cssi/SciSciGPT-SciSciNet huggingface dataset:
A Clock in the Sun

The sunspot cycle is quite variable in duration and amplitude, yet in the long term, it seems to return to solar minimum on schedule, as if guided by a clock with an average period of close to 11.05 years for the sunspot number cycle and 22.1 years for the magnetic cycle. This paper provides a brief review of the sunspot number cycle since 1750, discusses some of the processes controlling the solar dynamo, and provides clues that may add to our understanding of what controls the cadence of the solar clock.
Age-related loss of auditory sensitivity in the zebrafish (Danio rerio).

Abstract Age-related hearing loss (ARHL), also known as presbycusis, is a widespread and debilitating condition impacting many older adults. Conventionally, researchers utilize mammalian model systems or human cadaveric tissue to study ARHL pathology. Recently, the zebrafish has become an effective and tractable model system for a wide variety of genetic and environmental auditory insults, but little is known about the incidence or extent of ARHL in zebrafish and other non-mammalian models. Here, we evaluated whether zebrafish exhibit age-related loss in auditory sensitivity. The auditory sensitivity of adult wild-type zebrafish (AB/WIK strain) from three adult age subgroups (13-month, 20-month, and 37-month) was characterized using the auditory evoked potential (AEP) recording technique. AEPs were elicited using pure tone stimuli (115–4500 Hz) presented via an underwater loudspeaker and recorded using shielded subdermal metal electrodes. Based on measures of sound pressure and particle acceleration, the mean AEP thresholds of 37-month-old fish [mean sound pressure level (SPL) = 122.2 dB ± 2.2 dB SE re: 1 μPa; mean particle acceleration level (PAL) = -27.5 ± 2.3 dB SE re: 1 ms−2] were approximately 9 dB higher than that of 20-month-old fish [(mean SPL = 113.1 ± 2.7 dB SE re: 1 μPa; mean PAL = -37.2 ± 2.8 dB re: 1 ms−2; p = 0.007)] and 6 dB higher than that of 13-month-old fish [(mean SPL = 116.3 ± 2.5 dB SE re: 1 μPa; mean PAL = -34.1 ± 2.6 dB SE re: 1 ms−2; p = 0.052)]. Lowest AEP thresholds for all three age groups were generally between 800 Hz and 1850 Hz, with no evidence for frequency-specific age-related loss. Our results suggest that zebrafish undergo age-related loss in auditory sensitivity, but the form and magnitude of loss is markedly different than in mammals, including humans. Future work is needed to further describe the incidence and extent of ARHL across vertebrate groups and to determine which, if any, ARHL mechanisms may be conserved across vertebrates to support meaningful comparative/translational studies.
Microsurgical Dissection and Tissue Clearing for High Resolution Intact Whole Retina and Vitreous Imaging.

Neuronal and vascular structures of the retina in physiologic and pathologic conditions can be better visualized and characterized by using intact whole retina imaging techniques compared to conventional retinal flat mount preparations and sections. However, immunofluorescent imaging of intact whole retina is hindered by the opaque coatings of the eyeball, i.e., sclera, choroid, and retinal pigment epithelium (RPE) and the light scattering properties of retinal layers that prevent full thickness high resolution optical imaging. Chemical bleaching of the pigmented layers and tissue clearing protocols have been described to address these obstacles; however, currently described methods are not suitable for imaging endogenous fluorescent molecules such as green fluorescent protein (GFP) in intact whole retina. Other approaches bypassed this limitation by surgical removal of pigmented layers and the anterior segment of the eyeball allowing intact eye imaging, though the peripheral retina and hyaloid structures were disrupted. Presented here is an intact whole retina and vitreous immunofluorescent imaging protocol that combines surgical dissection of the sclera/choroid/retina pigment epithelium (RPE) layers with a modified tissue clearing method and light sheet fluorescent microscopy (LSFM). The new approach offers an unprecedented view of unperturbed vascular and neuronal elements of the retina as well as the vitreous and hyaloid vascular system in pathologic conditions.
Streptococcus mutans Lacking sufCDSUB Is Viable, but Displays Major Defects in Growth, Stress Tolerance Responses and Biofilm Formation.

