cssi/SciSciGPT-SciSciNet huggingface dataset:
Proactive Intrusion Detection and Mitigation System: Case Study on Packet Replay Attacks in Distributed Energy Resource Systems

The electric grid is rapidly being modernized with novel technologies, adaptive and automated grid-support functions, and added connectivity with internet-based communications and remote interfaces. These advancements render the grid increasingly “smart” and cyber-physical, but also broaden the vulnerability landscape and potential for malicious, cascading disturbances. The grid must be properly defended with security mechanisms such as intrusion detection systems (IDSs), but these tools must account for power system behavior as well as network traffic to be effective. In this paper, we present a cyber-physical IDS, the proactive intrusion detection and mitigation system (PIDMS), that analyzes both cyber and physical data streams in parallel, detects intrusion, and deploys proactive response. We demonstrate the PIDMS with an exemplar case study exploring a packet replay attack scenario focused on photovoltaic inverter communications; the scenario is tested with an emulated, cyber-physical grid environment with hardware-in-the-loop inverters.
Heightened risk factors in the midst of the pandemic: Supporting individuals with psychosis during COVID-19.

Purpose This article aims to describe distinct vulnerabilities to the psychosocial stress from coronavirus disease 2019 (COVID-19) on individuals with psychosis and provide practical ways to reduce the vulnerabilities. Conclusion Societal changes and stress have come in the wake of the COVID-19. Individuals with psychosis are more susceptible to stress, cognitive biases, and lack social support. Practitioners working with individuals with psychosis are in a unique position to offer ways to reduce risk. Practice implications Care during the pandemic requires practitioners to pay particular attention to magnified risk factors to individuals with psychosis and create a plan to offer adjunct support.
Patient-Provider Communication Training Models for Interactive Speech Devices.

Patient-provider communication plays a major role in healthcare with its main goal being to improve the patient’s health and build a trustworthy relationship between the patient and the doctor. Provider’s efficiency and effectiveness in communication can be improved through training in order to meet the essential elements of communication that are relevant during medical encounters. We surmised that speech-enabled conversational agents could be used as a training tool. In this study, we propose designing an ontology-based interaction model that can direct software agents to train dental and medical students. We transformed sample scenario scripts into a formalized ontology training model that links utterances of the user and the machine that expresses patient-provider communication. We created two instance-based models from the ontology to test the operational execution of the model using a prototype software engine. The assessment revealed that the dialogue engine was able to handle about 62% of the dialogue links. Future direction of this work will focus on further enhancing and capturing the features of patient-provider communication, and eventual deployment for pilot testing.
Bilateral ureteral reimplantation at complete primary repair of exstrophy: Post-operative outcomes.

Extended Summary Background and Study Objective The value of bilateral ureteral reimplant (BUR) at the time of complete primary repair of bladder exstrophy (CPRE) has been suggested, however, outcomes are poorly characterized in current medical literature. We hypothesize that BUR at time of CPRE will decrease the rate of recurrent pyelonephritis, post-operative vesicoureteral reflux (VUR), and the need for subsequent ureteral surgery. Study Design We analyzed 64 consecutive patients with a diagnosis of classic bladder exstrophy (BE) who underwent CPRE at three institutions from 2013 to 2019. 15 patients underwent cephalotrigonal BUR-CPRE and 49 patients underwent CPRE alone. Our primary outcome was >1 episode of pyelonephritis as documented in the medical record. Secondary outcomes were persistent vesicoureteral reflux (VUR), with a sub-analysis of number of refluxing renal units and presence of dilating VUR, and the need for subsequent ureteral surgery. Descriptive statistics in addition to standard, two tailed univariate statistics, were used to compare the groups where appropriate. Results BUR-CPRE was associated with a significant decrease in the rates of post-operative VUR, number of refluxing renal units, and need for subsequent ureteral surgery (p=0.002, p=0.001, and p=0.048 respectively). There was a reduction in the rates of recurrent pyelonephritis and dilating reflux in patients undergoing BUR-CPRE, though it did not reach significance. Female gender was significantly associated with recurrent pyelonephritis regardless of BUR-CPRE status (p=0.005). There were no reports of distal ureteral obstruction or other complications following BUR-CPRE. The mean post-operative follow up for the BUR-CPRE group was 46.33 (10.26) months vs. 53.76 (26.05) months for CPRE, (p=0.11). Discussion Recurrent pyelonephritis following bladder closure in patients with BE is a well-documented surgical complication, with centers performing CPRE reporting rates of post-operative pyelonephritis from 22 to 50%. Our series demonstrates similar efficacy of BUR-CPRE compared to other contemporary series and provides additional detail about need for subsequent ureteral surgeries and increased long term follow-up of these complex patients. Limitations of the study include male predominance of the cohort and lack of randomization of BUR-CPRE. Conclusions BUR-CPRE decreases postoperative VUR and the need for additional ureteral surgery in select BE patients; it should be considered when technically feasible. While results continue to suggest a trend toward decreased recurrent pyelonephritis and dilating reflux, further longitudinal follow-up in our cohort will be needed.
White Christian Privilege: The Illusion of Religious Equality in America: By Khyati Y. Joshi, 2020. NYU Press, 256 pages, ISBN 1479840238, Hardcover, $31.00

