cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurement of handle forces for crimping connectors and cutting cable in the electric power industry

Abstract Overhead and underground line work in the electric power industry is physically very strenuous and can expose workers to musculoskeletal disorders (MSDs), particularly in the upper extremity. Crimping compression connectors—such as sleeve connectors and lugs—and cutting cables are two of the most frequent tasks that line workers perform. Line workers at many utilities in the US crimp connectors and cut cable with long-handled manual tools. However, the actual magnitude of the forces applied to the handles of these tools is not known. The objectives of this laboratory study were to measure the forces applied to the handles of a manual press and a manual cutter in order to connect typical wire gauges and cut common cables, respectively. The handles of the manual press and cutter were attached to the drive cylinder and load cell of an Instrom Material Testing System, and peak forces exerted against the handles were measured. Results showed that the outer die of the manual press required about 50% more handle force than crimping connectors with the inner die location. The peak handle forces required to cut aluminum conductor cable as large as 2 cm diameter exceeded 500 N and were about 200 N greater than the peak forces to compress connectors manually. When the peak force data were compared to strength capabilities reported in the literature, less than 1% of the general population was found to have the maximum strength to manually make one crimp on a common overhead connector. Less than 1% and approximately 50% of the female and male general population, respectively, were found to have the maximum strength to manually cut a cable with a 2 cm diameter conductor. Handle force data from this study provide a biomechanical framework for explaining how the job demands of overhead and underground line workers could possibly cause MSDs. Relevance to industry Electric power utilities can review their work practices and tools in order to determine whether they can reduce the exposure of their workers to risk factors of MSDs, as well as reduce their cost of health care. Manufacturers of crimping and cutting tools can use the experimental approach in this study to measure the external forces required for their respective tools and then set quantitative force benchmarks to improve the design of their tools.
Male pigeons react differentially to altered facial features of female pigeons.

Male pigeons exhibit robust courtship to the head of a female, but not so much to the body. The specific features in the female head which are critical for triggering courtship from males remain unclear. We examined this issue by studying preference behaviour of male pigeons between a pair of photographic images of female conspecifics: a series of normal female faces and a series of digitally altered facial features. Preference was determined by measuring the duration of male courtship 'coo' responses near each of these images. Males preferred intact females compared to those missing the eyes and beak. They also responded less when only the eyes and beak were visible without the head, suggesting that these local features were important, yet more effective when embedded in the context of the head than when they were not. Enlarging or removing the beak had a significant impact on preference, whereas manipulating the eyes had a weaker effect. Finally, males exhibited no preference between normal females and those that had spatially rearranged eyes and beak. These results suggest that pigeons naturally attend to the local features of the head, but not to the spatial configuration, for conspecific recognition.
Limited open reduction and stabilization of sacroiliac fracture-luxations using fluoroscopically assisted placement of a trans-iliosacral rod in five dogs.

Objective— To describe percutaneous fluoroscopically assisted placement of a trans-iliosacral rod to stabilize sacroiliac fracture-luxations after limited open reduction. Study Design— Retrospective clinical case series. Animals— Dogs (n=5) with sacroiliac fracture-luxations. Methods— Medical records and radiographs were reviewed to evaluate implant placement, fracture reduction, pelvic canal diameter ratio, maintenance of reduction, implant stability, assessment of union, and to identify any complications. Owners were contacted to obtain long-term assessment of limb function. Results— Dogs weighed between 6 and 31 kg. Trans-iliosacral rods were placed correctly traversing the sacral body. Mean (±SD) percent reduction of the sacroiliac joint was 92.9±6.6%. Pelvic canal diameter ratio did not differ significantly between time periods. With the exception of 1 dog, which died in the early postoperative period, all sacroiliac fracture-luxations healed without appreciable complications. Three dogs were sound and 1 dog had a subtle lameness at final physical and radiographic examination (mean±SD: 217±205 days). Owners assessed their dog's limb function (mean±SD: 355±205 days) as good or excellent. Conclusions— Trans-iliosacral rods can be accurately placed using intraoperative fluoroscopy after limited open reduction of sacroiliac fracture-luxations. Trans-iliosacral rods provided bilateral secure fixation, allowed early weight-bearing and dogs consistently had good long-term clinical results. Clinical Relevance— Trans-iliosacral rods are suitable implants for the stabilization of sacroiliac fracture-luxations, particularly in dogs with bilateral fracture-luxations and/or concurrent musculoskeletal injuries.
Recontamination does not help to search a graph

This paper is concerned with a game on graphs called graph searching. The object of this game is to clear all edges of a contaminated graph. Clearing is achieved by moving searchers, a kind of token, along the edges of the graph according to clearing rules. Certain search strategies cause edges that have been cleared to become contaminated again. Megiddo et al. [9] conjectured that every graph can be searched using a minimum number of searchers without this recontamination occurring, that is, without clearing any edge twice. In this paper, this conjecture is proved. This places the graph-searching problem in NP, completing the proof by Megiddo et al. that the graph-searching problem is NP-complete. Furthermore, by eliminating the need to consider recontamination, this result simplifies the analysis of searcher requirements with respect to other properties of graphs.
Profiling, mimicking and masking the flavor of a selected rodenticide.

