cssi/SciSciGPT-SciSciNet huggingface dataset:
High serum CA19-9 levels are associated with an increased risk of cholangiocarcinoma in patients with intrahepatic duct stones: a case–control study

Hepatolithiasis is a known risk factor for cholangiocarcinoma (CC). Due to the high risk of complications that accompany endoscopic and surgical stone removal, it is often difficult to decide whether it is beneficial to remove intrahepatic ductal stones. We conducted a case–control study to determine the risk of developing CC and the benefit of stone removal in patients with hepatolithiasis. Twenty-three patients with CC group between 2002 and 2012 were included in this study. For each patient with CC, four control patients with hepatolithiasis were enrolled based on age and sex matching. Finally, 115 patients with hepatolithiasis were enrolled. The mean length of time that intrahepatic stones were present was 116.57 (±98.77) months in the CC group and 80.56 (±101.10) months in the control group. History of gastrectomy [OR 5.756 (1.329–24.930), p = 0.019], history of choledochoenterostomy (OR 4.938 [1.129–21.595], p = 0.034), serum CA19-9 level [OR 1.001 (1.000–1.001), p = 0.022], and complete removal of stones [OR 0.167 (0.052–0.539), p = 0.003] were independent predictive factors of CC. In patients who had undergone incomplete removal of stones, the occurrence of CC was significantly reduced overall as well as in a subgroup of patients with elevated CA19-9 (p = 0.015 and p = 0.006, respectively) compared to patients with a CA19-9 of 22 U/mL).
Observations of Variability in the South Pacific Subtropical Gyre

Abstract Variability of the subtropical gyre in the South Pacific Ocean was investigated using high-resolution expendable bathythermograph sections along a repeated track between New Zealand and Hawaii. The southern part of the section sampled most of the zonal flow in the subtropical gyre with the eastward flowing branch between New Zealand and Fiji and the westward branch extending north of Fiji to approximately 10°S. The time series began in September 1987 and extended through 1994, averaging four cruises every year. The geostrophic shear field was calculated, relative to 800 m, with the aid of a mean T − S relationship. Variability was present at a broad range of spatial and temporal scales but annual fluctuations were particularly prominent. The authors conclude that 30 snapshots of temperature, measured over a period of seven years, are sufficient to resolve the annual cycle of the gyre-scale circulation along the transect. The shape and intensity of the gyre varied seasonally throughout the water c...
Genotype in BRCA‐associated Breast Cancers

Women with BRCA1 or 2 mutations are at high risk for breast cancer. For BRCA1, a trend of increasing risk has been associated with increasing downstream (3') location for mutations compared to the upstream (5') mutations in the gene. For BRCA2, an increased risk of breast cancer has been associated with mutations outside of the ovarian cancer cluster region (OCCR). We sought to determine the mutation position in BRCA-associated breast cancers and whether or not there was a genotype-phenotype correlation. Breast cancer patients with BRCA1/2 mutations were identified by a search of a prospectively maintained data base. Mutation site, patient, and tumor characteristics were determined through retrospective review. One hundred and sixty-four patients with BRCA1-associated breast cancer and 109 patients with BRCA2-associated breast cancer were identified. Among patients with BRCA1-associated cancers, 86 (52%) had mutations in the 5' half of the gene. Among patients with BRCA2-associated breast cancers, 40 (37%) had OCCR mutations. Although BRCA1-associated tumors were more likely to be ER/PR- than BRCA2-associated cancers (p < 0.0001), there was no difference in the tumor characteristics among BRCA1 or BRCA2-associated cancers based on mutation location. In this single-institution study, over half of BRCA1-associated and over a third of BRCA2-associated breast cancers were associated with putative lower risk mutations. Although we cannot exclude the possibility that mutations in these regions confer a lower relative risk for breast cancer, vigilance in cancer screening and prevention remains necessary. Further studies in genotype/phenotype correlation are needed to individualize prevention strategies.
A Method for the Estimation of Peroxidase Activity in Milk

Summary The method which has been described possesses the advantages of speed, convenience, and sensitivity. In this method p -phenylenediamine is oxidized by lactoperoxidase in the presence of hydrogen peroxide. Under the conditions of the assay, the amount of color developed is proportional to time. The influence of hydrogen peroxide concentration, p -phenylenediamine concentration, and enzyme concentration was studied and the optimum conditions were selected.
Stability predictions for combustors with acoustic absorbers and continuous combustion distributions

The realistic case of a continuous distribution of combustion sources in the axial direction is considered in the investigation. The results obtained are compared with those of an earlier study conducted by Baer et al. (1974) concerning the stability of partially lined combustors with distributed combustion. There is a substantial upward shift of the curves in all cases relative to the curves obtained in the first analysis. The increase in chamber stability indicated is traced to some important damping effects associated with source terms which had been neglected in the previous study.
Conformational transitions and structural deformability of EcoRV endonuclease revealed by crystallographic analysis.

