cssi/SciSciGPT-SciSciNet huggingface dataset:
What dopamine does in the brain

In the early 1970s, receptors for neurotransmitters acting via second messengers had not been identified biochemically nor were there definitive links to such messengers. The discovery by John W. Kebabian and Paul Greengard of a dopamine-sensitive adenyl cyclase, accordingly, was a giant step forward. The investigators first characterized the enzyme in sympathetic ganglia wherein dopamine-producing cells link pre- and post-synaptic neurons. Then, in the corpus striatum, the brain area enriched in dopamine, they delineated the enzyme\x{2019}s properties and showed that it was inhibited by antipsychotic drugs, leading to a large body of research on dopamine as a mediator of antipsychotic drug action and putative roles for this transmitter in the pathophysiology of schizophrenia.
Executive Compensation and Agency Effects

The separation of ownership from control in large corporations can cause agency problems. This study analyzes the effects of the dispersion of corporate ownership on the compensation of the top executives of Fortune 500 companies. The effects are estimated across the executive hierarchy and for different components of the compensation package in contrast to more limited previous studies. The results indicate that there is a significant agency effect on executive pay, though the magnitude is small relative to company size. The effects are greatest for the most liquid form of remuneration, salaries, and are nonuniform across executive categories, with the strongest effect found for the Chairman of the Board.
French parents' cultural models and childrearing beliefs

This study explored, identified, and described “cultural models” of parenting shared by Parisian parents of infants and young children from birth to age 3 years. A questionnaire was constructed in the field to assess levels of importance attached to 50 practices associated with the daily care of infants and young children. Data were collected from a sample of 455 Parisian mothers and fathers and principal components analysis was used to identify three reliable components of parenting beliefs that constituted cultural models: “Awakening and exposing child to diverse stimuli”, “Ensuring proper presentation of child”, and “Responding to and bonding with child”. Four sociodemographic variables predicted variation in mean importance scores associated with each of the three cultural models: parent’s age, gender, education level, and religiosity, although the magnitudes of these associations were small. The discussion highlights the strengths and limitations of this method and offers suggestions for further rese...
Evidence for sequential ion-binding loci along the inner pore of the IRK1 inward-rectifier K+ channel.

Steep rectification in IRK1 (Kir2.1) inward-rectifier K+ channels reflects strong voltage dependence (valence of ∼5) of channel block by intracellular cationic blockers such as the polyamine spermine. The observed voltage dependence primarily results from displacement, by spermine, of up to five K+ ions across the narrow K+ selectivity filter, along which the transmembrane voltage drops steeply. Spermine first binds, with modest voltage dependence, at a shallow site where it encounters the innermost K+ ion and impedes conduction. From there, spermine can proceed to a deeper site, displacing several more K+ ions and thereby producing most of the observed voltage dependence. Since in the deeper blocked state the leading amine group of spermine reaches into the cavity region (internal to the selectivity filter) and interacts with residue D172, its trailing end is expected to be near M183. Here, we found that mutation M183A indeed affected the deeper blocked state, which supports the idea that spermine is located in the region lined by the M2 and not deep in the narrow K+ selectivity filter. As to the shallower site whose location has been unknown, we note that in the crystal structure of homologous GIRK1 (Kir3.1), four aromatic side chains of F255, one from each of the four subunits, constrict the intracellular end of the pore to ∼10 A. For technical simplicity, we used tetraethylammonium (TEA) as an initial probe to test whether the corresponding residue in IRK1, F254, forms the shallower site. We found that replacing the aromatic side chain with an aliphatic one not only lowered TEA affinity of the shallower site ∼100-fold but also eliminated the associated voltage dependence and, furthermore, confirmed that similar effects occurred also for spermine. These results establish the evidence for physically separate, sequential ion-binding loci along the long inner pore of IRK1, and strongly suggest that the aromatic side chains of F254 underlie the likely innermost binding locus for both blocker and K+ ions in the cytoplasmic pore.
Effect of fiber volume fraction, fiber length and fiber tow size on the energy absorption of chopped carbon fiber–polymer composites

Composite materials have the potential to reduce the overall cost and weight of automotive structures with the added benefit of being able to dissipate large amounts of impact energy by progressive crushing. To identify and quantify the energy-absorbing mechanisms in candidate automotive composite materials, modified test methodologies were developed for conducting progressive crush tests on flat-plate composite specimens. The test method development and experimental setup focused on isolating the damage modes associated with the frond formation that occurs in dynamic testing of composite tubes. The Automotive Composites Consortium (ACC) is interested in investigating the use of chopped carbon fiber–reinforced composites as crash-energy absorbers primarily because the low costs involved in their manufacture make them cost-effective for automotive applications. While many in the past have investigated the energy-absorption characteristics in various continuous fiber–reinforced composite materials, no literature is available on the energy-absorption and crushing characteristics of chopped carbon fiber–reinforced composite materials. Hence quasi-static progressive crush tests were performed on composite plates manufactured from chopped carbon fiber (CCF) with an epoxy resin system using compression-molding techniques, and the effect of material parameters (fiber volume fraction, fiber length, and fiber tow size) on energy absorption was evaluated by varying them during testing. Of the parameters evaluated, fiber length appeared to be the most critical material parameter determining the specific energy absorption of a composite material, with shorter fibers having a higher specific energy absorption than longer fibers, possibly because of the increased concentration of stress raisers in the shorter fiber specimens, resulting in a larger number of fracture-initiation sites. The combination of material parameters that yielded the highest energy-absorbing material was identified. The test observations and trends established from this work would help support the development of low-cost energy absorbers for the automotive industry. POLYM. COMPOS. 26:293–305 2005. Published 2005 Society of Plastics Engineers.
The lag effect with aurally presented passages

