cssi/SciSciGPT-SciSciNet huggingface dataset:
Two Experiments Divided by 33 Years of Booming Semiconductor Physics (

Two experiments are described, both of them virtually unpublished. One dates back to 1959, when Fumi was my teacher in Pavia, and concerns surface carrier mobility in crystalline germanium. It may have some historical interest, mostly in connection with the wide gap that existed, in those years, between experimental solid-state research in Italy and, say, in the United States. The other one is a study, now in progress at the Physics Department of the University of Rome «La Sapienza» in collaboration with Mario Capizzi, of the electronic-level structure of gallium vacancies in high-purity GaAs, produced by molecular beam epitaxy. Key to this experiment is post-growth hydrogenation of the material by a controlled ion-beam irradiation method developed by our group. The two experiments are meant to give some feeling of the huge evolution that has characterized semiconductor research during the last three decades.
Chemokines, macrophage inflammatory protein-2 and stromal cell-derived factor-1α, suppress amyloid β-induced neurotoxicity

Abstract Alzheimer's disease (AD) is characterized by a progressive cognitive decline and accumulation of neurotoxic oligomeric peptides amyloid-β (Aβ). Although the molecular events are not entirely known, it has become evident that inflammation, environmental and other risk factors may play a causal, disruptive and/or protective role in the development of AD. The present study investigated the ability of the chemokines, macrophage inflammatory protein-2 (MIP-2) and stromal cell-derived factor-1α (SDF-1α), the respective ligands for chemokine receptors CXCR2 and CXCR4, to suppress Aβ-induced neurotoxicity in vitro and in vivo. Pretreatment with MIP-2 or SDF-1α significantly protected neurons from Aβ-induced dendritic regression and apoptosis in vitro through activation of Akt, ERK1/2 and maintenance of metalloproteinase ADAM17 especially with SDF-1α. Intra-cerebroventricular (ICV) injection of Aβ led to reduction in dendritic length and spine density of pyramidal neurons in the CA1 area of the hippocampus and increased oxidative damage 24 h following the exposure. The Aβ-induced morphometric changes of neurons and increase in biomarkers of oxidative damage, F2-isoprostanes, were significantly inhibited by pretreatment with the chemokines MIP-2 or SDF-1α. Additionally, MIP-2 or SDF-1α was able to suppress the aberrant mislocalization of p21-activated kinase (PAK), one of the proteins involved in the maintenance of dendritic spines. Furthermore, MIP-2 also protected neurons against Aβ neurotoxicity in CXCR2−/− mice, potentially through observed up regulation of CXCR1 mRNA. Understanding the neuroprotective potential of chemokines is crucial in defining the role for their employment during the early stages of neurodegeneration.
Limits to list decodability of linear codes

We consider the problem of the best possible relation between the list decodability of a binary linear code and its minimum distance. We prove, under a widely-believed number-theoretic conjecture, that the classical "Johnson bound" gives, in general, the best possible relation between the list decoding radius of a code and its minimum distance. The analogous result is known to hold by a folklore random coding argument for the case of non-linear codes, but the linear case is more subtle and has remained open.We prove our result by exhibiting an infinite family of binary linear codes of "large" minimum distance with a super-polynomial number (in blocklength) of codewords all within a Hamming ball of radius close to the Johnson bound. Even the existence of codes with a super-polynomial number of codewords in a ball of radius bounded away from the minimum distance (let alone radius close to the Johnson bound) was open prior to our work. We also unconditionally prove the "tightness" of the Johnson bound for decoding with list size that is an arbitrarily large constant.
Assessment of the Frequency of Allelic Imbalance in Human Tissue Using a Multiplex Polymerase Chain Reaction System

Genomic instability can generate chromosome breakage and fusion randomly throughout the genome, frequently resulting in allelic imbalance, a deviation from the normal 1:1 ratio of maternal and paternal alleles. Allelic imbalance reflects the karyotypic complexity of the cancer genome. Therefore, it is reasonable to speculate that tissues with more sites of allelic imbalance have a greater likelihood of having disruption of any of the numerous critical genes that cause a cancerous phenotype and thus may have diagnostic or prognostic significance. For this reason, it is desirable to develop a robust method to assess the frequency of allelic imbalance in any tissue. To address this need, we designed an economical and high-throughput method, based on the Applied Biosystems AmpFlSTR Identifiler multiplex polymerase chain reaction system, to evaluate allelic imbalance at 16 unlinked, microsatellite loci located throughout the genome. This method provides a quantitative comparison of the extent of allelic imbalance between samples that can be applied to a variety of frozen and archival tissues. The method does not require matched normal tissue, requires little DNA (the equivalent of ∼150 cells) and uses commercially available reagents, instrumentation, and analysis software. Greater than 99% of tissue specimens with ≥2 unbalanced loci were cancerous.
Thiophosphorylated RCM-Lysozyme, an Active Site-Directed Protein Tyrosine Phosphatase Inhibitor, Inhibits G2/M Transition during Mitotic Cell Cycle and Uncouples MPF Activation from G2/M Transition

