cssi/SciSciGPT-SciSciNet huggingface dataset:
Studies of Histone Methylation during the HeLa S-3 Cell Cycle

Abstract The rate and specificity of histone methylation were examined throughout the HeLa S-3 cell cycle in cultures synchronized by selective detachment in mitosis or by double thymidine block. (a) Of all the cellular fractions tested, only the 0.25 n H2SO4-soluble nuclear fraction contained proteins which appeared to be methylated at high rates. Within this fraction histone polypeptides f2a1 and f3 were methylated at the highest rates, f2b and f2a2 were methylated at lower rates and f1 polypeptides were not methylated at all. (b) Lysine residues in histone fractions f2a, f2b, and f3 were methylated throughout the cell cycle with maximum rates of methylation occurring in G2 phase and mitosis. Only histone f3 polypeptides contained significant amounts of methylated arginine and histidine residues. These residues were methylated at maximum rates during the S phase of the cell cycle. (c) Mitotic cells contained a higher percentage of methylated histone molecules than cells at other stages of the cell cycle and it was calculated that if there was only one methylation site in each of the molecules, from 80 to 100% of all f2a1, f2b, and f3 polypeptides were methylated. (d) The ratios of e, e-N-dimethyllysine to e-N-monomethyllysine in the histone fractions of the heteroploid malignant HeLa S-3 cell were about half the ratios of these amino acids reported found in the corresponding histones of normal cells. (e) The turnover rate of histone methyl groups was about 1 to 2% per hour depending upon the fraction.
The action of bromine on Δ7-ergostene and choletene derivatives

Abstract The major product, obtained in yields up to 50% from the action of bromine on 5-dihydroergosteryl acetate (ergosta-7,22-dien-38-yl acetate) is 7,11,22a,23a-tetrabromoergost-8-en-38-yl acetate. It is accompanied by an isomer, 7,8,22a,23a-tetrabromoergost-14-enyl and other Δ 7,22 -ergostadienyl esters in described. Nuclear magnetic resonance chemical shifts of the angular methyl group protons are reported for represented classes and compared with calculated values.
Reversal of multi drug resistance to taxanes by P-glycoprotein modulating chemopreventive phytochemicals

AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA 2278 Breast cancer is a leading cause of cancer-related death among American women. The etiology of majority of breast cancers is multifactorial, of which 95% is environmental and hormonal. Polycyclic aromatic hydrocarbons (PAHs), commonly found in our environment are carcinogenic by genotoxic mechanisms. Some of the environmental chemicals mimic the properties of estrogen and may exert a hormonal influence on breast cancer. These chemicals share a common mode of action by activating the estrogen receptor (ER) and thereby elicit estrogenic responses. In addition to being estrogenic, xenoestrogens interact with xenobiotic- and drug-metabolizing CYP forms, including members of the CYP1A and CYP3A subfamilies. The regulation of gene expression of various drug metabolizing enzymes (DMEs) has potential impact on drug interactions of many therapeutic agents. DMEs include phase I, phase II metabolizing enzymes as well as phase III transporters. P-glycoprotein (P-gp), Pregnane X receptor (PXR), and CYP3A4 are associated with multi drug resistance (MDR) in breast cancer chemotherapy. Taxanes are among the most unique, and successful chemotherapeutic agents used for the treatment of breast and ovarian cancer. Taxanes induce CYP3A by activating PXR-mediated transcription and enhance P-gp mediated drug clearance in human mammary tumor cells. The abundant and inexpensive chemopreventive dietary phytochemicals are being explored as P-gp modulators for the reversal of MDR to breast cancer chemotherapeutic drugs. In the present study, we evaluated the effects of PAHs and chemopreventive dietary phytochemicals on the expression of liver and mammary CYP3A11, PXR, and P-gp activities. In wild type (C57BL/6J) female mice treated with 7,12-dimethylbenz(a)anthracene (DMBA), the apoprotein contents (Western blotting), and mRNA (Real time RT-PCR) expression of CYP3A11 and PXR genes were elevated in liver tissues of mice exposed to taxanes. The CYP3A11 and PXR gene expression was down regulated when the mice were treated with both taxanes and phytochemicals. The mammary P-gp expression was elevated in mice treated with taxanes compared to controls. Administration of phytochemicals along with taxanes inhibited the P-gp expression significantly showing a potential to reverse multi drug resistance. Induction of specific DNA adducts was observed in liver and mammary tissues of mice treated with PAHs and phytochemicals. These studies show a potential for development of dietary phytochemical as a therapeutic drug to be used in combination chemotherapy for treating human breast cancer.
Discontinuous, conserved neutralization epitopes overlapping the CD4-binding region of human immunodeficiency virus type 1 gp120 envelope glycoprotein.

