cssi/SciSciGPT-SciSciNet huggingface dataset:
The role of DNA damage and repair in the function of eukaryotic genes: radiation-induced single-strand breaks and their rejoining in chromosomal and extrachromosomal ribosomal DNA of tetrahymena.

The production and rejoining of single-strand breaks (SSB) in chromosomal DNA and extrachromosomal ribosomal DNA (rDNA) were investigated after sublethal doses of ..gamma.. radiation to exponentially growing Tetrahymena. Hydrogen-3-labeled total nuclear DNA isolated from either control or irradiated cells was heat denatured and electrophoresed in agarose gels containing formaldehyde. Ribosomal DNA was identified by hybridization to (/sup 32/P)rRNA after transferring the DNA from the gels to nitrocellulose strips. It was found that (a) approximately 0.68 SSB is produced in each strand of rDNA exposed to 40 krad; (b) greater than 80% of SSB were rejoined within the first 20 min after irradiation in both chromosomal and rDNA; and (c) the rejoining process in both chromosomal and rDNA proceeded in the presence of inhibitors of protein synthesis, RNA synthesis, or oxidative metabolism. While the majority of SSB induced by 40 krad is rejoined within 20 min after irradiation, the resumption of rRNA synthesis does not occur until 30 min thereafter; it is concluded that the restoration of the normal size of the rDNA template is probably necessary but not sufficient for the resumption of rRNA synthesis.
Differential effects of experimental central sensitization on the time-course and magnitude of offset analgesia

Pain perception is temporally altered during states of chronic pain and acute central sensitization; however, the mechanisms contributing to temporal processing of nociceptive information remain poorly understood. Offset analgesia is a phenomenon that reflects the presence of temporal contrast mechanisms for nociceptive information and can provide an end point to study temporal aspects of pain processing. In order to investigate whether offset analgesia is disrupted during sensitized states, 23 healthy volunteers provided real-time continuous visual analogue scale responses to noxious heat stimuli that evoke offset analgesia. Responses to these stimuli were evaluated during capsaicin-heat sensitization (45°C stimulus, capsaicin cream 0.1%) and heat-only sensitization (40°C stimulus, placebo cream). Capsaicin-heat sensitization produced significantly larger regions of secondary mechanical allodynia compared to heat-only sensitization. Although areas of mechanical allodynia were positively related to individual differences in heat pain sensitivity, this relationship was altered at later time points after capsaicin-heat sensitization. Heat hyperalgesia was observed in the secondary region following both capsaicin-heat and heat-only sensitization. Increased latencies to maximal offset analgesia and prolonged aftersensations were observed only in the primary regions directly treated by capsaicin-heat or heat alone. However, contrary to the hypothesis that offset analgesia would be reduced following capsaicin-heat sensitization, the magnitude of offset analgesia remained remarkably intact after both capsaicin-heat and heat-only sensitization in zones of both primary and secondary mechanical allodynia. These data indicate that offset analgesia is a robust phenomenon and engages mechanisms that interact minimally with those supporting acute central sensitization.
Lyapunov-based cooperative avoidance control for multiple Lagrangian systems with bounded sensing uncertainties

We present a decentralized, real-time, cooperative avoidance control law for a group of nonlinear Lagrangian systems with bounded control inputs, limited sensing ranges, and bounded sensing errors. The control formulation builds on the concept of avoidance control and uses Lyapunov-based analysis to guarantee collision-free trajectories for a group of N vehicles with sensing uncertainties. Advantages of the cooperative avoidance strategy include its easy synthesis with other stable control laws and its null effect on the agent's main task when other vehicles and obstacles are sufficiently away. Two numerical examples are finally presented that illustrate the performance of the proposed control framework.
Red-backed salamander (Plethodon cinereus) as a bioindicator of mercury in terrestrial forests of the northeastern United States

Abstract Despite concerns over the widespread deposition of mercury (Hg) in remote forested areas of the northeastern United States (U.S.), little information is available on the bioaccumulation of Hg in this region's terrestrial fauna. There is a strong need to develop baseline data on appropriate bioindicator species for this area, and here we report Hg concentrations in one of the most widely distributed vertebrates in forested areas, the red-backed salamander (Plethodon cinereus). To inform the use of this species as a bioindicator of Hg accumulation, we assessed ratios of bioavailable methylmercury (MeHg) to total Hg, and techniques for non-destructive sampling along an elevational gradient of increasing forest floor Hg concentrations. Total Hg in body samples was 70% MeHg, and Hg concentrations in tail-clips, which can be collected non-lethally, were positively correlated with body concentrations. Mercury concentrations in salamanders increased 2.4-fold along an increasing elevational gradient of Hg in soils. We conclude that Hg concentrations in P. cinereus can act as a biomonitoring tool for broad areas of remote terrestrial forests, and may help identify regions and landscape characteristics of particular concern for Hg bioaccumulation.
Hidden magnetism and quantum criticality in the heavy fermion superconductor CeRhIn5.

