cssi/SciSciGPT-SciSciNet huggingface dataset:
Racial disparities in the use of outpatient mastectomy.

Abstract Background Racial disparities exist within many domains of cancer care. This study was designed to identify differences in the use of outpatient mastectomy (OM) based on patient race. Methods We identified patients in the American College of Surgeons National Surgical Quality Improvement Program Participant Use File (during the years 2007–2010) who underwent a mastectomy. The association between mastectomy setting, patient race, patient age, American Society of Anesthesiology physical status classification, functional status, mastectomy type, and hospital teaching status was determined using the chi-square test. A multivariable logistic regression analysis was developed to assess the relative odds of undergoing OM by race, with adjustment for potential confounders. Results We identified 47,318 patients enrolled in the American College of Surgeons National Surgical Quality Improvement Program Participant Use File who underwent a mastectomy during the study time frame. More than half (62.6%) of mastectomies were performed in the outpatient setting. All racial minorities had lower rates of OM, with 63.8% of white patients; 59.1% of black patients; 57.4% of Asian, Native Hawaiian, or Pacific Islander patients; and 43.9% of American Indian or Alaska Native patients undergoing OM (P Conclusions Disparities exist in the use of OM among racial minorities. Further studies are needed to identify the role of cultural preferences, physician attitudes, and insurer encouragements that may influence these patterns of use.
Oxygen sensitivity of NMDA receptors: relationship to NR2 subunit composition and hypoxia tolerance of neonatal neurons

Neonatal rats survive and avoid brain injury during periods of anoxia 25 times longer than adults. We hypothesized that oxygen activates and hypoxia suppresses NMDA receptor (NMDAR) responses in neonatal rat neurons, explaining the innate hypoxia tolerance of these cells. In CA1 neurons isolated from neonatal rat hippocampus (mean postnatal age [P] 5.8 days), hypoxia (PO(2) 10 mm Hg) reduced NMDA receptor-channel open-time percentage and NMDA-induced increase in [Ca(2+)](i) (NMDA DeltaCa(2+)) by 38 and 68% (P<0.01), respectively. In P20 neurons the reductions were not significant. In P3-10 CA1 neurons within intact hippocampal slices, hypoxia reduced NMDA DeltaCa(2+) by 52% (P=0.002) and decreased NMDA-induced death by 45% (P=0.004). Phalloidin, a microtubule stabilizer, prevented hypoxia-induced inhibition of NMDA DeltaCa(2+) in P3-10 neurons. To test whether NMDARs prevalent in neonates (NR1 plus NR2B or NR2D subunits) are inhibited by hypoxia compared with those in mature neurons (NR2A and NR2C), we expressed these receptors in Xenopus oocytes. Compared with responses in 21% O(2), hypoxia (PO(2) 17 mm Hg) reduced currents from neonatal type NR1/NR2D receptors by 25%, increased currents from NR1/NR2C by 18%, and had no effect on NR1/NR2A or NR1/NR2B. Modulation of NMDARs by hypoxia may play an important role in the hypoxia tolerance of the mammalian neonate. In addition, oxygen sensing by NMDARs could play a significant role in postnatal brain development.
Apoptosis of terminally differentiated chondrocytes in culture

During the process of endochondral ossification chondrocytes progress through stages of terminal differentiation culminating in apoptotic death. We have developed a serum-free suspension culture that allows terminal differentiation and facilitates the investigation of factors affecting chondrocyte apoptosis. We have found that chondrocytes not committed to terminal differentiation, i.e., those from the caudal region of chick embryo sterna, a region that remains cartilaginous for some months after the chick hatches, maintained high viability in serum-free suspension culture. A strong dependence of viability on culture density and sensitivity to induction of apoptosis with the protein kinase inhibitor, staurosporine, was consistent with the proposal that these chondrocytes, like nearly all cells, require intercellular communication for survival. Chondrocytes that were committed to terminal differentiation, i.e., those from the cephalic region of chick embryo sterna, a region that is replaced by bone before the chick hatches, expressed the hypertrophic phenotype but maintained their viability in culture for only approximately 6 days. Subsequent cell death was very consistent between cultures and shown to occur by an apoptotic process by analysis of DNA fragmentation and cell morphology. Short-term viability of hypertrophic chondrocytes was independent of culture density and relatively resistant to treatment with staurosporine. Induction of the hypertrophic phenotype in immature chondrocytes committed them to cell death and prevention of expression of the hypertrophic phenotype prevented cell death. We conclude that commitment of chondrocytes to terminal differentiation is associated with a commitment to apoptosis and apoptosis of hypertrophic chondrocytes in growth cartilage does not require initiation by external signals.
Direct Visualization of a Polariton Resonator in the THz Regime

We report fabrication of a THz phonon-polariton resonator in a single crystal of LiNbO3 using femtosecond laser machining with high energy pulses. Fundamental and overtone resonator modes are excited selectively and monitored through spatiotemporal imaging. The resonator is integrated into a single solid-state platform that can include THz generation, manipulation, readout and other functionalities.
Nonphotic Phase Shifting in Female Syrian Hamsters: Interactions with the Estrous Cycle:

