cssi/SciSciGPT-SciSciNet huggingface dataset:
The extraction equilibria of lutetium, ytterbium and thulium between di-(2-ethylhexyl) phosphoric acid in Amsco and aqueous hydrochloric acid solutions

Abstract Single-component equilibrium data for the extraction of lutetium and ytterbium from aqueous hydrochloric acid solutions by 1M di-(2-ethylhexyl) phosphoric acid in Amsco Odorless Mineral Spirits were obtained over a wide range of equilibrium aqueous rare earth chloride concentrations and at an equilibrium aqueous acidity of 5M HCl. These data were compared with data taken earlier[1] for thulium. The shapes of the organic-phase loading isotherms (or equilibrium curves) for Lu, Yb, and Tm are similar and have been interpreted on the basis of several probable extraction reactions. Under the conditions studied, the extractability of the rare earths increased in the order Tm
Quantitative structure-activity relationships for the mutagenicity of propylene oxides with Salmonella

Abstract A quantitative structure-activity relationship approach was used to investigate the mutagenicity of a series of seventeen-monosubstituted propylene oxides in Salmonella typhimurium strains TA100 and TA1535. Mutagenicity in strain TA100, using a liquid suspension assay, was found to correlate with chemical reactivity, as measured by the rates of reaction with two model bionucleophiles, nicotinamide and 4-(4-nitrobenzyl)pyridine. However, since the reactivity of three of the epoxides did not correlate to their Taft σ ∗ values, as a measure of the electronic effects of substituent groups, neither was their mutagenicity predicted by this substituent constant. The relative mutagenicity for the propylene oxides was different in the liquid suspension assay than that determined by the standard plate incorporation assay and also differed between the two bacterial strains. The assay differences were attributed to epoxide stability. The differences between strains was observed to be due to the response of the error-prone repair system, found only in TA100, to the stronger alkylating agents.
Physiological activity of a bioluminescent Pseudomonas fluorescens (strain 2–79) in the rhizosphere of mycorrhizal and non-mycorrhizal pepper (Capsicum annuum L.)

Abstract Physiological status and root-colonization of Pseudomonas fluorescens 2–79RL were examined in presence or absence of mycorrhizae on the roots of pepper over 6 weeks. Due to incorporation of a ribosomal promoter-driven lux marker into the chromosome of this bacterium, the end of the lag phase and onset of exponential growth is marked by an exponential increase in bioluminescence. In vitro , the duration of the lag phase of bioluminescence after transfer of cells to rich medium increased when the cells had been grown under low nutrient conditions or subjected to prolonged starvation. Lag phase duration thus provided a marker for assessment of changes in the physiological status of P. fluorescens 2–79RL. Pepper plants, non-mycorrhizal or mycorrhizal with Glomus intraradices (GI) or Glomus deserticulum (GD), were grown for 42 days in microcosms containing soil inoculated with P. fluorescens 2–79RL. A blotting technique using filter paper strips was developed to sample cells from the rhizosphere, after which the cells were resuspended for enumeration and determination of lag phase duration. During the first 3 weeks, the population density of P. fluorescens 2–79RL (cfu mm −2 ) decreased by one order of magnitude on the roots and by two orders of magnitude in the bulk soil. The lag phase of bioluminescence remained stable during the first 20 days in the rhizosphere and the bulk soil, but then increased up to day 27 and remained at the higher level until day 38. The length of the lag phase was greater in the bulk soil than in the rhizosphere. Compared with the non-mycorrhizal plants, mycorrhizal infection by GD significantly decreased shoot dry weight and the population of P. fluorescens 2–79RL in the rhizosphere at the root tip and on the older root parts. GD also significantly increased the length of the lag phase of bioluminescence on the older root parts. The effect of GI was less pronounced. The results show this bacterium may be subject to moderate to severe starvation in the rhizosphere and that there are differential effects of specific mycorrhizal fungi on both the population and activity of this root-colonizing pseudomonad.
Derivative trading by utility firms

This paper examines the use of derivatives by a utility company. The hedging problem for utilities is atypical; the goal is not strictly to minimize average costs. Rather, the objectives are to minimize the upside risk associated with extreme bills, volatility of bills, and average expected bills for consumers. We characterize the optimal positions on futures contracts and options on futures that a utility company should assume. The results indicate that the use of derivatives (both futures and options on futures) is an efficient means of optimizing the objective functions without exposing consumers to speculative risk.
A 74-Year-Old Woman With Diabetes

Ms M, a 74-year-old woman with type 2 diabetes of 6 years' duration, has a glycated hemoglobin (HbA1C) value of 7.4% despite taking 3 oral antidiabetic medications, as well as coexistent hypertension and abdominal obesity. She has no known microvascular or macrovascular complications of diabetes and is otherwise healthy. She is reluctant to commence insulin treatment as she dislikes the idea of injections and wonders if there are any alternate options if she is to get her HbA1C value below 7%. The natural history of type 2 diabetes, reasons why many patients begin requiring insulin over time, rationale for tight glycemic control, and therapeutic options for Ms M are discussed.
Simple conditions for the appearance of sustained oscillations in continuous crystallizers

