cssi/SciSciGPT-SciSciNet huggingface dataset:
A vertebrate cytokine primer for eco-immunologists

Summary The field of eco-immunology seeks to address the causes and consequences of natural variation in immune responses. Recently, the development of more immunological resources for nonmodel systems along with the growing availability of genomic data has made it feasible to explore more complex immunological differences in nonmodel systems. Cytokines are small molecular weight proteins that are the major signalling molecules of the immune system. Studies in mice and humans have demonstrated the importance of tightly regulated cytokine signalling, and thus, cytokines may play a major, unexplored role in explaining natural variation in immune responses. In this review, we highlight cytokines that are likely to be important for eco-immunology studies and what is currently known about their presence or absence in the major vertebrate groups. We also explore what types of questions an eco-immunologist might ask involving cytokines and discuss potential ways to measure cytokines in nonmodel systems. Inclusion of cytokines in eco-immunology will advance the field as it will help us to better understand mechanisms behind both natural variation in immune responses and how different taxa respond to immune challenges.
Disruption of genes encoding predicted inner arm dynein heavy chains causes motility phenotypes in Tetrahymena.

The multi-dynein hypothesis [Asai, 1995: Cell Motil Cytoskeleton 32:129–132] states: (1) there are many different dynein HC isoforms; (2) each isoform is encoded by a different gene; (3) different isoforms have different functions. Many studies provide evidence in support of the first two statements [Piperno et al., 1990: J Cell Biol 110:379–389; Kagami and Kamiya, 1992: J Cell Sci 103:653–664; Gibbons, 1995: Cell Motil Cytoskeleton 32:136–144; Porter et al., 1996: Genetics 144:569–585; Xu et al., 1999: J Eukaryot Microbiol 46:606–611] and there is evidence that outer arms and inner arms play different roles in flagellar beating [Brokaw and Kamiya, 1987: Cell Motil. Cytoskeleton 8:68–75]. However, there are few studies rigorously testing in vivo whether inner arm dyneins, especially the 1-headed inner arm dyneins, play unique roles. This study tested the third tenet of the multi-dynein hypothesis by introducing mutations into three inner arm dynein HC genes (DYH8, 9 and 12) that are thought to encode HCs associated with 1-headed inner arm dyneins. Southern blots, Northern blots, and RT-PCR analyses indicate that all three mutants (KO-8, 9, and 12) are complete knockouts. Each mutant swims slower than the wild-type cells. The beat frequency of KO-8 cells is lower than that of the wild-type cells while the beat frequencies of KO-9 and KO-12 are not different from that of wild-type cells. Our results suggest that each inner arm dynein HC is essential for normal cell motility and cannot be replaced functionally by other dynein HCs and that not all of the 1-headed inner arm dyneins play the same role in ciliary motility. Thus, the results of our study support the multi-dynein hypothesis [Asai, 1995: Cell Motil Cytoskeleton 32:129–132]. Cell Motil. Cytoskeleton 59:201–214, 2004. © 2004 Wiley-Liss, Inc.
Research Universities, Schools of Education, and the Schools: A Case Study of Implementing Cooperative Research and Extension in Education:

This article examines a 6-year effort by a major research university to implement a program of cooperative research and extension in education that involves three central features: professional intermediaries, "key school" partnerships, and cooperative research and development projects. Through an analysis of how and to what effect these features have been implemented, revisions are proposed to the cooperative extension model that could increase its value as a template for reorganizing relationships between research universities, their schools of education, and the schools. Also examined are the implications of these revisions for in K-12 schools.
A developmental perspective on character pathology.

Summary This paper argues for the value of a developmental perspective in both diagnosis and treatment. Three groups of character disorders are discussed and classified on a developmental continuum, ranging from the low-level borderline disorders through a medium level of narcissistic personality disorders to a high level of neurotic character disorders. Neurotic character disorders result from structural (ego-superego-id) conflict, whereas middle- and low-level disorders stem mainly from developmental defects and malformations. A developmental evaluation is aided by an examination of the subject's status on various lines of development. Developmental lines summarized and related to character pathology include typical anxieties, the self, defenses, moral regulations, object relations, psychosocial crises, and psychosocial phases and modes.
Taiwan Rides the Democratic Dragon

Taiwan's young democracy has evolved at remarkable speed, but the island has yet to complete a peaceful transition alternating the parties in power. The March presidential election could completely reconfigure the island's political system and its relationship with mainland China.
Presidential address: challenges facing the American Pediatric Society in 1982. Annual meeting, Washington, D.C.

