cssi/SciSciGPT-SciSciNet huggingface dataset:
Incidence of bracket failure during orthognathic surgery: a comparison of two techniques to establish interim maxillomandibular fixation

The purpose of this study is to review the frequency of bracket failure using two different techniques for establishing interim fixation during orthognathic surgery. The first group (standard technique) had a maxillomandibular fixation (MMF) established during surgery by ligating splints to orthodontic appliances. The second group of patients had an interim fixation established using maxillomandibular screws (alternative technique). Preoperative and immediate postoperative panoramic radiographs were examined for loose and or missing brackets in both groups. Intraoperative observations were also recorded in the second group. The type of surgery (one- or two-jaw) and whether or not cemented bands on the molars were present were noted. A Pearson’s chi-square analysis was done comparing the two groups. There were 210 patients in the first group and 104 in the second. The overall incidence of missing or loose brackets following surgery in the standard technique group was 16 %; 172 of them had a cemented band on either the first or on the first and second molars. There was a higher incident of lost or loose bonded brackets when the patients had no cemented brackets or underwent a two-jaw surgery. In the second group of 104 patients, there was one loose or missing brackets caused by the application of MMF (Pearson’s chi-square value = 15.84, p < 0.0001). When using orthodontic brackets to establish interim fixation, the incidence of missing or loose brackets during orthognathic surgery was dramatically higher in two-jaw cases and in cases where only bonded brackets were placed by the orthodontist. When using maxillomandibular screws to establish interim fixation, the problem has been greatly diminished.
Design and Performance of Parallel and Distributed Approximation Algorithms for Maxcut

We develop and experiment with a new parallel algorithm to approximate the maximum weight cut in a weighted undirected graph. Our implementation starts with the recent (serial) algorithm of Goemans and Williamson for this problem. We consider several different versions of this algorithm, varying the interior-point part of the algorithm in order to optimize the parallel efficiency of our method. Our work aims for an efficient, practical formulation of the algorithm with close-to-optimal parallelization. We analyze our parallel algorithm in the LogP model and predict linear speedup for a wide range of the parameters. We have implemented the algorithm using the message passing interface (MPI) and run it on several parallel machines. In particular, we present performance measurements on the IBM SP2, the Connection Machine CM5, and a cluster of workstations. We observe that the measured speedups are predicted well by our analysis in the LogP model. Finally, we test our implementation on several large graphs (up to 13,000 vertices), particularly on large instances of the Ising model.
Multiplexing of interferometric sensors using phase-generated carrier techniques

The multiplexing of four interferometric sensor outputs on a single optical fibre using a phase-generated carrier technique is demonstrated. Low crosstalk ( – 60 dB) and high performance (minimum detectable phase shifts of 2–18 μrad) were achieved with this configuration. This technique is expandable to large numbers of sensors.
Motion generation of robotic surgical tasks: Learning from expert demonstrations

Robotic surgical assistants offer the possibility of automating portions of a task that are time consuming and tedious in order to reduce the cognitive workload of a surgeon. This paper proposes using programming by demonstration to build generative models and generate smooth trajectories that capture the underlying structure of the motion data recorded from expert demonstrations. Specifically, motion data from Intuitive Surgical's da Vinci Surgical System of a panel of expert surgeons performing three surgical tasks are recorded. The trials are decomposed into subtasks or surgemes, which are then temporally aligned through dynamic time warping. Next, a Gaussian Mixture Model (GMM) encodes the experts' underlying motion structure. Gaussian Mixture Regression (GMR) is then used to extract a smooth reference trajectory to reproduce a trajectory of the task. The approach is evaluated through an automated skill assessment measurement. Results suggest that this paper presents a means to (i) extract important features of the task, (ii) create a metric to evaluate robot imitative performance (iii) generate smoother trajectories for reproduction of three common medical tasks.
Infrastructure Sustainability: Streamlining Life Cycle Assessment for Practicing Bridge Engineers

Life cycle assessment (LCA) can help bridge design engineers understand, measure, and evaluate the initial and long term environmental impacts of bridge projects, such as energy use and carbon dioxide (CO2) emissions. LCA can be a helpful tool when comparing conventional construction materials with those that claim to be more environmentally sustainable because it provides the engineer with quantified information on impacts that cannot be identified by a typical bridge life cycle cost analysis (BLCCA). This study investigates the life cycle environmental impacts for a small single span bridge project. A life cycle inventory is completed using the PaLATE v2.1 tool as modified for use with the Greenroads™ Rating System, and reports quantities for two key indicators of environmental impact for the project: energy use and CO2. This research demonstrates that LCA tools can provide useful environmental information quickly and easily for structural engineers, but streamlined tools also require an understanding of the inherent limitations of their data sources and analysis methods.
Pattern of Thietaviopsis basicola in tobacco field soil

