Database Integration Correlates Street Crossing Design Strategies With Pedestrian Injury.

INTRODUCTION: Transportation databases have limited data regarding injury severity of pedestrian versus automobile patients. To identify opportunities to reduce injury severity, transportation and trauma databases were integrated to examine the differences in pedestrian injury severity at street crossings that were signalized crossings (SCs) versus nonsignalized crossings (NSCs). It was hypothesized that trauma database integration would enhance safety analysis and pedestrians struck at NSC would have greater injury severity. METHODS: Single-center retrospective review of all pedestrian versus automobile patients treated at a level 1 trauma center from 2014 to 2018 was performed. Patients were matched to the transportation database by name, gender, and crash date. Google Earth Pro satellite imagery was used to identify SC versus NSC. Injury severity of pedestrians struck at SC was compared to NSC. RESULTS: A total of 512 patients were matched (median age = 41 y [Q1 = 26, Q3 = 55], 74% male). Pedestrians struck at SC (n = 206) had a lower injury severity score (ISS) (median = 9 [4, 14] versus 17 [9, 26], P < 0.001), hospital length of stay (median = 3 [0, 7] versus 6 [1, 15] days, P < 0.001), and mortality (21 [10%] versus 52 [17%], P = 0.04), as compared to those struck at NSC (n = 306). The transportation database had a sensitivity of 63.4% (55.8%-70.4%) and specificity of 63.4% (57.7%-68.9%) for classifying severe injuries (ISS >15). CONCLUSIONS: Pedestrians struck at SC were correlated with a lower ISS and mortality compared to those at NSC. Linkage with the trauma database could increase the transportation database's accuracy of injury severity assessment for nonfatal injuries. Database integration can be used for evidence-based action plans to reduce pedestrian morbidity, such as increasing the number of SC.

Adaptation in Outbred Sexual Yeast is Repeatable, Polygenic and Favors Rare Haplotypes.

We carried out a 200 generation Evolve and Resequence (E&R) experiment initiated from an outbred diploid recombined 18-way synthetic base population. Replicate populations were evolved at large effective population sizes (>105 individuals), exposed to several different chemical challenges over 12 weeks of evolution, and whole-genome resequenced. Weekly forced outcrossing resulted in an average between adjacent-gene per cell division recombination rate of ∼0.0008. Despite attempts to force weekly sex, roughly half of our populations evolved cheaters and appear to be evolving asexually. Focusing on seven chemical stressors and 55 total evolved populations that remained sexual we observed large fitness gains and highly repeatable patterns of genome-wide haplotype change within chemical challenges, with limited levels of repeatability across chemical treatments. Adaptation appears highly polygenic with almost the entire genome showing significant and consistent patterns of haplotype change with little evidence for long-range linkage disequilibrium in a subset of populations for which we sequenced haploid clones. That is, almost the entire genome is under selection or drafting with selected sites. At any given locus adaptation was almost always dominated by one of the 18 founder's alleles, with that allele varying spatially and between treatments, suggesting that selection acts primarily on rare variants private to a founder or haplotype blocks harboring multiple mutations.

Genistein and coumestrol reduce MCF-7 breast cancer cell viability and inhibit markers of preferential metastasis, bone matrix attachment and tumor-induced osteoclastogenesis.

The propensity of breast cancer to preferentially metastasize to the skeleton is well known. Once established in bone metastatic breast cancers have a poor prognosis due to their ability to promote extensive bone loss which augments tumor burden. Unfortunately, current anti-resorptive therapies for skeletal metastasis are typically prescribed after secondary tumors have formed and are palliative in nature. One group of compounds with the potential to reduce both tumor burden and osteolysis are phytoestrogens (PE), but the mechanisms mediating a beneficial effect are unclear. Therefore, the current study examined the effect of genistein and coumestrol alone or in combination on breast cancer cell number, expression of mediators of preferential skeletal metastasis, bone matrix attachment and tumor-induced osteoclast formation. Results showed that genistein and coumestrol significantly reduced viable cell number in an estrogen receptor dependent manner (p < 0.05), whereas combinations of PE had no effect. In addition, genistein and coumestrol significantly reduced expression of genes driving epithelial to mesenchymal transition (snail), bone attachment (CXCR4 and integrin αV) and osteolysis (PTHrP and TNF-α). In keeping with this genistein and coumestrol significantly suppressed attachment of breast cancer cells to bone matrix and inhibited tumor and RANKL-induced osteoclast formation. Our data suggests that phytoestrogens not only decrease breast cancer cell viability but also antagonize essential tumor bone interactions that establish and drive the progression of skeletal metastasis.