Streptococcus mutans appears to possess a sole iron-sulfur (Fe-S) cluster biosynthesis system encoded by the sufCDSUB cluster. This study was designed to examine the role of sufCDSUB in S. mutans physiology. Allelic exchange mutants deficient of the whole sufCDSUB cluster and in individual genes were constructed. Compared to the wild-type, UA159, the sufCDSUB-deficient mutant, Δsuf::kan r , had a significantly reduced growth rate, especially in medium with the absence of isoleucine, leucine or glutamate/glutamine, amino acids that require Fe-S clusters for biosynthesis and when grown with medium adjusted to pH 6.0 and under oxidative and nitrosative stress conditions. Relative to UA159, Δsuf::kan r had major defects in stress tolerance responses with reduced survival rate of > 2-logs following incubation at low pH environment or after hydrogen peroxide challenge. When compared to UA159, Δsuf::kan r tended to form aggregates in broth medium and accumulated significantly less biofilm. As shown by luciferase reporter fusion assays, the expression of sufCDSUB was elevated by > 5.4-fold when the reporter strain was transferred from iron sufficient medium to iron-limiting medium. Oxidative stress induced by methyl viologen increased sufCDSUB expression by > 2-fold, and incubation in a low pH environment led to reduction of sufCDSUB expression by > 7-fold. These results suggest that lacking of SufCDSUB in S. mutans causes major defects in various cellular processes of the deficient mutant, including growth, stress tolerance responses and biofilm formation. In addition, the viability of the deficient mutant also suggests that SUF, the sole Fe-S cluster machinery identified is non-essential in S. mutans, which is not known in any other bacterium lacking the NIF and/or ISC system. However, how the bacterium compensates the Fe-S deficiency and if any novel Fe-S assembly systems exist in this bacterium await further investigation.
Mind, Brain, and Character: How Neuroscience Affects People's Views of Criminal Wrongdoers

Ordinary psychological explanations of criminal behavior tend to focus on the causal role of mental states such as intentions, beliefs, and desires. In contrast, neuroscientific explanations of criminal behavior focus attention on the causal role of physiological states within the brain. Although these explanations may be seen as compatible, highlighting the role of brain, as opposed to purely the mind, may deferentially affect the way lay individuals view criminal wrongdoers. The present research examines whether these different ways of explaining criminal wrongdoing affect people’s assessments of the relevant wrongdoers’ culpability and punishment, as well as their views of the wrongdoers’ overall character. In three studies, we found that people view wrongdoers more favorably, and think they should be punished less severely, when their behavior is caused by an emotional dysfunction that is described as neurological rather than mental/psychological. Studies 2 and 3 demonstrated that this effect arises because people view the wrongdoer’s actions as less diagnostic of his true character when his dysfunction is described as brain-based. Implications for using neuroscience to explain behavior in legal settings (and more generally) are discussed.
The Role of Tumor-Derived Exosomes (TEX) in Shaping Anti-Tumor Immune Competence

Emerging studies suggest that extracellular vesicles (EVs) mediating intercellular communication in the tumor microenvironment (TME) play a key role in driving cancer progression. Tumor-derived small EVs or exosomes (TEX) enriched in immunosuppressive proteins or in microRNAs targeting suppressive pathways in recipient cells contribute to reprogramming the TME into a cancer-promoting milieu. The adenosinergic pathway is an acknowledged major contributor to tumor-induced immune suppression. TEX carry the components of this pathway and utilize ATP to produce adenosine (ADO). TEX-associated ADO emerges as a key factor in the suppression of T cell responses to therapy. Here, the significance of the ADO pathway in TEX is discussed as a highly effective mechanism of cancer-driven immune cell suppression and of resistance to immune therapies.
The Fox and the Hedgehog: A Vision of Neuroscience Research in Psychiatry.

In his essay on the writings of Leo Tolstoy, philosopher Isaiah Berlin [1] proposed two types of historical thinkers: those seeking to explain the world through unified principles (hedgehogs) and those seeking to approximate it through various, sometimes disparate, paths of understanding (foxes). As a metaphor for two different approaches to prediction, Berlin’s idea raises an intriguing tension between explanation and approximation of natural phenomena. With a new decade of the brain dawning in psychiatry, a similar tension appears to underlie two different ways that neuroscientific thinking encroaches upon clinical understanding and practice: for simplicity, one can be termed a mechanismoriented approach and the other, an outcome-oriented approach. These approaches differ in terms ofmodeling principles, research methods, implications for drug discovery, and skill set needs (Table 1). The contrast between these two approaches raises interesting considerations for the field of psychiatry on scientific and clinical levels.
Myeloid cell leukemia-1 is an important apoptotic survival factor in triple-negative breast cancer

Breast cancer is the second-most frequently diagnosed malignancy in US women. The triple-negative breast cancer (TNBC) subtype, which lacks expression of the estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2, afflicts 15% of patients and is refractory to current targeted therapies. Like many cancers, TNBC cells often deregulate programmed cell death by upregulating anti-apoptotic proteins of the B-cell CLL/lymphoma 2 (Bcl-2) family. One family member, myeloid cell leukemia-1 (Mcl-1), is commonly amplified in TNBC and correlates with a poor clinical prognosis. Here we show the effect of silencing Mcl-1 and Bcl-2-like protein 1 isoform 1 (Bcl-xL) expression on viability in a panel of seventeen TNBC cell lines. Cell death was observed in a subset upon Mcl-1 knockdown. In contrast, Bcl-xL knockdown only modestly reduced viability, indicating that Mcl-1 is a more important survival factor. However, dual silencing of both Mcl-1 and Bcl-xL reduced viability in most cell lines tested. These proliferation results were recapitulated by BH3 profiling experiments. Treatment with a Bcl-xL and Bcl-2 peptide had only a moderate effect on any of the TNBC cell lines, however, co-dosing an Mcl-1-selective peptide with a peptide that inhibits Bcl-xL and Bcl-2 was effective in each line tested. Similarly, the selective Bcl-xL inhibitor WEHI-539 was only weakly cytotoxic across the panel, but sensitization by Mcl-1 knockdown markedly improved its EC50. ABT-199, which selectively inhibits Bcl-2, did not synergize with Mcl-1 knockdown, indicating the relatively low importance of Bcl-2 in these lines. Mcl-1 sensitivity is not predicted by mRNA or protein levels of a single Bcl-2 family member, except for only a weak correlation for Bak and Bax protein expression. However, a more comprehensive index composed of Mcl-1, Bcl-xL, Bim, Bak and Noxa protein or mRNA expression correlates well with Mcl-1 sensitivity in TNBC and can also predict Mcl-1 dependency in non-small cell lung cancer cell lines.
The Medical Model and the Preparation of Education Professionals.

