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2006

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University of Massachusetts Amherst

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Will Radiation-Induced Bystander Effects Or Adaptive Responses Impact On The Shape Of The Dose Response Relationships At Low Doses Of Ionizing Radiation?, William F Morgan Dec 2006

Will Radiation-Induced Bystander Effects Or Adaptive Responses Impact On The Shape Of The Dose Response Relationships At Low Doses Of Ionizing Radiation?, William F Morgan

Dose-Response: An International Journal

Radiation induced bystander effects and adaptive responses are two phenomena that modulate cellular responses to low doses of ionizing radiation. Bystander effects generally exaggerate the effects of low doses of radiation by eliciting detrimental effects in nonirradiated cells, thus making the target for radiation effects greater than the volume irradiated. Adaptive responses on the other hand indicate that low doses of radiation can reduce damage induced by a second challenging dose. The potential impact of these two low dose effects on the shape of the dose response relationship will be discussed.


Adaptive And Bystander Responses In Human And Rodent Cell Cultures Exposed To Low Level Ionizing Radiation: The Impact Of Linear Energy Transfer, Sonia M De Toledo, Edouard I Azzam Dec 2006

Adaptive And Bystander Responses In Human And Rodent Cell Cultures Exposed To Low Level Ionizing Radiation: The Impact Of Linear Energy Transfer, Sonia M De Toledo, Edouard I Azzam

Dose-Response: An International Journal

To understand the potential impact on risk from exposure to low-level ionizing radiation, we have investigated the modulation of gene expression, induction of DNA damage and of neoplastic transformation in human or rodent cells derived from cultures exposed in vitro to low dose γ-rays (a low linear energy transfer radiation) or very low fluences of α-particles (a high linear energy transfer radiation). Pre-exposure of cells to a low γ-ray dose protected cells from the DNA damaging and killing effects induced by a subsequent acute challenge exposure to γ-rays. Furthermore, a low dose chronic exposure to γ-rays decreased the frequency of …


Development Of An In Vivo Assay For Detection Of Nontargeted Radiation Effects, Colin Seymour, Carmel Mothersill Dec 2006

Development Of An In Vivo Assay For Detection Of Nontargeted Radiation Effects, Colin Seymour, Carmel Mothersill

Dose-Response: An International Journal

An adaptive response may be defined as the effect of a small priming dose of radiation modifying the anticipated cellular response of the same tissues so as to alter the predicted response to a larger dose of radiation. We and others have demonstrated that at low radiation doses (less than 0.5 Gy) the lethal and mutational effect of the radiation is mainly, possibly entirely, due to the non-targeted effects. This is the dose range for priming doses in adaptive response protocols. In an associated presentation from our group, we demonstrate that the adaptive response may be explicable as a non …


Preface Dec 2006

Preface

Dose-Response: An International Journal

No abstract provided.


Radiation-Induced Bystander And Adaptive Responses In Cell And Tissue Models, Kevin M Prise, Melvyn Folkard, Barry D Michael Dec 2006

Radiation-Induced Bystander And Adaptive Responses In Cell And Tissue Models, Kevin M Prise, Melvyn Folkard, Barry D Michael

Dose-Response: An International Journal

The use of microbeam approaches has been a major advance in probing the relevance of bystander and adaptive responses in cell and tissue models. Our own studies at the Gray Cancer Institute have used both a charged particle microbeam, producing protons and helium ions and a soft X-ray microprobe, delivering focused carbon-K, aluminium-K and titanium-K soft X-rays. Using these techniques we have been able to build up a comprehensive picture of the underlying differences between bystander responses and direct effects in cell and tissue-like models. What is now clear is that bystander dose-response relationships, the underlying mechanisms of action and …


Radiation-Induced Bystander Effects: Evidence For An Adaptive Response To Low Dose Exposures?, Carmel Mothersill, Colin Seymour Dec 2006

Radiation-Induced Bystander Effects: Evidence For An Adaptive Response To Low Dose Exposures?, Carmel Mothersill, Colin Seymour

Dose-Response: An International Journal

This paper reviews our current knowledge of the mechanisms underlying the induction of bystander effects by low dose, low-LET ionizing radiation and discusses how they may be related to observed adaptive responses or other protective effects of low dose exposures. Bystander effects appear to be the result of a generalized stress response in tissues or cells. The signals may be produced by all exposed cells, but the response appears to require a quorum in order to be expressed. The major response involving low LET radiation exposure discussed in the existing literature is a death response. This has many characteristics of …


In Vivo Mutagenic Effect Of Very Low Dose Radiation, Pamela J Sykes, Tanya K Day, Sarah J Swinburne, Joanne M Lane, Alexander A Morley, Anthony M Hooker, Madhava Bhat Dec 2006

In Vivo Mutagenic Effect Of Very Low Dose Radiation, Pamela J Sykes, Tanya K Day, Sarah J Swinburne, Joanne M Lane, Alexander A Morley, Anthony M Hooker, Madhava Bhat

