cssi/SciSciGPT-SciSciNet huggingface dataset:
GL n ( F q ) -analogues of factorization problems in the symmetric group

We consider GL n ( F q ) -analogues of certain factorization problems in the symmetric group S n : rather than counting factorizations of the long cycle ( 1 , 2 , ź , n ) given the number of cycles of each factor, we count factorizations of a regular elliptic element given the fixed space dimension of each factor. We show that, as in S n , the generating function counting these factorizations has attractive coefficients after an appropriate change of basis. Our work generalizes several recent results on factorizations in GL n ( F q ) and also uses a character-based approach.As an application of our results, we compute the asymptotic growth rate of the number of factorizations of fixed genus of a regular elliptic element in GL n ( F q ) into two factors as n ź ∞ . We end with a number of open questions.
The dynamics of electricity grid operation with increasing renewables and the path toward maximum renewable deployment

Abstract This paper presents an overview and analysis of the dynamics and unique impacts of variable renewables on the grid, and identifies the bottleneck problems and solutions associated with renewable integration. Variability issues that concern many are not unique to variable renewables. Grid operators have been dealing with demand variability for over a century. With sufficiently accurate forecast for variable renewables, the grid operators can schedule dispatchable generation and/or storage resources to balance demand and supply on a nearly real-time basis. With state-of-the-art wind forecasting technologies and existing generation resources, wind integration has not caused major operational problems for grid systems with a penetration level of up to 37% during some time intervals. Base load generators operate nearly constantly for days or longer and supply a larger share of the electricity mix than what is proportional to their capacity. This will be a limiting factor for high level variable renewables, if current operation continues. The capability to at least partially follow electricity load should be a key performance measure of non-renewable plants if we are serious about high level variable renewables. Specific policy instruments are recommended to incentivize more flexible plant operation and ensure smooth integration of variable renewables.
Heating Rate and Impossibility of Negative Refraction

I compute from first principles the local heating rate for electromagnetic waves propagating in magnetically and electrically polarizable media. The result indicates that the second law of thermodynamics prohibits negative refraction.
Outcome after operative treatment of intramedullary spinal cord tumors in adults : intermediate and long-term results in 51 patients

The reported results of treatment of intramedullary spinal cord tumors (IMSCT) are difficult to interpret because of heterogeneous management strategies, small numbers of patients, and short periods of follow-up. In 1985 we published the early results of operative treatment of 29 patients with IMSCT and were cautiously optimistic that aggressive operative management would have a salutary effect on long-term outcome. In this report, the most recent clinical status of these 29 original patients is reviewed along with that of 22 additional ones, to assess the intermediate and long-term results of treatment of IMSCT in 51 patients who underwent microsurgical resection between 1981 and 1987. Of these 51 patients, 24 had ependymomas, 18 had astrocytomas, and the remainder had a variety of less common lesions. Thirty-seven patients survive and have been followed for periods up to 72 months (mean 38 months). The neurological conditions of 21 patients are improved or have stabilized following operation. The conditions of 16 patients are worse postoperatively: 11 from operation and 5 from progression of disease. Eight patients are neurologically intact, 7 walk independently but abnormally, 9 ambulate with the aid of a cane or walker, and the remaining 13 are not ambulatory. Twelve of 18 patients with astrocytomas and 2 of 24 patients with ependymomas have died after a mean survival of 10 months from operation. Patients with ependymomas who had gross total resection have fared the best, with no deaths or recurrences, but no relationship could be discerned between the extent of resection and outcome in patients with astrocytomas.(ABSTRACT TRUNCATED AT 250 WORDS)
Mini-FDPM and heterodyne mini-FDPM: handheld non-invasive breast cancer detectors based on frequency-domain photon migration

This paper describes a handheld instrument for noninvasive detection of breast cancer based on a broad-band optical spectroscopy technique called frequency-domain photon migration (FDPM). It performs broad-band modulation on the intensity of near-infrared laser diodes and derives the scattering and absorption coefficients of the bulk tissue from phase and amplitude data measurements. Two different schematics of mini-FDPM were designed and fabricated. One is a homodyne structure that performs direct comparison of modulated and demodulated frequencies, and the other is a heterodyne structure that compares downconverted demodulated frequencies. The former has a simple structure but lower accuracy due to noise. The latter is more complex but more accurate due to the filtering of noise. The miniature size makes it possible to eliminate fiberoptic cables and enables direct contact between the laser diode and the tissue, making the instrument more power efficient while enhancing detection capabilities. Measurement results show that these miniature systems match or outperform the current prototype while costing two orders of magnitude less.
Partial vertical integration under market uncertainty

Abstract This paper shows that partial vertical integration arises in a market environment with risk-averse producers, cost and demand uncertainties, and production lag.
The consistency of one fixed omega

The paper “Partitions of Products” [DiPH] investigated the polarized partition relation The relation is consistent relative to an inaccessible cardinal if every α i is finite, but inconsistent if two are infinite. We show here that it consistent (relative to an inaccessible) for one to be infinite. Along the way, we prove an interesting proposition from ZFC concerning partitions of the finite subsets of ω .
Vasovagal Oscillations and Vasovagal Responses Produced by the Vestibulo-Sympathetic Reflex in the Rat

