cssi/SciSciGPT-SciSciNet huggingface dataset:
Tumor‐associated antigen 43‐9F is of prognostic value in squamous cell carcinoma of the lung. A retrospective immunohistochemical study

Background. Squamous cell lung carcinoma (SLC), the most frequent type of lung cancer, generally is treated surgically and its prognosis is poor. The only current clinically useful prognostic criterion is lymph node staging (TNM classification). Expression of a novel tumor-associated carbohydrate epitope Galβ1–3[Fucαl-4]GlcNAcβ1-4[Fucα1–3]GlcNAcβ1–3Galsl-4Glc identified by the 43-9F monoclonal antibody (MoAb) is associated with the growth pattern of SLC cell lines in athymic mice and in vitro. This implies that the 43-9F epitope may be related to tumor progression in patients with SLC and that, as such, it could be of prognostic value. Methods. Primary tumor specimens from 231 patients with lung carcinoma (130 with SLC, 64 with adenocarcinoma, 10 with small cell carcinoma, 16 with large cell carcinoma, and 11 with adenosquamous carcinoma) were examined by immunohistochemical studies on formalin-fixed, paraffin-embedded tissue samples for immunoreactivity with an MoAb to the 43-9F antigen. Univariate and step-wise Cox regression analyses were used to compare survival time by histopathologic diagnosis, smoker status, TNM classification, and type of surgical treatment. Results and Conclusions. Patients with 43–91: epitope-positive SLC tumors had a significantly (P < 0.01) better prognosis than patients with epitope-negative tumors. In contrast, no association was seen between 43-9F epitope expression and survival time for patients with lung adenocarcinomas. Further, the prognostic value of 43-9F expression in SLC was found to be superior to the N-classification with the added advantage that it requires access only to primary tumor tissue and thus is available before therapy. Cancer 1992; 70:1867–1872.
Computational Study of Roughness-Induced Boundary-Layer Noise

As a first step toward predicting rough-wall boundary-layer noise, the sound radiated from a single hemispherical roughness element and a pair of roughness elements in a turbulent boundary layer atRe 7500 is investigated. The roughness height is 3.6%of the boundary-layer thickness, or 95wall units. The flowfield is obtained from large-eddy simulation, and the results are validated against experimental measurements. Acoustic calculations are performed based on the Curle–Powell integral solution to the Lighthill equation for an acoustically compact hemisphere. The sound radiation is dominated by unsteady drag dipoles and their images in the wall. It is found that the spanwise dipole, which has been overlooked in previous studies of roughness noise, is of larger or similar strength compared with the streamwise dipole, and the viscous contribution to the drag dipoles is negligible in comparison with the pressure contribution. Important flow features contributing to sound radiation are identified by examining the unsteady surface-pressure field and the surrounding flow structures. Pressure fluctuations are strongest on the upstream part of the hemispheric surface near the base due to impingement of incoming turbulent eddies and their interactionwith horseshoe vortices. On the back surface of the hemisphere, pressurefluctuations are relativelyweak, indicating that shear-layer separation and vortex shedding do not produce significant self-noise from the hemisphere. In the casewith two hemispheres, thewake of the upstreamhemisphere is found to significantly enhance sound radiation from the downstream hemisphere, particularly in the streamwise direction and at high frequencies.
Switched Linear Systems: Stability and the Convergence of Random Products

In this paper we provide conditions for the stability of discrete time switched linear systems. We accomplish this by calculating the mean and covariance of the set of matrices obtained by using all possible switching sequences. The theory of switched linear systems has received con- siderable attention in the systems theory literature in the last two decades. However, for discrete time switched systems the literature is much older going back to at least the early 1960's with the publication of the paper of Furstenberg and Kesten in the area of products of random matrices, or, if you like, the random products of matrices. The way that we have approached this problem is to consider the switched linear system as evolving on a partially ordered network that is, in fact, a tree. This allows us to make use of the developments of 50 years of study on random products that exist in the statistics literature. 1. Introduction. The theory of switched linear systems has received consider- able attention in the systems theory literature in the last two decades and there is a wealth of solid results concerning the stability and stabilizability of such systems. A recent survey by Lin and Antsaklis, (14), gives a rather complete overview of the field. The main theorem cited there on stability for discrete time switched linear sys- tems, (their Theorem 6, (13)), requires that 2 n matrix norms must be calculated. In this paper we give a simpler calculation but one that will only hold for "almost all" (5) switching sequences. An excellent and readable source for the general theory of switched linear systems is the monograph by Liberzon, (12). In his book the primary focus is on continuous dynamics but the concepts are much the same. However, for discrete time switched systems the literature is much older than the systems theory literature, going back to at least the early 1960's with the publication of the papers of Furstenberg and Kesten, (9, 10), in the area of products of random matrices, or, if you like, the random products of matrices. In the statistical literature on random products "almost all" is the usual condition. We approach the problem in the following way. We study the switched linear system as evolving on a partially ordered network that is in fact a tree. This allows us to make use of the developments of 50 years of study on random products that exist in the statistics literature.
70 MHz surface-acoustic-wave resonator notch filter

