cssi/SciSciGPT-SciSciNet huggingface dataset:
Alkaline Isomerization of Oxidized Cytochrome c EQUILIBRIUM AND KINETIC MEASUREMENTS

Equilibrium and kinetic studies of the isomerization of horse heart ferricytochrome c at alkaline pH have been carried out using difference spectroscopy and stopped flow techniques. The minimal reaction scheme is: [see PDF for equation] where CH and C are species of ferricytochrome c which exhibit a 695 nm absorbance band, and NC (no color) is a form without this band; the oxidation-reduction potentials of CH and NC differ significantly. The values of the constants in this scheme were determined at 25° except for the oxidation and reduction rate constants, which were determined at 22°. The pH dependence of the observed rate constant for the conformational changes was measured as the change in the 695 nm band absorbance and as the release and uptake of hydrogen ions. From this it was calculated that the ionizing group in the scheme above has an apparent pK of 11.0 ± 0.1 at 25°. The conformation equilibrium constant, Kc, defined as κf/κb, was found to be 125 ± 36 at 25°. An over-all pK of 9.0 was calculated from the product of the equilibrium constants, in agreement with the over-all pK of 9.0 determined from the pH dependence of the 695 nm band at equilibrium. Spectrophotometric measurements at 243 nm indicate that tyrosine is not the ionizing group with an apparent pK of 11. It is suggested that the difference in oxidation-reduction potential and the absorbance band at 695 nm arises by substituting the sulfur of Met-80 as one of the ligands of the iron porphyrin in CH by the e-amino group of Lys-79 in NC. This suggestion, consistent with structural information, is accessible to experimental verification.
Safety and mechanism of appetite suppression by a novel hydroxycitric acid extract (HCA-SX)

A growing body of evidence demonstrates the efficacy of Garcinia cambogia-derived natural (-)-hydroxycitric acid (HCA) in weight management by curbing appetite and inhibiting body fat biosynthesis. However, the exact mechanism of action of this novel phytopharmaceutical has yet to be fully understood. In a previous study, we showed that in the rat brain cortex a novel HCA extract (HCA-SX, Super CitriMax) increases the release/availability of radiolabeled 5-hydroxytryptamine or serotonin ([3H]-5-HT), a neurotransmitter implicated in the regulation of eating behavior and appetite control. The aim of the present study was 2-fold: (a) to determine the effect of HCA-SX on 5-HT uptake in rat brain cortex in vitro; and (b) to evaluate the safety of HCA-SX in vivo. Isolated rat brain cortex slices were incubated in oxygenated Krebs solution for 20 min and transferred to buffer solutions containing [3H]-5-HT for different time intervals. In some experiments, tissues were exposed to HCA-SX (10 microM - 1 mM) and the serotonin receptor reuptake inhibitors (SRRI) fluoxetine (100 microM) plus clomipramine (10 microM). Uptake of [3H]-5-HT was expressed as d.p.m./mg wet weight. A time-dependent uptake of [3H]-5-HT occurred in cortical slices reaching a maximum at 60 min. HCA-SX, and fluoxetine plus clomipramine inhibited the time-dependent uptake of [3H]-5-HT. At 90 min, HCA-SX (300 microM) caused a 20% decrease, whereas fluoxetine plus clomipramine inhibited [3H]-5-HT uptake by 30%. In safety studies, acute oral toxicity, acute dermal toxicity, primary dermal irritation and primary eye irritation, were conducted in animals using various doses of HCA-SX. Results indicate that the LD50 of HCA-SX is greater than 5,000 mg/kg when administered once orally via gastric intubation to fasted male and female Albino rats. No gross toxicological findings were observed under the experimental conditions. Taken together, these in vivo toxicological studies demonstrate that HCA-SX is a safe, natural supplement under the conditions it was tested. Furthermore, HCA-SX can inhibit [3H]-5-HT uptake (and also increase 5-HT availability) in isolated rat brain cortical slices in a manner similar to that of SRRIs, and thus may prove beneficial in controlling appetite, as well as treatment of depression, insomnia, migraine headaches and other serotonin-deficient conditions.
Pinning size effects in critical currents of superconducting films

The thickness dependence of the critical current density Jc(d) in films due to the two-dimensional–three-dimensional (2D–3D) pinning crossover at low magnetic fields is addressed, taking into account the spatial correlation of pinning centres, the combined effect of bulk and surface pinning, and the effect of thermal fluctuations. The whole Jc(d) curve for both the 3D and 2D pinning regimes, and the crossover thickness dc are calculated using a dynamic approach for a random pinning potential characterized by the Gaussian correlation functions. It is shown that the spatial correlation of pinning centres can significantly increase dc as compared to uncorrelated point pins, and the competition between pinning and thermal fluctuations gives rise to a nonmonotonic dependence of Jc(d). The account of multiscale spatial correlations in a uniform pinning nanostructure can result in behaviour of Jc(d) similar to that observed on YBa2Cu3O7−δ. The ultimate limit of Jc is discussed.
Personal and Aggregate Unemployment and Psychological Symptoms

Four different types of individual-level unemployment experiences were studied in relation to psychological symptoms: (1) current unemployment following a recent involuntary job loss, (2) unemployment among students or homemakers, (3) reemployment after recent job loss, and (4) either voluntary or long-term (greater than 6 months) unemployment. Aggregate unemployment (the prevailing rate in the surveyed community) was also studied, both alone and in interaction with each of the four individual-level unemployment conditions. These five variables were each related positively to psychological symptoms, whether measured as a continuous variable or as a dichotomous variable simulating a case/non- case split, and controlling for the usual demographic variables and various other stressful life events. Little evidence was found for interactions of the unemployment conditions with aggregate unemployment or with potential moderators. A small panel study provided a partial longitudinal check for several of these cross-sectional findings. The findings are discussed in terms of public policy options.
Oxygen uptake and its relation to pH in a human salivary system during fermentation of glucose.

