CTS focus about the information and communication technologies on the development of Angola

NASA Astrophysics Data System (ADS)

Patrocínio, Gilberto; Ferreira, Orlando Rodrigues; Schimiguel, Juliano; Silveira, Ismar; Voelzke, Marcos Rincon

2012-10-01

This paper aims at developing a systematic analysis on the Information and Communication Technologies (ICT) and Distance Learning in the development of Angola. Currently Angola as one of the most important African countries, the protagonist of the African Union (AU), is in extensive development and rebuilding themselves socially, economically and politically. In the process, Education becomes essential and, together with a proposal to insert through the Information and Communication Technologies (ICTs), proceeds to the achievement of a future process where science and technology apply in favor of a society, a real action CTS. In this effort we analyzed the most sensitive aspects of the Angolan reality, trying to identify the main points that require dependence on imports in the ICT sector, were also exposed fundamental strategies and initiatives for the implementation of an ICT industry in Angola. It also presented the main center of the Angolan Network for Distance Learning (NDL) and its major partners. And as a proposed application, was taken into consideration the statement of partnership between Southern Cross University and the University Agostinho Neto (UAN) for Distance Education.

Workers' Education--Seen by an African Trade Unionist.

ERIC Educational Resources Information Center

Labour Education, 1982

1982-01-01

The Secretary-General of the Organization of African Trade Union Unity gives a broad overview of workers' education activities conducted by that union, describes the activities, and discusses how the activities differ in concept and content from such activities in other parts of the world. (CT)

The African Organisation for Research and Training in Cancer and its conferences: a historical perspective and highlights of the Ninth International Conference, Durban, South Africa, 21-24 November 2013.

PubMed

Williams, Christopher Ko; Cristina Stefan, D; Rawlinson, Fiona; Simbiri, Kenneth; Mbulaiteye, Sam M

2014-01-01

The objectives of the African Organisation for Research and Training in Cancer (AORTIC), both at its inception in the early 1980s, and at its reactivation in 2000 following a decade of inactivity, included bringing the products of decades of advances in cancer research to African populations through international collaboration. The historical perspective provided in this report illustrates progress in achieving these objectives through successive continent-wide activities over a period of 30 years, culminating in the organisation's most recent conference held in Durban, South Africa, 21-24 November 2013. The constant growth in the number of attendants and increasing diversity of the nations of their origin are consistent with advances, whereby the number of participants and the nations of their origin have grown from 24 in 1983 to almost 1000 in 2013, and from 14 to 70, respectively. While earlier AORTIC conferences used to assume the atmosphere of 'jamborees', more recent ones have morphed to problem-solving events, with the concerted collaboration of international organisations, including the World Health Organisation (WHO), International Union Against Cancer (UICC), the Africa Union (AU), the US National Cancer Institute (NCI), the International Psycho-Oncology Society (IPOS), and others. The topics of discussion at the Ninth AORTIC International Conference on Cancer in Africa in Durban were those of paramount importance for low- and middle-income countries: childhood cancers, cancers of the cervix, breast, and prostate, as well as cancer care challenges resulting from ignorance, neglect, and economic deprivation. The role of environmental factors that underlie Burkitt's lymphoma was the subject of the Epidemiology of Burkitt Lymphoma in East-African Children and Minors Workshop, highlighting the NCI research programme in East Africa, while the Workshop on Cost Effectiveness of Treatment of Cancer in Africa surmised that treating childhood cancers is affordable in Africa in spite of widespread economic deprivation. WHO representatives emphasised the organisation's commitment to the global control of non-communicable diseases (NCDs), including cancer, and promoted the new initiatives for the control of cervical cancer, one of the commonest and deadliest cancers in adult Africans. AU representative proffered the principles of 'demographic dividends' for Africa to be able to tackle its burden of NCDs. UICC, represented by its President, provided guidelines for cancer diagnosis and staging, and advised on its effort to improve global access to radiotherapy, especially in Africa, while IPOS led the discussions on mitigating the suffering that is associated with the late presentation of cancer in the region. Oral and poster presentations from various parts of the continent indicate the growth of basic science of cancer in the region, with studies revealing regional diversity in the frequencies of the triple-negative breast cancer. They also suggest a need for genome-wide association studies as well as the evaluation of single nucleotide polymorphisms that may be responsible for variable susceptibility in breast and prostate cancer in people of African descent. Finally, the AORTIC leadership announced its plan for the advancement of cancer control by intensifying cancer advocacy at all levels of governance in the region.

Air medical evacuations from a developing world conflict zone.

PubMed

Low, Adam; Vadera, Bettina

2011-01-01

Somalia has been without effective government for close to two decades, with more than 1 million people internally displaced. The political unrest persists, with United Nations-backed African Union peacekeeping forces supporting the Transitional National government of Sharif Ahmed, struggling to maintain control of central Mogadishu from Islamist extremist groups, such as the reportedly Al-Qaeda-backed Al-Shabab. The African Union force of 5,000 troops is predominantly of Ugandan and Burundian origin, making up the African Mission in Somalia (AMISOM) effort. However, its mandate is limited to operations only in Mogadishu, and it is unauthorized to actively pursue insurgents. As with other ongoing high-profile conflicts, African Union troops face an enemy that blends into the civilian populace, fighting with a lethal mixture of improvised explosive devices and suicide bombers. Copyright © 2011 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

Advising Host Nations and Host Nation Security Forces: The United States Military Advisory Efforts through 2020

DTIC Science & Technology

2014-05-22

Contingency Operations Training and Assistance (ACOTA) with training support for the United Nations - African Union Mission in Darfur (UNAMID) in FY14.183...Initiative (GPOI) when GPOI activated in 2004.The United Nations established the African Union/UN Hybrid operation in Darfur on July 31, 2007 with the

Tenancy and African American Marriage in the Postbellum South

PubMed Central

Bloome, Deirdre; Muller, Christopher

2015-01-01

The pervasiveness of tenancy in the postbellum South had countervailing effects on marriage between African Americans. Tenancy placed severe constraints on African American women’s ability to find independent agricultural work. Freedwomen confronted not only planters’ reluctance to contract directly with women but also whites’ refusal to sell land to African Americans. Marriage consequently became one of African American women’s few viable routes into the agricultural labor market. We find that the more counties relied on tenant farming, the more common was marriage among their youngest and oldest African American residents. However, many freedwomen resented their subordinate status within tenant marriages. Thus, we find that tenancy contributed to union dissolution as well as union formation among freedpeople. Microdata tracing individuals’ marital transitions are consistent with these county-level results. PMID:26223562

Tenancy and African American Marriage in the Postbellum South.

PubMed

Bloome, Deirdre; Muller, Christopher

2015-10-01

The pervasiveness of tenancy in the postbellum South had countervailing effects on marriage between African Americans. Tenancy placed severe constraints on African American women's ability to find independent agricultural work. Freedwomen confronted not only planters' reluctance to contract directly with women but also whites' refusal to sell land to African Americans. Marriage consequently became one of African American women's few viable routes into the agricultural labor market. We find that the more counties relied on tenant farming, the more common was marriage among their youngest and oldest African American residents. However, many freedwomen resented their subordinate status within tenant marriages. Thus, we find that tenancy contributed to union dissolution as well as union formation among freedpeople. Microdata tracing individuals' marital transitions are consistent with these county-level results.

Teacher Unions' Participation in Policy Making: A South African Case Study

ERIC Educational Resources Information Center

Govender, Logan

2015-01-01

This article contends that teacher unions' participation in policy making during South Africa's political transition was characterised by assertion of ideological identity (unionism and professionalism) and the cultivation of policy networks and alliances. It is argued that, historically, while teacher unions were divided along political and…

12 CFR 204.125 - Foreign, international, and supranational entities referred to in §§ 204.2(c)(1)(iv)(E) and 204.8...

Code of Federal Regulations, 2011 CFR

2011-01-01

... Bank. Banque Centrale des Etats de l'Afrique Equatorial et du Cameroun. Banque Centrale des Etats d'Afrique del'Ouest. Conseil de l'Entente. East African Community. Organisation Commune Africaine et Malagache. Organization of African Unity. Union des Etats de l'Afrique Centrale. Union Douaniere et...

The African Organisation for Research and Training in Cancer and its conferences: a historical perspective and highlights of the Ninth International Conference, Durban, South Africa, 21–24 November 2013

PubMed Central

Williams, Christopher KO; Cristina Stefan, D; Rawlinson, Fiona; Simbiri, Kenneth; Mbulaiteye, Sam M

2014-01-01

The objectives of the African Organisation for Research and Training in Cancer (AORTIC), both at its inception in the early 1980s, and at its reactivation in 2000 following a decade of inactivity, included bringing the products of decades of advances in cancer research to African populations through international collaboration. The historical perspective provided in this report illustrates progress in achieving these objectives through successive continent-wide activities over a period of 30 years, culminating in the organisation’s most recent conference held in Durban, South Africa, 21–24 November 2013. The constant growth in the number of attendants and increasing diversity of the nations of their origin are consistent with advances, whereby the number of participants and the nations of their origin have grown from 24 in 1983 to almost 1000 in 2013, and from 14 to 70, respectively. While earlier AORTIC conferences used to assume the atmosphere of ‘jamborees’, more recent ones have morphed to problem-solving events, with the concerted collaboration of international organisations, including the World Health Organisation (WHO), International Union Against Cancer (UICC), the Africa Union (AU), the US National Cancer Institute (NCI), the International Psycho-Oncology Society (IPOS), and others. The topics of discussion at the Ninth AORTIC International Conference on Cancer in Africa in Durban were those of paramount importance for low- and middle-income countries: childhood cancers, cancers of the cervix, breast, and prostate, as well as cancer care challenges resulting from ignorance, neglect, and economic deprivation. The role of environmental factors that underlie Burkitt’s lymphoma was the subject of the Epidemiology of Burkitt Lymphoma in East-African Children and Minors Workshop, highlighting the NCI research programme in East Africa, while the Workshop on Cost Effectiveness of Treatment of Cancer in Africa surmised that treating childhood cancers is affordable in Africa in spite of widespread economic deprivation. WHO representatives emphasised the organisation’s commitment to the global control of non-communicable diseases (NCDs), including cancer, and promoted the new initiatives for the control of cervical cancer, one of the commonest and deadliest cancers in adult Africans. AU representative proffered the principles of ‘demographic dividends’ for Africa to be able to tackle its burden of NCDs. UICC, represented by its President, provided guidelines for cancer diagnosis and staging, and advised on its effort to improve global access to radiotherapy, especially in Africa, while IPOS led the discussions on mitigating the suffering that is associated with the late presentation of cancer in the region. Oral and poster presentations from various parts of the continent indicate the growth of basic science of cancer in the region, with studies revealing regional diversity in the frequencies of the triple-negative breast cancer. They also suggest a need for genome-wide association studies as well as the evaluation of single nucleotide polymorphisms that may be responsible for variable susceptibility in breast and prostate cancer in people of African descent. Finally, the AORTIC leadership announced its plan for the advancement of cancer control by intensifying cancer advocacy at all levels of governance in the region. PMID:24550997

Tracing Africa's progress towards implementing the Non-Communicable Diseases Global action plan 2013-2020: a synthesis of WHO country profile reports.

PubMed

Nyaaba, Gertrude Nsorma; Stronks, Karien; de-Graft Aikins, Ama; Kengne, Andre Pascal; Agyemang, Charles

2017-04-05

Half of the estimated annual 28 million non-communicable diseases (NCDs) deaths in low- and middle-income countries (LMICs) are attributed to weak health systems. Current health policy responses to NCDs are fragmented and vertical particularly in the African region. The World Health Organization (WHO) led NCDs Global action plan 2013-2020 has been recommended for reducing the NCD burden but it is unclear whether Africa is on track in its implementation. This paper synthesizes Africa's progress towards WHO policy recommendations for reducing the NCD burden. Data from the WHO 2011, 2014 and 2015 NCD reports were used for this analysis. We synthesized results by targets descriptions in the three reports and included indicators for which we could trace progress in at least two of the three reports. More than half of the African countries did not achieve the set targets for 2015 and slow progress had been made towards the 2016 targets as of December 2013. Some gains were made in implementing national public awareness programmes on diet and/or physical activity, however limited progress was made on guidelines for management of NCD and drug therapy and counselling. While all regions in Africa show waning trends in fully achieving the NCD indicators in general, the Southern African region appears to have made the least progress while the Northern African region appears to be the most progressive. Our findings suggest that Africa is off track in achieving the NCDs indicators by the set deadlines. To make sustained public health gains, more effort and commitment is urgently needed from governments, partners and societies to implement these recommendations in a broader strategy. While donors need to suit NCD advocacy with funding, African institutions such as The African Union (AU) and other sub-regional bodies such as West African Health Organization (WAHO) and various country offices could potentially play stronger roles in advocating for more NCD policy efforts in Africa.

Uganda: Current Conditions and the Crisis in North Uganda

DTIC Science & Technology

2010-10-06

African Union , and the United States condemned the terrorist attacks. More than 20 suspects are currently in prison. Uganda: Current Conditions...The United Nations, the African Union , and the United States condemned the terrorist attacks. More than 20 suspects are currently in prison. The...attacks took place at a rugby club and Ethiopian restaurant while people were watching the final match of the World Cup. The following day, an Al

Uganda: Current Conditions and the Crisis in North Uganda

DTIC Science & Technology

2010-12-09

Nations, the African Union , and the United States condemned the terrorist attacks. More than 20 suspects are currently in prison. Uganda: Current...An estimated 76 people, including one American, were killed and more than 80 injured. The United Nations, the African Union , and the United States...condemned the terrorist attacks. More than 20 suspects are currently in prison. The attacks took place at a rugby club and Ethiopian restaurant while

Labour Education in the World.

ERIC Educational Resources Information Center

Labour Education, 1984

1984-01-01

A group of three articles discusses training junior shop stewards in Canada, union involvement in worker education in China, and the "Dakar Declaration" of a Pan-African conference expressing international union solidarity. (SK)

The Efficacy of "Catch-Up Programmes" in South African High Schools: A Legal Jinx

ERIC Educational Resources Information Center

Nyoni, Jabulani

2013-01-01

The South African State is mandated by Sections 28(2) and 29(1) of the South African Constitution to make provision for the education of a South African child in fulfilment of the child's constitutional rights. Teacher Unions (TUs) and provincial Departments of Basic Education (DBEs) have often promised South African high school student body, in…

77 FR 5375 - National African American History Month, 2012

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-03

... women who took extraordinary risks to change our Nation for the better. During National African American... they have made to perfecting our Union. This year's theme, ``Black Women in American Culture and History,'' invites us to pay special tribute to the role African American women have played in shaping the...

The use of plants in prospecting for gold: A brief overview with a selected bibliography and topic index

USGS Publications Warehouse

Erdman, J.A.; Olson, J.C.

1985-01-01

The focal point of this report is a bibliography of 133 references and an associated topic index - both of which could be useful to geochemists attempting to locate new Au deposits. Fifty of these references originated in the Soviet Union, where most of the initial work on biogeochemical exploration for Au had been done. The 15 topics in the index range from agriculture (Au in crop plants) to silver. As an introduction to the bibliography, we have briefly described some examples of applications and difficulties in using plants. These examples are drawn from the literature and from field experience. Because of the generally low Au concentrations found in plants, the analysis of plant tissue is critical to the successful application of the biogeochemical method of prospecting. Neuron activation analysis is the most widely used method to detect Au in plants, due largely to its sensitivity; levels in the parts per billion range are easily attained. Two general types of sampling media are used in prospecting for Au: humus and living plants. Humus has been widely used in Canada, but the sampling of plants has increased there and elsewhere in recent years. Our use of douglas-fir (Pseudotsuga menziesii) at a Au-bearing stockwork in Idaho is a prime example. A maximum Au concentration of 14 ??g/g (ppm) was detected in the wood ash of this coniferous tree, well above the normal concentration of ??? 0.15 ??g/g. Among shrubs that might be useful in Au prospecting, we recommend sagebrush or wormwood (genus Artemisia), because it is extremely responsive to concealed mineralization. It has been used extensively in the Soviet Union and could be used in areas of the western United States where disseminated Au occurrences might be located. Among the problems one may encounter in using plants for Au prospecting are: (1) physiological barriers, by which many plant species simply do not absorb Au at detectable levels; (2) misconceptions of soil-plant correlations; (3) localization of Au in plant tissue; and (4) the variation of Au concentrations due to season. Despite these limitations, biogeochemical techniques can complement or replace other geochemical methods currently used. ?? 1985.

Vocational Education and Race in the Chicago Public Schools: Three Historical Case Studies and Implications for Current Reform.

ERIC Educational Resources Information Center

Green, David L.

1992-01-01

Three Chicago (Illinois) vocational high schools illustrate contrasting histories in African-American education and economic opportunity: Washburne Trade School reinforced trade union exclusion of African Americans; Dunbar Vocational High School directed African Americans into lower-paying trades, and Chicago Vocational School prepared the white…

Updates on the African Synchrotron Light Source (AfLS) Project

NASA Astrophysics Data System (ADS)

Dobbins, Tabbetha; Mtingwa, Sekazi; Wague, Ahmadou; Connell, Simon; Masara, Brian; Ntsoane, Tshepo; Norris, Lawrence; Winick, Herman; Evans-Lutterodt, Kenneth; Hussein, Tarek; Maresha, Feene; McLaughlin, Krystle; Oladijo, Philip; Du Plessis, Esna; Murenzi, Romain; Reed, Kennedy; Sette, Francesco; Werin, Sverker; Dorfan, Jonathan; Yousef, Mohammad

Africa is the only habitable continent without a synchrotron light source. A full steering committee was elected at the African Light Source (AfLS) conference on November 16-20, 2015 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The conference brought together African scientists, policy makers, and stakeholders to discuss a synchrotron light source in Africa. Firm outcomes of the Conference were a set of resolutions and a roadmap. Additionally, a collaborative proposal to promote Advanced Light Sources and crystallographic sciences in targeted regions of the world was submitted by the International Union of Pure and Applied Physics (IUPAP) and the International Union of Crystallography (IUCr) to the International Council for Science (ICSU). www.africanlightsource.org.

Inclusion of vulnerable groups in health policies: Regional policies on health priorities in Africa

PubMed Central

Eide, Arne Henning; Amin, Mutamad; MacLachlan, Malcom; Mannan, Hasheem

2013-01-01

Background If access to equitable health care is to be achieved for all, policy documents must mention and address in some detail different needs of groups vulnerable to not accessing such health care. If these needs are not addressed in the policy documents, there is little chance that they will be addressed at the stage of implementation. Objectives This paper reports on an analysis of 11 African Union (AU) policy documents to ascertain the frequency and the extent of mention of 13 core concepts in relation to 12 vulnerable groups, with a specific focus on people with disabilities. Method The paper applied the EquiFrame analytical framework to the 11 AU policy documents. The 11 documents were analysed in terms of how many times a core concept was mentioned and the extent of information on how the core concept should be addressed at the implementation level. Each core concept mention was further analysed in terms of the vulnerable group in referred to. Results The analysis of regional AU policies highlighted the broad nature of the reference made to vulnerable groups, with a lack of detailed specifications of different needs of different groups. This is confirmed in the highest vulnerable group mention being for ‘universal’. The reading of the documents suggests that vulnerable groups are homogeneous in their needs, which is not the case. There is a lack of recognition of different needs of different vulnerable groups in accessing health care. Conclusion The need for more information and knowledge on the needs of all vulnerable groups is evident. The current lack of mention and of any detail on how to address needs of vulnerable groups will significantly impair the access to equitable health care for all. PMID:28729986

Dental morphology and the phylogenetic "place" of Australopithecus sediba.

PubMed

Irish, Joel D; Guatelli-Steinberg, Debbie; Legge, Scott S; de Ruiter, Darryl J; Berger, Lee R

2013-04-12

To characterize further the Australopithecus sediba hypodigm, we describe 22 dental traits in specimens MH1 and MH2. Like other skeletal elements, the teeth present a mosaic of primitive and derived features. The new nonmetric data are then qualitatively and phenetically compared with those in eight other African hominin samples, before cladistic analyses using a gorilla outgroup. There is some distinction, largely driven by contrasting molar traits, from East African australopiths. However, Au. sediba links with Au. africanus to form a South African australopith clade. These species present five apomorphies, including shared expressions of Carabelli's upper first molar (UM1) and protostylid lower first molar (LM1). Five synapomorphies are also evident between them and monophyletic Homo habilis/rudolfensis + H. erectus. Finally, a South African australopith + Homo clade is supported by four shared derived states, including identical LM1 cusp 7 expression.

Identification of Wild Boar-Habitat Epidemiologic Cycle in African Swine Fever Epizootic.

PubMed

Chenais, Erika; Ståhl, Karl; Guberti, Vittorio; Depner, Klaus

2018-04-01

The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar-habitat.

Identification of Wild Boar–Habitat Epidemiologic Cycle in African Swine Fever Epizootic

PubMed Central

Ståhl, Karl; Guberti, Vittorio; Depner, Klaus

2018-01-01

The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar–habitat. PMID:29553337

Gender Distrust and Intimate Unions among Low-Income Hispanic and African American Women

ERIC Educational Resources Information Center

Estacion, Angela; Cherlin, Andrew

2010-01-01

This article investigates levels of generalized distrust of men among low-income non-Hispanic African American, Mexican, Puerto Rican, Dominican and non-Hispanic White women in a three-city survey. The results reveal substantial variation. Hispanics' overall levels of distrust are found to be higher than levels for either African Americans or…

African Union: Towards Good Governance, Peace and Security

DTIC Science & Technology

2012-03-15

While good governance, peace and security remain individual state responsibilities, they constitute the main pillars of Africa’s political stability and...African national leadership to drive this process.2 Political stability itself requires strong state institutional capabilities to ensure continuity

Towards the Social and Economic Promotion of Rural Women in Tanzania

ERIC Educational Resources Information Center

Kokuhirwa, Hilda

1975-01-01

The report describes the changing image of women in rural Tanzania and the various agencies responsible for their social, economic, cultural, and political promotion in rural areas, including the Tanganyika African National Union (TANU), and the Union of Women in Tanganyika (UWT). (LH)

Sub-Saharan Africa Report

DTIC Science & Technology

1986-12-29

Security Panel (Franz Kruger; THE WEEKLY MAIL, 21-27 Nov 86) 84 Cosatu Meeting Commemorates Union Dead (SAPA, 1 Dec 86) ..... 86 Textile...Workers Unions Form National Federation (SAPA, 28 Nov 86) 88 Language Blamed for Country’s Bad Image Abroad (BUSINESS DAY, 20 Nov 86) 89...Eduardo dos Santos said in Luanda on Monday that his country’s admission as a member of the African Parliamentary Union and the IPU gives Angola the

Kenya: Current Conditions and the Challenges Ahead

DTIC Science & Technology

2010-10-06

Peoples Party of Kenya Trumpet 1 NLP National Labour Party Bull (Ndume) 1 KADDU Kenya African Democratic Development Union Fruit Basket (Mavuno) 1 Kenya...Meru 6%, other African 15%, Asian, European, and Arab 1% Religions: Protestant 45%, Roman Catholic 33%, indigenous beliefs 10%, Muslim 10

Incidence and Factors Associated With Concussion Injuries at the 2011 to 2014 South African Rugby Union Youth Week Tournaments.

PubMed

Mc Fie, Sarah; Brown, James; Hendricks, Sharief; Posthumus, Michael; Readhead, Clint; Lambert, Mike; September, Alison V; Viljoen, Wayne

2016-09-01

To determine the concussion incidence and to identify factors associated with concussion in South African youth rugby union players. Prospective cohort study. Injury surveillance was completed at the South African Rugby Union Youth Week tournaments (under-13, under-16, and under-18 age groups). South African youth rugby union players. A total of 7216 players participated in 531 matches between 2011 and 2014. None. Concussion incidence was calculated per 1000 player-match-hours with 95% CIs. Poisson regression was used to calculate the incidence rate ratio (IRR) between factors (age, time period, playing position, and activity at the time of concussion) potentially associated with concussions. The concussion incidence was 6.8/1000 player-match-hours (95% CI, 5.5-8.1) across all age groups. Under-13s (IRR, 1.5; P = 0.09) and under-16s (IRR, 1.7; P = 0.03) had higher concussion incidence rates than the under-18 age group. The incidence was higher in the third (IRR, 2.1; P = 0.04) and fourth (IRR, 2.5; P = 0.01) quarters of matches compared with the first quarter. Sixty-two percent of concussions occurred in the tackle situation. The tackler had a 4-fold greater concussion rate (IRR, 4.3; P < 0.001) compared with the ball carrier. The hooker and loose forwards had higher incidence rates than several other player positions (P < 0.05). The reported concussion incidence falls within the broad range previously reported in youth rugby. The evidence highlighted in this study may contribute to targeted concussion prevention strategies and provide a baseline against which the effectiveness of future interventions can be measured.

Toward an African Maritime Economy: Empowering the African Union to Revolutionize the African Maritime Sector

DTIC Science & Technology

2011-01-01

maritime sector holistically, across its entire spectrum—improving safety and security, gover - nance, and industrial infrastructure and efficiency. There...includes the enabling elements of gover - nance, infrastructure, trade, safety, and security and plainly tells global partners where they can best...refugees, human rights, transparency, and accountability Infrastructure and Energy: transport (including maritime transport in its core function); tourism

Kenya: The December 2007 Elections and the Challenges Ahead

DTIC Science & Technology

2008-02-15

Trumpet 1 NLP National Labour Party Bull (Ndume) 1 KADDU Kenya African Democratic Development Union Fruit Basket (Mavuno) 1 KENDA Kenya National...13%, Kalenjin 12%, Kamba 11%, Kisii 6%, Meru 6%, other African 15%, Asian, European, and Arab 1% Religions: Protestant 45%, Roman Catholic 33

Kenya: Current Conditions and the Challenges Ahead

DTIC Science & Technology

2010-02-04

Kenya Tree 1 PPK Peoples Party of Kenya Trumpet 1 NLP National Labour Party Bull (Ndume) 1 KADDU Kenya African Democratic Development Union Fruit...Luhya 14%, Luo 13%, Kalenjin 12%, Kamba 11%, Kisii 6%, Meru 6%, other African 15%, Asian, European, and Arab 1% Religions: Protestant 45%, Roman

Kenya: The December 2007 Elections and the Challenges Ahead

DTIC Science & Technology

2008-09-17

NLP National Labour Party Bull (Ndume) 1 KADDU Kenya African Democratic Development Union Fruit Basket (Mavuno) 1 KENDA Kenya National Democratic...Ethnic Divisions: Kikuyu 22%, Luhya 14%, Luo 13%, Kalenjin 12%, Kamba 11%, Kisii 6%, Meru 6%, other African 15%, Asian, European, and Arab 1% Religions

Socialism and Education in Cuba and Soviet Uzbekistan

ERIC Educational Resources Information Center

Charon-Cardona, Euridice

2013-01-01

During the Cold War over half a million Asians, Africans and Latin Americans studied and graduated in the Soviet Union's universities and technical schools as part of this country's educational aid policies. Cuba was an intermediary player in the Cold War geopolitical contest between the United States and the Soviet Union, fuelled by the…

Union Quality Comparisons between Long-Term Heterosexual Cohabitation and Legal Marriage

ERIC Educational Resources Information Center

Willetts, Marion C.

2006-01-01

A longitudinal analysis is conducted on the union quality of long-term cohabiting and legally married couples using data from both waves of the National Survey of Families and Households. An analysis of racially homogamous (Anglo-American and African American) couples indicates that the cohabitors and marrieds do not differ significantly with…

Unionization and Shared Governance at Historically Black Colleges and Universities

ERIC Educational Resources Information Center

Davenport, Elizabeth

2015-01-01

Given their history of socio-economic peripheralization and continued struggles for success, one would expect African Americans--especially highly educated ones--to be adept at the various forms of mobilization and advocacy, especially that of labor unions, which have not only provided them access to opportunities but also given them a voice in…

Indian and African plate motions driven by the push force of the Réunion plume head.

PubMed

Cande, Steven C; Stegman, Dave R

2011-07-06

Mantle plumes are thought to play an important part in the Earth's tectonics, yet it has been difficult to isolate the effect that plumes have on plate motions. Here we analyse the plate motions involved in two apparently disparate events--the unusually rapid motion of India between 67 and 52 million years ago and a contemporaneous, transitory slowing of Africa's motion--and show that the events are coupled, with the common element being the position of the Indian and African plates relative to the location of the Réunion plume head. The synchroneity of these events suggests that they were both driven by the force of the Réunion plume head. The recognition of this plume force has substantial tectonic implications: the speed-up and slowdown of India, the possible cessation of convergence between Africa and Eurasia in the Palaeocene epoch and the enigmatic bends of the fracture zones on the Southwest Indian Ridge can all be attributed to the Réunion plume. ©2011 Macmillan Publishers Limited. All rights reserved

Commemorating the 50th anniversary of the founding of the Organization of African Unity (OAU) and commending its successor, the African Union.

THOMAS, 113th Congress

Rep. Bass, Karen [D-CA-37

2013-05-23

House - 06/07/2013 Referred to the Subcommittee on Africa, Global Health, Global Human Rights and International Organizations. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

76 FR 33360 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-08

..., (African American Resources in Wichita, Kansas MPS) 1301 Cleveland, Wichita, 11000395 McClinton Market, (African American Resources in Wichita, Kansas MPS) 1205 E 12th., Wichita, 11000396 LOUISIANA Calcasieu... Restricted, Kansas City, 11000399 Miller County Union Electric Administration Building--Lakeside (Boundary...

The African Standby Force: A Premature Enterprise Dictated by Circumstances?

DTIC Science & Technology

2011-03-23

offer specialized units that may be useful, but would not normally form part of a brigade group. To cater for this, the AU should include them in...also contracted African commercial airlines such as Kenya Airways or Ethiopia Airlines or other foreign companies to deploy and redeploy its

African Regional Symposium on Telematics for Development. Report and Recommendations = Colloque regional africain la telematique au service du developpement. Rapport et recommandations (Addis Ababa, Ethiopia, April 3-7, 1995).

ERIC Educational Resources Information Center

International Telecommunication Union, Geneva (Switzerland).

The African Regional Symposium on Telematics for Development was organized in view of the special educational and communication needs of Africa in a time of accelerating change and development of information technologies. The symposium brought together more than 150 African specialists, and over 40 participants from other regions and development…

Unity and Duality in Barack Obama's "A More Perfect Union"

ERIC Educational Resources Information Center

Terrill, Robert E.

2009-01-01

Faced with a racialized political crisis that threatened to derail his campaign to become the first African American president of the United States, Barack Obama delivered a speech on race titled "A More Perfect Union." He begins by portraying himself as an embodiment of double consciousness, but then invites his audience to share his…

Astronomy Landscape in Africa

NASA Astrophysics Data System (ADS)

Nemaungani, Takalani

2015-01-01

The vision for astronomy in Africa is embedded in the African Space Policy of the African Union in early 2014. The vision is about positioning Africa as an emerging hub for astronomy sciences and facilities. Africa recognized the need to take advantage of its natural resource, the geographical advantage of the clear southern skies and pristine sites for astronomy. The Pan African University (PAU) initiative also presents an opportunity as a post-graduate training and research network of university nodes in five regions of Africa and supported by the African Union. The Southern African node based in South Africa concentrates on space sciences which also includes astronomy. The PAU aims to provide the opportunity for advanced graduate training and postgraduate research to high-performing African students. Objectives also include promoting mobility of students and teachers and harmonizing programs and degrees.A number of astronomy initiatives have burgeoned in the Southern African region and these include the Southern Africa Largest Optical Telescope (SALT), HESS (High Energy Stereoscopic System), the SKA (Square Kilometre Array) and the AVN (African Very Long Baseline Interferometer Network). There is a growing appetite for astronomy sciences in Africa. In East Africa, the astronomy community is well organized and is growing - the East African Astronomical society (EAAS) held its successful fourth annual conference since 2010 on 30 June to 04 July 2014 at the University of Rwanda. Centred around the 'Role of Astronomy in Socio-Economic Transformation,' this conference aimed at strengthening capacity building in Astronomy, Astrophysics and Space Science in general, while providing a forum for astronomers from the region to train young and upcoming scientists.

A Union of Railroad Workers Sets the Pace

ERIC Educational Resources Information Center

Pullman, A. Philip Randolph

2004-01-01

During the century spanning the years 1868-1968, the African-American railroad attendant's presence on the train became an American tradition. By the 1920s, a peak decade for the railroads, more than twenty thousand African-Americans were working as porters, providing a variety services for passengers on the sleeping cars. The railroad was the…

A resolution commemorating the 50th anniversary of the founding of the Organization of African Unity (OAU) and commending its successor, the African Union.

THOMAS, 113th Congress

Sen. Coons, Christopher A. [D-DE

2013-06-10

Senate - 06/26/2013 Resolution agreed to in Senate without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

Enabling and Constraining Conditions of Professional Teacher Agency: The South African Context

ERIC Educational Resources Information Center

Long, Caroline; Graven, Mellony; Sayed, Yusuf; Lampen, Erna

2017-01-01

The South African people have a history of resistance to domination, injustice and inequality. It is therefore surprising that there has been an increase in social inequality, since the start of political democracy in 1994. Recently, the five teachers' unions refused to administer the Annual National Assessments. This action indicates some…

The Revenge of Europe: NATO and the Transatlantic Relationship in the Era of the European Union

DTIC Science & Technology

2004-04-01

AU/AF FELLOWS/NNN/2004-04 AIR FORCE FELLOWS (SDE) AIR UNIVERSITY THE REVENGE OF EUROPE NATO AND THE TRANSATLANTIC RELATIONSHIP IN THE ERA OF THE...REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE The Revenge of Europe Nato and the Transatlantic Relationship in the Era of the European...examines the transatlantic relationship and the North Atlantic Treaty Organization (NATO) in light of the rise of the European Union (EU). Recent

Methods and Techniques: An Action Learning Approach to Financial Management Training for Union Officers.

ERIC Educational Resources Information Center

Maunders, Keith

1988-01-01

The author reports on his experience in organizing and running a two-week workshop for finance officers of African trade unions. A notable aspect of this was an attempt to use action learning methodology. He illustrates the advantages and the barriers to applying the action learning philosophy in a relatively short-period, off-site training…

A Union Voice for Racial Equality: Miles Stanley and Civil Rights in West Virginia, 1957-68

ERIC Educational Resources Information Center

Fones-Wolf, Colin T.

2004-01-01

On October 15, 1959, union delegates from across West Virginia converged upon the Daniel Boone Hotel in the capital city of Charleston to participate in the West Virginia Labor Federation, AFL-CIO's second statewide constitutional convention. Charleston, at this time, remained a segregated city. So when G. William Dunn, an African-American…

The role of tephra studies in African paleoanthropology as exemplified by the Sidi Hakoma Tuff

NASA Astrophysics Data System (ADS)

WoldeGabriel, Giday; Endale, Tamrat; White, Tim D.; Thouveny, Nicolas; Hart, William K.; Renne, Paul R.; Asfaw, Berhane

2013-01-01

Beginning in the 1960s, geological and paleoanthropological exploration of the Ethiopian rift system's basins have led to the discovery and assembly of the most comprehensive record of human biological and technological change during the last 6 million years. The hominid fossils, including partial skeletons, were primarily discovered in the Afar Rift, the Main Ethiopian Rift, and in the Omo Basin of the broadly rifted zone of SW Ethiopia. The paleoanthropological research areas within the SW Afar Rift that have yielded many diverse hominid species and the oldest stone tools are, from north to south, Woranso-Mille (aff. Ardipithecus and Au. afarensis), Hadar (Au. afarensis, Homo sp.), Dikika (Au. afarensis), Gona (Ar. kadabba, Ar. ramidus, H. erectus, and oldest stone tools), Middle Awash (Ar. kadabba, Ar. ramidus, Au. anamensis, Au. afarensis, Au. garhi, H. erectus, H. rhodesiensis, H. sapiens idaltu, and the oldest paleo-butchery locality), and Galili (Au. afarensis). Additional hominid remains were discovered at Melka Kunture on the banks of the Awash River near its source along the western margin of the central part of the Main Ethiopian Rift (H. erectus), at Konso (H. erectus and A. boisei), and at the southern end of the MER, and in the Omo Basin (Au. anamensis, Au. afarensis, Au. aethiopicus, Au. boisei, H. habilis, and H. erectus). Distal and sometimes proximal tephra units interbedded within fossilifeous sedimentary deposits have become key elements in this work by providing chronological and correlative control and depositional contexts. Several regional tephra markers have been identified within the northern half of the eastern African rift valley in Ethiopia and Kenya, and in marine sediments of the Gulf of Aden Rift and the NW Indian Ocean. Out of the many regional tephra stratigraphic markers that range in age from the early Pliocene (3.97 Ma) to the late Pleistocene (0.16 Ma), the Sidi Hakoma Tuff (SHT) has been more widely identified and thoroughly characterized than any of the others. An age of 3.446 ± 0.041 Ma was determined on the SHT according to the most recent calibration, and it is the only regional stratigraphic marker whose source has been traced to a buried caldera in the central sector of the Main Ethiopian Rift. This paper describes new SHT occurrences and presents chemical and chronological results in the context of a broader review of the importance of this key marker. Moreover, the geographic distributions, probable dispersal mechanisms, and importance of regional tephra units in determining the tectonic and sedimentological processes in the different rift basins of the eastern African rift valleys are considered.

Combating Transnational Terrorism in the East African Region: The Role of the African Union Mission in Somalia

DTIC Science & Technology

2017-06-01

four main groups : prevention; disruption; prosecution; and coordination and information sharing. Under prevention, counterterrorism forces are... group has transformed into small active units capable of conducting assassinations, kidnapping, planting improvised explosive devices, and attacking...remaining challenges and highlights 1 International Crisis Group , “Working to Prevent Conflict Worldwide

Regional Higher Education Reform Initiatives in Africa: A Comparative Analysis with the Bologna Process

ERIC Educational Resources Information Center

Woldegiorgis, Emnet Tadesse; Jonck, Petronella; Goujon, Anne

2015-01-01

Europe's Bologna Process has been identified as a pioneering approach in regional cooperation with respect to the area of higher education. To address the challenges of African higher education, policymakers are recommending regional cooperation that uses the Bologna Process as a model. Based on these recommendations, the African Union Commission…

The Fight for Equal Rights: A Recruiting Poster for Black Soldiers in the Civil War.

ERIC Educational Resources Information Center

Schamel, Wynell Burroughs; West, Jean

1992-01-01

Provides teaching activities based on a recruiting poster directed at African-American men during the U.S. Civil War. Includes a brief history of the experience of African-American Union troops. Discusses document analysis, creative writing activities, oral reports, and activities for further research. Focuses on problems of racial discrimination…

"Contract to Volunteer": South African Community Health Worker Mobilization for Better Labor Protection.

PubMed

Trafford, Zara; Swartz, Alison; Colvin, Christopher J

2018-02-01

In this paper, we explore the increasing activity around labor rights for South African community health workers (CHWs). Contextualizing this activity within broader policy and legal developments, we track the emergence of sporadic mobilizations for decent work (supported by local health activist organizations) and subsequently, the formation of a CHW union. The National Union of Care Workers of South Africa (NUCWOSA) was inaugurated in 2016, hoping to secure formal and secure employment through government and the consequent labor and occupational health protections. Various tensions were observed during fieldwork in the run up to NUCWOSA's formation and raise important questions about representation, legitimacy, and hierarchies of power. We close by offering suggestions for future research in this developing space.

Ocean Pollution as a Result of Onshore Offshore Petroleum Activities in the African Gulf of Guinea Region

NASA Astrophysics Data System (ADS)

Abubakar, B.

2007-05-01

The Gulf of Guinea region is located on the Atlantic side of Africa; the sub region has a total population of approximately 190million people. It comprises of five different countries and their territorial waters, which are as follows: Nigeria, Sao Tome & Principe, Equatorial Guinea, Gabon and Cameroon. The sub region is blessed with so many types of natural resources ranging from petroleum, Natural gas, Bitumen, Uranium Diamond and Gold to mention but a few. However the region since the last two decades started attracting the World's attention as a result of the continuous increasing discoveries of new oil fields on both its on shores and off shores. In view of this extra ordinary increasing discoveries of new oil fields in the region, the Gulf of Guinea has become a "Gold rush" to the oil companies and it has so far attracted almost all the top oil firms in the world including; Exxon Mobil, Shell, Total, Texaco, Agip, Chevron, Slumberger, Stat Oil and Conoco Phillips among many other oil giants. In the more recent time even the U.S. Marine Corp have stationed their War Ship in the territorial waters of the Gulf in the name of providing protection to the "Liquid Gold" (Petroleum) underlying the beneath of the region. OIL ACTIVITIES AND ITS ASSOCIATED PROBLEMS IN THE GULF OF GUINEA As a result of the geometrically increasing oil activities in the region ranging from Drilling, Gas flaring, Bunkering and Exploration activities, there was increase in the general pollution of the region. For example recent reports released in June, 2005 by the internationally renown nongovernmental organization on environmental pollution the Netherlands based Climate Justice programme and the Nigeria's Environmental Rights Action, Under the aegis of friends of the Earth, had it that the region is ranked top on the world's total flare with Nigeria along accounting for 16 percent of the world's total flare. Another example is the increasing cases of oil spillages leading to the increasing cases of pollution of farmlands, rivers, wells and the environment in general. Apart from all these, what is even becoming more worrisome is that none of all these oil firms operating in the region is able to account on how it disposes its industrial toxic waste generated as a result of its industrial activities within the region. Finally Geological strata are adversely destroyed by seismographic activities, Sea creatures are destroyed by oil pollution and Means of livelihood of revering dwellers are often threatened by pollution. RECOMMENDATIONS After identifying how the pollution in the Gulf of Guinea region is increasing in relation to the increasing petroleum activities, I have come up with the following suggestions/recommendations. 1. AFRICAN UNION RESOLUTION The Organization of the Petroleum Exporting Countries (OPEC) in conjunction with the International Atomic Energy Agency (IAEA) should use their capacity to be able to influence the African Union (AU) to pass a resolution banning the illegal dumping of radioactive waste, Gas flaring and Costal bunkering in this part of the world. 2. RESEARCH AND INVESTIGATION The Organization of the Petroleum Exporting Countries, in conjunction with the United Nations Environmental Agency, the International Atomic Energy Agency and with the corporation of the African Union should send team of researchers to come and investigate this trend on petroleum pollution in the Gulf of Guinea region and proffer possible solutions in checking the menace.

Science in Africa: UNESCO's Contribution to Africa's Plan for Science and Technology to 2010

ERIC Educational Resources Information Center

Schneegans, Susan, Ed.; Candau, Anne, Ed.

2007-01-01

The United Nations Educational, Scientific and Cultural Organization (UNESCO) has put together this brochure on its contribution to Africa's Plan for Science and Technology to 2010 in the lead up to the forthcoming African Union Summit, in January 2007, and the meeting of African Ministers of Science and Technology November 23-24, 2006. The theme…

The Features of Development in the Pacific Countries of the African, Caribbean and Pacific Group

ERIC Educational Resources Information Center

Cuenca Garcia, Eduardo; Rodriguez Martin, Jose Antonio; Navarro Pabsdorf, Margarita

2010-01-01

In this article we present a new proposal for the measurement of development, applied to the Pacific Countries of the African, Caribbean and Pacific Group (ACP), conditional on their insularity, and with privileged relations with the European Union. Our index has been constructed attending to the criteria defined in the Goals of the Millennium…

Combating Transnational Terrorism in Kenya

DTIC Science & Technology

2005-06-17

Organizational Structure and Leadership.......................................................................13 Causes of Terrorism...Nongovernmental Organization AU Africa Union viii ILLUSTRATIONS Page Figure 1. Terrorist Organization Structure , Infrastructure, and...acknowledge the wider context that led to the growth of terrorism, which would imply an admission of the erosion of governance structures , notably weak

Cajon Valley Union School District: Changing the Culture of Learning to Empower Students. From the Field. Digital Learning Series

ERIC Educational Resources Information Center

Schwartzbeck, Terri Duggan

2013-01-01

The K-8 Cajon Valley Union School District (Cajon Valley USD) is one of forty-two school districts in the greater San Diego, California metropolitan area. Serving approximately 16,000 students, the Cajon Valley USD is extremely diverse; 36 percent of students are Hispanic, 46 percent are white, 7 percent are African American, and many students are…

Mutual benefit for foreign medical students and Chinese postgraduates: A mixed team-based learning method overcomes communication problems in hematology clerkship.

PubMed

Chen, Xianling; Chen, Buyuan; Li, Xiaofan; Song, Qingxiao; Chen, Yuanzhong

2017-03-04

Hematology is difficult for students to learn. A beneficial education method for hematology clerkship training is required to help students develop clinical skills. Foreign medical students often encounter communication issues in China. To address this issue, Chinese post-graduates from our institute are willing to assist with educating foreign students. Therefore, we propose a mixed team-based learning method (MTBL) which might overcome communication problems in hematology clerkship. Twenty-two foreign medical Students attended a 2-week hematology clerkship in Fujian Medical University Union Hospital. Twenty-one foreign African medical students were assigned randomly into two groups. Fourteen foreign African medical students were assigned to MTBL group. Each MTBL team included two foreign African medical students and one Chinese post-graduate. Seven foreign African medical students were assigned to lecture-based learning method (LBL) group, which had a foreign medical classmate from Hong Kong or Chinese intern volunteers to serve as translators. The practice test scores of MTBL were significantly higher than LBL group (p < 0.05). The MTBL group had increased motivation to prepare before class, an engaged classroom atmosphere, and an improvement in their understanding of difficult topics. Interestingly, the Chinese post-graduates also benefited from this setting, as they found that this interaction improved their communication in the English language. The mixed team-based learning method overcomes communication problems in hematology clerkship. Foreign medical students and Chinese post-graduates alike can benefit from MTBL. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(2):93-96, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

Development and validation of an epitope-blocking ELISA using an anti-haemagglutinin monoclonal antibody for specific detection of antibodies in sheep and goat sera directed against peste des petits ruminants virus.

PubMed

Bodjo, Sanne Charles; Baziki, Jean-de-Dieu; Nwankpa, Nick; Chitsungo, Ethel; Koffi, Yao Mathurin; Couacy-Hymann, Emmanuel; Diop, Mariame; Gizaw, Daniel; Tajelser, Idris Badri Adam; Lelenta, Mamadou; Diallo, Adama; Tounkara, Karim

2018-07-01

Peste des petits ruminants (PPR) is a contagious and economically important disease affecting production of small ruminants (i.e., sheep and goats). Taking into consideration the lessons learnt from the Global Rinderpest Eradication Programme (GREP), PPR is now targeted by the international veterinary community as the next animal disease to be eradicated. To support the African continental programme for the control of PPR, the Pan African Veterinary Vaccine Centre of the African Union (AU-PANVAC) is developing diagnostics tools. Here, we describe the development of a blocking enzyme-linked immunosorbent assay (bELISA) that allows testing of a large number of samples for specific detection of antibodies directed against PPR virus in sheep and goat sera. The PPR bELISA uses an anti-haemagglutinin (H) monoclonal antibody (MAb) as a competitor antibody, and tests results are interpreted using the percentage of inhibition (PI) of MAb binding generated by the serum sample. PI values below or equal to 18% (PI ≤ 18%) are negative, PI values greater than or equal to 25% (PI ≥ 25%) are positive, and PI values greater than 18% and below 25% are doubtful. The diagnostic specificity (DSp) and diagnostic sensitivity (DSe) were found to be 100% and 93.74%, respectively. The H-based PPR-bELISA showed good correlation with the virus neutralization test (VNT), the gold standard test, with a kappa value of 0.947. The H-based PPR-bELISA is more specific than the commercial kit ID Screen® PPR Competition (N-based PPR-cELISA) from IDvet (France), but the commercial kit is slightly more sensitive than the H-based PPR-bELISA. The validation process also indicated good repeatability and reproducibility of the H-based PPR-bELISA, making this new test a suitable tool for the surveillance and sero-monitoring of the vaccination campaign.

Uganda: Current Conditions and the Crisis in North Uganda

DTIC Science & Technology

2010-07-30

Union , and the United States condemned the terrorist attacks. More than 20 suspects are currently in prison. Uganda: Current Conditions and the...than 80 injured. The United Nations, the African Union , and the United States condemned the terrorist attacks. More than 20 suspects are currently in...prison. The attacks took place at a rugby club and Ethiopian restaurant while people were watching the final match of the World Cup. The following

Large-scale mitochondrial DNA analysis of native honey bee Apis mellifera populations reveals a new African subgroup private to the South West Indian Ocean islands.

PubMed

Techer, Maéva Angélique; Clémencet, Johanna; Simiand, Christophe; Preeaduth, Sookar; Azali, Hamza Abdou; Reynaud, Bernard; Hélène, Delatte

2017-06-02

The South West Indian Ocean (SWIO) archipelagos and Madagascar constitute a hotspot of biodiversity with a high rate of endemism. In this area, the endemic subspecies A. m. unicolor has been described in Madagascar. It belongs to the African lineage, one of the four described evolutionary lineages in honey bees. Despite a long beekeeping tradition and several recorded European introductions, few studies have been carried out on the diversity and proportion of honey bee subspecies. In order to identify and define which evolutionary lineages and potential sub-lineages are present in the SWIO, the COI-COII intergenic region and the ND2 gene of the mtDNA were sequenced in honey bee colonies from three archipelagos. An extensive sampling (n = 1184 colonies) was done in the Mascarene (La Réunion, Mauritius, Rodrigues), Seychelles (Mahé, Praslin, La Digue) and Comoros (Grande Comore, Mohéli, Anjouan, Mayotte) archipelagos. Islands genetic diversity was compared to newly sampled populations from Madagascar, continental African and European populations. African lineage haplotypes were found in all islands (except for Rodrigues). Madagascar, Comoros and Seychelles had 100% of A lineage, 95.5% in La Réunion and 56.1% in Mauritius. Among all African colonies detected in the SWIO, 98.1% (n = 633) of COI-COII haplotypes described the presence of the subspecies A. M. unicolor. Both genetic markers revealed i) a new private A I mitochondrial group shared by the SWIO archipelagos and Madagascar distant from continental populations; ii) the private African haplotypes for each island suggested diversity radiation in the archipelagos; iii) the detection of the Comoros archipelago as a possible contact area between insular and continental African populations. The exotic European C and M lineages were only detected in the Mascarene archipelago, but striking differences of proportion were observed among islands. Merely 4.6% of European colonies were found in La Réunion whereas Mauritius cumulated 44%. Here, among the 84 observed COI-COII haplotypes, 50 were newly described including 13 which were private to the SWIO archipelagos and Madagascar. Similarly, 24 of the 34 found ND2 haplotypes were novel which included six haplotypes particular to the SWIO populations. A new African subgroup was described in the SWIO region with mitochondrial genetic evidence that A. m. unicolor is the indigenous subspecies of the archipelagos surrounding Madagascar.

Hamate-pisiform coalition: morphology, clinical significance, and a simplified classification scheme for carpal coalition.

PubMed

Burnett, Scott E

2011-03-01

Hamate-pisiform coalition is characterized by the abnormal union of the pisiform bone and hamulus of the hamate. Because most reported cases are isolated, and literature on the subject is sparse, relatively little is known about this condition and its clinical significance. The purpose of this report is to discuss the occurrence, morphology, and frequency of hamate-pisiform coalition identified in a skeletal sample of native South Africans, and to conduct a metaanalysis of all known cases in order to clarify the sex distribution, laterality, form, and clinical significance of this condition. Five new cases (three male, two female) of hamate-pisiform coalition were identified in 527 native South Africans. Results indicate that hamate-pisiform coalition is infrequent (0.76%) but may be more likely encountered in individuals of African ancestry. Morphologically, non-osseous examples ranged in appearance from minor expressions involving pitting of an expanded hamulus base, to a variably pitted articulation between an elongated pisiform and hamulus. Osseous union between the two bones tends to extend beyond the hamulus base to adjacent areas of the hamate. Cases involving osseous union appear predisposed to fracture while ulnar neuropathy is significantly more frequent in individuals exhibiting non-osseous coalition. As both non-osseous and osseous cases can have clinical significance, awareness of the variable manifestations of this condition is necessary for hand specialists. A simplified classification system is suggested to more consistently characterize carpal coalitions. Copyright © 2010 Wiley-Liss, Inc.

The organised chaos of English adolescent rugby union: Influence of weekly match frequency on the variability of match and training loads.

PubMed

Phibbs, Padraic J; Jones, Ben; Roe, Gregory; Read, Dale; Darrall-Jones, Joshua; Weakley, Jonathon; Rock, Andrew; Till, Kevin

2018-04-01

The aims of this study were to determine the variability of weekly match and training loads in adolescent rugby union players across a competitive season, and to investigate the effect of match frequency on load distribution across different activities. Internal match and training load data (i.e. session-rating of perceived exertion (sRPE)) were collected daily from 20 players from a regional academy across a 14-week season. Data were analysed using a mixed-effects linear model, and variability was reported as a coefficient of variation (CV). Differences between 0-, 1-, 2-, and 3-match weeks were assessed using Cohen's d effect sizes and magnitude-based inferences. Mean weekly total match and training sRPE load was 1425 ± 545 arbitrary units (AU), with a between-player CV of 10 ± 6% and within-player CV of 37 ± 3%. Mean week-to-week change in total sRPE load was 497 ± 423 AU (35%), and 40% of weekly observations were outside the suggested acute:chronic workload ratio 'safe zone'. Total weekly sRPE loads increased substantially with match frequency (1210 ± 571, 1511 ± 489, and 1692 ± 517 AU, for 0-, 1-, and 2-match weeks, respectively), except for 3-match weeks (1520 ± 442 AU). Weekly match and training loads were highly variable for adolescent rugby players during the competitive season, and match frequency has a substantial effect on the distribution of loads. Therefore, match and training loads should be coordinated, monitored, and managed on an individual basis to protect players from negative training consequences, and to promote long-term athlete development.

Three (Post-Secondary Agricultural Education and Training) Challenges and the Concept of "Workforce Education Systems"

ERIC Educational Resources Information Center

Rivera, William M.

2008-01-01

The Comprehensive Africa Agriculture Development Program (CAADP) of the Africa Union's New Partnership for Africa's Development (AU/NEPAD), the International Food Policy Research Institute (IFPRI), in collaboration with the University of KwaZulu-Natal, held in January 2008, a conference on the subject of "Convergence between Social Service…

Which Wild Aardvarks Are Most Suitable for Outdoor Enclosures in Zoological Gardens in the European Union?

PubMed

Patoka, Jiří; Vejtrubová, Markéta; Vrabec, Vladimír; Masopustová, Renata

2018-01-01

The aardvark is popular in many zoological gardens in the European Union. These creatures are nocturnal, and aardvarks in the wild are known to walk distances of 4 km to 7 km per night. Despite what is known about their biology, most aardvarks are kept in zoological gardens in indoor enclosures with little space for movement. This lack of space leads to a tendency toward obesity and compromised welfare. With their wide distribution in Sub-Saharan Africa, aardvarks are perceived as thermophilic nonhuman animals. Nevertheless, some records suggest they may be able to adapt to colder climates and can be active outside their burrows when temperatures fall to 2°C. These findings suggest there may be a wild African population that is suitable for partial outdoor keeping under European climatic conditions. Therefore, a climate match was computed between the source area with aardvark occurrence and a target area of the European Union. Data revealed that the Free State, a South African province, was the area with the best climate similarity, and aardvarks from this area are recommended as suitable for the aforementioned purpose.

Search Codes for a Bibliography for the Study of African International Relations

DTIC Science & Technology

1975-01-01

Soja (1970). A high speed ln-house reference system was needed to facilitate storage, search, and retrieval of bibliographic reference materlal...REfUBLIC 0F (N0R™ KUW KUWAIT LAB LABOR UNIONS, INTERNATIONAL ASPECTS l- LA LAND LOCKED NATIONS LAO LAOS LAT LATIN AliERICA LAW I AW, INTERNATIONAL...IOCRATIC PEOPLE’S REPUBLIC OF (NORTH) KÜS KOREA (SOUTH) KUW KUWA I T LAb LABOR UNIONS, INTERNATIONAL ASPECTS LAU LA )S I.AT LATIN AiiEUICA LAN

78 FR 29380 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-20

..., (Educational Resources of Vermont MPS) 987 Union Village Rd., Norwich, 13000375 WISCONSIN Walworth County..., 82000823 Hot Spring County Bethel African Methodist Episcopal Church, 519 W. Page St., Malvern, 04000496...

Thriving public-private partnership to fortify cooking oil in the West African Economic and Monetary Union (UEMOA) to control vitamin A deficiency: Faire Tache d'Huile en Afrique de l'Ouest.

PubMed

Sablah, Mawuli; Klopp, Jennifer; Steinberg, Douglas; Touaoro, Zaoro; Laillou, Arnaud; Baker, Shawn

2012-12-01

In sub-Saharan Africa, more than 42% of children are at risk for vitamin A deficiency, and control of vitamin A deficiency will prevent more than 600,000 child deaths annually. In the West African Economic and Monetary Union (UEMOA), an estimated 54.3% of preschool-age children are vitamin A deficient and 13% of pregnant women have night blindness. To project the achievements of this West African coalition. This article documents the achievements, challenges, and lessons learned associated with the development of a public-private partnership to fortify vegetable oil in West Africa through project reports and industry assessments. National-level food consumption surveys identified cooking oil as a key vehicle for vitamin A. Stakeholders therefore advocated for the production of fortified vegetable oil at large scale, supported industrial assessments, and reinforced the capacity of cooking oil industries to implement vitamin A fortification through effective coordination of public and private partnerships tied with standards, regulations, and social marketing. Strong alliances for food fortification were established at the regional and national levels. Stakeholders also developed policies, adopted directives, built capacity, implemented social marketing, and monitored quality enforcement systems to sustain fortification for maximum public health impact. The synergy created resulted from the unique and complementary core competencies of all the partners under effective coordination. The initiative began with the 8 UEMOA member countries and now includes all 15 countries of the Economic Community of West African States (ECOWAS), plus Cameroon, Tanzania, and Mozambique, forming a sub-Saharan Africa-wide initiative on food fortification. All members of the Professional Association of Cooking Oil Industries of the West African Economic and Monetary Union (AIFO-UEMOA) now fortify edible oil with vitamin A. Through multisector cooperation, an estimated 70% of the population has access to vitamin A-fortified edible oil in participating countries. Sustainable fortification of cooking oil is now a reality in all UEMOA countries.

Isolation and molecular characterization of Chikungunya virus from the Andaman and Nicobar archipelago, India: evidence of an East, Central, and South African genotype.

PubMed

Muruganandam, N; Chaaithanya, I K; Senthil, G S; Shriram, A N; Bhattacharya, D; Jeevabharathi, G S; Sudeep, A B; Pradeepkumar, N; Vijayachari, P

2011-12-01

Chikungunya virus (CHIKV) is an Alphavirus belonging to the family Togaviridae. In 2006, CHIKV infection struck the Andaman and Nicobar archipelago, with an attack rate of 60%. There were more than 10 cases with acute flaccid paralysis simulating the Guillian Barre Syndrome. The majority of the patients presented severe joint pain. The cause for such an explosive nature of the outbreak with increased morbidity was not known. The isolation of CHIKV was attempted and succeeded from nine subjects presenting clinical symptoms of Chikungunya fever. The cDNA of all the isolates was sequenced for partial E1 and nsP1 genes. Sequences were aligned based on the double locus sequence typing concept. The phylogenetic analysis shows that sequences of Andaman isolates grouped with the East, Central, and South African genotype of virus isolates from India, Sri Lanka, and Réunion. The genetic distance between Andaman isolates and the Réunion isolates was very small. The phylogenetic analysis confirmed the origin of the isolates responsible for the first ever confirmed CHIKV outbreak in these islands to be the East, Central, and South African genotype. In this manuscript, we discuss the involvement of the East, Central, and South African strain with the Chikungunya fever outbreak in this archipelago and double locus sequence typing as a first time approach.

77 FR 33595 - African-American Music Appreciation Month, 2012

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-07

... United States of America A Proclamation As a long-cherished piece of American culture, music offers a vibrant soundtrack to the story of our people and our Union. At times when words alone could not bring us...

77 FR 2756 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-19

... Laundry, 1730-1746 E. Douglas, Wichita, 11001081. Union National Bank Building, (African American..., Roughly bounded by Mary Ave., S. 14th St., Columbus Ave., & S. University Park Dr., Waco, 11001094. [FR...

What’s in a word? The framing of health at the regional level: ASEAN, EU, SADC and UNASUR

PubMed Central

Amaya, Ana B; Rollet, Vincent; Kingah, Stephen

2015-01-01

The Association of Southeast Asian Nations, the European Union, the Southern African Development Community and the Union of South American Nations have increasingly been involved in health diplomacy in the past decade, yet little is known about how they frame health as a foreign policy issue and how this has an impact on their prioritisation of policies. For this, we conducted a review of existing grey and peer-reviewed literature that address regional integration and health, as well as a documentary review according to security, development, trade, human rights, moral/ethical reasonings and global public goods frames identified in the literature. The policy frames identified responded to the challenges these regions currently face. The Association of Southeast Asian Nation’s struggle with re-emerging diseases has led to favouring a securitisation approach to health, the European Union approaches health as a cross-cutting policy issue, the Southern African Development Community presents health as a driver for development, and while the Union of South American Nations emphasises health as a human right and addresses the social determinants of health as an ethical imperative. Overall, these policy frames were useful in analysing the framing of health in foreign policy at the regional level. However, within our analysis, we identified a new frame that approaches health as an intersectoral issue. The impact of regional organisations’ forward will depend on their ability to harness their convening power and speak in a coherent voice on health matters. PMID:26635496

What's in a word? The framing of health at the regional level: ASEAN, EU, SADC and UNASUR.

PubMed

Amaya, Ana B; Rollet, Vincent; Kingah, Stephen

2015-12-01

The Association of Southeast Asian Nations, the European Union, the Southern African Development Community and the Union of South American Nations have increasingly been involved in health diplomacy in the past decade, yet little is known about how they frame health as a foreign policy issue and how this has an impact on their prioritisation of policies. For this, we conducted a review of existing grey and peer-reviewed literature that address regional integration and health, as well as a documentary review according to security, development, trade, human rights, moral/ethical reasonings and global public goods frames identified in the literature. The policy frames identified responded to the challenges these regions currently face. The Association of Southeast Asian Nation's struggle with re-emerging diseases has led to favouring a securitisation approach to health, the European Union approaches health as a cross-cutting policy issue, the Southern African Development Community presents health as a driver for development, and while the Union of South American Nations emphasises health as a human right and addresses the social determinants of health as an ethical imperative. Overall, these policy frames were useful in analysing the framing of health in foreign policy at the regional level. However, within our analysis, we identified a new frame that approaches health as an intersectoral issue. The impact of regional organisations' forward will depend on their ability to harness their convening power and speak in a coherent voice on health matters.

The comparative incidence of reported concussions presenting for follow-up management in South African Rugby Union.

PubMed

Shuttleworth-Edwards, Ann B; Noakes, Timothy D; Radloff, Sarah E; Whitefield, Victoria J; Clark, Susan B; Roberts, Craig O; Essack, Fathima B; Zoccola, Diana; Boulind, Melissa J; Case, Stephanie E; Smith, Ian P; Mitchell, Julia L G

2008-09-01

The objective of this study was to compare the seasonal concussion incidence for school, university, club and provincial level Rugby Union players in South Africa. The study presents a retrospective statistical analysis of the number of reported concussions documented annually for groups of Rugby Union players as a proportion of those who received preseason neurocognitive assessment. Between 2002 and 2006, concussion management programs using computerized neuropsychological assessment were implemented for clinical and research purposes by psychologists in selected South African institutions involved in Rugby Union from school through to the professional level. The incidence figures were based on 175 concussive episodes reported for 165 athletes who were referred for neurocognitive assessment from a population of 1366 athletes who received preseason baseline testing. Concussion management routines varied according to the protocols adopted by the different psychologists and rugby organizations. It was expected that the incidence of concussion would vary significantly due to level of play and different management protocols. There was wide disparity in the manner in which concussion follow-up was managed by the various organizations. Within broadly comparable cohorts, tighter control was associated with a relatively higher concussion incidence for athletes per rugby playing season, with average institutional figures ranging from 4% to 14% at school level and 3% to 23% at adult level. This analysis suggests that concussion goes unrecognized and therefore incorrectly managed in a number of instances. Recommendations for optimal identification of concussed athletes for follow-up management are presented.

Leveraging Peacekeeping Partners: African Continental Progress One Sub-Region at a Time

DTIC Science & Technology

2012-11-01

mass atrocities, the members of ECOWAS were effectively forced to shift their security stance from conflict management to conflict prevention. 8 In...tack with regards to their role in conflict management across the continent. Following the formation of the AU in the early 2000’s, the AU’s new...Washington, DC: GPO, June 2012). 2 Ibid., 2. 3 Williams, Paul D, “The African Union’s Conflict Management Capabilities,” Council on Foreign

Developing new minds

NASA Astrophysics Data System (ADS)

2008-12-01

When African leaders met in Lagos, Nigeria, in April 1980 to devise a plan for economic development, they underlined the importance of science and technology with a pledge that each country should spend at least 1% of its GDP on research and development. Nearly 30 years later, the Lagos promise remains largely unfulfilled. Indeed, at a meeting of the African Union in Addis Ababa, Ethiopia, in January last year, the heads of state reiterated the need to increase funding for research and development to 1% by 2010.

Tackle-related injury rates and nature of injuries in South African Youth Week tournament rugby union players (under-13 to under-18): an observational cohort study.

PubMed

Burger, Nicholas; Lambert, Mike I; Viljoen, Wayne; Brown, James C; Readhead, Clint; Hendricks, Sharief

2014-08-12

The tackle situation is most often associated with the high injury rates in rugby union. Tackle injury epidemiology in rugby union has previously been focused on senior cohorts but less is known about younger cohorts. The aim of this study was to report on the nature and rates of tackle-related injuries in South African youth rugby union players representing their provinces at national tournaments. Observational cohort study. Four South African Youth Week tournaments (under-13 Craven Week, under-16 Grant Khomo Week, under-18 Academy Week, under-18 Craven Week). Injury data were collected from 3652 youth rugby union players (population at risk) in 2011 and 2012. Tackle-related injury severity ('time-loss' and 'medical attention'), type and location, injury rate per 1000 h (including 95% CIs). Injury rate ratios (IRR) were calculated and modelled using a Poisson regression. A χ(2) analysis was used to detect linear trends between injuries and increasing match quarters. The 2012 under-13 Craven Week had a significantly greater 'time-loss' injury rate when compared with the 2012 under-18 Academy Week (IRR=4.43; 95% CI 2.13 to 9.21, p<0.05) and under-18 Craven Week (IRR=3.52; 95% CI 1.54 to 8.00, p<0.05). The Poisson regression also revealed a higher probability of 'overall' ('time-loss' and 'medical attention' combined) and 'time-loss' tackle-related injuries occurring at the under-13 Craven Week. The proportion of 'overall' and 'time-loss' injuries increased significantly with each quarter of the match when all four tournaments were combined (p<0.05). There was a difference in the tackle-related injury rate between the under-13 tournament and the two under-18 tournaments, and the tackle-related injury rate was higher in the final quarter of matches. Ongoing injury surveillance is required to better interpret these findings. Injury prevention strategies targeting the tackle may only be effective once the rate and nature of injuries have been accurately determined. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Tackle-related injury rates and nature of injuries in South African Youth Week tournament rugby union players (under-13 to under-18): an observational cohort study

PubMed Central

Burger, Nicholas; Lambert, Mike I; Viljoen, Wayne; Brown, James C; Readhead, Clint; Hendricks, Sharief

2014-01-01

Objectives The tackle situation is most often associated with the high injury rates in rugby union. Tackle injury epidemiology in rugby union has previously been focused on senior cohorts but less is known about younger cohorts. The aim of this study was to report on the nature and rates of tackle-related injuries in South African youth rugby union players representing their provinces at national tournaments. Design Observational cohort study. Setting Four South African Youth Week tournaments (under-13 Craven Week, under-16 Grant Khomo Week, under-18 Academy Week, under-18 Craven Week). Participants Injury data were collected from 3652 youth rugby union players (population at risk) in 2011 and 2012. Outcome measures Tackle-related injury severity (‘time-loss’ and ‘medical attention’), type and location, injury rate per 1000 h (including 95% CIs). Injury rate ratios (IRR) were calculated and modelled using a Poisson regression. A χ2 analysis was used to detect linear trends between injuries and increasing match quarters. Results The 2012 under-13 Craven Week had a significantly greater ‘time-loss’ injury rate when compared with the 2012 under-18 Academy Week (IRR=4.43; 95% CI 2.13 to 9.21, p<0.05) and under-18 Craven Week (IRR=3.52; 95% CI 1.54 to 8.00, p<0.05). The Poisson regression also revealed a higher probability of ‘overall’ (‘time-loss’ and ‘medical attention’ combined) and ‘time-loss’ tackle-related injuries occurring at the under-13 Craven Week. The proportion of ‘overall’ and ‘time-loss’ injuries increased significantly with each quarter of the match when all four tournaments were combined (p<0.05). Conclusions There was a difference in the tackle-related injury rate between the under-13 tournament and the two under-18 tournaments, and the tackle-related injury rate was higher in the final quarter of matches. Ongoing injury surveillance is required to better interpret these findings. Injury prevention strategies targeting the tackle may only be effective once the rate and nature of injuries have been accurately determined. PMID:25116454

Mission, Science, and Race in South Africa; AW Roberts of Lovedale 1883-1938

NASA Astrophysics Data System (ADS)

Glass, I.S.

