cssi/SciSciGPT-SciSciNet huggingface dataset:
Physics of Hard Spheres Experiment: a general-purpose light-scattering instrument

A general-purpose, multifunction light-scattering instrument has been developed at the NASA Lewis Research Center for Space Shuttle and Space Station colloid crystallization and other microgravity experiments. For a single sample, the instrument can measure two-dimensional Bragg scattering from 0.5° to 60°, dynamic and static light scattering from 10° to 170°, the shear modulus of samples before and after crystallization, and digital color images of the sample. A carousel positions any one of eight 3-ml samples into the test position for separate experiments. Program challenges and flight results from the STS-83 Space Shuttle mission are discussed.
A hybrid electrochemical/chemical synthesis of semiconductor nanocrystals on graphite: a new role for electrodeposition in materials synthesis

Metal (copper and cadmium) nanocrystallites -electrochemically deposited on the graphite basal plane- have been converted on a particle-by-particle basis to nanocrystals of a semiconducting metal salt (Cul and CdS). Deposition of the metal nanocrystals from a dilute ([M n+ ] 1.0 mM) plating solution is accomplished using a potentiostatic pulse with an overpotential of -500 mV and a duration in the range 50-200 ms. Non-contact atomic force microscopy images of the surface show that defect sites, such as step edges, and apparently atomically smooth terraces on the graphite basal plane both are covered with metal particles at an areal density of 10 9 -10 10 cm -2 . Each of these metal nanocrystallites is then converted into a semiconducting salt particle in two subsequent steps: first, metal nanocrystals are chemically or electrochemically oxidized at the appropriate pH to yield either metal oxide or hydroxide nanocrystals; secondly, the oxygen or hydroxide is displaced with an anion to yield the semiconducting salt of interest. This final displacement step is always chemical in nature. The CuI and CdS nanocrystals prepared using this E/C approach possess an excellent lattice match to graphite and epitaxially oriented nanocrystals are obtained with both materials. The particle size distribution for E/C-synthesized particles is determined by that of the parent metal particle distribution. Both CdS and CuI nanocrystals prepared by the E/C method are strongly luminescent at the band edge.
Cracking and stress redistribution in ceramic layered composites

Abstract Problems are analyzed that have bearing on cracking and survivability in the presence of cracking of layered composite materials composed of brittle layers joined by either a weak interface or a thin layer of a well-bonded ductile metal. The problems concern a crack in one brittle layer impinging on the interface with the neighbouring brittle layer and either branching, if the interface is weak, or inducing plastic yielding, if a ductile bonding agent is present. For the case of a weak interface, the effect of debonding along the interface is analyzed and results for the stress redistribution in the uncracked layer directly ahead of the crack tip are presented. Debonding lowers the high stress concentration just across the interface, but causes a small increase in the tensile stresses further ahead of the tip in the uncracked layer. A similar stress redistribution occurs when the layers are joined by a very thin ductile layer that undergoes yielding above and below the crack tip, allowing the cracked layer to redistribute its load to the neighbouring uncracked layer. The role of debonding and yielding of the interface in three-dimensional tunnel cracking through an individual layer is also discussed and analyzed. Residual stress in the layers is included in the analysis.
Hispanic coupon usage: The impact of strong and weak ethnic identification

The fragmentation of mass markets and its economic importance has dramatically increased the need to better target and understand ethnic markets. This article argues that the strength of ethnic identification, which measures the strength to which a person feels tied to the culture of origin, is a key variable in understanding the impact of ethnicity on responses to marketing mixes. The major hypothesis driving this study therefore states that, when the strength of ethnic identification is high, the ethnic consumer will respond to marketing the way their parents' culture does. This study analyzes Hispanic consumers and demonstrates that Weak Hispanic identifiers are quite different from Strong Hispanic identifiers in their coupon usage, and that Weak Hispanic identifiers are more like the dominant culture. Specifically, this study shows that cultural reasons may overshadow economic reasons in explaining coupon usage and brand loyalty.
A continuous analysis process between desktop and collaborative visual analytics environments

Since its inception, the field of visual analytics has undergone tremendous growth in understanding how to create interactive visual tools to solve analytical problems. However, with few exceptions, most of these tools have been designed for single users in desktop environments. While often effective on their own, most single-user systems do not reflect the collaborative nature of solving real-world analytical tasks. Many intelligence analysts, for example, have been observed to switch repeatedly between working alone and collaborating with members of a small team. In this paper, we propose that a complete visual analytical system designed for solving real-world tasks ought to have two integrated components: a single-user desktop system and a mirroring system suitable for a collaborative environment.
William Hogarth's The March to Finchley and the fate of comic history painting

