LLukas22/scidocs huggingface dataset:
Selling a Cheaper Mousetrap: Wal-Mart's Effect on Retail Prices

I quantify the price effect of a low-cost entrant on retail prices using a case-study approach. I consider the effect of Wal-Mart entry on average city-level prices of various consumer goods by exploiting variation in the timing of store entry. The analysis combines two unique data sets, one containing opening dates of all US Wal-Mart stores and the other containing average quarterly retail prices of several narrowly-defined commonly-purchased goods over the period 1982-2002. I focus on 10 specific items likely to be sold at Wal-Mart stores and analyze their price dynamics in 165 US cities before and after Wal-Mart entry. An instrumental-variables specification corrects for measurement error in Wal-Mart entry dates. I find robust price effects for several products, including shampoo, toothpaste, and laundry detergent; magnitudes vary by product and specification, but generally range from 1.5-3% in the short run and four times as much in the long-run. JEL Numbers: L130, L810, E310
Evaluation of plasma human herpesvirus 8 DNA as a marker of clinical outcomes during antiretroviral therapy for AIDS-related Kaposi sarcoma in Zimbabwe.

BACKGROUND
The usefulness of plasma human herpesvirus 8 (HHV-8) DNA as a marker of response to treatment for acquired immunodeficiency syndrome-associated Kaposi sarcoma (AIDS-KS) in an African setting is unknown.


METHODS
We conducted a prospective pilot study at the Parirenyatwa Hospital Kaposi Sarcoma Clinic (Harare, Zimbabwe) to investigate the hypothesis that the clinical response of AIDS-KS is associated with suppression of HHV-8 DNA. Antiretroviral therapy (ART) was provided as coformulation of abacavir, lamivudine, and zidovudine. Clinical response was defined as survival to week 96 with either complete or partial resolution of KS disease.


RESULTS
Ninety ART-naive participants (62 men and 28 women) aged >18 years who had human immunodeficiency virus type 1 (HIV-1) infection and biopsy-confirmed KS were studied; 82% had stage T1 disease. Fifty participants received adjunctive chemotherapy. The median CD4(+) lymphocyte count increased from 124 cells/microL at baseline to 281 cells/microL, the plasma HIV-1 RNA level decreased from 4.69 to <2.60 log(10) copies/mL, the plasma HHV-8 DNA level decreased from 660 to <25 copies/mL, and HHV-8 DNA level in peripheral blood mononuclear cells decreased from 2790 to 37 copies/10(6) cells (P < .001 for each comparison). There were 14 deaths (16%) and 13 patients (15%) lost to follow-up. The most common cause of death was infection. Clinical response of KS occurred in 17 participants (19%). Pretreatment plasma HHV-8 DNA levels of <660 copies/mL were associated with greater survival (odds ratio, 2.83; 95% confidence interval, 1.07-7.53; P = .04) and a better clinical response (odds ratio, 6.38; 95% confidence interval, 1.68-24.19; P = .006).


CONCLUSIONS
AIDS-KS tumor responses after ART initiation were limited. Pretreatment plasma HHV-8 DNA level may be a surrogate for KS disease that is in need of intensive clinical management.
Evaluating the effectiveness of the abilities-focused approach to morning care of people with dementia.

BACKGROUND AND PURPOSE
The abilities-focused approach demonstrated efficacy in promoting engagement of residents with dementia in care. The extent to which these resident outcomes can be replicated when the abilities-focused approach is implemented by nursing staff under the conditions of day-to-day practice was investigated in this study. The aim was to examine changes in resident outcomes before and after nursing staff' implementation of the abilities-focused approach and the contribution of this approach to resident outcomes.


METHODS
A one-group pretest-post-test design was used. Observational data were obtained from 65 residents with dementia. The data pertained to the implementation of abilities-focused strategies during episodes of morning care and residents' level of agitation, participation in morning care and physical and psychosocial functioning.


RESULTS
The number of abilities-focused strategies used during morning care increased at post-test. No clinically important changes in resident outcomes were observed over time. However, the implementation of some strategies was associated with residents' participation in care and functioning at post-test. The results provided preliminary evidence of the effectiveness of the abilities-focused approach in maintaining functioning in people with dementia. Additional research is needed to understand the mechanism underlying the effects of this person-centred approach to care on resident outcomes.


