bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Intramolecular Cyclization of 2‐(Buta‐1,3‐dienyl)benzyl Anions to 6,7(9)‐Dihydro‐5H‐benzocycloheptenyl Anions Leading to Successive Formation of 1,2‐Dihydrocyclopropa[a]naphthalenes
Authors: Saitoh Hisashi , Ijuin Hisako K. , Watanabe Nobuko , Matsumoto Masakatsu
Published: October 2013

When treated with LiNiPr2 (LDA) at −78°, 1‐[(methylsulfanyl)methyl]‐2‐[(1Z,3E)‐4‐phenylbuta‐1,3‐dien‐1‐yl]benzene easily cyclized to form benzocycloheptenyl anion, which successively underwent intramolecular nucleophilic substitution to give a cyclopropanaphthalene. Similar LDA‐mediated cyclization also occurred for 4‐phenyl‐ or 4‐methyl‐substituted 1‐[2‐(methoxymethyl)phenyl]buta‐1,3‐dienes to furnish the corresponding benzocycloheptenes and cyclopropanaphthalenes. A 4‐tert‐butyl analog also underwent LDA‐mediated cyclization to give a benzocycloheptene, but not a cyclopropanaphthalene.
Metal‐Ion‐Binding Analogs of Ribonucleosides: Preparation and Formation of Ternary Pd2+ and Hg2+ Complexes with Natural Pyrimidine Nucleosides
Authors: Golubev Oleg , Lönnberg Tuomas , Lönnberg Harri
Published: October 2013

Four metal‐ion‐binding nucleosides, viz. 2,6‐bis(1‐methylhydrazinyl)‐9‐(β‐D‐ribofuranosyl)‐9H‐purine (2a) and its N‐acetylated derivative, 2b, 2,4‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐5‐(β‐D‐ribofuranosyl)pyrimidine (3), and 2,4‐bis(1‐methylhydrazinyl)‐5‐(β‐D‐ribofuranosyl)pyrimidine (4) have been synthesized. The ability of these nucleosides and the previously prepared 2,6‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐9‐(β‐D‐ribofuranosyl)‐9H‐purine to form Pd2+‐ and Hg2+‐mediated complexes with uridine has been studied by 1H‐NMR spectroscopy. To obtain additional support for the interpretation of the NMR data, comparative measurements on the ternary‐complex formation between pyridine‐2,6‐dicarboxamide (5), pyrimidine nucleosides, and K2PdCl4 were carried out.
Molecular characterization of cancer reveals interactions between ionizing radiation and chemicals on rat mammary carcinogenesis
Authors: Imaoka Tatsuhiko , Nishimura Mayumi , Doi Kazutaka , Tani Shusuke , Ishikawa Ken‐ichi , Yamashita Satoshi , Ushijima Toshikazu , Imai Takashi , Shimada Yoshiya
Published: October 2013

Although various mechanisms have been inferred for combinatorial actions of multiple carcinogens, these mechanisms have not been well demonstrated in experimental carcinogenesis models. We evaluated mammary carcinogenesis initiated by combined exposure to various doses of radiation and chemical carcinogens. Female rats at 7 weeks of age were γ‐irradiated (0.2–2 Gy) and/or exposed to 1‐methyl‐1‐nitrosourea (MNU) (20 or 40 mg/kg, single intraperitoneal injection) or 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) (40 mg/kg/day by gavage for 10 days) and were observed until 50 weeks of age. The incidence of mammary carcinoma increased steadily as a function of radiation dose in the absence of chemicals; mathematical analysis supported an additive increase when radiation was combined with a chemical carcinogen, irrespective of the chemical species and its dose. Hras mutations were characteristic of carcinomas that developed after chemical carcinogen treatments and were overrepresented in carcinomas induced by the combination of radiation and MNU (but not PhIP), indicating an interaction of radiation and MNU at the level of initiation. The expression profiles of seven classifier genes, previously shown to distinguish two classes of rat mammary carcinomas, categorized almost all examined carcinomas that developed after individual or combined treatments with radiation (1 Gy) and chemicals as belonging to a single class; more comprehensive screening using microarrays and a separate test sample set failed to identify differences in gene expression profiles among these carcinomas. These results suggest that a complex, multilevel interaction underlies the combinatorial action of radiation and chemical carcinogens in the experimental model.
Interleukin‐33/ST2 axis promotes breast cancer growth and metastases by facilitating intratumoral accumulation of immunosuppressive and innate lymphoid cells
Authors: Jovanovic Ivan P. , Pejnovic Nada N. , Radosavljevic Gordana D. , Pantic Jelena M. , Milovanovic Marija Z. , Arsenijevic Nebojsa N. , Lukic Miodrag L.
Published: October 2013

