cssi/SciSciGPT-SciSciNet huggingface dataset:
A loss in the family: Silence, memory, and narrative identity after bereavement

Grief theories have converged on the idea that the sharing of autobiographical memory narratives of loss and of the deceased person, especially within the family, is a major way to maintain and/or reconfigure a healthy sense of identity after a loss. In contrast, we examine unspoken memory—the withholding of socially sharing autobiographical memories about the loss and the departed family member—as a way to either conserve an existing narrative identity or assert a new narrative identity. Depending on its context and function, silence about memory can play either a positive or negative role in an individual griever's ongoing narrative identity, as well as in the larger family narrative in which the griever's identity is embedded.
The theory of Z-mode echoes

Abstract A new theory is proposed to explain the return of Z -mode echoes from the F -layer, The currently accepted theory postulates strong back scattering at the reflection layer, an assumption which cannot always be justified. The Z -mode can be reflected along the incident path with little or no need of back scattering, if the layers of reflection are nearly normal to the earth's magnetic field. The local horizontal electron density gradient of the ionosphere can. provide the required tilting of the reflecting layers. Numerical computations with existing observational data support the proposed mechanism.
Self Esteem, Academic Achievement, and Moral Development Among Adolescent Girls

Abstract Girls who play sports are known to display more self-confidence and tend to have a higher moral development. Using data on high school girls, we explore the effectiveness of competitive team sports on their self-confidence, use of drugs and alcohol, spirituality/religiosity, and academic achievement. Good performance in sports enables them to have some control over their behavior and their future. We suggest that school administrators might want to encourage their female students to be active in sports, and parents might want to encourage their daughters to be active in sports, as it helps in achievement orientation and moral development.
The Effect of Availability of Vertical Space on Personal Space

Summary The horizontal personal space requirements of 48 adult S s were examined under two conditions of vertical space. S s were matched by height and sex and assigned to a high or low ceiling height. S s told an approaching stranger to stop when the approacher's closeness made them feel uncomfortable. A significant result was that, as the distance between the ceiling and the top of the head was reduced, more personal space was required for the S s to feel comfortable. This finding supports a bubble model of personal space. No significant difference was found between the personal space requirements of males and females. The interaction between sex and ceiling height was not significant.
Accurate detection of elevated left ventricular filling pressure by a simplified bedside application of the Valsalva maneuver.

Abstract The hemodynamic effects induced by the Valsalva maneuver in both the normal and failing heart were initially described over 40 years ago by Hamilton et al. 1 Since then, clinicians have attempted to exploit the Valsalva maneuver to help evaluate a variety of cardiac conditions. 2–12 The normal response of arterial pressure during the Valsalva maneuver is characterized by an initial increase followed by a rapid decline below the resting level (Figure 1A). With release of strain, systolic pressure transiently declines, then overshoots above the pre-Valsalva level and elicits an accompanying bradycardia. However, in congestive heart failure systolic pressure remains persistently elevated throughout strain and simply returns to baseline with termination, without an overshoot or bradycardia (square-wave response) (Figure 1B). 1–4 The failure of arterial pressure to decrease during the Valsalva maneuver in congestive heart failure results primarily from an elevated central blood volume (reflected by an increased left ventricular [LV] filling pressure) acting as a reservoir to preserve LV filling despite a decrease in right-sided venous return during strain. 13–14 We reasoned that by determining the fate of systolic pressure during strain, patients with elevated and normal LV filling pressures could be discerned at the bedside. This prospective study was designed to test the validity of this assumption using a simple bedside application of the Valsalva maneuver.
The Okubo-Zweig-Iizuka rule near new thresholds

Abstract Because of unitarity we expect the breaking of the Okubo-Zweig-Iizuka (OZI) rule to be abruptly increased at the new threshold (K K , D D ). Cancellations make the rule much better at high energies and below the threshold. Many experimental puzzles can then be understood.
The effect of nitrogen diffusion hardening on the surface chemistry and scratch resistance of Ti-6Al-4V alloy

Modular, head-stem, mixed-metal connections are susceptible to mechanically mediated electrochemical interactions. Any attempt to improve the performance of these connections should center around increasing their resistance to mechanical damage, particularly the titanium alloy (Ti64). This study investigated the effect of a nitrogen-diffusion-hardening process on Ti64, with specific reference to changes in composition, chemistry, electrochemistry and its ability to resist and/or repassivate scratch damage. The nitrogen-diffusion-hardened Ti64 alloy had TiN and TiNO complexes at the immediate surface and sub-surface layers. The diffusion-hardened samples also had a deeper penetration of oxygen compared to regular Ti64 alloy samples. The electrochemical impedance spectroscopy data corroborated the increased thickness of the barrier oxide on the diffusion-hardened samples. The nitrogen-diffusion-hardened samples were more resistant to scratch damage and repaired/repassivated faster after such damage. The results suggest that the nitrogen-diffusion-hardened titanium alloy should exhibit increased resistance to mechanical-electrochemical interactions in mixed-metal modular interfaces in total hip prostheses.
Thermodynamic and quantum chemistry characterization of the adsorption of triazole derivatives during Muntz corrosion in acidic and neutral solutions

