cssi/SciSciGPT-SciSciNet huggingface dataset:
Computer Based Fluid Balance Records

Fluid balance data is essential for decision making regarding cardiovascular, respiratory, renal, and metabolic function; however, manual charting of fluid balance is characterized by three principal deficiencies: it is inaccurate, it reflects fluid volumes but not their compositions; and it masks long-term effects. In order to assess the accuracy of manual charting, we studied the records of 30 randomly selected patients, whose ICU admissions lasted four or more days, from five 6-bed ICU’s in our hospital. We found that 30 percent of the daily records were incorrect, and that only four patients had fully error-free records. Most errors were arithmetical; however, errors persisted even when calculators were used. Frequently, hourly entries were omitted from totals, and intakes were confused with outputs. In one case, a net intake of two liters was confused with a net output. These mistakes, as expected, were correlated with the number of intakes and outputs, indicating that patients with the most complex fluid management problems are least likely to have accurate records. The implications of this inaccuracy are clear.
Assessing Progress Toward Greater Equality of Income Distribution

In this chapter, Cary S. Fields raises more doubts about the income inequality data used in many studies and challenges the interpretation of those data. He begins by pointing out a number of flaws in the inequality data, noting that the approach to studying the question has almost always been to examine relative inequality. Through a series of numerical examples, Fields shows that relative inequality can increase while absolute poverty declines. He believes that the relative approach is fixated on subjective conditions, and he thinks it preferable to study the objective conditions under which the world’s poor live. Fields presents evidence to show that there is very little support for the inverted U curve first suggested by Kuznets. Further doubts are cast on the U curve through a brief examination of some historical trends in distribution. Finally, Fields reinterprets the Brazilian and Indian cases, showing that in spite of worsening relative inequality in Brazil, absolute poverty declined, whereas in India absolute poverty worsened significantly even though the distribution of income did not.
L-selectin is not required for T cell-mediated autoimmune diabetes

Administration of anti-L-selectin (CD62L) mAb to neonatal nonobese diabetic (NOD) mice mediates long term protection against the development of insulitis and overt diabetes. These results suggested that CD62L has a key role in the general function of β cell-specific T cells. To further examine the role of CD62L in the development of type 1 diabetes, NOD mice lacking CD62L were established. The onset and frequency of overt diabetes were equivalent among CD62L +/+ , CD62L +/− , and CD62L −/− NOD littermates. Furthermore, patterns of T cell activation, migration, and β cell-specific reactivity were similar in NOD mice of all three genotypes. Adoptive transfer experiments with CD62L −/− CD4 + T cells prepared from BDC2.5 TCR transgenic mice revealed no apparent defects in migration to pancreatic lymph nodes, proliferation in response to β cell Ag, or induction of diabetes in NOD. scid recipients. In conclusion, CD62L expression is not essential for the development of type 1 diabetes in NOD mice.
Quantifying the Dynamic Ocean Surface Using Underwater Radiometric Measurement

Abstract : The primary focuses of this research are to understand the requirements of the inverse modeling of seasurface processes on the accuracy, resolution, and coverage of underwater unpolarized and polarized light-field measurements, to master the theoretical constraints and computational resources required of the modeling and simulation, and to improve the forward theoretical and simulation prediction capabilities in terms of accuracy and efficiency. We aim to investigate the feasibility and limitations of achieving the inverse problem of modeling the ocean surface using underwater light measurements. Our ultimate goal is to establish an efficacious, robust framework for the unique and efficient solution of the inverse problem in terms of both the statistical characterization and direct phase-resolved prediction of the ocean surface.
FMR spectra of oriented /spl gamma/-Fe/sub 2/O/sub 3/, Co-/spl gamma/-Fe/sub 2/O/sub 3/, CrO/sub 2/ and MP tapes

Ferromagnetic resonance spectra have been measured at 34.5 GHz on oriented /spl gamma/-Fe/sub 2/O/sub 3/, Co-/spl gamma/-Fe/sub 2/O/sub 3/, CrO/sub 2/ and MP tapes. Particle orientation distribution functions were determined by measuring the angular dependence of remanence. The distribution functions were used to calculate FMR spectra using the Landau-Lifshitz equation and the method of Netzelmann. The anisotropy energy, packing fraction and damping constant were adjusted in order to fit the data. The values of the damping constants obtained from the fits ranged from a low of 0.051 for CrO/sub 2/ to a high of 0.92 for MP. These values, including previously measured damping constants for Ba-ferrite, correlate well with the switching speed measurements of Doyle and co-workers, which show CrO/sub 2/ to be the slowest and MP the fastest. >
Expression and secretion of chemotactic cytokines IL-8 and MCP-1 by human endothelial cells after Rickettsia rickettsii infection: Regulation by nuclear transcription factor NF-κB