The role of IL‐33/ST2 pathway in antitumor immunity is unclear. Using 4T1 breast cancer model we demonstrate time‐dependent increase of endogenous IL‐33 at both the mRNA and protein levels in primary tumors and metastatic lungs during cancer progression. Administration of IL‐33 accelerated tumor growth and development of lung and liver metastases, which was associated with increased intratumoral accumulation of CD11b+Gr‐1+ TGF‐β1+ myeloid‐derived suppressor cells (MDSCs) that expressed IL‐13α1R, IL‐13‐producing Lin−Sca‐1+ST2+ innate lymphoid cells (ILCs) and CD4+Foxp3+ST2+IL‐10+ Tregs compared to untreated mice. Higher incidence of monocytic vs. granulocytic MDSCs and plasmocytoid vs. conventional dendritic cells (DCs) was present in mammary tumors of IL‐33‐treated mice. Intratumoral NKp46+NKG2D+ and NKp46+FasL+ cells were markedly reduced after IL‐33 treatment, while phosphate‐buffered saline‐treated ST2‐deficient mice had increased frequencies of these tumoricidal natural killer (NK) cells compared to untreated wild‐type mice. IL‐33 promoted intratumoral cell proliferation and neovascularization, which was attenuated in the absence of ST2. Tumor‐bearing mice given IL‐33 had increased percentages of splenic MDSCs, Lin−Sca‐1+ ILCs, IL‐10‐expressing CD11c+ DCs and alternatively activated M2 macrophages and higher circulating levels of IL‐10 and IL‐13. A significantly reduced NK cell, but not CD8+ T‐cell cytotoxicity in IL‐33‐treated mice was observed and the mammary tumor progression was not affected when CD8+ T cells were in vivo depleted. We show a previously unrecognized role for IL‐33 in promoting breast cancer progression through increased intratumoral accumulation of immunosuppressive cells and by diminishing innate antitumor immunity. Therefore, IL‐33 may be considered as an important mediator in the regulation of breast cancer progression.
INTEGRATION AMONG EGYPTIAN GOVERNORATES TO OPTIMIZE IRRIGATION WATER USE UTILIZING WEIGHT GOAL PROGRAMMING TECHNIQUE
Authors: El‐Gafy Inas
Published: October 2013

Egypt has limited available water resources. One of the main targets of the national water resources and agricultural policies in Egypt is the optimal use of these scarce resources. The free cropping pattern policy applied in Egypt gives farmers the right to decide on the cultivated crops according to their own choice. Pollution of the environment and saving irrigation water do not really represent constraining factors for farmers in their decision. The main objective of this research is to investigate the consequences of applying addressed integration among the Egyptian governorates, in order to produce a cropping pattern that optimizes irrigation water use, while considering the viewpoints of farmers as well as decision‐makers. Moreover, a partially free cropping pattern policy is scrutinized through the study. A multi‐objective optimization approach utilizing the weight goal programming technique was applied to achieve the research. The results of the study illustrated that applying addressed integration among the Egyptian governorates and a partially free cropping pattern policy saves water, reduces cultivated area, lessens fertilizer usage, and increases the net return from crop production. Copyright © 2013 John Wiley & Sons, Ltd.
The breast cancer patient's experience of making radiation therapy treatment decisions
Authors: Halkett Georgia KB , Arbon Paul , Scutter Sheila D , Borg Martin
Published: October 2013

Women who are diagnosed with breast cancer have many decisions to make during the course of their treatment. The aims of this paper are to describe the women's experience of making radiation therapy treatment decisions for early breast cancer and to explore how women feel about receiving radiation therapy. An in‐depth understanding of the women's experience was developed using a qualitative research approach underpinned by hermeneutic phenomenology. In‐depth interviews were conducted with 18 women who had completed treatment for early breast cancer. The themes that emerged from the data were: being challenged, getting ready, beyond control, regaining a sense of control and getting through it. This study provides health professionals with an initial understanding of the women's perspective of the experience of making radiation therapy treatment decisions for early breast cancer. This study concludes by suggesting that further research needs to be conducted to gain an understanding of how other patients feel about treatment decision‐making and radiation therapy.
Ultrasound as a secondary screening tool in mammographically dense breasts
Authors: Griggs Kylie
Published: October 2013

It is well known that breast screening is a part of our society and is designed to reduce the mortality and morbidity from breast cancer. Mammography is the imaging modality of choice in a breast screening environment. Both the detection rate of mammography in a screening environment and the sensitivity of mammography in symptomatic women are known to be greater than that of ultrasound. However, after a review of literature both of these are said to increase when the two imaging modalities are combined. This paper will present that mammography has limitations in breast imaging, especially in women with dense breasts and that ultrasound can have a benefit as a secondary screening tool in these women. It will be shown that although ultrasound also has its limitations, these can be minimised with the implementation of effective education and imaging protocols.

The paper will conclude that although further research into ultrasound as screening tool is required, its use as a complement to mammography can only be of benefit to the general population.
A potential role for student portfolios in the medical radiation sciences
Authors: Currie Geoffrey M. , Wheat Janelle M.
Published: October 2013

There is a recognised need in higher education to develop authentic evidence of student learning outcomes. In medical radiation science, there is demand for a tool for ongoing course quality assurance and authentic evidence of the capabilities, skill base and knowledge base of graduates, with particular reference to the requirements for professional accreditation and the courses prescribed graduate attributes. The student portfolio is considered here as a potential tool for this purpose.

