cssi/SciSciGPT-SciSciNet huggingface dataset:
Metabolic engineering of Saccharomyces cerevisiae to produce a reduced viscosity oil from lignocellulose

Acetyl-triacylglycerols (acetyl-TAGs) are unusual triacylglycerol (TAG) molecules that contain an sn-3 acetate group. Compared to typical triacylglycerol molecules (here referred to as long chain TAGs; lcTAGs), acetyl-TAGs possess reduced viscosity and improved cold temperature properties, which may allow direct use as a drop-in diesel fuel. Their different chemical and physical properties also make acetyl-TAGs useful for other applications such as lubricants and plasticizers. Acetyl-TAGs can be synthesized by EaDAcT, a diacylglycerol acetyltransferase enzyme originally isolated from Euonymus alatus (Burning Bush). The heterologous expression of EaDAcT in different organisms, including Saccharomyces cerevisiae, resulted in the accumulation of acetyl-TAGs in storage lipids. Microbial conversion of lignocellulose into acetyl-TAGs could allow biorefinery production of versatile molecules for biofuel and bioproducts. In order to produce acetyl-TAGs from abundant lignocellulose feedstocks, we expressed EaDAcT in S. cerevisiae previously engineered to utilize xylose as a carbon source. The resulting strains were capable of producing acetyl-TAGs when grown on different media. The highest levels of acetyl-TAG production were observed with growth on synthetic lab media containing glucose or xylose. Importantly, acetyl-TAGs were also synthesized by this strain in ammonia fiber expansion (AFEX)-pretreated corn stover hydrolysate (ACSH) at higher volumetric titers than previously published strains. The deletion of the four endogenous enzymes known to contribute to lcTAG production increased the proportion of acetyl-TAGs in the total storage lipids beyond that in existing strains, which will make purification of these useful lipids easier. Surprisingly, the strains containing the four deletions were still capable of synthesizing lcTAG, suggesting that the particular strain used in this study possesses additional undetermined diacylglycerol acyltransferase activity. Additionally, the carbon source used for growth influenced the accumulation of these residual lcTAGs, with higher levels in strains cultured on xylose containing media. Our results demonstrate that S. cerevisiae can be metabolically engineered to produce acetyl-TAGs when grown on different carbon sources, including hydrolysate derived from lignocellulose. Deletion of four endogenous acyltransferases enabled a higher purity of acetyl-TAGs to be achieved, but lcTAGs were still synthesized. Longer incubation times also decreased the levels of acetyl-TAGs produced. Therefore, additional work is needed to further manipulate acetyl-TAG production in this strain of S. cerevisiae, including the identification of other TAG biosynthetic and lipolytic enzymes and a better understanding of the regulation of the synthesis and degradation of storage lipids.
Do Enhanced Compiler Error Messages Help Students?: Results Inconclusive.

One common frustration students face when first learning to program in a compiled language is the difficulty in interpreting the compiler error messages they receive. Attempts to improve error messages have produced differing results. Two recently published papers showed conflicting results, with one showing measurable change in student behavior, and the other showing no measurable change. We conducted an experiment comparable to these two over the course of several semesters in a CS1 course. This paper presents our results in the context of previous work in this area. We improved the clarity of the compiler error messages the students receive, so that they may more readily understand their mistakes and be able to make effective corrections. Our goal was to help students better understand their syntax mistakes and, as a reasonable measure of our success, we expected to document a decrease in the number of times students made consecutive submissions with the same compilation error. By doing this, we could demonstrate that this enhancement is effective. After collecting and thoroughly analyzing our own experimental data, we found that--despite anecdotal stories, student survey responses, and instructor opinions testifying to the tool's helpfulness--enhancing compiler error messages shows no measurable benefit to students. Our results validate one of the existing studies and contradict another. We discuss some of the reasons for these results and conclude with projections for future research.
Service Learning as Inquiry in an Undergraduate Science Course

To engage students in applying scientific process skills to real-world issues, we implemented a service-learning project model in our undergraduate introductory biology course for science majors. This model illustrates how we integrate inquiry inside and outside of the classroom through four steps: service, learning, classroom, and community. Out-of-class activities engaged students in serving the community (Service step) while deepening their learning experience beyond what they would learn in a classroom (Learning step). To connect the service-learning project with scientific process skills, students were asked to identify problems that our community partners were trying to solve, identify proposed solutions, and design ways to evaluate those solutions (Classroom step). Additionally, students connected their service-learning topic with core concepts in Biology. After their service, students used metrics to analyze their impact. Students then synthesized the connection between their service, learning, and classroom projects by presenting their findings to the scientific and lay communities through a poster session (Community step). Here we provide details of the model, recommendations, and examples for others to execute an inquiry-based service-learning project.
Antibiotic-mediated bacteriome depletion in ApcMin/+ mice is associated with reduction in mucus-producing goblet cells and increased colorectal cancer progression.