The author presents an analysis of Khyati Y. Joshi’s White Christian Privilege. White Christian privilege aligns Christianity with Whiteness, and presents the impact of this dominant intersection i...
Exposure and response prevention therapy with cognitive defusion exercises to reduce repetitive and restrictive behaviors displayed by children with autism spectrum disorder

Abstract Repetitive and restrictive behaviors are disruptive in children with autism spectrum disorder. Exposure is an evidence-based approach to these problems and is hypothesized to work in part by enabling rule testing that undermines rule control. The present study undermined rule control more directly through cognitive defusion exercises. Experiment 1 used a multiple baseline across participants design to assess the effects of a cognitive defusion exercise in the form of word repetition and exposure on problem behavior associated with repetitive and restrictive behaviors observed in children with autism spectrum disorder. All 3 participants demonstrated a decrease in the percentage of problem behavior following the implementation of treatment which remained at near zero during a 3-month follow-up. Experiment 2 used an alternating treatments design to compare a cognitive defusion exercise and exposure to a control exercise and exposure. All except 1 of the participants displayed larger and quicker decreases in problem behavior during the cognitive defusion exercise condition compared to the control exercise condition. The results suggest that cognitive defusion exercises can enhance the treatment effects of exposure to decrease problem behavior associated with repetitive and restrictive behaviors.
Résumé of cardiac disease in pregnancy for a five-year period

Abstract This condition is found two to three times more frequently in females than in males. It is usually a congenital anomaly, though the adult type has been reported as a result of Streptococcus viridans infection. The lesion itself is a narrowing or constriction of the aorta in the region of the insertion of the ductus arteriosus or its vestige. In 25 per cent of these cases, the aortic valve is bicuspid. This gives rise to a narrowing of the lumen and thinning of the walls of a part or all of the aorta with a consequent reduction of the volume of blood flowing through it. This same thinning of the walls is evident in the cerebral vessels. Survival and capacity for work in such patients depend upon the establishment of collateral circulation through the anastomoses between aorta and subclavian, intercostal, and epigastric arteries. Its diagnosis rests upon symptoms and signs developing along this collateral circulation. These are in the order of their frequency and importance: 1. 1. Hypertension and high pulse pressure in the upper extremities both as compared to normal and to that of the lower extremities. 2. 2. Notching and erosion of the lower rib margins as seen in the x-ray 3. 3. Pulsations, thrills, bruits, and other sounds along the course of the collateral circulation. 4. 4. Gradually diminishing pulse volume as the terminal arteries of the lower extremities are approached. The greatest danger of pregnancy, and particularly labor, in these patients is sudden rupture of the thinned-out aorta or cerebral vessels. It is therefore usually advised that pregnancy be avoided by contraceptive devices, or if pregnancy has occurred despite these, interruption be done early. If the patient has been carried to near term, she should be delivered by cesarean section with tubal sterilization.
Generation of vascular cells from patient derived iPSC to model hypertension (LB537)

Since their establishment within the last decade, induced pluripotent stem cells (iPSC) have opened the possibility to model human diseases in vitro maintaining disease phenotypes as they are diffe...
The Bcl-2 Oncoprotein Functions as a Pro-oxidant

The mechanism by which the bcl-2 oncogene exerts its anti-apoptotic and antioxidant action is unknown. We found that expression of bcl-2 in superoxide dismutase-deficient (SOD-) Escherichia coli resulted in increased transcription of the KatG catalase-peroxidase, a 13-fold increase in KatG activity and a 100-fold increase in resistance to hydrogen peroxide. In addition, mutation rate was increased 3-fold, and katG and oxyR, a transcriptional regulator of katG induction, were required for aerobic survival. These data indicate that Bcl-2 acts as a pro-oxidant in E. coli, i.e. Bcl-2 generates reactive oxygen intermediates. In support of a pro-oxidant mechanism in eukaryotic cells, we found a 73% increase in superoxide dismutase activity in a murine B-cell line overexpressing Bcl-2. Increases in reduced glutathione and in oxyradical damage to DNA, previously observed in other overexpressing cell lines, are additional evidence for a pro-oxidant mechanism. Thus, Bcl-2 does not appear to be an antioxidant. Instead, Bcl-2 appears to influence levels of reactive oxygen intermediates that induce endogenous cellular antioxidants. This activity of Bcl-2 may control entry into apoptosis.
Fisher, Ronald A. (1890–1962)