As a formative tool, the medical radiation science student portfolio may benefit industry by delivering highly self‐motivated, self‐reflective, professional and competent practitioners with retained deep understanding of theory conceptualised to practice. As a summative tool, the student portfolio would provide authentic evidence of student learning outcomes, graduate quality and attributes, and standards of competence.
An evaluation of safety policies and procedures in Australian magnetic resonance imaging departments
Authors: Burwell Jann , Davidson Rob
Published: October 2013

Stage 3 accreditation of medical imaging sites was introduced within Australia in 2004. For the first time, it was compulsory for medical imaging practices to comply with the guidelines for magnetic resonance imaging (MRI) safety of the Royal Australian and New Zealand College of Radiologists, with a compliance date of December 2005. Stages 1 and 2 had been designed specifically for medical imaging practices incorporating licensed magnetic resonance imaging (MRI) equipment, but Stage 3 had wider application. A questionnaire was sent to 110 MRI sites identified within Australia. This questionnaire was designed to assess how site‐specific MRI safety protocols have evolved and investigate the rigour with which these protocols are applied. Forty‐six of the questionnaires were returned and these form the basis of this report. Thirty‐nine of the respondents hold Medicare licenses for their MRI units and should, therefore, have successfully completed Stages 1 and 2 of the accreditation process.
Somnolence syndrome after cranial irradiation: a literature review
Authors: Woodford Katrina
Published: October 2013

Somnolence syndrome is a commonly seen, early‐delayed side effect of radiation treatment to the brain. Despite being a recognised side effect for over 30 years, many associated aspects of the syndrome are still unclear, such as which patients are most prone to the condition, what are its associated symptoms, what is its aetiology, what treatment factors affect it and how can it be managed? Literature has shown that somnolence syndrome can occur in children and adults after receiving cranial irradiation. The syndrome is characterised by a variety of symptoms, including mild drowsiness to extreme exhaustion, low‐grade fever, nausea, anorexia and headache. Symptoms generally appear between five to six weeks after the completion of treatment. Why and how the syndrome comes about is still uncertain. Popular theory suggests that it is due to transient demyelination of the nerve fibre. The condition has been shown to appear at doses as low as 12 Gy and up to 54 Gy with a fraction size dependence not yet established. The use of steroid therapy has proven to be an effective method to reduce the occurrence of somnolence syndrome in patients receiving cranial irradiation, with the optimal regime still to be determined. Health care professionals should acknowledge and warn their patients of the syndrome, ensuring proper care is available if it develops. Further study is required on the aetiology of the syndrome, the late neurological outcomes of the syndrome and the optimal steroid schedule for its management.
Radiographers' experiences of stress and methods of coping: a content analytic phenomenologic study
Authors: Ugwu Anthony Chukwuka , Ahamefule Kenneth Nwadinobi , Nwobi Ivor Chigozie
Published: October 2013

Stress has the potential to discourage radiographers from practice and to cause brain drain in the profession. The aim of this study was to consider stress, from a holistic perspective, of the radiographers' experiences.

Qualitative research methods were employed. Using random sampling, 10 radiographers, two from each of the five states of southeastern Nigeria were interviewed. The interview questions aimed to explore the experience of radiographers with a focus on the causes of stress and the associated coping mechanisms. Data analysis involved identification, coding of key concepts and their relationships.

A conceptual framework was developed regarding the causes of stress among radiographers and their relationship with other concepts identified by radiographers. The greatest cause of stress was high workload while the most popular coping mechanism was booking modifications.

The conceptual framework and methods of coping with stress reported in this study have important implications for professional practice and future research in Nigeria and beyond. Changes in work practices such as employment of more radiographers, positive attitude of management towards radiographers will reduce stress among radiographers in Nigeria and beyond.
Comparing immobilisation methods for the tangential treatment of large pendulous breasts
Authors: Barrett‐Lennard MJ , Thurstan SM
Published: October 2013

Large pendulous breasts pose particular challenges in stabilisation for radiotherapy, due to their inherent mobility. To ensure reproducibility of their positioning between fractions, customised breast immobilisation devices are designed to improve stabilisation and minimise toxicities to the skin and underlying lung. This study aims to review current methods of immobilisation for tangential treatment techniques to the large breast, assessing the range of devices commonly used and discover if any one technique can be recommended. A survey containing 13 questions was sent to 42 randomly‐selected centres performing tangential treatments for breast cancer. The questions were designed to assess each centre's opinion on the effectiveness of the immobilisation device and reproducibility of the breast position for patients with large pendulous breasts. Centres graded their responses using a Likert scale of 1–5, 1 being most effective to 5 being the least effective outcome. Additionally, centres were asked to identify if their current system had any advantages/disadvantages. Ten immobilisation devices were identified from 18 responses to the survey. The prone technique was the most popular, practiced by 22% of respondents. It also ranked consistently well over all in the questions from the survey. The breast board, thermoplastic mask, wireless bra, breast cups, Micropore tape™ (Livingstone International Pty Ltd, Rosebury, NSW, Australia), Vac fix® (S & S Technology, Houston, Texas, USA), stockings, breast rings and plastic L‐shaped supports were other devices identified by respondents. None of these other techniques were graded consistently well over the range of survey questions compared with the prone technique. Those using the prone technique were most satisfied with its effectiveness for patients with large pendulous breasts, however, it is acknowledged that the technique is not suitable for all patients.
Why do students choose the medical radiation science profession?
Authors: Bamba A , Bamba V , Chen Y , Deng Y , Li L , Ruan W , Zhang Y , Caruana E
Published: October 2013