Two experiments examined free recall of aurally presented passages as a function of the size of the lag between repetitions of the passages. Experiment 1 demonstrated a significant lag effect up to lags of four passages. Experiment 2 extended the findings of the first experiment to lags of eight passages. Recall of the passages was shown to be a linear function of lag up to lags of eight passages.
An Alternative (Preferable) Friction Factor

An alternative to the traditional friction factor for pipe flow is presented (φ = [R]f). For incompressible flows, the correlation of this new friction factor with Reynolds Number [R] and Relative Roughness [e] is presented graphically, and appears much simpler and more intuitive than the Moody Diagram (or other equivalents). Moreover, relatively simple curve-fit formulas for representing φ explicitly as a function of R and e are presented for various flow regimes, along with measures of error associated with these approximate formulas.Copyright © 2006 by ASME
Effect of age on glucose oxidation by isolated rat islets.

Islets were isolated from pancreases of 2-month and 12-month-old rats, and the oxidation of14C-glucose to14CO2 determined at various medium D-glucose concentration. Islets from 12-month-old rats oxidized significantly less glucose than those from 2-month-old rats at glucose concentrations of 150, 300, and 450 mg/dl, and this was true when islets were selected by hand or by Ficoll density gradient separation. The effect of age on glucose oxidation was seen when islets were incubated with [U-14C], [1-14C], or [6-14C] glucose. The results raise the possibility that previously reported age-related defects in glucose-stimulated insulin secretion may be secondary to the effect of age on islet glucose catabolism.
Darstellung und eigenschaften von polyorganokobaltosiloxanen

Die Umsetzung von Dialkoxysilanen mit Kobalt(II)acetat fuhrt zu unloslichen und unschmelzbaren Produkten, die wahrscheinlich vernetzte Struktur besitzen. Wahrend Silandiole nicht mit Kobalthalogeniden reagieren, lassen sich Dinatriumsilandiolate, die aus Silandiolen und Natrium in flussigem Ammoniak hergestellt wurden, mit Kobalt(II)-bromid zu Polykobaltosiloxanen umsetzen. Die erhaltenen Harze sind niedermolekular, loslich in organischen Losungsmitteln, sprode, jedoch unschmelzbar. Cokondensation mit Aluminiumchlorid erhoht die Viskositatszahl der Produkte, ohne jedoch die sonstigen Eigenschaften merklich zu verandern. Wahrend man aus Trinatriumsilantriolaten und Kobalt(II)bromid unlosliche und unschmelzbare Produkte erhalt, fuhrt die stufenweise Cokondensation der Triolate mit Kobalt(II)bromid und Dichlorsilanen zu loslichen und bei 100 bis 150°C schmelzenden Harzen, die vermutlich eine bandartige Struktur besitzen. Alle Polykobaltosiloxane zeigen gute thermische Bestandigkeit, werden jedoch von wasrigen Sauren und Alkalien in der Hitze rasch hydrolytisch abgebaut. The conversion of dialkoxysilanes with cobaltous accetate results in insoluble and infusible products which are assumed to have a cross-linked structure. While silanediols do not react with cobalt halides, disodiumsilanediolates obtained from silanediols and sodium in liquid ammonia can be converted with cobaltous bromide to give polycobaltosiloxanes. The resultant resins are brittle, low-molecular weight products which are soluble in organic solvents but infusible. Cocondensation with aluminum chloride increases the viscosity number of the products without affecting the other properties to a noticeable extent. While trisodiumsilanetriolates and cobaltous bromide furnish insoluble and infusible products, the stepwise cocondensation of the triolates with cobaltous bromide and dichlorosilanes leads to soluble resins (melting range between 100 and 150°C.) which are assumed to have a strand-like structure. All polycobaltosiloxanes are of high thermal stability. However, they are rapidly hydrolysed by aqueous acids or alkalies at elevated temperatures.
Quality factor of a superfluid 3He weak link resonator

Abstract We measure the quality factor, Q for an oscillating membrane, which is in parallel with a superfluid 3He weak link array. We have constructed an effective cell model to help explain these results and find reasonable agreement between the experimental data and our theoretical model. The familiar effects of first and second viscosity have been considered as well as a new intrinsic dissipation that acts as a linear shunt conductance G across the weak link. Although the viscous terms dominate, as seen in single orifice weak links [1] , the “shorting” effects of the shunt conductance noticably suppress the quality factor, especially at low temperatures.
Photooxidative Cleavage of Organosilanes

