cssi/SciSciGPT-SciSciNet huggingface dataset:
A highly selective fluoroionophore for the detection of lithium ions

Abstract N-(9-methylanthracene)-25,27-bis(1-propyloxy)-4-tert-butylcalix[4]arene-azacrown-3 (I) was synthesized and tested as a fluoroionophore for the selective detection of lithium cations. The efficiency of photoinduced electron transfer in this fluoroionophore is sensitive to the presence of lithium ions. When exposed to lithium ions in a 75:25 (v/v) dichloromethane/THF solvent mixture, the molecule acted as an “off–on” fluorescence switch exhibiting a >106-fold enhancement in fluorescence emission intensity. Selectivity studies demonstrated that I effectively discriminates against sodium and potassium: log K Li , Na =−3.8 and log K Li , K =−2.3 .
Sibling manipulation and indirect fitness in termites

Various termite researchers have noted the presence of wing pad damage apparently due to bites inflicted by other colony members. Some have reported regression of nymphal development in response to the damage. I show that the kalotermitid species Pterotermes occidentis displays significant frequencies of damaged termites in mature (alate producing) colonies, but no damage in immature colonies. Damaged termites typically develop toward the worker form (Table 1). I hypothesize that workers are biting siblings to recruit more workers and thereby improve their indirect fitness.
Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends

Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975–2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs) were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus) and Golden Eagles (Aquila chrysaetos) showed the fastest rate of change, with 8.41 km yr−1 and 7.74 km yr−1 shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally change as species experience changes in distribution in response to climate change.
The management of breast carcinoma by primary radiotherapy at mount sinai hospital from 1962–1979

Two-hundred eight patients with carcinoma of the breast were treated with megavoltage irradiation as the primary method of local management at Mount Sinai Hospital between 1962-1979. The effects of treatment volume, technique, and other parameters are discussed for the Stage I and II patients, together with the importance of tumor size and nodal status in control of local disease and distant metastases. In this series the cumulative probability of freedom from metastases is 93 +/- 5% when the irradiation is confined to the breast and axilla as compared with 72 +/- 9% when extended fields are used, with no difference in local control. Based on these results it was decided to confine irradiation to the breast and axilla alone in the majority of early stage cancer patients. Recommendations are made for radiation techniques and dosages to optimize control of the disease, minimize complications, and facilitate systemic therapy in patients with positive nodes.
Preliminary evidence for top-down and bottom-up processes in web search navigation

In current theories of web navigation, link evaluation has been treated primarily as a bottom-up process involving assessing the semantic distance between a search goal and a given link in the information source. In this paper we investigate whether link evaluation could be subject to top-down influence from knowledge of the information source. We measured fixation durations that occurred during link evaluation and found shorter durations in the search for easy goals. This preliminary finding suggests that for goals with category names readily retrievable from knowledge of the information source, search is likely aided by top-down influences.
Osteoporosis prevention: pediatricians' knowledge, attitudes, and counseling practices.

Abstract Background. Strategies to prevent adult osteoporosis are best undertaken during childhood and adolescence, when the greatest amount of bone mineral density is acquired. This study examines pediatricians' knowledge and practices regarding osteoporosis prevention. Methods. One hundred eighty-seven primary care pediatricians from San Diego and Imperial Counties responded to a 44-item mailed survey that measured physician knowledge, attitudes, and practices regarding osteoporosis prevention. Results. Knowledge of U.S. RDA for calcium in children and adolescents was limited, with only 23.7 and 32.3% of pediatricians correctly identifying the recommended values for children and adolescents, respectively. Thirty-eight percent of respondents regarded osteoporosis prevention to be an important issue, and less than half reported that they counseled patients for osteoporosis prevention. Of those pediatricians who did perform osteoporosis counseling, the two most frequently cited motivators for counseling were that counseling is recommended by professional boards and having a personal or professional interest in osteoporosis prevention. The most commonly reported barriers to counseling were other issues taking greater priority and having insufficient time to undertake counseling for osteoporosis prevention. Conclusions. Osteoporosis prevention should begin in childhood and adolescence. This study suggests that many pediatricians do not counsel patients to reduce osteoporosis risk, nor do they consider this an important issue. Furthermore, they may not have full knowledge about how to prevent osteoporosis.
The Effect of Acute Cocaine or Lidocaine on Behavioral Function following Fluid Percussion Brain Injury in Rats

