cssi/SciSciGPT-SciSciNet huggingface dataset:
Persistent inefficiency : Adam Smith’s theory of slavery and its abolition in Western Europe

Adam Smith made two positive claims about slavery in the context of developing economies. First, Smith explains that slavery is in general highly inefficient. By his account, the net product under freedom is 12 times larger than under slavery. Second, he observes that, despite its inefficiencies, slavery persists in most of the world. Taken together, these claims create a fundamental puzzle: Why do elites – owning slaves and holding political control – fail to make themselves better off by freeing their slaves?Smith gives two very different answers to this puzzle. The first is psychological. Smith asserts that people have a fundamental desire to dominate others, and slavery provided that opportunity for slaveholding elites. The first explanation is the most commonly advanced in the literature. Yet no where else does Smith use the assumption of domination. This explanation therefore seems ad hoc.I favor instead Smith’s second explanation. This argument, far less known, involves commitment problems. Freeing the slaves would deprive slaveholders of their property. How would they be compensated? In principle, a long-term compensation scheme could solve this problem. But in the undeveloped societies Smith discusses, such as feudal Europe, long-term contracts were difficult to enforce. Indeed, I show that both parties to the long-term compensation scheme had incentives to dishonor it. In the presence of commitment problems, masters could not be assured they would, in fact, be better off freeing their slaves. Slaveholders therefore rationally avoided emancipation despite its inefficiency.
Visions of the middle landscape: Organic farming and the politics of nature

The proposed federal regulation oforganic agriculture in the United States raisesquestions both about the nature and character oforganic farming, as well as its relation to theagro-food system at large. The regulatory process hasengendered a public debate about conventional andalternative approaches to agricultural production,which in turn raises issues of environmental politicsand society-nature relations. An analysis oftranscripts from public hearings, organic farmingmovement literature, and interviews with organicpractitioners and advocates reveals the broaderecological, social, and political ramifications. Inexamining the proposed federal rule and its criticalopposition, we encounter two different worldviews; twoconflicting visions of agriculture, rural life, andnature itself. Whether this is a fundamental impasse,or a controversy that can be fruitfully resolved,remains an open question. But organic farming hasarrived at a critical juncture, both fraught withperil, and full of opportunity. The enormous publicresponse to this issue indicates the renewed potentialon the part of civil society to participate ingrassroots environmental social movements in supportof alternative agriculture.
HIV/AIDS, Health Services Utilization among People Living with

An estimated 34 million people in the world are living with human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS). The majority of people living with HIV/AIDS (PLWHA) reside in developing countries. High-risk HIV populations include commercial sex workers, patients being treated for sexually transmitted diseases (STDs) or tuberculosis, injection drug users, pregnant women, and blood donors. The treatment of HIV/AIDS is challenging. There is no cure; available therapies – principally, antiretroviral therapy (ART) – can only suppress the viral load to reduce the risk of disease progression and to prevent transmission to others. Access to ART has improved significantly, but nearly half of PLWHAs are still not receiving life-saving treatment, and only 10 low- and middle-income countries have achieved universal (80 percent) access. Several barriers to HIV/AIDS treatments have been noted; for example, many PLWHAs are not accessing ART because they are unaware of their HIV status. Research shows that bringing services closer to where people live improves access and utilization. Scaling up HIV services for special populations, such as men who have sex with men (MSMs), injection drug users, and youth, is essential for curbing the HIV/AIDS epidemics. Keywords: AIDS ; health behavior; health care
Microsoft Cambridge at TREC-10: Filtering and Web Tracks.

This report is concerned with the Adaptive Filtering and Web tracks. There are separate reports in this volume [1, 2] on the Microsoft Research Redmond participation in QA track and the Microsoft Research Beijing participation in the Web track.. Two runs were submitted for the Adaptive Filtering track, on the adaptive filtering task only (two optimisation measures), and several runs for the Web track, both tasks (adhoc and home page finding). The filtering system is somewhat similar to the one used for TREC–9; the web system is a simple Okapi system without blind feedback, but the document indexing includes anchor text from incoming links.
Chapter 2 Emotional circuits of the mammalian brain: Implications for biological psychiatry

Summary Evidence for basic brain systems that mediate affective-emotional processes is summarized. The key to understanding the fundamental sources of human emotions lies in unraveling the nature of a variety of subcortical neurochemical circuits that mediate spontaneous emotional behaviors in animals: freezing and flight (for fear), separation distress vocalizations (for grief), fighting and biting (for anger), rough-and-tumble play (for joy), and appetitive approach and other anticipatory behaviors (for interest/expectancy). There are also basic brain circuits that generate various affective experiences, including male and female sexuality, dominance, and perhaps greed. These systems are modulated by a variety of nonspecific neurochemical systems, including acetylcholine, dopamine, norepinephrine, and serotonin, which control arousal and attention. The arousal of specific emotions appears to be related more to discrete neuropeptide systems. Just as a detailed understanding of the former circuits served as a foundational pillar for the biological psychiatry of the past, new knowledge of how neuropeptide systems arouse distinct emotions will be a pillar for the biological psychiatry of the future.
Burnout, Psychology of

