cssi/SciSciGPT-SciSciNet huggingface dataset:
The effects of scaffold thickness on tissue engineered cartilage in photocrosslinked poly(ethylene oxide) hydrogels

Abstract The thickness of human articular cartilage has been reported to vary from less than 0.5 up to 7 mm. Hence, tissue engineered cartilage scaffolds should be able to span the thickness of native cartilage to fill defects of all shapes and sizes. In this study, we demonstrate the potential for using photopolymerization technology to encapsulate chondrocytes in poly(ethylene oxide) hydrogels, which vary in thickness from 2 to 8 mm. Chondrocytes, encapsulated in an 8 mm thick, photocrosslinked hydrogel and cultured in vitro for 6 weeks, remained viable and produced cartilaginous tissue throughout the construct comparable to a 2 mm thick gel as seen both histologically and biochemically. In addition, the total collagen and glycosaminoglycan contents per wet weight of the 8 mm thick cell-polymer construct were 0.13±0.01 and 0.25±0.03%, respectively, and did not vary significantly as a function of spatial position in the construct. The histological evidence and the biochemical content were similar in all constructs of varying thickness. The results suggest that photocrosslinked hydrogels are promising scaffolds for tissue engineering cartilage as cell viability is readily maintained; uniform cell seeding is easy to achieve; and the biochemical content of the extracellular matrix is not compromised as the scaffold thickness is increased from 2 to 8 mm.
Self-interruption on the computer: a typology of discretionary task interleaving

The typical information worker is interrupted every 12 minutes, and half of the time they are interrupting themselves. However, most of the research on interruption in the area of human-computer interaction has focused on understanding and managing interruptions from external sources. Internal interruptions -- user-initiated switches away from a task prior to its completion -- are not well understood. In this paper we describe a qualitative study of self-interruption on the computer. Using a grounded theory approach, we identify seven categories of self-interruptions in computer-related activities. These categories are derived from direct observations of users, and describe the motivation, potential consequences, and benefits associated with each type of self-interruption observed. Our research extends the understanding of the self-interruption phenomenon, and informs the design of systems to support discretionary task interleaving on the computer.
Solution of time domain problems without using the time variable

In this presentation, we propose a numerical method to obtain an unconditionally stable solution for any time domain problems without using the time variable. The classes of problems not only include integral equations, but also deal with finite element time domain and finite difference time domain techniques. This novel method does not utilize the customary marching-on in time solution method often used to solve a hyperbolic partial differential equation. Instead we solve the wave equation by expressing the transient behaviors in terms of associate Laguerre polynomials. By using these orthonomal basis functions for the temporal variation, the time derivatives can not only be handled analytically, but also they can be eliminated completely from the final computations. Since these weighted associate Laguerre polynomials converge to zero as time progresses, the induced electric currents when expanded in a series of weighted Laguerre polynomials also converge to zero. In order to solve the wave equation, we introduce two separate testing procedures, a spatial and temporal testing. By introducing first use the temporal testing procedure, the marching-on in time procedure is replaced by a recursive relation between the different orders of the weighted Laguerre polynomials. The other novelty of this approach is that through the use of the entire domain Laguerre polynomials for the expansion of the temporal variation of the current, the spatial and the temporal variables can be separated. Examples will be presented using all the three classes of techniques.
Iconic representation of the human face with computer graphics

There are many applications for the iconic representation of the human face. The program dicussed here was designed to describe the face by means of measurements made on a skeletal radiograph and, in particular, could be used to indicate changes resulting from oral surgery (2). The computer generated faces are drawn using a program modified by the authors which was produced and kindly given to us by Mr Robert Jacob and Dr William H Huggins of the Johns Hopkins University. Their program was based on that developed by Dr Herman Chernoff (1) of Stanford University. The program was originally designed for the presentation of multivariate statistical data and was modified by Jacob and Huggins for use in iconic communication. As are sult of our modifications, the mouth, nose, and facial outline are presented more realistically, the data input is interactive and quicker, especially when only a few input variables are more directly related to facial components to facilitate accuracy in drawing.
A passivity-based stability criterion for a class of biochemical reaction networks

This paper presents a stability test for a class of interconnected nonlinear systems motivated by biochemical reaction networks. The main result determines global asymptotic stability of the network from the diag- onal stability of a dissipativity matrix which incorporates information about the passivity properties of the subsystems, the interconnection structure of the network, and the signs of the interconnection terms. This stability test encom- passes the secant criterion for cyclic networks presented in [1], and extends it to a general interconnection structure represented by a graph. The new stabil- ity test is illustrated on a mitogen-activated protein kinase (MAPK) cascade model, and on a branched interconnection structure motivated by metabolic networks. The next problem addressed is the robustness of stability in the presence of di®usion terms. A compartmental model is used to represent the localization of the reactions, and conditions are presented under which stability is preserved despite the di®usion terms between the compartments.
Dynamics of glycolipids in the liquid-crystalline state. 2H NMR study.