Sinusoidal galvanic vestibular stimulation (sGVS) induces oscillations in blood pressure (BP) and heart rate (HR) i.e., vasovagal oscillations, and decreases in BP and HR i.e., vasovagal responses, in isoflurane-anesthetized rats. We determined the characteristics of the vasovagal oscillations, assessed their role in the generation of vasovagal responses and determined whether they could be induced by monaural as well as by binaural sGVS and by oscillation in pitch. Wavelet analyses were used to determine the power distributions of the waveforms. Monaural and binaural sGVS and pitch generated vasovagal oscillations at the frequency and at twice the frequency of stimulation. Vasovagal oscillations and vasovagal responses were maximally induced at low stimulus frequencies (0.025-0.05 Hz). The oscillations were attenuated and the responses were rarely induced at higher stimulus frequencies. Vasovagal oscillations could occur without induction of vasovagal responses, but vasovagal responses were always associated with a vasovagal oscillation. We posit that the vasovagal oscillations originate in a low frequency band that, when appropriately activated by strong sympathetic stimulation, can generate vasovagal oscillations as a precursor for vasovagal responses and syncope. We further suggest that the activity responsible for the vasovagal oscillations arises in low frequency, otolith neurons with orientation vectors close to the vertical axis of the head. These neurons are likely to provide critical input to the Vestibulo-Sympathetic Reflex to increase BP and HR upon changes in head position relative to gravity, and to contribute to the production of vasovagal oscillations and vasovagal responses and syncope when the baroreflex is inactivated.
Comparative aphasiology: A cross-linguistic approach to language breakdown

(1989). Comparative aphasiology: A cross-linguistic approach to language breakdown. Aphasiology: Vol. 3, No. 2, pp. 111-142.
Gender inequality in education and employment in the scheduled castes and tribes of India

The complex stratification systems in India give rise to a multiplicity of social categories which often obscure the relative status of women and men within the more disadvantaged segments of the population. The focus of this study is on the situation of women in scheduled castes and tribes — groups which are referred to as ‘weaker sections of people’ and granted special safeguards and concessions under the Indian constitution. Women in these under-privileged groups are doubly disadvantaged: their minority group status interacts with India's patriarchal culture to produce deplorable living conditions. Drawing from both ethnographic and statistical sources, the paper presents a descriptive profile of scheduled caste and tribe women's status in Indian society. Using Indian Census data, the study documents extreme degrees of gender inequality among the scheduled groups. Findings indicate that relative to men, women in these groups have far more limited access to both educational and employment resources. This research also suggests that socioeconomic development serves to reduce the disadvantage of scheduled group women relative to men. Among the scheduled groups considered to be more developed according to standard indicators, findings indicate less gender inequality in education and employment.
Techniques for pollution monitoring in remote sites: II. Ozone

An O3 monitoring system for use in remote sites lacking AC line power was developed. A chemiluminescent O3 monitor, ethylene delivery system, and a DC power supply were combined to allow unattended O3 measurements over extended periods of time. A Campbell Scientific 21X micrologger in combination with a relay was used to control the ethylene delivery solenoid and O3 analyzer power, and to record results. The system was tested over a six week period in late summer 1990 and gave results comparable to those from surrounding sites.
Pulse chirping in a Nd:YAG laser

The 1.06-μm output of a loss-modulation mode-locked and frequency-doubled Nd:YAG laser was examined using a microwave avalanche photodiode with a rise time of ∼40 ps, and a scanning Fabry-Perot. The pulses were found to be transform limited only in the case where the 0.53-μm output of the laser was suppressed. When conversion efficiency was restored, the spectrum exhibited narrowing, but the pulses were much wider than the transform limit, indicating the presence of chirping.
Current assessment practices for noncancer end points.

The need for assessing noncancer risks for agents to which humans are routinely exposed indoors arises from the large amount of time spent indoors (i.e., employed persons spend about 60% of their t...
Processing Deep-Sea Particle-Rich Water Samples for Fluorescence In Situ Hybridization: Consideration of Storage Effects, Preservation, and Sonication

Particles are often regarded as microniches of enhanced microbial production and activities in the pelagic ocean and are vehicles of vertical material transport from the euphotic zone to the deep sea. Fluorescence in situ hybridization (FISH) can be a useful tool to study the microbial community structures associated with these particles, and thus their ecological significance, yet an appropriate protocol for processing deep-sea particle-rich water samples is lacking. Some sample processing considerations are discussed in the present study, and different combinations of existing procedures for preservation, size fractionation sequential filtration, and sonication were tested in conjunction with FISH. Results from this study show that water samples should be filtered and processed within no more than 10 to 12 h after collection, or else preservation is necessary. The commonly used prefiltration formaldehyde fixation was shown to be inadequate for the rRNA targeted by FISH. However, prefiltration formaldehyde fixation followed by immediate freezing and postfiltration paraformaldehyde fixation yielded highly consistent cell abundance estimates even after 96 days or potentially longer storage. Size fractionation sequential filtration and sonication together enhanced cell abundance estimates by severalfold. Size fractionation sequential filtration effectively separated particle-associated microbial communities from their free-living counterparts, while sonication detached cells from particles or aggregates for more-accurate cell counting using epifluorescence microscopy. Optimization in sonication time is recommended for different specific types of samples. These tested and optimized procedures can be incorporated into a FISH protocol for sampling in deep-sea particle-rich waters.
Automatic particle sizing from rocket motor holograms