Isolation of Arabidopsis extracellular ATP binding proteins by affinity proteomics and identification of PHOSPHOLIPASE C-LIKE 1 as an extracellular protein essential for fumonisin B1 toxicity.

ATP is secreted to the extracellular matrix, where it activates plasma membrane receptors for controlling plant growth and stress-adaptive processes. DOES NOT RESPOND TO NUCLEOTIDES 1 (DORN1), was the first plant ATP receptor to be identified but key downstream proteins remain sought after. Here, we identified 120 proteins secreted by Arabidopsis cell cultures and screened them for putative stress-responsive proteins using ATP-affinity purification. We report three Arabidopsis proteins isolated by ATP-affinity: PEROXIDASE 52, SUBTILASE-LIKE SERINE PROTEASE 1.7 and PHOSPHOLIPASE C-LIKE 1. In wild-type Arabidopsis, the expression of genes encoding all three proteins responded to fumonisin B1, a cell death-activating mycotoxin. The expression of PEROXIDASE 52 and PHOSPHOLIPASE C-LIKE 1 was altered in fumonisin B1-resistant salicylic acid induction-deficient (sid2) mutants. Exposure to fumonisin B1 suppressed PHOSPHOLIPASE C-LIKE 1 expression in sid2 mutants, suggesting that the inactivation of this gene might provide mycotoxin tolerance. Accordingly, gene knockout mutants of PHOSPHOLIPASE C-LIKE 1 were resistant to fumonisin B1-induced death. The activation of PHOSPHOLIPASE C-LIKE 1 gene expression by exogenous ATP was not blocked in dorn1 loss-of-function mutants, indicating that DORN1 is not required. Furthermore, exogenous ATP rescued both the wild type and the dorn1 mutants from fumonisin-B1 toxicity, suggesting that different ATP receptor(s) are operational in this process. Our results point to the existence of additional plant ATP receptor(s) and provide crucial downstream targets for use in designing screens to identify these receptors. Finally, PHOSPHOLIPASE C-LIKE 1 serves as a convergence point for fumonisin B1 and extracellular ATP signalling, and functions in the Arabidopsis stress response to fumonisin B1.

High usage of medial unicompartmental knee arthroplasty negatively influences total knee arthroplasty revision rate.

PURPOSE: Surgeons with higher medial unicompartmental knee arthroplasty (UKA) usage have lower UKA revision rates. However, an increase in UKA usage may cause a decrease of total knee arthroplasty (TKA) usage. The purpose of this study was to investigate the influence of UKA usage on revision rates and patient-reported outcomes (PROMs) of UKA, TKA, and combined UKA + TKA results. METHODS: Using the New Zealand Registry Database, surgeons were divided into six groups based on their medial UKA usage: < 1%, 1-5%, 5-10%, 10-20%, 20-30% and > 30%. A comparison of UKA, TKA and UKA + TKA revision rates and PROMs using the Oxford Knee Score (OKS) was performed. RESULTS: A total of 91,895 knee arthroplasties were identified, of which 8,271 were UKA (9.0%). Surgeons with higher UKA usage had lower UKA revision rates, but higher TKA revision rates. The lowest TKA and combined UKA + TKA revision rates were observed for surgeons performing 1-5% UKA, compared to the highest TKA and UKA + TKA revision rates which were seen for surgeons using > 30% UKA (p < 0.001 TKA; p < 0.001 UKA + TKA). No clinically important differences in UKA + TKA OKS scores were seen between UKA usage groups at 6 months, 5 years, or 10 years. CONCLUSION: Surgeons with higher medial UKA usage have lower UKA revision rates; however, this comes at the cost of a higher combined UKA + TKA revision rate that is proportionate to the UKA usage. There was no difference in TKA + UKA OKS scores between UKA usage groups. A small increase in TKA revision rate was observed for high-volume UKA users (> 30%), when compared to other UKA usage clusters. A significant decrease in UKA revision rate observed in high-volume UKA surgeons offsets the slight increase in TKA revision rate, suggesting that UKA should be performed by specialist UKA surgeons. LEVEL OF EVIDENCE: III, Retrospective therapeutic study.

