The dynamics of brand loyalty across a consumer’s lifetime

This project studies the Portuguese female fashion market. We intend to determine patterns of consumer brand loyalty across brands and ages. By interviewing 8 young adults and surveying 125 teens and 87 adults, we found that brands’ segmentation by usage per age segment is related with differentiation in brand loyalty and peer pressure. We also found that teens have higher attitudinal brand loyalty while adults have higher behavioral loyalty. Moreover, brand loyalty in teens is more susceptible to peer pressure. The results imply that customer relationship management strategies should be differentiated according to age segment. We also derive marketing implications with a focus on each brand’s loyalty profile.

Modelling and Analysis of Bivariate Lifetime Data using Reversed Hazard Rates

Department of Statistics, Cochin University of Science and Technology

‘Reliability Concepts in Quantile-based Analysis of Lifetime Data

Reliability analysis is a well established branch of statistics that deals with the statistical study of different aspects of lifetimes of a system of components. As we pointed out earlier that major part of the theory and applications in connection with reliability analysis were discussed based on the measures in terms of distribution function. In the beginning chapters of the thesis, we have described some attractive features of quantile functions and the relevance of its use in reliability analysis. Motivated by the works of Parzen (1979), Freimer et al. (1988) and Gilchrist (2000), who indicated the scope of quantile functions in reliability analysis and as a follow up of the systematic study in this connection by Nair and Sankaran (2009), in the present work we tried to extend their ideas to develop necessary theoretical framework for lifetime data analysis. In Chapter 1, we have given the relevance and scope of the study and a brief outline of the work we have carried out. Chapter 2 of this thesis is devoted to the presentation of various concepts and their brief reviews, which were useful for the discussions in the subsequent chapters .In the introduction of Chapter 4, we have pointed out the role of ageing concepts in reliability analysis and in identifying life distributions .In Chapter 6, we have studied the first two L-moments of residual life and their relevance in various applications of reliability analysis. We have shown that the first L-moment of residual function is equivalent to the vitality function, which have been widely discussed in the literature .In Chapter 7, we have defined percentile residual life in reversed time (RPRL) and derived its relationship with reversed hazard rate (RHR). We have discussed the characterization problem of RPRL and demonstrated with an example that the RPRL for given does not determine the distribution uniquely

Race of a lifetime.

Una relación entre un hermano una hermana y la solución de conflictos. El pasatiempo favorito de Jamie es montar su bicicleta, también la utiliza para entregar los documentos para su empleo a tiempo parcial. Pero la bicicleta de Jamie está cayéndose a pedazos y mientras a él le encantaría comprar una nueva bicicleta de carreras, su familia no pueden pagarla. Un día, recibe un e-mail con un anuncio ofreciéndole una bicicleta de segunda mano y que sería perfecta para él. No podía haber sido más oportuno, ya que en el pueblo hay una carrera ciclista y le gustaría participar. Cuando a Jaime le roban la bicicleta, parece que él está fuera de la carrera.

Detection of frailty in Weibull lifetime data using Outlier tests

Heterogeneity in lifetime data may be modelled by multiplying an individual's hazard by an unobserved frailty. We test for the presence of frailty of this kind in univariate and bivariate data with Weibull distributed lifetimes, using statistics based on the ordered Cox-Snell residuals from the null model of no frailty. The form of the statistics is suggested by outlier testing in the gamma distribution. We find through simulation that the sum of the k largest or k smallest order statistics, for suitably chosen k , provides a powerful test when the frailty distribution is assumed to be gamma or positive stable, respectively. We provide recommended values of k for sample sizes up to 100 and simple formulae for estimated critical values for tests at the 5% level.

Fluorescence lifetime imaging microscopy (FLIM) to demonstrate the nuclear binding of flavanols and (--epigallocatechin gallate

The use of light microscopy and DMACA staining strongly suggested that plant and animal cell nuclei act as sinks for flavanols [1, 2]. Detailed uv-vis spectroscopic titration experiments indicated that histone proteins are the likely binding sites in the nucleus [2]. Here we report the development of a multi-photon excitation microscopy technique combined with fluorescent lifetime measurements of flavanols. Using this technique, (+) catechin, (-) epicatechin and (-) epigallocatechin gallate (EGCG) showed strikingly different excited state lifetimes in solution. Interaction of histone proteins with flavanols was indicated by the appearance of a significant τ2-component of 1.7 to 4.0ns. Tryptophan interference could be circumvented in the in vivo fluorescence lifetime imaging microscopy (FLIM) experiments with 2-photon excitation at 630nm. This enabled visualisation and semi-quantitative measurements that demonstrated unequivocally the absorption of (+)catechin, (-)epicatechin and EGCG by nuclei of onion cells. 3D FLIM revealed for the first time that externally added EGCG penetrated the whole nucleus in onion cells. The relative proportions of EGCG in cytoplasm: nucleus: nucleoli were ca. 1:10:100. FLIM experiments may therefore facilitate probing the health effects of EGCG, which is the major constituent of green tea.