In Experiment 1, rats drank strychnine solution followed by an injection of LiCl. Generalization of learned strychnine avoidance to 4 non-toxic flavors was the nassessed. Additional conditioning and generalization trials followed until 24 flavors had been presented. In Experiment 2, rats were conditioned to avoid individual flavors, or flavor mixtures concocted on the basis of avoidance generalization observed in Experiment 1. Tests followed for generalization of learned avoidance from the simple flavors to the mixtures, from the mixtures to the simple flavors, and from either to strychnine. In Experiment 3, two concentrations of NaCl were mixed with strychnine or one of the flavors (SOA) used in the previous experiments. These stimuli, as well as SOA alone, strychnine alone, and each of the NaCl concentrations, were presented to rats during conditioning. Generalization followed, as in the previous experiments. In Experiment 1, strychnine avoidance generalized to ‘bitter’ flavors (ps<0.01). In Experiment 2, avoidance of flavor mixtures generalized more strongly to strychnine than did learned avoidance of simple flavors (ps<0.01). In Experiment 3, NaCl masked or otherwise suppressed the ‘bitter’ flavor of strychnine or SOA insofar as no groups conditioned with a ‘bitter’-salt mixture generalized avoidance to ‘bitter’ alone (ps<0.01). Rats are therefore capable of recognizing the flavor components of strychnine. Moreover, when these components are mixed in proportion to the degree of generalized avoidance, a mimic (either in terms of flavor characteristics or perceived intensity) of strychnine is obtained. Avoidance learning appears useful in the development of rodenticide baits and pre-bait formulations.
The role of dopaminergic mechanisms in naloxone-induced inhibition of apomorphine-induced stereotyped behavior

Abstract Although a number of reports has recently suggested naloxone (NX) might affect dopamine (DA) agonist-elicited behavior, the effect of NX on apomorphine-induced sterotyped behavior (AISB) has not yet been systematically investigated. Doses of NX varying from 0.20 to 20.0 mg/kg were administered prior to the injection of apomorphine (0.5 mg/kg), a directly acting DA agonist, and the effect of NX on AISB was subsequently assessed. A sequential doubling of the dose of NX administered from 0.20 to 3.20 mg/kg generated a partial antagonist curve for AISB which fell in a linear manner from 0.20 to 0.40 mg/kg NX and thereafter became essentially asymptotic with 20 mg/kg producing the same effect on AISB as 0.4 mg/kg. Pretreatment with 0.4 mg/kg NX produced a sigmoidal inhibition of the stereotypy induced by successive doses of apomorphine (0.10–0.25 mg/kg). In a subsequent study, a low dose of NX (0.05 mg/kg) was combined with the specific DA receptor antagonist haloperidol (0.01 or 0.05 mg/kg) to determine if extremely low doses of the two antagonists could act synergistically. This was subsequently confirmed. Moreover, while a low dose of haloperidol (0.20 mg/kg) completely abolished AISB, 100 × this dose of NX (20.0 mg/kg) was only partially effective in this respect, indicating that NX, unlike haloperidol, exerts a partial antagonist effect relative to AISB. Furthermore, the marked synergistic effect of the very low doses of NX and haloperidol on blocking AISB was greater than their additive postsynaptic effects, suggesting that the effect of NX on AISB may in part be presynaptic.
Suppressor mutations (rin) that specifically suppress the recA+ dependence of stable DNA replication in Escherichia coli K-12

The sdrA102 mutation confers upon cells the ability to replicate DNA in the absence of protein synthesis. This mutation was combined with the recA200 mutation, which renders the recA protein thermolabile, and had little effect on normal replication. However, the sdrA102 recA200 double mutant exhibited temperature-sensitive stable DNA replication: it replicated DNA continuously in the presence of chloramphenicol at 30°C, whereas at 42°C DNA replication ceased after the DNA content increased only 40–45%. Suppressor mutants (rin; recA-independent) capable of stable DNA replication at 42°C were isolated from the double mutant. The suppressor mutant retained all other recA− characteristics, i.e., deficient general recombination, severe UV-sensitivity, and incapability of prophage induction in lysogens. This indicates that the rin mutation specifically suppresses the recA+ dependency of stable DNA replication. It is suggested that the recA+ protein stabilizes a specific structure, similar to an intermediate in recombination, which may function in the initiation of stable DNA replication.
Bacterial luciferase activity does not require a disulfide-dithiol conversion

Abstract Recent reports revive an earlier hypothesis by specifically proposing that the formation of the first bacterial luciferase intermediate involves the complete oxidation of reduced riboflavin 5′-phosphate and the reduction of an enzyme disulfide to dithiol. Optical measurements show that the flavin stays reduced after binding to luciferase under anaerobic conditions. Diagonal paper electrophoresis also demonstrates that native luciferase does not contain any disulfide bonds. Furthermore, the recovery of active luciferase from unfolded subunits requires the presence of high concentrations of dithiothreitol, a disulfide-reducing reagent.
Uncertainty relation for resolution in space, spatial frequency, and orientation optimized by two-dimensional visual cortical filters.