Microinjection of thiophosphotyrosylated RCM-lysozyme (TRCML), a potent and specific inhibitor of protein tyrosine phosphatases (PTPs) into sea urchin (Lytechinus pictus) eggs prior to fertilization inhibited the first zygotic cell division in a concentration-dependent fashion. Microinjection of TRCML at varying times after fertilization indicated that at least one site of action is late in the first cell cycle near the G2/M boundary. In order to further study the mechanism for the TRCML effect, a cell-free cell cycling system prepared from electrically activated Xenopus eggs was used. The addition of TRCML to cycling extracts delayed the entrance and progression of extracts through mitosis, as indicated by the inhibition of chromatin condensation, nuclear envelope breakdown, M-phase-promoting factor (MPF) inactivation, and cyclin degradation. Surprisingly, TRCML did not inhibit MPF activation. These results suggest that (1) the target(s) of TRCML lies in late G2- or early M-phase before the onset of metaphase, (2) TRCML uncouples MPF activation from progression through M-phase, and (3) there is a potential involvement of a novel PTP(s) in the control of the cell cycle which may act either downstream of the MPF activation or alternatively in an additional but essential mitotic pathway that is parallel to the MPF activation pathway.
Electrical alternans and cardiac electrical instability.

We investigated the relationship between electrical alternans and cardiac electrical stability in a series of 20 dog experiments and in a pilot clinical study. Electrical alternans was detected in both the QRS complex and the ST-T wave by use of a novel multidimensional spectral technique. The magnitude of the alteration was expressed as the alternating electrocardiographic morphology index (AEMI), expressed as parts per million of waveform energy. Electrical stability in the dog preparations was assessed via the ventricular fibrillation threshold measurement, and in the clinical studies via programmed stimulation. In 10 dog experiments, systemic hypothermia resulted in a 60% decrease in ventricular fibrillation threshold (VFT) (p less than .0001) and a significant increase in both AEMI(QRS) form 3.7 +/- 3.0 to 1448 +/- 548 (p less than .0001) and AEMI(ST-T) from 43.9 +/- 18.4 to 19,178 +/- 5579 (p less than .0001). In 10 dog experiments, transient coronary artery ligation also resulted in a 60% decrease in VFT (p less than .0001), an increase from 76.3 +/- 46.5 to 245 +/- 11 in AEMI(QRS) (p less than .05), and an increase from 842 +/- 505 to 1365 +/- 392 in AEMI(ST-T) (p less than .002). In 119 observations in 20 animal experiments, the rank correlation between VFT and AEMI(QRS) was -.30 (p less than .001), with that between VFT and AEMI(ST-T) being -.55 (p less than .0001). In a double-blind pilot clinical trial consisting of 23 studies in 19 patients, the result of electrophysiologic testing was used as an independent measure of cardiac electrical stability. Alternation in waveform morphology identified the inducible patient population with a sensitivity of 92%, a positive predictivity of 70%, and a specificity of 50% (p less than .05). We conclude that analysis of subtle beat-to-beat variability in electrocardiographic morphology may provide a noninvasive measure of cardiac electrical stability.
Solid-source boron doping of float-zoned silicon

Abstract We report on a solid-source B doping method for float-zone growth that uses nontoxic pyrolytic boron nitride as the source material and has the flexibility to allow step changes in doping concentration during the growth process. Doping concentrations of 6×10 16 cm −3 or less (⩾0.3 Ω-cm resistivity) can be achieved in meter-long crystals without exceeding the solubility limit for N. Shorter crystals can be doped more heavily. The time required to transition from undoped (5000 Ω-cm) growth to a 0.2 Ω-cm uniform doping level is about 3 min. This corresponds to less than 1 cm of growth at 0.3 cm min −1 . Doping uniformity is within 9% or better axially and 2% radially. We present and experimentally substantiate model equations for dopant incorporation from a pyrolytic BN solid-source, for B dopant dissipation when the source is removed, and for nitrogen co-dopant incorporation.
A Comparison of Three Algorithms for Orion Drogue Parachute Release

The Orion Multi-Purpose Crew Vehicle is susceptible to ipping apex forward between drogue parachute release and main parachute in ation. A smart drogue release algorithm is required to select a drogue release condition that will not result in an apex forward main parachute deployment. The baseline algorithm is simple and elegant, but does not perform as well as desired in drogue failure cases. A simple modi cation to the baseline algorithm can improve performance, but can also sometimes fail to identify a good release condition. A new algorithm employing simpli ed rotational dynamics and a numeric predictor to minimize a rotational energy metric is proposed. A Monte Carlo analysis of a drogue failure scenario is used to compare the performance of the algorithms. The numeric predictor prevents more of the cases from ipping apex forward, and also results in an improvement in the capsule attitude at main bag extraction. The sensitivity of the numeric predictor to aerodynamic dispersions, errors in the navigated state, and execution rate is investigated, showing little degradation in performance.
Is halogen bonding the basis for iodothyronine deiodinase activity

Density functional theory studies of S···X and Se···X (X = Br, I) halogen-bonding interactions are used to interpret the selection of selenium and iodine for thyroid hormone signaling. A new mechanism for dehalogenation in terms of halogen bonding is proposed. The activation barriers for deiodination of an aromatic iodide by MeSeH and MeSH (17.6 and 19.8 kcal/mol) are consistent with the relative rates of deiodination by iodothyronine deiodinase and its cysteine mutant.
Simulation levels of detail for plant motion

