Dramatic Acceleration Research Articles

Italy's disappearing ‘red regions’: a longitudinal analysis

Using an analysis of time series data over an extended period, this article describes the waning strength of the left-wing vote in Italy's ‘red regions’. By analysing changes to the provincial share of the vote for successive principal left-wing parties over the period 1953–2018, the degree of continuity in relation to the left's traditional territorial entrenchment is assessed. It becomes clear that after an extended period of minimal change, in more recent years there has been an increasing disruption of previous patterns. A thorough analysis of voter transitions during the 2001–19 period in Umbria, the first red region in which the left lost control of the regional government, shows that in this case the gradual weakening of the traditional left-wing ‘vote of belonging’ has experienced a dramatic acceleration during the more recent period. This has been expressed in a growing rate of abstention, vote-switching according to the type of electoral contest, and a marked propensity to vote for populist movements and parties on both the left and right.

G1-G2 scheme: Dramatic acceleration of nonequilibrium Green functions simulations within the Hartree-Fock generalized Kadanoff-Baym ansatz

The time evolution in quantum many-body systems after external excitations is attracting high interest in many fields. The theoretical modeling of these processes is challenging, and the only rigorous quantum-dynamics approach that can treat correlated fermions in two and three dimensions is nonequilibrium Green functions (NEGF). However, NEGF simulations are computationally expensive due to their $T^3$-scaling with the simulation duration $T$. Recently, $T^2$-scaling was achieved with the generalized Kadanoff--Baym ansatz (GKBA), for the second-order Born (SOA) selfenergy, which has substantially extended the scope of NEGF simulations. In a recent Letter [Schl\"unzen \textit{et al.}, Phys. Rev. Lett. \textbf{124}, 076601 (2020)] we demonstrated that GKBA-NEGF simulations can be efficiently mapped onto coupled time-local equations for the single-particle and two-particle Green functions on the time diagonal, hence the method has been called G1--G2 scheme. This allows one to perform the same simulations with order $T^1$-scaling, both for SOA and $GW$ selfenergies giving rise to a dramatic speedup. Here we present more details on the G1--G2 scheme, including derivations of the basic equations including results for a general basis, for Hubbard systems and for jellium. Also, we demonstrate how to incorporate initial correlations into the G1--G2 scheme. Further, the derivations are extended to a broader class of selfenergies, including the $T$ matrix in the particle--particle and particle--hole channels, and the dynamically screened-ladder approximation. Finally, we demonstrate that, for all selfenergies, the CPU time scaling of the G1--G2 scheme with the basis dimension, $N_b$, can be improved compared to our first report: the overhead compared to the original GKBA, is not more than an additional factor $N_b$.

P1451MONOCYTE/NEUTROPHIL: LYMPHOCYTE RATIO, C-REACTIVE PROTEIN IN THE LAST YEAR BEFORE DEATH IN DIFFERENT VINTAGE GROUPS - RESULTS FROM THE MONDO INITIATIVE

Abstract Background and Aims Both experimental and clinical evidence have indicated the relationship between chronic inflammation and adverse outcomes in dialysis patients. It is also well know that higher white blood cell counts and their subtypes including monocyte and neutrophil counts, as well as higher neutrophil to lymphocyte ration (NLR) and monocyte to lymphocyte ration (MLR), and C-reactive protein (CRP) are related to inflammation, and higher risk of access failure, hospitalizations and death in dialysis patients. However, little has been done to explore the characteristics for each of these markers for patients with different dialysis vintage in a large sample of cohorts. Method Four time periods were identified: a) acute phase - patients who died within the 1 years on dialysis, b) early-stable phase - patients who died within the 2nd year on dialysis, c) mid-stable phase – died on the 3rd year on dialysis, and 4) late-stable phase – died on the 4th year on dialysis. All-cause mortality was recorded during the 4 studied periods. Patients with at least one monocyte count, neutrophil count, and lymphocyte count during each of the study period were included. Cubic spline functions were applied to plot the trends of neutrophil counts, monocyte counts, lymphocyte counts, MLR, NLR and CRP with month 0 being the month of the event death and counting backward until the 12 months preceding to death for the 4 studied phases. Rate of change functions were also built to study the accelerating and decelerating changes of the trends within the 12 months preceding death for each of the inflammatory markers. Results A total of 2,504 patients were included in acute phase analysis; 1,696 in the early-stable phase analysis, 1,462 patients in the mid-stable analysis, and 1,305 patients in the late-stable phase analysis (Figure 1). The rising trends in NLR and MLR started to happen around 6 months before patient death with a dramatic acceleration approximately 3 months before death. This is accompanied by a rise in CRP. There is an apparent ordered inflammatory response with dialysis vintage with trends being more marked in acute phase patients versus late-stable phase patients (Figure 2). Patients who died within the 1st year on dialysis had the highest neutrophil and monocyte counts, lower levels of lymphocyte count, and consequently higher levels of NLR and MLR in all months preceding to death. Conclusion The consistent observation of this large observational study that all the inflammatory markers show a similar trajectories in the 6 months anticipating death is remarkable. There is an apparent ordered inflammatory response by era across 4 dialysis vintage groups (acute, early-stable, mid-stable and late-stable phases) which might indicate a pathogenic role for these cell types or be an observed epiphenomena related to survivor advantage for example. This is the first detailed description of increased neutrophil and monocyte counts and notably decreased lymphocyte counts several months before death and possible mechanisms are under investigation.

