cssi/SciSciGPT-SciSciNet huggingface dataset:
Auditory Perception of Sequenced Words in Apraxia of Speech

In a test of auditory perception of phonemes, 10 patients with apraxia of speech were compared with 10 matched normal control subjects on a task of pointing to pictures designated by sequences of a...
Long-term prognosis of children with papillary thyroid cancer presenting with pulmonary metastases

Background Papillary thyroid cancer (PTC) has a generally favourable prognosis, but elderly patients with distant metastases or extracapsular invasion fair poorly. In small studies with short follow-up, young patients presenting with such extracapsular invasion and pulmonary metastases have faired well. This retrospective study was undertaken to clarify the long-term prognosis of such patients with advanced PTC. Methods Twenty-one children and young adults (median age 14 (range 6–20) years) presenting with PTC and pulmonary metastases were treated at a single institution between 1947 and 1998. Mean maximal tumour diameter was 4·65 cm. Initial surgical treatment consisted of total thyroidectomy (n = 16), subtotal thyroidectomy (n = 4) and isthmectomy (n = 1), coupled with a variety of lymph node dissections (n = 20). After operation, 19 patients were treated with ablative and incremental doses of iodine-131 until disease free. All patients were placed on suppressive thyroid hormone after operation. Mean length of follow-up was 21 years (range 3 months to 47 years). Follow-up was less than 3 years in four patients. All patients have undergone post-treatment radionucleotide and radiological evaluation. Results Nine of the 21 patients developed recurrent disease. The risk of recurrence at 5 years was 39 (95 per cent confidence interval 14–57) per cent. Eight had cervical lymph node recurrence and no patient developed recurrent pulmonary disease. All patients with identifiable recurrent disease underwent selective lymph node resection, which involved multiple resections in four. At follow-up, 18 patients remain completely free of disease, one patient has recurrent cervical node disease and two patients have died. The disease-free survival at 5 years was 95 (95 per cent confidence interval 86–100) per cent. Cause-specific death occurred in a single patient who died from extensive local disease at age 29 years after 12 years of multiple cervical lymph node recurrences. Conclusion A stepwise treatment approach including total thyroidectomy, high-dose iodine-131 treatment and early surgical reintervention for suspected local recurrent disease allows long-term survival and frequent ‘cure’ for young patients with PTC and concomitant pulmonary metastases. © 2000 British Journal of Surgery Society Ltd
Polyslip in single crystals

Abstract Simultaneous slip on six or eight glide systems in f.c.c. single crystals was studied by work-hardening, surface, and X-ray observations, and theoretically. Experiments were done on aluminum at room temperature, on four of the five crystallographic types of polyslip. They show that there are two extremely different kinds of behavior, typified by 〈100〉 and 〈111〉 tension. These differences cannot be explained by any of the known mechanisms. Two additional mechanisms are proposed, one for the suppression of “critical” glide systems by the formation of large sessile jogs; the other concerning the action of pile-ups as “hedges” for intersecting glide systems.
Validation and advantages of FAWSETS perfusion measurements in skeletal muscle.

This work discusses the strengths, limitations and validity of a novel arterial spin labeling technique when used specifically to measure perfusion in limb skeletal muscle. The technique, flow-driven arterial water stimulation with elimination of tissue signal (FAWSETS), offers several advantages over existing arterial spin labeling techniques. The primary goal of this study was to determine the perfusion signal response to changes in net hind limb flow that were independently verifiable. The range of perfusate flow was relevant to skeletal muscle during mild to moderate exercise. Localized, single voxel measurements were acquired from a 5 mm-thick slice in the isolated perfused rat hind limb at variable net flow rates. The results show that the perfusion signal is linearly proportional to net hind limb flow with a correlation coefficient of 0.974 (p = 0.0013). FAWSETS is especially well suited for studies of skeletal muscle perfusion, where it eliminates the need to compensate for magnetization transfer and arterial transit time effects. A conceptual discussion of the basic principles underlying these advantages is presented. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and characterization of N-methyliminodiacetato trans-R,R-, trans-S,S-, and cis-1,2-diaminocyclohexane platinum (IV) complexes: crystal structure of chloro(trans-R,R-1,2-diaminocyclohexane) (N-methyliminodiacetato) platinum(IV) chloride.

The compounds, chloro(trans-R,R-1,2-diaminocyclohexane)(N-methyliminodiacetato)platinum(IV) chloride, chloro(trans-S,S-1,2-diaminocyclohexane)(N-methyliminodiacetato)platinum(IV) chloride, and chloro(cis-1,2-diaminocyclohexane)(N-methyliminodiacetato)platinum(IV) chloride, were prepared and characterized by elemental analysis, IR, and 195Pt NMR. The crystal structure of one of these three compounds, chloro(trans-R,R-1,2-diammocyclohexane)(N-methyliminodiacetato)platinum(IV) chloride, was determined by x-ray single crystal diffraction. This compound is particularly interesting because the 1,2-diaminocyclohexane (DACH) ring is in a twist-boat configuration rather than the chair configuration previously reported for other DACH platinum compounds. The crystal structure consists of two independent cations and anions, with all atoms between these two independent molecules (except those in the chiral DACH) related by a pseudo-inversion center. Both platinum atoms have slightly distorted octahedral coordination, with angles ranging from 81.8 to 100.8°. Crystallographic details: space group P21 (monoclinic); a = 19.864(5) A, b = 7.026(2) A, c = 12.446(3) A, β = 106.62(2)°; Z = 4; R = 0.036 for 2333 reflections.
Totally singular quadratic minimization problems