The pattern of Thielaviopsis basicola in two tobacco field soils was examined using systematic and random sampling methods. In three systematic samplings and one random sampling, the frequencies of observed population densities gave a good fit to the negative binomial distribution; a poor fit was found for one random sampling. For all samplings, the variance to mean ratios were greater than 1, and Lloyd's index of patchiness values ranged from 1.5 to 5.7. These results indicate T. basicola is clumped in tobacco field soil and has a low to moderate degree of aggregation. Population densities of T. basicola were typically less than 103 propagules per g soil and decreased with depth in the soil profile.
Multi-level parallelism for incompressible flow computations on GPU clusters

We investigate multi-level parallelism on GPU clusters with MPI-CUDA and hybrid MPI-OpenMP-CUDA parallel implementations, in which all computations are done on the GPU using CUDA. We explore efficiency and scalability of incompressible flow computations using up to 256GPUs on a problem with approximately 17.2 billion cells. Our work addresses some of the unique issues faced when merging fine-grain parallelism on the GPU using CUDA with coarse-grain parallelism that use either MPI or MPI-OpenMP for communications. We present three different strategies to overlap computations with communications, and systematically assess their impact on parallel performance on two different GPU clusters. Our results for strong and weak scaling analysis of incompressible flow computations demonstrate that GPU clusters offer significant benefits for large data sets, and a dual-level MPI-CUDA implementation with maximum overlapping of computation and communication provides substantial benefits in performance. We also find that our tri-level MPI-OpenMP-CUDA parallel implementation does not offer a significant advantage in performance over the dual-level implementation on GPU clusters with two GPUs per node, but on clusters with higher GPU counts per node or with different domain decomposition strategies a tri-level implementation may exhibit higher efficiency than a dual-level implementation and needs to be investigated further.
Hypothalamic-Pituitary-Adrenal Axis and the Termination of the Stress Response: Alterations in Children with Psychosocial Growth Failure† 495

Hypothalamic-Pituitary-Adrenal Axis and the Termination of the Stress Response: Alterations in Children with Psychosocial Growth Failure† 495
Binary and Ternary Aggregation within Tethered Protein Constructs

The free energy per monomer of a protein aggregate varies with the number of participating monomers n. The change of this free energy with aggregate size, DeltaDeltaG(n), is difficult to determine by sedimentation or concentration studies. We introduce a kinetic approach to quantitate the free energy of aggregates in the presence of tethers. By linking the protein U1A into dimers and trimers, a high effective concentration of the monomers is achieved, together with exact size control of the aggregates. We found that the free energy of the aggregate relative to the native monomer reached a maximum for n = 2, and decreased by DeltaDeltaG(2) = -3.1 kT between dimer and trimer.
Characterization of glasses and ceramics with the analytical electron microscope

Abstract Ongoing improvements in the analytical electron microscope, improved ion-thinning equipment, and advances in x-ray energy spectroscopy have resulted in increased characterization capabilities for glass and ceramic materials. The result of combining microstructural information from thin sections and crystallographic information obtained by electron diffraction with qualitative and semiquantitative compositional data is a more complete characterization of very small volumes of material than here-to-fore possible. Illustrative examples of the application of these tools to the study of polarizing glasses, soots, phase-separated glasses, glass-ceramics, and interfaces are given.
Effect of a missing observation on Hotelling's generalized T02

A generalization of the missing plot technique in univariate linear models to the multivariate case is given in this paper. The estimate of the missing observation vector produces the correct error matrix and the correct parameter estimates but the hypothesis matrix is biased. The adjustment required to the test, for achieving the desired level of significance, when the biased hypothesis matrix is used, is derived.
Some characteristics of the mitochondrial and soluble forms of malate dehydrogenase in lemon fruits.

Studies on malate dehydrogenase (l-malate:NAD oxidoreductase, EC 1.1.1.37) in soluble and mitochondrial fractions from sweet lemon (Citrus limettioides, Tanaka) and sour lemon (Citrus limon, L.) were undertaken. The first contains low levels of organic acids and the last contains high levels. These studies involved distribution, Km determinations for 4 substrates (NADH, NAD+, oxalacetate and malate), oxalacetate substrate inhibition, and effects of 3′-adenylic acid, AMP, ADP and ATP on enzyme activity in two buffers. Product inhibition of NADH oxidation by NAD+ was also studied. The studies demonstrated that some differences in enzymatic activity exist between sweet and sour lemon fruits; the most apparent was that intact mitochondria from sour lemon had a much higher Km value (almost 5 times) for NADH than mitochrondria from sweet lemon. Solubilization and partial purification of the mitochondrial enzyme from both lemons resulted in the disappearance of that significant difference. In both lemons, mitochondrial enzyme accounted for between 23 and 36% of the total enzymatic activity depending on the oxalacetate concentration used in the assay. Oxalacetate inhibition of NADH oxidation by malate dehydrogenase did occur in both soluble and mitochondrial fractions and was found to be of a noncompetitive type. Phosphate buffer alleviated most but not all of the inhibition of oxalacetate. The Km for oxalacetate was much higher in phosphate buffer than in Tris-HCl buffer. The Km for NADH was not affected by kind of buffer even though phosphate buffer increased the apparent maximal velocity of the reaction. Of the 3 adenosine nucleotides, AMP showed the greatest inhibitory effect on NADH oxidation by solubilized mitochondrial enzyme. A 5′-adenosine phosphate moiety was necessary for inhibition. Although the nature of AMP inhibition seemed competitive, high levels of NADH failed to completely overcome it. NAD+ (simultaneously added with NADH) competitively inhibited NADH oxidation. If, however, the enzyme was preincubated with NAD+ + oxalacetate with NADH added last, the inhibition was of an uncompetitive nature.
Bathyscaph Observations in the La Jolla Submarine Fan Valley: ABSTRACT