Nonphotic phase shifting of circadian rhythms was examined in female Syrian hamsters. Animals were stimulated at zeitgeber time 4.5 by either placing them in a novel running wheel or by transferring them to a clean home cage. Placement in a clean home cage was more effective than novel wheel treatment in stimulating large (> 1.5 h) phase shifts. Peak phase shifts (ca. 3.5 h) and the percentage of females showing large phase shifts were comparable to those found in male hamsters stimulated with novel wheels. The amount of activity induced by nonphotic stimulation and the amount of phase shifting varied slightly with respect to the 4-day estrous cycle. Animals tended to run less and shift less on the day of estrus. Nonphotic stimulation on proestrus often resulted in a 1-day delay of the estrous cycle reflected in animals' postovulatory vaginal discharge and the expression of sexual receptivity (lordosis). This delay of the estrous cycle was associated with large phase advances and high activity. These results extend the generality of nonphotic phase shifting to females for the first time and raise the possibility that resetting of circadian rhythms can induce changes in the estrous cycle.
A history of newswork on Wikipedia

Wikipedia's coverage of current events blurs the boundaries of what it means to be an encyclopedia. Drawing on Gieyrn's concept of "boundary work", this paper explores how Wikipedia's response to the 9/11 attacks expanded the role of the encyclopedia to include newswork, excluded content like the 9/11 Memorial Wiki that became problematic following this expansion, and legitimized these changes through the adoption of news-related policies and routines like promoting "In the News" content on the homepage. However, a second case exploring WikiNews illustrates the pitfalls of misappropriating professional newswork norms as well as the challenges of sustaining online communities. These cases illuminate the social construction of new technologies as they confront the boundaries of traditional professional identities and also reveal how newswork is changing in response to new forms of organizing enabled by these technologies.
Advancing Safety in Construction: An Organizational, Systemic, and Cultural Approach

This panel will focus on addressing the current challenges of the construction industry within the context of Macroergonomics field research. Organizational, systemic and cultural strategies to overcome these challenges will be described. A brief introduction focusing on the unique characteristics of the construction industry and how they relate to the macroergonomics approach will be provided followed by a comprehensive overview of the breadth of the problem. Panelists will highlight successful projects or approaches related to cultural issues, immigrant and aging workforce, training effectiveness and safety culture that have a great potential to enhance safety and health in the construction industry. Language: en
Astrocytes Increase ATP Exocytosis Mediated Calcium Signaling in Response to Microgroove Structures

Following central nervous system (CNS) injury, activated astrocytes form glial scars, which inhibit axonal regeneration, leading to long-term functional deficits. Engineered nanoscale scaffolds guide cell growth and enhance regeneration within models of spinal cord injury. However, the effects of micro-/nanosize scaffolds on astrocyte function are not well characterized. In this study, a high throughput (HTP) microscale platform was developed to study astrocyte cell behavior on micropatterned surfaces containing 1 μm spacing grooves with a depth of 250 or 500 nm. Significant changes in cell and nuclear elongation and alignment on patterned surfaces were observed, compared to on flat surfaces. The cytoskeleton components (particularly actin filaments and focal adhesions) and nucleus-centrosome axis were aligned along the grooved direction as well. More interestingly, astrocytes on micropatterned surfaces showed enhanced mitochondrial activity with lysosomes localized at the lamellipodia of the cells, accompanied by enhanced adenosine triphosphate (ATP) release and calcium activities. These data indicate that the lysosome-mediated ATP exocytosis and calcium signaling may play an important role in astrocytic responses to substrate topology. These new findings have furthered our understanding of the biomechanical regulation of astrocyte cell–substrate interactions, and may benefit the optimization of scaffold design for CNS healing.
Effects of follistatin overexpression on cell differentiation in the chick embryo retina.

Abstract Although activin is expressed in the embryonic central nervous system (CNS), its possible functions in the regulation of CNS neuronal differentiation remain largely unknown. We have investigated this question in the retina, a well-characterized CNS structure previously shown to respond to activin in vitro, and to express activin subunits and receptors in vivo. RCAS retroviruses were used to overexpress in the chick retina in ovo either follistatin (FS), an activin-binding protein and inhibitor, or alkaline phosphatase (AP), as control. FS-treated retinas appeared normal until ED 8, when they showed a reduction of the inner plexiform layer, accompanied by a marked decrease in the frequency of amacrine cells. The territory lacking amacrine cells showed downregulation of transcription factors necessary for amacrine cell differentiation, such as Pax6 and AP2α, accompanied by ectopic expression of transcription factors associated with the development of horizontal or bipolar neurons, such as Prox1, Chx10 and NeuroM. Increases in cell death were also observed in FS-treated retinas. Taken together with previous in vitro studies, our results suggest that activin is a powerful regulator of neuronal differentiation in the central nervous system.
Mobility of largemouth bass in a desert lake in Arizona