Recruitment and retention are of paramount importance to medical radiation science (MRS) as a profession. There is a strong demand for MRS practitioners which is expected to continue as the population ages. This study aimed to examine demographic data, factors relating to the career choice of MRS, and future work or study plans of first year MRS students. Questionnaires were distributed to 83 first year students, currently enrolled in MRS at the University of Sydney. A total of 73 completed questionnaires were received. This sample included 30 diagnostic radiography students, 24 nuclear medicine students and 19 radiation therapy students. The top three factors that influenced students' career choices was wanting to help others, followed by wanting to work in a healthcare field, then wanting to work with technology. The most common source of students' career information was family members, friends and health professionals. Among the students, 68.5% were aware of advancement opportunities in their stream of MRS. About half of the students planned to specialise or undertake postgraduate study in MRS, and 39.7% planned to study another degree after graduating. The results of this study indicated that many students chose MRS as a career with the goal of helping others. The most frequently reported source through which the students first heard about the profession was personal contacts. Furthermore, about half of the students were interested in further study. This information can be used by professional organisations, educational programs, or employers to assist in recruitment and retention strategies of MRS students.
Critical appraisal of quantitative and qualitative research literature
Authors: Smith Tony
Published: October 2013

Critical appraisal of research articles can be used to inform the design of new research studies. It can also be used by clinicians who wish to improve service quality by using the best available evidence to inform their practice. This paper describes a broad framework of critical appraisal of published research literature that covers both quantitative and qualitative methodologies.

The aim is the heart of a research study. It should be robust, concisely stated and specify a study factor, outcome factor(s) and reference population. Quantitative study designs, including sampling methods, can be ranked in order of the quality of the evidence they produce, with randomised control trials being ranked as level 1. The strength of evidence from qualitative research studies depends on the degree of rigour used in data collection and analysis, using techniques like theoretical sampling, triangulation and participant validation. Whatever the study design, it must be appropriate to address the aim of the study.

In critically appraising all research papers, there is a need to reflect on how well the conclusions flow logically from the results of the analysis and answer the original research question and how well the research applies to the population we are interested in.
Exploring radiographers' attitudes to mandatory CPD in the United Kingdom and New Zealand
Authors: Henwood SM , Yielder J , Flinton D
Published: October 2013

Introduction: This paper reports the first phase of a two‐phase longitudinal study which explored the attitudes of radiographers in two countries (UK and New Zealand) towards CPD, before and after the introduction of a mandatory CPD policy. In addition, this paper outlines in brief the planned phase two of the project, which will be undertaken to assess whether attitudes change over time, following the introduced mandate. Methods: 1739 radiographers across both countries were approached via a survey using a written questionnaire with quantitative and qualitative components endorsed by the relevant professional body in each country (Society of Radiographers and the New Zealand Institute of Medical Radiation Technologists). The questionnaire was statistically analysed using t‐tests. In addition, the qualitative components were analysed thematically, to add depth and explanations to the findings. This paper presents the results, focusing especially on the qualitative data in order to fully explore the attitudes demonstrated. Results: The results of the study showed that a degree of apathy surrounded CPD participation, despite the professional expectation that staff be CPD active. On an individual level, radiographers self reported a low level, or a complete lack of formal recording of CPD. A number of barriers were identified, which were perceived by participants to restrict their CPD activity, including, of particular note, poor staffing levels and lack of employer support. Radiographers in both countries appeared to have a narrow understanding of what is perceived to constitute CPD, with an apparent focus on formal, attendance‐based activities. Less formal, on‐the‐job activities were not always considered as CPD by participants in this study. Conclusion: This study outlined a range of factors which impact on attitudes towards CPD, with many similarities in findings across both countries represented. A lack of intrinsic motivation was demonstrated, which is perceived to hamper active participation in CPD. There was a desire for personal benefit from CPD participation to be evident, in order to motivate individuals to get actively involved. The complexity of the current working environment was outlined, with acknowledgement that the mandatory policy towards CPD is not the only factor affecting participation. While further research will be required to examine the impact of all the variables affecting CPD, the results of this study may allow individuals and managers to begin to interact with CPD participation in order to attempt to increase the level and effectiveness of learning in practice.
Evaluation of a Sinmed shoulder support cushion for head and neck immobilisation
Authors: Brown E
Published: October 2013

Purpose: Accuracy and reproducibility of patient positioning is a central issue in the successful delivery of radiation therapy treatment. As treatment techniques become increasingly conformal, this issue has become ever more important. With the recent implementation of Intensity Modulated Radiation Therapy (IMRT) for head and neck patients, the Princess Alexandra Hospital Radiation Oncology Department has been investigating optimal immobilisation techniques for these patients. Methods: As part of this investigation, the department has recently trialled the inclusion of a modified Sinmed shoulder support cushion (CIVCO Medical Solutions, Kalona IA, USA) as part of the standard positioning protocol for head and neck patients. After trialling this piece of equipment on a small group of patients, an evaluation was undertaken to assess its effect on patient positioning accuracy. This evaluation consisted of electronic portal imaging assessment and collation of observations from treatment and planning staff. Results: No major differences were found between the positioning accuracy achieved for patients positioned with the support cushion in comparison to those positioned as per departmental protocol. Furthermore, trends were noted that indicated the support cushion actually decreased the level of positioning accuracy that was achieved. Staff observation demonstrated that the support cushion was not easy to use and contributed to problematic shell fitting in daily practice. Conclusion: As a result, the shoulder support cushion has not been implemented as part of the department's protocol for head and neck patient positioning with its use being limited to those patients who would most benefit from its inclusion due to anatomical restrictions.
Assessment of competency in radiography students — a new approach
Authors: Kilgour A J
Published: October 2013