Abstract Some triazole derivatives (4-amino-5-mercapto-3-methyl 1,2,4-triazole (AMMT), 4-amino-5-mercapto-3-ethyl 1,2,4-triazole (AMET) and 4-amino-5-mercapto-3-propyl 1,2,4-triazole (AMPT)) have been evaluated as new corrosion inhibitors for the corrosion of muntz alloy (60Cu–40Zn) in acidic and neutral solutions. The adsorption of these compounds has been tested thermodynamically which was found to be of a physisorption mode. Furthermore, some activation thermodynamic parameters such as ΔH*, ΔS* and ΔG* of activation have been estimated. In addition, a trial to find a quantitative relationship between the inhibition efficiency and the electronic properties of the inhibitor molecules was carried out.
Effects of early bilingualism on learning phonological regularities in a new language.

Abstract Drawing on structural sensitivity theory, the current study investigated monolingual and bilingual children’s ability to learn how phonemes combine to form acceptable syllables in a new language. A total of 186 monolingual and bilingual kindergarteners, first graders, and second graders in Taiwan participated in the study. Bilingual children, regardless of whether they actively used a second language at home or simply had exposure to it, showed an advantage over their monolingual peers in learning the phonological patterns in the new language. The study provides empirical support for structural sensitivity theory and calls for the need to reconceptualize the effects of early bilingualism.
Alcohol‐Mediated Purkinje Cell Loss in the Absence of Hypoxemia During the Third Trimester in an Ovine Model System

Background : Although the mechanisms that underlie fetal alcohol-induced neuronal loss have not been determined, hypoxia/hypoxemia has been considered a leading candidate. This study was designed to test the hypothesis that neuronal loss could occur in the developing brain in the absence of fetal hypoxemia. Methods: Three groups of pregnant sheep were used: a control group, a binge-drinking group, and a pair-fed group. The alcohol and pair-fed animals were anesthetized on day 113 of pregnancy, and the mothers and fetuses were instrumented with arterial and venous catheters. All animals were killed on day 133. Stereological cell counting techniques were used to estimate the total number of Purkinje cells in the fetal cerebellum. Results: Peak maternal and fetal blood alcohol concentrations did not produce fetal hypoxemia. Nevertheless, there was a 25% loss of Purkinje cells of the cerebellum in the alcohol-exposed fetuses compared with that in the pair-fed controls. The loss of neurons was not accompanied by microencephaly or a concomitant decrease in either cerebellar weight or volume of the fetal cerebellum. Conclusions: Neuronal loss can be observed after alcohol exposure during the third trimester equivalent in fetal sheep in the absence of alcohol-induced hypoxemia. Furthermore, cell loss in the absence of deficits in gross brain weight or regional brain volume indicates that the lack of gross brain volume deficits from magnetic resonance imaging techniques is not a reliable indication that the brain is unaffected by the alcohol exposure.
Serum Cholinesterase Activity in Thymectomized Rats

SummaryAlthough the thyroid gland influences both the status of the thymus and serum cholinesterase activity, thymectomy alone has no influence on serum cholinesterase activity.
Obstetric Fistula Is a “Neglected Tropical Disease”

The term “neglected tropical diseases” (NTDs) is commonly used to refer to a “baker's dozen” of infectious conditions prevalent in resource-poor tropical countries. The 13 core diseases in the NTD group include ascariasis, dracunculiasis, hookworm, lymphatic filariasis, onchocerciasis, schistosomiasis, trichuriasis, Chagas disease, human African trypanosomiasis, Buruli ulcer, leprosy, and trachoma [1]. The World Health Organization has expanded the list to 17 conditions (http://www.who.int/neglected_diseases/en/), and some authors add another 20 or so fungal, viral, and ectoparasitic infections to the list [1]. Here I argue that obstetric fistula should be classified as an NTD because it, like the infectious conditions listed above, is also a preventable, treatable malady responsible for much suffering, stigmatization, and lost productivity among the impoverished “bottom billion” of the world's population.
Addiction and the brain: The neurobiology of compulsion and its persistence

People take addictive drugs to elevate mood, but with repeated use these drugs produce serious unwanted effects, which can include tolerance to some drug effects, sensitization to others, and an adapted state - dependence - which sets the stage for withdrawal symptoms when drug use stops. The most serious consequence of repetitive drug taking, however, is addiction: a persistent state in which compulsive drug use escapes control, even when serious negative consequences ensue. Addiction is characterized by a long-lasting risk of relapse, which is often initiated by exposure to drug-related cues. Substantial progress has been made in understanding the molecular and cellular mechanisms of tolerance, dependence and withdrawal, but as yet we understand little of the neural substrates of compulsive drug use and its remarkable persistence. Here we review evidence for the possibility that compulsion and its persistence are based on a pathological usurpation of molecular mechanisms that are normally involved in memory.
The use of computational fluid dynamic models for the optimization of cell seeding processes.