Abstract The structures of wild-type and mutant forms of the unliganded Eco RV endonuclease dimer have been determined at 2.4 A resolution in a new crystal lattice. Comparison of these structures with that of the free enzyme determined with different packing constraints shows that the conformations of the domain interfaces are not conserved between crystal forms. The unliganded enzyme and the enzyme-DNA complex delineate two distinct quaternary states separated by a 25° intersubunit rotation, but considerable conformational heterogeneity, of the order of 10° domain rotations, exists within each of these states. Comparison of the free enzyme structure between the two crystal forms further reveals that the C-terminal 28 amino acid residues are disordered and undergo an extensive local folding transition upon DNA binding. Introduction of the mutation T93A at the DNA-binding cleft causes large-scale effects on the protein conformation. Structural changes in the mutated unliganded enzyme propagate some 20 to 25 A to the dimerization interface and lead to a rearrangement of monomer subunits. Comparative analysis of these structures, a new structure of the enzyme cocrystallized with DNA and calcium ions, and previously determined cocrystal structures suggests important roles for a number of amino acid residues in facilitating the intersubunit motions and local folding transitions. In particular, the T93A structure reveals a pathway through the protein, by which DNA-binding may cause the domain movements required for proper alignment of catalytic groups. The key active-site residue Glu45 is located on a flexible helix inside this pathway, and this provides a direct means by which essential catalytic functions are coupled to the protein conformational change. It appears that indirect perturbation of the Glu45 conformation via an altered quaternary structure may be a contributing factor to the decreased catalytic efficiency of T93A, and this mechanism may also explain the diminished activities of other active site variants of Eco RV.
Posterior Stabilization of Cervical Spine Fractures and Subluxations Using Plates and Screws

Posterior stabilization of cervical spine fractures and subluxations with metal plates and screws is commonly used in Europe, but has rarely been employed by neurosurgeons in North America, where stabilization has usually been achieved with wires supplemented by bone grafts or acrylic. The limitations of the more commonly used stabilization techniques include the failure to achieve rotational stability, the necessity for intact laminae, and the requirement for bone grafting. We therefore examined the efficacy of posterior cervical plating in 19 patients who had posttraumatic instability of the cervical spine between C3 and C7 without residual spinal cord compression and 1 patient who had a subluxation as a result of osteomyelitis. Two patients had no neurological deficit, 4 had partial deficits, and 14 had no neurological function below the level of injury. Operation was performed after patients were medically stable and maximal reduction of fractures was achieved (usually within 48 hours). The plates are made of vitallium and contain two or three holes 13 mm apart through which 16-mm screws are placed bilaterally into the center of the articular masses of two or three adjacent vertebrae to stabilize one or two motion segments. Bone grafting is not performed. Patients are mobilized on the day after operation in a Philadelphia collar, which is worn for 3 months. Fourteen patients had stabilization of one motion segment and 6 had stabilization over two motion segments. The mean follow-up is 9.2 months. In a single patient with ankylosing spondylitis, plate fixation failed when screws pulled out. No patient experienced neurological deterioration as a result of the operative procedure.(ABSTRACT TRUNCATED AT 250 WORDS)
Initial experience with a combined multidetector CT and biplane digital subtraction angiography suite with a single interactive table for the diagnosis and treatment of neurovascular disease

Background A combined imaging suite is useful in the diagnosis and treatment of vascular disease involving the head and neck. This study demonstrates the utility of a multidetector row CT and biplane digital subtraction angiography (DSA) system (hybrid suite) with a single interactive table for the evaluation and treatment of neurovascular disease. Methods 30 patients were studied utilizing the hybrid suite. Direct intra-arterial and selective intravenous injection of contrast with CT imaging (IA-CTA and IV-CTV) was performed in nine vascular tumors, three intracranial arteriovenous malformations, four spinal vascular lesions, one aneurysm and two inferior petrosal sinus sampling cases. Angiography with CT perfusion (CTP) imaging was obtained in five temporary balloon occlusion tests, two ischemic stroke and two vasospasm cases. A CT scan of the head was obtained in two cases during aneurysm coiling. The value of the IA-CTA and IV-CTV images compared with conventional CT and MRI images was qualitatively assessed. Results All studies were technically successful with no complications. IA-CTA and IV-CTV were useful in the diagnosis and treatment of vascular disease. All IA-CTA and IV-CTV images were qualitatively graded as superior to conventional imaging. CTP imaging provided information about the penumbra and area of infarction in five temporary balloon test occlusions, two ischemic stroke and two vasospasm cases. A CT scan of the head provided timely information in two aneurysm coiling cases. The hybrid suite allowed angiography and CT scanning to be performed immediately without patient transfer. Conclusion This hybrid suite improves the diagnostic and therapeutic capabilities of treating a multitude of neurovascular diseases.
Discrete Dynamic Programming and Capital Allocation

