The use of immunocytochemical study in the cytologic diagnosis of melanoma: Evaluation of three antibodies

There are limited studies on the utility of immunostaining in cytologic specimens suspected of melanoma. In this study, we examined the performance of the most commonly used antibodies including monoclonal antibodies against Melan‐A (A103), S‐100, and HMB‐45 antigens. Immunostains were performed on formalin‐fixed, paraffin‐embedded cell blocks prepared from 100 cytologic specimens. The specimens consisted of 57 melanomas and 43 nonmelanocytic neoplasms. Of 57 melanomas, 53 showed positive reaction to Melan‐A antibody while 51 and 41 revealed positive immunostaining for S‐100 and HMB‐45, respectively. Of 43 nonmelanocytic neoplasms, 10, 4, and 8 specimens stained positive with an antibody against S‐100, HMB‐45, and Melan‐A, respectively. However, the false‐positive immunostaining for Melan‐A was eliminated in seven of the eight specimens after applying the pretreatment with avidin/biotin blocking reagents. Overall, the highest sensitivity and negative predictive value (NPV) were achieved in Melan‐A antibody (93 and 90%) compared with antibodies to S‐100 (89 and 85%), and HMB‐45 (72 and 71%). Initially, an intermediate specificity and positive predictive value (PPV) were obtained for Melan‐A antibody (81 and 87%) that were greater than S‐100 (77 and 84%), and lower than HMB‐45 (91 and 91%). However, the aforementioned treatment with avidin/biotin blocking reagents improved both specificity (98%) and PPV (98%) for Melan‐A antibody. In conclusion, by blocking endogenous biotin, Melan‐A antibody offers the greatest performance. In terms of cost‐effectiveness, we suggested that Melan‐A antibody should be used as the first‐line antibody for detecting melanoma in the cytologic specimens. Diagn. Cytopathol. 2013. © 2011 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96298/1/21791_ftp.pd

Spectral Density on the Lattice

Spectral density in the pseudoscalar and vector channels is extracted from the SU(2) lattice quenched data. It is shown to consist of three sharp poles within the energy range accessible on the lattice.Comment: 38 pages, uuencoded tar-compressed ps-fil

Scalar Top Quark as the Next-to-Lightest Supersymmetric Particle

We study phenomenologically the scenario in which the scalar top quark is lighter than any other standard supersymmetric partner and also lighter than the top quark, so that it decays to the gravitino via stop -> W^+ b G. In this case, scalar top quark events would seem to be very difficult to separate from top quark pair production. However, we show that, even at a hadron collider, it is possible to distinguish these two reactions. We show also that the longitudinal polarization of the final $W^+$ gives insight into the scalar top and wino/Higgsino mixing parameters.Comment: 18 pages, LaTeX, 7 figures, minor typographical correction

Group Member Prototypicality and Intergroup Negotiation: How One's Standing in the Group Affects Negotiation Behaviour

How does a representative's position in the group influence behaviour in intergroup negotiation? Applying insights from the social identity approach (specifically self-categorization theory), the effects of group member prototypicality, accountability, and group attractiveness on competitiveness in intergroup bargaining were examined. As representatives of their group, participants engaged in a computer-mediated negotiation with a simulated outgroup opponent. In Exp. 1 (N = 114), representatives with a peripheral status in the group sent more competitive and fewer cooperative messages to the opponent than did prototypical representatives, but only under accountability. Exp. 2 (N = 110) replicated this finding, and showed that, under accountability, peripherals also made higher demands than did prototypicals, but only when group membership was perceived as attractive. Results are discussed in relation to impression management and strategic behaviour

Networks and coalitions in the implementation of the International Treaty on Plant Genetic Resources for Food and Agriculture in Uganda

Uganda acceded to the International Treaty for Plant Genetic Resources for Food and Agriculture (ITPGTFA) in the year 2003. Despite this, there are still gaps in implementation of the treaty in the country. The article provides insights into the systemic interactions and coalitions among actors in the implementation of the treaty and subsequent barriers to the implementation of the ITPGRFA. Using social network analysis, the interactions of 26 key policy actors are mapped for 4 main expertise networks that are important for implementation of the treaty; that is, the policy direction networks; scientific expertise; financial expertise; and legal networks in order to identify gaps for further action. Findings indicate that the linkages between actors are poor especially in the legal expertise and policy direction networks where the competent authority for the treaty does not have efficient connections with critical and non-critical actors. Many key actors are also excluded from the network leading poor information and resource flows among stakeholders implementing the treaty. In the interim, a memorandum of understanding has been signed by three major institutions that are key to establish clear processes for implementation of the treaty and establishing clear guidelines for access and benefit sharing and clear roles of institutions involved in the policy development and implementation. Key lessons learned from this research are that networks and coalitions are important for fostering information and exchange of expertise to enable effective implementation or domestication of the international treaty (IT). The structured engagement of other non-governmental stakeholders such as non-governmental organisations (NGOs) and international organizations that provide financial and technical support for various aspects of policy implementation is also important

