cssi/SciSciGPT-SciSciNet huggingface dataset:
Caves as sources of biotic remains in arid western North America

Abstract Caves have been a valuable source of paleoenvironmental information since the eighteenth century. In arid portions of western North America, caves have replaced small lakes as the primary source of biotic remains of Quaternary age. Packrat middens, dung of extinct animals, pollen, and archeological artifacts are excellently preserved. Aridity of the sediment, which is influenced by the cave's topographic position, internal morphology, and the regional climate, is the primary cause of good preservation. For stratigraphic pollen analysis, the best sites are those without internal moisture sources and without extensive bioturbation. Pollen samples should be taken near the center of the chamber, where eolian deposition is most rapid. Pollen concentrations in cave sediment are lower (2000–355,000 grains g−1) than in lake sediment, and pollen percentages in cave sediment differ from those in packrat middens due to additional transport mechanisms (on plant tissue and on the packrats themselves) for middens. Pollen diagrams for Bechan Cave, Utah, and Organ Pipe Cactus National Monument, Arizona are presented as examples of cave sediment and packrat midden analysis.
Racial differences in hypertension-associated red cell sodium permeability

The prevalence and severity of essential hypertension varies greatly among human populations. Some of this variation is undoubtedly due to differences in dietary Na+ levels1. However, even within groups which consume large amounts of salt, not all members develop increased blood pressure. Furthermore, the clinical expression of hypertension varies among races, and American blacks have particularly severe symptoms. These observations, in addition to a familial pattern in the occurrence of essential hypertension, suggest important genetic influences. Recent studies, primarily of northern European populations, have demonstrated abnormal erythrocyte Na+ transport in affected individuals2–5 and in approximately half the members of kindreds founded by a hypertensive progenitor4,5. We have found that red cell Na+ transport can be assessed simply by measuring the unidirectional passive influx of 22Na+ into ouabain-treated erythrocytes5 and have applied this technique to American blacks with essential hypertension. The results suggest a complete absence of the abnormal erythrocyte Na+ transport which is characteristic of white patients with essential hypertension. Thus, among American blacks, essential hypertension may have either a different genetic basis or a substantially different expression.
Abstract 2303: The potential role of nonhypoxic HIF-1 in HER2-mediated aromatase inhibitor resistant breast cancer

Although aromatase inhibitors (AIs; i.e., letrozole) have been shown to be highly effective in treating estrogen receptor positive (ER+) breast cancer, a significant percentage of patients either do not respond to AIs or become resistant to them. Studies suggest that resistance to AIs involves a switch from dependence on ER signaling to dependence on growth factor-mediated pathways, such as epidermal growth factor receptor (EGFR)/HER2. The mechanism by which HER2 is involved in AI resistance remains unclear. It is, therefore, important to elucidate the HER2-mediated pathway that contributes to AI resistance, and to identify other relevant factors involved that can be used as biomarkers of AI resistance and targets for therapy. One such factor may be HIF-1, a heterodimeric transcription factor made up of an inducible alpha (α) subunit and a constitutively expressed beta (β) subunit. HIF-1 regulates genes important for cell survival, metabolic adaptation, and angiogenesis. Oxygen (O 2 ) tension is a well-known regulator of HIF-1α, but other factors independent of O 2 can also regulate it. Previous studies have shown that transfecting HER2 into cells and activation of kinase pathways increase HIF-1α expression and/or activity. Unlike the well-studied role of hypoxia-regulated HIF-1α in a variety of cancers, nonhypoxic regulation of HIF-1α and its role in cancer remains largely unclear. Here we have investigated HIF1α in AI resistance. Preliminary results indicate that basal HIF-1α protein expression is 3-fold (p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2303. doi:10.1158/1538-7445.AM2011-2303
Nativity status/length of stay in the US and excessive gestational weight gain in New York City teens, 2008-2010.

Nativity status/length of stay in the US has been found to be associated with obesity. However, little work has examined the role of nativity status/length of stay in excessive gestational weight gain (EGWG) in adolescents. This study utilized New York City Department of Health and Mental Hygiene birth certificate data in a cross-sectional analysis of 15,715 singleton births to primiparous teen mothers (12–19 years) between 2008 and 2010. Nativity and length of stay in the United States (US) were obtained from birth certificates. EGWG was calculated using weight at delivery and pre-pregnancy weight. Prevalence ratios were calculated through generalized estimating equations to assess the strength of the association between nativity status/length of US residence and EGWG. For US-born teens, 43 % gained more weight than recommended as compared to 32 % for foreign-born teens who have lived in the US for less than 5 years (FB <5 years). Following adjustment for maternal demographics and other factors, US-born teens (adjusted prevalence ratios (APR) (CI) 1.26 [1.18,1.34]), FB 10+ years (APR (CI) 1.17 [1.07,1.28]), and FB 5–10 years (APR (CI) 1.11 [1.01,1.21]) were more likely to have gained weight excessively as compared to FB <5 years. US-born teens and FB teens that have been in the US longer than 5 years are more likely to gain weight excessively during pregnancy as compared to teens with fewer than 5 years in the US. These results identify a critical period when adolescents are in frequent contact with health care providers and can receive counseling regarding healthy weight gain.
Candidate plasma-facing materials for extreme ultraviolet lithography source components

