Bluegill sunfish use high power outputs from axial muscles to generate powerful suction-feeding strikes

Suction-feeding fish rapidly expand the mouth cavity to generate high-velocity fluid flows that accelerate food into the mouth. Such fast and forceful suction expansion poses a challenge, as muscle power is limited by muscle mass and the muscles in fish heads are relatively small. The largemouth bass powers expansion with its large body muscles, with negligible power produced by the head muscles (including the sternohyoideus). However, bluegill sunfish – with powerful strikes but different morphology and feeding behavior – may use a different balance of cranial and axial musculature to power feeding and different power outputs from these muscles. We estimated the power required for suction expansion in sunfish from measurements of intraoral pressure and rate of volume change, and measured muscle length and velocity. Unlike largemouth bass, the sternohyoideus did shorten to generate power, but it and other head muscles were too small to contribute more than 5–10% of peak expansion power in sunfish. We found no evidence of catapult-style power amplification. Instead, sunfish powered suction feeding by generating high power outputs (up to 438 W kg−1) from their axial muscles. These muscles shortened across the cranial half of the body as in bass, but at faster speeds that may be nearer the optimum for power production. Sunfish were able to generate strikes of the same absolute power as bass, but with 30–40% of the axial muscle mass. Thus, species may use the body and head muscles differently to meet the requirements of suction feeding, depending on their morphology and behavior

Tritium Reduction and Control in the Vacuum Vessel during TFTR Outage and Decommissioning

In the summer/fall of 1996 after nearly three years of D-T operations, TFTR underwent an extended outage during which large port covers were removed from the vacuum vessel in order to complete upgrades to the tokamak. Following the venting of the torus, a three tier system was developed for the outage in order to reduce and control the free tritium in the vacuum vessel so as to minimize the exposure to personnel during port cover removal and reinstallation. The first phase of the program to reduce the free tritium consisted of direct flowthrough of room air through the vacuum vessel to the molecular sieve beds using the Torus Cleanup System. Real time measurements of the effluent tritium concentration were used to derive the amount of tritium removed from the torus. Once the free tritium in the vessel had been reduced to approximately 50 Ci, a second phase was initiated using a 55 Gallon Drum Bubbler System for the direct processing of the vacuum vessel to further lower the tritium level in the torus. Tritium oxide is absorbed by the bubbler system with the exhaust vented to one of the tritium monitored HVAC ventilation stacks. To preclude the release of tritium to the Test Cell location of TFTR and to minimize the exposure of workers, a variable flow exhaust system was employed in order to maintain a negative pressure in the vacuum vessel between 0.05" and 1.5" w.c. during the removal of port covers ranging in size from approximately 5 to 1000 in(superscript2). These systems were completely successful in reducing and controlling the free tritium in TFTR and were instrumental in maintaining ALARA (As Low As Reasonably Achievable) exposures to tritium during the 1996 outage. These systems are again being utilized during the safe shutdown and decommissioning of TFTR which commenced in April of 1997. This paper describes in detail the configuration of these systems and the data obtained during the outage and safe shutdown of TFTR

Determination of 35 cell surface antigen levels in malignant pleural effusions identifies CD24 as a marker of disseminated tumor cells

Many targets have been identified in solid tumors for antibody therapy but it is less clear what surface antigens may be most commonly expressed on disseminated tumor cells. Using malignant pleural effusions as a source of disseminated tumor cells, we compared a panel of 35 antigens for their cancer specificity, antigen abundance and functional significance. These antigens have been previously implicated in cancer metastasis and fall into four categories: (i) cancer stem cell, (ii) epithelial-mesenchymal transition, (iii) metastatic signature of in vivo selection and (iv) tyrosine kinase receptors. We determined the antigen density of all 35 antigens on the cell surface by flow cytometry, which ranges from 3 × 10[superscript 3]–7 × 10[superscript 6] copies per cell. Comparison between the malignant and benign pleural effusions enabled us to determine the antigens specific for cancer. We further chose six antigens and examined the correlation between their expression levels and tumor formation in immunocompromised mice. We concluded that CD24 is one of the few antigens that could simultaneously meet all three criteria of an ideal target. It was specifically and abundantly expressed in malignant pleural effusions; CD24[superscript high] tumor cells formed tumors in mice at a faster rate than CD24[superscript low] tumor cells, and shRNA-mediated knockdown of CD24 in HT29 cells confirmed a functional requirement for CD24 in the colonization of the lung. Concomitant consideration of antigen abundance, specificity and functional importance can help identify potentially useful markers for disseminated tumor cells

Crustal structure of the Arabian Plate: New constraints from the analysis of teleseismic receiver functions