Two-dimensional spatial linear filters are constrained by general uncertainty relations that limit their attainable information resolution for orientation, spatial frequency, and two-dimensional (2D) spatial position. The theoretical lower limit for the joint entropy, or uncertainty, of these variables is achieved by an optimal 2D filter family whose spatial weighting functions are generated by exponentiated bivariate second-order polynomials with complex coefficients, the elliptic generalization of the one-dimensional elementary functions proposed in Gabor’s famous theory of communication [ J. Inst. Electr. Eng.93, 429 ( 1946)]. The set includes filters with various orientation bandwidths, spatial-frequency bandwidths, and spatial dimensions, favoring the extraction of various kinds of information from an image. Each such filter occupies an irreducible quantal volume (corresponding to an independent datum) in a four-dimensional information hyperspace whose axes are interpretable as 2D visual space, orientation, and spatial frequency, and thus such a filter set could subserve an optimally efficient sampling of these variables. Evidence is presented that the 2D receptive-field profiles of simple cells in mammalian visual cortex are well described by members of this optimal 2D filter family, and thus such visual neurons could be said to optimize the general uncertainty relations for joint 2D-spatial–2D-spectral information resolution. The variety of their receptive-field dimensions and orientation and spatial-frequency bandwidths, and the correlations among these, reveal several underlying constraints, particularly in width/length aspect ratio and principal axis organization, suggesting a polar division of labor in occupying the quantal volumes of information hyperspace. Such an ensemble of 2D neural receptive fields in visual cortex could locally embed coarse polar mappings of the orientation–frequency plane piecewise within the global retinotopic mapping of visual space, thus efficiently representing 2D spatial visual information by localized 2D spectral signatures.
The Magnesium Load Test: III. Correlation of Clinical and Laboratory Data in Infants from One to Six Months of Age

A study of 64 infants from one to six months of age was made using the 32-hour parenteral magnesium load test. Most of the infants were studied for neuromuscular hyperirritability or other signs compatible with magnesium deficiency; some with unrelated problems served as controls.Magnesium retention below 40 per cent was found in 26 infants who presented with minor signs or signs that were otherwise explained, as by infection. Twelve who retained 72 per cent of the load were normal or small at birth, amply fed on demand, and grew at accelerated rates, increasing from the 50th to the 88th mean percentile by ten weeks, when they were "fat, hungry, jumpy babies," exemplifying the Mg deficiency syndrome of growth. Seven infants of 8.2 ± 1 weeks had had one or more sudden, transient episodes that included: apnea, gasping, tonic or tonic-clonic fits, and flaccidity, often with pallor, cyanosis, eye signs, sweating, or tearing. Despite preload Mg in two, the group retained 88 per cent of the load. Mg appeared to...
The use of intravenous γ-globulin in idiopathic thrombocytopenic purpura

In 1981, Imbach et al. (Lancet, 1, 1228-1231) reported that infusion of intravenous immunoglobulin (IVIG) would substantially elevate platelet counts in children with acute or chronic idiopathic thrombocytopenic purpura (ITP). Subsequent studies confirmed these findings and extended the effect to adults and to newborns with passive immune thrombocytopenia. Studies in children with acute ITP demonstrated that administration of IVIG was the fastest way to increase a patient's platelet count, and that this agent could be given at doses as high as 1 g/kg/day so that the course of therapy and response to treatment would be more rapid. Reports of effective treatment of patients with autoimmune neutropenia and autoimmune hemolytic anemia by IVIG broadened the scope of its usefulness. In addition, several studies in children and adults with chronic ITP suggested that repeated infusions were a safe and effective way to maintain an adequate platelet count in such patients, and might also gradually lead to lasting improvement. These studies and Imbach's controlled trial in children with acute ITP suggested that IVIG therapy might provide a curative effect in addition to the acute effect. To combine all of these clinical effects with a multitude of in vitro observations to explain the mechanism of action of IVIG is complicated. Fehr et al. (N. Engl. J. Med. 306, 1254-1258, 1982) showed that Fc receptor blockade occurs following administration of IVIG. This effect is clearly demonstrated in vivo by the delayed removal from the vascular space of antibody-coated red blood cells following infusion of IVIG. In addition, many less well-defined effects occur in relation to immunoglobulin production, induction of suppressor cells, antiplatelet antibody levels, and bone marrow platelet production. Studies continue to try to define which effects actually underlie the clinical effects seen, and which are merely test-tube phenomena.
Complications: Rare and unusual

W E WERE, HARD PRESSED in titling this article Complications: Rare and Unusual." The tautologist in our midst stated the redundancy, but then consider the whole of the F word! 1 To paraphrase Sykes 2 an anesthesiologist 's complications tend to be permanent and f ina l -however rare and unusua l in contrast to those of the surgeon, which usually can be rectified by a more skillful surgeon at a later date. 2 Notwithstanding, we have used a somewhat arbitrary anatomic grouping for such complications, which includes those we ran across (or conversely), from head to toe. More specifically, for anatomic sites, we shall consider cognitive psychomotor impairment (brain), other complications therein (such as headache and hearing), and airway, the eye, and taste, and smell. Edema, embolism, and nerve injuries have been allotted sections, as have diseases and drugs (including sensitivity, toxicity, and transfusions), which last two groups cover a multiplicity of anatomic sites of the human body. Because of space limitations, we only discuss catheters as part of our newfound friendly monitoring equipment.
Sources of Economic News and Economic Expectations

