blocks. Four different parameters were studied: surface roughness, surface flatness, surface voids and bug holes, and surface cracks/cuts. The findings were analyzed from various aspects and compared with the data available in the literature. As part of the analytical work, finite element models of the flexural specimens with surface flaws were developed using ANSYS. The purpose of this part was to extend the parametric study on the effects of concrete surface flaws and verify the experimental results based on nonlinear finite element analysis. ^ Test results showed that surface roughness does not appear to have a significant influence on the overall performance of the wet lay-up FRP systems with or without adequate anchorage, and whether failure was by debonding or rupture of FRP. Both experimental and analytical results for surface flatness proved that peaks on concrete surface, in the range studied, do not have a significant effect on the performance of wet lay-up FRP systems. However, valleys of particular size could reduce the strength of wet lay-up FRP systems. Test results regarding surface voids and surface cracks/cuts revealed that previously suggested thresholds for these flaws appear to be conservative, as also confirmed by analytical study. ^

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Hydrogen has been considered as a potentially efficient and environmentally friendly alternative energy solution. However, one of the most important scientific and technical challenges that the "hydrogen economy" faces is the development of safe and economically viable on-board hydrogen storage for fuel cell applications, especially to the transportation sector. Ammonia borane (BH3NH 3), a solid state hydrogen storage material, possesses exceptionally high hydrogen content (19.6 wt%).However, a fairly high temperature is required to release all the hydrogen atoms, along with the emission of toxic borazine. Recently research interests are focusing on the improvement of H2 discharge from ammonia borane (AB) including lowering the dehydrogenation temperature and enhancing hydrogen release rate using different techniques. Till now the detailed information about the bonding characteristics of AB is not sufficient to understand details about its phases and structures. ^ Elemental substitution of ammonia borane produces metal amidoboranes. Introduction of metal atoms to the ammonia borane structure may alter the bonding characteristics. Lithium amidoborane is synthesized by ball milling of ammonia borane and lithium hydride. High pressure study of molecular crystal provides unique insight into the intermolecular bonding forces and phase stability. During this dissertation, Raman spectroscopic study of lithium amidoborane has been carried out at high pressure in a diamond anvil cell. It has been identified that there is no dihydrogen bond in the lithium amidoborane structure, whereas dihydrogen bond is the characteristic bond of the parent compound ammonia borane. It has also been identified that the B-H bond becomes weaker, whereas B-N and N-H bonds become stronger than those in the parent compound ammonia borane. At high pressure up to 15 GPa, Raman spectroscopic study indicates two phase transformations of lithium amidoborane, whereas synchrotron X-ray diffraction data indicates only one phase transformation of this material. ^ Pressure and temperature has a significant effect on the structural stability of ammonia borane. This dissertation explored the phase transformation behavior of ammonia borane at high pressure and low temperature using in situ Raman spectroscopy. The P-T phase boundary between the tetragonal (I4mm) and orthorhombic (Pmn21) phases of ammonia borane has been determined. The transition has a positive Clapeyron slope which indicates the transition is of exothermic in nature. Influence of nanoconfinemment on the I4mm to Pmn2 1 phase transition of ammonia borane was also investigated. Mesoporus silica scaffolds SBA-15 with pore size of ~8 nm and MCM-41 with pore size of 2.1-2.7 nm, were used to nanoconfine ammonia borane. During cooling down, the I4mm to Pmn21 phase transition was not observed in MCM-41 nanoconfined ammonia borane, whereas the SBA-15 nanocondfined ammonia borane shows the phase transition at ~195 K. Four new phases of ammonia borane were also identified at high pressure up to 15 GPa and low temperature down to 90 K.^

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The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

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Background: There have been no published studies observing what happens to children post hospital discharge and if medication discrepancies occurred between the hospital and General Practitioner (GP) interface.1 Objectives: To identify the type of discrepancies between hospital discharge prescription and the patient's medicines after their first GP prescription. Method: Over a 3 month period (March–June 2012) across two London NHS hospital sites, parents of children on long term medications aged 18 years and under, were approached and consented prior to discharge from the ward. The patients were followed up 21 days after discharge by telephone call or home visit depending on their preference. The parent was asked if they had contacted their GP for further medications during the follow up, and if not the follow up was rescheduled. The parents were interviewed to find out if there were any discrepancies that occurred post discharge by comparing the patient's hospital discharge letter and medication at follow up. All this information was captured on a data collection form. Results: Eighty-eight patients were consented and 60 patients (68%; 60/88) were followed up by telephone call 21 days post discharge. A total of 317 medications were ordered at discharge among the 60 patients. Of the 60 that were followed up, nine were lost to follow up, one died post discharge, one was excluded from the study, and 11 had not contacted the GP and were to be followed up at a later date. Of the 38 patients who were followed up, 254 medications were ordered. Of the 38 patients there were 12 (32%) patients who had discrepancies that occurred between the discharge letter and GP, 19 (50%) had no issues, and seven (18%) mentioned issues to do with post discharge that were not discrepancies. Of the 12 patients who had at least one medication discrepancy (total 34 medications, range 1–7 discrepancies per patient), six patients had GP discrepancies, four had discrepancies resulting from a hospital outpatient appointment, one related to the discharge letter order and one was a complex discrepancy. An example: a patient was discharged on amiodarone liquid 16.5 mg daily as opposed to 65 mg daily of amiodarone from the GP. Upon interview the parent used volume units to communicate dose as opposed to the actual dose itself and the strengths of liquid had changed. Conclusions: The preliminary results from the study have shown that discrepancies due to several causes occur when paediatric patients leave hospital.