An edited version of this paper was published by Elsevier Science. Copyright 2005, Elsevier Science. See also: http://dx.doi.org/10.1016/j.epsl.2004.12.020; http://atlas.geo.cornell.edu/SaudiArabia/publications/Al-Damegh%202005.htmReceiver functions for numerous teleseismic earthquakes recorded at 23 broadband and mid-band stations in Saudi Arabia and Jordan were analyzed to map crustal thickness within and around the Arabian plate. We used spectral division as well as time domain deconvolution to compute the individual receiver functions and receiver function stacks. The receiver functions were then stacked using the slant stacking approach to estimate Moho depths and Vp/Vs for each station. The errors in the slant stacking were estimated using a bootstrap re-sampling technique. We also employed a grid search waveform modeling technique to estimate the crustal velocity structure for seven stations. A jackknife re-sampling approach was used to estimate errors in the grid search results for three stations. In addition to our results, we have also included published receiver function results from two temporary networks in the Arabian shield and Oman as well as three permanent GSN stations in the region. The average crustal thickness of the late Proterozoic Arabian shield is 39 km. The crust thins to about 23 km along the Red Sea coast and to about 25 km along the margin of the Gulf of Aqaba. In the northern part of the Arabian platform, the crust varies from 33 to 37 km thick. However, the crust is thicker (41?53 km) in the southeastern part of the platform. There is a dramatic change in crustal thickness between the topographic escarpment of the Arabian shield and the shorelines of the Red Sea. We compared our results in the Arabian shield to nine other Proterozoic and Archean shields that include reasonably well determined Moho depths, mostly based on receiver functions. The average crustal thickness for all shields is 39 km, while the average for Proterozoic shields is 40 km, and the average for Archean shields is 38 km. We found the crustal thickness of Proterozoic shields to vary between 33 and 44 km, while Archean shields vary between 32 and 47 km. Overall, we do not observe a significant difference between Proterozoic and Archean crustal thickness. We observed a dramatic change in crustal thickness along the Red Sea margin that occurs over a very short distance. We projected our results over a cross-section extending from the Red Sea ridge to the shield escarpment and contrasted it with a typical Atlantic margin. The transition from oceanic to continental crust of the Red Sea margin occurs over a distance of about 250 km, while the transition along a typical portion of the western Atlantic margin occurs at a distance of about 450 km. This important new observation highlights the abruptness of the breakup of Arabia. We argue that a preexisting zone of weakness coupled with anomalously hot upper mantle could have initiated and expedited the breakup

Pulmonary Sclerosing Hemangioma Detected by Fluorodeoxyglucose Positron Emission Tomography in Familial Adenomatous Polyposis: Report of a Case

We present a 53-year-old female suffering from familial adenomatous polyposis, who was found to have a positive nodus, lateral to the hilus of the left lung, on routine FDG-PET scan. This lesion was found to be a sclerosing hemangioma. We found an aberrant β-catenin expression on immunohistochemical staining, suggesting that sclerosing hemangioma and familial adenomatous polyposis share the same pathophysiology. It is important to be aware of the association of familial adenomatous polyposis and sclerosing hemangioma

Regional seismic wave propagation (Lg and Sn) and Pn attenuation in the Arabian Plate and surrounding regions

An edited version of this paper was published by Blackwell Publishing. Copyright 2004, Blackwell Publishing. See also: http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-246X.2004.02246.x; http://atlas.geo.cornell.edu/MiddleEastNorthAfrica/publications/Al-Damegh2004.htmContinuous recordings of 17 broadband and short period digital seismic stations from a newly established seismological network in Saudi Arabia, along with digital recordings from the broadband stations of the GSN, MEDNET, GEOFON, a temporary array in Saudi Arabia, and a temporary short period stations in Oman, were analyzed to study the lithospheric structure of the Arabian plate and surrounding regions. The Arabian plate is surrounded by a variety of types of plate boundaries: continental collision (Zagros belt and Bitlis suture), continental transform (Dead Sea fault system), young sea floor spreading (Red Sea and Gulf of Aden), and oceanic transform (Owen fracture zone). Also, there are many intraplate Cenozoic processes such as volcanic eruptions, faulting, and folding that are taking place. We used this massive waveform database of more than 6200 regional seismogram to map zones of blockage, inefficient, and efficient propagation of the Lg and Sn phases in the Middle East and East Africa. We observed Lg blockage across the Bitlis suture and Zagros fold and thrust belt, corresponding to the boundary between the Arabian and Eurasian plates. This is probably due to a major lateral change in the Lg crustal wave-guide. We also observed inefficient Lg propagation along the Oman mountains. Blockage and inefficient Sn propagation is observed along and for a considerable distance to the east of the Dead Sea fault system and in the northern portion of the Arabian plate (south of the Bitlis suture). These mapped zones of high Sn attenuation, moreover, closely coincide with extensive Neogene and Quaternary volcanic activity. We have also carefully mapped the boundaries of the Sn blockage within the Turkish and Iranian plateaus. Furthermore, we observed Sn blockage across the Owen fracture zone and across some segments of the Red Sea. These regions of high Sn attenuation most probably have anomalously hot and possibly thin lithospheric mantle (i.e., mantle lid). A surprising result is the efficient propagation of Sn across a segment of the Red Sea; an indication that active sea floor spreading is not continuous along the axis of the Red Sea. We also investigated the attenuation of Pn phase (QPn) for 1-2 Hz along the Red Sea, Dead Sea fault system, within the Arabian shield, and in the Arabian platform. Consistent with the Sn attenuation, we observed low QPn values of 22 and 15 along the western coast of the Arabian plate and along the Dead Sea fault system, respectively, for a frequency of 1.5 Hz. Higher QPn values on the order of 400 were observed within the Arabian shield and platform for the same frequency. Our results based on Sn and Pn observations along the western and northern portions of the Arabian plate imply the presence of a major anomalously hot and thinned lithosphere in these regions that may be caused by the extensive upper mantle anomaly that appears to span most of east Africa and western Arabia