70 results on '"Neil Whitehead"'
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2. Investigating Airplane Crash Data with Watson Analytics and Cognos Analytics.
- Author
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Taiyo Miyamoto, Neil Whitehead, and Emanuel Santos
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- 2020
- Full Text
- View/download PDF
3. Dark Shamans and the Shamanic State: Sorcery and Witchcraft as Political Process in Guyana and the Venezuelan Amazon
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Silvia Vidal and Neil Whitehead
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- 2020
4. 1 Introduction: Dark Shamanism
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Neil Whitehead and Robin Wright
- Published
- 2020
5. RETRACTED: Effects of Therapy on Religious Men Who Have Unwanted Same-Sex Attraction
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Paul L Santero, Neil Whitehead, and Dolores Ballesteros
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Sexual identity ,030219 obstetrics & reproductive medicine ,Sexual attraction ,Health Policy ,media_common.quotation_subject ,Self-esteem ,06 humanities and the arts ,0603 philosophy, ethics and religion ,medicine.disease ,Mental health ,Substance abuse ,03 medical and health sciences ,Philosophy ,0302 clinical medicine ,Harm ,medicine ,Sexual orientation ,060301 applied ethics ,Homosexuality ,Psychology ,media_common ,Clinical psychology - Abstract
The American Psychological Association and other organizations have formally claimed that sexual orientation change therapies should not be used because they are probably ineffective and may cause harm. A survey asking for negative and positive experiences of 125 men with active lay religious belief who went through sexual orientation change efforts (SOCE) strongly conflicted with those claims. In our study, most of those who participated in group or professional help had heterosexual shifts in sexual attraction, sexual identity and behavior with large statistical effect sizes, similarly moderate-to-marked decreases in suicidality, depression, substance abuse, and increases in social functioning and self-esteem. Almost all harmful effects were none to slight. Prevalence of help or hindrance, and effect size, were comparable with those for conventional psychotherapy for unrelated mental health issues. Judged by this survey, these therapies are very beneficial for lay religious people, but no Catholic pries...
- Published
- 2020
6. Blue sky at midnight – earthquake lightning
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Ülkü Ulusoy and Neil Whitehead
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Daytime ,media_common.quotation_subject ,Earthquake light,Chile,Ecuador,Mexico,Napa Valley,New Zealand,Peru,Romania,Turkey ,Mühendislik ,Storm ,law.invention ,Mercury-vapor lamp ,Green flash ,Engineering ,law ,Color changes ,Midnight ,Sky ,General Earth and Planetary Sciences ,Earthquake light ,Geology ,Seismology ,media_common - Abstract
Earthquake light, emerging from the ground as flashes at night (neglecting other more minor forms), usually has a whitehemispherical center and blue outer part. The blue resembles daytime blue sky. Its existence is increasingly verified, with about 80 videoson the web to mid-2017. However, the light must be differentiated from power-grid faults, so sound/color/form/length criteria weredeveloped in this paper through examination of many videos. Light should be coseismic (i.e. when the S-waves arrive), hemispherical,not during a storm, less than 1 s long, without fire or smoke, and without many rapid color changes. Warnings about camera artifactsare included. This light accompanied two recent earthquakes: M7.8 November 14, 2016, New Zealand, and M8.1 September 8, 2017,Mexico. Definite green flash earthquake light has only been caught once on video and it is shown that others are sometimes electricaloverload of mercury vapor lamps, or difficulty with classifying pale turquoise flashes that are only slightly more green than blue. Threeseparate frames from videos (NZ, Turkey, and Ecuador) have views actually within the blue light. These data exemplify the Freundprinciple of positive charge production from quartz by high stress-rate, then charge separation and expulsion to the ground surface andcreation of light, but the hypotheses of quartz piezoelectricity or voltages from fracture mechanisms are not accepted.
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- 2018
7. Establishing Drug Discovery and Identification of Hit Series for the Anti-apoptotic Proteins, Bcl-2 and Mcl-1
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Pawel Dokurno, R. Harris, Patrick Casara, James Edward Paul Davidson, Olivier Geneste, Julia Smith, Douglas S. Williamson, Natalia Matassova, Yikang Wang, Allan M. Jordan, Stephen D. Roughley, András Kotschy, Roderick E. Hubbard, Jerome Stark, John A. Hickman, Chen I-Jen, Ben Davis, James Brooke Murray, C. Pedder, Walmsley Claire, Thierry Le Diguarher, Neil Whitehead, Stuart C. Ray, and Christopher John Graham
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Series (mathematics) ,Chemistry ,Drug discovery ,General Chemical Engineering ,Isothermal titration calorimetry ,General Chemistry ,Computational biology ,Small molecule ,Article ,Anti-Apoptotic Proteins ,lcsh:Chemistry ,Heteronuclear molecule ,lcsh:QD1-999 ,Surface plasmon resonance - Abstract
We describe our work to establish structure- and fragment-based drug discovery to identify small molecules that inhibit the anti-apoptotic activity of the proteins Mcl-1 and Bcl-2. This identified hit series of compounds, some of which were subsequently optimized to clinical candidates in trials for treating various cancers. Many protein constructs were designed to identify protein with suitable properties for different biophysical assays and structural methods. Fragment screening using ligand-observed NMR experiments identified several series of compounds for each protein. The series were assessed for their potential for subsequent optimization using 1H and 15N heteronuclear single-quantum correlation NMR, surface plasmon resonance, and isothermal titration calorimetry measurements to characterize and validate binding. Crystal structures could not be determined for the early hits, so NMR methods were developed to provide models of compound binding to guide compound optimization. For Mcl-1, a benzodioxane/benzoxazine series was optimized to a Kd of 40 μM before a thienopyrimidine hit series was identified which subsequently led to the lead series from which the clinical candidate S 64315 (MIK 665) was identified. For Bcl-2, the fragment-derived series were difficult to progress, and a compound derived from a published tetrahydroquinone compound was taken forward as the hit from which the clinical candidate (S 55746) was obtained. For both the proteins, the work to establish a portfolio of assays gave confidence for identification of compounds suitable for optimization.
