MST Method Research Articles

Clustering with Minimum Spanning Trees: How Good Can It Be?

AbstractMinimum spanning trees (MSTs) provide a convenient representation of datasets in numerous pattern recognition activities. Moreover, they are relatively fast to compute. In this paper, we quantify the extent to which they are meaningful in low-dimensional partitional data clustering tasks. By identifying the upper bounds for the agreement between the best (oracle) algorithm and the expert labels from a large battery of benchmark data, we discover that MST methods can be very competitive. Next, we review, study, extend, and generalise a few existing, state-of-the-art MST-based partitioning schemes. This leads to some new noteworthy approaches. Overall, the Genie and the information-theoretic methods often outperform the non-MST algorithms such as K-means, Gaussian mixtures, spectral clustering, Birch, density-based, and classical hierarchical agglomerative procedures. Nevertheless, we identify that there is still some room for improvement, and thus the development of novel algorithms is encouraged.

Classifying dynamic motor imagery with the locals-balanced extreme learning machine

The dynamic motor imagery (dMI) provides additional benefits as compared to the traditional motor imagery (MI) in training and neurorehabilitation field. The objective of this work is to develop a brain-computer interface (BCI) for dMI electroencephalograph (EEG). We propose a novel method by combining synchronization likelihood (SL) based functional brain network (FBN) and modified extreme learning machine (ELM) to interpret EEG. The proposed method 1) uses L1-norm and adaptive threshold instead of L2-norm and empirical threshold in SL method; 2) improves the procedure of FBN calculations (namely, SL matrix binarization) by combining threshold and MST methods; 3) detects two defects in standard ELM in fusion, and proposes the locals-balanced ELM (LBELM); 4) employs the special version of leave-one-out cross validation (LOO) approach improved the computational complexity of optimal threshold for binarization, the most effective fusion of two complementary features, and the optimal regularization parameters for regularized LBELM. As compared with the empirical threshold, the recognition rate of the optimal threshold increases by 1.39–11.11 %. Similarly, as compared with the regularized ELM, the recognition rate of LBELM increases by 2.78–9.73 %.

<i>Yersinia pestis</i> ssp. <i>pestis</i> Spatial MLVA25 Genotypic Structure in the Transboundary Saylyugem Natural Plague Focus

Advanced molecular-genetic methods for the diagnosis and typing of Yersinia pestis ssp. pestis in the field and clinical material are used for epidemiological surveillance of plague in the Saylyugem natural focus. The aim of the work was to study the spatial genotypic structure of Y. pestis ssp. pestis in the transboundary Saylyugem natural plague focus using MLVA25 typing. Materials and methods. The MLVA25 typing of 160 strains of Y. pestis ssp. Pestis isolated in the Saylyugem natural plague focus in 2012–2021 was carried out. Phylogenetic tree construction was performed with the help of UPGMA and MST methods. Results and discussion. The Y. pestis ssp. pestis strains isolated from the Saylyugem natural plague focus were differentiated into 15 MLVA types by the 25 VNTR loci cluster analysis. The studied strains form a homogeneous complex of MLVA25 types without marked geographical distribution across seven spatial groups. The analysis of the frequency of occurrence of the tandem repeats number for three variable loci of Y. pestis ssp. pestis strains shows the significant differences between the samples from the Mongolian and Russian parts of the Saylyugem natural plague focus. The most pronounced differences in spatial genotypic structure are traced through the yp4280ms62 locus.

Numerical analysis of multiple scattering theory for electronic structure calculations

Abstract Multiple scattering theory (MST) is one of the most widely used methods in electronic structure calculations. It features a perfect separation between atomic configurations and site potentials and hence provides an efficient way to simulate defected and disordered systems. This work studies MST methods from a numerical point of view and shows convergence with respect to the truncation of the angular momentum summations, which is a fundamental approximation parameter for all MST methods. We provide both rigorous analysis and numerical experiments to illustrate the efficiency of MST methods within the angular momentum representations.

Screening of Self-Assembling of Collagen IV Fragments into Stable Structures Potentially Useful in Regenerative Medicine.

