Direct observation of ultrafast hydrogen bond strengthening in liquid water.

Water is one of the most important, yet least understood, liquids in nature. Many anomalous properties of liquid water originate from its well-connected hydrogen bond network1, including unusually efficient vibrational energy redistribution and relaxation2. An accurate description of the ultrafast vibrational motion of water molecules is essential for understanding the nature of hydrogen bonds and many solution-phase chemical reactions. Most existing knowledge of vibrational relaxation in water is built upon ultrafast spectroscopy experiments2-7. However, these experiments cannot directly resolve the motion of the atomic positions and require difficult translation of spectral dynamics into hydrogen bond dynamics. Here, we measure the ultrafast structural response to the excitation of the OH stretching vibration in liquid water with femtosecond temporal and atomic spatial resolution using liquid ultrafast electron scattering. We observed a transient hydrogen bond contraction of roughly 0.04 Å on a timescale of 80 femtoseconds, followed by a thermalization on a timescale of approximately 1 picosecond. Molecular dynamics simulations reveal the need to treat the distribution of the shared proton in the hydrogen bond quantum mechanically to capture the structural dynamics on femtosecond timescales. Our experiment and simulations unveil the intermolecular character of the water vibration preceding the relaxation of the OH stretch.

An intronless tau class glutathione transferase detoxifies several herbicides in flufenacet resistant ryegrass.

Resistance to pre-emergence herbicides, e.g., inhibitors of the biosynthesis of very-long-chain fatty acids (VLCFAs), is evolving in response to increased use of these compounds. Grass weeds such as ryegrasses (Lolium spp.) have accumulated resistance to various herbicide modes of action. Here, an RNA-Seq analysis was conducted using three ryegrass populations resistant to the VLCFA biosynthesis inhibitor flufenacet to investigate this phenomenon. Besides various transcripts, including putative long non-coding RNAs (lncRNAs), a single putatively functional tau class glutathione transferase (GST) was constitutively differentially expressed. It was further induced by herbicide application. This GST was expressed as a recombinant protein in Escherichia coli along with other GSTs and detoxified flufenacet rapidly in vitro. Detoxification rates of other herbicides tested in vitro were in accordance with cross-resistance patterns previously determined in vivo. A genome-wide GST analysis revealed that the candidate GST was located in a cluster of three intronless GSTs. Their intronless nature possibly results from the retroposition of cellular mRNAs followed by tandem duplication and may affect gene expression. The large number of GSTs (≥ 195) in the genome of rigid ryegrass (L. rigidum) compared to other plant organisms is likely a key factor in the ability of this weed to evolve resistance to different herbicide chemistries. However, in the case of flufenacet resistance, a single upregulated GST with high affinity for the substrate flufenacet possibly contributes over-proportionally to rapid herbicide detoxification in planta. The regulation of this gene and the role of differentially expressed transcripts, including various putative lncRNAs, require further investigation.

Monitoring the Evolution of Relative Product Populations at Early Times during a Photochemical Reaction.

Identifying multiple rival reaction products and transient species formed during ultrafast photochemical reactions and determining their time-evolving relative populations are key steps toward understanding and predicting photochemical outcomes. Yet, most contemporary ultrafast studies struggle with clearly identifying and quantifying competing molecular structures/species among the emerging reaction products. Here, we show that mega-electronvolt ultrafast electron diffraction in combination with ab initio molecular dynamics calculations offer a powerful route to determining time-resolved populations of the various isomeric products formed after UV (266 nm) excitation of the five-membered heterocyclic molecule 2(5H)-thiophenone. This strategy provides experimental validation of the predicted high (∼50%) yield of an episulfide isomer containing a strained three-membered ring within ∼1 ps of photoexcitation and highlights the rapidity of interconversion between the rival highly vibrationally excited photoproducts in their ground electronic state.

Head-to-head comparison of treatment sequences in advanced pancreatic cancer-Real-world data from the prospective German TPK clinical cohort study.