IMPLICATIONS FOR PRACTICE
Implementation of the abilities-focused approach assists people with dementia to participate in morning care.
Clustering speakers by their voices

The problem of clustering speakers by their voices is addressed. With the mushrooming of available speech data from television broadcasts to voice mail, automatic systems for archive retrieval, organizing and labeling by speaker are necessary. Clustering conversations by speaker is a solution to all three of the above tasks. Another application for speaker clustering is to group utterances together for speaker adaptation in speech recognition. Metrics based on purity and completeness of clusters are introduced. Next our approach to speaker clustering is described and finally experimental results on a subset of the Switchboard corpus are presented.
Parotid metastasis of an amelanotic melanoma of the scalp: The great masquerader.

BACKGROUND
Cutaneous melanoma is often characterized by its pigmented appearance; however, up to 8.1% of such lesions contain little or no pigmentation. Amelanotic melanomas, lesions devoid of visible pigment, present a diagnostic quandary because they can masquerade as many other skin pathologies. Recognizing amelanotic melanoma is even more clinically challenging when it is first detected as a metastasis to the secondary tissue.


METHODS
We report a rare case of metastasis of an amelanotic melanoma to the parotid gland.


RESULTS
A 75-year-old man presented with an 8-month history of a painless, mobile, hardened mass in the right parotid region. Histopathological analysis of a fine-needle aspiration biopsy of the parotid mass indicated that the mass was melanoma. Careful clinical and radiological examination revealed an 8 mm erythematous papule in the right temporal scalp, initially diagnosed by visual examination as basal cell carcinoma. After right superficial parotidectomy, neck dissection, and excision of the temporal scalp lesion, histological examination revealed the scalp lesion to be amelanotic melanoma.


CONCLUSION
Although metastatic amelanotic melanoma to the parotid gland is a rare diagnosis, the clinician should be familiar with this presentation to increase the likelihood of making the correct diagnosis and delivering prompt treatment.
Gastroenterological surgery in Japan: The past, the present and the future

In the last two centuries, there has been remarkable progress in the field of gastroenterological surgery, including the curative resection of cancers, replacement of failed organs through transplantation, increased safety of undergoing major surgeries and decreased operative morbidity through developments in minimal access surgery. Japan has very much been at the forefront of these advances, as is evident from the present review, from advancing the surgical management of gastric cancer to the pioneering work in live-donor transplantation. This review also highlights many instances where surgical management of the same pathologies has evolved differently between Japan and the West. It is encouraging that many procedures established in Japan are eventually taken up by the West, often after rigorous assessment affirming the quality and applicability of such techniques. In Japan, many of the crucial issues in gastroenterological surgery are increasingly addressed through large multi-institutional prospective control trials, ensuring that Japanese surgeons continue to contribute to the advances in gastroenterological surgery.
Cloud data modelling employing a unified, non-redundant triangular mesh

This paper describes an application of error-based triangulation to very large sets of three-dimensional (3D) data. The algorithm is suitable for processing data collected by machine vision systems, co-ordinate measuring machines or laser-based range sensors. The algorithm models the large data sets, termed cloud data, using a uni®ed, non-redundant triangular mesh. This is accomplished from the 3D data points in two steps. Firstly, an initial data thinning is performed, to reduce the copious data set size, employing 3D spatial ®ltering. Secondly, the triangulation commences utilising a set of heuristic rules, from a user de®ned seed point. The triangulation algorithm interrogates the local geometric and topological information inherent in the cloud data points. The spatial ®ltering parameters are extracted from the cloud data set, by a series of local surface patches, and the required spatial error between the ®nal triangulation and the cloud data. Two procedures are subsequently employed to enhance the mesh: (i) the edges of mesh triangles are adjusted to produce a mesh containing approximately equilateral triangles; and (ii) mesh edges are aligned with the boundaries present on the object to minimise smoothing of naturally occurring features. Case studies are presented that illustrate the ef®cacy of the technique for rapidly constructing a geometric model from 3D digitised data. q 2001 Published by Elsevier Science Ltd.
Isolated Handwritten Kannada and Tamil Numeral Recognition: A Novel Approach

Handwritten character recognition has received extensive attention in academic and production fields. The recognition system can be either online or off-line. There is a large demand for Optical character recognition on hand written documents. India is a multi-lingual country and multi script country, where eighteen official scripts are accepted and have over hundred regional languages. In this paper we have proposed the projection distance metric and zoning based scheme for numeral recognition. We tested our proposed method for Kannada and Tamil numerals. A nearest neighbor classifier is used for subsequent purpose. The proposed method gives around 93% and 90% of recognition accuracy for Kannada and Tamil numerals respectively.
The fracture toughness of bulk metallic glasses