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- 2019
8. Are any public-reported earthquake precursors valid?
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Motoji Ikeya, H. Asahara, Ü. Ulusoy, Neil Whitehead, Quantum Geophysics Laboratory, Osaka University [Osaka], Department of Physics Engineering, and Hacettepe University = Hacettepe Üniversitesi
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,lcsh:GE1-350 ,010504 meteorology & atmospheric sciences ,Wishful thinking ,05 social sciences ,lcsh:QE1-996.5 ,lcsh:Geography. Anthropology. Recreation ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,01 natural sciences ,lcsh:TD1-1066 ,Test (assessment) ,lcsh:Geology ,lcsh:G ,General Earth and Planetary Sciences ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,lcsh:Environmental technology. Sanitary engineering ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Psychology ,Seismology ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,Cognitive psychology - Abstract
This article examines retrospective public-supplied precursor reports statistically, and confirms published hypotheses that some alleged precursors within 100km and within a day prior to the large 1995 Kobe and 1999 Izmit earthquakes, may be valid. The confirmations are mostly at the p
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- 2018
9. S55746 is a novel orally active BCL-2 selective and potent inhibitor that impairs hematological tumor growth
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Patrick Casara, James Davidson, Audrey Claperon, Gaëtane Le Toumelin-Braizat, Meike Vogler, Alain Bruno, Maïa Chanrion, Gaëlle Lysiak-Auvity, Thierry Le Diguarher, Jérôme-Benoît Starck, Ijen Chen, Neil Whitehead, Christopher Graham, Natalia Matassova, Pawel Dokurno, Christopher Pedder, Youzhen Wang, Shumei Qiu, Anne-Marie Girard, Emilie Schneider, Fabienne Gravé, Aurélie Studeny, Ghislaine Guasconi, Francesca Rocchetti, Sophie Maïga, Jean-Michel Henlin, Frédéric Colland, Laurence Kraus-Berthier, Steven Le Gouill, Martin J.S. Dyer, Roderick Hubbard, Mike Wood, Martine Amiot, Gerald M Cohen, John A. Hickman, Erick Morris, James Murray, Olivier Geneste, Institut de Recherches Servier, Vernalis (R&D) Ltd, Institute for Experimental Cancer Research in Pediatrics, Goethe-Universität Frankfurt am Main, Institut de Recherches Internationales Servier [Suresnes] (IRIS), Novartis Institute of Biomedical Research, Oncology Drug Discovery, Regulation of Bcl2 and p53 Networks in Multiple Myeloma and Mantle Cell Lymphoma (CRCINA-ÉQUIPE 10), Centre de Recherche en Cancérologie et Immunologie Nantes-Angers (CRCINA), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA), Ernest and Helen Scott Haematological Research Institute, University of Leicester, Institute of Translational Medicine, University of Liverpool, Goethe-University Frankfurt, Institut de Recherches Internationales Servier [Suresnes] ( IRIS ), Regulation of Bcl2 and p53 networks in Multiple Myeloma and Mantle Cell Lymphoma ( CRCINA - Département NOHMAD - Equipe 10 ), Centre de recherche de Cancérologie et d'Immunologie / Nantes - Angers ( CRCINA ), Université d'Angers ( UA ) -Université de Nantes ( UN ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche en Santé de l'Université de Nantes ( IRS-UN ) -Centre hospitalier universitaire de Nantes ( CHU Nantes ) -Université d'Angers ( UA ) -Université de Nantes ( UN ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche en Santé de l'Université de Nantes ( IRS-UN ) -Centre hospitalier universitaire de Nantes ( CHU Nantes ), Université d'Angers (UA)-Université de Nantes (UN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Université d'Angers (UA)-Université de Nantes (UN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre hospitalier universitaire de Nantes (CHU Nantes), and Bernardo, Elizabeth
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0301 basic medicine ,apoptosis ,BCL-2 ,[SDV.CAN]Life Sciences [q-bio]/Cancer ,BH3-mimetics ,[ SDV.CAN ] Life Sciences [q-bio]/Cancer ,3. Good health ,inhibitor ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,[SDV.CAN] Life Sciences [q-bio]/Cancer ,Oncology ,030220 oncology & carcinogenesis ,hematological malignancies ,Research Paper - Abstract
International audience; Escape from apoptosis is one of the major hallmarks of cancer cells. The B-cell Lymphoma 2 (BCL-2) gene family encodes pro-apoptotic and anti-apoptotic proteins that are key regulators of the apoptotic process. Overexpression of the pro-survival member BCL-2 is a well-established mechanism contributing to oncogenesis and chemoresistance in several cancers, including lymphoma and leukemia. Thus, BCL-2 has become an attractive target for therapeutic strategy in cancer, as demonstrated by the recent approval of ABT-199 (Venclexta™) in relapsed or refractory Chronic Lymphocytic Leukemia with 17p deletion. Here, we describe a novel orally bioavailable BCL-2 selective and potent inhibitor called S55746 (also known as BCL201). S55746 occupies the hydrophobic groove of BCL-2. Its selectivity profile demonstrates no significant binding to MCL-1, BFL-1 (BCL2A1/A1) and poor affinity for BCL-XL. Accordingly, S55746 has no cytotoxic activity on BCL-XL-dependent cells, such as platelets. In a panel of hematological cell lines, S55746 induces hallmarks of apoptosis including externalization of phosphatidylserine, caspase-3 activation and PARP cleavage. Ex vivo, S55746 induces apoptosis in the low nanomolar range in primary Chronic Lymphocytic Leukemia and Mantle Cell Lymphoma patient samples. Finally, S55746 administered by oral route daily in mice demonstrated robust anti-tumor efficacy in two hematological xenograft models with no weight lost and no change in behavior. Taken together, these data demonstrate that S55746 is a novel, welltolerated BH3-mimetic targeting selectively and potently the BCL-2 protein.
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- 2018
10. Application of Off-Rate Screening in the Identification of Novel Pan-Isoform Inhibitors of Pyruvate Dehydrogenase Kinase
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Stephen Stokes, Patrick C. Mahon, Alan D. Robertson, Jalanie D’Alessandro, Paul Webb, Charles Parry, Lisa Baker, Natalia Matassova, Nicholas G. M. Davies, Sean McKenna, Andrew Massey, Rachel Parsons, Yikang Wang, Macias Alba, Paul Brough, Ben Davis, Michael Wood, Simon Bedford, Jonathan D. Moore, Christopher J. Northfield, Loic le Strat, Stephen D. Roughley, Daniel Maddox, Seema Chavda, James Brooke Murray, Allan E. Surgenor, Johannes W. G. Meissner, Terry Shaw, Heather Simmonite, Stefaniak Emma Jayne, Victoria Chell, Neil Whitehead, and Kirsten Brown
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0301 basic medicine ,Male ,Models, Molecular ,Pyruvate dehydrogenase lipoamide kinase isozyme 1 ,Pyruvate dehydrogenase kinase ,Pyruvate dehydrogenase phosphatase ,Protein Serine-Threonine Kinases ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Adenosine Triphosphate ,Cell Line, Tumor ,Drug Discovery ,Transferase ,Humans ,Protein Isoforms ,HSP90 Heat-Shock Proteins ,Phosphorylation ,Protein Kinase Inhibitors ,chemistry.chemical_classification ,Prostatic Neoplasms ,Pyruvate Dehydrogenase Acetyl-Transferring Kinase ,Hit to lead ,Molecular biology ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,030220 oncology & carcinogenesis ,Drug Design ,Molecular Medicine ,Adenosine triphosphate - Abstract
Libraries of nonpurified resorcinol amide derivatives were screened by surface plasmon resonance (SPR) to determine the binding dissociation constant (off-rate, kd) for compounds binding to the pyruvate dehydrogenase kinase (PDHK) enzyme. Parallel off-rate measurements against HSP90 and application of structure-based drug design enabled rapid hit to lead progression in a program to identify pan-isoform ATP-competitive inhibitors of PDHK. Lead optimization identified selective sub-100-nM inhibitors of the enzyme which significantly reduced phosphorylation of the E1α subunit in the PC3 cancer cell line in vitro.
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- 2017
11. Macroscopic anomalies before the September 2010 M = 7.1 earthquake in Christchurch, New Zealand
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Ü. Ulusoy and Neil Whitehead
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Quake (natural phenomenon) ,Telephone survey ,Geography ,General Earth and Planetary Sciences ,Seismology ,Aftershock ,Demography - Abstract
Previous published work after the Kobe and İzmit earthquakes (1995 and 1999, respectively) demonstrated some reported meteorological and animal behaviour precursors were valid. Predictions were freshly tested for the Christchurch earthquake (M = 7.1, 4 September 2010). An internet survey with nearly 400 valid replies showed relative numbers of reports in precursor categories the day before the quake, were statistically significantly different from those in the preceding three days (excess meteorological events and animal behaviour). The day before the quake, there was also altered relative precursor class occurrence within 56 km compared with further away. Both these confirmed the earlier published work. Owners were woken up by unique pet behaviour 12 times as often in the hour before the quake compared with other hours immediately before (statistically highly significant). Lost and Found pet reports were double normal the week before, and 4.5 times normal both the day before the quake, and 9 days before. (Results were again statistically significant). Unique animal behaviour before the quake was often repeated before the numerous aftershocks. These pet owners claimed an approximate 80% prediction reliability. However, a preliminary telephone survey suggested that animals showing any precursor response are a minority. Some precursors seem real, but usefulness seemed mostly restricted to 7 cases where owners were in, or near, a place of safety through disruptive pet behaviour, and one in which owners were diverted by a pet from being struck by falling fixtures. For a later 22 February 2011 M = 6.3 quake no reports of escape through warning by pets were recorded, which raises serious questions whether such prediction is practically useful, because lives claimed saved are extremely low compared with fatalities. It is shown the lost-pet statistics dates, correspond to ionospheric anomalies recorded using the GPS satellite system and geomagnetic disturbance data, and claimed as precursory. The latter more objective measurements may be the way of the future, but improved statistical treatment should include observations over longer periods of time without earthquakes.
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- 2013
12. A preliminary study on the use of 10Be in forensic radioecology of nuclear explosion sites
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Robert G. Ditchburn, Masaharu Hoshi, Satoru Endo, A. Zondervan, Kimio Tanaka, Neil Whitehead, Toshihiro Takatsuji, and Satoshi Fukutani
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Nuclear explosion ,medicine.medical_specialty ,Nuclear fission product ,Health, Toxicology and Mutagenesis ,Explosions ,Mass Spectrometry ,law.invention ,Nuclear physics ,Radioecology ,Japan ,law ,medicine ,Environmental Chemistry ,Neutron ,Waste Management and Disposal ,Nuclear Warfare ,Ecology ,Chemistry ,Forensic Sciences ,Radiochemistry ,General Medicine ,Nuclear reactor ,Pollution ,Nuclear fission ,Environmental radioactivity ,Beryllium ,Accelerator mass spectrometry - Abstract
Cosmogenic (10)Be, known for use in dating studies, unexpectedly is also produced in nuclear explosions with an atom yield almost comparable to (e.g.) (137)Cs. There are major production routes via (13)C(n, alpha)(10)Be, from carbon dioxide in the air and the organic explosives, possibly from other bomb components and to a minor extent from the direct fission reaction. Although the detailed bomb components are speculative, carbon was certainly present in the explosives and an order of magnitude calculation is possible. The (n, alpha) cross-section was determined by irradiating graphite in a nuclear reactor, and the resulting (10)Be estimated by Accelerator Mass Spectrometry (AMS) giving a cross-section of 34.5+/-0.7mb (6-9.3MeV), within error of previous work. (10)Be should have applications in forensic radioecology. Historical environmental samples from Hiroshima, and Semipalatinsk (Kazakhstan) showed two to threefold (10)Be excesses compared with the background cosmogenic levels. A sample from Lake Chagan (a Soviet nuclear cratering experiment) contained more (10)Be than previously reported soils. (10)Be may be useful for measuring the fast neutron dose near the Hiroshima bomb hypocenter at neutron energies double those previously available.
