cssi/SciSciGPT-SciSciNet huggingface dataset:
Impaired Therapeutic Capacity of Autologous Stem Cells in a Model of Type 2 Diabetes

Endogenous stem cells in the bone marrow respond to environmental cues and contribute to tissue maintenance and repair. In type 2 diabetes, a multifaceted metabolic disease characterized by insulin resistance and hyperglycemia, major complications are seen in multiple organ systems. To evaluate the effects of this disease on the endogenous stem cell population, we used a type 2 diabetic mouse model (db/db), which recapitulates these diabetic phenotypes. Bone marrow-derived mesenchymal stem cells (MSCs) from db/db mice were characterized in vitro using flow cytometric cell population analysis, differentiation, gene expression, and proliferation assays. Diabetic MSCs were evaluated for their therapeutic potential in vivo using an excisional splint wound model in both nondiabetic wild-type and diabetic mice. Diabetic animals possessed fewer MSCs, which were proliferation and survival impaired in vitro. Examination of the recruitment response of stem and progenitor cells after wounding revealed that significantly fewer endogenous MSCs homed to the site of injury in diabetic subjects. Although direct engraftment of healthy MSCs accelerated wound closure in both healthy and diabetic subjects, diabetic MSC engraftment produced limited improvement in the diabetic subjects and could not produce the same therapeutic outcomes as in their nondiabetic counterparts in vivo. Our data reveal stem cell impairment as a major complication of type 2 diabetes in mice and suggest that the disease may stably alter endogenous MSCs. These results have implications for the efficiency of autologous therapies in diabetic patients and identify endogenous MSCs as a potential therapeutic target.
Allosteric Intermediates in Hemoglobin. 1. Nanosecond Time-Resolved Circular Dichroism Spectroscopy†

Time-resolved circular dichroism (TRCD) studies performed on photolyzed hemoglobin-CO complex (HbCO) probe room temperature protein relaxations in Hb, including the R --> T allosteric transition. TRCD spectroscopy of photolysis intermediates in the near-UV (250-400 nm) spectral region provides a diagnostic for T-like structure at the alpha 1 beta 2 interface via the effect of quaternary structure on the UV CD of aromatic residues. The TRCD of porphyrin-based transitions in the UV and Soret regions, reflecting transition-dipole couplings between hemes and aromatic residues over a radius wide enough to permit heme-interface and inter-dimer interactions, is modulated by the tertiary and quaternary structure of photolysis intermediates. In the allosteric core model of Hb cooperativity, Fe-CO bond breakage initiates a heme structural change, thought to be heme doming, that is transmitted to the alpha 1 beta 2 interface via the F helix. The TRCD results, analyzed in light of kinetic information from time-resolved absorption studies, suggest specific features for the mechanism by which the ensuing tertiary and quaternary conformational changes propagate through the protein. In particular, the UV-TRCD indicates that the alpha 1 beta 2 interface responds within several hundred nanoseconds to initial events at the heme by shifting from an R toward a T-like interface. The appearance of T-like character at the alpha 1 beta 2 interface tens of microseconds before the appearance of equilibrated T state deoxyHb indicates that the R --> T transition in photolyzed HbCO is a stepwise process, as previously suggested by time-resolved resonance Raman studies.
Notch Signaling in Blood Vessels: Who Is Talking to Whom About What?

It has become increasingly clear that the Notch signaling pathway plays a critical role in the development and homeostasis of the cardiovascular system. This notion has emerged from loss- and gain-of-function analysis and from the realization that several hereditary cardiovascular disorders originate from gene mutations that have a direct impact on Notch signaling. Current research efforts are focused on determining the specific cellular and molecular effects of Notch signaling. The rationale for this has stemmed from the clinical importance and therapeutic potential of modulating vascular formation during various disease states. A more complete appreciation of Notch signaling, as it relates to vascular morphogenesis, requires an in-depth knowledge of expression patterns of the various signaling components and a comprehensive understanding of downstream targets. The goal of this review is to summarize current knowledge regarding Notch signaling during vascular development and within the adult vascular wall. Our focus is on the genetic analysis and cellular experiments that have been performed with Notch ligands, receptors, and downstream targets. We also highlight questions and controversies regarding the contribution of this pathway to vascular development.
Clonidine reverses the amnesia induced by dopamine beta hydroxylase inhibition.

Abstract The role of noradrenergic (NE) me mechanisms in amnesia induced by the dopamine-β-hydroxylase (DBH) inhibitor, diethyldithiocarbamate (DEDTC) was examined by studying the antiamnestic characteristics of the alpha-NE receptor stimulator clonidine. DEDTC (250 mg/kg) administered 3 hr prior to training to C57BL/6J mice resulted in marked deficits when retention of a multiple trial food motivated spatial discrimination task was measured 24 hr after learning. Investigation of the temporal aspects of recovery indicated that the agonist was an effective antiamnestic agent when administered 0, 1, 3, 21 and 23 hr after training. No recovery was observed when the drug was administered 6 and 18 hr posttraining. A dose response study of the effectiveness of clonidine administered 1 hr prior to testing indicated recovery of memory at doses ranging from 10–500 μg/kg. The clonidine induced recovery was not a result of general performance facilitation, but specific to the memory tested. In addition, the clonidine effect was pharmacologically specific to its actions on NE receptors, as recovery was blocked by pre-treatment with the alpha-NE antagonist, phentolamine. No recovery from DEDTC induced amnesia was seen with post-training or pre-test injection of d-amphetamine.
p21waf1/cip1 deficiency does not perturb the intestinal crypt stem cell population after massive small bowel resection

