cssi/SciSciGPT-SciSciNet huggingface dataset:
Prolonged, But Not Diminished, Zidovudine Absorption Induced by a High-Fat Breakfast

Study Objective. To determine the effect of a high-fat breakfast on single-dose, zidovudine (ZDV) pharmacokinetics. Design. Open-label, randomized, crossover study. Patients. Eighteen asymptomatic subjects (12 men, 6 women) infected with the human immunodeficiency virus (mean CD4 cell counts of 512 ± 178/mm3). Interventions. Subjects received single 100-mg oral doses of ZDV as follows: after an 8-hour fast (treatment A), with a high-fat breakfast (treatment B), and 3 hours after a high-fat breakfast (treatment C). Measurements and Main Results. The high-fat breakfast significantly reduced the mean (coefficient of variation) maximum plasma concentration (Cmax) from 806 (55%) ng/ml with treatment A to 341 (47%) and 424 (42%) ng/ml with treatments B and C, respectively. The time to Cmax was significantly prolonged from 0.68 (30%) hours with treatment A to 1.7 (54%) and 1.3 (42%) hours with treatments B and C, respectively. Area under the plasma ZDV concentration-time curve (AUC) was not statistically different across the study treatments. Men had significantly lower (35%) renal clearances of both ZDV and its glucuronide metabolite than women. Conclusions. When ZDV was given either with or 3 hours after a high-fat breakfast, its absorption was prolonged and Cmax was reduced relative to fasting. However, systemic exposure, as indicated by AUC, was unchanged. (Pharmacotherapy 1994;14(6):671–677)
Memory storage processes following one-trial aversive conditioning in the chick.

To investigate the kinetics of memory storage processes, transcranial subconvulsive current (SCC) was administered to large groups of chicks at various intervals following an aversive experience. The resulting retrograde amnesia data indicate that a memory trace insensitive to electroshock is formed within 45 sec of training by a mechanism that follows simple exponential kinetics. The growth of this precursor to long-term memory seems to be induced by a mnemonic process that is activated immediately upon training and which then remains at a constant intensity, perhaps serving as behaviorally manifest, short-term memory. Passage of SCC reduces the intensity of the induction process in proportion to the duration of the disrupting pulse. An investigation of the retrograde amnesia resulting from a sequence of two training-SCC sessions indicates that fractional memory traces summate together in a simple fashion that is consistent with the memory formation mechanisms described above.
The Glu-84 of the ParC subunit plays critical roles in both topoisomerase IV-quinolone and topoisomerase IV-DNA interactions.

DNA gyrase and topoisomerase IV (Topo IV) are cellular targets of quinolone antibacterial drugs. The Ser-80 and the Glu-84 of the ParC subunit have been identified as mutational hotspots for quinolone resistance. Mutant Topo IV proteins containing a quinolone resistance-conferring mutation have been constructed, and the effects of these mutations on Topo IV are assessed. Both S80L and E84K mutations abolish the ability of quinolones to trap covalent Topo IV-DNA complexes, demonstrating that both the Ser-80 and the Glu-84 of ParC are essential for Topo IV-quinolone interaction. In addition, the E84K mutation greatly reduces the catalytic activity of Topo IV. Covalent Topo IV-DNA complexes formed with Topo IV containing the E84K mutation are more stable than those formed with the wild-type protein. Interestingly, the E84P mutation confers quinolone resistance to Topo IV without affecting its catalytic activity. The E84P mutation inhibits the formation of covalent Topo IV-DNA complexes when Mg 2 + , but not Ca 2 + , is used as a cofactor. These results show that the Glu-84 plays an important role in Topo IV-DNA interaction. Thus, the Glu-84 of ParC is critical for the interactions of Topo IV with both the quinolone drug and the DNA in topoisomerase-quinolone-DNA ternary complexes.
Optimization of an Occulter-Based Extrasolar-Planet-Imaging Mission

Anovel approach to extrasolar-planet imaging uses a pair of satellites: a telescope and an occulter, where the latter is placed in the line of sight between the telescope and the star system to be imaged in order to enhance the telescope’s imaging capability. The optimal configuration of this satellite formation around sun–Earth L2 halo orbits is studied. Trajectory optimization of the occultermotion between imaging sessions of different stars is performed using a range of different criteria and methods. Thus, the global optimization problem is transformed into a time-dependent traveling salesman problem. The time-dependent traveling salesman problem is augmentedwith various constraints that arrive from the mission, and this problem is solved by employing simulated annealing and branching algorithms. For a concrete understanding of the feasibility of themission, the performance of an example spacecraft, the Small Missions for Advanced Research in Technology (SMART-1), is analyzed.
MAPK (ERK2) kinase—a key target for NSAIDs-induced inhibition of gastric cancer cell proliferation and growth