Dynamic programming algorithms are developed for optimal capital allocation subject to budget constraints. We extend the work of Weingartner [Weingartner, H. M. 1966. Capital budgeting of interrelated projects: Survey and synthesis. Management Sci.127, March 485--516.] and Weingartner and Ness [Weingartner, H. M., D. N. Ness. 1967. Methods for the solution of the multi-dimensional 0/1 knapsack problem. Oper. Res.151, January--February 83--108.] by including multilevel projects, reinvesting returns, borrowing and lending, capital deferrals, and project interactions. We are able to handle dynamic programming models with several state variables because the optimal returns are monotone non-decreasing step functions. Computational experience with a variety of problems is reported.
An estimate for the rate of convergence of the eigenfunction expansions of functions of bounded variation

A quantitative version of Titchmarsh's theorem is given concerning the eigenfunction expansion of functions of bounded variation
Calculating the expected frequencies of potential secondary structure in nucleic acids as a function of stem length, loop size, base composition and nearest-neighbor frequencies

A formula is derived to estimate the expected frequency of potential secondary structure of a given stem length and loop size in a random sequence of nucleotides of known length and composition. An example is provided using the SV40 sequence which shows significant non-randomness in stem length but whose significance is reduced by more than six orders of magnitude by taking nearest neighbor frequencies into account.
Empirical formulas for design and optimization of 1.5 mu m InGaAs/InGaAsP strained-quantum-well lasers

The effects of strain and number of quantum wells on optical gain, differential gain, and nonlinear gain coefficient in 1.55- mu m InGaAs/InGaAsP strained-quantum-well lasers are theoretically investigated. Well-approximated empirical expressions are proposed to model these effects. Using these formulas, one can easily and accurately predict the performance of a laser diode for a given structure. Therefore, these empirical formulas are useful tools for design and optimization of strained quantum well lasers. As a general design guideline revealed from the empirical formulas, the threshold current is reduced with the compressive strain, and the modulation bandwidth is most efficiently increased with the number of wells. >
Of dramatology: Action in the form of tools and machines (Wiener, Plato, Aristotle, Latour, Shakespeare, Bacon)

This article examines Norbert Wiener's notions about self-reproducing machines in his work on cybernetic systems; it then compares Wiener's arguments to classical discussions of tools and instruments, with particular reference to Plato and Aristotle. The article argues that all three writers provide a way of thinking about the category of ‘action’ in ‘posthuman’ terms: they offer examples of a mode of artificial, performative action that has been dissociated from subjects and persons and that flourishes in technology, in theater, and in the philosophy of science. The article closes by briefly considering how this model of posthuman action might help us understand two areas in early modern writing: the drama of Shakespeare and the philosophy of Francis Bacon.
Cyclic GMP is involved in the excitation of invertebrate photoreceptors.

The hyperpolarizing receptor potential in vertebrate rod photo-receptors appears to be mediated by the second messenger, cyclic GMP. Injection of cGMP into rods1,2 or application of cGMP to inside-out membrane patches3 activates a conductance resembling that produced by light. Light produces a rapid reduction of cGMP in living rods4, leading to closure of sodium channels and membrane hyperpolarization. In most invertebrate photoreceptors the response to light is depolarizing. We have investigated whether cGMP is involved in controlling the increase in sodium conductance that underlies this depolarization5. We show here that injection of cGMP into Limulus photoreceptors produces a depolarization that mimics the receptor potential. We also show that the cGMP concentration of the squid retina increases rapidly during exposure to light. These results support the hypothesis that cGMP mediates the light-induced depolarization in invertebrate photoreceptors and suggests that vertebrate and invertebrate phototransduction may be more similar than previously thought.
Economic modeling of HIV treatments.

PURPOSE OF REVIEW: To review the general literature on microeconomic modeling and key points that must be considered in the general assessment of economic modeling reports discuss the evolution of HIV economic models and identify models that illustrate this development over time as well as examples of current studies. Recommend improvements in HIV economic modeling. RECENT FINDINGS: Recent economic modeling studies of HIV include examinations of scaling up antiretroviral (ARV) in South Africa screening prior to use of abacavir preexposure prophylaxis early start of ARV in developing countries and cost-effectiveness comparisons of specific ARV drugs using data from clinical trials. These studies all used extensively published second-generation Markov models in their analyses. There have been attempts to simplify approaches to cost-effectiveness estimates by using simple decision trees or cost-effectiveness calculations with short-time horizons. However these approaches leave out important cumulative economic effects that will not appear early in a treatment. Many economic modeling studies were identified in the gray literature but limited descriptions precluded an assessment of their adherence to modeling guidelines and thus to the validity of their findings. SUMMARY: There is a need for developing third-generation models to accommodate new knowledge about adherence adverse effects and viral resistance.
Mapping of Interactions in the Pitch Memory Store