Observations, made from the bathyscaph Trieste during six dives to depths ranging from 1,800 to 3,000 feet, reveal that submarine erosion is actively modifying a series of step-like terraces forming the internal walls of the La Jolla Submarine Fan Valley. The innermost terrace is cut by a narrow, steep-walled, flat bottomed channel that forms the longitudinal axis of the valley. Beneath a thin mud cover, the channel contains sand and plant fill that is entirely different from that found on or forming the internal terraces. The steep slopes (up to 70 degrees), found where the innermost terraces lead down to the inner channel, have slump scars, striations, and fresh burrows that indicate they are presently being eroded by marine processes. Terrace sediments are bedded and s mi-consolidated and do not appear to have been deposited in the present erosional environment of the canyon. On one of the dives, large rounded rock boulders, up to 3 feet in diameter, were found scattered through the interbedded sand, mud, and plant material found in the inner channel. The nearest possible source for these large erratics is more than one-fourth of a mile from their present location. The following characteristics are arguments against dense, high-velocity turbidity currents as agents of erosion or transportation in the present day La Jolla Fan Valley: (1) the lack of scour depressions around large man-made objects found in the sands of the inner channel, (2) the sinuous course of the inner channel, (3) a low axial gradient, (4) a lack of inner channel sediment on terraces 10 feet above the channel bottom, and (5) the heterogeneous mixture of fragile sea-grass mats, large boulders, and micaceous sands. Pulsating bottom currents with velocities up to 0.45 knots have been measured. These currents were observed to have sufficient strength to transport fine micaceous sand and unconsolidated clay-sized particles along the bottom of the inner channel. However, the large boulders associated with sands and organic debris, foreign to the surrounding sea floor, must have been transported by another mechanism; gravity creep and progressive slumping of the entire fill of the erosion channel are suggested agents. End_of_Article - Last_Page 338------------
Queens of the hill: Creative destruction and the emergence of executive leadership of women

Despite penetrating the middle management ranks of many U.S. businesses, women continue to lag far behind men in their appointments to top leadership positions. Many explanations exist for why the glass ceiling exists, but few theories offer suggestions for how women break through this ceiling. In this paper we propose that the concept of ‘creative destruction’ can help us understand why some women ascend to leadership positions. Using empirical research and anecdotal evidence from the experiences of several high-profile female executives, we argue that women may rise to leadership positions in turbulent environments that are receptive to new talent and open to innovative, bold ideas. Further, we propose that under these conditions women may be seen as especially attractive candidates to guide organizations because they are perceived to utilize a leadership style that promotes openness and inclusion, and facilitates change.
Measurements and calculations of neutron spectra from 35 MeV deuterons on thick lithium for the FMIT facility

Neutron yields and energy spectra were measured for 35 MeV deuterons on a thick target of natural lithium. Data were obtained using the time-of-flight technique over an angular range of 0/sup 0/ the 150/sup 0/ and for neutron energies from about 1 to 50 MeV. A simple nuclear model that describes the differential cross sections of neutron production was adjusted to agree with these new thick target data. Different model parameters were obtained when the model was adjusted to agree with previous ORNL thick target data for 40 MeV deuterons. Our experimental data are in good agreement with model predictions based upon the ORNL time-of-flight data but are somewhat lower than predictions based upon the ORNL dosimetry data. Finally the model was used to predict the neutron spectrum at the position of highest flux in the FMIT test cell.
Multicultural Shared Leadership A Conceptual Model of Shared Leadership in Culturally Diverse Teams

This conceptual article reviews relevant literature to develop propositions forming a model of multicultural shared leadership. First, an examination of the definitions of culture finds consensus o...
Analysis of multiphase polycarbonate polymerization in a semibatch reactor

Abstract A physical and chemical model that describes the interfacial condensation of bisphenol-A to polycarbonate in a multiphase gas-liquid-liquid semi-batch reactor is presented. The particular polymerization kinetics model consists of initiation, propagation and termination reactions between dissolved bisphenol-A monomer, phosgene gas, a phenolic polymer chain growth stopper and various resulting polymer species. Using these kinetics, a physical model for a semi-batch stirred tank reactor is developed. The model accounts for finite liquid-liquid and gas-liquid mass transfer resistances and includes either plug-flow or complete backmixing of the gas bubbles as options for the gas flow pattern. The model equations are solved using the z -transform method from which the polymer MWD and the moments of the polymer MWD are obtained. The utility of the model as a quantitative means of assessing the effect of various kinetic and transport parameters on the polymer MWD is examined for a particular case.
Structure-driven algorithms for truth maintenance