This article is a revision of the previous edition article by C. Maslach, volume 2, pp. 1415–1418, © 2001, Elsevier Ltd.
Sequential point estimation for branching processes i, subcritical case

For a subcritical branching process with observable immigration, we consider the problem of finding a sample size for which the mean squared error of a natural estimator of the offspring mean is less than a prescribed value u. If the parameters of the process are known, then a minimum sample size achieving the above objective (approximately) exists. When the parameters are unknown, we propose a stopping rule and show that the resulting sequential procedure is asymptotically risk efficient as u approaches zero. Furthermore, we establish the asymptotic efficiency and normality of our stopping rule.
Simultaneous recording of intramembrane charge movement components and calcium release in wild-type and S100A1−/− muscle fibres

In the preceding paper, we reported that flexor digitorum brevis (FDB) muscle fibres from S100A1 knock-out (KO) mice exhibit a selective suppression of the delayed, steeply voltage-dependent component of intra-membrane charge movement current termed Qγ. Here, we use 50 μm of the Ca2+ indicator fluo-4 in the whole cell patch clamp pipette, in addition to 20 mm EGTA and other constituents included for the charge movement studies, and calculate the SR Ca2+ release flux from the fluo-4 signals during voltage clamp depolarizations. Ca2+ release flux is decreased in amplitude by the same fraction at all voltages in fibres from S100A1 KO mice compared to fibres from wild-type (WT) littermates, but unchanged in time course at each pulse membrane potential. There is a strong correlation between the time course and magnitude of release flux and the development of Qγ. The decreased Ca2+ release in KO fibres is likely to account for the suppression of Qγ in these fibres. Consistent with this interpretation, 4-chloro-m-cresol (4–CMC; 100 μm) increases the rate of Ca2+ release and restores Qγ at intermediate depolarizations in fibres from KO mice, but does not increase Ca2+ release or restore Qγ at large depolarizations. Our findings are consistent with similar activation kinetics for SR Ca2+ channels in both WT and KO fibres, but decreased Ca2+ release in the KO fibres possibly due to shorter SR channel open times. The decreased Ca2+ release at each voltage is insufficient to activate Qγ in fibres lacking S100A1.
Dyson-Index-Like Behavior of Bures Separability Functions

We conduct a study based on the Bures (minimal monotone) metric, analogous to that recently reported for the Hilbert-Schmidt (flat or Euclidean) metric (arXiv:0704.3723v2). Among the interesting results obtained there had been proportionalities—in exact correspondence to the Dyson indices � = 1,2,4 of random matrix theory—between the fourth, second and first powers of the separability functions Stype(µ) for real, complex and quaternionic qubit-qubit scenarios, Here µ = q �11�44
Network forensics analysis using Wireshark

The number and types of attacks against networked computer systems have raised the importance of network security. Today, network administrators need to be able to investigate and analyse the network traffic to understand what is happening and to deploy immediate response in case of an identified attack. Wireshark proves to be an effective open source tool in the study of network packets and their behaviour. In this regard, Wireshark can be used in identifying and categorising various types of attack signatures. The purpose of this paper is to demonstrate how Wireshark is applied in network protocol diagnosis and can be used to discover traditional network attacks such as port scanning, covert FTP and IRC channels, ICMP-based attacks, BitTorrent-driven denial service, and etc. In addition, the case studies in this paper illustrate the idea of using Wireshark to identify new attack vectors.
The price of evolution in incremental network design: The case of mesh networks

In practice most service-provider and enterprise networks are designed incrementally over time. This ongoing and heuristic design process is driven by changes in the underlying objectives and constraints (the “environment”). We first formulate the incremental network design approach as the constrained minimization of a certain modification cost, and compare that with the classical design approach in which the objective is to minimize the total network cost. We evaluate the cost overhead and the evolvability of incremental designs under two network expansion models (random and gradual), evaluating incrementally designed networks in terms of cost, performance (propagation delay) and robustness. Even though incremental design has some cost overhead, this overhead does not increase as the network grows. In the case of mesh networks, the incremental design process leads to networks with larger link density, lower average delay and improved robustness.
Leverage, System Risk and Financial System Health: How Do We Develop a Healthy Financial System?

The subprime crisis of 2007–2009 was the most devastating financial crisis since the Great Depression, cost the US economy trillions of dollars (see Atkinson, Luttrell and Rosenblum, 2013) and caused significant economic stress worldwide.1 In response, new financial-market regulations were adopted in many countries, including the Dodd-Frank Act in the US, which is a massively complex piece of legislation that touches most financial intermediaries in significant ways and imposes a host of new proscriptions and requirements on all sorts of intermediaries. Moreover, the crisis also required unprecedented government intervention in the financial market and the real economy, with the issuance of ex post guarantees against failure to a multitude of a priori uninsured investors and institutions, in order to stave off a complete collapse of the financial system. While there is much debate over whether the regulatory interventions were the appropriate ones (see Lo (2012), and Thakor (2013b) for detailed discussions), these interventions raise concerns about potential moral hazard insofar as expectations of future bailouts may influence present behaviour, and greater political involvement in the functioning of credit markets (see Song and Thakor, 2012).
Germany's reconciliation with its Eastern Neighbours

