LL Model Research Articles

Ideal-types of experimentation practices in agricultural Living Labs: Various appropriations of an open innovation model

CONTEXTThe “Living Lab” (LL) model of innovation practices is increasingly applied and strongly supported by innovation policies in the agricultural sector. But while the main principles of LLs imply specific approaches to collectively implementing open innovation processes, few studies have developed an understanding of the different ways of doing so, in relation to the experimental practices on which they rely. While the specificities of agricultural LLs are beginning to be described, little is known about how they more particularly reconfigure experimentation in agricultural innovation systems. OBJECTIVEThe purpose of this paper is to investigate the diversity of experimentation practices in agricultural LLs. It looks at how these practices correspond to different contextualized appropriations of an open innovation model, as translated into key principles for LL implementation. METHODSFirst, we produced an analytical framework that combines the principles of the LL model as described in the LL literature with generic dimensions of experimentation as analyzed in Science and Technology Studies. Second, we used this framework to analyze the diversity of experimentation practices in eighteen cases of LLs in the agricultural and food sectors. Cases were analyzed via two approaches: 1- three small and recent ongoing LLs located in France were studied during a one-year immersive observation; and 2- a collection of 15 other cases (identified in scientific and technical literature, each case corresponding to experiments that are forms of appropriation of the LL model of innovation, sometimes in several similar LLs) were analyzed, mostly based on scientific papers (describing the LLs or their outcomes), technical documents and available information such as videos online, with additional visits and discussions with LL actors for a subset of cases. RESULTS AND CONCLUSIONSOur results enable us to characterize three ideal-types of experimentation practices within agricultural LLs: 1- experimentation as a game of creativity in a predefined space; 2- experimentation as a progressive contextual adaptation for innovation adoption; and 3- experimentation as a catalyst for long-term local collective action. Each ideal-type corresponds to a particular combination of ways of (i) controlling what happens within the experimentation space, (ii) defining a perimeter for experimentation, (iii) integrating plural knowledge in problematization, and (iv) integrating various actors' evaluations of experiments. Beyond a clear distinction among ideal-types, appropriations of the LL model reveal different ways of anchoring the experimental process in an explicit temporality and situation, and of considering the construction of the LL itself as experimental and open-ended. SIGNIFICANCEOur analytical framework opens a new way to distinguish between various experimentation practices claiming to develop open innovation processes in agriculture. The three ideal-types that we have identified show the need to pay attention to the relation between collective experimentation practices and the LL expected outcomes.

Comparative analysis of morphological changes in renal tissue under the influence of light desynchronosis

AIM: To compare morphological changes that occur in renal tissue, as a result of exposure to various models of light desynchronosis.
 MATERIAL AND METHODS: This study was conducted on 48 white rats. Three experimental groups were exposed to light for 21 days. The LL (0:24) model was studied in the first group, while the LD 18:6 and 12:10 models were studied in the second and third groups, respectively. The control group was kept in natural conditions all through the experiment.
 The animals were placed under anesthesia with a combination of Telazol (ZoetisInc, USA) and Xylanit (Nita-farm, Russia). Afterward, their right kidney was removed. The samples obtained were prepared according to the standard method. Statistical processing was performed using the package of applied statistical programs "STATISTICA 10" (StatSoft , USA).
 RESULTS: Morphological disorders of the renal tissue were observed in the three experimental groups. In the first experimental group, there was a significant segmentation of the glomeruli, accompanied by dystrophic changes in the renal tubules. In the second experimental group, glomerular segmentation was more pronounced. In the renal tissue of animals of the third experimental group, the disorders were highly observable, and the sclerotized segment is noted. Changes in morphometric indicators were significant across all experimental groups.
 CONCLUSION: Desynchronosis harms the renal tissue by causing changes in its morphology. The most significant disorders characterized by sclerosis were observed in the kidneys of animals in the third experimental group.