Solid-propellant rocket fuels frequently have spherical aluminum pellets added to improve combustion efficiency and to improve thrust performance. In order to model the combustion process, information is required about the size of the particles as they lift off of the propellant surface. We have used optical pulsed-laser holography to record an approximate 2.5 cm X 2.5 cm X 2.5 cm volume at the propellant surface in a test rocket motor. A pulsed ruby laser, combined with a laser line filter to remove the flame light, records the hologram. A diffuser is used to remove the phase gradients introduced by the thermal effects in the flame. The scene is reconstructed with a krypton laser, viewed with an optical microscope, and captured on videotape. The recorded scene is digitized and analyzed with digital image processing techniques on a personal computer equipped with a video memory board and an image processing subroutine library. The image processing techniques developed reduce the speckle in the scene, apply a threshold to differentiate the particles from the background, and locate and size the particles. Statistical analysis of the sizing results provides a histogram representation of the particles size distribution. Particle resolution down to 10 micrometers has been achieved with this technique.
Impaired cytosolic free calcium response in splenic T-cells from mice fed with ethanol-containing diet.

Abstract Calcium-dependent signal transduction pathways of T-cell proliferation have been extensively studied in the past years. However, little is known about effects of ethanol on the calcium-dependent signal transduction pathway in T-cell proliferation. Thus, a murine model was used to determine effects of ethanol in vivo on T-cell proliferation and the intracellular free calcium concentration [Ca 2+ ] i in response to Concanavalin A (Con A) and recombinant IL2 (rIL2) in T-cells. Splenic cells from young C57BL/6 mice, that had been fed on 3 different diets (ethanol-, maltose substitute- and standard liquid-diet) for 7–8 weeks were tested for their proliferative responses to Con A and rIL2. Concurrently, measurement was also made of [Ca 2+ ] i in the nylon-wool-enriched resting T-cells induced by Con A and in Con-A-activated blast T-cells induced by rIL2. Our results showed that [Ca 2+ ] i increases were seen in the splenic T-cells from three different groups of mice following Con A, but not rIL2 stimulation. However, this increase was much smaller in the splenic T-cells from ethanol-fed mice as compared to mice on maltose- or standard-diet. Furthermore, we also demonstrated that the impaired [Ca 2+ ] i increase was seen in the T-cells of the same ethanol-fed mice having decreased the proliferative response to Con A. This reduced proliferation did not result from the presence of excessive suppressor T-cell activity. Finally, we also demonstrated that both the number of IL2 binding sites/cell and the K d values of the low- and high-affinity IL2R on the T-cells from ethanol-fed mice were unaltered. Because evidence indicates that (1) a normal level of [Ca 2+ ] i increase is a prerequisite for the production of IL2 by mitogen-stimulated T-cells, and (2) T-cells from ethanol-fed mice have normal capacities to produce IL2 that is the crucial growth factor controlling T-cells to progress through the cell cycle, these lines of evidence taken together with the results of this study suggest that the impairment in [Ca 2+ ] i increases in T-cells from ethanol-fed mice may not be the primary factor contributing to the diminished T-cell proliferation in the same mice.
In vitro activity and in vivo evaluation of ticarcillin plus clavulanic acid against aerobic and anaerobic bacteria

Abstract The efficacy of ticarcillin plus clavulanic acid was compared with that of certain broad-spectrum antibiotics such as ticarcillin, azlocillin, and piperacillin against blood culture Isolates of aerobic bacteria obtained from seriously ill patients and anaerobic bacteria obtained from other miscellaneous infections. Ticarcillin plus clavulanic acid was found to be as effective as other broad-spectrum antibiotics against most of the 285 septicemic isolates tested. Ticarcillin plus clavulanic acid was most effective against 351 anaerobic bacteria, including B. fragilis. Further, 32 strains of B. fragilis that were relatively resistant to ticarcillin and azlocillin were tested with a mixture of ticarcillin or azlocillin, each in combination with clavulanic acid. Ticarcillin plus clavulanic acid Inhibited all 32 strains of B. fragilis. Addition of clavulanic acid to cephalothin, penicillin, or azlocillin also augmented the antibiotic activity against B. fragilis by 4- to 64-fold. These in vitro data suggest that ticarcillin plus clavulanic acid may be used as a single antibiotic in the cases of bacterial septicemias and that the combination may be used in the treatment of multiple-antibiotic-resistant bacterial strains. In a related study, the augmentation activity of clavulanic acid with penicillin or ticarcillin was evaluated against B. fragilis in a rat intra-abdominal abscess model. Gelatin capsules filled with a mixture of B. fragilis and Escherichia coli were implanted intraperitoneally in male Wistar rats. Four different groups of animals with appropriate controls were treated with penicillin or ticarcillin alone or in combination with clavulanic acid. Treatment was started immediately or delayed for 48 hours after peritoneal soilage. The mortality rate decreased by almost one half when antibiotic therapy was started immediately. Treatment with ticarcillin plus clavulanic acid resulted in a cure in 70 to 89 percent of animals, showing that this combination is the most effective regimen in the treatment of rats with experimental intra-abdominal abscesses caused by B. fragilis and E. coli.
Insurance status and access to urgent ambulatory care follow-up appointments.