Abstract Continuous crystallizers are known to exhibit sustained oscillations in solute concentration and size distribution. The usual stability analysis for mixed suspension, mixed product removal crystallizers is obscured by the use of dimensionless groups which not only depend upon the physical properties and control parameters in the problem but also depend upon the steady-state values of the state variables in the model. We introduce three new dimensionless groups for this problem which only depend upon physical properties and control parameters. These produce a stability plot which is simpler than previous attempts and lends itself to easy physical interpretation.
Sequence‐specific binding by Aspergillus nidulans AflR, a C6 zinc cluster protein regulating mycotoxin biosynthesis

The Aspergillus nidulans aflR gene is found within a 60 kb gene cluster that includes approximately 24 other genes that putatively function in the production of the aflatoxin-related mycotoxin sterigmatocystin. Previous work showed that AflR is a C6 zinc binuclear cluster protein that is conserved across Aspergillus spp. and functions as a pathway-specific transcription factor in activating expression of other cluster genes. In this report, we demonstrate that A. nidulans AflR (AnAflR) is a 45kDa protein that binds to the palindromic sequence 5'-TCG(N5)CGA-3' found in the promoter regions of several aflatoxin and sterigmatocystin cluster genes (stc genes). The in vivo relevance of this AnAflR binding site was assessed by examining the contribution of the three TCG(N5)CGA elements in the 1.1 kb promoter region of stcU using gene fusions with the bacterial uidA gene encoding beta-glucuronidase (GUS). By mutating one, two or all three of the AnAflR-binding elements and examining GUS activity in wild-type aflR or delta aflR A. nidulans strains, we found that stc gene activation required both AnAflR and at least one TCG(N5)CGA AflR binding site.
Learning More from the Wisdom of Practice.

Faculty's experience-based knowledge about teaching is rarely informed by existing educational frameworks and models. Can the wisdom of practice be improved and thereby contribute more to the scholarship of teaching?
The hazard of scattered radiation in a trauma intensive care unit.

Objective: Patients admitted to the trauma intensive care unit (TICU) often require bedside imaging procedures such as radiographs, fluoroscopic placement of enteral feeding tubes, and insertion of vena cava filters. The potential for scattered radiation exposure is a concern to healthcare workers. Our study's purpose was to measure the level of scattered ionizing radiation present in a TICU. Design and Setting: This prospective study was conducted over 3 months in an open-design, ten-bed TICU of a Level I trauma center. Interventions and Measurements: Fifteen dosimeters were placed in selected areas of the TICU to measure the amount of scattered radiation present. Standard radiation protection precautions were used throughout the study period. At the end of each month, data from the dosimeters were sent to the manufacturer for analysis. Main Results: One thousand seventy-four radiologic studies were performed at the bedside during the study period (803 portable chest radiographs, 103 abdominal radiographs, 303 extremity radiographs, 223 spine radiographs, and 15 fluoroscopic procedures). Dosimetry analysis showed <5 mrem (1/1000 roentgen equivalent in man) scattered radiation per month (<60 mrem/ year) in each of the monitored areas. All monitored areas measured <2 mrem per week of scattered radiation when adjusted for occupancy. Conclusions: The level of scattered radiation in our TICU is less than the recommended allowable exposure of <100 mrem/year, indicating that radiation exposure is not a significant occupational hazard in our TICU, even in the setting of frequent use of bedside imaging studies.
19-Nordeoxycorticosterone excretion in male and female inbred salt-sensitive (S/JR) and salt-resistant (R/JR) Dahl rats.

Rats were selectively bred for susceptibility (S) and resistance (R) to the hypertensinogenic effects of excess salt intake by Dahl and further inbred to virtual homozygosity by Rapp (S/JR and R/JR). The S strain has been shown to have a mutation of the cytochrome P-450-dependent 11β,18-hydroxylase resulting in the enhanced production of 18-hydroxydeoxycorticosterone (18-OH-DOC) compared to that of the R strain.-It is known that this enzyme is also responsible for the hydroxylation of deoxycorticosterone at the 19 position to produce 19- hydroxydeoxycorticosterone. Recently, the excretion of 19-nordeoxycorticosterone (19-nor-DOC), a potent mineralocorticoid, has been shown to be markedly increased in S/JR females compared to that in R/JR females consuming a high sodium diet. While the S/JR rat is spontaneously hypertensive, the course of the disease is greatly accelerated and exacerbated by a high sodium diet. If, indeed, 19-nor-DOC is responsible for the spontaneous hypertension in the S/JR rat, then its...
A systematic study of parameters of afferent vagal stimulation in the anesthetized dog: blood pressure reflexes.

