Universidad Nacional de San Martín: Portal de Revistas Academicas
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Characterization of Internal Organ Motion Using Skin Marker Positions
No full textInternal organ motion due to breathing is a phenomenon that nullifies the rigidity assumptions in many interventional applications, ranging from image guided needle biopsies to external beam radiation therapy. In this paper, we propose a method to correlate and characterize internal organ motion with the location of skin markers. The method utilizes a MR time sequence along with tracked magnetic marker positions to establish the correlation. We perform a validation study to quantify the degree of the accuracy and the reproducibility of this correlation. The results demonstrate that patient specific correlation of internal motion and skin markers can be established and the target positioning accuracy of better than 15% of the maximum range of the target movement can be achieved
Youth Trauma Histories are Associated with Under-diagnosis and Under-treatment of Co-occurring Youth Psychiatric Symptoms
No full textObjective: We examined whether in the presence of trauma exposure, non-traumatic stress-related symptoms are interpreted by mental health clinicians as less salient than the trauma exposure and are de-emphasized as a treatment target, consistent with a diagnostic overshadowing bias.
Methods: Using an adapted version of a diagnostic overshadowing bias experimental paradigm, mental health clinicians (N = 266, M age = 34.4 years, 82% female) were randomly assigned to receive two of six clinical vignette variations. Vignette 1 described an adolescent with obsessive-compulsive disorder (OCD). Vignette 2 described a pre-adolescent with oppositional defiant disorder (ODD). Vignettes were identical except for whether the youth reported exposure to a potentially traumatic event (PTE; no PTE, sexual PTE, or physical PTE). Clinicians received one vignette with a PTE and one without, counterbalancing order. Clinicians rated the likelihood the youth met criteria for various diagnoses and the appropriateness of various treatments on 7-point scales.
Results: Across both vignettes, clinicians rated the target diagnosis (OCD in Vignette 1, ODD in Vignette 2) as less likely for vignettes with a PTE than for the same vignettes without a PTE. Clinicians also rated evidence-based treatment modalities for target diagnoses as less appropriate in the presence of a PTE than when a PTE was present.
Conclusions: Consistent with possible bias, clinicians may under-recognize and under-treat non-traumatic stress-related mental health symptoms in youth with a co-occurring trauma history. Future work to validate this bias in real-world practice is indicated
Lost in the Developing World Star Trek: Voyager
No full textStar Trek: Voyager (1995–2001) represents a metaphor of being lost in the so-called Third World. Through this metaphor, Voyager focuses on two specific motifs: pragmatism1 and race relations. The show begins when the star ship Voyager is transported seventy thousand light years from Federation space. It is estimated that to get back to Earth it would take Voyager 75 years using the propulsion means at its disposal. During the course of its daunting effort to traverse this massive expanse of space, the Voyager crew encounters numerous situations fraught with moral/ethnic quandaries. In facing these quandaries/dilemmas, Voyager has to decide whether to be expeditious (pragmatic) in trying to get home, or to prioritize their ethical/moral principles (thereby endangering themselves and their chances of getting home). The strength of the show, in my estimation, is that the Voyager crew consistently chooses to be ethical even in the face of death (or remaining stranded). Moreover, certain villains in the Voyager series are dastardly precisely because they prioritize pragmatism over principle
Instanton Floer Homology
No full textAndreas Floer [93] associated with every integral homology 3-sphere eight finitely generated abelian groups In(Σ), n = 0,..., 7, which are now referred to as the (instanton) Floer homology. The Floer homology is an invariant of orientation preserving diffeomorphism. It is a refinement of the Casson invariant λ(Σ) in that λ(Σ) is half the Euler characteristic of I*(Σ). The definition of I*(Σ) relies heavily on gauge theory in dimensions three and four. In this chapter, we define I*(Σ), review its properties, and give examples of calculations. We also explain relations between I*(Σ) and the symplectic Floer homology, between I*(Σ) and Donaldson polynomials, and describe various extensions of I*(Σ)
Fluorescence Spectroscopic Studies of Proteins
No full textFluorescence spectroscopy has emerged as one of the most important tools in the study of protein structure and function. Sensitivity of the fluorescence techniques is a major advantage. Although it cannot provide total structure like X-ray crystallography or nuclear magnetic resonance (NMR), the sensitivity of the technique allows one to work at or near the intracellular concentrations of macro-molecules and ligands. This is particularly important for proteins that self-associate at higher concentrations. Although steady-state fluorescence spectra can now be easily obtained and steady-state fluorometers are inexpensive and widely available, they suffer from several disadvantages
Achieving Enantio and Diastereoselectivities in Photoreactions Through the Use of a Confined Space
No full textThe efforts of chemists during the past few decades have advanced the field of thermal asymmetric synthesis to a great extent [1]. Complex molecules can now be synthesized as single enantiomers. Unfortunately, asymmetric photochemical reactions have not enjoyed the same level of success [2]. In the past, chiral solvents, chiral auxiliaries, circularly polarized light, and chiral sensitizers have been utilized to conduct enantioselective photoreactions. The highest chiral induction achieved by any of these approaches at ambient temperature and pressure has been ~30% (2–10% e.e. is common in photochemical reactions under the above conditions). Crystalline state and solid host-guest assemblies have, on the other hand, provided the most encouraging results [3]. Two approaches have been used to achieve chiral induction in the crystalline state. In one, by the Weizmann Institute Group, the achiral reactant is crystallized into a chiral space group [4]. The limited chances of such crystallization of organic molecules renders this approach less general. In the second approach, due to Scheffer and co-workers [5], an ionic chiral auxiliary is used to effect a chiral environment. This limits the approach to molecules with carboxylic acid groups that form crystallizable salts with chiral amines or vice versa. Yet another successful approach due to Toda and co-workers [6] has made use of organic hosts that contain chiral centers (e.g., deoxycholic acid, cyclodextrin, 1,6-bis (o-chlorophenyl)-1,6-diphenyl-2,4-diyne-1,6-diol,). The success of this approach is limited to guests that can form solid solutions with the host without disturbing the hosts macro-structure. The reactivity of molecules in the crystalline state and in solid host-guest assemblies is controlled by the details of molecular packing. Currently, molecular packing and consequently the chemical reactivity in the crystalline state, can not be reliably predicted [7]. Therefore even after successfully crystallizing a molecule in a chiral space group or complexing a molecule with a chiral host or a chiral auxiliary, there is no guarantee that the guest will react in the crystalline state. Hence, even though crystalline and host-guest assemblies have been very useful in conducting enantioselective photoreactions, their general applicability thus far has been limited
LAND: Land Access for Neighborhood Development
No full textThe Land Access Neighborhood Development (LAND) mapping tool visualizes the distribution of local institutional and government-owned vacant, as well as underused properties. Developed by the University of Miami (UM)’s Office of Civic and Community Engagement (CCE), in collaboration with the UM Institute for Data Science and Computing, and with support from Citi Community Development, LAND will enable policymakers and community-based organizations to identify potential development opportunities for affordable housing in transit-served areas