Supergravity on R4 x S1/Z2 and singular Calabi-Yaus

We discuss the moduli space singularities that are generally present in five-dimensional vector-coupled supergravity on a spactime of the form R4 x S1/Z2, with vector fields surviving on the Z2 fixed planes. The framework of supergravity is necessarily ambiguous when it comes to the non-singular embedding theory, so we focus on those models coming from Calabi-Yau three-folds with wrapped membranes.Comment: 13 p

Unified N=2 Maxwell-Einstein and Yang-Mills-Einstein Supergravity Theories in Four Dimensions

We study unified N=2 Maxwell-Einstein supergravity theories (MESGTs) and unified Yang-Mills Einstein supergravity theories (YMESGTs) in four dimensions. As their defining property, these theories admit the action of a global or local symmetry group that is (i) simple, and (ii) acts irreducibly on all the vector fields of the theory, including the ``graviphoton''. Restricting ourselves to the theories that originate from five dimensions via dimensional reduction, we find that the generic Jordan family of MESGTs with the scalar manifolds [SU(1,1)/U(1)] X [SO(2,n)/SO(2)X SO(n)] are all unified in four dimensions with the unifying global symmetry group SO(2,n). Of these theories only one can be gauged so as to obtain a unified YMESGT with the gauge group SO(2,1). Three of the four magical supergravity theories defined by simple Euclidean Jordan algebras of degree 3 are unified MESGTs in four dimensions. Two of these can furthermore be gauged so as to obtain 4D unified YMESGTs with gauge groups SO(3,2) and SO(6,2), respectively. The generic non-Jordan family and the theories whose scalar manifolds are homogeneous but not symmetric do not lead to unified MESGTs in four dimensions. The three infinite families of unified five-dimensional MESGTs defined by simple Lorentzian Jordan algebras, whose scalar manifolds are non-homogeneous, do not lead directly to unified MESGTs in four dimensions under dimensional reduction. However, since their manifolds are non-homogeneous we are not able to completely rule out the existence of symplectic sections in which these theories become unified in four dimensions.Comment: 47 pages; latex fil

Detection Of Brugia Malayi And Brugia Pahangi Parasites By Biotinlabeled Dna Probes

Morphologically, the larvae of Brugian parasites are difficult to differentiate by conventional methods. Recently, radioactive labeled DNA probes2'3 have been developed to distinguish the larvae of these parasites. However, these probes have a short shelf-life and are hazardous to the users. Two oligonucleotide DNA probes have been tested, one is specific for B.malayi and the other specific for B.pahangi. They were each labeled with Biotin in three different ways by using : a one-tailed 30mer biotinylated uridine residues, a two-tailed 30mer biotinylated uridine-thymidine residues. The dot blot assays were tested at various temperatures (30°C-80°C) using different concentrations of parasite DNAs (12.8ng-0.1ng). Our preliminary results indicated that the sensitivity and specificity of the biotinylated DNA probes, with a two-tailed 45mer biotinylated residues, were highly acceptable for field use

Counting and effective rigidity in algebra and geometry

The purpose of this article is to produce effective versions of some rigidity results in algebra and geometry. On the geometric side, we focus on the spectrum of primitive geodesic lengths (resp., complex lengths) for arithmetic hyperbolic 2-manifolds (resp., 3-manifolds). By work of Reid, this spectrum determines the commensurability class of the 2-manifold (resp., 3-manifold). We establish effective versions of these rigidity results by ensuring that, for two incommensurable arithmetic manifolds of bounded volume, the length sets (resp., the complex length sets) must disagree for a length that can be explicitly bounded as a function of volume. We also prove an effective version of a similar rigidity result established by the second author with Reid on a surface analog of the length spectrum for hyperbolic 3-manifolds. These effective results have corresponding algebraic analogs involving maximal subfields and quaternion subalgebras of quaternion algebras. To prove these effective rigidity results, we establish results on the asymptotic behavior of certain algebraic and geometric counting functions which are of independent interest.Comment: v.2, 39 pages. To appear in Invent. Mat