There are no clear guidelines regarding the optimal treatment sequence for advanced pancreatic cancer, as head-to-head phase III randomised trials are missing. We assess real-world effectiveness of three common sequential treatment strategies by emulating a hypothetical randomised trial. This analysis included 1551 patients with advanced pancreatic cancer from the prospective, clinical cohort study Tumour Registry Pancreatic Cancer receiving FOLFIRINOX (n = 613) or gemcitabine/nab-paclitaxel (GEMNAB; n = 938) as palliative first-line treatment. We used marginal structural modelling to compare overall survival (OS) and time to deterioration (TTD) of health-related quality of life (HRQoL) between three common first- to second-line treatment sequences, adjusting for time-varying potential confounding. The sequences were: FOLFIRINOX→GEMNAB, GEMNAB→FOLFOX/OFF and GEMNAB→nanoliposomal irinotecan (NALIRI) + 5-fluorouracil. Outcome was also calculated stratified by patients' prognostic risk according to the Pancreatic Cancer Score. Median OS and TTD of HRQoL independent of risk were 10.7 [8.9, 11.9] and 6.4 [4.8, 7.7] months for FOLFIRINOX→GEMNAB, 8.4 [7.4, 9.7] and 5.8 [4.6, 7.1] months for GEMNAB→FOLFOX/OFF and 8.9 [7.8, 10.4] and 4.6 [4.1, 6.1] months for GEMNAB→NALIRI+5-fluorouracil. Compared to FOLFIRINOX→GEMNAB, OS and TTD were worse for poor-risk patients with GEMNAB→FOLFOX/OFF (OS: HR 2.09 [1.47, 2.98]; TTD: HR 1.97 [1.19, 3.27]) and those with GEMNAB→NALIRI+5-fluorouracil (OS: HR 1.35, [0.76, 2.39]; TTD: HR 2.62 [1.56, 4.42]). Brackets denote 95%-confidence intervals. The estimated real-world effectiveness of the three treatment sequences evaluated were largely comparable. Poor-risk patients might benefit from intensified treatment with FOLFIRINOX→GEMNAB in terms of clinical and patient-reported outcomes. Future randomised trials on sequential treatments in advanced pancreatic cancer are warranted.

The Ring-Closing Reaction of Cyclopentadiene Probed with Ultrafast X-ray Scattering.

The dynamics of cyclopentadiene (CP) following optical excitation at 243 nm was investigated by time-resolved pump-probe X-ray scattering using 16.2 keV X-rays at the Linac Coherent Light Source (LCLS). We present the first ultrafast structural evidence that the reaction leads directly to the formation of bicyclo[2.1.0]pentene (BP), a strained molecule with three- and four-membered rings. The bicyclic compound decays via a thermal backreaction to the vibrationally hot CP with a time constant of 21 ± 3 ps. A minor channel leads to ring-opened structures on a subpicosecond time scale.

Micro-computed tomographic analysis of the morphology of maxillary lateral incisors.

OBJECTIVE: This study aimed to investigate the morphology of maxillary lateral incisors (MxLI) using micro-computed tomography (micro-CT). MATERIALS AND METHODS: The root canal configurations (RCC) of maxillary lateral incisors (MxLI) of a mixed Swiss-German population were examined using micro-CT, 3D imaging, and a 4-digit system code indicating the main root canal from coronal to apical thirds and the main foramina number. RESULTS: The most frequently observed RCC of MxLI were 1-1-1/1 (Vertucci I/Ve I, 80.0%), 1-1-2/2 (Ve V, 7.3%), 1-2-1/1 (Ve III, 6.4%), 2-1-1/1 (Ve II, 1.8%), and 1-1-1/2 (1.8%)(n = 110). Three additional RCC were observed less frequently (0.9%). The MxLI showed one physiological foramen in 89.1%, two in 9.1%, and seldom three (1.8%). Most accessory canals were identified in the apical third of a root (20.0%), and no accessory canals in 72.7% of the samples. CONCLUSIONS: Detailed information on the internal morphology of MxLI of a Swiss-German population is given. The most frequently observed RCC of MxLI is 1-1-1/1 (Ve I). However, accessory canals may occur in all apical thirds, and 20% of all teeth investigated showed a challenging RCC for clinical treatment. CLINICAL RELEVANCE: This study offers clinicians comprehensive data on MxLI morphology, emphasizing the significance of understanding varied RCC and accessory canal presence for improving root canal treatment outcomes. Over 25% of teeth exhibited complex RCC or accessory canals, influencing decisions during root canal treatment.

Caries status in 12-year-old children, geographical location and socioeconomic conditions across European countries: A systematic review and meta-analysis.

