3,878 research outputs found
Mapping E-Commerce Locally and Beyond: CITT K12 Special Investigation Project
As all aspects of the American workplace become automated or digitally enhanced to some degree, K12 educators have an increasing responsibility to help their students acquire the technical skills necessary to organize and interpret information. Increasingly, this is done through Geographic Information Systems (GIS), especially in careers related to transportation and logistics. The Center for International Trade & Transportation (CITT) at CSU Long Beach has developed this K12 Special Investigation Project to introduce ArcGIS StoryMaps, an engaging, accessible and sophisticated web-based GIS application. The lessons center on e-commerce and its accompanying environmental and economic impact. Still, the activities can be easily adapted to projects in any subject area, such as humanities, science, math, or language arts. This teacher blueprint includes a teacher training guide with ten detailed lesson plans and activities. With the guidance of a National Board-Certified Teacher in Early Adolescence Math as lead instructor, the curriculum is designed to align with Next Generation Science Standards (NGSS). Also, exploration of STEM and GIS-related careers are incorporated into the lesson plans
Impactor flux and cratering on Ceres and Vesta: Implications for the early Solar System
We study the impactor flux and cratering on Ceres and Vesta caused by the
collisional and dynamical evolution of the asteroid Main Belt. We develop a
statistical code based on a well-tested model for the simultaneous evolution of
the Main Belt and NEA size distributions. This code includes catastrophic
collisions and noncollisional removal processes such as the Yarkovsky effect
and the orbital resonances. The model assumes that the dynamical depletion of
the early Main Belt was very strong, and owing to that, most Main Belt
comminution occurred when its dynamical structure was similar to the present
one. Our results indicate that the number of D > 1 km Main Belt asteroids
striking Ceres and Vesta over the Solar System history are approximately 4 600
and 1 100 respectively. The largest Main Belt asteroids expected to have
impacted Ceres and Vesta had diameters of 71.7 km and 21.1 km. The number of D
> 0.1 km craters on Ceres is \sim 3.4 \times 10^8 and 6.2 \times 10^7 on Vesta.
The number of craters with D > 100 km are 47 on Ceres and 8 on Vesta. Our study
indicates that the D = 460 km crater observed on Vesta had to be formed by the
impact of a D \sim 66.2 km projectile, which has a probability of occurr \sim
30% over the Solar System history. If significant discrepancies between our
results about the cratering on Ceres and Vesta and data obtained from the Dawn
Mission were found, they should be linked to a higher degree of collisional
evolution during the early Main Belt and/or the existence of the late heavy
bombardment. An increase in the collisional activity in the early phase may be
provided for an initial configuration of the giant planets consistent with, for
example, the Nice model. From this, the Dawn Mission would be able to give us
clues about the initial configuration of the early Solar System and its
subsequent dynamical evolution.Comment: Accepted for publication in Astronomy and Astrophysic
Observation of quantum interference as a function of Berry's phase in a complex Hadamard optical network
Emerging models of quantum computation driven by multi-photon quantum
interference, while not universal, may offer an exponential advantage over
classical computers for certain problems. Implementing these circuits via
geometric phase gates could mitigate requirements for error correction to
achieve fault tolerance while retaining their relative physical simplicity. We
report an experiment in which a geometric phase is embedded in an optical
network with no closed-loops, enabling quantum interference between two photons
as a function of the phase.Comment: Comments welcom
High throughput genomic sequencing of bioaerosols in broiler chicken production facilities
Chronic inhalation exposure to agricultural dust promotes the development of chronic respiratory diseases among poultry workers. Poultry dust is composed of dander, chicken feed, litter bedding and microbes. However, the microbial composition and abundance has not been fully elucidated. Genomic DNA was extracted from settled dust and personal inhalable dust collected while performing litter sampling or mortality collection tasks. DNA libraries were sequenced using a paired-end sequencing-by-synthesis approach on an Illumina HiSeq 2500. Sequencing data showed that poultry dust is predominantly composed of bacteria (64â67%) with a small quantity of avian, human and feed DNA (\u3c 2% of total reads). Staphylococcus sp. AL1, Salinicoccus carnicancri and Lactobacillus crispatus were the most abundant bacterial species in personal exposure samples of inhalable dust. Settled dust had a moderate relative abundance of these species as well as Staphylococcus lentus and Lactobacillus salivarius. There was a statistical difference between the microbial composition of aerosolized and settled dust. Unlike settled dust composition, aerosolized dust composition had little variance between samples. These data provide an extensive analysis of the microbial composition and relative abundance in personal inhalable poultry dust and settled poultry dust
Lens or Binary? Chandra Observations of the Wide Separation Broad Absorption Line Quasar Pair UM425
We have obtained a 110 ksec Chandra ACIS-S exposure of UM425, a pair of QSOs
at z=1.47 separated by 6.5 arcsec, which show remarkably similar emission and
broad absorption line (BAL) profiles in the optical/UV. Our 5000 count X-ray
spectrum of UM425A (the brighter component) is well-fit with a power law
(photon spectral index Gamma=2.0) partially covered by a hydrogen column of
3.8x10^22 cm^-2. The underlying power-law slope for this object and for other
recent samples of BALQSOs is typical of radio-quiet quasars, lending credence
to the hypothesis that BALs exist in every quasar. Assuming the same Gamma for
the much fainter image of UM425B, we detect an obscuring column 5 times larger.