A 70 MHz notch filter employing a surface-acoustic-wave resonator in a hybrid-coil circuit to produce a notch depth of 50 dB has been developed. The notch frequency is tunable over a 40 kHz range and the passband attenuation is approximately 7 dB.
Issues of Aging and Geriatric Medicine: Relevance to Cancer Treatment and Hematopoietic Reconstitution

Abstract Aging is not a disease. Nevertheless, diseases, including most malignancies, increase in frequency with advancing age. Although there are many reasons why this might be the case, perhaps most important is that it takes time to progress through the many steps of carcinogenesis and growth to reach a threshold for diagnosis. Other factors, including accumulated nonlethal damage to DNA (eg, by free radicals), increased proinflammatory factors, and age-associated declines in DNA repair and immune competence, are to some degree important. The median age for all cancer is approximately 70 years and will become even older over the next several decades. Myelodysplasia and hematologic malignancies, including lymphoma, myeloma, and leukemia, can be effectively treated in older age groups, but advanced age presents a number of additional challenges. With appropriate pretreatment assessment of organ reserve, physical performance, and cognitive function, individualized (tailored) therapy may ultimately prove to offer the greatest chance for successful outcomes. Such assessment would also identify those who are likely to benefit from more aggressive treatments, including bone marrow or stem cell transplantation.
The Advantages of Skim-Milk Agar for the Determination of the Sanitary Quality of Market Milk

Summary The fermentable carbohydrates and other milk constituents in skim-milk agar make it a desirable medium to use in the routine control of market milk and other dairy products. The skim-milk agar counts on 618 samples of pasteurized milk were, on the average, two to four times as large as the corresponding counts on standard agar. The counts on 137 samples of raw milk were only slightly higher. The colonies were much larger and consequently could be counted with greater ease and rapidity. The slight opacity of the medium prevents the glare often experienced when artificial lighting devices are used. Acid-producing and protein-digesting types of bacteria can be differentiated on this medium. It supports the growth of bacteria responsible for mastitis in cows. It is simple and easy to make and no more expensive than the present standard agar.
Malignant Degeneration of Pleomorphic Adenoma-Clinical Implications

Abstract Introduction: The incidence of carcinoma arising in a pleomorphic adenoma is reportedly between 1.4% and 6.3%. Malignant degeneration is often associated with a prolonged history of untreated or recurrent pleomorphic adenoma. Materials and Methods: Two patients with malignant parotid carcinoma that arose from benign pleomorphic adenoma are reviewed. Results: Both patients exhibited a prolonged history of pleomorphic adenoma apparently persistent after initial inadequate surgery. Surgeries were performed 37 and 12 years before development of malignancy. Discussion: The phenomenon of malignant carcinoma arising from benign pleomorphic adenoma is an important issue. The occurrence of these malignant carcinomas emphasizes that aggressive treatment of primary and recurrent mixed tumors is necessary.
EFFECT OF ALDOSTERONE ANTAGONISM ON CARDIAC FUNCTION AND EXERCISE CAPACITY IS INDEPENDENT OF NYHA CLASSIFICATION: A META-ANALYSIS OF 1460 PATIENTS IN RANDOMIZED CONTROLLED TRIALS

Current guidelines only recommend the use of mineralocorticoid receptor antagonists (MRA) in NYHA class >III. We used a metaanalysis to quantify the improvement in EF with MRA therapy and to clarify whether this benefit is dependent on baseline NYHA. A MEDLINE search and examination of reference
Discipline and Devolution: Constructions of Poverty, Race, and Criminality in the Politics of Rural Prison Development

Abstract: The soaring expansion of the US prison population is transforming the geographies of both urban and rural landscapes. As the trend in mass incarceration persists, depressed rural spaces are increasingly associated with rising prison development and the increasing criminalization of rural communities of disadvantage. Drawing on in-depth archival and interview research in rural communities in the Northwestern states of Idaho and Montana, this paper explores how cultural productions of poverty and exclusion intersect with rural prison development. I examine how representations of poverty and criminality are entangled with processes of economic restructuring and the localization of economic development and social welfare. I explore the ways in which the rural prison geography of the Northwest is linked to the material and discursive construction of those in poverty and how these narratives are produced through local relations of race, ethnicity, and class. I suggest that the mobilization of these constructions legitimates rural prison expansion, increasingly punitive social and criminal justice policies, and the retrenchment of racialized and classed inequality. Further, I argue that these discursive imaginations of the poor work to obscure the central dynamics producing poverty under the neoliberal restructuring of rural economies and governance.
Stalled Folding Mutants in the Triple β-Helix Domain of the Phage P22 Tailspike Adhesin

