cssi/SciSciGPT-SciSciNet huggingface dataset:
Transport studies of showdomycin, nucleosides and sugars in Escherichia coli B and in showdomycin-resistant mutants

Competition between the nucleoside antibiotic, showdomycin, and certain naturally occurring nucleosides for a common transport system can explain the protective action of the nucleosides against inhibition by showdomycin of growth, amino acid transport and sugar transport in Escherichia coli B. Uridine interferes with the transport of showdomycin into the cell, thereby preventing the inhibitory effects of the antibiotic. With the exception of adenosine, nucleosides which protect against inhibition by showdomycin are mutually competitive for their transport. Guanosine, which does not protect against the inhibitory effect of showdomycin on glucose transport, does not compete for the transport of the protective nucleosides, uridine, cytidine or adenosine. Adenosine inhibits transport of uridine, cytidine and guanosine, but appears to have separate transport requirements. A mutant of E. coli B resistant to 80 μM showdomycin exhibits normal growth and glucose transport properties. The transport of uridine, cytidine and showdomycin is markedly reduced in the mutant, whereas guanosine and adenosine transport is similar to that in wild-type cells. Exogenous showdomycin, which inhibits transport of glucose, guanosine and protective nucleosides in E. coli B, has no effect on these processes in mutant cells. A defect in the capacity of the mutant to transport showdomycin explains the resistance of the mutant to the inhibitory effects of showdomycin. The inhibitory effects of N-ethylmaleimide, in contrast to showdomycin, are similar in mutant and E. coli B cells.
Geology: Fragmental debris

Lunar fragmental debris layer observations from Surveyor project, examining size, shape, texture, structure, etc
CCR5 Expression and β-Chemokine Production During Placental Neonatal Monocyte Differentiation

The stage of maturation of monocytes affects their susceptibility to HIV infection. The β-chemokines and their receptor CCR5 play a crucial role in inflammatory reactions and HIV infection. We therefore examined the correlation between the expression of CCR5 and β-chemokine production and the susceptibility to HIV infection during cord monocyte (CM) differentiation into macrophages. CM and CM-derived macrophages (CMDM) were examined for β-chemokine and CCR5 expression. The susceptibility of the CM cultured in vitro at different time points to HIV infection was also determined. Although the levels of CCR5 mRNA expression in freshly isolated CM are comparable to those in CMDM, CM had significantly lower levels of CCR5 protein on the cell surface than CMDM did. Steady increase of CCR5 protein expression on the cell surface was observed during CM differentiation into macrophages. The CCR5 expression correlated with the increased susceptibility to HIV infection by CMDM. Although there was no significant difference in endogenous β-chemokine production between CM and CMDM, HIV infection of CMDM significantly enhanced production of macrophage inflammatory protein-1α and -1β. CCR5 receptor plays a critical role in HIV infection of neonatal blood monocyte/macrophages.
Role of surface elasticity in capillary instability of cylindrical jets of nematic liquid crystalline polymers

We study the capillary instability of infinite cylindrical jets of nematic liquid crystal polymers (LCPs) using an approximate Doi theory for rodlike LCPs with an emphasis on the role of surface elasticity, arising from the potential discrepancy between the averaged molecular orientation in the bulk and the preferred surface orientation. Our analyses focus on the linear stability of two equilibrium (constant), cylindrical jets of distinctive preferred surface orientation patterns: the equilibrium jet of the axially aligned uniaxial director corresponding to the preferred tangential (planar) aligning at the jet free surface and the one of the radially aligned uniaxial director corresponding to the preferred normal (homeotropic) aligning at the surface. For the axially aligning jet, our results establish that the capillary instability persists for a finite band of wave numbers and the surface elasticity lowers the upper bound of the unstable wave number band (cutoff wave number), reduces the growthrate across the entire band of unstable wave numbers, and lengthens the wave length of the most unstable mode compared to our previous results in the absence of the surface elasticity. We then extend the study to the radially aligning jet and show that it shares the same stability properties of the axially aligning jet qualitatively. Quantitatively, however, the radially aligning jet suffers from a much greater growthrate and shorter wave length at the most unstable mode with the same set of physical parameters. In both cases, we demonstrate explicitly that the cutoff wave number varies inversely with respect to the uniaxial order parameter of the underlying equilibrium jet. This study extends the 1-D asymptotic (slender body) analysis of Rey [18] to a full 3-D, axisymmetric analysis with variable degree of orientation and meanwhile our early work to include the surface elasticity [10].
Construction of low noise optical correlation filters.