With only a few exceptions that are well understood, conventional superconductivity does not coexist with long-range magnetic order (for example, ref. 1). Unconventional superconductivity, on the other hand, develops near a phase boundary separating magnetically ordered and magnetically disordered phases. A maximum in the superconducting transition temperature T(c) develops where this boundary extrapolates to zero Kelvin, suggesting that fluctuations associated with this magnetic quantum-critical point are essential for unconventional superconductivity. Invariably, though, unconventional superconductivity masks the magnetic phase boundary when T 0 K magnetic field-pressure phase diagram of CeRhIn5 is well described with a theoretical model developed to explain field-induced magnetism in the high-T(c) copper oxides, but in which a clear delineation of quantum-phase boundaries has not been possible. These experiments establish a common relationship among hidden magnetism, quantum criticality and unconventional superconductivity in copper oxides and heavy-electron systems such as CeRhIn5.
Some Evidence About Character and Mate Selection

The authors conducted four studies (total N = 292) about character and mate desirability. In Study 1, undergraduates judged stimuli for attractiveness-physically and as a casual or longterm date. The target was described as faithful, having cheated but stayed with mates, or having cheated and left. Contrary to the hypothesis, men and women were equally affected by both kinds of cheaters. Study 2 replicated Study 1 with nonstudent adults. In Study 3, undergraduates rated a stimulus on the same attractiveness variables. This target had $14 million from winning a lottery or selling a dot-com company. Women, but not men, found the dot-com creator to be more physically attractive than the lottery winner. In Study 4, undergraduates rated someone who sold a cookie-making company or profited from a lucky real estate transaction. Both men and women preferred the cookie-company seller on all three measures of attractiveness.
Effect of in Vivo Injection of Antioxidants on Turkey Fat Stability

Abstract THE turkey lacks the ability to deposit a sufficient quantity of natural antioxidants in its fatty tissues to prevent a relatively rapid onset of oxidative rancidity (Mecchi et al., 1956). Such a situation results in relatively short frozen storage periods, as compared to other common meats, before the turkey is considered unacceptable by consumers. Criddle and Morgan (1951) reported results in which turkeys on zero and low tocopherol diets were judged rancid after 3 months of frozen storage and those receiving high tocopherol diets were rancid after 9 months storage. Hanson and Fletcher (1958) recommended limiting storage of turkey dinners and turkey pies to 6 months or less at −12°C. or lower for optimum retention of quality. Some of the original work on the effect of feeding an antioxidant to improve body fat stability was accomplished by Barnes et al. (1943). They demonstrated that the keeping time of the rat’s. . .
Propagation and quantitation of animal herpesviruses in eight cell culture systems

A comparative study was carried out to determine the relative sensitivities of eight different cell culture systems to six different herpesviruses of animals. The cells used were: OFL (ovine fetal lung), ML (mink lung), FK (ferret kidney), PTK-2 (potoroo kidney), TEK (turkey embryo kidney), ED (equine dermal), BT (bovine turbinate), and PK15 (porcine kidney). The viruses tested were: PRV (pseudorabies) of swine, CPHV (caprine herpesvirus), IBRV (infectious bovine rhinotracheitis virus), DN-599 strain of bovine herpesvirus type 4, EHV-1 (equine herpesvirus), and CHV (canine herpesvirus). On the basis of virus titers obtained and the time of appearance of CPE (cytopathic effects), ML cells were found to be the most useful because of their sensitivity to all six viruses tested. BT and OFL cells were also found to be highly sensitive to all viruses with the exception of CHV.
A physiologically based pharmacokinetic model for intravenous and ingested dimethylarsinic acid in mice.

A physiologically based pharmacokinetic (PBPK) model for the organoarsenical dimethylarsinic acid (DMA V ) was developed in mice. The model was calibrated using tissue time course data from multiple tissues in mice administered DMA V intravenously. The final model structure was based on diffusion limitation kinetics. In general, PBPK models use the assumption of blood flow-limited transport into tissues. This assumption has historically worked for small lipophilic organic solvents. However, the conditions under which flow-limited kinetics occurs and how to distinguish when flow-limited versus diffusion-limited transport is more appropriate, have been rarely evaluated. One important goal of this modeling effort was to systematically evaluate descriptions of flow-limited compared with diffusion-limited tissue distribution for DMA V , using the relatively extensive pharmacokinetic data available in mice. The diffusion-limited model consistently provided an improved fit over flow-limited simulations when compared with tissue time course iv experimental data. After model calibration, an independent data set obtained by oral gavage of DMA V , was used to further test model structure. Sensitivity analysis of the two PBPK model structures showed the importance of early time course data collection, and the impact of diffusion for kidney time course data description. In summary, this modeling effort suggests the importance of availability of organ specific time course data sets necessary for the discernment of PBPK modeling structure, motivated by knowledge of biology, and providing necessary feedback between experimental design and biological modelers.
Intrauterine Infection with Klebsiella Pneumoniae: Report of a Case and Literature Review:

We report a case of intrauterine Klebsiella pneumoniae infection that resulted in premature rupture of membranes and fetal demise at 20 weeks' gestation in a pregnancy achieved by in vitro fertilization. Postmortem findings included massive panlobar pneumonia, the presence of abundant gram-negative, rod-shaped bacteria within the pulmonary air spaces and the lumen of the gastrointestinal tract, and fetal lung and blood cultures positive for Klebsiella pneumoniae. The placenta showed severe acute chorioamnionitis associated with a brisk fetal inflammatory response (umbilical cord and chorionic plate vasculitis). Marked pancreatic fibrosis was noted, indicative of a preceding necrotizing pancreatitis. In spite of this fulminant histopathologic evidence of intrauterine infection, the infection was clinically silent. This represents, to our knowledge, the 1st reported case of fatal intrauterine Klebsiella pneumoniae infection fully supported by conclusive fetal and placental histopathological evidence.
Associations of urinary levels of kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) with kidney function decline in the Multi-Ethnic Study of Atherosclerosis (MESA).