We search for evidence of an appropriately large lensing mass in our Chandra
image and find weak diffuse emission near the quasar pair, with an X-ray flux
typical of a group of galaxies at redshift z ~ 0.6. From our analysis of
archival HST WFPC2 and NICMOS images, we find no evidence for a luminous
lensing galaxy, but note a 3-sigma excess of galaxies in the UM425 field with
plausible magnitudes for a z=0.6 galaxy group. However, the associated X-ray
emission does not imply sufficient mass to produce the observed image
splitting. The lens scenario thus requires a dark (high M/L ratio) lens, or a
fortuitous configuration of masses along the line of sight. UM425 may instead
be a close binary pair of BALQSOs, which would boost arguments that
interactions and mergers increase nuclear activity and outflows.Comment: 13 pages, 9 figures, Accepted for publication in the Astrophysical
Journa
Critical Issues in Trucking Workforce Development
This white paper identifies research opportunities focused on workforce development for the trucking industry, particularly regarding truck drivers and the truck driver shortage. Interviews were conducted with key national and state trucking industry leaders. In addition, the authors gathered information from relevant sessions at the Transportation Research Board (TRB) Annual Meeting in January of 2020. The researchers also synthesized recent literature related to the trucking industry and workforce development. Key findings indicate that 1) the shortage may be a byproduct of âchurn,â where truck drivers are leaving not the industry, but their respective companies for other companies, which creates a capacity issue rather than a shortage of drivers; 2) Those entering the truck driving profession tend to be in their 30s with previous work experience not in the industry; 3) Trucking automation and platooning are far in the horizon and will not affect the demand for truck drivers; and 4) With new technology required for transparency, speed, accuracy, and collaboration in transportation and logistics, new workforce training opportunities are needed for trucking establishments. Implications for policy and practice include developing marketing, training, and retention strategies specific to this entering demographic of truck drivers and creating more accurate messaging to the public about the future of trucking industry jobs. Note that this research was conducted before the COVID-19 shelter-in-place policies were mandated
In vivo measurements of muscle specific tension in adults and children
This article is available open access through the publisherâs website at the link below. Copyright @ 2009 The Authors.To better understand the effects of pubertal maturation on the contractile properties of skeletal muscle in vivo, the present study investigated whether there are any differences in the specific tension of the quadriceps muscle in 20 adults and 20 prepubertal children of both sexes. Specific tension was calculated as the ratio between the quadriceps tendon force and the sum of the physiological cross-sectional area (PCSA) multiplied by the cosine of the angle of pennation of each head within the quadriceps muscle. The maximal quadriceps tendon force was calculated from the knee extension maximal voluntary contraction (MVC) by accounting for EMG-based estimates of antagonist co-activation, incomplete quadriceps activation using the interpolation twitch technique and magnetic resonance imaging (MRI)-based measurements of the patellar tendon moment arm. The PCSA was calculated as the muscle volume, measured from MRI scans, divided by optimal fascicle length, measured from ultrasound images during MVC at the estimated angle of peak quadriceps muscle force. It was found that the quadriceps tendon force and PCSA of men (11.4 kN, 214 cm2) were significantly greater than those of the women (8.7 kN, 152 cm2; P 0.05) between groups: men, 55 ± 11 N cmâ2; women, 57.3 ± 13 N cmâ2; boys, 54 ± 14 N cmâ2; and girls, 59.8 ± 15 N cmâ2. These findings indicate that the increased muscle strength with maturation is not due to an increase in the specific tension of muscle; instead, it can be attributed to increases in muscle size, moment arm length and voluntary activation level
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