cssi/SciSciGPT-SciSciNet huggingface dataset:
The effects of non-periodic microstructure and defects on the compressive strength of two-dimensional cellular solids

Abstract The utility of unit cell models that assume periodic microstructures may be limited when applied to cellular materials that have non-periodic microstructures. We analyzed the effects of non-periodic microstructure and defects on the compressive failure behavior of Voronoi honeycombs using finite element analysis. Our results indicate that the non-periodic arrangement of cell walls in random Voronoi honeycombs (with cells approximately uniform in size) results in higher strains in a small number of cell walls compared to periodic, hexagonal honeycombs. Consequently, the Voronoi honeycombs were approximately 30% weaker than periodic, hexagonal honeycombs of the same density. The strength difference between the Voronoi and periodic honeycombs depended slightly on density, due to density-dependent interactions between failure modes (i.e. plastic collapse and elastic buckling). Defects, introduced by removing cell walls at random locations, caused a sharp decrease in the effective mechanical properties of both Voronoi and periodic honeycombs (e.g. a 10% reduction in density due to defects caused a 60% reduction in the strength of Voronoi honeycombs). The sensitivity to defects was comparable for thin-walled, elastomeric honeycombs (relative density 0.015) and for thicker walled, plastic honeycombs (relative density 0.15). The properties degraded to zero when 35% of the cell walls were removed, consistent with the percolation limit for a two-dimensional network of hexagonal cells. When four or more adjacent cell walls were removed, the localized band of cell collapse passed through the defect site and the effective strength and modulus were reduced, indicating that even those defects which have a negligible effect on density can alter the failure pattern as well as the effective properties of honeycombs with cells of approximately equal size and strength.
antiangiogenic Treatment of Mesenteric Desmoid Tumors With Toremifene and Interferon Alfa-2b: Report of Two Cases

PURPOSE: Desmoid tumors are uncommon, benign, fibrous lesions occurring sporadically and in association with familial adenomatous polyposis. Typical clinical features include a locally aggressive behavior, an unpredictable course, and a high propensity for recurrence after surgical resection. There are no standard medical or surgical approaches, and no markers for monitoring medical therapy of desmoid tumors. METHODS: We report two cases of mesenteric desmoid tumors treated with interferon alfa-2b and toremifene, a novel regimen devised to block angiogenesis. Pre- and posttreatment desmoid tumor tissues were obtained in one patient during a repeat resection for recurrent stenosing Crohn’s disease and examined for mean vessel count and cellular proliferation levels by immunostaining for the endothelial surface antigen CD31 and the proliferation associated nuclear antigen, Ki-67, respectively. We assessed plasma D-dimers, a potential marker of angiogenic activity, and followed this throughout the course of antiangiogenic therapy in our two patients. RESULTS: Examination of posttreatment tissue revealed a significant decrease in microvessel density (P < 0.02) and Ki-67-positive nuclei (P < 0.0001) compared with pretreatment tissue. Both patients demonstrated a prompt and sustained drop in previously elevated plasma D-dimer levels, which correlated clinically with lesion regression and sustained remission. CONCLUSIONS: Treatment with toremifene and interferon alfa-2b was successful and well tolerated in our two patients. Our data suggest a combined antiangiogenic and antiproliferative mechanism of action. Furthermore, normalization of previously elevated plasma D-dimers may emerge as a strategy to monitor treatment efficacy in mesenteric desmoid tumors.
House for an Ancestor: Introducing Design through Visions in Clay

This article describes an innovative attempt to teach environmental design to beginning students at the University of California, Berkeley. The particular project was built around the instructors' desire to have students work in clay, a fluid modeling medium, and to strive for personal engagements with the notions of history and culture. Clay was chosen because of the difficulties beginning students often have developing good ideas by means of more traditional methods of representation. Its lifelike properties helped students' realize their ideas almost immediatlely and allowed building and designing to become a single act. The emphasis on engagement with history and culture was intended to lead students away from shallow imitations of popular imagery toward deeper personal resources of design. The project began with each student being asked to create a historical narrative that outlined the housing needs of a real or fictitious ancestor. Such personal investigations were particularly effective in a multi...
OPC-8212 in the treatment of congestive heart failure: results of a pilot study.

