Vascular Plants on External Dumping Ground of Lignite Mine "Bełchatów"

The article contains presentation of results of the studies on the vascular flora in the external dumping ground of Lignite Mine "Bełchatów", which were carried out in the years 1979-1984. The flora includes 233 species with 46 species among them being planted or sown.Pracę wykonano w ramach problemu WE - 10. 2. 07. 03- 07. Geobotaniczne podstawy oceny i kształtowania środowiska na obszarach górnictwa węglowego

Optimization of circular orifice jets mixing into a heated cross flow in a cylindrical duct

To examine the mixing characteristics of circular jets in an axisymmetric can geometry, temperature measurements were obtained downstream of a row of cold jet injected into a heated cross stream. The objective was to obtain uniform mixing within one duct radius downstream of the leading edge of the jet orifices. An area weighted standard deviation of the mixture fraction was used to help quantify the degree of mixedness at a given plane. Non-reacting experiments were conducted to determine the influence of the number of jets on the mixedness in a cylindrical configuration. Results show that the number of orifices significantly impacts the mixing characteristics of jets injected from round hole orifices in a can geometry. Optimum mixing occurs when the mean jet trajectory aligns with the radius which divides the cross sectional area of the can into two equal parts at one mixer radius downstream of the leading edge of the orifice. The optimum number of holes at momentum-flux ratios of 25 and 52 is 10 and 15 respectively

Identifying Novel Triggers of the Intracellular Pathogen Response (IPR) in C. elegans

The intracellular pathogen response (IPR) is a cell signaling pathway found in C. elegans that is triggered when pathogenic microorganisms invade, and immune responses attempt to eliminate the threat. Due to the relative simplicity of C. elegans, they are an excellent model organism to analyze the cell signaling pathways triggered by various pathogens. They lack the complex immune systems of larger organisms, making it easier to study the involved cell signaling pathways. Past studies have shown that the IPR can also be triggered via intestinal wounding. Heat stress, viral infection, and proteasome stress are all known triggers of the IPR. The long-term goal of this project is to generate potential new triggers, the response of which will be compared to the response generated by known triggers. The IPR will be quantified by measuring nanoluciferase expression, which is driven by an IPR gene. The immediate goal of this project is to develop this nanoluciferase assay system to generate IPR activity data in a high-throughput fashion. We hope to eventually be able to relate our findings to similar pathways in humans and other vertebrates. While humans do not have the IPR that is found in C. elegans, they have similar pathways that perform equivalent functions. In particular, we are interested in how intestinal damage could be related to activation of innate immunity. This information could be used to gain a better understanding of gastrointestinal diseases, specifically inflammatory bowel diseases

27. Time factor in postoperative radiotherapy for squamous cell head and neck cancer; a multivariate locoregional control analysis in 942 patients

PurposeTo analyze the influence of overall radiation treatment time and duration of the interval surgery-radiotherapy on local tumor control (LTC) in postoperative radiotherapy (PRT) for squamous cell head and neck cancer (SCHNC).Material/methodsA multivariate Cox proportional hazard regression analysis included 942 patients with locally advanced SCHNC. Mean total radiation dose, dose per fraction, treatment time, and the interval surgery-PRT were 62,5 Gy, 2,1 Gy, 46 days, and 62 days respectively. No interruptions during PRT (except for weekend brakes) appeared in 29% of patients, while 28% had more than 5 days of gap. The data were grouped into seven categories depending on the position of gap (weeks 1–7).ResultsIncrease in treatment gaps, the presence of tumor recurrence after surgery, N stage, and extra-laryngeal site of cancer were significantly related to decrease in LTC. The duration of time interval surgery-PRT had only marginal significance for LTC. Other variables did not appear significant. Consideration of seven time intervals for treatment gaps in the multivariate model has shown a significant progressive increase in the hazard of recurrence for gaps in the respective weeks 1 to 7.ConclusionsThis analysis shows a detrimental effect of interruptions during PRT, and only marginal decrease in LTC from the extension of the interval surgery-PRT. Therefore it seems unjustified to rush with PRT at the expense of possible increase in radiation treatment gaps. However, excessive delays in initiating PRT should be avoided, since they may lead to a recurrence prior to irradiation

Conformational spread as a mechanism for cooperativity in the bacterial flagellar switch

The bacterial flagellar switch that controls the direction of flagellar rotation during chemotaxis has a highly cooperative response. This has previously been understood in terms of the classic two-state, concerted model of allosteric regulation. Here, we used high-resolution optical microscopy to observe switching of single motors and uncover the stochastic multistate nature of the switch. Our observations are in detailed quantitative agreement with a recent general model of allosteric cooperativity that exhibits conformational spread—the stochastic growth and shrinkage of domains of adjacent subunits sharing a particular conformational state. We expect that conformational spread will be important in explaining cooperativity in other large signaling complexes

Optimization of Orifice Geometry for Cross-Flow Mixing in a Cylindrical Duct

Mixing of gaseous jets in a cross-flow has significant applications in engineering, one example of which is the dilution zone of a gas turbine combustor. Despite years of study, the design of the jet injection in combustors is largely based on practical experience. The emergence of NO(x) regulations for stationary gas turbines and the anticipation of aero-engine regulations requires an improved understanding of jet mixing as new combustor concepts are introduced. For example, the success of the staged combustor to reduce the emission of NO(x) is almost entirely dependent upon the rapid and complete dilution of the rich zone products within the mixing section. It is these mixing challenges to which the present study is directed. A series of experiments was undertaken to delineate the optimal mixer orifice geometry. A cross-flow to core-flow momentum-flux ratio of 40 and a mass flow ratio of 2.5 were selected as representative of a conventional design. An experimental test matrix was designed around three variables: the number of orifices, the orifice length-to- width ratio, and the orifice angle. A regression analysis was performed on the data to arrive at an interpolating equation that predicted the mixing performance of orifice geometry combinations within the range of the test matrix parameters. Results indicate that the best mixing orifice geometry tested involves eight orifices with a long-to-short side aspect ratio of 3.5 at a twenty-three degree inclination from the center-line of the mixing section