cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of the growth and degradation of poly(glycolic acid) and poly(ε‐caprolactone) brushes

The growth and degradation of poly(glycolic acid) (PGA) and poly(e-caprolactone) (PCL) brushes were compared. Using tin (octanoate) as the catalyst, optimal conditions were found for growth of each polyester brush from the hydroxy-terminated silicon surface via ring-opening polymerization. PCL brushes grew thicker at elevated temperatures but the thickest PGA brushes grew at room temperature. Unlike bulk polyesters that can degrade under both acidic and basic conditions, the confined surface polyester brushes only degraded under neutral or basic conditions. The degradation mechanism of grafted polyester brushes was probed through a blocking test. It was shown that the terminal hydroxy groups of these polyester brushes were essential to the degradation process indicating a preferential backbiting mechanism. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4643–4649
The frontiers of time-resolved macromolecular crystallography: movies and chirped X-ray pulses.

Three important frontiers of ultrafast time-resolved macromolecular crystallography are presented: extension of this technique to other biological systems; further developments in the elucidation of mechanism through the analysis of time-dependent movies to extract the underlying, time-independent, intermediate structures; and enhanced time resolution. The last is intimately linked with the nature of the pump–probe experiment itself, with the sources of random and, particularly, systematic experimental error, and with the factors that contribute to overall time resolution. All experiments to date have utilized the unchirped X-ray pulses that are emitted by synchrotron sources. Chirped pulses offer certain advantages for ultrafast X-ray experiments such as those based on Laue diffraction. An energy-chirped pulse maps photon energy into time; a Laue diffraction experiment maps photon energy into detector space. Hence, a Laue experiment with an energy-chirped pulse maps time into space. The proposed sub-picosecond photon source could provide an excellent source of intense, chirped hard X-rays for such experiments.
Small-gauge, sutureless pars plana vitrectomy to manage vitreous loss during phacoemulsification

This technique manages vitreous prolapse associated with posterior capsule rupture during phacoemulsification by performing small-gauge pars plana vitrectomy with a sutureless, self-sealing incision performed in a closed chamber, maintaining normal intraocular pressure. A high-speed cutter exerts minimal traction on the vitreous. Accessibility to the vitreous through the pars plana is better, ensuring more complete removal of the vitreous and restoration of normal anatomy.
Pharmacokinetic and fetal cardiovascular effects of enalaprilat administration to maternal rhesus macaques

Abstract OBJECTIVE: The purpose of this study was to determine the extent of placental transfer of the angiotensin-converting enzyme inhibitor enalaprilat and the effects on maternal and fetal cardiovascular parameters. STUDY DESIGN: Between gestational days 122 and 126 (term 167 days) five rhesus macaques underwent surgery for implantation of maternal and fetal vascular catheters. At least 4 days after surgery maternal and fetal blood pressures and heart rates were recorded for 1 hour. This was followed by a 5-minute maternal venous infusion of saline solution vehicle and recording for an additional hour. Enalaprilat was then infused over 5 minutes through the maternal femoral artery at doses of 0.05, 0.1, or 0.2 mg/kg. Maternal and fetal arterial blood samples were collected for determination of blood gas status and plasma enalaprilat concentrations. RESULTS: Enalaprilat rapidly crossed the placenta, and fetal values for areas under the concentration time curve were 50% to 65% of maternal values across dose groups. Drug was retained in the fetal plasma approximately threefold to fourfold longer than in maternal plasma. Maternal heart rate, blood pressure, arterial Po2 and pH were unchanged after enalaprilat infusion, as were fetal heart rate and blood gases. In contrast, fetal arterial pressure decreased significantly (19% to 23%, p 0.05). CONCLUSIONS: Results from this study indicate that enalaprilat rapidly crosses the primate placenta with a single intravenous administration to the mother, resulting in significant and prolonged reduction of fetal arterial pressure. Because maternal cardiovascular parameters were unaffected, enalaprilat appears to have a direct effect on fetal arterial pressure. (Am J Obstet Gynecol 1996;175:50-5.)
The Second Describing Function and Removal of Jump Resonance by Signal Stabilization

Describing function for analysis of feedback control systems with time-invariant nonlinear elements, simplifying derivation by taking derivative of output of nonlinear element with respect to input
Dermatofibrosarcoma protuberans: treatment results of 35 cases.

Abstract Background and purpose : This study evaluates the treatment results of patients with dermatofibrosarcoma protuberans. Patients and methods : Between August 1987 and July 1998, 35 consecutive patients with pathologically proved dermatofibrosarcoma protuberans received surgery with or without radiation therapy. Their treatment results were analyzed retrospectively. Results : The patient ages ranged from 5 to 67 years (median 37 years). There were 24 males and 11 females. The anatomic sites of tumor were: trunk in 21, extremity in eight, and head and neck region in six. The maximal dimension of tumor ranged from 1.5 to 25 cm. Surgery techniques included local excision and wide excision with or without graft or flap. Adjuvant radiation therapy was given to 11 patients, with a dose ranging from 46 to 68 Gy (one pre-operative, ten post-operative). At a median follow-up of 50 months (range 11–131 months), there were 11 patients (nine patients without radiation therapy) who developed local failure. Salvage therapy (excision with or without radiation therapy) was given to all of them, and ten achieved disease control. Some patients had treatment-related moderate cosmetic or functional problems. Conclusions : Dermatofibrosarcoma protuberans is a malignancy of a high cure rate, and adjuvant radiation therapy can reliably decrease the local recurrence rate and prevent mutilation and functional deficit caused by repeated surgery.
Exploration of ligands to the Qi site semiquinone in the bc 1 complex using high-resolution EPR