A survey of necessary, sufficient, and necessary and sufficient conditions for optimality for a class of time-varying singular quadratic minimization problems is presented. The development of the theory is traced from the time of discovery of the generalized Legendre-Clebsch condition. The most important conditions are stated in the form of theorems and are proved. Certain lengthy proofs are only outlined and the reader is referred to the literature for details. The reference list is not intended to be a complete bibliography; rather, it contains, in this author's opinion, the most important references in this area.
In Situ FTIR Studies of the Selective Catalytic Reduction of NO by C3H6 over Pt/Al2O3

Abstract The selective catalytic reduction (SCR) of nitric oxide (NO) by propylene (C3H6) over a 0.8 wt% Pt/Al2O3 catalyst was studied by the use of in situ Fourier transform infrared (FTIR) spectroscopy. Spectra of both the Pt/Al2O3 catalyst as well as the bare Al2O3 support were collected during the course of this study. NO adsorption resulted in the formation of nitrate species associated with the Al2O3 support, as well as surface NO species associated with Pt. Similarly, C3H6 adsorption resulted in the formation of carboxylate species associated with Al2O3, as well as surface CO associated with Pt. Finally, experiments conducted with the reactive NO–C3H6–O2 mixture resulted in the formation of surface cyanide (–CN) and isocyanate (–NCO) species. The origin and reactivity of these species is discussed in view of their potential involvement as intermediates in the hydrocarbon–SCR reaction.
Cahokia's Rattlesnake Causeway

Recent archaeological test excavations at the Cahokia Mounds State Historic Site located in Collinsville, IL, document the planned and early construction of a large earthen causeway. Approximately 1-km long and 18-m wide, the Rattlesnake Causeway orientated Cahokia's 5° offset grid and tied Cahokia's central precinct to at least one if not two ridge-top mortuary mounds. The results of this excavation present new information on Cahokia's city plan, one that included the construction of at least 104 earthen monuments, a large central plaza, and an extensive earthen causeway marking the midline of the site.
The proton magnetic resonance spectra of para-substituted triarylphosphine oxides

Abstract The high resolution PMR spectra of thirteen para -substituted triarylphosphine oxides have been determined. Analysis of the observed spectra as ABX leads to a determination of the P 31 -H coupling constants for protons ortho and meta to the phosphorus nucleus. The PMR parameters obtained ar ediscussed with reference to the interaction of the phosphono group with the aromatic ring and in relationship to other arylphosphorus compounds.
Evidence for a cool wind from the K2 dwarf in the detached binary V471 Tauri

Evidence for mass loss from the K2 dwarf in V471 Tauri is found in the form of discrete absorption features in lines of various elements (Mg, Fe, Cr, Mn) and ionization stages (Mg I, Mg II, Fe I, Fe II). Resonant Mg II absorption indicates a mass loss rate of at least 10 to the -11th solar masses per year. The wind appears to be cool (no more than a few times 10,000 K).
An interpolation approach to multiobjective ℋ ∞ design

A problem of practical importance is to find a linear controller that shapes the closed loop frequency responses in some desirable fashion. When the magnitude of the target shapes is specified, this problem may be cast as that of finding a controller such that several ℋ ∞ norms satisfy specified bounds. In this paper we show that, under suitable assumptions, an exact solution to this multiobjective ℋ ∞ problem can be obtained. The method we propose requires the solution to: (1) a finite-dimensional linear matrix inequality problem, and (2) a standard single objective ℋ ∞ problem for a suitably constructed auxiliary plant. We illustrate the results with a numerical example.
Prediction error variance and restricted maximum likelihood estimation for animal model with relationship grouping.

Genetic evaluation using animal model with relationship grouping has been shown to be feasible. However, algorithms were unavailable for prediction error variance and REML estimation of variance components. This paper shows that prediction error variance of an estimable function of the total merit of additive genetic and group effects is a simple function of a generalized inverse of the coefficient matrix for a transformed mixed model equation or of the inverse of the coefficient matrix when it is restricted to full rank. The REML algorithms, using the transformed equation, have slightly more complicated expressions than usual but could be more feasible computationally. Formulae for prediction error variance apply in general. The REML algorithms are extended to an animal model with an arbitrary number of random factors and can be extended to estimate covariance components.
Fanconi anemia cell lines deficient in αII spectrin express normal levels of αII spectrin mRNA

Abstract Fanconi anemia is a genetic disorder characterized by hypersensitivity to DNA interstrand cross-linking agents and a defect in the ability to repair this type of damage. This deficiency correlates with reduced levels of αII spectrin, a structural protein involved in the repair of DNA interstrand cross-links. The present study addresses the question of whether the reduced levels of αII spectrin in FA-A, FA-C, and FA-G cells are due to reduced expression of this protein and/or due to differences in the three regions of alternate splicing of αII spectrin mRNA. Relative quantitative RT-PCR showed that levels of αII spectrin mRNA in the three FA cell lines were similar to normal as were the sites of alternative mRNA splicing. These results indicate that decreased levels of αII spectrin in these FA cell lines are not due to reduced expression of αII spectrin mRNA or due to differences in regions of alternate splicing of these transcripts, but rather appear to be related to reduced stability of αII spectrin in these cell lines.
The effect of rapid preconditioning on the microglial, astrocytic and neuronal consequences of global cerebral ischemia.