One of the goals of our laboratory is to examine how the presence of drugs of abuse will influence traumatic brain injury. Previous studies in our laboratory have shown that cocaine or lidocaine treatment before experimental fluid percussion brain injury in rats reduces the cortical hypoperfusion normally found in the early posttraumatic period. The purpose of the current study was to determine if pretreatment with cocaine or lidocaine is also associated with changes in trauma-induced suppression of reflexes and motor and cognitive dysfunction that occurs following traumatic brain injury (TBI). Twenty-four hours after surgical preparation, rats were randomly assigned to a saline or drug pretreatment group, cocaine (0.5, 2, or 5 mg/kg) or lidocaine (2 mg/kg), which was injected via the tail vein. None of the drug pretreatments worsened injury. Lidocaine and cocaine decreased the duration of suppression of some neurological reflexes and reduced posttraumatic body weight losses. Lidocaine and cocaine both decreased postinjury motor deficits. Lidocaine and cocaine did not affect cognitive function on days 11-15 postinjury. The mechanism by which lidocaine improves acute neurological and motor function following brain injury is unknown, but may involve improved posttraumatic cortical blood flow, as seen in our previous study. Our results, along with other studies showing lidocaine to be neuroprotective in animal models of ischemia, suggest that studies of the effect of posttraumatic administration of lidocaine are warranted
A generalized self-dual Chern-Simons Higgs theory

In the recently discovered Chern-Simons model, the reduction to a Bogomol'nyi bound or self-duality depends crucially on the specific form of the Higgs potential energy function, which is characterized by a φ6 type self-interaction. The purpose of this paper is to show that a much wider class of Higgs self-interaction may be allowed to achieve self-duality provided that the kinetic energy term of the Higgs scalar is suitably modified. The existence of topological multivortex solutions is also established. Furthermore, it is remarked that the Meissner effect may occur in the model.
Making the invisible visible: professional education to eliminate disparities in clinical trials.

It is important to remember the basic organizational and behavioral principles that (1) we cannot address problems of which we are unaware, and (2) knowledge alone is never enough to create change. Meaningful change requires commitment at both institutional and individual levels. Using the EDICT Policy Recommendations together with the Clinical Trials BackPack and CLAS-ACT resources will enable clinical research training programs to (1) increase awareness of clinical trials disparities, (2) provide professional education about how to increase recruitment and retention of underrepresented groups, and (3) actually implement concrete activities that can change the face of clinical trials research. By doing so, perhaps it will not require another 50 years to eliminate disparities in clinical trials.
Identification of the biliary metabolites of 2,3,7,8-tetrachlorodibenzofuran in the rat

Abstract Metabolism of 2,3,7,8-tetrachlorodibenzofuran (TCDF) has been investigated in the F344 rat. Biliary metabolites were treated with glucuronidase/sulfatase, methylated, and the methyl ethers thus obtained were compared to synthetic standards by gas chromatography/mass spectrometry. It has been determined that 4-hydroxy-2,3,7,8-tetrachloro- and 3-hydroxy-2,7,8-trichlorodibenzofuran are the major biliary metabolites. Evidence was also obtained for the presence of other metabolites and unmetabolized TCDF. Possible metabolic pathways leading to these compounds are discussed.
Protagonistic pleiotropy: Why cancer may be the only pathogenic effect of accumulating nuclear mutations and epimutations in aging.

Abstract Since Szilard's seminal 1959 article, the role of accumulating nuclear DNA (nDNA) damage – whether as mutations, i.e. changes to sequence, or as epimutations, i.e. adventitious but persistent alterations to methylation and other decorations of nDNA and histones – has been widely touted as likely to contribute substantially to the aging process throughout the animal kingdom. Such damage certainly accumulates with age and is central to one of the most prevalent age-related causes of death in mammals, namely cancer. However, its role in contributing to the rates of other aspects of aging is less clear. Here I argue that, in animals prone to cancer, evolutionary pressure to postpone cancer will drive the fidelity of nDNA maintenance and repair to a level greatly exceeding that needed to prevent nDNA damage from reaching levels during a normal lifetime that are pathogenic other than via cancer or, possibly, apoptosis resistance. I term this the “protagonistic pleiotropy of chromosomal damage” (PPCD) hypothesis, because this interaction of cancer-related and -unrelated damage is the converse of the well-known “antagonistic pleiotropy” phenomenon. I then consider a selection of recent data on the rate of accumulation of nDNA damage in the context of this hypothesis, and conclude that all presently available evidence is consistent with it. If this conclusion is correct, the implications for the feasibility of greatly postponing mammalian (and eventually human) aging and age-related pathology are far-reaching.
Ultralow power nonlinear optics in Rb-filled band-gap fibers

We describe our recent results on the ultralow nonlinear interactions of Rb atoms in hollow-core photonic-bandgap fibers and show that large optical densities can be generated at room temperature through the process of light-induced atomic desorption.
Electrokinetic Remediation. III. Enhancement with Base