Abstract The seeding of a porous scaffold with stem cells is a fundamental step in engineering sizeable tissue constructs that are clinically viable. However, a key problem often encountered is inhomogeneous seeding of the cells particularly when the cells are delivered through the thickness of the scaffold. The objective of this study was to establish the quantitative relationships between the cell seeding efficiency and the initial vacuum pressure in a compact perfusion seeding device that uses the effect of differential pressure induced by vacuum to seed cells on a porous scaffold. A transient CFD solution of the fluid flow in the device was used to optimize the initial vacuum pressure for efficient cell seeding. Results indicate that the optimal initial vacuum pressure for homogenous cell seeding is approximately −20 kPa for the seeding device. This study presents a 3-D computational model that can be employed in designing and optimizing cell seeding techniques and corresponding technology.
Lightweight monitoring of sensor software

Wireless sensors are very small computers, and understanding the timing and behavior of software written for them is crucial to ensuring that they perform correctly. This paper outlines a lightweight method for gathering behavioral and timing information from simulated executions of software written in the nesC/TinyOS environment. The resulting data is used to generate both behavioral and timing profiles of the software, using UML sequence diagrams to visualize the behavior and to present the timing information.
A simple model describes the PDF of a non-graphitizing carbon

Abstract A model for the structure of a non-graphitizing carbon is built by randomly incorporating between 0.5% and 4% non-hexagonal rings into an extended sp2 carbon sheet. The sheets are created using Cerius2 Modeling software, optimized using a DREIDING force-field, and turbostratically layered to create a three-dimensional structure. We show that the calculated pair distribution function (PDF) for models containing approximately 1% non-hexagonal rings is remarkable similar to the experimental PDF obtained from neutron scattering by a non-graphitizing carbon prepared from polyfurfuryl alcohol pyrolyzed at 1200 °C. No attempt was made to fit the model to the experimental data, and the model has no adjustable parameters except for the fraction of non-hexagonal rings.
Effect of dietary sorghum cultivars on the storage stability of broiler breast and thigh meat.

Abstract A total of 450 1-d-old male broiler chicks were fed a corn-soy-flax meal-based diet (control), two cultivars of sorghum-Ruby Red (low tannin content) and Valpo Red (high tannin content)–were used at 10% level. Birds were slaughtered at the end of 42-d feeding trial. Boneless, skinless breast and thigh muscles were separated and ground to make patties. Half of the breast and thigh meat patties were individually packaged in zipper bags, and 2-TBA-reactive substances (TBARS) and colors of the patties were determined after 0 and 7 d of storage at 4 C. The other half was cooked and vacuum-packaged. The vacuum-packaged patties were used to determine time-dependent volatile production and oxidative change during 12-h holding time before analyses. Thigh meat from broilers fed the Valpo Red cultivar produced lower TBARS than that from control at Day 0. The amounts of aldehydes and sulfur compounds of cooked breast meats were lower from chickens fed the Valpo Red cultivar than those fed the control or Ruby Red cultivar. Dietary Valpo Red cultivar improved the oxidative stability of breast meat 8 and 12 h after cooking. Dietary sorghum slightly improved the color a* stability of raw thigh meat patties. This result indicated that feeding sorghum to broilers could improve some measures of the storage stability of broiler meat, but sorghum with high tannin content was more effective than that with low tannin content.
Chlorpromazine and Epinephrine Hyperglycemic Mechanisms

Chlorpromazine administration resulted in hyperglycemia in the intact, but not in the adrenalectomized, rat. However, chlorpromazine potentiated epinephrine-induced hyperglycemia in both intact and adrenalectomized animals. β-Adrenergic blockade prevented chlorpromazine-induced as well as epinephrine- and isoproterenol-induced hyperglycemia. α-Adrenergic blockade potentiated epinephrine-induced hyperglycemia. A significant reduction of tolerance to glucose loading was exhibited in both intact and adrenalectomized rats after treatment with chlorpromazine. The results indicate that the adrenals are necessary for chlorpromazine-induced hyperglycemia and that chlorpromazine impairs peripheral utilization of glucose.
Following cancer prevention guidelines reduces risk of cancer, cardiovascular disease and all-cause mortality

