bluuebunny/crossref_metadata_2025_split huggingface dataset:
A TIME-VARYING CALL CENTER DESIGN VIA LAGRANGIAN MECHANICS
Authors: Hampshire Robert C. , Jennings Otis B. , Massey William A. 
Published: February 2009

We consider a multiserver delay queue with finite additional waiting spaces and time-varying arrival rates, where the customers waiting in the buffer may abandon. These are features that arise naturally from the study of service systems such as call centers. Moreover, we assume rewards for successful service completions and cost rates for service resources. Finally, we consider service-level agreements that constrain both the fractions of callers who abandon and the ones who are blocked.Applying the theory of Lagrangian mechanics to the fluid limit of a related Markovian service network model, we obtain near-profit-optimal staffing and provisioning schedules. The nature of this solution consists of three modes of operation. A key step in deriving this solution is combining the modified offered load approximation for loss systems with our fluid model. We use them to estimate effectively both our service-level agreement metrics and the profit for the original queuing model. Second-order profit improvements are achieved through a modified offered load version of the conventional square root safety rule.
Contour statistics in natural images: Grouping across occlusions
Authors: GEISLER WILSON S. , PERRY JEFFREY S. 
Published: February 2009

AbstractCorrectly interpreting a natural image requires dealing properly with the effects of occlusion, and hence, contour grouping across occlusions is a major component of many natural visual tasks. To better understand the mechanisms of contour grouping across occlusions, we (a) measured the pair-wise statistics of edge elements from contours in natural images, as a function of edge element geometry and contrast polarity, (b) derived the ideal Bayesian observer for a contour occlusion task where the stimuli were extracted directly from natural images, and then (c) measured human performance in the same contour occlusion task. In addition to discovering new statistical properties of natural contours, we found that naïve human observers closely parallel ideal performance in our contour occlusion task. In fact, there was no region of the four-dimensional stimulus space (three geometry dimensions and one contrast dimension) where humans did not closely parallel the performance of the ideal observer (i.e., efficiency was approximately constant over the entire space). These results reject many other contour grouping hypotheses and strongly suggest that the neural mechanisms of contour grouping are tightly related to the statistical properties of contours in natural images.
How many pixels make an image?
Authors: TORRALBA ANTONIO 
Published: February 2009

AbstractThe human visual system is remarkably tolerant to degradation in image resolution: human performance in scene categorization remains high no matter whether low-resolution images or multimegapixel images are used. This observation raises the question of how many pixels are required to form a meaningful representation of an image and identify the objects it contains. In this article, we show that very small thumbnail images at the spatial resolution of 32 × 32 color pixels provide enough information to identify the semantic category of real-world scenes. Most strikingly, this low resolution permits observers to report, with 80% accuracy, four to five of the objects that the scene contains, despite the fact that some of these objects are unrecognizable in isolation. The robustness of the information available at very low resolution for describing semantic content of natural images could be an important asset to explain the speed and efficiently at which the human brain comprehends the gist of visual scenes.
Mass occurrence of hokkaidoconchid gastropods in the Upper Jurassic methane seep carbonate from Alexander Island, Antarctica
Authors: Kaim Andrzej , Kelly Simon R.A. 
Published: February 2009

AbstractThe Tithonian (Upper Jurassic) methane seep carbonate of the Gateway Pass Limestone Bed (Alexander Island, Antarctica) yields enormous numbers of the minute gastropod mollusc, Hokkaidoconcha hignalli sp. nov. together with an unidentified limpet gastropod and occasional protobranch and lucinid bivalves. This assemblage constitutes one of the most abundant (by means of the specimen number) records of Jurassic chemosynthesis-based communities. The gastropod family Hokkaidoconchidae is extremely common in Cretaceous hydrocarbon seep carbonates from Japan and is known also from Upper Jurassic/Cretaceous hydrocarbon seep carbonates in California. It is an extinct family closely related to modern seep and vent dwelling Provannidae. This is the first confirmed record of this family in the Southern Hemisphere, indicating its surprisingly early and widespread distribution reaching high latitudes.
Legal Indeterminacy
Authors: Leiter Brian 
Published: February 2009