Filtres de correlation bases sur la fonction discriminante synthetique. Amelioration du rapport signal sur bruit
Modifiers of change in physical functioning in older adults with knee pain : The Observational Arthritis Study in Seniors (OASIS)

Objective To ascertain predictors of decline in physical functioning among older adults reporting knee pain. Methods The Observational Arthritis Study in Seniors was a longitudinal study of 480 adults over 65 years of age. Measurements of strength, sociodemographic characteristics, disease burden (including radiographic knee osteoarthritis [OA]), self-reported disability, and functional limitations were obtained on participants at baseline and at 15 and 30 months. Results Radiographic evidence of OA at baseline was moderately associated with an increased decline in both transfer (P = 0.06) and ambulatory-based performance tasks (P = 0.04) but not in self-reported disability. This effect disappeared after accounting for baseline levels of knee pain intensity and knee strength. Conclusion Knee pain intensity and knee strength may mediate the relationship between radiographic evidence of knee OA and change in performance. Although it is not clear whether joint disease precedes or follows a decline in muscular strength, these results may help to identify subpopulations of older persons with knee OA who may benefit from interventions aimed at slowing the progression of disability related to transfer and ambulatory-based tasks.
The Integrity of Esophagogastric Junction Anatomy in Patients with Isolated Laryngopharyngeal Reflux Symptoms

Distortion of esophagogastric junction anatomy in patients with gastroesophageal reflux disease produces permanent dilation of the gastric cardia proportional to disease severity, but it remains unclear whether this mechanism underlies reflux in patients with isolated laryngopharyngeal reflux symptoms. In a prospective study, 113 patients were stratified into three populations based on symptom complex: laryngopharyngeal reflux symptoms, typical reflux symptoms, and both laryngopharyngeal and typical symptoms. Subjects underwent small-caliber upper endoscopy in the upright position. Outcome measures included gastric cardia circumference, presence and size of hiatal hernia, and prevalence of esophagitis and Barrett’s esophagus within each group. There were no differences in gastric cardia circumference between patient groups. The prevalence of Barrett’s esophagus was 20.4% overall and 15.6% in pure laryngopharyngeal reflux patients. Barrett’s esophagus patients had a greater cardia circumference compared to those without it. In the upright position, patients with isolated laryngopharyngeal reflux display the same degree of esophagogastric junction distortion as those with typical reflux symptoms, suggesting a similar pathophysiology. This indicates that, although these patients may sense reflux differently, they have similar risks as patients with typical symptoms. Further, the identification of Barrett’s esophagus in the absence of typical reflux symptoms suggests the potential for occult disease progression and late discovery of cancer.
Fluticasone propionate and Salmeterol combination induces SOCS-3 expression in airway epithelial cells ☆

Fluticasone propionate (FP) and Salmeterol (SAL) are commonly used in combination therapy for patients with Chronic obstructive pulmonary disease (COPD). Clinical studies show that FP/SAL used in combination therapy was found to inhibit airway inflammation in COPD patients. However, the mechanisms associated with FP/SAL induced anti-inflammatory effects were not clear. We have evaluated the effect of FP/SAL and tobacco smoke (TS) on SOCS-3 and interleukine-6 expression in bronchial airway epithelial cells (BAEpCs). Human BAEpCs were exposed to TS and subsequently treated with FP or SAL alone or in combinations in the presence and absence of mitogen activated protein kinase (MAPK) inhibitors for either Erk1/Erk2, or p38 or PI3 kinase. In BAEpCs, TS induced IL-6 expression via ERK1/ERK2 MAPK pathway and FP/SAL inhibited TS mediated IL-6 expression. TS down regulated the SOCS-3 expression via activation of Erk1/Erk2, and p38 MAPK signaling. When TS exposed BAEpCs were treated with FP/SAL SOCS-3 expression was restored. FP/SAL combinations induced significantly higher expression of SOCS-3 in BAEpCs when compared to individual drug. Pretreatment with Ly294002 a PI3 MAPK inhibitor significantly attenuated FP/SAL induced SOCS-3 expression in BAEpCs. Furthermore, FP/SAL blunted TS induced phosphorylation of Erk1/Erk2 and p38 MAPK in BAEpCs. Our study suggests that TS inhibits SOCS-3, combination of FP/SAL has a profound synergistic effect on SOCS-3 induction in BAEpCs and it is dependent on PI3 kinase signaling pathway. SOCS-3 may represent a potential biomarker for understanding the efficacy and a novel anti-inflammatory mechanism of FP/SAL combination therapy in the treatment of COPD.
Analysis of the BCS ground state for a charge-independent pairing interaction

Abstract We analyse the nature of the approximations involved in the BCS method applied to a system of protons and neutrons in a single j-shell, interacting through a charge-independent pairing force, by comparing the trial BCS ground state wave function with the exact solution.
Risk factors and outcomes in postpancreaticoduodenectomy pancreaticocutaneous fistula

A significant fraction of patients undergoing pancreaticoduodenectomy develop a postoperative pancreaticocutaneous fistula. To identify risk factors for this complication and to delineate its impact on patient outcomes, we conducted a retrospective review of 1891 patients undergoing pancreaticoduodenectomy between 1981 and 2002. Overall, 216 patients (11.4%) developed a postoperative pancreaticocutaneous fistula. In univariate analysis, gender, coronary disease, diabetes mellitus, operative times, blood loss, radical lymphadenectomy, gland texture, and specimen pathology correlated with fistula rates. In a multivariate model, however, only gland texture and coronary disease were statistically predictive. A soft gland was associated with a 22.6% fistula rate, a 20.4-fold increase in fistula risk over those patients with a medium or firm gland (95% confidence interval, 4.7–90.9). No patient with a firm gland developed a fistula. Although 30-day postoperative mortality was not different between those patients with and those without fistula (1.4% versus 1.5%), the mean length of stay was longer (26.0 days versus 13.2 days) and the rates of certain complications were increased in those patients with fistula. In this single-institution experience, pancreaticocutaneous fistula was most strongly predicted by pancreatic texture. Choice of anastomotic technique did not correlate with fistula rates. Pancreaticocutaneous fistula increases postoperative length of stay and morbidity but was not directly associated with increased postoperative mortality.
Disseminated Aspergillosis Complicating Hepatic Failure

