The"IPO-Plus": a new approach to privatization

Every approach to privatization entails tradeoffs. The chief advantage of case-by-case privatization -including sales for cash or initial public offerings (IPOs)- is efficiency. Case-by-case privatization generates revenues, gives shareholders control over managers, and provides access to capital and skills. But it is slow and does not promote widespread public participation. Voucher-based mass privatization programs, by contrast, are designed to promote equity in the distribution of wealth, through widespread participation. But they do not ensure efficiency because they may not generate revenues, bring in new capital or skills, or give shareholders control over managers. To promote equity and efficiency, the authors propose a new form of privatization -IPO-Plus- that incorporates key features of both case-by-case privatization and mass privatization. IPO-Plus promotes equity through widespread (but not mass) participation in privatization. It promotes efficiency by making privatization transparent, by fostering capital market development, and by creating independent financial institutions that would press companies to improve their financial performance. It relies not on vouchers but on the sale of low-priced public shares. It allows deferred payment for company shares as an incentive to purchase them as well as downwardly flexible share prices. Because the quality of the enterprises chosen for privatization is essential to the success of the IPO-Plus program, it is important that few enterprises targeted for IPO-Plus be published before the program is launched. This will motivate potential investors to join the program by setting up management companies, establishing public investment funds, and buying shares in them. IPO-Plus is more likely than mass privatization to create real owners. Investors in IPO-Plus are given a subsidy, but only in proportion to what they themselves choose to pay. The individual determines (up to a ceiling) how much to invest in the program. IPO-Plus is particularly appropriate where the objective is to encourage outside ownership rather than significant employee ownership. It encourages the emergence of market intermediaries and ensures the concentration of enterprise shares in investment funds. Outside ownership and concentration of share voting rights provide the basis for enterprise restructuring and economic growth.Payment Systems&Infrastructure,International Terrorism&Counterterrorism,Economic Theory&Research,Banks&Banking Reform,Municipal Financial Management,Banks&Banking Reform,Municipal Financial Management,Payment Systems&Infrastructure,Economic Theory&Research,International Terrorism&Counterterrorism

History of Cell Culture

From the ancient Romans, through the Middle Ages, to the late of the nineteenth century, the Aristotelian doctrine of spontaneous generation was one of the most basic laws. Even the invention of the microscope and investigations of Leeuwenhoek and Hook did not disprove the Aritostelian doctrine. Finally, in the eighteenth century, the spontaneous generation doctrine was laid by Louis Pasteur. Moreover, in the first decade of the eighteenth century, nucleus was observed in plant and animal tissues, and Virchow and other scientists presented the view that cells are formed via scission of preexisting cells. In the first decade of the twentieth century, Ross Harrison developed the first techniques of cell culture in vitro, and Burrows and Carrel improved Harrison\u27s cell cultures. In mid‐twentieth century, the basic principles for plant and animal cell cultures in vitro were developed, and human diploid cell lines were established. On the basis of knowledge about the cell cycle and gene expression regulation, the first therapeutic proteins were produced using mammalian cell cultures. The end of twentieth century and early twenty‐first century brought the progress in 3‐D cell culture technology and created the possibility of the tissue engineering and the regenerative medicine development

General Cytotoxicity and Its Application in Nanomaterial Analysis

The recent increasing interest in the use of different nanoparticles in biological and medical applications encouraged scientists to analyse their potential impact on biological systems. The biocompatibility analyses of novel materials for medical applications are conducted using quantitative and qualitative techniques collected by the International Standards Organization (ISO). The well-known assays, such as tetrazolium-based assays used for mitochondrial function monitoring, LDH for membrane permeability determination and neutral red uptake (NRU) describing lysosome function, need to be optimised due to specific properties of wide range of nanomaterials. Physicochemical properties of nanoparticles (NPs) such as size, composition, concentration, shape and surface (e.g., charge, coating, aspect ratio), as well as the cell type play a crucial role in determining the nanomaterial toxicity (also uptake pathway(s) of NPs). Different nanomaterials exhibit different cytotoxicity from relatively non-toxic hexagonal boron nitride to rutile TiO2 NPs that induce oxidative DNA damage in the absence of UV light. Finally, the results of the nanomedical analysis can be enriched by holographic microscopy that gives valuable information about the doubling time (DT), cell segmentation, track cell movement and changes in cell morphology. The results can be also completed by phenotype microarrays (PMs) and atomic force microscopy (AFM) techniques that fulfil experimental data

