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Strong clinical data demonstrate that inflammatory bowel disease (IBD) is an independent risk factor for Clostridiodes difficile infection (CDI) and suggest a globally increased prevalence and severity of C. difficile coinfection in IBD patients (CDI-IBD). In addition to elderly individuals, children are also at higher risk of CDI-IBD. Rapid diagnosis is essential since the clinical manifestations of active IBD and CDI-IBD are indistinguishable. Antibiotics have been well established in the treatment of CDI-IBD, but they do not prevent recurrence. Herein, the authors focus on reviewing recent research advances on the new therapies of CDI-IBD. The novel therapies include gut microbiota restoration therapies (such as prebiotics, probiotics and FMT), immunotherapy (such as vaccines and monoclonal antibodies) and diet strategies (such as groningen anti-inflammatory diet and mediterranean diet). Future extensive prospective and placebo-controlled studies are required to evaluate their efficacy and long-term safety. Available studies show that the prevalence of CDI-IBD is not optimistic. Currently, potential treatment options for CDI-IBD include a number of probiotics and novel antibiotics. This review updates the knowledge on the management of CDI in IBD patients, which is timely and important for GI doctors and scientists. [ABSTRACT FROM AUTHOR]

In this paper, the complete f-moment convergence for weighted sums of sequences of extended negatively dependent random variables is investigated. As a result, we not only extend and generalize some results on complete convergence obtained by Wu and Zhai (Journal of Mathematical Inequalities, 13(1): 251-260, 2019), but also get some results on the complete consistency for the estimator of nonparametric regression models and provide some simulations to assess the validity of our theoretical results. [ABSTRACT FROM AUTHOR]

In this paper, we primarily focus on the edge frequency polygon estimator of $ f(x) $ f (x) , which represents the probability density function of a sequence of φ-mixing random variables $ \{X_i, i\geq 1\} $ { X i , i ≥ 1 }. We establish the uniformly strong consistency and the convergence rate of asymptotic normality for the edge frequency polygon estimator under suitable conditions. Notably, the convergence rate achieves $ O(n^{-1/6}) $ O (n − 1 / 6) , which is more precise compared to the corresponding rate mentioned in the existing literature. Additionally, we present simulation studies to validate the theoretical results. [ABSTRACT FROM AUTHOR]

Combined with infrared thermography measurements, large eddy simulation was used to study the square-wave pulsating film cooling on turbine vane at the time-averaged blowing ratios of 0.5 and 1.5. On suction surface, the introduction of coolant pulsation results in the decrease of cooling effectiveness. On pressure surface, coolant pulsation at high blowing ratio can improve coolant coverage. Starting vortex is the typical structure in pulsating film cooling. However, on suction surface, due to fully-turbulent mainstream, plenty of small-scale vortices play a dominating role in flow fields, and the effect of starting vortex is unobvious. The statistic characteristics and power spectrum density (PSD) of velocity fluctuation were also analyzed in detail. The results show that the disturbance of coolant jet on suction-side mainstream boundary layer is very weak, However, on pressure side, coolant pulsation causes notable increase of PSD and turbulent kinetic energy. [ABSTRACT FROM AUTHOR]

Center cone locating at the rear portion of turbine is the key component of the integrated afterburner. Numerical studies were carried out to investigate full-coverage film cooling on center cone at engine-realistic conditions, and the effects of thermodynamic and geometric parameters on cooling effectiveness and aerodynamic loss were discussed in detail. The numerical model was validated by the infrared measured experiments. Two recirculation vortices were generated on the cone surface, and cause the reverse ejection of coolant. These two recirculation vortices were promoted by increasing blowing ratio, and mixed with each other as the blowing ratio reaches 3.0. Along the streamwise direction, cooling effectiveness decreases and reaches the minimum value at the tip of cone, which is very different from the flat-plate film cooling. Cooling effectiveness increases with the increases of blowing ratio, hole diameter and density ratio, but decreases with the increases of hole pitch and spacing. The discharge coefficient increases with the increases of hole diameter and inclination angle, but decreases with the increases of blowing ratio, hole pitch and spacing. Pure film cooling and double-wall cooling were also compared. The introduction of jet impingement cooling can generate higher cooling effectiveness, especially at low and medium blowing ratio, but causes the notable increase of pressure drop. [ABSTRACT FROM AUTHOR]

