cssi/SciSciGPT-SciSciNet huggingface dataset:
A convenient, rapid method for the resolution of enantiomeric amino acids using chiral phases on stainless-steel capillary gas chromatographic columns.

Abstract An improved method is described for the resolution of enantiomeric isopropyl esters of N -trifluoroacetyl-α-amino acids of nonbasic amino acids using N -docosanoyl- l -valyl- t -butylamide and N -octadecanoyl- l -valyl- l -valine cyclohexyl ester as mixed chiral phases on 150-ft stainless-steel capillary columns. Enantiomers of Ala, Val, Ile, Leu, Ser, Thr, Asp, Met, Glu, and Phe are resolved in 105 min. This method avoids the fractionation problems and high costs encountered with the diastereometric method and difficulties and costs encountered in loading and maintaining glass capillary columns. It is particularly useful for studies involving a large number of resolutions as in a study of the kinetics of racemization of amino acids.
Phenanthrene release from natural organic matter surrogates under simulated human gastrointestinal conditions.

Abstract The aliphatic region of natural organic matter (NOM) can retain polycyclic aromatic hydrocarbons (PAH) due to the presence of non-polar binding sites. Thus NOM may act as a vehicle for entry of PAH into the gastrointestinal system in man and animals. In this study, the release of phenanthrene from the aliphatic NOM surrogates cutin and cutan was measured under simulated human gastrointestinal formulations using three treatments designed to simulate the biological and chemical conditions of the gastrointestinal environment. The three experimental treatments were composed of fecal microorganisms, chyme, and chyme+fecal microorganisms. Water was used as a control treatment. Phenanthrene laden biopolymer and a C18 membrane were immersed in each treatment. Phenanthrene was extracted from each membrane and measured with HPLC. Membrane-associated phenanthrene was taken to represent the fraction that had desorbed from the biopolymer. Cutin was found to yield an average phenanthrene release 55% higher than cutan (94% vs. 39%). A significant decrease ( p 0.05 ) in phenanthrene release was observed in both the chyme and chyme+fecal microorganism treatments as compared to the water treatment (control). The presence of enteric microorganisms did not significantly influence phenanthrene release and did not reduce phenanthrene bioaccessibility in gastrointestinal chyme. Over 80% of the phenanthrene in cutin was recovered in the C18 matrix and its relative amount was uninfluenced by the treatments. For cutan, only 25–50% of the phenanthrene was recovered, suggesting that cutin-associated phenanthrene was more loosely bound. These data demonstrate that the fractions of NOM retained phenanthrene to a varying extent and thus the predictions of phenanthrene bioavailability should also be assessed on the basis of the constituents of the NOM matrix.
Induction of Alloantigen-specific Anergy in Human Peripheral Blood Mononuclear Cells by Alloantigen Stimulation with Co-stimulatory Signal Blockade

Allogeneic hematopoietic stem cell transplantation (AHSCT) offers the best chance of cure for many patients with congenital and acquired hematologic diseases. Unfortunately, transplantation of alloreactive donor T cells which recognize and damage healthy patient tissues can result in Graft-versus-Host Disease (GvHD)1. One challenge to successful AHSCT is the prevention of GvHD without associated impairment of the beneficial effects of donor T cells, particularly immune reconstitution and prevention of relapse. GvHD can be prevented by non-specific depletion of donor T cells from stem cell grafts or by administration of pharmacological immunosuppression. Unfortunately these approaches increase infection and disease relapse2-4. An alternative strategy is to selectively deplete alloreactive donor T cells after allostimulation by recipient antigen presenting cells (APC) before transplant. Early clinical trials of these allodepletion strategies improved immune reconstitution after HLA-mismatched HSCT without excess GvHD5, 6. However, some allodepletion techniques require specialized recipient APC production6, 7and some approaches may have off-target effects including depletion of donor pathogen-specific T cells8and CD4 T regulatory cells9.One alternative approach is the inactivation of alloreactive donor T cells via induction of alloantigen-specific hyporesponsiveness. This is achieved by stimulating donor cells with recipient APC while providing blockade of CD28-mediated co-stimulation signals10.This "alloanergization" approach reduces alloreactivity by 1-2 logs while preserving pathogen- and tumor-associated antigen T cell responses in vitro11. The strategy has been successfully employed in 2 completed and 1 ongoing clinical pilot studies in which alloanergized donor T cells were infused during or after HLA-mismatched HSCT resulting in rapid immune reconstitution, few infections and less severe acute and chronic GvHD than historical control recipients of unmanipulated HLA-mismatched transplantation12. Here we describe our current protocol for the generation of peripheral blood mononuclear cells (PBMC) which have been alloanergized to HLA-mismatched unrelated stimulator PBMC. Alloanergization is achieved by allostimulation in the presence of monoclonal antibodies to the ligands B7.1 and B7.1 to block CD28-mediated costimulation. This technique does not require the production of specialized stimulator APC and is simple to perform, requiring only a single and relatively brief ex vivo incubation step. As such, the approach can be easily standardized for clinical use to generate donor T cells with reduced alloreactivity but retaining pathogen-specific immunity for adoptive transfer in the setting of AHSCT to improve immune reconstitution without excessive GvHD.
Mitochondrial UPR-regulated innate immunity provides resistance to pathogen infection

