cssi/SciSciGPT-SciSciNet huggingface dataset:
New high pH crystal forms of ribonucleases A and S.

Bovine pancreatic ribonuclease A has been crystallized at pH 9 from (NH 4 ) 2 SO 4 /CsCl. The crystals (designated form M) belong to the trigonal space group P 3 1 21 and have unit cell dimensions a =64·34 A, c =65·00 A, ψ=120°. They are isomorphous with crystal form W of bovine pancreatic ribonuclease S, which is grown at pH 6·6. Ribonuclease S has also been crystallized at pH 9 and is isomorphous with forms M and W. Significant intensity differences exist among the crystal forms, suggesting pH-induced conformational changes at least as large as those caused by limited proteolysis. The crystals of form M diffract well to at least 2·8 A resolution.
Application of High-Pressure Liquid Chromatography and Thermal Energy Analyzer to Analysis of Trinitroglycerin and Its Metabolites in Blood

A highly selective and sensitive analytical procedure for the determination of trinitroglycerin and four metabolites in whole blood was developed. Trinitroglycerin and its metabolites were extracted from whole blood with ethyl acetate and analyzed by high-pressure liquid chromatography using the thermal energy analyzer detector. Linearity of response was observed over the 1–1000-ng range. The applicability of this method to the analysis of whole blood from dogs orally dosed with trinitroglycerin is described.
Framing biosecurity: An alternative to the biotech revolution model?

Since 11 September 2001 there is growing national and international policy focus on the increasing threat of bioterrorism. Underpinning this policy focus is a dominant frame of discourse for how to consider biosecurity threats. This paper describes some of the key ideas comprising the dominant biosecurity discourse and contrasts it with an alternative framing of the issues. To illustrate these different frames, it draws on examples from the emerging field of synthetic genomes and other biotechnologies that have generated security concerns. It argues that the current dominant frame takes away attention from other important considerations for assessing the threat from biotechnologies. Copyright , Beech Tree Publishing.
The discriminative stimulus effects of neuropeptide Y.

Abstract Neuropeptide Y (NPY), an endogenous peptide which strongly induces food intake, is demonstrated to have discriminative stimulus properties when administered intracerebroventricularly. Rats rapidly learned to press the appropriate level during training. NPY discrimination was dose-dependent. NPY's discriminative stimulus properties were compared to those of two doses of Peptide YY (PYY) and 24 and 48 h of food deprivation, conditions which also increase feeding. Both doses of PYY generalized to NPY, supporting previous findings that PYY has effects similar to NPY. Although food deprivation increases feeding in a manner similar to NPY, food deprivation did not result in NPY-appropriate responding.
Extrema of SU ( n ) Higgs potentials and symmetry-breaking pattern

It is shown that the most general renormalizable Higgs potential for the adjoint representation $\ensuremath{\varphi}$ of $\mathrm{SU}(n)$ has extrema only if at most two eigenvalues of $\ensuremath{\varphi}$ are different. This result is used to find the symmetry-breaking pattern due to scalar fields in the adjoint and fundamental representations of $\mathrm{SU}(n)$.
Robust PN code acquisition with antenna arrays in asynchronous DS-CDMA systems

The problem of PN code acquisition at base stations in asynchronous direct-sequence code-division multiple access (DS-CDMA) systems equipped with antenna arrays is investigated in this work. Both the fading and the near-far interference effects of the communication channel are considered. The antenna system in the base station is a one-dimensional (1D) linear beamforming array. After formulating the acquisition problem, we propose several methods for its solution. They include: the least squares method, the constrained optimization method, the weighted eigenvectors method and the generalized likelihood ratio test method. The system parameters such as the fading gain, the direction of arrival (DOA) and transmitted data symbols from each active mobile user are assumed to be unknown but deterministic in our model. The only knowledge is the spreading code of the desired user. It is demonstrated by simulation results that our proposed solutions are resistant to the near-far effect and robust to the change of the fading environment.
CHROMOSOMAL ANALYSES AND THE ORIGIN OF ALLOPOLYPLOID POLYPODIUM VIRGINIANUM (POLYPODIACEAE)

Polypodium virginianum L. has been treated as a morphologically and chromosomally variable species. Recently, however, two species have been named from within the P. virginianum complex. Chromosome counts reported here confirmed that these segregate species, P. appalachianum Haufler and Windham and P. sibiricum Siplivinskij, are diploids with n = 37. It was further hypothesized that hybridization between these diploids initiated the allotetraploid P. virginianum. Naturally occurring, sterile triploid plants obtained from habitats in which the putative allotetraploid was sympatric with its presumed diploid progenitors have been verified isozymically as backcross hybrids. Meiotic chromosomal behavior showed that the triploids contained univalents and bivalents in nearly equal numbers, confirming that tetraploid P. virginianum contained one genome from each diploid. Observation of three to six trivalents in triploid preparations suggested that the diploids are still closely related genetically. This hypothesis was supported by isozymic studies which found a genetic identity of 0.610 between P. appalachianum and P. sibiricum, a value much higher than the average identity for congeneric fem species studied to date (0.33) and higher than any other species pair in the P. vulgare L. complex (average I = 0.307). These chromosomal and isozymic data help to resolve a biosystematic riddle that has interested pteridologists for over 40 years.
Man as timekeeper.

