bluuebunny/crossref_metadata_2025 huggingface dataset:
Poster – 12: Radiological assessment of the secondary barrier shielding for IMRT treatments delivered through patient inhomogeneities
Authors: Haseeb Syed Abdul , Ahmad Syed Bilal , Mirza Sikander Majid
Published: August 2016

Purpose:

To assess the impact of radiation treatment delivery through patient inhomogeneities on the secondary barrier shielding requirements in IMRT treatments using Monte Carlo Simulations.

Materials and Methods:

Scatter factors were calculated at a distance of 1m from the center of a virtual phantom in Geant4.10.01. Phantom (30×30×30 cm3) was inserted with lung (30×30×8 cm3), stainless steel (5×5×5 cm3) and aluminum (5×5×5 cm3) to represent the inhomogeneities. Scatter factor was defined according to the NCRP‐151 recommendations and was calculated for angles of 3° to 120° with respect to the beam's central axis. A virtual radiation source, with energy sampled from a histogram representing 6 MV FFF beam, was used for irradiation with a field size of 15×15 cm2 and SSD of 100 cm.

Results:

Irradiation through the inhomogeneity affects the patient scattered dose. For high Z material inhomogeneities the scattered dose is reduced due to significant attenuation of the primary radiation. On the other hand if the inhomogeneity is a low Z material such as lung the scattered dose is higher by a maximum of 26%. The average increase in scatter factors for the lung phantom was 17% for angles between 3° and 63° compared to the homogeneous water phantom.

Conclusions:

In IMRT type treatments delivered through low density patient inhomogeneities (lung) the scattered dose increases significantly. Considering a large proportion of patients receiving radiation therapy for lung cancers the increase in the scattered dose should be incorporated in the shielding calculations for the secondary barriers.
Poster ‐ 21: Verification of Monitor Unit Calculations for Breast Field‐In‐Field Three‐Dimensional Conformal Radiotherapy Plans
Authors: Kosztyla Robert , Pierce Greg , Ploquin Nicolas , Roumeliotis Michael , Schinkel Colleen
Published: August 2016

Purpose:

To determine the source of systematic monitor unit (MU) calculation discrepancies between RadCalc and Eclipse treatment planning software for three‐dimensional conformal radiotherapy field‐in‐field breast treatments.

Methods:

Data were reviewed for 28 patients treated with a field‐in‐field breast technique with MU calculations from RadCalc that were larger than MU calculations from Eclipse for at least one field. The distance of the calculation point from the jaws was measured in each field's beam's‐eye‐view and compared with the percentage difference in MU (%ΔMU) between RadCalc and Eclipse. 10×10, 17×13 and 20×20 cm2 beam profiles were measured using the Profiler 2 diode array for 6‐MV photon beams and compared with profiles calculated with Eclipse and RadCalc using a gamma analysis (3%, 3 mm).

Results:

The mean %ΔMU was 1.3%±0.3%. There was a statistically‐significant correlation between %ΔMU and the distance of the calculation point from the Y jaw (r=−0.43, p<0.001). RadCalc profiles differed from measured profiles, especially near the jaws. The gamma pass rate for 6‐MV fields of 17×13 cm2 field size was 95%±1% for Eclipse‐generated profiles and 53%±20% for RadCalc‐generated profiles (p=0.01).

Conclusions:

Calculations using RadCalc for field‐in‐field breast plans resulted in MUs that were larger than expected from previous clinical experience with wedged plans with calculation points far from the jaws due to the position of the calculation point near the jaws in the beam's‐eye‐view of each field.
Poster ‐ 24: Characterization of the energy dependence of high‐sensitivity MCP‐N TLD and Al2O3:C OSLD in‐vivo dosimetry systems for 40–100 kVp energies
Authors: Poirier Yannick , Kuznetsova Svetlana , Barajas Eduardo Villarreal
Published: August 2016

Purpose:

To characterize the energy dependence of high‐sensitivity MCP‐N TLD and Al2O3:C OSLD dosimetry systems at low (40–100 kVp) energies for in‐vivo dosimetry.

Methods:

We assessed the variation of response with energy of two detectors in the 40–100 kVp energy range: high‐sensitivity MCP‐N TLDs (LiF:Mg,Cu,P) and OSLDs (Al2O3:C).

The detectors were irradiated with an XRad 320ix biological irradiator under reference conditions. The delivered dose was 10 cGy for 7 beam qualities ranging from 40–100 kVp, 1.7–4.0 mm Al, and effective energies 26.9–37.9 keV.

Both sets of detectors were also irradiated under reference conditions at 6 MV using a Varian Clinac 21Ex to assess the change in response from high‐energy beams.

Results:

The MCP‐N high‐sensitivity TLDs were relatively insensitive to energies in the kV range, as their response varied by ±5%, i.e. well within the reproducibility limits of these detectors. However, the OSLDs exhibited a linearly‐decreasing response with energy with a response 18.7% higher at 40 kVp than at 100 kVp for the same nominal dose.

Compared to the 6 MV beams used in conventional radiotherapy, OSLDs responded 3.3–3.9 times higher depending on beam quality while the MCP‐N TLD response was unchanged within experimental uncertainty.