Background: Few studies have evaluated the combined impact of following recommended lifestyle behaviors on cancer, cardiovascular disease (CVD) and all-cause mortality, and most included tobacco avoidance. Because 80% of Americans are never or former smokers, it is important to consider the impact of other recommended behaviors. Methods: In 1992 and 1993, 111,966 nonsmoking men and women in the Cancer Prevention Study-II Nutrition Cohort completed diet and lifestyle questionnaires. A score ranging from 0 to 8 points was computed to reflect adherence to the American Cancer Society cancer prevention guidelines on body mass index, physical activity, diet, and alcohol consumption, with 8 points representing optimal adherence. Multivariable-adjusted relative risks (RR) of death and 95% CI were computed by Cox proportional hazard regression. Results: During 14 years of follow-up, 10,369 men and 6,613 women died. The RR of all-cause mortality was lower for participants with high (7, 8) versus low (0–2) scores (men, RR = 0.58, 95% CI: 0.53–0.62; women, RR = 0.58, 95% CI: 0.52–0.64). Inverse associations were found with CVD mortality (men, RR = 0.52, 95% CI: 0.45–0.59; women, RR = 0.42, 95% CI: 0.35–0.51) and cancer mortality (men, RR = 0.70, 95% CI: 0.61–0.80; women, RR = 0.76, 95% CI: 0.65–0.89). Similar associations, albeit not all statistically significant, were observed for never and former smokers. Conclusion: Adherence to cancer prevention guidelines for obesity, diet, physical activity, and alcohol consumption is associated with lower risk of death from cancer, CVD, and all causes in nonsmokers. Impact: Beyond tobacco avoidance, following other cancer prevention guidelines may substantially lower risk of premature mortality in older adults. Cancer Epidemiol Biomarkers Prev; 20(6); 1089–97. ©2011 AACR . This article is featured in Highlights of This Issue, [p. 1057][1] [1]: /lookup/volpage/20/1057?iss=6
The salt-extractable fraction of dynein from sea urchin sperm flagella: an analysis by gel electrophoresis and by adenosine triphosphatase activity.

Previous work has shown that the dynein from axonemes of sea urchin sperm consists of two distinct fractions which differ substantially in their extractability by salt. Upon gel electrophoresis of whole demembranated axonemes solubilized with sodium dodecyl sulfate, the dynein fraction shows two closely spaced bands with apparent molecular weights of 520,000 and 460,000; the proteins in these bands are termed the A and B components of the dynein. Similar electrophoresis of the soluble fraction obtained by extracting the axonemes with 0.5 M NaCl shows a single prominent band containing approximately half of the A component of the dynein (A1 component). The residue of extracted axonemes contain the other half of the A component of the dynein (A2 component) and all the B component. Densitometry of the bands indicates that the A1, A2 and B components of the dynein are present in approximately equal molar quantity. Electron microscopic studies show that the A1 component of the dynein constitutes the outer arms on the doublet tubules. Assay of ATPase activity in 0.05 M KCl and l mM ATP indicates about 65% of the total ATPase activity becomes soluble when the A1 component of the dynein is extracted with salt.
Molecular characterization of a pea beta-1,3-glucanase induced by Fusarium solani and chitosan challenge.

β-glucanases are prominent proteins in pea endocarp tissue responding to fungal infection. We have cloned and sequenced a partial pea cDNA clone, pPIG312, corresponding to a β-1,3-glucanase in pea pods challenged with the incompatible pathogen Fusarium solani f. sp. phaseoli. The insert from the partial pea cDNA was used to probe a genomic library derived from pea leaves of the same cultivar. One of the genomic clones, pPIG4-3, contained the complete coding sequence for a mature β-1,3-glucanase protein. The predicted amino acid sequence of the pea β-1,3-glucanase has 78% identity to bean β-1,3-glucanase, 62% and 60% to two tobacco β-1,3-glucanases, 57% to soybean β-1,3-glucanase, 51% to barley β-1,3-glucanase, and 48% to barley β-1,3-1,4-glucanase. Genomic Southern analysis indicates that the pea genome contains only one β-1,3-glucanase gene corresponding to the probe used in this study. Accumulation of β-1,3-glucanase mRNA homologous with the pPIG312 probe was detected in pea pods within 4 to 8 h after challenge with F. solani f. sp. phaseoli, f. sp. pisi, a compatible strain, or the elicitor, chitosan. In the incompatible reaction, mRNA accumulation remained high for 48h, whereas it rapidly decreased in the compatible reaction. After fungal inoculation of whole pea seedlings, the enhanced mRNA accumulation occurred mainly in the basal region (lower stem and root). This β-1,3-glucanase glucanase mRNA was constitutively expressed in the roots of pea seedlings. The sustained levels of β-glucanase mRNA expression induced by the incompatible pathogen in the resistance response suggests that the enzyme contributes to the pea plant's general defense.
A Meta-analysis of Methods to Prevent Venous Thromboembolism Following Total Hip Replacement

Objective. —While several methods of prophylaxis have been shown to reduce the risk of venous thromboembolism following total hip replacement, the safest and most effective agent is unclear. To clarify this issue, we performed a meta-analysis of the randomized trials of methods used to prevent venous thromboembolism following total hip replacement. Data Source. —English-language human studies articles from 1966 through 1993 were obtained from a MEDLINE database search with indexing terms includingthromboembolism, hip replacementorhip prosthesis, andrandomized controlled trials. Additional references were obtained from study bibliographies. Study Selection. —The following criteria were used to select studies for inclusion: study design—randomized clinical trial; study population—patients undergoing elective total hip replacement; interventions—aspirin, warfarin, dextran, heparin, low-molecular-weight heparin, compression stockings; and outcomes— venous thromboembolism, major hemorrhage. Data Extraction. —Methodological and descriptive data from each study were abstracted by one author who was blinded to quantitative outcomes data. Data Synthesis. —Ninety-one treatment groups and 25 control groups were identified from 56 trials. Four treatment groups were excluded because of rarely used combinations. Trial populations were clinically homogeneous. When compared with the control arm, all treatments except aspirin reduced the risk of all deep venous thromboses (risk differences range, 0.18 to 0.31; allPvalues Conclusions. —The results suggest that low-molecular-weight heparin and compression stockings have the greatest relative efficacy in preventing venous thromboembolism following total hip replacement. Low-molecular-weight heparin may be more effective, though at a small risk of clinically important bleeding. (JAMA. 1994;271:1780-1785)
Zinc binding-induced near-IR emission from excited-state intramolecular proton transfer of a bis(benzoxazole) derivative

