cssi/SciSciGPT-SciSciNet huggingface dataset:
Solar System Exploration Augmented by Lunar and Outer Planet Resource Utilization: Historical Perspectives and Future Possibilities

Establishing a lunar presence and creating an industrial capability on the Moon may lead to important new discoveries for all of human kind. Historical studies of lunar exploration, in-situ resource utilization (ISRU) and industrialization all point to the vast resources on the Moon and its links to future human and robotic exploration. In the historical work, a broad range of technological innovations are described and analyzed. These studies depict program planning for future human missions throughout the solar system, lunar launched nuclear rockets, and future human settlements on the Moon, respectively. Updated analyses based on the visions presented are presented. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal propulsion, nuclear surface power, as well as advanced chemical propulsion can significantly enhance these scenarios. Robotic and human outer planet exploration options are described in many detailed and extensive studies. Nuclear propulsion options for fast trips to the outer planets are discussed. To refuel such vehicles, atmospheric mining in the outer solar system has also been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and hydrogen can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and hydrogen (deuterium, etc.) were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses have investigated resource capturing aspects of atmospheric mining in the outer solar system. These analyses included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. With these two additional gases, the potential for fueling small and large fleets of additional exploration and exploitation vehicles exists.
A multi-IMPATT injection-locked oscillator at 35 GHz

A 35-GHz solid-state injection-locked oscillator giving 38 W peak power with 30% duty cycle is described. The power source utilizes a total of ten GaAs IMPATT (impact avalanche and transit time) diodes grouped in two stages. The performance of the source as well as the systematic design and measurement procedures used to develop the multidiode cavities used are discussed. >
Stimulation of locomotor activity by intra-accumbens AMPA is not inhibited by neonatal 6-hydroxydopamine-induced lesions.

Abstract The involvement of dopamine in the hypermotility responses to amphetamine s.c. or AMPA injected into the nucleus accumbens was evaluated in adult rats depleted of dopamine as neonates with 6-hydroxydopamine. The hypermotility response to amphetamine was markedly inhibited in the lesioned animals, while that to AMPA was enhanced. In addition, the hypermotility produced by AMPA in these rats was not inhibited by sulpiride + SCH-23390; however, it was inhibited completely by α-methyl-p-tyrosine. These results suggest that the hypermotility produced by AMPA requires endogenous dopamine, but is mediated by a different mechanism than that produced by amphetamine.
Using ecological momentary assessment to understand a construction worker’s daily disruptions and decisions

Capturing the momentary decisions and actions made by construction workers in response to workflow disruptions is challenging because, until now, there has not been a minimally disruptive data collection method that allows workers to identify their decision process ‘in the moment’. However, an Ecological Momentary Assessment (EMA) method—designed to capture momentary work experiences in natural settings—can provide researchers with detailed information about the daily challenges experienced by workers during the course of performing their tasks. An explanation of the method is provided, along with examples of the types of research questions that can be addressed and appropriate analysis techniques. The EMA method is being used on a federally funded research programme in the United States that is investigating how construction workers adapt to workflow disruptions by improvising their decisions and actions. Consequently, this article demonstrates the use of the method by presenting an idiographic study of ...
Pulse Oximetry for Tapering Supplemental Oxygen in Hospitalized Patients: Evaluation of a Protocol

In a randomized study, we determined the clinical and financial effects of replacing arterial blood gas measurements with finger pulse oximeter readings during the process of tapering supplemental oxygen in hospitalized patients. The 16 patients in the control group, whose management followed conventional practice in our hospital, received a total of 57 arterial blood gas measurements during the 6.6 (mean) days it took for them to taper to their discharge supplemental oxygen level (usually room air). The 13 patients randomized to the oximeter study group had their arterial oxygen saturation monitored by pulse oximetry. The physicians of patients in the oximeter group were at liberty to obtain arterial blood gas determinations during the study if they desired. The oximeter study group had fewer (p
Hydrogen Bond Energetics: A Simulation and Statistical Analysis of N-Methyl Acetamide (NMA), Water, and Human Lysozyme†

Energy minimization and molecular dynamics simulations have been used to study hydrogen bond interactions in dimers of N-methylacetamide (NMA), in NMA−water complexes, and in human lysozyme. The potential energy surface is found to be determined by the interactions of entire peptide groups (OCi-1−Ni−H) or water molecules rather than by single donor and acceptor groups. The contact distance between the donor hydrogen and the acceptor as well as the angle of the bond at the donor hydrogen are the principal geometric parameters that describe the hydrogen bond. Potential energy surfaces were also examined in the presence and absence of explicit solvent molecules. The results suggest that both competing hydrogen bond interactions and the thermal motion of atoms broaden the distribution of low energy donor−acceptor contacts. Comparisons are made with a statistical analysis of mainchain hydrogen bond donor and acceptor contacts in high-resolution crystal structures of nonhomologous proteins. Interaction energies...
Minimization by coordinate descent

