W. Cameron Forbes and the Hoover commissions to Haiti, 1961

Thesis (Ph.D.)--Boston Universit

A BPS Interpretation of Shape Invariance

We show that shape invariance appears when a quantum mechanical model is invariant under a centrally extended superalgebra endowed with an additional symmetry generator, which we dub the shift operator. The familiar mathematical and physical results of shape invariance then arise from the BPS structure associated with this shift operator. The shift operator also ensures that there is a one-to-one correspondence between the energy levels of such a model and the energies of the BPS-saturating states. These findings thus provide a more comprehensive algebraic setting for understanding shape invariance.Comment: 15 pages, 2 figures, LaTe

Padronização de uma bateria para a avaliação de fatores de risco psicossociais trabalhistas em trabalhadores colombianos

A battery of questionnaires to assess psychosocial risk factors at work was developed in 2010 in response to Resolution 2646 created by the Colombian Ministry of Social Protection. However, this battery presents some theoretical and practical limitations. A new battery of instruments has been designed and validated that includes instruments and risk indicators of the demand-control-social support and the effort-reward imbalance models. Other factors, not included in these models, but that Resolution 2646 suggests should be assessed, have also been added, and with this additional information, the new battery allows us to also calculate a “global indicator” of demand, control, and social support; family and social risk conditions, coping and personality; and health and wellbeing. The new battery was administered to a sample of 16,095 workers from different occupations and representative Colombian regions. An analysis of the various domains indicates that internal consistency of the various scales is high. The new battery has the following properties: it is simple to use in paper format or when administered by computer, it enables comparison between occupations, it offers unified scores for each variable, and provides information to assess the risk factors suggested by Resolution 2646. In addition, it will make it possible to compare the results obtained when analyzing Colombian workers with those obtained from studies of workers from other countries.Em 2010, desenvolveu-se uma bateria de instrumentos para avaliar fatores psicossociais trabalhistas de risco para a saúde, em resposta à Resolução 2 646 do Ministério da Proteção Social da Colômbia. Contudo, esta conta com algumas limitações que, a partir da construção e da validação de uma nova bateria, neste estudo se pretendem superar. Além disso, a nova bateria oferece recursos adicionais para a avaliação desses fatores: a presente bateria incorpora os instrumentos e os indicadores centrais dos modelos demanda-controle-apoio social e desiquilíbrio esforço-recompensa e os fatores internos do trabalho não considerados nesses modelos, mas que a Resolução considera necessários, mediram-se com testes preexistentes ou desenvolvidos pelos autores. Com os dados coletados, é possível calcular indicadores globais de demanda, controle e apoio social; além de condições familiares e sociais de risco, enfrentamento, personalidade e indicadores de saúde e bem-estar. Para a validação, a bateria foi aplicada a uma amostra de 16 095 trabalhadores de diferentes cargos e municípios colombianos. As anál i ses de consistência interna e validade permitem afirmar que a bateria é simples de aplicar em papel ou digital, permitirá comparar cargos, obter pontuações unificadas por variável, oferecer um diagnóstico de um número importante das variáveis sugeridas na Resolução bem como permitirá comparar os resultados dos trabalhadores colombianos com os de outros países. Palavras-chave: fatores trabalhistas de risco psicossocial, Resolução 2 646 de 2008, modelo demanda-controle-apoio social, modelo desiquilíbrio esforço-recompensa, estresse profissional, avaliação.En 2010 se desarrolló una batería de instrumentos para evaluar factores psicosociales laborales de riesgo para la salud, en respuesta a la Resolución 2646 de 2008 del Ministerio de la Protección Social de Colombia. Sin embargo, esta cuenta con algunas limitaciones que, a partir de la construcción y validación de una nueva batería, en el presente estudio se buscan superar. La nueva batería ofrece recursos adicionales para la evaluación de estos factores: incorpora los instrumentos e indicadores centrales de los modelos demanda-control-apoyo social y desequilibrio esfuerzo-recompensa, y los factores intralaborales no contemplados en dichos modelos, pero que la Resolución considera necesarios, se midieron con pruebas preexistentes o desarrolladas por los autores. Con los datos recolectados es posible calcular indicadores globales de demanda, control y apoyo social; además de condiciones familiares y sociales de riesgo, afrontamiento, personalidad e indicadores de salud y bienestar. Para la validación, la batería se aplicó a una muestra de 16.095 trabajadores de diferentes ocupaciones y municipios colombianos. Los análisis de consistencia interna y validez permiten afirmar que la batería es sencilla de aplicar en papel o por computador, permitirá comparar ocupaciones, obtener puntuaciones unificadas por variable, ofrecer un diagnóstico de un número importante de las variables sugeridas en la Resolución y comparar los resultados de los trabajadores colombianos con los de otros países