Completed in 1750, William Hogarth's The March to Finchley set out to demonstrate that a Protestant trading nation could produce a form of history painting free from the absolutist tendencies of European academicism. This essay argues that Hogarth's accomplishment was more thoroughgoing and intellectually rigorous than previously recognized, and that combined with the Analysis of Beauty (1753), it established a new agenda for ambitious art production. Through its manipulation of a domestic visual vocabulary, The March to Finchley transformed status consciousness into an inclusive artistic category and oppositional political rhetoric into a positive national identity. Comic history, as this new genre was called, offered a stable, yet flexible foundation for the emergence of a distinctively British school of art. That this school never came to fruition was largely because of a shift in Britain's political climate, and in particular, a rise in popular imperial enthusiasm brought about by the Seven Years' War. Douglas Fordham graduated from Yale University where he received the Frances Blanshard prize for an outstanding doctoral dissertation in the History of Art. He is currently a Mellon Postdoctoral Fellow in the Department of Art History and Archaeology at Columbia University.
POSTOPERATIVE REHABILITATION FOLLOWING TOTAL SHOULDER ARTHROPLASTY

It is essential that patients receive proper rehabilitation following a total shoulder arthroplasty. This should ideally include a preoperative visit that includes the specified therapist, patient, and primary caregiver. The rehabilitative process is an individual program, and the protocol described is suggested as a guide for the therapist. The order of the exercises listed is more important than the time at which they are started, with an emphasis on maximizing motion prior to aggressive strengthening.
On the confidence level fusion of IR and forward-looking GPR

We consider in this paper the improvement of side-attack mine detection by performing confidence level fusion with data collected from vehicle-mounted forward-looking IR and GPR (FL-GPR) sensors. The mine detection system is vehicle based, and has both IR and FL-GPR sensors mounted on the top of the vehicle. The IR images and FL-GPR data are captured as the vehicle moves forward. The detections from IR images are obtained from the Scale-Invariant Feature Transform (SIFT) and Morphological Shared-Weight Neural Networks (MSNN) depending on target characteristics, and those from FL-GPR are derived from the FL-GPR SAR images through object-tracking. Since the IR and FL-GPR alarms do not occur at the same location, the fusion process begins with each IR alarm and looks at the nearby FL-GPR alarms with confidences weighted by values that are inversely proportional to their distances to the IR alarm. The FL-GPR alarm with the highest weighted confidence is selected and combined with the IR confidence through geometric mean. An experimental dataset collected from a government test site is used for performance evaluation. At the highest Pd and comparing with IR only, fusing IR and FL-GPR yields a reduction of FAR by 26%. When the Hough transform is applied to reject the IR alarms that have irregular shapes, the fusion results provides a reduction of FAR by 35% at the highest Pd.
Prenatal Diagnosis of Exenceplhaly

Exencephaly is a rare congenital anomaly, thought to be a precursor of anencephaly. Like anencephaly, this abnormality is characterized by absence of the cranial vault above the orbits. However, unlike anencephaly, discrete, sometimes disorganized, brain tissue can be identified above the cranial defect. In this article, the authors report a case of exencephaly diagnosed prenatally during transvaginal ultrasound examination, with anatomic and pathologic correlation.
The foaming properties of proteins isolated from barley

Albumin and hordein protein fractions have been isolated from barley by extraction with salt and aqueous ethanol respectively. Both produce stable foams as assessed by a shaking procedure, and in each case foaming was enhanced by denaturation of the proteins. Foam power was increased rather more for albumin than for hordein, especially by heat, and this was accompanied by an increase in hydrophobic character as assessed by the fluorochrome 1-anilino-8-napthalenesulphonic acid. Iso-α-acids and reduced iso-α-acids increased the foam stability of both albumin and hordein, with there being a proportionately greater increase for the undenatured proteins. Albumin is resistant to hydrolysis by the cysteine proteinases ficin and papain but is hydrolysed by the serine proteinase trypsin. In the latter instance, hydrolysis is accompanied by a loss of foam stability. By contrast, hordein is resistant to digestion by trypsin but is susceptible to the action of ficin and papain. In these instances, limited proteolysis leads to a substantial enhancement of foam stability from hordein, though prolonged proteolysis is detrimental. Proteinase A from yeast hydrolyses both protein classes and lowers their ability to give stable foams. It is concluded that polypeptides derived from both albumin and hordein could make a contribution to the foam potential of beer. © 2002 Society of Chemical Industry
Linear Stability of Steady States for Thin Film and Cahn-Hilliard Type Equations

We study the linear stability of smooth steady states of the evolution equation $$h_t = - (f(h)_{xxx} )_x - (g(h)h_x )_x - ah$$ under both periodic and Neumann boundary conditions. If a≠ 0 we assume f≡ 1. In particular we consider positive periodic steady states of thin film equations, where a=0 and f, g might have degeneracies such as f(0)=0 as well as singularities like g(0)=+∞.
Operating Room: Many Factors in O.R. Environment Discussed in Postgraduate Course.