Abstract Oxygen consumption by the mixed bacteria in salivary sediment was examined in relation to the decrease in pH that occurs when glucose at different concentrations (2.8 mM–1.68 M) was fermented in 4 h incubations at 37°C. These experiments demonstrated that (i) the use of oxygen was extremely rapid, resulting in all cases in the P O 2 decreasing within 1–2 min from atmospheric P O 2 (approx. 20 kPa) to levels at or near zero; (ii) a period of about 30 min of reduced oxygen uptake consistently occurred after the initial PO 2 drop, so long as salivary supernatant was present and the pH was allowed to fall; (iii) except for 11.2 mM glucose, the PO 2 was kept at or near zero throughout each incubation with all glucose concentrations tested because of rapid oxygen consumption by the sediment bacteria—oxidizable substrates in the sediment and in added salivary supernatant contributed significantly to the prolonged oxygen depletion; (iv) the pH was important for determining the relative contributions of glucose and supernatant to the uptake of oxygen by the sediment bacteria and for observations (ii) and (iii). When the acids produced during aerobic degradation of glucose were tested for stimulation of oxygen uptake, l (+)lactic stimulated more rapid uptake than did d (−)lactic acid, whereas acetic and propionic acids showed none. These findings were in agreement with a metabolic scheme proposed earlier for aerobic degradation of glucose by the sediment microflora, and indicated where and how oxygen utilization might be involved in glucose fermentation.
Responses to Persons with AIDS: Fear of Contagion or Stigma?1

Recently it has been argued that responses to persons with Acquired Immune Deficiency Syndrome (AIDS) are more a function of the association of AIDS with homosexuality than they are concerns about contagion. This research provided a further test of these arguments using an experimental design in which the target disease's contagiousness and association with homosexuality were manipulated. The results indicated that willingness to interact with a disease victim was strongly related to the contagiousness of the disease but only weakly related to its association with homosexuality. These findings are in line with recent research on lay conceptions of physical illness and argue that avoidance of disease victims, including persons with AIDS, primarily reflects concerns over contracting the disease. The implications of these findings for lay illness conceptions and how lay people respond to disease victims are discussed.
Multiple antigenic peptides designed to structurally related Drosophila peptides.

Abstract Nichols, R., J. McCormick and I. Lim. Multiple antigenic peptides designed to structurally related Drosophila peptides.Peptides 18(1) 41–45, 1997.—We have isolated TDVDHVFLRFamide (DMS), FDDYGHMRFamide (DSK), and DPKQDFMRFamide from Drosophila melanogaster. These peptides, structurally related by a common C-terminus -XRFamide, where X = L or M, are encoded by three different genes. To determine cellular expression, we have generated antisera to multiple antigenic peptides and performed double-label immunofluorescence using antisera raised in the same species host animal. Our results indicate that DMS and DSK immunoreactive materials have unique, non-overlapping expression patterns, while DMS and DPKQDFMRFamide immunoreactive materials colocalize in two superior protocerebrum neurons, and DSK and DPKQDFMRFamide immunoreactive materials colocalize in one superior protocerebrum neuron, one subesophageal ganglion neuron, and three thoracic ganglia neurons.
Neutron inverse optics in layered materials

Neutron specular reflectivity data obtained with a new grazing angle neutron spectrometer (GANS) from a NiC/Ti-multilayer sample were analyzed and modeled for reconstructing the scattering length density profile as a periodic step potential for the layered material. There is some ambiguity in the results due to the uniqueness problem with missing phase information. For more complex layered materials, there is often insufficient knowledge about the layers to use modeling reconstruction without phase information. In the second part, we present a method in which this problem is solved for diffraction data from lipid multilayers: due to changes in chemistry (isomorphous heavy atom method) the phases are determined directly and therefore the density profile of the lipid bilayer can be uniquely determined.
The ‘Negative Argument’ in J. S. Mill's Utilitarianism