The assessment of the clinical performance and clinical competence of radiography students is problematic for many reasons, including the following:

Significant variations between clinical centres in how students are assessed

Internal variations within larger clinical centres, depending on who completes the assessment forms

Clinical supervisors being uncomfortable with failing poorly performing students

Different interpretations among supervisors as to what constitutes competence

Confusion amongst supervisors who accept students from more than one university, due to variations in assessment paperwork.

A national assessment tool has been designed and implemented in radiation therapy. Other disciplines to develop a national assessment tool in recent times have included speech pathology and physiotherapy. The discussion that follows describes the first stage of a project to develop a national assessment framework, including a national assessment tool, for the diagnostic radiography profession.

The first stage of this project to develop a national assessment framework is a literature search, and this paper is based on the preliminary findings of this search. The aims of the search were to identify:

The fundamental principles of assessment in higher education

Factors arising from these principles that must be considered when designing a clinical assessment tool

Articles were sourced using Educational Resources Information Centre (ERIC), and were chosen based on their relevance to the topic. Some were sourced directly from their authors. Each article was summarised, and sorted into major categories using NVivo8™ (QSR International Pty Ltd, Doncaster, Victoria, Australia) qualitative data analysis software. These categories were: Function of education; issues related to assessment; types of knowledge and understanding; constructive alignment; teacher's role; competence; assessment (formative vs. summative and analytic vs. holistic); criterion and standards referencing; professional judgment. This was followed by a summary of the major categories.
Low‐temperature degradation of a Y‐TZP ceramic after surface treatments
Authors: Amaral Marina , Valandro Luiz Felipe , Bottino Marco A. , Souza Rodrigo O. A.
Published: October 2013

The purpose of this study was to evaluate the influence of zirconia surface treatments on low‐temperature degradation (LTD). Disc‐shaped specimens were subjected to one of four surface treatments, denoted as C (control—no surface treatment), Si (air abrasion with 30 µm silica‐modified alumina particles), Al (air abrasion with 30 µm alumina particles), and Gr (grinding with 120 grit diamond discs). Half of the samples were submitted to autoclave treatment for 12 h (127°C, 1.5 bar). Samples were characterized by x‐ray diffraction and profilometer analysis and were subjected to biaxial flexural strength test. All of the groups exhibited an increase in the amount of monoclinic phase (m‐phase) after LTD. The t→m transformation was remarkable for the specimens from the C group, which also exhibited a significant increase in strength. The Gr group also exhibited an increase in strength but lower initial roughness, which probably suppressed LTD on the zirconia surface. The specimens subjected to air abrasion exhibited higher initial amounts of m‐phase and a small increase in m‐phase after LTD; the strength was not affected in these groups. The effects of LTD were different with each surface treatment applied. Apparently, LTD may be suppressed by smoother surfaces or the presence of an initial amount of m‐phase on zirconia surface. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1387–1392, 2013.
Factors Controlling the Role of Zn and Reactivity of Zn‐bound Cysteines in Proteins: Application to Drug Target Discovery
Authors: Lee Yu‐Ming , Lin Yeh‐Fon , Lim Carmay
Published: October 2013

Zinc is an element essential to all forms of life. It can play a predominantly catalytic role or a exclusively structural role in proteins. Here, we provide an overview of important structural and catalytic Zn metalloproteins and highlight the key features distinguishing structural Zn sites from catalytic Zn sites. We elucidate why Zn can assume dual roles in proteins and provide ways to distinguish catalytic Zn sites from structural Zn sites and guidelines for targeting these Zn sites in drug target proteins. We also elucidate why the Zn‐bound cysteines in certain structural Zn‐sites are reactive and how they may be distinguished from inert Zn‐bound cysteines.
Neighborhoods in Maximum Packings of 2Kn and Quadratic Leaves of Triple Systems
Authors: Chaffee Joe , Rodger C. A.
Published: October 2013

In this paper, two related problems are completely solved, extending two classic results by Colbourn and Rosa. In any partial triple system of , the neighborhood of a vertex v is the subgraph induced by . For (mod 3) with , it is shown that for any 2‐factor F on or vertices, there exists a maximum packing of with triples such that F is the neighborhood of some vertex if and only if , thus extending the corresponding result for the case where or 1 (mod 3) by Colbourn and Rosa. This result, along with the companion result of Colbourn and Rosa, leads to a complete characterization of quadratic leaves of λ‐fold partial triple systems for all , thereby extending the solution where by Colbourn and Rosa.
Preseismic ionospheric electron enhancements revisited
Authors: Heki Kosuke , Enomoto Yuji
Published: October 2013

