Examining the relationship between specific cognitive processes and falls risk in older adults: a systematic review

This systematic review aims to establish which cognitive domains are associated with falls or falls risk. Recent evidence suggests that impaired cognition increases seniors' risk of falling. The purpose of this review was to identify the cognitive domains that are significantly associated with falls or falls risk in older adults. We conducted a systematic review of peer-reviewed journal articles published from 1948 to present, focusing on studies investigating different domains of cognitive function and their association with falls or falls risk in adults aged 60 years or older. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we completed a comprehensive search of MEDLINE, PubMed, and EMBASE databases to identify studies examining the association between cognitive function and falls or falls risk. With an expert in the field, we developed a quality assessment questionnaire to rate the quality of the studies included in this systematic review. Twenty-five studies were included in the review. We categorized studies based on two related but distinct cognitive domains: (1) executive functions or (2) dual-task ability. Twelve studies reported a significant association between executive functions and falls risk. Thirteen studies reported that dual-task performance is a predictor of falls or falls risk in older adults. Three studies did not report an association between cognition and falls risk. Consistent evidence demonstrated that executive functions and dual-task performance were highly associated with falls or falls risk. The results from this review will aid healthcare professionals and researchers in developing innovative screening and treatment strategies for mitigating falls risk by targeting specific cognitive domains.

Focussing both eyes on health outcomes: revisiting cataract surgery

Background

The appropriateness of cataract surgery procedures has been questioned, the suggestion being that the surgery is sometimes undertaken too early in the disease progression. Our three study questions were: What is the level of visual impairment in patients scheduled for cataract surgery? What is the improvement following surgery? Given the thresholds for a minimal detectable change (MDC) and a minimal clinically important difference (MCID), do gains in visual function reach the MDC and MCID thresholds?

Methods

The sample included a prospective cohort of cataract surgery patients from four Fraser Health Authority ophthalmologists. Visual function (VF-14) was assessed pre-operatively and at seven weeks post-operatively. Two groups from this cohort were included in this analysis: ‘all first eyes’ (cataract extraction on first eye) and ‘both eyes’ (cataract removed from both eyes). Descriptive statistics, change scores for VF-14 for each eye group and proportion of patients who reach the MDC and MCID are reported.

Results

One hundred and forty-two patients are included in the ‘all first eyes’ analyses and 55 in the ‘both eyes’ analyses. The mean pre-operative VF-14 score for the ‘all first eyes’ group was 86.7 (on a 0–100 scale where 100 is full visual function). The mean change in VF-14 for the 'both eyes' group was 7.5. Twenty-three percent of patients achieved improvements in visual function beyond the MCID threshold and 35% saw improvement beyond the MDC.

Conclusions

Neither threshold level for MDC or MCID for the VF-14 scale was achieved for a majority of patients. A plausible explanation for this is the very high levels of pre-operative visual functioning.

SF-6D and EQ-5D result in widely divergent incremental cost-effectiveness ratios in a clinical trial of older women: implications for health policy decisions

SUMMARY

Using two instruments (SF-6D and EQ-5D) to estimate quality adjusted life years (QALYs), we conducted an economic evaluation of a 12-month randomized controlled trial with a 12-month follow-up study in older women to evaluate the value for money of two doses of resistance training compared with balance and tone classes. We found that the incremental QALYs estimated from the SF-6D were two- to threefold greater than those estimated from the EQ-5D.

INTRODUCTION

Decision makers must continually choose between existing and new interventions. Hence, economic evaluations are increasingly prevalent. The impact of quality-adjusted life year (QALY) estimates using different instruments on the incremental cost-effectiveness ratios (ICERs) is not well understood in older adults. Thus, we compared ICERs, in older women, estimated by the EuroQol-5D (EQ-5D) and the Short Form-6D (SF-6D) to discuss implications on decision making.

METHODS

Using both the EQ-5D and the SF-6D, we compared the incremental cost per QALY gained in a randomized controlled trial of resistance training in 155 community-dwelling women aged 65 to 75 years. The 12-month randomized controlled trial included a subsequent 12-month follow-up. Our focus, the follow-up study, included 123 of the 155 participants from the Brain Power study; 98 took part in the economic evaluation (twice-weekly balance and tone exercises, n = 28; once-weekly resistance training, n = 35; twice-weekly resistance training, n = 35). Our primary outcome measure was the incremental cost per QALY gained of once- or twice-weekly resistance training compared with balance and tone exercises.