Abstract Background After small bowel resection (SBR), adaptation is initiated in intestinal crypts where stem cells reside. Prior studies revealed SBR-induced enterocyte proliferation requires the expression of p21 waf1/cip1 . As deficient expression of p21 waf1/cip1 has been shown to result in reduced numbers of hematopoietic stem cells. We sought to test the hypothesis that p21 waf1/cip1 deficiency similarly perturbs the intestinal stem cell population after SBR. Methods Control ( n = 21; C57Bl/6) and p21 waf1/cip1 -null mice ( n = 30) underwent 50% proximal SBR or sham operation. After 3 days, the ileum was harvested and the crypt stem cell population evaluated by counting crypt base columnar cells on histologic sections, determining the expression of Musashi-1 and Lgr5, and profiling the transcriptional expression of 84 known stem cell genes. Results There were no significant differences in crypt base columnar cells, expression of Musashi-1 or Lgr5, or in stem cell gene expression after SBR in control mice. Furthermore, there were no differences in these markers between controls and p21 waf1/cip1 -null mice. Conclusion In contrast with bone marrow stem cells, the stem cell population of the gut is unaffected by deficient expression of p21 waf1/cip1 . Additional mechanisms for the role of p21 waf1/cip1 in small bowel proliferation and adaptation after massive SBR must be considered.
Accumulation, Distribution, and Toxicity of Copper in Sediments of Catfish Ponds Receiving Periodic Copper Sulfate Applications

Copper sulfate (CuSO 4 ) is applied periodically to commercial channel catfish (Ictalurus punctatus) ponds as an algicide or parasiticide. Current understanding of the chemistry of copper in soil-water systems suggests that copper may accumulate in pond sediments, although the forms and potential bioavailability of copper in catfish pond sediments are not known. This study investigated the accumulation and distribution of copper in the sediment of catfish ponds receiving periodic additions of CuSO 4 .5H 2 O. All ponds were constructed in Sharkey (very-fine, smectitic, thermic Chromic Epiaquert) soil. Nine 0.40-ha ponds received 59 applications of 2.27 kg CuSO 4 .5H 2 O per application per pond over 3 yr; no CuSO 4 .5H 2 O applications were made to nine additional ponds. Total Cu concentration in the sediments of CuSO 4 .5H 2 O-amended catfish ponds (172.5 mg kg -1 ) was four to five times higher than that in the sediments of nonamended ponds (36.1 mg kg -1 ). Copper accumulated in catfish pond sediments at a rate of 41 μg kg -1 dry sediment for each 1 kg ha -1 of CuSO 4 . 5H 2 O applied to ponds. Copper in the sediments of amended ponds was mainly in the organic matter-bound (30.7%), carbonate-bound (31.8%), and amorphous iron oxide-bound (22.1%) fractions with a considerable fraction (3.4%; 3 to 8 mg kg -1 ) in soluble and exchangeable fractions. This indicates that Cu accumulates differentially in various fractions, with proportionally greater initial accumulation in potentially bioavailable forms. However, toxicity bioassays with amphipods (Hyallela azteca) and common cattail (Typha latifolia L.) indicated that the effect of exposure to amended or nonamended pond sediments was not different.
Limit-cycle vibrations of a rolling cylinder

Abstract An explanation for a violent vibration of a high-speed textile yarn winder is proposed based on the hypothesis that variations in radial compliance around the circumference of the yarn cylinder make the smooth winding process unstable due to parametric excitation. The amplitude of the resulting limit cycle depends on the non-linearity in the radial compliance. An analytical procedure for predicting the limit-cycle amplitude is developed and applied to a specially constructed mechanical model of a yarn winder. The actual response of the mechanical model is accurately predicted when its measured dynamic properties are inserted in the analysis.
Greedy rankings and arank numbers

A ranking on a graph is an assignment of positive integers to its vertices such that any path between two vertices of the same rank contains a vertex of strictly larger rank. A ranking is locally minimal if reducing the rank of any single vertex produces a non-ranking. A ranking is globally minimal if reducing the ranks of any set of vertices produces a non-ranking. A ranking is greedy if, for some ordering of the vertices, it is the ranking produced by assigning ranks in that order, always selecting the smallest possible rank. We will show that these three notions are equivalent. If a ranking satisfies one property it satisfies all three. As a consequence of this and known results on arank numbers of paths we improve known upper bounds for on-line ranking of paths and cycles.
Comparative discriminative stimulus properties of dl-rmcathinone, d-amphetamine, and cocaine in rats