Abstract Monoclonal antibodies have been isolated from human immunodeficiency virus type 1 (HIV-1)-infected patients that recognize discontinuous epitopes on the gp120 envelope glycoprotein, that block gp120 interaction with the CD4 receptor, and that neutralize a variety of HIV-1 isolates. Using a panel of HIV-1 gp120 mutants, we identified amino acids important for precipitation of the gp120 glycoprotein by three different monoclonal antibodies with these properties. These amino acids are located within seven discontinuous, conserved regions of the gp120 glycoprotein, four of which overlap those regions previously shown to be important for CD4 recognition. The pattern of sensitivity to amino acid change in these seven regions differed for each antibody and also differed from that of the CD4 glycoprotein. These results indicate that the CD4 receptor and this group of broadly neutralizing antibodies recognize distinct but overlapping gp120 determinants.
The submillimetre extragalactic background light and the star-formation history of the Universe

The submillimetre extragalactic background light is comparable with or exceeds that of the optical and ultraviolet (UV) wavelength ranges, showing directly that much of the energy radiated by star ...
Aging Families: The Personal, Permanent Group

Later life families present a very special instance of group psychotherapy with older adults. This paper describes the challenges faced by later life families, including major life events to which multiple family members must adapt, and the increasing dependency of some elderly members. A developmental framework for later life problems is offered as a therapy frame useful to families. Key aspects of therapy process with later life families are also presented. Goals, strategies, structures of therapy, and the therapist’s role are all shaped by the long and intimate history of the members of this special form of group.
Congenital diaphragmatic hernia: where are we and where do we go from here?

The infant born with congenital diphragmatic hernia (CDH) remains one of the most complex patients to manage. Pulmonary hypoplasia and immaturity of the CDH lung are well recognized as the definitve limitation leading to the high mortality rates. Based on the knowledge that CDH is more a physiological disease than a surgical disease, we have shifted our management strategy from immediate repair to delayed repair and stabilization. The associated pulmonary hypertension and right-to-left shunt are common and rarely the cause of death and as such may be largely ignored. Extracorporeal membrane oxygen has been shown to salvage some of the most severely affected neonates. Other advanced and experimental respiratory therapies merit investigation in properly conducted prospective randomized multi-center trials. Survivors of CDH have predictable pulmonary, gastrointestinal and nutritional problems which, when identified and treated early, are correctable. CDH survival is close to 90% at most advanced centers. Uniform standards for CDH mannagement do not exist however. Therefore a minimal set of practice standards should be developed from evidenced-based scientific review.
Lithium and Sodium Ion Binding Energies of N-Acetyl and N-Glycyl Amino Acids

Using a quadrupole ion-trap mass spectrometer with an electrospray ionization source, the Cooks kinetic method has been used to measure the lithium and sodium ion binding energies of the N-acetyl and N-glycyl derivatives of a series of 14 amino acids. For comparison, the gas-phase basicities of the amino acid derivatives were also determined by the kinetic method. The lithium binding free energies range from 47.2 to 56.4 kcal/mol, and the sodium affinities from 30.8 to 41.2 kcal/mol. Comparisons between basicities and metal ion binding energies indicate that the presence of a coordinating group (e.g., −OH, −CO2H, etc.) in the amino acid side chain can significantly increase the lithium and sodium binding energies. Dynamics calculations (CHARMm) confirm that side-chain coordination is a common stabilizing effect in the metalated systems. A good correlation, with a slope near unity, is found between the metal ion binding energies of the N-acetyl and N-glycyl derivatives. This indicates that the two groups o...
FURTHER DEVELOPMENT OF THE THEORY OF INTERNAL BUCKLING OF MULTILAYERS

The approximate theory of internal buckling of multilayers is obtained by a direct method and generalized to nonsinusoidal deformations. The numerical discussion includes the case of unequal thickness of competent and incompetent layers. Simple expressions are derived for the dominant wave length for rigid confinement or self-confinement showing the influence of interstitial flow. The theory is presented in the context of viscous media using both solid and fluid mechanics and is valid for large compressive strain and moderate slopes. Its applicability to elastic and viscoelastic media is indicated.
State Management of River Dikes in Early China: New Sources on the Environmental History of the Central Yangzi Region

While it is generally believed that the agricultural colonization of the middle Yangzi wetlands began in Tang-Song times, newly discovered texts show that the early Han state administered river dikes in the region. The texts, which were written between 192 and 121 bce, calculate dike sizes in order to estimate corvee requirements for dike maintenance and discuss the area of new farmland to be created. Our picture of the early history of the Yangzi region has been distorted by the northern focus of early texts, but archaeological discoveries are correcting this bias and suggest that the conversion of the Central Yangzi lowlands to farmland began many centuries earlier than previously believed. On pense en general que la mise en valeur agricole des marais du moyen Yangzi a commence sous les Tang et les Song. Or, des textes recemment decouverts montrent que des le debut des Han l’Etat administrait des digues dans la region. Rediges entre 192 et 121 avant notre ere, ces textes contiennent des calculs sur les dimensions des digues servant a evaluer les besoins en travail corveable pour leur entretien, ainsi que des considerations sur la superficie de nouvelles terres cultivees a ouvrir. Alors que nous nous faisions une image de l’histoire ancienne du bassin du Yangzi deformee par les textes anciens, qui privilegient la Chine du Nord, les decouvertes archeologiques remettent les choses en perspective et suggerent que la mise en valeur des basses terres du moyen Yangzi a demarre de nombreux siecles plus tot qu’on ne croyait.
Adelic string N-point amplitudes☆

Abstract We derive an infinite set of relations connecting the amplitudes for N -string processes and ( N +1)-string processes, for p -adic, archimedean, and adelic strings. The adelic relations generalize the known adelic product formula for four-point amplitudes. Taken together, all the obtained relations appear to imply an extensive symmetry of string theory.
The induction of amitotic nuclear division by pseudorabies virus multiplying in single rabbit kidney cells.

