bluuebunny/crossref_metadata_2025 huggingface dataset:
Experiences and Decisions that Motivate Women at Increased Risk of Breast Cancer to Participate in an Experimental Screening Program
Authors: Proulx Michelle , Beaulieu Marie‐Dominique , Loignon Christine , Mayrand Marie‐Hélène , Maugard Christine , Bellavance Nathalie , Provencher Diane
Published: February 2009

Although the discovery of mutations on BRCA1 and BRCA2 genes associated with high breast cancer risk has given rise to screening and surveillance initiatives, there is little documentation on why high‐risk women choose to enter screening programs. The objective of this qualitative study was to develop a detailed understanding of the experiences and decisions that motivate women with increased risk of hereditary breast cancer to participate in the multicentered Quebec experimental breast screening program. Our study involved 21 participants who were either BRCA carriers or at risk and untested. These women were interviewed while participating in the screening program. Our study demonstrates that intensive screening programs may provide valuable reassurance for women with increased familial risk of hereditary breast cancer, who count on early detection and rapid response from professionals if and when a problem arises. Health professionals must take these and others concerns into account to ensure their interventions are most consistent with women's needs.
Do we need livestock grazing to promote Polylepis australis tree recruitment in the Central Argentinean Mountains?
Authors: Zimmermann Heike , Renison Daniel , Leyer Ilona , Hensen Isabell
Published: February 2009

South American Polylepis mountain forests are endangered due to centuries of logging, fire clearance, and intensive livestock grazing. Polylepis australis (Rosaceae) dominates the tree canopy in the Central Argentinean Mountains, where livestock have been excluded or reduced to very low densities over wide areas. Lowered plant and bird diversity in these abandoned grazing areas suggest that some livestock grazing may be beneficial for conservation purposes. Our study aimed to determine whether this may also be true for forest regeneration. In 300 plots of 1 m2 distributed in sub‐regions of high to moderate grazing pressure as well as grazing exclusion, we recorded the presence of P. australis seedlings and grazing indicators. Topographical parameters as well as vegetation and soil characteristics were also assessed. Seedling frequencies were highest in the region with moderate grazing, intermediate with grazing exclusion, and the lowest with high grazing pressures. Logistic regression models revealed that seedling occurrence was highest close to seeder trees, with intermediate litter coverage and at intermediate altitudes above sea level. Since grazing ultimately affects seeder tree occurrence through browsing and reduces litter cover and predominates in higher areas, we conclude that grazing is an important driving factor for P. australis regeneration. We confirm previous studies determining high grazing pressure to be detrimental for P. australis regeneration, but also provide data suggesting that its complete exclusion may not be recommendable either. Management should aim to alternate between a moderate grazing intensity to promote seedling recruitment, with subsequent exclusion to accelerate the growth of the established seedlings.
Critical Evaluation of Product Ion Selection and Spectral Correlation Analysis for Biomarker Screening Using Targeted Peptide Multiple Reaction Monitoring
Authors: Liu Jian , Hewel Johannes A. , Fong Vincent , Chan-Shen-Yue Michelle , Emili Andrew
Published: February 2009

Introduction

Tandem mass spectrometry (MS/MS) has emerged as a cornerstone of proteomic screens aimed at discovering putative protein biomarkers of disease with potential clinical applications. Systematic validation of lead candidates in large numbers of samples from patient cohorts remains an important challenge. One particularly promising high throughout technique is multiple reaction monitoring (MRM), a targeted form of MS/MS by which precise peptide precursor–product ion combinations, or transitions, are selectively tracked as informative probes. Despite recent progress, however, many important computational and statistical issues remain unresolved. These include the selection of an optimal set of transitions so as to achieve sufficiently high specificity and sensitivity when profiling complex biological specimens, and the corresponding generation of a suitable scoring function to reliably confirm tentative molecular identities based on noisy spectra.

Methods

In this study, we investigate various empirical criteria that are helpful to consider when developing and interpreting MRM-style assays based on the similarity between experimental and annotated reference spectra. We also rigorously evaluate and compare the performance of conventional spectral similarity measures, based on only a few pre-selected representative transitions, with a generic scoring metric, termed T
corr, wherein a selected product ion profile is used to score spectral comparisons.