Abstract Avoiding energy wasting return electron transfer reactions remains a central challenge in the design of high efficiency photoinduced electron transfer processes. One strategy for achieving this goal is to utilize compounds which as a result of electron transfer undergo rapid and irreversible chemical reaction in competion with the return electron process. Organosilanes represent a promising class of compounds that may fulfill this requirement. We have found that some organosilanes undergo rapid carbon-silicon bond cleavage when oxidized to their radical cations in photoinduced electron transfer reactions. Interestingly, these radical cation cleavage reactions occur by a rare nucleophile-assisted mechanism. We have investigated the reactivity of different classes of nucleophiles, and have determined the activation parameters for several of these reactions.
Photography of the Earth's Cloud Satellites from an Aircraft

Photography from aircraft of cloud-like objects in vicinity of libration points L4 and L5 of earth- moon system
Location and preservation of the parathyroid glands

Abstract The danger of parathyroid injury is more likely than has been admitted. An injury to the parathyroid glands is unavoidable in certain instances due to their anatomical position in the thyroid tissue. It is relatively easy to avoid injury to the recurrent laryngeal nerve but not so easy to avoid injury to one or more parathyroids. One should remember that the blood supply to the parathyroid glands is derived from the inferior thyroid artery. For that reason the exposure and division of the inferior thyroid vessels should be the first step of a thyroidectomy. A technique is illustrated which aids in the location and preservation of the parathyroid glands.
Palmitate transport across perfused human placenta.

Abstract Simultaneous in vitro perfusions of the maternal and fetal circulations of human term placentas showed significant transport of palmitate from the maternal to the fetal side. Transport of palmitate in the reverse direction took place if a large fetal:maternal concentration gradient was established. When the fetal and maternal perfusates contained identical amounts of palmitate, or a slightly higher concentration of palmitate on the fetal side, the transport favored the maternal-to-fetal direction. The “uphill” transport against a concentration gradient probably represents active transport by the placenta. The observed transport of radioactive palmitate was not due to the passage of labelled break down products, since the transported tracer moved with the free fatty acids on thin layer chromatogram. The integrity of the two vascular systems was monitored by retention of the indicator, bromosulphonphtalein. This excluded the possibility that the apparent transport was due to the leakage of the perfusate from one circulation to the other.
Pituitary uterotrophic effect in the estrogen-dependent growth of the rat uterus.

Abstract Several groups of endocrine manipulated prepuberal and young adult female rats were studied with the purpose of estimating the pituitary contribution to the uterine growth after a single injection of a physiological dose (1 μg/kg of body weight) of estradiol-17β (E 2 ). The different groups of E 2 and vehicle-injected animals included (a) castrated and (b) hypophysectomized and castrated (hypox) animals. In addition to these groups, a third represented by (c) hypox young adult female C 8 11RAP pituitary tumor-bearing rats were also studied to check whether this tumor behaves as the in situ pituitary present in castrated-only female rats. Results indicate that the pituitary of castrated rats and the rat pituitary tumor growing in the hypox rats significantly influence the increase of the wet and dry weights of the uterus following E 2 stimulation. It is proposed that there are uterotrophic factors in the pituitary and in the rat pituitary tumor tested.
The competition between heterogeneous surface growth and end-seeded directional growth during up-gradient crystallization

Abstract The up-gradient crystallization technique is considered in detail with particular emphasis on the effect that any adventitious surface nucleation might have on the final microstructure. As a worst-case analysis for the derivation, it has been assumed that this heterogeneous crystallization happens at all locations on the surface and in a variety of orientations. This derivation has been carried out for materials exhibiting either isotropic or anisotropic growth velocity behavior. For some controlled cases (either isotropic growth materials or directional growth in the fast growth direction) then the shell of poorly oriented material will be less than or equal to V 0 mG , where V 0 is the translation velocity, G is the temperature gradient used and m is a proportionality constant associated with the temperature dependence of the growth rate. The derivation also shows that directional crystallization of slow growth orientations can only succeed by completely preventing heterogeneous nucleation at the surface of the sample.
An Evaluation of Growth-Center Theory and Practice

This paper examines empirical and theoretical issues associated with the growth-center approach to regional development, and argues that despite many difficulties the major themes of the growth-cen...
Aldosterone metabolism and transepithelial potential difference in normal and cystic fibrosis subjects.

