cssi/SciSciGPT-SciSciNet huggingface dataset:
Distributed Machine Learning for Computational Engineering using MPI

We propose a framework for training neural networks that are coupled with partial differential equations (PDEs) in a parallel computing environment. Unlike most distributed computing frameworks for deep neural networks, our focus is to parallelize both numerical solvers and deep neural networks in forward and adjoint computations. Our parallel computing model views data communication as a node in the computational graph for numerical simulations. The advantage of our model is that data communication and computing are cleanly separated and thus provide better flexibility, modularity, and testability. We demonstrate using various large-scale problems that we can achieve substantial acceleration by using parallel solvers for PDEs in training deep neural networks that are coupled with PDEs.
Quantitative Cerebral Blood Flow with PET in the 1980s: Going with the Flow.

Nuclear medicine in general and PET imaging in particular have long provided the opportunity for quantitative measurements of human physiology in vivo. Practical methodology for these measurements came to pass in the late 1970s and early 1980s as PET scanners provided quantitative images of
A Dynamic Model of Entrepreneurial Opportunity: Integrating Kirzner’s and Mises’s Approaches to Entrepreneurial Action.

We highlight the important role that time plays in conceptualizations of opportunity in entrepreneurship research. Through two longitudinal case studies, we introduce a more dynamic understanding of opportunities than portrayed by current theorizing, which tends to emphasize “opportunity discovery.” By adopting a dynamic temporal perspective, we integrate Kirzner’s and Mises’s approaches to entrepreneurial action to generate novel insights about how entrepreneurs view opportunities as initial opportunity beliefs, how these beliefs change over time, and how these changes help inform scholarly research of opportunities. We argue that taking the role of time into consideration opens up new questions related to opportunity and the dynamics of its development.
Scanner darkly: unpopularization in the Burney Newspaper Collection

This essay explores the paradox of inaccessibility in popular archives. Often understood as democratizing, even digital databases of popular literature ironically contain a series of barriers: an e...
Optimization of permeable membrane microchannel heat sinks for additive manufacturing

Abstract The design freedom brought by additive manufacturing (AM) can be leveraged in the design of microchannel heat sinks to improve their cooling performance. The permeable membrane microchannel (PMM) heat sink geometry was inspired by the ability of powder bed AM processes to fabricate partially porous metal parts having small internal flow features on the order of the powder size. The design routes coolant through a parallel array of thin permeable membranes arranged in a single-layer-manifold configuration. The permeable membranes provide effective heat exchange surfaces and the manifold configuration yields a low flow resistance across the PMM heat sink, all incorporated in a single layer by the use of AM. Past work has introduced the PMM heat sink concept, but the optimal geometric feature sizes were not explored or identified. The n current study is first to explore design optimization of the PMM heat sink to identify target feature sizes for AM fabrication, assessment of the conditions under which the PMM geometry outperforms other standard microchannel heat sink designs, and inspection of the ability of metal 3D printing process to produce the optimal features. To this end, a reduced-order PMM heat sink model is developed, a gradient-based-multi-objective optimization is performed to identify the optimal feature sizes for different coolants (water and 48/52 water/ethylene glycol mixture) at different flow rates (100–500 mL/min), footprint areas (49–900 mm2), and channel heights (0.5–2.5 mm). The optimization results are benchmarked against an optimized straight microchannel (SMC) heat sink design. Optimized PMM designs offer up to 68% lower thermal resistance at a set pressure drop compared to optimized SMC designs. A pair of SMC and PMM heat sinks optimized for the same operating conditions are 3D printed using direct-metal-laser-sintering (DMLS) of AlSi10Mg. X-ray microtomography is used to characterize the geometry of the 3D-printed parts. The model identifies that optimal membrane gap sizes on the order of ~ 10 s μm are required for the PMM to realize performance advantages compared to SMC heat sinks under the same operating conditions. The performance is predicted to be highly sensitive to this pore size, and even though DMLS is shown to produce parts with gaps as small as 26.7 µm, morphological deviations between the design and as-printed part are shown to lead to noticeable performance differences. Albeit excellent performance potential reinforced by this work, these findings call for further AM process development to ensure reliable, as-predicted PMM heat sinks to realize this potential.
GVT-Guided Demand-Driven Scheduling in Parallel Discrete Event Simulation

The performance and scalability of Parallel Discrete Event Simulation (PDES) can be significantly impacted by temporarily inactive threads that occupy CPU resources but do no useful processing. A recent design called Demand-Driven PDES (DD-PDES) identifies such threads and de-schedules them from CPU cores to eliminate the unnecessary overhead. In this paper, we propose significant further improvements to DD-PDES. First, we introduce a new GVT (Global Virtual Time)-guided algorithm named GG-PDES to perform de-scheduling operations in a lock-free fashion and without relying on a centralized controller thread as was used previously. Second, we introduce the Dynamic CPU Affinity algorithm built on top of GG-PDES that adaptively pins simulation threads to CPU cores to achieve a balanced execution. We demonstrate that these optimizations can yield performance improvements in the range of 13% to 50% over the original DD-PDES system.
Very low-noise Al/sub 0.3/Ga/sub 0.7/As/Ga/sub 0.65/In/sub 0.35/As/GaAs single quantum-well pseudomorphic HEMTs

