cssi/SciSciGPT-SciSciNet huggingface dataset:
Endocytic delivery of vancomycin mediated by a synthetic cell surface receptor: rescue of bacterially infected Mammalian cells and tissue targeting in vivo.

Extracellular domains of internalizing cell surface receptors are often targeted to enable drug delivery through the mechanism of receptor-mediated endocytosis. To circumvent natural receptors required for endocytic drug delivery, we constructed a small artificial cell surface receptor comprising the membrane anchor N-alkyl-3β-cholesterylamine linked to a d-Phe-d-Ala motif that binds the glycopeptide antibiotic vancomycin. By mimicking membrane association and trafficking properties of cholesterol, this cholesterol-derived synthetic receptor functions as a prosthetic molecule, inserting into plasma membranes of mammalian cells, and rapidly cycling between the cell surface and intracellular endosomes. Human HeLa cells treated with this receptor gained the ability to internalize vancomycin by endocytosis, enabling this cell-impermeable antibiotic to eradicate the lethal intracellular pathogen Listeria monocytogenes and preserving the viability of the host cells in vitro. Moreover, when combined with the syn...
System controls for a resistive ribbon printer

The system controls for a printer using the resistive ribbon print technology involve conventional requirements, such as moving the print mechanism relative to the paper, with a new requirement, controlling the electrical energy to the ribbon, an electrothermal component. Other special requirements are dictated by using the same ribbon for hard copy print/erase while ensuring that the print and erase operations are acceptable to the user. This paper discusses the design and performance of the system controls for a resistive ribbon printer that was developed for use in an interactive typewriter application and as an output printer for a personal computer.
Grazing effects on nitrogen fixation in coral reef algal turfs

This study addressed whether grazing by the sea urchin Diadema antillarum influenced rates of nitrogen fixation by algal turf communities on Caribbean coral reefs. Because the turfs were nitrogen-limited, we also assessed whether newly-fixed nitrogen was important for supporting net primary productivity by the turfs. We measured acetylene reduction in turfs grown in treatments excluding or including D. antillarum in the presence of other herbivores at 3 m water depth on Tague Bay forereef, St. Croix, U.S. Virgin Islands. These were the first measurements of acetylene reduction on coral reefs under quasi-natural conditions of high water-flow and photosynthetic oxygen generation. Rates of acetylene reduction under these conditions were as high as any measured previously in coral reef communities (mean 7.6 nmol C2H4 cm−2 h−1). Algal turfs grazed by D. antillarum and other herbivores had chlorophyll-specific acetylene reduction rates up to three times higher than when D. antillarum was excluded. High rates of nitrogen fixation by the turfs were sufficient to meet <2% of the nitrogen required to support net chlorophyll-specific primary productivity over 24 h. Grazer-mediated increases in nitrogen fixation do not appear responsible for a parallel enhancement of net primary productivity. Algal turfs at this site must be dependent primarily on external sources of nitrogen.
Identification and characterization of an activated 20S proteasome in Trypanosoma brucei

Recently, we have reported the isolation and purification of 20S proteasomes from both the procyclic and bloodstream forms of Trypanosoma brucei, but no 26S proteasome was identified under those experimental conditions (Hua et al., Mol. Biochem. Parasitol. (1996) 78, 33-46). Subsequent attempts to identify a 26S proteasome in T. brucei led to the discovery of another form of the 20S proteasome designated the activated 20S proteasome because it exhibited much higher peptidase activities than the original 20S proteasome on all the fluorogenic peptides tested, and it crossreacted with the rabbit antisera against the 20S proteasomes purified from T. brucei. The activated 20S proteasome can be isolated from both procyclic and bloodstream forms of T. brucei and has a slightly higher molecular weight than the 20S proteasome. It is stable in the absence of ATP but susceptible to elution through a DE52 column. Analysis of the activated 20S proteasome in SDS-PAGE showed the presence of all the subunit proteins from the 20S proteasome plus an extra protein with an estimated molecular mass of 26 kDa. This protein, designated PA26, is not a degradation product of the 20S proteasomal subunit proteins. It could be a homolog of the bovine PA28 and human 11S regulator protein which form complexes with the 20S proteasomes resulting in activation of their peptidase activities. This likelihood was confirmed in a reconstitution experiment in which PA26 separated from the proteasome by a DE52 column chromatography was re-introduced into the purified 20S proteasome, and resulted in the emergence of a new protein band with the same mobility and peptidase activities as the activated 20S proteasome in native polyacrylamide gel electrophoresis. The presence of an activated 20S proteasome rather than a homolog of the 26S proteasome in T. brucei suggests that PA26 may play an important role in regulating the proteasome-mediated protein degradations in trypanosomes.
The Kinetics and Mechanism of the Thermal Dehydrochlorination of Poly(vinyl Chloride)

Abstract Poly(vinyl chloride) degrades thermally by an acceleratory reaction in which the rate of hydrogen chloride evolution is slow at the beginning, increases with time (passing through a maximum), and then decreases. A kinetic model based on the zipper mechanism shows excellent agreement with observed data from the initial to the final stages of each dehydrochlorination. Hydrogen chloride is shown to be essential for the initiation of zip chains and may or may not be essential for the zip reaction. When hydrogen chloride is removed in a stream of inert gas, as it is in some tests purported to study the kinetics of degradation, the initiation of zip chains is significantly inhibited. The zip reaction, once it has been initiated, is not inhibited or stopped even by long exposure to atmospheric conditions.
Role of the thyroid gland in urinary pentose excretion in the rat.