RESULTS

At cessation of the follow-up study, the incremental QALY was -0.051 (EQ-5D) and -0.144 (SF-6D) for the once-weekly resistance training group and -0.081 (EQ-5D) and -0.127 (SF-6D) for the twice-weekly resistance training group compared with balance and tone classes.

CONCLUSION

The incremental QALYs estimated from the SF-6D were two- to threefold greater than those estimated from the EQ-5D. Given the large magnitude of difference, the choice of preference-based utility instrument may substantially impact health care decisions.

Self-efficacy is independently associated with brain volume in older women

BACKGROUND

ageing is highly associated with neurodegeneration and atrophy of the brain. Evidence suggests that personality variables are risk factors for reduced brain volume. We examine whether falls-related self-efficacy is independently associated with brain volume.

METHOD

a cross-sectional analysis of whether falls-related self-efficacy is independently associated with brain volumes (total, grey and white matter). Three multivariate regression models were constructed. Covariates included in the models were age, global cognition, systolic blood pressure, functional comorbidity index and current physical activity level. MRI scans were acquired from 79 community-dwelling senior women aged 65-75 years old. Falls-related self-efficacy was assessed by the activities-specific balance confidence (ABC) scale.

RESULTS

after accounting for covariates, falls-related self-efficacy was independently associated with both total brain volume and total grey matter volume. The final model for total brain volume accounted for 17% of the variance, with the ABC score accounting for 8%. For total grey matter volume, the final model accounted for 24% of the variance, with the ABC score accounting for 10%.

CONCLUSION

we provide novel evidence that falls-related self-efficacy, a modifiable risk factor for healthy ageing, is positively associated with total brain volume and total grey matter volume.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00426881.

A comparison of the ICECAP-O with EQ-5D in a falls prevention clinical setting: are they complements or substitutes?

PURPOSE

Our research explored whether two preference-based outcome measures (EuroQol EQ-5D and ICECAP-O) are complements or substitutes in the context of the Vancouver Falls Prevention Clinic for seniors.

METHODS

The EQ-5D and ICECAP-O were administered once at 12 months post first clinic attendance. We report descriptive statistics for all baseline characteristics collected at first clinic visit and primary outcomes of interest. We ascertain feasibility by reporting item completion rates for the EQ-5D and ICECAP-O. Contingency tables for a priori assertions between the ICECAP-O and EQ-5D were used to demonstrate whether unique or similar aspects of benefit were captured. We used exploratory factor analysis, to ascertain the number of unique underlying latent factors associated with the attributes assessed by the EQ-5D and ICECAP-O.

RESULTS

We report data on 215 seniors who attended the Vancouver Falls Prevention Clinic who had a mean age of 79.3 (6.2) years. The item completion rate was 99 % for the EQ-5D and 92 % for the ICECAP-O. The two contingency tables detailed few discrepancies. The results of the exploratory factor analysis indicate that the two instruments are tapping into distinct factors that are complementary.

CONCLUSION

Our study suggests that the EQ-5D and ICECAP-O provide complementary information.

A comparison of the ICECAP-O with EQ-5D in a falls prevention clinical setting: are they complements or substitutes?

PURPOSE

Our research explored whether two preference-based outcome measures (EuroQol EQ-5D and ICECAP-O) are complements or substitutes in the context of the Vancouver Falls Prevention Clinic for seniors.

METHODS

The EQ-5D and ICECAP-O were administered once at 12 months post first clinic attendance. We report descriptive statistics for all baseline characteristics collected at first clinic visit and primary outcomes of interest. We ascertain feasibility by reporting item completion rates for the EQ-5D and ICECAP-O. Contingency tables for a priori assertions between the ICECAP-O and EQ-5D were used to demonstrate whether unique or similar aspects of benefit were captured. We used exploratory factor analysis, to ascertain the number of unique underlying latent factors associated with the attributes assessed by the EQ-5D and ICECAP-O.

RESULTS

We report data on 215 seniors who attended the Vancouver Falls Prevention Clinic who had a mean age of 79.3 (6.2) years. The item completion rate was 99 % for the EQ-5D and 92 % for the ICECAP-O. The two contingency tables detailed few discrepancies. The results of the exploratory factor analysis indicate that the two instruments are tapping into distinct factors that are complementary.