A technique obtaining a precise mapping of interactive effects in the pitch memory store is described. Subjects were required to compare two tones for pitch when these were separated by a 5-second interval during which six other tones were played. In the second serial position of the intervening sequence there was placed a tone whose pitch bore a critical relationship to the pitch of the first test tone. When the critical intervening tone was identical in pitch to the first test tone, memory facilitation was produced. As the separation in pitch between these two tones increased, errors rose progressively, peaked at a separation of 2/3 tone, and declined roughly to baseline at a whole tone separation. It is concluded that the pitch memory store is arranged logarithmically in a highly ordered and specific fashion.
Immunoblotting of pollen proteins: Tween 20 mediates nonspecific binding of gammaglobulins to immunoblots of oak-pollen proteins

Oak-pollen extracts, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretically transferred onto nitrocellulose, demonstrated extensive banding in the absence of human sera or with nonatopic sera with both a horseradish peroxidase-conjugated goat antihuman IgE and 125I-labeled rabbit antihuman IgE. When the nonionic detergent Tween 20 was removed from all incubations and washes, negative banding appeared, corresponding to bands that were clearly visible when Tween 20 had been used as a blocking agent. When Tween 20 was reintroduced, the bands reappeared. These results demonstrate that, although Tween 20 is effective in blocking unbound sites on nitrocellulose membranes, this and other nonionic detergents may cause nonspecific binding to immunoblots of oak-pollen proteins. Thus, care must be used in the interpretation of immunoblots to detect allergens when Tween 20 is used as the blocking agent.
The Effect of Affective State on Virtual and Face-to-Face Group Performance

The purpose of this study was to examine the relationship between affective state and virtuality on group creativity, negotiation, and information exchange. Over 100 students watched a film clip to induce a positive or neutral mood and performed tasks as dyads or triads either face-to-face or distributedly. Although the affective state manipulation did not affect performance, the more positive affect the groups reported, the more words the groups used to communicate. Distributed groups did not generate more ideas or act less cooperatively than face-to-face groups. However, face-to-face triads performed better on the information exchange task than distributed triads; distributed dyads outperformed face-to-face dyads. An interaction between affective state and group type was also found for trust in the computerized communication medium. Implications are discussed.
Does voltage predict return to work and neuropsychiatric sequelae following electrical burn injury

Voltage has historically guided the acute management and long-term prognosis of physical morbidity in electrical injury patients; however, few large studies exist that include neuropsychiatric morbidity in final outcome analysis. This review compares high (>1000 V) to low ( 1000 V), low voltage (<1000 V), flash arc, and lightning. Demographics, hospital course, and follow-up were recorded to determine physical and neuropsychiatric morbidity. Differences among cohorts were tested for statistical significance. Over 5 years, 2548 patients were admitted to the burn center, including 115 patients with electrical injuries. There were 110 males and 5 females, with a mean age of 35 years (range, 0.75-65 years). The cause of the electrical injury was high voltage in 60 cases, low voltage in 25 cases, flash arc in 29 cases and lightning in 1 case. The mean total body surface area burn was 8% (range, 0%-52%). The etiology was work-related electrical injury in 85 patients. Mean follow-up period was 352 days with 13 (11%) patients lost to follow-up. Patients with high voltage injuries had significantly larger total body surface area burn, longer ICU stays, longer hospitalizations, and significantly higher rates of fasciotomy, amputation, nerve decompression and outpatient reconstruction, with 4 cases of renal failure and 2 deaths. In spite of these differences, high and low voltage groups experienced similar rates of neuropsychiatric sequelae, limited return to work and delays in return to work. Final impairment ratings for the high and low voltage groups were 17.5% and 5.3%, respectively. Electrical injuries often incur severe morbidity despite relatively small burn size and/or low voltage. When comparing high and low voltage injuries, similarities in endpoints such as neuropsychiatric sequelae, the need for late reconstruction, and failure to return to work challenge previous notions that voltage predicts outcome.
High-field-strength element depletions in arc basalts due to mantle–magma interaction

BASALTS, basaltic andesites and andesites in subduction-related magmatic arcs are all depleted in high-field-strength elements (such as Ti, V, Zr, Nb, Hf and Ta) relative to mid-ocean-ridge basalt (MORB). Here we show that these depletions can be produced in liquids by interaction with depleted mantle periodotite, as would occur during the ascent of an arc magma through the mantle lithosphere of the overriding plate. This process involves extensive reaction between liquid, olivine, orthopyroxene and spinel. High-field-strength element depletions are produced because olivine, orthopyroxene and spinel have higher crystal/liquid distribution coefficients for these elements than for other incompatible trace elements. Liquids modified by mantle–magma interaction will also be depleted in heavy rare-earth elements, Cr and Ni, and enriched in light rare-earth and large-ion lithophile elements, relative to MORB. These characteristics are all common in mafic magmas at convergent plate margins1–7.
MidHopRoute: a multiple path routing framework for load balancing with service differentiation in wireless sensor networks