Pulsed EPR spectroscopy was used to explore the structural neighborhood of the semiquinone (SQ) stabilized at the Qi site of the bc 1 complex of Rhodobacter sphaeroides (EC 1.10.2.2) and to demonstrate that the nitrogen atom of a histidine imidazole group donates an H-bond to the SQ. Crystallographic structures show two different configurations for the binding of ubiquinone at the Qi site of mitochondrial bc 1 complexes in which histidine (His-201 in bovine sequence) is either a direct H-bond donor or separated by a bridging water. The paramagnetic properties of the SQ formed at the site provide an independent method for studying the liganding of this intermediate species. The antimycin-sensitive SQ formed at the Qi site by either equilibrium redox titration, reduction of the oxidized complex by ascorbate, or addition of decylubihydroquinone to the oxidized complex in the presence of myxothiazol all showed similar properties. The electron spin echo envelope modulation spectra in the 14N region were dominated by lines with frequencies at 1.7 and 3.1 MHz. Hyperfine sublevel correlation spectroscopy spectra showed that these were contributed by a single nitrogen. Further analysis showed that the 14N nucleus was characterized by an isotropic hyperfine coupling of ∼0.8 MHz and a quadrupole coupling constant of ∼0.35 MHz. The nitrogen was identified as the N-ϵ or N-δ imidazole nitrogen of a histidine (it is likely to be His-217, or His-201 in bovine sequence). A distance of 2.5–3.1 A for the O–N distance between the carbonyl of SQ and the nitrogen was estimated. The mechanistic significance is discussed in the context of a dynamic role for the movement of His-217 in proton transfer to the site.
Structural transformation and growth of merchandise trade of low-income economies 1980–1992

The Heckscher-Ohlin Vanek theorem, which predicts a direct relationship between exports and greater supply of factors used to produce those exports, performs only 50 percent of the time. However, there is no alternative theory which explains such a relationship. This paper analyzes the growth of merchandise trade of low-income countries, with particular reference to the growth of exports and net exports as these countries move from the predominantly agricultural goods producing era to the manufactured goods producing era. Results suggest, among other things, that industrial structure and governmental policies play an important role in the growth of merchandise trade.
On Quasi-Invariant Measures in Uniquely Ergodic Systems

Let X be a compact metrizable space, ~ (X) its G-algebra of Borel sets, and let T be a homeomorphism of X. We denote for a Borel measure # on X by T/2 the measure that is obtained by setting TI~(A)=I~(T -1 A), A e ~ . There exists always a Borel probability measure # such that T/2=# [10, p. 76]. If there exists only one such invariant measure then T is called uniquely ergodic. A measure # is called quasi-invariant for T if T# is equivalent to/2. In this paper we show that every uniquely ergodic homeomorphism of a compact metrizable space whose invariant measure is non-atomic possesses more than countably many non-atomic quasi-invariant ergodic measure classes. The problem of describing such measure classes has arisen in the theory of unitary representations of locally compact groups [12, p. 650]. In fact, we shall prove a more precise result. To state this result we need more terminology. Let (Y, ~ ) be a Borel structure and let ~ be an equivalence relation in Y. It can happen that the G-algebra ~ contains sets A i, i eN , such that
Bridging the Economic Divide Within Countries: A Scorecard on the Performance of Regional Policies in Reducing Regional Income Disparities

Abstract Regional inequalities represent a continuing development challenge in most countries. There is a presumption in development economics that decentralized fiscal arrangements would lead to ever-widening regional inequalities. This paper provides an empirical test of this hypothesis. We conclude that regional development policies have failed in almost all countries, federal and unitary alike. Still, federal countries do better in restraining regional inequalities, because of the greater political risk these disparities pose for such countries. Our findings also suggest that countries experiencing divergence tend to focus on interventionist policies, while those experiencing convergence have taken a hands-off approach to regional development and instead focus on promoting an economic union by removing barriers to factor mobility and ensuring minimum standards in basic services across the country.
Depictions of the Irish in Frank Webb’s The Garies and Their Friends and Frances E. W. Harper’s Trial and Triumph

