cssi/SciSciGPT-SciSciNet huggingface dataset:
Derepression of Uridine Diphosphate-Glucose Pyrophosphorylase (galU) in capR(lon), capS, and capT Mutants and Studies on the galU Repressor

Mutation of the capR(lon), capS, or capT genes in Escherichia coli K-12 causes overproduction of capsular polysaccharide leading to a mucoid phenotype. Several of the enzymes involved in capsular polysaccharide synthesis are derepressed in cap mutants. Previously it was shown that uridine diphosphate-glucose (UDPG) pyrophosphorylase, an enzyme involved in the synthesis of three of the nucleotide sugar precursors of the capsule, is derepressed in capR mutants. The control of galU, the gene which codes for UDPG pyrophosphorylase, is described in this study. In addition, it has been found that the enzyme is also derepressed in capS and capT mutants. The effect of galU gene dosage in cap mutants and the wild-type strain (all lysogenic for phi80) was studied by infecting them with the purified transducing phage phi80dgalU. The level of UDPG pyrophosphorylase increased in proportion to the number of galU copies added. The rate of enzyme synthesis in the mutants was about sixfold higher than in the wild type per galU gene added for multiplicities of infection from one to twenty. Thus, all the galU copies added to the wild-type lysogen were repressed. We obtain greater than 20 galU copies per cell by infecting the nonlysogenic strain which allows multiplication of phi80dgalU. With some number of galU copies greater than 20, the rate of UDPG pyrophosphorylase synthesis in the wild type approaches the mutant rate of synthesis. The results suggest that there may indeed be a galU repressor pool in the cell which can be completely titrated. This pool must be composed of more than 20 galU repressor molecules. Since the capR, capS, and capT gene products or combinations thereof are known to control other widely separated operons of the cell besides the galU gene, it is postulated that the galU repressor may be capable of binding other operators. This would account for the relatively large pool of galU repressors per cell.
Irreversible Electroporation in Patients with Hepatocellular Carcinoma: Immediate versus Delayed Findings at MR Imaging

Our study demonstrated the presence of large ablation zones with peripheral enhancement at immediate MR imaging after irreversible electroporation in humans.
Extremal weight enumerators and ultraspherical polynomials

We establish an upper bound for the minimum distance of a divisible code in terms of its dual distance. The bound generalizes the Mallows-Sloane bounds for self-dual codes. We obtain a linear recurrence for the distance distribution components of codes that attain the bound. From this we derive known conditions for the existence of extremal self-dual codes in a much simpler way. In the second half of the paper, we determine zeta functions for the codes that attain our new bound. Zeta functions for linear codes are defined in Duursma (Trans. Amer. Math. Soc. 351(9) (1999) 3609). Using properties of ultraspherical polynomials, we show that the zeta function of a quaternary extremal self-dual code has its zeros on the circle |T|=q^-^1^/^2 in analogy with the zeta function of an algebraic curve.
Numerical methods in Markov chain modeling

This paper describes and compares several methods for computing stationary probability distributions of Markov chains. The main linear algebra problem consists of computing an eigenvector of a spar...
Osmo-regulation of bacterial transcription via poised RNA polymerase.

Abstract Adaptation to high-salt environments is critical for the survival of a wide range of cells, especially for pathogenic bacteria that colonize the animal gut and urinary tract. The adaptation strategy involves production of the salt potassium glutamate, which induces a specific gene expression program that produces electro-neutral osmolytes while inhibiting general σ 70 transcription. These data show that in Escherichia coli potassium glutamate stimulates transcription by disengaging inhibitory polymerase interactions at a σ 38 promoter. These occur in an upstream region that is marked by an osmotic shock promoter DNA consensus sequence. The disruption activates a poised RNA polymerase to transcribe. This transcription program leads to the production of osmolytes that are shown to have only minor effects on transcription and therefore help to restore normal cell function. An osmotic shock gene expression cycle is discussed.
Responses to the Michelangelo Computer Virus Threat: The Role of Information Sources and Risk Homeostasis Theory1

Computer users were surveyed before and after the Michelangelo trigger date (March 6, 1992) to examine risk perceptions and performance of risky and protective behaviors. Consistent with Risk Homeostasis theory, population risk perceptions changed over the course of the risk period, while personal risk perceptions remained unchanged. Protective behaviors also changed over the virus threat period and were dependent on the passage of the virus trigger date, prior virus experience, and experience during the period of the risk event. This study: (a) provides a scaling of risky and protective behaviors that others may use in future research, (b) suggests a more vivid picture of risk related behavior can be obtained by evaluating personal versus population risk perceptions and risky versus protective behaviors separately, and (c) suggests that training to reduce risks will be most effective if focused on behaviors that are least central to work activities.
In vitro interaction of fluconazole and amphotericin B administered sequentially against Candida albicans: effect of concentration and exposure time

