bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a pig femoral head osteonecrosis model
Authors: Zhang Ping , Liang Yun , Kim Harry , Yokota Hiroki
Published: March 2010

Background

A major cause of osteonecrosis of the femoral head is interruption of a blood supply to the proximal femur. In order to evaluate blood circulation and pathogenetic alterations, a pig femoral head osteonecrosis model was examined to address whether ligature of the femoral neck (vasculature deprivation) induces a reduction of blood circulation in the femoral head, and whether transphyseal vessels exist for communications between the epiphysis and the metaphysis. We also tested the hypothesis that the vessels surrounding the femoral neck and the ligamentum teres represent the primary source of blood flow to the femoral head.

Methods

Avascular osteonecrosis of the femoral head was induced in Yorkshire pigs by transecting the ligamentum teres and placing two ligatures around the femoral neck. After heparinized saline infusion and microfil perfusion via the abdominal aorta, blood circulation in the femoral head was evaluated by optical and CT imaging.

Results

An angiogram of the microfil casted sample allowed identification of the major blood vessels to the proximal femur including the iliac, common femoral, superficial femoral, deep femoral and circumflex arteries. Optical imaging in the femoral neck showed that a microfil stained vessel network was visible in control sections but less noticeable in necrotic sections. CT images showed a lack of microfil staining in the epiphysis. Furthermore, no transphyseal vessels were observed to link the epiphysis to the metaphysis.

Conclusion

Optical and CT imaging analyses revealed that in this present pig model the ligatures around the femoral neck were the primary cause of induction of avascular osteonecrosis. Since the vessels surrounding the femoral neck are comprised of the branches of the medial and the lateral femoral circumflex vessels, together with the extracapsular arterial ring and the lateral epiphyseal arteries, augmentation of blood circulation in those arteries will improve pathogenetic alterations in the necrotic femoral head. Our pig model can be used for further femoral head osteonecrosis studies.
The effect of the combination of acids and tannin in diet on the performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs
Authors: Štukelj Marina , Valenčak Zdravko , Krsnik Mladen , Svete Alenka Nemec
Published: March 2010

Background

The abolition of in-feed antibiotics or chemotherapeutics as growth promoters have stimulated the swine industry to look for alternatives such as organic acids, botanicals, probiotics and tannin. The objective of the present study was to compare the effects of a combination of acids and tannin with diet with organic acids and diet without growth promoters on the growth performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs. Tannin is more natural and cheaper but possibly with the same effectiveness as organic acids with regard to growth performance.

Methods

Thirty-six 7 week old grower pigs, divided into three equal groups, were used in a three week feeding trial. Group I was fed basal diet, group II basal diet with added organic acids and group III basal diet with added organic and inorganic acids and tannin. Pigs were weighed before and after feeding and observed daily. Blood was collected before and after the feeding trial for the determination of selected biochemical, haematological and antioxidant enzyme parameters. One-way ANOVA was used to assess any diet related changes of all the parameters. Paired t-test was used to evaluate changes of blood parameters individually in each group of growers before and after feeding.

Results

No clinical health problems related to diet were noted during the three week feeding trial. The average daily gain (ADG) and selected blood parameters were not affected by the addition to basal diet of either acids and tannin or of organic acids alone. Selected blood parameters remained within the reference range before and after the feeding trial, with the exception of total serum proteins that were below the lower value of reference range at both times. The significant changes (paired t-test) observed in individual groups before and after the feeding trial are related to the growth of pigs.

Conclusion

Diet with acids and tannin did not improve the growth performance of grower pigs but had no deleterious effects on selected blood parameters. The possibility of beneficial effects of adding acids and tannin in diets on growth performance over a longer period, however, could not be excluded.
Mural granulosa cell gene expression associated with oocyte developmental competence
Authors: Jiang Jin-Yi , Xiong Huiling , Cao Mingju , Xia Xuhua , Sirard Marc-Andre , Tsang Benjamin K
Published: March 2010

Background

Ovarian follicle development is a complex process. Paracrine interactions between somatic and germ cells are critical for normal follicular development and oocyte maturation. Studies have suggested that the health and function of the granulosa and cumulus cells may be reflective of the health status of the enclosed oocyte. The objective of the present study is to assess, using an in vivo immature rat model, gene expression profile in granulosa cells, which may be linked to the developmental competence of the oocyte. We hypothesized that expression of specific genes in granulosa cells may be correlated with the developmental competence of the oocyte.

Methods

Immature rats were injected with eCG and 24 h thereafter with anti-eCG antibody to induce follicular atresia or with pre-immune serum to stimulate follicle development. A high percentage (30-50%, normal developmental competence, NDC) of oocytes from eCG/pre-immune serum group developed to term after embryo transfer compared to those from eCG/anti-eCG (0%, poor developmental competence, PDC). Gene expression profiles of mural granulosa cells from the above oocyte-collected follicles were assessed by Affymetrix rat whole genome array.