BACKGROUND: Understanding of socioeconomic context might enable more efficient evidence-based preventive strategies in oral health. AIM: The study assessed the caries-related socioeconomic macro-factors in 12-year-olds across European countries. DESIGN: This systematic review involved epidemiological surveys on the caries status of 12-year-olds from 2011 to 2022. DMFT was analyzed in relation to gross national income (GNI), United Nations Statistical Division geographical categorization of European countries (M49), unemployment rate, Human Development Index (HDI), and per capita expenditure on dental health care. A meta-analysis was performed for countries reporting data on DMFT, stratified by GNI, and geographical location of European countries, using a random-effects model. RESULTS: The study involved 493 360 children from 36 countries in the geographic region of Europe. The analysis confirmed a strong negative correlation between income and caries experience (p < .01). Children living in higher-income countries showed 90% lower odds of poor oral health than in middle-income countries. Children living in West Europe showed 90% lower odds of poor oral health than children living in East Europe. CONCLUSION: The strong effect of macro-level socioeconomic contexts on children's oral health suggests favoring upstream preventive oral health strategies in countries with economic growth difficulties, Eastern and Southern parts of Europe.

Distinct transcriptional responses to fludioxonil in Aspergillus fumigatus and its ΔtcsC and Δskn7 mutants reveal a crucial role for Skn7 in the cell wall reorganizations triggered by this antifungal.

BACKGROUND: Aspergillus fumigatus is a major fungal pathogen that causes severe problems due to its increasing resistance to many therapeutic agents. Fludioxonil is a compound that triggers a lethal activation of the fungal-specific High Osmolarity Glycerol pathway. Its pronounced antifungal activity against A. fumigatus and other pathogenic molds renders this agent an attractive lead substance for the development of new therapeutics. The group III hydride histidine kinase TcsC and its downstream target Skn7 are key elements of the multistep phosphorelay that represents the initial section of the High Osmolarity Glycerol pathway. Loss of tcsC results in resistance to fludioxonil, whereas a Δskn7 mutant is partially, but not completely resistant. RESULTS: In this study, we compared the fludioxonil-induced transcriptional responses in the ΔtcsC and Δskn7 mutant and their parental A. fumigatus strain. The number of differentially expressed genes correlates well with the susceptibility level of the individual strains. The wild type and, to a lesser extend also the Δskn7 mutant, showed a multi-faceted stress response involving genes linked to ribosomal and peroxisomal function, iron homeostasis and oxidative stress. A marked difference between the sensitive wild type and the largely resistant Δskn7 mutant was evident for many cell wall-related genes and in particular those involved in the biosynthesis of chitin. Biochemical data corroborate this differential gene expression that does not occur in response to hyperosmotic stress. CONCLUSIONS: Our data reveal that fludioxonil induces a strong and TcsC-dependent stress that affects many aspects of the cellular machinery. The data also demonstrate a link between Skn7 and the cell wall reorganizations that foster the characteristic ballooning and the subsequent lysis of fludioxonil-treated cells.

FOLFIRINOX or gemcitabine/nab-paclitaxel in advanced pancreatic adenocarcinoma: A novel validated prognostic score to facilitate treatment decision-making in real-world.

There is no prospective, randomised head-to-head trial comparing first-line FOLFIRINOX and gemcitabine/nab-paclitaxel in advanced pancreatic cancer. We assess real-world effectiveness and quality of life (QoL) of both regimens using a new prognostic score. This analysis includes 1540 patients with advanced pancreatic cancer from the prospective, clinical cohort study Tumour Registry Pancreatic Cancer separated into learning (n = 1027) and validation sample (n = 513). The Pancreatic Cancer Score (PCS) was developed using multivariate Cox regression. We compared overall survival (OS) and time to deterioration (TTD) for longitudinal QoL between first-line FOLFIRINOX (n = 407) and gemcitabine/nab-paclitaxel (n = 655) according to patients' prognostic risk, after inverse probability of treatment weighting (IPTW) by propensity score analysis. The PCS includes nine independent prognostic factors for survival: female sex, BMI ≥24/unknown, ECOG performance status ≥1, Charlson comorbidity index ≥1, tumour staging IV/unknown at primary diagnosis, liver metastases, bilirubin >1.5× upper limit of normal (ULN), leukocytes >ULN and neutrophil-to-lymphocyte ratio ≥4. Median OS of the validation sample was 11.4 (95% confidence interval [CI]: 10.4-14.4), 8.5 (95% CI: 6.8-9.6) and 5.9 months (95% CI: 4.0-7.4) for favourable- (0-3 risk factors), intermediate- (4-5 factors) and poor-risk group (6-9 factors), respectively. After IPTW, only poor-risk patients had significantly longer median OS and TTD of overall QoL with FOLFIRINOX (OS: 6.9 months, 95% CI: 3.9-13.3; TTD: 10.6 months, 95% CI: 2.0-14.1) vs gemcitabine/nab-paclitaxel (OS: 4.0 months, 95% CI: 2.8-4.8; TTD: 4.1 months, 95% CI: 2.4-4.5). Our novel PCS may facilitate treatment decisions in clinical routine of advanced pancreatic cancer, since only poor-risk, but not favourable-risk patients, seem to benefit from intensified treatment with FOLFIRINOX.