Largemouth bass in Mittry lake, Arizona >360 mm total length generally remained in the same area of the lake for extended periods but some fish seemed to continually move from area to area. Sedentary and mobile fish did not differ by age or sex. Largemouth bass in Mittry lake maintained their respective behavior pattern (resident or mobile) throughout the year and did not move off-shore in the fall. The shallow depth of the lake and the moderate year round temperatures may explain this lack of seasonal movement. Harvest rates appeared to be modest. Lack of vulnerability and or angler access may explain low harvest rates.
Sustainability assessment of polygeneration processes based on syngas derived from coal and natural gas

Abstract Polygeneration systems produce chemicals, electricity, fuel, hydrogen, etc., from one or more type of feedstock. Considering their promise to provide high material and energy conversion from natural resources, polygeneration systems are recognized as promising technologies for future chemical and power industries. Sustainability assessment of these systems can provide valuable information to designers. Embedding exergy analysis and inherent safety score that quantify the efficiency and societal aspect, respectively, to complement the widely accepted economic assessment and environmental impacts assessment in a decision tree evaluation framework provides a more comprehensive, yet fast methodology to compare related processes in terms of sustainability. In this paper two different polygeneration systems, which use coal and natural gas as feed to produce di-methyl ether and power, are compared using a comprehensive sustainability assessment methodology. The results of the assessment are used to identify the more sustainable process, taking into account the economic, environmental, societal and efficiency factors.
Alizarin and tetracycline binding by bone mineral.

The nature of alizarin combination with bone is thought to be a chelation with a divalent cation on the surface of the crystal. Reactions of alizarin with bone mineral and apatite, rather than with intact bone, have been demonstrated by several investigators. In vitro titration indicates that a positive divalent or trivalent ion is capable of chelating with alizarin. Aluminum and iron form the strongest chelates, but calcium, magnesium, barium, etc. are capable of reacting. Not only does bone mineral, such as hydroxyapatite, combine with alizarin, but such other calcium-containing salts as calcium fluoride also bind the dye. The structure of alizarin that reacts with the metal ion appears to require a hydroxyquinone as the ligand. The presence of a second hydroxy group on the ring in the 2 position, or in almost any other position on the ring, facilitates the binding of the ligand to the apatite. This makes the dihydroxy molecules far more effective at low pH, and it is to this family of compounds that alizarin belongs. Alizarin red S is simply the placement of asulfonic acid group on the ring to get additional ionic structure, in order to make it soluble in water. A variety of isomers of alizarin have been studied, and all are capable of reacting with bone mineral on the same molar basis. In fact, removal of the unsubstituted ring of alizarin to form dihydroxy-naph-aquinone produces a dye still capable of reacting with apatite. The ratio of the moles of napthaquinone bound to those of anthraquinone may be explained by the relative sizes of the two dye molecules. It has been shown that phosphate competitively replaces alizarin, and that its presence in solution will prevent alizarin attachment to the surface of apatite. This result can be interpreted to mean that both the alizarin and the phosphate tend to occupy the same site when they are being adsorbed onto the surface. Tetracyclines, while more complex in structure, appear to have a binding mechanism to apatite which resembles that of alizarin.
SIMD correlator library for GNSS software receivers

Software receivers have had a discernable impact on the GNSS research community. Often such receivers are implemented in a compiled programming language, such as C or C++. A software receiver must emulate the digital signal processing (DSP) algorithms executed on dedicated hardware in a traditional receiver. The DSP algorithms, most notably correlation, have a high computational cost; this burden precludes many software receivers from running in real time. However, the computational cost can be lessened by utilizing single instruction multiple data (SIMD) operations found on modern ×86 processors. The following demonstrates how C/C++ compatible code can be written to directly utilize the SIMD instructions. First, an analysis is carried out to demonstrate why real time operation is not possible when using traditional C/C++ code is carried out. Secondly a tutorial outlines how to write and insert ×86 assembly, with SIMD operations, into C/C++ code. Performance gains achieved via SIMD operations are then demonstrated, and pseudo code outlines how SIMD operations can be employed to perform correlation. Finally, a C/C++ compatible SIMD enabled arithmetic library is added to the GPS Toolbox for use in software receivers.
Presumptive Estrogen Target Neurons Express mRNAs for both the Neurotrophins and Neurotrophin Receptors: A Basis for Potential Developmental Interactions of Estrogen with the Neurotrophins.

Estrogen and the neurotrophins regulate development, survival, and plasticity of the nervous system. We have shown previously that neurons of the developing basal forebrain and their cortical and hippocampal targets express estrogen receptor mRNA and protein. Furthermore, subsets of neurons within these regions colocalize mRNAs for neurotrophin receptors (p75NGFR, trk A, and trkB) and their cognate ligands (NGF, BDNF, and NT-3). Using combined isotopic/nonisotopic in situ hybridization histochemistry, we now demonstrate that mRNAs for the neurotrophins as well as their receptors colocalize to individual estrogen receptor mRNA-containing neurons in these regions of the developing rodent forebrain. The patterns of colocalization were both region and mRNA specific. These results suggest a potential for interactions between estrogen and the neurotrophins, including possible estrogen-stimulated, neurotrophin-mediated autocrine mechanisms that may regulate neuronal differentiation and survival during development.
Evidence for an important functional role of intracellular loop II of the lutropin receptor