Abstract Infection of endothelial cells (EC) with Rickettsia rickettsii results in Rocky Mountain spotted fever, an acute illness characterized by systemic inflammation. Interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) are important chemokines for activating neutrophils and monocytes, respectively, and recruiting these circulating immune cells to the sites of inflammation. In this study, we have measured the expression and secretion of these chemokines during R. rickettsii infection of cultured human EC. In comparison to uninfected controls, increased mRNA expression of IL-8 and MCP-1 in R. rickettsii -infected EC was evident as early as 3 h and was sustained up to 21 h. Subsequent analysis of culture supernatants revealed significantly enhanced secretion of both chemokines at 3, 8, and 18 h post-infection (5–28-fold increase in IL-8 and 4–16-fold increase in MCP-1). The presence of peptide-aldehyde compound MG132 to inhibit proteasome-mediated degradation of the inhibitory protein I κ B α and synthetic peptide SN-50 to inhibit the nuclear translocation of nuclear factor-kappa B (NF- κ B) resulted in significant inhibition of the chemokine response. Also, T24 cells expressing a super-repressor mutant of I κ B α (to render NF- κ B inactivatable) secreted significantly lower quantities of IL-8 than mock-transfected cells. A neutralizing antibody against IL-1 α or an IL-1 specific receptor antagonist had no effect on the early phase of R. rickettsii -induced NF- κ B activation and IL-8/MCP-1 secretion at 3 h. Both of these treatments, however, diminished late-phase NF- κ B activation by about 33% and only partially suppressed the infection-induced chemokine release at 21 h. Thus, while chemokine response early during the infection likely depends on the direct activation of NF- κ B, subtle autocrine effects of newly synthesized IL-1 α may contribute, in part, to the control of NF- κ B activation and chemokine production at later times. These findings implicate a prominent role for host EC in recruiting immune cells to the site of inflammation during Rickettsia infection and provide important insights to further our understanding of the pathogenesis of spotted fever group rickettsioses.
Impact of local property variations of reactor coolant on cladding temperature distribution in supercritical water reactors

Fluids at supercritical pressures are considered to be very promising as coolants for Generation IV reactor systems, including the supercritical water cooled reactor (SCWR), the CO2-cooled reactor (SCCO2R) and the Brayton cycle as a secondary system in sodium-cooled fast reactors. The operating conditions of such reactors allow for a significant thermodynamic efficiency increase of the respective power plants. On the other hand, several unresolved issues must still be addressed in order to develop a viable design of supercritical fluid nuclear systImpact of local property variations of reactor coolant on cladding temperature distribution in pupercritical water reactorsems. Examples include: in-core heat transfer in SCWRs, heat exchangers in the S-CO2 Brayton cycle, and flows in complex geometries of SCO2 compressors. It has been shown before that the understanding of the effect of fluid property variations on turbulence is a major factor in our ability to predict the combined fluid mechanics and heat convection in systems and components using supercritical fluids. The objective of this paper is to present the results of analysis on the effect of local multidimensional flow and heat transfer phenomena on the temperature distribution inside future SCWRs. Two proposed SCWR designs have been considered: a single-pass and a two-pass coolant flow configurations through the reactor core. It should be noted that a preliminary documentation of the results of the current work has been included in the materials of the NURETH-15 conference.
cGMP-independent nitric oxide signaling and regulation of the cell cycle

Regulatory functions of nitric oxide (NO•) that bypass the second messenger cGMP are incompletely understood. Here, cGMP-independent effects of NO• on gene expression were globally examined in U937 cells, a human monoblastoid line that constitutively lacks soluble guanylate cyclase. Differentiated U937 cells (>80% in G0/G1) were exposed to S-nitrosoglutathione, a NO• donor, or glutathione alone (control) for 6 h without or with dibutyryl-cAMP (Bt2cAMP), and then harvested to extract total RNA for microarray analysis. Bt2cAMP was used to block signaling attributable to NO•-induced decreases in cAMP. NO• regulated 110 transcripts that annotated disproportionately to the cell cycle and cell proliferation (47/110, 43%) and more frequently than expected contained AU-rich, post-transcriptional regulatory elements (ARE). Bt2cAMP regulated 106 genes; cell cycle gene enrichment did not reach significance. Like NO•, Bt2cAMP was associated with ARE-containing transcripts. A comparison of NO• and Bt2cAMP effects showed that NO• regulation of cell cycle genes was independent of its ability to interfere with cAMP signaling. Cell cycle genes induced by NO• annotated to G1/S (7/8) and included E2F1 and p21/Waf1/Cip1; 6 of these 7 were E2F target genes involved in G1/S transition. Repressed genes were G2/M associated (24/27); 8 of 27 were known targets of p21. E2F1 mRNA and protein were increased by NO•, as was E2F1 binding to E2F promoter elements. NO• activated p38 MAPK, stabilizing p21 mRNA (an ARE-containing transcript) and increasing p21 protein; this increased protein binding to CDE/CHR promoter sites of p21 target genes, repressing key G2/M phase genes, and increasing the proportion of cells in G2/M. NO• coordinates a highly integrated program of cell cycle arrest that regulates a large number of genes, but does not require signaling through cGMP. In humans, antiproliferative effects of NO• may rely substantially on cGMP-independent mechanisms. Stress kinase signaling and alterations in mRNA stability appear to be major pathways by which NO• regulates the transcriptome.
Quitting Smoking During Pregnancy and Birth Outcomes: Evidence of Gains Following Cessation by Third Trimester

Background: Research has clearly shown that babies born to smokers are significantly smaller at birth than those born to non-smokers. Programs exist to assist pregnant women in their efforts to quit smoking. While some of these interventions are effective in reducing smoking rates, less is known about whether birth outcomes are significantly improved for pregnancy quitters, especially those who quit later in pregnancy.
A study of low noise JFETs exposed to large doses of gamma-rays and neutrons