Presidential Address: Challenges Facing the American Pediatric Society in 1982. Annual Meeting, Washington, D.C
Channel modeling and detector design for dynamic mode high density probe storage and nano-imaging applications

Abstract In this paper, we provide a consolidated summary of the work reported in [1], [2], [3], [4] which is based on probe based high density storage and nano-imaging using atomic force microscopy (AFM) setup. In probe based high density storage, we consider a data storage system that operates by encoding information as topographic profiles on a polymer medium. A cantilever probe with a sharp tip (few nm radius) is used to create and sense the presence of topographic profiles, resulting in a density of few Tb per in.2. The high quality factor dynamic mode operation, that is less harsh on the media and the probe, is analyzed. The read operation is modeled as a communication channel which incorporates system memory due to inter-symbol interference and the cantilever state. Next, the solutions to the maximum likelihood sequence detection problem and maximum a posterior (MAP) symbol detection problem based on the Viterbi algorithm and BCJR algorithm respectively are devised. Experimental results demonstrate that the performance of the Viterbi and BCJR detectors are several orders of magnitude better than the performance of other existing schemes. Nano-imaging has played a vital role in basic sciences as it enables interrogation of material with sub-nanometer resolution. In this paper, we also present a high speed one-bit imaging technique using dynamic mode AFM with a high quality factor cantilever. Experimental results demonstrate that our proposed algorithm provides significantly better image resolution compared to current nano-imaging techniques at high scanning speed.
On the importance of bulk activity measurements for organic electrosorption studies

Abstract The importance of considering the bulk activities of both the organic compound and of the electrolyte is discussed for the case of organic electrosorption studies. The possible errors in the determination of the relative surface excess of the organic compound due to both of these factors separately and together are discussed. It is shown that the most serious errors due to either of these causes will occur in the region of organic concentrations in which the organic compound deviates negatively from Henry's law. Equations are derived which express these errors.
Postural effects in tetralogy of Fallot.

Abstract The postural effects upon cyanosis and dyspnea in tetralogy of Fallot, including the beneficial effects of squatting, the knee-chest and other positions, and the disadvantageous effect of standing are shown to be directly due to alterations in volume of venous return with consequent change in the oxygen saturation of mixed venous blood. Speculations are adduced to explain the peculiarly marked effect of altered venous return in malformations when there is venoarterial shunt, reduced pulmonary blood flow coexisting with high systemic flow and absence of a tendency to go into congestive heart failure. Diagnostically, these postural effects are important when they can be demonstrated in the form of simple clinical tests. A patient demonstrating them will respond well to systemic-pulmonary anastomosis. Therapeutically, they are of real importance in carrying a patient through the period of waiting for definitive surgery.
Characterization of Oleoyl-12-Hydroxylase in Castor Microsomes Using the Putative Substrate, 1-Acyl-2-Oleoyl-sn-Glycero-3-Phosphocholine

We have characterized the oleoyl-12-hydroxylase in the microsomal fraction of immature castor bean using the putative substrate, 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine (2-oleoyl-PC). Previous characterizations of this enzyme used oleoyl-CoA as substrate and relied on the enzyme transferring oleate from oleoyl-CoA to lysophosphatidylcholine to form 2-oleoyl-PC (acyl-CoA:lysophosphatidylcholine acyltransferase) in addition to oleoyl-12-hydroxylase. The present assay system and characterization use 2-oleoyl-PC as substrate (oleoyl-12-hydroxylase alone). Use of the actual substrate for assay purposes is important for the eventual purification of the oleoyl-12-hydroxylase. Ricinoleate (product of oleoyl-12-hydroxylase) and linoleate (product of oleoyl-12-desaturase) were identified as metabolites of oleate of 2-oleoyl-PC by high-performance liquid chromatography and gas chromatography/mass spectrometry. The activity of oleoyl-12-hydroxylase in the microsomal fraction reached a peak about 44 d after anthesis of castor, while the activity of oleoyl-12-desaturase reached a peak about 23 d after anthesis. The optimal temperature for the oleoyl-12-hydroxylase was about 22.5°C, and the optimal pH was 6.3. Catalase stimulated oleoyl-12-hydroxylase while bovine serum albumin and CoA did not activate oleoyl-12-hydroxylase. The phosphatidylcholine analogue, oleoyloxyethyl phosphocholine, inhibited the activity of oleoyl-12-hydroxylase. These results further support the hypothesis that the actual subtrate of oleoyl-12-hydroxylase is 2-oleoyl-PC.
A Nb/sub 3/Sn high field dipole (for SSC)

A dipole magnet approximately 1-m long with an 8-cm bore has been fabricated from cable made from Nb/sub 3/Sn multifilamentary strands. The coil consists of four layers of conductor wound in pairs to eliminate internal joints. Each set of layers is separately constrained with Kevlar-epoxy bands, and the complete assembly is clamped in a split laminated iron yoke. The inner coil pairs were wound before heat treating, whereas the outer coils were formed for prereacted cable using conventional insulation. A NbTi version of the magnet was fabricated using Superconducting Super Collider (SSC) conductor to test the construction techniques. This magnet reached a maximum central field of 7.6 T, at 4.4 K, which is very close to the limit estimated from conductor measurements. The Nb/sub 3/Sn magnet, however, only reached a maximum field at 8.1 T, which is considerably short of the field expected from measurements on the inner cable.
The challenges of integrating multi-omic data sets

The capability to generate multi-omic data sets raises the issue of resource allocation for data generation versus data curation and integration. The initial experience of researchers shows that the effort required for the latter can be much greater than that for the former.
A graph-theoretical analysis of Kelly's repertory grid