ABSTRACT: The transepithelial potential difference (PD) is raised across cystic fibrosis (CF) respiratory epithelia. This raised voltage reflects active sodium absorption across a relatively chloride impermeable membrane. Because relatively little is known about the regulation of the rate of sodium absorption across mammalian airways, we assessed the possible contribution of aldosterone to the PD in normal and CF respiratory epithelia. Aldosterone excretion in five CF patients was 12.2 ± 0.9 μg/24 h, a mean value not different from normal control subjects (13.6 ± 1.5 μg/24 h, n = 5). Despite similar aldosterone excretion rates, nasal PD was more than 2-fold greater in the CF patients (-53.6 ± 6.4 mV) than normal subjects (-21.3 ± 1.4 mV). The effect of an aldosterone antagonist, spironolactone, on aldosterone excretion and nasal and rectal PD was evaluated in four CF patients and five normal subjects. During spironolactone administration, aldosterone excretion increased (2− to 4-fold) and rectal PD decreased in both groups. However, nasal PD was unchanged in each group (CF = −52.1 ± 4.3 mV pre, −53.6 ± 1.4 mV during; normal = −21.2 ± 3.1 mV pre, −21.6 ± 3.2 mV during). We conclude that neither increased aldosterone secretion rates nor organ sensitivity to aldosterone can account for the abnormally raised PD that characterizes the respiratory epithelium of subject with CF.
Expansion of the surgical Apgar score across all surgical subspecialties as a means to predict postoperative mortality.

Background A surgical scoring system, akin to the obstetrician's Apgar score, has been developed to assess postoperative risk. To date, evaluation of this scoring system has been limited to general and vascular services. The authors attempt to externally validate and expand the Surgical Apgar Score across a wide breadth of surgical subspecialties. Methods Intraoperative data for 123,864 procedures including all surgical subspecialties were collected and associated with Surgical Apgar Scores (created by the summation of point values associated with the lowest mean arterial pressure, lowest heart rate, and estimated blood loss). Patients' death records were matched to the corresponding score, and logistic regression models were created in which mortality within 7, 30, and 90 days was regressed on the Apgar score. Results Lower Surgical Apgar Scores were associated with an increased risk of death. The magnitude of this association varied by subspecialty. Some subspecialties exhibited higher odds ratios, suggesting that the score is not as useful for them. For most of the subspecialties the association between the Apgar score and mortality decreased as the time since surgery increased, suggesting that predictive ability ceases to be helpful over time. After adjusting for the patient's American Society of Anesthesiologists classification, Apgar scores remained associated with death among most of the subspecialties. Conclusion A previously published methodology for calculating risk among general and vascular surgical patients can be applied across many surgical services to provide an objective means of predicting and communicating patient outcomes in surgery as well as planning potential interventions.
Characterization of chemical processes

Efficient control of complex chemical processes can be most easily implemented when the process is characterized. However, for most chemical systems this is difficult if not impossible because of the lack of adequate chemical information and the complexity of the interrelationships between the many variables in the process. The control of the processes is usually further hampered by the lack of on-line chemical instrumentation. As a result, most process control schemes are the result of ad hoc solutions where the control coefficients have an unknown relationship to the physical parameters being controlled.
Nickel(II) complexes of N-salicylideneamino acids

Abstract The preparation, spectral, and magnetic properties of nickel(II) complexes of N-salicylideneamino acids are described. The electronic spectra and magnetic properties support a dimeric octahedral structure for the complexes.
Ultra thin films of diblock copolymers under shear

The behavior of thin films of diblock copolymers under shear has been studied using coarse-grained Langevin dynamics simulations. The morphologies the film exhibits are examined as functions of composition, segregation strength, and the strength of the shear field. Below the order-disorder transition (ODT) the film generates a rich variety of structures corresponding to a monolayer of compressed micelles. Once a shear field is applied and above a critical shear rate, the system self-assembles into cylindrical micelles with orientation parallel to the shear direction, in agreement to experimental observations. In addition to formation of cylinders parallel to the sheared direction, we have identified the conditions under which cylinders under the influence of shear flow adopt an orientation perpendicular to the shear flow. The segregation strength is the main parameter that triggers the order-order steady state orientation transition.
The Politics of Risk: A Human Rights Paradigm for Children’s Environmental Health Research

A human rights paradigm for environmental health research makes explicit the relationship between poor health and poverty, inequality, and social and political marginalization, and it aims at civic problem solving. In so doing, it incorporates support for community-based, participatory research and takes seriously the social responsibilities of researchers. For these reasons, a human rights approach may be better able than conventional bioethics to address the unique issues that arise in the context of pediatric environmental health research, particularly the place of environmental justice standards in research. At the same time, as illustrated by disagreements over the ethics of research into lead abatement methods, bringing a human rights paradigm to bear in the context of environmental health research requires resolving important tensions at its heart, particularly the inescapable tension between ethical ideals and political realities.
CO2 adsorption performance for amine grafted particulate silica aerogels

Abstract A series of amine grafted CO 2 sorbents were prepared by functionalizing mono, di, and tri-amine substituted trialkoxysilanes on a particulate silica aerogel manufactured by Cabot Corp. The CO 2 adsorption performance, textural properties, and the nitrogen content of the functionalized aerogels were investigated using CO 2 gravimetric adsorption analysis, nitrogen porosimetry, and CHN elemental analysis. The synthesis variables involved in the grafting procedure were studied independently toward obtaining a high performing CO 2 capture sorbent. Of the mono, di, and tri-amine silanes, the tri-amine grafted aerogel obtained the highest adsorption capacity and was further investigated to determine the effects of synthesis conditions on adsorption performance. For anhydrous (dry) grafting the optimum conditions for the silica aerogel was 95 °C and a 2:1 silane:silica ratio that resulted in an adsorption capacity of 1.76 mmol/g. For hydrous (wet) grafting the optimum temperature was 95 °C and a water addition of 300 mg H 2 O/g of silica where the sorbent achieved a capacity of 2.61 mmol/g. The same sorbent also showed excellent cyclic stability maintaining a working capacity of 2.30 mmol/g for 100 cycles.
Current status and future directions of molecular markers in renal cell carcinoma.