Beam energy metrics for the acceptance and quality assurance of Halcyon linear accelerator.

PURPOSE: Establish and compare two metrics for monitoring beam energy changes in the Halcyon platform and evaluate the accuracy of these metrics across multiple Halcyon linacs. METHOD: The first energy metric is derived from the diagonal normalized flatness (FDN ), which is defined as the ratio of the average measurements at a fixed off-axis equal distance along the open profiles in two diagonals to the measurement at the central axis with an ionization chamber array (ICA). The second energy metric comes from the area ratio (AR) of the quad wedge (QW) profiles measured with the QW on the top of the ICA. Beam energy is changed by adjusting the magnetron current in a non-clinical Halcyon. With D10cm measured in water at each beam energy, the relationships between FDN or AR energy metrics to D10cm in water is established with linear regression across six energy settings. The coefficients from these regressions allow D10cm (FDN ) calculation from FDN using open profiles and D10cm (QW) calculation from AR using QW profiles. RESULTS: Five Halcyon linacs from five institutions were used to evaluate the accuracy of the D10cm (FDN ) and the D10cm (QW) energy metrics by comparing to the D10cm values computed from the treatment planning system (TPS) and D10cm measured in water. For the five linacs, the D10cm (FDN ) reported by the ICA based on FDN from open profiles agreed with that calculated by TPS within -0.29 ± 0.23% and 0.61% maximum discrepancy; the D10cm (QW) reported by the QW profiles agreed with that calculated by TPS within -0.82 ± 1.27% and -2.43% maximum discrepancy. CONCLUSION: The FDN -based energy metric D10cm (FDN ) can be used for acceptance testing of beam energy, and also for the verification of energy in periodic quality assurance (QA) processes.

Intraosseous Regional Administration of Vancomycin in Primary Total Knee Arthroplasty Does Not Increase the Risk of Vancomycin-Associated Complications.

BACKGROUND: Periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is a rare but major complication. Owing to an increasing antibiotic resistance in bacteria causing PJI, vancomycin has been investigated as a prophylactic agent. Intraosseous regional administration (IORA) of vancomycin achieves significantly higher local tissue concentrations than systemic administration. There are limited data on IORA of vancomycin with respect to vancomycin-associated complications. METHODS: Single-surgeon retrospective review of primary TKA was performed between January 2015 and May 2019. All patients received 500 mg of IORA of vancomycin after tourniquet inflation and 3 × 1 g intravenous cefazolin in 24 hrs. Preoperative data collected included age, gender, body mass index, American Society of Anesthesiologists (ASA) score, diabetes, and chronic kidney disease (CKD). We documented in-hospital complications and complications requiring readmission within 12 months. Primary outcome measures were the incidence of acute kidney injury (AKI), 'red man syndrome' (RMS), and neutropenia. The secondary outcome measure was PJI incidence. RESULTS: We identified 631 primary TKAs in 556 patients, of which 331 received IORA. The mean age was 67.7 ± 8.7 years, and 57.8% were women. CKD was prevalent in 17.2% of the cohort. AKI occurred in 25 (3.9%) cases. After controlling for covariates, CKD was the only significant predictor of AKI (odds ratio = 3.035, P = .023). RMS and neutropenia were not observed in this cohort. The 90-day PJI rate was 0%, and the 1-year PJI rate was 0.2%. CONCLUSIONS: Low-dose IORA of vancomycin in addition to standard intravenous systemic cefazolin prophylaxis in TKA is safe without significant adverse effects of vancomycin such as AKI, RMS, or neutropenia.