AlGaAs/GaInAs/GaAs pseudomorphic HEMTs with an InAs mole fraction as high as 35% in the channel has been successfully fabricated. The device exhibits a maximum extrinsic transconductance of 700 mS/mm. At 18 GHz, a minimum noise figure of 0.55 dB with 15.0 dB associated gain was measured. At 60 GHz, a minimum noise figure as low as 1.6 dB with 7.6 dB associated gain was also obtained. This is the best noise performance yet reported for GaAs-based HEMTs.
The Path to Applications

It has been possible to access a computer from a distance of several hundred yards or several thousand miles since the 1950s; however the process has not always been easy. Usually the protocols that governed the communications were not standardized, and the equipment would work only across one vendor’s product line. Access was possible but limited to highly specialized circumstances. The situation began to change with the advent of communications standards, and it will change even more with the development of public gateways and the introduction of an open network architecture. The former will enable users conveniently and easily to enter a nationwide system of interconnected communications services. The latter will enable a variety of equipment from a large number of vendors to communicate among one another through the nation’s telecommunications network.
Ultrastructural changes in human striated muscle using three methods of training.

Abstract Skeletal muscle tissue was obtained from the vastus lateralis of six normal college male students. Two biopsies were obtained prior to, and one following the training period. Two subjects performed isotonic leg extensions, two performed isometric leg extensions, and two ran up and down stadium bleachers. All training periods lasted 8 weeks. Muscle tissue was processed immediately for electron microscope examination. The following parameters were measured from micrographs of longitudinal sections: sarcomere length, sarcomere width, A band length, I band length, intracellular fat globule quantity and diameter, mitochondria length, mitochondria quantity, and Z band width. The following parameters were measured from micrographs of cross sections: myosin fiber concentration, distance between myosin filaments, myosin filament diameter, and actin filament diameters. Observations were also made on the geometric arrangement of the filaments, glycogen, and gross myofibrillar structure. Major findings were:...
Anxiety Disorders in Children and Adolescents

Anxiety disorders are one of the most common psychiatric disorders in children and adolescents, but they often go undetected or untreated. Identification and effective treatment of childhood anxiety disorders can decrease the negative impact of these disorders on academic and social functioning in youth and their persistence into adulthood.
Managing Cloud Computing risks in financial services institutions

The integration of Cloud Computing with information systems architectures continues to grow at a rapid pace due to the availability of high quality, low cost computing services and organizational efforts to improve efficiency and productivity. Enterprises are increasingly comfortable turning to the Cloud for IT solutions, where teams of dedicated, specialized experts deliver important capabilities and outcomes, instead of investing in the development of internal architectures. While data and systems security concerns remain, for many firms the economic arguments are so compelling in favor of Cloud deployments that adoption tends to proceed regardless of security and assurance worries. As a result, enterprise IT functions find themselves managing an array of risk issues in an environment of diminished transparency and with limited opportunities to directly treat observed risks. The mechanisms for managing technology risks associated with Cloud models differ from traditional approaches taken to control risk in internal architectures. This paper examines emerging threats in Cloud Computing within a financial services organization. This includes consideration of insider threats, data leakage, insecure software, and new Cloud attack patterns. The nature and characteristics of the threats are explained and the paper explores the risk treatment options chosen by the sample organization. The authors' observations are synthesized in a general model that describes Cloud Risks and Controls for financial services institutions.
Relationship of adiponectin and leptin with autoimmunity in children with new-onset type 1 diabetes: a pilot study.

Aim To explore racial differences in adiponectin, and leptin and their relationship with islet autoimmunity in children with new-onset type 1 diabetes (T1D). Methods Medical records were reviewed from a cohort of new-onset clinically diagnosed T1D subjects matched by race, age, gender, and year of diagnosis. Sera were available for 156 subjects (77 African American (AA), 79 Caucasian (C), 48% male, age of 11.1 ± 3.8 yr) and assayed for adiponectin and leptin prior to (D0), 3, 5 d, and 2–4 months (M3) after insulin therapy and islet autoantibodies to GAD, IA2, insulin, and ICA were measured at onset. Results Adiponectin levels increased significantly following insulin therapy by day 5 (D5) (D0: 13.7 ± 7.2 vs. D5: 21.3 ± 9.9 µg/mL, p < 0.0001), but no further significant increase from D5 to M3. At DO, AA had lower adiponectin levels (10.5 vs. 15.7 µg/mL, p = 0.01), were more often overweight than C (55 vs. 18%, BMI ≥ 85th‰) and fewer had positive autoantibodies (72 vs. 87%, p = 0.05). Racial differences in adipocytokines disappeared after adjustment for BMI. At M3, subjects with more number of positive autoantibodies had higher adiponectin levels (p = 0.043) and adiponectin/leptin ratio (ALR) (p = 0.01), and lower leptin levels (p = 0.016). Conclusion Adiponectin levels increased acutely with insulin therapy. Significantly lower adiponectin levels in AA were related to greater adiposity and not race. These pilot data showing those with the fewest autoantibodies had the lowest adiponectin levels, supporting the concept that insulin-resistant subjects may present with clinical T1D at earlier stages of β-cell damage.
ABIF Manager: simple reading and editing of ABIF formatted files

UNLABELLED ABIF Manager is simple application for low-level access to ABIF formatted files. Those are produced by Data Collection software based on the data, collected from capillary sequencing machine. The application shows all the data as readable text, which can be easily edited. AVAILABILITY AND IMPLEMENTATION The program source code and compiled executable is freely available at: https://sourceforge.net/projects/abifmanager/.
Kawasaki disease : A Clinical Update