The trimeric bacteriophage P22 tailspike adhesin exhibits a domain in which three extended strands intertwine, forming a single turn of a triple β-helix. This domain contains a single hydrophobic core composed of residues contributed by each of the three sister polypeptide chains. The triple β-helix functions as a molecular clamp, increasing the stability of this elongated structural protein. During folding of the tailspike protein, the last precursor before the native state is a partially folded trimeric intermediate called the protrimer. The transition from the protrimer to the native state results in a structure that is resistant to denaturation by heat, chemical denaturants, and proteases. Random mutations were made in the region encoding residues 540–548, where the sister chains begin to wrap around each other. From a set of 26 unique single amino acid substitutions, we characterized mutations at G546, N547, and I548 that retarded or blocked the protrimer to native trimer transition. In contrast, many non-conservative substitutions were tolerated at residues 540–544. Sucrose gradient analysis showed that protrimer-like mutants had reduced sedimentation, 8.0 S to 8.3 S versus 9.3 S for the native trimer. Mutants affected in the protrimer to native trimer transition were also destabilized in their native state. These data suggest that the folding of the triple β-helix domain drives transition of the protrimer to the native state and is accompanied by a major rearrangement of polypeptide chains.
The effects of feature necessity and extrinsicity on gradedness of category membership and class inclusion relations

Two theories of differences among natural language categories in graded membership and strength of class inclusion are contrasted. The two sets of hypotheses tested were: (1) that categories represented by features which many people believe to be necessary would have less graded memberships, and stronger class inclusion, than those represented by features which few people believe to be necessary, and (2) that categories which people believe are represented primarily by intrinsic features (i.e. features that are true of an entity in isolation; see Barr & Caplan, 1987) would have less graded structures, and stronger class inclusion, than those which people believe are represented primarily by extrinsic features (i.e. features representing relations between an entity and other entities). The findings suggest that feature necessity and feature extrinsicity have independent effects on gradedness of category membership and on class inclusion.
Ferroelectric films as a Fashion Object for Polycrystalline Film Investigation

BaxSr1-xTiO3 (BST), PbZrxTi1-xO3 (PZT) and two layer PZT-BST films were prepared on Pt, Si(100) and Si(111) substrates by a sol-gel method. XRD analysis shows that the PZT films on the Si(111) substrates tended to be preferentially oriented in the (110) direction. The nondestructive readout of the state of ferroelectric polarization was investigated by three methods: the pyroelectric effect, the non-linearity of the capacitance and the field effect in MOS structures. It is shown that all three methods provide nondestructive readout, and the choice between them depends on the intended use.
Hypothalamic self stimulation and feeding: Different time functions ☆

Abstract Animals which fed to electrical stimulation of the hypothalamus also self stimulated at the same current level. However, there was minimal overlap between the train length that animals preferred in the self stimulation situation and that required to produce feeding. The evidence suggests that the rewarding properties of the stimulation decline as the apparent hunger builds up. The data are incompatible with an interpretation of the reinforcing properties of self stimulation being positively correlated with hunger, consummatory responses, or fixed action patterns.
Observational Validation of a Model of Ambulatory Teaching

Purpose: This study examines teaching by preceptors in a longitudinal, primary care clerkship for third year medical students. The authors compared observations from different points in the clerkship to determine the validity of a three-stage model (modeling, supervision, and consultation) based on their previous research. Methodology: Seven experienced preceptors were observed three times over the course of the year while teaching third-year medical students. A single observer recorded the teaching behaviors using an observation instrument containing 30 behaviors relevant to ambulatory teaching. The behaviors were categorized into five groups (Modeling, Supervision, Consultation, Validation, and General Teaching) for purposes of comparing their relative contribution to the proposed three-stage model. Results: Frequencies of teaching behaviors within the five categories were compared over the three observations. Modeling behaviors declined over the three time periods (p<.02), while Validation increased from the first to the second observation (p<.02). The examining room was the predominate location for teaching. Location differences in favor of the examining room were statistically significant for Modeling, Supervision, and Validation teaching behaviors. Conclusions: There was a shift in teaching behavior over time in a longitudinal clerkship. The decrease in Modeling behaviors coupled with the increase in Validation behaviors supports the proposed model of teaching. The failure to identify change in supervision behaviors may be due to the long time interval between observations. Additional observations at more frequent intervals are needed to clarify this part of the hypothesis.
Receptive Fields in the Rat Piriform Cortex

Current models of odor discrimination in mammals involve molecular feature detection by a large family of diverse olfactory receptors, refinement of molecular feature extraction through precise projections of olfactory receptor neurons to the olfactory bulb to form an odor-specific spatial map of molecular features across glomerular layer, and synthesis of these features into odor objects within the piriform cortex. This review describes our recent work on odor and spatial receptive fields within the anterior piriform cortex and compares these fields with receptive fields of their primary afferent, olfactory bulb mitral/tufted cells. The results suggest that receptive fields in the piriform cortex are ensemble in nature, highly dynamic, and may contribute to odor discrimination and odor memory.
Inhibition of HIV-1 Replication by Amphotericin B Methyl Ester SELECTION FOR RESISTANT VARIANTS