A bis(benzoxazole) derivative with metal-chelating ligand (DPA), Zinhbo-1, exhibits a large fluorescence turn-on effect (up to 10-fold) upon zinc-binding. The metal chelation enables excited state intramolecular proton transfer (ESIPT), giving an additional emission band in the near-IR region (∼710 nm) with a large Stokes shift (ca. 230 nm).
Rosette spectroscopic imaging: Optimal parameters for alias-free, high sensitivity spectroscopic imaging

Purpose To optimize the Rosette trajectories for fast, high sensitivity spectroscopic imaging experiments and to compare this acquisition technique with other chemical shift imaging (CSI) methods. Materials and Methods A framework for comparing the sensitivity of the Rosette Spectroscopic Imaging (RSI) acquisition to other spectroscopic imaging experiments is outlined. Accounting for hardware constraints, trajectory parameters that provide for optimal sampling and minimal artifact production are found. Along with an analytical expression for the number of excitations to be used in an RSI experiment that is provided, the theoretical precompensation weights used for optimal image reconstruction are derived. Results The spectral response function for RSI is shown to be approximately the same as the point spread function of standard Fourier reconstructions. While the signal-to-noise ratio (SNR) for an RSI experiment is reduced by the inherent nonuniform sampling of these trajectories, their circular k-space support and speed of spatial encoding leads to greater SNR efficiency and improvements in the total data acquisition time relative to the gold standard CSI approach with square k-space support and to similar efficiency to spiral CSI acquisitions. Numerical simulations and in vivo experimental data are presented to demonstrate the properties of this data acquisition technique. Conclusion This work demonstrates the use of Rosette trajectories and how to achieve improved efficiency for these trajectories in a two-dimensional spectroscopic imaging experiment. J. Magn. Reson. Imaging 2009;29:1375–1385. © 2009 Wiley-Liss, Inc.
Use of the peroxidase‐antiperoxidase technique for differential staining of multiple cell types in the rat pancreatic islet

Multiple staining of the endocrine cells of the pancreatic islet was studied in tissue obtained from adult rats. After fixation in Bouin's fluid and processing for light microscopy, the unlabeled peroxidase-antiperoxidase (PAP) technique was performed. Successful staining procedures used variations of the PAP technique with 3,3'-diaminobenzidine (DAB) and 4-chloro-1-naphthol (CN) as chromagens. The purpose of this study was to stain as many of the four primary cell types (A-cells, B-cells, D-cells, PP-cells) as possible either simultaneously or sequentially using photomicroscopy. At optimum antibody titer, there was minimal nonspecific background staining which made it possible to differentiate cell types by intensity of the chromagen. Any two cell types can be shown by using DAB with the first antibody and CN with the second. To demonstrate three cell types simultaneously, three methods which altered dilutions and chromagens were used. The first method consisted of decreasing dilutions of primary antibody with DAB and CN as the chromagens. The second method involved repetitive DAB applications resulting in three intensities of brown. The third method used a DAB immersion after the second cell type was stained. This produced a color differential so the third cell type could be distinguished with CN. To demonstrate the three cell types sequentially, a masking technique was introduced with photomicroscopy. In order to block the preceding complex, the previous cell type (demonstrated by CN) was restained with DAB at an increased dilution. The next cell type was then stained with CN. These four methods were tried in attempts to stain four cell types in the same tissue section.
Response to Greene 2001, Redefining Social Work

This article is in response to the article titled Redefining Social Work for the New Millennium: Setting a Context, by Dr. Roberta Greene. I have come to view social work as a profession that seeks to enable others not just the poor and undeserved, the opportunity to better understand and navigate any situation that causes them stress or presents some type of barrier to their health and well-being.
Babbling, vegetative function, and language development after cricotracheal resection in aphonic children.

