Memes and their themata.

When it is instantiated as a neuronal state, a meme is characterized as a phenotype in a novel neuronal sense. A thema is an instantiation of a meme as a conscious experience (a thought-meme). It is a primitive to which no location may be attributed, and it serves as a canonical representative of a class of memes. Memes in such a class may have physical or ideal (Platonic) instantiations. Pairing of this memetic phenotype characterization with the ideal thematic primitive is an example of other pairings in nature that are identified, and in particular it informs a description of the pairing of the unconscious mind and manifestations of consciousness. Interrelationship of these pairings is what illuminates aspects of each of them. These constructs support introduction of a consciousness thesis and then a notion of a dynamic self-referential grammar that generates a growing repertoire of consciousness manifestations. A method showing how a neuronal state generates a specific concept (thema) is introduced, and a sample of a class of examples is given. Pointers to experiments relevant to development of the thesis are given.

Predicting successful aging in a population-based sample of georgia centenarians.

Used a population-based sample (Georgia Centenarian Study, GCS), to determine proportions of centenarians reaching 100 years as (1) survivors (43%) of chronic diseases first experienced between 0-80 years of age, (2) delayers (36%) with chronic diseases first experienced between 80-98 years of age, or (3) escapers (17%) with chronic diseases only at 98 years of age or older. Diseases fall into two morbidity profiles of 11 chronic diseases; one including cardiovascular disease, cancer, anemia, and osteoporosis, and another including dementia. Centenarians at risk for cancer in their lifetime tended to be escapers (73%), while those at risk for cardiovascular disease tended to be survivors (24%), delayers (39%), or escapers (32%). Approximately half (43%) of the centenarians did not experience dementia. Psychiatric disorders were positively associated with dementia, but prevalence of depression, anxiety, and psychoses did not differ significantly between centenarians and an octogenarian control group. However, centenarians were higher on the Geriatric Depression Scale (GDS) than octogenarians. Consistent with our model of developmental adaptation in aging, distal life events contribute to predicting survivorship outcome in which health status as survivor, delayer, or escaper appears as adaptation variables late in life.

Development of quantum dot-mediated fluorescence thermometry for thermal therapies.

As thermal therapies are frequently employed for management of tumors in various organs, there are growing demands for reliable and accurate intraoperative monitoring techniques of the thermal lesion. However, current monitoring techniques have limited accuracy, accessibility and are not capable of monitoring the thermal lesion in real-time during the procedure. In the present study, quantum dot-mediated fluorescence thermometry was developed and its performance was characterized to demonstrate the feasibility of spatiotemporal monitoring of thermal lesions. First, the temperature dependency of two different types of CdTe/ZnS quantum dots (QDs) were characterized in a temperature range relevant to hyperthermic therapies, and a temperature-intensity relationship was established for each QD. The spatial and temporal resolutions of the system were characterized by exposing QDs to a pre-determined spatial temperature gradient, and by monitoring the spatiotemporal temperature during gold nanoshell-mediated heating. The results demonstrated that QD-mediated thermometry is capable of measuring spatiotemporally varying temperature fields relevant for hyperthermic thermal therapies. Its implication for intraoperative image-guidance of thermal therapy was also discussed.

Prevalence of cognitive impairment without dementia in the United States.

BACKGROUND: Cognitive impairment without dementia is associated with increased risk for disability, increased health care costs, and progression to dementia. There are no population-based prevalence estimates of this condition in the United States. OBJECTIVE: To estimate the prevalence of cognitive impairment without dementia in the United States and determine longitudinal cognitive and mortality outcomes. DESIGN: Longitudinal study from July 2001 to March 2005. SETTING: In-home assessment for cognitive impairment. PARTICIPANTS: Participants in ADAMS (Aging, Demographics, and Memory Study) who were age 71 years or older drawn from the nationally representative HRS (Health and Retirement Study). Of 1770 selected individuals, 856 completed initial assessment, and of 241 selected individuals, 180 completed 16- to 18-month follow-up assessment. MEASUREMENTS: Assessments, including neuropsychological testing, neurologic examination, and clinical and medical history, were used to assign a diagnosis of normal cognition, cognitive impairment without dementia, or dementia. National prevalence rates were estimated by using a population-weighted sample. RESULTS: In 2002, an estimated 5.4 million people (22.2%) in the United States age 71 years or older had cognitive impairment without dementia. Prominent subtypes included prodromal Alzheimer disease (8.2%) and cerebrovascular disease (5.7%). Among participants who completed follow-up assessments, 11.7% with cognitive impairment without dementia progressed to dementia annually, whereas those with subtypes of prodromal Alzheimer disease and stroke progressed at annual rates of 17% to 20%. The annual death rate was 8% among those with cognitive impairment without dementia and almost 15% among those with cognitive impairment due to medical conditions. LIMITATIONS: Only 56% of the nondeceased target sample completed the initial assessment. Population sampling weights were derived to adjust for at least some of the potential bias due to nonresponse and attrition. CONCLUSION: Cognitive impairment without dementia is more prevalent in the United States than dementia, and its subtypes vary in prevalence and outcomes.