Monitoring linear accelerators electron beam energy constancy with a 2D ionization chamber array and double-wedge phantom.

Validate that a two-dimensional (2D) ionization chamber array (ICA) combined with a double-wedge plate (DWP) can track changes in electron beam energy well within 2.0 mms as recommended by TG-142 for monthly quality assurance (QA). Electron beam profiles of 4-22 MeV were measured for a 25 × 25 cm2 cone using an ICA with a DWP placed on top of it along one diagonal axis. The relationship between the full width half maximum (FWHM) field size created by DWP energy degradation across the field and the depth of 50% dose in water (R50 ) is calibrated for a given ICA/DWP combination in beams of know energies (R50 values). Once this relationship is established, the ICA/DWP system will report the R50 FWHM directly. We calibrated the ICA/DWP on a linear accelerator with energies of 6, 9, 12, 16, 20, and 22 MeV. The R50 FWHM values of these beams and eight other beams with different R50 values were measured and compared with the R50 measured in water, that is, R50 Water. Resolving changes of R50 up to 0.2 cm with ICA/DWP was tested by adding solid-water to shift the energy and was verified with R50 Water measurements. To check the long-term reproducibility of ICA/DWP we measured R50 FWHM on a monthly basis for a period of 3 yr. We proposed a universal calibration procedure considering the off-axis corrections and compared calibrations and measurements on three types of linacs (Varian TrueBeam, Varian C-series, and Elekta) with different nominal energies and R50 values. For all 38 beams on same type of linac with R50 values over a range of 2-8.8 cm, the R50 FWHM reported by the ICA/DWP system agreed with that measured in water within 0.01 ± 0.03 cm (mean ± 1σ) and maximum discrepancy of 0.07 cm. Long-term reproducibility results show the ICA/DWP system to be within 0.04 cm of their baseline over 3 yr. With the universal calibration the maximum discrepancy between R50 FWHM and R50 Water for different types of linac reduced from 0.25 to 0.06 cm. Comparison of R50 FWHM values and R50 Water values and long-term reproducibility of R50 FWHM values indicates that the ICA/DWP can be used for monitoring of electron beam energy constancy well within TG-142 recommended tolerance.

Acceptance and verification of the Halcyon-Eclipse linear accelerator-treatment planning system without 3D water scanning system.

We tested whether an ionization chamber array (ICA) and a one-dimensional water scanner (1DS) could be used instead of a three-dimensional water scanning system (3DWS) for acceptance testing and commissioning verification of the Varian Halcyon-Eclipse Treatment Planning System (TPS). The Halcyon linear accelerator has a single 6-MV flattening-filter-free beam and a nonadjustable beam model for the TPS. Beam data were measured with a 1DS, ICA, ionization chambers, and electrometer. Acceptance testing and commissioning were done simultaneously by comparing the measured data with TPS-calculated percent-depth-dose (PDD) and profiles. The ICA was used to measure profiles of various field sizes (10-, 20-, and 28 cm2 ) at depths of dmax (1.3 cm), 5-, 10-, and 20 cm. The 1DS was used for output factors (OFs) and PDDs. OFs were measured with 1DS for various fields (2-28 cm2 ) at a source-to-surface distance of 90 cm. All measured data were compared with TPS-calculations. Profiles, off-axis ratios (OAR), PDDs and OFs were also measured with a 3DWS as a secondary check. Profiles between the ICA and TPS (ICA and 3DWS) at various depths across the fields indicated that the maximum discrepancies in high-dose and low-dose tail were within 2% and 3%, respectively, and the maximum distance-to-agreement in the penumbra region was <3 mm. The largest OAR differences between ICA and TPS (ICA and 3DWS) values were 0.23% (-0.25%) for a 28 × 28 cm2 field, and the largest point-by-point PDD differences between 1DS and TPS (1DS and 3DWS) were -0.41% ± 0.12% (-0.32% ± 0.17%) across the fields. Both OAR and PDD showed the beam energy is well matched to the TPS model. The average ratios of 1DS-measured OFs to the TPS (1DS to 3DWS) values were 1.000 ± 0.002 (0.999 ± 0.003). The Halcyon-Eclipse system can be accepted and commissioned without the need for a 3DWS.