Purpose of review To describe the existing data regarding the prognostic and/or predictive value of molecular markers in metastatic renal cell carcinoma. Recent findings Several molecular markers have been investigated in metastatic renal cell carcinoma for prognostic and/or predictive potential, many of which relate to pathogenic molecular alterations that are now therapeutic targets. Carbonic anhydrase IX is a von Hippel-Lindau (VHL)-mediated enzyme expressed in the majority of renal cell carcinoma tumors. High (>85%) expression of carbonic anhydrase IX in renal cell carcinoma tumors is a favorable prognostic marker and may predict response to interleukin-2 therapy. B7-H1 is a glycoprotein with inhibitory effects on T cells. B7-H1 expression in renal cell carcinoma tumor cells and/or lymphocytes may confer a worse survival in renal cell carcinoma patients, perhaps through impairment of inherent host of antitumor immunity. VHL pathway elements, including VHL gene status and expression of vascular endothelial growth factor protein and receptor, represent a promising area of investigation to predict responses to vascular endothelial growth factor-targeted agents. Prognostication schemas are beginning to incorporate molecular markers with clinical variables to refine the prediction of patient outcome. Summary Several molecular markers appear promising to refine prognosis and prediction in metastatic renal cell carcinoma. Further prospective evaluation is needed.
Heat Stability of Lipases of Selected Psychrophilic Bacteria in Milk and Purdue Swiss-Type Cheese

Abstract Differences in heat stability of lipase produced by Ps. fragi, Ps. mucidolens, and Ps. fluorescens were demonstrated. The enzyme produced by Ps. fluorescens was inactivated using the commercial heat treatment applied to milk, whereas the enzymes produced by Ps. fragi and Ps. mucidolens were more heat-stable and caused problems in Purdue Swiss-Type Cheese, making it unmarketable due to the off-flavor developed.
Purification to apparent homogeneity of a mu-type opioid receptor from rat brain

A mu-opioid-specific receptor was purified to apparent homogeneity from rat brain membranes by 6-succinylmorphine affinity chromatography, gel filtration, wheat germ agglutinin affinity chromatography, and isoelectric focusing. The purified receptor had a molecular weight of 58,000 as determined by NaDodSO4/polyacrylamide gel electrophoresis and was judged to be homogeneous by the following criteria: (i) a single band was detected by autoradiography after NaDodSO4/polyacrylamide gel electrophoresis of 125I-labeled receptor and (ii) the purified preparation had a specific opioid-binding activity of 17,720 pmol/mg of protein, close to the theoretical value. In addition, the Mr 58,000 value agrees closely with that determined by covalently labeling purified receptor with bromoacetyl-[3H]dihydromorphine or with 125I-labeled beta-endorphin and dimethyl suberimidate.
Privileged Emotion Managers: The Case of Actors:

Theatre1 provides a unique set of conditions for the management of emotions. Drawing on participant observation from one repertory theater, three university productions, and interviews with stage actors, directors, and acting instructors, I conceptualize actors as privileged emotion managers. Actors access structural resources that enable their ability to manage feelings onstage. Theatre's division of labor, the rehearsal process, and formal training give actors important advantages in managing emotions compared to many other social settings, and demonstrate structural recognition of and support for feeling management. These structures outsource some of an actor's emotion management and provide a set of institutionally prescribed strategies that actors use to manage feelings during a production.
Survival after liver transplantation in the United States: A disease‐specific analysis of the UNOS database

Our goal was to describe disease-specific survival and the clinical variables that predict survival in a large national cohort of adult liver transplant recipients. Data on 17,044 adult patients who received an initial orthotopic liver transplant between 1990 and 1996 with follow-up through 1999 was obtained from the United Network for Organ Sharing (UNOS). Disease-specific Kaplan-Meier survival plots and Cox Proportional Hazards models were estimated, and differences in the clinical characteristics of patients at the time of transplantation by disease were examined. Overall posttransplant survival currently exceeds 85% in the first year and is approaching 75% at 5 years. Unadjusted Kaplan-Meier survival is improved for recipients who are younger, female, and in better clinical condition. Survival is a function of disease and level of illness: cancer, fulminant liver failure, alcoholic liver disease, and the hepatitidies have the poorest prognosis, while primary billiary cirrohsis and sclerosing cholangitis have the best. Recipients who were outpatients before transplantation have longer survival than those transplanted from the hospital or intensive care unit. Although the model for end-stage liver disease (MELD) score was designed to predict pretransplant survival, patients with higher MELD scores have poorer posttransplant survival, but the MELD score is less predictive than the specific disease. Differences in disease-specific survival are partially explained by differences in disease severity at the time of transplantation. In conclusion, Disease-specific survival models indicate that there remains tremendous variability in survival as a function of underlying liver disease. However, a significant portion of the difference in survival between diseases arises from differences in clinical characteristics at the time of transplantation.
Factitious disease of the breast of a male due to injection of liquid plastic.

