cssi/SciSciGPT-SciSciNet huggingface dataset:
Correction of hindbrain herniation and anatomy of the vermis after in utero repair of myelomeningocele in sheep

Abstract Background/Purpose: In utero repair of myelomeningocele (MMC) in humans spares distal neurologic function, reverses the hindbrain herniation component of the Arnold-Chiari II malformation (ACM), and reduces the rate of postnatal shunt placement. The authors hypothesized that extravasation of cerebrospinal fluid (CSF) from the lumbar spinal cord results in herniation. This hypothesis was tested by assessing the impact of a spinal cord myelotomy on hindbrain anatomy in fetal sheep. Methods: A MMC lesion was created surgically in 34 fetal sheep at 75 days' gestation by excision of the L1–L5 lamina, the exposed dura, and surrounding tissues. A lumbar level myelotomy was performed in 28 of the 34 fetuses to open the central canal of the spinal cord to enhance egress of CSF through the MMC defect and potentially induce hindbrain herniation. At 102 days' gestation, a repair of the MMC lesion was performed in 14 fetuses with a myelotomy. Fetuses underwent autopsy at 102, 114, 120, or 140 days' gestation. Control animals underwent 2 unrelated fetal surgical procedures at approximately 70 and 110 days' gestation. The incidence of hindbrain herniation, ventricular size, biparietal diameter, brain weight, and brain anatomy were compared between the different animal groups. Results: After MMC creation, significant cerebellar tonsillar herniation was observed in 85% of fetuses that underwent creation of a myelotomy; none of the lambs without a myelotomy (n = 6) had hindbrain herniation. At autopsy, cerebellar tonsillar herniation was present at the time of MMC repair (102 days' gestation), 2 weeks after MMC repair, but was reversed 3 weeks post-MMC repair. At birth, tonsillar herniation was absent, and hindbrain anatomy was restored in 88% of the fetuses with a myelotomy that underwent fetal MMC repair. No significant differences in brain weight and ventricular size was observed between animals with and without MMC repair. Conclusions: Adding a myelotomy to the sheep model of MMC leads to hindbrain herniation that is similar to that observed in the human ACM. These experiments support the hypothesis that leakage of CSF through the exposed central canal alters the normal CSF hydrodynamics, resulting in cerebellar tonsillar herniation. Fetal MMC repair reverses hindbrain herniation and restores gross anatomy of the vermis. J Pediatr Surg 38:451-458. Copyright 2003, Elsevier Science (USA). All rights reserved.
Life-History Studies on Mexican Butterflies. IV. the Ecology and Ethology of Anatole rossi, a Myrmecophilous Metalmark (Lepidoptera: Riodinidae)

Anatole rossi Clench, a recently discovered, myrmecophilous metalmark, is known at present only from a small, isolated section of pine forest in the Sierra Tuxtla of southern Veracruz, Mexico. The 3 distinctive structures associated with the myrmecophilous existence of the late-instar larvae are discussed. During the summer months, the formicine ant Componotus abdominalis F. constructs small, shallow pens at the bases of the larval food plant, Croton repens (Euphorbiaceae), and the caterpillars remain in these pens during the daylight hours. At dusk, both ants and caterpillars ascend the plants, where the latter feed during the night but return to the pens before dawn. During the cool winter period, the ants convert the pens into deep tunnels. The last-instar larvae enter a semidiapause and remain rather quiescent for approximately 3 months. Pupation takes place in the pens and tunnels, with the ants remaining in attendance until a few days prior to emergence of the adult butterflies. These subterranean enclosures seem important to the biology of this butterfly, as they are thought to (1) protect the caterpillars from predatory ants, particularly the ponerine Ectatoma tuberculatum (Olivier); (2) carry the species through the winter season, when the adults are killed by even brief cool periods; and (3) protect the caterpillars from the annual fires that are set by the local Indians to clear the pine lands of underbrush. The biology of the adults is discussed, with special emphasis on the effects of fire and man. It is thought that fire (probably man caused) is responsible for the existence of the pine forests. These frequent fires appear to have influenced the growth pattern of the host plant and thus, indirectly, to have affected the evolution of the butterfly.
Insulin Antagonistic Effects of Growth Hormone in Short Children

Growth hormone has several insulin antagonistic effects. To determine the time course of these effects in growth-hormone-treated children, the frequently sampled intravenous glucose tolerance test was
Effect of Subculture Cycle on Growth and Indole Alkaloid Production by Catharanthus roseus Hairy Root Cultures

The effect of subculture cycles on Catharanthus roseus hairy root culture growth and indole alkaloid production was investigated by adapting the cultures to 2-, 3-, and 4-week cycles. Conductivity of the culture medium was measured every 2–3 days and the culture fresh weight determined using a conductivity-fresh weight correlation. Cultures were harvested in triplicate at 21, 28, and 35 days and analyzed for final biomass and indole alkaloid content. These experiments demonstrated that the subculture cycle could lead up to a 20% decrease in the doubling times of hairy root cultures when the subculture cycle is changed from 4- to 2-weeks. The 2-week subculture cycle yielded the fastest while the 4-week cycle yielded the slowest specific growth rates. Specific yields of tabersonine decreased from day 21 to 35 and was inversely correlated with biomass content. Total yields of lochnericine were highest in the 2-week cycle indicating a strong correlation to growth rate. Serpentine yields were lowest in the 2-week cycle and highest in the 4-week cycle, indicating inverse proportionality of serpentine accumulation to growth rate.
Bakunin: A View from Within

