Miracle-dz/UniFAR-FTUs huggingface dataset:
Costly Search and Design

Firms compete by choosing both a price and a design from a family of designs that can be represented as demand rotations. Consumers engage in costly sequential search among firms. Each time a consumer pays a search cost he observes a new offering. An offering consists of a price quote and a new good, where goods might vary in the extent to which they are good matches for the consumer. In equilibrium, only two design- styles arise: either the most niche where consumers are likely to either love or loathe the product, or the broadest where consumers are likely to have similar valuations. In equilibrium, different firms may simultaneously offer both design-styles. We perform comparative statics on the equilibrium and show that a fall in search costs can lead to higher industry prices and profits and lower consumer surplus. Our analysis is related to discussions of how the internet has led to the prevalence of niche goods and the "long tail" phenomenon.
Tolerance of benthic macrofauna to hypoxia and anoxia in shallow coastal seas: a realistic scenario

Oxygen depletion can lead to the collapse of benthic ecosystems, i.e. to dead zones, and large-scale biodiversity loss. Based on mortality and survival, we evaluated ranges of sensi- tivity and tolerance to hypoxia levels, duration of anoxia and H2S exposure across taxa and key life habits. Experiments were conducted on a sublittoral soft-bottom under realistic in situ conditions in a community setting featuring both a well-developed epi- and infauna. Overall, 495 individuals representing 40 species were examined over almost 1000 h (using time-lapse camera and sensor arrays). Mortality started at dissolved oxygen (DO) concentrations <0.5 ml l �1 and centred at the transition from severe hypoxia to early anoxia. A total of 58% of the individuals belonging to 27 species died. Thirteen species (39 individuals) died exclusively during anoxia. All of the individu- als that died during hypoxia, and most of those that died during anoxia, did so before the onset of hydrogen sulphide (H2S). In 11 species, all individuals survived: survival rates were highest among molluscs, anthozoans and ascidians. In contrast, most polychaetes, decapods and echino- derms died. Epifauna was more vulnerable than infauna, mobile forms were more vulnerable than sessile forms, and predators more vulnerable than deposit-feeders and suspension-feeders. While hypoxia primarily affected total abundance, anoxia significantly reduced the number of species. The former represents a quantitative, the latter a qualitative decline in ecosystem function. Most of the macrofauna may initially survive shorter-term (day-long) or intermittent hypoxia, but the onset of anoxia marks community collapse and biodiversity loss.
Path Tracking Control Problem Formulation of an LHD Loader

Load-haul-dump units (LHD) are loader-type vehicles that arefre quently employed in the underground mines for transfer of ore from the loading point to ore pass. Because they have to travel in the relatively narrow and restricted underground galleries, they have less height and are narrower than the ordinary mechanical loaders that are used in construction work. Furthermore, they are articu lated in the middle in order to be able to better negotiate the curves. Automatic navigation of these units is among the essential tasks for the prospect of their fully automated operation. Path tracking prop erty of this class of vehicles is different than it is for conventional vehicles. The vehicle must move in both forward and backward di rections. Moreover, due to the vehicle's relatively slow speed, study of the kinematics of motion is sufficient for navigation purposes and design of motion controller. This article deals with formulating the equations governing the mechanics of motion and the control problem to be used for their path tracking control.
Association between platelet reactivity and circulating platelet-derived microvesicles in patients with acute coronary syndrome