Background Factitious disease involving the breast is unusual. The rarely reported cases of this entity have been encountered in middle-aged women. In general, factitious disease can be distinguished on clinical and/or psychological grounds from self-induced disorders seen in malingerers and among those demonstrating Munchausen's syndrome. Methods We report herein a male patient displaying factitious disease of the breast due to injection of a high viscosity liquid plastic material. Results Establishment of the proper diagnosis was greatly delayed due to a lack of suspicion of this entity. Only direct confrontation of the patient with the biopsy results (lipogranulomatosis) led to a reluctant and then only partial admission of the self-induced nature of this patient's illness. Conclusion The clinician should remain vigilant for factitious disease when confronted with chronic or recurrent lesions of a bizarre or atypical morphology. Any body site can be involved, including the breast. Management is difficult and is best accomplished in conjunction with an appropriate mental health professional. Continued dramatic surgical interventions are contraindicated.
The Myxococcus xanthus lipopolysaccharide O‐antigen is required for social motility and multicellular development

The gliding bacterium Myxococcus xanthus aggregates to form spore-filled fruiting bodies when nutrients are limiting. Defective fruiting-body formation and sporulation result from mutations in the sasA locus, which encodes the wzm wzt wbgA (formerly rfbABC) lipopolysaccharide (LPS) O-antigen biosynthesis genes. Mutants carrying these same sasA mutations are defective in social motility and form small glossy colonies. We report here that the developmental and motility phenotypes of four mutants each containing different Tn5 insertions in LPS O-antigen biosynthesis genes are similar to those of the original sasA locus mutants. All of the LPS O-antigen mutants tested exhibited defective developmental aggregation and sporulated at only 0.02-15% of the wild-type level. In addition, all of the LPS O-antigen mutants were determined by genetic analyses to be wild type for adventurous motility and defective in social motility, indicating that the LPS O-antigen is necessary for normal development and social motility. The two previously identified cell-surface components required for social motility, type IV pili and the protein-associated polysaccharide material termed fibrils, were detected on the surfaces of all of the LPS O-antigen mutants. This indicates that LPS O-antigen is a third cell-surface component required for social motility.
Fine‐needle aspiration cytology of mucinous tumors of the pancreas

BACKGROUND Tumors of the pancreas associated with extracellular mucin production include mucin-producing ductal adenocarcinoma, mucinous cystic neoplasm (MCN), and intraductal papillary mucinous tumor (IPMT). Fine-needle aspiration (FNA) is used as an adjunct to radiologic analysis for the preoperative categorization of these tumors. The current study was designed to identify distinctive cytomorphologic features that would be useful for the categorization of mucinous tumors of the pancreas. METHODS The authors evaluated Papanicolaou smears and Diff-Quik-stained smears of specimens obtained by computed tomography-guided and endoscopic ultrasound-guided FNA of the pancreas in 51 cases of mucinous tumors. In the 19 cases in which the patients underwent surgical excision after FNA, the cytologic features were compared with the histopathologic findings. The remaining cases were categorized as one of the three above-mentioned types of mucinous tumors on the basis of cytomorphologic features identified as indicative of subtype among the cases in which a cytologic-histologic correlation was performed. RESULTS Among the 19 cases with cytologic-histologic correlation, 2 cases of serous cystadenoma and 2 cases of gastrointestinal duplication cyst were misdiagnosed on cytologic analysis as low-grade MCN. Among the remaining 15 cases, cytologic features by histologic diagnosis were as follows: ductal adenocarcinoma (n = 4): moderate to high cellularity, mild to moderate background mucin, three-dimensional clusters, high nuclear cytoplasmic ratios, and mild to moderate nuclear membrane irregularities; low-grade MCN (n = 5): mild to moderate cellularity, abundant background mucin, small clusters, and flat sheets of relatively bland glandular cells; mucinous cystadenocarcinoma (n = 1): similar to ductal adenocarcinoma but more abundant background mucin; and IPMT (n = 5): moderate to high cellularity, abundant background mucin, and prominent papillary arrangement of tall columnar cells with mild to moderate nuclear atypia. The remaining 32 cases were categorized based on cytology alone as adenocarcinoma with mucin production (n = 24) and low-grade MCN (n = 8). CONCLUSIONS IPMT and low-grade MCN possess distinctive cytologic features that can be used to diagnose them correctly and distinguish them from one another and from other cystic tumors. Duplication cysts closely mimic low-grade MCN, which can lead to false-positive diagnoses. Because of substantial overlap in cytologic features, mucin-producing ductal adenocarcinoma was unable to be distinguished from mucinous cystadenocarcinoma cytologically. Cancer (Cancer Cytopathol) 2004;102:000–000. © 2004 American Cancer Society.
Vasopressin decreases portal vein pressure and flow in the native liver during liver transplantation