Abstract Single rabbit kidney (RK) cells derived from 8- to 10-day-old monolayer cultures may undergo amitotic nuclear division after infection with pseudorabies (Pr) virus. This division is correlated with an increased synthesis of deoxyribonucleic acid (DNA). Single cells derived from 3-day-old cultures and X-ray irradiated cells derived from 10-day-old cultures, which do not respond to infection with an increased rate of DNA synthesis, also do not exhibit nuclear division. Experiments on the multiplication of Pr virus in single RK cells show that the latent period varies from 6 to 10 hours. Virus yields from individual cells range from 63 plaque-forming units (PFU) to 505 PFU per cell after 15 hours of incubation.
Non PN junction solar cells using carrier selective contacts

A novel device concept utilizing the approach of selectively extracting carriers at the respective contacts is outlined in the work. The dominant silicon solar cell technology is based on a diffused, top-contacted p-n junction on a relatively thick silicon wafer for both commercial and laboratory solar cells. The VOC and hence the efficiency of a diffused p-n junction solar cell is limited by the emitter recombination current and a value of 720 mV is considered to be the upper limit. The value is more than 100 mV smaller than the thermodynamic limit of VOC as applicable for silicon based solar cells. Also, in diffused junction the use of thin wafers (< 50 um) are problematic because of the requirement of high temperature processing steps. But a number of roadmaps have identified solar cells manufactured on thinner silicon wafers to achieve lower cost and higher efficiency. The carrier selective contact device provides a novel alternative to diffused p-n junction solar cells by eliminating the need for complementary doping to form the emitter and hence it allows the solar cells to achieve a VOC of greater than 720 mV. Also, the complete device structure can be fabricated with low temperature thin film deposition or organic coating on silicon substrates and thus epitaxially grown silicon or kerfless silicon, in addition to standard silicon wafers can be utilized.
Logistic map-based fragile watermarking for pixel level tamper detection and resistance

An efficient fragile image watermarking technique for pixel level tamper detection and resistance is proposed. It uses five most significant bits of the pixels to generate watermark bits and embeds them in the three least significant bits. The proposed technique uses a logistic map and takes advantage of its sensitivity property to a small change in the initial condition. At the same time, it incorporates the confusion/diffusion and hashing techniques used in many cryptographic systems to resist tampering at pixel level as well as at block level. This paper also presents two new approaches called nonaggressive and aggressive tamper detection algorithms. Simulations show that the proposed technique can provide more than 99.39% tamper detection capability with less than 2.31% false-positive detection and less than 0.61% false-negative detection responses.
Citric acid sensitivity in recurrent ulcerative (aphthous) stomatitis.

T UFTl has reported on a patient with recurrent ulcerative stomatitis in whom a marked sensitivity to citric acid was demonstrated as one, if not, the only, ct,iological factor in the recurrence of these lesions. Tuft suggests that allergy to this material might, be rcsponsiblc for lesions in ot,hcr pat,ients with this syndrome. Our study was dircct,ed at eraluat,ing the relationship of citric acid and several other mat,erials (which were described by Tuft as implicated also by virtue of their citric acid content or chemical relationship) in terms of a group of patients with documented recurrent ulcerative (aphthous) stomatitis. OLW criteria for selection of patients to be included in this group were as follows: Recurrent oral apht,hac, when observed at their inception (which is infrequent), are generally seen as vesicles. Usually, the lesions are recurring ulcers, commonly from 1 to 12 mm. in size but occasionally measuring 2 to 3 cm., appearing anywhere in the oral cavity. They are extremely sensitive and painful, and often t,hey are covered by necrotic membranes or exudates. The ulcers are most often round or oval, occasionally with irregular peripheries, and surrounded by an area of inflammation. Single or multiple lesions may recur periodically. The ulcers usually heal in from ten to fourteen days, but they arc soon followed by new lesions or crops of lesions. An important differential diagnostic criterion is the absence of dermatologic lesions relatable to the oral aphthae. The clinical picture of patients with recurrent ulcerative stomatitis does not include the genit,al or c-ye symptoms characteristic of Behset’s syndrome or the skin lesions of erythema multiforme exudativum or pemphigus.
Carcinoid tumours: predicting the location of the primary neoplasm based on the sites of metastases