- Published
- 2008
13. Iodine-129 measurements in soil samples from Dolon village near the Semipalatinsk nuclear test site
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Hidehisa Kawamura, Masaharu Hoshi, Neil Whitehead, Aya Sakaguchi, Kenichi Tanaka, Sergey Shinkarev, B. I. Gusev, Hikaru Amano, Masayoshi Yamamoto, Kazbek N. Apsalikov, Junpei Tomita, Satoshi Fukutani, Tetsuji Imanaka, Satoru Endo, and Hisao Kawamura
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Radiation ,Soil test ,Isotope ,Radiochemistry ,Biophysics ,chemistry.chemical_element ,Fission product yield ,Iodine ,Fast fission ,Kazakhstan ,Mass Spectrometry ,Iodine Radioisotopes ,chemistry ,Cesium Radioisotopes ,Atom ,Soil Pollutants, Radioactive ,Nuclear test ,General Environmental Science ,Accelerator mass spectrometry ,Nuclear Warfare - Abstract
Dolon village, located about 60 km from the border of the Semipalatinsk nuclear test site, is known to be heavily contaminated by the first USSR atomic bomb test in August 1949. Soil samples around Dolon were taken in October 2005 in an attempt to evaluate internal thyroid dose arising from incorporation of radioiodine isotopes (mainly (131)I). Iodine-129 in soil was measured by using the technique of accelerator mass spectrometry. The (129)I/(127)I atom ratios measured were in the range from 3.3 x 10(-9) to 3.3 x 10(-7). These values were within the range of the current background level ( approximately 10(-9) to 10(-7)) in the environment, including contributions from the global fallout of atmospheric nuclear tests and local fallout of nuclear facilities. The (129)I atom accumulated level in soil ranged from 1.28 x 10(13) to 1.59 x 10(14) atoms m(-2), the average (8.0 x 10(13)) of which was higher than the background level of (2-5) x 10(13). From the relationship between (129)I and( 137)Cs (corrected for background and decay from 1949 to 2005) accumulated levels, the background level of (129)I and the (129)I/(137)Cs ratio around Dolon were estimated to be (6.4 +/- 0.4) x 10(13) atoms m(-2) and 0.25 +/- 0.16, respectively. This (129)I/(137)Cs ratio is almost similar to the fission yield ratio for (239)Pu fast fission (0.24).
- Published
- 2008
14. AN ANTIBOY ANTIBODY? RE-EXAMINATION OF THE MATERNAL IMMUNE HYPOTHESIS
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Neil Whitehead
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Male ,Birth weight ,Physiology ,Antibodies ,Fetus ,Sex Factors ,Immune system ,Antigen ,Pregnancy ,medicine ,Birth Weight ,Humans ,Antigens ,Sexual differentiation ,biology ,Immunity ,Pregnancy Outcome ,Public Health, Environmental and Occupational Health ,General Social Sciences ,Sex Determination Processes ,medicine.disease ,Birth order ,biology.protein ,Female ,Birth Order ,Antibody - Abstract
SummaryThe maternal immune hypothesis (MIH) argues same sex attraction (SSA) results from maternal immune attack on fetal male-specific brain structures and involves the previous biological influence of elder brothers. One of the surveys supporting this is shown to be based on an unsuitable sample and to contain some strong contrary evidence. The hypothesis relies on at least four speculative ideas and there is evidence against each. (1) Likely immune response prevalence is too low compared with calculated SSA prevalence resulting from the fraternal birth order effect. (2) Testis immune attack would be more likely than brain attack but is not known. (3) Fetal brain structures are practically indistinguishable at birth and subsequent brain anatomical gender differentiation only occurs after birth when no attack is occurring. (4) The hypothesis also predicts unfavourable biology for late birth-order males but in fact the reverse is generally true, and neurological effects are very minor. Studies show aborted fetuses caused by likely maternal immune attack are predominantly girls rather than boys, which also argues against the theory. Studies on identical twins show that common factors such as uterine environment are only a small influence on SSA and post-natal idiosyncratic reactions and non-shared environmental factors are much larger influences.
- Published
- 2007
15. Origin of Earthquake Light Associated with Earthquakes in Christchurch, New Zealand, 2010-2011
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Neil Whitehead and Ü. Ulusoy
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lcsh:Geology ,Physics ,lcsh:QE1-996.5 ,General Earth and Planetary Sciences ,earthquake light ,earthquake precursors ,Cartography ,Humanities ,Earthquake light ,55 Ciencias de la tierra / Earth sciences and geology - Abstract
Earthquake light (EQL) mainly blue-white flashes from the ground, was observed coseismically during a NewZealand M7.1 earthquake, (4.47 am 4-Sep-2010 local time). A local production mechanism is most probable. The blue-white flash observations support the Freund et al. mechanism, i.e. shockwave disturbance creating electronic“holes” from ruptured peroxy bonds in quartz, and subsequent surface positive charge from the ground, followed by light emission during neutralization. Examination of video records shows the flash median length is about half a second and needs to be differentiated from the light during electricity supply short circuits. Observed ground-level white colors appear to result from very intense non-specific air ionization. Blue colors seem to be nitrogen emission with a short lifetime, succeeded by green oxygen emissions with longer lifetime followed by much lower intensity red. These were created by transient low-to-moderate voltages and probably include significant UV production.The maximum likely radiation dose is small, restricted to the skin, and equivalent at most to a few months natural background radiation. Calculations confirm the release of 222Rn is not the major mechanism for creating earthquake light, and would contribute minimal radiation dose. Other unique observations are: streamers of light changing from blue to green as they passed from west to east, vertical sheets of blue-green light from cracks in an asphalt road surface, created by local shockwaves and shearing forces, daylight observation by fishermen of rapid linear undersea travel of blue light seconds before a 2011 M6.0 aftershock, and a mid-day green-blue glow over nearby hills containing a fault zone, shortly before the further destructive M6.3 earthquake, (12.51 pm 22-Feb-2011). Origen de Luces de Terremoto Asociadas con los Terremotos de Christchurch, Nueva Zelanda, 2010-2011 son principalmente azul blancas y fueron cosísmicamente observadas durante un terremoto de magnitud 7.1 en Nueva Zelanda (4:47 a.m., 4 de septiembre de 2010, hora local). Es muy probable que el fenómeno haya sido producto de un mecanismo local. Las observaciones del destello azul blanco coinciden con el mecanismo de Freund y otros, esto es, la alteración de un movimiento sísmico que crea "agujeros" electrónicos a partir de lazos de ácido peroxi rotos en cuarzos, con carga positiva superficial consecuente del suelo, y seguida por la emisión de luz durante la neutralización. La revisión de grabaciones de video muestra que la duración del destello es de cerca de medio segundo y debe ser diferenciado de la luz generada por los cortos circuitos del fluido eléctrico. Los colores blancos observados a nivel del terreno parecen resultar de una intensa ionización aérea no específica. Los colores azules serían emisiones de nitrógeno con un corto período de duración, sucedidas por emisiones de oxígeno verde de mayor duración y seguidas por un rojo mucho menos intenso. Estos colores fueron creados por voltajes transitorios de bajo a moderados y probablemente incluyen una producción significativa de radiación ultravioleta. La cantidad de radiación máxima probable es pequeña, restringida a la piel, y equivalente a unos pocos meses de radiación natural regular. Los cálculos confirman que la liberación de 222Rn (Radón) no es el principal mecanismo para crear las luces de terremoto y que este contribuye con una mínima cantidad de radiación. Otras observaciones únicas hablan de rayos de luz que cambian de azul a verde mientras van de oeste a este, de cortinas verticales de luz azul verdosa que emergen de grietas en la carretera, creadas por movimientos sísmicos y fuerzas de corte; de observaciones de pescadores a luz del día del trayecto subacuático, rápido y lineal, de una luz azul antes del movimiento sísmico de magnitud 6.0 de 2011, y de un resplandor verde azuloso a mediodía sobre las colinas cercanas a una zona de fallas momentos antes del destructivo terremoto de magnitud 6.3 (12:51 p.m., 22 de febrero de 2011).