Today I am persuaded, more than ever, that a whole series of psychopathological manifestations can be understood and examined more thoroughly from the vantage of the phenomenon of time⋯ .1,p.8
Diacetylene–siloxane–carborane thermosets and ceramic precursors

Thermosets and ceramic chars were prepared and characterized from a diacetylene–siloxane–carborane polymer, DSCS, and a diacetylene–siloxane polymer, DS. The goal was to incorporate the known thermo-oxidative stability found in the siloxane–carborane elastomers into high-performance thermosets and ceramic chars. The DSCS thermoset had excellent thermo-oxidative stability as determined by a low weight loss and tough residue after annealing for 100 h in air at 300 °C, but it had a low glass transition temperature (94 °C). The DS thermoset did not undergo a glass transition below 350 °C and had a low weight loss on thermo-oxidative aging, but the residue was quite brittle. Two random copolymers were made to optimize the thermo-oxidative stability and toughness of the DSCS thermoset and the higher glass transition of the DS thermoset. Significantly, the 50:50 DSCS/DS random copolymer when cured to a thermoset did not undergo a glass transition below 350 °C, yet retained much of the strength, toughness and thermo-oxidative stability of the DSCS thermoset. Heat treatment of the poly-DSCS to elevated temperatures resulted in a ceramic material with improved properties relative to the ceramic derived from poly-DS. Both polymers had similar char yields to 800 °C, but the poly-DSCS solidified to a 15% denser ceramic. Copyright © 2000 John Wiley & Sons, Ltd.
Ritornare a Tilgher: Bergsonian Themes and the Human Condition in the Notebooks of Serafino Gubbio, Cinematograph Operator

Since its apearance in 1922, Adriano Tilgher's critical assessment of Luigi Pirandello has been evaluated in a negative light, especially its categories of vita and forma, — which Tilgher borrowed from Pirandello himself, specifically from the short storyLa carriola — considered as nothing more than abstract philosophizing and ultimately held responsible for the drying up of Pirandello' inspirations. Vita and forma were generically reduced by the vast majority of Italian critics, especially those valuing Croce's idea of art as lyrical intuition, to the camouflaging Pirandello's characters were forced to adopt to fit into the social fabric, thereby losing their metaphysical charge. In fact, when properly interpreted in the light of Henri Bergson's vitalist philosophy, vita and forma prove to be key concepts in the restoration of Pirandello to the canon of the European avant-garde. After a survey of some of the comments made by Italian scholars on the role of Adriano Tilgher's criticism, the article attempt...
Selection bias in rheumatic disease research

The validity of research into risk factors for the development of rheumatic conditions and their sequelae can be threatened by selection bias. In this Review, the authors outline potentially major selection bias issues in rheumatic disease research and suggest approaches which could be used to help limit the impact of these biases on future research. The identification of modifiable risk factors for the development of rheumatic conditions and their sequelae is crucial for reducing the substantial worldwide burden of these diseases. However, the validity of such research can be threatened by sources of bias, including confounding, measurement and selection biases. In this Review, we discuss potentially major issues of selection bias—a type of bias frequently overshadowed by other bias and feasibility issues, despite being equally or more problematic—in key areas of rheumatic disease research. We present index event bias (a type of selection bias) as one of the potentially unifying reasons behind some unexpected findings, such as the 'risk factor paradox'—a phenomenon exemplified by the discrepant effects of certain risk factors on the development versus the progression of osteoarthritis (OA) or rheumatoid arthritis (RA). We also discuss potential selection biases owing to differential loss to follow-up in RA and OA research, as well as those due to the depletion of susceptibles (prevalent user bias) and immortal time bias. The lesson remains that selection bias can be ubiquitous and, therefore, has the potential to lead the field astray. Thus, we conclude with suggestions to help investigators avoid such issues and limit the impact on future rheumatology research.
Sunlight induced progression of AIDS

Ultraviolet B (UVB) radiation in sunlight damages the cutaneous immune system of individuals primarily by converting trans-urocanic acid (UCA) to its cis isoform which in turn instigates excessive local, and eventually systemic, levels of tumor necrosis factor-alpha (TNF alpha). UVB radiation and TNF alpha have been found to activate HIV from the latent state, and TNF alpha has been implicated in the pathogenesis of several manifestations of the acquired immune deficiency syndrome (AIDS). We hypothesize that the immunosuppressant properties of TNF alpha and cis-UCA, released by intense sun exposure, can accelerate the onset and progression of AIDS in HIV-infected individuals.
Declining financial capacity in mild cognitive impairment: A 1-year longitudinal study

