bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Mechanisms with Martingale Utilities
Authors: Balseiro Santiago R. , Mirrokni Vahab S. , Leme Renato Paes 
Published: December 2017

We study the dynamic mechanism design problem of a seller who repeatedly sells independent items to a buyer with private values. In this setting, the seller could potentially extract the entire buyer surplus by running efficient auctions and charging an upfront participation fee at the beginning of the horizon. In some markets, such as Internet advertising, participation fees are not practical since buyers expect to inspect items before purchasing them. This motivates us to study the design of dynamic mechanisms under successively more stringent requirements that capture the implicit business constraints of these markets. We first consider a periodic individual rationality constraint, which limits the mechanism to charge at most the buyer’s value in each period. While this prevents large upfront participation fees, the seller can still design mechanisms that spread a participation fee across multiple initial auctions. These mechanisms have the unappealing feature that they provide close-to-zero buyer utility in earlier auctions in exchange for higher utility in later auctions. To address this problem, we introduce a martingale utility constraint, which imposes the requirement that from the perspective of the buyer, the next item’s expected utility is equal to the present one’s. Our main result is providing a dynamic auction satisfying martingale utility and periodic individual rationality whose loss in profit with respect to first-best (full extraction of buyer surplus) is optimal up to polylogarithmic factors. The proposed mechanism is a dynamic two-tier auction with a hard floor and a soft floor that allocates the item whenever the buyer’s bid is above the hard floor and charges the minimum of the bid and the soft floor. The electronic companion is available at https://doi.org/10.1287/mnsc.2017.2872 . This paper was accepted by Noah Gans, stochastic models and simulation.
Supply Chain Contracting in Environments with Volatile Input Prices and Frictions
Authors: Kouvelis Panos , Turcic Danko , Zhao Wenhui 
Published: December 2017

Problem description: Purchase costs of raw materials required in production tend to fluctuate over time. Mild cost fluctuations merely affect firms’ profitability. Significant variations can lead to supply chain disruption. What are the best contracts to be used in supply chains exposed to fluctuating raw material costs? We ask this question in two contexts—in the presence and the absence of working capital constraint. Academic/practical relevance: We add a framework on how to optimally contract in the presence of stochastic costs and working capital constraints and help managers understand how they can increase profitability. Methodology: We present a game-theoretic study of a bilateral monopoly supply chain with stochastic demand, stochastic input costs, production lead times, and working capital constraints. The upstream firm announces a supply contract to which the downstream firm responds with an order quantity. The contract is a single-price, multi-instrument contract with optional default penalties. Many previously studied coordinating contracts, as well as some noncoordinating ones, are special cases of our general contract. Results: We derive necessary and sufficient conditions that the instruments of the general contract must satisfy for the contract to induce a coordinated outcome—both with and without working capital constraints. Then we translate these requirements into implementable contracts. Indexing (I) on raw material prices and using default penalties (Ps) is necessary, and an I&P revenue-sharing contract turns out to be the most versatile contract for these environments. Managerial implications: We provide clear guidelines on how to contract in situations where production costs of every supply chain member fluctuate significantly, possibly in the presence of working capital constraints. The online appendix is available at https://doi.org/10.1287/msom.2017.0660 . This paper has been accepted for the Manufacturing & Service Operations Management Special Issue on Interface of Finance, Operations, and Risk Management.
A Link-Based Differential Complementarity System Formulation for Continuous-Time Dynamic User Equilibria with Queue Spillbacks
Authors: Ma Rui , Ban Xuegang (Jeff) , Pang Jong-Shi 
Published: December 2017

This paper proposes a link-based continuous-time dynamic user equilibrium model for networks with single destinations. The model captures realistic queue spillbacks by applying the double-queue concept at the link level and developing a new nodal model that extends the link-level dynamics to the network level. The departure-time choice, route choice, and other equilibrium conditions are introduced to complete the model. The proposed model is a differential complementary system formulation with time-varying, state-dependent delays. Approximations on travel times are constructed to simplify the model. Numerical tests are developed to illustrate the application of this model. The online appendix is available at https://doi.org/10.1287/trsc.2017.0752 .
Patient and staff awareness of ophthalmic treatment costs
Authors: Negretti Guy , Kang Swan , Basheer Khadijah , Duggineni Sirisha , Kam Ronald , Verma Seema 
Published: December 2017