In this paper, we study the weak convergence and convergence rate in the weak law of large numbers for weighted sums of a class of random variables satisfying the Rosenthal type inequality. The necessary and sufficient conditions for the convergence rates in the weak law of large numbers under some mild conditions are provided. Moreover, the main results that we established are applied to simple linear errors-in-variables regression models and nonparametric regression models based on a class of random errors. Finally, we present some numerical simulations to assess the finite sample performance of the theoretical results. [ABSTRACT FROM AUTHOR]

Large-eddy simulations were conducted to study the film cooling characteristics of a serrated trenched-hole cooling geometry on a scaled turbine guide vane. The simulations were carried out under a blowing ratio of M = 2.0. The serrated trench was placed on the suction and pressure side, respectively. The results show that the mainflow environment above the suction side differs from that above the pressure side. Therefore the adiabatic film cooling effectiveness changes correspondingly. Within the range of x/d = 3 to x/d = 25, the are-averaged adiabatic film cooling effectiveness on the pressure side is about 21% higher than that on the suction side. By presenting the vortex structure and unstable statistic results of the trenched-hole region and downstream flow field, the present study analyses in detail the characteristics of the coolant flow patterns and the coolant-mainflow interaction at both the suction and pressure side. Results show that the cooling jet penetration is suppressed on the suction side, while the intense mainflow entrainment results in dramatic destruction of the cooling film protection. Unlike the situation at the suction side, although coolant penetration is more substantial on the pressure side, film cooling shows good performance due to the unstable concave flow. [ABSTRACT FROM AUTHOR]

The structural optimization of a specific laminated cooling structure is conducted under gas turbine combustor representative aero-thermal conditions, with the aim at improving its overall cooling effectiveness. The optimization procedure is realized by using conjugate heat transfer CFD analysis and radial basis function neural network (RBFNN) surrogated model. For this specific laminated cooling structure, both the thickness of impinging plate (ti) and the thickness of film cooling plate (tf) are all fixed as 0.5 mm. The other geometric parameters including impinging-hole diameter(di), pin-fin diameter(dp), film-hole diameter (df), inner height of double walls (H), streamwise hole-to-hole pitch (S) and spanwise hole-to-hole pitch (P) are selected as the design variables. Two geometric constrains are considered that the total thickness of laminated cooling structure is not bigger than 2 mm, and the minimum clearance between adjacent fins should be bigger than 0.5 mm. By using the current CFD-based optimization methodology, the optimized laminated cooling structures are presented from the given range of possible geometric variables. An optimized laminated cooling structures makes the maximum spatially-averaged overall cooling effectiveness approach to 0.9, and the other for minimum relative total pressure drop can reach 0.17%. Moreover, it is found that the thermal stress has a regularity with the overall cooling effectiveness. [ABSTRACT FROM AUTHOR]

Combined with infrared thermography experiments, large-eddy simulation was used for studying trench film cooling on C3X vane model at the mainstream Reynolds number of 2.5 × 105 based on the chord length, and nominal blowing ratios of 0.5 and 1.5. The instantaneous and time-averaged characteristics for trench film cooling were analzyed in detail. Inside the trench, a pair of recirculation vortices promotes the coolant spreading on spanwise direction, mitigates the jet penetration into mainstream, and improves cooling effectiveness. On pressure surface, hairpin vortices play the dominate role in the unsteady flow fields. Downstream of the trench, a streamwise vortex pair corresponding to anti-CRVP (Counter rotating vortex pair) is generated on both sides of hairpin structures, and causes high turbulent fluctuation. On suction surface, the mainstream boundary layer transits from laminar to turbulent flow in the upstream of the coolant exit, and large numbers of small-scale vortices dominate the flow dynamics. Spectrum analysis of pressure signals shows that, on pressure surface, trench and round-hole film cooling both exhibit strong periodicity. On suction surface, randomness is more pronounced. The statistical characteristics of velocity and temperature fluctuations were also discussed in detail. Overall, significant cooling augmentation by trench hole is seen on both the suction and pressure surfaces, especially at high blowing ratio. [ABSTRACT FROM AUTHOR]