In the 1991 movie The Commitments, Jimmy, the manager of an aspiring Dublin soul band, convinces a band member skeptical of playing African American music that the band's class background makes them black. He argues: "The Irish are the Blacks of Europe. The Dubliners are the Blacks of Ireland. And the Northside Dubliners are the Blacks of Dublin. So say it once, say it loud: I'm Black and I'm proud." In his provocative remark, Jimmy equates low class position with blackness, collapsing class and race. Jimmy draws unusually liberating results from this comparison when the Irish band is allowed to sing the powerful black music of soul, but in likening working-class Irish and African Americans, he is hardly being original. Rather, Jimmy plays upon a comparison that was first widespread in nineteenth-century America. Between 1845 and 1889, approximately three million Irish immigrated to the United States (Foner, "Class" 6). Especially during the famine decade of 1845-1855, the majority were extremely impoverished and poorly educated. Although not enslaved, in their educational and financial status Irish immigrants in this decade resembled the majority of African Americans. This similarity posed a dilemma for other Euro-Americans who, throughout the nineteenth century, were attempting in literature and popular culture to highlight racial differences and smooth over class divisions.1 Instead of recognizing the class similarities between Irish and African Americans, many Euro-Americans painted Irish-Americans black, attributing their low class status to their alleged physical or even racial difference from other EuroAmericans. In contrast, African American writers such as Frank
Evaluation of Short-to-Medium Range Streamflow Forecasts Obtained Using an Enhanced Version of SRM1

Harshburger, Brian J., Karen S. Humes, Von P. Walden, Brandon C. Moore, Troy R. Blandford, and Albert Rango, 2010. Evaluation of Short-to-Medium Range Streamflow Forecasts Obtained Using an Enhanced Version of SRM. Journal of the American Water Resources Association (JAWRA) 46(3):603-617. DOI: 10.1111/j.1752-1688.2010.00437.x Abstract: As demand for water continues to escalate in the western United States, so does the need for accurate streamflow forecasts. Here, we describe a methodology for generating short-to-medium range (1 to 15 days) streamflow forecasts using an enhanced version of the Snowmelt Runoff Model (SRM), snow-covered area data derived from MODIS products, data from Snow Telemetry stations, and meteorological forecasts. The methodology was tested on three mid-elevation, snowmelt-dominated basins ranging in size from 1,600 to 3,500 km2. To optimize the model performance and aid in its operational implementation, two enhancements have been made to SRM: (1) the use of an antecedent temperature index method to track snowpack cold content, and (2) the use of both maximum and minimum critical temperatures to partition precipitation into rain, snow, or a mixture of rain and snow. The comparison of retrospective model simulations with observed streamflow shows that the enhancements significantly improve the model performance. Streamflow forecasts generated using the enhanced version of the model compare well with the observed streamflow for the earlier leadtimes; forecast performance diminishes with leadtime due to errors in the meteorological forecasts. The three basins modeled in this research are typical of many mid-elevation basins throughout the American West, thus there is potential for this methodology to be applied successfully to other mountainous basins.
On the rate of the reaction of ammonia with oxygen atoms

Abstract Absolute rate constants for the reaction of O( 3 P) with ammonia were measured over the temperature range 448–841 K by means of a laser photolysis-chemiluminescence technique. The data were fitted with the following Arrhenius expression: k = 3.42 × 10 −11 exp[-(9000 ± 600 cal/mole)/ RT ] cm 3 molecule −1 s −1 . Comparisons with literature data and predictions based upon the extrapolations to higher temperatures found in combustion are presented. The extrapolations are in agreement with recent shock-tube data and indicate that this reaction is more important in high-temperature ammonia oxidation than previously believed.
HOT TOPIC: Endocrinology Resources on the Internet

Endocrinologists and other medical subspecialists are increasingly turning to the Internet as a resource for use in clinical practice. The latest American Medical Association Study on Physicians’ Use of the World Wide Web reported that 37% of physicians have used the Internet, a substantial increase from the number identified on a similar survey completed 2 yr earlier (1). Market research surveys report that most practitioners use the Internet to search for information about specific diseases, to look up prescribing information, and to read online versions of medical journals (2). According to these sources, a significant number of practitioners also use e-mail to communicate with patients on a regular basis (3). Endocrinologists using the Internet in clinical practice face a number of challenges. The process of finding information involves sorting through an enormous quantity of content dispersed among an estimated 100,000 web sites containing health care information (4). The problem of identifying appropriate information is compounded by the fact that it is often difficult to distinguish physician-oriented resources from patient-oriented sites on summary review. Another formidable challenge lies in assessment of the quality of information available on the Internet. As an open-access resource, the Internet does not require any validation of information posted on individual web sites. The lack of enforced standards of documentation makes it difficult to determine whether specific content is reliable enough to be used as reference material. Among medical subspecialties, endocrinology is relatively well represented on the Internet, as evidenced by the number of topical pages retrieved with different search engine queries (Table 1). By way of demonstration, a search performed with a popular search engine using the general term “thyroid” returned a count of 465,000 indexed pages (5). A similar search performed using the specific term “diabetes mellitus” returned a count of 135,000 indexed pages (6). Common endocrine topics are highly visible on most of the major consumer-oriented web sites. A number of active online interest and support groups focus on discussion of specific endocrine disorders. This level of representation probably stems from the fact that clinical practice centers on the evaluation and treatment of chronic disorders incorporating specific knowledge, specialized diagnostic testing, and use of a wide variety of pharmacological agents and treatments. A selection of freely available, nonsubscription resources that may serve as useful starting points for exploration of the Internet are listed below. These include general and medical search engines, reference resources, and compilations of practice guidelines that have been selected based on their potential utility in real-time clinical practice. A home page address is provided for each site.
A Methodological Review of Faith-Based Health Promotion Literature: Advancing the Science to Expand Delivery of Diabetes Education to Black Americans