Abstract The discriminative stimulus properties of dl -cathinone ( dl -CAT), d -amphetamine ( d -A), and cocaine (COC) were compared and effects of haloperidol pretreatment on these properties were studied in rats. The ED50's of each drug were also determined. Stimulus generalization (i.e., greater than 75% of responses occuring on the drug lever) occured with each of the three training drugs to all three test drugs. The degree of generalization was less between d -amphetamine and dl -cathinone than between d -amphetamine and cocaine or between cocaine and dl -cathinone. No significant differences were observed among the ED50's of each test drug obtained in all three training groups. Pretreatment with haloperidol failed to alter the stimulus properties of dl -cathinone. Haloperidol administration did partially antagonize the stimulus complex induced by d -amphetamine and cocaine. It is concluded that all three agents share somewhat similar but not identical,stimulus properties. The stimulus properties of the training dose of d -amphetamine may be somewhat different from those of dl -cathinone and may be more dependent on functional dopaminergic pathways.
A Fully Automated LC/MS Method Development and Quantification Protocol Targeting 52 Carbamates, Thiocarbamates, and Phenylureas

We have developed a fully automated LC/MS method development and quantification protocol targeting 52 carbamtes, thiocarbamates, and phenylureas. This is a simple LC/MS method with direct injection; no postcolumn derivatization was required. The method utilized the Waters Alliance HT Chromatography System and the Waters ZQ 2000 mass spectrometer. System control and data processing was by MassLynx 4.0 with QuanLynx Application Manager. Analyte separation was accomplished by Waters Symmetry reversed-phase C8 column. An ammonium acetate water/acetonitrile binary gradient was used for the separation. The MS multichannel ability minimized the LC method development time with less demand on chromatographic peak resolution. Quantification results were obtained for 46 analytes out of the 52 targets. The coefficients of determination ranged from 0.886 to 0.999. The automated LC/MS protocol has sufficient sensitivity to accommodate the current EPA requirements. The limits of detection (3 times the S/N) ranged from 0...
Inductive role of the nerve cord in regeneration of isolated postpharyngeal body sections of Dugesia dorotocephala.

Lateral cordless fragments isolated from the postpharyngeal section of Dugesia dorotocephala formed a large normal head at a 90° angle to the original antero-posterior polarity; postcerebrally, only a hump of undifferentiated tissue developed. This “head-hump” pattern, and also other types observed in previous studies of lateral fragments, were attributed to the absence of the nerve cord. In order to confirm the inductive role of the nerve cord and to eliminate the possibility that the “head-hump syndrome” was due to the relative proportions of other tissues besides nerve, body fragments of two experimental groups were observed: (1) the five types of fragments which had no nerve cord but had varying proportions of other tissues present formed primarily “head-hump” types of regenerates. (2) Almost all fragments which had varying amounts of nerve cord present but the same proportions of other tissues formed regenerates of normal body proportions. Therefore, the absence of the nerve cord does determine the “head-hump syndrome”. Isolated postpharyngeal half segments containing one nerve cord were allowed to regenerate for varying periods of time before the lateral cordless fragment was isolated. The number of “head-hump” regenerates from lateral fragments isolated after a one-day or longer contact with the nerve cord gradually decreased, and the number of regenerates with incomplete head development or which were more elongated postcerebrally increased. These results indicate that the nerve cord acts gradually to determine the differentiation of specific tissues rather than rapidly to determine the overall body plan.
Interfacing of CE in a PVP matrix to ion trap mass spectrometry : Analysis of isomeric and structurally related (N-acetylamino)fluorene-modified oligonucleotides

This work demonstrates the interfacing of capillary electrophoresis in a poly(N-vinylpyrrolidone) (PVP) solution to electrospray ionization ion trap mass spectrometry (ESI-ITMS). This methodology was used for on-line analysis of modified and unmodified oligonucleotides. Oligonucleotides were covalently modified using the model carcinogen 2-(N-acetoxy-N-acetylamino)fluorene. In the presence of PVP, separation was achieved for a set of isomeric (N-acetylamino)fluorene (AAF)-modified oligonucleotides differing only in their base sequences, while open-tube control experiments showed no separation between these compounds. The resolved analytes were identified by ESI-ITMS with negative ion detection. On-line acquisition of MS and MS/MS data allowed unambiguous identification of all structural isomers. Baseline separation was also accomplished for a 10-compound mixture containing a series of five nonisomeric AAF-modified oligonucleotides and their unmodified parent oligonucleotides.
Effects of individual housing and stressor exposure upon the acquisition of watermaze escape

Abstract The watermaze tasks of R.G.M. Morris (1981, Learning and Motivation , 12 , 239–260) have been used to study the biological bases of spatial learning and memory in rats. These tasks enable the specific study of spatial learning by contrasting performance on two escape tasks. Both tasks allow a rat to escape from a pool of cool water by locating a small escape platform. They differ in the use of a plainly visible platform with varying location in the nonspatial task, versus a hidden platform with constant location in the spatial task. Rats learn to locate both kinds of platform with impressive and nearly equal speed. We report that while rats housed in groups show fast and reproducible acquisition of these tasks, rats housed individually show a gradual decrease in acquisition performance of both spatial and nonspatial tasks. This deficit is detectable after 2 or 3 weeks of isolation, and continues to increase in severity thereafter. The deficit is reversible by a brief period of group housing, by episodic exposure to loud noise, and by episodic restraint. The efficacy of these corrective treatments declines when isolation is prolonged beyond 3 weeks. These findings are interpreted as indicating an abnormality in stress responsiveness in the individually housed animals. The implications of these findings for experiments studying watermaze acquisition in individually housed animals are examined.
Lysis of adult ventricular myocytes by cells infiltrating rejecting murine cardiac allografts