2016-02-01

Book Review: Biography of Alexander William Roberts. Noted educator, variable star observer and politician who represented South African "natives" in the parliament of the Union of South Africa at a time when they had no other representation.

Assessment of the Coal-Bed Gas Total Petroleum System in the Cook Inlet-Susitna region, south-central Alaska

USGS Publications Warehouse

Rouse, William A.; Houseknecht, David W.

2012-01-01

The Cook Inlet-Susitna region of south-central Alaska contains large quantities of gas-bearing coal of Tertiary age. The U.S. Geological Survey in 2011 completed an assessment of undiscovered, technically recoverable coal-bed gas resources underlying the Cook Inlet-Susitna region based on the total petroleum system (TPS) concept. The Cook Inlet Coal-Bed Gas TPS covers about 9,600,000 acres and comprises the Cook Inlet basin, Matanuska Valley, and Susitna lowland. The TPS contains one assessment unit (AU) that was evaluated for coal-bed gas resources between 1,000 and 6,000 feet in depth over an area of about 8,500,000 acres. Coal beds, which serve as both the source and reservoir for natural gas in the AU, were deposited during Paleocene-Pliocene time in mires associated with a large trunk-tributary fluvial system. Thickness of individual coal beds ranges from a few inches to more than 50 feet, with cumulative coal thickness of more than 800 feet in the western part of the basin. Coal rank ranges from lignite to subbituminous, with vitrinite reflectance values less than 0.6 percent throughout much of the AU. The AU is considered hypothetical because only a few wells in the Matanuska Valley have tested the coal-bed reservoirs, so the use of analog coal-bed gas production data was necessary for this assessment. In order to estimate reserves that might be added in the next 30 years, coal beds of the Upper Fort Union Formation in the Powder River Basin of Wyoming and Montana were selected as the production analog for Tertiary coal beds in the Cook Inlet-Susitna region. Upper Fort Union coal beds have similar rank (lignite to subbituminous), range of thickness, and coal-quality characteristics as coal beds of the Tertiary Kenai Group. By use of this analog, the mean total estimate of undiscovered coal-bed gas in the Tertiary Coal-Bed Gas AU is 4.674 trillion cubic feet (TCF) of gas.

Kenya: Current Conditions and the Challenges Ahead

DTIC Science & Technology

2010-12-09

Tree 1 PPK Peoples Party of Kenya Trumpet 1 NLP National Labour Party Bull (Ndume) 1 KADDU Kenya African Democratic Development Union Fruit Basket...15%, Asian, European, and Arab 1% Religions: Protestant 45%, Roman Catholic 33%, indigenous beliefs 10%, Muslim 10%, other 2% Languages: English

Precision Strike Annual Programs Review

DTIC Science & Technology

2008-04-16

SW For Precise Targeting 8 “Secure the High Ground” Evolution of Deployable HEL Weapons Capability THEL ACTD C5 Galaxy HEL TD C17 Globemaster Future...Security Ranger Training Maritime Ops CT Coastal SecurityERITREA African Union CA Wells, Schools MED / VETCAPs CA MED / VET Bilateral Military

Africa Adult Education. Chronologies in Commonwealth Countries.

ERIC Educational Resources Information Center

Draper, James A., Ed.

In this document, leading educators from 12 African Commonwealth countries trace the development of adult education in Africa and show how providers of adult education outside the formal education system (including government and nongovernment organizations, trade unions, women's groups, and religious organizations) have met the needs of their…

United States-Southern African Customs Union (SACU) Free Trade Agreement Negotiations: Background and Potential Issues

DTIC Science & Technology

2007-01-03

Machinery and Mechanical Appliances (primarily catalytic converters) $317 million Aircraft and Parts $267 million Ores Slag and Ash $310 million Optical...115 million Special Classification/ low value exports $121 million Miscellaneous Chemicals $113 million Articles of Zinc $85 million Pharmaceutical

Telecommunication and Information Infrastructures in the Botswana and SADC Development Strategy.

ERIC Educational Resources Information Center

Afullo, Thomas J. O.

1999-01-01

Examines the role of telecommunications and the information infrastructure in the economic development of Botswana. Highlights include the SADC (Southern African Development Community), the role of the World Bank in telecommunications in developing countries, and the International Telecommunications Union (ITU) agenda for global telecommunications…

The Possible Interrelation of TNO and Long-Period Comets by MOID Distribution

NASA Astrophysics Data System (ADS)

Guliyev, A. S.; Nabiyev, Sh. A.; Guliyev, R. A.; Dadashov, A. S.

2015-03-01

The study objects of our work were 91 TNO with diameters greater than 200 km. On the other hand, the paper used the data for 1048 and comets with aphelion and perihelion distances Q > 30 AU and q > 0.1AU, respectively, were observed until 2012. Short-perihelion comets (sporadic and concentrated in separate groups) were excluded from the analysis. If some comet split into several parties, we have taken data for only one fragment, which is marked with the letter A. Data for comets are taken from the catalog [4] and the individual Circulars International Astronomical Union, issued in period after 2008. The data for TNO, mostly borrowed from the website [5], as well as the issues of the same circulars.

Genotype imputation for African Americans using data from HapMap phase II versus 1000 genomes projects.

PubMed

Sung, Yun J; Gu, C Charles; Tiwari, Hemant K; Arnett, Donna K; Broeckel, Ulrich; Rao, Dabeeru C

2012-07-01

Genotype imputation provides imputation of untyped single nucleotide polymorphisms (SNPs) that are present on a reference panel such as those from the HapMap Project. It is popular for increasing statistical power and comparing results across studies using different platforms. Imputation for African American populations is challenging because their linkage disequilibrium blocks are shorter and also because no ideal reference panel is available due to admixture. In this paper, we evaluated three imputation strategies for African Americans. The intersection strategy used a combined panel consisting of SNPs polymorphic in both CEU and YRI. The union strategy used a panel consisting of SNPs polymorphic in either CEU or YRI. The merge strategy merged results from two separate imputations, one using CEU and the other using YRI. Because recent investigators are increasingly using the data from the 1000 Genomes (1KG) Project for genotype imputation, we evaluated both 1KG-based imputations and HapMap-based imputations. We used 23,707 SNPs from chromosomes 21 and 22 on Affymetrix SNP Array 6.0 genotyped for 1,075 HyperGEN African Americans. We found that 1KG-based imputations provided a substantially larger number of variants than HapMap-based imputations, about three times as many common variants and eight times as many rare and low-frequency variants. This higher yield is expected because the 1KG panel includes more SNPs. Accuracy rates using 1KG data were slightly lower than those using HapMap data before filtering, but slightly higher after filtering. The union strategy provided the highest imputation yield with next highest accuracy. The intersection strategy provided the lowest imputation yield but the highest accuracy. The merge strategy provided the lowest imputation accuracy. We observed that SNPs polymorphic only in CEU had much lower accuracy, reducing the accuracy of the union strategy. Our findings suggest that 1KG-based imputations can facilitate discovery of significant associations for SNPs across the whole MAF spectrum. Because the 1KG Project is still under way, we expect that later versions will provide better imputation performance. © 2012 Wiley Periodicals, Inc.

Workers' Experiences of RPL in South Africa: Some Implications for Redress, Equity and Transformation.

ERIC Educational Resources Information Center

Lugg, Rosie; Mabitla, Aubrey; Louw, Gordon; Angelis, Desi

1998-01-01

The Congress of South African Trade Unions sought to include prior learning assessment in education and training as a mechanism for redressing inequities. Issues that arose included worker representation in implementation, linkage to accreditation and training opportunities, accessibility, and support and guidance for workers. (SK)

Conflict Management Training for Peacekeepers: Assessment and Recommendations. Special Report 411

ERIC Educational Resources Information Center

Milofsky, Alison; Sany, Joseph; Lancaster, Illana; Krentel, Jeff

2017-01-01

This report examines the role of conflict management training in preparing peacekeepers for United Nations/African Union missions through an assessment of the United States Institute of Peace (USIP) Conflict Management Training for Peacekeepers program. The assessment relies on data collected through 137 semistructured interviews with returned…

FY2010 Supplemental for Wars, Disaster Assistance, Haiti Relief, and Other Programs

DTIC Science & Technology

2010-06-30

development; • Private sector development: $60.4 million; and • Economic opportunity : $8.6 million to expand credit union services, including Islamic... opportunities outside of Port-au- Prince. The Haitian government and donors agree that the current crisis provides an opportunity to correct what had become...report directs U.S. agencies to reestablish and strengthen basic and secondary educational opportunities , and to ensure that displaced children in

FY2010 Supplemental for Wars, Disaster Assistance, Haiti Relief, and Court Cases

DTIC Science & Technology

2010-06-11

development; • Private sector development: $60.4 million; and • Economic opportunity : $8.6 million to expand credit union services, including Islamic...development strategy, supported by the supplemental request, is to catalyze economic growth and provide services and opportunities outside of Port-au...Prince. The Haitian government and donors agree that the current crisis provides an opportunity to correct what had become an unsustainable urban

FY2010 Supplemental for Wars, Disaster Assistance, Haiti Relief, and Other Programs

DTIC Science & Technology

2010-08-06

efforts to administer and oversee grants awarded under the Broadband Technology Opportunity Program, fully offset from within the Department of...Economic opportunity : $8.6 million to expand credit union services, including Islamic-compliant financing. The INCLE account is implemented by the...growth and provide services and opportunities outside of Port-au- Prince. The Haitian government and donors agreed that the current crisis provides an

The view from the cotton: reconsidering the Southern Tenant Farmers' Union.

PubMed

Manthorne, Jason

2010-01-01

Having been evicted from their homes because of incentives created by the New Deal's AGricultural ADjustment Act, sharecroppers in Arkansas formed the biracial Southern Tenant Farmers' Union (STFU) in 1934. Led by socialists and radicals, the organization ultimately claimed upward of thirty thousand members and constituted an assault on the social, economic, and racial status quo of the South. Historians have celebrated the STFU, especially its commitment to biracial cooperation and equality. This article digs beneath this carefully constructed image of the union to scrutinize the internal dynamics of the movement. It revises a number of interpretations surrounding the STFU. Although the greatest obstacles to the union's success were external, it also faced internal divisions that diminished its efficacy. The STFU's decentralized structure did not foster strong connections between leadership and membership, resulting in misunderstandings. But most importantly, the union struggled to live up to its creed of biracialism and equal treatment of African Americans. Ultimately, the STFU was less an aberration that tirelessly confronted the social and racial ills of the South and more an organization that reflected some of those ills even as it grappled with them.

Animal Diseases Caused by Orbiviruses, Algeria

PubMed Central

Madani, Hafsa; Casal, Jordi; Alba, Anna; Allepuz, Alberto; Cêtre-Sossah, Catherine; Hafsi, Leila; Kount-Chareb, Houria; Bouayed-Chaouach, Nadera; Saadaoui, Hassiba

2011-01-01

Antibodies against bluetongue virus were detected in cattle, sheep, goats, and camels in Algeria in 2008. Antibodies against epizootic hemorrhagic disease virus were detected in cattle, but antibodies against African horse sickness virus were not detected in horses and mules. Epizootic hemorrhagic disease in northern Africa poses a major risk for the European Union. PMID:22172371

The Language Factor in Development Goals

ERIC Educational Resources Information Center

Bamgbose, Ayo

2014-01-01

Although development goals are usually set as targets that must be achieved in a development process, experience with development goals in Africa has tended to underscore underperformance either in terms of a shortfall in the targets attained or in terms of inadequate pursuit of specific goals. To illustrate this syndrome, the African Union's New…

Singling Black Boys to Close the Gaps

ERIC Educational Resources Information Center

Glassman, Phyllis; Roelle, Robert J.

2007-01-01

This article discusses the Ossining Union Free School District in suburban Westchester County, New York and its efforts to build successful school experiences for its black and African-American males. The leadership in the Ossining School District has made it a "moral imperative" to eradicate the achievement gap between the races in its…

FY2010 Supplemental for Wars, Disaster Assistance, Haiti Relief, and Other Programs

DTIC Science & Technology

2010-07-23

development: $60.4 million; and • Economic opportunity : $8.6 million to expand credit union services, including Islamic-compliant financing. The INCLE...supplemental request, is to catalyze economic growth and provide services and opportunities outside of Port-au- Prince. The Haitian government and donors...agree that the current crisis provides an opportunity to correct what had become an unsustainable urban-rural imbalance in the country, with the rest

Turning the Tides: President Obama and Education Reform. Education Outlook. No. 6

ERIC Educational Resources Information Center

McShane, Michael Q.

2012-01-01

The fact that president Barack Obama is an African American Democrat with a background working with poor communities has equipped him to confront teachers unions and other special interest groups in a way most other leaders have not been able to. A nearly insurmountable subgovernment in public education--labeled an "iron triangle" by…

Incarceration and the Formation and Stability of Marital Unions

ERIC Educational Resources Information Center

Lopoo, Leonard M.; Western, Bruce

2005-01-01

Rising imprisonment rates and declining marriage rates among low-education African Americans motivate an analysis of the effects of incarceration on marriage. An event history analysis of 2,041 unmarried men from the National Longitudinal Survey of Youth suggests that men are unlikely to marry in the years they serve in prison. A separate analysis…

The Balancing Act between the Constitutional Right to Strike and the Constitutional Right to Education

ERIC Educational Resources Information Center

Deacon, H. J.

2014-01-01

While the South African Constitution enshrines both children's right to a basic education and teachers' right to strike, conflict between these two often occurs when the way in which teachers' unions conduct strike actions detracts from learners' education. This article identifies the parties affected by industrial action in the school context,…

How to deal with neglected tropical diseases in the light of an African ethic.

PubMed

Metz, Thaddeus

2017-11-07

Many countries in Africa, and more generally those in the Global South with tropical areas, are plagued by illnesses that the wealthier parts of the world (mainly 'the West') neither suffer from nor put systematic effort into preventing, treating or curing. What does an ethic with a recognizably African pedigree entail for the ways various agents ought to respond to such neglected diseases? As many readers will know, a characteristically African ethic prescribes weighty duties to aid on the part of those in a position to do so, and it therefore entails that there should have been much more contribution from the Western, 'developed' world. However, what else does it prescribe, say, on the part of sub-Saharan governments and the African Union, and are they in fact doing it? I particularly seek to answer these questions here, by using the 2013-16 Ebola crisis in West Africa to illustrate what should have happened but what by and large did not. © 2017 John Wiley & Sons Ltd.

"Bessie done cut her old man": race, common-law marriage, and homicide in New Orleans, 1925-1945.

PubMed

Adler, Jeffrey S

2010-01-01

This essay examines domestic homicide in early twentieth-century New Orleans. African-American residents killed their domestic partners at eight times the rate of white New Orleanians, and these homicides were most often committed by women, who killed their partners at fifteen times the rate of white women. Common-law marriages proved to be especially violent among African-American residents. Based on nearly two hundred cases identified in police records and other sources as partner killings between 1925 and 1945, this analysis compares lethal violence in legal marriages and in common-law unions. It also explores the social and institutional forces that buffeted common-law marriages, making this the most violent domestic arrangement and contributing to the remarkably high rate of spousal homicide by African-American women in early twentieth-century New Orleans.

Assessing the Risk of African Swine Fever Introduction into the European Union by Wild Boar.

PubMed

De la Torre, A; Bosch, J; Iglesias, I; Muñoz, M J; Mur, L; Martínez-López, B; Martínez, M; Sánchez-Vizcaíno, J M

2015-06-01

The presence of African swine fever (ASF) in the Caucasus region and Russian Federation has increased concerns that wild boars may introduce the ASF virus into the European Union (EU). This study describes a semi-quantitative approach for evaluating the risk of ASF introduction into the EU by wild boar movements based on the following risk estimators: the susceptible population of (1) wild boars and (2) domestic pigs in the country of origin; the outbreak density in (3) wild boars and (4) domestic pigs in the countries of origin, the (5) suitable habitat for wild boars along the EU border; and the distance between the EU border and the nearest ASF outbreak in (6) wild boars or (7) domestic pigs. Sensitivity analysis was performed to identify the most influential risk estimators. The highest risk was found to be concentrated in Finland, Romania, Latvia and Poland, and wild boar habitat and outbreak density were the two most important risk estimators. Animal health authorities in at-risk countries should be aware of these risk estimators and should communicate closely with wild boar hunters and pig farmers to rapidly detect and control ASF. © 2013 Blackwell Verlag GmbH.

A Dyadic Analysis of Relationships and Health: Does Couple-Level Context Condition Partner Effects?

PubMed Central

Barr, Ashley B.; Simons, Ronald L.

2014-01-01

Adding to the growing literature explicating the links between romantic relationships and health, this study examined how both couple-level characteristics, particularly union type (e.g. dating, cohabiting, or marriage) and interracial pairing, and interpersonal characteristics (e.g. partner strain and support) predicted young adults’ physical and mental health. Using dyadic data from a sample of 249 young, primarily African American couples, we hypothesized and found support for the importance of couple-level context, partner behavior, and their interaction in predicting health. Interracial couples (all Black/non-Black pairings) reported worse health than monoracial Black couples. Union type, however, did not directly predict health but was a significant moderator of partner strain. That is, the negative association between partner strain and self-reported health was stronger for cohabiting and married couples versus their dating counterparts, suggesting that coresidence more so than marital status may be important for understanding partner effects on physical health. For psychological distress, however, partner support proved equally beneficial across union types. PMID:25090254

Marriage Trajectories and Health Risk Behaviors Throughout Adulthood Among Urban African Americans

PubMed Central

Green, Kerry M.; Doherty, Elaine E.; Fothergill, Kate E.; Ensminger, Margaret E.

2015-01-01

Although previous studies have identified a protective effect of marriage on risky health behaviors, gaps remain in our understanding of how marriage improves health, particularly among African Americans. This study uses longitudinal data to take selection into account and examines whether marital trajectories that incorporate timing, stability, and duration of marriage affect health risk behaviors among a community cohort of urban African Americans followed for 35 years (N = 1,049). For both men and women, we find six marital trajectories. Men and women in consistently married trajectories are less likely to smoke, drink heavily (women only), and use illegal drugs than those in unmarried or previously married trajectories. Late marrying men do not fare worse in midlife than men in earlier marrying trajectories, but late marrying women show increased risk of midlife drug use. Results suggest policies supporting marriage may have an impact on health but only if stable unions are achieved. PMID:26136611

Union Army Veterans, All Grown Up

PubMed Central

Costa, Dora L.; DeSomer, Heather; Hanss, Eric; Roudiez, Christopher; Wilson, Sven E.; Yetter, Noelle

2016-01-01

This paper overviews the research opportunities made possible by a NIA-funded program project, Early Indicators, Intergenerational Processes, and Aging. Data collection began almost three decades ago on 40,000 soldiers from the Union Army in the US Civil War. The sample contains extensive demographic, economic, and medical data from childhood to death. In recent years, a large sample of African-American soldiers and an oversampling of soldiers from major US cities have been added. Hundreds of historical maps containing public health data have been geocoded to place soldiers and their family members in a geospatial context. With newly granted funding, thousands of veterans will be linked to the demographic information available from the census and vital records of their children. PMID:28690347

Strengthening national health laboratories in sub-Saharan Africa: a decade of remarkable progress

PubMed Central

Alemnji, G. A.; Zeh, C.; Yao, K.; Fonjungo, P. N.

2016-01-01

OBJECTIVES Efforts to combat the HIV/AIDS pandemic have underscored the fragile and neglected nature of some national health laboratories in Africa. In response, national and international partners and various governments have worked collaboratively over the last several years to build sustainable laboratory capacities within the continent. Key accomplishments reflecting this successful partnership include the establishment of the African-based World Health Organization Regional Office for Africa (WHO-AFRO) Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA); development of the Strengthening Laboratory Management Toward Accreditation (SLMTA) training programme; and launching of a Pan African-based institution, the African Society for Laboratory Medicine (ASLM). These platforms continue to serve as the foundations for national health laboratory infrastructure enhancement, capacity development and overall quality system improvement. Further targeted interventions should encourage countries to aim at integrated tiered referral networks, promote quality system improvement and accreditation, develop laboratory policies and strategic plans, enhance training and laboratory workforce development and a retention strategy, create career paths for laboratory professionals and establish public–private partnerships. Maintaining the gains and ensuring sustainability will require concerted action by all stakeholders with strong leadership and funding from African governments and from the African Union. PMID:24506521

Update: Newsletter of the Outreach Services of the African, Asian, Latin American, and Russian Centers, No. 39, December, 1987.

ERIC Educational Resources Information Center

Update, 1987

1987-01-01

Four papers in this issue focus on population and urban growth in: (1) sub-Saharan Africa; (2) Latin America; (3) the Soviet Union; and (4) Japan and China. While each region has unique population features, similarities exist based on northern or southern hemisphere geographic locations and on a communist or non-communist political orientation.…

Changes in body size and physical characteristics of South African under-20 rugby union players over a 13-year period.

PubMed

Lombard, Wayne P; Durandt, Justin J; Masimla, Herman; Green, Mervin; Lambert, Michael I

2015-04-01

This study compared changes in the body size and physical characteristics of South African under-20 rugby union players over a 13-year period. A total of 453 South African under-20 players (forwards: n = 256 and backs: n = 197) underwent measurements of body mass, stature, muscular strength, endurance, and 10- and 40-m sprint times. A 2-way analysis of variance was used to determine significant differences for the main effects of position (forwards vs. backs) and time (1998-2010). The pooled data showed that forwards were significantly heavier (22%), taller (5%), and stronger (18%) than the backs. However, when 1 repetition maximum strength scores were adjusted for body mass, backs were stronger per kg body mass. Stature did not change over the 13-year period for both groups. There were, however, significant increases in muscular strength (50%), body mass (20%), and muscular endurance (50%). Furthermore, an improvement in sprint times over 40 (4%) and 10 m (7%) was evident over the period of the study. In conclusion, the players became heavier, stronger, taller, and improved their upper-body muscular endurance over the 13 years of the study. Furthermore, sprint times over 10 and 40 m improved over the same time period despite the increase in body mass. It can be speculated that the changes in physical characteristics of the players over time are possibly a consequence of (a) adaptations to the changing demands of the game and (b) advancements in training methods.

First molecular detection of Rickettsia africae in ticks from the Union of the Comoros.

PubMed

Yssouf, Amina; Socolovschi, Cristina; Kernif, Tahar; Temmam, Sarah; Lagadec, Erwan; Tortosa, Pablo; Parola, Philippe

2014-09-22

Rickettsia africae is the agent of African tick bite fever, a disease transmitted by ticks in sub-Saharan Africa. In Union of the Comoros, a recent study reported the presence of a Rickettsia africae vector but no information has been provided on the circulation of the pathogenic agent in this country. To evaluate the possible circulation of Rickettsia spp. in Comorian cattle, genomic DNA was extracted from 512 ticks collected either in the Union of the Comoros or from animals imported from Tanzania and subsequently tested for Rickettsia infection by quantitative PCR. Rickettsia africae was detected in 90% (60/67) of Amblyomma variegatum, 1% (1/92) of Rhipicephalus appendiculatus and 2.7% (8/296) of Rhipicephalus (Boophilus) microplus ticks collected in the Union of the Comoros, as well as in 77.14% (27/35) of Amblyomma variegatum ticks collected from imported cattle. Partial sequences of both bacterial gltA and ompA genes were used in a phylogenetic analysis revealing the presence of several haplotypes, all included within the Rickettsia africae clade. Our study reports the first evidence of Rickettsia africae in ticks collected from the Union of the Comoros. The data show a significant difference of infection rate of Rickettsia africae infected ticks between the Islands, with maximum rates measured in Grande Comore Island, sheltering the main entry port for live animal importation from Tanzania. The high infection levels reported herein indicate the need for an in-depth assessment of the burden of rickettsioses in the Union of the Comoros, especially among those at risk of infection, such as cattle herders.

The economic burden of time-loss injuries to youth players participating in week-long rugby union tournaments.

PubMed

Brown, James C; Viljoen, Wayne; Lambert, Mike I; Readhead, Clint; Fuller, Chelsea; Van Mechelen, Willem; Verhagen, Evert

2015-07-01

Rugby Union ("rugby") is a popular sport with high injury risk. Burden of injury is described by the incidence and severity of injury. However reports have ignored the monetary cost of injuries. Therefore the aim of this study was to describe the monetary cost associated with youth rugby injuries. This descriptive study quantified medical treatments of injured players at the South African Rugby Union Youth tournaments in 2011/2012 and the days of work parents missed as a result of the injuries. A health insurer used these data to calculate associated costs. Legal guardians of the 421 injured players were contacted telephonically on a weekly basis until they returned to play. Treatments costs were estimated in South African Rands based on 2013 insurance rates and converted to US$ using purchasing power parities. Of the 3652 players, 2% (n=71) sought medical care after the tournament. For these players, average treatment costs were high (US$731 per player, 95% CI: US$425-US$1096), with fractures being the most expensive type of injury. Players with medical insurance had higher costs (US$937, 95% CI: US$486-US$1500) than those without (US$220, 95% CI: US$145-US$302). Although a minority of players sought follow-up treatment after the tournaments, the cost of these injuries was high. Players without medical insurance having lower costs may indicate that these players did not receive adequate treatment for their injuries. Injury prevention efforts should consider injuries with high costs and the treatment of players without medical insurance. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Enhancing Human Resource Capability in the Tanzania Peoples Defense Force (TPDF)

DTIC Science & Technology

2006-06-01

Tanzania’s elephants , thus making the Selous a big attraction to tourists (Pan- African News Agency, 1999). The problem of poaching is not only confined...the Cold War and the collapse of the Soviet Union changed the strategic environment. Refugees from conflict torn areas, poaching , small arms...changed the strategic environment. Refugees from conflict torn areas, poaching , small arms proliferation, political and religious fundamentalism, drug

Impediments to the effectiveness of the United Nations-African Union Mission in Darfur (UNAMID)

DTIC Science & Technology

2010-12-01

Darfur fifteen years later, the Minsiriya murahaliin exterminated adult males, raped women , enslaved children, burned villages, and contaminated...June 19, 2010). 18 Ibid. 19 Security Council Resolution 1590 , S/RES/ 1590 (2005), 24 March 2005, para. 1. 8 immobilization of Fur opposition...Council, by Resolution 1590 , established the United Nations Mission in the Sudan (UNMIS). 133 Latent terrorist threats, heavily mined areas

Chinese Communist Strategy Toward the Islamic Countries

DTIC Science & Technology

1966-04-08

CHAPTER 1. INTRODUCTION 1 2. EGYPT AND THE ARAB MIDDLE EAST 3 Egypt and the Fertile Crescent 4 The Arabian States 7 The Sudan 9 Political ...22 3. THE NORTH AFRICAN STATES 24 The States 25 Political Dynamics 27 4. TURKEY, IRAN AND AFGHANISTAN 31 The States 31 Political Dynamics...colonialism, now almost ended, made significant contributions to interstate tensions in past years. Earlier attempts to achieve political union, long

JPRS Report, Soviet Union, International Affairs.

DTIC Science & Technology

1988-01-19

capitalism and building socialism in countries with an undeveloped economy and an archaic social structure and the conviction that it was necessary and...in countries with undeveloped econ- omies and archaic social structures and the conviction of the necessity and possibility of accelerating the...Drambyants; AZIYA I AFRIKA SEGODNYA, No 10, Oct 87] 12 Study of Russian in African Countries Described [V. Shaklein; AZIYA 1 AFRIKA SEGODNYA, No 10, Oct 87

Underdevelopment: Major Cause of Insecurity in West Africa

DTIC Science & Technology

2005-03-03

Government involvement in business in many West African countries could be another reason for the sub-region’s undeveloped industrial sector...PAGES: 30 CLASSIFICATION: Unclassified The stability of a country in terms of physical security is necessary for economic development when considered...insecurity emanate from within the borders of a country . Since the demise of communism and the collapse of the Soviet Union as a super power, there has

Quantitative risk assessment for the introduction of African swine fever virus into the European Union by legal import of live pigs.

PubMed

Mur, L; Martínez-López, B; Martínez-Avilés, M; Costard, S; Wieland, B; Pfeiffer, D U; Sánchez-Vizcaíno, J M

2012-04-01

The recent incursion and spread of African swine fever virus (ASFV) in the Russian Federation and Caucasus region, close to European Union (EU) borders, have increased the concerns regarding the probability of ASFV introduction into the EU. There are many potential routes of ASFV entry into EU, but here we specifically aimed to assess the probability of ASFV introduction by legal trade of pigs, which historically has been one of the most important ways of exotic diseases introduction into the EU. A stochastic model was used to estimate the monthly probability of ASFV introduction for each country of the EU. Results of this model suggest an annual probability for ASFV introduction in the whole EU by this way of 5.22*10(-3) , which approximately corresponds with one outbreak in 192years. The risk of ASFV introduction via live pigs was highest in Poland (69%), particularly during the months of November and December. As expected, Russian Federation is the country that most contributes to this risk, representing 68% of the overall annual risk. Methods and results presented here may be useful for informing risk-based surveillance and control programmes and, ultimately, for prevention and control of potential ASFV incursions into the EU. © 2011 Blackwell Verlag GmbH.

Sathasivan ("Saths") Cooper: Award for Distinguished Contributions to the International Advancement of Psychology.

PubMed

2014-11-01

The Award for Distinguished Contributions to the International Advancement of Psychology is given to individuals who have made sustained and enduring contributions to international cooperation and the advancement of knowledge in psychology. The 2014 recipient is Sathasivan ("Saths") Cooper. Cooper is active in global cooperation in psychology for the public and the discipline's benefit so that psychology can truly serve all of humanity. The first psychologist from outside the West to lead the International Union of Psychological Science, he is the driving force behind the Pan-African Psychology Union and continues to ensure that less-developed psychology dispensations play meaningful roles in international psychology." Cooper's award citation, biography, and a selected bibliography are presented here. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Management of non-marital fertility in two South African communities.

PubMed

Madhavan, Sangeetha; Harrison, Abigail; Sennott, Christie

2013-01-01

In this analysis, we draw on qualitative data to examine the management of non-marital fertility among young women in two rural, Black communities situated in different provinces of South Africa: KwaZulu-Natal and Mpumalanga. While the two communities share a history of economic and social disadvantage and limited access to the labour market, there are, nonetheless, distinctive features that are evident in the management of non-marital fertility. We show that young women in both communities aspire to an ideal ordering of events that places finishing education before getting married and having children, but this is not easily attained. However, there are important differences in the ways young women and their families respond to union formation and childbearing that often occurs outside of a recognised union. In Hlabisa, KwaZulu-Natal, formal processes for legitimising non-marital pregnancies through union recognition are still in place whereas, in Agincourt, Mpumalanga, more emphasis is placed on securing support and paternal recognition for the child rather than on cementing the union between the young woman and her partner. We also find that the older generation in Agincourt at times views education as a threat to marriage while this is not common in Hlabisa. Our findings have important implications for intervention programmes that often treat Black communities as homogeneous wholes.

Management of non-marital fertility in two South African communities

PubMed Central

Madhavan, Sangeetha; Harrison, Abigail; Sennott, Christie

2013-01-01

In this analysis, we draw on qualitative data to examine the management of non-marital fertility among young women in two rural, Black communities situated in different provinces of South Africa: KwaZulu–Natal and Mpumalanga. While the two communities share a history of economic and social disadvantage and limited access to the labour market, there are, nonetheless, distinctive features that are evident in the management of non-marital fertility. We show that young women in both communities aspire to an ideal ordering of events that places finishing education before getting married and having children but this is not easily attained. However, there are important differences in the ways young women and their families respond to union formation and childbearing that often occurs outside of a recognized union. In Hlabisa, formal processes for legitimising non-marital pregnancies through union recognition are still in place whereas, in Agincourt, more emphasis is placed on securing support and paternal recognition for the child rather than on cementing the union between the young woman and her partner. We also find that the older generation in Agincourt at times views education as a threat to marriage while this is not common in Hlabisa. Our findings have important implications for intervention programmes that often treat Black communities as homogeneous wholes. PMID:23600721

Strengthening national health laboratories in sub-Saharan Africa: a decade of remarkable progress.

PubMed

Alemnji, G A; Zeh, C; Yao, K; Fonjungo, P N

2014-04-01

Efforts to combat the HIV/AIDS pandemic have underscored the fragile and neglected nature of some national health laboratories in Africa. In response, national and international partners and various governments have worked collaboratively over the last several years to build sustainable laboratory capacities within the continent. Key accomplishments reflecting this successful partnership include the establishment of the African-based World Health Organization Regional Office for Africa (WHO-AFRO) Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA); development of the Strengthening Laboratory Management Toward Accreditation (SLMTA) training programme; and launching of a Pan African-based institution, the African Society for Laboratory Medicine (ASLM). These platforms continue to serve as the foundations for national health laboratory infrastructure enhancement, capacity development and overall quality system improvement. Further targeted interventions should encourage countries to aim at integrated tiered referral networks, promote quality system improvement and accreditation, develop laboratory policies and strategic plans, enhance training and laboratory workforce development and a retention strategy, create career paths for laboratory professionals and establish public-private partnerships. Maintaining the gains and ensuring sustainability will require concerted action by all stakeholders with strong leadership and funding from African governments and from the African Union. Published 2014. This article is a U.S. Government work and is in the public domain in the U.S.A.

Mainstreaming biodiversity and wildlife management into climate change policy frameworks in selected east and southern African countries

PubMed Central

Nhamo, Godwell

2016-01-01

The Rio+20 outcomes document, the Future We Want, enshrines green economy as one of the platforms to attain sustainable development and calls for measures that seek to address climate change and biodiversity management. This paper audits climate change policies from selected east and southern African countries to determine the extent to which climate change legislation mainstreams biodiversity and wildlife management. A scan of international, continental, regional and national climate change policies was conducted to assess whether they include biodiversity and/or wildlife management issues. The key finding is that many climate change policy–related documents, particularly the National Adaptation Programme of Actions (NAPAs), address threats to biodiversity and wildlife resources. However, international policies like the United Nations Framework Convention on Climate Change and Kyoto Protocol do not address the matter under deliberation. Regional climate change policies such as the East African Community, Common Market for Eastern and Southern Africa and African Union address biodiversity and/or wildlife issues whilst the Southern African Development Community region does not have a stand-alone policy for climate change. Progressive countries like Rwanda, Uganda, Tanzania and Zambia have recently put in place detailed NAPAs which are mainstream responsive strategies intended to address climate change adaptation in the wildlife sector.

"Times Are Changing": The Impact of HIV Diagnosis on Sub-Saharan Migrants' Lives in France.

PubMed

Gosselin, Anne; Lelièvre, Eva; Ravalihasy, Andrainolo; Lydié, Nathalie; Lert, France; Desgrées du Loû, Annabel

2017-01-01

Migrants account for 35% of HIV diagnoses in the European Union (ECDC/WHO 2014). Little is known about the impact of such a lifelong infection diagnosis on lives that are already disrupted by migration. In this paper, we assess the impact of HIV diagnosis on activity, union, well-being among African migrants living in France, the second group most affected by HIV after MSM. We compare it with the impact of the diagnosis of Hepatitis B, another lifelong infection affecting African migrants. We use the ANRS PARCOURS survey, a retrospective life-event survey led in 2012-2013 in 74 health structures in Paris greater area which collected 926 life histories of Sub-Saharan migrants living with HIV and 779 with Hepatitis B. We modelled the probability year by year since 18 years of age until data collection to lose one's activity, to experience a conjugal break up and degradation of well-being and we estimated the impact of migration and of HIV and Hepatitis B diagnoses on these probabilities, after adjustment on other factors, thanks to discrete-time logistic regressions. Migration entailed loss of activity and conjugal break up, though HIV diagnosis after migration did not statistically impact on these outcomes. Yet HIV diagnosis had a massive negative impact on well-being (aOR = 11.31 [4.64-27.56] for men and 5.75 [2.79-11.86] for women). This negative impact on well-being tended to diminish for persons diagnosed after 2004. The negative impact of HIV diagnosis on African migrants' well-being seems to be attenuated in the last decade, which hints at a normalization of the subjective experience of HIV diagnosis.

"Times Are Changing": The Impact of HIV Diagnosis on Sub-Saharan Migrants’ Lives in France

PubMed Central

Lelièvre, Eva; Ravalihasy, Andrainolo; Lydié, Nathalie; Lert, France; Desgrées du Loû, Annabel

2017-01-01

Background Migrants account for 35% of HIV diagnoses in the European Union (ECDC/WHO 2014). Little is known about the impact of such a lifelong infection diagnosis on lives that are already disrupted by migration. In this paper, we assess the impact of HIV diagnosis on activity, union, well-being among African migrants living in France, the second group most affected by HIV after MSM. We compare it with the impact of the diagnosis of Hepatitis B, another lifelong infection affecting African migrants. Methods We use the ANRS PARCOURS survey, a retrospective life-event survey led in 2012–2013 in 74 health structures in Paris greater area which collected 926 life histories of Sub-Saharan migrants living with HIV and 779 with Hepatitis B. We modelled the probability year by year since 18 years of age until data collection to lose one’s activity, to experience a conjugal break up and degradation of well-being and we estimated the impact of migration and of HIV and Hepatitis B diagnoses on these probabilities, after adjustment on other factors, thanks to discrete-time logistic regressions. Results Migration entailed loss of activity and conjugal break up, though HIV diagnosis after migration did not statistically impact on these outcomes. Yet HIV diagnosis had a massive negative impact on well-being (aOR = 11.31 [4.64–27.56] for men and 5.75 [2.79–11.86] for women). This negative impact on well-being tended to diminish for persons diagnosed after 2004. The negative impact of HIV diagnosis on African migrants’ well-being seems to be attenuated in the last decade, which hints at a normalization of the subjective experience of HIV diagnosis. PMID:28129342

Seven key actions to eradicate rheumatic heart disease in Africa: the Addis Ababa communiqué.

PubMed

Watkins, David; Zuhlke, Liesl; Engel, Mark; Daniels, Rezeen; Francis, Veronica; Shaboodien, Gasnat; Kango, Mabvuto; Abul-Fadl, Azza; Adeoye, Abiodun; Ali, Sulafa; Al-Kebsi, Mohammed; Bode-Thomas, Fidelia; Bukhman, Gene; Damasceno, Albertino; Goshu, Dejuma Yadeta; Elghamrawy, Alaa; Gitura, Bernard; Haileamlak, Abraham; Hailu, Abraha; Hugo-Hamman, Christopher; Justus, Steve; Karthikeyan, Ganesan; Kennedy, Neil; Lwabi, Peter; Mamo, Yoseph; Mntla, Pindile; Sutton, Chris; Mocumbi, Ana Olga; Mondo, Charles; Mtaja, Agnes; Musuku, John; Mucumbitsi, Joseph; Murango, Louis; Nel, George; Ogendo, Stephen; Ogola, Elijah; Ojji, Dike; Olunuga, Taiwo Olabisi; Redi, Mekia Mohammed; Rusingiza, Kamanzi Emmanuel; Sani, Mahmoud; Sheta, Sahar; Shongwe, Steven; van Dam, Joris; Gamra, Habib; Carapetis, Jonathan; Lennon, Diana; Mayosi, Bongani M

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) remain major causes of heart failure, stroke and death among African women and children, despite being preventable and imminently treatable. From 21 to 22 February 2015, the Social Cluster of the Africa Union Commission (AUC) hosted a consultation with RHD experts convened by the Pan-African Society of Cardiology (PASCAR) in Addis Ababa, Ethiopia, to develop a 'roadmap' of key actions that need to be taken by governments to eliminate ARF and eradicate RHD in Africa. Seven priority areas for action were adopted: (1) create prospective disease registers at sentinel sites in affected countries to measure disease burden and track progress towards the reduction of mortality by 25% by the year 2025, (2) ensure an adequate supply of high-quality benzathine penicillin for the primary and secondary prevention of ARF/RHD, (3) improve access to reproductive health services for women with RHD and other non-communicable diseases (NCD), (4) decentralise technical expertise and technology for diagnosing and managing ARF and RHD (including ultrasound of the heart), (5) establish national and regional centres of excellence for essential cardiac surgery for the treatment of affected patients and training of cardiovascular practitioners of the future, (6) initiate national multi-sectoral RHD programmes within NCD control programmes of affected countries, and (7) foster international partnerships with multinational organisations for resource mobilisation, monitoring and evaluation of the programme to end RHD in Africa. This Addis Ababa communiqué has since been endorsed by African Union heads of state, and plans are underway to implement the roadmap in order to end ARF and RHD in Africa in our lifetime.

Health, Human Capital, and African American Migration Before 1910

PubMed Central

Logan, Trevon D.

2009-01-01

Using both IPUMS and the Colored Troops Sample of the Civil War Union Army Data, I estimate the effects of literacy and health on the migration propensities of African Americans from 1870 to 1910. I find that literacy and health shocks were strong predictors of migration and the stock of health was not. There were differential selection propensities based on slave status—former slaves were less likely to migrate given a specific health shock than free blacks. Counterfactuals suggest that as much as 35 percent of the difference in the mobility patterns of former slaves and free blacks is explained by differences in their human capital, and more than 20 percent of that difference is due to health alone. Overall, the selection effect of literacy on migration is reduced by one-tenth to one-third once health is controlled for. The low levels of human capital accumulation and rates of mobility for African Americans after the Civil War are partly explained by the poor health status of slaves and their immediate descendants. PMID:20161107

JPRS Report, Soviet Union, Peoples of Asia and Africa, No. 1, January-February 1988

DTIC Science & Technology

1988-07-13

African Youth’s Assimilation of Marxism -Leninism [R.G. Landa; pp 201-203] ............ 20 ’New Multinationals’ in Developing Countries Examined [D...bureaucratic and the "new" bourgeoisie , which mineral and raw material and plantation economy, the had occupied monopoly positions, enjoyed legal and production...situation. important questions of the combination of Marxism - Leninism and the revolutionary-liberation and workers movement and the impact of

Operations at the Border: Efforts to Disrupt Insurgent Safe-Havens

DTIC Science & Technology

2011-12-16

political rival, Robert Mugabe, quickly as Ian Smith worked an agreement with Reverend Ndabaningi Sithole. J. R. T. Wood , Counter-Strike from the Sky...into Belfast was the wrong troops (mainly consisted of the Scots Guards Regiment, who as Presbyterians, appeared to naturally side with the...along tribal lines. Robert Mugabe was a member of ZANLA and its political wing the Zimbabwe African National Union (ZANU). Dr. J. R. T. Wood

Area Handbook Series: Angola: A Country Study

DTIC Science & Technology

1989-02-01

Union under Mikhail S. Gorbachev would affect the policies and practices of the MPLA-PT government. The other superpower, the Uiiited States, also... affected by the loss of land, forced labor, and stresses produced by a declining economy that they were ready to rebel on their own. The result was a...than any other industry, Diamang deeply affected the lives of its 18,000 African workers through extensive investment and the provision of social

Considerations in Establishing an Economic Community of West African States’ Defense Pact.

DTIC Science & Technology

1987-03-01

AU-AWC-87-062 UNCLASSIFIED F/G 5/2 ElhEEEEElhhhlE E ~hEEEllEllhlE IEEEEEEEllEEEE EIIEEEEEEEEEEE EllEEEEEE~lEEE ElllEEllEIh~hE 11111L2 1.0 1 6 Ma...33 Political Instability ....... .. .. . .. o .. . .. 34 Economnics ....... ... *... e ... ......... 34 A c r s. . . . . . o...41 Role and Policy.. .... . .. o . .. . .. . . .. . .. 41 Economic............................ 42 Accords, France and Libya... .......... 43 N i g e

Optimising design and cost-effective implementation of future pan-African dietary studies: a review of existing economic integration and nutritional indicators for scenario-based profiling and clustering of countries.

PubMed

Aglago, Elom K; Landais, Edwige; Zotor, Francis; Nicolas, Genevieve; Gunter, Marc J; Amuna, Paul; Slimani, Nadia

2018-02-01

Most of the African countries are undergoing a complex nutrition and epidemiologic transition associated with a rapid increase in the prevalence of diverse non-communicable diseases. Despite this alarming situation, the still limited and fragmented resources available in Africa impede the implementation of effective action plans to tackle the current and projected diet-disease burden. In order to address these common needs and challenges, the African Union is increasingly supporting continental approaches and strategies as reflected in the launching of the Agenda 2063 and the African regional nutrition strategy 2015-2025, among others. To assure the successful implementation of pan-African nutritional and health initiatives, cost-effective approaches considering similarities/disparities in economy, regional integration, development and nutritional aspects between countries are needed. In the absence of pre-existing models, we reviewed regional economic integration and nutritional indicators (n 13) available in international organisations databases or governmental agencies websites, for fifty-two African countries. These indicators were used to map the countries according to common languages (e.g. Arabic, English, French, Portuguese), development status (e.g. human development index), malnutrition status (e.g. obesity) and diet (e.g. staples predominantly based on either cereals or tubers). The review of the indicators showed that there exist similarities between African countries that can be exploited to benefit the continent with cross-national experiences in order to avoid duplication of efforts in the implementation of future pan-African health studies. In addition, including present and future nutrition surveillance programmes in Africa into national statistical systems might be cost-effective and sustainable in the longer term.

The IAU Office of Astronomy Development

NASA Astrophysics Data System (ADS)

Mauduit, Jean-Christophe; Govender, K.

2014-01-01

The International Astronomical Union (IAU), the largest body of professional astronomers in the world, has set up the Office of Astronomy for Development (OAD) in partnership with the South African National Research Foundation (NRF). The OAD is located at the South African Astronomical Observatory (SAAO) in Cape Town. Its mission is to realise the IAU's Strategic Plan, which aims to use astronomy as a tool for development. It focuses on the following three main areas: "Universities and Research", "Children and Schools" and "Public Outreach". Eighteen projects worldwide have been funded for 2013 and are currently under way. More will be starting in 2014. The OAD is also setting up regional nodes and language expertise centres around the world. This presentation will describe the ongoing activities of the OAD and plans for the future.

Violences conjugales à Antananarivo (Madagascar): un enjeu de santé publique

PubMed Central

Gastineau, Bénédicte; Gathier, Lucy

2012-01-01

Introduction La violence conjugale a été étudiée dans beaucoup de pays développés mais peu en Afrique subsaharienne. Madagascar est un pays où ce phénomène est peu documenté. Méthodes En 2007, une enquête sur la violence conjugale à Antananarivo (ELVICA) a été menée sur la violence conjugale envers les femmes dans la capitale malgache. ELVICA a interrogé 400 femmes en union, de 15 à 59 ans. Des informations sur les caractéristiques démographiques, socioéconomiques des couples ont été collectées ainsi que sur les actes de violences physiques des hommes sur leurs épouses. L’objectif de cet article est d’identifier les facteurs de risques de la violence conjugale grave, celle qui a des conséquences sur la santé physique des femmes. Résultats Trente-cinq pour cent des femmes qui ont déclaré avoir subi au moins une forme de violence physique au cours des 12 mois précédent l’enquête. Presque la moitié (46%) des femmes violentées ont déclaré avoir déjà eu des hématomes, et environ un quart (23%) des plaies avec saignement. Vingt-deux pour cent ont déjà dû consulter un médecin. Parmi les nombreuses variables socioéconomiques et démographiques testées, quelques-unes sont associées positivement au risque de violence conjugale grave: le fait pour une femme d’être en union consensuelle et d’avoir une activité professionnelle. Il y aussi un lien entre la violence subie et l’autonomie des femmes (liberté accordée par le mari de travailler, de circuler, de voir sa famille). Conclusion A Madagascar, comme ailleurs, la lutte contre les violences conjugales est un élément majeur de l’amélioration du statut et de la santé des femmes. PMID:22514757

Technical Evaluation Report on the Fluid Dynamics Panel Symposium on Validation of Computational Fluid Dynamics

DTIC Science & Technology

1989-05-01

separately each of the papers presented and makes general comments on the seven major topic sessions. In addition, a Poster Presentation was reviewed in...Appendix to this report. The Poster Papers, also listed in an Appendix, are published in CP437 Volume I. Le pr6sent rapport fait le point et donne une...ConfErence AGARD CP 437 Volume I dont une liste en est donn6e h I’annexe au pr6sent rapport. Une liste des r6unions d’information/exposition est

Séroprévalence et facteurs associés au VIH et aux hépatites virales B et C dans la ville de Bafoussam au Cameroun

PubMed Central

Mbopi-Keou, Francois-Xavier; Nkala, Isabelle Vanessa Monthe; Kalla, Ginette Claude Mireille; Nguefack-Tsague, Georges; Kamga, Hortense Gonsu; Noubom, Michel; Mvogo, Côme Ebana; Sosso, Maurice Aurelien

2015-01-01

Introduction L'objectif de ce travail était de déterminer la séroprévalence et les facteurs associés au VIH et aux hépatites virales B et C dans la ville de Bafoussam au Cameroun. Méthodes Il s'agissait d'une étude descriptive et analytique réalisée de février 2012 à Juin 2012 dans la ville de Bafoussam au Cameroun. Pour cette étude, nous avons obtenu une clairance éthique. Résultats Au total, 982 personnes ont été dépistées pour le VIH et les hépatites virales B et C. Les femmes représentaient 56,3% des personnes dépistées. La tranche d’âge la plus représentée était celle des 20 à 24 ans. L’âge médian était de 34,5 ans. Les prévalences du VIH, de l'AgHBs, et de l'Ac anti HCV étaient respectivement de 6,0%, 4,1%, et 0,4%. La prévalence du VIH était 2 fois plus élevée parmi les femmes que les hommes avec 8,1% contre 3,5% (p=0,01). Les prévalences les plus élevées ont été observées chez les personnes de 30 à 34 ans, 40 à 44 ans avec 15,0% et 11,5% (p=0,01), les personnes sans emploi avec 11,1% (p<0,001) et les personnes en union libre avec 17,9% (p=0,000). La prévalence du VIH n’était pas directement liée aux comportements et pratiques sexuels de la population de l’étude. On enregistrait une prévalence élevée de 29,3% chez les individus ayant déclaré avoir au moins une infection sexuellement transmissible (p=0,000). Conclusion Il apparait urgent de mettre en place des stratégies de prévention contre le VIH, les hépatites virales et les facteurs associés au Cameroun. PMID:26113899

How plume-ridge interaction shapes the crustal thickness pattern of the Réunion hotspot track

NASA Astrophysics Data System (ADS)

Bredow, Eva; Steinberger, Bernhard; Gassmöller, Rene; Dannberg, Juliane

2017-08-01

The Réunion mantle plume has shaped a large area of the Earth's surface over the past 65 million years: from the Deccan Traps in India along the hotspot track comprising the island chains of the Laccadives, Maldives, and Chagos Bank on the Indian plate and the Mascarene Plateau on the African plate up to the currently active volcanism at La Réunion Island. This study addresses the question how the Réunion plume, especially in interaction with the Central Indian Ridge, created the complex crustal thickness pattern of the hotspot track. For this purpose, the mantle convection code ASPECT was used to design three-dimensional numerical models, which consider the specific location of the plume underneath moving plates and surrounded by large-scale mantle flow. The results show the crustal thickness pattern produced by the plume, which altogether agrees well with topographic maps. Especially two features are consistently reproduced by the models: the distinctive gap in the hotspot track between the Maldives and Chagos is created by the combination of the ridge geometry and plume-ridge interaction; and the Rodrigues Ridge, a narrow crustal structure which connects the hotspot track and the Central Indian Ridge, appears as the surface expression of a long-distance sublithospheric flow channel. This study therefore provides further insight how small-scale surface features are generated by the complex interplay between mantle and lithospheric processes.

East African Crisis Response: Shaping Ethiopian Peace Force for Better Participation in Future Peace Operations

DTIC Science & Technology

2006-12-01

security policy and the need for establishment of a single continental army were stressed during the Inaugural Summit of the AU held in Durban...equipment and orientation" as key issues in interoperability within ECOMOG, stressing the need for bilingual language training in the region, as...hexed them as if they were fighting the superhuman. The Ethiopian left no tracks shed no blood and spoke always in an unknown tongue. Lack of

Synchrotron light sources in developing countries

DOE PAGES

Mtingwa, Sekazi K.; Winick, Herman

2018-03-21

Here, we discuss the role that synchrotron light sources, such as SESAME, could play in improving the socioeconomic conditions in developing countries. After providing a brief description of a synchrotron light source, we discuss the important role that they played in the development of several economically emerging countries. Then we describe the state of synchrotron science in South Africa and that country’s leadership role in founding the African Light Source initiative. Next, we highlight a new initiative called Lightsources for Africa, the Americas & Middle East Project, which is a global initiative led by the International Union of Pure andmore » Applied Physics and the International Union of Crystallography, with initial funding provided by the International Council for Science. Finally, we comment on a new technology called the multibend achromat that has launched a new paradigm for the design of synchrotron light sources that should be attractive for construction in developing countries.« less

Synchrotron light sources in developing countries

NASA Astrophysics Data System (ADS)

Mtingwa, Sekazi K.; Winick, Herman

2018-03-01

We discuss the role that synchrotron light sources, such as SESAME, could play in improving the socioeconomic conditions in developing countries. After providing a brief description of a synchrotron light source, we discuss the important role that they played in the development of several economically emerging countries. Then we describe the state of synchrotron science in South Africa and that country’s leadership role in founding the African Light Source initiative. Next, we highlight a new initiative called Lightsources for Africa, the Americas & Middle East Project, which is a global initiative led by the International Union of Pure and Applied Physics and the International Union of Crystallography, with initial funding provided by the International Council for Science. Finally, we comment on a new technology called the multibend achromat that has launched a new paradigm for the design of synchrotron light sources that should be attractive for construction in developing countries.

Synchrotron light sources in developing countries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mtingwa, Sekazi K.; Winick, Herman

Here, we discuss the role that synchrotron light sources, such as SESAME, could play in improving the socioeconomic conditions in developing countries. After providing a brief description of a synchrotron light source, we discuss the important role that they played in the development of several economically emerging countries. Then we describe the state of synchrotron science in South Africa and that country’s leadership role in founding the African Light Source initiative. Next, we highlight a new initiative called Lightsources for Africa, the Americas & Middle East Project, which is a global initiative led by the International Union of Pure andmore » Applied Physics and the International Union of Crystallography, with initial funding provided by the International Council for Science. Finally, we comment on a new technology called the multibend achromat that has launched a new paradigm for the design of synchrotron light sources that should be attractive for construction in developing countries.« less

Ungoverned Spaces and the Survival of Terrorist Groups in Africa: A Case Study of the Lords Resistance Army

DTIC Science & Technology

2015-12-01

example a World Bank report in 2011 indicated that “54.7 percent of the nation’s population was lives in abject poverty.”230 Unemployment and...AIAI Al- Itihad Al-Islami AIS Islamic Salvation Army AMISOM African Union Mission in Somalia AQAP Al Qaeda in the Arabian Peninsula AQIM Al... unemployment of young populations, porous borders, religious extremism and bad governance, among other factors, are always at play in the growth and survival of

How Can the United States Counter China’s Growing Influence in Africa through Non-kinetic Means?

DTIC Science & Technology

2011-03-21

summer of 1995 at the Rugby World Cup when Springbok Captain, Franc;:ois Pienaar raised the Webb Ellis Cup standing next to President Nelson Mandela of...the Rugby World Cup tournament to avoid a civil war and reconcile with the Afrikaners. The second muse was the book Unrestricted Warfare written by...53 Labor unions in the RSA put pressure on the South African government to engage the World Trade Organization (WTO) to protect local manufactures.54

African Swine Fever Virus: a new old enemy of Europe

PubMed

Cisek, Agata A; Dąbrowska, Iwona; Gregorczyk, Karolina P; Wyżewski, Zbigniew

2016-10-01

African swine fever (ASF) is a highly contagious viral disease of swine with a mortality rate approaching 100 percent. African Swine Fever Virus (ASFV) is a double-stranded DNA virus with a complex molecular structure. Its large genome, encoding multiple virulence factors, allows for efficient replication, which takes place predominantly in the cytoplasm of monocytes and macrophages. Also, ASFV has the ability to interfere with cell signalling pathways, which leads to various modulations in the synthesis profiles of interferon and other cytokines. Sustained viremia favours the persistence of virions in blood and tissues of the convalescents, and the extended circulation of ASFV within the herd. ASFV has been spreading in the Caucasus since 2007, and in 2014 reached the eastern territory of the European Union. Outbreaks pose an economical threat to native pig rearing, especially since a single point source may easily develop into an epizootic event. There is currently no effective vaccine nor treatment for ASF, and eradication is possible only by prevention or the slaughter of diseased animals. This review paper summarizes the current state of knowledge about ASFV.

'Main' girlfriends, girlfriends, marriage, and money: the social context of HIV risk behaviour in sub-Saharan Africa.

PubMed

Meekers, D; Calvès, A E

1997-01-01

Research on African societies documents the magnitude of the AIDS epidemic, and shows that at younger ages women are more likely to be affected than men. Young African women are particularly vulnerable to HIV infection because sexual relations with men are an important means to achieve social and economic status, and for some women they are necessary for survival. Many African adolescents and young adults engage in premarital sexual relationships, either sequentially or simultaneously. Unmarried African males commonly have a 'main' girlfriend whom they expect to marry, and one or more other girlfriends, for whom there are no such expectations; some females have similar strategies. This study uses focus-group data from Cameroun to describe popular types of premarital sexual relationships, and to examine gender differentials in the motivations for engaging in such relationships and in perceptions of the factors that affect the marriage prospects of these premarital relationships. Economic need leads many young women to use premarital sexual relations for economic support, despite high levels of HIV infection. These findings help inform policy-makers and program managers in Africa about gender differentials in the motivations for engaging in premarital sexual unions, which in turn can help improve the design and implementation of social and health policies and programs.

Historical mitochondrial diversity in African leopards (Panthera pardus) revealed by archival museum specimens.

PubMed

Anco, Corey; Kolokotronis, Sergios-Orestis; Henschel, Philipp; Cunningham, Seth W; Amato, George; Hekkala, Evon

2018-04-01

Once found throughout Africa and Eurasia, the leopard (Panthera pardus) was recently uplisted from Near Threatened to Vulnerable by the International Union for the Conservation of Nature (IUCN). Historically, more than 50% of the leopard's global range occurred in continental Africa, yet sampling from this part of the species' distribution is only sparsely represented in prior studies examining patterns of genetic variation at the continental or global level. Broad sampling to determine baseline patterns of genetic variation throughout the leopard's historical distribution is important, as these measures are currently used by the IUCN to direct conservation priorities and management plans. By including data from 182 historical museum specimens, faecal samples from ongoing field surveys, and published sequences representing sub-Saharan Africa, we identify previously unrecognized genetic diversity in African leopards. Our mtDNA data indicates high levels of divergence among regional populations and strongly differentiated lineages in West Africa on par with recent studies of other large vertebrates. We provide a reference benchmark of genetic diversity in African leopards against which future monitoring can be compared. These findings emphasize the utility of historical museum collections in understanding the processes that shape present biodiversity. Additionally, we suggest future research to clarify African leopard taxonomy and to differentiate between delineated units requiring monitoring or conservation action.

Etude descriptive et analytique du cancer de l’œsophage au Togo

PubMed Central

Oumboma, Bouglouga; Mawuli, Lawson-Ananissoh Laté; Aklesso, Bagny; Laconi, Kaaga; Datouda, Redah

2014-01-01

Introduction Décrire les aspects épidémiologiques, cliniques, endoscopiques et histologiques du cancer de l’œsophage (CO) au Togo. Méthodes Il s'agit d'une étude rétrospective descriptive et analytique menée sur 8 ans (Janvier 2005-Décembre 2012) dans le service d'hépato-gastroentérologie (HGE) du CHU Campus de Lomé. Etaient inclus les dossiers des patients hospitalisés pour CO confirmé histologiquement. Résultats Sur 8 ans, 24 patients remplissant nos critères d'inclusion ont été retenus soit 3cas de CO par an et 0,55% des hospitalisations. L’âge moyen des patients était de 57,08 ans (extrêmes: 32 et 82 ans). La dysphagie et l’épigastralgie étaient les motifs d'hospitalisation les plus rencontrés. L'alcool (n=15), le tabac (n=13) étaient les facteurs de risque les plus présents. A la fibroscopie, les lésions étaient ulcéro-bourgeonnantes et hémorragiques (n=12), ulcéro-bourgeonnantes (n=5); ces lésions siégeaient au niveau du 1/3 inférieur (n= 11), à l'union 1/3 supérieur 1/3moyen de l’œsophage (n= 13) et aucun au niveau du 1/3 supérieur. Seize lésions étaient des carcinomes épidermoïdes et 3 des adénocarcinomes. L’évolution dans le service a été fatale dans 2cas; 16 patients avaient été transférés en chirurgie pour des soins palliatifs et 5 patients (20,8%) étaient perdus de vue. Conclusion Le CO semble en augmentation au Togo. L'alcool et le tabac sont les facteurs de risque et le pronostic sévère dans notre série est lié au retard diagnostic. Son dépistage précoce passe par une consultation rapide devant toute dysphagie chez un sujet de 50 ans et plus. PMID:25883742

Community-level intimate partner violence and the circumstances of first sex among young women from five African countries.

PubMed

Gómez, Anu Manchikanti; Speizer, Ilene S

2010-06-19

Gender-based violence is an important risk factor for adverse reproductive health (RH). Community-level violence may inhibit young women's ability to engage in safer sexual behaviors due to a lack of control over sexual encounters. Few studies examine violence as a contextual risk factor. Using nationally representative data from five African countries, the association between community-level physical or sexual intimate partner violence (IPV) and the circumstances of first sex (premarital or marital) among young women (ages 20-29) was examined. In Mali, and Kenya bivariate analyses showed that young women who had premarital first sex were from communities where a significantly higher percentage of women reported IPV experience compared to young women who had marital first sex. Multivariate analyses confirmed the findings for these two countries; young women from communities with higher IPV were significantly more likely to have had premarital first sex compared to first sex in union. In Liberia, community-level IPV was associated with a lower risk of premarital sex as compared to first sex in union at a marginal significance level. There was no significant relationship between community-level IPV and the circumstances of first sex in the Democratic Republic of Congo or Zimbabwe. These findings indicate that context matters for RH. Individualized efforts to improve RH may be limited in their effectiveness if they do not acknowledge the context of young women's lives. Programs should target prevention of violence to improve RH outcomes of youth.

Perceptions and viewpoints on proceedings of the Fifteenth Assembly of Heads of State and Government of the African Union Debate on Maternal, Newborn and Child Health and Development, 25-27 July 2010, Kampala, Uganda.

PubMed

Sambo, Luis Gomes; Kirigia, Joses Muthuri; Ki-Zerbo, Georges

2011-06-13

Out of 358000 maternal deaths that occurred globally in 2008, 57.8% occurred in continental Africa. Africa had a maternal mortality ratio of 590 compared to 14 in developed regions, 68 in Latin America and Caribbean, and 190 in Asia. This article reflects on the discussions held during the Fifteenth Assembly of the Heads of State and Government of the African Union on the reasons why the maternal mortality ratio is so high in Africa and what can be done to reduce it. Methods employed included panel and open public discussions among the Heads of State and Government of the African Union. The article uses the WHO health systems strengthening framework, which consists of six pillars (information systems, leadership and governance, health workforce, financing, and medical products, vaccines and technologies, and health services) to describe the proceedings of the discussions. The high maternal mortality ratios in countries were attributed to weak national health information systems; leadership and governance challenges related to poverty, health illiteracy, poor transport networks and communications infrastructure, risky cultural practices, armed conflicts and domestic violence, dearth of women empowerment; inadequate levels of skilled birth attendants; inadequate domestic and external funding; stock-outs of consumable inputs; and limited coverage of maternal and child health interventions.In order to accelerate progress towards MDGs 4 and 5, the Heads of State and Government recommended that countries should make maternal deaths notifiable and institutionalize maternal death audits; develop, fund and implement policies and strategies geared at improving maternal, newborn and child health; accelerate inter-sectoral action to address the broad health determinants; increase the number of skilled birth attendants; fulfil commitment to allocate at least 15% of the national budget to the health sector and allocate adequate resources to prevent stock-outs of essential medicines and reproductive health commodities; leverage health promotion approaches to raise national awareness; and ensure that there is a health centre within a radius of four kilometres equipped to provide good quality integrated maternal, newborn and child health services. There was consensus among the discussants that there was urgent need to speed up actions for strengthening health systems to improve coverage of maternal, newborn and child health services; and to address broad determinants of women, newborn and children's health for sustained improvements in health and other development goals.

A Feminist Intervention That Hurt Women: Biological Differences, Ergonomics, and Occupational Health: Une intervention féministe qui a nui aux femmes: différences biologiques, égalité, ergonomie et santé au travail.

PubMed

Messing, Karen

2017-11-01

The University of Québec in Montréal has agreements with trade unions providing access to university resources. Researchers involved in this program worked in partnership with union women's and health and safety committees for more than twenty years. Not all studies succeeded in improving women's working conditions. One joint project involved observational studies of tasks done by health-care workers, complemented by interviews and questionnaires. We found that task assignments, movements, postures, and work-related musculoskeletal disorders varied by gender/sex and made recommendations for change. However, issues of pay equity, spending on health care, and contracting-out of "ancillary work" were salient. Researchers learned that in the absence of changes in power relationships in the workplace, women may be disadvantaged by denial as well as by exaggeration of female-male differences. Men may also be at risk when their gender is invisible. We suggest some feminist approaches to workplace solutions and some pathways for research. Résumé L'Université du Québec à Montréal a signé avec des centrales syndicales des ententes leur donnant un accès à des ressources universitaires. Des chercheures ont travaillé en partenariat avec des comités syndicaux de condition des femmes et de santé-sécurité au travail pendant plus de 25 ans, mais ce ne sont pas toutes les études qui ont abouti à des améliorations. Un projet concernait des observations du travail d'employé.e.s du secteur de la santé, dont les tâches, mouvements, et postures variaient selon le genre/sexe. Nous avons recommandé des transformations, mais des enjeux d'équité salariale, de coûts et de sous-traitance y ont fait obstacle. Les chercheures ont appris qu'en l'absence de transformation des rapports de pouvoir au travail, le déni des différences hommes-femmes, autant que leur exagération, peut désavantager les travailleuses (et les travailleurs). Nous suggérons des approches féministes aux solutions pour le milieu de travail, ainsi que des pistes de recherche.