To characterize the effects of OPC-8212, a quinolone inotropic agent, in patients with heart failure, we utilized invasive hemodynamics, exercise testing, 24-hour ambulatory electrocardiograms, and two patient self-assessment questionnaires, before and after 1 month of treatment with OPC-8212, in 17 patients with moderate to severe congestive heart failure. There were no significant changes from baseline in heart rate (83 +/- 8 beats/min), mean arterial pressure (70 +/- 15 mmHg), pulmonary wedge pressure (18 +/- 7 mmHg), or cardiac index (2.3 +/- 0.4 L/min/m2) following treatment with OPC-8212. Both exercise duration (5.3 +/- 1.6 min) and peak oxygen consumption (12.0 +/- 2.9 mL/kg/min) were unchanged by OPC-8212. Two independent patient self-assessment scores, the Sickness Impact Profile and the Minnesota Living with Heart Failure Questionnaire, showed improvements from 6.8 to 5.4 and 49 to 38, respectively (both p less than .05), suggesting that the patients reported an improvement in daily functioning. The median ventricular premature contraction count and frequency were reduced from 1,118 beats to 243 beats (p less than 0.05) and 11/1,000 beats to 2.4/1,000 beats (0.05 less than p less than 0.10), respectively. Two patients developed agranulocytosis during longer-term treatment following this 1-month study. These data demonstrate that OPC-8212 did not have significant effects on hemodynamics or exercise tolerance. However, the improvement in patient self-assessment scores and the trend for improvement in ventricular arrhythmia profiles suggest that OPC-8212 may have some benefit for patients with congestive heart failure, but additional placebo-controlled, double-blind studies are necessary.
Vessel injuries of the head and neck presenting in mandibular fractures

Objective Extracranial vascular injuries of the head and neck are relatively underdiagnosed in patients with acute trauma and can carry devastating sequelae. We wished to identify the correlation between mandibular fractures and injuries to major vessels of the head and neck. Study Design A retrospective review of our trauma registry was performed for the 1993-2007 period. The data on all mandibular fractures were collected. Results A total of 2288 patients presented to Parkland Memorial Hospital with mandibular fractures, of whom 47 (2%) had an injury to a major vessel of the neck. Nearly half, 23 (48.9%), were the result of high-velocity penetrating injuries, namely gunshot wounds, whereas 17 (36.2%) were the result of high-velocity blunt motor vehicle or motorcycle collisions. Conclusions Patients who sustain a mandibular fracture in the setting of a high-velocity mechanism should be approached with the possibility of vascular injury of the great vessels of the neck kept in mind.
The clinging position of the bulbocapninized cat.

Abstract After administration of bulbocapnine to cats (30–40 mg/kg) the animals can maintain for considerable periods of time a clinging position in which they hang by the flexed and adducted forelegs from a support. This position can be maintained by cats in which vision has been excluded, by labyrinthectomized animals, by cats in which the ganglia of the upper three spinal nerves have been excised, and by preparation in which the paws have been denervated. The only sensory input which is indispensable for the clinging position is that from the proprioceptors of the front legs. Although the sensory input from the labyrinths, the neck, and the paws are not necessary for the clinging attitude of the bulbocapninized cat, they can modify this position. The labyrinths prevent clinging when the animal is in the upside down position; the labyrinthectomized preparation does cling under these circumstances. Dorsal extension of the neck results in a loss of the flexor tone in the front legs. When the paws contact a support the bulbocapninized animal often responds with a grasping movement which enables the cat to get a good hold of the support. Stimulation of pressure receptors by bandaging the head causes a dorsal extension of the head in the bulbocapninized clinging cat. The dorsal extension produces secondarily a loss of the flexion tone in the front legs. The animal then usually lets go of the support and falls down. This “backfall reaction” of the bandaged bulbocapninized cat can be prevented by severing bilaterally the trigeminal nerve and the upper spinal nerves. The midbrain (and perhaps the hypothalamus) must be in functional connection with the spinal cord for the preparation to be able to maintain the clinging position.
Stability analysis of the discrete-data Large-Space-Telescope system

This paper considers the application of the discrete describing function to the stability analysis of the Large-Space Telescope (LST) system. An analytical model of the CMG gimbal friction is derived, which is then used to arrive at a closed-form analytical expression for the discrete describing function of the nonlinearity. The analysis is used for the study of the fine-pointing stability of the LST vehicle. Simulation results corroborate the conclusions from the analytical analysis.
DEA and pain practitioners: common goals, adversarial stance?

Dr. Heit has well articulated the conundrum in which those of us who treat pain find ourselves, and the path that led to the present situation. While there are several points of minor disagreement, the major problems are two—the change involving the “do not fill until” rule and the change in attitude. Part of our difficulty is inescapable. Most medical decisions affect only patients, and therefore judgments are an issue between practitioner and patient. In the case of controlled substances (CS), however, our prescriptions have a demonstrable impact on the larger society. Given even a weak relationship between prescriptions for a substance and negative …
Low NOx Heavy Fuel Combustor Program

The 'low nitrogen oxides heavy fuel combustor' program is described. Main program objectives are to generate and demonstrate the technology required to develop durable gas turbine combustors for utility and industrial applications, which are capable of sustained, environmentally acceptable operation with minimally processed petroleum residual fuels. The program will focus on 'dry' reductions of oxides of nitrogen, improved combustor durability, and satisfactory combustion of minimally processed petroleum residual fuels. Other technology advancements sought include: fuel flexibility for operation with petroleum distillates, blends of petroleum distillates and residual fuels, and synfuels (fuel oils derived from coal or shale); acceptable exhaust emissions of carbon monoxide, unburned hydrocarbons, sulfur oxides and smoke; and retrofit capability to existing engines.
Immunoreactive fibroblast growth factor (FGF) in a transplantable chondrosarcoma: Inhibition of tumor growth by antibodies to FGF

