bluuebunny/crossref_metadata_2025 huggingface dataset:
Producing Space and Locality Through Cultural Displays
Authors: Donnelly Laura
Published: May 2016

The cultural complexity—and potential for identity building—of museums and cultural displays can be potentially powerful spaces of cultural negotiation; in a postcolonial or diasporic setting, the production of locality through cultural displays can serve as a home surrogate (albeit temporarily) for deterritorialized peripheral subjects. However, when these productions (whether they be museums, festivals, or other events of representation) are commoditized and sponsored by socially dominant groups (such as the French government), so that outsiders (nondiasporic people, i.e., the general public) can consume them, what kinds of interactions and clashes can take place? This article aims to answer this question, through the examination of space in a French Antillean festival in Paris: Rue Créole, illustrating the production of locality in Rue Créole through the spatial construction of the venue, and then by examining the production of space and its implications in the festival’s musical performances. Ultimately, I argue that in postcolonial situations, socially produced space can result in polyrhythmic, performatively doubled ensembles and that this in itself is a mark of colonial relation.
Original Research: Atorvastatin prevents rat cardiomyocyte hypertrophy induced by parathyroid hormone 1–34 associated with the Ras-ERK signaling
Authors: Liu Xiaogang , Zou Chunbo , Yu Chengyuan , Xie Rujuan , Sui Manshu , Mu Suhong , Li Li , Zhao Shilei
Published: May 2016

We investigated the effects of atorvastatin (Ator) on cardiomyocyte hypertrophy (CMH) induced by rat parathyroid hormone 1–34 (PTH1–34) and Ras-extracellular signal regulated protein kinases 1/2 (ERK1/2) signaling. Rat cardiomyocytes were randomly divided into seven groups: normal controls (NC), PTH1–34 (10−7 mol/L), Ator (10−5 mol/L), farnesyl transferase inhibitors-276 (FTI-276, 4 × 10−5 mol/L), PTH1–34 + Ator, PTH1–34 + FTI-276 and PTH1–34 + Ator + mevalonic acid (MVA, 10−4 mol/L). After treatment, the hypertrophic responses of cardiomyocytes were assessed by measuring cell diameter, detecting protein synthesis, and single-cell protein content. The concentrations of hypertrophic markers such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured by ELISA. Protein expressions of ERK1/2, p-ERK1/2 and Ras were detected by western blotting. The results showed that compared with the PTH1–34 group, cellular diameter, 3H-leucine incorporation, single-cell protein content, ANP and BNP concentration decreased by 12.07 µm, 1622 cpm/well, 84.34 pg, 7.13 ng/L and 20.04 µg/L, respectively, and the expressions of Ras and p-ERK1/2 were downregulated in PTH1–34 + Ator group ( P < 0.05). Compared to the PTH1–34 + Ator group, the corresponding hypertrophic responses and hypertrophic markers increased by 4.95 µm, 750 cpm/well, 49.08 pg, 3.12 ng/L and 9.35 µg/L, respectively, and the expressions of Ras and p-ERK1/2 were upregulated in the PTH1–34 + Ator + MVA group ( P < 0.05). In conclusion, Ator prevents neonatal rat CMH induced by PTH1–34 and Ras-ERK signaling may be involved in this process.
Endovascular Aneurysm Repair Increases Aortic Arterial Stiffness When Compared to Open Repair of Abdominal Aortic Aneurysms
Authors: Gray Cleona , Goodman Patrick , Badger Stephen A. , O’Malley M. Kevin , O’Donohoe Martin K. , McDonnell Ciarán O.
Published: May 2016

Objectives:

The initial survival advantage seen with endovascular aneurysm repair (EVAR) over open repair does not persist in the long term. Pulse wave velocity (PWV) is a measure of arterial stiffness, and increased PWV is an independent risk factor for increased cardiovascular morbidity and mortality. This prospective comparative pilot study examined the effect of implantation of an aortic graft on PWV in patients undergoing open or endovascular aortic aneurysm repair.

Patients and Methods:

Thirty-four patients (15 open and 19 EVAR) were recruited. Patient demographics were similar in both the groups. Pulse wave velocity was calculated for all patients preoperatively and postoperatively using a standardized technique on a Philips IU22 Vascular Ultrasound machine and the results compared.

Results:

An increase in mean PWV following EVAR was demonstrated. The mean postprocedure PWV of 9.7 (± 4.5) cm/sec detected in the open group was significantly lower than the elevated 12.2 (± 4.5) cm/sec detected in the EVAR group. The surgical group also demonstrated a mean decrease of 0.2 (± 4.9) cm/sec in PWV following open repair compared to a mean increase of 3.3 (± 3.7) cm/sec in the EVAR group.