The monolithic process has proved able to retain the radiation hardness characteristics of discrete JFETs (junction field-effect transistors) up to 1 MGy (100 Mrad) of /sup 60/Co gamma rays. Neutron irradiation tests on discrete devices confirm that Si JFETs show very moderate damage up to 10/sup 13/ Ncm/sup -2/. In comparative tests Si JFET preamplifiers have been irradiated up to 600 kGy (60 Mrad) of gamma rays and up to 4*10/sup 14/ Ncm/sup -2/. The preamplifiers were able to withstand the tests and have shown less radiation sensitivity than GaAs MESFET preamplifiers in the region of peaking times longer than approximately=40 ns. The results are of interest in connection with the survival of front-end electronics for hadron collider experiments which may be subject to in excess of 30 Mrad of ionizing radiation and 10/sup 14/ Ncm/sup -2/ over a 10-year period. >
Disciplinary Foundations for Solving Interdisciplinary Scientific Problems.

Problem-solving has been one of the major strands in science education research. But much of the problem-solving research has been conducted on discipline-based contexts; little research has been done on how students, especially individuals, solve interdisciplinary problems. To understand how individuals reason about interdisciplinary problems, we conducted an interview study with 16 graduate students coming from a variety of disciplinary backgrounds. During the interviews, we asked participants to solve two interdisciplinary science problems on the topic of osmosis. We investigated participants’ problem reasoning processes and probed in their attitudes toward general interdisciplinary approach and specific interdisciplinary problems. Through a careful inductive content analysis of their responses, we studied how disciplinary, cognitive, and affective factors influenced their interdisciplinary problems-solving. We found that participants’ prior discipline-based science learning experiences had both positi...
Realization of high performance doped-channel MISFETs in highly strained AlGaAs/InGaAs/AlGaAs based quantum wells

Doped channel metal-insulator-semiconductor field effect transistors (DC-MISFETs) in the highly strained AlxGa1-xAs/ In0.26Ga0.74As/AlyGa1-yAs (0<x, y≤1.0) and ((AlAs)m(GaAs)n)/In0.26Ga0.74As/( (AlAs)p (GaAs)q) single quantum wells grown via MBE on GaAs (100) substrates have been examined with a view towards improved performance via control of growth using RHEED behavior of static and dynamic surfaces. Breakdown voltages over 20 V and over 40 V have been realized in structures containing AlGaAs alloy and equivalent Al content short period superlattice (SPSL) barriers, respectively. Low gate leakage currents and output conductance as low as 150 μS/mm have been realized. Increasing the In content to 30% and using heavy Si doping in the well, DC-MISFETs containing SPSL barriers have yielded drain currents of 1.2 A/mm and breakdown voltages of ∼10 V.
Predictors and Parameters of Resilience to Loss: Toward an Individual Differences Model

Although there is marked variation in how people cope with interpersonal loss, there is growing recognition that most people manage this extremely stressful experience with minimal to no impact on their daily functioning (G. A. Bonanno, 2004). What gives rise to this resilient capacity? In this paper, we provide an operational definition of resilience as a specific trajectory of psychological outcome and describe how the resilient trajectory differs from other trajectories of response to loss. We review recent data on individual differences in resilience to loss, including self-enhancing biases, repressive coping, a priori beliefs, identity continuity and complexity, dismissive attachment, positive emotions, and comfort from positive memories. We integrate these individual differences in a hypothesized model of resilience, focusing on their role in appraisal processes and the use of social resources. We conclude by considering potential cultural constraints on resilience and future research directions.
Frequency and Types of Foods Advertised on Saturday Morning and Weekday Afternoon English- and Spanish-Language American Television Programs

Abstract Objective To describe food advertised on networks serving children and youth, and to compare ads on English-language networks with ads on Spanish networks. Design Analysis of television food advertisements appearing on Saturday morning and weekday afternoons in 2005-2006. A random sample of 1,130 advertisements appearing on 12 networks catering to Spanish-language, children, youth, Black youth, and general audiences were analyzed. Main Outcome Measures Each advertisement was coded for the nature of the item promoted, the selling propositions used, and any nutritional claims made. Analysis Cross-tabulations using Fisher's exact test ( P Results One-fifth of commercials were for food. Food ads were especially prevalent on Saturday programs and children's networks. Seventy percent of food ads were for items high in sugar or fat. More than one fourth of food advertisements were for fast-food restaurants, which were especially common on MTV and Spanish-language networks. Ads for fruits and vegetables were rare (1.7%). One nutrition-related public service announcement was found for every 63 food ads. Conclusions and Implications Food advertisements continue to promote less-healthful items. Until marketing of high calorie, low-nutrient food to children is restricted, education and media literacy remain the best strategies for mitigating advertising effects.
Revision of Trillium subgenus Phyllantherum (Liliaceae)