I never felt myself particularly suited for life in society. I felt stupid, awkward, inarticulate. I used to think that this was merely because of my inexperience. I did everything in my power to overcome it. I immersed myself in society; I scurried this way and that; and what did I find? A terrible emptiness. The pleasures and distractions that delighted others seemed to me trivial. Dances, balls-these, the pinnacle of pleasure for our youth, the highest ideals they can imagine, bored me to death. As soon as they began, I felt out of place and just as trivial as they were. I had to reject all this, and I did so, joyfully, enthusiastically, vowing never to return.... But, then, I had to find something else: the vacuum that overwhelmed me had to be filled. I withdrew into myself and locked myself in. I studied myself; and, in the end, I found within myself something to fill the emptiness.... At last I made a decision, and as soon as I did a warmth so sweet poured through my heart. I threw myself into my study; I threw myself passionately into it.... I feel as though I am being reborn; I feel as though I am watching myself being fed and nurtured. Until now I have lived only an external life. I want now to build for myself an inner existence.1
Observations on a maximum likelihood method of sequential threshold estimation and a simplified approximation

In sequential methods of measuring thresholds, the stimuli are chosen from trial to trial with the goal that the information from each trial be highly rele­ vant to the objective. The presentation of many stim­ uli far above or far below threshold is a waste of time, because the responses to such stimuli have little bearing on the question of the location of the thresh­ old. Efficiency of threshold estimation (Taylor, 1970) can be formulated in terms of the tradeoff be­ tween the standard error of the threshold estimate and the average number of trials necessary to achieve a given small standard error. A sequential method, such as the well-known PEST (Percentile Estimation by a Sequential Threshold method) of Taylor and Creelman (1967), can be more efficient by a large factor than one of the classical methods, such as con­ stant stimuli. However, even among the various se­ quential methods that are in use, there are fairly large differences in efficiency. For example, the number of trials needed to achieve a given standard error using a maximum likelihood method (Pentland, 1980; Shelton, Picardi, & Green, 1982) is, in some cases, as small as half those needed with PEST and some vari­ ations (Findlay, 1978) of the PEST method. In the maximum likelihood method of sequential threshold estimation, a new estimate of the threshold is obtained after every trial. That estimate is then used on the following trial to determine the stimulus to be presented. In the simplest cases, the stimulus value is always taken equal to the threshold estimate itself. Thus, a powerful statistical estimation method is used to concentrate stimuli densely in the region of the threshold, to maximize the relevance of the data. That seems to explain the superior efficiency. Although the maximum likelihood method was conceived and used for theoretical purposes early in the development of sequential threshold methods (Smith, 1961; Wetherill, 1963), it has not been very popular as a practical scheme for measuring thresh­ olds. This is somewhat curious, since it seems to be more efficient than more popular ones. Some hints toward an explanation may be inferred from comThis paper was written while the author was on professional leave from Cleveland State University during part of 1984. The ideas stem from research begun while the author was supported by
Catalyst aging in a coal combustion flue gas for mercury oxidation

Abstract Decay mechanism of the V 2 O 5 /TiO 2 commercial catalyst in the coal combustion flue gas was studied. Both fresh and spent catalysts with honeycomb structure, which were exposed to a coal combustion flue gas in a coal-fired boiler for over 65,000 h, were examined. The catalysts were characterized by BET analysis, FE-SEM observation with EDX analysis, and catalytic activity of Hg 0 oxidation and NO reduction was measured. Fly ash particles were observed to deposit on the spent catalyst and form the layer-like porous structure. The thickness of the ash deposition layer was 3.1 μm at the front-end of the catalyst and observed to have decreased to 0.9 μm at the back-end. The activity loss was observed to be more pronounced at the front-end of the catalyst where the most severe ash accumulation was confirmed than at the back-end of the catalyst for both Hg 0 oxidation and NO reduction. The catalytic activity, both Hg 0 oxidation and NO reduction, was found to decrease proportionally with the ash deposition thickness. The diffusion of the reactant through the porous ash deposition layer is the prevailing rate limiting step which is the main factor of the deactivation.
On the Short Time Solution for the Concentration Step at the Surface of A Rotating-Disk

The first thirty coefficients of a proposed series solution for a fundamental problem in nonsteady diffusion to a rotating disk have been evaluated. The results obtained raise serious questions not only with respect to potential practical applications of such a solution, but also in regard to the claimed convergence character of the series. Certain difficulties related to the numerical determination of these coefficients are discussed in detail.
Similarity of the primary sequences of ribosomal RNAs isolated from vegetative and developing cells of Dictyostelium discoideum

