cssi/SciSciGPT-SciSciNet huggingface dataset:
Peer Status and Aggression as Predictors of Dating Popularity in Adolescence

Research has identified links between dating and aversive behavior such as aggression and bullying in adolescence, highlighting the need for studies that further our understanding of romantic relationships and their dynamics during this period. This study tested the associations between dating popularity and overt and relational aggression, social preference, and peer popularity. Of particular interest were the moderating roles of social preference and peer popularity in the association of aggression with dating popularity. Further moderation by gender was also explored. Participants were 478 ninth-graders (48% girls) with peer nomination scores for peer status, aggression, and dating popularity. Dating popularity was positively correlated with popularity, social preference, and overt and relational aggression. Regression models indicated that popular, overtly aggressive girls were seen as desirable dating partners by their male peers. Relational aggression was associated with dating popularity for both boys and girls, especially for youths who were well-liked by peers. These findings are interpreted in light of developmental-contextual perspectives on adolescent romantic relationships and Resource Control Theory.
The hydrolysis of phosphorylcholine-containing metabolites in plant tissues : partial purification of a CDP-choline hydrolase from Solanum tuberosum

Abstract Five plant tissues were extracted and found to contain enzymes which could hydrolyze p- nitrophenylphorylcholine (PNP-PC), an artificial substrate which has been reported to be a convenient substrate for measuring the activity of phospholipase C. The leaves and tubers of Solanum tuberosum L. were then examined in more detail and found to contain enzymes which were capable of hydrolyzing several phosphorylcholine-containing metabolites. These metabolites included phosphatidylcholine (PC), glycerol phosphorylcholine, and cytodine diphosphocholine. The PNP-PC hydrolase from potato leaves was partially purified (a 229-fold increase in specific activity was achieved) and was found to have a molecular weight of about 28,000 and an isoelectric pH of approximately 6.8. When PNP-PC was used as a substrate, the enzyme was found to exhibit optimal activity at pH 6.0, was inhibited by Zn 2+ , and was found to have a K m of about 10 mM for PNP-PC. This hydrolytic enzyme activity was then tested for activity with naturally-occurring phosphorylcholine-containing metabolites and was found to hydrolyze CDP-choline but not PC or glycerol phosphorylcholine. This report indicates that although several plants contain enzymes that are capable of hydrolyzing PNP-PC, this substrate appears to be hydrolyzed by enzymes other than C-type phospholipases.
Coupled light transport-heat diffusion model for laser dosimetry with dynamic optical properties

The effect of dynamic optical properties on the spatial distribution of light in laser therapy is studied via numerical simulations. A two-dimensional, time dependent computer program called LATIS is used. Laser light transport is simulated with a Monte Carlo technique including anisotropic scattering and absorption. Thermal heat transport is calculated with a finite difference algorithm. Material properties are specified on a 2-D mesh and can be arbitrary functions of space and time. Arrhenius rate equations are solved for tissue damage caused by elevated temperatures. Optical properties are functions of tissue damage, as determined by previous measurements. Results are presented for the time variation of the light distribution and damage within the tissue as the optical properties of the tissue are altered.
Electrophysiologic Comparisons Between Two Groups of Patients With Alzheimer's Disease

• Two groups of patients with Alzheimer's disease were compared using brain electrical activity mapping. The patients were selected on the basis of their cognitive history. The initial symptom of disease of the patients in group 1 was a significant and profound memory deficit, whereas the patients in group 2 initially presented with a gradually progressive spatial impairment. Fourteen topographic features distinguished the groups. Eleven of the 14 features pertained to electrical activity differences in parietal regions, and 9 were bilateral. These features were highly correlated with cognitive measures that are also useful in distinguishing the groups.
Development and propagation: A case study of the AIChE concept warehouse

Propagation is a widespread goal of education materials development. If an educational innovation is effective in one environment, many developers want to share it with other instructors and institutions to have a larger impact and improve education more broadly. Studying the propagation process is one way to learn more about the aspects that contribute to propagation of particular educational innovations and aspects that hinder propagation. We report on the early stages of propagation of the Concept Warehouse (CW), a database-driven website developed to support the chemical engineering education community's use of concept-based pedagogies. We hope to inform other developers as well as learn how we can further support propagation of this innovation. Specifically we focus on the propagation strategies used by the developers of the tool and how these strategies have changed over time. We found that the developers focused heavily on creating a network and used workshops as one strategy towards that end. However, not all workshops appeared to have the same effectiveness. Workshops deemed most effective by the developers were those that tied into already existing community networks where the CW portion was part of a longer (multiple day) workshop focused on pedagogy and instruction. Finally, we provide a section with the developers' advice to others who may be considering propagating educational innovations.
How to parameterize models with bursty workloads