Le craton ouest-africain et le bouclier guyanais: un seul craton au Protérozoïque inférieur?

NASA Astrophysics Data System (ADS)

Caen-Vachette, Michelle

Geochronological and paleomagnetism data for southern West African craton and Guyana shield in South America, are concordant and suggest the existence of a large unit grouping them during Archean and Lower Proterozoic times. The paleomagnetism data allow to put on a single line, the Zednes (Mauritania), Sassandra (Ivory Coast) and Guri (Venezuela) fault zones, the mylonites of which were dated 1670 Ma. This age reflects the end of the eburnean-transamazonian shearing tectonic, which affected the large West Africa-Guyana unit. This line separates the western Archean domain from the eastern lower Proterozoic one; thence it is possible to correlate the Sasca (Ivory Coast) and Pastora (Venezuela) areas. Archean relics have been found in mobile pan-african-bresiliano zones which surround the Precambrian cratons; this fact suggests the existence of still more extended Archean craton than defined above.

Counterinsurgency in Somalia: Lessons Learned from the African Union Mission in Somalia, 2007-2013

DTIC Science & Technology

2014-09-01

J S O U R e p o rt 1 4 -5 C o u n te rin s u rg e n c y in S o m a lia B ru to n / W illia m s Counterinsurgency...REPORT unclassified b. ABSTRACT unclassified c . THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Joint...Force Ret., Resident Senior Fellows Anna-Marie Wyant, M.A., English, JSOU Press Editor Editorial Advisory Board Roby C . Barrett Ph.D., Middle

CTC Sentinel. Volume 2, Issue 3, March 2009. Somalia’s New Government and the Challenge of Al-Shabab

DTIC Science & Technology

2009-03-01

Somalia’s New Government and the Challenge of Al-Shabab By David H. Shinn Contents FEATURE ARTICLE 1 Somalia’s New Government and the Challenge...2009 to 00-00-2009 4. TITLE AND SUBTITLE Somalia?s New Government and the Challenge of Al-Shabab 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...forces and African Union peacekeepers.22 In a mid- February 2009 video, Abu Yahya called on Somalis to oppose the new Somali government and attack

I am AmeriBritSouthAfrican-Zambian: Multidimensional remote acculturation and well-being among urban Zambian adolescents.

PubMed

Ferguson, Yuna L; Ferguson, Kim T; Ferguson, Gail M

2017-02-01

One impact of globalisation is that adolescents today are frequently exposed to the values, attitudes and norms of other nations without leaving their own backyards. This may lead to remote acculturation-cultural and psychological changes experienced by non-migrant individuals having indirect and/or intermittent contact with a geographically separate culture. Using quantitative and qualitative data, we examined multidimensional remote acculturation among 83 urban Zambian adolescents who are routinely exposed to U.S., U.K. and South African cultures through traditional and social media and materials/goods. Cluster analyses showed 2 distinct groups of adolescents. "Traditional Zambians, TZs" (55.4%) were significantly more oriented towards Zambian culture and reported a higher level of obligation to their families and greater interdependent self-construal compared with "Westernised Multicultural Zambians, WMZs" (44.6%), who were more oriented towards U.S., U.K. and South African cultures. Furthermore, remote acculturation predicted somewhat lower life satisfaction among WMZs. These results demonstrate that individuals' behaviours, values and identity may be influenced by multiple geographically distant cultures simultaneously and may be associated with psychological costs. © 2015 International Union of Psychological Science.

DSM-IV 12-month and lifetime major depressive disorder and romantic relationships among African Americans.

PubMed

Taylor, Robert Joseph; Chae, David H; Chatters, Linda M; Lincoln, Karen D; Brown, Edna

2012-12-15

This brief report examines the association between marital and relationship status and 12-month and lifetime prevalence of major depressive disorder (MDD) among African Americans. Previous work has found that adults with major depressive disorder are less likely to be married or in a cohabiting relationship. This report extends previous research by investigating whether unmarried, non-cohabiting African Americans with depression are also less likely to be involved in a romantic relationship. Data are from the African American sub-sample (n=3570) of the National Survey of American Life (NSAL; 2001-2003). The DSM-IV World Mental Health Composite International Diagnostic Interview was used to assess 12-month and lifetime MDD. Weighted logistic regression was used. The findings indicate that for both 12-month and lifetime major depressive disorder, African Americans who are depressed are not only less likely to be married; they are also significantly less likely to be involved in a romantic relationship. This is particularly the case for 12-month depression. Due to limitations in the number of cohabiting respondents, currently married and cohabiting respondents were combined into a single category. The findings of this brief report highlight the importance of changes in marital and relationship circumstances of the U.S. population for research and practice on depression and other psychiatric disorders. Our study provides evidence for a more nuanced approach in which examining marital and romantic relationship status together promotes a better understanding of the impact of major depression on romantic unions. Copyright © 2012 Elsevier B.V. All rights reserved.

Traitement chirurgical des métastases osseuses rachidiennes

PubMed Central

Saqui, Abderrazzak El; Aggouri, Mohamed; Benzagmout, Mohamed; Chakour, Khalid; Chaoui, Mohamed El Faiz

2017-01-01

La chirurgie de la métastase est une chirurgie palliative le plus souvent, surtout au niveau du rachis de par sa localisation anatomique. Cette chirurgie doit être bien préparée pour que les suites soient simples et que le traitement adjuvant soit fait dans les meilleurs délais. La stratégie thérapeutique doit être systématiquement prise en réunion de concertation pluridisciplinaire (RCP). Le principal risque de la localisation rachidienne est neurologique, c'est pourquoi cette chirurgie doit être préventive le plus souvent. Elle a pour objectif principal d'améliorer la qualité de vie. PMID:28533876

Phytosynthesized gold nanoparticles from C. roxburghii DC. leaf and their toxic effects on normal and cancer cell lines.

PubMed

Balashanmugam, Pannerselvam; Durai, Prabhu; Balakumaran, Manickam Dakshinamoorthi; Kalaichelvan, Pudupalayam Thangavelu

2016-12-01

Gold nanoparticles are considered of great importance compared to other noble metal nanoparticles and its wide range of applications like pharmaceutics, therapeutics and diagnostics etc. During the past decade, phytosynthesized gold nanoparticles (AuNPs) are more focused in in vitro and in vivo study. The present study was focused on the gold chloride and phytosynthesized gold nanoparticles from aqueous leaf extract of Cassia roxburghii and their toxic effects on African green monkey normal kidney Vero cell line and three different cancer cell lines such as HepG2, MCF7 and HeLa. Phytosynthesized AuNPs were characterized by HRTEM, EDX, XRD and FTIR analysis. The particles size range of 25-35nm was confirmed by HRTEM. The elemental gold and the crystalline nature of AuNPs were confirmed by EDX and XRD, respectively. The reduction of functional groups was confirmed by FTIR. In in vitro study, the IC 50 of HepG2 cells was found to be 30μg/ml compared to other cell lines, HeLa and MCF7 cell line showing IC 50 of 50μg/ml and normal Vero cell line also nontoxic up to 75μg/ml confirmed by MTT assay. Further, apoptosis in HepG2 was analyzed by fluorescence microscope and DNA fragmentation was observed in HepG2 treated cells. These results suggested that phytosynthesized AuNPs of C. roxburghii extract clearly limited toxic on normal cells but toxic in cancer cells. Copyright © 2016 Elsevier B.V. All rights reserved.

Players' and coaches' knowledge and awareness of the BokSmart Safe Six injury prevention programme: an ecological cross-sectional questionnaire study.

PubMed

Sewry, Nicola; Verhagen, Evert; Lambert, Mike; van Mechelen, Willem; Brown, James

2017-11-03

Rugby has a high injury incidence and therefore BokSmart introduced the Safe Six injury prevention programme in 2014 in an attempt to decrease this incidence. In 2015, BokSmart used a 'targeted marketing approach' to increase the awareness and knowledge of the Safe Six . Therefore, the aim of this study was to determine the change in the knowledge of coaches and players of the Safe Six programme, compared with the launch year, following a 'targeted marketing approach'. Ecological cross-sectional questionnaire study SETTING: The 2014-2016 South African rugby union youth week tournaments. Questionnaires were completed by 4502 players and coaches who attended any of the four youth week tournaments during 2014-2016. Logistic regression (adjusted OR, 95% CI) was performed in comparison to year prior to targeted marketing, separately for coaches and players, for changes in awareness and knowledge. The awareness of the Safe Six increased significantly for players in 2015 (1.74 times (95% CI 1.49 to 2.04)) and in 2016 (1.54 times (95% CI 1.29 to 1.84)). Similarly for coaches, there was a 3.55 times (95% CI 1.23 to 9.99) increase in 2015 and a 10.11 times (95% CI 2.43 to 42.08) increase in 2016 compared with 2014. Furthermore, a player was significantly more likely to be aware of the Safe Six if his coach was aware of the programme (p<0.05). The knowledge and awareness of the BokSmart Safe Six of both players and coaches increased in 2015 and 2016 (compared with 2014) since the launch of the programme. Coaches, the Unions/the South African Rugby Union and social media were the largest contributors to knowledge in coaches and players. While the 'targeted marketing approach' was associated with an increase in awareness, future studies should determine if this translates into behavioural change. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[The tobacco problem in French-speaking Africa and regional perspectives of the French-speaking African tobacco observatory].

PubMed

Cherif, Mokhtar Hamdi

2005-01-01

The tobacco problem is one which is both global and political. The epidemic and the growing smoking crisis in Africa is a menace to the health of our continent, with significant socio-economic repercussions to follow in the coming years. Approximately 1.1 billion people around the world smoke, and between now and the year 2025, this number will most likely increase to 1.6 billion. By 2030, 10 million tobacco-related deaths will have occurred, and for the most part those deaths will be concentrated in developing countries. The tobacco industry clearly lies at the heart of the development of the tobacco pandemic in the 20th century. Specifically, cigarettes have made tobacco a massively consumed product, constantly expanding and opening up new markets; the day before yesterday it was men, yesterday it was women and youth, and today it is the developing world. The strategy is identical: increase sales, and do goat a price which puts a heavy burden on the population's health. The industries turn themselves towards developing countries, and namely Africa, in order to compensate for their losses in the markets of the Northern Hemisphere at a time when the demand in these countries is decreasing. The industry's cynical strategy targets Africa as its strongest potential market for development, counting on an estimated increase in consumption of 16% over the next decade, according to WHO's recent World Tobacco Atlas. The illegal importation of cigarettes is a practice which is growing more and more within African countries, with a well-structured African network for smuggling. Smuggled cigarettes are even more toxic with very elevated levels of nicotine and tar. Sponsorship as well as direct and indirect advertising are rapidly developing in all kinds of formats, with a proliferation of aggressive advertising messages targeting African populations with cynicism, manipulation, the complicity of smuggling in broad daylight, and disrespect for the law, while exploiting all of the themes which promote tobacco use to the target audiences (youth, women, the poorest groups). Everyday the tobacco industry recruits new African smokers to replace those who die. The future of the industry is represented by about 8 out of 10 people who began smoking before the age of 18 years old. It was imperative to establish a Tobacco Observatory in Francophone Africa (OTAF) in order to resituate the African tobacco situation, contribute to the development of the French-speaking nations in Africa, and to make known and increase awareness of its needs, its initiatives, and its actions across the world, and finally to effectively fight against tobacco and the industry's practices. One year after OTAF was established in Bamako thanks to the consolidated efforts of all its members and support of the French League against Cancer and the International Union against Cancer, OTAF OTAF is an independent entity whose mission is to gather, analyse and disseminate information on all aspects of tobacco with the objective of soliciting and supporting public health activities and interventions. It is a reference centre for Francophone Africa and a technical advisory group for the public authorities on tobacco issues. OTAF's work is counted upon to inform the public authorities on the most effective measures to use in the fight against tobacco. OTAF's duty is to promote activities which protect the health of young people and non-smokers, and communicate on the harmful effects of tobacco and the tobacco industry's practices. The goal is to organise a fight against tobacco based on solid, scientific data of the highest level of quality. OTAF is the only Francophone African surveillance organisation for monitoring the tobacco epidemic, and the practices, schemes and methods of the tobacco industry which are known to be dishonest Today, OTAF is a unique reference centre as far as the fight against tobacco is concerned in Francophone Africa. It is a partner in a number of projects with the French League against Cancer, the International Union against Cancer, and the International Union for Health Promotion and Education, among others. The success of OTAF has been crowned by a trophee having been awarded by WHO and an honorary degree signed by WHO's Director General.

New insights on multiplicity and clustering in Taurus.

NASA Astrophysics Data System (ADS)

Joncour, Isabelle; Duchene, Gaspard; Moraux, Estelle; Mundy, Lee

2018-01-01

Multiplicity and clustering of young stars are critical clues to constraint star formation process. The Taurus molecular complex is the archetype of a quiescent star forming region that may retain primeval signature of star formation.Using statistical and clustering tools such as nearest neighbor statistics, correlation functions and the density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm, this work reveals new spatial substructures in Taurus.We have identified unexpected ultra wide pairs (UWPs) candidates of high order multiplicity in Taurus in the 5-60 kAU separation range (Joncour et al 2017), beyond the separation assessed for wide pairs (Kraus & Hillenbrand 2009).Our work reveals 20 local stellar substructures, the Nested Elementary Structures (NESTs). These NESTs contain nearly half the stars of Taurus and 75% of the Class 0/I objects probing that they are the preferred sites of star formation (Joncour et al, sub.). The NESTs size ranges from few kAU up to 80 kAU making a length scale bridge between wide pairs and loose group (few hundreds kAU, Kirk & Myers, 2011). The NESTs mass ranges from 0.5-10 solar mass. The balance between Class I, II and III in NESTs suggests that they may be ordered as an evolutionary temporal scheme, some of them got infertile, while other shelter stars in infancy.The UWPs and the NESTs may be pristine imprints of their spatial configuration at birth. The UWPs population may result from a cascade fragmentation scenario of the natal molecular core. They could be the older counterparts, to the 0.5 Myr prestellar cores/Class 0 multiple objects observed at radio/millimeter wavelengths (Tobin et al 2010, 2016) and the precursors of the large number of UWPs (10–100 kAU) recently identified in older moving groups (Floriano-Alonso et al, 2015 ; Elliot et al 2016). The NESTs may result from the gravitational collapse of a gas clump that fragments to give a tight collection of stars within few millions years.This project has been partly supported by the StarFormMapper project funded by the European Union's Horizon 2020 Research and Innovation Action (RIA) program under grant agreement number 687528.

Healthy lifestyle intervention for African American uterine cancer survivors: Study protocol.

PubMed

Stewart, Jessica Lynn; Besenyi, Gina B; Williams, Lovoria B; Burt, Victoria; Anglin, Judith C; Ghamande, Sharad A; Coughlin, Steven Scott

2017-12-01

Cancer of the uterine corpus is the most common gynecologic malignancy and the fourth most common cancer in U.S. women. There is a racial disparity in the survival from endometrial cancer and this may be addressed by culturally-tailored lifestyle interventions to help African American (AA) endometrial cancer survivors lose weight or maintain a healthy weight. The overall purpose of this pilot study is to develop and evaluate a culturally-tailored lifestyle intervention to help AA uterine cancer survivors reduce their risk of cancer recurrence and improve their quality of life through healthy eating, physical activity, and weight management. While many interventions have been evaluated to assist cancer survivors through diet and physical activity, few have focused on AA women with a uterine cancer diagnosis. Community-engaged research principles are being followed. This study was developed with input from the Augusta University (AU) College of Nursing Community Advisory Board (CAB) and the Division of Gynecologic Oncology at the Georgia Cancer Center at AU. Weekly sessions throughout a 12-week intervention will include physical activity and lectures on improving nutritional status. The pre/post-test design includes baseline and 6-month follow-up, where participants will complete a questionnaire that assesses knowledge and attitudes about physical activity, nutrition, uterine cancer, social support, and quality of life. From this pilot study, we will learn more about the feasibility and integration of healthy lifestyle interventions in this patient population, and the results can provide an opportunity for a larger-scale, multi-center study with a randomized controlled design.

eGY-Africa: addressing the digital divide for science in Africa

NASA Astrophysics Data System (ADS)

Barton, C.; Petitdidier, M.; Cottrell, L.; Fox, P.

2009-04-01

The digital divide is worse in Africa than in the rest of the world, the gap is growing, and in many sub-Saharan African countries the education and research sector suffers some of the worst deficiencies in access to the Internet. By contrast, it is widely acknowledged in policy statements from the African Union, the UN, and others that this very sector provides the key to meeting and sustaining Millenium Development Goals. Developed countries with effective cyber-capabilities wax eloquent about the equal benefits to rich and poor alike arising from the Information Revolution. This is but a dream for many (most?) scientists in African institutions; as the world of science becomes increasingly Internet-dependent, so they become increasingly isolated. eGY-Africa is a bottom-up initiative by African scientists and their collaborators to try to reduce this digital divide by a campaign of advocacy for better institutional facilities. The present status of Internet services, problems, and plans are being mapped via a combination of a survey questionnaire-based survey and direct measurement of Internet performance (the PingER Project). Information is being gathered on policy statements and initiatives aimed at reducing the Digital Divide. eGY-Africa is establishing National groups of concerned scientists and engaging with those initiatives with related goals. The expectation is that informed opinion from the scientific community at the institutional, national, and international levels can be used to influence the decision makers and donors who are in a position to deliver better capabilities.

Regional health governance: A suggested agenda for Southern African health diplomacy.

PubMed

Penfold, Erica Dale; Fourie, Pieter

2015-12-01

Regional organisations can effectively promote regional health diplomacy and governance through engagement with regional social policy. Regional bodies make decisions about health challenges in the region, for example, the Union of South American Nations (UNASUR) and the World Health Organisation South East Asia Regional Office (WHO-SEARO). The Southern African Development Community (SADC) has a limited health presence as a regional organisation and diplomatic partner in health governance. This article identifies how SADC facilitates and coordinates health policy, arguing that SADC has the potential to promote regional health diplomacy and governance through engagement with regional social policy. The article identifies the role of global health diplomacy and niche diplomacy in health governance. The role of SADC as a regional organisation and the way it functions is then explained, focusing on how SADC engages with health issues in the region. Recommendations are made as to how SADC can play a more decisive role as a regional organisation to implement South-South management of the regional social policy, health governance and health diplomacy agenda.

Extended Household Transitions, Race/Ethnicity, and Early Childhood Cognitive Outcomes*

PubMed Central

Mollborn, Stefanie; Fomby, Paula; Dennis, Jeff A.

2012-01-01

Beyond mothers’ union status transitions, other adults’ transitions into and out of the household contribute to family instability, particularly in early childhood. Using the Early Childhood Longitudinal Study-Birth Cohort (N≅8,550), this study examines associations between extended household transitions and age 2 cognitive development. A substantial minority of toddlers experiences these transitions, and their consequences vary by household member type, entry versus exit, and race/ethnicity. Extended household transitions predict lower cognitive scores for white children, but the selection of low-socioeconomic status families into extended households explains these disparities. Grandparent transitions predict significantly higher cognitive scores for African American and Latino children than whites, and some “other adult” transitions predict higher scores for Latinos than African Americans and whites. Extended household transitions’ consequences are independent of co-occurring residential moves and partner transitions. Findings suggest that studying extended household transitions is useful for understanding children’s early development, and their consequences vary by race/ethnicity. PMID:23017924

[Real-time PCR kits for the detection of the African Swine Fever virus].

PubMed

Latyshev, O E; Eliseeva, O V; Grebennikova, T V; Verkhovskiĭ, O A; Tsibezov, V V; Chernykh, O Iu; Dzhailidi, G A; Aliper, T I

2014-01-01

The results obtained using the diagnostic kit based on real-time polymerase chain reaction to detect the DNA of the African Swine Fever in the pathological material, as well as in the culture fluid, are presented. A high sensitivity and specificity for detection of the DNA in the organs and tissues of animals was shown to be useful for detection in the European Union referentiality reagent kits for DNA detection by real time PCR of ASFV. More rapid and effective method of DNA extraction using columns mini spin Quick gDNA(TM) MiniPrep was suggested and compared to the method of DNA isolation on the inorganic sorbent. High correlation of the results of the DNA detection of ASFV by real-time PCR and antigen detection results ASFV by competitive ELISA obtained with the ELISA SEROTEST/INGEZIM COMRAC PPA was demonstrated. The kit can be used in the veterinary services for effective monitoring of ASFV to contain, eliminate and prevent further spread of the disease.

Development and inter-laboratory validation study of an improved new real-time PCR assay with internal control for detection and laboratory diagnosis of African swine fever virus.

PubMed

Tignon, Marylène; Gallardo, Carmina; Iscaro, Carmen; Hutet, Evelyne; Van der Stede, Yves; Kolbasov, Denis; De Mia, Gian Mario; Le Potier, Marie-Frédérique; Bishop, Richard P; Arias, Marisa; Koenen, Frank

2011-12-01

A real-time polymerase chain reaction (PCR) assay for the rapid detection of African swine fever virus (ASFV), multiplexed for simultaneous detection of swine beta-actin as an endogenous control, has been developed and validated by four National Reference Laboratories of the European Union for African swine fever (ASF) including the European Union Reference Laboratory. Primers and a TaqMan(®) probe specific for ASFV were selected from conserved regions of the p72 gene. The limit of detection of the new real-time PCR assay is 5.7-57 copies of the ASFV genome. High accuracy, reproducibility and robustness of the PCR assay (CV ranging from 0.7 to 5.4%) were demonstrated both within and between laboratories using different real-time PCR equipments. The specificity of virus detection was validated using a panel of 44 isolates collected over many years in various geographical locations in Europe, Africa and America, including recent isolates from the Caucasus region, Sardinia, East and West Africa. Compared to the OIE-prescribed conventional and real-time PCR assays, the sensitivity of the new assay with internal control was improved, as demonstrated by testing 281 field samples collected in recent outbreaks and surveillance areas in Europe and Africa (170 samples) together with samples obtained through experimental infections (111 samples). This is particularly evident in the early days following experimental infection and during the course of the disease in pigs sub-clinically infected with strains of low virulence (from 35 up to 70dpi). The specificity of the assay was also confirmed on 150 samples from uninfected pigs and wild boar from ASF-free areas. Measured on the total of 431 tested samples, the positive deviation of the new assay reaches 21% or 26% compared to PCR and real-time PCR methods recommended by OIE. This improved and rigorously validated real-time PCR assay with internal control will provide a rapid, sensitive and reliable molecular tool for ASFV detection in pigs in newly infected areas, control in endemic areas and surveillance in ASF-free areas. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of climate model aerosol seasonal and spatial variability over Africa using AERONET

NASA Astrophysics Data System (ADS)

Horowitz, Hannah M.; Garland, Rebecca M.; Thatcher, Marcus; Landman, Willem A.; Dedekind, Zane; van der Merwe, Jacobus; Engelbrecht, Francois A.

2017-11-01

The sensitivity of climate models to the characterization of African aerosol particles is poorly understood. Africa is a major source of dust and biomass burning aerosols and this represents an important research gap in understanding the impact of aerosols on radiative forcing of the climate system. Here we evaluate the current representation of aerosol particles in the Conformal Cubic Atmospheric Model (CCAM) with ground-based remote retrievals across Africa, and additionally provide an analysis of observed aerosol optical depth at 550 nm (AOD550 nm) and Ångström exponent data from 34 Aerosol Robotic Network (AERONET) sites. Analysis of the 34 long-term AERONET sites confirms the importance of dust and biomass burning emissions to the seasonal cycle and magnitude of AOD550 nm across the continent and the transport of these emissions to regions outside of the continent. In general, CCAM captures the seasonality of the AERONET data across the continent. The magnitude of modeled and observed multiyear monthly average AOD550 nm overlap within ±1 standard deviation of each other for at least 7 months at all sites except the Réunion St Denis Island site (Réunion St. Denis). The timing of modeled peak AOD550 nm in southern Africa occurs 1 month prior to the observed peak, which does not align with the timing of maximum fire counts in the region. For the western and northern African sites, it is evident that CCAM currently overestimates dust in some regions while others (e.g., the Arabian Peninsula) are better characterized. This may be due to overestimated dust lifetime, or that the characterization of the soil for these areas needs to be updated with local information. The CCAM simulated AOD550 nm for the global domain is within the spread of previously published results from CMIP5 and AeroCom experiments for black carbon, organic carbon, and sulfate aerosols. The model's performance provides confidence for using the model to estimate large-scale regional impacts of African aerosols on radiative forcing, but local feedbacks between dust aerosols and climate over northern Africa and the Mediterranean may be overestimated.

African swine fever: an epidemiological update.

PubMed

Sánchez-Vizcaíno, J M; Mur, L; Martínez-López, B

2012-03-01

African swine fever (ASF) is one of the most important swine diseases, mainly because of its significant sanitary and socioeconomic consequences. This review gives an update on the epidemiology of the disease and reviews key issues and strategies to improve control of the disease and promote its eradication. Several characteristics of ASF virus (ASFV) make its control and eradication difficult, including the absence of available vaccines, marked virus resistance in infected material and contaminated animal products, and a complex epidemiology and transmission involving tick reservoir virus interactions. The incidence of ASF has not only increased on the African continent over the last 15 years, so that it now affects West African countries, Mauritius and Madagascar, but it has also reached new areas, such as the Caucasus region in 2007. In fact, the rapid spread of the disease on the European continent and the uncontrolled situation in the Russian Federation places all countries at great risk as a result of intense global trade. The proximity of some affected areas to the European Union (EU) borders (<150 km) has increased concerns about the potential economic consequences of an ASF incursion into the EU pig sector. Establishing effective surveillance, control and eradication programmes that implicate all actors (veterinarians, farmers, and policy makers) is essential for controlling ASF. African swine fever -free countries should be aware of the potential risk of ASF incursion and implement risk reduction measures such as trade controls and other sanitary measures. This review will discuss lessons learnt so far about ASF control, current challenges to its control and future studies needed to support global efforts at prevention and control. © 2012 Blackwell Verlag GmbH.

Acute health problems in African refugees: ten years' experience in a Swiss emergency department.

PubMed

Pfortmueller, Carmen A; Graf, Fabienne; Tabbara, Malek; Tabarra, Malek; Lindner, Gregor; Zimmermann, Heinz; Exadaktylos, Aristomenis K

2012-09-01

Over the last two decades, the total number of applications from Africans for asylum in the countries of the European Union has increased from 578,000 to more than 2.9 million. About 20 % (7,196/36,100) of the asylum seekers in Switzerland originate from Africa. The disease profile of African asylum seekers is remarkably different from that of the native population in the country of application. We have therefore conducted an analysis of African asylum seekers presenting themselves to our emergency department. In a retrospective analysis, the central patient registry database was searched for patients originating from Africa admitted from 1 January 2000 to 30 November 2011 and labelled as "Asylbewerber" (asylum seeker) or "Flüchtling" (refugee). Three thousand six hundred and seventy-five African asylum seekers were admitted to our emergency department between 2000 and 2010. Thirty-four percent (n = 1,247) were female and 66 % (n = 2,426) male. Eighty percent (n = 1,940) of the men and 70 % (n = 823) of the women were younger than 40 years. Most of our patients originated from Algeria (n = 612). Forty-five percent (n = 1,628) of all patients presented with internal medical problems, 40 % (n = 1,487) with injuries. 3.5 % (n = 130) of all patients presented with psychiatric problems. Admission for psychiatric problems increased steadily from 2 % (n = 4) in 2001 to 10 % (n = 35) in 2011. The causes of presentation are manifold, including internal medical problems and injuries. Admissions for psychiatric problems are increasing. Establishing simple screening scores for somatization should be a key priority in providing more focused treatment in emergency departments.

Geochemical evidence for African dust inputs to soils of western Atlantic islands: Barbados, the Bahamas, and Florida

USGS Publications Warehouse

Muhs, D.R.; Budahn, J.R.; Prospero, J.M.; Carey, S.N.

2007-01-01

We studied soils on high-purity limestones of Quaternary age on the western Atlantic Ocean islands of Barbados, the Florida Keys, and the Bahamas. Potential soil parent materials in this region, external to the carbonate substrate, include volcanic ash from the island of St. Vincent (near Barbados), volcanic ash from the islands of Dominica and St. Lucia (somewhat farther from Barbados), the fine-grained component of distal loess from the lower Mississippi River Valley, and wind-transported dust from Africa. These four parent materials can be differentiated using trace elements (Sc, Cr, Th, and Zr) and rare earth elements that have minimal mobility in the soil-forming environment. Barbados soils have compositions that indicate a complex derivation. Volcanic ash from the island of St. Vincent appears to have been the most important influence, but African dust is a significant contributor, and even Mississippi River valley loess may be a very minor contributor to Barbados soils. Soils on the Florida Keys and islands in the Bahamas appear to have developed mostly from African dust, but Mississippi River valley loess may be a significant contributor. Our results indicate that inputs of African dust are more important to the genesis of soils on islands in the western Atlantic Ocean than previously supposed. We hypothesize that African dust may also be a major contributor to soils on other islands of the Caribbean and to soils in northern South America, central America, Mexico, and the southeastern United States. Dust inputs to subtropical and tropical soils in this region increase both nutrient-holding capacity and nutrient status and thus may be critical in sustaining vegetation. Copyright 2007 by the American Geophysical Union.

SERS strategy based on the modified Au nanoparticles for highly sensitive detection of bisphenol A residues in milk.

PubMed

Yang, Libin; Chen, Yongliang; Shen, Yu; Yang, Ming; Li, Xiuling; Han, Xiaoxia; Jiang, Xin; Zhao, Bing

2018-03-01

Bisphenol A (BPA) is a highly toxic chemical, and its residue in milk product is threatening people's health due to its possible leaching from the packagings and cans with BPA coating. In this work, halides modified Au nanoparticles (NPs) as the modification substrates were first designed for rapid and sensitive determination of BPA residue in real milk by SERS method with the assistance of aggregation agents (Zn 2+ ). It can be concluded that Au NPs modification substrate with assistance of the aggregation agent can remarkably improve the detection sensitivity of BPA residue, which can significantly enhance the SERS signal of BPA and achieve the trace-level detection of BPA residue. Under the optimal conditions, the limit of detection of BPA residue can be as low as to 4.3 × 10 -9 mol/L (equal to 0.98 × 10 -3 mg/kg), which is much less than the standard of European Union (0.6mg/kg). And, there is a good linear relationship (R 2 = 0.990) between the intensity of SERS signal and the logarithm of BPA concentration in the range of 1.0 × 10 -8 -1.0 × 10 -3 mol/L. By this method, the recovery of BPA residue ranges from 89.5% to 100.2% with relative standard deviation between 4.6% and 2.7%. The proposed SERS method proves to be reliable, highly sensitive and possesses good reproducibility, which is very promising for sensitive detection of bisphenols residue in foodstuff. Copyright © 2017 Elsevier B.V. All rights reserved.

Age-Related DNA Methylation Changes and Neoplastic Transformation of the Human Prostate

DTIC Science & Technology

2009-07-01

transcriptional silencing by aberrant CpG m ethylation of C pG-rich promoter regions. 5, 6 Aberrant promoter methylation of GSTP1 , e ncoding the π-class...during prostate cancer developm ent.7 Since the recogni tion that the GSTP1 Cp G was frequently hypermethylated in prostate cancer, more than 40 genes...8 genes; SPARC, RARb2, AR, TIMP3, GSTP1 , NKX2 .5, RASSF1 A and CYP27B1 in DNA sa mples fro m African American (AA) and Caucasian (C au) m en as a

A direct comparison of popular models of normal memory loss and Alzheimer's disease in samples of African Americans, Mexican Americans, and refugees and immigrants from the former Soviet Union.

PubMed

Schrauf, Robert W; Iris, Madelyn

2011-04-01

To understand how people differentiate normal memory loss from Alzheimer's disease (AD) by investigating cultural models of these conditions. Ethnographic interviews followed by a survey. Cultural consensus analysis was used to test for the presence of group models, derive the "culturally correct" set of beliefs, and compare models of normal memory loss and AD. Chicago, Illinois. One hundred eight individuals from local neighborhoods: African Americans, Mexican Americans, and refugees and immigrants from the former Soviet Union. Participants responded to yes-or-no questions about the nature and causes of normal memory loss and AD and provided information on ethnicity, age, sex, acculturation, and experience with AD. Groups held a common model of AD as a brain-based disease reflecting irreversible cognitive decline. Higher levels of acculturation predicted greater knowledge of AD. Russian speakers favored biological over psychological models of the disease. Groups also held a common model of normal memory loss, including the important belief that "normal" forgetting involves eventual recall of the forgotten material. Popular models of memory loss and AD confirm that patients and clinicians are speaking the same "language" in their discussions of memory loss and AD. Nevertheless, the presence of coherent models of memory loss and AD, and the unequal distribution of that knowledge across groups, suggests that clinicians should include wider circles of patients' families and friends in their consultations. These results frame knowledge as distributed across social groups rather than simply the possession of individual minds. © 2011, Copyright the Authors. Journal compilation © 2011, The American Geriatrics Society.

Modular framework to assess the risk of African swine fever virus entry into the European Union.

PubMed

Mur, Lina; Martínez-López, Beatriz; Costard, Solenne; de la Torre, Ana; Jones, Bryony A; Martínez, Marta; Sánchez-Vizcaíno, Fernando; Muñoz, María Jesús; Pfeiffer, Dirk U; Sánchez-Vizcaíno, José Manuel; Wieland, Barbara

2014-07-03

The recent occurrence and spread of African swine fever (ASF) in Eastern Europe is perceived as a serious risk for the pig industry in the European Union (EU). In order to estimate the potential risk of ASF virus (ASFV) entering the EU, several pathways of introduction were previously assessed separately. The present work aimed to integrate five of these assessments (legal imports of pigs, legal imports of products, illegal imports of products, fomites associated with transport and wild boar movements) into a modular tool that facilitates the visualization and comprehension of the relative risk of ASFV introduction into the EU by each analyzed pathway. The framework's results indicate that 48% of EU countries are at relatively high risk (risk score 4 or 5 out of 5) for ASFV entry for at least one analyzed pathway. Four of these countries obtained the maximum risk score for one pathway: Bulgaria for legally imported products during the high risk period (HRP); Finland for wild boar; Slovenia and Sweden for legally imported pigs during the HRP. Distribution of risk considerably differed from one pathway to another; for some pathways, the risk was concentrated in a few countries (e.g., transport fomites), whereas other pathways incurred a high risk for 4 or 5 countries (legal pigs, illegal imports and wild boar). The modular framework, developed to estimate the risk of ASFV entry into the EU, is available in a public domain, and is a transparent, easy-to-interpret tool that can be updated and adapted if required. The model's results determine the EU countries at higher risk for each ASFV introduction route, and provide a useful basis to develop a global coordinated program to improve ASFV prevention in the EU.

Non-sanctioning of illegal tackles in South African youth community rugby.

PubMed

Brown, J C; Boucher, S J; Lambert, M; Viljoen, W; Readhead, C; Hendricks, S; Kraak, W J

2018-06-01

The tackle event in rugby union ('rugby') contributes to the majority of players' injuries. Referees can reduce this risk by sanctioning dangerous tackles. A study in elite adult rugby suggests that referees only sanction a minority of illegal tackles. The aim of this study was to assess if this finding was similar in youth community rugby. Observational study. Using EncodePro, 99 South African Rugby Union U18 Youth Week tournament matches were coded between 2011 and 2015. All tackles were coded by a researcher and an international referee to ensure that laws were interpreted correctly. The inter- and intra-rater reliabilities were 0.97-1.00. A regression analysis compared the non-sanctioned rates over time. In total, 12 216 tackles were coded, of which less than 1% (n=113) were 'illegal'. The majority of the 113 illegal tackles were front-on (75%), high tackles (72%) and occurred in the 2nd/4th quarters (29% each). Of the illegal tackles, only 59% were sanctioned. The proportions of illegal tackles and sanctioning of these illegal tackles to all tackles improved by 0.2% per year from 2011-2015 (p<0.05). In these youth community rugby players, 59% of illegal tackles were not sanctioned appropriately. This was better than a previous study in elite adult rugby, where only 7% of illegal tackles were penalised. Moreover, the rates of illegal tackles and non-sanctioned illegal tackles both improved over time. However, it is critical that referees consistently enforce all laws to enhance injury prevention efforts. Further studies should investigate the reasons for non-sanctioning. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Modular framework to assess the risk of African swine fever virus entry into the European Union

PubMed Central

2014-01-01

Background The recent occurrence and spread of African swine fever (ASF) in Eastern Europe is perceived as a serious risk for the pig industry in the European Union (EU). In order to estimate the potential risk of ASF virus (ASFV) entering the EU, several pathways of introduction were previously assessed separately. The present work aimed to integrate five of these assessments (legal imports of pigs, legal imports of products, illegal imports of products, fomites associated with transport and wild boar movements) into a modular tool that facilitates the visualization and comprehension of the relative risk of ASFV introduction into the EU by each analyzed pathway. Results The framework’s results indicate that 48% of EU countries are at relatively high risk (risk score 4 or 5 out of 5) for ASFV entry for at least one analyzed pathway. Four of these countries obtained the maximum risk score for one pathway: Bulgaria for legally imported products during the high risk period (HRP); Finland for wild boar; Slovenia and Sweden for legally imported pigs during the HRP. Distribution of risk considerably differed from one pathway to another; for some pathways, the risk was concentrated in a few countries (e.g., transport fomites), whereas other pathways incurred a high risk for 4 or 5 countries (legal pigs, illegal imports and wild boar). Conclusions The modular framework, developed to estimate the risk of ASFV entry into the EU, is available in a public domain, and is a transparent, easy-to-interpret tool that can be updated and adapted if required. The model’s results determine the EU countries at higher risk for each ASFV introduction route, and provide a useful basis to develop a global coordinated program to improve ASFV prevention in the EU. PMID:24992824

Appropriating social citizenship: women's labour, poverty, and entrepreneurship in the manual workers union of Botswana.

PubMed

Werbner, Pnina

2010-01-01

Interrogating critiques of the 'African labour aristocracy' thesis, the article proposes that public service industrial-class manual workers in Botswana form, if not a labour 'aristocracy' in the sense first defined by Saul and Arrighi, then a marginal worker 'elite'. They are privileged in having a regular salary above minimum pay, augmented by periodic lump-sum gratuity payments. This sets them apart from the other low-paid workers in the private sector, casual workers in the informal economy and a vast army of unemployed job seekers. In the absence of a national unemployment benefit scheme in Botswana, the article explores some of the strategies deployed by women members of the Manual Workers Union in their attempts to contend with the spectre of future unemployment and impoverishment. In gender terms, the article highlights the independence, autonomy and decision-making capacity of women trade unionist leaders, who straddle the worlds of workers' rights and citizens' rights, and manoeuvre their way through the maze of rules and regulations they encounter in both.

Third World adversity: African infant precocity and the role of environment.

PubMed

Saugstad, Letten F

2002-01-01

The war against illiteracy has not been won. The number of illiterates approaches a billion. Most reside in Third World countries--former colonies--where they are caught in a poverty trap of disease, low agricultural production and environmental adversity requiring technology beyond their means. I argue against the commonly held view that this is mainly attributable to the four hundred years of traffic in men. According to the late K.O. Dike, middle men along the African coast barred foreign merchants from the hinterland, and because of this the social, political structure and sovereignty of the African states remained fundamentally unchanged during the period 1400-1807, whereas a few decades after colonisation the socio-political system collapsed and was replaced by a small rich elite and many poor, while resources were taken out of Africa. Present poverty and underdevelopment represent as great a challenge as the trade in slaves. As did the African Middle-Men of that time, African leaders now must unite in an ambitious and confident Pan-African Union demonstrating strength. Western countries should focus on reducing poverty and improving nutrition. This also makes terrorism and legal and illegal migration less likely. Education is important, but the West should not limit its effort to fighting illiteracy but should also support the establishment of institutions for higher education. Africa possessed optimal conditions and an enriched environment for human evolution. African Infant Precocity is a persistent example. The human brain, like other brains, consists 60% of poly-unsaturated fatty acids (Marine-Fat), the rest being water. A sufficient amount is required to secure optimal brain growth. It normalizes brain function, and prevents sudden cardiac and infant death, which have been increasing in Western societies. Humans are unique in having a mismatch between the need for brain food--marine fat--and our common high protein diet. Nowhere is the neglect of the brain greater than in pregnancy when protein is the only major nutrient considered. Declining levels of polyunsaturated fatty acids have been observed in human milk. Deficient intake could, if not corrected, gradually impair brain function as has been seen in animal experiments.

Cladistic analysis of extant and fossil African papionins using craniodental data.

PubMed

Gilbert, Christopher C

2013-05-01

This study examines African papionin phylogenetic history through a comprehensive cladistic analysis of extant and fossil craniodental morphology using both quantitative and qualitative characters. To account for the well-documented influence of allometry on the papionin skull, the general allometric coding method was applied to characters determined to be significantly affected by allometry. Results of the analyses suggest that Parapapio, Pliopapio, and Papio izodi are stem African papionin taxa. Crown Plio-Pleistocene African papionin taxa include Gorgopithecus, Lophocebus cf. albigena, Procercocebus, Soromandrillus (new genus defined herein) quadratirostris, and, most likely, Dinopithecus. Furthermore, S. quadratirostris is a member of a clade also containing Mandrillus, Cercocebus, and Procercocebus; ?Theropithecus baringensis is strongly supported as a primitive member of the genus Theropithecus; Gorgopithecus is closely related to Papio and Lophocebus; and Theropithecus is possibly the most primitive crown African papionin taxon. Finally, character transformation analyses identify a series of morphological transformations during the course of papionin evolution. The origin of crown African papionins is diagnosed, at least in part, by the appearance of definitive and well-developed male maxillary ridges and maxillary fossae. Among crown African papionins, Papio, Lophocebus, and Gorgopithecus are further united by the most extensive development of the maxillary fossae. The Soromandrillus/Mandrillus/Cercocebus/Procercocebus clade is diagnosed by upturned nuchal crests (especially in males), widely divergent temporal lines (especially in males), medially oriented maxillary ridges in males, medially oriented inferior petrous processes, and a tendency to enlarge the premolars as an adaptation for hard-object food processing. The adaptive origins of the genus Theropithecus appear associated with a diet requiring an increase in size of the temporalis, the optimal placement of occlusal forces onto the molar battery, and an increase in the life of the posterior dentition. This shift is associated with the evolution of distinctive morphological features such as the anterior union of the temporal lines, increased enamel infoldings on the premolars and molars, a reversed curve of Spee, and delayed molar eruption. Copyright © 2013 Elsevier Ltd. All rights reserved.

Translation into French of: “Changes to publication requirements made at the XVIII International Botanical Congress in Melbourne – what does e-publication mean for you?”. Translated by Christian Feuillet and Valéry Malécot Changements des conditions requises pour la publication faits au XVIII e Congrès International de Botanique à Melbourne – qu’est-ce que la publication électronique représente pour vous?

PubMed Central

Knapp, Sandra; McNeill, John; Turland, Nicholas J.

2011-01-01

Résumé Les changements au Code International de Nomenclature Botanique sont décidés tous les 6 ans aux Sections de Nomenclature associées aux Congrès Internationaux de Botanique (CIB). Le XVIIIe CIB se tenait à Melbourne, Australie; la Section de Nomenclature s’est réunie les 18-22 juillet 2011 et ses décisions ont été acceptées par le Congrès en session plénière le 30 juillet. Suite à cette réunion, plusieurs modifications importantes ont été apportées au Code et vont affecter la publication de nouveaux noms. Deux de ces changements prendront effet le 1er janvier 2012, quelques mois avant que le Code de Melbourne soit publié. Les documents électroniques publiés en ligne en ‘Portable Document Format’ (PDF) avec un ‘International Standard Serial Number’ (ISSN) ou un ‘International Standard Book Number’ (ISBN) constitueront une publication effective, et l’exigence d’une description ou d’une diagnose en latin pour les noms des nouveaux taxa sera changée en l’exigence d’une description ou d’une diagnose en latin ou en anglais. De plus, à partir du 1er janvier 2013, les noms nouveaux des organismes traités comme champignons devront, pour que la publication soit valide, inclure dans le protologue (tous ce qui est associé au nom au moment de la publication valide) la citation d’un identifiant (‘identifier’) fourni par un dépôt reconnu (tel MycoBank). Une ébauche des nouveaux articles concernant la publication électronique est fournie et des conseils de bon usage sont esquissés. Pour encourager la diffusion des changements adoptés au Code International de Nomenclature pour les algues, les champignons et les plantes, cet article sera publié dans BMC Evolutionary Biology, Botanical Journal of the Linnean Society, Brittonia, Cladistics, MycoKeys, Mycotaxon, New Phytologist, North American Fungi, Novon, Opuscula Philolichenum, PhytoKeys, Phytoneuron, Phytotaxa, Plant Diversity and Resources, Systematic Botany et Taxon. PMID:22287925

The eNutrition Academy: Supporting a New Generation of Nutritional Scientists around the World12

PubMed Central

Geissler, Catherine; Amuna, Paul; Kattelmann, Kendra K; Zotor, Francis B; Donovan, Sharon M

2016-01-01

Nutrition training and building capacity to provide a competent workforce to support national and regional efforts to combat malnutrition remain a major challenge in Africa and other developing regions of the world. The capacity to provide the necessary intellectual drive for nutrition research, policy, and practice in countries lacking in readiness for nutrition actions is imperative to improve the health of their people. To help address this need, the eNutrition Academy (eNA) was formed as a global partnership organization by the African Nutrition Society, the Federation of African Nutrition Societies, the Nutrition Society of the United Kingdom and Ireland, the ASN, and the International Union of Nutritional Sciences, supported by Cambridge University Press. The primary objective of this partnership is to provide an online learning platform that is free to access, enabling users to benefit from a wide range of learning materials from basic tools to more-advanced learning materials for teachers and researchers in developing countries. The goal of this article was to summarize the findings of a symposium held at the ASN Scientific Sessions and Annual Meeting at Experimental Biology 2015, which explored the themes of international capacity development, with a particular focus on the African continent, online learning, and the eNA e-learning platform. Given the vast human capacity present in Africa that is poised to create new solutions to address the public health needs of the continent, now is an opportune time to establish South-North and South-South partnerships to develop the next generation of African nutritional scientists. PMID:27180382

Investing in life saving vaccines to guarantee life of future generations in Africa.

PubMed

Mihigo, R M; Okeibunor, J C; O'Malley, H; Masresha, B; Mkanda, P; Zawaira, F

2016-11-21

The World Health Organization's Regional Offices for Africa and for the Eastern Mediterranean in conjunction with the African Union and the Government of Ethiopia hosted a ministerial conference on immunization in Africa from 24 to 25 February 2016 in Addis Ababa, Ethiopia under the theme "towards universal immunization coverage as a cornerstone for health and development in Africa". The conference brought together African leaders - including health and finance ministers, and parliamentarians thus creating a powerful platform for governments to demonstrate their commitment to advancing universal access to immunization on the continent in line with the Global Vaccine Action Plan. The event also brought together advocates, technical experts, policymakers, partner agencies, donors and journalists to examine how best to drive forward immunization across Africa, ensuring every child has access to the vaccines they need. Key points highlighted throughout conference were: universal access to immunization is at the forefront of enabling Africa to reach its full potential - by improving health, driving economic growth and empowering future generations; it is one of the most cost-effective solutions in global health, with clear benefits for health and development; and immunization brings economic benefits too, reducing health care costs and increasing productivity. At the close of the conference, 46 African countries signed a historic ministerial declaration on "Universal Access to Immunization as a Cornerstone for Health and Development in Africa" signaling fierce determination among African leaders to secure the health and prosperity of their societies through immunization. Copyright © 2016 World Health Organization Regional Office for Africa. Published by Elsevier Ltd.. All rights reserved.

The eNutrition Academy: Supporting a New Generation of Nutritional Scientists around the World.

PubMed

Geissler, Catherine; Amuna, Paul; Kattelmann, Kendra K; Zotor, Francis B; Donovan, Sharon M

2016-01-01

Nutrition training and building capacity to provide a competent workforce to support national and regional efforts to combat malnutrition remain a major challenge in Africa and other developing regions of the world. The capacity to provide the necessary intellectual drive for nutrition research, policy, and practice in countries lacking in readiness for nutrition actions is imperative to improve the health of their people. To help address this need, the eNutrition Academy (eNA) was formed as a global partnership organization by the African Nutrition Society, the Federation of African Nutrition Societies, the Nutrition Society of the United Kingdom and Ireland, the ASN, and the International Union of Nutritional Sciences, supported by Cambridge University Press. The primary objective of this partnership is to provide an online learning platform that is free to access, enabling users to benefit from a wide range of learning materials from basic tools to more-advanced learning materials for teachers and researchers in developing countries. The goal of this article was to summarize the findings of a symposium held at the ASN Scientific Sessions and Annual Meeting at Experimental Biology 2015, which explored the themes of international capacity development, with a particular focus on the African continent, online learning, and the eNA e-learning platform. Given the vast human capacity present in Africa that is poised to create new solutions to address the public health needs of the continent, now is an opportune time to establish South-North and South-South partnerships to develop the next generation of African nutritional scientists.

Space and place for WHO health development dialogues in the African Region.

PubMed

Kirigia, Joses Muthuri; Nabyonga-Orem, Juliet; Dovlo, Delanyo Yao Tsidi

2016-07-18

Majority of the countries in the World Health Organization (WHO) African Region are not on track to achieve the health-related Millennium Development Goals, yet even more ambitious Sustainable Development Goals (SDGs), including SDG 3 on heath, have been adopted. This paper highlights the challenges - amplified by the recent Ebola virus disease (EVD) outbreak in West Africa - that require WHO and other partners' dialogue in support of the countries, and debate on how WHO can leverage the existing space and place to foster health development dialogues in the Region. To realise SDG 3 on ensuring healthy lives and promoting well-being for all at all ages, the African Region needs to tackle the persistent weaknesses in its health systems, systems that address the social determinants of health and national health research systems. The performance of the third item is crucial for the development and innovation of systems, products and tools for promoting, maintaining and restoring health in an equitable manner. Under its new leadership, the WHO Regional Office for Africa is transforming itself to galvanise existing partnerships, as well as forging new ones, with a view to accelerating the provision of timely and quality support to the countries in pursuit of SDG 3. WHO in the African Region engages in dialogues with various stakeholders in the process of health development. The EVD outbreak in West Africa accentuated the necessity for optimally exploiting currently available space and place for health development discourse. There is urgent need for the WHO Regional Office for Africa to fully leverage the space and place arenas of the World Health Assembly, WHO Regional Committee for Africa, African Union, Regional economic communities, Harmonization for Health in Africa, United Nations Economic Commission for Africa, African Development Bank, professional associations, and WHO African Health Forum, when it is created, for dialogues to mobilise the required resources to give the African Region the thrust it needs to attain SDG 3. The pursuit of SDG 3 amidst multiple challenges related to political leadership and governance, weak health systems, sub-optimal systems for addressing the socioeconomic determinants of health, and weak national health research systems calls for optimum use of all the space and place available for regional health development dialogues to supplement Member States' efforts.

[Eugène-Humbert Guitard, 1884-1976, initiator of the Société d' histoire de la pharmacie and founder of its bulletin].

PubMed

Julien, Pierre

2003-01-01

In 1913, the year when he publishes Deux siècles de presse au service de la pharmacie et cinquante ans de < L' Union pharmaceutique >, Guitard creates the < Société d' histoire de la pharmacie > (he is its genuine father, and not Charles Buchet) and starts its Bulletin (subsequently Revue) the editorship of which he will handle half a century. The author focuses on the striking features of his outstanding personality (acchivist, librarian, curator of a museum, expert at writing, bookseller, printer and publisher, hellenist, professor of history of pharmacy, journalist, columnist, musician, art-lover, urbanist, active defender of our cultural legacy) and the remarkable qualities of his four great works of history of pharmacy.

Assessing the impact of climate change on vector-borne viruses in the EU through the elicitation of expert opinion.

PubMed

Gale, P; Brouwer, A; Ramnial, V; Kelly, L; Kosmider, R; Fooks, A R; Snary, E L

2010-02-01

Expert opinion was elicited to undertake a qualitative risk assessment to estimate the current and future risks to the European Union (EU) from five vector-borne viruses listed by the World Organization for Animal Health. It was predicted that climate change will increase the risk of incursions of African horse sickness virus (AHSV), Crimean-Congo haemorrhagic fever virus (CCHFV) and Rift Valley fever virus (RVFV) into the EU from other parts of the world, with African swine fever virus (ASFV) and West Nile virus (WNV) being less affected. Currently the predicted risks of incursion were lowest for RVFV and highest for ASFV. Risks of incursion were considered for six routes of entry (namely vectors, livestock, meat products, wildlife, pets and people). Climate change was predicted to increase the risk of incursion from entry of vectors for all five viruses to some degree, the strongest effects being predicted for AHSV, CCHFV and WNV. This work will facilitate identification of appropriate risk management options in relation to adaptations to climate change.

Psychometric properties of the Social Problem Solving Inventory-Revised Short-Form in a South African population.

PubMed

Sorsdahl, Katherine; Stein, Dan J; Myers, Bronwyn

2017-04-01

The Social Problem Solving Inventory-Revised Short-Form (SPSI-R:SF) has been used in several countries to identify problem-solving deficits among clinical and general populations in order to guide cognitive-behavioural interventions. Yet, very few studies have evaluated its psychometric properties. Three language versions of the questionnaire were administered to a general population sample comprising 1000 participants (771 English-, 178 Afrikaans- and 101 Xhosa-speakers). Of these participants, 210 were randomly selected to establish test-retest reliability (70 in each language). Principal component analysis was performed to examine the applicability of the factor structure of the original questionnaire to the South African data. Supplementary psychometric analyses were performed, including internal consistency and test-retest reliability. Collectively, results provide initial evidence of the reliability and validity of the SPSI-R:SF for the assessment of problem solving deficits in South Africa. Further studies that explore how the Afrikaans language version of the SPSI-R:SF can be improved and that establish the predictive validity of scores on the SPSI-R:SF are needed. © 2015 International Union of Psychological Science.

HEALTH SURVEY INCLUDING SELECTED BLOOD PARAMETERS IN THE AFRICAN SLENDER SNOUTED CROCODILE (MECISTOPS CATAPHRACTUS) AT THE ABIDJAN ZOO IN CÔTE D'IVOIRE.

PubMed

Bradford, Carol; Eschenbrenner, Matt

2017-06-01

The Zoo National d'Abidjan (Abidjan Zoo) in Côte d'Ivoire, West Africa, holds the world's largest captive population of African slender-snouted crocodiles (Mecistops cataphractus, formerly Crocodylus cataphractus), at 36 adults, 16 yearlings, and 23 hatchlings. Twelve yearling and 12 adult slender-snouted crocodiles at the Abidjan Zoo were restrained for physical exam, body condition scoring, and venipuncture in September 2015. Blood samples collected from the supravertebral venous sinus were analyzed using a handheld blood analyzer (Abaxis® I-stat, Abaxis, Inc., Union City, California 94587, USA) with Chem8+ cartridges (CLIAwaived, Inc., San Diego, California 92130, USA). The adult crocodiles appeared in good general health and demonstrated blood values similar to those of other reptiles. The yearlings had low, ionized calcium values and low hematocrit and hemoglobin levels compared with the adult crocodiles and to other crocodile reference ranges. These findings may dramatically improve the health of the crocodiles and help to ensure a thriving captive population of this critically endangered species.

Regional health governance: A suggested agenda for Southern African health diplomacy

PubMed Central

Penfold, Erica Dale; Fourie, Pieter

2015-01-01

Regional organisations can effectively promote regional health diplomacy and governance through engagement with regional social policy. Regional bodies make decisions about health challenges in the region, for example, the Union of South American Nations (UNASUR) and the World Health Organisation South East Asia Regional Office (WHO-SEARO). The Southern African Development Community (SADC) has a limited health presence as a regional organisation and diplomatic partner in health governance. This article identifies how SADC facilitates and coordinates health policy, arguing that SADC has the potential to promote regional health diplomacy and governance through engagement with regional social policy. The article identifies the role of global health diplomacy and niche diplomacy in health governance. The role of SADC as a regional organisation and the way it functions is then explained, focusing on how SADC engages with health issues in the region. Recommendations are made as to how SADC can play a more decisive role as a regional organisation to implement South–South management of the regional social policy, health governance and health diplomacy agenda. PMID:26635498

Does Poor Quality Schooling and/or Teacher Quality Hurt Black South African Students Enrolling for a Degree at the University of KwaZulu-Natal?

PubMed Central

2016-01-01

Abstract Wealthy schools appoint better qualified teachers, less wealthy schools under qualified teachers. Added to this mix is a powerful teacher’s union whose policies attempt to entrench the job security of teachers in the less wealthy schools irrespective of whether they can teach their subjects or not. Can one isolate these effects from that of other socio-demographic factors that may also be affecting the performance of students when they enrol for a degree at the University of KwaZulu-Natal (UKZN)? An outcome variable that subtracts the number of courses that have been failed from the number of courses that have been passed, dividing this by the total number of years that they have spent studying for a particular degree will be used as a response variable for this paper. Objectives The system of secondary education in South Africa is highly polarized. On the one hand, we have a group of mainly Black African students, forming about 80% of the total student population, that come from a vastly under-resourced rural or township based community. On the other hand, we have a group of predominantly White and Indian students who are able to attend a far better resourced set of private schools. Added to this mix, we have 240,000 of South Africa’s total number of 390,000 primary and secondary school teachers who belong to a powerful teacher’s union which enjoys a strong political alliance with the ruling party in South Africa. With most of their union members teaching in the less wealthy schools in South Africa, `school background’ now includes a politically motivated component that focuses on teacher self–interest rather than the education of the child. What sort of effect does school background have on the performance of students when they enter an institution of higher learning? More importantly, can one isolate the effect of school background from that of other possibly confounding factors such as gender, financial aid and the receipt of some form of residence based accommodation that will also impact on their performance while at university? Method A total of 6,183 students enrolling for a degree at the University of KwaZulu-Natal (UKZN) over the period 2008 to 2012 were used a dataset for this study. Permission to use this dataset was given by the Teaching and Learning Office at UKZN. The database that was used for this study was obtained from the Division of Management Information (DMI) office at UKZN. The percentage based marks that students have managed to record for Mathematics, English, Biology and Accounting in their school leaving exams together with some other important but observable socio-economic factors were included in a regression model to determine how students will perform at UKZN. Socio-economic variables relating to gender, race and whether they have receivd some form of financial aid or residence based accommodation while studying at university were also included as predictor variables in our regression based model structure. Results and Conclusions An interaction effect associated with being a Black African student who has been privileged enough to attend a quintile five school was found to be significant. A main effect associated with being able to attend a more privileged quintile 5 school however was found to be nonsignificant even after an adjustment has been made for gender, race, the receipt of some form of financial aid and residence based accommodation. Given that UKZN already has a number of bridging programs in place that target students who have come from a less privileged background, for university based policymakers, this result may help to justify the targeted selection of Black African students from the less privileged schools that is taking place. Because some of the disparity in matric performance that we are observing may also be associated with teacher competency and the protective influence of a powerful teacher’s union, this paper may also help to highlight some of the economic costs related with having under-prepared students. “A mind is a terrible thing to waste”–United Negro College Fund. PMID:27070652

Does Poor Quality Schooling and/or Teacher Quality Hurt Black South African Students Enrolling for a Degree at the University of KwaZulu-Natal?

PubMed

Murray, Mike

2016-01-01

Wealthy schools appoint better qualified teachers, less wealthy schools under qualified teachers. Added to this mix is a powerful teacher's union whose policies attempt to entrench the job security of teachers in the less wealthy schools irrespective of whether they can teach their subjects or not. Can one isolate these effects from that of other socio-demographic factors that may also be affecting the performance of students when they enrol for a degree at the University of KwaZulu-Natal (UKZN)? An outcome variable that subtracts the number of courses that have been failed from the number of courses that have been passed, dividing this by the total number of years that they have spent studying for a particular degree will be used as a response variable for this paper. The system of secondary education in South Africa is highly polarized. On the one hand, we have a group of mainly Black African students, forming about 80% of the total student population, that come from a vastly under-resourced rural or township based community. On the other hand, we have a group of predominantly White and Indian students who are able to attend a far better resourced set of private schools. Added to this mix, we have 240,000 of South Africa's total number of 390,000 primary and secondary school teachers who belong to a powerful teacher's union which enjoys a strong political alliance with the ruling party in South Africa. With most of their union members teaching in the less wealthy schools in South Africa, `school background' now includes a politically motivated component that focuses on teacher self-interest rather than the education of the child. What sort of effect does school background have on the performance of students when they enter an institution of higher learning? More importantly, can one isolate the effect of school background from that of other possibly confounding factors such as gender, financial aid and the receipt of some form of residence based accommodation that will also impact on their performance while at university? A total of 6,183 students enrolling for a degree at the University of KwaZulu-Natal (UKZN) over the period 2008 to 2012 were used a dataset for this study. Permission to use this dataset was given by the Teaching and Learning Office at UKZN. The database that was used for this study was obtained from the Division of Management Information (DMI) office at UKZN. The percentage based marks that students have managed to record for Mathematics, English, Biology and Accounting in their school leaving exams together with some other important but observable socio-economic factors were included in a regression model to determine how students will perform at UKZN. Socio-economic variables relating to gender, race and whether they have receivd some form of financial aid or residence based accommodation while studying at university were also included as predictor variables in our regression based model structure. An interaction effect associated with being a Black African student who has been privileged enough to attend a quintile five school was found to be significant. A main effect associated with being able to attend a more privileged quintile 5 school however was found to be nonsignificant even after an adjustment has been made for gender, race, the receipt of some form of financial aid and residence based accommodation. Given that UKZN already has a number of bridging programs in place that target students who have come from a less privileged background, for university based policymakers, this result may help to justify the targeted selection of Black African students from the less privileged schools that is taking place. Because some of the disparity in matric performance that we are observing may also be associated with teacher competency and the protective influence of a powerful teacher's union, this paper may also help to highlight some of the economic costs related with having under-prepared students. "A mind is a terrible thing to waste"--United Negro College Fund.

Genetic diversity and differentiation among insular honey bee populations in the southwest Indian Ocean likely reflect old geographical isolation and modern introductions.

PubMed

Techer, Maéva Angélique; Clémencet, Johanna; Simiand, Christophe; Turpin, Patrick; Garnery, Lionel; Reynaud, Bernard; Delatte, Hélène

2017-01-01

With globalization the Western honey bee has become a nearly cosmopolitan species, but it was originally restricted to the Old World. This renowned model of biodiversity has diverged into five evolutionary lineages and several geographic "subspecies." If Apis mellifera unicolor is indubitably an African subspecies endemic to Madagascar, its relationship with honey bees from three archipelagos in the southwest Indian Ocean (SWIO) hotspot of biodiversity is misunderstood. We compared recent mtDNA diversity data to an original characterization of the nuclear diversity from honey bees in the Mascarenes and Comoros archipelagos, using 14 microsatellites, but also additional mtDNA tRNALeu-cox2 analysis. Our sampling offers the most comprehensive dataset for the SWIO populations with a total of 3,270 colonies from 10 islands compared with 855 samples from Madagascar, 113 from Africa, and 138 from Europe. Comprehensive mitochondrial screening confirmed that honey bees from La Réunion, Mauritius, and Comoros archipelagos are mainly of African origin (88.1% out of 2,746 colonies) and that coexistence with European lineages occurs only in the Mascarenes. PCA, Bayesian, and genetic differentiation analysis showed that African colonies are not significantly distinct on each island, but have diversified among islands and archipelagos. FST levels progressively decreased in significance from European and African continental populations, to SWIO insular and continental populations, and finally among islands from the same archipelago. Among African populations, Madagascar shared a nuclear background with and was most closely related to SWIO island populations (except Rodrigues). Only Mauritius Island presented clear cytoplasmic disequilibrium and genetic structure characteristic of an admixed population undergoing hybridization, in this case, between A. m. unicolor and A. m. ligustica, A. m. carnica and A. m. mellifera-like individuals. Finally, global genetic clustering analysis helped to better depict the colonization and introduction pattern of honey bee populations in these archipelagos.

Genetic diversity and differentiation among insular honey bee populations in the southwest Indian Ocean likely reflect old geographical isolation and modern introductions

PubMed Central

Clémencet, Johanna; Simiand, Christophe; Turpin, Patrick; Garnery, Lionel; Reynaud, Bernard; Delatte, Hélène

2017-01-01

With globalization the Western honey bee has become a nearly cosmopolitan species, but it was originally restricted to the Old World. This renowned model of biodiversity has diverged into five evolutionary lineages and several geographic “subspecies.” If Apis mellifera unicolor is indubitably an African subspecies endemic to Madagascar, its relationship with honey bees from three archipelagos in the southwest Indian Ocean (SWIO) hotspot of biodiversity is misunderstood. We compared recent mtDNA diversity data to an original characterization of the nuclear diversity from honey bees in the Mascarenes and Comoros archipelagos, using 14 microsatellites, but also additional mtDNA tRNALeu-cox2 analysis. Our sampling offers the most comprehensive dataset for the SWIO populations with a total of 3,270 colonies from 10 islands compared with 855 samples from Madagascar, 113 from Africa, and 138 from Europe. Comprehensive mitochondrial screening confirmed that honey bees from La Réunion, Mauritius, and Comoros archipelagos are mainly of African origin (88.1% out of 2,746 colonies) and that coexistence with European lineages occurs only in the Mascarenes. PCA, Bayesian, and genetic differentiation analysis showed that African colonies are not significantly distinct on each island, but have diversified among islands and archipelagos. FST levels progressively decreased in significance from European and African continental populations, to SWIO insular and continental populations, and finally among islands from the same archipelago. Among African populations, Madagascar shared a nuclear background with and was most closely related to SWIO island populations (except Rodrigues). Only Mauritius Island presented clear cytoplasmic disequilibrium and genetic structure characteristic of an admixed population undergoing hybridization, in this case, between A. m. unicolor and A. m. ligustica, A. m. carnica and A. m. mellifera-like individuals. Finally, global genetic clustering analysis helped to better depict the colonization and introduction pattern of honey bee populations in these archipelagos. PMID:29281653

Characterization of dissolved organic matter in a coral reef ecosystem subjected to anthropogenic pressures (La Réunion Island, Indian Ocean) using multi-dimensional fluorescence spectroscopy.