Aim: The aim of this study was to explore the knowledge of patients and staff in relation to the costs of selected ophthalmic interventions. Methods: A questionnaire was designed with the help of the Patient-Public Involvement Committee at Moorfields Eye Hospital. It was subsequently distributed to all patients attending the ophthalmic accident and emergency department and selected outpatient clinics over a two-week period. The questionnaire asked participants to estimate the costs of nine treatments or investigations and supplementary questions were also asked in relation to costs. Results: Participants comprised of 436 patients (210 males, 219 females, 7 did not self-identify) and 71 staff (32 males, 39 females) who returned completed questionnaires. Staff gave an estimated cost that was not statistically different from the actual cost for four out of the nine treatments. The mean values for the patients' answers were all significantly different from the actual costs. Both patients and staff had a tendency to over estimate the costs of treatments. Some participants had not considered how much these procedures cost the NHS to provide (36% of patients and 21% of staff respectively). Conclusions: Unsurprisingly, staff are more knowledgeable than patients of the costs of treatments they provide. Despite this, there were still multiple treatments which staff were not able to estimate the costs of accurately (5 out of 9). In this study, accurately was defined as no significant difference from the actual value. If the participant group who have never considered how much it costs the NHS to provide their care could be targeted with an educational program on costs of healthcare this may lead to better use of healthcare resources in the future.
Uczeń zdolny a udział w olimpiadzie językowej
Authors: Spychała-Wawrzyniak Małgorzata 
Published: December 2017

Out of all foreign languages in Polish schools Spanish has achieved the most dynamic increase in popularity within the last few years. For those most fascinated with Spanish and its culture, there have been six editions of the National Spanish Contest in Poland, organised by the Modern Language Association of Poland in cooperation with Adam Mickiewicz University’s Institute of Romance Studies. The aim of the article is to present the assumptions and activities of the contest, targeted at the most gifted students, as well as to examine the ways in which the best ones among them prepared themselves, including the amount of time they spent analysing the program guidelines. We will try to address the question whether contest finalists are truly gifted students or merely ones with high language aptitude. Special focus will be placed on finalists’ work with their teachers. We are also going to consider possible challenges and problems, which they faced during the preparation process.
Nuda a praktyczna nauka języka angielskiego
Authors: Kruk Mariusz , Zawodniak Joanna 
Published: December 2017

Although boredom is among the most common academic emotions experienced by students at all possible levels of education, so far it has not received due attention from SLA theorists and researchers. Accordingly, the present paper aims to discuss the concept of boredom from the L2 classroom perspective with a special regard to the university students of English Philology. In the first part the authors provide a definition, present two basic typologies and highlight the causes of boredom followed by a brief overview of research into boredom in educational settings, whereas the second part is intended to approach a phenomenon of boredom on an empirical basis. The authors report on both quantitative and qualitative research findings concerning the intensity of boredom as felt by the subjects during the practical English language classes. First, the numerical results obtained from the Boredom Proneness Scale and correlated to boredom experienced in practical English language classes are referred to. Then the qualitative data gathered from the students’ descriptions of boredom-related situations during the said classes are commented on. Finally, the authors proceed to propose certain L2 classroom boredom-coping options.
A Unifying Motif for Spatial and Directional Surround Suppression
Authors: Liu Liu D. , Miller Kenneth D. , Pack Christopher C. 
Published: December 2017

In the visual system, the response to a stimulus in a neuron's receptive field can be modulated by stimulus context, and the strength of these contextual influences vary with stimulus intensity. Recent work has shown how a theoretical model, the stabilized supralinear network (SSN), can account for such modulatory influences, using a small set of computational mechanisms. Although the predictions of the SSN have been confirmed in primary visual cortex (V1), its computational principles apply with equal validity to any cortical structure. We have therefore tested the generality of the SSN by examining modulatory influences in the middle temporal area (MT) of the macaque visual cortex, using electrophysiological recordings and pharmacological manipulations. We developed a novel stimulus that can be adjusted parametrically to be larger or smaller in the space of all possible motion directions. We found, as predicted by the SSN, that MT neurons integrate across motion directions for low-contrast stimuli, but that they exhibit suppression by the same stimuli when they are high in contrast. These results are analogous to those found in visual cortex when stimulus size is varied in the space domain. We further tested the mechanisms of inhibition using pharmacological manipulations of inhibitory efficacy. As predicted by the SSN, local manipulation of inhibitory strength altered firing rates, but did not change the strength of surround suppression. These results are consistent with the idea that the SSN can account for modulatory influences along different stimulus dimensions and in different cortical areas.SIGNIFICANCE STATEMENTVisual neurons are selective for specific stimulus features in a region of visual space known as the receptive field, but can be modulated by stimuli outside of the receptive field. The SSN model has been proposed to account for these and other modulatory influences, and tested in V1. As this model is not specific to any particular stimulus feature or brain region, we wondered whether similar modulatory influences might be observed for other stimulus dimensions and other regions. We tested for specific patterns of modulatory influences in the domain of motion direction, using electrophysiological recordings from MT. Our data confirm the predictions of the SSN in MT, suggesting that the SSN computations might be a generic feature of sensory cortex.
FAKTOR-FAKTOR YANG MEMPENGARUHI EFEKTIVITAS PENCEGAHAN PENULARAN HIV DARI IBU KE ANAK (PPIA) DI KOTA JAYAPURA
Authors: Tumangke Hesty , Tappy Melkior , Kendek Rispan 
Published: December 2017