Sociotype and cultural evolution: The acceleration of cultural change alongside industrial revolutions

The present work explores, from the vantage point of the sociotype, the dramatic acceleration of cultural change alongside the successive industrial revolutions, particularly in the ongoing information era. Developed within the genotype-phenotype-sociotype conceptual triad, the sociotype means the average social environment that is adaptively demanded by the “social brain” of each individual. For there is a regularity of social interaction, centered on social bonding and talking time, which has been developed as an adaptive trait, evolutionarily rooted, related to the substantial size increase of human groups. A quantitative approach to the sociotype basic traits shows fundamental competitive interrelationships taking place within an overall “attention economy.” Approaching these figures via the Planckian Distribution Equation, they can be connected with many other competitive processes taking place in the biological, economic, and cultural realms. Concerning culture, the cognitive limits of the individual, which we consider commensurate with the sociotype general limitations, impose by themselves a strict boundary on the cultural items effectively handled by each individual, fostering the overall competition and decay. Further, the emergence of differentiated generations with ample discrepancy in styles of life, social aspirations, and dominant technologies would represent a systematic bias in the competition and replacement of cultural items. Intriguingly, the cultural acceleration detected in modern societies alongside the successive industrial revolutions, with an ostensible climax in the ongoing fourth industrial revolution –the information era– might be itself a paradoxical consequence of the sociotype's dynamic constancy.

From Toppling to Sliding: Progressive Evolution of the Moosfluh Landslide, Switzerland

AbstractThis paper presents a detailed analysis of a dramatic rock slope acceleration that occurred in fall 2016 at the Moosfluh Landslide, located at the glacier tongue of the Great Aletsch Glacier (Switzerland). The acceleration that occurred in 2016 was unanticipated and exposed the valley bottom and an adjacent damned lake to high risk. This acceleration occurred in an active deep‐seated gravitational slope deformation (DSGSD) controlled primarily by deep block‐flexural toppling. In 2013, a highly accurate displacement monitoring system was developed and installed in the surroundings of the Great Aletsch Glacier, including a time‐lapse camera, GNSS, and robotic total stations. This monitoring system provided unique data during the 2016 slope acceleration which are used in this study to assess failure mechanisms, landslide volumes, and subsurface displacement geometry. Based on a novel displacement vector analysis, we find that three retrogressive secondary rockslides developed during the first six weeks of the slope acceleration, with rupture surface depths of 30 to 40 m, and estimated volumes between 1 and 4 Mm3. These rockslides display complex deformation features, including head and lateral scarps, which developed during the slope acceleration. The kinematics of these secondary rockslides changed through time, from primarily toppling to combined toppling and sliding. Our results provide a uniquely detailed understanding of the spatial and temporal evolution of deformation features and movement kinematics that occur when several sectors of a slowly moving DSGSD transitions into rapid rockslides.

Conversion of Gaseous Hydrocarbons in Cold Electron-Beam Plasma

A new method for plasma-assisted reforming of hydrocarbon gases is briefly described, and the results of oxidative (without the synthesis gas stage) and nonoxidative conversion to new gaseous and liquid products are exemplified. The method is based on the unique property of cold plasma, the dramatic acceleration of chemical processes due to the plasma activation of particles, which makes it possible to enhance reactions in small flow reactors without the use of catalysts.

