Does Efficient Irrigation Technology Lead to Reduced Groundwater Extraction?: Empirical Evidence

Policies that encourage the use of more efficiency irrigation technology are often viewed as effective, politically feasible methods to reduce the consumptive use of water for agricultural production. Despite their widespread use, these policies have not been subject to empirical evaluation. In this article, we evaluate the effect on groundwater extraction of a widespread conversion from traditional center pivot irrigation systems to higher efficiency dropped-nozzle center pivot systems that has occurred in western Kansas. State and national cost-share programs subsidized the conversion. We find that the programs have not had the intended effect; the shift to more efficient irrigation technology has not decreased the amount of water applied to a given crop, and has actually increased groundwater extraction through changing cropping patterns.irrigation efficiency, groundwater management, irrigation technology, Environmental Economics and Policy, Land Economics/Use,

The Impact of Food Away from Home on Adult Diet Quality

Food away from home (FAFH) has been associated with poor diet quality in many studies. It is difficult, however, to measure the effect of FAFH on diet quality since many unobserved factors, such as food preferences and time constraints, influence not just our choice of where to eat but also the nutritional quality of what we eat. Using data from 1994-96 and 2003-04, this study applies fixed-effects estimation to control for such unobservable influences and finds that, for the average adult, FAFH increases daily caloric intake and reduces diet quality. The effects vary depending on which meals are consumed away from home. On average, breakfast away from home decreases the number of servings of whole grains and dairy consumed per 1,000 calories and increases the percent of calories from saturated and solid fat, alcohol, and added sugar (SoFAAS) in a day. Dinner away from home reduces the number of servings of vegetables consumed per 1,000 calories for the average adult. Breakfast and lunch away from home increase calories from saturated fat and SoFAAS on average more among dieters than among nondieters. Some of the overall negative dietary effects decreased between 1994-96 and 2003-04, including those on whole grain, sodium, and vegetable consumption.Food away from home (FAFH), diet quality, 2005 Healthy Eating Index (HEI-2005), fixed-effects, first-difference, Continuing Survey of Food Intakes by Individuals (CSFII), National Health and Nutrition Examination Survey (NHANES), Health Economics and Policy,

Deep H-band Galaxy Counts and Half-light Radii from HST/NICMOS Parallel Observations

We present deep galaxy counts and half-light radii from F160W ($\lambda_c=1.6\mu$) images obtained with NICMOS on HST. Nearly 9 arcmin$^2$ have been imaged with camera 3, with $3\sigma$ depths ranging from H = 24.3 to 25.5 in a 0.6$''$ diameter aperture. The slope of the counts fainter than H~$= 20$ is 0.31, and the integrated surface density to H$\leq 24.75$ is $4 \times 10^5$ galaxies per square degree. The half-light radii of the galaxies declines steeply with apparent magnitude. At H~$=24$ we are limited by both the delivered FWHM and the detection threshold of the images.Comment: 8 pages. Accepted for publication in ApJ Letter

Path deviations outperform approximate stability in heterogeneous congestion games

We consider non-atomic network congestion games with heterogeneous players where the latencies of the paths are subject to some bounded deviations. This model encompasses several well-studied extensions of the classical Wardrop model which incorporate, for example, risk-aversion, altruism or travel time delays. Our main goal is to analyze the worst-case deterioration in social cost of a perturbed Nash flow (i.e., for the perturbed latencies) with respect to an original Nash flow. We show that for homogeneous players perturbed Nash flows coincide with approximate Nash flows and derive tight bounds on their inefficiency. In contrast, we show that for heterogeneous populations this equivalence does not hold. We derive tight bounds on the inefficiency of both perturbed and approximate Nash flows for arbitrary player sensitivity distributions. Intuitively, our results suggest that the negative impact of path deviations (e.g., caused by risk-averse behavior or latency perturbations) is less severe than approximate stability (e.g., caused by limited responsiveness or bounded rationality). We also obtain a tight bound on the inefficiency of perturbed Nash flows for matroid congestion games and homogeneous populations if the path deviations can be decomposed into edge deviations. In particular, this provides a tight bound on the Price of Risk-Aversion for matroid congestion games

Lymphoid priming in human bone marrow begins before expression of CD10 with upregulation of L-selectin.

Expression of the cell-surface antigen CD10 has long been used to define the lymphoid commitment of human cells. Here we report a unique lymphoid-primed population in human bone marrow that was generated from hematopoietic stem cells (HSCs) before onset of the expression of CD10 and commitment to the B cell lineage. We identified this subset by high expression of the homing molecule L-selectin (CD62L). CD10(-)CD62L(hi) progenitors had full lymphoid and monocytic potential but lacked erythroid potential. Gene-expression profiling placed the CD10(-)CD62L(hi) population at an intermediate stage of differentiation between HSCs and lineage-negative (Lin(-)) CD34(+)CD10(+) progenitors. CD62L was expressed on immature thymocytes, and its ligands were expressed at the cortico-medullary junction of the thymus, which suggested a possible role for this molecule in homing to the thymus. Our studies identify the earliest stage of lymphoid priming in human bone marrow

Inhibition of interleukin-1 signaling enhances elimination of tyrosine kinase inhibitor treated CML stem cells

Treatment of chronic myelogenous leukemia (CML) with BCR-ABL tyrosine kinase inhibitors (TKI) fails to eliminate leukemia stem cells (LSC). Patients remain at risk for relapse, and additional approaches to deplete CML LSC are needed to enhance the possibility of discontinuing TKI treatment. We have previously reported that expression of the pivotal proinflammatory cytokine interleukin-1 (IL-1) is increased in CML bone marrow (BM). We show here that CML LSC demonstrated increased expression of the IL-1 receptors, IL-1RAP and IL- 1R1, and enhanced sensitivity to IL-1-induced NF-KB signaling compared to normal stem cells. Treatment with recombinant IL-1 receptor antagonist (IL-1RA) inhibited IL-1 signaling in CML LSC and inhibited growth of CML LSC. Importantly, the combination of IL-1RA with TKI resulted in significantly greater inhibition of CML LSC compared with TKI alone. Our studies also suggest that IL-1 signaling contributes to overexpression of inflammatory mediators in CML LSC, suggesting that blocking IL-1 signaling could modulate the inflammatory milieu. We conclude that IL-1 signaling contributes to maintenance of CML LSC following TKI treatment, and that IL- 1 blockade with IL-1RA enhances elimination of TKI-treated CML LSC. These results provide a strong rationale for further exploration of anti-IL-1 strategies to enhance LSC elimination in CML