Conclusions

Our analyses demonstrate that T
corr is potentially more suitable and effective for detecting biomarkers in complex biological mixtures than more traditional spectral library searches.
Inhibition of apoptosis by ascorbic and dehydroascorbic acids in Xenopus egg extracts
Authors: Saitoh Tomohiro , Tsuchiya Yuichi , Kinoshita Toshihiko , Itoh Motohiro , Yamashita Shigeru
Published: February 2009

Purpose

The viability of mammalian eggs after ovulation is reported to be improved by the presence of ascorbic acid in the culture medium. However, the pro‐survival mechanisms of ascorbic acid are poorly understood. The molecular pathways of apoptosis are evolutionarily conserved among animal species, and Xenopus eggs are technically and ethically more suitable for biochemical analyses than mammalian eggs. We used Xenopus egg cytoplasmic extracts to examine the direct intracellular effects of ascorbic acid.

Methods

Incubation of egg extracts for more than 4 h induces the spontaneous release of cytochrome c from mitochondria. This event triggers the activation of caspases, cleavage of substrate proteins, and execution of apoptosis. Multiple signal transduction pathways including proteolysis and protein phosphorylation are also involved in this process. We examined whether any of these events might be inhibited by the addition of ascorbic acid.

Results

Ascorbic acid showed no effect against cytochrome c release, but prevented caspase activation and substrate cleavage. Ascorbic acid also blocked the proteolysis of apoptosis inhibitor proteins and the dephosphorylation of p42 MAP kinase. However, dehydroascorbic acid (oxidized form of ascorbic acid) and acetate (unrelated acid) were equally effective, indicating that these effects were primarily due to their acidity. In addition, dehydroascorbic acid inhibited caspase activities directly in vitro.

Conclusions

The anti‐apoptotic effect of ascorbic acid in Xenopus egg extracts is mainly due to cytoplasmic acidification rather than its intracellular antioxidant activity. Instead, oxidative conversion of ascorbic acid into dehydroascorbic acid may inhibit apoptosis through the inhibition of caspases.
Effect of glutathione on the development of rat embryos following microinsemination
Authors: Yuzawa K. , Sawada T. , Hossain M. S. , Takagi Y. , Hamano K. , Tsujii H.
Published: February 2009

Purpose

The present study was carried out to evaluate the role of glutathione on rat embryo developmental potential after ICSI. We observed the effects of glutathione on the development of non‐treated rat embryos, ICSI embryos and embryos with sham injection treatment. The development of glutathione‐microinjected embryos was also observed.

Methods

Oocytes and fertilized embryos were obtained from superovulated Wistar–Imamichi rats and cultured in mR1ECM medium. Oocytes and embryos were then allowed to develop to assess the effect of glutathione on the development rate in intact embryos, micro‐injected embryos and ICSI embryos.

Results

(1) In the intact embryo, the proportion of blastocyst stage development increased when 0.01 mM GSH was added to the medium compared to the control. (2) Microinjection of glutathione (GSSG, GSH) into the embryo increased development at each stage, and the addition of 0.2 nM GSSG or GSH significantly increased blastocyst development, in comparison to that of the control (P < 0.05). (3) Compared to the control, all the GSSG and GSH concentrations improved damaged blastocyst development, where 0.01 mM GSH improved significantly (P < 0.05). (4) The addition of glutathione in the medium increased the rate of blastocyst development after ICSI. A significantly higher number of TE and total cells were obtained in the micro‐injected embryo with both of the 0.02 mM GSSG and GSH treatments (P < 0.05).

Conclusions

The addition of glutathione into the culture media can improve early embryo development and is capable of repairing the damage of ICSI rat embryos.
The dilemma faced by patients who undergo single embryo transfer
Authors: Sugiyama Rikikazu , Nakagawa Koji , Nishi Yayoi , Sugiyama Rie , Ezaki Kei , Inoue Masato
Published: February 2009

Purpose

The aim of this study was to identify the factors that contribute to the decision to choose single embryo transfer (SET).

Methods

Two hundred and nine patients who underwent ART treatment in our clinics between April 2006 and May 2007 were enrolled in this study. All patients had elected to undergo SET before the start of each treatment cycle; a questionnaire was administered to all patients prior to the SET procedure.

Results

The mean age of the patients was 34.6 years old (range: 24–45 years). The mean number of redundant embryos was 3.7 (range: 1–17), and the pregnancy rate per embryo transfer was 25.7%. A total of 121 patients (57.9%) who underwent SET returned their questionnaires. Based on the results of questionnaire, 56.2% of patients who received SET waived their right to choose between single and double embryo transfer. Among patients who selected SET, 67.6% believed that the pregnancy rate resulting from double embryo transfer (DET) is significantly greater than that associated with SET, and 25% of patients wanted to have twins. The majority of patients (80.9%) who underwent SET understood that multi‐fetal pregnancy increases the risk of complications during gestation and delivery. Among all patients who completed the questionnaire, 72.8% believed that the number of transferred embryos should not be controlled by law.