CONCLUSION

Our study suggests that the EQ-5D and ICECAP-O provide complementary information.

Guidelines for conducting and reporting economic evaluation of fall prevention strategies

Falls in older people result in substantial health burden. Compelling evidence indicates that falls can be prevented. We developed comprehensive guidelines for economic evaluations of fall prevention interventions to facilitate publication of high-quality economic evaluations of the effective strategies and aid decision making.

INTRODUCTION

The importance of economics applied to falls and fall prevention in older people has largely been overlooked. The use of different methodologies to assess the costs and health benefits of the interventions and their comparators and the inconsistent reporting in the studies limits the usefulness of these economic evaluations for decision making. We developed guidelines to encourage and facilitate completion of high-quality economic evaluations of effective fall prevention strategies.

METHODS

We used a generic checklist for economic evaluations as a platform to develop comprehensive guidelines for conducting and reporting economic evaluations of fall prevention strategies. We considered the many challenges involved, particularly in identifying, measuring, and valuing the relevant cost items.

RESULTS

We recommend researchers include cost outcomes and report incremental cost-effectiveness ratios in terms of falls prevented and quality adjusted life years in all clinical trials of fall prevention interventions. Studies should include the following cost categories: (1) implementing the intervention, (2) delivering the comparator group intervention, (3) total health care costs, (4) costs of fall-related health care resource use, and (5) personal and informal carer opportunity costs.

CONCLUSIONS

This paper provides a timely benchmark to promote comparability and consistency for conducting and reporting economic evaluations of fall prevention strategies.

Sustained economic benefits of resistance training in community-dwelling senior women

To determine whether the health and cost benefits of resistance training were sustained 12 months after formal cessation of the intervention.

DESIGN

Cost-utility analysis conducted alongside a randomized controlled trial.

SETTING

Community-dwelling women aged 65 to 75 living in Vancouver, British Columbia.

PARTICIPANTS

One hundred twenty-three of the 155 community-dwelling women aged 65 to 75 years who originally were randomly allocated to once-weekly resistance training (n=54), twice-weekly resistance training (n=52), or twice-weekly balance and tone exercises (control group; n=49) participated in the 12-month follow-up study. Of these, 98 took part in the economic evaluation (twice-weekly balance and tone exercises, n=28; once-weekly resistance training, n=35; twice-weekly resistance training, n=35).

MEASUREMENTS

The primary outcome measure was incremental cost per quality-adjusted life year (QALY) gained. Healthcare resource utilization was assessed over 21 months (2009 prices); health status was assessed using the EuroQol-5D to calculate QALYs using a 21-month time horizon.

RESULTS

Once- and twice-weekly resistance training were less costly than balance and tone classes, with incremental mean healthcare costs of Canadian dollars (CAD$)1,857 and CAD$1,077, respectively. The incremental QALYs for once- and twice-weekly resistance training were -0.051 and -0.081, respectively, compared with balance and tone exercises.

CONCLUSION

The cost benefits of participating in a 12-month resistance training intervention were sustained for the once- and twice-weekly resistance training group, whereas the health benefits were not.

Falls-related self-efficacy is independently associated with quality-adjusted life years in older women

BACKGROUND

falls-related self-efficacy is associated with falls, falls-related injury and subsequent functional decline which may lead to poor health-related quality-of-life (HRQL). To our knowledge, no previous studies have examined the independent contribution of falls-related self-efficacy to HRQL. Our primary objective was to determine whether falls-related self-efficacy is independently associated HRQL, measured by quality-adjusted life years (QALYs), in older women after accounting for known covariates.

METHOD

we conducted a secondary analysis of 135 community-dwelling older women aged 65-75 years who participated in a 12-month randomised controlled trial of resistance training. We assessed falls-related self-efficacy using the Activities-specific Balance Confidence Scale and QALYs calculated from the EuroQol EQ-5D (EQ-5D).

RESULTS

our multivariate linear regression model demonstrated that falls-related self-efficacy as assessed using the Activities-specific Balance Confidence Scale was independently associated with QALYs after accounting for age, group, education, functional co-morbidity index, general mobility, global cognition and physiological falls risk. The final model explained 52% of the variation in QALYs. The ABC Scale accounted for 5% of the total variance in the final model.