1. This study has confirmed the long recognized observations that stimulation of the central end of a mixed nerve will result in a reflex change in the systemic blood pressure. 2. The direction of the change in blood pressure is influenced by the frequency, voltage, and pulse duration of stimulus applied to the nerve. 3. Careful preparation of the nerve will ensure the prolonged ability of the nerve to respond to the stimulus. 4. A systematic study of the frequency, voltage, and pulse duration of electrical stimulation has been worked out and “pressor” ranges and “depressor” ranges of combinations of these parameters have been designated so that the consistent reproducible blood pressure responses to centripetal vagal stimulation can be predicted by the selection of the exact combination of parameters.
Tuning Dynamic Range and Sensitivity of White-Light, Multimode, Fiber-Optic Surface Plasmon Resonance Sensors

This paper presents the advantages of modifying the geometry of the sensing tip of a white-light, multimode optical fiber SPR sensor to optimize the dynamic range and sensitivity. By selectively beveling the distal end of the fiber probe, the wavelength of resonance can be red-shifted by more than 100 nm and blue-shifted by more than 30 nm. This increases the flexibility of a white-light SPR sensor by increasing the dynamic range of accessible RIs and by shifting the resonance to the most sensitive regions of the detector. Sensitivity, measured in wavelength shift per RI change, can be increased by a factor of 4. Also, multiple-wavelength regions of SPR activity can simultaneously be observed on the same probe, thus increasing the information content of a SPR spectrum.
Scanning tunnelling microscopy of graphite‐adsorbed molecular species

SUMMARY A new variable-temperature STM has been used to perform studies of the adsorption and ordering of simple polar molecules such as acetone and dimethylsulphoxide (DMSO) on graphite. The primary objective of this work is to obtain fundamental information which can serve as a basis for studies of complex systems. Following exposure of graphite to acetone vapour, STM images show cloudy patches of acetone drifting across the surface, with individual molecules being indistinguishable. Following prolonged exposure, however, an ordered monolayer forms, having triangular symmetry and 2×2 commensurate periodicity relative to the substrate. Similar results are obtained for DMSO on graphite; however, the monolayer is more closely packed and probably incommensurate with the substrate. In a related effort, nitric acid is shown to be an effective chemical etch for creating steps in basal plane graphite. It is hoped that this, and related techniques, will enable the use of STM to study important chemical systems, such as treated fuel-cell electrodes, which utilize non-basal plane graphite.
Regulation of heat shock protein 70 gene expression by c-myc.

The myc gene seems to have a causal role in tumour formation in man, mouse and avian systems1–3. The myc gene product has been localized to the nucleus4,5, suggesting that it may be involved in the regulation of gene expression. The level of expression of the mammalian heat shock protein 70 (HSP70) gene is elevated in several tumour cell lines6, implying that a cellular function expressed in these tumour lines can stimulate HSP70 production. We report here that the gene product of a rearranged mouse c-myc gene is capable of stimulating expression of chimaeric genes containing a Drosophila hsp70 promoter region and 5′-flanking sequences. This stimulation is dependent on sequences located more than 200 bases 5′ of the normal start of hsp70 transcription.
Habitat fragmentation as a result of biotic and abiotic factors controls pathogen transmission throughout a host population

1. The hypothesis that habitat fragmentation (biotic or abiotic) alters the transmission of disease within a population is explored using field data from a well-studied amphibian-pathogen system. 2. We used the Ambystoma tigrinum-A. tigrinum virus (ATV) model system to show how habitat fragmentation as a result of emergent vegetation and habitat management affects disease transmission dynamics in ponds across a landscape. 3. We quantified variation in ATV infection over time and across the landscape. ATV infection was significantly higher in ponds modified for livestock use (P = 0.032). Disease incidence decreased with increased amounts of emergent vegetation (P < 0.001). These factors appear to control disease transmission by altering the host contact rate and with it disease transmission. 4. A field experiment to test the effect of emergent vegetation on the distribution of larvae in ponds demonstrated a behavioural change in larvae found in sparsely vegetated ponds. Microhabitat choices resulted in larvae being concentrated at the pond edge resulting in a 'halo effect' in sparsely vegetated ponds, whereas larvae in heavily vegetated ponds were distributed more evenly throughout. Microhabitat choice affects the effective density that larvae experience. This 'halo effect' increases contact rates in the shallows of sparsely vegetated ponds and increases the transmission of a directly transmitted pathogen. 5. Despite recurrent epidemics of a lethal Ranavirus in tiger salamanders on the Kaibab Plateau, Arizona, USA, these populations persist. We discuss the implications of our results in the context of density-dependent transmission and homogeneous mixing, two increases key assumptions of epidemiological theory.
Digestion of starch granules by α-amylases from the rice weevil, Sitophilus oryzae: effect of starch type, fat extraction, granule size, mechanical damage, and detergent treatment

