cssi/SciSciGPT-SciSciNet huggingface dataset:
Mathematical model for describing cerebral oxygen desaturation in patients undergoing deep hypothermic circulatory arrest

Background Surgical treatment for aortic arch disease requiring periods of circulatory arrest is associated with a spectrum of neurological sequelae. Cerebral oximetry can non-invasively monitor patients for cerebral ischaemia even during periods of circulatory arrest. We hypothesized that cerebral desaturation during circulatory arrest could be described by a mathematical relationship that is time-dependent. Methods Cerebral desaturation curves obtained from 36 patients undergoing aortic surgery with deep hypothermic circulatory arrest (DHCA) were used to create a non-linear mixed model. The model assumes that the rate of oxygen decline is greatest at the beginning before steadily transitioning to a constant. Leave-one-out cross-validation and jackknife methods were used to evaluate the validity of the predictive model. Results The average rate of cerebral desaturation during DHCA can be described as: S ct o 2 [ t ]=81.4−(11.53+0.37× t ) (1−0.88×exp (−0.17× t )). Higher starting S ct o 2 values and taller patient height were also associated with a greater decline rate of S ct o 2 . Additionally, a predictive model was derived after the functional form of a ×log ( b + c ×δ), where δ is the degree of S ct o 2 decline after 15 min of DHCA. The model enables the estimation of a maximal acceptable arrest time before reaching an ischaemic threshold. Validation tests showed that, for the majority, the prediction error is no more than ±3 min. Conclusions We were able to create two mathematical models, which can accurately describe the rate of cerebral desaturation during circulatory arrest at 12–15°C as a function of time and predict the length of arrest time until a threshold value is reached.
Management of Cervical Esophageal Carcinoma.

Surgery and radiotherapy yield equivalent results for patients with carcinoma of the cervical esophagus, with long-term survival of less than one in four patients. The advantages of radiotherapy are lower rates of acute morbidity and mortality compared with surgery, and potential for larynx preservation. The advantage of surgery is that the transposed stomach may function better over the long term than an irradiated esophagus, which tends to become stenotic over time. Patients with resectable cancers who are in good general medical condition may be treated with preoperative irradiation and surgery in an effort to improve the likelihood of local control and obtain a good functional result. Patients with relatively early lesions who are not good surgical candidates can be treated with high-dose radiation therapy. Patients with very advanced local disease and those with distant metastases are treated with palliative irradiation. Concurrent chemotherapy and radiotherapy has been shown to be superior to radiotherapy alone in managing esophageal cancer. Although relatively few patients with cervical esophageal cancer have been treated with this combination, some studies suggest it may be curative for patients with early lesions of the cervical esophagus, without the need for esopha-gectomy. Adjuvant chemotherapy is usually not used outside of a study setting.
Jamming the ratchet of transcription

The exact mechanism by which cellular RNA polymerases translocate and maintain exceptionally high fidelity during transcription remains an important unresolved issue. Two recent structural studies of yeast RNA polymerase II in complex with its potent inhibitor, the fungal toxin α-amanitin, address this matter by describing crucial and surprising details about the dynamic organization of the enzyme catalytic center.
Cornelia de Lange syndrome, cohesin, and beyond

Cornelia de Lange syndrome (CdLS) (OMIM #122470, #300590 and #610759) is a dominant genetic disorder with multiple organ system abnormalities which is classically characterized by typical facial features, growth and mental retardation, upper limb defects, hirsutism, gastrointestinal and other visceral system involvement. Mutations in three cohesin proteins, a key regulator of cohesin, NIPBL, and two structural components of the cohesin ring SMC1A and SMC3, etiologically account for about 65% of individuals with CdLS. Cohesin controls faithful chromosome segregation during the mitotic and meiotic cell cycles. Multiple proteins in the cohesin pathway are also involved in additional fundamental biological events such as double-strand DNA break repair and long-range regulation of transcription. Moreover, chromosome instability was recently associated with defective sister chromatid cohesion in several cancer studies, and an increasing number of human developmental disorders is being reported to result from disruption of this pathway. Here, we will discuss the human disorders caused by alterations of cohesin function (termed 'cohesinopathies'), with an emphasis on the clinical manifestations of CdLS and mechanistic studies of the CdLS-related proteins.
Use of serum prolactin in rats as a determinant in detecting endophyte infected tall fescue seed.

ABSTRACTThe purpose of this study was to examine the effects of endo-phyte (Acremonium coenophialium) toxic tall fescue seed on serum prolactin, daily feed intake, and average daily weight gain in male rats. Thirty Sprague-Dawley male rats (218 g) were randomly assigned to treatments of (I) rat chow (50%) plus an endophyte-free tall fescue seed (50%), (II) same as I only restricted feed intake as III, (III) rat chow (50%) plus endophyte infected tall fescue seed (50%) and (IV) rat chow (50%) plus endophyte infected tall fescue seed (25%) plus endophyte free tall fescue seed (25%). Dry matter intake and average daily gain were lower (P<.05) for rats fed treatment II and III than for those fed treatment I and IV, with treatment IV being lower (P<.05) than treatment I. Body weights on days 4, 11 and 21 followed the same trend with the rats fed treatment I having higher weights at each weigh period than those on treatments II, III and IV; and those fed treatment IV having higher weights at each period than th...
21‐Aminosteroids Interact with the Dopamine Transporter to Protect Against 1‐Methyl‐4‐Phenylpyridinium‐Induced Neurotoxicity