Ronald Aylmer Fisher (1890–1962) was a mathematician and geneticist. He is primarily known for his singular contributions to the statistical and genetics revolutions of the twentieth century. There are no single adjectives to describe the magnitude of his contributions to statistical science and experimental methodology. His contributions to evolutionary theory and genetics were similarly extensive. Keywords: genetics; R.A. Fisher; statistical methods in psychology; research
Concept Selection Matrices

Concept selection matrices provide a way to evaluate and select among several alternative approaches, architectures, or solutions using a set of selection criteria. The selected alternative might be one of the alternatives considered or a new alternative generated or developed as a hybrid of several alternatives during the concept selection process (referred to as controlled convergence). The concept selection matrix and associated process of controlled convergence is illustrated with a nontechnical and a technical example. Weighted and categorized matrices are also briefly discussed. Keywords: concept selection; concept matrix; Pugh concept; Pugh approach; architecture selection; decision making; multiple criteria decisions
Application of spatial filters to DOA estimation of coherent sources

Problems associated with spatial smoothing which relate to the rate of decorrelation of correlated sources are discussed. Although a small improvement is attained, if sources have small differences in their directions-of-arrival (DOAs), they will remain highly correlated and the problem is not significantly diminished. A method which is based on the spatial filtering of an array vector is proposed. A procedure is developed that significantly reduces the correlations among sources and results in a nearly diagonal source covariance matrix. The design of the proposed spatial filters requires preliminary estimates of DOAs. This requirement, however, is not a drawback to this method, as is shown. Simulation studies are carried out for a 12-element linear array with quarter-wavelength element spacing. In all cases, 100 snapshots are used to estimate the array covariance matrix. In each case, 10 different simulations, with different noise sequences, are performed to present the variability of the resultant spectrum. The number of sources is set to 3 with -60 degrees , 30 degrees , and 40 degrees DOAs. >
Does the Organization of Emotional Expression Change Over Time? Facial Expressivity From 4 to 12 Months

Differentiation models contend that the organization of facial expressivity increases during infancy. Accordingly, infants are believed to exhibit increasingly specific facial expressions in response to stimuli as a function of development. This study tested this hypothesis in a sample of 151 infants (83 boys and 68 girls) observed in 4 situations (tickle, sour taste, arm restraint, and masked stranger) at 4 and 12 months of age. Three of the 4 situations showed evidence of increasing specificity over time. In response to tickle, the number of infants exhibiting joy expressions increased and the number exhibiting interest, surprise, and surprise blends decreased from 4 to 12 months. In tasting a sour substance, more infants exhibited disgust and fewer exhibited joy and interest expressions, and fear and surprise blends over time. For arm restraint, more infants exhibited anger expressions and anger blends and fewer exhibited interest and surprise expressions and surprise blends over time. In response to a masked stranger, however, no evidence of increased specificity was found. Overall, these findings suggest that infants increasingly exhibit particular expressions in response to specific stimuli during the 1st year of life. These data provide partial support for the hypothesis that facial expressivity becomes increasingly organized over time.
Patterns of food sharing among mother and infant chimpanzees at Gombe National Park, Tanzania.

The patterns of food sharing among mother and infant chimpanzees at the Gombe National Park, Tanzania, are primarily influenced by the infants’ ability to procure and process foods independently. Food
Self-Reported Dietary Changes With Respect To American Cancer Society Nutrition Guidelines (1982-1986)

Abstract A follow‐up study was conducted by the Illinois Division of the American Cancer Society (ACS) in conjunction with the ongoing National Cancer Prevention Study II (CPSII) to determine whether self‐report dietary changes are occurring in accordance with the ACS nutrition guidelines and to identify demographic subgroups that may be targeted for future prevention and education programs. A total of 42,300 CPSII respondents completed a 1986 questionnaire and were matched to 1982 baseline data. Dietary items were recorded as “on the average, how many days per week do you eat the following foods?” Individuals with known chronic conditions, body mass index outside a moderate range, and fewer than four completed food items were excluded. The remaining study population (n = 18,062) included men and women who were apparently healthy and primarily over the age of 50. The distribution of foods reported in 1982 and changes in foods consumed (1982–1986) among selected food groups varied modestly by sex, age, and...
Increasing Detection Range and Minimizing Polarization Mixing with Circularly Polarized Light through Scattering Environments.

We present both simulation and experimental results showing that circularly polarized light maintains its degree of polarization better than linearly polarized light in scattering environments. This is specifically true in turbid environments like fog and clouds. In contrast to previous studies that propagate single wavelengths through broad particle-size distributions, this work identifies regions where circular polarization persists further than linear by systematically surveying different wavelengths through monodisperse particle diameters. For monodisperse polystyrene microspheres in water, for particle diameters of 0.99 and 1.925 microns and varying optical depths, we show that circular polarization’s ability to persist through multiple scattering events is enhanced by as much as a factor of four, when compared to that of linear polarization. These particle diameters correspond to size parameters found for infrared wavelengths and marine and continental fog particle distributions. The experimental results are compared to Monte Carlo simulations for all scattering environments investigated.
Impacts of topology control on the ACOPF