Material selection and lifetime issues for extreme ultraviolet (EUV) lithography are of critical importance to the success of this technology for commercial applications. This work reviews current trends in production and use of plasma-facing electrodes, insulators, and wall materials for EUV-type sources. Ideal candidate materials should be able to: withstand high thermal shock from the short pulsed plasma; withstand high thermal loads without structural failure; reduce debris generation during discharge; and be machined accurately. We reviewed the literature on current and proposed fusion plasma-facing materials as well as current experience with plasma gun and other simulation devices. Both fusion and EUV source materials involve issues of surface erosion by particle sputtering and heat-induced evaporation/melting. These materials are either bare structural materials or surface coatings. EUV materials can be divided into four categories: wall, electrode, optical, and insulator materials. For electric discharge sources, all four types are required, whereas laser-produced plasma EUV sources do not require electrode and insulator materials. Several types of candidate alloy and other materials and methods of manufacture are recommended for each component of EUV lithography light sources.
Supplemental bonding in the Gulf of Mexico: the potential effects of increasing bond requirements

The Minerals Management Service (MMS) requires offshore oil and gas operators to procure surety bonds to ensure that they meet their decommissioning obligations. According to recent estimates developed by the authors, the total undiscounted cost of decommissioning structures and wells in the Gulf of Mexico in less than 500 ft. water depth is estimated to range between $18-63 billion. The MMS is currently reviewing and updating their supplemental bonding requirements, and in this paper, we discuss the potential impacts of an increase in the bond levels required. While the size of the increase will depend on the amount of risk MMS will assume, the average cost of plugging and abandonment and structure removal operations are between two and eight times greater than the current bond formula. We analyse the surety market, the companies involved in writing bonds and the approximate market share of organisations. This information is neither widely known nor well understood outside a few individuals specialising in the area. We conclude that the largest impacts of increased supplemental bonding requirements would be for exploration and production companies with approximately $10 to $20 million in current liabilities. [Received: April 08, 2009; Accepted: May 26, 2009]
Realistic Realizations Of Threshold Circuits

Threshold logic, in which each input is weighted, has many theoretical advantages over the standard gate realization, such as reducing the number of gates, interconnections, and power dissipation. However, because of the difficult synthesis procedure and complicated circuit implementation, their use in the design of digital systems is almost nonexistant. In this study, three methods of NMOS realizations are discussed, and their advantages and shortcomings are explored. Also, the possibility of using the methods to realize multi-valued logic is examined.
Comparison of Economic Optimum Nitrogen Rates for Rice in Arkansas

Historically high N prices have increased farmer interest in economic optimum N rates for rice (Oryza sativa L.). This study uses five to 8 yr of rice variety by N data from four research locations in Arkansas varying by soil series [Perry clay (Vertic Haplaquepts); Sharkey clay (Vertic Haplaquepts); DeWitt silt loam (Typic Albaqualfs); and Hillemann silt loam (Thermic, Albic, Glossic Natraqualfs)] to estimate rice yield response to N functions for five common functional forms [quadratic, quadratic-plateau, square root, linear-plateau, and Mitscherlich]. Economic optimum N rates (EONs) are calculated by location and functional form across years using both nonlinear optimization and a numerical method proposed for making N rate guidelines in the Corn Belt of the United States. Statistical analysis indicated the quadratic fits the yield data best at three of four locations and performs as well as either the linear-plateau or quadratic-plateau at the fourth location. The numerical method produces approximately the same EON rates (within ±1 kg ha -1 ) as nonlinear optimization. Economic optimum N rates varied by research location and are as follows assuming average 2006-2008 rice price and N cost data and annual quadratic functions: 150 kg N ha -1 at the DeWitt silt loam location; 122 kg N ha -1 at the Hillemann silt loam location; 181 kg N ha -1 at the Sharkey clay location; and 187 kg N ha -1 at the Perry clay location.
Electromagnetic disintegration of the A = 3 and A = 4 nuclei

Abstract The photodisintegration and electrodisintegration of 3 H, 3 He, and 4 He are reviewed within the context of Faddeev type formalisms. The 2-body and 3-body breakup of the trinucleons are compared. Emphasis is placed upon E1 numerical results, although threshold EO electrodisintegration and nd thermal capture are discussed. Consideration of 4 He disintegration is limited to the 2-body breakup channels.
Positioning Error Induced By Axial Sampling In Positron Emission Tomography

A multi-slice Positron Camera organizes data as a set of parallel slices whose thickness is defined by the axial response function (ARF) of the tomograph. This ARF is usually not uniform and the sensitivity is maximum for a point source located at the center of the slice. As a consequence, the partial volume effect (quantitation loss for structures that are smaller than two to three times the FWHM resolution) will he dependent not only on the size of the structure but also on its relative position with regard to the ARF. We have developed a computer simulation to analyze this effect. Objects of different size and shape are examined and it is shown that on a system with a 6 mm axial resolution (FWHM), a shift of 3 mm can introduce more than 10% variation on the final measurement. The simulation is confirmed by experimental results on a high resolution PET. We conclude that positioning and repositioning must be handled with great care in order to make reproducible measurements and allow accurate partial volume corrections.
Regulation of Langerhans cell function via blood borne factor(s).

