Three-Prong Distribution of Massive Narrow QCD Jets

We study the planar-flow distributions of narrow, highly boosted, massive QCD jets. Using the factorization properties of QCD in the collinear limit, we compute the planar-flow jet function from the one-to-three splitting function at tree-level. We derive the leading-log behavior of the jet function analytically. We also compare our semi-analytic jet function with parton-shower predictions using various generators.Comment: 59 pages, 9 figure

Bcl-xL-mediated remodeling of rod and cone synaptic mitochondria after postnatal lead exposure: electron microscopy, tomography and oxygen consumption.

PurposePostnatal lead exposure produces rod-selective and Bax-mediated apoptosis, decreased scotopic electroretinograms (ERGs), and scotopic and mesopic vision deficits in humans and/or experimental animals. Rod, but not cone, inner segment mitochondria were considered the primary site of action. However, photoreceptor synaptic mitochondria were not examined. Thus, our experiments investigated the structural and functional effects of environmentally relevant postnatal lead exposure on rod spherule and cone pedicle mitochondria and whether Bcl-xL overexpression provided neuroprotection.MethodsC57BL/6N mice pups were exposed to lead only during lactation via dams drinking water containing lead acetate. The blood [Pb] at weaning was 20.6±4.7 µg/dl, which decreased to the control value by 2 months. To assess synaptic mitochondrial structural differences and vulnerability to lead exposure, wild-type and transgenic mice overexpressing Bcl-xL in photoreceptors were used. Electron microscopy, three-dimensional electron tomography, and retinal and photoreceptor synaptic terminal oxygen consumption (QO(2)) studies were conducted in adult control, Bcl-xL, lead, and Bcl-xL/lead mice.ResultsThe spherule and pedicle mitochondria in lead-treated mice were swollen, and the cristae structure was markedly changed. In the lead-treated mice, the mitochondrial cristae surface area and volume (abundance: measure correlated with ATP (ATP) synthesis) were decreased in the spherules and increased in the pedicles. Pedicles also had an increased number of crista segments per volume. In the lead-treated mice, the number of segments/crista and fraction of cristae with multiple segments (branching) similarly increased in spherule and pedicle mitochondria. Lead-induced remodeling of spherule mitochondria produced smaller cristae with more branching, whereas pedicle mitochondria had larger cristae with more branching and increased crista junction (CJ) diameter. Lead decreased dark- and light-adapted photoreceptor and dark-adapted photoreceptor synaptic terminal QO(2). Bcl-xL partially blocked many of the lead-induced alterations relative to controls. However, spherules still had partially decreased abundance, whereas pedicles still had increased branching, increased crista segments per volume, and increased crista junction diameter. Moreover, photoreceptor and synaptic QO(2) were only partially recovered.ConclusionsThese findings reveal cellular and compartmental specific differences in the structure and vulnerability of rod and cone inner segment and synaptic mitochondria to postnatal lead exposure. Spherule and pedicle mitochondria in lead-exposed mice displayed complex and distinguishing patterns of cristae and matrix damage and remodeling consistent with studies showing that synaptic mitochondria are more sensitive to Ca(2+) overload, oxidative stress, and ATP loss than non-synaptic mitochondria. The lead-induced decreases in QO(2) likely resulted from the decreased spherule cristae abundance and smaller cristae, perhaps due to Bax-mediated effects as they occurred in apoptotic rod inner segments. The increase in pedicle cristae abundance and CJ diameter could have resulted from increased Drp1-mediated fission, as small mitochondrial fragments were observed. The mechanisms of Bcl-xL-mediated remodeling might occur via interaction with formation of CJ protein 1 (Fcj1), whereas the partial protection of synaptic QO(2) might result from the enhanced efficiency of energy metabolism via Bcl-xL's direct interaction with the F1F0 ATP synthase and/or regulation of cellular redox status. These lead-induced alterations in photoreceptor synaptic terminal mitochondria likely underlie the persistent scotopic and mesopic deficits in lead-exposed children, workers, and experimental animals. Our findings stress the clinical and scientific importance of examining synaptic dysfunction following injury or disease during development, and developing therapeutic treatments that prevent synaptic degeneration in retinal and neurodegenerative disorders even when apoptosis is blocked