We examine the minimization of anN-dimensional real-valued function using the coordinate descent method. We impose conditions on the function under which the method converges; furthermore, by specializing our class of functions, we obtain the rate of convergence. We also present some examples from classical approximation theory where this method applies. A computational example is also given.
ISRU Soil Mechanics Vacuum Facility: Soil Bin Preparation and Simulant Strength Characterization

Testing in relevant environments is key to exploration mission hardware development. This is true on both the component level (in early development) and system level (in late development stages). During ISRU missions the hardware will interface with the soil (digging, roving, etc) in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, conditioned simulant bed. However, in earth-based granular media, such as lunar soil simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. The Vacuum Facility #13, a mid-size chamber (3.66m tall, 1.5m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64m deep by 0.914m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types have been used. An electric cone penetrometer was used to measure simulant strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5Torr, regardless of the pump rate. However, slow off gassing of the soil lead to long test times, a full week, to reach 10-5Torr. This work highlights the need for robotic machine-simulant hardware and operations in vacuum to expeditiously perform (sub-)systems tests.
Barley, Oat, and Cereal–Pea Mixtures as Dryland Forages in the Northern Great Plains

Oat (Avena spp.) is a popular cereal forage in cool semiarid regions. Barley (Hordeum vulgare L.) has produced equal or greater amounts of superior quality forage in subhumid regions. The importance of cereal crop, cultivar, and plant part on forage production was determined in low-soil-N environments in southwestern North Dakota. Barley and oat cultivars, along with intercrops of pea (Pisum sativum L. subsp. sativum) with barley and oat, were compared for forage yield and quality over 2 yr. Forage dry matter (DM) yield averaged 3.84 Mg ha -1 for oat compared with 2.91 Mg ha -1 for barley while crude protein (CP) concentration of oat forage averaged 61 g kg -1 compared with 90 g kg -1 for barley (P < 0.05). No difference in forage N yield occurred between barley and oat. Acid detergent fiber and neutral detergent fiber concentrations averaged 39 and 41 g kg -1 lower, respectively, for barley compared with oat forage while Ca and P concentrations were higher for barley forage. Cultivar selection within each crop species generally did not affect forage yield or quality. The relative contributions of stem, inflorescence, leaf blade, and leaf sheath to forage yield were similar between cereal species and averaged 20, 44, 14, and 22%, respectively. Intercropping with pea increased forage and N yield. These results suggest that forage yield is reduced but quality is enhanced when oat is replaced with barley in low-soil-N, unfertilized environments. Furthermore, the results indicate that forage yield and quality can be enhanced by intercropping barley or oat with pea.
Immunologic assessment of the immunodeficient

Although this article will deal primarily with assessment of deficiencies of the lymphoid system, it is important to remember that host defense is also dependent upon the phagocytic cells, the macrophages and polyrnorphonuclear leukocytes. Significant abnormalities in either of these systems can result in altered susceptibility to infection, which is of as much clinical moment as deficiencies of the lymphocytes themselves. Extensive literature has accumulated on the phagocytic cells, and the reader is referred to recent reviews for further information.‘* *
Polymeric glycoconjugates protect and activate macrophages to promote killing of Bacillus cereus spores during phagocytosis

Diseases caused by Bacillus spores might be attenuated if macrophages were able to kill the spores on exposure. Glycoconjugate-bearing polymers, which have been shown to bind to Bacillus spores, were tested for modulation of phagocytosis of B. cereus spores. Without glycoconjugate activation, murine macrophages were ineffective at killing Bacillus spores during phagocytosis. In the presence of glycoconjugates, however, the macrophages efficiently killed the organisms. The glycoconjugates were shown to have a protective influence, sparing macrophages from spore-induced cell death. Very low concentrations of the glycoconjugates prevented macrophage cell death, as shown by lactate dehydrogenase (LDH) release and trypan blue assays. Increased levels of inducible nitric oxide (NO) production by the macrophages in the presence of glycoconjugates suggested that the glycoconjugates provide an activation signal to the macrophages. These results suggest that glycoconjugates promote the killing of Bacillus spores by blocking spore-induced macrophage cell death, while increasing their activation level. Polymeric glycoconjugates may suggest novel approaches to improve existing vaccines as well as prevent and treat infections incurred through either B. cereus or B. anthracis spores.
Atherotome Dislodgement and Successful Retrieval During Cutting Balloon Pulmonary Angioplasty