Combination of suicide and cytokine gene therapies as surgery adjuvant for canine mammary carcinoma

The incidence of canine mammary carcinoma varies with age, breed, and spay status, being among the main tumors appearing in intact female dogs. Thirty-six canine mammary carcinoma patients received injections of canine interferon-β (cIFN-β) and HSV-thymidine kinase/ganciclovir (HSV-tk/GCV) carrying lipoplexes, into the tumor bed, immediately after surgery. Next, they started periodic subcutaneous injections of lipoplexes carrying a human granulocyte-macrophage colony stimulating factor and interleukin-2mixedwith allogeneicmammary carcinoma extracts. This combined strategy was safe and well tolerated. In addition, only two out of 26 patients treated with complete surgery developed a local relapse, and 0 out of 29 stage II and III patients displayed distant metastases, suggesting both local and systemic antitumor activities. The most encouraging result was the long survival times: 22 > 1 year (where 13 > 2 and 4 > 3 years), while maintaining a good quality of life. The preliminary results in five patients presenting with local disease, an additional HSV-tk/GCV plus cIFN-β gene treatment induced local antitumor activity, evidenced by four objective responses (one complete, three partial) and one stable disease. This successful outcome supports further studies to validate this approach not only for canine veterinary patients, but also for translation to human patients.Fil: Finocchiaro, Liliana Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Dr. Ángel Roffo". Unidad de Transferencia Genética; ArgentinaFil: Spector, Agustina I. M.. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Dr. Ángel Roffo". Unidad de Transferencia Genética; ArgentinaFil: Agnetti, Lucrecia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Dr. Ángel Roffo". Unidad de Transferencia Genética; ArgentinaFil: Arbe, María Florencia. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Dr. Ángel Roffo". Unidad de Transferencia Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Glikin, Gerardo Claudio. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Dr. Ángel Roffo". Unidad de Transferencia Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Silicon photonics devices for integrated analog signal processing and sampling

Silicon photonics offers the possibility of a reduction in size weight and power for many optical systems, and could open up the ability to build optical systems with complexities that would otherwise be impossible to achieve. Silicon photonics is an emerging technology that has already been inserted into commercial communication products. This technology has also been applied to analog signal processing applications. MIT Lincoln Laboratory in collaboration with groups at MIT has developed a toolkit of silicon photonic devices with a focus on the needs of analog systems. This toolkit includes low-loss waveguides, a high-speed modulator, ring resonator based filter bank, and all-silicon photodiodes. The components are integrated together for a hybrid photonic and electronic analog-to-digital converter. The development and performance of these devices will be discussed. Additionally, the linear performance of these devices, which is important for analog systems, is also investigated

Differential Development of the Ventral Visual Cortex Extends Through Adolescence

The ventral temporal cortex (VTC) in humans includes functionally defined regions that preferentially respond to objects, faces, and places. Recent developmental studies suggest that the face selective region in the fusiform gyrus (‘fusiform face area’, FFA) undergoes a prolonged development involving substantial increases in its volume after 7 years of age. However, the endpoint of this development is not known. Here we used functional magnetic resonance imaging (fMRI) to examine the development of face-, object- and place selective regions in the VTC of adolescents (12–16 year olds) and adults (18–40 year olds). We found that the volume of face selective activations in the right fusiform gyrus was substantially larger in adults than in adolescents, and was positively correlated with age. This development was associated with higher response amplitudes and selectivity for faces in face selective regions of VTC and increased differentiation of the distributed response patterns to faces versus non-face stimuli across the entire VTC. Furthermore, right FFA size was positively correlated with face recognition memory performance, but not with recognition memory of objects or places. In contrast, the volume of object- and place selective cortical regions or their response amplitudes did not change across these age groups. Thus, we found a striking and prolonged development of face selectivity across the VTC during adolescence that was specifically associated with proficiency in face recognition memory. These findings have important implications for theories of development and functional specialization in VTC