Previous studies indicated preconditioning of the brain with sublethal ischemic insults separated by many hours, protected tissues from a subsequent lethal insult. We recently reported neuroprotection by a rapid preconditioning paradigm where a sublethal ischemic insult preceded test ischemia by only 30 min. We hypothesize that neuroprotection caused by the rapid ischemic preconditioning (IPC) will result in lowered microglial, reactive astrocytes and increased normal neuronal cell counts. Wistar rats underwent normothermic (36.5–37 °C) global cerebral ischemia, produced by bilateral carotid artery ligation after lowering mean systemic blood pressure. The preconditioning ischemic insult lasted 2 min and was associated with a sufficient amount of time to provoke anoxic depolarization. After a 30-min reperfusion period, 10-min test ischemia was produced, and histopathology was assessed 3 and 7 days later. Normal neuronal cell counts for control rats at 3 days survival were significantly lower (by 58%) than in IPC animals. Although there was a trend toward protection in IPC rats at 7 days, the difference in normal neuronal cell count between the IPC and control groups was not significant. IPC rats at 3 days but not 7 days of survival showed a significantly lower microglial cell count (by 56%) than control rats. These results showed that the protection induced through IPC at 3 days of survival produced lower numbers of microglia, while maintaining normal neuronal cells. No significant differences between control and IPC groups were found in astrocytic cell count at any time of reperfusion in any region of the hippocampus studied. The beneficial effects of IPC may, therefore, involve anti-inflammatory processes that target microglial activation after cerebral ischemia.
Clustering Based on Periodicity in High-Throughput Time Course Data

Nuclear magnetic resonance (NMR) spectroscopy, traditionally used in analytical chemistry, has recently been introduced to studies of metabolite composition of biological fluids and tissues. Metabolite levels change over time, and providing a tool for better extraction of NMR peaks exhibiting periodic behavior is of interest. We propose a method in which NMR peaks are clustered based on periodic behavior. Periodic regression is used to obtain estimates of the parameter corresponding to period for individual NMR peaks. A mixture model is then used to develop clusters of peaks, taking into account the variability of the regression parameter estimates. Methods are applied to NMR data collected from human blood plasma over a 24-hour period. Simulation studies show that the extra variance component due to the estimation of the parameter estimate should be accounted for in the clustering procedure.
FRACTAL CHARACTERISTICS OF ROCK DISCONTINUITIES

Abstract The discontinuities in a rock mass usually control its overall behavior. Rock mass deformability, stability of underground excavations, and flow of fluid depend significantly on the intensity, the degree of interconnection, and the characteristics of the fracture network present. We apply the theory of fractal geometry to describe the rock fracture network. Three parameters characterize the discontinuities visible in the exposed face of the investigated rock mass. The first parameter measures the complexity of the network formed by the individual traces of the discontinuities. The intensity and the interconnectivity of the discontinuities are characterized by the fracture density and the block density respectively. We use data from four faces of a copper mine in Arizona. All three parameters show fractal characteristics over the range investigated with coefficients of determination better than 0.99. The fractal structure of these parameters suggests that the rock fracturing process may be a scale-independent phenomenon.
One hundred consecutive advanced breast biopsy instrumentation procedures: complications, costs, and outcome.

Background: Needle localization and excision have been the preferred techniques for treating nonpalpable mammographic abnormalities. Recently, a less invasive approach, using the Advanced Breast Biopsy Instrumentation (ABBI) system, was introduced. This study was undertaken to determine the feasibility, utility, and cost of this new alternative approach.
Calciferol 25-hydroxylase activity in smooth and rough endoplasmic reticulum of rat liver.