ContextThere is growing pressure to avoid hospitalizing emergency department patients who can be treated safely as outpatients, but this strategy depends on timely access to follow-up care.ObjectiveTo determine the association between reported insurance status and access to follow-up appointments for serious conditions that are commonly identified during an emergency department visit.Design, Setting, and ParticipantsEight research assistants called 499 randomly selected ambulatory clinics in 9 US cities (May 2002–February 2003) and identified themselves as new patients who had been seen in an emergency department and needed an urgent follow-up appointment (within 1 week) for 1 of 3 clinical vignettes (pneumonia, hypertension, or possible ectopic pregnancy). The same person called each clinic twice using the same clinical vignette but different insurance status.Main Outcome MeasureProportion of callers who were offered an appointment within a week.ResultsOf 499 clinics contacted in the final sample, 430 completed the study protocol. Four hundred six (47.2%) of 860 total callers and 277 (64.4%) of 430 privately insured callers were offered appointments within a week. Callers who claimed to have private insurance were more likely to receive appointments than those who claimed to have Medicaid coverage (63.6% [147/231] vs 34.2% [79/231]; difference, 29.4 percentage points; 95% confidence interval, 21.2-37.6; P<.001). Callers reporting private insurance coverage had higher appointment rates than callers who reported that they were uninsured but offered to pay $20 and arrange payment of the balance (65.3% [130/199] vs 25.1% [50/199]; difference, 40.2; 95% confidence interval, 31.4-49.1; P<.001). There were no differences in appointment rates between callers who claimed to have private insurance coverage and those who reportedly were uninsured but willing to pay cash for the entire visit fee (66.3% [132/199] vs 62.8% [125/199]; difference, 3.5; 95% confidence interval −3.7 to 10.8; P = .31). The median charge was $100 (range, $25-$600). Seventy-two percent of clinics did not attempt to determine the severity of the caller’s condition.ConclusionsReported insurance status is associated with access to timely follow-up ambulatory care for potentially serious conditions. Having private insurance and being willing to pay cash may not eliminate the difficulty in obtaining urgent follow-up appointments.
Dynamic evolution of economically preferred facilities

Abstract In a sustained development scenario, it is often the case that an investment is to be made over time in facilities that generate benefits. The benefits result from joint synergies between the facilities expressed as positive utilities specific to some subsets of facilities. As incremental budgets to finance fixed facility costs become available over time, additional facilities can be opened. The question is which facilities should be opened in order to guarantee that the overall benefit return over time is on the highest possible trajectory. This problem is common in situations such as ramping up a communication or transportation network where the facilities are hubs or service stations, or when introducing new technologies such as alternative fuels for cars and the facilities are fueling stations, or when expanding the production capacity with new machines, or when facilities are functions in a developing organization that is forced to make choices of where to invest limited funding. An intuitive strategy frequently used to evolve the set of facilities is a greedy approach that picks additional facilities which provide a highest rate of return on each budget increment. Such strategy is shown to have adverse impact by locking the system into future suboptimal solutions with total benefit that can be arbitrarily small compared to the optimal evolution sequence. It is shown here that the degree of suboptimality of such greedy strategy is extreme in that it can lead to the loss of the majority of future benefits. The main result here is the generation of the entire efficient frontier of optimal solution sets for different budget levels. This frontier contains information that guides the schedule of the optimal evolution of the set of facilities in future expansions. It is demonstrated that the efficient frontier forms a concave envelope, and the configurations on the frontier’s breakpoints are nested. The efficient frontier is generated by efficient and strongly polynomial algorithms. For n potential facility locations and for subsets of positive benefits of total size m we find the breakpoints of the efficient frontier using a parametric minimum cut procedure in time O ( nm log n 2 m ) , and all N configurations on the efficient frontier in time O( mn log n + N ).
Peptide-Mediated Lipofection Is Governed by Lipoplex Physical Properties and the Density of Surface-Displayed Amines