SummaryIt has been observed in rats that thyroid feeding markedly increases the urinary excretion of pentose, and thiouracil feeding greatly reduces the output of urinary pentose. Animals on a diet containing thiouracil also survive poorly in the cold. These observations offer strong evidence for the assumption that in the rat the thyroid gland has a dominating role in the production of urinary pentose and that adjustment of animals to cold takes place, at least in part, through activity of the thyroid gland.
Hermetic joining of 316L stainless steel using a patterned nickel nanoparticle interlayer

Abstract This paper evaluates the use of a nickel nanoparticle (NiNP) interlayer for making hermetic joints in 316L stainless steel substrates via diffusion brazing. Different NiNP inks were prepared using commercial nanopowder (∼9 nm) and in-house synthesized nanoparticles. Syringe pump deposition of ∼9 nm NiNP ink and diffusion brazing at 900 °C for 30 min under 2 MPa resulted in a hermetic joint up to the tested pressure of 70 psi. In-house synthesis of NiNPs was carried out in ethylene glycol by the reduction of NiCl2·6H2O in the presence of hydrazine (N2H4) as a reducing agent. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) results confirm the presence of pure fcc-Ni with an average particle size of 5.4 ± 0.9 nm. An as-synthesized suspension of NiNPs was patterned onto 316L stainless steel laminae via automated dispensing to a thickness of ∼3 μm and bonded at 800 °C for 30 min at a pressure of 2 MPa. The diffusion-brazed test article was also found to be hermetic up to 70 psi. An examination of the bond line using scanning electron microscopy (SEM) showed good uniformity and continuity.
A simple preparation of β-trypsin based on a calorimetric study of the thermal stabilities of α- and β-trypsin

Abstract Bovine trypsin preparations contain, in addition to the single chain form of the enzyme, an active two-chain autolysis product (Schroeder, D. D., and Shaw, E., J. Biol. Chem. (1968), 243 , 2943–2949). Differential scanning calorimetric (DSC) studies showed that the single chain form, β-trypsin, is more stable to thermal denaturation than the two-chain form, α-trypsin. Rate constants and activation energies for the thermal denaturation of β-trypsin are 5 × 10 −5 sec −1 and 69 kcal/mole and of α-trypsin are 5 × 10 −3 sec −1 and 38 kcal/mole at pH 4.4 and 48 °C. Preparation of pure β-trypsin can be greatly simplified by prior thermal denaturation of the α form. At least 75% of the α form is denatured by heating a 10–15% solution of commercial crystalline trypsin for 30–45 min at 48 °C, pH 4.4, 0.02 m Ca 2+ . The native β-trypsin is then easily isolated from the denatured α-trypsin by batchwise adsorption onto ovoinhibitor-agarose at pH 8. After elution at pH 2, dialysis, and lyophilization an average preparation contained approximately 85% β-trypsin, 10% α-trypsin, and 5% inactive material. Benzamidine was used during the isolation to decrease the rate of conversion of β- to α-trypsin. Because the separation of active β-trypsin from heat-denatured α-trypsin is relatively easy, the total preparation time has been reduced to 1 day.
Advanced Scanning Electron Microscopy and X Ray Microanalysis

This text is the third in a group that evolved from a short course taught annually at Lehigh University, Bethlehem, Pa., since 1972. Chapters on magnetic contrast a nd electron channeling, dropped from the second volume for reasons of space, are included here along with new topics such as image processing. The first seven chapters should be oT value to those geologists interested in scanning electron microscopy (SEM) and microanalysis. Chapters 8 and 9, concerned with specimen preparation for biological SEM a nd cryomicroscopy, make up about one third of the text.
A practical approach to transferring linear gradient elution methods

Attempts to theoretically address the problems involved in transferring linear gradient elution methods have been somewhat ad hoc due to the simplifying assumptions usually made in conventional gradient elution theory. Until now, all equations based on the k* parameter of linear gradient elution theory used as the basis for predicting the separation selectivity have not explicitly included the effect of the dwell volume (VD). Using an exact equation for predicting k*, that is, one which fully accounts in an a priori fashion for VD, we find a set of simple yet exact equations which unequivocally must be satisfied to transfer an optimized linear gradient elution method from one system (column or instrument or both) to another. These relationships absolutely mandate that a change in the instrument dwell volume requires a proportional change in the column volume; in turn, a change in the column volume requires a proportional change in the flow rate and/or gradient time to maintain a constant gradient steepness. Although we are not the first to suggest these guidelines, this work provides a complete theoretical foundation for these exact guidelines for the maintenance of gradient selectivity for the case of transferring a linear gradient elution method between different columns packed with the same particles and/or between different instruments.
The reaction of the isoenzymes of transaldolase with chlorodinitrobenzene.