With the collapse of the Berlin Wall Germany became a unified country. While’ the significance of this event is well recognised, one consequence generally over‐looked has been Germany's increasing reconciliation with her former Communist, neighbours Poland and the Czech and Slovak republics. This significantly marks the closening of ties of former Communist states with Western Europe, looking for‐ward to fuller integration into the European Union and NATO. Dr Latawski concludes that the cementing of relationships between these historically troubled countries signals a significant benchmark in the post‐Cold War development of a united Europe.
Quantitative LSPR Imaging for Biosensing with Single Nanostructure Resolution

Localized surface plasmon resonance (LSPR) imaging has the potential to map complex spatio-temporal variations in analyte concentration, such as those produced by protein secretions from live cells. A fundamental roadblock to the realization of such applications is the challenge of calibrating a nanoscale sensor for quantitative analysis. Here, we introduce a new, to our knowledge, LSPR imaging and analysis technique that enables the calibration of hundreds of individual gold nanostructures in parallel. The calibration allowed us to map the fractional occupancy of surface-bound receptors at individual nanostructures with nanomolar sensitivity and a temporal resolution of 225 ms. As a demonstration of the technique’s applicability to molecular and cell biology, the calibrated array was used for the quantitative LSPR imaging of anti-c-myc antibodies harvested from a cultured 9E10 hybridoma cell line without the need for further purification or processing.
The role of the time allowed for mating on variability of fetal weight in rats.

In rats variation of fetal weights among litters is significantly greater than variation of fetal weights within litters. This phenomenon is called the litter effect. Twenty litters of Wistar rats were studied to determine whether or not variation in the duration of the period allowed for copulation (1.5 hours versus 15 hours) was a cause of the litter effect. Analyses of variance showed that the duration of the mating period did not significantly influence mean fetal weight, intralitter variability, or interlitter variability. It is concluded that the use of a restricted mating period as opposed to the commonly used overnight mating period offers no advantage from the standpoint of fetal weight variability. The need to consider the sample size of both litters and fetuses in teratologic and fetal growth studies is stressed.
Iron, the substantia nigra and related neurological disorders.

Abstract Background Iron status is higher in the substantia nigra than in other brain regions but can fluctuate as function of diet and genetics and disease. Of particular note is the compartmentalization of the iron-enrichment in this region; the pars reticulata contains higher levels of stainable iron as compared to the pars compacta. The latter area is where the dopaminergic neurons reside. How this compartmentalization impacts the interpretation of data that iron contributes to cell death as in Parkinson's disease or iron deficiency contributes to altered dopaminergic activity is unknown. Nonetheless, that iron can influence neuronal cell death and dopamine function is clear. Methods The mechanisms by which iron may be managed in the substantia nigra, particularly in the neuromelanin cells where minimal levels of ferritin the iron storage protein have been detected are addressed. The current approaches to detect iron in the substantia nigra are also reviewed. In addition, the potential mechanisms by which iron enrichment may occur in the substantia nigra are explored. General Significance This review attempts to provide a critical evaluation of the many avenues of exploration into the role of iron in one of the most iron-enriched and clinically investigated areas of the brain, the substantia nigra.
Stretch‐sensitive channels in developing muscle cells from a mouse cell line.

1. Recordings of single-channel activity were made from cell-attached patches on mouse C2 muscle cells at morphologically identifiable stages of myogenesis in vitro. We have identified Ca2(+)-permeable, cation-selective channels that are gated by applying suction to the patch electrode and by changes in membrane potential and have analysed single-channel properties as well as channel expression during myogenesis. 2. Single-channel activity could be detected when the membrane was held at steady negative potentials. With monovalent cations in the electrode, the single-channel current-voltage (i-V) relations were linear. The channel is permeable to Li+, Na+, K+, Rb+ and Cs+, but is not strongly selective among the monovalent cations as judged by measurements of single-channel conductance and reversal potential. 3. With 110 mM of either CaCl2 or BaCl2 as the only inward change carrier, slope conductances were approximately 13 and 24 pS and currents reversed at approximately +22 and +17 mV, respectively. The relative permeability of Ca2+ to K+ calculated from the constant-field equation was PCa/PK = approximately 2. 4. Channel openings occurred as bursts of brief openings and closings separated by much longer closed periods. Closed-time histograms were best fitted with three exponential components, while histograms of burst duration were best fitted with two exponential components, reflecting the short and long bursts in the single-channel records. 5. Applying suction to the patch electrode while recording at steady negative membrane potentials produced channel openings to discrete current levels. Mean channel open probability depended linearly on the square of the applied pressure and was greater at positive membrane potentials. The permeability of the channel to monovalent and divalent cations was indistinguishable from the spontaneous activity recorded at steady negative potentials. 6. Channel activity recorded from cell-attached patches in the absence of applied pressure depended on membrane potential increasing approximately e-fold per 38 mV with depolarization. Analysis of the kinetics of the response to membrane potential showed that the depolarization reduced the duration of the slowest component of the closed-time distribution. 7. The lanthanide cation gadolinium (Gd) reduced the amplitude of the unitary currents in a concentration-dependent manner. The amplitudes of both inward and outward currents were reduced to the same extent suggesting block is voltage-independent. Gd produced half-maximal inhibition of the unitary current at approximately 6 microM.(ABSTRACT TRUNCATED AT 400 WORDS)
Beyond Borders: Reading "Other" Places in Children's Literature.