Peptides can potentiate lipid-mediated gene delivery by modifying lipoplex physiochemical properties to overcome rate-limiting steps to gene transfer. The objectives of this study were to determine the regimes over which cationic peptides enhance lipofection and to investigate the mechanism of action, such as increased cellular association resulting from changes in lipoplex physical properties. Short, cationic peptides were incorporated into lipoplexes by mixing peptide, lipid and DNA. Lipoplexes were characterized using gel retardation, dynamic light scattering, and fluorescent microscopy, and the amount of surface-displayed amines was quantified by fluorescamine. Size, zeta potential, and surface amines for lipoplexes were dependent on peptide/DNA ratio. Inclusion of peptides in lipoplexes resulted in up to a 13-fold increase in percentage of cells transfected, and up to a 76-fold increase in protein expression. This transfection enhancement corresponded to a small particle diameter and positive zeta potential of lipoplexes, as well as increased amount of surface-displayed amines. Relative to lipid alone, these properties of the peptide-modified lipoplexes enhanced cellular association, which has been reported as a rate-limiting step for transfection with lipoplexes. The addition of peptides is a simple method of lipofection enhancement, as direct chemical modification of lipids is not necessary for increased transfection.
Microstructural and crystallographic surface changes after grinding zirconia-based dental ceramics

The purpose of this study was to evaluate microstructural and crystallographic phase changes after grinding 3Y-TZP dental ceramics. Ceramic blanks were sintered according to manufacturer's recommendations and divided into four groups: (A) as-sintered control, (B) diamond-ground manually under water, (C) ground and polished, and (D) ground and annealed at 1000 degrees C for 1 h. Bulk specimens were analyzed by X-ray diffraction to characterize the crystalline phases. The microstructure was investigated by SEM. XRD analyses showed that the control group and the group that was ground and annealed contained only tetragonal zirconia. However, after grinding or after grinding followed by polishing, rhombohedral zirconia and strained tetragonal zirconia were present, without any detectable amount of monoclinic zirconia. Annealing led to the disappearance of both residual lattice strain and the rhombohedral phase. The microstructure of the ground and polished specimens was characterized by significant residual surface damage associated with grain pullout to a depth of about 20 microm. This type of damage could have an impact on the long-term fatigue behavior of 3Y-TZP.
Hormonally medicated IUDs.

Medicated IUDs represent a considerable improvement over inert IUDs; they can better control bleeding pain and expulsion and can be used as a carrier of antifertility compounds. The 1st medicated device the Copper T was associated with lower rates of pregnancy expulsion and removal but bleeding and pain remained. In 1969 the 1st progesterone-releasing IUD was presented; it released approximately 300 mcg of progesterone daily and produced endometrial changes not conducive to implantation. The 1st clinical report on the use of a progesterone-releasing IUD was in 1974. The device released 128 mcg/day of progesterone over a 6 month period; there were no pregnancies with 1600 women/months of use. Subsequent investigations done with Progestasert a new IUD releasing 38 mg of progesterone daily showed a low pregnancy rate 1.8 in parous and 2.4 in nulliparous women; a continuation rate of 79.5 and 70.4 respectively and a marked decrease in the incidence of dysmenorrhea and in menstrual flow. A double-blind randomized study compared results with Copper 7 and Progestasert on parous women; there were no significant differences with the exception of continuation rates at 12 months of use or 84.6 and 87.2 respectively. Also 50% of the Progestasert group reported a decrease in menstrual flow and only 10% reported an increase. Another study done to quantify blood loss with Copper 7 200 and with Progestasert showed with the 1st device a 65-76% increase in blood loss and with the 2nd device a 40-43% decrease. One of the drawbacks of Progestaert is its life span of 1 year only. A new generation of Progestasert devices has been tested; they contain 52 mg of progesterone and release it for more than 2 years at a dose of 38 mg daily with equal effectiveness. Progesterone-releasing IUDs do not seem to be responsible for the apparent increase in ectopic pregnancies. Norgestrel-releasing IUDs at a dose of 50 mcg daily have been shown to cause suppression of ovulation and irregular bleeding patterns; norgestrel IUDs are estimated to have a useful life of 7 years. A levonorgestrel-medicated IUD and the Nova-T copper device were compared after 12 months of use. Pregnancy rate was 0.3 and 2.6 and expulsion rate was 1.9 and 4.5 respectively; removal rate was 15.3% and 5.5% and continuation rate was 82.8% and 87.5%. Estriol-relasing IUDs have very recently been tested on laboratory animals; they clearly seemed to inhibit blastocyst development and implantation; no effect on spontaneous ovulation or ovum fertilization was noted. There were no changes in menstrual blood loss when the device was tested on volunteers and ovulation was preserved.
Thyroid status influences rat serum but not brain TRH pyroglutamyl aminopeptidase activities.

Serum and brain cytosol contains pyroglutamyl aminopeptidase activity that converts TRH to His-ProNH2 (TRH PAPase). Whereas serum TRH PAPase has specificity for TRH, this is not the case for brain cytosol PAPase. Recent reports indicate that a brain membrane fraction contains TRH PAPase that is specific for TRH and has a remarkable similarity to serum TRH PAPase. In the present studies, a method for measuring serum TRH PAPase activity and the activities of the membrane and cytosol brain TRH PAPase enzymes are described, the effect of thyroid status on these different TRH PAPase activities was determined. In hypothyroid rats serum TRH PAPase activity was decreased, whereas in rats treated with supraphysiological doses of T4 it was increased. In contrast, the cytosolic and the membrane TRH PAPase enzymes in brain were not affected by thyroid status. It is concluded that the membrane-associated brain TRH PAPase differs from the serum TRH PAPase in terms of its response to thyroid hormone. In addition, the pr...
Quinolone Therapy for Infections of the Central Nervous System

