cssi/SciSciGPT-SciSciNet huggingface dataset:
Getting started with yeast.

Publisher Summary The yeast Saccharomyces cerevisiae is now recognized as a model system representing a simple eukaryote whose genome can be easily manipulated. Yeast has only a slightly greater genetic complexity than bacteria and shares many of the technical advantages that permitted rapid progress in the molecular genetics of prokaryotes and their viruses. Some of the properties that make yeast particularly suitable for biological studies include rapid growth, dispersed cells, the ease of replica plating and mutant isolation, a well-defined genetic system, and most important, a highly versatile DNA transformation system. Being nonpathogenic, yeast can be handled with little precautions. Large quantities of normal baker's yeast are commercially available and can provide a cheap source for biochemical studies. The development of DNA transformation has made yeast particularly accessible to gene cloning and genetic engineering techniques. Structural genes corresponding to virtually any genetic trait can be identified by complementation from plasmid libraries. Plasmids can be introduced into yeast cells either as replicating molecules or by integration into the genome. In contrast to most other organisms, integrative recombination of transforming DNA in yeast proceeds exclusively via homologous recombination. Cloned yeast sequences, accompanied by foreign sequences on plasmids, can therefore be directed at will to specific locations in the genome.
Poacher detection at fence crossing

Poachers profit from the illegal trade of animal parts. Elephants and rhinoceros are often the target of poachers. In South Africa areas of private reserves agreed to drop fences bordering Kruger National Park. At same time they keep fences that don't boarder the park. Poachers are crossing these fence lines. This paper discusses a work in progress to develop sensors to detect poachers as they cross the fence line.
Is Voting Habit Forming? New Evidence from Experiments and Regression Discontinuities

Field experiments and regression discontinuity designs test whether voting is habit forming by examining whether a random shock to turnout in one election affects participation in subsequent elections. We contribute to this literature by offering a vast amount of new statistical evidence on the long-term consequences of random and quasi-random inducements to vote. The behavior of millions of voters confirms the persistence of voter turnout and calls attention to theoretically meaningful nuances in the development and expression of voting habits. We suggest that individuals become habituated to voting in particular types of elections. The degree of persistence appears to vary by electoral context and by the attributes of those who comply with an initial inducement to vote. [ABSTRACT FROM AUTHOR]
Revascularization in Severe Left Ventricular Dysfunction

The highest-risk patients with heart failure with reduced ejection fraction are those with ischemic cardiomyopathy and severe left ventricular systolic dysfunction (ejection fraction≤35%). The cornerstone of treatment is guideline-driven medical therapy for all patients and implantable device therapy for appropriately selected patients. Surgical revascularization offers the potential for improved survival and quality of life, particularly in patients with more extensive multivessel disease and the greatest degree of left ventricular systolic dysfunction and remodeling. These are also the patients at greatest short-term risk of mortality with coronary artery bypass graft surgery. The short-term risks of surgery need to be balanced against the potential for long-term benefit. This review discusses the evolving data on the role of surgical revascularization, surgical ventricular reconstruction, and mitral valve surgery in this high-risk patient population.
Extending Big‐Five theory into childhood: A preliminary investigation into the relationship between Big‐Five personality traits and behavior problems in children

An investigation was conducted to link Big-Five personality traits with behavior problems identified in childhood. Eighty-six children ranging in age from 9 to 13 were rated by their respective classroom teacher using an experimental ratings instrument developed to measure Big-Five personality constructs and behavior concurrently. Big-Five Personality and Behavior Problem scales were correlated. Results show distinct patterns of behavior problems associated with various personality characteristics. Children with low scores in Agreeableness and Conscientiousness exhibit social problems, conduct problems, attention deficits, and hyperactivity. Children with low scores on the scale, Openness to Experience, exhibit problems in social behavior, conduct, and attention. The Neuroticism trait was associated with anxiety and depression. Potential implication for clinical practice and future research study was provided. These preliminary data indicate that identifying Big-Five personality trait patterns may be a useful dimension of assessment for understanding underlying motives and predispositions associated with children's problem behavior. © 1999 John Wiley & Sons, Inc.
Accumulation of CO2 in reservoir devices during simulated neonatal mechanical ventilation