A link between an intracellular stress response, bacterial infection and triggering of the innate immune response is shown in Caenorhabditis elegans; exposure to the pathogen Pseudomonas aeruginosa caused activation of the transcription factor ATFS-1 and innate immunity that is regulated by the mitochondrial unfolded protein response. The mitochondrial unfolded protein response (UPRmt) is a stress response that activates transcription of nuclear-encoded mitochondrial chaperone genes to promote protein homeostasis within the mitochondrion. Here Mark Pellegrino et al. provide evidence that mitochondrial dysfunction, and activation of the UPRmt, leads to upregulation of innate immunity and promotes pathogen resistance in Caenorhabditis elegans exposed to Pseudomonas aeruginosa. Metazoans identify and eliminate bacterial pathogens in microbe-rich environments such as the intestinal lumen; however, the mechanisms are unclear. Host cells could potentially use intracellular surveillance or stress response programs to detect pathogens that target monitored cellular activities and then initiate innate immune responses1,2,3. Mitochondrial function is evaluated by monitoring mitochondrial protein import efficiency of the transcription factor ATFS-1, which mediates the mitochondrial unfolded protein response (UPRmt). During mitochondrial stress, mitochondrial import is impaired4, allowing ATFS-1 to traffic to the nucleus where it mediates a transcriptional response to re-establish mitochondrial homeostasis5. Here we examined the role of ATFS-1 in Caenorhabditis elegans during pathogen exposure, because during mitochondrial stress ATFS-1 induced not only mitochondrial protective genes but also innate immune genes that included a secreted lysozyme and anti-microbial peptides. Exposure to the pathogen Pseudomonas aeruginosa caused mitochondrial dysfunction and activation of the UPRmt. C. elegans lacking atfs-1 were susceptible to P. aeruginosa, whereas hyper-activation of ATFS-1 and the UPRmt improved clearance of P. aeruginosa from the intestine and prolonged C. elegans survival in a manner mainly independent of known innate immune pathways6,7. We propose that ATFS-1 import efficiency and the UPRmt is a means to detect pathogens that target mitochondria and initiate a protective innate immune response.
Development of a zinc implant-based model for urolithiasis in goats

Abstract Urolithiasis is an important disease of small ruminants and research efforts are often directed at prevention of disease using dietary modification. Studying urolithiasis for the comparison of urolith incidence across dietary treatments is challenging due to the sporadic development of naturally-occurring disease in populations and the difficulty in detection of subclinical stone formation. Ten, 1-year old Boer-cross nonpregnant doelings were fed a calculogenic diet. Four experiments were performed utilizing zinc discs of various sizes placed within the lumen of the urinary bladder. Undetected implant loss occurred in 25–50% of animals implanted with discs greater than 13 mm. One hundred percent of retained washers accumulated calculus material. The addition of suture material to the discs increased average disc weight gain from a mean of 0.03–1.9 mg/day to 1.5–46 mg/day across experiments. Analysis of calculus obtained revealed all stone material to be primarily composed of struvite, amorphous magnesium calcium phosphate or newberyite. This model may serve as the basis for experimental studies in females to provide candidate preventative strategies that can later be validated using clinical trials in large populations of at risk males.
Long-term dynamics of CA1 hippocampal place codes

Using Ca(2+) imaging in freely behaving mice that repeatedly explored a familiar environment, we tracked thousands of CA1 pyramidal cells' place fields over weeks. Place coding was dynamic, as each day the ensemble representation of this environment involved a unique subset of cells. However, cells in the ∼15-25% overlap between any two of these subsets retained the same place fields, which sufficed to preserve an accurate spatial representation across weeks.
Trade Liberalization, Corruption, and Software Piracy

As multinational firms explore new and promising national markets two of the most crucial elements in the strategic decision regarding market-entry are the level of corruption and existing trade barriers. One form of corruption that is crucially important to firms is the theft of intellectual property. In particular, software piracy has become a hotly debated topic due to the deep costs and vast levels of piracy around the world. The purpose of this paper is to assess how laissez-faire trade policies and corruption affect national software piracy rates. Using invisible hand theory, as well as literature from the fields of international strategy and ethics, formal research hypotheses are posited and tested. Results suggest that corruption mediates the relationship between economic freedom and software piracy. Implications for multinational managers and researchers are also addressed.
Glucosphingolipids as sites of action in the chemotherapy of cancer.

Searches for abnormalities in tumors have revealed a dismayingly large number of metabolic changes, both increases and decreases in the content of qualitatively normal substances. Substances having a novel chemical structure have been found only rarely. The possibility should be considered that these apparently new compounds, despite their variety and inconsistency of appearance, are somehow responsible for the unrestrained growth, malignancy, and invasiveness characteristic of cancer. A corollary possibility should also be considered: certain admittedly normal substances found in tumors in relatively high concentrations can, if they reach a triggering concentration, begin the cancerous process. This paper presents selected clues about a class of compounds in the above categories, the glycosphingolipids based on G1cCer.S They are called “glucosphingolipids” in the title and “glycolipids” in the text.§ These substances are formed from N-acyl sphingols (ceramides) by a transferase which attaches glucose to the C-l of the sphingol. Other transferases subsequently attach additional sugar groups to the GlcCer. The most-studied glycolipids are the ones containing sialic acid, the gangliosides. Acetyl groups can be present in amide and ester linkage, and glycolyl groups can be present in amide linkage. Many researchers have come to believe that glycolipids are “closely involved” in one or more aspects of cancer cell metabolism and this article summarizes some of their reports. On the basis of literature reading and initial success with a drug that inhibits glycolipid synthesis in mouse Ehrlich ascites tumor cells, we have come to believe that glycolipids are causally involved in cancer. Our hypothesis starts with the recent discoveries that some types of cancer
Variation in Foraging Behavior Among Nesting Stages of Female Red-Faced Warblers

