Blackfolds, plane waves and minimal surfaces

Minimal surfaces in Euclidean space provide examples of possible non-compact horizon geometries and topologies in asymptotically flat space-time. On the other hand, the existence of limiting surfaces in the space-time provides a simple mechanism for making these configurations compact. Limiting surfaces appear naturally in a given space-time by making minimal surfaces rotate but they are also inherent to plane wave or de Sitter space-times in which case minimal surfaces can be static and compact. We use the blackfold approach in order to scan for possible black hole horizon geometries and topologies in asymptotically flat, plane wave and de Sitter space-times. In the process we uncover several new configurations, such as black helicoids and catenoids, some of which have an asymptotically flat counterpart. In particular, we find that the ultraspinning regime of singly-spinning Myers-Perry black holes, described in terms of the simplest minimal surface (the plane), can be obtained as a limit of a black helicoid, suggesting that these two families of black holes are connected. We also show that minimal surfaces embedded in spheres rather than Euclidean space can be used to construct static compact horizons in asymptotically de Sitter space-times.

Die Schlacht bei Kolding, am 23sten April 1849 : Nach den besten und ausführlichsten Quellen: dienstlichen Berichten, Mittheilungen von Augenzeugen etc., bearbeitet und herausgegeben ; mit einem Plane des Schlachtfeldes

Welsch (Projektbearbeiter): Beschreibung der Schlacht von Kolding (22./23. April 1849): Sieg der schleswig-holsteinischen Armee unter Bonin über die Dänen unter Bülow

Die Schlacht bei Schleswig, am 23sten April 1848 : nach den besten und ausführlichsten Quellen: dienstlichen Berichten, Mittheilungen von Augenzeugen etc., bearbeitet und herausgegeben ; mit einem Plane des Schlachtfeldes

Welsch (Projektbearbeiter): Darstellung der Schlacht bei Schleswig: Sieg der von preußischen und anderen Bundestruppen unterstützten schleswig-holsteinischen Armee über die Dänen (23. April 1848)

Der Kampf in Dresden im Mai 1849 : mit einem Plane ; mit besonderer Rücksicht auf die Mitwirkung der Preußischen Truppen geschildert und militairisch beleuchtet

Boberach: Die Darstellung berücksichtigt besonders die neuen Erfahrungen mit dem Straßen- und Häuserkampf, die Eisenbahnen als Truppenbeförderungsmittel, die Erprobung des Zündnadelgewehrs

Die Erlebnisse der Schweizerkompagnie in Venedig : ein Beitrag zur Geschichte des venetianischen Freiheitskampfes ; mit einem Plane von Venedig und den Lagunen

Boberach: Schweizer Freiwillige aus einem Dorf zwischen Thurgau und Zürich haben am Kampf gegen die österreichische Herrschaft im Juni 1848 teilgenommen

Die Berliner Märztage: vom militairischen Standpunkte aus geschildert : mit einem Plane

Boberach: Der Rückzug der Truppen war militärisch nicht nötig, die Ausgangslage für eine Unterdrückung der revolutionären Bewegung günstig, aber Arnim und Bodelschwingh haben den König falsch beraten. - Welsch (Projektbearbeiter): Verfaßt vom preußischen Obersten K. G. Schulz im Auftrag des Generals v. Prittwitz [Hachtmann, R.: Berlin 1848; 1997, S. 54, Anm. 86]. Prittwitz war im März 1848 Kommandeur des Berliner Gardekorps und leitete den Kampf gegen die Berliner Aufständischen

Burrowing in Marine Muds by Crack Propagation: Kinematics and Forces

The polychaete Nereis virens burrows through muddy sediments by exerting dorsoventral forces against the walls of its tongue-depressor- shaped burrow to extend an oblate hemispheroidal crack. Stress is concentrated at the crack tip, which extends when the stress intensity factor (K-I) exceeds the critical stress intensity factor (K-Ic). Relevant forces were measured in gelatin, an analog for elastic muds, by photoelastic stress analysis, and were 0.015 +/- 0.001 N (mean +/- s.d.;N= 5). Measured elastic moduli (E) for gelatin and sediment were used in finite element models to convert the forces in gelatin to those required in muds to maintain the same body shapes observed in gelatin. The force increases directly with increasing sediment stiffness, and is 0.16 N for measured sediment stiffness of E=2.7x10(4) Pa. This measurement of forces exerted by burrowers is the first that explicitly considers the mechanical behavior of the sediment. Calculated stress intensity factors fall within the range of critical values for gelatin and exceed those for sediment, showing that crack propagation is a mechanically feasible mechanism of burrowing. The pharynx extends anteriorly as it everts, extending the crack tip only as far as the anterior of the worm, consistent with wedge-driven fracture and drawing obvious parallels between soft-bodied burrowers and more rigid, wedge-shaped burrowers(i.e. clams). Our results raise questions about the reputed high energetic cost of burrowing and emphasize the need for better understanding of sediment mechanics to quantify external energy expenditure during burrowing.