We introduce a simple but novel multiple path routing protocol to improve overall network lifetime by spread the routing load over a large number of sensor nodes and preventing congestion. We establish multiple paths between the source destination pairs and classify them based on their route length and residual energy levels. Based on the nature of queries, we assign time critical queries to shortest paths and dynamically adapt the path of non-critical queries to balance the excess load generated on shortest routes. The energy conservation results are demonstrated for both, a regular and random distribution of sensor nodes using an analytical framework as well as ns-2-based simulation.
Preventive care for the menopausal woman

In summary, menopause represents a stage in a woman's life for the primary care physician to have an important impact on health [43]. Decision-making must weigh individual risk factors for health disease, osteoporosis and breast cancer. Hormone replacement therapy remains an important issue for the postmenopausal woman [44]. More evidence is needed to define the specific health benefits and risks of HRT, particularly as it relates to the prevention of CHD. A patient centered approach using a shared decision making model is most likely to result in improved patient satisfaction and desired health outcome.
Trimming of microring resonators by photo oxidation of a plasma-polymerized organosilane cladding material

As the complexity of microphotonic devices grows, the ability to precisely trim microring resonators becomes increasingly important. Photo-oxidation trimming uses UV irradiation to oxidize a cladding layer composed of polymerized hexamethyldisilane (6M2S) deposited with plasma-enhanced chemical vapor deposition (PECVD). PECVD 6M2S has optical properties that are compatible with microring devices, and its high cross linking renders it insoluble. Photo-oxidation decreases the refractive index of PECVD 6M2S by nearly 4%, permitting large resonance shifts that are not feasible with thermal trimming techniques. Resonance shifts from single-mode, 100? ? ??m diameter Si3N4(n=2.2) rings were as large as 12.8?nm for the TE mode and 23.5?nm for the TM mode.
Lower bounds on communication overlap of networks

Abstract For an interconnection network, we introduce a graph-theoretical invariant called communication overlap—the number of paths passing through the most crowded node under the best communication arrangement in the network when each pair of nodes needs a path to communicate with each other. Further, we establish tight lower bounds for several kinds of networks. For an n -node general network with average fan-out r , we obtain Ω(n log n/ log r) as is tight lower bound of communication overlap.
Effect of a Temporal Carbon Gradient on Nitrogen and Phosphorus Dynamics and Decomposition During Mesophilic Composting

Abstract Excess carbon (C) can immobilize inorganic nitrogen (N) and phosphorus (P) when composting manure and has been used to reduce the moisture content of liquid manure so they can be composted. A mesophilic composting strategy was previously developed and shown to be an effective method to manage liquid manure without the need for excess C. The objective of this study was to determine if a temporal C gradient would sequester more N and P without the need for excess C. The experiment was conducted in bags. All treatments had arctic char manure applied at the same rate (1.28 g N), every 14 days for 112 days. The C source, ground corn stover, was applied in three batch sizes. The 1X treatment applied 70 g of corn stover every 14 days, the 4X treatment applied 280 g of corn stover at days 0 and 56, and the 8X treatment applied 560 g of corn stover once at day 0. All bags had the same amount of C and N added to them by the end of the experiment at a C∶N ratio of 30∶1. As the C to N or P ratio decreased be...
Relationship between hypothalamic-pituitary-adrenal activity and blockade of tolerance to morphine analgesia by pain: a strain comparison.

We previously reported that morphine fails to produce analgesic tolerance when administered in the presence of formalin-induced pain. The hypothalamic-pituitary-adrenal (HPA) axis is known to respond to stressful stimuli, including pain. To examine whether the blockade of tolerance by pain is related to HPA activity, we assessed the development of tolerance to morphine analgesia in an inbred strain of rats that lack typical stress-induced HPA responses (Lewis strain). Lewis rats lack typical stress-induced activation of corticotropin-releasing hormone, adrenocorticotropin hormone and glucocorticoids. Female Lewis rats were injected with morphine (20 mg/kg, i.p.) or saline for 4 consecutive days in the presence or absence of pain induced by injection of formalin into the hind-paw. The analgesic effect of morphine (5, 10 or 20 mg/kg, i.p.) was then measured in the tail-flick test 24 h after tolerance induction. Inbred female Fischer rats, which show significant stress-induced HPA activity, were used for comparison. Analgesic tolerance was produced in both strains when morphine was delivered in the absence of pain. However, the presence of pain during morphine administration prevented the development of analgesic tolerance in Fischer, but not in Lewis, rats. The differential effects of pain on the development of tolerance to morphine analgesia are suggested to be related to genetically determined differences in stress-induced HPA activity.
Search for Redshifted Annihilation Radiation from the Crab Pulsar