Abstract This study investigated the potential antagonism of fluconazole on amphotericin B activity against Candida albicans when administered sequentially in vitro. Yeast cells were exposed to fluconazole for time periods ranging from 0 to 24 h before the addition of amphotericin B. The combination showed fungicidal (≥3 log 10 reduction in CFU/mL) activity. After 4 h of exposure to fluconazole, amphotericin B activity was partially inhibited at the lower concentration tested (0.25 × MIC). Amphotericin B activity was dramatically decreased by previous exposure to fluconazole for greater than or equal to 8 h at both the high and low concentrations tested. The activity of amphotericin B against yeast exposed to fluconazole for at least 8 h was indistinguishable from fluconazole alone and was fungistatic (≤2 log 10 reduction in CFU/mL). This inhibition of amphotericin B activity persisted for a very short period (
An unusual BRCA mutation distribution in a high risk cancer genetics clinic

The Database of Individuals at High Risk for Breast, Ovarian, or Other Hereditary Cancers at the Arizona Cancer Center in Tucson, Arizona assesses cancer risk factors and outcomes in patients with a family history of cancer or a known genetic mutation. We analyzed the subset of clinic probands who carry deleterious BRCA gene mutations to identify factors that could explain why mutations in BRCA2 outnumber those in BRCA1. Medical, family, social, ethnic and genetic mutation histories were collected from consenting patients' electronic medical records. Differences between BRCA1 and BRCA2 probands from this database were analyzed for statistical significance and compared to published analyses. A significantly higher proportion of our clinic probands carry mutations in BRCA2 than BRCA1, compared with previous reports of mutation prevalence. This also holds true for the Hispanic sub-group. Probands with BRCA2 mutations were significantly more likely than their BRCA1 counterparts to present to the high risk clinic without a diagnosis of cancer. Other differences between the groups were not significant. Six previously unreported BRCA2 mutations appear in our clinic population. The increased proportion of probands carrying deleterious BRCA2 mutations is likely multifactorial, but may reflect aspects of Southern Arizona's unique ethnic heritage.
SQUID neuromagnetometric reconstruction of brain activity

Ionic flow associated with neural activation of the brain produces a magnetic field that can be measured outside the head in a magnetically unshielded room using a highly sensitive neuromagnetometer based on a superconducting quantum interference device (SQUID). Reconstruction of images portraying the tomographic distribution of neural generators (assumed to be current dipoles) of the neuromagnetic field, a modality that we have termed "neuromagnetic imaging" or NMI, represents a powerful noninvasive method of dynamic functional imaging dependent upon brain structure and activity. Reconstruction in NMI, i.e., the inverse problem, however, has no unique solution and requires incorporation of modeling constraints for practical implementation. Results of several phantom and test-object studies and a preliminary human study to develop the method of NM! under various modeling constraints are presented.
Magnetic Dipole Moments of First 2 + States in Even Osmium Nuclei Recoil-Implanted in Nickel

The ion-implantation-perturbed-angular-correlation technique has been used to measure the $g$ factors of the first ${2}^{+}$ excited states of four even osmium nuclei in a ferromagnetic nickel host. The observed angular precessions were: $\ensuremath{\omega}\ensuremath{\tau}(^{192}\mathrm{Os})=0.22\ifmmode\pm\else\textpm\fi{}0.01$, $\ensuremath{\omega}\ensuremath{\tau}(^{190}\mathrm{Os})=0.277\ifmmode\pm\else\textpm\fi{}0.009$, $\ensuremath{\omega}\ensuremath{\tau}(^{188}\mathrm{Os})=0.39\ifmmode\pm\else\textpm\fi{}0.03$, and $\ensuremath{\omega}\ensuremath{\tau}(^{186}\mathrm{Os})=0.38\ifmmode\pm\else\textpm\fi{}0.08$. The angular precession result for $^{192}\mathrm{Os}$ is in excellent agreement with the results of perturbed-angular-correlation measurements in nickel using radioactive sources. It was found that the internal field seen by the osmium nuclei implanted in nickel is in good agreement with the value obtained by room temperature NMR techniques. The available direct lifetime measurements for $^{186,188}\mathrm{Os}$ and lifetimes extracted from $B(E2)$ values for $^{190,192}\mathrm{Os}$ are used to obtain the gyromagnetic ratios: $g(^{192}\mathrm{Os})=0.39\ifmmode\pm\else\textpm\fi{}0.03$, $g(^{190}\mathrm{Os})=0.39\ifmmode\pm\else\textpm\fi{}0.03$, $g(^{188}\mathrm{Os})=0.29\ifmmode\pm\else\textpm\fi{}0.03$, and $g(^{186}\mathrm{Os})=0.24\ifmmode\pm\else\textpm\fi{}0.05$.
E-Mail Reference as Substitute for Library Receptionist

SUMMARY The authors explore the historical development of e-mail reference services in general, and report on the evolution of this service in their own library. Based on evidence from their own service and from reports in the literature, they propose a connection between e-mail reference service and broader library services including circulation, interlibrary loan, and even acquisitions, through which the reference librarian receives questions traditionally directed elsewhere. The e-ref button presents an unexpected avenue of librarian-to-librarian communication, both within and beyond one's home institution. Implications are discussed.
Spectroscopic material determination via LIBS and CRDS