Phosphatidylserine Membrane Translocation in Human Spermatozoa: Topography in Membrane Domains and Relation to Cell Vitality

The complex structure of the human spermatozoa membrane comprises five topographic domains. Transmembrane asymmetry of the distribution of phospholipids including phosphatidylserine (PS) is considered a marker of cell activity. The objective of the study was to determine which cytomembrane domains of human spermatozoa are involved in PS membrane translocation and to identify the possible relationship of PS translocation with spermatozoa morphology and vitality. In normozoospermic semen of 35 donors, annexin-V labeling with fluorescein determined PS translocation. Propidium iodide staining distinguished between vital and dead spermatozoa. Three types of PS membrane translocation have been distinguished: (1) in the midpiece, (2) in the acrosomal part and (3) simultaneously in the midpiece and acrosomal part. In morphologically normal vital spermatozoa, PS translocation occurred in the midpiece but never in the equatorial region. In dead spermatozoa, simultaneous PS translocation in the midpiece and acrosomal part was most often observed. The difference between proportions of, respectively, vital and dead spermatozoa presenting PS translocation located in different domains was significant (P < 0.0001). In vital cells, there was no difference in PS translocation prevalence between morphologically normal and abnormal spermatozoa (P > 0.05). The strict relation of PS translocation to specific membrane domains indicates functional specificity. It seems doubtful to include this phenomenon in physiological mechanisms of elimination of abnormal spermatozoa

Pronuclear scoring as a predictor of embryo quality in in vitro fertilization program.

Many strategies have been proposed for the selection of viable embryos for transfer in human assisted reproduction. These have included morphological scoring criteria for 20, 28, 44 and 68 h after insemination. The embryo selection is based on morphology, degree of fragmentation and development to the 8-cell. All have shown some correlation with implantation. However, the overall success of these methods is still limited, with over 50% of all transferred embryos failing to implant. Pronuclear zygote morphology has gained much attention recently due to its positive value in predicting implantation and pregnancy. This prospective study involved 178 conventional IVF patients only. The key aspects of pronuclear scoring and namely the presence of a cytoplasmic halo were related to day 3 of development and morphology in a retrospective study. The Z-score and the presence/absence of a halo had significant effect on the rate of development on day 3 embryo. Low Z-score result in slow development and poor morphology. The absence of a halo also resulted in slow and poor development, low morphology, increased fragmentation

Few-Layered Hexagonal Boron Nitride: Functionalization, Nanocomposites, and Physicochemical and Biological Properties

Hexagonal boron nitride (h-BN) is an analogue of graphite called “white graphene.” In the structure of h-BN, B and N atoms substitute C atoms. The boron and nitrogen atoms are linked via strong B-N covalent bonds and form interlocking hexagonal rings. h-BN is used in different areas due to its interesting physical and chemical properties, e.g., in electronics as an insulator and in ceramics, resins, plastics, and paints. Therefore, boron nitride (BN) is also a popular inorganic compound in cosmetic industry (the highest BN concentration up to 25% can be found in eye shadow formulation). It is also widely used in dental cement production (for dental and orthodontic applications). Boron nitride seems to be suitable for biomedical applications; therefore, the cytotoxicity in vitro and in vivo observations of h-BN nanoplates and novel few-layered h-BN-based nanocomposites are still needed. The short-time studies confirm their low cytotoxicity and suggest that BN can be used as a novel drug delivery system; however, medical application needs additional verification in long-term studies