Optimized design and investigation about propulsion of bionic Tandem undulating fins I: Effect of phase difference

Motivated by the excellent maneuverability and high efficiency of the undulation fishes, a multi-fins propulsor was provided in this article and the propulsion performance was attempted to be improved by taking advantage of the interaction between the tandem fins. The effects of the wave-number and the phase difference were studied numerically. The results showed that the thrust force was enhanced significantly by introducing a fin with wave-numbers of 0.5 at the expense of propulsion efficiency. The vortices induced by the anterior and posterior fins were merged or offset, which depended on the phase difference between the tandem fins. The interaction of vortices led to the variation of thrust force with the phase difference in a sinusoidal curve. With the phase difference around the crest, the propulsion performance of tandem fins was improved clearly. Considering the thrust, lateral force and efficiency, the LL model where both the fin wave-numbers are set to be 1.0 is suitable for the cruising motion of the aquatic vehicle, and the SS model where the wave-numbers are adjusted to 0.5 is beneficial to the fast maneuver. The present results provided a theoretical basis for the design of aquatic multi-fin propulsion robots to meet different task requirements.

Staggering Effects in Nuclear and Molecular Spectra

It is shown that the recently observed AI = 2 staggering seen in superdeformed nuclear bands is also occurring in certain electronically excited rotational bands of diatomic molecules, in which it is attributed to interband interactions (bandcrossings). In addition, a AI = 1 staggering effect (i.e. a relative displacement of the levels with even angular momentum I with respect to the levels of the same band with odd /) is seen in molecular bands free from AI = 2 staggering (i.e. free from interband interactions/bandcrossings). The magnitude of the AI = 1 staggering is found to be constant as a function of 7, in agreement with the predictions of algebraic models (u(ll) model, u(16) model, Vector Boson Model) used for the description of octupole nuclear bands, i.e. bands corresponding to pear-like shapes, suggesting that the presence of AI = 1 staggering in rotational bands of diatomic molecules could be attributed in general to the inequality of the masses of the two atoms of which the molecule is composed. The existence of the AI = 1 staggering effect is corroborated by the fact that separate Dunham expansions for the even levels and the odd levels of such bands give similar but different parameter sets.

Association between the promoter region of serotonin transporter polymorphisms and recurrent aphthous stomatitis: A meta-analysis

ObjectivesTo assess the association between the promoter region of serotonin transporter (5-HTTLPR) gene polymorphism and recurrent aphthous stomatitis (RAS) occurrence. DesignsWe performed the meta-analysis to determine the potential association between 5-HTTLPR polymorphism and RAS. We retrieved revelant studies from the PubMed, Scopus, Embase, Web of Science and Cochrane Library databases up to January 2019. Data were analyzed for odd ratios with 95% confidence intervals using Revman 5.3 software. ResultsThere were 4 studies in the meta-analysis, which included 291 RAS cases and 286 controls. It indicated a substantially augmented threat of RAS with respect to S vs. L (P = 0.005), SS vs. LL+LS (P ＜ 0.0001) and SS vs. LL models (P ＜ 0.00001), respectively. No heterogeneity was found between studies in all comparisons. ConclusionsThe current meta-analysis provides evidence to prove the association between 5-HTTLPR polymorphism and RAS. Further studies should be performed to clarify the biochemical function and pathological role of 5-HTTLPR in the risk of RAS.

The middle-out approach: assessing models of legal governance in data protection, artificial intelligence, and the Web of Data

ABSTRACTAll models of legal governance and most regulatory options have to do with ‘top-down’ solutions as an essential ingredient of the approach. Such models may include ‘bottom-up’ forms of self-regulation, such as in forms of ex post regulation, or unenforced self-regulation. This paper focuses on what lies in between such top-down and bottom-up approaches, namely, the middle-out interface of the analysis. Within the EU legal framework, this middle-out layer is mainly associated with forms of co-regulation, as defined by Recital 44 of the 2010 AVMS Directive and Article 5(2) of the GDPR. However, there are also additional models on how we should grasp the middle-out layer of legal regulation, as shown by the debates on the governance of AI and the Web of Data. For example, the debates on issues such as monitored self-regulation, coordination mechanisms for good AI governance, and ‘wind-rose’ models for the Web of Data make it clear that co-regulation is not the only alternative to both bottom-up and top-down approaches. From a methodological viewpoint, the middle-out approach sheds light on three different kinds of issues that regard (i) how to strike a balance between multiple regulatory systems; (ii) how to align primary and secondary rules of the law; and (iii) how to properly coordinate bottom-up and top-down policy choices. The increasing complexity of technological regulation recommends new models of governance that revolve around this middle-out analytical ground.