A numerical investigation is performed to study the effects of transverse trenches on the film cooling performances of single row film cooling holes on the turbine guide vane, under the engine-representative conditions. Two trenches are investigated in the current study, including a conventional straight trench and a novel serrated trench, both having the same slot width of 2.5d and depth of 0.75d. With the presence of trenches, the kidney vortices are effectively destroyed at the suction side, replaced by a pair of secondary vortices originating from the edge of trench slot, with a sense of rotation opposite to the kidney-vortex pair. However, at the pressure side, the kidney vortices remain clearly in the trenched-hole cases. The roles of trenched-hole on the film cooling enhancement behave more pronounced on the pressure surface when compared to the respective one on the suction surface. On the pressure surface, the serrated trench displays a more obvious role in the film cooling enhancement when compared to the straight trench. Combined with the effects of trenched-hole on the enthalpy loss coefficient, it is suggested that the trenches are more reasonably used on the pressure surface. [ABSTRACT FROM AUTHOR]

Twenty-four novel 5-phenyl-1,3,4-oxadiazole-2-thiol (POT) analogues, benzo[d]oxazole-2-thiol, benzo[d]thiazole-2-thiol and 5-methyl-1,3,4-thiadiazole-2-thiol-substituted N,N-bis(2-hydroxyethyl) quaternary ammonium salts (QAS) (5a-d, 6a-d, 7a-d, 10a-d, 13a-d, 16a-d) were prepared and characterised by FTIR, NMR and elemental analysis. Part of target compounds (5d, 6d, 7d, 10d, 13d, 16d) displayed potent antimicrobial effect against ten common pathogens (S. aureus, α-H-tococcus, β-H-tococcus, E. coli, P. aeruginosa, Proteus vulgaris, Canidia Albicans, Cytospora mandshurica, Physalospora piricola, Aspergillus niger) and had relatively low cytotoxity against two human cell lines (HaCat and LO2). TEM and SEM images of E. coli and S. aureus morphologies treated with 7d showed that the antibacterial mechanism might be the QAS fixing on cell wall surfaces and puncturing to result in the release of bacterial cytoplasm. This study provides new information of QAS, which could be used to design novel antimicrobial agents applied in clinic or agriculture. [ABSTRACT FROM AUTHOR]

In this paper, a new universal current-mode filtering circuit with single input and multi-outputs based on OTAs (operational transconductance amplifiers) is proposed. The circuit just consists of two operational transconductance amplifiers, one current controlled current amplifier with multi-outputs (MO-CCCA), and two grounded capacitors. It can realize low-pass, band-pass, high-pass, band-stop, and all-pass filters simultaneously. Its quality factor and natural frequency can be tuned independently and the sensitivities are very low. Moreover, the non-ideal characteristic of the proposed filter is analysed and simulated by PSPICE. [ABSTRACT FROM AUTHOR]

Nylon copolymer/clay (NC) nanocomposites were prepared using PA6/66 as a matrix and organoclay as a nanofiller through a two-step melt-compounding method. It was shown that the organoclay flakes were well exfoliated and dispersed in the PA6/66 matrix. With increasing content of organoclay, the apparent shear viscosity and the entrance pressure drop of the NC nanocomposites decreased whereas the corresponding shear activation energy increased, suggesting that the NC nanocomposites were suitable to be used in shear-flow rather than extension-flow related processes. Investigations of the crystallization behaviors of the NC nanocomposites indicated that the organoclay addition was capable of facilitating the γ-form crystal formation, which is suggested to be due to the restriction effect of the organoclay on the PA6/66 chain motion during the crystallization. Compared to the neat PA6/66, the tensile strength and elongation at break of the NC nanocomposites were both enhanced at an appropriate content of the organoclay. In addition, the NC nanocomposites exhibited enhanced barrier properties due to the high specific surface area and the homogeneous dispersion of the organoclay. [ABSTRACT FROM AUTHOR]

The properties and characteristics of metal oxide and sulfate catalysts with different active elements for selective catalytic reduction of NO with NH3were investigated. Cerium-based oxide catalyst showed the widest temperature window for NOxremoval and manganese-based oxide catalyst exhibited the best catalytic performance at low temperature. For all the catalysts, the SCR activities at low temperature were directly related with the redox abilities of catalysts. The existence of sulfate groups inhibited the redox abilities of active species for sulfate catalysts compared with the metal oxide catalysts. The catalytic activities of CeWTi-S and MnWTi-S were seriously decreased in contrast to CeWTi-N and MnWTi-N. The temperature window of CuWTi-S was shifted toward higher temperature comparing with CuWTi-N. The FeWTi-N and FeWTi-S catalysts both showed high NOxconversion in the temperature range between 300°C and 400°C and N2O concentrations for iron-based samples were least among the same kind of catalysts. The abundance of acid sites and weak stability of surface sulfate groups for iron- and copper-based sulfate catalysts might be the main reasons accounting for the better NOxconversion in the medium-temperature range. [ABSTRACT FROM AUTHOR]