- Published
- 2015
16. Be isotope analysis of a 0–500ka loess–paleosol sequence from Rangitatau East, New Zealand
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Ian J. Graham, Robert G. Ditchburn, and Neil Whitehead
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Sedimentary depositional environment ,Provenance ,Loess ,Geochemistry ,Glacial period ,Southern Hemisphere ,Geomorphology ,Paleosol ,Geology ,Earth-Surface Processes ,Diagenesis ,Isotope analysis - Abstract
Be isotope profiles in a 17.4 m, 0–500 ka, loess–paleosol sequence at Rangitatau East (Wanganui, New Zealand) provide the first Southern Hemisphere comparison for data from the Chinese Loess Plateau and, in addition, offer new insights into the provenance and diagenetic history of the loess. The average 10 Be concentration in the sequence, 1.6×10 9 atoms g −1 , is about twice that of Chinese loess, probably due to higher rainfall (and hence higher 10 Be depositional flux) in the detrital source area. Both 10 Be and 9 Be appear to be relatively immobile on a 500 kyr time scale. Most of the 10 Be is associated with material transported to the depositional site, with only a small proportion added later via wet precipitation. 10 Be concentrations in the loess are similar to those in dunesands at the base of the sequence, indicating a local provenance of recycled marine sediments and soils transported by rivers onto the exposed seabed during glacial periods. A negative correlation between 10 Be/ 9 Be and δ 18 O suggests that these periods were relatively arid compared with the present, if somewhat wetter than the source area for Chinese loess.
- Published
- 2001
17. Application of a new method of searching for geochemical changes related to seismic activity
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G.L. Lyon and Neil Whitehead
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Disasters ,Delta ,Radiation ,Radon ,Fresh Water ,Soil science ,Induced seismicity ,Sensitivity and Specificity ,Geology ,Groundwater ,Environmental Monitoring ,New Zealand - Abstract
222Rn in groundwater at three out of four New Zealand sites changed in a statistically significant way in response to increased monthly coseismic events M2.0-M5, 14-100 km away, particularly events normal to a nearby large faultline. delta 18O(H2O) at one site showed a coseismic negative relationship to seismicity the same day. Of other parameters at the four sites (CO2, CH4/N2, H2/N2, delta 18O(H2O), delta 13C(CO2), delta 13C(CH4), D/H, Ar/N2), only the latter showed some consistent sensitivity to seismicity, mainly as after-effects. There was no observable threshold strain value. The 9000 events studied gave considerable statistical power, but correlations useful for seismicity prediction were few and doubtful. The frequent negative relationships may indicate the closing of rock cracks by strain, hence reduced gas flow.
- Published
- 1999
18. and contamination at zero age: a possible limitation on U/Th series dating of speleothem material
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Robert G. Ditchburn, P.W Williams, W.J. McCabe, and Neil Whitehead
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Series (stratigraphy) ,geography ,Stalactite ,geography.geographical_feature_category ,Alpha spectrometry ,Aragonite ,Geochemistry ,Mineralogy ,Speleothem ,Geology ,engineering.material ,Contamination ,Geochemistry and Petrology ,Absolute dating ,engineering - Abstract
Analysis of 67 New Zealand speleothem specimens for both 230 Th / 234 U and 231 Pa / 235 U by alpha spectrometry showed that in most cases the age concordance between them was excellent. However, analysis of two growing speleothems less than 100 years old showed apparent near-concordant ages of 2 and 3 ka—both 230 Th and 231 Pa had been added to the speleothem, contrary to a basic assumption of the dating method. In other cases of discordance there was additional evidence that 230 Th and sometimes 231 Pa had been added to the growing speleothem and probably originated from erosion of old limestone by carbonate-rich waters. Calculation shows that typical 230 Th and 232 Th contents in carbonate-rich waters could easily be deposited in sufficient quantity in growing speleothems in realistic time intervals to produce the amounts found in the straw stalactites. The U contents of these speleothem samples were unusually low (42% contained less than 0.1 mg kg −1 ) but aragonitic samples contained 100× as much U.
- Published
- 1999
19. 10Be spikes in Plio–Pleistocene cyclothems, Wanganui Basin, New Zealand: identification of the local flooding surface (LFS)
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Neil Whitehead, Ian J. Graham, and Robert G. Ditchburn
- Subjects
geography ,geography.geographical_feature_category ,Stratigraphy ,Geochemistry ,Geology ,Seafloor spreading ,Isotopes of oxygen ,Cyclothems ,chemistry.chemical_compound ,chemistry ,Continental margin ,Carbonate ,Sequence stratigraphy ,Ice sheet ,Geomorphology ,Marine transgression - Abstract
Marine shelf sediments of the Wanganui Basin (Castlecliff section) spanning oxygen isotope stages 21–17 (ca. 920–680 ka) contain spikes of enriched 10Be concentrations (and enhanced 10Be/9Be ratios), up to 10× `background' values. The 10Be spikes do not coincide precisely with peaks in carbonate content and grainsize, or with changes in bulk rock chemical composition. Rather, they appear in the sequence a little above the base of each cyclothem, at the presumed location of the local flooding surface (LFS). They therefore originated in response to seafloor sediment starvation during transgression, and not from ice sheet melting, biogenic scavenging or geomagnetic intensity changes, as has been suggested previously for 10Be spikes in some deep-sea or continental margin sequences.
- Published
- 1998
20. 210Pb chronology from Wellington Harbour, New Zealand
- Author
-
Neil Whitehead, James Goff, and Robert G. Ditchburn
- Subjects
Ecology ,fungi ,Sediment ,Aquatic Science ,body regions ,Oceanography ,Age estimation ,Harbour ,skin and connective tissue diseases ,computer ,Ecology, Evolution, Behavior and Systematics ,Geology ,Water Science and Technology ,Chronology ,computer.programming_language - Abstract
A sediment accumulation record based on the levels of “unsupported” 210Pb was obtained from a core taken from the centre of Wellington Harbour, New Zealand. Sediment accumulation rates (SARs) varied from 3 to 5 mm yr‐1. Before 1920, SARs were sufficiently high to dilute unsupported levels of 210Pb to background, but had fallen below the mean by 1925 maintaining constant SARs until 1953. These data provide a higher resolution chronology of early 20th century SARs than was previously available. Comparison with 137Cs data confirms that there was a significant increase in SARs between 1953 and 1967, but that these have remained fairly constant since 1974. Data from the two radionuclides are consistent after 1974, and 210Pb data are consistent with other chronological measurements before 1953. Therefore, it is suggested that the two radionuclides are immobile in the marine sediments of Wellington Harbour and that differences between the two SARs are real.
- Published
- 1998
21. Lichens as biomonitors of geothermal radionuclide pollution
- Author
-
Alberto Malfatti, Neil Whitehead, Mauro Sani, and Stefano Loppi
- Subjects
Pollution ,Geothermal power ,Parmelia ,media_common.quotation_subject ,chemistry.chemical_element ,Radon ,Travale ,lichens ,radionuclides ,radon ,environment ,Italy ,Lichen ,Geothermal gradient ,media_common ,Radionuclide ,biology ,Renewable Energy, Sustainability and the Environment ,Environmental engineering ,Geology ,Geotechnical Engineering and Engineering Geology ,biology.organism_classification ,chemistry ,Environmental chemistry ,Environmental science ,Epiphyte - Abstract
The epiphytic lichen Parmelia caperata was used systematically as a bioaccumulator of radionuclides in the Travale-Radicondoli geothermal field (central Italy). The results showed that radioactivity in this area is not different from that of other non-geothermal areas and that the exploitation of geothermal resources should not cause an enrichment in radioactivity. However, the survey also revealed a negative association between total β radioactivity in lichens and the distance from geothermal power plants, so that the latter may represent a source of local radionuclide pollution.
- Published
- 1997
22. 10Be investigations of sediments, soils and loess at GNS
- Author
-
Robert G. Ditchburn, Ian J. Graham, R.J. Sparks, and Neil Whitehead
- Subjects
Nuclear and High Energy Physics ,geography ,geography.geographical_feature_category ,Earth's magnetic field ,Loess ,Soil water ,Period (geology) ,Geochemistry ,Massif ,Instrumentation ,Geology - Abstract
Concentrations of 10Be have been measured in sediments and loess from the Wanganui region, New Zealand, and in soils from the Roberts Massif, Antarctica. The Wanganui sediments show a clear enhancement of 10Be over the period of the Brunhes-Matuyama geomagnetic field reversal, although the cause of the enhanced signal is not attributed directly to the field reversal event. Data from the Antarctic soils are consistent with an age of the landscape of the order of 12 million years.
