cssi/SciSciGPT-SciSciNet huggingface dataset:
Relationship of the acylation of membrane esterases and proteins to the teratogenic action of organophosphorus insecticides and eserine in developing hen eggs.

Abstract The yolk sac membrane from hen eggs contains esterases that hydrolyze phenyl phenylacetate (PPA) and are sensitive to inhibition, both in vitro and in vivo, by many organophosphorus compounds and by eserine. These esterases are the principal proteins in the membrane which are phosphorylated by 3H-diisopropyl phosphorofluoridate. Inhibition of this mixture of PPA-hydrolyzing esterases in vivio does not correlate with the induction of teratogenesis because they react with both teratogenic and non-teratogenic acylating agents. However, electrophoresis studies indicate that inhibition in vivo of one or more separable components making up a very small proportion of the total membrane esterase mixture occurs with teratogenic but not with non-teratogenic treatment schedules. Thus, dialkylphosphorylation or methylcarbamoylation of this reactive membrane component(s) in vivo may initiate a sequence of events leading to embryonic abnormalities. This postulated mode of action is analogous to that proposed earlier by British workers in the production of delayed neurotoxicity by some organophosphorus compounds.
ITLinQ: A new approach for spectrum sharing

We consider the problem of spectrum sharing in wireless communication networks composed of multiple source-destination pairs. We define a novel concept of information-theoretic independent sets (in short, ITIS) which indicates the sets of source-destination pairs in the network inside each of which, treating interference as noise is information-theoretically optimal (to within a constant gap). Then, we propose a new spectrum sharing scheme called information-theoretic link scheduling (in short, ITLinQ), which at each time schedules those users that form an ITIS. We first provide a performance guarantee of the ITLinQ scheme through characterizing the fraction of the capacity region that it can achieve in a network with source and destination nodes spread randomly in a fixed area. Moreover, we will show how to implement the ITLinQ scheme in a distributed fashion by using an initial 2-phase signaling mechanism which provides the required channel state information at all the nodes. Finally, we compare the performance of the distributed ITLinQ scheme with similar state-of-the-art spectrum sharing mechanisms, such as FlashLinQ, through numerical analysis and show that it can exhibit a sum-rate gain of more than a 100%, while keeping the complexity at the same level.
Charged amino acid residues 997-1000 of human apolipoprotein B100 are critical for the initiation of lipoprotein assembly and the formation of a stable lipidated primordial particle in McA-RH7777 cells.

We previously demonstrated that a portion, or perhaps all, of the residues between 931 and 1000 of apolipoprotein (apo) B100 are required for the initiation of apoB-containing particle assembly. Based on our structural model of the first 1000 residues of apoB (designated as apoB:1000), we hypothesized that this domain folds into a three-sided lipovitellin-like “lipid pocket” via a hairpin-bridge mechanism. We proposed that salt bridges are formed between four tandem charged residues 717–720 in the turn of the hairpin bridge and four tandem complementary residues 997–1000 located at the C-terminal end of the model. To identify the specific motif within residues 931 and 1000 that is critical for apoB particle assembly, apoB:956 and apoB:986 were produced. To test the hairpin-bridge hypothesis, the following mutations were made: 1) residues 997–1000 deletion (apoB:996), 2) residues 717–720 deletion (apoB:1000Δ717–720), and 3) substitution of charged residues 997–1000 with alanines (apoB:996 + 4Ala). Characterization of particles secreted by stable transformants of McA-RH7777 cells demonstrated the following. 1) ApoB:956 did not form stable particles and was secreted as large lipid-rich aggregates. 2) ApoB:986 formed both a lipidated particle that was denser than HDL3 and large lipid-rich aggregates. 3) Compared with wild-type apoB:1000, apoB:1000Δ717–720 displayed the following: (i) significantly diminished capacity to form intact lipidated particles and (ii) increased propensity to form large lipid-rich aggregates. 4) In striking contrast to wild-type apoB:1000, (i) apoB:996 and apoB:996 + 4Ala were highly susceptible to intracellular degradation, (ii) only a small proportion of the secreted proteins formed stable HDL3-like lipoproteins, and (iii) a majority of the secreted proteins formed large lipid-rich aggregates. We conclude that the first 1000 amino acid residues of human apoB100 are required for the initiation of nascent apoB-containing lipoprotein assembly, and residues 717–720 and 997–1000 play key roles in this process, perhaps via a hairpin-bridge mechanism.
Unleashing the power of comparative oncology models in nanomedicine research

The pathway from discovery of novel candidate drugs, including nanomedicine compounds, to FDA approval is lengthy and may be difficult to navigate. Oftentimes, investigational drugs are appropriately abandoned early in the development pathway due to preclinical failure. Other novel compounds may look quite promising in rodent models and preclinical trials, but prove disappointing when tested in human patients. In fact, only 5% of drugs entering Phase I human cancer clinical trials in the US are ultimately approved. Given the enormous cost, in terms of both financial investment and delay in progress toward improved patient outcome, there is a critical need for a more reliable and efficient process. One solution may be to improve translatability of our preclinical data by including trials in cancer-bearing pet dogs in the drug development pathway.
Generalised absolute stability analysis and synthesis for Lur'e-type descriptor systems