In this paper, a new current differencing cascaded transconductance amplifier (CDCTA) is presented. The CDCTA circuit consists of a current differencing unit and n cascaded highly linear voltage-controlled transconductance amplifiers, and it possesses wide bandwidth and lineartunable feature. Based on this CDCTA, a systematic design method generating current-mode (CM) multiple-loop feedback filter is proposed. By altering the parameters of the design matrix, multiple nth-order CM all-pole low pass filters structures can be synthesized without changing internal circuit. The nth-order filters have low complexity and meet the requirement of no active and passive element matching conditions as adopting only a single CDCTA and n grounded capacitors. Furthermore, the frequency of the nth-order filters can be linearly tuned by the bias voltage. A fourth-order Butterworth filter is designed as an example, and its Cadence simulation results have good agreement with the theoretical analysis. [ABSTRACT FROM AUTHOR]

Using hexa(4-carboxylphenoxy)cyclotriphosphazene (HCPCP) with six carboxyl groups as the core, a new kind of star-branched PA12 with hexafunctional cyclotriphosphazene core was prepared in the ring-opening polymerization of ω-laurolactam. The relationship between the structure and properties of star-branched PA12 had been systematically investigated. Compared with linear PA12, star-branched PA12 has lower relative viscosity and higher melt flow rate while its mechanical properties can be almost retained by the use of star-branching and an appropriate molecular weight. Research on crystallization and rheological behaviors indicate that star-branched PA12 with appropriate molecular weight has the faster crystallization rate, the higher flowability and the lower processing temperature and pressure than linear PA12, which could be used as the easy processing polyamide resin for the rapid molding process. [ABSTRACT FROM PUBLISHER]

In this paper, a new fourth-order complex (polyphase) filter is realized with the leapfrog structure. The proposed filter is based on the first-order stage using multi-output current differencing transconductance amplifiers (MOCDTAs). The design procedures for the realization of the first-order stage and fourth-order leapfrog polyphase filter are presented. In the procedures, the signal flow diagrams are also presented. The proposed design using MOCDTA simplifies the circuit of the current-mode leapfrog complex filter, where there are no resistors and with minimum number of active components. Besides, its centre frequency and bandwidth could be electrically tunable independently. The centre frequency of the proposed filter could be adjusted from 20 to 80 MHz, and its bandwidth could be more than 20 MHz. With ± 1.25 V supply, two examples of the proposed filter are introduced. Their bandwidths are from 46.1 to 68.5 MHz and from 22.3 to 48.4 MHz, respectively. Their image rejection ratios could be more than 59 and 39 dB, respectively. Meanwhile, both the IIP3s are over 18 dBm. The theoretical results are demonstrated by using SPECTRE simulation in CHRT 0.18 μm standard complementary metal oxide semiconductor (CMOS) process. [ABSTRACT FROM PUBLISHER]

A novel drug delivery system was developed through the modification of MSNs (mesoporous silica nanoparticles) with β-CD (β-Cyclodextrin). The experiment results demonstrated that the cytotoxicity of this drug delivery system was very low, and the doxorubicin loading ratio was ~27.36%. The behaviour of drug release was pH dependent and it can be used as the drug controlling releasing in cancer cell. The combination of doxorubicin and this drug delivery system (MSN-NH2-CD-Biotin) could arrest the cancer cell in G2 phase, and it could make the cancer cell apoptosis by doxorubicin more effectively. [ABSTRACT FROM AUTHOR]