Non-traditional avenues, such as faith-based organizations (FBOs), must be explored to expand delivery of diabetes self-management education (DSME) to benefit Black Americans with type 2 diabetes (T2D). The purpose of this study was to methodologically review the faith-based health promotion literature relevant to Blacks with T2D. A total of 14 intervention studies were identified for inclusion in the review. These studies detailed features of methods employed to affect health outcomes that DSME similarly targets. Analysis of the faith-based studies’ methodological features indicated most studies used (1) collaborative research approaches, (2) pre-experimental designs, (3) similar recruitment and retention strategies, and (4) culturally sensitive, behaviorally oriented interventions with incorporation of social support to achieve positive health outcomes in Black Americans. Findings indicate FBOs may be a promising avenue for delivering DSME to Black Americans. Informed by the findings, a focused discussion on advancing the science of faith-based interventions to expand delivery of DSME to Black Americans with diabetes is provided.
How Did Six Highly Accelerated Gifted Students Fare in Graduate School

Paper written by Julian C. Stanley detailing the success of six young college graduates who were involved in graduate work. A table of the academic characteristics of the 13 young members of the Johns Hopkins University class of 1985 is included, as well as a memo on the care of young students in a non-parented residence situation.
Catching RNA polymerase in the act of binding: Intermediates in transcription illuminated by synchrotron footprinting

T he article by Sclavi et al. (1) in this issue of PNAS addresses “initiation,” the first step in transcription. Gene transcription is catalyzed in cells by large multisubunit proteins called RNA polymerases (RNAP). The eubacteria holoenzyme of RNAP is composed of five core subunits (α, α2, β, β′, and ω) that contain the amino acid residues required for the enzyme's catalytic activity. A sixth subunit (σ) guides RNAP to specific sequences on the genomic DNA (promoters) that mark the beginning of a gene or group of genes. Transcription consists of three phases: initiation, elongation, and termination, with each of these phases being highly regulated by DNA/RNA sequence and/or accessory proteins (Fig. 1). RNAP holoenzyme must first locate a promoter. After binding to the promoter, the RNAP holoenzyme and the bound DNA undergo a series of conformational changes from the closed to the open promoter complex, in which ≈12 base pairs of DNA denature to form a bubble of the two separated strands of DNA. Fig. 1. A schematic outline of the transcription cycle phases at the operon level of genomic organization. RNAP holoenzyme binds to the promoter and initiates RNA synthesis. The σ-subunit is released at the onset of elongation. RNA synthesis continues without dissociation of the RNAP core until the terminator sequence is reached when the RNA transcript and polymerase are released. The expanded diagram beneath the schematic depicts RNAP holoenzyme binding to a promoter and its isomerization to an open complex. RNAP holoenzyme is now poised to initiate RNA synthesis. After the addition of 6-10 RNA nucleotides, the σ-subunit is released, and the RNAP core continues to elongate the RNA chain until reaching a DNA terminator sequence. The terminator induces dissociation of the RNAP core and the completed RNA transcript from the DNA. RNAP core reassociates with …
Social and spatial inequities in exposure to flood risk in Miami, Florida

AbstractAlthough environmental justice (EJ) research in the United States has traditionally focused on technological hazards such as air pollution or hazardous waste, the adverse and unequal impacts of Hurricane Katrina have prompted researchers to examine the EJ implications of natural events such as hurricanes and floods. This paper contributes to this emerging literature on EJ and social vulnerability to natural hazards by analyzing racial/ethnic and socioeconomic inequities in the distribution of flood risk exposure in the Miami Metropolitan Statistical Area (MSA), Florida—one of the most hurricane-prone areas in the world and one of the most ethnically and socioeconomically diverse MSAs in the United States. Although previous studies have relied exclusively on the 100-year floodplain to assess the spatial extent of flood exposure, this study makes a systematic distinction between different types of flood zones on the basis of both the probability (100-year versus 500-year versus low/no risk) of flood...
Exploring the limits of DNA size: naphtho-homologated DNA bases and pairs.

A new design for DNA bases and base pairs is described in which the pyrimidine bases are widened by naphtho-homologation. Two naphtho-homologated deoxyribosides, dyyT (1) and dyyC (2), were synthesized and could be incorporated into oligonucleotides as suitably protected phosphoramidite derivatives. The deoxyribosides were found to be fluorescent, with emission maxima at 446 and 433 nm, respectively. Studies with single substitutions of 1 and 2 in the natural DNA context revealed exceptionally strong base stacking propensity for both. Sequences containing multiple substitutions of 1 and 2 paired opposite adenine and guanine were subsequently mixed and studied by several analytical methods. Data from UV mixing experiments, FRET measurements, fluorescence quenching experiments, and hybridizations on beads suggest that complementary “doublewide DNA” (yyDNA) strands may self-assemble into helical complexes with 1:1 stoichiometry. Data from thermal denaturation plots and CD spectra were less conclusive. Contro...
Mihály Károlyi and István Bethlen. Hungary

Bryan Cartledge. Mihaly Karolyi and Istvan Bethlen. Hungary. London: Haus Histories, 2009. Pp. viii. 176. (In the series of Makers of the Modern World. The Peace Conferences of 1919–23 and their Af...
A yeast-based chemical screen identifies a PDE inhibitor that elevates steroidogenesis in mouse Leydig cells via PDE8 and PDE4 inhibition.

