cssi/SciSciGPT-SciSciNet huggingface dataset:
Merleau-Ponty and the existential conception of science

Maurice Merleau-Ponty is best known as a philosopher of science for his detailed investigations of psychology. Perhaps because of this, the significance of his work for a broader philosophical reflection on science has been overlooked. But Merleau-Ponty intended his work as a general investigation of the epistemological and ontological status of meaning and structure. The structures discovered through research in solid-state physics or molecular biology must be included within the scope of his inquiry as much as the more primary perceptual structures of color or visual depth. It is true that he often insists that science cannot account for or understand a particular phenomenon, and goes on to contrast his phenomenological discoveries with the inadequate analyses produced by science. But when Merleau-Ponty speaks of 'science' in this way, he uses the term interchangeably with 'objective thought'. The task remains to show that scientific investigation can also be freed from the traditional prejudices of objective thought, and exhibited as a mode of human existence. Merleau-Ponty himself is admittedly ambivalent about this possibility, and he rarely thematizes scientific research in the course of his investigations. The aim of this paper, however, is to develop an existential conception of science within the context of Merleau-Ponty's work. It seems clear to me that his project cannot be completed unless it incorporates science, and not just the body and the perceived world, poetry and history, painting and love. Already in La Structure du Comportement, Merleau-Ponty insists that the concept of 'structure' or 'form' employed by the Gestalt psy chologists must be extended to the physical sciences as well.
The persistence of electrostatically seeded endothelial cells lining a small diameter expanded polytetrafluoroethylene vascular graft.

Purpose: The purpose of this study was to evaluate the persistence of electrostatically seeded endothelial cells (ECs) lining an expanded polytetrafluorethylene (e-PTFE) graft after one week exposu...
Toward a Theory of Growing Surfaces: Mapping Two-Dimensional Laplacian Growth Onto Hamiltonian Dynamics and Statistics

I show that the evolution of a two-dimensional surface in a Laplacian field can be described by Hamiltonian dynamics. First, the growing region is mapped conformally to the interior of the unit circle, creating in the process a set of mathematical zeros and poles that evolve dynamically as the surface grows. Then the dynamics of these quasi-particles are analyzed. A class of arbitrary initial conditions is discussed explicitly, where the surface-tension-free Laplacian growth process is integrable. This formulation holds only as long as the singularities of the map are confined to within the unit circle. But the Hamiltonian structure further allows for surface tension to be introduced as an energetic term that effects repulsion between the quasi-particles and the surface. These results are used to formulate a first-principles statistical theory of pattern formation in stochastic growth, where noise is a key player.
Mechanism of quenching of fluorescein by anti-fluorescein IgG antibodies☆

Abstract The mechanism by which fluorescein underoges a spectral shift and its fluorescence is quenched when bound to rabbit anti-flurescyl IgG antibody, has been investigated. Visible absorption spectra of the fluorophore bound to the active site of purified antibody elicited to the two isomers of fluorescein (I and II) revealed different spectral shifts, suggesting that the active sites of the two proteins were different. This interpretation was supported by difference spectroscopy of fluorescein bound to the two antibody preparations. Dissolution of fluorescein in various solvents showed that alcohols produced absorption profiles similar to those of bound ligand. The relative reduction in the quantum yield of fluorescence of the antibody bound dye with respect to free fluorescein was found to be extensive (≈90%). Screening of individual amino acids for the ability to quench the fluorescence of fluorescein resulted in the finding that tryptophan and to some extent tyrosine were effective quenchers. Stern-Volmer analyses and fluorescence lifetine measurements of tryptophan quenching revealed a complex mechanism of fluorescein/tryptophan interaction, involving both static and dynamic components. Titration of anti-fluorescein antibody with fluorescein showed that the fluorescence emission of excited tryptophanyl residues within the antibody active site were quenched upon the binding of the fluorophore, thus suggesting that tryptophan is indeed a component of the anti-fluorescyl active site.
Magnetic resonance image abnormality in migraine with aura

Cerebral magnetic resonance imaging (MRI) was performed on 18 patients with migraine characterized by aura consisting of both visual symptoms and paresthesias. Fifteen headache-free individuals of the same age range were used as controls. Records were randomized and read in blind fashion by two neuroradiologists. Small subcortical white matter lesions were seen in three migraine cases and two controls. In one migraine case cortical infarctions were seen. In two controls, small areas of increased density similar to those in migraine were seen. No consistent correlation of migraine or its duration with cerebral atrophy was found. It is concluded that identification of both these MRI findings (small subcortical white lesions and cerebral atrophy) as significantly associated with migraine is doubtful.
Effectiveness of Emergency Medicine Experience in Third-Year Integrated Longitudinal Medical Student Programs

The LCME have raised concerns about the quality of learning afforded to medical students in traditional block clerkships. Longitudinal models have become prevalent in undergraduate medical education models as a way to improve continuity with both faculty and patients. The LCME’s update also includes many new directives that could be addressed by emergency medicine (EM). The undifferentiated emergency patient allows students to develop their diagnoses and treatment plans and acquire skills of critical judgment. At UCSF integrated longitudinal models of third year curriculum exist that include a defined emergency medicine component. Impact
Independence and Union:: Foundations of American Internationalism