Classification of Energy Flow Observables in Narrow Jets

We present a classification of energy flow variables for highly collimated jets. Observables are constructed by taking moments of the energy flow and forming scalars of a suitable Lorentz subgroup. The jet shapes are naturally arranged in an expansion in both angular and energy resolution, allowing us to derive the natural observables for describing an N-particle jet. We classify the leading variables that characterize jets with up to 4 particles. We rediscover the familiar jet mass, angularities, and planar flow, which dominate the lowest order substructure variables. We also discover several new observables and we briefly discuss their physical interpretation.Comment: 11 pages and 1 figur

Affording to Wait: Medicare Initiation and the Use of Health Care

Delays in receipt of necessary diagnostic and therapeutic medical procedures related to the timing of Medicare initiation at age 65 years have potentially broad welfare implications. We use 2005–2007 data from Florida and North Carolina to estimate the effect of initiation of Medicare benefits on healthcare utilization across procedures that differ in urgency and coverage. In particular, we study trends in the use of elective procedures covered by Medicare to treat conditions that vary in symptoms; these are compared with elective surgical procedures not eligible for Medicare reimbursement, and to a set of urgent and emergent procedures. We find large discontinuities in health services utilization at age 65 years concentrated among low urgency, Medicare‐reimbursable procedures, most pronounced among screening interventions and treatments for minimally symptomatic disease

Report on the Verification of the Performance of MON87701 and MON89788 Event-specific Methods on the Soybean Event MON87701 x MON89788 Using Real-time PCR

The European Union Reference Laboratory for GM Food and Feed (EU-RL GMFF), established by Regulation (EC) No 1829/2003, has carried out an in-house verification study to assess the performance of two quantitative event-specific methods on the soybean event MON87701 x MON89788 (unique identifier MON-877Ø1-2 x MON-89788-1) which combines the MON87701 and the MON89788 transformation events. The two methods have been validated individually on single-trait events, to detect and quantify each event in soybean samples. This study was conducted according to internationally accepted guidelines (1, 2). In accordance to Regulation (EC) No 1829/2003 of 22 September 2003 on genetically modified food and feed and to Regulation (EC) No 641/2004 of 6 April 2004 on detailed rules for the implementation of Regulation (EC) No 1829/2003, Monsanto Company provided the detection methods and the control samples: genomic DNA from homogenised seeds of MON87701 x MON89788 soybean and from homogenised seeds of conventional soybean. The EU-RL GMFF prepared the verification samples (calibration samples and blind samples at different unknown GM percentages [DNA/DNA]). The results of the verification study were evaluated with reference to ENGL method performance requirements (http://gmo-crl.jrc.ec.europa.eu/guidancedocs.htm) and to the validation results on the individual parental events (http://gmo-crl.jrc.ec.europa.eu/statusofdoss.htm) The results of this EU-RL GMFF in-house verification studies are made publicly available at http://gmo-crl.jrc.ec.europa.eu/statusofdoss.htmJRC.I.3-Molecular Biology and Genomic

In-house validation of an Event-specific Method for the Quantification of Oliseed Rape RF2 using Real-time PCR

The European Union Reference Laboratory for GM Food and Feed (EU-RL GMFF), established by Regulation (EC) No 1829/2003, has carried out an in-house validation study to assess the performance of a quantitative event-specific method on the oilseed rape event RF2 (unique identifier ACS-BN002-5). In accordance to Regulation (EC) No 1829/2003 of 22 September 2003 on genetically modified food and feed and to Regulation (EC) No 641/2004 of 6 April 2004 on detailed rules for the implementation of Regulation (EC) No 1829/2003, Bayer CropScience provided the detection method and the control samples. The EU-RL GMFF prepared the validation samples [calibration samples and blind samples at different GM percentages (DNA/DNA)]. The results of the in-house validation were evaluated with respect to method acceptance criteria and method performance requirements recommended by the European Network of GMO Laboratories (ENGL) (http://gmocrl.jrc.ec.europa.eu/guidancedocs.htm) and to its applicability in different real-time PCR instruments. The results obtained indicate that the method complies with the ENGL criteria. The method is therefore considered applicable to the control samples provided, in accordance with the requirements of Annex I – 2.C.2 to Regulation (EC) No 641/2004.JRC.I.3-Molecular Biology and Genomic