Cutting balloons (CBs) are beneficial for dilation of resistant branch pulmonary artery (PA) stenosis in children.1 There are rare reports of atherotome fracture2 and a Food and Drug Administration adverse event report of a fractured atherotome dislodging and remaining in the patient.3 We report CB atherotome dislodgement and embolization with successful retrieval in a patient with Alagille syndrome and branch PA stenosis. A 7-year-old girl with Alagille syndrome, systemic hypertension, branch PA stenosis, and a small patent ductus arteriosus was referred for left PA dilation and percutaneous patent ductus arteriosus closure to optimize her cardiac status before liver transplantation. Angiograms of the left PA demonstrated stenosis of the proximal left lower PA (LLPA) measuring 3.07 mm, with the distal LLPA measuring 6.2 mm. An 8-mm balloon (Sterling; Boston Scientific) was inflated to 8 atm with a 6-mm waist (Figure 1). Through a 7F long sheath (Check-Flo Performer Introducer, Mullins Design; …
Mechanism of precise tissue ablation with minimal side effects (under confined stress conditions of irradiation)

Pulsed laser ablation of biological tissues under confined stress conditions (PACS) is demonstrated to be precise tissue removal with minimal thermal and mechanical damage to adjacent tissue layers. PACS was described based on results obtained with four complementary techniques: (1) laser-flash photography, (2) time-resolved stress detection (TRSD), (3) laser Michelson interferometry, and (4) pendulum recoil measurements. Comparison of ablation process was made between aqueous solutions and collagen gels. Experiments demonstrated two distinct ablation stages with different ablative forces that drive material ejection at temperatures substantially below 100 degree(s)C. The first stage is associated with the ejection of thin subsurface layer of the irradiated volume. The material ejection from a superficial layer (d << 1/(mu) eff) is caused by a rapid growth of cavitation bubbles produced by laser-induced thermoelastic expansion in irradiated volume. The second, delayed stage of material removal occurs due to the collapse of coalesced cavitation bubbles in the depth (d <EQ 1/(mu) eff) of irradiated volume. Collapse of large cavities with subsequent generation of turbulent motion toward medium surface can stimulate jets in liquids and plumes of debris in gels. Depending on water content and mechanical properties of a medium, the second stage may be either very pronounced (aqueous solutions) or practically absent (stiff gels). Estimates predict the possibility to remove precisely only a monolayer of cells employing PACS with an appropriate combination of laser wavelength and pulse duration.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Auditory inhibitory gating in the amygdala: Single-unit analysis in the behaving rat

Inhibitory sensory gating has been proposed to be a fundamental physiological process that filters neural input. Its temporal properties could allow for a rapid influence on vigilance and attention processes. Inhibitory mechanisms are reflected by reductions in neural responsiveness to repeated and well-predicted stimuli; for auditory gating, this translates into an inhibition of the neural activation to subsequent tone stimuli embedded within sequential and identical tone presentations. Here we expand previous neurophysiological data on inhibitory gating by examining gating in the amygdala using single-unit recording in freely moving animals. Previous data have shown the amygdala to be important in mediating rapid auditory sensory processing involved in emotional conditioning. We measured inhibitory gating with two matching auditory tones presented in a repetitive fashion (10 ms tones, ISI = 500 ms and 10 s between pairs) for 1 h (360 pairs). The majority of the tone responsive units showed inhibitory gating (78/95 units) located in both the medial and lateral subnuclei of the amygdala. Different types of tone responses were gated, including both shorter- and longer-duration excitatory tone responses as well as inhibitory tone responses. Different degrees of gating were found ranging from 100% inhibition (complete gating category) to 25% inhibition (graded gating category). The degree of gating varied over short-term and long-term time intervals. These findings demonstrate the existence of inhibitory gating in the amygdala and provide a detailed description of the basic properties of this rapid neural inhibition that could play an important role in filtering stimulus input.
Catheter irrigation for treatment of pyogenic closed space infections of the hand.

Abstract We studied 29 patients admitted to San Francisco General Hospital with flexor tenosynovitis (6 patients), pyogenic arthritis (17 patients), and deep space infections (6 patients). All patients underwent catheter irrigation of the infected space for at least 48 hours postoperatively. In 23 patients no further operative procedures were required. Infection was controlled without amputation in all patients. Median hospital stay was the same for patients with tenosynovitis, pyogenic arthritis, and deep space infections (8 days). Thirteen of 17 patients followed for at least one month, including 7 of 9 patients with pyogenic arthritis, were found to have regained at least 50% of baselin motion. In this series the outcome of treatment for pyogenic arthritis was comparable to that for tenosynovitis. We believe that catheter irrigation should be considered as a treatment option in pyogenic arthritis. A prospective trial comparing the efficacy of treatment modalities for pyogenic arthritis is indicated.
Characterization of breakdown delay and memory effects in high power microwave dielectric window discharges