A cell-based high-throughput screen (HTS) was developed to detect phosphodiesterase 8 (PDE8) and PDE4/8 combination inhibitors. By replacing the Schizosaccharomyces pombe PDE gene with the murine PDE8A1 gene in strains lacking adenylyl cyclase, we generated strains whose protein kinase A (PKA)-stimulated growth in 5-fluoro orotic acid (5FOA) medium reflects PDE8 activity. From our previously-identified PDE4 and PDE7 inhibitors, we identified a PDE4/8 inhibitor that allowed us to optimize screening conditions. Of 222,711 compounds screened, ∼0.2% displayed composite Z scores of >20. Additional yeast-based assays using the most effective 367 compounds identified 30 candidates for further characterization. Among these, compound BC8-15 displayed the lowest IC50 value for both PDE4 and PDE8 inhibition in in vitro enzyme assays. This compound also displays significant activity against PDE10A and PDE11A. BC8-15 elevates steroidogenesis in mouse Leydig cells as a single pharmacological agent. Assays using BC8-15 and two structural derivatives support a model in which PDE8 is a primary regulator of testosterone production by Leydig cells, with an additional role for PDE4 in this process. BC8-15, BC8-15A, and BC8-15C, which are commercially available compounds, display distinct patterns of activity against PDE4, PDE8, PDE10A, and PDE11A, representing a chemical toolkit that could be used to examine the biological roles of these enzymes in cell culture systems.
Imprinting for the assembly of artificial receptors on a silica surface

Molecular imprinting of a solid surface provides a means to introduce reactive functionalities with a defined geometry on the surface. A silica surface was imprinted with a tridentate metal complex, Ru[bipy–CHNCH2CH2CH2Si(OEt)3 ]3 . The molecular imprinting process leaves three amino groups per RuII complex. The imprinted silica was reacted with various aldehydes to assemble artificial receptor sites on the surface. A metal binding site for FeII was constructed with a bipyridine-modified aldehyde that was selectively adsorbed on the surface in the presence of other two aldehydes and FeII .
Fine Mapping of the Sequence Requirements for Binding of β-Lactamase Inhibitory Protein (BLIP) to TEM-1 β-Lactamase Using a Genetic Screen for BLIP Function

Beta-lactamase inhibitory protein (BLIP) binds and inhibits a diverse collection of class A beta-lactamases with a wide range of affinities. Alanine-scanning mutagenesis was previously performed to identify the amino acid sequence requirements of BLIP for binding the TEM-1, SME-1, SHV-1, and Bla1 beta-lactamases. Twenty-three BLIP residues that contact TEM-1 beta-lactamase in the structure of the complex were mutated to alanine and assayed for inhibition (K(i)) of beta-lactamase to identify two hotspots of binding energy. These studies have been extended by the development of a genetic screen for BLIP function in Escherichia coli. The bla(TEM-1) gene encoding TEM-1 beta-lactamase was inserted into the E. coli pyrF chromosomal locus. Expression of wild-type BLIP from a plasmid in this strain resulted in a large decrease in ampicillin resistance, while introduction of the same plasmid lacking BLIP had no effect on ampicillin resistance. In addition, it was found that when the BLIP alanine-scanning mutants were tested in the strain, the level of ampicillin resistance was proportional to the K(i) of the BLIP mutant. These results indicate that BLIP function can be monitored by the level of ampicillin resistance of the genetic test strain. Each of the 23 BLIP positions examined by alanine scanning was randomized to create libraries containing all possible substitutions at each position. The genetic screen for BLIP function was used to sort the libraries for active mutants, and DNA sequence analysis of functional BLIP mutants identified the sequences required for binding TEM-1 beta-lactamase. The results indicate the BLIP surface is tolerant of substitutions in that many contact positions can be substituted with other amino acid types and retain wild-type levels of function.
Ultrastructural localization of immunoreactivity in the developing piriform cortex