It has been shown previously that two types of motion are adequate to describe the partially relaxed 2H NMR line shapes (inversion recovery experiment) for the backbone portion of the glycolipid 1,2-di-O-tetradecyl-3-O-(beta-D-glucopyranosyl)-sn-glycerol (beta-DTGL) in the highly ordered gel phase (Auger, M.A., D. Carrier, I.C.P. Smith, and H. C. Jarrell. 1990. J. Am. Chem. Soc. 112:1373–1381). This study extends the latter investigation to the more fluid liquid-crystalline phase, where more complex motions are anticipated. Analyses of the powder line shapes and oriented sample relaxation data for both the glycerol backbone and head group regions of this lipid have been performed. The dynamics of glycerol at the C3 position in the gel state have been described by large angle jumps about the C2-C3 bond with a correlation time in the fast-limit motional regime (omega o tau c much less than 1) and site populations 0.46, 0.34, and 0.20. The present data show that in the liquid-crystalline phase the internal jump rate is maintained, and two additional motions are necessary to describe the dependence of the relaxation rate on the orientation of the director with respect to the magnetic field direction. These are rotation about the molecular long axis with a correlation time in the slow-limit motional regime very near to the T1 minimum (omega o tau c approximately 0.65), and molecular fluctuations about the order director (modeled by a Maier-Saupe restoration potential). This treatment was also extended to the glucose head group where additional segmental motion about the glycosidic bond has been reported previously. While the two motions dominating relaxation at the glycerol C3 segment reproduce the general relaxation features of the glucose head group, the results suggest that additional motion about the glycosidic linkage must be present. This study is a stringent test of the motional model chosen earlier because relaxation data were obtained at two 2H NMR frequencies using two relaxation experiments (T1Z and T1Q) and two types of sample preparation (oriented and dispersed multibilayers). The results strongly uphold the choice of model and indicate the utility of both oriented samples and the T1Q experiment.
Bayes Sequential Designs of Fixed Size Samples from Finite Populations

Abstract The problem of choosing a sample of a fixed size from a finite population is studied in the framework of Bayes designs. The conjectured non-randomized character of Bayes designs is verified. Bayes designs are shown to be without replacement selections, which are generally sequential ones. Sufficient conditions are provided for the optimality of single-phase designs. An example is provided of a case in which the optimal Bayes design is sequential.
U4 snRNA nucleolar localization requires the NHPX/15.5-kD protein binding site but not Sm protein or U6 snRNA association

All small nuclear RNAs (snRNAs) of the [U4/U6.U5] tri-snRNP localize transiently to nucleoli, as visualized by microscopy after injection of fluorescein-labeled transcripts into Xenopus laevis oocyte nuclei. Here, we demonstrate that these RNAs traffic to nucleoli independently of one another, because U4 snRNA deleted in the U6 base-pairing region still localizes to nucleoli. Furthermore, depletion of endogenous U6 snRNA does not affect nucleolar localization of injected U4 or U5. The wild-type U4 transcripts used here are functional: they exhibit normal nucleocytoplasmic traffic, associate with Sm proteins, form the [U4/U6] di-snRNP, and localize to nucleoli and Cajal bodies. The nucleolar localization element (NoLE) of U4 snRNA was mapped by mutagenesis. Neither the 5′-cap nor the 3′-region of U4, which includes the Sm protein binding site, are essential for nucleolar localization. The only region in U4 snRNA required for nucleolar localization is the 5′-proximal stem loop, which contains the binding site for the NHPX/15.5-kD protein. Even mutation of just five nucleotides, essential for binding this protein, impaired U4 nucleolar localization. Intriguingly, the NHPX/15.5-kD protein also binds the nucleolar localization element of box C/D small nucleolar RNAs, suggesting that this protein might mediate nucleolar localization of several small RNAs.
The thermal decomposition of azomethane-d6†

The thermal decomposition of azomethane-d6 has been studied. There is a short chain reaction, and measurements have been made of the rate of production of N2, CD4, and C2D6. A mechanism is suggested which accounts for these results fairly well. A comparison is made with some similar results of Forst for azomethane. Measurements have also been made of the reaction inhibited by NO. It is believed that the N2 production, extrapolated to zero NO pressure, measures the rate of the initial step CD3N2CD3 2 CD3 + N2. This has an activation energy at high pressures of 50.7 kcal per mole and an Arrhenius A·factor of 1015.49 sec−1. This is to be compared to values of 55.5 and 1017.3 found by Forst and Rice for CH3N2CH3 2 CH3 + N2. The pressure fall-off behavior for CD3N2CD3 2 CD3 + N2 has also been investigated and compared to the theoretical curves, which seem to fit satisfactorily except at the lowest pressure, where experimental errors may be large. Unexpectedly, the fall-off curve crosses that for CH3N2CH3 2 CH3 + N2. It is suggested that the extrapolation to zero NO pressure may not be entirely correct in the CH3N2CH3 case where the chain is longer than with CD3N2CD3. It is believed that the decomposition of azomethane-d6 is a better example for unimolecular-rate theory than is that of azomethane.
Adverse effects of angiotensin converting enzyme (ACE) inhibitors. An update

