Exploring the direction on the environmental and business performance relationship at the firm level. Lessons from a literature review

The interest of scientists and companies in understanding the business implications of environmental investment is timely; however, a dilemma remains at the firm level: is the environment a “strategic competitive factor”, as in the “Porter point of view”, or is it a “luxury good”, as in the “Wagner point of view”? Our research contributes to this debate through a review of the papers published in scientific journals between 2000 and 2015 that discussed the direction of the relationship between the environmental and business performances of enterprises. The objectives of the research are: (a) to verify if there is an agreement in the scientific literature of the last 15 years about the “Porter–Wagner dilemma” when focusing at the firm level; (b) to underline the prevalent cause and effect directions of the relationship between environmental and business performance; and (c) to investigate the reasons for any disagreements in this topic among the scientists. The results show that the main agreement regards the positive bi-directional relationship, as a virtuous cyclic approach with mutual effects between business and environmental performance; nevertheless, more complex hypotheses emerge, such as nonlinear and/or conditional relationship, that need to be further explored. On the other hand, the Porter–Wagner dilemma remains, and the main reason for the non-agreement among scientists can be due to the several non-homogeneous variables considered in the analyses. Thereafter, as lesson for scientists, the priority is to share univocal methods to measure firms’ environmental and business performances

Toxin-Antitoxic Loci vapBC-1 and vapXD Contribute to Survival and Virulence in Nontypeable Haemophilus influenzae

Background: Nontypeable Haemophilus influenzae (NTHi) is a significant human pathogen responsible for respiratory tract infections and the most common cause of recurrent otitis media. Type II toxin-antitoxin (TA) systems are genetic elements that code for a stable protein toxin and a labile antitoxin that are thought to be involved in metabolic regulation of bacteria by enabling a switch to a dormant state under stress conditions. The contribution to infection persistence of the NTHi TA loci vapBC-1 and vapXD was examined in this study. Results: Deletions in vapBC-1, vapXD and vapBC-1 vapXD significantly decreased the survival of NTHi co-cultured with primary human respiratory tissue at the air-liquid interface and in the chinchilla model of otitis media. The TA deletions did not affect the growth dynamics of the mutants in rich media, their ultra-structural morphology, or display appreciable synergy during NTHi infections. The toxin and antitoxin proteins of both pairs heterodimerized in vivo. Consistent with our previous findings regarding the VapC-1 toxin, the NTHi VapD toxin also displayed ribonuclease activity. Conclusions: We conclude that the vapBC-1 and vapXD TA loci enhance NTHi survival and virulence during infection in vitro and in vivo using a mechanism of mRNA cleavage, and that these conserved TA pairs represent new targets for the prophylaxis and therapy of otitis media and other NTHi-caused mucosal diseases

Ergodicity of the underdamped mean-field Langevin dynamics

We study the long time behavior of an underdamped mean-field Langevin (MFL) equation, and provide a general convergence as well as an exponential convergence rate result under different conditions. The results on the MFL equation can be applied to study the convergence of the Hamiltonian gradient descent algorithm for the overparametrized optimization. We then provide a numerical example of the algorithm to train a generative adversarial networks (GAN).Comment: 29 pages, 2 figure

Toxin-Antitoxic Loci vapBC-1 and vapXD Contribute to Survival and Virulence in Nontypeable Haemophilus influenzae