To say that the law is indeterminate is to say that the class of legal reasons (hereafter “the Class”) is indeterminate. The Class, in turn, consists of four components:1. Legitimatesourcesof law (e.g., statutes, constitutions, court decisions, social policy, morality);2. Legitimateinterpretiveoperations that can be performed on thesourcesin order to generate rules of law (e.g., proper methods of interpreting statutes or prior cases or of reasoning about moral concepts as these figure in the sources);3. Legitimateinterpretiveoperations that can be performed on thefacts of recordin order to generate facts of legal significance (e.g., proper ways of grouping and categorizing fact situations for purposes of legal analysis); and4. Legitimaterationaloperations that can be performed on facts and rules of law to finally yield particular decisions (e.g., deductive reasoning).
Commodification and Phenomenology: Evading Consent in Theory Regarding Rape
Authors: Bogart John H. 
Published: February 2009

In a recent essay, Donald Dripps advanced what he calls a “commodification theory” of rape, offered as an alternative to understanding rape in terms of lack of consent. Under the “commodification theory,” rape is understood as the expropriation of sexual services, i.e., obtaining sex through “illegitimate” means. One aim of Dripps's effort was to show the inadequacy of consent approaches to understanding rape. Robin West, while accepting Dripps's critique of consent theories, criticizes Dripps's commodification approach. In its place, West suggests a more phenomenological approach.The author argues that (1) neither Dripps nor West offers convincing critiques of consent-based theories; (2) the alternatives they offer presuppose the vitality of a consent-based approach to understanding rape; and (3) that both Dripps and West consistently conflate more general moral and political issues with that of the nature of rape.
Comments on Elster
Authors: Seidman Louis Michael 
Published: February 2009

Jon Elster's subtle and richly illustrated argument raises more avenues of inquiry and application than one could possibly explore in a short comment. I will therefore confine myself to addressing three interrelated questions:First, can the distinctions among interest, passion, and reason on which his analysis depends really be maintained?Second, what implications does his work hold for some republican and liberal theories that insist on a public sphere purged of interest and passion or that defend a private sphere providing the space necessary to indulge interest and passion?Finally, what does his analysis tell us about the possibility of a meta-theory that would mediate among interest, passion, and reason?With regard to the first question, Elster's own argument suggests that the boundaries among interest, passion, and reason are at least permeable. Each motive masquerades as the other or becomes transmuted into the other. Moreover, once one takes the consistency and imperfection constraints into account, the external manifestations of the different motives will often be identical. A positivist, who believes that all that matters are external manifestations that can be measured or observed, might therefore hold that the distinctions Elster analyzes are ones that are hardly worth worrying about.
“A Nod's as Good as a Wink”: Consent, Convention, and Reasonable Belief
Authors: Archard David 
Published: February 2009

Consider the following examples of behavior by Smith:1. Smith, seated at her restaurant table, gives an order to the waiter;2. Smith gets into a cab and names a destination;3. Smith agrees to Jones's suggestion that they go back to Jones's apartment for a few drinks;4. Smith casts her vote in some election.In each of these instances what can Smith be understood as consenting to? Is she consenting to (1) pay the bill for whatever meal she orders; (2) pay the fare for the journey to her named destination; (3) sexual intimacy with Jones; and (4) accept the authority of whatever individual or political part is elected? The fact that Smith does not actually express her consent to each of these states of affairs or outcomes need not mean that she is not giving her consent to them. The idea that individuals can give their consent in ways other than by means of a formal verbal expression of agreement is a familiar, if controversial, one.
Development of a performance-rating scale for a nutrition knowledge test developed for adolescents
Authors: Whati Lindiwe , Senekal Marjanne , Steyn Nelia P , Lombard Carl , Nel Johanna 
Published: February 2009