Abstract Differentiating cell aggregates of Dictyostelium discoideum exhibit a pattern of rRNA metabolism quite different from that observed in the single-celled vegetative amoebas of this organism. We have examined whether the differences are related to a requirement for the production of new types of ribosomal RNA during development. Oligonucleotide maps and supplementary sequence data for 25 S, 17 S, and 5 S rRNAs from vegetative and developing cells have revealed no detectable alterations in primary sequence distinguishing any species of rRNA in developing cells from its vegetative cell counterpart.
Adaptive low-jitter LC-based clock distribution

A low-jitter LC-based clock distribution in 0.13μm CMOS uses a frequency-tuning technique based on a voltage-swing digitizer. Optimum jitter performance is achieved by adaptively adjusting the injection-lock ratio. The efficiency of this technique results in 25% power-savings in the clock buffer for similar or better jitter performance.
Equilibrium theory for magnetic elastomers and magnetoelastic membranes

Abstract A theory for the equilibrium response of magnetoelastic membranes under pressure and applied magnetic fields is formulated on the basis of three-dimensional magnetoelasticity. A variational principle admitted by the three-dimensional theory is used to generate a model for membranes regarded as thin three-dimensional bodies. Minimum energy considerations in the presence of applied magnetic fields are used to motivate a direct theory of magnetoelastic membranes which does not require information about bulk properties. The theory is applicable to conventional elastomers magnetized through infusion with uniformly dispersed ferrous particles.
Closed-Form Solutions of Performability

If computing system performance is degradable, then as recognized in a number of recent studies, system evaluation must deal simultaneously with aspects of both performance and reliability. One approach is the evaluation of a system's "performability," which relative to a specified performance variable Y, generally requires solution of the probability distribution function of Y. In this paper we examine the feasibility of closed-form solutions of performability when Y is continuous. In particular, we consider the modeling of a degradable buffer/multiprocessor system whose performance Y is the (normalized) average throughput rate realized during a bounded interval of time. Employing an approximate decomposition of the model, we show that a closed-form solution can indeed be obtained.
Manganese in Modern and Fossil Gastropod Shells

VERY little work has been done on manganese concentrations in shell material and particularly in gastropod shells, although Doring in Vinogradov's book1 reported several analyses and found from 0.1 to 0.0001 per cent manganese by weight in gastropod shells. Krinsley and Bieri2 have determined manganese in the shells of modern and fossil pteropods.
Chemical softness and acute metal toxicity in mice and Drosophila

Abstract Correlations reported by Jones and Vaughn (1978) between chemical softness parameters and LD50s for metal compounds in rodents have been confirmed and extended. In the present study 14-day LD50s for mice were determined under uniform experimental conditions for 24 metal salts injected ip. For certain ions the correlation between the LD50 and the Pearson and Mawby (1967) softness parameter, σp is better than that obtained by Jones and Vaughn (1978) using data from diverse sources. Notably, however, we found no orrelation for the alkaline-earth metals either with σp or with other softness parameters. In parallel experiments with the same metal compounds, we also found correlations between σp and 4-day LC50s for Drosophila exposed to the salts in their food. For both the mouse and Drosophila, soft ions were generally found to be more toxic than hard ions such that their rankings are significantly correlated. Several differences in relative toxicities of the metal ions were found to occur between mice and Drosophila, and some interpretations of these findings are give. Correlations between toxicity and physicochemical parameters of toxic materials can offer insights into biochemical mechanisms of toxicity and may be useful in predicting toxicity.
Eonomic integration among caribbean countries: Evidence from purchasing power parity, 1980–2000

This paper is the first to examine if purchasing power parity holds for the Caribbean currencies for the recent period (1980–2000), and if there is any evidence of a currency bloc. The Caribbean is an important economic region especially for the United States yet it is an under-studied area as most studies examine developed country currencies and there are few studies of the nature of Caribbean exchange rates. This paper documents that purchasing power parity seems to hold among the Caribbean exchange rates for the last two decades of the 20th century. In addition, there seems to be some evidence of cointegration among the Caribbean currencies especially after the 1990 move towards economic integration in the region.
Ultrastructural changes in Paneth cells during hibernation in the ground squirrel Spermophilm lateralis

The ultrastructure of Paneth cells from jejuno-ileal segments of the small intestine of the ground squirrel, S. lateralis, was examined under normal euthermic conditions and during the profoundly depressed metabolic conditions of natural hibernation. Paneth cells obtained from hibernating animals gave evidence of markedly reduced activity when compared to Paneth cells from euthermic animals. In hibernating animals, the nuclei were smaller, with less prominent nucleoli and with an increased proportion of heterochromatin. In hibernating animals, the rough endoplasmic reticulum was fragmentary and poorly organized, in contrast to the typical arrangement of concentric lamellae seen in euthermic animals. Although the total number of ribosomes was decreased in hibernating animals, there were proportionally more free ribosomes than in euthermic animals. Paneth cells from hibernating animals also contained a greater number of apical secretory granules which were smaller and more variable in electron density than granules from control animals. These ultrastructural features indicate that during hibernation the Paneth cell is relatively quiescent.
A simple time-cost tradeoff algorithm