Innovation in the management of lessons learned in an IT project with the adoption of social media

This research explores the gap in the management of lessons learned (MLL) in an Information Technology project (IT), validating a model (named Target) with the support of a wiki platform in a medium-sized company in the IT industry. This model supports the following MLL processes: awareness, collection, verification, storage, dissemination and reuse. This study adopts the paradigm of the Design Science Research and the Technical Action Research method to instantiate the Target model in the implementation phase of an IT project. The theoretical contribution lies in the practical utility of an LL model, which was validated in the field promoting innovation in the MLL. The practical implications can be seen in the company's learning to introduce the MLL, improve design productivity, increase employee collaboration and better disseminate knowledge.

Zero-dimensional limit of the two-dimensional Lugiato-Lefever equation

We study effects of tight harmonic-oscillator confinement on the electromagnetic field in a laser cavity by solving the two-dimensional Lugiato-Lefever (2D LL) equation, taking into account self- focusing or defocusing nonlinearity, losses, pump, and the trapping potential. Tightly confined (quasi-zero-dimensional) optical modes (pixels), produced by this model, are analyzed by means of the variational approximation, which provides a qualitative picture of the ensuing phenomena. This is followed by systematic simulations of the time-dependent 2D LL equation, which reveal the shape, stability, and dynamical behavior of the resulting localized patterns. In this way, we produce stability diagrams for the expected pixels. Then, we consider the LL model with the vortical pump, showing that it can produce stable pixels with embedded vorticity (vortex solitons) in remarkably broad sta- bility areas. Alongside confined vortices with the simple single-ring structure, in the latter case the LL model gives rise to stable multi-ring states, with a spiral phase field. In addition to the numeri- cal results, a qualitatively correct description of the vortex solitons is provided by the Thomas-Fermi approximation.

Association of MBL2 exon1 polymorphisms with high-risk human papillomavirus infection and cervical cancers: a meta-analysis

High-risk human papillomavirus (HR-HPV) infection is the main known cause of cervical cancer. Mannose-binding lectin (MBL) is a recognition molecule that mediates phagocytosis and activates complement. We performed a meta-analysis to investigate the association of MBL-2 functional polymorphisms with HPV infection and cervical cancer (CC). The meta-analyses indicated an association between the MBL2 exon 1 polymorphisms and susceptibility to HPV infection in the recessive model (OO vs. AA+AO, p=0.042, 95% CI 1.02-3.15), and O/O vs. A/A mode (P=0.023, 95% CI 1.10-3.40) in Caucasian. Meanwhile, there was a significant association between MBL2 exon 1 polymorphisms and cervical cancer risk in AO vs. AA model (p=0.035, 95% CI 1.03-2.26), and Allelic model (O vs. A, p=0.022, 95% CI 1.05-1.96) as compared to HR-HPV-infected patients with CC vs. healthy controls in Caucasian. In addition, no an association was observed between MBL2 -550 H/L and -221 X/Y polymorphisms and HPV infection among Caucasians, but we found an association between the MBL2 -550 H/L polymorphism and susceptibility to HR-HPV infection in recessive model (HH vs. LL+LH, p=0.003, 95% CI 1.18-2.23), HH vs. LL model (p=0.021, 95% CI 1.07-2.19), and allelic model(H vs. L, p=0.042, 95% CI 1.01-1.40) in Asians. Collectively, we suggest that the MBL2 gene exon1 polymorphisms are associated with increased risk of high-risk HPV infection and cervical cancer development among Caucasians. Additionally, no significant association was found between the MBL2 -550 H/L or -221 X/Y polymorphisms and HPV infection in Caucasians, but there may be potential links in Asians.

Fusion with human lung cancer cells elongates the life span of human umbilical endothelial cells and enhances the anti-tumor immunity.

