Measuring Anisotropies in the Cosmic Neutrino Background

Neutrino capture on tritium has emerged as a promising method for detecting the cosmic neutrino background (CvB). We show that relic neutrinos are captured most readily when their spin vectors are anti-aligned with the polarization axis of the tritium nuclei and when they approach along the direction of polarization. As a result, CvB observatories may measure anisotropies in the cosmic neutrino velocity and spin distributions by polarizing the tritium targets. A small dipole anisotropy in the CvB is expected due to the peculiar velocity of the lab frame with respect to the cosmic frame and due to late-time gravitational effects. The PTOLEMY experiment, a tritium observatory currently under construction, should observe a nearly isotropic background. This would serve as a strong test of the cosmological origin of a potential signal. The polarized-target measurements may also constrain non-standard neutrino interactions that would induce larger anisotropies and help discriminate between Majorana versus Dirac neutrinos.Comment: 7 pages, 2 figure

The Influence of the Length of the Instructional Day on the Percentage of Proficient and Advanced Proficient Scores of the New Jersey Assessment of Skills and Knowledge for Grades 6, 7, and 8.

This study was relational, non-experimental, explanatory, and cross-sectional in nature, using quantitative methods to explain the influence of student, staff, and school independent variables on 6th, 7th, and 8th grade student achievement in both Language Arts and Mathematics on the 2011 NJ ASK. The variable of interest was the length of the instructional day and controlled student, staff, and school variables. This study provides descriptive research on the relationship between the length of the instructional day and other predictor variables and student achievement. The study used approximately 200 schools for each grade level and subject area combination. The percentage of students eligible for free and reduced lunch (%FRL) was found to be the strongest predictor on the 2011 NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8 in this study. Student attendance was also found to be a statistically significant predictor of the percentage of students scoring Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8. There is no statistically significant relationship between the length of the instructional day and the percentage of students Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics scores for Grades 6, 7, and 8

The Influence of the Length of the Instructional Day on the Percentage of Proficient and Advanced Proficient Scores of the New Jersey Assessment of Skills and Knowledge for Grades 6, 7, and 8.

This study was relational, non-experimental, explanatory, and cross-sectional in nature, using quantitative methods to explain the influence of student, staff, and school independent variables on 6th, 7th, and 8th grade student achievement in both Language Arts and Mathematics on the 2011 NJ ASK. The variable of interest was the length of the instructional day and controlled student, staff, and school variables. This study provides descriptive research on the relationship between the length of the instructional day and other predictor variables and student achievement. The study used approximately 200 schools for each grade level and subject area combination. The percentage of students eligible for free and reduced lunch (%FRL) was found to be the strongest predictor on the 2011 NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8 in this study. Student attendance was also found to be a statistically significant predictor of the percentage of students scoring Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8. There is no statistically significant relationship between the length of the instructional day and the percentage of students Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics scores for Grades 6, 7, and 8

Epidemiology of adolescent rugby injuries: a systematic review

OBJECTIVE: Despite recent increases in the volume of research in professional rugby union, there is little consensus on the epidemiology of injury in adolescent players. We undertook a systematic review to determine the incidence, severity, and nature of injury in adolescent rugby union players. DATA SOURCES: In April 2009, we performed a computerized literature search on PubMed, Embase, and Cochrane Controlled Trials Register (via Ovid). Population-specific and patient-specific search terms were combined in the form of MEDLINE subject headings and key words (wound$and injur$, rugby, adolescent$). These were supplemented with related-citation searches on PubMed and bibliographic tracking of primary and review articles. STUDY SELECTION: Prospective epidemiologic studies in adolescent rugby union players. DATA SYNTHESIS: A total of 15 studies were included, and the data were analyzed descriptively. Two independent reviewers extracted key study characteristics regarding the incidence, severity, and nature of injuries and the methodologic design. CONCLUSIONS: Wide variations existed in the injury definitions and data collection procedures. The incidence of injury necessitating medical attention varied with the definition, from 27.5 to 129.8 injuries per 1000 match hours. The incidence of time-loss injury (>7 days) ranged from 0.96 to 1.6 per 1000 playing hours and from 11.4/1000 match hours (>1 day) to 12–22/1000 match hours (missed games). The highest incidence of concussion was 3.3/1000 playing hours. No catastrophic injuries were reported. The head and neck, upper limb, and lower limb were all common sites of injury, and trends were noted toward greater time loss due to upper limb fractures or dislocations and knee ligament injuries. Increasing age, the early part of the playing season, and the tackle situation were most closely associated with injury. Future injury-surveillance studies in rugby union must follow consensus guidelines to facilitate interstudy comparisons and provide further clarification as to where injury- prevention strategies should be focused