Abstract In this note a procedure is given for shortening the duration of a project al low cost. The procedure allows de-shortening of activities which may have been shortened initially and they happen to be exclusively in the path which has been shortened excessively. An example has been solved to illustrate the algorithm.
Intercomparison of near-bottom kinematics by several wave theories and field and laboratory data

Abstract This paper summarizes a study to identify the most suitable theories (models) for representing the near-bottom kinematics due to waves and/or currents. The basis for the evaluation of the various models included comparison of models with field and laboratory data and intercomparison of various models. Wave theories evaluated included two versions of the linear wave theory, the Stokes II, III and V order theory, the Cnoidal theory, the Extended Velocity Potential theory and the Stream Function theory.
The Influence of Fluorine Substitution on the Aromaticity of Carbocyclic Systems

Huckel integral parameters were evaluated for F and Cl by fitting calculated to observed heats of atomization. With these, empirical C-F and C-Cl bond energy terms were obtained from Huckel calculations on a set of 34 halogen-substituted acyclics. The effect of fluorine substitution on the resonance energy per π electron (REPE) of cyclic compounds was then examined. Both F and Cl were found to act as electron donors in affecting REPE with F being the stronger.
Dynamic response of 1-in. form factor disk drives to external shock and vibration loads

The dynamic response of the head disk interface is investigated numerically for two different designs of 1-in. hard disk drive enclosures, the so-called “thin” enclosure and the “thick” enclosure. First, the in-plane and out-of-plane vibration response is determined. Then, the effects of linear shock and head slap are studied. Simulation results show that the thinner enclosure has better performance with respect to forced vibrations in terms of reduced amplitude of slider vibrations. In addition, the effect of operational shock on the dynamic characteristics of textured and untextured sliders is studied. A finite element formulation of the time-dependent Reynolds equation (with Boltzmann slip flow correction) was used to obtain the air bearing response. The results show that the dynamic flying characteristics of textured sliders are improved compared to that of untextured sliders.
Avian fatty acid synthetase: evidence for short-term regulation of activity.

Abstract Liver biopsies were performed on starved chicks at 0 and 4 h after refeeding a fat-free diet. Fatty acid synthetase activity increased after refeeding, and administration of cycloheximide did not prevent the rise of enzyme activity. Incorporation of [ carboxyl - 14 C]leucine into fatty acid synthetase was measured in enzyme purified from the livers of starved chicks, starved-refed (4 h) chicks, and starved-refed chicks injected with cycloheximide. The data suggest that the synthesis of enzyme protein was inhibited in starved and cycloheximide-treated refed chicks in comparison with refed chicks. Liver cytosol from fed or starved chicks was filtered through centrifuge ultrafiltration membranes and the residues were suspended in the same or opposite filtrates. Fatty acid synthetase activity in residues from starved chicks was stimulated when suspended in filtrates from fed chicks. The evidence is consistent with the hypothesis that a portion of the fatty acid synthetase in the liver of starved chicks is present as an inactive form which can be activated upon refeeding.
Computability-Theoretic Properties of Injection Structures

We study computability-theoretic properties of computable injection structures and the complexity of isomorphisms between these structures. It is proved that a computable injection structure is computably categorical iff it has finitely many infinite orbits. Again, a computable injection structure is $ \Delta_2^0 $ -categorical iff it has finitely many orbits of type ω or finitely many orbits of type Z. Furthermore, every computably categorical injection structure is relatively computably categorical, and every $ \Delta_2^0 $ - categorical injection structure is relatively $ \Delta_2^0 $ -categorical. Analogs of these results are investigated for $ \Sigma_1^0 $ , $ \Pi_1^0 $ , and n-c.e. injection structures. We study the complexity of the set of elements with orbits of a given type in computable injection structures. For example, it is proved that for every c.e. Turing degree b, there is a computable injection structure A in which the set of all elements with finite orbits has degree b, and for every $ \Sigma_2^0 $ Turing degree c, there is a computable injection structure B in which the set of elements with orbits of type ω has degree c. We also have various index set results for infinite computable injection structures. For example, the index set of infinite computably categorical injection structures is a $ \Sigma_3^0 $ -complete set, and the index set of infinite $ \Delta_2^0 $ -categorical injection structures is a $ \Sigma_4^0 $ -complete set. We explore the connection between the complexity of the character and the first-order theory of a computable injection structure. It is shown that for an injection structure with a computable character, there is a decidable structure isomorphic to it. However, there are computably categorical injection structures with undecidable theories.
The Effect of Mandatory Protective Daycare on Mutual Attachment in Maltreating Mother-Infant Dyads.