Human umbilical endothelial cells (HUVECs) have been proved as an effective whole-cell vaccine inhibiting tumor angiogenesis. However, HUVECs divide a very limited number of passages before entering replicative senescence, which limits its application for clinical situation. Here, we fused HUVECs with human pulmonary adenocarcinoma cell line A549s and investigated the anti-tumor immunity of the hybrids against mice Lewis lung cancer. HUVECs were fused with A549s using polyethylene glycol and were sorted by flow cytometry. The fusion cells (HUVEC-A549s) were confirmed by testing the expression of telomerase and VE-cadherin, the senescence-associated β-galactosidase activity, and tube formation ability. HUVEC-A549s were then irradiated and injected into the C57BL/6 mice of protective, therapeutic, and metastatic models. The mechanism of the anti-tumor immunity was explored by analyzing mice sera, spleen T lymphocytes, tumor microenvironment, and histological changes. HUVEC-A549s coexpressed tumor and endothelial markers and maintained the vascular function of tube forming at passage 30 without showing signs of senescence. HUVEC-A549s could induce protective and therapeutic anti-tumor activity for LL(2) model and presented stronger activity against metastasis than HUVECs. Both humoral and cellular immunity were participated in the anti-angiogenic activity, as HUVECs-neutralizing IgG and HUVECs-toxic lymphocytes were increased. Angiogenic mediators (VEGF and TGF-β) and tumor microenvironment cells MDSCs and Tregs were also diminished. Our findings might provide a novel strategy for HUVECs-related immunotherapy, and this vaccine requires lower culture condition than primary HUVECs while enhancing the anti-tumor immunity.

Modeling of photodegradation kinetics of aromatic pollutants in water matrix

In this study photodegradation kinetics of aromatic pollutants in water was simulated by combining two approaches: kinetic modeling and structural-relationship modeling. Semiempirical model based on Lambert's law (“LL model”) was used to determine quantum yields (Φ) of 28 single-benzene ring pollutants. QSAR/QSPR modeling, using Genetic Algorithm (GA) and multiple linear regression analysis (MLRA) to select the descriptors and to generate the best correlation models, was applied to establish structure–property relationship of molar absorption coefficient (ɛ) and quantum yield (Φ). In both cases the most predictive models consistent of 4 variables, i.e. descriptors, possessing the good ratios of the number of variables and the predictive ability to avoid overfitting. It was found that ɛ depends on the overall number of bonds, particular atom-centered fragment related to substituents possessing double and single bonded heteroatoms (O or N) to C atom, as well as the shape and size of the molecule and polarizibility. Molecular symmetry was shown as the most influential factor toward Φ. The applied GA-MLRA approach using DRAGON generated descriptors yielded good results, which was also confirmed by external validation. “LL model” simulation for two additional single-benzene ring pollutants, using predicted Φ and ɛ by QSAR/QSPR, slightly deviated from the experimental results (RMSD ≤ 0.75%).

Location Leveling

Location based service (LBS) is an appealing technology in the pervasive mobile computing environment. In this environment, the answer to a location dependent query depends on the location of the mobile user. However, the location granularity to which the mobile unit is bound by a location service may differ from that stored in the content provider’s database. As a result, a location granularity mismatch occurs. The authors propose a general software architecture, location leveling, to solve this problem. As their layered location leveling solution is independent of the support provided by the wireless provider and the content provider, it is flexible enough to be used by any. The location leveling (ll) model can be implemented as an independent agent or broker in the middleware layer. The proposed approach is developed with solid theoretical foundation found in previous multidimensional data modeling studies.

Adsorption of polycyclic aromatic hydrocarbons (PAHs) on Rhizopus oryzae cell walls: Application of cosolvent models for validating the cell wall-water partition coefficient

The cell wall-cosolvent partition coefficients (Km) of polycyclic aromatic hydrocarbons (PAHs) were determined for Rhizopus oryzae cell walls by controlling the volume fraction of methanol (f) ranging from 0.1 to 0.5. Five cosolvent models were employed for extrapolating the cell wall-water partition coefficients (Kw) in pure water. The extrapolated Kw values of four PAHs on R. oryzae cell walls were ranged from 2.9 to 5.1. Comparison of various Kw values of pyrene generated from extrapolation and the QSPR model, together with predicted different (PD), mean percentage deviations (MPD), and root mean square errors (RSE), revealed that the performance of the LL and Bayesian models were the best among all five tested cosolvent models. This study suggests that R. oryzae cell walls play an important role in the partitioning of PAHs during bioremediation because of the high Kw of fungal cell walls.

