Delays in Leniency Application: Is There Really a Race to the Enforcer's Door?

This paper studies cartels’ strategic behavior in delaying leniency applications, a take-up decision that has been ignored in the previous literature. Using European Commission decisions issued over a 16-year span, we show, contrary to common beliefs and the existing literature, that conspirators often apply for leniency long after a cartel collapses. We estimate hazard and probit models to study the determinants of leniency-application delays. Statistical tests find that delays are symmetrically affected by antitrust policies and macroeconomic fluctuations. Our results shed light on the design of enforcement programs against cartels and other forms of conspiracy

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells

Pilot evaluation of a walking school bus program in a low-income, urban community

<p>Abstract</p> <p>Background</p> <p>To evaluate the impact of a walking school bus (WSB) program on student transport in a low-income, urban neighborhood.</p> <p>Methods</p> <p>The design was a controlled, quasi-experimental trial with consecutive cross-sectional assessments. The setting was three urban, socioeconomically disadvantaged, public elementary schools (1 intervention vs. 2 controls) in Seattle, Washington, USA. Participants were ethnically diverse students in kindergarten-5^thgrade (aged 5–11 years). The intervention was a WSB program consisting of a part-time WSB coordinator and parent volunteers. Students' method of transportation to school was assessed by a classroom survey at baseline and one-year follow-up. The Pearson Chi-squared test compared students transported to school at the intervention versus control schools at each time point. Due to multiple testing, we calculated adjusted p-values using the Ryan-Holm stepdown Bonferroni procedure. McNemar's test was used to examine the change from baseline to 12-month follow-up for walking versus all other forms of school transport at the intervention or control schools.</p> <p>Results</p> <p>At baseline, the proportions of students (n = 653) walking to the intervention (20% +/- 2%) or control schools (15% +/- 2%) did not differ (<it>p </it>= 0.39). At 12-month follow up, higher proportions of students (n = 643, <it>p </it>= 0.001)) walked to the intervention (25% +/- 2%) versus the control schools (7% +/- 1%). No significant changes were noted in the proportion of students riding in a car or taking the school bus at baseline or 12-month follow up (all <it>p </it>> 0.05). Comparing baseline to 12-month follow up, the numbers of students who walked to the intervention school increased while the numbers of students who used the other forms of transport did not change (<it>p </it>< 0.0001). In contrast, the numbers of students who walked to the control schools decreased while the numbers of students who used the other forms of transport did not change (<it>p </it>< 0.0001).</p> <p>Conclusion</p> <p>A WSB program is a promising intervention among urban, low-income elementary school students that may promote favorable changes toward active transport to school.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT00402701</p

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Effects of cannabis ingestion on endometriosis-associated pelvic pain and related symptoms

Background: The use of cannabis for symptoms of endometriosis was investigated utilising retrospective archival data from Strainprint Technologies Ltd., a Canadian data technology company with a mobile phone application that tracks a range of data including dose, mode of administration, chemovar and their effects on various self-reported outcomes, including pelvic pain. Methods: A retrospective, electronic record-based cohort study of StrainprintTM users with selfreported endometriosis was conducted. Self-rated cannabis efficacy, defined as a function of initial and final symptom ratings, was investigated across the included symptom clusters of cramps, pelvic pain, gastrointestinal pain, nausea, depression, and low libido. Cannabis dosage form, dose and cannabinoid ratio information was also recorded. Results: A total number of 252 participants identifying as suffering endometriosis recorded 16193 sessions using cannabis between April 2017 and February 2020. The most common method of ingestion was inhalation (n = 10914, 67.4%), with pain as the most common reported symptom being treated by cannabis (n = 9281, 57.3%). Gastrointestinal symptoms, though a less common reason for cannabis usage (15.2%), had the greatest self-reported improvement after use. Inhaled forms had higher efficacy for pain, while oral forms were superior for mood and gastrointestinal symptoms. Dosage varied across ingestion methods, with a median dose of 9 inhalations (IQR 5 to 11) for inhaled dosage forms and 1 mg/mL (IQR 0.5 to 2) for other ingested dosage forms. The ratio of THC to CBD had a statistically significant, yet clinically small, differential effect on efficacy, depending on method of ingestion. Conclusions: Cannabis appears to be effective for pelvic pain, gastrointestinal issues and mood, with effectiveness differing based on method of ingestion. The greater propensity for use of an inhaled dosage delivery may be due to the rapid onset of pain-relieving effects versus the slower onset of oral products. Oral forms appeared to be superior compared to inhaled forms in the less commonly reported mood or gastrointestinal categories. Clinical trials investigating the tolerability and effectiveness of cannabis for endometriosis pain and associated symptoms are urgently required