By reviewing the training of medical professionals, one can identify simi-arities as well as interesting possibilities for the preparation of education professionals. On a very basic level, the fie...
IS-Related Operational Risk: An Exploratory Analysis

Past research concerning information systems (IS) risk has mainly focused on development risk. However, the impact of any risk event that occurs once the system is operational can be far more extensive. Such events are due to what has been termed operational risk. Our research is concerned with operational risk that involves an IS – or IS-related operational risk – which has received little attention in the academic literature. Specifically, we seek to offer a comprehensive exploratory analysis of IS-related operational risk based on a database documenting hundreds of actual IS-related operational risk events. Our findings could help managers and researchers to achieve a better understanding of the risk exposure associated with operational ISs in their current business environment and with new information technology (IT) investments under consideration. This research could also assist organizations in achieving a higher level of strategic and economic alignment, through the use of a systematic IS risk management approach.
Automated inspection of solder joints-a neural network approach

This paper describes a PC-based system for automated inspection of solder joints using neural networks. It presents extensive application of neural networks to solder joint quality data in the form of visual images. Numerous methods for data compression and feature extraction have been applied to enhance the performance of the neural networks. Up to 92 per cent accuracy in identifying solder joint defects was achieved using visual images. This discussion deals with visible light images only but all techniques may be extended equally to X-ray laminographic images as preliminary results from such applications indicate.
Ca, P, and pH relationships during spontaneous phosphaturia.

Data on phosphaturic urine are examined for statistical correlations among total and precipitated Ca and P, pH, Ca/P, and percentage of total Ca and P precipitated.
Factors governing the structural phase transition temperatures of doped La2CuO4 systems

Abstract We examined the doping dependence of Ishibashi's free energy function for La2−xBaxCuO4, which describes the successive HTT → LTO → LTT phase transitions of this doped La2CuO4 system, in terms of the tolerance factor and the local steric pressure effect of the dopant. On the basis of these microscopic considerations, we explained the general trends in the doping dependence of the HTT → LTO and the LTO → LTT transition temperatures in other doped La2CuO4 systems.
The Distribution of Tax Burdens in the American States: the Determinants of Fiscal Incidence

G IVEN the coercive nature of taxes and their high salience to voters in state and local elections (Hansen 1983: 178), it is hardly surprising that governments take great pains to justify taxes as fair and equitable. Still, most analyses of state and state-local tax systems start with the assumption that they are generally regressive in their overall incidence pattern (Pechman and Okner 1974; Pechman 1985). But some are more regressive than others. What accounts for this variation?
Abstract P4-10-10: The Gammapod TM: A Novel Breast Specific Stereotactic Body Radiation Therapy (SBRT) for Small Breast Cancers

Introduction: SBRT is a novel approach to precisely deliver high doses of radiation therapy to a define target, while normal tissues immediately surrounding the tumor receives a significantly lower (i.e. tolerable) dose. This technique has revolutionized the management of small medically inoperable lung cancer with local control rates recently reported in the co-operative setting of 98% now setting the stage for challenging surgery as the standard of care for select patients with lung cancer. SBRT has not been used in the breast, since the breast is a pliable organ without a suitable immobilization device and the lack of an SBRT system that can create the rapid fall off in dose necessary to deliver ablative doses of radiation safely in the breast. The purpose of this NIH funded project is to develop a dedicated SBRT system for early breast cancer which could eventually lead paradigm shift in the management of breast cancer similar to lung cancer. Materials and Methods: The SBRT system was developed such that dose distributions produced would be similar to stereotactic radiosurgery in the brain where the the drop off of the prescription isodose to 50% of the prescription dose was less than 5 mm. The device uses 36 non-coplanar Co-60 sources which rotate around a focal point to produce 36 non-coplanar arcs. The system incorporates the use of a floating/dynamic table which together with the rotatable sources enables differential dosing of target volumes similar to intensity modulated RT allowing higher ablative doses to the gross tumor and a lower sub clinical dose to treat microscopic tumor foci. In addition the SBRT system, a breast specific immobilization device was developed. This system consists of 2 layers with an air tight seal in between. Once placed on the breast a small negative pressure secures it to the breast. A prospective trial tested the reproducibility of the breast cup using the centroid of the post-operative clips on 2 consecutive CT simulations separated by 10 to 60 minutes simulating the treatment planning scenerio in the prone position. During this time, patients were also asked to fill out a questionaire regarding the comfort of this approach. Results: The issues within the specific aims of the grant have been effectively solved and have led to a breast specific immobilization device and a breast specific SBRT system — The Gammapod TM. The immobilization device demonstrated a set up error of less than 3 mm a significant decrease from the 10 mm planning target volume expansion as recommended in NSABP B39 for patients undergoing 3 dimensional conformal partial breast radiotherapy. All patients described this experience as more comfortable in comparison to a biopsy and similar to the experience of a mammogram.Dosimetric studies using Monte Carlo simulation demonstrate that tumors up to 5 cm in diameter, and 5 mm from the chest wall, lung/heart receive Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-10-10.
VTVH-MCD and DFT Studies of Thiolate Bonding to {FeNO}7/{FeO2}8 Complexes of Isopenicillin N Synthase: Substrate Determination of Oxidase versus Oxygenase Activity in Nonheme Fe Enzymes

