cssi/SciSciGPT-SciSciNet huggingface dataset:
Torsional Behavior of Nucleosome Arrays

Genomic DNA is subjected to strong torsional stresses during processes like transcription and replication. Emerging evidence suggests that such torsional stresses might serve critical functions in the cell nucleus. Most experimental and theoretical work so far has focused on understanding the supercoiling of the naked DNA, but little is known about how torsional stresses are stored, propagated, and relieved within the chromatin fiber. Here we investigate the torsional behavior of nucleosome arrays by using Brownian dynamics simulations of a coarse-grained model of chromatin fiber. By rotating one end of the array in a step-wise manner while keeping the other end fixed, we measure the equilibrium extension of the array as a function of the applied twist. The measured twist-extension profiles display an asymmetry shape with a shifted maximal extension. The magnitude and sign of the observed shift depends strongly on the internucleosomal “phase” angle resulting from the helical twist of the linker DNA. Moreover, moderate values of the phase angle lead to broad plateau at the maxima in the twist-extension plots while extreme values of the angle lead to sharper maxima. By tracing different nucleosome states in the rotations, we show that the plateau results from a conformational transition between open and negatively crossed states of individual nucleosomes with a minimal twisting energy cost, explaining high torsional resilience of the array. Indeed, the torsional rigidity of the array extracted from twisting energies is significantly smaller than that of naked DNA. Finally, we construct the kymograph of rotational autocorrelation function for each segment of the array, which clearly visualizes the effect of phase angle on the propagation of twist. This work provides one of the first detailed pictures of supercoiled chromatin and how eukaryotic DNA might relieve its torsional stresses through conformational transitions in the nucleosome.
MO-E-L100J-06: Slot Scan Imaging with a High Frame Rate Flat Panel Detector-Measurement and Correction for In-Slot Scatter

Purpose: To report on the use of a new scatter measurement technique to characterize the scatter rejection properties and to further correct for the in‐slot scatter in slot scan imaging with a high frame rate flat panel detector.Method and Materials: A new slot scan imaging technique was developed with a high frame rate (7.5 fps) flat panel detector. 300 images were acquired as an x‐ray fan beam, defined by a slot collimator placed in front of the tube, was scanned across an anthropomorphic chest phantom. Time‐intensity curves were formed from the image sequence for all pixels. They were integrated over the fan beam passing frames to form the scatter rejected image signals and over all frames to form the open field image signals. By assuming the primary component to be constant during the fan beam exposure, the scatter components were extracted from the time‐intensity curves to estimate the in‐slot scatter using an iterative background estimation algorithm. The results were used to measure the scatter signals and to correct for in‐slot scatter. Results: Slot scan images of an anthropomorphic chest phantom were acquired and formed for various projected fan beam widths. 2D maps of scatter‐to‐primary ratios and contrast‐to‐noise ratio (CNR) improvement factors were generated and plotted for the slot‐scan images and compared with those for the full field, non‐grided images . In the lungs, CNR was improved by 30 to 50%, and in the mediastinum, CNR was improved by 60 to 150%. Conclusion: We have described and demonstrated the use of a new scatter measurement technique to estimate and correct for the in‐slot scatter on a pixel‐by‐pixel basis in slot scan imaging with a high frame rate flat panel detector. This work was supported in part by research grants EB00117 from the NIH‐NIBIB and CA51248 and CA104759 from the NIH‐NCI.
Using a Three-Dimensional Virtual Platform to Teach the Pterygopalatine Fossa

Virtual world technology was used to create 3D anatomy models of the pterygopalatine fossa, including a basic cone model that illustrates the boundaries and transmitted nerves and an organic model that displays the nerves in context with surrounding bones. The design and implementation of the virtual models are discussed here.
Mass-Marking Otoliths of Larval and Juvenile Walleyes by Immersion in Oxytetracycline, Calcein, or Calcein Blue

Abstract Immersion of larval and juvenile walleyes Stizostedion vitreum for 6 h in a 500-mg/L solution of oxytetracycline hydrochloride or Calcein resulted in fluorescent marks on 100% of the otoliths. Few marked fish (≤27.0%) were found after immersion in Calcein blue, Immersion of larvae at 15°C resulted in significantly higher mortality (57.7%) than at 10°C (20.9%). Mortality at 10°C was lowest for larvae immersed in oxytetracycline (9.0%) and greatest for those immersed in Calcein (41.6%). Juvenile mortality (1.3–32.7%) was correlated with high pond water temperatures during June (26.1°C) and August (32.2°C). All of the juveniles survived when immersed in any of the three chemicals in cases where pond water temperatures were less than 20°C at the time of collection.
Meta-analysis of the effects of psychoeducational care in adults with asthma