Recent epidemiological evidence suggests that exposure to antibiotics in early‐to‐middle adulthood is associated with an increased risk of colorectal adenoma. However, mechanistic studies in established preclinical cancer to examine these claims are extremely limited. Therefore, we investigated the effect of long‐term exposure of an antibiotic cocktail composed of Vancomycin, Neomycin, and Streptomycin, on tumor development and progression in the Apc Min/+ mouse, an established genetic model for familial adenomatous polyposis. Clinical pathologies related to tumor development as well as intestinal and colon tissue histopathology were studied at ages 8, 12, and 16 weeks of age, which correspond to the approximate ages of development of neoplasia, gut inflammation with polyposis, and cancer progression, respectively, in this animal model. We show that the antibiotics significantly increase the severity of clinical symptoms, including effects on intestinal histology and goblet cell numbers. In addition, they promote small intestinal polyposis. Finally, metagenomic analysis of fecal samples demonstrated that antibiotic exposure is associated with a significant but nonuniform depletion of the animal's natural gut flora. Overall, these findings support the premise that long‐term antibiotic exposure mediates the selected depletion of gut microbial communities and the concomitant thinning of the protective mucus layer, resulting in an increase in tumor development.
Person Perception and the Death of the Person: A New Role for Health Professionals in Cases of Brain Death

Today’s hospitals no longer contain only beds — the “staffed bed capacity” which affects the calculation of the hospital’s revenues and expenditures — for, as Professor John Lachs remarked over a decade ago, “gardens … flourish in our major hospitals…. [They contain] thousands of human vegetables we sustain on life-preserving machines without any hope of recovery” ([4], p. 839). In this New England Journal of Medicine essay, Lachs was concerned to distinguish humane treatment from the treatment of humans, and he wrote convincingly on the criteria we as a society should employ in order to justify — both morally and medically — the discontinuation of treatment for those without any hope for recovery. He defended “merciful euthanasia” and admonished his readers to reevaluate their apparently fundamental aim — “to keep this creature [the unconscious vegetable] breathing and growing to no end” ([4], p. 840). Notwithstanding the ever-present danger that physicians do at times err by making false-positive determinations of death, i.e., declaring the patient dead when, indeed, he is alive, Lachs urged that we judge such irreversibly comatose creatures as no longer human.
Experimental Distribution Circuit Voltage Regulation using DER Power Factor, Volt-Var, and Extremum Seeking Control Methods

With the rapidly increasing number of distributed energy resources (DER) on electric grids worldwide, there is a growing need to have these devices provide grid services and contribute to voltage and frequency regulation. PV inverters and other reactive-power capable DER have the capability to minimize distribution losses and provide voltage regulation with grid-support functions such as volt-var, volt-watt, and fixed power factor. The optimal settings for these functions for specific distribution topologies has been widely studied using centralized (reactive power settings) and decentralized control modes (voltvar, volt-watt). However, optimal selection of the DER operating mode and settings depends on a priori knowledge of system topology, DER sizes and locations, and renewable energy power generation or forecasts. In this paper, we experimentally evaluate an approach for optimal reactive power compensation that does not rely on the aforementioned information. Specifically, we study the ability of Extremum Seeking (ES) control-a decentralized, model-free control strategy-to minimize distribution losses and maintain voltage limits in a laboratory environment. The speed and performance of the ES control algorithm is compared to a typical smart inverter volt-var function for reactive power compensation utilizing local system measurements.
Dynamic Visualization of Quality in Online Conversations

This paper reports on software designed to visualize levels of quality within online conversational media. Prior to construction, data mining was performed on 2,157 online conversations and examined for attributes of quality. This initial dataset was analyzed for lexical complexity and prompt-specific vocabulary usage and helped guide the redesign of an existing asynchronous online discussion board (AOD). The new design incorporates a real-time quality analyzer and provides users with a visual breakdown of their post in relation to the overall group discussion thread. Results found that the proposed system produced higher levels of overall quality in discussion posts and increased interactions with higher quality discussion posts. Survey results and a social network analysis (SNA) indicate that the proposed system produced higher levels of system satisfaction and group cohesion when compared against control software.
Clinical characteristics and outcome of metaplastic breast cancer: A retrospective tertiary care center experience.

1095Background: Metaplastic breast cancer (MBC) is a rare neoplasm which accounts for less than 1% of all breast cancers. MBC is associated with worse prognosis and there is a paucity of literature...
Global interdependence in the 1980s

Mr A W Clausen, President of the World Bank, argues that the North-South concept is outdated and that international economics is far too complex for such an oversimplified model. The present international economic environment should be viewed as multipolar rather than bipolar, with at least eight discernible clusters of economic activity.
Interface-Resolved Simulations of Reactor Flows

This critical review paper outlines the recent progress in high-resolution numerical simulations of two-phase coolant flow in light water reactor–relevant geometries by resolving the water-vapor in...
Effects of nitroethane and 2-nitropropanol against Campylobacter jejuni

Campylobacter jejuni is an important foodborne pathogen that colonizes the gut of swine. In this study, the effects of nitroethane and 2-nitropropanol (0, 10 and 20 mM) on growth of C. jejuni were tested during culture in Bolton broth adjusted to pH of 5.6, 7.0 or 8.2. Viable cell counts of samples taken at intervals during incubation revealed main effects (P 1.8 and >5.4 log10 CFU/ml after 48 h incubation with 20 mM nitroethane or 2-nitropropanol, respectively. A marked effect of pH on the inhibitory activity of both com- pounds was observed, with greater activity observed at higher pH.
Induction of the Fetal Scarless Phenotype in Adult Wounds: Impossible?