Isopenicillin N synthase (IPNS) is a unique mononuclear nonheme Fe enzyme that catalyzes the four-electron oxidative double ring closure of its substrate ACV. A combination of spectroscopic techniq...
Reactivity of the cysteine residues in the protein splicing active center of the Mycobacterium tuberculosis RecA intein.

Protein splicing involves the self-catalyzed excision of an intervening polypeptide segment, an intein, from a precursor protein. The first two steps in the protein splicing process lead to the formation of ester intermediates through nucleophilic attacks by the side chains of cysteine, serine, or threonine residues adjacent to the splice junctions. Since both nucleophilic residues in the Mycobacterium tuberculosis RecA intein are cysteine, their reactivities could be compared by sulfhydryl group titration. This was accomplished by using fusion proteins containing a truncated RecA intein modified by mutation to prevent protein splicing, in which the cysteines at the splice junctions were the only sulfhydryl groups. The ability to undergo hydroxylamine-induced cleavage at the upstream splice junction showed that the modified intein was not impaired in the ability to form ester intermediates. Sulfhydryl titration with iodoacetamide, monitored by quantitating the residual thiols after reaction with a maleimide derivative of biotin, revealed a striking difference in the apparent pK(a) values of the cysteines at the two splice junctions. The apparent pK(a) of the cysteine at the upstream splice junction, which initiates the N-S acyl rearrangement leading to the linear ester intermediate, was approximately 8.2, whereas that of the cysteine residue at the downstream splice junction, which initiates the transesterification reaction converting the linear ester to the branched ester intermediate, was about 5.8. This suggests that the transesterification step is facilitated by an unusually low pK(a) of the attacking thiol group. Comparison of the rates of cleavage of the linear ester intermediates derived from the M. tuberculosis RecA and the Saccharomyces cerevisiae VMA inteins by dithiothreitol and hydroxylamine revealed that the former reacted relatively more slowly with dithiothreitol, suggesting that the RecA intein has diverged in the course of evolution to react preferentially with thiolate anions and thus lacks the basic groups that may facilitate nucleophilic attack by thiols in other inteins.
Diatom Evidence on Wisconsin and Holocene Events in the Bering Sea

Previous work on surface (modern) sediments has defined diatom species which appear to be good indicators of various oceanographic/ecologic conditions in the North Pacific Ocean and marginal seas. Three long cores from the eastern and northern sides of the Aleutian Basin show changes in species assemblage which can be interpreted in terms of changes in the ocean environment during the last glaciation (Wisconsin) and the Holocene. The early and late Wisconsin maxima were times of prolonged annual sea-ice cover and a short cool period of phytoplankton productivity during the ice-free season. The middle Wisconsin interstade, at least in the southern Bering Sea, had greater seasonal contrast than today, with some winter sea-ice cover, an intensified temperature minimum, and high spring productivity. Variations in clastic and reworked fossil material imply varying degrees of transport to the basin by Alaskan rivers. The results of Jouse from the central Bering Sea generally correspond with those presented here, although there are problems with direct comparison.
Undecaprenyl Diphosphate Synthase Inhibitors: Antibacterial Drug Leads

There is a significant need for new antibiotics due to the rise in drug resistance. Drugs such as methicillin and vancomycin target bacterial cell wall biosynthesis, but methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) have now arisen and are of major concern. Inhibitors acting on new targets in cell wall biosynthesis are thus of particular interest since they might also restore sensitivity to existing drugs, and the cis-prenyl transferase undecaprenyl diphosphate synthase (UPPS), essential for lipid I, lipid II, and thus, peptidoglycan biosynthesis, is one such target. We used 12 UPPS crystal structures to validate virtual screening models and then assayed 100 virtual hits (from 450,000 compounds) against UPPS from S. aureus and Escherichia coli. The most promising inhibitors (IC50 ∼2 μM, Ki ∼300 nM) had activity against MRSA, Listeria monocytogenes, Bacillus anthracis, and a vancomycin-resistant Enterococcus sp. with MIC or IC50 values in the 0.25-4 μg/mL range. Moreover, one compound (1), a rhodanine with close structural similarity to the commercial diabetes drug epalrestat, exhibited good activity as well as a fractional inhibitory concentration index (FICI) of 0.1 with methicillin against the community-acquired MRSA USA300 strain, indicating strong synergism.
Band 3 catalyzes sickle hemoglobin polymerization.