Quantification of beam steering with an ionization chamber array.

Routine quality assurance for linear accelerators (linacs) usually involves verification of beam steering with a water scanning system. We established a beam steering procedure that uses a 2D ionization chamber array (ICA) and verified the equivalence of beam symmetry between the ICA and a water scanning system. The ICA calibration accuracy, reproducibility and stability were evaluated and the uncertainty in the measurement of beam symmetry due to the array calibration was examined. Forty-five photon beams and 80 electron beams across 7 Varian C-series and 4 TrueBeam linacs were steered in the radial and transverse directions using an ICA. After beam steering, profiles were re-measured using the ICA and in-water using a 3D Scanner (3DS). Beam symmetries measured with the ICA and 3DS were compared by (a) calculating the difference in point-by-point symmetry, (b) plotting the histogram distribution of the symmetry differences, and (c) comparing ICA and 3DS differences with their respective Varian symmetry protocol analysis. Array calibrations from five different occurrences (2012 to 2016) over six different beams reproduced within 0.5%. The uncertainty in beam symmetry was less than 0.5% due to the uncertainties in the array calibration. After all beams were steered using the ICA, the point-by-point symmetry differences between ICA and 3DS at the off-axis positions of 20% and 80% of field size for all beam profiles indicated that 95% of point-by-point symmetry comparisons agreed within 0.7%, and 100% agreed within 1.0%; after steering with the ICA 97.8% of photon beam profiles (88 of 90) and 97.5% of electron beam profiles (156 of 160) had symmetry within 1% when measured with the 3DS. All photon and electron beam profiles had symmetry within 1.1% and 1.2%, respectively, for profiles measured with the 3DS. Our data demonstrate that a calibrated ICA can be used to steer photon and electron beams achieving beam symmetry within 1% when re-measured with a 3D water scanning system.

A Novel Function for Arabidopsis CYCLASE1 in Programmed Cell Death Revealed by Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) Analysis of Extracellular Matrix Proteins.

Programmed cell death is essential for plant development and stress adaptation. A detailed understanding of the signal transduction pathways that regulate plant programmed cell death requires identification of the underpinning protein networks. Here, we have used a protagonist and antagonist of programmed cell death triggered by fumonisin B1 as probes to identify key cell death regulatory proteins in Arabidopsis. Our hypothesis was that changes in the abundance of cell death-regulatory proteins induced by the protagonist should be blocked or attenuated by concurrent treatment with the antagonist. We focused on proteins present in the mobile phase of the extracellular matrix on the basis that they are important for cell-cell communications during growth and stress-adaptive responses. Salicylic acid, a plant hormone that promotes programmed cell death, and exogenous ATP, which can block fumonisin B1-induced cell death, were used to treat Arabidopsis cell suspension cultures prior to isobaric-tagged relative and absolute quantitation analysis of secreted proteins. A total of 33 proteins, whose response to salicylic acid was suppressed by ATP, were identified as putative cell death-regulatory proteins. Among these was CYCLASE1, which was selected for further analysis using reverse genetics. Plants in which CYCLASE1 gene expression was knocked out by insertion of a transfer-DNA sequence manifested dramatically increased cell death when exposed to fumonisin B1 or a bacterial pathogen that triggers the defensive hypersensitive cell death. Although pathogen inoculation altered CYCLASE1 gene expression, multiplication of bacterial pathogens was indistinguishable between wild type and CYCLASE1 knockout plants. However, remarkably severe chlorosis symptoms developed on gene knockout plants in response to inoculation with either a virulent bacterial pathogen or a disabled mutant that is incapable of causing disease in wild type plants. These results show that CYCLASE1, which had no known function hitherto, is a negative regulator of cell death and regulates pathogen-induced symptom development in Arabidopsis.