Perspectives for the development of high-speed transport

Global socio-economic trends require a dramatic acceleration of transport links. The creation of new high-speed transport systems is an urgent task, the success of the solution of which largely determines the improvement of the quality of life and the trade and economic development of states, regions, cities.
 The main strategic goal of the development of the transport system is to meet the needs of society, taking into account the value of time and using innovative factors focused on the effective development of a competitive environment, offering quality transport services based on developed infrastructure, and a high level of application of innovative techniques and technologies. The Russian railways as a transport system need a good restructuring due to the fact that its qualitative characteristics, especially infrastructure, are not able to efficiently solve the existing problems of the global economy.
 The aim of this article is to study perspective trends for the development of the railway sector in the context of digitalization of the economy.

Propane activation on Zn-modified zeolite. The effect of the nature of Zn-species on the mechanism of H/D hydrogen exchange of the alkane with Brønsted acid sites

Zn-modified zeolites exhibit high activity for the aromatization of C2+ alkanes. To understand the effect of Zn-species of different nature on propane molecules activation and transformation, the H/D hydrogen exchange of zeolite Brønsted acid sites (BAS) with deuterated propane-d8 has been investigated. Two samples of the Zn-modified zeolite containing exclusively either isolated Zn2+ cations (Zn2+/H-BEA) or small (ZnO)n clusters (ZnO/H-BEA) have been studied. Zn-species of either type work jointly with BAS and may provide the synergy effect for propane CH bond activation resulting in dramatic acceleration of the H/D exchange between propane and BAS. The accelerating effect of isolated Zn2+ cations is more pronounced compared to zinc oxide clusters. Moreover, the H/D exchange occurs regioselectively into the methyl groups of propane on Zn2+/H-BEA zeolite. For ZnO/H-BEA, the methylene group becomes also involved in the exchange after some induction period. Various mechanisms providing the regioselective H/D exchange on Zn2+/H-BEA as well as the involvement of the methylene group after the induction period on ZnO/H-BEA are discussed.

PH‐Induced Fluorescence and Thermal Relaxation Rate Modulation in a Hydrazone Photoswitch

AbstractA recently developed family of bistable hydrazone‐based photochromic compounds open new possibilities for molecular machinists with their unique combination of properties. Herein we report on the effect of acid/protonation on the switching and fluorescence emission of a recently reported dimethyl amino hydrazone derivative (1). The fluorescence of 1 can be turned ON/OFF upon deprotonation/protonation cycles, and protonated 1 photoswitches efficiently. Meanwhile, acid catalysis leads to a dramatic acceleration of its thermal relaxation rate (from years to hours).

Building a data foundation: How MD Anderson and Palantir are partnering to accelerate research and improve patient care.

e18077 Background: MD Anderson (MDA) strives to maximize learning from the > 44,000 patients seen annually. This has historically been challenging due to the diverse, often unstructured, and siloed nature of patient data. To begin addressing these challenges, MDA constructed an institutional data warehouse and developed Natural Language Processing (NLP) capabilities. This allowed technical users to extract specific cohorts but proved challenging for many non-technical users. In 2018, MDA conducted a proof of concept with Palantir Technologies to integrate disparate data sources into a single cloud-based platform enabling both technical and non-technical users to directly access and analyze data. Methods: Through a highly iterative, collaborative process between clinical/research users, IT experts and Palantir engineers, 150 deidentified datasets were integrated from the existing data warehouse, NLP, molecular reports, public data and manually curated data, representing data from > 1.5 million patients. Data integration was validated and feedback from clinical users gathered. Results: In addition to centralizing data, the platform was found to: (1) Make data accessible to non-technical users by mapping data to real-world concepts, (2) Create reports backed by live data, with clear visibility into inputs, analysis and history, (3) Create templates for common analytical workflows (e.g. KM curve), and (4) Support increased collaboration through transparent, secure access controls. This resulted in dramatic acceleration of cohort identification, data extraction, and outcomes analyses. Conclusions: Integrating siloed data exposed gaps and errors arising from the unstructured nature of medical data and use of NLP. In response, we are piloting a combination of (1) Purposeful structured data capture at the time of care, (2) Use of logic to suggest commonly uncaptured but critical patient events such as progression, and (3) Auditing functionality to allow users to manually fill in gaps and correct data in a transparent manner. Expanding the data foundation unlocks the potential for more advanced research, fueling scientific discovery, while enhancing the quality and safety of patient care.