U-78518F, a 21-aminosteroid from the novel family of lipid peroxidation inhibitors (lazaroids), increased survival of dopamine (DA) neurons in mesencephalic cell cultures incubated with the neurotoxin 1-methyl-4-phenylpyridinium (MPP+). Protection against DA neuron death occurred with increasing concentrations of U-78518F up to 30 microM. Non-specific toxicity produced with higher concentrations of MPP+ was not affected by the lazaroid. U-78518F inhibited cellular uptake of [3H]MPP+ and [3H]DA, but not that of gamma-[3H]aminobutyric acid. In human striatal membrane preparations, U-78518F competed with [3H]mazindol for binding to the DA transporter, with a calculated Ki value of 10 microM. Two of four lazaroids tested inhibited [3H]DA uptake in the cell culture system. The protective effects of 21-aminosteroids in MPP(+)-induced neurotoxicity are, in part, a function of the interaction of these agents with the DA transporter.
Human T cell proteins recognized by rabbit heteroantisera and monoclonal antibodies

Many structural and functional features of the cell surface antigens of human T cells remain to be characterized. In these investigations, heteroantisera have been used to identify potentially interesting antigens not yet recognized by individual monoclonal antibody preparations. These antigens include patterns of bands (Mr 140-240K) on various T cells and T cell lines, at least six other bands on T cell lines and novel antigens on CTL lines. The majority of these antigens are different from the compiled list of antigens recognized by monoclonal antibodies against T cell proteins. The monoclonal OKT9 recognizes an antigen most prevalent on dividing cells, and this antigen is the same as that recognized by another monoclonal antibody, 5E9, and by previously described heteroantisera. The monoclonal antibody 4F2 has a distribution similar to OKT9, but it is structurally distinct, and is also present on monocytes. Three T cell surface proteins, two defined by the monoclonal antibodies OKT6 and OKT10, recognize proteins which resemble HLA antigens physiochemically. OKT6 and NAI/34 both recognize a 49,000 glycoprotein which is associated with a 12,000 subunit which reacts with anti-beta 2-microglobulin antibodies. OKT10 recognizes a 46,000 protein, also found with a 12,000 peptide, while the third protein, a beta 2-microglobulin-associated glycoprotein of 43,000 is not yet defined by a monoclonal Ab. Other monoclonals described here include 3A1 and PVR-11, which are on subsets of peripheral T cell, and B1-192 and B1-499 which are on some activated T cells.
The effects of the welfare system on marital dissolution

The economic theory of marriage predicts that the partners’ expectations of greater financial resources outside of marriage should increase the probability of marital dissolution. One potential implication is that marriages should be less stable in states with higher AFDC benefits. I study this implication empirically using data on separations and divorces among marriages involving women in the National Longitudinal Survey of Youth. I find no supporting evidence that higher welfare benefits lead to increased rates of marital dissolution among married women with children.
New communication protocols from old

The power tier automaton (PTA) is introduced as a model of preference for representing and manipulating systems in general, computer architectures and, in particular, communication networks and their protocols. The PTA is superior to Petri nets, both in computing power (Turing machine power) and in ease and selectivity of representation. The tier automaton, a species of the PTA, is used to represent networks and protocols to a greater advantage than other existing models. Homomorphisms and reachable-domain (r.d.) homomorphisms on tier automata are introduced and used to manipulate two distinct protocols for reliable full-duplex transmission over half-duplex lines, both of whose images are the same familiar alternating-bit protocol.
Askin's tumor in children: report of two cases

Two cases of Askin's tumor of the thoracopulmonary region in children (a 6-year-old female and a 5-year-old male) are presented. Primary surgery was unfeasible and despite aggressive chemotherapy both died within 304 and 300 days, respectively, from the onset of the disease. Although rare, Askin's tumor should be considered in the differential diagnosis of any thoracopulmonary mass in childhood and adolescence through appropriate histology and immunohistochemistry of incisional biopsies. Its prognosis is poor unless radical surgery is performed as soon as possible: unresectable tumors can be treated with chemotherapy, but prolonged chemotherapy yields potentially lethal complications. We conclude that only early diagnosis and cytogenetic recognition can give children with Askin's tumor a chance of curative surgery.
Epinephrine-induced reversal of aspirin effects on platelet deformability.