Twenty-two children for whom protective daycare was sought were followed for four years. Those placed in daycare had earlier removals for foster care than the children who could not be placed in daycare. At the end of four years the outcomes for the two groups were similar. It was concluded that mandatory protective daycare had hastened, but not caused, the removal of the children. This unexpected outcome was explained in terms of attachment theory. Evidence was cited showing that both maltreating mothers and their infants could be considered anxiously attached and that such individuals would be more than normally vulnerable to experiences of separation. In this study both mothers and infants reacted to the daycare placement with a combination of direct anger and ignoring (repressed anger). These reactions exacerbated the already strained mother-infant relationships leading to increased abuse and neglect of the infants and, therefore, earlier removal.
Establishing efficient electrical contact to the weak crystals of triethylsilylethynyl anthradithiophene

Triethylsilylethynyl anthradithiophene (TES ADT) forms weak van der Waals crystals in the solid state because its bulky TES side groups limit intermolecular interactions. Consequently, TES ADT melts easily and locally when it experiences heat conduction from the metal evaporation process to form electrical contacts. The performance of TES ADT thin-film transistors is thus highly dependent upon the manner in which electrical contacts are established to the organic semiconductor. Bottom-contact TES ADT thin-film transistors in which the electrodes are fabricated prior to the organic semiconductor deposition routinely exhibit a charge-carrier mobility of 0.11 ± 0.05 cm2/V·s. Top-contact thin-film transistors with electrodes patterned directly on top of TES ADT by metal evaporation through a shadow mask, on the other hand, exhibit highly variable device characteristics with a charge-carrier mobility 0.03 ± 0.03 cm2/V·s. To avoid thermal damage to TES ADT during electrode fabrication, we separately defined gol...
Activities of carboxylating enzymes in the CAM species Opuntia ficus-indica grown under current and elevated CO2 concentrations.

Responses of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPCase) to an elevated atmospheric CO2 concentration were determined along with net CO2 uptake rates for the Crassulacean acid metabolism species Opuntia ficus-indica growing in open-top chambers. During the spring 13 months after planting, total daily net CO2 uptake of basal and first-order daughter cladodes was 28% higher at 720 than at 360 μl CO2 l-1. The enhancement, caused mainly by higher CO2 assimilation during the early part of the night, was also observed during late summer (5 months after planting) and the following winter. The activities of Rubisco and PEPCase measured in vitro were both lower at the elevated CO2 concentration, particularly under the more favorable growth conditions in the spring and late summer. Enzyme activity in second-order daughter cladodes increased with cladode age, becoming maximal at 6 to 10 days. The effect ofelevated CO2 on Rubisco and PEPCase activity declined with decreasing irradiance, especially for Rubisco. Throughout the 13-month observation period, O. ficus-indica thus showed increased CO2 uptake when the atmospheric CO2 concentration was doubled despite lower activities of both carboxylating enzymes.
Why can't I manage my digital images like MP3s? The evolution and intent of multimedia metadata

This paper considers the deceptively simple question: Why can't digital images be managed in the simple and effective manner in which digital music files are managed? We make the case that the answer is different treatments of metadata in different domains with different goals. A central difference between the two formats stems from the fact that digital music metadata lookup services are collaborative and automate the movement from a digital file to the appropriate metadata, while image metadata services do not. To understand why this difference exists we examine the divergent evolution of metadata standards for digital music and digital images and observed that the processes differ in interesting ways according to their intent. Specifically music metadata was developed primarily for personal file management and community resource sharing, while the focus of image metadata has largely been on information retrieval. We argue that lessons from MP3 metadata can assist individuals facing their growing personal image management challenges. Our focus therefore is not on metadata for cultural heritage institutions or the publishing industry, it is limited to the personal libraries growing on our hard-drives. This bottom-up approach to file management combined with p2p distribution radically altered the music landscape. Might such an approach have a similar impact on image publishing? This paper outlines plans for improving the personal management of digital images-doing image metadata and file management the MP3 way-and considers the likelihood of success.
Feeding induced by food deprivation is differentially reduced by opioid receptor antisense oligodeoxynucleotide probes in rats

Abstract The increases in food intake following 24 h of food deprivation are reduced by systemic and central administration of general opioid antagonists. The use of selective opioid antagonists revealed that μ-selective antagonists were more effective than κ-selective antagonists in reducing deprivation-induced intake, whereas δ-selective antagonists were minimally effective. Antisense oligodeoxynucleotide (AS ODN) probes directed against different exons of the μ (MOP), δ (DOP), κ (KOP) and nociceptin (NOP) opioid peptide receptor genes have been able to differentially alter feeding responses elicited by glucoprivation, lipoprivation and by different opioid peptides and receptor agonists. The present study examined whether lateral ventricular administration of AS ODN probes directed against different exons of the MOP, DOP, KOP or NOP opioid receptor genes altered food intake and body weight changes following 24 h of food deprivation in rats. Deprivation-induced feeding was significantly and maximally reduced by an AS ODN probe directed against exon 2, but not exons 1 or 3 of the KOP gene. This response was also significantly though modestly reduced by AS ODN probes directed against exons 2, 3 or 4 of the MOP gene, exon 1 of the DOP gene, or exon 1 of the NOP gene. Recovery of body weight following postdeprivation food reintroduction was significantly reduced by AS ODN probes directed against either exons 2, 3 or 4 of the MOP gene, exons 1 or 2 of the DOP gene, or exons 1, 2 or 3 of the KOP gene. The parallel patterns in the magnitude of alterations in deprivation-induced feeding by δ antagonists and DOP AS ODN probes on one hand, and by κ antagonists and KOP AS ODN probes on the other, provide converging and complementary evidence for their relative involvement in this response. The modest reductions by MOP AS ODN probes relative to the more potent reductions induced by μ-selective antagonists suggest that the μ receptor-mediated actions upon deprivation-induced feeding may involve recently-identified splice variants or isoforms of the MOP gene.
Sulfide effects on Thalassia testudinum carbon balance and adenylate energy charge

