Port Arthur Historic Site: A Case Study

Looks at the management of the Port Arthur Historic Site in Australia by the Port Arthur Historic Site Management Authority (PAHSMA), beginning in 1987

Black hole entropy and renormalization

Using a new regulator, we examine 't Hooft's approach for evaluating black hole entropy through a statistical-mechanical counting of states for a scalar field propagating outside the event horizon. We find that this calculation yields precisely the one-loop renormalization of the standard Bekenstein-Hawking formula, S={\Cal A}/(4G). Thus our result provides evidence confirming a suggestion by Susskind and Uglum regarding black hole entropy

Integrated functions among multiple starch synthases determine both amylopectin chain length and branch linkage location in Arabidopsis leaf starch

This study assessed the impact on starch metabolism in Arabidopsis leaves of simultaneously eliminating multiple soluble starch synthases (SS) from among SS1, SS2, and SS3. Double mutant ss1- ss2- or ss1- ss3- lines were generated using confirmed null mutations. These were compared to the wild type, each single mutant, and ss1- ss2- ss3- triple mutant lines grown in standardized environments. Double mutant plants developed similarly to the wild type, although they accumulated less leaf starch in both short-day and long-day diurnal cycles. Despite the reduced levels in the double mutants, lines containing only SS2 and SS4, or SS3 and SS4, are able to produce substantial amounts of starch granules. In both double mutants the residual starch was structurally modified including higher ratios of amylose:amylopectin, altered glucan chain length distribution within amylopectin, abnormal granule morphology, and altered placement of α(1→6) branch linkages relative to the reducing end of each linear chain. The data demonstrate that SS activity affects not only chain elongation but also the net result of branch placement accomplished by the balanced activities of starch branching enzymes and starch debranching enzymes. SS3 was shown partially to overlap in function with SS1 for the generation of short glucan chains within amylopectin. Compensatory functions that, in some instances, allow continued residual starch production in the absence of specific SS classes were identified, probaby accomplished by the granule bound starch synthase GBSS1.ANR Génoplante GPLA0611GEuropean Union-FEDER, Région Nord Pas de Calais ARCir PlantTEQ5National Science Foundation DBI-0209789Comisión Interministerial de Ciencia y Tecnología BIO2009-07040Junta de Andalucía P09-CVI-470

Chaco Culture National Historical Park: A Case Study

Looks at the management of CCNHP by the National Park Service. The long history of CCNHP as a heritage site provides an excellent illustration of how values emerge and evolve with new knowledge

A 2MASS Analysis of the Stability of Southern Bok Globules

We used near-infrared 2MASS data to construct visual extinction maps of a sample of Southern Bok globules utilizing the NICE method. We derived radial extinction profiles of dense cores identified in the globules and analyzed their stability against gravitational collapse with isothermal Bonnor-Ebert spheres. The frequency distribution of the stability parameter xi_max of these cores shows that a large number of them are located in stable states, followed by an abrupt decrease of cores in unstable states. This decrease is steeper for globules with associated IRAS point sources than for starless globules. Moreover, globules in stable states have a Bonnor-Ebert temperature of T = 15 +- 6 K, while the group of critical plus unstable globules has a different temperature of T = 10 +- 3 K. Distances were estimated to all the globules studied in this work and the spectral class of the IRAS sources was calculated. No variations were found in the stability parameters of the cores and the spectral class of their associated IRAS sources. On the basis of 13CO J = 1-0 molecular line observations, we identified and modeled a blue-assymetric line profile toward a globule of the sample, obtaining an upper limit infall speed of 0.25 km/s.Comment: 53 pages, 15 figures, accepted for publication in Ap

Opinion dynamics as a movement in a bistable potential

In this paper we investigate the model of opinion dynamics with anticonformity on a complete graph. We show that below some threshold value of anticonformal behavior spontaneous reorientations occur between two stable states. Dealing with a complete graph allows us also for analytical treatment. We show that opinion dynamics can be understood as a movement of a public opinion in a symmetric bistable effective potential. We focus also on the spontaneous transitions between stable states and show that a typical waiting time can be observed.Comment: 19 pages, 9 figure