Lur'e-type descriptor systems (LDS) described by a linear time-invariant descriptor system with feedback-connected nonlinearities are considered. Firstly, the notion of generalized absolute stability (GAS) is defined for LDS and a necessary and sufficient condition (NASC) is derived. It is shown that GAS for LDS implies that the nominal system is admissible and the overall system is globally exponentially stable. Then, a sufficient condition for a generalised absolutely stable LDS to be of index one and solvable is presented. Furthermore, a method to estimate the decay rate of the solutions to the system is obtained. Finally, the synthesis problem is addressed and an approach to designing a state-feedback controller that renders the closed-loop system is generalised absolutely stable with a given decay rate is given. A numerical example illustrates the approach.
Dynamics of ablation plume particles generated during excimer laser corneal ablation

Background and Objective: Although the empirical characteristics of ArF excimer laser corneal ablation have been well documented, the exact ablation mechanisms are not well understood. The present paper reports a quantitative analysis of corneal ablation plumes using in situ time resolved laser light scattering and Raman spectroscopy. Study Design/Materials and Methods: Bovine corneas were used as the ArF excimer laser ablation targets. Light scattering data were recorded from the ablation plume as a function of height above the tissue surface and as function of delay time with respect to the ablative ArF laser pulse. Results: Raman spectra of the ablation plume allow identification of the particles as water. Mean plume particle diameters are found to decrease with height, while the particle volume fractions are relatively constant. The total volume of plume particles correlates well with the total volume of water in the ablated corneal tissue. Conclusion: The finding of a non-evolving plume composed of water spherules, combined with the excellent agreement between total volume of water in the plume and the content of water in the ablated corneal tissue, support the concept of photodecomposition or “cold ablation” for corneal tissue during ArF excimer laser ablation. © 1995 Wiley-Liss, Inc.
Combined H1 and H2 receptor blockade attenuates the cardiovascular effects of high dose atracurium in rabbits

Abstract Large doses of atracurium (1.5 mg/kg) (six times the ED 95 ) have been reported to provide adequate conditions for rapid sequence endotracheal intubation within 60 seconds in humans. However, this dose can result in significant histamine release and systemic hypotension. We therefore studied the efficacy of histamine receptor blockade in attenuating this response. Four groups of five rabbits were pretreated as follows: Group I — control, Group II — H 1 blockade (1 mg/kg diphenhydramine), Group III —H 2 blockade (cimetidine 4 mg/kg), and Group IV — H 1 and H 2 blockade (diphenhydramine 1 mg/kg and cimetidine 4 mg/kg). All rabbits were anesthetized and then 1.8 mg/kg (six times the rabbit ED 95 ) atracurium was administered. Group I rabbits experienced a decrease in MAP of 12.2 mmHg after one minute, a change that was significantly greater than Group IV in which MAP decreased by 0.8 mmHg (p 1 or H 2 receptor blockade alone was associated with intermediate changes in MAP not significantly different from control. We conclude that combined H 1 and H 2 receptor blockade attenuates the cardiovascular effects associated with large doses of atracurium in the rabbit and that this combination of antagonist drugs might have similar effectiveness in humans.
Preoperative and Postoperative MR Evaluation of Congenital Heart Disease in Children

The goals of imaging in the setting of congenital heart disease (CHD) are to identify subjects with CHD, establish the need for treatment and the optimal mode of treatment, define anatomy and hemodynamics for treatment planning, monitor for complications after treatment, and determine the optimal timing of repeat intervention. Echocardiography (echo) is the primary modality used in the initial diagnosis of CHD, which can provide an excellent overview of relevant cardiovascular anatomy, flow, and function. In the preoperative period, cardiovascular magnetic resonance imaging (CMR) can provide additional information in pediatric patients who have poor acoustic windows or when additional detail is required for surgical planning. In the postoperative period, the goals of imaging are to assess ventricular and valvular function and the status of grafts, conduits, and baffles for early detection of complications, and to determine timing of surgical intervention. Conduits are prosthetic or homograft tubes used to connect structures that are too far from each other for a direct anastomosis. Baffles are intracardiac patches that channel flow from one part to another (veinvein, vein-chamber, chamber-artery, or arteryartery) (Table 1). Complications common to conduits, baffles, and shunts include leaks, anastomotic strictures, external stenoses, and interference with adjacent native structures. Additionally, in the case of conduits, kinking or stenosis owing to the formation of a thick endothelial peal can also occur. The failure rate with echo increases in the postoperative setting and in older children with limited acoustic window. In such situations, CMR has become the gold standard noninvasive imaging modality of choice. By providing a large field of view coupled with arbitrary planes of evaluation, and 3-dimensional (3D) imaging with high spatial resolution, CMR is considered the best technique for evaluation of the right ventricle (RV) and branch pulmonary arteries, as well as conduits, baffles, and shunts created during CHD repair. CMR also provides serial accurate and reproducible measurements of ventricular function, stroke volumes, and regurgitant fractions. In this article, current cardiac MR imaging techniques and specific questions that arise in the preoperative and postoperative evaluation of the most common CHD anomalies referred to CMR in pediatric patients are reviewed.
The benefits of beneficence: Rewards of hospice volunteering

