1,984 research outputs found
The Excess Sensitivity of Layoffs and Quits to Demand
Excessive layoffs in bad times and excessive quits in good times both stem from the same weakness in practical employment arrangements: the specific nature of worker-firm relations creates a situation of bilateral monopoly. Institutions which have arisen to avert the associated inefficiency cannot mimic the separation decisions of a perfect-information, first-best allocation rule. Simple employment rules based on predetermined or indexed wages are in many cases the most desirable among the class of feasible employment arrangements. More complicated contracts which seem to deal more effectively with turnover issues are either infeasible because of informational requirements or create adverse incentives on some other dimension.
LargeScale Precursors to Major Lake Effect Snowstorms Lee of Lake Erie
Lakeâeffect snowstorms are primarily a mesoscale feature; however, major lakeeffect snowstorms are linked closely to their synoptic environment. Thus, a lakeeffect system which lasts for more than 24 h cannot only be explained by the boundary layer; it is also associated with the upper tropospheric flow. This research will address whether major lakeâeffect snow events off of Lake Erie can also be associated with largeâscale planetary features several days prior to event onset. The goal is to aid in the forecast process by increasing the accuracy and leadtime of lakeâeffect snow forecasts. This study includes 31 cases recorded from the National Weather Service at Buffaloâs lake effect database. These 31 cases were then stratified into categories depending on its: length, the time of year, and the type of event. This categorization allowed for comparison of the state of the atmosphere in the days prior to different types of events. In order to assess the largeâscale pattern, teleconnections were used as a proxy for the state of the atmosphere. For cases that lasted for greater than 42 hours, there was a correlation to the phase Madden Julian oscillation eight days prior to onset. The cases that occurred during the positive and negative states of the Arctic Oscillation had two different upper level trough patterns, the former originating in Southern Canada and the latter over the Southwestern United States
Differences Between High Shear / Low CAPE Environments in the Northeast US Favoring Straight-Line Damaging Winds versus Tornadoes
High shear / low CAPE (HSLC) environments are common in the Northeast US and can occur at any time of year. Severe weather in HSLC environments is notoriously hard to predict, often catching both forecasters and the general public off-guard. The goal of this project is to help forecasters to identify HSLC environments favorable for severe weather in the Northeast US, and to discriminate between HSLC environments that are supportive of tornadoes versus those that favor straight-line damaging winds (SDW). A 10-year HSLC severe weather environmental climatology was created for the Northeast US (New England, New York, New Jersey, Pennsylvania). This climatology includes 54 different parameters that can be used to identify and describe severe weather environments. HSLC criteria was defined as surface-based CAPE (SBCAPE) †500 J kgâ1, most unstable parcel CAPE (MUCAPE) and mixed-layer CAPE (MLCAPE) †1000 J kgâ1, and 0â6-km wind shear â„ 18 m sâ1 (Sherburn et al. 2016). Events included in the climatology consisted of numerous (â„5) straight-line damaging wind reports, or at least 1 tornado report. Each event was classified by the season in which it occurred and the mode (discrete, cluster of cells, quasi-linear convective system (QLCS)) of the storm which produced the reports. Results show that warm-season HSLC severe events typically occurred either at the beginning or at the tail end of an event in an environment where CAPE values were predominantly too large to meet the HSLC criteria. Storm mode was variable for warm-season events, but cool-season events were dominated by QLCSs. Results show lifted condensation levels (LCLs) as well as low-level shear and wind direction as some of the most skillful parameters at discriminating between tornadic and non-tornadic events. There are various other useful parameters, including but not limited to, surface relative humidity, effective shear magnitude, and convective inhibition. The usefulness of these, and other parameters, at discriminating between HSLC environments favorable for SDW versus tornadoes will be discussed
The Concept of DC Gain in Modeling Secular Variations in Atmospheric 14C
A constraint on radiocarbon reservoir models is that the DC gain of a system (system transfer function at zero frequency) should equal the equilibrium ratio of the atmospheric radiocarbon mass to the production rate. The simple one-box model is essentially a "black box" but the value of the single residence time is theoretically equal to the DC gain. Using a sunspot-production rate algorithm as the forcing function, predictions of the one-box model match the 14C data from AD 1700 to 1900 better than the 3-box, 5-box and box-diffusion models. The more complex models tend to pile up 14C in the atmosphere because their DC gains are too high, and they overattenuate the de Vries "wiggles". The DC gains can be reduced to more acceptable levels by adjusting model parameters, particularly the sizes of the ocean reservoirs. Better fits to the "wiggles" are also obtained by parameter adjustment. Water content of deep-sea sediments constitutes an extra reservoir for dead carbon, and should help reduce system DC gain.This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
Signaling in Secret: Pay-for-Performance and the Incentive and Sorting Effects of Pay Secrecy