The aim of the research was to check whether it is possible to use fragments of type IV collagen to obtain, as a result of self-assembling, stable spatial structures that could be used to prepare new materials useful in regenerative medicine. Collagen IV fragments were obtained by using DMT/NMM/TosO− as a coupling reagent. The ability to self-organize and form stable spatial structures was tested by the CD method and microscopic techniques. Biological studies covered: resazurin assay (cytotoxicity assessment) on BJ, BJ-5TA and C2C12 cell lines; an alkaline version of the comet assay (genotoxicity), Biolegend Legendplex human inflammation panel 1 assay (SC cell lines, assessment of the inflammation activity) and MTT test to determine the cytotoxicity of the porous materials based on collagen IV fragments. It was found that out of the pool of 37 fragments (peptides 1–33 and 2.1–2.4) reconstructing the outer sphere of collagen IV, nine fragments (peptides: 2, 4, 5, 6, 14, 15, 25, 26 and 30), as a result of self-assembling, form structures mimicking the structure of the triple helix of native collagens. The stability of spatial structures formed as a result of self-organization at temperatures of 4 °C, 20 °C, and 40 °C was found. The application of the MST method allowed us to determine the Kd of binding of selected fragments of collagen IV to ITGα1β1. The stability of the spatial structures of selected peptides made it possible to obtain porous materials based on their equimolar mixture. The formation of the porous materials was found for cross-linked structures and the material stabilized only by weak interactions. All tested peptides are non-cytotoxic against all tested cell lines. Selected peptides also showed no genotoxicity and no induction of immune system responses. Research on the use of porous materials based on fragments of type IV collagen, able to form stable spatial structures as scaffolds useful in regenerative medicine, will be continued.

"Modified Schirmer Test in Assessment of Salivary Flow Rate Among Patients on Antidepressants": A Comparative Study.

ABSTRACTAims:The objective of this study was to assess salivary flow rate (SFR) among healthy subjects or patients on antidepressant drugs such as tricyclic antidepressants (TCAs) and selective serotinin reuptake inhibitors (SSRIs) by using the “Modified Schirmer Test” (MST). To evaluate and correlate salivary flow rate by using MST and comparing it with the spitting method in patients on antidepressants and healthy control subjects.Materials and Methods:Data were collected from the patients visiting the dental college and the psychiatry department. A total of 105 subjects were included in the present study, dividing Group I as control, Group II as SSRIs, and Group III as TCAs. In all subjects, a screening questionnaire was recorded, SFR was determined by the spitting method, and MST was carried out in the morning. The MST was performed by placing a modified Schirmer tear strip (STS) on the floor of the mouth for all subjects, and readings were taken for 3 min.Results:The SFR value obtained among Group I by the spitting method was 0.83 ml at 5 min, and by the MST method was 34.97 mm at 3 min, with a P value of 0.860. The SFR value obtained among Group II by the spitting method was 0.47 ml at 5 min, and by the MST method was 26.25 mm at 3 min, with a P value of 0.001, which was highly significant. The SFR value obtained among Group III by the spitting method was 0.394 ml at 5 min, and by the MST method was 10.71 mm at 3 min, with a P value of 0.041, which was significant.Conclusions:A significant positive correlation was observed between the SFR value obtained by both the spitting method and MST. From our study, we can conclude that the MST can be used as an effective noninvasive tool to estimate SFR.

A Survey on Contactless Smart Cards and Payment System

In recent years, contactless transactions have risen rapidly. It includes NFC, MST, contactless cards, and many other payment methods. These payment methods have certain security issues, and attackers are in a regular search for the exploits to break its security. These security issues require proper analysis to secure user data from attackers. This article will discuss the contactless smart cards and payment systems in detail including the techniques used for securing user data and different possible attacks on the technology used for communication. The article also presents some countermeasures to prevent the attack and issues with those countermeasures. In addition, the article includes some future research issues and suggestions to overcome the security issues in contactless payment system.