In this article, we propose a novel high-performance complementary metal oxide semiconductor (CMOS) current differencing transconductance amplifier (CDTA) with a transconductance gain (GM) that can be linearly tuned by a voltage. By using a high-speed, low-voltage, cascaded current mirror active resistance compensation technique, the proposed CDTA circuit exhibits wide frequency bandwidths, high current tracking precisions as well as large output impedances. The linear-tunableGMof the CDTA is designed with the use of linear composite metal oxide semiconductor field-effect transistor as basic cells in the circuit. Combining these two approaches, several design concerns are studied, including: impedance characteristic, tracking errors, offset and linearity and noise. The prototype chip with a 0.25 mm2area is fabricated in aGlobalFoundries’0.18 μmCMOS process. The simulated results and measured results with ±0.8 V DC supply voltages are presented, and show extremely wide bandwidths and wide linear tuning range. In addition, a fully differential band-pass filter for a high-speed system is also given as an example to confirm the high performance of the proposed circuit. [ABSTRACT FROM AUTHOR]

Context: Many traditional Chinese medicines (TCMs) can act as either immunosuppresants or immunostimulants, properties that have lead to their increasing use as immunomodulators in the treatment of disease. Recently, our lab successfully identified a dimer epicatechin-(2β→O → 7, 4β→8)-ent-epicatechin (EEE) from the chloroform extract ofRhododendron spiciferum. Objective: To evaluate the immunomodulatory effects of EEEin vitro. Materials and methods: Splenocytes, peritoneal macrophages and peripheral blood mononuclear cells from BALB/c mice were incubated with different concentrations of EEE. Results: EEE significantly stimulates splenocyte proliferation when administered either alone or in combination with concanavalin A (Con A), lipopolysaccharide (LPS), and Anti-CD3. EEE enhances the cytotoxicity of natural killer (NK) cells markedly and phagocytic function of macrophage. Moreover, we found that the levels of several helper T1 (Th1) cytokines, including interleukin-2 (IL-2), IL-12, interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) are significantly increased after EEE treatment, while the levels of Th2 cytokine IL-4 and IL-10 are significantly decreased. As a result, the ratio of Th1/Th2 is significantly increased in the presence of EEE. EEE also increased CD4 and CD8 cell populations. Conclusion: These results indicate that EEE exhibits immunomodulatory activity and suggests that this compound could be developed as a novel immunotherapeutic agent for treating cancer and other immune-mediated diseases. [ABSTRACT FROM PUBLISHER]

This paper presents two new current differencing transconductance amplifiers (CDTAs)-based electronically tunable current-mode four-phase quadrature oscillators (QO). The proposed QOs consist of two CDTAs, one resistor and two grounded capacitors, respectively, which are suitable for monolithic integration. The condition of oscillation (CO) and frequency of oscillation (FO) can be independently controlled, and the FO can be electronically tunable by adjusting the bias current of the CDTA. Moreover, the QOs can provide four quadrature output currents at high-output-impedance nodes, which enable the QOs can be connected directly to the next stage without any impedance matching requirements. Cadence IC Design Tools 5.1.41 (Cadence Design Systems Inc., San Jose, CA) post-layout simulation results and experimental evidence are included to confirm the theory. [ABSTRACT FROM PUBLISHER]

Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) initiated by ethyl 2-bromoisobutyrate (EBiB) was approached for the first time in the absence of oxygen and in the presence of air, using a novel catalyst system based on SmBr3·6H2O/isophthalic acid complexes and using ascorbic acid (VC) as a reducing agent. Both the polymerization in the absence of oxygen and in the presence of air proceeded in a well-controlled manner as evidenced by kinetic studies. Compared with the polymerization in the absence of oxygen, the polymerization in the presence of air provided rather slow reaction rate and showed better control of molecular weight and its distribution under the same experimental conditions. The polymerization apparent activation energies in the absence of oxygen and in the presence of air were calculated to be 47.1 and 51.3 kJ·mol-1, respectively. A slow polymerization rate and a broad polydispersity index were observed using anisole and toluene instead of DMF as solvent. Polyacrylonitrile obtained was successfully used as a macroinitiator to proceed the chain extension polymerization of styrene via AGET ATRP in the presence of air. [ABSTRACT FROM AUTHOR]