David C. Hendrickson (dhendrickson@coloradocollege.edu) is the Robert J. Fox Distinguished Service Professor at Colorado College. His books include (with Robert W. Tucker) Empire of Liberty: The Statecraft of Thomas Jefferson (New York: Oxford University Press, 1990) and The Imperial Temptation: The New World Order and America’s Purpose (New York: Council on Foreign Relations Press, 1992). This essay draws from Peace Pact: The Lost World of the American Founding (Lawrence, Kan.: University Press of Kansas, 2003).
Valence Electron Cloud Asymmetry from Two Points of View: A Correlation between Mössbauer Quadrupole Splittings and 57Fe NMR Chemical Shifts of Diamagnetic Iron(II) Porphyrinates

We have prepared a series of 94.5%-enriched 57Fe(II) complexes of tetramesitylporphyrin and octaethylporphyrin having various bis- or mixed axial ligation and investigated them by both NMR and Mossbauer spectroscopy. The results obtained, and literature values for MbCO and cytochrome c, show a rough correlation between ΔEQ and δFe. This correlation suggested that the previously-reported chemical shifts of the complexes [TPPFeL2], L = pyridine-d5, and pyrrolidine (Nozawa, T.; Sato, M.; Hatano, M.; Kobayashi, N.; Osa, T. Chem. Lett. 1983, 1289) might be incorrect; we have thus used the rapid pulsing method of Schwenck to detect the signal of the bis-pyridine-d5 complex at 11 715 ppm, within its predicted chemical shift range, based upon the δFe vs ΔEQ correlation, and ∼4,400 ppm to lower shielding than originally reported. These findings emphasize the value of the Mossbauer−NMR correlation in aiding the detection of 57Fe NMR signals, as well as the perils of seeking these easily “folded” signals without suc...
House fly head GABA-gated chloride channel: Toxicologically relevant binding site for avermectins coupled to site for ethynylbicycloorthobenzoate

Abstract [5-3H]Avermectin B1a ([3H]AVM) binds in house fly head membranes to a single saturable, high affinity site (Kd 1.9 nM, Bmax 9.5 pmol/mg protein, 65% specific binding). This radioligand is not displaced by GABA and several noncompetitive blockers of the GABA-gated chloride channel [picrotoxinin, lindane, and 4-n-propyl-4′-ethynylbicycloorthobenzoate (EBOB)]. AVM and 11 analogs thereof including MK-243 and moxidectin vary in IC50s for displacement of [3H]AVM from 26 to 1025 nM and in LD50s to adult female house flies [topical, 24 hr, pretreated with piperonyl butoxide to minimize oxidative detoxification] from 0.01 to 45 μg/g. The IC50 is a good predictor of the LD50 (r = 0.83, n = 11) establishing the toxicological relevance of this [3H]AVM binding assay. These AVM analogs are also noncompetitive displacers of [3H]EBOB binding with EC50 values of 1.7 to 336 nM for the sensitive portion (45–80%) of [3H]EBOB binding. The relative potencies of a series of AVM analogs as inhibitors of [3H]AVM binding correlate well with those for [3H]EBOB binding (r = 0.95, n = 12). It therefore appears that AVM and its analogs (channel openers) act in the GABA-gated chloride channel of house fly head at a site closely coupled to that for EBOB (a channel blocker).
Bariatric surgery in adolescents: for treatment failures or health care system failures?

More and more children are obese, and more and more of them are severely obese.1 As a result, children now experience severe consequences of obesity that until recently were considered diseases of adulthood, such as type 2 diabetes. Given the serious physical morbidity of obesity as well as the profound impairment of quality of life and function, we inevitably must consider the role of bariatric surgery, an aggressive and potentially risky treatment that until recently was reserved for adults. In this issue of Pediatrics , Inge et al, a panel of experienced pediatricians and surgeons, present recommendations to guide patient selection, surgical management, and long-term follow-up.2 The panel emphasizes the risks of surgery and the paucity of data, both short-term and long-term, among adolescents. The report recommends caution in patient selection. It proposes conservative physiologic criteria based on body mass index levels, medical comorbidities, and physiologic maturity, and it endorses psychological health and family support before and after surgery. The panel recommends surgery only after the child has attempted other treatment. In fact, first on the panel’s list …
Decision support for integrated landscape evaluation and restoration planning.