The rationale for use of quinolones in the treatment of central nervous system (CNS) infections is reviewed. Quinolones exert potent activity in vitro against many gram-negative meningeal pathogens. Given the concentrations attained in cerebrospinal fluid (CSF), however, activity against gram-positive organisms is marginal. As a group, the quinolones enter (penetrate) the CSF better than do any other class of antimicrobial agents. The percentage penetration into CSF is remarkably similar in animal models and in humans with meningitis receiving concurrent therapy. The relative rank order for CSF penetration is as follows: enoxacin and pefloxacin (approximately 50%) greater than ciprofloxacin and ofloxacin (approximately 20%-30%). Certain quinolones have proven to be equivalent to conventional agents (e.g., third-generation cephalosporins) in the rate with which they eradicate bacterial gram-negative organisms from the CSF in experimental animal models of meningitis, but the serum concentrations have usually been higher than those achieved in humans. Despite these advantages, the concentrations in CSF remain low (e.g., ciprofloxacin, approximately 0.25-0.5 mg/L; pefloxacin, 4-8 mg/L) in humans because of the relatively low concentrations attained in serum. Thus, quinolones will continue to be most useful in the treatment of infections due to problem pathogens or to multiresistant pathogens (e.g., Pseudomonas species). Although quinolones appear to enter brain tissue readily, it is unlikely that they can be used as single agents for the treatment of brain abscess because of poor activity against anaerobes and streptococci, and no animal or human studies have been reported. A single dose of ciprofloxacin administered orally appears promising for use in eradication of the meningococcal carrier state.
A constant composition kinetics study of the influence of salivary cystatins, statherin, amylase and human serum albumin on hydroxyapatite dissolution

Abstract The influence of salivary cystatins, statherin, amylase and human serum albumin on the dissolution kinetics of hydroxyapatite has been investigated using the constant composition method. At a pH of 6.0, salivary cystatins and statherin all decreased the dissolution rate by about 30% at a surface concentration of 5.0 × 10 −8 mol m −2 . Although little difference between neutral cystatin SN and acidic cystatin S was seen at pH 6.0, when the reaction was performed at a similar degree of undersaturation at neutral pH (6.95), cystatin S was the more efficient inhibitor. At a surface concentration of 5.0 × 10 −8 mol m −2 , cystatin SN and cystatin S decreased the rates of dissolution by 35% and 30% at pH 6.0 and by 40% and 65% at a pH of 6.95 respectively. Human serum albumin and amylase were more efficient dissolution inhibitors than either of these salivary cystatins at pH 6.0 and 4.8. Moreover, in all cases the influence of the adsorbed proteins increased with extent of reaction.
An improved holder for the electrochemical quartz crystal microbalance and its cyclic voltammetry characteristics

The design and characteristics of a stationary, compact holder for an electrochemical quartz crystal microbalance (EQCM) are presented. A Au/quartz crystal oscillator is vertically mounted in a polytetrafluoroethylene body of the holder. The crystal is sealed with an O-ring and is easily accessible for change. The performance of the holder was tested under cyclic voltammetry (CV) conditions with the Ag+ /Ag and Cu+ /Cu electrodeposition/electrodissolution processes. Frequency changes due to mass changes of the Au/quartz electrode were correlated with CV parameters. The holder was calibrated for a 5 MHz crystal oscillator by means of CV anodic stripping of silver. The mass sensitivity was 19.5 ± 0.1 ng Hz−1 cm−2. The concentration sensitivity was 14.2 ± 0.2 μM Hz−1 cm−2 at a potential scan rate of 0.01 V s−1 and 23.7 ± 0.3 μM Hz−1 cm−2 at a scan rate of 0.02 V s−1 for a potential of scan reversal which was 250 mV more negative than the electrodeposition peak potential.
Neurotransmitter release from non-neuronal cells

Abstract Recent advances in the study of membrane trafficking in eukaryotic cells have revealed that the basic machinery for exocytosis may be conserved in cells as diverse as neurons and yeast. Understanding how neurotransmitters can be secreted by non-neuronal cells may help to understand the role of neuronal specific proteins in regulating neurotransmitter secretion and the biogenesis of regulated secretion pathways in neurons.
Band structure effects in the heat capacity of adsorbed helium

Departures from two-dimensional ideal gas behavior in the low density heat capacity of ^3He and ^4He adsorbed on graphite are shown to be due to two-dimensional tunneling bands.
Changes in phospholipid composition in hibernating ground squirrel, Citellis lateralis, and their relationships to membrane function at reduced temperatures.