Musical Ratios in Sounds from the Human Cochlea

The physiological roots of music perception are a matter of long-lasting debate. Recently light on this problem has been shed by the study of otoacoustic emissions (OAEs), which are weak sounds generated by the inner ear following acoustic stimulation and, sometimes, even spontaneously. In the present study, a high-resolution time–frequency method called matching pursuit was applied to the OAEs recorded from the ears of 45 normal volunteers so that the component frequencies, amplitudes, latencies, and time-spans could be accurately determined. The method allowed us to find that, for each ear, the OAEs consisted of characteristic frequency patterns that we call resonant modes. Here we demonstrate that, on average, the frequency ratios of the resonant modes from all the cochleas studied possessed small integer ratios. The ratios are the same as those found by Pythagoras as being most musically pleasant and which form the basis of the Just tuning system. The statistical significance of the results was verified against a random distribution of ratios. As an explanatory model, there are attractive features in a recent theory that represents the cochlea as a surface acoustic wave resonator; in this situation the spacing between the rows of hearing receptors can create resonant cavities of defined lengths. By adjusting the geometry and the lengths of the resonant cavities, it is possible to generate the preferred frequency ratios we have found here. We conclude that musical perception might be related to specific geometrical and physiological properties of the cochlea

The Dimerization Domain in DapE Enzymes Is Required for Catalysis

The emergence of antibiotic-resistant bacterial strains underscores the importance of identifying new drug targets and developing new antimicrobial compounds. Lysine and meso-diaminopimelic acid are essential for protein production and bacterial peptidoglycan cell wall remodeling and are synthesized in bacteria by enzymes encoded within dap operon. Therefore dap enzymes may serve as excellent targets for developing a new class of antimicrobial agents. The dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) converts N-succinyl-L,L-diaminopimelic acid to L,Ldiaminopimelic acid and succinate. The enzyme is composed of catalytic and dimerization domains, and belongs to the M20 peptidase family. To understand the specific role of each domain of the enzyme we engineered dimerization domain deletion mutants of DapEs from Haemophilus influenzae and Vibrio cholerae, and characterized these proteins structurally and biochemically. No activity was observed for all deletion mutants. Structural comparisons of wild-type, inactive monomeric DapE enzymes with other M20 peptidases suggest that the dimerization domain is essential for DapE enzymatic activity. Structural analysis and molecular dynamics simulations indicate that removal of the dimerization domain increased the flexibility of a conserved active site loop that may provide critical interactions with the substrate

Structural Evidence of a Major Conformational Change Triggered by Substrate Binding in DapE Enzymes: Impact on the Catalytic Mechanism

The X-ray crystal structure of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase from Haemophilus influenzae (HiDapE) bound by the products of hydrolysis, succinic acid and l,l-DAP, was determined at 1.95 Å. Surprisingly, the structure bound to the products revealed that HiDapE undergoes a significant conformational change in which the catalytic domain rotates ∼50° and shifts ∼10.1 Å (as measured at the position of the Zn atoms) relative to the dimerization domain. This heretofore unobserved closed conformation revealed significant movements within the catalytic domain compared to that of wild-type HiDapE, which results in effectively closing off access to the dinuclear Zn(II) active site with the succinate carboxylate moiety bridging the dinculear Zn(II) cluster in a μ-1,3 fashion forming a bis(μ-carboxylato)dizinc(II) core with a Zn–Zn distance of 3.8 Å. Surprisingly, His194.B, which is located on the dimerization domain of the opposing chain ∼10.1 Å from the dinuclear Zn(II) active site, forms a hydrogen bond (2.9 Å) with the oxygen atom of succinic acid bound to Zn2, forming an oxyanion hole. As the closed structure forms upon substrate binding, the movement of His194.B by more than ∼10 Å is critical, based on site-directed mutagenesis data, for activation of the scissile carbonyl carbon of the substrate for nucleophilic attack by a hydroxide nucleophile. Employing the HiDapE product-bound structure as the starting point, a reverse engineering approach called product-based transition-state modeling provided structural models for each major catalytic step. These data provide insight into the catalytic reaction mechanism and also the future design of new, potent inhibitors of DapE enzymes