Conclusions

The results of the present study show that greater than one‐half of patients who underwent SET were faced with a dilemma––the difficult choice between their own desires and their clinician's recommendation.
Oxaliplatin enhances TRAIL‐induced apoptosis in gastric cancer cells by CBL‐regulated death receptor redistribution in lipid rafts
Authors: Xu Ling , Qu Xiujuan , Zhang Ye , Hu Xuejun , Yang Xianghong , Hou Kezuo , Teng Yuee , Zhang Jingdong , Sada Kiyonao , Liu Yunpeng
Published: February 2009

Tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) is a member of the tumor necrosis factor family that selectively induces apoptosis in cancer cells. However, gastric cancer cells are insensitive to TRAIL. In the present study, we show that oxaliplatin enhanced TRAIL‐induced apoptosis of MGC803, BGC823, and SGC7901 cells. Oxaliplatin promoted death receptor 4 (DR4) and death receptor 5 (DR5) clustering into aggregated lipid rafts, while the cholesterol‐sequestering agent nystatin partially prevented lipid raft aggregation, DR4 and DR5 clustering, and reduced apoptosis. Furthermore, the expression of the casitas B‐lineage lymphoma (Cbl) family was downregulated by oxaliplatin. Transfection of c‐Cbl or Cbl‐b partially reversed oxaliplatin‐induced lipid raft aggregation. These results indicated that oxaliplatin enhanced TRAIL‐induced gastric cancer cell apoptosis at least partially through Cbl‐regulated death receptor redistribution in lipid rafts.
Molecular and functional characterization of the plastid‐localized Phosphoenolpyruvate enolase (ENO1) from Arabidopsis thaliana
Authors: Prabhakar Veena , Löttgert Tanja , Gigolashvili Tamara , Bell Kirsten , Flügge Ulf-Ingo , Häusler Rainer E.
Published: February 2009

The Arabidopsis thaliana gene At1g74030 codes for a putative plastid phosphoenolpyruvate (PEP) enolase (ENO1). The recombinant ENO1 protein exhibited enolase activity and its kinetic properties were determined. ENO1 is localized to plastids and expressed in most heterotrophic tissues including trichomes and non‐root‐hair cells, but not in the mesophyll of leaves. Two T‐DNA insertion eno1 mutants exhibited distorted trichomes and reduced numbers of root hairs as the only visible phenotype. The essential role of ENO1 in PEP provision for anabolic processes within plastids, such as the shikimate pathway, is discussed with respect to plastid transporters, such as the PEP/phosphate translocator.
Effects of the flaxseed lignans secoisolariciresinol diglucoside and its aglycone on serum and hepatic lipids in hyperlipidaemic rats
Authors: Felmlee M. A. , Woo G. , Simko E. , Krol E. S. , Muir A. D. , Alcorn J.
Published: February 2009

The present study involved a comparative analysis of the effects of purified flaxseed lignans, secoisolariciresinol diglucoside (SDG) and its aglycone metabolite (SECO), in hyperlipidaemic rats. For hypercholesterolaemia, female Wistars (six rats per group) were fed a standard or 1 % cholesterol diet and orally administered 0, 3 or 6 mg SDG/kg or 0, 1·6 or 3·2 mg SECO/kg body weight once daily for 4 weeks. Hypertriacylglycerolaemia was induced in male Sprague–Dawley rats (ten rats per group) by supplementing tap water with 10 % fructose. These rats were orally administered 0, 3 or 6 mg SDG/kg body weight once daily for 2 weeks. Fasting blood samples (12 h) were collected predose and at the end of the dosing period for serum lipid analyses. Rats were killed and livers rapidly excised and sectioned for lipid, mRNA and histological analyses. Chronic administration of equimolar amounts of SDG and SECO caused similar dose-dependent reductions in rate of body-weight gain and in serum total and LDL-cholesterol levels and hepatic lipid accumulation. SDG and SECO failed to alter hepatic gene expression of commonly reported regulatory targets of lipid homeostasis. SDG had no effect on serum TAG, NEFA, phospholipids and rate of weight gain in 10 % fructose-supplemented rats. In conclusion, our data suggest that the lignan component of flaxseed contributes to the hypocholesterolaemic effects of flaxseed consumption observed in humans. Future studies plan to identify the biochemical mechanism(s) through which flaxseed lignans exert their beneficial effects and the lignan form(s) responsible.
Theropod teeth from the basalmost Cretaceous of Anoual (Morocco) and their palaeobiogeographical significance
Authors: KNOLL F. , RUIZ-OMEÑACA J. I.
Published: February 2009