AbstractObjectiveThe objectives of the present study were to (i) develop and validate a norm-referenced performance-rating scale to interpret a nutrition knowledge test developed for urban adolescents and (ii) develop a prototype for other researchers to follow when developing nutrition knowledge tests.DesignFor norm development the nutrition knowledge test (questionnaire) was administered to a sample representative of the questionnaire target group, referred to as the norm group. These included 512 adolescents in grades 8 (n158), 10 (n149) and 12 (n205) at three randomly selected schools in Soweto and Johannesburg. The performance scores (in percentages) obtained by the norm group were transformed toZ-scores which were categorised into stanines using establishedZ-score cut-off points. For validation purposes the questionnaire was completed by 148 volunteers: sixty university dietetics students, nineteen non-nutrition university students and sixty-nine primary-school teachers.ResultsAs required of an ideal norm group, theZ-scores formed a normal distribution (a bell-shaped curve). To facilitate interpretation of the results, theZ-score cut-off points for these categories were transformed back to performance scores (percentages) so that the performance of a testee could be interpreted directly from his/her performance in percentage. As is recommended, the nine stanine categories were reduced to five: very poor, fair/below average, good/average, very good/above average and excellent. The discriminatory validity of the norms was substantiated by showing that groups with known nutrition knowledge levels were rated appropriately and that the performance ratings of these groups differed significantly, with university dietetics students scoring 98·3 %, primary-school teachers 20·3 % and non-nutrition university students 31·6 %.ConclusionsThe norm-referenced performance-rating scale can be used with confidence to interpret the performance score achieved by a testee on the nutrition knowledge test developed for urban adolescents in South Africa. The methodology used in the study serves as a prototype for other researchers who are developing knowledge tests.
Lutein concentration in human milk during early lactation and its relationship with dietary lutein intake
Authors: Cena Hellas , Castellazzi Anna Maria , Pietri Amedeo , Roggi Carla , Turconi Giovanna 
Published: February 2009

AbstractObjectiveThe present study aimed to estimate the lutein concentration in human milk during early lactation and its relationship with dietary lutein intake measured through the administration of a short FFQ.DesignA cross-sectional study in which an FFQ was administered twice: on day 3 (T0) and day 30 (T1) postpartum; meanwhile two breast milk samples were collected. Maternal plasma samples were obtained at T0. The comparison of dietary lutein intakes and likewise lutein concentrations in breast milk at T0 and T1 were analysed with Student’sttest. Pearson’s correlation coefficient was used to determine the association between dietary lutein intake and lutein concentration in milk and plasma, respectively, as well as the correlation between breast milk and plasma lutein concentrations at T0.SettingPavia, northern Italy.SubjectsTwenty-one pregnant women, age range 24–42 years, were recruited during their last trimester on a voluntary basis.ResultsBoth breast milk and plasma lutein concentrations were significantly correlated with dietary lutein intake (r= 0·86,P= 0·0001 andr= 0·94,P= 0·0001, respectively). There was a clear significant correlation between milk and plasma lutein concentrations (r= 0·87,P= 0·0001). Mature milk lutein concentration, although significantly reduced at T1 (P< 0·01), maintained a fairly high correlation with dietary lutein intake (r= 0·82,P= 0·0001).ConclusionsEven though milk lutein concentration decreased during early lactation, it remained significantly correlated with daily lutein intake. Therefore, while awaiting further research, dietary recommendations advising intake of fresh fruit and vegetables rich in lutein, throughout the whole duration of pregnancy and lactation, are extremely useful.
Habitual high phosphorus intakes and foods with phosphate additives negatively affect serum parathyroid hormone concentration: a cross-sectional study on healthy premenopausal women
Authors: Kemi Virpi E , Rita Hannu J , Kärkkäinen Merja UM , Viljakainen Heli T , Laaksonen Marika M , Outila Terhi A , Lamberg-Allardt Christel JE 
Published: February 2009

