cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural response of relaxed and constricted arterioles

Abstract Analysis of viscoelastic properties of blood vessel walls presents difficult analytical problems in view of their non-homogeneity, anisotropy, and non-linear viscoelastic characteristics. The analytical technique used in this study is the numerical method of direct stiffness which has been successfully applied in preliminary studies. The direct stiffness method constitutes a finite element analysis, where the wall structure in an electron micrograph is represented by an assembly of triangular elements. Different material properties can be assigned to each triangular element; the method is thus ideally suited for computer analysis of non-homogeneous biological structures. Anatomical components considered in the analysis were two types of collagen fibers and smooth muscle cells. Typical circumferential stress-time and radius-time histories for selected points have been obtained in relaxed and constricted arterioles under static pressure loads. Plots of the stress distribution in cross sections of the vessel wall have been obtained in relaxed and constricted arterioles.
Optimal strategies in MAC protocols

We have analyzed the distributed MAC protocols by using game theoretic concepts. Specifically, we have modelled the "access" game as a non-cooperative game with incomplete information. We have proven the existence of optimal strategies for individual users. We have derived approximate formulae for optimal transmission probabilities in two cases: single class of users and two classes of users.
p53 mutations do not predict response to paclitaxel/radiation for nonsmall cell lung carcinoma.

BACKGROUND Mutations in the tumor suppressor gene p53 have been associated with resistance to ionizing radiation and chemotherapy. Paclitaxel and concurrent radiation (paclitaxel/RT) achieve high response rates with locally advanced nonsmall cell lung carcinoma (NSCLC). In vitro data and animal studies suggest that paclitaxel may have a unique ability to activate tumor cell apoptosis in the absence of wild-type p53 function. The authors sought to determine whether p53 mutations affect response to paclitaxel/RT in patients with locally advanced NSCLC. METHODS Thirty patients with Stage IIIA or IIIB NSCLC who participated in Brown University Oncology Group protocols utilizing paclitaxel/RT had tumor tissue that was adequate for analysis. Mutations were detected in tumor tissue by single-strand conformation polymorphism analysis of exons 5 through 8 of the p53 gene, and confirmed by direct sequencing. RESULTS Mutations in p53 were found in 12 of 30 patients (40%). The response rates (complete plus partial) of 75% for patients with tumors with p53 mutations, and 83% for patients with wild-type p53, did not differ significantly (P = 0.70). CONCLUSIONS p53 mutations do not predict response of patients with NSCLC to paclitaxel/RT. This finding is in striking contrast to results with other chemotherapeutic agents and ionizing radiation. These clinical data support in vitro data and animal studies regarding the unique mechanism of the action of paclitaxel. Further investigation is needed to determine the mechanism of lung tumor cell death after paclitaxel/RT. These results suggest that paclitaxel/RT may be an active regimen for patients with other locally advanced neoplasms with high rates of p53 gene mutations. Cancer 1996;78:1203-10.
Recent efforts to validate EOS observations: hyperspectral data noise characterization using PCA: application to AIRS

Exploiting the redundancy in high spectral resolution observations, dependent set Principle Component Analysis (PCA) is a simple yet very powerful tool not only for noise filtering and lossy compression, but also for the characterization of sensor noise and other variable artifacts using Earth scene data. Our approach for dependent set PCA of AIRS Earth scene data is presented. Aspects of the analyses include 1) estimation of NEDT using PCA and comparisons to values derived from on-board blackbodies, 2) estimation of the scene dependence of NEDN, 3) estimation of the spectrally correlated component of NEDT and comparison to pre-launch analyses using blackbody views, 4) investigation of non- Gaussian noise behavior, and 5) inspection of individual PCs. The results of the PCA analyses are generally consistent with results obtained pre-launch and on-orbit using blackbody and/or space view data. Specific findings include: 1) PCA estimates of AIRS spectrally random and spectrally correlated NEDN compare well with estimates computed from on-board blackbody and space views, 2) the signal dependence of AIRS NEDN is accurately parameterized in terms of the scene radiance, 3) examination of the reconstruction error allows non-Gaussian phenomenon such as popping to be characterized, and 4) inspection of the PCs and individual PC filtered radiance spectra is a powerful technique for diagnosing low level artifacts in hyperspectral data.
Calculated Hydride Donor Abilities of Five-Coordinate Transition Metal Hydrides [HM(diphosphine)2]+ (M = Ni, Pd, Pt) as a Function of the Bite Angle and Twist Angle of Diphosphine Ligands

Density functional theory (BLYP and B3LYP) and the polarized continuum model (PCM-UA0) for solvation have been used to investigate the effect of bite angle (P−M−P) of diphosphine ligands and the dihedral or twist angle between diphosphine ligands on the hydride donor abilities of Ni, Pd, and Pt [HM(diphosphine)2]+ complexes. It is found that an increased bite angle for a given transition metal atom results in poorer hydride donor abilities. However, hydride donor abilities for these complexes also decrease as the size of the alkyl side groups on the phosphorus atom increase (Et > Me > H) and with the length of the metal phosphorus bond (Ni > Pd ≅ Pt). These trends correlate with an increase in the twist angle between the two diphosphine ligands, which increases from 0° for a square-planar configuration to 90° for a tetrahedral geometry. Shorter M−P bonds, larger substituents on the diphosphine ligands, and larger bite angles all result in increased steric interactions between diphosphine ligands and large...
Parasite maturation and host serum iron influence the labile iron pool of erythrocyte stage Plasmodium falciparum.