Theoretical role of square wavelet analysis in stereopsis and binocular rivalry: a mathematical model and computer simulation.

To determine stereopsis, a mathematical model and computer simulation specify that square wavelet coefficients be independently estimated for the images in each eye. Then, by comparing these independently determined coefficients, the model theorizes that the visual system both identifies those parts of the two images which lie across corresponding points and identifies those parts of the two images which lie across noncorresponding or disparate points. Given the latter occurrence, the retinal disparity is evaluated as being either stereopsis or binocular rivalry. If stereopsis is indicated, the wavelet coefficients provide a reference plane by which the depth of a disparate area is located either nearer than or more distant than the reference plane. In the model also it is proposed that the determination of depth with respect to the reference plane provides a signal for vergence of the eyes. If binocular rivalry is indicated, the model's computer simulation identifies the locus of the background fringes associated with binocular rivalry. In sum, it seems theoretically tenable that stereopsis or binocular rivalry occurs as a consequence of the comparison of one eye's wavelet coefficients with those of the other eye.

Ultrastructure of Babesia WA1 (Apicomplexa: Piroplasma) during infection of erythrocytes in a hamster model.

Babesia Washington-1 (WA1) is a newly identified intraerythrocyte infectious agent of human babesiosis in the western United States. The purpose of the present study is to describe the ultrastructural changes in affected erythrocytes during the infectious process in a susceptible animal model, the golden Syrian hamster. Two, 1-mo-old female hamsters were inoculated intraperitoneally (i.p.) with 1.8 x 10(9) Babesia WA1-infected erythrocytes originally isolated from a human case and serially passaged in hamsters. Saphenous vein blood samples (20 microl) were collected at 0, 24, 36, 48, 60, 72, 84, and 96 hr postinoculation (PI). Parasitemia was determined at each time interval by quick staining of blood smears showing 0, 2.5, 5, 10, 12.5, 22.5, 70, and almost 100% parasitemic erythrocytes at the corresponding PI time interval, respectively. Animals showed weakness and dehydration 72 hr PI inoculation, and were killed by 96 hr PI. Selected blood samples from 0, 24, 48, 72, and 96 hr were fixed in cacodylate buffer, dehydrated in ethanol gradients, resin embedded, and then thin sectioned and stained with uranyl acetate and lead citrate for transmission electron microscopy or gold-coated for scanning electron microscopy (SEM). Shape and surface membrane changes in erythrocytes were demonstrated by SEM and were more evident at 72 and 96 hr PI. Infected erythrocytes underwent changes in shape 24 hr PI, from few protrusions to several perforations, some of them resembling a "swiss cheese" appearance 96 hr PI. Several erythrocytes had irregular surface membranes and Babesia WA1 organisms were seen at different stages of development within erythrocytes, from single trophozoites to several merozoites (young trophozoites), some of them dividing to form typical tetrads. In general, Babesia WAI induced severe morphological changes in the erythrocytes, and these changes were more evident in almost all infected cells 96 hr PI.

The Aging, Demographics, and Memory Study: study design and methods.