Abstract The lutropin receptor (LHR) is a G protein-coupled receptor in which high affinity ligand binding occurs to the relatively large extracellular N-terminal domain. Various portions of the receptor have been mapped for their relative importance in hormone-mediated signaling. There is, however, a paucity of information available on the intracellular loops (ICL), where, along with the C-terminal cytoplasmic tail, G protein coupling is expected to occur. Site-directed mutagenesis was used to investigate the role of several conserved ionizable groups and one tyrosyl residue in ICLs I–III of the rat LHR. The pSVL expression vector, containing the LHR cDNA (wild-type and mutants), was transiently transfected into COS-7 cells, and human choriogonadotropin (hCG) binding and hCG-mediated cAMP production were determined. Several point mutants of amino acid residues in ICL II were prepared and characterized with the following results: replacements of Lys-455 and of His-460 with Glu gave mutant LHRs that failed to localize or fold properly at the cell surface as evidenced by the lack of significant binding to intact cells, although hCG binding could be detected in broken cell preparations, and a neighboring Arg-459→Glu replacement had no apparent effect on receptor trafficking, hCG binding or hCG-mediated cAMP-production. A reversal mutant in ICL II in which Glu-441, at the boundary of transmembrane helix III and ICL II, and His-460, at the interface between ICL II and transmembrane helix IV, were interchanged, exhibited hCG binding to intact cells, but the maximal cAMP level at high concentrations of ligand was less than that obtained with COS-7 cells transfected with wild-type LHR. The total number of cell surface receptors determined with the reversal mutant was less than that found with wild-type LHR. This difference, however, is not believed to be responsible for the reduced signaling, since maximal cAMP responses to hCG were obtained with comparable receptor densities of wild-type and various mutant LHRs. Other single replacements in ICL I, Lys-368→Glu and to Gln, and in ICL III, Arg-526→Glu and Tyr-528→Ser, resulted in mutant LHRs with characteristics of wild-type LHR in trafficking, hCG binding and hCG-mediated cAMP production. These findings suggest an important functional role of several amino acid residues in ICL II of LHR.
Predictors of mortality from kidney cancer in 332,547 men screened for the Multiple Risk Factor Intervention Trial.

BACKGROUND The authors examined predictors of mortality from kidney cancer in 332,547 men who were screened as part of the Multiple Risk Factor Intervention Trial. METHODS The vital status of each member of this cohort was ascertained through 1990. Death certificates were obtained from state health departments and coded by a trained nosologist. Three hundred ninety-eight deaths due to kidney cancer occurred among the cohort of 332,547 men after an average of 16 years of follow-up. The authors used the Cox proportional hazards model to study the joint associations of age, race, income, blood pressure, cigarette smoking, and use of medication for diabetes with risk of death from kidney cancer. RESULTS The authors observed independent associations with age, cigarette smoking status (relative risk[RR] = 2.02; 95% confidence interval [CI], 1.65-2.48), and systolic blood pressure (relative risk [RR] = 1.12 for systolic blood pressure level 10 millimeters of mercury higher; 95% CI, 1.06-1.18).The authors obtained similar results when deaths that occurred during the first 5 years were excluded. CONCLUSIONS These findings add to the increasing body of evidence that cigarette smoking and blood pressure level are modifiable risk factors for kidney cancer in men. Cancer 1997; 79:2171-7. © 1997 American Cancer Society.
The effects of branching and other physical properties of anionic polyacrylamides on the flocculation of domestic sewage

This investigation was undertaken to evaluate the effect of long-chain branching of anionic polyacrylamides on the flocculation of domestic sewage. The polyelectrolytes were polymerized using a redox couple, selectively hydrolyzed, and then characterized by means of light-scattering photometry. Coagulation tests were then employed to evaluate the synthesized polymers. The optimum polymer dose for suspended solids removal was used as the basis for evaluating each anionic polyacrylamide fraction with respect to its ability to flocculate domestic sewage. The results of this investigation indicated that as the weight-average molecular weight increased, the optimum polymer dose decreased. For polymers of similar molecular weights and differing radii of gyration, as the radius of gyration increased, the optimum polymer dose decreased, indicating that the “linear” polymers were more efficient in removing suspended solids than the “branched” polymers.
Determination of gross weight limit for foldaway powered wheelchairs through isometric and psychophysical strength simulations.