Limited clinical and experimental studies indicate that nonsteroidal anti-inflammatory drugs (NSAIDs) may inhibit gastric cancer growth. However, the mechanisms involved are not completely understood and cannot be explained by COX-2 inhibition alone. MAPK signaling pathway is essential for cell proliferation, but the effect of NSAIDs on MAPK activity and phosphorylation in gastric cancer has never been studied. Since increased and unregulated cell proliferation and reduced cell apoptosis are important features of cancer growth, we studied whether NS-398, a selective COX-2 inhibitor and/or indomethacin (IND), a non-selective NSAID: 1) inhibit gastric cancer cell proliferation, 2) whether this inhibition is mediated via MAPK (ERK2), and 3) whether NSAIDs enhance apoptosis in gastric cancer cells. Human gastric epithelial cells (MKN28) derived from gastric tubular adenocarcinoma were cultured and treated with either vehicle, IND (0.25–0.5mM) or NS-398 (50–100μM) for 6, 16, 24 and 48h. Studies: 1) Cellular proliferation was determined by 3H-thymidine uptake. 2) MAPK activity was measured by incorporation of radiolabeled phosphate into myelin basic protein. 3) Apoptosis was evaluated using TUNEL assay. IND and NS-398 significantly inhibited the proliferation of MKN28 cells at 24h by 3.5 – 5 fold (p 53% inhibition, NS-398, 100μM >72% inhibition; all p<0.05. Both IND and NS-398 significantly increased apoptotic index. In conclusion, IND and NS-398 significantly inhibit proliferation and growth of human gastric cancer cell line MKN28. This effect is mediated by NSAID-induced inhibition of MAPK (ERK2) kinase signaling pathway, essential for cell proliferation. NSAIDs also increase apoptosis in MKN28 cells. In addition to inhibiting cyclooxygenase, NSAIDs inhibit phosphorylating enzymes - kinases essential for signaling cell proliferation.
Density Functional Theory Calculations for Simple Oxametallacycles: Trends across the Periodic Table

Density functional theory (DFT) was used to calculate the structures of simple oxametallacycles, generated by inserting one or two metal atoms in the C−O bond of the ethylene oxide molecule, for 14 different transition metals (groups VIIIa−c, Ib, IIb). The calculated energetic stability of these complexes generally decreases from left to right of the periodic table and from top to bottom of each group of metals. Silver, which is unique among these metals in catalyzing selective ethylene epoxidation, gives an oxametallacycle intermediate that is more stable than ethylene oxide by ca. 10 kcal/mol. The modest stability of this intermediate may explain the formation of the less energetically favorable C2H4O isomer, ethylene oxide, on silver catalysts. The calculated relative stabilities of oxametallacycles versus acetaldehyde on various metal surfaces are consistent with previous experimental observations that an oxametallacycle is the preferred intermediate in ethanol decarbonylation on the Rh(111) surface, ...
Polynucleotide ligase activity of eukaryotic topoisomerase I.

Introduction of a single ribonucleoside immediately 5' of the scissile phosphate of a duplex DNA substrate converts eukaryotic topoisomerase I into an endoribonuclease. Here, I demonstrate that the RNase reaction is reversible. Vaccinia topoisomerase can ligate 2', 3'-cyclic phosphate and 5'-hydroxyl termini annealed to a bridging template strand. Remarkably, the ligase activity of topoisomerase does not require the active site tyrosine, implying that strand joining can occur via direct attack of the 5' hydroxyl on the cyclic phosphate without a covalent intermediate. Ligation does require other catalytic side chains on the enzyme. These findings underscore how a common ancestral mechanism of phosphoryl and nucleotidyl transfer can be harnessed to perform seemingly diverse tasks through subtle changes at the active site.
Overexpression of ptc1 inhibits induction of Shh target genes and prevents normal patterning in the neural tube.

Patched (Ptc) is a human tumor suppressor protein and a candidate receptor for Hedgehog (Hh) proteins, which regulate growth and patterning in embryos. Ptc represses expression of Hh target genes such as Gli1 and ptc1 itself. Localized secretion of Hh appears to induce transcription of target genes in specific patterns by binding to Ptc and preventing it from functioning in recipient cells. People who are heterozygous for PTC1 exhibit a range of developmental defects, suggesting that some genes are inappropriately expressed when there is not enough Ptc protein. To test the idea that a balance between Hh and Ptc activities is essential for normal development, we overexpressed Ptc in the neural tube. We find that excess Ptc is sufficient to inhibit expression of Gli1 and ptc1, suggesting that Sonic hedgehog (Shh) cannot signal effectively. This leads to partial dorsalization of the neural tube and a wide spectrum of neural defects, ranging from embryonic lethality to hydrocephaly.
The Propagation of Radio Waves: The Theory of Radio Waves of Low Power in the Ionosphere and Magnetosphere

This is a most welcome addition to the library of books on radio waves in the ionosphere. The standard references in the western world are all quite old, although they are still remarkably useful: S.K. Mitra's The Upper Atmosphere (Asiatic Society, Calcutta, India, 1952), K.G. Budden's Radio Waves in the Ionosphere (Cambridge University Press, London, 1961), and K. Davies' Ionospheric Radio Waves (Blaisdell, Waltham, Mass., 1969). In the eastern world, Y.L. Alpert and V.L. Ginzburg are the authorities, and both now have volumes in English: Alpert's The Near Earth and Interplanetary Plasmas (volumes 1 and 2, Cambridge University Press, London, 1983) and Ginzburg's The Propagation of Electromagnetic Waves in Plasmas (Pergamon, New York, 1970).
Electrostatics in the Ribosomal Tunnel Modulate Chain Elongation Rates