Aerosolized albuterol is frequently administered to mechanically ventilated neonates by metered dose inhaler (MDI) and a reservoir device. These reservoirs are often placed between the Y-piece and endotracheal tube, thereby creating mechanical dead space and increasing the risk of rebreathing carbon dioxide (CO(2)). The objectives of this study were: 1) to quantify CO(2) accumulation in two commonly used reservoirs (ACE(R), Aerochamber(R)-MV) and a bidirectional nonreservoir actuator (Airlife(R) Minispacer) during mechanical ventilation of a neonatal lung model; and 2) to determine the effect of tidal volume (V(T)) on CO(2) accumulation. We hypothesized that the accumulation of CO(2) in these devices is clinically insignificant at the small tidal volumes used in mechanically ventilated premature neonates. The model was constructed to simulate CO(2) exhalation by a ventilated neonate and consisted of a neonatal ventilator circuit (rate = 40/min; peak inspiratory pressure (PIP) = 20 cm H(2)0) attached to a reservoir/actuator and neonatal test lung. The ventilator delivered inspiratory gas (room air) to the test lung, which was vented into the atmosphere by a small adjustable leak. Expiration was simulated by manually ventilating 7.1% CO(2) (partial pressure of CO(2) (PCO(2)) = 48 mm Hg) back through the model. Accumulation of CO(2) within the reservoir/actuator was measured using an end-tidal CO(2) monitor. Each 4-min experiment was conducted at three V(T) (7.5 mL, 15 mL, and 25 mL), and the median PCO(2) was calculated in 0.5-min increments. For V(T) = 7.5 mL, CO(2) accumulated slowly in the ACE(R) and Minispacer(R) and reached a maximum at 4.0 min (PCO(2) = 2.3 mm Hg and 7.3 mm Hg, respectively). In contrast, the Aerochamber(R)-MV rapidly reached a PCO(2) of 9.5-10.0 mm Hg by 1-1. 5 min. A similar trend occurred with V(T) = 15 mL; however, higher partial pressures (approximately 10-12 mm Hg) were achieved with all devices. At V(T) = 25 mL, PCO(2) rose rapidly with the ACE(R), Aerochamber(R)-MV, and Minispacer(R), reaching peaks of 17.2, 12.3, and 20.3 mm Hg, respectively (P < 0.05). In conclusion, accumulation of CO(2) in reservoir/actuator depends on V(T) as well as the chamber design and internal volume. Due to the short duration of use when administering drugs via MDI, accumulation of CO(2) in these devices is not likely to be clinically relevant for the majority of ventilated newborns.
Picosecond sources for sub-centimeter laser ranging

Some of the tradeoffs involved in selecting a laser source for space-based laser ranging are outlined, and some of the recent developments in the laser field most relevant to space-based lasers for ranging and altimetry are surveyed. Laser pulse width and laser design are discussed. It is argued that, while doubled/tripled ND-host lasers are currently the best choice for laser ranging in two colors, they have the shortcoming that the atmospheric transmission at 355 nm is significantly poorer than it is at longer wavelengths which still have sufficient dispersion for two-color laser ranging. The life requirement appears to demand that laser diode pumping be used for space applications.
Understanding the Microdynamics of Farm Structural Change: Entry, Exit, and Restructuring among Wisconsin Family Farmers in the 1980s1

Abstract Despite many differences among competing theories of agrarian transformation, all tend to presume that aggregate structural changes are essentially a reflection of changes taking place on individual farms over time. This presumption has been reinforced by a reliance on aggregated county-level census data or cross-sectional surveys of individual farm operations, which unfortunately afford few opportunities to test conventional assumptions about the underlying dynamics of the process. Given the large gross flows into and out of the farm sector, this paper examines the question: do aggregate structural changes primarily result from adaptations made on continuing farms, or are they the product of selective entry and exit processes? Data from a panel study of Wisconsin farmers are used to shed light on the micro-dynamics of structural change. The results suggest that continuing farmers often adapt in ways very different from aggregate trends. They also demonstrate how the character of entry and exit patterns is critical to the structural change process.
Early diagenesis of amino acids and organic matter in two coastal marine sediments

Abstract Surface sediments of Buzzards Bay, Massachusetts (BBP) are oxic to suboxic and are extensively bioturbated by deposit-feeding infauna, while sediments of the Pettaquamscutt River Estuary, Rhode Island (PRE) are reducing and overlain by anoxic bottom water. Sediments from these two sites were analyzed for total organic carbon and nitrogen, total hydrolyzable amino acids, dissolved free amino acids, and porewater dissolved organic carbon, ammonium, total carbon dioxide, and sulfide, to describe and compare the early diagenesis. Based on model calculations, organic matter remineralization rates in the upper meter of BBP and PRE sediments are of similar magnitude, at 14 and 10 g C/m2· year, respectively. The surface sediment organic carbon accumulation rates at the two sites are also similar, 36 (BBP) and 30 (PRE) g C/m2 · year. Thus, the unusually high organic content of PRE sediments (>12% by weight organic carbon) does not result from much greater deposition rates or from much lower decomposition rates than in BBP sediments, which contain only 2% organic carbon. Total hydrolyzable amino acids made up 11 to 23% of the total carbon remineralized in BBP sediments. Decomposition did not result in detectable changes in hydrolyzable amino acid composition at either site. Glutamic acid and β-aminoglutaric acid were major constituents of the sediment dissolved free amino acids. Dissolved free amino acid distributions in these sediments are probably the net result of production and consumption by bacteria. Macrofauna and adsorption to sediments are additional sinks for dissolved amino acids in Buzzards Bay sediments, but they do not appear to be responsible for the major features of the dissolved free amino acid distributions.
Automated classification of basal cell carcinoma in mouse skin by polarization sensitive optical coherence tomography

An automated, support-vector-machine classifier was developed to discriminate basal cell carcinoma from healthy mouse skin images obtained with polarization sensitive optical coherence tomography. The results demonstrate that polarization sensitive optical coherence tomography has the potential to achieve accurate diagnosis of skin cancer noninvasively.
Combinatorial Gene Therapy to Inhibit HIV: Improving Therapeutic Efficacy by Targeting Multiple Stages of the HIV-1 Replication Cycle Simultaneously