Abstract High on-treatment platelet reactivity (HPR) to clopidogrel has been shown to increase the risk of cardiovascular events. Platelet-derived microvesicles (PMVs) may be prothrombotic and contribute to the risk of recurrent events observed in patients with HPR. However, PMVs may also serve as biomarkers and be used to assess platelet function. We investigated the association between platelet responses to clopidogrel (measured by whole blood impedance aggregometry) and circulating PMVs in patients with acute coronary syndrome (ACS). Blood samples were obtained at discharge from 200 patients with ACS who had undergone percutaneous coronary intervention (PCI). All patients were loaded with aspirin and clopidogrel before PCI. ADP-induced whole blood impedance aggregometry and measurement of PMVs were performed. Cut-off values for HPR and other reactivity (i.e. normal on-treatment reactivity, NPR and low on-treatment reactivity, LPR) to clopidogrel were set according to data from large prospective studies. We measured PMVs as phosphatidylserine and CD42a positive vesicles, together with CD62P or CD40L, using flow cytometry. ADP-induced platelet aggregation revealed that approximately 20% of patients had HPR. Levels of PMVs were almost two-fold higher in the HPR group compared with patients without HPR (for both CD42a- and CD62P-positive PMVs, p < 0.01). Furthermore, patients with LPR to clopidogrel had significantly fewer PMVs exposing CD62P than patients with HPR or those with NPR to clopidogrel. Patients with HPR during clopidogrel treatment have elevated levels of circulating PMVs, indicating ongoing platelet activation despite clopidogrel treatment. Moreover, in patients with LPR to clopidogrel, circulating PMV numbers are decreased. Taken together, our data suggest that PMVs are potential biomarkers of antiplatelet responses to clopidogrel. If PMVs also have prognostic value after, ACS should be tested in future studies.
The Process of Social Entrepreneurship: Creating Opportunities Worthy of Serious Pursuit

All acts of entrepreneurship start with the vision of an attractive opportunity. 1 For social entrepreneurs, an “attractive” opportunity is one that has sufficient potential for positive social impact to justify the investment of time, energy, and money required to pursue it seriously. Despite popular sayings, attractive entrepreneurial opportunities do not come knocking at the door fully formed. Nor are they out there, like lost treasures, simply waiting to be discovered by the lucky or observant. Rather, they have to be conceived, developed, and refined in a dynamic, creative, and thoughtful process. This note provides a framework to guide social entrepreneurs through the process of creating a worthwhile opportunity. It is designed to help increase the chances of success for anyone contemplating the journey of social entrepreneurship, and it may also be helpful for those considering investing in new social ventures. Our model breaks the opportunity creation process into two major steps (see Figure 1). First, a social entrepreneur generates a promising idea. Second, the social entrepreneur attempts to develop that idea into an attractive opportunity. It is natural to think of the generation step as an act of pure creativity and the development step as purely analytic and logical. However, both steps combine inspiration, insight, and imagination with research, logic, and analysis. Innovative ideas can be generated systematically, based on keen observation and reasoning, as well as creativity. 2 At the same time, converting a promising idea into a workable and attractive opportunity requires an on-going creative process working hand-in-hand with focused analysis, experimentation, and sometimes even launching the initial stages of a venture. We depict the development step as a funnel. Social entrepreneurs add the most significant value in this stage of the process, and few promising ideas make it through the development funnel to become opportunities worth pursuing in the long-term.
Inhibition of phenylephrine‐induced cardiac hypertrophy by docosahexaenoic acid

Many of the cardiovascular benefits of fish oil result from the antiarrhythmic actions of the n‐3 polyunsaturated lipids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). The beneficial effects of DHA/EPA in patients with coronary artery disease and myocardial infarction may also result from modulation of the myocardial hypertrophic response. Hypertrophy was assessed in neonatal cardiomyocytes exposed to phenylephrine (PE) by measuring cell surface area, total protein synthesis (14C leucine incorporation), and the organization of sarcomeric α‐actinin and by monitoring expression of atrial natriuretic factor (ANF). We report that PE induced a twofold increase in cell surface area and protein synthesis in cardiomyocytes. The hypertrophied cardiomyocytes also exhibited increased expression of ANF in perinuclear regions and organization of sarcomeric α‐actinin into classical z‐bands. Treatment of cardiomyocytes with 5 μM DHA effectively prevented PE‐induced hypertrophy as shown by inhibition of surface area expansion and protein synthesis, inhibition of ANF expression, and prevention of α‐actinin organization into z‐bands. DHA treatment prevented PE‐induced activation of Ras and Raf‐1 kinase. The upstream inhibition of Ras → Raf‐1 effectively prevented translocation and nuclear localization of phosphorylated extracellularly regulated kinase 1 and 2 (Erk1/2). These effects consequently led to inhibition of nuclear translocation, and hence, activation of the downstream signaling enzyme p90 ribosomal S6 kinase (p90rsk). These results indicate that PE‐induced cardiac hypertrophy can be minimized by DHA. Our results suggest that inhibition of Ras → Raf‐1 → Erk1/2 → p90rsk → hypertrophy is one possible pathway by which DHA can inhibit cardiac hypertrophy. In vivo studies are needed to confirm these in vitro effects of DHA. © 2004 Wiley‐Liss, Inc.
Rapid screening mitochondrial DNA mutation by using denaturing high-performance liquid chromatography.