Iron is a critical and tightly regulated nutrient for both the malaria parasite and its human host. The importance of the relationship between host iron and the parasite has been underscored recently by studies showing that host iron supplementation may increase the risk of falciparum malaria. It is unclear what host iron sources the parasite is able to access. We developed a flow cytometry-based method for measuring the labile iron pool (LIP) of parasitized erythrocytes using the nucleic acid dye STYO 61 and the iron sensitive dye, calcein acetoxymethyl ester (CA-AM). This new approach enabled us to measure the LIP of P. falciparum through the course of its erythrocytic life cycle and in response to the addition of host serum iron sources. We found that the LIP increases as the malaria parasite develops from early ring to late schizont stage, and that the addition of either transferrin or ferric citrate to culture media increases the LIP of trophozoites. Our method for detecting the LIP within malaria parasitized RBCs provides evidence that the parasite is able to access serum iron sources as part of the host vs. parasite arms race for iron.
Effect of Sodium Aluminosilicate, Oyster Shell, and Their Combinations on Acid-Base Balance and Eggshell Quality

Abstract Three experiments were conducted to determine the effect of sodium aluminosilicate (SAS), oyster shell (OS), and their combinations on production performance, eggshell quality, and acid-base balance. Experiments 1 and 2 were conducted during summer and Experiment 3 in winter. In Experiment 1, the effect of two levels of SAS (0 and .75%) and two levels of OS (0 and 50% substitution for pulverized limestone) was studied. In Experiment 2, the effect of SAS (.75%) with or without Na adjustment was investigated. When Na was adjusted, various sources of chloride were used to maintain an adequate level of this mineral. Calcium and available P were maintained at a constant 3.5 and .4%, respectively in Experiments 1 and 2. In Experiment 3, the levels of SAS and OS were similar to those of Experiment 1, but dietary Ca was either 2.8 or 3.5%. Egg production performance was not influenced by dietary treatments in Experiments 1 and 2 (P>.05). Egg production, but not egg mass, was reduced due to SAS in Experiment 3 (P .05). Blood acid-base balance, plasma Ca and P, bone ash, bone Ca, and Ca retention were not influenced by dietary treatments. The results suggest that elevated environmental temperatures may be required in order for SAS to show its optimum effect on shell quality.
Maximum likelihood estimation of mixture constants and locally optimal detection of contaminants

Abstract The problems of asymptotic M -estimation of mixture constants and local detection of the presence of contaminating distributions are considered. The asymptotic variance of consistent M -estimators is found and it is shown that this variance is minimized by the maximum likelihood estimate (MLE). Conditions are found for the consistency and asymptotic normality of M -estimators and it is shown that the MLE satisfies these conditions. The efficacy for a test designed to detect the presence of vanishingly small contaminants is defined. The detector which maximizes the efficacy is found and it is shown that the detector nonlinearity which maximizes the efficacy is the same as the MLE nonlinearity. Furthermore, it is shown that, as in the case of the MLE for location and the optimal small signal detector, the efficacy of the locally optimal detector and the asymptotic variance of the MLE are inversely related.
Nutrient-Use Efficiency: A Litterfall Index, a Model, and a Test Along a Nutrient-Availability Gradient in North Carolina Peatlands

The efficiency of using nutrients to produce new biomass may be an important adaptation of plants to infertile habitats. We distinguish resource-use efficiency (production per unit resource uptake) from resource-response efficiency (production per unit resource availability) and employ Monod functions to investigate changes in these two efficiencies along resource gradients. The model predicts increasing nutrient efficiency with decreasing nutrient availability or uptake to some optimum resource level, but further nutrient deficiency causes a decrease in nutrient efficiency. We tested this model along a natural fertility gradient in three North Carolina peatland communities, using the ratio of litterfall production to litterfall nutrient content as an index of nutrient-use efficiency and the ratio of litterfall production to various measures of soil nutrient pool size as an index of nutrient-response efficiency. The model did an excellent job of describing both nutrient efficiencies, and, as predicted, ef...
The Path Leading to Differentiation: An Interview with Carol Tomlinson.