Metals and alloys with glassy, i.e., amorphous, structures are very strong. But like ceramics, strong and hard materials may be brittle, and susceptible to fracture. Bulk metallic glasses are such quasibrittle materials, whose resistance to fracture when a crack is present (which we call toughness) needs to be improved, through advances in alloy design and processing. Stiffness, strength, and toughness are the three primary attributes of a material, in terms of its mechanical properties. Bulk metallic glasses (BMGs) are known to exhibit elastic moduli at a fraction lower than crystalline alloys and have extraordinary strength. However, the reported values of fracture toughness of BMGs are highly variable; some BMGs such as the Zr-based ones have toughness values that are comparable to some high strength steels and titanium alloys, whereas there are also BMGs that are almost as brittle as silicate glasses. Invariably, monolithic BMGs exhibit no or low crack growth resistance and tend to become brittle upon structural relaxation. Despite its critical importance for the use of BMGs as structural materials, the fracture toughness of BMGs is relatively poorly understood. In this paper, we review the available literature to summarize the current understanding of the mechanics and micromechanisms of BMG toughness and highlight the needs for future research in this important area.
Outcomes of singleton and twin pregnancies complicated by pre-existing diabetes and gestational diabetes: A population-based study in Alberta, Canada, 2005-11.

BACKGROUND
We assessed the prevalence and pregnancy outcomes of pre-existing diabetes mellitus (pre-DM) and gestational diabetes mellitus (GDM) in Alberta, Canada, 2005-11.


METHODS
327 198 singleton and 5552 twin pregnancies resulting in live births or stillbirths were included. The odds ratios of adverse outcomes were evaluated comparing pre-DM with no diabetes and GDM with no diabetes, controlling for maternal characteristics.


RESULTS
Diabetes complicated 6.3% of pregnancies, with 88% being GDM. In singleton pregnancies, pre-DM and GDM were associated with increased risks of pre-eclampsia (adjusted odds ratio [aOR] = 3.38 and 1.83, respectively), cesarean delivery (aOR 2.53, 1.55), spontaneous preterm (aOR 4.20, 1.71), and labor-induced preterm (aOR 3.82, 2.00) in the mother, and macrosomia (aOR 2.11, 1.30), shoulder dystocia (aOR 1.54, 1.32), congenital anomalies (aOR 1.61, 1.20), and neonatal intensive care unit (NICU) admissions (aOR 3.81, 1.60) in the infants. In addition, pre-DM was associated with an increased likelihood of stillbirth (aOR 3.73) and neonatal death (aOR 2.00) compared with non-diabetic pregnancies. In twin pregnancies, pre-DM was associated with increased risks of spontaneous (aOR 3.54) and labor-induced (aOR 3.57) preterm births, large for gestational age (LGA) infants (aOR 3.73), congenital anomalies (aOR 3.05) and NICU admissions (aOR 2.91); GDM was associated with an increased risk of pre-eclampsia (aOR 1.54), cesarean delivery (aOR 1.57), and LGA infants (aOR 1.63).


CONCLUSIONS
Pre-existing diabetes confers higher risks than GDM. Diabetes is associated with adverse outcomes in singleton and twin pregnancies, and the increased risks are generally similar or less in twins, probably due to their higher "baseline" risks and closer clinical monitoring.
Predicting Heart Failure With Preserved and Reduced Ejection Fraction: The International Collaboration on Heart Failure Subtypes.

BACKGROUND
Heart failure (HF) is a prevalent and deadly disease, and preventive strategies focused on at-risk individuals are needed. Current HF prediction models have not examined HF subtypes. We sought to develop and validate risk prediction models for HF with preserved and reduced ejection fraction (HFpEF, HFrEF).