Influence of Phase Matching on the Cooper Minimum in Ar High Harmonic Spectra

We study the influence of phase matching on interference minima in high harmonic spectra. We concentrate on structures in atoms due to interference of different angular momentum channels during recombination. We use the Cooper minimum (CM) in argon at 47 eV as a marker in the harmonic spectrum. We measure 2d harmonic spectra in argon as a function of wavelength and angular divergence. While we identify a clear CM in the spectrum when the target gas jet is placed after the laser focus, we find that the appearance of the CM varies with angular divergence and can even be completely washed out when the gas jet is placed closer to the focus. We also show that the argon CM appears at different wavelengths in harmonic and photo-absorption spectra measured under conditions independent of any wavelength calibration. We model the experiment with a simulation based on coupled solutions of the time-dependent Schr\"odinger equation and the Maxwell wave equation, including both the single atom response and macroscopic effects of propagation. The single atom calculations confirm that the ground state of argon can be represented by its field free $p$ symmetry, despite the strong laser field used in high harmonic generation. Because of this, the CM structure in the harmonic spectrum can be described as the interference of continuum $s$ and $d$ channels, whose relative phase jumps by $\pi$ at the CM energy, resulting in a minimum shifted from the photoionization result. We also show that the full calculations reproduce the dependence of the CM on the macroscopic conditions. We calculate simple phase matching factors as a function of harmonic order and explain our experimental and theoretical observation in terms of the effect of phase matching on the shape of the harmonic spectrum. Phase matching must be taken into account to fully understand spectral features related to HHG spectroscopy

Evidence for a nuclear compartment of transcription and splicing located at chromosome domain boundaries

The nuclear topography of splicing snRNPs, mRNA transcripts and chromosome domains in various mammalian cell types are described. The visualization of splicing snRNPs, defined by the Sm antigen, and coiled bodies, revealed distinctly different distribution patterns in these cell types. Heat shock experiments confirmed that the distribution patterns also depend on physiological parameters. Using a combination of fluorescencein situ hybridization and immunodetection protocols, individual chromosome domains were visualized simultaneously with the Sm antigen or the transcript of an integrated human papilloma virus genome. Three-dimensional analysis of fluorescence-stained target regions was performed by confocal laser scanning microscopy. RNA transcripts and components of the splicing machinery were found to be generally excluded from the interior of the territories occupied by the individual chromosomes. Based on these findings we present a model for the functional compartmentalization of the cell nucleus. According to this model the space between chromosome domains, including the surface areas of these domains, defines a three-dimensional network-like compartment, termed the interchromosome domain (ICD) compartment, in which transcription and splicing of mRNA occurs

Cognitive leisure activities and future risk of cognitive impairment and dementia: systematic review and meta-analysis