Liquid−Liquid and Vapor−Liquid−Liquid Equilibrium of the 4-Methyl-2-pentanone + 2-Butanol + Water System

Liquid−liquid equilibrium (LLE) data have been measured for the ternary system 4-methyl-2 pentanone + 2-butanol + water at (283.15 and 333.15) K. Experimental results show a low influence of temperature on immiscibility zone size and shape. The NRTL and UNIQUAC models were applied to correlate the ternary system at (283.15 and 333.15) K, and the interaction parameters obtained from both models successfully correlated the equilibrium compositions. Moreover, isobaric vapor−liquid−liquid equilibrium (VLLE) is measured for this ternary mixture at 101.3 kPa. The experimental data were compared with the estimation from LLE binary interaction parameters using NRTL and UNIQUAC models, as well as the correlation obtained with these models. The prediction of the UNIFAC LL model has been obtained and compared with the previous results, to confirm the necessity to obtain experimental data in this type of system.

Accuracy of Consumer Grade Bioelectrical Impedance Analysis Devices Compared to Air Displacement Plethysmography

The purpose of this study was to examine the accuracy of percent body fat estimates from seven different bioelectrical impedance analysis (BIA) models and a seven-site skin fold formula (SKF) compared with air displacement plethysmography (ADP) in females. Eighty-two female volunteers ranging from 19-67 years (31.96 ± 1.39) enrolled in this study. Body composition was assessed by seven site skin folds (SKF), ADP, Tetrapolar BIA (TBIA), and five consumer grade BIA devices: finger to finger (FF), hand to hand (HH) and three different leg to leg (LL1, LL2, LL3) models. In addition, LL3 was analyzed using the athletic (LL3a) and non-athletic modes (LL3b). The Institutional Review Board for Human Subjects at Eastern Washington University approved this study. The participants represented a wide range of percentage body fat (BF) as assessed by ADP (8.40 to 47.10, mean = 26.15 ± 0.93 SEE). No difference in the estimated percent body fat was found between ADP and SKF, TBIA, FF, HH, LL1, LL2, LL3a, and LL3b (r=0.862, 0.553, 0.775, 0.771, 0.765, 0.791, 0.798, 0.796 respectively; P<0.001). Bland-Altman plots of the differences between % fat by ADP and BIA versus average % fat by the two methods showed no systematic differences for SKF and the seven BIA models (mean differences ± SD : SKF, 1.92 ± 4.25; TBIA, 0.73 ± 7.3; FF, -1.55 ± 5.34, HH, 1.37 ± 5.35; LL1, -4.70 ± 5.40, LL2, -3.72 ± 5.12 and LL3a, 1.70 ± 5.07; LL3b, -6.11 ± 31.40 p<0.05). Skin fold measures were found to be the most reliable field method of estimating body composition. Of the BIA machines tested, the strongest relationship was found in the LL models with the LL3 in athletic mode (LL3a) being the most reliable. For the more affordable models, the LL2 was the most reliable compared to ADP.

Unobserved Component Model for Forecasting Polish Inflation

This paper aims to use the local level models with GARCH and SV errors to predict Polish inflation. The series to be forecast, measured monthly, is consumer price index (CPI) in Poland during 1992-2008. We selected three forecasting models i.e. LL-GARCH(1,1) with Normal or Student errors and LL-SV. A simple AR(2)-SV model is used as a benchmark to assess the accuracy of prediction. The presented results indicate, that there is no clear advantage of LL models in forecasting Polish inflation over standard AR(2)-SV model, although all the models give satisfactory results.

Micromagnetic simulation of the magnetic spectrum of two magnetostatic coupled ferromagnetic stripes

The magnetic spectra of two magnetostatic coupled ferromagnetic stripes with different distances were investigated by the three-dimensional object oriented micromagnetic framework (OOMMF) code. The studied systems exhibit two resonance peaks. The higher peak can be identified with the bulk mode predicted by the macroscopic LL model. The lower peak originates from edge magnetic moments. Influence of magnetostatic interaction on the two resonance models was studied in detail. As the distance between two stripes increases, the magnetic spectrum of two stripes is close to the case of a single stripe.

