3,466 research outputs found
Introduction to Using the Window System
This document is a draft copy of a portion of the Lisp Machine window system manual. It is being published in this form now to make it available, since the complete window system manual is unlikely to be finished in the near future. The information in this document is accurate as of system 67, but is not guaranteed to remain 100% accurate. To understand some portions of this document may depend on background information which is not contained in any published documentation.
This paper is a portion of a document which will explain how a programmer may make use of and extend the facilities in the Lisp machine known collectively as the Window System.MIT Artificial Intelligence Laborator
A Culturally Competent Phenotypic Evaluation / Obesity Assessment in African and African American Populations: Pilot Study
BMI, a ratio of weight over height, is a culturally-biased tool imposed upon the scientific, academic and medical communities as an errant measure of obesity across ethnic - ity. Body Mass Index (BMI) relates mass (g) to a relative fat distribution with regards to height. Its genesis is from the actuarially derived and ethnically exclusive height and weight tables that promote the fictional notion of inter-eth - nic ideal weights that would be later adopted by the Na - tional Institutes of Health (NIH) as a competent measure of adiposity. Best practice, movement towards individualized medicine and deployment of effective models that impact the diabetes epidemic and its related precursors like insulin resistance and the metabolic syndrome, requires terminal use of BMI, a biologically meaningless and crude indicator of obesity, in favor of effective and culturally competent non-relative body composition evaluation of genetically determined adiposity that untenably compares values among groups. African Americans are among the increasingly affected groups for diabetes and posses unique composition variation requiring proper intra-cultural evaluation independent of inter-ethnic Eurocentric assumptions that over assesses obesity risk. Incorporating use of 4C models to evaluate adiposity and assess risk for diabetic predisposition and onset provides an effective unbiased assessment of the cultural components inherent within body composition variation among ethnicity, age, gender. Obesity and type II diabetes onset and pre-disposition is assessed phenotypically, in creation of a body mass profile among African and African American groups, using 4C model, photography, anthropometry, somatotype and genetic evaluation. Environmental obeseogenic cultural factors are also explored
Food Preferences Survey in African Americans and West Africans: A Cultural Exploration of Agreement and Divergence in Attitudes in Food Environments and Food Responses
African Americans, currently over-represented among low SES groups, have been found to be among the most at risk groups for obesity and type 2 diabetes. Phenotypic expression, such as obesity, result from the combined effect of genetic inheritance and environmental influences. Environmental dynamics interact with individuals on micro, meso and ecto levels (Bronfrenbrenner, 1989), are diverse and cultural (Vygotsky, 1993) and are learned by individuals through modeling and observation (Bandura, 1989). Environmental factors such as parental influence and modeling, availability and accessibility of produce, sweetened drinks and fast foods, can contribute to or minimize the onset of obesity and type 2 diabetes. Consumption of fruits, vegetables and water has been shown to militate against the onset of obesity and type 2 diabetes. In the study āGenetic Bottlenecks Impacting Genes Governing Food Responses in African Americansā the author considers the genetic and environmental responses to the onset of obesity and Type II diabetes among African Americans. The author uses a culturally competent model for repeated traits *(P=Ī¼+G+Ep+Et) to evaluate the genotype/phenotype of African Americans. This model incorporates the contribution of temporary and permanent cultural environmental factors of historical origin, related to food responses, predisposition, metabolism and ethnic adjusted mean values of physical assessment to examine if the environment/genotype variables are informative towards the type 2 diabetes expression among African Americans, and to assess the validity of BMI as a predictor of adiposity and/or obesity prevalence among non-European populations. The main goal was to evaluate the relationship between BMI, fat distribution/prediction, variation among phenotypes and assess their relationships to the obesity genotype and environmental influences affecting metabolism and food choice
Wavelength-swept Tm-doped fiber laser operating in the two-micron wavelength band
A wavelength-swept thulium-doped silica fiber laser using an intracavity rotating slotted-disk wavelength scanning filter in combination with an intracavity solid etalon for passive control of temporal and spectral profiles is reported. The laser yielded a wavelength swept output in a step-wise fashion with each laser pulse separated from the previous pulse by a frequency interval equal to the free-spectral-range of the etalon and with an instantaneous linewidth of <0.05 nm. Scanning ranges from 1905 nm to 2049 nm for a cladding-pumping laser configuration, and from 1768 nm to 1956 nm for a core-pumping laser configuration were achieved at average output powers up to ~1 W
Soft-tissue abnormalities associated with treatment-resistant and treatment-responsive clubfoot: Findings of MRI analysis