This article considers the process by which local economic news coverage influences individual evaluations of the economy. We improve on prior research by capturing a wider range of news sources (including national network news, national newspapers, local television news, and local newspapers) and connecting the effects of this coverage on individual level attitudes. We find that current personal financial evaluations, personal financial expectations, and short-term (12-month) expectations for the U.S. economy are related to national network coverage. Local television coverage of the economy is related to personal financial evaluations but not short-term economic expectations and local print news is important in structuring expectations of future business conditions. Overall, the findings illustrate important differences in economic coverage across media outlets and the effects of these differences on economic expectations. Exposure to different sources of economic information have significantly different...
Chronic demands and responsivity to challenge.

Certain kinds of arousal in response to challenge situations reflect conditioning that makes one adaptive to task demands. A growing literature implicates chronic stress as a factor degenerating this conditioning. This study investigated the relation between objective occupational demands to which workers were classified for at least 2 years and various indicators of adaptive responsivity to challenge situations. There were consistently significant and negative relations between the occupational exposures and cardiovascular and skin temperature responsivity to the acute challenges administered in the laboratory, the corresponding speed of recovery to baseline after removal of the challenge stimulus, and peripheral catecholamine changes during a work shift. Recent research using humans and animals as subjects indicates that chronic stress exposures may condition sympathetic nervous system arousal responses to demands in general. Specifically, there is evidence that chronic exposure to stressful conditions without corresponding control over coping resources may lead to a diminished ability to cope physiologically with challenging demands (see the review by Dienstbier, 1989). There are important implications if workers chronically exposed to occupational stress exhibit a lesser ability to respond adaptively to challenge situations. First, degeneration in responsivity can impede the worker's ability to perform effectively on challenging tasks, thereby reducing productivity and increasing workplace hazards. In addition, it has been suggested that diminished responsivity to challenge reduces the individual's capacity to cope actively with stressful demands (see Dienstbier, 1989). The degree of active coping in response to work-related stress is believed to determine whether the exposures will result in ill health (Karasek, Russell, & Theorell, 1982; Karasek et al., 1988). Such processes suggest an interactionist model wherein work environment exposures not only cause ill health, but also diminish adaptive physiological responses. Over time, stress exposures may become more toxic to individuals as their capacities for adaptation are reduced. Next, we review research suggesting that some forms of arousal are necessary for adaptation and that chronic stress can degenerate their activation in response to task challenges. We then present
Mitotic frequency determinations and microphotometric Feulgen dye measurements in root tips.

Treating a Feulgen stained (10 min. acetic-alcohol fixation, 8 min. hydrolysis) onion root tip with 5% aqueous pectinase for 6 hours causes it to disintegrate on shaking in 1 ml. water into a suspension of stained cells, either individual or in small groups. Vicia faba and pea root tips require 15 minutes hydrolysis and 12 hours pectinase treatment. Absence of cell destruction allows absolute cell-number determination by Brown and Rickless' counting chamber technic. By centrif uging the cells down, resuspending them in 2 drops of a Karo syrup-phosphate buffer mixture (2 parts Karo to 1 part 0.5M, pH7 buffer) and mounting a small drop of the now concentrated suspension, a semipermanent slide containing a concentration of well-spread, randomized cells suitable for rapid mitotic frequency determination is obtained. Scoring about 1,000 cells as to nuclear stage gives a representative, workable statistical sample and takes only 20–30 minutes if interphases are recorded on a mechanical tally. Permanent slides c...
Interventional Approaches to Acute Venous Thromboembolism

During the last decade, advances in minimally invasive technologies have spurred a renaissance in the aggressive treatment of venous thromboembolism (VTE) using percutaneous techniques. In this article, we outline the relative risks and benefits of endovascular VTE therapies, highlight clinical situations in which the benefits of endovascular treatment are likely to outweigh its risks, and provide an update regarding the specific new modalities that may be applied to VTE. Pharmacomechanical thrombolysis represents the most promising currently available method to treat VTE. However, pending demonstration that it actually improves VTE outcomes in randomized trials with long-term follow-up, a highly individualized approach to patient selection is recommended. At present, highly compromised patients with pulmonary emboli (PE) in whom systemic thrombolytic therapy has failed or is contraindicated are reasonable candidates for catheter-based PE interventions. Adjunctive pharmacomechanical catheter-directed deep venous thrombosis (DVT) thrombolysis is best indicated for the first-line treatment of patients with phlegmasia cerulea dolens, acute inferior vena cava (IVC) occlusion, and acute iliofemoral DVT after careful clinical assessment and a balanced discussion with the patient. It is hoped that multidisciplinary clinical trials with involvement by both interventionalists and pulmonary physicians will validate these techniques in the near future.
Attentional resource allocation during a cued saccade task