Abstract One-dimensional models are developed for simulating the base-enhanced electrokinetic treatment of aquifers contaminated with As(V) and Zn(II). The effect of the fraction of H± generated electrolytically at the anode which is neutralized on the time required for remediation is investigated. The effect of the initial speciation of the contaminant [As(V) or Zn(II)] is also explored. Base-enhanced electrokinetic treatment is expected to be useful in the removal of anionic species (arsenate, selenate, fluoride, for example) and in the removal of amphoteric metal ions (lead, zinc, chromium, etc.) from aquifers containing large concentrations of calcium or magnesium carbonate which would interfere with acid-enhanced electrokinetic treatment. ∗ Current address: Eckenfelder, Inc., 227 French Landing Drive, Nashville, Tennessee 37228.
Girdling by notodontid caterpillars: distribution and occurrence

Girdling insects produce a circular groove around a stem or petiole typically before ovipositing or feeding on the distal section. We documented that seven of the 11 species of notodontid caterpillars that we studied, including members of five genera in two subfamilies, chewed girdles in seven families of trees including species of birch, hickory, oak, elm, cherry, willow, and maple. The frequency of girdling varied with notodontid species, tree species, month, and year. Free-ranging final instar larvae of Schizura leptinoides on pecan (Carya illinoensis) spent 4–11 % of their time cutting and reinspecting girdles over 5-h and 12-h observation periods. Feeding occurred proximal as well as distal to girdles, a result not expected by most hypotheses for the function of girdling. Histological examination of S. leptinoides girdles on river birch (Betula nigra) revealed that only the xylem remained intact; however, on pecan, both the xylem and phloem remained mostly uncut by the girdle. S. leptinoides larvae often rubbed their mouthparts over the surface of finished girdles, anointing them with fluid from the labial salivary glands or possibly the ventral eversible gland. After feeding, S. leptinoides and other notodontids sometimes severed the petiole even when the leaf was only partially eaten; these leaf-clipping larvae were similarly observed rubbing their mouthparts over the severed petiole stub. We propose that notodontids cut girdles and clip leaves at least in part to introduce secretions or their enzymatic products into the vascular system to suppress host defenses and/or enhance nutrition.
Electrophysiological and behavioral correlates of arousal

The relationships among levels of activity, responsiveness, exploration, and cortical arousal were assessed in a group of similarly reared male rats from a strain that was highly inbred to maximize genetic homogeneity. In Experiment 1, 22 subjects were tested in a complex, compartmentalized open field (i.e., a closed field), and those falling approximately 1 SD above or below the group activity mean (eight were eliminated) were designated as high- or low-active, implanted with electrodes, and tested electrophysiologically to ascertain the level of cortical arousal as determined via measurements of visually evoked potential afterdischarge amplitude. High-active subjects demonstrated a significantly lower afterdischarge amplitude, indicating that behavioral arousal may be indexed by a readily quantifiable electrophysiological measure. A second group of 14 rats (Experiment 2) was tested and retested after 45 days in the closed field, estabhshing that high- or low-behavioral responsiveness is a stable characteristic. Subjects then received 2 days’ exposure to one of two dissimilar compartments of an exploratory apparatus and were tested to determine amount of time spent in the familiar vs. novel compartments. High-active rats were found to demonstrate significantly shorter initial response latencies. However, no other differences were found. These rats were next tested in a completely open field. No significant activity differences were discovered. These findings show that a high level of arousal as a response to a highly complex environment or intense stimulation is not related to generalized activity elicited in a low-complexity environment (e.g., the open field). These findings also indicate that similarly reared rats may be differently influenced by novel, complex, or intense stimuli, such that some subjects become highly responsive and cortically aroused, whereas others respond with low levels of behavioral and cortical activation. The findings are discussed in terms of cortical and subcortical mechanisms mediating arousal.
The growth of InP1-xSbx by metalorganic chemical vapor deposition

InP1-xSbx was grown by metalorganic chemical vapor deposition under a variety of conditions. The V/III vapor phase ratio was varied from 327 to 12 over a temperature range of 450–525°C, at pressures of 77 to 660 Torr and growth rates of 0.30 to 2.0 μm/h. For some samples, the V/III vapor phase ratio was optimized for InP1-xSbx lattice matched to InAs to give smooth morphologies and lattice matching with a minimized variation of composition versus changes in the TMSb/(TMSb+PH3) ratio. Examination by transmission electron microscopy indicates that the materials are not single phase, but have undergone a spinodal decomposition, which is consistent with thermodynamic calculations. When our specimen compositions are corrected for strain relaxation, the infrared photoluminescence measurements indicate a lower energy photoluminescence peak for these materials than had been previuosly reported in the literature. Infrared absorption and photoconductivity measurements indicate no sharp band edge as would be expected for a direct gap semiconductor. The observed broad spectra are consistent with alloy decomposition.
Induction of synaptic development in cultured muscle cells by basic fibroblast growth factor.