Kelley's (\ 955) repertory grid is an innovative psychological test designed to reveal the way in which a person uses concepts to view important individuals in his life. Although there are many ditlerent forms and methods of administering the grid (see Bannister & Mail'. 19(8). the basic technique is simple. The individual being ~ested is given a form with a set of role categories across the top and IS asked to till in the names of specitic people for each role. The examiner then picks successive sets of three individ uals and asks the subject how, in some important way. two of the individuals are alike and different from the third. In answering, the subject has generated a conceptual dimension (a "bipolar construct" in Kelly's terminology) and can then rate at which end of the dimension the other individuals fall. Each time this is done. a row of the form is tilled in. Thus. at the end of the test. one has a binary matrix. The completed grid is rich in information. and a variety of methods have been devised for analyzing it. Natural questions one might ask are: which conceptual dimensions are used analogously and which individuals are viewed as being similar. A method to answer these questions. based on a graph-theoretical analysis of the grid data. has been formulated and a computer program to perform the analysis has been implemented. It is necessary to introduce a few concepts from graph theory before describing the method and associated program. Graph·theoretical formulation. A graph. G = (V, E). consists of a tinite nonempty set. V, of "points" and a set. E. of pairs of points termed "edges." Given the data from a completed grid. two types of graphs can be formed. The tirst type is a persoll-graph. in which each individual is associated with a point of the graph and there is an edge between a pair of points just in case the pairs of individuals are viewed to be suitably similar. The second type of graph is a cOllstmet-graph. in which each construct is associated with a point of the graph and there is an edge between a pair of points just in
Are statins indicated for the primary prevention of coronary heart disease in octogenarians? protagonist viewpoint.

Statins should be given to octogenarians for primary prevention of coronary heart disease. There is a substantial burden of disease and disability in this population that statin treatment can address in an effective manner. It has been shown that statin treatment is both effective and safe, and details of the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) trial are reviewed. It may be useful to “tease out” those at particularly high risk who would benefit from statin treatment. In this regard, a low high-density lipoprotein cholesterol level, high-sensitivity C-reactive protein level, and subclinical measures of atherosclerosis may be particularly useful.
Concordance of Retinal Nerve Fiber Layer Defects between Fellow Eyes of Glaucoma Patients Measured by Optical Coherence Tomography

Purpose To determine the pattern of agreement of retinal nerve fiber layer (RNFL) defects between fellow eyes of glaucoma patients measured with optical coherence tomography (OCT). Design Observational, cross-sectional study. Methods Seventy-seven glaucoma patients (154 eyes) underwent OCT (Stratus) imaging with the fast RNFL thickness protocol in both eyes. RNFL thickness at each location (12 clock-hour sectors and 4 quadrants) was measured. Main outcome measures were correlations between fellow eyes for RNFL thickness and categorical classifications of RNFL thickness. Nonfellow pairs of eyes, matched randomly, were used as controls. Results Fellow eyes showed significant correlations of RNFL thickness in all sectors and quadrants. Categorical ranking also showed significant agreement between fellow eyes in sectors 1 ( P P P P P Conclusions The measurement of RNFL thickness and its categorical classification with OCT identified symmetry between fellow eyes of glaucoma patients. Categorical agreement on defective locations was found mostly for the inferior and superior locations, which corresponds with the typical pattern of early glaucomatous damage. Glaucomatous RNFL damage in 1 eye is correlated with damage at corresponding locations of the fellow eye.
Ultrasonic vocalizations by male hamsters: parameters of calling and effects of playbacks on female behaviour

Male and female hamsters, Mesocricetus auratus, were observed during prolonged matings. Ultrasonic vocalizations by the male were frequent initially and declined during testing, but were positively associated with the duration of female lordosis. Most calls were uttered while sniffing the female, although early in the test period when most ejaculations were occurring, high rates were also observed during non-contact behaviour such as grooming. Following exposure to the first female, introduction of a novel female stimulated the return of high rates of male calling. In a follow-up experiment, males uttered more ultrasonic calls in the 30-s period following ejaculation than in the preceding 30-s interval. These results provide evidence that males utter ultrasonic vocalizations that enhance lordosis during extended sexual interactions, and that the patterns of male calling are consistent with behaviours that maintain receptivity and ensure successful fertilization. Two other experiments examined whether different male calls have different effects on female behaviour. Males utter at least two structurally distinct types of ultrasonic vocalizations during sexual behaviour: one is produced during interaction with a female in lordosis (during-female), and the second is uttered following removal of the female (post-female). In the first experiment, playbacks of during- and post-female calls were equally effective in prolonging the duration of lordosis in females relative to taped noise. In a second experiment, however, tape-recorded post-female calls induced more ultrasonic vocalizations from females than during-female calls; both call types elicited more calling from females than taped noise. Therefore, although there were differences in potency, during- and post-female calls did not differ in the types of responses elicited from females under two different conditions. Thus, these male calls induce context-appropriate responses in females. In a final eperiment, structural differences were found in the male vocalizations occurring just before and after ejaculation. Together, these experiments show that ultrasonic vocalizations by male hamsters consistently vary in rate and structure during sexual interactions, and suggest that the responses of females may vary accordingly.
Acid loading during treatment with sevelamer hydrochloride: Mechanisms and clinical implications