Abstract This paper studies truth maintenance and belief revision tasks on singly-connected structures for the purpose of understanding how structural features could be exploited in such tasks. We present distributed algorithms and show that, in the JTMS framework, both belief revision and consistency maintenance are linear in the size of the knowledge-base on singly-connected structures. However, the ATMS task is exponential in the branching degree of the network. The singly-connected model, while restrictive, is useful for three reasons. First, efficient algorithms on singly-connected models can be utilized in more general structures by employing well-known clustering techniques. Second, these algorithms can serve as approximations or as heuristics in algorithms that perform truth maintenance on general problems. Finally, the analysis provides insights for understanding the sources of the computational difficulties associated with JTMS and ATMS.
The effect of a protocol of aggressive donor management: Implications for the national organ donor shortage.

Background:The disparity between the number of people awaiting organ transplantation and the number of organs available has become a public health crisis. As many as 25% of potential donors are lost as a result of cardiovascular collapse (CVC) before organ harvest. A policy of aggressive donor manag
Autoantibodies to Nuclear Lamin C in the Eosinophilia—Myalgia Syndrome Associated with L-Tryptophan Ingestion

Objective. To examine the autoantibodies (antinuclear antibodies [ANA]) present in serum from a patient with eosinophilia—myalgia syndrome (EMS). Methods. Sera obtained during the early phase of EMS and following therapy with prednisone were screened by indirect immunofluorescence on HEp-2 cells, and ANA were characterized by immunoblotting on a purified nuclear lamin fraction. Results. ANA with a ring-like pattern of nuclear staining were identified at high titer by immunofluorescence, and immunoblotting experiments showed them to be directed against lamin C. The antibody titer declined dramatically after discontinuation of L-tryptophan and therapy with prednisone. Conclusion. This is the first characterization of an antigen/autoantibody system associated with EMS. The findings indicate that this EMS-associated autoantibody recognizes epitopes localized in the carboxyterminal region of lamin C. The occurrence of antilamin C autoantibodies in one EMS patient expands the spectrum of clinical conditions associated with these antibodies, and provides evidence for an autoimmune response in EMS.
Morphological responses of crop and weed species of different growth forms to ultraviolet-B radiation

Recent evidence of a general, global decline of stratospheric ozone has heightened concern about possible ecological consequences of increases in solar ultraviolet-B (UV-B, 280-320 nm) radiation resulting from ozone depletion. The influence of UV-B radiation (280-320 nanometers) on the morphology of 12 common dicot and monocot crop or weed species was examined to determine whether any common responses could be found that might, in turn, be useful in predicting possible changes in competitive balance under solar UV-B enhancement. Under glasshouse conditions, UV-B exposure (simulating a 20% reduction in stratospheric ozone at Logan, Utah) was found to reduce leaf blade and internode lengths and increase leaf and axillary shoot production in several species. Overall, the directions of these trends were similar in the majority of species that exhibited a significant response. These morphological changes occurred without any significant reduction in total shoot dry matter production. There was no clear distinction in the response of crops and weeds, though monocots were found to be generally more responsive than dicots. Previous work in dense canopies has shown that the photomorphogenetic effects of UV-B alter leaf placement and thereby influence competition for light. Our results suggest that, under these conditions, changes in competitive balancemore » resulting from increased UV-B might be expected more frequently when monocots are involved in mixtures, rather than mixtures of only dicots.« less
Stale Prices and Strategies for Trading Mutual Funds

We demonstrate that an institutional feature of numerous mutual funds—funds managing billions in assets—generates fund net asset values that reflect stale prices. Because investors can trade at these NAVs with limited transaction costs in many cases, obvious trading opportunities exist. These opportunities are especially prevalent in funds that buy Japanese or European equities. Simple, feasible strategies generate Sharpe ratios (excess return divided by standard deviation) that are many times greater than the Sharpe ratio of the underlying fund. We illustrate the potential of the strategy for three Vanguard Group mutual funds. A particular issue to keep in mind is that when the strategies are implemented, the gains from these strategies are matched by offsetting losses incurred by buy-and-hold investors in these funds.
Papillomatous digital dermatitis spirochetes suppress the bovine macrophage innate immune response

