448 research outputs found

    Norm Detachment: Unwillingness of Millennials to Negotiate

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    Although millennials seem aware of the need for negotiating, salaries paid to starting employees do not always reflect this. It is much more likely for a job candidate to accept an offer for employment without negotiation than it is for a job candidate to bargain for a higher salary. At one point in time bargaining for a higher salary was commonplace. However, due to unknown circumstances millennials seem to be unwilling to negotiate. Our results show that millennials do not negotiate during times viewed as appropriate and times where negotiating could reap substantial benefit. This raises certain questions as to why that may be. We have looked at numerous articles about the behavior of millennials and their skills in negotiating. The results of these articles showed that millennials may not negotiate due to embarrassment or lack of care, but we also found that millennials can be taught how to negotiate. Our research also shows that millennials tend to do things on impulse or for instant gratification

    Multicolor pyrometer for materials processing in space

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    This report documents the work performed by Physical Sciences Inc. (PSI), under contract to NASA JPL, during a 2.5-year SBIR Phase 2 Program. The program goals were to design, construct, and program a prototype passive imaging pyrometer capable of measuring, as accurately as possible, and controlling the temperature distribution across the surface of a moving object suspended in space. These goals were achieved and the instrument was delivered to JPL in November 1989. The pyrometer utilizes an optical system which operates at short wavelengths compared to the peak of the black-body spectrum for the temperature range of interest, thus minimizing errors associated with a lack of knowledge about the heated sample's emissivity. To cover temperatures from 900 to 2500 K, six wavelengths are available. The preferred wavelength for measurement of a particular temperature decreases as the temperature increases. Images at all six wavelengths are projected onto a single CCD camera concurrently. The camera and optical system have been calibrated to relate the measured intensity at each pixel to the temperature of the heated object. The output of the camera is digitized by a frame grabber installed in a personal computer and analyzed automatically to yield temperature information. The data can be used in a feedback loop to alter the status of computer-activated switches and thereby control a heating system

    Propulsion simulation for magnetically suspended wind tunnel models

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    The feasibility of simulating propulsion-induced aerodynamic effects on scaled aircraft models in wind tunnels employing Magnetic Suspension and Balance Systems. The investigation concerned itself with techniques of generating exhaust jets of appropriate characteristics. The objectives were to: (1) define thrust and mass flow requirements of jets; (2) evaluate techniques for generating propulsive gas within volume limitations imposed by magnetically-suspended models; (3) conduct simple diagnostic experiments for techniques involving new concepts; and (4) recommend experiments for demonstration of propulsion simulation techniques. Various techniques of generating exhaust jets of appropriate characteristics were evaluated on scaled aircraft models in wind tunnels with MSBS. Four concepts of remotely-operated propulsion simulators were examined. Three conceptual designs involving innovative adaptation of convenient technologies (compressed gas cylinders, liquid, and solid propellants) were developed. The fourth innovative concept, namely, the laser-assisted thruster, which can potentially simulate both inlet and exhaust flows, was found to require very high power levels for small thrust levels

    Positive diagnostic values and histological detection ratios from the Rotterdam cervical cancer screening programme

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    BACKGROUND: In organized screening programmes for cervical cancer, pre-cancerous lesions are detected by cervical smears. However, during follow-up after a positive smear these pre-cancerous lesions are not always found. The purpose of the study is to analyse positive diagnostic values of smears of at least mild dysplasia, made under the organized screening programmes in the Rotterdam area (1979-1991), and detection ratios of histologically confirmed CIN > or =3, among women participating in these screening programmes. METHODS: Positive diagnostic values and histological detection ratios, by age and history of previous smears, recorded during the national screening programme (1989-1991), were compared with those of the experimental cervical cancer screening project (1976-1984). RESULTS: The positive diagnostic value of a smear with at least severe dysplasia (histologically confirmed CIN > or =3) remains approximately 78%. For smears with mild and moderate dysplasia only lower limits of the diagnostic value could be determined. This was 9% for a smear with mild dysplasia obtained during the national screening programme and 25% and 35% for smears with moderate dysplasia taken during the experimental and national screening programmes respectively. Histological detection ratios for CIN > or =3 in the three rounds of the experimental screening project were 4.7, 2.9 and 1.9. In the first round of the national screening programme the ratio was 4.7, and about three times higher in younger compared to older women. CONCLUSION: Immediate referral for colposcopy after a smear showing moderate dysplasia seems questionable. Whether the increased detection ratio among young women indicates a rise in the risk of cervical cancer is unclear

