Crime, Mass Media and the General Public in Lithuania

The project investigated the presentation of crime in the Lithuanian media and its possible impact on the general public's understanding of crime-related problems in society. Dobryninas concentrated on three main aspects of this problem: the development of the image of crime in the Lithuanian press and television, journalists' principles in presenting crime-related information, and the public attitude to the presentation of crime in the media. A content analysis of national newspapers from the period of 1992-1997 showed not only increasing interest in crime problems, but also the distorted nature of the image of crime in the media. In-depth interviews with Lithuanian journalists demonstrated that they understood their role in presenting crime-related information firstly as providing information oriented to high public demand, although at the same time they did not deny the commercial and entertainment aspects of crime reporting. Readership and audience research illustrated the clear influence of the media on the public understanding of crime problems in society. However, the virtual image of crime did not greatly affect the system of values and beliefs of Lithuanians, nor did it challenge their insistence that problems of crime could and should be managed within the framework of a civil and open society.

Effects of low abdominal blood flow and dobutamine on blood flow distribution and on the hepatic arterial buffer response in anaesthetized pigs

Low cardiac output impairs the hepatic arterial buffer response (HABR). Whether this is due to low abdominal blood flow per se is not known. Dobutamine is commonly used to increase cardiac output, and it may further modify hepatosplanchnic and renal vasoregulation. We assessed the effects of isolated abdominal aortic blood flow changes and dobutamine on hepatosplanchnic and renal blood flow. Twenty-five anesthetized pigs with an abdominal aorto-aortic shunt were randomized to 2 control groups [zero (n = 6) and minimal (n = 6) shunt flow], and 2 groups with 50% reduction of abdominal blood flow and either subsequent increased abdominal blood flow by shunt reduction (n = 6) or dobutamine infusion at 5 and 10 microg kg(-1) min(-1) with constant shunt flow (n = 7). Regional (ultrasound) and local (laser Doppler) intra-abdominal blood flows were measured. The HABR was assessed during acute portal vein occlusion. Sustained low abdominal blood flow, by means of shunt activation, decreased liver, gut, and kidney blood flow similarly and reduced local microcirculatory blood flow in the jejunum. Shunt flow reduction partially restored regional blood flows but not jejunal microcirculatory blood flow. Low-but not high-dose dobutamine increased gut and celiac trunk flow whereas hepatic artery and renal blood flows remained unchanged. Neither intervention altered local blood flows. The HABR was not abolished during sustained low abdominal blood flow despite substantially reduced hepatic arterial blood flow and was not modified by dobutamine. Low-but not high-dose dobutamine redistributes blood flow toward the gut and celiac trunk. The jejunal microcirculatory flow, once impaired, is difficult to restore.

Thermodilution and esophageal Doppler ultrasound in the assessment of blood flow changes induced by endotoxin and dobutamine

BACKGROUND: Intermittent (IT) and continuous (CT) thermodilution and esophageal Doppler (ED), are all used for hemodynamic monitoring. The aim of this study was to test the agreement between these methods during endotoxin (ET) and dobutamine infusion. METHODS: Twenty-two pigs (39 +/- 1.8 kg body weight) were randomized to general anesthesia and either continuous ET (n = 9) or placebo (PL, n = 13) infusion. After 18 hours of ET or PL infusion, the animals were further randomized to receive dobutamine (n = 3 in ET, n = 5 in PL) or PL. A set of measurements using the three methods were obtained every hour, and the relative blood flow changes between two subsequent measurements were calculated. RESULTS: Bias or limits of agreement for flows were 0.73 L/min or 1.80 L/min for IT and CT, -0.33 L/min or 4.29 L/min for IT and ED, and -1.06 or 3.94 for CT and ED (n = 515, each). For flow changes they were 1% or 44%, 2% or 59%, and 3% or 45%, respectively. Bias and limits of agreement did not differ in ET- and PL-treated animals or in animals with or without dobutamine. Despite significant correlation between any two methods, the respective correlation coefficients (r) were small (IT vs. CT: 0.452; IT vs. ED: 0.042; CT vs. ED: 0.069; all p < 0.001). The same directional changes were measured by any two methods in 49%, 40%, and 50%. When IT flows >5 L/min were compared with IT flows in, the latter had 49% (p < 0.001), 23% (p < 0.001), and 24% smaller limits of agreement than the former (p = 0.012). CONCLUSION: IT and CT cardiac output agree only to a moderate level, and agreement between the respective relative blood flow changes is even worse. ED has poor agreement with both thermodilution methods, especially when cardiac output is >5 L/min.

