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American business first invested in the Netherlands in 1891. The American Petroleum Company, a Dutch/Belgian/American joint venture in which Standard Oil of New Jersey was a shareholder, set up shop [...]

Evacuation modelling has traditionally been limited to prior analysis of the geometrical design of spaces. This approach is limited by the number of scenarios that can be tested. A scenario-independent evacuation model would rely on real-time information processing. This approach allows the generation of an optimum evacuation strategy that minimises evacuation time and crowd density, and is tailored to the current situation at hand. This paper describes the requirements and development of such a crowd model. Graph theory and network flow heuristics are combined with agent movement, based on the individual determination of speed by meso-scale density assessment.

The article reports on vegetarian canteens in schools in Germany. A vegetarian canteen offers a convincing number of positive aspects. The food industry has changed a lot in recent years. A few decades ago, meat was only available on special occasions, but today meat can be found everywhere. The price is also falling continuously, not least because the conditions under which the breeding animals are kept are often unreasonable.

AbstractThe second to fourth finger length ratio (2d:4d) has been the subject of much recent work and is thought to be related to diverse gender and hormone-related traits including sports ability, disease susceptibility, attractiveness and sexuality. It is established in uteroand remains constant in adulthood. Familial clustering has been thought to contribute to the development of 2d:4d from early studies but no twin studies exploring heritability have been reported to date. In this study, a sample of 456 female twin pairs (148 monozygotic [MZ], 308 dizygotic [DZ]) aged 18 to 79 years was used to estimate the heritability of 2d:4d for the right and left hands. Finger lengths were derived from hand xrays. Variance components analysis was used to estimate and contrast genetic and environmental effects on this phenotype. The mean 2d:4d was 0.92 (SD= 0.001) for both hands. The MZ intraclass correlation was higher than in DZ (.66 vs. .35 for right 2d:4d, and .71 vs. .37 for left 2d:4d). The best fit model included additive polygenic and unique environmental effects (?AE? model), with no significant common environmental effects detected. Heritability was estimated to be approximately 66% for 2d:4d (95% confidence interval 0.5?0.78). These results suggest a substantial genetic contribution to the determination of this hormonally related skeletal ratio in women, which could be more influential than the effects of common prenatal environmental factors. However the current study design does not preclude the possibility of confounding between heritability estimates and unobserved prenatal effects.

Effective antiretroviral therapy initially resulted in large decreases in hospitalization rates of HIV-infected patients. The goal of this study was to determine whether these gains were being maintained in 2001. A cross-sectional study of hospital admission characteristics during four time periods was performed. All patients receiving care at the HIV clinics of New York Presbyterian Hospital-Cornell Medical Center (NYPH) in New York City were included. In 1995, 883 outpatients were receiving care for HIV infection at NYPH; this increased to 1990 outpatients by 2001. Demographic and laboratory information was obtained for these outpatients, and diagnoses were recorded for all patients requiring hospitalization on at NYPH during the time periods January 1 through June 30, in 1995, 1997, 1999, and 2001. The incidence of hospital admission declined in all four time periods: 1995 (95 per 100 patient-years [pt-yr]), 1997 (48 per 100 pt-yr), 1999 (38 per 100 pt-yr, p < 0.05), and 2001 (25 per 100 pt-yr). The incidence of bacterial pneumonia and opportunistic infections (OIs) decreased in all four time periods. The median hospitalization were CD4+ cell count for outpatients increased from 231 (1995) to 364 (2001). Important predictors of hospitalization were CD4+ < 200, and IVDU as an HIV risk factor. Since 1995 and the introduction of highly active antiretroviral therapy, continuing increases in CD4+ cell counts of outpatients has been reflected in persistent declines in hospitalization rates. Large decreases in OIs and pneumonia have been minimally offset by stable rates of hospital admissions for diagnoses such as hepatitis, cirrhosis, and cellulitis.

ABSTRACTMycobacterium tuberculosishas a relatively high resistance to killing by hydrogen peroxide and organic peroxides. Resistance may be mediated by mycobacterial catalase-peroxidase (KatG) and possibly by alkyl hydroperoxide reductase (AhpC). To determine the interrelationship between sensitivity to H2O2, catalase and peroxidase activities, and bacillary growth rates measured both intracellularly in human monocytes and in culture medium, we examined one laboratory strain, two clinical isolates, and three recombinant strains of M. tuberculosiswith differing levels of KatG and AhpC. Five of the mycobacterial strains had intracellular doubling times of 27 to 32 h, while one KatG-deficient clinical isolate (ATCC 35825) doubled in ∼76 h. Killing of mycobacteria by exogenously added H2O2was more pronounced for intracellular bacilli than for those bacilli derived from disrupted monocytes. Strains with no detectable KatG expression or catalase activity were relatively sensitive to killing (43 to 67% killing) by exogenous H2O2. However, once even minimal catalase activity was present, mycobacterial catalase activity over a 10-fold range (0.56 to 6.2 U/mg) was associated with survival of 85% of the bacilli. Peroxidase activity levels correlated significantly with resistance of the mycobacterial strains to H2O2-mediated killing. An endogenous oxidative burst induction by 4β-phorbol 12β-myristate 13α-acetate treatment of infected monocytes reduced the viability of the KatG null strain (H37Rv Inhr) but not the KatG-overexpressing strain [H37Rv(pMH59)]. These results suggest that mycobacterial resistance to oxidative metabolites (including H2O2and other peroxides) may be an important mechanism of bacillary survival within the host phagocyte.