Abstract The historical patterns of Inland Northwest United States forests have been dramatically altered by a little more than two centuries of human settlement and land use. Spatial patterns of forest structural conditions, tree species composition, snags and down wood, and temporal variation in these patterns, have been altered to such an extent that the natural ebb and flow of terrestrial habitats and their linkages has been disrupted. Closely coupled with these changes, fire and other disturbance processes in most dry and many mesic forest types have also shifted, with a bias for increased severity and extent. Here, in the context of planning restoration of some semblance of historical vegetation pattern–disturbance process interactions, we briefly revisit why it is theoretically sound to estimate the range and variation in historical forest spatial patterns. We call these estimates of range and variation, reference conditions or reference variation (RV), and discuss how forest managers might use them when evaluating current landscape patterns to identify changes that may have important ecological implications. We term such evaluations, departure analyses, and we describe how departure analysis is implemented in a decision support system (DSS) for integrated landscape evaluation and restoration planning. The initial phase of the DSS uses logic-based modeling to evaluate existing patterns of forest vegetation in subwatersheds of one ecoregion against a corresponding envelope of historical reference conditions for the same region, thereby highlighting key departures. The secondary planning phase uses results from the analysis phase in a decision model to prioritize watersheds for possible management actions related to landscape restoration and maintenance. We conclude from our example that there are at least two advantages to a decision-support approach that treats evaluation and planning as distinct but integrated phases: (1) the overall decision process is rendered conceptually simpler and (2) practical considerations of efficacy and feasibility of management actions can be easily accommodated.
Gravity‐observations in the maritime provinces

General statement—In the summer of 1944, 521 gravity-meter stations were established in the Maritime Provinces of Canada. This work was a cooperative venture carried out by the Dominion Observatory and the writer, representing the Special Committee for the Geological and Geophysical Study of Continents of the American Geophysical Union. The Instrument used was the X-type gravity-meter on loan to the American Geophysical Union by the Humble Oil Company. Location of stations—Most of the stations were located in the southern and eastern portions of the Province of New Brunswick and were established by A. H. Miller of the staff of the Dominion Observatory. In addition to these stations, traverses crossing southern Quebec, New Brunswick, and Nova Scotia were established by the writer assisted by Mr. Miller. All station locations are indicated on the iso-anomaly maps of New Brunswick and Nova Scotia in Figures 1 and 2.
Ultrastructural study of penetration of maize leaves by Colletotrichum graminicola

Abstract When maize leaves are inoculated with conidia of Colletotrichum graminicola the uninucleate, single-celled spores swell and undergo mitosis. In each spore a septum forms between the daughter nuclei and one cell of the resulting two-celled structure germinates to produce an appressorium with an electron-dense outer cell wall. Prior to penetration a new, inner, electron-lucent wall forms around the basal portion of the appressorium. During penetration, which occurs 6 to 9 h after inoculation, the outer dense wall of the appressorium disappears, without evidence of mechanical disruption, in the area of the developing infection peg. At all stages of infection the infection peg and the hypha which develops from it are enveloped by a distinctive, electron-lucent cell wall which is continuous with the inner wall of the appressorium. During penetration only the cuticular layers of the host cell wall are depressed inward. Dense host reaction products (papillae) are formed and the plasma membranes are disrupted before cell walls are completely penetrated and also in cells adjacent to those invaded by the fungus. The infection process is completed within 12 h by the formation of a septum between the appressorium and the swollen infection hypha.
Ice-Rafted Detritus as a Climatic Indicator in Antarctic Deep-Sea Cores

Ice-rafted detritus is readily identified in sediment cores raised from the deep ocean floor around Antarctica. A few cores have reached a depth below which no ice-rafted material is found. This depth is interpreted as indicating the establishment of earliest Pleistocene glaciation in the Southern Hemisphere. It is just below a depth where there is a change in assemblages of Radiolaria which Hays associates with the Pliocene-Pleistocene boundary. The presence of ice-rafted material throughout the upper zone in cores taken south of the Polar Front indicates continuity of glaciation in Antarctica. Further north, near 45°S in the Argentine Basin, zonation of the ice-rafted detritus can be used to delineate glacial stages of the Pleistocene.
Spontaneous calcium release from the sarcoplasmic reticulum in myocardial cells: mechanisms and consequences

Under certain conditions of Ca2+ loading, cardiac myocytes, both isolated and in intact tissue, exhibit spontaneous, oscillatory Ca2+ transients due to Ca2+ release from the sarcoplasmic reticulum. These transients are not triggered by depolarization of the sarcolemma, though they themselves can generate depolarizing currents which can reach threshold to trigger an action potential. Spontaneous Ca2+ release occurs locally in a subcellular region and, once initiated, can propagate through the cell with a velocity of roughly 100 microns/s. Locally, the cytosolic Ca2+ concentration during spontaneous release is probably comparable to that during an electrically excited twitch. The mechanisms of initiation and propagation of spontaneous Ca2+ release are uncertain, but are probably closely related to the Ca2+-induced Ca2+ release which plays a role in normal excitation-contraction coupling. Spontaneous and triggered Ca2+ release appear to compete for a common pool of releasable sarcoplasmic reticulum Ca2+, with the result that spontaneous Ca2+ release imposes a beat-rate-dependent limit on the inotropic effect of interventions which increase intracellular Ca2+. Mathematical modeling of this effect shows that it can also explain increased diastolic tone, the development of aftercontractions and oscillatory restitution of contractility in states of 'Ca2+ overload'. Spontaneous Ca2+ release is a cause of arrhythmias, and may well play a role in some cases of systolic and diastolic myocardial dysfunction.
Post-translational modifications of proteins: some problems left to solve

Three major questions regarding the post-translational modification of amino acid side chains in proteins are briefly considered: (1) What are the biological functions of the reactions, (2) what is the specificity of the processing reactions in selecting only a few or sometimes even only one residue for modification, and (3) how do we solve the uniqueness of the processing steps in the production of recombinant proteins? The answers to these questions are not obvious at this time.
Testosterone levels and sexual maturation predict substance use disorders in adolescent boys: a prospective study.