Electrostatic potentials along the ribosomal exit tunnel are nonuniform and negative. The significance of electrostatics in the tunnel remains relatively uninvestigated, yet they are likely to play a role in translation and secondary folding of nascent peptides. To probe the role of nascent peptide charges in ribosome function, we used a molecular tape measure that was engineered to contain different numbers of charged amino acids localized to known regions of the tunnel and measured chain elongation rates. Positively charged arginine or lysine sequences produce transient arrest (pausing) before the nascent peptide is fully elongated. The rate of conversion from transiently arrested to full-length nascent peptide is faster for peptides containing neutral or negatively charged residues than for those containing positively charged residues. We provide experimental evidence that extraribosomal mechanisms do not account for this charge-specific pausing. We conclude that pausing is due to charge-specific interactions between the tunnel and the nascent peptide.
Ovid, Metamorphoses 1.2

The purpose of this paper is, first, to demonstrate to future editors of the Metamorphoses , whether conservative or sceptical, just how improbable is the reading of the majority of MSS, illas , and how strong are the claims of the variant ilia , first recommended by P.Lejay in 1894 and vigorously championed by E.J.Kenney in 1976; and, second, to suggest an interpretation of this reading that is open to fewer objections than the one proposed by Kenney.I have given above the beginning of Ovid's longest poem as it ought to stand in all modern editions and as it stands in fact in only one, the French school edition of selections edited by Lejay in 1894: ‘Gods, on my undertakings (for you have changed them as well) breathe your favour.’ To be sure, all of Ovid's MSS read illas in line 2, and ilia is attested only as a variant in two of them.But majorities, in textual as in other matters, are frequently wrong.Even before the minority report of the Urbinas had been heard, Lejay adopted ilia , av.1.in the Erfordensis.1
Molecular Links between Centrosome and Midbody

The terminal step in cytokinesis that severs a cell in two—abscission—is poorly understood. In Developmental Cell, Fabbro et al. (2005) identify a centrosome protein whose multiple phosphorylations regulate its movement from centrosome to midbody and completion of abscission.
Growth, chemical interaction, and Schottky-barrier formation of column-III metal overlayers on InP(110).

We report soft-x-ray valence-band and core-level photoemission studies of the growth and chemical reaction of column-III (Al, Ga, In, and Tl) overlayers on cleaved InP(110). We find that the deposition of submonolayer coverages of these metals leaves the valence-band spectra devoid of any structure other than that characteristic of the clean InP(110) surface. Strong bonding between the Al, Ga, or In adatoms relative to the bond between the adatoms and the substrate leads to cluster formation on the surface. Growth of a uniform overlayer cannot, however, be excluded for Tl. Core-level spectra of substrate atoms and overlayer atoms for Al and Ga interfaces clearly indicate a room-temperature exchange reaction accompanying the islanding of nonreacted metal. No indications of such a reaction are found for In and Tl. The trends of the reaction are in agreement with predictions of bulk thermodynamics. The overall trend in the growth mode agrees with the theoretical predictions of Zunger.
Childhood-onset lupus with clinical neurocognitive dysfunction shows lower streamline density and pairwise connectivity on diffusion tensor imaging

ObjectivesThe objective of this report is to use diffusion-tensor imaging (DTI) for investigating white-matter connectivity changes associated with neurocognitive dysfunction in childhood-onset lupus (cSLE-NCD) as measured by formal neuropsychological testing.MethodsDTI was performed in six individuals with (cSLE-NCD) and nine without neurocognitive dysfunction (cSLE-noNCD) as well as 14 healthy controls. Presence of neurocognitive deficits was identified by formal neuropsychological testing. The brain was divided into 116 regions, and pairwise connectivity (defined as the number of streamlines with an endpoint in each of those regions) and streamline density (defined as the number of streamlines passing through a region regardless of endpoints) were evaluated. Group comparisons were made for regional and global measures of streamline density and pairwise connectivity.ResultsA significant decrease in global streamline density was observed in the cSLE-NCD vs. control group (1189 vs. 1305 p = 0.002) and vs....
Developmental Continuity in Teleo-Functional Explanation: Reasoning about Nature Among Romanian Romani Adults

Teleo-functional explanations account for objects in terms of purpose, helping us understand objects such as pencils (for writing) and body parts such as ears (for hearing). Western-educated adults restrict teleo-functional attributions to artifact, biological, and behavioral phenomena, considering such explanations less appropriate for nonliving natural entities. In contrast, children extend explanations of purpose to the nonliving natural domain. This cross-cultural study explores whether apparent restrictions in“promiscuous teleology” occur as a function of age and development, generally, or scientific literacy, more specifically. Using methodology from Kelemen (1999b), two groups of adult Romanian Roma from the same community selected explanations for properties of biological and nonbiological natural entities; one group had little or no science training, the other was formally schooled. Compared to their schooled peers and to Western-educated American adults, nonschooled Romani adults were more likel...
Memory consolidation: brain region and neurotransmitter specificity.

