A large scale height galactic component of the diffuse 2-60 keV background

The diffuse 2-60 keV X-ray background has a galactic component clearly detectable by its strong variation with both galactic latitude and longitude. This galactic component is typically 10 percent of the extragalactic background toward the galactic center, half that strong toward the anticenter, and extrapolated to a few percent of the extragalactic background toward the galactic poles. It is acceptably modeled by a finite radius emission disk with a scale height of several kiloparsecs. The averaged galactic spectrum is best fitted by a thermal spectrum of kT about 9 keV, a spectrum much softer than the about 40 keV spectrum of the extragalactic component. The most likely source of this emission is low luminosity stars with large scale heights such as subdwarfs. Inverse Compton emission from GeV electrons on the microwave background contributes only a fraction of the galactic component unless the local cosmic ray electron spectrum and intensity are atypical

Key Components of Immigration Reform: An Analysis of the Economic Effects of Creating a Pathway to Legal Status, Expanding High-Skilled Visas, & Reforming Lesser-Skilled Visas

As the policy debate continues in Washington, DC and throughout the nation, this study shows the state- and national-level economic effects of key components of immigration policy reform. This report evaluates the economic implications of the Path to Legal Status, high-skilled (H-1B) visa expansion, and changes in lesser-skilled visa programs (H-2A, H-2B, and W-1 Visas). The authors use a REMI PI+ model of all 50 states and the District of Columbia to show the macroeconomic effects of the policy changes over the period of 2014 to 2045. PI+ is a multiregional macroeconomic model that has been used in thousands of national and regional economic studies, including studies of other elements of immigration reforms in the United States. Thiis report details the macroeconomic effects of each policy on the national and state level. Key summary macroeconomic indicators include employment, gross domestic (state) product, and personal income. It also provides employment effects by industry for the United States, and a complete set of state-level fact sheets which present results for each policy and all 50 states and the District of Columbia

Al\u27Riq: The Arab Tambourine

The riq (plural: riqat) is a small tambourine measuring 22cm - 25cm in diameter and approximately 5cm - 7cm in depth. The instrument consists of ten pairs of brass, bronze or copper jingles inserted equidistantly around the frame in two rows, held in place by metal pins. It is traditionally fitted with a natural skin head, usually fish, however modern riqat often utilize a variety of tuning systems, making the use of synthetic skins possible. Several names for the instrument exist historically. Historical variations of the riq appear frequently in Islamic art. The riq is performed with exceptional dynamic contrast with unique ornamentations. The instrument is a mainstay in the takht, firqah, and Firqat Al-Musiqa Al-`Arabiyyah ensembles, as well as a number of other traditional ensembles. The performer of the instrument often assumes a leadership responsibility in Arab ensembles. The traditional performance context of the riq remains largely in the Arab world, with few exceptions in the West. With reduced opportunities to perform the riq in its traditional context, solo and percussion ensemble repertoire for the riq are increasingly popular, composed mainly in Western styles with Arab subtleties

Evidence of hydrological control of Sr behavior in stream water (Strengbach catchment, Vosges mountains, France)

Strontium and particularly 87Sr/86Sr ratios in stream water have often been used to calculate weathering rates in catchments. Nevertheless, in the literature, discharge variation effects on the geochemical behavior of Sr are often omitted or considered as negligible. A regular survey of both Sr concentrations and Sr isotope ratios of the Strengbach stream water draining a granite (Vosges mountains, France) has been performed during one year. The results indicate that during low water flow periods, waters contain lower Sr concentrations and less radiogenic Sr isotope ratios (Sr=11.6 ppb and 87Sr/86Sr=0.7246 as an average, respectively) than during high water flow periods (Sr= 13 ppb and 87Sr/86Sr=0.7252 as an average, respectively). This is contrary to expected dilution processes by meteoric waters which have comparatively lower Sr isotopic ratios and lower Sr concentrations. Furthermore, 87Sr/86Sr ratios in stream water behave in 3 different ways depending on moisture and on hydrological conditions prevailing in the catchment. During low water flow periods (discharge < 9 l/s), a positive linear relationship exists between Sr isotope ratio and discharge, indicating the influence of radiogenic waters draining the saturated area during storm events. During high water flow conditions, rising discharges are characterized by significantly less radiogenic waters than the recession stages of discharge. This suggests a large contribution of radiogenic waters draining the deep layers of the hillslopes during the recession stages, particularly those from the more radiogenic north-facing slopes. These results allow one to confirm the negligible instantaneous incidence of rainwater on stream water chemistry during flood events, as well as the existence in the catchment of distinct contributive areas and reservoirs. The influence of these areas or reservoirs on the fluctuations of Sr concentrations and on Sr isotopic variations in stream water depends on both moisture and hydrological conditions. Hence, on a same bedrock type, 87Sr/86Sr ratios in surface waters can be related to flow rate. Consequently, discharge variations must be considered as a pre-requisite when using Sr isotopes for calculating weathering rates in catchments, particularly to define the range of variations of the end-members