Background Immunologic mechanisms that mediate myocardial cell injury during rejection are not fully understood. We therefore investigated whether cells that infiltrate rejecting cardiac allografts are capable of directly injuring myocytes and whether this injury resembles that produced by cytotoxic T lymphocytes (CTLs) that are generated in a mixed lymphocyte reaction (MLR). Methods and Results Heart-infiltrating cells (HICs) were isolated from murine heterotopic BALB/c cardiac allografts undergoing rejection 6 to 8 days after transplantation into C57BL/6 mice. An in vitro model system of cultured adult murine ventricular myocytes was developed to facilitate investigation of cell-mediated myocyte injury. Isolated adult myocytes were incubated with either HICs or MLR effector cells, and myocyte death was quantified by counting the number of rod-shaped myocytes excluding trypan blue. The frequency of donor-reactive CTLs was similar in the HIC and MLR populations, as assessed by limiting dilution analysis. However, HICs were less efficient at killing donor-strain myocytes than were MLR cells. CTL-mediated cell lysis occurred by 6 hours, whereas myocyte injury produced by HICs was more gradual, with considerable cytotoxicity occurring between 12 and 24 hours. Furthermore, whereas MLR cells lysed only donor-strain myocytes, HIC lysed donor, third-party, and syngeneic myocytes. Treatment of MLR cells and HICs with anti-CD8 antibody plus complement produced a much greater inhibition of MLR cytotoxicity than of HIC cytotoxicity. Conclusions These data demonstrate that only a small component of myocyte injury mediated by allograft-infiltrating cells can be ascribed to CTLs within the infiltrating cell population. These findings suggest that cell types associated with a delayed-type hypersensitivity response, as well as CTLs, cause myocyte injury during cardiac rejection.
Design and Control of Gas-Phase Reactor/Recycle Processes with Reversible Exothermic Reactions

A gas-phase reactor with reversible exothermic reactions is the classical example of the many tradeoffs between operating costs and capital costs. Because per-pass conversion is limited by chemical equilibrium, recycle is almost always needed, and this gas recycle is expensive because of the high capital cost and high energy cost of gas compression. At low temperatures, conversion is limited by small kinetic reaction rates, and large reactors are needed. At high temperatures, conversion is limited by the decrease in the chemical equilibrium constant, and large recycle flowrates are needed. Thus, the optimum design of this type of system requires finding the best set of design optimization variables: reactor temperature, reactor size, and gas recycle flowrate. In systems containing inert chemical components that must be purged from the system, an additional design optimization variable is present: purge flowrate or inert composition in the recycle gas. Higher inert compositions require larger reactors an...
Learning to Solve Addition and Subtraction Word Problems Through a Structure-Plus-Writing Approach.

The aim of this study was to design and field-test instruction intended to help students construct knowledge about addition and subtraction story problems and determine if this knowledge would transfer to actually solving problems. The study tests two related hypotheses: (a) structure-pluswriting instruction will result in improved word-problem solving, and (b) this improvement will be more enduring than that resulting from a more traditional heuristic and practice-based approach. To test these hypotheses, 401 third-grade and fourth-grade students from 21 classrooms in six schools participated in a study in which the problem solving of children taught by a structure-plus-writing approach was compared to that of (a) a control group receiving no explicit instruction in arithmetic word-problem solving, and (b) a group receiving instruction based largely on practice and explicit heuristics. Both hypotheses were supported by the results. The structure-plus-writing group outperformed the group receiving practice and explicit heuristics instruction. Moreover, the structure-plus-writing group not only maintained this superiority but actually widened the gap, as shown by retention test results 10 weeks after treatment. The effectiveness of instruction based on a structured approach to authoring arithmetic word problems was strongly supported.
Thick filaments in vascular smooth muscle.

Two sets of myofilaments were demonstrated after incubation of strips of rabbit portal-anterior mesenteric vein under moderate stretch in a physiological salt solution. Thick filaments had a mean diameter of 18 nm and reached a maximum length of 1.4 µm with a mean length of 0.61 µm. In transverse sections, 2.5–5 nm particles were resolved as subunits of the thick filaments. Thin filaments had an average diameter of 8.4 nm and generally conformed to the structure believed to represent actin filaments in smooth and striated muscles. In the areas of maximum concentration there were 160–328 thick filaments/µm2 and the lowest ratio of thin to thick filaments was 12:1. Thick filaments were present in approximately equal numbers in vascular smooth muscle relaxed by theophylline, in Ca++-free solution, or contracted by norepinephrine. The same preparatory procedures used with vascular smooth muscle also enabled us to visualize thick filaments in guinea pig and rabbit taenia coli and vas deferens.
How Reliable Are Local Projection Estimators of Impulse Responses

Abstract We compare the finite-sample performance of impulse response confidence intervals based on local projections (LPs) and vector autoregressive (VAR) models in linear stationary settings. We find that in small samples, the asymptotic LP interval often is less accurate than the bias-adjusted bootstrap VAR interval, notwithstanding its excessive average length. Although the asymptotic LP interval has adequate coverage in sufficiently large samples, its average length still far exceeds that of bias-adjusted bootstrap VAR intervals with comparable accuracy. Bootstrap LP intervals (with or without bias correction) and asymptotic VAR intervals are shorter on average, but they often lack coverage accuracy in finite samples.
Regulation of flavin-containing monooxygenase 1 expression by ying yang 1 and hepatic nuclear factors 1 and 4.