Summary form only given. Development of high power microwave (HPM) distributed discharge limiters relies critically on minimizing the delay time between HPM incidence and diffuse plasma creation. We present a series of pulsed plasma experiments conducted in neon, argon, and a 9∶1 mixture of the two gases from 50–760 torr. Breakdown is achieved by illuminating a gas cell with a train of ∼25kW, ∼2 kV/cm, 800ns-long pulses at 41Hz repetition rate. The results suggest that surface charge accumulation on the gas cell's polycarbonate window from many low density precursor discharges eventually results in rapid (&#60;30ns), high density, discharge formation. The number of precursor pulses required to form these high density discharges is significantly reduced following a previous high-density discharge.
Regulation of synaptic transmission in the central nervous system: long-term potentiation

Article de synthese sur le role de la potentialisation a long terme dans la regulation de la transmission synaptique dans le systeme nerveux central. Role de l'hippocampe dans la memoire et dans l'apprentissage
Ultrastructural and cytochemical effects of trypan blue on TSH stimulation of thyroid follicular cells.

Ultrastructural and cytochemical techniques were used to study the effects of trypan blue on the response of mouse-thyroid cells to exogenous stimulation by thyroid stimulating hormone (TSH). The dye delayed the response to TSH resulting in decreased colloid-droplet formation in the apical region of the cells. The dye did not stop the shift of trimetaphosphatase activity from lysosomes to phagolysosomes. The duration of the TSH-induced response was shorter in the dye treated thyroids. Small vesicles, with trimetaphosphatase reaction product, were found near Golgi elements, phagolysosomes, and the plasma membrane facing the intercellular space of adjacent follicle cells. Their enzyme activity was not affected by exposure to the dye. These data indicate that the primary effect of trypan blue on the response of thyroid follicle cells to TSH stimulation was reduced endocytosis in the apical region resulting in fewer colloid droplets.
Pretreatment laparoscopic appearance of the liver can predict response to combination therapy with interferon alpha 2B and ribavirin in chronic hepatitis C.

Abstract Background: The aim of this study was to determine whether the pretreatment laparoscopic appearance of the liver is an additional predictor of response to combination therapy with interferon and ribavirin in patients with hepatitis C. Methods: A retrospective review was performed of 112 patients (61 men, 51 women [ratio 1.3:1]; mean age 50 [10] years, range 15-73 years) with untreated hepatitis C, without other causes of liver disease, who underwent diagnostic laparoscopy before combination therapy with interferon and ribavirin for at least 24 weeks with a 24-week post-treatment follow-up. Fifty-nine were white, 37 Hispanic, and 16 African American. Patients were divided into responders and non-responders based on viral clearance. Demographics, genotype, pre-therapy hepatitis C virus RNA, histopathologic, and laparoscopic appearances were analyzed. Results: Ninety-three patients (83%) had genotype 1 with a mean pretreatment hepatitis C virus RNA of 3.2 (2.8) million copies/mL. Thirty-seven (33%) had laparoscopic evidence of cirrhosis, whereas, only 30 (26.4%) had cirrhosis by histopathologic criteria. Patients were treated with interferon and ribavirin (mean dose 10.6 [2.5] mg/kg) for a mean duration of 37.7 (11.4) weeks, depending on response and genotype. A sustained response was observed in 26 (23%) patients; in 12 (11%), there was only a biochemical response (biochemical responder), while 59 (53%) and 15 (13%) were classified, respectively, as non-responders and relapsers. Logistic regression analysis revealed that pretreatment laparoscopic appearance ( p = 0.034) and genotype ( p = 0.002) were significant predictive factors; that is, a lesser extent of fibrosis at laparoscopy and genotypes other than 1 were predictive of a sustained response to combination therapy. Conclusions: Pretreatment laparoscopic appearance alone and genotype are significant predictors of a sustained response to combination therapy in patients with hepatitis C. Laparoscopy and biopsy are complementary for the diagnosis of cirrhosis in hepatitis C.
STAT3 mediates IL-6-induced growth inhibition in the human prostate cancer cell line LNCaP.

BACKGROUND In prostate cancer, we and others have observed distinct phenotypic responses to interleukin-6 (IL-6), which acts either as a paracrine growth inhibitor in the LNCaP cell line or as an autocrine growth stimulator in PC-3, DU145, and TSU cell lines. To understand the underlying mechanism responsible for this phenotypic difference, we investigated differences in the IL-6-induced Janus kinase-signal tranducers and activators of transcription (JAK-STAT) signal transduction pathway between these two phenotypes. METHODS Prostate cancer cell lines were assayed for STAT3 activity by immunoblotting, electorphoretic gel shift assays (EMSA), and a luciferase reporter assay to test for STAT3 protein expression, phosphorylation, DNA binding, and transcriptional activity. To address the physiological role of STAT3, we introduced a dominant-negative mutant of STAT3 into LNCaP cells and assayed the effects of IL-6 on cell growth of this stable transfectant by cell counting, clonogenic assays, and c-myc expression. RESULTS IL-6 induced transcriptional activity of STAT3 only in LNCaP. STAT3 was transcriptionally inactive in PC-3, TSU, and DU145 at the level of protein expression, tyrosine phosphorylation, and DNA binding/transcriptional activity, respectively. An isolated LNCaP subclone containing a dominant-negative mutant of STAT3, LNCaP-SF, did not show STAT3-DNA binding or transcriptional activity. LNCaP-SF exhibited a proliferative response to IL-6 as compared to the control LNCaP-neo clone, which underwent growth arrest. Unlike LNCaP-neo, LNCaP-SF was able form colonies and to maintain c-myc expression in the presence of IL-6. CONCLUSIONS STAT3 transcriptional activation correlates with the growth-inhibitory signal of IL-6 in LNCaP, suggesting that STAT3 transcriptional activity is an important determinant in the different phenotypic responses to IL-6 in prostate cancer. Prostate 42:88–98, 2000. © 2000 Wiley-Liss, Inc.
Thyroid development in relation to the development of endothermy in the red-winged blackbird (Agelaius phoeniceus).