Laser Induced Spectroscopy (LIBS) and Cavity Ring Down Spectroscopy (CRDS) are promising chemical sensor technologies for small mobile robotic platforms. LIBS leverages the natural surface adsorption from the atmosphere to interior and exterior surfaces for signal enhancement. In this work, a material or class-specific adsorption surface is combined with a miniature version of a CRDS ring cavity to achieve a similar signal enhancement for CRDS. The combination of LIBS and CRDS allow the analysis of both classes of materials - those with long adsorption times to permanent surfaces such as walls and those that require real time sampling of ambient concentrations. This paper emphasizes issues related to package miniaturization, power budget limitations and ruggedness as well as basic performance modeling of the instruments. Comprehensive sensing issues for material specific micro-detectors will be addressed. Computer simulations and some data are presented. Applications considered include the determination of need for remediation and the determination of the effectiveness of remediation techniques as well as the detection of hazards and intelligence gathering.
The effects of chemical stimulation in dorsal midbrain tegmentum on self-stimulation in hypothalamus and septal area

Four rats were implanted with chemical probes in dorsal midbrain tegmentum (DMT). Two of these had an electrode implanted in the septal area, while the other two had an electrode in hypothalamus. Minute quantities of carbachol (around 3 μgm) placed in DMT depressed self-stimulation in hypothalamus by over 90% and self-stimulation in septal area by 35%. The placement of sodium chloride, choline chloride, or an empty cannula into DMT had no effect on either septal or hypothalamic self-stimulation It was tentatively concluded that (1) a cholinergic system may exist in DMT, (2) that this system acted to suppress both septal and hypothalamic self-stimulation, and (3) that septal self-stimulation was suppressed less than hypothalamic self-stimulation perhaps because the former, in contrast to the latter, attenuated possible aversive effects of DMT stimulation.
Evolution of the vertebrate cytosolic malate dehydrogenase gene family: Duplication and divergence in actinopterygian fish

A general correlation between neural expression and negative charge in isozymes suggests charge represents an adaptation to the neural environment. Interestingly, a notable exception exists in teleost fish. Two cytosolic malate dehydrogenase (MDH) isozymes have different spatial expression patterns in certain fishes: one is expressed in all tissues and the second is expressed primarily in the eye and skeletal muscle. While the neural MDH isozyme is negatively charged, the difference in charge between the two isozymes is not as pronounced as that observed in other gene families (e.g., triosephosphate isomerase and lactate dehydrogenase). Most tetrapods express a single cytosolic MDH isozyme, and it has been demonstrated recently that the pair of isozymes found in teleosts results from a gene duplication sometime after the separation of teleosts and tetrapods, although the exact timing of this duplication has not been inferred. Phylogenetic analyses suggest that the duplication of teleost isozymes occurred during the radiation of actinopterygian fish, consistent with the timing of duplication at other loci. Using inferred amino acid sequences, we examine the pattern of change following the duplication and across the rest of the MDH gene tree. Comparison between the MDH gene family and another gene family that shows a larger charge differential among members (triosephosphate isomerase) indicates that the smaller charge difference between MDH isozymes is best explained by greater constraint on amino acid change directly following the duplication, not greater constraint across the entire gene tree. This difference in constraint might result from the wider pattern of expression of the "neural" MDH isozyme.
Algorithmic complexity of recursive and inductive algorithms

The main goal of this paper is to compare recursive algorithms such as Turing machines with such super-recursive algorithms as inductive Turing machines. This comparison is made in a general setting of dual complexity measures such as Kolmogorov or algorithmic complexity. To make adequate comparison, we reconsider the standard axiomatic approach to complexity of algorithms. The new approach allows us to achieve a more adequate representation of static system complexity in the axiomatic context. It is demonstrated that for solving many problems inductive Turing machines have much lower complexity than Turing machines and other recursive algorithms. Thus, inductive Turing machines are not only more powerful, but also more efficient than Turing machines.
Prolonged response to flutamide withdrawal and initiation of aminoglutethimide in a patient with metastatic prostate cancer

Objective. To present a patient with metastatic pros tate cancer who has experienced an extended re sponse to the withdrawal of flutamide and the con comitant initiation of aminoglutethimide.Case Summary. A 73-year-old male was diagnosed with advanced metastatic prostate cancer. He received treatment with suramin, leuprolide, and flutamide. After progressing on this regimen his flutamide was discon tinued and aminoglutethimide was initiated. His re sponse to this treatment has reached almost 3 years, with no evidence of progression.Discussion. The response to the withdrawal of flutamide is thought to arise from a mutated androgen receptor that recognizes hydroxyflutamide, the active metabolites of flutamide, as an agonist. The receptor continues to recognize endogenous steroids as agonists. The addition of the adrenal steroid synthesis inhibitor, aminoglutethimide may play a role in enhancing this response phenomenon.Conclusions. This patient is progression free for approximately 3 years following the wit...
Synthetic and Natural Speech Preferences of Male and Female Listeners in Four Age Groups

The purpose of this investigation was to examine the preferences of listeners of both sexes in four age groups with regard to natural and computer-generated synthetic speech in six different contexts. The subjects (listeners) for this study included 5 males and 5 females in each of four age groups (6–8 year olds, 10–12 year olds, adolescents, and adults). The listeners rated their preferences for 11 different voices (four natural and seven synthetic) on a 5-point Likert scale. Their preferences were rated for six communication contexts dependent on the potential user of the voice (adult male, adult female, child male, child female, computer, and self). The data were analyzed separately for each of the six communication contexts. In general, female listeners across the age range indicated that only natural female voices (adult or child) were acceptable alternatives to their own speech, thus rejecting the natural male voices as well as the synthetic voices. Male listeners appeared to be somewhat more flexib...
The distribution of lithium in selected soils and surface waters of the southeastern U.S.A.