Adult cutaneous wounds repair through a fibroproliferative response which results in a scar. Early-gestation fetal skin has the ability to regenerate damaged skin without the formation of a scar in a process that resembles regeneration. The fetal and adult wound healing phenotypes are characterized by differences in the degree of inflammation, molecular signaling, extracellular matrix composition, and biomechanical properties. Significant advancements in understanding scarless fetal mammalian wound healing have led to the development of therapeutic applications with the potential to reduce scarring in the healing of adult cutaneous wounds. This chapter outlines the molecular and cellular processes involved in scarless fetal wound healing and the progress that has been made in recapitulating this process in adult wounds.
1965 Evolution of phenotypic plasticity in plants

Abstract Plants share the inability to move when their local environment changes in a substantial way. Bradshaw (1965) spelled out the many circumstances under which phenotypic plasticity might evolve in plant populations as a way of coping with environmental fluctuations.
The Role of Methodological Choices in the Effects of Experimental Exposure to Simulated Natural Landscapes on Human Health and Cognitive Performance: A Systematic Review:

We review the methods and findings of experiments that have examined the effects of exposure to simulated natural landscapes on human health and cognitive performance. Keyword searches of PubMed, S...
Quantum teleportation for keyless cryptography

This paper looks at using quantum teleportation for secure message exchange. Although the proposed protocol has parallels with Ekert’s protocol for key distribution, we look at the issue of directly teleporting message bits instead of encryption keys. Further, it is the first protocol of it’s type where the role of the sender and receiver are flipped around. In other words, unlike traditional protocols, in the proposed protocol the receiver first performs certain measurements thus implicitly determining a stream of bits that she combines with the bit stream received from the sender to determine the secret message. There are no qubits wasted in random measurements.
Monte Carlo Studies of Surface-Induced Ordering in Cu3Au-Type Alloy Models

Using Monte Carlo simulations we study order-disorder phenomena near the surface to compare with experimental results for CU3AU alloys. Our simulations reveal possible new ordering cases near the surface which could lead to surface induced ordering.
Numerical calculation of the particle–fluid–particle stress in random arrays of fixed particles

The phase interaction force in a multiphase flow is decomposed into a particle-mean field force and a divergence of a Particle-Fluid-Particle (PFP) stress. The particle mean field force is mainly accounted for through drag models, while the PFP stress arising from the interparticle interactions is seldom reported. Using the nearest particle statistics, the PFP stress is calculated from particle-resolved simulations. The PFP stress represents the macroscopic effect of the drafting-kissing-tumbling mechanism.
Closed-loop identification and tuning for damping of interarea modes

An iterative closed-loop identification method is applied to obtain linear models of a power system for use in controller design. Two different probing levels are used for model identification to demonstrate both the underlying nonlinear nature of the power system and the effectiveness of using the closed-loop iterative identification method in the case of large probing inputs. The identified plant models contain non-minimum phase zeros, and controllers are designed using linear quadratic Gaussian theory with partial loop transfer recovery (LQG/LTR). Simulation results are presented to illustrate the robustness of the resulting controller to changes in operating point. >
Design of a Parallel Robot with a Large Workspace for the Functional Evaluation of Aircraft Dynamics beyond the Nominal Flight Envelope

This paper summarizes the development of a robotic system for the analysis of aircraft dynamics within and beyond the nominal flight envelope. The paper proposes the development of a parallel robot...
A reduction in uterine perfusion pressure induces hypertension during pregnancy in the mouse (1084.5)

Preeclampsia is a hypertensive disorder of pregnancy and a leading cause of maternal morbidity and mortality; however, the underlying mechanisms are not clear. Reduced uterine perfusion in the pregnant rat induces many of the characteristics of preeclampsia including hypertension and fetal growth restriction. However, the lack of availability of a mouse model prevents harnessing the power of genetically modified mice. Thus, the aim of this study was to develop a mouse model of reduced uterine perfusion pressure (RUPP). Pregnant C57BL/6J mice were subjected to either a sham surgery or a mechanical reduction of the blood flow to the abdominal aorta and both branches of ovarian arteries initiated at day 13 of gestation (E13). Mice were instrumented with a carotid arterial catheter at E17 followed by measurement of mean arterial pressure (MAP) at E18 in the conscious state. MAP at E18 in the RUPP was significantly elevated versus sham (117±4 vs. 97±2 mmHg, P<0.01; respectively). Pup weight from the RUPP were ...
“Co-Flare” Stimulation in the Poor Responder Patient: Predictive Value of the Flare Response