Objective: To investigate 1-year change in financial capacity in relation to conversion from amnestic mild cognitive impairment (MCI) to dementia. Methods: Seventy-six cognitively healthy older controls, 25 patients with amnestic MCI who converted to Alzheimer-type dementia during the study period (MCI converters), and 62 patients with MCI who did not convert to dementia (MCI nonconverters) were administered the Financial Capacity Instrument (FCI) at baseline and 1-year follow-up. Performance on the FCI domain and global scores was compared within and between groups using multivariate repeated-measures analyses. Results: At baseline, controls performed better than MCI converters and nonconverters on almost all FCI domains and on both FCI total scores. MCI converters performed below nonconverters on domains of financial concepts, cash transactions, bank statement management, and bill payment and on both FCI total scores. At 1-year follow-up, MCI converters showed significantly greater decline than controls and MCI nonconverters for the domain of checkbook management and for both FCI total scores. The domain of bank statement management showed a strong trend. For both the checkbook and bank statement domains, MCI converters showed declines in procedural skills, such as calculating the correct balance in a checkbook register, but not in conceptual understanding of a checkbook or a bank statement. Conclusions: Declining financial skills are detectable in patients with mild cognitive impairment (MCI) in the year before their conversion to Alzheimer disease. Clinicians should proactively monitor patients with MCI for declining financial skills and advise patients and families about appropriate interventions.
The matrix and beyond: expanding proactive resources for customers

At Oregon Health & Science University (OHSU), essential duties of the Information Technology Group (ITG) include providing support for a diverse customer base. Faculty, staff, students, volunteers, visiting scholars, interns, vendors, and community healthcare partners all rely on ITG's Customer Relations Management Division (CRMD) for resolving their computing and account access issues. In a dynamic support environment where many of the customer roles falls outside the one-size-fits-all support approach, CRMD expanded their approach to accommodate their diverse clients.CRMD's Computer Access group introduced role-based matrices on their electronic account request forms to help simplify the challenges of granting appropriate network accesses. The revamped forms reduced follow-up contacts from customers. CRMD's HelpDesk launched an online Self-Service Portal for providing customers with one-stop shopping for their diverse computing needs. Content provided on the portal includes self-service password changes, tree-based knowledge base articles organized by applications, quick reference guides for role-based password requirements and core applications, password and access matrix for nearly 40 applications, and computing tips of the week. The portal provides a convenient around-the-clock alternative for customers who wish to resolve their computing issues immediately without having to contact the HelpDesk directly.By implementing proactive forms and resources, ITG has taken steps to address the ever-expanding needs of their diverse customer base. These changes increase the level of self-sufficiency for customers, reduce the staff's customer contact time for routine issues, and provide the ITG a chance to learn the needs of their constituents.
Computed Tomography of Posterior Uveal Melanomas

• Computed tomographic (CT) scans were obtained from 48 patients with posterior uveal melanoma. The CT measurements of maximal and minimal basal diameters and thickness of each tumor were compared with the assessments of these tumor dimensions obtained by ophthalmoscopic estimation (basal diameters only) and standardized A-scan ultrasonography (thickness only) and with the gross pathologic measurements of these tumors. The correlation between measurements of tumor thickness by CT scanning, standardized A-scan ultrasonography, and gross pathologic analysis was substantially better than that between the CT, ophthalmoscopic, and gross pathologic measurements of tumor basal diameters. Computed tomographic scanning appears to be a good method for determining the in vivo size of choroidal and ciliary body melanomas.
Lead-isotope inhomogeneity in Precambrian igneous K-feldspars

Stepwise Pb-removal experiments, using both vacuum volatilization and HF-leaching techniques, on acid-washed K-feldspar concentrates from Precambrian igneous rocks show that all contain some unsupported radiogenic Pb. Two types of radiogenic Pb were recognized. One has a “normal” isotopic composition, with relative abundances of ^(206)Pb, ^(207)Pb and ^(208)Pb consistent with the age and U-Th contents of the rocks. The other type of unsupported radiogenic lead in the feldspars is apparently pure ^(206)Pb, derived from long-term migration and accumulation of radioactive daughter(s) of ^(238)U. This “pure ^(206)pb” lead occupies different sites from the “normal” radiogenic lead, and tends to show a release maximum during vacuum volatilization at about 1150°C. The usefulness of stepwise vacuum volatilization may be limited by the tendency of a small amount of radiogenic lead to concentrate in the least volatile fraction. Stepwise partial HF attacks appear to give at least as good separation of radiogenic from original feldspar lead, and are recommended as a routine procedure for isotopic analyses of Precambrian feldspars. The fact that most of the five K-feldspars examined contained unsupported radiogenic lead implies that caution must be used in applying total-sample lead analyses of Precambrian feldspars to problems of lead-isotope evolution in crustal rocks.
An inexpensive wideband high gain, physiological amplifier

Abstract A wideband, high gain, general purpose amplifier for physiological use is described. It provides excellent performance for very low cost and has sufficient output capability to drive data processing equipment directly, eliminating the need for additional amplification.
Studies with spike initiators: linearization by noise allows continuous signal modulation in neural networks

It is shown that noise can be an important element in the translation of neuronal generator potentials (summed inputs) to neuronal spike trains (outputs), creating or expanding a range of amplitudes over which the spike rate is proportional to the generator potential amplitude. Noise converts the basically nonlinear operation of a spoke initiator into a nearly linear modulation process. This linearization effect of noise is examined in a simple intuitive model of a static threshold and in a more realistic computer simulation of spike initiator based on the Hodgkin-Huxley (HH) model. The results are qualitatively similar; in each case larger noise amplitude results in a larger range of nearly linear modulation. The computer simulation of the HH model with noise shows linear and nonlinear features that were earlier observed in spike data obtained from the VIIIth nerve of the bullfrog. This suggests that these features can be explained in terms of spike initiator properties, and it also suggests that the HH model may be useful for representing basic spike initiator properties in vertebrates. >
Biopsy indication--a predictor of pathologic stage among men with preoperative serum PSA levels of 4.0 ng/mL or less and T1c disease