A comparison of methods for monitoring photon beam energy constancy.

In extension of a previous study, we compared several photon beam energy metrics to determine which was the most sensitive to energy change; in addition to those, we accounted for both the sensitivity of each metric and the uncertainty in determining that metric for both traditional flattening filter (FF) beams (4, 6, 8, and 10 MV) and for flattening filter-free (FFF) beams (6 and 10 MV) on a Varian TrueBeam. We examined changes in these energy metrics when photon energies were changed to ± 5% and ± 10% from their nominal energies: 1) an attenuation-based metric (the percent depth dose at 10 cm depth, PDD(10)) and, 2) profile-based metrics, including flatness (Flat) and off-axis ratios (OARs) measured on the orthogonal axes or on the diagonals (diagonal normalized flatness, FDN). Profile-based metrics were measured near dmax and also near 10 cm depth in water (using a 3D scanner) and with ioniza-tion chamber array (ICA). PDD(10) was measured only in water. Changes in PDD, OAR, and FDN were nearly linear to the changes in the bend magnet current (BMI) over the range from -10% to +10% for both FF and FFF beams: a ± 10% change in energy resulted in a ± 1.5% change in PDD(10) for both FF and FFF beams, and changes in OAR and FDN were > 3.0% for FF beams and > 2.2% for FFF beams. The uncertainty in determining PDD(10) was estimated to be 0.15% and that for OAR and FDN about 0.07%. This resulted in minimally detectable changes in energy of 2.5% for PDD(10) and 0.5% for OAR and FDN. We found that the OAR- or FDN- based metrics were the best for detecting energy changes for both FF and FFF beams. The ability of the OAR-based metrics determined with a water scanner to detect energy changes was equivalent to that using an ionization chamber array. We recommend that OAR be measured either on the orthogonal axes or the diagonals, using an ionization chamber array near the depth of maximum dose, as a sensitive and efficient way to confirm stability of photon beam energy.

The crystal structure analysis of the relative binding of cisplatin and carboplatin in a mixture with histidine in a protein studied at 100 and 300 K with repeated X-ray irradiation.

The anticancer agents cisplatin and carboplatin bind to histidine in a protein. This crystal structure study at data-collection temperatures of 100 and 300 K examines their relative binding affinities to a histidine side chain and the effect of a high X-ray radiation dose of up to ∼1.8 MGy on the stability of the subsequent protein-Pt adducts. Cisplatin binding is visible at the histidine residue, but carboplatin binding is not. Five refined X-ray crystal structures are presented: one at 100 K as a reference and four at 300 K. The diffraction resolutions are 1.8, 2.0, 2.8, 2.9 and 3.5 Å.

Practical limitations of emergency donor panels as a risk mitigation in small-scale short-term training team operations.

Haemostatic resuscitation with blood products has become the expected standard of care for trauma casualties. As UK Defence increases its deployment of small-scale, short-term training teams (STTTs) in Defence Engagement and influence operations, ever greater reliance is being placed on emergency donor panels (EDP) as a source of whole blood. This paper outlines the practical limitations of using EDPs as a risk mitigation in conventional STTTs which must be considered prior to every deployment.

Characterization of a diode dosimeter for UHDR FLASH radiotherapy.