Results

The result showed that twelve genes were up-regulated, while one gene was down-regulated more than 1.5 folds in the NDC group compared with those in the PDC group. Gene ontology classification showed that the up-regulated genes included lysyl oxidase (Lox) and nerve growth factor receptor associated protein 1 (Ngfrap1), which are important in the regulation of protein-lysine 6-oxidase activity, and in apoptosis induction, respectively. The down-regulated genes included glycoprotein-4-beta galactosyltransferase 2 (Ggbt2), which is involved in the regulation of extracellular matrix organization and biogenesis.

Conclusions

The data in the present study demonstrate a close association between specific gene expression in mural granulosa cells and the developmental competence of oocytes. This finding suggests that the most differentially expressed gene, lysyl oxidase, may be a candidate biomarker of oocyte health and useful for the selection of good quality oocytes for assisted reproduction.
Barriers to initiation of antiretroviral treatment in rural and urban areas of Zambia: a cross‐sectional study of cost, stigma, and perceptions about ART
Authors: Fox Matthew P , Mazimba Arthur , Seidenberg Phil , Crooks Denise , Sikateyo Bornwell , Rosen Sydney
Published: March 2010

Background

While the number of HIV‐positive patients on antiretroviral therapy (ART) in resource‐limited settings has increased dramatically, some patients eligible for treatment do not initiate ART even when it is available to them. Understanding why patients opt out of care, or are unable to opt in, is important to achieving the goal of universal access.

Methods

We conducted a cross‐sectional survey among 400 patients on ART (those who were able to access care) and 400 patients accessing home‐based care (HBC), but who had not initiated ART (either they were not able to, or chose not to, access care) in two rural and two urban sites in Zambia to identify barriers to and facilitators of ART uptake.

Results

HBC patients were 50% more likely to report that it would be very difficult to get to the ART clinic than those on ART (RR: 1.48; 95% CI: 1.21‐1.82). Stigma was common in all areas, with 54% of HBC patients, but only 15% of ART patients, being afraid to go to the clinic (RR: 3.61; 95% CI: 3.12‐4.18). Cost barriers differed by location: urban HBC patients were three times more likely to report needing to pay to travel to the clinic than those on ART (RR: 2.84; 95% CI: 2.02‐3.98) and 10 times more likely to believe they would need to pay a fee at the clinic (RR: 9.50; 95% CI: 2.24‐40.3). In rural areas, HBC subjects were more likely to report needing to pay non‐transport costs to attend the clinic than those on ART (RR: 4.52; 95% CI: 1.91‐10.7). HBC patients were twice as likely as ART patients to report not having enough food to take ART being a concern (27% vs. 13%, RR: 2.03; 95% CI: 1.71‐2.41), regardless of location and gender.

Conclusions

Patients in home‐based care for HIV/AIDS who never initiated ART perceived greater financial and logistical barriers to seeking HIV care and had more negative perceptions about the benefits of the treatment. Future efforts to expand access to antiretroviral care should consider ways to reduce these barriers in order to encourage more of those medically eligible for antiretrovirals to initiate care.
Regulation of Mineralocorticoid Receptor Expression during Neuronal Differentiation of Murine Embryonic Stem Cells
Authors: Munier Mathilde , Meduri Geri , Viengchareun Say , Leclerc Philippe , Le Menuet Damien , Lombès Marc
Published: March 2010

Mineralocorticoid receptor (MR) plays a critical role in brain function. However, the regulatory mechanisms controlling neuronal MR expression that constitutes a key element of the hormonal response are currently unknown. Two alternative P1 and P2 promoters drive human MR gene transcription. To examine promoter activities and their regulation during neuronal differentiation and in mature neurons, we generated stably transfected recombinant murine embryonic stem cell (ES) lines, namely P1-GFP and P2-GFP, in which each promoter drove the expression of the reporter gene green fluorescent protein (GFP). An optimized protocol, using embryoid bodies and retinoic acid, permitted us to obtain a reproducible neuronal differentiation as revealed by the decrease in phosphatase alkaline activity, the concomitant appearance of morphological changes (neurites), and the increase in the expression of neuronal markers (nestin, β-tubulin III, and microtubule-associated protein-2) as demonstrated by immunocytochemistry and quantitative PCR. Using these cell-based models, we showed that MR expression increased by 5-fold during neuronal differentiation, MR being preferentially if not exclusively expressed in mature neurons. Although the P2 promoter was always weaker than the P1 promoter during neuronal differentiation, their activities increased by 7- and 5-fold, respectively, and correlated with MR expression. Finally, although progesterone and dexamethasone were ineffective, aldosterone stimulated both P1 and P2 activity and MR expression, an effect that was abrogated by knockdown of MR by small interfering RNA. In conclusion, we provide evidence for a tight transcriptional control of MR expression during neuronal differentiation. Given the neuroprotective and antiapoptotic role proposed for MR, the neuronal differentiation of ES cell lines opens potential therapeutic perspectives in neurological and psychiatric diseases.
Hypothalamic Kiss1 but Not Kiss2 Neurons Are Involved in Estrogen Feedback in Medaka (Oryzias latipes)
Authors: Mitani Yuta , Kanda Shinji , Akazome Yasuhisa , Zempo Buntaro , Oka Yoshitaka
Published: March 2010