Hospice volunteering can provide many benefits to the volunteer as well as to the hospice program. Identification of these benefits, which may be characterized as being of the body, mind, and spirit, is helpful in the recruitment of new volunteers as well as in the retention of current ones. It is important for hospice programs to find ways to assist volunteers to attain these rewards.
Pathogenesis and therapy of neuropathies associated with monoclonal gammopathies

Approximately 10% of patients with peripheral neuropathy of otherwise unknown etiology have an associated monoclonal gammopathy. Both the neuropathies and the monoclonal gammopathies in these patients are heterogeneous, but several distinct clinical syndromes that may respond to specific therapies can be recognized. It is important to recognize these syndromes because monoclonal gammopathies also occur in 1% of the normal adult population, and in some cases, monoclonal gammopathies are coincidental and unrelated to the neuropathy. In patients with IgM monoclonal gammopathies, IgM M proteins frequently have autoantibody activity and are implicated in the pathogenesis of the neuropathy. IgM M proteins that bind to myelin-associated glycoprotein (MAG) have been shown to cause demyelinating peripheral neuropathy; anti-GM1 antibody activity is associated with predominantly motor neuropathy, and anti-sulfatide or chondroitin sulfate antibodies are associated with sensory neuropathy. The IgM monoclonal gammopathies may be malignant or nonmalignant, and polyclonal antibodies with the same specificities are associated with similar clinical presentations in the absence of monoclonal gammopathy. IgG or IgA monoclonal gammopathies are associated with neuropathy in patients with osteosclerotic myeloma or the POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy myeloma, and skin changes). Amyloidosis or cryoglobulinemic neuropathies can occur with either IgM or IgG and IgA monoclonal gammopathies. Therapeutic intervention depends on the specific clinical syndrome but is generally directed at removing the autoantibodies, reducing the number of monoclonal B cells, and interfering with the effector mechanisms.
Singular Sturm–Liouville Theory on Manifolds

In this paper we investigate Schrodinger operators L=−Δg+a(x) on a compact Riemannian manifold (M, g), where the potential function a(x) is assumed to be continuous, but not necessarily bounded, outside of some closed set Σ⊂M of measure zero. Under certain geometric hypotheses on Σ and growth conditions on a(x) as x→Σ, we prove that the Dirichlet extension of L is bounded from below with discrete spectrum; in many cases, a(x) is allowed to approach −∞ as x→Σ. We also consider conditions on Σ and a(x) under which the Sturm–Liouville theory of L is “singular” in that no boundary conditions are needed to specify the eigenvalues and eigenfunctions of L; in particular, this occurs when the domain of L does not depend on boundary conditions, for example, when L is essentially self-adjoint or more generally “essentially Dirichlet” (a new property that we define). The behavior of L on weighted Sobolev spaces is also discussed. In most of the paper we assume that Σ is a k-dimensional submanifold without boundary, but in the last few sections we generalize our results to stratified sets.
Observations on the Salting of Brick Cheese

Summary Brick cheese curd was made by a commonly used method and subjected to various salting treatments. Measurements of acidity, moisture and salt content were made at regular intervals and the cheese were graded. Salt penetrated the cheese quickly in the outer layer but eight weeks of curing elapsed before the salt content was practically uniform throughout the cheese. Long periods in the salt tank, highly concentrated brines, and early-salting increased the amount of salt in the cheese. Dry-salting was effective but not as uniform as brine-salting. Desirable results were obtained when the Brick cheese absorbed salt to the extent of approximately 2% of its total weight. Excessive salting caused hard, curdy body, unnatural white color, slow ripening, loss of yield, and delayed lactose fermentation; low salt encouraged abnormal fermentations and caused weak body and open texture.
Thymomas with prominent signet ring cell–like features: a clinicopathologic and immunohistochemical study of 10 cases

Summary Ten cases of an unusual growth pattern of thymomas are presented. The patients were 8 men and 2 women between the ages of 43 and 62 years. Clinically, 6 patients presented with symptoms of chest pain, cough, and shortness of breath, whereas 4 patients were asymptomatic. Surgical resection of the mediastinal mass was performed in all patients obtaining tumors that varied in size from 4 to 11 cm in greatest dimension. Grossly, the tumors were described as round and well defined, which, at cut surface, showed a firm consistency with a slight lobulated appearance. Areas of necrosis and/or hemorrhage were not present. Histologically, all the tumors showed similar growth pattern characterized by the presence of cells arranged in small cords dissecting fibroconnective tissue and, in some areas, resembling "signet ring" cells. Mitotic activity was not present. Using the Masaoka staging system, 6 cases were in stage I, and 4 cases were in stage II. Histochemical stains for periodic-acid Schiff stain with diastase and mucicarmine were negative for intracytoplasmic mucin. Immunohistochemical studies for CAM5.2 and cytokeratin 5/6 showed a strong positive reaction, whereas thyroid transcription factor 1, epithelial membrane antigen, calretinin, α -fetoprotein, and CD31 were all negative. Follow-up information obtained for 7 patients between 1 and 12 years showed that all these patients are alive and well. The current cases highlight an unusual histologic growth pattern of thymomas that likely can be confused with other tumors of the anterior mediastinum that may require different treatment approaches and carry a different prognosis.
Behaviour-genetic analysis of Phormia regina II. Detection of a single, major-gene effect from behavioural variation for Central Excitatory State (CES) using hybrid crosses