The angiotensin converting enzyme (ACE) inhibitors are a group of effective drugs with a unique mechanism of action. These drugs have proven to be useful for hypertension and congestive heart failure. Early clinical trials of captopril used doses that are now known to be inappropriately high, and dose-related adverse effects were observed frequently. The recognition that lower doses are effective has reduced the incidence of adverse reactions and resulted in improved patient tolerance. When patients are properly selected and correctable risk factors are removed, serious side effects are uncommon. Unfortunately, the early reputation of nephrotoxicity persists, as does the belief that significant blood dyscrasias, endocrine effects and rash are serious risks for the average patient. After wide use of captopril, enalapril and lisinopril, and investigational trials of nearly a dozen newer agents, a sufficiency of clinical observation, experimental evidence and accurate postmarketing recording of events is accumulating to allow insight into the major toxicities with regard to more intelligent patient selection, more rational dosing and proper identification of risk factors. The most common adverse reactions are cough and skin rash. It appears that the agents are generally not cross-reactive with regard to skin rash, although it is not clear whether this effect is drug-specific or class-specific with regard to cough. Statistically but not clinically significant lowering of haemoglobin and hematocrit is common; these effects are inconsequential in most patients. Neutropenia, once thought to be prevalent, now appears to be so only in patients with autoimmune or collagen-vascular disease; the majority of patients outside these groups are at low risk. Hyperkalaemia is a frequent occurrence. This should not be surprising in view of the effect of the ACE inhibitors on plasma aldosterone. When dietary potassium intake is regulated and sources of altered potassium excretion are identified, hyperkalaemia is seldom a serious problem. Identification of sodium and water deficits allows correction before the drugs are started, and the frequency of hypotension and hyperkalaemia caused by the drugs is quite low if these factors are properly managed. An unexpected finding emerging in recent years is the dry cough associated with ACE inhibitor therapy. Its mechanism is not definitely known. Nonsteroidal anti-inflammatory drugs may control this symptom in some patients. The frequent observation of proteinuria in patients taking ACE inhibitors has gained notice and sometimes caused undue alarm. It is difficult to separate disease effects in diabetes and hypertension from true drug effects.(ABSTRACT TRUNCATED AT 400 WORDS)
In vivo experiments on the mechanism of action of L-arabinose C gene activator and lactose repressor.

Abstract Simultaneous exposure of the cell interior of a rifampin-permeable mutant Escherichia coli to inducer and rifampin demonstrated that 8% ± 3% of the ara operon DNA copies and 1% ± 3% of the lac DNA copies contain an RNA polymerase molecule insensitive to rifampin inhibition. Although previous genetic studies have shown that the operons are controlled via different mechanisms, the data presented here show that both operons are controlled in such a way that an uninduced operon copy has a low probability of possessing an RNA polymerase molecule that has initiated transcription. These in vivo measurements were made possible by the development of techniques to determine accurately the times required for rifampin and inducers to diffuse into cells and attain effective concentrations. 100 μg rifampin/ml requires 4·4 seconds to enter and block further initiations by RNA polymerase, whereas fully inducing concentrations of l -arabinose and IPTG are effective in less than one second. The initial rifampin entry rate into cells is proportional to its extracellular concentration. This relationship allowed calculation of the enzyme induction that would have been observed if the rifampin entry time were zero.
Dual protective role for Glutathione S-transferase class pi against VCD-induced ovotoxicity in the rat ovary

The occupational chemical 4-vinylcyclohexene diepoxide (VCD) selectively destroys ovarian small pre-antral follicles in rats and mice via apoptosis. Detoxification of VCD can occur through glutathione conjugation, catalyzed by glutathione S-transferase (GST) enzymes. Further, GST class pi (GSTp) can negatively regulate JNK activity through protein:protein interactions in extra-ovarian tissues. Dissociation of this protein complex in the face of chemical exposure releases the inhibition of pro-apoptotic JNK. Increased JNK activity during VCD-induced ovotoxicity has been shown in isolated ovarian small pre-antral follicles following in vivo dosing of rats (80 mg/kg/day; 15 days, i.p.). The present study investigated the pattern of ovarian GSTp expression during VCD exposure. Additionally, the effect of VCD on an ovarian GSTp:JNK protein complex was investigated. PND4 F344 rat ovaries were incubated in control medium {+-} VCD (30 {mu}M) for 2-8 days. VCD increased ovarian GSTp mRNA (P < 0.05) relative to control on d4-d8; whereas GSTp protein was increased (P < 0.05) on d6-d8. A GSTp:JNK protein complex was detected by immunoprecipitation and Western blotting in ovarian tissues. Relative to control, the amount of GSTp-bound JNK was increased (P = 0.09), while unbound JNK was decreased (P < 0.05) on d6 of VCD exposure. The VCD-induced decrease inmore » unbound JNK was preceded by a decrease in phosphorylated c-Jun which occurred on d4. These findings are in support of a possible dual protective role for GSTp in the rat ovary, consisting of metabolism of VCD and inhibition of JNK-initiated apoptosis.« less
Successional trajectory of loblolly pine (Pinus taeda) plantations established using intensive management in Southern Mississippi, USA