Membrane cholesterol plays an important role in human immunodeficiency virus type 1 (HIV-1) particle production and infectivity. Here, we have investigated the target and mechanism of action of a cholesterol-binding compound, the polyene antifungal antibiotic amphotericin B methyl ester (AME). We found that AME potently inhibited the replication of a highly divergent panel of HIV-1 isolates in various T-cell lines and primary cells irrespective of clade or target cell tropism. The defects in HIV-1 replication caused by AME were due to profoundly impaired viral infectivity as well as a defect in viral particle production. To elucidate further the mechanism of action of AME, we selected for and characterized AME-resistant HIV-1 variants. Mutations responsible for AME resistance mapped to a highly conserved and functionally important endocytosis motif in the cytoplasmic tail of the transmembrane glycoprotein gp41. Interestingly, truncation of the gp41 cytoplasmic tail in the context of either HIV-1 or rhesus macaque simian immunodeficiency virus also conferred resistance to AME. The infectivity of HIV-1 virions bearing murine leukemia virus or vesicular stomatitis virus glycoproteins was unaffected by AME. Our data define the target and mechanism of action of AME and provide support for the concept that cholesterol-binding compounds should be pursued as antiretroviral drugs to disrupt HIV-1 replication.
Whole-Genome Transcriptional Profiling of Bradyrhizobium japonicum during Chemoautotrophic Growth

Bradyrhizobium japonicum is a facultative chemoautotroph capable of utilizing hydrogen gas as an electron donor in a respiratory chain terminated by oxygen to provide energy for cellular processes and carbon dioxide assimilation via a reductive pentose phosphate pathway. A transcriptomic analysis of B. japonicum cultured chemoautotrophically identified 1,485 transcripts, representing 17.5% of the genome, as differentially expressed when compared to heterotrophic cultures. Genetic determinants required for hydrogen utilization and carbon fixation, including the uptake hydrogenase system and components of the Calvin-Benson-Bassham cycle, were strongly induced in chemoautotrophically cultured cells. A putative isocitrate lyase (aceA; blr2455) was among the most strongly upregulated genes, suggesting a role for the glyoxylate cycle during chemoautotrophic growth. Addition of arabinose to chemoautotrophic cultures of B. japonicum did not significantly alter transcript profiles. Furthermore, a subset of nitrogen fixation genes was moderately induced during chemoautotrophic growth. In order to specifically address the role of isocitrate lyase and nitrogenase in chemoautotrophic growth, we cultured aceA, nifD, and nifH mutants under chemoautotrophic conditions. Growth of each mutant was similar to that of the wild type, indicating that the glyoxylate bypass and nitrogenase activity are not essential components of chemoautotrophy in B. japonicum.
The Effect of Parents’ Attitudes toward Divorce on Offspring’s Attitudes Gender and Parental Divorce as Mediating Factors

This study addresses three questions: (a) What influence do parents’ attitudes toward divorce have on off spring’s attitudes? (b) How are offspring’s attitudes toward divorce influenced by parental divorce, and do the effects vary depending on the gender of the child? and (c) How do conditions surrounding parental divorce influence young adults’ attitudes? Results indicate that parents have the greatest influence on offspring during the late teen years. Fathers have more influence on sons’ attitudes than mothers; the gender of parent has no effect on the influence of parents’ attitudes on daughters’ attitudes. In contrast to prior research, this study finds that parental divorce continues to influence offspring’s views of divorce after controlling for parents’attitudes only for daughters, not for sons. Postdivorce conflict and diminished closeness to father following the divorce have different effects on sons’ and daughters’ attitudes.
Switching activity estimation of VLSI circuits using Bayesian networks

Switching activity estimation is an important aspect of power estimation at circuit level. Switching activity in a node is temporally correlated with its previous value and is spatially correlated with other nodes in the circuit. It is important to capture the effects of such correlations while estimating the switching activity of a circuit. In this paper, we propose a new switching probability model for combinational circuits that uses a logic-induced directed-acyclic graph (LIDAG) and prove that such a graph corresponds to a Bayesian network (BN), which is guaranteed to map all the dependencies inherent in the circuit. BNs can be used to effectively model complex conditional dependencies over a set of random variables. The BN inference schemes serve as a computational mechanism that transforms the LIDAG into a junction tree of cliques to allow for probability propagation by local message passing. The proposed approach is accurate and fast. Switching activity estimation of ISCAS and MCNC circuits with random and biased input streams yield high accuracy (average mean error=0.002) and low computational time (average elapsed time including CPU, memory access and I/O time for the benchmark circuits=3.93 s).
Cranial-base repair using endoscopic laser welding.