Abstract Calciferol 25-hydroxylase activity of vitamin D-deficient rats was measured in both liver microsomes and submicrosomal fractions. The smooth and rough-surfaced microsomes were prepared by a density gradient centrifugation technique in the presence of cesium chloride. Purity of the isolated microsomal membranes was ascertained by electron microscopy, RNA determination, measurement of enzyme markers, and by labeling of the cytoplasmic RNA with [5- 3 H]orotic acid. Calciferol 25-hydroxylase activity was present in both smooth and rough-surfaced microsomes. The specific activity of the enzyme was greater in the rough fraction. There was a linear relation between enzymic activity and the concentration of enzyme for both total and submicrosomal fractions. These data show the presence of calciferol 25-hydroxylase activity in both smooth and rough-surfaced microsomes isolated from livers of vitamin D-deficient rats.
“Get High on Yourself”: The Effectiveness of a Television Campaign on Self-Esteem, Drug Use, and Drug Attitudes:

The effectiveness of a week long television campaign — Get High on Yourself — was assessed at three urban high schools, through measures of self-esteem, drug use, and drug attitudes administered ten days prior to the campaign and four weeks later. The results indicate no significant changes that could be attributed to the campaign. A significant relationship was obtained between level of self-esteem, drug use, and drug attitudes.
Design and implementation of a modern compiler course

Current literature states that the undergraduate curriculum can no longer afford the luxury of a traditional compiler construction course. Nevertheless, there is an increasing need for an understanding of how to design and implement domain-specific languages. This paper presents a modern course in compiler construction, designed to provide a student with the capability of quickly constructin robust processors for a variety of language-related applications.
Age difference in perceptual judgment on the Mueller-Lyer illusion.

Reduction in the Mueller-Lyer illusion was compared among children, adults, and the aged. Practice with red horizontals produced greater reduction in illusion than did practice with a black horizon...
Motivations for Sex Among Low-Income African American Young Women:

African American young women exhibit higher risk for sexually transmitted infections, including HIV/AIDS, compared with European American women, and this is particularly true for African American women living in low-income contexts. We used rigorous qualitative methods, that is, domain analysis, including free listing (n = 20), similarity assessment (n = 25), and focus groups (four groups), to elicit self-described motivations for sex among low-income African American young women (19-22 years). Analyses revealed six clusters: Love/Feelings, For Fun, Curiosity, Pressured, For Money, and For Material Things. Focus groups explored how African American women interpreted the clusters in light of condom use expectations. Participants expressed the importance of using condoms in risky situations, yet endorsed condom use during casual sexual encounters less than half the time. This study highlights the need for more effective intervention strategies to increase condom use expectations among low-income African Ame...
Goals and Teaching English Language Classes

L'A. developpe une reflexion a partir de son experience personnelle de professeur d'anglais dans une universite americaine. Il s'attache en particulier a l'influence du facteur race dans ce contexte et a l'enseignement de l'anglais vernaculaire afro-americain. Il recommande a ses etudiants une strategie d'autoregulation afin d'optimiser leur apprentissage et developper leurs competences
Circuit technique for semiconductor-device analysis with junction diode open circuit voltage decay example

Abstract The application history of the circuit technique for semiconductor-device analysis is reviewed with a discussion of its specific application advantages, including providing accurate solutions. An illustration of the use of this technique for the time dependence of the open circuit voltage decay across an initially forward biased p/n junction is given. The illustration also presents a new solution method of the lumped model which gives the correct time dependence, √ t , for the initial transient.
Obtaining the Sensed Temperatures From a Detailed Model of a Welded Thermocouple

When imbedded in dissimilar materials subject to large temperature gradients, thermocouples are known to yield erroneous (bias) temperature measurements. It has been established that the bias error may be accounted for with an appropriate computational model and the measured temperatures may be corrected with an appropriate kernel function. In this work, a thermocouple with a welded bead is considered. Early two-dimensional models considered the thermocouple to be a single wire with effective thermal properties. The model in the current investigation is three-dimensional and represents the sensor as two wires, each with unique thermal properties. The welded bead is represented as a separate entity with properties distinct from those of the wires. The problem of determining what location in the three-dimensional model corresponds to the measured temperature is considered. Earlier models have considered the sensed temperature to be the temperature at the tip of the two-dimensional thermocouple or, in three-dimensional models, the temperature at the center of the volume of the welded bead. In the current work, a theory is set forth for identifying the location at which the temperature is sensed by a thermocouple. This theory is in line with traditional thermoelectric theory and is supported with experimental evaluation with thermal imaging as well as examination of thermocouples by scanning electron microscopy and energy dispersive X-ray analysis. The significance of accurate modeling of the sensed temperatures is demonstrated with a numerical experiment.Copyright © 2008 by ASME
Ideas About Social Research, Evaluation, and Statistics in Medieval Arabic Literature: Ibn Khaldun and al-Biruni

This is a review of evidential ideas that appear in the Muqadimmah and India, Medieval Arabic works. The ideas concern numerical evidence, its collection, distortion, analysis, and interpretation, and its use in making statements about change and cause. Potential mistakes in educing the ideas from such translated texts are discussed briefly. Erudite attention to the topic is encouraged in the interest of understanding early parallels to contemporary evaluation problems.
ASP effects in the small-sized enterprise: the case of the Bizmeka service from Korea Telecom

An application service provider (ASP) is a business model providing information technology (IT)-enabled solutions to customers over the Internet. Utilizing an ASP model, small and medium-sized enterprises (SMEs) can acquire affordable IT solutions. Korea Telecom (KT), a leading IT company in Korea, provides an ASP service called Bizmeka to SMEs. In this study, we identify factors influencing the perceived benefits of Bizmeka usage. We also examine the relationship between the perceived benefits of Bizmeka usage and customer satisfaction. Based on the results of our survey, we found the following factors to be important in determining customer satisfaction with ASPs: cost and time impact, maintenance impact, and security risks.
HIV nuclear import is governed by the phosphotyrosine-mediated binding of matrix to the core domain of integrase