The etiology of Kawasaki disease (KD) remains unknown, although a number of epidemiological and clinical observations may suggest that it is triggered by a single or more possibly multiple infectious agents, each of which can result in the clinical manifestation of the disease. Advances have been made in the management of the disease with the introduction of aspirin and IVIG that have had a significant impact on lowering the rate of coronary artery aneurysms and death from the disease. Questions remain regarding the management of those patients who fail to respond to IVIG. It appears that some patients with severe KD who are resistant to IVIG may benefit from IV pulse steroids therapy or infliximab infusion. However, a recent multi-center, randomized-controlled trial do not support for the addition of a pulsed dose of intravenous methylprednisolone to the conventional IVIG therapy for the primary treatment of KD. It still remains to be seen whether other anti-inflammatory agents such as immunosuppressive therapies, or new biologics play a role in the management of patients with KD.
Familial drusen of the optic nerve head associated with choroidal neovascular membranes

Drusen of the optic nerve head associated with a choroidal neovascular membrane have been reported, but, to the best of our knowledge this is the first report of such an occurrence in two members of the same family, a mother and son. Optic disc drusen should be included as a possible cause of choroidal neovascular membranes, especially in cases that are otherwise atypical.
The enduring allure of objective probability

Probability measures are properly considered subjective, if only as a result of the knowledge limitations of human experience. Even if objective probability can be demonstrated as an unambiguously verifiable property of the physical world, our necessarily imperfect access to such aspects of reality would necessitate the construction of subjective probability measures for examinations of human behavior. This paper will explore the distinction between subjective and purportedly objective probability in principle, and demonstrate that actual probabilities can only be subjective, at least ex ante. The paper will next examine the persistent efforts of philosophers, mathematicians, and particularly quantitatively-inclined social scientists, to construct and employ mistaken conceptions of purportedly objective probability. The neo-indeterminist interpretation of sub-atomic particle physics is addressed next, with its attempt to construct an objective-probabilistic account of reality based on the Heisenberg uncertainty principle. An explanation is suggested for the persistent allure of objective probability in the social sciences, which purports to offer a more economical and parsimonious basis for human behavior and the formation of expectations. The view that there are ontologically privileged, objectively-verifiable probabilities and expectations, will be examined and criticized. It appears to be one source of the discredited, though nonetheless widespread and persistent, belief in the efficacy and feasibility of central economic planning.
Hα Proxies for EIT Crinkles: Further Evidence for Preflare “Breakout”-Type Activity in an Ejective Solar Eruption

We present H(alpha) observations from Big Bear Solar Observatory of an eruptive flare in NOAA Active Region 8210, occurring near 22:30 UT on 1998 May 1. Previously, using the Extreme Ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO) spacecraft, we found that a pattern of transient, localized brightenings, which we call 'EIT crinkles,' appears in the neighborhood of the eruption near the time of flare onset. These EIT crinkles occur at a location in the active region well separated from the sheared core magnetic fields, which is where the most intense features of the eruption are concentrated. We also previously found that high-cadence images from the Soft X-ray Telescope (SXT) on Yohkoh indicate that soft X-ray intensity enhancements in the core begin after the start of the EIT crinkles. With the H(alpha) data, we find remote flare brightening counterparts to the EIT crinkles. Light curves as functions of time of various areas of the active region show that several of the remote flare brightenings undergo intensity increases prior to the onset of principal brightenings in the core region, consistent with our earlier findings from EIT and SXT data. These timing relationships are consistent with the eruption onset mechanism known as the breakout model, introduced by Antiochos and colleagues, which proposes that eruptions begin with reconnection at a magnetic null high above the core region. Our observations are also consistent with other proposed mechanisms that do not involve early reconnection in the core region. As a corollary, our observations are not consistent with the so-called tether-cutting models, which say that the eruption begins with reconnection in the core. The H(alpha) data further show that a filament in the core region becomes activated near the time of EIT crinkle onset, but little if any of the filament actually erupts, despite the presence of a halo coronal mass ejection (CME) associated with this event.
Transcriptional Regulation of SDHa Flavoprotein by Nuclear Respiratory Factor-1 Prevents Pseudo-hypoxia in Aerobic Cardiac Cells

Nuclear respiratory factor-1 (NRF-1) is integral to the transcriptional regulation of mitochondrial biogenesis, but its control over various respiratory genes overlaps other regulatory elements including those involved in O2 sensing. Aerobic metabolism generally suppresses hypoxia-sensitive genes, e.g. via hypoxia-inducible factor-1 (HIF-1), but mutations in Complex II-succinate dehydrogenase (SDH), a tumor suppressor, stabilize HIF-1, producing pseudo-hypoxia. In aerobic cardiomyocytes, which rely on oxidative phosphorylation, we tested the hypothesis that NRF-1 regulates Complex II expression and opposes hypoxia-inducible factor-1. NRF-1 gene silencing blocked aerobic succinate oxidation, increasing nuclear HIF-1α protein prior to the loss of Complex I function. We postulated that NRF-1 suppression either specifically decreases the expression of one or more SDH subunits and increases succinate availability to regulate HIF-1 prolyl hydroxylases, or stimulates mitochondrial reactive oxygen production, which interferes with HIF-1α degradation. Using promoter analysis, gene silencing, and chromatin immunoprecipitation, NRF-1 was found to bind to the gene promoters of two of four nuclear-encoded Complex II subunits: SDHa and SDHd, but the enzyme activity was dynamically regulated through the catalytic SDHa flavoprotein. Complex II was inactivated by SDHa silencing, which led to aerobic HIF-1α stabilization, nuclear translocation, and enhanced expression of glucose transporters and heme oxygenase-1. This was unrelated to mitochondrial ROS production, reversible by high α-ketoglutarate concentrations, and coherent with regulation of HIF-1 by succinate reported in tumor cells. These findings disclose a novel role for NRF-1 in the transcriptional control of Complex II and prevention of pseudo-hypoxic gene expression in aerobic cardiac cells.
Composition, Lipid Changes, and Sensory Evaluation of Two Sizes of Channel Catfish During Frozen Storage