Abstract The role of basic fibroblast growth factor (bFGF) in signaling the development of the neuromuscular junction was examined. Beads coated with bFGF induced the formation of acetylcholine receptor (AChR) clusters in cultured Xenopus myotomal muscle cells. Tyrphostin, a tyrosine kinase inhibitor, abolished AChR clustering induced by bFGF beads, suggesting a role of tyrosine kinase activation in AChR clustering. Using specific antibodies, we demonstrated the presence of both bFG F and its receptor in the myotomal muscle in vivo during the period of neuromuscular connection. However, similar tissue from older animals with mature neuromuscular junctions showed an apparently truncated form of the bFGF receptor. These data suggest that bFG F may play a role in signaling synaptogenesis in skeletal muscle.
Conditionally Averaged Dynamics of Turbulence

The conditionally averaged Navier-Stokes equations with fixed vorticity in a point are considered. It is found in particular that the conditionally averaged rates of vortex stretching and dissipation increase exponentially with the vorticity magnitude. The local imbalance of these effects leads to the formation and destruction of twisted vortex strings.
Constructing a collagen hydrogel for the delivery of stem cell-loaded chitosan microspheres.

Multipotent stem cells have been shown to be extremely useful in the field of regenerative medicine1-3. However, in order to use these cells effectively for tissue regeneration, a number of variables must be taken into account. These variables include: the total volume and surface area of the implantation site, the mechanical properties of the tissue and the tissue microenvironment, which includes the amount of vascularization and the components of the extracellular matrix. Therefore, the materials being used to deliver these cells must be biocompatible with a defined chemical composition while maintaining a mechanical strength that mimics the host tissue. These materials must also be permeable to oxygen and nutrients to provide a favorable microenvironment for cells to attach and proliferate. Chitosan, a cationic polysaccharide with excellent biocompatibility, can be easily chemically modified and has a high affinity to bind with in vivo macromolecules4-5. Chitosan mimics the glycosaminoglycan portion of the extracellular matrix, enabling it to function as a substrate for cell adhesion, migration and proliferation. In this study we utilize chitosan in the form of microspheres to deliver adipose-derived stem cells (ASC) into a collagen based three-dimensional scaffold6. An ideal cell-to-microsphere ratio was determined with respect to incubation time and cell density to achieve maximum number of cells that could be loaded. Once ASC are seeded onto the chitosan microspheres (CSM), they are embedded in a collagen scaffold and can be maintained in culture for extended periods. In summary, this study provides a method to precisely deliver stem cells within a three dimensional biomaterial scaffold.
Influence of fetal alcohol exposure on the GABAergic regulation of growth hormone release in postnatal rats.

Background: Disruption of the growth hormone (GH) axis by maternal ethanol (ETOH) consumption may contribute to abnormalities in offspring. Interestingly, γ-aminobutyric acid (GABA) neurotransmission, which is vulnerable to fetal ETOH exposure, also regulates the hypothalamic-pituitary GH axis. This study examines whether GABAergic control of this axis is disrupted by prenatal ETOH exposure. Methods: Pregnant dams were fed either rat chow ad libitum or a 36% ETOH diet (by calories), or wcre pair-fed an isocaloric control diet. Hypothalami and pituitarics from offspring were copcrfused, in vitro, with muscimol, a GABAA agonist, either alone or in combination with bicuculline, a GABAA antagonist. Perfusatcs werc analyzed by radioimmunoassay for GH, somatostatin (SRIF), and GH-releasing factor (GRF). Results: Normal development of GABA regulation was evaluated first in control offspring. Sensitivity to muscimol (measured by percent increase in GH above basal levels) occurred at all ages and generally was greater in male compared to female tissue. Furthermore, the efficacy of bicuculline in depressing muscimol-induced GH secretion increased with age in both sexes. In males, this response correlated with increased SRlF rclease. In females, releasing factor data were highly variable relative to the percent change and are not presented. Maternal ETOH consumption altered the development of GABAergic regulation of the GH axis in offspring. However, because ETOH induced changes in the response of releasing factors to muscimol appcar to offset each other, a disruption in GH release was not evident. More apparent was the reduced capacity of bicucullinc to reverse muscimol-induced GH release from male tissue. This ETOH effect was evidcnt at 35-days of age and was associated with reduced SRIF release. In female tissue, a reduced bicuculline response was also suggested at 35 days of age. After puberty no response was elicited by muscimol in either tissue from pair-fed or ETOH-exposed female offspring. Conclusion : In summary, fetal ETOH exposure influences the development of GABAergic regulation of the hypothalamic-pituitary GH axis in an age and gender specific manner. Vulnerability of the male axis is expressed by the reduced capacity of bicucullinc to depress GH rcleasc and altered releasing factor sensitivity to GABAA-receptor stimulation or inhibition. There is also some suggestion that the female axis is less sensitive to bicuculline during early puberty, and, unlike the male, is insensitive to both muscimol and bicuculline after puberty. The latter, however, may be attributable to stress or nutritional deprivation, rather than to the direct effect of prenatal ETOH.
A comment on: Regular structures of the solar photosphere