In these studies, we tested the effectiveness of combinatorial gene delivery to CCR5-expressing cell lines and primary cells to enhance resistance to HIV-1 infection. The transgenes used were chosen both to decrease membrane CCR5 and to inhibit HIV-1 replication, and were delivered using Tag-deleted SV40-derived vectors. rSV40s are very effective in transducing primary T cells and T cell lines. SV(RNAiR5), SV(RevM10.AU1) and SV(RNAiR5/RevM10.AU1) respectively deliver a small interfering RNA (siRNA) against CCR5, RevM10, to which a C-terminal AU1 epitope was added and which inhibits HIV-1 Rev, or both transgenes together. We used human cell lines (SupT1 and SupT1/CCR5) and primary human monocyte-derived macrophages (MDMs). We assessed RevM10 expression by flow cytometry (FACS). After transduction, we confirmed expression of each transgene by flow cytometry (FACS). Simultaneous delivery of both transgenes in a bifunctional vector protected both SupT1/CCR5 cells and MDMs from R5 tropic HIV-1Ba-L, better than either the monofunctional vectors, SV(RNAiR5) and SV(RevM10.AU1) individually. The bifunctional vector also protected from X4-tropic HIV-1, comparably to SV(RevM10.AU1). SV(RNAiR5) did not protect from X4-tropic HIV-1. Thus, combining these two transgenes in one vector protected from X4-tropic HIV-1 and provided enhanced protection for CCR5-bearing cells from R5-tropic strains of HIV-1. Combinatorial genetic therapy, by targeting of more then one HIV-1 function, may provide effective inhibition of HIV-1 replication.
The Relevance of Tillich for the Theology and Science Dialogue

This paper explores the relevance of the theology of Paul Tillich for the contemporary dialogue with the natural sciences. The focus is on his Systematic Theology, volume I. First I discuss the general relevance of Tillich's methodology (namely, the method of correlation) for that dialogue, stressing that a genuine dialogue requires cognitive input from both sides and that both sides find “value added” according to their own criteria (or what I call the method of “mutual creative interaction”). Then I move specifically to a Tillichian theological analysis of twentieth-century theoretical science and its empirical discoveries, including Big Bang, inflationary, and quantum cosmologies, quantum physics, thermodynamics, chaos and complexity, and molecular and evolutionary biology, suggesting how they relate to such Tillichian themes as finitude and the categories of being and knowing (time, space, causality, and substance) and to Tillich's understanding of such symbols as God, freedom and destiny, creation, and estrangement. In doing so, my intention is to provide a point of departure for further extended analyses of Tillich's theology in relation to contemporary natural science.
Infrared observation of transistor current distribution during operation in the quasi-saturation regime

The current gain of transistors with wide, lightly doped collectors is is known to fall off during high current, low voltage operation. This "two-level saturation" effect, sometimes known as "quasi-saturation", has been attributed by some authors to a current density-induced widening of the base into the collector, and by others to lateral current injection at high current densities. In this paper we describe the results of experiments designed to determine whether or not lateral current injection is significant during quasi-saturation. In our experiments, the band-to-band radiative recombination observed between the base and emitter metallization in the course of transistor operation was used to determine the current distribution. This infrared radiation was observed using a very sensitive S-1 image tube fibre-optically coupled to a SIT TV camera. On the basis of the current distributions observed in a variety of transistors, we concluded that lateral injection is not the dominant factor in establishing a quasi-saturation regime.
Thiolation with inversion at secondary positions during fragmentation-rearrangement of sugar dithiobis(thioformates)☆

Abstract Cyclic dithiobis(thioformates) derived from vicinal trans -diols decomposed upon pyrolysis or upon treatment with methyl sulfoxide containing catalytic amounts of base to give O,S -dithiocarbonates with accompanying inversion at the site of thiolation. With derivatives of vicinal cis -diols, fragmentation led only to thionocarbonates and the parent diols. Cyclic dithiobis(thioformates) of methyl 4,6- O -benzylidene-α- D -glucopyranoside, 1,2:5,6-di- O -isopropylidene- D -mannitol, and trans -1,2-cyclohexanediol decomposed to O,S -dithiocarbonates; whereas the dithiobis-(thioformates) of methyl 4,6- O -benzylidene-α- D -mannopyranoside and cis -1,2-cyclo-hexanediol decomposed only to thionocarbonates and the corresponding diols. The structures of the O,S -dithiocarbonates were confirmed by physical and chemical data.
Space domain constraints for least squares restoration of images degraded by atmospheric turbulence

The residual image is analyzed to determine a constraint which regularizes the ill-posed least squares image restoration problem. The energy in the residual image is constrained at a level which depends on the noise statistics, image degradation, and restoration method. This constraint is applied individually to different image subregions, to find different regularizations appropriate in each subregion. This defines a spatially variant restoration method, even for a spatially invariant image degradation. Least squares image restoration methods using this constraint are applied to an artificial image which has been degraded by simulated long-exposure atmospheric turbulence and random noise. Quantitative analysis of the restored image shows significant improvement with this constraint, in comparison to the usual constraint on residual energy which depends only on noise statistics.
Light-weight black-box failure detection for distributed systems