AbstractObjectiveFoods can contain natural phosphorus (NP) and phosphate-containing food additives (AP). The main objective of the present study was to investigate whether NP and AP of habitual diets differ in their effects on markers of Ca metabolism. We also investigated the impact of total habitual dietary P intake on markers of Ca metabolism.DesignCross-sectional study. Fasting blood samples were collected and participants kept a 4 d food record, from which dietary intake of total P and the consumption of NP (milk and cheese, excluding processed cheese) and AP (processed cheese) sources were calculated. Participants were divided into groups according to their NP- and AP-containing food consumption and into quartiles according to their total P intake.SettingSouthern Finland.SubjectsOne hundred and forty-seven healthy premenopausal women aged 31–43 years.ResultsRelative to the lowest total dietary P quartile, mean serum parathyroid hormone (S-PTH) concentration was higher (P= 0·048, analysis of covariance (ANCOVA)) and the mean serum ionized Ca concentration lower (P= 0·016, ANCOVA) in the highest P intake quartile. Mean S-PTH concentrations were higher among participants who consumed processed cheese (P= 0·027, ANCOVA) and less milk and other cheese than processed cheese (P= 0·030, ANCOVA).ConclusionsHigh total habitual dietary P intake affected S-PTH unfavourably. Furthermore, phosphate additives may have more harmful effects on bone than other P sources, as indicated by higher mean S-PTH concentration among participants who consumed AP-containing foods. Because of the high dietary P intake and current upward trend in consumption of processed foods in Western countries, these findings may have important public health implications.
Explicit incorporation of equity considerations into economic evaluation of public health interventions
Authors: COOKSON RICHARD , DRUMMOND MIKE , WEATHERLY HELEN 
Published: February 2009

AbstractHealth equity is one of the main avowed objectives of public health policy across the world. Yet economic evaluations in public health (like those in health care more generally) continue to focus on maximizing health gain. Health equity considerations are rarely mentioned. Health economists rely on the quasi-egalitarian value judgment that ‘a QALY is a QALY’ – that is QALYs are equally weighted and the same health outcome is worth the same no matter how it is achieved or to whom it accrues. This value judgment is questionable in many important circumstances in public health. For example, policy-makers may place rather little value on health outcomes achieved by infringing individual liberties or by discriminating on the basis of age, sex, or race. Furthermore, there is evidence that a majority of the general public wish to give greater weight to health gains accruing to children, the severely ill, and, to a lesser extent, the socio-economically disadvantaged. This paper outlines four approaches to explicit incorporation of equity considerations into economic evaluation in public health: (i) review of background information on equity, (ii) health inequality impact assessment, (iii) analysis of the opportunity cost of equity, and (iv) equity weighting of health outcomes. The first three approaches can readily be applied using standard methods of health technology assessment, where suitable data are available; whereas approaches for generating equity weights remain experimental. The potential benefits of considering equity are likely to be largest in cases involving: (a) interventions that target disadvantaged individuals or communities and are also relatively cost-ineffective and (b) interventions to encourage lifestyle change, which may be relatively ineffective among ‘hard-to-reach’ disadvantaged groups and hence may require re-design to avoid increasing health inequalities.
Low concentration thresholds of plasma membranes for rapid energy-independent translocation of a cell-penetrating peptide
Authors: Watkins Catherine L. , Schmaljohann Dirk , Futaki Shiroh , Jones Arwyn T. 
Published: February 2009

The exact mechanisms by which cell-penetrating peptides such as oligo-arginines and penetratin cross biological membranes has yet to be elucidated, but this is required if they are to reach their full potential as cellular delivery vectors. In the present study, qualitative and quantitative analysis of the influence of temperature, peptide concentration and plasma membrane cholesterol on the uptake and subcellular distribution of the model cell-penetrating peptide octa-arginine was performed in a number of suspension and adherent cell lines. When experiments were performed on ice, the peptide at 2 μM extracellular concentration efficiently entered and uniformly labelled the cytoplasm of all the suspension cells studied, but a 10-fold higher concentration was required to observe similar results in adherent cells. At 37 °C and at higher peptide concentrations, time-lapse microscopy experiments showed that the peptide rapidly penetrated the entire plasma membrane of suspension cells, with no evidence of a requirement for nucleation zones to promote this effect. Cholesterol depletion with methyl-β-cyclodextrin enhanced translocation of octa-arginine across the plasma membrane of suspension cells at 37 °C, but decreased overall peptide accumulation. Under the same conditions in adherent cells this agent had no effect on peptide uptake or distribution. Cholesterol depletion increased the overall accumulation of the peptide at 4 °C in KG1a cells, but this effect could be reversed by re-addition of cholesterol as methyl-β-cyclodextrin–cholesterol complexes. The results highlight the relatively high porosity of the plasma membrane of suspension cells to this peptide, especially at low temperatures, suggesting that this feature could be exploited for delivering bioactive entities.
Influx of Multidrug-Resistant, Gram-Negative Bacteria in the Hospital Setting and the Role of Elderly Patients With Bacterial Bloodstream Infection
Authors: Pop-Vicas Aurora , Tacconelli E. , Gravenstein Stefan , Lu Bing , D'Agata Erika M. C. 
Published: February 2009

