Determination of the absolute contours of optical flats

Emersons procedure is used to determine true absolute contours of optical flats. Absolute contours of standard flats are determined and a comparison is then made between standard and unknown flats. Contour differences are determined by deviation of Fizeau fringe

Hydrogen peroxide etching proves useful for germanium

Influence of process variations in the etching of germanium with hydrogen peroxide has been studied, along with damage effects due to radiation. The work advances the knowledge of the etching process for germanium

Looking for black-holes in X-ray binaries with XMM-Newton: XTE J1817-330 and XTE J1856+053

The X-ray binary XTE J1817-330 was discovered in outburst on 26 January 2006 with RXTE/ASM. One year later, another X-ray transient discovered in 1996, XTE J1856+053, was detected by RXTE during a new outburst on 28 February 2007. We triggered XMM-Newton target of opportunity observations on these two objects to constrain their parameters and search for a stellar black holes. We summarize the properties of these two X-ray transients and show that the soft X-ray spectra indicate indeed the presence of an accreting stellar black hole in each of the two systems.Comment: to appear in the proceedings of the Second Kolkata Conference on Observational Evidence for Black Holes in the Universe, Feb. 2008, Editor Sandip Chakrabarti, AI

Through Their Eyes: Using Photography with Youth Who Experienced Trauma

Adolescent youth in foster care are often exposed to multiple traumas and often leave the child welfare system without processing thoughts, feelings, or plans for the future. This study employed photo elicitation with a group of adolescent youth in foster care to discover what is important to them. Eight themes emerged. Family and friends, or the need to have someone who is always there for them was the most frequent theme photographed. Utilizing photo elicitation with youth who have been abused and/or neglected is an engaging and empowering method as it allows for individualized case planning that is guided by the wants and needs of the youth themselves

The Existential Philosophy of David Foster Wallace

It is no secret that philosophy and literature are often closely intertwined: beginning with works as old as Plato’s dialogues, philosophers have always seen the merit in utilizing fiction to share philosophy with both their contemporaries and with the general public. The most prominent existentialists are perhaps the most famous for using literature as a vehicle for their philosophical ideas: Friedrich Nietzsche, Søren Kierkegaard, Albert Camus, Simone de Beauvoir, and Jean-Paul Sartre all published some kind of fiction, through parables, novels, plays, and so forth. Likewise, I will argue in this thesis that renowned writer David Foster Wallace was not only a writer—though his career choice reflects his status as an author, the works he produced reflect his status as a philosopher

The Importance of Oedipus: Infamous Complex or Existential Hero?

The concept of free will is practically inescapable in modern day philosophy. Indeed, questions regarding the power of free will are of no shortage in philosophy: While one philosopher might assert that humans have absolute free will, another may accept free will as present but questions how powerful it is, while a third explores the implications of a deterministic universe in which there is a complete absence of free will, and so it goes on until an entire library can be filled with texts that deal exclusively with freedom. I make note of this modern captivation with the concept of free will not because I intend to add this work to the aforementioned figurative library, but to remind my reader of a simple, chronological fact: the ancient Greeks did not have a concept of free will, nor did they care to question the significance of such a notion. It is of the utmost importance that this fact be viewed not as a mere triviality; rather, this knowledge must be taken into account when considering any aspect of an ancient Greek text that, to the modern eye, appears to be concerned with a battle between free will and Determinism. To make an argument in which an ancient Greek author is portrayed as a supporter of the concept of absolute free will is an anachronistic fallacy and must be disputed as one. Resultantly, although Sophocles’ Oedipus Tyrannus looks to the modern eye to be a play centered around issues of Determinism and free will, it is no such thing; instead, the play addresses questions of choice, agency, and most of all, meaning. Through the lens of Albert Camus’ philosophy of the absurd, and backed by a philological investigation of the presence of ‘fate’ in the Sophoclean universe, I will argue that that Sophocles’ Oedipus Tyrannus gives a firm answer to if and how man can go on living in a world that he has discovered to be meaningless

How Chaotic is the Stadium Billiard? A Semiclassical Analysis

The impression gained from the literature published to date is that the spectrum of the stadium billiard can be adequately described, semiclassically, by the Gutzwiller periodic orbit trace formula together with a modified treatment of the marginally stable family of bouncing ball orbits. I show that this belief is erroneous. The Gutzwiller trace formula is not applicable for the phase space dynamics near the bouncing ball orbits. Unstable periodic orbits close to the marginally stable family in phase space cannot be treated as isolated stationary phase points when approximating the trace of the Green function. Semiclassical contributions to the trace show an $\hbar$ - dependent transition from hard chaos to integrable behavior for trajectories approaching the bouncing ball orbits. A whole region in phase space surrounding the marginal stable family acts, semiclassically, like a stable island with boundaries being explicitly $\hbar$-dependent. The localized bouncing ball states found in the billiard derive from this semiclassically stable island. The bouncing ball orbits themselves, however, do not contribute to individual eigenvalues in the spectrum. An EBK-like quantization of the regular bouncing ball eigenstates in the stadium can be derived. The stadium billiard is thus an ideal model for studying the influence of almost regular dynamics near marginally stable boundaries on quantum mechanics.Comment: 27 pages, 6 figures, submitted to J. Phys.

Tuberculosis in HIV-infected children in Europe, Thailand and Brazil: paediatric TB-HIV EuroCoord study

SETTING: Centres participating in the Paediatric European Network for Treatment of AIDS (PENTA), including Thailand and Brazil. OBJECTIVE: To describe the incidence, presentation, treatment and treatment outcomes of tuberculosis (TB) in human immunodeficiency virus (HIV) infected children. DESIGN: Observational study of TB diagnosed in HIV-infected children in 2011–2013. RESULTS: Of 4265 children aged <16 years, 127 (3%) were diagnosed with TB: 6 (5%) in Western Europe, 80 (63%) in Eastern Europe, 27 (21%) in Thailand and 14 (11%) in Brazil, with estimated TB incidence rates of respectively 239, 982, 1633 and 2551 per 100 000 person-years (py). The majority (94%) had acquired HIV perinatally. The median age at TB diagnosis was 6.8 years (interquartile range 3.0–11.5). Over half (52%) had advanced/severe World Health Organization stage immunodeficiency; 67 (53%) were not on antiretroviral therapy (ART) at TB diagnosis. Preventive anti-tuberculosis treatment was given to 23% (n = 23) of 102 children diagnosed with HIV before TB. Eleven children had unfavourable TB outcomes: 4 died, 5 did not complete treatment, 1 had recurrent TB and 1 had an unknown outcome. In univariable analysis, previous diagnosis of acquired immune-deficiency syndrome, not being virologically suppressed on ART at TB diagnosis and region (Brazil) were significantly associated with unfavourable TB outcomes. CONCLUSION: Most TB cases were from countries with high TB prevalence. The majority (91%) had favourable outcomes. Universal ART and TB prophylaxis may reduce missed opportunities for TB prevention