Conclusions:

Unlike the more commonly used TLD‐100, the high‐sensitivity MCP‐N TLDs exhibit little to no energy response. OSLDs are shown to be highly energy‐dependent, both from MV to kV and within the kV range.
Poster ‐ 25: Neutron Spectral Measurements around a Scanning Proton Beam
Authors: Kildea John , Enger Shirin , Maglieri Robert , Mirzakhanian Lalageh , Dahlgren Christina Vallhagen , Dubeau Jacques , Witharana Sanjeeva
Published: August 2016

We describe the measurements of neutron spectra that we undertook around a scanning proton beam at the Skandion proton therapy clinic in Uppsala, Sweden. Measurements were undertaken using an extended energy range Nested Neutron Spectrometer (NNS, Detec Inc., Gatineau, QC) operated in pulsed and current mode. Spectra were measured as a function of location in the treatment room and for various Bragg peak depths. Our preliminary unfolded data clearly show the direct, evaporation and thermal neutron peaks and we can show the effect on the neutron spectrum of a water phantom in the primary proton beam.
Poster ‐ 28: Shielding of X‐ray Rooms in Ontario in the Absence of Best Practice
Authors: Frimeth Jeff , Richer Jeff , Nesbitt James
Published: August 2016

This poster will be strictly based on the Healing Arts Radiation Protection (HARP) Act, Regulation 543 under this Act (X‐ray Safety Code), and personal communication the presenting author has had. In Ontario, the process of approval of an X‐ray machine installation by the Director of the X‐ray Inspection Service (XRIS) follows a certain protocol. Initially, the applicant submits a series of forms, including recommended shielding amounts, in order to satisfy the law. This documentation is then transferred to a third‐party vendor (i.e. a professional engineer – P. Eng.) outsourced by the Ministry of Health and Long‐term Care (MOHLTC). The P.Eng. then evaluates the submitted documentation for appropriate fulfillment of the HARP Act and Reg. 543 requirements. If the P.Eng.'s evaluation of the documentation is to their satisfaction, the XRIS is then notified. Finally, the Director will then issue a letter of approval to install the equipment at the facility. The methodology required to be used by the P.Eng. in order to determine the required amounts of protective barriers, and recommended to be used by the applicant, is contained within Safety Code 20A. However, Safety Code 35 has replaced the obsolete Safety Code 20A document and employs best practices in shielding design. This talk will focus further on specific intentions and limitations of Safety Code 20A. Furthermore, this talk will discuss the definition of the “practice of professional engineering” in Ontario. COMP members who are involved in shielding design are strongly encouraged to attend.
Poster ‐ 31: Predicting IQ and hearing loss following radiotherapy in pediatric brain tumors: proton vs photon
Authors: Fortin Dominique , Ng Angela , Tsang Derek , Sharpe Michael , Laperriere Norm , Hodgson David
Published: August 2016

Purpose:

The increased sparing of normal tissues in intensity modulated proton therapy (IMPT) in pediatric brain tumor treatments should translate into improved neurocognitive outcomes. Models were used to estimate the intelligence quotient (IQ) and the risk of hearing loss 5 years post radiotherapy and to compare outcomes of proton against photon in pediatric brain tumors.

Methods:

Patients who had received intensity modulated radiotherapy (IMRT) were randomly selected from our retrospective database. The existing planning CT and contours were used to generate IMPT plans. The RBE‐corrected dose was calculated for both IMPT and IMRT. For each patient, the IQ was estimated via a Monte Carlo technique, whereas the reported incidence of hearing loss as a function of cochlear dose was used to estimate the probability of occurrence.

Results:

The integrated brain dose was reduced in all IMPT plans, translating into a gain of 2 IQ points on average for protons for the whole cohort at 5 years post‐treatment. In terms of specific diseases, the gains in IQ ranged from 0.8 points for medulloblastoma, to 2.7 points for craniopharyngioma. Hearing loss probability was evaluated on a per‐ear‐basis and was found to be systematically less for proton versus photon: overall 2.9% versus 7.2%.

Conclusions:

A method was developed to predict IQ and hearing outcomes in pediatric brain tumor patients on a case‐by‐case basis. A modest gain was systematically observed for proton in all patients. Given the uncertainties within the model used and our reinterpretation, these gains may be underestimated.
Poster ‐ 33: Dosimetry Comparison of Prone Breast Forward and Inverse Treatment planning considering daily setup variations
Authors: Jiang Runqing , Zhan Lixin , Osei Ernest
Published: August 2016

Introduction:

The purpose of this study is to investigate the effects of daily setup variations on prone breast forward field‐in‐field (FinF) and inverse IMRT treatment planning.

Methods:

Rando Phantom (Left breast) and Pixy phantom (Right breast) were built and CT scanned in prone position. The treatment planning (TP) is performed in Eclipse TP system. Forward FinF plan and inverse IMRT plan were created to satisfy the CTV coverage and OARs criteria. The daily setup variations were assumed to be 5 mm at left‐right, superior‐inferior, and anterior‐posterior directions. The DVHs of CTV coverage and OARs were compared for both forward FinF plan and inverse IMRT plans due to 5mm setup variation.