A Field Study Using the Polymerase Chain Reaction (Pcr) to Screen for Brugia Microfilariae in Human and Animal Blood

Blood samples from 43 humans and 14 cats positive with Brugia microfilariae were analyzed in a field study in Tanjung Pinang, Indonesia. The study used the polymerase chain reaction (PCR) to compare the sensitivity of radioactive and biotinylated species-specific oligonuleotide probes. The cloning char­acterization of the Hha I repeat DNA family found in filarial parasites of the genus Brugia, and the development of species-specific probes for B.malayi and B.pahangi based on these repeats has been described elsewhere (PNAS USA 83: 797-801); Mol.Biochem. Parasitol. 2$: 163-170). The use of radioisotopes for labelling DNA probes is both expensive and inconvenient. To replace these probes, biotinylated DNA probes have been designed for non- radioactive detection of B.malayi and B.pahangi. These oligonucleotide probes have long tails of biotinylated uridine residues added to their 5\u27 end. As little as 100 pg of Brugia DNA can be detected on dot blot with these probes. Detection of the probes is based on an avidin-alkaline phosphatase colorimetric assay. In order to distinguish between infected from uninfected individuals, it is necessary to detect the amount of DNA in one microfilaria (about 60 pg). The polymerase chain reaction (PCR) is a procedure in which a small amount of DNA can be amplified up to 1 million-fold. A part of each sample in this study was PCR amplified and compared with the unamplified portion using both the radioactive and biotinylated DNA probe. The PCR amplified samples were accurately identified by both the radioactive and biotinylated B.malayi and B.pahangi probes. Even samples with as few as two microfilariae per lOOul of blood were easily detected. The samples that were not PCR amplified were accurately identified after only long exposures (greater than one week) to the radioactive probes. The biotinylated probes, were not sensitive enough for accurate identification of the non-PCR amplified samples. The polymerase chain reaction is, therefore, a promising new tool for enhancing the sensitivity of parasite detection assays based on DNA probes. This will be especially important in designing assay based on non-radioactive DNA probes

Corticosterone Potentiation of Cocaine-Induced Reinstatement of Conditioned Place Preference in Mice is Mediated by Blockade of the Organic Cation Transporter 3

The mechanisms by which stressful life events increase the risk of relapse in recovering cocaine addicts are not well understood. We previously reported that stress, via elevated corticosterone, potentiates cocaine-primed reinstatement of cocaine seeking following self-administration in rats and that this potentiation appears to involve corticosterone-induced blockade of dopamine clearance via the organic cation transporter 3 (OCT3). In the present study, we use a conditioned place preference/reinstatement paradigm in mice to directly test the hypothesis that corticosterone potentiates cocaine-primed reinstatement by blockade of OCT3. Consistent with our findings following self-administration in rats, pretreatment of male C57/BL6 mice with corticosterone (using a dose that reproduced stress-level plasma concentrations) potentiated cocaine-primed reinstatement of extinguished cocaine-induced conditioned place preference. Corticosterone failed to re-establish extinguished preference alone but produced a leftward shift in the dose–response curve for cocaine-primed reinstatement. A similar potentiating effect was observed upon pretreatment of mice with the non-glucocorticoid OCT3 blocker, normetanephrine. To determine the role of OCT3 blockade in these effects, we examined the abilities of corticosterone and normetanephrine to potentiate cocaine-primed reinstatement in OCT3-deficient and wild-type mice. Conditioned place preference, extinction and reinstatement of extinguished preference in response to low-dose cocaine administration did not differ between genotypes. However, corticosterone and normetanephrine failed to potentiate cocaine-primed reinstatement in OCT3-deficient mice. Together, these data provide the first direct evidence that the interaction of corticosterone with OCT3 mediates corticosterone effects on drug-seeking behavior and establish OCT3 function as an important determinant of susceptibility to cocaine use

Isolation of Salmonella spp. and bacteriophage active against Salmonella spp. from commercial swine