Methods: This study was conducted at a university based IVF Center. A total of 564 patient cycles over a 2.5-year time frame in patients that had either elevated FSH levels or a previous poor response to conventional leuprolide acetate downregulated stimulation were retrospectively analyzed. These patients were treated with our co-flare protocol (1.0 mg of leuprolide acetate administered on day 2 and decreased on day 5 to 0.5 mg; gonadotropins initiated on day 3). We analyzed the initial flare response and the outcome for these patients. Results: A total of 564 patients attempted to initiate an IVF cycle. The patients mean age was 39.4§ 3.7 years. Of the 450 cycles that started, the outcomes were as follows: 24% (108/450) cancellation, 20.4% (92/450) clinical pregnancy per initiated cycle, and a 14.0% delivery rate per initiated cycle. Patients with an estradiol flare that doubled were less likely to have cycles cancelled (13.6% vs. 35.6%, P< 0.01), but no differences were noted in pregnancy outcome if the cycle was not cancelled once the patient made it to retrieval. Conclusions: We have demonstrated an overall 14.0% delivery rate per initiated cycle in these “poor prognosis” patients. While the initial flare response (as indicated by a doubling of the estradiol by the second day of stimulation) was indicative
In Vivo Delivery of a Bcl-xL Fusion Protein Containing the TAT Protein Transduction Domain Protects against Ischemic Brain Injury and Neuronal Apoptosis

Bcl-xL is a well characterized death-suppressing molecule of the Bcl-2 family. Bcl-xL is expressed in embryonic and adult neurons of the CNS and may play a critical role in preventing neuronal apoptosis that occurs during brain development or results from diverse pathologic stimuli, including cerebral ischemia. In this study, we used a novel approach to study the potential neuroprotective effect of Bcl-xL as a therapeutic agent in the murine model of focal ischemia/reperfusion. We created a Bcl-xL fusion protein, designated as PTD-HA-Bcl-xL, which contains the protein transduction domain (PTD) derived from the human immunodeficiency TAT protein. We demonstrated that this fusion protein is highly efficient in transducing into primary neurons in cultures and potently inhibited staurosporin-induced neuronal apoptosis. Furthermore, intraperitoneal injection of PTD-HA-Bcl-xL into mice resulted in robust protein transduction in neurons in various brain regions within 1–2 hr, and decreased cerebral infarction (up to ∼40%) in a dose-dependent manner, as determined at 3 d after 90 min of focal ischemia. PTD-HA-Bcl-xL was effective even when it was administered after the completion of ischemia (up to 45 min), and the protective effect was independent of the changes in cerebral blood flow or other physiological parameters. Finally, as shown by immunohistochemistry, Western blotting, and substrate–cleavage assays, PTD-HA-Bcl-xL attenuated ischemia-induced caspase-3 activation in ischemic neurons. These results thus confirm the neuroprotective effect of Bcl-xL against ischemic brain injury and provide the first evidence that the PTD can be used to efficiently transduce a biologically active neuroprotectant in experimental cerebral ischemia.
Price Discovery in Stock and Option Markets: A Portfolio Approach

In this paper, we propose a new portfolio approach to estimate Hasbrouck's (1995) information share (IS), which measures the relative contribution of one market to the variance of an efficient stock return process. Using GMM, we are able to estimate optimal weights for a portfolio of options to be used in Hasbrouck's (1995) analysis. With our dataset, IS of the option market using only ATM call options lies between 31% and 46%, while IS using a portfolio of options lies between 47% and 58%, a statistically significant increase. This finding indicates that using only one type of options, as often done in the literature, may result in an underestimated measure. We also find that as we increase the resolution of the data from 30 seconds to 15 minutes, the weight of OTM options in a portfolio increases from 18% to 32%. This result shows that the OTM option market's information takes time to be incorporated into stock prices since the information travels across stock and option markets.
The Theoretical Basis of the Kinetic Method from the Point of View of Finite Heat Bath Theory

We present a rigorous theoretical basis of the kinetic method, commonly used for thermochemical determinations in mass spectrometry, based on finite heat bath theory (FHBT) developed by Klots. A simple analytical expression for the branching ratio is derived from FHBT formalism. This expression simplifies to the expression given by the absolute reaction rate theory (1) for very large clusters or (2) for reactions having a negligible kinetic shift. The reacting population is described by two different temperatures rather than by the “effective” temperature as suggested previously. Simulations performed using both RRKM and FHBT revealed that the kinetic plots are slightly nonlinear. The observed curvature is related to the changes in the transition state temperature as a function of the critical energy for fragmentation. The curvature of the plots decreases for larger clusters. We show that the “effective” temperature closely resembles the average value of the transition state temperature. This allows us to...
EXPLAINING THE ACADEMIC PERFORMANCE‐DELINQUENCY RELATIONSHIP*

We use data from the National Education Longitudinal Survey to examine the relationship between academic performance and delinquency. We estimate the effects of grades in tenth grade on delinquency in twelfth grade, and then introduce controls for social bonds and self-control (teacher-rated effort). The findings indicate that the feedback that adolescents receive in the form of grades does not affect their delinquent behavior, that academic performance and delinquency have instead a spurious relationship. Our evidence suggests that this relationship is attributable primarily to the effects of individual differences in self-control, not to those of social bonds.
Comparison of longitudinal in vivo measurements of retinal nerve fiber layer thickness and retinal ganglion cell density after optic nerve transection in rat.