Abstract In vitro digestion of raw starch granules by α-amylases from the rice weevil, Sitophilus oryzae (L.), was studied. Digestion of starch granules isolated from ball-milled cereals, especially corn and wheat, was extremely slow. Relative to intact starch granules of rice, corn, and wheat, gelatinized samples were 550-, 2000-, and 3300-fold, respectively, more susceptible to enzyme action. Among commercial starch samples tested, granular potato starch was most resistant to α-amylases from S. oryzae. Relative to granular potato starch, activity against other tested starches ranged from 2.1-fold greater for tapioca starch to 15.9-fold greater for an unmodified corn starch. Size distribution of granules of an unmodified wheat starch was determined by sequential passage through a series of nylon screens. Larger granules (15–20 μ) were 2.4-fold more susceptible than smaller granules (5–10 μ) to α-amylase. Defatted granules were slightly more susceptible than nondefatted granules to enzymatic degradation. α-Amylase activity against intact starch granules purified from soft wheat kernels (“Florida 302”) was increased 119-fold when the granules were extensively homogenized in a ground glass homogenizer. Activity against granules damaged by grinding in a mortar and pestle or a mechanical grinder was also increased. Presence of a detergent (Triton X-100) in the grinding buffer gave only a slight increase (14%) in susceptibility. Studies comparing the activity of α-amylase and crude gut homogenates of S. oryzae indicated that α-amylase is the primary enzyme that attacks granular starch in the gut. In addition, we could find no evidence that α-amylases from S. oryzae bind for a relatively long duration to intact or mechanically damaged granules from Florida 302. Based on these results, in our view, the precise mechanisms and efficiencies of the enzymatic conversion of granular starch to utilizable nutrients in vivo cannot be adequately assessed from in vitro assays with gelatinized starch and thus remain to be determined. A hypothesis for the in vivo digestion of granular starch by phytophagous insects is presented.
Analyses of CD20 monoclonal antibody-mediated tumor cell killing mechanisms: rational design of dosing strategies.

Since approval of rituximab for treatment of B cell non-Hodgkin lymphoma, development of monoclonal antibodies (mAbs) for cancer treatment and elucidation of their cytotoxic mechanisms have been subject to intense investigations. Compelling evidence indicates that rituximab and another CD20 mAb, ofatumumab, must use the body’s cellular and humoral immune effector functions to kill malignant cells. Other U.S. Food and Drug Administration–approved mAbs, including obinutuzumab, cetuximab, and trastuzumab, require, in part, these effector mechanisms to eliminate tumor cells. Although gram quantities of mAbs can be administered to patients, our investigations of CD20 mAb-based therapies for chronic lymphocytic leukemia (CLL), including correlative measurements in clinical trials and studies with primary cells and cell lines, indicate that effector mechanisms necessary for mAb activity can be saturated or exhausted if tumor burdens are high, thus substantially compromising the efficacy of high-dose mAb therapy. Under these conditions, another reaction (trogocytosis) predominates in which bound CD20 mAb and CD20 are removed from targeted cells by effector cells that express Fcγ receptors, thereby allowing malignant cells to escape unharmed and continue to promote disease pathology. To address this problem, we propose that a low-dose strategy, based on administering 30–50 mg of CD20 mAb three times per week, may be far more effective for CLL than standard dosing because it will minimize effector function saturation and reduce trogocytosis. This approach may have general applicability to other mAbs that use immune effector functions, and could be formulated into a subcutaneous treatment strategy that would be more accessible and possibly more efficacious for patients.
THE ETIOLOGY OF POST-RADICAL PROSTATECTOMY INCONTINENCE AND CORRELATION OF SYMPTOMS WITH URODYNAMIC FINDINGS

AbstractPurpose: We evaluated men with post-radical prostatectomy incontinence to determine the incidence of intrinsic sphincter deficiency and bladder dysfunction, and the contribution of each to incontinence. In addition, we determined if subjective symptoms of stress urinary incontinence and urge incontinence correlated with urodynamic findings of intrinsic sphincter deficiency and bladder dysfunction, respectively.Materials and Methods: A total of 60 consecutive patients (mean age 64.8 years) were prospectively evaluated with multichannel video urodynamics. All patients were evaluated at least 6 months postoperatively and had achieved a stable level of continence. Patients characterized incontinence as stress or urge related, and stress urinary incontinence was graded from 0 to 3. Intrinsic sphincter deficiency was defined as incontinence associated with increased intra-abdominal pressure and was further assessed by Valsalva's leak point pressure. Bladder dysfunction included urodynamic findings of de...
Moderate- to low-risk variant alleles of cutaneous malignancies and nevi: lessons from genome-wide association studies

Cutaneous malignancies, especially malignant melanoma, exhibit great genetic heterogeneity. As a result, some individuals and families have particularly increased risk due to genetic predisposition to the disease. The susceptibility alleles range from rarely occurring, heritable, high-risk variants to ubiquitously occurring low-risk variants. Although until now the focus has been mostly towards the familial high-risk genes, the development of genome-wide association studies has uncovered a number of moderate- to low-risk predisposition alleles. The ability to specifically identify genetic variation associated with visible pigmentation traits and disease risk has provided a much richer view of the genetics of cutaneous malignancies. In this review, we provide an update on the recently identified risk loci. Existing clinical data, combined with vast genome information, will provide a better understanding of the biology of disease, and increased accuracy in risk prediction.
Finding defects with fault models

A process is presented to validate fault models used in fault diagnosis. Known defects are inserted, using a focused ion beam (FIB), into production ICs and their behavior is compared to that predicted in fault simulation. The fault model is refined until it matches the observed defect behavior. The process is then repeated with known defects in unknown ("blind") locations, and necessary modifications to the model are again made. Finally, the model is used to diagnose chips with unknown defects. Experimental results on several chips demonstrate the value of the approach, which can be extended to test pattern generation and test quality estimation as well as fault diagnosis.
Comparison of bioelectrical impedance and BMI in predicting obesity-related medical conditions.