Abstract The distribution of Li in the environment is not well documented although its geochemistry is thought to influence human health and agriculture. This study examined the distribution of Li in the soils and surface waters of the southeastern U.S.A., contrasting the Piedmont and Coastal Plain regions. Previous studies have been limited to total, and to a lesser extent exchangeable, soil Li, usually at a single soil depth. This study evaluated more carefully the distribution of Li between the soil solution, exchange, and solid phases, and its distribution within soil profiles. Total soil Li was found to correlate strongly with clay content, and ranged from 3.74 to 59.93 mg/kg. Exchangeable Li ranged from 0.1 to 21.8 μmol/kg soil and constituted an insignificant portion of the total exchangeable cations (
Leadership and Learning: Conceptualizing Relations between School Administrative Practice and Instructional Practice

In this paper I argue that one problem we face in understanding relations between school leadership and student learning is that core constructs in our work are often variably and weakly defined. Loose constructs pose problems because they contribute to fuzzy research, especially if constructs such as school leadership, management, or even instruction are weakly (or never explicitly) defined and operationalized. Fuzzy conceptualization makes comparing across studies, essential to the development of a robust empirical knowledge base, difficult if not impossible. Arguing that a critical but often overlooked challenge in studying relations between school administration and student learning is conceptual in nature, I begin by conceptualizing school administration and instruction from what I refer to as a distributed perspective, using theoretical work in distributed and situated cognition, activity theory, and micro sociology. I show how conceptualizing phenomena under study in particular ways shapes how we might frame and hypothesize relations among these phenomena. I contrast a distributed conceptualization with more conventional, individually focused conceptualizations of both phenomena. I then consider the entailments of my conceptualization of the two core phenomena for framing relations between them.
Location and function of retroviral and SV40 sequences that enhance biochemical transformation after microinjection of DNA.

Abstract Biochemical transformation of thymidine-kinase-deficient (TK − ) mouse L cells is enhanced 20 to 40 fold when microinjected plasmid DNA contains regions of the genomes of Rous sarcoma virus or simian virus 40 in addition to the complete herpes simplex virus tk gene, irrespective of the orientation and location of the enhancer. The enhancing sequence of RSV DNA has been localized to 143 bp that include 88 bp at the 5′ end of the long terminal repeat; the enhancing segment of SV40 DNA lies 42–276 bp upstream from the initiation site for early transcription. The RSV enhancer does not provide a favored integration site within microinjected plasmids and does not affect the frequency of integration into host cell DNA. When microinjected cells were grown into cell lines in nonselective medium, few cells containing integrated HSV tk without RSV DNA could grow in selective medium. In contrast, over 80% of cells from lines containing the HSV tk gene linked to the RSV enhancer could grow in selective medium. Thus the RSV enhancer affects the expression rather than the integration of the tk gene.
Excitotoxic lesions of the lateral parabrachial nucleus do not prevent cholecystokinin-induced suppression of milk intake in rats

We examined the effect of lateral (visceral) and medial (gustatory) parabrachial nucleus (PBN) lesions on the suppression of milk intake induced with cholecystokinin (CCK) in 24 h food-deprived rats. Irrespective of CCK dose, each type of PBN lesion significantly elevated the consumption of milk. Neither medial nor lateral PBN lesions had any discernible influence on the anorectic action of CCK, however. In combination with the results from a previous study using the same rats (Brain Res. 894 (2001) 288), the present results support the view that the role of the lateral PBN in CCK-induced anorexia depends on the nature of the food used at test.
Aegean and surrounding regions: Complex multiplate and continuum tectonics in a convergent zone

The tectonics of the Aegean region involves complex slip patterns across the boundaries of several microplates that segment the end of the Anatolian plate, which is moving in a westward direction from the Bitlis zone, an intracontinental suture zone, to consume oceanic lithosphere in the eastern Mediterranean. The segmentation of the western end of the Anatolian plate into scholles with adjacent zones of grabens, strike-slip, and thrust semicontinuum tectonics results from “locking’ across the two North Anatolian transform strands where they change orientation at the western end of the Sea of Marmara. This fast lateral motion of buoyant continental slivers is a transient phase of the early stages of continental collision resulting from the irregularity of colliding margins. It is, however, a tectonic phase that leaves a fundamental signature on the convergent zone by imprinting a complex widespread series of structures that mask, and make difficult the interpretation of, earlier structures.
Critical junctures and local agency: how Kosovo became independent

The determination of the political status of Kosovo is presented a case of path dependency. The article identifies a number critical junctures since summer 1999, arguing that there were a variety of options that would have led toward a settlement other than independence. These critical junctures included the October 2000 overthrow of Slobodan Milosevic; the March 2003 assassination of Zoran Đinđdic; the March 2005 indictment of Ramush Haradinaj; and the January 2007 Serbian parliamentary elections. Because of choices made primarily in Belgrade and Prishtina the process was driven toward a path that favoured independence. The article stresses the indeterminacy of the process at its start, as well as the importance of local agency.
T‐Cell Regulation of Immunoglobulin Synthesis and Proliferation in Pokeweed (Pa‐1)‐Stimulated Human Lymphocyte Cultures