To predict the primary neuroendocrine tumour of the gastrointestinal tract site based on observed metastatic sites. We studied data from the radiology database of a single, large cancer centre on 250 patients with pathologically confirmed neuroendocrine tumours. Primary tumour sites and the locations of metastases were collected from pathologic and radiologic reports of all available imaging modalities, such as computed tomography (CT), positron emission tomography (PET/CT), magnetic resonance imaging (MRI) and octreotide scans in the database. A nominal regression model was used to predict primary tumour site using the observed metastatic sites. Regression coefficients that were not statistically significant at the 5 % level were eliminated from the model in a stepwise procedure. Lung and liver metastases were not statistically significant predictors of the location of primary tumours (p = 0.86 and 0.074, respectively); whereas, lymph node, bone, and peritoneal metastases were significant predictors (p < 0.0001, 0.0004, and 0.014, respectively). Metastatic neuroendocrine tumours to the lymph nodes, bone, and peritoneum can be used to predict the primary neuroendocrine site; however, metastases in the lung and liver alone cannot predict the site of the primary tumour site. • Imaging helps one to diagnose the location of primary neuroendocrine neoplasm and the associated metastases. • Diffuse metastatic disease often makes identification of the primary difficult. • A prediction model developed may help identification of the primary in this setting. • It may also help identify occult metastases and thereby assist in management.
Web services as the foundation for learning complex software system development

A significant challenge for Computer Science departments is how best to get new graduate students involved with their chosen research projects. Ideally, the incoming graduate students will as a whole have both a solid understanding of computing principles behind large-scale software development and a broad "skill set", e.g., for conducting systems-oriented research. This rarely occurs, due to the diversity of backgrounds of incoming students--even the most qualified applicant can have deficiencies. To address this problem, we have developed a first-year graduate course that balances and integrates practical considerations with basic principles of complex software system development. To make the discussions of designing, implementing, and evaluating complex software systems more concrete, we situate the core of the class in the context of Web Services. We are currently teaching this class for the second time, and, while there will always be open issues given the nature and scope of this class, we have received positive feedback from the students and the other members of the department. Students recognize the practicality of Web Services. Students also appreciate the research possibilities that arise while evaluating the state of the art with regard to Web Services.
Cross Structures and Cover Response in Gulf of Suez Tilt Blocks: ABSTRACT

Two studies along the west bank of the Gulf of Suez show that: (1) complex cross structures control the subcrop pattern and synorogenic facies; (2) brittle faulting in the preorogenic rocks gives way to more plastic behavior in overlying units; and (3) secondary normal faults sole within the cover but reflect underlying fault patterns. Gebel Zeit is the eroded crest of a major horst block, exposing Precambrian through Recent rocks. Internal structures include gulf-parallel faults, normal cross faults, and complex keystone grabens. Internal faulting, in conjunction with erosion, controls the reservoir subcrop pattern and synorogenic facies, including location of porous reefs. The Ras Issaran horst system exposes Miocene to Recent deformed sediments. Continuing movements on cross faults control synorogenic clastic facies and reef locations. Reversal of movement direction on cross faults is common. Even through thick cover, the internal breakup of the horst is discernable. The role of secondary cover faulting has been neglected in the Gulf of Suez. At Gebel Zeit, brittle faulting in the rigid preorogenic rocks dampens out as less pronounced faulting and folding in the plastic Miocene cover. At Ras Issaran, faults in the brittle Plio-Pleistocene clastics apparently sole in underlying evaporites. While these faults are decoupled from the underlying primary structures, they mimic the concealed fault pattern and provide clues to later movements of these faults. More detailed investigation of the internal breakup of horsts and the role of secondary faulting in the Gulf is needed. End_of_Article - Last_Page 515------------
Origin of the septum in the canid auditory bulla: Evidence from morphogenesis

Morphogenesis of the intrabullar septum in Canis lupus Linnaeus, 1758 and Vulpes vulpes (Linnaeus, 1758), as well as the definitive septal morphology within the family, demonstrate that no bone of the auditory bulla bends its edge inwards the bulla to produce a septum.
Decreases by disturbance-dependent tree species in the eastern and central USA

Open pine and oak forest ecosystems and floodplain forests have declined because of fire and flooding suppression. I determined tree species that have contracted in area occupied (where area occupied was ≥0.5 % of total species composition) or decreased in percent composition (i.e., percentage of all stems) during recent surveys (2000–2013) to ≤85 % of area occupied or composition during older surveys (1968–1999). I then identified whether species were associated with frequent fire, flooding, wetlands, postfire conditions, or other disturbances. Of 35 species that decreased in area occupied or composition, 16 species were associated with fire or postfire disturbance and fire-dependent species decreased in composition from 20 to 14 % during tree surveys. Even though species of floodplain forests and wetlands comprise a small percent of overall tree composition, 12 decreasing species were associated with floodplain forests or wetlands. Fire maintains open oak and pine ecosystems and flooding maintains floodplain forests, generally suspending succession. Suppression of fire in upland forests and flooding in floodplain forests has allowed disturbance-sensitive species to remain established and advance successional forests throughout the USA.
Pathophysiological changes in urine and blood from calves experimentally infected with Sarcocystis cruzi