Abstract The present study has evaluated the influence of epinephrine on the resistance of platelets to aspiration into micropipettes, and the effect of epinephrine on the altered deformability of aspirin treated platelets. Unlike other platelet agonists previously studied, epinephrine stimulation did not alter platelet deformability at a concentration capable of causing platelet aggregation. Aspirin caused a dramatic decrease in the resistance of platelets to aspiration. Pretreatment of platelets with epinephrine prevented aspirin from altering platelet deformability, and exposure of platelets to epinephrine after treatment with aspirin reversed the increased deformability produced by the drug. Blockade of alpha-2 adrenergic receptors with yohim-bine or clonidine prevented epinephrine antagonism of the mechanical effects of aspirin. The studies provide further evidence of the novel antagonism between epinephrine and aspirin on platelet structure and function.
Theoretical studies of laser-stimulated surface processes: II. Desorption

In this paper, we develop a master equation approach to treat laser-stimulated desorption. We then apply this approach to study the effect of IR laser intensity and frequency on the yield of laser-stimulated desorption. We find that the dependence of the desorption yield on laser intensity and frequency are sensitive to the number of photons required to initiate the desorption. As the number of photons required increases, the yield decreases and the yield versus laser-frequency curve sharpens compared to the IR absorption of the adsorbed species. In particular, we conclude that the available experimental data on the CO2-laser-stimulated desorption of pyridine from a Ag surface is consistent with that being a two-photon process.
Raffinose accumulation in maize embryos in the absence of a fully functional Vp1 gene product

The maize (Zea mays L.) Viviparous-1 (Vp1) gene encodes the cotranscriptional activator VP1 protein and regulates biosynthesis of anthocyanins, sensitivity to abscisic acid, repression of α-amylase, and other factors related to quiescence during embryo maturation. Five mutant vp1 alleles were used to determine if the Vp1 gene regulates raffinose accumulation and the onset of desiccation tolerance in isolated embryos. Embryos of wild-type Vp1-R (purple, non-viviparous) kernels acquired desiccation tolerance to fast drying in association with a sucrose:raffinose mass ratio of 10:1 or lower. After slow drying, germinability was related to stage of embryo development. Embryos of mutant vp1-R (yellow, viviparous) kernels, in which the Vp1 gene is not expressed, accumulated only trace amounts of raffinose and never acquired desiccation tolerance. Embryos from kernels (yellow, non-viviparous) carrying the modified mutant allele vp1-McWhirter (which encodes a VP1 protein that is truncated at the C-terminal end), the “Coe” mutant allele vp1-1695, or the mutant alleles vp1-A1 or vp1-C821708 all become quiescent. Developing embryos of kernels with the modified mutant alleles vp1-McWhirter and vp1-1695 were desiccation tolerant in association with the sucrose:raffinose mass ratio having a value of 20:1 or lower. Embryos from wild-type kernels segregated on the same ears (Vp1-1695, purple) also were desiccation tolerant in association with a sucrose:raffinose mass ratio of less than 20:1. The acquisition of desiccation tolerance in developing maize embryos may be associated with raffinose accumulation, and raffinose biosynthesis may occur in the absence of a fully functional Vp1 gene product.
Role of Calcium in the Seasonal Modulation of Pacemaker Activity in a Molluscan Neurosecretory Cell

MOLLUSCAN ganglia contain several pacemaker neurones that spontaneously generate slow membrane potential oscillations associated with a burst of spikes during the depolarising phase (bursting pacemaker potential, or BPP)1–5. One such neurone, a neurosecretory cell in land snails, produces BPPs when the snail is active, but is typically silent and could not induce BPP activity during aestivation (hibernation)6–8. We report here that calcium is important in the seasonal modulation of this cell's BPP activity.
Relationship Violence and Psychological Distress Among Low-income Urban Women

In this paper, we examined the association between relationship violence and psychological distress among low-income urban women. Extending prior research, we considered the effects of relationship violence within the context of other chronic stressors that are common in the lives of these women. Using data from the Welfare, Children, and Families project (1999), a probability sample of 2,402 low-income women with children living in low-income neighborhoods in Boston, Chicago, and San Antonio, we predicted psychological distress with multiple measures of relationship violence, a wide range of sociodemographic variables, and several chronic stressors. Our results show that relationship violence is associated with higher levels of economic hardship, neighborhood disorder, and household disrepair. We also find that relationship violence is associated with higher levels of psychological distress, net of these other chronic stressors. Finally, we observe that the effects of relationship violence do not vary according to the chronic stressors under study. Because the adverse effects of relationship violence are similar for women despite other adverse circumstances, interventions and treatment efforts focused exclusively on relationship violence may make a unique contribution to the psychological well-being of low-income urban women.
Factors affecting migration patterns of juvenile river herring in a coastal Massachusetts stream

Juvenile anadromous river herring (alewives, Alosa pseudoharengus, and blueback herring, Alosa aestivalis) spend 3–7 months in freshwater before migrating to the ocean, often exhibiting waves of early and late migrations. Migratory patterns and associated abiotic and biotic factors were examined for both species migrating in 2003 from Herring River in Bourne Massachusetts. Migrating herring were grouped into two temporal periods and separated by species. Relationships between abiotic (water temperature, lunar phase, and precipitation) and biotic (size, age, growth rate, and hatch date) factors and the timing of out-migration (transition to seawater) were examined. Blueback herring migration coincided with a sharp decrease in temperature consistent with the time of year. Peaks in alewive migration may reflect adaptive traits maximizing likelihood of survival through seasonal marginal stream habitats and also avoiding lethal water temperatures in winter. Migrating bluebacks exhibited a single migratory period (late September–October) which occurred between the early and late migratory pulses of the alewives. These patterns may also represent distinct migration strategies between early and late migrating alewives and between the two species of river herring. Early migration may be a mechanism by which factors such as competition and low food availability are mitigated. In contrast, environmental conditions during the post hatching time of late migrators may allow for a size maximizing strategy that promotes migration from the nursery area as late as possible.
Form and function of protein assemblies.

