5,921 research outputs found
Testing of Great Bay Oysters for Two Protozoan Pathogens
Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo) are known to be present in Great Bay oysters. With funds provided by the Piscataqua Region Estuaries Partnership (PREP), the Marine Fisheries Division of the New Hampshire Fish and Game Department (NHF&G) continues to assess the presence and intensity of both of these disease conditions in oysters from the major natural beds within the Great Bay estuarine system and at selected aquaculture sites. Histological examinations of Great Bay oysters have also revealed other endoparasites
Traumatic events, perceived stress, and health in women with fibromyalgia and healthy controls
This study examined the relationship between trauma, stress and health in 41 women with fibromyalgia (FM) and 44 women who were healthy controls (HC). The participants were assessed for traumatic events, perceived stress and mental and physical health. Perceived stress was related to worse mental and physical health in both groups. Traumatic events were related to worse mental and physical health in the FM group but were unrelated to health in the HC group. Perceived stress partially mediated the effect of traumatic events on mental and physical health in the FM group. Finally, adult abuse partially mediated the effects of child abuse on adult stress and health. Trauma may have lasting effects on stress and health in women with FM. Copyright © 2009 John Wiley & Sons, Ltd
The Role of Resilience and Purpose in Life in Habituation to Heat and Cold Pain
This study examined the role of resilience in habituation to heat and cold pain in healthy women (n = 47). Heat and cold pain thresholds were each assessed across 5 equally spaced trials. Re- silience, purpose in life, optimism, social support, and neuroticism were assessed using self-report measures. The hypothesis was that the resilience and the associated resilience factors would be pos- itively related to habituation to heat and cold pain while controlling for neuroticism. Multilevel mod- eling was used to test the hypothesis. When considering each characteristic separately, resilience and purpose in life predicted greater habituation to heat pain while resilience, purpose in life, optimism, and social support predicted greater habituation to cold pain. When controlling for the other charac- teristics, both resilience and purpose in life predicted greater habituation to heat and cold pain. Re- silience and associated characteristics such as a sense of purpose in life may be related to enhanced habituation to painful stimuli. Future research should further examine the relationship between re- silience, purpose in life, and habituation to pain and determine whether psychosocial interventions that target resilience and purpose in life improve habituation and reduce vulnerability to chronic pain
Optically transparent IR reflective heat mirror films of ZNS-AG-ZNS
Optically transparent heat mirror films, reflective in the infrared, have been produced based on a dielectric - metal - dielectric design using zinc sulfide and silver coatings. Filters exhibit 87% peak transmission in the visible region, while reflecting 80%. in the infrared. Thermal testing indicated the that the layer filters were unstable to treatments above 300 F. Incorporation of thin barrier coatings of magnesium fluoride between the silver and zinc sulfide lavers produced filters with thermal stability to 700 F while retaining optical characteristics of the three laver svstem. These optical and thermal properties offer possible application for the heat mirror films in tungsten source efficiency improvement applications
Forbidden Pitch or Duty-Free: Revealing the Causes of Across-Pitch Imaging Differences
As resist image responses vary with duty ratio, the identification of a particularly challenging instance leads to its classification as a “forbidden pitch.” The increased application of various RET methods has often resulted in the misuse of this label for anything unexplained by linear effects. This paper attempts to dispel the myths regarding the imaging variations that occur with pitch. Furthermore, by describing the basis of these behaviors, insight is provided for the appropriate design of mask, illumination, OPC, and exposure parameters to best accommodate a broad range of duty ratio values
Image Enhancement through Square Illumination Shaping
Optical imaging is traditionally carried out using circular pupils, assuring the absence of orientation dependency. In the case of IC microlithography however, such dependency exists and is generally limited to orthogonal axes. We have previously reported the potential improvement to lithographic imaging through the use of a square character to an illumination pupil using fully open pupils, square rings, and slot shapes. In this paper we show lithographic results for this shaping at 193nm using a full field (ASML) imaging tool. Results show improvement in both DOF and exposure latitude over conventional circular shaping, leading to the consideration of this approach as a manufacturable method of resolution enhancement
Phase-Shift Mask Issues for 193 nm Lithography
As feature sizes below 0.25 micron are pursued, it becomes apparent that there will be few lithographic technologies capable of such resolution. Of these, deep-UV lithography at 193 urn is being investigated, which may prevail over X-ray lithography in terms of manufacturability. Furthermore, through the use of image enhancement techniques such as phase-shift masking, 193 rim lithography may dominate for feature resolution below 0.20 micron. This paper presents results from investigations into phase-shift mask issues for 193 nm excimer laser lithography. A small field refractive projection system for operation at the 193 .3 nm wavelength of a spectrally narrowed ArF excimer laser has been constructed for lithographic research. The small field, 20X system operates with a variable objective lens numerical aperture from 0.30 to 0.60, variable partial coherence, and control over illumination fill. Through the use of attenuated and alternating phase-shifting techniques resolution can be pushed to the 0.2 micron range with depth of focus as large as 2 microns. Problems do arise, though, as these techniques are applied to such short wavelengths of an excimer laser. Sensitivities to shifter deviations and resist interaction increase. Shifter etch influences on fused silica surface characteristics need to be addressed. Transmission effects of attenuating materials becomes increasingly important. Resist imaging and simulation results presented will shed some light on the potential of phase-shift masking for 193 nm lithography, along with inherent difficulties
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