We present new stringent upper limits to a redshifted e± annihilation radiation line from the Crab pulsar. These upper limits are based on OSSE observations that were optimized for the 400-500 keV range. We have searched for the emission over several different phase intervals of the pulsar light curve. We find no evidence for the redshifted emission at 440 keV reported by the FIGARO team. The typical 3 σ upper limit to phase-averaged flux (i.e., the net flux from the pulsar averaged over the entire light curve) is about 2 × 10-5 photons cm-2 s-1. This value is about a factor of 4 lower than the 3 σ flux reported by the FIGARO team. This result places significant new constraints on some models in which positrons are flowing down toward the surface of the Crab pulsar.
Membership induced on manifolds by vector fields and flows

Abstract In many engineering and scientific applications, the need arises to perform differential calculations on manifolds. If such calculations involve imprecise data, methods for computing with such data must be determined. Definitions and results are given for memberships on manifolds induced by differentiation along vector fields, and by flows of vector fields with uncertain parameters. Examples are presented which illustrate the concepts.
Amyloids of Shuffled Prion Domains That Form Prions Have a Parallel In-Register β-Sheet Structure†

The [URE3] and [PSI+] prions of Saccharomyces cerevisiae are self-propagating amyloid forms of Ure2p and Sup35p, respectively. The Q/N-rich N-terminal domains of each protein are necessary and sufficient for the prion properties of these proteins, forming in each case their amyloid cores. Surprisingly, shuffling either prion domain, leaving amino acid content unchanged, does not abrogate the ability of the proteins to become prions. The discovery that the amino acid composition of a polypeptide, not the specific sequence order, determines prion capability seems contrary to the standard folding paradigm that amino acid sequence determines protein fold. The shuffleability of a prion domain further suggests that the β-sheet structure is of the parallel in-register type, and indeed, the normal Ure2 and Sup35 prion domains have such a structure. We demonstrate that two shuffled Ure2 prion domains capable of being prions form parallel in-register β-sheet structures, and our data indicate the same conclusion for...
WE‐E‐17A‐09: Modulation of the Interstitial Fluid Pressure by High Intensity Focused Ultrasound as a Way to Alter Local Fluid and Solute Movement: Insights From a Mathematical Model

Purpose: To investigate and quantify the mechanisms responsible for the increased uptake of macromolecules observed in tissue exposed to pulsed high-intensity focused ultrasound (HIFU) guided by MRI in preclinical studies. Methods: A mathematical model describing the transport of fluid and macromolecules in normal and tumor tissue is presented. The tissue is treated as a porous-permeable, isotropic and linearly elastic medium. The model calculates the changes in the interstitial fluid pressure (IFP) and the interstitial fluid velocity (IFV) immediately after HIFU exposure. T2 weighted MR images taken a few minutes after a pulsed HIFU exposure of a rabbit thigh have been employed to estimate the fluid content in the tissue. A typical HIFU exposure is about 60s long and results in a temperature increase (hottest pixel) of about 140C as measured by MRI thermometry. The IFP and the IVF are then inserted into a macroscopic solute transport equation to determine the tissue concentration profiles of macromolecules. The model equations have been solved numerically using a finite element technique. Results: In both normal and tumor tissue, the model shows that in the focal region, immediately after HIFU exposure, there is a decrease in the IFP and the IVF is directed inward. Furthermore, the solution of the solute transport equation predicts a significant accumulation in the interstitium of large macromolecule solutes such as IgG which has a molecular weight of 150,000 Da. Conclusion: Efficient delivery of therapeutic agents in targeted tissues still remains a significant challenge in medicine. HIFU guided by MRI has been shown to improve targeted drug delivery in preclinical studies. The results of our simulation suggest improved fluid convection and macromolecule distribution during the initial lowering of the IFP resulting from HIFU exposure. This model offers valuable guidance for developing strategies that employ MRI-guided HIFU for improving targeted drug delivery.
Capping of surface receptors and concomitant cortical tension are generated by conventional myosin

We have investigated the role of cytoskeletal contraction in the capping of surface proteins crosslinked by concanavalin A on mutant Dictyostelium cells lacking conventional myosin. Measurements of cellular deformability to indicate the development of cortical tension show that cells of the wild-type parental strain, AX4, stiffen early during capping and relax back towards the softer resting state as the process is completed. Mutant cells lacking myosin (mhcA-) have a lower resting-state stiffness, and fail to stiffen and to cap crosslinked proteins on binding concanavalin A. Hence conventional myosin is essential both for capping and for the concomitant increase in cell stiffness. Furthermore, depletion of cellular ATP by azide causes a 'rigor' contraction in AX4 cells which makes them stiffen and become spherical. By contrast, the mhcA- cells fail to respond in these ways. These measurements of cortical tension in non-muscle cells can thus be directly correlated with the presence of conventional myosin, demonstrating that contractile tension generated by myosin can drive both a change of cell shape and the capping of crosslinked surface receptors.
Does the adoption of IFRS affect corporate social disclosure in annual reports