The author analyzes two texts, Gloria Whelan’s Homeless Bird and Deborah Ellis’s Parvana’s Journey, in an attempt to explain some of the problems and difficulties associated with those texts. The author examines Whelan’s representations of India and finds troubling binaries associated with that text. In comparison, the author finds Ellis’s depictions of Afghanistan more nuanced and complex. The author also discusses student reception of both texts and offers ways to problematize some of their reactions.
A clinical pharmacological study of subcutaneous nicotine

The stable isotope-labeled compound 3',-3'-dideuteronicotine (nicotine-d2) was used to investigate the disposition kinetics and effects of nicotine administered subcutaneously to 6 smokers. Plasma nicotine-d2 concentrations were measured for 8 h after subcutaneous injection of 4 doses (0.4, 0.8, 1.2, and 2.4 mg). Peak plasma nicotine concentration correlated well with the dose, averaging 2.8 to 14.8 ng/ml, 19 to 25 min after injection of the 0.4 mg and 2.4 mg doses, respectively. The plasma clearance over bioavailability ratio (CL/f) averaged 12 to 13 ml · min−1 · kg−1, similar to the clearance reported previously for intravenously administered nicotine. Thus, bioavailability appears to be approximately 100%. The heart rate response was more sensitive to the nicotine dose than the blood pressure response. Subjective effects showed large interindividual variability. The results reported herein may be useful in planning future studies. Administration of nicotine by the subcutaneous route appears to be a practical and safe method for studying the human pharmacology of nicotine.
Solid-phase synthesis of oligosaccharides and on-resin quantitative monitoring using gated decoupling 13C NMR

A general strategy for solid-phase oligosaccharide synthesis capable of nondestructive quantitative monitoring has been developed. The synthesis was carried out on TentaGel using thioglycosides as glycosylating agents and dimethylthiomethylsulfonium triflate as the activator. An acylsulfonamide linker was introduced to cleave the oligosaccharide from the resin. The solid-phase reactions were monitored quantitatively by using the inverse gated decoupling technique of 13C NMR, where two 13C-enriched markers were used to monitor the reactions: one was 13C-enriched glycine incorporated as a part of the linker and as an internal standard, and the other was a 13C-enriched acetyl group used as a protecting group of the glycosylation reagent. A representative synthesis of sialyl Lewis X branched tetrasaccharide was demonstrated.
Inductive Neural Stimulator

A device has been designed and constructed to cause stimulation of neural tissue by means of an induced electric field. Such a device is interesting because it allows a neural structure to be stimulated without requiring either the surgical exposure of the site of stimulation or requiring that current be passed from the outside to the inside of the living system. Tests have been conducted at stimulation rates of 45 pulses per second (pps) but the system can be adapted to provide rates up to 125 pps.
Ligand-independent activation domain in the N terminus of peroxisome proliferator-activated receptor gamma (PPARgamma). Differential activity of PPARgamma1 and -2 isoforms and influence of insulin.

Peroxisome proliferator-activated receptor γ (PPARγ) is a member of the nuclear hormone receptor superfamily, and is an important regulator of adipogenesis and adipocyte gene expression. PPARγ exists as two isoforms, PPARγ1 and PPARγ2, that differ only in their N termini. Both isoforms are activated by ligands that include the antidiabetic thiazoladinedione drugs and 15-deoxy-Δ12, 14-prostaglandin J2, and potential differences in their function have yet to be described. We report that, in addition to a ligand-activated transcriptional activity, when studied under conditions of ligand depletion, intact PPARγ has a ligand-independent activation domain. To identify the basis for this ligand-independent activation, we used GAL4-PPARγ chimeric expression constructs and UAS-TK-LUC in CV1 cells and isolated rat adipocytes. In both cell systems, isolated PPARγ1 and PPARγ2 N termini have activation domains, and the activation function of PPARγ2 is 5–6-fold greater than that of PPARγ1. Insulin enhances the transcriptional effect mediated by both PPARγ1 and PPARγ2 N-terminal domains. These data demonstrate that 1) PPARγ has an N-terminal (ligand-independent) activation domain; 2) PPARγ1 and PPARγ2 N termini have distinct activation capacities; and 3) insulin can potentiate the activity of the N-terminal domain of PPARγ.
Flattening of distinctions in a Parkinsonian signer

Abstract The analysis of motor deficits in Parkinsonian signing provides an important new vehicle for understanding the ongoing interplay between linguistic intelligibility and processes that ease articulation. Field-by-field video analysis was performed on two elicited narratives from a 72-year-old, congenitally deaf, Parkinsonian signer. This analysis revealed that although the overall topography of the signing space was maintained, preserving movement contours and trajectories, the actual sign articulations were miniaturized and laxed. At times the non-dominant left hand shadowed the handshape of the dominant right, or two consecutive signs were blended into a single portmanteau form. Moreover, within utterances there was an abnormally uniform rhythmic pattern. While the Parkinsonian signer reduced amplitude, crispness, and rhythmic variation, he stopped short of obliterating linguistically relevant distinctions, which implies that an intact linguistic system was clamped by a more general motor deficit.
A comparison of several tests for drug synergy