Using a radioimmunoassay for bovine pituitary fibroblast growth factor (FGF), we have established the presence of the immunoreactive mitogen in extracts of a transplantable mouse chondrosarcoma. Both neutral and acidic extracts of the tumor contain an immunoreactive FGF (ir-FGF) that cross-reacts in a parallel and dose-dependent fashion in the radioimmunoassay. The ir-FGF is retained on heparin-Sepharose affinity columns and can be detected in the same molecular weight forms as rat pituitary FGF. Mice (C57/B1) inoculated with the tumor (10 mg, im) show a decreased rate of tumor growth when passively immunized with the antiserum to FGF. The results establish the presence of FGF in this tumor and implicate its role in the etiology of its development.
The affinity of the fucose-binding lectin from Lotus tetragonolobus for glycopeptides and oligosaccharides accumulating in fucosidosis.

Abstract— The affinity of the fucose-binding lectin from Lotus tetragonolobus for fuco-oligosaccharides accumulating in the brain and other tissues of a patient with fucosidosis was studied by two methods: by inhibition of the co-precipitation of the lectin with porcine stomach mucin and by one-step affinity chromatography on a column of the lectin bound to Sepharose-4B. Both methods indicated that the lectin had greater affinity for the disaccharide Fuc(α, 1-6)GlcNAc than for either the main fucosidosis storage material in brain, a fuco-dekasaccharide, or the heterogeneous fuco-glycopeptide fractions obtained from normal human and rat brain glycoproteins. Our results suggest that the fucose residue linked α(1-6) to the N-acetylglucosamine residue involved in the N-glycosidic linkage to asparagine is not available to the lectin in the intact N-glycosidic chains of normal brain glycopeptide fractions and that the lectin has poor affinity for the Fuc(α, 1-3)GlcNAc linkage in rat brain glycoproteins.
Retinal Arterial Occlusions in Young Adults

Purpose To determine the cause, associated factors, visual results, and systemic morbidity in patients less than 40 years old with retinal arterial occlusions. Methods We studied 27 eyes with nontraumatic retinal arterial occlusions in 21 patients less than 40 years old (range, 22 to 38 years; mean, 28 years). Results Of the 21 patients, branch retinal artery (arteriolar) occlusion occurred in 15 (71%), central retinal artery occlusion occurred in five (24%), and cilioretinal artery occlusion occurred in one (5%). Retinal artery occlusions were bilateral in six patients (29%) and occurred in 14 women (67%). Emboli were identifiable in seven patients (33%). Cardiac valvular disease was the most commonly recognized etiologic agent and was present in four patients (19%). Various associated factors leading to a hypercoagulable state or embolic condition were identified in 19 patients (91%). Conclusion Retinal arterial occlusions in young adults occur via multiple mechanisms. Systemic evaluation allows detection of a risk factor for retinal arterial occlusive disease in most patients.
Neuroanatomy of the normal prostate.

BACKGROUND The prostate is a richly innervated organ, but its neuroanatomy has not been throughly mapped and analyzed quantitatively. METHODS We selected prostates from autopsy cases of cancer-free patients aging from their 40's to 70's, and histologic sections were immunostained with S-100. Nerve density hotspots were mapped, photographed, and analyzed for nerve area. RESULTS Innervation of the peripheral zone was found to be significantly greater than the transition zone (P < 0.0006), which is in turn significantly more innervated than BPH (P < 0.007). The posterior capsule has significantly more nerve area than the anterior capsule (P < 0.0001). Highest innervation was seen in the neurovascular bundles and seminal vesicles, with the lowest in transition zone and BPH. When compared to increasing patient age, both peripheral zone and overall innervation tended to decrease. CONCLUSIONS These results are quantitative in nature, performed in cancer-free patients ranging over four different decades of age. We plan to soon compare this profile with our developing profile of cancerous prostates, hoping to learn more about interactions between nerves and prostate cancer. © 2005 Wiley-Liss, Inc.
The Role of Pain in Understanding Racial/Ethnic Differences in the Frequency of Physical Activity Among Older Adults