Assemblies of protein molecules represent a fundamental level of biological organization. The dynamic behavior of these systems–including both the assembly process and functional rearrangements–may be accounted for by the specificity of the protein interactions, which depend on environmental conditions. Analysis of the self-assembly of virus particles has established that the design of an ordered structure can be built into the specific bonding properties of the constituent proteins. Any structure which can change its state of organization is, by definition, polymorphic. The distinctive aspect of polymorphism in protein structures, contrasted with nonliving states of matter, is that the molecular design has been selected to carry out a function and that this function is part of an integrated system. The differences in molecular conformation and arrangement in all polymorphic structures–for example, allosteric enzymes or ice crystals–depend on the intrinsic interaction properties of the molecules themselves. The structures of ice and water illustrate relations between specificity and polymorphism which are relevant to the form and function of protein assemblies. Two types of polymorphism can be distinguished: modal polymorphism, which is externally moderated, as in phase transitions between different crystals forms; and positional polymorphism, which is internally moderated, as in the different disposition of identical molecules within a single crystal lattice. Positional polymorphism, exemplified by the quasi-equivalent bonding of icosahedral virus coat proteins and the different arrangement of myosin and paramyosin at the center and polar portions of the bipolar filaments, results from specific interactions that are not compatible with a strictly equivalent packing of identical molecules. The structural rearrangements in muscle contraction and the switching between the oxy and deoxy forms of hemoglobin represent the formation of different structures in response to altered external conditions. The different structural states of many protein assemblies are characterized by conserved connections which may be regarded as providing the framework for functional rearrangements. The types of polymorphism displayed by hemoglobin, virus, and muscle proteins demonstrate the relevance of the simple view that the function of a protein is determined by the potential structures it can form.
A gasoline fuel processor designed to study quick-start performance

A fast-start capability is a key requirement for on-board fuel processors for automotive fuel cell systems operating on gasoline fuel. This paper reports on the design and fabrication of a suitable fuel processor having this capability and discusses estimates of the start-up fuel consumption for the laboratory unit. Also discussed are the start-up strategy and the results of a start-up simulation, which showed that the fuel processor can deliver 90% of the rated hydrogen capacity in 60 s, producing a product gas that contains >30% hydrogen and 2.9 MJ of fuel energy.
The relationship between localization and the Franssen effect

The relationship between localization and the Franssen effect was studied for noise and tones in a sound-deadened and in a live room. The noise was wideband and the tones were 250, 500, 1000, 1500, 2500, and 4000 Hz. Listeners were asked to determine the location of the stimuli in a localization task and to discriminate the difference between a pair of stimuli used to generate the Franssen illusion and a steady-state tone in a Franssen-effect discrimination task. Poor performance in the Franssen-effect discrimination task is consistent with the stimulus conditions leading to a strong Franssen illusion. Poor performance in both the Franssen effect and localization tasks was obtained for midfrequency tones (near 1500 Hz) and in the live room. Thus, the Franssen illusion is strongest for a live room and for midfrequency tones consistent with the difficulty listeners have in localizing sounds under these conditions. These results are consistent with those of Hartmann and Rakerd [J. Acoust. Soc. Am. 86, 1366–1373 (1989)] and support their suggestion of a correlation between the Franssen effect and localization in rooms.
Foucault's Untimely Struggle Toward a Form of Spirituality

In his series of essays on Kant written during the 1980s, Michel Foucault attempted to discern the difference today made with respect to yesterday. As his essays as well as his lectures (especially...
Covalent linkage of phosphoinositides to myelin basic protein: in vitro incorporation of [32P] phosphoinositides to myelin basic protein.

Abstract We have previously reported that the covalent attachment of phosphoinositides to myelin basic protein (MBP) occurs both in vivo and in vitro [Smith, R. A. et al. (1986) Biochemistry 25:2677–2681; Biochemistry 25:2682–2686; and Biochem.Biophys.Res.Comm. 316:426–432]. Phosphoinositidation of MBP was also detected when [ 32 P]phosphoinositides were incubated with myelin pretreated with Triton X-100 and EGTA. Less than 10% of this covalent linkage of phosphoinositides to MBP survived after acidic treatment (0.1 N HCl at 37°C for 10 min). MBP is predicted to lack sufficient hydrophobicity to bind to membranes as shown by analysis of its amino acid sequence for hydrophobic regions and thus its phosphoinositidation may provide an anchor for this purpose.
Abstract A54: Potential mechanisms of resistance to targeted agents in human clear cell renal cell carcinoma