Foraging rates and maneuvers were examined in breeding female Red-faced Warblers (Cardellina rubrifrons) among egg-laying, incubation, and nestling stages. All measures varied among nesting stages, with prey attack rate and search speed significantly increasing from egg-laying to incubation through the nestling stage. During egg-laying and incubation, birds gleaned stationary prey from a fixed perch, but shifted to hover-sallying for stationary prey during the nestling period. These dynamic behavioral patterns may reflect responses to variable time constraints and energetic costs associated with different stages of the nesting cycle.
A Call-Routing Problem with Service-Level Constraints

We consider a queueing system, commonly found in inbound telephone call centers, that processes two types of work. Type-H jobs arrive at rate ? H , are processed at rate I»i¾µ H, and are served first come, first served within class. Aservice-level constraint of the form E[delay] = a orP {delay = I²} = limits the delay in queue that these jobs may face. An infinite backlog of type-L jobs awaits processing at rate I»L , and there is no service-level constraint on this type of work. A pool ofc identical servers processes all jobs, and a system controller must maximize the rate at which type-L jobs are processed, subject to the service-level constraint placed on the type-H work.We formulate the problem as a constrained, average-cost Markov decision process and determine the structure of effective routing policies. When the expected service times of the two classes are the same, these policies are globally optimal, and the computation time required to find the optimal policy is about that required to calculate the normalizing constant for a simpleM/M/c system. When the expected service times of the two classes differ, the policies are optimal within the class of priority policies, and the determination of optimal policy parameters can be determined through the solution of a linear program with O( c3) variables and O( c2) constraints.
A conversation analysis of self-praising in everyday Mandarin interaction

Abstract As part of a larger effort to explore how the Chinese substantiate their concept of modesty in interpersonal communication, this article reports the results of a conversation-analytic study of the self-praising behavior of the Chinese in everyday social encounters. Drawing on a corpus of approximately 35 hours of audio- and videotaped face-to-face conversations collected in Beijing and Hebei, China during 2001–2010, I examine three previously undescribed or under-described practices that are observed in my data to be used in the service of self-praising in Mandarin conversation. These practices are what I call ‘the designedly bipartite [self-praise plus modification] turn format,’ ‘disclaiming an extreme case situation,’ and ‘treating the matter ostensibly as complainable.’ In addition to their turn design, I also discuss and provide a possible account for the interactional contingencies that give rise to the use of these practices.
Endometrial cancer patients have a significant risk of harboring isolated tumor cells in histologically negative lymph nodes.

In this study, we examine the prevalence of finding isolated tumor cells (ITCs) in negative lymph nodes of endometrial cancer patients using immunohistochemistry. Seventy-six endometrial cancer patients with lymph nodes histologically negative for metastatic disease were examined. Nodal tissue sections were stained with anticytokeratin antibodies AE-1 and CAM 5.2. Nodes with single or groups of cells (two to four cells) ≤0.2 mm and showing cytokeratin reactivity were positive for ITCs. Findings were compared to features of the primary tumor and patient outcome. ITCs were present in 31 of 1712 lymph nodes. Fifteen (19.7%) patients had ITC-positive nodes. ITCs involved only pelvic nodes in nine cases, only para-aortic nodes in five cases, and pelvic and para-aortic in one case. Tumor in adnexa was the only pathologic feature associated with nodal ITCs (P = 0.0485). All 15 patients with nodal ITCs were alive at follow-up. One (6.7%) patient suffered recurrent disease but was alive at last encounter. Disease recurred in 5 (8.8%) of 57 patients without nodal ITCs. Two are alive without disease, two alive with disease, and one died from her cancer. In summary, a significant proportion of endometrial cancer patients have ITCs detected by immunohistochemistry in histologically negative regional lymph nodes.
High-temperature ethane and propane decomposition

