cssi/SciSciGPT-SciSciNet huggingface dataset:
Meniscus transplantation

Understanding the structure and function of the meniscus is critical to understanding its role in overall knee joint function. Injury to, or removal of, meniscal tissue may be associated with articular cartilage wear, knee instability, and, ultimately, the progression of osteoarthritis. While every effort is made for preserving and/or repairing damaged meniscal tissue, in some cases, the meniscus is not amenable to repair after injury. For appropriately indicated patients with symptomatic meniscal deficiency, meniscus allograft transplantation is an excellent surgical solution aimed at reducing pain and improving function. Indications for meniscus allograft transplantation are limited, and concomitant procedures such as osteotomy for malalignment, ligamentous, and/or articular cartilage restoration may be necessary in order to ensure an optimal result following meniscus allograft transplantation. Surgical techniques for meniscus allograft transplantation are variable and include soft-tissue fixation versus bone plug fixation versus bone bridge fixation. Outcomes following meniscus allograft transplantation are generally good to excellent, though reoperation rates are relatively high. The purpose of this article is to provide a concise review of recently published data on meniscus allograft transplantation, with a focus on recent outcomes studies.
Debris: Distributed Element Beamformer Radar for Ice and Subsurface Sounding

The innovations in high-performance, low-power electronics and low-cost space access are unlocking affordable distributed radar systems and new remote sensing opportunities. The Distributed Element Beamformer Radar for Ice and Subsurface sounding (DEBRIS) is a concept to implement a 2D sparse radar aperture to improve the radar's spatial resolution and sounding investigation depth through the reduction of surface clutter. Here, we introduce this system and highlight its applications, orbital configurations, and the implementation considerations to achieve state-of-the-art performance for spaceborne radar sounders.
Modeling Clustered Survival Times of Loblolly Pine with Time-dependent Covariates and Shared Frailties

Tree mortality is an important component of forest tree and stand growth models, which provide decision support for forest managers. Mortality patterns, however, are highly variable and difficult to describe. Despite numerous investigations aimed at developing tree survival models, there are still important gaps that need to be filled. This paper used a large-scale repeated measure dataset collected from permanent sample plots established in 1980/81 across the natural range of loblolly pine (Pinus taeda L.) in the Piedmont, Atlantic Coastal Plain and Gulf Coastal Plain physiographic regions of the US. The primary objective of this study was to explain the survival of loblolly pine trees using time-varying covariates such as diameter at breast height, total tree height, crown ratio, stand age, stand basal area, and dominant height. In this paper, individual-tree mortality was described using a semiparametric proportional hazards regression model. Shared frailty models were used to account for unobserved heterogeneity not explained by the observed covariates. Our investigation involved developing a modeling comparison procedure, predicting mortality based on a frailty model, and quantifying the predictive ability for tree mortality. The survival model developed using a large scale database provides further understanding of mortality trends in planted stands of loblolly pine. The survival model will enable forest managers to more accurately specify initial planting density, thinning schedules, and other management interventions.
Hierarchy Theory, Ecological

Hierarchy theory is a dialect of general systems theory, and as such is particularly concerned with the role of the observer in choosing criteria for prescribing or describing levels. In simple ecosystems there is an accepted set of values. In complex systems, the very structure changes as new levels emerge and the system invites the observer to assess the situation at any of a large number of levels. In the face of complexity, the myth of the objective observer fails because structure can melt into process, meaning can disappear, and qualitative distinctions change into quantifiable matters of degree. These fundamental changes come about as the complex system matures, decays, or reorganizes, or as the observer shifts her level of analysis. Even when the change has a material basis, the observer is still responsible for deciding difference. How much difference must there be before the system is estimated to be unstable or a new structure is recognized? Thus hierarchy theory focuses on the observer's decisions, which makes it particularly adept at dealing with complex systems. Keywords: ecosystem; ordered set; spatio-temporal scaling; PCA; food chains
Asymptomatic celiac and superior mesenteric artery stenoses are more prevalent among patients with unsuspected renal artery stenoses

The prevalence of unsuspected renal artery stenosis among patients with peripheral vascular disease has been reported to be as high as 40%, but the prevalence of asymptomatic celiac and superior mesenteric artery stenoses in these patients is not known. The biplane aortograms of 205 male patients who were military veterans and had aneurysms or occlusive disease were independently reviewed, and medical records were studied to determine associated coronary disease, risk factors, and patient outcome. Fifty-six patients (27%) had a 50% or greater stenosis in the celiac or superior mesenteric artery, and seven patients (3.4%) had significant stenoses in both mesenteric arteries. Patients with celiac or superior mesenteric artery stenoses were older (p = 0.002) and had a higher prevalence of hypertension (p = 0.029) than those without significant mesenteric stenoses. Fifty of the 205 patients had significant renal artery stenoses, and 20 had advanced (greater than 75% diameter loss) renal stenoses. Ten of the 20 patients (50%) with advanced renal stenoses had a concomitant celiac artery stenosis, compared to 40 of the 185 patients (22%) who did not have advanced renal stenoses (p = 0.011). In the present study asymptomatic celiac or superior mesenteric artery stenoses were common among male veterans evaluated for peripheral vascular disease, but the prevalence of significant stenoses in both the celiac and superior mesenteric arteries was low. The prevalence of significant celiac stenosis was higher in patients with advanced (greater than 75%) renal artery stenoses who might be considered for prophylactic renal revascularization. Lateral aortography with evaluation of the celiac artery is always appropriate in these patients.
Test of gauge invariance: Charged harmonic oscillator in an electromagnetic field