Abstract Converging evidence from replicated hybrid analyses (and from selection and single-pair mating; Tully & Hirsch 1982) points to a single, major-gene correlate of the central excitatory state (CES) in pure breeding lines of the black blow-fly, Phormia regina. Analysis of reciprocal F1s reveals no X-chromosome or cytoplasmic effects. Biometrical analysis indicates significant additive and environmental phenotypic variance components. No net dominance deviation or dominance variance is detectable (which is consistent with absence of intralocular dominance). An estimate of the number of segregating loci is near 1. A more general non-parametric method fails to reject the one-gene model.
Alphavirus-Induced Encephalomyelitis: Antibody-Secreting Cells and Viral Clearance from the Nervous System

ABSTRACT Sindbis virus (SINV) infection of the central nervous system (CNS) provides a model for understanding the role of the immune response in recovery from alphavirus infection of neurons. Virus clearance occurred in three phases: clearance of infectious virus (days 3 to 7), clearance of viral RNA (days 8 to 60), and maintenance of low levels of viral RNA (>day 60). The antiviral immune response was initiated in the cervical lymph nodes with rapid extrafollicular production of plasmablasts secreting IgM, followed by germinal center production of IgG-secreting and memory B cells. The earliest inflammatory cells to enter the brain were CD8 + T cells, followed by CD4 + T cells and CD19 + B cells. During the clearance of infectious virus, effector lymphocytes in the CNS were primarily CD8 + T cells and IgM antibody-secreting cells (ASCs). During the clearance of viral RNA, there were more CD4 + than CD8 + T cells, and B cells included IgG and IgA ASCs. At late times after infection, ASCs in the CNS were primarily CD19 + CD38 + CD138 − Blimp-1 + plasmablasts, with few fully differentiated CD38 − CD138 + Blimp-1 + plasma cells. CD19 + CD38 + surface Ig + memory B cells were also present. The level of antibody to SINV increased in the brain over time, and the proportion of SINV-specific ASCs increased from 15% of total ASCs at day 14 to 90% at 4 to 6 months, suggesting specific retention in the CNS during viral RNA persistence. B cells in the CNS continued to differentiate, as evidenced by accumulation of IgA ASCs not present in peripheral lymphoid tissue and downregulation of major histocompatibility complex (MHC) class II expression on plasmablasts. However, there was no evidence of germinal center activity or IgG avidity maturation within the CNS.
On the optimal harvesting of age-structured populations: Some simple models☆

Abstract In this paper we develop optimal harvesting policies for age-structured populations using a model for which the basic equations reduce to a pair of ordinary diffential equations for the total population and the per-capita birth-rate. Our assumptions insure the existence of a critical size Pc(t) which maximizes the instantaneous growth-rate at time t. We study the infinite-horizon problem, using the overtaking criterion of optimality, and show that: for a large population with ample per-capita birth-rate the optimal policy is to instantly reduce the stock to the critical value Pc(0), and then to harvest along the path Pc(t); for a sufficiently small population it is optimal to refrain from harvesting until the population reaches Pc(t), and then to harvest along Pc(t) for all subsequent time; for a large population with a small per-capita birth-rate, it is generally best to initially remove a given amount of stock, then to refrain from harvesting until the population reaches Pc(t), and finally to harvest alongPc(t).
THE LOCAL DYNAMICS OF NATIONAL DISSENT: THE ECUADORIAN PRONUNCIAMIENTOS OF 1826

(1992). The Local Dynamics of National Dissent: The Ecuadorian Pronunciamientos of 1826. The Historian: Vol. 55, No. 2, pp. 289-302.
Dynamics of electronic transmission in metal/organic/metal structures

Abstract We study the dynamics of electronic transport across a metal/conjugated-oligomer/metal structure using a novel selfconsistent Green's function approach developed recently. We find a crossover from the free electron-like to polaron-like behavior in transport with increasing phonon frequency of the oligomer. These results have implications for transport experiments on polymer light-emitting diodes and molecular wires.
Reversal of changes in left ventricular diastolic filling associated with normal aging using diltiazem.