Conclusion:

EVAR patients have a significantly higher postoperative PWV measurement than those undergoing open abdominal aortic aneurysm repair. Patients who have undergone EVAR may be at a higher risk of cardiovascular morbidity in the long term. A larger scale study with a longer prospective follow-up is required.
Passive control of thermoacoustic instabilities in swirl-stabilized combustion at elevated pressures
Authors: Williams L Justin , Meadows Joseph , Agrawal Ajay K
Published: May 2016

In this study, a porous insert is placed at the dump plane of a swirl-stabilized lean premixed combustor to passively suppress thermoacoustic instabilities. The diffuser-shaped annular ring of porous inert material influences the turbulent flow field directly, including recirculation zones and vortical and/or shear layer structures to passively control the acoustic performance of the combustor. The porous inert material is made of silicon carbide–hafnium carbide coated, high-strength, high-temperature-resistant open-cell foam materials. In this study, the porous insert concept is investigated at above-ambient operating pressures to demonstrate its suitability for practical combustion applications. Experiments are conducted in quartz and metal combustors, without and with the porous insert while varying operating pressure, equivalence ratio, and reactant flow rate. Measurements show that the porous insert, and consequent changes in the combustor flow field, decrease the sound pressure levels at the frequency of combustion instability at all operating conditions investigated in this study. The porous insert also decreases the broadband combustion noise, i.e. the measured sound pressure levels over a wide frequency range.
Numerical study of atmospheric ice accretion on rotating geometric cross sections with fins
Authors: Mughal Umair N , Virk Muhammad S
Published: May 2016

This paper describes the numerical study of atmospheric ice accretion on rotating geometric cross sections, circular, hexagon and square, all having fins, to select an optimum geometric cross section for use as a rotating part of a newly-proposed designed icing sensor. Computational fluid dynamics-based numerical analyses were carried out in this research work to understand and analyse the atmospheric ice growth on these rotating cross sections at varying operating and geometric parameters. A comparison of accreted ice profile shapes from numerical analysis was also made with the experiments, carried out at cryospheric environment simulator (CES), Shinjo Japan. A good agreement was found between numerical and experimental results.
Effect of Reynolds number on phase change of water flowing across two heated circular cylinders in tandem arrangement
Authors: Dhar BK , Mahapatra SK , Maharana SK , Sarkar A
Published: May 2016

The situations of fluid flow and heat transfer across an array of cylinders have been quite common in fluid dynamics and, particularly, industry applications. One such situation is flow of water over heated cylinders in a tandem arrangement. The flow of water over heated cylinders faces a phenomenon of phase change from liquid (water) to vapor phase (steam).The mechanism of this phase change is studied through a numerical simulation in this project. The Eulerian model is used in the present simulation method to comprehend the multiphase phenomenon. The effect of Reynolds number on the phase change is studied. The phase change of water in an unsteady flow across cylinders has been prominently affected by Reynolds number. Only critical cases have been discussed in this paper. The volume fraction of water and steam is plotted against the position of flow from inlet to exit of the flow domain that is a channel for a particular flow conditions to demonstrate the phenomenon of heat and mass transfer during the flow of water.
Effect of particle diameter and injection position on the separation performance of cyclone separators
Authors: Liu Lin , Dou Hua-Shu , Chen Xiaoping
Published: May 2016

Effects of the particle diameter and particle injection position on the gas–solid two-phase flow have important implications in the tangential inlet cyclone separator. The Navier–Stokes equation coupled with the Reynolds stress model in Euler coordinate system is adopted to describe the gas flow and the discrete phase model in Lagrange coordinate system is used to calculate the particle trajectories. Results show that the separation efficiency varies with the injection position at the inlet cross-section. It is found that the separation efficiency is increased with the increase of the particle diameter. However, when the particle diameter exceeds a critical size, the particles will deposit on the wall of the conical chamber, which leads to lower separation efficiency. The present simulation indicates that the critical size is 24 [Formula: see text].
Numerical simulation of annular flow boiling in microchannels
Authors: Guo Z , Haynes BS , Fletcher DF
Published: May 2016

Flow boiling in microchannels has been researched for decades due to its potential for heat transfer applications in micro structured devices. The large number of existing experimental datasets and fitted correlations show considerable scatter and lack a mechanistic basis. The computational fluid dynamics (CFD) model developed here applies to boiling in the annular flow regime and provides insights into the underlying behaviour. Analysis of the heat transfer augmentation by interfacial waves is studied. Parametric investigations are performed using the model to understand the impact of important flow and system parameters. The calculated heat transfer coefficients are consistent with those from existing correlations, showing no more scatter than the data used to create them.
Are Muslim countries more prone to violence?
Authors: Gleditsch Nils Petter , Rudolfsen Ida
Published: May 2016

In recent years, most armed conflicts have taken place in Muslim countries. Are Muslim countries more war-prone? Not necessarily, if we look at data for the whole period after World War II. But in the post-Cold War era, most wars are civil wars and Muslim countries have a disproportionate share of these. This is not mainly because conflicts among Muslims have increased, but because other conflicts have declined. Muslim countries are also overrepresented among countries with high levels of other forms of internal violence, including non-state conflict, one-sided violence, highly repressive human rights policies, and countries that practice capital punishment. They also have a higher than average participation in interstate conflicts. This is not a “clash of civilizations”—most of the victims are Muslims. We list several hypotheses, apart from religion itself, for why this pattern has emerged, including colonial history, interventions from major powers, and economic and political development. Finally, on a more optimistic note, while many Muslims are exposed to violence, four of the five countries with the largest Muslim populations do not currently experience civil war.
Alternatives to the Movie Sandwich Habit
Authors: Sprinkle Therese A. , Urick Michael J.
Published: May 2016