Abstract Although secondary succession in commercial pine plantations offers opportunities to manage for biodiversity, questions remain regarding effects of stand establishment intensity on biodiversity. Therefore, we examined 9 years of post-harvest plant succession in loblolly pine plantations established under a range of intensive management regimes in Mississippi, USA, including combinations of mechanical site preparation, chemical site preparation, and herbaceous weed control. We evaluated plant community structure using coverage of eight growth forms, and community composition using species-level coverage. Stands established without chemical site preparation retained more post-harvest woody and vine species and had less variable species turnover than chemically prepared stands. Chemically prepared stands provided opportunity for greater expression of early succession herbaceous and subshrub communities. Broadcast herbaceous weed control reduced expression of the early succession community relative to banded applications, but a single broadcast application did not prevent strong re-emergence of that community the following year. Conversely, multiple broadcast applications of herbaceous weed control reduced expression of early succession species beyond the year of final treatment, possibly through inhibiting establishment until favorable conditions were past, rather than by directly favoring woody dominance. Plant community structure converged as crown closure approached, and structural differences were largely insignificant by year 5. However, small differences in composition that may affect biodiversity were retained and may last until midrotation harvest and subsequent treatment. Greater diversity of plant communities in stands with chemical site preparation may benefit biodiversity in establishing plantations if not inhibited by broadcast herbaceous weed control. Resources committed to broadcast weed control may be more usefully diverted to midrotation management that improves biodiversity after thinning. These results can be used to target management of early succession species at stand and landscape scales. Given the known effects of this limited array of treatments on biodiversity, additional establishment regimes should be monitored to provide information critical to meeting stand- and landscape-level biodiversity goals.
Personalizing the user experience on ibm.com

In this paper, we describe the results of an effort to first understand the value of personalizing a Web site, as perceived by the visitors to the site as well as by the stakeholder organization that owns it, and then to develop a strategy for introducing personalization to the ibm.com Web site. We started our investigation by conducting literature reviews, holding brainstorming sessions with colleagues around the world, and performing heuristic usability evaluations of several relevant Web sites. We adopted a User-Centered Design approach and conducted a number of usability studies applied to the subset of the ibm.com Web site that business customers use for all aspects of purchase, service, and support of computer equipment. These studies employed a number of low- and medium- fidelity prototypes that we developed for this purpose. Our proposal for personalizing ibm.com consists of a set of 12 personalization features, selected for the value they offer to customers and to the business.
Social process modeling: A comparison of a live and computerized simulation

The extent to which an entirely computerized simulation could recapture the essential decision-making processes involved in a complex, but controlled laboratory exercise using human subjects is examined. A series of analytic simulations of an exercise called PLANS were run on a digital computer. Beginning with simulations based upon entirely random decision processes, greater and greater degrees of “decision making” sophistication were gradually incorporated into the computerized versions of PLANS. Past efforts to simulate human psychological process on a computer—for example, chess playing and music writing programs—have been directed generally at improving the effectiveness of computer programs. In the present study, involving the simulation of social rather than purely psychological processes, the situation appears reversed: computer programs behaved too rationally and efficiently.
Thermal capture of electrons and holes at zinc centers in silicon

Abstract The thermal capture rates of electrons and holes at zinc centers in silicon are obtained in reversed biased N + P and P + N diodes from junction capacitance transients due to capture of photogenerated and injected carriers. The electric field dependence of the thermal capture rates of holes at singly ionized zinc centers is E −1·1 , while that at doubly ionized zinc centers is exp(− E / E 0 ). The temperature dependence of the thermal capture rate of holes at doubly ionized zinc centers is small. The thermal capture rate of electrons at neutral zinc centers is 2·0×10 −9 cm 3 / sec with very little field dependences, while that at singly ionized zinc centers is 5·0×10 −11 cm 3 / sec with very little field and temperature dependence below 170°K. Auger-impact emission rate of electrons trapped at doubly ionized zinc centers by electrons is 3·5×10 −10 cm 3 / sec with very little field and temperature dependence below 170°K.
The Interaction between Accrual Management and Hedging: Evidence from Oil and Gas Firms