The field of endoscopic cranial-base surgery has undergone significant evolution in the past decade, fueled largely by advances in imaging and instrumentation. While the limits of these approaches have yet to be reached, difficulties in reconstructing the resultant defects have become significant obstacles. Successful reconstruction requires a technique that recapitulates the complex morphology of the cranial base while simultaneously withstanding the hydrostatic forces exerted by the cerebrospinal fluid compartment. Current strategies have evolved around the fundamental limitations of access in endoscopic approaches and thus represent a departure from the principles of surgical closure in an open field. In place of meticulous tissue apposition and watertight suture lines, surgeons are limited to multilayer grafting and the liberal application of relatively weak biologic glues, which often obscure the defect, thereby impairing the intraoperative assessment of the closure. These techniques may require prolonged nasal packing and lumbar drain placement to further support the repair in the immediate postoperative period. Despite these limitations, the low-pressure profile of cerebrospinal fluid coupled with the dense vascularity of the dura and mucosa allow for robust wound healing leading to successful closure in the vast majority of cases. The recent introduction of vascularized rotational flaps has further improved outcomes in several series. However, there remains an overall 10% failure rate, which may increase as skull-base approaches continue to expand. These problems have catalyzed a search for a repair method that can be applied endoscopically
A Digital BIST for Phase-Locked Loops

This paper presents a conceptual implementation of a jitter measurement circuit with several BIST (built-in self test) features for embedded phase-locked loops. We demonstrate a fully functional jitter measurement circuit capable of detecting cycle-to-cycle jitter. Proposed BIST logic provides additional information such as MAX jitter value, programmable threshold detection and most recent jitter result with low processing overhead.
A variability study of regional alveolar oxygen tension measurement in humans using hyperpolarized 3He MRI

Purpose A systematic study of the short-term and long-term variability of regional alveolar partial pressure of oxygen tension (pAO2) measurements using 3He magnetic resonance imaging was presented. Additionally, the repeatability of the average evaluated pAO2 was compared with that of the standard pulmonary function tests. Methods Pulmonary function test and pAO2 imaging were performed on 4 nonsmokers (1 M, 3 F, 56 ± 1.7 years) and 4 smokers (3 M, 1 F, 52 ± 7.5 years) during three visits over the course of 2 weeks. Two measurements were performed per visit. Variability of pAO2 was assessed using a mixed-effect model, with an intraclass correlation coefficient calculated for each group. The coefficient of variation of pAO2 over the 3-day period was also compared with the coefficient of variation of pulmonary function test results. Results Short-term regional variability based on intraclass correlation coefficient was 0.71 for nonsmokers, and 0.63 for smokers, with long-term variability significantly lower at 0.59 and 0.47, respectively. While the coefficient of variation of the average pAO2 was similar to the repeatability of the diffusing capacity of CO, it was significantly higher than that of Forced Vital Capacity (P = 0.02). Conclusion Short-term and long-term pAO2 variability differences were used as an indication of true physiological changes in order to measure technical reproducibility. Smokers show higher physiologic variability and less technical reproducibility. The suggested pAO2-imaging technique showed a reasonable regional repeatability in nonsmokers as well as the ability to detect differences between the two groups with similar reproducibility and superior discriminatory ability when compared with pulmonary function tests. Magn Reson Med 70:1557–1566, 2013. © 2013 Wiley Periodicals, Inc.
Microcapsules for Enhanced Cargo Retention and Diversity

P revention of undesired leakage of encapsulated materials prior to triggered release presents a technological challenge for the practical application of microcapsule technologies in agriculture, drug delivery, and cosmetics. A microfl uidic approach is reported to fabricate perfl uoropolyether (PFPE)-based microcapsules with a high core-shell ratio that show enhanced retention of encapsulated actives. For the PFPE capsules, less than 2% leakage of encapsulated model compounds, including Allura Red and CaCl 2 , over a four week trial period is observed. In addition, PFPE capsules allow cargo diversity by the fabrication of capsules with either a water-in-oil emulsion or an organic solvent as core. Capsules with a toluene-based core begin a sustained release of hydrophobic model encapsulants immediately upon immersion in an organic continuous phase. The major contribution on the release kinetics stems from the toluene in the core. Furthermore, degradable silica particles are incorporated to confer porosity and functionality to the otherwise chemically inert PFPE-based polymer shell. These results demonstrate the capability of PFPE capsules with large core‐shell ratios to retain diverse sets of cargo for extended periods and make them valuable for controlled release applications that require a low residual footprint of the shell material.
Pathogenesis of Y.enterocolitica and Y.pseudotuberculosis in Human Yersiniosis