Abstract Congestive heart failure is a common problem in clinical geriatrics and often the result of diastolic rather than systolic dysfunction. 1 Normal aging is associated with a reduction in the rate of calcium ion uptake by the sarcoplasmic reticulum. 2 Because intracellular handling of calcium may affect isovolumic relaxation and left ventricular (LV) compliance, a calcium antagonist may be beneficial. The pattern of LV diastolic filling may be accurately characterized by both pulsed Doppler transmitral flow velocities 3 and radionuclide scintigraphy. 4 The present study tests the hypothesis that a calcium antagonist, diltiazem, may be effective in reversing the impairment of early diastolic LV filling seen in elderly subjects.
3-D Surface Description Using Curvature Properties

This paper presents a method to extract and represent significant physical properties of a surface, using curvature properties of this surface. We compute curvature in 4 different directions and detect extrema and zero-crossings for each of these one dimensional curves. Since this computation is very noise sensitive, we filter these features using a scale-space tracking approach: we smooth the image with Gaussian masks of increasing variance, detecting features at the smoothest level and localizing them at the original one. We then partially group these features into junctions which correspond to significant physical properties, such as depth discontinuities, surface discontinuities, smooth extrema, and link them into curves. We believe that these descriptions capture most of the information present in the original image, but are more suited to further processing, such as matching with a model. We then illustrate this technique with several examples.
Simulated-annealing as a tool to identify parameter values associated with epileptiform activity in single-neuron and network compartmental models

Background Automated parameter search algorithms, such as simulated annealing, seek to tune a model's parameters to reproduce important features of a target data set. A match function compares the model and target data to generate a goodness of fit and is crucial because it reflects which target features are considered of interest. Previous work has shown the effectiveness of combining simulated annealing with time-domain match functions (e.g., spike timing and least mean square (LMS) of membrane potentials) to tune a compartmental model of a cortical pyramidal cell [1].
Incorporating heterogeneity with store-level aggregate data

This paper introduces a methodology to incorporate heterogeneity in the analysis of store level aggregate data. The proposed model is validated using two sets of scanner panel data, for tuna and ketchup, and their corresponding weekly aggregate data. The model recovers the true parameters with acceptable accuracy. The model has several advantages over the previous aggregate models, such as the linear model, the semilog model, and the log-log model. First, the cross-price elasticities estimated from the model show the asymmetric responses to the price promotions very close to those from the logit model applied to the panel data. Second, the model shows better prediction performance.
Lipolysis Control: The Plot Thickens

The complex process of lipolysis mobilizes fatty acids from adipocyte triglyceride stores for energy production in muscle and other organs during fasting and exercise. In this issue of Cell Metabolism , Yang, et al. identify G0S2 as a regulator of the key enzyme, adipose triglyceride lipase.
Composite surface for blocking bacterial adsorption on protein biochips

The design and fabrication of protein biochips requires characterization of blocking agents that minimize nonspecific binding of proteins or organisms. Nonspecific adsorption of Escherichia coli, Listeria innocua, and Listeria monocytogenes is prevented by bovine serum albumin (BSA) or biotinylated BSA adsorbed on SiO(2) surfaces of a biochip that had been modified with a C(18) coating. Biotinylated BSA forms a protein-based surface that in turn binds streptavidin. Because streptavidin has multiple binding sites for biotin, it in turn anchors other biotinylated proteins, including antibodies. Hence, biotinylated BSA simultaneously serves as a blocking agent and a foundation for binding an interfacing protein, avidin or streptavidin, which in turns anchors biotinylated antibody. In our case, the antibody is C11E9, an IgG-type antibody that binds Listeria spp. Nonspecific adsorption of another bacterium, Escherichia coli, is also minimized due to the blocking action of the BSA. The blocking characteristics of BSA adsorbed on C(18)-derivatized SiO(2) surfaces for construction of a protein biochip for electronic detection of pathogenic organisms is investigated.
Comments on "Optimal Controls for Out-of-Plane Motion about the Translunar Libration Point"

I N the last paragraph of the Synoptic for Heppenheimer's recent paper,1 the following statement is made: "These results are in conflict with a period control proposed by Farquhar.2 Farquhar's solution, however, involves substantially higher cost and in addition represents a single optimum and not a family of local optima. Moreover, his solution is objectionable on theoretical grounds since its characteristics are strongly dependent upon the small parameter e, the lunar eccentricity, and his solution actually fails to exist for e = 0. The preceding solution (i.e., Heppenheimer's solution), though computed for the case e = 0, requires only slight modification to accommodate the actual case of e 0 appears artificial." A re. ply to Heppenheimer's criticism is given below. Heppenheimer's remarks concerning the lunar eccentricity are unfounded since Ref. 2 used a model that neglected this quantity. Evidently Heppenheimer is referring to the small frequency difference c ss uy - co2 = 0.07647. Clearly, there is nothing "artificial" about e > 0. Furthermore, it was never stated that the "phase-jump control" of Ref. 2 is the most economical z-axis control. Actually, it had already been pointed out in a previous paper3 that a continuous sinusoidal z-axis control is more economical than the phase-jump control. The primary motivation for introducing the phase-jump method in Ref. 2 was to demonstate that it would be possible to guarantee a nonocculted trajectory even when the time interval between control pulses is as long as 3 months. The fuel consumption estimates of Ref. 1 also deserve some comment. The average A 7 cost for the impulsive z-axis control discussed in Ref. it can be written ast AF = (1) where € = «„-«,= 0.07647, «„ = 1.86265, co2 = 1.78618, \l/c = eA£/2, and A£ is the time interval between impulses. (For A£ = 7.334 days, \f/c = 0.06449 in normalized units which corresponds to Mode 1 of Heppenheimer's paper.) The amplitude of the z oscillation, AZ) must be large enough to guarantee that the satellite trajectory in the yz plane never enters the occulted zone. To determine AZ) it is necessary to begin with the basic equations for the satellite trajectory in
What they're reading—web communities for learning community work