Targeted therapy with multiple receptor tyrosine kinase inhibitors (RTKI) has led to a substantial improvement in the standard of care for patients with advanced or metastatic clear cell renal cell carcinoma (CCRCC). We have previously reported that using a phosphoproteomics approach, Ras and Rab interactor 1 (RIN1) was identified as a potential target modulating the antiproliferative effects of sorafenib and sunitinib in a panel of human CCRCC (Proc. AACR 51: Abst. #1626, 2010). While both 10 μM sorafenib and 7.5 μM sunitinib were effective in down-regulating RIN1 protein levels in CCRCC following treatment for 48h, during subsequent recovery for 48h in drug free medium, recovery of RIN1 protein levels was observed in sorafenib but not sunitinib treated cells. mRNA expression profiling revealed that: (a) VEGF-A and HIF-1α levels were unaffected during 48h treatment with sorafenib or sunitinib or subsequent recovery; and (b) while HIF-2α levels were increased >2-fold following 48h exposure to sorafenib or sunitinib, during subsequent recovery in drug-free medium, the increased levels of HIF-2α persisted in cells treated with sorafenib but not sunitinib. Compared to CCRCC cells that were growth inhibited in vitro at concentrations of 5–10 μM sorafenib or sunitinib, in 27 patient CCRCC samples evaluated, the median mRNA levels of RIN1 was 7.2-fold lower in 22 samples (Range 1.6–22.3) and 2.2-fold higher in 5 samples (Range 1.2–27.1). Stable over-expression and down-regulation of RIN1 in CCRCC led to resistance or sensitivity respectively, to the anti-proliferative effects of sorafenib and sunitinib but not the mTOR inhibitor temsirolimus. In contrast, CCRCC cells adapted to proliferate in 4 μM everolimus exhibited a >3-fold increase in IC50, and cross-resistance to temsirolimus but not sorafenib or sunitinib. Evaluation in vitro of other targeted agents, demonstrated dose-dependent anti-proliferative effects with the PI3K/mTOR dual inhibitor BEZ235 (>80% growth inhibition at 10nM) but not the pan-PI3K inhibitor BKM120 ( 85% growth inhibition) in CCRCC cells expressing resistance to everolimus. These results suggest the PI3K/mTOR dual inhibitor BEZ235 may possibly improve the treatment efficacy of mTOR inhibitors for CCRCC. The findings suggest RTKI and mTOR inhibitors have distinct mechanisms of resistance, and combinations may be useful to improve disease control of metastatic CCRCC.
The sign invariance of certain norms on

Let denote the set of all n×1 real column vectors and let Δn denote the group of all n×n diagonal matrices over whose diagonal entries have absolute value one. A norm ∥⋅∥ on is said to be sign invariant of Given a norm ∥⋅∥ on and an m×n real matrix H of rank n on can define a norm ∥⋅∥ H on by In this note we study the following problem. If ∥⋅∥ p is the lp norm on then what conditions on H will entail that ∥⋅∥ H,p is sign invariant.
Towards accommodating the ‘tragedy of the commons’ effect in language policy development

A typical scenario: a language revitalization plan is developed within a language ecology that contains a dominant language, e.g. English. The plan is implemented in ways that inculcate the wishes of minority language speakers. Sadly, significant language shift toward the dominant language continues. The policy seems to have had little effect. What went wrong? I assert that a partial explanation lies in the failure within the language policy and plan to account for a human socio-economic behavioral pattern described by Hardin as ‘the tragedy of the commons’ ([1969]. Science, 162, 1243–1248). With respect to language shift, the commons tragedy proceeds thusly: ‘I am the head of a household and a member of a community that speaks a threatened language. We want to preserve our finite, shared language resource (the commons). However, it is very beneficial for my children to acquire high proficiency in English. The cost is diminished first language proficiency. That cost, however, is shared with the total spee...
Teaching cardiorespiratory physiology in the emergency department

In recognition of the application of basic science to clinical medicine, and because the emergency department offers a unique opportunity for this teaching, an educational program was developed especially for the teaching of cardiorespiratory physiology. The method of conducting such an educational program is described, as are the principles to be learned. Testing scores have shown a marked improvement in the students' performance.
The Paradoxes of Post-War Italian Political Thought

Summary This article examines the complex nature of post-war Italian political thought, stressing the importance of Italy's unusual institutional and historical political arrangements, but also the vibrancy of its political ideologies in this period. In the past it has often been argued that the dysfunctional nature of post-war Italian democracy with its rapidly changing governments, and widespread corruption—which nonetheless coexisted with the one party, the Christian Democrats, being constantly in power—led to the atrophying of political theory in general, and political ideologies in particular. But this picture is strongly disputed here—on the contrary it is argued that Christian Democratic, Left and liberal political ideologies were all complex and interesting. Thus if Christian democracy should ultimately be seen as an ‘ideology of transition’ which existed to help Catholicism adapt to the parameters of modern mass democracy, and which lacked a thinker of the calibre of Jacques Maritain, it neverthe...
Comment: Dimensional Analysis and Experimentation as a Catalyst to Learning From Data

Commentary based on the article, "Experimental Design for Engineering Dimensional Analysis" by Mark C. Albrecht, Christopher J. Nachtsheim, Thomas A. Albrecht & R. Dennis Cook published in the journal Technometrics, volume 55, issue 3.
Photoreduction of ferredoxin-NADP in the presence and absence of ferredoxin-reducing substance (FRS).