Background This investigation determined whether testosterone level and sexual maturation in boys biased development of socially nonnormative behavior culminating in a substance use disorder (SUD). Methods The subjects were 179 boys recruited in late childhood through a high-risk paradigm. Path analysis was used to evaluate the influence of testosterone level and sexual maturation in early adolescence (age 12–14) on attitudes toward antisociality, affiliation with deviant peers, and social potency in middle adolescence (age 16), illicit drug use by late adolescence (age 19), and SUD in young adulthood (age 22). Results Testosterone level predicted social potency and approval of aggressive/antisocial behavior. Sexual maturation mediated the relation between testosterone level in early adolescence and later affiliation with deviant peers. Social potency, approval of aggressive/antisocial behavior, and deviant peer affiliations predicted illicit drug use by late adolescence that in turn predicted SUD in young adulthood. Conclusions This study demonstrated that pubertal processes in early adolescence influence the risk for SUD via effects on psychosocial functioning.
The isolation of a staphylococcal phage variant susceptible to an unusual host control

A series of phage P(1) variants was isolated from plaques developing on S. aureus WF 145. One in particular, phage 14, was studied in detail because its host range appeared to be dependent on the previous host of production; i.e., it was subject to a host control. When this phage was produced on host K(1) its lysate assayed equally well on both 145 and K(1) cells. When produced on host 145, however, it assayed manyfold higher on 145 than on host K(1). All its particles adsorbed on K(1) cells, but only a small percentage were able to produce plaques. No differences could be found in adsorption rates, latent periods, or burst sizes of the phage on the two hosts. No extracellular inactivating substances could be detected which could account for such changes, nor could the results be explained readily on a mutational basis, since distinct phage strains could not be isolated. The change in virus properties was found to occur in the first burst of singly infected host 145 cells, regardless of the previous host or its prior lytic abilities. Heat inactivation destroyed activity for K(1) cells more rapidly than for 145 cells. This was found to be a property of both the stock phage P(1) and phage 14. Phage 14 could be heated until there remained particles which could multiply only on strain 145. When the plaques of such survivors were examined they were found to contain phage which could multiply on both hosts in a ratio characteristic of the original unheated preparation. The data suggest that the observed changes were caused by a host control over the formation of a phage material(s) necessary for successful infection of host K(1). Such a substance theoretically could be related to the labile material destroyed by heat and required for plaque formation on host K(1).
An image segmentation method for apple sorting and grading using support vector machine and Otsu's method

Segmentation is the first step in image analysis to subdivide an image into meaningful regions. It directly affects the subsequent image analysis outcomes. This paper reports on the development of an automatic adjustable algorithm for segmentation of color images, using linear support vector machine (SVM) and Otsu's thresholding method, for apple sorting and grading. The method automatically adjusts the classification hyperplane calculated by using linear SVM and requires minimum training and time. It also avoids the problems caused by variations in the lighting condition and/or the color of the fruit. To evaluate the robustness and accuracy of the proposed segmentation method, tests were conducted for 300 'Delicious' apples using three training samples with different color characteristics (i.e., orange, stripe, and dark red) and their combination. The segmentation error varied from 3% to 25% for the fixed SVM, while the adjustable SVM achieved consistent and accurate results for each training set, with the segmentation error of less than 2%. The proposed method provides an effective and robust segmentation means for sorting and grading apples in a multi-channel color space, and it can be easily adapted for other imaging-based agricultural applications.
A Model for the Electrical Degradation of Metal Microcontacts During Many-Cycle Operation

A model for the electrical degradation of MEMS switch metal microcontacts under many-cycle operation is presented. This model utilizes an asperity-based description of contacts and a general model for the degradation evolution. Calculations of switch resistance using this model predict a resistance evolution that shows good qualitative agreement with measurements. Implications of this model are discussed.Copyright © 2004 by ASME
OPEN-LOOP WORST-CASE IDENTIFICATION OF NON SCHUR PLANTS

Abstract This paper presents an LMI based algorithm for deterministic worst–case identification of non Schur plants in an open-loop setting. Contrary to other approaches dealing with this problem, the proposed technique does not require prior knowledge of a stabilizing controller. The main result of the paper shows that, as the information is completed, i.e. in the limit when the number of samples tends to infinity and the noise level tends to zero, the identified model converges, in the l 2 –induced topology, to the actual plant. Additional results include an algorithm outlining how to use the results of finite–lenght experiments to synthesize stabilizing controllers.
Metabolism-Independent Sugar Effects on Gene Transcription: The Role of 3-O-Methylglucose†