BACKGROUND: Clubfoot treatment commonly fails and often results in impaired quality of life. An understanding of the soft-tissue abnormalities associated with both treatment-responsive and treatment-resistant clubfoot is important to improving the diagnosis of clubfoot, the prognosis for patients, and treatment. METHODS: Twenty patients with clubfoot treated with the Ponseti method were recruited for magnetic resonance imaging (MRI) of their lower extremities. Among these were seven patients (six unilateral cases) with treatment-responsive clubfoot and thirteen patients (five unilateral cases) with treatment-resistant clubfoot. Demographic information and physical examination findings were recorded. A descriptive analysis of the soft-tissue abnormalities was performed for both patient cohorts. For the patients with unilateral clubfoot, we calculated the percentage difference in cross-sectional area between the affected limb and the unaffected limb in terms of muscle, subcutaneous fat, intracompartment fat, and total area. With use of the Wilcoxon signed-rank test, we compared inter-leg differences in cross-sectional areas and the intracompartment adiposity index (IAI) between treatment-responsive and treatment-resistant groups. The IAI characterizes the cross-sectional area of fat within a muscle compartment. RESULTS: Extensive soft-tissue abnormalities were more present in patients with treatment-resistant clubfoot than in patients with treatment-responsive clubfoot. Treatment-resistant clubfoot abnormalities included excess epimysial fat and intramuscular fat replacement as well as unique patterns of hypoplasia in specific muscle groups that were present within a subset of patients. Among the unilateral cases, treatment-resistant clubfoot was associated with a significantly greater difference in muscle area between the affected and unaffected limb (ā47.8%) compared with treatment-responsive clubfoot (ā26.6%) (p = 0.02), a significantly greater difference in intracompartment fat area between the affected and unaffected limb (402.6%) compared with treatment-responsive clubfoot (9%) (p = 0.01), and a corresponding higher inter-leg IAI ratio (8.7) compared with treatment-responsive clubfoot (1.5) (p = 0.01). CONCLUSIONS: MRI demonstrated a range of soft-tissue abnormalities in patients, including unique patterns of specific muscle-compartment aplasia/hypoplasia that were present in patients with treatment-resistant clubfoot and not present in patients with treatment-responsive clubfoot. Correlations between MRI, physical examination, and treatment responsiveness may aid in the development of a prognostic classification system for clubfoot. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence
Effect of COD: SO42- Ratio, HRT and Linoleic Acid Concentration on Mesophilic Sulfate Reduction: Reactor Performance and Microbial Population Dynamics
Biological sulfate (SO42-) reduction was examined in anaerobic sequential batch reactors (ASBRs) operated under different hydraulic retention times (HRTs) ranging from 12 to 36 h and COD (Chemical Oxygen Demand)/SO42- ratios of 2.4, 1.6 and 0.8. Competition between SO42- reducing bacteria (SRBs), methane producing archaea (MPAs) and homoacetogens (HACs) was examined in controls and cultures treated with linoleic acid (LA). The ASBR performance was influenced by the COD/SO42- ratio in control cultures with a SO42- reduction of 87% at a COD/SO42- ratio of 0.8. At a 12 h HRT, in both control and LA treated cultures, greater than 75% SO42- removal was observed under all the conditions examined. In control reactors operating at a 36 h HRT, high levels of MPAs belonging to Methanobacteriales and Methanosarcinales were detected; however, in comparison, under low COD/SO42- ratio and with decreasing HRT conditions, a relative increase in SRBs belonging to Desulfovibrio and Desulfatibacillum was observed. Adding 0.5 gL(-1) LA suppressed Methanobacteriales, while increasing the LA concentration to 1 gL(-1) completely suppressed MPAs with a relative increase in SRBs. HACs belonging to Bacteroidetes were observed in the control and in cultures operated at 12 h HRT with a COD/SO42- ratio of 1.6 and fed 0.5 gL(-1) LA; however, with all other LA levels (0.5 and 1.0 gL(-1)) and HRTs (12, 24 and 36 h), HACs were not detected
Direct and Legacy Effects of Long-Term Elevated CO2 on Fine Root Growth and Plant-Insect Interactions
Increasing atmospheric CO2 concentrations alter leaf physiology, with effects that cascade to communities and ecosystems. Yet, responses over cycles of disturbance and recovery are not well known, because most experiments span limited ecological time. We examined the effects of CO2 on root growth, herbivory and arthropod biodiversity in a woodland from 1996 to 2006, and the legacy of CO2 enrichment on these processes during the year after the CO2 treatment ceased. We used minirhizotrons to study root growth, leaf censuses to study herbivory and pitfall traps to determine the effects of elevated CO2 on arthropod biodiversity. Elevated CO2 increased fine root biomass, but decreased foliar nitrogen and herbivory on all plant species. Insect biodiversity was unchanged in elevated CO2. Legacy effects of elevated CO2 disappeared quickly as fine root growth, foliar nitrogen and herbivory levels recovered in the next growing season following the cessation of elevated CO2. Although the effects of elevated CO2 cascade through plants to herbivores, they do not reach other trophic levels, and biodiversity remains unchanged. The legacy of 10yr of elevated CO2 on plant-herbivore interactions in this system appear to be minimal, indicating that the effects of elevated CO2 may not accumulate over cycles of disturbance and recovery
Circular Dichroism in Atomic Resonance-Enhanced Few-Photon Ionization
We investigate few-photon ionization of lithium atoms prepared in the polarized 2p(mā = +1) state when subjected to femtosecond light pulses with left- or right-handed circular polarization at wavelengths between 665 and 920 nm. We consider whether ionization proceeds more favorably for the electric field co- or counter-rotating with the initial electronic current density. Strong asymmetries are found and quantitatively analyzed in terms of circular dichroism (CD). While the intensity dependence of the measured CD values is rather weak throughout the investigated regime, a very strong sensitivity on the center wavelength of the incoming radiation is observed. While the co-rotating situation overall prevails, the counter-rotating geometry is strongly favored around 800 nm due to the 2p-3s resonant transition, which can only be driven by counter-rotating fields. The observed features provide insights into the helicity dependence of light-atom interactions, and on the possible control of electron emission in atomic few-photon ionization by polarization-selective resonance enhancement
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