Kiss2, a paralogous gene for kiss1, has recently been identified in several vertebrates. However, their relative potencies for the regulation of reproductive functions appear to differ among species. Here we used medaka as a model animal to examine the kiss1 and kiss2 expression dynamics by in situ hybridization under different conditions: breeding or nonbreeding and ovariectomized or sham operated. Medaka kiss1-expressing neurons and kiss2-expressing neurons were mainly localized in two hypothalamic nuclei, nucleus ventralis tuberis (NVT) and nucleus recessus lateralis (NRL), respectively. NRL kiss2 expression did not change according to differences in breeding condition, whereas NVT kiss1 expression was strongly correlated with breeding condition. In addition, ovariectomy did not change kiss2 expression but significantly decreased the kiss1 expression. Moreover, double-label in situ hybridization revealed that NVT Kiss1 neurons coexpress estrogen receptor-α, whereas NRL Kiss2 neurons do not. From these results, we conclude that the NVT Kiss1 neurons are positively regulated by ovarian estrogen via their coexpressed estrogen receptor-α and are directly involved in the central regulation of reproduction in medaka. In contrast, we argue that the NRL Kiss2 neurons in medaka may serve nonreproductive functions. These functional differences between Kiss1 and Kiss2 neurons are discussed from a phylogenetic viewpoint.
Kisspeptin Cells in the Ewe Brain Respond to Leptin and Communicate with Neuropeptide Y and Proopiomelanocortin Cells
Authors: Backholer Kathryn , Smith Jeremy T. , Rao Alix , Pereira Alda , Iqbal Javed , Ogawa Satoshi , Li Qun , Clarke Iain J.
Published: March 2010

Kisspeptin stimulates reproduction, and kisspeptin cells in the arcuate nucleus (ARC) express Ob-Rb in the mouse. Herein we report studies in ewes to determine whether kisspeptin cells express Ob-Rb and respond to leptin and whether reciprocal connections exist between kisspeptin cells and proopiomelanocortin (POMC) or neuropeptide Y (NPY) cells to modulate reproduction and metabolic function. Kiss1 mRNA was measured by in situ hybridization in ovariectomized ewes that were normal body weight, lean, or lean with leptin treatment by intracerebroventricular (icv) infusion (4 μg/h, 3 d). Kiss1 expression in the ARC and the preoptic area was lower in hypogonadotropic lean animals than animals of normal weight, and icv infusion of leptin partially restored Kiss1 expression in lean animals. Single-cell laser capture microdissection coupled with real-time PCR showed that Kiss1 cells in the preoptic area and ARC express Ob-Rb. Double-label fluorescent immunohistochemistry showed that reciprocal connections exist between kisspeptin cells and NPY and POMC cells. Accordingly, we treated ovariectomized ewes with kisspeptin (5 μg/h, icv) or vehicle for 20 h and examined POMC and NPY gene expression by in situ hybridization. Kisspeptin treatment reduced POMC and increased NPY gene expression. Thus, kisspeptin neurons respond to leptin and expression of Kiss1 mRNA is affected by leptin status. Kisspeptin cells communicate with NPY and POMC cells, altering expression of the relevant genes in the target cells; reciprocal connections also exist. This network between the three cell types could coordinate brain control of reproduction and metabolic homeostatic systems.
Effect of Glucagon-Like Peptide-1 on α- and β-Cell Function in C-Peptide-Negative Type 1 Diabetic Patients
Authors: Kielgast Urd , Asmar Meena , Madsbad Sten , Holst Jens J.
Published: March 2010

Context: The mechanism by which glucagon-like peptide-1 (GLP-1) suppresses glucagon secretion is uncertain, and it is not determined whether endogenous insulin is a necessary factor for this effect.

Objective: To characterize the α- and β-cell responses to GLP-1 in type 1 diabetic patients without residual β-cell function.

Methods: Nine type 1 diabetic patients, classified as C-peptide negative by a glucagon test, were clamped at plasma glucose of 20 mmol/liter for 90 min with arginine infusion at time 45 min and concomitant infusion of GLP-1 (1.2 pmol/kg · min) or saline.

Results: Infusion with GLP-1 increased C-peptide concentration just above the detection limit of 33 pmol/liter in one patient, but C-peptide remained immeasurable in all other patients. In the eight remaining patients, total area under the curve of glucagon was significantly decreased with GLP-1 compared with saline: 485 ± 72 vs. 760 ± 97 pmol/liter · min (P < 0.001). In addition, GLP-1 decreased the arginine-stimulated glucagon release (incremental AUC of 103 ± 21 and 137 ± 16 pmol/liter · min, with GLP-1 and saline, respectively, P < 0.05).