Results and Discussions:

DVHs of CTV coverage had fewer variations for 5m setup variation for forward FinF and inverse IMRT plan for both phantoms. However, for the setup variations in the left‐right direction, the DVH of CTV coverage of IMRT plan showed the worst variation due to lateral setup variation for both phantoms. For anterior‐posterior variation, the CTV could not get full coverage when the breast chest wall is shallow; however, with the guidance of MV imaging, breast chest wall will be checked during the MV imaging setup. So the setup variations have more effects on inverse IMRT plan, compared to forward FinF plan, especially in the left‐right direction.

Conclusions:

The Forward FinF plan was recommended clinically considering daily setup variation.
Poster ‐ 35: Monitoring patient positioning during deep inspiration breath hold with a distance measuring laser
Authors: Weston Mark , Juhasz Janos
Published: August 2016

Purpose:

The accuracy of treatment delivery for left breast/chest wall patients using deep inspiration breath hold (DIBH) is being monitored using a distance measuring laser (DML)

Methods:

A commercially available DML (DLS‐C15, Dimetix) was mounted behind a Varian TrilogyTM linac. Relative to the machine isocenter, the laser from the beam was offset by 8 cm to the left and by 1 cm in the superior direction. This position was selected because this point is situated on the sternum for the majority of the left breast/chest‐wall patients treated at our institution.

The Varian Real‐Time Positioning Management™ (RPM) guided DIBH treatments at our institution is delivered by placing the system's tracking block on the patient's abdomen. The treatment beam is enabled only when the block is in between a predefined abdomen motion range as determined during the CT simulation process. A LabVIEW program was developed to record both beam status (i.e. on/off) and distance measurements. In this study the DML was only used to monitor the position of a single point on the chest and no clinical decisions/adjustments were made based on these measurements.

Results and Conclusions:

Thus far, 34 fractions have been recorded for 4 patients. As such, the performance of our DIBH treatment technique cannot be fairly evaluated at this point. However, deviations between expected and measured distances have been observed and if these are found to be reproducible, then modifications in our treatment procedures and policies will have to take place.
Poster – 39: Using Optical Scanner and 3D Printer Technology to Create Lead Shielding for Radiotherapy of Facial Skin Cancer with Low Energy Photons
Authors: Rickey Daniel , Leylek Ahmet , Dubey Arbind , Sasaki David , Harris Chad , Butler Jim , Sharma Ankur , McCurdy Boyd , Alpuche Aviles Jorge E.
Published: August 2016

Purpose:

Treatment of skin cancers of the face using orthovoltage radiotherapy often requires lead shielding. However, creating a lead shield can be difficult because the face has complex and intricate contours. The traditional process involved creating a plaster mould of the patient's face can be difficult for patients. Our goal was to develop an improved process by using an optical scanner and 3D printer technology.

Methods:

The oncologist defined the treatment field by drawing on each patient's skin. Three‐dimensional images were acquired using a consumer‐grade optical scanner. A 3D model of each patient's face was processed with mesh editing software before being printed on a 3D printer. Using a hammer, a 3 mm thick layer of lead was formed to closely fit the contours of the model. A hole was then cut out to define the field.

Results:

The lead shields created were remarkably accurate and fit the contours of the patients. The hole defining the field exposed only a minimally sized site to be exposed to radiation, while the rest of the face was protected. It was easy to obtain perfect symmetry for the definition of parallel opposed beams.

Conclusion:

We are routinely using this technique to build lead shielding that wraps around the patient as an alternative to cut‐outs. We also use it for treatment of the tip of the nose using a parallel opposed pair beams with a wax nose block. We found this technique allows more accurate delineation of the cut‐out and a more reproducible set‐up.
Poster ‐ 42: TB ‐ ARC: A Total Body photon ARC technique using a commercially available linac
Authors: Evans Michael D. C. , Ruo Russell , Patrocinio Horacio J. , Poon Emily , Freeman Carolyn , Hijal Tarek , Parker William
Published: August 2016

We have developed a total body photon irradiation technique using multiple overlapping open field arcs (TB‐ARC). This simple technique uses predetermined arc‐weights, with MUs calculated as a function of prescription depth only. Patients lie on a stretcher, in the prone/supine treatment position with AP/PA arcs. This treatment position has many advantages including ease of delivery (especially for tall, pediatric or compromised patients), dose uniformity, simplicity for organ shielding, and imaging capabilities.

Using a Varian TrueBeam linac, 14 arcs using 40×40 cm2 6 MV open photon beams, sweeping across 10 degrees each, complete a 140 degree arc. The nominal SSD at zero degrees is 200 cm. Arcs at the sweep limits (+/− 70 degrees) are differentially weighted and deliver a dose within 10% of the prescription on central axis, at a depth of 10 cm over a superior‐inferior length of 275 cm.