Abstract Post-trial injections of norepinephrine, but not dopamine, into the amygdala produce a long-term retention deficit (amnesia) for a l-trial footshock experience in rats. In contrast, post-trial injections of dopamine, but not norepinephrine, into the caudate produce long-term facilitation. The data provide evidence for brain region-neurotransmitter specificity which supports a multiple component hypothesis.
Altruism, evolutionary psychology, and learning

Rachlin's substantive points about the relationship between altruism and self-control are obscured by simplistic and outdated portrayals of evolutionary psychology in relation to learning theory.
Comparing D-branes and black holes with 0- and 6-brane charges

We consider configurations of D6-branes with a D0-brane charge given by recent work of Taylor and compute interaction potentials with various D-brane probes using a 1-loop open string calculation. These results are compared to a supergravity calculation using the solution given by Sheinblatt of an extremal black hole carrying 0-brane and 6-brane charges. {copyright} {ital 1997} {ital The American Physical Society}
A COMPUTATIONALLY EFFICIENT VELOCITY‐SPACE TRANSPORT MODEL FOR DEVICE SIMULATION

An improved velocity‐space carrier transport model is presented, based on a direct solution of the Boltzmann Transport Equation. This model attempts to achieve the computational efficiency required for device simulation, while still solving for the distribution function itself. This preserves critical fine structure effects due a non‐ideal band structure and forward scattering mechanisms. The model includes a numerically efficient representation of three dimensional k‐space formulated around a 1D velocity‐space variable, and the particle energy. The number of empirical parameters in the model is reduced to a single constant per scattering mechanism. A physically intuitive solution algorithm is developed which repeatedly shifts and shapes the estimate of the distribution until convergence. Results are presented for the steady‐state homogeneous case in silicon and GaAs, which are of comparable computational cost as drift‐diffusion simulations.
Curses, Oaths, Ordeals and Trials of Animals

To the outsider, a foreign legal system may at times appear irrational, with a belief in the efficacy, usually with supernatural assistance, of curses, oaths and ordeals, and that animals may properly be punished, even restrained from anti-human behaviour, after a criminal trial. But caution must be exercised. There may be little real belief that the deity will intervene—for instance, that the ordeal will reveal guilt or innocence. Rather, the society may be faced with an intolerable problem, with no reasonable solution, and the participants may resort to extraordinary legal measures as a “Last Best Chance”, or “The Second Best”. Something has to be done, even if nothing satisfactory can be done. This dodge reveals itself by its use being restricted to a few situations. Thus in ancient Hebrew law ritual legal cursing is not used as a punishment, and in fact is found only where a husband accuses his wife of adultery but has not the very strict evidence required by law. The medieval ordeal was normally used...
Radioligand-dependent properties of the Ah receptor from rat and mouse hepatic cytosol

A comparison of the molecular properties of the rat and mouse hepatic cytosolic Ah receptor complex was determined using [3H]-2,3,7,8-tetrachloro-p-dioxin (TCDD) and [3H]-2,3,7,8-tetrachlorodibenzofuran (TCDF) as radioligands. In low salt buffer, the sedimentation coefficient, Stokes radii, relative molecular masses, frictional ratios, axial ratios and gel permeation chromatographic properties of the rat receptor complexes were ligand-independent. In contrast, there were several ligand-dependent differences in the mouse Ah receptor complexes formed after incubation in low salt buffer and these included the following: sucrose density gradient analysis of the [3]-2,3,7,8-TCDF receptor complex gave a 9.5 S specifically bound peak and a 2.6 S non-specifically bound peak whereas the corresponding [3H]-2,3,7,8-TCDD receptor complex gave a single 9.6 S specifically bound peak: sucrose density gradient analysis of the two major peaks eluted from Sephacryl S-300 column after chromatographic separation of the [3H]-2,3,7,8-TCDF receptor complex gave two specifically-bound peaks at 9.2 and 5.1 S. The molecular properties of the rat hepatic cytosolic receptor complexes incubated in high salt (0.4 M KCl) buffer were ligand-independent with one exception, namely the significant difference in the sedimentation coefficient of the specifically bound disaggregated [3H]-2,3,7,8-TCDD receptor complex (6.8 S) and the corresponding [3H]-2,3,7,8-TCDF receptor complex (5.0 S). The major ligand-dependent differences in the mouse receptor complexes incubated in high salt (0.4 M) were associated with the sedimentation coefficients of the complexes derived after direct incubation and after gel permeation chromatography. For example, both ligands gave two specifically bound complexes after chromatography on Sephacryl S-300 column and centrifugation of these fractions gave both the ∼9S and ∼5S peaks: this indicated that there was equilibration between the aggregated and disaggregated receptor complexes. The behavior of the [3H]-2,3,7,8-TCDF mouse receptor complex was similar after incubation in low or high salt buffer except that sucrose density gradient analysis of the gel permeation chromatographic fraction gave an additional specifically-bound peak which sedimented at 7.2 S. These studies demonstrate that the molecular properties of the Ah receptor are dependent on the source of the cytosolic receptor preparation, the ionic strength of the incubation media and the structure of the radioligand.
Reharvesting of Saphenous Vein Arterial Bypasses— Two Case Reports

