1,352 research outputs found
Loss of heterozygosity on chromosome 5q in ovarian cancer is frequently accompanied by TP53 mutation and identifies a tumour suppressor gene locus at 5q13.1-21.
Forty-nine ovarian tumours were examined for loss of heterozygosity (LOH) on chromosome 5 using eight microsatellite markers spanning both arms, including one at the APC locus. LOH on 5q was a frequent event, detectable in 23 of 49 (47%) tumours, whereas 5p LOH was detected in only 1 of 22 tumours (5%). Six tumours showed partial LOH on 5q, enabling the candidate region to be localised to a 22 cM region proximal to APC, flanked by D5S424 and D5S644. An association was found between 5q LOH and TP53 mutation, with 18 of 23 (78%) tumours with LOH on 5q also harbouring a TP53 mutation. LOH on 5q was observed in 6 of 18 (33%) stage I tumours, suggesting that it may be an early event in the molecular pathogenesis of certain ovarian carcinomas
Qualitative characterization of healthcare wastes
The biological hazard inherent in the clinical wastes should be considered during the management and treatment process as well as the disposal into the environment. In this chapter, the risks associated with the clinical wastes as well as the management of these wastes are discussed. The chapter focused on reviewing the types of healthcare wastes generated from hospitals and clinics as well as the regulations and management practices used for these wastes. Moreover, the health risk associated with the infectious agents which have the potential to be transmitted into the environment. It has appeared that the clinical wastes represent real hazards for the human health and the environment if they were not managed properly
Gamma Ray Bursts: Observations and Theoretical Conjectures
Gamma Ray Bursts (GRBs) are short bursts of very high energy photons which were discovered in the late 1960s. Ever since their discovery, scientists have wondered about their origin. Nowadays it is known that they originate outside the Milky Way because of their high red shift rst measured in the afterglows thanks to the Beppo-SAX satellite and ground-based observations. However, theoreticians still do not agree about the mechanism that generates the bursts, and different competing models are animatedly debated. Current GRB experiments include the Swift satellite and the Pierre Auger Observatory that could detect GRBs with an increase of the background. A forthcoming dedicated experiment is GLAST, a satellite observatory for detecting gamma rays with energies up to 300 GeV, whose launch is scheduled for early 2008
Testbeam and Laboratory Characterization of CMS 3D Pixel Sensors
The pixel detector is the innermost tracking device in CMS, reconstructing
interaction vertices and charged particle trajectories. The sensors located in
the innermost layers of the pixel detector must be upgraded for the ten-fold
increase in luminosity expected with the High- Luminosity LHC (HL-LHC) phase.
As a possible replacement for planar sensors, 3D silicon technology is under
consideration due to its good performance after high radiation fluence. In this
paper, we report on pre- and post- irradiation measurements for CMS 3D pixel
sensors with different electrode configurations. The effects of irradiation on
electrical properties, charge collection efficiency, and position resolution of
3D sensors are discussed. Measurements of various test structures for
monitoring the fabrication process and studying the bulk and surface
properties, such as MOS capacitors, planar and gate-controlled diodes are also
presented.Comment: 14 page
Light-limited photosynthesis under energy-saving film decreases eggplant yield
Glasshouse films with adjustable light transmittance and energy-efficient designs have the potential to reduce (up to 80%) the high energy cost for greenhouse horticulture operations. Whether these films compromise the quantity and quality of light transmission for photosynthesis and crop yield remains unclear. A âSmart Glassâ film ULR-80 (SG) was applied to a high-tech greenhouse horticulture facility, and two experimental trials were conducted by growing eggplant (Solanum melongena) using commercial vertical cultivation and management practices. SG blocked 85% of ultraviolet (UV), 58% of far-red, and 26% of red light, leading to an overall reduction of 19% in photosynthetically active radiation (PAR, 380â699ĂÂ nm) and a 25% reduction in total season fruit yield. There was a 53% (season mean) reduction in net short-wave radiation (radiometer range, 385â2,105ĂÂ nm upward; 295â2,685ĂÂ nm downward) that generated a net reduction of 8% in heat load and reduced water and nutrient consumption by 18%, leading to improved energy and resource use efficiency. Eggplant adjusted to the altered SG light environment via decreased maximum light-saturated photosynthetic rates (Amax) and lower xanthophyll de-epoxidation state. The shift in light characteristics under SG led to reduced photosynthesis, which may have reduced source (leaf) to sink (fruit) carbon distribution, increased fruit abortion and decreased fruit yield, but did not affect nutritional quality. We conclude that SG increases energy and resource use efficiency, without affecting fruit quality, but the reduction in photosynthesis and eggplant yield is high. The solution is to re-engineer the SG to increase penetration of UV and PAR, while maintaining blockage of glasshouse heat gain
Deficiency in origin licensing proteins impairs cilia formation: implications for the aetiology of meier-gorlin syndrome
Mutations in ORC1, ORC4, ORC6, CDT1, and CDC6, which encode proteins required for DNA replication origin licensing, cause Meier-Gorlin syndrome (MGS), a disorder conferring microcephaly, primordial dwarfism, underdeveloped ears, and skeletal abnormalities. Mutations in ATR, which also functions during replication, can cause Seckel syndrome, a clinically related disorder. These findings suggest that impaired DNA replication could underlie the developmental defects characteristic of these disorders. Here, we show that although origin licensing capacity is impaired in all patient cells with mutations in origin licensing component proteins, this does not correlate with the rate of progression through S phase. Thus, the replicative capacity in MGS patient cells does not correlate with clinical manifestation. However, ORC1-deficient cells from MGS patients and siRNA-mediated depletion of origin licensing proteins also have impaired centrosome and centriole copy number. As a novel and unexpected finding, we show that they also display a striking defect in the rate of formation of primary cilia. We demonstrate that this impacts sonic hedgehog signalling in ORC1-deficient primary fibroblasts. Additionally, reduced growth factor-dependent signaling via primary cilia affects the kinetics of cell cycle progression following cell cycle exit and re-entry, highlighting an unexpected mechanism whereby origin licensing components can influence cell cycle progression. Finally, using a cell-based model, we show that defects in cilia function impair chondroinduction. Our findings raise the possibility that a reduced efficiency in forming cilia could contribute to the clinical features of MGS, particularly the bone development abnormalities, and could provide a new dimension for considering developmental impacts of licensing deficiency
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A Search for Dark Higgs Bosons
Recent astrophysical and terrestrial experiments have motivated the proposal
of a dark sector with GeV-scale gauge boson force carriers and new Higgs
bosons. We present a search for a dark Higgs boson using 516 fb-1 of data
collected with the BABAR detector. We do not observe a significant signal and
we set 90% confidence level upper limits on the product of the Standard
Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots
for b/w printin
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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