Although recent advances in theory indicate that burstiness in the service time process can be handled effectively by queueing models (e.g.,MAP queueing networks [2]), there is a lack of understanding and of practical results on how to perform model parameterization, especially when this parameterization must be derived from limited coarse measurements.We propose a new parameterization methodology based on the index of dispersion of the service process at a server, which is inferred by observing the number of completions within the concatenated busy periods of that server. The index of dispersion together with other measurements that reflect the "estimated" mean and the 95th percentile of service times are used to derive a MAP process that captures well burstiness of the true service process.Detailed experimentation on a TPC-W testbed where all measurements are obtained via a commercially available tool, the HP (Mercury) Diagnostics, shows that the proposed technique offers a simple yet powerful solution to the difficult problem of inferring accurate descriptors of the service time process from coarse measurements. Experimental and model prediction results are in excellent agreement and argue strongly for the effectiveness of the proposed methodology under bursty or simply variable workloads.
Can a Synaptic Signal Arise from Noise

The spontaneous fusion of vesicles at nerve terminals produces random miniature postsynaptic potentials (quantal responses) that are thought to have little functional significance. In this issue of Neuron, Sharma and Vijayaraghavan provide evidence that exogenous signals can accelerate and synchronize the occurrence of quanta strongly enough to activate postsynaptic neurons in what may be a new way to transfer information across synapses.
Thanks God this is not Cancun! Alternative Tourism Imaginaries in Yucatan, Mexico

This paper analyses the role of tourism imaginaries as generative social practices in the production of places as tourist places. This will be accomplished through an ethnographical analysis detailing the production of two distinct alternative tourist imaginaries in the Yucatan Peninsula (Mexico). Firstly, this paper will explore how the ecotourist imaginary of a ‘pristine natural resort’ is performed at the Biosphere Reserve Ria Celestun through very specific tourism practices that veil other tourist uses and alternative imaginaries of the place. Secondly, it will explore how the tourist imaginary of a ‘golden past’ and a ‘taste of luxury’ at Hacienda Temozon Sur is performed through various highly selective material arrangements and practices that veil contemporary social inequalities as well as a problematic past. The detailed analysis of these processes will reveal these alternative tourism imaginaries as powerful forces in the reproduction of contemporary patterns of spatial segregation, social margi...
Early image acquisition using a solid-state cardiac camera for fast myocardial perfusion imaging

Background A novel ultra-fast solid-state cardiac camera (Discovery NM 530c, General Electric) allows much shorter acquisition times compared to standard dual-detector SPECT cameras. This design enables investigation of the potential for early myocardial perfusion imaging (MPI) following a rest injection of technetium-99m (Tc-99m) rather than the conventional 45-60 minute delay in image acquisition.
Effect of early and late exposure to estrual ewes on ram sexual performance classifications.

Abstract This study was conducted to determine whether exposure of ram lambs to estrual ewes during their first autumn and again as adults just before serving capacity tests (SCT) affected the outcome of the sexual performance tests. Treatments were either early exposure of Polypay ram lambs (i.e., 7–8-mo-old rams with ewes for 17 d [n = 30] or no early exposure [n = 30]), and late exposure (i.e., 16–19-mo-old rams with estrual ewes for 3 d) or no exposure to estrual ewes in a 2 × 2 factorial arrangement. Three serving capacity tests were conducted immediately after the early exposure period for individual ram lambs that were exposed to ewes early. Three sham sexual performance tests (i.e., four ram lambs placed in test pens for 30-min without ewes) were conducted with ram lambs that were not exposed to ewes early. All rams were evaluated during nine 30-min serving capacity tests over a 2-mo period at 16–19 mo of age to determine sexual performance. Prior to serving capacity tests, one half of the rams from each early exposure treatment were exposed to estrual-induced ewes for 3 d. Specific sexual behaviors (e.g., sniffs, flehmens, foreleg kicks, vocalizations, mount attempts, mounts, and ejaculations) were recorded during serving capacity tests. Number of sniffs, flehmens, foreleg kicks, vocalizations, and mount attempts were summed without estimating the value of importance and analyzed as courtship behaviors. Sexual performance data were analyzed with Mixed model procedures for repeated measures. During serving capacity tests, the early exposed rams exhibited more courtships (40.3 ± 8.0 versus 23.4 ± 4.6; P
Catecholamine-sensitive adenylate cyclase in the developing golden hamster palate.

The present study was initiated to determine whether specific hormones would influence adenylate cyclase activity within the maxillary-palatal complex during formation of the hamster secondary palate. Stages from initial appearance of the palatal processes to shortly after birth were studied. Highest basal adenylate cyclase activities occurred during the earliest periods of palate development. This basal enzyme activity began to diminish as palatal fusion occurred and remained lowered until birth. Activation of adenylate cyclase by fluoride was maximal at concentrations of 5–10 mM, and was observed throughout the span of palatal development. Fluoride activation of adenylate cyclase was greatest prior to fusion of the palatal processes, then decreased until birth when a slightly increased enzymatic stimulation was seen. Norepinephrine and epinephrine were the catecholamines most capable of inducing increased activation of adenylate cyclase at most periods of palatal growth. Increased enzyme activity in the presence of norepinephrine was more susceptible to antagonism by the beta adrenergic agent, propranolol, than to the alpha adrenergic agent, phentolamine. The remaining catecholamines, namely isoproterenol and dopamine, displayed a lesser ability to activate the enzyme, and adenylate cyclase was not equally responsive to these catecholamines at identical developmental stages. Other hormones, i.e., histamine, serotonin, thyrotropin, growth hormone, thyroxine and glucagon were generally ineffective in activating the enzyme. Phosphodiesterase activity was not detected until shortly before birth.
The Community Profile: A Tool to Improve Economic Competence.