Objectives: To evaluate racial/ethnic differences in physical activity among White, Black, and Hispanic adults aged 65 years and older, and to assess the potential role of pain as a mediator. Methods: Analyses were based on data from the 2008 Health and Retirement Study. Logistic regression was used to evaluate associations between race/ethnicity and pain and the odds of regular physical activity. Results: Compared to Whites, the odds of both light physical activity and moderate/vigorous physical activity were lower among Blacks, but not Hispanics. A graded inverse association between levels of pain severity and the odds of physical activity was found, but pain did not mediate racial/ethnic differences in physical activity. Discussion: When compared to Whites, older Blacks appear to have relatively low rates of physical activity even without comparatively high levels of pain, while older Hispanics experience relatively high rates of pain, but are perhaps more resilient to the effects of pain on physical activity. Language: en
Packet Spacing: An Enabling Mechanism for Delivering Multimedia Content in Computational Grids

Streaming multimedia with UDP has become increasingly popular over distributed systems like the Internet. Scientific applications that stream multimedia include remote computational steering of visualization data and video-on-demand teleconferencing over the Access Grid. However, UDP does not possess a self-regulating, congestion-control mechanism; and most best-effort traffic is served by congestion-controlled TCP. Consequently, UDP steals bandwidth from TCP such that TCP flows starve for network resources. With the volume of Internet traffic continuing to increase, the perpetuation of UDP-based streaming will cause the Internet to collapse as it did in the mid-1980's due to the use of non-congestion-controlled TCP. To address this problem, we introduce the counter-intuitive notion of inter-packet spacing with control feedback to enable UDP-based applications to perform well in the next-generation Internet and computational grids. When compared with traditional UDP-based streaming, we illustrate that our approach can reduce packet loss over 50% without adversely affecting delivered throughput.
Oral health‐related quality of life among low‐income adults living with HIV

Objectives: To explore oral health-related quality of life and its correlates among low-income human immunodeficiency virus (HIV)-positive patients receiving primary HIV care. Methods: Data were from a randomized experimental trial evaluating an intervention to increase use of oral health services by low-income HIV-positive adults. Interviews were conducted in English or Spanish among 594 adults receiving HIV medical care but not dental care. Oral health-related quality of life was measured with the 49-item Oral Health Impact Profile (OHIP-49). Primary predictor variables included measures of HIV disease: duration of HIV infection, CD4 cell count, and HIV viral load. Other predictors included sociodemographic and behavioral factors. Results: Overall, 62.6 percent of participants had experienced at least one oral health impact very often or fairly often in the 4 weeks preceding the survey, with a mean of 5.8 impacts. The mean number of impacts was significantly higher for women, the unemployed, those living in temporary housing, and current smokers. Neither the prevalence nor the mean number of impacts differed significantly by duration of HIV infection, CD4(+) T lymphocyte cell count, or HIV viral load. In bivariate analysis, women had higher mean OHIP-49 scores than men overall (62.6 versus 50.5, P < 0.05) and for most subscales, indicating that women experienced more oral health impacts. In the final multivariate model, significant correlates of OHIP-49 were sex, race/ethnicity, living situation, and smoking status. Conclusions: Oral health impacts are prevalent among adults in South Florida living with HIV, particularly among women, cigarette smokers, those in prison or other institutional settings, and certain racial and ethnic groups.
Low-dose mirtazapine increases genioglossus activity in the anesthetized rat.

Study Objectives: To examine the effects of mirtazapine on genioglossus and diaphragmatic electromyogram activity in the anesthetized rat. Design: Parallel-group study. Subjects: Sprague-Dawley adult male rats, 10 in each of 3 groups were studied. Interventions: After anesthesia with 1.2 g/kg of urethane, a tracheostomy and bilateral vagotomy were performed. Femoral arterial and venous lines were placed, and fine wire hook electrodes were implanted into the genioglossus and diaphragm muscles. Measurements: After a baseline period of measurement, either saline, 0.5 mg/kg of mirtazapine, or 5.0 mg/kg of mirtazapine was injected via the intraperitoneal route, and measurements were made for the next 3 hours. The average peak and tonic values of the moving time average of the genioglossus and diaphragm electromyogram for hours 1, 2, and 3 were determined and expressed as a percentage of the corresponding average value during the baseline (preinjection) monitoring period. Results: At 0.5 mg/kg of mirtazapine, the peak genioglossus electromyogram was significantly higher than in control conditions over hours 2 and 3. At 5.0 mg/kg of mirtazapine, the genioglossus electromyogram was significantly lower than in control conditions for the first 2 hours of monitoring. The peak diaphragmatic electromyogram was slightly but significantly lower in the mirtazapine 5.0-mg/kg group than in controls. Conclusions: Mirtazapine, at a dose similar to one used clinically, increased genioglossus activity. We hypothesize that, at this dose, the ability of mirtazapine to increase serotonin and norepinephrine or block type-3 serotonin receptors predominated. At the higher dose of mirtazapine, the type-2 blockade effect predominated and genioglossus activity decreased.
A convex framework for optimal investment on disease awareness in social networks