ECOSYSTEM RESPONSES TO FUEL REDUCTION TREATMENTS IN STANDS KILLED BY SOUTHERN PINE BEETLE

Heavy fuel loads were created by multiple southern pine beetle (Dendroctonus frontalis Ehrh.) outbreaks throughout the southern Piedmont between 1999 and 2002. Prescribed burning and mechanical mastication are proposed to reduce fuel loading in beetle-killed pine (Pinus L. spp.) stands in the upper South Carolina Piedmont, but their ecological impacts are unknown. Prescribed burning reduced fuelbed continuity by consuming litter (Oi) and fine (1- and 10-hr timelag size classes) woody fuels immediately after the treatment. Duff (Oe + Oa) layer thickness also decreased and mineral soil was exposed in some areas. Mastication resulted in a thick, continuous layer of shredded and ground live and dead standing vegetation and dead and down woody debris being deposited on the forest floor. Burning caused immediate reductions in exchangeable Ca, P, and Al, but significant differences did not persist into Yr 2. Mastication reduced P and Al and increased K, but again significant differences were transient. Neither VAM nor ECM soil inoculum potential (SIP) observed from soil bioassays in Yr 1 were significantly different among treatments, but both were highly variable within treated stands. ECM SIP was positively associated with NH4+-N concentration, peak burning temperature, and duration of heating above 50°C when measured at the soil-duff (Oe + Oa) interface. Conversely, VAM SIP was negatively associated with NH4+-N concentration, peak burning temperature, and heating duration. Best-subset regression additionally revealed that post-treatment SIP was associated with pre-treatment vegetation assemblages. Oak ((Quercus L. spp.) sprouts grew slower than other hardwoods competitors, but comprised a substantial portion of the advance regeneration pool in burned stands. The mastication treatment apparently damaged basal buds of advance regeneration and sprouting was inhibited. Overall, large advance hardwood regeneration was less abundant and there were proportionately fewer oak than other hardwood stems after mastication when compared to prescribed burning. By Yr 2 post-treatment, large advance oak regeneration was sufficient to reasonably ensure that oak would be a significant component of burned stands at crown closure but insufficient in masticated stands. First-year survival of planted loblolly pine ((P. taeda L.) seedlings was highest in masticated stands when compared to the other treatments and likely related to reduced growth of woody and herbaceous competition. Non-metric multidimensional scaling ordination revealed that the understory plant communities in burned and masticated stands were similar to one another, but distinct from the control. Plants associated with dry, open conditions were encouraged by the active treatments whereas there was a higher incidence of plants associated with shaded and moist conditions in the control. Results of this study will assist forest managers in evaluating treatment options for different silvicultural objectives in beetle-killed southern pine stands

Computers and the Field Research Station

The National Science Foundation recently sponsored a workshop focusing on data management at biological field stations, with an emphasis on small and medium-sized stations. These stations, often linked to Long Term Ecological Research sites and university field stations, face increasing demands for sophisticated data management systems. The workshop explored topics such as data cataloging, administration, software options, and mechanisms for sharing data across sites. A key point of discussion was the growing interest in automated data handling systems, driven by the need for improved data quality control, regional analysis, and hypothesis testing. While the use of computers is not always essential for smaller data sets, the evolving requirements for high-quality research data underscore the importance of selecting appropriate software and hardware. The paper stresses that determining data management needs should precede decisions about hardware and software. It also highlights the role of off-the-shelf software solutions and microcomputers, which offer affordable and user-friendly tools for data analysis and documentation. Furthermore, the importance of data documentation, which ensures transparency about data collection conditions, was emphasized. Finally, the paper addresses challenges in inter-site data exchange and the complexities of establishing effective computer networks, advocating for careful planning in the application of computer technology to field station operations