Background Whether elevations in levels of urinary biomarkers of tubular injury (urine neutrophil gelatinase-associated lipocalin [NGAL] and kidney injury molecule 1 [KIM-1]) are associated with future risk of kidney disease has not been investigated. Study Design 1:1 nested case-control study. Setting & Participants 686 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Predictor NGAL and KIM-1 were measured at baseline, expressed as log-transformed continuous variables, and categorized into deciles. Outcomes Kidney function was estimated by cystatin C level using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. Incident CKD stage 3 was defined as estimated glomerular filtration rate (eGFR) 2 and an eGFR decrease >1 mL/min/1.73 m 2 per year, and rapid kidney function decrease was defined as decrease ≥3 mL/min/1.73 m 2 per year. Measurements Cases were defined as persons with eGFR >60 mL/min/1.73 m 2 who subsequently developed incident CKD stage 3 and/or had rapid kidney function decrease by the MESA year-5 visit. Controls were matched for age, sex, race, diabetes, and baseline eGFR. We adjusted for age, hypertension, and presence of albuminuria (albumin-creatinine ratio ≥30 mg/g). Results Of 343 cases, 145 had incident CKD stage 3, 141 had rapid kidney function decrease, and 57 had both. Mean eGFR for controls was 81 ± 10 mL/min/1.73 m 2 at baseline and 80 ± 10 mL/min/1.73 m 2 at follow-up compared with 82 ± 13 and 58 ± 10 mL/min/1.73 m 2 for cases. Each doubling of KIM-1 level (in picograms per milliliter) was associated with an OR of 1.15 (95% CI, 1.02-1.29) for incident CKD stage 3 and/or rapid kidney function decrease. Compared with the lowest 90%, the highest decile of KIM-1 level was associated with an OR of 2.02 (95% CI, 1.15-3.56) for the outcome; these associations were independent of albuminuria. NGAL levels (in nanograms per milliliter) were not associated with incident CKD stage 3 and/or rapid kidney function decrease (OR, 1.04; 95% CI, 0.99-1.10). Results were similar when KIM-1 and NGAL levels were standardized for urine creatinine. Limitations The case-control design limits the ability to account for persons who died or were not available for follow-up. Conclusions Urinary KIM-1 level is associated with future risk of kidney disease independent of albuminuria. Urinary biomarkers of tubular injury are a promising tool for identifying persons at risk of CKD.
Comparison of winter-nocturnal geostationary satellite infrared-surface temperature with shelter-height temperature in Florida

Geostationary satellite surface temperatures derived from a Visible and Infrared Spin Scan Radiometer (VISSR) sensor (10.5 to 12.6 microns) were compared with 1.5-m air temperatures collected by a thermocouple on a traversing vehicle along rural highway transects in Florida, and with two fixed thermographs located in rural and agricultural areas. Statistical comparisons between satellite and 1.5-m observations yielded a mean correlation coefficient of 0.87 and an average sample standard deviation from regression of 1.57 C during clear nights for four winters (1978-1981). The satellite-temperature image of Lake Okeechobee was compared with its geographic outline for areal image registration. Manual overlays of temporal images were repeatable to within one pixel. Satellite-sensed water temperature of Lake Okeechobee was used as an indicator of satellite radiometer repeatability and stability.
Pharmacological distinctions between "active" and "passive" avoidance memory formation as shown by manipulation of biogenic amine active compounds.

Female CF-1 mice were trained either in a passive step-through avoidance or in an active one-way escape avoidance task. The apparent memory for either task (measured 8 days later) was reduced by reserpine dosage immediately after training. Five-hydroxytryptophane, given along with the reserpine, eliminated memory reduction for the passive training; Dopa, given along with the reserpine, did not eliminate memory deficit for the passive training. Five-hydroxytryptophane given along with reserpine did not eliminate the memory deficit for the active training; Dopa given along with the reserpine did eliminate memory reduction for the active training. Implications are discussed.
Hydrogen effects on the tensile properties of 21-6-9 stainless steel