Abstract Objectives To determine the indications for biopsy among men with a prostate-specific antigen (PSA) level of 4 ng/mL or less and T1c disease and whether the reason for biopsy correlated with the final pathologic stage. It is not uncommon for men to undergo radical prostatectomy (RP) with a prostate-specific antigen (PSA) level of 4 ng/mL or less and T1c disease. Methods We examined the percentage of men with T1c disease and PSA level of 4.0 ng/mL or less undergoing RP over time. We identified 874 men with T1c prostate adenocarcinoma and PSA levels of 4 ng/mL or less who were treated with RP between 1994 and 2003. We excluded 72 patients who had received preoperative hormonal therapy and 86 patients for whom the reason for biopsy was unclear. The pathologic outcomes were compared between the various biopsy indication groups using analysis of variance. Results The percentage of men with T1c disease and a PSA level of 4.0 ng/mL or less has steadily increased from 0% before 1990 to 19% in 2003. Among men treated between 1994 and 2003, the most common indication for biopsy was a spike in the PSA level to greater than their reference level before biopsy (n = 471, 66%), although in all patients, the PSA level returned to 4 ng/mL or less before surgery. In 163 patients (35%), the PSA level remained elevated above the reference range and in the remaining 308 patients (65%), the PSA declined to a value below the reference range before surgery. The second most common indication for biopsy was an abnormal digital rectal examination by the referring/primary physician that, when repeated by the attending surgeon, was believed to be normal (n = 155, 22%). Abnormal PSA velocity accounted for biopsy in 68 patients (10%). Among patients with the three most common indications for biopsy, no statistically significant differences in the pathologic tumor characteristics between the groups were noted on the basis of the biopsy indication. Conclusions One in five men undergoing RP at our institution today has T1c disease and a PSA value of 4.0 ng/mL or less. The most common indication for biopsy was an elevated PSA level above their reference range, although in most, the PSA had returned to a normal value before surgery. Regardless of the indication for biopsy, these men had favorable findings at RP. That 22% of patients underwent biopsy because of what was perceived to be an abnormal digital rectal examination underscores the need to continue to perform digital rectal examination along with PSA determination as a part of routine prostate cancer screening.
Role of histone pairs H2A,H2B and H3,H4 in the self-assembly of nucleosome core particles.

Abstract The role of the histone pairs H2A,H2B and H3,H4 in the kinetics of core particle formation was investigated by using N -(1-pyrene)maleimide-labeled histone H3. The excimer emission intensity of a DNA-core histone complex prepared by direct mixing of DNA and histones in 0.2 m -NaCl is reduced by half when H2A,H2B is omitted. Fluorescence quenching studies and lifetime measurements indicate that the emission differences are probably due to static quenching. In a correctly folded nucleosome or a DNA-(H3,H4) complex, the two pyrene rings are buried and are held very close. DNA-(H3,H4) can interact with additional copies of H3,H4, but only when two dimers of H2A,H2B are correctly bound is there a specific twofold increase in excimer emission. The kinetics of the reaction of H3,H4 with DNA in 0.2 m -NaCl were followed by measuring the increase in 460 nm fluorescence. The apparent rate constant of the dominant kinetic component is ~ 2 × 10 −1 s −1 . If histones H2A,H2B are added immediately after the preparation of the DNA-(H3,H4) complex, an increase in excimer fluorescence is observed, with an apparent rate constant of ~ 6 × 10 −3 s −1 . However, if histones H2A,H2B are added one hour after DNA-(H3,H4) complex formation, there is no increase in excimer fluorescence. These results suggest that an intermediate involving the H3,H4 tetramer is formed first in nucleosome assembly. In the presence of H2A,H2B, this intermediate evolves to the final folded nucleosome, but in the absence of H2A,H2B it rearranges to an unmaturable dead-end complex. Additional experiments show that a very fast transfer of histone pairs (probably H2A,H2B) can take place between partially reconstituted nucleosomes.
SU‐F‐BRD‐05: Dosimetric Comparison of Protocol‐Based SBRT Lung Treatment Modalities: Statistically Significant VMAT Advantages Over Fixed‐ Beam IMRT