Conclusions: In type 1 diabetic patients without endogenous insulin secretion, GLP-1 decreases the glucagon secretion as well as the arginine-induced glucagon response during hyperglycemia. GLP-1 induced endogenous insulin secretion in one of nine type 1 diabetic patients previously classified as being without endogenous insulin secretion.
Regulation of ERRα Gene Expression by Estrogen Receptor Agonists and Antagonists in SKBR3 Breast Cancer Cells: Differential Molecular Mechanisms Mediated by G Protein-Coupled Receptor GPR30/GPER-1
Authors: Li Yin , Birnbaumer Lutz , Teng Christina T.
Published: March 2010

In selected tissues and cell lines, 17β-estradiol (E2) regulates the expression of estrogen-related receptor α (ERRα), a member of the orphan nuclear receptor family. This effect is thought to be mediated by the estrogen receptor α (ERα). However in the ERα- and ERβ-negative SKBR3 breast cancer cell line, physiological levels of E2 also stimulate ERRα expression. Here, we explored the molecular mechanism that mediates estrogen action in ER-negative breast cancer cells. We observed that E2, the ERα agonist, as well as the ERα antagonists ICI 182,780 and tamoxifen (TAM), a selective ER modulator, stimulate the transcriptional activity of the ERRα gene and increase the production of ERRα protein in SKBR3 cells. Moreover, the ERRα downstream target genes expression and cellular proliferation are also increased. We show further that the G protein-coupled receptor GPR30/GPER-1 (GPER-1) mediates these effects. The GPER-1 specific ligand G-1 mimics the actions of E2, ICI 182,780, and TAM on ERRα expression, and changing the levels of GPER-1 mRNA by overexpression or small interfering RNA knockdown affected the expression of ERRα accordingly. Utilizing inhibitors, we delineate a different downstream pathway for ER agonist and ER antagonist-triggered signaling through GPER-1. We also find differential histone acetylation and transcription factor recruitment at distinct nucleosomes of the ERRα promoter, depending on whether the cells are activated with E2 or with ER antagonists. These findings provide insight into the molecular mechanisms of GPER-1/ERRα-mediated signaling and may be relevant to what happens in breast cancer cells escaping inhibitory control by TAM.
FOXL2 Interacts with Steroidogenic Factor-1 (SF-1) and Represses SF-1-Induced CYP17 Transcription in Granulosa Cells
Authors: Park Mira , Shin Eunkyoung , Won Miae , Kim Jae-Hong , Go Hayoung , Kim Hyun-Lee , Ko Jeong-Jae , Lee Kangseok , Bae Jeehyeon
Published: March 2010

Mutations in FOXL2 are responsible for blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) type I, in which affected women exhibit premature ovarian failure. FOXL2-null mice showed defects in granulosa cell development during folliculogenesis. We screened a rat ovarian yeast two-hybrid cDNA library to identify FOXL2-interacting proteins and found steroidogenic factor-1 (SF-1). Here, we show that human FOXL2 and SF-1 proteins interact in human granulosa cells and that FOXL2 negatively regulates the transcriptional activation of a steroidogenic enzyme, CYP17, by SF-1. Furthermore, FOXL2 mutants found in blepharophimosis-ptosis-epicanthus inversus syndrome type I patients lost the ability to repress CYP17 induction mediated by SF-1. Chromatin immunoprecipitation and EMSA results further revealed that FOXL2 inhibited the binding of SF-1 to the CYP17 promoter, whereas the FOXL2 mutants failed to block this interaction. Therefore, this study identifies a novel regulatory role for FOXL2 on a key steroidogenic enzyme and provides a possible mechanism by which mutations in FOXL2 disrupt normal ovarian follicle development.
Embracing new ideas: an interview with Maria Leptin
Authors: Kain Kristin H.
Published: March 2010

Maria Leptin works simultaneously in the independent fields of immunology and development. She is the new director of the European Molecular Biology Organization (EMBO) and runs a laboratory in Heidelberg, as well as one in Cologne. Here, she describes how she moved between fields and some of the mechanisms that she believes foster creative science.
Highly Porous and Stable Coordination Polymers as Water Sorption Materials
Authors: Akiyama George , Matsuda Ryotaro , Kitagawa Susumu
Published: March 2010

Three MIL-100-type porous coordination polymers were synthesized using different types of anions and their water sorption properties were investigated. All of the compounds adsorbed huge amounts of water (0.6 g g−1) at a moderate humidity (P/P0 < 0.6), and one of the compounds showed the same adsorption property even after two thousand replicate water sorption tests. In addition, the pressure of water adsorption was found to be controlled by counter anions incorporated in the structure, which was attributed to the hydration energy of the anions.
Templateless Synthesis of Nanoporous Gold Sponge with Surface-enhanced Raman Scattering Activity
Authors: Ataee-Esfahani Hamed , Fukata Naoki , Yamauchi Yusuke
Published: March 2010

We demonstrate templateless synthesis of nanoporous gold (Au) sponge by chemical reduction of Au species in aqueous solution. The obtained Au nanosponges exhibit surface-enhanced Raman scattering activity.
Behaviour of 4-(−2-Hydroxyethyl)-1-Piperazineethanesulphonic Acid under Electrospray Ionisation Mass Spectrometry Conditions
Authors: Saraiva Marco A. , Borges Carlos M. , Florêncio M. Helena
Published: March 2010