Meta-analysis was conducted with 31 studies published between 1972 to 1993 on the effect of psychoeducational care (education, behavioral skill development, cognitive therapy, and/or nonbehavioral support/counseling) in adults with asthma. Fifty-eight percent of studies had subjects that were randomly assigned to treatment condition. Statistically significant beneficial effects were obtained on the occurance of asthmatic attacks (d+ = .56, n = 11), dynamic respiratory volume (d+ = .34, n = 10), peak expiratory flow rate (d+ = .29, n = 6), functional status (d+ = .46, n = 4), adherence to treatment regime (d+ = .78, n = 7), utilization of health care (d+ = .29, n = 10), use of PRN medications (d+ = .62, n = 8), psychological well-being (d+ = .53, n = 6), and psychomotor knowledge of inhaler use (d+ = 1.02, n = 4). Methodological weaknesses were identified that should be rectified in future research. Nonetheless, based on the best evidence available to date, both education and relaxation-based behavioral interventions have been shown to improve important clinical outcomes in adults with asthma.
The Soil Health-Human Health Nexus

Soils can beneficially or adversely affect human health, and likewise human activity can improve or destroy soil health. In the new anthropogenic era, it is worth examining the soil health–human health nexus. To do this, the author evaluates soil from the perspective of what infects us, what heals us, what contaminates us, what nourishes us, and what we breathe. Likewise, the author examines the impact of humans on soil using a similar matrix and suggests strategies to improve human health by maintaining or improving soil health.
A note on the paper by Murat Cenk and Ferruh Ozbudak “Multiplication of polynomials modulo xn”, Theoret. Comput. Sci. 412 (2011) 3451-3462

We recall some bibliography on fast polynomial multiplication related to the recent progress in the paper by Cenk and Ozbudak of 2011.
EFFECTS OF SULFHYDRYL REAGENTS ON THE REGULATION OF CYTOSOLIC PH IN RAT SUBLINGUAL ACINI

The effects of sulfhydryl (SH) reagents on the regulation of cytosolic pH (pH,) in rat sublingual mucous acini were examined using the pH-sensitive dye 2',7'- biscarboxyethyl-5(6)-carboxyfluoresceln (BCECF). The membrane permeable SH re- agent N-ethylmaleimide (NEM) resulted in a cytosolic acidification (0.19 f 0.02 pH unit after 5-min treatment). In contrast, the impermeable SH reagents 5,5'-dithiobis(2-nitro- benzoic acid) (DTNB), p-chloromercuribenzoic acid (PCMB) and Cu2+ did not affect the resting pH,. Muscarinic stimulation with carbachol (CCh) induced a cytosolic acid- ification (0.15 & 0.01 pH unit after 5 min). Cu2+ enhanced the CCh-stimulated acidifi- cation 2-fold (0.30 f 0.02 pH unit after 5 min). Preincubation with SH reducing agent dithiothreitol (DTT) prevented the NEM-induced and Cu2+-enhanced pH, decreases. The Cu2+-enhanced but not the NEM-induced acidifications were reversed by addition of Dll after stimulation. Na+/H+ exchange was not influenced by Cu2+ or NEM, sug- gesting that the SH reagent-induced acidification is not caused by inhibition of ex- changer activity. Anion channel inhibitor diphenylamine-Bcarboxylate (DPC) abol- ished the NEM-induced and the Cu2+-enhanced acidifications, suggesting that the acidification was mediated by HC03- efflux via anion channels. Cu2+ did not affect the CCh-evoked increase in cytosolic free Ca2+ concentration ((Ca2+),). In contrast, NEM triggered an elevation in (Ca2+),, and Dll completely prevented this increase. The CCH-stimulated (Ca2+), increases were prevented by blocking Ca2+ release from the intracellular pool with 8-(diethylamino)-octyI-3,4,5-trimethoxybenzoate (TMBd), and the NEM-stimulated (Ca2+), increases were abolished by chelating cytosolic Ca2+ with bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA). TMB-8 prevented the CCh-stimulated, but not the Cu2+-enhanced pH, decrease, and the NEM-induced pH, decrease was not blocked by BAPTA, Suggesting that the effects of Cu2+ and NEM on anion channels are independent of Ca2+. Taken together, these results indicate that SH groups play a critical role in pH, regulation and the reactive SH groups are probably located on cytoplasmic site@) of anion channels or an associated regulatory protein. (P.S.E.B.M. 1996, Vol 21 11
Progression of atherosclerosis as assessed by carotid intima-media thickness in patients with HIV infection.

Background— HIV-infected patients may be at increased risk for coronary events. The purpose of this study was to identify predictors of carotid intima-media thickness (IMT) in HIV patients at baseline and to measure IMT progression over 1 year. Methods and Results— We measured blood lipids, inflammatory markers, and IMT in 148 HIV-infected adults (mean age, 45±8 years) and in 63 age- and sex-matched HIV-uninfected control subjects. The mean duration of HIV infection was 11 years, and the median duration of protease inhibitor treatment was 3.3 years. Mean baseline IMT was 0.91±0.33 mm in HIV patients and 0.74±0.17 mm in control subjects (P=0.0001). Multivariable predictors of baseline IMT in HIV patients were age (P<0.001), LDL cholesterol (P<0.001), cigarette pack-years (P=0.005), Latino race (P=0.062), and hypertension (P=0.074). When the control group was added to the analysis, HIV infection was an independent predictor of IMT (P=0.001). The rate of progression among the 121 HIV patients with a repeated...
Concurrent and predictive validity of the WISC-R, McCarthy Scales, Woodcock-Johnson, and academic achievement†

Twenty-six normal first-grade children (M = 7.0 years) were administered the WISC-R, the McCarthy Scales, and the Woodcock-Johnson Scales of Cognitive Ability. Two years later, their levels of academic achievement were determined by way of the WRAT and global teacher ratings of classroom performance. Pearson intercorrelations among the summary indices of the three intellectual measures were significant and uniformly high (rang. 77-.95). Correlations between first-grade ability scores and third-grade achievement measures also were significant (range .64-.90), suggesting strong predictive validity for each of the cognitive instruments. Though not significantly so, the correlations between the Woodcock-Johnson and achievement tended to be the highest. The results indicate that all three intellectual measures are appropriate for predicting later academic achievement in young school-aged children.
Internal consistency reliability of the tactual performance test trials.

