Mosaicking with cosmic microwave background interferometers

Measurements of cosmic microwave background (CMB) anisotropies by interferometers offer several advantages over single-dish observations. The formalism for analyzing interferometer CMB data is well developed in the flat-sky approximation, valid for small fields of view. As the area of sky is increased to obtain finer spectral resolution, this approximation needs to be relaxed. We extend the formalism for CMB interferometry, including both temperature and polarization, to mosaics of observations covering arbitrarily large areas of the sky, with each individual pointing lying within the flat-sky approximation. We present a method for computing the correlation between visibilities with arbitrary pointing centers and baselines and illustrate the effects of sky curvature on the l-space resolution that can be obtained from a mosaic.Comment: 9 pages; submitted to Ap

Using Augmented Feedback to Decrease Patellofemoral Pain in Runners: A Pilot study

Objective: Patellofemoral pain (PFP) is a common injury in running. The cause of patellofemoral pain is multifactorial in nature, which results varied treatment approaches for this disorder. Many studies have examined the effect of using strengthening protocols targeted at subjects’ hip and quadriceps strength. Although these studies have resulted in a reduction in short-term PFP for runners, many continue to experience PFP after undergoing these treatment strategies. A more recent theory regarding the treatment of PFP in runners involves the use of augmented verbal and visual feedback. This treatment strategy involves giving the runner scheduled visual feedback to adapt their running strategies in hopes of reducing their PFP. Much of this research has been done with experienced runners in the age range of 18-22 years old. The purpose of this study was to examine the effects of augmented verbal and real-time visual feedback on patellofemoral pain. The hypothesis was that training with the use of auditory and visual feedback would improve patellofemoral pain in this runner. In clinical practice, auditory and visual feedback to change hip and knee mechanics while running may be used as a treatment strategy for patellofemoral pain. Design and Setting: The study was conducted in a controlled laboratory setting and was an experimental design including a single-subject. Participants: The subject was a recreational female runner that was 22 years of age. The subject was recruited via a flyer distributed on campus. Once the individual agreed to participate, they were given a date to begin the study. This study was approved by the Institutional Review Board at the institution. When the subject arrived at the first meeting, the informed consent was reviewed and signed by the subject. Intervention: At the first visit, the subject was given a PFP questionnaire to determine if they were eligible for the study. For this study, the subject was classified as having PFP if they had pre-patellar or retropatellar knee pain while running that was an insidious onset, and knee pain that has lasted for at least three months. The subject also needed these symptoms to occur during two of the following functional activities: ascending/descending stairs, squatting, kneeling, jumping, and long periods of sitting. Subjects were excluded from the study if they exhibited any type of neurological disorder, injury to the lower extremity, previous surgeries involving the lower extremity, rheumatoid arthritis, heart conditions, or any other knee pathologies including patellar instability, patellofemoral dysplasia, meniscal or ligament tears, osteoarthritis, or tendinopathies. Once the subject met the inclusion criteria, they completed a visual analog scale (VAS) and a lower extremity functional scale survey (LEFS) to assess their function. The subject completed 2 training sessions per week for a total of 8 training sessions on a treadmill. During the run, an iPad was used to capture an anterior view of the subject. This image was mirrored to a television monitor to provide the subject with real time visual feedback of their running. For each session, the subject was given a five-minute warm-up at their self-selected running speed and was then asked to move to a speed that they were comfortable with running 25 minutes. This speed was constant throughout the entire study. The augmented verbal and visual feedback was given based on a schedule of “on” times and “off” times. The “on” times for the feedback stayed at a constant one minute where the “off” times became progressively longer. Main Outcome Measurement: The VAS and the LEFS served as the dependent variables in this study. The subject completed these questionnaires at the first test session and after completion of the training protocol. Results: The subject completed a four-week, eight session, verbal and real-time visual feedback training. The subject demonstrated a small improvement in LEFS scores from a pre-test score of 68 points to a post-test score of 73 points. The subject demonstrated an improvement in VAS scores from 21 millimeters (mm) to 6 mm. Conclusion: The subject’s pre- and post- training VAS scores exceeded the 14 mm minimal clinically important difference (MCID) which is important for determining improvement with PFP. However, although the subject experienced an increase in their LEFS score, this change was below the threshold of the MCID. The results from this case study design support the use of verbal and real-time visual feedback to improve the short-term perceived symptoms from PFP in recreational runners. Further research should be conducted to determine if the effects of this type of training protocol promote long-term relief of PFP, or if the need for “retraining” is necessary. Additionally, including dependent variables that actually measure hip and knee kinematics before and after this type of training may be of interest. Key words: Patellofemoral pain, lower extremity functional scale, visual analog scale, augmented feedbac

Grey matter volume correlates with virtual water maze task performance in boys with androgen excess