Conventionally, transmission assets are treated as static assets for short-run operations. Topology control exploits the flexibility of the grid topology to allow for improvement in dispatch efficiency. While previous work on optimal transmission switching examines this concept in a DC setting, this paper examines transmission switching for the ACOPF and its impact on parameters like voltage magnitude and losses. A comparative analysis between optimal transmission switching in a DC setting and switching in an AC setting is also presented. Results indicate significant economic savings of up to 9% achieved by topology control.
Control of Listeria monocytogenes on ham steaks by antimicrobials incorporated into chitosan-coated plastic films

Contamination of ready-to-eat (RTE) meat products such as ham steaks with Listeria monocytogenes has been a concern for the meat processing industry. The objective of this study was to evaluate the antilisterial efficacy of chitosan-coated plastic films alone or incorporating five generally recognized as safe (GRAS) antimicrobials. Effect of chitosan-coated plastic film on the growth of L. monocytogenes was first investigated in an aqueous system of culture medium broth and chitosan-coated films were able to inhibit the growth of L. monocytogenes in a concentration-dependent manner. However, chitosan-coated plastic films were not able to control the growth of L. monocytogenes on ham steaks. Therefore, five GRAS antimicrobials were subsequently incorporated into chitosan-coated plastic films to enhance their antilisterial effectiveness. Ham steaks were surface-inoculated with a five-strain cocktail of L. monocytogenes and then packaged in chitosan-coated plastic films containing 500 IU/cm(2) of nisin, 0.01 g/cm(2) of sodium lactate (SL), 0.0025 g/cm(2) of sodium diacetate, 0.003 g/cm(2) of potassium sorbate (PB), or 0.001 g/cm(2) of sodium benzoate (SB). The samples were stored at room temperature (ca. 20 degrees C) for 10 days. Incorporating antimicrobials into chitosan-coated plastic films slowed down or inhibited the growth of L. monocytogenes. The chitosan-coated plastic film containing SL was the most effective antimicrobial film and its efficacy against L. monocytogenes on ham steaks was evaluated during 12-week storage at 4 degrees C. The film showed excellent long-term antilisterial effect with the counts of L. monocytogenes being slightly lower than the initial inoculum. Chitosan-coated plastic films containing 0.001 g/cm(2) of SL have a potential to be used on ham steaks to control L. monocytogenes.
Solvent Dependant Ligand Displacement and Anion Coordination in Selected Copper(I) Coordination Compounds

The crystal structure of the Cu(I) mixed ligand salt, [Cu(MeCN)2(PPh3)2](CF3SO3), 1, was determined using single crystal X-ray diffraction, a = 23.249(2), b = 26.665(1), c = 19.4201(9) A β = 102.614(1) A, in the P21/c space group. The packing of this complex is quite similar to the PF6 −, BF4 −, and ClO4 − analogs but contains three crystallographically unique [Cu(MeCN)2(PPh3)2](CF3SO3) complexes per asymmetric unit (instead of one). Upon dissolution and recrystallization of this salt in either toluene or tetrahydrofuran, anion (and solvent) coordination results in the formation of two new neutral species Cu(PPh3)2(CF3SO3)(MeCN) 2 and Cu(PPh3)2(CF3SO3)(THF) 3, respectively. Both 2 and 3 crystallize in the orthorhombic Pca21 space group with a = 22.533(1), b = 9.0688(5), c = 18.4689(9) A, and a = 22.434(1), b = 8.9789(5), c = 18.418(1) A, respectively. With the perchlorate anion, [Cu2(ClO4)(MeCN)(PPh3)4(THF)](ClO4) 4, is isolated, which crystallizes in the monoclinic space group C2/c with a = 27.308(1), b = 28.064(1), c = 21.448(1) A, and β = 120.342(1)°. Surprisingly, it is comprised of an analogous solvent coordinated neutral molecule, Cu(PPh3)2(THF)0.8(MeCN)0.2(ClO4) together with an anion-bridged dimeric species, [Cu2(PPh3)4(MeCN)1.6(THF)0.4(ClO4)]+, charge balanced by one additional non-coordinated ClO4 − anion. The coordinated solvent molecules are disordered in both moieties. Compounds 1–3 were further characterized using thermal gravimetric analysis.
Control of thyrotropin secretion in man.