PubMed

Tedetti, Marc; Cuet, Pascale; Guigue, Catherine; Goutx, Madeleine

2011-05-01

La Saline fringing reef is the most important coral reef complex of La Réunion Island (southwestern Indian Ocean; 21°07'S, 55°32'E). This ecosystem is subjected to anthropogenic pressures through river inputs and submarine groundwater discharge (SGD). The goal of this study was to characterize the pool of fluorescent dissolved organic matter (FDOM) in different water bodies of La Saline fringing reef ecosystem using excitation-emission matrix (EEM) spectrofluorometry. From EEMs, we identified the different fluorophores by the peak picking technique and determined two fluorescence indices issued from the literature: the humification index (HIX) and the biological index (BIX). The main known fluorophores were present within the sample set: humic-like A, humic-like C, marine humic-like M, tryptophan-like T1 and T2, and tyrosine-like B1 and B2. In some samples, unknown fluorophores ("U") were also detected. The surface oceanic waters located beyond the reef front displayed a typical oligotrophic marine signature, with a dominance of autochthonous/biological material (presence of peaks: T1>B1>A>T2>M>C; HIX: 0.9±0.4; BIX: 2.3±1.1). In the reef waters, the autochthonous/biological fingerprint also dominated even though the content in humic substances was higher (same relative distribution of peaks; HIX: 1.6±0.6; BIX: 1.0±0.1). Sedimentary and volcanic SGD showed very different patterns with a strong terrestrial source for the former (A>T1>C>B1 and A>C>B1; HIX: 9.8±2.0; BIX: 0.8±0.0) and a weak terrestrial source for the latter (A>B1>U3>B2>C and A>U4>C; HIX: 2.4±0.3; BIX: 0.9±0.0). In the Hermitage River, both humic substances and protein-like material were abundant (T1>A>U5>B1>C>B2; HIX: 2.3; BIX: 1.4). We provide evidences for the presence of anthropogenic DOM in some of these water bodies. Some oceanic samples (presence of peaks U1 and U2) were likely contaminated by oil-derived PAHs from ships navigating around the reef front, whereas the Hermitage River was highly impacted by sewage effluents, numerous in this coastal area of La Réunion Island. We conclude that multi-dimensional fluorescence spectroscopy (EEM) coupled to the determination of HIX and BIX is a good tool for assessing the origin and distribution of DOM in the coral reef ecosystems submitted to anthropogenic impacts. Copyright © 2011 Elsevier B.V. All rights reserved.

RHUM-RUM investigates La Réunion mantle plume from crust to core

NASA Astrophysics Data System (ADS)

Sigloch, Karin; Barruol, Guilhem

2013-04-01

RHUM-RUM (Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel) is a French-German passive seismic experiment designed to image an oceanic mantle plume - or lack of plume - from crust to core beneath La Réunion Island, and to understand these results in terms of material, heat flow and plume dynamics. La Réunion hotspot is one of the most active volcanoes in the world, and its hotspot track leads unambiguously to the Deccan Traps of India, one of the largest flood basalt provinces on Earth, which erupted 65 Ma ago. The genesis and the origin at depth of the mantle upwelling and of the hotspot are still very controversial. In the RHUM-RUM project, 57 German and French ocean-bottom seismometers (OBS) are deployed over an area of 2000 km x 2000 km2 centered on La Réunion Island, using the "Marion Dufresne" and "Meteor" vessels. The one-year OBS deployment (Oct. 2012 - Oct. 2013) will be augmented by terrestrial deployments in the Iles Eparses in the Mozambique Channel, in Madagascar, Seychelles, Mauritius, Rodrigues and La Réunion islands. A significant number of OBS will be also distributed along the Central and South West Indian Ridges to image the lower-mantle beneath the hotspot, but also to provide independent opportunity for the study of these slow to ultra-slow ridges and of possible plume-ridge interactions. RHUM-RUM aims to characterize the vertically ascending flow in the plume conduit, as well as any lateral flow spreading into the asthenosphere beneath the western Indian Ocean. We want to establish the origin of the heat source that has been fueling this powerful hotspot, by answering the following questions: Is there a direct, isolated conduit into the deepest mantle, which sources its heat and material from the core-mantle boundary? Is there a plume connection to the African superswell at mid-mantle depths? Might the volcanism reflect merely an upper mantle instability? RHUM-RUM also aims at studying the hotspot's interaction with the neighboring ridges of the Indian Ocean. There is in particular a long-standing hypothesis, not yet examined seismically, that channelized plume flow beneath the aseismic Rodrigues Ridge could feed the Central Indian Ridge at 1000 km distance. The RHUM-RUM group (www.rhum-rum.net): * IPG Paris & Géosciences Réunion: G. Barruol, J.P. Montagner, E. Stutzmann, F.R. Fontaine, C. Deplus, M. Cannat, G. Roult, J. Dyment, S. Singh, W. Crawford, C. Farnetani, N. Villeneuve, L. Michon. V. Ferrazzini, Y. Capdeville. * Univ. Munich (LMU): K. Sigloch, H. Igel. AWI Bremerhaven: V. Schlindwein. Univ. Frankfurt: G. Rümpker. Univ. Münster: C. Thomas. Univ. Bonn: S. Miller. * Géosciences Montpellier: C. Tiberi, A. Tommasi, D. Arcay, C. Thoraval. * Mauritius Oceanography Institute: D. Bissessur. Univ. Antananarivo: G. Rambolamanana. SEYPEC Seychelles Petroleum: P. Samson, P. Joseph. * Other institutes: A. Davaille, M. Jegen, M. Maia, G. Nolet, D. Sauter, B. Steinberger.

RHUM-RUM investigates La Réunion mantle plume from crust to core

NASA Astrophysics Data System (ADS)

Sigloch, K.; Barruol, G.

2012-12-01

RHUM-RUM (Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel) is a French-German passive seismic experiment designed to image an oceanic mantle plume - or lack of plume - from crust to core beneath La Réunion Island, and to understand these results in terms of material, heat flow and plume dynamics. La Réunion hotspot is one of the most active volcanoes in the world, and its hotspot track leads unambiguously to the Deccan Traps of India, one of the largest flood basalt provinces on Earth, which erupted 65 Ma ago. The genesis and the origin at depth of the mantle upwelling and of the hotspot are still very controversial. In the RHUM-RUM project, 57 German and French ocean-bottom seismometers (OBS) are deployed over an area of 2000 km x 2000 km2 centered on La Réunion Island, using the "Marion Dufresne" and "Meteor" vessels. The one-year OBS deployment (Oct. 2012 - Oct. 2013) will be augmented by terrestrial deployments in the Iles Eparses in the Mozambique Channel, in Madagascar, Seychelles, Mauritius, Rodrigues and La Réunion islands. A significant number of OBS will be also distributed along the Central and South West Indian Ridges to image the lower-mantle beneath the hotspot, but also to provide independent opportunity for the study of these slow to ultra-slow ridges and of possible plume-ridge interactions. RHUM-RUM aims to characterize the vertically ascending flow in the plume conduit, as well as any lateral flow spreading into the asthenosphere beneath the western Indian Ocean. We want to establish the origin of the heat source that has been fueling this powerful hotspot, by answering the following questions: Is there a direct, isolated conduit into the deepest mantle, which sources its heat and material from the core-mantle boundary? Is there a plume connection to the African superswell at mid-mantle depths? Might the volcanism reflect merely an upper mantle instability? RHUM-RUM also aims at studying the hotspot's interaction with the neighboring ridges of the Indian Ocean. There is in particular a long-standing hypothesis, not yet examined seismically, that channelized plume flow beneath the aseismic Rodrigues Ridge could feed the Central Indian Ridge at 1000 km distance. The RHUM-RUM group (www.rhum-rum.net): * IPG Paris & Géosciences Réunion: G. Barruol, J.P. Montagner, E. Stutzmann, F.R. Fontaine, C. Deplus, M. Cannat, G. Roult, J. Dyment, S. Singh, W. Crawford, C. Farnetani, N. Villeneuve, L. Michon. V. Ferrazzini, Y. Capdeville. * Univ. Munich (LMU): K. Sigloch, H. Igel. AWI Bremerhaven: V. Schlindwein. Univ. Frankfurt: G. Rümpker. Univ. Münster: C. Thomas. Univ. Bonn: S. Miller. * Géosciences Montpellier: C. Tiberi, A. Tommasi, D. Arcay, C. Thoraval. * Mauritius Oceanography Institute: D. Bissessur. Univ. Antananarivo: G. Rambolamanana. SEYPEC Seychelles Petroleum: P. Samson, P. Joseph. * Other institutes: A. Davaille, M. Jegen, M. Maia, G. Nolet, D. Sauter, B. Steinberger.

The burden of antenatal heart disease in South Africa: a systematic review

PubMed Central

2012-01-01

Background Maternal mortality in South Africa is rising, and heart conditions currently account for 41 per cent of indirect causes of deaths. Little is known about the burden of heart disease in pregnant South Africans. Methods We systematically reviewed the contemporary epidemiology and peripartum outcomes of heart disease in South African women attending antenatal care. Searches were performed in PubMed, ISI Web of Science, the EBSCO Africa-Wide database, the South African Union Catalogue, and the Current and Completed Research database (South Africa). References of included articles were also hand-searched. Studies reporting epidemiologic data on antenatal heart disease in South Africa were included. Data on morbidity and mortality were also collected. Results Seven studies were included in the systematic review. The prevalence of heart disease ranged from 123 to 943 per 100,000 deliveries, with a median prevalence of 616 per 100,000. Rheumatic valvular lesions were the commonest abnormalities, although cardiomyopathies were disproportionately high in comparison with other developing countries. Peripartum case-fatality rates were as high as 9.5 per cent in areas with limited access to care. The most frequent complications were pulmonary oedema, thromboembolism, and major bleeding with warfarin use. Perinatal mortality ranged from 8.9 to 23.8 per cent, whilst mitral lesions were associated with low birth weight. Meta-analysis could not be performed due to clinical and statistical heterogeneity of the included studies. Conclusion Approximately 0.6 per cent of pregnant South Africans have pre-existing cardiac abnormalities, with rheumatic lesions being the commonest. Maternal and perinatal morbidity and mortality continue to be very high. We conclude this review by summarising limitations of the current literature and recommending standard reporting criteria for future reports. PMID:22463484

Action without frontiers. SADC meeting.

PubMed

Klouda, T

1997-02-01

The factors which affect AIDS and the transmission of HIV transcend national, racial, cultural, religious, political, and programmatic boundaries. The European Union and the Southern African Development Community (SADC) jointly held a conference in Lilongwe, Malawi, during December 4-6 to bring together senior officials from a wide range of development sectors in the 12 countries of the SADC region to examine the potential for regional, comprehensive action on relevant issues. Conference outcomes will be reviewed and agreed upon at a future regional ministerial meeting. Origins of the conference, innovative aspects of the conference, and regional and sectoral involvement are discussed. Employment, mining, medical drugs, education, and tourism were discussed extensively at the conference as separate sectors.

Autochthonous Crimean-Congo Hemorrhagic Fever in Spain.

PubMed

Negredo, Anabel; de la Calle-Prieto, Fernando; Palencia-Herrejón, Eduardo; Mora-Rillo, Marta; Astray-Mochales, Jenaro; Sánchez-Seco, María P; Bermejo Lopez, Esther; Menárguez, Javier; Fernández-Cruz, Ana; Sánchez-Artola, Beatriz; Keough-Delgado, Elena; Ramírez de Arellano, Eva; Lasala, Fátima; Milla, Jakob; Fraile, Jose L; Ordobás Gavín, Maria; Martinez de la Gándara, Amalia; López Perez, Lorenzo; Diaz-Diaz, Domingo; López-García, M Aurora; Delgado-Jimenez, Pilar; Martín-Quirós, Alejandro; Trigo, Elena; Figueira, Juan C; Manzanares, Jesús; Rodriguez-Baena, Elena; Garcia-Comas, Luis; Rodríguez-Fraga, Olaia; García-Arenzana, Nicolás; Fernández-Díaz, Maria V; Cornejo, Victor M; Emmerich, Petra; Schmidt-Chanasit, Jonas; Arribas, Jose R

2017-07-13

Crimean-Congo hemorrhagic fever (CCHF) is a widely distributed, viral, tickborne disease. In Europe, cases have been reported only in the southeastern part of the continent. We report two autochthonous cases in Spain. The index patient acquired the disease through a tick bite in the province of Ávila - 300 km away from the province of Cáceres, where viral RNA from ticks was amplified in 2010. The second patient was a nurse who became infected while caring for the index patient. Both were infected with the African 3 lineage of this virus. (Funded by Red de Investigación Cooperativa en Enfermedades Tropicales [RICET] and Efficient Response to Highly Dangerous and Emerging Pathogens at EU [European Union] Level [EMERGE].).

Constrains on the South Atlantic Anomaly from Réunion Island

NASA Astrophysics Data System (ADS)

Béguin, A.; de Groot, L. V.

2017-12-01

The South Atlantic Anomaly (SAA) is a region where the geomagnetic field intensity is about half as strong as would be expected from the current geomagnetic dipole moment that arises from geomagnetic field models. Those field models predict a westward movement of the SAA and predicts its origin East of Africa around 1500 AD. The onset and evolution of the SAA, however, are poorly constrained due to a lack of full-vector paleomagnetic data from Africa and the Indian Ocean for the past centuries. Here we present a full-vector paleosecular variation (PSV) curve for Réunion Island (21°S, 55°E) located East the African continent, in the region that currently shows the fastest increase in geomagnetic field strength in contrast to the average global decay. We sampled 27 sites covering the last 700 years, and subjected them to a directional and multi-method paleointensity study. The obtained directional records reveal shallower inclinations and less variation in the declination compared to current geomagnetic field model predictions. Scrutinizing the IZZI-Thellier, Multispecimen, and calibrated pseudo-Thellier results produces a coherent paleointensity record. The predicted intensity trend from the geomagnetic field models generally agrees with the trend in our data, however, the high paleointensities are higher than the models predict, and the low paleointensities are lower than the models. This illustrates the inevitable smoothing inherent to geomagnetic field modelling. We will discuss the constraints on the onset of the SAA that arise from the new full-vector PSV curve for Réunion that we present and the implications for the past and future evolution of this geomagnetic phenomenon.

Assessment of African Swine Fever Diagnostic Techniques as a Response to the Epidemic Outbreaks in Eastern European Union Countries: How To Improve Surveillance and Control Programs

PubMed Central

Nieto, R.; Soler, A.; Pelayo, V.; Fernández-Pinero, J.; Markowska-Daniel, I.; Pridotkas, G.; Nurmoja, I.; Granta, R.; Simón, A.; Pérez, C.; Martín, E.; Fernández-Pacheco, P.; Arias, M.

2015-01-01

This study represents a complete comparative analysis of the most widely used African swine fever (ASF) diagnostic techniques in the European Union (EU) using field and experimental samples from animals infected with genotype II ASF virus (ASFV) isolates circulating in Europe. To detect ASFV, three different PCRs were evaluated in parallel using 785 field and experimental samples. The results showed almost perfect agreement between the Universal ProbeLibrary (UPL-PCR) and the real-time (κ = 0.94 [95% confidence interval {CI}, 0.91 to 0.97]) and conventional (κ = 0.88 [95% CI, 0.83 to 0.92]) World Organisation for Animal Health (OIE)-prescribed PCRs. The UPL-PCR had greater diagnostic sensitivity for detecting survivors and allows earlier detection of the disease. Compared to the commercial antigen enzyme-linked immunosorbent assay (ELISA), good-to-moderate agreement (κ = 0.67 [95% CI, 0.58 to 0.76]) was obtained, with a sensitivity of 77.2% in the commercial test. For ASF antibody detection, five serological methods were tested, including three commercial ELISAs, the OIE-ELISA, and the confirmatory immunoperoxidase test (IPT). Greater sensitivity was obtained with the IPT than with the ELISAs, since the IPT was able to detect ASF antibodies at an earlier point in the serological response, when few antibodies are present. The analysis of the exudate tissues from dead wild boars showed that IPT might be a useful serological tool for determining whether or not animals had been exposed to virus infection, regardless of whether antibodies were present. In conclusion, the UPL-PCR in combination with the IPT was the most trustworthy method for detecting ASF during the epidemic outbreaks affecting EU countries in 2014. The use of the most appropriate diagnostic tools is critical when implementing effective control programs. PMID:26041901

Assessment of African Swine Fever Diagnostic Techniques as a Response to the Epidemic Outbreaks in Eastern European Union Countries: How To Improve Surveillance and Control Programs.

PubMed

Gallardo, C; Nieto, R; Soler, A; Pelayo, V; Fernández-Pinero, J; Markowska-Daniel, I; Pridotkas, G; Nurmoja, I; Granta, R; Simón, A; Pérez, C; Martín, E; Fernández-Pacheco, P; Arias, M

2015-08-01

This study represents a complete comparative analysis of the most widely used African swine fever (ASF) diagnostic techniques in the European Union (EU) using field and experimental samples from animals infected with genotype II ASF virus (ASFV) isolates circulating in Europe. To detect ASFV, three different PCRs were evaluated in parallel using 785 field and experimental samples. The results showed almost perfect agreement between the Universal ProbeLibrary (UPL-PCR) and the real-time (κ = 0.94 [95% confidence interval {CI}, 0.91 to 0.97]) and conventional (κ = 0.88 [95% CI, 0.83 to 0.92]) World Organisation for Animal Health (OIE)-prescribed PCRs. The UPL-PCR had greater diagnostic sensitivity for detecting survivors and allows earlier detection of the disease. Compared to the commercial antigen enzyme-linked immunosorbent assay (ELISA), good-to-moderate agreement (κ = 0.67 [95% CI, 0.58 to 0.76]) was obtained, with a sensitivity of 77.2% in the commercial test. For ASF antibody detection, five serological methods were tested, including three commercial ELISAs, the OIE-ELISA, and the confirmatory immunoperoxidase test (IPT). Greater sensitivity was obtained with the IPT than with the ELISAs, since the IPT was able to detect ASF antibodies at an earlier point in the serological response, when few antibodies are present. The analysis of the exudate tissues from dead wild boars showed that IPT might be a useful serological tool for determining whether or not animals had been exposed to virus infection, regardless of whether antibodies were present. In conclusion, the UPL-PCR in combination with the IPT was the most trustworthy method for detecting ASF during the epidemic outbreaks affecting EU countries in 2014. The use of the most appropriate diagnostic tools is critical when implementing effective control programs. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Different pattern of contamination by legacy POPs in two populations from the same geographical area but with completely different lifestyles: Canary Islands (Spain) vs. Morocco.

PubMed

Henríquez-Hernández, Luis Alberto; Luzardo, Octavio P; Arellano, José Luis Pérez; Carranza, Cristina; Sánchez, Nieves Jaén; Almeida-González, Maira; Ruiz-Suárez, Norberto; Valerón, Pilar F; Camacho, María; Zumbado, Manuel; Boada, Luis D

2016-01-15

The archipelago of the Canary Islands is one of the so-called ultra-peripheral territories of the European Union due to its geographical location away from the continent. Although the level of socioeconomic development and lifestyle of this region is comparable to that of any other of the European Union, it is just 100 km off the coast of Morocco, in the African continent. The population of the Canaries has been extensively studied with respect to their levels of POPs, and it has been described that their levels are relatively high compared to other European regions. It has been speculated with that the proximity to Africa may be associated with this level of contamination, but so far this theory has not been verified. This paper describes for the first time the levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in a sample of the population of Morocco (n = 131), which were compared with those of a similar sample of the population of permanent residents in the Canary Islands (n = 100) in order to check this hypothesis. Our results showed that Moroccans have higher median values of OCPs than the residents in the Canaries (∑ OCP = 150.2 ng/g lw vs. 83.4 ng/g lw, p = 0.0001). Regarding the PCBs, although recent studies have reported that new environmental sources of PCBs exist in several African countries (including Morocco), the plasma levels of most congeners were significantly higher in Canarians than in Moroccans, especially for the dioxin-like PCBs (median = 7.3 ng/g lw vs. 0.0 ng/g lw, p = 0.0001). The detailed analysis of our results suggests that the levels of these pollutants in the Canarian people are more influenced by their lifestyle and the previous use of these chemicals in the archipelago than by its geographical vicinity with Morocco.

Sensitive analysis of low-flow parameters using the hourly hydrological model for two mountainous basins in Japan

NASA Astrophysics Data System (ADS)

Fujimura, Kazumasa; Iseri, Yoshihiko; Kanae, Shinjiro; Murakami, Masahiro

2014-05-01

Accurate estimation of low flow can contribute to better water resources management and also lead to more reliable evaluation of climate change impacts on water resources. In the early study, the nonlinearity of low flow related to the storage in the basin was suggested by Horton (1937) as the exponential function of Q=KSN, where Q is the discharge, S is the storage, K is a constant and N is the exponent value. In the recent study by Ding (2011) showed the general storage-discharge equation of Q = KNSN. Since the constant K is defined as the fractional recession constant and symbolized as Au by Ando et al. (1983), in this study, we rewrite this equation as Qg=AuNSgN, where Qg is the groundwater runoff and Sg is the groundwater storage. Although this equation was applied to a short-term runoff event of less than 14 hours using the unit hydrograph method by Ding, it was not yet applied for a long-term runoff event including low flow more than 10 years. This study performed a sensitive analysis of two parameters of the constant Au and exponent value N by using the hourly hydrological model for two mountainous basins in Japan. The hourly hydrological model used in this study was presented by Fujimura et al. (2012), which comprise the Diskin-Nazimov infiltration model, groundwater recharge and groundwater runoff calculations, and a direct runoff component. The study basins are the Sameura Dam basin (SAME basin) (472 km2) located in the western Japan which has variability of rainfall, and the Shirakawa Dam basin (SIRA basin) (205km2) located in a region of heavy snowfall in the eastern Japan, that are different conditions of climate and geology. The period of available hourly data for the SAME basin is 20 years from 1 January 1991 to 31 December 2010, and for the SIRA basin is 10 years from 1 October 2003 to 30 September 2013. In the sensitive analysis, we prepared 19900 sets of the two parameters of Au and N, the Au value ranges from 0.0001 to 0.0100 in steps of 0.0001 and the N value ranges from 1.0 to 100.0 in steps of 0.5. The analysis was evaluated by the Average of Daily runoff Relative Error (ADRE). The results showed that the minimum value of the ADRE is 32.199% using N=100.0 and Au=0.0003 for the SAME basin, and is 38.058% using N=0.0003 and Au=70.0 for the SIRA basin. Log-log plot for optimal sets of Au and N suggested accurate simulation of low flow can be achieved when relation of Au and N are in exponential form. The equations are Au=1/{26.91N1.041} and Au=1/{34.55N1.060} for each basin, which have similar gradients, but have different intercept on the log-log graph. From this study, it is found that the optimal sets of Au and N, which obtained lower relative error in the hydrological analysis, are formulated using the exponent equation. Acknowledgements This work was supported by the Research Program on Climate Change Adaption (the RECCA Project) of the Ministry of Education, Culture, Sports, Science and Technology. References Ding, J. Y. (2011) A measure of watershed nonlinearity: interpreting a variable instantaneous unit hydrograph model on two vastly different sized watersheds. Hydrol. Earth Syst. Sci., 15, 405-423. Fujimura, K., Shiraha, K., Kanae, S. & Murakami, M. (2012) Development of the hourly hydrological model for mountainous basins using the storage function method and the Diskin-Nazimov infiltration model. In: Models - Repositories of Knowledge, IAHS Publ. 355, 338-344. Horton, R. E. (1936) Natural stream channel-storage. Trans. Am. Geophys. Union, 17, 406-415. Ando, Y., Musiake, K. & Takahasi, Y. (1983) Modelling of hydrologic processes in a small natural hillslope basin, based on the synthesis of partial hydrological relationships. Journal of Hydrology, 64, 311-337.

People in sub-Saharan Africa rate their health and health care among the lowest in the world.

PubMed

Deaton, Angus S; Tortora, Robert

2015-03-01

The health of people in sub-Saharan Africa is a major global concern. However, data are weak, and little is known about how people in the region perceive their health or their health care. We used data from the Gallup World Poll in 2012 to document sub-Saharan Africans' perceived health status, their satisfaction with health care, their contact with medical professionals, and the priority they attach to health care. In comparison to other regions of the world, sub-Saharan Africa has the lowest ratings for well-being and the lowest satisfaction with health care. It also has the second-lowest perception of personal health, after only the former Soviet Union and its Eastern European satellites. HIV prevalence is positively correlated with perceived improvements in health care in countries with high prevalence. This is consistent with an improvement in at least some health care services as a result of the largely aid-funded rollout of antiretroviral treatment. Even so, sub-Saharan Africans do not prioritize health care as a matter of policy, although donors are increasingly shifting their aid efforts in the region toward health. Project HOPE—The People-to-People Health Foundation, Inc.

African dust contribution to mean ambient PM10 across the Mediterranean Basin: A quantitative approach to investigate spatial and seasonal patterns

NASA Astrophysics Data System (ADS)

Querol, X.; Pandolfi, M.; Pey, J.; Alastuey, A.; Cusack, M.; Pérez, N.; Amato, F.; Moreno, T.; Viana, M.; Mihalopoulos, N.

2009-04-01

The aim of the present study is quantifying African dust contributions to mean PM10 levels recorded across the Mediterranean basin (2001-2008, 1995-2008 in one case) and evidencing spatial variations and seasonal trends. To this end the same methodology has been applied to a number of data sets on PM levels recorded in aerosol research monitoring sites (Montseny-EUSAAR, Spain, Finokalia-EUSAAR, Greece) and from a number of regional background (RB) monitoring sites from the Co-operative Program for Monitoring and Evaluation of the Long-Range Transmission of Air pollutants in Europe (EMEP) and regional air quality monitoring networks available from Airbase-EEA data set. Around 20 data series spread across the whole Mediterranean and bordering regions have been selected and analyzed in the present study. Once the PM data were obtained the days under the influence of African dust outbreaks were identified (using HYSPLIT, DREAM-BSC, SKIRON and NAAPS tools) for each receptor site. Subsequently, a method (Escudero et al., 2007) based on the statistical data treatment of time series of PM levels, without a need of chemical analysis, was used for the quantification of the daily African PM load during dust outbreaks at each site. Finally, PM speciation data available at MSY and FKL were used to differentiate the local/regional from the African mineral contributions across the Mediterranean Basin. Results show a clear W to E and N to S increasing gradients, both on annual PM levels and annual African dust load. In the Eastern Mediterranean the episodes are more intense and are relatively frequent in spring and summer period. However in the western side of the basin, African dust outbreaks are more frequent in summer and winter. In the N, NW and NE sides of the basin 1-2 µgPM10/m3 of mean annual dust contribution was quantified, whereas in the S, SE, SW this annual contribution ranges from 6 to 10 µgPM10/m3. The number of exceedances of the PM10 daily limit value attributable to the African dust contributions was also evaluated fro the whole Mediterranean. Comparison of the African dust annual load with PM10 speciation allowed quantifying regional dust contributions. Thus, in urban areas we are able to discriminate the contribution of African, regional, urban and road dust. References Escudero M. et al., (2007). Atmos. Environ., 41, 5516- 5524. Acknowledgements This study was supported by the Ministry of Science and Innovation (CGL2005-03428-C04-03/CLI, CGL2007-62505/CLI, GRACCIE- CSD2007-00067), the European Union (6th framework CIRCE IP, 036961, EUSAAR RII3-CT-2006-026140). Finally, we would like to express our gratitude to Airbase-EEA for allowing free access to ambient PM levels recorded at a large number of sites in Europe.

Women and stress: a community prevention and health promotion program.

PubMed

Adam, D

1989-12-01

The past few decades have witnessed the launching of many health education and promotion programs for women, including Odyssée, Nouveaux départs and Women and Stress (Stress au féminin). Women and Stress was developed jointly by the Union culturelle des Franco-ontariennes, mental health professionals and representatives of the target audience. Its purpose is to help women take charge of their own health and their own bodies. This 15-hour group program, intended for French-speaking women in Ontario, includes six workshops that identify the symptoms and sources of stress and teach effective stress management strategies. The program is original in that it was designed primarily to be delivered by non-professionals in the community. According to the results of an evaluation by 360 participants, the program was an immediate success: it attained its health education and promotion objectives, and fostered community control in the area of prevention and health promotion.

Thermosensitive nanospheres with a gold layer revealed as low-cytotoxic drug vehicles.

PubMed

Qin, Jian; Jo, Yun Suk; Ihm, Jong Eun; Kim, Do Kyung; Muhammed, Mamoun

2005-09-27

In this paper, the positive effect of a gold layer on cell viability is demonstrated by examining the results given by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfop henyl)-2H-tetrazolium (MTS) assay and two-color cell fluorescence viability (TCCV) assay. These cytotoxicity tests were performed with human cervical adenocarcinoma cells (HeLa cell line) and transformed African green monkey kidney fibroblast cells (Cos-7 cell line). To fabricate the nanostructures as drug vehicles, first, poly(l,l-lactide-co-ethylene glycol) (PLLA-PEG) and poly(N-isopropylacrylamide-co-D,D-lactide) (PNIPAAm-PDLA) were synthesized, and then two kinds of thermosensitive nanospheres comprising "shell-in-shell" structures without a gold layer (PLLA-PEG@PNIPAAm-PDLA) and with a gold layer (Au@PLLA-PEG@PNIPAAm-PDLA) were constructed by a modified double-emulsion method (MDEM). Both of them displayed a unique thermosensitive character exhibiting the lower critical solubility temperature (LCST) at 36.7 degrees C which was confirmed by UV-vis spectroscopy and differential scanning calorimetry (DSC). The release profiles of entrapped bovine serum albumin (BSA) were monitored at 22 and 37 degrees C, respectively, to reveal the thermal dependence on the release rate. In cell viability tests, both PLLA-PEG@PNIPAAm-PDLA and Au@PLLA-PEG@PNIPAAm-PDLA showed excellent cell viability, and furthermore, Au@PLLA-PEG@PNIPAAm-PDLA, particularly at high doses, exhibited more enhanced cell viability than PLLA-PEG@PNIPAAm-PDLA. This effect is mainly attributed to the gold layer which binds the protein molecules first and consequently facilitates transmembrane uptake of essential nutrients in the cell media, resulting in favorable cell proliferation.

Diet of Australopithecus afarensis from the Pliocene Hadar Formation, Ethiopia

NASA Astrophysics Data System (ADS)

Wynn, Jonathan G.; Sponheimer, Matt; Kimbel, William H.; Alemseged, Zeresenay; Reed, Kaye; Bedaso, Zelalem K.; Wilson, Jessica N.

2013-06-01

The enhanced dietary flexibility of early hominins to include consumption of C4/crassulacean acid metabolism (CAM) foods (i.e., foods derived from grasses, sedges, and succulents common in tropical savannas and deserts) likely represents a significant ecological and behavioral distinction from both extant great apes and the last common ancestor that we shared with great apes. Here, we use stable carbon isotopic data from 20 samples of Australopithecus afarensis from Hadar and Dikika, Ethiopia (>3.4-2.9 Ma) to show that this species consumed a diet with significant C4/CAM foods, differing from its putative ancestor Au. anamensis. Furthermore, there is no temporal trend in the amount of C4/CAM food consumption over the age of the samples analyzed, and the amount of C4/CAM food intake was highly variable, even within a single narrow stratigraphic interval. As such, Au. afarensis was a key participant in the C4/CAM dietary expansion by early australopiths of the middle Pliocene. The middle Pliocene expansion of the eastern African australopith diet to include savanna-based foods represents a shift to use of plant food resources that were already abundant in hominin environments for at least 1 million y and sets the stage for dietary differentiation and niche specialization by subsequent hominin taxa.

Epidemiology of hepatitis C virus and genotype distribution in immigrants crossing to Europe from North and sub-Saharan Africa.

PubMed

Daw, Mohamed A; El-Bouzedi, Abdallah; Ahmed, Mohamed O; Dau, Aghnyia A; Agnan, Mohamed M

The association between the prevalence of hepatitis C virus (HCV) and immigration is rarely studied, particularly for the immigrants crossing to the resettlement countries. Most of the published data are confined to those immigrants who were resident in European countries and rarely immigrated before they reach the final destination. Libya is a large country in North Africa with the longest coast of the Mediterranean Sea facing the European Union. It has been considered as the main transient station for African immigrants to Europe. The objectives of this study were to determine: (1) the prevalence of HCV in African immigrants gathered in Libya from different African countries on their way to Europe and (2) HCV genotype distribution in these immigrants and its correlation with different demographic factors. A total of 14 205 serum samples were collected in a 3-year period (2013-2015) from different immigrants from North and sub-Saharan Africa who resided in the African immigrant campus, Tripoli, Libya. The participants were interviewed, and relevant information was collected, including socio-demographic, ethnic, and geographic variables. Each serum sample was tested for anti-HCV antibody using ELISA. The genotypes were determined and assigned using a specific genotyping assay and correlated with demographic and potential risk factors of the recruited individuals. Of the immigrants studied, 1078 (7.6%) were positive for HCV. The prevalence of HCV infection ranged from 1.4% to 18.7%; it was higher among individuals arriving from Nile river (3.6-18.7%) of North Africa, followed by those who arrived from the West African region (2.1-14.1%), Horn of Africa (HOA, 6.8-9.9%), and Maghreb countries (1.4-2.7%). The relative risk factor attributable to gender variation was not significant (95% Cl: 0.8513-1.2381). Five genotypes were detected in 911 African immigrants. Genotypic analysis showed that the predominant HCV genotypes in this group were genotypes 4, 1, and 2 that accounted for 329 (36.1%), 326 (35.8%), and 131 (14.4%) strains, respectively, followed by genotype 3 that accounted for 87 (9.5%) strains. Genotype 5 was isolated mainly from 18 HOA (2%) and 20 West African (2.2%) individuals. The prevalence of HCV is considered high with a unique disparate distribution among African immigrants crossing to Europe. This indicated that the prevalence of HCV is high among these immigrants and thus may be reflected on the HCV prevalence in the guest countries. The broad genetic heterogeneity of HCV genotypes detected here may impact the efficacy of prevention and control efforts for HCV in both Europe and North and sub-Saharan Africa; hence, an integrated global policy of actions is needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sun-to-Earth Analysis of a Major Solar Eruption

NASA Astrophysics Data System (ADS)

Patsourakos, Spiros

During the interval of 7-10 March 2012, Earth's space environment experienced a barrage of space weather phenomena. Early during 7 March 2012, the biggest proton event of 2012 took place, while on 8 March 2012, an interplanetary shock and coronal mass ejection (CME) arrived at 1 AU. This sequence trigerred the biggest geomagnetic storm of cycle 24 so far. The solar source of these activities was a pair of homologous, eruptive X-class flares associated with two ultra-fast CMEs. The two eruptions originated from NOAA active region 11429 during the early hours of 7 March 2012 and within an hour from each other. Using satellite data from a flotilla of solar, heliospheric and magnetospheric missions and monitors, we perform a synergistic Sun-to-Earth study of various observational aspects of the event sequences. We will present an attempt to formulate a cohesive scenario which couples the eruption initiation, interplanetary propagation, and geospace consequences. Our main focus is on building a framework that starting from solar and near-Sun estimates of the magnetic and dynamic content and properties of the Earth-directed CME assess in advance the subsequent geomagnetic response expected, once the associated interplanetary CME reaches 1 AU. This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: Thales. Investing in knowledge society through the European Social Fund.

Review of Remote Sensing Needs and Applications in Africa

NASA Technical Reports Server (NTRS)

Brown, Molly E.

2007-01-01

Remote sensing data has had an important role in identifying and responding to inter-annual variations in the African environment during the past three decades. As a largely agricultural region with diverse but generally limited government capacity to acquire and distribute ground observations of rainfall, temperature and other parameters, remote sensing is sometimes the only reliable measure of crop growing conditions in Africa. Thus, developing and maintaining the technical and scientific capacity to analyze and utilize satellite remote sensing data in Africa is critical to augmenting the continent's local weather/climate observation networks as well as its agricultural and natural resource development and management. The report Review of Remote Sensing Needs and Applications in Africa' has as its central goal to recommend to the US Agency for International Development an appropriate approach to support sustainable remote sensing applications at African regional remote sensing centers. The report focuses on "RS applications" to refer to the acquisition, maintenance and archiving, dissemination, distribution, analysis, and interpretation of remote sensing data, as well as the integration of interpreted data with other spatial data products. The report focuses on three primary remote sensing centers: (1) The AGRHYMET Regional Center in Niamey, Niger, created in 1974, is a specialized institute of the Permanent Interstate Committee for Drought Control in the Sahel (CILSS), with particular specialization in science and techniques applied to agricultural development, rural development, and natural resource management. (2) The Regional Centre for Maiming of Resources for Development (RCMRD) in Nairobi, Kenya, established in 1975 under the auspices of the United Nations Economic Commission for Africa and the Organization of African Unity (now the African Union), is an intergovernmental organization, with 15 member states from eastern and southern Africa. (3) The Regional Remote Sensing Unit (RRSU) in Gaborone, Botswana, began work in June 1988 and operates under the Agriculture Information Management System (AIMS), as part of the Food, Agriculture and Natural Resources (FANR) Directorate, based at the Southern Africa Development Community (SADC) Secretariat.

Euros vs. Yuan: Comparing European and Chinese Fishing Access in West Africa

PubMed Central

Belhabib, Dyhia; Sumaila, U. Rashid; Lam, Vicky W. Y.; Zeller, Dirk; Le Billon, Philippe; Abou Kane, Elimane; Pauly, Daniel

2015-01-01

We compare the performance of European Union (EU) and Chinese fisheries access agreements with West African countries in terms of illegal and unreported fishing, economic equity, and patterns of exploitation. Bottom-up re-estimations of catch reveal that the EU (1.6 million t•year-1) and China (2.3 million t•year-1) report only 29% and 8%, respectively, of their estimated total catches (including estimated discards whenever possible) from West African countries between 2000 and 2010. EU catches are declining, while Chinese catches are increasing and are yet to reach the historic maximum level of EU catches (3 million t•year-1 on average in the 1970s-1980s). The monetary value of EU fishing agreements, correlated in theory with reported catches, is straightforward to access, in contrast to Chinese agreements. However, once quantified, the value of Chinese agreements is readily traceable within the African economy through the different projects they directly cover, in contrast to the funds disbursed [to host governments] by the EU. Overall, China provides resources equivalent to about 4% of the ex-vessel value [value at landing] of the catch taken by Chinese distant-water fleets from West African waters, while the EU pays 8%. We address the difficulties of separating fees directly related to fishing from other economic or political motivations for Chinese fees, which could introduce a bias to the present findings as this operation is not performed for EU access fees officially related to fishing. Our study reveals that the EU and China perform similarly in terms of illegal fishing, patterns of exploitation and sustainability of resource use, while under-reporting by the EU increases and that by China decreases. The EU agreements provide, in theory, room for improving scientific research, monitoring and surveillance, suggesting a better performance than for Chinese agreements, but the end-use of the EU funds are more difficult, and sometime impossible to ascertain. PMID:25793775

A prospective blood RNA signature for tuberculosis disease risk

PubMed Central

Zak, Daniel E.; Penn-Nicholson, Adam; Scriba, Thomas J.; Thompson, Ethan; Suliman, Sara; Amon, Lynn M.; Mahomed, Hassan; Erasmus, Mzwandile; Whatney, Wendy; Hussey, Gregory D.; Abrahams, Deborah; Kafaar, Fazlin; Hawkridge, Tony; Verver, Suzanne; Hughes, E. Jane; Ota, Martin; Sutherland, Jayne; Howe, Rawleigh; Dockrell, Hazel M.; Boom, W. Henry; Thiel, Bonnie; Ottenhoff, Tom H.M.; Mayanja-Kizza, Harriet; Crampin, Amelia C; Downing, Katrina; Hatherill, Mark; Valvo, Joe; Shankar, Smitha; Parida, Shreemanta K; Kaufmann, Stefan H.E.; Walzl, Gerhard; Aderem, Alan; Hanekom, Willem A.

2016-01-01

Background Identification of blood biomarkers that prospectively predict progression of Mycobacterium tuberculosis infection to tuberculosis disease may lead to interventions that impact the epidemic. Methods Healthy, M. tuberculosis infected South African adolescents were followed for 2 years; blood was collected every 6 months. A prospective signature of risk was derived from whole blood RNA-Sequencing data by comparing participants who ultimately developed active tuberculosis disease (progressors) with those who remained healthy (matched controls). After adaptation to multiplex qRT-PCR, the signature was used to predict tuberculosis disease in untouched adolescent samples and in samples from independent cohorts of South African and Gambian adult progressors and controls. The latter participants were household contacts of adults with active pulmonary tuberculosis disease. Findings Of 6,363 adolescents screened, 46 progressors and 107 matched controls were identified. A 16 gene signature of risk was identified. The signature predicted tuberculosis progression with a sensitivity of 66·1% (95% confidence interval, 63·2–68·9) and a specificity of 80·6% (79·2–82·0) in the 12 months preceding tuberculosis diagnosis. The risk signature was validated in an untouched group of adolescents (p=0·018 for RNA-Seq and p=0·0095 for qRT-PCR) and in the independent South African and Gambian cohorts (p values <0·0001 by qRT-PCR) with a sensitivity of 53·7% (42·6–64·3) and a specificity of 82·8% (76·7–86) in 12 months preceding tuberculosis. Interpretation The whole blood tuberculosis risk signature prospectively identified persons at risk of developing active tuberculosis, opening the possibility for targeted intervention to prevent the disease. Funding Bill and Melinda Gates Foundation, the National Institutes of Health, Aeras, the European Union and the South African Medical Research Council (detail at end of text). PMID:27017310

Zimbabwe.

PubMed

1988-03-01

Zimbabwe is a land-locked plateau country of 151,000 square miles, divided into 8 provinces, in Southeastern Africa, bordered by South Africa, Botswana, Zambia and Mozambique. Its population consists of 8.8 million blacks, divided between the Shona-speaking Mashona (80%) and the Sindebele-speaking Matabele (19%), 100,000 whites, 20,000 coloreds, and 10,000 Asians. Many of the blacks are Christians. More than 1/2 the whites migrated to Zimbabwe after the Second World War at a rate of about 1000 a year until the mid-1970s; since then 12,000 whites have left the country. The official language is English, and education is free. Most African children 5-19 years old attend school, and literacy is between 40% and 50%. The University of Zimbabwe is located in Harare, the capital, and there are several technical institutes and teacher-training colleges. Zimbabwe has been inhabited since the stone age, and evidence of a high indigenous civilization remains in the "Great Zimbabwe Ruins" near Masvingo. The present black population is descended from later migrations of Bantu people from central Africa. Cecil Rhodes was granted concessions for mineral rights in the area in 1888, and the territory, which administered by the British South Africa Company, was called Rhodesia. Southern Rhodesia became a self-governing entity within the British Empire in 1913. In 1953 Southern Rhodesia was joined with the British protectorates of Northern Rhodesia and Nyasaland in the Central African Federation, but this dissolved in 1963, and Northern Rhodesia and Nyasaland became independent as Zambia and Malawi in 1964. Independence was withheld from Rhodesia because Prime Minister Ian Smith refused to give Britain assurances that the country would move toward majority rule. In 1965 Smith issued a Unilateral Declaration of Independence (UDI) from the UK. In 1966 the UN Security Council imposed mandatory economic sanctions on Rhodesia. Within Rhodesia the major African nationalist groups -- the Zimbabwe African People's Union (ZAPU) and the Zimbabwe African National Union (ZANU) united into the "Patriotic Front" and began to engage in guerrilla warfare against the minority government. Finally, in 1979, Rhodesia returned briefly to colonial status, during which time a new constitution was written, implementing majority rule; the UN Security Council called off economic sanctions; and elections were held. Robert Mugabe, leader of the victorious ZANU Party, was asked to form Zimbabwe's 1st government. The British Government formally granted independence to Zimbabwe on April 18, 1980. THe new government was to consist of a President (Mr. Mugabe), elected by universal suffrage, and a bicameral parliament. Zimbabwe has followed a policy of national reconciliation at home and "active nonalignment" abroad. In 1982, Zimbabwe was chosen by the Organization of African Unity to hold one of the nonpermanent seats in the UN Security Council, and in 1986, Zimbabwe was the site of the Nonaligned Movement summit meeting, and Mr. Mugabe became chairman of that organization. The years of sanctions, guerrilla warfare, and white emigration, combined with a foreign exchange crisis (the Zimbabwe dillar = US$.60), and the drought of 1987 took their toll on the Zimbabwean economy. Gross domestic product declined between 1974 and 1979, although by 1986, it was $4.7 billion, with per capita income $275. Zimbabwe is rich in natural resources, especially coal and chrome; and industry, which accounts for 69% of the gross domestic product, was forced by the sanctions to diversify. Plentiful coal deposits make the country less dependent on imported oil for an energy source. Agriculture, which constitutes 15% of the gross domestic product, is the backbone of the economy, with corn as the largest crop and tobacco as the largest export crop; both were hurt by the 1987 drought. Another drain on the economy was the money diverted to pay for training and equipping the armed forces. (Abstract Truncated)

Potamochoerus porcus (Artiodactyla: Suidae)

USGS Publications Warehouse

Leslie, David M.; Huffman, Brent A.

2015-01-01

Potamochoerus porcus (Linnaeus, 1758) is a monotypic suid commonly known as the red river hog. It is 1 of 2 species in the genus Potamochoerus and among the smallest and most plesiomorphic (ancestral) of the 8 African suids. This is the brightest colored wild pig species and is identified by its rufous coat and white dorsal crest; spectacled black-and-white facemask; and elongated, leaf-shaped ears that end in terminally drooping tufts of hair. P. porcus lives in damp forests throughout the rainforest belt of western and central Africa; it never ranges far from thick vegetative cover, soft soils, and water. Although P. porcus is commonly harvested for subsistence and urban bushmeat markets, it is considered of “Least Concern” by the International Union for Conservation of Nature and Natural Resources.

The participatory design of a performance oriented monitoring and evaluation system in an international development environment.

PubMed

Guerra-López, Ingrid; Hicks, Karen

2015-02-01

This article illustrates the application of the impact monitoring and evaluation process for the design and development of a performance monitoring and evaluation framework in the context of human and institutional capacity development. This participative process facilitated stakeholder ownership in several areas including the design, development, and use of a new monitoring and evaluation system, as well their targeted results and accomplishments through the use of timely performance data gathered through ongoing monitoring and evaluation. The process produced a performance indicator map, a comprehensive monitoring and evaluation framework, and data collection templates to promote the development, implementation, and sustainability of the monitoring and evaluation system of a farmer's trade union in an African country. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Niassa Gold Belt, northern Mozambique - A segment of a continental-scale Pan-African gold-bearing structure?

NASA Astrophysics Data System (ADS)

Bjerkgard, T.; Stein, H. J.; Bingen, B.; Henderson, I. H. C.; Sandstad, J. S.; Moniz, A.

2009-01-01

The Niassa Gold Belt, in northernmost Mozambique, is hosted in the Txitonga Group, a Neoproterozoic rift sequence overlying Paleoproterozoic crust of the Congo-Tanzania Craton and deformed during the Pan-African Orogeny. The Txitonga Group is made up of greenschist-facies greywacke and schist and is characterized by bimodal, mainly mafic, magmatism. A zircon U-Pb age for a felsic volcanite dates deposition of the sequence at 714 ± 17 Ma. Gold is mined artisanally from alluvial deposits and primary chalcopyrite-pyrite-bearing quartz veins containing up to 19 ppm Au have been analyzed. In the Cagurué and M'Papa gold fields, dominantly N-S trending quartz veins, hosted in metagabbro and schist, are regarded as tension gashes related to regional strike-slip NE-SW-trending Pan-African shear zones. These gold deposits have been classified as mesozonal and metamorphic in origin. Re-Os isotopic data on sulfides suggest two periods of gold deposition for the Cagurué Gold Field. A coarse-crystalline pyrite-chalcopyrite assemblage yields an imprecise Pan-African age of 483 ± 72 Ma, dating deposition of the quartz veins. Remobilization of early-formed sulfides, particularly chalcopyrite, took place at 112 ± 14 Ma, during Lower Cretaceous Gondwana dispersal. The ˜483 Ma assemblage yields a chondritic initial 187Os/ 188Os ratio of 0.123 ± 0.058. This implies a juvenile source for the ore fluids, possibly involving the hosting Neoproterozoic metagabbro. The Niassa Gold Belt is situated at the eastern end of a SW-NE trending continental-scale lineament defined by the Mwembeshi Shear Zone and the southern end of a NW-SE trending lineament defined by the Rukwa Shear Zone. We offer a review of gold deposits in Zambia and Tanzania associated with these polyphase lineaments and speculate on their interrelation.

Sociodemographic, psychosocial and physical health correlates of common mental disorder symptoms among mothers in Trinidad and Tobago: Examining ethnic variations.

PubMed

Krishnakumar, Ambika; Narine, Lutchmie; Roopnarine, Jaipaul L; Logie, Carol

2016-08-22

Historical and cultural experiences have shaped the life experiences of cultural communities in Trinidad and Tobago. Using a cultural focus, the goal of this investigation was to examine ethnic variations both in the prevalence of common mental disorder (CMD) symptoms as well as in the associations between sociodemographic, psychosocial, physical health correlates and CMDs among mothers in Trinidad and Tobago. Participants included 1002 mothers (359 African-, 353 Indo- and 290 Mixed-Ethnic Trinidadian). Mean comparisons indicated similarities in the levels of depression, somatisation and anxiety across ethnic groups. The associations between physical ill health, experiences of pain and depression and between physical ill health and somatisation were stronger for Mixed-Ethnic Trinidadian than Indo-Trinidadian mothers. The relationship between early experiences of domestic violence and depression was stronger for Indo-Trinidadian than Mixed-Ethnic Trinidadian mothers. The associations between early experiences of domestic violence and depression and between experiences of pain and somatisation were stronger for African Trinidadian than Mixed-Ethnic Trinidadian mothers. Thus beyond the direct effects, mothers belonging to specific ethnic groups indicated greater or lesser vulnerabilities to CMDs depending on their exposure to specific correlates. Results have applicability for the development of culturally sensitive interventions for mothers experiencing CMDs. © 2016 International Union of Psychological Science.

Experimental Infection of Domestic Pigs with African Swine Fever Virus Lithuania 2014 Genotype II Field Isolate.

PubMed

Gallardo, C; Soler, A; Nieto, R; Cano, C; Pelayo, V; Sánchez, M A; Pridotkas, G; Fernandez-Pinero, J; Briones, V; Arias, M

2017-02-01

An experimental infection was conducted to evaluate horizontal transmission, clinical, virological and humoral response induced in domestic pigs infected with African swine fever (ASF) genotype II virus circulating in 2014 into the European Union (EU). Ten naive pigs were placed in contact with eight pigs experimentally inoculated with the Lithuanian LT14/1490 ASF virus (ASFV) responsible for the first ASF case detected in wild boar in Lithuania in January 2014. Clinical examination and rectal temperature were recorded each day. Blood sampling from every animal was carried out twice weekly. Blood samples were examined for presence of ASF virus-specific antibodies and for determining the ASFV viral load. From the obtained results, it was concluded that the Lithuanian ASFV induced an acute disease which resulted in 94, 5% mortality. The disease was easily detected by real-time PCR prior to the onset of clinical signs and 33% of the animals seroconverted. All findings were in accordance with observations previously made in domestic pigs and wild boar when infected with ASF genotype II viruses characterized by a high virulence. One in-contact pig remained asymptomatic and survived the infection. The role of such animals in virus transmission would need further investigation. © 2015 Blackwell Verlag GmbH.

Effects of deltamethrin, dimethoate, and chlorpyrifos on survival and reproduction of the collembolan Folsomia candida and the predatory mite Hypoaspis aculeifer in two African and two European soils.

PubMed

Jaabiri Kamoun, Ikram; Jegede, Olukayode O; Owojori, Olugbenga J; Bouzid, Jalel; Gargouri, Radhia; Römbke, Jörg

2018-01-01

Indiscriminate use of pesticides is rampant in most parts of Africa, but only scanty ecotoxicological data exist for the protection of soil organisms-and these data were usually obtained under temperate conditions, including the use of Organisation for Economic Co-operation and Development (OECD) standard test protocols. In order to assess the effects of 3 commonly used pesticides (deltamethrin, dimethoate, chlorpyrifos) on soil fauna in Africa, noncontaminated natural soils were collected from Nigeria and Tunisia. In addition, 2 common test soils, OECD artificial soil and European (Landwirtschaftliche Untersichungs- und Forschungsanstalt [LUFA]) 2.3 soil, were used in OECD standard reproduction tests. Two microarthropod species, the springtail Folsomia candida and the predatory mite Hypoaspis aculeifer, were exposed in these 4 soils spiked individually with the 3 insecticides. Results show that the collembolan F. candida was more sensitive than the mite H. aculeifer for all 3 insecticides. The toxicity of each insecticide in the 4 soils differed, with few exceptions, by less than an order of magnitude. However, the pattern of toxicity was not consistent, that is, the lowest toxicity was often but not always found in OECD artificial soil. Soil- and pesticide-specific patterns of toxicity to F. candida and H. aculeifer might be related to the physicochemical properties of the soils and thus the availability of the 3 pesticides. Following the rules laid down in the European Union for the registration of pesticides and using standard European exposure scenarios, neither an acute nor a chronic risk of dimethoate and chlorpyrifos can be excluded (with few exceptions) in all 4 soils. Lower risks were identified for deltamethrin. For pesticide used in Africa, an environmental risk assessment based on data gained in tests with at least 1 additional natural field soil, preferably of African origin, should be performed using the same risk assessment principles as in the European Union. Integr Environ Assess Manag 2018;14:92-104. © 2017 SETAC. © 2017 SETAC.

Risk of African swine fever introduction into the European Union through transport-associated routes: returning trucks and waste from international ships and planes.

PubMed

Mur, Lina; Martínez-López, Beatriz; Sánchez-Vizcaíno, José Manuel

2012-08-30

The uncontrolled presence of African swine fever (ASF) in Russian Federation (RF) poses a serious risk to the whole European Union (EU) pig industry. Although trade of pigs and their products is banned since the official notification in June 2007, the potential introduction of ASF virus (ASFV) may occur by other routes, which are very frequent in ASF, and more difficult to control, such as contaminated waste or infected vehicles. This study was intended to estimate the risk of ASFV introduction into the EU through three types of transport routes: returning trucks, waste from international ships and waste from international planes, which will be referred here as transport-associated routes (TAR). Since no detailed and official information was available for these routes, a semi-quantitative model based on the weighted combination of risk factors was developed to estimate the risk of ASFV introduction by TAR. Relative weights for combination of different risk factors as well as validation of the model results were obtained by an expert opinion elicitation. Model results indicate that the relative risk for ASFV introduction through TAR in most of the EU countries (16) is low, although some countries, specifically Poland and Lithuania, concentrate high levels of risk, the returning trucks route being the analyzed TAR that currently poses the highest risk for ASFV introduction into the EU. The spatial distribution of the risk of ASFV introduction varies importantly between the analyzed introduction routes. Results also highlight the need to increase the awareness and precautions for ASF prevention, particularly ensuring truck disinfection, to minimize the potential risk of entrance into the EU. This study presents the first assessment of ASF introduction into the EU through TAR. The innovative model developed here could be used in data scarce situations for estimating the relative risk associated to each EU country. This simple methodology provides a rapid and easy to interpret results on risk that may be used for a target and cost-effective allocation of resources to prevent disease introduction.

Risk of African swine fever introduction into the European Union through transport-associated routes: returning trucks and waste from international ships and planes

PubMed Central

2012-01-01

Background The uncontrolled presence of African swine fever (ASF) in Russian Federation (RF) poses a serious risk to the whole European Union (EU) pig industry. Although trade of pigs and their products is banned since the official notification in June 2007, the potential introduction of ASF virus (ASFV) may occur by other routes, which are very frequent in ASF, and more difficult to control, such as contaminated waste or infected vehicles. This study was intended to estimate the risk of ASFV introduction into the EU through three types of transport routes: returning trucks, waste from international ships and waste from international planes, which will be referred here as transport-associated routes (TAR). Since no detailed and official information was available for these routes, a semi-quantitative model based on the weighted combination of risk factors was developed to estimate the risk of ASFV introduction by TAR. Relative weights for combination of different risk factors as well as validation of the model results were obtained by an expert opinion elicitation. Results Model results indicate that the relative risk for ASFV introduction through TAR in most of the EU countries (16) is low, although some countries, specifically Poland and Lithuania, concentrate high levels of risk, the returning trucks route being the analyzed TAR that currently poses the highest risk for ASFV introduction into the EU. The spatial distribution of the risk of ASFV introduction varies importantly between the analyzed introduction routes. Results also highlight the need to increase the awareness and precautions for ASF prevention, particularly ensuring truck disinfection, to minimize the potential risk of entrance into the EU. Conclusions This study presents the first assessment of ASF introduction into the EU through TAR. The innovative model developed here could be used in data scarce situations for estimating the relative risk associated to each EU country. This simple methodology provides a rapid and easy to interpret results on risk that may be used for a target and cost-effective allocation of resources to prevent disease introduction. PMID:22935221

Relevant Measures to Prevent the Spread of African Swine Fever in the European Union Domestic Pig Sector

PubMed Central

Jurado, Cristina; Martínez-Avilés, Marta; De La Torre, Ana; Štukelj, Marina; de Carvalho Ferreira, Helena Cardoso; Cerioli, Monica; Sánchez-Vizcaíno, José Manuel; Bellini, Silvia

2018-01-01

During the past decade, African swine fever (ASF) has spread from the Caucasus region to eastern European Union countries affecting domestic pig and wild boar populations. In order to avert ASF spread, mitigation measures targeting both populations have been established. However, despite these efforts, ASF has been reported in thirteen different countries (Georgia, Azerbaijan, Armenia, the Russian Federation, Ukraine, Belarus, Estonia, Latvia, Lithuania, Poland, Moldova, Czech Republic, and Romania). In the absence of an effective vaccine or treatment to ASF, introduction and spread of ASF onto domestic pig farms can only be prevented by strict compliance to control measures. This study systematically reviewed available measures to prevent the spread of ASF in the EU domestic pig sector distinguishing between commercial, non-commercial, and outdoor farms. The search was performed in PubMed and using a common browser. A total of 52 documents were selected for the final review process, which included scientific articles, reports, EU documents and official recommendations, among others. From this literature review, 37 measures were identified as preventive measures for the introduction and spread of ASF. Subsequently, these measures were assessed by ASF experts for their relevance in the mitigation of ASF spread on the three mentioned types of farms. All experts agreed that some of the important preventive measures for all three types of farms were: the identification of animals and farm records; strict enforcement of the ban on swill feeding; and containment of pigs, so as to not allow direct or indirect pig–pig and/or pig–wild boar contacts. Other important preventive measures for all farms were education of farmers, workers, and operators; no contact between farmers and farm staff and external pigs; appropriate removal of carcasses, slaughter residues, and food waste; proper disposal of manure and dead animals, and abstaining from hunting activities during the previous 48 h (allowing a 48 h interval between hunting and being in contact with domestic pigs). Finally, all experts identified that the important preventive measures for non-commercial and outdoor farms is to improve access of those farms to veterinarians and health services. PMID:29713637

Relevant Measures to Prevent the Spread of African Swine Fever in the European Union Domestic Pig Sector.

PubMed

Jurado, Cristina; Martínez-Avilés, Marta; De La Torre, Ana; Štukelj, Marina; de Carvalho Ferreira, Helena Cardoso; Cerioli, Monica; Sánchez-Vizcaíno, José Manuel; Bellini, Silvia

2018-01-01

During the past decade, African swine fever (ASF) has spread from the Caucasus region to eastern European Union countries affecting domestic pig and wild boar populations. In order to avert ASF spread, mitigation measures targeting both populations have been established. However, despite these efforts, ASF has been reported in thirteen different countries (Georgia, Azerbaijan, Armenia, the Russian Federation, Ukraine, Belarus, Estonia, Latvia, Lithuania, Poland, Moldova, Czech Republic, and Romania). In the absence of an effective vaccine or treatment to ASF, introduction and spread of ASF onto domestic pig farms can only be prevented by strict compliance to control measures. This study systematically reviewed available measures to prevent the spread of ASF in the EU domestic pig sector distinguishing between commercial, non-commercial, and outdoor farms. The search was performed in PubMed and using a common browser. A total of 52 documents were selected for the final review process, which included scientific articles, reports, EU documents and official recommendations, among others. From this literature review, 37 measures were identified as preventive measures for the introduction and spread of ASF. Subsequently, these measures were assessed by ASF experts for their relevance in the mitigation of ASF spread on the three mentioned types of farms. All experts agreed that some of the important preventive measures for all three types of farms were: the identification of animals and farm records; strict enforcement of the ban on swill feeding; and containment of pigs, so as to not allow direct or indirect pig-pig and/or pig-wild boar contacts. Other important preventive measures for all farms were education of farmers, workers, and operators; no contact between farmers and farm staff and external pigs; appropriate removal of carcasses, slaughter residues, and food waste; proper disposal of manure and dead animals, and abstaining from hunting activities during the previous 48 h (allowing a 48 h interval between hunting and being in contact with domestic pigs). Finally, all experts identified that the important preventive measures for non-commercial and outdoor farms is to improve access of those farms to veterinarians and health services.

Principles and Framework for eHealth Strategy Development

PubMed Central

Mars, Maurice

2013-01-01

Significant investment in eHealth solutions is being made in nearly every country of the world. How do we know that these investments and the foregone opportunity costs are the correct ones? Absent, poor, or vague eHealth strategy is a significant barrier to effective investment in, and implementation of, sustainable eHealth solutions and establishment of an eHealth favorable policy environment. Strategy is the driving force, the first essential ingredient, that can place countries in charge of their own eHealth destiny and inform them of the policy necessary to achieve it. In the last 2 years, there has been renewed interest in eHealth strategy from the World Health Organization (WHO), International Telecommunications Union (ITU), Pan American Health Organization (PAHO), the African Union, and the Commonwealth; yet overall, the literature lacks clear guidance to inform countries why and how to develop their own complementary but locally specific eHealth strategy. To address this gap, this paper further develops an eHealth Strategy Development Framework, basing it upon a conceptual framework and relevant theories of strategy and complex system analysis available from the literature. We present here the rationale, theories, and final eHealth strategy development framework by which a systematic and methodical approach can be applied by institutions, subnational regions, and countries to create holistic, needs- and evidence-based, and defensible eHealth strategy and to ensure wise investment in eHealth. PMID:23900066

Principles and framework for eHealth strategy development.

PubMed

Scott, Richard E; Mars, Maurice

2013-07-30

Significant investment in eHealth solutions is being made in nearly every country of the world. How do we know that these investments and the foregone opportunity costs are the correct ones? Absent, poor, or vague eHealth strategy is a significant barrier to effective investment in, and implementation of, sustainable eHealth solutions and establishment of an eHealth favorable policy environment. Strategy is the driving force, the first essential ingredient, that can place countries in charge of their own eHealth destiny and inform them of the policy necessary to achieve it. In the last 2 years, there has been renewed interest in eHealth strategy from the World Health Organization (WHO), International Telecommunications Union (ITU), Pan American Health Organization (PAHO), the African Union, and the Commonwealth; yet overall, the literature lacks clear guidance to inform countries why and how to develop their own complementary but locally specific eHealth strategy. To address this gap, this paper further develops an eHealth Strategy Development Framework, basing it upon a conceptual framework and relevant theories of strategy and complex system analysis available from the literature. We present here the rationale, theories, and final eHealth strategy development framework by which a systematic and methodical approach can be applied by institutions, subnational regions, and countries to create holistic, needs- and evidence-based, and defensible eHealth strategy and to ensure wise investment in eHealth.

Four years (2011-2015) of total gaseous mercury measurements from the Cape Verde Atmospheric Observatory

NASA Astrophysics Data System (ADS)

Read, Katie A.; Neves, Luis M.; Carpenter, Lucy J.; Lewis, Alastair C.; Fleming, Zoe L.; Kentisbeer, John

2017-04-01

Mercury is a chemical with widespread anthropogenic emissions that is known to be highly toxic to humans, ecosystems and wildlife. Global anthropogenic emissions are around 20 % higher than natural emissions and the amount of mercury released into the atmosphere has increased since the industrial revolution. In 2005 the European Union and the United States adopted measures to reduce mercury use, in part to offset the impacts of increasing emissions in industrialising countries. The changing regional emissions of mercury have impacts on a range of spatial scales. Here we report 4 years (December 2011-December 2015) of total gaseous mercury (TGM) measurements at the Cape Verde Observatory (CVO), a global WMO-GAW station located in the subtropical remote marine boundary layer. Observed total gaseous mercury concentrations were between 1.03 and 1.33 ng m-3 (10th, 90th percentiles), close to expectations based on previous interhemispheric gradient measurements. We observe a decreasing trend in TGM (-0.05 ± 0.04 ng m-3 yr-1, -4.2 % ± 3.3 % yr-1) over the 4 years consistent with the reported decrease of mercury concentrations in North Atlantic surface waters and reductions in anthropogenic emissions. The decrease was more visible in the summer (July-September) than in the winter (December-February), when measurements were impacted by air from the African continent and Sahara/Sahel regions. African air masses were also associated with the highest and most variable TGM concentrations. We suggest that the less pronounced downward trend inclination in African air may be attributed to poorly controlled anthropogenic sources such as artisanal and small-scale gold mining (ASGM) in West Africa.

Cretaceous to present kinematics of the Indian, African and Seychelles plates

NASA Astrophysics Data System (ADS)

Eagles, Graeme; Hoang, Ha H.

2014-01-01

An iterative inverse model of seafloor spreading data from the Mascarene and Madagascar basins and the flanks of the Carlsberg Ridge describes a continuous history of Indian-African Plate divergence since 84 Ma. Visual-fit modelling of conjugate magnetic anomaly data from near the Seychelles platform and Laxmi Ridge documents rapid rotation of a Seychelles Plate about a nearby Euler pole in Palaeocene times. As the Euler pole migrated during this rotation, the Amirante Trench on the western side of the plate accommodated first convergence and later divergence with the African Plate. The unusual present-day morphology of the Amirante Trench and neighbouring Amirante Banks can be related to crustal thickening by thrusting and folding during the convergent phase and the subsequent development of a spreading centre with a median valley during the divergent phase. The model fits FZ trends in the north Arabian and east Somali basins, suggesting that they formed in India-Africa Plate divergence. Seafloor fabric in and between the basins shows that they initially hosted a segmented spreading ridge that accommodated slow plate divergence until 71-69 Ma, and that upon arrival of the Deccan-Réunion plume and an increase to faster plate divergence rates in the period 69-65 Ma, segments of the ridge lengthened and propagated. Ridge propagation into the Indian continental margin led first to the formation of the Laxmi Basin, which accompanied extensive volcanism onshore at the Deccan Traps and offshore at the Saurashtra High and Somnath Ridge. A second propagation episode initiated the ancestral Carlsberg Ridge at which Seychelles-India and India-Africa Plate motions were accommodated. With the completion of this propagation, the plate boundaries in the Mascarene Basin were abandoned. Seafloor spreading between this time and the present has been accommodated solely at the Carlsberg Ridge.

E-health: determinants, opportunities, challenges and the way forward for countries in the WHO African Region.

PubMed

Kirigia, Joses M; Seddoh, Anthony; Gatwiri, Doris; Muthuri, Lenity H K; Seddoh, Janet

2005-12-20

The implementation of the 58th World Health Assembly resolution on e-health will pose a major challenge for the Member States of the World Health Organization (WHO) African Region due to lack of information and communications technology (ICT) and mass Internet connectivity, compounded by a paucity of ICT-related knowledge and skills. The key objectives of this article are to: (i) explore the key determinants of personal computers (PCs), telephone mainline and cellular and Internet penetration/connectivity in the African Region; and (ii) to propose actions needed to create an enabling environment for e-health services growth and utilization in the Region. The effects of school enrolment, per capita income and governance variables on the number of PCs, telephone mainlines, cellular phone subscribers and Internet users were estimated using a double-log regression model and cross-sectional data on various Member States in the African Region. The analysis was based on 45 of the 46 countries that comprise the Region. The data were obtained from the United Nations Development Programme (UNDP), the World Bank and the International Telecommunications Union (ITU) sources. There were a number of main findings: (i) the adult literacy and total number of Internet users had a statistically significant (at 5% level in a t-distribution test) positive effect on the number of PCs in a country; (ii) the combined school enrolment rate and per capita income had a statistically significant direct effect on the number of telephone mainlines and cellular telephone subscribers; (iii) the regulatory quality had statistically significant negative effect on the number of telephone mainlines; (iv) similarly, the combined school enrolment ratio and the number of telephone mainlines had a statistically significant positive relationship with Internet usage; and (v) there were major inequalities in ICT connectivity between upper-middle, lower-middle and low income countries in the Region. By focusing on the adoption of specific technologies we attempted to interpret correlates in terms of relationships instead of absolute "causals". In order to improve access to health care, especially for the majority of Africans living in remote rural areas, there is need to boost the availability and utilization of e-health services. Thus, universal access to e-health ought to be a vision for all countries in the African Region. Each country ought to develop a road map in a strategic e-health plan that will, over time, enable its citizens to realize that vision.