Glucose effects on cellular functions such as gene expression require, in general, glucose metabolism at least to glucose-6-phosphate (G-6-P). However, the example of thioredoxin-interacting protein (TXNIP), a glucose-regulated gene involved in the cellular redox state and pancreatic beta cell apoptosis, demonstrates that this rule may not always apply. We found that aside form glucose, the nonmetabolizable sugars 2-deoxyglucose, which is still converted to G-6-P as well as 3-O-methylglucose (3-MG), which cannot be phosphorylated by glucokinase, stimulate TXNIP expression. In contrast, incubation of INS-1 beta cells with equimolar amounts (25 mM) of l-glucose or mannitol had no effect on TXNIP expression as measured by real-time RT-PCR, eliminating the possibility of an osmotic effect. Also, glucose uptake into the cell is critical because phloretin, an inhibitor of glucose transporter 2, blunted the glucose effects. Moreover, the 3-MG effect was not restricted to a cell line and was observed in 293 cells and primary human islets. Incubation of INS-1 cells with 30mM mannoheptulose, an inhibitor of glucose metabolism, blunted all glucose-induced gene expression but left the 3-MG effects unaltered. Using transient transfection studies and deletion constructs of the human TXNIP promoter, we found that the effects of glucose and 3-MG were dependent on the same region of the TXNIP promoter containing an E-box repeat carbohydrate response element (ChoRE). Thus, these findings provide the first evidence for regulation of gene expression by 3-MG, which is independent of glucose metabolism and suggest that glucose and 3-MG regulate transcription by two distinct pathways converging at a common ChoRE.
Impedance boundary method of moments for efficient analysis of lossy and leaky planar optical waveguide structures

An extension of the impedance boundary method of moments (IBMOM) which enables determination of the propagation characteristics of lossy and leaky planar dielectric waveguides is demonstrated. The use of extended impedance boundary conditions to facilitate the analysis of waveguiding structures with large stepwise changes in refractive index, such as ARROW structures, is discussed. Numerical results show excellent agreement between previously published data and those generated using the complex version of the IBMOM.
coaster: Teaching Computer Graphics Incrementally (Abstract Only)

coaster is a project that teaches a semester-long introductory computer graphics class by means of ten programming assignments. The assignments are incremental - each one building on the previous ones - and ultimately require implementation of most of the course content in the final one: a first-person rollercoaster simulation. Briefly described, the assignments (and their course contents) are: circles ("warmup", 2D graphics, applying trigonometry),wire track (3D graphics, parametric curves),wire car (meshes),"hedgehog" car (face and vertex normals),shaded car (lighting models and vertex shaders),shaded track (extrusion, model transforms),surfaces (Bezier surfaces, height maps),first person (viewing transforms, animation, splines),dynamics (physics-based modeling), andtextures (textures, pixel shaders).There is also an eleventh project of the student's own (approved) design. Students are provided with template code for the first ten programming assignments. The languages used are C++ on the CPU and GLSL on the GPU. Students are presumed to have access to OpenGL/GLSL 3.3/3.30 and the GLUT and GLEW libraries.Both undergraduate and graduate students take the class. and it has been presented twice at Washington State University, both times with about half of the students on a remote campus receiving it as a live telecourse. Student response has been very positive.The goal of this lightning talk is to elicit interest from the computer graphics teaching community in making coaster systematically available to other universities by providing source code and training to instructors.
Participation of Gene Expression in the Protection against Amyloid β‐Peptide Toxicity by the β‐Amyloid Precursor Proteina

The amyloid beta-peptide (A beta) is a toxic derivative of the beta-amyloid precursor protein. Alternative processing of this precursor also yields large soluble forms (APPSs) which are secreted from many cell types. These APPSs have neuritogenic and neuroprotective activities; indeed, APPSs can protect primary neurons from the toxicity of A beta itself. To begin to explore the regulation of gene expression by APPS, we have focused on the NF-kappa B transcription factor family. NF-kappa B is induced by conditions of stress, including cellular oxidation. We report that NF-kappa B can also be induced by APPS. Furthermore, we effected direct activation of NF-kappa B through disinhibition using antisense oligonucleotide technology. This means of activating NF-kappa B resulted in protection of neuroblastoma cells from the toxicity of a calcium ionophore and protection of primary hippocampal neurons from the toxicity of A beta. Together, these data suggest that NF-kappa B may exist as a common agent inducing a neuroprotective pattern of gene expression in response to either trophic cytokines or stress itself.
Naturalistic evaluation of suicidal ideation: Variability and relation to attempt status