Abstract The decomposition rates of ethane and propane in the falloff regime at high temperatures were studied in a shock tube using UV narrow-line laser absorption of CH3 at 216.6 nm. Experimental conditions ranged from 1343 to 2034 K and 0.13 to 8.4 atm with mixtures varying in concentration from 100 to 402 ppm of ethane or propane diluted in argon. Decomposition rate coefficients were determined by monitoring the formation rate of CH3 immediately behind shock waves and modeling the CH3 formation with a detailed kinetic model. Calculations were performed using RRKM/master equation analysis with a restricted (hindered) Gorin model for the transition state and fit to the current high-temperature dissociation data as well as previous low-temperature recombination measurements. The decomposition rate coefficient for ethane decomposition from 700 to 1924 K can be described, using the Troe pressure broadening formulation, by k∞, 1 (T) = 1.88 × 1050 T−9.72 exp (−54,020 K/T) s−1, k0, 1 (T) = 3.72 × 1065 T−13.14 exp (−51,120 K/T) cm3 mol−1 s−1, and Fcent, 1 (T) = 0.61 exp (−T/100 K) + 0.39 exp (−T/1900 K) + exp (−6000 K/T). The decomposition rate coefficient for propane decomposition from 600 to 1653 K can be described by k∞, 2 (T) = 1.29 × 1037T −5.84 exp (−49,010 K/T) s−1, k0, 2 (T) = 5.64 × 1074 T−15.74 exp (−49,680 K/T) cm3 mol−1 s−1, and Fcent, 2 (T) = 0.69 exp (−T/50 K) + 0.31 exp (−T/3000 K) + exp (−9000 K/T).
Spectrophotometry of Aqueous HNO 3 , H 2 SO 4 , and DClO 4 from 25° to 250°C

Dilute nitric, sulfuric, and perchloric acids are applicable as solvents for spectrophotometry up to 250°C over the following ranges: 0 to 1.0 f HNO3 from 0.6 to 1.2 μ; 0 to 0.2 f H2SO4 from 0.25 to 1.2 μ; and 0 to 1.0 f DClO4 from 0.25 to 1.8 μ. Each of these acids reacts measurably with the titanium cell wall and the sapphire windows at rates which increase with acidity and temperature. This corrosion affects the spectral measurements as a function of time and is associated with deterioration of cell window surfaces and the presence in the sample of dissolved and suspended corrosion products. These results are part of our more general program for the development of equipment and technique for routine spectrophotometry of pure liquids and solutions over a wide range of temperature and pressure.
Human apolipoprotein E peptides inhibit hepatitis C virus entry by blocking virus binding

Hepatitis C virus (HCV) entry is a multiple-step process involving a number of host factors and hence represents a promising target for new antiviral drug development. In search of novel inhibitors of HCV infection, we found that a human apolipoprotein E (apoE) peptide, hEP, containing both a receptor binding fragment and a lipid binding fragment of apoE specifically blocked the entry of cell culture grown HCV (HCVcc) at submicromolar concentrations. hEP caused little cytotoxicity in vitro and remained active even if left 24 hours in cell culture. Interestingly, hEP inhibited neither human immunodeficiency virus (HIV)-HCV pseudotypes (HCVpp) nor HIV and Dengue virus (DENV) infection. Further characterization mapped the anti-HCV activity to a 32-residue region that harbors the receptor binding domain of apoE, but this fragment must contain a cysteine residue at the N-terminus to mediate dimer formation. The anti-HCV activity of the peptide appears to be dependent on both its length and sequence and correlates with its ability to bind lipids. Finally, we demonstrated that the apoE-derived peptides directly blocked the binding of both HCVcc and patient serum-derived virus to hepatoma cells as well as primary human hepatocytes. Conclusion: apoE peptides potently inhibit HCV infection and suggest a direct role of apoE in mediating HCV entry. Our findings also highlight the potential of developing apoE mimetic peptides as novel HCV entry inhibitors by targeting HCV-host interactions. (HEPATOLOGY 2012)
Analysis of the pediatric orthopedic surgery questions on the Orthopaedic In-Training Examination, 2002 through 2006.

Background Pediatric orthopedics has been a frequently tested topic on the Orthopaedic In-Training Examination (OITE). Our goal was to provide direction for resident education efforts by: (1) analyzing the exam's number, topics, and types of pediatric orthopedic surgery questions; (2) examining references cited in the postexam answer packet supplied by the American Academy of Orthopaedic Surgeons; and (3) examining the efficacy of the Orthopaedic Knowledge Update (OKU): Pediatrics 3 book as a source for answers to the pediatric orthopedic questions. Methods We reviewed 5 years (2002 through 2006) of OITEs and the associated American Academy of Orthopaedic Surgeons' answer packets and assessed the OKU: Pediatrics 3 book for topic relativity. Each question was classified into 1 of 6 categories and labeled with a cognitive taxonomy level: 1 (simple recall), 2 (interpretation of data), or 3 (advanced problem-solving). The 6 categories included: (1) pediatric orthopedic knowledge; (2) knowledge of treatment modalities; (3) diagnosis; (4) diagnosis with recognition of associated conditions; (5) diagnosis with further studies; and (6) diagnosis with treatment. Results The overall percentage of pediatric questions was 14.1%. The most commonly addressed were pediatric elbow fractures, osteomyelitis, and scoliosis. The most common question types were categories 1 (pediatric orthopedic knowledge) and 6 (diagnosis with treatment). The most frequently referenced textbooks were Lovell and Winter's Pediatric Orthopaedics (31%) and Tachdjian's Pediatric Orthopaedics (16%). The most frequently referenced journals were the Journal of Pediatric Orthopaedics (American) (29%) and the Journal of Bone and Joint Surgery (American) (19%). Using only the OKU: Pediatrics 3 review textbook, 65% of the questions could be answered. Conclusions Knowledge of the topics more likely to be tested may help the orthopedic educator direct a didactic curriculum geared toward the OITE and American Board of Surgery examinations. Although the OKU: Pediatrics 3 book seems to be a good, concise resource for studying for the board examination and OITE, residents should be encouraged to supplement their studying with primary sources. Level of evidence Not applicable.
On Kubota's Dirichlet series