The purpose of this study was to determine the ultrastructural basis for the immunoreactivity patterns in synaptic structures during development in layers I and II of the piriform cortex (PC) of rats. Antisera to cholecystokinin (CCK) and glutamic acid decarboxylase (GAD) were used at several different postnatal days (PN) and in adults to describe the distribution, characteristics, and relative frequency of labeled profiles--especially axons and terminals--with emphasis on details of the synaptic contacts. GAD-positive terminals occur from PN 2 to adulthood but only form contacts in deeper sublayers (Ib and II) initially. Contacts increase in layer I after PN 6 and are reduced in layer II after PN 21 when the GAD-labeled terminals and synapses take on adult features with flattened vesicles and symmetric contacts. CCK-labeled terminals are present in deeper sublayers at PN 2 but are few and rarely form contacts. Both terminals and contacts increase between PN 2 and 9, taking on distinctive shapes and vesicle morphology by PN 13. At PN 21 and older, CCK terminals have mainly flattened vesicles and mostly form symmetric contacts onto dendrites and somata in deeper layers (Ib and II). Superficial sublayer Ia has very few CCK-labeled synapses and axons. Thus immunoreactivity occurs in terminals prior to synapse formation; labeling of the presynaptic specializations precedes subsequent maturation; synaptic vesicle morphology and membrane specializations are similar for the vast majority of both CCK and GAD terminals; inhibitory (GABA) synapses are established sooner than the possibly excitatory CCK synapses; a deep to superficial gradient of synaptogenesis is associated with GAD-positive terminals in the PC; and the labeling patterns may be related to critical developmental or synaptogenic periods.
139 THE ROLE OF HEART RATE AND AFTERLOAD ON CARDIAC OUTPUT IN NEWBORN LAMBS

Previous studies have suggested that increases in heart rate (HR) may represent the primary mechanism available to the newborn for increasing cardiac output (CO). In this study, we examined the independent effects of HR and afterload changes on CO in newborn lambs. Atrioventricular node ablation was performed in eight newborn lambs (3-10 days of age) by formalin injection, and the right ventricle was paced at a HR of 200 (baseline). Nine studies were performed in young lambs (less than 12 days of age), and nine studies in older lambs (greater than 12 days of age). CO/kg increased progressively with increasing HR. The maximum CO/kg attained was similar for both groups, but this was achieved at a higher HR in the younger lambs. From a baseline HR of 200, the maximum increase in CO/kg attained by increasing HR was 6.7% in the younger lambs, and 8.9% in the older lambs. At lower HR's (70/min), oxygen consumption (VO2) decreased, and systemic vascular resistance (SVR) increased. With a fixed HR of 200, nitroprusside caused an increase in CO/kg of 10.5% in the younger lambs, and 11.8% in the older lambs. Phenylephrine caused a decrease in CO/kg of 19.3% in the younger lambs, and 10.6% in the older lambs. HR above baseline has limited value in increasing CO in newborn lambs. At lower HR's, CO and VO2 fall, and SVR increases. Decreasing afterload produces modest increases in CO. Increasing afterload results in decreases in CO, and these changes were most striking in the younger lambs.
Surgical and anesthetic management of patients with mitochondrial dysfunction.

Abstract Mitochondrial diseases are primary defects in bio-energy metabolism. They are a heterogeneous group of diseases. The specific constellation of symptoms that will manifest in the effected individual depends on the type of genetic defect in the mitochondria. The goals of medical management, expressed in a highly simplified fashion, are to maintain a normal acid–base balance and to avoid those medical conditions and situations that add extra stress to a compromised bio-energy production system. Infection is a common stress that may cause a crisis in a patient with mitochondrial dysfunction. Treatment and avoidance of infections is a goal of both medical and surgical management. Common childhood illness such as otitis media, tonsillitis and sinusitis are example of such stress inducing infections.
Proton collisional excitation in the lowest lying 3P terms of ions in the Be and Mg isoelectronic sequences

Proton collisional excitation cross sections and rate constants are presented for transitions between the 3P(J) fine-structure levels of the lowest-lying sp configurations in a number of astrophysically important ions belonging to the Be and Mg isoelectronic sequences. The calculations were made by direct integration of the Schroedinger equation resulting from semiclassical Coulomb excitation theory. The cross sections and rate constants for the 3P(J) transitions in the lowest-lying P(2) configurations are expected to be similar to those for the corresponding sp configuration transitions, and this is illustrated for C III. For the high-temperature ion Ca XVII alpha particle excitation is shown to be unimportant for situations involving ordinary values of the He/H abundance ratio. A simple, but apparently accurate method for determining certain radial integrals for low-lying excited configurations is proposed.
DGGE fingerprinting of culturable soil bacterial communities complements culture-independent analyses

Culture-dependent DGGE (CD DGGE) fingerprinting of the 16S rRNA gene was used to characterize mixed bacterial communities recovered on agar plates. Using R2A Agar as a growth medium, CD DGGE analysis resulted in clear banding patterns of sufficient complexity (16–32 major bands) and reproducibility to investigate differences in bacterial communities in a silt loam soil. Replicate CD DGGE profiles from plates inoculated with less-dilute samples (10−3) had a higher band count and were more similar (72–77%) than profiles from more-dilute samples (51–61%). Different culture media and incubation conditions resulted in distinct community fingerprints and increased the cumulative number of unique bands detected. When CD DGGE fingerprints were compared to profiles constructed from 16S rRNA genes obtained from culture-independent clone libraries (CB DGGE profiles) 34% of the bands were unique to the culture-dependent profiles, 32% were unique to the culture-independent profiles and 34% were found in both communities. These data demonstrate that culture-independent DGGE profiles are supplemented by the distinct bands detected in culture-dependent profiles. CD DGGE can be a useful technique to follow the dynamics of distinct culturable fractions of the soil bacterial community.
Lipopolysaccharide Induces Early Tolerance to Excitotoxicity via Nitric Oxide and cGMP