We investigated the development of thyroid function during the transition to endothermy in red-winged blackbirds (Agelaius phoeniceus). Thermoregulatory capabilities of blackbirds improve markedly over their relatively short nestling period (10-12 days), with the most striking improvements occurring between days 6 and 8. We hypothesized that the development of endothermy in these birds is dependent in part on the development of thyroid function. We assessed thyroid development by measuring changes in thyroid gland histology and plasma concentrations of thyroxine (T4) and triiodothyronine (T3) during the nestling period. To gain insight into the role of thyroid maturation in the context of thermoregulation, we compared plasma thyroid hormone profiles in nestlings exposed to cold temperatures to those maintained at thermoneutral temperatures. The overall size of the thyroid (as cross-sectional area) increased during nestling development, with the fastest growth occurring just before the development of endothermy. By day 8, it reached the size typical of that in adults. Follicular cell height of the thyroid glands increased in nestlings up to day 6 and then decreased for the rest of the nestling period. The mean area of individual follicles increased up to day 8 of nestling life and then decreased. Individual nestlings were capable of strong endothermic responses at 7 to 8 days of age and had significantly decreased plasma T4 concentrations following cold exposure, suggesting increased T4 to T3 deiodination to maintain the plasma concentrations of the more metabolically active T3. The patterns of plasma T4 and T3 during nestling development were consistent with those of nestlings of other altricial species of birds that have been studied. Overall, the patterns of thyroid development observed were consistent with the hypothesis that the functional development of the thyroid is critical to the development of endothermic capabilities and that thyroid hormones play a role in endothermic responses to cold temperatures.
Thermophysical measurements on transitionmetal tungstates II. Heat capacities of antiferromagnetic nickel and cobalt tungstates

The heat capacity of nickel tungstate (NiWO,) was measured over the temperature range 5 to 350 K by adiabatic calorimetry, and that of cobalt tungstate (CoW04) from 5 to 550 K. Temperatures of maximum heat capacities for the antiferromagnetic anomalies in cobalt and nickel tungstates were (47.7fO.l) K and (59.80f0.05) K. Excess entropies associated with the antiferromagnetic anomalies were evaluated as R In 2 (1.38 calth K-’ mol-‘) for CoWO, and R In 3 (2.18 calth K-l mol-‘) for NiWOc with the lattice heat capacities of the compounds approximated by that of ZnWO+ In addition, the heat capacity of Cow01 showed a continuing excess heat capacity consistent with a Schottky anomaly from energy levels lying roughly 600 to 3400 calth mol-1 above the ground state. Selected thermal funo tions: G, S”, and -{GO(T)-H”(O)}/7 at 298.15 K are respectively 28.41,30.08, and 14.01 cala K-l mol-’ for CoWO,, and 27.77, 28.51, and 13.21 calth K-l mol-1 for NiWO+
Radioresistant derivatives of an X-ray-sensitive CHO cell line exhibit distinct patterns of sensitivity to DNA-damaging agents

X-ray-resistant clones of the xrs-5 radiosensitive derivative of the CHO-K1 cell line were generated by transfecting cosmid library DNAs into the X-ray-sensitive cells. Transfectants were selected for both a dominant drug resistance marker present in the vector sequences and return to wild-type survival. Three cell lines were isolated which show X-ray survival characteristics similar to parental K1 cells. These revertant lines were examined for their cross-sensitivity to cis-diamminedichloroplatinum(II) (cisplatin) and bleomycin. Although these cell lines reverted with regard to X-ray sensitivity, they retained their sensitivity to cisplatin. Furthermore, changes in bleomycin and X-ray sensitivity did not correlate. There was a positive correlation between return to wild-type radiosensitivity and an increase in the rate of DNA double-strand break rejoining.
THE ROLE OF INFRASTRUCTURE IN THE SUPPLY OF HOUSING