Compact single-shot soft X-ray photon spectrometer for free-electron laser diagnostics.

The photon spectrum from free-electron laser (FEL) light sources offers valuable information in time-resolved experiments and machine optimization in the spectral and temporal domains. We have developed a compact single-shot photon spectrometer to diagnose soft X-ray spectra. The spectrometer consists of an array of off-axis Fresnel zone plates (FZP) that act as transmission-imaging gratings, a Ce:YAG scintillator, and a microscope objective to image the scintillation target onto a two-dimensional imaging detector. This spectrometer operates in segmented energy ranges which covers tens of electronvolts for each absorption edge associated with several atomic constituents: carbon, nitrogen, oxygen, and neon. The spectrometer's performance is demonstrated at a repetition rate of 120 Hz, but our detection scheme can be easily extended to 200 kHz spectral collection by employing a fast complementary metal oxide semiconductor (CMOS) line-scan camera to detect the light from the scintillator. This compact photon spectrometer provides an opportunity for monitoring the spectrum downstream of an endstation in a limited space environment with sub-electronvolt energy resolution.

Femtosecond Electronic and Hydrogen Structural Dynamics in Ammonia Imaged with Ultrafast Electron Diffraction.

Directly imaging structural dynamics involving hydrogen atoms by ultrafast diffraction methods is complicated by their low scattering cross sections. Here we demonstrate that megaelectronvolt ultrafast electron diffraction is sufficiently sensitive to follow hydrogen dynamics in isolated molecules. In a study of the photodissociation of gas phase ammonia, we simultaneously observe signatures of the nuclear and corresponding electronic structure changes resulting from the dissociation dynamics in the time-dependent diffraction. Both assignments are confirmed by ab initio simulations of the photochemical dynamics and the resulting diffraction observable. While the temporal resolution of the experiment is insufficient to resolve the dissociation in time, our results represent an important step towards the observation of proton dynamics in real space and time.

Ultrafast Imaging of Molecules with Electron Diffraction.

Photoexcited molecules convert light into chemical and mechanical energy through changes in electronic and nuclear structure that take place on femtosecond timescales. Gas phase ultrafast electron diffraction (GUED) is an ideal tool to probe the nuclear geometry evolution of the molecules and complements spectroscopic methods that are mostly sensitive to the electronic state. GUED is a weak and passive probing tool that does not alter the molecular properties during the probing process and is sensitive to the spatial distribution of charge in the molecule, including both electrons and nuclei. Improvements in temporal resolution have enabled GUED to capture coherent nuclear motions in molecules in the excited and ground electronic states with femtosecond and subangstrom resolution. Here we present the basic theory of GUED and explain what information is encoded in the diffraction signal, review how GUED has been used to observe coherent structural dynamics in recent experiments, and discuss the advantages and limitations of the method.

Novel electronic nematicity in heavily hole-doped iron pnictide superconductors.

Electronic nematicity, a correlated state that spontaneously breaks rotational symmetry, is observed in several layered quantum materials. In contrast to their liquid-crystal counterparts, the nematic director cannot usually point in an arbitrary direction (XY nematics), but is locked by the crystal to discrete directions (Ising nematics), resulting in strongly anisotropic fluctuations above the transition. Here, we report on the observation of nearly isotropic XY-nematic fluctuations, via elastoresistance measurements, in hole-doped Ba1-x Rb x Fe2As2 iron-based superconductors. While for [Formula: see text], the nematic director points along the in-plane diagonals of the tetragonal lattice, for [Formula: see text], it points along the horizontal and vertical axes. Remarkably, for intermediate doping, the susceptibilities of these two symmetry-irreducible nematic channels display comparable Curie-Weiss behavior, thus revealing a nearly XY-nematic state. This opens a route to assess this elusive electronic quantum liquid-crystalline state.