The author reviews several Web-based resources that can help untangle the complex work of launching and sustaining learning communities.
Deformable gas-filled microbubbles targeted to P-selectin.

Ultrasound contrast microbubbles have been successfully targeted to a number of intravascular disease markers. We hypothesized that targeted delivery could be improved further, by making the microbubbles deformable, leading to increased microbubble–endothelium adhesion contact area and stabilized adhesion. Activated leukocytes utilize such strategy; they deform after binding to inflamed endothelium in the vasculature. Lipid-shell microbubbles were targeted to the endothelial inflammatory protein P-selectin with a monoclonal anti-P-selectin antibody attached to the microbubble shell. Deformable microbubbles were created by controlled pressurization with partial gas loss, which generated an average excess shell surface area of ∼30% and the formation of outward-projected wrinkles and folds. Targeted microbubble adhesion and deformability were assessed in the parallel plate flow chamber under shear flow. Sustained adhesion of deformable microbubbles at wall shear stresses between 0.4 and 1.35 dyn/cm 2 was consistently better than adhesion of wrinkle-free microbubbles. Over this shear range, targeted wrinkled microbubbles were deformed by shear flow, unlike wrinkle-free microbubbles. In a murine cremaster inflammation model, a significant improvement of deformable microbubble targeting was observed by intravital microscopy. Overall, the mechanical aspects of adhesion, such as particle shape, deformability and surface microstructure, are important in engineering efficient site-targeted particle-based agents for medical imaging and therapy.
Disclosure risk measures for microdata

We define several disclosure risk measures for microdata. We analyze disclosure risk based on the disclosure control techniques applied to initial microdata. Disclosure Control is the discipline concerned with the modification of data containing confidential information about individual entities, such as persons, households, businesses, etc. in order to prevent third parties working with these data from recognizing entities in the data and thereby disclosing information about these entities. In very broad terms, disclosure risk is the risk that a given form of disclosure will occur if a masked microdataset is released. Microdata represents a series of records, each record containing information on an individual unit. The disclosure risk measures presented in the paper are validated in our experiments.
Selective Inactivation of p53 Facilitates Mouse Epithelial Tumor Progression without Chromosomal Instability

We examined the selective pressure for, and the impact of, p53 inactivation during epithelial tumor evolution in a transgenic brain tumor model. In TgT121 mice, cell-specific inactivation of the pRb pathway in brain choroid plexus epithelium initiates tumorigenesis and induces p53-dependent apoptosis. We previously showed that p53 deficiency accelerates tumor growth due to diminished apoptosis. Here we show that in a p53+/− background, slow-growing dysplastic tissue undergoes clonal progression to solid angiogenic tumors in all animals. p53 is inactivated in all progressed tumors, with loss of the wild-type allele occurring in 90% of tumors. Moreover, similar progression occurs in 38% of TgT121p53+/+ mice, also with loss of at least one p53 allele and inactivation of p53. Thus, the selective pressure for p53 inactivation, likely based on its apoptotic function, is high. Yet, in all cases, p53 inactivation correlates with progression beyond apoptosis reduction, from dysplasia to solid vascularized tumors. Hence, p53 suppresses tumor progression in this tissue by multiple mechanisms. Previous studies of fibroblasts and hematopoietic cells show that p53 deficiency can be associated with chromosomal instability, a mechanism that may drive tumor progression. To determine whether genomic gains or losses are present in tumors that progress in the absence of p53, we performed comparative genomic hybridization analysis. Surprisingly, the only detectable chromosomal imbalance was partial or complete loss of chromosome 11, which harbors the p53 gene and is thus the selected event. Flow cytometry confirmed that the majority of tumor cells were diploid. These studies indicate that loss of p53 function is frequent under natural selective pressures and furthermore that p53 loss can facilitate epithelial tumor progression by a mechanism in addition to apoptosis reduction and distinct from chromosomal instability.
Application re-mapping for fault-tolerance in ambient intelligent systems