ADVANCES in methodology have largely been responsible for the newer data on thyrotropin (TSH) secretion by the human pituitary gland. These advances are the radioimmunoassay of human TSH and the di...
Parasitic vibration attenuation in ultrasonic welding of battery tabs

Lithium-ion battery cells of pouch type for battery electric vehicles are often joined by ultrasonic welding. High-frequency vibration generated by the piezoelectric transducer of the welder creates solid-state bonds between the workpieces via interfacial frictional heat. This vibration, however, can cause parasitic vibration of the entire system that is harmful to the structure (such as destroying existing welds). In this study, a modulation of input waveforms of the ultrasonic welder is proposed to reduce such parasitic vibration. A series of vibration models are analyzed: (a) a discrete model of single-degree-of-freedom (SDOF) mass–spring–damper system to understand rigid body dynamics, (b) a continuous model of multi-degree-of-freedom (MDOF) cantilever beam to study an elastic body system, and (c) a battery welding system to study a complex real-world application. Analyses indicate that the waveform modulation (including 180°-phase shift, pause, amplitude stepping, and frequency modulation) can reduce parasitic vibration while improving or maintaining the quality of the weld that is being ultrasonically made.
The antibacterial shield of the human urinary tract

Antibacterial peptides and proteins maintain the sterility of the human urinary tract. A broad-spectrum antimicrobial protein, ribonuclease 7 (RNase 7), previously discovered to play a role in controlling the growth of bacteria on human skin, has now been shown to have an important antibacterial function in the human urinary tract.
Auditory Training for Children With Auditory Processing Disorder and Language Impairment: A Response to Bellis, Chermak, Weihing, and Musiek

Purpose We respond to Bellis, Chermak, Weihing, and Musiek’s (2012) criticisms of the evidence-based systematic review of Fey et al. (2011) on the effects of auditory training on auditory, spoken, ...
Phosphate products and the extent of the geographic market

Abstract The manufacture and distribution of phosphate rock and its associated products are large consumers of energy. As a consequence, a change in the price of energy can have a quite substantial effect on the cost of production. This will affect the price that the product can be sold for. Whether this will affect the sales of the product is dependent on what is the relevant market. Consequently, to understand this issue, the extent of the geographic market must be defined. To this end, a definition is detailed relying on the concept of instantaneous causality. Monthly data for four phosphate products for the period 1980 through 1985 are used to implement the approach empirically. For three of the four products considered, the empirical results suggest that there is a world market.
Digital Teachers Reshaping Literacy Experiences.

When the National Reading Panel ([NRP] 2000) released its report challenging school districts to re-inspect then realign literacy programs according to “best practices,” a digital literacy explosio...
Fabrication and characterization of SiO2 microcantilever for high sensitive moisture sensor

μThis paper reports a novel design of SiO 2 microcantilever for high sensitivity sensor platform. In order to fabricate this device, a new fabrication process using isotropic combined with anisotropic dry etching to release the SiO 2 microcantilever beam by ICP (Inductively Coupled Plasma) was developed and investigated. This new process not only obtains a high etch rate at 9.1 mm per minute, but also provides a good profile controllability, and a flexibility of device design. To compare the SiO 2 and Si cantilever beam, the results of simulation and theoretical analysis are given. The results predict the SiO 2 cantilever can achieve a higher sensitivity than the Si cantilever. The SiO 2 cantilever beams with 1 mm thickness, 100 mm width, and 250 mm length were fabricated and tested by exposing it to aminoethanethiol solution of low concentration. The experimental data support the prediction derived from the simulation results. The moisture sensor based on the surface modified cantilever beam showed a good response to one percentage relative humidity.
Effect of rainfall transients on thermal and moisture exposure of underground electric cables

Abstract Cable ampacity analysis is generally performed assuming constant worst-state environmental conditions, which often correspond to a dry soil condition or to a condition with uniform ambient soil moisture content. The characteristic time scale of thermal variation in the soil is large, on the order of several weeks, and is similar to the time scale between rainfall events in many geographic locations. Intermittent rainfall events introduce significant transient fluctuations that influence the thermal conditions and moisture content around a buried cable both by increasing thermal conductivity of the soil and by increasing the moisture exposure of the cable insulation. This paper reports on a computational study of the effect of rainfall events on the thermal and moisture transients surrounding a buried cable. The computations were performed with a finite-difference method using an overset grid approach, with an inner polar grid surrounding the cable and an outer Cartesian grid. The thermal and moisture transients observed in computations with periodic rainfall events were compared to control computations with a steady uniform rainfall. Under periodic rainfall conditions, the temperature and moisture fields are observed to approach a limit-cycle condition in which the cable surface temperature and moisture content oscillate in time, but with mean values that are significantly different than the steady-state values.
UTI and Watchful Waiting: The Courage to Do Nothing

* Abbreviations: AAP — : American Academy of Pediatrics RBUS — : renal and bladder ultrasound UTI — : urinary tract infection VCUG — : voiding cystourethrogram VUR — : vesicoureteral reflux In this issue of Pediatrics , Nelson and colleagues present a retrospective cross-sectional study of children <60 months of age who underwent renal and bladder ultrasound (RBUS) and voiding cystourethrogram (VCUG).1 Like other studies of this topic,2–6 this is a retrospective analysis of data captured through routine care, but it is probably the largest and most well-conducted study of its kind. Their findings are consistent with most earlier work, and their conclusions valid: RBUS is a lousy screen for vesicoureteral reflux (VUR). Because the new American Academy of Pediatrics (AAP) guidelines7 recommend routine RBUS after the first febrile urinary tract infection (UTI), the authors make the point that a negative RBUS should not be interpreted as ruling out VUR or other conditions detectible on VCUG. This raises an important … Address correspondence to Stephen M. Downs, MD, MS, 410 West 10th St, HS1000, Indianapolis, IN 46202. E-mail: stmdowns{at}iu.edu
Fifth graders' additive and multiplicative reasoning: Establishing connections across conceptual fields using a graph