(1971). Operating Room: Many Factors in O.R. Environment Discussed in Postgraduate Course. Hospital Topics: Vol. 49, No. 2, pp. 79-97.
A vasoactive intestinal polypeptide system in retinal cell cultures: immunocytochemistry and physiology

The purpose of this study was to search for vasoactive intestinal polypeptide (VIP)-like immunoreactivity and VIP-mediated effects in cultures containing cells from the mammalian retina. VIP-like immunoreactivity was detected by indirect immunocytochemistry within 6 days after plating dissociated retinal cells from embryonic day-19 rats. In electrophysiological experiments, VIP was found to facilitate evoked transmission at cholinergic synapses formed by retinal neurons in culture.
Phenol β-glucosyltransferases in six species of insects: properties and tissue localization

Abstract 1. 1. Phenol β-glucosyltransferase (PGT) activity in tissues of six species of insects was determined by HPLC with UV/VIS detection of the β-glucoside products. 2. 2. PGT activity was associated mainly with the 15,000 g pellet fraction of tissue homogenates, the fat body generally had the highest specific activity followed by the midgut. 3. 3. PGT activity was greatest with UDPG as a glucose donor, followed by dTDPG and GDPG. 4. 4. A broad range of phenolic compounds, including mono- and diphenols, coumarins and a flavonoid, were glucosylated by insect PGTs. Two generalist herbivores, the grasshopper Melanoplus sanguinipes and the black cutworm Agrotis ipsilon, had the highest PGT activities, whereas other species, with more limited food selection, had lower rates of glucosylation.
Performance of a Nickel Boride Fuel Cell Anode using Hydrogen and Ethylene

Two factors have to be borne in mind in considering the possible widespread application of fuel cells, namely, the world supply and the cost of the catalysts. Slaughter and Gilvarry1 have pointed out that only a few hundredths of 1 per cent of the world demand for power could be produced by hydrogen–oxygen fuel cells using the entire world production of platinum. Consequently, attempts have been made to find cheaper and more readily available materials, even though platinum is a superior catalyst. Sintered powdered nickel has been used, for example, by Bacon2, but a performance comparable to that of platinum at ambient temperatures can only be obtained at 200° C. Another variant, which eliminates the need to go to a higher temperature, is Raney nickel3. More recently it has been shown that a performance only slightly less than that of the noble metals can be obtained with ‘Teflon’ bonded nickel boride supported on a nickel screen4–7. At the same power-level and the same operating efficiency, the cost of these electrodes is only one-twentieth of those containing platinum. It is also interesting to note that cobalt molybdate8 is almost as good as platinum black in catalysing the electrochemical oxidation of hydrocarbons such as propane and propylene.
Estrogen accelerates the recovery of the lordosis response after its exhaustion induced by cervical probing

Repetitive flank-perineum palpation combined with probing the vaginal cervix in ovariectomized hormonally untreated rats elicited a mean of 4.2 ± 0.2 (SEM) successive lordosis responses before the response was exhausted. Two days after a single injection of estradiol benzoate (100 μg/kg body wt) in ovariectomized rats, a significantly greater number (7.8 ± 0.2) of lordosis responses could be elicited before the response was exhausted (P < 0.01). After this exhaustion, recovery of lordosis responsiveness to this stimulation occurred significantly earlier in the estrogen-treated rats (6 hr) than in the oil-treated rats (60 hr) (P < 0.01). Several possible mechanisms mediating these effects are proposed.
From pole to pole: Soundscapes of the Atlantic Ocean

Between July 2009 and December 2010, two identical calibrated hydrophone packages were deployed and continuously operated (2,000 Hz sampling rate) in the Fram Strait (79°N, 5.5°E) and the Bransfield Strait (62°S, 55.5°W). Analysis of these recordings were combined with a data set collected during the same time period by the Comprehensive Nuclear-Test-Ban Treaty Organization International Monitoring System (CTBTO IMS) hydroacoustic station HA10 (250 Hz sampling rate) at Ascension Island (8°S, 14.4°W). The combination of these datasets allowed a comparison of low-frequency noise levels in polar and tropic areas of the Atlantic Ocean. The recordings were analyzed for major natural (e.g., marine mammals, ice) and anthropogenic (e.g., shipping, seismic) contributors to the ambient sound field and their seasonal variability. Preliminary results indicate (1) a higher seasonal variability of ambient noise levels in polar regions compared to the tropics, (2) the seasonal variability of ambient noise levels in the ...
Wind tunnel simulation of TTU flow and building roof pressure

Abstract A study of approach wind flow and wind-induced pressure on a 1 : 50 geometrical scale model of the Texas Tech University test building was performed in a boundary layer wind tunnel at Colorado State University. The model and full-scale flow parameters and pressure coefficients are presented for low-turbulence nominal flow. The comparison of the model and prototype building point pressure exhibits a better agreement for most of the pressure taps, including the critical corner region, than other reported wind tunnel results. The study shows a significant reduction in the extreme peak pressure at critical locations due to low-pass filtering with a relatively high-frequency cut-off. This points out to the importance of proper selection of the frequency range for low-pass filtering and sampling of the pressure signals.
Causes of Blind Wood in Roses