Abstract The two primary isoenzymes of transaldolase are inactivated on exposure to low concentrations (2 m m ) of chlorodinitrobenzene at pH 9.0. At 23 ° the two isoenzymes show remarkably different rates of inactivation and only one, isoenzyme III, is inactivated at a significant rate. Above 30 ° both enzymes are inactivated. The Arrhenius activation energies for this process have been estimated as 105,000 cal/mole for isoenzyme I and 49,800 cal/mole for isoenzyme III. In each case complete loss of activity was observed when all four cysteine residues were dinitrophenylated. Substrate was found to protect against both inactivation and dinitrophenylation. The protection by substrate appears to be due to conformational changes which render the sulfhydryl groups less accessible to the reagent.
Raman study of phonons in Ga1−xAlxAs

Detailed Raman measurements were performed on the optical phonons in the disordered alloy Ga1−xAlxAs at room temperature. The results obtained are compared with earlier measurements and expressions are given for the Al concentration dependence of the AlAs-like and GaAs-like longitudinal and transverse optical modes. Copyright © 2002 John Wiley & Sons, Ltd.
Sameness: an experiment in code search

To date, most dedicated code search engines use ranking algorithms that focus only on the relevancy between the query and the results. In practice, this means that a developer may receive search results that are all drawn from the same project, all implement the same algorithm using the same external library, or all exhibit the same complexity or size, among other possibilities that are less than ideal. In this paper, we propose that code search engines should also locate both diverse and concise (brief but complete) sets of code results. We present four novel algorithms that use relevance, diversity, and conciseness in ranking code search results. To evaluate these algorithms and the value of diversity and conciseness in code search, twenty-one professional programmers were asked to compare pairs of top ten results produced by competing algorithms. We found that two of our new algorithms produce top ten results that are strongly preferred by the programmers.
Point vortex model of the unsteady separated flow past a semi-infinite plate with transverse motion

Two-dimensional unsteady separated flow past a semi-infinite plate with transverse motion is considered. The rolling-up of the separated shear-layer is modelled by a point vortex whose time-dependent circulation is predicted by an unsteady Kutta condition. A power-law starting flow is assumed along with a power law for the transverse motion. The effects of the motion of the plate on the starting vortex circulation and trajectory are presented. A suitable vortex shedding mechanism is introduced and a class of flows involving several vortices is presented. Finally, some possibilities for actively controlling the production of circulation by moving the plate are discussed.
Estrogen-induced Protection of Heart Ischemia-reperfusion Injury by the Inhibition of the Mitochondrial Permeability Transition Pore (mPTP) in Isolated Heart Mouse

Although several studies have shown that the administration of 17s-estradiol (E2) has a cardioprotective effect during ischemia-reperfusion (I/R), the mechanisms of this action are largely unknown. In this study, we investigated the effects of E2 on the opening of mPTP and as well on the myocardial infarct size after global myocardial I/R injury. Hearts of male mice were isolated and retrograde-perfused through aorta with the Langerdoff system at 37 oC. After 20 min of perfusion, hearts were subjected to 20min global ischemia followed by 40min reperfusion. Mitochondria were isolated to measure Calcium Resistance Capacity (CRC) and mPTP installation; infarct size was evaluated by triphenyltetrazolium chloride staining (TTC). Experiments were performed in hearts perfused with Krebs Henseleit solution or with Krebs Henseleit + E2 (100 pg/ml, corresponding to E2 peak concentration at proestrus). The E2-treated group had increased CRC (0.73+0.11 μM vs. 1.2+ 0.06, p < 0.01) and a reduced infarct size (43 ± 3% vs. 68 ± 5%, p < 0.01) compared to the control group. The E2-induced infarct size reduction was abolished by the specific estrogen receptor antagonist ICI 182,780 (100 nM). These results indicate that a brief E2 exposure favors CRC by inhibiting the mPTP installation resulting in a reduction of the infarct size. We propose these actions as a mechanism for E2-induced protection during I/R in isolated hearts.
Dynamic lipid changes in rapidly proliferating hepatic smooth endoplasmic reticulum during acute dexamethasone treatment of adrenalectomized rats.