Internal consistency reliabilities were calculated for the Tactual Performance Test Preferred Hand (n=300), Nonpreferred H and (n=302), and Both Hands (n=314) trials, and Total Time. Reliabilities are reported for the total sample and three groups: normal, undiagnosed patients sent for assessment, and alcoholic persons. The reliability coefficients ranged from .59 to .90.
Prediction of patient outcome in pathologic stage T2 adenocarcinoma of the prostate : Lack of significance for microvessel density analysis

Abstract Objectives. Some patients with palpable intermediate- and high-grade, margin-free, organ-confined prostate cancer experience recurrence following prostatectomy. We studied the ability of microvessel density and other factors to predict recurrence in such patients with pathologic Stage T2 cancer. Methods. Between 1987 and 1991, 307 patients underwent radical prostatectomy for Gleason score 6 to 9, margin-free, organ-confined prostate cancer at Mayo Clinic, Rochester, Minnesota. Specimens from 147 patients with sufficient cancer tissue for immunohistochemical staining with Factor VIII-related antigen were studied by computer-assisted digital image analysis for optimized microvessel density (OMVD). The correlation of deoxyribonucleic acid (DNA) ploidy, Gleason score, OMVD, unilateral disease, bilateral disease, and preoperative prostate-specific antigen (PSA) to cancer recurrence was assessed using the Cox model. Biochemical recurrence was defined as postoperative increase in PSA of greater than 0.2 ng/mL, and clinical recurrence was defined as positive biopsy or metastasis on bone scan. Results. Mean follow-up for all patients was 6.1 years, with 12 deaths (1 due to prostate cancer) and 58 cases of clinical and/or biochemical recurrence. OMVD was not significantly associated with DNA ploidy, Gleason grade, unilateral disease, bilateral disease, or preoperative PSA. Preoperative PSA was the strongest predictor of clinical and/or biochemical recurrence in both univariate and multivariate analysis. OMVD was not a significant univariate or multivariate predictor of clinical and/or biochemical recurrence. The estimated relative risk of clinical and biochemical recurrence associated with a change in OMVD from the 25th percentile (OMVD 45) to the 75th percentile (OMVD 84) was 1.08 (95% confidence interval 0.79 to 1.47). Conclusions. Preoperative PSA was the strongest predictor of clinical and/or biochemical recurrence of prostate cancer in this group of patients. Optimized microvessel density did not predict outcome in a select cohort of patients with palpable intermediate- and high-grade, margin-free, organ-confined prostate cancer (TNM stage T2N0M0).
Waves of Creative Destruction : Firm-Specific Learning-by-Doing and the Dynamics of Innovation

This paper develops a model of repeated innovation with knowledge spillovers. The model's novel feature is that firms compete on two dimensions: (1) product quality, where one firm's innovation ultimately spills over to other firms; and (2) distribution costs, where there are no spillovers across firms and where learning-by-doing on the part of incumbent firms gives them a competitive advantage over would-be entrants. Such firm-specific learning-by-doing has two important consequences: (1) it can in some circumstances dramatically reduce the long-run average level of innovation; (2) it leads to endogeneous bunching, or waves, in innovative activity.
A Mystery Wrapped in an Enigma: Matrigel Enhancement of Mammary Cell Growth and Morphogenesis

The analysis of normal mammary morphogenesis is facilitated by the use of mammary fat pad transplantation. The recent experiments on analysis of normal mammary epithelial stem cell activity rely heavily on this technique. In this review, we discuss the known and unknown attributes of using Matrigel in the injection of the mammary epithelial cell suspension. Matrigel greatly increases the "take" frequency of the injected cell suspension; however, there is some uncertainty regarding the interpretation of some of the results. After consideration of these issues, our conclusion is that Matrigel is important in order to obtain rigorous and reproducible results.
Elevated troponin levels in previously healthy children: value of diagnostic modalities and the importance of a drug screen.