The effect of hydrogen on the mechanical properties of a series of nineteen experimental heats of 21-6-9 stainless steel was investigated. The nineteen material groups covered a variety of forging processes, strength levels, grain sizes, and microstructures. The data show that absorbed hydrogen acts as an interstitial strengthener which increases the flow stress of 21-6-9 similar to the effects of carbon, nitrogen, and other interstitial atoms. The true stress for tensile instability was observed to be ∼1130 MPa for both uncharged and hydrogen charged specimens and appeared to be independent of process variables. Thermal charging and/or tensile testing in high pressure hydrogen indicates this austenitic stainless steel is susceptible to hydrogen-induced cracking at grain boundaries, slip bands, and other interfaces. A lack of hydrogen-induced effects at true stresses below 1100 MPa indicates a lower limit for the hydrogen-induced reduction in interfacial strength. Above a true stress of 1100 MPa the extent of hydrogen induced reductions in interfacial strength is dependent on hydrogen concentration and increases as the hydrogen concentration increases. These observations are discussed in terms of several proposed hydrogen embrittlement theories.
Molecular and biogeochemical evidence for methane cycling beneath the western margin of the Greenland Ice Sheet

Microbial processes that mineralize organic carbon and enhance solute production at the bed of polar ice sheets could be of a magnitude sufficient to affect global elemental cycles. To investigate the biogeochemistry of a polar subglacial microbial ecosystem, we analyzed water discharged during the summer of 2012 and 2013 from Russell Glacier, a land-terminating outlet glacier at the western margin of the Greenland Ice Sheet. The molecular data implied that the most abundant and active component of the subglacial microbial community at these marginal locations were bacteria within the order Methylococcales (59–100% of reverse transcribed (RT)-rRNA sequences). mRNA transcripts of the particulate methane monooxygenase (pmoA) from these taxa were also detected, confirming that methanotrophic bacteria were functional members of this subglacial ecosystem. Dissolved methane ranged between 2.7 and 83 μM in the subglacial waters analyzed, and the concentration was inversely correlated with dissolved oxygen while positively correlated with electrical conductivity. Subglacial microbial methane production was supported by δ13C-CH4 values between −64‰ and −62‰ together with the recovery of RT-rRNA sequences that classified within the Methanosarcinales and Methanomicrobiales. Under aerobic conditions, >98% of the methane in the subglacial water was consumed over ∼30 days incubation at ∼4 °C and rates of methane oxidation were estimated at 0.32 μM per day. Our results support the occurrence of active methane cycling beneath this region of the Greenland Ice Sheet, where microbial communities poised in oxygenated subglacial drainage channels could serve as significant methane sinks.
DNA Demethylation Pathways: Recent Insights

DNA methylation is a major epigenetic regulatory mechanism for gene expression and cell differentiation. Until recently, it was still unclear how unmethylated regions in mammalian genomes are protected from de novo methylation and whether or not active demethylating activity is involved. Even the role of molecules and the mechanisms underlying the processes of active demethylation itself is blurred. Emerging sequencing technologies have led to recent insights into the dynamic distribution of DNA methylation during development and the role of this epigenetic mark within a distinct genome context, such as the promoters, exons, or imprinted control regions. This review summarizes recent insights on the dynamic nature of DNA methylation and demethylation, as well as the mechanisms regulating active DNA demethylation in mammalian cells, which have been fundamental research interests in the field of epigenomics.
A New Quantitative Method for Estimation of Total Combined Length of Mold Fragments in Butter

Summary A method for determination of total combined length of dead mold fragments per gram or milligram of butter has been developed. The procedure consists of dilution of one gram of butter in hot gum solution, spreading a small quantity of this on a glass slide, staining with Newman's stain and examining with low power magnification. The average length of mold filament per field is multiplied by the microscope factor divided by 1000 and results reported in mm. per mgm. of butter. This quantitative method has been of value in studies to determine the total mold fragment content of butter, buttermilk, wash water and cream.
Fetal atrioventricular heart block.

As part of routine prenatal care, the obstetrician of a 25-year-old gravida 1, para 0 woman performed fetal heart-rate monitoring at 22 weeks gestational age. The fetal heart rate was 90 bpm, below the expected range of 120–160 bpm. This finding prompted a subsequent fetal ultrasound and echocardiogram. The ultrasound exam showed no evidence of hydrops. Cardiac anatomy was normal, with 4 appropriately sized chambers, no valvular defects, and no abnormal communications between the right and left circulations. However, the electrocardiogram demonstrated a 2:1 atrioventricular heart block (1 ventricular beat for every 2 atrial beats). Previously, a first-trimester screen to detect fetal aneuploidy had been performed and the results were normal. Results of serologic testing for hepatitis B, varicella, and rubella viruses were consistent with maternal immunity. Results of syphilis and HIV antibody tests were also negative. The expectant mother had no significant medical history, was taking no medications, and had no history or symptoms of autoimmune disease. Fetal bradycardia is defined as a heart rate <110 bpm. The differential diagnosis of fetal bradycardia includes sinus bradycardia, nonconducted atrial bigeminy, and congenital heart block. Sinus bradycardia is often a result of conditions that cause fetal hypoxia, such as maternal hypotension, umbilical cord prolapse, and placental abruption. Nonconducted atrial bigeminy refers to the presence of electrical signals originating from atrial foci outside the sinus node which are not transmitted to the ventricle. Congenital heart block (CHB)2 refers to complete or incomplete dissociation of atrial and ventricular contractions owing to conduction abnormalities. CHB has an incidence of approximately 1 in 20 000 live births. If fetal bradycardia is detected, ultrasound examination and fetal echocardiogram should be performed to assess for structural heart defects in the fetus, such as transposition of the great vessels or atrial septal defect. Additionally, the ultrasound examination …
Structural requirements for the biosynthesis of backbone cyclic peptide libraries