The flavin-containing monooxygenases (FMOs) are important for the oxidation of a variety of environmental toxicants, natural products, and therapeutics. Consisting of six family members (FMO1–5), these enzymes exhibit distinct but broad and overlapping substrate specificity and are expressed in a highly tissue- and species-selective manner. Corresponding to previously identified regulatory domains, a YY1 binding site was identified at the major rabbit FMO1promoter, position −8 to −2, two overlapping HNF1α sites, position −132 to −105, and two HNF4α sites, position −467 to −454 and −195 to −182. Cotransfection studies with HNF1α and HNF4α expression vectors demonstrated a major role for each of these factors in enhancing FMO1 promoter activity. In contrast, YY1 was shown by site-directed mutagenesis to be dispensable for basal promoter activity but suppressed the ability of the upstream domains to enhance transcription. Finally, comparisons between rabbit and humanFMO1 demonstrated conservation of each of these regulatory elements. With the exception of the most distal HNF4α site, each of the orthologous human sequences also was able to compete with rabbit FMO1 cis-elements for specific protein binding. These data are consistent with these same elements being important for regulating human FMO1 developmental- and tissue-specific expression.
Cumulative atomic multipole moments for molecular crystals from ab‐initio crystal orbital wave functions and for molecules in excited states from ab‐initio MRD‐CI wave functions

Compact representation of molecular charge distribution in molecular crystals has been derived from ab-initio crystal orbital wavefunction within the framework of cumulative atomic multipole moment (CAMM) expansion. Results for HF, CO2, and cubane C8H8 crystals have been compared with values calculated for corresponding clusters within conventional LCAO MO SCF approach. CAMM technique has also been used to represent molecular charge distribution in electronic excited states using CI wavefunction obtained from multireference configuration interaction (MRD-CI) calculations. This approach supplements previously introduced uncorrelated and correlated CAMM's and allows accurate nonempirical modeling of electrostatic effects involving molecules in excited states or in crystalline environment. Improved point charge model derived from CAMM has been also described.
Circuitry and dynamics of human transcription factor regulatory networks.

SUMMARY The combinatorial cross-regulation of hundreds of sequence-specific transcription factors (TFs) defines a regulatory network that underlies cellular identity and function. Here we use genome-wide maps of in vivo DNaseI footprints to assemble an extensive core human regulatory network comprising connections among 475 sequence-specific TFs and to analyze the dynamics of these connections across 41 diverse cell and tissue types. We find that human TF networks are highly cell selective and are driven by cohorts of factors that include regulators with previously unrecognized roles in control of cellular identity. Moreover, we identify many widely expressed factors that impact transcriptional regulatory networks in a cell-selective manner. Strikingly, in spite of their inherent diversity, all cell-type regulatory networks independently converge on a common architecture that closely resembles the topology of living neuronal networks. Together, our results provide an extensive description of the circuitry, dynamics, and organizing principles of the human TF regulatory network.
DIFFUSION TENSOR IMAGING STUDY OF THE FORNIX IN FIRST EPISODE SCHIZOPHRENIA AND IN HEALTHY CONTROLS

Background The fornix is a compact bundle of white matter fibers that project from the hippocampus to the mamillary bodies and septal nuclei. Its association with memory, as well as with symptoms in schizophrenia, has been reported in chronic schizophrenia. The purpose of this study is to determine whether or not fornix abnormalities are evident at the onset of schizophrenia.
Word Class Distinctions in Second Language Acquisition: An Experimental Study of L2 Spanish.

Although the problem of word class has been explored in numerous first language studies, relatively little is known about this process in SLA. The present study measures second language (L2) learners’ knowledge of word class distinctions (e.g., noun vs. adjective) in a variety of syntactic contexts. English-speaking learners of Spanish from third-semester and third-year courses (N = 240) completed a receptive task that presented contrasting forms belonging to the same word family (e.g., feliz “happy” and felicidad “happiness”). The results indicate that learners from both groups are often unable to distinguish among word classes. In particular, learners have significant difficulty in discriminating between adjectives and nouns. Although ambiguous surface morphology contributes to word class confusions, the results suggest that L2 learners do not always recognize derivational suffixes that clearly mark word class. These difficulties are interpreted as stemming from weak syntactic morphological knowledge as well as incomplete knowledge of L2 distributional regularities.
Complications of balloon coarctation angioplasty