UV-FTMW DOUBLE RESONANCE SPECTROSCOPY AND CONFORMATIONAL STRUCTURAL DETERMINATION OF BIOLOGICALLY RELEVANT MOLECULES

Author Institution: Department of Chemistry, University of Virginia, McCormick Rd., P.O. Box 400319, Charlottesville, VA 22904Our Chirped-Pulse FTMW spectrometer has been used to obtain the pure rotational spectrum of various biomolecules with high signal-to-noise. The spectrometer operates from 7.5 to 18.5 GHz and records spectra with 80 kHz resolution for each individual valve pulse, where signal averaging is used to reach the desired signal-to-noise level. This allows for rapid acquisition of the pure rotational spectrum. We also demonstrate the ability to obtain conformer selective electronic spectra using UV-FTMW double resonance spectroscopy following the work of Endo.} \textbf{73} (2002), 165.} For biomolecules where many conformers are populated in the supersonic expansion, assigning UV bands to the correct conformer can be difficult. Upon assignment of the pure rotational spectrum, the rotational transition from a specific conformer can be monitored as a function of the laser frequency. When resonant, the laser modulates the amplitude of the pure rotational transition indicating UV absorbance and providing instant conformer assignment with rotational resolution. UV excitation is performed using a YAG pumped dye laser with 0.025 cm$^{-1}$ bandwidth. Results will be presented for para-methoxyphenethylamine, a neurotransmitter, which has seven conformers populated in the supersonic expansion.} \textbf{4} (2002), 5244.

ISOMERIZATION DYNAMICS OF CYCLOPROPANECARBOXALDEHYDE USING IR-CHIRPED-PULSE FTMW DOUBLE RESONANCE SPECTROSCOPY

Author Institution: Department of Chemistry, University of Virginia, McCormick Rd., P.O. Box 400319, Charlottesville, VA 22904IR-chirped-pulse FTMW Double resonance spectroscopy is used to examine the vibrationally excited isomerization dynamics of cyclopropanecarboxaldehyde (CPCA). CPCA has two conformers, \textit{cis} and \textit{trans}, which are both populated in the supersonic expansion. The barrier to \textit{cis}$\longrightarrow$\textit{trans} interconversion was found to be 1540$\pm$144 cm$^{-1}$, where the \textit{trans} form is more stable by 10$\pm$20 cm$^{-1}$ than the \textit{cis}.} \textbf{54} (1971), 260.} An in depth investigation into the \textit{cis} to \textit{trans} isomerization dynamics of CPCA for several C-H stretching modes will be presented. We will demonstrate the ability to record isomerization dynamics for CPCA as the laser scans using the IR-Chirped-Pulse FTMW Double resonance technique, which has been recently enhanced for improved sensitivity. Our broadband 7.5--18.5 GHz Chirped-Pulse FTMW spectrometer records the full rotational spectrum for every 0.01 cm$^{-1}$ step of the laser scan frequency. The improved sensitivity allows for detection of the many weak vibrationally excited rotational transitions. The lineshape profile of the excited state rotational spectrum is used to determine the \textit{cis}-\textit{trans} isomerization rate. The dynamics and resulting lineshape profiles vary depending on which infrared frequency is used to prepare the molecule

ULTRAVIOLET - CHIRPED PULSE FOURIER TRANSFORM MICROWAVE (UV-CPFTMW) DOUBLE-RESONANCE SPECTROSCOPY

Author Institution: Department of Chemistry, University of Virginia, McCormick Rd., P.O. Box 400319, Charlottesville, VA 22904The application of our broadband chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer for ultraviolet spectroscopy is presented.} \textbf{73} (2002), 165.} The CP-FTMW spectrometer has been coupled to a pulsed dye laser (0.025 cm$^{-1}$ bandwidth) to measure the ultraviolet spectra of various molecules. By using the CP-FTMW spectrometer as a detection device, rotationally-resolved ultraviolet spectra are recorded. Furthermore, since modulations of the pure rotational signals are monitored, the assignments of ultraviolet transitions to specific geometrical conformations are trivial once the pure rotational spectrum is assigned. A variety of UV-CPFTMW double-resonance techniques will be presented on representative molecules