BACKGROUND: Ultra-high dose rate (UHDR) FLASH beams typically deliver dose at rates of  >40 Gy/sec. Characterization of these beams with respect to dose, mean dose rate, and dose per pulse requires dosimeters which exhibit high temporal resolution and fast readout capabilities. PURPOSE: A diode EDGE Detector with a newly designed electrometer has been characterized for use in an UHDR electron beam and demonstrated appropriateness for UHDR FLASH radiotherapy dosimetry. METHODS: Dose linearity, mean dose rate, and dose per pulse dependencies of the EDGE Detector were quantified and compared with dosimeters including a W1 scintillator detector, radiochromic film, and ionization chamber that were irradiated with a 10 MeV UHDR beam. The dose, dose rate, and dose per pulse were controlled via an in-house developed scintillation-based feedback mechanism, repetition rate of the linear accelerator, and source-to-surface distance, respectively. Depth-dose profiles and temporal profiles at individual pulse resolution were compared to the film and scintillation measurements, respectively. The radiation-induced change in response sensitivity was quantified via irradiation of ∼5kGy. RESULTS: The EDGE Detector agreed with film measurements in the measured range with varying dose (up to 70 Gy), dose rate (nearly 200 Gy/s), and dose per pulse (up to 0.63 Gy/pulse) on average to within 2%, 5%, and 1%, respectively. The detector also agreed with W1 scintillation detector on average to within 2% for dose per pulse (up to 0.78 Gy/pulse). The EDGE Detector signal was proportional to ion chamber (IC) measured dose, and mean dose rate in the bremsstrahlung tail to within 0.4% and 0.2% respectively. The EDGE Detector measured percent depth dose (PDD) agreed with film to within 3% and per pulse output agreed with W1 scintillator to within -6% to +5%. The radiation-induced response decrease was 0.4% per kGy. CONCLUSIONS: The EDGE Detector demonstrated dose linearity, mean dose rate independence, and dose per pulse independence for UHDR electron beams. It can quantify the beam spatially, and temporally at sub millisecond resolution. It's robustness and individual pulse detectability of treatment deliveries can potentially lead to its implementation for in vivo FLASH dosimetry, and dose monitoring.

CyclinD2-mediated regulation of neurogenic output from the retinal ciliary margin is perturbed in albinism.

In albinism, aberrations in the ipsi-/contralateral retinal ganglion cell (RGC) ratio compromise the functional integrity of the binocular circuit. Here, we focus on the mouse ciliary margin zone (CMZ), a neurogenic niche at the embryonic peripheral retina, to investigate developmental processes regulating RGC neurogenesis and identity acquisition. We found that the mouse ventral CMZ generates predominantly ipsilaterally projecting RGCs, but this output is altered in the albino visual system because of CyclinD2 downregulation and disturbed timing of the cell cycle. Consequently, albino as well as CyclinD2-deficient pigmented mice exhibit diminished ipsilateral retinogeniculate projection and poor depth perception. In albino mice, pharmacological stimulation of calcium channels, known to upregulate CyclinD2 in other cell types, augmented CyclinD2-dependent neurogenesis of ipsilateral RGCs and improved stereopsis. Together, these results implicate CMZ neurogenesis and its regulators as critical for the formation and function of the mammalian binocular circuit.

The probe-format graphite calorimeter, Aerrow, for absolute dosimetry in ultrahigh pulse dose rate electron beams.

PURPOSE: The purpose of this investigation is to evaluate the use of a probe-format graphite calorimeter, Aerrow, as an absolute and relative dosimeter of high-energy pulse dose rate (UHPDR) electron beams for in-water reference and depth-dose-type measurements, respectively. METHODS: In this paper, the calorimeter system is used to investigate the potential influence of dose per pulses delivered up to 5.6 Gy, the number of pulses delivered per measurement, and its potential for relative measurement (depth-dose curve measurement). The calorimeter system is directly compared against an Advanced Markus ion chamber. The finite element method was used to calculate heat transfer corrections along the percentage depth dose of a 20-MeV electron beam. Monte Carlo-calculated dose conversion factors necessary to calculate absorbed dose-to-water at a point from the measured dose-to-graphite are also presented. RESULTS: The comparison of Aerrow against a fully calibrated Advanced Markus chamber, corrected for the saturation effect, has shown consistent results in terms of dose-to-water determination. The measured reference depth is within 0.5 mm from the expected value from Monte Carlo simulation. The relative standard uncertainty estimated for Aerrow was 1.06%, which is larger compared to alanine dosimetry (McEwen et al. https://doi.org/10.1088/0026-1394/52/2/272) but has the advantage of being a real-time detector. CONCLUSION: In this investigation, it was demonstrated that the Aerrow probe-type graphite calorimeter can be used for relative and absolute dosimetries in water in an UHPDR electron beam. To the author's knowledge, this is the first reported use of an absorbed dose calorimeter for an in-water percentage depth-dose curve measurement. The use of the Aerrow in quasi-adiabatic mode has greatly simplified the signal readout, compared to isothermal mode, as the resistance was directly measured with a high-stability digital multimeter.