Abstract Balloon angioplasty for both native and recurrent coarctation of the aorta has become an established form of therapy in the treatment of this congenital cardiovascular defect in both children and adults. A significant reduction in upper extremity hypertension, a decrease in the transaortic pressure gradient, and angiographic enlargement at the site of narrowing occur in the majority of patients, both acutely and in mid-term follow-up studies. Acute and delayed complications of this modality of treatment have been well described and include vascular access injury, neurologic events (stroke, transient ischemic attack), reactive hypertension, arrhythmias and sudden cardiac arrest, acute aortic dissection or rupture, and the late development of aneurysm at the dilated site. This review will discuss in depth the incidence and risk factors associated with these complications and the treatment and prevention modalities that can be utilized to decrease the risk of these untoward events.
Sensitization of thermotolerant SCK cells to hyperthermia and freezing with reduction of intracellular pH: Implications for cryosurgery

Background and Objectives During cryosurgery, cells frozen slowly at the outer part of the ice ball undergo severe dehydration and are subject to solute effects injury, which may be caused in part by protein denaturation. This study was undertaken to determine whether heat shock proteins (HSPs), the molecular chaperones that stabilize proteins against denaturation, have a protective effect on cells during slow freezing. In addition, we aimed to determine whether acidic conditions, similar to those found in many solid tumors, would effect this protection. Methods SCK cells were frozen at 5°C/min to −10°C or −20°C before or after induction of thermotolerance, and at neutral or low pH conditions. Lethal damage was determined by clonogenics. Results Clonogenic survival was decreased by 50% in thermotolerant cells frozen to −10°C after culture in acidic conditions (pH 6.6) compared with non-thermotolerant cells cultured at neutral pH. Induction of thermotolerance alone or low pH alone did not significantly sensitize SCK cells to freezing. All treatment groups were equally susceptible to killing when frozen to −20°C. Conclusions Our results show that induction of thermal tolerance does not protect SCK cells against subsequent freezing injury and that a low pH environment actually sensitizes these cells to freeze injury. J. Surg. Oncol. 2003;82:160–169. © 2003 Wiley-Liss, Inc.
Why are bacteria different from eukaryotes

Julie Theriot graduated from the Massachusetts Institute of Technology as a double major in biology and physics, and her career as a biologist ever since has been notable for the quantitative rigor of her approach to the messy world of biology. As a graduate student at the University of California San Francisco, she began studying the subversion of actin polymerization by pathogenic bacteria in animal cells, and more general issues of bacterial and eukaryotic motility remain the focus of her group’s research at Stanford University. With colleagues Rob Phillips, Jane Kondev, and Hernan Garcia, she has published a textbook, Physical Biology of the Cell, exploring the applications of mathematical and physical modeling in cell biology. In the interview here, she applies a breathtaking breadth of scholarship and a fearless imagination to the fundamental question of the difference between bacterial cells and ours.
An Investigation of the Impact of Guessing on Coefficient α and Reliability.

Guessing is known to influence the test reliability of multiple-choice tests. Although there are many studies that have examined the impact of guessing, they used rather restrictive assumptions (e.g., parallel test assumptions, homogeneous inter-item correlations, homogeneous item difficulty, and homogeneous guessing levels across items) to evaluate the relation between guessing and test reliability. Based on the item response theory (IRT) framework, this study investigated the extent of the impact of guessing on reliability under more realistic conditions where item difficulty, item discrimination, and guessing levels actually vary across items with three different test lengths (TL). By accommodating multiple item characteristics simultaneously, this study also focused on examining interaction effects between guessing and other variables entered in the simulation to be more realistic. The simulation of the more realistic conditions and calculations of reliability and classical test theory (CTT) item stat...
Child Growth and Nutrition in Developing Countries: Priorities for Action

Child Growth and Nutrition in Developing Countries: Priorities for Action Per Pinstrup-Andersen. David Pelletier. and Harold Alderman. eds. Ithaca, NY: Cornell University Press, 1995.
Plane strain deformations near the tip of a contacting interfacial crack in locking materials

Abstract Plane strain deformations near the tip of a crack between two homogeneous and isotropic linear elastic bodies are studied on the assumptions that the two surfaces on either side of the crack contact each other and that the dilatation everywhere in the body is greater than or equal to a constant. The region where the dilatation equals the constant is called the locking region. It is found that one of the two half planes is in the locking state and the singularity index equals 1 2 .
Insulin Therapy in Home Health A Review

Diabetes mellitus, whether type 1 or type 2, offers special challenges to home health care providers. Treatment of diabetes can become increasing complex. While insulin remains the cornerstone of treatment in patients with type 1 diabetes (T1DM), the utilization of insulin to safely control blood glucose is also necessary for many patients with type 2 diabetes (T2DM). Many different insulin products are available, with each product possessing different characteristics and adverse effect potential. Balancing glycemic control with patient safety is paramount. The individualization of insulin therapy can be challenging for both patients and health care professionals. Regular evaluation of blood glucose monitoring is vital for patient assessment. This article provides a review of insulin for providers caring for patients in the home health care setting.
The Validity of the Cleeton Vocational SR Section1

Using one hundred University of Denver freshmen, Professor Cutler tested the validity of the Cleeton Vocational Inventory, Section SR, purporting to measure social adjustment. He correlated ratings earned with scores made on various tests. The account of the study and the conclusions reached are reported in this article.
Rats' Behavior during an Interfood Clock Is Altered by the Temporal Pattern of Interfood Stimuli