We have measured homogeneous and heterogeneous nucleation rates of sickle hemoglobin (HbS) in the presence of a strongly binding deletion mutant of the cytoplasmic domain of band 3 (cdb3), a membrane protein known to form dimers and to bind 2 HbS molecules to such a dimer, and we find that it accelerated both rates by a factor of 2. A weakly binding mutant, in contrast showed no impact on nucleation rates, contrary to naive expectations of a slight enhancement based on the molecular crowding of the solution by the mutant. We find we can explain these phenomena by a model of HbS-cdb3 interaction in which the strong binding mutant, by stabilizing an HbS dimer, catalyzes the nucleation process, while the weak mutant binds only 1 HbS molecule, effectively inactivating it and thereby compensating for the crowding of the solution by the cdb3. The catalytic behavior we observe could play a role in intracellular processes.
Cooperative Cataloging in a Post-OPAC World

The identity of individual libraries has traditionally been based on locally defined, but highly duplicative, collections. The need to build equally duplicative catalogs has provided incentive for cooperative cataloging. In the future, the collections of libraries will be not so much duplicated as shared, and separate libraries may not have separate public catalogs. Is there a place for cooperative cataloging in such a future? Yes, but future cooperative cataloging efforts will need to focus on important post–online public access catalog (OPAC) world challenges, including the development of “virtual” worldwide library collections and the provision of metadata support for new information resources and systems.
An interactive design, visualization, and analysis tool for information flow over a tactical data network

The United States Army is embracing the use of new information technologies to achieve tactical advantage over potential adversaries, Existing and future information systems place a significant load on the tactical data network, resulting in a bandwidth management crisis, yet there is no prioritization, allocation, planning, or management tool available to simulate information flows over time for different communications configurations under different operational conditions. The development of such a tool requires the implementation of a communication network model and the supporting discrete-event simulation system. Models for the information systems that induce flows, the command posts using the information systems, and the influence of operational conditions on the information flows are also required, as is a graphical user interface that allows the tactical planner to configure the system and set up data capture. The visual development techniques used in this tool make it easy for the planner to design and build communication networks to support operations, then interactively reconfigure the network, run what-if scenarios, and visualize the effects. The system can be used for training, design of experimental networks, and to support rapid decision-making.
Syndication of the earth system: the future of geoscience?

Abstract Current global change policy debate reverberates around the polarized extremes of civilization-level cooperation through treaties as a mitigation tactic, on the one hand, and a wait-and-see approach that may lead to a climatic tragedy of the commons, on the other. Meanwhile, energy technology research is rapidly generating a perception that it will be possible to tune the earth system via carbon sequestration and other types of biogeochemical engineering. The consequences of this potential for planetary management, based on provincial self-interest, include the transition of the earth sciences into a security industry involving proprietary scientific knowledge bases of biogeochemical cycling and the evolution of a climate-design brokerage dominated by military/industrial interests. As the dominant political powers perceive the potential for planetary engineering and consider implementation, the global economy will adjust to exploit new opportunities, perceptions of which will be determined by the quality of system simulations. The growth of a viable international climate-design community will profoundly influence the trajectory of the earth system by providing either the illusion or the reality of predictability. Although this process will be chaotic at first, the probability of stabilization will ultimately be enhanced because the vast resources of the military/industrial sector will become involved. These concepts are disturbingly familiar in that they acknowledge the pervasion of competition and conflict in human technological affairs. However, they are consistent with approaches used in thermodynamics, ecological energetics, behavioral evolution, economics, and interdisciplinary climate science to describe collectively the evolution of the earth system. This paper argues that the perception that the climate can be regulated inexpensively will create an economic driving force for international cartel-style management of the total earth system. That is, the earth system may well become syndicated by those with the resources to effect large-scale management.
Studies of the hypoglycemic effect of D-amphetamine in aggregated mice.

Abstract The hypoglycemia that occurs in aggregated mice after the injection of d -amphetamine sulfate (10 mg/kg) has been investigated. Insulin deficiency as a result of injection with serum containing antibodies to insulin, and which produced hyperglycemia in control mice, was not sufficient to prevent the development of hypoglycemia in aggregated mice given amphetamine. Liver glycogen levels were lower, but liver lipid content was unaltered in the hypoglycemie mice. Pancreas insulin levels were not significantly different from control levels in the aggregated mice which became hypoglycemie after amphetamine injection, but the incorporation of l -Zalanine- 14 C into glucose by liver slices removed from these animals was increased. The amount of 14 CO 2 expired from mice injected intravenously with a tracer amount of glucose-U- 14 C was decreased if the mice were made insulin deficient with anti-insulin serum, but the oxidation of labeled glucose increased if the mice were also injected with amphetamine and isolated. Aggregated mice, injected with anti-insulin serum and amphetamine, oxidized three times the amount of labeled glucose as the control mice given anti-insulin serum alone. The hypoglycemia that develops in aggregated mice injected with amphetamine is not due to excessive insulin secretion or decreased gluconeogenesis, but is probably the result of the markedly increased glucose utilization during severe motor activity.
Gravity-Induced Density Discontinuity Waves in Sand Columns