A taxonomic revision, based mainly on morphological and distributional criteria, is presented for all taxa ofTrillium subgen.Phyllantherum Raf., which is characterized by sessile flowers. The 22 species recognized as valid include 17 morpho-geographical species in the eastern United States and five in the northwestern United States and California. These species form three morphological alliances that are characterized informally as “species groups.” All the taxa are described, and a key to species and varieties is provided. Five new species are described:Trillium decipiens, T. reliquum, T. foetidissimum, T. albidum, and T. kurabayashii; and a new status,T. angustipetalum (Torrey) Freeman, based onT. sessile var.angustipetalum Torrey, is proposed. Six new flower color forms are described:T. reliquum f. luteum, T. stamineum f. Iuteum, T. maculatumF. luteum, T. maculatum f. simulans, T. foetidissimum f. luteum, and T. cuneatum f. luteum. County distribution maps are included for all species and varieties, and an annotated synonymy is presented for each taxon.
Magnesium Treatment Of Torsade de Pointes—A Case Report:

An eighty-one-year-old woman received quinidine in order to convert atrial fibrillation to a sinus rhythm. The patient developed a prolonged QT interval on the EKG, as well as episodes of torsade de pointes. With the administration of intravenous magnesium sulfate, the abnormal rhythm was suppressed within minutes. Thus, magnesium should be the first drug used in patients with torsade de pointes and prolonged QT interval on the electrocardiogram.
Repetitive transcranial magnetic stimulation treats postpartum depression.

Background Postpartum depression (PPD) is a prevalent illness, affecting 10-15% of new mothers. PPD is the most common complication of childbirth and is a significant public health concern. It is known to adversely impact maternal-infant bonding, childrearing practices, and can lead to suicide and infanticide. The current treatment approaches to PPD are suboptimal. Many mothers are reluctant to take medication because of concerns about side effects or exposure of their newborn infant through breastfeeding. The specific aims of this study were to (1) examine acute treatment effectiveness, (2) examine response durability, and (3) assess an effect of repetitive transcranial magnetic stimulation (rTMS) on maternal bonding. Methods Nine antidepressant-free women with PPD were given 20 rTMS treatments over 4 weeks (10 Hz, 120% motor threshold, left dorsolateral prefrontal cortex). Multiple characteristics were assessed at baseline and throughout treatment. Duration of effect was assessed at 30 days, 3 months and 6 months posttreatment. Results Friedman's tests were conducted on Hamilton Rating Scale for Depression-24 item (HRSD-24), Edinburgh Postnatal Depression Scale (EPDS), Inventory of Depressive Symptomatology-Self-Report (IDS-SR) and Clinical Global Impressions-Severity (CGI-S) scores to compare performances at four time points (baseline, end of Week 2, end of Week 4, and 180-day follow-up). Overall, these results revealed a significant reduction in depressive symptoms by the end of Week 2 of treatment. Analyses yielded a medium effect size (r = 0.68) on the primary outcome variable (HRSD-24). Of note, all nine patients remained in treatment for the complete 4 weeks, did not miss any treatment sessions and eight participants achieved remission of symptoms, defined as a HRSD Conclusions Our results demonstrate promising results for the use of rTMS in the treatment of PPD. Further randomized, sham-controlled studies need to be completed.
Distance and Intraindustry Trade

This paper provides evidence on the importance of geographical distance by investigating the relationship between distance and the share of two-way trade in total trade. Findings are not consistent with the widely held view that intraindustry trade (IIT) falls off rapidly across the entire distance scale. Distance is found to exert a decreasingly positive effect on the IIT share. U.S. trade with Japan and major industrial nations in Western Europe heavily influences this pattern. Two-way trade is not as distance sensitive as previously thought. It is important to understand how geographical distance affects IIT because economic integration is more valuable when it allows countries to achieve greater specialization within the same industry. The insensitivity of the IIT share to geographical distance suggests distance may not exert a major influence on the optimal degree of regionalization for industrial nations.
Lack of benefit of concurrent chemotherapy in patients with cervical cancer and negative lymph nodes by FDG-PET

Abstract Purpose To compare the outcome of patients with cervical cancer and negative lymph nodes by fluorodeoxyglucose-positron emission tomography (FDG-PET) treated with irradiation (RT) and concurrent chemotherapy or RT alone. Methods and materials This was a prospective data registry of 65 patients with cervical cancer and negative lymph nodes by whole-body FDG-PET. The tumor stage was IB2 in 11, IIB in 37, and IIIB in 17 patients. RT alone was administered to 15 and RT with concurrent weekly cisplatin to 50 patients. Results The 5-year overall survival estimate was 85% with RT and 81% with RT and concurrent chemotherapy ( p = 0.91). The corresponding 5-year cause-specific survival estimates were 78% and 74% ( p = 0.98). The differences in the sites of recurrence (pelvis vs. distant metastasis) were not statistically significant between the two groups ( p = 0.77). A Cox proportional hazards model of survival outcome did not identify chemotherapy, overall treatment time, or radiation dose as statistically significant prognostic factors. Severe complications included one rectovaginal fistula, one rectal stricture requiring colostomy (both in the concurrent chemotherapy group), and one death from chemotherapy-related complications. Conclusion Irradiation with concurrent cisplatin was not advantageous compared with RT alone in patients with negative lymph nodes on FDG-PET.
The glass gene encodes a zinc-finger protein required by Drosophila photoreceptor cells

Null mutations of glass specifically remove photoreceptor cells, leaving other cell types intact. We have isolated the glass gene and have shown that its transcript encodes a putative protein of 604 amino acids with five zinc-fingers. The glass product may be a transcription factor required for the development of a single neuronal cell type.
Moisture effect on the storage, handling and flow properties of poultry litter.