This research investigates whether discretionary accrual decisions and use of derivative instruments areindependent of each other. We examine firms primarily engaged in oil exploration and drilling since we can identify two kinds of risks to which these firms are exposed that can cause earnings volatility. These are oil price risk and exploration risk. While firms can hedge oil price risk with derivative instruments, markets do not exist in which firms can hedge the operational risk of unsuccessful drilling. Discretionary accrual choices can be used to reduce variability in earnings induced by the exploration risks and both discretionary accruals and hedging can reduce earnings variability associated with oil price fluctuations. We find that firms in our sample do not hedge all oil price risk they face, but instead appear to want to achieve some benchmark level of earnings volatility. In our primary analysis, we separate the decision to hedge oil price risk from the extent of hedging, and simultaneously consider the extent of hedging and the extent of smoothing with discretionary accruals. The results indicate that firms are more likely to hedge the higher the level of exploration risk they face. Moreover, after controlling for other determinants of hedging and discretionary accrual smoothing, we find that the extent of hedging and the extent of discretionary accrual smoothing are substitutes.
A practical method for singular integral equations of the second kind

Abstract A convenient and efficient numerical method is presented for the treatment of Cauchy type singular integral equations of the second kind. The solution is achieved by splitting the Cauchy singular term into two parts, allowing one of the parts to be determined in a closed-form while the other part is evaluated by standard Gauss–Jacobi mechanical quadrature. Since the Cauchy singularity is removed after this manipulation, the quadrature abscissas and weights may be readily available and the placement of the collocation points is flexible in the present method. The method is exact when the unknown function can be expressed as the product of a fundamental function and a polynomial of degree less than the number of the integration points. The proposed algorithm can also be extended to the case where the singularities are complex and is found equally effective. The proposed algorithm is easy to implement and provides a shortcut for programming the numerical solution to the singular integral equation of the second kind.
Veverka receives 2011 Whipple Award: Response

Joseph Veverka received the 2011 Whipple Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award recognizes an individual who has made an outstanding contribution in the field of planetary science.
Ionic and pH transitions triggering chloroplast post-illumination luminescence

Abstract The postillumination “chemiluminescence” of isolated spinach chloroplasts, previously shown to be caused by an acid-base transition, is found to be caused also by a transition from a low to a high ionic strength environment. The salt induction of luminescence is in competition with the acid-base luminescence; whichever comes first prevents light emission upon going through the second process. It was discovered that suddenly lowering the pH to 3.2 or below also causes light emission. The acid procedure induces up to eight times as much light emission as the others, and does not seem to compete with them in that raising the pH or the salt concentration causes a further amount of luminescence even after the acid-induced burst. All three procedures share a sensitivity to phosphorylation inhibitors and to DCMU, and all require preillumination of the chloroplasts. Chloroplasts subject to a low to high salt transition do not go into a high energy state, as judged by either ATP formation or ATPase activation. Evidence is presented suggesting that even in the case of acid-base transition the high energy state is not the trigger for light emission.
The choice of functional forms for hedonic price equations: Comment

Abstract Rosen [13], Freeman [4], Halvorsen and Pollakowski [6], and others have stressed that economic theory does not suggest an appropriate functional form for hedonic price functions. 1 It consequently is reasonable to try several functional forms and utilize the multiple regression equation with the best performance. In this spirit, Halvorsen and Pollakowski [6] recommend using the Box-Cox flexible functional form for hedonic analysis and measuring best performance with a goodness of fit test. The Box-Cox methodology has also been adapted in hedonic studies by Goodman [5], Linneman [10], Blomquist and Worley [1], and Eberts and Gronberg [3]. 2 The Box-Cox is particularly suited for testing functional forms because many familiar forms such as semilog, log linear, and translog are subsets of the flexible Box-Cox permitting nested hypothesis testing. In this note, we illustrate that the formal hypothesis testing advantage of the Box-Cox functional form is purchased at the expense of other important goals. The goal of most hedonic studies is to estimate the prices of the characteristics, to measure the response to changes in the prices, and/or to predict future expenditures. Using a best fit criterion to choose functional forms does not necessarily lead to more accurate estimates of characteristic prices. In fact, the large number of coefficients estimated with the Box-Cox functional form reduces the accuracy of any single coefficient which could lead to poorer estimates of specific prices. Second, because any negative number raised to a noninteger real power is imaginary, the traditional Box-Cox functional form is not suited to any data set containing negative numbers. Third, the Box-Cox functional form may be inappropriate for prediction. Since the mean predicted value of the untransformed dependent variable need not equal the mean of the sample upon which it is estimated, the predicted untransformed variable (housing value) will be biased. The predicted untransformed dependent variable may also be imaginary. Fourth, the nonlinear transformation results in complex estimates of slopes and elasticities which are often too cumbersome to use properly. We discuss each of these drawbacks and quantify them when possible in the remainder of this note.
Effects of spirituality in breast cancer survivors.