Yersiniosis is a food-borne illness that has become more prevalent in recent years due to human transmission via the fecal-oral route and prevalence in farm animals. Yersiniosis is primarily caused by Yersinia enterocolitica and less frequently by Yersinia pseudotuberculosis. Infection is usually characterized by a self-limiting acute infection beginning in the intestine and spreading to the mesenteric lymph nodes. However, more serious infections and chronic conditions can also occur, particularly in immunocompromised individuals. Y. enterocolitica and Y. pseudotuberculosis are both heterogeneous organisms that vary considerably in their degrees of pathogenicity, although some generalizations can be ascribed to pathogenic variants. Adhesion molecules and a type III secretion system are critical for the establishment and progression of infection. Additionally, host innate and adaptive immune responses are both required for yersiniae clearance. Despite the ubiquity of enteric Yersinia species and their association as important causes of food poisoning world-wide, few national enteric pathogen surveillance programs include the yersiniae as notifiable pathogens. Moreover, no standard exists whereby identification and reporting systems can be effectively compared and global trends developed. This review discusses yersinial virulence factors, mechanisms of infection, and host responses in addition to the current state of surveillance, detection, and prevention of yersiniosis.
Morphological adaptations of the respiratory hindgut of a marine echiuran worm.

The echiuran worm Urechis caupo lives in U-shaped burrows in marine mudflats where levels of toxic hydrogen sulfide increase and water becomes hypoxic during low tide. Even in this low oxygen and high sulfide environment, the animal is capable of maintaining aerobic respiration. Gas exchange occures across both the body wall and hindgut. The hindgut functions as a type of water lung and is a thin walled, highly convoluted structure capable of considerable dilatation. It is rhythmically ventilated with water and its role as a respiratory organ becomes increasingly important as ambient pO2 drops. In the deflated hindgut light microscopy reveals a pseudostratified appearing innermost mucosal epithelium composed of columnar cells with nuclei at different levels. When the hindgut is fully inflated, ultrastructural studies show a simple columnar epithelium with the nuclei at the same level. Ultrastructurally, the free surface of the hindgut cells bears numerous microvilli and a few cilia. The lateral cell membranes are highly folded in the deflated hindgut, but these folds are not visible in the fully inflated hindgut. The cytoplasm contains osmiophilic bodies which show a partially lamellated pattern which may be sulfide oxidizing bodies involved in sulfide detoxification. In the fully inflated hindgut, the entire perimeter of the lumenal mucosa is covered by electron dense inclusions, whose exact fuction is unknown. The lack of structural information on the respiratory organ of this echiuran worm renders the interpretation of its morphological and histological features at the ultrastructural level difficult, although the present study has broadened our understanding of the structural adaptations of the hindgut as a respiratory organ. © 1992 Wiley-Liss, Inc.
A parametrically drive PLL lock detector

A parametrically driven PLL lock detector is presented. The lock detector is described by a time-varying linear differential equation derived from the PPL's nonlinear dynamics. The time-varying nature of this detector equation results from the fact that it is parametrically driven by the output of the PLL's quadrature detector. A lock decision is made by comparing a detector equation state to a user-specified threshold. Also, the detector produces a DC voltage which may be capable of driving a phase locked receiver's coherent AGC system. Finally, a laboratory experiment is described which demonstrate the feasibility of the detector concept. Use of the lock detector eliminates a class of problems associated with the simple phase quadrature lock detector, resulting from the fact that the quadrature detector can produce a DC component under false lock conditions. >
The Fatty Acid Composition of Porcine Spermatozoa Phospholipids

The fatty acid composition of three phospholipids of boar spermatozoa from 32 ejaculates was determined; choline phosphatide, ethanolamine phosphatide, and serine phosphatide were the phospholipids in which 19 fatty acids and two aldehydes were identified. Thin-layer and gas-liquid chromatography were employed for separation of phospholipids and determination of fatty acids. Major saturated fatty acids present were palmitic (16:0), stearic (18:0), and myristic (14:0). Palmitic and stearic acid were present in highest concentrations, ranging from 8 to 19% and 4 to 36%, respectively, in the three phosphatides. Unsaturated fatty acids predominated in the choline and ethanolamine phosphatides, while saturated acids predominated in the serine phosphatides. Docosapentaenoic acid (22:5w6) was the major unsaturated acid at a high of 38.6%. Docosahexaenoic acid (22:6) was somewhat less at 25.2%. Oleic acid (18:1w9), linoleic acid (I8:2w6), and arachidonic acid (20:4w6) were present in lesser quantities. The fatty acid composition of boar spermatozoa phospholipid has not been elucidated. Numerous studies have been conducted to determine the fatty acids present in the semen of various other species. Patton and Flipse (1961) reported that myristic, palmitic, and stearic acid accounted for over 80% of the fatty acids in bovine spermatozoa lipid. Dietz et al. (1963) reported the presence of several fatty acids in whole bull semen lipid; palmitic acid predominated. Pursel and Graham (1967) reported the presence of 11 fatty acids in bovine spermatozoa phospholipid; docosahexaenoic acid was the predominant acid in the choline phosphatide fraction. Ram semen phospholipid contains palmitic and arachidonic acid in large quantities (Gray, 1960). Hartree and Mann (1961) reported that ram semen contained six major fatty acids; palmitic and oleic acid were present in highest concentra
Activation of Latent Graves' Disease in Children Review of Possible Psychosomatic Mechanisms