Kubota [19] showed how the theory of Eisenstein series on the higher metaplectic covers of SL2 (which he discovered) can be used to study the analytic properties of Dirichlet series formed with n-th order Gauss sums. In this paper we will prove a functional equation for such Dirichlet series in the precise form required by the companion paper [2]. Closely related results are in Eckhardt and Patterson [10]. The Kubota Dirichlet series are the entry point to a fascinating universe. Their residues, for example, are mysterious if n > 3, though there is tantalizing evidence that these residues exhibit a rich structure that can only be partially glimpsed at this time. When n = 4 the residues are the Fourier coefficients of the biquadratic theta function that were studied by Suzuki [23]. Suzuki found that he could only determine some of the coefficients. This failure to determine all the coefficients was explained in terms of the failure of uniqueness of Whittaker models for the generalized theta series by Deligne [9] and by Kazhdan and Patterson [15]. On the other hand, Patterson [22] conjectured that the mysterious coefficients are essentially square roots of Gauss sums. Evidence for Patterson’s conjecture is discussed in Bump and Hoffstein [6] and in Eckhardt and Patterson [10], where the conjecture is refined in light of numerical data. Partial proofs were given by Suzuki in [24] and [25]. Another set of conjectures relevant to the mysterious coefficients of n-th order theta functions were given by Bump and Hoffstein, who considered theta functions on the n-fold covers of GLr for arbitrary r. They are expressed as identities between Rankin-Selberg convolutions of generalized theta series and Whittaker coefficients of Eisenstein series on the metaplectic group, but they boil down to properties of the residues of Kubota Dirichlet series, and their higher rank generalizations. See Bump and Hoffstein [6], Bump [4] and Hoffstein [12]. These conjectures are different from the Patterson conjecture, and there are other considerations which suggest that there may be further unproved relations beyond those described in the conjectures of Patterson and Bump and Hoffstein.
Whole-exome sequencing of pancreatic cancer defines genetic diversity and therapeutic targets

Pancreatic ductal adenocarcinoma (PDA) has a dismal prognosis and insights into both disease etiology and targeted intervention are needed. A total of 109 micro-dissected PDA cases were subjected to whole-exome sequencing. Microdissection enriches tumour cellularity and enhances mutation calling. Here we show that environmental stress and alterations in DNA repair genes associate with distinct mutation spectra. Copy number alterations target multiple tumour suppressive/oncogenic loci; however, amplification of MYC is uniquely associated with poor outcome and adenosquamous subtype. We identify multiple novel mutated genes in PDA, with select genes harbouring prognostic significance. RBM10 mutations associate with longer survival in spite of histological features of aggressive disease. KRAS mutations are observed in >90% of cases, but codon Q61 alleles are selectively associated with improved survival. Oncogenic BRAF mutations are mutually exclusive with KRAS and define sensitivity to vemurafenib in PDA models. High-frequency alterations in Wnt signalling, chromatin remodelling, Hedgehog signalling, DNA repair and cell cycle processes are observed. Together, these data delineate new genetic diversity of PDA and provide insights into prognostic determinants and therapeutic targets.
Stability, denaturation and refolding of Mycobacterium tuberculosis MfpA, a DNA mimicking protein that confers antibiotic resistance

Abstract MfpA from Mycobacterium tuberculosis is a founding member of the pentapeptide repeat class of proteins (PRP) that is believed to confer bacterial resistance to the drug fluoroquinolone by mimicking the size, shape and surface charge of duplex DNA. We show that phenylalanine side chain stacking stabilizes the N-terminus of MfpA's pentapeptide thus extending the DNA mimicry analogy. The Lumry–Eyring model was applied to multiple spectral measures of MfpA denaturation revealing that the MfpA dimer dissociates to monomers which undergo a structural transition that leads to aggregation. MfpA retains high secondary and tertiary structure content under denaturing conditions. Dimerization stabilizes MfpA's pentapeptide repeat fold. The high Arrhenius activation energy of the barrier to aggregate formation rationalizes its stability. The mechanism of MfpA denaturation and refolding is a ‘double funnel’ energy landscape where the ‘native’ and ‘aggregate’ funnels are separated by the high barrier that is not overcome during in vitro refolding.
Thermodynamics of phospholipid bilayer assembly

Thermodynamic properties of bilayer assembly have been obtained from measurements of the solubility of the sodium salt of dimyristoylphosphatidylglycerol (DMPG) in water. The standard free energy of bilayer assembly delta G degree a is shown to be RT 1n Xs + zF psi 0 where Xs is the mole fraction of dissolved lipid, F is the Faraday constant, z is the valence of the counterion (Na+), and psi 0 is the electrical double-layer potential of the ionized bilayer. The function d 1n Xs/dT was found to be discontinuous at 24 degrees C, the gel-liquid-crystal transition temperature (Tm) for DMPG. This function was unaffected when solubilities were measured in 0.001 M NaCl solutions; thus, psi 0 is constant in the experimental temperature interval (4-40 degrees C). Using a value of psi 0 = -180 mV [Eisenberg et al. (1979) Biochemistry 18, 5213-5223], and the temperature dependence of delta G degrees a, values for delta H degrees a and delta S degree a at 24 degrees C were calculated for the gel and liquid-crystal states of DMPG. For the gel, delta H degrees a and T delta S a are -26.2 and 12.7 kcal/mol, respectively; for the liquid-crystal, delta H degrees a and T delta S degrees a are -19.2 and -5.7 kcal/mol, respectively. The calculated value for the latent heat of the gel-liquid-crystal transition is 7 kcal/mol, in agreement with calorimetric measurements.
Electronic transport in doped amorphous silicon.

