35 research outputs found
Relative efficiency in the branch network of a Greek bank : a quantitative analysis
Measuring and evaluating the efficient use of resources of Bank branches
plays a decisive role in a Bank’s strategic planning. Usually, efficiency is
measured by using accounting ratios, such as labor productivity, capital
productivity, return on assets etc. When these ratios are properly used, they
provide significant information regarding the effective operation of the branch,
and contribute in carrying out intrabank comparisons and comparisons over a
period of time. However, by using such ratios, an important part of the branch
operation remains uncovered: the measurement of the effective use of the
resources. New mathematical programming models that are related with the
degree at which each branch makes use of its resources, are applied to deal with
the weaknesses of such ratios. This study discuss the limitations of using
accounting ratio analysis for assessing performance and, presents and interprets
the results from the application of mathematical programming models in a sample
of branches of a Greek Bank.peer-reviewe
Variable structure robot control systems: The RAPP approach
International audienceThis paper presents a method of designing variable structure control systems for robots. As the on-board robot computational resources are limited, but in some cases the demands imposed on the robot by the user are virtually limitless, the solution is to produce a variable structure system. The task dependent part has to be exchanged, however the task governs the activities of the robot. Thus not only exchange of some task-dependent modules is required, but also supervisory responsibilities have to be switched. Such control systems are necessary in the case of robot companions, where the owner of the robot may demand from it to provide many services.
20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years
The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment
Long-term outcomes for neoadjuvant versus adjuvant chemotherapy in early breast cancer: meta-analysis of individual patient data from ten randomised trials
Background
Neoadjuvant chemotherapy (NACT) for early breast cancer can make breast-conserving surgery more feasible and might be more likely to eradicate micrometastatic disease than might the same chemotherapy given after surgery. We investigated the long-term benefits and risks of NACT and the influence of tumour characteristics on outcome with a collaborative meta-analysis of individual patient data from relevant randomised trials.
Methods
We obtained information about prerandomisation tumour characteristics, clinical tumour response, surgery, recurrence, and mortality for 4756 women in ten randomised trials in early breast cancer that began before 2005 and compared NACT with the same chemotherapy given postoperatively. Primary outcomes were tumour response, extent of local therapy, local and distant recurrence, breast cancer death, and overall mortality. Analyses by intention-to-treat used standard regression (for response and frequency of breast-conserving therapy) and log-rank methods (for recurrence and mortality).
Findings
Patients entered the trials from 1983 to 2002 and median follow-up was 9 years (IQR 5–14), with the last follow-up in 2013. Most chemotherapy was anthracycline based (3838 [81%] of 4756 women). More than two thirds (1349 [69%] of 1947) of women allocated NACT had a complete or partial clinical response. Patients allocated NACT had an increased frequency of breast-conserving therapy (1504 [65%] of 2320 treated with NACT vs 1135 [49%] of 2318 treated with adjuvant chemotherapy). NACT was associated with more frequent local recurrence than was adjuvant chemotherapy: the 15 year local recurrence was 21·4% for NACT versus 15·9% for adjuvant chemotherapy (5·5% increase [95% CI 2·4–8·6]; rate ratio 1·37 [95% CI 1·17–1·61]; p=0·0001). No significant difference between NACT and adjuvant chemotherapy was noted for distant recurrence (15 year risk 38·2% for NACT vs 38·0% for adjuvant chemotherapy; rate ratio 1·02 [95% CI 0·92–1·14]; p=0·66), breast cancer mortality (34·4% vs 33·7%; 1·06 [0·95–1·18]; p=0·31), or death from any cause (40·9% vs 41·2%; 1·04 [0·94–1·15]; p=0·45).