Possible enhancement of ionospheric Total Electron Content (TEC) immediately before the 2011 Tohoku‐oki earthquake (Mw9.0) has been reported by Heki (2011). Critical responses to it often come in two stages; they first doubt the enhancement itself and attribute it to an artifact. Second (when they accept the enhancement), they doubt the significance of the enhancement among natural variability of space weather origin. For example, Kamogawa and Kakinami (2013) attributed the enhancement to an artifact falsely detected by the combined effect of the highly variable TEC under active geomagnetic condition and the occurrence of a tsunamigenic ionospheric hole. Here we closely examine the time series of vertical TEC before and after the 2011 Tohoku‐oki earthquake. We first demonstrate that the tsunami did not make an ionospheric hole, and next confirm the reality of the enhancement using data of two other sensors, ionosonde and magnetometers. The amplitude of the preseismic TEC enhancement is within the natural variability, and its snapshot resembles to large‐scale traveling ionospheric disturbances. However, distinction could be made by examining their propagation properties. Similar TEC anomalies occurred before all the M ≥ 8.5 earthquakes in this century, suggesting their seismic origin.
Synoptic and dynamical analysis of subtropical cyclone Anita (2010) and its potential for tropical transition over the South Atlantic Ocean
Authors: Dias Pinto João Rafael , Reboita Michelle Simões , da Rocha Rosmeri Porfírio
Published: October 2013

Subtropical cyclogenesis and tropical transitions (TT) over the South Atlantic Ocean only received attention after the first documented Hurricane Catarina occurred close to the southern Brazilian coast in March 2004. However, due to the lack of studies in this part of the Atlantic Ocean, it is still unclear what the main environmental conditions and dynamical processes associated with TT or even subtropical cyclogenesis are over the region. This study presents a synoptic and dynamical analysis of the subtropical cyclone Anita which occurred in March 2010 near the Brazilian coast. This system started as a pure subtropical cyclone, evolved to a condition favorable to TT, later developed into a cold‐core structure, and decayed as an extratropical cyclone. During the period favorable for TT, the turbulent heat fluxes (latent plus sensible) from the ocean decreased, and Anita started interacting with another extratropical disturbance, preventing the TT to happen. This interaction, in turn, increased the vertical wind shear, allowed the extratropical transition to occur, and promoted the westward displacement of Anita to colder waters, thus decreasing the turbulent heat fluxes. The results suggest that the combination of a dipole blocking pattern aloft, with contribution from barotropic energy conversions, and strong turbulent fluxes is an important ingredient for tropical storm development. Hybrid storms in such environmental conditions can be one form of precursors of hurricanes over the South Atlantic.
A multitower measurement network estimate of California's methane emissions
Authors: Jeong Seongeun , Hsu Ying‐Kuang , Andrews Arlyn E. , Bianco Laura , Vaca Patrick , Wilczak James M. , Fischer Marc L.
Published: October 2013

We present an analysis of methane (CH4) emissions using atmospheric observations from five sites in California's Central Valley across different seasons (September 2010 to June 2011). CH4 emissions for spatial regions and source sectors are estimated by comparing measured CH4 mixing ratios with transport model (Weather Research and Forecasting and Stochastic Time‐Inverted Lagrangian Transport) predictions based on two 0.1° CH4 (seasonally varying “California‐specific” (California Greenhouse Gas Emission Measurements, CALGEM) and a static global (Emission Database for Global Atmospheric Research, release version 42, EDGAR42)) prior emission models. Region‐specific Bayesian analyses indicate that for California's Central Valley, the CALGEM‐ and EDGAR42‐based inversions provide consistent annual total CH4 emissions (32.87 ± 2.09 versus 31.60 ± 2.17 Tg CO2eq yr−1; 68% confidence interval (CI), assuming uncorrelated errors between regions). Summing across all regions of California, optimized CH4 emissions are only marginally consistent between CALGEM‐ and EDGAR42‐based inversions (48.35 ± 6.47 versus 64.97 ± 11.85 Tg CO2eq), because emissions from coastal urban regions (where landfill and natural gas emissions are much higher in EDGAR than CALGEM) are not strongly constrained by the measurements. Combining our results with those from a recent study of the South Coast Air Basin narrows the range of estimates to 43–57 Tg CO2eq yr−1 (1.3–1.8 times higher than the current state inventory). These results suggest that the combination of rural and urban measurements will be necessary to verify future changes in California's total CH4 emissions.
Visible‐near‐infrared reflectance spectroscopy of volcanic acid‐sulfate alteration in Nicaragua: Analogs for early Mars
Authors: Marcucci Emma C. , Hynek Brian M. , Kierein‐Young Kathryn S. , Rogers K. L.
Published: October 2013