In this paper we describe a method for simulating motion of realistically complex plants interactively. We use a precomputation stage to generate the plant structure, along with a set of simulation levels of detail. The levels of detail are made by continuously grouping branches starting from the tips of the branches and working toward the trunk. Grouped branches are simulated as single branches that have similar simulation characteristics to the original branches. During run-time, we traverse the plant and determine the allowable error in the simulation of branch motion. This allows us to choose the appropriate simulation level of detail and we provide smooth transitions from level to level. Our level of detail approach affects only the simulation parameters, allowing geometry to be handled independently. Using this method we can significantly improve simulation times for complex trees.
Hospital Tuberculosis: Beyond the Inner City

Tuberculosis (TB) today is not an equal opportunity infection. Occurrence of the disease has focused on the inner city, where dramatic increases of TB disease in the poor, the homeless, the victim of acquired immunodeficiency syndrome (AIDS), and the immigrant are most prominent. The focus is clear. For example, incidence of TB is 10 to 20 times greater in the South Bronx, Brooklyn, and Harlem in New York City than in the United States as a whole.1 In these large urban areas, population lifestyle as well as the disease make case detection difficult. In addition, many of the inner-city groups in which TB occurs today also are less likely to comply with antituberculous therapy. Such lack of follow-up greatly enhances the likelihood that drug resistance may emerge and increases the potential for transmission in this setting. Directly observed therapy (DOT) is a proven mechanism to deal with these problems.2 However, accomplishing DOT in these areas demands new cadres of case workers to implement programs. The inner city also is the most likely site for nosocomial TB. Some hospitals in these areas can account for sizable proportions of an area's cases. For example, at Grady Memorial Hospital in Atlanta, more than 250 new TB cases were diagnosed in 1992; if this metropolitan public hospital were its own state, it would have ranked about 26th in case total for the entire country.3 Because rates of TB are high in the patient population of large urban hospitals, and because these clients also are more likely to have AIDS or other associated diseases that make TB detection difficult, this setting is where risk of transmission to healthcare workers and other patients rises. In such an environment, it is logical and important to implement procedures for prevention of nosocomial transmission. Guidelines to accomplish this have emerged from investigations of several nosocomial outbreaks in urban hospitals in the past few years.4 Implementation of these procedures has proven effective in several urban hospitals.3,5 However, such guidelines have been extraordinarily cost y to implement.6 When one leaves the inner city, the best tactics to deal with TB are less certain. In the 1980s and earlier, the national plan for eradication of TB was aimed primarily at treating elderly individuals, who developed disease due to reactivation of long-ago infection. These cases could arise as easily in the suburbs or rural areas as i the city center. By contrast, recent national plans and guidelines to deal with multidrug-resistant TB (MDR-TB) dwell heavily (almost exclusively) on the inner-city constituency and on primary and directly transmitted infection.7 What to do with the cases outside these main centers of the battle against TB and MDR-TB is n t delineated clearly. Yet, national plans seem to assum that what is needed in the inner city should be implemented as well in suburban or rural se tings. This is not necessarily so. What makes medical and economic sense in the metropolitan area may not be either efficient or effective when the setting shifts and the target population changes.8
Etanercept (Enbrel) Administration for Idiopathic Pneumonia Syndrome after Allogeneic Hematopoietic Stem Cell Transplantation

Abstract Acute pulmonary dysfunction remains a frequent and severe complication of hematopoietic stem cell transplantation (SCT). Almost half of the pulmonary insults that occur in this seating are noninfectious in origin and are referred to as idiopathic pneumonia syndrome (IPS). In this series of 3 patients, etanercept (Enbrel; Immunex, Seattle, WA), a soluble, dimeric tumor necrosis factor alpha-binding protein, was administered to 3 consecutive pediatric allogeneic BMT recipients with IPS. The administration of etanercept, in combination with standard immunosuppressive therapy, was well tolerated and associated with significant improvements in pulmonary dysfunction within the first week of therapy. These data suggest that etanercept may represent a safe, non-cross-reactive, therapeutic option for patients with IPS and that clinical trials studying etanercept for this indication are warranted. Biol Blood Marrow Transplant 2002;8(7):395-400.
SECONDARY REINFORCEMENT AND RATE OF PRIMARY REINFORCEMENT1

Four pigeons were trained to peck at either of two response-keys. Pecking at either key occasionally produced a secondary reinforcer. Then, in the presence of the secondary reinforcer, further pecking occasionally produced the primary reinforcer, food. The relative rate at which each pigeon pecked to obtain a secondary reinforcer equalled the relative rate of primary reinforcement in its presence.
Guizot's elitist theory of representative government

Abstract In nineteenth‐century Europe, democracy was not embraced with the same enthusiasm it now enjoys. Conservative critics questioned central democratic normative principles, while liberals tried to correct the limitations of actual democratic practice. While accepting the inevitability of democracy, nineteenth‐century liberals often resisted the idea that universal suffrage guaranteed the wisdom of the people's choices. Nothing better illustrates this difficult apprenticeship of democracy than the writings of Francois Guizot, whose political thought focuses on the relationship between liberalism and democracy.
Anatomic indicators (histologic and cytologic) of increased breast cancer risk