Abstract The equation for a charged harmonic oscillator in an electromagnetic field is solved in the electric dipole approximation. The probability of finding the oscillator in the ground state is calculated in the conventional way and in a gauge-invariant way, and the results compared.
How often may a read rebreathing test be repeated

Summary. The minimum duration of the rest period between repeated Read re-breathing tests required to prevent interference between tests is yet unknown. Four male and four female volunteers performed eight Read rebreathing CO2 response tests in a period of 2·5 h. The test-to-test interval was as short as 10 min. No major differences in slope or intercept were found according to time in either the group as a whole or as male and female groups taken separately. There was a slight but nonsignificant depression in slope for the 3rd to 5th tests. The females responded less to a CO2 challenge than did the males. It is concluded that a test-to-test interval as short as 10 min does not effect the results of the Read rebreathing test.
Submerged reflectance measurements as a function of visible wavelength

Submerged spectral reflectance measurements made on paint samples using two different techniques are compared. With the first technique spectral measurements are made with a simple thin water film measurement technique originally used for photopic viewing. A comparison of these measurements with a second technique in which the measured sample is immersed in water in a cylindrical container and the submerged reflectance is measured with a goniophotometer shows good agreement for wavelengths from 420 to 700 nm.
A stabilized finite element method for the Stokes problem based on polynomial pressure projections

A new stabilized finite element method for the Stokes problem is presented. The method is obtained by modification of the mixed variational equation by using local L2 polynomial pressure projections. Our stabilization approach is motivated by the inherent inconsistency of equal-order approximations for the Stokes equations, which leads to an unstable mixed finite element method. Application of pressure projections in conjunction with minimization of the pressure–velocity mismatch eliminates this inconsistency and leads to a stable variational formulation. Unlike other stabilization methods, the present approach does not require specification of a stabilization parameter or calculation of higher-order derivatives, and always leads to a symmetric linear system. The new method can be implemented at the element level and for affine families of finite elements on simplicial grids it reduces to a simple modification of the weak continuity equation. Numerical results are presented for a variety of equal-order continuous velocity and pressure elements in two and three dimensions. Copyright © 2004 John Wiley & Sons, Ltd.
Patient-selected goals: the fourth dimension in assessment of pelvic floor disorders

The purpose of the study was to assess the relationship between self-expressed urogynecologic goals, symptoms, and treatment choice. Charts of women presenting for urogynecology consultation were reviewed. Demographics, diagnoses and responses to the pelvic floor distress inventory and medical, social, and epidemiologic aspects of aging questionnaires were recorded. Patients listed urogynecology goals before consultation. We categorized goals into five categories and then compared these categories by symptom type, severity, and treatment. Three hundred five women reported 635 goals (median 2, range 1–6). The number of goals listed per patient did not differ by age, race, comorbidities, or clinical diagnosis (p > 0.05). The most frequent goal category was symptoms (67%), followed by information seeking (12%), lifestyle (11%), emotional (4%), and “other” (6%). Women selecting non-surgical treatment were more likely to list information seeking as primary goal than those who chose surgery (p = 0.009). One third of participants expressed a primary non-symptom goal and were more likely to seek non-surgical therapy.
The nation with the soul of a church

The apt phrase, “a nation with the soul of a church” was coined by G. K. Chesterton in answer to his question, “What Is America?” the title of the autobiographical essay in which he relates how he came to appreciate what the United States was all about. Being irked, and then amused by the kinds of questions asked him when he applied for entrance into the United States, he was led to ask what is it that “makes America peculiar?” He concluded that it was the fact thatAmerica is the only nation in the world that is founded on a creed. That creed is set forth with dogmatic and even theological lucidity in The Declaration of Independence… It enunciates that all men are equal in their claim to justice, and that governments exist to give them that justice, and that their authority is for that reason just. It certainly does condemn anarchism, and it does also by inference condemn atheism, since it clearly names the Creator as the ultimate authority from whom these equal rights are derived.
Transient analysis of electrically small antennas

The transient properties of electrically small antennas are studied and a comprehensive investigation on the time-domain behavior of resonant-type antennas is presented. Without loss of generality, damping factor and Q factor associated with the fundamental mode for different PIFA designs are compared to those of an equivalent RLC resonator and it is shown that for Q>>1, time-domain characteristics of the fundamental radiated mode is very well matched to that of a high-Q resonator.
Medium Throughput pK a Determinations of Drugs and Chemicals by Reverse Phase HPLC with an Organic Gradient