E-health: Determinants, opportunities, challenges and the way forward for countries in the WHO African Region

PubMed Central

Kirigia, Joses M; Seddoh, Anthony; Gatwiri, Doris; Muthuri, Lenity HK; Seddoh, Janet

2005-01-01

Background The implementation of the 58th World Health Assembly resolution on e-health will pose a major challenge for the Member States of the World Health Organization (WHO) African Region due to lack of information and communications technology (ICT) and mass Internet connectivity, compounded by a paucity of ICT-related knowledge and skills. The key objectives of this article are to: (i) explore the key determinants of personal computers (PCs), telephone mainline and cellular and Internet penetration/connectivity in the African Region; and (ii) to propose actions needed to create an enabling environment for e-health services growth and utilization in the Region. Methods The effects of school enrolment, per capita income and governance variables on the number of PCs, telephone mainlines, cellular phone subscribers and Internet users were estimated using a double-log regression model and cross-sectional data on various Member States in the African Region. The analysis was based on 45 of the 46 countries that comprise the Region. The data were obtained from the United Nations Development Programme (UNDP), the World Bank and the International Telecommunications Union (ITU) sources. Results There were a number of main findings: (i) the adult literacy and total number of Internet users had a statistically significant (at 5% level in a t-distribution test) positive effect on the number of PCs in a country; (ii) the combined school enrolment rate and per capita income had a statistically significant direct effect on the number of telephone mainlines and cellular telephone subscribers; (iii) the regulatory quality had statistically significant negative effect on the number of telephone mainlines; (iv) similarly, the combined school enrolment ratio and the number of telephone mainlines had a statistically significant positive relationship with Internet usage; and (v) there were major inequalities in ICT connectivity between upper-middle, lower-middle and low income countries in the Region. By focusing on the adoption of specific technologies we attempted to interpret correlates in terms of relationships instead of absolute "causals". Conclusion In order to improve access to health care, especially for the majority of Africans living in remote rural areas, there is need to boost the availability and utilization of e-health services. Thus, universal access to e-health ought to be a vision for all countries in the African Region. Each country ought to develop a road map in a strategic e-health plan that will, over time, enable its citizens to realize that vision. PMID:16364186

Die regionalökonomische Bedeutung der Wissenschaft für das Ruhrgebiet. Hochschulen und außeruniversitäre Forschungseinrichtungen als Motor der regionalen Entwicklung

NASA Astrophysics Data System (ADS)

Kriegesmann, Bernd; Böttcher, Matthias; Lippmann, Torben

2016-09-01

The Ruhr area has advanced to the largest university region in Germany - often unnoticed within and outside. At the same time scientific institutions have become a major economic factor. Because of the higher and extra-university research institutions about 2.5 billion euros are effective as a demand potential in the region. 1.7 billion euros of this amount are directly associated with investments and operating expenditures of the scientific institutions as well as consumptions of employees and students. Additional 770 million euros result in revenues of many branches such as trade, housing, gastronomy sector, handcraft industry etc. It should not be underestimated that higher and extra-university research institutions generate with their research activities particular funding from the European Union or the rest of Germany for benefit of the region. Each euro spent by the state government for basic funding creates 39 cents third-party funding. These regional-economic effects result in noticeable employment impacts within the region. Around 25,000 people are directly employed in higher and extra-university research institutes or student unions (Studierendenwerke), about 22,000 jobs in other economic sectors are ensured or created by the induced demand. Science has thus become an important economic factor and represents an essential counterbalance to employment decline in shrinking industries of the region. The specific inclusion of science in a regional development strategy and targeted relining with appropriate measures to strengthen the science creates therefore an effective starting point for the design of structural change.

HIV status, gender, and marriage dynamics among adults in Rural Malawi

PubMed Central

Anglewicz, Philip; Reniers, Georges

2014-01-01

Marriage and partnerships bring about non-negligible health risks in populations with generalized HIV epidemics, and concerns about the possible transmission of HIV thus often factor in the decision-making about partnership formation and dissolution. The awareness of and responses to HIV risk stemming from regular sexual partners have been well documented in African populations, but few studies have estimated the effects of observed HIV status on marriage decisions and outcomes. We study marriage dissolution and remarriage using longitudinal data with repeated HIV and marital status measurements from rural Malawi. Results indicate that HIV positive individuals face greater risks of union dissolution (both via widowhood and divorce) and lower remarriage rates. Modeling studies suggest that the exclusion of HIV positives from the marriage or partnerships market will decelerate the propagation of HIV. PMID:25469927

[Consanguineous marriage and morbi-mortality, short literature review based on an exceptional association: Usher syndrome and Von Recklinghausen neurofibromatosis].

PubMed

Atipo-Tsiba, Pépin-Williams

2016-01-01

Usher syndrome is defined by the association of a progressive or non-progressive congenital sensorineural hearing loss with variable severity and a gradually blinding pigmentary retinopathy. Von Recklinghausen neurofibromatosis or Neurofibromatosis type 1 is the major clinically form of neurofibromatosis which occurs in approximately 90% of cases. Both types of disease are genetic in origin with very low prevalence. The probability of co-occurrence of these diseases in a single individual is exceptional. Inbreeding, as well as all genetic diseases, increases quite significantly the probability of their occurrence. Consanguineous marriages are still widespread in Maghreb and in some regions of the western African. This observation reports an exceptional case of this association in a 40-year-old man of Mauritanian origin born from a consanguineous union.

Southern African Office of Astronomy for Development: A New Hub for Astronomy for Development

NASA Astrophysics Data System (ADS)

Mutondo, Moola S.; Simpemba, Prospery

2016-10-01

A new Astronomy for Development hub needs innovative tools and programs. SAROAD is developing exciting tools integrating Raspberry Pi technology to bring cost-effective astronomy content to learning centres. SAROAD would also like to report achievements in realizing the IAU's strategic plan. In order to manage, evaluate and coordinate regional IAU (International Astronomical Union) capacity building programmes, including the recruitment and mobilization of volunteers, SAROAD has built an intranet that is accessible to regional members upon request. Using this resource, regional members can see and participate in regional activities. SAROAD has commenced with projects in the three Task Force areas of Universities and Research, Children and Schools and Public Outreach. Under the three Task Force areas, a total of seven projects have commenced in Zambia (some supported by funds from IAU Annual Call for proposals).

The organized sector mobilizes against AIDS.

PubMed

Mehra-kerpelman, K

1995-01-01

Representatives of English speaking African countries attended the International Labor Organization Tripartite Workshop on the Role of the Organized Sector in Reproductive Health and the Prevention of AIDS held in Uganda. AIDS has robbed these countries of lawyers, physicians, teachers, managers, and other skilled professionals, all of whom are difficult to replace. HIV/AIDS mainly affects persons in their most productive years (20-40 years) and in the higher socioeconomic groups. Professionals with AIDS become ill and die at a faster rate than their replacements can be trained. The young, less experienced work force translates into an increase in breakdowns, accidents, delays, and misjudgments. International and national efforts to control HIV/AIDS have not stopped the spread of HIV in Sub-Saharan Africa (SSA). More than 8 million persons in SSA are HIV infected. 1.5 million in Uganda are HIV infected. As of October 1994, 30,000 persons in Zambia and 33,000 in Zimbabwe had AIDS. These numbers are just the tip of the iceberg due to underreporting. HIV/AIDS increases absenteeism among infected and healthy workers alike. It burdens the already existing scarce health care resources and equipment (e.g., in 1992, AIDS cases occupied 70% of hospital beds in Kigali, Rwanda). Unions, workers, and families must share knowledge about safer sex. The Zimbabwe Confederation of Trade Unions has had an HIV/AIDS education program since 1992. The Zambia Congress of Trade Unions strongly supports government efforts to sensitize the labor force and society to the effects of HIV/AIDS. The Federation of Uganda Employers has reached about 150,000 workers and more than 200 top executives through its AIDS prevention activities. Some company programs provide medical facilities for employees and their families. The Ubombo Ranches, Ltd. in Swaziland, a producer and processor of sugar cane, has a training-of-trainers program on HIV/AIDS and family planning for all village health workers and village headmen.

Development of a simple gel permeation clean-up procedure coupled to a rapid disequilibrium enzyme-linked immunosorbent assay (ELISA) for the detection of Sudan I dye in spices and sauces.

PubMed

Oplatowska, Michalina; Stevenson, Paul J; Schulz, Claudia; Hartig, Lutz; Elliott, Christopher T

2011-09-01

Sudan dyes have been found to be added to chilli and chilli products for illegal colour enhancement purposes. Due to the possible carcinogenic effect, they are not authorized to be used in food in the European Union or the USA. However, over the last few years, many products imported from Asian and African countries have been reported via the Rapid Alert System for Food and Feed in the European Union to be contaminated with these dyes. In order to provide fast screening method for the detection of Sudan I (SI), which is the most widely abused member of Sudan dyes family, a unique (20 min without sample preparation) direct disequilibrium enzyme-linked immunosorbent assay (ELISA) was developed. The assay was based on polyclonal antibodies highly specific to SI. A novel, simple gel permeation chromatography clean-up method was developed to purify extracts from matrices containing high amounts of fat and natural pigments, without the need for a large dilution of the sample. The assay was validated according to the Commission Decision 2002/657/EC criteria. The detection capability was determined to be 15 ng g(-1) in sauces and 50 ng g(-1) in spices. The recoveries found ranged from 81% to 116% and inter- and intra-assay coefficients of variation from 6% to 20%. The assay was used to screen a range of products (85 samples) collected from different retail sources within and outside the European Union. Three samples were found to contain high amounts (1,649, 722 and 1,461 ng g(-1)) of SI by ELISA. These results were confirmed by liquid chromatography-tandem mass spectrometry method. The innovative procedure allows for the fast, sensitive and high throughput screening of different foodstuffs for the presence of the illegal colorant SI.

Utilisation des méthodes contraceptives modernes en République Démocratique du Congo: prévalence et barrières dans la zone de santé de Dibindi à Mbuji-Mayi

PubMed Central

Ntambue, Abel Mukengeshayi; Tshiala, Rachel Ngalula; Malonga, Françoise Kaj; Ilunga, Tabitha Mpoyi; Kamonayi, Josaphat Mulumba; Kazadi, Simon Tshimankinda; Matungulu, Charles Matungu; Musau, Angel Nkola; Mulamba, Diese; Dramaix-Wilmet, Michèle; Donnen, Philippe

2017-01-01

Introduction l’objectif de cette étude était de déterminer la prévalence contraceptive moderne et les barrières à l’utilisation des méthodes contraceptives modernes chez les couples de la Zone de Santé Dibindi, à Mbuji-Mayi en République Démocratique du Congo. Méthodes de Mai à Juin 2015, nous avons réalisé une étude descriptive transversale. Nous avons inclus les femmes âgées de 15 à 49 ans, en union maritale, non enceinte au moment de l’enquête, qui habitaient la Zone de santé Dibindi depuis deux ans et ayant consenti librement de participer à l’étude. La collecte des données a été réalisée par interview libre des femmes. La prévalence contraceptive moderne se référait aux femmes en cours d’utilisation, au moment de l’enquête, des contraceptifs modernes. La comparaison des proportions a été réalisée au seuil de signification de 5%. Le test de Bonferroni a été utilisé pour comparer, deux à deux, les proportions des barrières à l’utilisation des contraceptifs modernes. Résultats la prévalence contraceptive moderne à Dibindi, en 2015, était de 18,4%. Elle était faible eu égard aux services de planification familiale disponibles dans cette Zone de santé. Plusieurs femmes refusaient d’utiliser les méthodes contraceptives modernes malgré l’information dont elles disposaient à cause de leur désir de maternité, l’interdiction religieuse, l’opposition du conjoint et la crainte des effets secondaires. Conclusion l’information suffisante et centrée sur chaque cliente ou son couple, sur la planification familiale, devrait être renforcée de façon à éliminer les fausses croyances, ce qui accroitrait l’utilisation des méthodes contraceptives modernes. PMID:28674592

Magma chamber history related to the shield building stage of Piton des Neiges volcano, La Réunion Island

NASA Astrophysics Data System (ADS)

Berthod, Carole; Michon, Laurent; Famin, Vincent; Bascou, Jérôme; Bachelery, Patrick

2016-04-01

Piton des Neiges volcano (La Réunion hotspot) experienced a long-lasting shield building stage before entering its degenerative stage 0.4 my ago. The deep edifice incision due to the intense tropical erosion allowed the description for several decades of a layered gabbroic complex interpreted as a piece of magma chamber, which has been tectonically displaced (Chevallier & Vatin-Perignon, 1982; Upton & Wadsworth, 1972). Here, we combine field investigations, petrographic, mineralogical, geochemical and anisotropy of magnetic susceptibility (AMS) studies to constrain the spatial distribution of the plutonic complex, to identify the physical and chemical processes and to integrate this complex in the evolution of Piton des Neiges (PdN). Field investigations allowed us to discover three additional massifs of gabbro and peridotite along the Mât River. The four massifs are overlaid by a pile of basic sills and a breccia interpreted as a debris avalanche deposit. Albeit spatially disconnected, the massifs show a relatively constant dip of the magnetic foliation toward the current summit of the volcano (i.e. toward the SSE). The two massifs cropping in the upper Mât River are exclusively composed of massive dunite and wherlite units with a cumulate texture and no visible dynamic structures. The two massifs located in the lower Mât River are made of olivine-gabbro, ferrogabbro and gabbro showing numerous flow structures and synmagmatic faults that indicates instabilities which trend NNW-SSE. Minerals (olivine, clinopyroxene and oxide) present primitive compositions in the two upper massifs and slightly differentiated ones in the lower massif. Given the consistency of our dataset, we propose that the four massifs correspond to outcrops of a unique chemically stratified magma chamber, whose center would have been located about 4 km North of the current summit of PdN. The existence of an initial PdN, North of the current edifice, is supported by morphological reconstruction, gravimetric data (Gailler & Lénat, 2012) and submarine sedimentation (Lebas, 2012). It would have been built prior to 2 Ma and subsequently experienced a large north-directed destabilization. The PdN volcano later reconstructed south of the initial magmatic centre. Chevallier, L., & Vatin-Perignon, N. (1982). Volcano-structural evolution of Piton des Neiges, Reunion Island, Indian Ocean. Bulletin of Volcanology, 45(4), 285-298. Gailler, L.-S., & Lénat, J.-F. (2012). Internal architecture of La Réunion (Indian Ocean) inferred from geophysical data. Journal of Volcanology and Geothermal Research, 221-222(C), 83-98. http://doi.org/10.1016/j.jvolgeores.2012.01.015 Lebas, E. (2012). Processus de démantèlement des édifices volcaniques au cours de leur évolution : Application à La Réunion et Montserrat et comparaison avec d'autres édifices. Unpublished PhD Thesis, 1-379. Upton, B. G. J., & Wadsworth, W. (1972). Peridotitic and gabbroic rocks associated with the shield-forming lavas of Réunion. Contributions to Mineralogy and Petrology, 35, 139-158.

Estrogen receptor protein content is different in abdominal than gluteal subcutaneous adipose tissue of overweight-to-obese premenopausal women.

PubMed

Gavin, Kathleen M; Cooper, Elizabeth E; Hickner, Robert C

2013-08-01

Premenopausal women demonstrate a distinctive gynoid body fat distribution and circulating estrogen status is associated with the maintenance of this adiposity patterning. Estrogen's role in modulation of regional adiposity may occur through estrogen receptors (ERs), which are present in human adipose tissue. The purpose of this study was to determine regional differences in the protein content of ERα, ERβ, and the G protein-coupled estrogen receptor (GPER) between the abdominal (AB) and gluteal (GL) subcutaneous adipose tissue of overweight-to-obese premenopausal women. Biopsies of the subcutaneous AB and GL adipose tissue were performed in 15 premenopausal women (7 Caucasian/8 African American, 25.1 ± 1.8 years, BMI 29.5 ± 0.5kg/m(2)). Adipose tissue protein content was measured by western blot analysis and correlation analyses were conducted to assess the relationship between ER protein content and anthropometric indices/body composition measurements. We found that ERα protein was higher in AB than GL (AB 1.0 ± 0.2 vs GL 0.67 ± 0.1 arbitrary units [AU], P=0.02), ERβ protein was higher in GL than AB (AB 0.78 ± 0.12 vs GL 1.3 ± 0.2 AU, P=0.002), ERα/ERβ ratio was higher in AB than GL (AB 1.9 ± 0.4 vs GL 0.58 ± 0.08 AU, P=0.007), and GPER protein content was similar in AB and GL (P=0.80) subcutaneous adipose tissue. Waist-to-hip ratio was inversely related to gluteal ERβ (r(2)=0.315, P=0.03) and positively related to gluteal ERα/ERβ ratio (r(2)=0.406, P=0.01). These results indicate that depot specific ER content may be an important underlying determinant of regional effects of estrogen in upper and lower body adipose tissue of overweight-to-obese premenopausal women. Copyright © 2013 Elsevier Inc. All rights reserved.

Jamaica.

PubMed

1987-01-01

The U.S. State Department's background notes on the Caribbean island nation of Jamaica discusses geography, people, history, government, defense and foreign relations, with lengthier sections on politics and economy. Jamaica, lying south of Cuba, has 10,991 sq. km., 2.3 million people of African and African-European origin primarily, a growth rate of 1.1%, infant mortality rate of 28/1000 and life expectancy of 71 years. The island has diverse climatic regions, mountainous structure, rich resources in bauxite, and agriculture. It was settled in the 1500s by Spain, occupied since 1670 Britain, and became independent in 1962. The first election in 1945 established the roots of the government, modeled after the British system. The 2 major parties, derived from preceding labor unions, are the Jamaican Labour Party, centrist but favoring private business and agriculture, and the People's National Party, more populist and socialist. The economy has suffered in recent years from recession, unemployment, high interest rates, international trade deficit and government spending deficits, as well as a brief alignment with Cuba that discouraged both tourism and foreign investment. Initiatives from U.S. investors have begun to reverse the trend, concentrating on establishment of light industry such as garment making and data entry. Jamaica's wealth in her stable government, literate population, natural resources, fertile soil, and good relations with other nations and institutions suggest that she will rise above her economic troubles.

African swine fever (ASF): five years around Europe.

PubMed

Sánchez-Vizcaíno, José Manuel; Mur, Lina; Martínez-López, Beatriz

2013-07-26

Since African swine fever (ASF) was re-introduced into Eastern Europe in April 2007, the disease has spread through five countries, drastically changing the European ASF situation. This re-introduction has significant implications for the affected countries, and it puts the European Union (EU) at serious risk of ASF introduction. Numerous factors are complicating the control of ASF in the Russian Federation and neighboring areas, particularly the absence of a coordinated control program, the abundance of backyard pig units with low or no biosecurity and the traditional use of swill feeding. All these risk factors are driven in turn by socio-economic, political and cultural factors. Moreover, the lack of clear information regarding the current situation of ASF in the Trans-Caucasus countries such as Armenia and Georgia may be increasing the risk of ASF spread into neighboring areas. The ASF situation in Eastern Europe poses a constant risk of ASF entry into the EU, especially via routes that are difficult to control, such as wild boar movements, illegal movement of animals and animal products and movements of contaminated vehicles or other fomites. This paper reviews and discusses current ASF epidemiology in Eastern Europe, the factors that may contribute to disease endemicity in the area, the current challenges for disease control, and the risk of introduction into the EU. Copyright © 2012 Elsevier B.V. All rights reserved.

Spinal cord injuries in South African Rugby Union (1980 - 2007).

PubMed

Hermanus, Fiona J; Draper, Catherine E; Noakes, Timothy D

2010-03-30

To address an apparent increase in the number of rugby-related spinal cord injuries (SCIs) in South Africa, a retrospective case-series study was conducted on injuries that occurred between 1980 and 2007. We aimed to identify preventable causes to reduce the overall rate of SCIs in South African rugby. We identified 264 rugby-related SCIs. A structured questionnaire was used, and it was possible to obtain information on a total of 183 players, including 30 who had died. SCIs increased in number in the 1980s and in 2006. Forwards sustained 76% of all SCIs, and club players 60%. Players aged 17 had the highest number of SCIs. In only 50% of cases were medical personnel present at the time of injury, and 49% of injured players waited longer than 6 hours for acute management. Of players with an SCI, 61% had a catastrophic outcome after 12 months, including 8% who died during that time; 65% received no financial compensation; and only 29% of players had medical aid or health insurance. A register of all rugby-related SCIs in South Africa is essential to monitor the magnitude of the problem, identify potential risk factors, and formulate appropriate preventive interventions. The lack of reliable denominator data limits calculation of incident rates. Players from previously disadvantaged communities in particular suffered the consequences of limited public health care resources and no financial compensation.

HIV / AIDS and the law.

PubMed

1997-09-01

Since HIV is sexually transmitted, people living with AIDS and HIV (PWA/PHA) risk being stigmatized as immoral and promiscuous and they are often discriminated against in society. To this effect, the South African AIDS Law Project and Lawyers for Human Rights have developed a comprehensive resource manual detailing human rights with a special emphasis on issues relevant to PWA/PHA. The concept of the manual aimed to look at the legal and human rights questions that have been raised by the HIV/AIDS epidemic; inform people living with HIV/AIDS about their rights and the law; provide people working in businesses, trade unions, and nongovernmental organization with information about correct and incorrect responses to HIV/AIDS; and give victims of discrimination ideas on how to fight back. This manual initially introduces basic facts about HIV and AIDS and then describes the legal system and the Bill of Rights within the new South African Constitution. The main areas of focus in the manual include: 1) patient's medical rights, 2) employment rights, 3) women's rights, 4) the rights of lesbians and gay men, 5) the rights of youth and children, 6) the rights of prisoners, 7) social support for PWA, 8) HIV/AIDS and insurance law, 9) power of attorney and making wills, 10) criminal law, and 11) legal remedies, such as using the law to protect one's rights.

Lion (Panthera leo) populations are declining rapidly across Africa, except in intensively managed areas.

PubMed

Bauer, Hans; Chapron, Guillaume; Nowell, Kristin; Henschel, Philipp; Funston, Paul; Hunter, Luke T B; Macdonald, David W; Packer, Craig

2015-12-01

We compiled all credible repeated lion surveys and present time series data for 47 lion (Panthera leo) populations. We used a Bayesian state space model to estimate growth rate-λ for each population and summed these into three regional sets to provide conservation-relevant estimates of trends since 1990. We found a striking geographical pattern: African lion populations are declining everywhere, except in four southern countries (Botswana, Namibia, South Africa, and Zimbabwe). Population models indicate a 67% chance that lions in West and Central Africa decline by one-half, while estimating a 37% chance that lions in East Africa also decline by one-half over two decades. We recommend separate regional assessments of the lion in the World Conservation Union (IUCN) Red List of Threatened Species: already recognized as critically endangered in West Africa, our analysis supports listing as regionally endangered in Central and East Africa and least concern in southern Africa. Almost all lion populations that historically exceeded ∼ 500 individuals are declining, but lion conservation is successful in southern Africa, in part because of the proliferation of reintroduced lions in small, fenced, intensively managed, and funded reserves. If management budgets for wild lands cannot keep pace with mounting levels of threat, the species may rely increasingly on these southern African areas and may no longer be a flagship species of the once vast natural ecosystems across the rest of the continent.

Electronic and geometric structures of Au30 clusters: a network of 2e-superatom Au cores protected by tridentate protecting motifs with u3-S

NASA Astrophysics Data System (ADS)

Tian, Zhimei; Cheng, Longjiu

2015-12-01

Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters.Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters. Electronic supplementary information (ESI) available: The AdNDP localized natural bonding orbitals of the valence shells of the Au30S(SH)18 cluster. IR spectra, absorption spectra and coordinates of Au30S(SCH3)18, Au30(SCH3)18 and Au30S2(SCH3)18 clusters. See DOI: 10.1039/c5nr05020k

Le rôle de l’omalizumab dans le traitement de l’asthme allergique grave

PubMed Central

Chapman, Kenneth R; Cartier, André; Hébert, Jacques; McIvor, R Andrew; Schellenberg, R Robert

2006-01-01

CONTEXTE : Un nouveau traitement anti-immunoglobuline E (anti-IgE) contre l’asthme, l’omalizumab, a été approuvé au Canada. OBJECTIF : Passer en revue les données fondamentales et cliniques sur l’omalizumab et examiner le rôle possible de ce médicament dans la prise en charge de l’asthme au Canada. MÉTHODOLOGIE : Une recherche documentaire a été effectuée dans MEDLINE afin de repérer les études menées de 1960 à 2006 sur l’omalizumab. La recherche a également porté sur les résumés de réunions scientifiques récentes dans le domaine des maladies respiratoires et des allergies; par ailleurs, toute donnée non publiée a été demandée au fabricant. Après avoir revu et résumé les données, un comité mixte constitué de spécialistes des maladies respiratoires et des allergies a rédigé un ensemble de recommandations relatives à l’utilisation de l’omalizumab. RÉSULTATS : L’omalizumab est un anticorps monoclonal humanisé qui se lie au domaine C epsilon 3 de la molécule d’IgE pour former des complexes immuns solubles qui sont éliminés par le système réticulo-endothélial. L’administration d’injections sous-cutanées espacées de deux ou de quatre semaines à la dose recommandée entraîne une diminution rapide des taux d’IgE circulantes libres. Lors de deux essais cliniques de phase III menés auprès de 1 405 adultes et adolescents atteints d’asthme modéré à grave qui recevaient des doses moyennes stables de corticostéroïdes en inhalation (CSI), l’omalizumab a diminué les taux d’exacerbation par rapport au placebo et a été associé à une amélioration des symptômes ainsi qu’à une épargne plus importante des corticostéroïdes. Dans un essai mené auprès de 419 patients atteints d’asthme grave non maîtrisé malgré l’utilisation de doses élevées de CSI et de la prise concomitante d’agonistes bêta-2 à action prolongée, les exacerbations graves étaient de 50 % moins fréquentes chez les patients traités par l’omalizumab que chez les sujets témoins. Des analyses rétrospectives ont permis d’identifier les caractéristiques des patients les plus susceptibles de répondre au traitement par l’omalizumab. RECOMMANDATIONS : L’omalizumab pourrait être envisagé comme traitement d’appoint dans les cas atopiques d’asthme grave non maîtrisé avec des traitements classiques par des doses optimales de CSI et un traitement d’appoint approprié (p. ex. : agonistes bêta-2 à action prolongée). En général, les patients sont classés en fonction de leur recours – traitement court et fréquent ou continu et oral – aux corticostéroïdes. Il ne faut amorcer le traitement qu’après avoir consulté un spécialiste pour confirmer le diagnostic et s’assurer que le traitement classique est optimal.

Does economic, financial and institutional developments matter for environmental quality? A comparative analysis of EU and MEA countries.

PubMed

Abid, Mehdi

2017-03-01

The aim of this study is to test the hypothesis of the Environmental Kuznets Curve (EKC) with a sample of 58 MEA (Middle East & African) and 41 EU (European Union) countries for the period 1990 to 2011. The empirical analysis is carried out using the GMM-system method to solve the problem of endogenous variables. We focused on direct and indirect effects of institutional quality (through the efficiency of public expenditure, financial development, trade openness and foreign direct investment) and the income-emission relationship. We found a monotonically increasing relationship between CO 2 emissions and GDP in both MEA and EU regions. The policy implication is clear: in order to have sustainable positive economic performance and to reduce carbon dioxide emission in the country at the same time, policy makers should regulate and enhance the role and efficiency of domestic institutions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Data-protection standards and confidentiality of HIV/AIDS status in the workplace - a South African case study.

PubMed

Muskat-Gorska, Zuzanna

2008-11-01

The article contextualises an emerging new regime for information privacy in South Africa (i.e. the draft Protection of Personal Information Bill). Subsequently, it discusses the possibility of successful implementation of international data-protection standards in an environment where there is an urgent need to balance HIV/AIDS confidentiality rights with public health requirements. Also, the article presents a preliminary assessment of the possible impact of professionalisation (and outsourcing) of workplace HIV/AIDS management on workplace data-protection practices, and it identifies some spaces for social dialogue on HIV/AIDS-data treatment in South Africa. The study methods comprise an analysis of legal documents (concerning international data-protection standards and the development of law governing data protection and HIV/AIDS confidentiality in South Africa) and interviews conducted with workplace health managers and trade union representatives, in Johannesburg, in 2007.

75 FR 17083 - Fiduciary Duties at Federal Credit Unions; Mergers and Conversions of Insured Credit Unions...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-05

... Credit Unions; Mergers and Conversions of Insured Credit Unions; Correction AGENCY: National Credit Union... Federal credit unions and mergers and conversions of insured credit unions. The proposed rule as published... Conversions of Insured Credit Unions) in the e-mail subject line.'' [[Page 17084

[Abdominal obesity and other cardiometabolic risk biomarkers: influence of socioeconomic status and lifestyle on two African-origin population groups, Cotonou (Benin) and Port-au-Prince (Haiti)].

PubMed

Mabchour, Asma El; Delisle, Hélène; Vilgrain, Colette; Larco, Phillipe; Sodjinou, Roger

2016-01-01

Increased cardio metabolic risk (CMR) in low- and middle-income countries is largely due to rapid nutrition transition. We conducted a study of two African-origin populations groups living, however, in widely different settings. It aimed to assess the relationship between lifestyle and CMR biomarkers as well as between abdominal obesity (AO) and other biomarkers. The study included 200 Benineses from Cotonou and 252 Haitians from Port-with-Prince (PAP) aged between 25 to 60 years and apparently in good health. AO was specifically defined as waist circumference ≥ 88cm (men) and ≥ 95 cm (women). Other most common biomarkers were: high total cholesterol/HDL cholesterol ratio, high blood pressure and insulin resistance by HOMA (Homeostasis Model Assessement). Socioeconomic status, diet, alcohol and tobacco were documented by questionnaire. Two dietary patterns emerged from cluster analysis, one traditional and the other "transitional" with increasing frequency of western foods. Socioeconomic status, consumption of alcohol and nicotinism were associated with CMR, but not the food diagram. AO was associated with other CMR markers, with no marked effect of socioeconomic status and lifestyle variables. Specific TT threshold values are confirmed as socioeconomic status and lifestyle have an impact on CMR, but not the relationship between AO and other CMR biomarkers.

Ultra-relativistic Au+Au and d+Au collisions:

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

In this talk I will review PHOBOS data on charged particle multiplicities, obtained in Au+Au and d+Au collisions at RHIC. The general features of the Au+Au pseudorapidity distributions results will be discussed and compared to those of /line{p}p collisions. The total charged particle multiplicity, scaled by the number of participant pairs, is observed to be about 40% higher in Au+Au collisions than in /line{p}p and d+Au systems, but, surprisingly at the same level of e+e- collisions. Limiting fragmentation scaling is seen to be obeyed in Au+Au collisions.

Energy intake and expenditure assessed 'in-season' in an elite European rugby union squad.

PubMed

Bradley, Warren J; Cavanagh, Bryce; Douglas, William; Donovan, Timothy F; Twist, Craig; Morton, James P; Close, Graeme L

2015-01-01

Rugby union (RU) is a complex high-intensity intermittent collision sport with emphasis placed on players possessing high lean body mass and low body fat. After an 8 to 12-week pre-season focused on physiological adaptations, emphasis shifts towards competitive performance. However, there are no objective data on the physiological demands or energy intake (EI) and energy expenditure (EE) for elite players during this period. Accordingly, in-season training load using global positioning system and session rating of perceived exertion (sRPE), alongside six-day assessments of EE and EI were measured in 44 elite RU players. Mean weekly distance covered was 7827 ± 954 m and 9572 ± 1233 m with a total mean weekly sRPE of 1776 ± 355 and 1523 ± 434 AU for forwards and backs, respectively. Mean weekly EI was 16.6 ± 1.5 and 14.2 ± 1.2 megajoules (MJ) and EE was 15.9 ± 0.5 and 14 ± 0.5 MJ. Mean carbohydrate (CHO) intake was 3.5 ± 0.8 and 3.4 ± 0.7 g.kg(-1) body mass, protein intake was 2.7 ± 0.3 and 2.7 ± 0.5 g.kg(-1) body mass, and fat intake was 1.4 ± 0.2 and 1.4 ± 0.3 g.kg(-1) body mass. All players who completed the food diary self-selected a 'low' CHO 'high' protein diet during the early part of the week, with CHO intake increasing in the days leading up to a match, resulting in the mean EI matching EE. Based on EE and training load data, the EI and composition seems appropriate, although further research is required to evaluate if this diet is optimal for match day performance.

Grammaire de l’expérience romantique adolescente au Québec: une analyse sociosémantique des idéaux amoureux

PubMed Central

Blais, Martin; Hébert-Ratté, Roxanne; Hébert, Martine; Lavoie, Francine

2016-01-01

Cette étude vise à décrire, à travers les thèmes qu’évoque la plus belle expérience amoureuse chez de jeunes Québécois âgés de 14 à 19 ans, les formes sémantiques de l’amour contemporain ainsi que les attentes et les paradoxes dont elles témoignent sur le plan communicationnel. Au total, 6 961 jeunes Québécois âgés de 14 à 18 ans recrutés dans les milieux scolaires ont décrit leur plus belle expérience amoureuse vécue ou souhaitée. Une analyse des champs lexicaux, réalisée avec le logiciel Sémato, a permis de dégager six (6) formes sémantiques dominantes: 1) la fidélité, le respect et l’authenticité, 2) les références à la sensualité (embrasser et enlacement), 3) l’ancrage de l’amour idéal dans la compagnie de l’autre et des activités concrètes, 4) l’importance de la passion, de la magie (pour les deux genres) et, surtout pour les garçons, du plaisir, 5) l’ancrage de l’idéal amoureux dans des projets d’union et d’enfants, et 6) l’ancrage du couple dans des lieux précis, dans un quotidien ou des souvenirs tangibles. Ces formes sémantiques sont discutées en fonction des problèmes qu’elles ont pu résoudre et ceux qu’elles font émerger. Les différences de genre sont aussi discutées. PMID:27917004

Screen-printed electrode based electrochemical detector coupled with ionic liquid dispersive liquid-liquid microextraction and microvolume back-extraction for determination of mercury in water samples.

PubMed

Fernández, Elena; Vidal, Lorena; Martín-Yerga, Daniel; Blanco, María del Carmen; Canals, Antonio; Costa-García, Agustín

2015-04-01

A novel approach is presented, whereby gold nanostructured screen-printed carbon electrodes (SPCnAuEs) are combined with in-situ ionic liquid formation dispersive liquid-liquid microextraction (in-situ IL-DLLME) and microvolume back-extraction for the determination of mercury in water samples. In-situ IL-DLLME is based on a simple metathesis reaction between a water-miscible IL and a salt to form a water-immiscible IL into sample solution. Mercury complex with ammonium pyrrolidinedithiocarbamate is extracted from sample solution into the water-immiscible IL formed in-situ. Then, an ultrasound-assisted procedure is employed to back-extract the mercury into 10 µL of a 4 M HCl aqueous solution, which is finally analyzed using SPCnAuEs. Sample preparation methodology was optimized using a multivariate optimization strategy. Under optimized conditions, a linear range between 0.5 and 10 µg L(-1) was obtained with a correlation coefficient of 0.997 for six calibration points. The limit of detection obtained was 0.2 µg L(-1), which is lower than the threshold value established by the Environmental Protection Agency and European Union (i.e., 2 µg L(-1) and 1 µg L(-1), respectively). The repeatability of the proposed method was evaluated at two different spiking levels (3 and 10 µg L(-1)) and a coefficient of variation of 13% was obtained in both cases. The performance of the proposed methodology was evaluated in real-world water samples including tap water, bottled water, river water and industrial wastewater. Relative recoveries between 95% and 108% were obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

The Air University 404 Page

Science.gov Websites

(National Guard) AFITC Conference Air Force Information Technology and Cyberpower Conference graphic The Air Air University Banner AU Home AETC AU FAQs AU Index AU Schools AU Site Contacts USAF AF Recruiting AFRC Recruiting AU Links About Air University AU Academic Office AU Accreditation AU Board of Visitors

High-performance liquid chromatographic analysis of as-synthesised N,N'-dimethylformamide-stabilised gold nanoclusters product

NASA Astrophysics Data System (ADS)

Xie, Shunping; Paau, Man Chin; Zhang, Yan; Shuang, Shaomin; Chan, Wan; Choi, Martin M. F.

2012-08-01

Reverse-phase high-performance liquid chromatographic (RP-HPLC) separation and analysis of polydisperse water-soluble gold nanoclusters (AuNCs) stabilised with N,N'-dimethylformamide (DMF) were investigated. Under optimal elution gradient conditions, the separation of DMF-AuNCs was monitored by absorption and fluorescence spectroscopy. The UV-vis spectral characteristics of the separated DMF-AuNCs have been captured and they do not possess distinct surface plasmon resonance bands, indicating that all DMF-AuNCs are small AuNCs. The photoluminescence emission spectra of the separated DMF-AuNCs are in the blue-light region. Moreover, cationic DMF-AuNCs are for the first time identified by ion chromatography. Our proposed RP-HPLC methodology has been successfully applied to separate AuNCs of various Au atoms as well as DMF-stabilised ligands. Finally, the composition of the separated DMF-AuNCs was confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and electrospray ionisation mass spectrometry, proving that the as-synthesised DMF-AuNCs product consists of Au10+, Au10, Au11, Au12, Au13, and Au14 NCs stabilised with various numbers of DMF ligands.Reverse-phase high-performance liquid chromatographic (RP-HPLC) separation and analysis of polydisperse water-soluble gold nanoclusters (AuNCs) stabilised with N,N'-dimethylformamide (DMF) were investigated. Under optimal elution gradient conditions, the separation of DMF-AuNCs was monitored by absorption and fluorescence spectroscopy. The UV-vis spectral characteristics of the separated DMF-AuNCs have been captured and they do not possess distinct surface plasmon resonance bands, indicating that all DMF-AuNCs are small AuNCs. The photoluminescence emission spectra of the separated DMF-AuNCs are in the blue-light region. Moreover, cationic DMF-AuNCs are for the first time identified by ion chromatography. Our proposed RP-HPLC methodology has been successfully applied to separate AuNCs of various Au atoms as well as DMF-stabilised ligands. Finally, the composition of the separated DMF-AuNCs was confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and electrospray ionisation mass spectrometry, proving that the as-synthesised DMF-AuNCs product consists of Au10+, Au10, Au11, Au12, Au13, and Au14 NCs stabilised with various numbers of DMF ligands. This article was submitted as part of a Themed Issue on metallic clusters. Other papers on this topic can be found in issue 14 of vol. 4 (2012). This issue can be found from the Nanoscale homepage [http://www.rsc.org/nanoscale].

Le don après un décès d'origine cardiocirculatoire au Canada

PubMed Central

Shemie, Sam D.; Baker, Andrew J.; Knoll, Greg; Wall, William; Rocker, Graeme; Howes, Daniel; Davidson, Janet; Pagliarello, Joe; Chambers-Evans, Jane; Cockfield, Sandra; Farrell, Catherine; Glannon, Walter; Gourlay, William; Grant, David; Langevin, Stéphan; Wheelock, Brian; Young, Kimberly; Dossetor, John

2006-01-01

Résumé Ces recommandations sont le fruit d'un processus multidisciplinaire national ayant duré un an et visant à déterminer si et comment l'on pourrait procéder au don d'organes après un décès d'origine cardiocirculatoire («don après le décès cardiocirculatoire», ou DDC) au Canada. Le forum national organisé en février 2005 a permis aux participants de discuter et d'élaborer des recommandations sur les principes, interventions et pratiques se rapportant au DDC. Les aspects éthiques et juridiques ont été abordés dans les discussions. À la fin du Forum, la majorité des participants ont été favorables à l'implantation de programmes de DDC au Canada. Les participants du Forum ont également convenu qu'il fallait formuler et prôner des valeurs fondamentales pour orienter l'élaboration de programmes et de protocoles basés sur le cadre médical, éthique et juridique établi lors de cette réunion. Même si la possibilité d'un don d'organes et de tissus doit faire partie intégrante des soins de fin de vie, il faut insister sur le fait que le devoir de diligence envers les patients mourants et leurs familles doit demeurer la priorité des équipes soignantes. La complexité et les répercussions profondes du décès sont reconnues et doivent être respectées, de même que les différences personnelles, ethnoculturelles et religieuses face à la mort et au don d'organes. Les décisions d'arrêter le traitement de maintien des fonctions vitales, la prise en charge des derniers moments de la vie et le diagnostic de décès selon des critères cardiocirculatoires doivent être distincts et indépendants des processus de don et transplantation. Ce rapport contient des recommandations destinées aux gestionnaires de program, aux autorités sanitaires régionales et aux instances appelés à élaborer les protocoles de DDC. Les programmes doivent être conçus en fonction des éléments suivants : direction et planification locales, éducation et engagement des intervenants, mécanismes d'assurance de la sécurité et de la qualité et information du public. Il est recommandé de commencer par un program de DDC contrôlé à l'unité de soins intensifs où, après une décision par consentement mutuel de cesser le traitement de maintien des fonctions vitales, la mort est attendue, mais n'est pas survenue, ce qui rend possible des discussions non précipitées sur le consentement. Un don non contrôlé, en cas de décès après un arrêt cardiaque non prévu, doit être envisagé seulement une fois que le program de DDC contrôlé a été établi. Bien qu'il soit recommandé de restreindre le programme initial au don de reins, le don d'autres organes peut aussi être envisagé selon l'expertise régionale en matière de transplantation. Les répercussions d'un DDC, y compris les interventions pratiquées avant et après le décès, sur la famille du donneur, la disponibilité des organes, la fonction du greffon et la survie du receveur doivent être documentées de façon méthodique et examinées.

Atomic structure of a peptide coated gold nanocluster identified using theoretical and experimental studies

NASA Astrophysics Data System (ADS)

Wang, Hui; Li, Xu; Gao, Liang; Zhai, Jiao; Liu, Ru; Gao, Xueyun; Wang, Dongqi; Zhao, Lina

2016-06-01

Peptide coated gold nanoclusters (AuNCs) have a precise molecular formula and atomic structure, which are critical for their unique applications in targeting specific proteins either for protein analysis or drug design. To date, a study of the crystal structure of peptide coated AuNCs is absent primarily due to the difficulty of obtaining their crystalline phases in an experiment. Here we study a typical peptide coated AuNC (Au24Peptide8, Peptide = H2N-CCYKKKKQAGDV-COOH, Anal. Chem., 2015, 87, 2546) to figure out its atomic structure and electronic structure using a theoretical method for the first time. In this work, we identify the explicit configuration of the essential structure of Au24Peptide8, Au24(Cys-Cys)8, using density functional theory (DFT) computations and optical spectroscopic experiments, where Cys denotes cysteine without H bonded to S. As the first multidentate ligand binding AuNC, Au24(Cys-Cys)8 is characterized as a distorted Au13 core with Oh symmetry covered by two Au(Cys-Cys) and three Au3(Cys-Cys)2 staple motifs in its atomic structure. The most stable configuration of Au24(Cys-Cys)8 is confirmed by comparing its UV-vis absorption spectrum from time-dependent density-functional theory (TDDFT) calculations with optical absorption measurements, and these results are consistent with each other. Furthermore, we carry out frontier molecular orbital (FMO) calculations to elucidate that the electronic structure of Au24(Cys-Cys)8 is different from that of Au24(SR)20 as they have a different Au/S ratio, where SR represents alkylthiolate. Importantly, the different ligand coatings, Cys-Cys and SR, in Au24(Cys-Cys)8 and Au24(SR)20 cause the different Au/S ratios in the coated Au24. The reason is that the Au/S ratio is crucial in determining the size of the Au core of the ligand protected AuNC, and the size of the Au core corresponds to a specific electronic structure. By the adjustment of ligand coatings from alkylthiolate to peptide, the Au/S ratio could be controlled to generate different AuNCs with versatile electronic structures, optical properties and reaction stabilities. Therefore, we propose a universal approach to obtain a specific Au/S ratio of ligand coated AuNCs by adjusting the ligand composition, thus controlling the chemicophysical properties of AuNCs with ultimately the same number of Au atoms.Peptide coated gold nanoclusters (AuNCs) have a precise molecular formula and atomic structure, which are critical for their unique applications in targeting specific proteins either for protein analysis or drug design. To date, a study of the crystal structure of peptide coated AuNCs is absent primarily due to the difficulty of obtaining their crystalline phases in an experiment. Here we study a typical peptide coated AuNC (Au24Peptide8, Peptide = H2N-CCYKKKKQAGDV-COOH, Anal. Chem., 2015, 87, 2546) to figure out its atomic structure and electronic structure using a theoretical method for the first time. In this work, we identify the explicit configuration of the essential structure of Au24Peptide8, Au24(Cys-Cys)8, using density functional theory (DFT) computations and optical spectroscopic experiments, where Cys denotes cysteine without H bonded to S. As the first multidentate ligand binding AuNC, Au24(Cys-Cys)8 is characterized as a distorted Au13 core with Oh symmetry covered by two Au(Cys-Cys) and three Au3(Cys-Cys)2 staple motifs in its atomic structure. The most stable configuration of Au24(Cys-Cys)8 is confirmed by comparing its UV-vis absorption spectrum from time-dependent density-functional theory (TDDFT) calculations with optical absorption measurements, and these results are consistent with each other. Furthermore, we carry out frontier molecular orbital (FMO) calculations to elucidate that the electronic structure of Au24(Cys-Cys)8 is different from that of Au24(SR)20 as they have a different Au/S ratio, where SR represents alkylthiolate. Importantly, the different ligand coatings, Cys-Cys and SR, in Au24(Cys-Cys)8 and Au24(SR)20 cause the different Au/S ratios in the coated Au24. The reason is that the Au/S ratio is crucial in determining the size of the Au core of the ligand protected AuNC, and the size of the Au core corresponds to a specific electronic structure. By the adjustment of ligand coatings from alkylthiolate to peptide, the Au/S ratio could be controlled to generate different AuNCs with versatile electronic structures, optical properties and reaction stabilities. Therefore, we propose a universal approach to obtain a specific Au/S ratio of ligand coated AuNCs by adjusting the ligand composition, thus controlling the chemicophysical properties of AuNCs with ultimately the same number of Au atoms. Electronic supplementary information (ESI) available: The MALDI-TOF-MS identification of Au24Peptide8, the structural divisions of Au24(Cys-Cys)8 obtained based on the ``divide and protect'' approach, the structure of level-1 and -3 staple motifs, the relative energies of all stable configurations of Au24(Cys-Cys)8, orbital components of Iso1 of Au24(Cys-Cys)8, electronic structure comparison between Au24(Cys-Cys)8 and Au24(SR)20, and the coordination of Iso1. See DOI: 10.1039/c5nr08727a

Oxygen reduction of several gold alloys in 1-molar potassium hydroxide

NASA Technical Reports Server (NTRS)

Miller, R. O.

1975-01-01

With rotated disk-and-ring equipment, polarograms and other electrochemical measurements were made of oxygen reduction in 1-molar potassium hydroxide on an equiatomic gold-copper (Au-Cu) alloy and a Au-Cu alloy doped with either indium (In) or cobalt (Co) and on Au doped with either nickel (Ni) or platinum (Pt). The results were compared with those for pure Au and pure Pt. The two-electron reaction dominated on all Au alloys as it did on Au. The polarographic results at lower polarization potentials were compared, assuming exclusively a two-step reduction. A qualified ranking of cathodic electrocatalytic activity on the freshly polished reduced disks was indicated: anodized Au Au-Cu-In Au-Cu Au-Cu-Co is equivalent or equal to Au-Pt Au-Ni. Aging in distilled water improved the electrocatalytic efficiency of Au-Cu-Co, Au-Cu, and (to a lesser extent) Au-Cu-In.

Protein coated gold nanoparticles as template for the directed synthesis of highly fluorescent gold nanoclusters

NASA Astrophysics Data System (ADS)

Zhang, Lingyan; Han, Fei

2018-04-01

Bovine serum albumin (BSA) modified gold nanoparticles (AuNPs) was selected as template for the synthesis of AuNPs@gold nanoclusters (AuNCs) core/shell nanoparticles, in which BSA not only acted as dual functions agent for both anchoring and reducing Au3+ ions, but also was employed as a bridge between the AuNPs and AuNCs. Optical properties of AuNPs@AuNCs core/shell nanoparticles were studied using UV-visible and fluorescence spectroscopy. The prepared AuNPs@AuNCs core/shell nanoparticles exhibited sphere size uniformity with improved monodispersity, excellent fluorescence and fluorescent stability. Compared with AuNCs, AuNPs@AuNCs core/shell nanoparticles possessed large size and strong fluorescence intensity due to the effect of AuNPs as core. Moreover, the mechanism of the AuNPs induced fluorescence changes of the core/shell nanoparticles was first explored.

Update on the Risk of Introduction of African Swine Fever by Wild Boar into Disease-Free European Union Countries.

PubMed

Bosch, J; Rodríguez, A; Iglesias, I; Muñoz, M J; Jurado, C; Sánchez-Vizcaíno, J M; de la Torre, A

2017-10-01

Despite efforts to prevent the appearance and spread of African swine fever (ASF) in the European Union, several Member States are now affected (Lithuania, Poland, Latvia and Estonia). Disease appearance in 2014 was associated with multiple entrances linked to wild boar movement from endemic areas (EFSA Journal, 8, 2015, 1556), but the risk of new introductions remains high (Gallardo et al., Porcine Health Management, 1, and 21) as ASF continues to be active in endemic countries (Russian Federation, Belarus and Ukraine). Since 2014, the number of ASF notifications has increased substantially, particularly in wild boar (WB), in parallel with slow but constant geographical advance of the disease. This situation suggests a real risk of further disease spread into other Member States, posing a great threat to pig production in the EU. Following the principles of the risk-based veterinary surveillance, this article applies a methodology developed by De la Torre et al. (Transboundary and Emerging Diseases, 62, and 272) to assess the relative risk of new introductions of ASF by natural movements of WB according to the current epidemiological situation. This update incorporates the most recent available data and an improved version of the most important risk estimator: an optimized cartographic tool of WB distribution to analyse wild boar suitable habitat. The highest relative risk values were estimated for Slovakia (5) and Romania (5), followed by Finland (4), Czech Republic (3) and Germany (3). Relative risk for Romania and Finland is associated mainly with disease entrance from endemic areas such as the Russian Federation and Ukraine, where the disease is currently spreading; relative risk for Germany and Czech Republic is associated mainly with the potential progress of the disease through the EU, and relative risk for Slovakia is associated with both pathways. WB habitat is the most important risk estimator, whereas WB density is the least significant, suggesting that WB presence is more relevant than density. These results can provide actionable advice for dealing with risk. They can be directly used to inform risk-based national strategies and identify countries that may need to pay greater attention to surveillance or conduct additional evaluations at the subnational level. © 2016 Blackwell Verlag GmbH.

Largely enhanced photocatalytic activity of Au/XS2/Au (X = Re, Mo) antenna-reactor hybrids: charge and energy transfer.

PubMed

Chen, Kai; Ding, Si-Jing; Luo, Zhi-Jun; Pan, Gui-Ming; Wang, Jia-Hong; Liu, Jia; Zhou, Li; Wang, Qu-Quan

2018-02-22

An antenna-reactor hybrid coupling plasmonic antenna with catalytic nanoparticles is a new strategy to optimize photocatalytic activity. Herein, we have rationally proposed a Au/XS 2 /Au (X = Re, Mo) antenna reactor, which has a large Au core as the antenna and small satellite Au nanoparticles as the reactor separated by an ultrathin two-dimensional transition-metal dichalcogenide XS 2 shell (∼2.6 nm). Due to efficient charge transfer across the XS 2 shell as well as energy transfer via coupling of the Au antenna and Au reactor, the photocatalytic activity has been largely enhanced: Au/ReS 2 /Au exhibits a 3.59-fold enhancement, whereas Au/MoS 2 /Au exhibits a 2.66-fold enhancement as compared to that of the sum of the three individual components. The different enhancement in the Au/ReS 2 /Au and Au/MoS 2 /Au antenna-reactor hybrid is related to the competition and cooperation of charge and energy transfer. These results indicate the great potential of the Au/XS 2 /Au antenna-reactor hybrid for the development of highly efficient plasmonic photocatalysts.

Agglomeration behavior of lipid-capped gold nanoparticles

NASA Astrophysics Data System (ADS)

Ranjan, Rajeev; Kirillova, Maria A.; Esimbekova, Elena N.; Zharkov, Sergey M.; Kratasyuk, Valentina A.

2018-04-01

The current investigation deciphers aggregation pattern of gold nanoparticles (AuNPs) and lipid-treated AuNPs when subjected to aqueous sodium chloride solution with increasing ionic strengths (100-400 nM). AuNPs were synthesized using 0.29 mM chloroauric acid and by varying the concentrations of trisodium citrate (AuNP1 1.55 mM, AuNP2 3.1 mM) and silver nitrate (AuNP3 5.3 μM, AuNP4 10.6 μM) with characteristic LSPR peaks in the range of 525-533 nm. TEM analysis revealed AuNPs to be predominantly faceted nanocrystals with the average size of AuNP1 to be 35 ± 5 nm, AuNP2 15 ± 5 nm, AuNP3 30 ± 5 nm, and AuNP4 30 ± 5 nm and the zeta-average for AuNPs were calculated to be 31.23, 63.80, 26.08, and 28 nm respectively. Induced aggregation was observed within 10 s in all synthesized AuNPs while lipid-treated AuNP2 (AuNP2-L) was found to withstand ionic interferences at all concentration levels. However, lipid-treated AuNPs synthesized using silver nitrate and 1.55 mM trisodium citrate (AuNP3, AuNP4) showed much lower stability. The zeta potential values of lipid-treated AuNPs (AuNP1-L-1 x/200, - 17.93 ± 1.02 mV; AuNP2-L-1 x/200, - 21.63 ± 0.70; AuNP3-L-1 x/200, - 14.54 ± 0.90; AuNP3-L-1 x/200 - 13.77 ± 0.83) justified these observations. To summarize, AuNP1 and AuNP2 treated with lipid mixture 1 equals or above 1 x/200 or 1 x/1000 respectively showed strong resistance against ionic interferences (up to 400 mM NaCl). Use of lipid mixture 1 for obtaining highly stable AuNPs also provided functional arms of various lengths which can be used for covalent coupling. [Figure not available: see fulltext.

Optical and electrical properties of colloidal (spherical Au)-(spinel ferrite nanorod) heterostructures

NASA Astrophysics Data System (ADS)

George, Chandramohan; Genovese, Alessandro; Qiao, Fen; Korobchevskaya, Kseniya; Comin, Alberto; Falqui, Andrea; Marras, Sergio; Roig, Anna; Zhang, Yang; Krahne, Roman; Manna, Liberato

2011-11-01

We report here a simple synthetic route to Au-FexOy heterostructures in which spinel ferrite (FexOy) grows as a nanorod on a spherical gold (Au) seed. The large red shift in the plasmon resonance in the heterostructures could be explained by a dielectric effect (although we could not entirely exclude a contribution due to electron transfer from Au to defect states at the Au-FexOy interface), while the magnetic properties of the Au-FexOy heterostructures were basically the same as those of the corresponding nanocrystals after Au leaching. In films of Au-FexOy heterostructures the electrical conductivity appeared to be mediated by the Au domains.We report here a simple synthetic route to Au-FexOy heterostructures in which spinel ferrite (FexOy) grows as a nanorod on a spherical gold (Au) seed. The large red shift in the plasmon resonance in the heterostructures could be explained by a dielectric effect (although we could not entirely exclude a contribution due to electron transfer from Au to defect states at the Au-FexOy interface), while the magnetic properties of the Au-FexOy heterostructures were basically the same as those of the corresponding nanocrystals after Au leaching. In films of Au-FexOy heterostructures the electrical conductivity appeared to be mediated by the Au domains. Electronic supplementary information (ESI) available: TEM/HRTEM images of (i) aliquots at the earliest stages of the growth of Au-FexOy HSs; (ii) Au-FexOy HSs synthesized at low DDAB concentrations; (iii) spherical iron oxide nanocrystals synthesized under the same conditions as the HSs, but in the absence of Au seeds; (iv) Au-FexOy urchin like nanostructures, also after attempts to leach out Au; (v) Au-FexOy HSs after treatment with hydrazine; (vi) FexOy HSs after Au leaching from Au-FexOy HSs; additional optical absorption spectra; additional I-V curves, also from films made of Au-FexOy dumbbells; and additional SEM images; vii) X-ray diffraction (XRD) pattern of a sample of Au-FexOy HSs. See DOI: 10.1039/c1nr10768b

Dissolution of first unions in Colombia, Panama, and Peru.

PubMed

Goldman, N

1981-11-01

An analysis of marital histories from World Fertility Survey data in Colombia, Panama, and Peru indicates a high level of union dissolution: the probabilities of a first union ending by separation within twenty years of the onset of union equal .27, .40, and .18 in the three countries respectively. Dissolution probabilities are especially high among women with young ages at first union and among women residing in urban areas. For all subgroups studied, consensual unions are characterized by several times the risk of separation of legal marriages. Consensual unions are especially frequent among women in rural areas, women with little education and women who enter unions at young ages. The different prevalence of consensual unions among the different subgroups affects the associations between union stability and various correlates so that it becomes essential to investigate the factors affecting union stability for both consensual unions and legal marriages. In spite of high dissolution rates, remarriage rates in all three countries are also high, as are the percentages of time spent in a union. Hence, the potential effects of voluntary disruption of unions on fertility appear to be modest.

Effects of antirheumatic gold compounds on the conversion of xanthine dehydrogenase to oxidase in rabbit liver cytosol in vitro.

PubMed

Sakuma, Satoru; Gotoh, Kyohko; Sadatoku, Namiko; Fujita, Tadashi; Fujimoto, Yohko

2004-07-23

Effects of auranofin (AUR), aurothioglucose (AuTG) and aurothiomalate (AuTM) on the conversion of xanthine dehydrogenase (XD) to oxidase (XO) in the cytosolic fraction from rabbit liver were examined. AUR had no effect on the conversion of XD to XO at concentrations up to 50 microM, whereas at concentrations ranging from 10 to 25 microM, AuTG and AuTM induced the conversion of XD to XO. The constituents of AuTG and AuTM, aurous ion (Au+), but not mercaptosuccinic acid and 1-thio-beta-D-glucose, converted XD to XO in a similar degree to AuTG and AuTM. This means that Au (I) moiety has an important role in the AuTG- and AuTM-induced conversion of XD to XO. Furthermore, N-acetyl-L-cysteine (NAC) and British anti-Lewisite (BAL) reconverted AuTG and AuTM-induced XO to XD, implying that clinical activity of NAC and BAL against toxic reactions of AuTG and AuTM is partially due to the XO reconversion. These results suggest that AuTG and AuTM have the potential to convert XD to its reactive oxygen species-generating form, XO, and that this effect may be correlated with cytotoxic actions of these drugs.

How Does Amino Acid Ligand Modulate Au Core Structure and Characteristics in Peptide Coated Au Nanocluster?

PubMed

Li, Nan; Li, Xu; Zhao, Hongkang; Zhao, Lina

2018-03-01

The atomic structures and the corresponding physicochemical properties of peptide coated Au nanoclusters determine their distinctive biological targeting applications. To learn the modulation of amino acid ligand on the atomic structure and electronic characteristics of coated Au core is the fundamental knowledge for peptide coated Au nanocluster design and construction. Based on our recent coated Au nanocluster configuration study (Nanoscale, 2016, 8, 11454), we built the typically simplified Au13(Cys-Au-Cys) system to more clearly learn the basic modulation information of amino acid ligand on Au core by the density functional theory (DFT) calculations. There are two isomers as ligand adjacent bonding (Iso1) and diagonal bonding (Iso2) to Au13 cores. The geometry optimizations indicate the adjacent bonding Iso1 is more stable than Iso2. More important, the Au13 core of Iso1 distorts much more significantly than that of Iso2 by Cys-Au-Cys bonding through the root-mean-square deviation (RMSD) analysis, which modulate their electronic characteristics in different ways. In addition, the frontier molecular orbital results of Au13(Cys-Au-Cys) isomers confirm that the Au cores mainly determine the blue shifts of Au13(Cys-Au-Cys) systems versus the original Au13 core in their UV-visible absorption spectrum studies. The configuration of Au13 core performs deformation under Cys-Au-Cys ligand modulation to reach new stability with distinct atomic structure and electronic properties, which could be the theory basis for peptide coated AuNCs design and construction.

From the ternary Eu(Au/In) 2 and EuAu 4(Au/In) 2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu 5Au 16(Au/In) 6 structure

DOE PAGES

Steinberg, Simon; Card, Nathan; Mudring, Anja -Verena

2015-08-13

The ternary Eu(Au/In) 2 (EuAu 0.46In 1.54 (2)) (I), EuAu 4(Au/In) 2 (EuAu 4+xIn 2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu 2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl 4Mo 2-type (tI14; I4/ mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed ofmore » an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au 8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu 2–“EuAu 4In 2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu 4(Au/In) 2” models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au–In contacts. Furthermore, a chemical bonding analysis on two “EuAu 5In” and “EuAu 4In 2” models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.« less

From the ternary Eu(Au/In) 2 and EuAu 4(Au/In) 2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu 5Au 16(Au/In) 6 structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinberg, Simon; Card, Nathan; Mudring, Anja -Verena

The ternary Eu(Au/In) 2 (EuAu 0.46In 1.54 (2)) (I), EuAu 4(Au/In) 2 (EuAu 4+xIn 2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu 2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl 4Mo 2-type (tI14; I4/ mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed ofmore » an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au 8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu 2–“EuAu 4In 2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu 4(Au/In) 2” models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au–In contacts. Furthermore, a chemical bonding analysis on two “EuAu 5In” and “EuAu 4In 2” models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.« less

75 FR 57820 - National Credit Union Administration Restoration Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-22

... NATIONAL CREDIT UNION ADMINISTRATION National Credit Union Administration Restoration Plan AGENCY: National Credit Union Administration (NCUA). ACTION: Approval of National Credit Union Administration restoration plan. On September 16, 2010, the National Credit Union Administration (NCUA) implemented a...

Size-dependent tuning of horseradish peroxidase bioreactivity by gold nanoparticles

NASA Astrophysics Data System (ADS)

Wu, Haohao; Liu, Yi; Li, Meng; Chong, Yu; Zeng, Mingyong; Lo, Y. Martin; Yin, Jun-Jie

2015-02-01

Molecules with diverse biological functions, such as heme peroxidases, can be useful tools for identifying potential biological effects of gold nanoparticles (AuNPs) at the molecular level. Here, using UV-Vis, circular dichroism, dynamic light scattering, and electron spin resonance spectroscopy, we report tuning of horseradish peroxidase (HRP) bioactivity by reactant-free AuNPs with diameters of 5, 10, 15, 30 and 60 nm (Au-5 nm, Au-10 nm, Au-15 nm, Au-30 nm and Au-60 nm). HRP conjugation to AuNPs was observed with only Au-5 nm and Au-10 nm prominently increasing the α-helicity of the enzyme to extents inversely related to their size. Au-5 nm inhibited both HRP peroxidase activity toward 3,3',5,5'-tetramethylbenzidine and HRP compound I/II reactivity toward 5,5-dimethyl-1-pyrroline N-oxide. Au-5 nm enhanced the HRP peroxidase activity toward ascorbic acid and the HRP compound I/II reactivity toward redox-active residues in the HRP protein moiety. Further, Au-5 nm also decreased the catalase- and oxidase-like activities of HRP. Au-10 nm showed similar, but weaker effects, while Au-15 nm, Au-30 nm and Au-60 nm had no effect. Results suggest that AuNPs can size-dependently enhance or inhibit HRP bioreactivity toward substrates with different redox potentials via a mechanism involving extension of the HRP substrate access channel and decline in the redox potentials of HRP catalytic intermediates.Molecules with diverse biological functions, such as heme peroxidases, can be useful tools for identifying potential biological effects of gold nanoparticles (AuNPs) at the molecular level. Here, using UV-Vis, circular dichroism, dynamic light scattering, and electron spin resonance spectroscopy, we report tuning of horseradish peroxidase (HRP) bioactivity by reactant-free AuNPs with diameters of 5, 10, 15, 30 and 60 nm (Au-5 nm, Au-10 nm, Au-15 nm, Au-30 nm and Au-60 nm). HRP conjugation to AuNPs was observed with only Au-5 nm and Au-10 nm prominently increasing the α-helicity of the enzyme to extents inversely related to their size. Au-5 nm inhibited both HRP peroxidase activity toward 3,3',5,5'-tetramethylbenzidine and HRP compound I/II reactivity toward 5,5-dimethyl-1-pyrroline N-oxide. Au-5 nm enhanced the HRP peroxidase activity toward ascorbic acid and the HRP compound I/II reactivity toward redox-active residues in the HRP protein moiety. Further, Au-5 nm also decreased the catalase- and oxidase-like activities of HRP. Au-10 nm showed similar, but weaker effects, while Au-15 nm, Au-30 nm and Au-60 nm had no effect. Results suggest that AuNPs can size-dependently enhance or inhibit HRP bioreactivity toward substrates with different redox potentials via a mechanism involving extension of the HRP substrate access channel and decline in the redox potentials of HRP catalytic intermediates. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07056a

Callipeltosides A, B and C: Total Syntheses and Structural Confirmation

PubMed Central

Frost, James R; Pearson, Colin M; Snaddon, Thomas N; Booth, Richard A; Turner, Richard M; Gold, Johan; Shaw, David M; Gaunt, Matthew J; Ley, Steven V

2015-01-01

Since their isolation almost 20 years ago, the callipeltosides have been of long standing interest to the synthetic community owing to their unique structural features and inherent biological activity. Herein we present our full research effort that has led to the synthesis of these molecules. Key aspects of our final strategy include 1) synthesis of the C1–C9 pyran core (5) using an AuCl3-catalysed cyclisation; 2) formation of C10–C22 vinyl iodide (55) by sequential bidirectional Stille reactions and 3) diastereoselective union of these advanced fragments by means of an alkenylzinc addition (d.r.=91:9 at C9). The common callipeltoside aglycon (4) was completed in a further five steps. Following this, all three sugar fragments were appended to provide the entire callipeltoside family. In addition to this, D-configured callipeltose B was synthesised and appended to the callipeltoside aglycon. The 1H NMR spectrum of this molecule was found to be significantly different to the natural isolate, further supporting our assignment of callipeltoside B (2). PMID:26230615

Rapport sur l'état du patrimoine astronomique dans les observatoires français de la fin du XIXè siècle

NASA Astrophysics Data System (ADS)

Damm, E.; Pécontal, E.

2012-12-01

Suite au colloque sur la sauvegarde du patrimoine astronomique organisé par le MAEE et la SAF, sous l'égide de l'UNESCO, qui a conduit à l'adoption de la Déclaration de Paris, les directeurs d'observatoires institutionnels qui étaient absents du colloque ont ressenti le besoin de discuter de ces conclusions prises en leur nom. L'initiative d'organiser une réunion des directeurs des Observatoires des Sciences de l'Univers (OSU) à ce sujet le 30 janvier 2012 a été prise par François Vernotte, directeur de l'Observatoire de Besançon. Le présent compte-rendu de visite résulte d'une initiative spontanée d'Emmanuel Pécontal, astronome responsable du Patrimoine à l'observatoire de Lyon, et d'Evelyne Damm, membre de la Commission Nationale de classement des Monuments Historiques (CNMH) et élue à la communauté d'agglomération des Portes de l'Essonne oû est sis l'observatoire de Camille Flammarion.