Detecting failures in distributed systems is challenging, as modern datacenters run a variety of applications. Current techniques for detecting failures often require training, have limited scalability, or have results that are hard to interpret. We present LFD, a light-weight technique to quickly detect performance problems in distributed systems using only correlations of OS metrics. LFD is based on our hypothesis of server application behavior, does not require training, and detects failures with complexity linear in the number of nodes, with results that are interpretable by sysadmins. We further show that LFD is versatile, and can diagnose faults in Hadoop MapReduce systems and on multi-tier web request systems, and show how LFD is intuitive to sysadmins.
Effects of antiotensin applied electrophoretically on lateral hypothalamic neurons

Abstract The effects of angiotensin II applied by means of electrophoresis through multibarreled glass capillary electrodes on the extracellularly recorded discharge frequencies of brain cells were determined. A total of 148 neurons in 21 female hooded rats anesthetized with urethan and chloralose were tested. Results indicate two types of neurons within the lateral hypothalamus (LH) which are affected differently by angiotensin II; those of the medial forebrain bundle (LH-MFB) which increase in discharge frequency, and another type at the ventral border of the LH which decrease in discharge frequency. Neurons of the zona incerta were similar to those of the medial forebrain bundle. All of the Na sensitive cells of the LH-MFB and the zona incerta were also sensitive to angiotensin II. Neurons of the LH, LH-MFB and zona incerta have a relatively low threshold to angiotensin II. At higher doses the effect appears to be more nonspecific and one third of the thalamic cells tested also responded. Only one of the 13 neurons in the cerebral cortex was affected. Angiotensin II in small quantities might therefore influence drinking because of a specific effect on Na sensitive neurons of the LH.
Catalysis and the nature of mixed-metal oxides at the nanometer level: special properties of MOx/TiO2(110) {M= V, W, Ce} surfaces

To rationalize structure-reactivity relationships for mixed-metal oxide catalysts, well-defined systems are required. Studies involving the deposition of nanoparticles and clusters of VO(x), CeO(x) and WO(x) on TiO(2)(110) and other well-defined oxide surfaces have shown novel structures that have special chemical properties. Dimers of vanadia and ceria have been found on TiO(2)(110), monomers of vanadia on CeO(2)(111), and (WO(3))(3) clusters on TiO(2)(110). The V[double bond, length as m-dash]O or W[double bond, length as m-dash]O groups present in VO(x)/TiO(2)(110), VO(x)/CeO(2)(111) and WO(x)/TiO(2)(110) surfaces dislay a very high activity for the selective oxidation of alkanes and the dehydrogenation of alcohols. The non-typical coordination modes imposed by TiO(2)(110) on ceria nanoparticles make possible the direct participation of this oxide in catalytic reactions and enhance the dispersion of metals on the titania substrate. Au/CeO(x)/TiO(2)(110) surfaces display an extremely high catalytic activity for CO oxidation and the water-gas shift reaction. In general, the chemical behavior of the MO(x)/TiO(2)(110) {M = V, Ce or W} surfaces reflects their unique structure at the nanometer level. These simple models can provide a conceptual framework for modifying or controlling the chemical properties of mixed-metal oxides and for engineering industrial catalysts.
Relation between blood groups and resistance to infection with influenza and some picornaviruses.

SPECIFIC immunity, especially that conferred by antibody on the respiratory mucosa, is probably the most important factor in resistance to infection with respiratory viruses1–3. But McDonald and Zuckermann4 have shown that in the first wave of Asian influenza relatively more RAF men admitted to hospital with this infection were of blood group O than of blood group A.
A novel real-time system to monitor cell aggregation and trajectories in rotating wall vessel bioreactors

Rotating wall vessel bioreactors (RWVs) constitute dynamic suspension culture venues for tissue engineering. Quantitative real-time assessment of the kinetics of cell-cell aggregation in RWVs can yield mechanistic information about the initial steps leading to the assembly of individual cells into tissue-like constructs. In our imaging system, fluorescently labeled cells suspended in a HARV-type RWV were irradiated by a laser-beam. Emission was recorded by a camera mounted at 90 degrees to the excitation plane. Using macro lenses, the system identified approximately 5 microm particles from a 5 cm working distance, distinguished aggregated 20 microm microspheres from larger (45 and 90 microm) microspheres, and plotted local trajectories of microspheres and cells. Sizes of PC12 cells assessed by our system matched conventional measurements. We validated the system's ability to follow HepG2 and PC12 aggregation in real time over 24h of RWV culture. Taken together, our system provides the means to measure and analyze in real time the processes that lead to the 3D tissue-like assembly of diverse cell types into spheroids. Future studies include development of intelligent feedback algorithms, allowing automatic control over RWV rotational speed required to maintain aggregating cells and nascent tissue in continual free fall.
Presidential Vision or Congressional Derision? Explaining Budgeting Outcomes for NASA, 1958–2008

This study examines presidential-congressional relations on appropriations for the National Aeronautics and Space Administration (NASA). The objective is to examine differences between presidential requests and congressional appropriations for NASA spanning fiscal years 1959–2009. The analysis accentuates NASA's exceptional situation in the budgeting process as an agency without a core social or geographic constituency, the impact of congressional budget reforms, and presidents’ relative inattention to space policy since the agency's inception in 1958. The theoretical basis for the quantitative analysis also draws from perspectives that include domestic economic factors, international contexts, and the congressional electoral cycle. The empirical analysis accentuates the basis for congressional dominance over the agency's funding.
Effects of calcium-channel blockers on myocardial preservation during experimental acute myocardial infarction.