Abstract Langerhans cells (LC) are epidermal dendritic cells that are functionally labile. Freshly obtained LC (fLC) readily activate allogeneic T cells, but they are incapable of activating autologous T cells; and even when pulsed with antigen, they fail to activate naive, antigen-specific T cells. When fLC are cultured for 2–3 days in the presence of keratinocytes, LC swiftly up-regulate surface expression of class I and II MHC molecules, and express de novo the co-stimulatory molecules B7 and ICAM-1. In addition to displaying enhanced ability to activate allogeneic T cells, cultured LC acquire the novel functional property of activating autologous T cells. It is believed that keratinocytederived GM-CSF is the primary driving force responsible for the conversion of fresh to cultured LC in vitro. However, in vivo administration of GM-CSF, either intracutaneously or systematically, fails to induce LC to undergo functional transformation in situ. Moreover, despite a high level of GM-CSF in the circulation, fLC from mice bearing GM-CSF-producing tumors display no ability to activate syngeneic T cells. These observations suggest that a homeostatic factor that antagonizes the effect of GM-CSF may be present in vivo. To test this possibility, we have examined the functional properties of LC prepared from mouse skin that had been explanted in vitro for 3 days. We found that the functional and phenotypic features of these cells closely resembled those of LC cultured in single cell suspension: the cells strongly expressed B7-1 and B7-2, and displayed enhanced expression of class II MHC molecules; they readily activated naive autologous T cells. Strikingly, when explants or suspensions of fresh epidermal cells were cultured in the presence of 10% mouse serum they failed to acquire syngeneic T cell activating properties; and surface up-regulation of Ia and de novo expression of B7 was inhibited. However, the cultured cells still expressed surface Ia and readily activated allogeneic naive T cells. If mouse serum was added only during the last 24 h of culture, the LC displayed full functional transformation. Human, rabbit and bovine serum showed no inhibitory effect on mouse LC. Our data suggest that mouse serum contains a factor (or factors) that inhibits, in a species-specific manner, epidermal LC from undergoing functional transformation in vitro, and this factor may maintain epidermal LC in the ‘fresh’ functional program in vivo.
Stratospheric ozone chemistry on ice surfaces

Surface second harmonic generation (SHG) allows detailed molecular measurements on a surface previously difficult to study: the ice/vacuum interface in equilibrium with its vapor. The heterogeneous reaction ClONO2 + H2O yields HOCl + HNO3, a key reaction in ozone-depletion mechanisms in the Antarctic stratosphere, was followed on the basal ice surface maintained under stratospheric conditions (185 K, 10-4 Torr water). SHG signals characteristic of the product HOCl allow us to determine reaction kinetics at various ClONO2 exposures and temperatures and in the presence of co-adsorbates. We find that the reaction is autocatalytic in HOCl.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
cAMP-dependent Oncogenic Action of Rap1b in the Thyroid Gland *

cAMP signaling leads to activation and phosphorylation of Rap1b. Using cellular models where cAMP stimulates cell proliferation, we have demonstrated that cAMP-mediated activation, as well as phosphorylation of Rap1b, is critical for cAMP stimulation of DNA synthesis. To determine whether Rap1b stimulates mitogenesis in vivo, we have constructed a transgenic mouse where a constitutively active G12V-Rap1b, flanked by Cre recombinase LoxP sites, is followed by the dominant negative S17N mutant. Employing this novel mouse model, we have switched, in a tissue-specific (thyroid) and temporally controlled manner, the expression of Rap1b from a stimulatory to an inhibitory form. These experiments provide conclusive evidence that Rap1b is oncogenic in the thyroid in ways linked to transduction of the cAMP mitogenic signal.
A second reaction catalyzed by the tryptophan synthetase of Escherichia coli.

Abstract Evidence is presented suggesting that the tryptophan synthetase of Escherichia coli also participates in the conversion of indoleglycerol phosphate to indole. The protein immunologically related to tryptophan synthetase which is formed by certain mutants lacking tryptophan synthetase appears to be an altered form of this enzyme which still retains the ability to participate in indole formation from indoleglycerol phosphate but cannot convert indole to tryptophan.
Perceptual evidence for protracted development in monosyllabic Mandarin lexical tone production in preschool children in Taiwan

This study used the same methodology in Wong [J. Speech Lang. Hear. Res. 55, 1423–1437 (2012b)] to examine the perceived accuracy of monosyllabic Mandarin tones produced by 4- and 5-year-old Mandarin-speaking children growing up in Taiwan and combined the findings with those of 3-year-olds reported in Wong [J. Speech Lang. Hear. Res. 55, 1423–1437 (2012b)] to track the development of monosyllabic tone production in preschool children. Tone productions of adults and children were collected in a picture naming task and low-pass filtered to remove lexical information and reserve tone information. Five native-speakers categorized the target tones in the filtered productions. Children's tone accuracy was compared to adults' to determine mastery and developmental changes. The results showed that preschool children in Taiwan have not fully mastered the production of monosyllabic Mandarin tones. None of the tones produced by the children in the three age groups reached adult-like accuracy. Little developmental change was found in children's tone accuracy during the preschool years. A similar order of accuracy of the tones was observed across the three age groups and the order appeared to follow the order of articulatory complexity in producing the tones. The findings suggest a protracted course of development in children's acquisition of Mandarin tones and that tone development may be constrained by physiological factors.
On low-frequency estimates of long-run relationships in macroeconomics