In pokeweed (Pa-1)-stimulated human lymphocyte cultures, T cells are essential for the survival, proliferation, plasma-cell development, and high-rate Ig secretion of B cells. Their effects are T-cell-specific in the sense that B-cell stimulation does not take place in the absence of T cells even when fibroblasts or monocytes are provided. The experimental system is the most effective model for activation of human B lymphocytes so far described. Plasmablast development requires approximately 7 days in culture. In T + B-cell cultures established at 1 X 10(6)/ml (1 X 10(4)/mm2) initial cell density, plasma cells can secrete, on the average, as much as 40-70 pg IgM or IgG per cell per day. When the initial T-cell density is increased well above 1.0 X 10(6)/ml, a T-cell-mediated depression of Ig synthesis becomes predominant. Thus, in the pokeweed model T-cell effects represent a balance of helper and suppressor influences. The study also shows that B cells are heterogeneous. A non-adherent IgG-committed (smIg-?) TONSIL B-cell population seems to be less susceptible to T suppressor effects than normal tonsil B cells. This subset proliferates particularly well and synthesizes large quantities of IgG in the presence of large initial proportions of T cells.
The cell biology of parathyroid hormone in osteoblasts.

Continuous exposure to parathyroid hormone (PTH) is associated with catabolic effects, whereas intermittent exposure to low doses of PTH is associated with anabolic effects. By controlling osteoblast function, PTH increases bone formation on cancellous, endocortical, and periosteal bone surfaces. In general, PTH does not affect the replication of uncommitted osteoblast progenitors but suppresses proliferation of committed osteoprogenitors. Intermittent PTH promotes osteoblast differentiation, in part, by its ability to promote exit from the cell cycle, to activate Wnt signaling in osteoblasts, and to inhibit the Wnt antagonist sclerostin in osteocytes. Insulin-like growth factor-1 is also required for the actions of PTH to increase osteoblast numbers. Intermittent PTH prolongs osteoblast survival in rodents by mechanisms that involve activation and proteolytic degradation of Runx2. PTH’s ability to orchestrate a dynamic range of signaling cascades that determine osteoblast fate may explain both its catabolic and beneficial actions on the skeleton.
Adaptive algorithms for first principal eigenvector computation

The paper presents a unified framework to derive and analyze 10 different adaptive algorithms, some well-known, to compute the first principal eigenvector of the correlation matrix of a random vector sequence. Since adaptive principal eigenvector algorithms have originated from a diverse set of disciplines, including ad hoc methods, it is necessary to examine them in a unified framework. In a common framework consisting of five steps, we analyze the derivation, convergence, and rate results for many well-known algorithms as well as two new adaptive algorithms. In the process, we offer fresh perspectives on the known algorithms, and derive new results for others. The common framework also allows us to comparatively study the 10 algorithms. Finally, we show experimental results to support our analyses.
Spline estimation of generalised monotonic regression

We develop a simple and practical, yet flexible spline estimation method for semiparametric generalised linear models with monotonicity constraints. We propose to approximate the unknown monotone function by monotone B-splines, and employ generalised Rosen algorithm to compute the estimates. We show that the spline estimate of the nonparametric component achieves the optimal rate of convergence under the smooth condition, and that the estimates of regression parameters are asymptotically normal and efficient. The spline-based semiparametric likelihood ratio test (LRT) is also established. Moreover, a direct variance estimation method based on least-squares estimation is proposed. The finite sample performance of the spline estimates is evaluated by a Monte Carlo study. The methodology is illustrated on an air pollution study.
Stackless Multi-Threading for Embedded Systems

Programming support for multi-threaded applications on embedded microcontroller platforms has attracted a considerable amount of research attention in the recent years. This paper is focused on this problem, and presents UnStacked C , a source-to-source transformation that can translate multithreaded programs written in C into stackless continuations. The transformation can support legacy code by not requiring any changes to application code; only the underlying threading library needs modifications. We describe the details of UnStacked C in the context of the TinyOS operating system for wireless sensor network applications. We present a modified implementation of the TOSThreads library for TinyOS, and show how existing applications programmed using TOSThreads can be automatically transformed to use stackless threads with only modifications in the build process. By eliminating the need to allocate individual thread stacks and by supporting lazy thread preemption, UnStacked C enables a considerable saving of memory used and power consumed, respectively.
Deletion of exon 20 of the Familial Dysautonomia gene Ikbkap in mice causes developmental delay, cardiovascular defects, and early embryonic lethality.