Evaluation d'impact sur la santé et évaluation d'impact sur l'équité en santé : éventail de pratiques et questions de recherche.

PubMed

Villeval, Mélanie; Bidault, Elsa; Lang, Thierry

2016-09-01

L'Evaluation d'Impact sur la Santé (EIS) se développe au niveau international et est encore au stade émergent en France. Elle vise à évaluer les effets positifs et négatifs potentiels d'un projet, d'un programme ou d'une politique sur la santé. L'objectif est de produire des recommandations en direction des décideurs, afin d'en maximiser les effets positifs et d'en diminuer les effets négatifs. L'EIS est un moyen particulièrement intéressant d'action sur les déterminants de la santé au-delà des comportements individuels et du système de santé. Les politiques de logement, de transport, de solidarité, économiques, etc. ont, en effet, des impacts souvent non prévus sur la santé. Au-delà des effets sur la santé, l'EIS doit aussi permettre d'apprécier la distribution de ces effets dans la population.Si la préoccupation pour l'équité en santé est centrale dans l'EIS, elle reste cependant difficilement traduite en pratique. Face à cette difficulté, des démarches d'évaluation d'impact ont été développées pour renforcer la prise en compte de l'équité à chaque étape de l'EIS ou « Equity Focused Health Impact Assessment », ou prendre en compte les impacts sur les inégalités de santé de façon spécifique. Ainsi, l'Evaluation de l'Impact sur l'Equité en Santé (EIES) semble, par exemple, particulièrement intéressante pour évaluer l'impact sur les inégalités de projets dans le champ sanitaire.L'EIS et l'EIES posent de nombreuses questions de recherche, notamment autour de la réunion, dans une même démarche, du politique, du citoyen et de l'expert. La participation des populations vulnérables potentiellement affectées par la politique évaluée est une valeur centrale de l'EIS, mais pose des questions d'acceptabilité sociale. La collaboration avec les décideurs politiques est également un enjeu majeur. Les difficultés méthodologiques, notamment de quantification des impacts, peuvent constituer des freins à la promotion de la démarche auprès des décideurs. © The Author(s) 2015.

Microstructure and opto-electronic properties of Sn-rich Au-Sn diffusive solders

NASA Astrophysics Data System (ADS)

Rerek, T.; Skowronski, L.; Kobierski, M.; Naparty, M. K.; Derkowska-Zielinska, B.

2018-09-01

Microstructural and opto-electronic properties of Au ⧹ Sn and Sn ⧹ Au bilayers, obtained by sequential evaporating of metals on the Si substrate, were investigated by means of atomic force microscopy, X-ray diffraction and spectroscopic ellipsometry. Thicknesses of individual films were established to obtain the atomic ratio of Au:Sn atoms 1:1, 1:2 and 1:4, which were favor the formation of AuSn, AuSn2 and AuSn4, respectively. However, the produced intermatallic compounds were detected as AuSn and AuSn2. Additionally, the unbounded Sn was found. The sequence of deposition of Au and Sn films as well as their thickness strongly affect on the composition, microstructure, optical and electrical properties of the produced layers. The Au ⧹ Sn (Sn on the top) layers were more smooth than Sn ⧹ Au (Au on the top) films. Generally, the Au ⧹ Sn layers exhibit a better electrical and optical properties than Sn ⧹ Au films. The optical parameters: plasma energy, free-carrier damping, mean relaxation time of conduction electrons and optical resistivity were determined from the effective complex dielectric function of the formed Au, Sn and Au-Sn films. The optical resistivity values are in the range from 17.8 μΩ cm to 85.1 μΩ cm and from 29.6 μΩ cm to 113.3 μΩ cm for Au ⧹ Sn and Sn ⧹ Au layers, respectively.

The rational design of a Au(I) precursor for focused electron beam induced deposition.

PubMed

Marashdeh, Ali; Tiesma, Thiadrik; van Velzen, Niels J C; Harder, Sjoerd; Havenith, Remco W A; De Hosson, Jeff T M; van Dorp, Willem F

2017-01-01

Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition. Aurophilic interactions are found to play a key role. The short lifetime of ClAuCO in vacuum is explained by strong, destabilizing Au-Au interactions in the solid phase. While aurophilic interactions do not affect the stability of ClAuPMe 3 , they leave the complex non-volatile. Comparison of crystal structures of ClAuPMe 3 and MeAuPMe 3 shows that Au-Au interactions are much weaker or partially even absent for the latter structure. This explains its high volatility. However, MeAuPMe 3 dissociates unfavorably during FEBIP, making it an unsuitable precursor. The study shows that Me groups reduce aurophilic interactions, compared to Cl groups, which we attribute to electronic rather than steric effects. Therefore we propose MeAuCO as a potential FEBIP precursor. It is expected to have weak Au-Au interactions, making it volatile. It is stable enough to act as a volatile source for Au deposition, being stabilized by 6.5 kcal/mol. Finally, MeAuCO is likely to dissociate in a single step to pure Au.

Bonding properties of FCC-like Au 44 (SR) 28 clusters from X-ray absorption spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Rui; Chevrier, Daniel M.; Zeng, Chenjie

Thiolate-protected gold clusters with precisely controlled atomic composition have recently emerged as promising candidates for a variety of applications because of their unique optical, electronic, and catalytic properties. The recent discovery of the Au44(SR)28 total structure is considered as an interesting finding in terms of the face-centered cubic (FCC)-like core structure in small gold-thiolate clusters. Herein, the unique bonding properties of Au44(SR)28 is analyzed using temperature-dependent X-ray absorption spectroscopy (XAS) measurements at the Au L3-edge and compared with other FCC-like clusters such as Au36(SR)24 and Au28(SR)20. A negative thermal expansion was detected for the Au–Au bonds of the metal coremore » (the first Au–Au shell) and was interpreted based on the unique Au core structure consisting of the Au4 units. EXAFS fitting results from Au28(SR)20, Au36(SR)24, and Au44(SR)28 show a size-dependent negative thermal expansion behavior in the first Au–Au shell, further highlighting the importance of the Au4 units in determining the Au core bonding properties and shedding light on the growth mechanism of these FCC-like Au clusters.« less

Magnetic susceptibilities of liquid Cr-Au, Mn-Au and Fe-Au alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohno, S.; Shimakura, H.; Tahara, S.

The magnetic susceptibility of liquid Cr-Au, Mn-Au, Fe-Au and Cu-Au alloys was investigated as a function of temperature and composition. Liquid Cr{sub 1-c}Au{sub c} with 0.5 ≤ c and Mn{sub 1-c}Au{sub c} with 0.3≤c obeyed the Curie-Weiss law with regard to their dependence of χ on temperature. The magnetic susceptibilities of liquid Fe-Au alloys also exhibited Curie-Weiss behavior with a reasonable value for the effective number of Bohr magneton. On the Au-rich side, the composition dependence of χ for liquid TM-Au (TM=Cr, Mn, Fe) alloys increased rapidly with increasing TM content, respectively. Additionally, the composition dependences of χ for liquidmore » Cr-Au, Mn-Au, and Fe-Au alloys had maxima at compositions of 50 at% Cr, 70 at% Mn, and 85 at% Fe, respectively. We compared the composition dependences of χ{sub 3d} due to 3d electrons for liquid binary TM-M (M=Au, Al, Si, Sb), and investigated the relationship between χ{sub 3d} and E{sub F} in liquid binary TM-M alloys at a composition of 50 at% TM.« less

Formation, Migration, and Reactivity of Au CO Complexes on Gold Surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jun; McEntee, Monica; Tang, Wenjie

2016-01-12

Here, we report experimental as well as theoretical evidence that suggests Au CO complex formation upon the exposure of CO to active sites (step edges and threading dislocations) on a Au(111) surface. Room-temperature scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy, transmission infrared spectroscopy, and density functional theory calculations point to Au CO complex formation and migration. Room-temperature STM of the Au(111) surface at CO pressures in the range from 10^ 8 to 10^ 4 Torr (dosage up to 10^6 langmuir) indicates Au atom extraction from dislocation sites of the herringbone reconstruction, mobile Au CO complex formation and diffusion, and Aumore » adatom cluster formation on both elbows and step edges on the Au surface. The formation and mobility of the Au CO complex result from the reduced Au Au bonding at elbows and step edges leading to stronger Au CO bonding and to the formation of a more positively charged CO (CO +) on Au. These studies indicate that the mobile Au CO complex is involved in the Au nanoparticle formation and reactivity, and that the positive charge on CO increases due to the stronger adsorption of CO at Au sites with lower coordination numbers.« less

Mechanisms and Factors Associated With Tackle-Related Injuries in South African Youth Rugby Union Players.

PubMed

Burger, Nicholas; Lambert, Mike Ian; Viljoen, Wayne; Brown, James Craig; Readhead, Clint; den Hollander, Steve; Hendricks, Sharief

2017-02-01

The majority of injuries in rugby union occur during tackle events. The mechanisms and causes of these injuries are well established in senior rugby union. To use information from an injury database and assess video footage of tackle-related injuries in youth rugby union matches to identify environmental factors and mechanisms that are potentially confounding to these injuries. Descriptive epidemiological study. Injury surveillance was conducted at the under-18 Craven Week rugby tournament. Tackle-related injury information was used to identify injury events in match video footage (role-matched noninjury tackle events were identified for the cohort of injured players). Events were coded using match situational variables (precontact, contact, and postcontact). Relative risk ratio (RRR; ratio of probability of an injury or noninjury outcome occurring when a characteristic was observed) was reported by use of logistic regression. In comparison with the first quarter, injury risk was greater in the third (RRR = 9.75 [95% CI, 1.71-55.64]; P = .010) and fourth quarters (RRR = 6.97 [95% CI, 1.09-44.57]; P = .040) for ball carriers and in the fourth quarter (RRR = 9.63 [95% CI, 1.94-47.79]; P = .006) for tacklers. Ball carriers were less likely to be injured when they were aware of impending contact (RRR = 0.14 [95% CI, 0.03-0.66]; P = .012) or when they executed a moderate fend (hand-off) (RRR = 0.22 [95% CI, 0.06-0.84]; P = .026). Tacklers were less likely to be injured when performing shoulder tackles (same side as leading leg) in comparison to an arm-only tackle (RRR = 0.02 [95% CI, 0.001-0.79]; P = .037). Ball carriers (RRR = 0.09 [95% CI, 0.01-0.89]; P = .040) and tacklers (RRR = 0.02 [95% CI, 0.001-0.32]; P =.006) were less likely to be injured when initial contact was made with the tackler's shoulder/arm instead of his head/neck. The relative risk of tackle-related injury was higher toward the end of matches. Incorrect technique may contribute to increased injury risk. Implementing recovery strategies between matches, training safe and effective techniques, and improving levels of conditioning may counter the negative effects of fatigue. These findings may assist stakeholders in youth rugby to formulate injury prevention strategies and may improve the preparation of field-side medical staff for managing tackle-related injuries at these or similar tournaments.

A comparative theoretical study of the catalytic activities of Au2(-) and AuAg(-) dimers for CO oxidation.

PubMed

Liu, Peng; Song, Ke; Zhang, Dongju; Liu, Chengbu

2012-05-01

The detailed mechanisms of catalytic CO oxidation over Au(2)(-) and AuAg(-) dimers, which represent the simplest models for monometal Au and bimetallic Au-Ag nanoparticles, have been studied by performing density functional theory calculations. It is found that both Au(2)(-) and AuAg(-) dimers catalyze the reaction according to the similar mono-center Eley-Rideal mechanism. The catalytic reaction is of the multi-channel and multi-step characteristic, which can proceed along four possible pathways via two or three elementary steps. In AuAg(-), the Au site is more active than the Ag site, and the calculated energy barrier values for the rate-determining step of the Au-site catalytic reaction are remarkably smaller than those for both the Ag-site catalytic reaction and the Au(2)(-) catalytic reaction. The better catalytic activity of bimetallic AuAg(-) dimer is attributed to the synergistic effect between Au and Ag atom. The present results provide valuable information for understanding the higher catalytic activity of Au-Ag nanoparticles and nanoalloys for low-temperature CO oxidation than either pure metallic catalyst.

Microstructural and electrical properties of Al/n-type Si Schottky diodes with Au-CuPc nanocomposite films as interlayer

NASA Astrophysics Data System (ADS)

Reddy, P. R. Sekhar; Janardhanam, V.; Jyothi, I.; Chang, Han-Soo; Lee, Sung-Nam; Lee, Myung Sun; Reddy, V. Rajagopal; Choi, Chel-Jong

2017-11-01

Au-CuPc nanocomposite films were prepared by simultaneous evaporation of Au and CuPc with various Au and CuPc concentrations. Microstructural analysis of Au-CuPc films revealed elongated Au cluster formation from isolated Au nanoclusters with increasing Au concentration associated with coalescence of Au clusters. Au-CuPc films with different compositions were employed as interlayer in Al/n-Si Schottky diode. Barrier height and series resistance of the Al/n-Si Schottky diode with Au-CuPc interlayer decreased with increasing Au concentration. This could be associated with the enhancement of electron tunneling between neighboring clusters due to decrease in spacing of Au clusters and formation of conducting paths through the composite material. Interface state density of the Al/n-Si Schottky diode with Au-CuPc interlayer increased with increasing Au concentration. This might be because the inclusion of metal decreases the crystallinity and crystal size of the polymer matrix accompanied by the formation of local defect sites at the places of metal nucleation.

Evidence of final-state suppression of high-p{_ T} hadrons in Au + Au collisions using d + Au measurements at RHIC

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.; Zhang, J.

Transverse momentum spectra of charged hadrons with pT < 6 GeV/c have been measured near mid-rapidity (0.2 < ɛ < 1.4) by the PHOBOS experiment at RHIC in Au + Au and d + Au collisions at {√ {s{NN}} = {200 GeV}}. The spectra for different collision centralities are compared to {p + ¯ {p}} collisions at the same energy. The resulting nuclear modification factor for central Au + Au collisions shows evidence of strong suppression of charged hadrons in the high-pT region (>2 GeV/c). In contrast, the d + Au nuclear modification factor exhibits no suppression of the high-pT yields. These measurements suggest a large energy loss of the high-pT particles in the highly interacting medium created in the central Au + Au collisions. The lack of suppression in d + Au collisions suggests that it is unlikely that initial state effects can explain the suppression in the central Au + Au collisions. PACS: 25.75.-q

Management of tibial non-unions according to a novel treatment algorithm.

PubMed

Ferreira, Nando; Marais, Leonard Charles

2015-12-01

Tibial non-unions represent a spectrum of conditions that are challenging to treat. The optimal management remains unclear despite the frequency with which these diagnoses are encountered. The aim of this study was to determine the outcome of tibial non-unions managed according to a novel tibial non-union treatment algorithm. One hundred and eighteen consecutive patients with 122 uninfected tibial non-unions were treated according to our proposed tibial non-union treatment algorithm. All patients were followed-up clinically and radiologically for a minimum of six months after external fixator removal. Four patients were excluded because they did not complete the intended treatment process. The final study population consisted of 94 men and 24 women with a mean age of 34 years. Sixty-seven non-unions were stiff hypertrophic, 32 mobile atrophic, 16 mobile oligotrophic and one true pseudoarthrosis. Six non-unions were classified as type B1 defect non-unions. Bony union was achieved after the initial surgery in 113/122 (92.6%) tibias. Nine patients had failure of treatment. Seven persistent non-unions were successfully retreated according to the tibial non-union treatment algorithm. This resulted in final bony union in 120/122 (98.3%) tibias. The proposed tibial non-union treatment algorithm appears to produce high union rates across a diverse group of tibial non-unions. Tibial non-unions however, remain difficult to treat and should be referred to specialist units where advanced reconstructive techniques are practiced on a regular basis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Benchmarking Helps Measure Union Programs, Operations.

ERIC Educational Resources Information Center

Mann, Jerry

2001-01-01

Explores three examples of benchmarking by college student unions. Focuses on how a union can collect information from other unions for use as benchmarking standards for the purposes of selling a concept or justifying program increases, or for comparing a union's financial performance to other unions. (EV)

Capacity building in water demand management as a key component for attaining millennium development goals

NASA Astrophysics Data System (ADS)

Gumbo, Bekithemba; Forster, Laura; Arntzen, Jaap

Successful water demand management (WDM) implementation as a component of integrated water resource management (IWRM) can play a significant role in the alleviation of poverty through more efficient use of available water resources. The urban population in Southern African cities is characterised by so-called ‘water poor’ communities who typically expend a high percentage of their household income on poor quality water. Usually they have no access to an affordable alternative source. Although WDM as a component of IWRM is not a panacea for poverty, it can help alleviate poverty by facilitating water services management by municipal water supply agencies (MWSAs) in the region. WDM is a key strategy for achieving the millennium development goals (MDGs) and, as such, should be given due attention in the preparation of national IWRM and water efficiency plans. Various studies in the Southern African region have indicated that capacity building is necessary for nations to develop IWRM and water-use efficiency plans to meet the targets set out in the MDGs. WDM education and training of water professionals and end-users is particularly important in developing countries, which are resource and information-access poor. In response to these findings, The World Conservation Union (IUCN) and its consulting partners, the Training and Instructional Design Academy of South Africa (TIDASA), and Centre for Applied Research (CAR) designed, developed and presented a pilot WDM Guideline Training Module for MWSAs as part of Phase II of IUCN’s Southern Africa regional WDM project. Pilot training was conducted in July 2004 in Lusaka, Zambia for a group of 36 participants involved in municipal water supply from nine Southern African countries. This paper looks at the links between building the capacity of professionals, operational staff and other role-players in the municipal water supply chain to implement WDM as part of broader IWRM strategies, and the subsequent potential for poverty relief resulting from more effective, efficient and equitable use and allocation of municipal water supplies.

Plasmonic enhancement of visible-light water splitting with Au-TiO2 composite aerogels

NASA Astrophysics Data System (ADS)

Desario, Paul A.; Pietron, Jeremy J.; Devantier, Devyn E.; Brintlinger, Todd H.; Stroud, Rhonda M.; Rolison, Debra R.

2013-08-01

We demonstrate plasmonic enhancement of visible-light-driven splitting of water at three-dimensionally (3D) networked gold-titania (Au-TiO2) aerogels. The sol-gel-derived ultraporous composite nanoarchitecture, which contains 1 to 8.5 wt% Au nanoparticles and titania in the anatase form, retains the high surface area and mesoporosity of unmodified TiO2 aerogels and maintains stable dispersion of the ~5 nm Au guests. A broad surface plasmon resonance (SPR) feature centered at ~550 nm is present for the Au-TiO2 aerogels, but not Au-free TiO2 aerogels, and spans a wide range of the visible spectrum. Gold-derived SPR in Au-TiO2 aerogels cast as films on transparent electrodes drives photoelectrochemical oxidation of aqueous hydroxide and extends the photocatalytic activity of TiO2 from the ultraviolet region to visible wavelengths exceeding 700 nm. Films of Au-TiO2 aerogels in which Au nanoparticles are deposited on pre-formed TiO2 aerogels by a deposition-precipitation method (DP Au/TiO2) also photoelectrochemically oxidize aqueous hydroxide, but less efficiently than 3D Au-TiO2, despite having an essentially identical Au nanoparticle weight fraction and size distribution. For example, 3D Au-TiO2 containing 1 wt% Au is as active as DP Au/TiO2 with 4 wt% Au. The higher photocatalytic activity of 3D Au-TiO2 derives only in part from its ability to retain the surface area and porosity of unmodified TiO2 aerogel. The magnitude of improvement indicates that in the 3D arrangement either a more accessible photoelectrochemical reaction interphase (three-phase boundary) exists or more efficient conversion of excited surface plasmons into charge carriers occurs, thereby amplifying reactivity over DP Au/TiO2. The difference in photocatalytic efficiency between the two forms of Au-TiO2 demonstrates the importance of defining the structure of Au||TiO2 interfaces within catalytic Au-TiO2 nanoarchitectures.We demonstrate plasmonic enhancement of visible-light-driven splitting of water at three-dimensionally (3D) networked gold-titania (Au-TiO2) aerogels. The sol-gel-derived ultraporous composite nanoarchitecture, which contains 1 to 8.5 wt% Au nanoparticles and titania in the anatase form, retains the high surface area and mesoporosity of unmodified TiO2 aerogels and maintains stable dispersion of the ~5 nm Au guests. A broad surface plasmon resonance (SPR) feature centered at ~550 nm is present for the Au-TiO2 aerogels, but not Au-free TiO2 aerogels, and spans a wide range of the visible spectrum. Gold-derived SPR in Au-TiO2 aerogels cast as films on transparent electrodes drives photoelectrochemical oxidation of aqueous hydroxide and extends the photocatalytic activity of TiO2 from the ultraviolet region to visible wavelengths exceeding 700 nm. Films of Au-TiO2 aerogels in which Au nanoparticles are deposited on pre-formed TiO2 aerogels by a deposition-precipitation method (DP Au/TiO2) also photoelectrochemically oxidize aqueous hydroxide, but less efficiently than 3D Au-TiO2, despite having an essentially identical Au nanoparticle weight fraction and size distribution. For example, 3D Au-TiO2 containing 1 wt% Au is as active as DP Au/TiO2 with 4 wt% Au. The higher photocatalytic activity of 3D Au-TiO2 derives only in part from its ability to retain the surface area and porosity of unmodified TiO2 aerogel. The magnitude of improvement indicates that in the 3D arrangement either a more accessible photoelectrochemical reaction interphase (three-phase boundary) exists or more efficient conversion of excited surface plasmons into charge carriers occurs, thereby amplifying reactivity over DP Au/TiO2. The difference in photocatalytic efficiency between the two forms of Au-TiO2 demonstrates the importance of defining the structure of Au||TiO2 interfaces within catalytic Au-TiO2 nanoarchitectures. Electronic supplementary information (ESI) available: Nitrogen physisorption isotherms; Au4f X-ray photoelectron spectra; TEM-derived distributions of Au size and aspect ratio; relative IPCE enhancement ratio. See DOI: 10.1039/c3nr01429k

Structure-activity relationships in cytotoxic Au(I)/Au(III) complexes derived from 2-(2'-pyridyl)benzimidazole.

PubMed

Maiore, Laura; Aragoni, Maria Carla; Deiana, Carlo; Cinellu, Maria Agostina; Isaia, Francesco; Lippolis, Vito; Pintus, Anna; Serratrice, Maria; Arca, Massimiliano

2014-04-21

Gold(I) and gold(III) complexes derived from 2-(2'-pyridyl)benzimidazole (pbiH) were proven to be a promising class of in vitro antitumor agents against A2780 human ovarian cancer cells. In this paper, a comparative electrochemical, UV-vis absorption, and emission spectroscopic investigation is reported on pbiH, the two mononuclear Au(III) complexes [(pbi)AuX2] (X = Cl (1), AcO (2)), the four mononuclear Au(I) derivatives [(pbiH)AuCl] (3), [(pbiH)Au(PPh3)]PF6 ((4(+))(PF6(-))), [(pbi)Au(PPh3)] (5), and [(pbi)Au(TPA)] (6), the three mixed-valence Au(III)/Au(I) complexes [(μ-pbi)Au2Cl3] (7), [(Ph3P)Au(μ-pbi)AuX2]PF6 (X = Cl ((8(+))(PF6(-))), AcO ((9(+))(PF6(-)))), and the binuclear Au(I)-Au(I) compound [(μ-pbi)Au2(PPh3)2]PF6 ((10(+))(PF6(-))). All complexes feature irreversible reduction processes related to the Au(III)/Au(I) or Au(I)/Au(0) processes and peculiar luminescent emission at about 360-370 nm in CH2Cl2, with quantum yields that are remarkably lower ((0.7-14.5) × 10(-2)) in comparison to that determined for the free pbiH ligand (31.5 × 10(-2)) in the same solvent. The spectroscopic and electrochemical properties of all complexes were interpreted on the grounds of time-dependent PBE0/DFT calculations carried out both in the gas phase and in CH2Cl2 implicitly considered within the IEF-PCM SCRF approach. The electronic structure of the complexes, and in particular the energy and composition of the Kohn-Sham LUMOs, can be related to the antiproliferative properties against the A2780 ovarian carcinoma cell line, providing sound quantitative structure-activity relationships and shedding a light on the role played by the global charge and nature of ancillary ligands in the effectiveness of Au-based antitumor drugs.

The relationship between labor unions and safety in US airlines: Is there a "union effect?"

NASA Astrophysics Data System (ADS)

Zapf, Renee Catherine

Every airline union claims to work for safety and presents anecdotes where greater airline safety has been achieved through union efforts. The effect unionization has on safety outcomes in U.S. commercial airlines, however, wasn't found to be previously tested. Studies have shown that in industries such as coal mining, retail, and construction, unionization does lead to an increase in safety. This study evaluated the safety rates of 15 major US commercial airlines to compare the difference between unionized and non-unionized airlines. These safety rates were compared based on if and how long each airline's pilots and flight attendants have been unionized, to determine if unionization had an effect on safety outcomes. The 15 airlines included in the study identified as operating most of the years between 1990 and 2013, with annual departures averaging over 130,000, available through the Bureau of Transportation Statistics. Accident and Incident information was acquired through the National Transportation Safety Board database. The number of accident and incidents divided by the total departures at each airline was used as the safety rate. Union websites provided information on unionization at the airlines. Due to the complex nature of the aviation industry, a number of confounding factors could have affected the tests, including mergers, route structures, and legislation. To help control for these confounding factors, this study was limited to airlines with a stable presence in the industry over time, which limited the number of airlines included. No significant difference was found between unionized and non-unionized airlines in this study, though the mean safety rate of unionized airlines was found be better than non-unionized airlines. This study did not take into account safety improvements that were union-backed and eventually required at all airlines, regardless of unionization. Due to the large sample size of the small population the difference in safety rate means could be indicative of greater safety in unionized airlines.

Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamczyk, L.

We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore » rapidity range |y| < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

Suppression of Υ production in d + Au + and Au + Au collisions at √ sNN =200 GeV

DOE PAGES

None

2014-07-01

We report measurements of Upsilon meson production in p + p, d +Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p +p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y|more » < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state part on energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

DOE PAGES

Adamczyk, L.

2015-04-01

We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore » rapidity range |y| < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

Interfacial nanodroplets guided construction of hierarchical Au, Au-Pt, and Au-Pd particles as excellent catalysts

NASA Astrophysics Data System (ADS)

Ma, Aijing; Xu, Jie; Zhang, Xuehua; Zhang, Bin; Wang, Dayang; Xu, Haolan

2014-05-01

Interfacial nanodroplets were grafted to the surfaces of self-sacrificed template particles in a galvanic reaction system to assist the construction of 3D Au porous structures. The interfacial nanodroplets were formed via direct adsorption of surfactant-free emulsions onto the particle surfaces. The interfacial nanodroplets discretely distributed at the template particle surfaces and served as soft templates to guide the formation of porous Au structures. The self-variation of footprint sizes of interfacial nanodroplets during Au growth gave rise to a hierarchical pore size distribution of the obtained Au porous particles. This strategy could be easily extended to synthesize bimetal porous particles such as Au-Pt and Au-Pd. The obtained porous Au, Au-Pt, and Au-Pd particles showed excellent catalytic activity in catalytic reduction of 4-nitrophenol.

12 CFR 704.11 - Corporate Credit Union Service Organizations (Corporate CUSOs).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 7 2012-01-01 2012-01-01 false Corporate Credit Union Service Organizations (Corporate CUSOs). 704.11 Section 704.11 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS CORPORATE CREDIT UNIONS § 704.11 Corporate Credit Union Service Organizations...

12 CFR 704.11 - Corporate Credit Union Service Organizations (Corporate CUSOs).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 7 2014-01-01 2014-01-01 false Corporate Credit Union Service Organizations (Corporate CUSOs). 704.11 Section 704.11 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS CORPORATE CREDIT UNIONS § 704.11 Corporate Credit Union Service Organizations...

12 CFR 704.11 - Corporate Credit Union Service Organizations (Corporate CUSOs).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 7 2013-01-01 2013-01-01 false Corporate Credit Union Service Organizations (Corporate CUSOs). 704.11 Section 704.11 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS CORPORATE CREDIT UNIONS § 704.11 Corporate Credit Union Service Organizations...

Progressive biogeochemical transformation of placer gold particles drives compositional changes in associated biofilm communities.

PubMed

Rea, Maria Angelica; Standish, Christopher D; Shuster, Jeremiah; Bissett, Andrew; Reith, Frank

2018-05-03

Biofilms on placer gold (Au)-particle surfaces drive Au solubilization and re-concentration thereby progressively transforming the particles. Gold solubilization induces Au-toxicity; however, Au-detoxifying community members ameliorates Au-toxicity by precipitating soluble Au to metallic Au. We hypothesize that Au-dissolution and re-concentration (precipitation) places selective pressures on associated microbial communities, leading to compositional changes and subsequent Au-particle transformation. We analyzed Au-particles from eight United Kingdom sites using next generation sequencing, electron microscopy and micro-analyses. Gold particles contained biofilms composed of prokaryotic cells and extracellular polymeric substances intermixed with (bio)minerals. Across all sites communities were dominated by Proteobacteria (689, 97% Operational Taxonomic Units, 59.3% of total reads), with β-Proteobacteria being the most abundant. A wide range of Au-morphotypes including nanoparticles, micro-crystals, sheet-like Au and secondary rims, indicated that dissolution and re-precipitation occurred, and from this transformation indices were calculated. Multivariate statistical analyses showed a significant relationship between the extent of Au-particle transformation and biofilm community composition, with putative metal-resistant Au-cycling taxa linked to progressive Au transformation. These included the genera Pseudomonas, Leptothrix and Acinetobacter. Additionally, putative exoelectrogenic genera Rhodoferax and Geobacter were highly abundant. In conclusion, biogeochemical Au-cycling and Au-particle transformation occurred at all sites and exerted a strong influence on biofilm community composition.

Coprecipitation of gold(III) complex ions with manganese(II) hydroxide and their stoichiometric reduction to atomic gold (Au(0)): analysis by Mössbauer spectroscopy and XPS.

PubMed

Yamashita, Mamiko; Ohashi, Hironori; Kobayashi, Yasuhiro; Okaue, Yoshihiro; Kurisaki, Tsutomu; Wakita, Hisanobu; Yokoyama, Takushi

2008-03-01

To elucidate the formation process of precursor of gold-supported manganese dioxide (MnO2), the coprecipitation behavior of [AuCl4-n(OH)n](-) (n=0-4) (Au(III)) complex ions with manganese(II) hydroxide (Mn(OH)2 and the change in their chemical state were examined. The Au(III) complex ions were rapidly and effectively coprecipitated with Mn(OH)(2) at pH 9. According to the Mössbauer spectra for gold (Au) coprecipitated with Mn(OH)2, below an Au content of 60 wt% in the coprecipitates, all of the coprecipitated Au existed in the atomic state (Au(0)), while, above an Au content of 65 wt%, part of the gold existed in the Au(III) state, and the proportion increased with increasing coprecipitated Au content. Based on the results of X-ray photoelectron spectroscopy, Mn(II) in Mn(OH)2 converted to Mn(IV) in conjunction with coprecipitation of Au(III) complex ions. These results indicate that the rapid stoichiometric reduction of Au(III) to Au(0) is caused by electron transfer from Mn(II) in Mn(OH)2 to the Au(III) complex ion through an Mn-O-Au bond.

Internal-Modified Dithiol DNA-Directed Au Nanoassemblies: Geometrically Controlled Self-Assembly and Quantitative Surface-Enhanced Raman Scattering Properties

NASA Astrophysics Data System (ADS)

Yan, Yuan; Shan, Hangyong; Li, Min; Chen, Shu; Liu, Jianyu; Cheng, Yanfang; Ye, Cui; Yang, Zhilin; Lai, Xuandi; Hu, Jianqiang

2015-11-01

In this work, a hierarchical DNA-directed self-assembly strategy to construct structure-controlled Au nanoassemblies (NAs) has been demonstrated by conjugating Au nanoparticles (NPs) with internal-modified dithiol single-strand DNA (ssDNA) (Au-B-A or A-B-Au-B-A). It is found that the dithiol-ssDNA-modified Au NPs and molecule quantity of thiol-modified ssDNA grafted to Au NPs play critical roles in the assembly of geometrically controlled Au NAs. Through matching Au-DNA self-assembly units, geometrical structures of the Au NAs can be tailored from one-dimensional (1D) to quasi-2D and 2D. Au-B-A conjugates readily give 1D and quasi-2D Au NAs while 2D Au NAs can be formed by A-B-Au-B-A building blocks. Surface-enhanced Raman scattering (SERS) measurements and 3D finite-difference time domain (3D-FDTD) calculation results indicate that the geometrically controllable Au NAs have regular and linearly “hot spots”-number-depended SERS properties. For a certain number of NPs, the number of “hot spots” and accordingly enhancement factor of Au NAs can be quantitatively evaluated, which open a new avenue for quantitative analysis based on SERS technique.

Isomorphism and solid solutions among Ag- and Au-selenides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palyanova, Galina A.; Seryotkin, Yurii V.; Novosibirsk State University

Au-Ag selenides were synthesized by heating stoichiometric mixtures of elementary substances of initial compositions Ag{sub 2−x}Au{sub x}Se with a step of x=0.25 (0≤x≤2) to 1050 °C and annealing at 500 °C. Scanning electron microscopy, optical microscopy, electron microprobe analysis and X-ray powder diffraction methods have been applied to study synthesized samples. Results of studies of synthesized products revealed the existence of three solid solutions with limited isomorphism Ag↔Au: naumannite Ag{sub 2}Se – Ag{sub 1.94}Au{sub 0.06}Se, fischesserite Ag{sub 3}AuSe{sub 2} - Ag{sub 3.2}Au{sub 0.8}Se{sub 2} and gold selenide AuSe - Au{sub 0.94}Ag{sub 0.06}Se. Solid solutions and AgAuSe phases were added tomore » the phase diagram of Ag-Au-Se system. Crystal-chemical interpretation of Ag-Au isomorphism in selenides was made on the basis of structural features of fischesserite, naumannite, and AuSe. - Highlights: • Au-Ag selenides were synthesized. • Limited Ag-Au isomorphism in the selenides is affected by structural features. • Some new phases were introduced to the phase diagram Ag-Au-Se.« less

A remote-controlled generation of gold@polydopamine (core@shell) nanoparticles via physical-chemical stimuli of polydopamine/gold composites

NASA Astrophysics Data System (ADS)

Lee, Yi Seul; Bae, Ji Young; Koo, Hye Young; Lee, Young Boo; Choi, Won San

2016-03-01

We present the synthesis of polydopamine particle-gold composites (PdopP-Au) and unique release of Au@Pdop core@shell nanoparticles (NPs) from the PdopP-Au upon external stimuli. The PdopP-Au was prepared by controlled synthesis of AuNPs on the Pdop particles. Upon near infrared (NIR) irradiation or NaBH4 treatment on the PdopP-Au, the synthesized AuNPs within the PdopPs could be burst-released as a form of Au@Pdop NPs. The PdopP-Au composite showed outstanding photothermal conversion ability under NIR irradiation due to the ultrahigh loading of the AuNPs within the PdopPs, leading to a remote-controlled explosion of the PdopP-Au and rapid formation of numerous Au@Pdop NPs. The release of the Au@Pdop NPs could be instantly stopped or re-started by off or reboot of NIR, respectively. The structure of the released Au@Pdop NPs is suitable for a catalyst or adsorbent, thus we demonstrated that the PdopP-Au composite exhibited excellent and sustained performances for environmental remediation due to its capability of the continuous production of fresh catalysts or adsorbents during the reuse.

The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits

NASA Astrophysics Data System (ADS)

Deditius, Artur P.; Reich, Martin; Kesler, Stephen E.; Utsunomiya, Satoshi; Chryssoulis, Stephen L.; Walshe, John; Ewing, Rodney C.

2014-09-01

The ubiquity of Au-bearing arsenian pyrite in hydrothermal ore deposits suggests that the coupled geochemical behaviour of Au and As in this sulfide occurs under a wide range of physico-chemical conditions. Despite significant advances in the last 20 years, fundamental factors controlling Au and As ratios in pyrite from ore deposits remain poorly known. Here we explore these constraints using new and previously published EMPA, LA-ICP-MS, SIMS, and μ-PIXE analyses of As and Au in pyrite from Carlin-type Au, epithermal Au, porphyry Cu, Cu-Au, and orogenic Au deposits, volcanogenic massive sulfide (VHMS), Witwatersrand Au, iron oxide copper gold (IOCG), and coal deposits. Pyrite included in the data compilation formed under temperatures from ∼30 to ∼600 °C and in a wide variety of geological environments. The pyrite Au-As data form a wedge-shaped zone in compositional space, and the fact that most data points plot below the solid solubility limit defined by Reich et al. (2005) indicate that Au1+ is the dominant form of Au in arsenian pyrite and that Au-bearing ore fluids that deposit this sulfide are mostly undersaturated with respect to native Au. The analytical data also show that the solid solubility limit of Au in arsenian pyrite defined by an Au/As ratio of 0.02 is independent of the geochemical environment of pyrite formation and rather depends on the crystal-chemical properties of pyrite and post-depositional alteration. Compilation of Au-As concentrations and formation temperatures for pyrite indicates that Au and As solubility in pyrite is retrograde; Au and As contents decrease as a function of increasing temperature from ∼200 to ∼500 °C. Based on these results, two major Au-As trends for Au-bearing arsenian pyrite from ore deposits are defined. One trend is formed by pyrites from Carlin-type and orogenic Au deposits where compositions are largely controlled by fluid-rock interactions and/or can be highly perturbed by changes in temperature and alteration by hydrothermal fluids. The second trend consists of pyrites from porphyry Cu and epithermal Au deposits, which are characterised by compositions that preserve the Au/As signature of mineralizing magmatic-hydrothermal fluids, confirming the role of this sulfide in controlling metal ratios in ore systems.

Tackle technique and tackle-related injuries in high-level South African Rugby Union under-18 players: real-match video analysis.

PubMed

Burger, Nicholas; Lambert, Michael I; Viljoen, Wayne; Brown, James C; Readhead, Clint; Hendricks, Sharief

2016-08-01

The high injury rate associated with rugby union is primarily due to the tackle, and poor contact technique has been identified as a risk factor for injury. We aimed to determine whether the tackle technique proficiency scores were different in injurious tackles versus tackles that did not result in injury using real-match scenarios in high-level youth rugby union. Injury surveillance was conducted at the under-18 Craven Week tournaments (2011-2013). Tackle-related injury information was used to identify injury events in the match video footage and non-injury events were identified for the injured player cohort. Injury and non-injury events were scored for technique proficiency and Cohen's effect sizes were calculated and the Student t test (p<0.05) was performed to compare injury versus non-injury scores. The overall mean score for front-on ball-carrier proficiency was 7.17±1.90 and 9.02±2.15 for injury and non-injury tackle events, respectively (effect size=moderate; p<0.05). The overall mean score for side/behind ball-carrier proficiency was 4.09±2.12 and 7.68±1.72 for injury and non-injury tackle events, respectively (effect size=large; p<0.01). The overall mean score for front-on tackler proficiency was 7.00±1.95 and 9.35±2.56 for injury and non-injury tackle events, respectively (effect size=moderate; p<0.05). The overall mean score for side/behind tackler proficiency was 5.47±1.60 and 8.14±1.75 for injury and non-injury tackle events, respectively (effect size=large; p<0.01). Higher overall mean and criterion-specific tackle-related technique scores were associated with a non-injury outcome. The ability to perform well during tackle events may decrease the risk of injury and may manifest in superior performance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Electronic behaviour of Au-Pt alloys and the 4f binding energy shift anomaly in Au bimetallics- X-ray spectroscopy studies

NASA Astrophysics Data System (ADS)

Wang, Dongniu; Cui, Xiaoyu; Xiao, Qunfeng; Hu, Yongfeng; Wang, Zhiqiang; Yiu, Y. M.; Sham, T. K.

2018-06-01

The electronic structure and charge redistribution of 6s conduction charge and 5d charge in Au and Pt alloys, Au9Pt and AuPt9 have been investigated using a charge compensation model. It is found that, both the Au and Pt 4f binding energy (BE) exhibits a negative shift in the alloys relatively to the pure metal in apparent disagreement with electroneutrality considerations (Au is the most electronegative metallic element); more interestingly, the negative Au 4f BE shift in Au-Pt alloy is in contrast to previous observations for a large number of Au bimetallic systems with more electropositive hosts in which the more electropositive the host„ the more positive the Au 4f BE shift. This anomaly is counter intuitive to electronegativity considerations. This dilemma was resolved by the charge compensation model in which both electronegativity and charge neutrality can be satisfied and the overall charge flow δ, onto Au is small and positive and δ arises from charge flow of 6s conduction charge, Δnc onto Au site, which is partially compensated by the depletion of 6d charge Δnd at the Au site (δ = Δnc+ Δnd ˜0.1 >0). The much larger Coulomb interaction between 4f and 5d than that between 4f and 6s results in positive 4f BE shifts. The Au 4f BE shift in Au-Pt alloys together with 193Au Mössbauer data were used in the charge compensation model analysis which shows that the model is still valid in that the Au 4f shift in Au-Pt alloy arises from mainly conduction charge gain with little depletion of d charge at the Au site. The model also works for Pt. The Au and Pt 5d character in the alloys have been examined with valence band spectra which show both maintain their d characteristic in dilute alloys with Pt d piling up at the Fermi level, and the top of the Au valence band being pushed toward the Fermi level; this is confirmed with DFT densities of state calculations. When Pt is diluted in Au, it gains d charge as evident from the reduction in whiteline intensity at the Pt L3-edge XANES. What emerges from this work is a picture in which the s-d charge compensation in Au bimetallic alloys is triggered by electronegativity difference between Au and the host. For Au-Pt and Au-Pd systems, the difference in electronegativity is very small, conduction charge transfer dominates, and the Au 4f shift is negative whereas in most Au bimetallics, the larger the electronegativity difference, the larger the compensation and the larger the Au 4f shifts.

Biosynthesis and stabilization of Au and Au Ag alloy nanoparticles by fungus, Fusarium semitectum

NASA Astrophysics Data System (ADS)

Dasaratrao Sawle, Balaji; Salimath, Basavaraja; Deshpande, Raghunandan; Dhondojirao Bedre, Mahesh; Krishnamurthy Prabhakar, Belawadi; Venkataraman, Abbaraju

2008-09-01

Crystallized and spherical-shaped Au and Au-Ag alloy nanoparticles have been synthesized and stabilized using a fungus, F . semitectum in an aqueous system. Aqueous solutions of chloroaurate ions for Au and chloroaurate and Ag+ ions (1 : 1 ratio) for Au-Ag alloy were treated with an extracellular filtrate of F . semitectum biomass for the formation of Au nanoparticles (AuNP) and Au-Ag alloy nanoparticles (Au-AgNP). Analysis of the feasibility of the biosynthesized nanoparticles and core-shell alloy nanoparticles from fungal strains is particularly significant. The resultant colloidal suspensions are highly stable for many weeks. The obtained Au and Au-Ag alloy nanoparticles were characterized by the surface plasmon resonance (SPR) peaks using a UV-vis spectrophotometer, and the structure, morphology and size were determined by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and transmission electron microscopy (TEM). Possible optoelectronics and medical applications of these nanoparticles are envisaged.

Structural, electronic and magnetic properties of Au-based monolayer derivatives in honeycomb structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kapoor, Pooja, E-mail: pupooja16@gmail.com; Sharma, Munish; Ahluwalia, P. K.

2016-05-23

We present electronic properties of atomic layer of Au, Au{sub 2}-N, Au{sub 2}-O and Au{sub 2}-F in graphene-like structure within the framework of density functional theory (DFT). The lattice constant of derived monolayers are found to be higher than the pristine Au monolayer. Au monolayer is metallic in nature with quantum ballistic conductance calculated as 4G{sub 0}. Similarly, Au{sub 2}-N and Au{sub 2}-F monolayers show 4G{sub 0} and 2G{sub 0} quantum conductance respectively while semiconducting nature with calculated band gap of 0.28 eV has been observed for Au{sub 2}-O monolayer. Most interestingly, half metalicity has been predicted for Au{sub 2}-Nmore » and Au{sub 2}-F monolayers. Our findings may have importance for the application of these monolayers in nanoelectronic and spintronics.« less

Synthesis of NiAu alloy and core-shell nanoparticles in water-in-oil microemulsions

NASA Astrophysics Data System (ADS)

Chiu, Hsin-Kai; Chiang, I.-Chen; Chen, Dong-Hwang

2009-07-01

NiAu alloy nanoparticles with various Ni/Au molar ratios were synthesized by the hydrazine reduction of nickel chloride and hydrogen tetrachloroaurate in the microemulsion system. They had a face-centered cubic structure and a mean diameter of 6-13 nm, decreasing with increasing Au content. As Au nanoparticles did, they showed a characteristic absorption peak at about 520 nm but the intensity decreased with increasing Ni content. Also, they were nearly superparamagnetic, although the magnetization decreased significantly with increasing Au content. Under an external magnetic field, they could be self-organized into the parallel lines. In addition, the core-shell nanoparticles, Ni3Au1@Au, were prepared by the Au coating on the surface of Ni3Au1 alloy nanoparticles. By increasing the hydrogen tetrachloroaurate concentration for Au coating, the thickness of Au shells could be raised and led to an enhanced and red-shifted surface plasmon absorption.

12 CFR 701.19 - Benefits for employees of Federal credit unions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Benefits for employees of Federal credit unions... CREDIT UNIONS ORGANIZATION AND OPERATION OF FEDERAL CREDIT UNIONS § 701.19 Benefits for employees of Federal credit unions. (a) General authority. A federal credit union may provide employee benefits...

12 CFR 704.3 - Corporate credit union capital.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Corporate credit union capital. 704.3 Section... CORPORATE CREDIT UNIONS § 704.3 Corporate credit union capital. (a) Capital plan. A corporate credit union... activities, and the periodic review and reassessment of the capital position of the corporate credit union...

PLANNING AND OPERATING COLLEGE UNION BUILDINGS.

ERIC Educational Resources Information Center

BUTTS, PORTER

THIS MONOGRAPH IS A DISCUSSION OF FOUR ASPECTS OF STUDENT UNIONS. PART ONE DISCUSSES THE NATURE AND PURPOSE OF A UNION AND THE UNION AS A CAMPUS CENTER. PART TWO DEALS WITH THE PLANNING OF UNION BUILDINGS AND GIVES PROCEDURES, PRINCIPLES AND CAUTIONS. UNION FACILITIES AND SERVICES ARE LISTED. PART THREE DISCUSSES THE ORGANIZATION AND ACTIVITIES OF…

Plasmon-enhanced versatile optical nonlinearities in a Au-Ag-Au multi-segmental hybrid structure.

PubMed

Yao, Lin-Hua; Zhang, Jun-Pei; Dai, Hong-Wei; Wang, Ming-Shan; Zhang, Lu-Man; Wang, Xia; Han, Jun-Bo

2018-06-27

A Au-Ag-Au multi-segmental hybrid structure has been synthesized by using an electrodeposition method based on an anodic aluminum oxide (AAO) membrane. The third-order optical nonlinearities, second harmonic generation (SHG) and photoluminescence (PL) properties containing ultrafast supercontinuum generation and plasmon mediated thermal emission have been investigated. Significant optical enhancements have been obtained near surface plasmon resonance wavelength in all the abovementioned nonlinear processes. Comparative studies between the Au-Ag-Au multi-segmental hybrid structure and the corresponding single-component Au and Ag hybrid structures demonstrate that the Au-Ag-Au multi-segmental hybrid structure has much larger optical nonlinearities than its counterparts. These results demonstrate that the Au-Ag-Au hybrid structure is a promising candidate for applications in plasmonic devices and enhancement substrates.

An X-ray Absorption Fine Structure study of Au adsorbed onto the non-metabolizing cells of two soil bacterial species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Zhen; Kenney, Janice P.L.; Fein, Jeremy B.

2015-02-09

Gram-positive and Gram-negative bacterial cells can remove Au from Au(III)-chloride solutions, and the extent of removal is strongly pH dependent. In order to determine the removal mechanisms, X-ray Absorption Fine Structure (XAFS) spectroscopy experiments were conducted on non-metabolizing biomass of Bacillus subtilis and Pseudomonas putida with fixed Au(III) concentrations over a range of bacterial concentrations and pH values. X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) data on both bacterial species indicate that more than 90% of the Au atoms on the bacterial cell walls were reduced to Au(I). In contrast to what has beenmore » observed for Au(III) interaction with metabolizing bacterial cells, no Au(0) or Au-Au nearest neighbors were observed in our experimental systems. All of the removed Au was present as adsorbed bacterial surface complexes. For both species, the XAFS data suggest that although Au-chloride-hydroxide aqueous complexes dominate the speciation of Au in solution, Au on the bacterial cell wall is characterized predominantly by binding of Au atoms to sulfhydryl functional groups and amine and/or carboxyl functional groups, and the relative importance of the sulfhydryl groups increases with increasing pH and with decreasing Au loading. The XAFS data for both microorganism species suggest that adsorption is the first step in the formation of Au nanoparticles by bacteria, and the results enhance our ability to account for the behavior of Au in bacteria-bearing geologic systems.« less

An X-ray Absorption Fine Structure study of Au adsorbed onto the non-metabolizing cells of two soil bacterial species

NASA Astrophysics Data System (ADS)

Song, Zhen; Kenney, Janice P. L.; Fein, Jeremy B.; Bunker, Bruce A.

2012-06-01

Gram-positive and Gram-negative bacterial cells can remove Au from Au(III)-chloride solutions, and the extent of removal is strongly pH dependent. In order to determine the removal mechanisms, X-ray Absorption Fine Structure (XAFS) spectroscopy experiments were conducted on non-metabolizing biomass of Bacillus subtilis and Pseudomonas putida with fixed Au(III) concentrations over a range of bacterial concentrations and pH values. X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) data on both bacterial species indicate that more than 90% of the Au atoms on the bacterial cell walls were reduced to Au(I). In contrast to what has been observed for Au(III) interaction with metabolizing bacterial cells, no Au(0) or Au-Au nearest neighbors were observed in our experimental systems. All of the removed Au was present as adsorbed bacterial surface complexes. For both species, the XAFS data suggest that although Au-chloride-hydroxide aqueous complexes dominate the speciation of Au in solution, Au on the bacterial cell wall is characterized predominantly by binding of Au atoms to sulfhydryl functional groups and amine and/or carboxyl functional groups, and the relative importance of the sulfhydryl groups increases with increasing pH and with decreasing Au loading. The XAFS data for both microorganism species suggest that adsorption is the first step in the formation of Au nanoparticles by bacteria, and the results enhance our ability to account for the behavior of Au in bacteria-bearing geologic systems.

Enhanced electrocatalytic activity of the Au-electrodeposited Pt nanoparticles-coated conducting oxide for the quantum dot-sensitized solar cells

NASA Astrophysics Data System (ADS)

Yoon, Yeung-Pil; Kim, Jae-Hong; Kang, Soon-Hyung; Kim, Hyunsoo; Choi, Chel-Jong; Kim, Kyong-Kook; Ahn, Kwang-Soon

2014-08-01

Au was electrodeposited potentiostatically at 0.3 V for 5 min on nanoporous Pt nanoparticle-coated F-doped SnO2 (FTO/Pt) substrates. For comparison, Au-electrodeposited FTO (FTO/Au) and Au-uncoated FTO/Pt were prepared. FTO/Au showed large-sized Au clusters dispersed sparsely over FTO, which resulted in lower electrocatalytic activity than FTO/Pt. In contrast, FTO/Pt exhibited poor stability unlike FTO/Au due to poisoning by the adsorption of sulfur species. The Au-electrodeposited FTO/Pt (FTO/Pt/Au) consisted of small Au clusters deposited over the entire area of Pt due to the effective Au nucleation provided by nanoporous metallic Pt. FTO/Pt/Au exhibited enhanced electrocatalytic activity and excellent stability because the small Au particles well-dispersed over the nanoporous metallic Pt network provided numerous electrochemical reaction sites, and the Pt surface was not exposed to the electrolyte. When FTO/Pt/Au was used as the counter electrode (CE) of a quantum dot-sensitized solar cell, the significantly enhanced electrocatalytic activity of the FTO/Pt/Au CE facilitated the reduction reaction of Sn2- + 2e- (CE) → Sn-12- + S2- at the CE/electrolyte interface, resulting in a significantly hindered recombination reaction, Sn2- + 2e- (TiO2 in the photoanode) → Sn-12- + S2-, and significantly improved overall energy conversion efficiency.

DOE Office of Scientific and Technical Information (OSTI.GOV)

León, Iker; ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels; Ruipérez, Fernando

We report a joint photoelectron spectroscopy and theoretical study on AuC{sub 4}{sup −}, AuC{sub 6}{sup −}, and AuC{sub n}H{sup −} (n = 2, 4, and 6) using high-resolution photoelectron imaging and ab initio calculations. The ground state of AuC{sub 2}H{sup −}, AuC{sub 4}H{sup −}, and AuC{sub 6}H{sup −} is found to be linear, while that of AuC{sub 4}{sup −} and AuC{sub 6}{sup −} is bent. All the species are found to be linear in their neutral ground states. The electron affinities (EAs) are measured to be 3.366(1) and 3.593(1) eV for AuC{sub 4} and AuC{sub 6}, respectively. Both bending andmore » stretching frequencies are resolved in the spectra of AuC{sub 4}{sup −} and AuC{sub 6}{sup −}. High-resolution data of AuC{sub n}H{sup −} reveal major vibrational progressions in the Au—C stretching and bending modes. AuC{sub 2}H{sup −} has a ground state stretching frequency of 445(10) cm{sup −1} and a bending frequency of 260(10) cm{sup −1}; AuC{sub 4}H{sup −} has a ground state stretching frequency of 340(10) cm{sup −1}; AuC{sub 6}H{sup −} has a ground state stretching frequency of 260(10) cm{sup −1} and a bending frequency of 55(10) cm{sup −1}. The EAs are measured to be 1.475(1), 1.778(1), and 1.962(1) eV for AuC{sub 2}H, AuC{sub 4}H, and AuC{sub 6}H, respectively. The strength of the Au—C bond decreases as the number of carbon atoms increases. The current study provides a wealth of electronic structure information about AuC{sub 4}{sup −}, AuC{sub 6}{sup −}, and AuC{sub n}H{sup −} (n = 2, 4, and 6) and their corresponding neutrals.« less

Atomic and electronic structures of Si(1 1 1)-(√3 x √3)R30°-Au and (6 × 6)-Au surfaces.

PubMed

Patterson, C H

2015-12-02

Si(1 1 1)-Au surfaces with around one monolayer of Au exhibit many ordered structures and structures containing disordered domain walls. Hybrid density functional theory (DFT) calculations presented here reveal the origin of these complex structures and tendency to form domain walls. The conjugate honeycomb chain trimer (CHCT) structure of the [Formula: see text]-Au phase contains Si atoms with non-bonding surface states which can bind Au atoms in pairs in interstices of the CHCT structure and make this surface metallic. Si adatoms adsorbed on the [Formula: see text]-Au surface induce a gapped surface through interaction with the non-bonding states. Adsorption of extra Au atoms in interstitial sites of the [Formula: see text]-Au surface is stabilized by interaction with the non-bonding orbitals and leads to higher coverage ordered structures including the [Formula: see text]-Au phase. Extra Au atoms bound in interstitial sites of the [Formula: see text]-Au surface result in top layer Si atoms with an SiAu4 butterfly wing configuration. The structure of a [Formula: see text]-Au phase, whose in-plane top atomic layer positions were previously determined by an electron holography technique (Grozea et al 1998 Surf. Sci. 418 32), is calculated using total energy minimization. The Patterson function for this structure is calculated and is in good agreement with data from an in-plane x-ray diffraction study (Dornisch et al 1991 Phys. Rev. B 44 11221). Filled and empty state scanning tunneling microscopy (STM) images are calculated for domain walls and the [Formula: see text]-Au structure. The [Formula: see text]-Au phase is 2D chiral and this is evident in computed and actual STM images. [Formula: see text]-Au and domain wall structures contain the SiAu4 motif with a butterfly wing shape. Chemical bonding within the Si-Au top layers of the [Formula: see text]-Au and [Formula: see text]-Au surfaces is analyzed and an explanation for the SiAu4 motif structure is given.

12 CFR 702.302 - Net worth categories for new credit unions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Net worth categories for new credit unions. 702.302 Section 702.302 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS PROMPT CORRECTIVE ACTION Alternative Prompt Corrective Action for New Credit Unions § 702.302 Net worth categories for new credit unions....

Influence of Au and TiO2 structures on hydrogen dissociation over TiO2/Au(100)

NASA Astrophysics Data System (ADS)

Nakamura, I.; Mantoku, H.; Furukawa, T.; Takahashi, A.; Fujitani, T.

2012-11-01

We performed H2-D2 exchange reactions over TiOx/Au(100) and compared the observed reaction kinetics with those reported for TiOx/Au(111) in order to clarify the influence of the Au and TiO2 structures on dissociation of H2 molecules. Low energy electron diffraction observations showed that the TiO2 produced on Au(100) was disordered, in contrast to the comparatively ordered TiO2 structure formed on Au(111). The activation energies and the turnover frequencies for HD formation over TiO2/Au(100) agreed well with those for TiO2/Au(111), clearly indicating that the hydrogen dissociation sites created over TiO2/Au(100) were the perimeter interface between stoichiometric TiO2 and Au, as was previously concluded for TiO2/Au(111). We concluded that the creation of active sites for hydrogen dissociation was independent of the Au and TiO2 structures consisting perimeter interface, and that local bonds that formed between Au and O atoms of stoichiometric TiO2 were essential for the creation of active sites.

Synthesis and electrocatalytic activity of Au/Pt bimetallic nanodendrites for ethanol oxidation in alkaline medium.

PubMed

Han, Xinyi; Wang, Dawei; Liu, Dong; Huang, Jianshe; You, Tianyan

2012-02-01

Gold/Platinum (Au/Pt) bimetallic nanodendrites were successfully synthesized through seeded growth method using preformed Au nanodendrites as seeds and ascorbic acid as reductant. Cyclic voltammograms (CVs) of a series of Au/Pt nanodendrites modified electrodes in 1M KOH solution containing 1M ethanol showed that the electrocatalyst with a molar ratio (Au:Pt) of 3 exhibited the highest peak current density and the lowest onset potential. The peak current density of ethanol electro-oxidation on the Au(3)Pt(1) nanodendrites modified glassy carbon electrode (Au(3)Pt(1) electrode) is about 16, 12.5, and 4.5 times higher than those on the polycrystalline Pt electrode, polycrystalline Au electrode, and Au nanodendrites modified glassy carbon electrode (Au dendrites electrode), respectively. The oxidation peak potential of ethanol electro-oxidation on the Au(3)Pt(1) electrode is about 299 and 276 mV lower than those on the polycrystalline Au electrode and Au dendrites electrode, respectively. These results demonstrated that the Au/Pt bimetallic nanodendrites may find potential application in alkaline direct ethanol fuel cells (ADEFCs). Copyright © 2011 Elsevier Inc. All rights reserved.

Comparison of the space-time extent of the emission source in d +Au and Au + Au collisions at √{sNN} = 200 GeV

NASA Astrophysics Data System (ADS)

Ajitanand, N. N.; Phenix Collaboration

2014-11-01

Two-pion interferometry measurements in d +Au and Au + Au collisions at √{sNN} = 200 GeV are used to extract and compare the Gaussian source radii Rout, Rside and Rlong, which characterize the space-time extent of the emission sources. The comparisons, which are performed as a function of collision centrality and the mean transverse momentum for pion pairs, indicate strikingly similar patterns for the d +Au and Au + Au systems. They also indicate a linear dependence of Rside on the initial transverse geometric size R bar , as well as a smaller freeze-out size for the d +Au system. These patterns point to the important role of final-state re-scattering effects in the reaction dynamics of d +Au collisions.

Properties of Au/Copper oxide nanocomposite prepared by green laser irradiation of the mixture of individual suspensions

NASA Astrophysics Data System (ADS)

Aazadfar, Parvaneh; Solati, Elmira; Dorranian, Davoud

2018-04-01

The fundamental wavelength of a Q-switched pulsed Nd:YAG laser was employed to produce Au and copper oxide nanoparticles via pulsed laser ablation method in water. Different volumetric ratio of nanoparticles were mixed and irradiated by the second harmonic pulses of the Nd:YAG laser to prepare Au/Copper oxide nanocomposite. The experimental investigation was dedicated to study the properties of Au/Copper oxide nanocomposite as a function of volumetric ratio of Au nanoparticles and copper oxide nanoparticles. Nanocomposites of Au and copper oxide were found almost spherical in shape. Adhesion of spherical nanostructure in Au/Copper oxide nanocomposites was decreased with increasing the concentration of Au nanoparticles. Crystalline phase of the Au/Copper oxide nanocomposites differs with the change in the volumetric ratio of Au and copper oxide nanoparticles. The intensity of surface plasmon resonance of Au nanoparticles was decreased after irradiation. Au/Copper oxide nanocomposites suspensions have emissions in the visible range. Results reveal that green laser irradiation of nanoparticle suspensions is an appropriate method to synthesize Au based nanocomposites with controlled composition and size.

eGY-Africa: Addressing the Digital Divide for Science in Africa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barton, C.E.; /Australian Natl. U., Canberra; Amory-Mazaudier, C.

Adoption of information and communication technologies and access to the Internet is expanding in Africa, but because of the rapid growth elsewhere, a Digital Divide between Africa and the rest of the world exists, and the gap is growing. In many sub-Saharan African countries, education and research sector suffers some of the worst deficiencies in access to the Internet, despite progress in development of NRENs - National Research and Education (cyber) Networks. By contrast, it is widely acknowledged in policy statements from the African Union, the UN, and others that strength in this very sector provides the key to meetingmore » and sustaining Millennium Development Goals. Developed countries with effective cyber-capabilities proclaim the benefits to rich and poor alike arising from the Information Revolution. This is but a dream for many scientists in African institutions. As the world of science becomes increasingly Internet-dependent, so they become increasingly isolated. eGY-Africa is a bottom-up initiative by African scientists and their collaborators to try to reduce this Digital Divide by a campaign of advocacy for better institutional facilities. Four approaches are being taken. The present status of Internet services, problems, and plans are being mapped via a combination of direct measurement of Internet performance (the PingER Project) and a questionnaire-based survey. Information is being gathered on policy statements and initiatives aimed at reducing the Digital Divide, which can be used for arguing the case for better Internet facilities. Groups of concerned scientists are being formed at the national, regional levels in Africa, building on existing networks as much as possible. Opinion in the international science community is being mobilized. Finally, and perhaps most important of all, eGY-Africa is seeking to engage with the many other programs, initiatives, and bodies that share the goal of reducing the Digital Divide - either as a direct policy objective, or indirectly as a means to an end, such as the development of an indigenous capability in science and technology for national development. The expectation is that informed opinion from the scientific community at the institutional, national, and international levels can be used to influence the decision makers and donors who are in a position to deliver better Internet capabilities.« less

eGY-Africa: Addressing the Digital Divide for Science in Africa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barton, C. E.

Adoption of information and communication technologies and access to the Internet is expanding in Africa, but because of the rapid growth elsewhere, a Digital Divide between Africa and the rest of the world exists, and the gap is growing. In many sub-Saharan African countries, education and research sector suffer some of the worst deficiencies in access to the Internet, despite progress in development of NRENs National Research and Education (cyber) Networks. By contrast, it is widely acknowledged in policy statements from the African Union, the UN, and others that strength in this very sector provides the key to meeting andmore » sustaining Millennium Development Goals. Developed countries with effective cyber-capabilities proclaim the benefits to rich and poor alike arising from the Information Revolution. This is but a dream for many scientists in African institutions. As the world of science becomes increasingly Internet-dependent, so they become increasingly isolated. eGY-Africa is a bottom-up initiative by African scientists and their collaborators to try to reduce this Digital Divide by a campaign of advocacy for better institutional facilities. Four approaches are being taken. The present status of Internet services, problems, and plans are being mapped via a combination of direct measurement of Internet performance (the PingER Project) and a questionnaire-based survey. Information is being gathered on policy statements and initiatives aimed at reducing the Digital Divide, which can be used for arguing the case for better Internet facilities. Groups of concerned scientists are being formed at the national, regional levels in Africa, building on existing networks as much as possible. Opinion in the international science community is being mobilized. Finally, and perhaps most important of all, eGY-Africa is seeking to engage with the many other programs, initiatives, and bodies that share the goal of reducing the Digital Divide either as a direct policy objective, or indirectly as a means to an end, such as the development of an indigenous capability in science and technology for national development. The expectation is that informed opinion from the scientific community at the institutional, national, and international levels can be used to influence the decision makers and donors who are in a position to deliver better Internet capabilities.« less

eGY-Africa: addressing the digital divide for science in Africa

NASA Astrophysics Data System (ADS)

Baki, Paul; Nguno, Anna; Barton, Charles; Amaeshi, Larry; Tenthani, Chifundo; Petitdidier, Monique; Cottrell, Les

2013-04-01

Adoption of information and communication technologies and access to the Internet is expanding in Africa, but because of the rapid growth elsewhere, a Digital Divide between Africa and the rest of the world exists. In many sub-Saharan African countries, education and research sector suffers some of the worst deficiencies in access to the Internet, despite progress in the development of NRENs - National Research and Education (cyber) Networks. By contrast, it is widely acknowledged in policy statements from the African Union, the UN, and others that strength in this very sector provides the key to meeting and sustaining Millennium Development Goals. Developed countries with effective cyber-capabilities proclaim the benefits to rich and poor alike arising from the Information Revolution. This is still a dream for many scientists in African institutions. As the world of science becomes increasingly Internet-dependent, so they become increasingly isolated. eGY-Africa is a bottom-up initiative by African scientists and their collaborators to try to reduce this digital divide by a campaign of advocacy for better institutional facilities. Four approaches are being taken. The present status of Internet services, problems, and plans are being mapped via a combination of direct measurement of Internet performance (the PingER Project) and a questionnaire-based survey. Information is being gathered on policy statements and initiatives aimed at reducing the digital divide, which can be used for arguing the case for better Internet facilities. Groups of concerned scientists are being formed at the national, regional levels in Africa, building on existing networks as much as possible. Opinion in the international science community is being mobilized. Finally, and perhaps most important of all, eGY-Africa is seeking to engage with the many other programs, initiatives, and bodies that share the goal of reducing the digital divide - either as a direct policy objective, or indirectly as a means to an end, such as the development of an indigenous capability in science and technology for national development. The expectation is that informed opinion from the scientific community at the institutional, national, and international levels can be used to influence the decision makers and donors who are in a position to deliver better Internet capabilities. eGYAfrica workshops have been held approximately bi annually, the last of which was in Nairobi Kenya.

A theoretical study on the electronic structure of Au-XO(0,-1,+1) (X=C, N, and O) complexes: effect of an external electric field.