Bacteriophage are viruses that prey on bacteria and may be a potential strategy to reduce foodborne pathogemc bactena in the gastromtestlnal tract of food animals Phages are fairly common in the gastrointestinal microbial ecosystem of mammals, but the incidence is unknown. If phage are to be an intervention strategy, we must understand their role in the microbial ecology of the gut. From a regulatory perspective, knowing incidence of phage is crucial. Therefore the current study was designed to determine the incidence of phage active against Salmonella spp in the feces of commercial finishing swine in the United States. Fecal samples (n=60) were collected from each of six commercial swine finishing operations. Samples were collected from 10 randomly selected pens throughout each operation. Total number of fecal samples collected in this study was n=360 Salmonella spp were found in 66% of the fecal samples Salmonella spp. were isolated from only 2 farms and the serotypes represented were Schwarzengrund, Anatum, Ohio and Heidelberg Bacteriophages were isolated from fecal sample through 2 parallel methods, 1) initlal enrichment in Salmonella Typhimunum, or 2) initial ennchment in E. colt B (a strain very sensitive to phages), followed by direct spot-testing against Salmonella Typhimurium Bacteriophages active against Salmonella Typhimunum were isolated from 1.1% 4/360) of the individual fecal samples when initially enriched in Salmonella Typhimurium, but E coli S-killing phages were 1solated from 43.8% (158/360) of the fecal samples but only 2 of these Isolates were capable of k1ll1ng Salmonella Typhimunum. Our results mdicate that bactenophage capable of killing Salmonella Typh1murium are fairly w1despread across commercial swine production facilities but may be present at relatively low populat1ons These results md1cate that phage (predator) populations may vary along w1th Salmonella (prey) populations and that phage could potentially be used as a food safety pathogen reduction strategy

Reduction of Campylobacter and Salmonella in pigs treated with A select nitrocompound

The aim of this study was to test the effectiveness of administering a select nitrocompound (S-NO) on reducing naturally colonized Campylobacter and experimentally infected Salmonella in the weaned pig gut. Pigs were divided into four groups; control (0 g S-NO/pig), 1X (0.2 g S-NO/pig), 5X (1 g S-NO/pig), and 10X (2 g S-NO/pig). Treatments were administered via oral gavage 24 h before sacrifice. Mean ± SD populations (log10 cfu/g) of Campylobacter in the cecum were reduced (P \u3c 0.05) in pigs receiving the 10X dose when compared with untreated controls (1.64 ± 1.30 vs 5.31 ± 0.58, respectively). Campylobacter concentrations in rectal contents from pigs administered the 5X dose were reduced (P \u3c 0.05) compared to control (2.65 ± 2.86 vs 5.90 ± 0.94, respectively). Rectal Salmonella concentrations were reduced (P \u3c 0.05) in all of the S-NO-treated groups. Adverse effects of S-NO on pig health were not observed. These results demonstrate that S-NO may have potential as an intervention to reduce pig colonization by Campylobacter and Salmonella

The R-map and the Coupling of N=2 Tensor Multiplets in 5 and 4 Dimensions

We study the dimensional reduction of five dimensional N=2 Yang-Mills-Einstein supergravity theories (YMESGT) coupled to tensor multiplets. The resulting 4D theories involve first order interactions among tensor and vector fields with mass terms. If the 5D gauge group, K, does not mix the 5D tensor and vector fields, the 4D tensor fields can be integrated out in favor of 4D vector fields and the resulting theory is dual to a standard 4D YMESGT. The gauge group has a block diagonal symplectic embedding and is a semi-direct product of the 5D gauge group K with a Heisenberg group of dimension (2P+1), where 2P is the number of tensor fields in five dimensions. There exists an infinite family of theories, thus obtained, whose gauge groups are pp-wave contractions of the simple noncompact groups of type SO*(2M). If, on the other hand, the 5D gauge group does mix the 5D tensor and vector fields, the resulting 4D theory is dual to a 4D YMESGT whose gauge group does, in general,NOT have a block diagonal symplectic embedding and involves additional topological terms. The scalar potentials of the dimensionally reduced theories naturally have some of the ingredients that were found necessary for stable de Sitter ground states. We comment on the relation between the known 5D and 4D, N=2 supergravities with stable de Sitter ground states.Comment: 42 pages;latex fil