CT planning using Varian Eclipse enables dose evaluation. A custom made beam spoiler, consisting of a 2.5 m sheet of polycarbonate (6 mm thick) increases the surface dose from 45% to 90%. This beam spoiler also serves as a support in the event that differential attenuation is required for organs such as lung, heart, liver, kidneys. The geometry of the sweeping beam technique limits organ dose (using varying thicknesses of melting alloy) to about 20% and 40% of prescription at dmax and midplane respectively. Digital imaging with a portable DR cassette enables proper attenuator location prior to treatment.
Sci‐Fri AM: MRI and Diagnostic Imaging ‐ 03: The influence of sampling percentage in deformable registration on kinetic model analysis results in DCE‐MRI of the breast
Authors: Mouawad Matthew , Biernaski Heather , Brackstone Muriel , Klassen Martyn , Lock Michael , Prato Frank S. , Thompson R. Terry , Gaede Stewart , Gelman Neil
Published: August 2016

Purpose:

Dynamic contrast enhanced (DCE) MRI is applied extensively for diagnosis and treatment monitoring of breast cancer. However, patient motion can introduce artificial variation in the signal enhancement curves. Non‐rigid registration can improve the curves but computation time can be long. Reducing the percentage of the image sampled (PS) can reduce time at the theoretical cost of registration accuracy. This work investigates the influence of PS on kinetic model analysis results and goodness‐of‐fit.

Methods:

DCE images were acquired using a 3T Siemens Biograph mMR. Deformable registration was performed on one patient dataset with 3Dslicer using PS values of 5, 20, and 100%. For three regions of interest within the tumor, tissue contrast agent concentration values versus time were generated and analyzed using the TOFTS pharmacokinetic model. Model parameters, their 95% confidence intervals and the coefficients of variation (CV), which served as a measure of goodness of fit, were recorded.

Results:

Computation time was approximately 16, 8, and 4 minutes/image for 100, 20, and 5 PS. The CV decreased following registration and there was a trend of decreasing CV with increasing PS. However, no differences in parameter values obtained with 100% PS and parameters values obtained with lower PS were observed. Substantial differences were found between parameter values obtained with versus without registration

Conclusions:

Increasing PS led to improved goodness‐of‐fit for the kinetic model analysis, at the expense of substantially increased computation time. However, this improved fit did not appear to influence parameter values for this patient.
Sci‐Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques ‐ 04: Assessment of intra‐fraction motion during lung SABR VMAT using a custom abdominal compression device
Authors: Hyde Derek , Robinson Mark , Araujo Cynthia , Teke Tony , Halperin Ross , Petrik David , Mou Benjamin , Mohamed Islam
Published: August 2016

Purpose:

Lung SABR patients are treated using Volumetrically Modulated Arc Therapy (VMAT), utilizing 2 arcs with Conebeam CT (CBCT) image‐guidance prior to each arc. Intra‐fraction imaging can prolong treatment time (up to 20%), and the aim of this study is to determine if it is necessary.

Methods:

We utilize an in‐house abdominal compression device to minimize respiratory motion, 4DCT to define the ITV, a 5 mm PTV margin and a 2–3 mm PRV margin. We treated 23 patients with VMAT, fifteen were treated to 48 Gy in 4 fractions, while eight were treated with up to 60 Gy in 8 fractions. Intrafraction motion was assessed by the translational errors recorded for the second CBCT.

Results:

There was no significant difference (t‐test, p=0.93) in the intra‐fraction motion between the patients treated with 4 and 8 fractions, or between the absolute translations in each direction (ANOVA, p=0.17). All 124 intra‐fraction CBCT images were analysed and 95% remained localized within the 5 mm PTV margin The mean magnitude of the vector displacement was 1.8 mm.

Conclusions:

For patients localized with an abdominal compression device, the intrafraction CBCT image may not be necessary, if it is only the tumor coverage that is of concern, as the patients are typically well within the 5 mm PTV margin. On the other hand, if there is a structure with a smaller PRV margin, an intrafraction CBCT is recommended to ensure that the dose limit for the organ at risk is not exceeded.
The Macro and Micro of it Is that Entropy Is the Spread of Energy
Authors: Phillips Jeffrey A.
Published: August 2016

While entropy is often described as “disorder,” it is better thought of as a measure of how spread out energy is within a system. To illustrate this interpretation of entropy to introductory college or high school students, several activities have been created. Students first study the relationship between microstates and macrostates to better understand the probabilities involved. Then, each student observes how a system evolves as energy is allowed to move within it. By studying how the class’s ensemble of systems evolves, the tendency of energy to spread, rather than concentrate, can be observed. All activities require minimal equipment and provide students with a tactile and visual experience with entropy.
Using Peer Feedback to Promote Reflection on Open-Ended Problems
Authors: Reinholz Daniel L. , Dounas-Frazer Dimitri R.
Published: August 2016

This paper describes a new approach for learning from homework called Peer-Assisted Reflection (PAR). PAR involves students using peer feedback to improve their work on open-ended homework problems. Collaborating with peers and revising one’s work based on the feedback of others are important aspects of doing and learning physics. While notable exceptions exist, homework and exams are generally individual activities that do not support collaboration and refinement, which misses important opportunities to use assessment for learning. In contrast, PAR provides students with a structure to iteratively engage with challenging, open-ended problems and solicit the input of their peers to improve their work.
Signal type and signal-to-noise ratio interact to affect cortical auditory evoked potentials
Authors: Billings Curtis J. , Grush Leslie D.
Published: August 2016