A recent Letter to the Editor (Getling & Brandt [CITE]) suggests that solar granulation is not entirely random, instead showing large scale spatial and long term temporal coherence. The authors cite as evidence the persistence of bright granular size objects in images even after long term temporal averaging, the reoccurrence of bright granules in time series at locations of local maxima in the average image, and the presence of large scale regular structures in time-average images. This paper demonstrates that all three of these observations are consistent with a completely random and changing flow pattern and do not require self organization of the granular flows.
Comments on Samal and Henderson: :20parallel consistent labeling algorithms”

Samal and Henderson claim that any parallel algorithm for enforcing arc consistency in the worst case must have Ω(na) sequential steps, wheren is the number of nodes, anda is the number of labels per node. We argue that Samal and Henderson's argument makes assumptions about how processors are used and give a counterexample that enforces arc consistency in a constant number of steps usingO(n[su2a22na) processors. It is possible that the lower bound holds for a polynomial number of processors; if such a lower bound were to be proven it would answer an important open question in theoretical computer science concerning the relation between the complexity classesP andNC. The strongest existing lower bound for the arc consistency problem states that it cannot be solved in polynomial log time unlessP=NC.
Effects of thermal trauma on dog erythrocyte ATPase and shape.

Abstract Studies have been carried out on dog erythrocytes to determine the effects of heating to 57°C on membrane ATPase and erythrocyte shape. The results of these studies showed that after heating the blood there was approximately a 30 per cent decrease in membrane ATPase and an alteration of erythrocyte shape from biconcave to spherical. Additional studies of the effects of addition of arachidonic acid to erythrocyte-membrane homogenates demonstrated that this substance produced a dose-related inhibition of ATPase. If the additions were made to membranes from blood which had previously been heated, the effects of arachidonic acid and heat were additive. Addition of the hydroxyl-radical scavenger catalase to the blood before heating prevented the observed decrease in ATPase and prevented the change in shape to spherical. These results confirm the previous findings of Bessis that heat will cause a change in the erythrocyte shape from biconcave to spherical and suggest that the mechanism responsible for this change is an alteration in membrane ATPase. The observation that a similar response can be produced by arachidonic acid suggests that metabolism of this substance may generate agents which are capable of inhibiting erythrocyte membrane ATPase. The observation that catalase will prevent the ATPase inhibition and the change in erythrocyte shape suggests that hydroxyl-free radicals play an important part in this thermal trauma-induced response.
FoodRoutes Network and the Local Food Movement

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Ionization Energies of the Singly Ionized Rare Earths

Values of the ionization energies of the singly ionized rare earths have been obtained by means of a semiempirical calculation. The results in eV are:La ii11.06Sm ii11.07Ho ii11.80Ce ii10.85Eu ii11.25Er ii11.93Pr ii10.55Gd ii12.1Tm ii12.05Nd ii10.73Tb ii11.52Yb ii12.17Pm ii10.90Dy ii11.67Lu ii13.9The uncertainty is estimated to be ±0.08 eV except for Gd ii and Lu ii where the estimated uncertainty is ±0.4 eV.
Modeling the growth and interaction of multiple dendrites in solidification using a level set method

Abstract A level set method is presented to study the growth and interaction of multiple dendrites in solidification. The method couples thermal and solute diffusion with propagation of multiple interfaces. A single signed distance function is used to track the solid–liquid interface with the aid of markers, the value of which is the orientation angle, for identification of different crystals. The problem of evolving multiple crystal interfaces is reduced to two tasks: (1) tracking one level set variable (signed distance function) and (2) determination of the marker for a newly solidified finite element nodal point. Tracking a single level set variable is implemented by solving the level set equation with interface velocity computed from an extended Stefan equation using the marker information (crystal orientation). Determination of the marker for a newly solidified finite element nodal point is implemented by using an algorithm modified from the fast marching technique. Both of these two steps are computationally efficient and the approach is suitable for incorporating effects of multiple crystals. Convergence and accuracy of this approach are demonstrated by using different grid spacings and comparing with results obtained from the multi-phase level set method. A parametric study is performed to investigate the effects of solidification speed and thermal gradient on the resulting solidification microstructure pattern. Numerical results of columnar-to-equiaxed transition (CET) qualitatively agree with an analytical estimation and are similar to previous numerical results obtained using a phase field method. A convergence study is performed to determine the appropriate grid spacing for numerical simulation. At lower surface tension, CET occurs at a lower thermal gradient for a giving solidification speed. Secondary dendrite formation is more apparent with lower surface tension. The differences and similarities between the three-dimensional and two-dimensional growth results are analyzed. Randomness in crystal orientation and required undercooling for nucleation are modeled and found to have a great effect on the microstructure pattern. The efficiency of the present approach is finally demonstrated with an example that includes the growth of hundreds of crystals with consideration of randomness effects.
Shape Transition of Germanium Nanocrystals on a Silicon (001) Surface from Pyramids to Domes