Abstract Calcium antagonists have become accepted agents for the attenuation of myocardial ischemia when it becomes manifest as angina pectoris. However, it is not known whether these agents can protect ischemic myocardium during the early evolution of an acute myocardial infarct. Calcium antagonists could potentially improve myocardial perfusion, by relieving coronary spasm or improving collateral blood flow, and reduce the energy demands of the ischemic myocardium either directly or by reducing heart rate or contractility. In some studies, calcium antagonists have decreased the rate of adenosine triphosphate depletion in ischemia and reduced functional or structural indexes of ischemic injury after relatively brief periods (up to 2 hours) of injury. We have assessed the ability of verapamil to protect severely ischemic myocardium in dogs with a 40-minute test period of circumflex occlusion followed by reperfusion. After 4 days of recovery, infarcts were sized by histologic methods. Untreated dogs had subendocardial infarcts (the more moderately ischemic subepicardial region being salvaged by reperfusion). Pretreatment with verapamil reduced the size of these subendocardial infarcts from 34 ± 8 to 8 ± 3 % of the ischemic circumflex vascular bed (anatomic area at risk). Thus, verapamil prevented cell death in a substantial proportion of the severely ischemic subendocardial region that otherwise would have died as a result of the 40-minute test period of ischemia. To establish whether verapamil could prevent cell death for a longer period of time in the less severely ischemic subepicardial region, a 3-hour period of coronary occlusion with reperfusion was studied. This period of occlusion caused infarcts averaging 60 ± 6 % of the ischemic area at risk in untreated dogs. Dogs treated with verapamil 15 minutes after occlusion and throughout the remaining 165 minutes of the 3-hour test period had no limitation of infarct size (53 ± 3 % of the area at risk). In untreated dogs, infarct size was related inversely to baseline subepicardial collateral flow. Verapamil neither improved collateral flow nor altered the regression of infarct size versus blood flow. Thus, the early protective effect of pretreatment with verapamil was not sustained when ischemia was prolonged to 3 hours and when verapamil was given 15 minutes after the onset of ischemia. In experimental studies from other laboratories, calcium antagonists have had either a protective effect or no effect when infarct size was evaluated after ≥3 hours of coronary occlusion. Preliminary results of clinical trials with calcium antagonists in acute myocardial infarction have not been encouraging. The available experimental data indicate that calcium antagonists can prevent ischemic cell death during relatively brief periods of ischemia if reperfusion is established, but it is uncertain whether these agents can limit infarct size when ischemia is maintained for longer periods.
Comprehensive DFT and MP2 Level Investigations of Reaction of 2,3-Dihydro-1,5-benzodiazepine-2-thiones with Hydrazine

Density functional theory approach was used for the 4-phenyl-2,3-dihydro-1,5-benzodiazepine-2-thione compound to determine the mechanism of hydrazinolysis of 4-substituted 2,3-dihydro-1,5-benzodiazepine-2-thiones. Single-point calculations at the MP2/6-311+G(d,p)//B3LYP/6-311+G(d,p) level were performed for the more accurate energy prediction. The solvent effect was taken into account by carrying out single-point calculations using the PCM methodology. The obtained results show that in the investigating mechanism the first step consists of the hydrazine molecule addition to the thiocarbonyl bond of the 4-phenyl-2,3-dihydro-1,5-benzodiazepine-2-thione following removal of H2S. Further addition of another hydrazine molecule to the azomethyne bond and cyclization with pyrazole ring formation occur, and then the diazepine ring-opening and the removal of hydrazine molecule proceed. Finally, imine−enamine tautomerization leads to 5-N-(2-aminophenyl-1-amino)-3-phenylpyrazole as a main product that is in agreemen...
Dugdale plastic zone size and CTOD equations for the compact specimen

With the aim of applying the Dugdale model to the compact specimen, the equations for stress intensity factor and crack surface displacement are obtained for a pair of pin loads and a uniform stress acting on a segment of the crack surface. The plastic zone size is calculated from the 'finiteness' condition of Dugdale, and the results agree well with collocation results from Terada (1983). The load that causes incipient yielding at the compression point of the compact specimen is calculated from a finite element strip yield analysis for an elastic-perfectly plastic material. The crack tip opening displacement for the compact specimen is calculated by adding the displacement at the tip of the physical crack length due to the pin load and due to the uniform stress. The results are within 1.5 percent of current collocation results.
Familial double pericentric inversion of chromosome 5 with some features of cri-du-chat syndrome

Fluorescence in situ hybridization analysis was performed to characterize a complex pericentric inversion involving chromosome 5 in a mother and son. The mother had hypertelorism, epicanthal folds, and mild mental deficiency while the son had additional anomalies that have been observed in patients with cri-du-chat syndrome. Both individuals were found to have an identical double pericentric inversion [inv5(p15.1g31(inv5(p14q12)))]. Neither inversion breakpoint mapped near the chromosomal regions implicated in the cri-du-chat syndrome. The phenotype of the son suggests that the inversion process may have affected the expression of some of the cri-duchat syndrome genes, suggestive of a genomic imprinting or penetrance effect.
The CD8 isoform CD8αα is not a functional homologue of the TCR co-receptor CD8αβ