Use of speech signals and background noise is emerging in cortical auditory evoked potential (CAEP) studies; however, the interaction between signal type and noise level remains unclear. Two experiments determined the interaction between signal type and signal-to-noise ratio (SNR) on CAEPs. Three signals (syllable /ba/, 1000-Hz tone, and the /ba/ envelope with 1000-Hz fine structure) with varying SNRs were used in two experiments, demonstrating signal-by-SNR interactions due to both envelope and spectral characteristics. When using real-world stimuli such as speech to evoke CAEPs, temporal and spectral complexity leads to differences with traditional tonal stimuli, especially when presented in background noise.
Auditory “bubbles”: Efficient classification of the spectrotemporal modulations essential for speech intelligibility
Authors: Venezia Jonathan H. , Hickok Gregory , Richards Virginia M.
Published: August 2016

Speech intelligibility depends on the integrity of spectrotemporal patterns in the signal. The current study is concerned with the speech modulation power spectrum (MPS), which is a two-dimensional representation of energy at different combinations of temporal and spectral (i.e., spectrotemporal) modulation rates. A psychophysical procedure was developed to identify the regions of the MPS that contribute to successful reception of auditory sentences. The procedure, based on the two-dimensional image classification technique known as “bubbles” (Gosselin and Schyns (2001). Vision Res. 41, 2261–2271), involves filtering (i.e., degrading) the speech signal by removing parts of the MPS at random, and relating filter patterns to observer performance (keywords identified) over a number of trials. The result is a classification image (CImg) or “perceptual map” that emphasizes regions of the MPS essential for speech intelligibility. This procedure was tested using normal-rate and 2×-time-compressed sentences. The results indicated: (a) CImgs could be reliably estimated in individual listeners in relatively few trials, (b) CImgs tracked changes in spectrotemporal modulation energy induced by time compression, though not completely, indicating that “perceptual maps” deviated from physical stimulus energy, and (c) the bubbles method captured variance in intelligibility not reflected in a common modulation-based intelligibility metric (spectrotemporal modulation index or STMI).
Maximum bow force revisited
Authors: Mores Robert
Published: August 2016

Schelleng [J. Acoust. Soc. Am. 53, 26–41 (1973)], Askenfelt [J. Acoust. Soc. Am. 86, 503–516 (1989)], Schumacher [J. Acoust. Soc. Am. 96, 1985–1998 (1994)], and Schoonderwaldt, Guettler, and Askenfelt [Acta Acust. Acust. 94, 604–622 (2008)] formulated—in different ways—how the maximum bow force relates to bow velocity, bow-bridge distance, string impedance, and friction coefficients. Issues of uncertainty are how to account for friction or for the rotational admittance of the strings. Related measurements at the respective transitions between regimes of Helmholtz motion and non-Helmholtz motion employ a variety of bowing machines and stringed instruments. The related findings include all necessary parameters except the friction coefficients, leaving the underlying models unconfirmed. Here, a bowing pendulum has been constructed which allows precise measurement of relevant bowing parameters, including the friction coefficients. Two cellos are measured across all strings for three different bow-bridge distances. The empirical data suggest that—taking the diverse elements of existing models as options—Schelleng's model combined with Schumacher's velocity term yields the best fit. Furthermore, the pendulum employs a bow driving mechanism with adaptive impedance which discloses that mentioned regimes are stable and transitions between them sometimes require a hysteresis on related parameters.
Cardiometabolic risk loci share downstream cis- and trans-gene regulation across tissues and diseases
Authors: Franzén Oscar , Ermel Raili , Cohain Ariella , Akers Nicholas K. , Di Narzo Antonio , Talukdar Husain A. , Foroughi-Asl Hassan , Giambartolomei Claudia , Fullard John F. , Sukhavasi Katyayani , Köks Sulev , Gan Li-Ming , Giannarelli Chiara , Kovacic Jason C. , Betsholtz Christer , Losic Bojan , Michoel Tom , Hao Ke , Roussos Panos , Skogsberg Josefin , Ruusalepp Arno , Schadt Eric E. , Björkegren Johan L. M.
Published: August 2016

Genetic variation and coronary artery disease

Most genetic variants lie outside protein-coding genes, but their effects, especially in human health, are not well understood. Franzén
et al.
examined gene expression in tissues affected by coronary artery disease (CAD). They found that individuals with loci that have been associated with CAD in genome-wide analyses had different patterns of tissue-specific gene expression than individuals without these genetic variants. Similarly, tissues not associated with CAD did not have CAD-like expression patterns. Thus, tissue-specific data can be used to dissect the genetic effects that predispose individuals to CAD.

Science
, this issue p.
827
Combining satellite imagery and machine learning to predict poverty
Authors: Jean Neal , Burke Marshall , Xie Michael , Davis W. Matthew , Lobell David B. , Ermon Stefano
Published: August 2016

Measuring consumption and wealth remotely

Nighttime lighting is a rough proxy for economic wealth, and nighttime maps of the world show that many developing countries are sparsely illuminated. Jean
et al.
combined nighttime maps with high-resolution daytime satellite images (see the Perspective by Blumenstock). With a bit of machine-learning wizardry, the combined images can be converted into accurate estimates of household consumption and assets, both of which are hard to measure in poorer countries. Furthermore, the night- and day-time data are publicly available and nonproprietary.