The karyophilic properties of the viral matrix (MA) protein govern HIV nuclear import in nondividing cells such as macrophages. A critical regulator of this process is the C-terminal tyrosine phosphorylation of MA during virus maturation. Here, we reveal the mechanism of this phenomenon, by demonstrating that tyrosine phosphorylation induces the binding of MA to integrase (IN). This leads to the incorporation of MA molecules into virus cores, and subsequently into uncoated viral nucleoprotein complexes. A direct interaction between tyrosine-phosphorylated MA and the central domain of IN can be demonstrated in vitro. It is blocked by phosphotyrosine, indicating that IN recognizes the phosphorylated C-terminal residue of MA. These results explain how the karyophilic potential of MA is conferred to the HIV nucleoprotein complex.
A New Model For The Geometric Correction Of Multispectral Scanner Data

An analytic model is developed for the geometric rectification of aircraft multispectral scanner data using information on the position and attitude of the aircraft. The model is implemented by constructing a set of cubic spline approximations to the aircraft position and attitude. The splines are computed using a generalized Newton's method to obtain a best fit to a given set of match points. Several tests were run using various numbers and sizes of segments, and several sets of checkpoints. The results are presented with analysis indicating a high degree of accuracy and reliability in the method.
Reduced sulfur compounds in gas from construction and demolition debris landfills

Abstract The biological conversion of sulfate from disposed gypsum drywall to hydrogen sulfide (H2S) in the anaerobic environment of a landfill results in odor problems and possible health concerns at many disposal facilities. To examine the extent and magnitude of such emissions, landfill gas samples from wells, soil vapor samples from the interface of the waste and cover soil, and ambient air samples, were collected from 10 construction and demolition (C&D) debris landfills in Florida and analyzed for H2S and other reduced sulfur compounds (RSC). H2S was detected in the well gas and soil vapor at all 10 sites. The concentrations in the ambient air above the surface of the landfill were much lower than those observed in the soil vapor, and no direct correlation was observed between the two sampling locations. Methyl mercaptan and carbonyl sulfide were the most frequently observed other RSC, though they occurred at smaller concentrations than H2S. This research confirmed the presence of H2S at C&D debris landfills. High concentrations of H2S may be a concern for employees working on the landfill site. These results indicate that workers should use proper personal protection at C&D debris landfills when involved in excavation, landfill gas collection, or confined spaces. The results indicate that H2S is sufficiently diluted in the atmosphere to not commonly pose acute health impacts for these landfill workers in normal working conditions. H2S concentrations were extremely variable with measurements occurring over a very large range (from less than 3 ppbv to 12,000 ppmv in the soil vapor and from less than 3 ppbv to 50 ppmv in ambient air). Possible reasons for the large intra- and inter-site variability observed include waste and soil heterogeneities, impact of weather conditions, and different site management practices.
Application of uv resonance raman spectroscopy to the detection of monolayers of silane coupling agent on glass surfaces

The silane, PcSi(OH)(OSi(CH3)2(CH = 2)), which has the potential of serving as a new type of coupling agent for fiber glass composites has been studied by UV resonance Raman spectroscopy. This silane is a member of a series of silanes which may lead to hydrolytically stable composites when used as coupling agents. Crystalline samples of the silane without glass and films on E-glass fibers and high-surface-area silica at levels less than a monolayer have been investigated. The Raman line used in these investigations is at 1545 cm−1. This line is used because it gives a strong UV resonance Raman enhancement and because its frequency is dependent on the previous history of the sample. An attempt has been made to interpret the nature of the interaction of the silane with the glass surfaces in terms of the shifts of this line.
Objective and subjective features of children's neighborhoods: relations to parental regulatory strategies and children's social competence

This study examines the relative contributions of objective neighborhood ratings and mothers' and children's perceptions of neighborhood qualities to parental regulatory and supervisory strategies and social adjustment of third graders. Sixty-three children (32 boys, 31 girls) from a range of neighborhoods in two midsized, Southern California communities and their mothers comprised the sample. Information about neighborhoods was derived from surveys and independent raters. Parental supervisory strategies and rules regarding access to the neighborhood were based on telephone interviews. Social adjustment was assessed using standard sociometric protocols, teacher ratings, and a self-report loneliness questionnaire. Mothers' perceptions of poorer neighborhood quality were related to children's social skills and perceived loneliness. In a number of instances, relations were mediated by greater use of regulatory strategies, such as supervision and limitation of activities in less than optimal neighborhoods. The importance of distinguishing subjective and objective views of neighborhoods is emphasized.
A role for chemokine signaling in neural crest cell migration and craniofacial development