Abstract Rats exposed to a basic interfood clock (a sequence of four different 12-s lights) during a 48-s interfood interval (IFI) showed a characteristic distribution of behavior: responses near the feeder peaked after food presentations, locomotion away from the feeder peaked in the middle of the IFI, and nosing in the feeder peaked just before food. Rats (Group Shorter) receiving interfood stimuli that got progressively shorter (24 s–12 s–8 s–4 s–food) showed sharper increases in nosing in the feeder across the last half of the IFI than rats (Group Longer) receiving interfood stimuli that got progressively longer (4 s–8 s–12 s–24 s–food). Although locomotion away from the feeder increased in the middle of the IFI for Group Shorter, activity in front of the feeder increased at the beginning of the IFI for Group Longer. Overall, the data support a behavior systems view that motivational modes underlying IFI behavior have timing characteristics that fit better with some temporal patterns of interfood stimuli than with others. Specifically, a sequence of progressively longer duration cues controls increased activity near the feeder at the beginning of the IFI, but a sequence of progressively shorter duration cues facilitates locomotion in the middle of the IFI and feeder-related responses at the end of the IFI.
Real-Time Hypoglycemia Prediction Suite Using Continuous Glucose Monitoring: A safety net for the artificial pancreas

OBJECTIVE The purpose of this study was to develop an advanced algorithm that detects pending hypoglycemia and then suspends basal insulin delivery. This approach can provide a solution to the problem of nocturnal hypoglycemia, a major concern of patients with diabetes. RESEARCH DESIGN AND METHODS This real-time hypoglycemia prediction algorithm (HPA) combines five individual algorithms, all based on continuous glucose monitoring 1-min data. A predictive alarm is issued by a voting algorithm when a hypoglycemic event is predicted to occur in the next 35 min. The HPA system was developed using data derived from 21 Navigator studies that assessed Navigator function over 24 h in children with type 1 diabetes. We confirmed the function of the HPA using a separate dataset from 22 admissions of type 1 diabetic subjects. During these admissions, hypoglycemia was induced by gradual increases in the basal insulin infusion rate up to 180% from the subject9s own baseline infusion rate. RESULTS Using a prediction horizon of 35 min, a glucose threshold of 80 mg/dl, and a voting threshold of three of five algorithms to predict hypoglycemia (defined as a FreeStyle plasma glucose readings CONCLUSIONS The HPA will enable automated insulin-pump suspension in response to a pending event that has been detected prior to severe immediate complications.
Distributed algorithms for joint channel and RAT allocation in a cognitive digital home

The advances in radio design and wireless networking, along with the growth of multimedia home entertainment technologies, is creating the concept of a cognitive digital home requiring spectrum coexistence of various devices and networks of networks. Recent work in [1] has considered a framework for resource allocation in a cognitive digital home (CDH) with a multiplicity of radio access technologies (RAT) such as cognitive radios and legacy radio devices supporting heterogeneous applications. A spectrum manager, named the home genie node (HG), is used to coordinate spectrum coexistence across different services, with degrees of freedom ranging from transmission parameters such as frequency, bandwidth, and power, to the choice of radio access technology itself. Distributed algorithms for the resource allocation problems in a CDH, namely maximizing sum rate and maximizing service capacity, which have been previously solved using centralized approaches in [1], are designed and studied using partial Lagrangian decomposition techniques in this paper.
A concentric circle model of multivesicular body cargo sorting

Targeting of ubiquitylated transmembrane proteins into luminal vesicles of endosomal multivesicular bodies (MVBs) depends on their recognition by endosomal sorting complexes required for transport (ESCRTs), which are also required for MVB vesicle formation. The model originally proposed for how ESCRTs function succinctly summarizes much of the protein–protein interaction and genetic data but oversimplifies the coordination of cargo recognition and cannot explain why ESCRTs are required for the budding of MVB vesicles. Recent structural and functional studies of ESCRT complexes suggest an alternative model that might direct the next series of breakthroughs in understanding protein sorting through the MVB pathway.
The effectiveness of different types of pragmatic implications found in commercials to mislead subjects

Statements concerning the truthfulness of claims made in 16 tape-recorded commercials about fictitious products were judged by 40 college students. In half of the commercials a claim was directly asserted while in the other half the claims were pragmatically implied. Pragmatic implications are statements that lead a person to believe something that is neither explicitly stated nor necessarily implied. As expected based upon previous research, subjects often responded to implied claims as if they had been directly asserted (particularly by subjects in the short delay group). In addition, differences were found in the effectiveness of four different types of pragmatic implications for misleading subjects. Language: en
The Indian Subcontinent and ‘Out of Africa I’

