Carbon and titanium diboride (TiB2) multilayer coatings.

Titanium Diboride, (TiB2) is a metal-based refractory ceramic material that has been investigated in industrial applications ranging from, cutting tools to wear parts and for use in the aerospace industry. The unique properties which make this material so fascinating are, its high hardness, high melting point and its corrosion resistance. TiB2 is prevented from wider mainstream use because of its inherent brittle nature. With a view to overcome this in coating form and with the aim of providing in addition inherent lubricity, in this study 50 layer TiB2/C multilayer stacks have been fabricated, with varying volume fractions of ceramic, whereby the interfaces of the layers limit crack propagation in the TiB2 ceramic. TiB2 has been multilayered with carbon, to make use of the unique and hybrid nature of the bonding in carbon coatings. DC magnetron sputtering with substrate bias was the preferred route for the fabrication of these coatings. AISI tool steel has been used as the substrate material. By varying the amount of TiB2 ceramic from 50% to 95%, the Hardness of the coating is seen to increase from 5 GPa to 17GPa. The Hardness is observed to decrease as a function of increasing carbon content, agreeing with other studies that the carbon layers are not load-bearing. The graphitic nature of the sp2 bond, however, acts as a lubricant layer

Addressing the Challenges of Semantic Citizen-Sensing

Preprin

Reduced transmission of IHHNV to Penaeus monodon from shrimp pond wastewater filtered through a polychaete-assisted sand filter (PASF) system

A polychaete-assisted sand filter (PASF) can aid water recirculation systems for shrimp culture ponds by removing large amounts of nutrients and suspended solids and chemically treating wastewater. By ingesting and degrading organic matter, Perinereis helleri polychaetes reared in a PASF can accumulate and potentially remove infectious hypodermal and haemopoietic necrosis virus (IHHNV) present in wastewater from ponds rearing virus-infected Penaeus monodon shrimp. Reported here are data showing that filtering pond wastewater through a PASF reduces its potential to transmit IHHNV. The trial employed 3 groups of 4 tanks each containing 20 P. monodon randomly selected from a pond in which IHHNV was evident at moderate prevalence and low loads (IHHNV low-load Pond 2). Over a 2 week period, each tank group was supplied with wastewater from either the same pond (Pond 2) or Pond 1 in which IHHNV was 100% prevalent at ~104-fold higher infection loads, either directly or after being filtered through a PASF. IHHNV real-time qPCR data on total nucleic acid (TNA) extracted from pleopods of 35 P. monodon selected at random from each group identified an elevated IHHNV infection prevalence (91%) in shrimp tested from tanks supplied directly with wastewater from Pond 1. In comparison, IHHNV was detected at a much reduced prevalence and lower loads among shrimp from tanks supplied with wastewater from Pond 2 (33%) or from Pond 1 after it had been filtered through a PASF (31%). The IHHNV prevalence and load data indicate that a PASF can play a useful role in reducing the potential for shrimp pond wastewater to transmit IHHNV infection to naïve P. monodon

Bioinspired metal–polymer thin films with varying hydrophobic properties

Nanocomposites involve the inclusion of one material into the layers of another material at a nanoscale level. Inspired by nature, nanocomposites material systems offer functionalities over their bulk forms which in some cases have evolved over millions of years. Here, thin film coatings have been fabricated by PVD sputtering, comprising a soft PTFE phase which is combined with a hard metallic NiTi phase. A series of coatings with PTFE ranging from 10 to 75 vol% have been prepared, and their surface energies and microstructures investigated. The surface energy of the nanocomposite films changes with the PTFE content, falling in the range between PTFE and NiTi with water contact angles between 80° and 102° for a thin film with 25 and 75 vol% of PTFE, respectively. Here, both TEM and EDX reveal PTFE forming along NiTi column boundaries. Coatings with PTFE content greater than 50 vol% failed due to a build-up of intrinsic stress. The degree of hybridization between NiTi and PTFE was found to be dependent on the PTFE layer thickness. SEM analysis of this coating reveals PTFE at the surface embedded within the NiTi matrix

Intensity-modulated radiotherapy for prostate cancer

Radiation therapy (RT) is a curative treatment modality for localized prostate cancer. Over the past two decades, advances in technology and imaging have considerably changed RT in prostate cancer treatment. Treatment has evolved from 2-dimensional (2D) planning using X-ray fields based on pelvic bony landmarks to 3-dimensional (3D) conformal RT (CRT) which uses computed tomography (CT) based planning. Despite improvements with 3D-CRT, dose distributions often remained suboptimal with portions of the rectum and bladder receiving unacceptably high doses. In more recent years, intensity-modulated radiation therapy (IMRT) has become the standard of care to deliver external beam RT. IMRT uses multiple radiation beams of different shapes and intensities delivered from a wide range of angles to \u27paint\u27 the radiation dose onto the tumor. IMRT allows for a higher dose of radiation to be delivered to the prostate while reducing dose to surrounding organs. Multiple clinical trials have demonstrated improved cancer outcomes with dose escalation, but toxicities using 3D-CRT and escalated doses have been problematic. IMRT is a method to deliver dose escalated RT with more conformal dose distributions than 3D-CRT and has been associated with improved toxicity profiles. IMRT also appears to be the safest method to deliver hypofractionated RT and pelvic lymph node radiation. The purpose of this review is to summarize the technical aspects of IMRT planning and delivery, and to review the literature supporting the use of IMRT for prostate cancer