Abstract Low iron content in tropical carbonate sediments limits the formation of iron–sulfide compounds such as pyrite. Thus, seagrasses in the tropics may be more susceptible to sulfide toxicity. Sediment sulfide levels greater than 2 mM and up to 13 mM have been hypothesized to cause widespread ‘die-back’ of the tropical seagrass Thalassia testudinum in a subtropical lagoon, Florida Bay. Hydroponic chambers were used to determine the effects of sulfide (0.0, 2.0, 4.0, 6.0 and 10.0 mM) on root and leaf adenylate ratios, energy charge (EC), leaf O 2 flux, and growth of T. testudinum under light-saturated conditions. T. testudinum did not suffer mortality under short-term (48 h) exposure to sulfide concentrations up to 10 mM, but several metabolic stress responses were observed. Root ATP and energy charge significantly declined ( P P T. testudinum leaf metabolism to short-term sulfide exposure. Our data do not support the hypothesis that sulfide initiates rapid ‘die-off’ episodes of T. testudinum in Florida Bay, although this phytotoxin may play a critical role as a root carbon drain over long-term exposures.
Spatial and temporal variability of phytoplankton biomass and taxonomic composition around Elephant Island, Antarctica, during the summers of 1990–1993

During the austral summers of 1990–1993, phytoplankton studies were conducted in the vicinity of Elephant Island, Antarctica, to investigate the spatial and temporal variability of phytoplankton biomass and taxonomic composition. There was much intraannual variability, with a trend for increasing biomass from January–February (Leg I) to February–March (Leg II), except in the 1993 studies. There was also a change in phytoplankton composition between the two legs. During 1990–1991 the increase was due mostly to diatoms, during 1992 mostly to an increase of flagellates; during 1993 there was a decrease in total biomass between the two legs, with diatoms decreasing, so that dinoflagellates, which increased slightly in numbers, dominated the biomass during the second leg. There was also much inter-annual variability, with the summers of 1990–1991 having greater biomass and higher proportions of microplanktonic diatoms than that of 1992–1993, which had a higher proportion of flagellates. Cluster analyses revealed the presence of four major phytoplankton assemblages, with varying geographical distributions. The northwestern portion of the grid (Drake Passage waters), was characterized by nanoplanktonic diatoms during 1990–1991 and 1993, but by nanoplanktonic flagellates during 1992. The central area (Drake-Bransfield confluence) was characterized by microplanktonic diatoms in 1990–1991, but by cryptophytes or flagellates in 1992–1993. The south and southeastern portion of the area (Bransfield Strait waters) was characterized mainly by either cryptophytes or other flagellates during all 4 yr. The spatial and temporal variability of phytoplankton could not be ascribed specifically to the geographical extent of the different water masses found in the study area, but appears to be due to changing growth conditions in the upper water column as influenced by physical mixing and meteorological conditions, as well as to effects of differential grazing.
Both major and minor peptide-binding pockets in HLA-A2 influence the presentation of influenza virus matrix peptide to cytotoxic T lymphocytes.

Abstract Most of the polymorphic residues in class I MHC molecules are concentrated in the α 1- and α2-domains with their side chains pointing towards the antigen peptide site. Previous crystal structure analysis revealed six pockets inside the peptide-binding groove and the “extra” electron density in some of the pockets indicated that the pockets are involved in direct peptide binding. In order to investigate the functional role of individual positions from each pocket in antigen presentation, 37 HLA-A2 variants with single amino acid substitution in the peptide-binding groove were generated and used to analyse the specificity of influenza A virus matrix peptide-specific, HLA-A2-restricted CTL. The ability to present peptide by each variant was studied in detail by peptide titration, cold target inhibition, time course and limiting dilution analysis. The direct effect on peptide binding by these substitutions was determined by cell surface class I MHC molecule reconstitution analysis. The results demonstrated that each of the six peptide binding pockets plays a role in T cell recognition. Substitutions introduced into pocket F had less effect on CTL recognition than substitutions introduced in other pockets. With the exception of Tyr substitution for Phe9, single amino acid substitutions in the peptide-binding groove had only minor effects on peptide binding. Therefore, the impact of the substitutions in altering the epitopes recognized by CTL seems to be mediated through an alteration in the conformation of the bound peptide.
Frontal lobe ataxia.