Objective: To determine the importance of prelinguistic babbling by studying patterns of speech and language development after cricotracheal resection in aphonic children. Study Design: Retrospective review of seven previously aphonic children who underwent cricotracheal resection by our pediatric thoracic airway team. The analyzed variables include age, sex, comorbidity, grade of stenosis, length of resected trachea, and communication methods. Methods: Data regarding the children's pre- and postsurgical communication methods, along with their utilization of speech therapy services, were obtained via speech–language pathology evaluations, clinical observations, and a standardized telephone survey supplemented by parental documentation. Postsurgical voice quality was assessed using the Pediatric Voice Outcomes Survey. Results: All seven subjects underwent tracheostomy prior to 2 months of age when corrected for prematurity. The subjects remained aphonic for the entire duration of cannulation. Following cricotracheal resection, they experienced an initial delay in speech acquisition. Vegetative functions were the first laryngeal sounds to emerge. Initially, the children were only able to produce these sounds reflexively, but they subsequently gained voluntary control over these laryngeal functions. All subjects underwent an identifiable stage of canonical babbling that often occurred concomitantly with vocalizations. This was followed by the emergence of true speech. Conclusions: The initial delay in speech acquisition observed following decannulation, along with the presence of a postsurgical canonical stage in all study subjects, supports the hypothesis that babbling is necessary for speech and language development. Furthermore, the presence of babbling is universally evident regardless of the age at which speech develops. Finally, there is no demonstrable correlation between preoperative sign language and rate of speech development.
Katalysatoren für die lebende Insertionspolymerisation von Alkenen: mit Ziegler-Natta-Chemie zu neuartigen Polyolefin-Architekturen

Koordinations-Insertions-Polymerisationen sind, was die Stereokontrolle anbelangt, ihren anionischen, kationischen und radikalischen Gegenstucken schon lange uberlegen. Innerhalb des Bereichs lebender Polymerisationen (d. h. Polymerisationen mit rascher Initiierung und vernachlassigbarer Zahl von Kettenabbruchen oder -ubertragungen) waren diese Insertionsverfahren auf Metallbasis ionischen und radikalischen Reaktionen dagegen bis vor etwa funf Jahren unterlegen. Inzwischen wurden lebende Insertionspolymerisationen von nichtaktivierten Olefinen zu leistungsfahigen Syntheseverfahren fur neuartige Polymerarchitekturen entwickelt. Auf diesem Weg ist heute eine Bandbreite von Materialien zuganglich, die von einfachen Homopolymeren wie linearem und verzweigtem Polyethylen uber ataktische oder taktische Poly(α-olefine) und endgruppenfunktionalisierte Polymere bis hin zu Blockcopolymeren reicht. Dieser Aufsatz fasst neuere Entwicklungen in diesem schnell wachsenden Forschungsgebiet an der Schnittstelle von praparativer und mechanistischer metallorganischer Chemie, Polymerchemie und Materialwissenschaft zusammen. Wir gehen dabei besonders auf Eigenschaften und neuartige Architekturen von Polymeren ein, von denen die meisten vor zehn Jahren noch nicht existierten. Ferner berichten wir uber wichtige Fortschritte beim Design von Liganden und Katalysatoren.
A new rotating gradient disk: brightness, flicker, and brightness aftereffects.

Abstract A disk is divided into 18 equal sectors, each a different shade of gray. The sectors range from black through white in a stepwise circumferential brightness gradient comparable to a circular optical wedge. The disk appears brighter rotating in one direction and darker rotating in the other, thus producing two brightness-frequency functions, one for each direction of rotation. Below the critical flicker frequency, apparent brightness depends jointly on the frequency and direction of rotation, but Talbot-level brightness and critical flicker frequency are independent of rotation direction. Rotation in one direction produces an aftereffect of apparent brightening in a subsequently viewed steady light, and rotation in the other direction produces a dimming aftereffect.
Cloning and sequencing of a gene encoding yeast thioltransferase.

Abstract A 69 bp yeast genomic DNA fragment encoding yeast thioltransferase was amplified by PCR technique. A yeast genomic DNA library was screened by a specific probe obtained from the PCR product. An 718 bp DNA fragment was found to encode yeast thioltransferase and its flanking sequence. The deduced amino acid sequence of the gene, designated TTR, agrees with that derived from conventional amino acid sequence analysis except two extra amino acids on the C-terminus. In contrast to yeast thioredoxin, Southern blot analysis of total yeast genomic DNA indicated that there was only one copy of gene encoding yeast thiotransferase. A putative TATA box was found at 109 bp from the starting codon. However, no polyadenylation signal sequence was identified on the DNA sequence downstream the 3′ end of the gene.
Chromosomal change and rectangular evolution in North American cyprinid fishes

SUMMARY An important question in evolutionary biology concerns the manner and tempo in which organismal andjor genetic changes that promote evo­ lutionary divergence occur. One recent hypothesis, termed rectangular evolution, holds that most significant evolutionary change occurs during occasional or periodic speciation episodes, with long periods of evolution­ ary stability in the interim. An alternative view, termed phyletic grad­ ualism, holds that evolutionary divergences proceed by the slow and even accumulation of genetic differences within populations of established species. Two brief tests of rectangular evolution are presented using chromosomal data from North American cyprinid fishes (minnows), a group known to have experienced heterogeneous rates of splitting. Within the rapidly speciated genus Notropis, rates of chromosomal evolution appear slower relative to other, less rapidly speciated confami­ lial genera. Species of Notropis also are less divergent chromosomally, on the average, than are species from other cyprinid genera. These results are incompatible with a rectangular mode of chromosomal divergence in these fishes. The results also reveal inconsistencies with a gradual mode of chromosomal divergence, but at present this hypothesis cannot be falsified. Consideration of these and other data suggests that different levels of the cyprinid genome may follow independent evolutionary paths.
Analysis of prednisone, prednisolone and their 20β-hydroxylated metabolites by high-performance liquid chromatography