In her recent book On Liberty and Liberalism — The Case of John Stuart Mill, Gertrude Himmelfarb is temporarily annoyed at Mill's use of the “negative argument” in the opening pages of his Subjection of Women. “It is astonishing, at first reading,” Himmelfarb writes, “to find Mill devoting so much space to what is essentially a negative argument.” What Mill does in his introductory chapter to prove that “the legal subordination of one sex to the other — is wrong in itself, and now one of the chief hindrances to human improvement,” which “ought to be replaced by a principle of perfect equality, admitting no power or privilege on the one side, nor disability on the other,” is attack as strongly as he can the prejudicial nature of that subordination which had hardened into rigid and implacable legal barriers vastly inimical to that perfect equality Mill wanted to achieve. Here is a portion of Mill's summation of that legal subordination against which married women, in particular, had to contend:The wife is the actual bond-servant of her husband: no less so, as far as legal obligation goes, than slaves commonly so called. She vows a lifelong obedience to him at the altar, and is held to it all through her life by law …. She can do no act whatever but by his permission, at least tacit. She can acquire no property but for him; the instant it becomes hers, even if by inheritance, it becomes, ipso facto his … in regard to the children … they are by law his children. He alone has any legal rights over them. Not one act can she do towards or in relation to them, except by delegation from him. Even after he is dead she is not their legal guardian, unless he by will has made her so. . . . If she leaves her husband, she can take nothing with her, neither her children nor anything which is rightfully her own. If he chooses, he can compel her to return, by law, or by physical force; or he may content himself with seizing for his own use anything which she may earn, or which may be given to her by her relations.
Additive Effects on Si3n4 Oxidation/Volatilization in Water Vapor

Two commercially available additive-containing silicon nitride materials were exposed in four environments which range in severity from dry oxygen at 1 atm pressure, and low gas velocity to an actual turbine engine. Oxidation and volatilization kinetics were monitored at temperatures ranging from 1066 to 1400 C. The main purpose of this paper is to examine the surface oxide morphology resulting from the exposures. It was found that the material surface was enriched in rare earth silicate phases in combustion environments when compared to the oxides formed on materials exposed in dry oxygen. However, the in situ formation of rare earth disilicate phases offered little additional protection from the volatilization of silica observed in combustion environments. It was concluded that externally applied environmental barrier coatings are needed to protect additive-containing silicon nitride materials from volatilization reactions in combustion environments. Introduction Si3N4 is proposed for use as components, such as vanes, in turbine applications. Tens of thousands of hours of life are needed for both land-based turbines and aeropropulsion applications. Additive-containing SisN4 materials are
Limited effects of intravenous paracetamol on patent ductus arteriosus in very low birth weight infants with contraindications for ibuprofen or after ibuprofen failure

Finding the optimal pharmacological treatment of a patent ductus arteriosus (PDA) in preterm neonates remains challenging. There is a growing interest in paracetamol as a new drug for PDA closure. In this prospective observational cohort study, we evaluated the effectiveness of intravenous paracetamol in closing a PDA in very low birth weight infants with a hemodynamically significant PDA who either did not respond to ibuprofen or had a contraindication for ibuprofen. They received high-dose paracetamol therapy (15 mg/kg/6 h intravenous) for 3–7 days. Cardiac ultrasounds were performed before and 3 and 7 days after treatment. Thirty-three patients were included with a median gestational age of 251/7 weeks (IQR 1.66), a median birth weight of 750 g (IQR 327), and a median postnatal age of 14 days (IQR 12). Paracetamol was ineffective in 27/33 patients (82 %). Even more, after previous exposure to ibuprofen, this was even 100 %.
Cleavage of vinylic mercuric halides by aqueous acids

Isotope effects, general acid catalysis, and relative reactivities show that proton transfer to one of the unsaturated carbon atoms is rate determining for the acidolysis of unsaturated alkylmercuric halides. For compounds, R1R2CCHHgX, substitution of CH3 for H at R1 or R2 leads to an acceleration of a factor of ∼ 30. This relatively small acceleration, the relative facility of the reactions, and the magnitude of the Br− catalytic terms, suggests an olefin–mercuric halide complex as the product of the rate-determining step, rather than a simple carbonium ion. The Broonsted catalysis law is obeyed with a variety of carboxylic acids, giving an ∝ of 0.69 ± 0.04, but acids of other structures give substantially deviant catalytic coefficients, in a pattern similar to that generated by other A-SE2 reactions. The acetic acid catalytic coefficient is larger by a factor of 102 than that predicted if it were due to specific hydronium ion–general base catalysis instead of true general acid catalysis. The overall solvent isotope effect, kH/kD, is 2.55 ± 0.10. The competitive isotope effect, κH/κD, is 6.84 ± 0.06. Taken with a model in which the proton is transferred directly from the H3O+ unit of the aquated proton to the substrate, these are sufficient to successfully predict the rate at all intermediate isotopic compositions.
The relationship between the chemical structures and mutagenic specificities of the DNA lesions formed by chemical and physical mutagens

The mutagenic activities of radiation, alkylating agents, and aromatic amines and amides are examined from the perspective of relating the observed patterns of mutagenesis with the structures of the premutagenic DNA lesions. The general approach taken to establish such relationships has involved the construction of viral or plasmid genomes containing specific DNA adducts. The in vivo replication of such site-specifically modified genomes results in the induction of mutations, which are characterized by DNA sequencing. It is found that the mutation types that arise in these simple systems often match those occurring in tumors produced in mammals exposed intentionally or unintentionally to carcinogenic agents.
Cell-Free Supernatants from Probiotic Lactobacillus casei and Lactobacillus rhamnosus GG Decrease Colon Cancer Cell Invasion In Vitro