METHODS AND RESULTS
Of 28,820 participants from 4 community-based cohorts, 982 developed incident HFpEF and 909 HFrEF during a median follow-up of 12 years. Three cohorts were combined, and a 2:1 random split was used for derivation and internal validation, with the fourth cohort as external validation. Models accounted for multiple competing risks (death, other HF subtype, and unclassified HF). The HFpEF-specific model included age, sex, systolic blood pressure, body mass index, antihypertensive treatment, and previous myocardial infarction; it had good discrimination in derivation (c-statistic 0.80; 95% confidence interval [CI], 0.78-0.82) and validation samples (internal: 0.79; 95% CI, 0.77-0.82 and external: 0.76; 95% CI: 0.71-0.80). The HFrEF-specific model additionally included smoking, left ventricular hypertrophy, left bundle branch block, and diabetes mellitus; it had good discrimination in derivation (c-statistic 0.82; 95% CI, 0.80-0.84) and validation samples (internal: 0.80; 95% CI, 0.78-0.83 and external: 0.76; 95% CI, 0.71-0.80). Age was more strongly associated with HFpEF, and male sex, left ventricular hypertrophy, bundle branch block, previous myocardial infarction, and smoking with HFrEF (P value for each comparison ≤0.02).


CONCLUSIONS
We describe and validate risk prediction models for HF subtypes and show good discrimination in a large sample. Some risk factors differed between HFpEF and HFrEF, supporting the notion of pathogenetic differences among HF subtypes.
Prompting the clinical care of non-insulin dependent (type II) diabetic patients in an inner city area: one model of community care.

OBJECTIVE
To evaluate the effectiveness and acceptability of centrally organised prompting for coordinating community care of non-insulin dependent diabetic patients.


DESIGN
Randomised single centre trial. Patients allocated to prompted care in the community or to continued attendance at hospital diabetic clinic (controls). Median follow up two years.


SETTING
Two hospital outpatient clinics, 38 general practices, and 11 optometrists in the catchment area of a district general hospital in Islington.


PATIENTS
181 patients attending hospital outpatient clinics.


NULL HYPOTHESIS
There is no difference in process of medical care measures and medical outcome between prompted community care and hospital clinic care.


RESULTS
14 hospital patients failed to receive a single review in the clinic as compared with three patients in the prompted group (chi 2 = 6.1, df = 1; p = 0.013). Follow up for retinal screening was better in prompted patients than in controls; two prompted patients defaulted as against 12 controls (chi 2 = 6.9, df = 1; p = 0.008). Three measures per patient yearly were more frequent in prompted patients: tests for albuminuria (median 3.0 v 2.3; p = 0.03), plasma glucose estimations (3.1 v 2.5; p = 0.003), and glycated haemoglobin estimations (2.4 v 0.9; p < 0.001). Continuity of care was better in the prompted group (3.2 v 2.2 reviews by each doctor seen; p < 0.001). The study ended with no significant differences between the groups in last recorded random plasma glucose concentration, glycated haemoglobin value, numbers admitted to hospital for a diabetes related reason, and number of deaths. Questionnaires revealed a high level of patient, general practitioner, and optometrist satisfaction.


CONCLUSIONS
Six monthly prompting of non-insulin treated diabetic patients for care by inner city general practitioners and by optometrists is effective and acceptable.
Matrix metalloproteinases and tissue inhibitors of metalloproteinases in patients with different types of scars and keloids.

BACKGROUND
Hypertrophic scars and keloids are fibroproliferative skin disorders characterised by progressive deposition of collagen. Our study is designed to investigate the expression and concentration of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in different types of scars and keloids.


METHODS
Total RNA from 19 proliferative hypertrophic scar samples of patients with extended burns (total body surface area (TBSA): 21+/-12%), 18 mature hypertrophic scar samples from patients after elective surgery, 14 keloid samples and 18 normotrophic scar samples was, respectively, extracted, and then mRNA was isolated. Besides, biopsies were obtained from non-scarred skin of the patients and extraction of total RNA performed. Relative mRNA expression of MMP 2, MMP 9, TIMP 1 and TIMP 2 was measured with reverse transcriptase polymerase chain reaction (RT-PCR). Serum concentrations of MMP-1, -2, -9, TIMP-1, and -2 were determined using an enzyme-linked immunosorbent assay (ELISA).


RESULTS
Patients with extended hypertrophic scars after burn trauma presented a significantly higher TIMP-1 concentration (p<0.05) in their sera than the other patients. The relative expression of MMP 2 was significantly higher in samples of proliferative hypertrophic scars after burn injury. The relative expression of TIMP 1 and TIMP 2 was significantly higher in scar tissue of patients with proliferative and mature hypertrophic scars and keloids than in their regular skin and in scar samples of patients with normotrophic scars. The expression of TIMP 1 was significantly higher in samples of patients with keloids than in patients with hypertrophic scars.