ABSTRACTDespite the antimicrobial mechanisms of vertebrate phagocytes, mycobacteria can survive within the phagosomes of these cells. These organisms use various strategies to evade destruction, including inhibition of acidification of the phagosome and inhibition of phagosome-lysosome fusion. In contrast to mycobacteria, Coxiella burnetii, the etiologic agent of Q fever, inhabits a spacious acidified intracellular vacuole which is prone to fusion with other vacuoles of the host cell, including phagosomes containing mycobacteria. The Coxiella-infected cell thus provides a unique model for investigating the survival of mycobacteria in an acidified phagosome-like compartment. In the present study, murine bone marrow-derived macrophages were infected with eitherMycobacterium aviumor Mycobacterium tuberculosisand then coinfected with C. burnetii. We observed that the majority of phagocytosed mycobacteria colocalized to the C. burnetii-containing vacuole, which maintained its acidic properties. In coinfected macrophages, the growth of M. aviumwas not impaired following fusion with the acidified vacuole. In contrast, the growth rate of M. tuberculosiswas reduced in acidified vacuoles. These results suggest that although both species of mycobacteria inhibit phagosome-lysosome fusion, they may be differentially susceptible to the toxic effects of the acidic environment in the mature phagolysosome.

We have explored the biological function of a surface glycoprotein (GP72) of Trypanosoma cruzi by studying a null mutant parasite, generated by targeted gene dele-tion. GP72 deletion affected parasite morphology in several stages of the life cycle. Insect midgut (epimastigote) forms had a detached flagellum (apomastigote) in the null mutant. The abnormal flagellar phenotype persisted during development of the infective (metacyclic) forms but there was no impairment in the aquisition of complement resistance, sialidase expression or cell infectivity. The GP72 null mutant could efficiently infect and proliferate in mouse macrophages and non-phagocytic L6E9 cells. The mammalian stages of the life cycle also showed major morphological abnormalities. During early subcultures in L6E9 cells, few extracellular fully flagellated forms, expressing markers characteristic of trypomastigotes, were seen. The extracellular popula-tion consisted almost exclusively of rounded forms with short flagella (micromastigote), which expressed an amastigote-specific surface marker and no sialidase. The propagation of the parasite was not affected, despite the apparent lack of the trypomastigote forms, which are thought to be primarily responsible for cell invasion. After some subcultures, the extracellular population changed to about equal numbers of micromastigotes and a range of flagellated forms that still did not include true trypomastigotes. Instead, the kinetoplast remained close to the nucleus and the flagellum emerged from the middle of the cell (mesomastigote). Half of the flagellum adhered to the cell body and the remainder was free at the anterior end. In Triatoma infestans, the survival of the mutant was dramatically reduced, suggesting that either GP72 itself, or the altered properties of the flagellum, were critical for establishment in the insect vector.

LEAD: MY RACE FOR the Democratic Presidential nomination took me to a close second place in Iowa, third in New Hampshire and Minnesota - and, apart from a healthy victory in my home state of Illinois, it went downhill from there. [ABSTRACT FROM PUBLISHER]

The relative virulence and avirulence of Mycobacterium tuberculosis strains H37Rv and H37Ra were previously defined using animal infection models. To investigate host species' specificity of mycobacterial virulence, growth of the 2 M. tuberculosis strains in human monocyte-derived macrophages in vitro was studied. Mycobacterial growth was evaluated by acid-fast staining, electron microscopy, and colony-forming units (cfu) assay. As expected, the 2 strains demonstrated significantly different growth rates in mouse macrophages in vitro (53 h for H37Rv, 370 h for H37Ra). In marked contrast, in human macrophages the average division times of the strains were nearly equal (80 h for H37Rv and 76 h for H37Ra by cfu measurement, and 96 h for H37Rv and 104 h for H37Ra by acid-fast staining). These findings indicate that observations of mycobacterial virulence in murine systems may not necessarily translate to the human system, in which different mechanisms to control mycobacterial growth may be expressed.