Abstract A number of recent studies have attempted to test propositions concerning ‘long-run’ economic relationships by means of frequency-domain time-series techniques that concentrate attention on low-frequency comovements of variables. The present paper emphasizes that many of these propositions involve expectational relationships that are not inherently related to specific frequencies or periodicities. Thus the association of low-frequency time-series test statistics with long-run economic propositions is not generally warranted. That such an association can be misleading is demonstrated by analysis of examples taken from notable papers by Geweke, Lucas, and Summers.
Swine Lagoon Effluent as a Source of Nitrogen and Phosphorus for Summer Forage Grasses

Efficient crop utilization of N and P derived from anaerobic swine (Sus scrofa domesticus) lagoon effluent is critical to minimizing offsite nutrient movement. The objective of this study was to determine the effects of variable rates of swine lagoon effluent and fertilizer N and P on yield and nutrient utilization of forage grasses on an acid Vaiden silty clay (very fine, montmorillonitic, thermic, Vertic Hapludalf) and an alkaline Okolona silty clay (fine, montmorillonitic, thermic, Typic Chromudert). Treatments were multiple effluent irrigations resulting in four N and P rates from 0 to 665 and 0 to 94 kg ha -1 yr -1 N and P, respectively. Fertilizer treatments were also established at equivalent N and P rates. Similar growth responses were obtained for bermudagrass [Cynodon dactylon (L.) Pers.] or johnsongrass [Sorghum halepense (L.) Pers.] regardless of nutrient source. Application of either effluent or fertilizer at rates >448 kg N ha -1 did not effectively increase dry matter yield. Total N accumulation reflected both increasing dry matter yield and tissue N concentration while P accumulation depended primarily on increasing yield. Forage grass accumulation of N and P was similar between sources, but recovery efficiency for both elements declined with increasing rates. Similarity in N and P availability of effluent to fertilizer simplifies nutrient management although potential N loss by NH 3 volatilization is likely greater for effluent while fertilizer may result in greater end-of-season soil NO - 3 -N levels at equivalent rates of applied N.
Patterns of reading and organizing information in document triage

People engaged in knowledge work must often rapidly identify valuable material from within large sets of potentially relevant documents. Document triage is a type of sensemaking task that involves skimming documents to get a sense of their content, evaluating documents to assess their worth in the context of the current activity, and organizing documents to prepare for their subsequent use and more in-depth reading. We have performed a study of document triage by collecting multiple forms of qualitative and quantitative data to characterize how 24 subjects read about a new topic and assessed and organized a set of 40 relevant Web documents. Our results indicate that there are multiple strategies for document triage, each involving different styles of reading, interacting, and organizing. Common strategies include: 1) focused reading early in the task, relegating the organizing until later in the process; 2) skimming performed in tandem with organizing, which relies on gaining an incremental understanding of the topic; and 3) metadata-based organizing, a strategy that stresses working with document surrogates to minimize the time spent reading. The findings suggest ways applications may better support the intertwined nature of the browsing, reading, and organizing activities in document triage.
Mercury in the Chesapeake Bay

To elucidate the fate of mercury (Hg) and methylmercury (MMHg) in estuaries we have been studying the biogeochemical cycling of Hg in the Chesapeake Bay and its tributaries. Measurements of total Hg and mercury speciation (MMHg and dissolved gaseous Hg (DGHg)) have been made in the surface waters of the Chesapeake Bay system, including sampling transects into Baltimore Harbor, a region where sediment Hg concentrations can exceed 5 nmol g−1 and sediment MMHg concentrations approach 50 pmol g−1. Surface water Hg concentrations are typical of an impacted urban estuary that has a high suspended sediment load (SPM; typically >5 mg l−1), and for the upper Bay, where total Hg is generally 20 pM or less, particulate Hg is the dominant fraction. Total Hg concentrations tend to decrease down-estuary, and this is also true for the sub-estuaries (Potomac and Patuxent Rivers). This decrease coincides with a decrease in SPM, but urban inputs are also higher up-estuary. Measurement of total Hg and MMHg in the anoxic bottom waters that develop seasonally in the harbor demonstrate the increased concentration of Hg, and especially MMHg, under low oxygen conditions, and the most likely source is the release of these species from sediments. Both intensive studies and long-term measurements show that the concentration of DGHg is relatively low in this system (typically <0.2 pM) and DGHg is a small fraction of the total Hg. Based on the information available, a preliminary mass balance budget is constructed for the Chesapeake Bay. Direct atmospheric deposition contributes a substantial portion of the Hg to the Bay while sedimentary removal is the principal sink. Overall, 29% of the riverine and atmospheric inputs to the Bay is exported to the coastal ocean. Thus, the Bay is an efficient trap for Hg. The Bay is, however, a net source of MMHg suggesting that significant methylation of Hg occurs within the estuary. On a watershed scale, only about 5% of the total atmospheric deposition to the watershed is exported to the coastal ocean.
Deep-ocean field test of methane hydrate formation from a remotely operated vehicle