It is well known that many hybrid roses and also pure species produce great numbers of non-flowering branches which are commonly called " blind shoots." With some greenhouse varieties 50 per cent, or more of the average growth in one year may consist of blind shoots. These blind shoots represent a tremendous reduction in flowering wood, and because of this reduction the underlying causes of blindness are of great importance to the commercial rose grower. The habit of blind wood formation is especially noticeable in the forced hybrid tea rose, which is a monthly blooming plant cultivated for heavy and regular flower production. The phenomenon of blindness is noticeable, however, to a lesser extent in hybrid perpetual roses and some pure species. The difference in flowering habit between the rose classes may account for the differences in blind wood production. These differences in blooming habit are exemplified by the hybrid tea rose which is never in a purely vegetative condition, and by the hybrid perpetuals and some pure species which for two-thirds of their growing season are in a vegetative state. The production of blind wood in the rose appears to be a varietal characteristic, because with certain varieties of hybrid tea roses, regular blooming accompanied by a minimum production of blind wood occurs. Other hybrid tea varieties produce such a high percentage of blind wood that they are worthless for commercial forcing. If blind wood could be controlled some of these varieties might become valuable, and flower production could presumably be increased in many of the varieties now in commercial use. The occurrence of blind wood on rose plants was observed many years ago. In 1859 an anonymous writer (1) stated: "Pruning no more seems to prevent free blooming than non-pruning seems to promote it. ... When the variety Isabella Grey was placed against a warm, sunny wall, it produced thirty strong shoots each of which terminated with blind ends. ' ' The florists' trade journals have for many years published discussions and comments on the causes of blind wood in forced rose plants. These discussions are not based on experimental data but are offered merely as a result of observations. These trade journal discussions have helped to establish the phenomenon of blindness in roses as a problem worthy of the attention of investigators in the fields of plant research.
Further Studies on the Endogenous Inhibitor of Monoamine Oxidase in Schizophrenic Plasma

Platelet-free plasma from schizophrenic patients satisfying research diagnostic criteria for chronic schizophrenia was obtained and mixed with platelet-rich plasma from normal controls. Decreases in control platelet monoamine oxidase activity were observed, with some control platelets apparently much more sensitive than others to the inhibitory activity of the chronic schizophrenic plasma. Experimental conditions and selection from sensitive control individuals seem crucial in demonstrating the presence of endogenous inhibitors in schizophrenics' plasma.
The helping community: Issues in the evaluation of a preventive intervention to promote informal helping

This report addresses conceptual and practical problems in evaluating the effectiveness of an intervention which used a pyramid training model for improving helping skills for informal helpers in two rural communities. Against a background for a study of help-giving and help-seeking patterns, the transmission of helping skills from professional to community trainers to local helpers was studied. Impacts of the intervention on other aspects of the community are reported.
Cleaner Lakes Are Dirtier Lakes

Phosphorus pollution can often explain the difference between a lake clogged with algae and a clear lake where people flock to fish and swim. Although nutrient pollution remains the most common source of water-body impairment throughout much of the developed world ( 1 ), phosphorus management has reduced algal blooms in many temperate lakes worldwide ( 2 ). Yet on page 247 of this issue, Finlay et al. ( 3 ) report a downside to this success. In a series of lakes in which phosphorus inputs have declined, they show substantial increases in nitrate pollution.
Transferability of multicultural education from training to practice

Abstract This study discovered strong transferability of multicultural perservice training content to utilization in teaching. Generally, and across demographic subgroups, multicultural experiences reflected the highest degree of transferability, suggesting that this may be the most effective and meaningful teaching-learning modality with multicultural material . Understandings and skills transferred next highest; and these transfers were more pronounced among older, experienced white teachers with graduate degrees . Attitudes transferred least, and this transfer was strong among relatively young and inexperienced minority teachers who had undergraduate degrees .
Are galactic GRB models still an option

The traditional paradigm of a Galactic origin of gamma-ray bursts (GRBs) suffered a major reduction in popularity when BATSE revealed an isotropic but radially inhomogeneous distribution of GRBs. The lack of pronounced galactic anisotropies places severe constraints on models including significant source contributions from the usual disk, bulge, or halo components of the Milky Way. Although models can be designed to preserve the local disk origin, a perhaps more promising approach invokes a very extended Galactic halo. Populating such halos with neutron stars requires very high velocities. Injection of such neutron stars might be restricted to a phase of the early galaxy, or it may continue to the present. We discuss several observational constraints that address the question presented in the title.
Managing medical complications and recurrence after surgery for Crohn’s disease

Each of the medical and surgical therapies for Crohn's disease has inherent advantages and disadvantages that must be balanced for patients with moderate to severe disease. Most patients with Crohn's disease require surgery at some point during the lifelong illness, but surgical therapy is not curative for most patients, as postoperative recurrence of Crohn's disease is common and can pose diagnostic and therapeutic challenges. Disease monitoring and appropriate prophylaxis are necessary in patients at high risk.
Monitoring of pre-release cracks in prestressed concrete using fiber optic sensors

