The Nature of Sacrifice:A Biography of Charles Russell Lowell, Jr.

Gentleman soldier The real story behind the eulogized Yankee The South lost its cause and its men; a victorious North lost only men. For some Northerners however, not all losses were equal. Some deaths left larger legacies, usually by virtue of high birth, membership in families ...

FARM-LEVEL RESPONSE TO AGRICULTURAL EFFLUENT CONTROL STRATEGIES: THE CASE OF THE WILLAMETTE VALLEY

This article examines economic incentives and other mechanisms to offset non-point source pollution from agriculture. A biophysical simulator to estimate technical relationships is linked to linear programming models for representative farms in the Willamette Valley of Oregon. The models are then optimized for profit maximization under alternative non-point pollution control policies. The results indicate that site-specific resource conditions and production possibilities greatly influence policy effectiveness and the cost of achieving pollution abatement. Nevertheless, some abatement is possible on all farms for relatively little cost.Environmental Economics and Policy,

Evidence for High-Frequency QPOs with a 3:2 Frequency Ratio from a 5000 Solar Mass Black Hole

Following the discovery of 3:2 resonance quasi-periodic oscillations (QPOs) in M82X-1 (Pasham et al. 2014), we have constructed power density spectra (PDS) of all 15 (sufficiently long) {\it XMM-Newton} observations of the ultraluminous X-ray source NGC1313X-1 ($L_{X}$ $\approx$ 2$\times$10$^{40}$ erg/sec). We detect a strong QPO at a frequency of 0.29$\pm$0.01 Hz in data obtained on 2012 December 16. Subsequent searching of all the remaining observations for a 3:2/2:3 frequency pair revealed a feature at 0.46$\pm$0.02 Hz on 2003 Dec 13 (frequency ratio of 1.59$\pm$0.09). The global significance of the 0.29 Hz feature considering all frequencies between 0.1 and 4 Hz is $>$ 3.5 $\sigma$. The significance of the 0.46$\pm$0.02 Hz QPO is $>$ 3.5$\sigma$ for a search at 2/3 and 3/2 of 0.29 Hz. We also detect lower frequency QPOs (32.9$\pm$2.6 and 79.7$\pm$1.2 mHz). All the QPOs are super-imposed on a continuum consisting of flat-topped, band-limited noise, breaking into a power-law at a frequency of 16$\pm$3 mHz and white noise at $\gtrsim$ 0.1 Hz. NGC1313X-1's PDS is analogous to stellar-mass black holes' (StMBHs) PDS in the so-called steep power-law state, but with the respective frequencies (both QPOs and break frequencies) scaled down by a factor of $\sim$ 1000. Using the inverse mass-to-high-frequency QPO scaling of StMBHs, we estimate NGC1313X-1's black hole mass to be 5000$\pm$1300 $M_{\odot}$, consistent with an inference from the scaling of the break frequency. However, the implied Eddington ratio, L$_{Edd}$ $>$ 0.03$\pm$0.01, is significantly lower compared to StMBHs in the steep power-law state (L$_{Edd}$ $\gtrsim$ 0.2).Comment: Published in ApJ Letter

Sulphur-isotope compositions of pig tissues from a controlled feeding study

Sulphur-isotope determinations are becoming increasingly useful for palaeodietary reconstruction, but knowledge of isotopic discrimination between diet and various tissues remains inadequate. In this study, we explore the sensitivity of δ34Stissue values to changes in δ34Sdiet values, sulphur isotopic discrimination between diet and consumer, and the potential impact of terrestrial vs. marine protein consumption on these discrimination offsets. We present new δ34S values of bone collagen, muscle, liver, hair, milk and faeces from ten mature sows, ten piglets and fifteen adolescent pigs from a controlled feeding study. The δ34Stissue values were found to co-vary with the δ34Sdiet values, the δ34Stissue – δ34Sdiet isotopic offsets (Δ34Stissue-diet) are small but consistent, and dietary protein source does not systematically alter the Δ34Stissue-diet isotopic discrimination. The outcomes of this study are of particular relevance to questions that are difficult to resolve using carbon and nitrogen stable isotopes alone, and will also be useful in regions where terrestrial, freshwater, and marine resources could have all potentially contributed to human diet