Dose-Response: An International Journal

Almost all of our knowledge about the mutational effect of radiation has come from high dose studies which are generally not relevant to public exposure. The pKZ1 mouse recombination mutagenesis assay enables study of the mutational effect of very low doses of low LET radiation (μGy to cGy range) in a whole animal model. The mutational endpoint studied is chromosomal inversion which is a common mutation in cancer. We have observed 1) a non-linear dose response of induced inversions in pKZ1 mice exposed to a wide dose range of low LET radiation, 2) the ability of low priming doses to …


Suppression Of Neoplastic Transformation In Vitro By Low Doses Of Low Let Radiation, J. Leslie Redpath Dec 2006

Suppression Of Neoplastic Transformation In Vitro By Low Doses Of Low Let Radiation, J. Leslie Redpath

Dose-Response: An International Journal

A major concern of exposure to low doses of radiation is the risk of cancer induction. Epidemiologic data are rarely powerful enough to accurately discriminate this risk at doses <10 cGy. In order to gain insight into events at these low doses, laboratory-based studies of relevant endpoints are required. One such endpoint is radiation-induced neoplastic transformation in vitro. Such studies can provide quantitative dose-response data, as well as insights into underlying cellular and molecular mechanisms. Data are presented that indicate that low doses of low LET radiation can suppress neoplastic transformation in vitro to levels below that seen spontaneously. Mechanisms involved include both the death of a subpopulation of cells prone to spontaneous neoplastic transformation and the induction of DNA repair. The relative contributions of these mechanisms is dose-dependent. The relevance of these observations to radiation risk estimation is discussed.


Enhancement Of Bio-Protective Functions By Low Dose/Doserate Radiation, Kazuo Sakai, Takaharu Nomura, Yasihiro Ina Dec 2006

Enhancement Of Bio-Protective Functions By Low Dose/Doserate Radiation, Kazuo Sakai, Takaharu Nomura, Yasihiro Ina

Dose-Response: An International Journal

Effects of low-dose-rate gamma-irradiation on the process of tumorigenesis were investigated in mice treated with a carcinogenic agent or irradiated with high dose X-rays at a high dose rate. A prolonged gamma irradiation at approximately 1 mGy/hr suppressed the appearance of skin tumors induced by methylcholanthrene and delayed the appearance of radiation-induced thymic lymphomas in C57BL/6 mice. We also investigated the effects of low-dose-rate irradiation on disease model mice. In Type II diabetic C57BL/KsJdb/ db (db) mice, the urine glucose level was improved in some of the mice irradiated at 0.70 mGy/hr, but not in non-irradiated control mice. In MRL-lpr/lpr …


The Adaptive Response And Protection Against Heritable Mutations And Fetal Malformation, Dr Boreham, J-A Dolling, C Somers, J Quinn, Rej Mitchel Dec 2006

The Adaptive Response And Protection Against Heritable Mutations And Fetal Malformation, Dr Boreham, J-A Dolling, C Somers, J Quinn, Rej Mitchel

Dose-Response: An International Journal

There are a number of studies that show radiation can cause heritable mutations in the offspring of irradiated organisms. These “germ-line mutations” have been shown to occur in unique sequences of DNA called “minisatellite loci”. The high frequencies of spontaneous and induced mutations at minisatellite loci allow mutation induction to be measured at low doses of exposure in a small population, making minisatellite mutation a powerful tool to investigate radiation-induced heritable mutations. However, the biological significance of these mutations is uncertain, and their relationship to health risk or population fitness is unknown. We have adopted this mutation assay to study …


Africa And The Transatlantic Slave Trade: Revisiting The Olaudah Equiano Legacy Dec 2006

Africa And The Transatlantic Slave Trade: Revisiting The Olaudah Equiano Legacy

African Diaspora Archaeology Newsletter

No abstract provided.


American Demands, African Treasures, Mixed Possibilities, Daniel Mcneil Dec 2006

American Demands, African Treasures, Mixed Possibilities, Daniel Mcneil

African Diaspora Archaeology Newsletter

In the 1990s, many Americans sought to cast themselves as heroic defenders of the liberal arts by condemning Afrocentricity. This paper reveals how many such profiteers and schemers were invested in Eurocentricity, but it also critiques Molefi Asante -- the man who coined the phrase "Afrocentricity" -- and points out his reliance on AfroAmericocentric norms. This paper was originally published in the Canadian Review of American Studies, 36(2): 181-93 (2006), and is republished here by the author, in slightly modified form, with the Review's generous permission.


Association For The Study Of The Worldwide African Diaspora Dec 2006

Association For The Study Of The Worldwide African Diaspora

African Diaspora Archaeology Newsletter

No abstract provided.


Caribbean Grave Site Illuminates Slavery, Mat Probasco Dec 2006

Caribbean Grave Site Illuminates Slavery, Mat Probasco

African Diaspora Archaeology Newsletter

No abstract provided.


Caribbean Studies Association 32nd Annual Conference Dec 2006

Caribbean Studies Association 32nd Annual Conference

African Diaspora Archaeology Newsletter

No abstract provided.