OBJECTIVE: We describe the design and methods of the Aging, Demographics, and Memory Study (ADAMS), a new national study that will provide data on the antecedents, prevalence, outcomes, and costs of dementia and "cognitive impairment, not demented" (CIND) using a unique study design based on the nationally representative Health and Retirement Study (HRS). We also illustrate potential uses of the ADAMS data and provide information to interested researchers on obtaining ADAMS and HRS data. METHODS: The ADAMS is the first population-based study of dementia in the United States to include subjects from all regions of the country, while at the same time using a single standardized diagnostic protocol in a community-based sample. A sample of 856 individuals age 70 or older who were participants in the ongoing HRS received an extensive in-home clinical and neuropsychological assessment to determine a diagnosis of normal, CIND, or dementia. Within the CIND and dementia categories, subcategories (e.g. Alzheimer's disease, vascular dementia) were assigned to denote the etiology of cognitive impairment. CONCLUSION: Linking the ADAMS dementia clinical assessment data to the wealth of available longitudinal HRS data on health, health care utilization, informal care, and economic resources and behavior, will provide a unique opportunity to study the onset of CIND and dementia in a nationally representative population-based sample, as well as the risk factors, prevalence, outcomes, and costs of CIND and dementia.

Faith factors and internal health locus of control in patients prior to open-heart surgery.

This study explored the relationships between faith factors and internal health locus of control (IHLC) beliefs. Based on a review of different relationships of perceived control, spiritual surrender and faith factors in the liberation, we assumed a multivariate association among them. Using data from two sequential interviews and the Society of Thoracic Surgeons' Adult Cardiac Database, we tested these associations in a final sample of 202 middle-aged and older patients undergoing open-heart surgery. Primary findings from two-step multiple regression analyses supported hierarchical multi-faceted hypotheses. Greater internal control was positively associated with private prayer for coping, an event-specific, 'vicarious' control strategy, but negatively related to subjective religiosity, general faith measure controlling for other confounders, especially cardiac-significant ones.

[X chromosome inactivation pattern in elderly women over 70 years of age]. / Osobennosti inaktivatsii khromosomy X u pozhilykh zhenshchin starshe 70 let.

In the present study we have analyzed X chromosome inactivation patterns in 40 women aged from 74 to 85 years (mean age 78 years). The control group was 36 women (mean age 30 years). The most common AR-assay was used to determine X-inactivation patterns (the study of methylation patterns of HpaII site in human androgen receptor gene (HUMARA) by quantative PCR). The age dependence of X-inactivation was not observed. We have detected skewed X-inactivation in three women among 40 (7.5%) elderly women comparing to two women among 36 (5.5%) women from control group. The difference was not found to be statistically significant. We made a suggestion that higher incidence of skewed X-inactivation in elderly women revealed by previous studies could occur due to some experimental ambiguities as heterogeneity of the group studied; inclusion of women having relatives with genetic abnormalities associated with skewed X-inactivation patterns; the difference of X chromosome inactivation skewing determination. We conclude that present study does not show X chromosome inactivation to be age dependent.

Visual image analysis by square wavelets: empirical evidence supporting a theoretical agreement between wavelet analysis and receptive field organization of visual cortical neurons.

It was proposed that the human visual system analyzes images into square wavelets. To test this view, comparisons were made between the perceived similarity-dissimilarity of alphabet letters and the wavelet analyses of those same letters. For the proposal to be considered tenable, the coefficients of the wavelet analysis of similar letters must be similar, and the coefficients of the wavelet analysis of dissimilar letters must be dissimilar. From a selection of 12 letters, four pairs of letters had been reported by Van der Heijden, Mathas, and Van den Roovaart as very similar, and four other pairs of letters dissimilar. Each of the 12 letters was separately depicted in 8 x 8 matrices, and the signal represented by each of the matrices was analyzed into square wavelets using a new and original procedure which yielded a single set of coefficients for each matrix. Correlations between sets of coefficients were high (r ranged from .88 to .58) for those letter pairs judged high in similarity; correlations were low (r ranged from -.02 to .29) for those letter pairs judged low in similarity. When the correlations between the coefficients of wavelets of all eight-letter pairs were compared with the judged similarity-dissimilarity of all eight-letter pairs, the linear agreement was statistically significant. Agreement was found between the neurophysiological mapping of receptive fields of visual cortical neurons and the vectors or the pattern of pluses and minuses which characterized the wavelet analysis. Furthermore, regeneration of the visual image, or the pattern of neural activity representing the image, could be described by a tree-like flow of information among visual cortical neurons which received response data from visual receptive fields, the response data being wavelet coefficients. Results indicate the analysis accurately produces reliable transformations of visual patterns and may be a process used by the visual system.