Acid loading during treatment with sevelamer hydrochloride: Mechanisms and clinical implications. Short-term and long-term studies indicate that patients treated with sevelamer hydrochloride have lower serum bicarbonate levels than patients treated with calcium-containing phosphate binders. This observation has previously been attributed to withdrawal of a source of base with discontinuation of calcium carbonate or calcium acetate. However, understanding of the chemistry of sevelamer hydrochloride suggests at least three potential mechanisms whereby it might induce a dietary acid load. Moreover, preliminary results from an animal model demonstrate that treatment with sevelamer hydrochloride results in a fall in urine pH, as well as an increase in urinary ammonium and calcium excretion consistent with an increase in net acid excretion. Chronic metabolic acidosis in maintenance dialysis patients is associated with major systemic effects. It is independently associated with an increased risk of death in dialysis patients. Metabolic acidosis has both catabolic and antianabolic effects that may lead to a net negative nitrogen balance and total body protein balance. Metabolic acidosis also leads to physiochemical dissolution of bone and promotes cell-mediated bone resorption due to enhanced osteoclast activity and reduced osteoblast activity. It may also exacerbate secondary hyperparathyroidism and renal osteodystrophy. Given the long-term risks of chronic metabolic acidosis in maintenance dialysis patients, Kidney/Dialysis Outcome Quality Initiative (K/DOQI) guidelines have recently recommended maintaining predialysis serum levels of CO2 above 22 mmol/L in order to improve bone histology, and to ameliorate excess protein catabolism.
Enzyme localization in the anaerobic mitochondria of Ascaris lumbricoides.

Mitochondria from the muscle of the parasitic nematode Ascaris lumbricoides var. suum function anaerobically in electron transport-associated phosphorylations under physiological conditions. These helminth organelles have been fractionated into inner and outer membrane, matrix, and intermembrane space fractions. The distributions of enzyme systems were determined and compared with corresponding distributions reported in mammalian mitochondria. Succinate and pyruvate dehydrogenases as well as NADH oxidase, Mg++-dependent ATPase, adenylate kinase, citrate synthase, and cytochrome c reductases were determined to be distributed as in mammalian mitochondria. In contrast with the mammalian systems, fumarase and NAD-linked "malic" enzyme were isolated primarily from the intermembrane space fraction of the worm mitochondria. These enzymes are required for the anaerobic energy-generating system in Ascaris and would be expected to give rise to NADH in the intermembrane space. The need for and possible mechanism of a proton translocation system to obtain energy generation is suggested.
DETERMINATION OF CARDIAC OUTPUT USING ACOUSTIC QUANTIFICATION IN CRITICALLY III PATIENTS

Abstract The reliability of automated acoustic quantification (AQ) in yielding real-time left ventricular (LV) area, volume, and ejection fraction has been validated. The purpose of this study was to explore the potential of AQ in providing accurate immediate determination of cardiac output in critically ill patients. A total of 48 patients were studied. One group consisted of 37 critically ill patients with indwelling Swan-Ganz catheters. In these patients, cardiac output by AQ, manual tracing of end-diastolic and end-systolic frames of 2-dimensional images, and thermodilution were measured. AQ was also compared with Doppler calculation of flow through the left and right ventricles in 11 additional patients. Adequate data for calculation of cardiac output with AQ were obtained in 78% of critically ill patients. There was an excellent correlation between AQ and off-line manual analysis for LV volumes (r = 0.94 and 0.91 for end-diastole and end-systole), ejection fraction (r = 0.85), and cardiac output (r = 0.93). AQ also correlated well with Doppler analysis (r = 0.97) and thermodilution technique (r = 0.95) in the determination of cardiac output. However, AQ slightly underestimated thermodilution measurements, with rather wide limits of agreement (−0.3 ± 1.1 liter/min). There was a similar underestimation of cardiac output with manual analysis when compared with thermodilution. Given the absence of significant differences between AQ and manual analysis, this observation suggests that the bias is related to the echocardiographic determination of stroke volume, and not to errors from the automated border detection. It is concluded that AQ, besides providing information on LV volumes and ejection fraction, also can yield rapid measurements of cardiac output in most patients who are acutely ill.
Changes in pulse character and mental status are late responses to central hypovolemia.

Objective. Manual assessment of radial arterial pulse character remains an important determinant of physiological status in military andcivilian casualties. This study hypothesized that changes in radial pulse character andmental status (presyncopal symptoms) in humans occur only during the later stages of progressive reductions in central blood volume in close association with systolic blood pressure (SBP). Methods. Pulse character (i.e., normal, weak, absent), estimated stroke volume (SV), SBP, anddiastolic blood pressure were measured continuously during baseline supine rest andduring progressive reductions of central blood volume to cardiovascular collapse with application of lower body negative pressure (LBNP) in 19 healthy human volunteer subjects. Results. LBNP resulted in a progressive reduction in SV. At early stages of LBNP, both radial pulse character andSBP were well-maintained. Although both radial pulse character andSBP decreased with subsequent increases in LBNP, these changes occurred only...
Should There Be a Different Cardiovascular Prevention Polypill Strategy for Women and Men

