Initial Public Offerings: The Case Of Health Maintenance Organizations (HMOs)

Objective: To determine whether the returns of initial public offerings (IPOs) of HMOs in the days following issue are similar to the return behavior of IPOs in previous studies.Data Source: The Center for Research in Security Prices (CRSP) tapes compiled by the Graduate School of Business at the University of Chicago provides daily stock prices, holding period returns, and other data pertinent to research in traded securities.Study Design: The hypothesis to be tested is whether the mean excess return surrounding the offer date is equal to zero.  To adjust the initial returns of the IPOs for overall market movements, Standard & Poor’s Composite Index (S&P 500) was selected as the proxy for the market in general.  We compute the long-run performance for the HMOs and compare that return to the S&P 500 and the CRSP AMEX/NYSE equally-weighted and value-weighted indices.Data Collection/Extraction Method:  We matched for-profit HMOs listed in the National Directory of Managed & Integrated Care Organizations to the commitment offerings reported by Securities Data Corporation to the same firms on the daily CRSP tapes.  This left 49 firms that went public between 1971 through 1997.  The Wharton Research and Data Services External (WRDSX) was used for data extraction and SAS was used for statistical analysis.Principal Findings: IPOs of HMOs are underpriced and demonstrate abnormal returns.  The average initial return on these IPOs is less than that of the average in the United States.  On a long-run performance basis, they performed better than the broad market indices.Conclusions:  Returns follow a similar pattern as do IPOs in general except for the long-run performance.  This needs further research as well as a comparison of performance before and after going public in cases where accounting data is available

Identity and Toxicity of FUsarium Species Isolated from Wilted Chickpea

Four cultures of fungi, identified as Fusarium oxysporum f. sp. ciceris, were received from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), India. The cultures were race 1, a race designated as V2, race 2, and an isolate from Jabalpur which, on geographical evidence, was probably race 4, the races being defined on the basis of the reaction to them of a set of differential cultivars of the host. A further isolate, also identified as Fusarium oxysporum f. sp. ciceris, but of unknown race was received from the Thal region of Pakistan. Culture filtrates of all the isolates, grown on a defined medium, were toxic to cells of chickpea leaflets, separated enzymatically from the plant, but filtrates of the Thal isolate were the most toxic. Isolate toxicity was affected by incubation temperature and time, the maximum toxicity for the Thal isolate being 72 units activity ml-1 cultural filtrate when it was grown at 20ºC for 12 days but only 7 units activity ml-1 when grown at 30ºC for the same period. When ribosomal DNA sequences of the four ICRISAT isolates were compared, those of race 1 and V2 were identical for all 392 bps, suggesting that V2 is a variant of race 1. The Jabalpur isolate was a 99% (390/392 bps) match with race 1 and V2 and race 2 was a 97% (391/400 bps) match with race 1 and V2. Although the Thal isolate gave a 99% match with the race 1 and V2 for the first 262 bps (one gap) and a 89% match (59/66 bps) for bps 338–403, there was considerable divergence in the region from 263 to 337 bps. Similar results were obtained when the Thal isolate was matched with race 2 and 4. The four ICRISAT isolates were confirmed as Fusarium oxysporum but various formae speciales in the GenBank database such as vasinfectum and vanillae were equally well matched. No sequence for F. oxysporum f. sp. ciceris was present in the GenBank database. In contrast, the Thal isolate gave an almost exact match with Fusarium acutatum (407/408 bps) and the morphology of the Thal isolate, when viewed under the microscope, accorded well with the description of F. acutatum given in the literature

Relating pseudospin and spin symmetries through charge conjugation and chiral transformations: the case of the relativistic harmonic oscillator

We solve the generalized relativistic harmonic oscillator in 1+1 dimensions, i.e., including a linear pseudoscalar potential and quadratic scalar and vector potentials which have equal or opposite signs. We consider positive and negative quadratic potentials and discuss in detail their bound-state solutions for fermions and antifermions. The main features of these bound states are the same as the ones of the generalized three-dimensional relativistic harmonic oscillator bound states. The solutions found for zero pseudoscalar potential are related to the spin and pseudospin symmetry of the Dirac equation in 3+1 dimensions. We show how the charge conjugation and $\gamma^5$ chiral transformations relate the several spectra obtained and find that for massless particles the spin and pseudospin symmetry related problems have the same spectrum, but different spinor solutions. Finally, we establish a relation of the solutions found with single-particle states of nuclei described by relativistic mean-field theories with scalar, vector and isoscalar tensor interactions and discuss the conditions in which one may have both nucleon and antinucleon bound states.Comment: 33 pages, 10 figures, uses revtex macro