The regulation by the cell of subcellular membrane components is dependent on a highly complex balance of nutritional, hormonal and metabolic events. We have characterized the lipid components of the endoplasmic reticulum (ER) of the liver of adrenalectomized (ADX) rats and the response of these membrane components to glucocorticoid administration. Membrane microviscosity as measured by fluorescence depolarization of 1,6-diphenylhexatriene (DPH) was measured and correlated with lipid composition and content of the membranes. In the ADX rat, a significant increase in membrane microviscosity of the smooth endoplasmic reticulum (SER) was observed and this was accompanied by an increase in the cholesterol content/mg protein and a decrease in the phospholipid content/mg protein. A change in the fatty acyl chain composition is observed with a significant increase in the mole percentage of arachidonic acid (20∶4) and an accompanying decrease in saturated fatty acids. Within 2–6 hr of dexamethasone administration, a decrease in membrane microviscosity is observed that returns this value to one similar to that for normal control animals. Both the cholesterol and the phospholipid contents/mg protein are likewise restored to levels similar to that for control animals beginning at the 2-hr time point. The arachidonic acid and saturated fatty acid content of the constituent phospholipids do not begin to return to values similar to those for control animals until 6 hr after dexamethasone administration. From these experiments, we can conclude that glucocorticoids play a significant regulatory role in determining the lipid properties of rat hepatic microsomal membranes.
The demand for rental housing: An investigation of some demographic and economic determinants

One of the most basic distinctions made in housing market analysis is that betweeh the market for rental uhits ahd the market for owner units. The resulting eategeries are ind~ed quite geheral, yet alknowledge of the factors that determine the relative size of these markets is considered essential for understh~ding housing market behavior. It might be argued that the two way classification is entirely too vague -that the liberal financing programs offered today have erased the lines between owning and renting. Further dissent might note that the large number of oneunit buildings in the rental market obseu1"es differentiation f~om the owner market, l But, as this study will show, a definite distinction can be made. More specifically, the probability tha~ a household will own or r6nt at a particular point in time can be quite accurately assessed when a few basic characteristics of that household are known. Despite this finding, it will be argued that the simple termre split serves to hide important dynamic elements of housing demand. The objectives of this study are first, to quantitatively evaluate the influence of a few basic household characteristics (specifically household income, size, an~ age-of-head) on tenure choice, and second, to forecast the percentage of households that rent based upon expected change in these household character is t ics . The study was prompted by the fact that a rather dramatic change in the age structure of households is expected to take place by 1975. Although it has been observed in the past that the future shift favoring young households should strengthen rental demand, th6 quantitativ e impact has A not been estimated. 2 The effect on rental demand of the household character is t ics being considered, here, are best analyzed on a cross-sec t ional basis , so it is assumed that the empir ical ly determined relationships are stable over the forecasting period. Naturally, since only a l imited number of variables are included, the forecasts are made on the assumption that all other factors remain constant. several important variables, such as relat ive cost and financing, were unavoidaI~ly neglecte}t, because the necessary data were unavailable.
REPRODUCTIVE BIOLOGY OF WEEDY AND CULTIVATED MIRABILIS (NYCTAGINACEAE)

The reproductive biology of Mirabilis nyctaginea (Michx.) MacM. contributes to the plant's success as a weed and invader of disturbed habitats whereas that of M. Jalapa L. reflects its success as a cultivar. Plants of M. nyctaginea flowering in early summer produce chasmogamous flowers whereas plants flowering in late summer produce cleistogamous flowers. Plants of both species are self-compatible and flower behavior contributes to self-pollination. The flowers open late in the afternoon and close late the following morning. In M. nyctaginea flowers are effectively pollinated by bees both in the afternoon and morning, and during the night moths are effective pollinators. Mirabilis Jalapa is self-pollinating. Anther closure during rain showers, a result of water droplets falling into open anthers, minimizes pollen loss and is highly adaptive. The reproductive biology of M. nyctaginea and M. Jalapa is contrasted with that of the obligate outcrossing species M. multiflora (Torr.) Gray and M. froebelii (Behr) Greene. THE EVOLUTION of weedy and cultivated plants from obligate outcrossing ancestors is often paralleled by significant changes in the breeding systems of those plants (Baker, 1965, 1967; Rick, 1950; Hutchinson, 1965; Cruden, unpublished). Such changes include a decrease in flower size, decrease in the pollen-ovule (P/0) ratio, switching from self-incompatible to self-compatible, and changing from cross-pollinating to self-pollinating. Within Mirabilis (Nyctaginaceae) are included a weedy species, M. nyctaginea (Michx.) MacMill.; a cultivar, M. Jalapa L.; and numerous native selfincompatible, obligate outcrossing species, e.g., M. multiflora (Torr.) Gray and M. froebelii (Behr) Greene. Differences in floral behavior and reproductive biology in Mirabilis illustrate some of the changes that occur during the evolution of either a weed or a cultivar. In this paper I describe the reproductive biology of M. nyctaginea, comment on the floral behavior of M. Jalapa, suggest that pollination need not result in fertilization, and compare the reproductive biology of these species with those of M. multiflora and M. froebelii.
Molecular Imaging: Love It or Lose It