Dramatic Acceleration of Wave Condensation Mediated by Disorder in Multimode Fibers.

Classical nonlinear waves exhibit a phenomenon of condensation that results from the natural irreversible process of thermalization, in analogy with the quantum Bose-Einstein condensation. Wave condensation originates in the divergence of the thermodynamic equilibrium Rayleigh-Jeans distribution, which is responsible for the macroscopic population of the fundamental mode of the system. However, achieving complete thermalization and condensation of incoherent waves through nonlinear optical propagation is known to require prohibitive large interaction lengths. Here, we derive a discrete kinetic equation describing the nonequilibrium evolution of the random wave in the presence of a structural disorder of the medium. Our theory reveals that a weak disorder accelerates the rate of thermalization and condensation by several order of magnitudes. Such a counterintuitive dramatic acceleration of condensation can provide a natural explanation for the recently discovered phenomenon of optical beam self-cleaning. Our experiments in multimode optical fibers report the observation of the transition from an incoherent thermal distribution to wave condensation, with a condensate fraction of up to 60% in the fundamental mode of the waveguide trapping potential.

Glottic Carcinoma in Young Patients.

Recent reported evidence indicates that vocal cord carcinoma is evolving similarly to oropharyngeal cancer with an increasing number of patients without a smoking history having human papillomavirus (HPV) disease. Observations also suggest that an increasing number of patients who present with glottic carcinoma are younger than has been reported in the past. Therefore, an investigation was done to examine the incidence of glottic carcinoma in patients 30 years old (y/o) or younger. A retrospective review was done with Institutional Review Board approval to evaluate the incidence of patients 30 y/o or younger presenting with glottic carcinoma in 2 symmetric-length time periods over 28 years. These data were comprised from glottic cancer patients evaluated by the senior author (S.M.Z.) at the Massachusetts Eye and Ear Infirmary (July 1990-June 2004) and subsequently at the Massachusetts General Hospital (July 2004-June 2018). HPV testing was done on those patients identified as having a disease process at 30 y/o or younger. Between July 1990 and June 2018, 353 patients were diagnosed with glottic carcinoma. From July 1990 to June 2004, there were 112 patients, with none being 30 y/o or younger. From July 2004 to June 2018, 241 patients were diagnosed with glottic carcinoma; 11 patients (7 females, 4 males) were 30 y/o or younger. Of the 11 patients, 3 (1 female, 2 males) were 10 to 19 y/o, 3 (2 females, 1 male) were 20 to 25 y/o, and 5 (4 females, 1 male) were 26 to 30 y/o. Moreover, 10 of the 11 cases were tested and were positive for high-risk HPV. None of the 11 glottic cancer patients had been previously treated for benign recurrent respiratory papillomatosis although it was initially suspected prior to biopsy due to the morphology of the lesions and the patients' young age. Three of 11 had a history of smoking; all 3 had less than 3 pack-years. One of the 11 glottic cancer patients was treated with serial Cidofovir injections that resulted in dramatic acceleration in the growth of the cancer. Historically, glottic carcinoma is considered to be a tobacco-induced disease associated with a multidecade process of initiation, promotion, transformation, and progression. However, recent published evidence shows that glottic carcinoma can be an HPV-related disease with increasing incidence in nonsmokers. It isn't surprising that alternate malignant pathways may have a different timeline. In this investigation, an increased incidence of HPV-positive glottic cancer in patients 30 y/o or younger was documented in the past 14 years. This finding further supports the concept that glottic carcinoma is an evolving disease, and it demonstrates the increasing importance of discriminating potential glottic carcinomas in young patients from benign low-risk HPV recurrent respiratory papillomatosis.

Cognitive decline after elective and nonelective hospitalizations in older adults.