Abstract A semi‐automated method to determine pK a values of drugs and chemicals by reverse phase HPLC is described. The method uses the capabilities of a crosslinked reverse phase HPLC column (Agilent extend C‐18) as a separation device. The pK a value was determined based on the different retention behaviors of the charged, multiply charged, and uncharged species at different pH conditions. The advantages of this method are low sample consumption, suitability for less soluble compounds, high purity samples not necessary, no spectral shift needed, high sample throughput, easy set up, high sensitivity, low cost, good precision, and agreement with literature values.
Amphetamine sensitivity in open-field activity vs. the prepulse inhibition paradigm

Abstract Amphetamine-induced mesolimbic dopamine release has been reported to reduce prepulse inhibition of the acoustic startle response. In addition, it is well known that mesolimbic dopamine stimulation leads to hyperactivity. The present study was undertaken to explore the possibility that one or the other measure may be a more sensitive in vivo indicator of dopamine release in the nucleus accumbens by determining if the amphetamine dose-response curves for these two behavioral measures were different. The data indicate that the dose-response curves obtained for the different behavioral measures are identical. These data are consistent with the idea that the same dopamine terminal field supports both prepulse inhibition of the acoustic startle response and dopamine-stimulated hyperactivity.
Algebraic distance estimations for enriched isogeometric analysis

Abstract In problems with evolving boundaries, interfaces or cracks, blending functions are used to enrich the underlying domain with the known behavior on the enriching entity. The blending functions are typically dependent on the distance from the propagating boundaries. For boundaries defined by free form curves or surfaces, the distance fields have to be constructed numerically. This may require either a polytope approximation to the boundary and/or an iterative solution to determine the exact distance to the boundary. In this paper a purely algebraic, and computationally efficient technique is described for constructing distance measures from Non-Uniform Rational B-Splines (NURBS) boundaries that retain the geometric exactness of the boundaries while eliminating the need for iterative and non-robust distance calculation. The constructed distance measures are level sets of the implicitized constituent Bezier patches of the NURBS surfaces that are obtained purely algebraically. Since, in general, the implicitized functions extend beyond the parametric range of the generating Bezier patch, algorithmic procedures are developed to trim these global implicit functions to the boundaries of the Bezier patch. Boolean compositions are then carried out between adjoining Bezier patches to construct a composite distance field over the domain. The compositions rely on R-functions that are also algebraic in nature. The developed technique is demonstrated by constructing algebraic distance field for complex geometries and by solving a variety of examples culminating in the analysis of steady state heat conduction in a solid with arbitrary shaped three-dimensional cracks.
Hyperfine interaction and chemical bonding in the PdH molecule

Abstract The ESR spectra of PdH and PdD molecules in the 2 Σ + ground state have been observed while trapped in argon (and krypton) matrices at 4°K. The hyperfine coupling tensor components relative to both 105 Pd and H or D nuclei were determined and g tensor components found to be g ‖ = 1.965, g ⊥ = 2.293. Analysis of these data indicate that the ground-state configuration of PdH is KLMN sp (4 dδ ) 4 (4 dπ ) 4 (5 sσ ) 2 (4 dσ ) and that an excited 2 Π i state of configuration ⋯(4 dπ ) 3 (5 σs ) 2 (4 dσ ) 2 lies about 20,000 cm −1 above the X 2 Σ. The value of g ⊥ is in accord with this and also in accord with the observed large negative value of γ 0 , the spin-doubling constant in the ground state. The spin density on H is small (probably
Adverse pregnancy and birth outcomes associated with underlying diagnosis with and without assisted reproductive technology treatment

Objective To compare the risks for adverse pregnancy and birth outcomes by diagnoses with and without assisted reproductive technology (ART) treatment to non-ART pregnancies in fertile women. Design Historical cohort of Massachusetts vital records linked to ART clinic data from Society for Assisted Reproductive Technology Clinic Outcome Reporting System. Setting Not applicable. Patient(s) Diagnoses included male factor (ART only), endometriosis, ovulation disorders, tubal (ART only), and reproductive inflammatory disorders (non-ART only). Pregnancies resulting in singleton and twin live births from 2004 to 2008 were linked to hospital discharges in women who had ART treatment (n = 3,689), women with no ART treatment in the current pregnancy (n = 4,098), and non-ART pregnancies in fertile women (n = 297,987). Intervention(s) None. Main Outcome Measure(s) Risks of gestational diabetes, prenatal hospitalizations, prematurity, low birth weight, and small for gestational age were modeled using multivariate logistic regression with fertile deliveries as the reference group adjusted for maternal age, race/ethnicity, education, chronic hypertension, diabetes mellitus, and plurality (adjusted odds ratios [AORs] and 95% confidence intervals [CIs]). Result(s) Risk of prenatal hospital admissions was increased for endometriosis (ART: 1.97, 1.38–2.80; non-ART: 3.34, 2.59–4.31), ovulation disorders (ART: 2.31, 1.81–2.96; non-ART: 2.56, 2.05–3.21), tubal factor (ART: 1.51, 1.14–2.01), and reproductive inflammation (non-ART: 2.79, 2.47–3.15). Gestational diabetes was increased for women with ovulation disorders (ART: 2.17, 1.72–2.73; non-ART: 1.94, 1.52–2.48). Preterm delivery (AORs, 1.24–1.93) and low birth weight (AORs, 1.27–1.60) were increased in all groups except in endometriosis with ART. Conclusion(s) The findings indicate substantial excess perinatal morbidities associated with underlying infertility-related diagnoses in both ART-treated and non-ART-treated women.
On condensation oscillations