Abstract 3656: Development of novel, selective SMARCA2 (BRM) degraders for treatment of SMARCA4 (BRG1) mutated tumors

Abstract Background: Synthetic lethality is one of the most innovative approaches for selective targeting of cancer cells with defined genetic background. SMARCA2 and SMARCA4 are two mutually exclusive helicase/ATPase catalytic subunits belonging to SWI/SNF chromatin remodeling complex. It is estimated that one in five tumors possess a mutation in proteins of this complex. The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutation in Cancer (Cosmic) shows that SMARCA4 is one of the most mutated genes in lung, colorectal, breast, melanoma and CNS tumors. Herein, we present development of a potent and selective SMARCA2 degrader, structurally unrelated to known chemotypes with first in class potential selectively targeting SMARCA4 mutant cells. Methods: ADP-Glo assay was used to identify SMARCA2 inhibitors through HTS. Binding was confirmed using MST, FTS and SPR methods. Biochemical and biophysical investigation guided rational optimization. Identified ligands were used to build a hybrid PROTAC by linking to a ligand for the E3 ligase. Western blotting was used to assess degradation efficiency and selectivity. Target engagement was confirmed using qPCR and AlphaLISA methods. On target activity was confirmed using SMARCA4 isogenic cells and a panel of SMARCA4 WT and mutant cell lines. Results: High throughput screening allowed identification of novel inhibitors of SMARCA2 ATPase activity. Medicinal chemistry efforts improved potency and affinity to the target over 100 fold. Target engagement was confirmed using biophysical methods and biomarker modulation. Proprietary ligand was used to build a hybrid PROTAC. Western blotting confirmed selective and long-lasting degradation of SMARCA2. Co-treatment with Epoxomicin confirmed proteasomal dependent degradation of targeted protein. Specific SMARCA2 depletion in SMARCA4 mutated cancer cell lines induced apoptosis, growth inhibition and cell death. Observed mechanism of action is consistent with a phenotype seen with perturbation through inhibition of ATPase activity of SMARCA2 and genetic knock-down. Conclusion: Treatment with Ryvu's PROTACs led to selective, proteasomal dependent degradation of SMARCA2 protein and in consequence to a targeted cell death of SMARCA4 mutated cancers. Fine-tuning of available compounds will allow for proof-of-concept experiments in animal models as a single agent or in combinations with radio- or immuno-therapies. Citation Format: Andrzej Mazan, Anna Wróbel, Agnieszka Dreas, Adam Radzimierski, Kinga Michalik, Anna Kowal, Katarzyna Wiklik, Katarzyna Wnuk-Lipińska, Paulina Niedziejko, Kamila Kozłowska, Magdalena Łośko, Joanna Szczęśniak, Agnieszka Sroka-Porada, Justyna Martyka, Urszula Kulesza, Karol Zuchowicz, Magdalena Zastawna, Jose Alvarez, Luigi Stasi, Peter Littlewood, Tomasz Rzymski, Krzysztof Brzózka. Development of novel, selective SMARCA2 (BRM) degraders for treatment of SMARCA4 (BRG1) mutated tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3656.

Spicing up the recipe for echoes from exotic compact objects: Orbital differences and corrections in rotating backgrounds

Recently, it has been argued that near-horizon modifications of the standard (classical) black hole spacetime could lead to observable alterations of the gravitational waveform generated by a binary black hole coalescence. Such modifications can be inspired by quantum gravity considerations, resulting in speculative horizonless exotic compact objects (ECOs) with no singularities, which may be an alternative to the classical black hole solution. A largely model-independent description of these objects proposed in the literature relies on the introduction of a partially reflective wall at some small distance away from the ``would-be'' horizon. The inspiral-merger ringdown of a pair of such objects would be subject to possibly detectable deviations from the black hole case due to matter effects. In particular, the ringdown phase would be modified by the late emergence of so-called ``echoes'' in the waveform, but most studies so far have considered spherically symmetric backgrounds. We use an in-falling scalar charge as an initial perturbation to simulate the excitation of the echoes of a rotating ECO, and we explore both the corotating and counterrotating cases, which provide distinct signals. In particular, rotation breaks the symmetry between positive and negative frequencies and introduces a subdominant frequency contribution in each echo, which we examine here for the first time. Our results follow consistently from the solution of the Teukolsky equation using the MST method developed by Mano, Suzuki, and Takasugi and the construction of the complex Green's function integrated over different particle geodesics.

Measurement of Protein-Protein Interactions through Microscale Thermophoresis (MST).

The binding interactions of PD-1 and PD-L1 have been studied by surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) over the past few years, but these investigations resulted in controversy regarding the values of the dissociation constant (Kd) ( Freeman et al., 2000 ). MST is a powerful new method for the quantitative analysis of protein-protein interactions (PPIs) with low sample consumption. The technique is based on the movement of molecules along microscopic temperature gradients, and it detects changes in their hydration shell, charge or size. One binding partner is fluorescently labeled, while the other binding partner remains label-free. We used a protocol that allows the determination of the binding affinity by MST without purification of the target protein from the cell lysate. The application of this MST method to PD-1-eGFP and PD-L1-eGFP expressed in CHO-K1 cells allowed us, for the first time, to determine the affinity of the complex formed between PD-1 and its ligand PD-L1 during tumor escape. The protocol has a variety of potential applications for studying the interactions of proteins with small molecules.