Versuch einer Darstellung der allgemeinen Geschichte, nach dem Plane des seligen Herrn Professors Franz Joseph von Mumelter

von Franz de Paula Michael Reisser

Prag und seine Umgebungen : Mit einem Anhange, einem Plane der Stadt, und vier Ansichten, dann einer Postkarte und einem Briefposten-Tableau durch Böhmen

von C. E. Rainold

H.G. Ollendorff's neue Methode, in sechs Monaten eine Sprache lesen, schreiben und sprechen zu lernen : Anleitung zur Erlernung der polnischen Sprache nach einem neuen und vollständigeren Plane für den Schul- und Privatunterricht

verfaßt von M. Joel, Lehrer der slawischen Sprachen und Literatur

Antiretroviral therapy adherence and the use of condoms among African American HIV-positive crack cocaine users

Safer sex practices, such as consistent condom use, are essential to reduce HIV transmission. Determining causes and/or co-variants related to the likelihood of participating in high-risk sexual behaviors may allow the content of interventions and treatments to minimize HIV transmission to be tailored more effectively. The goal of this study was to examine whether a relationship exists between consistent condom use among African American HIV-positive crack cocaine users and both (1) the use of antiretroviral therapy, and (2) adherence to antiretroviral therapy regimens. The study population consisted of 390 participants. They were at least 18 years old, African American, HIV-positive, and had used crack cocaine within a month prior to an interview conducted sometime between April, 2004, and September, 2007. Bivariate associations were examined using contingency tables and χ2-statistics. The Mantel-Haenszel method was used to control for confounding. This study found neither a significant relationship between use of antiretroviral therapy and consistent condom use (Odds ratio (OR) = 1.38; 95% Confidence interval (95%CI) = 0.86–2.22), nor an association between antiretroviral therapy adherence and consistent condom use (OR = 1.02, 95%CI = 0.60–1.75). The exception was more consistent condom use when sex was traded for money or drugs in those on antiretroviral therapy, compared to those not on such therapy (OR = 2.28, 95%CI = 1.08–4.85). Further studies examining condom use and HIV treatment adherence are recommended. ^

Crack and powder cocaine federal legislation: A sentencing disparity and potential for policy improvement

Since its introduction into the United States in the 1980s, crack cocaine has been a harsh epidemic that has taken its toll on a countless number of people. This highly addictive, cheap and readily available drug of abuse has permeated many demographic sectors, mostly in low income, lesser educated, and urban communities. This epidemic of crack cocaine use in inner city areas across the Unites States has been described as an expression of economic marginality and “social suffering” coupled with the local and international forces of drug market economies (Agar 2003). As crack cocaine is a derivative of cocaine, it utilizes the psychoactive component of the drug, but delivers it in a much stronger, quicker, and more addictive fashion. This, coupled with its ready availability and cheap price has allowed for users to not only become very addicted very quickly, but to be subject to the stringent and sometimes unequal or inconsistent punishments for possession and distribution of crack-cocaine. ^ There are many public health and social ramifications from the abuse of crack-cocaine, and these epidemics appear to target low income and minority groups. Public health issues relating to the physical, mental, and economic strain will be addressed, as well as the direct and indirect effects of the punishments that come as a result of the disparity in penalties for cocaine and crack-cocaine possession and distribution. ^ Three new policies have recently been introduced into the United Stated Congress that actively address the disparity in sentencing for drug and criminal activities. They are, (1) Powder-Crack Cocaine Penalty Equalization Act of 2009, (HR 18, 111th Cong. 2009), (2) The Drug Sentencing Reform and Cocaine Kingpin Trafficking Act of 2009, (HR 265, 111th Cong. 2009) and (3) The Justice Integrity Act of 2009, (111th Cong. 2009). ^ Although they have only been initiated, if passed, they have potential to not only eliminate the crack-cocaine disparity, but to enact laws that help those affected by this epidemic. The final and overarching goal of this paper is to analyze and ultimately choose the ideal policy that would not only eliminate the cocaine and crack disparity regardless of current or future state statutes, but will provide the best method of rehabilitation, prevention, and justice. ^

Changes in sexual behaviors associated with crack cocaine cessation among African Americans in Houston, Texas

Aim To examine the association between the crack cocaine cessation and risky sexual behaviors. Design and setting Between June 2002 and March 2005, a sample of African-American residents of Houston, Texas who were using crack at the time of enrollment participated in a cohort study to evaluate per outreach interventions to reduce HIV risk behaviors. The sample for this study consisted of 351 women and men who completed structured surveys at baseline and at six months about socio-demographic characteristics, drug use, and sexual behaviors. Multivariate logistic regression was used to analyze the association between crack cessation and risky sexual behaviors at follow-up, while controlling for confounding characteristics. Measurements Crack cessation was defined as reporting no crack use in the 30 days prior to the follow-up interview. Possible associated factors included unprotected sex, having multiple sex partners, trading sex for money/drugs, crack use, and socio-demographic variables. Findings At the six-month follow-up interview, 21% of participants reported that they had not used crack in the previous 30 days. For women, crack cessation was significantly associated with having only one sex partner at follow-up; for men, crack cessation was significantly associated with being single, separated, or divorced at baseline, having only one sex partner at follow-up, and initiating protected sex by follow-up. Conclusion These findings support previous research indicating that crack use is associated with unprotected sex and multiple sexual partners, as men and women who ceased crack use were less likely to engage in these risky sexual behaviors. Findings demonstrate that treatment for crack use could have a meaningful effect on risky sexual behaviors and HIV/STI prevention.^