Neural crest cells (NCCs) are a unique population of multipotent cells that migrate along defined pathways throughout the embryo and give rise to many diverse cell types including pigment cells, craniofacial cartilage and the peripheral nervous system (PNS). Aberrant migration of NCCs results in a wide variety of congenital birth defects including craniofacial abnormalities. The chemokine Sdf1 and its receptors, Cxcr4 and Cxcr7, have been identified as key components in the regulation of cell migration in a variety of tissues. Here we describe a novel role for the zebrafish chemokine receptor Cxcr4a in the development and migration of cranial NCCs (CNCCs). We find that loss of Cxcr4a, but not Cxcr7b, results in aberrant CNCC migration defects in the neurocranium, as well as cranial ganglia dysmorphogenesis. Moreover, overexpression of either Sdf1b or Cxcr4a causes aberrant CNCC migration and results in ectopic craniofacial cartilages. We propose a model in which Sdf1b signaling from the pharyngeal arch endoderm and optic stalk to Cxcr4a expressing CNCCs is important for both the proper condensation of the CNCCs into pharyngeal arches and the subsequent patterning and morphogenesis of the neural crest derived tissues.
Exposure of Petunia Seedlings to Ethylene Decreased Apical Dominance by Reducing the Ratio of Auxin to Cytokinin

Seedlings of Petunia x hybrida ‘Orchid’ treated with the ethylene-releasing compound ethephon at 0.9, 1.7, and 3.5 mM evolved ethylene at a higher rate as the concentration of ethephon increased. Regardless of the concentration of ethephon applied, ethylene evolution peaked 6 to 8 h following application. Evidence that ethephon application decreased apical dominance included an increase in the number of new nodes on the main stem and a sustained increase in the length of new and existing lateral shoots compared to the control (no ethephon). Plants treated with 3.5 mM ethephon developed mild chlorosis, whereas a concentration of 1.7 mM ethephon decreased apical dominance without phytotoxic effects. The auxin/cytokinin ratio decreased in the apical shoot section as early as 1 h after ethephon treatment. In contrast, a decrease in the ratio in the subapical shoot section was not detected until 24 h after ethephon application. Reduction in auxin/cytokinin ratio was a result of a decrease in indole-3-acetic acid (IAA) and an increase of zeatin riboside (ZR), but not isopentenyladenosine (iPA). These results suggest that exposing ‘Orchid’ petunia seedlings to ethylene via ethephon lowers the auxin/cytokinin ratio, thereby promoting the outgrowth of lateral shoots.
Secretion of dopamine into hypophysial portal blood by rats bearing prolactin-secreting tumors or ectopic pituitary glands

Catecholamines were quantified in hypophysial portal plasma obtained from cycling diestrous rats and from noncycling diestrous rats with hyperprolactinemia due to PRLsecreting pituitary explants or a PRL-secreting pituitary tumor. In rats bearing PRL-secreting tumors, the plasma concentration of PRL was 4450 ± 938 ng/ml (mean ± SE), whereas in cycling diestrous animals the plasma level of PRL was 16 ± 2.2 ng/ml. The concentration of dopamine in hypophysial portal plasma of tumor-bearing rats (2.0 ± 0.3 ng/ml) was significantly greater (P < 0.05) than that in diestrous rats (1.1 ± 0.2 ng/ml). The anterior pituitary content of PRL was 18 ± 1.5 μg in cycling diestrous animals and 9 ± 0.8 μg in tumor-bearing rats. The adrenals from tumor-bearing animals were much heavier (155 ± 14 mg) than those from cycling diestrous rats (58 ± 1.2 mg). The concentration of dopamine in portal plasma from tumor-bearing adrenalectomized rats was 2.0 ± 0.5 ng/ml, similar to that in portal plasma from tumor-bearing intact animal...
Building a space weather aerie in Armenia.

According to the information provided in Richard Stone's article “A space weather aerie in the Caucasus?” (News Focus, 29 Aug., p. [1175][1]), there seems to be no reason why the Cosmic Ray Division (CRD) of the Yerevan Physics Institute should not be supported in its efforts to develop a worldwide solar storm alert service. Quality research in Armenia is cost-effective, and the reputation of Armenian scientists is extremely high. Moreover, the cosmic ray monitoring stations on Armenia's Mount Aragats are ideally situated for such research and for providing valuable data to international partners. The recent electrical blackout in the northeastern United States and parts of Canada illustrated the vulnerability of our power distribution networks. Similar power outages can be triggered by solar storms. The article mentions, as an example, the failure of Quebec's power grid in March 1989. The cost of funding CRD's space weather research is small in comparison to the potential savings that will result from the ability to forecast dangerous solar events. One must also consider the consequences of losing key intelligence and communications satellites due to the effects of solar storms. Thus, an effective solar alert service would not only be of economic value, it would also enhance our security. [1]: /lookup/doi/10.1126/science.301.5637.1175
Fœtal Hæmoglobin and Erythroblastosis

IN a recent communication, Jonxis1 reports quantitative estimations of alkali-resistant and labile haemoglobin in cases of haemolytic disease of the newborn. He comes to the conclusion that after birth only haemoglobin of the labile, adult type is formed, and that in haemolytic disease of the new-born there is a selective destruction of red blood corpuscles containing fœtal haemoglobin. We carried out in the years 1939–42 a great number of similar estimations; these have been briefly reported previously elsewhere2,3.
Using stratification to estimate multimodal density functions with applications to regression