Purpose To determine the relationship between longitudinal in vivo measurements of retinal nerve fiber layer thickness (RNFLT) and retinal ganglion cell (RGC) density after unilateral optic nerve transection (ONT).
The Drosophila U2 snRNP protein U2A' has an essential function that is SNF/U2B" independent.

Recruitment of the U2 snRNP to the pre-mRNA is an essential step in spliceosome assembly. Although the protein components of the U2 snRNP have been identified, their individual contributions to function are poorly defined. In vitro studies with the Drosophila and human proteins suggest that two of the U2 snRNP-specific proteins, U2A′ and U2B″, function exclusively as a dimer. In Drosophila the presence of the U2B″ counterpart, Sans-Fille (SNF), in the U2 snRNP is dispensable for viability, suggesting that SNF is not necessary for U2 snRNP function in vivo. With the identification of a single U2A′-like protein in the Drosophila genome, we can now investigate the relationship between SNF and its putative binding partner in vivo. Here we show that Drosophila U2A′ protein interacts with SNF in vivo and, like its human counterpart, is U2 snRNP specific. Unexpectedly, however, we find that loss of function causes lethality, suggesting that U2A′, but not SNF, is critical for U2 snRNP function. Moreover, although we demonstrate that several domains in the SNF protein are important for the interaction with the Drosophila U2A′ protein, including a redundant domain at the normally dispensable C-terminus, we find that U2A′ does not require heterodimer formation for either its vital function or U2 snRNP assembly. Thus together these data demonstrate that in Drosophila U2A′ has an essential function that is unrelated to its role as the partner protein of SNF/U2B″.
Oxidative Stress, Bone Marrow Failure, and Genome Instability in Hematopoietic Stem Cells

Reactive oxygen species (ROS) can be generated by defective endogenous reduction of oxygen by cellular enzymes or in the mitochondrial respiratory pathway, as well as by exogenous exposure to UV or environmental damaging agents. Regulation of intracellular ROS levels is critical since increases above normal concentrations lead to oxidative stress and DNA damage. A growing body of evidence indicates that the inability to regulate high levels of ROS leading to alteration of cellular homeostasis or defective repair of ROS-induced damage lies at the root of diseases characterized by both neurodegeneration and bone marrow failure as well as cancer. That these diseases may be reflective of the dynamic ability of cells to respond to ROS through developmental stages and aging lies in the similarities between phenotypes at the cellular level. This review summarizes work linking the ability to regulate intracellular ROS to the hematopoietic stem cell phenotype, aging, and disease.
Significance of Aggregation of Fine Sediment Particles in Their Deposition

Abstract The significance of aggregation processes, by which the properties of suspended fine sediment particles or flocs change during transport, is examined for the simple case of deposition of estuarine sediments in a flume. A multi-class model for aggregation processes is combined with a one-dimensional, unsteady, multi-class sediment transport model to calculate the deposition rate for two flume experiments—one with no recirculation of a medium-cohesion sediment, and the other in which a high-cohesion sediment was recirculated by pumping. The results show that while aggregation processes had a moderate effect on the rate of deposition of medium-cohesion sediment, they dominated high-cohesion sediment deposition. The results also suggest that multi-class fine sediment aggregation-plus-deposition calculations will produce more realistic results than single-class calculations in estuaries where sediment exhibits a high degree of cohesion and variability in flow-induced shearing.
Development of Bacterial Display Peptides for use in Biosensing Applications

Recent advances in synthetic library engineering continue to show promise for the rapid production of reagent technology in response to biological threats. A synthetic library of peptide mutants built off a bacterial host offers a convenient means to link the peptide sequence, (i.e., identity of individual library members) with the desired molecular recognition traits, but also allows for a relatively simple protocol, amenable to automation. An improved understanding of the mechanisms of recognition and control of synthetic reagent isolation and evolution remain critical to success. In this paper, we describe our approach to development of peptide affinity reagents based on peptide bacterial display technology with improved control of binding interactions for stringent evolution of reagent candidates, and tailored performance capabilities. There are four key elements to the peptide affinity reagent program including: (1) the diverse bacterial library technology, (2) advanced reagent screening amenable to laboratory automation and control, (3) iterative characterization and feedback on both affinity and specificity of the molecular interactions, and (3) integrated multiscale computational prescreening of candidate peptide ligands including in silico prediction of improved binding performance. Specific results on peptides binders to Protective Antigen (PA) protein of Bacillus anthracis and Staphylococcal Enterotoxin B (SEB) will be presented. Recent highlights of on cell vs. off-cell affinity behavior and correlation of the results with advanced docking simulations on the protein-peptide system(s) are included. The potential of this technology and approach to enable rapid development of a new affinity reagent with unprecedented speed (less than one week) would allow for rapid response to new and constantly emerging threats.
Existence of Compressible Bilayers in the Functionalized Cahn--Hilliard Equation