The theropod teeth from the Berriasian (Early Cretaceous) site of Anoual (N Morocco) are described. The assemblage is important in that it comes from one of the very few dinosaur sites of this age globally and the only one for the whole of Gondwana. The theropod teeth from Anoual are morphologically diverse. Most of the material possibly belongs to the clade Dromaeosauridae, which would be an early occurrence for this taxon. The palaeogeographic position of Anoual enables it to provide data on the dispersal events that affected terrestrial faunas during Mesozoic times. A Laurasian influence is evidenced by the presence of Velociraptorinae and, on the whole, the theropod fauna from Anoual provides support for the existence of a trans-Tethyan passage allowing terrestrial faunal interchanges during Late Jurassic and/or earliest Cretaceous times. Additionally, Anoual records the existence of diminutive theropods. However, it cannot yet be determined whether the small size of the specimens is genetic or ontogenetic.
Causes of intraspecific variation in body size among trematode metacercariae
Authors: Saldanha I. , Leung T.L.F. , Poulin R.
Published: February 2009

Inequalities in body size among adult helminths can result in inequalities in reproductive output, with consequences for population dynamics and genetics. These inequalities can result from growth differences among larval worms inside intermediate hosts that persist into the adult stage. Here, we investigate the effects of both host body size and intensity of infection on the sizes of metacercariae of the trematode Maritrema novaezealandensis (Microphallidae) inside their second intermediate host, the isopod Paridotea ungulata (Idoteidae). Among the more than 1500 metacercariae recovered and individually measured, there was no relationship between the mean diameter of metacercarial cysts per isopod and isopod body length. However, intensity of infection correlated negatively with the mean diameter of cysts within an isopod, i.e. metacercariae in crowded infections attained smaller sizes on average. In contrast, the variability in cyst sizes per isopod, measured as the coefficient of variation, was independent of both isopod body length and infection intensity. Our results show that a disproportionate number of relatively small metacercariae come from the relatively few hosts in which a large fraction of all metacercariae are aggregated. The combination of aggregation and intensity-dependent growth generates inequalities in sizes among metacercariae that will be passed on to adult worm populations in definitive hosts.
Predatory activity of the fungi Duddingtonia flagrans, Monacrosporium thaumasium, Monacrosporium sinense and Arthrobotrys robusta on Angiostrongylus vasorum first-stage larvae
Authors: Braga F.R. , Carvalho R.O. , Araujo J.M. , Silva A.R. , Araújo J.V. , Lima W.S. , Tavela A.O. , Ferreira S.R.
Published: February 2009

Angiostrongylus vasorum is a nematode that parasitizes domestic dogs and wild canids. We compared the predatory capacity of isolates from the predatory fungi Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34), Monacrosporium sinense (SF53) and Arthrobotrys robusta (I31) on first-stage larvae (L1) of A. vasorum under laboratory conditions. L1A. vasorum were plated on 2% water-agar (WA) Petri dishes marked into 4 mm diameter fields with the four grown isolates and a control without fungus. Plates of treated groups contained each 1000 L1A. vasorum and 1000 conidia of the fungal isolates AC001, NF34, SF53 and I31 on 2% WA. Plates of the control group (without fungus) contained only 1000 L1A. vasorum on 2% WA. Ten random fields (4 mm diameter) were examined per plate of treated and control groups, every 24 h for 7 days. Nematophagous fungi were not observed in the control group during the experiment. There was no variation in the predatory capacity among the tested fungal isolates (P>0.05) during the 7 days of the experiment. There was a significant reduction (P < 0.05) of 80.3%, 74.5%, 74.2% and 71.8% in the means of A. vasorum L1 recovered from treatments with isolates AC001, NF34, SF53 and I31, respectively, compared to the control without fungi. In this study, the four isolates of predatory fungi were efficient in the in vitro capture and destruction of A. vasorum L1, confirming previous work on the efficiency of nematophagous fungi in the control of nematode parasites of dogs and as a possible alternative method of biological control.
Management of dysphonia in children
Authors: Connelly A , Clement W A , Kubba H
Published: February 2009

Background:

Dysphonia is common in children, but practice varies considerably regarding what, if any, investigations are performed and how the condition is managed. Although childhood dysphonia is mostly due to non-serious causes such as voice misuse, very serious pathology such as papillomatosis or malignancy needs occasionally to be excluded, and treatable congenital anomalies such as webs and cysts can be missed. Voice clinics and voice therapy services are now well established in most adult health services in the developed world, but equivalent services for children are less common, at least in the UK.

Methods:

We retrospectively reviewed the records of all children presenting to our large children's hospital with a primary complaint of dysphonia between January 2001 and October 2007, in order to determine their management, investigations and final diagnosis.

