Will at least one of the Higgs bosons of the next-to-minimal supersymmetric extension of the Standard Model be observable at LEP2 or the LHC?

We demonstrate that there are regions of parameter space in the next-to-minimal (i.e. two-Higgs-doublet, one-Higgs-singlet superfield) supersymmetric extension of the SM for which none of the Higgs bosons are observable either at LEP2 with $\sqrt{s}=192 GeV$ and an integrated luminosity of $L=1000 inverse pb$ or at the LHC with $L=600 inverse fb$.Comment: 6 pages, full postscript file also available via anonymous ftp at ftp://ucdhep.ucdavis.edu/gunion/nmssm_sm96.ps To appear in ``Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics'

Top-quark decay via R-parity violating interactions at the Tevatron

We consider the top-quark decay $t\to \tilde \tau b$ and $t\to \tau b \tilde{\chi}^0_1$ via explicit R-parity violating interactions in SUSY theories. We discuss the observability of those channels at the Fermilab Tevatron collider. The existing Tevatron data indicate a 95% confidence level upper bound on the coupling to be less than 0.94(0.63) for a long-lived (short-lived) $\tilde{\chi}^0_1$ with $m_{\tilde\tau}=70$ GeV. At Tevatron Run II with an integrated luminosity of 2 (10) fb$^{-1}$, one can obtain a 2$\sigma$ constraint as 0.38 (0.24) for a long-lived $\tilde{\chi}^0_1$ and 0.29(0.19) for a short-lived $\tilde{\chi}^0_1$, beyond the current indirect limit.Comment: 16 pages, 7 eps figures. Using LaTeX with axodraw. LSP decay mode included; more refs.; to appear in PL

Morphology, ultrastructure, and function of extrafloral nectaries in three species of Caesalpiniacae

Journal ArticleLight and electron microscopy reveal that the morphologically well-differentiated petiolar nectaries of Ckamaecrista fasciculata, Senna hepecarpa, and S. marilandica have an unusually simple anatomy consisting of an epidermis immediately subtended by a mass of small, loosely-packed parenchyma cells. Vascular strands from the petiolar bundles enter the nectary and terminate as phloem within or near this parenchyma. In mature, secreting nectaries, the cuticle of the epidermis extends between the epidermal cells and into the nectary parenchyma, where it occupies, but does not occlude, much of the free space of this tissue. The cutin is not found below the level of the phloem endings and it is not found in very young nectaries, but begins to appear when cell expansion occurs. These observations, together with the proximity of phloem to the parenchyma free space and the almost exclusive presence of sucrose in the nectar suggest that, although symplastic transport of sugars may occur, an alternate pathway for secretion is possible whereby sugar diffuses from the phloem, moves through the nectary to the surface without being acted upon by cells in transit, and is released by rupture of the external cuticle and the concomitant activity of foraging ants and other nectar feeders

Chargino Production and Decay in Photon-Photon-Collisions

We study the production and leptonic decay of charginos in collisions of polarized photon beams including the complete spin correlations. The photons can be generated by Compton backscattering of polarized laser pulses off a polarized electron beam. Since the production process is determined alone by the electromagnetic coupling of the charginos this process allows to study their decay dynamics. The cross section and the forward-backward asymmetry of the decay lepton are very sensitive to the gaugino mass parameter $M_1$ and to the sneutrino mass without any ambiguities.Comment: 9 pages, 6 figures, LaTeX, Talk presented at the International Workshop on High Energy Photon Collider

Sweet corn seed studies

Sweet corn is the most important canning crop grown in Iowa. The average annual pack in this state for the past five years is approximately 2,500,000 cases. High grade seed, both as to canning quality and vitality, is of primary importance to the canning industry. Due perhaps to its sugary character, sweet corn is more difficult to cure than field corn. Also, it is a plant of less vigor and more subject to diseases. Greater care is therefore required in curing and handling the seed. This study was undertaken to secure information regarding: 1. Methods of hastening the curing of sweet corn seed in the field by topping the plants, by opening the husks and by curing in the shock. 2. The kiln drying of sweet corn seed. 3. The influence of immature seed. 4. Relation of vigor of germination to yield

Financial Factors, Firm size and Firm potential

Using a unique dataset covering the universe of Portuguese firms and their credit situation we show that financially constrained firms are found across the entire firm size distribution, account for a larger total asset share compared to standard heterogeneous firms models, and exhibit a higher cyclical sensitivity, conditional on size. In light of these findings we reassess the importance of the firm distribution in shaping aggregate outcomes in the canonical model of heterogeneous firms with financial frictions. We augment the productivity process with ex-ante heterogeneity of firms, allowing us to match the distribution of constrained firms conditional on size. This, together with the fact that constrained firms have a higher capital elasticity, leads to up to four times larger aggregate fluctuations and capital misallocation

Notes on some of the newer vegetables

In presenting the following report on some of the newer vegetables recently tested at the Iowa Agricultural Experiment Station, no attempt is made to embrace all the new varieties or possible synonyms offered in the American seed trade. In cases where the results were so distinctly negative as to indicate that the variety was unsuited to the soil and climatic condition of central Iowa, it was omitted from the list. The fact that a variety may be of special value for one purpose, but possibly inferior for another, should be borne in mind. The Ohio Canner beet is admirably adapted for the canners’ needs, but not particularly suited for the market gardener. The same may be said of other crops, such as sweet corn and tomatoes