Large populations, particularly large human populations, are usually composed of several different subpopulations. We want to utilize this fact to provide a means of improving on the choice of the bandwidth of the kernel density by combining the separate density estimates of the subpopulations. This will provide an improvement on the overall density estimate for the entire population.
Defined Clinical Classifications Are Associated with Outcome of Patients with Anatomically Resectable Pancreatic Adenocarcinoma Treated with Neoadjuvant Therapy

Background We previously introduced a classification system for patients with localized pancreatic adenocarcinoma that integrates assessments of tumor anatomy, cancer biology, and patient physiology. By means of this system, we sought to analyze outcomes of patients with resectable anatomy but heterogeneous biology and physiology who were treated with neoadjuvant therapy.
Role of water vapor and CO2 in the paleoclimatic fluctuations along northwestern and southern Syria, and the adjacent Mediterranean Sea

Abstract Microscopic petrified grains were collected from a mafic–ultramafic pipe, NE of Dreikeesh, NW Syria. The grains were identified as anthers/gynoecia in herb/grass flowers. Three of the grains showed evidence of magnetism, two slowly dissolved in concentrated HCl, and three microprobed grains showed a montmorillonitic composition. Iron originating from pyroxene was oxidized to magnetite. Released silica formed the mineral suite agate–chalcedony–opal. Warm/cold paleoclimatic fluctuations, occurring during late Pliocene–Holocene, depended on water vapor, CO 2 production, and cinders in the atmosphere. Most of these were associated with changing volcanic/tectonic events. Fluctuations were controlled by heat reflected from the Earth's surface being absorbed by water vapor and CO 2 , which both re-reflected the heat back to the surface, thus, raising the temperature. This cycle was repeated several times during late Pliocene–Holocene.
First Report of Oregon Grape (Mahonia aquifolium) as an Alternate Host for the Wheat Stripe Rust Pathogen (Puccinia striiformis f. sp. tritici) Under Artificial Inoculation

As the primary host of the stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst), wheat can be infected by both aeciospores and urediniospores, and later is the host that gives rise to ur...
Binding of calcium by proteoglycans in vitro

Proteoglycans from bovine nasal septa or the Swarm rat chondrosarcoma, as potassium salts, effectively inhibit the precipitation of tricalcium phosphatein vitro at pH 7.8. The same preparations, and many other similar preparations, however, do not site bind calcium, as assessed with a calcium ion specific electrode. However, after treatment of aggregate preparations of proteoglycans with EDTA, the preparations can site bind calcium. The amount thus bound is approximately equal to one-half the sum of the equivalents of the ester sulfate and the uronic acid carboxyl groups in the preparations. This latter observation suggested the possibility that the supposed potassium salts of the proteoglycans had, in the course of preparation, acquired calcium and held onto it strongly. In checking this possibility, using neutron activation analysis, it was found that some of the preparations do contain small amounts of calcium but these amounts are insufficient to saturate the binding sites potentially available to this end. In view of the above observations, it is suggested that the proteoglycans inhibit the formation of calcium phosphate precipitatesin vitro not because the calcium is site bound but because the calcium ions are territorially bound.
Nephrolithiasis followingintestinal bypass for obesity

Abstract A case of nephrolithiasis following intestinal bypass for obesity is presented. The pathophysiology of stone formation in such patients is discussed. Cholestyramine therapy is recommended for those patients with hyperoxaluria.
The use of tissue adhesive in corneal perforations.

Eighty patients with either corneal perforation or impending perforation were treated with the application of tissue adhesive that remained in place on the average of 50 days. Forty-four percent of these cases healed with the application of glue alone. Complications occurred in nine patients (11 %). Two developed marked increase in intraocular pressure that was controlled with antiglaucoma medications and seven developed corneal infiltrates. Five of the infiltrates were culture-proven bacterial infections occurring on the average of 73 days after gluing. The relationships between diagnosis, duration of glue, and complications are reviewed.
Arabinose induces pellicle formation by Vibrio fischeri

Biofilms are multicellular communities of bacteria attached to a surface and embedded in a protective matrix. In many cases, the signals that induce biofilm formation are unknown. Here, we report that biofilm formation by the marine bacterium Vibrio fischeri can be induced by the addition of arabinose to LBS (Luria-Bertani-salt), a tryptone-based medium. Growth of cells in the presence of 0.2% arabinose, but not other sugars, induced the production of a pellicle at the air/liquid interfaces of static cultures. V. fischeri failed to grow on arabinose as the sole carbon source, suggesting that pellicle production did not occur as a result of increased growth, but experiments using the acid/base indicator phenol red suggested that V. fischeri may partially metabolize arabinose. Pellicle production was independent of the syp polysaccharide locus but was altered upon disruption of the bcs cellulose locus. Through a screen for mutants defective for pellicle production, we found that loss of motility disrupted the formation of the arabinose-induced pellicle. Among the ∼20 mutants that retained motility were strains with insertions in a putative msh pilus locus and a strain with a defect in yidK, which is involved in galactose catabolism. Mutants with the msh gene disrupted grew poorly in the presence of arabinose, while the yidK mutant appeared to be "blind" to the presence of arabinose. Finally, arabinose impaired symbiotic colonization by V. fischeri. This work thus identifies a novel signal and new pathways involved in control of biofilm formation by V. fischeri.
Optimizing coherent lidar performance with graded-reflectance laser resonator optics