Background Gait abnormalities often result from disorders intrinsic to the cerebellum. Gait difficulties resulting from frontal lobe disease are less common but well recognized. The pathophysiologic mechanism of this type of ataxia is not well understood. One promising explanation implicates involvement of the frontopontocerebellar tract (Arnold's bundle). This tract originates in the frontal lobe in Brodmann's area 10 and carries information on intended movement to the contralateral cerebellum via the pontocerebellar peduncle. Interruption of this tract deprives the cerebellum of this information, thus impairing coordination and locomotion. Methods A patient is described with a large bilateral, medialorbital, frontal lobe lesion, progressive gait impairment, and dysarthria. The lesion is defined by magnetic resonance imaging (MRI) and positron emission tomography (PET) using 18-fluorodeoxyglucose. The cystic component of the lesion was drained surgically. Results The PET scan using 18-fluorodeoxyglucose showed a normal metabolic rate in the brain stem, a 10%-15% decrease in metabolism in the thalmus and a symmetric decrease of only 15% in the cerebellum bilaterally. The MRI of the cerebellum did not show any significant atrophy. The patient's speech improved, but there was minimal change in her gait ataxia after surgical drainage and partial removal of the cystic frontal lobe lesion. Conclusions The patient's syndrome supports the view that frontal lobe ataxia is an established although rare clinical entity, and this report adds original information defining the syndrome with MRI and PET studies. The 15% metabolic decrease in the cerebellum with PET is highly supportive of the syndrome of frontal lobe ataxia and not pathology intrinsic to the cerebellum. The syndrome of frontal lobe ataxia in this patient is due to interruption of the frontopontocerebellar pathway originating in Brodmann's area 10.
Dual-depth SSOCT for simultaneous complex resolved anterior segment and conventional retinal imaging

We present a novel optical coherence tomography (OCT) system design that employs coherence revival-based heterodyning and polarization encoding to simultaneously image the ocular anterior segment and the retina. Coherence revival heterodyning allows for multiple depths within a sample to be simultaneously imaged and frequency encoded by carefully controlling the optical pathlength of each sample path. A polarization-encoded sample arm was used to direct orthogonal polarizations to the anterior segment and retina. This design is a significant step toward realizing whole-eye OCT, which would enable customized ray-traced modeling of patient eyes to improve refractive surgical interventions, as well as the elimination of optical artifacts in retinal OCT diagnostics. We demonstrated the feasibility of this system by acquiring images of the anterior segments and retinas of healthy human volunteers.
Evidence from en-echelon cross-grain ridges for tensional cracks in the Pacific plate

Sea-floor topography in the Pacific is mainly aligned with original spreading directions1, but is overprinted by alignments created by mid-plate processes. Spreading produces abyssal hills and fracture zones, and mid-plate volcanism generates seamounts, isolated or in chains. A different category of topography, the 'Cross-grain', discovered in geoid-height data collected by the Seasat radar altimeter2, comprises linear troughs and swells spaced ∼200 km apart, oblique to fracture zones and abyssal hills but parallel to the Hawaiian chain. Three models have been proposed for the Cross-grain: small-scale convection, organized into longitudinal rolls by the shear of the Pacific Plate2; compressive buckling3; and lithospheric boudinage resulting from plate-wide tensile stresses4,5. None of the previously available data ruled out any of these models. Here we report multi-beam bathymetric data revealing long, narrow en-echelon ridges along the Cross-grain, interpreted as evidence of tension cracks in the Pacific plate.
Absolute scaling of sensory magnitudes: a validation.

The hypothesis that, in magnitude estimation and production, subjects tend to pair numbers with sensation magnitudes on absolute rather than ratio scales is tested experimentally. This implies that not only sensations, but also numbers acquire absolute psychological magnitudes. The specific experiments are performed on loudness and line lengths. The latter reveal that the subjective magnitudes of numbers are formed before the age of 6 and do not change after that age. It is suggested that the absolute coupling of numbers with sensation magnitudes originates from the concept of numerosity where numbers have absolute meanings. This work was supported by N1H Grant NS-03950.
Breakdown of Matthiessen's rule in the high-Tc superconducting oxides

Abstract The normal state resistivities of the new high- T c superconductors show enormous deviations from Matthiessen's rule. These deviations are clear evidence for the large role played by grain boundary scattering in these materials, and strongly suggests that in the superconducting state these materials will behave as Josephson coupled arrays. A simple model, previously used to describe quench-condensed superconducting films, is introduced to describe the grain boundary scattering.
The endothelial biology of sickle cell disease

Abbreviations: GP = g l y c o p r o t e i n ; I C A M = in te rce l lu la r a d h e s i o n m o l e c u l e ; IL = in ter leukin; M V E C = m i c r o v a s c u l a r e n d o t h e l i a l cel l ; INF = in te r fe ron ; RBC = red b l o o d cel l ; TNF = t u m o r necrosis f a c t o r ; TSP = t h r o m b o s p o n d i n ; V C A M = v a s c u l a r cel l a d h e s i o n m o l e c u l e ; WBC = w h i t e b l o o d cel l ; v W f = v o n W i l l eb rand f a c t o r
Frequency dependence of tidal Q