Abstract Attentional selection of sensory information and motor output is critical for successful interaction with one's surroundings. However, organization of attentional processes involved in selection of salient visual information, decision making, and movement planning has not yet been fully elucidated. We hypothesized that attentional processes involved in these tasks can function independently and draw from separate resources. If true, challenging the capacity limit of one attentional process would not affect performance of others. Healthy participants performed a cued saccade task in which target cues were embedded in a central stream of letters in a Rapid Serial Visual Presentation (RSVP). Participants performed saccades as quickly and as accurately as possible to a peripheral target location based on cue presentation within the central letter stream. To challenge visual attention, we parametrically varied the duration at which each letter of the RSVP was presented (50–200 ms). In a separate experiment we challenged motor attention by increasing the number of possible saccade trajectories (1–6 peripheral targets). As expected, increasing attentional load in one domain of the task negatively affected performance in that domain, while performance in other domains was unaffected. We interpret our results as support for the independent allocation of attentional resources, at least in the early stages of processing, required across components of a cued saccade task. Deciphering the contributions of attention during visuomotor tasks is a critical step to understanding how humans process information necessary to successfully interact with the environment.
Unconscious gaps in Jackendoff 's "How language helps us think"?

Jackendoff comes to some appealing overall conclusions, but several of his assumptions and arguments are questionable. The present commentary points out the following problems: oversimplifications in the translation-based argument for the independence of language and thought; a lack of consideration of the possibility of unconscious use of internalized natural languages; insufficient consideration of possible characteristics of languages of thought (as opposed to internalized natural languages); neglect of the possibility of thinking in example-oriented and metaphorical ways; unfair bias in contrasting visual to linguistic imagery; neglect of other types of imagery; and neglect of the possibility of unconscious attentional processes.
A 36-Year-Old Man With Seizures and Multiple Cystic Pulmonary Nodules

A 36-year-old Hispanic man presented to an outside institution with new onset simple partial motor seizures, which were characterized by clonic twitching and tonic activation of the left lower face, with gradual deviation of the head to the left. The seizures would develop either spontaneously or with left facial stimulation and were often preceded by perioral tingling. They would last 30 to 60 s and occur as frequently as every 15 to 30 min. Because of difficulty controlling his seizures with antiepileptic therapy, he was referred to our institution. He complained of fatigue and dizziness and noted dyspnea for the previous 2 months. He had no prior health problems and took no medications. He was a one pack/d smoker, and he denied ethanol and illicit drug use. Physical Examination Vital signs revealed BP of 115/71 mm Hg, pulse 68 beats/min, respiratory rate 16 breaths/min, and temperature 36.5°C. Physical examination noted a man in mild acute distress. Cranial nerves II to XII were grossly intact; left cranial nerve V testing was avoided because of concern about eliciting a seizure. Strength and deep tendon reflexes were normal. Lungs were clear to auscultation, heart was regular without murmurs, and abdomen was benign without hepatosplenomegaly. No lymphadenopathy was appreciated. Laboratory Findings Laboratory tests revealed a leukocyte count of 8.5×109 (normal, 3.5-10.5×109). Cerebrospinal fluid analysis showed 89 total nucleated cells (normal, 0-5) with 35% neutrophils and 39% lymphocytes, RBC count of 152, glucose level of 57 mg/dL (corresponding serum level of 90), and protein level of 42 mg/dL (normal, 0-35 mg/dL). Vancomycin, ceftriaxone, and acyclovir were initiated empirically for possible infectious meningitis, although subsequent extensive investigations for infection were all negative. MRI of the brain showed increased T2 signal in the bilateral frontal and parietal sulci, consistent with leptomeningeal inflammation. EEG showed focal rhythmic spike discharges in the right frontocentral region that became obscured by rhythmic clonic muscle artifact bilaterally. Over several days, seizures were refractory to escalating antiepileptic drugs. The seizures began to extend to the left arm and leg. The patient was intubated for airway protection. Out of concern for a systemic cause of seizures, further imaging was obtained. CT scanning of the chest showed multiple cystic pulmonary nodules, primarily in the upper lobes (Fig 1). CT scanning of the pelvis and abdomen was unrevealing. The patient subsequently underwent video-assisted thorascopic surgery. A histopathology slide is shown in Figure 2. Further, immunochemical staining was positive for S100 and CD1A. Figure 1. CT scan of the thorax. Multiple cavitating pulmonary nodules. Figure 2. Histology of lung biopsy. Histiocytes and eosinophils (hematoxylin and eosin, original magnification ×400). What is the diagnosis? Diagnosis: Pulmonary Langerhans cell histiocytosis with CNS manifestations
Cardiopulmonary Support Mitigates the Effects of Experimental Myocardial Ischemia

The effectiveness of cardiopulmonary support (CPS) as a rescue method following failed angioplasty is unknown. The proximal left anterior descending (LAD) was occluded for 20 min in 21 dogs. Group 1 animals (n=15) were given CPS and group 2 animals (n=6) served as controls. During coronary occlusion, animals receiving CPS had increased mean arterial pressure (71 ± 12 vs 58 ± 7 mm Hg), decreased left atrial pressure (3 ± 3 vs 12 ± 3 mm Hg), increased ischemic area blood flow (0.20 ± 0.16 vs 0.02 ± 0.04 mL/min/g) and myocardial oxygen consumption (0.014 ± 0.008 vs 0.003 ± 0.006 mL O2/min/g), decreased remote area myocardial oxygen consumption (0.026 ± 0.010 vs 0.091 ± 0.047 mL 02/min/g), and an improved myocardial oxygen consumption index (0.60 ± 0.33 vs 0.02 ± 0.03) when compared with controls (p
Michellamine alkaloids inhibit protein kinase C.