Abstract A high-performance liquid chromatographic technique primarily developed for use on samples from kidney perfusion studies is presented for simultaneous determination of prednisone, prednisolone and their 20β-hydroxylated metabolites. The technique employs 6β-hydroxycortisol as the internal standard. Samples are extracted with ethyl acetate, washed with sodium hydroxide and water and injected onto a silica gel column with UV detection at 254 nm. Inter- and intraday variability of the assay was determined at two concentrations of each steroid and was less than 10%. Assay steroid recovery ranged from 54.1% for prednisone to 63.2% for 20β-hydroxyprednisone. Sensitivity is 4–10 ng/ml for the steroids measured. The chromatographic conditions may be modified to permit quantitation of these steroids from plasma samples. This method may alternatively be used for quantitation of 6β-hydroxycortisol, an endogenous indicator of enzyme induction. A perfusate concentration-time profile is presented from a kidney perfusion study using prednisolone.
DNA sequence-specific binding of transformed Ah receptor to a dioxin responsive enhancer : looks Aren't everything

Abstract Gel retardation analysis has been utilized to examine the ability of transformed hepatic cytosolic TCDD:AhR complex to bind to its specific DNA recognition site, the dioxin responsive element (DRE). Although DRE sequence alignment has identified a conserved DNA recognition sequence of C/GNNNC/GTNGCGTGNC/GT/ANNNC/G, site-directed mutagenesis has demonstrated that not all of these bases are important for DNA binding. A putative TCDD:AhR DRE-binding consensus of GCGTGNNA/TNNNG/C has been derived from our studies and it is highly conserved among species. In addition, we present a model for the DNA-binding of transformed TCDD:AhR complex.
DISCOUNT RATES FOR GOVERNMENT INVESTMENT PROJECTS: THE ECONOMIC LOGIC BEHIND OMB CIRCULAR A-94

ABSTRACT This paper examines U.S. Office of Management and Budget (OMB) Circular A-94, which requires that costs and benefits of government programs be discounted at the U.S. Treasury borrowing rate on bonds of maturity equal to the period of analysis. It is shown that, in a 2-period problem, discounting at the Treasury rate always leads to the correct investment decision. That is, the winning project may always be transformed, via market transactions, into one that dominates the losing project. Some anomalies occur when evaluating projects of longer duration, but these anomalies are probably not important empirically. Finally, the dominating project may be computed using linear programming.
Yersinia enterocolitica: overview and epidemiologic correlates.

Yersinia enterocolitica comprises both pathogenic and nonpathogenic members. Distinguished by biogrouping, serogrouping, and ecological distribution, commonly occurring pathogenic serobiogroups, e.g., O:3/4; O:5,27/2; O:8/1b; O:9/2, possess both chromosomal and plasmid-mediated virulence traits. Studies have revealed several (oral, blood transfusion) modes of acquisition, elucidated the putative role of chromosomal and plasmid-encoded virulence factors in the pathogenesis of human infection, and have identified major animal reservoirs, e.g., the pig. Diagnosis has been refined though use of selective media, monoclonal antibodies directed against outer membrane proteins, and of purified yersiniae outer membrane proteins for antibody detection. Epidemiological investigations of foodborne outbreaks have been advanced through the use of molecular biology techniques such as ribotyping and pulsed-field gel electrophoresis.
Chronic methylphenidate exposure during adolescence reduces striatal synaptic responses to ethanol.

Dopamine (DA) plays an important role in integrative functions contributing to adaptive behaviors. In support of this essential function, DA modulates synaptic plasticity in different brain areas, including the striatum. Many drugs used for cognitive enhancement are psychostimulants, such as methylphenidate (MPH), which enhance DA levels. MPH treatment is of interest during adolescence, a period of enhanced neurodevelopment during which the DA system is in a state of flux. Recent epidemiological studies report the co-abuse of MPH and ethanol in adolescents and young adults. Although repeated MPH treatment produces enduring changes that affect subsequent behavioral responses to other psychostimulants, few studies have investigated the interactions between MPH and ethanol. Here we addressed whether chronic therapeutic exposure to MPH during adolescence predisposed mice to an altered response to ethanol and whether this was accompanied by altered DA release and striatal plasticity. C57BL/6J mice were administered MPH (3-6 mg/kg/day) via the drinking water between post-natal days 30 and 60. Voltammetry experiments showed that sufficient brain MPH concentrations were achieved during adolescence in mice to increase the DA clearance in adulthood. The treatment also increased long-term depression and reduced the effects of ethanol on striatal synaptic responses. Although the injection of 0.4 or 2 g/kg ethanol dose-dependently decreased locomotion in control mice, only the higher dose decreased locomotion in MPH-treated mice. These results suggested that the administration of MPH during development promoted long-term effects on synaptic plasticity in forebrain regions targeted by DA. These changes in plasticity might, in turn, underlie alterations in behaviors controlled by these brain regions into adulthood. Language: en
Endosymbiosis: Lessons in Conflict Resolution