Objective: To determine the relative validity of specific bioelectrical impedance analysis (BIA) prediction equations and BMI as predictors of physiologically relevant general adiposity. Research Methods and Procedures: Subjects were >12, 000 men and women from the Third National Health and Nutrition Examination Survey population. We examined the correlations between BMI and percentage body fat based on 51 different predictive equations, blood pressure, and blood levels of glucose, high-density lipoprotein cholesterol, and triglycerides, which are known to reflect adiposity, while controlling for other determinants of these physiological measures. Results: BMI consistently had one of the highest correlations across biological markers, and no BIA-based measure was superior. Percent body fat estimated from BIA was minimally predictive of the physiological markers independent of BMI. Discussion: These results suggest that BIA is not superior to BMI as a predictor of overall adiposity in a general population.
Intercollegiate debate: Why do students bother?

This study addresses the question “Why do debaters debate?” Although assumptions have been made by previous researchers, the question has not been directly investigated. The importance of an answer to this question is illustrated at four levels: the speech communication discipline, the college administrator, the debate coach, and the individual debater. Content analysis is used to ascertain the range of motivational interpretations among college debaters at three southeastern tournaments. Findings witness the emergence of a core of four broad motivational interpretations and begin to challenge the assumed importance of competition as a primary motivation.
PREJUNCTIONAL AND POSTJUNCTIONAL EFFECTS OF TUBOCURATINE AND PANCURONIUM IN MAN

The effects of small doses of tubocurarine and pancuronium on peak tetanic tension and tetanie maintenance were compared. Forty patients undergoing elective orthopaedic procedured under general anaesthesisa were studied. Changes in neuromuscular transmission were measured by recording the isometric contraction of the adductor pollicis muscle evoked by supramaximal stimulation of the ulnar nerve at the wrist. Small doses of pancuronium affected predominantly the peak tetanic tension, while small doses of tubocurarine affected mainly tetanic maintenance. Thus, different degrees of depression of peak tetanic tension and tetanic maintenance were observed with tubocurarine and pancuronium. This clinical study supports Bowman’s hypothesis, based upon laboratory findings in the cat, that prejunctional and postjunctional effects of neuromuscular blocking agents depend on their affinity for cholinoceptors at different sites.
A comparison of 2 protocols to detect intimate partner violence.

PURPOSE: Intimate partner violence (IPV) frequently results in maxillofacial injuries. The purpose of this study is to compare 2 protocols to identify women who self-report IPV-related injuries. MATERIALS AND METHODS: Using a cross-sectional study design, we enrolled a sample of injured women who presented to the emergency department (ED) for evaluation and treatment. The predictor variable was the protocol used to identify injury etiology, that is, an innovative diagnostic protocol (DP) or the ED's standard operating procedure (SOP). The outcome variable was self-reported injury etiology categorized as IPV or other. Descriptive and bivariate statistics were computed. Sensitivity, specificity, positive predictive value, negative predictive value, and odds ratios were computed (with P Language: en
Converting enzyme inhibition with captopril abolishes sympathoexcitation to euglycemic hyperinsulinemia in rats.

Abstract Converting enzyme inhibition and angiotensin II receptor antagonism attenuate elevations in heart rate and plasma norepinephrine in response to insulin, suggesting that integrity of the renin-angiotensin system is necessary for insulin-induced sympathoexcitation. To test this, we infused vehicle (saline) in control experiments, or insulin (40 mU/min) during euglycemic clamp in captopril-pretreated (intravenously 2.5 mg/kg, then 1 mg/kg/h) and in nonpretreated urethane-anesthetized Wistar rats while measuring mean arterial pressure, heart rate, and lumbar sympathetic nerve activity. Although euglycemic hyperinsulinemia produced similar blood pressure (BP) increases in insulin-infused rats (change in mean arterial pressure: +9 ± 3 mm Hg) compared with vehicle-controls (+6 ± 2 mm Hg), insulin decreased blood pressure (BP) in captopril-pretreated insulin-infused rats (−8 ± 3 mm Hg). Control rats developed mild heart rate increases (change in heart rate: +28 ± 15 beats/min), contrasting with a marked tachycardia in insulin-infused rats (+82 ± 13 beats/min) and a bradycardia in captopril-treated insulin-infused rats (−16 ± 18 beats/min). As with heart rate, insulin-infused rats experienced large increases in lumbar sympathetic nerve activity (+127 ± 29%), whereas small and equivalent elevations were observed in vehicle-treated rats (+39 ± 24%) and in captopril-pretreated insulin-infused rats (+61 ± 13%). These observations demonstrate an attenuation of insulin-induced sympathetic activation by renin-angiotensin blockade with captopril in Wistar rats, and suggest that the renin-angiotensin system is critical for insulin to exert its sympathoexcitatory effects.
Remanence loop asymmetry and moving-type Preisach models

The observed asymmetry of the remanence loop of a particulate recording sample can be described by the complete-moving-hysteresis (CMH) model using a symmetrical Preisach distribution. The amount of asymmetry depends on the moving parameter, the squareness, and the reversible magnetization. It is shown that, for certain types of materials, the major hysteresis loop and the major remanence loop provide sufficient information to identify the moving parameter. >
Biotinylation of Histones Represses Transposable Elements in Human and Mouse Cells and Cell Lines and in Drosophila melanogaster