Our previous experiments on electrospray ionisation mass spectrometry (ESI-MS) analysis of reaction mixture solutions containing 4-(−2-hydroxyethyl)-1-piperazineethanesulphonic acid (HEPES), a commonly used buffer, indicated that HEPES species did not significantly suppress analyte species, even in reaction mixture solutions with significant amounts of HEPES. With the purpose of investigating the behaviour of HEPES under ESI-MS conditions, HEPES aqueous solutions and HEPES aqueous solutions containing analyte with high- and low polarity and with different acid/base chemistry, were therefore investigated. For electrosprayed aqueous solutions of HEPES with concentrations above 10−5 M, an enhanced formation of HEPES multimer ions, showing HEPES monomer ion formation, was observed. This enhanced formation of HEPES multimer ions is much higher than those observed for other polar compounds, such as acetyl–arginine, acetyl–lysine and histidine. Information from solution behaviour such as HEPES concentration, solution pH and instrumental factors, namely the capillary temperature, was related to information from mass spectra. The results obtained led us to conclude that the formation of HEPES ions is related to the initial solution composition. The influence of analyte species on HEPES species formation, for electrosprayed HEPES solutions with analyte, was also investigated. The variations observed for HEPES monomer and multimer ion abundances, which were found to be consistent with those observed for analyte monomer ion abundances, were related to the type of analyte, i.e. to their acid/base nature. Strikingly, the variations observed between HEPES monomer and multimer ion abundances enable the discrimination of different influences of analyte species on HEPES species formation. The results obtained also provided an explanation for the observation that HEPES species do not significantly suppress analyte species ion signals when highly-concentrated HEPES solutions with analyte are electrosprayed. According to our results, the associated behaviour between HEPES species seems to be preserved in the gas phase during electrospray ionisation. This observation may provide some information that may be useful regarding the behaviour involved in the gas-phase ion formation process from charged droplets during electrospray ionization or, at least, to differentiate between behaviours.
Differentiation of Four Pairs of Furocoumarin Isomers by Electrospray Ionization Tandem Mass Spectrometry
Authors: Liu Guo-Qang , Dong Jing , Wang Hong , Hashi Yuki , Chen Shi-Zhong
Published: March 2010

A mass spectrometric method based on the combined use of electrospray ionization, collision-induced dissociation (CID) and ion-trap time-of-flight (IT-ToF) tandem mass spectrometry was used to identify four pairs of furocoumarin isomers. Our results show some characteristic mass spectrometric differences in isomeric furocoumarins. In the MS2 spectra, the relative abundance ratios of m/z 131 [M + H – 2CO]+ to m/z 143 [M + H – CO2]+ and m/z 115 [M + H – CO–CO2]+ of psoralen are less than one, but both ratios are greater than one in the case of isopsoralen. The relative abundance of m/z 159 [M + H – CO2]+ is much higher than that of m/z 175 [M + H – CO]+ in the case of bergaptol, but this trend is reversed in xanthotoxol. Moreover, three diagnostic ions of m/z 189 [M + H – CO]+, m/z 185 [M + H – CH4O]+ and m/z 161 [M + H – 2CO]+ are observed in the MS2 spectrum of xanthotoxin but not in that of bergapten. Further, two diagnostic ions of m/z 226 [M-H-CH3-CO]− and m/z 210 [M – H – CH3 – CO2]− are observed in the MS2 spectrum of isoimperatorin but not in that of imperatorin. The relative abundance of product ions associated with some diagnostic ions can be used to characterize furocoumarin isomers.
Sequencing Two Cooperating Automated Stacking Cranes in a Container Terminal
Authors: Vis Iris F. A. , Carlo Hector J.
Published: March 2010

The containerized trade market is growing rapidly with the uprising of the Far East. Container ports worldwide should be responsive by developing tools to handle these massive volumes of containers in order to retain their level of competitiveness. One of the areas in a container terminal that is highly affected by the increase in the demand of containers is the stack. The stack is used to temporarily store containers upon further transport to their destination. This study is concerned with scheduling sea and landside storages and retrievals in a stack with two cooperating automated stacking cranes working in a single block. We present a mathematical model to minimize the makespan for both cranes. Both an algorithm to derive a lower bound for the makespan and a simulated-annealing based heuristic are proposed to efficiently solve the problem. Numerical experiments show that the solutions of the heuristic method are within 2% of the lower bound for large instances.
An Efficient Greedy Heuristic for Warehouse-Retailer Network Design Optimization
Authors: Shu Jia
Published: March 2010

In this paper, we study a warehouse-retailer network design (WRND) model that simultaneously makes the location, distribution, and warehouse-retailer echelon inventory replenishment decisions. Although a column generation algorithm was proposed recently in the literature, it remains a challenge to solve large size instances of this NP-hard problem efficiently and effectively. The purpose of this paper is to present a greedy algorithm. Computational results demonstrate that our greedy algorithm can solve large-scale WRND problems efficiently with errors within 3%–4% on average.
The Stochastic Multiperiod Location Transportation Problem
Authors: Klibi Walid , Lasalle Francis , Martel Alain , Ichoua Soumia
Published: March 2010