We demonstrate how the design of graded-reflectance output coupler unstable laser cavities may be tailored to significantly enhance the overall power transmission efficiency of a given laser system relative to that of a conventional diffractively coupled unstable resonator. The importance of these findings in coherent lidar applications is explained with particular emphasis on projected space-based systems.
pH-dependent intracellular quenching of the indicator carboxy-SNARF-1.

Carboxy-SNARF-1 is an emission-changing, pH-sensitive probe for measurements of intracellular pH. However, the protonated and deprotonated forms of the dye interact differently with intracellular constituents, and this imposes new requirements on the calibration of the system. Whole spectra of intracellular and extracellular C.SNARF-1 were analyzed and showed (1) intracellular quenching which was significantly greater for the deprotonated form of the dye than for the protonated state and (2) a detectable change in pKa. Importantly for avoiding damage to cells, this mathematical analysis allowed reference spectra for fully protonated and fully deprotonated dye to be obtained without a need for spectra measured at extreme values of pH. It is not known what constituent(s) of the intracellular milieu might be responsible for the changes in dye behavior in the cell. To address this question, preliminary experiments with cell-free buffers compared the pattern seen inside the cell with quenching by a protein (bovine serum albumin; BSA) or that due to ethanol. The BSA result was completely unlike the intracellular case in that the protonated form of the dye was quenched. Buffer containing ethanol, on the other hand, was able to mimic the essential features of the intracellular spectra.
Developing a sealant program: the Massachusetts approach.

This paper describes the program structure and strategies being used by the Massachusetts Department of Public Health to promote the utilization of sealants. The program design includes four components: clinical demonstration, consumer education, professional education, and reimbursement. Eighteen Massachusetts neighborhood health centers and six local health departments are participating in the clinical demonstration component. Since March 1984, dental personnel from these sites have applied sealants to 4,398 schoolchildren. The promotional theme “Save Teeth: Seal Them” has been incorporated into brochures designed to increase knowledge and awareness of consumers. Curriculum materials have been developed to educate dentists and dental hygienists to apply sealants and understand the rationale and scientific basis for their use. Since January 1984, 18 sealant educational sessions have been conducted statewide for 630 dental providers. Information is being presented to third-party carriers, some of whom have subsequently adopted a policy to include reimbursement for sealants.
Time-Resolved Resonance Raman Study of HbA with 220 nm Excitation: Probing Phenylalanine

This study explores different UV wavelengths for the resonant Raman excitation of hemoglobin in its two affinity states (T and R). Changes in the T − R difference spectra as a function of excitatio...
Three decades of research in bacterial photosynthesis and the road leading to it: A personal account

In this minireview I present a very personal account of my life and research in bacterial photosynthesis. It is divided into two parts. The first part is autobiographical and narrates the events that led me to change fields from electrical engineering to physics and ultimately to biophysics. The second part describes the work on the primary processes in bacterial photosynthesis carried out with numerous collaborators in our laboratory over the past 30 years.
Nerve conduction velocity, microscopic, and electron microscopy studies comparing repaired adult and baby monkey median nerves

Three to three and a half years after repair of monkey nerves, comparison of total myelinated nerves, electron microscopic sections, and nerve conduction velocities delineated no significant difference between nerves sutured in adult life and those sutured in infancy. Extrapolating these results to the human clinical situation, central nervous system adaption in young patients could explain the better clinical results.
Prey resource use by coexistent hydromedusae from Friday Harbor, Washington

Prey selection patterns were quantified for a sympatric group of hydromedusae from Friday Harbor, WA. Selection patterns varied between species, but were largely replicable between sample dates and resembled dietary patterns found in similar studies from neighboring regions. Ambush-foraging medusae (Aglantha digitale, Sarsia tubulosa, and Proboscidactyla flavicirrata) fed primarily on crustacean and ciliated prey but the dietary niches of these hydromedusan species centered on different fractions of the available plankton. Consequently, little dietary overlap occurred between the ambush foraging hydromedusae. In contrast, the dietary niches of cruising predators (Aequorea victoria, Mitrocoma cellularia, and Phialidium gregarium) overlapped substantially because those species all fed on similar soft-bodied prey such as eggs and appendicularians. These results have two important implications for trophic patterns involving medusae. First, different mechanisms of prey encounter and capture used by hydromedusae (ambush vs. cruising patterns) result in important interspecific dietary differences and, hence, trophic roles of the medusae. Second, whereas cruising medusae may consume similar prey and hence form a feeding guild, ambush-foraging medusae may experience substantially less prey overlap and, for the community examined here, do not experience potentially strong feeding competition from other medusan species.