Statistical approaches for assessment of synergism have been widely used in pharmacological settings to identify beneficial drug combinations. Several commonly used approaches for synergy assessment are studied in this paper. Each of the methods studied can be related to the isobole-based definition of additivity (Berenbaum, 1989). A Monte Carlo study is conducted in which both significance levels and powers for the five methods are estimated and compared. Based on the results from the simulation study, two approaches due to Finney (1971b) perform similarly, with high power and acceptable significance levels. In addition, a global overall test of synergism from the modified Kelly and Rice (1990) method for larger sample sizes and an approach due to Carter et al. (1988) perform well in terms of estimated Type I error rate.
MEASUREMENTS OF THE ELECTRON IMPACT EXCITATION CROSS SECTION OF N$sub 2$$sup +$ FIRST NEGATIVE BANDS.

Emission cross sections for the ${{N}_{2}}^{+}$ first negative bands produced by electron impact on ${\mathrm{N}}_{2}$ have been measured using a photon counting technique in the energy range 70 eV to 4 keV. The maximum cross section for the ${v}^{\ensuremath{'}}=0$ vibrational level of the $B ^{2}{\ensuremath{\Sigma}}_{u}^{+}$ excited state of $\mathrm{N}_{2}^{+}$ is 2.38 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}17}$ ${\mathrm{cm}}^{2}$. The ratio of cross sections for the (0, 0), (0, 1) and (0, 2) bands of first negative system is 1: 0.34: 0.065. The total emission cross section for the ${v}^{\ensuremath{'}}=0$ vibrational level accounts for 10% of the total ionization cross section of ${\mathrm{N}}_{2}$.
BRANCHING PATTERNS OF COLUMNAR CACTI: INFLUENCES ON PAR INTERCEPTION AND CO2 UPTAKE'

Field measurements and a computer model were used to determine how stem shape and arrangement of stems in space affect interception of photosynthetically active radiation (PAR) and CO2 uptake under otherwise optimal conditions for four species ofcolumnar cacti (Carnegiea gigantea, Lophocereus schottii, Pachycereus pringlei, and Stenocereus thurberi). In simulations where the number of widely spaced stems was increased from 1 to 19 but plant volume remained constant, surface area and PAR interception increased, leading to 3-fold increases in wholeplant CO2 uptake. Increasing the distance between stems from 0 cm to infinity decreased selfshading and increased predicted CO2 uptake 4-fold. Stem length, diam, ribbing characteristics, and spine coverage also influenced PAR interception. The model indicated that the observed higher frequency of branches on the south side of the trunk of C. gigantea had only a slight, though positive, effect on CO2 uptake for single-branched plants. Because of its greater surface area (A), a five-stemmed plant of C. gigantea typical for a field site near Tucson, Arizona was predicted to have 52% more CO2 uptake than a single-stemmed plant of the same volume (V). Although large A/V decreases water storage per unit transpiring area, whole-plant CO2 uptake can be increased when A/V is increased by branching for these constant-volume plants. However, the stems must be arranged to avoid excessive self-shading and thus keep the area below PAR compensation small.
Using Acceptance and Commitment Therapy during Methadone Dose Reduction: Rationale, Treatment Description, and a Case Report

Abstract Many clients who undergo methadone maintenance (MM) treatment for heroin and other opiate dependence prefer abstinence from methadone. Attempts at methadone detoxification are often unsuccessful, however, due to distressing physical as well as psychological symptoms. Outcomes from an MM client who voluntarily participated in an Acceptance and Commitment Therapy (ACT)–based methadone detoxification program are presented. The program consisted of a 1-month stabilization and 5-month gradual methadone dose reduction period, combined with weekly individual ACT sessions. Urine samples were collected twice weekly to assess for use of illicit drugs. The participant successfully completed the program and had favorable drug use outcomes during the course of treatment, and at the 1-month and 1-year follow-ups. Innovative behavior therapies, such as ACT, that focus on acceptance of the inevitable distress associated with opiate withdrawal may improve methadone detoxification outcomes.
High Performance Tangential Flow Filtration Using Charged Affinity Ligands

Abstract High performance tangential flow filtration is an emerging technology for protein separations. The objective of this work was to examine the use of small charged affinity ligands to control the protein charge and thus extend the potential applicability of this separation technique. Experiments were performed using binary mixtures of bovine serum albumin and ovalbumin, with Cibacron Blue added as an affinity ligand. The addition of Cibacron Blue caused a large increase in the selectivity due to the increase in BSA retention associated with the strong electrostatic repulsion between the negatively‐charged protein‐ligand complex and the negatively‐charged cellulosic membrane. Appropriate conditions for the separation were identified using total recycle experiments in a small‐scale tangential flow filtration device. A diafiltration process was designed to separate BSA from ovalbumin, with the Cibacron Blue recovered in a second stage operated with a buffer containing NaSCN to displace the dye from th...
The factors influencing coordination numbers in solids