This study concerns the maximum weight of a powered wheelchair for transfer to and from the trunk of a car by individuals with limited exercise endurance. The loading and unloading of a folded wheelchair from the trunk of a medium size American car was simulated. Both static and dynamic simulations were carried out. The isometric (static) and psychophysical (dynamic) strengths of eight adult males while simulating the loading/unloading activities were measured. The results indicated that: (1) the maximum weight of a powered foldaway wheelchair that individuals can load in the car and unload from the car is much lower than the weight of most commercially available powered wheelchairs, and (2) static simulation of the folded wheelchair loading and unloading activity provides wheelchair weight ceiling that is easily exceeded during the dynamic simulation of the activity. The upper limit on the weight of a foldaway powered wheelchair is provided and implications of this limit on future foldaway powered wheelc...
Optimal product distribution from laminar flow reactors: Newtonian and other power-law fluids

Abstract In tubular reactors viscous fluids are in laminar flow. For reactions in series this gives a product distribution different from either plug flow or mixed flow. More importantly, laminar flow depresses the maximum amount of intermediate that can be obtained when compared to plug flow. Here we treat the simple case of an elementary two-step mechanism: (1) [ A → R → S ] Three special cases of the velocity profile in a tubular reactor are treated: uniform velocity for a plug flow reactor (PFR), parabolic velocity for a Newtonian flow reactor (NFR) and a conical velocity profile for an extreme power-law flow reactor (EPFR). The limit of complete mixing in a mixed flow reactor (MFR) is also included in comparisons. We present design charts which show quantitatively how the rate constant ratio affects the product distribution, and we compare the maximum possible amount of intermediate obtainable from reactors whose flow patterns can be characterized by the four models above. These results are important because they allow an evaluation of the detrimental effects when the ideal plug flow assumption for tubular reactors is inappropriate and a convective model more accurately describes the situation. The entire range of power-law fluid behavior is represented on these plots and we clearly show that even the worst flow pattern which arises is still much preferable to mixed flow.
Visible electroluminescence in Si/adsorbed gas superlattice

We report a strong and extremely stable electroluminescence (EL) from silicon based EL device. The active layer of the device utilizes a crystalline Si/O superlattice, grown by molecular beam epitaxy with in-situ oxygen exposure. Oxygen exposure is used to limit the growth of oxides to a monolayer in order to continue the silicon epitaxial growth and to create a highly localized interaction between the oxygen and silicon atoms. The visible EL is peaked at 1.8 - 2 eV, showing no degradation in a six month life-test under continuous operation, longer than other silicon based schemes in the literature. The efficacy of both photoluminescence and electroluminescence is similar to better than that from porous silicon. The robustness and stability of the c-Si/O superlattice opens the door for a silicon chip combining IC with integrated optics.
Treatment of advanced male breast cancer

The modalities used to treat 27 male patients with metastatic breast cancer at Memorial Hospital from 1957--1979 are reviewed. The overall objective orchiectomy response rate was 48% (11/23). The median response was 11 months (6--96 months). The median survival in responders was 58 months, whereas the median survival in orchiectomy failures was 24 months. Four patients had estrogen receptor protein determinations (ERP). Two positive ERP patients and one borderline ERP patient responded (18--34 months). One ERP-negative patient failed orchiectomy. The number of major ablations in this series (two responses/two adrenalectomies, two failures/two hypophysectomies) does not permit conclusions, although review of the literature suggests that major ablation may be valuable in patients responding to orchiectomy. Two of three patients who refused ablative therapy responded (three months, ten months) to single agent provera. Administering stilbesterol to the ten-month responder and to the patient who failed provera resulted in two additional responses (four months, continuing, and 22 months). Of six patients who failed orchiectomy and subsequently received chemotherapy, four patients responded (7--40 months). The median survival in these patients was 40 months (33--44 months). This review supports the importance of orchiectomy in the treatment of metastatic male breast cancer. Although the numbers are small, these data suggest that estrogen receptor determinations may be useful in selecting patients for orchiectomy. Selective additive hormone therapy may be useful in patients who refuse orchiectomy. Chemotherapy may provide worthwhile palliation in patients who fail orchiectomy.
Politics of Le passé simple

The uproar incited by Driss Chraibi's Le passe simple resulted from the political climate at the time of the novel's publication in 1954, skewing the interpretation of the text. The novel allegorically describes tensions between different political groups in terms of family conflict. The hero Driss's rebellion against his father, ’Le Seigneur‘,hence assumes the dimensions of a revolt against the king, as he tries to rally his brothers to a ‘coup d'etat’. The author's images, both historical and novelistic, are modelled on the French revolution and the family romance novels that were its literary complement. Le passe simple draws a historical blueprint for the Moroccan nation, one that was not executed in the short run, but was partially realised over time. The novel dramatises (and predicts) the conflict between the monarchy and elites such as the intelligentsia, symbolised as a father‐son conflict. Most analyses have reduced the work to its psychoanalytic dimensions, eliding its political substratum.
Liver resections in metastatic gastric cancer.

Background The 5-year survival of patients receiving standard-of-care chemotherapy for metastatic gastric cancer (MGC) to the liver is <2%. This review examines the published data on liver resections for MGC and analyses the rationale for potentially aggressive surgical management.
A Theory of Activity Scheduling Behavior

Recognizing that travel is a demand derived from individuals' desires to undertake out-of-home activities, researchers in the area of travel demand have become increasingly interested in analyzing and predicting individuals' decisions about activity participation. This paper formulates a theory of activity scheduling for urban workers. In this theory, each worker chooses whether or not to participate in an out-of-home, nonwork activity in each of five blocks of time defined around their obligatory trip to work. In addition, conditional on the decision to participate in any particular time block, the chosen duration of participation is analyzed.The econometric problems of operationalizing the theory are resolved, and the resulting model is applied to analyze the scheduling behavior of a sample of workers in the Minneapolis-St Paul metropolitan area. This case study suggests some significant directions for further research on activity analysis.
Septation of the respiratory and digestive tracts in human embryos: crucial role of the tracheoesophageal sulcus.