Chemical vapor deposition of germanium onto the silicon (001) surface at atmospheric pressure and 600 degrees Celsius has previously been shown to produce distinct families of smaller (up to 6 nanometers high) and larger (all approximately 15 nanometers high) nanocrystals. Under ultrahigh-vacuum conditions, physical vapor deposition at approximately the same substrate temperature and growth rate produced a similar bimodal size distribution. In situ scanning tunneling microscopy revealed that the smaller square-based pyramids transform abruptly during growth to significantly larger multifaceted domes, and that few structures with intermediate size and shape remain. Both nanocrystal shapes have size-dependent energy minima that result from the interplay between strain relaxation at the facets and stress concentration at the edges. A thermodynamic model similar to a phase transition accounts for this abrupt morphology change.
Factors Affecting Metabolism of Commercial Channel Catfish Ponds as Indicated by Continuous Dissolved Oxygen Measurement

Continuous dissolved oxygen (DO) measurements were analyzed to evaluate the rates of pond metabolic processes related to productivity and respiration in three commercial catfish ponds in northwest Mississippi. Multiple regression models were constructed to assess the relative importance of various forcing functions on indices of net primary productivity (NPP) and whole pond respiration (WPR), duration of automated aeration, and DO concentration below various threshold values. Water temperature, solar radiation, wind run, cumulative feed, and lagged values of these parameters were considered as forcing functions. Generally, NPP and WPR were most strongly affected by water temperature and only weakly related to solar radiation. The duration of nightly aeration was also strongly related to water temperature, although 10-d cumulative feed was an important predictor in one pond. The best predictors of duration of DO below certain threshold values were NPP, WPR and wind run, the importance of which varied depending upon the pond and the threshold value considered. Change in feeding rate from one day to the next was inversely related to feeding rate on the previous day. The results of this analysis suggest that NPP and WPR rates, and the duration of required nightly aeration in commercial catfish ponds are controlled by factors not amenable to practical management control.
Light, electron, and confocal microscopic study of the mouse superior mesenteric ganglion

The superior mesenteric ganglion (S.m.g.), a sympathetic prevertebral ganglion, is an integrating center for gastrointestinal reflexes. Many details of its structure are still lacking. In the present study, mouse S.m.g. neurons were studied by light, electron, and confocal microscopy. Neurons had an average of 5-6 primary dendrites. Total dendritic length averaged 963 microns. Confocal microscopy and three-dimensional reconstructed images revealed cell body surface features, precise location where axons and dendrites emerged from it, cell body size, and extent of dendritic projection in three axes. Cell body diameter and dendritic projections were less in the dorsoventral than in the rostrocaudal or mediolateral axes. Cell body surface area and volume averaged 4,271 microns 2 and 4,908 microns 3, respectively. Dendritic surface areas and volumes were 5-6 times larger. Two main neuron types (projecting caudally or rostrally) were distinguished. The former were found throughout the S.m.g., whereas the latter were found only in the cephalad region, comprising about 40% of neurons found there. Rostrally projecting neurons had fewer primary dendrites, fewer total dendritic branches, and shorter total dendritic length than caudally projecting neurons. There were regional differences in percentage of neurons responding to electrical stimulation of left or right hypogastric, lumbar colonic, or left splanchnic nerves but not in nerve fibers connecting the S.m.g. and celiac ganglion. A greater percentage of caudally than rostrally projecting cephalad neurons responded to stimulation of any nerve trunk. These results indicate that the mouse S.m.g. contains at least two distinct types of neurons that differ in their morphology and their source of preganglionic synaptic input.
Prevention Strategies for Healthcare-Associated Pneumonia

Healthcare-associated pneumonia (HCAP) represents one of the largest subsets of patients with pneumonia. Based on epidemiological projections for the aging U.S. population, the number of hospitalizations for HCAP is expected to increase exponentially for the next several decades. The unique risk factors for colonization with resistant pathogens in these patients provide multiple opportunities for HCAP prevention. However, our current understanding of the most effective prevention measures is woefully inadequate and constitutes an extrapolation from studies done in community-acquired and hospital-acquired pneumonia patients. This review explores common prevention strategies that may be applicable to HCAP, highlights areas of controversy that require further study, and describes several areas of ongoing novel investigation.
EGFR mutations in malignant pleural effusions from lung cancer