The American political system is an upside down pyramid. Even though the size of the federal government has increased dramatically since the 1930s, most Americans feel a greater emotional attachment to the courthouse than to the White House. Local educational systems frequently oppose federal aid to education because they believe that such a measure may lead to a national curriculum. The battle cry of schools is "grass-roots curriculum!" Ironically, the school systems crying for grass-roots curriculum hope for a miracle to accomplish such a task for them. Most school systems do little or nothing to construct a grass-roots or community-based curriculum. The schools do little or nothing to relate students to their communities so that students may discover for themselves options and niches in their communities.
Evidence for nonreciprocal organization of the mouse auditory thalamocortical-corticothalamic projection systems.

We tested the hypothesis that information is routed from one area of the auditory cortex (AC) to another via the dorsal division of the medial geniculate body (MGBd) by analyzing the degree of reciprocal connectivity between the auditory thalamus and cortex. Biotinylated dextran amine injected into the primary AC (AI) or anterior auditory field (AAF) of mice produced large, “driver-type” terminals primarily in the MGBd, with essentially no such terminals in the ventral MGB (MGBv). In contrast, small, “modulator-type” terminals were found primarily in the MGBv, and this coincided with areas of retrogradely labeled thalamocortical cell bodies. After MGBv injections, anterograde label was observed in layers 4 and 6 of the AI and AAF, which coincided with retrogradely labeled layer 6 cell bodies. After MGBd injections, thalamocortical terminals were seen in layers 1, 4, and 6 of the secondary AC and dorsoposterior AC, which coincided with labeled layer 6 cell bodies. Notably, after MGBd injection, a substantial number of layer 5 cells were labeled in all AC areas, whereas very few were seen after MGBv injection. Further, the degree of anterograde label in layer 4 of cortical columns containing labeled layer 6 cell bodies was greater than in columns containing labeled layer 5 cell bodies. These data suggest that auditory layer 5 corticothalamic projections are targeted to the MGBd in a nonreciprocal fashion and that the MGBd may route this information to the nonprimary AC. J. Comp. Neurol. 507:1209–1227, 2008. © 2008 Wiley-Liss, Inc.
Scatterometer winds explain damped Rossby waves

[1] Westward propagating waves in the North Pacific Ocean from 10–16°N are overwhelmed by a zonally coherent response at the annual period, as observed in sea surface height (SSH) anomalies from the TOPEX/POSEIDON altimeter. SSH from a simple model of wind-forced Rossby waves and from seasonal heating are compared with observed SSH to understand the processes responsible for the observed signal. The seasonal heating cycle is out-of-phase and too weak to explain the SSH. The oceanic response to wind stress curl forcing more closely resembles the observations, but the response to NCEP Reanalysis winds does not show a strong annual cycle. Wind stress curl from the QuikSCAT/SeaWinds scatterometer has a strong and zonally coherent annual cycle that produces a corresonding strong annual signal in SSH. The model forced by scatterometer winds demonstrates that the response to Ekman pumping is the source of the strong annual cycle in the SSH.
Measurement of excited-state absorption cross sections of a novel platinum complex in picosecond top-hat Z-scan experiments employing partially coherent beams

ABSTRACT In top -hat Z scans that employ tunable sources such as optical parametric generators without line- narrowing gratings, the size of the aperture used to clip the beam may exceed the coherence length, and the variation with of the transverse z profile of the resulting partially coherent beam may differ significantly from that of a perfect top-hat beam. After a careful validation of our experimental set-up, we perform picosecond open -aperture Z scans with a top-hat beam at selected wavelengths in the visible and nanosecond open- aperture Z scans with a spatially Gaussian beam at 532-nm wavelength on a toluene solution of a particular platinum(II) -bipyridyl complex bearing  naphthalimidylethynyl-substituted fluo renylacetylide ligands . We report values of the singlet and triplet excited -state absorption cross sections of the complex. Keywords: Z scan, reverse saturable absorption 1. INTRODUCTION Thanks both to their intriguing photophysical properties and to the relative ease with which they can be synthesized and modified, platinum diimine complexes containing bis(arylacetylide) ligands have been the subject of considerable study in recent years.
Sequence of the cDNA for the liver/non-muscle isoform of mouse cytochrome-c oxidase subunit VIII

We have isolated and sequenced the cDNA for the liver (L) or non-muscle isoform of mouse cytochrome-c oxidase subunit VIII (COX VIII-L). Comparison of deduced COX VIII-L protein sequences from three mammalian species indicated that the human gene has sustained more amino acid replacement substitutions than either the mouse or the cow. The most highly conserved regions of this subunit are the N-terminal presequence and the C-terminal domain of the mature protein.
Examining structure and process in ESOP firms

Purpose – To examine the role of three employee‐owner attributes (i.e. the level of employee influence in decision making, the amount of Employee Stock Ownership Plan (ESOP) information given to employee‐owners, and the extent to which the ESOP design provides employee‐owners with equity possession) in predicting variance in managerial perceptions of ESOP firm performance.Design/methodology/approach – Survey responses from management at 61 ESOP firms in the United States are analyzed. Based upon the ESOP literature, “ownership” is conceptualized as a multidimensional construct consisting of rights to influence, information, and equity. This framework is the foundation for several hypotheses linking ownership attributes and firm performance.Findings – Utilizing hierarchical regression analysis, we found that employee influence in operational decisions and information sharing with employee‐owners has a positive impact on managerial perceptions of firm performance. Equity possession appears to be only signif...
Umami: the taste that drives purine intake.