Science
, this issue p.
790
; see also p.
753
Multifaceted interactions between adaptive immunity and the central nervous system
Authors: Kipnis Jonathan
Published: August 2016

Neuroimmunologists seek to understand the interactions between the central nervous system (CNS) and the immune system, both under homeostatic conditions and in diseases. Unanswered questions include those relating to the diversity and specificity of the meningeal T cell repertoire; the routes taken by immune cells that patrol the meninges under healthy conditions and invade the parenchyma during pathology; the opposing effects (beneficial or detrimental) of these cells on CNS function; the role of immune cells after CNS injury; and the evolutionary link between the two systems, resulting in their tight interaction and interdependence. This Review summarizes the current standing of and challenging questions related to interactions between adaptive immunity and the CNS and considers the possible directions in which these aspects of neuroimmunology will be heading over the next decade.
Memory lane
Patient H.M. A Story of Memory, Madness, and Family Secrets
Luke Dittrich
Random House, 2016, 464 pp.
Authors: Stark Laura
Published: August 2016

An intimate portrait of a famous amnesiac is also a tale of personal grievances
Another reason to eat more fiber
Authors: VanHook Annalisa M.
Published: August 2016

Metabolites produced by fiber-fermenting gut bacteria help B cells produce antibodies.
Detection of Anti-Hepatitis B Virus Drug Resistance Mutations Based on Multicolor Melting Curve Analysis
Authors: Mou Yi , Athar Muhammad Ammar , Wu Yuzhen , Xu Ye , Wu Jianhua , Xu Zhenxing , Hayder Zulfiqar , Khan Saeed , Idrees Muhammad , Nasir Muhammad Israr , Liao Yiqun , Li Qingge
Published: August 2016

Detection of anti-hepatitis B virus (HBV) drug resistance mutations is critical for therapeutic decisions for chronic hepatitis B virus infection. We describe a real-time PCR-based assay using multicolor melting curve analysis (MMCA) that could accurately detect 24 HBV nucleotide mutations at 10 amino acid positions in the reverse transcriptase region of the HBV polymerase gene. The two-reaction assay had a limit of detection of 5 copies per reaction and could detect a minor mutant population (5% of the total population) with the reverse transcriptase M204V amino acid mutation in the presence of the major wild-type population when the overall concentration was 104copies/μl. The assay could be finished within 3 h, and the cost of materials for each sample was less than $10. Clinical validation studies using three groups of samples from both nucleos(t)ide analog-treated and -untreated patients showed that the results for 99.3% (840/846) of the samples and 99.9% (8,454/8,460) of the amino acids were concordant with those of Sanger sequencing of the PCR amplicon from the HBV reverse transcriptase region (PCR Sanger sequencing). HBV DNA in six samples with mixed infections consisting of minor mutant subpopulations was undetected by the PCR Sanger sequencing method but was detected by MMCA, and the results were confirmed by coamplification at a lower denaturation temperature-PCR Sanger sequencing. Among the treated patients, 48.6% (103/212) harbored viruses that displayed lamivudine monoresistance, adefovir monoresistance, entecavir resistance, or lamivudine and adefovir resistance. Among the untreated patients, the Chinese group had more mutation-containing samples than did the Pakistani group (3.3% versus 0.56%). Because of its accuracy, rapidness, wide-range coverage, and cost-effectiveness, the real-time PCR assay could be a robust tool for the detection if anti-HBV drug resistance mutations in resource-limited countries.
Identification and Antifungal Susceptibility Profiles of Candida haemulonii Species Complex Clinical Isolates from a Multicenter Study in China
Authors: Hou Xin , Xiao Meng , Chen Sharon C.-A. , Wang He , Cheng Jing-Wei , Chen Xin-Xin , Xu Zhi-Peng , Fan Xin , Kong Fanrong , Xu Ying-Chun
Published: August 2016

Candida haemulonii
complex (
Candida haemulonii
,
Candida haemulonii
var.
vulnera
, and
Candida duobushaemulonii
) consists of emerging pathogens. Thirty-one isolates from 14 hospitals in China were studied for their species classification and antifungal susceptibilities. Performances of molecular (i.e., ribosomal DNA [rDNA] internal transcribed spacer [ITS] sequencing, D1/D2 sequencing, and ITS sequencer-based capillary gel electrophoresis [SCGE]) and phenotypic identification methods in species identification were compared. Twenty-six (83.9%) of 31 isolates were identified as
C. haemulonii
and 5 isolates were identified as
C. duobushaemulonii
by ITS sequencing as the reference method; results obtained by D1/D2 sequencing and ITS SCGE were concordant with those obtained by ITS sequencing for all (100%) of the isolates. All 31 isolates were identified as
C. haemulonii
by the Vitek matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system (bioMérieux, France), whereas the Bruker MS system (Bruker Daltoniks, Germany) correctly provided species identification for 77.4% and 100% of isolates using cutoff scores for species of ≥2.0 and ≥1.70, respectively. The Vitek 2 compact (bioMérieux) only identified 9 (29%) of 31 isolates. All isolates showed high MICs for amphotericin B (range, 2 to >8 μg/ml) and fluconazole (≥128 μg/ml) but low MICs (≤0.5 μg/ml) for the echinocandins. Our results reinforce the need for MALDI-TOF MS and/or molecular differentiation of species within the
C. haemulonii
complex. The multiresistant antifungal susceptibility profile of these isolates represents a challenge to therapy.
Near-Atomic Resolution Structure of a Highly Neutralizing Fab Bound to Canine Parvovirus
Authors: Organtini Lindsey J. , Lee Hyunwook , Iketani Sho , Huang Kai , Ashley Robert E. , Makhov Alexander M. , Conway James F. , Parrish Colin R. , Hafenstein Susan
Published: August 2016