Abstrak
Provinsi Papua memiliki prevalensi HIV/AIDS tinggi, dimana terdapat 6957 wanita usia 15-49 tahun menderita HIV/AIDS. Masalah ini dapat menyebabkan penularan HIV/AIDS ke bayi bahkan kematian bayi karena HIV. Penelitian ini bertujuan menganalisa faktor yang mempengaruhi keberlangsungan program PPIA.
Penelitian menggunakan metode kualitatif dengan pengumpulan data melalui wawancara mendalam. Penelitian dilakukan di Jayapura, Dinas Kesehatan Kota Jayapura dari Januari 2015 sampai Juni 2015. Populasi penelitian adalah semua tenaga kesehatan di dinas kesehatan kota Jayapura, dan sampel nya adalah 12 orang mencakup kepala UPT AIDS TB, kepala seksi P2PL, kepala puksesmas, kepala KIA, staf KIA dan penanggung jawab HIV puskesmas. Pengambilan sampel adalah purposif sampling dan data dianalisis dengan triangulasi.
PPIA tidak berhasil karena rendah nya K1 dan juga K4, dimana ada puskesmas yang memiliki K4 hanya 58%. Di rumah sakit Abepura ditemukan 8 kelahiran bayi dengan HIV, hal ini karena ibu hamil positif yang tidak menkonsumsi ARV secara rutin sampai melahirkan. Rendah nya K1 juga disebabkan oleh beberapa faktor yaitu ibu hamil lebih tertarik ke dokter praktek, suami yang tidak setuju bila istri nya mendapatkan tes VCT, dan rendah nya kesadaran ibu hamil akan pentingnya K1 sampai K4 dan juga VCT. Begitu juga dengan SIHA yang tidak berjalan dengan baik.
Kata kunci : Pencegahan HIV, Ibu hamil, bayi, Jayapura

Papua province has high prevalence of HIV/AIDS where there was 6957 cases among women age 15-49 years old. Moreover, this increasedthe number of infants with HIV and impact the rise of infant mortality rate.This study aims to analize factors that affected this HIV prevention from mother to child.
This study is qualitative using indeep interview, and located in Jayapura City from January 2015 to June 2015. The population is all staffs in Jayapura’s Health Department, and the total sample is 12 including head of this program, staff of local primary care, staf of hospital, and staffs that have responsibily to run this program. This is purposive sampling, and data will analize with triangulation.
HIV prevention is not success due to the low rate of pregnant women visit to local primary care. There was a local primary care that only has 58% of pregnant women visit. In Abepura hospital 2015, there was 8 cases of childborn with HIV. This is because many positive mothers did not consum ARV. The low visit in local primary care has several causes such as mother more willing to go to private obsetric, treat from husband where husband didn’t allow VCT to his wive, and the low self efficacy of pregnant mother. The HIV report system is not well implemented.
Key words : HIV Prevention, pregnant mother, infant, Jayapura
Prevalencia de mastitis subclínica, microorganismos asociados y factores de riesgo identificados en hatos de la provincia de Pamplona, Norte de Santander
Authors: Mendoza Jesús Alberto , Vera Yanedt , Peña Luis Carlos 
Published: December 2017

Mastitis prevalence, associated microorganisms and related risk factors were determined in dairy operations from municipalities belonging to the province of Pamplona (Norte de Santander). California Mastitis Test (CMT) was performed in 1208 quarters from 302 animals located in 108 rural properties. Milk samples from positive quarters (trace up to 3+) were obtained and submitted for microbiological isolation. Analysis of a 64 variables survey related to the milking practices in the rural properties under study and its link with the presence of the disease was performed using contingency charts and chi-square test (χ2). Determined prevalence per individual was 54,6% (165/302) (95% CI 48.8 to 60.3) CMT positive animals. In 67,6% (73/108) (95% CI 58.3 to 75.7) of the rural properties the presence of at least one animal testing positive was detected, whereas a total of 21,6% quarters (260/1208) (95% CI 19.3 to 23.9) showed CMT reactivity. From the samples subjected to isolation and microbiological characterization, a total of 74.4% were compatible with Staphylococcus aureus, 12.3% with Streptococcus agalactiae and 13.3% with coliforms. A total of 17 characteristics were associated with the presence of mastitis, all of which were related to poor milking practices. The presence of contagious mastitis associated microorganisms, shows the need for training and orientation to implement proper milking practices and enhance the competitiveness of this sector in the region, which will result in an increase in production.
Valoración de energía digestible de la glicerina cruda proveniente de aceite de palma -<i>Elaeis guineensis</i>- para cerdos en crecimiento en función del nivel de almidón de maíz en la dieta
Authors: Ordoñez-Gomez Ciro Alberto , Mejia Gonzalo , Afanador-Tellez German , Ariza-Nieto Claudia 
Published: December 2017