• Disseminated aspergillosis is not generally known as a complication of hepatic failure. Three patients with subacute hepatic necrosis died of clinically unrecognized disseminated aspergillosis. All of the patients had pulmonary aspergillosis andAspergillusinfections of the CNS. Focal neurologic deficits were clinically misconstrued as intracerebral hemorrhages caused by the coagulopathy of liver failure. Signs of invasive pulmonary aspergillosis were ascribed to refractory bacterial pneumonia. Each patient had a hospital course of longer than three weeks and each received treatment with corticosteroids and intravenous antibiotics. Invasive aspergillosis should be considered as a cause of refractory pneumonia and of new focal neurologic deficits in patients with hepatic failure. (Arch Intern Med1983;143:1189-1191)
Amphetamine and Methamphetamine Differentially Affect Dopamine Transporters in Vitro and in Vivo

The psychostimulants d-amphetamine (AMPH) and methamphetamine (METH) release excess dopamine (DA) into the synaptic clefts of dopaminergic neurons. Abnormal DA release is thought to occur by reverse transport through the DA transporter (DAT), and it is believed to underlie the severe behavioral effects of these drugs. Here we compare structurally similar AMPH and METH on DAT function in a heterologous expression system and in an animal model. In the in vitro expression system, DAT-mediated whole-cell currents were greater for METH stimulation than for AMPH. At the same voltage and concentration, METH released five times more DA than AMPH and did so at physiological membrane potentials. At maximally effective concentrations, METH released twice as much [Ca2+]i from internal stores compared with AMPH. [Ca2+]i responses to both drugs were independent of membrane voltage but inhibited by DAT antagonists. Intact phosphorylation sites in the N-terminal domain of DAT were required for the AMPH- and METH-induced increase in [Ca2+]i and for the enhanced effects of METH on [Ca2+]i elevation. Calmodulin-dependent protein kinase II and protein kinase C inhibitors alone or in combination also blocked AMPH- or METH-induced Ca2+ responses. Finally, in the rat nucleus accumbens, in vivo voltammetry showed that systemic application of METH inhibited DAT-mediated DA clearance more efficiently than AMPH, resulting in excess external DA. Together these data demonstrate that METH has a stronger effect on DAT-mediated cell physiology than AMPH, which may contribute to the euphoric and addictive properties of METH compared with AMPH.
Quantitation of metabolites in human skeletal muscle during rest and exercise: A comparison of methods

Quantitation of muscle metabolites in vastus lateralis needle biopsies from human subjects at rest and following exercise is evaluated using three different methods of normalization of the data, i.e., total protein, total creatine, and NAD+. Coefficients of variation between patient analyses are similar when the metabolite data are normalized by any of the descriptors in resting muscle and in muscle samples obtained following vigorous exercise. When multiple samples are taken from individual patients the intrapatient coefficient of variation is less than that for interpatient comparisons. Normalization to total creatine or NAD+ yields significantly smaller coefficients of variation than does normalization to total protein in these intrapatient comparisons (P less than 0.05). Based on these comparisons, we conclude that any of these methods evaluated for normalizing metabolite content is adequate for studying human subjects, but the total creatine and NAD+ methods may offer some advantage because of the lower variability obtained with these analyses.
Electron Heat Transfer in a Quiescent Nonequilibrium Plasma

An asymptotic solution has been obtained for the electron heat transfer to a spherical body immersed in a weakly ionized, quiescent plasma. Dimensional analysis of the governing equations shows that the problem can be divided into two regions: charge-separated and quasi-neutral. For the charge-separated region, the equations must be solved numerically, whereas the quasi-neutral solution can be expressed in closed form. From these studies it was found that the extent of the charge-separated region (i.e, sheath) is of the order of Λ2/3 . Within the sheath the effects of ionization and recombination are of the order of Λ4/3 . The results include the variation of electron flux, electron heat transfer, and current as a function of body potential. The results are presented in a form to permit the easy determination of the electron heat transfer to a body immersed in a quiescent, weakly ionized plasma over a wide range of operating conditions. Furthermore, the electrical characteristics presented here can be used in conjunction with electron heating data to treat the body as a probe for diagnostic purposes.
Potential Energy Surface of SOCl3

Sulfur trichloride monoxide anion (SOCl3-) is stable in the gas phase. The G2 estimate of the energy for its dissociation to thionyl chloride and chloride anion is 102.8 kJ mol-1. The potential energy surface for the reaction SOCl2 + Cl- → SOCl3- has just a single well corresponding to the product. Collision-induced dissociation observed using a flowing afterglow-tandem mass spectrometer indicates a D0(SOCl2−Cl-) bond energy of 85.4 ± 7.6 kJ mol-1, which is very similar to the previously determined bond energy D0(SCl2−Cl-) = 85 kJ mol-1.
Electrolytic preparation of gem-dinitroparaffins