Results:

We identified 142 children. Case records were found for 137 (97 per cent). Eight-three children were male (61 per cent) and 54 female (39 per cent). Ages ranged from two months to 15 years (median 5.3 years). In 10 children (7 per cent), hoarseness was congenital, presenting as a hoarse, weak cry at birth. In 15 children (11 per cent), onset of hoarseness was related to a specific surgical procedure. The larynx was visualised by mirror alone in 23 children (17 per cent), by awake fibre-optic laryngoscopy in 27 (20 per cent) and by microlaryngoscopy-bronchoscopy under anaesthesia in 42 (31 per cent). Forty children (29 per cent) did not undergo laryngeal visualisation at any time and were diagnosed based on history alone. A further five (4 per cent) were scheduled for direct laryngoscopy but this was not performed due to resolution of symptoms. Voice abuse accounted for 62 (45 per cent) of all diagnoses.

Conclusions:

Childhood dysphonia accounts for a large number of referrals. There is considerable variation in how these children are managed. A more structured approach to diagnosis and investigation would be beneficial, perhaps within the setting of a dedicated paediatric voice clinic.
Anatomical variation of internal carotid artery presenting as pharyngeal mass
Authors: Leong S C , Luff D A
Published: February 2009

Objective:

We describe a case of an internal carotid artery loop presenting as an oropharyngeal mass.

Method:

Case report and review of current literature.

Case report:

A 71-year-old woman presented with an asymptomatic oropharyngeal mass. This was an incidental finding by her general practitioner and was urgently referred as a suspicious lesion. A magnetic resonance imaging scan revealed an internal carotid artery tonsillar kink indenting into the pharyngeal wall. No further treatment was necessary.

Conclusion:

The internal carotid kink is an important anatomical variation which ENT surgeons should be aware of, as there are significant complications if blind biopsy is undertaken prior to appropriate imaging.
Novel method for safe cauterisation of posterior epistaxis
Authors: Judd O
Published: February 2009

Introduction:

In epistaxis, anterior bleeding points are easily cauterised under direct vision, but those which occur in the posterior nose present a greater challenge. Standard cautery techniques limit simultaneous use of other equipment in the narrow posterior nose.

Methods:

This article presents a novel device which combines suction, cautery stick and sheath in one single-handed implement for ease of use.

Conclusion:

This novel, hand-held device for simultaneous suction and safe cautery of posterior epistaxis is both safe and cost-effective. It enables successful treatment by a single operator and is relatively easy to use by the non-skilled, junior trainee.
Peroral drainage of post-traumatic sialocoeles: report of three cases
Authors: Edkins O , van Lierop A C , Fagan J J , Lubbe D E
Published: February 2009

Objective:

To discuss the technique and outcome of this simple procedure and the management of post-traumatic parotid sialocoeles, and to review the literature regarding this condition.

Case report:

We report the successful surgical treatment, by peroral drainage, of three patients with post-traumatic parotid sialocoele resistant to conservative management.

Discussion:

We discuss the method and outcome of the surgical procedure performed, along with the causes, presentation and management of parotid sialocoele.

Conclusion:

Correct initial management of a parotid duct injury may prevent the formation of a sialocoele. When conservative treatment of post-traumatic parotid sialocoele fails, we advocate the surgical technique described in this report as it is effective, simple and carries minimal risk to the patient.
Tick-induced blood loss leads to regenerative anaemia in the European hedgehog (Erinaceus europaeus)
Authors: PFÄFFLE M. , PETNEY T. , ELGAS M. , SKUBALLA J. , TARASCHEWSKI H.
Published: February 2009

Although there is an increasing understanding of the role of parasites in their host dynamics, accurate, quantitative estimates of parasite caused morbidity in wild animals are rare. Here, we examine the possible impact of 2 tick species (Ixodes ricinus, I. hexagonus) on the condition of the European hedgehog (Erinaceus europaeus). For this, we tested for correlations between blood parameters of 36 adult hedgehogs from an experimental population enclosed in a natural habitat and their tick infestation over a period of 8 months (March–October 2007). We found correlations between the tick infestation and the concentration of red blood cells, haemoglobin, haematocrit, MCH, MCHC, thrombocytes, lymphocytes and neutrophils. These results indicate that ticks can induce anaemia in the hedgehog. The peripheral blood characteristics and the erythrocyte indices characterize this anaemia as haemorrhagic and regenerative. During the course of our study the hedgehogs of our population showed below normal mortality but morbidity was found to be high resulting from the blood loss caused by the feeding activity of the ticks.
American students abroad: Negotiation of difference?
Authors: Kinginger Celeste
Published: February 2009