Esophageal atresia and tracheoesophageal fistula, common malformations of the respiratory and digestive tracts, are of unsettled pathogenesis. Part of the difficulty in understanding these abnormalities arises from the uncertainties about the normal developmental processes in the region. This study examined the development and fate of the tracheoesophageal septum. Normal human embryos from the Carnegie Embryological Collection and fetuses from the Hopkins Pathology Collection were examined, and reconstructions of selected specimens were made from photomicrographs of serial histologic sections. The results show that the lung bud appears in Carnegie stage 12, rapidly enlarges, and bend caudally, thereby producing a sulcus between the foregut and the respiratory system on its caudal aspect. The cranial aspect of this tracheoesophageal sulcus remains fixed at the levels of the first cervical vertebra throughout subsequent embryonic and fetal development. At the same time the trachea and esophagus elongate to bring those parts of the respiratory and digestive systems into their definitive anatomic positions. Examination of the tracheoesophageal sulcus shows that its growth-limiting properties may be explained by its catenoidal configuration. Catenoidal, or saddle-shape, sulci have been shown to have similar regional growth-limiting properties in the embryonic heart. These regions contrast with outwardly convex regions in both the developing heart and lung where growth of the tissues occurs. The observations made here suggest that the origin of the tracheoesophageal malformations must be sought in a configurational abnormality in the area of the developing lung bud in Carnegie stage 12. © 1994 Wiley-Liss, Inc.
Ray tracing in gradient-index media

The problem of ray tracing in inhomogeneous media has been examined in an attempt to find an accurate yet computationally efficient method. Several numerical techniques have been compared. It is shown that Montagnino’s Taylor-series-expansion method [ J. Opt. Soc. Am.58, 1667 ( 1968)] is superior to Euler’s method, which is a standard numerical method for solving the differential equation. It is also shown that, by a transformation of the independent coordinate from the physical path length to the optical path length, more-accurate optical path calculations may be obtained.
Clinical perspectives for regulatory T cells in transplantation tolerance

Three main types of CD4+ regulatory T cells can be distinguished based upon whether they express Foxp3 and differentiate naturally in the thymus (natural Tregs) or are induced in the periphery (inducible Tregs); or whether they are FoxP3 negative but secrete IL-10 in response to antigen (Tregulatory type 1, Tr1 cells). Adoptive transfer of each cell type has proven highly effective in mouse models at preventing graft vs. host disease (GVHD) and autoimmunity. Although clinical application was initially hampered by low Treg frequency and unfavorable ex vivo expansion properties, several phase I trials are now being conducted to assess their effect on GVHD following hematopoietic stem cell transplantation (HSCT) and in type I diabetes. Human Treg trials for HSCT recipients have preceded other indications because GVHD onset is precisely known, the time period needed for prevention relatively short, initial efficacy is likely to provide life-long protection, and complications of GVHD can be lethal. This review will summarize the clinical trials conducted to date that have employed Tregs to prevent GVHD following HSCT and discuss recent advances in Treg cellular therapy.
Effectiveness of Bootstrap Bias Correction in the Context of Clock Offset Estimators

Estimating and correcting the offset between two or more clocks is an important problem in data communication networks. For example, Internet telephony depends on network routers having a common notion of time, and cellular networks provide a higher quality of service by using transmission protocols that depend on neighboring base stations knowing the offset that exists between their local clocks. In previous work it was shown that bootstrap bias correction of Paxson's well-known estimator of clock offset produces an estimator with improved bias and mean squared error (MSE) properties. In addition, the ordered-BLUE (o-BLUE) under an exponential distribution for network delays was derived, and its bootstrap bias-corrected form was shown to have lower bias and MSE than the bootstrap bias-corrected form of Paxson's estimator when network delays follow lognormal, gamma, and Weibull distributions. The inferred robustness of the bias-corrected o-BLUE to the assumed distribution of network delays is an attractiv...
Flow based oversampling technique for multiscale finite element methods

Oversampling techniques are often used in porous media simulations to achieve high accuracy in multiscale simulations. These methods reduce the effect of artificial boundary conditions that are imposed in computing local quantities, such as upscaled permeabilities or basis functions. In the problems without scale separation and strong non-local effects, the oversampling region is taken to be the entire domain. The basis functions are computed using single-phase flow solutions which are further used in dynamic two-phase simulations. The standard oversampling approaches employ generic global boundary conditions which are not associated with actual flow boundary conditions. In this paper, we propose a flow based oversampling method where the actual two-phase flow boundary conditions are used in constructing oversampling auxiliary functions. Our numerical results show that the flow based oversampling approach is several times more accurate than the standard oversampling method. We provide partial theoretical explanation for these numerical observations.
Transcriptional regulator of oxidative stress-inducible genes: direct activation by oxidation