Abstract Poultry litter, a combination of accumulated chicken manure, feathers and bedding materials, is a potential feedstock for bioenergy and other value-added applications. The effect of moisture on the physical properties, equilibrium moisture relations, flow properties and wall friction characteristics of poultry litter were measured. Poultry litter densities (bulk, particle and tap) reduced and compressibility increased with increase in moisture content. The fit of the GAB equation to poultry litter equilibrium moisture isotherm at 25 °C indicated that the monolayer moisture content for poultry litter is 5.5% (wb). Increasing the moisture content of the poultry litter reduced its flowability from easy flowing (flow index of 6.4) at moisture content of 10.3% (wb) to very cohesive (non-flowing) (flow index of 1.9) at moisture content of 30.9% (wb). Flow on a stainless steel surface was improved when the surface was mirror-finished or galvanized coated.
Determining error bars in measurements of ultrashort laser pulses

We present a simple and automatic method for determining the uncertainty in the retrieved intensity and phase versus time (and frequency) due to noise in a frequency-resolved optical-gating trace, independent of noise source. It uses the “bootstrap” statistical method and also yields an automated method for phase blanking (omitting the phase when the intensity is too low to determine it).
On Masters and Apprentices in Physical Education

This paper discusses the impact of the mentoring role of faculty on fostering a quality educational experience for graduate students. Although potentially significant graduate students naturally gravitate to work with significant faculty, it is the mentoring role of the advisor that allows the student's potential to be realized. Clues to the impact of this mentoring role are gleaned from Zuckerman's (1977) analysis of American Nobel Prize laureates. To promote a quality advisor–student relationship, departments need to look beyond the student and considerations of the norms and regulations of entrance and ongoing program criteria. One necessary and very significant precursor will be the presence of quality faculty.
Perinatal galactose metabolism

Galactose is a major nutrient in normal newborn infants and serves as a substrate for energy production and fuel storage and a regulator of carbohydrate assimilation. Inborn errors of galactose metabolism have contributed to our understanding of the potential toxicity of this carbohydrate. In addition to the classic acute manifestations of neonatal galactosemia, long-term follow-up of surviving patients have revealed unusual neurodevelopmental and reproductive problems. Many investigators have suggested that the newborn infant can utilize galactose better than adults and that neonatal galactose assimilation exceeds that of glucose. Galactose may be an excellent substitute for glucose among hyperinsulinemic infants of diabetic mothers or premature infants with glucose intolerance. However, until further investigations are performed to define the role of galactose in newborn nutrition and to determine its potential toxicity, galactose should not be used as the primary carbohydrate in sick newborn infants.
Simultaneous measurements of cardiac output by thermodilution, esophageal Doppler, and electrical impedance in anesthetized patients.

Abstract Simultaneous intraoperative measurements of cardiac output were obtained in nine patients with transesophageal Doppler, transthoracic impedance, and pulmonary artery thermodilution techniques to evaluate the utility of the noninvasive methods. Pairs of noninvasive and thermodilution measurements were obtained 25 times with transesophageal Doppler and 58 times with transthoracic impedance. Correlation of the noninvasive measurements with thermodilution was poor, with r = 0.43 for transthoracic impedance and r = .68 for transesophageal Doppler. The average difference between the noninvasive and the thermodilution values was −0.4 ± 1.4 L/min (mean ± SDI and −0.1 ± 1.6 L/min for impedance and Doppler, respectively. Changes in cardiac output at sequential time points as measured by thermodilution were predicted with 95% confidence only when a change of >4 L/min was observed by transesophageal Doppler or >8 L/min was observed by transthoracic impedance. Therefore, it is concluded that neither noninvasive technique reliably estimated cardiac output as determined by thermodilution, and neither tracked trends.
A linear time-invariant model for solid-phase diffusion in physics-based lithium ion cell models

Abstract Physics-based lithium ion models are widely used to predict the electrochemical behavior of lithium ion cells. The implementation of such a model typically requires solving a diffusion problem in solid particles. A linear time-invariant (LTI) model is proposed for the solid-phase diffusion problem. This LTI model can be used for spherical and non-spherical particles. For spherical particles, results from using the LTI model are compared with those from solving full diffusion equation, and excellent agreement is achieved. The LTI model solves only a few equations, and thus it runs much faster than the model solving the full diffusion equation. Impact of particle shapes on the electrochemical behavior is investigated after the model is validated.
X-ray photoelectron spectra of iron complexes: Correlation of iron 2p satellite intensity with complex spin state

Abstract Metal and ligand core-level spectra have been obtained for 36 iron complexes which possess a variety of ligands including carbonyl, nitrosyl, triphenylphosphine,o-phenylenebis(dimethylarsine), halides and pseudohalides. Formal metal oxidation states range from − 1 to + 3, and complex spin states represented in the series include 0, 1 2 , 3 2 , 2 and 5 2 . A clear correlation between complex spin state and satellite intensity in the Fe 2p spectra is found. The satellite intensities observed experimentally are in approximate quantitative accord with those predicted by a “spin flipping” model. Although the present analysis does not provide a definitive choice between the “sudden approximation” and “spin flipping” models, the agreement between experimental satellite intensities and the intensities predicted by the “spin flipping” model suggests that such a mechanism can be important in the satellite process.
Unusual intron in the immunoglobulin domain of the newly isolated murine CD4 (L3T4) gene.