Familial Dysautonomia (FD) is an autosomal recessive disorder that affects 1/3,600 live births in the Ashkenazi Jewish population, and leads to death before the age of 40. The disease is characterized by abnormal development and progressive degeneration of the sensory and autonomic nervous system. A single base pair substitution in intron 20 of the Ikbkap gene accounts for 98% of FD cases, and results in the expression of low levels of the full-length mRNA with simultaneous expression of an aberrantly spliced mRNA in which exon 20 is missing. To date, there is no animal model for the disease, and the essential cellular functions of IKAP - the protein encoded by Ikbkap - remain unknown. To better understand the normal function of IKAP and in an effort to generate a mouse model for FD, we have targeted the mouse Ikbkap gene by homologous recombination. We created two distinct alleles that result in either loss of Ikbkap expression, or expression of an mRNA lacking only exon 20. Homozygosity for either mutation leads to developmental delay, cardiovascular and brain malformations, accompanied with early embryonic lethality. Our analyses indicate that IKAP is essential for expression of specific genes involved in cardiac morphogenesis, and that cardiac failure is the likely cause of abnormal vascular development and embryonic lethality. Our results also indicate that deletion of exon 20 abolishes gene function. This implies that the truncated IKAP protein expressed in FD patients does not retain any significant biological function.
SU-FF-T-213: Evaluation of Dose From TomoTherapy Irradiation of Superficial PTVs

Purpose: To evaluate the accuracy of dose calculated by the TomoTherapy HI⋅ART treatment planning system for superficial planning target volumes (PTVs). Methods and Materials: TomoTherapy treatment plans were developed for three superficial PTVs (2−, 4−, and 6−cm deep radially by 90° azimuthally by 4−cm longitudinally) contoured on a 27−cm diameter cylindrical white opaque, high‐impact polystyrene phantom. The phantom included removable transverse and sagittal film cassettes. Kodak EDR2 films were cut using templates to match the phantom surface (±0.5mm). The phantom was aligned to the machine's isocenter (±0.5mm), and films were irradiated according to the treatment plans. Films were then scanned with a Vidar film digitizer and converted to dose using a calibration determined from a 6 MV perpendicular film exposure. Hence, axial film doses were scaled by 1.027 so that mid‐arc depth doses matched those measured in the sagittal plane. All film readings were scaled by 0.934 to correct for over response due to phantom Cerenkov light. Measured dose distributions were registered to calculated ones and compared. Results: For all PTVs, at depths less than 10mm calculated overestimated measured doses by as much as 8%. At depths greater than 10mm, the calculated and measured doses agreed to within 5%. In the dose falloff region, measured and calculated dose distributions agreed to within ±2mm. The calculated dose in the low dose region distal to the PTV was lower by as much as 2%. Each of these differences is related to an assumption in the dose model. Conclusion: Calculated dose distributions showed good agreement with measurement for depths greater than 10mm. For more superficial depths, the dose model should be carefully evaluated or one should use bolus of at least 10mm to ensure accurate calculated dose to superficial PTVs. Supported in part by a research agreement with TomoTherapy, Inc.
Consumer variety-seeking among goods and services: An integrative review

Abstract Reflecting the importance of variety-seeking in consumer choice, there has been an explosion of research in the marketing literature on this topic in the past decade. The goal of this paper is to provide an integrative review of the key findings. In particular, a conceptual, integrating framework for understanding the reasons why consumers seek variety is presented. Within this context, the implications of this research for retail and service management are discussed as well as a review of the measurement tools and predictive models of variety-seeking that have been proposed in the last decade.
Is complement good or bad for cancer patients? A new perspective on an old dilemma

Several studies of human cancers have established that chronic and insidious inflammation promotes the process of carcinogenesis and exacerbates the growth of existing tumors. Conversely, acute inflammation seems to have the opposite effect. Recent discoveries indicate that this dualism in the role of inflammation in cancer is mirrored by the effects of the complement system on this disease process. Previous studies have suggested that complement proteins can contribute to the immune surveillance of malignant tumors. However, a very recent study has indicated that complement proteins can also promote tumor growth. Here, we describe our current understanding of the role of complement in tumor development and progression.
Synthesis of aldehyde and carboxylic acid derivatives from 2‐hydroxymethyl‐3‐hydroxy‐4H‐pyran‐4‐one (α‐hydroxymaltol)

α-Hydroxymaltol (2-hydroxymethyl-3-hydroxy-4H-pyran-4-one) (1) has been converted to the 3-O-methyl ether 2 and 3-O-p-nitrobenzyl ether 4 by standard methods. The ethers 2 and 4 have been oxidized by barium manganate to the corresponding aldehydes, 3 and 5, in 91 and 77% yields respectively. Long-term reaction of 5 with hydrogen bromide in acetic acid gives 3-hydroxy-4H-pyran-4-one-2-carboxaldehyde (6). The aldehyde 3 is readily oxidized by short-term reaction with silver oxide to the corresponding acid 7.
A bioinformatics based approach to discover small RNA genes in the Escherichia coli genome.