We consider the problem of controlling the propagation of an epidemic outbreak in an arbitrary network of contacts by investing on disease awareness throughout the network. We model the effect of agent awareness on the dynamics of an epidemic using the SAIS epidemic model, an extension of the SIS epidemic model that includes a state of “awareness”. This model allows to derive a condition to control the spread of an epidemic outbreak in terms of the eigenvalues of a matrix that depends on the network structure and the parameters of the model. We study the problem of finding the cost-optimal investment on disease awareness throughout the network when the cost function presents some realistic properties. We propose a convex framework to find cost-optimal allocation of resources. We validate our results with numerical simulations in a real online social network.
An SS1–SS2 β-barrel structure for the voltage-activated potassium channel

To examine the feasibility of a beta structure for the pore-lining region of the voltage-gated potassium channel, we have characterized a family of 12 antiparallel beta-barrels. Each is comprised of four identical pairs of beta-strands organized with approximate 4-fold symmetry about a channel axis. The C- and N-termini of the beta-strand pairs are assumed to be at the extracellular end of the channel, and each pair is connected by a hairpin turn at the intracellular end of the channel. The models differ in the residues located in the hairpin turn and in the orientation of the two strands of each pair in the barrel, i.e. whether the C-terminus of a pair is clockwise (CW) or counterclockwise (CCW) from the N-terminus when the channel is viewed from outside the cell. Following known structure precedents and potential energy predictions, the barrel is assumed to be right-twisting in all cases. All models have crowded layers of inward-projecting aromatic side-chains near the center of the channel which could regulate channel selectivity. The models with an odd number of amino acids in the hairpin turn have the advantage of predicting that F433 points into the barrel, but the disadvantage that V438 does not. Of these models, two of the models are most consistent with the external tetraethylammonium (TEA) block data, and of those, one (T439 CCW 3:5) is most consistent with the internal TEA block data.
Voluntary wheel running attenuates ethanol withdrawal-induced increases in seizure susceptibility in male and female rats

We recently found that voluntary wheel running attenuated ethanol withdrawal-induced increased susceptibility to chemoconvulsant-induced seizures in male rats. Since female rats recover from ethanol withdrawal (EW) more quickly than male rats across several behavioral measures, this study was designed to determine whether the effects of exercise on EW seizures also exhibited sex differences. Animals were maintained under no-wheel, locked-wheel or free-wheel conditions and ethanol was administered by liquid diet for 14 days with control animals pair-fed an isocaloric diet, after which seizure thresholds were determined at 1 day or 3 days of EW. Consistent with previous reports, females ran significantly more than males, regardless of diet condition. Introduction of the ethanol-containing liquid diet dramatically increased running for females during the day (rest) phase, with little impact on night phase activity. Consistent with previous reports, EW increased seizure susceptibility at 1 day in non-exercising males and females and at 3 days in males. These effects were attenuated by access to running wheels in both sexes. We also assessed the effects of sex, ethanol diet and exercise on ethanol clearance following an acute ethanol administration at 1 day EW in a separate set of animals. Blood ethanol concentrations at 30 min post-injection were lower in males, ethanol-exposed animals, and runners, but no interactions among these factors were detected. Interestingly, females displayed more rapid ethanol clearance than males and there were no effects of either diet or wheel access on clearance rates. Taken together, these data suggest that voluntary wheel running during ethanol administration provides protective effects against EW seizures in both males and females. This effect may be mediated, in part, in male, but not in female rat, by effects of exercise on early pharmacokinetic contributions. This supports the idea that encouraging alcoholics to exercise may benefit their recovery.
A constrained motion algorithm for the Shuttle Remote Manipulator System

In the past decade, research advances in robot dynamic simulation have included algorithms for space robots operating as open chain mechanisms and earth-bound robot systems operating under motion constraints. Few researchers, however, have investigated a combination of these conditions, i.e., a space robot performing closed chain operations. This article presents a generalized formulation of the dynamic equations for a space-based robot in both open and closed chain kinematic configurations; this generalization represents a consolidation of several specialized formulations found in the current literature. Using this formulation, we present the development of new mathematical models and algorithms for constrained dynamics of the SRMS and their use in supplementing the on-orbit element simulation (OES) developed by NASA and Lockheed Engineering and Sciences Company (LESC). Emphasis is placed on maximizing computational efficiency in order to achieve real time implementation and on minimizing modifications to the original open chain OES code. Simulation results for grasping a fixed payload and frictionless planar sliding of a payload are provided. Constraint violations are minimized using a simple proportional/derivative control technique. >
Instantaneous concentration field measurement technique from flow visualization photographs

A method of measuring the instantaneous concentration field in a planar section of a dyed turbulent flow is described. Negatives of photographed laser-sheet induced fluorescence are digitized and then computer processed to give the concentration distribution of the dye. A simple calibration procedure to account for the film characteristics is presented. This calibration also compensates for non-uniformities in the illumination of the flow field, irregularities in the illumination of the photographic negative and differences between characteristics of the individual digitizing light sensors of the digitizer. The method is illustrated with a cross-section containing the jet axis of the instantaneous concentration field of the entrained fluid from a small source outside of a circular turbulent jet.
Modelling of Waste Form Performance and System Release