The effects of size of fish on composition and of time in storage at -18°C on lipid and sensory changes for channel catfish, Ictalurus punctatus, were investigated. Dressed large (1.0 kg) fish (LF) averaged 13.2% fat, while dressed small (0.3 kg) fish (SF) averaged 10.8% fat (P < 0.05). Moisture was lower (P < 0.05) for LF (68.1 vs. 70.8%). Thiobarbituric acid (TBA) values for LF increased during the first ten months and dropped during the 12th month, while TBA values reached their highest level after the 8th month for SF. Free fatty acids did not change for LF but increased (P < 0.05) throughout storage for SF. Lipids for both sizes of fish were 25% saturated, 58% monounsaturated, and 17% polyunsaturated fatty acids. C 14:0, C 18:0, and C 18:3 acids decreased after 12 months of frozen storage. LF were rated higher (P < 0.05) in flavor for the first four months but were not rated significantly different from SF thereafter. These results indicate that although LF contained more fat, they did not oxidize an...
Russell Silver syndrome and tethered spinal cord

Case report We report a 20-year-old male with Russell Silver syndrome and tethered cord syndrome. This patient presented with non-painful scoliosis. MRI demonstrated a conus medullaris at the superior aspect of the L3 vertebral body. Axial images demonstrated no fat within the filum terminale. There was a horizontal sacrum. The patient had no cutaneous stigmata over the lumbosacral spine indicative of occult spinal dysraphism. At operation, the filum terminale was found to be quite large at approximately 5.0 mm in diameter. Grossly, the filum was found to have several large vessels both anterior and posterior to it. Following transection of the filum the distal cord was noted to withdraw cephalad indicating caudal traction.
Tectonophysics: U.S. National Report, 1967”1971, Fifteenth General Assembly, IUGG: Global Correlations

The term ‘correlations’ implies empirical comparisons of two or more different types of data. The comparisons may range in character from quite statistical to completely qualitative. For effective discussion of correlations systematic data compilations and some scheme of classification are required. For global correlations of tectonophysics the pertinent data include nearly all geophysical measurements of the solid earth. A classification scheme is constituted by regions or provinces large enough to be perceptible on a world map, say, more than 1000 km in extent in at least one dimension. We include in this summary data compilations, worldwide statistical analyses of data, attempts at regional classification, and discussions of data correlations that treat all adequately measured examples of at least one class of regions.
Recent Results from EXO-200

Abstract EXO-200 is low-background liquid Xe time-projection chamber built to detect double-beta decay of 136 Xe. Located underground at the WIPP site outside Carlsbad, NM, the detector has been running with Xe enriched to 80% since May 2011. In that time, the EXO collaboration has reported both the first observation of the 2-neutrino double-beta decay mode, a conventional second-order weak process, as well as a stringent limit on the hypothetical lepton number violating zero-neutrino mode. The collaboration has more recently improved the precision of the 2-neutrino mode decay rate to 3%, making it the most precisely-measured 2-neutrino decay to date, and continues to search for the zero-neutrino mode
Proton-Neutron Reactions and Thresholds

Threshold proton energies for neutron emission have been determined carefully for ${\mathrm{Be}}^{9}$, ${\mathrm{B}}^{11}$, ${\mathrm{C}}^{13}$, ${\mathrm{O}}^{18}$, ${\mathrm{Cl}}^{37}$, ${\mathrm{K}}^{41}$, ${\mathrm{V}}^{51}$, ${\mathrm{Mn}}^{55}$. Thin target yield data up to about 4 Mev proton energy are reported for ${\mathrm{Be}}^{9}$, ${\mathrm{B}}^{11}$, ${\mathrm{O}}^{18}$, and ${\mathrm{K}}^{41}$. A summary of all reported $p\ensuremath{-}n$ thresholds for $Z\ensuremath{\le}25$ is included. Isobaric mass differences from $p\ensuremath{-}n$ measurements and from beta-ray end points are compared. Data concerning the suitability of various $p\ensuremath{-}n$ reactions as controlled energy neutron sources are included.
Thrombin receptor activating peptides: importance of the N-terminal serine and its ionization state as judged by pH dependence, nuclear magnetic resonance spectroscopy, and cleavage by aminopeptidase M