This paper considers the ways in which American students' active engagement in local host communities abroad is at risk. Constraining forces include the new demographics of American study abroad, prejudicial attitudes toward international education and sheltered program designs, a research enterprise committed to representing the perspectives of students primarily, and the influence of globalization on communicative practice and habits of thought. To counter these influences, the elements of an activist stance are proposed.
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.
AN M/G/1 RETRIAL QUEUE WITH UNRELIABLE SERVER FOR STREAMING MULTIMEDIA APPLICATIONS
Authors: Sherman Nathan P. , Kharoufeh Jeffrey P. , Abramson Mark A.
Published: February 2009

As a model for streaming multimedia applications, we study an unreliable retrial queue with infinite-capacity orbit and normal queue for which the retrial rate and the server repair rate are controllable. Customers join the retrial orbit if and only if their service is interrupted by a server failure. Interrupted customers do not rejoin the normal queue but repeatedly attempt to access the server at independent and identically distributed intervals until it is found functioning and idle. We provide stability conditions, queue length distributions, stochastic decomposition results, and performance measures. The joint optimization of the retrial and server repair rates is also studied.
USING SINGULARITY ANALYSIS TO APPROXIMATE TRANSIENT CHARACTERISTICS IN QUEUEING SYSTEMS
Authors: Walraevens Joris , Fiems Dieter , Moeneclaey Marc
Published: February 2009

In this article, we develop a simple method to approximate the transient behavior of queueing systems. In particular, it is shown how singularity analysis of a known generating function of a transient sequence of some performance measure leads to an approximation of this sequence. To illustrate our approach, several specific transient sequences are investigated in detail. By means of some numerical examples, we validate our approximations and demonstrate the usefulness of the technique.
DYNAMIC PRICING TO CONTROL LOSS SYSTEMS WITH QUALITY OF SERVICE TARGETS
Authors: Hampshire Robert C. , Massey William A. , Wang Qiong
Published: February 2009

Numerous examples of real-time services arise in the service industry that can be modeled as loss systems. These include agent staffing for call centers, provisioning bandwidth for private line services, making rooms available for hotel reservations, and congestion pricing for parking spaces. Given that arriving customers make their decision to join the system based on the current service price, the manager can use price as a mechanism to control the utilization of the system. A major objective for the manager is then to find a pricing policy that maximizes total revenue while meeting the quality of service targets desired by the customers. For systems with growing demand and service capacity, we provide a dynamic pricing algorithm. A key feature of our solution is congestion pricing. We use demand forecasts to anticipate future service congestion and set the present price accordingly.
Contour statistics in natural images: Grouping across occlusions
Authors: GEISLER WILSON S. , PERRY JEFFREY S.
Published: February 2009

Correctly 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

The 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

The 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.
Bifurcation analysis of the twist-Fréedericksz transition in a nematic liquid-crystal cell with pre-twist boundary conditions
Authors: DA COSTA FERNANDO P. , GARTLAND EUGENE C. , GRINFELD MICHAEL , PINTO JOÃO T.
Published: February 2009

Motivated by a recent investigation of Millar and McKay [Director orientation of a twisted nematic under the influence of an in-plane magnetic field.Mol. Cryst. Liq.Cryst435, 277/[937]–286/[946] (2005)], we study the magnetic field twist-Fréedericksz transition for a nematic liquid crystal of positive diamagnetic anisotropy with strong anchoring and pre-twist boundary conditions. Despite the pre-twist, the system still possesses ℤ2symmetry and a symmetry-breaking pitchfork bifurcation, which occurs at a critical magnetic-field strength that, as we prove, is above the threshold for the classical twist-Fréedericksz transition (which has no pre-twist). It was observed numerically by Millar and McKay that this instability occurs precisely at the point at which the ground-state solution loses its monotonicity (with respect to the position coordinate across the cell gap). We explain this surprising observation using a rigorous phase-space analysis.
PROTEOMICS APPROACHES IN PRE-ECLAMPSIA RESEARCH
Authors: CLANCY OLIVIA , MYERS JENNY E.
Published: February 2009

Much of our current understanding of human gestation is largely based on information extracted from animal and cell models. Although this information has been fundamental for progression of reproductive research, much of it examines biological molecules in isolation rather than the integrated manner in which they function. Disruption to these fundamental processes is the source of pregnancy complications, of which for many (including pre-eclampsia) the exact aetiology has not been fully elucidated. We need to re-examine the limited way by which we approach these problems, and aim to understand pathophysiology in a more inclusive/holistic way.
Is Law Coercive?
Authors: Edmundson William A.
Published: February 2009