Purpose: The purpose of this study is to inter-compare and find statistically significant differences between flattened field fixed-beam (FB) IMRT with flattening-filter free (FFF) volumetric modulated arc therapy (VMAT) for stereotactic body radiation therapy SBRT. Methods: SBRT plans using FB IMRT and FFF VMAT were generated for fifteen SBRT lung patients using 6 MV beams. For each patient, both IMRT and VMAT plans were created for comparison. Plans were generated utilizing RTOG 0915 (peripheral, 10 patients) and RTOG 0813 (medial, 5 patients) lung protocols. Target dose, critical structure dose, and treatment time were compared and tested for statistical significance. Parameters of interest included prescription isodose surface coverage, target dose heterogeneity, high dose spillage (location and volume), low dose spillage (location and volume), lung dose spillage, and critical structure maximum- and volumetric-dose limits. Results: For all criteria, we found equivalent or higher conformality with VMAT plans as well as reduced critical structure doses. Several differences passed a Student's t-test of significance: VMAT reduced the high dose spillage, evaluated with conformality index (CI), by an average of 9.4%±15.1% (p=0.030) compared to IMRT. VMAT plans reduced the lung volume receiving 20 Gy by 16.2%±15.0% (p=0.016) compared with IMRT. For the RTOG 0915 peripheral lesions, the volumes of lung receiving 12.4 Gy and 11.6 Gy were reduced by 27.0%±13.8% and 27.5%±12.6% (for both, p<0.001) in VMAT plans. Of the 26 protocol pass/fail criteria, VMAT plans were able to achieve an average of 0.2±0.7 (p=0.026) more constraints than the IMRT plans. Conclusions: FFF VMAT has dosimetric advantages over fixed beam IMRT for lung SBRT. Significant advantages included increased dose conformity, and reduced organs-at-risk doses. The overall improvements in terms of protocol pass/fail criteria were more modest and will require more patient data to establish difference trends of more statistical significance.
The changing contexts of gender: Between fixed and fluid experience

Each of us holds unconscious representations of man and woman. Traditional psychoanalytic theories have viewed gender as formed primarily through unconscious representations of either man or woman. These theories have linked gender identifications to the resolution of either oedipal or preoedipal developmental issues. With this resolution, gender identifications have been conceptualized as acquiring a cohesiveness and a fixed nature over the rest of the life span. Contemporary feminist theories have challenged these ideas of fixed, unitary identifications and have offered instead the notion of a fluid gender that moves between multiple identifications. What is problematic is that either the understanding of gender has been restricted to the idea of singular, fixed identifications because of the linear frame of traditional theories or, in the feminist psychoanalytic quest for multiplicity and fluidity, no place has been left for the more fixed quality of gender experience. The tension between gender rigidi...
Vulnerability scoring for security configuration settings

The best-known vulnerability scoring standard, the Common Vulnerability Scoring System (CVSS), is designed to quantify the severity of security-related software flaw vulnerabilities. This paper describes our efforts to determine if CVSS could be adapted for use with a different type of vulnerability: security configuration settings. We have identified significant differences in scoring configuration settings and software flaws and have proposed methods for accommodating those differences. We also generated scores for 187 configuration settings to evaluate the new specification.
Uncertainty, Value, Communication, and Problematic Integration

This essay discusses problematic integration (PI) theory, a general perspective on the nature of the dynamic relationship between communication and tensions among expectations and desires and considers the relevance and potential value of PI theory to questions foundational to the field of communication research. The paper begins with a discussion of the main propositions of PI theory, then considers the relationship between the theory and emerging analyses of uncertainty, attending in particular to the meanings of uncertainty and the tensions among uncertainties, wants, and wishes.
Nonlinear screening and effective electrostatic interactions in charge-stabilized colloidal suspensions

A nonlinear response theory is developed and applied to electrostatic interactions between spherical macroions, screened by surrounding microions, in charge-stabilized colloidal suspensions. The theory describes leading-order nonlinear response of the microions (counterions, salt ions) to the electrostatic potential of the macroions and predicts microion-induced effective many-body interactions between macroions. A linear response approximation [A.R. Denton, Phys. Rev. E 62, 3855 (2000)] yields an effective pair potential of screened-Coulomb (Yukawa) form, as well as a one-body volume energy, which contributes to the free energy. Nonlinear response generates effective many-body interactions and essential corrections to both the effective pair potential and the volume energy. By adopting a random-phase approximation (RPA) for the response functions, and thus neglecting microion correlations, practical expressions are derived for the effective pair and triplet potentials and for the volume energy. Nonlinear screening is found to weaken repulsive pair interactions, induce attractive triplet interactions, and modify the volume energy. Numerical results for monovalent microions are in good agreement with available ab initio simulation data and demonstrate that nonlinear effects grow with increasing macroion charge and concentration and with decreasing salt concentration. In the dilute limit of zero macroion concentration, leading-order nonlinear corrections vanish. Finally, it is shown that nonlinear response theory, when combined with the RPA, is formally equivalent to the mean-field Poisson-Boltzmann theory and that the linear response approximation corresponds, within integral-equation theory, to a linearized hypernetted-chain closure.
Ammonium uptake in rhodopseudomonas capsulata

Investigations of the uptake of ammonium (NH 4 + ) by Rhodopseudomonas capsulata B100 supported the presence of an NH 4 + transport system. Experimentally NH 4 + was determined by electrode or indophenol assay and saturation kinetics were observed with two apparent K m's of 1.7 μM and 11.1 μM (pH 6.8, 30°) and a V max at saturation of 50–60 nmol/min·mg protein. The optimum pH and temperature were 7.0 and 33° C, respectively. The Q10 quotient was calculated to be 1.9 at 100 μM NH 4 + , indicating enzymatic involvement. In contrast to the wild type, B100, excretion of NH 4 + , not uptake, was observed in a glutamine auxotroph, R. capsulata G29, which is derepressed for nitrogenase and lacks glutamine synthetase activity. G29R1, a revertant of G29, also took up NH 4 + at the same rate as wild type and had fully restored glutamine synthetase activity. Partially restored derivatives, G29R5 and G29R6, grew more slowly than wild type on NH 4 + as the nitrogen source, remained derepressed for nitrogenase in the presence of NH 4 + , and displayed rates of NH 4 + uptake in proportion to their glutamine synthetase activity. Ammonium uptake and glutamine synthetase activity were also restored in R. capsulata G29 exconjugants which had received the plasmid pPS25, containing the R. capsulata glutamine synthetase structural gene. These data suggest that NH 4 + transport is tightly coupled to assimilation.
Teaching Target-Oriented and Diversity-Oriented Organic Synthesis at Harvard University