Cost-Effectiveness of Treatment Decisions for Early Childhood Caries in Infants and Toddlers: A Systematic Review.

Background and Objectives: Early childhood caries (ECC) is a multifactorial, biofilm-mediated, sugar-related, dynamic disease of primary dental hard tissues occurring in varying degrees of severity in infants and toddlers. Untreated ECC may lead to pain, infections, and severe systemic complications. The aim of this study was to systematically review and evaluate the scientific evidence on the cost-effectiveness of treatment decisions in ECC in infants and toddlers. Materials and Methods: Observational epidemiological studies, i.e., cohort studies, case-control studies, and randomized controlled trials, reporting cost-effectiveness of treatment decisions in ECC in infants and toddlers were included in the systematic review following the PRISMA guidelines. Using an ad hoc search with search terms or keywords (MeSH), electronic databases Embase, MEDLINE via PubMed, Scopus, and gray literature were searched. Results: The search identified 494 articles, of which 446 remained after removing duplicates. A total of 417 articles were excluded after title and abstract evaluation; 29 full-text articles were screened for eligibility, and five articles were discarded. Twenty-four full-text articles were included in the systematic review, assigning 17 to prevention and seven to restoration. Results were heterogeneous; comparability of included studies is difficult because of the different methodologies used. Conflicting efficacies were demonstrated for different interventions implemented, and cost-effectiveness data were documented. Conclusions: Socioeconomic, cultural, and ethnic differences must be considered when comparing conditions in terms of cost-effectiveness. A paradigm shift from surgical towards preventive treatment decisions can be observed. Cost-effectiveness studies on therapies for ECC in infants and toddlers are needed to identify the best practice approach and the most cost-effective therapy decisions.

Oral Health Survey in Burundi; Evaluation of the Caries Experience in Schoolchildren Using the DMFT Index.

Background and objectives: There are no data on oral health in the population of Burundi. This study aimed to describe the oral health status of schoolchildren in Burundi using the dmft/DMFT index for the first time. Materials and methods: The study was designed as a cross-sectional population-based epidemiological survey. The survey was designed according to the WHO methodology for oral health surveys. Oral examinations were conducted in school rooms using a dental mirror, probe, and headlight. The following characteristics of primary dentition status were recorded: decayed (d/D), missing (m/M), and filled (f/F) teeth, and the dmft/DMFT (d + m + f t/D + M + F T) index was calculated for each subject. Quantitative and qualitative variables were represented by measures of position and variability. One-way ANOVA was used to assess differences between parametric variables. Logistic regression was performed for total caries experience and gender, age groups, living area, and geographical provinces. Results: A total of 1902 children were examined, 1007 (52.94%) six-year-olds and 895 (47.06%) in the older group. The dmft/DMFT and subgroups were statistically significantly different in terms of age groups, living areas, and geographical regions (dmft/DMFT d-subgroup and D-subgroup p < 0.01), but only for DMFT for sex. The ORs estimated by logistic regression by total caries experience showed a protective effect for 12 year old subjects and those living in southern provinces, an OR of 0.52 (95%CI 0.43-0.64) and an OR of 0.26 (95%CI 0.21-0.32), respectively. Conclusions: Dental caries in African countries, including Burundi, remains a major problem affecting the general health and wellbeing of the population. Tackling untreated caries requires a multifaceted approach, including strengthening oral health infrastructure, promoting oral health education, providing affordable dental services, and encouraging healthier eating habits.

Human adults prefer to cooperate even when it is costly.

Joint actions are cooperative activities where humans coordinate their actions to achieve individual and shared goals. While the motivation to engage in joint action is clear when a goal cannot be achieved by individuals alone, we asked whether humans are motivated to act together even when acting together is not necessary and implies incurring additional costs compared to individual goal achievement. Using a utility-based empirical approach, we investigated the extent of humans' preference for joint action over individual action, when the instrumental costs of performing joint actions outweigh the benefits. The results of five experiments showed that human adults have a stable preference for joint action, even if individual action is more effective to achieve a certain goal. We propose that such preferences can be understood as ascribing additional reward value to performing actions together.