Background: Myocardial injury in previously healthy children is rare, with a wide range of aetiologies. It is increasingly being identified on the basis of elevated troponin levels during routine evaluation of cardiorespiratory symptoms. Establishing the aetiology remains challenging because of the lack of an accepted work-up algorithm. Our objective was to delineate the contribution of diagnostic modalities and troponin patterns towards the final diagnosis. Methods: A retrospective chart review of previously healthy patients admitted to the Pediatric Cardiology Service with myocardial injury was carried out. Data analysed included echocardiograms, electrocardiograms, cardiac catheterisations, magnetic resonance imaging, drug screen tests, troponin values, and final diagnosis. Results: A total of 32 patients were identified. The diagnoses were: myocarditis in 16 patients, vasospasm due to drug use in seven, myopericarditis in six, anomalous coronary artery origins in two, and Prinzmetal's angina in one patient. The electrocardiograms were abnormal in 27 of the 32 patients (84%), echocardiograms in 18 of the 32 patients (56%), cardiac magnetic resonance imaging in two of the four patients (50%), urine drug screen in five of the 25 patients (20%), and cardiac catheterisations in two of the 15 patients (13%). Conclusions: Myocarditis is the most common aetiology of myocardial injury in children. Clinical history remains the basic screening tool; drug screens help identify coronary vasospasms secondary to drug use (22% of our cohort). Patients with anomalous coronaries had exertional symptoms. Initial troponin levels and progression were not diagnostic or prognostic. Catheterisation is of limited value and did not change management. Magnetic resonance imaging with gadolinium enhancement is probably the most useful test when initial evaluation is not diagnostic.
c-Fos expression in female hamster brain following sexual and aggressive behaviors

The goal of these experiments was to use c-Fos immunocytochemistry to determine areas of the female hamster brain that are active during lordosis and aggression. Ovariectomized hamsters were given (i) estradiol and progesterone, plus a lordosis test, (ii) estradiol and progesterone, but no lordosis test, (iii) oil, plus an aggressive behavior test, or (iv) oil, but no behavior test. Results showed that following lordosis, there was increased c-Fos expression in the medial bed nucleus of the stria terminalis, medial accumbens, medial preoptic nucleus, paraventricular nucleus and medial amygdala. Following a single aggression test, c-Fos was significantly increased only within the medial amygdala. There was no effect of lordosis or aggression on c-Fos expression within the lateral or central ventromedial hypothalamus, suprachiasmatic nucleus or dorsal midbrain central gray. In a second experiment, ovariectomized female hamsters were given (i) repeated aggressive experience, (ii) a single aggression test or (iii) no aggression test. Because some females were not aggressive towards males, they became a separate group post hoc. The number of cells expressing c-Fos was higher in the medial preoptic nucleus and medial amygdala of females given a single aggressive test and in non-aggressive females vs control females. Females given prior aggressive experience showed higher c-Fos expression only in the medial preoptic nucleus. These results demonstrate that increased neural activation in several forebrain nuclei is seen after sexual or aggressive behaviors in female hamsters. However, because the pattern of c-Fos staining in the non-aggressive females was similar to the pattern in aggressive females, this questions previous conclusions regarding the behavioral specificity of these effects and suggests instead that such activation is common to social interactions in general.
The influence of storage conditions on physical and physiological characteristics of Shepody potatoesa

The influence of storage temperature (pre-storage, 3 °C, 7 °C, and 9 °C) and controlled atmospheric (CA) conditions (7 °C, 2% O2, 10% CO2) were evaluated relative to the physiology and mechanical failure properties of potato tubers (Solarium tuberosum L. cv. Shepody). Mechanical properties of the tuber tissue differed by storage treatment although the physical properties could be generally explained by the measured relative turgor of the tissue. Models typically ascribe lower tissue toughness to greater tissue turgor. In this study, prior to storage tubers exhibited characteristics of greater tissue toughness (20.3 MPa) in conjunction with high relative tissue turgor (as measured by shock wave speed, 115 m/s). It appears that tubers prior to storage have quantitatively stronger tissue compared to tubers after storage regardless of hydration level. CA storage altered tissue mechanical properties as well as carbohydrate content and had physiochemical characteristics of tubers stored at 3 °C;.
Lead is where you find it.

Some topics discussed are as follows: screening programs for symptomatic childhood lead poisoning in urban and rural areas of the United States; elevated blood levels of lead in children living in older, deteriorating housing; sources of lead such as peeling, lead-laden paint, burning lead batteries, and fruit juice stored in improperly glazed earthenware; exposure to lead from automobile exhaust and industrial pollution; relation of blood level of lead to absorption and toxicity; use of erythrocyte protoporphyrin measurements to evaluate children for lead poisoning; and learning and behavioral disturbances following exposure to lead during childhood. (HLW)
Rate of Occult Specimen Provenance Complications in Routine Clinical Practice

Occult specimen provenance complications (SPCs), which occur when there is an absence of any direct or indirect indication that a specimen switch or contamination may have occurred, constitute a significant patient safety and medical-legal problem because they can lead to misdiagnosis. However, the rate at which occult SPCs occur is unknown because, by definition, this category of errors is not identified by standard laboratory practices. In this study, we evaluated a data set comprising almost 13,000 prostate biopsies that were prospectively tested for specimen provenance errors as part of routine clinical practice. The frequency of occult type 1 errors (a complete transposition between patients) and type 2 errors (contamination of the patient’s tissue with 1 or more unrelated patients) was 0.26% and 0.67%, respectively; every urology practice setting and surgical pathology laboratory type with a representative sample size experienced at least 1 type 1 and 1 type 2 error during the study period. Overall, the mean frequency of SPCs across practice settings was 0.22% for type 1 errors and 1.69% for type 2 errors. The type 1 rate showed no correlation with a surgical pathology laboratory setting or urologic practice group setting; the type 2 rate correlated solely with a surgical pathology laboratory setting. The occult SPC rate in this limited data set provides an estimate of the scope of the problem of potential misdiagnosis as a result of occult specimen provenance errors in routine clinical practice.
Abstract A53: Tumor suppressor microRNA miR‐34 inhibits human pancreatic and gastric cancer stem cells