The concept of a polypill for cardiovascular disease prevention has attracted widespread attention since Wald and Law’s seminal paper in 2003. The authors estimated > 80% reduction in coronary heart disease and stroke deaths through mass application of a polypill in people aged 55 years and older. Although their proposition has been subject to criticisms and heated debate regarding side effects, efficacy, and appropriateness of the intervention, few have discussed the differential risks and benefits of a polypill for women and men and whether sex-specific polypill strategies should be developed. In this review, we discuss the benefits and drawbacks of sex-specific polypill strategies by evaluating the published literature regarding 1) sex differences in cardiovascular risk and risk reduction, 2) risks and benefits of a polypill in women compared to men, 3) anticipated hurdles to implementing a polypill strategy, 4) special considerations related to low- and middle-income country settings, and 5) potential sex-specific polypill strategies.
The effects of barium ions on some stimulus evoked excitatory post-synaptic potentials in the brain of Helix pomatia L.

Abstract 1. 1. The effects of barium ions on the stimulus evoked fast and slow EPSPs of the snail brain have been studied using intracellular methods. 2. 2. Most of the stimulus-evoked slow, fast and compound EPSPs were facilitated if barium ions were present in a calcium containing solution. 3. 3. The barium induced facilitation could be evoked by indirectly or directly depending on the barium doses. 4. 4. Raising the Mg 2+ and/or decreasing the Ca 2+ concentration in the bathing solution depressed or totally blocked the barium evoked facilitatory actions. 5. 5. Causing conduction blockage and ion deficiency, Na + -free solution abolished the stimulus evoked responses, and neither functions of the sodium ions were substituted by barium ions. 6. 6. Barium ions were, in most cases, unable to substitute for calcium ions in the stimulus evoked chemical transmission process. 7. 7. Barium ions depolarize the terminals, probably shield the membrane charges, and influence the intraterminal charge distribution, all of which may be factors of the facilitated transmitter release.
Sex and Ethnicity as Moderators in the Sexual Harassment Phenomenon: A Revision and Test of Fitzgerald et al. (1994)

Fitzgerald, Hulin, and Drasgow (1994) proposed that personal vulnerability characteristics (such as sex and ethnicity) would moderate the effect of sexual harassment on its outcomes. This paper argues that personal vulnerability characteristics instead moderate the effect of organizational sexual harassment climate on sexual harassment because of their role as identity markers within social hierarchies. Using a sample of nearly 8,000 male and female military personnel from four ethnicity groups, the proposition that organizational climate differentially affects sexual harassment frequency across sex and ethnicity was evaluated. Results suggested that sex is an important moderator of these relationships, but that ethnicity is not. Further, sex and ethnicity were not found to moderate the effect of sexual harassment on its outcomes. Potential generalizability of these results to other types of harassment (e.g., racial harassment, bullying), as well as needed future research in this area, is discussed.
DISTORÇÕES FLEXÍVEIS DO DIREITO AMERICANO, OU COMO SÃO PAULO E SÃO JOÃO INFLUENCIAM A POLÍTICA SOCIAL FUNDAMENTAL

This article aims to demonstrate how to preserve the possibility of a laudable change within interpretive limits, through the gradual restoration of five flexible misreadings of the US Constitution.
Heavy Transversals and Indecomposable Hypergraphs

A weighted hypergraph is a hypergraph H = (V, E) with a weighting function $$w:V \to R$$, where R is the set of reals. A multiset S ⊆ V generates a partial hypergraph HS with edges $${\left\{ {e \in E{\kern 1pt} :{\kern 1pt} {\left| {e \cap S} \right|} > w{\left( S \right)}} \right\}}$$, where both the cardinality $${\left| {e \cap S} \right|}$$ and the total weight w(S) are counted with multiplicities of vertices in S. The transversal number of H is represented by τ(H). We prove the following: there exists a function f(n) such that, for any weighted n-Helly hypergraph H, τ(HB) ≤ 1, for all multisets B ⊆ V if and only if τ(HA) ≤ 1, for all multisets A ⊆ V with $${\left| A \right|} \leqslant f{\left( n \right)}$$. We provide lower and upper bounds for f(n) using a link between indecomposable hypergraphs and critical weighted n-Helly hypergraphs.
Adoptive Mothers: Identity Agents on the Pathway to Adoptive Identity Formation

The concept of identity agents provides a framework to examine adoptive mothers' responsibility to address children's dual connection to their birth and adoptive families. Adoptive mothers' identity agency was assessed using case analysis. Eight extensive interviews with four adoptive mothers were collected at Waves 1 and 2 of a longitudinal study. Adoptees' identity formation was measured at Waves 2 and 3. Adoptees were M = 6, 13, and 23 years of age at Waves 1, 2, and 3, respectively. Analysis revealed strategies that adoptive mothers purposefully employ during their children's childhood and adolescence to influence subsequent adoptive identity. Adoptive mothers who act as identity agents draw on their respective theories of identity formation to create opportunities to talk with their children about adoption.
Mechanics and micromechanisms of fatigue crack growth in brittle solids