Instructors often leverage movies in their classroom to illustrate management concepts. Sometimes, instructors fall into the “movie sandwich” habit, which may not allow for a comprehensive mastery of complex concepts. In this article, we define what we mean by “movie sandwich” and provide immersive alternatives to this approach to illustrate power and leadership theories. The two alternative approaches we advocate here are “movie club,” in which students are guided through an interactive discussion outside of class related to topics, and “modified gamification,” in which students are provided objectives and awarded points for showing mastery of concepts illustrated in a movie. These two approaches are demonstrated through practical examples.
Breast Cancer Downstaging Practices and Breast Health Messaging Preferences Among a Community Sample of Urban and Rural Ugandan Women
Authors: Scheel John R. , Molina Yamile , Patrick Donald L. , Anderson Benjamin O. , Nakigudde Gertrude , Lehman Constance D. , Thompson Beti
Published: May 2016

Purpose

Among a community sample of Ugandan women, we provide information about breast cancer downstaging practices (breast self-examination, clinical breast examination [CBE]) and breast health messaging preferences across sociodemographic, health care access, and prior breast cancer exposure factors.

Methods

Convenience-based sampling was conducted to recruit Ugandan women age 25 years and older to assess breast cancer downstaging practices as well as breast health messaging preferences to present early for a CBE in the theoretical scenario of self-detection of a palpable lump (breast health messaging preferences).

Results

The 401 Ugandan women who participated in this survey were mostly poor with less than a primary school education. Of these women, 27% had engaged in breast self-examination, and 15% had undergone a CBE. Greater breast cancer downstaging practices were associated with an urban location, higher education, having a health center as a regular source of care, and receiving breast cancer education ( P < .05). Women indicated a greater breast health messaging preference from their provider (66%). This preference was associated with a rural location, having a health center as a regular source of care, and receiving breast cancer education ( P < .05).

Conclusion

Most Ugandan women do not participate in breast cancer downstaging practices despite receipt of breast cancer education. However, such education increases downstaging practices and preference for messaging from their providers. Therefore, efforts to downstage breast cancer in Uganda should simultaneously raise awareness in providers and support improved education efforts in the community.
Benefit of Delayed Fertility Therapy With Preconception Weight Loss Over Immediate Therapy in Obese Women With PCOS
Authors: Legro Richard S. , Dodson William C. , Kunselman Allen R. , Stetter Christy M. , Kris-Etherton Penny M. , Williams Nancy I. , Gnatuk Carol L. , Estes Stephanie J. , Allison Kelly C. , Sarwer David B. , Diamond Michael P. , Schlaff William D. , Casson Peter R. , Christman Gregory M. , Barnhart Kurt T. , Bates G. Wright , Usadi Rebecca , Lucidi Scott , Baker Valerie , Zhang Heping , Eisenberg Esther , Coutifaris Christos , Dokras Anuja
Published: May 2016

Context:

In overweight/obese women with polycystic ovary syndrome (PCOS), the relative benefit of delaying infertility treatment to lose weight vs seeking immediate treatment is unknown.

Objective:

We compared the results of two, multicenter, concurrent clinical trials treating infertility in women with PCOS.

Design, Setting, and Participants:

This was a secondary analysis of two randomized trials conducted at academic health centers studying women 18–40 years of age who were overweight/obese and infertile with PCOS.

Intervention:

We compared immediate treatment with clomiphene from the Pregnancy in Polycystic Ovary Syndrome II (PPCOS II) trial (N = 187) to delayed treatment with clomiphene after preconception treatment with continuous oral contraceptives, lifestyle modification (Lifestyle: including caloric restriction, antiobesity medication, behavioral modification, and exercise) or the combination of both (combined) from the Treatment of Hyperandrogenism Versus Insulin Resistance in Infertile Polycystic Ovary Syndrome (OWL PCOS) trial (N = 142).

Main Outcome Measures:

Live birth, pregnancy loss, and ovulation were measured.

Results:

In PPCOS II, after four cycles of clomiphene, the cumulative per-cycle ovulation rate was 44.7% (277/619) and the cumulative live birth rate was 10.2% (19/187), nearly identical to that after oral contraceptive pretreatment in the OWL PCOS trial (ovulation 45% [67/149] and live birth: 8.5% [4/47]). In comparison, deferred clomiphene treatment preceded by lifestyle and combined treatment in OWL PCOS offered a significantly better cumulative ovulation rate compared to immediate treatment with clomiphene. (Lifestyle: 62.0% [80/129]; risk ratio compared to PPCOS II = 1.4; 95% confidence interval [CI], 1.1–1.7; P = .003; combined: 64.3% [83/129]; risk ratio compared to PPCOS II = 1.4; 95% CI, 1.2–1.8; P < .001 and a significantly better live birth rate lifestyle: 25.0% [12/48]; risk ratio compared to PPCOS II = 2.5; 95% CI, 1.3–4.7; P = .01 and combined: 25.5% [12/47]; risk ratio compared to PPCOS II = 2.5; 95% CI, 1.3–4.8; P = .01).