Trends in scores on tests of cognitive ability in the elderly U.S. population, 1993-2000.

OBJECTIVE: This study investigates cohort differences in cognitive functioning among Americans aged 70 or older in 1993, 1995, 1998, and 2000. METHODS: The study draws on self-respondent data from four waves of the Asset and Health Dynamics Among the Oldest Old Study and the Health and Retirement Study surveys collected between 1993 and 2000. Cognitive performance scores for each of four components (immediate recall, delayed recall, serial 7s, and mental status) and their sum are compared across cohorts, unadjusted and with adjustments for survey design features and demographic characteristics. RESULTS: Unadjusted scores suggest cohort improvements in several components of cognitive functioning between 1993 and 1998, and little change between 1998 and 2000. However, these improvements largely disappear after confounding features of the survey design (changes in age distribution of the sample across waves and prior exposure to the cognitive tests) and changes in the demographic composition of the sample (race, ethnicity, and gender) are adjusted for. DISCUSSION: There appears to have been little improvement of cognitive functioning across recent cohorts of older Americans. However, the study points out the complexities of using panel data to study cohort differences, particularly when the measures of interest are likely influenced by prior wave participation. Future studies based on other data sources are needed.

Circadian response of annual weeds to glyphosate and glufosinate.

Five field experiments were conducted in 1998 and 1999 in Minnesota to examine the influence of time of day efficacy of glyphosate [N-(phosphonomethyl)glycine] and glufosinate [2-amino-4-(hydroxymethyl-phosphinyl)butanoic acid] applications on the control of annual weeds. Each experiment was designed to be a randomized complete block with four replications using plot sizes of 3 x 9 m. Glyphosate and glufosinate were applied at rates of 0.421 kg ae/ha and 0.292 kg ai/ha, respectively, with and without an additional adjuvant that consisted of 20% nonionic surfactant and 80% ammonium sulfate. All treatments were applied with water at 94 L/ha. Times of day for the application of herbicide were 06:00h, 09:00h, 12:00h, 15:00h, 18:00h, 21:00h, and 24:00h. Efficacy was evaluated 14 d after application by visual ratings. At 14 d, a circadian response to each herbicide was found, with greatest annual weed control observed with an application occurring between 09:00h and 18:00h and significantly less weed control observed with an application at 06:00h, 21:00h, or 24:00h. The addition of an adjuvant to both herbicides increased overall efficacy, but did not overcome the rhythmic time of day effect. Results of the multiple regression analysis showed that after environmental temperature, time of day was the second most important predictor of percent weed kill. Thus, circadian timing of herbicide application significantly influenced weed control with both glyphosate and glufosinate.

GIGANTEA and SPINDLY genes linked to the clock pathway that controls circadian characteristics of transpiration in Arabidopsis.

Several "clock" genes that regulate the circadian system in Arabidopsis thaliana have been identified. The GIGANTEA (GI) gene has been shown to participate in the circadian system that is linked to overt rhythms in gene expression, leaf movements, hypocotyl elongation, and photoperiodic control of flowering in Arabidopsis. During continuous light (LL), circadian expression patterns in gi-2 mutants show reduced amplitudes and altered period lengths when compared with controls. Rhythms in stomatal function, such as transpiration, have been shown to be endogenous and persist in constant lighting conditions. In order to test for a physiologic variable that might be affected by the circadian clock via the GI gene, we compared circadian characteristics of transpiration between three Arabidopsis mutants (gi-2, spy-4, spy-4/gi-2) and wild-type (WT) controls in synchronized (LD for 2.5d) and free-running (LL for 3d) conditions. Each genotype showed a significant circadian rhythm in LD at p < 0.001, with acrophases located near the middle of the daily 14h L-span, with average amplitudes for WT: 18.9%, gi-2: 16.1%, spy-4: 7.7%, and spy-4/gi-2: 5.3%. On the first day in LL, the circadian amplitude was dramatically reduced to 3.1% for gi-2 compared with WT (11.9%), while amplitudes for spy-4 (6.9%) and spy-4/gi-2 (5.7%) were not significantly changed from LD. The amplitude for gi-2 remained low during days 2 (4.2%) and 3 (2.1%) in LL, while it slowly dampened for the WT (8.6 and 6.6%). The amplitudes for spy-4 (6.6%) and spy-4/gi-2 (5.6%) on day 2 in LL were indistinguishable from the LD span, but finally dampened on day 3 in LL (1.9 and 2.3%, respectively). These data suggest that transpiration is a physiologic variable controlled by a circadian system that involves both the GI and SPY proteins.