Background: Nontypeable Haemophilus influenzae (NTHi) is a significant human pathogen responsible for respiratory tract infections and the most common cause of recurrent otitis media. Type II toxin-antitoxin (TA) systems are genetic elements that code for a stable protein toxin and a labile antitoxin that are thought to be involved in metabolic regulation of bacteria by enabling a switch to a dormant state under stress conditions. The contribution to infection persistence of the NTHi TA loci vapBC-1 and vapXD was examined in this study. Results: Deletions in vapBC-1, vapXD and vapBC-1 vapXD significantly decreased the survival of NTHi co-cultured with primary human respiratory tissue at the air-liquid interface and in the chinchilla model of otitis media. The TA deletions did not affect the growth dynamics of the mutants in rich media, their ultra-structural morphology, or display appreciable synergy during NTHi infections. The toxin and antitoxin proteins of both pairs heterodimerized in vivo. Consistent with our previous findings regarding the VapC-1 toxin, the NTHi VapD toxin also displayed ribonuclease activity. Conclusions: We conclude that the vapBC-1 and vapXD TA loci enhance NTHi survival and virulence during infection in vitro and in vivo using a mechanism of mRNA cleavage, and that these conserved TA pairs represent new targets for the prophylaxis and therapy of otitis media and other NTHi-caused mucosal diseases

Science and Engineering Serials: Issues and Challenges in the Electronic Environment

Pricing Issues: The Core Problem. Subscription Price Increases. Fluctuations in the Foreign Exchange Rate. ISI Impact Factors, Journal Quality, and Cost-Effectiveness. Questions of Content, Archiving, and Access.. Conclusion. Reference Notes

Reconciling the Diversity and Uniformity of Galactic Rotation Curves with Self-Interacting Dark Matter

Galactic rotation curves exhibit diverse behavior in the inner regions, while obeying an organizing principle, i.e., they can be approximately described by a radial acceleration relation or the Modified Newtonian Dynamics phenomenology. We analyze the rotation curve data from the SPARC sample, and explicitly demonstrate that both the diversity and uniformity are naturally reproduced in a hierarchical structure formation model with the addition of dark matter self-interactions. The required concentrations of the dark matter halos are fully consistent with the concentration-mass relation predicted by the Planck cosmological model. The inferred stellar mass-to-light ($3.6 \mu m$) ratios scatter around $0.5 M_\odot/L_\odot$, as expected from population synthesis models, leading to a tight radial acceleration relation and baryonic Tully-Fisher relation. The inferred stellar-halo mass relation is consistent with the expectations from abundance matching. These results indicate that the inner dark matter halos of galaxies are thermalized due to the self-interactions of dark matter particles.Comment: Main text: 10 pages and 3 figures. Supplementary Materials: 47 pages, 2 tables and 5 figures including detailed fits to 135 galaxie

Stability of active ingredients of traditional Chinese medicine (TCM).

Studies on stability of active ingredients are fundamental and critical for the rational development of Traditional Chinese Medicine (TCM) in view of its modernization and worldwide use. The stability of both active and marker constituents of plants used in TCM is reviewed for the first time. More than 100 papers, mostly written in Chinese, have been reviewed. Studies concerning plant constituents were analyzed according to their chemical classification of active ingredients. In addition, several crude drugs of animal origin are also reported. Stability of active ingredients is summarized during extraction and/or storage of the herbal drug preparations, and under stress conditions (pH, temperature, solvents, light, and humidity) and in the presence of preservatives, antioxidants, and metals

Numerical simulation of decomposition of Polymer Nano-composites: Investigation of the Influence of the Char Structure

In recent years, nano-particles such as nano-clays, carbon nanotubes and graphenes have been extensively used in flame-retardant polymeric materials. The surface char layer formed in combustion acts as protective barriers that limit the heat transfer into the unpyrolysed polymer and volatilization of combustible degradation products and diffusion of oxygen into the material. A numerical simulation tool Thermakin is used to simulate the thermal decomposition of the neat polymers (polypropylene (PP), Acrylonitrile Butadiene Styrene (ABS)) and corresponding nano-composites (PP/multi-walled carbon nanotube (PP/MWCNT) and ABS/ graphene nano-sheets /NiFe-layered double hydroxide hybrid (ABS/GNS-LDH) in cone calorimetry experiments. PP/MWCNT forms a porous network while ABS/GNS-LDH forms a compact, dense char layer during combustion. With appropriate input parameters, the heat release rates (or mass loss rates) are predicted very well. Finally, the effect of input parameters on model outputs are discussed