Suicidal ideation has been thought to have a relatively stable course across weeks and months. However, daily changes in levels of ideation have not been adequately examined despite the importance of potential variability clinically and conceptually. For example, it has been suggested that variability in suicidal ideation may become less closely tied to variability in other mood symptoms (e.g., depression, hopelessness) among individuals with multiple suicide attempts. The present report had two related goals: (1) to prospectively evaluate suicidal ideation and related mood symptoms, and (2) to determine whether suicide attempt status predicted a decreased association between ideation and other mood symptoms. Non-clinical participants (N=108) with varying levels of suicidal ideation and number of previous suicide attempts completed the beck hopelessness scale (BHS), beck depression inventory (BDI), and suicide probability scale (SPS) every day for 4 weeks. Findings suggested considerable variability in suicidal ideation, especially for multiple attempters. Multiple attempt status predicted a decreased association between suicidal ideation and depression, although the results were only marginally significant. These findings have implications for conceptual models of suicide risk as well as assessment and treatment of suicidal individuals.
Defining electromechanical dissociation: morphologic presentation

Electromechanical dissociation (EMD) is inconsistently defined in the literature. Our definition is the presence of discernible electrical complexes (excluding ventricular tachycardia and ventricular fibrillation) and the absence of palpable pulses. It has been noted that EMD may present with a variety of morphological complexes. It was the purpose of this study to categorize the electrical morphologic characteristics of patients presenting in EMD and to correlate morphology with patient outcome and response to therapy. From the 6-year period, January 1st, 1980 to December 31st, 1985, 503 evaluable adult patients presented to an urban paramedic system in non-traumatic, non-poisoned, cardiorespiratory arrest and were determined to be in EMD. The rhythm strips obtained from paramedics on all patients were retrospectively reviewed and were arbitrarily categorized in the following manner: Group 1, normal QRS width, isoelectric ST and normal appearing T-waves; Group 2A, atrial activity, widened QRS width (>0.12 ms) or abnormal ST and/or T-waves (ST depression, elevation, slurring or T-wave inversion); Group 2B, same as Group 2A but without atrial activity; Group 3, essentially monophasic, slurred RST complexes. The respective initial distribution was Group 1, 147 (29%); Group 2A, 248 (49%); Group 2B, 60 (12%); Group 3, 48 (10%). The relative frequency of morphologies preceding the attainment of a pulse was as follows: Group 1, 30 (24%); Group 2A, 82 (65%); Group 2B, 8 (6%); Group 3,6 (5%) (P ⩽ 0.01 with no significant difference between Group 2B and 3). The morphological frequency of successfully resuscitated patients prior to admission to an Emergency Department was as follows: Group 1, 36 (51%); Group 2A, 34 (49%); Group 2B, 0 (0%); Group 3, 0 (0%) (P ⩽ 0.01 when comparing either Group 1 or 2A to either Group 2B or 3). The relative frequency of patients saved were as follows: Group 1, 8 (5O%); Group 2A, 8 (50%); Group 2B, O (O%); Group 3, O (O%) (P ⩽ 0.01 when comparing either Group 1 or 2A to either Group 2B or 3). We conclude that EMD patients presented in at least four different morphological groups and that morphology is related to outcome.
A new fluorescent method for the demonstration of macromolecular aldehydes.

The fluorochrome, p-hydrazinoacridine (HA), is used to stain selectively natural macromolecular aldehydes as occur in elastic tissue as well as periodic acid (oxidized) or hydrochloric acid (hydrolyzed) engendered polyaldehydes (e.g., respectively of glycogen, mucosubstances and deoxyribonucleic acid). The reaction is independent of SO2 required in Schiff-type reactions. The mechanism of the staining reaction is presumably via the formation of fluorescent hydrazones from aldehyde condensation with HA. Aldehyde blocking agents, i.e., thiosemicarbazide and sodium borohydride, block the staining reactions with HA. In view of the controversy surrounding the mechanism of Schiff-type reactions and the lack of an adequate explanation for the affinity of miscellaneous fluorochromes for elastic tissue, p-hydrazinoacridine appears to be an ideal reagent, combining a simple staining procedure, excellent histological results and a straightforward mechanism for its selectivity.
Parental Depressive Symptoms and Children's School-Readiness: The Indirect Effect of Household Chaos

The relationship between parental depressive symptoms and children’s school-readiness has been well-established. However, contextual factors that may transmit the negative influence of parents’ depressive symptoms on children has less been studied. The current study examined household chaos, the level of crowdedness, disorganization, noise, and lack of routine at home as a mediating factor between parental depressive symptoms and children’s school-readiness. The data came from 444 preschool-aged children (36–70 months old). Parents and teachers reported on children’s socio-emotional development and children were directly assessed on literacy, math, and behavioral self-regulation. Structural equation modeling was used to test the indirect association, using the bootstrapping technique. Results revealed that parents’ depressive symptoms were significantly associated with their report of household chaos, which in turn was significantly related with children’s cognitive skills, mother-reported socio-emotional development, and behavioral self-regulation. Test of indirect effects showed that household chaos had significant indirect effect only between parental depressive symptoms and mother-reported social skills. The negative association between depressive symptoms and child outcomes were statistically significant regardless of the level of household chaos. The results of the study reveal that parents who have depressive symptoms may elicit more chaotic home environments, which affects their children’s socio-emotional development.
Chemical studies on the isolated collagen-like and globular fragments of complement component C1q comparative studies on bovine and human C1q

Abstract Both the collagen-like and the globular fragments of a subcomponent C1q of the first component of bovine and human complement were highly purified by enzymic digestion followed by gel filtration. Analyses by polyacrylamide gel electrophoresis showed that the former was composed of covalently linked peptide chains with an average molecular weight of 14 000, and that the latter was composed of three non-covalently linked peptide chains each having a molecular weight of approximately 15000. Great similarities between amino acid compositions of the globular fragments and some similarities between those of the collagen-like fragments were found. Moreover, great similarities of amino acid compositions were found among three non-covalently linked chains of each globular fragment as well as between the corresponding chains of both globular fragments. These results suggested that both the collagen-like and the globular domains on the C1q molecule remained highly conserved in its evolution.
High-dose isoproterenol testing for diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy: is there a role?

