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Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.

Author(s): M. Ahmadi [1]; B. X. R. Alves [2]; C. J. Baker [3]; W. Bertsche [4, 5]; E. Butler [6]; A. Capra [7]; C. Carruth [8]; C. L. Cesar [9]; [...]

Author(s): M. Ahmadi [1]; B. X. R. Alves [2]; C. J. Baker [3]; W. Bertsche [4, 5]; E. Butler [6]; A. Capra [7]; C. Carruth [8]; C. L. Cesar [9]; [...]

Author(s): M. Ahmadi; B. X. R. Alves; C. J. Baker; W. Bertsche; E. Butler; A. Capra; C. Carruth; C. L. Cesar; M. Charlton; S. Cohen; R. Collister; S. Eriksson; A. [...]

This prospective study determined the rate of abandonment of sildenafil therapy and assessed the reasons for abandonment. Between January 2001 and December 2002, 234 patients with erectile dysfunction (ED) at three independent centers successfully began therapy with sildenafil 50 or 100?mg. The rate of noncompliance was 31%. A telephone survey of these patients was conducted to determine the reasons for abandonment. The majority reported that they had had no opportunity or desire for sexual intercourse or that their partners had shown no sexual interest. Few patients stated that the high cost of the medication or that adverse events were the cause.International Journal of Impotence Research (2005) 17, 2-4. doi:10.1038/sj.ijir.3901252 Published online 17 June 2004 [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Male Sexual Dysfunction: Diagnosis and Treatment From a Sexological and Interdisciplinary Perspective," by Dirk Rösing and colleagues in the previous issue.

Background: Few methodologically rigorous international comparisons of student-reported antisocial behavior have been conducted. This paper examines whether there are differences in the frequency of both antisocial behavior and societal responses to antisocial behavior in Victoria, Australia and Washington State, United States. These 2 states were chosen due to their similarities on sociodemographic characteristics and their differences in policy frameworks around problem behavior including antisocial behavior and substance use., Methods: State representative samples of students (N = 5769) in school grades 5, 7, and 9 in Victoria and Washington State completed a modified version of the Communities That Care self-report survey of behavior and societal responses to behavior. Chi-square analyses compared frequencies of antisocial behavior, school suspensions, and police arrests in the 2 states. Multivariate logistic regression analyses were conducted for each outcome measure to examine the effect of state, controlling for sample design, clustering of students within schools, age, socioeconomic status, and urbanicity., Results: Few state differences in student-reported antisocial behavior were found, although frequencies varied across behavior type and grade level. Differences in societal responses were observed across grade levels with grade 5 Washington students reporting higher rates of school suspension. Older Washington students reported more arrests., Conclusions: Rates of student antisocial behavior appear similar in these 2 states in Australia and the United States. However, youth in the United States relative to Australia may experience greater societal consequences for problem behavior. Further research is required to examine the impact of these consequences on subsequent behavior.

Using mail survey data collected from primary and secondary school administrators in Washington State, United States, and in Victoria, Australia, this study compared aspects of the school drug policy environment in the 2 states. Documented substance-use policies were prevalent in Washington and Victoria but less prevalent.in primary schools, especially in Victoria. Victorian school policy-setting processes were significantly more likely to involve teachers, parents, and students than processes in Washington schools. Consistent with expectations based on their respective national drug policy frameworks, school drug policies in Washington schools were more oriented toward total abstinence and more frequently enforced with harsh punishment (such as expulsion or calling law enforcement), whereas policies in Victorian schools were more reflective of harm-minimization principles. Within both states, however, schools more regularly used harsh punishment and remediation consequences for alcohol and illicit-drug violations compared to tobacco policy violations, which were treated more leniently.

Monotherapy of hepatitis C virus infection with either alpha interferon or ribavirin alone is rather ineffective, while the use of the two antivirals together is much more efficacious. In vitro drug-drug combination analysis utilizing related members of the family Flaviviridae, bovine viral diarrhea virus and yellow fever virus, revealed significant direct synergistic interactions between these drugs' antiviral activities that might explain this clinical observation.