Wolbachia action in the sperm produces developmentally deferred chromosome segregation defects during the Drosophila mid-blastula transition.

Wolbachia, a vertically transmitted endosymbiont infecting many insects, spreads rapidly through uninfected populations by a mechanism known as cytoplasmic incompatibility (CI). In CI, a paternally delivered modification of the sperm leads to chromatin defects and lethality during and after the first mitosis of embryonic development in multiple species. However, whether CI-induced defects in later stage embryos are a consequence of the first division errors or caused by independent defects remains unresolved. To address this question, we focused on ~1/3 of embryos from CI crosses in Drosophila simulans that develop apparently normally through the first and subsequent pre-blastoderm divisions before exhibiting mitotic errors during the mid-blastula transition and gastrulation. We performed single embryo PCR and whole genome sequencing to find a large percentage of these developed CI-derived embryos bypass the first division defect. Using fluorescence in situ hybridization, we find increased chromosome segregation errors in gastrulating CI-derived embryos that had avoided the first division defect. Thus, Wolbachia action in the sperm induces developmentally deferred defects that are not a consequence of the first division errors. Like the immediate defect, the delayed defect is rescued through crosses to infected females. These studies inform current models on the molecular and cellular basis of CI.

Common evolutionary origin of acoustic communication in choanate vertebrates.

Acoustic communication, broadly distributed along the vertebrate phylogeny, plays a fundamental role in parental care, mate attraction and various other behaviours. Despite its importance, comparatively less is known about the evolutionary roots of acoustic communication. Phylogenetic comparative analyses can provide insights into the deep time evolutionary origin of acoustic communication, but they are often plagued by missing data from key species. Here we present evidence for 53 species of four major clades (turtles, tuatara, caecilian and lungfish) in the form of vocal recordings and contextual behavioural information accompanying sound production. This and a broad literature-based dataset evidence acoustic abilities in several groups previously considered non-vocal. Critically, phylogenetic analyses encompassing 1800 species of choanate vertebrates reconstructs acoustic communication as a homologous trait, and suggests that it is at least as old as the last common ancestor of all choanate vertebrates, that lived approx. 407 million years before present.

Proteomics reveals a role for the RNA helicase crhR in the modulation of multiple metabolic pathways during cold acclimation of Synechocystis sp. PCC6803.

One of the earliest and largest transcriptional responses that occur during exposure of Synechocystis sp. PCC6803 to cold is the induction of the crhR RNA helicase transcript. We show that crhR deletion results in failure to cold acclimate: there is reduced growth at 24 °C and marked impairment of growth at 20 °C. 2D-DIGE, using five biological replicates, was used to analyze the proteomic differences between the wild-type and ΔcrhR strains grown at (1) 34 °C and (2) following transfer from 34 to 24 °C (cold-acclimation). Sixteen significantly differentially expressed proteins were identified between the two strains grown at 34 °C. Forty-three distinct proteins were identified that responded to cold-acclimation of the wild-type and 34 proteins for the mutant, with only 26 proteins common to both. A large proportion of the proteomic responses (76.5%) could not be predicted from published transcriptomic data. Only modest similarity is observed between proteomic and transcriptomic responses (r = 0.54-0.70). We propose functions for three previously hypothetical proteins. We suggest molecular targets for CrhR action and identify downstream regulated events in metabolism.