Two 8-week experiments were conducted to determine the relationships between nutritional stress and pathophysiological changes in male Holstein calves infected with Sarcocystis cruzi. Calves were infected by oral inoculation with 200 000 S. cruzi sporocysts. In the first experiment weight gain reduction was greatest in inoculated calves during weeks 4 and 5 after inoculation. Feed intake was reduced during the 5th week. Erythrocyte count was reduced during week 5 and haemoglobin was reduced during week 6. The 24-h excretion of urinary and urea nitrogen from the inoculated calves was increased by treatment. In the 2nd experiments, both the feed-restricted and inoculated calves lost weight during weeks 4 and 5; feed intake was lower from week 5 to 8 inclusive. Urine volume from inoculated calves was lower during week 8. Lower urine excretions of sodium and potassium resulted from S. cruzi inoculation. There was a non-significant trend for higher urinary zinc excretion in the inoculated group during week 4. Urine nitrogen excretion from inoculated calves was higher during week 6. The urinary excretion of 3-methylhistidine from the inoculated calves was higher during week 4 and excretion of guanine was higher during weeks 4, 5 and 8. S. cruzi has several specific pathophysiological effects on calves beyond those induced by nutritional stress.
Comparative molecular field analysis of in vitro growth inhibition of L1210 and HCT-8 cells by some pyrazoloacridines

In vitro screening of a number of 2-(aminoalkyl)-5-nitropyrazolo[3,4,5- kl]acridines has previously indicated (Sebolt, J.S.; et al. Cancer Res. 1987, 47, 4299-4304) that these compounds, in general, exhibit selective cytotoxicity against the human colon adenocarcinoma, HCT-8, cell line, relative to mouse leukemia L1210 cells. Comparative molecular field analysis (CoMFA) was applied to HCT-8 and L1210 growth inhibition assays (IC50s) of a series (44) of the pyrazoloacridine derivatives with the objective of predicting improved solid tumor selectivity. In the absence of crystallographic data, the 9-methoxy derivative (15), which is currently in clinical study, was selected as the template molecular model. Two different structural alignments were tested: an alignment of structures based on root mean square (RMS)-fitting of each structure to 15 was compared with an alternative strategy, steric and electrostatic alignment (SEAL). Somewhat better predictive cross-validation correlations (r2) were obtained with models based on RMS vis-a-vis SEAL alignment for both sets of assays. A large change in lattice spacing, e.g., 2 to 1 A, causes significant variations in the CoMFA results. A shift in the lattice of half of its spacing had a much smaller effect on the CoMFA data for a lattice of 1 A than one of 2 A. The relative contribution of steric and electrostatic fields to both models were about equal, underscoring the importance of both terms. Neither calculated log P nor HOMO and/or LUMO energies contribute to the model. Steric and electrostatic fields of the pyrazoloacridines are the sole relevant descriptors to the structure-activity (cross-validated and conventional) correlations obtained with the cytotoxic data for both the L1210 and HCT-8 cell lines. The cross-validated r2, derived from partial least-squares calculations, indicated considerable predictive capacity for growth inhibition of both the leukemia and solid-tumor data. Evidence for the predictive performance of the CoMFA-derived models is provided in the form of plots of actual vs predicted growth inhibition of L1210 and HCT-8 cells, respectively, by the pyrazoloacridines. The steric and electrostatic features of the QSAR are presented in the form of standard deviation coefficient contour maps of steric and electrostatic fields. The maps indicate that increases or decreases in steric bulk that would enhance growth inhibition of HCT-8 cells would likewise promote growth inhibition of L1210 cells. Contour maps generated to analyze the electrostatic field contributions of the pyrazoloacridines to growth inhibition provide an essentially similar set of results.(ABSTRACT TRUNCATED AT 400 WORDS)
Hyperoctahedral Operations on Hochschild Homology

Abstract We construct Families {ρ l, k n } of orthogonal idempotents of the hyperoctahedral group algebras Q [ B n ], which commute with the Hochschild boundary operators b n =∑ n i=0 (−1) i d i . We show that those idempotents are projections onto some hyperoactahedral symmetric powers of the free Lie algebra Lie ( l, k ) n ( A ). The commutations above then decompose the Hochshild homology H n ( C ) obtained by any functor C : Δ op → K - module that factor through Fin ′ B , the hyperoctahedral category. Moreover, we show that this decomposition is the finest possible for any such functor. In particular, the Hochschild homology of a commutative algebra equipped with an involutive automorphism splits into components indexed by ( l, k ) and the corresponding Harrison homology splits into two components indexed by (0, 1) and (1, 0). Generalizing the Harrison complex, we show that H ( l,k ) n ( C )≅ H n (Sh ( l,k ) . /Sh ( l −1, k +1) . , where Sh ( r,s ) . are some shuffle complexes associated to C . We also give the characters of the representations related to Lie ( l, k ) n ( A ) as a direct sum of induced characters.
The polarization impedance of common electrode metals operated at low current density.