AIM To optimize conditions of DHPLC and analyze the effectiveness of various DNA polymerases on DHPLC resolution, and evaluate the sensitivity of DHPLC in the mutation screening of mitochondrial DNA (mtDNA). METHODS Two fragments of 16s gene of mitochondrial DNA (one of them F2 is a mutant fragment) and an A3243G mutated fragment were used to analyze the UV detection limit and determine the minimum percentage of mutant PCR products for DHPLC and evaluate effects of DNA polymerases on resolution of DHPLC. Under the optimal conditions, we analyzed the mtDNA mutations from muscle tissues of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) and screened blindly for variances in D-loop region of mtDNA from human gastric tumor specimen. RESULTS Ten A3243G variants were detected in 12 cases of MELAS, no alterations were detected in controls and these results were consistent with the results obtained by analysis of RFLP with ApaI. We also identified 26 D-loop variances in 46 cases of human gastric cancer tissues and 38 alterations in 13 gastric cancer cell lines. The mutation of mtDNA at 80 ng PCR products containing a minimum of 5% mutant sequences could be detected by using DHPLC with UV detector. Moreover, Ampli-Taq Gold polymerase was equally as good as the proofreading DNA polymerase (e.g., Pfu) in eliminating the false positive produced by Taq DNA polymerases. CONCLUSION DHPLC is a powerful, rapid and sensitive mutation screening method for mtDNA. Proofreading DNA polymerase is more suitable for DHPLC analysis than Taq polymerase.
Staying in the Classroom and Out of the Maternity Ward? The Effect of Compulsory Schooling Laws on Teenage Births

This article investigates whether increasing mandatory educational attainment through compulsory schooling legislation encourages women to delay childbearing. We use variation induced by changes in compulsory schooling laws in both the US and Norway to estimate the effect in two very different institutional environments. We find evidence that increased compulsory schooling does in fact reduce the incidence of teenage childbearing in both the US and Norway, and these estimates are quite robust to various specification checks. These results suggest that legislation aimed at improving educational outcomes may have spillover effects onto the fertility decisions of teenagers.
Memory in the aging brain: Doubly dissociating the contribution of the hippocampus and entorhinal cortex

Since the time of Aristotle it has been thought that memories can be divided into two basic types; conscious recollections and familiarity‐based judgments. Neuropsychological studies have provided indirect support for this distinction by suggesting that different regions within the human medial temporal lobe (MTL) are involved in these two forms of memory, but none of these studies have demonstrated that these brain regions can be fully dissociated. In a group of nondemented elderly subjects, we found that performance on recall and recognition tests was predicted preferentially by hippocampal and entorhinal volumes, respectively. Structural equation modeling revealed a double dissociation, whereby age‐related reductions in hippocampal volume resulted in decreases in recollection, but not familiarity, whereas entorhinal volume was preferentially related to familiarity. The results demonstrate that the forms of episodic memory supported by the human hippocampus and entorhinal cortex can be fully dissociated, and indicate that recollection and familiarity reflect neuroanatomically distinct memory processes. © 2007 Wiley‐Liss, Inc.
An elementary solution of a minimax problem arising in algorithms for automatic mesh selection

We fill in some details in the solution of a minimax problem arising in automatic mesh selection. We supply two proofs of a result that, while simple, deserves the attention, in particular because we will need it to establish the complexity of an algorithm for factorization of bivariate approximate polynomials in an upcoming paper.
An amiloride‐sensitive H+‐gated Na+ channel in Caenorhabditis elegans body wall muscle cells