    Relating jet structure to photometric variability: the Herbig Ae star HD 163296

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    Herbig Ae/Be stars are intermediate-mass pre-main sequence stars surrounded by circumstellar dust disks. Some are observed to produce jets, whose appearance as a sequence of shock fronts (knots) suggests a past episodic outflow variability. This "jet fossil record" can be used to reconstruct the outflow history. We present the first optical to near-infrared (NIR) VLT/X-shooter spectra of the jet from the Herbig Ae star HD 163296. We determine physical conditions in the knots, as well as their kinematic "launch epochs". Knots are formed simultaneously on either side of the disk, with a regular interval of ~16 yr. The velocity dispersion versus jet velocity and the energy input are comparable in both lobes. However, the mass loss rate, velocity, and shock conditions are asymmetric. We find Mjet/Macc ~ 0.01-0.1, consistent with magneto-centrifugal jet launching models. No evidence for dust is found in the high-velocity jet, suggesting it is launched within the sublimation radius (<0.5 au). The jet inclination measured from proper motions and radial velocities confirms it is perpendicular to the disk. A tentative relation is found between the structure of the jet and the photometric variability of the source. Episodes of NIR brightening were previously detected and attributed to a dusty disk wind. We report for the first time significant optical fadings lasting from a few days up to a year, coinciding with the NIR brightenings. These are likely caused by dust lifted high above the disk plane; this supports the disk wind scenario. The disk wind is launched at a larger radius than the high-velocity atomic jet, although their outflow variability may have a common origin. No significant relation between outflow and accretion variability could be established. Our findings confirm that this source undergoes periodic ejection events, which may be coupled with dust ejections above the disk plane.Comment: 20 pages, 11 figures, accepted for publication in Astronomy & Astrophysic

    Ventricular septal defect associated with aneurysm of the membranous septum

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    The most common variety of ventricular septal defect, a perimembranous defect, is frequently associated with a so-called aneurysm of the membranous septum. Previous studies have suggested that ventricular septal defects associated with an aneurysm of the membranous septum tend to spontaneously decrease in size or close more than defects without such an aneurysm. To better define the natural history of this entity, clinical and catheterization data from 87 patients with ventricular septal defect and aneurysm of the membranous septum were reviewed. The initial evaluation was made at a median age of 0.3 years (range 0.1 to 11), with the final evaluation at a median age of 10 years (range 1.5 to 20) and a median duration of follow-up of 8.6 years (range 1.2 to 18.8).Approximately 75% of the ventricular septal defects had a small or no left to right shunt at last evaluation. Overall, 48 patients (55%) had no significant change in the size of the defect, and 39 (45%) showed improvement during the period of observation. Only four patients (5%) had spontaneous closure of the defect. Of the 49 patients who presented with a large left to right shunt, with or without congestive heart failure, 23 (47%) had persistence of a shunt large enough to warrant surgery. When spontaneous improvement occurred, it did so by 6 years of age in all but one patient. Therefore, a continued tendency for a ventricular septal defect associated with an aneurysm of the membranous septum to spontaneously decrease in size or close after this age may be less likely than previously suggested. The actual morphologic substrate of this entity usually consists of tricuspid valve tissue adherent to the edges of the ventricular septal defect

    Targets and genomic constraints of ectopic Dnmt3b expression

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    DNA methylation plays an essential role in mammalian genomes and expression of the responsible enzymes is tightly controlled. Deregulation of the de novo DNA methyltransferase DNMT3B is frequently observed across cancer types, yet little is known about its ectopic genomic targets. Here, we used an inducible transgenic mouse model to delineate rules for abnormal DNMT3B targeting, as well as the constraints of its activity across different cell types. Our results explain the preferential susceptibility of certain CpG islands to aberrant methylation and point to transcriptional state and the associated chromatin landscape as the strongest predictors. Although DNA methylation and H3K27me3 are usually non-overlapping at CpG islands, H3K27me3 can transiently co-occur with DNMT3B-induced DNA methylation. Our genome-wide data combined with ultra-deep locus-specific bisulfite sequencing suggest a distributive activity of ectopically expressed Dnmt3b that leads to discordant CpG island hypermethylation and provides new insights for interpreting the cancer methylome
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