As technology advances, devices become smaller and cheaper, making it possible to build systems containing large numbers (possibly hundreds, or more) of miniature processing elements. Such platforms, although superficially similar to traditional distributed systems, pose additional unique challenges. Due to the desire to minimize costs, coupled with the sheer numbers of devices, it will be difficult to perform manufacture-time testing, and runtime-failures will likewise be common. One challenge is to efficiently harness the capabilities of large numbers of low power (and relatively low performance) processing elements, in the presence of failures such as depleted battery resources, as well as those due to unpredictable sources (e.g., electrical and mechanical failures). It will however be possible to employ a fraction of the multitude of resources as redundant or spare devices, re-mapping applications onto them, from failing ones.This paper investigates the use of code migration as a general means of performing such application re-mapping, in the presence of intermittent communication and device failures, as well as limited battery resources. A new technique, Pre-Copying with Remote Execution (PCRE), an extension of code migration which enables more efficient application re-mapping in the presence of energy and communication constraints for symmetric applications, is presented.It is shown that PCRE provides a 28.6% improvement in system lifetime and 9.8% improvement in energy efficiency for the applications investigated, over the baseline code migration strategy. Naturally, the re-mapping of applications involves overheads in computation and communication, and PCRE reduces these overheads to within 10% of the ideal case of doubled energy resources.
Morphology-dependent optical absorption and conduction properties of photoelectrochemical photocatalysts for H2 production: A case study

Efficient photoelectrochemical H2 production by solar irradiation depends not only on the photocatalyst’s band gap and its band-edge positions but also on the detailed electronic nature of the bands, such as the localization or delocalization of the band edges and their orbital characteristics. These determine the carrier transport properties, reactivity, light absorption strength, etc. and significantly impact the material’s efficiency as a photoconverter. The localization or delocalization of the band edges may arise either due to the orbital nature of the bands or the structural morphology of the material. A recent experimental report on a photocatalyst based on s/p orbitals showed very poor performance for H2 production despite the delocalized nature of the s/p bands as compared to the d-bands of transition metal oxides. It is then important to examine whether this poor performance is inherent to these materials or rather arises from some experimental limitations. A theoretical analysis by first-princ...
Proteomic database mining opens up avenues utilizing extracellular protein phosphorylation for novel therapeutic applications

Summary Recent advances in extracellular signaling suggest that extracellular protein phosphorylation is a regulatory mechanism outside the cell. The list of reported active extracellular protein kinases and phosphatases is growing, and phosphorylation of an increasing number of extracellular matrix molecules and extracellular domains of trans-membrane proteins is being documented. Here, we use public proteomic databases, collagens – the major components of the extracellular matrix, extracellular signaling molecules and proteolytic enzymes as examples to assess what the roles of extracellular protein phosphorylation may be in health and disease. We propose that novel tools be developed to help assess the role of extracellular protein phosphorylation and translate the findings for biomedical applications. Furthermore, we suggest that the phosphorylation state of extracellular matrix components as well as the presence of extracellular kinases be taken into account when designing translational medical applications.
pH Effects on Measurements of Ionized Calcium and Ionized Magnesium in Blood

Abstract Context.—It is well known that the concentration of ionized calcium in blood is affected by the pH of the specimen, since hydrogen ions compete with calcium for binding sites on albumin and other proteins. However, the relationship between pH and ionized magnesium concentration is not as well characterized. Objective.—To determine the effects of pH on ionized magnesium concentration over a wide range of pH values in serum or plasma. Design.—Both ionized calcium and ionized magnesium concentrations were measured in 3 sets of samples. (1) Pools of serum or whole blood at different pH values (7.20–7.60) achieved by adding a constant volume of acid or base (diluted solutions of either hydrochloric acid or sodium hydroxide) plus saline. These pools consisted of 2 serum and 3 heparinized whole blood pools collected from leftover blood remaining in clinical specimens in the Clinical Chemistry and Blood Gas Laboratories, respectively, at Duke University Medical Center. (2) Five whole blood specimens obta...
How Can Urine Microscopy Influence the Differential Diagnosis of AKI

Acute kidney injury (AKI), which is associated with increased morbidity and mortality, is a relatively common complication in hospitalized patients (1–3). The most common cause of AKI in hospitalized patients is acute tubular necrosis (ATN) followed by prerenal azotemia (4). Because therapies and prognoses for prerenal azotemia and ATN differ substantially, early clinical differentiation is desirable to assist the clinician in patient treatment. For example, an early diagnosis of prerenal azotemia would facilitate early treatment to correct volume status and potentially prevent ATN. Also, in the setting of AKI from ATN, it would avoid worsening of the clinical course with incorrect therapies such as excessive volume resuscitation leading to pulmonary edema and other untoward end organ effects. Presently, the diagnosis of AKI is primarily based on changes in serum creatinine concentration, blood urea nitrogen, and urine output. These biomarkers are very helpful in diagnosis of AKI but rarely help in discriminating between ATN and prerenal azotemia. Urine biochemistry measures, such as fractional excretion of sodium and urea, also provide important information in the differentiation of AKI into traditional categories of prerenal azotemia and ATN (5–9) when the patient is not on diuretics or does not have underlying chronic kidney disease. Urinalysis and urine microscopy are also commonly used to differentiate these two causes of AKI and are generally accepted as critical for the evaluation of patients with kidney disease. Urine microscopy is the best surrogate for the histologic state of the kidney and is not affected by underlying chronic kidney disease or presence of medications. As a result, urine sediment analysis is considered an integral part of the clinical workup of kidney disease in hospitalized patients with AKI. Urinary microscopy in patients with ATN classically is described as containing renal tubular epithelial cells, renal tubular epithelial …
Instrumentation issues in implementation science