Prestressed concrete experiences low to no tensile stresses, which results in limiting the occurrence of cracks in prestressed concrete structures. However, the nature of construction of these structures requires the concrete not to be subjected to the compressive force from the prestressing tendons until after it has gained sufficient compressive strength. Although the structure is not subjected to any dead or live load during this period, it is influenced by shrinkage and thermal variations. Thus, the concrete can experience tensile stresses before the required compressive strength has been attained, which can result in the occurrence of “pre-release” cracks. Such cracks are visually closed after the transfer of the prestressing force. However, structural capacity and behavior can be impacted if cracks are not sufficiently closed. This paper researches a method for the verification of the status of pre-release cracks after transfer of the prestressing force, and it is oriented towards achievement of Level IV Structural Health Monitoring (SHM). The method relies on measurements from parallel long-gauge fiber optic sensors embedded in the concrete prior to pouring. The same sensor network is used for the detection and characterization of cracks, as well as the monitoring of the prestressing force transfer and the determination of the extent of closure of pre-release cracks. This paper outlines the researched method and presents its application to a real-life structure, the southeast leg of Streicker Bridge on the Princeton University campus. The application structure is a curved continuous girder that was constructed in 2009. Its deck experienced four pre-release cracks that were closed beyond the critical limits based on the results of this study.
The role of visual impulses in the control of eye muscle activity

Abstract Eye movements were induced by electrical stimulation of anterior and posterior cortical eye fields and anterior and posterior brain stem sites in cats. Electromyographic recordings from the eye muscles were used to evaluate the interaction between the electrically induced activity and photic stimuli. Eye movements induced from the frontal cortex and the posterior portion of the brain stem were facilitated by photic stimulation. Eye movements induced from the posterior cortex and anterior brain stem were not affected. Optimal facilitation was obtained with a photic stimulus frequency of 10 per sec with no effect below 4 per sec and above 20 per sec. Changing the direction of the infalling light in the direction of the induced eye movement further facilitated the eye motor neuron discharge.
Use of aluminum strips to fabricate verification jig for an implant-supported fixed partial denture

Verification of the accuracy of the master cast for an implant-supported fixed partial denture will reduce the chair time and laboratory costs of implant prosthodontic treatment. A wire is usually luted in the mouth to machined components that have been secured to the implants, and the luted assembly is then transferred to the cast to evaluate the positional accuracy of the implant analogs. Unless this wire is dead soft, inaccuracies as a result of elastic memory of the wire can occur. Also, if the wire is not completely rigid, it can be distorted during handling. This article describes a more reliable verification jig for an implant-supported fixed partial denture that can be fabricated with 1.5 mm thick aluminum strips that are luted to the implant components. The use of two aluminum strips creates a metal framework that is rigid and not easily distorted. Also the aluminum pieces do not have elastic memory because they were cut and not bent to shape.
Superconformal and Super {Kac-Moody} Invariant Quantum Field Theories in Two-dimensions

Abstract Two-dimensional quantum field theories invariant under the superconformal and super Kac-Moody transformations are constructed, generalizing the construction of conformal field theories following Belavin-Polyakov-Zamolodchikov. The linear differential equation for the multipoint correlation is constructed and four-point functions are explicitly calculated using the global OSp(2,1) invariance.
Critical infrastructure protection: The vulnerability conundrum

Critical infrastructure and key resources (CIKR) refer to a broad array of assets which are essential to the everyday functionality of social, economic, political and cultural systems in the United States. The interruption of CIKR poses significant threats to the continuity of these systems and can result in property damage, human casualties and significant economic losses. In recent years, efforts to both identify and mitigate systemic vulnerabilities through federal, state, local and private infrastructure protection plans have improved the readiness of the United States for disruptive events and terrorist threats. However, strategies that focus on worst-case vulnerability reduction, while potentially effective, do not necessarily ensure the best allocation of protective resources. This vulnerability conundrum presents a significant challenge to advanced disaster planning efforts. The purpose of this paper is to highlight the conundrum in the context of CIKR.
Variable capacity sizing and selection of connections in a facility layout

The variable capacity sizing and selection of connections in the facilities design context is discussed (to the best knowledge of the authors) for the first time in the open literature. A connection is defined as the connected part that links di1erent sets of departments through which some interdepartmental material flows must go. The goal of the problem is to select the location and capacity of the connections (and to assign the flows) so as to minimize the sum of the fixed connection installation costs and material movement cost in the material handing system. Mathematical programming formulations are presented for continuous and discrete capacity options. For the continuous unbounded capacity case, we prove that it can be reduced to the uncapacitated fixed charge facility location problem. For the discrete capacity case, a Lagrangian relaxation-based solution approach is developed. It provides a 'good' feasible solution as well as a lower bound for assessing the optimality gap. Computational results ar...
Real‐time, nonlinear control of a constrained, nonminimum‐phase process

This article presents the first real-time implementation of a recently-developed model-based control method on a pilot-scale, multivariable, liquid-level process that exhibits inverse response and whose actuators can be saturated. Issues in real-time implementation of the control method are discussed, as well as a controller tuning procedure. Two model-based controllers are implemented: one is derived using the process outputs; the other is derived using auxiliary outputs. Servo and regulatory responses presented show the differences in the performance of the two controllers. In real time, one of the model-based controllers eliminates inverse response in one controlled output at the expense of yielding a larger inverse response in the other controlled output. This inverse-response elimination is a real-time validation of the linear and nonlinear theoretical results reported in the systems literature.
Assessment of depot leuprolide acetate dose-adequacy for central precocious puberty