Abstract A convenient electrolytic method for the preparation of simple gem-dinitroparaffins has been found. The first step in the reaction is the electrolytic oxidation of a silver anode to silver ions. In the preparation of 1,1-dinitroethane, the silver ions react in the anode compartment of the electrolysis cell with nitrite and ethylnitronate ions to form the potassium salt of dinitroethane in solution and silver metal on the surface of the electrode. The product can be separated in highly pure form by crystallization from the anode solution. The reaction variables have been investigated and a unique electrolysis cell, containing a bed of powdered silver as the anode, has been designed. This cell permits continuous operation without loss of silver from the anode. A mechanism for the reaction, involving an intermediate complex containing ethylnitronate, nitrite and silver ions in a ratio of 1:1:2 has been postulated. 1,1-Dinitropropane and 2,2-dinitropropane have been prepared by analogous reactions.
Unimolecular dissociation of energy-selected t-butylbenzene ions and effect of thermal energy on data analysis

Abstract The technique of threshold photoelectron-photoion coincidence (PEPICO) spectroscopy has been used to determine unimolecular rate constants for CH 3 loss from the molecular ion of t -butylbenzene. It is shown that in such large molecules the actual distribution of the thermal internal energy must be taken into account in order to extract accurate k(E) values near the threshold for decomposition. A simple method is presented for the inclusion of thermal energy in the calculations for the extraction of the rate constants. The k(E) function derived is compared to one obtained from field-ionization kinetics measurements and to RRKM/QET calculations.
Formation of the isocyclic ring of chlorophyll by isolated Chlamydomonas reinhardtii chloroplasts.

Chlamydomonas reinhardtii chloroplasts catalyzed two sequential steps of Chl biosynthesis, S-adenosyl-l-methionine:Mg-protoporphyrin IX methyltransferase and Mg-protoporphyrin IX monomethyl ester oxidative cyclase. A double mutant strain of C. reinhardtii was constructed which has a cell wall deficiency and is unable to form chlorophyll in the dark. Dark-grown cells were disrupted with a BioNeb nebulizer under conditions which lysed the plasma membrane but not the chloroplast envelope. Chloroplasts were purified by Percoll density gradient centrifugation. The purified chloroplasts were used to define components required for the biosynthesis of Mg-2,4-divinylpheoporphyrin a5 (divinyl protochlorophyllide) from Mg-protoporphyrin IX. Product formation requires the addition of Mg-protoporphyrin IX, the substrate for S-adenosyl-l-methionine:Mg-protoporphyrin IX methyltransferase which produces Mg-protoporphyrin IX monomethyl ester. The Mg-protoporphyrin IX monomethyl ester that is generated in situ is the substrate for Mg-protoporphyrin IX monomethyl ester oxidative cyclase. The reaction product was identified as Mg-2,4-divinylpheoporphyrin a5 (divinyl protochlorophyllide) by excitation and emission spectrofluorometry and HPLC on ion-paired reverse-phase and polyethylene columns. Mg-2,4-divinylpheoporphyrin a5 formation by the coupled enzyme system required O2 and was stimulated by the addition of NADP+, an NADPH regenerating system, and S-adenosyl-l-methionine. Product was formed at a relatively steady rate for at least 60 min.
Large-scale chemical dissection of mitochondrial function

Mitochondrial oxidative phosphorylation (OXPHOS) is under the control of both mitochondrial (mtDNA) and nuclear genomes and is central to energy homeostasis. To investigate how its function and regulation are integrated within cells, we systematically combined four cell-based assays of OXPHOS physiology with multiplexed measurements of nuclear and mtDNA gene expression across 2,490 small-molecule perturbations in cultured muscle. Mining the resulting compendium revealed, first, that protein synthesis inhibitors can decouple coordination of nuclear and mtDNA transcription; second, that a subset of HMG-CoA reductase inhibitors, combined with propranolol, can cause mitochondrial toxicity, yielding potential clues about the etiology of statin myopathy; and, third, that structurally diverse microtubule inhibitors stimulate OXPHOS transcription while suppressing reactive oxygen species, via a transcriptional mechanism involving PGC-1α and ERRα, and thus may be useful in treating age-associated degenerative disorders. Our screening compendium can be used as a discovery tool both for understanding mitochondrial biology and toxicity and for identifying novel therapeutics.
Proof of the squashed cube conjecture

We prove a conjecture of R. L. Graham and H. O. Pollak to the effect that every connected graph onn vertices has a distance-preserving embedding in “squashed cube” of dimensionn−1. This means that to each vertex of the graph a string ofn−1 symbols from the alphabet {0, 1, *} can be assigned in such a way that the length of the shortest path between two vertices is equal to the Hamming distance between the corresponding strings, with * being regarded as at distance zero from either 1 or 0. Our labelling thus provides an efficient addressing scheme for the loop-switching communications system proposed by J. R. Pierce.
"Face-to-face with It": medical students' narratives about their end-of-life education.