The author interviewed Dr. Carol Tomlinson, who is a well-known academic scholar in gifted education. The interview focused on Dr. Tomlinson’s work on differentiation, how she started, and what her suggestions for teachers are to differentiate instructions for gifted students in general education classrooms.
Uniqueness theorem for an inverse scattering problem with non-overdetermined data

Let q(x) be a real-valued compactly supported sufficiently smooth function. It is proved that the scattering data A(− β, β, k) ∀β S2, ∀k > 0 determine q uniquely.
Rationale for the role of osteoclast-like cells in arterial calcification

Atherosclerotic arteries frequently become calcified, and these calcium deposits are associated with a high risk of adverse clinical events. Descriptive studies suggest calcification is an organized and regulated process with many similarities to osteogenesis, yet the mechanism and its relationship to atherosclerosis remain largely unknown. In bone development and homeostasis, mineral deposition by osteoblasts and mineral resorption by osteoclasts are delicately balanced such that there is no overall gain or loss in bone mass. We hypothesize that there exists in arteries a mechanism that similarly balances mineral deposition with resorption. We propose that the cellular mediators of arterial mineral resorption are osteoclast-like cells (OLCs) derived from hematopoietic precursors of the mononuclear phagocytic lineage. In arterial microenvironments, mononuclear precursors are induced to differentiate toward OLCs by macrophage-colony stimulating factor and receptor activator of NF-kappaB ligand, both of which are necessary and sufficient for osteoclastogenesis and mineral resorption in bone. OLCs may participate in normal mineral homeostasis within the arterial wall or, alternatively, may be recruited to specific sites within developing plaque. Net calcium deposition occurs as a result of focal perturbation of the balance between the activity of osteoblast-like cells and OLCs. Our proposed mechanism thus views arterial mineral deposition not so much as an active pathological process, but as a localized failure of protective mechanisms that actively oppose mineral deposition within the disordered metabolic milieu of developing atherosclerotic plaque.
The role of tumor associated macrophages in ovarian cancer

Objectives: The aim of this study was to determine differences in palliative care needs inwomenwith gynecologic cancers from anurban, inner city, academic facility compared to a suburban, community facility and also, to identify interventions that could improve palliative care for gynecologic cancer patients in varying locations. Methods: 71 women with gynecologic cancer were prospectively identified, 54 from an urban, inner city academic cancer center, and 17 from a suburban community cancer center in the same metropolitan area. All subjects were asked to complete a standardized, validated questionnaire intended to determine their palliative care needs after diagnosis but prior to treatment. Palliative care trained, Master's level social workers introduced themselves and the questionnaire to patients, and offered to help with additional needs. Completed questionnaires were collected and appropriate data was extracted. The data was depersonalized and analyzed by the authors. Statistical differences were assessed with SigmaStat V.2.0. Results: All patients were treated by board-certified gyn oncologists. The types of cancers seen and treatments offered (all of which met NCCN guidelines) were similar. Inner city academic patients were less likely to complete the questionnaire than the suburban community patients (64% vs 100% of those offered, p b 0.001). Patients from the inner city academic group were younger (54 years old vs 61 years old, p b 0.05) and more likely to be African–American (77% vs 29%, p b 0.05) than those from the suburban community group. The ratio of Medicaid to private/Medicare insurance coverage was higher in inner city academic patients than suburban community patients (58% vs 22%, p b 0.05). The most common palliative care concerns identified by suburban community patientswere: 1) pain, 2) anxiety, 3) depression, 4) nausea/vomiting. In comparison, the most common concerns identified by inner city academic patients were: 1) paying for medications, 2) travel to the treatment facility, 3) pain, and 4) child care. Conclusion: There are major differences in the palliative care needs of patients from an inner city academic facility compared to a suburban community facility. Interventions proposed for the suburban community facility were early access to: 1) grief counseling, 2) patient support groups, and 3) Nurse–Navigator services. Interventions proposed for the inner city academic facility include early access to: 1) programs for assistance with medication costs (local philanthropies, facility-based pharmacy discounts), 2) travel services (cab vouchers, coordination of treatments with public transportation schedules), and 3) on-site child care facilities. Further, inner city academic patients should be encouraged to voice their palliative care concerns. More specific determinations of patient concerns are needed to help structure palliative care services in different types of facilities.
SYSTEMATICS OF ANGULAR AND POLARIZATION DISTRIBUTIONS IN THREE-BODY DECAYS

A general method is described for the measurement of the polarization and alignment of a particle of arbitrary spin from the analysis of its three-body decays. This method provides a procedure for the determination of spin and parity of the decaying system which is independent of the dynamics of the decay process. The procedure is closely related to the one currently used for two-body reactions except that the normal to the decay plane replaces the center-of-mass momentum as an analyzer. The general formalism is developed and illustrated by two examples: three-pion decays and baryon-two-pion decays.
Organizational buyers and conflict: The impact of conflict on ongoing and new purchasing situations

Abstract Social conflict is endemic to all human activity. In this study, we examine how conflict, as perceived by professional buyers, impacts their ongoing relationships with current suppliers as well as its effect on developing new supplier relations. The results indicate that affective (personality) conflict between the parties has a negative impact on both the buyer's decisions in choosing a new supplier and their decision to continue an existing relationship with a supplier. The impact of cognitive (idea) conflict seems to be mixed. In ongoing relationships, there is no impact, but in new choice purchase situations, higher levels of cognitive conflict are related to lower probability of getting a sale. The findings also reveal that having an approved supplier list lessens the negative effects of cognitive conflict in ongoing supplier relations.
Resveratrol for ex vivo purging of hematopoietic autografts