Diversity-oriented synthesis presents many formidable challenges to the practitioners of synthetic organic chemistry. Those challenges include the effective teaching of this new and evolving discipline to ensure that students are well positioned to begin exploring its full potential. Fortunately, the teaching of synthetic organic chemistry has a rich history in the context of target-oriented synthesis, and this precedent can serve as a strong foundation for meeting the challenges of teaching diversity-oriented synthesis.
Heparin-induced antibodies and cardiovascular risk in patients on dialysis

The clinical relevance of heparin-induced antibodies (HIA) in the absence of thrombocytopenia remains to be defined. The aims of this study were (i) to determine the prevalence of HIA in patients treated by dialysis, (ii) to determine the prevalence of thrombocytopenia and heparin-induced thrombocytopenia (HIT), and (iii) to test whether HIA are associated with adverse outcomes. Sera from 740 patients treated by hemodialysis (HD, n=596) and peritoneal dialysis (PD, n=144) were tested for HIA (IgG, IgA or IgM) by masked investigators at approximately six months after enrolment in the Choices for Healthy Outcomes in Caring for End-Stage Renal Disease (CHOICE) study. We assessed, with time-to-event Cox proportional hazards models, whether the presence of HIA predicted any of four clinical outcomes: arterial cardiovascular events, venous thromboembolism, vascular access occlusion and mortality. HIA prevalence was 10.3% overall. HIA positivity did not predict development of thrombocytopenia or any of the four clinical outcomes over a mean follow-up of 3.6 years, with hazard ratios for arterial cardiovascular events of 0.98 (95% confidence interval 0.70-1.37), venous thromboembolism 1.39 (0.17-11.5), vascular access occlusion 0.82 (0.40-1.71), and mortality 1.18 (0.85-1.64). Chronic intermittent heparin exposure was associated with a high seroprevalence of HIA. In dialysis patients these antibodies were not an independent risk factor for cardiovascular events and mortality. Our data do not suggest that dialysis patients should be monitored for HIA antibodies in the absence of thrombocytopenia.
Effects of sex hormones on phospholipid, RNA, and protein metabolism in the arterial intima

Summary The effects of sex hormones on the arterial metabolism of phospholipid, RNA, and protein have been examined in human, canine, and rat blood vessels. Isolated arterial segments were incubated with 32 P, [ 14 C]acetate, and [ 14 C]leucine and the incorporation of the precursors into lipid, RNA, and protein were measured. The influence of the sex hormones on these parameters was also studied in vivo in the sexually immature rat. Estrone sulfate and estradiol increased the arterial incorporation of 32 P into phospholipid in vitro in all 3 species. Testosterone and puromycin inhibited the in vitro stimulation of incorporation of 32 P into phospholipid induced by estrogens although in vivo in the rat, testosterone enhanced rather than inhibited the incorporation of 32 P into phospholipid. Estrogens did not appear to influence the in vitro incorporation of [ 14 C] acetate into lipids other than phospholipids. In the sexually immature rat, estradiol appeared to increase the aortic incorporation in vivo of 32 P and [ 14 C]glycine into RNA and of [ 14 C]glycine into protein although in vitro , no influence of estradiol or estrone sulfate on these parameters could be demonstrated.
Regulation of p70 S6 Kinase by Complex Formation between the Rac Guanine Nucleotide Exchange Factor (Rac-GEF) Tiam1 and the Scaffold Spinophilin

Tiam1 is a ubiquitous guanine nucleotide exchange factor (GEF) that activates the Rac GTPase. We have shown previously that the N terminus of Tiam1 contributes to the signaling specificity of its downstream target Rac via association with IB2, a scaffold that promotes Rac activation of a p38 kinase cascade. Here we show that the N terminus of Tiam1 can influence Rac signaling specificity in a different way by interaction with spinophilin, a scaffold that binds to p70 S6 kinase, another protein regulated by Rac. In particular, spinophilin binding promotes the plasma membrane localization of Tiam1 and enhances the ability of Tiam1 to activate p70 S6 kinase. In contrast, spinophilin binding suppresses the ability of Tiam to activate Pak1, a different Rac effector. Finally, a mutant spinophilin that cannot bind to Tiam1 suppresses serum-induced p70 S6 kinase activation in cells, suggesting that a Tiam1/spinophilin complex contributes to p70 S6 kinase regulation by extracellular signals. These findings add to a growing body of evidence supporting the concept that some Rac-GEFs not only activate Rac GTPases but also participate in the selection of Rac effector by binding to particular scaffolds that complex with components of specific Rac effector pathways.
Thoracic Trauma in Horses

Thoracic trauma represents an important cause of morbidity in mortality after injury in human beings and animals. After any form of suspected chest wall trauma, initial emergency management should include assurance of a patent airway and adequate ventilation, along with treatment for shock if present. As with any open wound, tetanus prophylaxis should be instituted. Types of trauma to the thoracic region of the horse include pectoral and axillary lacerations, penetrating chest wounds, flail chest, fractures of the ribs, blunt thoracic trauma, and several potential sequelae that include pneumothorax, pneumomediastinum, hemothorax, pleuritis, fistulae of the sternum or ribs, and diaphragmatic hernia. Emergency management of these various forms of thoracic trauma is discussed.
Alteration in the regulation of neuronal muscarinic acetylcholine receptor number induced by chronic lithium in neuroblastoma cells.