Abstract Condensation oscillations in showers and thunderstorms are represented by variations in the vertical air currents that are induced by the accumulation and fallout of condensed water. A simple analytic theory of condensation oscillations and calculations on more complete numerical models indicate that their period is approximately proportional to the inverse square root of the condensation function, i.e. the amount of condensate produced per unit rise of saturated air, and that the period is independent of the magnitude of thermal buoyancy.
Experience with phenylindanedione in the management of acute myocardial infarction.

Abstract A series of 251 cases of acute myocardial infarction treated during the acute phase with phenylindanedione is reported. All cases treated for less than 48 hours are excluded. The over-all recovery rate was 90 per cent. The incidence of thromboembolic complications was 3.5 per cent. Major hemorrhagic complications occurred in only 1.6 per cent of the total cases. Two cases of skin eruption requiring the immediate discontinuation of the drug were observed. It is our belief that, at present, this is the oral anticoagulant of choice.
Planning the coordination of ground transport

Proper coordination in the design of a transportation system requires consideration of general land use in the area served, and indeed of the entire sociological and ecological fabric of society. Moreover, the designer must help weave this fabric while it is being used. A possible starting place for a transportation study, and some would argue the only starting place, is an overall regional plan. More and more it is being clearly recognized that a transportation link not only satisfies established needs in a region but also develops and anticipates others.
Improved murine glioma detection following modified diet and photobleaching of skin PpIX fluorescence

The Aminolevulinic Acid (ALA) - Protoporphyrin IX (PpIX) system is unique in the world of photosensitizers in that the prodrug ALA is enzymatically transformed via the tissue of interest into fluorescently detectable levels of PpIX. This system can be used to monitor cellular metabolism of tumor tissue for applications such as therapy monitoring. Detecting PpIX fluorescence noninvasively has proven difficult due to the high levels of PpIX produced in the skin compared to other tissue both with and without ALA administration. In the current study, methods to decrease skin PpIX autofluorescence and skin PpIX fluorescence following ALA administration have been examined. Use of a purified diet is found to decrease both skin PpIX autofluorescence and skin PpIX fluorescence following ALA administration, while addition of a broad spectrum antibiotic to the water shows little effect. Following ALA administration, improved brain tumor detection is seen when skin PpIX fluorescence is photobleached via blue light prior to transmission spectroscopic measurements of tumor bearing and control animals. Both of these methods to decrease skin PpIX autofluorescence and skin PpIX fluorescence following ALA administration are shown to have a large effect on the ability to detect tumor tissue PpIX fluorescence noninvasively in vivo .
Conduction mechanism in boron carbide

Electrical conductivity, Seebeck-coefficient, and Hall-effect measurements have been made on single-phase boron carbides, B(1-x)C(x), in the compositional range from 0.1 to 0.2 X, and between room temperature and 1273 K. The results indicate that the predominant conduction mechanism is small-polaron hopping between carbon atoms at geometrically inequivalent sites.
Effects of sky brightness distribution upon penetration of diffuse radiation through canopy gaps in a deciduous forest

Abstract The penetration of diffuse sky radiation via canopy opening into a fully-leafed tulip poplar forest was estimated from canopy structure data obtained from canopy photographs and from sky brightness distribution approximations, using techniques originally developed by Anderson (1964). Small differences were found among mean daily penetration fractions predicted assuming an isotropic sky (UOC), a standard overcast sky (SOC), or an approximation of the weighted daily average predicted using a clear sky brightness distribution. For shorter time periods, penetration of diffuse radiation estimated using the UOC and SOC approximations differed substantially from estimates made using the clear-sky brightness distribution. Most diffuse radiation passes through openings that are within 10 degrees of the solar disk. Hence the directional distribution of diffuse radiation in the forest is strongly controlled by solar position on clear to partly cloudy days. Amounts of diffuse radiation observed in the forest under clear skies agree fairly well with those predicted by the model developved by Reifsnyder et al. (1971). In both cases, penetration increases with increasing solar elevation on clear days. We conclude that the SOC assumption produces acceptable results for time periods of a day or longer, but for shorter times with clear skies the use of the clear sky brightness distribution is necessary for most simulation or prediction modelling.
The Information Content of Method of Payment in Mergers: Evidence from Real Estate Investment Trusts (REITs)