Purpose/objectives To examine the effects of spirituality (meaning in life and prayer) on a sense of well-being among women who have had breast cancer. Design Descriptive, correlational, cross-sectional. Setting Rural and urban communities in central Texas. Sample Convenience sample of 84 women, 34-80 years of age diagnosed less than one year previously (36%), within the previous one to five years (38%), and more than five years previously (26%). Methods The study approach consisted of completing a questionnaire assessing personal and cancer characteristics, aspects of spirituality (meaning in life and prayer), and physical and psychological responses to breast cancer. Main research variables Meaning in life, prayer, and physical and psychological responses to breast cancer. Findings Meaning in life was positively related to psychological responses and negatively related to physical responses. Prayer was positively related to psychological well-being. Women with higher prayer scale scores reported lower education levels, less income to meet their needs, and closer relationships with God. Meaning in life mediated the impact of breast cancer on physical and psychological well-being. Conclusions Strong relationships exist among spirituality and personal and cancer characteristics. Meaning in life mediated the effects of breast cancer on well-being in breast cancer survivors. Implications for nursing The findings support healthcare providers encouraging women diagnosed with breast cancer to explore their spirituality as an effective resource for dealing with the physical and psychological responses to cancer.
Social Support and Psychological Adjustment Among Latinas With Arthritis: A Test of a Theoretical Model

Background: Among people coping with chronic illness, tangible social support sometimes has unintended negative consequences on the recipient’s psychological health. Identity processes may help explain these effects. Individuals derive selfworth and a sense of competence by enacting social roles that are central to the self-concept.Purpose: This study tested a model drawing from some of these theoretical propositions. The central hypothesis was that tangible support in fulfilling a highly valued role undermines self-esteem and a sense of self-efficacy, which, inturn, affect psychological adjustment.Methods: Structured interviews were conductedwith 98 Latina women with arthritis who rated the homemaker identity as being of central importance to the self-concept.Results: A path analysis indicatedthat, contrary to predictions, tangible housework support was related to less psychological distress. Emotional support predicted greater psychological well-being. These relationships were not mediated by self-esteem or self-efficacy. Qualitative data revealed that half of the sample expressed either ambivalent or negative feelings about receiving housework support.Conclusions: Results may reflect social and cultural norms concerning the types of support that are helpful and appropriate from specific support providers. Future research should consider the cultural meaning and normative context of the support transaction. This study contributes to scarce literatures on the mechanisms that mediate the relationship between social support and adjustment, as well as illness and psychosocial adaptation among Latina women with chronic illness.
Chronic 'blindness' following lesions of nonvisual cortex in the monkey.

Chronic ‘blindness’ was produced in monkeys by a lesion that combined right optic tract section, forebrain commissurotomy, and a large cortical ablation in the left hemisphere that spared most of the modality specific visual cortex. The finding suggests that, contrary to implications from earlier studies, central visual processes can influence behavior only with the participation of nonvisual cortex.
Variability in marine resources affects arctic fox population dynamics

Summary 1. Terrestrial predators in coastal areas are often subsidized by marine foods. In order to determine the potential impact on terrestrial prey, the numerical response of predators to each food source must be determined. 2. In winter, arctic foxes ( Alopex lagopus ) may forage on the frozen Arctic ocean and scavenge carcasses of seals killed by polar bears ( Ursus maritimus ), but the importance of this food source and its effect on the population cycles of arctic foxes and lemmings (their primary prey) are unclear. 3. I estimated the marine component of the late winter diet of arctic foxes near Churchill, Manitoba, using stable-carbon isotope analysis, and compared these estimates to abundance of arctic foxes and collared lemmings ( Dicrostonyx richardsoni ). 4. From 1994 to 1997, fox density varied with lemming abundance, but following a decline, fox abundance began increasing before lemmings. During this increase marine foods were consumed more than in other years, with over two-thirds of food intake from marine sources. 5. Arctic and red fox ( Vulpes vulpes ) harvests in the 1980s to 1990s were correlated with published estimates of polar bear body mass, which varies with seal productivity. However, this relationship disappeared during high lemming years. 6. Thus, variation in marine productivity affects arctic fox abundance, especially when their primary prey are scarce, and this numerical response of arctic foxes to marine resources and lemmings suggests that increased predation by arctic foxes subsidized by seal carrion may delay the recovery of low lemming populations.
Probability and delay discounting of erotic stimuli

Adult undergraduate men (n = 38) and women (n = 33) were categorized as erotica “users” (n = 34) and “non-users” (n = 37) based on their responses to screening questions and completed computerized delay and probability discounting tasks concerning hypothetical money and erotica. Erotica users discounted the value of erotica similarly to money on three of the four erotica tasks; erotica non-users discounted the value of money consistent with erotica users, but not the value of erotica. Erotica users were disproportionately male, scored higher on several psychometric measures of sexuality-related constructs, and exhibited more impulsive choice patterns on the delay discounting for money task than erotica non-users did. These findings suggest that discounting processes generalize to erotic outcomes for some individuals.
The influence of race/ethnicity on disadvantaged mothers' child care arrangements