Kinetic and thermodynamic approaches to the derivation of long-term release rates of species from defense waste glass are reviewed. It is concluded that at high flow rates kinetic factors are pre-dominant, while at low flow rates saturation of the aqueous medium with respect to major matrix elements, particularly with respect to silica present in the glass and in its alteration products, becomes a controlling factor. Quantitative calculations indicate that under likely repository conditions the release rates can be expected, in general, to fall below the NRC criterion of 10−5 yr−1.
Tubular precipitation structures: materials synthesis under non-equilibrium conditions

Inorganic precipitation reactions are known to self-organize a variety of macroscopic structures, including hollow tubes. We discuss recent advances in this field with an emphasis on experiments similar to ‘silica gardens’. These reactions involve metal salts and sodium silicate solution. Reactions triggered from reagent-loaded microbeads can produce tubes with inner radii of down to 3 mm. Distinct wall morphologies are reported. For pump-driven injection, three qualitatively different growth regimes exist. In one of these regimes, tubes assemble around a buoyant jet of reactant solution, which allows the quantitative prediction of the tube radius. Additional topics include relaxation oscillations and the templating of tube growth with pinned gas bubble and mechanical devices. The tube materials and their nano-to-micro architectures are discussed for the cases of silica/Cu(OH)2 and silica/Zn(OH)2/ZnO tubes. The latter case shows photocatalytic activity and photoluminescence.
DNA Synthesis in Strains of Escherichia coli K12 with Temperature-sensitive DNA Ligase and DNA Polymerase I

Abstract The net DNA synthesis that persists at the restrictive temperature in the conditional lethal DNA ligase mutant Escherichia coli lig ts7 is semiconservative, suggesting that although the rate of joining of 10 S “Okazaki fragments” in the mutant is greatly reduced, it is nevertheless sufficient to permit continued progression of the replication fork and the initiation of new rounds of replication. DNA synthesis in E. coli lig ts7 of a phage (P2) that replicates its chromosomes unidirectionally is discontinuous on both strands. A double mutant of E. coli K12, ( lig ts7 pol A12), has been constructed which bears a temperature-sensitive mutation ( pol A12) in the structural gene for DNA polymerase I in addition to the lig ts7 mutation. Joining of the Okazaki fragments in the double mutant occurs at a slower rate than in either the lig ts7 or pol A12 parents. In contrast to the behavior of the single mutants, DNA synthesis in the double mutant stops abruptly upon shift from 25 °C to 42 °C.
The Declining Status of Minorities in the New York City Construction Industry

Does the employment status of minorities suffer when government downplays affirmative action efforts? This study analyzes the relative status of minority businesses and construction employees in New York City's construction industry. Ed Koch, New York City mayor from 1978 to 1990, chose to downplay the active affirmative action efforts of his predecessors. We find that Black employees lost ground relative to Whites, particularly in the construction-skilled trades. Furthermore, minority-owned small businesses in construction are shown to be smaller, more failure-prone, and less viable overall, relative to White firms generally and woman-owned businesses specifically. Absent affirmative pressure from government, minorities are unlikely to make progress or even hold their own in the New York City area construction industry.
Defects in Translational Regulation Mediated by the α Subunit of Eukaryotic Initiation Factor 2 Inhibit Antiviral Activity and Facilitate the Malignant Transformation of Human Fibroblasts

Suppression of protein synthesis through phosphorylation of the translation initiation factor alpha subunit of eukaryotic initiation factor 2 (eIF2alpha) is known to occur in response to many forms of cellular stress. To further study this, we have developed novel cell lines that inducibly express FLAG-tagged versions of either the phosphomimetic eIF2alpha variant, eIF2alpha-S51D, or the phosphorylation-insensitive eIF2alpha-S51A. These variants showed authentic subcellular localization, were incorporated into endogenous ternary complexes, and were able to modulate overall rates of protein synthesis as well as influence cell division. However, phosphorylation of eIF2alpha failed to induce cell death or sensitize cells to killing by proapoptotic stimuli, though it was able to inhibit viral replication, confirming the role of eIF2alpha in host defense. Further, although the eIF2alpha-S51A variant has been shown to transform NIH 3T3 cells, it was unable to transform the murine fibroblast 3T3 L1 cell line. To therefore clarify this issue, we explored the role of eIF2alpha in growth control and demonstrated that the eIF2alpha-S51A variant is capable of collaborating with hTERT and the simian virus 40 large T antigen in the transformation of primary human kidney cells. Thus, dysregulation of translation initiation is indeed sufficient to cooperate with defined oncogenic elements and participate in the tumorigenesis of human tissue.
Insect predators and augmentative biological control of balsam twig aphid (Mindarus abietinus Koch) (Homoptera: Aphididae) on Christmas tree plantations