Background and Purpose— Sublethal injury induces tolerance to a subsequent lethal insult, a phenomenon termed preconditioning (PC). PC occurs within hours (early tolerance) or days (delayed tolerance) after the inducing stimulus. In the brain, delayed tolerance has been studied extensively, but very little is known about early tolerance. We investigated whether the proinflammatory agent lipopolysaccharide (LPS), a well-established inducer of delayed tolerance, can also induce early tolerance and, if so, whether nitric oxide (NO) is involved in its mechanisms. Methods— In C57BL/6 mice, LPS was administered and N-methyl-d-aspartate (NMDA) was microinjected into the neocortex 30 minutes to 24 hours later. Lesion volume was assessed 24 hours after NMDA administration in thionine-stained sections. Results— LPS reduced NMDA lesions when administered 1 hour (−25±1%; P<0.05, n=5 per group) or 24 hours (−25±4%; P<0.05, n=5 per group) before NMDA application. LPS administration 30 minutes or 2 to 4 hours before NMD...
METHOD FOR OBTAINING KNOWN LOW CONCENTRATIONS OF MUSTARD (H) OR LEWISITE (L) GAS IN AIR

Constant small quantities (0.1 to 100 micrograms per hour) of mustard (H) or lewisite (L) gas may be obtained by allowing the vapor to diffuse through a porous alundum plug of suitable dimensions. By regulating the rate of flow of air past the plug known concentrations of the gases in air may be obtained.
Land waters and sea level

Changes in continental water stores, largely human-induced, affect sea level. Better hydrological models and observations could clarify the land's role in sea-level variations.
Mortality of Brook Trout, Mottled Sculpins, and Slimy Sculpins during Acidic Episodes

Abstract Brook trout Salvelinus fontinalis, mottled sculpins Cottus bairdi, and slimy sculpins Cottus cognatus occur in many Pennsylvania streams that have depressed pH and elevated aluminum concentrations during episodes of high stream discharge (acidic episodes). We performed 20-d in situ cage exposures with these species to determine their relative sensitivities to field conditions. We also exposed fish in the laboratory to synthetic soft water, without added Al, to elevate possible effects of Al on sodium flux rates and pH toxicity. Exposures were in five streams: Two with high pH (>5.60) and low Al concentrations (<80 μg/L) and three with low pH (usually between 5.0 and 5.5) and high Al levels (124–294 μg/L). Exposures were during two low-discharge fall periods, when pH tends to be seasonally higher and Al concentrations lower, and two relatively high-discharge spring seasons, when lower pH and higher Al concentrations are typical. Few fish died (generally < 10%) in the two streams that had higher pH...
Reclaiming SPSSI's Radical Promise: A Critical Look at JSI's “Impact of Welfare Reform” Issue

Studies of the impact of welfare reform reported in the Winter 2000 issue of JSI uniformly conclude that the results are mixed. Uncritically accepting the “official story” that success can be evaluated by the numbers of former welfare recipients who are working, the researchers, adopting a neutral “objective” perspective, focus on “barriers” to achieving this goal. We argue that this “honest broker” model, in which researchers provide “scientific” data to those in power, neglects the roles of social psychologists as social critics and political activists that were among the diverse perspectives among SPSSI's founders. We call for a rebirth of these more radical orientations and offer examples of research approaches that involve entering into alliances with oppressed groups in society. We hope our critique will stimulate wider discussion about SPSSI's future mission.
Performance Deviations in the Connected Speech of Adults With No Brain Damage and Adults With Aphasia

A rule-based system was used to score performance deviations in the connected speech of 40 adults with no brain damage, 10 adults with fluent aphasia, and 10 adults with nonfluent aphasia. Performa...
HIV-1 variation: consequences for disease progression and vaccine strategies

HIV-1 displays a high degree of biological heterogeneity in vitro, differing in tropism, kinetics of replication, cytopathogenicity, resistance to antiviral drugs and susceptibility to serum neutralization. Some of these properties can be linked to pathogenesis in the host. HIV variation is a major challenge to the development of effective vaccine or antiviral therapies.
The Impact of Rising CO2 on Ecosystem Production

A fundamental property of green plants is that the rate of photosynthesis is dependent in the ambient CO2 concentration. There is overwhelming experimental evidence that this effect increases plant production in most C3 plants: hundreds of experiments with many species show that plant growth increases an average 30% to 40% for a doubling of the present normal ambient CO2 concentration (Kimball, 1986). External environmental factors, such as temperature and the availability of nutrients, modify this response. The greatest stimulation of photosynthesis and growth can be expected to occur at high temperatures and much smaller responses at low temperature. Factors which restrict growth, such as low nutrients, will reduce but usually do not eliminate the stimulation of production with increasing CO2 even when nitrogen is severly limiting. There are also reports of direct effects of ambient CO2 concentration on dark respiration which show that there is an immediate reduction in the rate of CO2 efflux or O2 consumption when the CO2 around plant tissues is increased. There have been very few longterm field studies of the effects of increased CO2 on whole plants and ecosystem processes but the data from these studies are consistent in showing an increase in plant production with an increase in CO2 concentration of the ambient air.
Composing via Dictation and Speech Recognition Systems: Compensatory Technology for Students with Learning Disabilities.