The objective of this study was to characterize the polarization impedance (resistance and capacitance) of several common metal/0.9% saline interfaces operated at low-current density and to thereby provide a useful reference for those wishing to calculate the impedance of such electrodes. The series-equivalent resistance (R) and capacitive reactance (Xc) of stainless steel, platinum, silver, MP35N, palladium, aluminum, rhodium and copper electrodes, all having a surface areas S=0.005 cm2 and all in contact with 0.9% saline, were measured as a function of frequency (100 Hz to 20 kHz) at low-current density (0.025 mA/cm2). For all the metals tested, both R and Xc decreased with increasing frequency and the relationships were linear on a log-log plot. That is, R and Xc exhibited power-law behavior (R=A/fα and Xc=B/fβ). However, it was not generally true that A=B and α=β=0.5 as stated in the Warburg low-current density model. Furthermore, the Fricke constant phase model in which α=β and ϕ=0.5πβ was found not to be applicable in general. In particular, the constraint that α=β was a good approximation for most of the metals tested in this study, but the constraint that ϕ=0.5πβ did not hold in general. Although the Warburg low-current density model provides a useful conceptual tool, it is not the most accurate representation of the electrode-electrolyte interface. The Fricke constant phase model is a better representation of electrode behavior, but it also may not be valid in general. We have found that a better representation is provided by the general power-law model R=A/fα and Xc=B/fβ, where A, B, α, and β depend on the species of both the metal and electrolyte and A and B depend, in addition, on electrode area. Using this model and the data presented in this study, the impedance of an electrode-electrolyte interface operated at low-current density may be calculated as $$Z = (0.005/S)\sqrt {(Af^{ - \alpha } )^2 + (Bf^{ - \beta } )^2 } ,$$ where S is the surface area of the electrode in cm2.
v-src activation of the collagenase-1 (matrix metalloproteinase-1) promoter through PEA3 and STAT: requirement of extracellular signal-regulated kinases and inhibition by retinoic acid receptors.

Collagenase-1 (matrix metalloproteinase-1 (MMP-1)) degrades the extracellular matrix and enhances the invasive phenotype of tumor cells. v-src activated MMP-1 transcription through a series of elements in the proximal promoter, including the E2BP (nt-172), polyoma virus enhancer A3 (PEA3) (nt-94), activator protein-1 (AP-1) (nt-72), and signal transducer and activator of transcription (STAT) (nt-57) consensus sites. Of these sites, PEA3 and STAT contributed specifically to induction by v-src, whereas the remaining elements were also involved in induction by the phorbol ester phorbol myristate acetate (PMA). However, in contrast to MMP-1 induction by PMA, an AP-1 site located at nt-186 did not contribute to v-src induction. These results suggest divergence of the tyrosine kinase– and protein kinase C–dependent pathways with respect to MMP-1 transcription. v-src induced MMP-1 through mitogen-activated protein kinases, with extracellular signal–regulated kinases playing a larger role than c-jun N-terminal kinase. Retinoic acid, which inhibits the progression of certain cancers, repressed v-src–induced MMP-1 transcription. Constitutive expression of retinoic acid receptors (RARs) α or β, but not γ, or of retinoid X receptor α, repressed v-src–induced collagenase-1 transcription. We concluded that oncogenic induction of MMP-1 by v-src depends on signaling pathways and cis-acting sequences that are distinct from those involved in phorbol ester activation. Furthermore, v-src induction of MMP-1 may, by acting in concert with other genes, enhance matrix degradation and tumor progression, and retinoic acid and RARs may antagonize this induction in an RAR type–specific manner. Mol. Carcinog. 21:194–204, 1998. © 1998 Wiley-Liss, Inc.
Improving interacting residue prediction using long-distance information in hidden Markov models

Identification of interacting residues involved in protein-protein and protein-ligand interaction is critical for the prediction and understanding of the interaction and has practical impact on mutagenesis and drug design. In this work, we introduce a new decoding algorithm, ETB-Viterbi, with early trace back mechanism built into interaction profile hidden Markov models (ipHMMs) that can incorporate the longdistance correlations between interacting residues to improve prediction accuracy. The method was applied and tested to a set of domain-domain interaction families from the 3DID database, and showed statistically significant improvement in accuracy measured by F-score. To gauge and assess the method's effectiveness in capturing the correlation signals, sets of simulated data based on the 3DID dataset with controllable correlation between interacting residues were also used, and it was demonstrated that the prediction consistently improves as the correlations increase.
A stable plasma lipoprotein and lecithin cholesterol acyltransferase control material.

Abstract Fresh fasting plasma collected over EDTA was quick frozen and stored in liquid nitrogen. Ten aliquots were thawed over an 18-month period and phospholipids, cholesterol, triglycerides, lipoproteins and lecithin cholesterol acyltransferase were quantitated. There was no evidence that any of the parameters measured changed with time indicating that the plasma lipoproteins were stable. This method of preserving plasma lipoproteins is proposed as a means of obtaining reference materials that may be used to control day-to-day laboratory error and for comparison of methods between laboratories.
"Cold spot" on bone scan at the site of primary osteosarcoma.