Although structurally similar, CD8αβ and CD8αα have notably diverted with regard to function. Whereas CD8αβ functions as a T-cell receptor (TCR) co-receptor on MHC-class-I-restricted thymocytes and mature T cells, CD8αα is unable to support conventional positive selection, and can be expressed on T cells independent of the MHC restriction of their TCR. CD8αα induction is consistent with antigenic stimulation through the TCR, and recent developments have now shown that CD8αα induced on agonist-triggered immature thymocytes, antigenic-stimulated conventional CD8αβ T cells and mucosal T cells mediates the specific modulation of TCR activation signals to facilitate their survival and differentiation into various specialized T-cell subsets.
In vitro propagation of cultured human natural killer cells expressing the HNK-1 differentiation antigen and spontaneous cytotoxic function.

Human natural killer (NK) cells expressing the HNK-1 differentiation antigen were established in long-term tissue culture for over 3 months. The fluorescence-activated cell sorter-purified HNK-1+ cells required both phytohemagglutinin and exogenous interleukin 2 to propagate in long-term culture. After 2 weeks of culture, virtually all of the growing cells exhibited the surface membrane phenotype associated with immature HNK-1+ cells, since they simultaneously expressed the HNK-1, Leu-4 and Leu-2a but lacked the M1. Leu-3a and T6 antigens, and Fc gamma receptors. They exhibited a lymphoblastoid appearance, contained cytoplasmic granules, and exhibited spontaneous cytotoxic function against a broader spectrum of target cells than did fresh HNK-1+ cells from the same donor. Cultured HNK-1+ cells lacked antibody-dependent cell-mediated cytotoxic (ADCC) function, while fresh HNK-1+ were fully capable of ADCC function. On the other hand, cultured HNK-1- cells were lymphoblasts without cytoplasmic granules or NK cytotoxic function. The cultured HNK-1+ cells gradually lost their HNK-1 antigen expression over time, although the expression of other surface antigens (e.g., Leu-4 and Leu-2a) was unchanged. With prolonged culture (greater than 2 months), they also exhibited decreasing cytotoxic function and a diminished number of cytoplasmic granules. They were eventually indistinguishable from HNK-1- cells after 3 months of culture. These observations were not influenced by adding interferon-gamma to the cultures. The results demonstrate that the immature form of NK cells (that express T cell antigens) preferentially proliferate in long-term cultures when incubated with phytohemagglutinin and interleukin 2.
X-Ray Diffractometer for the Study of a Monomolecular Film Spread on a Liquid Substrate

The study of ultrathin films spread on liquid substrates has been limited to macroscopic observations of general film behavior. Synchrotron radiation has provided the means of observing the two-dimensional crystalline properties of monolayers. Our recent experiments performed on NSLS X-23B beam line was the trial run of a new liquid surface diffractometer. Major emphasis has been placed on vibrational and environmental isolation of the film, in addition to 0.1 micron resolution in the control of beam positioning. The film is examined in a closed, ultraclean environment consisting of a fused silica trough, purified N 2 atmosphere, 0.1°C temperature control and chromatography grade or better solvents and surfactants. Surface properties (surface tension, and visco-elastic moduli) are monitored by surface laser light scattering spectroscopy. The x-ray scattering pattern from the liquid surface contains the expected specular reflection as well as scattered peaks at small wave numbers. We believe these to be caused by high frequency surface ripple fields.
Repairing Ecological Processes to Direct Ecosystem State Changes

Ensuring that rangelands provide a rich array of eco- logical services into the future will require enduring efforts from research and management profession- als. This responsibility is particularly important for those charged with repairing lands impacted by invasive plant species, where attaining success is both dif cult and expen- sive. When ecosystems exist in a degraded invaded state, re- storing them to a preexisting state is not likely if foundational ecosystem attributes such as soil and site stability, hydrologic function, and biotic integrity have been drastically altered. It is important for land managers to determine the ecological status of a site prior to implementing restoration treatments. This process-based approach is taking precedence over one- sided emphasis on targeting a certain plant community com- position because it provides a clear linkage between measur- able ecological indicators and ecosystem services sought by a diverse group of stakeholders.1 Consequently, management efforts that seek to repair damaged processes or reestablish missing processes must rst understand feedback mecha- nisms operating within an invaded ecosystem state prior to applying restoration strategies. DOI: 10.2458/azu_rangelands_v34i6_monaco
Second moment scaling, metallic and covalent structure rationalization and electron counting rules

Abstract In this paper we review how a modified tight-binding method, which is based on second moment scaling of the electronic density of states, can be used to rationalize both crystal structure and electron counting rules. The electron counting rules considered are the Huckel 4 N + 2 rule, VSEPR model, the octet rule, Wade's rule for electron deficient clusters and the Hume-Rothery electron concentration rules for pure metals and alloys. We consider covalent and metallic structures based on elements from group 6 to group 17 of the periodic table. Finally we show how both the metallic and covalent bonding found in such systems can be placed into a single cohesive bonding picture. The method of moments proves useful in this analysis.
Novel photoconductive effect in spark-processed silicon with metal contacts