Abstract This paper looks at 21 fifth grade students as they discuss a linear graph in the Cartesian plane. The problem presented to students depicted a graph showing distance as a function of elapsed time for a person walking at a constant rate of 5 miles/h. The question asked students to consider how many more hours, after having already walked 4 h, would be required to reach 35 miles. To answer this question, the students needed to extend the graph that was presented, either mentally or on paper, as the axes did not go up to 7 h or 35 miles. They also needed to be able to consider not only the total number of hours to reach 35 miles, but also the interval of time after 4 h. The purpose of this paper is to consider the student responses from the viewpoint of multiplicative and additive reasoning, and specifically within Vergnaud's framework of multiplicative and additive conceptual fields and scalar and functional approaches to linear relationships ( Vergnaud, 1994 ). The analysis shows that: some student answers cannot be classified as either scalar or functional; some students combined several kinds of approaches in their explanations; and that the representation of the problem using a graph may have facilitated responses that are different from those typically found when the representation presented is a function table.
Behaviour of calcium carbonate in sea water

Abstract Anomalies in the behaviour of calcium carbonate in natural solutions diminish when considered in context. Best values found by traditional oceanographie methods for the apparent solubility product constant K ' CaCO 3 in sea water at atmospheric pressure are consistent mineralogically—at 36 parts per thousand salinity and T-25°C, K ' aragonlte is estimated as 1.12 × 10 −6 and K ' calcite as 0.61 × 10 −6 . At 30°C the corresponding values are 0.98 × 10 −6 for aragonite and 0.53 × 10 −6 for calcite. Because the K ' computations do not compensate for ionic activity, however, they cannot give thermodynamically satisfactory results. It is of interest, therefore, that approximate methods and information now available permit the estimation from the same basic data of an activity product constant K CaCO 3 close to that found in solutions to which Debye-Huckel theory applies. Such methods indicate approximate K aragonite 7.8 × 10 −9 for surface sea water at 29°C; K calcite would be proportionately lower. Field data and experimental results indicate that the mineralogy of precipitated CaCO 3 depends primarily on degree of supersaturation, thus also on kinetic or biologic factors that facilitate or inhibit a high degree of supersaturation. The shallow, generally hypersaline bank waters west of Andros Island yield aragonitic sediments with O 18 O 16 ratios that imply precipitation mainly during the warmer months, when the combination of a high rate of evaporation, increasing salinity (and ionic strength), maximal temperatures and photosynthetic removal of CO 2 result in high apparent supersaturation. The usual precipitate from solutions of low ionic strength is calcite, except where the aragonite level of supersaturation is reached as a result of diffusion phenomena ( e.g. dripstones), gradual and marked evaporation, or biologic intervention. Published data also suggest the possibility of distinct chemical milieus for crystallographic variations in skeletal calcium carbonate. It appears that in nature aragonite precipitates from solutions that are supersaturated with respect to both calcite and aragonite and calcite between saturation levels for the two species. Such a relation is consistent with Ostwald's rule of successive reactions. Aragonitc of marine origin persists in contact with supersaturated interstitial solutions at ordinary temperature and pressure. Conversion to calcite follows transfer to solutions undersaturated with respect to aragonite or upon exposure to the moist atmosphere.
Acoustic Emission Analysis of Damage during Compressive Deformation of Amorphous Zr-Based Foams with Aligned, Elongated Pores

Acoustic emission methods are used to investigate the evolution of internal microfractural damage during uniaxial compression of amorphous Zr-based foams with aligned, elongated pores. The foams are fabricated by means of densifying a blend of crystalline W powders and amorphous Zr-based powders with two oxygen contents (0.078 and 0.144 wt pct) by warm equal channel angular extrusion, followed by dissolution of the elongated W phase from the fully densified amorphous matrix. For the high-oxygen foams, prior powder boundaries in the amorphous struts promote damage that accumulates during compression, resulting in energy-absorbing properties comparable with the low-oxygen foams without stress-concentrating powder boundaries. The influence of pore orientation on the evolution of microfracture damage and the ability of the foams to accumulate damage without catastrophic failure is also investigated: pores oriented from 24 to 68 deg to the loading direction promote wall bending, resulting in foams with more diffuse damage and better energy-absorbing properties.
The effect of water vapor on the corrosion of carbon steel at 65{degree}C

AISI 1020 carbon steel was exposed to air at various relative humidities at 65{degrees}C. A ``critical relative humidity`` (CRH) of 75--85% was determined. The CRH is the transitional relative humidity where oxidation/corrosion changes from dry oxidation to aqueous film electrochemical corrosion. Short term testing suggests that aqueous film electrochemical corrosion results in the formation of an inner oxide of Fe{sub 3}O{sub 4}, and an outer oxide of a powdery Fe{sub 2}O{sub 3} and/or Fe{sub 2}O{sub 3}{center_dot}xH{sub 2}O.
Time relationships of sporopollenin synthesis associated with tapetum and microspores in Lilium.