Because most medical imaging disciplines are part of radiology and molecular imaging appears to be important for the survival of radiology, radiologists, along with their colleagues in nuclear medicine, should be involved in the development of the discipline and its scientific advancement.
FULL DEPTH PRECAST AND PRECAST, PRESTRESSED CONCRETE BRIDGE DECK PANELS

Since 1970, there has been a dramatic increase in the use of full depth precast and precast, prestressed concrete deck panels for the rehabilitation and new construction of bridges. In order to document the various applications of bridge deck panels in North America, a questionnaire survey was sent to the departments of transportation (DOTs) of individual states and one province. Requested information in the survey included type of construction, deck dimensions, deck supporting system, panel dimensions and reinforcement, type of connecting system between panels and supporting system, type of joint between the adjacent panels, type of bonding material used to fill the joints, problems associated with the joints, reasons for adverse results, and type of protection system. The returned questionnaires were compiled and analyzed. This paper summarizes the significant results of this survey
Band gap opening in methane intercalated graphene

Recent experimental work has demonstrated production of quasi-free-standing graphene by methane intercalation. The intercalation weakens the coupling of adjacent graphene layers and yields Dirac fermion behaviour of monolayer graphene. We have investigated the electronic characteristics of a methane intercepted graphene bilayer under a perpendicularly applied electric field. Evolution of the band structure of intercalated graphene as a function of the bias is studied by means of density-functional theory including interlayer van der Waals interactions. The implications of controllable band gap opening in methane-intercalated graphene for future device applications are discussed.
Breaking the Phonon Bottleneck in PbSe and CdSe Quantum Dots: Time-Domain Density Functional Theory of Charge Carrier Relaxation

Spatial confinement can create relaxation bottlenecks by mismatch between electronic and vibrational frequencies. This hypothesis motivated discovery of multiple excitons, which could greatly enhance the efficiency of quantum dot (QD) solar cells. Surprisingly, recent experiments showed no bottleneck. Our time-domain ab initio study of the electron−phonon dynamics rationalizes the fast relaxation in PbSe and CdSe QDs, which have substantially different electronic properties. Atom fluctuations and surface effects lift degeneracies and create dense distributions of electronic levels at all but the lowest energies, while confinement enhances the electron−phonon coupling. The analysis applies to nanomaterials in general, modifying the fundamental view on the electron−phonon interaction.
Analysis of nine food additives in red wine by ion-suppression reversed-phase high-performance liquid chromatography using trifluoroacetic acid and ammonium acetate as ion-suppressors

A reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the simultaneous determination of nine food additives, i.e., acesulfame, saccharin, caffeine, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid and neotame in red wine. The effects of ion-suppressors, i.e., trifluoroacetic acid (TFA) and ammonium acetate (AmAc) on retention behavior of nine food additives in RP-HPLC separation were discussed in detail. The relationships between retention factors of solutes and volume percent of ion-suppressors in the mobile-phase systems of acetonitrile-TFA aqueous solution and acetonitrile-TFA-AmAc aqueous solution were quantitatively established, respectively. The results showed that the ion suppressors had not only an ion suppression effect, but also an organic modification effect on the acidic analytes. The baseline separation of nine food additives was completed by a gradient elution with acetonitrile-TFA(0.01%, v/v)-AmAc(2.5 mmol L(-1)) aqueous solution as the mobile phase. The recoveries were between 80.2 - 99.5% for all analytes with RSDs in the range of 1.5 - 8.9%. The linearities were in the range of 0.2 - 100.0 mg L(-1) with determination coefficients (r(2)) higher than 0.9991 for all analytes. The limits of quantification (LOQs) were between 0.53 - 0.99 mg L(-1). The applicability of the proposed method to detect and quantify food additives has been demonstrated in the analysis of 30 real samples.
The Presence of a Calling and Academic Satisfaction: Examining Potential Mediators.

Abstract The present study examined the relation of calling and academic satisfaction with a diverse sample of 312 undergraduate students. The presence of a calling was moderately correlated with academic satisfaction, and a multiple mediation model was utilized to test three potential mediators to this relation: career decision self-efficacy, work hope, and meaning in life. Using bootstrapping techniques, significant indirect effects were found for two of the three mediators, career decision self-efficacy, and work hope. After including the mediators in the model, the relation of calling and academic satisfaction was non-significant. These results indicate that calling relates to greater satisfaction in the academic domain in part because of increased career decision self-efficacy and work hope. Directions for future research are discussed.
The Forgotten Genre of Children's Poetry.