Anatomic indicators of increased breast cancer risk have regularly been identified as hyperplastic lesions, analogous to other body sites. Most of these have been shown to indicate a later increased risk anywhere in either breast and should thus be regarded as indicators or markers of increased risk. Unfortunately, these are largely identified incidentally to current methods of detection. Specific combined histologic and cytologic criteria for the definition of these lesions have been evaluated for both their reproducibility of diagnosis and outcome variables. Several studies agree that usual patterns of hyperplasia of at least moderate degree indicate an increased risk of later breast carcinoma between 1.5 and 2 times that of the general population. The specifically defined examples of atypical hyperplasia, lesions of relative rarity, are found in 4–5% of biopsies (depending upon method of detection) and recognize a risk in the range of 4–5 times that of the general population controlled for age and duration of follow-up. Thus, several cohort studies using comparable criteria for definition of the anatomic lesions have found similar clinical outcomes. Other approaches to histologic definition have produced a lesser degree of separation between the non “atypical” and other forms of hyperplasia. Although it is not clear whether we are dealing with continuous variables or discrete histologic/cytologic variables, it is clear that when combined criteria are used, a greater degree of predictability is obtained. Other related risk features include most predominantly family history, which when present with atypical hyperplasia indicates an increased risk beyond that of either alone. Other means of detection of these various lesions, such as fine needle aspiration cytology, have not been verified. True non-obligate precursors of breast cancer are probably confined to low grade and non-comedo ductal carcinomas of the breast.
Analysis of sample-path optimization

Sample-path optimization is a method for optimizing limit functions occurring in stochastic modeling problems, such as steady-state functions in discrete-event dynamic systems. It is closely related to retrospective optimization techniques and to M-estimation. The method has been computationally tested elsewhere on problems arising in production and in project planning, with apparent success. In this paper we provide a mathematical justification for sample-path optimization by showing that under certain assumptions---which hold for the problems just mentioned---the method will almost surely find a point that is, in a specified sense, sufficiently close to the set of optimizers of the limit function.
Genetics of Lipid Traits and Relationship to Coronary Artery Disease

Despite the critical importance of plasma lipoproteins in the development of atherosclerosis, varying degrees of evidence surround the causal associations of lipoproteins with coronary artery disease (CAD). These causal contributions can be assessed by employing genetic variants as unbiased proxies for lipid levels. A relatively large number of low-density lipoprotein cholesterol (LDL-C) variants strongly associate with CAD, confirming the causal impact of this lipoprotein on atherosclerosis. Although not as firmly established, genetic evidence supporting a causal role of triglycerides (TG) in CAD is growing. Conversely, high-density lipoprotein cholesterol (HDL-C) variants not associated with LDL-C or TG have not yet been shown to be convincingly associated with CAD, raising questions about the causality of HDL-C in atherosclerosis. Finally, genetic variants at the LPA locus associated with lipoprotein(a) [Lp(a)] are decisively linked to CAD, indicating a causal role for Lp(a). Translational investigation of CAD-associated lipid variants may identify novel regulatory pathways with therapeutic potential to alter CAD risk.
Minority group status and treatment retention

Study was made of the extent to which majority/minority status within program was associated with treatment outcome. Examining situations in which Blacks, Mexican-Americans, and Whites constituted significant majorities or minorities within each of three treatment modalities, it was found that minority status had particular relevance for treatment retention and for type of discharge in drug-free outpatient programs. Minority status was less significant to treatment outcome in methadone maintenance and residential programming. Several hypotheses are offered to explain the greater significance of race/ethnic issues for outpatient drug-free programming.
Irrigation management alternatives: Themes from indigenous irrigation systems☆

Abstract Those responsible for irrigation development are perplexed regarding the organisation and management of these systems. This paper discusses irrigation management alternatives based on cases of indigenous irrigation systems that exist around the world. Many of these indigenous systems illustrate locally derived solutions to recurring problems in modern systems. This paper discusses three organisational themes that derive from analysis of local systems: accountable leadership; mini-unit organisation and canal-based organisational units. Finally, the discussion suggests three situations in which themes from indigenous systems may be especially relevant; first, when irrigation development policy includes the improvement of existing traditional systems; second, when a nation is investing in the development of new small-scale systems and, third, where large-scale systems are being designed so as to create smaller sub-units relatively independent of the total system.
Nature, nurture, or that fast food hamburger: media framing of diabetes in the New York Times from 2000 to 2010.