CONCLUSIONS
The concentration of TIMP-1 in sera of patients varies depending on the size of the involved fibrotic scar tissue. A decrease in MMP-to-TIMP expression in scar tissue may contribute to increased synthesis and deposition of collagen, leading to a severe fibrotic reaction with pathologic scar formation. The results implicate non-operative therapy options in these patients that not only down-regulate TIMPs but also increase the activity of MMPs.
Aortic Hemodynamics and Arterial Stiffness Responses to Muscle Metaboreflex Activation With Concurrent Cold Pressor Test.

BACKGROUND
Overweight/obese young men have increased sympatho-excitation to cold and pain stress-induced by the cold pressor test (CPT) that may lead to abnormal hemodynamic responses. Concurrent CPT and exercise may augment the sympathetic-induced increases in aortic blood pressure (BP), pressure wave reflection (augmentation index, AIx), and arterial stiffness (pulse wave velocity, PWV). Since obesity is related with hypertension and sympathetic activity, we evaluated the aortic hemodynamic and PWV responses to muscle metaboreflex activation imposed by postexercise muscle ischemia (PEMI) concurrent with CPT in overweight/obese men.


METHODS
In 16 healthy (body mass index >25 and <40kg/m(2)) men (24±2 years), heart rate (HR), brachial BP, aortic BP, augmented pressure (AP), AIx, AIx adjusted to 75 beats/min (AIx@75), reflection time (Tr), first (P1) and second systolic peak (P2, wave reflection magnitude), and PWV (brachial-ankle PWV, baPWV) were evaluated at baseline, during isometric-handgrip exercise (IHG), and PEMI with (PEMI + CPT) and without CPT.


RESULTS
During IHG, brachial BP, aortic BP, AP, AIx, AIx@75, P1, and P2 increased ( P < 0.01) while Tr decreased ( P < 0.05) compared with baseline. During PEMI, all hemodynamic parameters remained elevated ( P < 0.05) and baPWV increased (P < 0.05) while Tr and HR returned to baseline. Compared with PEMI, the increases in HR, brachial BP, aortic BP, AIx@75, P1, P2, and baPWV were greater ( P < 0.05) during PEMI + CPT. During PEMI + CPT, Tr remained lower ( P < 0.05) than baseline.


CONCLUSIONS
Cold exposure with concurrent metaboreflex activation induces a significant increase in aortic hemodynamics and arterial stiffness, which may explain the high risk of adverse cardiovascular events during physiological stress.


CLINICAL TRIALS REGISTRATION
Trial Number NCT02104375.
Mortality of heart failure patients after cardiac resynchronization therapy: identification of predictors.

INTRODUCTION
A direct comparison of survival benefits between cardiac resynchronization therapy-pacemaker (CRT-P) and defibrillator (CRT-D) was not yet performed, leaving clinicians to question whether CRT-P alone is enough to protect congestive heart failure (CHF) patients from sudden cardiac death and whether CRT-D should be implanted to all CHF patients indicated for biventricular pacing. This study attempts to make this type of comparison in a large CHF population and seeks to identify predictors of death in patients with different comorbidities.


METHODS AND RESULTS
Study population consisted of 542 consecutive patients who were implanted with either CRT-P (N = 147) or CRT-D (N = 395) between 1999 and 2005. Patients' clinical and follow-up data were entered in a prospective registry and retrieved for analysis. The primary endpoint of this study was all-cause mortality during follow-up. Total all-cause mortality was significantly lower among patients with CRT-D (18.5% vs. 38.8% of CRT-P, chi(2)= 25.11, P < 0.001). Patients with one of three comorbidities--chronic renal failure (OR = 4.885, P = 0.005), diabetes mellitus (OR = 4.130, P = 0.003), and history of atrial fibrillation (OR = 1.473, P = 0.036)--appeared to have higher risk of death, while treatment with beta-blocker (OR = 0.330, P = 0.002) or CRT-D device (OR = 0.334, P = 0.003) seemed to be associated with lower mortality.


CONCLUSIONS
Data from this nonrandomized study indicate that CRT-D has additional survival benefits over CRT-P. Given these findings, CRT-D should be recommended to most CHF patients with indications for biventricular pacing. After CRT implant, chronic renal failure, diabetes mellitus, and history of atrial fibrillation are strong independent predictors of death.