CONCLUSIONS

although falls-related self-efficacy was independently associated with QALYs after controlling for a number of known variables, there may well be other factors not investigated, such as risk taking behaviour and psychological measures, which could account for some of the association.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00426881.

Economic evaluation of dose-response resistance training in older women: a cost-effectiveness and cost-utility analysis

SUMMARY

We estimated the incremental cost-effectiveness of a once-weekly or twice-weekly resistance training intervention compared with balance and tone classes in terms of falls prevented and quality-adjusted life years (QALYs) gained. Both resistance training interventions were more likely to save health care resource money and offer better health outcomes for falls prevention than balance and tone classes.

INTRODUCTION

This study aims to estimate the incremental cost-effectiveness and cost-utility of a once-weekly or twice-weekly resistance training intervention compared with twice-weekly balance and tone classes in terms of falls prevented and QALYs gained.

METHODS

Economic evaluation was conducted concurrently with a three-arm randomized controlled trial including 155 community-dwelling women aged 65 to 75 years, Mini Mental State Examination ≥24, and visual acuity 20/40 or better. Participants received the once-weekly resistance training (n = 54), the twice-weekly resistance training (n = 51) or the twice-weekly balance and tone (the comparator) classes (n = 50) for 1 year. Measurements included the number of falls for each participant, healthcare resource utilization, and associated costs over 9 months; health status was assessed using the EQ-5D and SF-6D to calculate QALYs.

RESULTS

Based on the point estimates from our base case analysis, we found that both once- and twice-weekly resistance training groups were less costly (p < 0.05) and more effective than twice-weekly balance and tone classes. The incremental QALYs assessed using the SF-6D were 0.003 for both the once- and twice-weekly resistance training groups, compared with the twice-weekly balance and tone classes. The incremental QALYs assessed using the EQ-5D were 0.084 for the once-weekly and 0.179 for the twice-weekly resistance training groups, respectively, compared with the twice-weekly balance and tone classes.

CONCLUSIONS

An individually tailored resistance training intervention delivered once or twice weekly provided better value for money for falls prevention than balance and tone classes.

Does a home-based strength and balance programme in people aged > or =80 years provide the best value for money to prevent falls? A systematic review of economic evaluations of falls prevention interventions

OBJECTIVES

To investigate the value for money of strategies to prevent falls in older adults living in the community.

DESIGN

Systematic review of peer reviewed journal articles reporting an economic evaluation of a falls prevention intervention as part of a randomised controlled trial or a controlled trial, or using an analytical model. MEDLINE, PUBMED, EMBASE and NHS EED databases were searched to identify cost-effectiveness, cost-utility and cost-benefit studies from 1945 through July 2008.

MAIN OUTCOME MEASURES

The primary outcome measure was incremental cost-effectiveness, cost-utility and cost-benefit ratios in the reported currency and in pounds sterling at 2008 prices. The quality of the studies was assessed using two instruments: (1) an economic evaluation checklist developed by Drummond and colleagues and (2) the Quality of Health Economic Studies instrument.

RESULTS

Nine studies meeting our inclusion criteria included eight cost-effectiveness analyses, one cost-utility and one cost-benefit analysis. Three effective falls prevention strategies were cost saving in a subgroup of

PARTICIPANTS

(1) an individually customised multifactorial programme in those with four or more of the eight targeted fall risk factors, (2) the home-based Otago Exercise Programme in people > or =80 years and (3) a home safety programme in the subgroup with a previous fall. These three findings were from six studies that scored > or =75% on the Quality of Health Economic Studies instrument.

CONCLUSIONS

Best value for money came from effective single factor interventions such as the Otago Exercise Programme which was cost saving in adults 80 years and older. This programme has broad applicability thus warranting warrants health policy decision-makers' close scrutiny.

Limits on neutrino emission from gamma-ray bursts with the 40 string IceCube detector

IceCube has become the first neutrino telescope with a sensitivity below the TeV neutrino flux predicted from gamma-ray bursts if gamma-ray bursts are responsible for the observed cosmic-ray flux above 10(18)  eV. Two separate analyses using the half-complete IceCube detector, one a dedicated search for neutrinos from pγ interactions in the prompt phase of the gamma-ray burst fireball and the other a generic search for any neutrino emission from these sources over a wide range of energies and emission times, produced no evidence for neutrino emission, excluding prevailing models at 90% confidence.