For studies of tidal evolution, values of the key parameter Q, and its frequency dependence, are often derived from estimates of internal energy dissipation when a satellite, planet, or star is physically distorted. Such estimates come from geophysical or astrophysical modeling, from seismic data, from ad hoc assumptions, or from constraints based on current spins and orbits. In a standard procedure, Q values are used to determine the lag in the response to each Fourier component of the tidal potential. The separate components are then co-added. The basis for this procedure is the analogy of the damped, driven, harmonic oscillator. However, this lag-and-add procedure would not be justifiable even for such a simple system, except for a very specific dependence of Q on frequency. There is no reason to expect the lag-and-add procedure to be relevant for a complex system, because the relationship between dissipation rates and tidal lags is unknown. This widely applied type of model is a reasonable approximation only if the decomposed tidal potential involves a narrow range of frequencies, and thus may only be appropriate for analyses to low order in orbital eccentricity and inclination.
Hatchability, viability, and infectivity of Hydatigera taeniaeformis eggs.

Eggs of Hydatigera taeniaeformis were tested in vitro for hatchability in an effort to predict in vivo results in laboratory animals. Hatching was accomplished in solutions containing cholesterol, trypsin, pancreatin, bile and sodium tauroglycolate. Twelve hatching solutions were used. Each differed from the others in either bile concentration, pancreatin concentration or hydrogen ion concentration. The hatching medium containing five % bile concentration gave the largest percentage of hatched eggs. There were no appreciable effects of changes in pancreatin concentrations and hydrogen ion concentrations. Viability was determined by observing motility in the hatched oncospheres and in the ability of the oncospheres to take up vital stains. In vivo tests were made using the best hatching medium. The per cent eggs hatched was compared to the per cent infectivity in the rat. The correlation coefficient was 0.73 for the results obtained. Although this was not a high correlation, it is thought that this method of determining infectivities should be further investigated.
Multiple soliton solutions for the Bogoyavlenskii’s generalized breaking soliton equations and its extension form

Abstract In this work, two generalized breaking soliton equations, namely, the Bogoyavlenskii’s breaking soliton equation and its extended form, are examined. The complete integrability of these equation are justified. Multiple soliton solutions and multiple singular soliton solutions are formally derived for each equation. The additional terms of these equations do not kill the integrability of the typical breaking soliton equation. The Cole–Hopf transformation method and the simplified Hereman’s method are applied to conduct this analysis.
Tumors of the Central Nervous System

Neoplasia of the central nervous system (CNS) can be divided into two main categories: nonpituitary CNS neoplasia and pituitary adenomas. Nonpituitary CNS neoplasias are generally compressive in nature, although some are also invasive. The majority of reported CNS tumors are secondary with only a few originating from nervous tissue. Pituitary adenomas predominantly occur in the pars intermedia of the older horse. Clinical signs, diagnostic testing, and possible treatments are discussed.
Finger on the Pulse: The Value of the Activity Stream in the Enterprise

The activity stream, which syndicates user activities across social media, has been gaining popularity on the web. With social media infiltrating the enterprise and higher portions of the workforce becoming accustomed to consuming information through activity streams, it also has the potential to play a key role in shaping the workplace. This work provides a first comprehensive study of an enterprise activity stream. We analyze different characteristics of the stream, its usage through a faceted search-based application, and the way users search it compared to traditional enterprise search. We also discuss various use cases of the stream, both from an individual employee’s perspective and from an organizational perspective, exposing the potential value and role of the activity stream in the enterprise of the future.
A new era for fibrodysplasia ossificans progressiva: a druggable target for the second skeleton

Fibrodysplasia ossificans progressiva (FOP) is a disabling genetic condition that leads to the formation of a second (heterotopic) skeleton, and is the most catastrophic disorder of heterotopic ossification in humans. Throughout childhood and early adult life, FOP progressively immobilizes all of the joints of the normotopic skeleton, rendering movement impossible. At present, there is no effective prevention or treatment. Recently, a recurrent mutation in the glycine-serine activation domain of the activin receptor IA/activin-like kinase-2, a bone morphogenetic protein type I receptor, was reported in all sporadic and familial cases of classic FOP, making this one of the most highly specific disease-causing mutations in the human genome. The discovery of the FOP gene establishes a critical milestone in understanding FOP, reveals a highly conserved druggable target in the TGF-beta/bone morphogenetic protein signaling pathway and compels therapeutic approaches for the development of small molecule signal transduction inhibitors for activin-like kinase-2. Effective therapies for FOP, and possibly for a vast array of more common conditions of heterotopic ossification, will be based on blocking activin-like kinase-2, a critical node in the BMP signaling pathway.
Vertical cavity surface emitting lasers laterally confined by 2-dimensional photonic crystals

Summary form only given. Recent increases in data traffic have motivated research into vertical-cavity surface-emitting lasers (VCSELs) penetrating into single mode regimes as well as multimode fiber links. For these applications, a VCSEL with single mode operation has been demanded. We investigate a VCSEL structure laterally confined by a 2D-photonic crystal using the effective index model.