- Published
- 1997
23. Unusual Childhood Waking as a Possible Precursor of the 1995 Kobe Earthquake
- Author
-
Motoji Ikeya and Neil Whitehead
- Subjects
lcsh:Veterinary medicine ,General Veterinary ,business.industry ,Earthquake prediction ,Kobe ,Rn-222 ,Article ,children ,Epicenter ,lcsh:Zoology ,Medicine ,lcsh:SF600-1100 ,Animal Science and Zoology ,lcsh:QL1-991 ,Hanshin ,precursors ,sleep ,business ,earthquakes ,Seismology - Abstract
Nearly 1,100 young students living in Japan at a range of distances up to 500 km from the 1995 Kobe M7 earthquake were interviewed. A statistically significant abnormal rate of early wakening before the earthquake was found, having exponential decrease with distance and a half value approaching 100 km, but decreasing much slower than from a point source such as an epicentre, instead originating from an extended area of more than 100 km in diameter. Because an improbably high amount of variance is explained, this effect is unlikely to be simply psychological and must reflect another mechanism—perhaps Ultra-Low Frequency (ULF) electromagnetic waves creating anxiety—but probably not 222Rn excess. Other work reviewed suggests these conclusions may be valid for animals in general, not just children, but would be very difficult to apply for practical earthquake prediction.
- Published
- 2013
- Full Text
- View/download PDF
24. A new method for determination of222Rn and220Rn in geothermal steam
- Author
-
Neil Whitehead and Robert G. Ditchburn
- Subjects
Materials science ,Isotope ,Health, Toxicology and Mutagenesis ,Thin layer ,Public Health, Environmental and Occupational Health ,Analytical chemistry ,Mineralogy ,Pollution ,Fumarole ,Analytical Chemistry ,Nuclear Energy and Engineering ,TRACER ,Yield (chemistry) ,Radiology, Nuclear Medicine and imaging ,Geothermal gradient ,Layer (electronics) ,Spectroscopy - Abstract
The radionuclides222Rn and220Rn are measured by incorporating their daughters214Pb and212Pb in a very thin layer of PbS and accumulating the alpha spectrum of their daughter products214Po and212Po. The median yield was measured as 88% using a known amount of210Pb tracer. A single fumarole and all 23 geothermal wells tested were found to contain220Rn. As isotopes of Th, Bi, Po and Ra, are also absorbed in the PbS layer, the method can be used for determinations of these in tap-water.
- Published
- 1996
25. Two new methods of determining radon diffusion in fish otoliths
- Author
-
Neil Whitehead and Robert G. Ditchburn
- Subjects
Radionuclide ,biology ,Orange roughy ,Chemistry ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Mineralogy ,chemistry.chemical_element ,Radon ,biology.organism_classification ,Pollution ,Analytical Chemistry ,Radon diffusion ,Nuclear Energy and Engineering ,%22">Fish ,Radiology, Nuclear Medicine and imaging ,Diffusion (business) ,Spectroscopy - Abstract
Otoliths are bony structures found in the ears of fish and used in the210Pb/226Ra dating method for age determination. This paper checks the assumption that222Rn is not lost from or added to orange roughy fish otoliths by diffusion, which would invalidate the technique. The first method of monitoring diffusion relies on measuring the gamma activity of daughter radionuclides. Otoliths were exposed to an atmosphere enriched in222Rn for 10 days, and the supported gamma activity inside them measured allowing for various decay corrections. The calculated radon addition was (0.5±0.5)% of the activity of the226Ra present. The second method used an alpha spectrometer and attempted to detect222Rn directly outgased from otoliths in the detector vacuum chamber. The results were consistent within errors with those of the first method and showed no loss or gain of222Rn, supporting previous estimates of a long life-span for the orange roughy. In contrast it was found that approximately 10% of222Rn formed in orange roughy fish scales was lost to an evacuated environment, (hence perhaps to an aqueous environment) and that for this species it could be difficult to base a dating method on analysis of scales. Nevertheless a preliminary minimum age of 57 years was obtained. The methods could be used with non-biological samples to determine222Rn diffusion rates.
- Published
- 1995
26. A study of corrosion products using a cocktail of radionuclides
- Author
-
Neil Whitehead
- Subjects
Radionuclide ,Goethite ,Aqueous solution ,Materials science ,Health, Toxicology and Mutagenesis ,Radiochemistry ,Metallurgy ,Spinel ,Public Health, Environmental and Occupational Health ,engineering.material ,Pollution ,Analytical Chemistry ,Corrosion ,Metal ,chemistry.chemical_compound ,Investigation methods ,Nuclear Energy and Engineering ,chemistry ,visual_art ,visual_art.visual_art_medium ,engineering ,Radiology, Nuclear Medicine and imaging ,Spectroscopy ,Magnetite - Abstract
A method of detecting inaccessible metallic corrosion is proposed, in which a gamma-emitting radionuclide added in aqueous solution to the contents of a pipe or vessel attaches itself selectively to corrosion products, and then may be detected from outside using a hand-held gamma detector. This was simulated in the laboratory in preliminary studies. Corrosion products studied were oxidised iron, FeS, goethite, magnetite, spinel and oxidised stainless steel.K d values were derived for various radionuclides. Of the radionuclides studied,60Co,152Eu,214Pb,214Bi and226Ra seem potentially useful, but not22Na or137Cs.
- Published
- 1994
27. A comparative study of Quaternary dating techniques applied to sedimentary deposits in southwest Victoria, Australia
- Author
-
Neil Whitehead, Robert G. Ditchburn, Martin J. Barbetti, R. W. L. Kimber, Colin V. Murray-Wallace, John Sherwood, John R. Prescott, and W. McCabe
- Subjects
Archeology ,Global and Planetary Change ,chemistry.chemical_element ,Geology ,Uranium ,law.invention ,Paleontology ,chemistry ,law ,Absolute dating ,Interglacial ,Radiocarbon dating ,Quaternary ,Uranium-thorium dating ,Relative dating ,Ecology, Evolution, Behavior and Systematics ,Holocene - Abstract
At five sites in western Victoria a total of five Quaternary dating techniques have been applied to shell beds varying in age from Holocene to beyond the last interglacial. To examine the age concordancy of the methods, 89 analyses were conducted—16 by radiocarbon, 26 by uranium series disequilibrium, 26 by amino acid racemisation, 5 by thermoluminescence and 16 by electron spin resonance, the latter previously reported by Goede (1989). Uncertainties associated with diagenetic environments of samples precluded reliable numerical age assignments for beds older than Holocene. Instead, relative dating of shell beds was based on a reference site (Goose Lagoon) which was assigned to the last interglacial based on its morphostratigraphic setting and concordant results of three of the dating methods (amino acid racemisation, uranium series disequilibrium and electron spin resonance). Overall there was considerable agreement between methods although not all were applied to each site. Uranium series dating proved most problematical. Migration of radionuclides between groundwater and shells introduced large errors at one site and led to appreciable uncertainties at others.
- Published
- 1994
28. Radionuclides in macro algae at Monaco following the Chernobyl accident
- Author
-
J. J. Lopez, Neil Whitehead, G. Barci-Funel, S. Ballestra, G. Ardisson, A. Bulos, and Elis Holm
- Subjects
Radionuclide ,Codium tomentosum ,biology ,Health, Toxicology and Mutagenesis ,Sphaerococcus coronopifolius ,Public Health, Environmental and Occupational Health ,biology.organism_classification ,Pollution ,Analytical Chemistry ,Nuclear Energy and Engineering ,Algae ,Environmental chemistry ,Corallina ,Activity concentration ,Environmental science ,Radiology, Nuclear Medicine and imaging ,Seawater ,Water pollution ,Spectroscopy ,Nuclear chemistry - Abstract
Samples of macro algae,Codium tomentosum (green),Corallina mediterranea (red),Sphaerococcus coronopifolius (red) andDictyota dichtoma (brown), were collected off Monaco during 1984 and 1988 and analyzed for gamma-emitting radionuclides and transuranium elements. Due to the Chernobyl accident, increased radioactivity in the atmosphere at Monaco was recorded on 30 April 1986 with maximal activity concentrations on 2–3 May. The maximal activity concentrations in sea water occurred on 5–6 May and in the algae on 11 May. The decrease of activity concentrations can be described after May 11 as a single exponential relationship, where elimination rates for different radionuclides and different species specific to the environment can be calculated.