Medical schools have been slow to include meaningful end-of-life (EOL) educational experiences in their curricula. As an area of inquiry and focused clinical experience, death is "conspicuous" by its absence, reflecting a medical culture that defines death as failure. The author asked fourth-year medical students at one institution to describe their experiences with dying patients and their families, the skills and attitudes they brought to these encounters, the support they received from attendings and residents while caring for dying patients, and suggestions for the medical curriculum that would help prepare them for care of the dying. Using a qualitative method, she analyzed ten students' written narratives, which dealt with experiences during their third-year clerkships, and compared these reflections with the literature on EOL care in medical education. The themes that emerged provided four organizers for this essay: (1) students' worry and uncertainty about EOL care, (2) guidance and role modeling in EOL care, (3) preparation for EOL care, and (4) conclusions and recommendations for the medical curriculum. In general, students did not feel well prepared or supported as they cared for their first dying patients, including, for example, delivering a terminal prognosis or obtaining a DNR. However, while they did wish for more support and role modeling from residents and attendings, they generally believed that care of the dying can be learned only through direct clinical experience. These beliefs call into question curricular issues of placement of EOL inquiry--most often in the preclinical curriculum--and the teaching of its content, currently overwhelmingly by lectures. The author concludes with recommendations for thoughtful, integrative, interdisciplinary curriculum changes in EOL education.
EFFECTS OF INQUIRY METHODS AND AMBIGUITY TOLERANCE ON PREDICTION PERFORMANCE

This study examined the comparative effectiveness of four inquiry methods on a financial prediction task. Inquiry methods included the expert (E), devil's advocate (DA), and dialectical inquiry (DI) techniques as well as a combined devil's advocate-dialectical inquiry (DADI) technique. Also, the moderating effects of ambiguity tolerance were considered. Results indicated that when the state of the world was opposite to the assumptions underlying a plan, the DA, DI, and DADI approaches were all superior to the E approach. Further, for high ambiguity-tolerance subjects, the DA and DADI approaches led to significantly better prediction performance than the E approach, and the superiority of the DADI approach over the DI approach was marginally significant. Results suggest that decision makers' levels of ambiguity tolerance should be considered before recommending their use of either the DA or DADI approach as an ill-structured decision-making aid.
Interfacial dynamics for Stokes flow

Theoretical and computational aspects of the method of interfacial dynamics for flow at vanishing Reynolds number are considered. The mathematical formulation relies on the boundary-integral representation that expresses the flow in terms of distributions of Stokes-flow singularities over the interfaces. The densities of the distributions are identified with the jump in the hydrodynamic traction due to interfacial in-plane and transverse tensions, the interfacial velocity, or the strength of a hydrodynamic potential. The numerical procedure involves describing the interfaces in terms of interfacial marker points that reproduce the evolving shapes of the interfaces by global or local interpolation; solving integral equations of the second kind for the interfacial velocity or for the density of a hydrodynamic potential; and computing the motion of the marker points while simultaneously updating interfacial fields relevant to the dynamics, including the concentration of a surfactant and the position of interfacial point particles at an equilibrium configuration. Interfaces exhibiting isotropic tension, elastic tensions, viscous, and incompressible behavior are considered. The mathematical modeling of the tensions and bending moments developing over interfaces with a membrane-like constitution is discussed in the context of the theory of thin shells. To facilitate the numerical implementation, the coupling of the interfacial mechanics to the hydrodynamics by means of interface force and torque balances is formulated in global Cartesian coordinates. Recent progress in the implementation of boundary-element methods is reviewed, and areas for further research are identified.
Modeling of the monotonic and cyclic swift effects using anisotropic finite viscoplasticity theory based on overstress (AFVBO): Part I - Constitutive model

Abstract The isotropic finite viscoplasticity theory based on overstress (FVBO) is extended to anisotropy. It is accomplished by formulating an anisotropic flow law, which consists of a fourth order inelastic compliance tensor. Since large inelastic deformation causes a change in the microstructure, the aforementioned tensor is allowed to evolve according to the Frederick–Armstrong type law during inelastic deformation. Additive decomposition of the rate of deformation into elastic and inelastic parts is assumed. The current configuration is taken as a reference configuration.
Overwintering of Trichogramma pretiosum in central Texas.

In central Texas, Trichogramma pretiosum Riley successfully overwintered within eggs of the tobacco budworm, Heliothis virescens (F.), and the Angoumois grain moth, Sitotroga cerealella (Olivier). All T. pretiosum in host eggs exposed before mid-Nov. produced adults before early Jan. Overwintering individuals developed from host eggs parasitized between mid-Nov. and early Jan. Some overwintering parasites emerged during warm periods in Jan., but few parasites emerged from host eggs exposed in Jan. Most overwintering parasites emerged from early Feb. to mid-Mar. In these 2 hosts, which do not overwinter as eggs, T. pretiosum overwintered in the immature stages at a reduced rate of development. Temperature was probably the primary factor regulating the pattern of development and adult emergence.
Products of central collineations