As the housing stock in a city is duplicated, developers must devote greater amounts of resources to the provision of infrastructure. If the production of infrastructure is characterized by decreasing returns to scale, this will cause the price of developable land to increase. The conditions under which an upward-sloping supply curve for housing will result are discussed. Using cross-sectional data for U.S. cities from 1973 to 1982, it is shown that land prices fail to increase with the quantity of construction and that the price elasticity of the supply of housing is infinite.
Mathematical models for the evolution of multigene families by unequal crossing over

Mathematical models of homologous but unequal crossing over between sister chromatids are presented. For mispairing by one repeat, the evolution of a multigene family by unequal crossing over can be represented by a linear birth-death process. The fixation rate of one repeat in a multigene family is estimated. For mispairing by more than one repeat, some approximate results are obtained.
Genetic disorders that masquerade as multiple sclerosis.

There are many genetic disorders that have signs and symptoms suggestive of multiple sclerosis and that may easily be overlooked in the evaluation of both adult and pediatric multiple sclerosis patients. The recognition of a genetic disorder as the cause of a patient's “multiple sclerosis” phenotype has important implications not only for the patient, but often also for others in the patient's family who may be at risk for the same disease. We present here a review of single gene disorders that can masquerade as multiple sclerosis. For each disorder, the major clinical and biochemical characteristics are discussed, together with the appropriate testing to screen for and confirm the diagnosis. In addition, guidelines are presented for when to suspect an underlying genetic condition in a patient with a diagnosis of definite or probable multiple sclerosis. The great variety of genetic disorders that can masquerade as multiple sclerosis and the many implications of a genetic diagnosis underscore the importance of recognizing genocopies of multiple sclerosis. © 1994 Wiley-Liss, Inc.
The effect of ozone exposure upon hepatic and serum ascorbic acid levels in male Sprague‐Dawley rats

Abstract Exposure of male Sprague‐Dawley rats to 0.3 ppm ozone for 3 hours resulted in a time‐delayed increase in serum and hepatic reduced ascorbic acid levels as compared to controls (0.0 ppm O3) which exhibited an immediate increase in hepatic and serum ascorbic levels. After 24 hours ascorbic acid levels in both groups approached but did not return to pre‐exposure values. The immediate increase in ascorbic acid levels in the controls was unexpected and may reflect previously unrecognized chamber and/or handling effects.
Robotically assisted left ventricular epicardial lead implantation for biventricular pacing.

Abstract Objectives Ventricular resynchronization might be achieved in a minimally invasive fashion using a robotically assisted, direct left ventricular (LV) epicardial approach. Background Approximately 10% of patients undergoing biventricular pacemaker insertion have a failure of coronary sinus (CS) cannulation. Rescue therapy for these patients currently is limited to standard open surgical techniques. Methods Ten patients with congestive heart failure (New York Heart Association class 3.4 ± 0.5) and a widened QRS complex (184 ± 31 ms) underwent robotic LV lead placement after failed CS cannulation. Mean patient age was 71 ± 12 years, LV ejection fraction (EF) was 12 ± 6%, and LV end-diastolic diameter was 7.1 ± 1.3 cm. Three patients had previous cardiac surgery, and five patients had a prior device implanted. Results Nineteen epicardial leads were successfully placed on the posterobasal surface of the LV. Intraoperative lead threshold was 1.0 ± 0.5 V at 0.5 ms, R-wave was 18.6 ± 8.6 mV, and impedance was 1,143 ± 261 ohms at 0.5 V. Complications included an intraoperative LV injury and a postoperative pneumonia. Improvements in exercise tolerance (8 of 10 patients), EF (19 ± 13%, p = 0.04), and QRS duration (152 ± 21 ms, p = 0.006) have been noted at three to six months follow-up. Lead thresholds have remained unchanged (2.1 ± 1.4 V at 0.5 ms, p = NS), and a significant drop in impedance (310 ± 59 ohms, p Conclusions Robotic LV lead placement is an effective and novel technique which can be used for ventricular resynchronization therapy in patients with no other minimally invasive options for biventricular pacing.
Agile wide-angle beam steering with electrowetting microprisms

A novel basis for beam steering with electrowetting microprisms (EMPs) is reported. EMPs utilize electrowetting modulation of liquid contact angle in order to mimic the refractive behavior for various classical prism geometries. Continuous beam steering through an angle of 14 degrees (+/-7 degrees ) has been demonstrated with a liquid index of n=1.359. Experimental results are well-matched to theoretical behavior up to the point of electrowetting contact-angle saturation. Projections show that use of higher index liquids (n~1.6) will result in steering through ~30 degrees (+/-15 degrees ). Fundamental factors defining achievable deflection range, and issues for Ladar use, are reviewed. This approach is capable of good switching speed (~ms), polarization independent operation, modulation of beam field-of-view (lensing), and high steering efficiency that is independent of deflection angle.
Seismic performance of steel plate shear walls considering two different design philosophies of infill plates. I: Deterioration model development