MicroRNAs (miRNAs) have been implicated in cancer initiation and progression via their ability to affect expression of genes and proteins that regulate cell proliferation and/or cell death. Transcription of the three miRNA miR‐34 family members was recently found to be directly regulated by p53. Among the target proteins regulated by miR‐34 are Notch and Bcl‐2, suggesting the possibility of a role for miR‐34 in the maintenance and survival of cancer stem cells. We examined the roles of miR‐34 in p53‐mutant human pancreatic and gastric cancer cell lines and the potential link to cancer stem cells. Restoration of miR‐34 expression in the cancer cells by miR‐34 mimics or lentiviral miR‐34 downregulated Bcl‐2 and Notch1/2. miR‐34 restoration significantly inhibited clonogenic cell growth and invasion, induced apoptosis and G1 and G2/M arrest in cell cycle, and sensitized the cancer cells to chemotherapy and radiation. We identified that CD44+/CD133+ cancer cells are enriched with tumorsphere‐forming and tumor‐initiating cells or cancer stem/progenitor cells with high levels of Notch/Bcl‐2 and loss of miR‐34. More significantly, miR‐34 restoration led to a significant reduction of the tumor‐initiating cell population, accompanied by significant inhibition of tumorsphere growth in vitro and tumor formation in vivo. Our results demonstrate that miR‐34 may restore, at least in part, the tumor suppressing function of the p53 in p53‐deficient human pancreatic and gastric cancer cells. Our data support that miR‐34 may be involved in cancer stem cell self‐renewal, potentially via the direct modulation of downstream targets Bcl‐2 and Notch, implying that miR‐34 may play an important role in cancer stem cell self‐renewal and/or cell fate determination. Currently, we are exploring the nanoparticle‐targeted delivery of miR‐34 to cancer stem cells as a novel molecular therapy for human pancreatic/gastric cancer, based on our patented nanobiotechnology which has been approved by FDA for clinical trials. Taken together, our results demonstrate that restoration of miR‐34 may hold significant promise as a novel molecular therapy for human pancreatic/gastric cancer with loss of p53‐miR34, potentially via inhibiting cancer stem cells. The project is funded by NIH grants CA121830, CA128220 and CA134655 (to L. Xu.). Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A53.
Recurrence of preterm premature rupture of membranes in relation to interval between pregnancies

Objective The purpose of this study was to examine whether the recurrence risk of preterm premature rupture of membranes (PPROM) is modified by the interpregnancy interval (IPI). Study Design We used the Missouri 1989–1997 longitudinally linked data to examine the recurrence risk of PPROM in women with first 2 (n = 150,929) and first 3 (n = 30,011) successive pregnancies. Race-specific recurrence risks were examined. Adjusted odds ratios (ORs) were used to estimate risks. Results Risks of PPROM in the second pregnancy among women with and without previous PPROM were 5.7% and 2.3%, respectively, among white women (OR, 8.7; 95% confidence interval, 6.7–11.4) and 10.3% and 4.3%, respectively, among African American women (OR, 7.2; 95% confidence interval, 5.1–10.1). Short IPI was associated with increased risk for PPROM recurrence, with substantially higher risk for African American women than white women. However, long IPI was associated with increased recurrence among African American women. Conclusion Women with previous PPROM are at increased risk for recurrence, and a short IPI is associated with increased risk.
Comments on "Second-order n -dimensional systems and the Lyapunov matrix equation

The procedure of the above-mentioned correspondence item must be supplemented by additional algebraic equations to determine the required Lyapunov function uniquely.
Novel method for the labeling of distant neuromuscular junctions.

Essential to understanding the roles proteins and structural elements play at the synapse is to understand the development, remodeling and reinnervation of peripheral neuromuscular junctions. It has, however, been a challenging task to label and visualize neuromuscular junctions. In this paper we demonstrate how adenovirus technology can be combined with intraspinal microinjection techniques to follow both the development and the reinnervation of a distant peripheral neuromuscular junction in the rat. A recombinant adenovirus containing VAMP-2 (synaptobrevin-2) was fused to the green fluorescent protein (GFP) and microinjected into the region of the lumbar motor neurons. We were able to follow the neuronal incorporation, axonal transport and synaptic localization of the GFP-VAMP-2 using fluorescence microscopy. GFP-VAMP-2 was found in neuronal cell bodies, selected sciatic nerve axons and was concentrated in the presynaptic nerve terminal. During reinnervation of the neuromuscular junction, GFP-VAMP-2 allows us to follow the time course of junctional reinnervation. Thus, the microinjection of microliter amounts of labeled recombinant virus into locations far distant from target regions can be used to efficiently study the formation of neuromuscular junctions with a minimum of trauma to the animal.
A critical test of the usefulness of simons type model potentials in molecular calculations