- Published
- 1994
29. The elemental content of Niue Island soils as an indicator of their origin
- Author
-
Neil Whitehead, P. Rankin, D. Leslie, and J. Hunt
- Subjects
Calcite ,Dolomite ,Trace element ,Mineralogy ,Geology ,Weathering ,engineering.material ,chemistry.chemical_compound ,Geophysics ,chemistry ,Soil water ,Earth and Planetary Sciences (miscellaneous) ,Laterite ,engineering ,Chemical composition ,Volcanic ash - Abstract
The major and trace element contents of 241 Niue Island lateritic soils were determined, mainly by X‐ray fluorescence, to deduce soil origins. The analyses showed very low SiO2 content, and a high content of Mg, P, V, Cr, Sr, Y, Hg, and α‐counts, compared with other laterites worldwide. The distribution patterns are consistent with derivation by weathering from calcite and dolomite rather than from deposited volcanic ash. Weathering is a particularly novel explanation for the origin of the relatively high content of P in these soils. The soils contain a negative Ce anomaly, consistent with an origin from seawater or coral, but not volcanic ash. If recent results showing in situ formation of magnetite in soils are applicable, the soil mineralogy is wholly consistent with an origin from calcite/dolomite. An origin from calcite is also consistent with the relative lack of volcanic ash on the seabed nearby, and very low deposition of aeolian dust. The radioactivity content is consistent neither with ...
- Published
- 1993
30. A new model for the origin of the anomalous radioactivity in Niue Island (South Pacific) soils — Reply
- Author
-
Neil Whitehead
- Subjects
Geochemistry and Petrology ,Geology - Published
- 1993
31. A new model for the origin of the anomalous radioactivity in Niue Island (South Pacific) soils—Comments
- Author
-
Robert G. Ditchburn, Neil Whitehead, P. Rankin, and W.J. McCabe
- Subjects
Calcite ,Radionuclide ,Goethite ,Geochemistry ,Geology ,Weathering ,chemistry.chemical_compound ,chemistry ,Geochemistry and Petrology ,visual_art ,Soil water ,visual_art.visual_art_medium ,Seawater ,Gibbsite ,Volcanic ash - Abstract
The anomalous natural radioactivity of Niue Island is due to large excesses of both 230 Th and 231 Pa compared with their parent radionuclides. It is suggested that material in Niue Island soils, consisting mainly of goethite and gibbsite partially trapped within porous calcite, was exposed to seawater a few hundred thousand years B.P. and the U content of the seawater adsorbed onto the soil minerals. The island then rose and remained essentially above sea-level until present. The daughter products of the U isotopes grew into radioactive equilibrium with the U parents, but then the U parents were leached away some time in the span 100-70 ka B.P., leaving large amounts of orphan daughters in the soils without supporting parents.
- Published
- 1993
32. Detection of geological faults using a nuclear method
- Author
-
Neil Whitehead
- Subjects
Scintillation ,Health, Toxicology and Mutagenesis ,Nouvelle zelande ,Public Health, Environmental and Occupational Health ,Mineralogy ,Pollution ,Analytical Chemistry ,Permeability (earth sciences) ,Nuclear Energy and Engineering ,Fault gouge ,Soil water ,Radiology, Nuclear Medicine and imaging ,Spectroscopy ,Geology - Abstract
It proved possible to detect the precise location of large geological faults using the amount of40K and220Rn daughter gamma-rays and the amount of222Rn (measured in a scintillation chamber) which could be extracted from the soil using negative pressure. Both40K and228Th appear to be concentrated in fault gouge. The222Rn content extractable from the soil is a measure of permeability and is very low in the region of the fault due to clay-like fault gouge. The method was demonstrated successfully on the large Wellington fault at Upper Hutt, New Zealand.
- Published
- 1992
33. Factors affecting the electrodeposition of226Ra
- Author
-
Neil Whitehead, R. Van der Raaij, W.J. McCabe, and Robert G. Ditchburn
- Subjects
Reproducibility ,Chromatography ,Materials science ,Yield (engineering) ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,chemistry.chemical_element ,Pollution ,Cathode ,Analytical Chemistry ,law.invention ,Anode ,Nuclear Energy and Engineering ,chemistry ,Impurity ,law ,Plating ,Radiology, Nuclear Medicine and imaging ,Platinum ,Spectroscopy ,Deposition (law) ,Nuclear chemistry - Abstract
The electrodeposition of226Ra for α-spectrometry was reinvestigated to improve reproducibility and yield. Electrodeposition is from 20 ml of 90% propan-2-ol10% 0.05M HNO3 onto stainless steel disks, using 100 mA at 35 V for 20 minutes and a platinum anode. Half deposition time is 3–4 minutes. The following factors were found important: 1. Maintaining the same anode position. 2. Rotation of cathode. 3. Exclusion of sulphate. 4. Avoiding heating the HNO3/propan-2-ol plating solution. 5. Exclusion of solubilised resin resulting from passage through ion-exchange columns. 6. Maintaining other impurities at less than 10 μg. If these precautions are followed yields are greater than 90%.
- Published
- 1992
34. A method for separation of Po, Th, Pa and U in high yields from various matrices
- Author
-
W.J. McCabe, Neil Whitehead, and Robert G. Ditchburn
- Subjects
Ion exchange ,Elution ,Health, Toxicology and Mutagenesis ,Dolomite ,Ion chromatography ,Public Health, Environmental and Occupational Health ,Protactinium ,Thorium ,chemistry.chemical_element ,Pollution ,Analytical Chemistry ,chemistry.chemical_compound ,Nuclear Energy and Engineering ,chemistry ,Phosphorite ,Radiology, Nuclear Medicine and imaging ,Sulfate ,Spectroscopy ,Nuclear chemistry - Abstract
We give a new general method of separation of the title radionuclides, using ferric hydroxide precipitations, cation exchange chromatography followed by anion exchange for U, further cation exchange for Pa and direct elution for Th. Electrodeposition for all three elements is from sulfate medium. Yields for Pa, Th, Pa, U are mostly about 98%. Matrices analyzed include calcite, dolomite, phosphorite, sediments, organic material, and mineral fractions from rock.
- Published
- 1992
35. Sacral Violence: Cosmologies and Imaginaries of Killing
- Author
-
Neil Whitehead
- Published
- 2009
36. Tellurium—speciation in seawater and accumulation by marine phytoplankton and crustaceans
- Author
-
Jean-Louis Teyssié, Neil Whitehead, and C. Nolan
- Subjects
biology ,Health, Toxicology and Mutagenesis ,Thalassiosira pseudonana ,Branchiopoda ,Brine shrimp ,General Medicine ,Dunaliella ,biology.organism_classification ,Pollution ,Shrimp ,Environmental chemistry ,Phytoplankton ,Botany ,Environmental Chemistry ,Seawater ,Artemia salina ,Waste Management and Disposal - Abstract
Experiments were performed to determine the speciation of tellurium (using 129m Te as a radiotracer) in seawater and the extent of its accumulation by cultures of marine phytoplankton and crustaceans. Tellurite Te(IV) added to distilled water and to sterile filtered seawater was gradually transformed to the tellurate Te(VI) form, whereas Te(IV) tracer added to phytoplankton cultures was almost instantaneously transformed to a neutral form. Accumulation of radiotracer by phytoplankton ( Dunaliella tertiolecta and Thalassiosira pseudonana ) was moderate and for Dunaliella was greater in static cultures than in those which were actively dividing. Equilibrium concentration factors of 20 and 8 were established respectively after up to seven days' exposure of the herbivorous brine shrimp ( Artemia salina ) to labelled seawater with and without added phytoplankton. The loss of radionuclide upon transfer to uncontaminated running seawater was extensive and complete after one day, indicating that no true assimilation occurred. Transfer of radioactivity from Artemia salina to a predator, the Monaco shrimp ( Lysmata seticaudata ), was not observed.