Abstract Preparations of ferredoxin-reducing substance (FRS) were obtained from spinach chloroplasts within the elution volume range and with the spectral characteristics described by Yocum and San Pietro (8). However, no support was found for the view that FRS is the primary electron acceptor of Photosystem I. The FRS-depleted chloroplast fragments retained their Photosystem I activity, which was not enhanced by the addition of FRS. No evidence was found for a prior photoreduction of FRS by chloroplasts followed by a dark reduction of ferredoxin and NADP by reduced FRS. The FRS-depleted chloroplast fragments were found to retain and to photoreduce bound ferredoxin upon illumination by Photosystem I light at 25°K. These results suggest that the role of a primary electron acceptor of Photosystem I ascribed to FRS may belong to bound ferredoxin.
Knowledge structure and subject access

Previous studies of library on-line catalogs [5], have identified subject searching as both the most popular method of access as well as the most problematic. These findings have stimulated a large amount of research on subject or topical access, most focusing on the vocabulary of the subject headings list and ways to improve its richness (e.g. [4]) There have been fewer explorations of the problems inherent in the structure of the Library of Congress Subject Headings (LCSH) and how this structure combined with user's knowledge structure contributes to the subject searching problem. Because knowledge structure has been shown to differentiate between novices and experts [2], and because expertise affects success in searching online catalogs [1], knowledge structure may play a role in subject searching. Results from a previous field study have confirmed these expectations. Therefore, to further test this hypothesis, this study examines how the knowledge structures of experts and novices in a given field differ from the structures of librarians and the LCSH for that field.
Behavioural and electrodermal measures of lateralization for music perception in musicians and nonmusicians.

Abstract Two groups of students, musicians and nonmusicians were tested on a dichotic listening forced choice recognition task with concurrent recording of bilateral electrodermal activity. Stimuli were excerpts of Bach 4-part chorales: probes were the soprano, bass, harmony or the chorale excerpt, with or without changed notes. Laterality effects in recognition and the GSR were obtained only in musicians as a function of the complexity of the task. It was concluded that styles of information processing assumed by the hemispheres are the consequence of an interaction between the stimulus and the state of the organism at the moment, such that the direction of laterality can change within a subject performing the same task depending upon its perceptual demand.
RADIATION-INDUCED POLYMERIZATION OF 3,3,4,4,5,5,5-HEPTAFLUOROPENTENE-1 AT HIGH PRESSURE.

A study was made of the radiation-induced polymerization under pressure of 3,3,4,4,5,5,5-heptafluoropentene-1. Polymerization rates increase with pressure (activation volume equals − 11 cc/mole) and temperature (activation enthalpy equals 6.5 kcal/mole) in liquid phase. At 13800 atm and 25°C, freezing occurs; the polymerization rate in the solid is very small. In liquid phase polymerization can continue for many hours after the irradiation is terminated. An active species is formed by radiation which initiates polymerization in the dark period.
Signatures of nucleon disappearance in large underground detectors

For neutrons bound inside nuclei, baryon instability can manifest itself as a decay into undetectable particles (e.g., $\stackrel{\ensuremath{\rightarrow}}{n}\ensuremath{\nu}\ensuremath{\nu}\overline{\ensuremath{\nu}}),$ i.e., as a disappearance of a neutron from its nuclear state. If electric charge is conserved, a similar disappearance is impossible for a proton. The existing experimental lifetime limit for neutron disappearance is 4--7 orders of magnitude lower than the lifetime limits with detectable nucleon decay products in the final state. In this paper we calculated the spectrum of nuclear de-excitations that would result from the disappearance of a neutron or two neutrons from ${}^{12}\mathrm{C}.$ We found that some de-excitation modes have signatures that are advantageous for detection in the modern high-mass, low-background, and low-threshold underground detectors, where neutron disappearance would result in a characteristic sequence of time- and space-correlated events. Thus, in the KamLAND detector, a time-correlated triple coincidence of a prompt signal, a captured neutron, and a ${\ensuremath{\beta}}^{+}$ decay of the residual nucleus, all originating from the same point in the detector, will be a unique signal of neutron disappearance allowing searches for baryon instability with sensitivity 3--4 orders of magnitude beyond the present experimental limits.
Equivariant Orthogonal Spectra and S-Modules

Introduction Orthogonal spectra and $S$-modules Equivariant orthogonal spectra Model categories of orthogonal $G$-spectra Orthogonal $G$-spectra and $S_G$-modules ""Change"" functors for orthogonal $G$-spectra ""Change"" functors for $S_G$-modules and comparisons Bibliography Index of notation.
Elimination of Sodium-24 and Potassium-42 Interferences in Activation Analysis of Biological Samples