The functionalized Cahn--Hilliard (FCH) free energy models phase separation in amphiphilic systems, which possess a component with both hydrophilic and hydrophobic tendencies. We establish the existence of a family of bilayer structures, described by homoclinic solutions of a fourth-order dynamical system arising from the FCH energy in the nongeneric case of an equal-depth double well, $W\geq0$. The free parameter accommodates bilayers of variable width, which correspond to the compression of the bilayer under external pressure. Modulo a nondegeneracy condition, which we conjecture is associated to an orbit-flip bifurcation within the fourth-order dynamical system, we show that its homoclinic orbits are well approximated by those of a corresponding second-order dynamical system obtained by perturbing the potential well $W$ with the primitive of Modica and Mortola's $\sqrt{W}$.
Advances in laser cooling of semiconductors

Laser cooling in semiconductor structures due to anti-Stokes luminescence is reviewed. Theoretical background considering luminescence trapping and red-shifting, the effect of free carrier and back-ground absorption, Pauli band-blocking, and the temperature-dependence of various recombination mechanisms are discussed. Recent experimental results demonstrating record external quantum efficiencies (EQE) in GaAs/GaInP heterostructures are described, and conditions favorable for the first observation of laser cooling in semiconductors are discussed.
Regulation, politics, and interest groups: What do we learn from an historical approach?

Abstract In The Regulated Economy: A Historical Approach to Political Economy, Claudia Goldin and Gary D. Libecap use case studies to defend and expand upon the notion that elements of civil society—“special interests”—manage to “capture” government regulators and make the state serve their selfish ends. The evidence of the case studies themselves, however, and the occurrence of such anomalies as the deregulatory movement, suggest that government actors often enjoy considerable autonomy in regulating civil society, and that readily manipulable currents in public opinion are also important.
Alendronate stimulates collagenase 3 expression in osteoblasts by posttranscriptional mechanisms.

Bisphosphonates inhibit bone resorption by reducing osteoclastic cell number and activity. Alendronate is a nitrogen-containing bisphosphonate analog used in the treatment of postmenopausal osteoporosis. The effects of alendronate in osteoclasts are well documented; however, there is limited information on the actions of alendronate in osteoblasts (Ob's). In this study, we investigated the effects of alendronate at concentrations of 1-100 μM on the synthesis of collagenase 3 or matrix metalloproteinase 13 (MMP-13) and tissue inhibitors of MMPs (TIMPs) 1, 2, and 3 in primary Ob-enriched cells from 22-day-old fetal rat calvariae. Alendronate at concentrations higher than 10 μM markedly stimulated the synthesis of collagenase messenger RNA (mRNA) and immunoreactive protein in Ob's. Alendronate did not stimulate the transcriptional rate of the collagenase 3 gene. However, in transcriptionally arrested cells, alendronate prolonged the half-life of collagenase transcripts. Alendronate did not alter the expression of TIMP 1 and 2, but modestly stimulated the expression of TIMP 3. The actions of alendronate in Ob's suggest potential additional effects in bone remodeling.
Slowly rotating drops

We study the existence of gyrostatic equilibria of slowly rotating liquid masses subject only to the force of surface tension. We give a rigorous proof of the existence of non-axisymmetric equilibria. The shape of such an equilibrium approximates a number of spherical lobes connected by thin necks and symmetrically arranged around the axis of rotation.
Cell membrane localization of sterols with conventional and unusual side chains in two marine demonsponges

Subcellular fractionation by differential centrifugation was performed on two previously unstudied marine sponges that predominantly contain either conventional (Reniera sp.) or unconventional (Pseudaxinyssa sp.) sterols. Direct evidence for the presence of unconventional sterols with C24 alkylated side chains in the cellular membranes ofPseudaxinyssa sp. is provided, but the presence of unconventional sterols in sponge membranes is shown not to be a universal feature of the Porifera. Possible structural and functional roles of unconventional lipid molecules in sponge cell membranes are discussed.
Conformation of N4-acetylcytidine, a modified nucleoside of tRNA, and stereochemistry of codon-anticodon interaction

Abstract The crystal structure of N 4 -acetylcytidine (ac 4 C) a modified nucleoside of tRNA, has been determined from three-dimensional x-ray diffractometer data. The N 4 -substituent is proximal to C(5), quite contrary to expectations from solution studies of N 4 -methylcytosine. This orientation of the N 4 -substituent will not block Watson-Crick base pairing for reading the third codon by tRNA M Met , and hence the discriminatory function suggested for ac 4 C might arise due to non-standard conformation of the polynucleotide backbone of the anticodon around the Wobble base. A common characteristic of the modified nucleosides that occur at the Wobble position is their inability to shield the Watson-Crick base pairing sites; this is quite consistent with the necessity for reading the third base of the codon. This is in sharp contrast to the modifications of the nucleosides adjacent to the 3′-end of anticodons, all of which prevent Watson-Crick base pairing.
519 SPARC (SURVIVAL PREDICTION AFTER RADICAL CYSTECTOMY): A MULTIFACTORIAL OUTCOME PREDICTION MODEL FOR PATIENTS UNDERGOING RADICAL CYSTECTOMY FOR BLADDER CANCER