We have observed the process of formation of clathrate hydrates of methane in experiments conducted on the remotely operated vehicle (ROV) Ventana in the deep waters of Monterey Bay. A tank of methane gas, acrylic tubes containing seawater, and seawater plus various types of sediment were carried down on Ventana to a depth of 910 m where methane gas was injected at the base of the acrylic tubes by bubble stream. Prior calculations had shown that the local hydrographic conditions gave an upper limit of 525 m for the P-T boundary defining methane hydrate formation or dissociation at this site, and thus our experiment took place well within the stability range for this reaction to occur. Hydrate formation in free seawater occurred within minutes as a buoyant mass of translucent hydrate formed at the gas-water interface. In a coarse sand matrix the filling of the pore spaces with hydrate turned the sand column into a solidified block, which gas pressure soon lifted and ruptured. In a fine-grained black mud the gas flow carved out flow channels, the walls of which became coated and then filled with hydrate in larger discrete masses. Our experiment shows that hydrate formation is rapid in natural seawater, that sediment type strongly influences the patterns of hydrate formation, and that the use of ROV technologies permits the synthesis of large amounts of hydrate material in natural systems under a variety of conditions so that fundamental research on the stability and growth of these substances is possible.
Sound orientation behavior in cats. II. Mid‐frequency spectral cues for sound localization

The cat's head-related transfer function creates a directionally dependent mid-frequency notch in the amplitude spectrum of a broadband sound as the stimulus propagates to the tympanic membrane [Rice et al., Hear. Res. 58, 132-152 (1992)]. Our previous behavioral studies [May and Huang, J. Acoust. Soc. Am. 100, 1059-1069 (1996)] have indicated that the cat's sound-evoked orientation responses are well directed to the azimuth and elevation of broadband noise bursts in the frontal sound field, where pinna-based spectral notches are prominent and change systematically with sound direction. In the present study, the importance of mid-frequency directional cues in the cat's sound localization behavior was further evaluated by manipulating the frequency and bandwidth of orientation stimuli. The accurate pattern of orientation behavior seen previously with bursts of broadband noise was relatively unaffected when stimulus bandwidth was decreased to mid-frequency bandpass noise of 5-18 kHz. In contrast, poorly directed head orientation responses were observed in tests with high-pass noise (> 18 kHz) and mid-frequency pure tones. When tested with narrow bands of mid-frequency noise, cats oriented toward the spatial location where HRTF-filtering properties most closely matched the stimulus spectrum. These results suggest that important sound localization cues are derived from mid-frequency spectral features of the cat's HRTF.
Direct Measurement of Ultrafast Carbon−Carbon Cleavage Rates via the Subpicosecond Charge-Transfer Activation of Pinacols

Highly transient (benzpinacol) cation radicals (D2+•) and their ultrafast mesolytic fragmentations to the diarylhydroxymethyl radical (D•) and cation (D+) are directly observed on the early picosecond time scale upon the charge-transfer photoactivation of the intermolecular donor−acceptor complexes of pinacol donors with methyl viologen. Ultrashort lifetimes of the cation radicals with τ ≈ 10 ps obtain (for the first time) from quantitative kinetics analysis of the time-resolved spectroscopic results. These rapid C−C bond scissions successfully compete with back-electron transfer, which normally predominates on this time scale, and lead to exceptionally high efficiencies for the oxidative fragmentation of pinacols.
Pelvic neoplasms in children

The pelvis of the infant and child has different anatomic relationships than the adolescent or adult pelvis, and the knowledge of congenital anomalies of the rectum and bladder can assist in treating the primary neoplasms of the pelvis. The most common neoplasms are rhabdomyosarcomas of the bladder, prostate, and vagina; sacrococcygeal teratoma; and the germ cell tumors, including teratomas, endodermal sinus tumors, and the choriocarcinomas. Rapidly improving chemotherapy for all of these lesions has resulted in a changed role for the surgeon. Less radical resection of these tumors is being performed whereas it is necessary to have more precise histologic and genetic identification of the tumor and the specific anatomic location and extent of the tumor in the pelvis. Survival for all types of childhood pelvic neoplasms has improved dramatically under the influence of the combined children's cancer study groups, which have been functioning for the last 20 years. Because of the complexities of diagnosis and treatment of these pelvic neoplasms in childhood and because the survival rates have dramatically improved with the most current therapy, these children should be cared for in a children's center that is part of the major children's cancer study groups.
In Vitro Synergy Between Some Cationic Amphipathic Cyclooctapeptides and Antibiotics