The development of GnRH analogs (GnRHa) has made it possible to treat children with central precocious puberty (CPP). This treatment may prevent adult short stature due to premature epiphyseal fusion. Achievement of this goal, however, is dependent upon adequate suppression of gonadal steroid production as a result of GnRHa-induced pituitary de- sensitization and decreased gonadotropin release. A depot for- mulation of a GnRHa (leuprolide acetate (dLA)) is being used by many clinicians for the treatment of CPP, but studies to establish the optimal dose of dLA have not been performed. In this study we evaluated the effectiveness of dLA (7.5 mg, im, every 4 weeks). Six children (7-10 yr old) with CPP treated with dLA were assessed clinically and divided into two groups: A (incompletely suppressed) and B (well suppressed). Each group had overnight blood sampling and a GnRH stimulation test the following morning. LH pulses were analyzed and compared to 11 normal prepubertal children. Mean LH concentration, LH curve area, LH pulse frequency, and mean LH pulse amplitude were significantly greater (P < 0.03) in group A than in group B or the normal prepubertal children. There was no significant difference among the three groups in GnRH-stimulated peak LH release. These results indicate that dLA (7.5 mg, im, every 4 weeks) does not produce complete desensitization in all chil- dren with CPP and suggest that overnight monitoring of LH release is more sensitive than GnRH'stimulation testing for the assessment of dLA dose adequacy. (J Clin Endocrinol Metab 74: 1208-1209,1992)
Spatial distribution of earthquakes and subduction of the Nazca plate beneath South America

A detailed study of the spatial distribution of precisely located hypocenters of South American earthquakes that occurred between lat 0° and 45°S shows that the data can be explained by the simple model of a descending oceanic plate beneath a continental plate and that the following conditions obtain: (1) The hypocenters clearly define five segments of inclined seismic zones, in each of which the zones have relatively uniform dips. The segments beneath northern and central Peru (about lat 2° to 15° S) and beneath central Chile (about lat 27° to 33° S) have very small dips (about 10°), whereas the three segments beneath southern Ecuador (about lat 0° to 2°S), beneath southern Peru and northern Chile (about lat 15° to 27°S), and beneath southern Chile (about lat 33° to 45°S) have steeper dips (25° to 30°). No clear evidence exists for further segmentation of the descending Nazca plate beneath South America. If the two flat segments are in contact with the lower boundary of the continental plate, the thickness of that plate is less than approximately 130 km. This is in marked contrast to the reports of thicknesses exceeding 300 km for the South American continental plate. (2) There is considerable seismic activity within the upper 50 km of the overriding South American plate. This seismic activity is well separated from the inclined seismic zones and probably occurs in the crustal part of the South American plate. Thus, hypocenters in South America are not evenly distributed through about a 300-km-thick zone as previously described. (3) A remarkable correlation exists between the two flat segments of the subducted Nazca plate and the absence of Quaternary volcanism on the South American plate. (4) The transition from the flat Peru segment to the steeper Chile segment is abrupt and is interpreted as a tear in the descending Nazca plate. The tear is located approximately beneath the northern limit of the Altiplano (a high plateau in the Andes), and about 200 km south of the projection of the oceanic Nazca ridge down the subduction zone. (5) A gap in seismic activity exists between depths of 320 and 525 km.
Looptop and footpoint impulsive hard X-rays and stochastic electron acceleration in flares

Abstract The discovery of hard X-rays from tops of flaring loops by the HXT of Yohkoh represents a significant progress in the understanding of solar flares. This report describes the properties of 20 limb flares observed by Yohkoh from October 1991 to August 1998, 15 of which show detectable impulsive looptop emission. Considering the finite dynamic range (about a decade) of the detection it can be concluded that looptop emission is a common feature of all flares. The light curves and images of a representative flare are presented and the statistical properties of the footpoint and looptop fluxes and spectral indices are summarized. The importance of these observations, and those expected from RHESSI with its superior angular, spectral, and temporal resolution, in constraining the acceleration models and parameters is discussed briefly.
Molecular weights of coliphages and coliphage DNA: IV. Molecular weights of DNA from bacteriophages T4, T5 and T7 and the general problem of determination of M☆

Molecular weights (M) of the DNA from Escherichia coli bacteriophages T4, T5 and T7 are obtained by averaging the values from several methods. From these values and data for molecular length (l) under specific conditions of preparation for electron microscopy, Ml is derived. The possibility that Ml is not constant for all DNA molecules is discussed. Using sedimentation data an equation relating S20,w0 and M for bulk sedimentation and a second equation for sedimentation in sucrose gradients are presented. The general problems of measurement of M, Ml and S20,w0 and the current state of affairs are discussed.
Use of a novel mechanical rinsing and aspiration thrombectomy device for treatment of deep venous and arteriovenous graft thrombosis.