Papillomatous digital dermatitis (PDD) is a polymicrobial infection in soft tissue adjacent to the hoof and is the leading cause of lameness in dairy cattle. Treponema phagedenis-like (TPL) spirochetes are a constant feature of PDD lesions and are localized deep in infected tissue. Host-cell response mechanisms to TPL spirochetes are poorly understood. To assess how bovine macrophages respond to cellular constituents of TPL spirochetes, changes in transcription were analyzed using serial analysis of gene expression (SAGE) and real time RT-PCR. This analysis revealed that some proinflammatory cytokines (e.g. GCP-2 and IL-8) are induced in treated macrophages, while receptors and their accessory proteins for IL-1, IL-6 and IL-11 are either down regulated or unchanged. Two genes encoding proteins having negative effects on NFkappaB, IkappaB and SIVA-1, are significantly induced in stimulated cells. Several genes associated with the cytoskeleton and antigen presentation are down regulated after exposure to sonicated TPL spirochetes, as are genes associated with wound repair. Combined, these data suggest that the innate immune and wound repair functions of bovine macrophages exposed to TPL cellular constituents are impaired thereby enabling bacteria to resist clearance and induce lesion formation. Use of this in vitro bovine macrophage model should be useful in elucidating host-spirochete interactions and facilitate identification of potential virulence traits.
Imaging Of An Object Behind Randomly Distributed Particles

We present experimental studies of the imaging of an object behind randomly distributed spherical particles using coherent illumination. The object which has black stripes on white diffuse paper with different spatial wavelengths is placed behind a scattering cell and illuminated by an expanded HeNe laser beam. Results are obtained for different particle sizes and optical distances. The differences between the front and back illumination are studied. The diffusion approximation is used to calculate the modulation transfer function for the front illumination.
Persistent Difference in Short-Term Memory Span Between Sign and Speech Implications for Cross-Linguistic Comparisons

Short-term memory (STM) is thought to be limited in capacity to about 7 ± 2 items for linguistic materials and 4 ± 1 items for visuospatial information (Baddeley & Logie, 1999; Cowan, 2001). Recently, we (Boutla, Supalla, Newport, & Bavelier, 2004) challenged this dichotomy between linguistic and visuospatial STM by showing that STM capacity in users of American Sign Language (ASL) is also limited to about 4 or 5 items. This finding suggests that although longer spans appear for speech, spans are not necessarily longer for linguistic materials across all modalities. Wilson and Emmorey (2006) responded that because we evaluated span using digits for English speakers and letters for ASL signers, the difference we reported might have stemmed from stimulus selection rather than language modality. Here we address this claim by reporting an experiment in which we reexamined STM span in English speakers using letters and compared the outcome with results we and Wilson and Emmorey have obtained for ASL signers. It is important to note that the discrepancy between our previous results and those of Wilson and Emmorey is not in the obtained span in signers found by all parties to be around 4 to 5 items (Fig. la). Rather, Wilson and Emmorey disputed whether the digit span of 7 ± 2 in speakers is an appropriate benchmark for comparison with signers. Using letters to measure span in speakers, they found a span of only 5.3, comparable to that of signers. They suggested that there is no difference in span between the two languages. Here we show that their result is not due to their use of letters instead of digits. Rather, in selecting letters that are translations of one another in English and ASL, Wilson and Emmorey failed to control the stimuli in each language for phonological factors known to affect span size. One such crucial factor is phonological similarity. The finding that span is longer for digits than for letters in English speakers is not new (Cavanaugh, 1972). However, this difference has been attributed to the greater phonological similarity of letter names than digit names in English (Conrad & Hull, 1964; Mueller, Seymour, Kieras, & Meyer, 2003). In our previous study, we used letters with signers and digits with speakers to match stimuli in this important regard. Finger-spelled letters are less phonologically similar than number signs in ASL and therefore are more comparable to digits in English speakers. To demonstrate that there is nothing special about letters versus digits, other than the fact that many letter names are highly similar in English (e.g., bee, dee, ee, gee) and thus prone to produce shorter spans, we show here that when phonologically controlled letter materials are used with English speakers, the span of speakers returns to the typical 7 ± 2 range and continues to contrast with the span of signers.
Genetic distinctiveness of Ligumia recta, the black sandshell, in the Mobile River Basin and implications for its conservation

North America’s freshwater mussels are widely regarded as one of the most diverse and imperiled groups on earth, and many of the continent’s ~ 300 Unionidae and Margaratiferidae are drainage or regional endemics. Although Ligumia recta is currently widespread and stable in the Mississippi Basin, recent surveys suggest it is extirpated from the Pearl River drainage and only small populations persist in isolated Mobile River Basin tributaries. We compared 504 base pairs of the cytochrome c oxidase 1 mitochondrial gene from two Mobile Basin L. recta specimens and found that the Mobile Basin appears to support an evolutionarily significant genotype that could warrant recognition as a cryptic and highly imperiled taxon. Genetic data are beginning to reveal the extent and magnitude of recent biodiversity losses in the southeastern US, and moreover, these data will be critical to tailoring conservation and management strategies.
Noise reduction of bended differential transmission lines using compensation capacitance

In this paper, a novel technique to reduce the common mode noise of bended differential transmission lines is proposed. To this end, open circuited transmission lines are employed to compensate the undesirable capacitance of the bends. This method can remarkably decrease the differential to common mode conversion ratio in a very wide frequency range while offering an acceptable level of input return loss compared to un-compensated bended differential transmission lines. To present the effectiveness of this technique, time domain simulations have also been performed which show high level of common mode noise reduction offered by this method. This technique is examined on the right angle and 45 degree bended differential lines implemented inside microstrip and stripline structures.
1715 NEW METHODS FOR THE DIAGNOSIS OF VARIANT FORMS OF NEOROLIPIDOSIS