Rheumatologists commonly recommend low purine diets to gouty subjects based on studies linking the purine contents of food to increased risk for gout1. However, most rheumatologists, as well as physicians in general, do not know that one of the basic 5 human tastes is for purine-rich foods, a taste known as umami (oo-mah-mee). We present evidence of this revelation and why this may have occurred. Historically, an elevation in serum urate was considered benign except for carrying an increased risk for gout. Recently, soluble urate has been found to have myriad biologic effects, including raising blood pressure, increasing hepatic fat stores, and inducing insulin resistance2,3. Indeed, the uricase mutation that occurred in the mid-Miocene likely provided a survival advantage to our ancestors during a period of famine that occurred during that time in Europe4. If uric acid has an important role in human survival, then it is logical that there should be a taste receptor that would encourage the ingestion of foods that raise serum urate. In addition to the classic tastes of sour, bitter, sweet, and salt, there is a fifth basic taste, umami. Umami is the “savory” flavor and was first identified in traditional Japanese foods such as kombu (sea kelp), where it was found to result from the presence of free glutamate. The umami receptor in the taste buds is complex, and consists of the metabotropic glutamate receptor-4, the G-protein-coupled heterodimer of taste receptor type 1 member 1 (TAS1R1), and taste receptor type 1 receptor3 … Address correspondence to Dr. R.J. Johnson, Division of Kidney Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado 80045, USA. E-mail: richard.johnson{at}ucdenver.edu
Polymeric systems for amorphous Δ9-tetrahydrocannabinol produced by a hot-melt method. Part I: Chemical and thermal stability during processing

The objective of the present research was to investigate the stability of an amorphous drug, Delta(9)-tetrahydrocannabinol (THC) in polymer-based transmucosal systems. THC was incorporated in polyethylene oxide and hydroxypropylcellulose matrices by a hot-melt fabrication procedure, utilizing various processing aids. The chemical stability of the drug in the polymeric matrices was investigated with respect to processing temperature, processing time, formulation additives, and storage conditions. HPLC analysis of the THC-loaded systems indicated that the extent of drug degradation was influenced by all of the above mentioned variables. THC was particularly unstable in the vitamin E succinate-processed films, indicating a potential incompatibility. Thermal stability of the drug, polymers, and other ingredients at the elevated processing temperatures during the fabrication procedure, was evaluated using the isothermal mode of thermo-gravimetric analysis. When held at 160 and 200 degrees C, the weight percentage of THC decreased linearly as a function of time. Weight loss was controlled by blending the drug with polymers, PEO and HPC, of which PEO was determined to be more effective. Although higher temperatures lowered the polymer melt viscosity, THC and other materials were chemically and thermally unstable at such high temperatures. Due to this, matrix fabrication was found to be favorable at relatively lower temperatures, such as 120 degrees C.
Cyclic di-GMP-dependent Signaling Pathways in the Pathogenic Firmicute Listeria monocytogenes

We characterized key components and major targets of the c-di-GMP signaling pathways in the foodborne pathogen Listeria monocytogenes, identified a new c-di-GMP-inducible exopolysaccharide responsible for motility inhibition, cell aggregation, and enhanced tolerance to disinfectants and desiccation, and provided first insights into the role of c-di-GMP signaling in listerial virulence. Genome-wide genetic and biochemical analyses of c-di-GMP signaling pathways revealed that L. monocytogenes has three GGDEF domain proteins, DgcA (Lmo1911), DgcB (Lmo1912) and DgcC (Lmo2174), that possess diguanylate cyclase activity, and three EAL domain proteins, PdeB (Lmo0131), PdeC (Lmo1914) and PdeD (Lmo0111), that possess c-di-GMP phosphodiesterase activity. Deletion of all phosphodiesterase genes (ΔpdeB/C/D) or expression of a heterologous diguanylate cyclase stimulated production of a previously unknown exopolysaccharide. The synthesis of this exopolysaccharide was attributed to the pssA-E (lmo0527-0531) gene cluster. The last gene of the cluster encodes the fourth listerial GGDEF domain protein, PssE, that functions as an I-site c-di-GMP receptor essential for exopolysaccharide synthesis. The c-di-GMP-inducible exopolysaccharide causes cell aggregation in minimal medium and impairs bacterial migration in semi-solid agar, however, it does not promote biofilm formation on abiotic surfaces. The exopolysaccharide also greatly enhances bacterial tolerance to commonly used disinfectants as well as desiccation, which may contribute to survival of L. monocytogenes on contaminated food products and in food-processing facilities. The exopolysaccharide and another, as yet unknown c-di-GMP-dependent target, drastically decrease listerial invasiveness in enterocytes in vitro, and lower pathogen load in the liver and gallbladder of mice infected via an oral route, which suggests that elevated c-di-GMP levels play an overall negative role in listerial virulence.
Synchronous follicular lymphoma, kaposi sarcoma, and castleman's disease in a HIV-negative patient with EBV and HHV-8 coinfection.