BACKGROUND: As life expectancies continue to rise, modifiable lifestyle factors that may prevent cognitive decline and dementia in later life become increasingly important in order to maintain quality of life in old age. METHODS: Five meta-analyses were conducted on data from papers identified in a systematic review. Studies were grouped according to outcomes (dementia, cognitive impairment including amnestic Mild Cognitive Impairment (aMCI), Mild Cognitive Impairment (MCI), and cognitive decline) and output (risk (RR), odds (OR), or hazard ratios (HR)). RESULTS: Nineteen studies met our inclusion criteria and quality assessments. Four of five meta-analyses showed significant associations between participation in cognitive leisure activities and reduced risk of cognitive impairment (OR = 0.69, 95% CI: 0.56-0.85) and dementia (HR = 0.58, 95% CI: 0.46-0.74; RR = 0.61, 95% CI: 0.42-0.90; OR = 0.78, 95% CI: 0.67-0.90). However, one pooled analysis of cognitive impairment studies did not reach significance (HR = 0.85, 95% CI: 0.71-1.02). Mentally stimulating leisure activities were significantly associated with later life cognition (β = 0.11, p = 0.05), better memory (β = 0.20, 95% CI: 0.11-0.29), speed of processing (β = 0.37, 95% CI: 0.29-0.45), and executive functioning (β = 0.23, 95% CI: 0.15-0.29), and less decline in overall cognition (β = -0.23, p < 0.01), language (β = -0.11, p < 0.05), and executive functioning (β = -0.13, p < 0.05). Activities were also shown to reduce rate of cognitive decline (estimate = 0.03, SE = 0.01, p = 0.00). CONCLUSIONS: There is increasing evidence that participation in cognitively stimulating leisure activities may contribute to a reduction of risk of dementia and cognitive impairment in later life. Promoting involvement in such activities across lifespan could be an important focus for primary prevention strategies for governments and health services

Psychological treatments for depression and anxiety in dementia and mild cognitive impairment

BACKGROUND: Experiencing anxiety and depression is very common in people with dementia and mild cognitive impairment (MCI). Psychological interventions have been suggested as a potential treatment for these populations. Current research suggests that people with dementia and MCI have limited opportunities for psychological treatments aimed at improving their well-being. A systematic review of the evidence on their effectiveness is likely to be useful in terms of improving outcomes for patients and for future recommendations for practice. OBJECTIVES: The main objective of this review was to assess the effectiveness of psychological interventions in reducing anxiety and depression in people with dementia or mild cognitive impairment (MCI). SEARCH METHODS: We searched the Cochrane Dementia and Cognitive Improvement Group Specialized Register and additional sources for both published and unpublished data. Selection criteria We included randomised controlled trials (RCTs) comparing a psychological intervention with usual care or a placebo intervention (social contact control) in people with dementia or MCI. DATA COLLECTION AND ANALYSIS: Two review authors worked independently to select trials, extract data and assess studies for risk of bias, using a data extraction form. We contacted authors when further information was not available from the published articles. MAIN RESULTS: Six RCTs involving 439 participants with dementia were included in the review, but no studies of participants with MCI were identified. The studies included people with dementia living in the community or in nursing home care and were carried out in several countries. Only one of the studies was classified as low risk of bias. Five studies were at unclear or high risk of bias due to uncertainties around randomisation, blinding and selective reporting of results. The studies used the different psychological approaches of cognitive behavioural therapy (CBT), interpersonal therapy and counselling. Two studies were of multimodal interventions including a specific psychological therapy. The comparison groups received either usual care, attention-control educational programs, diagnostic feedback or services slightly above usual care. Meta-analysis showed a positive effect of psychological treatments on depression (6 trials, 439 participants, standardised mean difference (SMD) -0.22; 95% confidence interval (CI) -0.41 to -0.03, moderate quality evidence) and on clinician-rated anxiety (2 trials, 65 participants, mean difference (MD) -4.57; 95% CI -7.81 to -1.32, low quality evidence), but not on self-rated anxiety (2 trials, SMD 0.05; 95% CI -0.44 to 0.54) or carer-rated anxiety (1 trial, MD -2.40; 95% CI -4.96 to 0.16). Results were compatible with both benefit and harm on the secondary outcomes of patient quality of life, activities of daily living (ADLs), neuropsychiatric symptoms and cognition, or on carers' self-rated depressive symptoms, but most of the studies did not measure these outcomes. There were no reports of adverse events. AUTHORS' CONCLUSIONS: We found evidence that psychological interventions added to usual care can reduce symptoms of depression and clinician-rated anxiety for people with dementia. We conclude that psychological interventions have the potential to improve patient well-being. Further high quality studies are needed to investigate which treatments are most effective and to evaluate the effect of psychological interventions in people with MCI