Most lysosomal storage diseases can be diagnosed by measuring the activity of a specific enzyme in an easily obtainable tissue sample. This can open the way to carrier identification in family members and prenatal testing when requested. A number of children and young adults with mental retardation, seizures and other clinical findings but normal enzyme values have been diagnosed as having a defect in sphingolipid catabolism by new techniques. Two additional types of patients with GM2 gangliosidosis have been identified. One type has a defect in hexosaminidase A (Hex A) not detectable with the usual fluorogenic substrate. The use of a sulfated synthetic substrate in the assay can make the diagnosis. Patients with a second variant type of GM2 gangliosidosis have normal Hex A levels but appear to be missing a required heat stable activator protein. Patients suspected of having GM2 gangliosidosis despite normal Hex A activity can be diagnosed by examining 1 ml of cerebrospinal fluid for gangliosides. Patients with normal arylsulfatase A activity have been demonstrated to excrete sulfatides and be unable to degrade 14C-sulfatide presented to their cultured cells. Their deficiency in a required sphingolipid activator protein (SAP-1) has been demonstrated using monospecific antibodies (Ab) in easily obtained tissue samples. When cultured cells from these patients were given 35S-methionine, and after 24 hrs they were lysed and treated with Ab, very little SAP-1 was produced.
The sun-exposed peel of apple fruit has a higher photosynthetic capacity than the shaded peel

To determine whether the sun-exposed peel of apple fruit has a higher photosynthetic capacity than the shaded peel, fruit peel samples were taken in both early July and early September from the exterior part of the canopy of mature 'Liberty'/M.9 trees for measuring oxygen evolution, key enzymes and metabolites involved in photosynthesis, and chlorophyll fluorescence. Compared with the shaded peel, the sun-exposed peel had higher light-saturated oxygen evolution rate and higher light saturation point, but lower apparent and true quantum yields. The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase, glyceraldehyde-3-phosphate dehydrogenase, phosphoribulokinase, stromal fructose-1,6-bisphosphatase, ADP-glucose pyrophosphorylase and sucrose-phosphate synthase (SPS) were higher in the sun-exposed peel than in the shaded peel on both sampling dates except that no significant difference was found in SPS activity between the two peel types in September. No significant difference was detected in the concentration of key metabolites (G6P, F6P, G1P, and PGA) between the sun-exposed peel and the shaded peel, suggesting that the response of the key enzymes to light exposure is well coordinated. Chlorophyll fluorescence quenching analysis showed that the sun-exposed peel had higher PSII quantum efficiency than the shaded peel at each given PFD, which resulted mainly from the higher photochemical quenching coefficient (qP). The sun-exposed peel had higher thermal dissipation capacity, as indicated by larger NPQ and Fo quenching, than the shaded peel at high PFD. In conclusion, the sun-exposed peel of apple fruit has higher activities of the Calvin cycle enzymes and higher rate of electron transport, leading to higher photosynthetic O2 evolution capacity. It appears that the acclimation of the Calvin cycle activities, thermal dissipation, and electron transport in apple peel are well coordinated in response to light exposure.
Interactions between the plasma and the stabilizing shell during disruptions in PBX-M

Abstract To stabilize vertical and external kink modes in the elongated, indented PBX-M plasma, a close-fitting stainless-steel-clad aluminum conducting shell surrounds over 85% of the plasma surface. During normal operation, the currents induced in the shell by the plasma are small, usually reflecting changes in plasma shape initiated by the shaping control system. However, voltage spikes of less than 2 kV were observed across gaps in the plates during both low-q and density limit disruptions. After the thermal quench, the plasma became unstable to the n = 0 vertical mode. The resulting rapid (20 to 5000 m/s, a resistive timescale) plasma motion induced large poloidal currents through segments of the shell to the vacuum vessel, despite the fact that each segment was electrically isolated except for a common single-point ground. Through impact loading, these large currents caused the failure of insulators and mechanical members in the shell support structure. These events have been numerically simulated with a resistive force-free halo plasma surrounding the main plasma, which provides a current path between the plates along open field lines. This model is consistent with measured plasma current decay times of 1–3 ms, characteristic of a resistive 10 eV plasma. Confirmation that the duration of the post-disruption plasma is about a resistive tearing time was provided from bolometers viewing both along the mid-plane and into the divertors. About 30–60% of the total energy and 30% of the magnetic energy was radiated during the thermal and current quench phases. This model led to improvements in the electrical configuration and insulator design which eliminated all failures. Disruptions have been prevented even when radiating over 100% of the input power during current profile control experiments with counter beam injection.
Nitrogen isotope biogeochemistry of the Antarctic Polar Frontal Zone at 170°W