This paper studies a stochastic multiperiod location-transportation problem (SMLTP) characterized by multiple transportation options, multiple demand periods, and a stochastic demand. We consider the determination of the number and location of the depots required to satisfy customer demand as well as the mission of these depots in terms of the subset of customers they must supply. The problem is formulated as a stochastic program with recourse, and a hierarchical heuristic solution approach is proposed. It incorporates a tabu search procedure, an approximate route length formula, and a modified procedure of Clarke and Wright (Clarke, G., J. W. Wright. 1964. Scheduling of vehicles from a central depot to a number of delivery points. Oper. Res. 12 568–581). Three neighbourhood exploration strategies are proposed and compared with extensive experiments based on realistic problems.
Tactical and Operational Planning of Scheduled Maintenance for Per-Seat, On-Demand Air Transportation
Authors: Keysan Gizem , Nemhauser George L. , Savelsbergh Martin W. P.
Published: March 2010

Advances in aviation technology including the development of relatively cheap, very light jets and the possibility of free-flight have led to the realization of a per-seat, on-demand air transportation business that operates without a published flight schedule. One of the decision problems this business faces is planning the scheduled maintenance that has to be done periodically for safety reasons. Careful planning of scheduled maintenance in this dynamic business environment is required to ensure safe and efficient operations.

In this paper, we address both tactical and operational planning for scheduled maintenance of per-seat, on-demand air transportation. At the tactical level, we determine the daily maintenance capacities. As the fleet size grows over time, decisions pertaining to when and how much to increase maintenance capacity are made. At the operational level, we assign itineraries to jets and determine the jets to be maintained on a daily basis. We further embed operational maintenance planning into a framework that captures the interaction between maintenance decisions and daily flight scheduling.
Congestion Pricing for Schedule-Based Transit Networks
Authors: Hamdouch Younes , Lawphongpanich Siriphong
Published: March 2010

In this paper, we develop models for adjusting or setting fares on a transit system to encourage passengers to choose travel strategies that lead to the least travel delay for the entire system. In our problem setting, these fares vary with time of day.

Similar to the one used to reduce congestion on vehicular traffic networks, our goal is to adjust or set fares so that a user equilibrium solution under the new fares yields the least delay or is system optimal. On the other hand, pricing frameworks for traffic networks such as marginal cost pricing do not readily apply because the travel delay in transit systems involves factors different from those in vehicular traffic and cannot be expressed in closed functional forms. The models herein are schedule based and account for loading priorities and individual vehicle capacities explicitly. Differences among the proposed models are illustrated with a small network.
Match making and match breaking: The nature of match within and around job design
Authors: Daniels Kevin , De Jonge Jan
Published: March 2010

We explore the notion of ‘match’. In the context of job design, this is congruence or correspondence between two or more job characteristics (e.g. cognitive demands and cognitive control). This congruence is thought to benefit health, well‐being, and performance. The origins of the match concept lie in buffering models of work stress, where resources such as workplace social support and job control are thought to attenuate deleterious effects of adverse job characteristics like excessive job demands. We outline the historical developments in work stress research that has led to notions of match, contrast match with the related concept of person‐environment fit, explore current conceptualizations and operationalizations of match, and outline how the concept of match can be developed.
Contamination of the Norepinephrine Prodrug Droxidopa by Dihydroxyphenylacetaldehyde
Authors: Holmes Courtney , Whittaker Noel , Heredia-Moya Jorge , Goldstein David S
Published: March 2010

Background: l-Threo-3,4-dihydroxyphenylserine (L-DOPS, droxidopa) is a norepinephrine (NE) prodrug under development to treat orthostatic hypotension. 3,4-Dihydroxyphenylacetaldehyde (DOPAL), an endogenous catecholaldehyde produced by enzymatic oxidative deamination of dopamine, is toxic to catecholaminergic neurons. Based on the observation of increasing plasma DOPAL after oral administration of L-DOPS to a patient, we examined whether other subjects also had DOPAL in their plasma after droxidopa administration, and whether droxidopa is contaminated with DOPAL.

Methods: Thirteen subjects took 400 mg droxidopa orally. We sampled venous blood at baseline and 1, 2, 3, 6, 24, and 48 h after drug administration and assayed L-DOPS, NE, and DOPAL by use of liquid chromatography with electrochemical detection (LC-ED). Droxidopa in acidic solution (20:80 mixture of 0.04 mol/L phosphoric acid:0.20 mol/L acetic acid) was vacuum centrifuged for 1 h at 30 °C and then assayed by LC-ED.

Results: Droxidopa contained 0.01% DOPAL. At 6 h after droxidopa, all subjects had detectable DOPAL in plasma (1.89 nmol/L, P = 0.0001). Across the sampling times, plasma DOPAL correlated with plasma L-DOPS (r = 0.996). The mean increment in plasma DOPAL was more than 4 times that in plasma NE (0.39 nmol/L). In 2 patients with Parkinson disease and orthostatic hypotension, DOPAL was detected in plasma at baseline (0.12 nmol/L) and increased by about 70-fold after droxidopa. Vacuum concentration of droxidopa in the acid solution converted L-DOPS to DOPAL completely.