Major questions remain about the specific role of testosterone in human spatial navigation. We tested 10 boys (mean age 11.65 years) with an extremely rare disorder of androgen excess (Familial Male Precocious Puberty, FMPP) and 40 healthy boys (mean age 12.81 years) on a virtual version of the Morris Water Maze task. In addition, anatomical magnetic resonance images were collected for all patients and a subsample of the controls (n=21) after task completion. Behaviourally, no significant differences were found between both groups. However, in the MRI analyses, grey matter volume (GMV) was correlated with performance using voxel-based morphometry (VBM). Group differences in correlations of performance with GMV were apparent in medial regions of the prefrontal cortex as well as the middle occipital gyrus and the cuneus. By comparison, similar correlations for both groups were found in the inferior parietal lobule. These data provide novel insight into the relation between testosterone and brain development and suggest that morphological differences in a spatial navigation network covary with performance in spatial ability. Published by Elsevier Ltd on behalf of IBRO

Integrated assessment of oyster reef ecosystem services: Quantifying Denitrification Rates and Nutrient Fluxes

Measurements of nutrient exchange were made in restored oyster reefs and creek sediments in 2014 and 2015 in Harris Creek, Maryland, USA. Rates of ammonium, nitrate and di-nitrogen fluxes were much higher in reef environments than in sediments, and rates of oxygen uptake reflected high inputs of biodeposits. The rate of denitrification was related to oyster biomass and oyster numbers. The shallow nature of the restoration allows light to reach the bottom and benthic microalgal photosynthesis affects the net nutrient exchange with the bottom. After several years, oyster restoration has increased denitrification in Harris Creek, though observations in mature upper Choptank restored reefs are higher. The trajectory of increase of the nutrient ecosystem services is positive and will be followed over time

Implications of Qudit Superselection rules for the Theory of Decoherence-free Subsystems

The use of d-state systems, or qudits, in quantum information processing is discussed. Three-state and higher dimensional quantum systems are known to have very different properties from two-state systems, i.e., qubits. In particular there exist qudit states which are not equivalent under local unitary transformations unless a selection rule is violated. This observation is shown to be an important factor in the theory of decoherence-free, or noiseless, subsystems. Experimentally observable consequences and methods for distinguishing these states are also provided, including the explicit construction of new decoherence-free or noiseless subsystems from qutrits. Implications for simulating quantum systems with quantum systems are also discussed.Comment: 13 pages, 1 figures, Version 2: Typos corrected, references fixed and new ones added, also includes referees suggested changes and a new exampl

Greenfield HSA Service Learning Project

Albert M. Greenfield Elementary School is a kindergarten to eighth-grade public school in Philadelphia, Pennsylvania. The Greenfield Home and School Association (HSA) is a parent organization whose efforts to support the school include sending weekly informational newsletters and by fundraising for school improvements. The HSA recently has become concerned that Greenfield teachers may be struggling with burnout originating from increasing demands placed upon them by pandemic-related stresses. The HSA asked for help in identifying and evaluating positive psychology interventions that could be used at Greenfield to reduce teacher burnout and increase teacher well-being. Three students from the Master of Positive Psychology (MAPP) program at the University of Pennsylvania addressed the concerns of the HSA by developing well-being interventions that might be adopted by the HSA as part of their programming over the next year. The interventions proposed by the MAPP students included administering a teacher burnout and well-being survey, adopting a mission statement that incorporated a well-being purpose for the organization, developing micro-interventions that could be easily and quickly used by teachers, improving the teachers’ lounge for greater well-being, and hosting a positive psychology retreat for teachers. Each of these interventions, described in detail in this report, was intended to use the principles of positive psychology to alleviate and prevent burnout in teachers and help build and enhance the resilience of the school community post-pandemic

An updated model for estimating the TMDL-related benefits of oyster reef restoration Harris Creek, Maryland, USA