About 30 genes are predicted to encode degenerin/epithelial sodium channels (DEG/ENaCs) in Caenorhabditis elegans but the gating mode of these channels has not been determined. Using the whole‐cell configuration of the patch‐clamp technique in acutely dissected C. elegans, we investigated the effects of H+ as a potential activating factor of DEG/ENaCs on electrical properties of body wall muscle cells. Under current‐clamp conditions, decreasing external pH from 7.2 to 6.1 led to a reversible depolarization of muscle cells associated with a decrease in input resistance which was partially inhibited by amiloride. Under voltage‐clamp conditions, extracellular acidification activated an inward desensitizing current at −60 mV. In the absence of external Ca2+, H+‐gated channels were found to be slightly more permeable to Na+ than to K+ and were blocked by amiloride with a K0.5 of 31 μm at −60 mV. An inward current could be also activated by protons in a GABA receptor null mutant in the presence of d‐tubocurare and in an unc‐105 null mutant. These results demonstrate that ion channels sharing common properties with mammalian acid‐sensing ion channels (ASICs) are functional in C. elegans muscle which should prove useful for understanding proton sensing in animals.
Perfusion Computed Tomography-Guided Intravenous Thrombolysis for Acute Ischemic Stroke beyond 4.5 Hours: A Case-Control Study

Background: Extending the therapeutic window of intravenous thrombolysis for acute ischemic stroke beyond the established 4.5-hour limit is of critical importance in order to increase the proportion of thrombolysed stroke patients. In this setting, the capacity of MRI to select acute stroke patients for reperfusion therapies in delayed time windows has been and is being tested in clinical trials. However, whether the more available and cost-effective perfusion computed tomography (PCT) may be useful to select candidates for delayed intravenous thrombolysis remains largely unexplored. We aimed to evaluate the safety and efficacy of PCT-guided intravenous thrombolysis beyond 4.5 h after stroke onset. Methods: We prospectively studied all consecutive acute ischemic stroke patients treated with intravenous tissue plasminogen activator (tPA) in our stroke unit between January 2008 and December 2010. Patients treated within 0– 4.5 h were treated according to non-contrast CT (NCCT) criteria. Beyond 4.5 h, patients received intravenous tPA according to PCT criteria, i.e. an infarct core on cerebral blood volume (CBV) maps not exceeding one third of the middle cerebral artery (MCA) territory and tissue at risk as defined by mean transit time-CBV mismatch greater than 20%. Predetermined primary endpoints were symptomatic hemorrhagic transformation and favorable long-term outcome, while early neurological improvement and MCA recanalization were considered secondary endpoints. Statistical analysis included bivariate comparisons between the two groups for each endpoint and logistic regression models when significance was found in bivariate analyses. This study was approved by our local ethics committee. Results: A total of 245 patients received intravenous thrombolysis. After the groups were matched by baseline National Institutes of Health Stroke Scale score, 172 patients treated at <4.5 h and 43 patients treated at >4.5 h were finally included. Early and late groups were comparable regarding baseline variables; only cardioembolic etiology was more frequent in the >4.5 h group. Rates of symptomatic hemorrhagic transformation (2.9% in the <4.5 h group vs. 2.3% in the >4.5 h group; p = 1.0) and good long-term outcome (64.5 vs. 60.5%, respectively; p = 0.620) were similar between the groups. However, delayed intravenous thrombolysis was independently associated with a worse early clinical course [odds ratio (OR) 2.07, 95% confidence interval (CI) 1.04–4.1; p = 0.038] and lower 2-hour MCA recanalization rates (OR 0.4, 95% CI 0.17–0.92; p = 0.03). Conclusion: Primary safety and efficacy endpoints were comparable between the early and delayed thrombolysis groups. The results of our exploratory study may justify a randomized clinical trial to test the safety and efficacy of PCT-guided intravenous thrombolysis in acute ischemic stroke patients presenting beyond 4.5 h from symptom onset.
Intima-media thickening in patients with familial Mediterranean fever.