The time-resolved atomic, molecular and optical science instrument at the Linac Coherent Light Source.

The newly constructed time-resolved atomic, molecular and optical science instrument (TMO) is configured to take full advantage of both linear accelerators at SLAC National Accelerator Laboratory, the copper accelerator operating at a repetition rate of 120 Hz providing high per-pulse energy as well as the superconducting accelerator operating at a repetition rate of about 1 MHz providing high average intensity. Both accelerators power a soft X-ray free-electron laser with the new variable-gap undulator section. With this flexible light source, TMO supports many experimental techniques not previously available at LCLS and will have two X-ray beam focus spots in line. Thereby, TMO supports atomic, molecular and optical, strong-field and nonlinear science and will also host a designated new dynamic reaction microscope with a sub-micrometer X-ray focus spot. The flexible instrument design is optimized for studying ultrafast electronic and molecular phenomena and can take full advantage of the sub-femtosecond soft X-ray pulse generation program.

Self-supervised feature extraction from image time series in plant phenotyping using triplet networks.

MOTIVATION: Image-based profiling combines high-throughput screening with multiparametric feature analysis to capture the effect of perturbations on biological systems. This technology has attracted increasing interest in the field of plant phenotyping, promising to accelerate the discovery of novel herbicides. However, the extraction of meaningful features from unlabeled plant images remains a big challenge. RESULTS: We describe a novel data-driven approach to find feature representations from plant time-series images in a self-supervised manner by using time as a proxy for image similarity. In the spirit of transfer learning, we first apply an ImageNet-pretrained architecture as a base feature extractor. Then, we extend this architecture with a triplet network to refine and reduce the dimensionality of extracted features by ranking relative similarities between consecutive and non-consecutive time points. Without using any labels, we produce compact, organized representations of plant phenotypes and demonstrate their superior applicability to clustering, image retrieval and classification tasks. Besides time, our approach could be applied using other surrogate measures of phenotype similarity, thus providing a versatile method of general interest to the phenotypic profiling community. AVAILABILITY AND IMPLEMENTATION: Source code is provided in https://github.com/bayer-science-for-a-better-life/plant-triplet-net. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Multichannel photodissociation dynamics in CS2 studied by ultrafast electron diffraction.

The structural dynamics of photoexcited gas-phase carbon disulfide (CS2) molecules are investigated using ultrafast electron diffraction. The dynamics were triggered by excitation of the optically bright 1B2(1Σu+) state by an ultraviolet femtosecond laser pulse centred at 200 nm. In accordance with previous studies, rapid vibrational motion facilitates a combination of internal conversion and intersystem crossing to lower-lying electronic states. Photodissociation via these electronic manifolds results in the production of CS fragments in the electronic ground state and dissociated singlet and triplet sulphur atoms. The structural dynamics are extracted from the experiment using a trajectory-fitting filtering approach, revealing the main characteristics of the singlet and triplet dissociation pathways. Finally, the effect of the time-resolution on the experimental signal is considered and an outlook to future experiments provided.

Transient vibration and product formation of photoexcited CS2 measured by time-resolved x-ray scattering.

We have observed details of the internal motion and dissociation channels in photoexcited carbon disulfide (CS2) using time-resolved x-ray scattering (TRXS). Photoexcitation of gas-phase CS2 with a 200 nm laser pulse launches oscillatory bending and stretching motion, leading to dissociation of atomic sulfur in under a picosecond. During the first 300 fs following excitation, we observe significant changes in the vibrational frequency as well as some dissociation of the C-S bond, leading to atomic sulfur in the both 1D and 3P states. Beyond 1400 fs, the dissociation is consistent with primarily 3P atomic sulfur dissociation. This channel-resolved measurement of the dissociation time is based on our analysis of the time-windowed dissociation radial velocity distribution, which is measured using the temporal Fourier transform of the TRXS data aided by a Hough transform that extracts the slopes of linear features in an image. The relative strength of the two dissociation channels reflects both their branching ratio and differences in the spread of their dissociation times. Measuring the time-resolved dissociation radial velocity distribution aids the resolution of discrepancies between models for dissociation proposed by prior photoelectron spectroscopy work.