Insights into the molecular recognition of the granuphilin C2A domain with PI(4,5)P2

Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) is a key player in regulating the process of excytosis, including insulin secretion. Granuphilin, a tandem C2 domain containing protein, mediates the docking of insulin granules onto plasma membrane. The C2A domain plays key roles in this process through interaction with PI(4,5)P2. In this study, we have investigated the molecular recognition mechanism of granuphilin-C2A domain to PI(4,5)P2 head group, and further to PI(4,5)P2-nanodisc by NMR, ITC, MST and SEC methods. Our results demonstrate that PI(4,5)P2 binds to the concave surface of granuphilin-C2A domain. The key residues involved in the binding were validated by mutation analysis.

Predicting fecal sources in waters with diverse pollution loads using general and molecular host-specific indicators and applying machine learning methods

In this study we use a machine learning software (Ichnaea) to generate predictive models for water samples with different concentrations of fecal contamination (point source, moderate and low). We applied several MST methods (host-specific Bacteroides phages, mitochondrial DNA genetic markers, Bifidobacterium adolescentis and Bifidobacterium dentium markers, and bifidobacterial host-specific qPCR), and general indicators (Escherichia coli, enterococci and somatic coliphages) to evaluate the source of contamination in the samples. The results provided data to the Ichnaea software, that evaluated the performance of each method in the different scenarios and determined the source of the contamination. Almost all MST methods in this study determined correctly the origin of fecal contamination at point source and in moderate concentration samples. When the dilution of the fecal pollution increased (below 3 log10 CFU E. coli/100 ml) some of these indicators (bifidobacterial host-specific qPCR, some mitochondrial markers or B. dentium marker) were not suitable because their concentrations decreased below the detection limit. Using the data from source point samples, the software Ichnaea produced models for waters with low levels of fecal pollution. These models included some MST methods, on the basis of their best performance, that were used to determine the source of pollution in this area. Regardless the methods selected, that could vary depending on the scenario, inductive machine learning methods are a promising tool in MST studies and may represent a leap forward in solving MST cases.

Multi-laboratory evaluations of the performance of Catellicoccus marimammalium PCR assays developed to target gull fecal sources

Here we report results from a multi-laboratory (n = 11) evaluation of four different PCR methods targeting the 16S rRNA gene of Catellicoccus marimammalium originally developed to detect gull fecal contamination in coastal environments. The methods included a conventional end-point PCR method, a SYBR® Green qPCR method, and two TaqMan® qPCR methods. Different techniques for data normalization and analysis were tested. Data analysis methods had a pronounced impact on assay sensitivity and specificity calculations. Across-laboratory standardization of metrics including the lower limit of quantification (LLOQ), target detected but not quantifiable (DNQ), and target not detected (ND) significantly improved results compared to results submitted by individual laboratories prior to definition standardization. The unit of measure used for data normalization also had a pronounced effect on measured assay performance. Data normalization to DNA mass improved quantitative method performance as compared to enterococcus normalization. The MST methods tested here were originally designed for gulls but were found in this study to also detect feces from other birds, particularly feces composited from pigeons. Sequencing efforts showed that some pigeon feces from California contained sequences similar to C. marimammalium found in gull feces. These data suggest that the prevalence, geographic scope, and ecology of C. marimammalium in host birds other than gulls require further investigation. This study represents an important first step in the multi-laboratory assessment of these methods and highlights the need to broaden and standardize additional evaluations, including environmentally relevant target concentrations in ambient waters from diverse geographic regions.