Abstract Simons type pseudopotentials were employed in extended basis set calculations of Li+2, Na+2 and K+2, using 1s, 2s, 3s and 2pσ functions on each center. Calculations of this type give inaccurate results because the pseudopotential is too repulsive in the atomic valence region. These results clearly show that Simons type pseudopotentials are not useful for extensive molecular calculations.
Hand and forearm infections caused by Aeromonas hydrophila

This is a report of two cases of hand and forearm infections caused by Aeromonas hydrophila. This organism is resistant to penicillin and most cephalosporins and is found in most freshwater environments. It is recommended that broad-spectrum coverage such as a combination of cephalosporin and aminoglycoside antibiotic be used.
Supermarket Merger Enforcement

Abstract Retail mergers are one of the most frequent areas of antitrust enforcement. In particular, the Federal Trade Commission has taken a substantial number of supermarket merger enforcement actions. The author describes some of the important analytical concepts addressed in supermarket merger enforcement. The author identifies the Federal Trade Commission’s evolving approach to important issues such as remedy and explains the basis for the Commission’s more comprehensive approach to competitive problems in this area.
Foreign body aspiration: an important etiology of respiratory symptoms in children.

Allergists and pulmonologists are commonly confronted with patients who have symptoms of chronic cough, wheeze, and dyspnea. Most of these children are diagnosed with asthma and successfully treated with asthma medications. A subset of these patients, however, does not respond as expected to standard asthma therapy and presents a diagnostic challenge. The possibility of foreign body aspiration should be considered in any child who presents with these symptoms.
A plate with a crack, stiffened by a partially debonded stringer

The effect of a partially debonded infinite stringer on the stress intensity factor at the crack tip is investigated. It is assumed that the stringer is bonded to an isotropic plate through an adhesive, along a line perpendicular to the crack. Due to the high stress concentration around the crack tip and on the adhesive, partial debonding is assumed to develop between the stringer and the plate. The integral equation, obtained from the continuity of displacements along the line where the stringer and the plate are bonded, is solved numerically to give the shear stress distribution between the plate and the stringer and the stress intensity factors at both crack tips.
Protein phosphorylation in rat hippocampal synaptic plasma membranes in response to neurohypophyseal peptides

Abstract The effect of arginine vasopressin (AVP) on protein phosphorylation in rat hippocampal synaptic plasma membranes (SPM) was examined. With a crude SPM preparation, AVP (10 −8 –10 −5 M) stimulated phosphorylation of a number of proteins which included a brain-specific protein of 48 kDa called B50 or protein F1, which is thought to be related to synaptic plasticity. Equimolar levels of oxytocin also stimulated B50/F1 phosphorylation. AVP and oxytocin at the higher concentrations (10 −4–10 −3 M) reduced SPM protein phosphorylation. When SPM was treated with both AVP and oxytocin, the effects were not additive; on the other hand, the effects of the phorbol ester (TPA) and AVP were additive. With SPM, partially purified by sucrose density centrifugation, only the inhibitory effect of AVP on B50/F1 phosphorylation was seen. These results suggest that AVP and oxytocin stimulation of B50/F1 phosphorylation requires cellular factors which are removed from SPM during membrane purification. In contrast, the inhibitory mechanism triggered by AVP and oxytocin appears to be associated with, or an integral part of, the synaptic membrane itself. Because the effects on membrane protein phosphorylation with maximal amounts of AVP and oxytocin were not additive, they must bind to the same sites on the membrane. This conclusion is supported by the additivity of the effects of AVP and phorbol ester, since the phorbol ester can act directly on the kinase and does not require a membrane recognition site.
Solvation dynamics in ionic fluids: an extended Debye-Hückel dielectric continuum model.

Motivated by our recent proposition on the possibility of using dielectric continuum models to interpret experimental measurements of solvation dynamics in room temperature ionic liquids [J. Phys. Chem. A 110, 8623 (2006)], some detailed simulation studies are performed to test the validity of our proposition. From these simulation studies, it seems to be justified that an extended Debye-Huckel continuum model can be used to understand the solvation dynamics of ionic fluids. The theoretical underpinning of such an extended Debye-Huckel model is presented from the general dispersion relation in electrodynamics. The connection with the static extension from the dressed ion theory of electrolyte solutions is also discussed. Such a connection between the Debye-Huckel theory and the dispersion relation may be exploited to enhance our understanding of the electric double layer problem not only for the static case but also for dynamic situations.
Efficiency of Sperm Use in Queens of the Fire Ant, Solenopsis invicta (Hymenoptera: Formicidae)

