584 research outputs found

    Reflections on the Ostroms’ Contributions to the Social Sciences

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    Keynote memorial address and panel discussion of the life and work of Elinor Ostro

    Digging Deeper into Hardin\u27s Pasture: The Complex Institutional Structure of The Tragedy of the Commons

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    The institutional and ecological structure of Hardin’s “tragedy of the commons” appears deceptively simple: the open-access pasture eventually will be overexploited and degraded unless (i) it is privatized, (ii) the government regulates access and use, or (iii) the users themselves impose a common-property regime to regulate their own access and use. In this paper, we argue that the institutional structure of the “Herder Problem” (as it is known to game theorists) is far more complicated than it is usually portrayed. Specifically, it is not just about the pasture. It is equally about the grass that grows on the pasture and the cattle that consume the grass. Even Elinor Ostrom — a scholar known for embracing complexity — presented an overly simplistic portrayal of Hardin’s open-access pasture when she described its governance system as a null set of institutions. A more careful assessment of the situation, employing Ostrom’s Social-Ecological System (SES) framework, broadens the focus from the res communes omnium pasture to incorporate the res nullius grass that grows upon it and the res private cattle grazing there. The “tragedy” arises from the combination and interactions of the resources and their governing institutions, not just from the absence of property in the pasture. If the grass was not subject to appropriation, the cattle were not privately owned, or if property- and contract-enforcement institutions supporting market exchange were absent, the “tragedy of the commons” probably would not arise regardless of the pasture’s open-access status

    Digging Deeper into Hardin\u27s Pasture: The Complex Institutional Structure of The Tragedy of the Commons

    Get PDF
    The institutional and ecological structure of Hardin’s “tragedy of the commons” appears deceptively simple: the open-access pasture eventually will be overexploited and degraded unless (i) it is privatized, (ii) the government regulates access and use, or (iii) the users themselves impose a common-property regime to regulate their own access and use. In this paper, we argue that the institutional structure of the “Herder Problem” (as it is known to game theorists) is far more complicated than it is usually portrayed. Specifically, it is not just about the pasture. It is equally about the grass that grows on the pasture and the cattle that consume the grass. Even Elinor Ostrom — a scholar known for embracing complexity — presented an overly simplistic portrayal of Hardin’s open-access pasture when she described its governance system as a null set of institutions. A more careful assessment of the situation, employing Ostrom’s Social-Ecological System (SES) framework, broadens the focus from the res communes omnium pasture to incorporate the res nullius grass that grows upon it and the res private cattle grazing there. The “tragedy” arises from the combination and interactions of the resources and their governing institutions, not just from the absence of property in the pasture. If the grass was not subject to appropriation, the cattle were not privately owned, or if property- and contract-enforcement institutions supporting market exchange were absent, the “tragedy of the commons” probably would not arise regardless of the pasture’s open-access status

    First-Year Spectroscopy for the SDSS-II Supernova Survey

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    This paper presents spectroscopy of supernovae discovered in the first season of the Sloan Digital Sky Survey-II Supernova Survey. This program searches for and measures multi-band light curves of supernovae in the redshift range z = 0.05 - 0.4, complementing existing surveys at lower and higher redshifts. Our goal is to better characterize the supernova population, with a particular focus on SNe Ia, improving their utility as cosmological distance indicators and as probes of dark energy. Our supernova spectroscopy program features rapid-response observations using telescopes of a range of apertures, and provides confirmation of the supernova and host-galaxy types as well as precise redshifts. We describe here the target identification and prioritization, data reduction, redshift measurement, and classification of 129 SNe Ia, 16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first season. We also describe our efforts to measure and remove the substantial host galaxy contamination existing in the majority of our SN spectra.Comment: Accepted for publication in The Astronomical Journal(47pages, 9 figures

    Targeting HOX transcription factors in prostate cancer

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    YesBackground: The HOX genes are a family of transcription factors that help to determine cell and tissue identity during early development, and which are also over-expressed in a number of malignancies where they have been shown to promote cell proliferation and survival. The purpose of this study was to evaluate the expression of HOX genes in prostate cancer and to establish whether prostate cancer cells are sensitive to killing by HXR9, an inhibitor of HOX function. Methods: HOX function was inhibited using the HXR9 peptide. HOX gene expression was assessed by RNA extraction from cells or tissues followed by quantitative PCR, and siRNA was used to block the expression of the HOX target gene, cFos. In vivo modelling involved a mouse flank tumour induced by inoculation with LNCaP cells. Results: In this study we show that the expression of HOX genes in prostate tumours is greatly increased with respect to normal prostate tissue. Targeting the interaction between HOX proteins and their PBX cofactor induces apoptosis in the prostate cancer derived cell lines PC3, DU145 and LNCaP, through a mechanism that involves a rapid increase in the expression of cFos, an oncogenic transcription factor. Furthermore, disrupting HOX/PBX binding using the HXR9 antagonist blocks the growth of LNCaP tumours in a xenograft model over an extended period. Conclusion: Many HOX genes are highly over-expressed in prostate cancer, and prostate cancer cells are sensitive to killing by HXR9 both in vitro and in vivo. The HOX genes are therefore a potential therapeutic target in prostate cancer.The authors gratefully acknowledge the support of the Prostate Project charity (UK)