Acid‐sulfate weathering at Nicaraguan hydrothermal sites Cerro Negro, Momotombo, and Telica volcanoes and Hervidores de San Jacinto mudpots was characterized as an analog for similar processes that likely operated on early Mars. In situ mineralogical analyses were conducted with a field portable visible near‐infrared spectrometer for comparison to similar Martian data sets. Three classes of alteration minerals were identified: sulfates (gypsum and natroalunite), oxides/hydroxides (hematite and goethite), and phyllosilicates (kaolinite/halloysite, montmorillonite, and saponite), as well as elemental sulfur and hydrated silica phases. Our sites had similar suites of minerals, but frequencies varied with location. The results of this field campaign allow inferences regarding the paleo‐environmental conditions that were likely present at similar relic hydrothermal sites identified on Mars. In particular, sulfates and phyllosilicates could have coevolved under hydrothermal conditions at Noctis Labyrinthus as is seen in Nicaragua. Fe/Mg smectites were detected in areas with pH of 3–4. Alunite spectra at Terra Sirenum demonstrated mineral mixing effects on spectroscopy. Mineral mixing can cause uncertainties in spectral identification due to a dominant spectrum, such as iron minerals, masking another or the suppression of weaker bands. When viewed from orbit, our field sites would likely be dominated by hydrated silica and Mars sites, such as one in Syrtis Major, could have a more diverse mineralogy than the data reveal. Concentrated amorphous silica, such as at Gusev crater, can result from acidic fumarolic activity, while Mg sulfates may indicate a lack of reworking by water. This field spectroscopy study helps confirm and provide insight into hydrothermal processes on ancient Mars.
Physical ecology of hypolithic communities in the central Namib Desert: The role of fog, rain, rock habitat, and light
Authors: Warren‐Rhodes Kimberley A. , McKay Christopher P. , Boyle Linda Ng , Wing Michael R. , Kiekebusch Elsita M. , Cowan Don A. , Stomeo Francesca , Pointing Stephen B. , Kaseke Kudzai F. , Eckardt Frank , Henschel Joh R. , Anisfeld Ari , Seely Mary , Rhodes Kevin L.
Published: October 2013

Hypolithic microbial communities are productive niches in deserts worldwide, but many facets of their basic ecology remain unknown. The Namib Desert is an important site for hypolith study because it has abundant quartz rocks suitable for colonization and extends west to east across a transition from fog‐ to rain‐dominated moisture sources. We show that fog sustains and impacts hypolithic ecology in several ways, as follows: (1) fog effectively replaces rainfall in the western zone of the central Namib to enable high (≥95%) hypolithic abundance at landscape (1–10 km) and larger scales; and (2) high water availability, through fog (western zone) and/or rainfall (eastern zone), results in smaller size‐class rocks being colonized (mean 6.3 ± 1.2 cm) at higher proportions (e.g., 98% versus approximately 3%) than in previously studied hyperarid deserts. We measured 0.1% of incident sunlight as the lower limit for hypolithic growth on quartz rocks in the Namib and found that uncolonized ventral rock surfaces were limited by light rather than moisture. In situ monitoring showed that although rainfall supplied more liquid water (36 h) per event than fog (mean 4 h), on an equivalent annual basis, fog provided nearly twice as much liquid water as rainfall to the hypolithic zone. Hypolithic abundance reaches 100% at a mean annual precipitation (MAP) of approximately 40–60 mm, but at a much lower MAP (approximately 25 mm) when moisture from fog is available.
Comparative evaluation of the diagnostic potential of recombinant envelope proteins and native cell culture purified viral antigens of Chikungunya virus
Authors: Khan Mohsin , Dhanwani Rekha , Kumar Jyoti S. , Rao P.V. Lakshmana , Parida Manmohan
Published: October 2013

Despite the fact that Chikungunya resurgence is associated with epidemic of unprecedented magnitude, there are challenges in the field of its clinical diagnosis. However, serological tests in an ELISA format provide a rapid tool for the diagnosis of Chikungunya infection. Indeed, ELISAs based on recombinant proteins hold a great promise as these methods are cost effective and are free from the risk of handling biohazardous material. In this study, the performance of recombinant CHIKV antigens was compared in various ELISA formats for the diagnosis of Chikungunya. Two recombinant antigens derived from the envelope proteins of Chikungunya virus were prepared and evaluated by comparing their competence for detecting circulating antibodies in serum samples of patients infected with CHIKV using MAC‐ELISA and indirect IgM‐ELISA. The efficacy of the recombinant antigens was also compared with the native antigen. The indirect antibody capture IgM microplate ELISA revealed ≥90% concordance with the native antigen in detecting the CHIKV specific IgM antibodies whereas the recombinant antigen based MAC‐ELISA showed 100% specificity. The recombinant antigens used in this study were effective and reliable targets for the diagnosis of CHIKV infection and also provide an alternative for native antigen use which is potentially biohazardous. J. Med. Virol. 86:1169–1175, 2014. © 2013 Wiley Periodicals, Inc.
Neural and physiological responses to a cold pressor challenge in healthy adolescents
Authors: Richardson Heidi L. , Macey Paul M. , Kumar Rajesh , Valladares Edwin M. , Woo Mary A. , Harper Ronald M.
Published: October 2013