We provide evidence on the information content of the method of payment in mergers by examining shareholder returns in a sample of REIT mergers over the period 1994–1998. When the target firm is publicly held, we find that transactions are always stock-financed, and that acquiring firm shareholders sustain small negative returns around the announcement date. When the target is privately held, cash financing, mixed (stock and cash) financing, and placement of blocks of acquirer stock with target owners are more prevalent. Acquirer returns are positive in stock-financed mergers when the target is private, which is consistent with both the information signaling and monitoring by blockholders hypotheses. Further analysis supports the information signaling hypothesis as the dominant explanation. The effects of other explanatory variables are similar whether the target is public or private. Most significantly, acquiring shareholder returns are negatively related to the acquirer's size, but positively related to the acquirer's use of the UPREIT organizational structure. The positive wealth effects of the UPREIT structure are not fully explained as the capitalization of tax benefits.
Visualizing chromatin dynamics in intact cells

Chromatin and associated regulatory proteins regulate gene expression in the natural environment of the intact cell nucleus. Specific combinations of DNA-binding transcription factors and recruited coregulatory proteins alter the conformation of chromatin at promoters and enhancers of target genes to stimulate or repress transcription. The dynamic nature of the regulatory proteins active in these processes allows the cell to modulate gene expression very rapidly, an important feature in many physiological processes. Live cell imaging and photobleaching studies of fluorescently-tagged proteins reveal that many transcription factors and other chromatin-associated proteins rapidly move through the nucleoplasm. Transcription factors also transiently interact with specific regulatory sequences in chromatin, suggesting that gene activation does not require the formation of stable long-lived regulatory complexes on the chromatin. In this review we discuss how dynamic interactions allow transcriptional regulatory proteins find their targets within the nucleus, alter target chromatin structure, and modulate physiological gene expression.
Snowpack monitoring in North America and Eurasia using passive microwave satellite data

Areas of the Canadian high plains, the Montana and North Dakota high plains, and the steppes of central Russia have been studied in an effort to determine the utility of spaceborne microwave radiometers for monitoring snow depths in different geographic areas. Significant regression relationships between snow depth and microwave brightness temperatures were developed for each of these homogeneous areas. In each of the study areas investigated in this paper, Nimbus-6 (0.81 cm) ESMR data produced higher correlations than Nimbus-5 (1.55 cm) ESMR data in relating microwave brightness temperature to snow depth. It is difficult to extrapolate relationships between microwave brightness temperature and snow depth from one area to another because different geographic areas are likely to have different snowpack conditions.
Developing acceleration schedules for NDCX-II

The Virtual National Laboratory for Heavy-Ion Fusion Science is developing a physics design for NDCX-II, an experiment to study warm dense matter heated by ions near the Bragg-peak energy. Present plans call for using about thirty induction cells to accelerate 30 nC of Li+ ions to more than 3 MeV, followed by neutralized drift-compression. To heat targets to useful temperatures, the beam must be compressed to a millimeter-scale radius and a duration of about 1 ns. An interactive 1-D particle-in-cell simulation with an electrostatic field solver, acceleration-gap fringe fields, and a library of realizable analytic waveforms has been used for developing NDCX-II acceleration schedules. Axisymmetric simulations with WARP have validated this 1-D model and have been used both to design transverse focusing and to compensate for injection non-uniformities and radial variation of the fields. Highlights of this work are presented here.
Stress-induced cell-cycle activation in Tip60 haploinsufficient adult cardiomyocytes.

Background Tat-interactive protein 60 (Tip60) is a member of the MYST family of histone acetyltransferases. Studies using cultured cells have shown that Tip60 has various functions including DNA repair, apoptosis and cell-cycle regulation. We globally ablated the Tip60 gene (Htatip), observing that Tip60-null embryos die at the blastocyst stage (Hu et al. Dev.Dyn.238:2912;2009). Although adult heterozygous (Tip60(+/-)) mice reproduce normally without a haploinsufficient phenotype, stress caused by Myc over-expression induced B-cell lymphoma in Tip60(+/-) adults, suggesting that Tip60 is a tumor suppressor (Gorrini et al. Nature 448:1063;2007). These findings prompted assessment of whether Tip60, alternative splicing of which generates two predominant isoforms termed Tip60α and Tip60β, functions to suppress the cell-cycle in adult cardiomyocytes. Methodology/principal findings Western blotting revealed that Tip60α is the predominant Tip60 isoprotein in the embryonic heart, transitioning at neonatal stages to Tip60β, which is the only isoprotein in the adult heart wherein it is highly enriched. Over-expression of Tip60β, but not Tip60α, inhibited cell proliferation in NIH3T3 cells; and, Tip60-haploinsufficient cultured neonatal cardiomyocytes exhibited increased cell-cycle activity. To address whether Tip60β suppresses the cardiomyocyte cell-cycle in the adult heart, hypertrophic stress was induced in Tip60(+/+) and Tip(+/-) littermates via two methods, Myc over-expression and aortic banding. Based on immunostaining cell-cycle markers and western blotting cyclin D, stress increased cardiomyocyte cell-cycle mobilization in Tip60(+/-) hearts, in comparison with Tip60(+/+) littermates. Aortic-banded Tip60(+/-) hearts also exhibited significantly decreased apoptosis. Conclusions/significance These findings provide evidence that Tip60 may function in a tumor suppressor pathway(s) to maintain adult cardiomyocytes in replicative senescence.
Size‐selective comparison of fetal calvarial versus adult marrow osteogenic colony‐forming entities