Background: Combinatorial methods for the production of molecular libraries are an important source of ligand diversity for chemical biology. Synthetic methods focus on the production of small molecules that must traverse the cell membrane to elicit a response. Genetic methods enable intracellular ligand production, but products must typically be large molecules in order to withstand cellular catabolism. Here we describe an intein-based approach to biosynthesis of backbone cyclic peptide libraries that combines the strengths of synthetic and genetic methods. Results: Through site-directed mutagenesis we show that the DnaE intein from Synechocystis sp. PCC6803 is very promiscuous with respect to peptide substrate composition, and can generate cyclic products ranging from four to nine amino acids. Libraries with five variable amino acids and either one or four fixed residues were prepared, yielding between 10 7 and 10 8 transformants. The majority of randomly selected clones from each library gave cyclic products. Conclusions: We have developed a versatile method for producing intracellular libraries of small, stable cyclic peptides. Genetic encoding enables facile manipulation of vast numbers of compounds, while low molecular weight ensures ready pharmacophore identification. The demonstrated flexibility of the method towards both peptide length and composition makes it a valuable addition to existing methods for generating ligand diversity.
Defining biomarkers to predict sensitivity to PI3K/Akt/mTOR pathway inhibitors in breast cancer

Summary Background Identification and validation of biomarkers is increasingly important for the integration of novel targeted agents in the treatment of cancer. The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway represents a promising therapeutic target in breast carcinoma, and inhibitors targeting different nodes of the PI3K/Akt/mTOR axis are in development. Identification of biomarkers to help select patients who are most likely to benefit from these treatments is an essential unmet need. Design MEDLINE and international conference abstracts were searched for evidence of markers of sensitivity to PI3K/Akt/mTOR pathway inhibitors in breast cancer patients and preclinical models. Results Preclinical evidence suggests that PI3K/Akt/mTOR pathway aberrations, notably in PIK3CA, may identify a subpopulation of patients with breast cancer who preferentially respond to PI3K/Akt/mTOR inhibitors. However, additional markers are needed to identify all patients with de novo sensitivity to PI3K/Akt/mTOR pathway inhibition. Early clinical studies to validate these biomarkers have as yet been inconclusive. Conclusions Prospective, adequately designed and powered clinical trials are needed to test candidate biomarkers of sensitivity to PI3K/Akt/mTOR pathway inhibitors in patients with breast cancer, and to determine whether certain PI3K/Akt/mTOR pathway inhibitors are more appropriate in different subtypes depending on the pattern of molecular alteration.
The development of brain-machine interface neuroprosthetic devices

The development of brain-machine interface technology is a logical next step in the overall direction of neuroprosthetics. Many of the required technological advances that will be required for clinical translation of brain-machine interfaces are already under development, including a new generation of recording electrodes, the decoding and interpretation of signals underlying intention and planning, actuators for implementation of mental plans in virtual or real contexts, direct somatosensory feedback to the nervous system to refine actions, and training to encourage plasticity in neural circuits. Although pre-clinical studies in nonhuman primates demonstrate high efficacy in a realistic motor task with motor cortical recordings, there are many challenges in the clinical translation of even simple tasks and devices. Foremost among these challenges is the development of biocompatible electrodes capable of long-term, stable recording of brain activity and implantable amplifiers and signal processors that are sufficiently resistant to noise and artifact to faithfully transmit recorded signals to the external environment. Whether there is a suitable market for such new technology depends on its efficacy in restoring and enhancing neural function, its risks of implantation, and its long-term efficacy and usefulness. Now is a critical time in brain-machine interface development because most ongoing studies are science-based and noncommercial, allowing new approaches to be included in commercial schemes under development.
Investigation of potentially pathogenic Clostridium difficile contamination in household environs

As Clostridium difficile spores are resistant to many household cleaning products, the potential for community household contamination is high. The purpose of this study was to assess the prevalence of toxigenic C. difficile from environmental sources from a large urban area. Three to 5 household items or environmental dust was collected from 30 houses in Houston, Texas. A total of 127 environmental samples were collected from shoe bottoms (n = 63), bathroom surfaces (n = 15), house floor dusts (n = 12), or other household surfaces (n = 37). Forty one of 127 samples (32.3%) grew C. difficile. All 41 isolates were positive for toxin A and B genes and no isolate was positive for binary toxin genes. Shoe bottom swab samples had the highest percent of positive samples (25/63; 39.7%) followed by bathroom/toilet surfaces (5/15; 33.3%), house floor dust (4/12; 33.3%), and other surface swabs (7/37; 18.9%). Strains were grouped into 25 different ribotypes, the most prevalent type was 001 (5 strains). In conclusion, a high rate of environmental contamination of C. difficile was observed from community households from a large urban area.
Troponin Is Unlikely to Occur in Bovine and Chick Forebrain

: A search for the presence of troponin in brain reveals that troponin is below 0.00037% of total bovine brain soluble protein. Troponin levels were examined using G-actin-linked Sepharose affinity chromatography and 45Ca binding. The chromatographic and 45Ca binding experiments revealed the presence of several actin and calcium-binding proteins, none of which corresponded to any troponin subunit. In addition, troponin was not found in any chick brain subfraction analyzed, and the level of troponin in chick nerve ending cytoplasm enriched for troponin was less than 0.023%. Considering that substantial amounts of myosin and actin occur in brain, these findings indicate that troponin is not likely to be a regulator of putative brain actomyosin interactions. The significance of these results and their relation to proposed models for neurotransmitter release is discussed.
Role of nitroreduction in the synergistic mutational response induced by mixtures of 1- and 3-nitrobenzo[a]pyrene in Salmonella typhimurium.