This study uses data from the Fragile Families and Child Wellbeing Study [Reichman, N., Teitler, J., Garfinkel, I., & McLanahan, S. (2001). The fragile families and child wellbeing study: Sample and design. Children and Youth Services Review, 23, 303–326] to describe primary child care arrangements of employed, predominantly low-income mothers of 1-year olds, and to quantify their child care calculus in the post-welfare reform era. The sorting of children across arrangement types differs by mother's race/ethnicity: Hispanic children are most likely to be cared for maternal kin, Black children in organized centers, and White children by their fathers. Multinomial regression reveals that the association between race/ethnicity and arrangement type is largely – but not entirely – accounted for by mothers’ socioeconomic, household, job, and cultural characteristics; interaction tests show that the associations between arrangement type and both poverty status and marital status are contingent on race/ethnicity. These findings indicate that disadvantage does not translate into child care arrangements similarly across racial/ethnic groups and child care policy must take into account structural and cultural differences associated with parents’ race/ethnicity.
A Proposed Second Harmonic Acceleration System for the Intense Pulsed Neutron Source Rapid Cycling Synchrotron

The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2 to 2.5 x 10/sup 12/ protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at approx.3 x 10/sup 12/ ppp, depending somewhat on the available aperture. With the present good performance in mind, accelerator improvements are being directed at: (1) increasing beam intensities for neutron science; (2) lowering acceleration losses to minimize activation; and (3) gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. On the basis of preliminary measurements, we are now proposing a third cavity for the RF systems which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses.
Health-related quality of life after percutaneous coronary intervention versus coronary bypass surgery in high-risk patients with medically refractory ischemia.

Abstract Objectives We compared six-month health-related quality of life (HRQL) for high-risk patients with medically refractory ischemia randomized to percutaneous coronary intervention (PCI) versus coronary artery bypass graft (CABG) surgery. Background Mortality rates after PCI and CABG surgery are similar. Therefore, differences in HRQL outcomes may help in the selection of a revascularization procedure. Methods Patients were enrolled in a Veterans Affairs multicenter randomized trial comparing PCI versus CABG for patients with medically refractory ischemia and one or more risk factors for adverse outcome; 389 of 423 patients (92%) alive six months after randomization completed an Short Form-36 (SF-36) health status survey. Primary outcomes were the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-36. Multivariable analyses were used to evaluate whether PCI or CABG surgery was associated with better PCS or MCS scores after adjusting for over 20 baseline variables. Results There were no significant differences in either PCS scores (38.7 vs. 37.3 for PCI and CABG, respectively; p = 0.23) or MCS scores (45.5 vs. 46.1, p = 0.58) between the treatment arms. In multivariable models, there remained no difference in HRQL for post-PCI versus post-CABG patients (for PCS, absolute difference = 0.56 ± standard error of 1.14, p = 0.63; for MCS, absolute difference = −1.23 ± 1.12, p = 0.27). We had 97% power to detect a four-point difference in scores, where four to seven points is a clinically important difference. Conclusions High-risk patients with medically refractory ischemia randomized to PCI versus CABG surgery have equivalent six-month HRQL. Therefore, HRQL concerns should not drive decision-making regarding selection of a revascularization procedure for these patients.
Structures of minute virus of mice replication initiator protein N-terminal domain: Insights into DNA nicking and origin binding.

Members of the Parvoviridae family all encode a non-structural protein 1 (NS1) that directs replication of single-stranded viral DNA, packages viral DNA into capsid, and serves as a potent transcriptional activator. Here we report the X-ray structure of the minute virus of mice (MVM) NS1 N-terminal domain at 1.45 A resolution, showing that sites for dsDNA binding, ssDNA binding and cleavage, nuclear localization, and other functions are integrated on a canonical fold of the histidine-hydrophobic-histidine superfamily of nucleases, including elements specific for this Protoparvovirus but distinct from its Bocaparvovirus or Dependoparvovirus orthologs. High resolution structural analysis reveals a nickase active site with an architecture that allows highly versatile metal ligand binding. The structures support a unified mechanism of replication origin recognition for homotelomeric and heterotelomeric parvoviruses, mediated by a basic-residue-rich hairpin and an adjacent helix in the initiator proteins and by tandem tetranucleotide motifs in the replication origins.
Automatic calibration and neural networks for robot guidance

An autonomous robot must be able to sense its environment and react appropriately in a variable environment. The University of Cincinnati Robot team is actively involved in building a small, unmanned, autonomously guided vehicle for the International Ground Robotics Contest organized by Association for Unmanned Vehicle Systems International (AUVSI) each year. The unmanned vehicle is supposed to follow an obstacle course bounded by two white/yellow lines, which are four inches thick and 10 feet apart. The navigation system for one of the University of Cincinnati’s designs, Bearcat, uses 2 CCD cameras and an image-tracking device for the front end processing of the image captured by the cameras. The three dimensional world co-ordinates were reduced to two dimensional image coordinates as a result of the transformations taking place from the ground plane to the image plane. A novel automatic calibration system was designed to transform the image co-ordinates back to world co-ordinates for navigation purposes. The purpose of this paper is to simplify this tedious calibration using an artificial neural network. Image processing is used to automatically detect calibration points. Then a back projection neural algorithm is used to learn the relationships between the image coordinates and three-dimensional coordinates. This transformation is the main focus of this study. Using these algorithms, the robot built with this design is able to track and follow the lines successfully.
High temperature, spectral-directional emittance of high purity nickel oxidized in air