AbstractResearch was conducted to investigate the seismic performance of steel plate shear walls (SPSWs) having infill plates designed to resist different percentages of the applied lateral loads. ...
Implications of the ALEPH tau-Lepton Decay Data for Perturbative and Nonperturbative QCD

We use ALEPH data on hadronic {tau} decays in order to calculate Euclidean coordinate space correlation functions in the vector and axial-vector channels. The linear combination V-A receives no perturbative contribution and is quantitatively reproduced by the instanton liquid model. In the case of V+A the instanton calculation is in good agreement with the data once perturbative corrections are included. These corrections clearly show the evolution of {alpha}{sub s} . We also analyze the range of validity of the operator product expansion (OPE). We conclude that the range of validity of the OPE is limited to x{approx}<0.3 fm , whereas the instanton model describes the data over the entire range.
Arterial pH and carbon dioxide tension as indicators of tissue perfusion during cardiac arrest in a canine model

Background and Methods Previous studies have shown that Paco2 and end-tidal CO2 reflect coronary artery perfusion pressures during cardiac arrest. We investigated the relationship of coronary artery perfusion pressure to central arterial pH and Paco2 values during resuscitation from cardiac arrest in a canine model. Twenty-four mongrel dogs were block randomized to three different resuscitation groups after induction of ventricular fibrillation and cardiac arrest: a) standard cardiopulmonary resuscitation (CPR) and advanced life support (n = 8); b) cardiopulmonary bypass (n = 8); or c) open-chest CPR (n = 8). Central arterial blood gases and perfusion pressures were monitored during cardiac arrest and during resuscitation. Results Prearrest blood gases and hemodynamic values were similar between groups. Sixteen dogs from all three groups were successfully resuscitated. Survivors had significantly higher coronary artery perfusion pressure (p =.03), Paco2(p =.015), and lower pH (p =.01) values than nonsurvivors. There was no correlation of pH and Paco2 during mechanical external CPR. However, after institution of the different resuscitation techniques, pH and Paco2 each showed a statistically significant correlation (r2 =.50 and .33, respectively) with coronary artery perfusion pressure. Conclusions Central arterial pH and Paco2 monitoring during cardiac arrest may reflect the adequacy of tissue perfusion during resuscitation and may predict resuscitation outcome from ventricular fibrillation. (Crit Care Med 1992; 20:1302–1308)
The effects of unemployment and the business cycle on absenteeism

Abstract This study, apparently the first of its kind, looks at the relation between unemployment and absenteeism. It is hypothesized that high unemployment is associated with low absenteeism for two reasons: (1) when unemployment is high, layoffs are high and workers laid off are more likely to have been absence-prone than retained workers, and (2) when unemployment is high, currently employed workers, fearing job loss, will avoid absences to decrease their chances of becoming unemployed. Data from the Panel Study of Income Dynamics support both hypotheses.
Design, fabrication and implementation of a novel multi-parameter control microfluidic platform for three-dimensional cell culture and real-time imaging.

New and more biologically relevant in vitro models are needed for use in drug development, regenerative medicine, and fundamental scientific investigation. While the importance of the extracellular microenvironment is clear, the ability to investigate the effects of physiologically relevant biophysical and biochemical factors is restricted in traditional cell culture platforms. Moreover, the versatility for multi-parameter manipulation, on a single platform, with the optical resolution to monitor the dynamics of individual cells or small population is lacking. Here we introduce a microfluidic platform for 3D cell culture in biologically derived or synthetic hydrogels with the capability to monitor cellular dynamics in response to changes in their microenvironment. Direct scaffold microinjection, was employed to incorporate 3D matrices into microfluidic devices. Our system geometry permits a unique window for studying directional migration, e.g.sprouting angiogenesis, since sprouts grow predominantly in the microscopic viewing plane. In this study, we demonstrate the ability to generate gradients (non-reactive solute), surface shear, interstitial flow, and image cellsin situ. Three different capillary morphogenesis assays are demonstrated. Human adult dermal microvascular endothelial cells (HMVEC-ad) were maintained in culture for up to 7 days during which they formed open lumen-like structures which was confirmed with confocal microscopy and by perfusion with fluorescent microspheres. In the sprouting assay, time-lapse movies revealed cellular mechanisms and dynamics (filopodial projection/retraction, directional migration, cell division and lumen formation) during tip-cell invasion of underlying 3D matrix and subsequent lumen formation.
Recovering the toolchain provenance of binary code