OBJECTIVE The aim of this study was to assess the frequency of atherosclerotic plaques and intima-media thickness (IMT) in patients with FMF and suitable controls. METHODS We studied 100 (46 males, 54 females; mean age: 40 +/- 6 years) patients with FMF. Also 94 (15 males, 79 females; mean age: 41 +/- 7 years) patients with SLE and 103 (44 males, 59 females; mean age: 40 +/- 5 years) apparently healthy volunteers were included as the control groups. Subclinical atherosclerosis was assessed by investigating atherosclerotic plaques and measuring IMT from carotid and common femoral arteries using B-mode ultrasonography (USG). Traditional atherosclerotic risk factors were also assessed. RESULTS Both FMF and SLE patients had significantly higher carotid (C-IMT) and femoral artery IMT (F-IMT) compared with healthy controls. This was also true after adjustment for atherosclerotic risk factors. Only patients with SLE were found to have higher frequency of atherosclerotic plaques in the carotid and in the carotid and/or femoral artery. When all atherosclerotic risk factors were adjusted, again only patients with SLE were found to have risk for atherosclerotic plaques. In FMF, whereas the presence of atherosclerotic plaques was only associated significantly with diabetes mellitus; C-IMT was correlated with age, BMI and fasting glucose; and F-IMT with age and BMI. CONCLUSIONS Increased atherosclerosis defined as the presence of plaques was not observed in patients with FMF. The significance of increased C- and F-IMT among patients with FMF must be further assessed.
Treatment for meralgia paraesthetica.

BACKGROUND Meralgia paraesthetica is a clinical syndrome for which a number of treatments are in common use, including conservative measures, injection of corticosteroid with local anaesthetic and surgery. We aimed to examine the evidence for the relative efficacy of these interventions. This review was first published in 2008. Searches were updated in 2010 and 2012. OBJECTIVES To assess the relative efficacy of commonly used treatments for meralgia paraesthetica. SEARCH METHODS We searched the Cochrane Neuromuscular Disease Group Specialized Register (1 October 2012), CENTRAL (2012, issue 9 in The Cochrane Library), MEDLINE (January 1966 to October 2012), EMBASE (January 1980 to October 2012) and CINAHL Plus (January 1937 to October 2012) for randomised controlled studies. Non-randomised studies were identified by searching MEDLINE (January 1966 to October 2012) and EMBASE (January 1980 to October 2012). We also inspected the reference lists of these studies. SELECTION CRITERIA We were unable to identify any randomised controlled trials (RCTs) or quasi-RCTs. We therefore looked for high quality observational studies meeting the following criteria: (1) At least five cases of meralgia paraesthetica. (2) Follow-up of at least three months after intervention (if any). (3) At least 80% of cases followed up. DATA COLLECTION AND ANALYSIS Three authors independently extracted relevant data from each study meeting the selection criteria and transferred into a data extraction form. MAIN RESULTS We found no RCTs or quasi-RCTs in the original review or updates in 20011 and 2012. Cure or improvement have been described in high quality observational studies: (1) A single study describes spontaneous improvement of meralgia paraesthetica in 20 (69%) of 29 cases. (2) Four studies evaluating the injection of corticosteroid and local anaesthetic found cure or improvement in 130 (83%) out of a combined total of 157 cases. (3) Surgical treatments have been found to be beneficial in 264 (88%) out of 300 cases treated with decompression (nine studies); and 45 (94%) out of 48 cases treated with neurectomy (three studies). (4) Ninety-nine (97%) out of 102 patients with iatrogenic meralgia paraesthetica recovered completely (three studies). AUTHORS' CONCLUSIONS In the absence of any published RCTs or quasi-RCTs, the objective evidence base for treatment choices in meralgia paraesthetica is weak. High quality observational studies report comparable high improvement rates for meralgia paraesthetica following local injection of corticosteroid and surgical interventions (either nerve decompression or neurectomy). However, a similar outcome has been reported without any intervention in a single natural history study.