Abstract An n by n matrix M over a (commutative) field F is said to be central if M − I has rank 1. We say that M is an involution if M 2 = I ; if M is also central we call M a simple involution . We will prove that any n -by- n matrix M satisfying det M =±1 is the product of n +2 or fewer simple involutions. This can be reduced to n +1 if F contains no roots of the equation x n =(−1) n other than ±1. Any ordered field is of this kind. Our main result is that if M is any n -by- n nonsingular nonscalar matrix and if x i ∈ F such that x 1 ⋯ x n =det M , then there exist central matrices M i such that M = M 1 ⋯ M n and x i =det M i for i =1,…, n . We will apply this result to the projective group PGL( n,F ) and to the little projective group PSL( n,F ).
The role of cold-core Gulf Stream rings in the temporal and spatial patterns of euthecosomatous pteropods

Abstract Diel vertical distributions and seasonal variations in abundance of three species of euthecosomatous pteropods characteristics of the Slope Water Region and two warm-water species are presented for two cold-core rings of the Gulf Stream. The cold-water species, Limacina retroversa, disappears from the cold-core rings within the first 5 months. One warm-water species, L. inflata, shows population increases of more than an order of magnitude within 5 months and then a decline to background Sargasso Sea levels. Daytime depths for this latter migratory species suggest a shallower migration in young to middle age cold-core rings.
Radioimmunoassay procedure for quantitating bacterial antibody in human sera

A RIA system was developed to detect antibodies in human sera against bacteria. Sonicates of Escherichia coli and Fusobacterium polymorphum were used as antigens to sensitize plastic-coated beads; antibodies to these antigens were detected with 125I-labeled antihuman globulin. Serum antibody titers against E. coli were determined by the serial dilution method; from the results the standard curve principle was applied in determining the relative amounts of antibodies against E. coli in serum samples tested at a single dilution. The coefficient of variation of the RIA procedure was less than 10%. Serum titers obtained by the RIA and indirect immunofluorescence test were compared; RIA was more sensitive, quantitative and objective. Absorption studies, using E. coli and F. polymorphum absorbentes against E. coli and F. polymorphum. This RIA procedure offers a combination of desirable advantages; it is sensitive, specific, objective, quantitative, and easy to perform.
Effects of Simultaneous and Successive Stimulus Presentation on Visual Discriminations by Aphasic Patients

In order to determine whether aphasic and nonaphasic subjects would perform differentially in simultaneous and successive discrimination tasks, 10 aphasic and 10 nonaphasic hospital patients perfor...
An efficient single unit T-box/T-1-box implementation for 128-bit AES on FPGA

In this paper, we present an area efficient Block RAM BRAM-based single unit design of T-box/T-1-box on a Field Programmable Gate Array FPGA for combined Advanced Encryption Standard AES encryption and decryption. Conventional FPGA designs for T-box module not only utilize several BRAMs for 16bytes parallel look-up operations but also because of asymmetric nature of AES, use separate hardware for T-1-box unit in decryption process. Alternatively in iterative architecture, BRAM in dual-port mode configuration takes eight clock cycles to access 16 look-up operations from a T-box because of its synchronous nature. Thus, resulting in an unoptimized solution not only in term of FPGA resources but also results in high latency for iterative architecture. Our proposed design uses single symmetric T-box/T-1-box table with same set of single resource-shared hardware for both the encryptor and decryptor and at the same time performs eight look-up operations from single BRAM in one clock cycle using efficient BRAM switching technique instead of using multirated clocking. Our complete 128-bit symmetric T-box/T-1-box design fits into just 2 BRAMs and 136 Slices. It occupies lowest area reported to date with 50% power saving and highest Throughput Per Slice TPS of 10.77. Copyright © 2014 John Wiley & Sons, Ltd.
Unfavorable electrostatic and steric interactions in DNA polymerase β E295K mutant interfere with the enzyme's pathway.

Mutations in DNA polymerase β (pol β) have been associated with approximately 30% of human tumors. The E295K mutation of pol β has been linked to gastric carcinoma via interference with base excision repair. To interpret the different behavior of E295K as compared to wild-type pol β in atomic and energetic detail, we resolve a binary crystal complex of E295K at 2.5 A and apply transition path sampling (TPS) to delineate the closing pathway of the E295K pol β mutant. Conformational changes are important components in the enzymatic pathway that lead to and ready the enzyme for the chemical reaction. Our analyses show that the closing pathway of E295K mutant differs from the wild-type pol β in terms of the individual transition states along the pathway, associated energies, and the active site conformation in the final closed form of the mutant. In particular, the closed state of E295K has a more distorted active site than the active site in the wild-type pol β. In addition, the total energy barrier in the conformational closing pathway is 65 ± 11 kJ/mol, much higher than that estimated for both correct (e.g., G:C) and incorrect (e.g., G:A) wild-type pol β systems (42 ± 8 and 45 ± 7 kJ/mol, respectively). In particular, the rotation of Arg258 is the rate-limiting step in the conformational pathway of E295K due to unfavorable electrostatic and steric interactions. The distorted active site in the closed relative to open state and the high energy barrier in the conformational pathway may explain in part why the E295K mutant is observed to be inactive. Interestingly, however, following the closing of the thumb but prior to the rotation of Arg258, the E295K mutant complex has a similar energy level as compared to the wild-type pol β. This suggests that the E295K mutant may associate with DNA with similar affinity, but it may be hampered in continuing the process of chemistry. Supporting experimental data come from the observation that the catalytic activity of wild-type pol β is hampered when E295K is present: this may arise from the competition between E295K and wild-type enzyme for the DNA. These combined results suggest that the low insertion efficiency of E295K mutant as compared to wild-type pol β may be related to a closed form distorted by unfavorable electrostatic and steric interactions between Arg258 and other key residues. The active site is thus less competent for proceeding to the chemical reaction, which may also involve a higher reaction barrier than the wild-type or may not be possible in this mutant. Our analysis also suggests further experiments for other mutants to test the above hypothesis and dissect the roles of steric and electrostatic factors on enzyme behavior.
Characterization of irradiance effects on curing of siloxane for embedded waveguide applications