In some children, psychological events have appeared to be important in the triggering of Graves' disease. This report examines the case histories of three children in whom the appearance of symptomatology of Graves' disease was associated with depression following the death of a loved one. An analysis of neuroendocrine and immunologie pathways suggests that depression, set off by bereavement, causes low levels of norepinephrine in the brain. The latter in turn may mediate an increase in ACTH and cortisol, leading to reductions in immune surveillance and resultant production of thyroid-stimulating immunoglobulins, hence the development of Graves' disease.
More is more: The benefits of dense sensor deployment

An ad-hoc sensor network is composed of sensing devices which can measure or detect features of their environment, communicate with one other and possibly with other devices that perform data fusion. One of the problems motivated by ad-hoc sensor networks is to position sensors in order to maximize coverage, or equivalently to minimize the number of sensors required to cover a given area.
Three-dimensional electromagnetic scattering from inhomogeneous objects by the hybrid moment and finite element method

The hybrid moment and finite element methods are used to obtain 3-D scattering and/or absorption from inhomogeneous, arbitrarily shaped objects. The surface of the object is approximated by triangles and the volume of the object is approximated by tetrahedrons. The electrical parameters are assumed constant in each tetrahedron. The Galerkin testing procedure is used. To avoid contaminations of spurious mode, a divergenceless vector basis function is used in finite elements. The calculated internal field and scattered field for a homogeneous sphere, a layered sphere, and a lossy prolate spheroid are compared with Mie series solutions and other numerical techniques. The accuracy and rate of convergence of the solution are discussed. >
Substructure Allocation in Recursive Interconnection Networks

In a multiuser message passing MIMD sys tem, substructure allocation is an important aspect of sys tem design. In this paper, we present four substructure al location algorithms for a multiuser WK-Recursive network. Two algorithms are bit-map based and two are tree based. The algorithms are compared using simulation.
The Generic Advertising Controversy: How Did We Get Here and Where Are We Going?

Since the 1980s, generic advertising programs for dozens of farm commodities have been entangled in a great deal of litigation. The author looks at the history of generic advertising policies, discusses why the litigation arose when it did, and argues that the current round of litigation is simply an inevitable outgrowth of fairly recent Supreme Court rulings on commercial speech. The author further examines some of the economic studies that have been performed. The author predicts an increase in generic advertising litigation based upon the degree of collectivization in an industry and urges economists to bring the controversy into their modeling.
APPLICATION OF INTERFACE TECHNOLOGY IN PROGRESSIVE FAILURE ANALYSIS OF COMPOSITE PANELS

A progressive failure analysis capability using interface technology is presented. The capability has been implemented in the COMET-AR finite element analysis code developed at the NASA Langley Research Center and is demonstrated on composite panels. The composite panels are analyzed for damage initiation and propagation from initial loading to final failure using a progressive failure analysis capability that includes both geometric and material nonlinearities. Progressive failure analyses are performed on conventional models and interface technology models of the composite panels. Analytical results and the computational effort of the analyses are compared for the conventional models and interface technology models. The analytical results predicted with the interface technology models are in good correlation with the analytical results using the conventional models, while significantly reducing the computational effort.
The Structure of Instantaneous Phase Resetting in a Neural Oscillator

In order to ultimately gain an understanding of the central pattern generators (CPG) involved in rhythmic motor activity such as locomotion and respiration it is necessary to understand the phase resetting behavior of the neural oscillators that comprise such circuits. In this study, we ignore action potential generation and instead focus on the underlying oscillations whose plateaus comprise the bursts and whose troughs comprise the interburst hyperpolarizations. We have examined the structure of phase resetting in neural oscillators. As an illustrative example, we will use Morris-Lecar oscillator, which, despite its simplicity, reproduces with sufficient accuracy the membrane potential envelope of a neural oscillator. The qualitative characterization of a limit cycle oscillator as a phase oscillator, a relaxation oscillator, or an intermediate determines the relationship between time elapsed (temporal phase) and distance traversed along the limit cycle (geometric phase). A mapping between geometric phase and temporal phase was found to provide insight into the shape of the phase resetting curve (PRC).
Comparative effectiveness of frame-based, frameless, and intraoperative magnetic resonance imaging-guided brain biopsy techniques.