Spark-processed silicon (sp-Si) has been shown to display strong photoluminescence in the UV/blue and green spectral ranges. Furthermore, ferromagnetic behavior, electroluminescence and cathodoluminescence have been reported. The present contribution reports on a novel photoconductive effect, which has been observed in a simple device made from sp-Si. A symmetric device consisting of two metal contacts on sp-Si increases its electrical conductivity dramatically when the junction of the sp-Si and the anode contact is illuminated with UV or visible light. However, its conductivity decreases when the sp-Si/cathode contact junction is illuminated. The magnitude of both effects is proportional to the intensity of the light source, and is dependent on the wavelength of the light. There is no significant change in conductivity when the bulk of the sp-Si is illuminated. This behavior is unique and strikingly different than existing devices such as p-n, p-i-n, and Schottky diodes, as well as photoconductive devices, which all show an increase in conductivity in both directions when illuminated.
Changes of calcium channel characteristics and its relationship with pancreatic islet β cell parasecretion in rat born small for gestational age

Method The animal model of small for gestation in rat was made under matemal calorie restriction by 50% from d1 of gestation until term, while the control groups named AGA rats, were obtained from normal pregnant rats. Both of SGA and AGA newborn rats were fed normally till 4 weeks and 8 weeks. Single islet b cell isolation and pancreatic tissue-slice technique were used to obtain b cells in neonatal rats and adult rats, respectively. Using whole cell patch clamp to record the characteristics of b cell voltage dependent calcium channel (such as current, reversal potential, I-V curve, activation curve, inactivation curve) in both SGA and AGA groups. Using capacitance measurement induced by a sequence of sine wave stimulus to reflect the insu lin secretion. In aw ord, study the tendency of calcium channel kinetics and secretion property by timing. Results The membrane capacitance of SGA was smaller than AGA rat after excluding the influence of whole cell membrane capacitance deviation both in neonatal rats, 4 weeks and 8 weeks (P 0.05). The same result was obtained in activation curve and inactivation curve of calcium channel, whose half activated voltage/ half inactivated voltage V1/2 and slope factor k between SGA and AGA both showed no significant difference (P>0.05) ; 2) adult rats: there was no statistical difference found in all average calcium current density (Id), including the total calcium, L-type and T-type. No significant difference was observed in the peak current density of I-V curve in SGA and AGA (P>0.05). However, the reversal potential in SGA group was much lower than control (P<0.05). The two group had the same shape of activation curve and inactivation curve of calcium channel, and 50% activated voltage between SGA and AGA had no significant difference, but the calcium channel of SGA was easily to be closed, the inactivated voltage in SGA group was much higher than control (P<0.01). Conclusion The effect of intrauterine malnourishment on pancreatic isletbcell last in postnatal life and the destroy of bcell tends to aggravate with time. Low calcium current density on b cell membrane devotes to the decrease of b cell secretion in SGA neonatal rat. However, the current of calcium channel returns to normal level in childhood. The kinetics of calcium channel is changed significantly,
Biofilm formation on human airway epithelia by encapsulated Neisseria meningitidis serogroup B

Neisseria meningitidis is the etiologic agent of meningococcal meningitis. We compared 48-h biofilm formation by N. meningitidis serogroup B strains NMB, MC58, C311 and isogenic mutants defective in capsule formation on SV-40 transformed human bronchial epithelial (HBE) cells in a flow cell. We demonstrated that strains NMB and NMB siaA-D were defective in biofilm formation over glass, and there was a partial rescue of biofilm growth for strain NMB on collagen-coated coverslips at 48 h. We demonstrated all three serogroup B strains form biofilms of statistically equivalent average height on HBE cells as their isogenic capsular mutants. Strain NMB also formed a biofilm of statistically equivalent biomass as the NMB siaA-D mutant on HBE cells at 6 and 48 h. These biofilms are significantly larger than biofilms formed over glass or collagen. Verification that strain NMB expressed capsule in biofilms on HBE cells was demonstrated by staining with 2.2.B, a monoclonal antibody with specificity for the serogroup B capsule. ELISA analysis demonstrated that strains MC58 and C311 also produced capsules during biofilm growth. These findings suggest that encapsulated meningococci can form biofilms on epithelial cells suggesting that biofilm formation may play a role in nasopharyngeal colonization.
Real-time multiplex PCR assays.

The ability to multiplex PCR by probe color and melting temperature (T(m)) greatly expands the power of real-time analysis. Simple hybridization probes with only a single fluorescent dye can be used for quantification and allele typing. Different probes are labeled with dyes that have unique emission spectra. Spectral data are collected with discrete optics or dispersed onto an array for detection. Spectral overlap between dyes is corrected by using pure dye spectra to deconvolute the experimental data by matrix algebra. Since fluorescence is temperature dependent and depends on the dye, spectral overlap and color compensation constants are also temperature dependent. Single-labeled probes are easier to synthesize and purify than more complex probes with two or more dyes. In addition, the fluorescence of single-labeled probes is reversible and depends only on hybridization of the probe to the target, allowing study of the melting characteristics of the probe. Although melting curves can be obtained during PCR, data are usually acquired at near-equilibrium rates of 0.05-0.2 degrees C/s after PCR is complete. Using rapid-cycle PCR, amplification requires about 20 min followed by a 10-min melting curve, greatly reducing result turnaround time. In addition to dye color, melting temperature can be used for a second dimension of multiplexing. Multiplexing by color and T(m) creates a "virtual" two-dimensional multiplexing array without the need for an immobilized matrix of probes. Instead of physical separation along the X and Y axes, amplification products are identified by different fluorescence spectra and melting characteristics.
The origin and turnover rates of cerebrospinal fluid albumin and gamma-globulin in man ☆