Patients who require bypass grafts to the distal vessels of the lower extremity represent a significant problem if autogenous saphenous vein is not available, since saphenous vein has a higher patency rate than any other prosthetic mate rial for distal bypasses. Presented here are two case reports of reharvesting saphenous vein that has been previously used in femoropopliteal bypasses. Composite grafts were then constructed with polytetraflouroethylene (PTFE) so the portion of the bypass going below the knee was still saphenous vein graft.
Practical aspects of formulation and solution of moving mesh partial differential equations

Moving mesh partial differential equations (MMPDEs) are used in the MMPDE moving mesh method to generate adaptive moving meshes for the numerical solution of time dependent problems. How MMPDEs are formulated and solved is crucial to the efficiency and robustness of the method. In this paper, several practical aspects of formulating and solving MMPDEs are studied. They include spatial balance, scaling invariance, effective control of mesh concentration, bounds on time steps, multiple sub-steps, and two-level mesh movement. Numerical results are also given. c ∞ 2001 Academic Press
20.4: Compact RGB Laser Module for Embedded Laser Projection

We report on a study of a miniaturized laser module suitable for embedded projection with the flying spot approach. The module comprises RGB lasers, a closely connected laser driver ASIC and optical components. Key aspects of our studies are light output and color mixing stability as well as transient performance of the module.
Oxidation Dynamics of a Chain of Aluminum Nanoparticles

Multimillion-atom molecular dynamics simulations are used to investigate burning behavior of a chain of three alumina-coated aluminum nanoparticles (ANPs), where particles one and three are heated above the melting temperature of pure aluminum. The mode and mechanism behind the heat and mass transfer from the hot ANPs (particles one and three) to the middle, cold ANP (particle two) are studied. The hot nanoparticles oxidize first, after which hot Al atoms penetrate into the cold nanoparticle. It is also found that due to the penetration of hot Al atoms, the cold nanoparticle oxidizes at a faster rate than in the initially heated nanoparticles. The calculated speed of penetration is found to be 54 m/s, which is within the range of experimentally measured flame propagation rates. As the atoms penetrate into the central ANP, they maintain their relative positions. The atoms from the shell of the central ANP form the first layer, which is followed by the atoms from the shell of the outer ANP making the second layer and lastly the atoms from the core of the outer ANPs form the third layer. In addition to heating the central ANP by convection, the ejected hot Al atoms from the outer ANPs initiate exothermic oxidation reactions inside the central ANP, leading to further heating within the central ANP. During 1 ns, all three ANPs fuse together, forming a single ellipsoidal aggregate.
Structure and magnetic properties of ferromagnetic nanowires in self-assembled arrays

Static and dynamic aspects of the magnetization reversal in nanowire arrays are investigated. The arrays have been produced by electrodeposition of ferromagnetic metals (Fe, Co, and Ni) into porous anodic alumina templates, with diameters as small as 5 nm. The crystal structures of the nanowires are bcc (Fe) and fcc (Ni) and a mixture of fcc and hcp (Co), with grain sizes of a few nanometers. Magnetic properties as a function of temperature are investigated. The temperature dependence of coercivity can be understood in terms of thermal activation over an energy barrier with a $\frac{3}{2}$-power dependence on the field. Coercivity as a function of diameter reveals a change of the magnetization reversal mechanism from localized quasicoherent nucleation for small diameters to a localized curlinglike nucleation as the diameter exceeds a critical value determined by the exchange length. The quasicoherent limit is described by a model that yields explicitly real-structure-dependent expressions for coercivity, localization length, and activation volume.
Inhibition of transketolase and transaldolase of the human hemolyzate by multivalent anions

Abstract Orthophosphate and sulfate at a concentration of 0.1 M and diphosphoglycerate at a concentration of 0.01 M inhibit transaldolase as well as transketolase activity in the human hemolysate. The inhibition of transketolase decreases with the increase in the concentration of ribose 5-phosphate and the two ketopentose 5-phosphates in the hemolyzate. A possible mechanism of this inhibitory effect is discussed.
Regulation of pro-adrenocorticotropin-endorphin synthesis and secretion in cultured neonatal rat anterior pituitary.