- Published
- 1991
37. First results on 236U levels in global fallout
- Author
-
Neil Whitehead, Junpei Tomita, Francesca Quinto, Masayoshi Yamamoto, Kenta Kawai, Masaharu Hoshi, Peter Steier, Aya Sakaguchi, and K. Mino
- Subjects
Environmental Engineering ,Isotope ,Environmental engineering ,Air pollution ,chemistry.chemical_element ,Uranium ,medicine.disease_cause ,Atmospheric sciences ,Pollution ,Soil contamination ,Mass Spectrometry ,Plutonium ,Uranium-236 ,chemistry ,Japan ,Soil water ,medicine ,Environmental Chemistry ,Environmental science ,Soil Pollutants, Radioactive ,Waste Management and Disposal ,Accelerator mass spectrometry - Abstract
The global fallout 236 U level in soil was deduced from measurements of 236 U, 239+240 Pu and 137 Cs in surface soils which are solely influenced by global fallout. A total of 12 soil cores from the depths of 0–10, 0–20 and 0–30 cm were collected at a flat forest area in Japan. Concentrations of 239+240 Pu and 238 U were determined by α-particle spectrometry, while the 236 U/ 238 U ratio was measured with accelerator mass spectrometry (AMS). Consistent 236 U/ 239 Pu ratios between 0.212 and 0.253 were found. Using this ratio, the total global fallout of 236 U on the earth is estimated to be as much as ca. 900 kg. This knowledge will contribute to the promotion of research on U isotopes, including 236 U, for the fields of geo-resources, waste management and geochemistry.
- Published
- 2008
38. Anomalous Hg contents in soils of Niue Island, South Pacific
- Author
-
Peter Rankin, John Barrie, and Neil Whitehead
- Subjects
geography ,geography.geographical_feature_category ,Goethite ,Coral ,Geochemistry ,Atoll ,Geophysics ,Oceanography ,Volcano ,Geochemistry and Petrology ,visual_art ,Soil water ,visual_art.visual_art_medium ,Gibbsite ,Geology - Abstract
Niue Island, a raised coralline atoll in the South Pacific, has soils that have long been known to have strongly anomalous radioactivity. We now show that there is also a highly anomalous Hg content in the soils. It is associated with the radioactivity and the goethite/gibbsite content and the values are as high as those in soils over known Hg-mineralisation in volcanic settings, though no mineralisation is known on Niue and such an occurrence on this coral island would be geochemically unusual.
- Published
- 1990
39. Systematics of radon at the Wairakei geothermal region, New Zealand
- Author
-
C.J. Morris, M.K. Stewart, Robert G. Ditchburn, Neil Whitehead, and B. Barry
- Subjects
Polonium ,Lithology ,Health, Toxicology and Mutagenesis ,Geochemistry ,chemistry.chemical_element ,Mineralogy ,Radon ,General Medicine ,Uranium ,Pollution ,Fumarole ,Hot Springs ,Permeability (earth sciences) ,Deposition (aerosol physics) ,chemistry ,Radiation Monitoring ,Environmental Chemistry ,Waste Management and Disposal ,Geothermal gradient ,Groundwater ,Geology ,Environmental Monitoring ,New Zealand - Abstract
222 Rn and 220 Rn in geothermal steam at Wairakei, NZ, range from 11 to 19 500 Bq kg −1 , and 25 to 16 700 Bq kg −1 , respectively, but do not cause toxic concentrations in air. The wide ranges are mainly due to differences in different physical conditions underground (e.g. thin silica diffusion barriers), not geochemical differences. Groundwater Rn from outside the area probably plays only a minor role. 210 Po was found present in non-toxic levels in the steam. Historical records showed little change in Rn concentration over several decades, therefore potentially hazardous concentrations might be predicted from early exploration. 220 Rn concentrations at Wairakei should decrease as the field becomes steam-dominated. Rock surfaces were variably leached or enriched with U, Th, Ra and 210 Pb, providing a possible model for deposition in cooler regions near the field. Estimates of 222 Rn permeability ranged from 2 to 77% of the maximum possible, with a median of 13%.
- Published
- 2006
40. Preliminary results of using ESR to examine biofilms
- Author
-
Neil Whitehead, Atushi, T., Tazaki, K., and Ikeya, M.
- Subjects
Applied Microbiology and Biotechnology ,Biotechnology - Abstract
This preliminary work shows ESR (Electron Spin Resonance) can be used to detect biofilms, particularly from Fe-metabolising bacteria. A film was detected by ESR as early as 1 day, hence possibly more sensitively than by fluorescent methods. Films can probably be detected as early as one hour. Spectra contain a very broad peak at g=2.13, probably due to ferrihydrite. Results of field experiments from streams and ponds in New Zealand and Japan, particularly the Minoh River, showed a general increase of ferrihydrite with time. Loss by exfoliation was later than 20 days. The rate of accumulation was faster in a nutrient-rich stagnant pond. Hematite (g=4.3) was often observed, magnetite (g=9) once, and usually small amounts of a common bacterial decay product. The latter was detected for at least 18 months film storage. ESR is a particularly good tool for observing the growth of oxic biofilms containing Fe-metabolising bacteria, and should be just as sensitive for observing Mn-metabolising bacteria in reducing conditions.
- Published
- 2004
41. Revision of some ages for the Rotoehu Ash
- Author
-
Neil Whitehead and Robert G. Ditchburn
- Subjects
Light nucleus ,Series (stratigraphy) ,Geophysics ,Age estimation ,Radiometric analysis ,Earth and Planetary Sciences (miscellaneous) ,Mineralogy ,Geology ,K–Ar dating ,Radiometric dating ,Physical geography - Abstract
Previously published U/Th disequilibrium data for the Rotoehu Ash suggest an age of 71 ± 6 ka, in accord with whole rock K/Ar ages (64 ± 4 ka). However, examination of the internal ratios of isotopes in the U/Th decay series shows that the age is probably erroneous. Examination of other age data derived using various techniques gives further revised dates: 42.9 ±7.8 (ESR) and 35.1 ± 2.8 (14C). The latter is now based on four, non‐infinite, tightly clustered dates, but probably needs an upward calibration correction. More work is needed to resolve the continuing discrepancies. We also present eight new 230Th/232Th analyses for rhyolites and ignimbrites—the mean and standard deviation are 0.705 ± 0.076.
- Published
- 1994
42. The Crises And Transformations of Invaded Societies: The Caribbean (1492–1580)
- Author
-
Neil Whitehead
- Subjects
Caribbean island ,Negotiation ,education.field_of_study ,Vision ,History ,media_common.quotation_subject ,Population ,Ethnology ,Context (language use) ,education ,Indigenous ,media_common - Abstract
The native populations of the region that the Europeans came to call Caribbean were the first to negotiate the new realities to which this encounter gave rise, as well as to endure the ecological and demographic consequences of that arrival. The Caribbean was thus center stage in the crises and transformations of the indigenous societies of the Americas during the fateful years 1492-1580. By 1500 most of the complex native polities of Espanola had ceased to operate autonomously. The native networks of gold trading that the doradistas so eagerly hoped to intersect ultimately connected both the Caribbean islands and the western coasts of Tierra Firme to the heartland of the Colombian sierras. Dramatic population losses, through either war or disease, provided the demographic context for the emergence of new leaders and new visions of how Amerindian people might respond to the crisis of European invasion.