Peptides derived from the recently identified thrombin receptor were tested for their ability to induce platelet aggregation in platelet-rich plasma. The 14 amino acid peptide identified as the new N-terminus after thrombin cleavage (T-14) and an 11 amino acid peptide (T-11) lacking the 3 C-terminal amino acids of T-14 were studied. Both induced platelet aggregation at micromolar concentrations, with T-11 about twice as potent as T-14. Induction of platelet aggregation by these two peptides showed an unusual pH dependence, being more potent at pH 7.2 than at pH 8.1; thrombin-induced aggregation showed a reverse pH dependence. Proton NMR studies of T-11 demonstrated that the chemical shift of the C-alpha proton of the N-terminal serine had a pH dependence that mirrored the aggregation potency. Acetylating the N-terminus of T-11 resulted in loss of aggregating activity, and this peptide did not show the pH-dependence change in chemical shift. The T-14 and T-11 peptides lost aggregating activity when incubated in plasma due to cleavage of the N-terminal serine by an enzyme identified as aminopeptidase M based on its pattern of inhibition and the ability of purified aminopeptidase M (EC3.4.11.2) to cleave the T-11 peptide. Endothelial cell aminopeptidase M was also able to cleave T-11. Inhibiting aminopeptidase M with amastatin enhanced aggregation induced by T-11 but not thrombin. These studies suggest that ionization of the N-terminus of the T-11 and T-14 peptides may be important in initiating platelet aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)
Control of the face fly and the horn fly with self-applicatory dust bags.

In the summer of 1967, 48 herds of cattle (1568 head) in South Carolina were utilized in an experiment to detennine the efficacy of dusts against the face fly, Musca autumnalis De Geer, and the horn fly, Haematobia irritans (L.). The herds had access to the following treatments: 1% coumaphos; 5% or 2% methoxychlor; 3% crotoxyphos (Ciodrin®); 5% toxaphene + 5% DDT + 1% lindane found to reduce(Lintox®); 2% DDT + 2% methoxychlor; 3% Crotoxyphos (Simax®); 5% coumaphos; Pmina® dust (0.075% pyrethrins, 0.2% MGK® Repellent 326 (di- n -propyl 2,5-pyridinedicarboxylate) 0.2% MGK® 264 ( N -(2-ethylhexyl)-5-norbornene-2,3-dicarboximide)); calcium carbonate inert dust; untreated check. Face fly control was erratic but generally good to excellent with the 1st 5 treatments listed above, All treatments for horn fly control were found to reduce horn fly numbers significantly below those on the untreated check herds.
Cyclic GMP regulation of a voltage-activated K channel in dissociated Enterocytes

Enterrocytes from the intestinal epithelium of the winter flounder were isolated by collagenase digestion and incubated in flounder Ringer solution. Conventional whole-cell and amphotericin-perforated whole-cell recording techniques were used to characterize the properties of a voltage-activated K current present in dissociated cells. Resting membrane potentials and series resistances were significantly lower (from −23 to − 39 mV and 29 to 13 MΩ, respectively) when amphotericin was used to achieve the whole-cell configuration. When cells were placed in flounder Ringer solution, held at −80 mV and subsequently stepped to a series of depolarizing voltages (from−70 to 0 mV), an outward current was observed that exhibited inactivation at voltages above −20 mV. This current was sensitive to holding potential and was not activated when the cells were held at −40 mV or above. When cells were bathed in symmetric K Ringer solution and the same voltage protocol was applied to the cell, inward currents were observed in response to the negative intracellular potentials. Reversal potentials at two different extracellular K concentrations were consistent with K as the currentcarrying ion. BaCl2 (2 mM) and CsCl (0.5 mM) both produced voltage-dependent blockade of the current when added to the bathing solution. Charybdotoxin (300 nM extracellular concentration) completely blocked the current. The IC50 for charybdotoxin was 50 nM. Cyclic. GMP inhibited the voltage-activated current in flounder Ringer and in symmetric K Ringer solution. The cyclic GMP analog, 8-Br cGMP, lowered the threshold for voltage activation and potentiated inactivation of the current at voltages above−40 mV. Previous studies with intact flounder epithelium showed that K recycling and net K secretion were inhibited by Ba2+ and by cGMP. We suggest that the channel responsible for the whole-cell current described in this study may be important in K recycling and secretion.
Inhibition of ATPase activity in rat synaptic plasma membranes by simultaneous exposure to metals.

Inhibition of Na+/K+-ATPase and Mg2+-ATPase activities by in vitro exposure to Cd2+, Pb2+ and Mn2+ was investigated in rat brain synaptic plasma membranes (SPMs). Cd2+ and Pb2+ produced a larger maximal inhibition of Na+/K+-ATPase than of Mg2+-ATPase activity. Metal concentrations causing 50% inhibition of Na+/K+-ATPase activity (IC50 values) were Cd2+ (0.6 microM) < Pb2+ (2.1 microM) < Mn2+ (approximately 3 mM), and the former two metals were substantially more potent in inhibiting SPM versus synaptosomal Na+/K+-ATPase. Dixon plots of SPM data indicated that equilibrium binding of metals occurs at sites causing enzyme inhibition. In addition, IC50 values for SPM K+-dependent p-nitrophenylphosphatase inhibition followed the same order and were Cd2+ (0.4 microM) < Pb2+ (1.2 microM) < Mn2+ (300 microM). Simultaneous exposure to the combinations Cd2+/Mn2+ or Pb2+/Mn2+ inhibited SPM Na+/K+-ATPase activity synergistically (i.e., greater than the sum of the metal-induced inhibitions assayed separately), while Cd2+/Pb2+ caused additive inhibition. Simultaneous exposure to Cd2+/Pb2+ antagonistically inhibited Mg2+-ATPase activity while Cd2+/Mn2+ or Pb2+/Mn2+ additively inhibited Mg2+-ATPase activity at low Mn2+ concentrations, but inhibited antagonistically at higher concentrations. The similar IC50 values for Cd2+ and Pb2+ versus Mn2+ inhibition of Na+/K+-ATPase and the pattern of inhibition/activation upon exposure to two metals simultaneously support similar modes of interaction of Cd2+ and Pb2+ with this enzyme, in agreement with their chemical reactivities.
Biometrical methods for testing dose effects of environmental stimuli in laboratory studies