Because previous studies in whole-animal models have reported inconsistent results regarding the effect of chronic lithium on the regulation of the neuronal muscarinic acetylcholine receptor (mAChR) number, we examined the effect of chronic lithium on the regulation of mAChR in cell cultures of N1E-115, a mouse neuroblastoma clone, Li+ induced a concentration- and time-dependent increase in the mAChR number, with a 30% increase in specific [3H]quinuclidinyl binding in membrane homogenates induced by a 5-day incubation with 10 mM Li+. Agonist-induced down-regulation of the mAChR number was also inhibited by lithium: chronic treatment with 10 mM Li+ caused a 25–35% reduction in the magnitude of carbachol. In contrast, the decrease in the mAChR number induced by the synergistic action of A23187 (300 nM) and phorbol myristate acetate (300 nM) was unaffected by Li+. These results demonstrate that chronic treatment with Li+ increases the basal mAChR number and dampens the decrease in receptor number induced by a muscarinic agonist in neuroblastoma cells. The implications of these results in understanding the functional regulation of neuronal mAChR number are discussed.
ethnicity and commerce

The widely observed pursuit of commerce by ethnic minorities is usually explained historically or in terms of the content of the traders' culture. An examination of Mon traders in Thailand suggests that the ethnic difference itself is important in (1) freeing traders from constraints of the host society and (2) reducing stress inherent in face-to-face commercial transactions. These observations are subsumed into a concluding hypothesis relating ethnic differences to certain ritual activities, other kinds of social categorizations, and phenomena related to scale, all of which function in similar ways.
Alternative dynamic programming approaches to obtain upper bounds for the economic lot scheduling problem

Abstract We are considering the problem of choosing cyclical production patterns for several products, which are produced on a common production facility. By aggregating data, dynamic programming can be used to obtain upper bounds and feasible solutions. This paper illustrates alternative approaches when formulating one dimensional dynamic programming models. If only a certain class of strategies is considered, it is possible to give tighter bounds for the original state before aggregation. These improved bounds can be used to enlarge the set of feasible strategies within the considered class. This means, that when aggregating the state space, there exist different ways to limit the set of policies in order to be able to guarantee feasibility.
Human immunodeficiency virus counseling and testing practices among North Carolina providers.

Abstract OBJECTIVE: To estimate the percentage of prenatal care providers who offer human immunodeficiency virus (HIV) testing to pregnant women, investigate how strongly testing is encouraged, and explore testing barriers. METHODS: Between January 2001 and March 2001, we sent surveys to 1381 prenatal care providers in North Carolina, comprised of obstetricians, family physicians who practice obstetrics, and nurse-midwives. A total of 653 questionnaires were returned. RESULTS: Overall, 95.5% of providers who responded reported recommending HIV testing to all pregnant patients. Only 69.2% strongly recommend testing, with obstetricians (73.4%) and family physicians (70.1%) doing so at higher rates than nurse-midwives (55.9%). Almost all respondents (96.9%) strongly recommend testing for women they perceive to be high risk, whereas 39.7% strongly recommend testing to women who have had an HIV test in the past 6 months. When women refuse testing, 48.1% of practitioners inquire about the reason, and 28.2% reoffer the test at a future prenatal appointment. The most significant testing barriers were treating an HIV-positive woman (18.4%) and informing a patient she is HIV positive (14.8%). Respondents report that low literacy and culturally appropriate patient education materials would be most helpful to them. CONCLUSION: Among respondents, most prenatal care providers report that they recommend HIV testing to all pregnant women. However, many respondents base their decision about how strongly to recommend HIV testing on an assessment of the woman’s risk for HIV exposure. Significant barriers to offering HIV testing were associated with managing an HIV-positive patient. Providers were most in need of patient education materials.
Activity of the auditory system related to cortical arousal.

Abstract To determine whether or not the central auditory pathway shows variations in its activity which parallel changes in arcusal, multiple unit activity was recorded from the medial geniculate body, inferior colliculus, superior olivary complex, and cochlear nucleus in cats and was compared with simultaneously recorded electrocorticogram (ECoG) fluctations. Animals were paralyzed to assure auditory activity unconfounded by middle ear muscle contractions and movement-induced noise; extraneous outside noises were also carefully controlled. Under those conditions the medial geniculate body shows activity, both spontaneous and scund-elicited, which increases, usually linearly, as the amplitude of the cortical ECoG decreases. Lower auditory nuclei also vary their discharge, but in a more variable and unpredictable manner. The most common response observed among these lower nuclei was an increase in discharge during ECoG desynchronization, but with no change during the wide range of moderate- to high-amplitude ECoG. Present anatomical knowledge suggests the cortex as the most likely source of the geniculate effect. The mechanism responsible for modifying the activity of the lower auditory nuclei is not known, but the “descending auditory system” and efferents from the reticular formation are likely candidates.
WE-C-214-01: Is Medical Radiation Safe? Can It Be Safer?