The temperature dependence of the dc dark conductivity of doped hydrogenated amorphous silicon is explained by the defect-compensation model of doping with the proposal that the structure is in metastable thermal equilibrium. Observed conductivity activation energies and preexponential factors can be accounted for quantitatively. When the localized state distribution is in thermal equilibrium, the conductivity preexponential factor is the Mott minimum metallic conductivity.
Use of pseudo-concentrations to follow creeping viscous flows during transient analysis

Creeping viscous flows are followed through finite element meshes by use of pseudo-concentrations which define material position. The concentrations, assumed to be transported only by convection, serve as material markers. Illustrations are presented related to industrial forming processes and the slow deformation of geological structures.
Steering Teens Safe: A Randomized Trial of a Parent-based Intervention to Improve Safe Teen Driving

Background Crashes are the leading cause of death for teens, and parent-based interventions are a promising approach. We assess the effectiveness of Steering Teens Safe, a parent-focused program to increase safe teen driving.
Rugged Metropolis sampling with simultaneous updating of two dynamical variables.

The rugged Metropolis (RM) algorithm is a biased updating scheme which aims at directly hitting the most likely configurations in a rugged free-energy landscape. Details of the one-variable $({\mathrm{RM}}_{1})$ implementation of this algorithm are presented. This is followed by an extension to simultaneous updating of two dynamical variables $({\mathrm{RM}}_{2})$. In a test with the brain peptide Met-Enkephalin in vacuum ${\mathrm{RM}}_{2}$ improves conventional Metropolis simulations by a factor of about 4. Correlations between three or more dihedral angles appear to prevent larger improvements at low temperatures. We also investigate a multihit Metropolis scheme, which spends more CPU time on variables with large autocorrelation times.
Temporal reasoning in plan management

Summary form only. While the traditional planning problem can be viewed as a temporal reasoning problem in the abstract, most planning algorithms use specialized constrained representations that are only useful for the planning task. In the TRIPS system, we need to build complex plans, but also to reason about them in different ways in order to modify plans, consider the effects of different plans over time, monitor execution, and support natural language interpretation. We call this range of reasoning tasks plan management, and it requires a more complex temporal representation. In fact, TRIPS uses a variety of temporal representations from the Interval Temporal Logic to concrete time-indexed representations. I describe the TRIPS system, examine the different forms of temporal representations used, and describe how each is appropriate for the different reasoning tasks it supports.
A Black Technician and Blue Babies

In this paper, I discuss the many contributions of a versatile black technician, Vivien Thomas, to surgical animal research between 1930 and 1979 at Vanderbilt University and Johns Hopkins University. Thomas' experimental work led to a surgical solution for a life-threatening heart defect, called tetralogy of Fallot. Children with this condition lack sufficient oxygenation and were referred to as 'blue babies'. Following Thomas' research trajectory and his relationship with surgeon Dr Alfred Blalock, I review the conditions under which differing expectations towards race and occupation clashed, creating a status dilemma for Thomas. While the torsion originated in the laboratory where technical skills are valued, the research locale also facilitated a temporary, fragile solution for the status dilemma, because it separated Thomas from public view. Yet, Thomas' dexterity as a laboratory researcher enhanced his dilemma, because credit kept eluding him. In order to track the dynamics of race and occupational subordination as lived experience in the laboratory, I argue for an analysis of the process of crediting people for their scientific accomplishments.
Role of the NiFe Hydrogenase Hya in Oxidative Stress Defense in Geobacter sulfurreducens

Geobacter sulfurreducens, an Fe(III)-reducing deltaproteobacterium found in anoxic subsurface environments, contains 4 NiFe hydrogenases. Hyb, a periplasmically oriented membrane-bound NiFe hydrogenase, is essential for hydrogen-dependent growth. The functions of the three other hydrogenases are unknown. We show here that the other periplasmically oriented membrane-bound NiFe hydrogenase, Hya, is necessary for growth after exposure to oxidative stress when hydrogen or a highly limiting concentration of acetate is the electron source. The beneficial impact of Hya on growth was dependent on the presence of H(2) in the atmosphere. Moreover, the Hya-deficient strain was more sensitive to the presence of superoxide or hydrogen peroxide. Hya was also required to safeguard Hyb hydrogen oxidation activity after exposure to O(2). Overexpression studies demonstrated that Hya was more resistant to oxidative stress than Hyb. Overexpression of Hya also resulted in the creation of a recombinant strain better fitted for exposure to oxidative stress than wild-type G. sulfurreducens. These results demonstrate that one of the physiological roles of the O(2)-resistant Hya is to participate in the oxidative stress defense of G. sulfurreducens.
Clinical and Computed Tomographic Characteristics of Amyloid Tumor of the Lacrimal Gland