The development of the sporopollenin orbicules (Ubisch bodies) on the tapetal cells of Lilium begins while the spores are still enclosed in the meiotic tetrads. Spherosome-like structures, the pro-orbicular bodies, accumulate in the vicinity of the plasmalemma early in the tetrad period, and are extruded into the space within the degenerating inner walls of the tapetal cells. There they acquire a coating of sporopollenin, the accretion continuing until after the release of the spores from the tetrads. Some orbicules remain attached to the plasmalemma by stalks. Synthesis of a material of the general class of sporopollenin begins in the primexine of the young spore in the mid-tetrad period, again outside of the cell membrane, but within the callose tetrad wall.
Locating “youth voice:” Considering the contexts of speaking in foster care

Abstract Within social services, an increasingly significant movement supports giving “voice” to children and youth, enabling them to express their views and to have those views taken into account in matters that affect them. In this article, the author draws from narratives of young people who grew up in foster care, examining stories of their efforts to impact the course of their own lives. The article explores the ways that very specific contexts and relationships of power shaped the utterances of young people in the foster care system and distorted, muted, or amplified their abilities to express their need and interests. This is a beginning attempt to identify ways that contexts of speaking in foster care can be understood and altered in order to strengthen the capacity of young people to voice their concerns and aspirations.
Lest Memory Cease: Finding Meaning in the American Jewish Past

Noting the remarkable success of American Jews in the business and professional world, Feingold questions the price paid for such success in terms of the loss of the distinct Jewish identity and direction.
THE PROBABLE ORIGIN OF ORYZOPSIS CONTRACTA

A B S T R A C T Oryzopsis contracta is found only in the Big Hollow area of southern Wyoming where it exists sympatrically with the widely distributed species 0. hymenoides and 0. micrantha. The three species are probably reproductively isolated from each other. Oryzopsis contracta is very similar to 0. hymenoides; however, they can be separated on several characters. It also resembles 0. micrantha in several characters. This suggests that 0. contracta may have evolved through hybridization between the other two species. A quantitative analysis shows that 0. contracta occupies an intermediate and central position between the other two species with regard to most characters analyzed. Scatter diagrams reveal a correlated deviation of 0. contracta individuals from 0. hymenoides toward 0. micrantha with respect to several characters. Meiosis in occasional sterile 0. hymenoides X 0. contracta hybrids shows multivalent associations, suggesting that an appreciable part of the presumed micrantha contribution to the contracta genome was in the form of relatively large chromosome segments. The data suggest that 0. contracta evolved as a result of chromosomal translocations in a chance hybrid between 0. hymenoides anid 0. micrantha followed by backerossing to 0. hymenoides and subsequent self-fertilization of the hybrid.
Mode I microfracturing and fluid flow in damage zones: The key to distinguishing faults from slides

Abstract We have examined the distribution of microfractures in arenites and the evolution of vein forming fluids in the matrix of carbonate breccias within the damage zones of large detached blocks in order to characterize their modes of emplacement. Previous studies of microfractures in the damage zone associated with tectonic faulting have shown a clear pattern of increasing density as the fault is approached. Previous studies of carbonate breccia within damage zones of tectonic faults typically document evidence of multiple fluid events representing repeated rupture-healing processes. However, in this study, we find no change in the microfracture density with distance from the 45 km-displaced gravity-driven slide block at Heart Mountain, Wyoming. In a previous study of the same massive slide block there was no evidence of multiple fluid infiltration events related to emplacement. We interpret these observations as indicating the absence of rupture cycling that would be expected in the development of a process zone, instead being consistent with catastrophic emplacement of gravity-driven slide blocks. We use this distinct pattern of microfracture density and fluid infiltration to demonstrate that several large (>1 km2) detached blocks in the Basin and Range, previously thought to be allochthons related to hyperextension detachment faults, are actually slide blocks whose detachment surfaces represent no crustal extension.
Accuracy of frozen section examination of testicular tumors

Benign testicular masses are recognized with increasing frequency and testis-sparing surgery, based on benign frozen section diagnosis, is practiced more often. However, there is a paucity of information in the medical literature regarding the accuracy of frozen section diagnoses of testicular tumors, and misdiagnoses could have dire consequences. We reviewed thirty frozen section examinations that were performed between 1962 and 1991, a period in which five hundred inguinal orchiectomies were performed. The entire testicle was available for histologic evaluation in 26 cases. Frozen sections correctly identified all of twenty-four malignant and two benign testicular masses. This study demonstrates that frozen section examinations can accurately diagnose testicular cancer.
On varieties of commuting triples