Bislug flow in circular and noncircular channels and the role of interface stretching on energy dissipation

The area of microfluidics has increased in popularity with such fields as MEMS, microreactors, microscaleheat exchangers, etc. A comprehensive understanding of dissipation mechanisms for fluid flow in microchannels is required to accurately predict the behavior in these small systems. Tests were performed using a constant pressure potential created by two immiscible fluids juxtaposed in a microchannel. This study focused on the flow and dissipation mechanisms in round and square microchannels. There are four major dissipation mechanisms in slug flow; wall shear, dissipation at the contact line, menisci interaction and the stretching of the interface. A force balance between the internal driving potential, viscous drag and interface stretching was used to develop a model for the prediction of the velocity of a bislug in a microchannel. Interface stretching is a dissipation mechanism that has been included due to the unique system properties and becomes increasingly more important as the bislug decreases in length.

Implementation of a phenomenological evaporation model into a porous network simulation for water management in low temperature fuel cells

A phenomenological transition film evaporation model was introduced to a pore network model with the consideration of pore radius, contact angle, non-isothermal interface temperature, microscale fluid flows and heat and mass transfers. This was achieved by modeling the transition film region of the menisci in each pore throughout the porous transport layer of a half-cell polymer electrolyte membrane (PEM) fuel cell. The model presented in this research is compared with the standard diffusive fuel cell modeling approach to evaporation and shown to surpass the conventional modeling approach in terms of predicting the evaporation rates in porous media. The current diffusive evaporation models used in many fuel cell transport models assumes a constant evaporation rate across the entire liquid-air interface. The transition film model was implemented into the pore network model to address this issue and create a pore size dependency on the evaporation rates. This is accomplished by evaluating the transition film evaporation rates determined by the kinetic model for every pore containing liquid water in the porous transport layer (PTL). The comparison of a transition film and diffusive evaporation model shows an increase in predicted evaporation rates for smaller pore sizes with the transition film model. This is an important parameter when considering the micro-scaled pore sizes seen in the PTL and becomes even more substantial when considering transport in fuel cells containing an MPL, or a large variance in pore size. Experimentation was performed to validate the transition film model by monitoring evaporation rates from a non-zero contact angle water droplet on a heated substrate. The substrate was a glass plate with a hydrophobic coating to reduce wettability. The tests were performed at a constant substrate temperature and relative humidity. The transition film model was able to accurately predict the drop volume as time elapsed. By implementing the transition film model to a pore network model the evaporation rates present in the PTL can be more accurately modeled. This improves the ability of a pore network model to predict the distribution of liquid water and ultimately the level of flooding exhibited in a PTL for various operating conditions.

Changes in blood flow velocity in the middle and anterior cerebral arteries evoked by walking

PURPOSE: Transcranial Doppler sonography (TCD) is an established method for assessing changes in blood flow velocity (BFV) coupled to brain activity. Our objective was to investigate whether walking induces measurable changes in BFV in healthy subjects. METHODS: Changes in BFV in both middle cerebral arteries (MCAs) of 40 healthy adult subjects during walking on a treadmill were measured using bilateral TCD. In 8 of the 40 subjects, 1 anterior cerebral artery (ACA) was monitored simultaneously with the contralateral MCA. The percentage increase in BFV (BFVI%) compared with the baseline velocity (V(0)), the percentage decrease in BFV (BFVD%) compared with the V(0), and the normalized ACA-MCA ratio were analyzed. RESULTS: The overall mean (+/- standard deviation [SD]) V(0) was 59.9 +/- 11.6 cm/second in the left MCA and 60.1 +/- 12.9 cm/second in the right MCA. Women had higher V(0) values than men had. Walking evoked an initial mean overall BFVI% in both left (8.4 +/- 5.1%) and right MCAs (9.1 +/- 5.1%), followed by a decrease to below baseline values in 38 of 40 subjects. A statistically significant increase of the normalized ACA-MCA ratio was measured, indicating that changes in BFV in the ACA territory were coupled to brain activation during walking. CONCLUSIONS: The use of functional TCD showed different changes in BFV in the ACAs and MCAs during walking. This method may be an interesting tool for monitoring progress in patients with motor deficits of the legs, such as paresis.