Probiotics have been shown to have a preventative role in colorectal carcinogenesis but research concerning their prophylactic potential in the later stages of colorectal cancer, specifically metastasis is limited. This study explored the potential of cell-free supernatants (CFS) from 2 probiotic Lactobacillus sp., Lactobacillus casei and Lactobacillus rhamnosus GG, to inhibit colon cancer cell invasion by influencing matrix metalloproteinase-9 (MMP-9) activity and levels of the tight junction protein zona occludens-1 (ZO-1) in cultured metastatic human colorectal carcinoma cells. HCT-116 cells were treated with CFS from L. casei, L. rhamnosus, or Bacteroides thetaiotaomicron (a gut commensal); or with uninoculated bacterial growth media. Treatment with CFS from both Lactobacillus sp. decreased colorectal cell invasion but treatment with CFS from B. thetaiotaomicron did not. CFS from both Lactobacillus sp. decreased MMP-9 and increased ZO-1 protein levels. L. rhamnosus CFS also lowered MMP-9 activity. To ...
Age related development of atherosclerotic plaque stress: A population-based finite-element analysis

BACKGROUND In order to identify those age-related factors in the development of coronary atherosclerosis that would affect the stability of the plaque system, we have developed idealized, finite-element, cross-sectional models of the arterial wall and associated lesions, derived from population-based data. METHODS The physical development and morphology of coronary plaques was documented in the Pathobiological Determinants of Atherosclerosis in Youth histological study. Using this database, finite-element analysis models were created for five age groups (15-19, 20-24, 25-29 and 30-34 years) and for the 25 largest lesions. Cosmos (Structural Research, Inc., Los Angeles, California, USA) was used to create and analyze the models. RESULTS The area of greatest stress shifted from the intima opposite the lesion in the 15-19 years age group to the edge of the cap and adjacent healthy tissue in the later age groups. Increasing age had a strong positive correlation with the shoulder stress level (r = 0.95) and the per cent stenosis correlated well with shoulder stress (r = 0.99, P < 0.002). Increasing the cap stiffness from a soft cap to a fibrous cap in the 30-34 year age group model resulted in a localized increase in shoulder surface stress by 10%. A calcified cap increased this shoulder surface stress by 30%. CONCLUSIONS This finite-element analysis of the population-based data shows that the increase in stress appears to be closely related to the impaired load-bearing capability of the lipid pool that develops with age. The shoulder area of the lesion has been shown to be the location of most of the plaque fractures.
The effect of delta-9-tetrahydrocannabinol on barbiturate withdrawal convulsions in the rat.

Abstract Rats were given increasing oral doses of sodium barbital over a four-week period until a daily dose of 400 mg/Kg was attained and continued for one week. Upon withdrawal from the barbital, the animals were found to be susceptible to sound-induced convulsive seizures. Dose-dependent seizure protection was provided by administration of delta-9-tetrahydrocannabinol (THC).
Consolidating theoretical results for weighted tardiness scheduling

We provide a theorem for 1||Σ wjTj, which specifies necessary and sufficient conditions for adjacent job pairs in an optimum schedule. This 'adjacency theorem' is compactly stated and a straightforward proof is provided. The theorem unifies the related literature and generalises three disparate earlier research findings into a single simple result. Also provided is a brief description of how the theorem could be usefully applied in a search algorithm for 1||Σ wjTj.
EVALUATING SELECTED PERCEPTIONS OF SCIENCE AND MATHEMATICS TEACHERS IN AN ALTERNATIVE CERTIFICATION PROGRAM

In 2003 the University of Missouri (with the aid of US National Science Foundation funding) initiated an alternative certification program (ACP) to address the well-documented need in the US for increasing the quantity and quality of mathematics and science teachers for the middle and secondary levels. Nationwide current certification programs do not provide the quality and quantity of mathematics and science teachers needed in schools. As a result most American states have begun to experiment with ACPs as a way to address the shortage of math and science teachers. To evaluate the success of this program, we collected data from ACP participants regarding perceived preparation, self efficacy, and outcome expectancy at three time points in the program. State standards for beginning teachers were used to construct a perceived preparation instrument. Analysis of data suggests that over time, ACP participants exhibited an increasingly positive view toward their preparation for classroom teaching, as well as increased self efficacy. However, there was little change in the students’ outcome expectancy over time. In this article we share details of the unique ACP program and we describe steps taken to collect and evaluate a project data set. Our work provides useful guidance to researchers and practitioners in the field of science and mathematics teacher education.
Dispersal of ash in the great Toba eruption, 75 ka

One of Earth9s largest known eruptions, the Toba eruption of 75 ka, erupted a minimum of 2800 km 3 of magma, of which at least 800 km 3 was deposited as ash fall. This ash may be entirely of coignimbrite origin and dispersed widely because of high drag coefficients on the predominantly bubble-wall shards. Shards of this shape are broken from the walls of spherical vesicles, which formed in high abundance in isotropic strain shadows near phenocrysts in this crystal-rich magma.
Transverse cerebellar diameter measurements in twin pregnancies and the effect of intrauterine growth retardation.