The antimicrobial activities of some cationic amphipathic cyclooctapeptides in combination with select antibiotics are investigated. Accordingly, cyclooctapeptides (CPs 1–11) derived from the sequence cyclo[Leu-d-Leu-Leu-d-Leu-Lys-d-Lys-Lys-d-Lys] were tested against Escherichia coli and Staphylococcus aureus. Synergistic effects were evaluated in combination with tetracycline, chloramphenicol, oflaxacin, rifampicin, colistin, clindamycin, and vancomycin by the checkerboard titration assay. The results show that these cyclooctapeptides are fast acting bactericidals and are comparable to the related α-helical peptides in their activities. Significantly, some of these cyclooctapeptides exert selective synergistic effects in combination with the bacteriostatic tetracycline against S. aureus; a greater than 4-fold decrease in the minimum inhibition concentration was observed. Their synergism with the other evaluated antibiotics was generally partial or additive. Cationic amphipathic cyclooctapeptides in combination with some antibiotics could offer a possible solution to the increasing antimicrobial resistance predicament.
Dimeric 2G12 as a Potent Protection against HIV-1

We previously showed that broadly neutralizing anti-HIV-1 antibody 2G12 (human IgG1) naturally forms dimers that are more potent than monomeric 2G12 in in vitro neutralization of various strains of HIV-1. In this study, we have investigated the protective effects of monomeric versus dimeric 2G12 against HIV-1 infection in vivo using a humanized mouse model. Our results showed that passively transferred, purified 2G12 dimer is more potent than 2G12 monomer at preventing CD4 T cell loss and suppressing the increase of viral load following HIV-1 infection of humanized mice. Using humanized mice bearing IgG “backpack” tumors that provided 2G12 antibodies continuously, we found that a sustained dimer concentration of 5–25 µg/ml during the course of infection provides effective protection against HIV-1. Importantly, 2G12 dimer at this concentration does not favor mutations of the HIV-1 envelope that would cause the virus to completely escape 2G12 neutralization. We have therefore identified dimeric 2G12 as a potent prophylactic reagent against HIV-1 in vivo, which could be used as part of an antibody cocktail to prevent HIV-1 infection.
Morphology of stored, rejuvenated human erythrocytes.

Abstract. Whole blood was stored at 4°C for 42 days. At 7-day intervals, starting with day 21, aliquots were rejuvenated with a phosphate, inosine, glucose pyruvate, and adenine solution. Samples were taken for ATP assays and red cell morphology (by SEM) both before and after rejuvenation. Rejuvenation elevated all ATP levels in excess of 100% of the starting values and significantly increased the percent of cells in the discoid shape as measured by their morphological index, showing that rejuvenation not only raises the cell's metabolic level but causes partial reversion to fresh cell morphology.
Pulmonary hypertension in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is an untreatable diffuse parenchymal lung disease with a median survival of < 3 years. Pulmonary hypertension (PH) is frequently seen in patients with IPF and is commonly attributed to hypoxic vasoconstriction and capillary destruction. Pathology findings include endothelial proliferation and medial hypertrophy that exceed those expected in the setting of hypoxia. Noninvasive evaluation has limited sensitivity and specificity for the diagnosis of PH in IPF; therefore, right-heart catheterization remains the "gold standard" diagnostic test. PH in patients with IPF is associated with decreased exercise capacity and worse survival. Given the grave consequences of this condition, treatment of PH could improve functional outcomes and survival. However, possible treatments such as long-term supplemental oxygen and targeted vascular therapy are either unstudied or remain unproven.
The Effects of Posture on Force Estimations Using Surface Electromyography

Surface electromyography (sEMG) has shown promise in estimating grip forces while people are performing tasks; however, equipment and analysis procedures remain complex for use by practitioners in industry. The objective of this study was to quantify error in grip force estimations associated with changes in hand/wrist posture using simple methods and off-the-shelf sEMG equipment. Eight healthy, college-aged females participated in the study. Six sEMG sensors were placed radially around the forearm. Subjects applied 15%, 45%, and 75% of maximum power grip strength in seven different postures (neutral, 15, 30, and 45 degrees extension, and 15, 30, and 45 degrees flexion). sEMG signals were calibrated using linear regression and used to predict grip force. Predicted grip force was statistically compared to applied grip force measured by a digital dynamometer. The results suggest that radial electrode placement can generate reasonably accurate static force estimations regardless of MVC and across most postures, but extreme posture estimations do not appear accurate without corrections.
Comprehensive process maps to synthesize high density plasma sprayed aluminum oxide composite coatings with varying carbon nanotube content

Abstract Comprehensive process maps have been developed to synthesize “high density” plasma sprayed Aluminum oxide (Al 2 O 3 ) composite coatings with 0, 4 and 8 wt.% carbon nanotube (CNT) reinforcement. These process maps correlate the key processing parameters such as plasma power, powder feed rate, primary gas flow rate, and stand-off distance to the temperature and velocity of the in-flight particles and finally, to the porosity and microhardness of coatings. Relative importance of each significant process parameters was also investigated by making “ Pareto diagrams ”. Stand-off distance followed by the plasma power were found to be most sensitive parameters which affects the porosity of the plasma sprayed Al 2 O 3 –CNT composite coatings. Process maps showed that CNTs have a significant effect on altering the temperature and velocity of in-flight particles. Higher thermal conductivity of CNTs alters the heat transfer phenomena during the coating build up which assists in densification.
Re‐membering culture: bearing witness to the spirit of identity in research