Diabetes is a growing yet misunderstood health concern in the United States. This study examined the ways in which diabetes has been framed by the New York Times over the past decade. The public's ...
A heuristic for optimizing the multiplication of matrix chains

A consequence of the associative property of matrix multiplication is that the product of n matrices can be calculated in (n-1)! ways. Different choices for the multiplication sequence can cause the numbers of scalar multiplications required to vary by several orders of magnitude. The optimal ordering with respect to number of scalar multiplications can be found in O(n3) time using dynamic programming. A heuristic is presented which finds an optimal or nearly optimal strategy in O(n2) time in its most straightforward implementation. The problem is important in interpretation or code generation for languages which allow high-level manipulation of matrices.
THE MEANING OF LIFE AND OLDER LEARNERS: ADDRESSING THE FUNDAMENTAL ISSUE THROUGH CRITICAL THINKING AND TEACHING

Although the importance of meaning in life has been recognized in the educational gerontology literature, scholars have given little in the way of an analysis of the concept and even less information about effective ways to plan and conduct educational programs for older learners who are interested in the meaning of life. This article examines the definition of the meaning of life and suggests that the concept is best understood when viewed as “meaning making,” that is, as an individual activity that occurs when persons are faced with an experience that challenges their basic assumptions about the world and that requires them to make meaning of the experience by filtering it through their basic assumptions. Experiences that confront the basic assumptions of older learners are used as illustrations to explain meaning making by older adults. Meaning making is favorably compared with perspective transformation, which establishes a theoretical framework for discussing ways to address the meaning of life in ed...
The Refinement of Empathy

This article traces refinements in empathic knowing, highlighting the phenomenon of deep empathy. Nine different levels or facets of the activity of empathic knowing are described. Included is discussion of therapeutic resonance, deep reactivity, and alterations in self-other boundaries. In recognizing his or her own underlying epistemic process, the therapist may be better able to appreciate, cultivate and deepen his or her own unique ways of meeting and understanding the client.
The Distribution of Criminal Offenses in an Urban Environment: A Spatial Analysis of Criminal Spillovers and of Juvenile Offenders

Abstract. In order to derive a basis for an optimal allocation of police manpower among contiguous communities criminal spillovers among these communities must be explicitly taken into account. Under the assumptions established in the economic theory of choice a criminal spillovers model is derived. The hypothesized variables within this model which serve as motivating factors for criminal spillovers are economic gain and competitive criminal pressures. Those factors which deter criminal spillovers are costs of committing offenses and the relative risks in committing crimes in distant communities. The model is then tested using data on juvenile offenders supplied by the City of Los Angeles, for the crimes of robbery, burglary and larceny. The results suggest that on an aggregate basis juvenile criminal behavior is not purely opportunistic and that certain control and motivating factors are significant in the juvenile's judgments for the spatial selection of offense targets.
The Influence of Drainage From the Las Vegas Valley on the Limnology of Boulder Basin, Lake Mead, Arizona-Nevada

ABSTRACT Lake Mead, Colorado River, Arizona-Nevada, is one of the most heavily used reservoirs in the Western United States, providing abundant recreational opportunities as well as downstream domestic and agricultural water for over 22 million users. Based on average nutrient levels and productivity, Lake Mead is classified as mildly mesotrophic. The insertion into the water column of the Colorado River dominates the limnology of much of the 106 km-long reservoir, and may still be identified at Hoover Dam under certain conditions. The lower basin of Lake Mead ending at Hoover Dam is known as Boulder Basin and is near the Las Vegas metropolitan area. Las Vegas Bay, which comprises the northwestern portion of Boulder Basin, receives all runoff from the Las Vegas Valley via Las Vegas Wash. Inflow includes urban storm flows, secondary and tertiary treated municipal sewage effluent and groundwater seepage. The rapid increase in population of Las Vegas Valley and subsequent increased volume of point and non-po...
Crustacean Neurosecretory Hormones and Physiological Specificity

Physiological effects of neurosecretory factors from crustaceans are examined for their hormonal specificity. Hyperglycemic hormone (HGH) from the eyestalk is a polypeptide, molecular weight about 7,000; it may activate phosphorylase and inhibit glycogen synthetase. Four pigmentary effectors (distal retinal pigment, melanophores, erythrophores and leucophores) respond to a peptide hormone (DRPH) having a molecular weight of 2,000. An earlier suggestion (Kleinholz, 1970) that light-adaptation of the distal retinal pigment and dispersion of pigment granules in chromatophores may be regulated by the same hormonal molecule is confirmed by test with synthetic hormone. Concentrators oferythrophore (ECH) and leucophore (LCH) pigments are peptides with respective molecular weights of 1,000 and about 1,500 daltons. Three factors which affect succinate oxidation by mitochondria appear in the three chromatographic zones eluted from G-25 Sephadex which contain DRPH, LCH and ECH, and therefore presumably are of about the same molecular size as the pigment hormones. The second and third of these factors have been shown to be distinctly different from the hormones with which they are initially eluted. Factors influencing hydromineral regulation, molt- and gonad-inhibition, cardiac activity, respiratory rates and lipid metabolism are reviewed.
Intentions to receive individual results from whole-genome sequencing among participants in the ClinSeq study

Intentions to receive individual results from whole-genome sequencing among participants in the ClinSeq study
Mineral element concentrations of sorghum genotypes grown on tropical acid soil