Abstract OBJECTIVES : Transverse cerebellar diameter measurements have been established for singleton but not twin pregnancies. In singleton pregnancies controversy exists on whether cerebellar growth is affected by intrauterine growth retardation. We undertook this retrospective study in twin pregnancies to establish a nomogram for the transverse cerebellar diameter in twins and to assess the effect of growth retardation on this measurement. STUDY DESIGN : A retrospective review was performed on 171 patients with twin pregnancies withreliable dating from 15 to 36 weeks' gestation who had been referred to our antenatal evaluation unit for routine ultrasonographic examination. Of the 342 fetuses, 322 were available for analysis and establishment of a nomogram for the transverse cerebellar diameter. Twenty-four twin, growth-retarded fetuses were analyzed separately. RESULTS : The transverse cerebellar diameter increased linearly with gestational age ( r = 0.94, p CONCLUSION : We suggest that intrauterine growth retardation may affect cerebellar growth in twins. (AmJ OBstet Gynecol 1992;167:982–5.)
Comparison of the effect of adenoviral delivery of three superoxide dismutase genes against hepatic ischemia-reperfusion injury.

The purpose of this study was to investigate the effectiveness of superoxide dismutase (SOD) overexpression in an acute model of hepatic oxidative stress. Oxidative stress was established using a warm ischemia-reperfusion model, where nearly 70% of the liver was made hypoxic by clamping the hepatic artery and a branch of the portal vein for 1 hr followed by restoration of blood flow. Animals were infected i.v. with 1 × 109 plaque-forming units (PFU) of adenovirus containing the transgene for cytosolic Cu/Zn-SOD (Ad.SOD1), mitochondrial Mn-SOD (Ad.SOD2), extracellular Cu/Zn-SOD (Ad.SOD3), or the bacterial reporter gene for β-galactosidase (Ad.lacZ) 3 days prior to experiments. Ad.SOD1 and Ad.SOD2 caused a three-fold increase in SOD expression and activity in liver compared to Ad.lacZ-treated control animals. Intravenous administration of Ad.SOD3 increased SOD activity slightly in serum but not in liver. Increases in serum transaminases and pathology due to ischemia-reperfusion were blunted by Ad.SOD1 and A...
Monitoring nutrient concentrations in Tampa Bay with MODIS images and machine learning models

This paper explores the spatiotemporal nutrient patterns in Tampa Bay, Florida with the aid of Moderate Resolution Imaging Spectroradiometer (MODIS) images and Genetic Programming (GP) models that are designed to link Total Phosphorus (TP) levels and remote sensing reflectance bands in aquatic environments. In-situ data were drawn from a local database to support the calibration and validation of the GP model. The GP models show the effective capacity to demonstrating the snapshots of spatiotemporal distributions of TP across the Bay, which helps to delineate the short-term seasonality effect and the global trend of TP in the coastal bay. The model output can provide informative reference for the establishment of contingency plans in treating nutrients-rich runoff.
The effect of prenatal alcohol, marijuana, and tobacco exposure on neonatal behavior

Abstract This prospective study investigated the effects of prenatal substance use on the behavior of full-term infants. Women were interviewed at the end of each trimester of pregnancy about their alcohol, marijuana, tobacco, and other drug use. Infants were assessed with the Neonatal Behavioral Assessment Scale (NBAS). Stepwise multiple regression analyses revealed that there were few effects of moderate prenatal alcohol, marijuana, or tobacco consumption on neonatal behavior, after controlling for important confounding variables.
The remarkable biology of pollen.

To reproduce, higher plants utilize a unique multicellular microorganism: the male gametophyte, or pollen grain. The independent lifetime of flowering plant gametophytes is greatly abbreviated compared to that of gametophytes of more primitive plants, yet the angiosperm pollen grain must be able to survive at least briefly free from the sporophytic plant and perform a number of specialized functions before fertilization is accomplished. Although the pollen grain is a rather simple twoor threecelled organism, cytogenetic and mutagenesis experiments indicate that higher plants make a significant investment in genetic material devoted to gametophyte production (Carlson, 1977; Birchler and Schwartz, 1979; Kindiger et al., 1991). Molecular studies identifying antherand pollen-specific genes support the notion that the construction of a functional male gametophyte requires a rather large pool of such genes (Kamalay and Goldberg, 1980; Willing and Mascarenhas, 1984; McCormick, 1991). This is not so surprising given the specialized structures, mechanisms for rapid growth, and cell-cell communication systems during pollen-pistil interactions that have evolved to allow for both the survival of the gametophyte free of the sporophyte and the efficient delivery of sperm to the embryo sac. Studies of certain aspects of the molecular mechanisms of gametophyte development and function have progressed very rapidly. Examples of these include the identification of cis-acting elements determining tissue-specific gene expression in pollen and tapetal cells (Ursin et al., 1989; Koltunow et al., 1990; McCormick et al., 1991) and of mechanisms of self-incompatibility in pollen-pistil interactions (McClure et al., 1989, 1990; Thorsness et al., 1991). The intent of this article is to focus on a few less well studied but intriguing aspects of pollen development and function, with an emphasis on pollen development in maize. For more general reviews of microsporogenesis, the reader is referred to Giles and Prakash (1987) and Mascarenhas (1989). For recent reviews of gene expression during pollen development, see Mascarenhas (1990) and McCormick (1991). OVERVIEW OF POLLEN DEVELOPMENT
Evaluating loan collection performance: An Indonesian example