The KPS Rinspirator (Kerberos Proximal Solutions, Cupertino, Calif.) is a new thrombectomy device that operates by manually controlled, simultaneous, intravessel infusion and aspiration of fluid to cause localized clot dissolution. We evaluate the ability of the KPS Rinspirator to treat acute (
Characterization of apparent superluminal effects in the focus of an axicon lens using terahertz time-domain spectroscopy

We describe time-resolved measurements of the propagating interference pattern at the focus of an axicon lens. The technique of terahertz time-domain spectroscopy permits a direct observation of the electric field within the line focus formed by a converging conical wave front. We extract the apparent superluminal velocity of this pulse from the peak of the time-domain waveform, and also in the frequency domain by Fourier transform. From these measurements, we conclude that pulse reshaping, arising from strong frequency-dependent propagation effects, does not play a substantial role. As a result, tracking the peak of the pulse in the time domain is a valid method for determining the average group velocity of the disturbance. We also elucidate a new mechanism which influences the value of the superluminal velocity, involving the curvature of the incident wave front.
The effects of cervical application of inhibitors of inducible nitric oxide synthase, cyclooxygenase-1, and cyclooxygenase-2 on delivery in rats

Abstract Objective: To investigate the effect of cervical application of nonselective and selective inhibitors of nitric oxide synthases— N -nitro-L -arginine methyl ester, L - N -iminoethyl-lysine, and aminoguanidine—as well as inhibitors of cyclooxygenases—indomethacin, and nimesulide—on timing of delivery and fetal death and disease in pregnant rats. Study Design: In a series of experimental protocols, timed-pregnant Sprague-Dawley rats (length of pregnancy, 22 days) were randomly allocated to daily cervical applications of (1) 0.04 mg (n = 6), 0.4 mg (n = 6), 4 mg (n = 6), or 40 mg (n = 6) L - N -iminoethyl-lysine or vehicle (n = 12) on days 19 to 22 of pregnancy; (2) 50 mg aminoguanidine (n = 6), 150 mg aminoguanidine (n = 6), or vehicle (n = 10) on days 19 to 22 of pregnancy; (3) 3 mg indomethacin (n = 6) or vehicle (n = 6) on days 19 to 22 of pregnancy; (4) 12.5 mg/kg nimesulide (n = 8), 25 mg/kg nimesulide (n = 8), 50 mg/kg nimesulide (n = 12), or vehicle (n = 12) on days 19 to 22 of pregnancy and 50 mg/kg nimesulide (n = 23) or vehicle (n = 23) on days 14 to 22 of pregnancy; (5) 50 mg/kg nimesulide (n = 10), 50 mg aminoguanidine plus 50 mg/kg nimesulide (n = 10), 50 mg aminoguanidine (n = 10), or vehicle (n = 10) on days 14 to 22 of pregnancy. The following variables were evaluated: proportion of animals that were delivered on day 23, time to delivery of the first pup (midnight on day 22 was considered to be 0 hour), number of stillborn pups, and average pup weight of each litter. Results: Unlike L - N -iminoethyl-lysine, aminoguanidine, and indomethacin, 50 mg/kg nimesulide applied on the cervix daily for 8 days significantly increased the proportion of animals that were delivered on day 23 (18 of 23 versus 7 of 23; P =.003) and the time to delivery of the first pup by a mean of 10.8 hours ( P P =.008). Simultaneous application of aminoguanidine and nimesulide significantly ( P =.008) prolonged pregnancy to a degree similar to nimesulide alone. The experiment with N -nitro-L -arginine methyl ester was aborted because of severe maternal side effects. Unlike pups in the L - N -iminoethyl-lysine, aminoguanidine, and nimesulide groups, significantly more pups in the indomethacin group died in utero compared with the control group (36.1% versus 3.1%; P P Conclusions: In an animal model, nimesulide was effective in delaying the onset of labor, was well tolerated during pregnancy, and affected cervical ripening directly independent of progesterone withdrawal. Conversely, cervical application of nitric oxide synthase and nonselective cyclooxygenase inhibitors do not extend the duration of pregnancy in the dosages studied, and some are associated with significant adverse effects in the mothers and fetuses. (Am J Obstet Gynecol 2001;185: 959-65.)
Zinc-induced Inactivation of the Yeast ZRT1 Zinc Transporter Occurs through Endocytosis and Vacuolar Degradation

The ZRT1 gene encodes the transporter responsible for high affinity zinc uptake in yeast. ZRT1 is transcribed in zinc-limited cells and its transcription is repressed in zinc-replete cells. In this report, we describe a second, post-translational mechanism that regulates ZRT1 activity. In zinc-limited cells, ZRT1 is a stable, N-glycosylated plasma membrane protein. Exposure to high levels of extracellular zinc triggers a rapid loss of ZRT1 uptake activity. Our results demonstrate that this inactivation occurs through zinc-induced endocytosis of the protein and its subsequent degradation in the vacuole. Mutations that inhibit the internalization step of endocytosis also inhibited zinc-induced ZRT1 inactivation and the major vacuolar proteases were required to degrade ZRT1 in response to zinc. Furthermore, immunofluorescence microscopy showed that ZRT1 is localized to the plasma membrane in zinc-limited cells and that the protein is transferred to the vacuole via an endosome-like compartment upon exposure to zinc. ZRT1 inactivation is a relatively specific response to zinc; cadmium and cobalt ions trigger the response but less effectively than zinc. Moreover, zinc does not alter the stability of several other plasma membrane proteins. Therefore, zinc-induced ZRT1 inactivation is a specific regulatory system to shut off zinc uptake activity in cells exposed to high extracellular zinc levels thereby preventing overaccumulation of this potentially toxic metal.
Variational solutions for the discrete nonlinear Schrödinger equation