Key Findings: Pay secrecy adversely impacts individual task performance because it weakens the perception that an increase in performance will be accompanied by increase in pay; Pay secrecy is associated with a decrease in employee performance and retention in pay-for-performance systems, which measure performance using relative (i.e., peer-ranked) criteria rather than an absolute scale (see Figure 2 on page 5); High performing employees tend to be most sensitive to negative pay-for- performance perceptions; There are many signals embedded within HR policies and practices, which can influence employeesâ perception of workplace uncertainty/inequity and impact their performance and turnover intentions; and When pay transparency is impractical, organizations may benefit from introducing partial pay openness to mitigate these effects on employee performance and retention
Leading-effect vs. Risk-taking in Dynamic Tournaments: Evidence from a Real-life Randomized Experiment
Two 'order effects' may emerge in dynamic tournaments with information feedback. First, participants adjust effort across stages, which could advantage the leading participant who faces a larger 'effective prize' after an initial victory (leading-effect). Second, participants lagging behind may increase risk at the final stage as they have 'nothing to lose' (risk-taking). We use a randomized natural experiment in professional two-game soccer tournaments where the treatment (order of a stage-specific advantage) and team characteristics, e.g. ability, are independent. We develop an identification strategy to test for leading-effects controlling for risk-taking. We find no evidence of leading-effects and negligible risk-taking effects
Selective targeting of IL-2 to NKG2D bearing cells for improved immunotherapy
Despite over 20 years of clinical use, IL-2 has not fulfilled expectations as a safe and effective form of tumour immunotherapy. Expression of the high affinity IL-2Rα chain on regulatory T cells mitigates the anti-tumour immune response and its expression on vascular endothelium is responsible for life threatening complications such as diffuse capillary leak and pulmonary oedema. Here we describe the development of a recombinant fusion protein comprised of a cowpox virus encoded NKG2D binding protein (OMCP) and a mutated form of IL-2 with poor affinity for IL-2Rα. This fusion protein (OMCP-mutIL-2) potently and selectively activates IL-2 signalling only on NKG2D-bearing cells, such as natural killer (NK) cells, without broadly activating IL-2Rα-bearing cells. OMCP-mutIL-2 provides superior tumour control in several mouse models of malignancy and is not limited by mouse strain-specific variability of NK function. In addition, OMCP-mutIL-2 lacks the toxicity and vascular complications associated with parental wild-type IL-2
Job Search Behavior of Employed Managers
Job search typically has been thought of as an antecedent to voluntary turnover or job choice behavior. This study extends the existing literature by proposing a model of the job search process and examining the job search behavior of employed managers. Managers were initially surveyed about their job search activity over the past year. Approximately one year later, the same managers were surveyed to assess whether they had changed jobs since the initial survey, and the circumstances surrounding the job change. This survey data was matched with job, organizational, and personal information contained in the data base of a large executive search firm. Results suggest that dissatisfaction with different aspects of the organization and job were more strongly related to job search than were perceptions of greener pastures. Moreover, although some job search activity does facilitate turnover, a considerable amount of search does not lead to turnover. Thus, it appears that search serves many purposes. Implications of managerial job search on organizations are discussed
The Primordial Inflation Polarization Explorer (PIPER)
The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne
cosmic microwave background (CMB) polarimeter designed to search for evidence
of inflation by measuring the large-angular scale CMB polarization signal.
BICEP2 recently reported a detection of B-mode power corresponding to the
tensor-to-scalar ratio r = 0.2 on ~2 degree scales. If the BICEP2 signal is
caused by inflationary gravitational waves (IGWs), then there should be a
corresponding increase in B-mode power on angular scales larger than 18
degrees. PIPER is currently the only suborbital instrument capable of fully
testing and extending the BICEP2 results by measuring the B-mode power spectrum
on angular scales = ~0.6 deg to 90 deg, covering both the reionization
bump and recombination peak, with sensitivity to measure the tensor-to-scalar
ratio down to r = 0.007, and four frequency bands to distinguish foregrounds.
PIPER will accomplish this by mapping 85% of the sky in four frequency bands
(200, 270, 350, 600 GHz) over a series of 8 conventional balloon flights from
the northern and southern hemispheres. The instrument has background-limited
sensitivity provided by fully cryogenic (1.5 K) optics focusing the sky signal
onto four 32x40-pixel arrays of time-domain multiplexed Transition-Edge Sensor
(TES) bolometers held at 140 mK. Polarization sensitivity and systematic
control are provided by front-end Variable-delay Polarization Modulators
(VPMs), which rapidly modulate only the polarized sky signal at 3 Hz and allow
PIPER to instantaneously measure the full Stokes vector (I, Q, U, V) for each
pointing. We describe the PIPER instrument and progress towards its first
flight.Comment: 11 pages, 7 figures. To be published in Proceedings of SPIE Volume
9153. Presented at SPIE Astronomical Telescopes + Instrumentation 2014,
conference 915
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