    The Neutron star Interior Composition Explorer (NICER): design and development

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    Nondestructive Evaluation of Standing Trees With a Stress Wave Method

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    The primary objective of this study was to investigate the usefulness of a stress wave technique for evaluating wood strength and stiffness of young-growth western hemlock and Sitka spruce in standing trees. A secondary objective was to determine if the effects of silvicultural practices on wood quality can be identified using this technique. Stress wave measurements were conducted on 168 young-growth western hemlock and Sitka spruce trees. After in situ measurements, a 0.61-m-long bole section in the test span was taken from 56 felled trees to obtain small, clear wood specimens. Stress wave and static bending tests were then performed on these specimens to determine strength and stiffness. Results of this study indicate that in situ stress wave measurements could provide relatively accurate and reliable information that would enable nondestructive evaluation of wood properties in standing trees. The mean values of stress wave speed and dynamic modulus of elasticity for trees agreed with those determined from small, clear wood specimens. Statistical regression analyses revealed good correlations between stress wave properties of trees and static bending properties of small, clear wood specimens obtained from the trees. Regression models showed statistical significance at the 0.01 confidence level. Results of this study also demonstrate that the effect of silvicultural practices on wood properties can be identified with the stress wave properties of trees. This indicates that this nondestructive stress wave technique can be used to track property changes in trees and help determine how forests could be managed to meet desired wood and fiber qualities

    Targeting melanoma growth and viability reveals dualistic functionality of the phosphonothionate analogue of carba cyclic phosphatidic acid

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    <p>Abstract</p> <p>Background</p> <p>Although the incidence of melanoma in the U.S. is rising faster than any other cancer, the FDA-approved chemotherapies lack efficacy for advanced disease, which results in poor overall survival. Lysophosphatidic acid (LPA), autotaxin (ATX), the enzyme that produces LPA, and the LPA receptors represent an emerging group of therapeutic targets in cancer, although it is not known which of these is most effective.</p> <p>Results</p> <p>Herein we demonstrate that thio-ccPA 18:1, a stabilized phosphonothionate analogue of carba cyclic phosphatidic acid, ATX inhibitor and LPA1/3 receptor antagonist, induced a marked reduction in the viability of B16F10 metastatic melanoma cells compared with PBS-treated control by 80-100%. Exogenous LPA 18:1 or D-sn-1-O-oleoyl-2-O-methylglyceryl-3-phosphothioate did not reverse the effect of thio-ccPA 18:1. The reduction in viability mediated by thio-ccPA 18:1 was also observed in A375 and MeWo melanoma cell lines, suggesting that the effects are generalizable. Interestingly, siRNA to LPA3 (siLPA3) but not other LPA receptors recapitulated the effects of thio-ccPA 18:1 on viability, suggesting that inhibition of the LPA3 receptor is an important dualistic function of the compound. In addition, siLPA3 reduced proliferation, plasma membrane integrity and altered morphology of A375 cells. Another experimental compound designed to antagonize the LPA1/3 receptors significantly reduced viability in MeWo cells, which predominantly express the LPA3 receptor.</p> <p>Conclusions</p> <p>Thus the ability of thio-ccPA 18:1 to inhibit the LPA3 receptor and ATX are key to its molecular mechanism, particularly in melanoma cells that predominantly express the LPA3 receptor. These observations necessitate further exploration and exploitation of these targets in melanoma.</p

    Chronotype and Social Jetlag Influence Performance and Injury during Reserve Officers’ Training Corps Physical Training

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    Sleep and circadian rhythms are critically important for optimal physical performance and maintaining health during training. Chronotype and altered sleep may modulate the response to exercise training, especially when performed at specific times/days, which may contribute to musculoskeletal injury. The purpose of this study was to determine if cadet characteristics (chronotype, sleep duration, and social jetlag) were associated with injury incidence and inflammation during physical training. Reserve Officers’ Training Corps (ROTC) cadets (n = 42) completed the Morningness/Eveningness Questionnaire to determine chronotype, and 1-week sleep logs to determine sleep duration and social jetlag. Salivary IL-6 was measured before and after the first and fourth exercise sessions during training. Prospective injury incidence was monitored over 14 weeks of training, and Army Physical Fitness Test scores were recorded at the conclusion. Chronotype, sleep duration, and social jetlag were assessed as independent factors impacting IL-6, injury incidence, and APFT scores using ANOVAs, chi-squared tests, and the t-test where appropriate, with significance accepted at p \u3c 0.05. Evening chronotypes performed worse on the APFT (evening = 103.8 ± 59.8 vs. intermediate = 221.9 ± 40.3 vs. morning = 216.6 ± 43.6; p \u3c 0.05), with no difference in injury incidence. Sleep duration did not significantly impact APFT score or injury incidence. Social jetlag was significantly higher in injured vs. uninjured cadets (2:40 ± 1:03 vs. 1:32 ± 55, p \u3c 0.05). Exercise increased salivary IL-6, with no significant effects of chronotype, sleep duration, or social jetlag. Evening chronotypes and cadets with social jetlag display hampered performance during morning APFT. Social jetlag may be a behavioral biomarker for musculoskeletal injury risk, which requires further investigation
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