Abstract Novel purging strategies that would selectively eliminate contaminating tumor cells without affecting the hematopoietic activity of progenitor cells are needed for ex vivo purging of autografts. In this study we demonstrate that resveratrol, a chemopreventive agent naturally present in grapes, exhibits antiproliferative activity against mouse and human leukemic cell lines. Long term exposure to resveratrol also inhibited the clonal growth of normal hematopoietic progenitor cells but at a higher IC 50 than the leukemia cell lines tested. The inhibitory effect of resveratrol on hematopoietic progenitors is reversible, whereas the effect on leukemia cells is largely irreversible. Resveratrol induced apoptosis in leukemia cells, but it neither induces or enhances the spontaneously occurring DNA fragmentation in normal progenitor cells. More importantly, in vivo experiments demonstrated that treatment of bone marrow cells with resveratrol does not impair their ability to engraft in lethally irradiated mice. Overall, these data indicate that resveratrol may be used for pharmacological purging of autografts without significant decrease in the hematopoietic activity of progenitor cells.
Extending the duration of active oral contraceptive pills to manage hormone withdrawal symptoms.

Objective To test the hypothesis that extending the number of consecutive active oral contraceptives (OC)s given will decrease the frequency of menstrual-related problems including dysmenorrhea, menorrhagia, premenstrual-type symptoms, and menstrual migraines. Methods A prospective analysis was designed to track the experiences of 50 women taking OCs and experiencing menstrual-related problems. Fifty consecutive patients, who were taking OCs and had symptoms during the pill-free interval, were followed in a multispecialty clinic by an individual physician and nurse practitioner team. The patients were permitted to extend the number of consecutive active OCs to delay menstrual-related symptoms. Results Immediate outcome of the 50 patients revealed 74% (37 patients) stabilized on an extended regimen of 6 to 12 weeks of consecutive days with active OCs. Twenty-six percent (13 patients) either discontinued OCs or returned to the standard regimen with 3 weeks of active pills. Of the 37 patients who were stabilized on an extended regimen, 27 have completed thus far between five and 13 extended cycles with 6–23 months of follow-up (mean 16 months). Conclusion Experience in a series of 50 OC users with menstrual-related symptoms demonstrated that delaying menses by extending the number of consecutive days of active pills is well tolerated and efficacious. We believe that a large prospective study is warranted to further our knowledge in this area.
Mössbauer-Effect Study of the Ferroelectric Transitions in Potassium Ferrocyanide Trihydrate and Ferric Ammonium Sulfate Dodecahydrate

The M\"ossbauer effect has been used to study the ferroelectric transitions in potassium ferrocyanide trihydrate (KFCT) and ferric ammonium sulfate dodecahydrate (FAS). The recoilless fraction and isomer shift of these materials have been observed as a function of temperature. For FAS, the absorption line-width was also observed. For FAS, the recoilless fraction $f$ and absorption linewidth $w$ were found to behave anomalously at the ferroelectric transition temperature ${T}_{c}$; $f$ exhibits a minimum at ${T}_{c}$, and $w$ has a maximum there. No change in the isomer shift was detected at the FAS transition. The behavior of $f$ is consistent with a description of the transition in FAS in terms of a "soft" transverse optical (TO) lattice mode of zero wave vector (${\ensuremath{\omega}}_{\mathrm{TO}}\ensuremath{\rightarrow}O$ at $T={T}_{c}$). For KFCT, no anomalous behavior of any M\"ossbauer-effect parameter was detected. This is contrary to a previous report by other workers of a maximum in $f$ near ${T}_{c}$ for KFCT. The lack of any anomaly in KFCT is consistent with an order-disorder model of the KFCT transition, but does not preclude one particular type of displacive transition.
‘Trailing Wife’ or ‘Trailing Mother’? The Effect of Parental Status on the Relationship between Family Migration and the Labor-Market Participation of Married Women

Numerous studies demonstrate that married women sacrifice their own careers in order to support their husbands' careers by following them as tied migrants, largely independent of their own occupational status. Thus, it appears as if family migration is shaped by the dominant gender roles and gender identities which configure the lives of women and men in married couple families. The motivation for this paper stems from a concern that family migration research has failed to consider that the effects of family migration on the labor-market participation of married women may be contingent on parental status. This research is designed to uncover the individual and joint effects of migration and parental status on married women's labor-market participation. The approach taken in this research is to begin with a very specific type of married couple family—married couple families without children—and to trace how the birth of the first child and migration events independently and jointly determine women's labor-...
Striatal D1- and D2-dopamine receptor sites are separately detectable in vivo

We have characterized in particulate fractions of normal rat striatum the in vivo binding kinetics, binding affinity, and pharmacological profiles of [3H]SCH 23390, a ligand selective for the D1-subtype of dopamine (DA) receptor, and compared these to [3H]spiperone, a ligand classically associated with the D2 DA receptor subtype. The pharmacological specificity of each ligand's in vivo binding is very similar to binding to striatal homogenates in vitro. While similar maximum numbers (Bmax) of striatal binding sites exist in vivo compared to in vitro for both ligands, binding affinities in vivo for both ligands are reduced 125- to 200-fold compared to in vitro. In vivo binding of [3H]SCH 23390 to striatum is not increased by dopamine denervation produced by 6-hydroxydopamine lesions of the nigrostriatal pathway. In vivo binding of [3H]SCH 23390 and [3H]spiperone to striatum is not significantly reduced by increased synaptic concentration of dopamine following d-amphetamine administration. 125I-SCH 23982, the iodinated analogue of SCH 23390, localizes very highly to dopaminergic forebrain areas following i.v. administration. External imaging of mammalian and human brain D1-receptors is potentially feasible with this ligand.
The Allantoic Core Domain: New Insights Into Development of the Murine Allantois and Its Relation to the Primitive Streak