On the transferability of fractional contributions to the hydration free energy of amino acids

This study reports the application of the quantum mechanical self-consistent reaction field MST method to compute the solvation profile in water of the twenty natural amino acids. The aim is to derive intrinsic fractional contributions to the hydration free energy and to examine their transferability to peptides. To this end, IEF-MST calculations have been performed at the B3LYP/6-31G(d) level for the series of acetyl amino acid amides, which were chosen as model compounds. In order to account for the flexibility of both the backbone and the side chain in deriving the hydration fractional contributions, calculations have been performed for representative conformers taken from the Dunbrack’s backbone-dependent conformational library. The results allow us to dissect the hydration free energy into backbone and side chain contributions and examine the conformational dependence of the fragmental contributions to hydration. For the backbone, different hydration contributions are found for α-helical and β-sheet conformations, which mainly reflect differences in the electrostatic contribution to hydration of the carbonyl group. In contrast, the conformational flexibility of the side chain is found to have little impact on the fractional contribution to hydration. These findings should be valuable to refine semiempirical methods for predicting solvation properties of peptides and proteins in large-scale genomic studies.

Statistical thermodynamics of 1-butanol, 2-methyl-1-propanol, and butanal

The purpose of the present investigation is to calculate partition functions and thermodynamic quantities, viz., entropy, enthalpy, heat capacity, and Gibbs free energies, for 1-butanol, 2-methyl-1-propanol, and butanal in the vapor phase. We employed the multi-structural (MS) anharmonicity method and electronic structure calculations including both explicitly correlated coupled cluster theory and density functional theory. The calculations are performed using all structures for each molecule and employing both the local harmonic approximation (MS-LH) and the inclusion of torsional anharmonicity (MS-T). The results obtained from the MS-T calculations are in excellent agreement with experimental data taken from the Thermodynamics Research Center data series and the CRC Handbook of Chemistry and Physics, where available. They are also compared with Benson's empirical group additivity values, where available; in most cases, the present results are more accurate than the group additivity values. In other cases, where experimental data (but not group additivity values) are available, we also obtain good agreement with experiment. This validates the accuracy of the electronic structure calculations when combined with the MS-T method for estimating the thermodynamic properties of systems with multiple torsions, and it increases our confidence in the predictions made with this method for molecules and temperatures where experimental or empirical data are not available.

Statistical thermodynamics of the isomerization reaction between n-heptane and isoheptane

We have employed electronic structure calculations and the recently proposed multi-structural (MS) anharmonicity method to calculate partition functions and thermodynamic quantities, in particular entropy and heat capacity, for n-heptane and isoheptane. We included all structures, of which there are 59 for n-heptane and 37 for isoheptane, and we carried out the calculations both in the local harmonic approximation and by including torsional (T) anharmonicity. In addition, ΔS°, ΔH, and ΔG° for the isomerization reaction between these two species were also calculated. It is found that all calculated thermodynamic quantities based on the MS-T approximation in the temperature range from 298 K to 1500 K agree well with experimental data from the American Petroleum Institute (API) tables or Thermodynamics Research Center (TRC) data series and with values obtained from Benson's empirical parameters fit to experiment. This demonstrates not only the high accuracy of the electronic structure calculations but also that the MS-T method can be used to include both multiple-structure anharmonicity and torsional anharmonicity in the calculation of thermodynamic properties for complex molecules that contain many torsions. It also gives us confidence that we can apply the MS-T statistical thermodynamic method to obtain thermodynamic properties (i) over a broader temperature range than that for which data are available in the API tables, TRC data series, or from empirical estimation and (ii) to the many molecules for which experimental data are not available at any temperature.

Microbiological characterization of vermicomposts by the method of multisubstrate testing

A new modification of the method of multisubstrate testing (MST, BIOLOG) is suggested. It is based on the kinetic description of bacterial growth on nutrient media during 50 h. The results of the MST represent a set of three parameters (the initial optical density, the maximum specific growth rate, and the maximum optical density) of an equation describing the growth of microbial communities on individual substrates. Methods of multivariate statistics (cluster and discriminant analyses) have been used to compare these parameters for 24 organic substrates. It is supposed that a more detailed description of the growth of microorganisms should improve the information capacity of the MST method. The effect of earthworms on vermicomposting has been studied experimentally with the MST method. An empirical rule allowing one to distinguish between vermicomposts and ordinary composts using the results of MST is suggested. Manure, earthy matter from the intestinal tracts of earthworms (Eisenia andrei), and their coprolites have been subjected to MST. A functional similarity between manure and fresh coprolites has been found. Also, three different lots of industrial vermicomposts have been compared. The cluster analysis has demonstrated a significant difference between them. The clusters depend on the nature of the initial substrates used for preparing these vermicomposts. Thus, unification of the initial substrates used for composting is necessary to obtain standardized vermicomposts.