The Grover algorithm with large nuclear spins in semiconductors

We show a possible way to implement the Grover algorithm in large nuclear spins 1/2<I<9/2 in semiconductors. The Grover sequence is performed by means of multiphoton transitions that distribute the spin amplitude between the nuclear spin states. They are distinguishable due to the quadrupolar splitting, which makes the nuclear spin levels non-equidistant. We introduce a generalized rotating frame for an effective Hamiltonian that governs the non-perturbative time evolution of the nuclear spin states for arbitrary spin lengths I. The larger the quadrupolar splitting, the better the agreement between our approximative method using the generalized rotating frame and exact numerical calculations.Comment: 11 pages, 18 EPS figures, REVTe

Oxytocin Motivates Non-Cooperation in Intergroup Conflict to Protect Vulnerable In-Group Members

Intergroup conflict is often driven by an individual's motivation to protect oneself and fellow group members against the threat of out-group aggression, including the tendency to pre-empt out-group threat through a competitive approach. Here we link such defense-motivated competition to oxytocin, a hypothalamic neuropeptide involved in reproduction and social bonding. An intergroup conflict game was developed to disentangle whether oxytocin motivates competitive approach to protect (i) immediate self-interest, (ii) vulnerable in-group members, or (iii) both. Males self-administered oxytocin or placebo (double-blind placebo-controlled) and made decisions with financial consequences to themselves, their fellow in-group members, and a competing out-group. Game payoffs were manipulated between-subjects so that non-cooperation by the out-group had high vs. low impact on personal payoff (personal vulnerability), and high vs. low impact on payoff to fellow in-group members (in-group vulnerability). When personal vulnerability was high, non-cooperation was unaffected by treatment and in-group vulnerability. When personal vulnerability was low, however, in-group vulnerability motivated non-cooperation but only when males received oxytocin. Oxytocin fuels a defense-motivated competitive approach to protect vulnerable group members, even when personal fate is not at stake

Tidal torques. A critical review of some techniques

We point out that the MacDonald formula for body-tide torques is valid only in the zeroth order of e/Q, while its time-average is valid in the first order. So the formula cannot be used for analysis in higher orders of e/Q. This necessitates corrections in the theory of tidal despinning and libration damping. We prove that when the inclination is low and phase lags are linear in frequency, the Kaula series is equivalent to a corrected version of the MacDonald method. The correction to MacDonald's approach would be to set the phase lag of the integral bulge proportional to the instantaneous frequency. The equivalence of descriptions gets violated by a nonlinear frequency-dependence of the lag. We explain that both the MacDonald- and Darwin-torque-based derivations of the popular formula for the tidal despinning rate are limited to low inclinations and to the phase lags being linear in frequency. The Darwin-torque-based derivation, though, is general enough to accommodate both a finite inclination and the actual rheology. Although rheologies with Q scaling as the frequency to a positive power make the torque diverge at a zero frequency, this reveals not the impossible nature of the rheology, but a flaw in mathematics, i.e., a common misassumption that damping merely provides lags to the terms of the Fourier series for the tidal potential. A hydrodynamical treatment (Darwin 1879) had demonstrated that the magnitudes of the terms, too, get changed. Reinstating of this detail tames the infinities and rehabilitates the "impossible" scaling law (which happens to be the actual law the terrestrial planets obey at low frequencies).Comment: arXiv admin note: sections 4 and 9 of this paper contain substantial text overlap with arXiv:0712.105

Selectron Studies at e-e- and e+e- Colliders

Selectrons may be studied in both e-e- and e+e- collisions at future linear colliders. Relative to e+e-, the e-e- mode benefits from negligible backgrounds and \beta threshold behavior for identical selectron pair production, but suffers from luminosity degradation and increased initial state radiation and beamstrahlung. We include all of these effects and compare the potential for selectron mass measurements in the two modes. The virtues of the e-e- collider far outweigh its disadvantages. In particular, the selectron mass may be measured to 100 MeV with a total integrated luminosity of 1 fb^-1, while more than 100 fb^-1 is required in e+e- collisions for similar precision.Comment: 16 pages, 11 figure

No Far-Infrared-Spectroscopic Gap in Clean and Dirty High-TC_C Superconductors

We report far infrared transmission measurements on single crystal samples derived from Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$. The impurity scattering rate of the samples was varied by electron-beam irradiation, 50MeV $^{16}$O$^{+6}$ ion irradiation, heat treatment in vacuum, and Y doping. Although substantial changes in the infrared spectra were produced, in no case was a feature observed that could be associated with the superconducting energy gap. These results all but rule out ``clean limit'' explanations for the absence of the spectroscopic gap in this material, and provide evidence that the superconductivity in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ is gapless.Comment: 4 pages and 3 postscript figures attached. REVTEX v3.0. Accepted for publication in Phys. Rev. Lett. IRDIRT