In the areas of toxicology and environmental biology, the damaging effects of environmental chemicals or other stimuli on biological systems are often studied in controlled laboratory experiments. These usually involve animal and microbial systems. Data from such experiments are analysed via various statistical approaches, depending on the nature of the endpoint and aspects of the particular assay under study. Major endpoints of interest include carcinogenicity, mutagenicity, and teratogenicity. When the environmental stimulus is administered over a range of doses, it is of interest to estimate and/or test features of the dose response. In some instances, variance heterogeneity and overdispersion are present, and adjustments to the statistical methods are required. Herein, such methods for assessing dose response for the major endpoints noted above are discussed, with emphasis directed at testing for an increasing dose response.
On the near-zone inverse Doppler effect

Attention is invited to the recently discovered inverse Doppler effect which occurs in the near-zone field of an antenna emitting a continuous wave. On approaching the antenna, the received signal is blue-shifted in the far zone and then red-shifted in the near zone; and on receding from the antenna, the received signal is blue-shifted in the near zone and then red-shifted in the far zone. Calculations are presented for the ease where the antenna is a simple dipole. It is shown that this effect gives not only the vector velocity of the moving receiver but also its range, i.e., its distance from the antenna.
The Accumulation of Radioactive Iodide by the Thyroid Gland in Normal and Thyrotoxic Subjects and the Effect of Thiocyanate on Its Discharge

Interest in the effects of thiocyanate on the thyroid gland followed the observation that goiter occurred in 11 of 246 patients treated with the material for long periods of time for hypertension (Barker, 1936; Barker, Lindberg, and Wald, 1941). Both the thyroid enlargement and the accompanying manifestations of hypothyroidism were relieved by thyroid administration. It was later postulated that the action of thiocyanate in producing goiter in rats differed from that of the thiouracil derivatives (Astwood, 1943). With the former the thyroid effect was much slower to develop and was completely abolished by added iodide, which did not modify the thyroid response to compounds of the thiouracil series. From studies of the accumulation of I131 by surviving thyroid slices from sheep, Franklin, Chaikoff, and Lerner (1944) showed that the iodide-concentrating capacity was inhibited by thiocyanate. Other goitrogens did not significantly diminish the accumulation of iodide by the tissue but prevented its conversion...
Complex Formation Between α-Cyclodextrin and 4-Substituted Phenols Studied by Potentiometric and Competitive Spectrophotometric Methods

Stability constants for complex formation between α-cyclodextrin and the conjugate acid and base forms of nine phenols were measured in aqueous solution at 25°. The potentiometric method, in which the apparent acid dissociation constant of the phenol is measured as a function of cyclodextrin concentration, was supplemented by a modified version of a competitive spectrophotometric methyl orange method. For all phenols, the 1:1 stability constant for the conjugate base form (K11b,) was larger than K11a for the conjugate acid form. Finite K12bvalues were found for phenols whose 4-substituents could tolerate a positive charge by electron delocalization. Complex stability, as measured by K11a andK11b, increases with electron density and polarizability at the 4-substituent. It is concluded that the 4-substituent is the sole or predominant site of binding for both the conjugate acid and base forms of the phenols. The general result that K11b is greater than K11a for any phenol is accounted for by relative delocalization of charge in the anion and neutral species.
Non-finite complements and modality in de-na ‘allow’ in Hindi-Urdu

The meaning ‘to allow’ is expressed in Hindi-Urdu by the verb de-na ‘give’ with an oblique infinitive complement, which I argue is syntactically as well as semantically ambiguous. It has a biclausal control analysis, meaning ‘allow X to do A’, as well as an Exceptional Case Marking (ECM) complement with the meaning ‘allow A to happen’. The complements are smaller than finite CP and larger than the non-clausal causative complement, and the ECM complement is smaller than the control complement. I offer syntactic arguments for the syntactic ambiguity associated with the two meanings; where the control reading is unavailable, the ECM structure and meaning are available, sometimes by coercion from the context. The modal meaning associated with the control structure suggests that modals do not occur only in ECM/Raising constructions. The arguments are couched in minimalist syntactic terms, opening up a cross-theoretical dialogue with Butt’s (1995) analysis in Lexical-Functional Grammar (LFG) terms of the permissive as a complex predicate in argument structure.
Thermal sensitivity and activation energy of intrinsic intestinal motility in small vertebrates