Abstract The balsam twig aphid (Mindarus abietinus Koch) (Homoptera: Aphididae) is a major insect pest of balsam and Fraser firs grown for Christmas trees. Few control methods other than chemical insecticides have been evaluated. In this study, we identified insect predators associated with M. abietinus in three fir Christmas tree fields in Michigan. We also conducted laboratory and field studies to assess the effectiveness of augmentative releases of Chrysoperla rufilabris Burmeister (Neuroptera: Chrysopidae) for M. abietinus control. A diverse complex of predators, primarily generalists including syrphids, coccinellids, and lacewings, was observed on infested trees. Predator abundance was generally low early in spring when M. abietinus fundatrices were present, but predators became more common as sexuparae and later aphid stages appeared. In controlled laboratory tests, C. rufilabris were capable of consuming at least 35 M. abietinus per day, but were able to develop on 10 aphids per day. Average adult ...
The Importance of Viable but Nonculturable Bacteria in Biogeochemistry

Biogeochemical cycles are critical parts of life itself—if elements do not cycle, life will grind to a halt, with essential elements being buried. Recycling of the elements allows for their reappearance in the food web to be used again and again, thereby allowing life to replenish itself. A simple example of this is shown in Fig. 1 for the carbon cycle, in which energy flow on Earth is diagrammatically linked to the carbon cycle. In this diagram we see the two major sources of energy on the planet (photic energy and geothermal energy) linked to life directly (through photosynthesis) and indirectly (through conversion of geothermal energy to reduced substrates that are used for lithotrophic metabolism). Both processes lead to the “fixation” or reduction of CO2 to organic carbon—e.g., the conversion of carbon dioxide into biomass. The organic carbon is then recycled to the atmosphere via respiration by carbon-oxidizing bacteria and eukaryotes.
Quantitative Solution Measurement for the Selection of Complexing Agents to Enable Purification by Impurity Complexation

The removal of carboxylic acid impurities from amide targets has been accomplished through crystallization featuring a complexing agent in solution. The interaction between the complexing agents and impurities was examined using isothermal titration calorimetry and the free energy of association obtained. From these data, the mechanism of solution association could be elucidated through the use of infrared spectroscopy, density functional theory calculations, and the judicious variation of solvent and complexing agent. Furthermore, the calculations employed were able to predict the free energy of association between the complexing agents and the impurity. This association energy was found to correlate with the improvement in purification that could be achieved by the addition of these complexing agents. Optimal complexing agent choice in a rationally selected crystallization solvent produced improvements in purity of 96%, greater than could be achieved by successive crystallizations. The applicability of ...
Voices of the Bulge: Untold Stories From Veterans of the Battle of the Bulge

The massive German counteroffensive operation, codenamed Wacht am Rhein (Watch on the Rhine), was launched in the early morning hours of December 16, 1944. Referred to by most Americans as the “Bat...
High Temperature limit for the Growth of Carbon Filaments on Catalytic iron Particles

Carbon filaments of macroscopic length may be produced by heating transition metal catalyst particles in a hydrocarbon-hydrogen mixture. Because the nanometer-sized catalyst particles contain relatively many surface atoms, they melt at a temperature considerably below that of bulk material; this depression of the melting point is difficult both to calcu-late and measure. This work addresses the fundamental question of whether the catalyst particles are in the liquid or solid state during filament growth. We present measurements of the average number of filaments grown per unit area of substrate as a function of temperature which show that the the activity of the catalyst particles drops precipitously above 1030°C and nearly disappears above 1120°C. This compares with the melting point of the Fe-C eutectic of 1154°C. TEM observations show that the average dia-meter of an active catalyst particle is 15±7 nm. Calculations based on the model of Ross and Andres [1] for the melting temperature of small clusters of atoms predict a drop in activity above 1050°C similar to our observa-tions.
TWO CONTINUING EDUCATION MODELS FOR PREPARING TEACHERS TO USE WHOLE LANGUAGE