Abstract An empirical plot of average principal quantum number ( n ) versus average AX electronegativity difference (Δχ) for AnXm structures shows resolution of four-, six-, and eight-coordinate solid state structures (Pearson diagrams). A simple molecular orbital (and therefore covalent) analysis of the coordination number problem suggests that it is determined by the balance between X-X nonbonded repulsions and the number of stabilizing interactions (both of which increase with coordination number). A-A repulsions may also be important if A is significantly larger than X. The approach provides an alternative to the ionic model for structure rationalization but it is still not clear how relatively important covalent and ionic factors are in determining the structures of even “ionic” solids.
Developmental Exposure to Aroclor 1254 Produces Low-Frequency Alterations in Adult Rat Brainstem Auditory Evoked Responses,

Abstract Developmental exposure of Long–Evans rats to 0, 1, 4, or 8 mg/kg/day Aroclor 1254 (A1254) from Gestational Day 6 through Postnatal Day 21 produces an elevated behavioral threshold for a 1-kHz tone. Brainstem auditory evoked responses (BAERs) were assessed in a subset of these animals (about 1 year old) using filtered clicks at 1 (65 and 80 dB SPL), 4 (60 and 80 dB SPL), 16 (40 and 80 dB SPL), and 32 (40 and 80 dB SPL) kHz. Aroclor 1254 decreased BAER amplitudes at 1 and 4 kHz, but not at 16 or 32 kHz. A dose-related decrease in the baseline-to-peak P1Aamplitude was observed for the 1-kHz (80-dB) stimulus. Doses of 1, 4, or 8 mg/kg/day A1254 decreased the peak-to-peak amplitude of both P1AN1and P1BN1for a 1-kHz (80-dB) stimulus. Doses of 4 and 8 mg/kg/day A1254 decreased the peak-to-peak amplitude of N1P2and P2N2for a 4-kHz (60-dB) or 1-kHz (80-dB) stimulus. At 8 mg/kg/day, A1254 also increased the latency of peak P4at 1 kHz (65 dB). The decreases in peak P1Aamplitudes are consistent with a dysfunction of the cochlea and/or auditory nerve. Together, the data confirm that developmental exposure of rats to A1254 produces a permanent low- to mid-frequency auditory dysfunction and suggest a cochlear and/or auditory nerve site of action.
Clinical issues in the management of early lung cancer.

Lung cancer is commonly diagnosed after metastatic spread, when therapies are rarely curative, providing an impetus for continued research directed at exploring approaches for cost-effective early lung cancer detection. Recently published pilot studies across three continents support a benefit of spiral computed tomography (CT) in detecting earlier stage non–small cell lung cancer. Improved resolution of early lung cancer is a result of significant changes in CT imaging hardware and software. The status and implications of these developments are reviewed. Many aspects of the management of screening for early lung cancer could be informed by optimizing the downstream clinical management of potential lung cancers identified by CT screening. The first and most critical issue is whether or not this improved detection rate is clearly associated with a reduction in lung cancer–related mortality. However, other related issues such as cost-benefit evaluations are also considered. If smaller, truly localized primary cancer can be routinely detected, then options for less morbid interventions would also be desirable. The rapid improvement in resolution and cost of spiral CT has provided a powerful impetus to reconsider the possibilities for achieving safe, economical, and meaningful early lung cancer detection.
Intractable hiccups resolved after resection of a cavernous malformation of the medulla oblongata.

Hiccups are reflexive involuntary contractions of the respiatory muscles followed very early by sudden closure of the lottis. While common in the fetal stages of life they are usually enign, short-lived, self-limited and very commonly overlooked in dults. Rarely, hiccups can indicate significant neurologic disease 1]. Here, we present a case of a patient presenting with 3 years f intractable hiccups and a single medullary cavernous malforation whose symptoms resolved after resection of the lesion. We hen discuss the available literature for medullary cavernomas preenting with hiccups and how surgical resection relieves symptoms ikely by compromising the vagal activity.
The determination of the uptake of arabinosyl-6-mercaptopurine by L1210 cells

Abstract 1. 1. The uptake of arabinosyl-6-mercaptopurine was studied in vitro in L1210 cells and in an arabinosyl-6-mercaptopurine-resistant subline. There was little or no difference in the rate of uptake, Km and V values between the two cell lines. This strengthens the conclusion that the arabinosyl-6-mercaptopurine-resistant subline of L1210 cells is due to an insensitive ribonucleotide reductase and not due to an impairment in the capacity for arabinosyl-6-mercaptopurine accumulation. 2. 2. A new technique is described for the rapid separation of cells from the reaction medium by centrifugation through silicone oil. This permitted the measurement of actual rates of antimetabolite or nucleoside movement in cells. 3. 3. The water-permeable space was estimated to be 208 μl per 109 cells, since there was little or no detectable [carboxyl-14C]inulin in the cell pellet.
(Trimethylsilylmethyl)tributyltin: A convenient in situ precursor of trimethylsilylmethyllithium

Abstract The transmetalation reaction between (trimethylsilylmethyl)tributyltin and n -butyllithium proceeds in quantitative yield at 0°C in a mixture of tetrahydrofuran and hexane to afford trimethylsilylmethyllithium and tetrabutyltin. The methylenation of aldehydes and ketones utilizing this in situ procedure is demonstrated.
New Record of Asiatic Clam in Colorado

Abstract The Asiatic clam (Corbicula fluminea Muller) was found in Arapahoe County, Colorado. This is the first record of this exotic clam from the state of Colorado.
Cloning and characterization of avfA and omtB genes involved in aflatoxin biosynthesis in three Aspergillus species.

