A Fluidic Drive System for Intra-Aortic Balloon Heart Assist Device

Intra-aortic balloon pumping is a counter pulsation technique for temporary circulatory assistance in cardiogenic shock and other low cardiac output conditions. Conventional systems use a balloon at the end of a catheter driven by a solenoid valve, controlled by patient's ECG or ventricular pressure signal. This results in time delay introducted by solenoid spool inertia, gas inertia, and hysteresis effects of the solenoid. Fluidics, because of their non-moving part operation and high switching speeds, minimizes the inertial effects while contributing high reliability. This communication describes a fluidic system developed for driving the balloon accepting electric control signals.

Seismic Stability and Liquefaction Analysis of Tailings Dam

Proper analysis for safe design of tailings earthen dam is necessary under static loading and more so under earthquake conditions to reduce damages of important geotechnical structure. This paper presents both static and seismic analyses of a typical section of tailings earthen dam constructed by downstream method and located at a site in eastern part India to store non-radioactive nuclear waste material. The entire analysis is performed using geotechnical softwares FLAC(3D) and TALREN 4. Results are obtained for various possible conditions of the reservoir to investigate the stability under both static and seismic loading condition using 1989 Loma Prieta earthquake acceleration-time history. FLAC(3D) analyses indicate the critical maximum displacement at crest of the proposed tailings dam section is 5.5 cm under the static loading but it increases to about 16.24 cm under seismic loading. The slope stability analyses provide the minimum value of factor of safety for seismic loading as 1.5 as compared to 2.31 for static loading. Amplification of base seismic acceleration is also observed. The liquefaction potential analysis in FLAC(3D) indicates considerable loss of shear strength in the tailings portion of the proposed earthen dam section with significantly high values of pore pressure ratio.

Pseudo-Static and Pseudo-Dynamic Stability Analysis of Tailings Dam Under Seismic Conditions

In this paper the seismic slope stability analyses are performed for a typical section of 44 m high water retention type tailings earthen dam located in the eastern part of India, using both the conventional pseudo-static and recent pseudo-dynamic methods. The tailings earthen dam is analyzed for different upstream conditions of reservoir like filled up with compacted and non-compacted dumped waste materials with different water levels of the pond tailings portion. Phreatic surface is generated using seepage analysis in geotechnical software SEEP/W and that same is used in the pseudo-static and pseudo-dynamic analyses to make the approach more realistic. The minimum values of factor of safety using pseudo-static and pseudo-dynamic method are obtained as 1.18 and 1.09 respectively for the chosen seismic zone in India. These values of factor of safety show clearly the demerits of conventional pseudo-static analysis compared to recent pseudo-dynamic analysis, where in addition to the seismic accelerations, duration, frequency of earthquake, body waves traveling during earthquake and amplification effects are considered.

Multiple Spectral Peak Tracking for Heart Rate Monitoring from Photoplethysmography Signal During Intensive Physical Exercise

We propose a multiple initialization based spectral peak tracking (MISPT) technique for heart rate monitoring from photoplethysmography (PPG) signal. MISPT is applied on the PPG signal after removing the motion artifact using an adaptive noise cancellation filter. MISPT yields several estimates of the heart rate trajectory from the spectrogram of the denoised PPG signal which are finally combined using a novel measure called trajectory strength. Multiple initializations help in correcting erroneous heart rate trajectories unlike the typical SPT which uses only single initialization. Experiments on the PPG data from 12 subjects recorded during intensive physical exercise show that the MISPT based heart rate monitoring indeed yields a better heart rate estimate compared to the SPT with single initialization. On the 12 datasets MISPT results in an average absolute error of 1.11 BPM which is lower than 1.28 BPM obtained by the state-of-the-art online heart rate monitoring algorithm.

Evaluación de cinco fungicidas para el manejo de enfermedades foliares y su rentabilidad en el cultivo de tomate (Lycopersicom esculentum mill) c.v. butte, Sébaco, Matagalpa, Nicaragua