Intra-unit-cell electronic nematicity of the high-T(c) copper-oxide pseudogap states

In the high-transition-temperature (high-T(c)) superconductors the pseudogap phase becomes predominant when the density of doped holes is reduced. Within this phase it has been unclear which electronic symmetries (if any) are broken, what the identity of any associated order parameter might be, and which microscopic electronic degrees of freedom are active. Here we report the determination of a quantitative order parameter representing intra-unit-cell nematicity: the breaking of rotational symmetry by the electronic structure within each CuO(2) unit cell. We analyse spectroscopic-imaging scanning tunnelling microscope images of the intra-unit-cell states in underdoped Bi(2)Sr(2)CaCu(2)O(8 +) (delta) and, using two independent evaluation techniques, find evidence for electronic nematicity of the states close to the pseudogap energy. Moreover, we demonstrate directly that these phenomena arise from electronic differences at the two oxygen sites within each unit cell. If the characteristics of the pseudogap seen here and by other techniques all have the same microscopic origin, this phase involves weak magnetic states at the O sites that break 90 degrees -rotational symmetry within every CuO(2) unit cell.

International comparison of cost of falls in older adults living in the community: a systematic review

SUMMARY

Our objective was to determine international estimates of the economic burden of falls in older people living in the community. Our systematic review emphasized the need for a consensus on methodology for cost of falls studies to enable more accurate comparisons and subgroup-specific estimates among different countries.

INTRODUCTION

The purpose of this study was to determine international estimates of the economic burden of falls in older people living in the community.

METHODS

This is a systematic review of peer-reviewed journal articles reporting estimates for the cost of falls in people aged > or =60 years living in the community. We searched for papers published between 1945 and December 2008 in MEDLINE, PUBMED, EMBASE, CINAHL, Cochrane Collaboration, and NHS EED databases that identified cost of falls in older adults. We extracted the cost of falls in the reported currency and converted them to US dollars at 2008 prices, cost items measured, perspective, time horizon, and sensitivity analysis. We assessed the quality of the studies using a selection of questions from Drummond's checklist.

RESULTS

Seventeen studies met our inclusion criteria. Studies varied with respect to viewpoint of the analysis, definition of falls, identification of important and relevant cost items, and time horizon. Only two studies reported a sensitivity analysis and only four studies identified the viewpoint of their economic analysis. In the USA, non-fatal and fatal falls cost US $23.3 billion (2008 prices) annually and US $1.6 billion in the UK.

CONCLUSIONS

The economic cost of falls is likely greater than policy makers appreciate. The mean cost of falls was dependent on the denominator used and ranged from US $3,476 per faller to US $10,749 per injurious fall and US $26,483 per fall requiring hospitalization. A consensus on methodology for cost of falls studies would enable more accurate comparisons and subgroup-specific estimates among different countries.

The independent contribution of executive functions to health related quality of life in older women

Background

Cognition is a multidimensional construct and to our knowledge, no previous studies have examined the independent contribution of specific domains of cognition to health related quality of life. To determine whether executive functions are independently associated with health related quality of life assessed using Quality Adjusted Life Years (QALYs) calculated from the EuroQol EQ-5D (EQ-5D) in older women after adjusting for known covariates, including global cognition. Therefore, we conducted a secondary analysis of community-dwelling older women aged 65-75 years who participated in a 12-month randomized controlled trial of resistance training. We assessed global cognition using the Mini-Mental State Examination (MMSE) and executive functions using the: 1) Stroop Test; 2) Trail Making Test (Part B) and 3) Digits Verbal Span Backwards Test. We calculated QALYs from the EQ-5D administered at baseline, 6 months and 12 months.

Results

Our multivariate linear regression model demonstrated the specific executive processes of set shifting and working memory, as measured by Trail Making Test (Part B) and Digits Verbal Span Backward Test (p < 0.01) respectively, were independently associated with QALYs after accounting for age, comorbidities, general mobility, and global cognition. The final model explained 50% of the variation in QALYs.