The effects of high impact learning experiences on student engagement

AbstractStudent engagement includes skills engagement, participation engagement, emotional engagement, and performance engagement. Handlesman et al., (2005) created a questionnaire (SCEQ) that measures these forms of engagement. The purpose of this study was to determine the extent to which each form is promoted by different learning experiences. One hundred an twenty-seven students involved in (a) undergraduate research, (b) learning communities, (c) internships, or (d) service learning completed the SCEQ. The results indicated that undergraduate research and internships promoted greater student engagement. Key factors contributing to engagement included perceived career relevance, faculty/student collaboration and the focus and intensity of the learning experience

Using computational fluid dynamics (CFD) to design and characterize a microfluidic bioreactor for rapid release of culture-derived platelets

Platelet transfusions are entirely dependent on human volunteer donors, and these methods are limited by platelet storage at room temperature, a 5-day platelet shelf life, and differences in donor/recipient immunology. Much progress has been made in generating large numbers of culture-derived megakaryocytes (Mks, the precursor cells to platelets). However, much remains unknown about what initiates and regulates platelet formation, so stimulating a high percentage of Mks to undergo terminal maturation and platelet release in vitro remains a major challenge. Methods of in vitro platelet production have typically yielded less than 10 platelets/Mk, compared to \u3e1,000 in vivo. In vivo, platelets are formed when bone marrow Mks extend long, cytoplasmic projections, called proplatelets (proPLTs), into the sinusoid where shear forces accelerate proPLT elongation and release platelets into circulation. Recent studies have demonstrated the utility of shear forces to enhance platelet release from cultured Mks in vitro. We are exploring the production of platelet-like particles (PLPs) within a microfluidic bioreactor that utilizes shear forces on Mks to generate proPLTs and PLPs. Microfluidic devices have emerged as a valuable tool for cell culture studies. Advantages include low input cell requirements, the ability to screen multiple conditions in parallel, compatibility with time-lapse imaging, and tight control of microenvironment conditions. In addition, device fabrication is straightforward and inexpensive using soft photolithography. In this study, we performed a computational fluid dynamics (CFD) analysis of several published platelet microbioreactor systems, and used the results to develop a new bioreactor system. Through CFD simulations and microfluidic device fabrication, a design – test – build methodology was used to develop a dual-flow microfluidic bioreactor system with uniform shear stress at levels similar to those found in the bone marrow niche. Experimental studies were conducted to validate the simulations in terms of streamline profiles and flow patterns with and without cell capture. Furthermore, the design of the bioreactor allows for a wide physiological shear rate range, and fits within the stage of a fluorescent microscope housed in an incubator that allows for real-time analysis of proPLT formation and PLP release. The videos and images captured within our system show that the new bioreactor not only promotes the prototypical proPLT formation process with beadson-a-string morphology, but also supports rapid release of individual PLPs – which has been observed in vivo, but not previously reported for platelet bioreactors. In addition, we demonstrate that step increases in the shear forces within the microbioreactor system can be used to enhance proPLT and PLP formation. Bioreactor-derived PLPs exhibit functional activity, as evidenced by CD41a and CD42b surface marker expression, CD62P translocation from granules to the surface in response to thrombin agonist activation, and morphological/ cytoskeletal changes upon binding to fibrinogen – before and after activation. The system can be further scaled, for example, through parallelization of reactors

Spectral State Transitions of the Ultraluminous X-ray Source IC 342 X-1

We observed the Ultraluminous X-ray Source IC 342 X-1 simultaneously in X-ray and radio with Chandra and the JVLA to investigate previously reported unresolved radio emission coincident with the ULX. The Chandra data reveal a spectrum that is much softer than observed previously and is well modelled by a thermal accretion disc spectrum. No significant radio emission above the rms noise level was observed within the region of the ULX, consistent with the interpretation as a thermal state though other states cannot be entirely ruled out with the current data. We estimate the mass of the black hole using the modelled inner disc temperature to be $30~\mathrm{M_{\odot}} \lesssim M\sqrt{\mathrm{cos}i}\lesssim200~\mathrm{M_{\odot}}$ based on a Shakura-Sunyaev disc model. Through a study of the hardness and high-energy curvature of available X-ray observations, we find that the accretion state of X-1 is not determined by luminosity alone.Comment: 10 pages, 5 Figures. MNRAS: Accepted 2014 July 2