Conclusions:

These data show the benefit of improved ovulation and live birth with delayed infertility treatment with clomiphene citrate when preceded by lifestyle modification with weight loss compared with immediate treatment. Pretreatment with oral contraceptives likely has little effect on the ovulation and live birth rate compared with immediate treatment.
The Effect of Local Anesthetic Volume Within the Adductor Canal on Quadriceps Femoris Function Evaluated by Electromyography: A Randomized, Observer- and Subject-Blinded, Placebo-Controlled Study in Volunteers
Authors: Grevstad Ulrik , Jæger Pia , Sørensen Johan Kløvgaard , Gottschau Bo , Ilfeld Brian , Ballegaard Martin , Hagelskjaer Mike , Dahl Jørgen Berg
Published: May 2016

BACKGROUND:

Single-injection adductor canal block (ACB) provides analgesia after knee surgery. Which nerves that are blocked by an ACB and what influence—if any—local anesthetic volume has on the effects remain undetermined. We hypothesized that effects on the nerve to the vastus medialis muscle (which besides being a motor nerve innervates portions of the knee) are volume-dependent.

METHODS:

In this assessor- and subject-blinded randomized trial, 20 volunteers were included. On 3 separate days, subjects received an ACB with different volumes (10, 20, and 30 mL) of lidocaine 1%. In addition, they received a femoral nerve block and a placebo ACB. The effect on the vastus medialis (primary endpoint) and the vastus lateralis was evaluated using noninvasive electromyography (EMG). Quadriceps femoris muscle strength was evaluated using a dynamometer.

RESULTS:

There was a statistically significant difference in EMG response from the vastus medialis, dependent on volume. Thirty-five percent (95% confidence interval [CI], 18–57) of the subjects had an affected vastus medialis after an ACB with 10 mL compared with 84% (95% CI, 62–94) following 20 mL (P = 0.03) and 100% (95% CI, 84–100) when 30 mL was used (P = 0.0001). No statistically significant differences were found between volume and effect on the vastus lateralis (P = 0.81) or in muscle strength (P = 0.15).

CONCLUSIONS:

For ACB, there is a positive correlation between local anesthetic volume and effect on the vastus medialis muscle. Despite the rather large differences in EMG recordings, there were no statistically significant differences in quadriceps femoris muscle strength. Subsequent clinical studies comparing different volumes in a surgical setting, powered to show differences not only in analgesic efficacy, but also in adverse events, are required.
The Perioperative Use of Dexmedetomidine in Pediatric Patients with Congenital Heart Disease: An Analysis from the Congenital Cardiac Anesthesia Society-Society of Thoracic Surgeons Congenital Heart Disease Database
Authors: Schwartz Lawrence I. , Twite Mark , Gulack Brian , Hill Kevin , Kim Sunghee , Vener David F.
Published: May 2016

BACKGROUND:

Dexmedetomidine is a selective α-2 receptor agonist with a sedative and cardiopulmonary profile that makes it an attractive anesthetic for pediatric patients with congenital heart disease (CHD). Although several smaller, single-center studies suggest that dexmedetomidine use is gaining traction in the perioperative setting in children with CHD, there are limited multicenter data, with little understanding of the variation in use across age ranges, procedural complexity, and centers. The aim of this study was to use the Congenital Cardiac Anesthesia Society-Society of Thoracic Surgeons (CCAS-STS) registry to describe patient- and center-level variability in the use of dexmedetomidine in the perioperative setting in children with heart disease.

METHODS:

To describe the use of dexmedetomidine in patients for CHD surgery, we analyzed all index cardiopulmonary bypass operations entered in the CCAS-STS database from 2010 to 2013. Patient and operative characteristics were compared between those who received intraoperative dexmedetomidine and those who did not. Selective outcomes associated with dexmedetomidine use were also described.

RESULTS:

Of the 12,142 operations studied, 3600 (29.6%) received perioperative dexmedetomidine (DEX) and 8542 did not receive the drug (NoDEX). Patient characteristics were different between the 2 groups with the DEX group generally exhibiting both lower patient and procedural risk factors. Patients who received dexmedetomidine were more likely to have a lower level of Society of Thoracic Surgeons mortality complexity than patient who did not receive it. Consistent with their overall lower risk profile, children in the DEX group also demonstrated improved outcomes compared with patients who did not receive dexmedetomidine.

CONCLUSIONS:

We described the growing use of dexmedetomidine in children anesthetized for surgical repair of CHD. Dexmedetomidine appears to be preferentially given to older and larger children who are undergoing less complex CHD surgery. We believe that the data provided in this study are the largest investigating the use of an anesthetic drug in CHD patients. It is also the first analysis of the anesthesia data in the CCAS-STS Congenital Heart Disease database.
Association of Selective Serotonin Reuptake Inhibitors with Transfusion in Surgical Patients
Authors: Sajan Farrah , Conte John V. , Tamargo Rafael J. , Riley Lee H. , Rock Peter , Faraday Nauder
Published: May 2016

BACKGROUND:

The clinical relevance of chronic exposure to selective serotonin reuptake inhibitors (SSRIs) to transfusion in surgical patients is unclear.

METHODS:

We conducted a prospective cohort study involving patients undergoing cardiac, vascular, spinal, and intracranial surgery at 2 academic medical centers. Medication use, demographics, comorbidities, and laboratory values were determined at baseline by patient interview and review of medical records. The primary outcome was transfusion of any hemostatic allogeneic blood product (i.e., fresh frozen plasma, platelets, and/or cryoprecipitate) through postoperative day 2.