To determine whether emergent and urgent (nonelective) hospitalizations are associated with faster acceleration of cognitive decline compared to elective hospitalizations, accounting for prehospital decline. Data came from the Rush Memory and Aging Project, a prospective cohort study of community-dwelling older persons without baseline dementia. Annual measures of cognition via a battery of 19 tests were linked to 1999 to 2010 Medicare claims records. Of 777 participants, 460 (59.2%) were hospitalized over a mean of 5.0 (SD = 2.6) years; 222 (28.6%) had at least one elective and 418 (53.8%) at least one nonelective hospitalization. Mixed-effects regression models estimated change in global cognition before and after each type of hospitalization compared to no hospitalization, adjusted for age, sex, education, medical conditions, length of stay, surgery, intensive care unit, and comorbidities. Persons who were not hospitalized had a mean loss of 0.051 unit global cognition per year. In comparison, there was no significant difference in rate of decline before (0.044 unit per year) or after (0.048 unit per year) elective hospitalizations. In contrast, decline before nonelective hospitalization was faster (0.076 unit per year; estimate = -0.024, SE = 0.011, p = 0.032), and accelerated by 0.036 unit (SE = 0.005, p < 0.001) to mean loss of 0.112 unit per year after nonelective hospitalizations, more than doubling the rate in those not hospitalized. Nonelective hospitalizations are related to more dramatic acceleration in cognitive decline compared to elective hospitalizations, even after accounting for prehospital decline. These findings may inform which hospital admissions pose the greatest risk to the cognitive health of older adults.

A microdroplet-accelerated Biginelli reaction: mechanisms and separation of isomers using IMS-MS.

Electrospray ionization (ESI) combined with ion mobility spectrometry (IMS) and mass spectrometry (MS) techniques is used to examine the Biginelli reaction in an ensemble of ions generated from droplets. We find evidence for rapid dihydropyrimidinone formation from condensation of ethyl acetoacetate, benzaldehyde, and urea on the very short timescales associated with the electrospray process (∼10 μs to ∼1.0 ms). Control bulk-solution reactions show no product formation even after several days. This implies that the in-droplet reaction rate is enhanced by an astonishing factor. Examination of the reaction conditions and characterization of the intermediates en route to product shows evidence for variations in the reaction mechanism. IMS separation shows that the Knoevenagel condensation intermediate from benzaldehyde and ethyl acetoacetate exists as both the cis- and trans-isomer, in a ∼5 to 1 ratio. We suggest that the dramatic acceleration arises because of increased reagent confinement as electrosprayed droplets shrink. The ability of IMS-MS to resolve intermediates (including isomers) provides a new means of understanding reaction pathways.

Solvent in Solute System for the Synthesis of Highly Substituted Pyridine by Using Choline Hydroxide and Water

The impact of the trace quantity of water into the ionic liquid (IL) was investigated for the synthesis of highly substituted pyridine by the one pot three component condensation of aldehyde, malononitrile and thiophenol at reflux temperature. Water shown much more dramatic acceleration effect on the catalytic activity of choline hydroxide (ChOH) by diffusion of ions. This novel methodology describes the formation of the micro-heterogenous component by water depleted IL media. The present protocol offers a formation of new C-C and C-S bond, undoubtedly point out the task and recyclability of choline hydroxide.

Pressure-driven dynamics of liquid plugs in rectangular microchannels: Influence of the transition between quasi-static and dynamic film deposition regimes

In this paper, we study experimentally and theoretically the dynamics of liquid plugs in rectangular microchannels for both unidirectional and cyclic pressure forcing. In both cases, it is shown that the transition between quasi-static and dynamic film deposition behind the liquid plug leads to a dramatic acceleration of the plug, rapidly leading to its rupture. This behaviour proper to channels with sharp corners is recovered from a reduced dimension model based on previous theoretical and numerical developments. In addition, it is shown for cyclic periodic forcing that the plug undergoes stable periodic oscillations if it remains in the quasi-static film deposition regime during the first cycle, while otherwise it accelerates cyclically and ruptures. The transition between these two regimes occurs at a pressure-dependent critical initial length, whose value can be predicted theoretically.

CaO2 based Fenton-like reaction at neutral pH: Accelerated reduction of ferric species and production of superoxide radicals

One challenge in H2O2 based Fenton-like reaction is to break through the limitation of slow reduction of ferric species (FeIII). Present work describes a dramatic acceleration of Fenton-like reaction at neutral pH by using calcium peroxide (CaO2) as a source of hydrogen peroxide (H2O2) and EDTA as a chelating agent of ferric ions. In an optimized condition, phenol degradation in the H2O2 system displayed an initial latent time of 60 min, while phenol can be degraded immediately and removed completely in 30 min in the CaO2 system. Visual MINTEQ analyses indicated Fe-EDTA− was the active species in the reaction. The contribution of 1O2 in CaO2 system was excluded by the poor selectivity in phenol conversion and the comparable 1O2-TEMP EPR signals in both CaO2 and H2O2 systems. Kinetic analyses using chloroform as the probe of O2·− suggested the high production rate of O2·−, which is four orders of magnitude higher than that in H2O2 system. The mechanism of the accelerated CaO2 based Fenton-like reactions was featured by that two electrons coming from CaO2 can be utilized to promote reduction of FeIII: an inner sphere electron transfer takes place to reduce FeIII-EDTA and produce O2·−, and subsequently O2·− provides an electron to reduce another FeIII-EDTA. The revealed intrinsic reducibility in CaO2 based Fenton-like reaction represents a new strategy to break through the well-known rate limiting step of FeIII reduction in Fenton-like reaction and facilitate the removal of organic pollutants at neutral pHs, and also indicates a promising source of O2·− for diverse applications.