In order to maintain the overall optical performance in a step index rectangular waveguide, the complex index of refraction of the core and cladding material must be maintained throughout the cycle of the lithographic fabrication process. The percentage of the core and cladding material that is cured and the irradiance that cure took place directly affects the complex index of refraction of these materials. Siloxanes produced by Dow Corning have been selected to meet the requirements for embedded waveguides for circuit board applications due to their optical performance characteristics and their compatibility with current manufacturing techniques. The required total dose for a 50 μm thick layer of siloxane is 1200 mJ at an irradiance of 30 mW/cm2. In order to utilize lower irradiance levels the total dose of the ultraviolet exposure must be characterized and calibrated. By measuring the changes in the absorption peaks of the materials using transmission data from ellipsometric techniques it is possible to define the percentage cure of the siloxane from different curing profiles. Ellipsometric techniques were also utilized to measure the complex refractive index of the materials cured using different profiles. It was found that the total dose required for a complete cure and the complex refractive index of these materials drastically changes with different irradiances and the profile for the total dose compared to the curing of the siloxane materials at all irradiances is logarithmic.
Synthesis, Structure, and Cyclic Voltammetry of 4,6-Bis(dimesitylboryl)dibenzofuran: Isolation of 4,6-Dilithiobenzofuran and 4,5-Dilithio-9,9-dimethylxanthene as tmeda Adducts

The reaction of dibenzofuran and 9,9-dimethylxanthene with sec-BuLi and n-BuLi, respectively, in the presence of N,N,N‘,N‘-tetramethylethylenediamine (tmeda) in hexane followed by storage at −20 °C results in the precipitation of 4,6-dilithiodibenzofuran-1.5(tmeda) (1) and 4,5-dilithio-9,9-dimethylxanthene-1.5(tmeda) (2). Both of these adducts form tetranuclear dimers with the lithium atoms bridging the deprotonated aromatic ligands. The reaction of 1 with dimesitylboronfluoride affords 4,6-bis(dimesitylboryl)dibenzofuran (3), which has been fully characterized. Cyclic voltammetry of compound 3 shows two reduction waves at E1/2 −2.45 and −2.81 V (vs Fc/Fc+), which substantiates significant electronic coupling of the two boron centers. Computational studies show that the p-orbital of the two boron centers participates equally to the LUMO, thus providing grounds for the observed electronic coupling.
CF effects and disorder versus Kondo lattice behavior in CeTSi 3 (T=Rh,Ir)

On the basis of specific heat, magnetic susceptibility and electrical resistivity measurements, CeTSi3 (T=Rh,Ir) have recently been characterized as magnetically ordered Kondo lattice compounds. However, no magnetic Bragg peaks could be observed by powder neutron diffraction, resulting in an upper limit of the ordered magnetic moment of 0.25 μB. An additional quasi-elastic neutron scattering study on CeRhSi3 did not reveal any appreciable magnetic signal at low temperatures (T≤40 K) and only very weak scattering contributions at elevated temperatures (80 K≤T≤300 K). For a proper characterization of CeMSi3 (M=Rh,Ir), we propose the inclusion of crystal-field (CF) effects and nonmagnetic atomic disorder. This may also hold true for other compounds of the CeTX3 (T = transition metal, X = Si, Ge) intermetallics showing similar magnetic behavior.
Unusual presentations of food allergy

Objective This presentation is designed to critically review information on presentations of food hypersensitivity reactions that may be considered unusual regarding the source or nature of allergen, route of exposure, or clinical manifestation. Data Sources Information has been gathered primarily through a thorough search of the English literature relevant to human subjects. Some clinical cases were also included from the author's own clinical experience. Study Selection Information summarized here was critically selected on the basis of proven or acceptable scientific validity. Results The findings indicate that food allergy presentation can be unusual in three main aspects. First, the offending allergen may not be the obvious food that was ingested or be a food protein incorporated in a nonfood product. Second, systemic reactions can be provoked by very minute quantities of food allergens that may even get access through noningestant routes, eg, inhalation, odor, skin contact, or mucous membrane contact. Third, the clinical manifestations are not limited to the few gastrointestinal, cutaneous, and respiratory symptoms with which we are generally familiar. Conclusions The extent of food allergy presentation is more than has been generally realized. Our awareness of such unusual presentations adds new knowledge and should prompt our interest in carefully evaluating patients with obscure allergic reactions for possible food allergy.
An algorithm for modeling non-linear system effects in iterative CT reconstruction