Abstract This paper discusses the evaluation of loan collection performance in a specialized term-credit program introduced in Indonesia to promote the development of small-scale enterprises. After outlining pertinent characteristics of the credit program, the available collection performance indicators are described and appraised. It is shown that program managers and bankers had access to quite a lot of data on collection performance, but none that provided meaningful information for evaluating loan recovery. The paper then examines sources of the evaluation problem, and suggest methods for developing more accurate and less ambiguous indicators of portfolio quality, loan recovery rates, and ultimate bad debt costs.
Spontaneous wound dehiscence after removal of single continuous penetrating keratoplasty suture

Abstract Purpose To determine the incidence and complications of spontaneous wound dehiscence after removal of a single continuous penetrating keratoplasty (PK) suture. Design Retrospective consecutive, noncomparative interventional case series. Methods Retrospective review of 324 consecutive continuous suture PKs performed between 1992 and 1999. Results Sixty-nine (21.3%) of 324 PKs reviewed had the continuous suture removed. The average interval for suture removal after PK was 24.5 ± 15 months (range, 2.8–63.3 months). Five of the 69 eyes (7.2%) developed spontaneous wound dehiscence without direct eye trauma. In the five eyes that developed wound dehiscence, the continuous suture was removed at 24.6 ± 10.3 months (range, 14–42 months). Dehiscence occurred at 11.6 ± 6.5 (range, 3–18) days after suture removal. Significant history associated with wound dehiscence included coughing, yawning, falling without trauma to the eye, and spontaneous wound separation. The reasons for suture removal were astigmatism in four of five (80%) patients and a broken suture in one of the five patients. In four of five (80%) patients, the location of wound dehiscence correlated with the steep axis of corneal keratometry before suture removal. Surgical intervention preserved the presuture removal best-corrected visual acuity in four of the five eyes. No eyes with an intact suture spontaneously dehisced. Conclusions The rate of spontaneous wound dehiscence after removal of a continuous suture in our series was 7.2%. All spontaneous dehiscences occurred within 2 weeks after suture removal. Older patients, who had PK for corneal edema with postoperative astigmatism and have been using corticosteroids drops for prolonged periods of time, are at higher risk of wound dehiscence. Patients should be monitored closely during the first 2 weeks after removal of a continuous suture for signs of wound separation, especially when suture removal is performed for astigmatism. Patients should be cautioned about the risk and symptoms of wound dehiscence before suture removal to facilitate early recognition and intervention for preservation of best visual potential.
Multimodal protocol reduces postoperative nausea and vomiting in patients undergoing Le Fort I osteotomy.

Purpose To assess the impact of a multimodal antiemetic protocol on postoperative nausea and vomiting (PONV) after Le Fort I osteotomy. Materials and Methods Consecutive patients undergoing Le Fort I osteotomy with or without additional procedures at a single academic institution were recruited as the intervention cohort for an institutional review board–approved prospective clinical trial with a retrospective comparison group. The intervention cohort was managed with a multimodal antiemetic protocol, including total intravenous anesthesia; prophylactic ondansetron, steroids, scopolamine, and droperidol; gastric decompression at surgery end; opioid-sparing analgesia; avoidance of morphine and codeine; prokinetic erythromycin; and fluids at a minimum of 25 mL/kg. The comparison group consisted of consecutive patients from a larger study who underwent similar surgical procedures before protocol implementation. Data, including occurrence of PONV, were extracted from medical records. Data were analyzed in bivariate fashion with the Fisher exact and Wilcoxon rank-sum tests. Logistic regression was used to compare the likelihood of nausea and vomiting in the 2 cohorts after controlling for demographic and surgical characteristics. A P value less than .05 was considered significant. Results The intervention (n = 93) and comparison (n = 137) groups were similar in gender (58% and 65% female patients; P = .29), race (72% and 71% Caucasian; P = .85), age (median, 19 and 20 years old; P = .75), proportion of patients with known risk factors for PONV ( P = .34), percentage undergoing bimaxillary surgery (60% for the 2 groups), and percentage for whom surgery time was longer than 180 minutes (63% and 59%; P = .51). Prevalence of postoperative nausea was significantly lower in the intervention group than in the comparison group (24% vs 70%; P P = .0013). The likelihood that patients in the comparison group would develop nausea was 8.9 and that for vomiting was 3.7 times higher than in the intervention group. Conclusion This multimodal protocol was associated with substantially decreased prevalence of PONV in patients undergoing Le Fort I osteotomy.
A “Schizophotonic” All-In-One Nanoparticle Coating for Multiplexed SE(R)RS Biomedical Imaging

SERS nanoprobes for in vivo biomedical applications require high quantum yield, long circulation times, and maximum colloidal stability. Traditional synthetic routes require high metal–dye affinities and are challenged by unfavorable electrostatic interactions and limited scalability. We report the synthesis of a new near-IR active poly(N-(2-hydroxypropyl) methacrylamide) (pHPMA). The integration of various SERS reporters into a biocompatible polymeric surface coating allows for controlled dye incorporation, high colloidal stability, and optimized in vivo circulation times. This technique allows the synthesis of very small (<20 nm) SERS probes, which is crucial for the design of excretable and thus highly translatable imaging agents. Depending on their size, the “schizophotonic” nanoparticles can emit both SERS and fluorescence. We demonstrate the capability of this all-in-one gold surface coating and SERS reporter for multiplexed lymph-node imaging.
Thromboxane Receptor Blockade (SQ 29,548) in Group B Streptococcal Toxin Challenge in Young Lambs