Background: This experiment was designed to test whether a single cell suspension of adult marrow-derived cells will form mineralized bone nodules in vitro. Methods: At the time of plating, cellular dispersions of either young adult rabbit bone marrow cells or, as controls, of fetal mouse calvarial cells were size-selected by sieving through various poresize plastic meshes. Results: When marrow-derived cells were passed through a 105 μm pore-size mesh, fibroblastic cell cultures grew in vitro in six of six attempts; however, marrow cell clusters backwashed off 105 μm pore-size meshes produced osteogenic colonies in vitro in six of six trials. Fetal calvarial cells filtered through a 30 μm pore-size mesh yielded osteogenic nodules in culture in six of six tests. Conclusions: For adult bone marrow, cell clumps or clusters larger than 105 μm produced bone colonies under standard cell culture conditions, whereas for fetal calvarial cells, the initiating agent was smaller than 30 μm. © 1994 Wiley-Liss, Inc.
Effect of inhibition of nitric oxide formation on coronary blood flow during exercise in the dog

Objective: The aim was to test the hypothesis that nitric oxide (or a related compound) contributes to the coronary vasodilatation during physiological increases of myocardial O2 consumption that occur with exercise. Methods: Active hyperaemia associated with graded treadmill exercise and coronary reactive hyperaemia were examined in chronically instrumented awake dogs during control conditions and after administration of the nitric oxide synthase inhibitor, N-nitro-L-arginine (LNNA). Results: LNNA blunted the response to intracoronary acetylcholine, with an 80(SEM 6)% decrease in the maximum acetylcholine induced coronary vasodilatation, but did not alter the response to sodium nitroprusside. Increases of myocardial oxygen requirements during treadmill exercise were associated with progressive increases of coronary blood flow. LNNA caused a significant increase in arterial pressure at rest and during exercise, and this was associated with slightly but significantly higher myocardial oxygen consumption. Coronary blood flow during exercise was also slightly higher after LNNA, while coronary vascular resistance was unchanged. Coronary sinus Po2 was slightly but significantly lower during exercise after LNNA, indicating that coronary vasodilatation in response to the increased myocardial oxygen demands during exercise was slightly blunted by LNNA. LNNA did not alter the peak increase in blood flow during reactive hyperaemia following a 15 s coronary occlusion, but decreased the duration of the response and decreased reactive hyperaemia debt repayment from 300(56)% during control conditions to 182(36)% after LNNA (p<0.01). Conclusions: LNNA antagonised coronary vasodilatation in response to acetylcholine and blunted coronary reactive hyperaemia, but did not substantially impair the coronary vasodilatation associated with increased myocardial oxygen requirements produced by exercise. These findings fail to support an essential role for nitric oxide in coronary resistance vessel dilatation during exercise in the dog. Cardiovascular Research 1994; 28 :119-124
Instructional designers as reflective practitioners: developing professional identity through reflection

As the design thinking approach becomes more established in the instructional design (ID) discourse, the field will have to reconsider the professional identity of instructional designers. Rather than passively following models or processes, a professional identity rooted in design thinking calls for instructional designers to be dynamic agents of change who use reflective thinking to navigate the design space and develop solutions to ill-structured problems. Graduate programs in ID will also need to prepare students to manage the complexities they will encounter in their professional practice, including the establishment of design precedents, reflective thinking skills, and the foundations of professional identity. This research explored the use of reflective writing assignments in an introductory ID graduate course, with results indicating that most students are able to engage in meaningful reflection in relation to prompts concerning design concepts, experiences, and identity attributes, although no clear patterns of improvement emerged over time. Future directions for research include the use of feedback and the structure of prompts (including frequency of writing assignments and wording of prompts) to support improved student performance.
Characterizing electroactive polymers for use in robotic surgical instruments

The popularity of minimally invasive surgical procedures over traditional open procedures motivates us to develop new instruments that address the limits of existing technology and enable more widespread use of minimally invasive approaches. Robotic surgical instruments have the potential to provide improved dexterity and range of motion within the confines of the human body when compared with manually actuated instruments. The high strain response and elastic energy density of electron-irradiated P(VDF-TrFE) make it a candidate actuator material for robotic instruments that provide electronic mediation and multiple degrees of freedom of tip movement. We are currently studying both active and passive properties of P(VDF-TrFE) with the goal of constructing a mathematical model of the material's behavior. Studies have been conducted on 15 micron thick film samples in rolled and rolled-flattened configurations. Passive properties can be represented by a 5 parameter viscoelastic model with two time constants on the order of ten and 200 seconds. Active responses were found to have strong dependence upon field and modest dependence upon load. We suggest means by which the active and passive responses can be combined in a model of steady-state response that would be of value in positioning tasks. The time course of the active response appears to contain components on two time scales, but further studies are required to characterized it in more detail.
Numerical solutions of the three-dimensional magnetohydrodynamic α model