The hearts of hibernating mammals have the capacity to function at reduced temperatures of 1 C in contrast to hearts of nonhibernating mammals which undergo ventricular fibrillation during deep hypothermia. Thus, all vital membrane functions continue in hibernators. This suggests that there may be special features of their lipid and protein composition. Analysis of the hearts of the hibernating ground squirrel,Citellus lateralis, in the active (37 C) and hibernating state (1–4 C) reveals differences in the percent composition of the phospholipid classes. There is a decrease in the percentage of diacyl choline, ethanolamine, serine phosphoglycerides, and diphosphatidyl glycerol and an increase in the percentage of lysophosphatidyl choline, lysophosphatidyl ethanolamine, lysodiphosphatidyl glycerol, and phosphatidic acid in the hibernating state. There is also an increase in the molar amount of phosphorus/100 g fresh wt of tissue during hibernation. The most striking difference in phospholipid composition between active and hibernating heart tissue is the 3.5-fold increase in lysoglycerophosphatides. These compounds are implicated as contributing factors controlling membrane fluidity during hibernation and upon which the physiological state of hibernation may be contingent.
The dependence of performance on grating tilt in an ion-exchanged waveguide add/drop multiplexer

Optical add/drop multiplexers (OADM) based on asymmetric y-branches and tilted gratings can be easily fabricated using ion exchange techniques and photosensitive glasses. These devices offer excellent operating characteristics. However, optimum OADM performance depends critically on the angle of the tilted grating. In this paper, results from fabrication and modeling are compared for the ion exchange process using four different angles of the tilted grating. The transmission spectra for the fabricated and simulated OADMs show an excellent agreement.
On limit states of a linearized Boltzmann equation

With methods of mean ergodic theory a very simple criterion for existence of limit states of linearized Boltzmann equation is proven.
Mechanisms of salt scaling

A great deal of information has been collected over the years about the phenomenology of salt scaling of concrete, and no single mechanism has been identified that can account for all of the observations. We review the essential facts that any complete theory of scaling must explain, and suggest two mechanisms that seem to be of primary importance. Experiments indicate that damage is worst when the water on the surface of the concrete contains a small amount of solute, regardless of the type of solute. We argue that the role of solute is to create brine pockets in the ice that act as mechanical flaws; when the weakened ice cracks, the crack runs to the surface of the concrete and does superficial damage. An analysis of the stresses created in this way shows that they are more than sufficient to initiate cracks. A second phenomenon, which is present when chloride salts are used, is expansion resulting from precipitation of Friedel's salt. The crystallization pressure from growth of these crystals causes significant expansion of the paste, and results in high stresses on a local scale near the ice/paste boundary. This can substantially weaken the material and facilitate scaling.
Effects of Coulomb Interactions on the Landau Diamagnetism

The diamagnetic susceptibility of an electron gas is reduced by Coulomb interactions below the Landau value in proportion to $\ensuremath{\epsilon}\ensuremath{\beta}{{\ensuremath{\kappa}}_{0}}^{2}$, where $\ensuremath{\epsilon}$ is the plasma parameter, ${\ensuremath{\kappa}}_{0}$ is the Debye screening constant, and $\ensuremath{\beta}=\frac{1}{\mathrm{kT}}$.
Police gang intelligence infiltrates a small city

Abstract Research indicates that the spread of gangs into small cities is rarely due to a deliberate, drug-motivated gang migration. Still, outside police accounts of such a gang migration adversely affected the small city of Bloomington, Indiana. Tracing newspaper reports, as well as analyzing other secondary data, I find that an infiltration of outside police ideas about migrating and dangerous gangs led to militant police conduct that negatively affected the city of Bloomington more than outside, or even local, gang members. My research suggests that militarized police tactics motivated by the spread of ideas about urban gangsters may endanger the social order. The implications of a zero tolerance stance on crime in a democracy is also addressed.
Copulatory behavior in relation to anatomical characteristics of three macaques

Anatomy of copulatory organs and patterns of copulatory behavior were studied in three species of Macaca. The copulatory behavior of the rhesus monkey (M. mulatta) and crab-eating macaque (M. fascicularis) were similar. Mounting time was longer in stump-tailed macaque (M. arctoides) (48 seconds) than in the rhesus monkey or crab-eating macaque (8.5 seconds). Species differences were correlated with anatomical differences in the female and male reproductive organs. In the stump-tailed macaque the male has a relatively long penis, and the female has an elaborate vestibular colliculus in the vestibule. Both rhesus and crab-eating macaques have a short penis, and the female has no vestibular colliculus. Under scanning electron microscope, cone-like projections (3–4 mm) were observed on the surface of the glans and corpus penis of M. arctoides. In M. fascicularis shorter projections (0.05–0.1 mm) were observed on the glans penis but not the corpus penis.
Effects of calcium overload on relaxation in cultured heart cells.

Abstract Effects of alterations in transsarcolemmal sodium and calcium gradients on relaxation and calcium content were studied in spontaneously contracting tissue cultured monolayers of chick embryo ventricular cells. Cell wall motion during relaxation could be resolved into two kinetic phases. The first phase was rapid, with a time constant, τ 1 , of 30 to 40 ms and presumably reflects Ca uptake by sarcoplasmic reticulum. The second phase had a longer time constant, τ 2 , which varied under different experimental conditions from 50 to 200 ms. Cell wall motion during this second phase of relaxation continued until the next contraction occurred. At high external Ca, τ 1 and τ 2 were prolonged, coincident with a marked increase in Ca content as determined by 45 Ca labelling. Reduction of the transsarcolemmal Na gradient by external substitution of NaCl with choline chloride, by increasing internal [Na] by exposure of the cells to 5 μg/ml veratrine, or by exposure to ouabain (10 −5 m ), also prolonged τ 1 and τ 2 and increased cellular Ca content. These findings suggest that Ca overload in cultured heart cells can occur as a consequence of altered NaCa exchange, and can result in marked but reversible impairment of relaxation.
Raf-1: a kinase currently without a cause but not lacking in effects.