Previous work demonstrated that newborn rat anterior pituitary corticotropes display processing patterns for pro-ACTH/endorphin that are different from the adult. The synthesis and release of β-endorphinrelated peptides was examined in dispersed cell and explant cultures of newborn anterior pituitary to investigate corticotrope development further. The temporal pattern of pro-ACTH/endorphin processing differed significantly from adult rat melanotropes and AtT-20 cells. While pro-ACTH/endorphin processing begins within 30min of synthesis in adult melanotropes and AtT-20 cells, pulse-labeling of newborn corticotropes in culture indicated that pro-ACTH/endorphin remained uncleaved for at least 90 min after synthesis. With further incubation, there was a decrease in radioactivity associated with the precursor and an equivalent rise in the radioactivity associated with β-endorphin and β-lipotropin. However, unprocessed precursor still remained in the cultured newborn anterior pituitary cells after a 25-h chase...
Neuromuscular patterns of stereotypic hindlimb behaviors in the first two postnatal months. II. Stepping in spinal kittens.

From birth to postnatal day 60, neuromuscular patterns for airstepping and treadmill stepping were assessed in kittens spinalized (T12) at birth (Day-1) or at the end of the second postnatal week (Day-14). Within 72 h after spinalization, all kittens displayed stepping motions, but exteroceptive facilitation (e.g. tail pinch) was required to initiate and sustain both behaviors. In Day-14 spinal kittens, the hindlimbs spontaneously and alternately airstepped, but in Day-1 spinal kittens exteroceptive stimulation was usually necessary to evoke airstepping, and the hindlimbs stepped synchronously. Kittens in both groups developed atypical neuromuscular patterns; flexor bursts were nearly twice as long in duration as extensor bursts. Development of bipedal treadmill stepping was similar for Day-1 and Day-14 spinal kittens, but differed from that for normal kittens. Tested at the same belt speeds, stepping was more easily elicited in spinal kittens, bouts of repetitive stepping were longer, and cycle periods were shorter than in normal kittens until postnatal week 6. Spinal kittens, however, seldom exhibited adequate weight support during hindlimbs stepping, and the neuromuscular patterns associated with bipedal stepping were atypical. For spinal kittens, the relationship between the extensor burst duration and the cycle period was reduced substantially, and flexor activity was initiated earlier in the step cycle and was longer in duration than that for normal kittens. These atypical intralimb synergies may have been the consequence of altered lumbosacral circuits produced by the spinal transection. It is also possible that these spinal circuits, lacking rostral input, were particularly susceptible to abnormal motion-dependent feedback resulting from reduced hindlimb weight support.
A framework for the development of multiagent architectures

A high-performance software system provides the necessary facilities to experiment with various multiagent-coordination choices at different abstraction levels. The authors discuss these abstractions and empirically evaluate their usefulness for the construction of distributed systems.
Pavlovian conditioning and human fear: An expectancy model

Behavior therapists have explained phobias in terms of the contiguity principle of Pavlovian conditoning, which holds that conditioning results from CS-US temporal pairings. This principle provides a problematic account of phobias because CS-US pairings are neither necessary nor sufficient for fear acquisition in humans and because it cannot explain the Kamin blocking effect, conditioned inhibition, cessation conditioning, and overexpectedness in infrahuman conditioning. An expectancy model is proposed as an alternative to the contiguity model. The expectancy model holds that what is learned in Pavlovian conditioning is an expectation regarding the occurrence or nonoccurrence of the US. The mediating expectacy process can become an elicitor of CRs, verbal reports of CS-US relations (awareness), and instrumental behavior. The Wagner-Rescorla formulas for describing the learning of CRs in Pavlovian conditioning are assumed to have important implications for stimulus expectancy learning. A four-process model of phobias is proposed: (1) danger expectancy, (2) anxiety expectancy, (3) negative reinforcement of avoidance, and (4) positive (self-) reinforcement of avoidance. Implications are discussed for CS exposure therapies, placebos, self-efficacy, and aversion-relief therapy.
High hip center in revision arthroplasty

What is the effect of superior placement of the acetabulum in complex hip reconstruction? Twenty-two patients (23 cases) had revision hip arthroplasty with superiorly placed porous-coated components without bone-grafts. Cemented femoral components were used in 21 cases and ingrowth components in 2. The average vertical height (corrected for magnification) was 36.8 mm from the interteardrop line, compared to a contralateral normal height of 12.1 mm. Three patients were deceased. The remaining 19 patients (20 hips) had a minimum 2-year follow-up period (average, 35 months). Fourteen hips had two or more previous surgeries. Seven acetabular components had thin (< 1 mm), nonprogressive, incomplete radiolucent lines. One acetabulum had a complete 1 mm radiolucent line in an asymptomatic patient. The remaining 12 acetabular components had no evidence of radiolucent lines and none of the acetabular components migrated. One hip with a cemented femoral component had evidence of possible loosening. Two cemented femoral components had evidence of definite loosening, one with minimal clinical symptoms and the other was revised to a long stem at 14 months after revision. Of the two ingrown femoral components, one had initial subsidence of 1.5 cm and both had thigh pain. All other patients had improved from their preoperative status; however, 4 of 20 hips had moderate to severe pain. Superior cup position did not result in concomitant lateral position. With a short-term follow-up period however, vertical displacement alone resulted in high loosening rates, with 25% for the femur and 5% for the acetabulum.
Poster: characterizing the impact of memory-access techniques on AMD fusion