Quantitative nanohistological investigation of scleroderma: An atomic force microscopy-based approach to disease characterization

Scleroderma (or systemic sclerosis, SSc) is a disease caused by excess crosslinking of collagen. The skin stiffens and becomes painful, while internally, organ function can be compromised by the less elastic collagen. Diagnosis of SSc is often only possible in advanced cases by which treatment time is limited. A more detailed analysis of SSc may provide better future treatment options and information of disease progression. Recently, the histological stain picrosirius red showing collagen register has been combined with atomic force microscopy (AFM) to study SSc. Skin from healthy individuals and SSc patients was biopsied, stained and studied using AFM. By investigating the crosslinking of collagen at a smaller hierarchical stage, the effects of SSc were more pronounced. Changes in morphology and Young’s elastic modulus were observed and quantified; giving rise to a novel technique, we have termed “quantitative nanohistology”. An increase in nanoscale stiffness in the collagen for SSc compared with healthy individuals was seen by a significant increase in the Young’s modulus profile for the collagen. These markers of stiffer collagen in SSc are similar to the symptoms experienced by patients, giving additional hope that in the future, nanohistology using AFM can be readily applied as a clinical tool, providing detailed information of the state of collagen

Effects due to a scalar coupling on the particle-antiparticle production in the Duffin-Kemmer-Petiau theory

The Duffin-Kemmer-Petiau formalism with vector and scalar potentials is used to point out a few misconceptions diffused in the literature. It is explicitly shown that the scalar coupling makes the DKP formalism not equivalent to the Klein-Gordon formalism or to the Proca formalism, and that the spin-1 sector of the DKP theory looks formally like the spin-0 sector. With proper boundary conditions, scattering of massive bosons in an arbitrary mixed vector-scalar square step potential is explored in a simple way and effects due to the scalar coupling on the particle-antiparticle production and localization of bosons are analyzed in some detail

A Spatially Resolved `Inside-out' Outburst of IP Pegasi

We present a comprehensive photometric dataset taken over the entire outburst of the eclipsing dwarf nova IP Peg in September/October 1997. Analysis of the lightcurves taken over the long rise to the peak-of-outburst shows conclusively that the outburst started near the centre of the disc and moved outwards. This is the first dataset that spatially resolves such an outburst. The dataset is consistent with the idea that long rise times are indicative of such `inside-out' outbursts. We show how the thickness and the radius of the disc, along with the mass transfer rate change over the whole outburst. In addition, we show evidence of the secondary and the irradiation thereof. We discuss the possibility of spiral shocks in the disc; however we find no conclusive evidence of their existence in this dataset.Comment: 8 pages, 8 figures, to be appear in MNRA

Chickpea wilt: identification and toxicity of 8-O-methyl-fusarubin from Fusarium acutatum

Fusarium acutatum was isolated from wilting chickpea plants in Pakistan. Filtrates from cultures grown on a defined liquid medium caused permanent wilting of chickpea cuttings and killed cells, isolated enzymically from healthy plants, in a bioassay. Toxic activity was retained by a cyano solid phase extraction cartridge and the toxin was isolated by elution from the cartridge in acetonitrile and Si-gel thin layer chromatography of the eluate. Analytical HPLC of the compound on a cyano column with diode array detection gave a single peak with a homogeneous spectrum and λmax at 224 and 281 nm. NMR and mass spectral studies showed that the toxin was 8-O-methyl-fusarubin. The pure compound caused permanent wilting of chickpea cuttings and the LD50 value in the cell bioassay was 327 ng/ml

Relativistic confinement of neutral fermions with a trigonometric tangent potential

The problem of neutral fermions subject to a pseudoscalar potential is investigated. Apart from the solutions for $E=\pm mc^{2}$, the problem is mapped into the Sturm-Liouville equation. The case of a singular trigonometric tangent potential ($\sim \mathrm{tan} \gamma x$) is exactly solved and the complete set of solutions is discussed in some detail. It is revealed that this intrinsically relativistic and true confining potential is able to localize fermions into a region of space arbitrarily small without the menace of particle-antiparticle production.Comment: 12 page

METABOLIC AND HORMONAL RESPONSE TO ACUTE MYOCARDIAL INFARCTION

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22335/1/0000780.pd