RESULTS:

The study sample consisted of 767 patients; 364 patients (47.5%) underwent cardiac surgery and the remainder underwent noncardiac surgery. Eighty-eight patients (11.5%) used SSRIs preoperatively. Among cardiac patients, the absolute number of allogeneic transfusions was higher for SSRI users than nonusers (2 [0–6] vs 0 [0–2], median [25%–75%], respectively, P = 0.008), and a similar trend was observed for noncardiac surgery. After adjusting for covariates using ordinal logistic regression, preoperative SSRI use was associated with an approximately 2-fold (odds ratio, 2.2; 95% confidence interval, 1.2–3.98) increase in odds of exposure to allogeneic hemostatic blood products; similar results were observed using propensity score adjustment (odds ratio, 1.85; 95% confidence interval, 1.11–3.07). A significant interaction between SSRI use and surgery type, age, sex, or concurrent antiplatelet therapy was not found; however, heterogeneity in magnitude of effect could not be excluded.

CONCLUSIONS:

Preoperative use of SSRIs is associated with increased exposure to allogeneic hemostatic blood products in surgical patients at high risk for perioperative bleeding. Determining whether perioperative continuation or withdrawal of SSRIs produces a net clinical benefit requires randomized controlled trials.
The Risks to Patient Privacy from Publishing Data from Clinical Anesthesia Studies
Authors: O’Neill Liam , Dexter Franklin , Zhang Nan
Published: May 2016

In this article, we consider the privacy implications of posting data from small, randomized trials, observational studies, or case series in anesthesia from a few (e.g., 1–3) hospitals. Prior to publishing such data as supplemental digital content, the authors remove attributes that could be used to re-identify individuals, a process known as “anonymization.” Posting health information that has been properly “de-identified” is assumed to pose no risks to patient privacy. Yet, computer scientists have demonstrated that this assumption is flawed. We consider various realistic scenarios of how the publication of such data could lead to breaches of patient privacy. Several examples of successful privacy attacks are reviewed, as well as the methods used. We survey the latest models and methods from computer science for protecting health information and their application to posting data from small anesthesia studies. To illustrate the vulnerability of such published data, we calculate the “population uniqueness” for patients undergoing one or more surgical procedures using data from the State of Texas. For a patient selected uniformly at random, the probability that an adversary could match this patient’s record to a unique record in the state external database was 42.8% (SE < 0.1%). Despite the 42.8% being an unacceptably high level of risk, it underestimates the risk for patients from smaller states or provinces. We propose an editorial policy that greatly reduces the likelihood of a privacy breach, while supporting the goal of transparency of the research process.
Mapping General Anesthetic Sites in Heteromeric γ-Aminobutyric Acid Type A Receptors Reveals a Potential For Targeting Receptor Subtypes
Authors: Forman Stuart A. , Miller Keith W.
Published: May 2016

IV general anesthetics, including propofol, etomidate, alphaxalone, and barbiturates, produce important actions by enhancing γ-aminobutyric acid type A (GABAA) receptor activation. In this article, we review scientific studies that have located and mapped IV anesthetic sites using photoaffinity labeling and substituted cysteine modification protection. These anesthetics bind in transmembrane pockets between subunits of typical synaptic GABAA receptors, and drugs that display stereoselectivity also show remarkably selective interactions with distinct interfacial sites. These results suggest strategies for developing new drugs that selectively modulate distinct GABAA receptor subtypes.
A Path Through the Wilderness: Time Discounting in Growth Models
Authors: Duarte Pedro Garcia
Published: May 2016

Although economists recognized long ago that “time enters into all economic questions,” as William Stanley Jevons wrote, the ways they treated and modeled time varied substantially in the last century. While in the 1920s there was a distinctive Cambridge tradition against discounting utilities of future generations, to which Frank Ramsey subscribed, postwar neoclassical growth economists (of the “Ramsey-Cass-Koopmans model”) applied the discount factor either to the individual's or the social planner's decision making as a technical requirement of dynamic general equilibrium models. My goal in this article is to analyze the different communities and their interpretative practices regarding discounting: the Cambridge economists in the 1920s, some American mathematicians in the 1920s and 1930s, a group of economists working on economic dynamics from the 1930s to the 1950s, the founders of the optimal growth model and those bringing recursive methods to macroeconomics in the 1950s and 1960s, and, finally, those who reacted against this utilitarian approach to social planning problems. With this I hope to shed some historical light on how a practice that was condemned as ethically indefensible when applied to intergenerational comparisons became a technical requirement in dynamic models of either a consumer or a planner deciding the intertemporal allocation of resources.
Quantitative analysis of 3D extracellular matrix remodelling by pancreatic stellate cells
Authors: Robinson Benjamin K. , Cortes Ernesto , Rice Alistair J. , Sarper Muge , del Río Hernández Armando
Published: May 2016