Michellamines A, B, and C have shown antiviral activity against HIV-1 and HIV-2 in cell culture. They act in a complex manner by at least two reported antiviral mechanisms, inhibition of HIV reverse transcriptase and inhibition of HIV-induced cellular fusion. On the basis of their structural similarity to other protein kinase C (PKC) inhibitors, we have investigated another possible mechanism-inhibition of PKC. The michellamines were found to inhibit rat brain PKC with IC50 values in the 15-35 microM range. Michellamine B was a noncompetitive PKC inhibitor with respect to ATP with a Ki value of 4-6 microM, whereas mixed-type inhibition was observed when the peptide concentration was varied. Michellamine B inhibited the kinase domain of PKC similarly. These results indicate that the michellamines bind to the PKC kinase domain and not its regulatory domain. Molecular modeling showed that all three michellamines can bind in the active site cleft of the PKC kinase domain, to block both the ATP and the peptide substrate subsites.
Connection to parents and healthy separation during adolescence: A longitudinal perspective

The purpose of our study was to investigate how connection between parents and children influences the child's healthy separation during adolescence. We analyzed 3 waves of panel data from a study (Flourishing Families Project) of 500 families with children who were 10-13 years old at Time 1. This study includes information from the perspective of the child and his/her mother over a 4 year period for two-parent families and mother-headed households. Findings supported our hypothesis that a mutual sense of connection between mothers and adolescents supported the adolescent's healthy separation over time, with differences due to sex of the child, ethnicity and income. Pubertal maturation was negatively associated with the sense of connection between adolescents and mothers in our sample of young adolescents. We discuss these findings in relation to previous literature.
The influence of the microenvironment on the malignant phenotype

Normal tissue homeostasis is maintained by dynamic interactions between epithelial cells and their microenvironment. As tissue becomes cancerous, there are reciprocal interactions between neoplastic cells, adjacent normal cells such as stroma and endothelium, and their microenvironments. The current dominant paradigm wherein multiple genetic lesions provide both the impetus for, and the Achilles heel of, cancer might be inadequate to understand cancer as a disease process. In the following brief review, we will use selected examples to illustrate the influence of the microenvironment in the evolution of the malignant phenotype. We will also discuss recent studies that suggest novel therapeutic interventions might be derived from focusing on microenvironment and tumor cells interactions.
Molecular substructure of fibrinogen.

Abstract Recent studies have provided much new information on the structure of the plasma protein fibrinogen. N-terminal analyses of fibrinogen and fibrin (Blomback and Yamashina, 1958) have suggested that the native molecule is a dimer consisting of three pairs of polypeptide chains. This idea is supported by studies on the conversion of fibrinogen to fibrin by thrombin which have shown that two A peptides and two B peptides are released per fibrinogen molecule ( Blomback, 1958 ; Gladner et al. , 1959 ). This report described two methods for the dissociation of fibrinogen and a partial characterization of the products by physical means. The results support the model given above and suggest that the polypeptide chains of fibrinogen are linked by disulfide bridges.
Removal of carbon dioxide in closed loop off-gas treatment systems

Abstract A combustor with a closed loop off‐gas recirculation system has been constructed to demonstrate a gas treatment and purification system that can be installed on hazardous and mixed‐waste incineration and vitrification equipment to virtually eliminate the potential for release of hazardous or radioactive materials to the environment. In initial tests, a 250,000 BTU/h (75 kW thermal) combustor was operated in an open loop to demonstrate the removal of combustion product CO2 in a fluidized bed of CaO (lime), and particulates were removed with hot gas candle filters. An absorbent solution treatment (AST) process is now being developed for removal of CO2 from a side loop. High CO2 concentrations can be maintained in the recirculating gases, and this improves the performance of commercially available processes used to purify gases and produce CO2. Incineration systems with closed loop off‐gas treatment can have a high throughput and accommodate more hazardous and more radioactive waste streams than wha...
Contrast-to-noise ratios of liver lesions using subtraction imaging on multiphase 64-detector row CT