This paper is concerned with the mechanics and micromechanisms of stable mode I crack growth in brittle solids subjected to compression—compression fatigue and tension—tension fatigue loads. Constitutive models, results of finite element analyses, and experimental observations are described for monolithic ceramics and ceramic-matrix composites, plain concrete, and a transformation-toughened ceramic in an attempt to deduce a general theory on the origin of mode I fracture in notched plates under uniaxial cyclic compression at room temperature. An analysis of the residual stress field which develops at elevated temperatures in response to power law creep and far-field compressive cyclic loads is also presented. The principal “driving force” for mode I fracture in cyclic compression is the generation of a near-tip zone of residual tension, when the deformation at the notch-tip leaves permanent strains upon unloading from the far-field compressive stress. The results indicated that materials with very different microscopic deformation mechanisms, i.e., microcracking, dislocation plasticity, martensitic transformation, interfacial debonding/slip, or creep, exhibit a macroscopically similar, stable fracture under far-field cyclic compression because the zone of residual tension is embedded in material which is elastically strained in compression. It is shown that cyclic compression loading offers a unique method for fatigue precracking notched specimens of brittle solids prior to tensile fracture testing, whereby an unambiguous interpretation of the critical stress intensity factors for crack initiation and growth can be achieved. Fatigue crack growth characteristics of a transformation-toughened ceramic and a creeping ceramic composite under tension—tension fatigue loads are also discussed.
Computation of algebraic formulas for wigner 3-j, 6-j, and 9-j symbols by maple

Three programs capable of computing algebraic formulas for Wigner 3-j, 6-j, and 9-j symbols have been written in the Maple* program language. These programs can also compute numerically exact values of 3-j, 6-j, and 9-j symbols. © 1994 John Wiley & Sons, Inc.
A comparison of propofol and remifentanil during monitored anesthesia care.

Study Objective To compare remifentanil, an esterase-metabolized opioid, to a standard propofol-based sedation technique for monitored anesthesia care (MAC). Design Non-randomized, open label. Setting University hospital. Patients 44 healthy female outpatients undergoing breast biopsy procedures under local anesthesia. Interventions All patients received intravenous (IV) midazolam 2 mg, followed by a continuous infusion of either propofol 75 μg/kg/min, or remifentanil 0.1 μg/kg/min, which was subsequently titrated to maintain optimal patient comfort without respiratory depression. Surgical-related pain was treated by injecting additional local anesthetic solution and "rescue" boluses of fentanyl 25 μg IV. Measurements and Main Results Sedation, pain, and discomfort were monitored using standardized rating scales at 1 to 5 minute intervals. Recovery times were measured from the end of the study drug infusions. Propofol resulted in significantly higher median sedation scores compared with remifentanil, with 73% of patients requiring a decrease in the propofol infusion rate because of "excessive" sedation. Local anesthetic requirements, pain, and discomfort scores during surgery were similar in both groups. Remifentanil resulted in greater respiratory depression compared with propofol, with decreases in the remifentanil infusion rate required by 41 % of patients because of a slow respiratory rate ( 2 Conclusion Remifentanil provided comparable intraoperative conditions and patient comfort at a lower sedation level compared with propofol. However, remifentanil was associated with greater respiratory depression and a longer time to home readiness.
Chemical Transfer of Learned Fear

RESULTS reported earlier1–5 have suggested that acquired information can be transmitted to naive animals by giving them material extracted from the brain of trained subjects. In most of these experiments, as in others6–11, transfer of information was suggested by varying degrees of statistical probability and it was challenged by negative results obtained in other laboratories12.
Therapeutic potential of oligonucleotides expressing immunosuppressive TTAGGG motifs

Synthetic oligodeoxynucleotides (ODNs) expressing immunosuppressive TTAGGG motifs downregulate the production of proinflammatory and Th1 cytokines. The ability of these "suppressive ODNs" to slow or prevent the development of diseases characterized by over-exuberant immune stimulation was examined. Suppressive ODNs significantly reduced disease severity in murine models of arthritis, lupus, and LPS-induced toxic shock. These beneficial effects were accompanied by a significant reduction in serum autoantibody and cytokine levels. Underlying these protective effects was the ability of suppressive ODNs to bind to and prevent the phosphorylation of STAT1 and STAT4, thereby blocking the signaling cascade central to the initiation and/or perpetuation of these disease states. These findings suggest that suppressive ODNs might find use in the treatment of acute and chronic diseases characterized by excessive immune stimulation.
Room temperature polyesterification

A new room temperature polymerization method has been developed for the synthesis of high molecular weight polyesters directly from carboxylic acids and phenols. The solution polymerization reaction proceeds under mild conditions, near neutral pH, and also avoids the use of preactivated acid derivatives for esterification. The reaction is useful in the preparation of isoregic ordered chains with translational polar symmetry and also in the polymerization of functionalized or chiral monomers. The conditions required for polymerization in the carbodiimide-based reaction included catalysis by the 1:1 molecular complex formed by 4-(dimethylamino)pyridine and p-toluenesulfonic acid. These conditions were established through studies on a model system involving esterification of p-toluic acid and p-cresol. Self-condensation of several hydroxy acid monomers by this reaction has produced routinely good yields of polyesters with molecular weights greater than 15,000. It is believed that the high extents of reaction required for significant degrees of polymerization result from suppression of the side reaction leading to N-acylurea. The utility of this reaction in the formation of polar chains from sensitive monomers is demonstrated hereby the polycondensation of a chiral hydroxy acid.
Competing Gridlock Models and Status Quo Policies