We have developed a simple novel column technique for the removal of sodium-24 and potassium-42 based on a heterogeneous isotopic exchange reaction between an organic eluting solution (acetone-hydrochloric acid) and fine crystals of sodium chloride or potassium chloride or their analogs. The technique is fast, efficient, and highly selective; it has been successfully applied to irradiated human tissues prior to gamma-ray spectrometry with lithium-drifted germanium detectors.
Anionic Oxidative Polymerization: The Synthesis of Poly(phenylenedicyanovinylene) (PPCN2V)

A new polymerization technique that allows for the first-ever synthesis of poly(phenylenedicyanovinylene)s (PPCN2Vs) is described. PPCN2Vs, with their high electron affinities and structural versatility, seem ideally suited to address the need for new n-type polymers. Remarkably the polymers presented herein become more photoluminescent, in the thin film, under continuous irradiation.
TU-C-202-02: QA/QC in Diagnostic Ultrasound Imaging

A frequent source of fault in installed ultrasoundsystems is partial failure of regions on an array transducer, and quality control steps usually focus towards detection of these malfunctions. Electrically dead elements or delaminated regions can be detected using images of a uniform region of a tissue mimicking phantom. However, except for limited (i.e., 32) channel systems, dead regions on the transducer must be fairly extensive to visualize their effect on B‐mode images. If an electronic probe tester is not available, averaging uncorrelated images of the phantom increases the detectability of subtle array element dropouts. Phantom penetration tests also are useful for evaluating the integrity of the transducer and imagingsystem. Proper system setup for such tests includes correct placement of transmit foci and using the right settings for output and receiver gain. Penetration can be transferred from subjective assessments to objective measurements by measuring signal‐to‐noise ratios vs. depth. Comparisons of penetration results among systems are difficult because of a lack of standardization of phantom properties. Test object manufacturers could help by establishing data bases on typical penetration results for different transducer types and frequencies, and this would facilitate useful standardization. The role of certain “classical” ultrasoundquality control procedures involving features such as “dead zone,” axial and lateral resolution, and distance measurements will be discussed. Learning Objectives 1. Outline elements of a quality control program for ultrasoundsystems 2. Identify system components that require routine testing 3. Describe steps that the physicist should take to carry out QC on a regular basis
Single cell analysis of free cytosolic calcium changes in human lung mast cells--II. The relationship between desensitization and the cellular regulation of calcium changes.

Stimulation of mast cells results in two opposing reactions, activation events that cause degranulation and desensitization events that inhibit mediator release. Previous studies of human lung mast cells and murine mast cells have suggested that desensitization resulted from events that negatively regulated free cytosolic calcium ([Ca2+]i) levels; the current studies suggest otherwise. Stimulation of purified human lung mast cells with anti-IgE demonstrated that histamine release had reached a maximum at a time (5 mins) when [Ca2+]i levels were still near their maximum elevation. While there was a slow return of [Ca2+]i levels to baseline (T12 = 7.8 min), this rate of return could not clearly account for the cessation of histamine release. The heterogeneity in this decay parameter was also calculated to be insufficient to account for the heterogeneity in the peak calcium response while heterogeneity in the cell surface IgE density could adequately account for the heterogeneity in calcium responses. Preincubation of mast cells with anti-IgE antibody without extracellular calcium did lead to a progressive loss of the subsequent [Ca2+]i response when calcium was added back to the reaction, but the rate of desensitization determined by this measure, T12 of 8 min, was slower than the rate determined by measuring the progressive inhibition of histamine release (T12 of 4.5 min). In addition, no correlation existed for the rate of desensitization as measured by histamine relase and that measured by the peak calcium response. These data suggested that the extent of histamine release was not strictly controlled by regulation of free cytosolic calcium and that desensitization events measured by the progressive loss in histamine release and calcium response were also not strictly related.
Psychosocial mediators of a walking intervention among African American women.

Many Americans are sedentary and would reduce their disease risk if they increased their levels of physical activity to 30 minutes of moderate activity most days of the week. This descriptive explo...
Recurrent Themes in Ghanaian Politics: Kwame Nkrumah's Legacy

Over a quarter of a century after the demise of his government, Kwame Nkrumah continues to be a potent force in the politics of Ghana. When the Limann government was overthrown by Jerry J. Rawlings in December 1981, the groups that rallied to his support were made up essentially of those individuals whose political orientation was to the left and, more importantly, who considered themselves to be "radical Nkrumaist."' It can also be argued that in the early days of the Provisional National Defense Council (PNDC) "revolution," a sizable group of Ghanaians were drawn to Rawlings because of some obvious similarities between him and Nkrumah. His dramatic presence, his flamboyance, his dynamic oratorical style, the essence of his mode of leadership was remarkably reminiscent of what was considered, by many, as "the good old days" of strong and active Nkrumaist politics. And when they referred to him as J. J. (Junior Jesus), the connotation was purely secular. Just as the Messiah, Nkrumah "saved" Ghana from colonialism. So it was hoped that Rawlings, the second Messiah, would save the nation from bad government and moral degeneration. It is being hypothesized here that Nkrumah and what his era established are the fundamental basis of contemporary politics in Ghana. At both the leadership and the mass levels, the most important facets of Ghanaian politics, it seems, have been conditioned by the Nkrumah period. Parliamentary affairs and conduct, governmental effectiveness, the foreign policy options, the position of the judiciary vis-a-vis the other arms of government, perceptions of the
The neglected tropical diseases

For the equivalent of a few days' worth of military spending, devastating illnesses of the global poor could be controlled worldwide
Milk and fat yields decline in bovine leukemia virus-infected Holstein cattle with persistent lymphocytosis.