1. 1.|In vitro thermal sensitivity (t.s.) of mammalian small intestine is significantly greater than t.s. of the gut of ectothermic vertebrates. In vitro contraction frequency (c.f.) of endothermic gut is an order of magnitude greater than ectothermic gut at equivalent temperatures. 2. 2.|Gut contraction t.s. is generally consistent within a given order of mammals and differs between orders. Differences in gut contraction t.s. found in the ectothermic vertebrates do not relate to taxonomic grouping. 3. 3.|An inverse relationship exists between gut c.f. and body weight in ectotherms and also probably in mammals. This relationship is seen within an individual species rather than among species. 4. 4.|Secondary intrinsic contractions occur regularly in gut of ectotherms and much less frequently in mammalian gut. In ectothermic vertebrates, these thermally sensitive gut contractions are often at higher frequency than major contractions at high gut temperatures but cease at the same minimum temperatures. 5. 5.|Unlike all other species tested, fish (bullheads, I. nebulosus) gut contractions were not rhythmic although they were thermally sensitive. 6. 6.|Activation energies for thermally sensitive gut contractions in mammals are consistent with most values rangign from 14.5–18.5 Kcal/M while activation energies for secondary contractions were much more variable with a range of 4.4–29.0 Kcal/M. 7. 7.|In laboratory mice, c.f. and c. amplitude are unaffected by pH in any biologically significant manner. Additionally, t.s. of neonatal (4–24 days old) lab mice are indicative of endotherms and are only slightly lower than adult levels 4 days after birth.
A thermodynamic analysis of estrogen regulation ofα2-adrenoceptor binding

We previously demonstrated that in vivo estradiol treatment markedly attenuates alpha 2-adrenoceptor function and coupling to G-proteins in the hypothalamus of female rats. Ligand binding studies indicated that 48 h exposure to estradiol decreases the number of alpha 2-adrenergic receptors in the agonist high affinity state. In the present studies, when [3H]RX821002 was used to label brain alpha 2-adrenoceptors, the density of binding sites significantly increased in the hypothalamus and preoptic area 48 h after estrogen treatment. Moreover, the thermodynamics of ligand binding to alpha 2-adrenergic receptors in membranes of female rat hypothalamus were modified by the same estradiol treatments that reduce alpha 2-adrenoceptor function. In hypothalamic membranes from ovariectomized control rats, antagonist (RX821002)-receptor binding was primarily entropy-driven while agonist (oxymetazoline) binding had a higher enthalpy component. In membranes from estradiol-exposed animals, the entropic contribution to both agonist and antagonist bindings was markedly increased, and the enthalpy component was reduced. Since the thermodynamic characteristics of ligand-receptor binding are strongly correlated with efficacy in activating signal transduction [36], these data raise the intriguing possibility that steroids regulate transmembrane signaling by stabilization of a receptor conformation with reduced intrinsic efficacy.
Adipose monoacylglycerol: Acyl-coenzyme a acyltransferase activity in the white-throated sparrow (Zonotrichia albicollis): Characterization and function in a migratory bird

Although migrating birds use stored triacylglycerol as their primary fuel for flight, they must retain sufficient stores of omega 6 and omega 3 fatty acids to sustain reproduction after the spring migration. Hepatic monoacylglycerol:acyl-coenzyme A acyltransferase (EC 2.3.1.22) (MGAT) activity is associated with physiological periods in which lipolysis and beta-oxidation are prominent, and it may also play a role in the selective retention of certain essential fatty acids. Therefore, we characterized MGAT activity in adipose tissue from the white-throated sparrow (Zonotrichia albicollis), a migratory bird. MGAT specific activity from adipose tissue and liver, respectively, was 22.2 +/- 7.27 and 0.79 +/- 0.35 nmol/min/mg of total particulate protein. Activity did not vary seasonally or between male and female birds. Specific activity increased 4.3-fold in the presence of 75 micrograms of phosphatidylcholine and phosphatidylserine (1:1, w/w). MGAT acylated sn-1(3)-monooleoylglycerol, sn-2-monooleylglycerol ether and sn-1(3)-monooleylglycerol ether at 7.5, 5.7 and 1.7%, respectively, of the rate observed with sn-2-monooleoylglycerol. An initial lag phase observed at low concentrations of palmitoyl-CoA was corrected by adding 2 mM MgCl2, Mg(NO3)2 or CaCl2, suggesting a requirement for divalent cations. MGAT acylated sn-2-monolinolenoylglycerol and sn-2-monolinoleoylglycerol in preference to sn-2-monooleoylglycerol. Specificity of MGAT for sn-2-monoacylglycerols and the probable enhanced affinity fo sn-2-monoacylglycerols of specific acyl chains may allow selected omega 6 and omega 3 fatty acids to be retained within the adipocyte, while nonessential fatty acids are released for beta-oxidation in flight muscles.
Trading imbalances, predictable reversals, and cross-stock price pressure

Abstract We test the implications of a multi-asset equilibrium model in which a finite number of risk-averse liquidity providers accommodate non-informational trading imbalances. These imbalances generate predictable reversals in stock returns. An imbalance in one stock also affects the prices of other stocks. The magnitude of the cross-stock price pressure depends on the correlations of the stocks’ underlying cash flows. The model implies that non-informational trading increases the volatility of stock returns. We confirm the model's implications using data from the Taiwan Stock Exchange.
Magnetic interactions in dinuclear complexes of Cr(salen)