Abstract In this exploratory study we investigate the impact of the implementation of IFRS on corporate social disclosures (CSD) within the context of stakeholder theory. We measure the level of CSD in annual reports using a disclosure instrument based on the United Nations Conference on Trade and Development report “Guidance on Corporate Responsibility Indicators in Annual Reports”. We find that IFRS adoption had a differential effect on CSD based on a firm's institutional setting i.e., the stakeholder–management relationship prevalent in their institutional environment. Firms in the stakeholder countries did not have a significant change in the level of CSD following the mandatory adoption of IFRS while firms from the shareholder countries experienced a significant increase over the same period resulting in shareholder countries providing an overall higher level of CSD after IFRS adoption than stakeholder countries. These findings suggest that firms' reactions to the requirements of IFRS and the stakeholder pressure to provide additional CSD are influenced by institutional environment. Further, our results provide support for the use of stakeholder theory to predict the level of CSD.
A finite-difference procedure for the exterior problem inherent in capacitance computations for VLSI interconnections

The computation of the capacitance coefficients of VLSI interconnection wires is an example of the exterior problem for Laplace's equation. However, the geometry is of a special sort in that the wires are associated within a thin horizontal strip, and the dielectric permittivity can vary two- or three-dimensionally only within that strip; outside that strip it varies only vertically. This leads to a novel method for solving the exterior problem wherein the medium outside the strip is replaced by a set of terminating capacitors connected to nodes on the upper and lower surfaces of the strip. As a result, the number of simultaneous equations and the corresponding computer times and memory requirements are substantially reduced. Several examples are given that exhibit the accuracy of the proposed method as compared to other extant methods. Corrections to the finite-difference analysis at the corners of the wires are included. >
The morphology and orientation of polyethylene in films of sub-micron thickness crystallized in contact with calcite and rubber substrates

Abstract Studies of non-isothermal crystallization morphologies were carried out in thin films of HDPE ranging in thickness of 15 nm–1.2 μm, adjacent to either (104) surfaces of calcite crystals or between thin layers of ethylene–octene rubber, both in support of the two preceding investigations of the toughening mechanism of HDPE with rubber and CaCO3 particles. Combined WAXS measurements and AFM imaging of the crystallization forms established that, for films of thickness less than 0.3 μm, lamellar crystallites preferentially grew `edge-on', in sheaf-like morphology, on the calcite or rubber interfaces with the (100) crystallographic planes of the lamellae lying parallel to the interfaces. In films thicker than 0.4 μm the characteristic banded spherulitic morphologies of twisted lamellae became dominant. These observations furnish strong support for the toughening mechanism discussed in the two companion studies (I) and (II).
Microwave spectrum and dipole moment of BH3NH3

Abstract The microwave spectrum of two isotopic species of borane monoanimoniate( 11 BH 3 NH 3 , 10 BH 3 NH 3 ) have been observed using a heated microwave absorption cell Preliminary analysis has yielded a B-N bond distance of r BN = 1.66(3) A. Analysis of the Stark effect of the J = 1—0 transition provided a dipole moment of 5.216 (17) D.
On the numerical oscillation of the direct-forcing immersed-boundary method for moving boundaries

Abstract A family of sharp-interface immersed boundary methods using the so-called “direct forcing” approach have been developed for a range of applications because of their simple formulation and relative ease in handling complex geometries. Numerical interpolations are typically adopted in these methods to approximate the flow variables at the grid points near the solid surface, which provides an implicit force in the flow so that the no-slip and no-penetration conditions are satisfied. When dealing with moving boundaries, however, these methods could be prone to numerical oscillations because the nodal points where the direct forcing is applied may change from one time step to next. Noticing that the oscillations are caused by the instantaneous change of the numerical description at the direct-forcing points, we propose a formulation that allows for a smooth transition of the numerical description at these points. This new formulation preserves the spatial accuracy of the original immersed-boundary formulation and can effectively suppress the force oscillations. In this paper, we present a specific example of such formulation in both two- and three-dimensions and validate the implementation for both fixed and moving boundaries. Finally, a full-body simulation of flapping flight is demonstrated using the proposed method.
The development of academic competence among adolescents who bully and who are bullied

Using data from the first three waves (Grades 5, 6, and 7) of the 4-H Study of Positive Youth Development, this study assessed if being a bully or being a victim accounts for an adolescent's academic competence, if selected contextual and individual variables impact an adolescent's academic competence, and if such impact differs in relation to an adolescent's bullying status. The results of random coefficient hierarchical regression analyses indicated that being a bully predicted lower grades across time, and that being a bully was more detrimental for girls than for boys. Being a bully and being a victim negatively predicted self-perceived academic competence, but these predictive effects did not change over time or differ by sex. Teacher support positively predicted grades and greater parent support and teacher support independently predicted higher self-perceive academic competence. Greater educational expectations and school engagement independently predicted higher self-reported grades, while these two predictors positively interacted in explaining self-perceived academic competence. Unexpectedly, peer support negatively predicted self-reported grades for victims, and negatively predicted self-perceived academic competence for bullies. We discuss the importance of addressing the issue of academic competence in bullying interventions, as well as the utility of capitalizing on developmental assets in promoting academic competence among adolescents who bully and who are bullied.
Recent Advances in Simulation and Optimal Design of Pressure Swing Adsorption Systems