Spatial theories of lawmaking predict that legislative productivity is increasing in the number of status quo policies that lie outside the gridlock interval, but because locations of status quo policies are difficult to measure, previous empirical tests of gridlock theories rely on an auxiliary assumption that the distribution of status quo points is fixed and uniform. This assumption is at odds with the theories being tested, as it ignores the history dependence of lawmaking. We provide an alternative method for testing competing theories by estimating structural models that explicitly account for temporal dependence in a theoretically consistent way. Our analysis suggests that legislative productivity depends both on parties and supermajority pivots, and we find patterns of productivity consistent with a weaker, contingent form of party influence than found in previous work. Parties appear to exert agenda power only on highly salient legislation rather than strongly influencing outcomes through voting pressure and party unity.
Efficient expression of the Saccharomyces cerevisiae glycolytic gene ADH1 is dependent upon a cis-acting regulatory element (UASRPG) found initially in genes encoding ribosomal proteins.

Abstract The glycolytic form of alcohol dehydrogenase (ADHI) is encoded by the ADHI gene of Saccharomyces cerevisiae. We found that efficient expression of the ADH1 gene requires a sequence between bp −635 and −615 with respect to the + mRNA start point; removal of this sequence reduced ADH1 mRNA levels 25-fold but did not affect carbon-source regulation. DNAaseI footprinting analysis of the ADH1 promoter revealed the specific protection of a perfect match to UASRPG at −630 to −615. UASRPG is thought to be responsible for activation of transcription, via binding of the translation upstream factor (TUF), of genes encoding components of the translational appaatus. In band retardation assays, the promoters for the elongation factor 1α-encoding genes (TEF1 and TEF2) competed for binding of the protein to the copy of UASRPG in the ADH1 promoter. We conclude that TUF is probably involved in activation of the bulk of ADH1 transcription. Further, we propose that TUF has a role in the activation of many or most glycolytic genes. If so, it is essential for efficient expression of a wide variety of functionally disparate products that are required by yeast cells for rapid growth.
A comparison of sentence-learning errors in children of different achievement levels

Abstract Theoretical analyses of the multiple-choice test format suggest that a test constructor should give serious consideration to the form in which correct and incorrect alternatives are presented. In this experiment, third and fourth graders were tested for previously exposed information by multiple-choice items in which: (a) correct alternatives were stated in either verbatim or synonym form; and (b) incorrect alternatives consisted of plausible responses that were either familiar or new. Comparisons of errors and error patterns were made between high and low achieving students who had been given one of two different information-processing strategies. Based on a dual test function argument, it was concluded that synonym correct alternatives combined with plausible new responses are the most desirable of the four multiple-choice variations studied here. In particular, such items were sensitive to achievement level and strategy differences without systematically increasing students' likelihood of retaining misinformation.
Depiction of celiac ganglia on positron emission tomography and computed tomography in patients with lung cancer

article i nfo Objective: To differentiate imaging characteristics of celiac ganglia from metastatic lesion on positron emission tomography-computed tomography (PET-CT) in patients with lung cancer and correlate these findings to postmortem multidetector row computed tomography (MDCT). Methods: One hundred twenty- nine patients were included. Imaging characteristics and fluorodeoxyglucose (FDG) avidity of the celiac ganglia were recorded. Postmortem MDCT of 20 subjects were reviewed. Results: Celiac ganglia were identified unilaterally in 127 and bilaterally in 108 patients without abnormal FDG uptake. Postmortem images showed celiac ganglia in all cases with no significant difference compared to our patients. Conclusions: Familiarity with CT characteristics and FDG-avidity of celiac ganglia enable us to distinguish them from metastatic lesions in their vicinity.
Basic Biological Sciences Application of an X-ray Image Magnifier to the Microradiography of Dental Specimens

A highly parallel incident x-ray beam combined with x-ray image magnification was used to obtain high-resolution microradiographs of dental specimens. Preliminary results obtained using a rotating anode x-ray generator show that limitations associated with conventional contact microradiography regarding spatial resolution, sample thickness, and sample orientation, relative to the film, were significantly reduced.
Modeling the Proposed Intermediate in Alkane Carbon-Hydrogen Bond Activation by Cp*(PMe3)Ir(Me)OTf: Synthesis and Stability of Novel Organometallic Iridium(V) Complexes

