Background: Radiofrequency ablation is a minimally-invasive treatment method that aims to destroy undesired tissue by exposing it to alternating current in the 100 kHz-800 kHz frequency range and ...heating it until it is destroyed via coagulative necrosis. Ablation treatment is gaining momentum especially in cancer research, where the undesired tissue is a malignant tumor. While ablating the tumor with an electrode or catheter is an easy task, real-time monitoring the ablation process is a must in order to maintain the reliability of the treatment. Common methods for this monitoring task have proven to be accurate, however, they are all time-consuming or require expensive equipment, which makes the clinical ablation process more cumbersome and expensive due to the time-dependent nature of the clinical procedure.
Methods: A machine learning (ML) approach is presented that aims to reduce the monitoring time while keeping the accuracy of the conventional methods. Two different hardware setups are used to perform the ablation and collect impedance data at the same time and different ML algorithms are tested to predict the ablation depth in 3 dimensions, based on the collected data.
Results: Both the random forest and adaptive boosting (adaboost) models had over 98% R
2
on the data collected with the embedded system-based hardware instrumentation setup, outperforming Neural Network-based models.
Conclusions: It is shown that an optimal pair of hardware setup and ML algorithm (Adaboost) is able to control the ablation by estimating the lesion depth within a test average of 0.3mm while keeping the estimation time within 10ms on a ×86-64 workstation.
Soil nailing has been widely used in many places in the world in the last two decades because of its technical and economical advantages. The nail–soil interface shear strength is an important ...parameter in soil nail design. This parameter is governed by a number of factors, among which the influence of the overburden pressure (or soil depth) is the most controversial. There are differing views concerning the effect of overburden on the nail–soil interface shear strength. In order to examine the influence of the overburden pressure, a series of laboratory pullout tests on soil nails installed in compacted completely decomposed granite fill have been conducted using two pullout boxes. Numerical simulations have also been carried out and the results are compared with the pullout test data. The procedures of the pullout tests and new features of the pullout boxes used are briefly described. Changes of the vertical stress in soil close to the nail throughout the course of soil nail installation and pullout are presented and discussed in detail. It is observed from the results of this study that the installation process of soil nail induced significant vertical stress changes in soil around the soil nails, and that the soil nail pullout shear resistance is independent of the overburden pressure (or soil depth).
The nail-soil interface shear strength is a key parameter in the design and stability assessment of soil nailing systems. A number of factors will influence the nail-soil interface shear strength. ...Among these factors, the degree of saturation (S
r
) of the soil is an important one especially for permanent soil nail structures. To study the influence of S
r
on soil nail pull-out shear resistance, a series of laboratory pull-out tests have been conducted on soil nails in compacted completely decomposed granite (CDG) fill prepared to different S
r
. The tests were conducted using two specially designed pull-out boxes (with same specifications). In the near-saturated tests, a high S
r
(about 98%) was achieved using two special features of the apparatus: a waterproof front cap and back-water pressure pipes at the bottom of the pull-out box. Test results showed that the nail-soil shearing plane migrated outwards into the soil when the S
r
of the soil increased. Also, peak pull-out strengths of soil nails were strongly influenced by the S
r
of the soil. Among the tested S
r
, the highest values of peak pull-out shear strength were obtained at S
r
values between 50% and 75%.
We evaluated the impact of the Oncotype DX assay on adjuvant treatment decisions for Chinese patients with breast cancer in Hong Kong. A comparison of pre-assay and post-assay recommendations ...demonstrated use of the information for treatment recommendations, resulting in a 27% decrease in chemotherapy usage. In approximately 30% of cases, physicians in the multidisciplinary committee agree/strongly agree that the assay influenced their decision.
The Oncotype DX Breast Cancer Assay is validated to assess risk of distant recurrence and likelihood of chemotherapy (CT) benefit in estrogen receptor-positive ESBC in various populations. In Hong Kong, > 80% of breast cancers are early stage breast cancer (ESBC) and > 60% of these women receive CT. This prospective study measured changes in CT type and recommendations, as well as physician impression of assay impact in a homogenous Chinese population.
Consecutive patients with estrogen receptor-positive, T1-3 N0-1mi M0 ESBC were offered enrollment. After surgery, physicians discussed treatment options with patients, then ordered the assay, then reassessed treatment recommendation considering assay results. Changes in treatment recommendation, CT utilization, physician confidence, and physician rating of influence on their treatment recommendations were measured.