The elastic wave propagation in two-dimensional phononic crystal at low frequencies and the anisotropy of effective velocity

The propagation of elastic waves in two-dimensional phononic crystal is investigated theoretically in the long-wavelength limit by the MST method. Exact analytical formulas for effective velocities of elastic waves are derived according to the behavior of the Mie scattering solution and the lattice sum in the long-wavelength limit. It has been found that the coupling effect between the two second-order components of the cylindrical scattered wave changes with the propagation orientation. Therefore whether the effective velocities of the propagating modes are anisotropic depends on whether the second-order components of the Mie scattering are indispensable.

16S rRNA-based assays for quantitative detection of universal, human-, cow-, and dog-specific fecal Bacteroidales: A Bayesian approach

We report the design and validation of new TaqMan ® assays for microbial source tracking based on the amplification of fecal 16S rRNA marker sequences from uncultured cells of the order Bacteroidales. The assays were developed for the detection and enumeration of non-point source input of fecal pollution to watersheds. The quantitative “universal” Bacteroidales assay BacUni-UCD detected all tested stool samples from human volunteers (18 out of 18), cat (7 out of 7), dog (8 out of 8), seagull (10/10), cow (8/8), horse (8/8), and wastewater effluent (14/14). The human assay BacHum-UCD discriminated fully between human and cow stool samples but did not detect all stool samples from human volunteers (12/18). In addition, there was 12.5% detection of dog stool (1/8), but no cross-reactivity with cat, horse, or seagull fecal samples. In contrast, all wastewater samples were positive for the BacHum-UCD marker, supporting its designation as 100% sensitive for mixed-human source identification. The cow-specific assay BacCow-UCD fully discriminated between cow and human stool samples. There was 38% detection of horse stool (3/8), but no cross-specificity with any of the other animal stool samples tested. The dog assay BacCan-UCD discriminated fully between dog and cow stool or seagull guano samples and detected 62.5% stool samples from dogs (5/8). There was some cross-reactivity with 22.2% detection of human stool (4/18), 14.3% detection of cat stool (1/7), and 28.6% detection of wastewater samples (4/14). After validation using stool samples, single-blind tests were used to further demonstrate the efficacy of the developed markers; all assays were sensitive, reproducible, and accurate in the quantification of mixed fecal sources present in aqueous samples. Finally, the new assays were compared with previously published sequences, which showed the new methodologies to be more specific and sensitive. Using Bayes’ Theorem, we calculated the conditional probability that the four assays would correctly identify general and host-specific fecal pollution in a specific watershed in California for which 73 water samples had been analyzed. Such an approach allows for a direct comparison of the efficacy of different MST methods, including those based on library-dependent methodologies. For the universal marker BacUni-UCD, the probability that fecal pollution is present when the marker is detected was 1.00; the probability that host-specific pollution is present was 0.98, 0.84, and 0.89 for the human assay HF160F, the cow assay BacCow-UCD, and the dog assay BacCan-UCD, respectively. The application of these markers should provide meaningful information to assist with efforts to identify and control sources of fecal pollution to impaired watersheds.

The Difference Ethnography Can Make: Understanding Social Mobilization and Development in the Brazilian Northeast

Ethnographic research is invaluable for social movement research. Ethnographies of everyday participation in mobilization help to counter the popular image of social movements as coherent, well-bounded entities consisting of individuals committed to the goals of the collective. In this study of the Movimento Sem Terra (the Landless Movement, or the MST) in northeastern Brazil, I establish a more complete continuum of movement membership by analyzing two interviews (one conducted in 1999, the other in 2003) with a former plantation worker named Cicero who considered himself a member of the MST in 1999 but “didn't even know what to say about the movement” three years later. Cicero's interviews are noteworthy because he is not the sort of person typically featured in studies of social mobilization: he did not join the MST because of a passionate commitment (more because the movement showed up and he couldn't see a reason not to), and he was never convinced of the MST's primary ideals or methods. Cicero's interviews provide what Lila Abu-Lughod calls a “counter-discourse,” in which people make decisions that are contradictory, and incomplete, often made without explicit articulation or even understanding. Ultimately, I argue that incorporating this broader continuum will help us better explain movement personalities and trajectories.