Abstract Sorghum [Sorghum bicoior (L.) Moench] genotypes show large differences in dry matter and yield when grown on many tropical acid soils. The objective of this study was to determine differences in mineral element concentrations in sorghum genotypes grown on an acid oxisol limed with 2 and 6 Mg dolomitic limestone ha‐1 in Colombia, South America. Fifty genotypes showed differences in dry matter yield and concentrations of P, K, Ca, Mg, S, Si, Al, Mn, Cu, and Zn. Liming did not change low, high, and mean leaf concentrations of P, K, Mg, S, and Cu for the genotypes. Concentrations of Al, Mn, and Fe in the genotypes were higher in leaves of plants grown at 2 (pH 4.5 and 62% AT saturation) than at 6 Mg lime ha‐1 (pH 4.8 and 34% Al saturation). At the 6 Mg ha‐1 lime rate, leaf concentrations of Ca and Si increased. Silicon may have reduced the effects of toxic Al, and possibly toxic Fe. Genotypes showed sufficient variability in mineral element concentrations that selection for improved values of these t...
Cerebral blood flow during spike-wave discharges.

Summary We used the 133xenon method to assess cerebral blood flow (CBF) during generalized spike-wave discharges in a patient with an uncommon form of generalized epilepsy with persistent spike-wave discharges. CBF measurements were made under four conditions with repeated measures: normal EEG, continuous theta state, continuous spike-wave state at rest, and continuous spike-wave discharges during performance of a cognitive activation task. CBF was mildly reduced (5.7%) during the theta state and decreased further (12%) in the spikewave state. Although globally diminished, CBF was less decreased in the frontal lobes and more decreased in the parietal lobes during spike-wave discharges. CBF increased to baseline levels during the cognitive activation task. The decrease in CBF suggested that the generalized spike-wave discharges caused a net decrease in cortical metabolic demand and neuronal activity. The differences in lobar CBF during spike-wave discharges may reflect lobar disparities in neuronal firing patterns. The theta state noted is novel and intermediate between normal and spike-wave.
Aspects of supersymmetric models with a radiatively driven inverted mass hierarchy

A promising way to reconcile naturalness with a decoupling solution to the SUSY flavor and CP problems is suggested by models with a radiatively driven inverted mass hierarchy (RIMH). The RIMH models arise naturally within the context of SUSY SO(10) grand unified theories. In their original form, RIMH models suffer from two problems: (1) obtaining the radiative breakdown of electroweak symmetry; and (2) generating the correct masses for third generation fermions. The first problem can be solved by the introduction of SO(10)D-term contributions to scalar masses. We show that correct fermion masses can indeed be obtained, but at the cost of limiting the magnitude of the hierarchy that can be generated. We go on to compute predictions for the neutralino relic density as well as for the rate for the decay b{r_arrow}s{gamma}, and show that these yield significant constraints on model parameter space. We show that only a tiny corner of model parameter space is accessible to Fermilab Tevatron searches, assuming an integrated luminosity of 25 fb{sup {minus}1}. We also quantify the reach of the CERN LHC collider for this class of models, and find values of m{sub {tilde g}}{similar_to}1600 GeV to be accessible assuming just 10 fb{sup {minus}1} ofmore » integrated luminosity. In an appendix, we list the two loop renormalization group equations for the MSSM plus right handed neutrino model that we have used in our analysis.« less
Directing the outcome of deoxyribozyme selections to favor native 3'-5' RNA ligation.

Previous experiments have identified numerous RNA ligase deoxyribozymes, each of which can synthesize either 2‘,5‘-branched RNA, linear 2‘−5‘-linked RNA, or linear 3‘−5‘-linked RNA. These products may be formed by reaction of a 2‘-hydroxyl or 3‘-hydroxyl of one RNA substrate with the 5‘-triphosphate of a second RNA substrate. Here the inherent propensities for nucleophilic reactivity of specific hydroxyl groups were assessed using RNA substrates related to the natural sequences of spliceosome substrates and group II introns. With the spliceosome substrates, nearly half of the selected deoxyribozymes mediate a ligation reaction involving the natural branch-point adenosine as the nucleophile. In contrast, mostly linear RNA is obtained with the group II intron substrates. Because the two sets of substrates differ at only three nucleotides, we conclude that the location of the newly created ligation junction in DNA-catalyzed branch formation depends sensitively on the RNA substrate sequences. During the exper...
Work behavior correlates of interviewer job compatibility

Forced-choice scales were developed to measure the compatibility between worker preferences for job characteristics and actual characteristics of the job for purposes of predicting turnover and performance. The data confirmed the construct and criterion-related validity of the compatibility scores, but also indicated that the relationship between compatibility and voluntary termination was moderated by employee characteristics. Discussion centers on the implications of these findings for future job compatibility scale development and the application of this methodology to work settings where relatively homogeneous subgroups of employees differ with respect to personal and work circumstances.
Two promoters control the transcription of the human α2(VI) collagen gene