The T-cell surface glycoprotein, CD4, is expressed predominantly on helper T cells and is thought to play a major role in cell–cell interactions1–5. Monoclonal antibodies against CD4 have been shown to block numerous T-cell functions1,3,4; moreover, recent results suggest that the CD4 molecule may be involved in transmembrane signal transduction6,7. The human CD4 glycoprotein has also been shown to form at least part of the receptor for the AIDS virus, HIV-1 (refs 8–10). Elucidation of the functions of CD4 will be facilitated by the ability to manipulate the protein by genetic means. Because the mouse system is well suited for a variety of functional studies, we have isolated, sequenced and expressed cDNA clones encoding the murine CD4 (L3T4) glycoprotein. Comparison of the mouse and human CD4 sequences reveals striking evolutionary conservation of the cytoplasmic domain, suggesting that this region is essential for CD4 function. In addition, both the human and mouse CD4 gene contain a large intron in the coding region of the V-like domain. As no other members of the immunoglobulin gene superf amily have been shown to contain similarly placed introns, this finding may have important implications regarding the evolution of this gene family in particular and of introns in general.
Tropical montane forest ecotones : climate gradients, natural disturbance, and vegetation zonation in the Cordillera Central, Dominican Republic

Aim We examined relationships between climate–disturbance gradients and patterns of vegetation zonation and ecotones on a subtropical mountain range. Location The study was conducted on the windward slopes of the Cordillera Central, Dominican Republic, where cloud forest appears to shift in a narrow ecotone to monodominant forest of Pinus occidentalis. Methods Climate, disturbance and vegetation data were collected over the elevation range 1100–3100 m and in 50 paired plots along the ecotone. Aerial photographs were georeferenced to a high-resolution digital elevation model in order to enable the analysis of landscape-scale patterns of the ecotone. Results A Shipley–Keddy test detected discrete compositional ecotones at 2200 and 2500 m; the distributions of tree species at lower elevations were continuous. The elevation of the ecotone determined with aerial photographs was fairly consistent, namely ± 164 m (SD) over its 124-km length, but it exhibited significant landscape variation, occurring at a lower elevation in a partially leeward, western zone. The ecotone also occurred significantly lower on ridges than it did in drainage gullies. Ecotone forest structure and composition differed markedly between paired plots. In pine paired plots, the canopy height was 1.7 times higher and the basal area of non-pine species was 6 times lower than in the cloud forest directly below. Fire evidence was ubiquitous in the pine forest but rare in the abutting cloud forest. Mesoclimate changed discontinuously around the elevation of the ecotone: humidity and cloud formation decreased markedly, and frost frequency increased exponentially. Main conclusions The discreteness of the ecotone was produced primarily by fire. The elevational consistency of the ecotone, however, resulted from the overarching influence of mesoclimate on the elevational patterns of fire occurrence. Declining temperature and precipitation combine with the trade-wind inversion to create a narrow zone where high-elevation fires extinguish, enabling fire-sensitive and fire-tolerant taxa to abut. Once established, mesotopography and contrasting vegetation physiognomy probably reinforce this boundary through feedbacks on microenvironment and fire likelihood. The prominence of the pine in this study – and of temperate and fire-tolerant taxa in subtropical montane forests in general – highlights the importance of climate-disturbance–biogeography interactions in ecotone formation, particularly where fire mediates a dynamic between climate and vegetation.
Cyclic Adenonosine Monophosphate does Not Affect the Stability of the Messenger Ribonucleic Acid for Tyrosine Aminotransferase in Cultured Hepatoma Cells

Cyclic AMP has been shown to stimulate synthesis of tyrosine aminotransferase (L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) by increasing the amount of its mRNA through an increase in initiation of transcription. However, cAMP also has posttranscriptional effects on the enzyme's synthesis, as evidenced by the 4- to 5-fold enhanced decline seen when cultured hepatoma cells are exposed to cAMP and transcription is inhibited. As a direct test of the possibility that cAMP exerts this effect by destabilizing the mRNA for tyrosine aminotransferase, we analyzed the rate of decay of the mRNA using the transcriptional inhibitor 5,6-dichlororibofuranosylbenzimidazole, Northern blot analysis, and an internal standard consisting of prelabeled rRNA. It was found that the half-life of the mRNA (2.0 +/- 0.2 h) was not changed by treatment of cultured hepatoma cells under conditions which increase intracellular cAMP levels. These mRNA half-life values were not significantly different from the decline in the rate of synthesis of the enzyme after induction in dexamethasone-treated cells. We conclude that cAMP does not affect the stability of the mRNA for tyrosine aminotransferase and discuss other possible explanations for the paradoxical effect of cAMP on deinduction of this enzyme.
Regulation of Yersinia Protein Kinase A (YpkA) Kinase Activity by Multisite Autophosphorylation and Identification of an N-terminal Substrate-binding Domain in YpkA