Canine parvovirus (CPV) is a highly contagious pathogen that causes severe disease in dogs and wildlife. Previously, a panel of neutralizing monoclonal antibodies (MAb) raised against CPV was characterized. An antibody fragment (Fab) of MAb E was found to neutralize the virus at low molar ratios. Using recent advances in cryo-electron microscopy (cryo-EM), we determined the structure of CPV in complex with Fab E to 4.1 Å resolution, which allowed
de novo
building of the Fab structure. The footprint identified was significantly different from the footprint obtained previously from models fitted into lower-resolution maps. Using single-chain variable fragments, we tested antibody residues that control capsid binding. The near-atomic structure also revealed that Fab binding had caused capsid destabilization in regions containing key residues conferring receptor binding and tropism, which suggests a mechanism for efficient virus neutralization by antibody. Furthermore, a general technical approach to solving the structures of small molecules is demonstrated, as binding the Fab to the capsid allowed us to determine the 50-kDa Fab structure by cryo-EM.

IMPORTANCE
Using cryo-electron microscopy and new direct electron detector technology, we have solved the 4 Å resolution structure of a Fab molecule bound to a picornavirus capsid. The Fab induced conformational changes in regions of the virus capsid that control receptor binding. The antibody footprint is markedly different from the previous one identified by using a 12 Å structure. This work emphasizes the need for a high-resolution structure to guide mutational analysis and cautions against relying on older low-resolution structures even though they were interpreted with the best methodology available at the time.
Widespread dispersal and aging of organic carbon in shallow marginal seas
Authors: Bao Rui , McIntyre Cameron , Zhao Meixun , Zhu Chun , Kao Shuh-Ji , Eglinton Timothy I.
Published: August 2016

The occurrence of pre-aged organic carbon (OC) in continental margin surface sediments is a commonly observed phenomenon, yet the nature, sources, and causes of this aged OC remain largely undetermined for many continental shelf settings. Here we present the results of an extensive survey of the abundance and radiocarbon content of OC in surface sediments from the northern Chinese marginal seas. Pre-aged OC is associated with both coarser (>63 µm) and finer (<63 µm) sedimentary components; measurements on specific grain-size fractions reveal that it is especially prevalent within the 20–63 µm fraction of inner shelf sediments. We suggest that organic matter associated with this sortable silt fraction is subject to protracted entrainment in resuspension-deposition loops during which it ages, is modified, and is laterally dispersed, most likely via entrainment within benthic nepheloid layers. This finding highlights the complex dynamics and predepositional history of organic matter accumulating in continental shelf sediments, with implications for our understanding of carbon cycling on continental shelves, development of regional carbon budgets, and interpretation of sedimentary records.
Kimberlites and the start of plate tectonics
Authors: Stern R.J. , Leybourne M.I. , Tsujimori Tatsuki
Published: August 2016

We want to know when plate tectonics began and will consider any important Earth feature that shows significant temporal evolution. Kimberlites, the primary source of diamonds, are rare igneous features. We analyze their distribution throughout Earth history; most are young (∼95% are younger than 0.75 Ga), but rare examples are found as far back as the Archean (older than 2.5 Ga). Although there are differing explanations for this age asymmetry (lack of preservation, lack of exposure, fewer mantle plumes, or lack of old thick lithosphere in the Archean and Proterozoic), we suggest that kimberlite eruptions are a consequence of modern-style plate tectonics, in particular subduction of hydrated oceanic crust and sediments deep into the mantle. This recycling since the onset of modern-style plate tectonics ca. 1 Ga has massively increased mantle CO2 and H2O contents, leading to the rapid and explosive ascent of diamond-bearing kimberlite magmas. The age distribution of kimberlites, combined with other large-scale tectonic indicators that are prevalent only in the past ∼1 Ga (blueschists, glaucophane-bearing eclogites; coesite- or diamond-bearing ultrahigh-pressure metamorphic rocks; lawsonite-bearing metamorphic rocks; and jadeitites), indicates that plate tectonics, as observed today, has only operated for <25% of Earth history.
PATIENT/CARERS' RECOLLECTION OF MEDICINES RELATED INFORMATION FROM AN OUT-PATIENT CLINIC APPOINTMENT
Authors: Aston Jeff , Patel Natasha , Smuels Justin , Aujla Teena , Malesi Georgia , Huynh Chi , Wilson Keith , Terry David
Published: August 2016

Aim

To identify what medicines related information children/young people or their parents/carers are able to recall following an out-patient clinic appointment.

Method

A convenience sample of patients' prescribed at least one new long-term (>6 weeks) medicine were recruited from a single UK paediatric hospital out-patient pharmacy.

A face-to-face semi-structured questionnaire was administered to participants when they presented with their prescription. The questionnaire included the following themes: names of the medicines, therapeutic indication, dose regimen, duration of treatment and adverse effects.

The results were analysed using Microsoft Excel 2013.