Addition of HX to CH{sub 2}Cl{sub 2} solutions of Cp{sup *}IrMe{sub 4} (Cp{sup *} = {eta}{sup 5}-C{sub 5}Me{sub 5}) at low temperature provided Cp{sup *}Ir(Me){sub 3}X (X = Cl, 5; X = OSO{sub 2}CF{sub 3} = OTf, 6). Both complexes are very thermally sensitive yet proved to be useful precursors for novel cationic iridium(V) complexes. Treatment of 6 with a variety of trisubstituted phosphines, arsines, and stibines (L) afforded compounds 7--12, [Cp{sup *}(L)IrMe{sub 3}][OTf] (L = PMe{sub 3}, 7; L = PEt{sub 3}, 8; L = PPh{sub 3}, 9; L = AsEt{sub 3}, 10; L = AsPh{sub 3}, 11; L = SbPh{sub 3}, 12). Metathesis of the triflate anion of antimony complex 12 for the tetraphenylborate anion afforded [Cp{sup *}(SbPh{sub 3})IrMe{sub 3}][BPh{sub 4}] (13). The molecular structure of 13 was determined by single-crystal X-ray diffraction analysis. Complex 7 is a potential model for the proposed intermediate on the methane carbon-hydrogen bond activation reaction pathway by Cp{sup *}(PMe{sub 3})Ir(Me)OTf, and its relevance to this reaction is discussed. Complex 7 decomposed by reductive elimination of MeCp{sup *}. The remaining iridium fragment was trapped by added phosphine to form [cis-{l_brace}PMe{sub 3}{r_brace}{sub 4}IrMe{sub 2}][OTf] (14) as an impure mixture. Reaction of 6 with excessmore » dppm (dppm = Ph{sub 2}PCH{sub 2}PPh{sub 2}) afforded [cis-{l_brace}{eta}{sup 2}-Ph{sub 2}PCH{sub 2}PPh{sub 2}{r_brace}{sub 2}IrMe{sub 2}][OTf] (15). The molecular structure of 15 was determined by single-crystal X-ray structure analysis.« less
Functional variation of dual gate MOS-JFET CCD test structure

Drain voltages of a test structure of dual gate MOS-JFET CCD (TIJ J032) were measured by an advanced laser scanner. The potential variation of the test structure at various source and gate voltages were measured by monitoring drain voltages with respect to the scanning laser position. In this report, a fine continuous, constant energy He-Ne laser beam of the Multipurpose Microelectronic Advanced Laser Scanner is utilized for the characterization of local variation of the sensor performance within the test structure.
NexFET generation 2, new way to power

In this paper, an integrated NexFET power module is presented to meet requirements on next-generation, high efficiency and high current density DC-DC converters for computer applications. The new power module uses an innovative stacked-die package technology, implements low Vth power MOSFET in the low-side position, and introduces monolithically integrated components to avoid shoot-through and minimize voltage ringing at the switch node. In synchronous buck application, this power module achieves over 90% efficiency and low switch node ringing at high output current rating (25A) and high operation frequency (1MHz) under 12V input and 1.3V output condition.
Aluminum Effects on Calcium Uptake and Translocation in Wheat Forages

The effects of Al on Ca transport could influence Ca accumulation in plants. Low forage Ca concentrations may cause hypocalcemia, a Ca deficiency syndrome of ruminants. Solution culture experiments were conducted in a growth chamber to examine the effects of Al (5-50 μM) on uptake and translocation of Ca ( 45 Ca) in winter wheat (Triticum aestivum L.) cultivars (Al-tolerant Atlas 66 and Al-sensitive Scout 66). Three-day-old seedlings, grown either in a CaCl 2 solution (0.1 or 1.0 mM) or in a complete-nutrient solution, were used. For plants grown in CaCl 2 solution, addition of 5 μM Al significantly decreased Ca uptake and translocation in Scout 66, but not in Atlas 66. Higher levels of Al (20 and 50 μM decreased Ca uptake and translocation much more in Scout 66 than in Atlas 66 [...]
Demarcation membrane system in rat megakaryocyte and the mechanism of platelet formation: a membrane reorganization process.

The origin and development of the demarcation membrane system (DMS) in rat megakaryocyte and the mechanism of platelet demarcation was studied by freeze-fracture technique (FF). Correlated with thin-sectioning electron microscopy, tangentially fractured DMS appear as sheets of fenestrated membranes within the megakaryocyte cytoplasm. The DMS is finely granular and contains membrane-associated particles (MAP). When DMS is fractured transversally, a canal system is disclosed, of which the basic elements are single tubules with an average width of 150 nm, containing the equilibrating substance and surrounded by a single membrane. Bead-like chains of these tubules are seen lying side by side and are interconnected by bridges formed by membrane attachments. These tubules are continuous with randomly distributed invaginations seen on the megakaryocyte plasma membrane (MPM). The continuity of the lumen of these tubules with the extracellular space was confirmed when lanthanum, an extracellular tracer, readily penetrated the tubules. Size distribution of MAP on platelet plasma membranes, DMS, and megakaryocyte plasma membranes indicated similarities suggesting a common origin. Based on these observations, we propose a model for the process of platelet demarcation and thrombocytogenesis. We propose that the DMS originates by invagination at multiple sites from the MPM. This results in the formation of tubules within the cytoplasm of megakaryocytes. These tubules may branch and then interconnect forming a continuous network of tubules. The next step is the formation of flat membranes from the membranes of these tubes. The tubes lie side by side, parallel in their long axes, with multiple points of fusion occurring between their membranes. Each tubule is in the process of becoming two hemicylinders, the edges of which are cojoined to the edges of the contiguous hemicylinders. The fused walls of parallel tubes may be visualized in the plane of their long axes as becoming a scalloped membrane, facing a similar membrane of corresponding hemicylinders. The two scalloped membranes can then come apart, each surrounding a volume of cytoplasm which is a prospective platelet.