The serine/threonine protein kinase YpkA is an essential virulence factor produced by pathogenic Yersinia species. YpkA is delivered into host mammalian cells via a type III secretion system and localizes to the inner side of the plasma membrane. We have previously shown that YpkA binds to and phosphorylates the α subunit of the heterotrimeric G protein complex, Gαq, resulting in inhibition of Gαq signaling. To identify residues in YpkA involved in substrate binding activity we generated GFP-YpkA N-terminal deletion mutants and performed coimmunoprecipitation experiments. We located a substrate-binding domain on amino acids 40–49 of YpkA, which lies within the previously identified membrane localization domain on YpkA. Deletion of amino acids 40–49 on YpkA interfered with substrate binding, substrate phosphorylation and substrate inhibition. Autophosphorylation regulates the kinase activity of YpkA. To dissect the mechanism by which YpkA transmits signals, we performed nano liquid chromatography coupled to tandem mass spectrometry to map in vivo phosphorylation sites. Multiple serine phosphorylation sites were identified in the secretion/translocation region, kinase domain, and C-terminal region of YpkA. Using site-directed mutagenesis we generated multiple YpkA constructs harboring specific serine to alanine point mutations. Our results demonstrate that multiple autophosphorylation sites within the N terminus regulate YpkA kinase activation, whereas mutation of serine to alanine within the C terminus of YpkA had no effect on kinase activity. YpkA autophosphorylation on multiple sites may be a strategy used by pathogenic Yersinia to prevent inactivation of this important virulence protein by host proteins.
Balancing Solvation and Intramolecular Interactions: Toward a Consistent Generalized Born Force Field

The efficient and accurate characterization of solvent effects is a key element in the theoretical and computational study of biological problems. Implicit solvent models, particularly generalized ...
The impact of recent advances in immunology and cancer therapy on nuclear medicine

The explosive expansion of knowledge in immunology in recent decades has already affected the research and practice of nuclear medicine in several ways. New hematopoietic cells have been isolated and their functions discovered, including hematopoietic stem cells and dendritic cells (DCs). Many new humeral factors have been found that have potent effects on cells, including cytokines, growth factors, and specialized proteins. Radiolabeled compounds are needed to follow the pharmacodynamics of the humeral factors and to follow the migration of mobile cells in animals and humans. In this article, only DCs, cytokines, and growth factors used clinically are discussed. DCs are essential for defense against infectious diseases. Autologous DCs cultured for a week and pulsed with tumor antigens have already proved highly immunogenic compared with other methods for activating cytotoxic T cells, and preliminary studies suggest that DCs are more potent for tumor cell killing than monoclonal antibodies. DCs, unfortunately, also play an important role in causing certain human diseases. In allograft transplants, residual donor DCs are responsible for the cellular rejection; if they could be eliminated, rejection could be prevented. These cells are also detrimental in rheumatoid arthritis, other autoimmune diseases, asthma, and chronic obstructive pulmonary disease. Cytokines such as interleukin-2 and such growth factors as granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor, administered to patients with malignancies to alleviate the leukopenia of chemotherapy agents, frequently alter the tissue distribution of radiopharmaceuticals; these alterations may be confused with disease.
Androgen Receptor Phosphorylation and Activity Are Regulated by an Association with Protein Phosphatase 1

Androgen receptor (AR) is phosphorylated at multiple sites in response to ligand binding, but the functional consequences and mechanisms regulating AR phosphorylation remain to be established. We observed initially that okadaic acid, an inhibitor of the major PPP family serine/threonine phosphatases PP2A and protein phosphatase 1 (PP1), had cell type-dependent effects on AR expression. More specific inhibitors of PP2A (fostriecin) and PP1 (tautomycin and siRNA against the PP1α catalytic subunit) demonstrated that PP1 and protein phosphatase 2A had opposite effects on AR protein and transcriptional activity. PP1 inhibition enhanced proteasome-mediated AR degradation, while PP1α overexpression increased AR expression and markedly enhanced AR transcriptional activity. Coprecipitation experiments demonstrated an AR-PP1 interaction, while immunofluorescence and nuclear-cytoplasmic fractionation showed androgen-stimulated nuclear translocation of both AR and PP1 in prostate cancer cells. Studies with phosphospecific AR antibodies showed that PP1 inhibition dramatically increased phosphorylation of Ser-650, a site in the AR hinge region shown to mediate nuclear export. Significantly, PP1 inhibition caused a marked decrease in nuclear localization of the wild-type AR, but did not alter total or nuclear levels of a S650A mutant AR. These findings reveal a critical role of PP1 in regulating AR protein stability and nuclear localization through dephosphorylation of Ser-650. Moreover, AR may function as a PP1 regulatory subunit and mediate PP1 recruitment to chromatin, where it can modulate transcription and splicing.
Efficient computation of the maximum a posteriori path and parameter estimation in integrate-and-fire and more general state-space models

A number of important data analysis problems in neuroscience can be solved using state-space models. In this article, we describe fast methods for computing the exact maximum a posteriori (MAP) path of the hidden state variable in these models, given spike train observations. If the state transition density is log-concave and the observation model satisfies certain standard assumptions, then the optimization problem is strictly concave and can be solved rapidly with Newton---Raphson methods, because the Hessian of the loglikelihood is block tridiagonal. We can further exploit this block-tridiagonal structure to develop efficient parameter estimation methods for these models. We describe applications of this approach to neural decoding problems, with a focus on the classic integrate-and-fire model as a key example.
Enhanced holographic image intensification in BaTiO(3) photoelectrets.