Carolina Low Country And Atlantic World Commemorating The Abolition Of The Atlantic Slave Trade Dec 2006

Carolina Low Country And Atlantic World Commemorating The Abolition Of The Atlantic Slave Trade

African Diaspora Archaeology Newsletter

No abstract provided.


Field School In Historical Archaeology Falmouth, Jamaica Dec 2006

Field School In Historical Archaeology Falmouth, Jamaica

African Diaspora Archaeology Newsletter

No abstract provided.


From Huts To Barracóns In Nineteenth-Century Cuba Plantations, Lisette Roura Alvarez Dec 2006

From Huts To Barracóns In Nineteenth-Century Cuba Plantations, Lisette Roura Alvarez

African Diaspora Archaeology Newsletter

No abstract provided.


International Day For The Abolition Of Slavery, U.N. Secretary-General Dec 2006

International Day For The Abolition Of Slavery, U.N. Secretary-General

African Diaspora Archaeology Newsletter

No abstract provided.


From Microscope To The Marriage Contract Of Castile's Trastamara Dynasts Isabel And Fernando: Evidence Of African Berber And Germanic Cultural Fusion, Marsha Robinson Dec 2006

From Microscope To The Marriage Contract Of Castile's Trastamara Dynasts Isabel And Fernando: Evidence Of African Berber And Germanic Cultural Fusion, Marsha Robinson

African Diaspora Archaeology Newsletter

This paper explores aspects of African diasporas beyond the context of the trans-Atlantic slave trade. The author examines genetic evidence that calls for a syncretic history of Spain. Exploring the fusion of cultural practices with respect to gender and power as found in the fifteenth-century marriage contract between Isabel of Castile and Fernando of Aragon, this paper further analyzes the historiography of the Christian expansion on the peninsula, the Berber legal system that arrived in Iberia with the Islamic conquest, and the Visigothic legal system that dominated in Aragon. The author further examines evidence of cultural fusion of African Berber …


Journal Of Pan African Studies. Special Issue On Black Spirituality Dec 2006

Journal Of Pan African Studies. Special Issue On Black Spirituality

African Diaspora Archaeology Newsletter

No abstract provided.


In Search Of Skeletons, Elizabeth Redden Dec 2006

In Search Of Skeletons, Elizabeth Redden

African Diaspora Archaeology Newsletter

No abstract provided.


Libraries In The Sand Reveal Africa's Academic Past, Nick Tattersall Dec 2006

Libraries In The Sand Reveal Africa's Academic Past, Nick Tattersall

African Diaspora Archaeology Newsletter

No abstract provided.


On The Transportation Of Material Goods By Enslaved Africans During The Middle Passage: Preliminary Findings From Documentary Sources, Jerome S. Handler Dec 2006

On The Transportation Of Material Goods By Enslaved Africans During The Middle Passage: Preliminary Findings From Documentary Sources, Jerome S. Handler

African Diaspora Archaeology Newsletter

No abstract provided.


Murder At Montpelier: Igbo Africans In Virginia, Douglas B. Chambers, Gloria Chuku Dec 2006

Murder At Montpelier: Igbo Africans In Virginia, Douglas B. Chambers, Gloria Chuku

African Diaspora Archaeology Newsletter

No abstract provided.


Museum Developments In 2006 Dec 2006

Museum Developments In 2006

African Diaspora Archaeology Newsletter

No abstract provided.


Slave Routes In Western Tanzania: A Preliminary Report On Survey In Tabora And Ujiji, Sarah Croucher, Stephanie Wynne-Jones Dec 2006

Slave Routes In Western Tanzania: A Preliminary Report On Survey In Tabora And Ujiji, Sarah Croucher, Stephanie Wynne-Jones

African Diaspora Archaeology Newsletter

The following report is a brief introduction to reconnaissance survey work carried out in Western Tanzania in July 2006 to investigate caravan routes that ran from the East African coast inland as far as the Congo during the 18th and 19th centuries. These routes were tied to the trading of captive Africans from inland areas to the Indian Ocean coast. When they reached the coast, enslaved individuals were either kept to work on local Arab-run plantations, or traded out into the Indian Ocean. Although it has proved difficult to quantify the number of slaves being traded from this region during …


Seventy Years Ago In Jamaica Dec 2006

Seventy Years Ago In Jamaica

African Diaspora Archaeology Newsletter

No abstract provided.


Society For Historical Archaeology 2007 Conference On Historical And Underwater Archaeology Dec 2006

Society For Historical Archaeology 2007 Conference On Historical And Underwater Archaeology

African Diaspora Archaeology Newsletter

No abstract provided.


Women And Religion In The African Diaspora: Knowledge, Power, And Performance, R. Marie Griffith, Barbara Dianne Savage Dec 2006

Women And Religion In The African Diaspora: Knowledge, Power, And Performance, R. Marie Griffith, Barbara Dianne Savage

African Diaspora Archaeology Newsletter

No abstract provided.