Transposable elements such as long terminal repeats (LTR) constitute approximately 45% of the human genome; transposition events impair genome stability. Fifty-four promoter-active retrotransposons have been identified in humans. Epigenetic mechanisms are important for transcriptional repression of retrotransposons, preventing transposition events, and abnormal regulation of genes. Here, we demonstrate that the covalent binding of the vitamin biotin to lysine-12 in histone H4 (H4K12bio) and lysine-9 in histone H2A (H2AK9bio), mediated by holocarboxylase synthetase (HCS), is an epigenetic mechanism to repress retrotransposon transcription in human and mouse cell lines and in primary cells from a human supplementation study. Abundance of H4K12bio and H2AK9bio at intact retrotransposons and a solitary LTR depended on biotin supply and HCS activity and was inversely linked with the abundance of LTR transcripts. Knockdown of HCS in Drosophila melanogaster enhances retrotransposition in the germline. Importantly, we demonstrated that depletion of H4K12bio and H2AK9bio in biotin-deficient cells correlates with increased production of viral particles and transposition events and ultimately decreases chromosomal stability. Collectively, this study reveals a novel diet-dependent epigenetic mechanism that could affect cancer risk.
Early labeling of children Concerns and alternatives

The issue of labeling young children identified as at risk for academic failure is explored in this article. The author, while strongly supporting early identification and treatment efforts, discusses limitations of using both the generic label “at risk” and the specific categorical label “learning disability” with such children. An orientation to assessment which yields information pertaining to abilities, skills, and knowledge directly related to later academic functioning is recommended. Such assessment is conducted for the purpose of delineating specific strengths and concerns in preacademic behaviors rather than to classify children using diagnostic labels.
Neuronal NT-3 is not required for synaptic transmission or long-term potentiation in area CA1 of the adult rat hippocampus.

Neurotrophic factors, including BDNF and NT-3, have been implicated in the regulation of synaptic transmission and plasticity (for a recent review, see Schuman 1999). For example, BDNF and NT-3 have been found to enhance synaptic transmission at the neuromuscular junction (Lohof et al. 1993) and in area CA1 of the hippocampus (Kang and Schuman 1995). In addition, the induction of long-term potentiation (LTP) leads to increases in both BDNF and NT-3 mRNA levels in area CA1 of the hippocampus (Patterson et al. 1992). Mice with a targeted disruption of the BDNF gene show diminished LTP in the hippocampus (Korte et al. 1995, 1996; Patterson 1996 ). In addition, application of TrkB-IgG fusion proteins can interfere with both early (Figurov et al. 1996; Kang et al. 1997) and late (Kang et al. 1997) LTP in the hippocampus and visual cortex (Akaneya et al. 1997). Unfortunately, similar studies using genetic or pharmacological disruptions of NT-3 function have not been reported owing to mice mortality and lack of reagent availability, respectively. Although most of the homozygous NT-3 knockout mice die within a few days of birth (Ernfors et al. 1994), the heterozygous animals live throughout adulthood, permitting an analysis of synaptic transmission. At the lateral perforant path–granule cell synapse in the dentate gyrus, slices from heterozygous (+/−) knockout animals exhibited normal LTP, but diminished paired-pulse facilitation and post-tetanic potentiation (Kokaia et al. 1998). As of yet, synaptic transmission and plasticity in area CA1 of the hippocampus has not been examined in these mice. NT-3 is expressed in both neurons and glia (Tessarollo et al. 1993). Studies using pharmacological manipulations to examine the contribution of a particular molecule to plasticity are often compromised by an inability to address the source or site of action of the molecule of interest. A similar concern exists for genetic deletion experiments in which a gene is deleted in all cell types. By engineering a transgenic mouse in which the NT-3 gene is selectively deleted in neurons, the present study allowed us to address the contribution of neuronal NT-3 to both synaptic transmission and plasticity in the hippocampus.
The Relation between Parental Constructive Behavior and Adolescent Association with Achievement-Oriented Peers: A Longitudinal Study

There is abundant research about the negative influences of peer groups and other factors contributing to adolescent involvement with deviant peers. This study used three waves of panel data to investigate the relation between parental constructive behavior and adolescent association with achievement-oriented peers. Parental constructive behavior was found to be positively related to adolescents' own achievement orientation a year later, which in turn was positively related to the perceived achievement orientation of friends two years later. However, adolescents' own achievement orientation did not completely mediate the effect of parental constructive behavior on the perceived achievement orientation of friends. Furthermore, after the prior perceived achievement orientation of friends was added into the model, parental constructive behavior still had a direct effect on the perceived achievement orientation of friends over time. Parental constructive behavior contributed to the affiliation with achievement-oriented friends above and beyond the effects of adolescents' own achievement orientation and their prior peer affiliation
Jessen’s type inequality and exponential convexity for positive C0-semigroups

In this paper a Jessen’s type inequality for normalized positive $C_{0}$ -semigroups is obtained. An adjoint of Jessen’s type inequality has also been derived for the corresponding adjoint semigroup, which does not give the analogous results but the behavior is still interesting. Moreover, it is followed by some results regarding positive definiteness and exponential convexity of complex structures involving operators from a semigroup.
Bioavailability of polycyclic aromatic hydrocarbons from a historically contaminated sediment core