We report an enhanced holographic image amplification gain of over 24,000 at a wavelength of 514.5 nm by using a BaTiO3 photoelectret. The energy-transfer efficiency and amplification factor are found to depend on critical polarization conditions of the photoelectret, the beam-mixing geometries, and the intensity ratios between the reference and the object beams. The results obtained by this new technique show significant improvement over corresponding values reported previously.
Metabolic effects of stress mediators on cultured hepatocytes.

Stress mediators play a major role in inducing the hypermetabolic stress state in the liver after major injuries. The majority of studies on the effect of mediators on hepatocytes have focused on single factor effects or on the effect of very complex additives (e. g., serum), and there are no reports which have rigorously identified specific interactions between stress mediators. We used a factorial design experimental approach to evaluate the effects of a four to five day exposure to hormone (glucagon, hydrocortisone, and epinephrine) and cytokine [tumor necrosis factor-alpha (TNF-alpha) interleukin-1beta (IL-1beta) and interleukin-6 (IL-6)] stress mediators on stable cultures of rat hepatocytes. Both individual-factor effects and two factor interactions on the metabolism of urea, glucose, lactate, ketone bodies, albumin, and fibrinogen were evaluated. The cultured hepatocyte model exhibited physiologic responses to the applied stress mediators. While hydrocortisone and epinephrine had no effect, glucagon induced an increase in glucose and urea synthesis. Interleukin-6 increased fibrinogen and decreased albumin production. Furthermore, IL-6 and glucagon caused an increase in the ketone-body ratio (KBR = [acetoacetate]/[beta-hydroxybutyrate]), which is in equilibrium with the intramitochondrial NAD+/NADH. Tumor necrosis factor-alpha and IL-1beta, on the other hand, decreased the KBR. An important two-factor interaction between IL-1beta and IL-6 was identified, namely that IL-1beta effectively negates the positive effect of IL-6 on the KBR when both are present. These results provide further understanding of the effect of stress mediators on hepatic function and metabolism. These effects may have important implications in the pathogenesis of progressive organ dysfunction which often follows prolonged inflammatory states triggered by major injuries.
Melatonin receptor-mediated inhibition of cyclic AMP accumulation in chick retinal cell cultures.

: Melatonin receptors were characterized in cultured neurons and photoreceptors prepared from chick embryo retina. Cultured cells contained high-affinity 2-[125I]iodomelatonin binding sites (KD = 41.6 pM), similar to those in intact retina. The effects of melatonin and related indoles on cyclic AMP accumulation were examined. Melatonin (10−7M) had no effect on basal or K+-stimulated cyclic AMP accumulation, but inhibited forskolin-stimulated cyclic AMP accumulation by approximately 50%. Melatonin inhibited forskolin-stimulated cyclic AMP accumulation in the presence or absence of the cyclic nucleotide phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine, suggesting an effect on cyclic AMP synthesis rather than degradation. Half-maximal inhibition was observed at 5.9 × 10−10M melatonin. The relative order of potency among melatonin analogues was 2-iodomelatonin > melatonin ≈ 6-chloromelatonin ≥ 6-hydroxymelatonin > N-acetylserotonin ≈ 5-methoxytryptophol > serotonin. The EC50 value for inhibition of cyclic AMP accumulation by 2-iodomelatonin (36.7 pM) was comparable to the KD value for binding of the radioligand, suggesting that the binding sites represent functional receptors. The inhibitory effect of melatonin was antagonized by the putative melatonin antagonists luzindole, N-acetyltryptamine, and N-(2,4-dinitrophenyl)-5-methoxytryptamine, with estimated KB values of 0.12, 0.17, and 1 µM, respectively. At a concentration of 10 µM, N-(2,4-dinitrophenyl)-5-methoxytryptamine significantly inhibited forskolin-stimulated cyclic AMP accumulation when added alone; at 30 µM, luzindole and N-acetyltryptamine also had significant inhibitory effects. The inhibitory effect of melatonin was blocked by pretreatment with pertussis toxin. The results of this study indicate that melatonin receptors on retinal cells are coupled via inhibitory G proteins to cyclic AMP accumulation. Thus, some of the effects of melatonin on retinal physiology may be related to regulation of cyclic nucleotide metabolism.
On the stochastic theory of compartments: Solution for n -compartment systems with irreversible, time-dependent transition probabilities

The bivariate distribution of a two-compartment stochastic system with irreversible, time-dependent transition probabilities is obtained for any point in time. The mean and variance of the number of particles in any compartment and the covariance between the number of particles in each of the two compartments are exhibited and compared to existing results. The two-compartment system is then generalized to ann-compartment catenary and to ann-compartment mammillary system. The multivariate distributions of these two systems are obtained under two sets of initial conditions: (1) the initial distribution is known; and (2) the number of particles in each compartment of the system at timet=0 is determined. The moments of these distributions are also produced and compared with existing results.