Early-onset neonatal group B beta-hemolytic streptococcus (GBS) infection exhibits pathophysiologic characteristics of a toxic shock syndrome, in which a cascade of inflammatory mediators are involved. Thromboxane A2 (TXA2) is thought to play an important role as a mediator of the pulmonary response to GBS toxin, because high lung lymph concentrations of a TXA2 metabolite have been observed after GBS toxin injections in sheep. The aim of this study was to evaluate the effects of a selective antagonist of the TXA2-prostaglandin endoperoxide receptor (SQ 29,548). Six unanesthetized young lambs, each serving as its own control, were given SQ 29,548 or vehicle control followed by GBS toxin challenge. Hemodynamic and lung function (lung mechanics, lung volume, ventilation) responses were followed for 5 h. When compared with the control studies, treatment with SQ 29,548 significantly altered the response to GBS toxin. SQ 29,548 reduced the increase in pulmonary and systemic vascular resistance, improved cardiac output and stroke volume, improved dynamic lung compliance but not airway resistance, and improved oxygenation. The attenuating effect of SQ 29,548 was most pronounced during the first phase of toxin response (15-90 min after toxin infusion), but significant treatment effects were also seen during the second phase (120-300 min after toxin infusion). This study demonstrates that TXA2 is an important mediator of the response to GBS toxin and is responsible for hemodynamic and lung function changes. Thromboxane receptor blockade may offer a potential therapeutic approach to infants with severe early-onset GBS sepsis.
The Mechanism of Action of Dobutamine

Excerpt To the editor: The review by Leier and Unverferth (1) detailing 5 years of clinical experience with the inotropic agent, dobutamine, is an invaluable reference source. There are two points ...
Helpfulness to Lost Tourists

Abstract In this field study, the helpfulness of natives to English-speaking tourists was measured in Salzburg, Austria; Florence, Italy; and Prague, Czech Republic. Helpfulness, the willingness of participants to provide the tourists-confederates with directions to popular landmarks, occurred in 77% of the 366 cases. Participants in Salzburg, Austria, were most attentive to the confederates' requests for directions. Male participants stood closer, spent more time, and listened more attentively to requests for directions from female confederates than to those from male confederates. Neither the city in which the helping situations occurred nor the gender of the participants was significant in the rate of giving directions. Participants similar in age to the confederates gave directions more often than did those who were older. More frequent assistance occurred during encounters on sunny or partly sunny days than during encounters on cloudy or rainy days.
Toward an Open Cloud Marketplace: Vision and First Steps

Cloud computing's transition from a subject of research and innovation to a critical infrastructure is proceeding incredibly quickly. One potentially dangerous consequence of this speedy transition is the premature adoption and ossification of the models, technologies, and standards underlying this critical infrastructure. Further exacerbating this issue, innovative research on production-scale platforms is becoming the purview of just a few public cloud providers. Specifically, academic research communities are effectively excluded from contributing meaningfully to the evolution--not to mention innovation and healthy mutation--of cloud computing technologies. As our society and economy's dependency on cloud computing increases, so does the realization that the academic research community can't be shut out from contributing to the design and evolution of this critical infrastructure. Here, the authors provide an alternative vision--the Open Cloud Exchange (OCX), a public cloud marketplace in which many stakeholders, rather than just a single cloud provider, participate in implementing and operating the cloud. This will create an ecosystem to bring the innovation of a broader community to bear on a much healthier and more efficient cloud marketplace.
PALATABILITY OF BONELESS FRESH PORK HAM AND LEG OF LAMB PREPARED BY INTERRUPTED COOKING PRIOR TO FROZEN STORAGE

SUMMARY –Boneless fresh pork hams and legs of lamb were scored acceptable or above in palatability when prepared by the “roasteak’ procedure, involving preroasting to 44°C, slicing and chilling or freezing for as long as 6 months before grilling. Significant differences in means for flavor and juiciness indicated that an antioxidant dip (sodium tripolyphosphate-sodium ascorbate) is advisable for pork roasteaks subjected to freezing, but no such advantage was noted for antioxidant treatment of lamb roasteaks. Although there were differences in tenderness due to muscle within roasteak slices, meat from both muscles of both species was acceptable to the panel in this attribute. Total cooking losses for the roasteak method were higher than for one-step roasting.
Intelligence, Information Processing, and Specific Learning Disabilities A Triarchic Synthesis

Information processing theories of intelligence offer a potentially rich yet generally unexplored theoretical forum for conceptualizing and investigating learning disabilities. The purpose of this article is to advance our understanding of the nature of specific learning disabilities by using Sternberg's (1985) triarchic theory of human intelligence as a framework for expanding the componential-deficit approach. Specifically, deficient cognitive strategies and inadequate knowledge in certain domains may result from learning disabled individuals' inability to (a) selectively encode, compare, and combine information, or (b) automatize information processing. In addition, this article emphasizes the importance of the experiential, contextual, and motivational history of the learning disabled individual in understanding his or her componential deficits.
A note on heterojunction discontinuities