Ecosystem responses to acid precipitation—Isle Royale National Park

An overview of the problem of acid precipitation and its effects on Isle Royale National Park

A Crisis of Space: Identity, Subjectivity, and Materiality in Postmodern American Fiction

The material world as it is represented in postmodern American novels accounts for subjectivity and identity in ways that remain critically unexplored. This dissertation, therefore, examines representations of space, the subject, and materiality in three postmodern American novels: Housekeeping by Marilynne Robinson, Beloved by Toni Morrison, and The Road by Cormac McCarthy. For the protagonists in these novels, finding refuge in a material world attenuates the power exerted in socially constructed spaces. In this way, spatial relationships empower the individual character in a struggle against the discursive representations and socio-political forces that seek to define, limit, and determine identity performance as a means for maintaining social and political domination. Although these three novels contend with different subjects and time periods, representations of transience and spatial movement unify them, and in each novel transience is the means by which the subject disrupts discourses of power. Analyses of these novels indicate contemporary changes in how subjects are produced, and they also indicate how interpretations of subjectivity and identity as concepts have changed over the previous forty years

Bilateral Anterior Ischemic Optic Neuropathy During Treatment with Pegylated Interferon and Ribavirin

Hepatitis C virus (HCV) is a blood-borne pathogen that often results in chronic liver infection leaving patients at risk for cirrhosis, liver decompensation and hepatocellular carcinoma. The goal of therapy is to eliminate the virus in order to minimize morbidity and mortality from HCV infection. Traditional treatment has utilized a combination of pegylated-interferon (IFN) and ribavirin that often causes both systemic and ocular side effects. The most common ocular side effects are retinal hemorrhages and cotton wool spots, although in rare circumstances more significant ophthalmic adverse events have been attributed to IFN therapy. Here we discuss a case of bilateral anterior ischemic optic neuropathy (AION) that occurred during treatment with IFN and ribavirin for HCV genotype 1. We review the proposed pathogenesis of ocular side effects associated with this regimen, as well as the pathogenesis and risk factors associated with AION itself. Finally, we will offer clinical recommendations for screening for more than retinopathy should a patient present with ophthalmic complications

A multiple case study of high school perspectives making music with code in Sonic Pi

The purpose of this study was to investigate perceptions of high school students who made music with code in Sonic Pi. This qualitative multiple case study focused on individuals in an extracurricular club at a public charter high school who volunteered to participate on-site and remotely asynchronously via Canvas learning management system. This study was guided by five research questions, including: (1) What musical ideas, if any, do participants report learning or demonstrate through making music with code in Sonic Pi? (2) How does making music with code impact participants’ perceptions of their music making? (3) How does making music with code impact participants’ perceptions of their ability to learn to make music? (4) How does making music with code impact participants’ interest in music courses? (5) How does making music with code impact participants’ interest in computer science courses? Participants completed research study materials, including a series of tutorials for Sonic Pi. Data included answers to questionnaires and surveys, multimedia artifacts including the source code and exported audio of participants’ music making, and interviews of participants that were codified and analyzed in two cycles, utilizing descriptive coding, values coding, and longitudinal coding. Participants’ code and multimedia artifacts revealed a close alignment to the four properties of sound, including: pitch, duration, intensity/amplitude, and timbre. Participants’ artifacts revealed themes and demonstrated ideas extending beyond the four properties, including: form, non-traditional music notation, and randomization. Participants all agreed their coded artifacts are music. Additionally, participants’ varied responses about musicianship and composers suggests that making music is something anyone can engage in, regardless of how one identifies themself. All participants agreed that Sonic Pi is a useful tool for learning and understanding musical concepts and that Western staff notation is not required knowledge for making music. Participants’ interests in music or computer science courses were impacted by their prior experiences in music and/or coding. This study concludes with a discussion of themes based on the findings