Like most social Hymenoptera, queens of the fire ant, Solenopsis invicta Buren, mate only at the beginning of their reproductive lives. They receive an initial supply of about 7 million sperm which they gradually parcel out over a period of almost 7 yr until the supply is exhausted and they can no longer produce female offspring. Using the monogynous form of the fire ant, efficiency of sperm use was determined directly by allowing four newly mated queens to rear approximately 0.5 million workers. The mean sperm count of these queens declined by 1.7 million from the starting value, yielding an efficiency of 3.2 sperm per adult female offspring. Sperm-use efficiency was also determined indirectly for field queens based on calculations that show these queens expend 7.0 million sperm to produce 2.6 million workers for an efficiency of about 2.6 sperm per adult female. Lifetime worker production was calculated from annual estimates of colony growth and worker turnover. These estimates of fire ant sperm-use efficiency are about 10 times higher than those reported for honey bee queens and astronomically higher than those of most nonsocial animals. Apparently, efficient use of sperm is an important reproductive capability for S. invicta and other social insects with high reproductive outputs.
The Effect of Anisotropy and Vertical Fracture Penetration on Production Decline Curves for Low Permeability Gas Wells

This study investigates the effect of vertical fracture penetration and horizontal anisotropy in the development of production decline curves for a low permeability gas reservoir. It is shown that the productivity for a given vertical fracture decreases as the fracture position departs from the center of the formation interval. Horizontal anisotropy significantly impacts production decline curves. Up to approximately 70 percent of cumulative recovery is affected significantly regardless of the fracture penetration ratio. 11 refs.
Peer-to-peer locking of magnetrons: Analysis and experiment

The viability of coherent power combination of multiple high-efficiency, moderate power magnetrons requires a thorough understanding of frequency and phase control. Injection locking of conventional magnetrons, and other types of oscillators, employing a master-to-slave configuration has been studied theoretically and experimentally [1,2]. We focus on peer-to-peer locking between two conventional magnetrons [3]. Previous work on similar topics assumed equal power and free-running frequency among magnetrons [4,5]. Such assumptions are removed in this analysis. The necessary condition under which two magnetrons may be locked to a common frequency is derived, with their coupling described by a general 2×2 matrix. Dependent on the degree of coupling, the frequency of oscillation when locking occurs was found to not necessarily lie between the two magnetrons' free running frequencies. Likewise, when the locking condition was violated, the beat of the spectrum was not necessarily found to be equal to the difference between the free running frequencies. The beat frequency could be larger, as was observed in our experiments. The stability (accessibility) and temporal evolution of the two possible states in which the locking conditions of the two magnetrons are satisfied are being examined. The formulation was then extended to the locking of N magnetrons. Experimental results on the peer-to-peer phase-locking of two 1-kW magnetrons will be reported.
Bridging the Gap Between Inpatient and Outpatient Providers Using Organizational Elements of Assertive Community Treatment

Even among comprehensive local public mental health systems, there remain large gaps in continuity of care following discharge from inpatient settings. The authors describe a modification of the assertive community treatment (ACT) program model that links inpatients to ongoing community-based care, and provide preliminary evidence of its effectiveness as a component in a rationally organized comprehensive system of care. Given the recent trend toward managed Medicaid arrangements, there will be increased pressure to reduce clients' length of stay in ACT programs. State mental health authorities are cautioned to resist allowing managed care contractors to radically change the conditions under which ACT programs operate until there is greater evidence of the effectiveness of alternative approaches.
Effects of ascorbic acid on levels of fibronectin, laminin and collagen type 1 in bovine trabecular meshwork in organ culture

PURPOSE. Fibronectin, laminin and collagen type I are important extracellular matrix products of trabecular meshwork cells. This study was performed to examine the effects of ascorbic acid, a significant component in the aqueous humor, on the levels of these proteins in trabecular meshwork cells maintained in organ culture. METHODS. The anterior segment of freshly enucleated bovine eyes was perfused in a modified organ culture system. Three cultures were set up simultaneously. One received serum-free medium containing 100 µg/ml of ascorbic acid, one received 250 µg/ml of ascorbic acid and one served as a control. After 72 h, the tissues were processed for paraffin sections and immunostaining was conducted using an avidin-biotin-peroxidase complex method. Western blot and dot blot assays were performed on tissue extracts. RESULTS. Compared with the controls, the staining for fibronectin and laminin was markedly enhanced in trabecular meshwork tissues treated with both concentrations of ascorbic acid. Incre...
π-domains, overrings, and divisorial ideals

In this paper we study several generalizations of the concept of unique factorization domain. An integral domain is called a π-domain if every principal ideal is a product of prime ideals. Theorem 1 shows that the class of π-domains forms a rather natural subclass of the class of Krull domains. In Section 3 we consider overrings of π-domains. In Section 4 generalized GCD-domains are introduced: these form an interesting class of domains containing all Prufer domains and all π-domains.
Associations between preoperative functional status and functional outcomes of total joint replacement in the Dominican Republic