This article examines the complexities and possibilities of identity (leaning on DuBois' notion of double consciousness) when located not in the white racial landscape of the US but in the varied racial, cultural and (inter)national contexts explicated by the scholars gathered in this issue of REE. One way to read this response might be as a critique of the limitations of DuBois' notion of double consciousness in capturing the complexities and the possibilities of identities beyond the binary of black and white, beyond nation state, ethnicities, or other racialized constructions of difference. However, more importantly, I am suggesting that our discussion of identities can also be informed by the often ignored notions of spirituality in DuBois' work, and how it might mediate our contemporary meanings of racial and other identities. Beyond wrestling with the biological and cultural explanations of identity, recognition of the spiritual nature of identity extends our ‘postcolonial’ notions beyond their over...
Light-front-quantized QCD in a covariant gauge

The light-front (LF) canonical quantization of quantum chromodynamics in covariant gauges is discussed. The Dirac procedure is used to eliminate the constraints in the gauge-fixed front form theory quantum action and to construct the LF Hamiltonian formulation. The physical degrees of freedom emerge naturally. The propagator of the dynamical ${\ensuremath{\psi}}_{+}$ part of the free fermionic propagator in the LF quantized field theory is shown to be causal and not to contain instantaneous terms. Since the relevant propagators in the covariant gauge formulation are causal, rotational invariance\char22{}including the Coulomb potential in the static limit\char22{}can be recovered, avoiding the difficulties encountered in light-cone gauge. Wick rotation may also be performed allowing the conversion of momentum space integrals into Euclidean space forms. Some explicit computations are done in quantum electrodynamics to illustrate the equivalence of front form theory with the conventional covariant formulation. LF quantization thus provides a consistent formulation of gauge theory, despite the fact that the hyperplanes ${x}^{\ifmmode\pm\else\textpm\fi{}}=0$ used to impose boundary conditions constitute characteristic surfaces of a hyperbolic partial differential equation.
Commentary on Michael Pacione´s `Urban Liveability: A Review´

(1990). Commentary on Michael Pacione's 'Urban Liveability: A Review' Urban Geography: Vol. 11, No. 1, pp. 36-41.
Evidence-Based Practice for Teaching Academics to Students With Severe Developmental Disabilities

A review of the literature was conducted for articles published between 2003 and 2010 to build a case for the degree to which evidence-based practices were documented for teaching academic skills to students with severe developmental disabilities. This review extended earlier comprehensive work in literacy, mathematics, and science for the population in question. A total of 18 studies met the Horner et al. (2005) quality indicator criteria. In general, time delay and task analytic instruction were found to be evidence-based practices. In addition, specific target responses were defined to show academic learning, with the most prevalent target responses being discrete responses; the type of systematic prompting and feedback used most often was time delay, while the component used least often was stimulus fading/shaping; and teaching formats used most often were massed trials and one-to-one instruction.
Central Dysregulation of the Hypothalamic-Pituitary-Adrenal Axis in Neuron-Specific Proopiomelanocortin-Deficient Mice

Proopiomelanocortin (POMC) is synthesized predominantly in pituitary corticotrophs, melanotrophs, and arcuate hypothalamic neurons. Corticotroph-derived ACTH mediates basal and stress-induced glucocorticoid secretion, but it is uncertain whether POMC peptides produced in the brain also regulate the hypothalamic-pituitary-adrenal axis. To address this question, we generated neuron-specific POMC-deficient mice by transgenic (Tg) replacement of pituitary POMC in a global Pomc(-/-) background. Selective restoration of pituitary POMC prevented the adrenal insufficiency and neonatal mortality characteristic of Pomc(-/-) mice. However, adult Pomc(-/-)Tg/+ mice expressing the pituitary-specific transgene exhibited adrenal cortical hypertrophy, elevated basal plasma corticosterone, elevated basal but attenuated stress-induced ACTH secretion, and inappropriately elevated CRH expression in the hypothalamic paraventricular nucleus. In addition, Pomc(-/-)Tg/+, Pomc(+/-)Tg/+, and Pomc(+/-) mice, which all displayed varying degrees of elevated CRH, frequently developed melanotroph adenomas after 1 yr of age, whereas Pomc(-/-) mice, with maximal CRH expression and glucocorticoid disinhibition, developed corticotroph and melanotroph adenomas. These results indicate that neuronal POMC peptides are necessary to regulate CRH within physiological limits and that a chronic reduction or absence of hypothalamic POMC leads to trophic stimulation of pituitary cells directly or indirectly through elevated CRH levels.
Mapping Nuclear Craters on Enewetak Atoll, Marshall Islands

In 1984, the U.S. Geological Survey conducted a detailed geologic analysis of two nuclear test craters at Enewetak Atoll, Marshall Islands, on behalf of the Defense Nuclear Agency. A multidisciplinary task force mapped the morphology, surface character, and subsurface structure of two craters, OAK and KOA. The field mapping techniques include echo sounding, sidescan sonar imaging, single-channel and multichannel seismic reflection profiling, a seismic refraction survey, and scuba and submersible operations. All operations had to be navigated precisely and correlatable with subsequent drilling and sampling operations.
Contrast agent-enhanced magnetic resonance imaging of skeletal muscle damage in animal models of muscular dystrophy.