Previous studies showed that binary mixtures of the environmental pollutants 1- and 3-nitrobenzo[a]pyrene produced a synergistic mutational response in the Salmonella reversion assay. Since nitroreduction is believed to mediate the direct-acting mutagenicity of the individual compounds, we have examined the role of nitroreduction in the mutagenicity of mixtures of 1 - and 3-nitrobenzo[a]pyrene in the Salmonella plate incorporation assay. While mixtures of 1 - and 3-nitrobenzo[a]pyrene induced up to 183% more revertants in strain TA98 than produced by equivalent amounts of the individual compounds, in the nitroreductase-deficient strain TA98NR the same mixtures only induced up to 57% more revertants than the individual compounds. Analysis of mixtures of 1 - and 3-nitrosobenzo[a]pyrene (the two-electron reduction products of 1 - and 3-nitrobenzo[a]pyrene) for mutation induction in TA98 yielded no evidence of a synergistic effect between the compounds. The mutagenicity of the mixtures was dependent upon the amount of the more mutagenic component. Salmonella cultures were also incubated with mixtures of 1 - and 3-nitrobenzo[a]pyrene, as well as with equivalent amounts of the individual compounds. In two experiments, nitroreductive ability, as measured by the amount of 1 -nitropyrene metabolized to 1 -aminopyrene in 1 hr, was increased 9 to 105% in cultures pretreated with the mixtures as compared with cultures pretreated with the individual compounds. The results of this study support the hypothesis that nitroreduction is a major factor in the synergistic mutational response induced by 1 - and 3-nitrobenzo[a]pyrene in Salmonella typhimurium.
Modern fracture mechanics

Alan Cottrell had a unique ability to impact the metallurgical/materials research community via his fundamental approaches at various length scales and by providing micromechanistic approaches to fracture in crystalline materials, culminating in the macro-mechanics of large-scale engineering structures. His concepts/techniques/analyses have been successfully applied to a range of structural materials and are being applied to an ever-increasing range of more complicated materials systems, ranging from ferrous-based crystalline systems to amorphous metals and biological systems. The field of Modern Fracture Mechanics requires an increasingly complex set of experimental and computational tools to capture material deformation, damage accumulation and failure across multiple size and time scales and builds directly from some of the earliest works and desires of Sir Alan, as reviewed herein.
Crystal gamma-ray detectors for high-energy physics

This report reviews the design characteristics of crystal gamma ray detectors for high energy physics. The unique physics capability of these detectors is the result of their excellent energy resolution, uniform hermetic coverage and fine granularity. To maintain crystal's resolution in situ radiation hardness is a principle requirement. The performance of various heavy crystal scintillators is discussed. A technical approach to solve radiation damage problem by optical bleaching in situ is elaborated.
Emulsification mechanisms and characterizations of cold, gel-like emulsions produced from texturized whey protein concentrate

Abstract A novel supercritical fluid extrusion (SCFX) process was used to successfully texturize whey protein concentrate (WPC) into a product with cold-setting gel characteristics that was stable over a wide range of temperature. It was further hypothesized that incorporation of texturized WPC (tWPC) within an aqueous phase could improve emulsion stability and enhance the rheological properties of cold, gel-like emulsions. The emulsifying activity and emulsion stability indices of tWPC and its ability to prevent coalescence of oil-in-water (o/w) emulsions were evaluated and compared with the commercial WPC80. The cold, gel-like emulsions were prepared at different oil fractions (φ = 0.20–0.80) by mixing oil with the 20% (w/w) tWPC dispersion at 25 °C and evaluated using a range of rheological techniques. Microscopic structure of cold, gel-like emulsions was also observed by Confocal Laser Scanning Microscope (CLSM). The results revealed that the tWPC showed excellent emulsifying properties compared to the commercial WPC in slowing down emulsion breaking mechanisms such as creaming and coalescence. Very stable with finely dispersed fat droplets, and homogeneous o/w gel-like emulsions could be produced. Steady shear viscosity and complex viscosity were well correlated using the generalized Cox–Merz rule. Emulsions with higher viscosity and elasticity were obtained by raising the oil fraction. Only 4% (w/w) tWPC was needed to emulsify 80% (w/w) oil with long-term storage stability. The emulsion products showed a higher thermal stability upon heating to 85 °C and could be used as an alternative to concentrated o/w emulsions and in food formulations containing heat-sensitive ingredients.
Conversations with Lil: A play with Alzheimer's in five scenes and a couple of phone calls