Vasodilation due to impaired vascular tone is common in liver failure. Vasoconstrictor drugs are almost always required during the anhepatic phase of a liver transplant to maintain blood pressure unless venovenous bypass is employed. Arginine-vasopressin can be used as a vasoconstrictor instead of or in addition to norepinephrine for this purpose, but the effect of vasopressin on the portal vein pressure and flow in this setting is unknown. Portal vein pressure, portal vein blood flow, hemodynamic variables, and plasma vasopressin levels were measured in 16 patients during liver transplantation after ligation of the hepatic artery before and after a vasopressin infusion of 3.8 +/- 1.1 units/hour. Measurements were performed on the native liver prior to caval clamping. After vasopressin infusion, the portal vein pressure decreased significantly from 24.0 +/- 6.5 to 21.5 +/- 7.4 mm Hg [mean +/- standard deviation (SD), P = 0.006]. The portal vein blood flow also decreased (from 1.01 +/- 0.53 to 0.76 +/- 0.53 L/minute, mean +/- SD, P < 0.0001), as did the portal vein blood flow to cardiac output ratio (from 0.14 +/- 0.06 to 0.10 +/- 0.07, mean +/- SD, P < 0.0001). In conclusion, vasopressin significantly decreased portal vein pressure and flow of the native liver without decreasing cardiac output or intestinal perfusion in patients undergoing liver transplantations.
Unusual shapes for a catenary under the effects of surface tension and gravity: A variational treatment

The familiar catenary is the shape assumed by a chain or string as it hangs from two points. The mathematical equation of the catenary was first published more than three hundred years ago by Leibnitz and Huygen, among others. Here we consider the shapes assumed by a hanging string in the presence of gravity and surface tension. The surface tension is introduced by suspending the string from a thin horizontal rod while the area bounded by the string and the rod is covered with a soap film. The string then assumes new and wonderful shapes depending on the relative strength of the surface tension and the weight per unit length of the string. When surface tension dominates, the string is pulled inward, assuming a convex shape similar to the Greek letter [gamma]. On the other hand, when gravity is dominant the string is pulled outward and assumes a concave shape best described as a distorted catenary. However, when the gravitational force normal to the string matches the surface tension, the string takes a linear configuration similar to the letter [ital V]. Under suitable conditions, the string can be made to assume any of the three configurations by adjusting the separationmore » of its end points. The equations that describe the shape of the string are derived by minimizing the total energy of the system and are presented for the three principal configurations.« less
Approximate confidence intervals for the correlation from data in two-by-two tables

The family of power divergence statistics is used to construct approximate confidence intervals for the correlation between two variables from data in 2×2 tables. This family includes confidence intervals obtained by inverting the likelihood ratio, Pearson chi-squared and Freeman–Tukey statistics. Small-sample calculations show that several power divergence intervals, and in particular the confidence interval constructed from the Pearson chi-squared statistic, have coverage probabilities closer to nominal levels than the interval based on the normal approximation to the tetrachoric correlation coefficient.
Determination of residue-specific acid dissociation constants for peptides by band-selective homonuclear-decoupled 1H NMR

Acid dissociation constants of side-chain acidic groups of amino acid residues in peptides can be determined by 1H NMR, provided resonances can be resolved for carbon-bonded reporter protons located near the acidic group. We report here that the increased resolution of the band-selective homonuclear-decoupled (BASHD) TOCSY experiment greatly extends the range of application of the NMR method for determination of residue-specific, side-chain acid dissociation constants of peptides that contain multiple residues of the same amino acid. Chemical shift−pH titration curves are obtained from cross-peaks for reporter protons in BASHD-TOCSY spectra measured as a function of pH. The method is based on using sequence-dependent differences in the chemical shifts of resonances for the backbone CαH protons and the increased resolution in BASHD-TOCSY spectra from collapse of CαH multiplets to singlets in the F1 dimension to resolve resonances for the side-chain reporter protons. Application of the method is demonstrate...
EFFECTS OF GROUP AND RELATIONSHIP ON PERCEPTIONS OF STABILITY

Summary.-Introductory psychology students, 52 men and 52 women, made estimates of the consistency of a decision-maker in 24 hypothetical social influence situations. The decision-maker was either a group or an individual, and the petitioner who was attempting to influence a change in decisions was in either a weak or equal status relationship with the decision-maker. As hypothesized, subjects predicted that group decision-makers would be less likely to change than would individual decision-makers. Subjects also predicted greater consistency on the part of the decision-maker when the petitioner was weak than when he was equal in status with the decision-maker. There were interaction effeccs of sex of subject and sex of characters on stability predictions. Persons acting in groups behave differently than do persons acting as individuals. Persons in groups yield to others in making judgments (Asch, 1956) and are, among other things, less innovative (Dunnette, Campbell, & Jaastad, 1963), less likely to aid in emergencies (Darley & Latane, 1968), more extreme in judgments involving valued choices (Schroeder, 1973), and less trustworthy (Lindskold, Gahagan, & Tedeschi, 1969) than are individuals. Since group behavior is different from individual behavior, naive persons should have differing perceptions of groups and individuals and should make different predictions about the future actions of groups and of individuals. Kelley (1967) holds that attributions regarding persons will be more stable when those persons act consistently over time, over persons, and over modalities. A group's decision, once made, automatically provides some measure of consistency over persons (consensus) which is, of course, unattainable when only one person is making a decision. In turn, a series of group decisions may provide consistency over both time and persons, while a series of decisions by an individual provides consistency over time only. From this viewpoint, a series of group decisions permits a more stable set of attributions and more firm expectations for the group's future action, than does a series of similar decisions made by an individuaL Price and Lindskold' placed individual subjects in a modified Prisoner's Dilemma game in which they were to participate as though the other player were either a single individual or a group of three people. For some subjects the opponent was competitive, for other subjects the opponent was benevolent and
Beta: Misconceptions and Limitations