The whereabouts and properties of the posterior end of the primitive streak have not been identified in any species. In the mouse, the streak's posterior terminus is assumed to be confined to the embryonic compartment, and to give rise to the allantois, which links the embryo to its mother during pregnancy. In this study, we have refined our understanding of the biology of the murine posterior primitive streak and its relation to the allantois. Through a combination of immunostaining and morphology, we demonstrate that the primitive streak spans the posterior extraembryonic and embryonic regions at the onset of the neural plate stage ( approximately 7.0 days postcoitum, dpc). Several hours later, the allantoic bud emerges from the extraembryonic component of the primitive streak (XPS). Then, possibly in collaboration with overlying allantois-associated extraembryonic visceral endoderm, the XPS establishes a germinal center within the allantois, named here the Allantoic Core Domain (ACD). Microsurgical removal of the ACD beyond headfold (HF) stages resulted in the formation of allantoic regenerates that lacked the ACD and failed to elongate; nevertheless, vasculogenesis and vascular patterning proceeded. In situ and transplantation fate mapping demonstrated that, from HF stages onward, the ACD's progenitor pool contributed to the allantois exclusive of the proximal flanks. By contrast, the posterior intraembryonic primitive streak (IPS) provided the flanks. Grafting the ACD into T(C)/T(C) hosts, whose allantoises are significantly foreshortened, restored allantoic elongation. These results revealed that the ACD is essential for allantoic elongation, but the cues required for vascularization lie outside of it. On the basis of these and previous findings, we conclude that the posterior primitive streak of the mouse conceptus is far more complex than was previously believed. Our results provide new directives for addressing the origin and development of the umbilical cord, and establish a novel paradigm for investigating the fetal/placental relationship.
Salicylic acid ointment peeling of the hands and forearms : effective nonsurgical removal of pigmented lesions and actinic damage

A methyl salicylate-buffered, croton oil-containing 50% salicylic acid ointment peel, following pretreatment with topical tretinoin and localized 20% trichloroacetic acid, is extremely effective for removal of lentigines, pigmented keratoses, and actinically damaged skin from the dorsum of the hands and forearms. The ease of application, uniform results, decreased risk of scarring, and one-time application of this peel, in comparison with other methods used for treatment of these aging-skin changes, warrants consideration by the dermatologic surgeon.
Effect of Long-Term Castration and Long-Term Androgen Treatment on Sexually Dimorphic Estrogen-Inducible Progesterone Receptor mRNA Levels in the Ventromedial Hypothalamus of Whiptail Lizards

In whiptail lizards, as in laboratory rodents, females will respond to exogenous estrogen by increasing progesterone receptor (PR) or PR mRNA in the ventromedial hypothalamus (VMH) while males show an attenuated response to the same treatment. In rodents, neonatal hormone manipulations affect the adult expression of this trait; however, few investigators have examined the effects of hormone treatment in adulthood. Therefore the current study was carried out to determine whether observed sex differences in the estrogen response in adulthood may be modified by steroid hormone manipulation. We castrated male whiptail lizards for 1 week (short term) or 6 weeks (long term). We also gonadectomized female whiptails and implanted them with either a Silastic capsule containing testosterone or an empty capsule. At the end of that time all implants were removed and the animals were injected with either estradiol benzoate (EB) or steroid suspension vehicle and their brains were assayed for PR mRNA expression using in situ hybridization. The results demonstrate that in male whiptail lizards, long-term castration increases sensitivity to estradiol as measured by induction of PR mRNA in the VMH; EB-injected long-term castrated males were not different from EB-injected females. However, long-term androgenization did not attenuate the estrogen response in females. This suggests that attenuation of the estrogen response in males requires activation by testicular secretions, but that females cannot be made to show a male phenotype via testosterone administration.
Revised structure of xestocyclamine A and description of a new analogue

Abstract The structure of xestocyclamine A ( 1 ) from the sponge Xestospongia sp. has been revised to 2 . The structure of a new two carbon homologue, xestocyclamine B ( 3 ), is also presented.
The Impact of Interorganizational Imitation on New Venture International Entry and Performance

We examine the impact of interorganizational imitation on new venture international entry and subsequent performance. Using a sample of 150 U.S.–based publicly held new ventures, we find that new v...
Functional polymers. XLIX. Copolymerization of ω-alkenoates with α-olefins and ethylene

The 2,6-dimethylphenyl ester of 10-undecenoic acid was copolymerized with 1-dodecene, 1-octene, 1-hexene, propylene, and ethylene using coordination initiation systems based on “aluminum-activated” titanium trichloride and dialkylaluminum chlorides. The copolymerizations with higher α-olefins proceeded smoothly and gave copolymers incorporating from 60 to 90% of the 10-undecenoate feed. Copolymerization with propylene gave incorporation of 5 mol % of 2,6-dimethylphenyl 10-undecenoate; with ethylene only 3 mol % of the ω-alkenoate was readily incorporated. All copolymers were characterized by elemental analysis, dilute solution viscosity, and by their IR 1H- and 13C-NMR spectra.
Unmet needs and depressive symptoms among low--income older adults.