Spectral-directional emittance measurements for 99.99% nickel, thermally oxidized in air, were performed at temperatures of 673, 773, and 873 K using an apparatus comprised of a Fourier transform infrared (FTIR) spectrometer, a blackbody radiating cavity (hohlraum), and a sample holder which allows directional measurements. The data cover the spectral range between 2 and 20 μm, and the directional range from a surface normal to 72° polar angle. The Ni sample had a nominal surface roughness of 4.1 μm and was heated for 1 h at the measurement temperatures prior to emission measurements. X-ray diffraction and EDS analyses were performed in order to characterize the sample surface. It was found that the normal emittance of oxidized nickel increases with temperature for the temperature range considered. Directional emittance shows slightly departure from pure metal behavior.
SINES of a New Leukemia Treatment

Chronic lymphocytic leukemia (CLL) is the most common type of adult leukemia that is currently incurable. CLL manifests because B lymphocytes fail to die as a result of aberrant activation of survival signals. Dysfunctional tumor suppressor proteins (TSPs) are either silenced or sequestered in the
Characteristics of yeast invertase immobilized on porous cellulose beads.

Invertase from Candida utilis was immobilized on porous cellulose beads by an ionic-quanidino bond. The immobilized invertase showed optimum activity between pH 4.0 and 5.4, while the free enzyme had a sharp optimum at pH 4.1. Both temperature profiles were fairly similar up to 55°C. However, above this temperature the immobilized enzyme was more stable than the free enzyme. From the temperature data, the activation energies were found to be 7,322 and 4,052 cal/g mol for the free and the immobilized enzyme, respectively. Candida invertase shows characteristics of substrate inhibition. Both the Km and Ki for the free and the immobilized enzymes were determined. The apparent Ki for the immobilized invertase was much higher than the Ki of the free enzyme, suggesting a diffusion effect. Immobilized invertase molecules deep in the pores only see sucrose concentrations much less than the bulk concentrations. Immobilization, thus, offers certain processing advantages in this regard.
Effect of Prenatal Alcohol Exposure on Bony Craniofacial Development: A Mouse MicroCT Study

Craniofacial bone dysmorphology is an important but under-explored potential diagnostic feature of fetal alcohol spectrum disorders. This study used longitudinal MicroCT 3D imaging to examine the effect of prenatal alcohol exposure on craniofacial bone growth in a mouse model. C57BL/6J dams were divided into 3 groups: alcohol 4.2% v/v in PMI® liquid diet (ALC), 2 weeks prior to and during pregnancy from embryonic (E) days 7-E16; pair-fed controls (PF), isocalorically matched to the ALC group; chow controls (CHOW), given ad libitum chow and water. The MicroCT scans were performed on pups on postnatal days 7 (P7) and P21. The volumes of the neurocranium (volume encased by the frontal, parietal, and occipital bones) and the viscerocranium (volume encased by the mandible and nasal bone), along with total skull bone volume, head size, and head circumference were evaluated using general linear models and discriminant analyses. The pups in the alcohol-treated group, when compared to the chow-fed controls (ALC vs CHOW) and the isocaloric-fed controls (ALC vs PF), showed differences in head size and circumference at P7 and P21, the total skull volume and parietal bone volume at P7, and volume of all the tested bones except nasal at P21. There was a growth trend of ALC CHOW), and the total skull, parietal bone, and occipital bone at P21 (ALC < CHOW, ALC < PF). While covarying for the P7 measures, the treatment affected only the 3 neurocranial bones at P21 (ALC < CHOW, ALC < PF). Discriminant analysis sensitively selected between ALC and CHOW (AUC = 0.967), between ALC and PF (AUC = 0.995), and between PF and CHOW (AUC = 0.805). These results supported our hypothesis that craniofacial bones might be a reliable and sensitive indicator for the diagnosis of prenatal alcohol exposure. Significantly, we found that the neurocranium (upper skull) was more sensitive to alcohol than the viscerocranium (face).
Unintended population consequences of policies.

Unintended population consequences of policies stem from three sources: (1) A policy overshoots its original goal; (2) different policies conflict, so that the implementation of one policy inhibits implementation of another policy; (3) negative consequences of a policy are unforeseen, or are anticipated but judged unlikely to be severe or considered less important than the positive aims of the policy. Examples from Singapore, South Africa, Italy, the U.S., and the former Soviet Union are discussed.