A total of 146 evaluable patients received pre- and post-testing treatment recommendations. CT recommendations (including changes in intensity of CT) were changed for 34 of 146 patients (23.3%; 95% confidence interval, 16.7%-31.0%); change in intensity occurred in 7 of 146 (4.8%). There were 27 changes in treatment recommendations of adding or removing CT altogether (18.5% change; 95% confidence interval, 12.6%-25.8%). CT recommendations decreased from 52.1% to 37.7%, a net absolute reduction of 14.4% (P < .001; 27.6% net relative reduction). Pre-assay, 96% of physicians agreed/strongly agreed that they were confident in their treatment recommendation; post-assay, 90% of physicians agreed/strongly agreed with the same statement. Thirty percent of physicians agreed/strongly agreed that the test had influenced their recommendation, similar to the proportion of changed recommendations.
The Oncotype DX Assay appears to influence physician ESBC adjuvant treatment recommendations in Hong Kong.
The investigation of multiple sources in household water management is considered overly complicated and time consuming using paper and pen interviewing (PAPI). We assess the advantages of ...computer-assisted personal interviewing (CAPI) in Pacific Island Countries (PICs). We adapted an existing PAPI survey on multiple water sources and expanded it to incorporate location of water use and the impacts of extreme weather events using SurveyCTO on Android tablets. We then compared the efficiency and accuracy of data collection using the PAPI version (n = 44) with the CAPI version (n = 291), including interview duration, error rate and trends in interview duration with enumerator experience. CAPI surveys facilitated high-quality data collection and were an average of 15.2 min faster than PAPI. CAPI survey duration decreased by 0.55% per survey delivered (p < 0.0001), whilst embedded skip patterns and answer lists lowered data entry error rates, relative to PAPI (p < 0.0001). Large-scale household surveys commonly used in global monitoring and evaluation do not differentiate multiple water sources and uses. CAPI equips water researchers with a quick and reliable tool to address these knowledge gaps and advance our understanding of development research priorities.
Global water research and monitoring typically focus on the household's “main source of drinking‐water.” Use of multiple water sources to meet daily household needs has been noted in many developing ...countries but rarely quantified or reported in detail. We gathered self‐reported data using a cross‐sectional survey of 405 households in eight communities of the Republic of the Marshall Islands (RMI) and five Solomon Islands (SI) communities. Over 90% of households used multiple sources, with differences in sources and uses between wet and dry seasons. Most RMI households had large rainwater tanks and rationed stored rainwater for drinking throughout the dry season, whereas most SI households collected rainwater in small pots, precluding storage across seasons. Use of a source for cooking was strongly positively correlated with use for drinking, whereas use for cooking was negatively correlated or uncorrelated with nonconsumptive uses (e.g., bathing). Dry season water uses implied greater risk of water‐borne disease, with fewer (frequently zero) handwashing sources reported and more unimproved sources consumed. Use of multiple sources is fundamental to household water management and feasible to monitor using electronic survey tools. We contend that recognizing multiple water sources can greatly improve understanding of household‐level and community‐level climate change resilience, that use of multiple sources confounds health impact studies of water interventions, and that incorporating multiple sources into water supply interventions can yield heretofore‐unrealized benefits. We propose that failure to consider multiple sources undermines the design and effectiveness of global water monitoring, data interpretation, implementation, policy, and research.
Key Points
Household use of multiple water sources occurs in many countries but very few studies examine the practice in detail
>90% of households in Pacific Islands study sites used two or more water sources for daily needs and most reported changes by season
Neglecting multiple household water sources undermines global water monitoring, data interpretation, implementation, policy, and research
The Swan River estuary, Western Australia, has undergone substantial hydrological modifications since pre-European settlement. Land clearing has increased discharge from some major tributaries ...roughly 5-fold, while weirs and reservoirs for water supply have mitigated this increase and reduced the duration of discharge to the estuary. Nutrient loads have increased disproportionately with flow and are now approximately 20-times higher than pre-European levels. We explore the individual and collective impacts of these hydrological changes on the Swan River estuary using a coupled hydrodynamic-ecological numerical model. The simulation results indicate that despite increased hydraulic flushing and reduced residence times, increases in nutrient loads are the dominant perturbation, producing increases in the incidence and peak biomass of blooms of both estuarine and freshwater phytoplankton. Changes in salinity associated with altered seasonal freshwater discharge have a limited impact on phytoplankton dynamics.
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