Formulas are obtained for the speeds of propagation of gravity-induced rarefaction and condensation density discontinuities in vertical sand columns. A rarefaction wave is induced in a column of sand at rest by removing the support at the bottom of the column. A condensation shock is induced by reintroducing the support, which stops the sand from falling. The theoretical prediction of the speed of propagation of the leading edges of the rarefaction wave corresponds well with the speed measurements obtained in a preliminary experiment.
Progressive failure analyses of compression-loaded composite curved panels with and without cutouts

Progressive failure analyses results are presented for composite curved panels with and without a circular cutout and subjected to axial compression loading well into their postbuckling regime. Ply damage modes such as matrix cracking, fiber-matrix shear, and fiber failure are modeled by degrading the material properties. Results from finite element analyses are compared with experimental data. Good agreement between experimental data and numerical results are observed for most part of the loading range for the structural configurations considered. Modeling of initial geometric imperfections may be required to obtain accurate analysis results depending on the ratio of the cutout width to panel width.
Sequence dependence and direct measurement of crossover isomer distribution in model Holliday junctions using NMR spectroscopy.

A 32-base-pair model of the Holliday junction (HJ) intermediate in genetic recombination has been prepared and analyzed in-depth by 2D and 3D 1H NMR spectroscopy. This HJ (J2P1) corresponds to a cyclic permutation of the base pairs at the junction relative to a previously studied HJ [J2; Chen, S.-M., & Chazin, W. J. (1994) Biochemistry 33, 11453−11459], designed to probe the effect of the sequence at the n − 1 position (where n is the residue directly at the branch point) on the stacking geometry. Observation of several interbase nuclear Overhauser effects (NOEs) clearly indicates a strong preference for the isomer opposite that observed for J2, confirming the dependence of stacking isomer preference on the sequence at the junction. As for other model HJs studied, a small equilibrium distribution of the alternate isomer could be identified. A sample of J2P1 was prepared with a single 15N-labeled thymine residue at the branch point. 1D 15N-filtered 1H-detected experiments on this sample at low temperature ...
Relation between DH ratios and 18O16O ratios in cellulose from linen and maize—Implications for paleoclimatology and for sindonology

Abstract The 18 O 16 O ratios of cellulose and the D H ratios of cellulose nitrate were determined for linen, a textile produced from the fibers of the flax plant Linum usitatissimum, and for maize (Zea mays) from a variety of geographic locations in Europe, the Middle East, and North and South America. The regression lines of δD values on δ18O values had slopes of 5.4 and 5.8 for the two species. Statistical analysis of results reported in the only other study in which samples of a single species (the silver fir Abies pindrow) that grew under a variety of climatic conditions were analyzed yielded slopes of ~6 when δD values of cellulose nitrate were regressed on δ18O values of cellulose. The occurrence of this previously unrecognized relationship in three species suggests it may obtain in other plants as well. Determining the basis for this relationship, which is not possible given current understanding of fractionation of the isotopes of oxygen and hydrogen by plants, should lead to increased understanding of how D H and 18 O 16 O ratios in cellulose isolated from fossil plants are related to paleoclimates. The separation of most linen samples from Europe from those originating in the Middle East when δD values are plotted against δ18O values suggests it may be possible to use the isotope ratios of cellulose prepared from the Shroud of Turin to resolve the controversy concerning its geographic origin.
Infrared Spectra of α-Alanine Adsorbed on Cu-Montmorillonite

Infrared spectroscopy has presented an effective tool for determining the structures of compounds adsorbed on clays. Cloos et al. have investigated the infrared spectra of amino acids such as glycine, glycylglycine, and β-alanine adsorbed on sodium-, calcium-, and hydrogen-montmorillonite, and determined that the protonated cation was the dominant adsorbed species. In this investigation, we have analyzed the infrared spectra of α-alanine adsorbed on copper-montmorillonite prepared at several different pH's to determine the types of complexes that are formed in the interlamellar spaces. Cu2+ ions readily form complexes with α-alanine in aqueous solution and, therefore, similar adsorbed species should be observed on montmorillonite. The infrared spectra of related complexes in crystals and solutions have been used to identify the adsorbed species, and to make empirical band assignments.
A fast texture feature extraction method for region-based image segmentation