A malignant pleural effusion (MPE) from lung cancer represents stage IV disease and portends a poor prognosis. Routine mutational analysis of tissue samples is the standard of care in advanced lung cancer management because it has treatment implications. Sampling of MPE is minimally invasive, safe, repeatable, and provides both diagnostic and therapeutic value. Mutational analysis on MPE has been shown to be feasible and correlates with a response to targeted therapy with tyrosine kinase inhibitors (TKIs). Guidelines recommend mutational testing in MPE, however there is no one standardized method for testing. There are several testing methods available for mutational analysis in pleural fluid including PCR, mutant-enriched PCR, DNA & RNA sequencing, and immunohistochemistry the sensitivity of which are dependent upon tumor cell heterogeneity. The advantages and disadvantages of each will be reviewed here.
Cortical myoclonus in huntington's disease associated with an enlarged somatosensory evoked potential

We report the electrophysiologic findings of myoclonus in a patient with Huntington's disease (HD). This patient was studied postoperatively after a bilateral fetal cell transplant in his striatum. Incomplete transient improvement was seen in the myoclonus, followed by gradual deterioration. The myoclonus itself had a cortical correlate and was associated with an enlarged somatosensory evoked potential (SEP), consistent with the presence of cortical reflex myoclonus. An enlarged SEP has not been previously reported in myoclonus associated with HD. The postulated mechanisms for myoclonus, when it occurs in HD, have differed in the literature. The reason for the transient improvement of the myoclonus following transplantation is unclear, but this case raises the possibility that basal ganglia circuits may modulate cortical myoclonic activity.
Low-temperature solvothermal synthesis of nanocrystalline indium nitride and Ga–In–N composites from the decomposition of metal azides

Nanocrystalline InN powders have been synthesized through metal azide decomposition in superheated toluene and refluxing hexadecane solvents near 280 °C. The metal azide intermediates were formed in situ through the metathesis reaction of InBr3 and NaN3. The InN products from toluene consist of ∼10 nm hexagonal (wurtzite) structured crystallites in aggregated arrangements. InN from hexadecane and lower temperature toluene reactions produced more poorly crystalline InN that appears to contain a cubic (zinc blende) component. Coordinating amine solvents led to decomposition of the nitride to indium metal. Several reactions were undertaken to produce mixed metal nitrides of the form Ga1−zInzN where z is 0.5 and 0.75. The mixed metal nitride products are analytically consistent with composite versus solid-solution formation, however some metal mixing is observed. Data from X-ray diffraction, electron microscopy, thermal analysis, elemental analysis, and several spectroscopic methods are combined to form a consistent picture of the bulk and surface structures for these nanocrystalline InN materials.
Link-sharing and resource management models for packet networks

Discusses the use of link-sharing mechanisms in packet networks and presents algorithms for hierarchical link-sharing. Hierarchical link-sharing allows multiple agencies, protocol families, or traffic types to share the bandwidth on a link in a controlled fashion. Link-sharing and real-time services both require resource management mechanisms at the gateway. Rather than requiring a gateway to implement separate mechanisms for link-sharing and real-time services, the approach in the paper is to view link-sharing and real-time service requirements as simultaneous, and in some respect complementary, constraints at a gateway that can be implemented with a unified set of mechanisms. While it is not possible to completely predict the requirements that might evolve in the Internet over the next decade, the authors argue that controlled link-sharing is an essential component that can provide gateways with the flexibility to accommodate emerging applications and network protocols. >
Coexisting Turbulent Climate Attractors in a Two-Layer Quasigeostrophic Model

Abstract An intriguing manifestation of the underlying nonlinear fluid dynamic character of the atmosphere is found in an idealized quasigeostrophic model of the troposphere. For identical forcing and dissipation, the model’s climate is found to depend sensitively upon the choice of initial conditions, tending either toward a state resembling the current Northern Hemisphere wintertime circulation, characterized by significant mobile synoptic-scale transient disturbance activity, or a circulation still possessing vigorous synoptic transient behavior but more characterized by lower-frequency transient activity. Both of these dynamical states are strongly turbulent, with well-developed inertial ranges in their energy cascades, and transient kinetic energy on the same order as the kinetic energy of the time mean flow. This suggests the existence of multiple underlying turbulent strange attractors for the system. The climates of these states differ substantially, with the turbulent attractor with reduced synop...
Superconducting Magnet Quench Protection for ISABELLE

A system is described which allows the main series current in the ring magnets to automatically bypass a quenching unit. The method employs the switching capabilities inherent in silicon diodes operating at very low temperatures. Experimentally determined parameters are given for a high current diode suitable for use in superconducting accelerators and storage rings.
Terminal Gas Velocity during Laparoscopy