The authors describe the case of a 65-year-old woman who was HIV negative and had a lymph node biopsy that showed concurrent follicular lymphoma (FL; grade 3A), Kaposi sarcoma (KS), and Castleman’s...
Oxyradical scavenging capacity by the S9 fraction of Hexagenia spp. nymphs from the Western Basin of Lake Erie: neutralisation of three potent oxidants

Oxidative stress is a general response of aquatic organisms to environmental contamination. Metals and organic compounds capable of redox cycling cause proliferation of reactive oxygen species (ROS) within organisms. Harm results from ROS-mediated DNA damage, lipid peroxidation, enzyme degradation and compromised intermediary metabolism. Variations in concentrations or activities of antioxidants have been proposed as biomarkers of toxicant-mediated oxidative stress in aquatic organisms. The total oxyradical scavenging capacity (TOSC) assay provides an index of biological resistance to ROS. Burrowing mayflies (Hexagenia spp.) are key indicator species of the health of numerous water bodies, including Lake Erie. TOSC has been used to evaluate the ROS scavenging capacity of tissues from a number of marine and freshwater invertebrates. This is the first study to evaluate ROS scavenging capacity in Hexagenia nymphs. Hexagenia nymphal tissue was homogenised in TRIS buffer containing a protease inhibitor cocktai...
New potential energy surface for H2Br and its use to calculate branching ratios and kinetic isotope effects for the H + HBr reaction

We have carried out multireference configuration interaction calculations with a large basis set for the H[sub 2]Br system at 104 geometries preselected for convenient use in fitting an analytic potential energy surface for the reactions H + HBr [yields] H[sub 2]Br and H + H[prime]Br [yields] H[prime] + HBr. The external part of the correlation energy is scaled (SEC method) to yield a 101 geometry data set which is fitted using the extended London -Eyring-Polanyi-Sato method with bond-distance- and internal-angle-dependent Sato parameters plus a three-center term localized at the colinear H-Br-H saddle point. The unweighted root-mean-square error for 88 points corresponding to collinear and bent H-H-Br geometries and collinear H-Br-H geometries is 0.55 kcal/mol, with larger deviations for bent H-Br-H geometries. Rate constants were calculated by combining the new analytic potential energy surface with improved canonical variational transition state theory and the least-action semiclassical tunneling approximation. For the abstraction reaction, H + HBr [yields] H[sub 2] + Br, and four deuterium and muonium isotopic analogs, agreement with experiment is very good. 87 refs., 11 figs., 30 tabs.
The crystal structure of copper(II) chloride bis(dimethylsulphoxide)

Abstract [(CH 3 ) 2 CuCl 2 belongs to the orthorhombic system, Pnma, with 4 formula groups in a unit cell. The dimensions of the unit cell at 23–24°C are a = 8.0542±0.00013, b = 11.5464±0.0105, c = 11.3670±0.0082A. The calculated density of 1.827 g/cc agrees well with the measured value of 1.83 g/cc. Intensities of 1609 independent reflections were measured by counter using θ–2θ can technique. Refinement of atomic parameters including hydrogen positional parameters has led to a R of 0.075. The crystal structure was determined by the heavy-atom method. It consists of a distorted square planar coordination for copper in which the Cl(1)CuCl(2) angle is 146.13±0.09° and the four bond lengths are: 2.283±0.003A for CuCl(1), 2.290±0.002A for CuCl(2), and 1.955±0.004 A for the two equivalent CuO bonds.
Granular Cell Tumor (Myoblastoma) of the Palpebral Conjunctiva Causing Pseudoepitheliomatous Hyperplasia of the Conjunctival Epithelium

Granular cell tumors rarely occur in the ocular adnexal structures and only three cases have been described in which the eyelid alone was involved. I examined a patient who was, I believe, the first in whom a granular cell tumor appeared clinically as a conjunctival lesion. She was also the first patient with a granular cell tumor of the ocular adnexa to exhibit pseudoepitheliomatous hyperplasia of the overlaying epithelium, a pathologic feature associated with granular cell tumors originating elsewhere in the body.
Insect Tolerant Transgenic Tomato Plants

The structure of an insect control protein gene from Bacillus thuringiensis var. kurstaki HD–1 was determined, and truncated forms of the gene that express a functional insecticidal protein were generated. Two of these truncated genes were incorporated into a plant expression vector for Agrobacterium–mediated transformation. Transgenic tomato plants containing the chimeric genes express the insect control protein gene. Such expression confers tolerance to lepidopteran larvae on the transgenic tomato plants and their progeny. These engineered tomato plants represent a significant step to increased selectivity, specificity and efficiency in insect control.
Hierarchical Mentoring: A Transformative Strategy for Improving Diversity and Retention in Undergraduate STEM Disciplines