INTRODUCTION AND OBJECTIVES: While multiple independent clinicopathologic variables associated with outcome following radical cystectomy (RC) for bladder cancer (BC) have been identified, limited prediction tools exist to facilitate an individualized risk assessment based on the relative weight of these various features. Herein, we developed an outcome prediction model based on clinical and pathologic characteristics found to be significantly associated with death from BC after RC. METHODS: We evaluated 1829 patients who underwent RC without neoadjuvant therapy at our institution between 1980–2008. Of these, 1,751 with non-metastatic, non-small cell histology were identified. Univariate analysis evaluating variables associated with BC specific mortality was conducted. A multivariate model was obtained using a stepwise selection process from variables significant at the 0.05 level. A scoring system based on the -coefficients of this model was created, assigning 1 point for each parameter estimate value of 0.20. RESULTS: Median follow-up after RC was 10.7 years (interquartile range 7.7, 15.7), during which time 652 patients experienced death due to BC. On multivariate analysis (Table), race, Charlson comorbidity index, ECOG status, current smoking status, preoperative hydronephrosis, pathologic stage, multifocality, lymphovascular invasion, and concurrent CIS were significantly associated with BC death. Cumulative scores from these variables were used to stratify patients into quintiles according to risk score of BC death as 4, 5-8, 9-12, 13-16, and 17. 5-year cancer specific survival (CSS) from the lowest to highest risk quintile was 95%, 82%, 58%, 35%, and 17%, respectively (p 0.0001). The c-index for this model was 0.76. CONCLUSIONS: We present a model for individualizing estimation of CSS following radical cystectomy. Pending external validation, these data may be used for patient counseling, specifically with regard to recommendations for adjuvant therapy and surveillance frequency, as well as in clinical trial development.
Magnetic anisotropy and crystalline electric field effects in RRh4B4 single crystals

Research on polycrystalline RRh4B4 samples has shown that crystalline electric field (CEF) effects play an important role in these compounds. The successful synthesis of single crystal samples of RRh4B4 with R = Y, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu has provided an opportunity to further investigate CEF effects in these materials. Magnetization and magnetic susceptibility measurements on the RRh4B4 single crystals revealed strong magnetic anisotropy, and the experimental results could be described well by CEF calculations based on the parameters derived from an analysis of experimental data for ErRh4B4 single crystals. The easy directions of magnetization of these compounds are consistent with the signs of the Stevens factor αJ of the CEF Hamiltonian. A strong influence of magnetic anisotropy on superconductivity was also observed.
Aging and health: a longitudinal study

A set of double jeopardy hypotheses predicting there is a double health disadvantage in growing old and being a member of an ethnic minority, female, of lower socioeconomic status, and unmarried is tested with data from a 4-yr longitudinal study of older Mexican Americans and Anglos. With the exception of socioeconomic status, little support is found for the double jeopardy predictions in a multivariate analysis of change in health. When subjects who died during the study interval were included in the analysis by assigning them the lowest score on health, the results changed somewhat: the relationship between age and decline in health was strengthened and the effect of sex changed from a direction suggesting that women show greater declines in health with age to a direction suggesting that men experience greater declines in health with age. Implications of the effect of decreased dropouts for studies on aging and health are discussed.
On the structure and composition of carbon nitride

The role of the nonbonded NN repulsions of the recently proposed “β-C3N4” structure is considered. The importance of these repulsions raises questions about the composition of carbon nitride samples so far prepared, with the suggestion that nitrogen content of crystalline particles in such preparations is substantially below the 57% limit implied by the β-C3N4 formulation. A modification of the proposed structure is offered in which nitrogen centers subject to the greatest crowding in β-C3N4 are replaced by CC bonded dimers.
Complexation Studies of Water-soluble Calixarenes and Auramine O Dye

Abstract The dye, Auramine O, whose fluorescence is sensitive to its microenvironment, is used to study the complexation properties of the host molecules, calix[6]arene sulfonates. Complexation between the dye and the sulfonated calixarenes has been characterized by use of absorption and steady state fluorescence measurements. A comparison study of the calixarenes and the monomers suggests that the observed shifts of the absorption and the fluorescence of Auramine O are due to complex formation. In addition, the fluorescence of Auramine O is enhanced as a result of its association with calixarenes. Fluorescence intensities in the absence and presence of calixarenes are employed to calculate formation constants of the inclusion complexes. The stoichiometric ratio for both SCX6/AuO and SCX6-C5H11/AuO is 1:1. The formation constants for these complexes are estimated to be 1.24 × 104 M−1 and 1.53 × 104 M−1, respectively.
Electrophysiological findings and long-term follow-up of patients with the permanent form of junctional reciprocating tachycardia treated by catheter ablation.