Recently, an analytic proof has been advanced to the effect that the intrinsic Fermi level of a heterojuntion is by necessity continuous across the interface joining two different semiconductors. Here we wish to show that the proof given is incorrect and that the solution of Poisson's equation for an intrinsic heterojunction on which the proof was based, does not yield any information on possible continuities or discontinuities of the intrinsic Fermi level.
A Quantum Cascade Laser-Based Reflectometer for On-Orbit Blackbody Cavity Monitoring

Abstract Satellite measurements pinned to international standards are needed to monitor the earth’s climate, quantify human influence thereon, and test forecasts of future climate change. Credible observations require that measurement uncertainties be evaluated on orbit during a mission’s operational lifetime. The most accurate spaceborne measurements of thermal infrared radiance are achieved with blackbody calibration. The physical properties of blackbody cavity surface coatings are known to change upon extended exposure to the low earth orbit environment. Any such drift must be quantified to continue correctly calibrating observed radiance on orbit. A method is presented to diagnose the effective emissivity of a blackbody cavity in situ using a quantum cascade laser (QCL)-based reflectometer. QCLs provide high-power single-mode output in the thermal infrared and have small mechanical footprints that facilitate integration into existing optical systems. The laser reflectivity in a test blackbody cavity w...
Prenatal cocaine exposure enhances responsivity of locus coeruleus norepinephrine neurons: role of autoreceptors.

Abstract Children exposed to cocaine during gestation have a higher incidence of neurobehavioral deficits. The neurochemical bases of these deficits have not been determined, but the pharmacology of cocaine and the nature of the abnormalities suggest that disruptions in catecholaminergic systems may be involved. In the current study, we used a rat model of prenatal cocaine exposure to examine the impact that this exposure has on the locus coeruleus (LC) noradrenergic system in offspring. Pregnant rats received twice-daily i.v. injections of cocaine (3 mg/kg) or saline between gestational days 10 and 20, and progeny were tested as juveniles. Exposure to a mild stressor elevated an index of norepinephrine turnover in the prefrontal cortex and also increased Fos expression in tyrosine hydroxylase–positive LC neurons in rats exposed to prenatal cocaine but not in rats exposed to prenatal saline. No change in the number of tyrosine hydroxylase-positive neurons in the LC was observed between the two prenatal treatment groups. Specific binding of [ 125 I]-para-iodoclonidine, a radioligand with specificity for high affinity α2A-adrenergic receptors, was decreased in the LC of rats exposed to prenatal cocaine compared with prenatal saline controls. As α 2 -adrenergic receptors on LC norepinephrine neurons function as autoreceptors, their down-regulation by prenatal cocaine exposure provides a plausible mechanism for the observed heightened reactivity of norepinephrine neurons in these animals. These data indicate that prenatal cocaine exposure results in lasting changes to the regulation and responsivity of rat LC norepinephrine neurons. A similar dysregulation of LC norepinephrine neurons may occur in children exposed to cocaine during gestation, and this may explain, at least partly, the increased incidence of cognitive deficits that have been observed in these subjects.
Attack elicited by stimulation of the thalamus and adjacent structures of cats.

The thalamus of unanesthetized unrestrained cats was explored stereotaxically for sites which when electrically stimulated will either give rise to attack, facilitate attack elicited from the hypothalamus, or suppress such attack. A quiet biting form of attack could be elicited from the medial portion of nucleus dorsalis medialis, the caudal portion of nucleus reuniens, the midline region of nucleus centralis medialis, and anterolateral portions of nucleus reticularis. Facilitation of hypothalamic attack also occurred with stimulation of these same sites. In addition, facilitation was observed from sites that did not give rise to attack. These include nucleus ventralis anterior, area subparafascicularis, and the paraventricular region medial to the nucleus parafascicularis. Suppression of attack was elicited by stimulation of sites which by themselves gave rise to retreat from discrete objects in the environment, or to "fear-like" responses. The areas whose excitation suppressed attack include anterolateral portion of the reticular nucleus, the region of the anterior thalamic radiations, the rostral portion of nucleus reuniens, nucleus interoanteromedialis, somewhat lateral portions of nucleus dorsalis medialis and posterior portions of centrum medianum. The responses seen by a number of previous investigators are also confirmed. Finally, the possible pathways mediating attack and its suppression are discussed.
Physical and Chemical Characteristics of Water-Soluble, Semisolid, Anhydrous Bases for Possible Ophthalmic Use

Abstract Following a preliminary review of pertinent literature citations, a total of 84 semisolid, water-soluble, anhydrous bases for possible ophthalmic use was formulated. Of these 84 exploratory bases, five were designated evaluatory bases for further study on the basis of apparent pH and/or desirable physical spread- ability characteristics over the temperature range of 0-50°. Four of the five bases were further characterized by rotational viscometer studies, and an organogel was selected on the basis of several of its listed attributes as the best attempt in this investigation to formulate the type of semisolid base desired for possible ophthalmic use.