Extracellular matrix (ECM) remodelling is integral to numerous physiological and pathological processes in biology, such as embryogenesis, wound healing, fibrosis and cancer. Until recently, most cellular studies have been conducted on 2D environments where mechanical cues significantly differ from physiologically relevant 3D environments, impacting cellular behaviour and masking the interpretation of cellular function in health and disease. We present an integrated methodology where cell-ECM interactions can be investigated in 3D environments via ECM remodelling. Monitoring and quantification of collagen-I structure in remodelled matrices, through designated algorithms, show that 3D matrices can be used to correlate remodelling with increased ECM stiffness observed in fibrosis. Pancreatic stellate cells (PSCs) are the key effectors of the stromal fibrosis associated to pancreatic cancer. We use PSCs to implement our methodology and demonstrate that PSC matrix remodelling capabilities depend on their contractile machinery and β1 integrin-mediated cell-ECM attachment.
Reprogrammable CRISPR/Cas9-based system for inducing site-specific DNA methylation
Authors: McDonald James I. , Celik Hamza , Rois Lisa E. , Fishberger Gregory , Fowler Tolison , Rees Ryan , Kramer Ashley , Martens Andrew , Edwards John R. , Challen Grant A.
Published: May 2016

Advances in sequencing technology allow researchers to map genome-wide changes in DNA methylation in development and disease. However, there is a lack of experimental tools to site-specifically manipulate DNA methylation to discern the functional consequences. We developed a CRISPR/Cas9 DNA methyltransferase 3A (DNMT3A) fusion to induce DNA methylation at specific loci in the genome. We induced DNA methylation at up to 50% of alleles for targeted CpG dinucleotides. DNA methylation levels peaked within 50 bp of the short guide RNA (sgRNA) binding site and between pairs of sgRNAs. We used our approach to target methylation across the entire CpG island at the CDKN2A promoter, three CpG dinucleotides at the ARF promoter, and the CpG island within the Cdkn1a promoter to decrease expression of the target gene. These tools permit mechanistic studies of DNA methylation and its role in guiding molecular processes that determine cellular fate.
Monetary Policy, Financial Stability, and the Zero Lower Bound
Authors: Fischer Stanley
Published: May 2016

Much has happened in the world of central banking in the past decade. In this paper, I focus on three issues associated with the zero lower bound (ZLB) on short-term nominal interest rates and the nexus between monetary policy and financial stability: 1) whether we are moving toward a permanently lower long-run equilibrium real interest rate; 2) what steps can be taken to mitigate the constraints imposed by the ZLB; and 3) whether and how financial stability considerations should be incorporated in the conduct of monetary policy. These important topics deserve the attention of both academic and government professionals.
Capital Flows: Expansionary or Contractionary?
Authors: Blanchard Olivier , Ostry Jonathan D. , Ghosh Atish R. , Chamon Marcos
Published: May 2016

The workhorse open-economy macro model suggests that capital inflows are contractionary because they appreciate the currency and reduce net exports. Emerging market policy makers, however, believe that inflows lead to credit booms and rising output; the evidence appears to go their way. To reconcile theory and reality, we extend the set of assets in the Mundell-Fleming model to include both bonds and non-bonds. At a given policy rate, inflows may decrease the rate on non-bonds, stimulating financial intermediation and, potentially, output as well. We explore the implications, and find support for the key predictions in the data.
Copyright Infringement in the Market for Digital Images
Authors: Luo Hong , Mortimer Julie Holland
Published: May 2016

Digital technologies for sharing creative goods create new opportunities for copyright infringement and challenge established enforcement methods. We establish several important facts about the nature of copyright infringement and efforts to settle past infringing use in the market for digital images. Infringement in this, and many other markets, is often uninformed: users may be unaware that their use infringes, and may lack information about the price of a license. The uninformed nature of infringement implies that price may not be the primary factor in the decision to settle past use; in contrast, non-price factors may significantly affect settlement outcomes.
Agglomeration of Invention in the Bay Area: Not Just ICT
Authors: Forman Chris , Goldfarb Avi , Greenstein Shane
Published: May 2016

We document that the Bay Area rose from 4% of all successful US patent applications in 1976 to 16% in 2008. This is partly driven by the increase in the prevalence of information and communication technology; however, even for patents unrelated to information and communication technology, we see a disproportionate increase in the share of US patents from the Bay Area. We interpret this growth as a trend to coagglomeration in invention across technologies, and explore different dimensions of this trend.
Firm-Level Dispersion in Productivity: Is the Devil in the Details?
Authors: Foster Lucia , Grim Cheryl , Haltiwanger John , Wolf Zoltan
Published: May 2016

We explore current interpretations of firm-level dispersion in revenue-based productivity measures. Since revenue function estimates using proxy methods differ from factor elasticities, the residual emerging from this method remains a combination of demand and technical effciency shocks, and is not equal to the concept of revenue productivity that plays an important role in recent literature on misallocation. This has implications for applications where measured revenue productivity dispersion is used as an indicator of misallocation. Our empirical evidence suggests, under iso-elastic demand, measured dispersion may indicate either distortions or variation in demand shocks and technical effciency or all of the above.
Regulation, Institutions, and Productivity: New Macroeconomic Evidence from OECD Countries
Authors: Égert Balázs
Published: May 2016