To determine the apparent digestible energy (EDA) of crude glycerin (GC) from palm oil (Elaeis guineensis) in pigs two experiments (E) were performed. In E1, EDA was determined to GC, with the technique of mobile nylon bag (TBMN) using eight barrows with duodenal cannula. In E2, EDA, EMA to GC was determined by the conventional method with indicator (MCI) with 10 barrows placed in metabolic cages. In E1 and E2 were evaluated in 2 x 5 factorial arrangement, two levels of corn starch (NA) in the diet, 10 (NA10) and 12% (NA12), and five levels of replacement by GC, 0; 2.5; 5; 7.5 and 10%, in E1 as a completely randomized design and in E2 as a Latin square design. For MCI and TBMN, data were analyzed using multiple linear regression and nitrogen metabolism in MCI as a Latin square design using the GLM and REG modules of SAS. By TBMN there was no effect (P> 0.05) in the NA on the EDA of GC. EDA of GC was calculated at 3251 kcal / kg DM. EDA of GC in the MCI depended NA (P <0.001), estimated at 4427.3 and 3769.3 Kcal / kg MS for NA10 and NA12, respectively. Interaction (P <0.001) between NA and GC for the amount of digestible nitrogen was observed, was reduced when GC increased by NA12 and increased by NA10. Other nitrogen metabolism parameters were not affected (P> 0.05). The results of EDA corrected by NA with MCI showed high correlation (R2 = 0.82) with TBMN. By MCI was established that increased in NA reduced the EDA of GC.
Catch up growth and social capability in developing countries: A conceptual and measurement proposal
Authors: Andersson Martin , Palacio Andrés 
Published: December 2017

While the income per capita in the developing world since the turn of the Millennium has grown faster than that of the developed world, the question whether there is an ongoing process of catching up between countries remains. The notion of income convergence has provided many insights into the sources for long-run growth but has largely neglected the role of social capabilities in economic development. By social capabilities we mean the qualification of the ‘theory of convergence’ which asserts that productivity growth rates between countries tend to vary inversely with regard to productivity levels. The social capabilities approach holds that a country’s potential for rapid growth is strong when “it is technologically backward but socially advanced” (see Abramovitz, 1986:388). This means that the potential to catch up under globalization is strongest for countries in which social capabilities are developed to allow successful use of technologies and where institutional arrangements are conducive to economic progress. Yet there is no clear agreement in the literature on the main components of social capabilities or how to measure them. Our framework argues that the role of capabilities in catching up needs to understand them in terms of structural transformation, economic and social inclusion, state´s autonomy and accountability. Without progress in these dimensions within-country inequality may increase and might in turn lead to stagnating growth and slim prospects for global income convergence.
A Novel UPLC-MS/MS Method for the Determination of Salvianolic Acid A in Rat Urine, Feces, and Bile and its Application to Excretion Study
Authors: Sun Jialin , Xu Wen , Song Junke , Li Xiao , Guo Qie , Sun Wei , Han Bing , Du Guanhua , Jing Fanbo 
Published: December 2017

Background:Salvianolic acid A (SAA) is a polyphenolic acid extracted from Salvia miltiorrhiza Bunge. It showed protective effect against diabetic complications after oral administration with a low bioavailability of 1.42%. Attempts have been made to develop it into a new medication. Intracorporal process of SAA is indistinct and no report regarding the excretion is available. Our preliminary experiment revealed that previous reported methods were unsuitable for the excretion study due to the serious matrix effect.Methods:To better clarify its pharmacokinetics and avoid the interference of complex endogenous substances, a sensitive UPLC-MS/MS method with a better resolution was developed for the excretion study of SAA for the first time. The analytes were separated by reversed-phase chromatography with acetonitrile-water (containing 0.1% formic acid) gradient elution. The mass spectrometer was operated in the negative ESI mode and multiple reaction monitoring mode.Results:This method was linear over the concentration range of 2.5-100, 5-100 and 5-100 ng/mL in urine, feces and bile, respectively. The accuracy, precision, stability, recovery and matrix effect were satisfactory in all matrices examined. The validated method was successfully applied to an excretion study in rats. After oral administration of 20 mg/kg, the average accumulated excretion amount of SAA in urine, feces and bile were 99.80, 32046.30 and 161.03 ng, respectively.Conclusion:A quick but low elimination was observed. The date is useful for the clinical trial design of SAA.