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an important cause of sudden death in young adults.1 Since Marcus and Fontaine’s initial report of a series of 24 patients with this condition in 1982 remarkable progress has been made in the understanding of all aspects of this disease.2 These advancements include improved understanding of (1) the natural history of ARVD/C, (2) optimal approaches for diagnosis, (3) the genetic basis of this condition, (4) the fundamental pathophysiologic mechanisms of ARVD/C, (5) the link between ARVD and exercise, and (6) sudden death prevention.1–6 Although far more work remains, the degree of scientific progress is remarkable. Article see p 590 In the present issue of Circulation: Arrhythmia and Electrophysiology , Denis et al7 report the results of their investigation into the role of high-dose isoproterenol infusions in the diagnosis of ARVD/C. A total of 412 consecutive patients (52% men; 42±16 years) referred for evaluation of premature ventricular contractions (PVCs) or ARVD/C during a 13-year period of time was included in this report. Subjects in the first 10 years of this study were analyzed retrospectively, whereas subjects enrolled between 2010 and 2013 were prospectively included in this analysis and followed up to determine whether they met criteria for ARVD/C over time. Thirty five of these patients had been diagnosed with ARVD/C based on the revised 2010 Task Force Criteria (TFC) at the time of their initial evaluation.6 The isoproterenol infusion consisted of intravenous administration of high-dose (45 μg/min) isoproterenol for 3 minutes. A continuous ECG was recorded during and for ≤10 minutes after the infusion. The test was interpreted as being positive if polymorphic PVCs (>3 morphologies) and ≥1 couplet were observed or if sustained or nonsustained monomorphic or polymorphic ventricular tachycardia (VT) with predominantly left bundle branch …
Syncope and conduction disturbances following sublingual nifedipine for hypertension

We present a case of a 79-year-old woman with periods of syncope, complete heart block (CHB), and ventricular standstill during periods of increased vagal tone following sublingual nifedipine for hypertension. The syncopal episodes were associated with periods of elevated vagal tone (micturition and vomiting) with one monitored episode showing a clear time course of emesis; CHB then ensued, progressing to ventricular standstill with loss of consciousness that resolved over several minutes. Although nifedipine is not thought to affect conduction at current clinical dosages, it seems likely that the additive effects of nifedipine and elevated vagal tone produced the observed conduction abnormalities. This is the first case report of nifedipine administration followed by syncope and conduction disturbances.
Quantitative test of the single-mode theory of optical bistability

Abstract The role of the transverse structure of the intracavity field in absorptive optical bistability is investigated for two-level atoms contained in a standing-wave cavity formed by spherical mirrors. Two cavity geometries are employed and differ in that one is confocal and hence degenerate with respect to transverse modes while the second is nonconfocal and closely approximates a single-mode resonator. For a wide range of atomic cooperativity, a comparison of the measured turning points of the hysteresis cycle is made with the predictions of the single-transverse-mode theory of absorptive bistability. This comparison yields absolute agreement for the two geometries to within the experimental uncertainties of approximately 10%.
Elementary School Principals' Learning-Centered Leadership and Educational Outcomes: Implications for Principals' Professional Development

This article arises from research in one school district (utilizing the Vanderbilt Assessment of Leadership in Education, VAL-ED) into the relationships among the perceptions of elementary school leaders of their learning-centered leadership, and student achievement on state-mandated tests of reading in Virginia. Beyond the percentage of students receiving free/reduced lunch, two core components of learning-centered leadership (“rigorous curriculum,” and, to a lesser extent, “performance accountability”) significantly improved the hierarchical multiple linear regressions of core components on reading scores. This study supports the professional development of principals based on the assessment of their learning-centered leadership behaviors.
The early diagnosis of carcinoma of the large intestine

Abstract The earliest ascertainable clues and symptoms of carcinoma of the colon and rectum have been considered, and factors aiding in an early and positive diagnosis have been reiterated. The most common initial symptoms of malignant growths of the right side of the colon are pain, palpable tumor and indefinite dyspepsia. Lesions in the transverse colon manifest themselves first by pain, obstructive attacks and developing or increasing constipation. Carcinoma of the descending colon and sigmoid is manifested first by increasing constipation or obstruction, pain, rectal bleeding and diarrhea. Carcinoma of the rectosigmoid and rectum is suggested by a change in bowel habit, either constipation or diarrhea, and rectal bleeding. The diagnosis of malignant lesions of the colon is rendered certain by roentgenographic examination. The presence of lesions in the sigmoid or below it may be proved by proctoscopic and digital examination of the rectum.
Comment on Baksu et al.: The effect of mode of delivery on postpartum sexual functioning in primiparous women