The author argues that 20th-century children's poetry is often ignored and that the emphasis on teaching the adult poetry canon can give children mistaken ideas about what poetry is. Poetry is not a collection of “classics” whose meanings must be explained but something written to capture thoughts, feelings, and experiences. Ideas for teaching poetry are included.
Clinical utility of CT angiography in DIEP breast reconstruction

Summary Background CT angiography has become the gold-standard imaging modality prior to DIEP flap breast reconstructions. Recent studies show excellent correlation between CTA and operative perforator location, but not their clinical significance. This study seeks to specifically evaluate the clinical utility of CTA in DIEP free flaps. Methods Preoperative CT angiography of the deep inferior epigastric system was obtained in 52 sequential DIEP free flaps involving 37 patients with dominant perforators marked by radiologist. Planned and used perforators were documented by the surgeon before and after the operation. Results A total of 62 out of 76 planned perforators were ultimately used (82%). Of those not used, 71% were abandoned due to inadequacy of preoperative CT. An additional 38 perforators were used that were not part of the initial preoperative plan, 60% of which were added due to inadequacy of the preoperative CT for planning. In total 23/52 flaps (44%) involved intraoperative changes due to features not appreciated on preoperative CT. Conclusion CTA mapping of perforators prior to DIEP flap surgery increases surgeon confidence and reduces operative time; however, there are still a significant number of changes made based on clinical judgment. This study highlights the importance of surgeon review of CTA images. Caution is warranted in reliance on CTA mapping, and significant perforators should not be sacrificed until the anticipated perforator(s) have been exposed and evaluated. Level of evidence Level 3.
The effect of extended post-discharge chemical thromboprophylaxis on venous thromboembolism rates after bariatric surgery: a prospective comparison trial.

The effect of extended post-discharge thromboprophylaxis (ETP) on venous thromboembolism (VTE) rates following bariatric surgery (BS) is unknown. 308 consecutive patients who underwent BS between 2003 and 2007 and who had >1 month of follow-up were included. In-hospital-only VTE prophylaxis (group A), or extended 10-day ETP (group B) was used in 132 and 176 patients, respectively. All patients underwent bilateral lower extremity venous Doppler studies (BLEVDS) prior to discharge. Primary endpoint was the incidence of VTE within 30 days postoperatively. VTE was defined as a clinically evident deep vein thrombosis or pulmonary embolism documented by positive BLEVDS, or computed chest tomography. The primary safety endpoint was bleeding associated with ≥2 g/dL decrease in hemoglobin compared with baseline, transfusion or reoperation. The incidence of VTE was 1.9% (6/308); 66.6% (4/6) of cases occurred after cessation of thromboprophylaxis. There were no deaths in either group. With the exception of percentage open surgical approach (A: 3% versus B: 0%, p = 0.03), percentage conversions (A: 0 versus B: 3.8%, p = 0.01), and hospital stay (A: 3 versus B: 2.2 days, p < 0.0001), the two groups were comparable in relation to age, sex, body mass index, percentage revision surgery, operative time, and history of VTE. VTE rate was significantly higher in group A (A: 4.5% versus B: 0%, p = 0.006). Although morbidity was higher in group A (A: 12.1% versus B: 1.1%, p < 0.0001), no VTE event occurred in patients who had other complications. The incidence of significant bleeding was lower in group B (A: 5.3% versus B: 0.56%, p = 0.02). ETP is safe and effective in reducing the incidence of VTE as compared with in-hospital thromboprophylaxis only.
The Operon: On Its Third Anniversary

The 22 October issue presents the wildly improbable coincidence of containing both a letter about parapsychology and "spontaneous cases" (p. 436) and a "spontaneous case." For on page 463, as part of my comments on the 1965 Nobel Laureates in Medicine or Physiology, there appears the phrase "The operator ‘loses’. . .," though what I had actually written was "The operator ‘closes’...." Now since I happen to have some doubts about the validity of the operator concept, doubts that I certainly would not consciously have wished to introduce on this happy occasion [though I did voice them earlier in Science 144, 816 (1964)], this strange error can be explained only as a Freudian slip by a member of the editorial staff of Science acting under the telekinetic influence of an author9s psyche.
Equivalent primal and dual differentiable reformulations of the Euclidean multifacility location problem

In this paper, we consider two equivalent differentiable reformulations of the nondifferentiable Euclidean multifacility location problem (EMFLP). The first of these is derived via a Lagrangian dual approach based on the optimum of a linear function over a unit ball (circle). The resulting formulation turns out to be identical to the known dual problem proposed by Francis and Cabot [1]. Hence, besides providing an easy direct derivation of the dual problem, this approach lends insights into its connections with classical Lagrangian duality and related results. In particular, it characterizes a straightforward recovery of primal location decisions. The second equivalent differentiable formulation is constructed directly in the primal space. Although the individual constraints of the resulting problem are generally nonconvex, we show that their intersection represents a convex feasible region. We then establish the relationship between the Karush–Kuhn–Tucker (KKT) conditions for this problem and the necessary and sufficient optimality conditions for EMFLP. This lends insights into the possible performance of standard differentiable nonlinear programming algorithms when applied to solve this reformulated problem. Some computational results on test problems from the literature, and other randomly generated problems, are also provided.
Structures of Staphylococcus aureus Cell-Wall Complexes with Vancomycin, Eremomycin, and Chloroeremomycin Derivatives by 13C{19F} and 15N{19F} Rotational-Echo Double Resonance