Leaching losses from Kenyan maize cropland receiving different rates of nitrogen fertilizer

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nutrient Cycling in Agroecosystems 108 (2017): 195–209, doi:10.1007/s10705-017-9852-z.Meeting food security requirements in sub-Saharan Africa (SSA) will require increasing fertilizer use to improve crop yields, however excess fertilization can cause environmental and public health problems in surface and groundwater. Determining the threshold of reasonable fertilizer application in SSA requires an understanding of flow dynamics and nutrient transport in under-studied, tropical soils experiencing seasonal rainfall. We estimated leaching flux in Yala, Kenya on a maize field that received from 0 to 200 kg ha−1 of nitrogen (N) fertilizer. Soil pore water concentration measurements during two growing seasons were coupled with results from a numerical fluid flow model to calculate the daily flux of nitrate-nitrogen (NO3−-N). Modeled NO3−-N losses to below 200 cm for 1 year ranged from 40 kg N ha−1 year−1 in the 75 kg N ha−1 year−1 treatment to 81 kg N ha−1 year−1 in the 200 kg N ha−1 treatment. The highest soil pore water NO3−-N concentrations and NO3−-N leaching fluxes occurred on the highest N application plots, however there was a poor correlation between N application rate and NO3−-N leaching for the remaining N application rates. The drought in the second study year resulted in higher pore water NO3−-N concentrations, while NO3−-N leaching was disproportionately smaller than the decrease in precipitation. The lack of a strong correlation between NO3−-N leaching and N application rate, and a large decrease in flux between 120 and 200 cm suggest processes that influence NO3−-N retention in soils below 200 cm will ultimately control NO3−-N leaching at the watershed scale.Earth Institute, Columbia University; National Science Foundation IIA-0968211; Bill and Melinda Gates Foundatio

Particle Flow with a Hybrid Segmented Crystal and Fiber Dual-Readout Calorimeter

In the reconstruction of physics events at future e$^+$e$^-$ colliders the calorimeter design has a crucial role in the overall detector performance. The reconstruction of events with many jets in their final state sets stringent requirements on the jet energy and angular resolutions. The energy resolution for jets with energy of about 45 GeV is required to be at the 4-5\% level to enable an efficient separation of the W and Z boson invariant masses. We demonstrate in this paper how such a performance can be achieved by exploiting a particle flow algorithm tailored for a hybrid dual-readout calorimeter made of segmented crystals and fibers. The excellent energy resolution and linearity of such calorimeter for both photons and neutral hadrons ($3\%/\sqrt{E}$ and $26\%/\sqrt{E}$, respectively), inherent to the homogeneous crystals and dual-readout technological choices, provides a powerful handle for the development of a new approach for particle identification and jet reconstruction. While the dual-readout particle flow algorithm (DR-PFA) presented in this paper is at its early stage of development, it already demonstrates the potential of a hybrid dual-readout calorimeter for jet reconstruction by improving the jet energy resolution with respect to a calorimeter-only reconstruction from 6.0\% to about 4.5\% for 45 GeV jets

PKS 1830-211: A Face-On Spiral Galaxy Lens

We present new Hubble Space Telescope images of the gravitational lens PKS 1830-211, which allow us to characterize the lens galaxy and update the determination of the Hubble constant from this system. The I-band image shows that the lens galaxy is a face-on spiral galaxy with clearly delineated spiral arms. The southwestern image of the background quasar passes through one of the spiral arms, explaining the previous detections of large quantities of molecular gas and dust in front of this image. The lens galaxy photometry is consistent with the Tully-Fisher relation, suggesting the lens galaxy is a typical spiral galaxy for its redshift. The lens galaxy position, which was the main source of uncertainty in previous attempts to determine H_0, is now known precisely. Given the current time delay measurement and assuming the lens galaxy has an isothermal mass distribution, we compute H_0 = 44 +/- 9 km/s/Mpc for an Omega_m = 0.3 flat cosmological model. We describe some possible systematic errors and how to reduce them. We also discuss the possibility raised by Courbin et al. (2002), that what we have identified as a single lens galaxy is actually a foreground star and two separate galaxies.Comment: 21 pp., 4 figs., accepted by ApJ, section added to discuss related work by Courbin et al. (astro-ph/0202026