PubMed

Tielens, Frederik; Gracia, Lourdes; Polo, Victor; Andrés, Juan

2007-12-20

A theoretical study on the nature of Au-XO(0,-1,+1) (X=C, N, O) interaction is carried out in order to provide a better understanding on the adsorption process of XO molecules on Au surfaces or Au-supported surfaces. The effect of the total charge as well as the presence of an external electric field on the formation processes of the Au-XO complex are analyzed and discussed using DFT (B3LYP) and high-level ab initio (CCSD(T)//MP2) methods employing a 6-311+G(3df) basis set for X and O atoms and Stuttgart pseudopotentials for Au atom. The presence of an electric field can increase the binding of O2 molecule to Au while weakening the formation of the Au-CO complex. These behaviors are discussed in the context of adsorption or deadsorption of these molecules on Au clusters. The formation of the Au-XO complex, the effect of addition/removal of one electron, and the role of the electric field are rationalized by studying the nature of the bonding interactions by means of the electron localization function (ELF) analysis. The net interaction between Au and XO fragments is governed by the interplay of three factors: (i) the amount of charge transfer from Au to XO, (ii) the sharing of the lone pair from X atom by the Au core (V(X, Au) basin), and (iii) the role of the lone pair of Au (V(Au) basin) mainly formed by 6s electrons. The total charge of the system and the applied electric field determine the population and orientation of the V(Au) basin and, subsequently, the degree of repulsion with the V(X, Au) basin.

Facile preparation of SERS and catalytically active Au nanostructures using furfuryl derivatives

NASA Astrophysics Data System (ADS)

Kim, Ki-Jung; Kim, Hyun-Chul; Park, Minsun; Huh, Seong

2017-08-01

Six different types of Au nanostructures with rough surfaces were readily prepared through the redox reactions between Au precursor, AuCl4-, and furfuryl derivatives without extra metal surface capping ligands, in deionized water at room temperature. Furfuryl alcohol (FA) or furfurylamine (FFA) was used as a sole reducing agent for the reduction of Au precursor. Both FA and FFA effectively polymerized during the redox reactions to form polyfuran polymers. These polymers are thought to act as surface capping ligands during the formation of Au nanostructures. Experiments were conducted with three different concentrations of each furfuryl derivative. Interestingly, Au particles prepared from the reaction with varying concentration of FA or FFA showed large differences in size, and revealed that the higher the ratios of [FA]/[AuCl4-] or [FFA]/[AuCl4-], the smaller the size of Au particles. The size of Au particles was in the range of 1 μm to under 30 nm. Among these samples, two nanostructured Au particles, AuFA-4 and AuFFA-1, deposited on a Si wafer by a simple drop-casting method, were revealed as highly active surface-enhanced Raman scattering (SERS) substrates for the detection of methylene blue (MB) and crystal violet (CV). High SERS enhancement factors (EFs) of 106 ∼ 108 for MB and CV were observed. Small size Au nanoparticles (AuFFA-2 and AuFFA-4) were also found to be very active for the catalytic hydrogenation of 4-nitrophenol to 4-aminophenol in the presence of NaBH4 at room temperature. AuFFA-2 could be recycled eight times, without losing its activity.

X-ray Absorption Spectroscopy Combined with Time-Dependent Density Functional Theory Elucidates Differential Substitution Pathways of Au(I) and Au(III) with Zinc Fingers.

PubMed

Abbehausen, Camilla; de Paiva, Raphael Enoque Ferraz; Bjornsson, Ragnar; Gomes, Saulo Quintana; Du, Zhifeng; Corbi, Pedro Paulo; Lima, Frederico Alves; Farrell, Nicholas

2018-01-02

A combination of two elements' (Au, Zn) X-ray absorption spectroscopy (XAS) and time-dependent density functional theory (TD-DFT) allowed the elucidation of differential substitution pathways of Au(I) and Au(III) compounds reacting with biologically relevant zinc fingers (ZnFs). Gold L 3 -edge XAS probed the interaction of gold and the C-terminal Cys 2 HisCys finger of the HIV-1 nucleocapsid protein NCp7, and the Cys 2 His 2 human transcription factor Sp1. The use of model compounds helped assign oxidation states and the identity of the gold-bound ligands. The computational studies accurately reproduced the experimental XAS spectra and allowed the proposition of structural models for the interaction products at early time points. The direct electrophilic attack on the ZnF by the highly thiophilic Au(I) resulted in a linear P-Au-Cys coordination sphere after zinc ejection whereas for the Sp1, loss of PEt 3 results in linear Cys-Au-Cys or Cys-Au-His arrangements. Reactions with Au(III) compounds, on the other hand, showed multiple binding modes. Prompt reaction between [AuCl(dien)] 2+ and [Au(dien)(DMAP)] 3+ with Sp1 showed a partially reduced Au center and a final linear His-Au-His coordination. Differently, in the presence of NCp7, [AuCl(dien)] 2+ readily reduces to Au(I) and changes from square-planar to linear geometry with Cys-Au-His coordination, while [Au(dien)(DMAP)] 3+ initially maintains its Au(III) oxidation state and square-planar geometry and the same first coordination sphere. The latter is the first observation of a "noncovalent" interaction of a Au(III) complex with a zinc finger and confirms early hypotheses that stabilization of Au(III) occurs with N-donor ligands. Modification of the zinc coordination sphere, suggesting full or partial zinc ejection, is observed in all cases, and for [Au(dien)(DMAP)] 3+ this represents a novel mechanism for nucleocapsid inactivation. The combination of XAS and TD-DFT presents the first direct experimental observation that not only compound reactivity, but also ZnF core specificity, can be modulated on the basis of the coordination sphere of Au(III) compounds.

Gold(I) Complexes with N-Donor Ligands. 2.(1) Reactions of Ammonium Salts with [Au(acac-kappaC(2))(PR(3))] To Give [Au(NH(3))L](+), [(AuL)(2)(&mgr;(2)-NH(2))](+), [(AuL)(4)(&mgr;(4)-N)](+), or [(AuL)(3)(&mgr;(3)-O)](+). A New and Facile Synthesis of [Au(NH(3))(2)](+) Salts. Crystal Structure of [{AuP(C(6)H(4)OMe-4)(3)}(3)(&mgr;(3)-O)]CF(3)SO(3).

PubMed

Vicente, José; Chicote, María-Teresa; Guerrero, Rita; Jones, Peter G.; Ramírez De Arellano, M. Carmen

1997-09-24

The complexes [Au(acac-kappaC(2))(PR(3))] (acac = acetylacetonate, R = Ph, C(6)H(4)OMe-4) react with (NH(4))ClO(4) to give amminegold(I), [Au(NH(3))(PR(3))]ClO(4), amidogold(I), [(AuPR(3))(2)(&mgr;(2)-NH(2))]ClO(4), or nitridogold(I), [(AuPR(3))(4)(&mgr;(4)-N)]ClO(4), complexes, depending on the reaction conditions. Similarly, [Au(acac-kappaC(2))(PPh(3))] reacts with (NH(3)R')OTf (OTf = CF(3)SO(3)) (1:1) or with [H(3)N(CH(2))(2)NH(2)]OTf (1:1) to give (amine)gold(I) complexes [Au(NH(2)R')(PPh(3))]OTf (R' = Me, C(6)H(4)NO(2)-4) or [(AuPPh(3))(2){&mgr;(2)-H(2)N(CH(2))(2)NH(2)}](OTf)(2), respectively. The ammonium salts (NH(2)R'(2))OTf (R' = Et, Ph) react with [Au(acac-kappaC(2))(PR(3))] (R = Ph, C(6)H(4)OMe-4) (1:2) to give, after hydrolysis, the oxonium salts [(AuPR(3))(3)(&mgr;(3)-O)]OTf (R = Ph, C(6)H(4)OMe-4). When NH(3) is bubbled through a solution of [AuCl(tht)] (tht = tetrahydrothiophene), the complex [Au(NH(3))(2)]Cl precipitates. Addition of [Au(NH(3))(2)]Cl to a solution of AgClO(4) or TlOTf leads to the isolation of [Au(NH(3))(2)]ClO(4) or [Au(NH(3))(2)]OTf, respectively. The crystal structure of [(AuPR(3))(3)(&mgr;(3)-O)]OTf.Me(2)CO (R = C(6)H(4)OMe-4) has been determined: triclinic, space group P&onemacr;, a = 14.884(3) Å, b = 15.828(3) Å, c = 16.061(3) Å, alpha = 83.39(3) degrees, beta = 86.28(3) degrees, gamma = 65.54(3) degrees, R1 (wR2) = 0.0370 (0.0788). The [(AuPR(3))(3)(&mgr;(3)-O)](+) cation shows an essentially trigonal pyramidal array of three gold atoms and one oxygen atom with O-Au-P bond angles of ca. 175 degrees and Au.Au contacts in the range 2.9585(7)-3.0505(14) Å. These cations are linked into centrosymmetric dimers through two short Au.Au [2.9585(7), 3.0919(9) Å] contacts. The gold atoms of the dimer form a six-membered ring with a chair conformation.

Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV.

PubMed

Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Corral, M M; Cramer, J G; Crawford, H J; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Magestro, D; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

2003-02-28

Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

Prevalence of and interest in unionization among staff pharmacists.

PubMed

Zgarrick, David P; McHugh, Patrick P; Droege, Marcus

2006-09-01

Although the propensity for staff pharmacists to join a labor union has never been high, conditions in the profession and workplace have changed over the last decade. Some of these changes may result in staff pharmacists joining a labor union, as well as increased interest in staff pharmacists who are currently not union members to join. The objectives of this study were to (1) assess the degree of union membership among staff pharmacists in 6 states, (2) compare the practice settings, work activities and conditions, compensation, and demographic characteristics between union and nonunion staff pharmacists, (3) assess the level of interest in joining a union among nonunion staff pharmacists, and (4) compare the practice settings, work activities and working conditions, wages and benefits, and demographic characteristics between nonunion staff pharmacists interested in joining a union and nonunion staff pharmacists who were not interested in joining a union. A biennial pharmacist compensation study was conducted in 6 states (Florida, Iowa, Illinois, Minnesota, Tennessee, Wisconsin) in late 2003. Randomly selected pharmacists were mailed a self-administered questionnaire asking about their practice setting, work activities and conditions, wages and benefits, and demographic characteristics. Respondents were also asked to indicate current membership in a union and, if not a member, their desire to unionize their workplace. Compensation and unionization data were provided by 2,180 respondents (27% usable response rate), of which 1,226 (56%) were staff pharmacists. Eight percent of the staff pharmacists were union members, whereas 18% of nonunion members would vote to unionize their workplace. There were few statistically significant differences between union and nonunion staff pharmacists regarding work activities, working conditions, and hourly wages. However, the benefits provided to union staff pharmacists differed from those provided to nonunion staff pharmacists in several ways. Union staff pharmacists were younger than their nonunion counterparts (40.9 vs 44.5 years, P=.01), yet had worked for their current employers a longer time (11.1 vs 7.3 years, P=.03). Nonunion staff pharmacists interested in joining a union differed from those who would not by practice location and setting, working conditions, and benefits. Although the union membership rate among staff pharmacists is relatively low, there are geographic and practice areas where membership rates are higher. Differences in work activities, working conditions, wages, and benefits were noted between union and nonunion staff pharmacists as well as between those who would join a union and those who would not. These differences merit further investigation, especially with respect to evaluating the effectiveness of unions and identifying factors that may lead nonunionized staff pharmacists to join a union.

Ethanol electrooxidation in alkaline medium on electrochemically synthesized Co(OH)2/Au composite

NASA Astrophysics Data System (ADS)

Babu, Sreejith P.; Elumalai, Perumal

2017-01-01

Gold (Au), cobalt hydroxide (Co(OH)2) and different Co(OH)2/Au compositions were electro-deposited onto stainless steel by a potentiodynamic method from the respective metal-ion solutions. The deposits were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transformed infra-red spectroscopy (FT-IR). The XRD and IR data confirmed that the deposits were Au, α-Co(OH)2 or Co(OH)2/Au composites. The SEM observations confirmed that the morphology of the Au was spherical, while the α-Co(OH)2 was flakey with pores. The morphology of the Co(OH)2/Au composites consisted of highly agglomerated Au grains distributed on the Co(OH)2 matrix. The electrocatalytic activity of each of the Au, Co(OH)2 and Co(OH)2/Au-composite electrodes towards ethanol electrooxidation in an alkaline medium was investigated by cyclic voltammetry and chronoamperometry. It turned out that the Co(OH)2/Au-composite electrodes exhibited superior catalytic activity for ethanol electrooxidation compared with the pristine Au or Co(OH)2 electrodes. A peak current density as high as 25 mA cm-2 was exhibited by the Co(OH)2/ Au composite while the Au and Co(OH)2 showed only 0.9 and 13 mA cm-2, respectively. The enhanced conductivity of the Co(OH)2/Au matrix due to the presence of Au, as well as the combined catalytic activity, seemed to be responsible for the superior performance of the Co(OH)2/Au-composite electrodes.

Efficient electrocatalytic conversion of CO.sub.2 to CO using ligand-protected Au.sub.25 clusters

DOEpatents

Kauffman, Douglas; Matranga, Christopher; Qian, Huifeng; Jin, Rongchao; Alfonso, Dominic R.

2015-09-22

An apparatus and method for CO.sub.2 reduction using an Au.sub.25 electrode. The Au.sub.25 electrode is comprised of ligand-protected Au.sub.25 having a structure comprising an icosahedral core of 13 atoms surrounded by a shell of six semi-ring structures bonded to the core of 13 atoms, where each semi-ring structure is typically --SR--Au--SR--Au--SR or --SeR--Au--SeR--Au--SeR. The 12 semi-ring gold atoms within the six semi-ring structures are stellated on 12 of the 20 faces of the icosahedron of the Au.sub.13 core, and organic ligand --SR or --SeR groups are bonded to the Au.sub.13 core with sulfur or selenium atoms. The Au.sub.25 electrode and a counter-electrode are in contact with an electrolyte comprising CO.sub.2 and H+, and a potential of at least -0.1 volts is applied from the Au.sub.25 electrode to the counter-electrode.

Toward hybrid Au nanorods @ M (Au, Ag, Pd and Pt) core-shell heterostructures for ultrasensitive SERS probes

NASA Astrophysics Data System (ADS)

Xie, Xiaobin; Gao, Guanhui; Kang, Shendong; Lei, Yanhua; Pan, Zhengyin; Shibayama, Tamaki; Cai, Lintao

2017-06-01

Being able to precisely control the morphologies of noble metallic nanostructures is of essential significance for promoting the surface-enhanced Raman scattering (SERS) effect. Herein, we demonstrate an overgrowth strategy for synthesizing Au @ M (M = Au, Ag, Pd, Pt) core-shell heterogeneous nanocrystals with an orientated structural evolution and highly improved properties by using Au nanorods as seeds. With the same reaction condition system applied, we obtain four well-designed heterostructures with diverse shapes, including Au concave nanocuboids (Au CNs), Au @ Ag crystalizing face central cube nanopeanuts, Au @ Pd porous nanocuboids and Au @ Pt nanotrepangs. Subsequently, the exact overgrowth mechanism of the above heterostructural building blocks is further analysed via the systematic optimiziation of a series of fabrications. Remarkably, the well-defined Au CNs and Au @ Ag nanopeanuts both exhibit highly promoted SERS activity. We expect to be able to supply a facile strategy for the fabrication of multimetallic heterogeneous nanostructures, exploring the high SERS effect and catalytic activities.

Isomorphism and solid solutions among Ag- and Au-selenides

NASA Astrophysics Data System (ADS)

Palyanova, Galina A.; Seryotkin, Yurii V.; Kokh, Konstantin A.; Bakakin, Vladimir V.

2016-09-01

Au-Ag selenides were synthesized by heating stoichiometric mixtures of elementary substances of initial compositions Ag2-xAuxSe with a step of х=0.25 (0≤х≤2) to 1050 °С and annealing at 500 °C. Scanning electron microscopy, optical microscopy, electron microprobe analysis and X-ray powder diffraction methods have been applied to study synthesized samples. Results of studies of synthesized products revealed the existence of three solid solutions with limited isomorphism Ag↔Au: naumannite Ag2Se - Ag1.94Au0.06Se, fischesserite Ag3AuSe2 - Ag3.2Au0.8Se2 and gold selenide AuSe - Au0.94Ag0.06Se. Solid solutions and AgAuSe phases were added to the phase diagram of Ag-Au-Se system. Crystal-chemical interpretation of Ag-Au isomorphism in selenides was made on the basis of structural features of fischesserite, naumannite, and AuSe.

Coherent tropical-subtropical Holocene see-saw moisture patterns in the Eastern Hemisphere monsoon systems

NASA Astrophysics Data System (ADS)

Wang, Yongbo; Bekeschus, Benjamin; Handorf, Dörthe; Liu, Xingqi; Dallmeyer, Anne; Herzschuh, Ulrike

2017-08-01

The concept of a Global Monsoon (GM) has been proposed based on modern precipitation observations, but its application over a wide range of temporal scales is still under debate. Here, we present a synthesis of 268 continental paleo-moisture records collected from monsoonal systems in the Eastern Hemisphere, including the East Asian Monsoon (EAsM), the Indian Monsoon (IM), the East African Monsoon (EAfM), and the Australian Monsoon (AuM) covering the last 18,000 years. The overall pattern of late Glacial to Holocene moisture change is consistent with those inferred from ice cores and marine records. With respect to the last 10,000 years (10 ka), i.e. a period that has high spatial coverage, a Fuzzy c-Means clustering analysis of the moisture index records together with ;Xie-Beni; index reveals four clusters of our data set. The paleoclimatic meaning of each cluster is interpreted considering the temporal evolution and spatial distribution patterns. The major trend in the tropical AuM, EAfM, and IM regions is a gradual decrease in moisture conditions since the early Holocene. Moisture changes in the EAsM regions show maximum index values between 8 and 6 ka. However, records located in nearby subtropical areas, i.e. in regions not influenced by the intertropical convergence zone, show an opposite trend compared to the tropical monsoon regions (AuM, EAfM and IM), i.e. a gradual increase. Analyses of modern meteorological data reveal the same spatial patterns as in the paleoclimate records such that, in times of overall monsoon strengthening, lower precipitation rates are observed in the nearby subtropical areas. We explain this pattern as the effect of a strong monsoon circulation suppressing air uplift in nearby subtropical areas, and hence hindering precipitation. By analogy to the modern system, this would mean that during the early Holocene strong monsoon period, the intensified ascending airflows within the monsoon domains led to relatively weaker ascending or even descending airflows in the adjacent subtropical regions, resulting in a precipitation deficit compared to the late Holocene. Our conceptual model therefore integrates regionally contrasting moisture changes into the Global Monsoon hypothesis.

Exploration of gold occurrences in alteration zones at Dungash district, Southeastern Desert of Egypt using ASTER data and geochemical analyses

NASA Astrophysics Data System (ADS)

Salem, S. M.; El Sharkawi, M.; El-Alfy, Z.; Soliman, N. M.; Ahmed, S. E.

2016-05-01

The present study aims at exploration of new gold occurrences in the alteration zones at Dungash district. Processed ASTER images band ratios 7/6 × 4/6 and (7 + 9/8), field geology and mineralogical and geochemical data help characterize three types of alterations in three areas 1 to 3 that may be targeted for Au exploration. Area1 confined to the metavolcanics located in the SE of Dungash gold mine and revealed silicified and sericitized type alterations, composed of quartz, epidote, chlorite, biotite and opaque minerals mainly pyrite and chalcopyrite. Area2 occurs in the gabbro-diorite rocks at Abu Meraiwa area NE of Dungash gold mine, which are rich in kaolinite, illite, sericite, pyrite, arsenopyrite and chalcopyrite that record kaolinitized alteration. Area3 is hosted in carbonaceous listwaenized serpentinite thus indicating the role of listwaenitization type alteration in ore genesis. It is composed of calcite, chromite, pyrite, arsenopyrite, chalcopyrite and Ni-bearing sulphides. Au contents in area 1 range between 0.12 and 14.91 ppm, and between 6.1 and 16.3 ppm in area 2, while gold values in area 3 vary from <0.01 to 0.03 ppm. Dungash district is comprised of Pan-African assemblages of ophiolitic ultramafics thrusted over the island arc metavolcanics of dacitic- andesite composition. Gabbro-diorite rocks are intruded in the ultramafics and the acidic metavolcanics as well as diorite-quartz diorite suite intruded in the intermediate metavolcanics. Several acidic dykes, granitic dykes and quartz veins cut through the different rocks types.

Au plasmonics in a WS{sub 2}-Au-CuInS{sub 2} photocatalyst for significantly enhanced hydrogen generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Zhongzhou; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083; Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn

2015-11-30

Promoting the activities of photocatalysts is still the critical challenge in H{sub 2} generation area. Here, a Au plasmon enhanced photocatalyst of WS{sub 2}-Au-CuInS{sub 2} is developed by inserting Au nanoparticles between WS{sub 2} nanotubes and CuInS{sub 2} (CIS) nanoparticles. Due to the localized surface plasmonic resonance properties from Au nanoparticles, WS{sub 2}-Au-CIS shows the best performance as compared to Au-CIS, CIS, WS{sub 2}-CIS, CIS-Au, WS{sub 2}-Au, and WS{sub 2}-CIS-Au. The surface plasmonic resonance effects dramatically intensify the absorption of visible light and help to inject hot electrons into the semiconductors. Our findings open up an efficient method to optimizemore » the type-II structures for photocatalytic water splitting.« less

Density Functional Investigation of the Inclusion of Gold Clusters on a CH 3 S Self-Assembled Lattice on Au(111)

DOE PAGES

Allen, Darnel J.; Archibald, Wayne E.; Harper, John A.; ...

2016-01-01

We employ first-principles density functional theoretical calculations to address the inclusion of gold (Au) clusters in a well-packed CH 3 S self-assembled lattice. We compute CH 3 S adsorption energies to quantify the energetic stability of the self-assembly and gold adsorption and dissolution energies to characterize the structural stability of a series of Au clusters adsorbed at the SAM-Au interface. Our results indicate that the inclusion of Au clusters with less than four Au atoms in the SAM-Au interface enhances the binding of CH 3 S species. In contrast, larger Au clusters destabilize the self-assembly. We attribute this effect tomore » the low-coordinated gold atoms in the cluster. For small clusters, these low-coordinated sites have significantly different electronic properties compared to larger islands, which makes the binding with the self-assembly energetically more favorable. Our results further indicate that Au clusters in the SAM-Au interface are thermodynamically unstable and they will tend to dissolve, producing Au adatoms incorporated in the self-assembly in the form of CH 3 S-Au-SCH 3 species. This is due to the strong S-Au bond which stabilizes single Au adatoms in the self-assembly. Our results provide solid insight into the impact of adatom islands at the CH 3 S-Au interface.« less

Low-temperature and highly enhanced NO2 sensing performance of Au-functionalized WO3 microspheres with a hierarchical nanostructure

NASA Astrophysics Data System (ADS)

Shen, Yanbai; Bi, Hongshan; Li, Tingting; Zhong, Xiangxi; Chen, Xiangxiang; Fan, Anfeng; Wei, Dezhou

2018-03-01

Hierarchically nanostructured WO3 microspheres that had two types of Au functionalization modes (i.e., Au-loaded mode and Au-doped mode) were characterized in terms of their microstructure and NO2 sensing performance. Pure, Au-loaded, and Au-doped WO3 microspheres were synthesized using a hydrothermal method, followed by a dipping method for Au-loaded WO3 microspheres. Microstructure characterization indicated that uniform microspheres with 3-6 μm in diameter were assembled from numerous well-defined individual WO3 nanorods with a single crystal hexagonal structure. The morphology and size of the WO3 microspheres were not affected by the functionalization of the Au nanoparticles, and the W, O, and Au elements were well-distributed in the WO3 microspheres. The NO2 sensing properties indicated that the Au nanoparticles not only improved the sensor response and reproducibility but also decreased the operating temperature at which the sensor response reached a maximum. Gas sensors based on pure, Au-loaded, and Au-doped WO3 microspheres exhibited a linear relationship between the sensor response and NO2 concentration. The sensing performance was significantly enhanced in the following order: pure, Au-loaded, and Au-doped WO3 microspheres. This result is due to the modulation of the depletion layer via oxygen adsorption as well as chemical and electronic sensitization of Au nanoparticles.

Au-Pt alloy nanoparticles obtained by nanosecond laser irradiation of gold and platinum bulk targets in an ethylene glycol solution

NASA Astrophysics Data System (ADS)

Moniri, Samira; Reza Hantehzadeh, Mohammad; Ghoranneviss, Mahmood; Asadi Asadabad, Mohsen

2017-07-01

Au-Pt alloy nanoparticles (NPs) of different compositions ( Au0Pt100 , Au30Pt70 , Au50Pt50 , Au70Pt30 , and Au100Pt0 were obtained using the nanosecond laser ablation of gold and platinum bulk targets in ethylene glycol, followed by mixing highly monodisperse Au and Pt nanocolloids, for the first time. UV-vis absorption spectra of NPs showed that by increasing the Au content in the Au-Pt NPs, the surface plasmon resonance (SPR) peak red-shifted, from 260 to 573nm in a nonlinear way. In addition, the mean crystalline size, crystal structure, d-spacing, and lattice parameters of NPs were estimated from the XRD spectra. Microscopy studies revealed the most NPs have a spherical or near-spherical shape, and the average sizes of Au0Pt100 , Au30Pt70 , Au50Pt50 , Au70Pt30 , and Au100Pt0 NPs were calculated to be 12.50, 14.15, 18.53, 19.29, and 26.38nm, respectively. Also, the chemical identity of the molecules adhering to the NPs surface was considered by Raman and FT-IR spectroscopy techniques. Among different synthesis methods, the demonstrated technique allows easy synthesis of alloy NPs in aqueous media at room temperature with no formation of by-products.

The rational design of a Au(I) precursor for focused electron beam induced deposition

PubMed Central

Marashdeh, Ali; Tiesma, Thiadrik; van Velzen, Niels J C; Harder, Sjoerd; Havenith, Remco W A; De Hosson, Jeff T M

2017-01-01

Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition. Aurophilic interactions are found to play a key role. The short lifetime of ClAuCO in vacuum is explained by strong, destabilizing Au–Au interactions in the solid phase. While aurophilic interactions do not affect the stability of ClAuPMe3, they leave the complex non-volatile. Comparison of crystal structures of ClAuPMe3 and MeAuPMe3 shows that Au–Au interactions are much weaker or partially even absent for the latter structure. This explains its high volatility. However, MeAuPMe3 dissociates unfavorably during FEBIP, making it an unsuitable precursor. The study shows that Me groups reduce aurophilic interactions, compared to Cl groups, which we attribute to electronic rather than steric effects. Therefore we propose MeAuCO as a potential FEBIP precursor. It is expected to have weak Au–Au interactions, making it volatile. It is stable enough to act as a volatile source for Au deposition, being stabilized by 6.5 kcal/mol. Finally, MeAuCO is likely to dissociate in a single step to pure Au. PMID:29354346

Gold as hydrogen: Structural and electronic properties and chemical bonding in Si3Au3+/0/- and comparisons to Si3H3+/0/-

NASA Astrophysics Data System (ADS)

Kiran, Boggavarapu; Li, Xi; Zhai, Hua-Jin; Wang, Lai-Sheng

2006-10-01

A single Au atom has been shown to behave like H in its bonding to Si in several mono- and disilicon gold clusters. In the current work, we investigate the Au /H analogy in trisilicon gold clusters, Si3Au3+/0/-. Photoelectron spectroscopy and density functional calculations are combined to examine the geometric and electronic structure of Si3Au3-. We find that there are three isomers competing for the ground state of Si3Au3- as is the case for Si3H3-. Extensive structural searches show that the potential energy surfaces of the trisilicon gold clusters (Si3Au3-, Si3Au3, and Si3Au3+) are similar to those of the corresponding silicon hydrides. The lowest energy isomers for Si3Au3- and Si3Au3 are structurally similar to a Si3Au four-membered ring serving as a common structural motif. For Si3Au3+, the 2π aromatic cyclotrisilenylium auride ion, analogous to the aromatic cyclotrisilenylium ion (Si3H3+), is the most stable species. Comparison of the structures and chemical bonding between Si3Au3+/0/- and the corresponding silicon hydrides further extends the isolobal analogy between Au and H.

12 CFR 704.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS CORPORATE CREDIT UNIONS § 704.2 Definitions. Adjusted trading means any method or transaction whereby a corporate credit union... means the sum of a corporate credit union's retained earnings, paid-in capital, and membership capital...

Trade Union Mergers: A Survey of the Literature.

ERIC Educational Resources Information Center

Michelson, Grant

2000-01-01

Examines trade union mergers highlighting merger forms, merger motivation, role played by union officers, and merger waves. Discusses the consequences of mergers on members and union performance and concludes that union merger activity has had little impact. (Contains 74 references.) (JOW)

Cytotoxicity of various types of gold-mesoporous silica nanoparticles in human breast cancer cells

PubMed Central

Liu, Guomu; Li, Qiongshu; Ni, Weihua; Zhang, Nannan; Zheng, Xiao; Wang, Yingshuai; Shao, Dan; Tai, Guixiang

2015-01-01

Recently, gold nanoparticles (AuNPs) have shown promising biological applications due to their unique electronic and optical properties. However, the potential toxicity of AuNPs remains a major hurdle that impedes their use in clinical settings. Mesoporous silica is very suitable for the use as a coating material for AuNPs and might not only reduce the cytotoxicity of cetyltrimethylammonium bromide-coated AuNPs but might also facilitate the loading and delivery of drugs. Herein, three types of rod-like gold-mesoporous silica nanoparticles (termed bare AuNPs, core–shell Au@mSiO2NPs, and Janus Au@mSiO2NPs) were specially designed, and the effects of these AuNPs on cellular uptake, toxic behavior, and mechanism were then systematically studied. Our results indicate that bare AuNPs exerted higher toxicity than the Au@mSiO2NPs and that Janus Au@mSiO2NPs exhibited the lowest toxicity in human breast cancer MCF-7 cells, consistent with the endocytosis capacity of the nanoparticles, which followed the order, bare AuNPs > core–shell Au@mSiO2NPs > Janus Au@mSiO2NPs. More importantly, the AuNPs-induced apoptosis of MCF-7 cells exhibited features that were characteristic of intracellular reactive oxygen species (ROS) generation, activation of c-Jun-N-terminal kinase (JNK) phosphorylation, an enhanced Bax-to-Bcl-2 ratio, and loss of the mitochondrial membrane potential. Simultaneously, cytochrome c was released from mitochondria, and the caspase-3/9 cascade was activated. Moreover, both ROS scavenger (N-acetylcysteine) and JNK inhibitor (SP600125) partly blocked the induction of apoptosis in all AuNPs-treated cells. Taken together, these findings suggest that all AuNPs induce apoptosis through the ROS-/JNK-mediated mitochondrial pathway. Thus, Janus Au@mSiO2NPs exhibit the potential for applications in biomedicine, thus aiding the clinical translation of AuNPs. PMID:26491285

Layered double hydroxide supported gold nanoclusters by glutathione-capped Au nanoclusters precursor method for highly efficient aerobic oxidation of alcohols

NASA Astrophysics Data System (ADS)

Li, Lun; Dou, Liguang; Zhang, Hui

2014-03-01

M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 +/- 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ~0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h-1) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au-support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen.M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 +/- 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ~0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h-1) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au-support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen. Electronic supplementary information (ESI) available: Details in experimental and further characterization. See DOI: 10.1039/c3nr05604j

Diphosphine-protected ultrasmall gold nanoclusters: opened icosahedral Au 13 and heart-shaped Au 8 clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shan-Shan; Feng, Lei; Senanayake, Ravithree D.

Two ultrasmall gold clusters, Au 13 and Au 8 , were identified as a distorted I h icosahedral Au 13 and edge-shared “core + 4 exo ” structure Au 8 S 2 cores, respectively. They showed interesting luminescence and electrochemical properties.

Diphosphine-protected ultrasmall gold nanoclusters: opened icosahedral Au 13 and heart-shaped Au 8 clusters

DOE PAGES

Zhang, Shan-Shan; Feng, Lei; Senanayake, Ravithree D.; ...

2018-01-01

Two ultrasmall gold clusters, Au 13 and Au 8 , were identified as a distorted I h icosahedral Au 13 and edge-shared “core + 4 exo ” structure Au 8 S 2 cores, respectively. They showed interesting luminescence and electrochemical properties.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider.

PubMed

Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Baumgart, S; Beavis, D R; Bellwied, R; Benedosso, F; Betts, R R; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Biritz, B; Bland, L C; Bombara, M; Bonner, B E; Botje, M; Bouchet, J; Braidot, E; Brandin, A V; Bruna, E; Bueltmann, S; Burton, T P; Bystersky, M; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Callner, J; Catu, O; Cebra, D; Cendejas, R; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, S U; Clarke, R F; Codrington, M J M; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Daugherity, M; De Silva, C; de Moura, M M; Dedovich, T G; Dephillips, M; Derevschikov, A A; de Souza, R Derradi; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Du, F; Dunlop, J C; Dutta Mazumdar, M R; Edwards, W R; Efimov, L G; Elhalhuli, E; Elnimr, M; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Eun, L; Fachini, P; Fatemi, R; Fedorisin, J; Feng, A; Filip, P; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gaillard, L; Gangadharan, D R; Ganti, M S; Garcia-Solis, E; Ghazikhanian, V; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O; Grosnick, D; Grube, B; Guertin, S M; Guimaraes, K S F F; Gupta, A; Gupta, N; Guryn, W; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Heppelmann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Hofman, D J; Hollis, R S; Huang, H Z; Humanic, T J; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jin, F; Jones, P G; Joseph, J; Judd, E G; Kabana, S; Kajimoto, K; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Kettler, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kopytine, M; Kotchenda, L; Kouchpil, V; Kravtsov, P; Kravtsov, V I; Krueger, K; Krus, M; Kuhn, C; Kumar, L; Kurnadi, P; Lamont, M A C; Landgraf, J M; Lapointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Levine, M J; Li, C; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mall, O I; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Matis, H S; Matulenko, Yu A; McShane, T S; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mischke, A; Mitchell, J; Mohanty, B; Molnar, L; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Nepali, C; Netrakanti, P K; Ng, M J; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okada, H; Okorokov, V; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Planinic, M; Pluta, J; Poljak, N; Poskanzer, A M; Potukuchi, B V K S; Prindle, D; Pruneau, C; Pruthi, N K; Putschke, J; Raniwala, R; Raniwala, S; Ray, R L; Reed, R; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Rykov, V; Sahoo, R; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Shi, X-H; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Staszak, D; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Timoshenko, S; Tlusty, D; Tokarev, M; Trainor, T A; Tram, V N; Trattner, A L; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van Leeuwen, M; Vander Molen, A M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasilevski, I M; Vasiliev, A N; Videbaek, F; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, Q; Wang, X; Wang, X L; Wang, Y; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, Y; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yepes, P; Yoo, I-K; Yue, Q; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, H; Zhang, S; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zhou, J; Zoulkarneev, R; Zoulkarneeva, Y; Zuo, J X

2009-02-06

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

Determination of functionalized gold nanoparticles incorporated in hydrophilic and hydrophobic microenvironments by surface modification of quartz crystal microbalance

NASA Astrophysics Data System (ADS)

Wu, Tsui-Hsun; Liao, Shu-Chuan; Chen, Ying-Fang; Huang, Yi-You; Wei, Yi-Syuan; Tu, Shu-Ju; Chen, Ko-Shao

2013-06-01

In this study, plasma deposition methods were used to immobilize Au electrode of a quartz crystal microbalance (QCM) to create different microenvironments for mass measurement of various modified Au nanoparticles (AuNPs). AuNPs were modified by 11-mercaptoundecanoic acid (MUA) and 1-decanethiol (DCT) for potential applications to drug release, protective coatings, and immunosensors. We aimed to develop a highly sensitive and reliable method to quantify the mass of various modified AuNPs. The surface of AuNPs and Au electrode was coated with polymer films, as determined by Fourier transform infrared spectroscopy and atomic force microscopy. Measurements obtained for various AuNPs and the plasma-treated surface of the Au electrode were compared with those obtained for an untreated Au electrode. According to the resonant frequency shift of QCM, a linear relationship was observed that significantly differed for AuNPs, MUA-AuNPs, and DCT-AuNPs (R2 range, 0.94-0.965, 0.934-0.972, and 0.874-0.9514, respectively). Compared to inductively coupled plasma and micro-computerized tomography, the QCM method with plasma treatment has advantages of real-time monitoring, greater sensitivity, and lower cost. Our results demonstrate that surface modifications measured by a QCM system for various modified AuNPs were reliable.

Architecture effects of glucose oxidase/Au nanoparticle composite Langmuir-Blodgett films on glucose sensing performance

NASA Astrophysics Data System (ADS)

Wang, Ke-Hsuan; Wu, Jau-Yann; Chen, Liang-Huei; Lee, Yuh-Lang

2016-03-01

The Langmuir-Blodgett (LB) deposition technique is employed to prepare nano-composite films consisting of glucose oxidase (GOx) and gold nanoparticles (AuNPs) for glucose sensing applications. The GOx and AuNPs are co-adsorbed from an aqueous solution onto an air/liquid interface in the presence of an octadecylamine (ODA) template monolayer, forming a mixed (GOx-AuNP) monolayer. Alternatively, a composite film with a cascade architecture (AuNP/GOx) is also prepared by sequentially depositing monolayers of AuNPs and GOx. The architecture effects of the composite LB films on the glucose sensing are studied. The results show that the presence of AuNPs in the co-adsorption system does not affect the adsorption amount and preferred conformation (α-helix) of GOx. Furthermore, the incorporation of AuNPs in both composite films can significantly improve the sensing performance. However, the enhancement effects of the AuNPs in the two architectures are distinct. The major effect of the AuNPs is on the facilitation of charge-transfer in the (GOx-AuNP) film, but on the increase of catalytic activity in the (AuNP/GOx) one. Therefore, the sensing performance can be greatly improved by utilizing a film combining both architectures (AuNP/GOx-AuNP).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pei, Dr. Yong; Shao, Nan; Li, Prof. Hui

Using ab initio methods, we investigate the structural evolution of a family of gold-sulfide cluster anions (Au{sub m}S{sub n}{sup -}). We show that this family of clusters exhibits simple size-evolution rules and novel hollow polyhedron structures. The highly stable Au{sub m}S{sub n}{sup -} species such as Au{sub 6}S{sub 4}{sup -}, Au{sub 9}S{sub 5}{sup -}, Au{sub 9}S{sub 6}{sup -}, Au{sub 10}S{sub 6}{sup -}, Au{sub 11}S{sub 6}{sup -}, Au{sub 12}S{sub 8}{sup -}, and Au{sub 13}S{sub 8}{sup -} detected in the recent ion mobility mass spectrometry experiment of Au{sub 25}(SCH{sub 2}CH{sub 2}Ph){sub 18} (Angel et al. ACS Nano2010, 4, 4691) are found tomore » possess either quasi-tetrahedron, pyramidal, quasi-triangular prism, or quasi-cuboctahedron structures. The formation of these polyhedron structures are attributed to the high stability of the S-Au-S structural unit. A unique 'edge-to-face' growth mechanism is proposed to understand the structural evolution of the small Au{sub m}S{sub n}{sup -} cluster. A 3:2 ratio rule of Au/S is suggested for the formation of a hollow polyhedron structure among small-sized Au{sub m}S{sub m} clusters.« less

Facile Syntheses of Monodisperse Ultra-Small Au Clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertino, Massimo F.; Sun, Zhong-Ming; Zhang, Rui

2006-11-02

During our effort to synthesize the tetrahedral Au20 cluster, we found a facile synthetic route to prepare monodisperse suspensions of ultra-small Au clusters AuN (N<12) using diphosphine ligands. In our monophasic and single-pot synthesis, a Au precursor ClAu(I)PPh3 and a bidentate phosphine ligand P(Ph)2(CH2)MP(Ph)2 (Ph = phenyl) are dissolved in an organic solvent. Au(I) is reduced slowly by a borane-tert-butylamine complex to form Au clusters coordinated by the diphosphine ligand. The Au clusters are characterized by both high resolution mass spectrometry and UV-Vis absorption spectroscopy. We found that the mean cluster size obtained depends on the chain length M ofmore » the ligand. In particular, a single monodispersed Au11 cluster is obtained with the P(Ph)2(CH2)3P(Ph)2 ligand, whereas P(Ph)2(CH2)MP(Ph)2 ligands with M = 5 and 6 yield Au10 and Au8 clusters. The simplicity of our synthetic method makes it suitable for large-scale production of nearly monodisperse ultrasmall Au clusters. It is suggested that diphosphines provide a set of flexible ligands to allow size-controlled synthesis of Au nanoparticles.« less

Study on plasmon absorption of hybrid Au-GO-GNP films for SPR sensing application

NASA Astrophysics Data System (ADS)

Mukhtar, Wan Maisarah; Ahmad, Farah Hayati; Samsuri, Nurul Diyanah; Murat, Noor Faezah

2018-06-01

This study proposed the development of hybrid Au-GO-GNP films for the enhancement of plasmon absorption in SPR sensing. Several thicknesses of Au at t=40nm, t=50nm and t=300nm were sputtered on the glass substrate. The hybridization of bilayer and trilayer films were formed by depositing GO-GNP layers and GNP-GO layers on top of various thicknesses of Au coated substrates. UV-Vis spectra analysis was conducted to characterize the plasmon absorption for each configuration. The plasmon absorption was successfully amplified by employing hybrid trilayer Au-GO-GNP with the thickness of Au film was fixed at t=50nm. It is noteworthy to highlight that the employment of bilayer and trilayer configurations are the key success to enhance the SPP excitation. Au-GNP and Au-GNP-GO results no significant outcome in comparison with Au-GO and Au-GO-GNP. A redshift of the absorbance wavelength evinces the presence of GO on Au-GO sample and GNP on Au-GO-GNP sample due to the surface reconstruction. It is important to emphasize that not all bilayer and trilayer configurations able to enhance the plasmon absorption where no significant output was obtained with the hybridization order of Au-GNP and Au-GNP-GO.

Multiple Nonstoichiometric Phases with Discrete Composition Ranges in the CaAu5−CaAu4Bi−BiAu2 System. A Case Study of the Chemistry of Spinodal Decomposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Qisheng; Corbett, John D.

2010-04-01

Synthetic explorations in the CaAu{sub 5}-CaAu{sub 4}Bi-BiAu{sub 2} system at 400 C reveal five separate solid solution regions that show three distinct substitution patterns in the CaAu{sub 5} parent: (I) CaAu{sub 4}(Au{sub 1-m}Bi{sub m}) with 0 {le} m {le} 0.15(1), (II) 0.33(1) {le} m {le} 0.64(1), (III) 0.85(4) {le} m {le} 0.90(2); (IV) (Ca{sub 1-r}Au{sub r})Au{sub 4}(Bi{sub 1-s}Au{sub s}) with 0 {le} r {le} 0.39(1) and 0 {le} s {le} 0.12(2); (V) (Ca{sub 1-p-q}Au{sub p}Bi{sub q})Au{sub 4}Bi with 0.09(2) {le} p {le} 0.13(1) and 0.31(2) {le} q {le} 0.72(4). Single crystal X-ray studies establish that all of these phase regionsmore » have common cubic symmetry F{sub 4}3m and that their structures (MgCu{sub 4}Sn-type, an ordered derivative of MgCu{sub 2}) all feature three-dimensional networks of Au{sub 4} tetrahedra, in which the truncated tetrahedra are centered and capped by Ca/Au, Au/Bi, or Ca/Au/Bi mixtures to give 16-atom Friauf polyhedra. TB-LMTO-ASA and -COHP calculations also reveal that direct interactions between Ca-Au and Ca-Bi pairs of atoms are relatively weak and that the Bi-Au interactions in the unstable ideal CaAu{sub 4}Bi are antibonding in character at E{sub F} but that their bonding is optimized at {+-}1 e. Compositions between the five nonstoichiometric phases appear to undergo spinodal decompositions. The last phenomenon has been confirmed by HRTEM, STEM-HAADF, EPMA, and XRD studies of the nominal composition CaAu{sub 4.25}Bi{sub 0.75}. Its DTA analyses suggest that the phases resulting from spinodal decomposition have nearly the same melting point ({approx}807 C), as expected, and that they are interconvertible through peritectic reactions at {approx}717 C.« less

Atomic and electronic structures of Si(1 1 1)-\\left(\\sqrt{\\mathbf{3}}\\times\\sqrt{\\mathbf{3}}\\right)\\text{R}\\mathbf{3}{{\\mathbf{0}}^{\\circ}} -Au and (6 × 6)-Au surfaces

NASA Astrophysics Data System (ADS)

Patterson, C. H.

2015-12-01

Si(1 1 1)-Au surfaces with around one monolayer of Au exhibit many ordered structures and structures containing disordered domain walls. Hybrid density functional theory (DFT) calculations presented here reveal the origin of these complex structures and tendency to form domain walls. The conjugate honeycomb chain trimer (CHCT) structure of the \\sqrt{3} -Au phase contains Si atoms with non-bonding surface states which can bind Au atoms in pairs in interstices of the CHCT structure and make this surface metallic. Si adatoms adsorbed on the \\sqrt{3} -Au surface induce a gapped surface through interaction with the non-bonding states. Adsorption of extra Au atoms in interstitial sites of the \\sqrt{3} -Au surface is stabilized by interaction with the non-bonding orbitals and leads to higher coverage ordered structures including the ≤ft(6× 6\\right) -Au phase. Extra Au atoms bound in interstitial sites of the \\sqrt{3} -Au surface result in top layer Si atoms with an SiAu4 butterfly wing configuration. The structure of a ≤ft(6× 6\\right) -Au phase, whose in-plane top atomic layer positions were previously determined by an electron holography technique (Grozea et al 1998 Surf. Sci. 418 32), is calculated using total energy minimization. The Patterson function for this structure is calculated and is in good agreement with data from an in-plane x-ray diffraction study (Dornisch et al 1991 Phys. Rev. B 44 11221). Filled and empty state scanning tunneling microscopy (STM) images are calculated for domain walls and the ≤ft(6× 6\\right) -Au structure. The ≤ft(6× 6\\right) -Au phase is 2D chiral and this is evident in computed and actual STM images. ≤ft(6× 6\\right) -Au and domain wall structures contain the SiAu4 motif with a butterfly wing shape. Chemical bonding within the Si-Au top layers of the \\sqrt{3} -Au and ≤ft(6× 6\\right) -Au surfaces is analyzed and an explanation for the SiAu4 motif structure is given.

History and Status of the CIS Customs Union

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawson, T.M.; Erickson, S.A.

1999-08-31

This report explores the history of the CIS Customs Union and the major obstacles the Union faces in its implementation. Investigation of the Customs Union is necessary as its implementation could effect the Second Line of Defense (SLD) Program. Russian Customs contends that radiation detectors should not be installed along the Customs Union members borders of as the borders will be dissolved when the Union is implemented.

Laser ablation synthesis of new gold phosphides using red phosphorus and nanogold as precursors. Laser desorption ionisation time-of-flight mass spectrometry.

PubMed

Panyala, Nagender Reddy; Peña-Méndez, Eladia María; Havel, Josef

2012-05-15

Gold phosphides show unique optical or semiconductor properties and there are extensive high technology applications, e.g. in laser diodes, etc. In spite of the various AuP structures known, the search for new materials is wide. Laser ablation synthesis is a promising screening and synthetic method. Generation of gold phosphides via laser ablation of red phosphorus and nanogold mixtures was studied using laser desorption ionisation time-of-flight mass spectrometry (LDI TOFMS). Gold clusters Au(m)(+) (m = 1 to ~35) were observed with a difference of one gold atom and their intensities were in decreasing order with respect to m. For P(n)(+) (n = 2 to ~111) clusters, the intensities of odd-numbered phosphorus clusters are much higher than those for even-numbered phosphorus clusters. During ablation of P-nanogold mixtures, clusters Au(m)(+) (m = 1-12), P(n)(+) (n = 2-7, 9, 11, 13-33, 35-95 (odd numbers)), AuP(n)(+) (n = 1, 2-88 (even numbers)), Au(2)P(n)(+) (n = 1-7, 14-16, 21-51 (odd numbers)), Au(3)P(n)(+) (n = 1-6, 8, 9, 14), Au(4)P(n)(+) (n = 1-9, 14-16), Au(5)P(n)(+) (n = 1-6, 14, 16), Au(6)P(n)(+) (n = 1-6), Au(7)P(n)(+) (n = 1-7), Au(8)P(n)(+) (n = 1-6, 8), Au(9)P(n)(+) (n = 1-10), Au(10)P(n)(+) (n = 1-8, 15), Au(11)P(n)(+) (n = 1-6), and Au(12)P(n)(+) (n = 1, 2, 4) were detected in positive ion mode. In negative ion mode, Au(m)(-) (m = 1-5), P(n)(-) (n = 2, 3, 5-11, 13-19, 21-35, 39, 41, 47, 49, 55 (odd numbers)), AuP(n)(-) (n = 4-6, 8-26, 30-36 (even numbers), 48), Au(2)P(n)(-) (n = 2-5, 8, 11, 13, 15, 17), A(3) P(n)(-) (n = 6-11, 32), Au(4)P(n)(-) (n = 1, 2, 4, 6, 10), Au(6)P(5)(-), and Au(7)P(8)(-) clusters were observed. In both modes, phosphorus-rich Au(m)P(n) clusters prevailed. The first experimental evidence for formation of AuP(60) and gold-covered phosphorus Au(12)P(n) (n = 1, 2, 4) clusters is given. The new gold phosphides generated might inspire synthesis of new Au-P materials with specific properties. Copyright © 2012 John Wiley & Sons, Ltd.

In vitro extracellular recording and stimulation performance of nanoporous gold-modified multi-electrode arrays.

PubMed

Kim, Yong Hee; Kim, Gook Hwa; Kim, Ah Young; Han, Young Hwan; Chung, Myung-Ae; Jung, Sang-Don

2015-12-01

Nanoporous gold (Au) structures can reduce the impedance and enhance the charge injection capability of multi-electrode arrays (MEAs) used for interfacing neuronal networks. Even though there are various nanoporous Au preparation techniques, fabrication of MEA based on low-cost electro-codeposition of Ag:Au has not been performed. In this work, we have modified a Au MEA via the electro-codeposition of Ag:Au alloy, followed by the chemical etching of Ag, and report on the in vitro extracellular recording and stimulation performance of the nanoporous Au-modified MEA. Ag:Au alloy was electro-codeposited on a bilayer lift-off resist sputter-deposition passivated Au MEA followed by chemical etching of Ag to form a porous Au structure. The porous Au structure was analyzed by scanning electron microscopy and tunneling electron microscopy and found to have an interconnected nanoporous Au structure. The impedance value of the nanoporous Au-modified MEA is 15.4 ± 0.55 kΩ at 1 kHz, accompanied by the base noise V rms of 2.4 ± 0.3 μV. The charge injection limit of the nanoporous Au-modified electrode estimated from voltage transient measurement is approximately 1 mC cm(-2), which is comparable to roughened platinum and carbon nanotube electrodes. The charge injection capability of the nanoporous Au-modified MEA was confirmed by observing stimulus-induced spikes at above 0.2 V. The nanoporous Au-modified MEA showed mechanical durability upon ultrasonic treatment for up to an hour. Electro-codeposition of Ag:Au alloy combined with chemical etching Ag is a low-cost process for fabricating nanoporous Au-modified MEA suitable for establishing the stimulus-response relationship of cultured neuronal networks.

In vitro extracellular recording and stimulation performance of nanoporous gold-modified multi-electrode arrays

NASA Astrophysics Data System (ADS)

Kim, Yong Hee; Kim, Gook Hwa; Kim, Ah Young; Han, Young Hwan; Chung, Myung-Ae; Jung, Sang-Don

2015-12-01

Objective. Nanoporous gold (Au) structures can reduce the impedance and enhance the charge injection capability of multi-electrode arrays (MEAs) used for interfacing neuronal networks. Even though there are various nanoporous Au preparation techniques, fabrication of MEA based on low-cost electro-codeposition of Ag:Au has not been performed. In this work, we have modified a Au MEA via the electro-codeposition of Ag:Au alloy, followed by the chemical etching of Ag, and report on the in vitro extracellular recording and stimulation performance of the nanoporous Au-modified MEA. Approach. Ag:Au alloy was electro-codeposited on a bilayer lift-off resist sputter-deposition passivated Au MEA followed by chemical etching of Ag to form a porous Au structure. Main results. The porous Au structure was analyzed by scanning electron microscopy and tunneling electron microscopy and found to have an interconnected nanoporous Au structure. The impedance value of the nanoporous Au-modified MEA is 15.4 ± 0.55 kΩ at 1 kHz, accompanied by the base noise V rms of 2.4 ± 0.3 μV. The charge injection limit of the nanoporous Au-modified electrode estimated from voltage transient measurement is approximately 1 mC cm-2, which is comparable to roughened platinum and carbon nanotube electrodes. The charge injection capability of the nanoporous Au-modified MEA was confirmed by observing stimulus-induced spikes at above 0.2 V. The nanoporous Au-modified MEA showed mechanical durability upon ultrasonic treatment for up to an hour. Significance. Electro-codeposition of Ag:Au alloy combined with chemical etching Ag is a low-cost process for fabricating nanoporous Au-modified MEA suitable for establishing the stimulus-response relationship of cultured neuronal networks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosli, Nur Shafawati binti; Rahman, Azhar Abdul; Aziz, Azlan Abdul

Gold nanoparticles (AuNPs) received a great deal of attention for biomedical applications, especially in diagnostic imaging and therapeutics. Even though AuNPs have potential benefits in biomedical applications, the impact of AuNPs on human and environmental health still remains unclear. The use of AuNPs which is a high-atomic-number materials, provide advantages in terms of radiation dose enhancement. However, before this can become a clinical reality, cytotoxicity of the AuNPs has to be carefully evaluated. Cytotoxicity test is a rapid, standardized test that is very sensitive to determine whether the nanoparticles produced are harmful or benign on cellular components. In this workmore » the size and concentration dependence of AuNPs cytotoxicity in breast cancer cell lines (MCF-7) are tested by using WST-1 assay. The sizes of AuNPs tested were 13 nm, 50 nm, and 70 nm. The cells were seeded in the 96-well plate and were treated with different concentrations of AuNPs by serial dilution for each size of AuNPs. The high concentration of AuNPs exhibit lower cell viability compared to low concentration of AuNPs. We quantified the toxicity of AuNPs in MCF-7 cell lines by determining the IC{sub 50} values in WST-1 assays. The IC{sub 50} values (inhibitory concentrations that effected 50% growth inhibition) of 50 nm AuNPs is lower than 13 nm and 70 nm AuNPs. Mean that, 50nm AuNPs are more toxic to the MCF-7 cells compared to smaller and larger sizes AuNPs. The presented results clearly indicate that the cytotoxicity of AuNPs depend not only on the concentration, but also the size of the nanoparticles.« less

Highly Efficient Selective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol over Gold Supported on Zinc Oxide Materials

DOE PAGES

Chen, Hangning; Cullen, David A.; Larese, J. Z.

2015-11-30

We used Au/ZnO catalysts for liquid-phase selective hydrogenation of cinnamaldehyde to cinnamyl alcohol and compared with Au/Fe 2O 3 catalysts. To investigate the influence of the support on the hydrogenation activity and selectivity, three different Au/ZnO catalysts were synthesized, including Au/rod-tetrapod ZnO, Au/porous ZnO, and Au/ZnO-CP prepared using a coprecipitation method. Moreover, the influence of calcination temperature was also systematically investigated in this study. The characterization of Au/ZnO catalysts was performed using ICP, N 2 adsorption/desorption isotherms, X-ray diffraction, scanning transmission electron microscopy, and X-ray photoelectron spectroscopy. Among all the supported Au catalysts prepared in this study, Au/ZnO-CP exhibits bothmore » the highest hydrogenation activity and selectivity. Using a 1.5% Au/ZnO-CP catalyst, 100% selectivity could be achieved with 94.9% conversion. Finally, we find that the Au particle (size and shape), the ZnO support (size and surface texture) and the interaction between Au and ZnO are three important parameters for achieving a highly efficient Au/ZnO catalyst.« less

An experimental study of Au removal from solution by non-metabolizing bacterial cells and their exudates

NASA Astrophysics Data System (ADS)

Kenney, Janice P. L.; Song, Zhen; Bunker, Bruce A.; Fein, Jeremy B.

2012-06-01

In this study, we examine the initial interactions between aqueous Au(III)-hydroxide-chloride aqueous complexes and bacteria by measuring the effects of non-metabolizing cells on the speciation and distribution of Au. We conducted batch Au(III) removal experiments, measuring the kinetics and pH dependence of Au removal, and tracking valence state transformations and binding environments using XANES spectroscopy. These experiments were conducted using non-metabolizing cells of Bacillus subtilis or Pseudomonas putida suspended in a 5 ppm Au(III)-(hydroxide)-chloride starting solution of 0.1 M NaClO4 to buffer ionic strength. Both bacterial species removed greater than 85% of the Au from solution after 2 h of exposure time below approximately pH 5. Above pH 5, the extent of Au removed from solution decreased with increasing pH, with less than approximately 10% removal of Au from solution above pH 7.5. Kinetics experiments indicated that the Au removal with both bacterial species was rapid at pH 3, and slowed with increasing pH. Reversibility experiments demonstrated that (1) once the Au was removed from solution, adjusting 35 the pH alone did not remobilize the Au into solution and (2) the presence of cysteine in solution in the reversibility experiments caused Au to desorb, suggesting that the Au was not internalized within the bacterial cells. Our results suggest that Au removal occurs as a two-step pH-dependent adsorption reduction process. The speciation of the aqueous Au and the bacterial surface appears to control the rate of Au removal from solution. Under low pH conditions, the cell walls are only weakly negatively charged and aqueous Au complexes adsorb readily and rapidly. With increasing pH, the cell wall becomes more negatively charged, slowing adsorption significantly. The XANES data demonstrate that the reduction of Au(III) by bacterial exudates is slower and less extensive than the reduction observed in the bacteria-bearing systems, and we conclude that Au reduction occurs most rapidly and extensively upon interaction with cell wall functional groups.

Preparation, Spectroscopic Characterization, and Frontier MO Study of the Heteronuclear Luminescent [Pt(2)Au(2)(dmb)(2)(PPh(3))(4)](PF(6))(2) Cluster (dmb = 1,8-Diisocyano-p-menthane). A Cluster with a Formal Au(0)-Au(0) Bond Encapsulated inside a "Pt(2)(dmb)(2)(2+) " Fragment.

PubMed

Zhang, Tianle; Drouin, Marc; Harvey, Pierre D.

1999-11-01

The title compound is prepared from the direct reaction of Pt(2)(dba)(3) (dba = dibenzylideneacetone) and [Au(PPh(3))(2)](PF(6)) in the presence of 1,8-diisocyano-p-methane (dmb), with Pt(2)(dmb)(2)Cl(2), [Pt(4)(dmb)(4)(PPh(3))(2)](PF(6))(2), and (PPh(3))AuCl being formed as parallel products. X-ray crystallography reveals the presence of a quasi-linear PPh(3)Au-AuPPh(3) fragment encapsulated inside a "Pt(2)(dmb)(2)(2+)" ring which is axially coordinated with two PPh(3) ligands. The d(AuAu) is 2.5977(6) Å and is indicative of a strong Au-Au single bond. The IR nu(CN) data reveal that the Pt oxidation state is I, which places the Au oxidation state at 0. The PtAu distances are 2.8422(5) and 2.8082(5) Å. The Raman-active nu(Au(2)), nu(PtAu) (b(2g) + a(g)), nu(PtP), nu(AuP), and nu(PtC) are found at 121.2, approximately 100, 85.5, 162.1, 183.1, and 457.2, and 440.9 cm(-)(1), respectively. The PtAu (0.67 mdyn Å(-)(1)) and Au(2) (1.21 mdyn Å(-)(1)) force constants (F) confirm the presence of medium PtAu and strong Au(2) bonding interactions. The absorption spectra are characterized by strong bands at lambda(max) (epsilon, M(-1) cm(-1)) at 316 (32 300), 366 (37 800), and 418 nm (21 500) and lower intensity features at 516 (2860) and 655 nm (834). The cluster is luminescent at low temperatures (solid and frozen glasses), and in the solid state at room temperature, and exhibits an emission band at approximately 875 nm, and an emission lifetime, tau(e), of 4.4 +/- 0.4 ns (solvent = butyronitrile, T = 77 K).

Investigation of the thermal annealing effect on electrical properties of Ni/Au, Ni/Mo/Au and Mo/Au Schottky barriers on AlGaN/GaN heterostructures

NASA Astrophysics Data System (ADS)

Sleptsov, E. V.; Chernykh, A. V.; Chernykh, S. V.; Dorofeev, A. A.; Gladysheva, N. B.; Kondakov, M. N.; Sleptsova, A. A.; Panichkin, A. V.; Konovalov, M. P.; Didenko, S. I.

2017-03-01

Investigation of the thermal annealing effect on Schottky barrier parameters and the leakage current of Ni/Au, Ni/Mo/Au and Mo/Au Schottky barriers on AlGaN/GaN heterostructures has been performed. Improvement of Schottky barrier parameters after annealing of the investigated metallization schemes was observed. Ni/Au and Mo/Au contacts drastically degrade after annealing at the temperatures higher than 400 °C, whereas the Ni/Mo/Au contact exhibits excellent parameters after 500 °C annealing (qϕb = 1.00 eV, n = 1.13 и Ileak = 5 μA).

Connected Au network in annealed Ni/Au thin films on p-GaN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, S. P.; Jang, H. W.; Noh, D. Y.

2007-11-12

We report the formation of a connected Au network in annealed Ni/Au thin films on p-GaN, which was studied by scanning electron microscopy, transmission electron microscopy, and synchrotron x-ray diffraction. As the Ni was oxidized into NiO upon annealing at 530 deg. C in air, the Au layer was transformed to an interconnected network with an increased thickness. During annealing, Ni atoms diffuse out onto the Au through defects to form NiO, while Au atoms replace the Ni positions. The Au network grows downward until it reaches the p-GaN substrate, and NiO columns fill the space between the Au network.

76 FR 13504 - Conversions of Insured Credit Unions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-14

... Conversions of Insured Credit Unions AGENCY: National Credit Union Administration (NCUA). ACTION: Final rule... phrase ``Regional Director'' in NCUA's rule on credit union to mutual savings bank conversions. For... for the review and approval of certain types of credit union conversions from the Regional Directors...

4. Photocopy of blue line drawing (on file at La ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Photocopy of blue line drawing (on file at La Grande District Office, La Grande, Oregon) USDA Forest Service, 1938 SITE PLAN, UNION RANGER STATION - Union Ranger District Compound, Fronting State Highway 203, at West edge of Union, Union, Union County, OR

16 CFR Appendix L to Part 305 - Sample Labels

Code of Federal Regulations, 2010 CFR

2010-01-01

... Part 305—Sample Labels ER29AU07.122 PROTOTYPE LABEL 1 ER29AU07.123 PROTOTYPE LABEL 2 ER29AU07.124 PROTOTYPE LABEL 3 ER29AU07.125 PROTOTYPE LABEL 4 ER29AU07.126 SAMPLE LABEL 1 ER29AU07.127 SAMPLE LABEL 2...

Directed self-assembly of nanogold using a chemically modified nanopatterned surface

NASA Astrophysics Data System (ADS)

Nidetz, Robert; Kim, Jinsang

2012-02-01

Electron-beam lithography (EBL) was used to define an aminosilane nanopatterned surface in order to electrostatically self-assemble gold nanoparticles (Au NPs). The chemically modified nanopatterned surfaces were immersed into a Au NP solution to allow the Au NPs to self-assemble. Equilibrium self-assembly was achieved in only 20 min. The number of Au NPs that self-assembled on an aminosilane dot was controlled by manipulating the diameters of both the Au NPs and the dots. Adding salt to the Au NP solution enabled the Au NPs to self-assemble in greater numbers on the same sized dot. However, the preparation of the Au NP solution containing salt was sensitive to spikes in the salt concentration. These spikes led to aggregation of the Au NPs and non-specific deposition of Au NPs on the substrate. The Au NP patterned surfaces were immersed in a sodium hydroxide solution in order to lift-off the patterned Au NPs, but no lift-off was observed without adequate physical agitation. The van der Waals forces are too strong to allow for lift-off despite the absence of electrostatic forces.

Two Barium Gold Iodates: Syntheses, Structures, and Properties of Polar BaAu(IO3)5 and Nonpolar HBa4Au(IO3)12 Materials.

PubMed

Yang, Bing-Ping; Hu, Chun-Li; Mao, Fei-Fei; Xu, Xiang; Mao, Jiang-Gao

2017-06-19

Two new barium gold iodates, namely, BaAu(IO 3 ) 5 and HBa 4 Au(IO 3 ) 12 , have been prepared. BaAu(IO 3 ) 5 crystallizes in the polar space group Pca2 1 , whereas HBa 4 Au(IO 3 ) 12 crystallizes in the centrosymmetric space group P2 1 /c. BaAu(IO 3 ) 5 consists of unique polar [Au(IO 3 ) 4 ] - anions whose four iodate groups are located at both sides of the AuO 4 plane and the polarity points in the [001̅] direction. BaAu(IO 3 ) 5 displays strong second-harmonic-generation (SHG) effects about 0.6KTiOPO 4 (KTP) and is phase-matchable. Thermal properties, optical spectra analyses, and theoretical calculations are also reported.

Tunable, biodegradable gold nanoparticles as contrast agents for computed tomography and photoacoustic imaging

PubMed Central

Cheheltani, Rabee; Ezzibdeh, Rami M.; Chhour, Peter; Pulaparthi, Kumidini; Kim, Johoon; Jurcova, Martina; Hsu, Jessica C.; Blundell, Cassidy; Litt, Harold I.; Ferrari, Victor A.; Allcock, Harry R.; Sehgal, Chandra M.; Cormode, David P.

2016-01-01

Gold nanoparticles (AuNP) have been proposed for many applications in medicine. Although large AuNP (>5.5 nm) are desirable for their longer blood circulation and accumulation in diseased tissues, small AuNP (<5.5 nm) are required for excretion via the kidneys. We present a novel platform where small, excretable AuNP are encapsulated into biodegradable poly di(carboxylatophenoxy)phosphazene (PCPP) nanospheres. These larger nanoparticles (Au-PCPP) can perform their function as contrast agents, then subsequently break down into harmless byproducts and release the AuNP for swift excretion. Homogeneous Au-PCPP were synthesized using a microfluidic device. The size of the Au-PCPP can be controlled by the amount of polyethylene glycol-polylysine (PEG-PLL) block co-polymer in the formulation. Synthesis of Au-PCPP nanoparticles and encapsulation of AuNP in PCPP were evaluated using transmission electron microscopy and their biocompatibility and biodegradability confirmed in vitro. The Au-PCPP nanoparticles were found to produce strong computed tomography contrast. The UV-Vis absorption peak of Au-PCPP can be tuned into the near infrared region via inclusion of varying amounts of AuNP and controlling the nanoparticle size. In vitro and in vivo experiments demonstrated the potential of Au-PCPP as contrast agents for photoacoustic imaging. Therefore, Au-PCPP nanoparticles have high potency as contrast agents for two imaging modalities, as well as being biocompatible and biodegradable, and thus represent a platform with potential for translation into the clinic. PMID:27322961

Au38(SPh)24: Au38 Protected with Aromatic Thiolate Ligands.