The cost of data transfers over PCI-Express often limits application performance on traditional discrete GPUs. To address this, AMD Fusion introduces a novel architecture that fuses the CPU and GPU onto a single die and connects the two with a high-performance memory controller. This architecture features a shared memory space between CPU and GPU, enabling several new memory access techniques that are not available on discrete architectures. For instance, a kernel running on the GPU can now directly access a host memory buffer and vice versa. As an initial step towards understanding the implications of the fused CPU+GPU architecture to heterogeneous computing, we characterize the performance impact of various memory-access techniques on applications running on an AMD Fusion platform (i.e., Llano A8-3850). The experimental results show that AMD Fusion can outperform a discrete GPU of the same performance class by as much as 4-fold for a memory-bound kernel.
Chaos in counter-rotating Couette flow

Abstract A quasi-periodic transition to chaos has been observed experimentally in counter-rotating Taylor-Couette flow. This scenario occurs when a circular path is followed around a multicritical point in parameter space. (The multicritical point results from the nonlinear interaction between azimuthal wavenumbers m = 2 and m = 3.) To complement the experiments, the reduced amplitude equations that describe this mode interaction have been solved numerically. The numerical solutions follow a transition to chaos similar to the one observed experimentally. Both experimental and numerical chaotic flows are characterized by broadband spectra, low fractal dimension and a positive largest Lyapunov exponent. This result indicates that the chaos observed experimentally might be due to the mode interaction, and that the mathematical model might be appropriate to describe chaotic behavior in real flows.
TSH suppression in the management of autonomously functioning thyroid lesions.

Solitary autonomously functioning thyroid lesions (AFTL) are discrete hyperfunctioning nodules whose growth and function do not appear to be dependent on thyroid-stimulating hormone (TSH). Although they gradually increase in size and function over years, rarely do they progress to produce hyperthyroidism. This article presents the thesis that this “self-limiting feature” is related to their growth and function being modulated by levels of TSH. Thyroid membranes from autonomously functioning thyroid lesions were examined in 6 patients. A nonlinear Scatchard plot was obtained with the hyperfunctioning thyroid lesion demonstrating high-affinity, low-capacity TSH receptor components. These exhibited a binding capacity ranging from 7 to 600 fmol/mg protein in patients with suppressed TSH levels to 1,450 in a euthyroid patient. All lesions exhibited basal adenylate cyclase activity which was stimulated 2–3-fold by Bovine TSH. A review of the natural history of the lesion demonstrates a decremental increase in size and function with time. In 9 patients receiving thyroid hormone as suppressive therapy observed over a period of 4–14 years, the lesions partially regressed in 4 and did not progress in 5. This concept of growth and function of AFTL being modulated by TSH levels has therapeutic implications when such nodules are identified early in the course of their development. At this time, TSH suppression may be inhibitory to increase in nodule size and secretion of thyroid hormones.
Lithographically defined carbon growth templates for ELOG of GaN

Abstract We report the initial use of lithographically defined carbon growth templates for use as an epitaxial lateral overgrowth (ELOG) mask for metalorganic chemical vapor deposition (MOCVD) heteroepitaxial GaN on sapphire. Interferometric lithography is used to define high aspect ratio structures in SU-8, which are then pyrolyzed in a reducing atmosphere up to 1200 °C. The resist structures convert to amorphous carbon, shrinking 80% in the vertical direction and 53% in the horizontal direction, but maintain their pattern geometry and adhesion to the substrate. These templates are capable of surviving GaN nucleation layer growth temperatures (∼530 °C), GaN crystal growth and high-temperature annealing up to 1050 °C. This new approach to ELOG offers several advantages, requiring fewer processing steps, and favorable selectivity tendencies as well as the capability to create growth masks which are difficult or impossible to fabricate using a top–down etching approach.
The Historic Bases of Private International Law

INTEGRATION AND DIVERSITY are the two dominant features of modern culture that in conjunction give rise to confficts of laws. The intensive division of labor introduced by the industrial revolution, necessitates complex, localized regulation of specialized services. The operation of the correspondingly diversified economy depends upon commerce, upon exchange of goods and diffusion of ideas through the constantly improved means of transport and communication provided by scientific invention. Paradoxically, the function of the legal order therefore is to co-ordinate the activities that constitute civilization on a common basis of security and, in so doing, to satisfy the needs of each local or specialized activity. Moreover, the legal order itself is decentralized among a plurality of sovereign or autonomous authorities, asserting jurisdiction each within a defined territory over activities that concern their respective subjects. As the pretensions of the corresponding local laws to control international or interstate commerce thus inevitably overlap, the legal order also involves integration of the diversity of the laws of which it is composed. The mode in which this adjustment is or should be effected is the concern of confficts law. The specific method to integrate the existing diversity of laws, employed in this branch of law, is to apply or refer to foreign law in dealing with foreign cases. This, as will appear, is a sophisticated technique that took centuries to develop; it assumes a certain cosmopolitan respect, or at least tolerance, for foreign conceptions of justice. In early times, when the legal order was intimately connected with actual or supposed kinship groups and was part of the peculiar religious and social structure of the particular community, law was inalienably personal. It was inconceivable, for example, that the ius civile, the common law of the Roman citizenry, should be available to a peregrine in Rome or, vice versa, that
Nonradiative transfer of momentum from an electromagnetic wave to a charged particle.

