7,098 research outputs found
Rise in the price of wheat for the Bakery in the Street of the Fishmarket in the city of Lima 1812-1821
This article analyzes the information found in the newly discovered account book in the Lima National Archives on bulk wheat prices paid by a centrally located bakery for the nine year period 1812 to June 1821. The conclusion is that the price of wheat per bushel paid by this Lima bakery rose more than eleven hundred percent between 1812 and 1821 and that the profits shown after the bakery paid these increased wheat costs would indicate a rise in the price of bread to cover the increased cost of the wheat. Ships carrying wheat noted in the account book are listed
Retail Financial Advice: Does One Size Fit All?
Using unique data on Canadian households, we show that financial advisors exert substantial influence over their clients\u27 asset allocation, but provide limited customization. Advisor fixed effects explain considerably more variation in portfolio risk and home bias than a broad set of investor attributes that includes risk tolerance, age, investment horizon, and financial sophistication. Advisor effects remain important even when controlling flexibly for unobserved heterogeneity through investor fixed effects. An advisor\u27s own asset allocation strongly predicts the allocations chosen on clients\u27 behalf. This one‐size‐fits‐all advice does not come cheap: advised portfolios cost 2.5% per year, or 1.5% more than life cycle funds
Heavy Scalar Top Quark Decays in the Complex MSSM: A Full One-Loop Analysis
We evaluate all two-body decay modes of the heavy scalar top quark in the
Minimal Supersymmetric Standard Model with complex parameters (cMSSM) and no
generation mixing. The evaluation is based on a full one-loop calculation of
all decay channels, also including hard QED and QCD radiation. The
renormalization of the complex parameters is described in detail. The
dependence of the heavy scalar top quark decay on the relevant cMSSM parameters
is analyzed numerically, including also the decay to Higgs bosons and another
scalar quark or to a top quark and the lightest neutralino. We find sizable
contributions to many partial decay widths and branching ratios. They are
roughly of O(10%) of the tree-level results, but can go up to 30% or higher.
These contributions are important for the correct interpretation of scalar top
quark decays at the LHC and, if kinematically allowed, at the ILC. The
evaluation of the branching ratios of the heavy scalar top quark will be
implemented into the Fortran code FeynHiggs.Comment: 86 pages, 38 figures; minor changes, version published as Phys. Rev.
D86 (2012) 03501
Economic inequalities in burden of illness, diagnosis and treatment of five long-term conditions in England: panel study
We compared the distribution by wealth of self-reported illness burden (estimated from validated scales, biomarker and reported symptoms) for angina, cataract, depression, diabetes and osteoarthritis, with the distribution of self-reported medical diagnosis and treatment. We aimed to determine if the greater illness burden borne by poorer participants was matched by appropriately higher levels of diagnosis and treatment
Self-reported quality of care for older adults from 2004 to 2011: a cohort study
Background: little is known about changes in the quality of medical care for older adults over time. Objective: to assess changes in technical quality of care over 6 years, and associations with participants' characteristics. Design: a national cohort survey covering RAND Corporation-derived quality indicators (QIs) in face-to-face structured interviews in participants' households. Participants: a total of 5,114 people aged 50 or more in four waves of the English Longitudinal Study of Ageing. Methods: the percentage achievement of 24 QIs in 10 general medical and geriatric clinical conditions was calculated for each time point, and associations with participants' characteristics were estimated using logistic regression. Results: participants were eligible for 21,220 QIs. QI achievement for geriatric conditions (cataract, falls, osteoarthritis and osteoporosis) was 41% [95% confidence interval (CI): 38–44] in 2004–05 and 38% (36–39) in 2010–11. Achievement for general medical conditions (depression, diabetes mellitus, hypertension, ischaemic heart disease, pain and cerebrovascular disease) improved from 75% (73–77) in 2004–05 to 80% (79–82) in 2010–11. Achievement ranged from 89% for cerebrovascular disease to 34% for osteoarthritis. Overall achievement was lower for participants who were men, wealthier, infrequent alcohol drinkers, not obese and living alone. Conclusion: substantial system-level shortfalls in quality of care for geriatric conditions persisted over 6 years, with relatively small and inconsistent variations in quality by participants' characteristics. The relative lack of variation by participants' characteristics suggests that quality improvement interventions may be more effective when directed at healthcare delivery systems rather than individuals
Switchable LED-based laparoscopic multispectral system for rapid high-resolution perfusion imaging
SIGNIFICANCE: Multispectral imaging (MSI) is an approach for real-time, quantitative, and non-invasive tissue perfusion measurements. Current laparoscopic systems based on mosaic sensors or filter wheels lack high spatial resolution or acceptable frame rates.AIM: To develop a laparoscopic system for MSI-based color video and tissue perfusion imaging during gastrointestinal surgery without compromising spatial or temporal resolution.APPROACH: The system was built with 14 switchable light-emitting diodes in the visible and near-infrared spectral range, a 4K image sensor, and a 10 mm laparoscope. Illumination patterns were created for tissue oxygenation and hemoglobin content monitoring. The system was calibrated to a clinically approved laparoscopic hyperspectral system using linear regression models and evaluated in an occlusion study with 36 volunteers.RESULTS: The root mean squared errors between the MSI and reference system were 0.073 for hemoglobin content, 0.039 for oxygenation in deeper tissue layers, and 0.093 for superficial oxygenation. The spatial resolution at a working distance of 45 mm was 156 μm. The effective frame rate was 20 fps.CONCLUSIONS: High-resolution perfusion monitoring was successfully achieved. Hardware optimizations will increase the frame rate. Parameter optimizations through alternative illumination patterns, regression, or assumed tissue models are planned. Intraoperative measurements must confirm the suitability during surgery.</p