Abstract During the US JGOFS AESOPS project, an intensive study was conducted of the nitrogen isotope biogeochemistry of the polar frontal region south of New Zealand and north of the Ross Sea. Repeated cruises and crossings of the study area permitted observation of the seasonal drawdown of NO 3 − and corresponding increases in δ 15 NO 3 − due to isotopic fractionation during phytoplankton uptake. Moored sediment traps placed at four locations crossing the polar front between 57° and 66°S provided a well-resolved time-series for both sinking particle flux and δ 15 N for comparison to water column results. Summertime increases in near-surface δ 15 NO 3 − at each site ranged from 1.2‰ to 2.8‰ and corresponded to reductions in surface [NO 3 − ] of 16% to 37%. Both seasonal variations in δ 15 NO 3 − as well as summertime vertical variations in the upper 100 m were used to estimate the fractionation factor ( e ). e ranged between 6‰ and 8‰ assuming closed system dynamics and 7‰ to 10‰ assuming open system dynamics. The lower range more likely reflects actual values for e since NO 3 − drawdown is closely associated with stratification of the upper water column and is similar to recent estimates for this region. Sinking particle δ 15 N varied with particle flux and ranged from −1‰ to 5‰. Average δ 15 N weighted by N fluxes were skewed toward summertime values, between −0.1‰ and 1.7‰. To compare with theoretical expectations, differences between average trap δ 15 N and the δ 15 N of NO 3 − prior to depletion (Δ δ 15 N) were calculated for each site. Observed Δ δ 15 N vs. relative surface NO 3 − utilization ( u ) for the four sites studied plotted at the upper envelope of the theoretical relationships for both closed and open system equations using observed ranges in e . The nitrogen isotopic signal transmitted to the sediments is quantitatively consistent with the degree of NO 3 − depletion in Southern Ocean waters. This comparison was also relatively insensitive to choice of open- or closed-system models due to the relative low values of u (0.2–0.4). These results validate previous interpretations of downcore δ 15 N in the polar Southern Ocean as evidence for a large increase in relative nutrient utilization during the last glacial maximum.
Fatty acid esterification by homogenates of bovine liver and adipose tissue.

Abstract Glycerol-3-phosphate, adenosine triphosphate, coenzyme A, MgCl 2 , and NaF were necessary cofactors for maximal esterification of palmitate-1- 14 by homogenates of bovine liver and adipose tissue. Dithiothreitol enhanced esterification in liver, but not in adipose tissue homogenates, whereas esterification was stimulated by bovine serum albumin in adipose but not hepatic tissue. Both systems incorporated palmitate, stearate, oleate, and linolenate into glycerides. Linoleate incorporation was scant by either system. Liver homogenates esterified a greater percentage of the fatty acids into phospholipids and monoglycerides than did adipose tissue. Triglycerides accounted for 55% of the product in adipose tissue and 18 to 44% in liver.
Electrophoresis with two buffers in one dimension in the analysis of glycosaminoglycans on cellulose acetate strips

Abstract We have systematically examined the electrophoretic behavior of hyaluronic acid, desulfated chondroitin, heparan sulfate, and chondroitin sulfate with two different buffers under varying conditions of buffer concentration, electrophoresis time, and voltage. An anodal effect was observed with barium acetate buffer in which the glycosaminoglycans behaved as if they became positively charged as they neared the anode, whereas with monovalent buffers the migration was nearly linear with time. Such differences in behavior permitted us to develop a two-buffer monodirectional electrophoresis technique which offers some of the advantages of resolution seen with two-dimensional methods, yet retains the advantages of band comparison and quantitative analysis characteristic of one-dimensional electrophoresis.
Impact of new connectology in reducing peritonitis

Summary: A computer initiated literature search for publications addressing the association between connectology and peritonitis in continuous peritoneal dialysis patients identified 23 relevant articles. These publications used one of four basic clinical research designs (before-after; single centre prospective cohort; multi-centre prospective cohort and randomized clinical trial). the methodologic weaknesses inherent in the first two designs significantly impaired the validity of their conclusions. the two multi-centre cohort studies and the five randomized clinical trials have external and internal validity, respectively. Combined, they suggest that the Y connector-disinfectant system and the twin bag systems are associated with less peritonitis than standard, ultraviolet and possibly the Y set without disinfectant. the effect is entirely due to decreased infection with Staphylococcus epidermidis and other organisms associated with touch contamination. Peritonitis due to these organisms does not cause significant loss of peritoneal dialysis catheters or transfer to haemodialysis. the decreased hospitalization due to fewer episodes of peritonitis will become less important with more outpatient antibiotic treatment of these mild infections. Significant improvement in the morbidity associated with peritoneal dialysis related infection will require effective strategies for prevention of infection due to Staphylococcus aureus and gram-negative organisms.
Sandstone Porosity--How Deep?: ABSTRACT