© 2004 Jennifer J. Wernegreen. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in PLoS Biology 2 (2004): e68, doi:10.1371/journal.pbio.0020068.
Role of Platelets and Leukocytes in Modulation of Vascular Tonea

Activated platelets and leukocytes release potent vasoactive factors that may modulate vascular tone. Activation of normal platelets produces dilatation of normal arteries. Vasodilatation is mediated by adenosine diphosphate (ADP), which releases endothelium-derived relaxing factor (EDRF) from endothelium. In atherosclerotic arteries, activation of platelets produces constriction and perhaps spasm. The constrictor response of atherosclerotic arteries is related in part to profound changes in vascular function: endothelial dysfunction with impaired endothelium-dependent vasodilator responses to ADP, and augmented vasoconstrictor responses to serotonin. In addition, hypercholesterolemia has a direct effect on platelets, resulting in impaired vasodilator responses. Thus, abnormal platelets and altered vascular function may both predispose to spasm of atherosclerotic arteries. Activation of leukocytes has little effect on resistance of large arteries in normal monkeys. In contrast, activation of leukocytes produces pronounced vasoconstriction in atherosclerotic monkeys. Possible mediators of vasoconstriction include prostaglandin E2, oxygen radicals, thromboxane, and a peptide (perhaps angiotensin II). In addition, leukocytes also alter vascular responses to platelets, in part by ADPase on the leukocyte membrane, which degrades ADP released by activated platelets. Leukocytes also release oxygen radicals, which may inactivate EDRF, thereby impairing ADP-mediated, endothelium-dependent vasodilator responses. Abnormal responses to platelets and leukocytes are largely reversed when atherosclerotic lesions regress in monkeys.
Pulsed beam propagation through random media.

The effect of the turbulent atmosphere on the propagation of an ultrashort pulsed beam is presented in terms of time-domain statistical moment equations. Pulsed beams are localized space–time solutions of the wave equation that propagate unchanged along the ray trajectories. The statistically closed equations that are derived are considerably different from the dispersive multiple-frequency equation that is often used for pulse propagation. It is shown that the coherent intensity of the pulsed beam decays on a scale of the order of 10−3–103 m, depending on the conditions of turbulence. This underscores the importance of the statistical feasibility of propagation in addition to the practical realizability, which is customarily emphasized.
EXPRESSION DEFECTS OF MUTANT HUMAN ADENOSINE DEAMINASE: 42

A severe deficiency of adenosine deaminase (ADA) is associated with an autosomal recessive form of severe combined immunodeficiency disease, while subjects with partial enzyme activity are immunocompetent. To further our understanding of ADA deficiency, specific mRNA levels and rates of protein turnover were determined in partial. ADA deficient cells and enzyme expression of cloned human ADA cDNA was assessed. Genetic expression of ADA in cultured B lymphoblast cell lines from 4 partially (5-50% activity) ADA deficient subjects showed normal to 2-fold normal ADA mRNA levels (Northern blot). Among these cell lines enzyme synthesis varied from 165% to 15% of normal. ADA degradation rates were 1.5 to almost 3 times faster than normal, consistent with the complete absence of the enzyme in patient erythrocytes. Cloned normal human ADA cDNA inserted into an SV40 based expression vector was shown to generate human ADA activity in monkey kidney (COS) host cells (7-fold over host). An unexpected finding was the identification of another normal human ADA cDNA construct which failed to produce human ADA activity or immunoreactive protein upon transfection. DNA sequence analysis revealed a single nucleotide substitution within this clone that altered the predicted sequence of ADA protein at amino acid 50.
Ethanol-induced, nonexocytotic [3H]dopamine release from rat nucleus accumbens slices.

Abstract This study was designed to investigate whether a carrier-dependent mechanism is involved in ethanol-induced dopamine release in vitro. Rat nucleus accumbens slices were incubated with [ 3 H]dopamine in the presence of pargyline and then superfused. Spontaneous [ 3 H]dopamine release was unaffected by addition of tetrodotoxin or withdrawal of calcium, but was increased significantly with treatment with nomifensine, a dopamine transporter blocker. Exposure of the slices to electrical field stimulation (bipolar pulse, 2-ms long, 20 mA, 0.5 Hz for 4 min), high potassium concentration (30 mM, 2 min), or ethanol (25–100 mM, 2 min) was associated with increased [ 3 H]dopamine release. With addition of tetrodotoxin or withdrawal of calcium from the perfusion medium, a 75% or greater inhibition of electrically or high potassium concentration–evoked [ 3 H]dopamine release was observed, but ethanol-induced [ 3 H]dopamine release was not altered. Treatment with nomifensine potentiated electrically or high potassium concentration–evoked [ 3 H]dopamine release, but inhibited the effects of ethanol on [ 3 H]dopamine release from the nucleus accumbens slices. The results indicate that the mechanism underlying the effects of ethanol is different from that underlying the effects of depolarization with electrical stimulation or high potassium concentration and support the suggestion that a nonexocytotic, carrier-mediated mechanism may be involved in ethanol-evoked dopamine release in vitro.