Recent studies of the molecular mechanisms of signal transduction have highlighted four molecules as potential secondary signal transducers for receptor tyrosine kinases. These are phospholipase C-γ, GTPase activating protein, type I phosphoinositide kinase and Raf-1. Recent work on the daf-1 gene of Caenorhabditis elegans raises the possibility that, in at least some cases, extracellular signals can activate Raf-1 family members directly. In this minireview we will discuss what is not known concerning Raf-1 and related molecules, why the unknowns are important to our understanding of signal transduction, and how genetic studies in invertebrates may provide new meanings to investigate these issues.
A discrete analogue of the Dirac operator and the discrete modified Novikov--Veselov hierarchy

We construct a discrete analogue of the integrable two-dimensional Dirac operator and describe the spectral properties of its eigenfunctions. We construct an integrable discrete analogue of the modified Novikov-Veselov hierarchy. We derive the first two equations of the hierarchy and give explicit formulas for the eigenfunctions in terms of the theta functions of the associated spectral curve.
Structurally colored thiol chitosan thin films as a platform for aqueous heavy metal ion detection.

Thin films of the polysaccharide chitosan and several chitosan derivatives, including conjugates of l-cysteine, thioglycolic acid, and 2-iminothiolane, were produced from dilute acidic solutions. Attempts to produce a fourth conjugate using lipoic acid resulted in the synthesis of partially N-acetylated chitosan ethanoate. These biopolymer films were exposed to solutions containing 50 ppm concentrations of various metal ion and counterion analytes. Analyte-induced changes in film thicknesses and refractive indices were measured using a spectroscopic ellipsometer, and shifts in film color were quantified using a reflectance spectrometer. The modified chitosans were generally more sensitive to change in response to pure water but also showed varied response to several ions of interest, including Cr(III) and Cr(VI), Hg(II), Ni(II), and others. The potential for tuning film response was demonstrated by varying the concentration of sulfur groups in the thioglycolic acid conjugate, leading to increased specific...
Water Transfer and Distribution Schemes

ABSTRACT Wherever water is needed, solutions have been sought to bring it to cities, industries, and dry fertile lands. Large water transfer schemes have a long history dating back thousands of years. In modern times, water transfer projects have been built in several countries, including Israel. They have found wide interest and have drawn attention to similar solutions for the Middle East. The gradual transformation of transfer schemes into large-scale distribution networks has found less attention. In Israel and, to a lesser extent, in Jordan extensive distribution systems bring water over large distances from various sources to the main consumption centers. The advantages of these networks include the possibility of balancing supply and demand over large distances, of pooling the financial resources of communities and regions, of sharing important structures such as reservoirs and treatment facilities, and providing greater security against local supply failures. It is suggested that consideration sho...
Polarized X-ray emission spectroscopy

Abstract Strongly polarized X-ray fluorescence from gas-phase molecules has been observed by selectively exciting near core-level ionization thresholds using monochromatized synchrotron radiation. Both the degree and the direction of the polarization are very sensitive to the incident excitation energy, and the symmetry of the occupied and unoccupied molecular orbitals involved in the excitation/fluorescence process. Illustration of the phenomenon will be made using Cl K-edge excitation on the molecule methyl chloride, CH 3 Cl. The possibility of extracting orientational, geometrical, and orbital-symmetry information directly from experiment will be discussed, and the importance of the rapid time scale of the X-ray fluorescence decay (≈ 10 fs), which effectively precludes disorientation effects, will be stressed. Expectations are that polarized X-ray emission spectroscopy will enjoy wide applicability to, for example, solids, surfaces and interfaces, oriented molecules such as surface adsorbates, and active sites in macromolecules.
Incremental Validity of Cognitions in a Clinical Case Formulation: An Intraindividual Test in a Case Example

Incremental validity, the ability of a measure to predict or explain variance over and above other measures, is an important psychometric characteristic of standardized measures, but has received little attention idiographically. Idiographic assessment may be an important part of developing a clinical case formulation, guiding treatment by developing an individualized understanding of the variables that trigger and maintain distress. This study examined whether the idiosyncratic cognitive schema hypothesized by a clinician in a cognitive case formulation explained distress incrementally over that of situational triggers. Using daily ratings of situational triggers, idiosyncratic cognitions, and distress, the incremental validity of cognitions in predicting each of six distress measures was tested in a case example using dynamic time series regression. The incremental variance explained by cognitions varied across the distress measures, suggesting that, in this case example, targeting thoughts and beliefs for treatment may be important for only certain types of distress.