Two-photon excitation with pico-second fluorescence lifetime imaging to detect nuclear association of flavanols

Two-photon excitation enabled for the first time the observation and measurement of excited state fluorescence lifetimes from three flavanols in solution, which were ∼1.0 ns for catechin and epicatechin, but <45 ps for epigallocatechin gallate (EGCG). The shorter lifetime for EGCG is in line with a lower fluorescence quantum yield of 0.003 compared to catechin (0.015) and epicatechin (0.018). In vivo experiments with onion cells demonstrated that tryptophan and quercetin, which tend to be major contributors of background fluorescence in plant cells, have sufficiently low cross sections for two-photon excitation at 630 nm and therefore do not interfere with detection of externally added or endogenous flavanols in Allium cepa or Taxus baccata cells. Applying two-photon excitation to flavanols enabled 3-D fluorescence lifetime imaging microscopy and showed that added EGCG penetrated the whole nucleus of onion cells. Interestingly, EGCG and catechin showed different lifetime behaviour when bound to the nucleus: EGCG lifetime increased from <45 to 200 ps, whilst catechin lifetime decreased from 1.0 ns to 500 ps. Semi-quantitative measurements revealed that the relative ratios of EGCG concentrations in nucleoli associated vesicles: nucleus: cytoplasm were ca. 100:10:1. Solution experiments with catechin, epicatechin and histone proteins provided preliminary evidence, via the appearance of a second lifetime (τ2 = 1.9–3.1 ns), that both flavanols may be interacting with histone proteins. We conclude that there is significant nuclear absorption of flavanols. This advanced imaging using two-photon excitation and biophysical techniques described here will prove valuable for probing the intracellular trafficking and functions of flavanols, such as EGCG, which is the major flavanol of green tea.

Cis–trans isomerism in diphenoxido bridged dicopper complexes: role of crystallized water to stabilize the cis isomer, variation in magnetic properties and conversion of both into a trinuclear species

The trans-[Cu2L2Cl2] (1), and cis-[Cu2L2Cl2]·H2O (2) isomers of a diphenoxido bridged Cu2O2 core have been synthesized using a tridentate reduced Schiff base ligand 2-[(2-dimethylamino-ethylamino)-methyl]-phenol. The geometry around Cu(II) is intermediate between square pyramid and trigonal bipyramid (Addison parameter, tau = 0.463) in 1 but nearly square pyramidal (tau = 0.049) in 2. The chloride ions are coordinated to Cu(II) and are trans oriented in 1 but cis oriented in 2. Both isomers have been optimized using density functional theory (DFT) calculations and it is found that the trans isomer is 7.2 kcal mol(-1) more favorable than the cis isomer. However, the hydrogen bonding interaction of crystallized water molecule with chloride ions compensates for the energy difference and stabilizes the cis isomer. Both complexes have been converted to a very rare phenoxido-azido bridged trinuclear species, [Cu3L2(mu(1,1)-N-3)(2)(H2O)(2)(ClO4)(2)] (3) which has also been characterized structurally. All the complexes are antiferromagnetically coupled but the magnitude of the coupling constants are significantly different (J = -156.60, -652.31, and -31.54 cm(-1) for 1, 2, and 3 respectively). Density functional theory (DFT) calculations have also been performed to gain further insight into the qualitative theoretical interpretation on the overall magnetic behavior of the complexes.

Lifetime Overproduction of Circulating Angiotensin-(1-7) Attenuates Deoxycorticosterone Acetate-Salt Hypertension-Induced Cardiac Dysfunction and Remodeling

We evaluated the development of arterial hypertension, cardiac function, and collagen deposition, as well as the level of components of the renin-angiotensin system in the heart of transgenic rats that overexpress an angiotensin (Ang)-(1-7)-producing fusion protein, TGR(A1-7)3292 (TG), which induces a lifetime increase in circulating levels of this peptide. After 30 days of the induction of the deoxycorticosterone acetate (DOCA)-salt hypertension model, DOCA-TG rats were hypertensive but presented a lower systolic arterial pressure in comparison with DOCA-Sprague-Dawley (SD) rats. In contrast to DOCA-SD rats that presented left ventricle (LV) hypertrophy and diastolic dysfunction, DOCA-TG rats did not develop cardiac hypertrophy or changes in ventricular function. In addition, DOCA-TG rats showed attenuation in mRNA expression for collagen type I and III compared with the increased levels of DOCA-SD rats. Ang II plasma and LV levels were reduced in SD and TG hypertensive rats in comparison with normotensive animals. DOCA-TG rats presented a reduction in plasma Ang-(1-7) levels; however, there was a great increase in Ang-(1-7) (approximate to 3-fold) accompanied by a decrease in mRNA expression of both angiotensin-converting enzyme and angiotensin-converting enzyme 2 in the LV. The mRNA expression of Mas and Ang II type 1 receptors in the LV was not significantly changed in DOCA-SD or DOCA-TG rats. This study showed that TG rats with increased circulating levels of Ang-(1-7) are protected against cardiac dysfunction and fibrosis and also present an attenuated increase in blood pressure after DOCA-salt hypertension. In addition, DOCA-TG rats showed an important local increase in Ang-(1-7) levels in the LV, which might have contributed to the attenuation of cardiac dysfunction and prefibrotic lesions. (Hypertension. 2010;55:889-896.)