Abstract The extent of equilibration of intravenously-injected [ 125 I]immunoglobulin-G (IgG) between serum and cerebrospinal fluid (CSF) was studied in patients with normal and selectively-elevated concentrations of IgG in CSF. CSF IgG appeared to be derived from serum IgG in those patients with normal lumbar fluid IgG concentration, while 37–88% of the CSF IgG was derived from an extravascular pool, presumably within the nervous system, in the patients with selectively-elevated IgG concentrations. The rate of flux of albumin and IgG into the entire CSF compartment was estimated during ventriculo-lumbar perfusion. Albumin influx was comparable in the control and elevated CSF IgG groups (0.086 mg/min and 0.100 mg/min, respectively). IgG influx was increased 6-fold in the elevated IgG group as compared with the control group (0.107 mg/min and 0.018 mg/min, respectively). The increased rate of influx of IgG was felt to represent the contribution to CSF of a pool of γ-globulin synthesized within the nervous system. The CSF pool size of albumin and IgG was estimated in 7 patients, from which values the fractional turnover rates of CSF albumin and IgG were calculated. The turnover rate constants for albumin (0.0035 min −1 ) and IgG (0.0036 min −1 ) agreed well with the turnover rate constant for net formation of CSF (0.0034 min −1 ), supporting the concept that proteins are removed from CSF during reabsorption of fluid in bulk.
Unidirectional Lasing Emerging from Frozen Light in Nonreciprocal Cavities

We introduce a class of unidirectional lasing modes associated with the frozen mode regime of nonreciprocal slow-wave structures. Such asymmetric modes can only exist in cavities with broken time-reversal and space inversion symmetries. Their lasing frequency coincides with a spectral stationary inflection point of the underlying passive structure and is virtually independent of its size. These unidirectional lasers can be indispensable components of photonic integrated circuitry.
Cobalt-induced polycythemia and survival of x-irradiated albino rats.

SummaryCobaltous chloride was incorporated in the diet of rats in the amounts of 0, 10, 20, 40, 70 and 100 ppm of added cobalt for a period of 19 weeks prior to whole-body x-irradiation and 6 weeks after. The various degrees of polycythemia which were thereby induced were measured indirectly by measuring the increases beyond the normal in hemoglobin concentrations. The ratio of the increase in hemoglobin concentration in each polycythemic group to the normal increase in 14 weeks was found to be directly proportional to the logarithm of the concentration (expressed in ppm) of added dietary cobalt. The rats with cobalt-induced higher concentrations of hemoglobin had an increased average rate of mortality after receiving 750 r whole-body x-irradiation? rather than a decreased rate, as compared with similarly irradiated control rats. Measurements of mucoprotein concentrations in the plasma revealed no significant differences between the various groups before irradiation, nor substantial changes at 48 hours af...
Simple method for the preparation of highly efficient polymer‐coated capillary electrophoresis columns

A simple method for the preparation of polymer-coated fused silica capillary columns for electrophoresis is presented. It is shown that the static coating technique used in GC and SFC can be conveniently utilized for the preparation of highly efficient capillary electrophoresis columns. In this method, the coating solution contains appropriate proportions of three ingredients: a polymer, a surface derivatization reagent, and a crosslinking reagent dissolved in a suitable low-boiling solvent. After coating, the column is subjected to heat treatment to immobilize the polymer film. Simplicity, rapidity, high column efficiency, batch-to-batch and run-to-run reproducibility, and long column life-time are advantageous features of the new method. Column efficiencies of as high as 1.2 million theoretical plates were achieved for cytochrome c on a 96 cm long Ucon 75 H-90,000 coated column. Efficient electrophoretic separation of five cytochrome c proteins was achieved on a Superox 4 coated column. The possibility of CE separation of histones on the new columns was also explored.
Synthesis of ether‐linked bisoxazolines and their use in step‐growth polymerization reactions with phenolics

Six new ether-linked bisoxazolines have been synthesized via reaction of p-hydroxyphenyl-2-oxazoline with dihalides. These bisoxazolines may be used as chain extenders or crosslinkers for resins, monomers or polymers containing various acidic groups, including phenolics, via step-growth (1 : 1) reactions. As an illustration, a phenol-formaldehyde polycondensate (Alnovol) and an enzyme oligomerized bisphenol A resin, as well as poly (p-hydroxystyrene), was chain extended and crosslinked to produce thermosets with high glass transition temperatures. The new bisoxazolines were also polymerized with diphenol compounds, such as diphone D and bisphenol P to generate linear or branched oligomers and polymers. Differential scanning calorimetry was used to evaluate the potential for polymerization and crosslinking reactions. Preliminary results showed that the new, ether-linked bisoxazolines have potential for formulating high performance thermosets. Copyright © 2002 John Wiley & Sons, Ltd.