Objective To compare the diagnostic yield and safety profiles of intraoperative magnetic resonance imaging (MRI)–guided needle brain biopsy with 2 traditional brain biopsy methods: frame-based and frameless stereotactic brain biopsy. Methods A retrospective analysis was performed of 288 consecutive needle brain biopsies in 277 patients undergoing stereotactic brain biopsy with any of the 3 biopsy methods at Brigham and Women’s Hospital from 2000–2008. Variables including age, sex, history of radiation and previous surgery, pathology results, complications, and postoperative length of hospital stay were analyzed. Results Over the course of 8 years, 288 brain biopsies were performed. Of these, 253 (87.8%) biopsies yielded positive diagnostic tissue. Young age ( Conclusions Frame-based, frameless stereotactic, and intraoperative MRI–guided brain needle biopsy techniques have comparable diagnostic yield for patients with no prior treatments (either radiation or surgery). Intraoperative MRI–guided brain biopsy is associated with fewer serious adverse events and shorter hospital stay.
Simulation of the human intracranial arterial tree

High-resolution unsteady three-dimensional flow simulations in large intracranial arterial networks of a healthy subject and a patient with hydrocephalus have been performed. The large size of the computational domains requires the use of thousands of computer processors and solution of the flow equations with approximately one billion degrees of freedom. We have developed and implemented a two-level domain decomposition method, and a new type of outflow boundary condition to control flow rates at tens of terminal vessels of the arterial network. In this paper, we demonstrate the flow patterns in the normal and abnormal intracranial arterial networks using patient-specific data.
The gating isomerization of neuromuscular acetylcholine receptors

Acetylcholine receptor-channels are allosteric proteins that isomerize (‘gate’) between conformations that have a low vs. high affinity for the transmitter and conductance for ions. In order to comprehend the mechanism by which the affinity and conductance changes are linked it is of value to know the magnitude, timing and distribution of energy flowing through the system. Knowing both the di- and unliganded gating equilibrium constants (E2 and E0) is a foundation for understanding the AChR gating mechanism and for engineering both the ligand and the protein to operate in predictable ways. In adult mouse neuromuscular receptors activated by acetylcholine, E2= 28 and E0≈ 6.5 × 10−7. At each (equivalent) transmitter binding site acetylcholine provides ∼5.2 kcal mol−1 to motivate the isomerization. The partial agonist choline provides ∼3.3 kcal mol−1. The relative time of a residue's gating energy change is revealed by the slope of its rate–equilibrium constant relationship. A map of this parameter suggests that energy propagates as a conformational cascade between the transmitter binding sites and the gate region. Although gating energy changes are widespread throughout the protein, some residues are particularly sensitive to perturbations. Several specific proposals for the structural events that comprise the gating conformational cascade are discussed.
Physical Activity Breaks and Facilities in US Secondary Schools

BACKGROUND Research on physical activity breaks and facilities (indoor and outdoor) in secondary schools is relatively limited.
Galaxy of news: an approach to visualizing and understanding expansive news landscapes

The Galaxy of News system embodies an approach to visualizing large quantities of independently authored pieces of information, in this case news stories. At the heart of this system is a powerful relationship construction engine that constructs an associative relation network to automatically build implicit links between related articles. To visualize these relationships, and hence the news information space, the Galaxy of News uses pyramidal structuring and visual presentation, semantic zooming and panning, animated visual cues that are dynamically constructed to illustrate relationships between articles, and fluid interaction in a three dimensional information space to browse and search through large databases of news articles. The result is a tool that allows people to quickly gain a broad understanding of a news base by providing an abstracted presentation that covers the entire information base, and through interaction, progressively refines the details of the information space. This research has been generalized into a model for news access and visualization to provide automatic construction of news information spaces and derivation of an interactive news experience.
School Predictors of Violent Criminality in Adulthood: Findings From a Nationally Representative Longitudinal Study

School-related problems such as poor academic performance, truancy, frequent suspensions, and grade repeating have been identified as risk factors for adolescent behavior problems. The purpose of the current study was to examine the effect of school-related factors on violent criminality in adulthood, based on data from the National Longitudinal Study on Adolescent Health. Logistic regression analyses indicated that behavioral variables (i.e., truancy, suspensions) and academic variables (i.e., grade retention and grades) significantly improved the prediction of criminal offending. The strongest predictor of violent criminal behavior in adulthood was repeating a grade at the secondary level. Practice implications are presented.
The substance of cultural evolution: Culturally framed systems of social organization

Models of cultural evolution need to address not only the organizational aspects of human societies, but also the complexity and structure of cultural idea systems that frame their systems of organization. These cultural idea systems determine a framework within which behaviors take place and provide mutually understood meanings for behavior from the perspective of both agent and recipient that are critical for the coherence of human systems of social organization.
On the influence of programming models on shared memory computer performance

Experiments are presented indicating that on shared-memory machines, programs written in the nonshared-memory programming model generally offer better performance, in addition to being more portable and scalable. The authors study the LU decomposition problem and a molecular dynamics simulation on three shared-memory machines with widely differing architectures, and analyze the results from three perspectives: performance, speedup, and scaling. >