Clinical significance of lifetime panic disorder in the course of bipolar disorder type I

Objectives: The aim of the study was to analyze the impact of lifetime panic disorder (PD) diagnosis in a sample of patients with bipolar disorder type I (BPI), evaluating clinical and demographic variables. Methods: Ninety-five outpatients from the Bipolar Disorder Research Program at the Institute of Psychiatry of the University of Sao Paulo Medical School were enrolled. Twenty-seven BPI patients with PD were compared to 68 BPI patients without any anxiety disorders regarding clinical and demographic variables. Results: Compared to BPI patients without any anxiety disorders, patients with BPI + PD presented significantly higher number of mood episodes (18.9 +/- 13.8 vs 8.5 +/- 7.8; P < .001), depressive episodes (10.8 +/- 8.2 vs 4.6 +/- 4,8; P = .001), and manic episodes (7.4 +/- 7.3 vs 3.6 +/- 3.6; P = .008). Patients with BPI + PD had more frequently a depressive episode as their first one compared to BPI patients without anxiety disorders (94.1% vs 57.5%; P = .011). Patients with BPI + PD had more comorbidity with lifetime diagnosis of drug abuse or dependence (33.3% vs 8.8%; P = .010) and eating disorders (29.6% vs 6.0%; P = .004). Conclusions: The higher number of mood episodes in general presented by patients with BPI + PD when compared with BPI patients without any anxiety disorders, along with the higher frequencies of drug misuse and eating disorders, indicates that PD comorbidity is associated with a poorer Course and outcome of BPI. The higher frequency of depression as the onset mood episode and the higher number of manic episodes in the group with PD may have important treatment implications and should be further investigated. (C) 2009 Elsevier Inc. All rights reserved.

Thiothionyl bromide (S=SBr2): The elusive isomer of dibromodisulfane (BrSSBr)

CCSD(T) with a series of correlation consistent basis up to quadruple-zeta is used to investigate the structures, vibrational spectra, relative stability, heats of formation, and barrier to isomerization of S=SBr2 and BrSSBr. It represents the most accurate and detailed characterization of these molecules to date. We show that the frequency mode at 302 cm(-1), detected in various studies and assigned to impurities by some authors, and to the anti-symmetric SBr stretch in BrSSBr by others, thus in fact corresponds to the anti-symmetric SBr stretch in the elusive S=SBr2 species; it thus corroborates and complements an earlier partial IR spectra study attributable to S=SBr2. Including corrections for relativistic and core-valence correlation effects, we also predict 26.33 (12.74) kcal/mol for Delta H-f (298.15 K) of S=SBr2 (BrSSBr). For the S=SBr2 -> BrSSBr reaction, our best estimates for the Gibbs free energy and the enthalpy of the reaction at 298.15 K are -13.71 and -13.44 kcal/mol, respectively. For a value of Delta G(#) equal to 23.52 kcal/mol, we estimate a TST rate constant, at 298.15 K, of 3.57 x 10(-5) s(-1). (c) 2007 Elsevier B.V. All rights reserved.

Dental caries of lifetime residents in Baixo Guandu, Brazil, fluoridated since 1953: a brief communication

Objectives: This study aimed to verify the dental caries prevalence in Baixo Guandu, the first Brazilian city to fluoridate its public water supplies; to compare the findings with the data from the national survey; and also to compare the prevalence in the 12-year-old age group with the data obtained before the beginning of the fluoridation. Methods: All the lifetime residents aged 5, 12, 15 to 19, and 35 to 44 years old were clinically examined (World Health Organization). Results: The means of dmft/DMFT were lower than in the Brazilian population living in fluoridated communities. The DMFT Index in 12-year-old residents decreased between 1953 and 2005 from 8.61 to 1.55. Conclusions: The addition of fluoride to public water supplies was an important ally in the improvement of the oral health of Baixo Guandu inhabitants.