Abstract The biosynthesis of aflatoxins (B1, G1, B2, and G2) is a multi-enzyme process controlled genetically by over 20 genes. In this study, we report the identification and characterization of the avfA gene, which was found to be involved in the conversion of averufin (AVF) to versiconal hemiacetal acetate (VHA), in Aspergillus parasiticus and A. flavus; a copy of avfA gene was also cloned from a non-aflatoxin producing strain A. sojae. Complementation of an averufin-accumulating, non-aflatoxigenic mutant strain of A. parasiticus, SRRC 165, with the avfA gene cloned from A. flavus, restored the ability of the mutant to convert AVF to VHA and to produce aflatoxins B1, G1, B2, and G2. Sequence analysis revealed that a single amino acid replacement from aspartic acid to asparagine disabled the function of the enzyme in the mutant strain SRRC 165. The A. parasiticus avfA was identified to be a homolog of previously sequenced, but functionally unassigned transcript, stcO, in A. nidulans based on sequence homology at both nucleotide (57%) and amino acid (55%) levels. In addition to avfA, another aflatoxin pathway gene, omtB, encoding for an O-methyltransferase involved in the conversion of demethylsterigmatocystin (DMST) to sterigmatocystin (ST) and dihydrodemethylsterigmatocystin (DHDMST) to dihydrosterigmatocystin (DHST), was cloned from A. parasiticus, A. flavus, and A. sojae. The omtB gene was found to be highly homologous to stcP from A. nidulans, which has been reported earlier to be involved in a similar enzymatic step for the sterigmatocystin formation in that species. RT-PCR data demonstrated that both the avfA and avfA1 as well as omtB genes in A. parasiticus were expressed only in the aflatoxin-conducive medium. An analysis of the degrees of homology for the two reported genes between the Aspergillus species A. parasiticus, A. flavus, A. nidulans and A. sojae was conducted.
Autoantibodies against platelet GPIIb/IIIa in chronic ITP react with different epitopes.

Summary Some patients with chronic immune thrombocytopenic purpura have autoantibodies to the platelet glycoprotein IIb/IIIa (GPIIb/IIIa) complex. To determine whether these autoantibodies are directed towards the same or different epitopes, we evaluated the ability of four murine monoclonal anti-GPIIb/IIIa antibodies specific for different epitopes to block autoantibody binding. We noted a variation in blocking patterns among autoantibodies from patients with chronic ITP. In addition, we were able to map the relative epitope locations of both the autoantibodies and the monoclonal antibodies. These data show that the anti-GPIIb/IIIa monoclonal autoantibodies in chronic ITP are directed towards different epitopes.
Torsional Steering Controls the Stereoselectivity of Epoxidation in the Guanacastepene A Synthesis

The stereoselectivity of the key epoxidation step in the synthesis of guanacastepene A is shown to be controlled by torsional steering. In this particular epoxidation reaction, the transition structure energetic difference is enhanced by the great asynchronicity of the forming C−O bonds that intensifies the torsional interactions.
Zero placement for designing discrete-time repetitive controllers

Abstract The analysis and design of two discrete-time repetitive control methods using root locus techniques are presented. These methods are theoretically capable of perfect cancellation of all harmonics of a periodic disturbance up to the Nyquist frequency while remaining robust to a class of unmodeled dynamics. They are designed to be stable in the presence of an unmodeled pole on the real axis inside the unit circle. The robustness results are achieved by adding zeros to the dynamics of the compensators.
Unequal-length multichannel /spl delta//sub b/-Levinson and Schur type RLS algorithms

In this correspondence, /spl delta//sub b/-operator-based unequal-length multichannel Levinson and Schur-type RLS algorithms are developed which have the potential of improved numerical behavior for fast-sampled or ill-conditioned input data. They provide computational improvement over the overparameterization, or the zero padding approach using the existing equal-length multichannel /spl delta//sub b/ algorithms when an unequal length multichannel case is considered. >
A computer-controlled system for post-stimulus time histogram and wind-up studies