Results

One hundred participants consented and were included in the study. One hundred and forty-five medicines were prescribed in total. Participants were able to recall the names of 96 (66%) medicines and were aware of the therapeutic indication for 142 (97.9%) medicines. The dose regimen was accurately described for 120 (82.8%) medicines with the duration of treatment known for 132 (91%). Participants mentioned that they had been advised about side effects for 44 (30.3%) medicines. Specific counselling points recommended by the BNFc1, were either omitted or not recalled by participants for the following systemic treatments: cetirizine (1), chlorphenamine (1), desmopressin (2), hydroxyzine (2), itraconazole (1), piroxicam (2), methotrexate (1), stiripentol (1) and topiramate (1).

Conclusion

Following an out-patient consultation, where a new medicine is prescribed, children and their parents/carers are usually able to recall the indication, dose regimen and duration of treatment. Few were able to recall, or were told about, possible adverse effects. This may include some important drug specific effects that require vigilance during treatment.

Patients, along with families and carers, should be involved in the decision to prescribe a medicine.2 This includes a discussion about the benefits of the medicine on the patient's condition and possible adverse effects.2 Treatment side effects have been shown to be a factor in treatment non-adherence in paediatric long-term medical conditions.3 Practitioners should explain to patients, and their family members or carers where appropriate, how to identify and report medicines-related patient safety incidents.4 However, this study suggests that medical staff may not be comfortable discussing the adverse effects of medicines with patients or their parents/carers.

Further research in to the shared decision making process in the paediatric out-patient clinic when a new long-term medicine is prescribed is required to further support medicines adherence and the patient safety agenda.
Goltz syndrome: a rare case of father-to-daughter transmission
Authors: Gupta Vishal , Saginatham Himabindu , Arava Sudheer , Sethuraman Gomathy
Published: August 2016

An 8-year-old girl presented to us with skin-coloured to yellowish soft compressible papules, intermixed with hypopigmented and hyperpigmented macules in a Blaschkoid pattern, and ‘lobster-claw deformity’ affecting her bilateral feet. Additional examination findings included short stature, facial asymmetry, low-set ears, hypodontia, enamel hypoplasia, tonsillar enlargement and spina-bifida occulta at S1–3 vertebral level. A diagnosis of Goltz syndrome was suspected clinically, which was confirmed on skin biopsy. Her father also had hypopigmented and hyperpigmented macules in a Blaschkoid distribution, ‘lobster-claw’ deformity and kyphoscoliosis. None of the other family members were affected.
10 steps to facilitating patient death at home
Authors: Kerwat Doa’a , Sayma Meelad , Saleh Dina , Oyewole Folashade , Wahid Samad , Jamshaid Shiraz , Ahmed Aaniya
Published: August 2016

Introduction

Evidence suggests that most patients want to die at home, however most die in hospital.

Aim

To identify specific action points to facilitate more patients to achieve home death, should they wish to do so.

Methods

A two-step study design was adopted. A systematic literature review (SLR) and primary qualitative data collection. In the SLR 3241 papers were retrieved. 72 articles remained after screening and filtering processes. Qualitative articles were analysed using meta-ethnography and quantitative articles were analysed using a descriptive approach. 33 in-depth interviews were conducted with experts in end-of-life care delivery, with approval from Imperial College Research Ethics Committee. Thematic Analysis of interview transcripts was conducted. The results from both the SLR and primary data collection were then amalgamated to produce a set of overarching barriers and facilitators. Subsequently, action points were produced to overcome the barriers and facilitators identified.

Results

Ten action points were identified to enable patients to achieve home death. These action points include: ‘coordinate services’ and ‘evaluate the efficiency of current resource allocation to enhance quality’.

Conclusions

By implementing these ten action points, the barriers to achieving home death would be dissolved, allowing patients to die in their preferred location. However, it is important to acknowledge that these action points are both time-consuming and potentially financially straining to achieve. Consequently, further research is required to identify how susceptible these action points are to implementation, prioritising those with the greatest impact.
The role of the volunteer research assistant in a hospice setting
Authors: Brigden Charlotte , Southon Jeff , Cawley Declan
Published: August 2016

Background

A hospice setting has a small, busy research team and the volunteer research assistant is an important role within the team, providing additional support for delivery of research projects and related activities.

The role was first introduced in 2014 following the development of research infrastructure and capacity building within the organisation.

Aim and method

To introduce volunteers to support hospice research including:

Assisting with set up and co-ordination of studies. Including support with the organisation and collation of study materials, meetings and training to the site.

Assisting the set up and running of research events by helping organise attendance lists and other materials. Greeting and registering attendees on arrival.

Data entry and data checking.

Results

Involved volunteers has provided the hospice with additional research capacity to deliver projects and other research related activities.

Volunteers with different skills, expertise and experience of the organisation has enabled matching their input to the needs of the research activity.

Experience of involving volunteers has enabled development of a role description for a ‘volunteer research assistant’.

Introducing the role of the ‘volunteer research assistant’ has helped to promote ownership of this unique position to those involved. There is value in developing this role to provide regular support in developing, setup, delivering and disseminating research within hospices.

Conclusions

Involving volunteers as part of the research team has been a rewarding one working towards the hospice’s strategy to become increasingly research active to provide the best care for patients and their families.