Sandstone porosity and permeability tend to decrease with depth. Controlling factors are complex and there is no accurate method of computing the depth to which commercially interesting porosities might extend. The optimistic view is that quartz is an exceedingly strong material and that short-time crushing experiments indicate that porosities persist to depths roughly double those drilled to date. Other experiments involving saline waters, elevated temperatures and pressures, and times measured in days, show that quartz sand is very much weaker than its theoretical strength and that failure and compaction is progressive over the longest times investigated. As in natural sandstones, experimental consolidation of quartz sands involves two distinct processes, compaction and cementation. Both are accelerated by high temperatures, moving water solutions, and large "overburden" pressures. Highest porosity might be expected for pure, well sorted and rounded sands of the type examined experimentally. Conditions resulting in porosity reduction in these sands to some minimum value,--say 15 per cent,--should produce similar or greater reduction in most oil sands. Assuming sands are water-bearing and depth is constant, then temperature is the most important variable affecting pore reduction. Experiments indicate the effects of time and temperature are interchangeable, the log of time being a linear function of absolute temperature. Compaction curves for dry quartz sand at room temperature and for saline water-saturated sands at pressures and temperatures simulating burial, are roughly parallel with trends of maximum porosities in natural sands. These trends seem to be temperature-dependent. If published temperature gradients for the Gulf Coast are accepted, then rough extrapolations indicate that pure quartz sands would be reduced to 15 per cent maximum porosity at depths less than 20,000 feet in the Galveston area and somewhat deeper, perhaps 25,000-27,000 feet, on the Mississippi Delta. These figures are for young Cenozoic sediments. Similar porosities should be attained at lesser depths within older formations. Scarcity of reliable temperature data sharply limits the accuracy of this type of analysis. Good temperature logs of a few deep wells within a region would be of great value in estimating deeper drilling possibilities. End_of_Article - Last_Page 363------------
VARIABILITY IN OXYGEN ISOTOPE COMPOSITIONS OF HERBIVORE TEETH : REFLECTIONS OF SEASONALITY OR DEVELOPMENTAL PHYSIOLOGY?

Abstract Oxygen isotope compositions of herbivore tooth enamel from two areas in Kenya were measured using a laser fluorination approach. Isotope heterogeneity was found within four sets of teeth in the jaws of different individuals (∼2‰), as well as within individual teeth. The rear molar (M3) of a zebra shows a 1.4‰ variability, whereas, the middle and rear molars (M2 and M3) of a gazelle show variations of 1.7 to 2.9‰. The front molar (M1) of a gazelle is relatively homogeneous (∼0.25‰). Compositional heterogeneities are spatially correlated, and comparison to theoretical models suggests that they largely reflect different times of tooth growth coupled with seasonal changes in forage composition, rather than developmental physiology. Spatially-specific enamel analysis combined with knowledge of genus-specific diet, water turnover, and physiology allows paleoclimate seasonality to be assessed.
Realizations of focus invariance in optical-digital systems with wave-front coding.

We report experimental verification of an extended depth of focus (EDF) system with near-diffraction-limited performance capabilities. Dowski and Cathey [Appl. Opt.34, 1859–1866 (1995)] described the theory of this system in detail. We can create an EDF system by modifying a standard incoherent optical system with a special cubic phase plate placed at the aperture stop. We briefly review the theory and present the first optical experimental verification of this EDF system. The phase plate codes the wave front, producing a modified optical transfer function. Once the image is transformed into digital form, a signal-processing step decodes the image and produces the final in-focus image. We have produced a number of images from various optical systems using the phase plate, thus demonstrating the success of this EDF system.
Kinetics and quantitative aspects of enhancement of influenza virus multiplication by 5-methyl-2-D-ribobenzimidazole (MRB).

Abstract In multiple cycle infection after a small inoculum, chorioallantoic membranes from 13-day-old chicken embryos produce one-tenth as much influenza B (Lee) virus per unit area as those from 7-day-old embryos. 5-Methyl-2- d -ribobenzimidazole, 3.5 m M , added at the time of infection, increases the yield from the older membranes by 650%, on the average, but has no effect or little effect in the younger membranes. After a large inoculum, membranes from 13-day-old eggs produce high yields, which can only be slightly increased by MRB. Treatment of 13-day-old chorioallantoic membranes with MRB either before or after infection increases Lee virus yield. Maximal enhancement is obtained when treatment is begun before infection and continued for a prolonged period after infection. Detailed examination of the kinetics of enhancement of virus production by MRB has shown that MRB requires several hours to act. However, once an effect has been established, MRB may be removed by washing, and an increased virus yield still obtained many hours later, although there is a decay in the effect with time. MRB is capable of increasing Lee virus yield in membranes in which it is restricted by treatment with reovirus RNA, poly I: C, cycloheximide, 5,6-dichloro-1-β- d -ribofuranosylbenzimidazole, or by dextrose deprivation. MRB also increases Lee virus yield in membranes from COFAL-negative eggs in which influenza virus multiplication is depressed. MRB causes moderate enhancement and virus, of the yield of influenza A/swine/15 slight enhancement of influenza A 1 /FM1 and A 2 /RI/2 viruses. No enhancement was observed with influenza A 0 /WS, A 0 /NWS, A 2 /RI/1, and A 2 /RI/3 viruses.