Editors’ note – Elinor Fuchs's family memoir, Making an Exit, the story of her mother Lillian's unusual career and later memory loss, was published in 2005. Since that time Elinor has been invited to speak before many different groups on her experience as a caregiver. On occasion, instead of a talk, she has offered a performance, spliced together from the fragments of conversation she taped with her mother over several years. In these conference performances, Elinor performs both her own words and her mother's, and reads all notes, scene titles, asides, and “stage directions.”
Thermal Characterization of a NASA 30-cm Ion Thruster Operated up to 5 kW

A preliminary thermal characterization of a newly-fabricated NSTAR-derived test-bed thruster has recently been performed. The temperature behavior of the rare-earth magnets are reported because of their critical impact on thruster operation. The results obtained to date showed that the magnet temperatures did not exceed the stabilization Emit during thruster operation up to 4.6 kW. Magnet temperature data were also obtained for two earlier NSTAR Engineering Model Thrusters and are discussed in this report. Comparison between these thrusters suggests that the test-bed engine in its present condition is able to operate safely at higher power because of the lower discharge losses over the entire operating power range of this engine. However, because of the 'burn-in' behavior of the NSTAR thruster, magnet temperatures are expected to increase as discharge losses increase with accumulated thruster operation. Consequently, a new engineering solution may be required to achieve 5-kW operation with acceptable margin.
Optical noise and temporal coherence

Previous articles have been devoted to the study of optical noise as a function of spatial coherence. The present one completes this study by considering temporal coherence. Noise arising from defects in the pupil plane and affecting the high spatial frequencies of an image is notably reduced by white-light illumination. Temporal coherence has little effect on noise arising from defects in the object plane. However, impulse noise due to small isolated defects is reduced in size. Physical arguments are presented to explain these phenomena and a mathematical study of partially coherent imaging in the presence of random defects is given.
Long-term results of combined modality treatment with I-125 implantation for carcinoma of the pancreas

From 1981 to 1987, 81 patients with localized, unresectable carcinoma of the pancreas were treated at Thomas Jefferson University Hospital with a combination of intraoperative Iodine-125 implantation, external beam radiation, and peri-operative systemic chemotherapy. Fifty patients had Stage II disease and 31 patients had Stage III disease. Radioactive Iodine-125 seeds were implanted intraoperatively into the tumor to deliver a minimum peripheral dose of 12,000 cGy over one year. This was followed by external beam radiation (50-55 Gy) and systemic chemotherapy (5-FU, Mitomycin-C +/- CCNU). Incidence of peri-operative mortality was 5% (4/81). Early morbidity was observed in 34% of patients and late complications in 32%. A median survival of 12 months and 2- and 5-year survival rates of 21% and 7% were observed. The determinate 2- and 5-year survival rates were 28% and 13%, respectively. The overall 2- and 5-year survival rates with Stage II disease were 27% and 8% and for Stage III disease, 13% and 3%, respectively (p less than 0.05). The determinate 2- and 5-year survival rates were 34% and 19% for Stage II and 19% and 5% for Stage III disease, respectively (p = 0.08). Local control of disease was achieved in 71% of patients. This combined modality approach appears to have achieved satisfactory local control of primary cancer and long term survival of selected patients.
RESOURCE AVAILABILITY AND PLASTICITY IN OFFSPRING PROVISIONING: EMBRYO NOURISHMENT IN SAILFIN MOLLIES

I report evidence of plasticity in the mode of embryo nourishment by female poeciliid fish raised under contrasting environmental conditions. In two experiments, female sailfin mollies (Poecilia latipinna), raised on high and low levels of food, produced neonates of similar mass and percentage of fat by varying egg size and the amount of supplemental nourishment provided to embryos as they developed. In one experiment, females displayed plasticity in ovum size, but not neonate size; females raised in a low-food and low-salinity treatment produced larger eggs than those raised on higher food levels and at higher salinity. In a second experiment, the amount of nourishment provided to embryos, in addition to that in the egg yolk, was dependent on brood size and maternal food level. Females with small broods were less matrotrophic than those with large broods; female body size and brood size were highly correlated. The brood size at which egg mass equaled neonate mass was smaller for females raised on low levels of food than for females raised on a higher food level treatment. In the second experiment, females from two populations, different from the source of fish for the first experiment, were studied and found to differ in the amount of fat stores remaining after reproduction. Females from a population with low postparturition fat stores displayed greater brood reduction during gestation (via resorption or abortion) and fewer offspring per unit mass than females from the population with more fat. In sailfin mollies, matrotrophy appears to be an adaptation that diminishes the offspring size-offspring number trade-off by permitting a reduction in ovum size and increase in fecundity without compromising neonate size. However, matrotrophic supplementation of yolk nourishment was greatest in relatively large females raised on a restricted food level. Thus, matrotrophy may incur some energetic cost that renders it inefficient for small females and for females with substantial or dependable energy reserves available for reproduction.
Managing Cognitive Demands for Writing: Comparing the Effects of Instructional Components in Strategy Instruction

