No abstract

An inherited syndrome characterized by recurrent or progressive necrotic soft-tissue infections, diminished pus formation, impaired wound healing, granulocytosis, and/or delayed umbilical cord severance was recognized in four male and four female patients. As shown with subunit-specific monoclonal antibodies in immunofluorescence flow cytometry and 125I immunoprecipitation techniques, in addition to a NaB3H4-galactose oxidase labeling assay, granulocytes, monocytes, or lymphocytes from these individuals had a "moderate" or "severe" deficiency of Mac-1, LFA-1, or p150,95 (or a combination)--three structurally related "adhesive" surface glycoproteins. Two distinct phenotypes were defined on the basis of the quantity of antigen expressed. Three patients with severe deficiency and four patients with moderate deficiency expressed less than 0.3% and 2.5%-31% of normal amounts of these molecules on granulocyte surfaces, respectively. The severity of clinical infectious complications among these patients was directly related to the degree of glycoprotein deficiency. More profound abnormalities of tissue leukocyte mobilization, granulocyte-directed migration, hyperadherence, phagocytosis of iC3b-opsonized particles, and complement- or antibody-dependent cytotoxicity were found in individuals with severe, as compared with moderate, deficiency. It is proposed that in vivo abnormalities of leukocyte mobilization reflect the critical roles of Mac-1 glycoproteins in adhesive events required for endothelial margination and tissue exudation. The recognition of phenotypic variation among patients with Mac-1, LFA-1 deficiency may be important with respect to therapeutic strategies.

Fecundity characteristics, phenology, and behavior of insect flower—visitors were studied for 7 early flowering woodland herbs: Claytonia virginica, Dentaria laciniata, Dicentra canadensis, Dicentra cucullaria, Erythronium albidum, Isopyrum biternatum, and Sanguinaria canadensis. Sanguinaria canadensis is facultatively autogamous, the Dicentras are obligate outcrossers, and the remainder are self—compatible, at least within a stem. All are insect pollinated except sometimes S. canadensis. The numbers of ovules per flower and flowers per stem tended to be inversely correlated, and large—seeded species (S. canadensis, E. albidum, I. biternatum) had lower numbers of potential seeds per stem than did small—seeded species. Flowering of all species typically occurred during the first prolonged period of weather suitable for pollinator activity and ceased by the time the canopy closed. Annual differences in flowering times were associated with differences in average temperatures (i.e., early blooming in a warm, early spring), but cumulative degree—hours or degree—days of air or soil temperatures were not well correlated with flowering times. Other constraints on flowering phenology are discussed, including the predictability of suitable conditions, a proposed "fail—safe" mechanism that may assure flowering before canopy closure even if temperatures are abnomally low, and the importance of nontemperature factors in defining suitable conditions. Flowering time was not very finely tuned to the temperature regime and pollinator activity; flowers blooming during the flowering peak often had low seed production and the fertilization rate of most species was low. Evidence that seed production may have been pollinator limited for several species was obtained by comparing the success of hand pollination and of natural pollination, rarity of certain specialized pollinators, and estimates of the abortion rates of fertilized ovules. We suggest that flowering in early spring is a high—risk option in terms of insect—mediated sexual reproduction. Certain flower—visiting insects favored D. laciniata out of proportion to its abundance, but no effect on seed set of other species was detectable. Honeybees were abundant and active flower visitors with the potential for disrupting ecological/evolutionary relationships between native insects and flowers.

The evolution of Ca2−xNaxCuO2Cl2 from Mott insulator to superconductor was studied using angle-resolved photoemission spectroscopy. By measuring both the excitations near the Fermi energy as well as non-bonding states, we tracked the doping dependence of the electronic structure and the chemical potential with unprecedented precision. Our work reveals failures in the conventional quasiparticle theory, including the broad lineshapes of the insulator and the apparently paradoxical shift of the chemical potential within the Mott gap. To resolve this, we develop a model where the quasiparticle is vanishingly small at half filling and grows upon doping, allowing us to unify properties such as the dispersion and Fermi wavevector with the behavior of the chemical potential.PACS numbers: 74.20. Rp, 74.25.Jb, A central intellectual issue in the field of hightemperature superconductivity is how an antiferromagnetic insulator evolves into a superconductor. In principle, the ideal tool to address this problem is angleresolved photoemission spectroscopy (ARPES), which can directly extract the single-particle excitations. Despite the interest in this doping induced crossover, there continues to be a lack of experimental consensus, perhaps the most prominent example being the controversy over the chemical potential, µ. Over the past fifteen years, there have been conflicting claims of µ either being pinned in mid-gap or shifting to the valence / conduction band upon carrier doping [1,2,3,4,5,6]. The inability of photoemission spectroscopy to provide a logically consistent understanding of this fundamental thermodynamic quantity has been a dramatic shortcoming in the field.In this paper, we present a new procedure to quantify µ with unprecedented precision by ARPES, while allowing simultaneous high resolution measurements on the low energy states. These measurements allow us to make major conceptual advances in addressing the doping evolution. We find that the long standing confusion over µ stems from the manner in which quasiparticle-like (QP) excitations in the doped samples emerge from the unusually broad features in the undoped insulator. Our work reveals inconsistencies in the conventional framework that considers the main peak in the insulator spectrum to represent the QP pole. On the one hand, we find that µ changes in a manner consistent with an approximate rigid band shift; on the other hand, this shift appears to occur within the apparent Mott gap of the parent insulator. We show that this ostensible paradox can be naturally explained if one uses a model based on Franck-Condon-like broadening (FCB) where the quasiparticle residue, Z, is vanishingly small near half filling. This also reconciles existing puzzles regarding the insulator and the lightly doped compounds, and naturally ties the behavior of µ to low energy features such as the Fermi wavevector, k F , and the quasiparticle velocity v F .Ca 2−x Na x CuO 2 Cl 2 is an ideal system to address the doping evolution of the cuprates. The stoichiometric parent compoun...