The reaction of N,N′-ethylenebis(salicylideneiminato)diaquochromium(III) chloride, [Cr(salen)(H2O)2]Cl, with bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)diaquametal(II), M(hfa)2(H2O)2 (MCu, Ni or Co), in aqueous ethanol results in the isolation of dinuclear complexes, [Cr(salen)(solvent)2M(hfa)2]Cl. The compounds are characterized by IR and UV-Vis spectroscopy and variable temperature magnetic susceptibility. The Cr(III)Cu(II) complex is ferromagnetically coupled with J=9.7 cm−1 and the Cr(III)Ni(II) and Cr(III)Co(II) complexes are antiferromagnetically coupled with J=−11.3 and −6.7 cm−1, respectively. The analogous reactions with Fe(hfa)2 and Mn(hfa)2(H2O)2 do not yield dinuclear complexes. The former gives electron transfer products and the latter, the anion exchange product, Cr(salen)(hfa). The analogous reactions of Fe(salen)Cl with M(hfa)2 (MCu, Ni, Co, or Mn) result in the formation of Fe(salen)(hfa) (MCo, Ni or Mn) and Cu(salen) (MCu).
A nanospintronic universal quantum gate

Abstract A simple self-assembled structure has been designed to perform universal 2-qubit operations. This can act as the basic building block of a solid state nanoscale quantum information processor. The gate consists of two tri-layered quantum dots that are electrochemically synthesized within two adjacent pores in a self-assembled porous alumina film. The two outer layers are ferromagnetic metals or semiconductors while the middle layer is a semiconductor with long spin coherence time (e.g. silicon). A single electron is injected into the middle semiconductor layer and its spin encodes a qubit. A target qubit is rotated by first lifting the spin degeneracy of the corresponding electron's ground state by applying a transverse potential to induce a Rashba interaction, and then making the spin-splitting energy resonant with a globally applied AC magnetic field. The controlled dynamics of the universal 2-qubit rotation requires exploiting the exchange coupling with the nearest neighboring dot. This coupling makes the spin-splitting energy in the target dot dependent on the spin orientation in the control dot. The ferromagnetic layers act as “polarizers” and “analyzers” for spin injection and detection, thus obviating the need for initialization and also providing a means for reading a qubit.
Laminar mixing using oscillating cantilevered ionic polymer actuators

Abstract A novel active mixing device for laminar flows was developed using Nafion-based Ionic Polymer Transducers (IPTs). IPTs are a class of active materials that are thin, flexible, inexpensive, readily deployable in an aqueous medium, and offer strains up to 10% under a small ( Two cantilevered configurations of a single polymer oriented either parallel or perpendicular to the incident flow are tested utilizing a straight rectangular channel at a Reynolds number Rec = 10. The flow characteristics are quantified using planar Digital Particle Image Velocimetry (DPIV) and measurements are obtained at several locations downstream of the cantilevered IPT. Local increases in the mixing potential were measured within one channel diameter downstream of the membrane, ranging from 150% to over 375% when compared to a baseline case. Here in, the potential of IPTs as mixing elements is demonstrated. To the authors’ knowledge, the concept presented herein is the first attempt to exploit IPTs within the context of a laminar mixing device.
Designer Information - Why Visualization and Analytics Technologies Should Help Us Focus Our Minds and Not Our Senses

The current metaphors used to justify visualization research involve the specters of massive information flows and analyst overload and such demands as "connecting the dots" and searching for "nuggets". Knowledge discovery becomes the challenge, and presenting the greatest amount of information to the bewildered user, or viewer in this case, the goal. Throughout history, however, visual metaphors have first and foremost helped humans organize and digest information. Irrelevant information or conceptions have been ignored or discarded. Customized or tailored interpretations have been put forward. What do I need to know? has been more crucial than What do I need to see? Designer information, just like "designer drugs" or designer "genes", is the watchword for visualization and analytics in this 21st Century. And one of its most rigorous applications is homeland security
A new method of lodinating collagens for use in radioimmunoassay

Abstract Purified collagens from a variety of species were iodinated to a high specific activity with the N -hydroxysuccinimide ester of I 125 -labeled p -hydroxyphenyl propionic acid (Bolton-Hunter reagent). Labeling had no effect on the immunoreactivity of the collagen as determined by hemagglutination inhibition. This compound presumably acylates the abundant ϵ-amino groups of lysyl and hydroxylysyl residues in the collagen molecule. Using this method it is possible to label pepsin-extracted collagen from which the terminal nonhelical extensions containing tyrosine have been cleaved. The application of Bolton-Hunter-labeled collagens to radioimmunoassay of affinity-purfied antibodies against collagen is demonstrated.
Critical binding of an electron to a non-stationary electric dipole

Abstract The critical dipole moment for electron binding to a finite no 1-stationary electric dipole is determined. The critical moment is found to depend on the masses and separation of the dipole charges.
Capacitance-voltage characterization of pulsed plasma polymerized allylamine dielectrics for flexible polymeric field effect transistors

Polyallylamine films, deposited on Si wafers by radio frequency (RF) pulsed plasma polymerization (PPP), were employed as insulating layers of metalinsulator-semiconductor (MIS) capacitors. The insulating polymer films were deposited at plasma reactor temperatures of 25°C and 100°C. Multiple frequency capacitance-voltage (C-V) measurements indicated that an in-situ heat treatment during film deposition increased the insulator dielectric constant. The dielectric constant, calculated from the C-V data, rose from 3.03 for samples with no heat treatment to 3.55 for samples with an in-situ heat treatment. For both sample sets, the I-V data demonstrates a low leakage current value (<20 fA) up to 100 V. Capacitance-time (C-t) measurements were also used to characterize the mobile ions in the polymer that migrate over time with applied voltage. Results indicate that the polymer layers contain few electrically active defect centers and virtually no pinholes. Hysteresis in the C-V curves with differing sweep directions was more pronounced for in-situ heat-treated samples indicative of mobile charge.