Abstract With the growing maturity and accuracy of bed models for adsorption, increasing sophistication of pressure swing adsorption (PSA) cycles and competitive demands for high‐performance PSA separations, it is essential to develop systematic optimization strategies for the design of PSA systems. Moreover, over the past decade large‐scale simulation and optimization tools have been developed that overcome many of the computational barriers related to process optimization with detailed models. This study discusses recent progress in this area. In particular, we discuss large‐scale simulation and optimization algorithms along with their implementation on PSA systems. A case study on an O2VSA process demonstrates the effectiveness of this approach. Finally, future research directions in algorithmic development, optimal strategies for process control and operation, as well as application to more complex PSA cycles are outlined.
Deprotonation of the α-(N,N-dimethylcarbamoyl)-α-methyl-4-methoxybenzyl carbocation by alkanecarboxylate and halide ions

The product rate constant ratios kelim/kaz[N3−] for partitioning of the α-(N,N-dimethylcarbamoyl)-α-methyl-4-methoxybenzyl carbocation (4++++) in aqueous methanol between deprotonation of the α-methyl carbon to form an alkene and nucleophilic addition of azide ion increase for reactions in the presence of carboxylate and halide ions. An analysis of these data gave second-order rate constants kB for deprotonation of 4++++ by carboxylate ions which are correlated by a Bronsted coefficient of β = 0.17. The second-order rate constant for deprotonation of 4++++ by solvent water shows a 40-fold negative deviation from this correlation. Values of kelim/kaz[N3−] in 20% methanol in water increase by ≤30% as the halide ion concentration is increased from 0.0–0.80 mol dm−3 (I = 0.80, NaClO4) due either to direct deprotonation of 4++++ by the halide ion or to a specific salt effect on the partitioning of 4++++. The value for kB calculated with the assumption that this increase is due to deprotonation of 4++++ by chloride ion shows a small positive deviation from the Bronsted correlation of rate data for the reaction of carboxylate ions. However, all of these data show a satisfactory fit to a single Bronsted correlation with slope β = 0.12. These results are consistent with the conclusion that chloride ion shows a normal reactivity toward deprotonation of this α-methyl carbocation for a base of pKa ≈ −8 compared to substituted carboxylate anions, and an enhanced reactivity compared to solvent water.
Electronically Enhanced Traditional Structural Steel Beam Design Using Electronic Design Charts

Although advanced computer programs to predimension, design, and detail structural components have become so widely used and even necessary for most engineering offices, classical tools, such as design charts and tables, still find their fans in the industry. This is because many engineering tasks are more efficiently carried out if the traditional design charts and tables are used. Therefore, there is no question in whether design charts and tables should be made available to practicing engineers; the question is: should they be confined to the world of paper? Or would it be more beneficial to bring the convenience of a design chart to the engineer’s computer screen while improving its usefulness. To illustrate this concept, an MS Excel application that produces unbraced beam design charts, similar to the ones that are found in the AISC Manual of Steel Construction, was developed by the writer. This paper describes how this application was developed and gives examples of its use. Recommendations pertaini...
Actinobacillus actinomycetemcomitans and Bacteroides intermedius in human periodontitis: age relationship and mutual association.

Abstract This study examined age relationships and mutual interrelationships between cultivable Actinobacillus actinomycetemcomitans and Bacteroides intermedius in 1624 periodontitis patients, 15 to 89 years of age. Each subject contributed a pooled subgingival sample, obtained from 3 deep periodontal pockets with paper points. A. actinomycetemcomitans occurred with higher prevalence (74%) and mean recovery (7% in culture-positive patients) in patients less than 25 years old than in adult and geriatric patients (prevalence about 31%; mean recovery about 1%). The organism was detected in 85% of localized juvenile periodontitis patients. B. intermedius was recovered from 45% of the study subjects, averaged about 7% of total isolates in positive patients, and showed no predilection for any age group. As determined from predicted and observed values for A. actinomycetemcomitans and B. intermedius, occurring alone and in combination, no synergistic or antagonistic relationships between the organisms could be delineated with respect to subgingival colonization. The therapeutic implication of these findings is discussed.
Distribution of Blackbody Cavity Radiation in a Moving Frame of Reference

Blackbody cavity radiation is considered from the point of view of an observer in arbitrary uniform motion with respect to the c.m. of the radiation. It is found that the only effect of the motion is to introduce an angle-dependent effective temperature, which replaces the rest-frame temperature of the cavity. The results are applied to the question of the earth's motion through the 3\ifmmode^\circ\else\textdegree\fi{}K cosmic radiation.