Beta quantifies the expected volatility of an asset as it relates to the volatility of an index with which it is compared (usually the S&P 500). While this is important information about the behavior of an asset, equally important is whether the asset can be expected to move, over time, in the same direction as the index. Beta gives no information about the trend of an asset with respect to the trend of the index. In fact, calculation of beta explicitly removes the trend, so has no dependency on it. The author gives examples of an asset that is trending up with the index but has a beta of -1.0 and an asset that is trending down but has a beta of +1.0, and then shows how to calculate a price sensitivity that relates the trend of an asset to the trend of the index. Combining beta and price sensitivity gives a much better picture of the expected investment characteristics.
PRECLASSIC MAYA OCCUPATION OF THE ITZAN ESCARPMENT, LOWER RÍO DE LA PASIÓN, PETÉN, GUATEMALA

Maya elites and commoners intensively occupied the Itzan escarpment, located in the lower Rio de la Pasion drainage system of Peten, Guatemala, during the Preclassic and Protoclassic periods. Itzan was colonized during the Xe phase of the Middle Preclassic period, and its occupation intensified during the late Middle and Late Preclassic periods, when elite residential and ceremonial facilities were erected. During the Late Preclassic and Protoclassic periods, the escarpment was dominated by Chaak Ak'al, a large site distinguished by massive pyramids and lengthy wall-like constructions, which undoubtedly served as a polity capital. Subsequent to the Protoclassic period, the locus of activity atop the escarpment shifted back to Itzan, which served as a polity capital through the Late Classic period. From data collected at Itzan, Chaak Ak'al, and other sites of the lower Rio de la Pasion drainage system, a picture of regional Preclassic Maya political geography is emerging.
Baseball and Softball Sliding Injuries. Incidence, and the Effect of Technique in Collegiate Baseball and Softball Players

We prospectively observed seven softball and three baseball Division I collegiate teams to study the incidence of sliding injuries, the types of injuries resulting from the sliding technique, and the amount of time lost from participation. Slides were categorized as either feet- or head-first on the basis of the leading part of the body during the slide. Slides were further stratified depending on whether a diveback technique was performed. We recorded 37 injuries in 3889 slides in 637 games and 7596 athlete game exposures. The overall incidence of sliding injuries was 9.51 per 1000 slides and 4.87 per 1000 game exposures. Softball players had a significantly higher incidence of sliding injuries (12.13 per 1000 slides) than did baseball players (6.01 per 1000 slides). In baseball, the injury rate was higher for feet-first slides (7.31 per 1000 slides) than for headfirst slides (3.53 per 1000 slides) or divebacks (5.75 per 1000 divebacks). In softball, injury rates were higher for head-first slides (19.46 per 1000 slides) than for feet-first slides (10.04 per 1000 slides) or divebacks (7.49 per 1000 divebacks). The majority of injuries sustained were minor, with only four (11%) injuries causing the athlete to miss more than 7 days of participation.
Assembly of the Trypanosoma brucei 60S Ribosomal Subunit Nuclear Export Complex Requires Trypanosome-Specific Proteins P34 and P37†

We previously identified two Trypanosoma brucei RNA binding proteins, P34 and P37, and determined that they are essential for proper ribosomal assembly in this organism. Loss of these proteins via RNA interference is lethal and causes a decrease in both 5S rRNA levels and formation of 80S ribosomes, concomitant with a decrease in total cellular protein synthesis. These data suggest that these proteins are involved at some point in the ribosomal biogenesis pathway. In the current study, we have performed subcellular fractionation in conjunction with immune capture experiments specific for 60S ribosomal proteins and accessory factors in order to determine when and where P34 and P37 are involved in the ribosomal biogenesis pathway. These studies demonstrate that P34 and P37 associate with the 60S ribosomal subunit at the stage of the nucleolar 90S particle and remain associated subsequent to nuclear export. In addition, P34 and P37 associate with conserved 60S ribosomal subunit nuclear export factors exportin 1 and Nmd3, suggesting that they are components of the 60S ribosomal subunit nuclear export complex in T. brucei. Most significantly, the pre-60S complex does not associate with exportin 1 or Nmd3 in the absence of P34 and P37. These results demonstrate that, although T. brucei 60S ribosomal subunits utilize a nuclear export complex similar to that described for other organisms, trypanosome-specific factors are essential to the process.