Like many new fields, implementation science has become vulnerable to instrumentation issues that potentially threaten the strength of the developing knowledge base. For instance, many implementation studies report findings based on instruments that do not have established psychometric properties. This article aims to review six pressing instrumentation issues, discuss the impact of these issues on the field, and provide practical recommendations.
Ultralow-threshold sapphire substrate-bonded top-emitting 850-nm VCSEL array

Oxide-confined top-emitting vertical-cavity surface-emitting-laser (VCSEL) 8 /spl times/ 8 arrays were designed and fabricated with ultralow thresholds. The arrays were flip-chip bonded onto sapphire substrates and mounted in pin-grid-array packages as optical transmitter arrays. By using the offset-contact bonding process, we were able to obtain very high yield for hybridized devices without damaging the VCSEL mesas. Room-temperature lasing thresholds below 70 /spl mu/A were found from some of these packaged VCSELs with measured oxide apertures 2.6 /spl mu/m in diameter. The emission spectrum at an injection current of 70 /spl mu/A showed a full-width at half-maximum linewidth of less than 2.5 A. Polarization properties were also confirmed from the output of the device. The superior performance was attributed to the optimized size and placement of the confinement aperture and the precise alignment of the gain profile of the active region to the mode of the resonant cavity.
In Search Of An Optimal Local Navier-Stokes Preconditioner

Local preconditioning for the Navier-Stokes equations may be called optimal if it equalizes all propagation and dissipation time-scales, for all combinations of Mach number and Reynolds number. Previously designed preconditioners are ineffective for certain combinations of low Reynolds number and low Mach number; in addition some of these create a growing mode, making the PDE-system unstable. (Users may regain stability through an implicit discretization.) In this paper we first review the forms and properties of all previously published N-S preconditioners on the basis of the 1-D N-S equations, then derive an optimal preconditioning matrix for these equations. We find again that it creates an unstable mode; a sensitivity analysis shows that optimal preconditioning and stability are mutually exclusive. Two possible remedies are suggested and briefly investigated: (1) to redefine the complex condition number in a way more appropriate for explicit discretizations; (2) to reformulate the N-S equations as a larger first-order system of hyperbolic-relaxation equations and base the preconditioner on this system. The latter approach appears most promising.
Real-time and real-space observation of plasma oscillation in GaAs

A plasma oscillation of electrons and holes is generated in GaAs by a quantum interference and control technique, and is temporally and spatially resolved by detecting an induced second-harmonic generation process.
Death by Design Programmed Cell Death in Cardiovascular Biology and Disease

Abstract Programmed cell death (apoptosis) is recognized, increasingly, as a contributing cause of cardiac myocyte loss with ischemia/reperfusion injury, myocardial infarction, and long-standing heart failure. Although the exact mechanisms initiating apoptosis in these in vivo settings remain unproven, insights into the molecular circuitry controlling apoptosis more widely suggest the potential to protect mammalian ventricular muscle from apoptosis through one or more of these pathways, by pharmacological means or, conceivably, gene transfer.
Measurement of Inhaled Corticosteroid Adherence in Inner-City, Minority Children with Persistent Asthma by Parental Report and Integrated Dose Counter

Parents often overreport adherence to asthma treatment regimens making accurate assessment of medication adherence in clinical practice difficult. This study was conducted to compare two adherence assessment methods clinicians may choose from when assessing patient inhaled corticosteroid (ICS) adherence: parental report and dose counter measurements of metered-dose inhaler (MDI) actuation. Participants included children (N = 50) with persistent asthma and their parents (N = 50). At enrollment, children received a new, marked ICS at the dose prescribed by their physician. Thirty days following enrollment, we measured ICS adherence by parental report and objectively, with a dose counter. Parental report overestimated ICS adherence when compared to dose counter. We found a statistically significant overall difference between parental report and objectively measured adherence. A dose counter that most ICS inhalers are equipped with may be a more reliable alternative measure of ICS adherence in a clinical practice setting.
Signal sequences specify the targeting route to the endoplasmic reticulum membrane.

In the yeast Saccharomyces cerevisiae, only a subset of preproteins that are translocated across the ER membrane require the function of the signal recognition particle (SRP), suggesting that an alternative, SRP-independent pathway must exist (Hann, B.C., and P. Walter. 1991. Cell. 67:131-144). We have established that the two targeting pathways function in parallel. Mutant alleles of SEC62 and SEC63 were isolated that specifically impaired the translocation of SRP-independent preproteins in vivo and in vitro, whereas SRP-dependent preproteins were unaffected. Based on this analysis, preproteins fall into three distinct classes: SRP dependent, SRP independent, and those that can use both pathways. Pathway specificity is conferred by the hydrophobic core of signal sequences. Our studies show a previously unrecognized diversity in ER-directed signal sequences, that carry structural information that serves to identify the route taken.