In the United States, less than half of the students who enter into science, technology, engineering, and mathematics (STEM) undergraduate curricula as freshmen will actually graduate with a STEM degree. There is even greater disparity in the national STEM graduation rates of students from underrepresented groups with approximately three-fourths of minority students leaving STEM disciplines at the undergraduate level. A host of programs have been designed and implemented to model best practices in retaining students in STEM disciplines. The Howard Hughes Medical Institute (HHMI) Professors Program at Louisiana State University, under leadership of HHMI Professor Isiah M. Warner, represents one of these programs and reports on a mentoring model that addresses the key factors that impact STEM student attrition at the undergraduate level. By integrating mentoring and strategic academic interventions into a structured research program, an innovative model has been developed to guide STEM undergraduate majors in adopting the metacognitive strategies that allow them to excel in their programs of study, as they learn to appreciate and understand science more completely. Comparisons of the persistence of participants and nonparticipants in STEM curricular, at the host university and with other national universities and colleges, show the impact of the model’s salient features on improving STEM retention through graduation for all students, particularly those from underrepresented groups.
Surgical anatomy of dural defects in spontaneous spinal cerebrospinal fluid leaks.

OBJECTIVE: Spontaneous intracranial hypotension is typically caused by a spontaneous spinal cerebrospinal fluid (CSF) leak. The configuration of the related dural defects can be complex. We describe our experience with the surgical anatomy of these defects. METHODS: Thirteen consecutive patients with spontaneous spinal CSF leaks who underwent surgical exploration at Mayo Clinic between 1994 and 2003 were studied. All patients' records, imaging studies, detailed intraoperative findings, and outcomes were reviewed. RESULTS: There were four men and nine women with an average age of 40 years (range, 12-62 yr). Preoperative imaging studies revealed a single site of CSF leak in eight patients, two sites in three patients, and multiple sites in two patients. Intraoperatively, the exact site of leakage could not be found in four patients. Among the other nine patients, primary closure of a meningeal diverticulum was achieved in one patient. Significant regional attenuation of the dura prevented primary repair of the leak site in eight patients. Muscle, fibrin glue, and Gelfoam (Upjohn Co., Kalamazoo, Ml) soaked in patient's own blood were commonly used to pack the epidural space in an attempt to seal the site of the leak. Ligation of two nonappendicular nerve roots allowed closure of the leak in one of these patients. Postoperatively, resolution of symptoms occurred in eight patients, significant improvement was noted in three patients, and only transient resolution in two. The mean duration of follow-up was 20.5 months. CONCLUSION: Surgery for closure of spontaneous spinal CSF leaks may not be straightforward. Even when extradural CSF leakage is discovered preoperatively by imaging studies, it may not always be possible to identify the exact site of the leakage intraoperatively. Furthermore, the anatomy of the dural defects may be complex and not amenable to primary closure. In such cases, the use of adjuvant techniques during surgical exploration may be effective.
The relationship between risk factor levels and presence of coronary artery calcification is dependent on Apolipoprotein E genotype

Abstract—An important research question in the study of the genetics of coronary artery disease (CAD) is whether information about genetic variation will improve our ability to predict CAD beyond established risk factors. This question is especially relevant to the goal of identifying young, asymptomatic adults with coronary atherosclerosis who would benefit most from interventions to reduce risk. Coronary artery calcification (CAC) detected by electron-beam computed tomography is a relatively new method for detecting coronary atherosclerosis in asymptomatic individuals that has been shown to be a more accurate indicator of coronary atherosclerosis in asymptomatic individuals than other noninvasive techniques. In a study of asymptomatic women (n=169) and men (n=160) between the ages of 20 and 59 representative of the Rochester, Minnesota population, we used logistic regression to ask whether the most common Apolipoprotein (Apo) E genotypes (e3/2, e3/3, and e4/3) predict the presence of CAC. The addition o...
Lysosomal Prenylcysteine Lyase Is a FAD-dependent Thioether Oxidase

Prenylated proteins contain either a 15-carbon farnesyl or a 20-carbon geranylgeranyl isoprenoid covalently attached via a thioether bond to a cysteine residue at or near their C terminus. As prenylated proteins comprise up to 2% of the total protein in eukaryotic cells, and the thioether bond is a stable modification, their degradation raises a metabolic challenge to cells. A lysosomal enzyme termed prenylcysteine lyase has been identified that cleaves prenylcysteines to cysteine and an unidentified isoprenoid product. Here we show that the isoprenoid product of prenylcysteine lyase is the C-1 aldehyde of the isoprenoid moiety (farnesal in the case of C-15). The enzyme requires molecular oxygen as a cosubstrate and utilizes a noncovalently bound flavin cofactor in an NAD(P)H-independent manner. Additionally, a stoichiometric amount of hydrogen peroxide is produced during the reaction. These surprising findings indicate that prenylcysteine lyase utilizes a novel oxidative mechanism to cleave thioether bonds and provide insight into the unique role this enzyme plays in the cellular metabolism of prenylcysteines.
The effect of aging resolved chromatophores of Rhodospirillum rubrum on the capacity to reconstitute the energy-linked transhydrogenation.