Background.Multidrug-resistant (MDR) gram-negative bacteria are reported increasingly frequently among isolates recovered from elderly patients. The clinical epidemiology of bloodstream infection (BSI) due to MDR gram-negative bacteria among elderly patients is unknown.Objective.To characterize the clinical epidemiology of BSI due to MDR gram-negative bacteria among elderly patients at hospital admission in an effort to provide a greater understanding of these serious infections and ultimately to improve patient outcomes.Design.Case-control study.Setting.Tertiary care hospital in Boston, Massachusetts.Patients.Patients 65 years of age and older.Methods.From 1999 to 2007, computerized medical records were reviewed for BSI due to MDR gram-negative bacteria within 48 hours of hospital admission. Risk factors for BSI due to these bacteria were identified.Results.MDR gram-negative bacteria were recovered from 61 (8%) of 724 elderly patients with BSI caused by gram-negative bacteria. Over the -year study period, the percentage of MDR gram-negative bacteria among bloodstream isolates increased from 2 (1%) of 199 to 34 (16%) of 216. Empiric therapy was ineffective for 38 (63%) of 60 patients with BSI caused by MDR gram-negative bacteria. The variables independently associated with BSI due to these bacteria were as follows: residency in a long-term care facility (odds ratio [OR], 4.9 [95% confidence interval {CI} 1.6–14.9]; P = .006), presence of an invasive device (OR, 6.0 [95% CI, 1.5–23.5]; P = .01), severe sepsis (OR, 7.9 [95% CI, 1.7–37.1]; P = .009), and delayed initiation of effective therapy (OR, 12.8 [95% CI, 3.9–41.1]; P<.001).Conclusion.The 16-fold increase in BSI due to MDR gram-negative bacteria at hospital admission among elderly patients, especially among those who resided in long-term care facilities prior to admission, contributes further to the expanding body of evidence that these patients are the main reservoirs of MDR gram-negative bacteria. Given their contribution to the influx of antimicrobial-resistant bacteria in the hospital setting, infection control interventions that target this high-risk group need to be considered.
A dynamic model of colonic concentrations of delayed‐release 5‐aminosalicylic acid (Asacol)
Authors: THORPE M. P. , EHRENPREIS E. D. , PUTT K. S. , HANNON B. 
Published: February 2009

SummaryBackround 5‐ASA in a pH sensitive tablet (Asacol) is administered as three doses/day to treat ulcerative colitis. Once daily dosing may improve patient adherence. Simulation of colonic levels of 5‐ASA can be used to compare dosing regimens.Aim To create a dynamic model of colonic concentrations of delayed‐release 5‐aminosalicylic acid (Asacol).Methods Using published data, we created a computer model with STELLA software to simulate amounts of colonic 5‐ASA in the total colon, right, transverse, descending and sigmoid/rectum after daily and three time/day Asacol.Results The model predicted similar total and regional amounts of 5‐ASA with both regimens. Distribution of 5‐ASA was 38% in the right colon, 33% in the transverse colon and 14% each in the descending and sigmoid/rectal colon. Simulated increases in colonic motility and defecation rate exaggerated this 5‐ASA distribution, resulting in negligible amounts of 5‐ASA in the sigmoid/rectal region.Conclusions This computer model suggests that Asacol can be administered as a single daily dose. The model supports experimental and clinical observations that alternate dose or route of administration may be necessary to achieve adequate 5‐ASA amounts in the distal colon during acute exacerbations of ulcerative colitis. This simulation cannot account for all sources of variability in the clinical setting, but provides a rationale for further investigation.