This paper seeks to understand the drivers of country-level multi-factor productivity (MFP) with a special emphasis on product and labour market policies and the quality of institutions. For a panel of OECD countries, we find that anticompetitive product market regulations reduce MFP levels and that higher innovation intensity and greater openness result in higher MFP. We also find that the impact of product market regulations on MFP may depend on the level of labour market regulations. Better institutions, a more business friendly environment and lower barriers to trade and investment amplify the positive impact of R&D spending on MFP. Finally, we also show that cross-country MFP variations can be explained to a considerable extent by cross-country variation in labour market regulations, barriers to trade and investment and institutions.
Crowdsourcing City Government: Using Tournaments to Improve Inspection Accuracy
Authors: Glaeser Edward L. , Hillis Andrew , Kominers Scott Duke , Luca Michael
Published: May 2016

The proliferation of big data makes it possible to better target city services like hygiene inspections, but city governments rarely have the in-house talent needed for developing prediction algorithms. Cities could hire consultants, but a cheaper alternative is to crowdsource competence by making data public and offering a reward for the best algorithm. A simple model suggests that open tournaments dominate consulting contracts when cities can tolerate risk and when there is enough labor with low opportunity costs. We also report on an inexpensive Boston-based restaurant tournament, which yielded algorithms that proved reasonably accurate when tested “out-of-sample” on hygiene inspections.
Productivity and Selection of Human Capital with Machine Learning
Authors: Chalfin Aaron , Danieli Oren , Hillis Andrew , Jelveh Zubin , Luca Michael , Ludwig Jens , Mullainathan Sendhil
Published: May 2016

Economists have become increasingly interested in studying the nature of production functions in social policy applications, with the goal of improving productivity. Traditionally models have assumed workers are homogenous inputs. However, in practice, substantial variability in productivity means the marginal productivity of labor depends substantially on which new workers are hired--which requires not an estimate of a causal effect, but rather a prediction. We demonstrate that there can be large social welfare gains from using machine learning tools to predict worker productivity, using data from two important applications - police hiring and teacher tenure decisions.
Does the Market Value CEO Styles?
Authors: Schoar Antoinette , Zuo Luo
Published: May 2016

We study how investors perceive the skill set that different types of CEOs bring into their companies. We compare CEOs who started their careers during a recession with other CEOs. We show that the announcement return around the appointment of a recession CEO is very significant and positive, and this positive market reaction is driven by cases where a recession CEO replaces a non-recession CEO. Our results indicate that the market assigns a positive and economically meaningful value to a recession CEO, suggesting that there is a limited supply of these types of CEOs in the executive labor market.
Playing the Boys Game: Golf Buddies and Board Diversity
Authors: Agarwal Sumit , Qian Wenlan , Reeb David M. , Sing Tien Foo
Published: May 2016

We study the participation of women in golf, a predominately male social activity, and its influence on their likelihood of serving on a board of directors. Exploiting a novel dataset of all golfers in Singapore, we find that woman golfers enjoy a 54% higher likelihood of serving on a board relative to male golfers. A woman's probability of serving on the board in a large firm or in a predominately male industry increases by 117% to 125% when she plays golf. Joining the boy's informal network appears to facilitate women's entrance or success in the executive labor market.
Identity Economics 2016: Where Do Social Distinctions and Norms Come From?
Authors: Kranton Rachel E.
Published: May 2016

Identity economics provides a framework to analyze economic outcomes by establishing people's identities--not just pecuniary incentives--as primary motivations for choice. The heart of the framework is social difference and norms. This paper engages the emerging economic research into sources of divisions and norms: individuals, families, schools, governments, and social movements. The task at hand is to further to develop the micro-foundations of identity, in order to build a socially framed understandings of human motivation that will yield more robust accounts of behavior and institutions and yet better predictions of the implications of policy.
Too Big to Fail Before the Fed
Authors: Gorton Gary , Tallman Ellis W.
Published: May 2016

“Too-big-to-fail” is consistent with policies followed by private bank clearing houses during financial crises in the U.S. National Banking Era prior to the existence of the Federal Reserve System. Private bank clearing houses provided emergency lending to member banks during financial crises. This behavior strongly suggests that “too-big-to-fail” is not the problem causing modern crises. Rather it is a reasonable response to the threat posed to large banks by the vulnerability of short-term debt to runs.
Bayesian Persuasion in Coordination Games
Authors: Goldstein Itay , Huang Chong
Published: May 2016

We analyze a coordination game of regime change where the policy maker, who tries to increase the probability of the survival of the regime, commits ex ante to abandon the regime automatically when its fundamentals are below a certain threshold. This policy acts as an information transmission mechanism: agents, who decide whether to attack the regime or not, update positively about the fundamentals of the regime when they see that it has not been abandoned, and so they are less likely to attack. Using the commitment ability, the policy maker can thus increase the overall survival probability of the regime.
The Impact of Challenge Quizzes on Student Knowledge
Authors: McGoldrick KimMarie , Schuhmann Peter W.
Published: May 2016

We evaluate the efficacy of a blended formative/summative assessment tool developed to support mastery learning by students without placing undue burden on instructors. Our innovation provides students with an opportunity to take a more difficult “challenge” quiz to demonstrate their command of the material and improve their grade on regular in-class quizzes. The structure of these quizzes motivates students to modify study behaviors (formative component) and take responsibility for knowledge acquisition (summative component). This mastery-based testing approach serves to bring the student's objective of a quality grade in line with the instructor's objective of quality learning.
Rethinking Protection of Those Displaced by Humanitarian Crises
Authors: Martin Susan F.
Published: May 2016