Abstract Chromatophores which are resolved with respect to energy-linked transhydrogenation can be reconstituted with a soluble transhydrogenase factor. A decrease in the light-stimulated activity is found with transhydrogenase factor of increasing purity while the ATP- and pyrophosphate-driven reactions are maintained at their maximum rate. The inability to fully reconstitute the light-driven transhydrogenase activity has been found to be due to a reversible alteration within the resolved chromatophore membrane. Evidence is presented which leads to the postulate that the aging process damages those membrane sites which involve non-cyclic electron transport, are not associated with phosphorylation, and are involved in driving 50 % of the light-dependent transhydrogenation.
Interventions to enhance cancer screening: A brief review of what works and what is on the horizon

Although major advances have been made in the proportion of women who have been screened for breast and cervical cancer, there are still large numbers of women who are not being screened on schedule. This article includes a very selective review of types of interventions that have been used to increase cancer screening. These include the following kinds of interventions: mass media, patient-directed, provider- and system-directed, access-enhancing, community-directed, policy level, and multilevel interventions. Several different kinds of interventions have been used to increase cancer screening. The most extensive research has been conducted in the areas of breast and cervical cancer screening. Some relatively simple and inexpensive interventions have been shown to double or triple the odds that women will get screened; these include simple reminder letters or cards and telephone counseling. Tailored interventions are a new area and hold promise. Some studies have shown the value of access-enhancing strategies, such as the use of mobile vans. Policy changes are necessary but are not sufficient to increase the use of screening. One of the challenges for the future is to reach the groups in the population that have remained resistant to screening despite numerous messages in the mass media. The interventions of the future should reflect what has been learned in the past, such as the importance of reminders and cues to screening and overcoming women's barriers through strategies, such as counseling. However, tomorrow's interventions also should take advantage of digital technology and other advances in communications, and interventions should be tailored to the special needs of individuals in ways that are responsive to their learning preferences, situational constraints, and life styles. Far more research is needed to address the heterogeneity of minority populations in the United States and elsewhere. At present, it is not known to what extent interventions tested among black populations will extend to other minorities.
A Noninvasive Radiographic Technique for Evaluation of Exercise-Induced Changes in Cardiac Function

An electrocardiographic-triggered radiographic technique for obtaining a single image of the heart at both end-systole and end-diastole was used in conjunction with upright bicycle exercise to detect stress-induced changes in 1) systolic and diastolic cardiac transverse diameter, and 2) regional motion of the free left ventricular wall. Twenty-one patients were studied; 10 had normal coronary arteries and 11 had significant coronary artery disease. Twenty patients (10 with normal coronary arteries and 10 with coronary artery disease) also had multigated radionuclide blood pool scans at rest and with exercise. All patients without coronary disease showed a decrease in systolic cardiac transverse diameter with exercise and a slight increase in amplitude of motion of the left ventricular free wall. Eight (73%) of the 11 patients with coronary artery disease showed an increase in systolic transverse cardiac diameter with exercise (p This new approach is inexpensive and easily performed. These preliminary data suggest that it may be a useful adjunct to cardiac stress testing and is worthy of further study.
Few transcribed RNAs are translated in avian erythroid cells.

Abstract To assess the contribution of posttranscriptional sequence selection to gene regulation, we have compared the sequence complexity of messenger RNA (mRNA) and heterogeneous nuclear RNA (hnRNA) in immature circulating erythroid cells from chickens with induced anemia. Poly(A)+ mRNA was isolated from EDTA-dissociated polysomes and was transcribed into complementary DNA (cDNA). Analysis of the hybridization kinetics of mRNA to cDNA indicated that about 90% of the mRNA has a sequence complexity of 1700 NT, corresponding to the three species of adult chicken globin mRNA. cDNA was enriched for nonglobin sequences by hybridization to excess globin mRNA and hydroxyapatite chromatography. Analysis of the kinetics of hybridization of the enriched nonglobin cDNA to total mRNA indicates that the mRNA of these cells contains about 100 nonglobin mRNA species, each present at about 1 200 the concentration of globin mRNA. Poly(A)+ hnRNA was isolated from detergent-washed nuclei and transcribed into cDNA. Analysis of the hybridization kinetics of hnRNA to cDNA revealed two kinetic components, one having a sequence complexity of about 3 × 104 NT and the other about 5 × 106 NT. The total sequence complexity of poly(A)+ hnRNA is thus about 45 times that of poly(A)+ mRNA. We conclude that not all poly(A)+ hnRNA serves as precursor to mRNA in avian erythroid cells. We suggest that both selective transcription and posttranscriptional sequence selection contribute to the specialization of erythroid cells during terminal differentiation.
Measurement and the stress process: Retrospect and prospect

An overview of papers on measurement issues in research on stress suggests a number of common themes that characterize the current status of, and probable future directions for measurement of the stress process. More general issues relate to (1) the development of valid and reliable measures of theoretically differentiated constructs, and (2) the simultaneous measurement of the differentiated constructs in the estimation of theoretically informed multivariate causal models. These and other measurement issues have been related more specifically to particular explanatory constructs including vulnerability, life events, chronic role strains, evaluative significance, coping mechanisms, and stressful outcomes. Success in resolving these issues will determine in large measure progress of the research enterprise in increasing understanding of the press process.
IN SITU GENERATION OF PSORALENS BY PHOTOLYSIS OF WATER‐SOLDBLE PRECURSORS