A plane-wave pulse passing by a charged particle can leave the particle with momentum and energy different from that before the arrival of the pulse. The mechanism for transmitting this momentum and energy is nonradiative and involves the interference of the electromagnetic fields of the particle and wave. A focused pulse (with a finite beam waist) cannot transfer momentum and energy in this way. However, if a charged particle is mechanically restrained and then released inside a focused pulse, momentum can be transferred nonradiatively to the particle through the mechanical restraining force. We use these considerations to further clarify the source of the large drift momentum that photoelectrons have been observed to acquire in recent experiments on atomic ionization by strong low-frequency fields, we discuss the energy quantization condition and we illuminate the distinction between the low-frequency regimes for scattering and ionization processes. We also show that atomic stability in a high-frequency field is a consequence of the difficulty of transferring momentum. Finally, we briefly examine the distribution of drift momentum in two-color processes, illustrating the role of the ponderomotive shift and the sensitivity to the phase at which ionization occurs.
Quantitative analysis of a deeply sequenced marine microbial metatranscriptome

The potential of metatranscriptomic sequencing to provide insights into the environmental factors that regulate microbial activities depends on how fully the sequence libraries capture community expression (that is, sample-sequencing depth and coverage depth), and the sensitivity with which expression differences between communities can be detected (that is, statistical power for hypothesis testing). In this study, we use an internal standard approach to make absolute (per liter) estimates of transcript numbers, a significant advantage over proportional estimates that can be biased by expression changes in unrelated genes. Coastal waters of the southeastern United States contain 1 × 1012 bacterioplankton mRNA molecules per liter of seawater (∼200 mRNA molecules per bacterial cell). Even for the large bacterioplankton libraries obtained in this study (∼500 000 possible protein-encoding sequences in each of two libraries after discarding rRNAs and small RNAs from >1 million 454 FLX pyrosequencing reads), sample-sequencing depth was only 0.00001%. Expression levels of 82 genes diagnostic for transformations in the marine nitrogen, phosphorus and sulfur cycles ranged from below detection ( 2.7 × 109 transcripts per liter (ammonia transporter amt and ammonia monooxygenase subunit amoC). Half of the categories for which expression was detected, however, had too few copy numbers for robust statistical resolution, as would be required for comparative (experimental or time-series) expression studies. By representing whole community gene abundance and expression in absolute units (per volume or mass of environment), ‘omics’ data can be better leveraged to improve understanding of microbially mediated processes in the ocean.
Divergent effects of estradiol on gonadotropin gene transcription in pituitary fragments.

Our previous work demonstrated that in vivo estradiol (E2) administration to ovariectomized rats suppressed the transcription of the LH subunit genes within 4 h. To determine whether these effects were mediated directly at the level of the gonadotrope, the transcription rates of the LHβ, FSHβ, and α-subunits were measured in short term cultures of pituitary fragments from female rats in various physiological states. In each in vitro experiment, fragments from matched sets of hemipituitaries were used for control and treatment (10−8mE2) groups. In pituitaries from ovariectomized animals, treated in vitro with or without E2, there was no significant effect of 2 h or 6 h of E2 on FSHβ or α-subunit gene transcription, but a consistent 2- to 3-fold stimulation of LHβ mRNA synthesis. In pituitaries from intact randomly cycling rats, E2 in culture had no effect on the transcription rate of α-subunit, FSHβ, or TSHβ genes, but stimulated LHβ and PRL transcription 2- fold. Thyroid hormone treatment specifically sup...
Is seeking treatment for depression predicted by a history of depression in relatives? Implications for family studies of affective disorder

Most family studies of psychiatric illness ascertain probands through treatment facilities. If psychiatric illness in relatives influences the probability of treatment seeking, then the risk of illness in the relatives of treated probands will not be representative of the risk of illness in all probands. We have investigated this question in a population-based sample of female twins with lifetime history of DSM-III-R defined major depression (MD) (N = 753), 36% of whom reported seeking professional help for their depression. Logistic and Cox regression methods were used. Treatment seeking for MD was significantly associated with age, education, comorbidity with anxiety disorders, degree of impairment and number of symptoms. Controlling for these predictors, treatment seeking was significantly predicted by the presence of one or more relatives with a lifetime diagnosis of MD (OR = 1·62). The probability of treatment seeking for MD in the proband was significantly increased if the affected relative: (i) had an onset of their MD prior that of the proband and; (ii) themselves sought treatment for their depression. Seeking treatment in this epidemiological sample of depressed women was associated with a 32% increase in risk of MD in relatives. Selecting probands for family studies from treated populations may select for families with an increased rate of illness. For MD, this artefact can explain only a modest proportion of the familial aggregation observed in prior family studies that utilized treated probands.