A 5-year-old girl presented with a rapidly growing osteosarcoma of the proximal right tibia. The radiographically osteoblastic lesions appeared as a ‘cold’ on the 99mTc-MDP bone scan. Possible explantations for this unusual finding on the bone scan are discuessed.
High School Student Perceptions of the Utility of the Engineering Design Process: Creating Opportunities to Engage in Engineering Practices and Apply Math and Science Content

Research and policy documents increasingly advocate for incorporating engineering design into K-12 classrooms in order to accomplish two goals: (1) provide an opportunity to engage with science content in a motivating real-world context; and (2) introduce students to the field of engineering. The present study uses multiple qualitative data sources (i.e., interviews, artifact analysis) in order to examine the ways in which engaging in engineering design can support students in participating in engineering practices and applying math and science knowledge. This study suggests that students better understand and value those aspects of engineering design that are more qualitative (i.e., interviewing users, generating multiple possible solutions) than the more quantitative aspects of design which create opportunities for students to integrate traditional math and science content into their design work (i.e., modeling or systematically choosing between possible design solutions). Recommendations for curriculum design and implementation are discussed.
Hydrophobic Residues Phe751 and Leu753Are Essential for STAT5 Transcriptional Activity

Abstract One facet of cytokine signaling is relayed to the nucleus by the activation, through tyrosine phosphorylation, of latent cytoplasmic signal transducers and activators of transcription (STAT) family members. It has been demonstrated that the C termini of STATs contain the transactivation domain and are essential for the transactivation of target genes. To better understand the function of the STAT C terminus, we have generated a series of C-terminal mutants in STAT5a and examined their effects on transactivation, tyrosine phosphorylation, and DNA binding. Using GAL4 chimerae with the C terminus of STAT5, we have defined a 12-amino acid region essential for STAT5 transactivation. Surprisingly, deletion of these 12 amino acids in the context of the native STAT5 backbone preserved the overall transcriptional activity of the protein. Further analysis revealed that deletion of this region resulted in hyper-DNA binding activity, thus compensating for the weakened transactivation domain. Using site-directed mutagenesis, we show that within this 12-amino acid region the acidic residues were non-essential for transactivation. In contrast, the non-acidic residues were crucial for transactivation. Mutating either Phe751 or Leu753 to alanine abolished transactivation suggesting that these residues were essential for connecting STAT5 to the basal transcriptional machinery.
Periauricular Cysts and Sinuses

Periauricular cysts, sinuses, and fistulas occur commonly in the pediatric population. They arise from developmental defects of the first branchial cleft and first branchial arch. In most instances the diagnosis and management of these conditions are straightforward, but exceptional presentations sometimes occur. Failure to recognize these unusual cases may result in inadequate treatment and subsequent recurrence, and even if the correct diagnosis is made, surgical management of these lesions may be complicated. A series of 15 cases of periauricular congenital lesions is reviewed, of which three cases illustrating a diagnostic or surgical challenge are presented. The embryology, presentation, and management of these anomalies are discussed. This is one of the largest series of first branchial cleft anomalies reported in the literature, and our paper uniquely discusses first branchial cleft anomalies and preauricular sinuses together, with an emphasis on the surgical management of facial nerve, external ear, and middle ear involvement.
Interaction between active and passive knee stabilizers during level walking

The gait of normal subjects and patients with varus deformities at the knee was studied by analyzing the interaction between the dynamic (muscular) and passive (ligamentous) restraints affecting lateral stability of the knee. A statistically determinant model predicted that the midstance-phase adducting moment during normal gait would cause lateral knee joint opening if either antagonistic muscle force and/or pretension in the lateral soft tissues were not present at the knee. The patient group tended to compensate for a high midstance-phase adducting moment by walking with a style of gait that demanded more muscle force (greater flexion-extension moments). This walking style reduced the chance of lateral joint opening. It can be speculated that this style of gait would help to maintain equilibrium at the knee. The higher muscle force would aid in resisting the adducting moment, keeping the joint closed laterally and thus increasing the stability of the knee.
The effects of KCl and NaCl additions on certain physical properties of CsCl

Abstract The effects of KCl and NaCl additions on the melting point, solid phase transition, and thermal expansion of CsCl were examined. The CsCl solid phase transition was observed in samples containing as little as 10 wt% CsCl. The addition of KCl or KCl+NaCl lowered the temperature at which the phase transition began as much as 170 °C.
The Two-Stream Instability Studied with Four One-Dimensional Plasma Simulation Models

Four one-dimensional plasma simulation models have been compared with regard to the electrostatic two-stream instability. The primary reason for making these comparisons was to determine the extent to which physical results depend on numerical method for a problem in which collective effects dominate. Previously, Lewis, Sykes, and Wesson compared these four simulation models using a stable double-streaming situation as a test problem. In that case the comparisons were with regard to collisional effects, energy conservation, and momentum conservation; however, because a stable test problem was used, only tentative conclusions could be drawn as to the comparison among the models when they are applied to a problem in which collective effects dominate. We have applied the models to compute the evolution of a two-stream instability and compared the time dependence of the electric energy as determined by each of the models. The models are characterized by the representation of the electric potential and by how the electric field is computed from the potential; both linear and quadratic splines are used to represent the potential or field. The major result of our comparisons is that the evolution of the electric energy of a two-stream unstable plasma does not depend strongly on the choice of model. There is a much stronger dependence on the random numbers that are chosen to represent the initial distribution function in phase space.
Lacrimal gland malignant mixed tumors (carcinomas arising in benign mixed tumors): A clinico‐pathologic study