Abnormal autonomic function is common in pediatric diseases. Assessment of central mechanisms underlying autonomic challenges may reveal vulnerabilities antecedent to system failure. Our objective was to characterize central markers and physiological responses to a cold pressor challenge in normal children as a critical step for establishing such screening. We performed functional magnetic resonance imaging (fMRI) and collected physiological measures during cold application to the foot in 24 healthy adolescents (15.5 ± 0.4 years, 13 male). The protocol included a 120‐sec baseline, 120‐sec right‐foot cold water immersion (4°C), and 120‐sec recovery. Analyses included heart rate (HR) cross‐correlations with fMRI signals. Cold application increased HR 13% 5–7 sec after onset, which remained elevated throughout the challenge. Respiratory rate transiently increased (peak 22%), then declined (nadir 12% below baseline), before normalizing at 75 sec. Cold onset rapidly increased somatosensory cortex and medullary signals, which fell after 25 sec. Right anterior insular cortex signals increased early, followed after 20 sec by the left anterior insula, with HR declining 8 sec later. Amygdalae signals also rose, but signals declined in the posterior cingulate cortex, caudate nucleus, hippocampus, and hypothalamus. Declining signals appeared late in the cerebellar fastigial nuclei (60–120 sec), and in the pons and thalamus. Somatosensory cortex, fastigial nuclei, and hypothalamic responses were principally left‐sided, with bilateral responses elsewhere. Late left anterior insula responses likely underlie the HR decline; the late cerebellar pattern may modulate recovery. The laterality, timing, and amplitude of normative responses and rostral response differentiation indicate the complex integration of adolescent autonomic processing and provide indices for pathological comparisons. © 2013 Wiley Periodicals, Inc.
30‐Arcsecond monthly climate surfaces with global land coverage
Authors: Mosier Thomas M. , Hill David F. , Sharp Kendra V.
Published: October 2013

Monthly total precipitation and mean temperature climate surfaces, gridded to 30‐arcseconds (≈1 km at the equator) and available for all global land areas, are presented. These datasets are generated with a Delta downscaling method, using the 30‐arcsecond WorldClim climatologies to scale monthly anomaly grids. For monthly mean temperature, the anomalies are constructed from both the Climate Research Unit (CRU) and Willmott & Matsuura (W&M) 0.5 degree time‐series datasets, whereas for monthly precipitation Global Precipitation Climatology Centre (GPCC) data are also used. The 0.5 degree anomalies are then interpolated to the 30‐arcsecond resolution. Use of piecewise cubic Hermite interpolating polynomials (PCHIP) to interpolate the anomaly grids results in more physically representative Delta downscaled surfaces, compared to bilinear and cubic spline interpolation. The Delta downscaled products are compared to Global Historical Climatology Network (GHCN) station records for six test regions distributed globally. In this analysis, the Delta grids produced using the W&M time‐series dataset perform better than grids produced using GPCC or CRU. Using Oregon, USA as a test region, the Delta downscaled datasets are compared to the Parameter‐elevation Regressions on Independent Slopes Model (PRISM) datasets. For monthly precipitation, PRISM performs better than each of the three Delta downscaled datasets, but for mean temperature both Delta downscaled datasets outperform PRISM. Through computing the Pearson product–moment correlation coefficient between GHCN station delineated errors in the WorldClim climatologies and the Delta downscaled W&M data, it is shown that performance of the Delta grids corresponds strongly to performance of the reference climatologies. Therefore, future improvement of the 30‐arcsecond Delta grids described in this article is strongly tied to advances in the high‐resolution climatological data for all global land surfaces. The Delta downscaled datasets discussed herein are open‐source and freely distributed at http://www.globalclimatedata.org.
Performance of an empirical bias‐correction of a high‐resolution climate dataset
Authors: Bennett James C. , Grose Michael R. , Corney Stuart P. , White Christopher J. , Holz Gregory K. , Katzfey Jack J. , Post David A. , Bindoff Nathaniel L.
Published: October 2013

We describe the method and performance of a bias‐correction applied to high‐resolution (˜10 km) simulations from a stretched‐grid Regional Climate Model (RCM) over Tasmania, Australia. The bias‐correction is a quantile mapping of empirical cumulative frequency distributions. Corrections are applied at a daily time step to five variables: rainfall, potential evaporation (PE), solar radiation, maximum temperature and minimum temperature. Corrections are calculated independently for each season.

We show that quantile mapping of empirical distributions can be highly effective in correcting biases in RCM outputs. Cross‐validation shows biases are effectively reduced across the range of cumulative frequency distributions, with few exceptions. The bias‐correction is not as effective at correcting biases for values at or near zero (e.g. in rainfall simulations), although even here the bias‐correction improves biases evident in the uncorrected simulations. In addition, the bias‐correction improves frequency characteristics of variables such as the number of rain days.

We use a detrending technique to apply the bias‐correction to 140‐year time series of RCM variables. We show that the bias‐correction effectively preserves long‐term changes (e.g. to the mean and variance) to variables projected by the uncorrected RCM simulations. Correlations between key variables are also largely preserved, thus the bias‐corrected outputs reflect the dynamics of the underlying RCM. However, the bias‐corrected simulations still exhibit some of the deficiencies of the RCM simulations, e.g. the tendency to underestimate the magnitude and duration of large, multi‐day rain events, and the tendency to underestimate the duration of dry spells.

The bias‐corrected simulations for six downscaled GCMs for the A2 and B1 emissions scenarios are available to researchers from http://www.tpac.org.au.