Vascular defense responses in rice: peroxidase accumulation in xylem parenchyma cells and xylem wall thickening.

The rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae is a vascular pathogen that elicits a defensive response through interaction with metabolically active rice cells. In leaves of 12-day-old rice seedlings, the exposed pit membrane separating the xylem lumen from the associated parenchyma cells allows contact with bacterial cells. During resistant responses, the xylem secondary walls thicken within 48 h and the pit diameter decreases, effectively reducing the area of pit membrane exposed for access by bacteria. In susceptible interactions and mock-inoculated controls, the xylem walls do not thicken within 48 h. Xylem secondary wall thickening is developmental and, in untreated 65-day-old rice plants, the size of the pit also is reduced. Activity and accumulation of a secreted cationic peroxidase, PO-C1, were previously shown to increase in xylem vessel walls and lumen. Peptide-specific antibodies and immunogold-labeling were used to demonstrate that PO-C1 is produced in the xylem parenchyma and secreted to the xylem lumen and walls. The timing of the accumulation is consistent with vessel secondary wall thickening. The PO-C1 gene is distinct but shares a high level of similarity with previously cloned pathogen-induced peroxidases in rice. PO-C1 gene expression was induced as early as 12 h during resistant interactions and peaked between 18 and 24 h after inoculation. Expression during susceptible interactions was lower than that observed in resistant interactions and was undetectable after infiltration with water, after mechanical wounding, or in mature leaves. These data are consistent with a role for vessel secondary wall thickening and peroxidase PO-C1 accumulation in the defense response in rice to X. oryzae pv. oryzae.

The cytotoxicity of chronic neuroinflammation upon basal forebrain cholinergic neurons of rats can be attenuated by glutamatergic antagonism or cyclooxygenase-2 inhibition.

The proinflammagen lipopolysaccharide (LPS) was infused chronically (37 days) into the basal forebrain of rats. The current study determined whether the chronic administration of either a non-competitive N-methyl-D-aspartate- (NMDA-) sensitive receptor antagonist, memantine, or a selective cyclooxygenase-2 (COX2)/lipoxygenase inhibitor, CI987, could provide significant neuroprotection from the cytotoxic effects of LPS-induced neuroinflammation. Chronic LPS infusions decreased cortical choline acetyltransferase activity, which paralleled a decline in the number of choline-acetyltransferase-immunoreactive-cells within the basal forebrain as well as the number of activated resident microglia. The infusions appeared to be selective for cholinergic neurons. Peripheral administration of memantine (i.p.) or CI987 (s.c.) significantly attenuated the cytotoxic effects of the chronic inflammatory processes upon cholinergic cells within the basal forebrain. However, only CI987 attenuated the neuroinflammation produced by LPS and the subsequent changes in microglial activation. These results indicate that the cytotoxic effects of chronic neuroinflammation may involve prostanoid synthesis and may operate through NMDA receptors, and that the effects of prostaglandins occur upstream to NMDA-receptor activation.

Structure-based thermodynamic analysis of the dissociation of protein phosphatase-1 catalytic subunit and microcystin-LR docked complexes.

The relationship between the structure of a free ligand in solution and the structure of its bound form in a complex is of great importance to the understanding of the energetics and mechanism of molecular recognition and complex formation. In this study, we use a structure-based thermodynamic approach to study the dissociation of the complex between the toxin microcystin-LR (MLR) and the catalytic domain of protein phosphatase-1 (PP-1c) for which the crystal structure of the complex is known. We have calculated the thermodynamic parameters (enthalpy, entropy, heat capacity, and free energy) for the dissociation of the complex from its X-ray structure and found the calculated dissociation constant (4.0 x 10(-11)) to be in excellent agreement with the reported inhibitory constant (3.9 x 10(-11)). We have also calculated the thermodynamic parameters for the dissociation of 47 PP-1c:MLR complexes generated by docking an ensemble of NMR solution structures of MLR onto the crystal structure of PP-1c. In general, we observe that the lower the root-mean-square deviation (RMSD) of the docked complex (compared to the X-ray complex) the closer its free energy of dissociation (deltaGd(o)) is to that calculated from the X-ray complex. On the other hand, we note a significant scatter between the deltaGd(o) and the RMSD of the docked complexes. We have identified a group of seven docked complexes with deltaGd(o) values very close to the one calculated from the X-ray complex but with significantly dissimilar structures. The analysis of the corresponding enthalpy and entropy of dissociation shows a compensation effect suggesting that MLR molecules with significant structural variability can bind PP-1c and that substantial conformational flexibility in the PP-1c:MLR complex may exist in solution.