In region-based image segmentation, an image is partitioned into connected regions by grouping neighboring pixels of similar features. To achieve fine-grain segmentation at the pixel level, we must be able to define features on a per-pixel basis. Typically for individual pixels, texture feature extraction is very computationally intensive. In this paper, we propose a new hierarchical method to reduce the computational complexity and expedite texture feature extraction, by taking advantage of the similarities between the neighboring pixels. In our method, an image is divided into blocks of pixels of different granularities at the various levels of the hierarchy. A representative pixel is used to describe the texture within a block. Each pixel within a block gets its texture feature values either by copying the corresponding representative pixel’s texture features, if its features are deemed sufficiently similar, or by computing its own texture features if it is a representative pixel itself. This way, we extract texture features for each pixel in the image with the minimal amount of texture feature extraction computation. The experiments demonstrate the good performance of our method, which can reduce 30% to 60% of the computational time while keeping the distortions in the range of 0.6% to 3.7%. By tailoring the texture feature extraction threshold, we can balance the tradeoff between extraction speed and distortion according to the each system’s specific needs.
Welcome to Me-Mart: The Politics of User-Generated Content in Personal Blogs

This article uses a discursive analysis of personal blogging handbooks and personal blogs to reflect on the politics of user-generated content (UGC) as it is created, circulated, valuated, quantifi...
Strength of fibers from wholly aromatic polyesters

A theory of the strength (or the tenacity) of highly oriented Liquid Crystal Polymer (LCP) fibers was developed, and its results were compared with existing tensile strength data of fibers of a copolymer of 1,4-oxybenzoate and 6,2-oxynaphthoate. A basic premise of the theory is that the mechanical load transfer between polymer chains is through intermolecular interaction which acts in a manner similar to that of shear stress, and that the fiber strength is primarily governed by the intermolecular adhesion strength. The theory also incorporates the effects of MW, MW distribution, and the chain orientation distribution. Analysis of the experimental tenacity data demonstrates that the present theory can quantitatively describe the variation of the tenacity of LCP fibers with MW both in the as-spun and in the heat-treated states. The theory further predicts that the predominant factor governing the tenacity of LCP fibers is primarily due to MW increase due to solid-state polymerization. It is also demonstrated that the intermolecular adhesion between LCP chains is relatively weak and does not improve with heat treatment. The absence of factors that limit the MW increase (i.e, imbalanced end-groups and side reactions of end groups) is a prerequisite for fast heat treatment of a LCP fiber to a high tenacity.
Conformational studies of trihalomethyl formates by ab initio molecular orbital calculations

Abstract Ab initio calculations for trifluoromethyl formate ( 1 ) and trichloromethyl formate ( 2 ) were performed using Hartree–Fock, DFT, and electron correlation methods. At the MP2/6-311G(df,pd) level, the E -isomer of 1 was calculated to have a free energy of 1.140 kcal/mol, relative to the Z . The dipole moments of the Z and E conformations were 2.46 and 2.17 D, respectively. Although the difference in dipole moments was calculated to be close to zero, with a slightly more favorable (lower) value for the E -isomer, the Z isomer is predicted to predominate. Free-energy barriers of 7.11 and 5.97 kcal/mol for interconversion of conformations were calculated at the same level. A detailed study of rotation about the bond between the CF 3 carbon and the ‘ether’ oxygen indicated that the preferred orientation of the CF 3 group in both the E and Z conformations possessed a COCF dihedral angle of 180°, and electronic energies were calculated for 13 or 7 points at 10° intervals from these conformations. The rotational barriers were found to be 2.50 ( E ) and 4.51 ( Z ) kcal/mol. The MP2/6-311G(df,pd) level calculations for 2 predicted that the Z conformation is more stable than the E isomer by 0.857 kcal/mol, and the calculated dipole moments were 2.02 ( Z ) and 2.51 D ( E ). The rotational barriers for the CCl 3 group were 4.18 and 6.51 kcal/mol for the E and Z conformations, respectively. Free-energy barriers of 7.08 and 6.22 kcal/mol for interconversion of conformations were calculated.
Product-process development integration in manufacturing

Organizations vary greatly in their approaches and success in the introduction of new products and services. In this study, it was proposed that much of this variance can be captured by understanding the extend to which product design and process design are integrated in new program launches. A mailed survey of 43 domestic firms was used to test four propositions concerning product-process development practices. Significantly, it was found that firms using the more rare design-manufacturing personnel integrating mechanisms engineering job rotation and mobility have higher sales per employee. Results of a discriminant analysis show that firms benchmarking on product development practices, as contrasted with performance benchmarks, were significantly more likely to use both the rare and the more common forms of design-manufacturing integration i.e., train personnel in new design, methods, have manufacturing sign-off on design reviews, and restructure, e.g., use teams. Significantly, these firms also report a greater proportion of degreed manufacturing engineers. Not surprisingly, larger firms and business units were found to take longer to develop new products.
Study of the Heart Beat of Chick Embryo

Abstract The heart is an organ whose function governs life in living beings. The manifestation of the main work of the heart is the rate of heart beat. This function of the heart may markedly affect the development of the organism particularly in the embryonic stage, or cause some disturbance in the function of other organs constituting it later. The necessity, seriousness and importance of the problem in the field of incubation speaks for itself. This study is concerned with the attempt to secure more information of the heart action of the chick, while still in the embryonic phase of life. Interest and hope were also cherished that we may obtain some relation between age, growth and pulse rate. The review of the literature indicates that the problem has its past. Wernicke (1876), Preyer (1885), Fano and Bodano (1889), and Cesano (1911–12) were the earliest workers. They disagreed greatly in . . .
Simple, low-cost stereographics: VR for everyone

