754 research outputs found
The Firm as a Community Explaining Asymmetric Behavior and Downward Rigidity of Wages
This paper models the firm as a community Ă la Akerlof (1980) to account for asymmetric behavior, and in particular, downward rigidity of wages. It is shown that, through social interaction among workers in the firm community, wage cuts can give rise to a large, discontinuous fall in labor productivity (known as âcatastropheâ). Furthermore, this large fall in labor productivity will persist or display inertia (known as âhysteresisâ) even if the wages are restored to the pre-cut level and beyond. Our catastrophe/hysteresis finding with respect to wage cuts can rationalize the downward rigidity of wage behavior, and is consistent with the interview evidence of fragile worker morale emphasized by Bewley (1999) and others in explaining why employers are sensitive to and refrain from cutting worker pay.Wage rigidity, Firm community, Catastrophe, Hysteresis
Receiprocity and Downward Wage Rigidity
The employment relationship is to a large extent characterized by incomplete contracts, in which workers have a considerable degree of discretion over the choice of their work effort. This discretion at work kicks in the potential importance of âgift exchangeâ or reciprocity between workers and employers in their employment relationship. Built on the seminal work of Akerlof (1980), this paper adopts a social norm approach to model reciprocity in labor markets and theoretically derives two versions of downward wage rigidity. The first version explains why employers may adopt a high wage policy far above the competitive level. This version is not a novel finding in the existing literature and is mainly served as a benchmark for later comparison in the current paper. Our main contribution lies in the second version in which not nly may employers adopt a high wage policy far above the competitive level, but one can also account for the asymmetric behavior of wages and explain why employers are hesitant about wage cuts in the presence of negative shocks. We argue that this second and stronger version of downward wage rigidity has moved the efficiency wage theory a step forward.Reciprocity, Downward Wage Rigidity, Social Norm, Efficiency Wage
The application of user log for online business environment using content-based Image retrieval system
Over the past few years, inter-query learning has gained much attention in the research and development of content-based image retrieval (CBIR) systems. This is largely due to the capability of inter-query approach to enable learning from the retrieval patterns of previous query sessions. However, much of the research works in this field have been focusing on analyzing image retrieval patterns stored in the database. This is not suitable for a dynamic environment such as the World Wide Web (WWW) where images are constantly added or removed. A better alternative is to use an image's visual features to capture the knowledge gained from the previous query sessions. Based on the previous work (Chung et al., 2006), the aim of this paper is to propose a framework of inter-query learning for the WWW-CBIR systems. Such framework can be extremely useful for those online companies whose core business involves providing multimedia content-based services and products to their customers
A loop-mediated isothermal amplification (LAMP) assay for rapid detection of Anaplasma phagocytophilum infection in dogs
A simple and rapid diagnostic method of Anaplasma phagocytophilum infection was established, employing the loop-mediated isothermal amplification (LAMP) reaction. With 1 set of 4 specific primers targeting the citrate synthase (gltA) gene of A. phagocytophilum, the LAMP assay rapidly amplified the target DNA sequence in a single tube in 1 h, requiring only a water bath for reaction. When visualized by gel electrophoresis, the LAMP products appeared as a ladder-like pattern, with many bands of different sizes from 180 base pairs up to the loading well. The results obtained from testing 32 clinical blood samples of dogs demonstrated that the LAMP method was more sensitive than nested PCR in the diagnosis reaction for the detection of A. phagocytophilum DNA
Green and efficient production of octyl hydroxyphenylpropionate using an ultrasound-assisted packed-bed bioreactor
A solvent-free system to produce octyl hydroxyphenylpropionate (OHPP) from p-hydroxyphenylpropionic acid (HPPA) and octanol using immobilized lipase (Novozym(A (R)) 435) as a catalyst in an ultrasound-assisted packed-bed bioreactor was investigated. Response-surface methodology (RSM) and a three-level-three-factor Box-Behnken design were employed to evaluate the effects of reaction temperature (x (1)), flow rate (x (2)) and ultrasonic power (x (3)) on the percentage of molar production of OHPP. The results indicate that the reaction temperature and flow rate were the most important variables in optimizing the production of OHPP. Based on a ridge max analysis, the optimum conditions for OHPP synthesis were predicted to consist of a reaction temperature of 65A degrees C, a flow rate of 0.05 ml/min and an ultrasonic power of 1.74 W/cm(2) with a yield of 99.25%. A reaction was performed under these optimal conditions, and a yield of 99.33 +/- A 0.1% was obtained