Abstract Study Objective To assess the effect of port size in relation to laparoscopic gas flow and to determine the terminal velocity of gas flow during insufflation. Design Analysis and mathematical modeling of gas flow characteristics. Setting University biomedical engineering department. Interventions Analytic calculations including Bernoulli's equation to describe gas volumetric flow and velocity as it exits laparoscopic intraabdominal entrance sites. Measurements and Main Results Mathematical modeling showed that terminal velocity of gas entering the abdomen through needles or trocars reaches a practical limit depending on size and configuration of the gas exit site, amount of turbulence, length of delivery port, and gas flow. Flow rate was evaluated for circles of 2, 5, and 10 mm and annular slots of 0.1- to 0.01-mm thickness. Conclusion Resistance to gas flow increases and gas exiting terminal velocity increases as the effective area of the gas exit site decreases. Depending on the configuration of variable parameters, gas flow can reach 30 m/second.
On continuum limits of Markov chains and network modeling

In this paper we investigate the continuum limits of a class of Markov chains. The investigation of such limits is motivated by the desire to model very large networks. We show that under some conditions, a sequence of Markov chains converges in some sense to the solution of a partial differential equation. Based on such convergence we approximate Markov chains modeling networks involving a large number of components by partial differential equations. While traditional numerical simulation for very large networks is practically infeasible, partial differential equations can be solved with reasonable computational overhead using well-established mathematical tools.
Freshwater snails (Mollusca: Gastropoda) from the Commonwealth of Dominica with a discussion of their roles in the transmission of parasites

We collected six species of freshwater snails from Dominica, including Biomphalaria kuhniana (Clessin, 1883), Gundlachia radiata (Guilding, 1828), Helisoma (=Planorbella) trivolvis (Say, 1817), Melanoides tuberculata (Muller, 1774), Neritina punctulata Lamarck, 1816, and Physa marmorata Guilding, 1828. Our collections indicate that un-reported species such as G. radiata and H. trivolvis are established on Dominica, West Indies. We tested a limited number of M. tuberculata for rickettsial pathogens, Neorickettsia spp., but did not identify this agent. Three species of snails previously reported from Dominica, Biomphalaria glabrata (Say, 1818), Biomphalaria straminea (Dunker, 1848), and Thiara granifera (Lamarck, 1822), were not collected. Our data suggest that B. glabrata has not re-emerged as a prominent component of the freshwater snail fauna since it disappeared or was locally eradicated. In addition, previous reports of B. straminea were probably misidentifications of B. kuhniana, and some abnormally l...
Clusters as a source of error in molecular beam scattering experiments

Abstract Total scattering cross section for argon on argon obtained with a free jet molecular beam shows a source pressure dependence. From this dependence the concentration of dimer in the beam can be determined. The results are in good agreement with mass spectrometric measurements.
Objective Function Effect Based Pattern Search—An Implementation for 3D Component Layout

Generalized pattern search (GPS) algorithms have been used successfully to solve three-dimensional (3D) component layout problems. These algorithms use a set of patterns and successively decreasing step sizes of these patterns to explore the search space before converging to good local minima. A shortcoming of conventional GPS algorithms is the lack of recognition of the fact that patterns affect the objective function by different amounts and hence it might be efficient to introduce them into the search in a certain order rather than introduce all of them at the beginning of the search. To address this shortcoming, it has been shown by the authors in previous work that it is more efficient to schedule patterns in decreasing order of their effect on the objective function. The effect of the patterns on the objective function was estimated by the a priori expectation of the objective function change due to the patterns. However computing the a priori expectation is expensive, and to practically implement the scheduling of patterns, an inexpensive estimate of the effect on the objective function is necessary. This paper introduces a metric for geometric layout called the sensitivity metric that is computationally inexpensive, to estimate the effect of pattern moves on the objective function. A new pattern search algorithm that uses the sensitivity metric to schedule patterns is shown to perform as well as the pattern search algorithm that used the a priori expectation of the objective function change. Though the sensitivity metric applies to the class of geometric layout or placement problems, the foundation and approach is useful for developing metrics for other optimization problems.
Tuning thermal contact conductance at graphene-copper interface via surface nanoengineering.

Due to rapidly increasing power densities in nanoelectronics, efficient heat removal has become one of the most critical issues in thermal management and nanocircuit design. In this study, we report a surface nanoengineering design that can reduce the interfacial thermal resistance between graphene and copper substrate by 17%. Contrary to the conventional view that a rough surface tends to give higher thermal contact resistances, we find that by engraving the copper substrate with nanopillared patterns, an optimized hybrid structure can effectively facilitate the thermal transport across the graphene–copper interface. This counterintuitive behavior is due to the enhanced phonon interactions with the optimal nanopillared pattern. For pliable 2D materials like graphene, the structures can be easily bent to fit the surface formations of the substrate. The suspended areas of graphene are pulled towards the substrate via an attractive interatomic force, causing high local pressures (∼2.9 MPa) on the top region of nanopillars. The high local pressures can greatly enhance the thermal energy coupling between graphene and copper, thereby lowering the thermal contact resistances. Our study provides a practical way to manipulate the thermal contact resistance between graphene and copper for the improvement of nano-device performance through engineering optimal nanoscale contact.