That lawiscoercive is something we all more or less take for granted. It is an assumption so rooted in our ways of thinking that it is taken as a given of social reality, an uncontroversial datum. Because it is so regarded, it is infrequently stated, and when it is, it is stated without any hint of possible complications or qualifications. I will call this the “prereflective view,” and I want to examine it with the care it deserves.
Deciding Who Decides Who Dies: Capital Punishment as a Social Choice Problem
Authors: Schwartz Edward P. , Schwartz Warren F.
Published: February 2009

This article is about decision making by juries in capital cases. A jury is a collection of individuals who may possess differing views about factors relevant to the task before them, but who must, nonetheless, arrive collectively at a decision. As such, the members of the jury face a classic social choice problem. We investigate how this problem is likely to be resolved under various institutional regimes, differentiated by the set of individuals who are allowed to participate and the decision rule controlling their activities. As in our previous paper analyzing decision making by juries, we focus here on an aspect of the process that has been neglected in judicial opinions and academic scholarship: namely to what extent, and how, persistent disagreement among jurors can and will be resolved.
Lower Court Application of the “Overruling Law” of Higher Courts
Authors: Rogers John M.
Published: February 2009

The obligation of a court to follow the law of a superior court is commonly taken to be stronger than the obligation of the higher court to respect its own precedent. The Supreme Court has recently asserted this stronger obligation in the most forceful terms. What follows is an attempt to demonstrate that this is wrong as a matter of policy and as a matter of law.
How Liberal is Liberal Equality?:A Comment on Ronald Dworkin's Tanner Lecture
Authors: Sherwin Emily
Published: February 2009

Liberalism is a wonderful theory, but its adherents have a difficult time explaining why. In his Tanner Lecture entitledFoundations of Liberal Equality, Ronald Dworkin proposes to defend liberalism in a new way. Dworkin is not content to view liberalism as a political compromise in which people set aside their personal convictions in the interest of social peace. Instead, he undertakes to make liberal political theory “continuous” with personal ethics, by describing an ethical position that endorses liberalism as a matter of conviction.
Why Feminist Epistemology Isn't (And the Implications for Feminist Jurisprudence)
Authors: Richards Janet Radcliffe
Published: February 2009

Twenty years ago, when feminism was younger and greener, crides who thought the movement was sinking into a quagmire of unscientific irrationality had a relatively easy time in making out their case. In the first place, many feminists were themselves claiming to have rejected both science and reason, along with morality and all other such male devices for the oppression of women. And, furthermore, this position was a relatively easy one for the skeptical outsider to attack. Unless feminists could say such things as that the present treatment of women was morally wrong, or prevailing ideas about their nature false or unfounded, or traditional reasoning about their position confused or fallacious, it was difficult to see on what basis they could rest the feminist case. And, of course, as they did say such things, all the time, it was obvious that any systematic attempt to reject ethics and rationality was systematically undercut by feminists' own arguments.
The Self: Metaphysical not Political
Authors: Luban David
Published: February 2009

According to communitarian antiliberals, liberalism is fatally marred by a false metaphysics of the self. Liberalism, communitarians charge, regards the self as atomistic, isolated, presocial, ahistorical, “Cartesian,” Crusoeesque, essentially independent of other selves—in Michael Sandel's felicitous word, “unencumbered.” In reality, the self is constituted by relationships with others, hence by its contingent history. The self is fundamentally historical and social, and a true metaphysics of the self would, in the words of George Fletcher, take “relationships as logically prior to the individual.” Sandel puts it thus: “Can we view ourselves as independent selves, independent in the sense that our identity is never attached to our aims and attachments? I do not think we can….”
Marmor on Meaning, Interpretation, and Legislative Intention
Authors: Goldsworthy Jeffrey
Published: February 2009

In his recent bookInterpretation and Legal Theory, Andrei Marmor makes a number of claims about meaning and interpretation, both in general and in law, which I will argue are mistaken. Actually, there is some confusion in his book between what I take to be his “official” view of the nature of meaning and interpretation, and a very different view which keeps surfacing despite his official rejection of it. I will argue that this alternative, rejected view, when properly developed, is more plausible than his official view, and that the difference between them is of considerable practical consequence for legal interpretation. What is at stake is the role of legislative intention. The alternative view denies Marmor's claim that the meaning of a statute is conceptually independent of the intention or purpose which the legislature had in enacting it. It should be said at the outset that I will focus on just three of the eight chapters in Marmor's book, which contains many virtues that are untouched by my critique.
Conceptual Questions and Jurisprudence
Authors: Bix Brian
Published: February 2009

Conceptual analysis is an integral part of legal theory, but the nature and purpose of such inquiries are often not clearly stated. In this article, I attempt to elaborate upon some of the differing reasons for conceptual analysis and what consequences may follow from choosing one objective rather than another. By showing that divergent purposes are often present in competing analyses of the same concept, I also hope to indicate why some “debates” in the jurisprudential literature are best understood as theorists talking past one another.
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); and