To determine changes in bioavailability of selected polycyclic aromatic hydrocarbons (PAHs) with sediment aging, Lumbriculus variegatus were exposed for 4 weeks to sediment core sections taken from a contaminated lake. Core depths included surficial (0 to 4 cm), 4- to 8-, 12- to 16-, 28- to 32-, and 44- to 48-cm sections deposited from approximately 1899 to 1993, and were known to be historically contaminated with PAHs. Bioaccumulation was maximal at the 12- to 16-cm depth (circa 1967) where sediment PAH concentrations were greatest. Accumulation was generally below detection limits in the 0- to 4-cm depths, even though sediment concentrations of some compounds were comparable to those at the 12- to 16-cm depth where accumulation was great enough to generate accurate kinetics curves. Accumulation peaked at about 96 h, then declined over the remainder of the study for the lower-molecular-weight PAHs. For most higher-molecular-weight PAHs, accumulation peaked at about 2 weeks, then declined only slightly after 4 weeks. The differential bioavailability observed between surficial and at-depth core sections raises questions concerning the adequacy of results generated from toxicity and bioaccumulation tests routinely conducted with surficial sediments.
Differences between understorey and canopy in herbivore community composition and leaf quality for two oak species in Missouri

Summary 1. From July 1994 to September 1995, at six censuses, the herbivore community associated with understorey (< 2.5 m height) and canopy (15–20 m) leaves of Quercus alba and Q. velutina was sampled in south-eastern Missouri, U.S.A. 2. Across all censuses, herbivore densities were not significantly different between canopy and understorey for Q. alba and Q. velutina, except in August 1994 when herbivore densities were 60% higher in the canopy on Q. alba. Little significant spatial variation in herbivore densities or community composition was found during the study years. 3. The herbivore community was diverse, consisting of 138 species of leaf-chewing insects. Species richness was significantly greater (by 5–20%) in the understorey than in the canopy for both tree species, and the relative abundance of the main families, different feeding guilds, and most common species differed significantly between understorey and canopy. 4. To determine the extent to which leaf quality explained the observed patterns, percentage nitrogen and protein binding capacity were measured in canopy and understorey leaves of Q. alba and Q. velutina. Per cent nitrogen was higher in canopy leaves for Q. velutina while protein binding capacity was higher in canopy leaves for Q. alba. 5. These results suggest that the herbivore community associated with these two species of Quercus comprises species that appear to respond individually to environmental and biological conditions encountered in the understorey and the canopy.
Symbiotic N2 fixation response to drought

Symbiotic nitrogen fixation is highly sensitive to drought, which results in decreased N accumulation and yield of legume crops. The effects of drought stress on N 2 fixation usually have been perceived as a consequence of straightforward physiological responses acting on nitrogenase activity and involving exclusively one of three mechanisms: carbon shortage, oxygen limitation, or feedback regulation by nitrogen accumulation. The sensitivity of the nodule water economy to the volumetric flow rate of the phloem into the nodule offers a common framework to understand each of these mechanisms. As these processes are sensitive to volumetric phloem flow into the nodules, variations in phloem flow as a result of changes in turgor pressure in the leaves are likely to cause rapid changes in nodule activity. This could explain the special sensitivity of N 2 fixation to drying soils. It seems likely that N feedback may be especially important in explaining the response mechanism in nodules. A number of studies have indicated that a nitrogenous signal(s), associated with N accumulation in the shoot and nodule, exists in legume plants so that N 2 fixation is inhibited early in soil drying. The existence of genetic variation in N 2 fixation response to water deficits among legume cultivars opens the possibility for enhancing N 2 fixation tolerance to drought through selection and breeding.
Incidence of infection and analysis of contributing factors in revision joint arthroplasty over a two-year period

This study examined the incidence of infection and the contributing factors in 166 patients undergoing total joint revision surgery. Of these 32 (19%) had organisms grown from material taken at the local site at the time of revision surgery. Six of the culture-negative patients were clinically suspected of having an infection. With the inclusion of these six, the total incidence of infection in these revision patients was 23%. This is not the incidence of infection in total joint surgery. This is the incidence of infection in patients undergoing revision surgery for whatever reason. The cause of infection in 53% of the cases was either Staphylococcus aureus or coagulase-negative Staphylococci. The Gram-negative bacteria were implicated in only five (15%) of the cases. Many of these infections (31%) were in patients who had had the implant for greater than 7 years. Only 15% of the infections were in patients who had the implant for less than 6 months with an additional 9% being revised in the first year. There were no clinical symptoms or underlying conditions, including allergy, that distinguished the infected from the noninfected group. The infection rate was somewhat higher with the cobalt chromium alloys, somewhat less in the uncemented devices, and somewhat higher in the patients with total knee replacements than those with total hip replacements. The histopathologic analysis revealed that the presence of polymorphonuclear leukocytes (PMNS) was correlated with infection, but most patients with infection had lymphocytes rather than PMNS indicative of a chronic infection. Thus the diagnosis of infection on the basis of histopathology needs to be carefully evaluated. The presence of PMNS is diagnostic for infection, but has a high number of false negatives. The histopathologic data and the data on implantation time indicate that most of these infections are chronic infections. © 1994 John Wiley & Sons, Inc.
Improvement of CAN BUS Performance by Using Error-Correction Codes