Background: Lacrimal gland masses, whose soft-tissue contour analysis, on computed tomographic (CT) scanning, shows molding to surrounding orbital structures, include inflammatory and lymphoproliferative lesions. The authors present a patient with orbital amyloidosis isolated to the lacrimal gland who also demonstrates this specific CT presentation. In addition, the literature on this rare condition is reviewed, and characterization of the typical presentation is provided. Methods: A retrospective review of the four previously reported patients and the authors' additional patient with amyloid tumor of the lacrimal gland was performed. A summary of the clinical characteristics of the disorder was formulated. Special attention was given to to the unique CT findings of the authors' patient. Results: Five patients with amyloid tumor of the lacrimal gland have been described. All patients have been women, with average age of 53 years, and who had the primary, localized variant of the disease. Neither visual impairment nor evidence of optic nerve dysfunction has developed in any of the patients. In the authors' patient, the CT softtissue contour analysis of the lacrimal gland mass demonstrated molding to adjacent orbital tissues. Conclusions: Amyloidosis of the lacrimal gland presents as a primary, localized disease process. It typically affects middle-aged women without visual morbidity. The early CT findings may mimic those seen in inflammatory or lymphoproliferative disorders of the lacrimal gland.References
Intelligent Selection of Language Model Training Data

We address the problem of selecting non-domain-specific language model training data to build auxiliary language models for use in tasks such as machine translation. Our approach is based on comparing the cross-entropy, according to domain-specific and non-domain-specifc language models, for each sentence of the text source used to produce the latter language model. We show that this produces better language models, trained on less data, than both random data selection and two other previously proposed methods.
2-D pseudo-spectral viscoacoustic modeling in a distributed-memory multi-processor computer

Abstract Two pseudo-spectral implementations of 2-D viscoacoustic modeling are developed in a distributed-memory multi-processor computing environment. The first involves simultaneous computation of the response of one model to many source locations and, as it requires no interprocessor communication, is perfectly parallel. The second involves computation of the response, to one source, of a large model that is distributed across all processors. In the latter, local rather than global, Fourier transforms are used to minimize interprocessor communication and to eliminate the need for matrix transposition. In both algorithms, absorbing boundaries are defined as zones of decreased Q as part of the model, and so require no extra computation. An empirical method of determining sets of relaxation times for a broad range of Q values eliminates the need for iterative fitting of Q -frequency curves.
A bovine herpesvirus 1 protein expressed in latently infected neurons (ORF2) promotes neurite sprouting in the presence of activated Notch1 or Notch3

Bovine herpesvirus 1 (BHV-1) infection induces clinical symptoms in the upper respiratory tract, inhibits immune responses, and can lead to life-threatening secondary bacterial infections. Following acute infection, BHV-1 establishes latency in sensory neurons within trigeminal ganglia, but stress can induce reactivation from latency. The latency-related (LR) RNA is the only viral transcript abundantly expressed in latently infected sensory neurons. An LR mutant virus with stop codons at the amino terminus of the first open reading frame (ORF) in the LR gene (ORF2) is not reactivated from latency, in part because it induces higher levels of apoptosis in infected neurons. ORF2 inhibits apoptosis in transiently transfected cells, suggesting that it plays a crucial role in the latency-reactivation cycle. ORF2 also interacts with Notch1 or Notch3 and inhibits its ability to trans activate certain viral promoters. Notch3 RNA and protein levels are increased during reactivation from latency, suggesting that Notch may promote reactivation. Activated Notch signaling interferes with neuronal differentiation, in part because neurite and axon generation is blocked. In this study, we demonstrated that ORF2 promotes neurite formation in mouse neuroblastoma cells overexpressing Notch1 or Notch3. ORF2 also interfered with Notch-mediated trans activation of the promoter that regulates the expression of Hairy Enhancer of Split 5, an inhibitor of neurite formation. Additional studies provided evidence that ORF2 promotes the degradation of Notch3, but not that of Notch1, in a proteasome-dependent manner. In summary, these studies suggest that ORF2 promotes a mature neuronal phenotype that enhances the survival of infected neurons and consequently increases the pool of latently infected neurons.
Accurate surface description from binocular stereo

The authors present a stereo vision system in which they attempt to achieve robustness with respect to scene characteristics, from textured outdoor scenes to environments composed of highly regular man-made objects. The system offers the advantages of both area-based (dense map) and feature-based (accurate disparity) processing by combining them whenever possible. The authors are able to geneate a disparity map that is sufficiently accurate to allow them to detect depth and surface orientation discontinuities, provided that the resolution is fine enough. They use an area-based cross-correlation, along with an ordering constraint and a weak surface smoothness assumption to produce an initial disparity map. Unlike other approaches, however, a match is accepted only if both views agree on a correlation peak and this peak is strong enough. This disparity map is a blurred version of the true one, however, because of the smoothing inherent in the correlation. The problem is most acute at C/sub 0/ (depth) and C/sub 1/ (crease) discontinuities but can be mitigated by introducing the edge information: the disparity map is adaptively smoothed subject to the constraint that the disparity at edges is fixed. >
Spatially heterogeneous dynamics and the Adam-Gibbs relation in the Dzugutov liquid.