El presente trabajo se realizó en la Finca Surco Muerto, Municipio de Sébaco–Matagalpa en el período comprendido de Julio a octubre del 2004, con la finalidad de evaluar diferentes productos fungicidas sistémicos (Phyton 0.5 L. ha-1, Benomil 0.5 kg ha-1 y Curzate 2 kg ha-1) y preventivos (Mancozeb 2 kg ha-1 y Clorotalonil 2 L. ha-1) en el manejo de enfermedades foliares en tomate. El diseño establecido fué el de Bloques Completos al Azar (BCA),con siete tratamientos y cuatro repeticiones. Los resultados indican que el efecto de los tratamientos evaluados sobre el control de Alternaria solani enlas primeras fechas no demuestran diferencia estadística, hasta los 62 días después del trasplante (ddt), donde Clorotalonil se comportó como el mejor tratamiento en protección al follaje.Para la variable severidad de Xanthomonas campestris en follaje los resultados indican, que es a partir de los 78 ddt donde los tratamientos demuestran diferencia estadística, comportándose Phyton como el mejor tratamiento para el manejo de dicha enfermedad.El cultivo también fué fuerte mente afectado por Mosca blanca(Bemisia tabaciGenn.) lo que repercutió en porcentajes de severidad de virosis muy altos(92%),enmascarando un mejor efecto que pudieron haber tenido los tratamientos evaluados. Enrelación a las variables de rendimiento analizadas por contrastes ortogonales, para la variable peso de frutos buenos, el análisis no encontró diferencias estadísticas entre los grupos evaluados.Para la variable peso de frutos afectados por Alternaria el análisis detectó diferencias estadísticas entre los grupos evaluados donde el grupo de los Preventivos (Clorotalonil y Mancozeb) ejercieron mejor control para dicho patógeno por haberse obtenido con ellos los más bajos rendimientos afectados con 40.85 kg ha-1. En la variable peso de frutos afectados por Xanthomonas Campestris pvvesicatoria el análisis no encontró diferencias estadísticas entre los grupos comparados.Para el rendimiento real el análisis encontró diferencias estadísticas, donde demuestra que son los tratamientos preventivos (Mancozeb y Clorotalonil) los que ejercieron el mejor control con el más alto rendimiento 5658.56 kg ha-1.Los resultados del análisis económico indican que el tratamiento rentable es Mancozeb, por obtenerse con el una tasa de retorno marginal de 960.25%. En condiciones de bajo rendimiento es Alternado (Curzate + Clorotalonil +Mancozeb) el tratamiento rentable por obtenerse con el una TRM de 246.95%. Al realizar el análisis de sensibilidad los resultados demuestran que la aplicación de Mancozeb es justificable; aun cuando el precio del tomate disminuye en un 70%, de su precio original,ya que con precios bajos se obtiene una TRM de 1.98%.

Emergency dam at Pedro Miguel, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

The Heart is a Lonely Hunter: Un paradigma de transferencia cultural y literaria

Santamaría, José Miguel; Pajares, Eterio; Olsen, Vickie; Merino, Raquel; Eguíluz, Federico (eds.)

"The Heart is a Lonely Hunter": De lo literario a lo cinematográfico, de 1938 a 1968, del pesimismo de la Gran Depresión a la vanalización sentimentalista del movimiento hippy

Eterio Pajares, Raquel Merino y José Miguel Santamaría (eds.)

Experimental and finite element studies of a large arch dam

Forced vibration field tests and finite element studies have been conducted on Morrow Point (arch) Dam in order to investigate dynamic dam-water interaction and water compressibility. Design of the data acquisition system incorporates several special features to retrieve both amplitude and phase of the response in a low signal to noise environment. These features contributed to the success of the experimental program which, for the first time, produced field evidence of water compressibility; this effect seems to play a significant role only in the symmetric response of Morrow Point Dam in the frequency range examined. In the accompanying analysis, frequency response curves for measured accelerations and water pressures as well as their resonating shapes are compared to predictions from the current state-of-the-art finite element model for which water compressibility is both included and neglected. Calibration of the numerical model employs the antisymmetric response data since they are only slightly affected by water compressibility, and, after calibration, good agreement to the data is obtained whether or not water compressibility is included. In the effort to reproduce the symmetric response data, on which water compressibility has a significant influence, the calibrated model shows better correlation when water compressibility is included, but the agreement is still inadequate. Similar results occur using data obtained previously by others at a low water level. A successful isolation of the fundamental water resonance from the experimental data shows significantly different features from those of the numerical water model, indicating possible inaccuracy in the assumed geometry and/or boundary conditions for the reservoir. However, the investigation does suggest possible directions in which the numerical model can be improved.

Survey of fungal infestation of some fish species from Tagwai dam, Minna, Niger State

Survey of Fungal infestation of some species of fish in Tagwai Dam Minna was carried out from March to June 2002. Fungi were isolated from the scale/skin, gills and fins. Twenty-one fungi species were identified from 18 species of fish microbial growth was measured by direct cell count using Stuart colony counter. Most of the fungi encountered were of the mould group and infestation occurred among all the species sampled. The infestation was predominantly by Aspergillus species and the scale/skin was most widely affected. The study showed the identified fungi in order of frequency to be as follows. Aspergillius niger. Rrhizopus spp. Mmucor spp Aspergilus flavum. Aspergillus parasitous. Aspergillus fumigatus, Microsporum canis. Penicillum virridicalumand Fusarium spp respectively. Aspergillus niger occurred on all the species of fish sampled. Barrilius spa and Chrysichrhy auratus longifilis had significantly higher (P<0.05) mean fungal load on their fins and gills. There was no significant difference (P>0.05) in the mean fungal load in different parts of the body of other fish species sampled

Tissue engineering active biological machines : bio-inspired design, directed self-assembly, and characterization of muscular pumps simulating the embryonic heart

Biological machines are active devices that are comprised of cells and other biological components. These functional devices are best suited for physiological environments that support cellular function and survival. Biological machines have the potential to revolutionize the engineering of biomedical devices intended for implantation, where the human body can provide the required physiological environment. For engineering such cell-based machines, bio-inspired design can serve as a guiding platform as it provides functionally proven designs that are attainable by living cells. In the present work, a systematic approach was used to tissue engineer one such machine by exclusively using biological building blocks and by employing a bio-inspired design. Valveless impedance pumps were constructed based on the working principles of the embryonic vertebrate heart and by using cells and tissue derived from rats. The function of these tissue-engineered muscular pumps was characterized by exploring their spatiotemporal and flow behavior in order to better understand the capabilities and limitations of cells when used as the engines of biological machines.