The Internet-Wide Impact of P2P Traffic Localization on ISP Profitability

We conduct a detailed simulation study to examine how localizing P2P traffic within network boundaries impacts the profitability of an ISP. A distinguishing aspect of our work is the focus on Internet-wide implications, i.e., how adoption of localization within an ISP affects both itself and other ISPs. Our simulations are based on detailed models that estimate inter-autonomous-system (AS) P2P traffic and inter-AS routing, localization models that predict the extent to which P2P traffic is reduced, and pricing models that predict the impact of changes in traffic on the profit of an ISP. We evaluate our models by using a large-scale crawl of BitTorrent containing over 138 million users sharing 2.75 million files. Our results show that the benefits of localization must not be taken for granted. Some of our key findings include: 1) residential ISPs can actually lose money when localization is employed, and some of them will not see increased profitability until other ISPs employ localization; 2) the reduction in costs due to localization will be limited for small ISPs and tends to grow only logarithmically with client population; and 3) some ISPs can better increase profitability through alternate strategies to localization by taking advantage of the business relationships they have with other ISP

Polychaetes (Perinereis helleri) reared in sand beds filtering nutrients from shrimp (Penaeus monodon) culture ponds can transiently carry IHHNV

A polychaete-assisted sand filter (PASF) system has been developed to help remove nutrients from aquaculture pond wastewater whilst also producing polychaetes that are highly prized as bait by recreational anglers and as a dietary supplement to improve the fecundity of shrimp broodstock. Whilst rearing polychaetes in PASF beds offers potential to reduce impacts of sourcing them from the wild, the use of wastewater from ponds rearing shrimp such as Penaeus monodon will present a biosecurity risk of viruses being transferred to, and potentially amplified in, the worms. To assess such risks for transmitting infectious hypodermal and haematopoietic necrosis virus (IHHNV), groups of 3 or 4 PASF beds seeded with sand worm (Perinereis helleri) juveniles were supplied with wastewater from ponds of P. monodon with either high-load or low-load IHHNV infections. TaqMan real-time qPCR identified low loads of IHHNV (≤878 IHHNV DNA copies 200 ng−1 TNA) in most worms from PASF beds supplied wastewater from the high-load pond. IHHNV was either not detected or detected at the qPCR test sensitivity limits in worms from beds supplied wastewater from the low-load pond. Purging harvested worms of their gut contents in clean filtered seawater for 2 days significantly reduced IHHNV loads. Reverting PASF beds to clean seawater for 8 weeks before harvest also significantly reduced worm loads of IHHNV. Daily additions of a commercial probiotic to the sand bed surface for 4 weeks prior to clean seawater application provided no discernible benefit to IHHNV clearance. While clearly demonstrated to be capable of carrying IHHNV, the remediation measures examined suggest potential to ameliorate the infection transmission risks of P. helleri reared in PASF beds supplied with shrimp pond wastewater as a nutrient source

Feed Containing Novacq Improves Resilience of Black Tiger Shrimp, Penaeus Monodon, to Gill-associated Virus-induced Mortality

The ability of Novacq to improve resilience of black tiger shrimp, Penaeus monodon, to infection and mortality induced by gill-associated virus (GAV) was investigated. Over a 26-d period, shrimp were fed pellets with or without 10% Novacq. Following this, four replicate tanks, each containing 10 shrimp that had been fed either diet, were maintained as-is, injected with saline or injected with GAV inoculum (i.e., 40 shrimp for each of the six groups). For shrimp (n=20) in two of each group of four tanks, survival was monitored daily over 14d and a pleopod was sampled from each shrimp on Days 0 and 14. For the other two tanks, a pleopod was sampled from each shrimp on Days 0, 3, 7, 10, and 14 to track changes in GAV loads over time. Survival was significantly higher (P<0.05) from Day 7 onward among the group fed Novacq. GAV infection loads appeared to vary more between individuals in the Novacq diet cohort, but overall were not reduced significantly at any time points post-challenge compared to shrimp tested from the Control diet cohort.&nbsp

Using Authentic Medication Errors to Promote Pharmacy Student Critical Thinking and Active Learning

Objective: To promote first year (P1) pharmacy students’ awareness of medication error prevention and to support student learning in biomedical and pharmaceutical sciences. Innovation: A novel curricular activity was created and referred to as “Medication Errors and Sciences Applications (MESA)”. The MESA activity encouraged discussions of patient safety among students and faculty to link medication errors to biomedical and pharmaceutical sciences, which ultimately reinforced student learning in P1 curricular topics.   Critical Analysis: Three P1 cohorts implemented the MESA activity and approximately 75% of students from each cohort completed a reliable assessment instrument. Each P1 cohort had at least 14 student teams who generated professional reports analyzing authentic medication errors. The quantitative assessment results indicated that 70-85% of students believed that the MESA activity improved student learning in biomedical and pharmaceutical sciences. More than 95% of students agreed that the MESA activity introduced them to medication errors. Approximately 90% of students agreed that the MESA activity integrated the knowledge and skills they developed through the P1 curriculum, promoted active learning and critical thinking, and encouraged students to be self-directed learners. Furthermore, our data indicated that approximately 90% of students stated that the achievement of Bloom’s taxonomy's six learning objectives was promoted by completing the MESA activity. Next Steps: Pharmacy students’ awareness of medication errors is a critical component of pharmacy education, which pharmacy educators can integrate with biomedical and pharmaceutical sciences to enhance student learning in the P1 year. Treatment of Human Subjects: IRB exemption granted   Type: Not