Solid-state NMR has been used to examine isolated cell walls and intact whole cells of Staphylococcus aureus complexed to five different vancomycin, eremomycin, and chloroeremomycin derivatives. The cell walls and whole cells were specifically labeled with d-[1-13C]alanine, or a combination of [1-13C]glycine and [e-15N]lysine. Each of the bound glycopeptides had a 19F-labeled substituent at either its C-terminus or its disaccharide position. The 13C{19F} rotational-echo double-resonance (REDOR) dephasing for the cell-wall 13C-labeled bridging pentaglycyl segment connecting a glycopeptide-complexed peptidoglycan stem with its neighboring stem indicates that the fluorine labels for all bound glycopeptides are positioned at one or the other end of the bridge. An exception is N‘-(p-trifluoromethoxybenzyl)chloroeremomycin, whose hydrophobic substituent differs in length by one phenyl group compared to that of oritavancin, N‘-4-[(4-chlorophenyl)benzyl)]chloroeremomycin. For this drug, the fluorine label is near...
"Major stewards of storytelling": pre-service librarians' perspectives on librarians' roles in 21st century storytelling

This poster presents an ongoing, exploratory study of pre-service librarians' perspectives on storytelling in libraries. Storytelling is a frequent program offering in public and school libraries, and a background in storytelling equips librarians with skills that will enrich their work with library patrons of all ages. As such, Storytelling is offered as an elective course for library and information science (LIS) graduate students. In this study, students who were enrolled in a graduate-level LIS course on storytelling were invited to contribute their electronic discussion board assignments from the course to a research study conducted by the course instructor. Along with focus group responses, the discussion board posts were analyzed to (1) explore students' perspectives on storytelling in 21st century libraries and their roles in storytelling as future librarians and (2) to inform instruction of storytelling in LIS graduate programs. Initial findings show that students identify a need to maintain storytelling traditions with careful incorporation of 21st century technologies.
Genetical processes in the Galapagos

Current understanding of the mode and tempo of evolutionary divergence within the major groups of terrestrial vertebrates of the Galapagos Archipelago is summarized from three perspectives: (I ) the number and relative timing of introductions for each group; (2) the influence of historical factors and present-day population demography of patterns and amounts of genetic diversity; and (3) possible mechanisms of adaptive radiation, or macroevolution, within the tortoise and finch groups. Native and introduced rats, lava lizards, geckos, and iguanas most likely had more than one episode of introduction from already differentiated mainland stocks. The finches and tortoises appear to have originated from but a single respective radiation. The influence of these differences in invasion histories is clearly evident in patterns of within-island genetic biochemical diversity and between-island or hetween-species differentiation. It is argued that much of the pattern of withinspecies geographic differentiation in genetic characters results from the temporal history of populations, including the amount of migration between islands, as well as differential selection pressures. Major morphological differentiation within both the finch and tortoise radiations has occurred with minimal change at structural gene loci. Studies of, for example, developmental heterochrony and character heritability analyses are needed to understand this apparent paradox.
Immunotherapy with ligands of natural killer T cells

Natural killer T (NKT) cells are innate lymphocytes that share receptor structures and functions with conventional T cells and natural killer cells. NKT cells are specific for glycolipid antigens bound by the major histocompatibility complex class I-like protein CD1d. One striking property of NKT cells is their capacity to rapidly produce large amounts of cytokines in response to T-cell receptor engagement, suggesting that activated NKT cells can modulate adaptive immune responses. Recent pre-clinical studies have revealed significant efficacy of NKT-cell ligands such as the glycolipid α-galactosylceramide for treatment of metastatic cancers and infections, and for prevention of autoimmune diseases. These findings suggest that appropriate stimulation of NKT cells could be exploited for prevention or treatment of human diseases.
Underachieving Gifted Males: Are We Missing the Boat?.

Discussion of underachieves often overlooks gifted high school males achieving well, but not near the academic levels of which they are capable. An even larger problem is their lack of social skill which prevents them from participating in those high school activities which prepare young people for leadership roles later in life. Adolescence, a time of great change, demands that effective coping mechanisms be well developed before the additional stresses of high school. Adults need to recognize the importance of social skill development and actively encourage advanced young males to become involved in both academic and social growth activities. Underachievement by high school students has been a topic of concern for some time, but most of this concern has been directed toward extreme underachievers who receive low or failing grades, drop out of school, or even commit suicide (Farrell, 1989; Rimm, 1989). Underachievement is often overlooked in male students who achieve at good levels but are capable of ach...
Obesity intervention in persons with spinal cord injury