Previous studies have found that declining health, decreased social interaction, and inadequate financial resources were significant risk factors for late-life depression, and social support from families and friends and religiosity were significant protective factors. In this study, we examined if low-income older adults' perceived unmet need for home- and community-based services for many aging-associated problems would be independently associated with their depressive symptoms, controlling for these known risk and protective factors. We interviewed a total of 213 community-residing older adults to assess their depressive symptoms, using the Geriatric Depression Scale (GDS), and unmet needs in the areas of personal assistance, instrumental and environmental support, emotional support, and other facilitative/enabling services. We found that the number of unmet needs was significantly positively associated with these older adults' depressive symptoms, although it explained only a small proportion of the v...
A survey of shaped-based registration and segmentation techniques for cardiac images

Heart disease is the leading cause of death in the modern world. Cardiac imaging is routinely applied for assessment and diagnosis of cardiac diseases. Computerized image analysis methods are now widely applied to cardiac segmentation and registration in order to extract the anatomy and contractile function of the heart. The vast number of recent papers on this topic point to the need for an up to date survey in order to summarize and classify the published literature. This paper presents a survey of shape modeling applications to cardiac image analysis from MRI, CT, echocardiography, PET, and SPECT and aims to (1) introduce new methodologies in this field, (2) classify major contributions in image-based cardiac modeling, (3) provide a tutorial to beginners to initiate their own studies, and (4) introduce the major challenges of registration and segmentation and provide practical examples. The techniques surveyed include statistical models, deformable models/level sets, biophysical models, and non-rigid registration using basis functions. About 130 journal articles are categorized based on methodology, output, imaging system, modality, and validations. The advantages and disadvantages of the registration and validation techniques are discussed as appropriate in each section.
Natural and induced immunity to hepatitis B virus among the staff of a pediatric oncology center

All employees of St. Jude Children's Research Hospital who were at risk for occupational exposure to hepatitis B virus were considered appropriate candidates for immunization when the vaccine was licensed in November 1981. Because a high prevalence of hepatitis B immunity was expected among the staff, preimmunization screening was undertaken in the belief that it would be cost effective. Of 315 candidates screened for antibody to the hepatitis B surface antigen (anti-HBs), 79 (25%) had detectable levels and 48 (15%) had titers of greater than or equal to 10 ratio units (RU). The highest rates of anti-HBs positivity were found among housekeepers (40%), nursing assistants (35%), physicians (31%), clinical laboratory workers (29%), and ward clerks (27%); nurses had the lowest rate (16%). An evaluation of potential risk factors implicated age greater than 30 years as having greatest importance. Serum samples were collected from 221 employees 3 months after their third dose of vaccine and tested for anti-HBs; 218 (98.6%) were seropositive. Eighteen employees who had detectable anti-HBs in the range of 2.1 to 9.9 RU before immunization responded well to the vaccine; the titers rose from an average of 4 RU before vaccination to an average of 313 RU 3 months after the third dose. The findings indicate that preimmunization screening of all health care workers identified as candidates for vaccination may not be necessary or economically feasible. If a screening program is undertaken, however, anti-HBs testing of only those persons greater than 30 years of age would increase the program's cost effectiveness.
Mass transfer induced hydraulic actuation in ionic polymer-metal composites

Discussed is the phenomenon of mass transfer-induced hydraulic actuation in ionic polymer-metal composites (IPMCs) strips with chemically plated surface electrodes. A new category of actuators as “mass transfer induced hydraulic actuators (MTIHAs)” is thus defined. Such mass transport of ions and water is across the thickness of the strip and ends up near the permeable metal electrodes. The imposition of an electric field causes the mobile hydrated cations that are conjugated to the polymeric network anions to undergo electrophoretic dynamic migration that can result in local deformation of the material. Such an electrophoretic behavior of the hydrated cations in IPMC causes the water to flow across the strip and partially leak out of the cathode side of the permeable electroded boundary. These leakages are undesirable because they lower the actuation performance. The IPMC is a good example of such MTIHAs. The advantage of MTIHAs is their potential to generate substantially high force densities if the lea...
Electrochemical reactivity at redox-molecule-based nanoelectrode ensembles