Program binaries are an artifact of a production process that begins with source code and ends with a string of bytes representing executable code. There are many reasons to want to know the specifics of this process for a given binary---for forensic investigation of malware, to diagnose the role of the compiler in crashes or performance problems, or for reverse engineering and decompilation---but binaries are not generally annotated with such provenance details. Intuitively, the binary code should exhibit properties specific to the process that produced it, but it is not at all clear how to find such properties and map them to specific elements of that process.In this paper, we present an automatic technique to recover toolchain provenance: those details, such as the source language and the compiler and compilation options, that define the transformation process through which the binary was produced. We approach provenance recovery as a classification problem, discovering characteristics of binary code that are strongly associated with particular toolchain components and developing models that can infer the likely provenance of program binaries. Our experiments show that toolchain provenance can be recovered with high accuracy, approaching 100% accuracy for some components and yielding good results (90%) even when the binaries emitted by different components appear to be very similar.
Role of Stent Grafts for the Treatment of Failing Hemodialysis Accesses

Covered stents or stent grafts are exciting new products with multiple applications for patients with vascular disease, including hemodialysis access-related complications. Although most of the current uses of stent grafts in these settings are "off-label" (ie, not approved by the US Food and Drug Administration) several studies are currently underway to provide the necessary data to support their application. It is clear that stent grafts provide a rapid, effective means for endovascular repair of ruptured access vessels. The commercially available devices and their current applications for treating access-related complications, including aneurysms/pseudoaneurysms, venous outflow stenoses, cephalic arch lesions, ruptures, and diffuse access stenoses, will be reviewed in this article. Available data are reported along with our current clinical practice and algorithms.
Relative timing of calcite twinning strain and fold-thrust belt development; Hudson Valley fold-thrust belt, New York, U.S.A.

Coarse-grained limestone samples were collected across the Hudson Valley Fold-Thrust Belt with the aim of determining the temporal and spatial relationship between calcite twinning strain and fold-thrust belt development. The majority of the samples have well defined oblate strain ellipsoids with the maximum shortening axes (e3) perpendicular to bedding strike, and e3 magnitudes that range from - 1.5% to 6.5%. Whereas twinning magnitude does not vary systematically through the fold-thrust belt, twinning fabrics fall into two populations based on the presence of outcrop-scale deformational features. Calcite twinning strain preserved in samples from limestone layers absent of any small-scale penetrative deformation, such as cleavage and/or microfaults, are defined as component A strains. Component A strains generally have maximum shortening axes (e3) inclined consistently less than, but in the same E-W direction as, bedding dip. The second population of calcite twinning strain, population B, occurs in limestones pervasively cut by cleavage and/or microfaults. Component B strains has maximum shortening axes (e3) that are horizontal irrespective of bedding dip. Strain population A initiated as a pre- folding, layer-parallel shortening strain that was subsequently modified to its present orientation by active grain- scale rotation during flexural folding. Strain population B reflects post-folding superimposed homogeneous strain, and is restricted to limestone samples with relatively high clay content. 0 1998 Elsevier Science Ltd.
Versatility of the Angularis Oris Axial Pattern Flap for Facial Reconstruction.

Objective To describe the versatility of the axial pattern flap based on the cutaneous perforating branch of the angularis oris artery for reconstruction of large facial defects in dogs, including complications and clinical outcomes. Study Design Retrospective clinical case series. Animals Client-owned dogs (n = 8). Methods Facial flaps (n = 9) based at the commissure of the lip with a caudodorsal orientation were utilized, with established anatomical borders. Flaps were elevated deep to the panniculus carnosus in a caudal to rostral direction, preserving the angularis oris artery, its cutaneous perforator, and surrounding cutaneous vasculature. Flaps were rotated dorsally or ventrally to cover the defect. Primary closure of the donor site was by direct apposition in all cases. Results Angularis oris axial pattern flaps were most commonly used to close large defects of the nasomaxillary area rostral to the eyes (6 dogs), followed by orbital (2) and intermandibular (1) defects. Defects occurred because of tumor resection (6 dogs), trauma (2), and a chronic, non-healing wounding (1). All flaps healed with acceptable functional and cosmetic outcomes without major complications. Followup ranged from 10 days to 16 months. Minor postoperative complications included flap edema (8 dogs), partial incisional dehiscence (3), distal tip necrosis (2), and oroantral fistula recurrence (1). Conclusion Angularis oris axial pattern flaps provided hirsute, full-thickness skin coverage of a variety of large facial defects with minor complications, and should be considered when restructuring large defects of the rostral face or chin.
Structural Default Modeling: A Lattice-Based Approach

That the stockholders’ right to default on corporate debt is an option has been understood since Merton’s seminal 1974 article. Later work by Geske and others applied Merton’s insight to more complex, and more realistic, capital structures and default criteria. Unfortunately, while it is not too hard to write down valuation equations for a firm with multiple classes of risky debt, the equations typically involve high-order multivariate normal distributions, which are quite difficult to evaluate computationally. In this article, Jabbour, Kramin, and Young propose a lattice model in which the default risk in complex capital structures becomes easier to deal with. One key to their approach is to build survival probabilities directly into the tree.