Membrane lesions play an early role in the pathogenesis of muscular dystrophy. Using a new albumin-targeted contrast agent (MS-325), sarcolemmal integrity of two animal models for muscular dystrophy was studied by MRI. Intravenously injected MS-325 does not enter skeletal muscle of normal mice. However, mdx and Sgca-null mutant mice, animal models for Duchenne and sarcoglycan-deficient limb-girdle muscular dystrophy, respectively, showed significant accumulation of MS-325 in skeletal muscle. The results suggest that contrast agentenhanced MRI could serve as a common, noninvasive imaging procedure for evaluating the localization, extent, and mechanisms of skeletal muscle damage in muscular dystrophy. Furthermore, this method is expected to facilitate assessment of therapeutic approaches in these diseases. Magn Reson Med 44:655‐ 659, 2000. © 2000 Wiley-Liss, Inc. Accumulating data suggest that one of the initial events in the degeneration of skeletal muscle fibers in Duchenne muscular dystrophy patients is the breakdown of the sarcolemma (1‐3). It is assumed that the structural weakness of the sarcolemma and the increase in its permeability occurs when the dystrophin-glycoprotein complex (DGC) mediated linkage between the cytoskeleton and the extracellular matrix is disrupted (4 ‐ 6). One characteristic feature of muscular dystrophies arising from primary defects in the DGC is that damaged fibers accumulate in clusters (7). The formation of these clusters, which consist mainly of necrotic fibers, is not clearly understood. We and others have previously demonstrated that these clustered fibers take up membrane impermeant tracer molecules like procion orange and Evans blue dye (EBD), indicating damage to the sarcolemma (8 ‐11). Currently, detailed analysis of membrane damage in dystrophic muscle requires microscopic examination of tissues obtained from biopsies. Our objective is to study impaired membrane permeability in dystrophic skeletal muscle in vivo using noninvasive techniques. To accomplish this we have employed an albumintargeted contrast agent, MS-325 (Epix Medical, Cambridge, MA) (12‐15) to examine membrane integrity in living mice via MRI. Both the dystrophin-deficient mdx (16,17) and the recently characterized a-sarcoglycan deficient mouse (Sgcanull) (11), an animal model for limb-girdle muscular dystrophy 2D (18 ‐20), show disruption of the DGC, progressive muscular dystrophy, and profound damage of the sarcolemma (10,11). We imaged these two animal models before and after administration of MS-325 to evaluate the applicability of MRI for the in vivo assessment of muscle damage in muscular dystrophy.
Efficient balance-and-truncate model reduction for large scale systems

We present efficient implementations of the balance-and-truncate model reduction technique for large-scale systems. The key observation that distinguishes our approach is that Krylov subspace methods (Arnoldi and Lanczos) directly yield approximate low-rank square roots of the system Gramians; the balancing transformation can then be constructed from these square roots, obviating the need for solving any Lyapunov equations. In addition, the order of the reduced model is not fixed a priori as with some existing methods, but is determined from the problem data. Numerical simulations show that our approach performs very well over a range of examples, and offers considerable savings in practice.
Neopterin as a Marker of Response to Antiviral Therapy in Hepatitis C Virus Patients

Predicting the efficacy of antiviral treatment of hepatitis C virus (HCV) is of importance for both patient well-being and health care expense. The expression of interferon-stimulated genes (IFN-SGs) in the liver was suggested as a marker of response to anti-viral therapy. IFN-SGs encode the guanosine triphosphate cyclohydrolase 1 (GTPCH), a rate-limiting enzyme of pteridines biosynthesis. Neopterin, a stable byproduct of GTPCH-catalyzed reaction, is used as a marker of interferon-induced GTPCH activation. We hypothesized that assessment of neopterin concentrations might predict the response to antiviral therapy. Neopterin concentrations were evaluated in 260 HCV patients treated by pegylated interferon combined with ribavirin. Mean and median pretreatment neopterin concentrations were lower in patients with sustained virological response than in nonresponders. The rate of response was twofold higher among patients with pretreatment neopterin levels <16 nmol/L than in patients with neopterin levels ≥16 nmol/L, even after controlling for HCV genotype status. Our study suggests that the pretreatment level of neopterin might be used in routine clinical practice as rapid and cost-effective marker to predict the response to antiviral therapy in HCV patients.
Education for broadcasting: A rationale

Broadcasting could be the single, most important force on western civilization in 2000 years. Yet in some ways, southern colleges and universities have been deficient in their academic treatment of those “twentieth century phenomena—radio and television.” The continuing economic and sociological impact of these media would seem to make the immediate correction of these deficiencies an imperative.
Test Generation for Hybrid Systems Using Clustering and Learning Techniques

In this paper, we propose a test generation method that employs clustering and learning techniques to reduce test generation time in hybrid systems. While learning-oriented test generation is a well-studied problem for digital systems, there are limited efforts for utilizing learning during generation of directed tests for hybrid systems. This paper makes two important contributions: i) it develops an efficient technique to cluster a set of functional scenarios that are expected to have similar test generation trajectory, and ii) it employs efficient learning mechanism such that beneficial information is shared during test generation of similar functional scenarios in a cluster. Our experimental results using two popular hybrid systems demonstrate that our approach can significantly (up to 3:8 times, 2:9 times on average) reduce the overall test generation time.