Recent media publicity about patients injured by mistakes in radiation therapy and other patients receiving excessive doses from computed tomography has emphasized the need for improved measures to keep patients safe during medical procedures employing ionizing radiation. In a list of technology health hazards compiled by the ECRI Institute for 2011, radiation therapy is listed as number 1 and computed tomography is listed as number 4. Missing from these analyses is recognition of the profound health benefits of computed tomography and radiation therapy. Still, safety and quality can be improved through a variety of measures being implemented by medical physicists. These measures help to allay concerns that medical physics is not doing enough to improve quality and safety in both medical imaging and radiation therapy.
Liberation modeling and parameter estimation for multicomponent mineral systems

Abstract A mathematical model has been developed to simulate the size reduction/liberation behavior of complex ores for the cases of batch and open-circuit continuous grinding. As compared with other models of this type reported in the literature, this one is absolutely free from restrictions on the number of mineral components and composite particle classes which can be represented. A modified Levenberg—Marquardt algorithm and a finite difference Jacobian are used in conjunction with the model equations to estimate all kinetic parameters. The estimation scheme is validated for a binary ore with five composite particle classes, while the model is used to simulate the liberation behavior of a ternary ore with five composite particle classes for each composite type.
"Ambient Temperature Isoelectronic Detectors: Status and Prospects

Potential use of high-Z semiconductor detectors operating in the charge collection mode as ?-ray spectrometers at ambient temperatures appears to be limited by charge collection problems. Improvements in present scintillators through improved linearity and higher fluorescent efficiency appear possible. T. C. Madden, et al., 1 suggested the use of isoelectronic scintillators as an improved scintillator material. We have studied the possibility of using one of these, Te doped CdS, as a ?-ray spectrometer.
Surface-Chemical Studies on Chlorhexidine and Related Compounds: 1. Effects at Air-Water, n-Hexane-Water, and Hydroxyapatite-Water Interfaces

The comparative ability of chlorhexidine diacetate and structurally related compounds to generate surface pressure at air-water and n-hexane-water interfaces, and to adsorb to hydroxyapatite, was determined. The order of effectiveness generally evident was 1-(p-chlorophenyl)-5-n-octylbiguanide acetate >> chlorhexidine diacetate ≥ 1-(p-chlorophenyl)-5-n-hexylbiguanide acetate > 1-(p-chlorophenyl )-5-n-propylbiguanide acetate > p-chlorophenylbiguanide acetate ~ p-chloro-phenylguanidine acetate.
Gauge bosons in superstring theory

Abstract Gauge bosons in the Ramond-Ramond sector of four-dimensional models based on the superstring are analyzed. The normalization of degenerate bispinor vacuum states is compared with that of Neveu-Schwarz gauge bosons, an explicit k0 dependence is shown to be isolated when the polarization vectors are chosen to be in ϵ0 = 0 gauge; a spin decomposition is derived, and an orthonormal basis for the space of states is defined. Because of the physical state conditions, the bispinors are given as solutions to the Dirac-Ramond equations in the covariant gauge. Aspects of the DKV no-go theorem for non-abelian gauge bosons in this sector are discussed. The on-shell three-point amplitudes involving massless particles of this type are derived in the BRST superghost formalism, and their role in superstring phenomenology is described.
Complementary RNAs in paramyxovirions and paramyxovirus-infected cells.

PARAMYXOVIRIONS contain single-stranded RNAs sedimenting at 50–57S1–3, Newcastle disease virus (NDV) and Sendai virus have been shown to induce infected cells to synthesize single-stranded RNAs which sediment more slowly than virion RNAs and are complementary to them in nucleotide sequences4–6. Interest in these complementary RNAs derives from the possibility that they are templates for viral proteins. For some RNA viruses it is clear that the viral genome is the message7–10; but for paramyxoviruses, the genome may contain little or no genetic information that can be translated directly. Paramyxoviruses do not seem to be unique: vesicular stomatitis virus (VSV) directs the synthesis of RNAs smaller than virion RNA and complementary to it11,12.
On decimal sequences (Corresp.)

The properties of decimal sequences of rational numbers are investigated with the idea of using them as random sequences and error-correcting codes, and in other applications in communications. Several structural properties of decimal sequences are presented with special attention being given to binary decimal sequences and reciprocals of primes. For a certain class of decimal sequences of l/q, q prime, it is shown that the digits spaced half a period apart add up to r - 1 , where r is the base in which the sequence is expressed. Also for the same class all subsequences of length m , where r^{m} > q , are distinct. These underlying structural properties have made it possible to establish a lower bound on the Hamming distance between a given sequence and its cyclic shifts and also to obtain an upper bound on the autocorrelation function. A condition for the cross correlation of two decimal sequences being zero has also been obtained. The outcome of the calculations on decimal sequences of several primes is presented, and the results indicate that the autocorrelation function approximates that obtained for sequences of independent, equally likely random digits.