BACKGROUND The permanent form of junctional reciprocating tachycardia (PJRT) commonly presents as recurrent drug-refractory, narrow-complex tachycardia. We studied the efficacy and safety of catheter ablation in treating these patients. METHODS AND RESULTS Six patients with the diagnosis of PJRT were treated at our institution with direct-current catheter ablation. The study cohort comprised three men and three women with a mean age of 33.8 +/- 4.5 years. The mean time from onset of symptoms to ablation was 129 +/- 44.7 months. All failed multiple drug therapy (mean number of drugs failed was 5.3 +/- 0.5). The left ventricular ejection fractions were calculated by echocardiography and were greater than 60% in all except two patients, whose ejection fractions were 25% and 32%. Symptom duration was significantly longer in those with depressed ejection fraction compared with normal patients (258 versus 64.5 months, p less than 0.01). Electrophysiological findings revealed evidence of an atrioventricular reciprocating tachycardia involving retrograde decremental conduction over an accessory pathway localized to the posteroseptal area. Five patients received two direct-current shocks (250 +/- 16.7 J per shock) via paired electrodes from a catheter positioned just outside the coronary sinus os to a patch placed between the scapulae or on the anterior chest wall. One patient received a single direct-current shock of 300 J. The only complication was the development of complete atrioventricular block in one patient. This patient had previously undergone permanent pacemaker insertion for the sick sinus syndrome. The mean hospital stay after ablation was 2.2 days. Mean peak creatinine phosphokinase after ablation was 352 +/- 58.1 units/l and the MB fraction was 12 +/- 2%. Follow-up echocardiograms or gated nuclear studies showed improvement of ejection fraction in the two patients who presented with depressed ejection fractions. After a mean follow-up of 35.8 +/- 10.3 months, all patients remained free of tachycardia without antiarrhythmic drugs. CONCLUSIONS We conclude that catheter ablation by using direct current energy appears to be an effective treatment in patients with PJRT.
Temperature-mediated processes in teleost immunity: the effects of temperature on membrane immunoglobulin capping on channel catfish B lymphocytes.

Abstract 1. 1. In order to better understand ligand-induced redistribution of membrane receptors and lymphocyte activation in ectothermie vertebrates, flow cytometry was used to monitor the effects of both in vivo acclimation temperature and in vitro assay temperatures on the kinetics of monoclonal antibody-induced membrane immunoglobulin (mIg) capping on channel catfish lymphocytes. 2. 2. It was observed that the kinetics of mIg capping were dependent on in vitro assay temperatures, in vivo acclimation temperatures, and the length of time of in vivo acclimation. In the latter situation in vivo acclimation offish to 27, 22 and 17°C was considered complete after 3 weeks, while acclimation to 12°C required a minimum of 5 weeks. 3. 3. The energies of activation required for mig capping ranged from 33 to 24kcal/mol; lower energies of activation were observed with lower temperature acclimation. 4. 4. It was also noted that the lower energies of activation were associated with concomitant decreases in cellular phospholipid saturated/unsaturated fatty acid ratios. 5. 5. It appears that channel catfish B cell mig capping, presumably a requisite for immune function, can be significantly affected by environmental temperatures; most likely such effects are attributable to changes in plasma membrane viscosities.
Paradoxical regulation of human argininosuccinate synthetase cDNA minigene in opposition to endogenous gene: evidence for intragenic control sequences.

Human somatic cell variants resistant to the arginine analog, canavanine, express 200-fold increased levels of argininosuccinate synthetase (AS) mRNA as compared to parental cells. In this study we examined whether AS cDNA sequences contain cis-acting regulatory elements that are involved in the induction of AS mRNA in canavanine-resistant cells. Minigene constructs containing AS cDNA sequences under the transcriptional control of a viral promoter were stably transfected into the human squamous cell carcinoma line, RPMI 2650. Upon conversion of cells to canavanine-resistance, expression of the endogenous ASgene increased by two orders of magnitude as expected. Surprisingly, however, expression of AS cDNA minigenes decreased 10- to 15- fold in canavanine-resistant cell variants. The observed down-modulation of AS cDNA minigene expression was dependent upon a concomitant induction of the endogenous ASgene and not simply expression of the canavanine-resistant phenotype. This paradoxical regulation was specific for ASgene sequences since a minigene containing the neomycin-resistance gene in place of AS cDNA sequences failed to regulate. Furthermore, minigenes lacking a substantial portion of the AS cDNA also failed to exhibit the down-modulation. These findings suggest that expression of the human ASgene is regulated by a specific and limiting, positively-acting, trans-acting mechanism in canavanine-resistant cells and that exogenous AS cDNA (mRNA) sequences can compete for this mechanism.
The interaction of drug- and psychotherapy in the long-term treatment of depression

Recent advances in our understanding of both short- and long-term therapeutic interventions for depressive disorders have necessitated greater precision in defining appropriate therapeutic interventions. While these remarkable changes in treatment have been based on the introduction of newer antidepressant agents, the advances have occurred because of more systematic clinical trials and a greater sophistication in defining diagnostic and treatment response criteria. This paper reviews key findings in recurrent depression with respect to long-term treatment. Particular attention is paid to the combination treatment of psychotherapy and antidepressant drugs.