In this paper, two variants of the Hybrid Automatic Repeat Request (HARQ) scheme for CAN bus are presented. The basic HARQ uses error-correction code based on the Reed-Solomon (RS) technique and the Cyclic Redundancy Check (CRC) method to detect errors. The second scheme uses the cyclic error-correction method instead of the CRC error-detection method to further improve the throughput. Moreover, the second scheme uses no additional bit overhead when compared with the basic HARQ scheme. This paper presents the performance of the proposed schemes using MATLAB and NS2 simulations. Experimental data of error patterns were used for realistic evaluation. The basic HARQ method corrects 100% of error bursts shorter than 7 bits. When the burst length falls between 7 to 10 the scheme corrects between 86% and 56% of the corrupted frames. Network Simulator (NS2) simulations showed that the throughput increased by 92% when the user message size was increased from the standard 64 bits to 512 bits as a result of reduced overhead per user bit.
Are unreliable release mechanisms conserved from NMJ to CNS

The frog neuromuscular junction (NMJ) is a strong and reliable synapse because, during activation, sufficient neurotransmitter is released to trigger a postsynaptic action potential (AP). Recent evidence supports the hypothesis that this reliability emerges from the assembly of thousands of unreliable single vesicle release sites. The mechanisms that govern this unreliability include a paucity of voltage-gated calcium channels, a low probability of calcium channel opening during an AP, and the rare triggering of synaptic vesicle fusion even when a calcium channel does open and allows calcium flux. Here, we discuss the evidence that these unreliable single vesicle release sites may be the fundamental building blocks of many types of synapses in both the peripheral and central nervous system (PNS and CNS, respectively).
Comprehension of Mathematical Relationships Expressed in Graphs.

In this study, the schema-theoretic perspective of understanding general discourse was extended to include graph comprehension. Fourth graders (n = 204) and seventh graders (n = 185) were given a prior-knowledge inventory, a graph test, and the SRA Reading and Mathematics Achievement Tests during four testing sessions. The unique predictors of graph comprehension for Grade 4 included reading achievement, mathematics achievement, and prior knowledge of the topic, mathematical content, and form of the graph. The unique predictors for Grade 7 were the same except that prior knowledge of topic and graphical form were not included. The results suggest that children should be involved in graphing activities to build and expand relevant schemata needed for comprehension.
Submolecular resolution of single macromolecules with atomic force microscopy

The intrinsically high signal-to-noise ratio of atomic force microscopy (AFM) permits structural determination of individual macromolecules to, at times, subnanometer resolution directly from unprocessed images, avoiding the conditions and possible consequences of averaging over an ensemble of molecules. In this article, we will review some of the most recent achievements in imaging single macromolecules with AFM.
Imaging moving targets from scattered waves

We develop a linearized imaging theory that combines the spatial, temporal and spectral aspects of scattered waves. We consider the case of fixed sensors and a general distribution of objects, each undergoing linear motion; thus the theory deals with imaging distributions in phase space. We derive a model for the data that is appropriate for any waveform, and show how it specializes to familiar results in the cases when: (a) the targets are moving slowly, (b) the targets are far from the antennas and (c) narrowband waveforms are used. From these models, we develop a phase-space imaging formula that can be interpreted in terms of filtered backprojection or matched filtering. For this imaging approach, we derive the corresponding point-spread function. We show that special cases of the theory reduce to: (a) range-Doppler imaging, (b) inverse synthetic aperture radar (ISAR), (c) synthetic aperture radar (SAR), (d) Doppler SAR, (e) diffraction tomography and (f) tomography of moving targets. We also show that the theory gives a new SAR imaging algorithm for waveforms with arbitrary ridge-like ambiguity functions.
Identification of Potentially Avoidable Hospitalizations in Patients With GI Cancer

Purpose To identify and characterize potentially avoidable hospitalizations in patients with GI malignancies. Patients and Methods We compiled a retrospective series of sequential hospital admissions in patients with GI cancer. Patients were admitted to an inpatient medical oncology or palliative care service between December 2011 and July 2012. Practicing oncology clinicians used a consensus-driven medical record review process to categorize each hospitalization as “potentially avoidable” or “not avoidable.” Patient demographic and clinical data were abstracted, and quantitative and qualitative analyses were performed to identify patient characteristics and outcomes associated with potentially avoidable hospitalizations. Results We evaluated 201 hospitalizations in 154 unique patients. The median age was 62 years, and colorectal cancer was the most common diagnosis (32%). The majority of hospitalized patients had metastatic cancer (81%). In all, 53% of hospitalizations were attributable to cancer symptom...
Diffuse Smooth Alopecia

“I am losing my hair,” “my hair is thinning,” “my hairdresser told me that I’m losing my hair” are statements that elicit a common reaction among dermatologists, such as “will I find out what the patient has?,” “will I need to do a biopsy,” “will I have to do hormonal and systemic evaluation,” “will I be able to help the patient?,” and “will the patient have one disorder or more?”.