The oxyR gene positively regulates genes induced by oxidative stress in Salmonella typhimurium and Escherichia coli. Purification of the OxyR protein showed that oxidized but not reduced OxyR activates transcription of oxidative stress-inducible genes in vitro. Conversion between the two forms of OxyR is rapid and reversible. Both the oxidized and the reduced forms of the OxyR protein are capable of binding to three diverse sequences upstream of OxyR-regulated promoters, but the interactions of the two forms of OxyR with the promoter regions are different. The results suggest that direct oxidation of the OxyR protein brings about a conformational change by which OxyR transduces an oxidative stress signal to RNA polymerase.
SU-E-T-531: Verification of Acuros Dose Calculation Accuracy in Lung SBRT.

Purpose: The AcurosXB Advanced Dose algorithm (Varian Medical Systems) was reported to give more accurate dose calculation in heterogeneous medium compared with the AAA algorithm. In this work, a validation of AcurosXB dose calculation accuracy is performed for use in lungSBRT.Methods: A CIRS (Computerized Imaging Reference Systems, Inc.) lung phantom was used with a tissue equivalent 2cm circular target inserted into the lung. The phantom was customized to hold a Gafchromic EBT2 film through the center of the target. The phantom was CT scanned, and single field (3cm by 3cm anterior/lateral) plans, as well as VMAT plans were created for 6 and 10 MV energies with different delivery modalities (with/without a flattening filter). All plans delivered 500 cGy to the PTV which was the target plus 0.5 cm uniform margin. Plans were delivered on a Varian TrueBeamTM STx using image guidance to locate the isocenter. The film dose was compared with Eclipse v10.0 dose calculated with AAA and Acuros algorithms using FilmQA software (3cognition). Monte Carlo simulations (BEAMnrc/DOSXYZnrc) were performed to further validate AcurosXB calculations. Results: Within the GTV, AAA and Acuros algorithms were in good agreement with the film measurements to within 2% mean dose difference. AAA calculation consistently overestimated the dose to the lung surrounding the GTV by 5–9% for the 10MV beam and 2–4% for the 6MV beam. Acuros and MC calculations were found to be in good agreement with EBT2 film measurement within 2% at 6MV including the build up and build down regions. Conclusions: The CIRS customized lung phantom with EBT2 films was found to be an excellent tool in validating the dose calculation algorithm for lungSBRT application. AcurosXB was found to be more accurate than AAA algorithm in lung and near lung/tissue interfaces.
Histopathology of human laser thermal angioplasty recanalization

Laserprobe thermal-assisted balloon, angioplasty (LTBA) has demonstrated promising initial clinical results in recanalizing stenotic or occluded superficial femoral and popliteal arteries. Over the past year we have obtained six specimens of laserprobe thermal (LT) and LTBA treated total occlusions (avg. length 12 cm) for histopathologic examination from patients who were treated for limb salvage. Three tissue specimens were obtained acutely, and one was obtained at 6, 8, and 13 days, respectively, after laser angioplasty at the time of revision for complications or failed procedures. Serial histologic sections of the treated LT segments demonstrated recanalization of atherosclerotic lesions to approximately 60-70% of the probe diameter. The LT channels were lined by a thin layer of carbonized or coagulated tissue and several layers of cell necrosis. The histology of the thermal injury was similar regardless of whether it was produced by the heated metal cap or by free argon laser energy. Stellate balloon angioplasty fractures were frequently filled with thrombus. Analysis of these human LT and LTBA specimens revealed that the thermal device produces a confined injury through the path of least resistance. Balloon dilatation produces fragmented cracks in the vessel wall, which appear to be more thrombogenic than the carbonized LT surface. With improved guidance methods, LTBA shows potential for continuing development.
TESTING FOR PARAMETER STABILITY IN EXECUTIVE REMUNERATION FUNCTIONS

Executive compensation equations are estimated separately for three groups of firms, under the contention that the determinants of executive remuneration may depend upon the form of and degree of regulation in an industry. Empirical evidence obtained for three separate years lends support to that notion.
The aging response and creep of DRA composites

The hardening rates of 6061/SiC/20w and 6061/Al2O2/15p are significantly higher than that of wrought 6061 Al. The whisker composite retains its tensile strength over a broad range of aging times (up to 500 hours). Under identical aging conditions, the tensile strength of the whisker composite is about 65% higher than that of the particulate composite and wrought aluminum. Likewise, the stiffness of the whisker composite is approximately 60% higher than that of the other two materials (which have similar stiffnesses). At 350°C, the whisker composite has about 55% higher strength than the particulate composite and the wrought aluminum, in comparison with a 111% advantage at room temperature. The whisker composite shows better resistance to creep than the particulate composite and wrought aluminum; the improvement is almost two orders of magnitude in terms of the steady-state creep rate.
Statistical design and optimization for adaptive post-silicon tuning of MEMS filters