Abstract A model describing electrochemical reactivity at nanoelectrode ensembles consisting of redox-molecule-based active sites immobilized on otherwise passivated electrode surfaces is presented. A mathematical treatment in terms of hemispherical diffusion of redox-active solutes to a layer of independent molecule-based nanoelectrode sites is shown to be equivalent to one in terms of a bimolecular diffusion-limited reaction between a layer of immobilized redox molecules and a reservoir of redox-active solutes. This equivalence derives from the fact that in both cases the mass-transfer problem is essentially that of hemispherical diffusion. The model is further developed to consider rate limitation by both the bimolecular redox reaction between the active-site molecule and redox molecules in solution and the heterogeneous redox reaction between the electrode and the active-site molecule. Analytical expressions are derived for the current–voltage relation corresponding to catalyzed electron transfer at an ensemble of redox-molecule-based nanoelectrode sites, and the expressions are used to interpret preliminary data for ultrasensitive electrochemical detection in flow streams via an electrochemical amplification process that is thought to involve redox mediation by individual analyte molecules adsorbed onto monolayer-coated electrodes.
Nickel speciation via voltammetric quantification of nickel metal, oxides and salts

Abstract A practical speciation method for a solid mixture of nickel species applicable to atmospheric monitoring of Ni0, Ni2+ and NiOx is reported. This involves magnetic extraction of Ni0 to separate it from the water-soluble nickel salts and the insoluble oxides, followed by adsorptive stripping voltammetry to quantify the nickel in each fraction. The separation scheme was validated by using calibration standards and by simulating air-filter samples prepared with authentic nickel products. The recoveries of nickel were Ni0 94–105% and total nickel 95–102%.
Chaos synchronization in semiconductor lasers with optoelectronic feedback

Chaos synchronization is experimentally investigated in semiconductor lasers with delayed optoelectronic feedback. Depending on the coupling strength of the driving signal to the receiver, the lasers fall into different regimes of chaos synchronization or modulation. Synchronization happens when the coupling strength to the receiver matches the feedback strength to the transmitter, where the receiver output reproduces the output of the transmitter regardless of the presence of channel distortion or an encoded message. Modulation dominates when the coupling strength is much less than the feedback strength, where the receiver output follows the driving signal. In between, there is no sharp transition between these two regimes but only a mixture of the two phenomena. Driven oscillation is not observed in this optoelectronic feedback system when the coupling strength is increased to a level higher than the feedback strength.
Removing the regulatory N-terminal domain of cardiac troponin I diminishes incompatibility during bacterial expression.

Abstract Troponin I (TnI) is a muscle-specific protein and plays an allosteric function in the Ca2+ regulation of cardiac and skeletal muscle contraction. Expression of cloned cDNA in Escherichia coli is an essential approach to preparing human TnI and mutants for structural and functional studies. The expression level of cardiac TnI in E. coli is very low. To reduce the potential toxicity of cardiac TnI to the host cell, we constructed a bi-cistronic expression vector to co-express cardiac TnI and cardiac/slow troponin C (TnC), a natural binding partner of TnI and a protein that readily expresses in E. coli at high levels. The co-expression moderately increased the expression of cardiac TnI although a high amount of TnC protein was produced from the bi-cistronic mRNA. The use of an E. coli strain containing additional tRNAs for certain low bacterial usage eukaryotic codons improved the expression of cardiac TnI. Modifications of two 5′-regional codons that have predicted low usages in bacterial cells did not reproduce the improvement, indicating that not the 5′ but the overall codon usage restricts the translational efficiency of cardiac TnI mRNA in E. coli. However, deletion of the cardiac TnI-specific N-terminal 28 amino acids significantly improved the protein expression independent of the host cell tRNA modifications. The results suggest that the regulatory N-terminal domain of cardiac TnI is a dominant factor for the incompatibility in bacterial cells, supporting its role in modulating the overall molecular conformation.
Toxic responses of germinating pollen and soybeans to aflatoxins

Aflatoxin producing strains of Aspergillus grow on soybeans thereby contaminating the latter through secretion of the toxin. Investigations dealing with either soybean seed germination or intact seedling growth responses to aflatoxin (B1) are lacking. Similarly, a possible interaction of aflatoxins with phosphate in the germination and elongation of both soybeans and pollen as well as roots of the former and tubes of the latter has not been examined. Imbibition of Glycine max, cv. ‘Essex’ seeds for 18 hours in solutions containing 0.38, 2.90, 5.80 or 11.60 μg/ml (AFB1) yielded% germination inhibitions of 5, 20, 40 and 80, respectively. By 36 hours these were 6, 4, 13 and 19 % for the same toxin concentration series. At 140 hours attached root elongation was inhibited 26, 35 and 50 % for 2.90, 5.80 and 11.60 μg/ml AFB1. No effect was noted at 0.38 μg/ml AFB1. Incubation of excised roots in medium containing 3.0 mM KH2PO4 stimulated their elongation 3.2 fold. Addition of 33.28 μg/ml mixed aflatoxins together with KH2PO4 resulted in only a 1.5 fold stimulation. When KH2PO4 was added to a culture medium lacking AFB1, Lilium longiflorum, cv. ‘Ace’ pollen germination was enhanced 50%. Withholding KH2PO2 but supplying AFB1 did not markedly affect germination. However, supplementing the medium with KH2PO4 while simultaneously adding AFB1 did not inhibit germination at 5 and 10 μg/ml but caused 27.3 and 45.1 % declines at 25 and 30 μg/ml. In the absence of KH2PO4 AFB1 stimulated pollen tube elongation 7.5, 14.3, 16.5 and 13.2 % at 5, 10, 15 and 20 μg/ml but 30 μg/ml inhibited it 11.1%. In contrast, tube elongation was suppressed at all AFB1 concentrations (maximum 36.1% at 30 μg/ml) tested upon KH2PO4 addition. Results derived from germinating pollen in medium supplemented with KH2PO4 or NaH2PO4 indicate that the phosphate anion does not preferentially promote aflatoxin-induced inhibition of tube elongation.
Computing and fitting SSNMR powder patterns with the arithmetic‐geometric mean and edge detection