Conclusions

Our study highlights the specific executive processes of set shifting and working memory were independently associated with QALYs -- a measure of health related quality of life. Given that executive functions explain variability in QALYs, clinicians may need to consider assessing executive functions when measuring health related quality of life. Further, the EQ-5D may be used to track changes in health status over time and serve as a screening tool for clinicians.

Trial Registration

ClinicalTrials.gov Identifier: NCT00426881.

Spectroscopic fingerprint of phase-incoherent superconductivity in the cuprate pseudogap state [corrected]

A possible explanation for the existence of the cuprate "pseudogap" state is that it is a d-wave superconductor without quantum phase rigidity. Transport and thermodynamic studies provide compelling evidence that supports this proposal, but few spectroscopic explorations of it have been made. One spectroscopic signature of d-wave superconductivity is the particle-hole symmetric "octet" of dispersive Bogoliubov quasiparticle interference modulations. Here we report on this octet's evolution from low temperatures to well into the underdoped pseudogap regime. No pronounced changes occur in the octet phenomenology at the superconductor's critical temperature Tc, and it survives up to at least temperature T approximately 1.5 Tc. In this pseudogap regime, we observe the detailed phenomenology that was theoretically predicted for quasiparticle interference in a phase-incoherent d-wave superconductor. Thus, our results not only provide spectroscopic evidence to confirm and extend the transport and thermodynamics studies, but they also open the way for spectroscopic explorations of phase fluctuation rates, their effects on the Fermi arc, and the fundamental source of the phase fluctuations that suppress superconductivity in underdoped cuprates.

Glycosylation of proteinase 3 (PR3) is not required for its reactivity with antineutrophil cytoplasmic antibodies (ANCA) in Wegener's granulomatosis

OBJECTIVE

The glycosylation status of autoantigens appears to be crucial for the pathogenesis of some autoimmune diseases, since carbohydrates play a crucial role in the distinction of self from non-self. Proteinase 3 (PR3), the main target antigen for anti-neutrophil cytoplasmic antibodies (ANCA) in patients with Wegener's granulomatosis (WG), contains two Asn-linked glycosylation sites. The present study explores the influence of the glycosylation status of PR3 on the PR3 recognition by ANCA in a well characterized population of patients with WG.

METHODS

Forty-four patients with WG (459 serum samples) who participated in a multicenter randomized trial, were tested by capture ELISA for ANCA against PR3 and deglycosylated recombinant variants of PR3.

RESULTS

The patients were followed for a median of 27 months, and the median number of serum samples per patient was 10. At baseline, the correlation between the levels of ANCA against PR3 and against all the deglycosylated recombinant variants of PR3 were greater than 0.94 (?<0.001 for all the comparisons). Longitudinal analyses comparing the levels of ANCA against PR3 versus all the deglycosylated recombinant variants of PR3, using linear mixed models, showed no significant statistical differences (rho >or=0.90 in all cases).

CONCLUSION

The glycosylation status of PR3 has no impact on its recognition by ANCA in WG.

How Cooper pairs vanish approaching the Mott insulator in Bi2Sr2CaCu2O8+delta

The antiferromagnetic ground state of copper oxide Mott insulators is achieved by localizing an electron at each copper atom in real space (r-space). Removing a small fraction of these electrons (hole doping) transforms this system into a superconducting fluid of delocalized Cooper pairs in momentum space (k-space). During this transformation, two distinctive classes of electronic excitations appear. At high energies, the mysterious 'pseudogap' excitations are found, whereas, at lower energies, Bogoliubov quasi-particles-the excitations resulting from the breaking of Cooper pairs-should exist. To explore this transformation, and to identify the two excitation types, we have imaged the electronic structure of Bi(2)Sr(2)CaCu(2)O(8+delta) in r-space and k-space simultaneously. We find that although the low-energy excitations are indeed Bogoliubov quasi-particles, they occupy only a restricted region of k-space that shrinks rapidly with diminishing hole density. Concomitantly, spectral weight is transferred to higher energy r-space states that lack the characteristics of excitations from delocalized Cooper pairs. Instead, these states break translational and rotational symmetries locally at the atomic scale in an energy-independent way. We demonstrate that these unusual r-space excitations are, in fact, the pseudogap states. Thus, as the Mott insulating state is approached by decreasing the hole density, the delocalized Cooper pairs vanish from k-space, to be replaced by locally translational- and rotational-symmetry-breaking pseudogap states in r-space.