We perform molecular dynamics simulations of a one-component glass-forming liquid and use the inherent structure formalism to test the predictions of the Adam−Gibbs (AG) theory and to explore the possible connection between these predictions and spatially heterogeneous dynamics. We calculate the temperature dependence of the average potential energy of the equilibrium liquid and show that it obeys the Rosenfeld−Tarazona T3/5 law for low temperature T, while the average inherent structure energy is found to be inversely proportional to temperature at low T, consistent with a Gaussian distribution of potential energy minima. We investigate the shape of the basins around the local minima in configuration space via the average basin vibrational frequency and show that the basins become slightly broader upon cooling. We evaluate the configurational entropy Sconf, a measure of the multiplicity of potential energy minima sampled by the system, and test the validity of the AG relation between Sconf and the bulk d...
Production of Anti‐W24 Xenoantisera in Rabbits1

One out of four rabbits injected with partially purified soluble HL–A antigen from serum produced cytotoxic antibodies to human lymphocytes. These antibodies appear to be directed tc the specificity W24 as determined by correlation studies with HL–A alloantisera and by absorption-inhibition experiments with human platelets and with serum soluble HL–A antigens. In the sera from the other three immunized rabbits, no antibodies to human lymphoid cells could be detected by the cytotoxic test, blocking of T cell rosette formation, stimulation of DNA synthesis and inhibition of mixed lymphocyte reaction.
Beyond bathymetry: Mapping acoustic backscattering from the deep seafloor with Sea Beam

In its standard mode of operation, the multibeam echo sounder Sea Beam produces high resolution bathymetric contour charts of the seafloor surveyed. However, additional information about the nature of the seafloor can be extracted from the structure of the echo signals received by the system. Such signals have been recorded digitally over a variety of seafloor environments for which independent observations from bottom photographs or sidescan sonars were available. An attempt is made to relate the statistical properties of the bottom‐backscattered sound field to the independently observed geological characteristics of the seafloor surveyed. Acoustic boundary mapping over flat areas is achieved by following trend changes in the acoustic data both along and across track. Such changes in the acoustics are found to correlate with changes in bottom type or roughness structure. The overall energy level of a partial angular‐dependence function of backscattering appears to depend strongly on bottom type, whereas ...
Correlation studies using the equivalent base horizontal acceleration method

The equivalent base horizontal acceleration concept was developed for calculating the response of test structures to shaking table excitations, to account for pitching interaction effects of the table. Using the procedure, analysis-experiment comparisons were made of the shaking table tests of a 0–3-scale model of a six-storey concentrically K-braced steel structure. The correlation of the analytical and experimental results was excellent in both the elastic and inelastic ranges of structural response.
Structure and Properties of Tetracyanomanganate(II), [MnII(CN)4]2−, The First Paramagnetic Tetrahedral Cyanometalate Complex

A place in the sun for solutions of [(Ph3 P)2 N]2 [Mn(CN)6 ] provides-by photochemical degradation-[MnII (CN)4 ]2- ions, the only homoleptic cyanide complex ion that is high spin (structure depicted on the right). Magnetic measurements indicate a high-spin 6 A1 ground state (S=5/2), and the cyanide ligands are virtually entirely σ donors, without significant binding contributions from d-π* back-bonding.
Structure of the antiviral assembly inhibitor CAP-1 complex with the HIV-1 CA protein.

antiviral assembly inhibitor N-(3-chloro-4-methylphenyl)-N′-{2-[({5[(dimethylamino)-methyl]-2-furyl}-methyl)-sulfanyl]ethyl}-urea) (CAP-1) using a combination of NMR spectroscopy and X-ray crystallography. The protein undergoes a remarkable conformational change upon CAP-1 binding, in which Phe32 is displaced from its buried position in the protein core to open a deep hydrophobic cavity that serves as the ligand binding site. The aromatic ring of CAP-1 inserts into the cavity, with the urea NH groups forming hydrogen bonds with the backbone oxygen of Val59 and the dimethylamonium group interacting with the side-chains of Glu28 and Glu29. Elements that could be exploited to improve binding affinity are apparent in the structure. The displacement of Phe32 by CAP-1 appears to be facilitated by a strained main-chain conformation, which suggests a potential role for a Phe32 conformational switch during normal capsid assembly.
Hippocrates, Galen, and the uses of trepanation in the ancient classical world.

ατρησιζ) is the process by which a hole is drilled into the skull, exposing the intracranial contents for either medical or mystical purposes. It represents one of the oldest surgical procedures, and its practice was widespread in many ancient cultures and several parts of the world. Trepanation was used in ancient Greece and Rome, as described in several ancient texts. Hippocrates and Galen are two of the most prominent ancient Greek medical writers, and their works have influenced the evolution of medicine and neurosurgery across the centuries. The purpose of this paper is to examine Hippocrates’ and Galen’s written accounts of the technique and use of trepanation in the ancient Greek and Roman world. Examination of those records reveals the ancient knowledge of neurological anatomy, physiology, and therapeutics, and illustrates the state and evolution of neurosurgery in the classical world. (DOI: 10.3171/FOC-07/07/E11)