The interaction and propagation of optical pulses in a nonlinear waveguide array is described by the discrete nonlinear Schrodinger equation(1)i@?"z@j"n=-D(@j"n"+"1+@j"n"-"1-2@j"n)-@c|@j"n|^2@j"n,where D is a dispersion (or diffraction) coefficient, and @c is a measure of the nonlinearity. By means of the variational approximation, we study the discrete soliton solutions of this equation. We use a trial function which contains six parameters, corresponding to: position, phase, amplitude, wavevector (velocity), chirp, and width. With this trial function, we can analytically average the Lagrangian, and then by varing the six parameters, obtain the evolution equations for these six parameters, within the variational approximation. Integration of these equations would give, within the variational approximation, the motion of a moving discrete soliton. Requiring all parameters to be stationary, one obtains the conditions for constructing the solution of the stationary discrete soliton. Here we treat the stationary variational solutions. For them, we find for small amplitudes, that there is only one stationary soliton, a doublet solution, which in the continuous limit, becomes the usual nonlinear Schrodinger soliton. At a certain critical amplitude, there is a pitchfork bifurcation, above which the stable singlet soliton apprears, with the doublet soliton becoming unstable. Lastly, using the variational solutions as a starting point, we iterate the full Lagrangian to obtain numerically, the exact discrete soliton solutions. Comparison between the variational and the exact numerical discrete soliton solutions will be made. From these results, we are also able to make some general and important remarks concerning the validity and utility of the found variational soliton solutions.
Stabilization of the avian progesterone receptor by inhibitors.

Abstract The avian progesterone receptor is known to be very temperature-labile; its hormone binding activity is lost within minutes at 37°C. However, when the receptor is first treated with pyridoxal 5'-phosphate, in the presence of sodium borohydride, the receptor is stabilized dramatically and can be incubated for up to 2 h at 37°C without loss of activity. Pyridoxal 5'-phosphate is known to block the binding of receptor to ATP-Sepharose, apparently by a Schiff base interaction with the receptor. Other such inhibitors were also tested for any stabilizing effect. Two of these, o-phenanthroline and aurintricarboxylic acid, decreased the stability of the receptor, while a very significant stabilization was observed after treatment with sodium molybdate. In addition to this effect, sodium molybdate appears to block activation or transformation of the progesterone receptor to the form which is able to bind to ATP-Sepharose. Once the receptor is in this activated form, sodium molybdate is no longer inhibitory whereas pyridoxal 5'-phosphate is still a potent inhibitor of ATP-Sepharose binding. These results indicate that the two stabilizing agents act through different mechanisms.
Design of an agonist-antagonist active knee prosthesis

The majority of commercial prosthetic knees are passive in nature and therefore cannot replicate the positive mechanical work exhibited by the natural human knee in early and late stance. In contrast to traditional purely dissipative prosthetic knees, we propose a biomimetic active agonist-antagonist structure designed to reproduce both positive and negative work phases of the natural joint while using series elasticity to minimize net energy consumption. We present the design and physical implementation of the active knee prosthesis prototype.
Perceived Satisfaction With Social Support and Depressive Symptoms in Perinatal Latinas

Purpose: This study examined the relationship between satisfaction with social support and postpartum depressive symptoms in Latinas. Design: A secondary data analysis of 62 women at “high risk” or...
Asthma prevalence and morbidity among rural Iowa schoolchildren.

Abstract Background There are conflicting findings about the prevalence of asthma among farm and nonfarm children. Objectives We sought to estimate asthma prevalence and morbidity and determine differences between farm and nonfarm children. Methods The study population consisted of all children aged 6 to 14 years enrolled in 10 school districts in 2 noncontiguous rural Iowa counties from 2000 through 2002. The mailed parental screening questionnaire included the International Study of Asthma and Allergies in Childhood core questionnaire, items from the Functional Severity Index, and items on physician diagnosis and medication and urgent care use. Results The response rate was 86.6%. The 12-month prevalence of wheeze was 19.1%. Self-reported physician diagnosis of asthma was reported by 13.4%. On multivariable analysis controlling for age, sex, and county, children who lived on farms were less likely than those who lived in town to have ever wheezed (odds ratio, 0.71; 95% CI, 0.58-0.87) or to have wheezed during the past year (odds ratio, 0.77; 95% CI, 0.60-0.98). However, this protective association with farming was only observed in one of the study counties. Among those who wheezed, farm and nonfarm children were equally likely to have been given a diagnosis of asthma and had comparable morbidity. Conclusion By using a standardized questionnaire with a high response rate in this large, rural, population-based study, asthma prevalence rivaled that in large Midwestern cities. Unmeasured risk factors might account for the apparent protective effect in Keokuk County. These findings cast doubt on a protective effect of rural life for the development of childhood asthma.