New path description for the M(k+1,2k+3) models and the dual Z_k graded parafermions
We present a new path description for the states of the non-unitary
M(k+1,2k+3) models. This description differs from the one induced by the
Forrester-Baxter solution, in terms of configuration sums, of their
restricted-solid-on-solid model. The proposed path representation is actually
very similar to the one underlying the unitary minimal models M(k+1,k+2), with
an analogous Fermi-gas interpretation. This interpretation leads to fermionic
expressions for the finitized M(k+1,2k+3) characters, whose infinite-length
limit represent new fermionic characters for the irreducible modules. The
M(k+1,2k+3) models are also shown to be related to the Z_k graded parafermions
via a (q to 1/q) duality transformation.Comment: 43 pages (minor typo corrected and minor rewording in the
introduction
Screening of COPD patients for abdominal aortic aneurysm
Purpose: Screening for abdominal aortic aneurysm (AAA) in “men aged over 65
years who have ever smoked” is a recommended policy. To reduce the number of
screenings, it may be of value to define subgroups with a higher prevalence of
AAA. Since chronic obstructive pulmonary disease (COPD) and AAA are associated
with several common risk factors, this study investigates the prevalence of
AAA in COPD patients. Patients and methods: Patients with COPD were identified
via the hospital information system. Inclusion criteria were: COPD stage I–IV,
ability to give full consent, and age >18 years; exclusion criteria were:
patient too obese for an ultrasound check, previously diagnosed AAA, prior
surgery for AAA, or ethical grounds such as concomitant advanced malignant or
end-stage disease. The primary endpoint of the study was an aortic diameter
measured by ultrasound of ≥30 mm. Defined secondary endpoints were evaluated
on the basis of medical records and interviews. Results: Of the 1,180
identified COPD patients, 589 were included in this prospective study. In 22
patients (3.70%), the aortic diameter was ≥30 mm, representing an AAA
prevalence of 6.72% among males aged >65 years. The risk of AAA increased with
the following comorbidities/risk factors: male sex (odds ratio [OR] 2.98),
coronary heart disease (OR 2.81), peripheral arterial occlusive disease (OR
2.47), hyperlipoproteinemia (OR 2.77), AAA in the family history (OR 3.95),
and COPD stage I/II versus IV (OR 1.81). Conclusion: The overall AAA
prevalence of 3.7% in our group of COPD patients is similar to that of the
general population aged >65 years. However, the frequency of AAA in male COPD
patients aged >65 years is considerably higher (6.72%) and increased further
still in those individuals with additional comorbidities/risk factors.
Defining subgroups with a higher risk of AAA may increase the efficiency of
screening
Singular Value Decomposition of Operators on Reproducing Kernel Hilbert Spaces
Reproducing kernel Hilbert spaces (RKHSs) play an important role in many
statistics and machine learning applications ranging from support vector
machines to Gaussian processes and kernel embeddings of distributions.
Operators acting on such spaces are, for instance, required to embed
conditional probability distributions in order to implement the kernel Bayes
rule and build sequential data models. It was recently shown that transfer
operators such as the Perron-Frobenius or Koopman operator can also be
approximated in a similar fashion using covariance and cross-covariance
operators and that eigenfunctions of these operators can be obtained by solving
associated matrix eigenvalue problems. The goal of this paper is to provide a
solid functional analytic foundation for the eigenvalue decomposition of RKHS
operators and to extend the approach to the singular value decomposition. The
results are illustrated with simple guiding examples
Treatment of tuberculosis in a region with high drug resistance: Outcomes, drug resistance amplification and re-infection
Introduction: Emerging antituberculosis drug resistance is a serious threat for tuberculosis (TB) control, especially in Eastern
European countries.
Methods: We combined drug susceptibility results and molecular strain typing data with treatment outcome reports to
assess the influence of drug resistance on TB treatment outcomes in a prospective cohort of patients from Abkhazia
(Georgia). Patients received individualized treatment regimens based on drug susceptibility testing (DST) results. Definitions
for antituberculosis drug resistance and treatment outcomes were in line with current WHO recommendations. First and
second line DST, and molecular typing were performed in a supranational laboratory for Mycobacterium tuberculosis (MTB)
strains from consecutive sputum smear-positive TB patients at baseline and during treatment.
Results: At baseline, MTB strains were fully drug-susceptible in 189/326 (58.0%) of patients. Resistance to at least H or R
(PDR-TB) and multidrug-resistance (MDR-TB) were found in 69/326 (21.2%) and 68/326 (20.9%) of strains, respectively. Three
MDR-TB strains were also extensively resistant (XDR-TB). During treatment, 3/189 (1.6%) fully susceptible patients at baseline
were re-infected with a MDR-TB strain and 2/58 (3.4%) PDR-TB patients became MDR-TB due to resistance amplification. 5/
47 (10.6%) MDR- patients became XDR-TB during treatment. Treatment success was observed in 161/189 (85.2%), 54/69
(78.3%) and 22/68 (32.3%) of patients with fully drug susceptible, PDR- and MDR-TB, respectively. Development of ofloxacin
resistance was significantly associated with a negative treatment outcome.
Conclusion: In Abkhazia, a region with high prevalence of drug resistant TB, the use of individualized MDR-TB treatment
regimens resulted in poor treatment outcomes and XDR-TB amplification. Nosocomial transmission of MDR-TB emphasizes
the importance of infection control in hospitals
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