Summary.-For teachers in two school systems, a longer initial in-service training time with four follow-up meetings throughout the school year was more effective in increasing knowledge and applications of whole language philosophy than a shorter initial training time with follow-up meetings twice a month for two semesters. A shorter initial training with more frequent follow-up meetings resulted in a more favorable attitude toward whole language. What is the most effective way to prepare practicing teachers to learn about new approaches to teaching and to implement these ideas in the classroom? Duke (1986) and Powell (1980) found that follow-up after initial training provides opportunities to try out strategies and share results with others. The goal of this study was to assess an increase in the knowledge of and the effect on teachers' attitudes toward whole language philosophy (Edelsky, Altwerger, & Flores, 1791; Goodman, 1986) resulting from two contrasting models of continuing education. The whole language philosophy (Goodman, 1986) encompasses the following beliefs. Reading, writing, speaking, and listening are taught as an integrated whole rather than as separate subjects. Language is taught through the study of whole real literature rather than contrived lessons based on segmented written selections. Reading is taught through extensive time spent reading real books and intensive study of how writing is done. Strategies and skills are taught as children need them in the context in which they will be immediately applied, rather than as isolated, fragmented skills in decontextuahzed lessons. The processes of reading and writing are closely related and competency in one facilitates the other. Reading is an interaction between the author and the reader, based upon the schemata of both, as supported by the language systems of semantics, syntax, and graphophonics. This study compared an initial two-day training meeting with two afterschool meetings per month throughout the academic year (School A) with a five-day initial period and two four-hour Saturday meetings per semester (School B). The ten participants in School A were teachers (elementary, special education) and a media specialist. School B's six participants were teachers (elementary, high school, and Chapter I). Knowledge tests of matching, multiple choice, truelfalse, and essay
Identifying and Addressing Regulatory and Legal Challenges Encountered by External Auditors in Africa and Asia

Rules, Acts and regulations play an immensely huge role in influencing the quality of audits, as well as facilitating a harmonized system of rules – which in turn, will facilitate better interpretation of accounting standards whilst reducing confusions which could arise as a result of undue significant judgments in the decision making process and the interpretation of standards.This paper identifies, as well as highlights legal and regulatory challenges encountered by external auditors in Asia and Africa. It also identifies links and similarities between challenges encountered by external auditors in these jurisdictions and ways whereby these challenges could be overcome.
Avoiding Pandemic Fears in the Subway and Conquering the Platypus

Metagenomics is increasingly used not just to show patterns of microbial diversity but also as a culture-independent method to detect individual organisms of intense clinical, epidemiological, conservation, forensic, or regulatory interest. A widely reported metagenomic study of the New York subway suggested that the pathogens Yersinia pestis and Bacillus anthracis were part of the "normal subway microbiome." In their article in mSystems, Hsu and collaborators (mSystems 1(3):e00018-16, 2016, http://dx.doi.org/10.1128/mSystems.00018-16) showed that microbial communities on transit surfaces in the Boston subway system are maintained from a metapopulation of human skin commensals and environmental generalists and that reanalysis of the New York subway data with appropriate methods did not detect the pathogens. We note that commonly used software pipelines can produce results that lack prima facie validity (e.g., reporting widespread distribution of notorious endemic species such as the platypus or the presence of pathogens) but that appropriate use of inclusion and exclusion sets can avoid this issue.
Ammonium Additives to Dissolve Lithium Sulfide through Hydrogen Binding for High-Energy Lithium–Sulfur Batteries

In rechargeable Li–S batteries, the uncontrollable passivation of electrodes by highly insulating Li2S limits sulfur utilization, increases polarization, and decreases cycling stability. Dissolving Li2S in organic electrolyte is a facile solution to maintain the active reaction interface between electrolyte and sulfur cathode, and thus address the above issues. Herein, ammonium salts are demonstrated as effective additives to promote the dissolution of Li2S to 1.25 M in DMSO solvent at room temperature. NMR measurements show that the strong hydrogen binding effect of N–H groups plays a critical role in dissolving Li2S by forming complex ligands with S2– anions coupled with the solvent’s solvating surrounding. Ammonium additives in electrolyte can also significantly improve the oxidation kinetics of Li2S, and therefore enable the direct use of Li2S as cathode material in Li–S battery system in the future. This provides a new approach to manage the solubility of lithium sulfides through cation coordination ...
Political Economies of Transition

Tunisia and Syria were among the more preposterous as well as repressive of the region’s authoritarian regimes. Preposterous in Syria as Lisa Wedeen brilliantly illustrated with cartoons and thick descriptions of the cult of Assad (father), inculcating obedience by requiring performances of fealty in which nobody believed.’ Ridiculous in Tunisk for having Ben Ali, a mediocre apparatchik from military intelligence services, not only overthrow the Supreme Warrior Habib Bourguiba but also mimic his personality cult with a narrative that was “peculiar in its naivete.”2 Perhaps, as Kai Hafez has argued, the two regimes were also among the region’s most repressive because each was defending an unpopular secular ideal.3 Whatever the possible similarities, however, this chapter underlines major structural differences between Syria and Tunisia that explain the critical variations not only in their recent political awakenings but also why Egypt, not Syria or Libya, could be Tunisia’s most faithful echo. The big structural difference concerns their respective private sectors and banking systems. Tunisia, like Egypt, had generated substantial, if politically subordinate private sector, from a restructurec socialist economy, whereas Syria, like Libya and Yemen, had consignec theirs, either by design or lack of financial capacity, to the shadows of the informal economy. While the IMF and World Bank had pressured most of these countries to engage in neo-liberal reform, private sector development varied significantly. Tunisian and Egyptian businesses enjoyed considerably more commercial bank financing than the others.