Abstract The recent explosion in available bacterial genome sequences has initiated the need to improve an ability to annotate important sequence and structural elements in a fast, efficient and accurate manner. In particular, small non-coding RNAs (sRNAs) have been difficult to predict. The sRNAs play an important number of structural, catalytic and regulatory roles in the cell. Although a few groups have recently published prediction methods for annotating sRNAs in bacterial genome, much remains to be done in this field. Toward the goal of developing an efficient method for predicting unknown sRNA genes in the completed Escherichia coli genome, we adopted a bioinformatics approach to search for DNA regions that contain a σ70 promoter within a short distance of a rho-independent terminator. Among a total of 227 candidate sRNA genes initially identified, 32 were previously described sRNAs, orphan tRNAs, and partial tRNA and rRNA operons. Fifty-one are mRNAs genes encoding annotated extremely small open reading frames (ORFs) following an acceptable ribosome binding site. One hundred forty-four are potentially novel non-translatable sRNA genes. Using total RNA isolated from E. coli MG1655 cells grown under four different conditions, we verified transcripts of some of the genes by Northern hybridization. Here we summarize our data and discuss the rules and advantages/disadvantages of using this approach in annotating sRNA genes on bacterial genomes.
Effects of chronic administration of 7-benzylidene-7-dehydronaltrexone and naltriben on the antinociceptive actions of δ1- and δ2-opioid receptor agonists

The effects of chronic administration of 7-benzylidene-7-dehydronaltrexone, a delta 1-opioid receptor antagonist and naltriben, a delta 2-opioid receptor antagonist, on the antinociceptive responses to [D-Pen2, D-Pen5] enkephalin and [D-Ala2, Glu4]deltorphin II, delta 1- and delta 2-opioid receptor agonists, respectively, were determined in the mouse. Female B6C3F1 mice were given 7-benzylidene-7-dehydronaltrexone (3 mg/kg/day), naltriben (1 mg/kg/day) or the vehicle by subcutaneously implanted Alzet osmotic minipumps for 7 days. Both [D-Pen2, D-Pen5]enkephalin and [D-Ala2, Glu4]deltorphin II administered intracerebroventricularly (i.c.v.) produced antinociceptive as measured by the tail-flick test with ED50 values of 6.76 and 6.68 micrograms/mouse, respectively. Chronic administration of 7-benzylidene-7-dehydronaltrexone lowered the ED50 of [D-Pen2, D-Pen5]enkephalin but not of [D-Ala2, Glu4]deltorphin II. Chronic administration of naltriben lowered the ED50 of [D-Ala2, Glu4]deltorphin II but had no effect on the ED50 of [D-Pen2, D-Pen5]enkephalin. The binding of [3H][D-Pen2, D-Pen5]enkephalin to whole brain membranes of chronic 7-benzylidene-7-dehydronaltrexone-treated mice did not differ from chronic vehicle-treated mice. On the other hand, chronic administration of naltriben resulted in slight but reproducible elevation in the Bmax value of [3H][D-Pen2, D-Pen5]enkephalin to bind to whole brain membranes in comparison to vehicle-injected controls. The results suggest that chronic treatment with delta 1- and delta 2-opioid receptor antagonist cause behavioral supersensitivity to their agonists, respectively, and provides further evidence for the existence of delta-opioid receptor subtypes.
Trends in Residential Integration by Socioeconomic Status in Southern California.

The central question posed in this research is whether increased educational status and associated economic gains for black Americans have been translated into greater levels of residential integration in Southern California. Some recent national investigations have shown small decreases in the levels of separation for higher-status black Americans. The research in this study strengthens those findings and strongly suggests that social class differences, as measured by income and education, are important in explaining levels of separation and that when economic and educational gains do occur, these are translated into gains in residential integration.
Design and Validation of Four New Primers for Next-Generation Sequencing To Target the 18S rRNA Genes of Gastrointestinal Ciliate Protozoa

ABSTRACT Four new primers and one published primer were used to PCR amplify hypervariable regions within the protozoal 18S rRNA gene to determine which primer pair provided the best identification and statistical analysis. PCR amplicons of 394 to 498 bases were generated from three primer sets, sequenced using Roche 454 pyrosequencing with Titanium, and analyzed using the BLAST database (NCBI) and MOTHUR version 1.29. The protozoal diversity of rumen contents from moose in Alaska was assessed. In the present study, primer set 1, P-SSU-316F and GIC758R (amplicon of 482 bases), gave the best representation of diversity using BLAST classification, and the set amplified Entodinium simplex and Ostracodinium spp., which were not amplified by the other two primer sets. Primer set 2, GIC1080F and GIC1578R (amplicon of 498 bases), had similar BLAST results and a slightly higher percentage of sequences that were identified with a higher sequence identity. Primer sets 1 and 2 are recommended for use in ruminants. However, primer set 1 may be inadequate to determine protozoal diversity in nonruminants. The amplicons created by primer set 1 were indistinguishable for certain species within the genera Bandia, Blepharocorys, Polycosta, and Tetratoxum and between Hemiprorodon gymnoprosthium and Prorodonopsiscoli, none of which are normally found in the rumen.
Biochemical failure: role for early hormonal therapy

responses to radiotherapy [4]. Other variables used to establish the significance of a PSAonly recurrence include the time to recurrence (within or after 1–2 years) and the rate of change of PSA. The Center for Prostate Disease Recurrence (CPDR) data show that disease-free survival markedly differs in patients with a PSA-doubling time of > or < 12 months (Fig. 1). Overall, the main factors that help to distinguish between local and distant recurrences are summarized in Table 1.
Galanin is a physiological regulator of spontaneous pulsatile secretion of growth hormone in the male rat.