Pathological and biochemical consequences of acute and chronic neuroinflammation within the basal forebrain cholinergic system of rats.

Inflammatory processes may play a critical role in the degeneration of basal forebrain cholinergic cells that underlies some of the cognitive impairments associated with Alzheimer's disease. In the present study, the proinflammagen lipopolysaccharide, from the cell wall of Gram-negative bacteria, was used to produce inflammation within the basal forebrain of rats. The effects of acute, high-dose injections of lipopolysaccharide (2, 20 or 40 microg) upon basal forebrain chemistry and neuronal integrity were compared with the effects of chronic, low-dose lipopolysaccharide infusions (0.18, 0.25, 1.8 or 5.0 microg/h) for either 14, 37, 74 or 112 days. Acute exposure to lipopolysaccharide decreased cortical choline acetyltransferase activity and the number of immunoreactive choline acetyltransferase-positive cells within a small region of the basal forebrain. Regional levels of five different neuropeptides were unchanged by acute, high-dose lipopolysaccharide injections. Chronic lipopolysaccharide infusions produced (i) a time-dependent, but not dose-dependent, decrease in cortical choline acetyltransferase activity that paralleled a decline in the number of choline acetyltransferase- and p75-immunoreactive cells within the basal forebrain, and (ii) a dense distribution of reactive astrocytes and microglia within the basal forebrain. Chronic neuroinflammation might underlie the genesis of some neuropathological changes associated with normal ageing or Alzheimer's disease.

Peripheral administration of novel anti-inflammatories can attenuate the effects of chronic inflammation within the CNS.

In the present study we investigated whether nitroflurbiprofen (NFP) or nitro-aspirin can reduce the inflammatory response induced by continuous infusion of lipopolysaccharide (LPS) into the fourth ventricular space of the rat's brain for 30 days. The chronic LPS infusion produced an extensive inflammation that was particularly evident in the hippocampus, subiculum and entorhinal and piriform cortices. Daily peripheral administration of NFP dose-dependently, and significantly, attenuated the brain inflammation as indicated by the decreased density and reactive state of microglial cells. Daily peripheral administration of nitro-aspirin also attenuated the brain inflammation, but to a much lesser degree than NFP. The results demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs) could reduce brain inflammation and that NFP is an effective anti-inflammatory agent.

CAMRA: chemical shift based computer aided protein NMR assignments.

A suite of programs called CAMRA (Computer Aided Magnetic Resonance Assignment) has been developed for computer assisted residue-specific assignments of proteins. CAMRA consists of three units: ORB, CAPTURE and PROCESS. ORB predicts NMR chemical shifts for unassigned proteins using a chemical shift database of previously assigned homologous proteins supplemented by a statistically derived chemical shift database in which the shifts are categorized according to their residue, atom and secondary structure type. CAPTURE generates a list of valid peaks from NMR spectra by filtering out noise peaks and other artifacts and then separating the derived peak list into distinct spin systems. PROCESS combines the chemical shift predictions from ORB with the spin systems identified by CAPTURE to obtain residue specific assignments. PROCESS ranks the top choices for an assignment along with scores and confidence values. In contrast to other auto-assignment programs, CAMRA does not use any connectivity information but instead is based solely on matching predicted shifts with observed spin systems. As such, CAMRA represents a new and unique approach for the assignment of protein NMR spectra. CAMRA will be particularly useful in conjunction with other assignment methods and under special circumstances, such as the assignment of flexible regions in proteins where sufficient NOE information is generally not available. CAMRA was tested on two medium-sized proteins belonging to the chemokine family. It was found to be effective in predicting the assignment providing a database of previously assigned proteins with at least 30% sequence identity is available. CAMRA is versatile and can be used to include and evaluate heteronuclear and three-dimensional experiments.