Aim To measure contrast-to-noise ratios of liver lesions on conventional enhanced and digitally subtracted multidetector row computed tomography (CT) images. Materials/methods This study was approved by our hospital internal review board (IRB) and all collected data were evaluated in a Health Insurance Portability and Accountability Act (HIPAA)-compliant manner. Subtracted datasets, using pixel-by-pixel subtraction of the post-contrast images from the pre-contrast images, were created from the 64 detector-row CT of patients undergoing three-phase examination of the liver (unenhanced, arterial phase, and portal venous phase). Regions of interest were used to calculate the contrast-to-noise ratios between the lesions and the background liver parenchyma on both the post-contrast and subtracted datasets using the following formula: (Lesion mean (HU) – Liver mean (HU))/standard deviation of mean outside patient (HU). These ratios were compared using a mixed linear statistical model. Results Contrast-to-noise ratios were calculated for 64 lesions in 50 consecutive patients. Of the 64 lesions, 42 were hypervascular and 22 were hypovascular. Subtracted datasets yielded statistically significant higher contrast-to-noise ratios of hypervascular lesions compared to normal liver parenchyma ( p p = 0.16). Conclusion Post-processed subtraction CT images generate increased contrast-to-noise ratios for hypervascular liver lesions. As this technique is easy to perform and does not involve additional radiation exposure, it should be considered when evaluating for suspected hypervascular lesions.
On the Dynamics of Predator–Prey Models with the Beddington–DeAngelis Functional Response☆

Abstract The dynamics of predator–prey models with the Beddington–DeAngelis functional response are analyzed, primarily from the viewpoint of permanence (uniform persistence). The Beddington–DeAngelis functional response is similar to the Holling type 2 functional response but contains an extra term describing mutual interference by predators. Both spatially homogeneous models based on ordinary differential equations and reaction–diffusion models are considered. Criteria for permanence and for predator extinction are derived. For systems without diffusion or with no-flux boundary conditions, criteria are derived for the existence of a globally stable coexistence equilibrium or, alternatively, for the existence of periodic orbits.
How many creatine kinase "isoenzymes" are there and what is their clinical significance?

Recently, there has been a growing awareness of creatine kinase (CK) electrophoretic bands which exhibit mobilities different from those of CK-MM, MB and BB. These electrophoretic bands have been designated as “variant”, “atypical”, or “macro-CK” isoenzymes, and their mobilities can be cathodic or anodic [l-5]. Anodic variants have been found between the origin and CK-MM and also between CK-MM and CK-MB bands. Their formation has been variously attributed to polymeric aggregation of CK monomers, or to complexing of CK isoenzymes with immunoglobulins, lipids, lipoproteins, or unknown serum components. Cathodic variant bands, on the other hand, have generally been assumed to be of mitochondrial origin [6,7]. These variant isoenzymes are of both practical and clinical interest to laboratory scientists and physicians. A number of reports have already appeared dealing with their origin and possible clinical significance. In this brief review, we propose to examine critically the generally adopted procedures for characterization of variant CK isoenzymes and some of the assumptions underlying their clinical interpretation. Variant CK isoenzymes are commonly detected by electrophoresis and initially defined as such by their unusual electrophoretic mobilities compared to those of CK-MM, MB and BB isoenzymes. Immunochemical techniques have been used to characterize further the components of the variant bandsimmunoinhibition assays using anti-CK-M and anti-CK-B antisera to determine if the variant isoenzymes have CK-M or CK-B immunoreactivity [2,3,5] and immunoprecipitation techniques with antisera of different specificities (e.g., antiserum against IgG) to identify the unknown complexing substance [2,3,8]. In addition, tests based on physical properties, e.g., stability to heat treatment and urea dissociation, molecular size by gel permeation chromatography, are frequently used. Although more sophisticated techniques, e.g., ion exchange chromatography [ 1,9], isoelectric focusing [ 10,111, and gel filtration chromatography [ 12,131 can also detect variant isoenzymes, those techniques are not used routinely in clinical laboratories, and have not been responsible for the initial detection of most of the reported cases of variant CK isoenzymes. For this reason, we chose to restrict our discussion to the
A non-radioactive fluorescent method for measuring protein kinase C activity.

Abstract The purpose of this study is to report the development of a non-radioactive fluorescent peptide assay for measuring protein kinase C activity (PKC). The assay is based on a glycogen synthase derived fluorescent peptide that is phosphorylated by PKC. Phosphorylation causes the peptide to migrate toward the anode while the non-phosphorylated peptide migrates toward the cathode during agarose gel electrophoresis. Quantitation of PKC activity can be accomplished by excision of the appropriate bands and measuring their relative fluorescence. Using this assay, PKC activity was measured in whole cell homogenates from cultured renal mesangial cells. The enzyme(s)-substrate system followed Michaelis-Menten kinetics under limited conditions and, therefore, Lineweaver-Burk plots were used to obtain Michaelis constant and maximum velocity values. An apparent K M value of 40 μM was obtained for the fluorescent peptide substrate with a control V max value of 300 pmol/min. Addition of phorbol 12-myristate 13-acetate increased V max to 380 pmol/min.
Critical nucleus size for disease-related polyglutamine aggregation is repeat-length dependent

The formation of aggregates of polyglutamine (polyQ) sequences is initiated by nucleated growth polymerization. New results show that over a short repeat length range from Q26 to Q23 the size of the nucleus changes from monomeric to dimeric to tetrameric, suggesting aggregation nucleus size has a role in pathogenicity.
Time course of early histopathological lung changes in an ovine model of acute lung injury and pulmonary infection