Correlations of structural, magnetic, and dielectric properties of undoped and doped CaCu3Ti4O12
The present work reports synthesis, as well as a detailed and careful
characterization of structural, magnetic, and dielectric properties of
differently tempered undoped and doped CaCu3Ti4O12 (CCTO) ceramics. For this
purpose, neutron and x-ray powder diffraction, SQUID measurements, and
dielectric spectroscopy have been performed. Mn-, Fe-, and Ni-doped CCTO
ceramics were investigated in great detail to document the influence of
low-level doping with 3d metals on the antiferromagnetic structure and
dielectric properties. In the light of possible magnetoelectric coupling in
these doped ceramics, the dielectric measurements were also carried out in
external magnetic fields up to 7 T, showing a minor but significant dependence
of the dielectric constant on the applied magnetic field. Undoped CCTO is
well-known for its colossal dielectric constant in a broad frequency and
temperature range. With the present extended characterization of doped as well
as undoped CCTO, we want to address the question why doping with only 1% Mn or
0.5% Fe decreases the room-temperature dielectric constant of CCTO by a factor
of ~100 with a concomitant reduction of the conductivity, whereas 0.5% Ni
doping changes the dielectric properties only slightly. In addition,
diffraction experiments and magnetic investigations were undertaken to check
for possible correlations of the magnitude of the colossal dielectric constants
with structural details or with magnetic properties like the magnetic ordering,
the Curie-Weiss temperatures, or the paramagnetic moment. It is revealed, that
while the magnetic ordering temperature and the effective moment of all
investigated CCTO ceramics are rather similar, there is a dramatic influence of
doping and tempering time on the Curie-Weiss constant.Comment: 10 pages, 11 figure
Energetic Modes in Turbulent Pipe Flow From Resolvent Analysis
We describe a method to investigate the mode shapes in turbulent pipe flow at a given
wavenumber pair that are most responsive to harmonic forcing in the sense that the they
correspond to the largest singular value in a Schmidt decomposition of the linear Navier-Stokes operator using the turbulent mean profile as the base flow. The ideas follow logically
from the work of Sharma & McKeon (2009), who considered a similar approach for laminar pipe flow
The synthesized 2-(2-fluorophenyl)-6,7-methylenedioxyquinolin-4-one (CHM-1) promoted G2/M arrest through inhibition of CDK1 and induced apoptosis through the mitochondrial-dependent pathway in CT-26 murine colorectal adenocarcinoma cells
In this study, we investigated the effects of 2-(2-fluorophenyl)-6,7-methylenedioxyquinolin-4-one (CHM-1) on cell viability, cell cycle arrest and apoptosis in CT-26 murine colorectal adenocarcinoma cells. For determining cell viability, the MTT assay was used. CHM-1 promoted G2/M arrest by PI staining and flow cytometric analysis. Apoptotic cells were evaluated by DAPI staining. We used CDK1 kinase assay, Western blot analysis and caspase activity assays for examining the CDK1 activity and proteins correlated with apoptosis and cell cycle arrest. The in vivo anti-tumor effects of CHM-1-P were evaluated in BALB/c mice inoculated with CT-26 cells orthotopic model. CHM-1 induced CT-26 cell viability inhibition and morphologic changes in a dose-dependent and time-dependent manner and the approximate IC(50) was 742.36 nM. CHM-1 induced significant G2/M arrest and apoptosis in CT-26 cells. CHM-1 inhibited the CDK1 activity and decreased CDK1, Cyclin A, Cyclin B protein levels. CHM-1 induced apoptosis in CT-26 cells and promoted increasing of cytosolic cytochrome c, AIF, Bax, BAD, cleavage of pro-caspase-9, and -3. The significant reduction of caspase-9 and -3 activity and increasing the viable CT-26 cells after pretreated with caspase-9 and -3 inhibitor indicated that CHM-1-induced apoptosis was mainly mediated a mitochondria-dependent pathway. CHM-1-P improved mice survival rate, and enlargement of the spleen and liver metastasis were significantly reduced in groups treated with either 10 mg/kg and 30 mg/kg of CHM-1-P and 5-FU in comparison to these of CT-26/BALB/c mice. Taken together, CHM-1 acted against colorectal adenocarcinoma cells in vitro via G2/M arrest and apoptosis, and CHM-1-P inhibited tumor growth in vivo
Quantum Cryptography Using Single Particle Entanglement
A quantum cryptography scheme based on entanglement between a single particle
state and a vacuum state is proposed. The scheme utilizes linear optics devices
to detect the superposition of the vacuum and single particle states. Existence
of an eavesdropper can be detected by using a variant of Bell's inequality.Comment: 4 pages, 3figures, revte
Cosmological background solutions and cosmological backreactions
The cosmological backreaction proposal, which attempts to account for
observations without a primary dark energy source in the stress-energy tensor,
has been developed and discussed by means of different approaches. Here, we
focus on the concept of cosmological background solutions in order to develop a
framework to study different backreaction proposals.Comment: 14 pages, 5 figures; major changes, replaced to match the version
published in General Relativity and Gravitatio
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