Our previous studies have demonstrated that the human α2(VI) collagen gene produces four mRNA species with different 5′-untranslated regions [Saitta, B., Timpl, R. & Chu, M.-L. (1992) J. Biol. Chem. 267, 6188–6196]. The major mRNA species initiates from exon 1, located at the most 5′ end, whereas three minor mRNAs start from an alternative exon, 1A, located 657 bp downstream of exon 1. In this study, we have investigated whether or not these different mRNAs are transcribed from two separate promoters. DNA fragments preceding exons 1 and 1A were fused with a reporter gene for chloramphenicol acetyl transferase (CAT) and transfected into human dermal fibroblasts and fibrosarcoma HT1080 cells. Strong CAT activity in both cell types was observed using a construct containing DNA from nucleotide −502 to +115 preceding exon 1. The CAT activity of a construct containing nucleotide +514 to +894 preceding exon 1A was almost as high as that of the former construct, indicating the presence of two promoters, P1 and P2, preceding exons 1 and 1A, respectively. Transient transfection assays also identified positive and negative regulatory regions for the P1 promoter, located from nucleotide −2152 to −1384 and from nucleotide −1383 to −503, respectively. A negative regulatory region located at nucleotide +116 to +513 was found for the P2 promoter. This region strongly inhibits the P2 promoter in dermal fibroblasts, and thus may be responsible for the low expression of the endogenous exon-1A-containing mRNAs in these cells. Footprinting analysis of the two promoters with purified Sp1 protein and AP2 protein extract showed several sites of DNA-protein interaction. The specificity of these sites was confirmed by competition experiments using consensus Sp1 and AP2 oligonucleotides. The results thus demonstrate that the human α2(VI) collagen gene contains two promoters, which are regulated by positive and negative cis-acting DNA elements and trans-acting factors.
Esterase and malate dehydrogenase isozyme polymorphisms in 15 Artemia populations

Abstract 1. 1. Starch gel electrophoresis of adult brine shrimps from 15 populations revealed little intrapopulation polymorphism in NAD-dependent malate dehydrogenase (MDH) isozymes or in the two fastest esterases (demonstrated with alpha-naphthyl propionate as substrate). 2. 2. Interpopulation differences could be summarized as three different electrophoresis band patterns for the five- to seven-banded MDH isozymes and another three patterns for the two fastest esterases. 3. 3. These differences in electrophoresis patterns divide the 15 Artemia populations into four categories (each containing one to seven populations) which may be distinguished by isozyme content and which are congruent with categories established by the criterion of reproductive isolation in an earlier study.
The State and the Pursuit of the National Economic Interest

ABSTRACT A developmental state is autonomous and pursues the national economic interest. The extent of a state's autonomy is related to the characteristics of its predominant economic sector. The degree to which a state pursues the national interest is related to its vulnerability. Both autonomy and vulnerability can be influenced via policy. The creation of an integrated market system based upon broad based agricultural development creates an environment in which autonomy can be increased and the national economic interest can be formulated and pursued. Alternatively, the creation of large, highly diversified business groups can also serve as a basis for autonomous policy making in the national economic interest. These ideas are illustrated with the experiences of South Korea and Taiwan.
Ethanol inhibits the sensory responses of cerebellar granule cells in anesthetized cats.

Background: Granule cells occupy a strategic position in the transmission of afferent information to the cerebellar cortex. They are also the most abundant type of neurons in the cerebellum. The functions of the cerebellum are thought to be sensitive to acute alcohol intoxication. The effects of acute alcohol intoxication on the in vivo physiology of cerebellar granule cells are, however, not completely known. Methods: We studied chloralose-anesthetized cats at ethanol doses relevant to human drinking (0.3–1.2 g/kg). We recorded the electrophysiological responses of granule cell clusters to auditory and visual stimulation, and simultaneously monitored the concentration of ethanol in the cerebrospinal fluid (CSF). Results: At an intravenous ethanol dose of 0.3 g/kg, CSF ethanol concentration peaked in 10 minutes at 17 mM, equivalent to a blood alcohol concentration (BAC) of about 0.08 g/dL. Ethanol quickly and almost completely abolished both auditory and visual responses from granule cells. Complete or near-complete inhibition lasted 15 to 20 minutes; ∼50% recovery required an additional 15 minutes, and a full recovery yet another 15 minutes. A higher ethanol dose at 1.2 g/kg resulted in a more severe inhibition and required longer time for recovery. The relationship between ethanol dose, CSF ethanol concentration, and granule cell responses was dynamic and nonlinear, critically depending upon the elapsed time. Conclusions: Cerebellar granule cell sensory responses are highly sensitive to ethanol inhibition. A rapid development of acute tolerance appears to be a major factor contributing to the dynamic and nonlinear relationship among ethanol dosage, CSF ethanol concentration, and granule cell responses. It is likely that a generalized de-afferentation of the cerebellum from its mossy fiber afferents, followed by the subsequent development of acute tolerance may play major roles by which alcohol intoxication affects cerebellar functions.
Target assignment for multi-fighters coordinated air combat based on VLSN

This paper presents the VLSN (very large scale neighborhood) search algorithm for weapon-target assignment problem in multi-fighters air combat. First, an intercept time method to evaluate the fighters' situation is brought up according to the character of “Beyond Visual Range Air Combat”. Second, the process of VLSN to search the best solution for target assignment is presented and meantime the parallel computation is introduced into the VLSN in order to minimize the searching time. Finally, numerical simulation results demonstrate that the VLSN is more efficient and costs less time compared with other algorithms.
Commentary: toward safe and high quality care through peer review in radiation oncology: need for more evidence.