Conclusions: Droxidopa is contaminated with DOPAL. After oral droxidopa administration, DOPAL is detected in plasma of humans. Droxidopa is susceptible to extensive nonenzymatic conversion to DOPAL.
Deriving Value from Social Commerce Networks
Authors: Stephen Andrew T. , Toubia Olivier
Published: March 2010

Social commerce is an emerging trend in which sellers are connected in online social networks and sellers are individuals instead of firms. This article examines the economic value implications of a social network between sellers in a large online social commerce marketplace. In this marketplace, each seller creates his or her own shop, and network ties between sellers are directed hyperlinks between their shops. Three questions are addressed: (1) Does allowing sellers to connect to each other create value (i.e., increase sales)? (2) What are the mechanisms through which this value is created? and (3) How is this value distributed across sellers in the network and how does the position of a seller in the network (e.g., its centrality) influence how much he or she benefits or suffers from the network? The authors find that (1) allowing sellers to connect generates considerable economic value, (2) the network's value lies primarily in making shops more accessible to customers browsing the marketplace (the network creates a “virtual shopping mall”), and (3) the sellers who benefit the most from the network are not necessarily those who are central to the network but rather those whose accessibility is most enhanced by the network.
How Sales Taxes Affect Customer and Firm Behavior: The Role of Search on the Internet
Authors: Anderson Eric T. , Fong Nathan M. , Simester Duncan I. , Tucker Catherine E.
Published: March 2010

When a multichannel retailer opens its first retail store in a state, the firm is obligated to collect sales taxes on all Internet and catalog orders shipped to that state. This article assesses how opening a store affects Internet and catalog demand. The authors analyze purchase behavior among customers who live far from the retail store but must now pay sales taxes on catalog and Internet purchases. A comparable group of customers in a neighboring state serves as a control. The results show that Internet sales decrease significantly, but catalog sales are unaffected. Further investigation indicates that the difference in these outcomes is partly attributable to the ease with which customers can search for lower prices at competing retailers. The authors extend the analysis to a panel of multichannel firms and show that retailers that earn a large proportion of their revenue from direct channels avoid opening a first store in high-tax states. They conclude that current U.S. sales taxes laws have significant effects on both customer and firm behavior.
Emotional Compatibility and the Effectiveness of Antidrinking Messages: A Defensive Processing Perspective on Shame and Guilt
Authors: Agrawal Nidhi , Duhachek Adam
Published: March 2010

Five studies examine how the two distinct emotional states of shame and guilt influence the effectiveness of messages that highlight socially undesirable consequences of alcohol consumption. Appeals that frame others as observing versus suffering the negative consequences of binge drinking differentially activate shame and guilt. Given these emotional consequences of message framing, the authors examine the interaction between incidental shame or guilt and message framing on drinking intentions and behavior. Compatible appeals (i.e., appeals that elicit the same emotion as being incidentally experienced by the consumer) are less effective in influencing behavioral intentions and beverage consumption because of a process in which consumers discount the notion that they may cause the negative consequences outlined in the message. Such defensive processing of compatible messages is driven by a desire to reduce the existing negative emotion.
The Effect of Experiential Analogies on Consumer Perceptions and Attitudes
Authors: Goode Miranda R. , Dahl Darren W. , Moreau C. Page
Published: March 2010

Consumers desire products that provide meaningful experiences. Therefore, a marketer's success often depends on familiarizing consumers with the unique experience a product offers. Marketers recognize the value in communicating about a product experience through analogy, but little research has investigated if and why these analogies are persuasive. By comparing a product to a familiar but disparate experience, an analogy has the power to focus consumers on the evaluative, emotional, and multisensory information associated with the product experience. This focus on subjective product experience enables the identification of base preference (i.e., a consumer's liking for the comparison experience) as an important moderator of analogical persuasiveness. In addition, the emotional knowledge transfer perspective applied in this research contributes to a better understanding of the role of emotional knowledge and experienced emotion in analogical thinking.
Consumer Value-Maximizing Sweepstakes and Contests
Authors: Kalra Ajay , Shi Mengze
Published: March 2010

Sweepstakes and contests are some of the most frequently used promotional tools. Consumers participating in sweepstakes or contests have an opportunity to win prizes through a random draw. The authors examine how commonly used sweepstakes formats that vary in the number of winners and the allocation of the total reward money among the winners affect consumer valuations of the promotion. Given a fixed amount of reward money, the authors examine alternative reward formats based on the promotional objectives, consumer risk aversion, and degree of subadditivity. They test the analytical results using an experimental approach.
The Effects of Consumer Prior Knowledge and Processing Strategies on Judgments
Authors: Hong Jiewen , Sternthal Brian
Published: March 2010

Four studies examine how consumers’ prior knowledge of a product category and the way they process product information affect evaluation. Consumers with extensive prior knowledge of a category evaluate the brand more favorably when the presentation of the product information prompts a sense of progress rather than facilitating a detailed assessment (Studies 1 and 2), as well as when the information presentation involves a high level of construal rather than a low level (Studies 3 and 4). Consumers with limited domain knowledge exhibit opposite outcomes. The subjective experience of processing fluency mediates these effects. The findings suggest that evaluations are more favorable when there is a fit between prior knowledge and message processing than when fit is absent.
Buffering and Amplifying Effects of Relationship Commitment in Business-to-Business Relationships
Authors: Ganesan Shankar , Brown Steven P. , Mariadoss Babu John , Ho Hillbun (Dixon)
Published: March 2010