This paper presents a very ecient technique for approximating the ideal SSNMR powder pattern using the arithmetic-geometric mean and demonstrates finding an initial fitting of the ideal powder pattern to an experimental spectrum via Marr-Hildreth edge detection. In particular, the edge detection approach is used to identify possible values for the principal values of the chemical shielding tensor. These possibilities are then evaluated using a heuristic approach for choosing the best estimates of the principal values based on a measure of edge strength and the sign of the third derivative of the broadened experimental spectrum. We present a detailed mathematical development of the ideal SSNMR powder spectrum and of the arithmetic geometric mean and summarize the fundamental ideas of line broadening and edge detection. The algorithms in the paper are demonstrated in a program supplied in the appendix and are applied to experimental data from [ 13 C1]-leucine.
Wish to die in end-stage ALS.

Background: In retrospective studies, estimates of hastened dying among seriously ill patients range from Objective: To examine, in prospective studies, dying patients in the months before death, in order to understand the wish to die. Methods: Patients with advanced ALS with a high likelihood of death or need for tracheostomy within 6 months were identified. Patients were assessed monthly with an extensive psychosocial interview, including a diagnostic interview for depression. Family caregivers were interviewed on the same schedule and also after patient deaths. Results: Eighty patients with ALS were enrolled, 63% of eligible patients; 53 died over follow-up. Ten (18.9%) of the 53 expressed the wish to die, and 3 (5.7%) hastened dying. Patients expressing the wish to die did not differ in sociodemographic features, ALS severity, or perceived burden of family caregivers. They were more likely to meet criteria for depression, but differences were smaller when suicidality was excluded from the depression interview. Patients who expressed the wish to die reported less optimism, less comfort in religion, and greater hopelessness. Compared with patients unable to act on the wish to die, patients who hastened dying reported reduction in suffering and increased perception of control over the disease in the final weeks of life. Conclusion: These findings suggest caution in concluding that the desire to hasten dying in end-stage disease is simply a feature of depression.
The use of allograft dermis implants and the facelift incision in parotid surgery

A good result from parotid surgery commonly leaves a visible scar in the neck from the modified Blair incision and a soft-tissue defect at the resection site. We have used the facelift incision to better camouflage the scars and have reconstructed the surgical defect using allograft dermis implants. Used in combination, these techniques provide improved esthetic outcomes.
Multiple endocrinopathies in an infant with fatal neurodegenerative disease

We report on a male infant with congenital hypoparathyroidism who developed primary hypothyroidism at 3 months and insulin-dependent diabetes mellitus at 25 months. He had evidence of widespread and progressive neurologic dysfunction characterized by severe developmental delay, blindness, deafness, seizures, atrophy of the cerebellar and frontal lobes, and elevated spinal fluid protein. Also noted were renal hypoplasia, hyporeninemic hypoaldosteronism, chronic anemia, persistent elevation of liver transaminase levels, abnormal intraventricular cardiac conduction, reduction in numbers of helper T-cells, and distinctive facial anomalies. The child died of multiorgan failure at 29 months. A mitochondrial basis for the syndrome was considered but a molecular mechanism has, as yet, not been identified.
The mechanism of apolipoprotein B-100 thiol depletion during oxidative modification of low-density lipoprotein.

Abstract Oxidation of low-density lipoprotein (LDL) is recognized to be a key step in atherogenesis. Previous studies show that LDL contains low-molecular-weight antioxidants such as vitamin E, β-carotene, and ubiquinol, which can retard oxidative modification. In this report, we have evaluated the antioxidant potential of apolipoprotein B-100 (apo-B) thiols during LDL oxidation. Both apo-B thiols and vitamin E were depleted concomitantly during the lag phase of Cu2+-mediated LDL oxidation. The rate of thiol depletion was significantly inhibited by the lipophilic spin trapN-tert-butyl-α-phenylnitrone (PBN) but not by the water-soluble spin trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN). Blocking apo-B thiols with sulfhydryl modifying agents increased the oxidizability of LDL. As with Cu2+, peroxynitrite also caused depletion of apo-B thiols, and again thiol depletion was inhibited by PBN but not by POBN. A PBN/lipid-derived radical adduct was observed by the electron spin resonance technique during oxidation of LDL with peroxynitrite. We conclude that apo-B thiol depletion is mediated by lipid peroxidation, prior to the onset of the propagation phase of LDL oxidation. The implications of apo-B thiols as intrinsic antioxidants of LDL are discussed.