In 2014, a user-friendly, web-accessible model was developed that allowed restoration practitioners and resource managers to easily estimate the TMDLrelated benefits of oyster reef (Crassostrea virginica) restoration per unit area, run restoration scenarios in Harris Creek, MD to optimize restoration planning and implementation, and calculate the benefits of the chosen plan. The model was rooted in scientifically defensible data and was readily transferrable to systems throughout the Chesapeake Bay and Eastern Shore. The model operated in five vertically well-mixed boxes along the main axis of the creek. Exchanges among creeks were computed using a tidal prism approach and were compared to exchanges provided from a high resolution 3D hydrodynamic model. Watershed inputs for the model were obtained for the Harris Creek sub-watershed from the Phase V Chesapeake Bay Program Watershed Model. The base model simulated daily concentrations over an annual cycle of chlorophyll-a, dissolved inorganic nitrogen (N) and phosphorus (P), dissolved oxygen, total suspended solids, the biomass of benthic microalgae, and the water column and sediment pools of labile organic carbon (C) and associated N and P. Water quality data for model forcing and calibration were obtained from the Chesapeake Bay Program, the Choptank Riverkeeper, the University of Maryland Center for Environmental Science, and the Maryland Department of Natural Resources. An oyster sub-model was coupled to this base model to compute the volume of water filtered, removal of phytoplankton, suspended solids, and associated nutrients via filtration, recycling of nutrients and consumption of oxygen by oyster respiration, production of feces, N and P accumulation in oyster tissues and shell, oyster-enhanced denitrification, and N and P burial associated with restored reefs. The completed model was served online and operated through a web browser, enabling users to conduct scenario analysis by entering box-specific values for acres restored, restored oyster density, and restored oyster size, as well as the economic value of associated N and P removal. The updated model incorporates all aspects of the previous model but replaces oyster related data collected outside Harris Creek with site-specific data, and now includes restored oyster populations and water quality data through 2016. It also incorporates the impacts of two common, reef-associated filter feeding organisms: the hooked mussel Ischadium recurvum and the sea squirt Molgula manhattensis. Additional data collected in Harris Creek and incorporated into the model include: biomass of benthic microalgae, biogeochemical fluxes in relation to oyster biomass, and the biomass density and distribution of the dominant non-oyster reef filter feeders (I. recurvum, and M. manhattensis). The revised model incorporates an improved estimate of annual oyster growth, uses an improved method for estimating N and P sequestered in tissues and shells, and accounts for the prerestoration oyster population in Harris Creek. The model also incorporates data on the filtration capacity of I. recurvum and M. manhattensis in relation to C. virginica collected as part of a previous study (not in Harris Creek) by Kellogg and Newell (unpublished data)

Low-Frequency Radio Transients in the Galactic Center

We report the detection of a new radio transient source, GCRT J1746-2757, located only 1.1 degrees north of the Galactic center. Consistent with other radio transients toward the Galactic center, this source brightened and faded on a time scale of a few months. No X-ray counterpart was detected. We also report new 0.33 GHz measurements of the radio counterpart to the X-ray transient source, XTE J1748-288, previously detected and monitored at higher radio frequencies. We show that the spectrum of XTE J1748-288 steepened considerably during a period of a few months after its peak. We also discuss the need for a more efficient means of finding additional radio transients

Comparison of methods for determining biogeochemical fluxes from a restored oyster reef

Oyster reef restoration can significantly increase benthic denitrification rates. Methods applied to measure nutrient fluxes and denitrification from oyster reefs in previous studies include incubations of sediment cores collected adjacent to oyster clumps, benthic chambers filled with intact reef segments that have undergone in situ equilibration and ex situ incubation, and cores with single oysters. However, fluxes of nutrients vary by orders of magnitude among oyster reefs and methods. This study compares two methods of measuring nutrient and metabolic fluxes on restored oyster reefs: incubations including intact segments of oyster reef and incubations containing oyster clumps without underlying sediments. Fluxes of oxygen (O-2), dissolved inorganic carbon (DIC), ammonium (NH4+), combined nitrate and nitrite (NO2/3-), di-nitrogen (N-2), and soluble reactive phosphorus (SRP) were determined in June and August in Harris Creek, a tributary of the Chesapeake Bay, Maryland, USA. Regression of fluxes measured from clumps alone against those measured from intact reef segments showed significant positive relationships for O-2, DIC, NH4+, and SRP (R-2 = 0.920, 0.61, 0.26, and 0.52, respectively). Regression of clump fluxes against the oyster tissue biomass indicates significant positive relationships for O-2 and NH4+, marginally significant and positive relationships for DIC and N-2, and no significant relationship for NO2/3- or SRP. Although these results demonstrate that the incubation of oyster clumps without underlying sediments does not accurately represent biogeochemical fluxes measured from the whole oyster and sediment community, this work supports the need to understand the balance between the metabolism of oysters and local sediments to correctly estimate biogeochemical rates

Comparison of unitary transforms

We analyze the problem of comparing unitary transformations. The task is to decide, with minimal resources and maximal reliability, whether two given unitary transformations are identical or different. It is possible to make such comparisons without obtaining any information about the individual transformations. Different comparison strategies are presented and compared with respect to their efficiency. With an interferometric setup, it is possible to compare two unitary transforms using only one test particle. Another strategy makes use of a two-particle singlet state. This strategy is more efficient than using a non-entangled two-particle test state, thus demonstrating the benefit of entanglement. Generalisations to higher dimensional transforms and to more than two transformations are made.Comment: 11 pages, 4 figures, revtex4, submitted to J. Phys.