To determine whether galanin (GAL), a 29-amino acid neuropeptide, plays a role in the physiological regulation of the pulsatile secretion of GH and PRL in the male rat, secretory patterns of both hormones were studied in freely moving animals after GAL passive immunoneutralization. Adult male Sprague-Dawley rats were equipped with iv and intracerebroventricular catheters. After 7 days, 3 microliters of a specific GAL antiserum (GAL-AS) or normal rabbit serum (NRS; controls) were infused in the third ventricle of 10 rats, 25 and 1 h before the animals were bled every 15 min for 6 h (1000-1600 h). Plasma GH and PRL concentrations were measured by RIA, and the hormonal secretory patterns were analyzed by the PULSAR program. Control rats, treated with NRS, displayed typical GH secretion, with pulses of high amplitude (167 +/- 27 ng/ml) and low frequency (2.4 +/- 0.2 pulses/6 h), separated by periods of low trough levels (3.8 +/- 0.6 ng/ml). Rats treated with GAL-AS had altered pulsatile GH secretion. Pulse height was markedly reduced (77 +/- 15 ng/ml; P less than 0.01 vs. controls), and peak frequency was higher (3.6 +/- 0.5 pulses/6 h; P less than 0.05), while GH baseline levels and integrated GH secretion over the 6-h sampling period remained unaltered. Injection of rat GH-releasing hormone (1 microgram/rat, iv) caused a similar GH stimulation in both groups of rats, as determined by the peak GH response at 5 min (368 +/- 112 vs. 342 +/- 81 ng/ml) or by the integrated GH response over 1 h (5.13 +/- 1.30 vs. 4.77 +/- 1.15 micrograms.min/ml in NRS- and GAL-AS-treated rats, respectively; P less than 0.05). In contrast to GH, pulsatile secretion of PRL was not affected by the GAL-AS treatment. These results indicate that GAL is a physiological regulator of spontaneous pulsatile secretion of GH, but not PRL, in the male rat. The influence of GAL on GH secretion appears to be exerted within the hypothalamus, mainly by a stimulation of GRF secretion. However, the changes in GH pulse frequency observed after GAL immunoneutralization suggest that GAL might also influence the somatostatin inhibitory tone.
VIRGO-2K 2.25-μm HgCdTe dark current

Careful measurements for an engineering grade 2K2 2.5μm cut-off VIRGO detector in a sealed, cold enclosure have yielded dark current twenty five times less than previously reported for these devices, putting Raytheon detectors in contention for low background applications. Global reset followed by Sample Up the Ramp readout was used to allow zero point drifts at the exposure start to be separated from true dark current and mux glow. In a sub-array selected to be far from two photo-emitting defects, mean dark current stabilized 10 hours after power-on, at 0.025 e-/s/pix at 79K (-0.1K, +0.8K). Dark current showed no evidence of the onset of a floor in the 79-104K range, but the temperature dependence was softer than expected, implying a band gap that is 20% below nominal. Shot noise from the dark current will not dominate the 18 e- read noise, unless a substantial noise reduction is achieved through multiple sampling. Hundreds of non-destructive samples will be possible without impact from multiplexor glow, which contributes only 0.04e-/pix/read for a 6μs pixel. Reset Anomaly is dependent on exposure time, settling to -60e- for long exposures, and dominating dark current in exposures less than 2400s. Reference pixels do compensate for these effects, but imperfectly, requiring further study. Attempts to explain Reset Anomaly in terms of self heating were inconclusive.
Multitasking, Multilevel, Multimedia Software for Intermediate-Level French Language Instruction: "Ca Continue...".

Researchers and practitioners in the field alike cite the importance of in put from native speech in the language acquisition process. Whether one believes in a theoretical perspective emphasizing the value of input (Krashen 1981; 1982) or the dynamic interaction relation between input and output (Bialystok, 1978), there is little doubt that providing students with sufficiently interesting input material (readings, videos, etc.) in the target language can, if used properly, enhance student interest and subsequent language learning. An example of a multimedia program developed at Penn State using a videodisk selection (Teledouzaine, Francis Cabrel's “Encore et Encore,” PICS 1985) illustrates the use of authentic materials with potential for adaptations for various levels, tasks, and media. This particular software project fits in well with the newly designed technology classrooms and the French curriculum of a large IBM-funded multimedia undergraduate language program at Penn State, the Language 3 Initiative and can be used as a model for similar developments in the other languages involved in the Initiative and elsewhere.
An elementary proof of nonexistence of isometries between l p k and l q k

For k = 2, the two-dimensional coordinate spaces l12and l∞2 are isometric. Consequently, results on computational complexity for one space can be transplanted to the other in a natural way. In this note, an elementary proof is given for the nonisometry between lpk and lqk for general k, p, and q.
Afterglow of an e-beam discharge in several atmospheres of helium

Abstract Spectral observations of recombining helium afterglows at neutral pressures in the range 1 to 7 atmospheres and initial electron densities of 5 × 10 14 cm −3 are presented.
Catalytic Asymmetric Cyclopropanation Using Bridged Dirhodium Tetraprolinates on Solid Support

Dirhodium tetraprolinates in highly cross-linked macroporous polystyrene resins are very effective catalysts for asymmetric cyclopropanation using methyl aryldiazoaceates.