— The poor water solubility of typical photochemotherapeutic psoralens restricts their utility in aqueous solutions and commonly requires the use of organic co-solvents in photobiological studies. This paper describes the preparation of readily water-soluble “pre-psoralens”, (Z)-3-[5-(4,6-dimethoxy)benzofuranyl]propenoic acid (3) and (Z)-3-[5-(6,7-dimethoxy)benzofuranyl]propenoic acid (4), and their novel photocyclization in aqueous media to give 5-methoxypsoralen (5-MOP) and 8-methoxypsoralen (8-MOP), respectively. Quantum efficiencies, measured at 308 nm for the cyclization, are 12. 1 × 10-3 for 3 5-MOP and 2.7 × 10-3 for 4 8-MOP. 5-Methoxyisopsoralen (5-MOiP, 5) is a side product from the photolysis of 3. Photocross-linking of calf thymus DNA is effected when the “pre-psoralens” are irradiated with 308 or 355 nm (3 only) light.
Positive streamer system intensification and its possible role in lightning initiation

Abstract Experiments are described in which positive streamers propagate within a uniform field region having an applied electric field greater than the minimum value needed to cause streamers to bridge the interelectrode gap. Under these conditions exponential intensification of the streamer system is observed, accompanied by negative charge deposition along the channels. These results are shown to be a direct consequence of energy and charge conservation for the streamer system when individual streamers are treated as isolated propagating space charge pulses. The formation of a stepped leader via this process is discussed.
Microcomputer analysis and management of residency training experiences.

Abstract A rapid interactive microcomputer system is described that utilizes MUMPS language programs for assessing and managing a residency program's outpatient experiences for its trainees.
Biogeochemical prospecting for copper and zinc using Juniperus virginiana L.

Abstract A biogeochemical investigation was made of Juniperus virginiana L. around an area of known copper mineralization in St. Genevieve County in southeastern Missouri. Cu, Zn, Fe, Mn, Ni, Co, and Pb contents of plant ash were measured by atomic absorption spectrophotometry. A cluster diagram based on statistically significant correlation coefficients was used to distinguish between soil and mineralization-related elemental associations. Cu, Zn, Fe and Co are inferred to be related to mineralization whereas a Pb, Fe, and Zn association is related to residual soil developed on the carbonate host rock. The two associations appear to be gradational. Cu content of the ash had an approximately normal frequency distribution. A pronounced break in the slope of the cumulative frequency plot indicates that values greater than one positive standard deviation can be considered anomalous. Direct map plots of the data showed anomalous values to be erratic, so an averaging technique was used to define “map anomalies”. The averaged values correspond well to areas of known mineralization. From the map plots of Cu, Zn and Co, an extension of mineralization was inferred uphill and slightly higher startigraphically. An example of negative correlation of Cu to availability was observed for Quercus rubra L.
Evaluation of the fracture toughness of Nb-40Al-8Cr-1W-1Y-0.05B intermetallic material by indentation techniques

The fracture toughness of an Nb-40Al-8Cr - 1W-1Y-0.05B intermetallic material was evaluated by indentation techniques at room temperature. Two widely used indentation methods, crack size measurement and indent strength, yielded excellent agreement with a conventional fracture toughness technique using straight-through precracked specimens, despite the occasional formation of poorly configured cracks. However, the modified indentation technique, using dummy indent flaws, resulted in a low fracture toughness compared to that evaluated by the other methods. The material did not exhibit rising R-curve behavior, as evaluated from the indentation strength data. These results indicate that indentation fracture principles are applicable to this brittle intermetallic material without modification of the residual contact stress term originally calibrated for ceramic materials.
Cryptoexplosive structure near Wetumpka, Alabama

A Cryptoexplosive structure that probably resulted from a meteorite impact is located near Wetumpka, Alabama (long 32°31′42″N, lat 86°14′12″W), along the boundary between the Gulf Coastal Plain and the Piedmont physiographic provinces. Its main features are (1) an approximately concentric structural system about 6.5 km in diameter, its rim formed by metamorphic rocks and surrounded by Cretaceous sedimentary rocks; (2) an arcuate ridge of schist extending two-thirds of the way around the structure, which stands 60 to 150 m above the adjacent Piedmont peneplain; (3) the chaotic orientation of Cretaceous and metamorphic units in the center of the structure, perhaps corresponding to the central rebound area; (4) concentric marginal faults with an estimated displacement of 240 to 300 m; and (5) shock effects in feldspar and quartz crystals in rock units that form the rim. A southward-sloping metamorphic rock surface and a northward-thinning Cretaceous cover afforded a unique geologic setting for the formation and possible preservation of the structure. A shallow marine setting may best explain the shape and distribution of rocks. Nowhere else along the 1,600 km of Coastal Plain—Piedmont boundary is there any faulting of the magnitude described in this report. The age of the Wetumpka Cryptoexplosive structure is post-Mooreville (Late Cretaceous) and pre-terrace (Pleistocene?). The name “Wetumpka Astrobleme” is proposed for this structure.