The last few decades of paleoanthropological research has raised important issues about the rate and chrono-geographical extent of early hominin dispersals from Africa into Eurasia. Owing to its geographic position, the Indian subcontinent has a pivotal role to play in addressing such issues. This ecologically diverse landmass critically lies between the three sources of the oldest Homo fossils in the Old World and a southern route of expansion from Africa to Southeast Asia, through this region, has often been inferred. Claims of Plio-Pleistocene Oldowan assemblages have been made since the 1960s and come from the Narmada Valley in central India and from the Siwalik Hills in northern Pakistan and northern India. This paper critically reviews each of these claims and broadly discusses associated Plio-Pleistocene environments and geographic routes of entry. A large majority of these reported occurrences represents unsubstantiated claims and require further scientific verification through additional evidence. Tentative scenarios for the current absence of paleoanthropological evidence older than the Middle Pleistocene are also briefly discussed. This current lack of Oldowan assemblages, however, does not reflect an unquestionable absence of hominin occupation in the region. Ecologically conducive environments in the form of open grasslands, a seasonal monsoon regime, diverse fauna and eco-habitats (i.e., diverse hunting/scavenging opportunities), and an abundance of water and stone resources suggest the possible earlier presence of hominins in South Asia. Obviously, much more field research is required to test and confirm their early presence/absence in this geographically important region of the Old World.
Scientific Uncertainty in Risk Communication: An International Perspective

The NATO Advanced Research Workshop on “Scientific Uncertainty and Its Influence on the Public Communication Process” was held Sept. 8–10, 1994 in Paris, France. The workshop brought together experts from government and academia to discuss the question of scientific uncertainty and its effect on the conception, design, and transmission of information to the public. The goals and objectives of this workshop were (1) to share information and ideas about scientific uncertainty, and (2) to develop practical strategies to improve the effectiveness of science-based communication to the public. The potential benefits from this workshop included (1) the opportunity to share information and discuss issues relevant to scientific uncertainty and the public on an international scale, and (2) to determine whether there is need for ARW participants to convene a future meeting or conduct an international study. This article discusses the issues presented at the workshop.
Hindlimb muscular contraction reflexly decreases total pulmonary resistance in dogs

We have previously shown that contraction of the gracilis muscles of anesthetized dogs reflexly relaxes tracheal smooth muscle. We have also found that electrical stimulation of these afferents decreases total pulmonary resistance (TPR), a calculation that provides a functional index of airway caliber. Despite these findings, we have yet to show that muscular contraction reflexly decreases TPR. Therefore, in 11 alpha-chloralose-anesthetized dogs, we contracted the hindlimb muscles by electrically stimulating the L6-L7 ventral roots while measuring TPR breath by breath. We found that static contraction decreased TPR from 12.6 +/- 1.1 to 10.4 +/- 0.9 cmH2O X l-1 X s (P less than 0.05). This decrease was reflex in origin because it was prevented by section of the spinal roots innervating the working hindlimb. Repetitive twitch contractions (5 Hz) also reflexly decreased TPR, but the effect was smaller than that evoked by static contraction. The reflex decreases in TPR evoked by contraction were unaffected by propranolol but were abolished by atropine. We conclude that muscular contraction dilates the airways by a reflex mechanism whose efferent arm consists of a withdrawal of cholinergic input to airway smooth muscle.
Plasma Throinboplastin Component (PTC) Deficiency A New Disease Resembling Hemophilia

Summary1. A severe hemorrhagic disease, characterized by a prolonged whole blood coagulation time due to the delayed formation of thrombin, has been described. The patient with this disease was found to have normal plasma concentrations of all the previously described coagulation factors. 2. The corrective factor in normal plasma or serum can be removed by barium sulfate adsorption. A method for the partial purification and concentration of the patient's missing factor has been outlined. The defect in the patient's blood may be corrected by the addition of plasma free of previously described thromboplastin components (e.g. platelet-free hemophilic plasma), as well as by small amounts of tissue thromboplastin. The name plasma thromboplastin component (PTC) has been assigned to this previously undescribed coagulation factor.
Studies on Film-Forming Yeasts. Acid Production by Zygopichia And Zygohansenula

Film-forming yeasts are of widespread occurrence and of considerable economic importance. Representatives belong to the sporogenous genera Pichia, Zygopichia, Hansenula, Zygohansenula, and Debaryomyces; and to the asporogenous genus Mycoderma. They are frequently found growing on salt brines used for the storage of various food products; Mrak and Bonar (1939) in a study of the taxonomy and salt tolerance of certain film yeasts include a good bibliography. Fermented beverages of many types have yielded new forms. In some cases a particular quality of the drink has been attributed to these yeasts (e.g., the "flor" of sherry, cf. Hohl and Cruess, 1939) while in other cases they have been looked upon as nuisances because of their ability to oxidize ethanol rapidly or to impart "off-flavors." Danzig beer, English cider, native African wine, and Mexican pulque are but a few of the aqueous habitats. Ruiz Oronoz (1936) isolated Zygopichia farinosa from the exudate of ash trees in Mexico. In connection with taxonomic work (1944) on the genus Zygosaccharomyces, wherein it was found advisable to transfer certain misplaced film-forming species to Zygopichia, the author became interested in the close relationship between the genera Pichia and Hansenula. Mrak, Phaff, Vaughn, and Hansen (1942) have pointed out that only the ability to utilize nitrate now separates the two genera and they believe it may become necessary to combine the two genera. (Zygopichia and Zygohansenula, along with Zygosaccharomyces, occupy the rank of subspecies in StellingDekker's (1931) system, each being separated from the parent