Abstract The problem of approximating triples of commuting n × n matrices by triples of generic matrices is equivalent to that whether the variety C ( 3 , n ) of triples of commuting matrices is irreducible. It is known that the variety is irreducible for n ⩽ 7 and reducible for n ⩾ 30 . Using simultaneous commutative perturbations of pairs of matrices in the centralizer of the third matrix we prove that C ( 3 , 8 ) is irreducible.
Duration of Antibiotic Therapy for Lyme Disease

Over the years, physicians have prescribed longer and longer courses of antibiotic therapy for erythema migrans (often 21 to 30 days), primarily to treat persistent subjective symptoms. Investigato...
Measurements of electron attachment lineshapes and cross sections at ultra-low electron energies for CF2Cl2, c-C4F6, c-C4F8 and c-C7F14

Electron-attachment cross sections are reported in the electron energy range 0-160 meV, and at energy resolutions of 7.0 and 7.5 meV (FWHM), for the molecules CF2Cl2 (dichlorodifluoromethane), c-C4F6 (perfluorocyclobutene), c-C4F8 (perfluorocyclobutane), and c-C7F14 (perfluoromethylcyclohexane). Use is made of the Kr photoionization method. Measured attachment lineshapes are deconvoluted from the spectral slit function, and are converted to cross sections by normalization through thermal attachment-rate constants. Comparisons are made with attachment cross sections derived from several independent sets of swarm-measured rate constants, and with collisional ionization (high-Rydberg attachment) data.
Predictors of Having a Potential Live Donor: A Prospective Cohort Study of Kidney Transplant Candidates

The barriers to live donor transplantation are poorly understood. We performed a prospective cohort study of individuals undergoing renal transplant evaluation. Participants completed a questionnaire that assessed clinical characteristics as well as knowledge and beliefs about transplantation. A participant satisfied the primary outcome if anyone contacted the transplant center to be considered as a live donor for that participant. The final cohort comprised 203 transplant candidates, among whom 80 (39.4%) had a potential donor contact the center and 19 (9.4%) underwent live donor transplantation. In multivariable logistic regression, younger candidates (OR 1.65 per 10 fewer years, p or=US$ 15 000 (OR 4.22, p = 0.03) were more likely to attract a potential live donor. Greater self-efficacy, a measure of the participant's belief in his or her ability to attract a donor, was a predictor of having a potential live donor contact the center (OR 2.73 per point, p < 0.01), while knowledge was not (p = 0.56). The lack of association between knowledge and having a potential donor suggests that more intensive education of transplant candidates will not increase live donor transplantation. On the other hand, self-efficacy may be an important target in designing interventions to help candidates find live donors.
Enterococcus pneumonia and septicemia in a two-month-old infant

Summary Enterococcus pneumonia associatedwith septicemia, pleuritic involvement, and cavitation was observed in a 2-month-old infant. The blood stream infection was transient. However, the pulmonary pathology persisted for eight months before complete resolution could be detected. Therapy with Terramycin and Ilotycin was very effective in controlling the disease.
Quantum liquid-crystal order in resonant atomic gases

Abstract I review recent studies that predict a realization of quantum liquid-crystalline orders in resonant atomic gases. As examples of such putative systems I will discuss an s -wave resonant imbalanced Fermi gas and a p -wave resonant Bose gas. In the former, the liquid-crystalline smectic, nematic and rich variety of other descendant states emerge from strongly quantum- and thermally-fluctuating Fulde–Ferrell and Larkin–Ovchinnikov states, driven by a competition between resonant pairing and Fermi-surface mismatch. In the latter, at intermediate detuning the p -wave resonant interaction generically drives Bose-condensation at a finite momentum, set by a competition between atomic kinetic energy and atom–molecule hybridization. Because of the underlying rotationally-invariant environment of the atomic gas trapped isotropically, the putative striped superfluid is a realization of a quantum superfluid smectic, that can melt into a variety of interesting phases, such as a quantum nematic. I will discuss the corresponding rich phase diagrams and transitions, as well the low-energy properties of the phases and fractional topological defects generic to striped superfluids and their fluctuation-driven descendants.
Management of amelogenesis imperfecta by periodontal and prosthetic therapy

Abstract One solution has been provided to a very difficult restorative and periodontal problem created by amelogenesis imperfecta. By preparing the teeth of one dental arch at a time and by utilizing splints constructed at the patient's centric relation, the time involved in treatment was reduced and discomfort to the patient was minimized. Occlusion in his procedure must be meticulously checked. The patient was carefully observed for a period of five months to allow for healing of the soft tissue and for return of normal stability of the teeth. Only when no further opening of proximal contacts occurred was the restoration permanently cemented. Patients with amelogenesis imperfecta need not be faced with extraction of their teeth at an early age. A definite advantage is gained by combining the disciplines of periodontics and prosthodontics.