- Published
- 1999
43. Abstract 2782: Bcl-2 selective antagonists show antitumor activity without dose limiting platelet toxicity
- Author
-
Claire L. Nunns, Francisco Cruzalegui, Starck Jérôme-Benoît, John A. Hickman, Michael Wood, Patrick Casara, Stéphane Depil, James Edward Paul Davidson, Natalia Matassova, Christopher John Graham, Alain Bruno, Pawel Dokurno, Thierry Le Diguarher, Alain Pierre, James Murray, Neil Whitehead, Guillaume De Nanteuil, Olivier Geneste, and Chen I-Jen
- Subjects
Cancer Research ,Programmed cell death ,Pharmacology ,Biology ,Oncology ,Mechanism of action ,Apoptosis ,In vivo ,Cell culture ,Toxicity ,medicine ,Platelet ,medicine.symptom ,IC50 - Abstract
Proteins of the Bcl-2 family are central regulators of programmed cell death. Pro-survival Bcl-2 proteins, such as Bcl-2, Bcl-xL and Mcl-1 are often over-expressed in human tumours and participate in tumour initiation, progression and chemo-resistance. Therefore drugs targeting these pro-survival Bcl-2 proteins represent a promising therapeutic approach for cancer treatment. The most advanced drug targeting this protein family is ABT-263, a potent Bcl-2 and Bcl-xL inhibitor showing anti-tumour efficacy in preclinical models of leukaemia and small cell lung carcinoma. Survival of circulating platelets has been shown to be highly Bcl-xL dependent; consequently the dose-limiting toxicity of ABT-263 is an on-target peripheral thrombocytopenia. We have used a range of biophysical methods to guide the structure-based generation of a significant number of small molecules,* which bind with high affinity (MW < 780; KD < 1 nM) to the BH3 binding groove of Bcl-2, and with high selectivity versus other members of the Bcl-2 family (selectivity > 100 fold). In cellular assays, our lead compounds efficiently displace Bax from Bcl-2 with near complete inhibition of Bcl-2 / Bax co-immunoprecipitation at 100 nM. These compounds are strong inducers of cell death in Bcl-2 dependent cellular models such as the acute myeloblastic leukaemia (AML) cell line RS4;11, affording sub-10 nM IC50's for the most potent compounds. In vivo, in agreement with their mechanism of action, these Bcl-2 selective inhibitors, given either intravenously or orally, elicit a rapid (30 min iv, and 2 hours po) and strong apoptotic response in mouse xenografts of the RS4:11 cell line. When the most potent compounds are given orally to RS4;11 xenograft-bearing mice, apoptosis in tumor cells is induced more than 15 fold (at 25 mg/kg) and more than 20 fold (at 50 mg/kg) compared to untreated mice. Importantly, in agreement with the selectivity of the compounds for Bcl-2 versus Bcl-xL, no platelet loss was observed in mice treated with our compounds, in sharp contrast to ABT-263. Finally, we observe very robust anti-tumor activity when a lead compound is given orally at 50 mg/kg and 100 mg/kg (with complete regression at 100 mg/kg) in an RS4;11 mouse xenograft model. This anti-tumor activity was similar whether the compound was dosed daily or twice a week over two weeks. Altogether our data demonstrate that highly Bcl-2 selective antagonists show anti-tumor activity and no platelet toxicity, in contrast to Bcl-2 / Bcl-xL dual inhibitors. Such compounds represent promising drug candidates for the treatment of Bcl-2 dependent malignancies such as chronic lymphocytic leukaemia (CLL) and other leukaemias and lymphomas. * Chemical structures of compounds will not be disclosed. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2782. doi:1538-7445.AM2012-2782
- Published
- 2012
44. Response to Zenner
- Author
-
Neil Whitehead
- Subjects
General Medicine - Published
- 2009
45. Absent-Minded Imperialism: Britain and the Expansion of Empire in Nineteenth-Century Brazil
- Author
-
Neil Whitehead and Peter Riviere
- Subjects
Arts and Humanities (miscellaneous) ,Anthropology - Published
- 1996
46. Iodine-129 measurements in soil samples from Dolon village near the Semipalatinsk nuclear test site.
- Author
-
Satoru Endo, Junpei Tomita, Kenichi Tanaka, Masayoshi Yamamoto, Satoshi Fukutani, Tetsuji Imanaka, Aya Sakaguchi, Hikaru Amano, Hidehisa Kawamura, Hisao Kawamura, Kazbek Apsalikov, Boris Gusev, Neil Whitehead, Sergey Shinkarev, and Masaharu Hoshi
- Abstract
Abtract Dolon village, located about 60 km from the border of the Semipalatinsk nuclear test site, is known to be heavily contaminated by the first USSR atomic bomb test in August 1949. Soil samples around Dolon were taken in October 2005 in an attempt to evaluate internal thyroid dose arising from incorporation of radioiodine isotopes (mainly 131I). Iodine-129 in soil was measured by using the technique of accelerator mass spectrometry. The 129I/127I atom ratios measured were in the range from 3.3 × 10−9 to 3.3 × 10−7. These values were within the range of the current background level (∼10−9 to 10−7) in the environment, including contributions from the global fallout of atmospheric nuclear tests and local fallout of nuclear facilities. The 129I atom accumulated level in soil ranged from 1.28 × 1013 to 1.59 × 1014 atoms m−2, the average (8.0 × 1013) of which was higher than the background level of (2–5) × 1013. From the relationship between 129I and 137Cs (corrected for background and decay from 1949 to 2005) accumulated levels, the background level of 129I and the 129I/137Cs ratio around Dolon were estimated to be (6.4 ± 0.4) × 1013 atoms m−2 and 0.25 ± 0.16, respectively. This 129I/137Cs ratio is almost similar to the fission yield ratio for 239Pu fast fission (0.24). [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
47. Methods of hair analysis by (p, X) spectrometry
- Author
-
Neil Whitehead
- Subjects
chemistry.chemical_compound ,Materials science ,Filter paper ,chemistry ,Nitric acid ,Hair analysis ,Plastic film ,Analytical chemistry ,General Medicine ,Mass spectrometry ,Dissolution ,Beam (structure) ,Intensity (heat transfer) - Abstract
The use of (p, X) spectrometry for hair analysis presents difficulties if absolute elemental concentrations are required. This arises because it is not clear what mass of hair the beam is hitting. Attempts to get around this by measuring the scattered protons, or the intensity of the sulphur X-ray peak, or by calculation, were not successful. Neither of the parameters was related to the mass analysed, because of probable irregular shape and elemental distribution. The problems can be overcome by dissolving a weighed amount of hair in hot nitric acid, adding an internal standard, and drying it on filter paper or a thin plastic film.
- Published
- 1979
48. Radon measurements at three New Zealand geothermal areas
- Author
-
Neil Whitehead
- Subjects
Hydrology ,chemistry.chemical_classification ,Carbon dioxide in Earth's atmosphere ,Renewable Energy, Sustainability and the Environment ,business.industry ,Geothermal energy ,Geochemistry ,chemistry.chemical_element ,Geology ,Radon ,Geotechnical Engineering and Engineering Geology ,chemistry.chemical_compound ,Permeability (earth sciences) ,chemistry ,Carbon dioxide ,Compounds of carbon ,business ,Geothermal gradient ,Groundwater - Abstract
Radon-222 measurements ranging from 0·10 to 62 nCi l−1CO2 are reported for geothermal areas at Wairakei, Broadlands and Ngawha, New Zealand. They suggest that for Wairakei the origin of the 222Rn is deep, follows the carbon dioxide, and there is little contribution from local ground water. The reverse is true at Ngawha, and Broadlands is intermediate. Comparison of radon and carbon dioxide levels gives some information about permeability in a given field. If a negative correlation is found, permeability may be predicted to be low.
- Published
- 1980
49. Determination of227Ac in environmental samples by ion-exchange and alpha spectrometry
- Author
-
R. Bojanowski, Neil Whitehead, and Elis Holm
- Subjects
Ion exchange ,Chemistry ,Health, Toxicology and Mutagenesis ,Radiochemistry ,Public Health, Environmental and Occupational Health ,Thorium ,chemistry.chemical_element ,Pollution ,Oxalate ,Analytical Chemistry ,Propanol ,chemistry.chemical_compound ,Actinium ,Nuclear Energy and Engineering ,Nitric acid ,Yield (chemistry) ,Radiology, Nuclear Medicine and imaging ,Spectroscopy ,Isotopes of thorium - Abstract
A new method of227Ac determination is based on total sample decomposition, followed by preconcentration as oxalate and hydroxides, and purification from thorium isotopes and rare earths on ion-exchange columns with nitric acid. The actinium is electroplated on stainless-steel discs with near 100% yield from a water/propanol medium and measured by alpha spectrometry.225Ac is used as a yield monitor. An immediate first count gives overall tracer recovery (typically around 80%). A second count two months later gives a sensitive measure of227Ac through its decay products at 5.5–6.1 MeV. Analysis of reference samples gave satisfactory results.
- Published
- 1987
50. A New Zealand test of the track-etch® method of prospecting for geothermal steam
- Author
-
J.C. Fisher, J.E. Gingrich, and Neil Whitehead
- Subjects
geography ,geography.geographical_feature_category ,Mineralogy ,chemistry.chemical_element ,Drilling ,Radon ,Fault (geology) ,respiratory tract diseases ,Geothermal exploration ,Geophysics ,Impact crater ,chemistry ,Geochemistry and Petrology ,Pumice ,Prospecting ,Geothermal gradient ,Geology - Abstract
The Track Etch® system for radon detection was evaluated as a geothermal exploration technique in a known geothermal resource area in New Zealand called the Craters of the Moon (previously known as “Karapiti”). Very strong radon anomalies spaced along mapped fault traces were detected using 60-m sample spacings. Such radon anomalies may indicate good areas to drill for steam. The anomalies detected in these tests were located inside a larger area known to have above-back-ground concentrations of radon and thought to be a generally favourable area for finding shallow steam. Track Etch® radon cups with an improved type of detector were found to be usable in ground temperatures as high as 60°C. There was no direct correlation of radon concentrations with resistivity measurements, but a moderate correlation with near-surface temperature measurements. Varying vegetation cover had no significant effect on the results but there was an apparent correlation with superficial pumice deposits. It is concluded from the tests that the Track Etch method shows promise in vapour-dominated areas for improving drill-hole siting and thus reducing the economic loss of drilling non-productive holes.
- Published
- 1983
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