In June 2015, the UN High Commissioner for Refugees announced a landmark event in the history of his organization. UNHCR estimated that there were more refugees and displaced persons than it had counted since its establishment in 1950--almost 60 million who fled conflict and persecution. While certainly large in its own right, the number actually underestimates displacement in today's world. Many millions more are displaced each year and cumulatively from a much broader range of life-threatening humanitarian crises than captured by UNHCR's figures. An average of 26.4 million were displaced annually by acute natural hazards since 2008 and an unknown but sizeable number from gang and cartel violence, electoral and communal violence, nuclear and industrial accidents, and a range of other human made disasters. This paper argues for new legal, institutional and operational frameworks to more effectively address the situation of the totality of displaced persons.
The Rise and Fall of American Growth: Exploring the Numbers
Authors: Crafts Nicholas
Published: May 2016

This paper reviews some of the major claims in Robert Gordon's Rise and Fall of American Growth. His argument that growth of conventional real GDP per person is well below that of real living standards is accepted. It is shown that adding an imputation to GDP for reductions in mortality raises growth substantially, especially between 1929 and 1950. Gordon is also right that total factor productivity growth peaked in the second and third quarters of the twentieth century but his claim that there was a “great leap forward” in the 1940s, stimulated by World War 2, is not persuasive.
Money and Asset Liquidity in Frictional Capital Markets
Authors: Cui Wei , Radde Sören
Published: May 2016

We endogenize asset liquidity and financing constraints in a dynamic general equilibrium model with search frictions on capital markets. Assets traded on frictional capital markets are only partially saleable. Liquid assets, such as fiat money, instead, are not subject to search frictions and can be used to insure idiosyncratic investment risks. Partially saleable assets thus carry a liquidity premium over fully liquid assets. We show that, in equilibrium, low asset saleability is typically associated with lower asset prices, tighter financing constraints, thus stronger demand for public liquidity. Lower asset liquidity feeds into real allocations, constraining real investment, consumption, and production.
Interpreting Tests of School VAM Validity
Authors: Angrist Joshua , Hull Peter , Pathak Parag , Walters Christopher
Published: May 2016

We develop over-identification tests that use admissions lotteries to assess the predictive value of regression-based value-added models (VAMs). These tests have degrees of freedom equal to the number of quasi-experiments available to estimate school effects. By contrast, previously implemented VAM validation strategies look at a single restriction only, sometimes said to measure forecast bias. Tests of forecast bias may be misleading when the test statistic is constructed from many lotteries or quasi-experiments, some of which have weak first stage effects on school attendance. The theory developed here is applied to data from the Charlotte-Mecklenberg School district analyzed by Deming (2014).
How Mortgage Finance Reform Could Affect Housing
Authors: Duca John V. , Muellbauer John , Murphy Anthony
Published: May 2016

Although major changes in mortgage finance have occurred since the subprime bust, several issues remain unresolved, centering on the roles of Fannie Mae, Freddie Mac, and the FHA. We analyze how some reforms might affect house prices in a framework rich enough to simulate the impact of several reforms which change mortgage interest rates and/or loan-to-value (LTV) ratios of first time home buyers, the key drivers of house prices in recent decades. Simulations suggest that ending the GSE interest rate subsidy would have small effects, while changes in capital requirements or maximum FHA loan size limits would have larger effects.
A Simple Model of Subprime Borrowers and Credit Growth
Authors: Justiniano Alejandro , Primiceri Giorgio E. , Tambalotti Andrea
Published: May 2016

The surge in credit and house prices that preceded the Great Recession was particularly pronounced in ZIP codes with a higher fraction of subprime borrowers (Mian and Sufi, 2009). We present a simple model with prime and subprime borrowers distributed across geographic locations, which can reproduce this stylized fact as a result of an expansion in the supply of credit. Due to their low income, subprime households are constrained in their ability to meet interest payments and hence sustain debt. As a result, when the supply of credit increases and interest rates fall, they take on disproportionately more debt than their prime counterparts, who are not subject to that constraint.
Debt Constraints and the Labor Wedge
Authors: Kehoe Patrick , Midrigan Virgiliu , Pastorino Elena
Published: May 2016

Changes in household debt and employment across regions of the U.S. during the Great Recession are highly correlated: regions where the decrease in household debt was most pronounced were also regions where the decline in employment was most severe. We show that the drop in employment in the regions that have experienced the largest decrease in household debt is mostly accounted for by changes in the labor wedge (deviations from a static consumption-leisure choice) as opposed to changes in real wages. We argue that such a pattern is consistent with fluctuations in debt constrain01/2ts in a standard Bewley-Aiyagari model.
Patents and Research Investments: Assessing the Empirical Evidence
Authors: Budish Eric , Roin Benjamin N. , Williams Heidi
Published: May 2016

A well-developed theoretical literature--dating back at least to Nordhaus (1969)--has analyzed optimal patent policy design. We re-present the core trade-off of the Nordhaus model and highlight an empirical question which emerges from the Nordhaus framework as a key input into optimal patent policy design: namely, what is the elasticity of R&D investment with respect to the patent term? We then review the--surprisingly small--body of empirical evidence that has been developed on this question over the nearly half century since the publication of Nordhaus's book.