Abstract Effects of bovine leukemia virus (BLV) infection on milk and fat yields were studied by using data collected from Holstein cows over a 6-year period. Milk and fat yields in BLV-infected cows with persistent lymphocytosis (PL) declined significantly relative to their BLV-infected non-PL herdmates. Declines were most pronounced in cows older than 6 years. The estimated loss to the dairy industry due to PL is more than $42 million annually. A major histocompatibility complex class I (BoLA-A) allele that has been previously associated with resistance to PL was associated with longevity and realization of milk production potentials, indicating that genetic resistance to PL will have an economic benefit in herds where BLV is endemic.
Hepatocellular Carcinoma Screening Practices in the Department of Veterans Affairs: Findings from a National Facility Survey

Background Previous studies suggest low rates of hepatocellular carcinoma (HCC) screening in clinical practice. There is little information on the provider- and healthcare-facility-related factors that explain the use of HCC screening.
Spatial representations in discourse: Comparing spoken and signed language

Abstract The use of space in sign language discourse has been treated as a unique and almost defining characteristics of sign languages. This paper argues that the use of space in ASL is not conceptually different from the ‘use of space’ in spoken languages, where spatial representations can also be constructed to aid in discourse. Speakers of any language need to make clear whether they are describing elements within a non-grounded mental space (Fauconnier, 1985) or elements within a grounded mental space (Liddell, 1995). An English example demonstrates that speakers of a vocally produced language can easily set up spatial representations and that they typically make reference to such representations by making pointing gestures toward elements of those representations while speaking. The pointing gestures serve to show that the speaker is describing an element within a grounded mental space. Signers have the same need to distinguish between elements within a grounded or non-grounded mental space. They also make the distinction by making pointing gestures while signing. Sign languages contain classes of signs which combine the linguistically defined elements of a sign with gestural, pointing elements which are not linguistically defined. Thus, although the ‘use of space’ is not unique to sign languages, the means used by sign languages to simultaneously combine pointing gesture and sign appears to be unique.
Leptonic decay rates of charmonium S and D states

We calculate the leptonic decay rates of the {sup 3}S{sub 1} and the {sup 3}D{sub 1} states of charmonium including their relativistic and single gluonic radiative corrections within the framework of a nonsingular potential model proposed by Gupta, Johnson, Repko, and Suchyta. We find that the relativistic corrections and the single gluonic radiative corrections are both significant. But single gluonic radiative corrections are significantly smaller than the well-known static limit results. Since we work in a formalism where the quarks are assumed to be on mass shell, there is some ambiguity about treating the infrared divergent part of the radiative correction terms. {copyright} {ital 1997} {ital The American Physical Society}
The Lipid Peroxidation Product 4-Hydroxynonenal Facilitates Opening of Voltage-dependent Ca2+ Channels in Neurons by Increasing Protein Tyrosine Phosphorylation

Calcium influx through voltage-dependent calcium channels (VDCCs) mediates a variety of functions in neurons and other excitable cells, but excessive calcium influx through these channels can contribute to neuronal death in pathological settings. Oxyradical production and membrane lipid peroxidation occur in neurons in response to normal activity in neuronal circuits, whereas excessive lipid peroxidation is implicated in the pathogenesis of of neurodegenerative disorders. We now report on a specific mechanism whereby lipid peroxidation can modulate the activity of VDCCs. The lipid peroxidation product 4-hydroxy-2,3-nonenal (4HN) enhances dihydropyridine-sensitive whole-cell Ca2+ currents and increases depolarization-induced increases of intracellular Ca2+levels in hippocampal neurons. Prolonged exposure to 4HN results in neuronal death, which is prevented by treatment with glutathione and attenuated by the L-type Ca2+ channel blocker nimodipine. Tyrosine phosphorylation of α1 VDCC subunits is increased in neurons exposed to 4HN, and studies using inhibitors of tyrosine kinases and phosphatases indicate a requirement for tyrosine phosphorylation in the enhancement of VDCC activity in response to 4HN. Phosphorylation-mediated modulation of Ca2+ channel activity in response to lipid peroxidation may play important roles in the responses of neurons to oxidative stress in both physiological and pathological settings.
Recommendations for primary care physicians to improve HPV vaccination rates during clinical encounters.

The availability of the human papillomavirus (HPV) vaccine has positioned primary care physicians to play an active role in ensuring its successful implementation. However, physicians must be aware of common knowledge, attitudes, and belief barriers associated with HPV and the vaccine that are often encountered during clinical visits. This editorial provides primary care physicians an overview of these barriers and realistic recommendations utilizing the "5A's" – Awareness, Assess, Address, Acceptability, and Activate. This mnemonic can help facilitate a physician's systematic approach to increasing HPV vaccination rates during the clinical encounter.