Objective. In developed countries, the functional status scores of patients with poor preoperative scores undergoing total joint replacement (TJR) improve more following TJR than those for patients with better preoperative scores. However, those with better preoperative scores achieve the best postoperative functional outcomes. We determined whether similar associations exist in a developing country. Methods. Dominican patients undergoing total hip or knee replacement completed WOMAC and SF-36 surveys preoperatively and at 12-month follow-up. Patients were stratified into low-, medium- and high-scoring preoperative groups based on their preoperative WOMAC function scores. We examined the associations between the baseline functional status of these groups and two outcomes—improvement in functional status over 12 months and functional status at 12 months—using analysis of variance with multivariable linear regression. Results. Patients who scored the lowest preoperatively made the greatest gains in function and pain relief following their TJRs. However, there were no significant differences in pain or function at 12-month follow-up between patients who scored low and those who scored high on preoperative WOMAC and SF-36 surveys. Conclusion. Patients with poor preoperative functional status had greater improvement but similar 12-month functional outcomes compared with patients who had a higher level of function before surgery. These results suggest that a policy of focusing scarce resources on patients with worse functional status in developing countries may optimize improvement following TJR without threatening functional outcome. Additional research is needed to confirm these findings in other developing countries and to understand why these associations vary between patients in the Dominican Republic and patients from developed countries.
Bias in drug abuse survey research

An analysis of the drug abuse literature indicated that significant biases may affect the existing data. First, the lack of standardization in survey research leads to problems of reliability, validity, and objectivity in drug abuse measurement. Second, the "demand characteristics" of the survey situation may cause the subject to bias his responses in a particular direction, depending on his interaction with and his interpretations of the survey conditions. Third, both overt and covert biases of the researcher may significantly affect the outcome of the survey. Fourth, limitations of the survey method itself (e.g., the source of the survey data, difficulties in obtaining random samples, conclusions overemphasizing student drug use, limitations of the sample survey as a measurement device) seriously restrict our understanding of drug abuse phenomena.
Calvin's Conception of the “Communio Sanctorum”

The year 1936 marks the four hundredth anniversary of the Institutes of the Christian Religion.' In that work is contained the mature expression of Calvin's religious thought. Attention may well be centered, at this time, upon one of the most procreative conceptions contained in the Institutes-a conception still rich in suggestions for our community of Christian life. The conception is that of the "societas fideliurt" or the "communio sanctorum." In the following study the "communio sanctorum" is considered in relation to its concept and to predestination, cult, discipline, and social service.
Copper(II) oxide nanowire array hydrogen sensor via facile large area contact integration

This paper presents a novel method to achieve large area contact integration for copper(II) oxide (CuO) nanowire array-based hydrogen gas sensors, which provides a simple solution to the ongoing challenge of harvesting nanostructured materials for gas sensing applications. The method presented herein offers six distinct advantages over previous nanostructured gas sensing technologies: (1) convenient electrical access to as-grown, freestanding nanowire arrays, thereby obviating postgrowth thin-film metallization, (2) lithography-free fabrication, (3) usage of large area nanowire arrays to circumvent low yield of single nanowire sensors, (4) reusability of contacts for batch characterization, (5) compatibility with all free-standing arrays grown on electrically conductive substrates, and (6) rapid response and recovery times. The CuO nanowire array-based gas sensors exhibited 5× to 25× increased resistance during operation, and a 20× improvement in recovery time compared to prior works.
Adaptive Robust Precision Control of Piezoelectric Positioning Stages

Positioning stages using piezoelectric stack actua- tor (PEA) have very high theoretical bandwidth and resolution. However, as the total length of travel increases, nonlinear dynamics due to inherent hysteresis starts to dominate. In this paper, we separate the fast and slow dynamics of the total displacement and propose a simple first-order model. By approximating the hysteresis mapping with simple functions, it is linearly parameterized for subsequent adaptive robust controller design. Experimental results from tracking control of sinusoidal and point-to-point trajectories show tracking error on the magnitude of the sensor noise level and demonstrate the effectiveness of the approach. Index Terms— Piezoelectric Actuators, Motion Control, Adaptive Control, Robust Control, Precision Manufacturing. I. INTRODUCTION hysteresis with simple functions, we obtain a simple first order model linearly parameterized by 4 parameters, which can be adapted online for model compensation. The adaptive robust control (ARC) scheme (4) is applied to the model, which adapts the unknown parameters using a discontinuous projection based method, and the uncompensated unknown nonlinearities are attenuated by certain robust control laws. As a result, the time consuming identification of the exact hysteresis dynamics is avoided without sacrificing tracking performance.
Misconceptions about Psychology among Students Who Perform Highly

Two measures assessing “behavioral myths” and learning expectations were given to 54 students in three sections of introductory psychology. Comparison of pre- and posttest myth scores over the seme...
Can quantum coherent solar cells break detailed balance

Carefully engineered coherent quantum states have been proposed as a design attribute that is hypothesized to enable solar photovoltaic cells to break the detailed balance (or radiative) limit of power conversion efficiency by possibly causing radiative recombination to be suppressed. However, in full compliance with the principles of statistical mechanics and the laws of thermodynamics, specially prepared coherent quantum states do not allow a solar photovoltaic cell—a quantum threshold energy conversion device—to exceed the detailed balance limit of power conversion efficiency. At the condition given by steady-state open circuit operation with zero nonradiative recombination, the photon absorption rate (or carrier photogeneration rate) must balance the photon emission rate (or carrier radiative recombination rate) thus ensuring that detailed balance prevails. Quantum state transitions, entropy-generating hot carrier relaxation, and photon absorption and emission rate balancing are employed holistically and self-consistently along with calculations of current density, voltage, and power conversion efficiency to explain why detailed balance may not be violated in solar photovoltaic cells.