Interpretation
Tumours downsized by NACT might have higher local recurrence after breast-conserving therapy than might tumours of the same dimensions in women who have not received NACT. Strategies to mitigate the increased local recurrence after breast-conserving therapy in tumours downsized by NACT should be considered—eg, careful tumour localisation, detailed pathological assessment, and appropriate radiotherapy
Wax-Printed Fluidic Controls for Delaying and Accelerating Fluid Transport on Paper-Based Analytical Devices
In this work, we explore a new method for controlling fluid transport rate on paper-based analytical devices that enables both the delay and the acceleration of fluid flow. The delays were incorporated by wax printing linear patterns of variable width within the flow channel and melted to penetrate the paper. In this manner, the surface tension of the fluid decreases while its contact angle increases, causing a pressure drop along the fluid path that reduces capillary flow. The acceleration of flow was accomplished by overlaying hydrophobic stripes (prepared by wax printing and melting the wax) on the hydrophilic path (top or top–bottom). In this manner, the fluid was repelled from two dimensions (vertical and applicate), increasing the flow rate. The combination of these methods on the same devices could adjust wicking time in intermediate time internals. The method enabled a wide timing of fluid transport, accomplishing a change in wicking times that extended from −41% to +259% compared to open paper channels. As a proof of concept, an enzymatic assay of glucose was used to demonstrate the utility of these fluid control methods in kinetic methods of analysis
Generic Assay of Sulfur-Containing Compounds Based on Kinetics Inhibition of Gold Nanoparticle Photochemical Growth
This
work describes a new, equipment-free, generic method for the
determination of sulfur-containing compounds that is based on their
ability to slow down the photoreduction kinetics of gold ions to gold
nanoparticles. The method involves tracking the time required for
a red coloration to appear in the tested sample, indicative of the
formation of gold nanoparticles, and compare the measured time relative
to a control sample in the absence of the target analyte. The method
is applicable with minimal and simple steps requiring only two solutions
(i.e., a buffer and a gold solution), a source of light (UV or visible),
and a timer. The method responds to a large variety of sulfur-containing
compounds including thiols, thioesters, disulfides, thiophosphates,
metal–sulfur bonds, and inorganic sulfur and was therefore
applied to the determination of a variety of compounds such as dithiocarbamate
and organophosphorous pesticides, biothiols, pharmaceutically active
compounds, and sulfides in different samples such as natural waters
and wastewater, biological fluids, and prescription drugs. The analytical
figures of merit of the method include satisfactory sensitivity (quantitation
limits at the low μM levels), good recoveries (from 93 to 109%),
and satisfactory reproducibility (from 4.8 to 9.8%). The method is
easily adoptable to both laboratory settings and nonlaboratory conditions
for quantitative and semiquantitative analysis, respectively, is user-friendly
even for the minimally trained user, and can be performed with limited
resources at low cost
Ultratrace Determination of Silver, Gold, and Iron Oxide Nanoparticles by Micelle Mediated Preconcentration/Selective Back-Extraction Coupled with Flow Injection Chemiluminescence Detection
A new method has been developed for
the ultrasensitive determination
of silver, gold, and iron oxide nanoparticles in environmental samples.
Cloud point extraction was optimized and used as a means to extract
and preconcentrate all nanoparticle species simultaneously from the
same sample. The extracted nanoparticles were sequentially isolated
from the surfactant-rich phase by a new selective back-extraction
procedure and dissociated into their precursor metal ions. Each ion
solution was injected in a flow injection analysis (FIA) manifold,
accommodating the chemiluminogenic oxidation of luminol, in order
to amplify chemiluminescence (CL) emission in a manner proportional
to its concentration. Under the optimum experimental conditions, the
detection limits were brought down to the picomolar and femtomolar
concentration levels with satisfactory analytical features in terms
of precision (2.0–13.0%), selectivity against dissolved ions,
and recoveries (74–114%). The method was successfully applied
to the determination of iron oxide, silver, and gold nanoparticles
in environmental samples of different complexity, ranging from unpolluted
river water to raw sewage. The developed method could also serve as
a basis for future deployment of molecular spectrometry detectors
for the selective determination and speciation analysis of nanoparticles
in environmental applications
Programming Fluid Transport in Paper-Based Microfluidic Devices Using Razor-Crafted Open Channels
Manipulating
fluid transport in microfluidic, paper-based analytical
devices (μPADs) is an essential prerequisite to enable multiple
timed analytical steps on the same device. Current methods to control
fluid distribution mainly rely on controlling how slowly the fluid
moves within a device or by activating an on/off switch to flow. In
this Article, we present an easy approach for programming fluid transport
within paper-based devices that enables both acceleration as well
as delay of fluid transport without active pumping. Both operations
are programmed by carving open channels either longitudinally or perpendicularly
to the flow path using a craft-cutting tool equipped with a knife
blade. Channels are crafted after μPADs fabrication enabling
the end user to generate patterns of open-channels on demand by carving
the porous material of the paper without cutting or removing the paper
substrate altogether. Parameters to control the acceleration or delay
of flow include the orientation, length, and number of open channels.
Using this method, accelerated as well as reduced fluid transport
rates were achieved on the same device. This methodology was applied
to μPADs for multiple and time-programmable assays for metal
ion determination