With continued development and clinical deployment of iterative algorithms for CT, there remain many open questions about the best way to model various physical effects that degrade CT images, including geometric effects (finite sized detectors and sources), spectral effects due to the use of polychromatic spectra, scattered radiation, and noise. In this paper, we focus on the question of geometric modeling. Some recent investigations have concluded that geometric modeling may be unnecessary, with simple point source and point detector models yielding good results as measured near the isocenter of images. We further investigate this question in the present work, paying particular attention to peripheral image quality, where we find the effects of modeling to be more significant than at the isocenter. We also seek to evaluate the question of whether nonlinear modeling, which more closely captures the way CT data are acquired, offers any advantage over the traditional linear modeling used in iterative CT algorithms. In order to more accurately model the averaging in the transmitted intensity domain, we derive an update equation using separable paraboloidal surrogates (SPS) that is able to model a finite source, finite detectors, and data acquired over a small angular trajectory. We model these effects by incorporating many "beamlets" into the imaging model. In this work, we compare reconstructions made with additional modeling and without modeling in an SPS algorithm. We find that while modeling geometry makes a significant impact on the reconstructed image, a non-linear model may not be worth the additional computational cost.
Chimaerism in the immune system of tetraparental mice.

TETRAPARENTAL mice, formed by combining two eight-cell embryos derived from different inbred strains1,2, have been used for a variety of immunological studies3,6. These animals have immune cells capable of destroying both parental cell lines and specific blocking factors in the serum capable of preventing such destruction3,4. In view of this surprising result, it is desirable to clarify the nature of the chimaerism in the immune organs of these mice. One important point is whether a tetraparental mouse could have a mixed spleen, but a thymus derived from only one parent. This would also have implications for the development of these organs. As a first step in this direction we have fused pairs of embryos differing by a cyto-logically distinct chromosome marker, the T6 chromosome7. By examining cells in mitosis in the resultant adult thymus, spleen and bone marrow, we have found that within each animal the ratio of the two cell types is remarkably constant from organ to organ although it varies extensively from one animal to another.
Failure by engorged stages of the lone star tick, Amblyomma americanum, to react to assembly pheromone, guanine and uric acid

Response to tick-exposed filter paper discs (tick excreta) by fed and non-fed stages of the lone star tick Amblyomma americanum (L.) (Acari: Ixodidae) was examined from larva to adult. By contrast with engorged stages, each non-fed stage exhibited a classic arrestment response to assembly pheromone, characterized by lack of movement, retraction of legs and formation of small groups; this response was seen in approximately 75% of ticks that made contact with pheromone-treated surfaces. Less pronounced arrestment (by approximately 66% of ticks) was elicited by (0.001-0.005 M) guanine as the active pheromonal ingredient and by uric acid, a chief excretory product of birds. Lack of response to arrestment cues post-engorgement suggests that this response is kairomonal where guanine mimics uric acid as a host cue that signals immature A. americanum's preferred bird host. The functional overlap simultaneously favours tick retention in areas with an abundance of successful ticks, signalled by a heavy bout of excretion (guanine) soon after hatching and moulting. Control significance pertains to the use of these compounds as trap arrestants, but not attractants, with advantages in effectiveness against any non-fed stage.
Gender Differences in Depression in Children as a Function of Motivational Orientation.

Based on previous theoretical and empirical analyses, the present study examined two hypotheses. First, we hypothesized that children who have an extrinsic motivational orientation, i.e., children who perform schoolwork for approval or fear of evaluation, would be more depressed than intrinsics, who are generally more interested in learning and exhibit the desire to obtain mastery over challenge. Second, based on data showing that girls are more likely to be extrinsic than boys, we hypothesized that girls would also be more depressed than their male counterparts. The data proved strong support for the hypotheses. In our discussion, we highlight the need for further research to examine the causal relation among motivational orientation, gender, and depression to develop social-developmental theories and clinical interventions for depressed, extrinsic girls and boys.
How various malt endoproteinase classes affect wort soluble protein levels

Abstract During the germination of seeds, storage proteins are degraded and the resulting amino acids are utilized by the growing seedling. In barley, this process is commercially important because it forms the basis for the malting and brewing industries. In this study, barleys and malts were mashed in the presence of compounds that specifically inhibited the four common proteinase classes. The efficacies of the proteinases in solubilizing proteins were in the order cysteine≈metallo>aspartic>serine≈0, which roughly reflected how the inhibitors affected the mash endoproteolytic activities. It was previously believed that only the cysteine enzymes were involved. All four enzyme classes affected the free amino nitrogen concentration but none altered any of the other measured wort characteristics. With either single inhibitors or inhibitor mixtures, the effect of pH was as expected, based on earlier studies that indicated that cysteine and aspartic proteinases were most active at low pH values and the metalloproteinases were only active at high pH. At the North American commercial mashing pH of 6.0, about one third of the soluble protein of a typical wort came from ungerminated barley, half was solubilized during malting and the remaining 22% was released during mashing.