Students are very interested in cutting-edge technologies like virtual reality (VR), and VR has many potential uses in education. However, building VR applications has proved challenging due to both cost and technical skill barriers. Through a series of experiments in "shoestring" VR, we have developed methods of bringing an important facet of VR, stereoscopic display, to our students in a simple, cost-effective way. This paper describes our approach.
Enhancement of t-[35S]Butylbicyclophosphorothionate and [3H]Strychnine Binding by Monovalent Anions Reveals Similarities Between γ-Aminobutyric Acid- and Glycine-Gated Chloride Channels

The characteristics of [3H]strychnine and t-[35S]-butylbicyclophosphorothionate ([35S]TBPS) binding to sites associated with glycine- and gamma-aminobutyric acid (GABA)-gated chloride channels were compared in the presence of a series of anions with known permeabilities through these channels. Good correlations were found between (a) the potencies (EC50) of these anions to stimulate radioligand binding and their permeabilities relative to chloride; (b) the affinities (KD) of these radioligands in the presence of fixed concentrations of these anions and their relative permeabilities; (c) the potencies (EC50) of these anions to stimulate [35S]TBPS and [3H]strychnine binding; and (d) the affinities (KD) of [3H]strychnine and [35S]TBPS measured at a fixed concentration of these anions. These studies support electrophysiological and biochemical observations demonstrating similarities between glycine- and GABA-gated chloride channels, and suggest that anions enhance [3H]strychnine and [35S]TBPS binding through specific anion binding sites located at the channels.
The effects of dynamic ionospheric outflow on the ring current

[1] The importance of ionospheric O+ on the development of the storm time ring current is recognized but not well understood. The addition of this outflow in global MHD models has the potential to change the magnetic field configuration, particle densities and temperatures, and the convection electric field. This makes including heavy ion outflow in ring current simulations difficult, as this addition cannot be easily decoupled from a host of other changes. This study attempts to overcome this problem by using three coupled models, PWOM, RIM, and BATS-R-US, to drive a ring current model, RAM-SCB. The differences in drivers when outflow is included and is not included are compared to see how outflow changes ring current input. It is found that including this outflow reduces the convection electric field, lowers the plasma sheet number density and temperature, and increases the complexity of the plasma sheet ion composition both temporally and spatially. These changes cause an overall reduction in ring current energy density. Further simulations that attempt to isolate these effects find that the most important change in terms of ring current development is the drop in convection electric field. Local time dependencies of O+ injections are found to be nontrivial as well. Capturing all of these effects requires a whole system, first-principles approach.
Attempts to measure thermally stimulated currents in chalcogenide glasses

The thermally stimulated currents (TSC) in a number of amorphous chalcogenide glasses are studied. In order to detect small changes in conductivity, after exposure to light, two samples are used in a bridge configuration. The TSC observed are found to be independent of the heating rate and the decay times are of several hours at 300 K. We find that our observations cannot be explained in terms of thermally stimulated currents. Models are discussed to explain the phenomena observed. We suggest that the observed changes in conductivity are caused by the same photoinduced defects which give rise to the reversible light-induced shifts of the optical-absorption edge in a number of chalcogenide glasses.
Analysis of the Pockels effect in ferroelectric barium titanate thin films on Si(001)

Display Omitted Highly crystalline BaTiO3 was integrated on Si using molecular beam epitaxy.Electro-optic response was evaluated for a-axis, c-axis, and mixed films.Increased a-axis fraction correlated with increased electro-optic response.Post-deposition oxygen anneal improved crystallinity and reduced leakage current. High-quality epitaxial BaTiO3 (BTO) on Si has emerged as a highly promising material for future electro-optic (EO) devices based on BTO's large effective Pockels coefficient. We report on the EO response of BTO films deposited on Si by molecular beam epitaxy (MBE), and characterize the structure of these films by reflection high-energy electron diffraction and X-ray diffraction. O2 rapid thermal anneal at 600?C for 30min ensures full oxidation of BTO for minimal leakage current with minimal change in crystalline structure.
Density Gradient Separation of Marrow Precursor Cells Restricted for Antibody Specificity

Potentially immunocompetent cells of (C57BL/6 x DBA/2) F(1) mouse bone marrow are committed to antigenic determinants of sheep or burro erythrocytes prior to interaction with thymus-derived cells and participation in immune responses to administered antigens. At this stage of differentiation marrow cells of this particular mouse strain are not yet restricted for the immunoglobulin M or immunoglobulin G antibody class. By equilibrium centrifugation in discontinuous gradients of bovine serum albumin, precursors of cells that produce antibody to sheep erythrocytes migrate to denser regions, whereas the precursors of immunocytes that produce antibody to burro erythrocytes remain in the lower density regions. cursors for all specificities.