This article provides a rationale for using an oral mode of production as a means of composing. For individuals with learning disabilities (LD), composing orally may allow them to circumvent transc...
Selecting a turn-key Geographic Information System using decision analysis

Abstract The organization attempting to purchase a turn-key Geographic Information System faces a difficult task. Many potential systems exist and none is clearly superior in all aspects. The organization must clearly define its needs and the trade off among these needs. A formal procedure exists, decision analysis, for making a selection within this multi-attribute problem. This procedure was used by Woodward-Clyde Consultants and is described here. As a side benefit, decision analysis is useful for identifying weak points in the selected system which might be addressed during contract negotiations.
Evidence that cobalt-carbon bond homolysis is coupled to hydrogen atom abstraction from substrate in methylmalonyl-CoA mutase.

Methylmalonyl-CoA mutase catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA. It is dependent on the cofactor, coenzyme B12 or adenosylcobalamin, for activity. The first step in this, ...
The role of PKC signaling in CRF-induced modulation of startle

Hypersignaling of corticotropin releasing factor (CRF) has been implicated in stress disorders; however, many of its downstream mechanisms of action remain unclear. In vitro, CRF1 receptor activation initiates multiple cell signaling cascades, including protein kinase A (PKA), protein kinase C (PKC), and mitogen-activated protein kinase kinase MEK1/2 signaling. It is unclear, however, which of these signaling cascades mediate CRF-induced behaviors during stress. We examined the role of PKA, PKC, and MEK1/2 signaling pathways in CRF-induced anxiety as measured by startle hyperreactivity. Mice treated with intracerbroventricular (ICV) ovine CRF (oCRF) were pretreated with the PKA inhibitor Rp-cAMPS, PKC inhibitor bisindolylmaleimide (BIM), or MEK1/2 inhibitor PD98059 (ICV) and assessed for acoustic startle reactivity. The PKC inhibitor BIM significantly attenuated CRF-induced increases in startle. BIM was also able to block startle increases induced by oCRF when both compounds were infused directly into the bed nucleus of stria terminalis (BNST). PKA and MEK1/2 inhibition had no significant effects on CRF-induced changes in startle at the dose ranges tested. CRF-induced disruption of prepulse inhibition was not significantly reversed by any of the three pretreatments at the dose ranges tested. PKC signaling is required for CRF-induced increases in startle, and this effect is mediated at least in part at the BNST. These findings suggest that PKC signaling cascades (1) may be important for the acute effects of CRF to induce startle hyperreactivity and (2) support further research of the role of PKC signaling in startle abnormalities relevant to disorders such as posttraumatic stress disorder.
Phenotypic Interactions among Mutations in a Thermus thermophilus 16S rRNA Gene Detected with Genetic Selections and Experimental Evolution

During protein synthesis, the ribosome undergoes conformational transitions between functional states, requiring communication between distant structural elements of the ribosome. Despite advances in ribosome structural biology, identifying the protein and rRNA residues governing these transitions remains a significant challenge. Such residues can potentially be identified genetically, given the predicted deleterious effects of mutations stabilizing the ribosome in discrete conformations and the expected ameliorating effects of second-site compensatory mutations. In this study, we employed genetic selections and experimental evolution to identify interacting mutations in the ribosome of the thermophilic bacterium Thermus thermophilus. By direct genetic selections, we identified mutations in 16S rRNA conferring a streptomycin dependence phenotype and from these derived second-site suppressor mutations relieving dependence. Using experimental evolution of streptomycin-independent pseudorevertants, we identified additional compensating mutations. Similar mutations could be evolved from slow-growing streptomycin-resistant mutants. While some mutations arose close to the site of the original mutation in the three-dimensional structure of the 30S ribosomal subunit and probably act directly by compensating for local structural distortions, the locations of others are consistent with long-range communication between specific structural elements within the ribosome.
Enkephalin mRNA production by cochlear and vestibular efferent neurons in the gerbil brainstem.

Preproenkephalin mRNA production by efferent neurons projecting to the gerbil inner ear was assessed using combined in situ hybridization and retrograde labeling with florescent tracers. Virtually all vestibular efferent neurons were positive for preproenkephalin mRNA. Of the cochlear efferents, one-half of the medial olivocochlear neurons were positive for enkephalin. All lateral olivocochlear neurons were negative for enkephalin. The results suggest that there are two, biochemically distinct subpopulations of medial olivocochlear efferents in the gerbil.
Trust in Children as a Function of Race, Sex, and Socio-Economic Group:

Trust was assessed for 880 school children employing a method in which the children might choose to aid or not to aid a young male E who was a stranger to them. Boys were more likely to trust E and blacks were less likely to trust a white E than were white children but even less likely to trust a black E. The results were interpreted in relation to urban crime statistics indicating that the victims of crime are poor and black and that the criminal is likely to be a young man.