Accuracy of Consumer Grade Bioelectrical Impedance Analysis Devices Compared to Air Displacement Plethysmography

PURPOSE: The aim of this study was to compare body composition measures between consumer grade models of bioelectrical impedance analysis (BIA), skin folds and a criterion methodology, air displacement plethysmography (ADP). METHODS: Eighty-two female volunteers ranging from 19–67 years (31.96 ± 1.39) enrolled in this study. Body composition was assessed by seven site skin folds (SKF), ADP, Tetrapolar BIA (TBIA), and five consumer grade BIA devices: finger to finger (FF), hand to hand (HH) and three different leg to leg (LL1, LL2, LL3) models. In addition, LL3 was analyzed using the athletic (LL3a) and non-athletic modes (LL3b). This study was approved by the Institutional Review Board for Human Subjects at Eastern Washington University. RESULTS: The participants represented a wide range of percentage body fat (BF) as assessed by ADP (8.40 to 47.10, mean = 26.15 ± 0.93 SEE). No difference in estimating percent body fat was found between ADP and SKF, TBIA, FF, HH, LL1, LL2 and LL3a (r=0.862, 0.553, 0.775, 0.771, 0.765, 0.791, 0.798, respectively; p<0.001). A significant difference in estimating percent body fat was found between ADP and LL3b (r=0.051, p<0.001, SEE = 8.42). Bland-Altman plots of the differences between % fat by ADP and BIA versus average % fat by the two methods showed no systematic differences for SKF and six BIA models (mean differences ± SD: SKF, 1.92 ± 4.25; TBIA, 0.73 ± 7.3; FF, −1.55 ± 5.34, HH, 1.37 ± 5.35; LL1, −4.70 ± 5.40, LL2, −3.72 ±5.12 andLL3a, 1.70 ± 5.07; p<0.05). Systematic differences were found for the LL3b BIA model (mean difference ± SD = −6.11 ±31.40). CONCLUSIONS: Skin fold measures were found to be the most reliable simple method of estimating body composition. Of the all BIA machines tested, the strongest relationship was found in the LL models with the LL3 in athletic mode being the most reliable. For the most affordable models, the LL2 model was the most reliable when comparing to ADP.

Assessing Validity of the Basel II Model in Measuring Risk of Credit Portfolios

The paper assesses validity of credit loss distributions of client portfolios calculated by means of the Basel II model. The assessment method consists in parallel calculations the same distributions by means of exact probabilistic formulae. We found that Basel II model ensures correct assessments of credit loss distributions for medium and large portfolios of thirty or more one-period credits (credits without intermediate interest etc. payments). For small portfolios and individual one-period credits assessments of Basel II model are rough or extremely rough. Basel II model undervalues credit risk of portfolios of multi-period credits (credits with active period covering several years and intermediate payments). Exact models are more complex that Base ll model, but perfectly available for quick computer calculations. They can be used in bank practice ensuring flexible assessments of credit risk.

Assessing Validity and Accuracy of the Basel II Model in Measuring Credit Risks of Individual Borrowers and Credit Portfolios

The paper assesses the validity and accuracy of measuring risks of individual borrowers and credit portfolios by means of the Basel II credit risk model. The assessment method consists in parallel estimation of the same risks by means of exact probabilistic models. We find that the Basel II model gives a correct estimate of the possible credit losses for medium and large portfolios of thirty or more one-period credits (credits without intermediate payments - interest etc.). For small portfolios and individual one-period credits the estimates of the Basel II model are inaccurate or very inaccurate. The model undervalues the credit risk of portfolios of multi-period credits (credits with active period covering several years and intermediate payments). This study presents an alternative view on some of the major Basel II concepts, such as correlation and probability of default (PD). This can lead to a better understanding and more flexible use of those concepts in assessing credit risks. The exact models are more complicated than the Base ll model, but quite suitable for rapid computer calculations. They can be used in bank practice, providing flexible assessments of credit risk.