ISW-LSS cross-correlation in coupled Dark Energy models with massive neutrinos

We provide an exhaustive analysis of the Integrated Sach-Wolfe effect (ISW) in the context of coupled Dark Energy cosmologies where a component of massive neutrinos is also present. We focus on the effects of both the coupling between Dark Matter and Dark Energy and of the neutrino mass on the cross-correlation between galaxy/quasar distributions and ISW effect. We provide a simple expression to appropriately rescale the galaxy bias when comparing different cosmologies. Theoretical predictions of the cross-correlation function are then compared with observational data. We find that, while it is not possible to distinguish among the models at low redshifts, discrepancies between coupled models and $\Lambda$CDM increase with $z$. In spite of this, current data alone seems not able to distinguish between coupled models and $\Lambda$CDM. However, we show that upcoming galaxy surveys will permit tomographic analysis which allow to better discriminate among the models. We discuss the effects on cross-correlation measurements of ignoring galaxy bias evolution, b(z), and magnification bias correction and provide fitting formulae for b(z) for the cosmologies considered. We compare three different tomographic schemes and investigate how the expected signal to noise ratio, snr, of the ISW-LSS cross-correlation changes when increasing the number of tomographic bins. The dependence of snr on the area of the survey and the survey shot noise is also discussed.Comment: 18 pages, 23 figures. Several major extensions. New sections and figures was added. ApJ in prin

Phase transition in the Sznajd model with independence

We propose a model of opinion dynamics which describes two major types of social influence -- conformity and independence. Conformity in our model is described by the so called outflow dynamics (known as Sznajd model). According to sociologists' suggestions, we introduce also a second type of social influence, known in social psychology as independence. Various social experiments have shown that the level of conformity depends on the society. We introduce this level as a parameter of the model and show that there is a continuous phase transition between conformity and independence

Serum and bal beta-d-glucan for the diagnosis of Pneumocystis pneumonia in HIV positive patients

Background/purposeThe diagnosis of patients with pulmonary infiltrates and human immunodeficiency virus (HIV) infection remains a challenge. In current clinical practice the gold standard for Pneumocystis jirovecii pneumonia (PCP) diagnosis remains the identification of the organism in bronco alveolar lavage (BAL) using microscopy (e.g., silver stain). (1->3)-β -d-glucan (BG) is a polysaccharide that is present within the cell wall of Pneumocystis and other fungi.MethodsWe analyzed serum and BAL lavage fluid from a cohort of 119 patients that did have HIV, a diagnosis of pneumonia and underwent bronchoscopy (FOB) for diagnosis of PCP.ResultsThe discriminative power of serum BG for the diagnosis of PCP in this group of patients was very high. Using a cutoff of 300 pg/mL, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 91%, 92%, 89% and 93% respectively. A model for ROC with just serum BG (N = 108) had an AUC of 0.95. Serum procalcitonin (PCT) and BAL BG were not as accurate for the diagnosis of PCP. For BAL BG using a cutoff of 783 pg/mL, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 72%, 79%, 72% and 79% respectively. The differences between the medians for serum PCT between the group with a without PCP did not reach statistical significance (p = 0.6137).ConclusionThe measurement of serum BG should be incorporated in the diagnostic work up of HIV positive patients with dyspnea and infiltrates on chest X X-ray. Our study confirms the diagnostic value of serum BG previously reported by others but we add a cutoff value that we believe is more accurate for patients with AIDS and suspicion of PCP

Duality and Four-Dimensional Black Holes

We consider the effects of abelian duality transformations on static, spherically-symmetric, asymptotically flat string spacetimes in four dimensions, where the dilaton, axion, metric, and gauge fields are allowed to be nonzero. Independent of the alpha' expansion, there is a six-parameter family of such configurations, labelled by the charges characterizing the asymptotic behaviour of the various fields: ie their mass, dilaton charge, axion charge, electric charge, magnetic charge, and Taub-NUT parameter. We show that duality, based on time-translation invariance, maps these solutions amongst themselves, with the effect of interchanging two pairs of these six labels, namely: (1) the mass and dilaton charge, and (2) the axion charge and the Taub-NUT parameter. We consider in detail the special case of the purely Schwarzschild black hole, for which the mass of the dual configuration vanishes to leading order in alpha'. Working to next-to-leading order in alpha' for the bosonic and heterotic strings, we find that duality takes a black hole of mass M to a (singular) solution having mass - 1/(alpha' M). Finally, we argue that two solutions which are related by duality based on a noncompact symmetry are {\it not} always physically equivalent.Comment: plain TeX, 37 pages, no figures. We have made some minor improvements in presentation and have included some additional reference