The planning process involved prior to starting radiation treatment, which can often take up to 1 to 2 weeks, and the daily nature of treatment for multiple weeks, provide a unique opportunity for radiation oncologists to perform peer review of treatment plans. Indeed, routine peer review occurs in the majority of radiation oncology centers.1,2 In contrast to “morbidity and mortality” conferences, in which quality improvement and an infrastructure for learning is built around patient events that have already occurred, the goal of the peer review program in radiation oncology is to identify potential errors either before treatment starts or early enough during the treatment course to prevent harm to the patient. In the current era where there is an increasing emphasis on “quality” medical care and patient safety, radiation oncology leads by example with our longstanding culture for peer review and creation of treatment summaries, the latter concisely documenting treatment received and helping prevent future unintentional reirradiation. While peer review within each radiation oncology center is common, Ballo et al (in this issue of the journal) describe a novel program where an academic center
Design Considerations for the Electrical Distribution System of an American Retreating Longwall

Some of the electrical problems encountered with starting and operating an American retreating longwall are addressed. Some basic design considerations are pointed out that should be satisfied in choosing the electrical distribution system required for the longwall. Basic criteria for motor selection for the armored face conveyor are also discussed. Lastly, the economic considerations in choosing a distribution system are examined.
Rapid degradation of alkanethiol-based self-assembled monolayers on gold in ambient laboratory conditions

Abstract Self-assembled monolayers (SAMs) consisting of alkanethiols and similar sulfur-containing molecules on noble metal substrates are extensively used and explored for various chemical and biological surface-functionalization in the scientific community. SAMs consisting of thiol- or disulfide-containing molecules adsorbed on gold are commonly used due to their ease of preparation and stability. However, the gold–thiolate bond is easily and rapidly oxidized under ambient conditions, adversely affecting SAM quality and structure. Here, the oxidation of dodecanethiol on gold is explored for various 12-h exposures to ambient laboratory air and light. SAM samples are freshly prepared, air-exposed, and stored in small, capped vials. X-ray photoelectron spectroscopy (XPS) reveals nearly complete oxidation of the thiolate in air-exposed samples, and a decrease in carbon signal on the surface. Near-edge X-ray absorption fine structure spectroscopy (NEXAFS) at the carbon K-edge shows a loss of upright orientational order upon air exposure. Alternatively, the oxidation of the thiolate is minor when SAMs are stored in limited-air-containing small 15 ml vials. Thus, care must be taken to avoid SAM degradation by ensuring alkanethiolates on gold have sufficient durability for each intended environment and application.
Pigs on the Plains: Institutional Analysis of a Colorado Water Quality Initiative

Abstract We used the Legal-Institutional Analysis Model (LIAM) and Advocacy Coalition Framework (ACF) to analyze the campaign over passage of the Colorado Hogs Rule, an initiative passed by the voters in 1998 to require regulation of swine production facilities in Colorado. Used in tandem, LIAM and ACF provided an opportunity to develop a robust understanding of the obstacles and opportunities that face water quality managers in a state-centered multi-organizational decision process. We found that combining the LIAM with the ACF enhanced the understanding that could be achieved by using either model in isolation. The predictive capacity of the LIAM would have been reduced without information from the ACF, and the ACF by itself would have missed the importance of a single-case study.
Identifying decomposition products in extracts of cellular metabolites.

Most methods of analyzing intracellular metabolites require extraction of metabolites from the cells. A concern in these methods is underestimation of metabolite levels due to incomplete extraction. In comparing extraction methods, it would accordingly seem that the best method for extracting a particular metabolite is the one giving the largest yield. In extracting Escherichia coli with different methanol:water mixtures, we observed that ≥ 50% water gave increased yield of nucleosides and bases compared to ≤ 20% water, as determined by liquid chromatography-tandem mass spectrometry analysis of the resulting extracts. Spiking of the extracts with isotope-labeled nucleotides revealed, however, that the high yield of nucleosides and bases occurred due to decomposition of nucleotides in the water-rich condition, not good extraction. Spiking combined with isotope labeling provides a general approach to detecting decomposition products in extracts of cellular metabolites. For extraction of E. coli with methanol:water, cold temperature and a high methanol fraction minimizes artifacts due to metabolite decomposition.
A System for Culture of Endothelial Cells in 20–50-μm Branching Tubes

Objective: To construct an in vitro endothelial cell culture system which would mimic the geometry and hemodynamic conditions of the arteriolar microcirculation.Methods: Using a photolithography technique, semicircular channels (20–50 μm in diameter) were etched in mirror-image patterns on pairs of borosilicate microscope slide glass. One-half of each plate pair was predrilled with perfusion port holes at funnel-shaped fluid entrance regions. The perfusion system was constructed of micropipette glass and Teflonr` tubing, and imbedded in Sylgardr`. Two types of endothelial cells were grown to confluence within the half-channels: rabbit lung microvascular endothelial cells (a gift of Dr. M.E. Gerritsen, Miles Inc.) and human umbilical vein endothelial cells. After the cells were confluent, the two mirror images were aligned and clamped together to form a complete branching system of tubes lined with endothelial cells.Results: This cell culture system can be perfused at physiological flow rates corresponding...