Large-scale process variations can significantly limit the practical utility of microelectro-mechanical systems (MEMS) for RF (radio frequency) applications. In this paper we describe a novel technique of adaptive post-silicon tuning to reliably design MEMS filters that are robust to process variations. Our key idea is to implement a number of redundant MEMS resonators to form an array and then optimally select a subset of these resonators to achieve the desired frequency response. Several new CAD algorithms and methodologies are proposed to optimize and configure the design variables of the proposed MEMS resonator array. A MEMS design example demonstrates that the proposed post-silicon tuning is able to reduce the ripple of the channel filter gain by 7× over other traditional approaches.
Preattentive considerations for gaze-contingent image processing

Gaze-contingent interfaces must provide adequate peripheral information to the viewer to preserve perceptual fidelity. specifically, it has been shown that preattentive (or preview) benefit must be preserved so that scene perception is not disrupted. In this paper we review recent attempts at peripheral degradation of digital imagery. We suggest that to be successful such degradation must preserve potential future visual attractors and, furthermore, not introduce artificial ones. We present a simple multiresolution image processing approach that can be utilized for this purpose. The feasibility of gaze-contingent processing has recently been questioned. In their paper, Stelmach and Tam processed images by low-pass filtering, effectively smoothing extrafoveal regions. The authors then quantized DCT coefficients in the periphery, introducing blocking artifacts. In our paper, we simulate these results and claim that neither of these methods is suitable for GC interfaces. Alternatively, we implement a simple multiple region of interest (ROI) multiresolution scheme in an attempt to degrade the periphery while preserving attentional cues. We evaluate three variants of this approach: a linear degradation function, a nonlinear function, and a function matching human visual system (HVS) acuity. The HVS-matching multiple-ROI algorithm gives good compression and alleviates the degradation of potential visual attractors. Furthermore, MIP mapping offers efficient implementation of the algorithm, making it a good candidate for gaze-contingent applications.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Background Calibration of Gain Errors in $\Pi\Delta \Sigma$ A/D Converters

This paper describes a method of calibrating gain errors in each channel of Hadamard modulated parallel delta-sigma (ΠΔΣ) converters. The ΠΔΣ converters extend traditionally bandwidth-limited ΔΣ modulators to applications such as wireless communications that require high-resolution wide-bandwidth converters. The focus of this paper is on the development and convergence of an adaptive calibration algorithm. A hardware implementation that verifies this paper can be found in an earlier work. The calibration is done in real time and is accomplished by adding an additional channel that is linearly dependent on the ΠΔΣ channels that are used. By introducing this redundancy, an adaptive recursive least squares (RLS) algorithm is used to correct for gain errors within the channels. To demonstrate the calibration scheme, an eight-channel ΠΔΣ converter with second-order ΔΣ modulators and an oversampling ratio of 4 was simulated in MATLAB. Simulation results show a 40-dB reduction in unwanted distortion tones caused by 1% gain mismatches.
Phosphatidylcholine and Phosphatidylethanolamine Behave as Substrates of the Human MDR1 P-Glycoprotein†

The multidrug resistant cell line CEM/VBL300 and the parental CEM T-lymphoblastic cell line from which it was derived were used to study the accumulation of fluorescent phospholipid analogs of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS). The fluorescent analogs NBD-PC, NBD-PE, and NBD-PS and [3H]PC were delivered in liposomes prepared by ethanol injection. Fluorescence microscopy demonstrated decreased accumulation of the NBD-PC analog in the multidrug resistant cell line compared to the parental cell line. Verapamil enhanced NBD-PC accumulation in the resistant cells. Similar results were obtained with insect cells expressing high levels of recombinant human MDR1. Elimination of NBD fluorescence on the outer leaflet of the plasma membrane with dithionite permitted quantification of the internal cellular fluorescence by FACS analysis. The drug resistant CEM/VBL300 cells accumulated approximately 10% the amount of NBD-PE and 20% the amount of NBD-PC compared to CEM drug sensitive cells. No difference in internal accumulation of NBD-PS was found between the drug resistant and drug sensitive cell lines. The internal accumulation of NBD-PE and NBD-PC was enhanced by the MDR reversal agents verapamil, cyclosporin A, and SDZ PSC 833 in the CEM/VBL300 cells but not in the CEM cells. The increased accumulation was dose dependent, and the relative potency of the reversal agents paralleled their ability to circumvent multidrug resistance. In addition, the monoclonal antibody UIC2 directed against the P-glycoprotein produced similar results. The evidence presented here suggests that PC and PE but not PS behave as substrates for human MDR1 P-glycoprotein.
Genericity and Logical Form

In this paper I propose a novel treatment of generic sentences, which proceeds by means of different levels of analysis. According to this account, all generic sentences (I-generics and D-generics alike) are initially treated in a uniform manner, as involving higher-order predication (following the work of George Boolos, James Higginbotham and Barry Schein on plurals). Their non-uniform character, however, re-emerges at subsequent levels of analysis, when the higher-order predications of the first level are cashed out in terms of quantification over individuals: this last step, I suggest, involves knowledge concerning the lexical meaning of the predicates in question.