Six cases of a rare entity, lacrimal gland malignant mixed tumor (MMT), or carcinoma arising in benign mixed tumor (BMT), are presented. Clinically, 2 patients had a long history of orbital protrusion, which recently had progressed more rapidly, In 2 other cases, the carcinomas evolved after recurrences of BMT. Two other patients experienced the recent onset of symptoms, without a known tumor previously having been present. Clinical clues suggesting a malignant neoplasm of a lacrimal gland include 1) recent rapid onset of symptoms (orbital protrusion, eyelid swelling; 2) presence of pain; and 3) radiographic studies showing bone destruction. In each of our cases, histologic examination demonstrated a BMT as well as a carcinoma (undifferentiated or poorly differentiated adenocarcinoma; in 1 case, areas of adenoid cystic carcinoma were identified). Problems in histopathologic diagnosis are explored. (BMT, recurrent BMT, in situ carcinoma in BMT and MMT are differentiated.) The management of lacrimal gland tumors is discussed. For a suspected malignant neoplasm, a biopsy through the eye lid to establish the diagnosis is recommended. Radical orbital exenteration should be performed for malignant mixed tumors, which have a poor prognosis.
Characterization of poly(1,4-phenyleneterephthalamide) in concentrated sulphuric acid. 2: Determination of molecular weight distributions

Abstract By combining static and dynamic properties (Mw, A2, kd Rg and Rh) of poly(1,4-phenyleneterephthalamide), PPTA (commercially known as Kevlar), with a detailed analysis of measured time correlation functions at different scattering angles in dilute solution, we have been able to estimate the molecular weight dependence of the radius of gyration, Rg(M), the persistence length ϱ ( ≈ 290 A ), and the molecular weight distribution (Mz:Mw:Mn ≈ 6.2:1.8:1) using an unfractionated PPTA sample (Mw = 4.3 × 104 g/mole). Laplace inversion of the time correlation function was accomplished independently by means of two different algorithms: the singular value decomposition technique with discrete multi-exponentials to approximate the normalized characteristic linewidth distribution function G(г) and the method of regularization whereby a linearized smoothing operator was used. The non-intrusive laser light scattering technique permits us to characterize, for the first time, the molecular weight distribution of PPTA which has been difficult to perform by means of other more established methods, such as size exclusion chromatography, because of the corrosive nature of solvents used in preparing PPTA solutions.
Solid state ultraviolet laser (213 nm) ablation of the cornea and synthetic collagen lenticules

We used a Q-switched Nd:YAG laser with non-linear optical crystals to produce the 5th (213 nm) and the 4th (266 nm) harmonic frequencies. Using these two wavelengths, we ablated fresh porcine corneas and type I collagen synthetic epikeratoplasty lenticules. For the 213-nm ablation, radiant exposure was 1.3 J/cm2. The ablation rate was 0.23 micron per pulse for the epikeratoplasty lenticules. We examined all tissues with light microscopy, transmission electron microscopy, and scanning electron microscopy. Histology for the 213-nm ablation showed a clean ablation crater with minimal collagen lamellae disruption and a damage zone less than 1 micron. In comparison, the 266 nm radiation showed more charring at the edges with a damage zone approximately 25 microns deep with disruption of the stromal lamella. Our results show that this solid state UV laser is a potential alternative to the excimer laser for cornea surgery.
The ACC at 50 : A giant grew in Bethesda: The impact of the ACC on cardiovascular medicine

Before 1948, the American Heart Association (AHA) served as the professional society for physicians interested in cardiovascular medicine. Largely in response to a decision by the AHA to become a voluntary health organization dedicated primarily to cardiovascular research and public education, the
Kinetically-induced hexagonality in chemically grown silicon nanowires

Various silicon crystal structures with different atomic arrangements from that of diamond have been observed in chemically synthesized nanowires. The structures are typified by mixed stacking mismatches of closely packed Si dimers. Instead of viewing them as defects, we define the concept of hexagonality and describe these structures as Si polymorphs. The small transverse dimensions of a nanowire make this approach meaningful. Unique among the polymorphs are cubic symmetry diamond and hexagonal symmetry wurtzite structures. Electron diffraction studies conducted with Au as an internal reference unambiguously confirm the existence of the hexagonal symmetry Si nanowires. Cohesive energy calculations suggest that the wurtzite polymorph is the least stable and the diamond polymorph is the most stable. Cohesive energies of intermediate polymorphs follow a linear trend with respect to their structural hexagonality. We identify the driving force in the polymorph formations as the growth kinetics. Fast longitudinal elongation during the growth freezes stacking mismatches and thus leads to a variety of Si polymorphs. The results are expected to shed new light on the importance of growth kinetics in nanomaterial syntheses and may open up ways to produce structures that are uncommon in bulk materials.