A LabVIEW 2 virtual instrument (VI)-based system is described for stimulation of sensory fibers in peripheral nerves and analysis and storage of electrophysiological data recorded from the spinal cord. The system utilizes a commercially available multifunction data acquisition (input/output; I/O) board, graphical programming environment and custom built VIs. Electrical stimuli are triggered by the I/O board and delivered at C-fiber strength to the receptive field of a multireceptive dorsal horn neuron. The stimulus frequency can be chosen between 0.1 and 1 Hz. Extracellular action potentials are recorded with a compound recording/iontophoresis carbon-fiber microelectrode and sampled by the I/O board. Post-stimulus time histograms (PSTH) are computed to visualize the preferred times of neuronal firing evoked by A- and C-fiber inputs. Responses of the neuron to repetitive stimulation are analyzed by their latency relative to the stimulus and plotted against the stimulus number. Wind-up, the progressive potentiation of C fiber-evoked response per stimulus, is increased by NMDA and decreased by MK-801 when each is applied by microiontophoresis. The system is well suited to perform combined PSTH and wind-up analysis on-line as well as to examine previously recorded data off-line. Principles of operation and diagrams of greater importance are explained in detail. To illustrate system operation, sample recordings, PSTH and wind-up analyses from a dorsal horn neuron are presented. The software is available from the author.
A Work-Centered Approach for Setting Passing Scores on Performance-Based Assessments

Standardized patient examinations are being used for high-stakes decisions (e.g., graduation, licensure, and certification) with growing frequency. Concurrently, research on methods to determine the passing score for these types of performance-based assessments has increased. A wide variety of approaches have been considered in the past several years, many based on traditional techniques developed for use with multiple-choice examinations. More and more, techniques that center on review of examinee work have been employed, often resulting in the establishment of defensible, reproducible standards. The purpose of this article is to describe and evaluate a work-centered approach for determining the passing score for a performance-based assessment of clinical skills. A description of an approach to set passing scores that involves expert review of examinee work is presented. Application and evaluation of the method are illustrated using examination materials obtained from a high-stakes certification assessment.
Growth and silicon doping of AlxGa1−xP on GaP by gas source molecular beam epitaxy

Abstract Using PH 3 as the gas source and elemental Al and Ga, Al x Ga 1 − x P on (100) orientation GaP has been grown by gas source molecular beam epitaxy (GSMBE). In situ RHEED analysis indicates the growth of good quality single crystal epitaxial Al x Ga 1 − x P can be achieved for all Al mole fractions ranging between 0 and 1. Using elemental silicon as the dopant source, free electron carrier concentrations as high as 8×10 18 cm -3 for GaP and 6×10 18 cm -3 for Al 0.35 Ga 0.65 P have also been achieved with no observable saturation effects, which indicates higher carrier concentrations are obtainable.
Territorial exclusion and reproductive isolation

Three experiments demonstrate that Mongolian gerbils exclude intruders from home territories and force them to migrate across a water barrier. Of those animals that did migrate in the third experiment, the majority avoided olfactory cues from the territory from which they were excluded.
Access to Psycho-social Services Among Pregnant and Parenting Teens: Generating Questions Using Youth Reports and GIS Mapping Techniques

This is an exploratory study of receipt of psycho-social services within the health and mental health sectors among a small sample (n = 56) of pregnant and parenting teens. Utilizing conceptual frameworks of barriers to service and potential spatial accessibility, this study sought to demonstrate how mapping could contribute to analyzing issues such as access to care. Youth-reported negative neighborhood quality weakly predicted decreased likelihood of psycho-social service receipt, controlling for youth background, well-being and indicators of service accessibility. Geographic Information System (GIS) maps depicted variation in census tract proximity to services, with youth highest in need residing in tracts isolated from service providers.
Visualizing Alpha Helices in the Transmembrane Region of IP3R1 Calcium Release Channel by Single Particle Electron Cryomicroscopy

Type 1 inositol 1,4,5-trisphosphate receptor (IP3R1), a 1.3 MDa tetrameric membrane protein regulates the release of Ca2+ from endoplasmic reticulum stores into the cytoplasm and plays an essential role in a wide variety of cellular processes. We determined the structure of IP3R1 in the closed conformation at ∼9-A resolution by using single particle electron cryomicroscopy. The channel protein was solubilized with detergent from rat cerebellar microsomes and purified by immunoaffinity chromatography. The purified channels were reconstituted into Ca2+-loaded lipid vesicles and released Ca2+ in response to nanomolar concentrations of IP3, indicating their functionality. Isolated IP3R1 particles were embedded in vitreous ice for cryo-EM in the presence of 1 mM EGTA to drive the channel protein into its closed conformation. The 3D density map of IP3R1 was generated with 37,231 particles extracted from 929 CCD frames collected on a JEOL2010F electron cryomicroscope. The reconstruction was performed using EMAN software. This structure allows visualizing a number of alpha-helices in the membrane-spanning region of the IP3R1 channel, including the inner alpha-helices lining the tapering ion conduction pathway. The molecular architecture of the closed pore is established based on the 9-A cryo-EM density map of IP3R1 and via computational and bioinformatics approaches.This research is supported by grants from NIH (R01GM072804, P41RR02250) and MDA Research Grant 88677.
The effect of chirality on serotonin receptor affinity.

Abstract α-Methylation of phenethylamines or tryptamine appears to have very little effect on serotonin (5-HT) receptor affinity when racemates are examined. Examination of resolved materials, using an isolated rat stomach fundus preparation, reveals that the R-isomers of DOM and MDA and the S-isomer of α-methlytryptamine possess a higher 5-HT receptor affinity than do their enantiomers. While S(+)-DOB possesses a lower affinity than its racemate, R(-)-DOB produces an appreciable agonistic response which interferes with the measurement of p A2 values.