We present direct numerical simulations and $\ensuremath{\alpha}$-model simulations of four familiar three-dimensional magnetohydrodynamic (MHD) turbulence effects: selective decay, dynamic alignment, inverse cascade of magnetic helicity, and the helical dynamo effect. The MHD $\ensuremath{\alpha}$ model is shown to capture the long-wavelength spectra in all these problems, allowing for a significant reduction of computer time and memory at the same kinetic and magnetic Reynolds numbers. In the helical dynamo, not only does the $\ensuremath{\alpha}$ model correctly reproduce the growth rate of magnetic energy during the kinematic regime, it also captures the nonlinear saturation level and the late generation of a large scale magnetic field by the helical turbulence.
Adenocarcinomain Situof the Uterine Cervix: Management and Outcome

Abstract Objective: To retrospectively review the management of adenocarcinoma in situ of the uterine cervix, to determine the outcome of conization versus hysterectomy, and to compare the results achieved by different methods of conization. Methods: We performed a retrospective pathology and chart review of 46 patients with cervical adenocarcinoma in situ from January 1980 to October 1994. Results: Nine patients were managed during the first half of the study period and 37 were managed in the second half. The mean age of patients was 38.4 years (range 25–72). Forty-five of 46 patients were diagnosed as a result of an abnormal Pap smear, although only 19 smears indicated adenocarcinoma in situ or other glandular abnormalities. Cold knife conization resulted in a 33% rate of positive margins for adenocarcinoma in situ compared to 50% for large loop excision of the transformation zone (LLETZ). Among 24 conservatively managed patients with negative conization margins, there have been 2 (8.3%) recurrences of adenocarcinoma in situ. Among patients not undergoing hysterectomy as definitive treatment, 1 of 18 (6%) patients undergoing cold knife conization recurred, compared to 4 of 14 (29%) managed with LLETZ, despite a 63.4-month shorter mean follow-up interval for the LLETZ patients. Conclusions: Cold knife conization is associated with a lower rate of recurrence of cervical adenocarcinoma in situ compared to LLETZ. We recommend cold knife conization for patients who are not treated with hysterectomy.
Neuregulin-1 proteins in rat brain and transfected cells are localized to lipid rafts

Neuregulin-1 proteins and their receptors, which are members of the ErbB subfamily of receptor tyrosine kinases, play essential roles in the development of the nervous system and heart. Most neuregulin-1 isoforms are synthesized as transmembrane proproteins that are proteolytically processed to yield an N-terminal fragment containing the bioactive EGF-like domain. In this study we investigated whether neuregulins are found in lipid rafts, membrane microdomains hypothesized to have important roles in signal transduction, protein trafficking, and proteolytic processing. We found that 45% of a 140-kDa neuregulin protein in rat brain synaptosomal plasma membrane fractions was insoluble in 1% Triton X-100. Flotation gradient analysis demonstrated the presence of the brain 140 kDa neuregulin protein in low-density fractions enriched in PSD-95, a known lipid raft protein. In transfected cells expressing the neuregulin I-beta 1a or the III-beta 1a isoform, most of the neuregulin proprotein was insoluble in 1% Triton X-100, and neuregulin proproteins and C-terminal fragments were detected in lipid raft fractions. In contrast, the III-beta 1a N-terminal fragment was detected only in the detergent-soluble fraction. These results suggest that localization of neuregulins to lipid rafts may play a role in neuregulin signaling within the nervous system.
The differential approximation for radiative transfer in an emitting, absorbing and anisotropically scattering medium

Abstract The validity of the well-established differential approximation in radiative transfer is extended to include linear-anisotropic scattering. Sample results demonstrate the accuracy of the method.
The spectrum of CFTR-related disease

There is increasing appreciation for the presence of diseases which do not fit the criteria for classic cystic fibrosis but are caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR). This case describes a patient with documented CFTR dysfunction by nasal potential difference measurement who presents with chronic idiopathic pancreatitis, sinusitis, and allergic bronchopulmonary aspergillosis (ABPA), but not congenital bilateral absence of the vas deferens (CBAVD) or other classic symptoms of cystic fibrosis. This rare case demonstrates both the spectrum of disease which can be seen with CFTR dysfunction and the steps required to document CFTR involvement.
The effect of SRIF on the EEG sleep of normal men.