4. Legitimaterationaloperations that can be performed on facts and rules of law to finally yield particular decisions (e.g., deductive reasoning).
Speech, Truth, and the Free Market for Ideas
Authors: Goldman Alvin I. , Cox James C.
Published: February 2009

This article examines a thesis of interest to social epistemology and some articulations of First Amendment legal theory: that a free market in speech is an optimal institution for promoting true belief. Under our interpretation, the market-for-speech thesis claims that more total truth possession will be achieved if speech is regulatedonlyby free market mechanisms; that is, both government regulation and private sector nonmarket regulation are held to have information-fostering properties that are inferior to the free market. After discussing possible counterexamples to the thesis, the article explores the actual implications of economic theory for the emergence of truth in a free market for speech. When confusions are removed about what is maximized by perfectly competitive markets, and when adequate attention is paid to market imperfections, the failure of the market-for-speech thesis becomes clear. The article closes by comparing the properties of a free market in speech with an adversarial system of discourse.
The Legal Regulation of Religious Groups
Authors: Posner Eric A.
Published: February 2009

Although much legal scholarship discusses the meaning of the religion clauses of the U.S. Constitution, very few articles analyze the ways in which state regulation affects actors' incentives to engage in religious behavior. Yet the question of how a law influences religious behavior is important for determining whether various laws are desirable, and whether they violate constitutional constraints. This article draws on recent economic models of religious organization to analyze the ways in which laws affect the behavior of religious groups. Religious groups produce collective goods for their members, and the effect of laws can be analyzed by examining how they modify the payoffs members receive for cooperating or free riding. The article examines the use of laws to establish religious groups, to subsidize them with cash or tax benefits, to provide accommodations for them, to provide symbolic support for them, to provide secular substitutes for the collective goods they produce, and to regulate disputes between members. The article also briefly discusses the constitutional implications of the analysis.
“Strictly Speaking—It Went Without Saying”
Authors: Langille Brian , Ripstein Arthur
Published: February 2009

Herbert Simon once observed that watching an ant make its way across the uneven surface of a beach, one can easily be impressed—too impressed—with the foresight and complexity of the ant's internal map of the beach. Simon went on to point out that such an attribution of complexity to the ant makes a serious mistake. Most of the complexity is not in the ant but in the beach. The ant is just complex enough to use the features of the beach to find its way.
Consent and Sexual Relations
Authors: Wertheimer Alan
Published: February 2009

This article has two broad purposes. First, as a political philosopher who has been interested in the concepts of coercion and exploitation, I want to consider just what the analysis of the concept of consent can bring to the question, what sexually motivated behavior should be prohibited through the criminal law? Put simply, I shall argue that conceptual analysis will be of little help. Second, and with somewhat fewer professional credentials, I shall offer some thoughts about the substantive question itself. Among other things, I will argue that it is a mistake to think that sexual crimes are about violence rather than sex and that we need to understand just why the violation of sexual autonomy is a serious wrong. I shall also argue that the principle that “no means no” does not tell us when “yes means yes,” and that it is the latter question that poses the most interesting theoretical difficulties about coercion, misrepresentation, and competence. In addition, I shall make some brief remarks concerning two questions about consent and sexual relations that lie beyond the criminal law: What “consent compromising behaviors” should be regarded as indecent, although not criminal? Whenshouldsomeone consent to sexual relations within an enduring relationship?
For a Negative, Normative Model of Consent, With a Comment on Preference-Skepticism
Authors: Dripps Donald
Published: February 2009

Let me begin by admitting that I am wary of any comprehensive definition of consent. This bias stems from my professional concentration on criminal law, in which nouons of freedom and responsibility play vital roles in a wide range of contexts. In each context, however, one discovers that freedom means something different. A voluntary act is any bodily movement not caused by external force or nervous disorder. On the other hand, a voluntary act, however horrific its results, ordinarily may be punished only if the actor was subjectively aware that the act was wrong. In any event, a voluntary act may be excused as the product of duress if another person procures the actor's cooperation in the crime by an illegal threat that would overcome the resistance of a person of ordinary firmness.
The Moral Magic of Consent (II)
Authors: Alexander Larry
Published: February 2009

I begin my analysis of consent by agreeing with Professor Hurd that consent functions as a “moral transformative” by altering the obligations and permissions that determine the Tightness of others' actions. I further agree with her that consent is intimately related to the capacity for autonomous action; one who cannot alter others' obligations through consent is not fully autonomous. I cannot improve on her elaboration of these points.