A single group uncontrolled trial. Despite widespread emphasis on the obesity-related health risks in persons with spinal cord injury (SCI), limited research has been carried out to intervene in this problem. This study was conducted to assess the initial effectiveness of a weight loss program on various health outcomes in persons with SCI. A rehabilitation center in Birmingham, Alabama, United States. A total of 16 individuals with chronic SCI who were overweight or obese participated in a weight management program that consisted of 12 weekly classes, covering nutrition, exercise, and behavior modification. Various outcomes were examined over a 6-month period (baseline, week 12, and week 24), including body composition measured by dual energy X-ray absorptiometry, physiologic measures, diet behavior, and psychosocial and physical functioning. Of these, 13 participants returned for the week 24 follow-up. Weight loss averaged 3.5±3.1 kg (3.8% of the initial weight) at week 12 and 2.9±3.7 kg (3.0% of the initial weight) at week 24. There was a significant reduction from baseline values at weeks 12 and 24 in body mass index, anthropometric measurements, and fat mass and improvement in diet behavior and psychosocial and physical functioning, while lean mass and blood albumin and hemoglobin levels were maintained. A correlation analysis showed that a greater weight loss was importantly (r>0.4) associated with a greater reduction in total cholesterol at weeks 12 and 24 and in systolic and diastolic blood pressure at week 24. Several factors were important (r>0.4 or r<−0.4) in determining the success in weight loss, including age, race, marital and employment status, family history of overweight/obesity, level and duration of injury, and cholesterol level at baseline. This is the first demonstration that a carefully planned program with time–calorie displacement diet is effective for overweight/obese individuals with SCI to lose weight without compromising total lean mass and overall health. It provides foundation for a future large clinical trial for weight loss of persons with SCI or other spinal cord dysfunction. National Institute on Disability and Rehabilitation Research (Grant # H133B30025) and National Institutes of Health (Grant # M01 RR00032), United States.
A Simple Gauss-Newton Procedure for Covariance Structure Analysis with High-Level Computer Languages.

An implementation of the Gauss-Newton algorithm for the analysis of covariance structures that is specifically adapted for high-level computer languages is reviewed. With this procedure one need only describe the structural form of the population covariance matrix, and provide a sample covariance matrix and initial values for the parameters. The gradient and approximate Hessian, which vary from model to model, are computed numerically. Using this approach, the entire method can be operationalized in a comparatively small program. A large class of models can be estimated, including many that utilize functional relationships among the parameters that are not possible in most available computer programs. Some examples are provided to illustrate how the algorithm can be used.
Nuclear-Magnetic-Resonance Spectra of Ureas in Aqueous Solution

There is considerable confusion in the literature concerning the nuclear-magnetic-resonance spectra of ureas in aqueous solution. Redpath and Smith report that the spectrum of N,N'-dimethylurea exhibits a broad signal for the protons on nitrogen and an unsymmetrical doublet for the methyl groups. This doublet collapses to a singlet in acid solutions and is attributed to spin–spin coupling of the methyl protons with the [Equation] moiety, rather than to any type of hindered rotation. Under similar conditions, Birchall and Gillespie report no observable coupling between the CH3− and =N–H groups of N,N'-dimethylurea, even in the absence of acid. This lack of spin–spin coupling is attributed to rapid proton exchange between the urea nitrogens and the solvent. They report no observable signal due to the =N–H moiety. However, the =N–H signal was found by them in the spectrum of urea itself under similar conditions.
A system of processes related by cause and effect Part II. A generalized complex variable

This paper establishes the mathematical foundations for the cause and effect relations of Part I. This is done by developing a theory of functions of a generalized complex variable
Microclimate, air mixing and physiological regulation of transpiration as influenced by wind shelter in an irrigated bean field☆

Abstract This paper reports the results of a study made to determine the nature of microclimatic changes induced by a wind barrier and the nature of dry bean response to the induced microclimate in an irrigated field in western Nebraska. The study was conducted during the growing seasons of 1962 and 1963. Shelter sharply reduced wind movement over the canopy of the plants. A new diurnal pattern of air and soil temperature and of vapor-pressure was generated in the shelter. The plants responded by larger size and higher yield during both years and in greater leaf area during the first season. Evaporation in the shelter was reduced but the plants remained more turgid throughout the daylight hours and resisted stomatal closure allowing greater transpiration and consequently more rapid withdrawal of soil moisture. Data are presented which show that CO2 supply need not be limited in the shelter because of reduced wind passage over the plant and that greater potential photosynthesis in the shelter consequent upon the more open condition of the stomates can be realized.
RXTE observations of PKS 2155-304 during the November 1997 gamma-ray outburst

Abstract We present X-ray observations of the nearby BL Lac PKS 2155-304 taken when it was undergoing a GeV/TeV gamma-ray outburst. During the outburst we measured X-ray fluxes in the 2–10 keV band that are the largest ever observed for PKS 2155-304. Comparison of these November 1997 measurements and other X-ray observations made contemporaneously with GeV or TeV gamma-ray observations indicate that X-ray and gamma-ray emissions are correlated. Measurements with X-ray all-sky monitors such as the ASM/RXTE and MOXE can therefore signal the presence of outbursts at gamma-ray energies from PKS 2155-304.