Abstract The aim of this investigation was to evaluate EEG sleep, especially measures of delta-wave sleep, during and after the administration of somatostatin (SRIF). Eleven normal men, ages 22–37 yr, were administered saline or SRIF (0.1 μg/kg/min IV) over 160 min at bedtime. SRIF delayed sleep-related growth hormone (GH) secretion without altering the amount of GH available during the entire night of sleep. No changes in delta-wave sleep occurred during either the first 100 min of sleep or the remainder of the night. Furthermore, all major EEG sleep variables were not significantly different between the saline and SRIF infusion night. It would not appear that the peripheral administration of this dose of SRIF or the subsequent delay of GH release has quantitative effects on EEG measures of all-night sleep.
Cytological differentiation of the mesothelial cells of the yolk sac of the bat, Tadarida brasiliensis cynocephala

An ultrastructural analysis of the mesothelial cells of the yolk sac of the bat throughout gestation is presented. At first these cells are closely associated with the cytotrophoblast but become displaced by action of the allan-tois and collapse of the yolk sac. The mesothelial cells are exposed to the exo-coelom and develop cytological features characteristic of absorptive cells. Among these features are: (1) long microvilli extending from the apical and lateral plasma membranes and (2) absorptive canaliculi and tubules as well as absorptive vacuoles in the superficial cytoplasm. There is a paucity of mitochondria and rough endoplasmic reticulum throughout the existence of this cell type. After midgestation, granules containing numerous crystalloids appear in the cytoplasm of most of the cells. These are apparently the result of the absorption of protein-aceous material from the exocoelom. The crystalloids disappear before birth, and the mesothelium becomes degenerative in appearance. This sequence of development of the cytological features suggests a dynamic role for the mesothelium throughout its existence that involves absorption and storage of proteinaceous material from the exocoelom for use by the embryo.
B‐Cell Abnormalities in AIDS: Stable and Clonally‐Restricted Antibody Response in HIV‐1 Infection

Antibodies in sera of HIV-1 infected individuals against the HIV-1 core protein (p24), HIV-1 envelope glycoprotein (gp120) and reverse transcriptase (RT) are characterized by a skewed light chain isotype expression. The kappa/lambda ratios of antibodies to p24 and gp120 in infected individuals were found to be unique in each individual, but constant over several years independently from disease progression. The oligoclonal nature of the anti-HIV-1 antibodies suggested by skewed kappa/lambda expression was confirmed with isoelectric focusing of affinity purified antibodies to p24 and gp120. Analysis of the utilization of V gene families in purified anti-p24 and anti-gp120 antibodies revealed a restricted and biased VH gene family usage. In contrast, the utilization of VK gene families appeared to be random. The finding of stable and restricted antibody responses in infected individuals could be one of the causes for the failure to produce antibodies to HIV-1 that are effective against escape virus variants.
Insights into the Development and Evolution of Exaggerated Traits Using De Novo Transcriptomes of Two Species of Horned Scarab Beetles

Scarab beetles exhibit an astonishing variety of rigid exo-skeletal outgrowths, known as “horns”. These traits are often sexually dimorphic and vary dramatically across species in size, shape, location, and allometry with body size. In many species, the horn exhibits disproportionate growth resulting in an exaggerated allometric relationship with body size, as compared to other traits, such as wings, that grow proportionately with body size. Depending on the species, the smallest males either do not produce a horn at all, or they produce a disproportionately small horn for their body size. While the diversity of horn shapes and their behavioural ecology have been reasonably well studied, we know far less about the proximate mechanisms that regulate horn growth. Thus, using 454 pyrosequencing, we generated transcriptome profiles, during horn growth and development, in two different scarab beetle species: the Asian rhinoceros beetle, Trypoxylus dichotomus, and the dung beetle, Onthophagus nigriventris. We obtained over half a million reads for each species that were assembled into over 6,000 and 16,000 contigs respectively. We combined these data with previously published studies to look for signatures of molecular evolution. We found a small subset of genes with horn-biased expression showing evidence for recent positive selection, as is expected with sexual selection on horn size. We also found evidence of relaxed selection present in genes that demonstrated biased expression between horned and horn-less morphs, consistent with the theory of developmental decoupling of phenotypically plastic traits.
IGFBP-3 Inhibits the Proliferation of Neural Progenitor Cells

Insulin like growth factor-1 (IGF-1) plays an important role in the proliferation and differentiation of neural progenitor cells. The effects of IGF-1 can be regulated by insulin like growth factor binding protein-3 (IGFBP-3) which can either inhibit or stimulate the proliferation of cells depending on the expression of proteases that can release IGF-1 from IGF1-IGFBP3 complex. Although IGF-1 is essential for the development of brain, both IGFBP-3 and IGF-1 are elevated in the brains of children younger than 6 months of age. Likewise, IGFBP-3 is also upregulated following cerebral ischemia and hypoxia. However, the role of IGFBP-3 in neurogenesis is not clear. Using an in vitro culture system of rat neural progenitor cells, we demonstrate that IGFBP-3 specifically regulates the IGF-1 mediated neural progenitor cell proliferation via down regulation of phopho-Akt, and cyclin D1. In addition, IGFBP-3 also decreased the content of nestin in the neural progenitor cells indicating its potential role in neurogenesis.
Psychosocial metaphors of physical distress among MS patients

Abstract This paper explores the dynamics between chronic illness and culture and analyzes how a person's expressions of chronic illness are culturally constituted. The analysis focuses on the ways physical symptoms among multiple sclerosis patients are expressed and experienced as psychosocial problems. The process of transforming a biological construct into a social one is discussed. These transformations are explored through the doctor/patient transaction and the solidification of psychosocial problems among MS patients during their interaction with their ‘significant others’ and then transferred to their larger social-cultural sphere.