Dear Editor, Baksu et al. report the relationship between the method/ mode of delivery and various aspects of postpartum sexual function in Turkish women [1]. This study was primarily designed to evaluate the mode of vaginal delivery vs cesarian delivery on postpartum sexual function. This methodology was, however, overlooked in the results and conclusions, which concluded that mediolateral episiotomy was the prime factor affecting the postpartum sexual functioning in these women in comparison to cesarian delivery. This study was primarily not comparing mediolateral episiotomy and its repair methods vs any other types of episiotomy (median, J-shaped). This paper did not compare groups of women with vaginal births with or without episiotomy. It was designed to compare sexual health after vaginal births vs cesarian section to begin with. There is no comment on those women who had vaginal delivery without episiotomy and those women who had assisted vaginal delivery using vacuum or forceps delivery. The comparison of mode of delivery—vaginal birth with or without episiotomy to cesarian section delivery—is not very clear in this paper. It is apparent that more needs to be done to compare the types of episiotomy and methods of repairs before concluding that mediolateral episiotomy causes significant effect on postpartum sexual functioning. It cannot be assumed that vaginal birth affects postpartum sexual function in comparison to cesarian delivery. The sexual health of women with vaginal births without episiotomy or different types of episiotomy/instrumental deliveries needs to be addressed before drawing this final conclusion.
Fracture mechanics and cavitation in rubber-like solids

Conditions for propagation of a pressurized crack within a rubber-like solid are derived in terms of the elastic properties of rubber, the fracture energyGc and the initial radiusro of the crack. A previously proposed criterion, that the critical internal pressurePc for crack growth is given by 5E/6, whereE is the tensile (Young) modulus of elasticity, is shown to be inadequate both for small cracks, when the stiffening of rubber at high strains must be taken into account, and for large cracks, when the critical degree of inflation is so small that the assumptions leading toPc=5E/6 do not apply. However, this simple criterion is found to remain a useful guide for cracks having initial radii lying in an intermediate range, such thatroE/Gc lies between about 0.0005 and 1. For representative rubber-like solids, this corresponds to the rangero=0.5 μm to 1 mm.
Proteolytic Processing of Caenorhabditis elegansSQT-1 Cuticle Collagen Is Inhibited in Right Roller Mutants whereas Cross-linking Is Inhibited in Left Roller Mutants

The sqt-1 gene encodes a C. elegans cuticle collagen that when defective can cause dramatic alterations of organismal morphology. Specific antisera were used to examine the assembly of wild-type and mutant SQT-1 in the cuticle. Wild-type SQT-1 chains associate into dimer, tetramer, and higher oligomers that are cross-linked by non-reducible, presumably tyrosine-derived, covalent bonds. The SQT-1 pattern differs from the bulk of cuticle collagens which are found in trimer and larger forms.sqt-1 mutations that cause left-handed helical twisting of animals remove a conserved carboxyl-domain cysteine and inhibit formation of these non-reducible bonds. SQT-1 monomers accumulate and novel trimer-sized products form. A conserved tyrosine immediately adjacent to the affected cysteine suggests that disulfide bond formation is required for this tyrosine to form a cross-link.sqt-1 mutations that cause right-handed helical twisting affect conserved arginines in a predicted cleavage site for a subtilisin-like protease. These mutant SQT-1 molecules retain residues on the amino side of the predicted cleavage site and are larger than wild-type by the amount expected if cleavage failed to occur. The conservation of this site in all nematode cuticle collagens indicates that they are all synthesized as procollagens that are processed by subtilisin-like proteases.
Test of a model of organizational contributors to product development team effectiveness

Abstract This study tests a model of product development team effectiveness which was developed by Susman and Dean [Susman, G.I., Dean, J.W., 1992. Development of a model for predicting design for manufacturability effectiveness. In: Susman, G.I. (Ed.), Integrating Design and Manufacturing for Competitive Advantage. Oxford Univ. Press, New York, pp. 207–227.]. The model addresses two interrelated managerial issues. One concerns the use of integrative mechanisms to counterbalance the potentially negative effects of function-based differentiation, directly or indirectly through group process. The other concerns group process vs. codification/computerization as alternative means to process information as risk increases. This study addresses the first issue by testing the effect of a subset of integrative mechanisms on project outcomes, i.e., project focus, and the role of group process as partial mediator of this relationship. The second issue is addressed by testing for risk as positive moderator of the relationship between group process and project outcomes and as negative moderator of the relationship between codification/computerization and project outcomes. The results suggest that project focus is directly related to project outcomes, but group process does not mediate this relationship. Codification/computerization is not related to project outcomes. Risk does not positively moderate the group process–project outcomes relationship, but does negatively moderate the codification/computerization–project outcomes relationship.