ABSTRACTLarge animal models are valuable tools in biological and medical lung research. Despite the existence of established large animal models, the scientific progress requires more detailed description and expansion of established methods. Previously, we established an ovine model of acute lung injury and subsequent bacterial instillation into the lungs. The current study was designed to assess the time course of early lung histopathological alterations in a large animal model. Injury was induced by smoke inhalation and instillation of live Pseudomonas aeruginosa into the lungs. After 4, 8, 12, 18, and 24 hours, respectively, lung tissue was harvested and histopathological changes were evaluated (n = 4 each). Additional four sheep received no injury and only lung tissue was taken. In injured animals, bronchial obstruction score increased over time and was significantly elevated from 12 to 24 hours (P < .05 versus no injury). Inflammation score was significantly increased at 12 and 18 hours (P < .05 ver...
Multiple blood pressure loci with opposing blood pressure effects on rat chromosome 1 in a homologous region linked to hypertension on human chromosome 15

Genetic dissection of blood pressure (BP) quantitative trait loci (QTLs) in rats has facilitated the fine-mapping of regions linked to the inheritance of hypertension. The goal of the current study was to further fine-map one such genomic region on rat chromosome 1 (BPQTL1b1), the homologous region of which on human chromosome 15 harbors BP QTLs, as reported by four independent studies. Of the six substrains constructed and studied, the systolic BP of two of the congenic strains were significantly lower by 36 and 27 mm Hg than that of the salt-sensitive (S) rat (P < 0.0001, P = 0.0003, respectively). The congenic segments of these two strains overlapped between 135.12 and 138.78 Mb and contained eight genes and two predicted miRNAs. None of the annotations had variants within expressed sequences. These data taken together with the previous localization resolved QTL1b1 with a 70% improvement from the original 7.39 Mb to the current 2.247 Mb interval. Furthermore, the systolic BP of one of the congenic substrains was significantly higher by 20 mm Hg (P < 0.0001) than the BP of the S rat. The limits of this newly identified QTL with a BP increasing effect (QTL1b1a) were between 134.12 and 135.76 Mb, spanning 1.64 Mb, containing two protein-coding genes, Mctp2 and Rgma, and a predicted miRNA. There were four synonymous variants within Mctp2. These data provide evidence for two independent BP QTLs with opposing BP effects within the previously identified BP QTL1b1 region. Additionally, these findings illustrate the complexity underlying the genetic mechanisms of BP regulation, wherein inherited elements beyond protein-coding sequences or known regulatory regions could be operational.
Replicating the NEO-PI-R factor structure in African-American older adults

Abstract Personality structure of African-American older adults using the Baltimore Study of Black Aging (BSBA; N = 234; Age range 49–88, M = 67; 72% women; Education M = 11 years) was compared with the census-matched normative NEO-PI-R factor structure. Principal components with Procrustes rotation was used to calculate factor, facet, and total congruence coefficients. Significant factor congruence coefficients at a 99% probability level or beyond were found, and only three facet-level congruence coefficients did not reach significance. With the exception of cross-loadings on a few facets, most primary and secondary loadings generally replicated the normative structure providing evidence that there are little differences among the African-American older adults and the largely European American normative structure.
Structural Design and Thermal Properties of Polymers

Abstract Aerospace technology has established the demand for thermally stable polymers which retain useful properties at high temperatures. The reliability of a re-entry shield is directly dependent on the performance of the polymers used as ablators. Polymeric ablation materials are sacrificial and are classified as subliming and charring ablators. Subliming polymeric ablators function by (a) depolymerization-vaporization, (b) pyrolysis-evaporation, and (c) melting-vaporization. Polymers which depolymerize quantitatively and reversibly are ideal subliming ablators. Under hyperthermal conditions, charring polymeric ablators must generate a large amount of char residue which will act as a binder at high temperatures for the reinforcements embedded in the char layer. Generally, the higher the thermal stability of the polymer, the higher the yield of char. The maximum thermal stability in polymers is usually obtained when: (a) thermally unreactive ring structures constitute a major portion of the polymer, (b...
Facilitation of immunoreactive corticotropin-releasing factor secretion into the hypophysial-portal circulation after activation of catecholaminergic pathways or central norepinephrine injection.

The functional role of central catecholamines in regulation of ACTH secretion remains controversial. In the present report, the nature of catecholaminergic influences was directly assessed by measurement of hypophysial-portal plasma immunoreactive CRF (irCRF) levels after activation of endogenous aminergic pathways by electrical stimulation or administration of norepineprhine (NE). Electrical stimulation of the ventral noradrenergic ascending bundle, a fiber system primarily carrying catecholaminergic fibers arising from brainstem regions, resulted in a 2.9-fold elevation of portal irCRF levels. Pretreatment with the αl-adrenergic receptor antagonist coryanthine, but not the β-adrenergic antagonist propranolol, blocked the facilitatory effect of electrical stimulation and reduced prestimulation irCRF levels by 34.7 ± 4.2% (P < 0.05). Intracerebroventricular administration of 0.1-5.0 nmol NE resulted in a dose-dependent facilitation of portal plasma irCRF levels which could be blocked by pretreatment with ...