Secular change in dental development in New Mexican females

Recent research has indicated a dramatic acceleration of dental development in 20th century European Americans in Tennessee and Arizona, resulting in developmental stages being reached at earlier calendar ages. In order to determine whether this rate change is also observed in New Mexico, radiographs from two cohorts of European American female orthodontic patients with known ages were used to compare age by stage of development. The cohorts date to the 1970’s (n=101) and the 1990’s (n=93) and were between 5-11 years of age. Dental developmental stages were recorded for five mandibular teeth.The average calendar age difference between cohorts per tooth and developmental stage combination was less than one month, but varies among tooth/stage combinations by up to 13 months. A Pearson’s chi square test found no significant difference between the two cohorts for the 22 tooth/stage combinations. However, Cox Hazards Analysis demonstrated significant differences between the cohorts for five of the 22 tooth and stage combinations. Contrary to previous findings, the calendar age of the 1990’s cohort is older for 16 of the 22 tooth/stage combinations than the 1970’s cohort. This runs counter to the general trend of acceleration in development observed in multiple systems.

Quantifying the impact of a periodic presence of antimicrobial on resistance evolution in a homogeneous microbial population of fixed size

The evolution of antimicrobial resistance generally occurs in an environment where antimicrobial concentration is variable, which has dramatic consequences on the microorganisms’ fitness landscape, and thus on the evolution of resistance.We investigate the effect of these time-varying patterns of selection within a stochastic model. We consider a homogeneous microbial population of fixed size subjected to periodic alternations of phases of absence and presence of an antimicrobial that stops growth. Combining analytical approaches and stochastic simulations, we quantify how the time necessary for fit resistant bacteria to take over the microbial population depends on the alternation period. We demonstrate that fast alternations strongly accelerate the evolution of resistance, reaching a plateau for sufficiently small periods. Furthermore, this acceleration is stronger in larger populations. For asymmetric alternations, featuring a different duration of the phases with and without antimicrobial, we shed light on the existence of a minimum for the time taken by the population to fully evolve resistance. The corresponding dramatic acceleration of the evolution of antimicrobial resistance likely occurs in realistic situations, and may have an important impact both in clinical and experimental situations.

Molecular Identification of Cr(VI) Removal Mechanism on Vivianite Surface.

Experimental and theoretical studies were conducted to identify the molecular-scale reaction mechanism for Cr(VI) removal by a ferrous phosphate mineral, vivianite. The surface-normalized rate constant for Cr(VI) removal in a vivianite suspension at pH 7 was higher than those obtained for other Fe(II)-containing minerals (i.e., magnetite and pyrite). The highest rate constant was obtained at pH 5, which was 35- and 264-times higher than those obtained at pH 7 and 9, respectively, indicating the dramatic acceleration of removal kinetics with decreasing pH of suspension. The X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) spectroscopy revealed that Cr(VI) removal involved reduction of Cr(VI) to Cr(III) coupled with oxidation of Fe(II) to Fe(III) on the vivianite surface. In addition, the density functional theory (DFT)-optimized structure of the Cr(VI)-vivianite complex was consistent with that obtained from extended X-ray absorption fine structure (EXAFS) spectroscopy and revealed the transformation of vivianite to amorphous Fe(III) phosphate. We also demonstrated that both Cr(VI) species, HCrO4̅ and CrO42-, can effectively bind to the vivianite surface, particularly on the Fe sites having 6 neighboring Fe molecules with 4 H2O and 2 PO4 moieties. Our results show that Cr(VI) is readily reduced to Cr(III) by vivianite via adsorption and inner-sphere complexation, suggesting that in anoxic iron-phosphate-enriched environments, vivianite may significantly influence the fate and transport of Cr(VI).