Using an assimilation and contrast framework, the authors assess the buffering and amplifying effects of relationship commitment on organizational buyers’ intentions to switch suppliers when a relationship is strained by the incumbent's own misbehavior. The results of three studies show that both calculative and affective commitment buffer incumbent suppliers against minor incidences of their own misbehavior but that affective commitment also reliably amplifies the adverse effects of an incumbent supplier's flagrant opportunism. Process tests indicate that buyer perceptions of supplier conformance to normative standards account for (completely mediate) the observed buffering and amplification effects in a manner consistent with the underlying assimilation and contrast framework.
Cognitive Inertia and the Implicit Association Test
Authors: Messner Claude , Vosgerau Joachim
Published: March 2010

The authors review the implicit association test (IAT), its use in marketing, and the methodology and validity issues that surround it. They focus on a validity problem that has not been investigated previously, namely, the impact of cognitive inertia on IAT effects. Cognitive inertia refers to the difficulty in switching from one categorization rule to another, which causes IAT effects to depend on the order of administration of the two IAT blocks. In Study 1, the authors observe an IAT effect when the compatible block precedes the incompatible block but not when it follows the incompatible block. In Studies 2 and 3, the IAT effect changes its sign when the order of the blocks reverses. Cognitive inertia distorts individual IAT scores and diminishes the correlations between IAT scores and predictor variables when the block order is counterbalanced between subjects. Study 4 shows that counterbalancing the block order repeatedly within subjects can eliminate cognitive inertia effects on the individual level. The authors conclude that researchers should either interpret IAT scores at the aggregate level or, if individual IAT scores are of interest, counterbalance the block order repeatedly within subjects.
Remembering the SIEV X: Who Cares for the Bodies of the Stateless, Lost at Sea?
Authors: Gibbings Beth
Published: March 2010

The SIEV X was a tiny fishing vessel traveling from Indonesia to Australia in 2001, carrying around four hundred people seeking asylum after fleeing from the warfare and persecution predominantly in Iraq and Afghanistan. Many were women and children trying to enter Australia to join fathers and husbands already granted refugee status but not allowed to bring in family members because of new Australian laws on “Temporary Protection Visas.” Of these, 353 drowned when the boat sank in international waters. The conservative Australian government denied responsibility, using the event in an election campaign to play on fears about illegal entry and border defense in the Islamophobic climate in the aftermath of 9/11. Yet many everyday Australians eventually became involved in a collaborative design process to create a memorial to those asylum seekers. This article discusses the debates around memorials for those lost at sea, and particularly for those who might be portrayed as enemies or “illegal immigrants” whose coming threatens national borders. It identifies the conditions under which the campaign to commemorate those who died on the SIEV X moved from being a minority interest to become a cause so widely supported by Australians across the country that the memorial was eventually erected in the heart of the national capital.
From State Terrorism to State Errorism: Post-Pinochet Chile's Long Search for Truth and Justice
Authors: Wyndham Marivic , Read Peter
Published: March 2010

Patio 29 lies in the northern sector of Santiago's General Cemetery. To the naked eye, it is a grim unweeded field of some twelve hundred rusted tin crosses. But to the families of the 1,197 detained-disappeared during Augusto Pinochet's brutal dictator-ship, Patio 29 is both a site of horror and a site of hope. Its story begins in September-December 1973 when 320 early victims of the repression were brought there in makeshift wooden crates that held as many as three bodies each, and buried in unmarked graves. A few years later, two hundred of those graves were exhumed by the military, and the remains presumably cremated. For another decade, the mass grave remained silent, yielding few of its secrets to the families' demands to know: Where are they? Today, nineteen years into the so-called transition to democracy, Patio 29—the most important single finding in relation to Chile's detained-disappeared—still refuses to reveal the identities of those victims, pressing upon the government of Michelle Bachelet a new question: Who are they? First state terror, now state error have conspired to make Patio 29 one of Chile's principal horror-cum-hopescapes.
Introduction
Authors: Keene Judith
Published: March 2010

This special issue of The Public Historian will examine what is a pressing, pervasive, traumatic, and very public contemporary issue in which history and historians are heavily involved in many countries around the globe. Authors will investigate a range of issues around the state involvement in death, including the role of the state as perpetrator and its responsibilities to the victims and their families; the process and significance of exhumation, of identification, and of repatriation; the status of refugees and displaced peoples who die when legally stateless and so without state protection; the differing transnational stances in tracing and punishing the perpetrators; the fraught issue of personal and official reparation; and the role and efficacy of international justice.
Where are the Bodies? In the Ground
Authors: Wright Richard
Published: March 2010

The subject of this essay is the judicial context of bodies from mass graves. I shall discuss topics that exemplify the power that flows from being able to display bodies to courts. By contrast, and where there are no bodies to show, a lazy prosecution case can be weakened by the unnecessary lack of material evidence. Particularly vulnerable are cases that depend on the statements of eye-witnesses. I shall discuss efforts by revisionists to protect their positions. These efforts include denying that there are any bodies as well as claims that the number of bodies is less than expected and that the bodies are attributable to unrelated events. These discussions will be illustrated with critical evidentiary photos.