Reverse atom transfer radical polymerization (RATRP) has been successfully applied in the synthesis of polyacrylonitrile (PAN) with FeCl3/acetic acid as catalyst in the presence of conventional initiator azobisisobutyronitrile (AIBN) at 65°C in N,N-dimethylformamide (DMF). A FeCl3 to acetic acid ratio of 1:2 not only gave better control on polymer's molecular weight and its distribution, but also provided a rapid polymerization rate compared with any other molar ratio of FeCl3 to acetic acid. The polymerization rate increased with increasing temperature and the apparent activation energy was calculated to be 80.6 kJ·mol-1. In comparison with dimethyl sulfoxide, acetonitrile, cyclohexanone and ethyl acetate, DMF was considered to be the best solvent of the polymerization for its polarity. Analysis of 1H-NMR further confirmed the living nature of the polymerization. [ABSTRACT FROM AUTHOR]

Reverse atom transfer radical polymerization (RATRP) of acrylonitrile (AN) was carried out using azobisisobutyronitrile (AIBN) as initiator, ferric trichloride anhydrous (FeCl3)/lactic acid (LA) as catalyst system; a ratio of FeCl3/LA was 1:2 gave the best control. RATRP of AN with N,N-dimethylformamide (DMF) as solvent gave the moderate polymerization rate and the narrowest polydispersity index (PDI). When FeCl3 was replaced by CuBr2, RATRP of AN showed a longer induction period. When Cu was added to the CuBr2-based catalyst system, the induction period was reduced. 1H-NMR spectra of PAN verified the possibility of controlled/living polymerization for future chain extension. [ABSTRACT FROM AUTHOR]

Theoretical studies on the thermodynamic and kinetic properties of the reactions of Ti+ with sulfur transfer reagent SCO via the C═S bond activation pathway have been carried on using DFT/B3LYP method, general statistical thermodynamics, and Eyring transition state theory with Wigner correction. The relevant reactions include reaction 1 4Ti++1SCO →4IM1→4TS1→4IM2→4TiS++1CO, and reaction 2 4Ti++1SCO →4IM1→ CP →2IM2→2TiS++1CO in which the spin multiplicity changes from the quartet state to the doublet state in the crossing region. It is concluded that the increase of the temperature is favored to the reaction 1 process, since the equilibrium constants (K) rises from 0.566 × 10[P]-9 at 200 K to 0.109 × 100 at 1200 K, and the reaction rate constant (k) from 0.222 × 100 s[P]-1 at 200 K to 0.540 × 1011 s[P]-1 at 1200 K. Moreover, reaction 1 is endothermic, and non-spontaneous in the way the entropy increases, while reaction 2 is exothermic and spontaneous in the way their entropy decreases. The reaction path 2 is the energetically favorable channel, and its thermodynamic data change not largely with the rise of temperature. [ABSTRACT FROM AUTHOR]

The diffraction properties of volume holographic gratings are studied when the gratings are illuminated by an ultrashort pulsed beam with different polarization states. The developed coupled wave theory of Kogelnik is used. Considering the dispersion effect of the grating media, solutions for the diffracted and transmitted intensities, diffraction efficiencies and the bandwidths of the gratings are given in transmission volume holographic gratings and reflection volume holographic gratings. The bandwidths of the gratings are reduced by the dispersion effect of the grating media. They also have different influences on the diffraction of an ultrashort pulsed beam with different polarization states. For different values of the ratio of the spectral bandwidth of the input pulse to that of the grating, the changes of the spectral and temporal distributions of the diffracted intensities, as well as the diffraction efficiencies of the gratings are shown. [ABSTRACT FROM AUTHOR]

Rosa chinensis known commonly as the Chinese rose, is a member of the genus Rosa native to Southwest China. In this study, the complete chloroplast genome of R. chinensis was sequenced and analyzed. Structural analysis of the complete chloroplast (cp) genome of R. chinensis that exhibits a typical quadripartite circular structure with 155,097 bp in size, which contains a large single-copy region (LSC) of 85,911 bp, a small single-copy region (SSC) of 17,270 bp and a pair of inverted repeat (IR) regions of 25,958 bp in each one. The cp genome of R. chinensis contains 130 genes, including 85 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The phylogenetic Maximum-Likelihood (ML) analysis result shown that R. chinensis and Rosa odorata formed an independent clade with a 100% bootstrap support in phylogenetic relationship. [ABSTRACT FROM AUTHOR]

Based on Desli et al. (2003), this comment defines a stochastic frontier production model in a panel data framework. The firms can learn from their past errors to improve technical efficiency. This is done by introducing the inefficiency error term as an AR(p) process. The ways to estimate the production function and technical inefficiency are provided. [ABSTRACT FROM AUTHOR]