This article reviews a specific body of writing intervention research, that of component analyses of cognitive strategy instruction. One rationale for examining the effects of individual components comes from meta-analyses, which indicate powerful intervention outcomes for complex strategies, though it is frequently unclear which component has the greatest impact on students' writing. Such information can be used to streamline interventions, and in turn perhaps persuade teachers who are hesitant to employ cognitive strategies to use them as part of their writing programs. Most of the extant literature on this topic has focused on self-regulation, motivation, and peer support, although other component analyses have focused on additional instructional features. Results indicate that these major components confer specific advantages for maintenance and generalization.
Biothics, the Christian Citizen, and the Pluralist Game

The ascendancy of Christian activism in bioethical policy debates has elicited a number of responses by critics of this activism. These critics typically argue that the public square ought to embrace Secular Liberalism (SL), a perspective that its proponents maintain is the most just arrangement in a pluralist society, even though SL places restraints on Christian activists that are not placed on similarly situated citizens who hold more liberal views on bioethical questions. The author critiques three arguments that are offered to defend SL: (1) the golden rule contract argument, (2) the secular reason argument, and (3) the err-on-the-side-of-liberty argument. The author concludes that each of these arguments fail to support SL.
The use of statistical tools to estimate the uncertainty of phase composition measurements determined by gas chromatography for mixtures of 2-methyl-2-propanol, water, and n-tetradecane at 25°C

Abstract A gas chromatograph equipped with a capillary column provided a quantitative measure of liquid-liquid phase compositions for the system 2-methyl-2-propanol, water, and n-tetradecane. The internal standard technique was used to generate calibration curves for the gas chromatograph. The uncertainty of each measured composition was determined using the statistical techniques outlined by Cox (1971) for lines regressed through the origin. The results of that evaluation show that the interval estimate generally ranged from 0.3 to 3 percent of the measured value, depending on the component being analyzed.
Iodometric measurement of lipid hydroperoxides in human plasma

Abstract Many assay techniques have been used to measure lipid hydroperoxides in plasma, including absorbance of conjugated dienes and reactivity with thiobarbituric acid. Because these measurements are not specific for lipid hydroperoxides, we modified an existing iodometric method to correct for interfering phenomena and to provide a more specific measurement of the lipid hydroperoxide content of plasma. To ensure reproducible extraction of hydroperoxides from the many possible forms in plasma, the plasma was treated to hydrolyze enzymatically cholesterol ester, triglycerides, and phospholipids, and the nonesterified fatty acid peroxides were then extracted with ethyl acetate. Extracted lipids were reacted with potassium iodide in acetic acid and methylene chloride, and the resulting triiodide ion (I3−) was measured spectrophotometrically. Correction for nonoxidizing chromophores was made after back-titration of the triiodide ion to iodide with sodium thiosulfate and other non-peroxide oxidants were estimated by their resistance to reduction with glutathione peroxidase. Recovery of added hydroperoxide standards provided routine validations of the procedure's efficiency. The method indicated that insignificant amounts of hydroperoxide may be in the less polar lipids, but the total amount of lipid hydroperoxide esterfield in the plasma lipids of apparently healthy humans may be as much as 4.0 ± 1.7 μM.
A novel polyisoprenyl phosphate signaling cascade in human neutrophils.

: Activation of neutrophil (PMN) surface receptors can evoke inflammation and tissue injury via aberrant release of excess effectors. The molecular mechanisms involved in host protection and control of PMN responses have yet to be defined. As Billah and coworkers (1989) and Exton (1997), for example, have pointed out, phospholipase D (PLD) signaling is known to play a pivotal role in PMN activation. Here, we determined the relationship between polyisoprenyl phosphate (PIPP) remodeling and PLD signaling and their impact in activation of PMN receptors by “proinflammatory” (leukotriene B4), and “anti-inflammatory” (aspirin-triggered lipoxin A4) ligands. Activation of the leukotriene B4 receptor initiated a rapid (within seconds) decrement in presqualene diphosphate (PSDP), activation of PLD and production of superoxide anions. This contrasts with activation of the LXA4 receptor by an aspirin-triggered lipoxin A4 mimetic that before leukotriene B4 gave an inverse relationship with rapidly increasing PSDP levels, and inhibition of both PLD activity and superoxide generation. PSDP proved to be a potent and direct-acting inhibitor of PLD (rhPLD1b: Ki = 5.9 nM), a property not shared by structurally related endogenous lipids. This PIPP also interacted with Src homology domains, selectively targeting SH2 and not SH3 domains. These results indicate a role for ligand-driven rapid PIPP remodeling as an early switch and “stop” signaling event that controls PMN. Moreover, they indicate that PSDP directly down-regulates PMN signaling events via select protein-targeted interactions controlling intracellular responses relevant in inflammation.
Editorial: Resources for the computer security and information assurance curriculum

This editorial introduces the articles in this companion issue to the first JERIC special issue on Computer Security and Information Assurance Curriculum. It includes an article that supports making computer security education more accessible through a portable network, and one on lessons learned in developing a workshop for educators. Other articles outline laboratory exercises especially suitable for distance or online education, illustrate ways to teach students about threats, and provide approaches to classroom discussion of disaster recovery.