New results for virial coefficients of hard spheres in D dimensions

We present new results for the virial coefficients B_k with k <= 10 for hard spheres in dimensions D=2,...,8.Comment: 10 pages, 5 figures, to appear in conference proceedings of STATPHYS 2004 in Pramana - Journal of Physic

Molecular and immunological characterization of profilin from mugwort pollen

In late summer in Europe, pollen of mugwort is one of the major sources of atopic allergens. No information about the complete molecular structure of any mugwort allergen has been published so far. Here we report the isolation and characterization of mugwort pollen cDNA clones coding for two isoforms of the panallergen profilin. Thirtysix percent of the mugwort allergic patients tested displayed IgE antibodies against natural and recombinant profilin, and no significant differences were observed in the IgEbinding properties of the isoforms. One profilin isoform was purified to homogeneity and detailed structural analysis indicated that the protein exists in solution as dimers and tetramers stabilized by sulfydryl and/or ionic interactions. Profilin monomers were detectable only after exposure of multimers to harsh denaturing conditions. Dimers and tetramers did not significantly differ in their ability to bind serum IgE from mugwort pollenallergic patients. However, oligomeric forms might have a higher allergenic potential than monomers because larger molecules would have additional epitopes for IgEmediated histamine release. Profilin isolated from mugwort pollen also formed multimers. Thus, oligomerization is not an artifact resulting from the recombinant production of the allergen. Inhibition experiments showed extensive IgE crossreactivity of recombinant mugwort profilin and profilin from various pollen and food extracts

Distinct domains of erythroid Kruppel-like factor modulate chromatin remodeling and transactivation at the endogenous beta-globin gene promoter

Characterization of the mechanism(s) of action of trans-acting factors in higher eukaryotes requires the establishment of cellular models that test their function at endogenous target gene regulatory elements. Erythroid Kruppel-like factor (EKLF) is essential for beta -globin gene transcription. To elucidate the in vivo determinants leading to transcription of the adult beta -globin gene, functional domains of EKLF were examined in the context of chromatin remodeling and transcriptional activation at the endogenous locus. Human EKLF (hEKLF) sequences, linked to an estrogen-responsive domain, were studied with an erythroblast cell line lacking endogenous EKLF expression (J2e Delta eklf). J2e Delta eklf cells transduced with hEKLF demonstrated a dose-dependent rescue of beta -globin transcription in the presence of inducing ligand. Further analysis using a series of amino-terminal truncation mutants of hEKLF identified a distinct internal domain, which is sufficient for transactivation. Interestingly, studies of the chromatin structure of the beta -promoter revealed that a smaller carboxy-terminal domain generated an open promoter configuration. In vitro and in vivo binding studies demonstrated that this region interacted with BRG1, a component of the SWI/SNF chromatin remodeling complex. However, further study revealed that BRG1 interacted with an even smaller domain of EKLF, suggesting that additional protein interactions are required for chromatin remodeling at the endogenous beta -promoter. Taken together, our findings support a stepwise process of chromatin remodeling and coactivator recruitment to the beta -globin promoter in vivo. The J2e Delta eklf inducible hEKLF system will be a valuable tool for further characterizing the temporal series of events required for endogenous beta -globin gene transcription

Insensitive HE EOS

A typical insensitive high explosive such as LX-17 has a large carbon-content and produces hydrogen fluoride (HF) as a detonation product. It is also characterized by slow energy release as indicated by a large curvature of the detonation front. We analyze these new physics issues which are needed to predict the performance of a insensitive high explosive. (U

Ninth and Tenth Order Virial Coefficients for Hard Spheres in D Dimensions

We evaluate the virial coefficients B_k for k<=10 for hard spheres in dimensions D=2,...,8. Virial coefficients with k even are found to be negative when D>=5. This provides strong evidence that the leading singularity for the virial series lies away from the positive real axis when D>=5. Further analysis provides evidence that negative virial coefficients will be seen for some k>10 for D=4, and there is a distinct possibility that negative virial coefficients will also eventually occur for D=3.Comment: 33 pages, 12 figure

Aharonov-Bohm effect and resonances in the circular quantum billiard with two leads

We calculate the conductance through a circular quantum billiard with two leads and a point magnetic flux at the center. The boundary element method is used to solve the Schrodinger equation of the scattering problem, and the Landauer formula is used to calculate the conductance from the transmission coefficients. We use two different shapes of leads, straight and conic, and find that the conductance is affected by lead geometry, the relative positions of the leads and the magnetic flux. The Aharonov-Bohm effect can be seen from shifts and splittings of fluctuations. When the flux is equal to (h/2e) and the angle between leads is 180 degree, the conductance tends to be suppressed to zero in the low energy range due to the Aharonov-Bohm effect.Comment: LaTeX2e, 8 pages, 6 figures, submitted to Phys. Rev. B (Two references added. A discussion on discrete symmetries removed.

Food allergy in the Netherlands: differences in clinical severity, causative foods, sensitization and DBPCFC between community and outpatients

Background: It is unknown whether food allergy (FA) in an unselected population is comparable to those from an outpatient clinic population. Objective: To discover if FA in a random sample from the Dutch community is comparable to that of outpatients. Methods: This study was part of the Europrevall-project. A random sample of 6600 adults received a questionnaire. Those with symptoms to one of 24 defined priority foods were tested for sΙgE. Participants with a positive case history and elevated sIgE were evaluated by double-blind placebo-controlled food challenge (DBPCFC). Outpatients with a suspicion of FA were evaluated by questionnaire, sIgE and DBPCFC. Results: In the community, severe symptoms were reported less often than in outpatients (39.3% vs. 54.3%). Participants in the community were less commonly sensitized to any of the foods. When selecting only those with a probable FA (i.e. symptoms of priority food and elevation of sIgE to the respective food), no major differences were observed with respect to severity, causative foods, sensitization and DBPCFC between the groups. Conclusion: In the Netherlands, there are large differences in self-reported FA between community and outpatients. However, Dutch community and outpatients with a probable FA do not differ with respect to severity, causative foods, sensitization and DBPCFC-outcome

Prevalence of food sensitization and probable food allergy among adults in India: the EuroPrevall INCO study

Data are lacking regarding the prevalence of food sensitization and probable food allergy among general population in India. We report the prevalence of sensitization and probable food allergy to 24 common foods among adults from general population in Karnataka, South India. The study was conducted in two stages: a screening study and a case-control study. A total of 11 791 adults in age group 20-54 were randomly sampled from general population in South India and answered a screening questionnaire. A total of 588 subjects (236 cases and 352 controls) participated in the case-control study involving a detailed questionnaire and specific IgE estimation for 24 common foods. A high level of sensitization (26.5%) was observed for most of the foods in the general population, higher than that observed among adults in Europe, except for those foods that cross-react with birch pollen. Most of the sensitization was observed in subjects who had total IgE above the median IgE level. A high level of cross-reactivity was observed among different pollens and foods and among foods. The prevalence of probable food allergy (self-reports of adverse symptoms after the consumption of food and specific IgE to the same food) was 1.2%, which was mainly accounted for cow's milk (0.5%) and apple (0.5%). Very high levels of sensitization were observed for most foods, including those not commonly consumed in the general population. For the levels of sensitization, the prevalence of probable food allergy was low. This disassociation needs to be further explored in future studie