PubMed

Rambukwella, Milan; Burrage, Shayna; Neubrander, Marie; Baseggio, Oscar; Aprà, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Dass, Amala

2017-04-06

Au 38 (SR) 24 is one of the most extensively investigated gold nanomolecules along with Au 25 (SR) 18 and Au 144 (SR) 60 . However, so far it has only been prepared using aliphatic-like ligands, where R = -SC 6 H 13 , -SC 12 H 25 and -SCH 2 CH 2 Ph. Au 38 (SCH 2 CH 2 Ph) 24 when reacted with HSPh undergoes core-size conversion to Au 36 (SPh) 24 , and existing literature suggests that Au 38 (SPh) 24 cannot be synthesized. Here, contrary to prevailing knowledge, we demonstrate that Au 38 (SPh) 24 can be prepared if the ligand exchanged conditions are optimized, under delicate conditions, without any formation of Au 36 (SPh) 24 . Conclusive evidence is presented in the form of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), electrospray ionization mass spectra (ESI-MS) characterization, and optical spectra of Au 38 (SPh) 24 in a solid glass form showing distinct differences from that of Au 38 (S-aliphatic) 24 . Theoretical analysis confirms experimental assignment of the optical spectrum and shows that the stability of Au 38 (SPh) 24 is not negligible with respect to that of its aliphatic analogous, and contains a significant component of ligand-ligand attractive interactions. Thus, while Au 38 (SPh) 24 is stable at RT, it converts to Au 36 (SPh) 24 either on prolonged etching (longer than 2 hours) at RT or when etched at 80 °C.

Mass spectrometric identification of water-soluble gold nanocluster fractions from sequential size-selective precipitation.

PubMed

Yang, Xiupei; Su, Yan; Paau, Man Chin; Choi, Martin M F

2012-02-07

This paper presents a simple and convenient methodology to separate and characterize water-soluble gold nanocluster stabilized with penicillamine ligands (AuNC-SR) in aqueous medium by sequential size-selective precipitation (SSSP) and mass spectrometry (MS). The highly polydisperse crude AuNC-SR product with an average core diameter of 2.1 nm was initially synthesized by a one-phase solution method. AuNCs were then precipitated and separated successively from larger to smaller ones by progressively increasing the concentration of acetone in the aqueous AuNCs solution. The SSSP fractions were analyzed by UV-vis spectroscopy, matrix-assisted laser desorption/ionization time-of-flight-MS, and thermogravimetric analysis (TGA). The MS and TGA data confirmed that the fractions precipitated from 36, 54, 72, and 90% v/v acetone (F(36%), F(54%), F(72%), and F(90%)) comprised families of close core size AuNCs with average molecular formulas of Au(38)(SR)(18), Au(28)(SR)(15), Au(18)(SR)(12), and Au(11)(SR)(8), respectively. In addition, F(36%), F(54%), F(72%), and F(90%) contained also the typical magic-sized gold nanoparticles of Au(38), Au(25), Au(18), and Au(11), respectively, together with some other AuNCs. This study shed light on the potential use of SSSP for simple and large-scale preliminary separation of polydisperse water-soluble AuNCs into different fractions with a relatively narrower size distribution. © 2012 American Chemical Society

Spiraling between qualitative and quantitative data on women's health behaviors: a double helix model for mixed methods.

PubMed

Mendlinger, Sheryl; Cwikel, Julie

2008-02-01

A double helix spiral model is presented which demonstrates how to combine qualitative and quantitative methods of inquiry in an interactive fashion over time. Using findings on women's health behaviors (e.g., menstruation, breast-feeding, coping strategies), we show how qualitative and quantitative methods highlight the theory of knowledge acquisition in women's health decisions. A rich data set of 48 semistructured, in-depth ethnographic interviews with mother-daughter dyads from six ethnic groups (Israeli, European, North African, Former Soviet Union [FSU], American/Canadian, and Ethiopian), plus seven focus groups, provided the qualitative sources for analysis. This data set formed the basis of research questions used in a quantitative telephone survey of 302 Israeli women from the ages of 25 to 42 from four ethnic groups. We employed multiple cycles of data analysis from both data sets to produce a more detailed and multidimensional picture of women's health behavior decisions through a spiraling process.

Tracing the drift of MH370 debris throughout the Indian Ocean

NASA Astrophysics Data System (ADS)

Biastoch, Arne; Durgadoo, Jonathan V.; Rühs, Siren

2017-04-01

On 8 March 2014, a missing Boeing 777 of Malaysia Airlines (MH370) disappeared from radar screens. Since then, extensive search efforts aim to find the missing plane in the southeastern Indian Ocean. Starting with a flaperon washed up at La Réunion in July 2015, several pieces of debris were found at different shores at islands and African coasts in the southwestern Indian Ocean. Ocean currents were examined to understand the drift paths of debris throughout the Indian Ocean, and in consequence to identify the location of MH370. Here we present a series of Lagrangian analyses in which we follow particles representing virtual pieces of debris advected in an operational high-resolution ocean model. Of particular importance is the lare-scale influence of surface waves through Stokes drift. Large number of particles are analysed in statistical approaches to provide most likely starting locations. Different pieces of debris are combined to refine probability maps of their joint start positions. Forward vs. backward advection approaches are compared.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chima, C.M.

This study evaluates the commercial energy sector of the Economic Community of West African States (ECOWAS). Presently, an economic union exists between the 16 countries of West Africa that are members of ECOWAS. Although the ECOWAS region has plentiful resources of commercial energy, it faces problems in this sector for two reasons. First is the problem resulting from the diminishing traditional energy resources such as wood fuel and charcoal. Second, most ECOWAS members, except Nigeria, are net importers of commercial energy, and hence face a high import burden for oil. Liquid petroleum is the dominant form of commercial energy usedmore » in the ECOWAS despite the availability of other resources. This author basically argues that the best policy and strategy solution for dealing with energy problems is through a combination of regional cooperative effort, and a more-intensive country level. The intensity-of-use hypothesis is tested with case studies of Ghana, the Ivory Coast, and Nigeria. The results indicate that newly developing countries can deviate from the expectations of the hypothesis.« less

[On a contribution of Boris Balinsky to the comparative and ecological embryology of amphibians].

PubMed

Desnitskiĭ, A G

2014-01-01

The outstanding embryologist Boris Ivanovich Balinsky (1905-1997) worked in the Soviet Union up to 1941 and in South Africa since 1949. His experimental studies fulfilled during the Soviet period of his scientific career mainly on the embryos of the caudate amphibians are widely known. After moving to Africa (Johannesburg), he continued the research of amphibian development, with using those possibilities, which were offered by the diverse fauna of local Anura. Other embryologists started complex studies of tropical frog ontogenies (mainly from South and Central America) 30-40 years later than Balinsky. Unfortunately, his pioneering works on numerous African species are poorly known (with the exceptions of the description of the development of endodermal derivatives in Xenopus laevis and the analysis of limb induction in the toad genus Amietophrynus). In this paper, the works of Balinsky are analyzed (with the emphasis on comparative and ecological aspects) and his priority in using of "nonmodel" tropical and subtropical anurans in embryological studies has been shown.

Ochratoxin A in Moroccan foods: occurrence and legislation.

PubMed

Zinedine, Abdellah

2010-05-01

Ochratoxin A (OTA) is secondary metabolite naturally produced in food and feed by toxigenic fungi, especially some Aspergillus species and Penicillium verucosum. OTA is one of the most studied mycotoxins and is of great interest due to its toxic effects on human and animals. OTA is produced in different food and feed matrices and contaminates a large range of base foods including cereals and derivatives, spices, dried fruits, wine and coffee, etc. Morocco, a North African country, has a climate characterized by high humidity and temperature, which probably favors the growth of molds. This contribution gives an overview of principal investigations about the presence of OTA in foods available in Morocco. Due to its toxicity, OTA presence is increasingly regulated worldwide, especially in countries of the European Union. However, up until now, no regulation limits were in force in Morocco, probably due to the ignorance of the health and economic problems resulting from OTA contamination. Finally, recommendations and future research directions are given required to assess the situation completely.

Ochratoxin A in Moroccan Foods: Occurrence and Legislation

PubMed Central

Zinedine, Abdellah

2010-01-01

Ochratoxin A (OTA) is secondary metabolite naturally produced in food and feed by toxigenic fungi, especially some Aspergillus species and Penicillium verucosum. OTA is one of the most studied mycotoxins and is of great interest due to its toxic effects on human and animals. OTA is produced in different food and feed matrices and contaminates a large range of base foods including cereals and derivatives, spices, dried fruits, wine and coffee, etc. Morocco, a North African country, has a climate characterized by high humidity and temperature, which probably favors the growth of molds. This contribution gives an overview of principal investigations about the presence of OTA in foods available in Morocco. Due to its toxicity, OTA presence is increasingly regulated worldwide, especially in countries of the European Union. However, up until now, no regulation limits were in force in Morocco, probably due to the ignorance of the health and economic problems resulting from OTA contamination. Finally, recommendations and future research directions are given required to assess the situation completely. PMID:22069630

An evidence base for International Health Regulations: quantitative measurement of the impacts of epidemic disease on international trade.

PubMed

Kimball, A M; Wong, K Y; Taneda, K

2005-12-01

When cholera broke out in Mozambique, Kenya, Tanzania and Uganda in 1997, an urgent measure was filed with the Sanitary and Phytosanitary Committee of the World Trade Organization, by the European Union, citing the protection of human health, to limit imports of fish products. The authors analysed import data on specified products over time to quantify the trade impact of this measure. Using previous specific trade trends, the authors modelled expected trade flows and compared observed imports with expected imports to calculate the potential cost of lost trade. The conclusion of this analysis was that the impact of European restrictions on fish exports from Mozambique, Kenya, Tanzania and Uganda on the economies of these African countries was at least US dollar 332,217,415 for the years 1998 to 2002. Insights from such quantitative studies will be important in making policy choices under the revised International Health Regulations of the World Health Organization and should inform the discussion about the adoption of these regulations.

The two worlds of race: a historical view.

PubMed

Franklin, John Hope

2011-01-01

Franklin's essay traces the practices, policies, and laws that, from colonial times through the mid-1960s moment when he composed his essay, created and sustained the two worlds of race in America. He outlines the history of efforts from that period to alleviate racial distinctions and to foster a "world of equality and complete human fellowship." Franklin cautions, however, that even certain well-intentioned efforts to extend services, opportunities, and rights to African Americans sometimes reinforced segregation and discrimination. He considers how key historical, legal, political, and social developments from the twentieth century -- World War II, the growth of labor unions, the Great Migration, America's ascendancy as a world power, among others -- advanced racial equality in America while often intensifying the backlash from opponents to such equality. Still, Franklin concludes optimistically that however strident those opponents may be, they "have been significantly weakened by the very force of the numbers and elements now seeking to eliminate the two worlds of race."

Gold Nanoparticle-Quantum Dot Fluorescent Nanohybrid: Application for Localized Surface Plasmon Resonance-induced Molecular Beacon Ultrasensitive DNA Detection

NASA Astrophysics Data System (ADS)

Adegoke, Oluwasesan; Park, Enoch Y.

2016-11-01

In biosensor design, localized surface plasmon resonance (LSPR)-induced signal from gold nanoparticle (AuNP)-conjugated reporter can produce highly sensitive nanohybrid systems. In order to retain the physicochemical properties of AuNPs upon conjugation, high colloidal stability in aqueous solution is needed. In this work, the colloidal stability with respect to the zeta potential (ZP) of four negatively charged thiol-functionalized AuNPs, thioglycolic (TGA)-AuNPs, 3-mercaptopropionic acid (MPA)-AuNPs, l-cysteine-AuNPs and l-glutathione (GSH)-AuNPs, and a cationic cyteamine-capped AuNPs was studied at various pHs, ionic strength, and NP concentration. A strong dependence of the ZP charge on the nanoparticle (NP) concentration was observed. High colloidal stability was exhibited between pH 3 and 9 for the negatively charged AuNPs and between pH 3 and 7 for the cationic AuNPs. With respect to the ionic strength, high colloidal stability was exhibited at ≤104 μM for TGA-AuNPs, l-cysteine-AuNPs, and GSH-AuNPs, whereas ≤103 μM is recommended for MPA-AuNPs. For the cationic AuNPs, very low ionic strength of ≤10 μM is recommended due to deprotonation at higher concentration. GSH-AuNPs were thereafter bonded to SiO2-functionalized alloyed CdZnSeS/ZnSe1.0S1.3 quantum dots (SiO2-Qdots) to form a plasmon-enhanced AuNP-SiO2-Qdots fluorescent nanohybrid. The AuNP-SiO2-Qdots conjugate was afterward conjugated to a molecular beacon (MB), thus forming an ultrasensitive LSPR-induced SiO2-Qdots-MB biosensor probe that detected a perfect nucleotide DNA sequence at a concentration as low as 10 fg/mL. The limit of detection was 11 fg/mL (1.4 fM) while the biosensor probe efficiently distinguished between single-base mismatch and noncomplementary sequence target.

Slab melting and the origin of gold in Au and Au-Cu deposits: geochemical clues from recent adakites.

NASA Astrophysics Data System (ADS)

Polve, M.; Maury, R.; Joron, J. L.

2003-04-01

Understanding the genetic processes responsible for the common occurrence of Au and Au-Cu deposits in subduction environments is a fairly "hot" question nowadays, as it is clear that most subduction-related magmatic rocks are barren. Studies of space and time relationships between magmatic intrusions, hydrothermal episodes and Au deposits have shown that, very often, Au deposits are associated with adakitic intrusions (Thieblemont et al, 1997, Sajona and Maury, 1998). Adakites are here understood as being generated by melting of the subducting oceanic crust. This study aims to check wether or not magmas derived from melted oceanic crust do contain significantly more Au than regular calc-alkaline magmas by measuring directly Au concentrations in fresh (and barren) adakites and equivalent calc-alkaline andesites. There is a lack of reliable data on Au content in unaltered adakites and andesites, because Au analyses are generally done on hydrothermalized rocks in connection with Au deposits and also because old measurements may give overestimated Au contents, due to technical limitations. Therefore we compiled recent literature data on gold contents of fresh calc-alkaline rocks, and measured Au on a selection of 40 well studied and dated adakites from different localities (Philippines, Baja California). Analyses have been performed either by INAA or by ICP-MS after Au extraction with aqua regia, following the method described by Terashima (1988). Preliminary results show that, for equivalent Si02 contents, adakites are systematically enriched in Au compared to regular dacites, even if regional trends also exist. Moreover, Au seems to behave as an incompatible element in adakitic magmas, whereas in calc-alkaline dacites it is controlled by sulfide crystallization. Our data suggest that, not excluding any other processes related to the hydrothermal phase in the deposit generation, adakites may indeed represent the source of Au, a possible explanation for the adakite-Au deposit association.

76 FR 16235 - Corporate Credit Unions, Technical Corrections

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-23

... NATIONAL CREDIT UNION ADMINISTRATION 12 CFR Part 707 RIN 3133-AD58 Corporate Credit Unions... 2010, NCUA issued technical corrections to its corporate credit union rule, published in the Federal... October 2010, NCUA published a comprehensive overhaul to its corporate credit union rule, 12 CFR part 704...

Bone fragment union and remodeling after arthroscopic bony bankart repair for traumatic anterior shoulder instability with a glenoid defect: influence on postoperative recurrence of instability.

PubMed

Nakagawa, Shigeto; Ozaki, Ritsuro; Take, Yasuhiro; Mae, Tatsuo; Hayashida, Kenji

2015-06-01

Although good clinical outcomes have been reported after arthroscopic bony Bankart repair, the extent of bone union is still unclear. To investigate bone union after arthroscopic bony Bankart repair and its influence on postoperative recurrence of instability. Cohort study; Level of evidence, 3. Among 113 consecutive shoulders that underwent arthroscopic bony Bankart repair, postoperative evaluation of bone union by computed tomography (CT) was performed at various times in 81 shoulders. Bone union was investigated during 3 periods: 3 to 6 months postoperatively (first period), 7 to 12 months postoperatively (second period), and 13 months or more postoperatively (third period). The influence of the size of the preoperative glenoid defect and the size of the bone fragment on bone union was investigated, as well as the influence of bone union on postoperative recurrence of instability. In shoulders with bone union, bone fragment remodeling and changes in the glenoid defect size were also investigated. The bone union rate was 30.5% in the first period, 55.3% in the second period, and 84.6% in the third period. Among 53 shoulders with CT evaluation in the second period or later and follow-up for a minimum of 1 year, there was complete union in 33 shoulders (62.3%), partial union in 3 (5.7%), nonunion in 8 (15.1%), and no fragment on CT in 9 (17.0%). The complete union rate was 50% for 22 shoulders with small bone fragments (<5% of the glenoid diameter), 56.3% for 16 shoulders with medium fragments (5%-10%), and 86.7% for 15 shoulders with large fragments (>10%). The recurrence rate for postoperative instability was only 6.1% for shoulders with complete union, while it was 50% for shoulders with partial union, nonunion, no fragment, and no fragment on CT. The recurrence rate was significantly higher (36.4%) in shoulders with small fragments, but it was significantly lower in shoulders with bone union. In shoulders with bone union, the bone fragment frequently became larger over time, while the size of the glenoid defect decreased significantly from 18.6% preoperatively to 4.7% postoperatively. Bone union was not always achieved after arthroscopic bony Bankart repair, and union was often delayed. Recurrence of instability was significantly more frequent when bone union failed. The size of the glenoid defect decreased significantly in shoulders with bone union. © 2015 The Author(s).

Evidence of significant covalent bonding in Au(CN)(2)(-).

PubMed

Wang, Xue-Bin; Wang, Yi-Lei; Yang, Jie; Xing, Xiao-Peng; Li, Jun; Wang, Lai-Sheng

2009-11-18

The Au(CN)(2)(-) ion is the most stable Au compound known for centuries, yet a detailed understanding of its chemical bonding is still lacking. Here we report direct experimental evidence of significant covalent bonding character in the Au-C bonds in Au(CN)(2)(-) using photoelectron spectroscopy and comparisons with its lighter congeners, Ag(CN)(2)(-) and Cu(CN)(2)(-). Vibrational progressions in the Au-C stretching mode were observed for all detachment transitions for Au(CN)(2)(-), in contrast to the atomic-like transitions for Cu(CN)(2)(-), revealing the Au-C covalent bonding character. In addition, rich electronic structural information was obtained for Au(CN)(2)(-) by employing 118 nm detachment photons. Density functional theory and high-level ab initio calculations were carried out to understand the photoelectron spectra and obtain insight into the nature of the chemical bonding in the M(CN)(2)(-) complexes. Significant covalent character in the Au-C bonding due to the strong relativistic effects was revealed in Au(CN)(2)(-), consistent with its high stability.

Homoepitaxial electrodeposition on reconstructed and unreconstructed Au(100): An in-situ STM study

NASA Astrophysics Data System (ADS)

Al-Shakran, Mohammad; Kibler, Ludwig A.; Jacob, Timo

2015-01-01

A study of homoepitaxial electrodeposition on reconstructed and unreconstructed Au(100) surfaces is presented. The growth behavior has been investigated by in-situ scanning tunneling microscopy for Au(100) in contact with 0.1 M H2SO4 + 5 μM K[AuCl4]. It is shown that the initial surface structure is decisive for the emerging Au structures, giving rise to clearly different surface morphologies for electro-crystallization of Au on the unreconstructed and on the reconstructed Au(100) surface. A layer-by-layer growth is observed at more positive potentials for unreconstructed Au(100). The electrodeposition proceeds initially by the formation of Au islands followed by island coalescence due to the high mobility of surface atoms. Monatomic recessed stripes are formed as a result of the coalescence of deposited Au islands. At more negative potentials, the growth of Au proceeds strongly anisotropic on the reconstructed surface by the formation of reconstructed elongated islands.

Fermi surfaces properties of AuAl2, AuGa2, and AuIn2 with the CaF2-type cubic structure

NASA Astrophysics Data System (ADS)

Nishimura, K.; Kakihana, M.; Suzuki, F.; Yara, T.; Hedo, M.; Nakama, T.; Ōnuki, Y.; Harima, H.

2018-05-01

We grew high-quality single crystals of AuAl2, AuGa2, and AuIn2 with the fluorite (CaF2)-type cubic structure and determined the Fermi surface properties by the de Haas-van Alphen (dHvA) experiments using full-potential LAPW bad calculations. The Fermi surface and optical properties for three compounds were once studied from an interest of colors because AuAl2 has a striking bright reddish-purple color, whereas AuGa2 and AuIn2 are, respectively, neutral and bluish. The detected dHvA frequencies in the present study are found to be in a wide range of (0.1-13)×107 Oe. The main dHvA branches for three compounds are in excellent agreement with the theoretical ones, but some dHvA branches with small dHvA frequencies are slightly deviated from the theoretical ones, especially in AuGa2 and AuIn2.

Layered double hydroxide supported gold nanoclusters by glutathione-capped Au nanoclusters precursor method for highly efficient aerobic oxidation of alcohols.

PubMed

Li, Lun; Dou, Liguang; Zhang, Hui

2014-04-07

M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 ± 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ∼0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h(-1)) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au-support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen.

In Situ Reductive Synthesis of Structural Supported Gold Nanorods in Porous Silicon Particles for Multifunctional Nanovectors.

PubMed

Zhu, Guixian; Liu, Jen-Tsai; Wang, Yuzhen; Zhang, Dechen; Guo, Yi; Tasciotti, Ennio; Hu, Zhongbo; Liu, Xuewu

2016-05-11

Porous silicon nanodisks (PSD) were fabricated by the combination of photolithography and electrochemical etching of silicon. By using PSD as a reducing agent, gold nanorods (AuNR) were in situ synthesized in the nanopores of PSD, forming PSD-supported-AuNR (PSD/AuNR) hybrid particles. The formation mechanism of AuNR in porous silicon (pSi) was revealed by exploring the role of pSi reducibility and each chemical in the reaction. With the PSD support, AuNR exhibited a stable morphology without toxic surface ligands (CTAB). The PSD/AuNR hybrid particles showed enhanced plasmonic property compared to free AuNR. Because high-density "hot spots" can be generated by controlling the distribution of AuNR supported in PSD, surface-enhanced raman scattering (SERS) using PSD/AuNR as particle substrates was demonstrated. A multifunctional vector, PSD/AuNR/DOX, composed of doxorubicin (DOX)-loaded PSD/AuNR capped with agarose (agar), was developed for highly efficient, combinatorial cancer treatment. Their therapeutic efficacy was examined using two pancreatic cancer cell lines, PANC-1 and MIA PaCa-2. PSD/AuNR/DOX (20 μg Au and 1.25 μg DOX/mL) effectively destroyed these cells under near-IR laser irradiation (810 nm, 15 J·cm(-2) power, 90 s). Overall, we envision that PSD/AuNR may be a promising injectable, multifunctional nanovector for biomedical application.

State of the Unions

ERIC Educational Resources Information Center

Blair, Julie

2004-01-01

This article discusses the corrupt leadership of two big-city teachers' unions, the Washington Teachers Union (WTU) and its Miami cousin, United Teachers of Dade (UTD), that took both unions to the brink of despair and financial ruin. While the feds were rifling through union files to build extensive criminal investigations, congress called Sandra…

12 CFR 708b.105 - Approval of merger proposal by the NCUA.

Code of Federal Regulations, 2010 CFR

2010-01-01

....105 Section 708b.105 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS MERGERS OF FEDERALLY-INSURED CREDIT UNIONS; VOLUNTARY TERMINATION OR CONVERSION OF INSURED... credit union is federally-insured and the merging credit union is nonfederally-insured or uninsured, the...

12 CFR 708b.302 - Conversion of Insurance (Federal Credit Union).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Conversion of Insurance (Federal Credit Union... CREDIT UNIONS MERGERS OF FEDERALLY-INSURED CREDIT UNIONS; VOLUNTARY TERMINATION OR CONVERSION OF INSURED STATUS Forms § 708b.302 Conversion of Insurance (Federal Credit Union). Unless the Regional Director...

12 CFR 708b.302 - Conversion of insurance (Federal Credit Union).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Conversion of insurance (Federal Credit Union... CREDIT UNIONS MERGERS OF FEDERALLY-INSURED CREDIT UNIONS; VOLUNTARY TERMINATION OR CONVERSION OF INSURED STATUS Forms § 708b.302 Conversion of insurance (Federal Credit Union). Unless the Regional Director...

Compulsory Unionism, the NLRB, and the Courts: A Legal Analysis of Union Security Agreements. Labor Relations and Public Policy Series Report No. 15.

ERIC Educational Resources Information Center

Haggard, Thomas R.

As used here, compulsory union or union security agreements are federally sanctioned contracts between a labor union and employer whereby the employer agrees to require his employees, as a condition of their employment, to affiliate with the union in some way. Right-to-work is usually construed to mean the liberty of the individual to have a job…

Compound formation and superconductivity in Au-Si: X-ray absorption measurements on ion-beam-mixed Au-Si films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeon, Y.; Jisrawi, N.; Liang, G.

Multilayered Au-Si thin films have been deposited with the net compositions ''Au/sub 1-//sub x/Si/sub x/,'' x = 0.29, 0.5, and 0.8. After ion-beam mixing these films exhibited superconductivity in the 0.3--1.2 K range despite the nonsuperconducting character of both Au and Si. Near-edge x-ray absorption spectroscopy (XAS) measurements on the Au L/sub 3/ edge in these films indicate that metastable Au-Si compound formation occurs in these ion-mixed materials. Specifically, the XAS measurements indicate changes in Au 5d-orbital occupancy and changes in the local Au structural environment which are both consistent with local compound formation.

75 FR 64785 - Corporate Credit Unions

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

...NCUA is issuing final amendments to its rule governing corporate credit unions. The major revisions involve corporate credit union capital, investments, asset-liability management, governance, and credit union service organization (CUSO) activities. The amendments establish a new capital scheme, including risk-based capital requirements; impose new prompt corrective action requirements; place various new limits on corporate investments; impose new asset-liability management controls; amend some corporate governance provisions; and limit a corporate CUSO to categories of services preapproved by NCUA. In addition, this rulemaking contains conforming amendments to rules governing Prompt Corrective Action (for natural person credit unions); Investments and Deposit Activities (for federal credit unions); Administrative Actions, Adjudicative Hearings, Rules of Practice and Procedure, and Investigations; and Involuntary Liquidation of Federal Credit Unions and Adjudication of Creditor Claims Involving Federally Insured Credit Unions. These amendments will strengthen individual corporates and the corporate credit union system as a whole.

Glucose-functionalized Au nanoprisms for optoacoustic imaging and near-infrared photothermal therapy

NASA Astrophysics Data System (ADS)

Han, Jishu; Zhang, Jingjing; Yang, Meng; Cui, Daxiang; de La Fuente, Jesus M.

2015-12-01

Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through photothermal therapy. The current work demonstrates the great potential of Au@PEG-Glc NPrs in optoacoustic imaging and photothermal cancer therapy in future.Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through photothermal therapy. The current work demonstrates the great potential of Au@PEG-Glc NPrs in optoacoustic imaging and photothermal cancer therapy in future. Electronic supplementary information (ESI) available: The evolution of the UV-vis absorption of Au NPrs by centrifugation, TEM image of PEG-capped Au NPrs, the UV-vis absorption of glucose, cytotoxicity of Au@PEG-Glc NPrs, gastric cell viabilities versus the concentration of Au@PEG-Glc NPrs and gastric cell viabilities filled with 80 μg Au@PEG-Glc NPrs versus the irradiation time, optoacoustic signals of Au NPr solution and Au@PEG NPrs. See DOI: 10.1039/c5nr06261f

Synthesis of Au38(SCH2CH2Ph)24, Au36(SPh-tBu)24, and Au30(S-tBu)18 Nanomolecules from a Common Precursor Mixture.

PubMed

Rambukwella, Milan; Dass, Amala

2017-10-17

Phenylethanethiol protected nanomolecules such as Au 25 , Au 38 , and Au 144 are widely studied by a broad range of scientists in the community, owing primarily to the availability of simple synthetic protocols. However, synthetic methods are not available for other ligands, such as aromatic thiol and bulky ligands, impeding progress. Here we report the facile synthesis of three distinct nanomolecules, Au 38 (SCH 2 CH 2 Ph) 24 , Au 36 (SPh-tBu) 24 , and Au 30 (S-tBu) 18 , exclusively, starting from a common Au n (glutathione) m (where n and m are number of gold atoms and glutathiolate ligands) starting material upon reaction with HSCH 2 CH 2 Ph, HSPh-tBu, and HStBu, respectively. The systematic synthetic approach involves two steps: (i) synthesis of kinetically controlled Au n (glutathione) m crude nanocluster mixture with 1:4 gold to thiol molar ratio and (ii) thermochemical treatment of the purified nanocluster mixture with excess thiols to obtain thermodynamically stable nanomolecules. Thermochemical reactions with physicochemically different ligands formed highly monodispersed, exclusively three different core-size nanomolecules, suggesting a ligand induced core-size conversion and structural transformation. The purpose of this work is to make available a facile and simple synthetic method for the preparation of Au 38 (SCH 2 CH 2 Ph) 24 , Au 36 (SPh-tBu) 24 , and Au 30 (S-tBu) 18 , to nonspecialists and the broader scientific community. The central idea of simple synthetic method was demonstrated with other ligand systems such as cyclopentanethiol (HSC 5 H 9 ), cyclohexanethiol(HSC 6 H 11 ), para-methylbenzenethiol(pMBT), 1-pentanethiol(HSC 5 H 11 ), 1-hexanethiol(HSC 6 H 13 ), where Au 36 (SC 5 H 9 ) 24 , Au 36 (SC 6 H 11 ) 24 , Au 36 (pMBT) 24 , Au 38 (SC 5 H 11 ) 24 , and Au 38 (SC 6 H 13 ) 24 were obtained, respectively.

Architecture of Pd-Au bimetallic nanoparticles in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles as investigated by X-ray absorption spectroscopy.

PubMed

Chen, Ching-Hsiang; Sarma, Loka Subramanyam; Chen, Jium-Ming; Shih, Shou-Chu; Wang, Guo-Rung; Liu, Din-Goa; Tang, Mau-Tsu; Lee, Jyh-Fu; Hwang, Bing-Joe

2007-09-01

In this study, we demonstrate the unique application of X-ray absorption spectroscopy (XAS) as a fundamental characterization tool to help in designing and controlling the architecture of Pd-Au bimetallic nanoparticles within a water-in-oil microemulsion system of water/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/n-heptane. Structural insights obtained from the in situ XAS measurements recorded at each step during the formation process revealed that Pd-Au bimetallic clusters with various Pd-Au atomic stackings are formed by properly performing hydrazine reduction and redox transmetalation reactions sequentially within water-in-oil microemulsions. A structural model is provided to explain reasonably each reaction step and to give detailed insight into the nucleation and growth mechanism of Pd-Au bimetallic clusters. The combination of in situ XAS analysis at both the Pd K-edge and the Au L(III)-edge and UV-vis absorption spectral features confirms that the formation of Pd-Au bimetallic clusters follows a (Pd(nuclei)-Au(stack))-Pd(surf) stacking. This result further implies that the thickness of Au(stack) and Pd(surf) layers may be modulated by varying the dosage of the Au precursor and hydrazine, respectively. In addition, a bimetallic (Pd-Au)(alloy) nanocluster with a (Pd(nuclei)-Au(stack))-(Pd-Au(alloy))(surf) stacking was also designed and synthesized in order to check the feasibility of Pd(surf) layer modification. The result reveals that the Pd(surf) layer of the stacked (Pd(nuclei)-Au)(stack) bimetallic clusters can be successfully modified to form a (Au-Pd alloy)(surf) layer by a co-reduction of Pd and Au ions by hydrazine. Further, we demonstrate the alloying extent or atomic distribution of Pd and Au in Pd-Au bimetallic nanoparticles from the derived XAS structural parameters. The complete XAS-based methodology, demonstrated here on the Pd-Au bimetallic system, can easily be extended to design and control the alloying extent or atomic distribution, atomic stacking, and electronic structure to construct many other types of bimetallic systems for interesting applications.

Light-controlled synthesis of gold nanoparticles using a rigid, photoresponsive surfactant

NASA Astrophysics Data System (ADS)

Huang, Youju; Kim, Dong-Hwan

2012-09-01

We report a new strategy for shape control over the synthesis of gold nanoparticles (AuNPs) by using a photoresponsive surfactant based on a modified seed growth method. Owing to photoresponsive properties of the azo group, the designed surfactant, N1,N3,N5-tris[(4'-azobenzene-4-sulphonic acid)phenyl]benzene-1,3,5-tricarboxamide, exhibits a distinctive molecular configuration under light leading to different growth processes of AuNPs. As a result, the blackberry-like, spherical AuNPs and multilayered Au plates were successfully prepared in high yield under visible and UV light. The size and morphological control of Au nanocrystals are described and the synthesized Au nanocrystals are evaluated for SERS applications.We report a new strategy for shape control over the synthesis of gold nanoparticles (AuNPs) by using a photoresponsive surfactant based on a modified seed growth method. Owing to photoresponsive properties of the azo group, the designed surfactant, N1,N3,N5-tris[(4'-azobenzene-4-sulphonic acid)phenyl]benzene-1,3,5-tricarboxamide, exhibits a distinctive molecular configuration under light leading to different growth processes of AuNPs. As a result, the blackberry-like, spherical AuNPs and multilayered Au plates were successfully prepared in high yield under visible and UV light. The size and morphological control of Au nanocrystals are described and the synthesized Au nanocrystals are evaluated for SERS applications. Electronic supplementary information (ESI) available: The UV-vis spectra, representative field-emission scanning electron microscopy (FESEM) images and size distributions of Au seeds (18 nm) and spherical AuNPs (50 nm), photograph images of AuNPs solution and TEM images of blackberry-like AuNPs. See DOI: 10.1039/c2nr31717f

Ultrastable BSA-capped gold nanoclusters with a polymer-like shielding layer against reactive oxygen species in living cells

NASA Astrophysics Data System (ADS)

Zhou, Wenjuan; Cao, Yuqing; Sui, Dandan; Guan, Weijiang; Lu, Chao; Xie, Jianping

2016-05-01

The prevalence of reactive oxygen species (ROS) production and the enzyme-containing intracellular environment could lead to the fluorescence quenching of bovine serum albumin (BSA)-capped gold nanoclusters (AuNCs). Here we report an efficient strategy to address this issue, where a polymer-like shielding layer is designed to wrap around the Au core to significantly improve the stability of AuNCs against ROS and protease degradation. The key of our design is to covalently incorporate a thiolated AuNC into the BSA-AuNC via carbodiimide-activated coupling, leading to the formation of a AuNC pair inside the cross-linked BSA molecule. The as-designed paired AuNCs in BSA (or BSA-p-AuNCs for short) show improved performances in living cells.The prevalence of reactive oxygen species (ROS) production and the enzyme-containing intracellular environment could lead to the fluorescence quenching of bovine serum albumin (BSA)-capped gold nanoclusters (AuNCs). Here we report an efficient strategy to address this issue, where a polymer-like shielding layer is designed to wrap around the Au core to significantly improve the stability of AuNCs against ROS and protease degradation. The key of our design is to covalently incorporate a thiolated AuNC into the BSA-AuNC via carbodiimide-activated coupling, leading to the formation of a AuNC pair inside the cross-linked BSA molecule. The as-designed paired AuNCs in BSA (or BSA-p-AuNCs for short) show improved performances in living cells. Electronic supplementary information (ESI) available: Detailed experimental materials, apparatus, experimental procedures and characterization data. See DOI: 10.1039/c6nr02178f

Electronic Absorption and MCD Spectra for Pd(AuPPh(3))(8)(2+), Pt(AuPPh(3))(8)(2+), and Related Platinum-Centered Gold Cluster Complexes.

PubMed

Adrowski, Michael J.; Mason, W. Roy

1997-03-26

Electronic absorption and 7.0 T magnetic circular dichroism (MCD) spectra in the UV-vis region, 1.6 to approximately 4.0 &mgr;m(-)(1) (1 &mgr;m(-)(1) = 10(4) cm(-)(1)) are reported for [Pd(AuPPh(3))(8)](NO(3))(2) and [Pt(AuPPh(3))(8)](NO(3))(2) in acetonitrile solutions at room temperature. The MCD spectra are better resolved than the absorption spectra and consist of both A and B terms. The spectra are interpreted in terms of D(4)(d)() skeletal geometry and MO's that are approximated by 5s and 6s orbitals for Pd and Pt/Au atoms, respectively. The lowest energy excited configurations and states are attributed to intraframework (IF) Au(8)(2+) transitions. Evidence is also presented for Pt 5d --> Au 6s transitions in the MCD spectra for Pt(AuPPh(3))(8)(2+). Acetonitrile solution absorption and MCD spectra for the related Pt-centered cluster complexes [Pt(CO)(AuPPh(3))(8)](NO(3))(2), [Pt(AuP(p-tolyl)(3))(8)](NO(3))(2), [Pt(CuCl)(AuPPh(3))(8)](NO(3))(2), [Pt(AgNO(3))(AuPPh(3))(8)](NO(3))(2), [Pt(Hg)(2)(AuPPh(3))(8)](NO(3))(2), [Pt(HgCl)(2)(AuPPh(3))(8)](BF(4))(2), and [Pt(HgNO(3))(2)(AuPPh(3))(8)](BF(4))(2) are also reported and interpreted within the context of the model developed for the M(AuPPh(3))(8)(2+) complexes.

Synergetic approach for simple and rapid conjugation of gold nanoparticles with oligonucleotides.

PubMed

Li, Jiuxing; Zhu, Binqing; Yao, Xiujie; Zhang, Yicong; Zhu, Zhi; Tu, Song; Jia, Shasha; Liu, Rudi; Kang, Huaizhi; Yang, Chaoyong James

2014-10-08

Attaching thiolated DNA on gold nanoparticles (AuNPs) has been extremely important in nanobiotechnology because DNA-AuNPs combine the programmability and molecular recognition properties of the biopolymers with the optical, thermal, and catalytic properties of the inorganic nanomaterials. However, current standard protocols to attach thiolated DNA on AuNPs involve time-consuming, tedious steps and do not perform well for large AuNPs, thereby greatly restricting applications of DNA-AuNPs. Here we demonstrate a rapid and facile strategy to attach thiolated DNA on AuNPs based on the excellent stabilization effect of mPEG-SH on AuNPs. AuNPs are first protected by mPEG-SH in the presence of Tween 20, which results in excellent stability of AuNPs in high ionic strength environments and extreme pHs. A high concentration of NaCl can be applied to the mixture of DNA and AuNP directly, allowing highly efficient DNA attachment to the AuNP surface by minimizing electrostatic repulsion. The entire DNA loading process can be completed in 1.5 h with only a few simple steps. DNA-loaded AuNPs are stable for more than 2 weeks at room temperature, and they can precisely hybridize with the complementary sequence, which was applied to prepare core-satellite nanostructures. Moreover, cytotoxicity assay confirmed that the DNA-AuNPs synthesized by this method exhibit lower cytotoxicity than those prepared by current standard methods. The proposed method provides a new way to stabilize AuNPs for rapid and facile loading thiolated DNA on AuNPs and will find wide applications in many areas requiring DNA-AuNPs, including diagnosis, therapy, and imaging.

Crystal Structure of Faradaurate-279: Au279(SPh-tBu)84 Plasmonic Nanocrystal Molecules.

PubMed

Sakthivel, Naga Arjun; Theivendran, Shevanuja; Ganeshraj, Vigneshraja; Oliver, Allen G; Dass, Amala

2017-11-01

We report the discovery of an unprecedentedly large, 2.2 nm diameter, thiolate protected gold nanocrystal characterized by single crystal X-ray crystallography (sc-XRD), Au 279 (SPh-tBu) 84 named Faradaurate-279 (F-279) in honor of Michael Faraday's (1857) pioneering work on nanoparticles. F-279 nanocrystal has a core-shell structure containing a truncated octahedral core with bulk face-centered cubic-like arrangement, yet a nanomolecule with a precise number of metal atoms and thiolate ligands. The Au 279 S 84 geometry was established from a low-temperature 120 K sc-XRD study at 0.90 Å resolution. The atom counts in core-shell structure of Au 279 follows the mathematical formula for magic number shells: Au@Au 12 @Au 42 @Au 92 @Au 54 , which is further protected by a final shell of Au 48 . Au 249 core is protected by three types of staple motifs, namely: 30 bridging, 18 monomeric, and 6 dimeric staple motifs. Despite the presence of such diverse staple motifs, Au 279 S 84 structure has a chiral pseudo-D 3 symmetry. The core-shell structure can be viewed as nested, concentric polyhedra, containing a total of five forms of Archimedean solids. A comparison between the Au 279 and Au 309 cuboctahedral superatom model in shell-wise growth is illustrated. F-279 can be synthesized and isolated in high purity in milligram quantities using size exclusion chromatography, as evidenced by mass spectrometry. Electrospray ionization-mass spectrometry independently verifies the X-ray diffraction study based heavy atoms formula, Au 279 S 84 , and establishes the molecular formula with the complete ligands, namely, Au 279 (SPh-tBu) 84 . It is also the smallest gold nanocrystal to exhibit metallic behavior, with a surface plasmon resonance band around 510 nm.

Size-induced chemical and magnetic ordering in individual Fe-Au nanoparticles.

PubMed

Mukherjee, Pinaki; Manchanda, Priyanka; Kumar, Pankaj; Zhou, Lin; Kramer, Matthew J; Kashyap, Arti; Skomski, Ralph; Sellmyer, David; Shield, Jeffrey E

2014-08-26

Formation of chemically ordered compounds of Fe and Au is inhibited in bulk materials due to their limited mutual solubility. However, here we report the formation of chemically ordered L12-type Fe3Au and FeAu3 compounds in Fe-Au sub-10 nm nanoparticles, suggesting that they are equilibrium structures in size-constrained systems. The stability of these L12-ordered Fe3Au and FeAu3 compounds along with a previously discovered L10-ordered FeAu has been explained by a size-dependent equilibrium thermodynamic model. Furthermore, the spin ordering of these three compounds has been computed using ab initio first-principle calculations. All ordered compounds exhibit a substantial magnetization at room temperature. The Fe3Au had a high saturation magnetization of about 143.6 emu/g with a ferromagnetic spin structure. The FeAu3 nanoparticles displayed a low saturation magnetization of about 11 emu/g. This suggests a antiferromagnetic spin structure, with the net magnetization arising from uncompensated surface spins. First-principle calculations using the Vienna ab initio simulation package (VASP) indicate that ferromagnetic ordering is energetically most stable in Fe3Au, while antiferromagnetic order is predicted in FeAu and FeAu3, consistent with the experimental results.

Au-rich filamentary behavior and associated subband gap optical absorption in hyperdoped Si

NASA Astrophysics Data System (ADS)

Yang, W.; Akey, A. J.; Smillie, L. A.; Mailoa, J. P.; Johnson, B. C.; McCallum, J. C.; Macdonald, D.; Buonassisi, T.; Aziz, M. J.; Williams, J. S.

2017-12-01

Au-hyperdoped Si, synthesized by ion implantation and pulsed laser melting, is known to exhibit a strong sub-band gap photoresponse that scales monotonically with the Au concentration. However, there is thought to be a limit to this behavior since ultrahigh Au concentrations (>1 ×1020c m-3 ) are expected to induce cellular breakdown during the rapid resolidification of Si, a process that is associated with significant lateral impurity precipitation. This work shows that the cellular morphology observed in Au-hyperdoped Si differs from that in conventional, steady-state cellular breakdown. In particular, Rutherford backscattering spectrometry combined with channeling and transmission electron microscopy revealed an inhomogeneous Au distribution and a subsurface network of Au-rich filaments, within which the Au impurities largely reside on substitutional positions in the crystalline Si lattice, at concentrations as high as ˜3 at. %. The measured substitutional Au dose, regardless of the presence of Au-rich filaments, correlates strongly with the sub-band gap optical absorptance. Upon subsequent thermal treatment, the supersaturated Au forms precipitates, while the Au substitutionality and the sub-band gap optical absorption both decrease. These results offer insight into a metastable filamentary regime in Au-hyperdoped Si that has important implications for Si-based infrared optoelectronics.

Bi-functional Au/FeS (Au/Co3O4) composite for in situ SERS monitoring and degradation of organic pollutants

NASA Astrophysics Data System (ADS)

Ma, Shuzhen; Cai, Qian; Lu, Kailing; Liao, Fan; Shao, Mingwang

2016-01-01

The bi-functional Au/FeS (Au/Co3O4) composite was fabricated by in situ reducing Au nanoparticles onto the surface of FeS (Co3O4). The as-prepared FeS possessed a multi-structure composed of plenty of nanoplates, which were coated by Au nanoparticles with an average size of 47.5 nm. While the Co3O4 showed a thin hexagonal sheet containing Au nanoparticles on its surface with an average size of 79.0 nm. Both the as-prepared Au/FeS and Au/Co3O4 composites exhibited excellent SERS performance, capable of enhancing the Raman signals of R6G molecules with the enhancement factor up to 1.81 × 106 and 7.60 × 104, respectively. Moreover, Au/FeS (Au/Co3O4) composite also has been verified to have intrinsic peroxidase-like activity, which could decompose H2O2 into hydroxyl radicals and then degrade organic pollutants into small molecules. Therefore, SERS can be used to real-time and in situ monitoring the degradation process of R6G molecules, employing the Au/FeS (Au/Co3O4) composite both as SERS substrate and catalyst.

Electron flow in large metallomacromolecules and electronic switch of nanoparticle stabilization: new click ferrocenyl dentromers that reduce Au(III) to Au nanoparticles.

PubMed

Astruc, Didier; Wang, Qi; Fu, Fangyu; Martinez-Villacorta, Angel M; Moya, Sergio; Salmon, Lionel; Ruiz, Jaime; Hunel, Julien; Vax, Amélie

2018-06-04

Click ferrocenyl-terminal dentromers, a family of arene-cored dendrimers with triple branching (9-Fc, 27-Fc, 81-Fc and 243-Fc) reduce Au(III) to ferricinium dentromer-stabilized Au nanoparticles (AuNPs). Cyclic voltammetry studies in CH2Cl2 show reversible CV waves with some adsorption for the 243-Fc dentromer and a number of redox groups found, 255 ± 25, using the Bard-Anson method, close to the theoretical number of 243. The dentromers reduce aqueous HAuCl4 to water-soluble ferricinium chloride dentromer-stabilized gold nanoparticles (AuNPs) with core sizes between 30 and 47 nm. These triazolylferricinium dentromer-stabilized AuNPs are reduced by cobaltocene to cobalticinium chloride and ferrocene dentromer-weakly stabilized AuNPs together with red shift of the AuNP plasmon. The weakness of the AuNP stabilization is characterized by dentromer extraction with CH2Cl2 along with irreversible AuNP agglomeration for the 9, 27 and 81-ferrocenyl dentromer, only the 243-ferrocenyl dentromer-AuNP withstanding this process. Altogether this demonstrates the electronic switch of the dentromer-mediated AuNP stabilization. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlling Au Nanorod Dispersion in Thin Film Polymer Blends

NASA Astrophysics Data System (ADS)

Hore, Michael J. A.; Composto, Russell J.

2012-02-01

Dispersion of Au nanorods (Au NRs) in polymer thin films is studied using a combination of experimental and theoretical techniques. Here, we incorporate small volume fractions of polystyrene-functionalized Au NRs (φrod 0.05) into polystyrene (PS) thin films. By controlling the ratio of the brush length (N) to that of the matrix polymers (P), we can selectively obtain dispersed or aggregated Au NR structures in the PS-Au(N):PS(P) films. A dispersion map of these structures allows one to choose N and P to obtain either uniformly dispersed Au NRs or aggregates of closely packed, side-by-side aligned Au NRs. Furthermore, by blending poly(2,6-dimethyl-p-phenylene oxide) (PPO) into the PS films, we demonstrate that the Au nanorod morphology can be further tuned by reducing depletion-attraction forces and promoting miscibility of the Au NRs. These predictable structures ultimately give rise to tunable optical absorption in the films resulting from surface plasmon resonance coupling between the Au NRs. Finally, self-consistent field theoretic (SCFT) calculations for both the PS-Au(N):PS(P) and PS-Au(N):PS(P):PPO systems provide insight into the PS brush structure, and allow us to interpret morphology and optical property results in terms of wet and dry PS brush states.

Au–CsPbBr 3 Hybrid Architecture: Anchoring Gold Nanoparticles on Cubic Perovskite Nanocrystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balakrishnan, Subila K.; Kamat, Prashant V.

A selective growth of gold (Au) nanoparticles on the corners of CsPbBr 3 nanocrystals (NCs) is made possible with the treatment of Au(III) salts such as Au(III) bromide and Au(III) chloride in solution. The surface bound oleylamine ligands not only stabilize NCs but also facilitate reduction of the Au(III) salts followed by nucleation of the Au nanoparticles on the corners of the perovskite NCs. The luminescence quantum yield of NCs is decreased when Au nanoparticles are formed on the corners of CsPbBr 3 NCs, suggesting interaction between the two systems. Formation of Au nanoparticles as well as an anion exchangemore » is seen when Au(III) bromide was replaced with Au(III) chloride as a precursor. This simple strategy of designing perovskite-gold hybrid nanostructures with good colloidal stability offers new opportunities to explore their photocatalytic properties.« less

A theoretical study of the decomposition of gold (I) complexes

NASA Astrophysics Data System (ADS)

Tossell, J. A.

1998-04-01

Structures, energetics and excitation energies are calculated for the gold (I) complexes CH 3Au, (CH 3) 2Au -, CH 3AuOH 2, CH 3AuPH 3 and PH 3AuCl at the Hartree-Fock and MP2 levels of theory, and for CH 3AuP(CH 3) 3, CH 3AuP(OH) 3 and Au 3Cl 3 at the HF level. The lowest-energy neutral triplet state of each 2-coordinate compound dissociates into either two or three radical species (always including the CH 3 radical), with the exception of (CH 3) 2Au - which shows only slight Au-C bond elongation. In contrast, the doublet anion states dissociate neutral ligands, like PH 3, but do not dissociate CH 3. These results indicate that gold (I) chemical vapor deposition processes must involve excited states of the neutrals rather than their anions.

Identified particle distributions in pp and Au+Au collisions atsqrt sNN=200 GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, J.; Adler, C.; Aggarwal, M.M.

2003-10-06

Transverse mass and rapidity distributions for charged pions, charged kaons, protons and antiprotons are reported for {radical}sNN = 200 GeV pp and Au+Au collisions at RHIC. The transverse mass distributions are rapidity independent within |y| < 0.5, consistent with a boost-invariant system in this rapidity interval. Spectral shapes and relative particle yields are similar in pp and peripheral Au+Au collisions and change smoothly to central Au+Au collisions. No centrality dependence was observed in the kaon and antiproton production rates relative to the pion production rate from medium-central to central collisions. Chemical and kinetic equilibrium model fits to our data revealmore » strong radial flow and relatively long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.« less

Charged hadron transverse momentum distributions in Au+Au collisions at √sNN=200 GeV

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Lee, J. W.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2004-01-01

We present transverse momentum distributions of charged hadrons produced in Au+Au collisions at sNN=200 GeV. The spectra were measured for transverse momenta pT from 0.25 to 4.5 GeV/c in a pseudorapidity range of 0.2<η<1.4. The evolution of the spectra is studied as a function of collision centrality, from 65 to 344 participating nucleons. The results are compared to data from proton-antiproton collisions and Au+Au collisions at lower RHIC energies. We find a significant change of the spectral shape between proton-antiproton and semi-peripheral Au+Au collisions. Comparing semi-peripheral to central Au+Au collisions, we find that the yields at high pT exhibit approximate scaling with the number of participating nucleons, rather than scaling with the number of binary collisions.

An efficient synthetic method for organometallic radicals: structures and properties of gold(i)-(nitronyl nitroxide)-2-ide complexes.

PubMed

Suzuki, Shuichi; Kira, Sayaka; Kozaki, Masatoshi; Yamamura, Masaki; Hasegawa, Toru; Nabeshima, Tatsuya; Okada, Keiji

2017-02-21

One-pot synthesis of (nitronyl nitroxide)-gold(i)-phosphine (NN-Au-P) complexes has been developed using chloro(tetrahydrothiophene)gold(i), phosphine ligands, nitronyl nitroxide radicals, and sodium hydroxide. The NN-Au-P complexes can be easily handled because they were quite stable under aerated conditions in both solution and crystalline states. They showed weak absorption bands with vibrational structures in the 450-650 nm region. The oxidation potentials assigned to the NN moieties of NN-Au-P complexes with aromatic phosphines were observed around -0.1 V vs. Fc/Fc + (-0.11 V for NN-Au-1, -0.08 V for NN-Au-2, -0.13 V for NN-Au-5, and -0.07 V for NN-Au-6), somewhat lower than that of NN-Au-P complexes with aliphatic phosphines (-0.25 V for NN-Au-3 and -0.17 V for NN-Au-4).

AuRu/AC as an effective catalyst for hydrogenation reactions

DOE PAGES

Villa, Alberto; Chan-Thaw, Carine E.; Campisi, Sebastiano; ...

2015-03-23

AuRu bimetallic catalysts have been prepared by sequential deposition of Au on Ru or vice versa obtaining different nanostructures: when Ru has been deposited on Au, a Au core–Ru shell has been observed, whereas the deposition of Au on Ru leads to a bimetallic phase with Ru enrichment on the surface. In the latter case, the unexpected Ru enrichment could be attributed to the weak adhesion of Ru on the carbon support, thus allowing Ru particles to diffuse on Au particles. Both structures result very active in catalysing the liquid phase hydrogenolysis of glycerol and levulinic acid but the activity,more » the selectivity and the stability depend on the structure of the bimetallic nanoparticles. Ru@Au/AC core–shell structure mostly behaved as the monometallic Ru, whereas the presence of bimetallic AuRu phase in Au@Ru/AC provides a great beneficial effect on both activity and stability.« less

Au–CsPbBr 3 Hybrid Architecture: Anchoring Gold Nanoparticles on Cubic Perovskite Nanocrystals

DOE PAGES

Balakrishnan, Subila K.; Kamat, Prashant V.

2016-11-29

A selective growth of gold (Au) nanoparticles on the corners of CsPbBr 3 nanocrystals (NCs) is made possible with the treatment of Au(III) salts such as Au(III) bromide and Au(III) chloride in solution. The surface bound oleylamine ligands not only stabilize NCs but also facilitate reduction of the Au(III) salts followed by nucleation of the Au nanoparticles on the corners of the perovskite NCs. The luminescence quantum yield of NCs is decreased when Au nanoparticles are formed on the corners of CsPbBr 3 NCs, suggesting interaction between the two systems. Formation of Au nanoparticles as well as an anion exchangemore » is seen when Au(III) bromide was replaced with Au(III) chloride as a precursor. This simple strategy of designing perovskite-gold hybrid nanostructures with good colloidal stability offers new opportunities to explore their photocatalytic properties.« less

Synthesis, structure, and bonding in K12Au21Sn4. A polar intermetallic compound with dense Au20 and open AuSn4 layers.

PubMed

Li, Bin; Kim, Sung-Jin; Miller, Gordon J; Corbett, John D

2009-12-07

The new phase K(12)Au(21)Sn(4) has been synthesized by direct reaction of the elements at elevated temperatures. Single crystal X-ray diffraction established its orthorhombic structure, space group Pmmn (No. 59), a = 12.162(2); b = 18.058(4); c = 8.657(2) A, V = 1901.3(7) A(3), and Z = 2. The structure consists of infinite puckered sheets of vertex-sharing gold tetrahedra (Au(20)) that are tied together by thin layers of alternating four-bonded-Sn and -Au atoms (AuSn(4)). Remarkably, the dense but electron-poorer blocks of Au tetrahedra coexist with more open and saturated Au-Sn layers, which are fragments of a zinc blende type structure that maximize tetrahedral heteroatomic bonding outside of the network of gold tetrahedra. LMTO band structure calculations reveal metallic properties and a pseudogap at 256 valence electrons per formula unit, only three electrons fewer than in the title compound and at a point at which strong Au-Sn bonding is optimized. Additionally, the tight coordination of the Au framework atoms by K plays an important bonding role: each Au tetrahedra has 10 K neighbors and each K atom has 8-12 Au contacts. The appreciably different role of the p element Sn in this structure from that in the triel members in K(3)Au(5)In and Rb(2)Au(3)Tl appears to arise from its higher electron count which leads to better p-bonding (valence electron concentrations = 1.32 versus 1.22).

A general and high-yield galvanic displacement approach to Au-M (M = Au, Pd, and Pt) core-shell nanostructures with porous shells and enhanced electrocatalytic performances.

PubMed

Kuai, Long; Geng, Baoyou; Wang, Shaozhen; Sang, Yan

2012-07-23

In this work, we utilize the galvanic displacement synthesis and make it a general and efficient method for the preparation of Au-M (M = Au, Pd, and Pt) core-shell nanostructures with porous shells, which consist of multilayer nanoparticles. The method is generally applicable to the preparation of Au-Au, Au-Pd, and Au-Pt core-shell nanostructures with typical porous shells. Moreover, the Au-Au isomeric core-shell nanostructure is reported for the first time. The lower oxidation states of Au(I), Pd(II), and Pt(II) are supposed to contribute to the formation of porous core-shell nanostructures instead of yolk-shell nanostructures. The electrocatalytic ethanol oxidation and oxygen reduction reaction (ORR) performance of porous Au-Pd core-shell nanostructures are assessed as a typical example for the investigation of the advantages of the obtained core-shell nanostructures. As expected, the Au-Pd core-shell nanostructure indeed exhibits a significantly reduced overpotential (the peak potential is shifted in the positive direction by 44 mV and 32 mV), a much improved CO tolerance (I(f)/I(b) is 3.6 and 1.63 times higher), and an enhanced catalytic stability in comparison with Pd nanoparticles and Pt/C catalysts. Thus, porous Au-M (M = Au, Pd, and Pt) core-shell nanostructures may provide many opportunities in the fields of organic catalysis, direct alcohol fuel cells, surface-enhanced Raman scattering, and so forth. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoinduced Glycerol Oxidation over Plasmonic Au and AuM (M = Pt, Pd and Bi) Nanoparticle-Decorated TiO2 Photocatalysts

PubMed Central

Jedsukontorn, Trin; Saito, Nagahiro; Hunsom, Mali

2018-01-01

In this study, sol-immobilization was used to prepare gold nanoparticle (Au NP)-decorated titanium dioxide (TiO2) photocatalysts at different Au weight % (wt. %) loading (Aux/TiO2, where x is the Au wt. %) and Au–M NP-decorated TiO2 photocatalysts (Au3M3/TiO2), where M is bismuth (Bi), platinum (Pt) or palladium (Pd) at 3 wt. %. The Aux/TiO2 photocatalysts exhibited a stronger visible light absorption than the parent TiO2 due to the localized surface plasmon resonance effect. Increasing the Au content from 1 wt. % to 7 wt. % led to increased visible light absorption due to the increasing presence of defective structures that were capable of enhancing the photocatalytic activity of the as-prepared catalyst. The addition of Pt and Pd coupled with the Au3/TiO2 to form Au3M3/TiO2 improved the photocatalytic activity of the Au3/TiO2 photocatalyst by maximizing their light-absorption property. The Au3/TiO2, Au3Pt3/TiO2 and Au3Pd3/TiO2 photocatalysts promoted the formation of glyceraldehyde from glycerol as the principle product, while Au3Bi3/TiO2 facilitated glycolaldehyde formation as the major product. Among all the prepared photocatalysts, Au3Pd3/TiO2 exhibited the highest photocatalytic activity with a 98.75% glycerol conversion at 24 h of reaction time. PMID:29690645

Cationic gemini surfactant-assisted synthesis of hollow Au nanostructures by stepwise reductions.

PubMed

Wang, Wentao; Han, Yuchun; Tian, Maozhang; Fan, Yaxun; Tang, Yongqiang; Gao, Mingyuan; Wang, Yilin

2013-06-26

A novel synthetic approach was developed for creating versatile hollow Au nanostructures by stepwise reductions of Au(III) upon the use of cationic gemini surfactant hexamethylene-1,6-bis(dodecyl dimethylammonium bromide) (C12C6C12Br2) as a template agent. It was observed that the Au(I) ions obtained from the reduction of Au(III) by ascorbic acid can assist the gemini surfactant to form vesicles, capsule-like, and tube-like aggregates that subsequently act as soft templates for hollow Au nanostructures upon further reduction of Au(I) to Au(0) by NaBH4. It was demonstrated that the combination of C12C6C12Br2 and Au(I) plays a key role in regulating the structure of the hollow precursors not only because C12C6C12Br2 has a stronger aggregation ability in comparison with its single chain counterpart but also because the electrostatic repulsion between head groups of C12C6C12Br2 is greatly weakened after Au(III) is converted to Au(I), which is in favor of the construction of vesicles, capsule-like, and tube-like aggregates. Compared with solid Au nanospheres, the resultant hollow nanostructures exhibit enhanced electrocatalytic activities in methanol oxidation, following the order of elongated nanocapsule > nanocapsule > nanosphere. Benefiting from balanced interactions between the gemini surfactant and Au(I), this soft-template method may present a facile and versatile approach for the controlled synthesis of Au nanostructures potentially useful for fuel cells and other Au nanodevices.

A preliminary investigation of acousto-ultrasonic NDE of metal matrix composite test specimens

NASA Technical Reports Server (NTRS)

Kautz, Harold E.; Lerch, Brad A.

1991-01-01

Acousto-ultrasonic (AU) measurements were performed on a series of tensile specimens composed of 8 laminated layers of continuous, SiC fiber reinforced Ti-15-3 matrix. The following subject areas are covered: AU signal analysis; tensile behavior; AU and interrupted tensile tests; AU and thermally cycled specimens; AU and stiffness; and AU and specimen geometry.

The fabrication of nanopatterns with Au nanoparticles-embedded micelles via nanoimprint lithography.

PubMed

Lee, Jung-Pil; Kim, Eun-Uk; Koh, Haeng-Deog; Kang, Nam-Goo; Jung, Gun-Young; Lee, Jae-Suk

2009-09-09

We fabricated nanopatterns with Au nanoparticles-embedded micelles (Au-micelles) by self-assembly of block copolymers via nanoimprint lithography. The micelle structure prepared by self-assembled block copolymers was used as a template for the synthesis of Au nanoparticles (Au NPs). Au NPs were synthesized in situ inside the micelles of polystyrene-block-poly(2-vinylpyridine) (PS- b-P2VP). Au-micelles were arranged on the trenches of the polymer template, which was imprinted by nanoimprint lithography. The fabrication of line-type and dot-type nanopatterns was carried out by the combined method. In addition, multilayer nanopatterns of the Au-micelles were also proposed.

Distributions of charged hadrons associated with high transverse momentum particles in pp and Au+Au collisions at sqrt[sNN]=200 GeV.

PubMed

Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Ganti, M S; Gaudichet, L; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grebenyuk, O; Gronstal, S; Grosnick, D; Guertin, S M; Gupta, A; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Hughes, E; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Levine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mischke, A; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, D A; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; Vandermolen, A M; Varma, R; Vasilevski, I; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Vznuzdaev, M; Waggoner, W; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Yuting, B; Zanevski, Y V; Zhang, H; Zhang, W M; Zhang, Z P; Zhaomin, Z P; Zizong, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

2005-10-07

Charged hadrons in [EQUATION: SEE TEXT] associated with particles of [EQUATION: SEE TEXT] are reconstructed in pp and Au+Au collisions at sqrt[sNN]=200 GeV. The associated multiplicity and p magnitude sum are found to increase from pp to central Au+Au collisions. The associated p distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed.

Charged hadron transverse momentum distributions in Au+Au collisions at √ SNN = 200 GeV

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.; van Nieuwenhuizen, Gerrit; PHOBOS Collaboration

2003-04-01

We present transverse momentum distributions of charged hadrons produced in Au+Au collisions at √ SNN = 200 GeV. The evolution of the spectra for transverse momenta p T from 0.25 to 5 GeV/C is studied as a function of collision centrality. We find a significant change of the spectral shape between proton-antiproton and peripheral Au+Au collisions. When comparing peripheral to central Au+Au collisions, we find that the yields at the highest p T exhibit approximate scaling with the number of participating nucleons, rather than scaling with the number of binary collisions.

Plasmon enhanced water splitting mediated by hybrid bimetallic Au-Ag core-shell nanostructures.

PubMed

Erwin, William R; Coppola, Andrew; Zarick, Holly F; Arora, Poorva; Miller, Kevin J; Bardhan, Rizia

2014-11-07

In this work, we employed wet chemically synthesized bimetallic Au-Ag core-shell nanostructures (Au-AgNSs) to enhance the photocurrent density of mesoporous TiO2 for water splitting and we compared the results with monometallic Au nanoparticles (AuNPs). While Au-AgNSs incorporated photoanodes give rise to 14× enhancement in incident photon to charge carrier efficiency, AuNPs embedded photoanodes result in 6× enhancement. By varying nanoparticle concentration in the photoanodes, we observed ∼245× less Au-AgNSs are required relative to AuNPs to generate similar photocurrent enhancement for solar fuel conversion. Power-dependent measurements of Au-AgNSs and AuNPs showed a first order dependence to incident light intensity, relative to half-order dependence for TiO2 only photoanodes. This indicated that plasmonic nanostructures enhance charge carriers formed on the surface of the TiO2 which effectively participate in photochemical reactions. Our experiments and simulations suggest the enhanced near-field, far-field, and multipolar resonances of Au-AgNSs facilitating broadband absorption of solar radiation collectively gives rise to their superior performance in water splitting.

{331}-Faceted trisoctahedral gold nanocrystals: synthesis, superior electrocatalytic performance and highly efficient SERS activity

NASA Astrophysics Data System (ADS)

Song, Yahui; Miao, Tingting; Zhang, Peina; Bi, Cuixia; Xia, Haibing; Wang, Dayang; Tao, Xutang

2015-04-01

We investigate the effect of gold (Au) seeds prepared in cetyltrimethylammonium chloride solution (CTAC-Au seeds) on the index facets of trisoctahedral gold nanocrystals (TOH Au NCs). We demonstrate that monodisperse {331}-faceted TOH Au NCs with controllable sizes (from 60 to 255 nm) can be successfully prepared in high yield by using 3.0 nm CTAC-Au seeds or as-prepared 70 nm TOH Au NCs as seeds. We find that the electrocatalytic performance on methanol oxidation and surface enhancement Raman spectroscopy (SERS) activity of {331}-faceted TOH Au NCs is size-dependent. In comparison with well-known nanoporous gold (0.088 mA cm-2), {331}-faceted TOH Au NCs with sizes of 110 nm exhibit fairly high catalytic activity (0.178 mA cm-2) on methanol oxidation (1.0 M) in alkaline media due to the presence of increasing density of atomic steps, ledges, and kinks on the NC surfaces. Their current density is reduced by less than 7% after 500 cycling tests. {331}-Faceted TOH Au NCs with sizes of 175 nm exhibit the highest SERS activity for 4-aminothiophenol (4-ATP) molecules. The enhancement factors of a1 modes of 4-ATP molecules can reach the order of 109 when the 4-ATP concentration is 3 × 10-6 M. Moreover, Raman signals (ag modes) of 4,4'-dimercaptoazobenzene (DMAB) molecules on TOH Au NCs are stronger than those on spherical Au NCs of comparable size due to the enhanced laser-induced transformation of 4-ATP molecules by high-index {331}-facets during SERS measurement. Furthermore, the SERS intensities of 4-methylbenzenethiol (4-MTP) molecules on TOH Au NCs are also higher than those on spherical Au NCs of comparable size due to sharp extremities.We investigate the effect of gold (Au) seeds prepared in cetyltrimethylammonium chloride solution (CTAC-Au seeds) on the index facets of trisoctahedral gold nanocrystals (TOH Au NCs). We demonstrate that monodisperse {331}-faceted TOH Au NCs with controllable sizes (from 60 to 255 nm) can be successfully prepared in high yield by using 3.0 nm CTAC-Au seeds or as-prepared 70 nm TOH Au NCs as seeds. We find that the electrocatalytic performance on methanol oxidation and surface enhancement Raman spectroscopy (SERS) activity of {331}-faceted TOH Au NCs is size-dependent. In comparison with well-known nanoporous gold (0.088 mA cm-2), {331}-faceted TOH Au NCs with sizes of 110 nm exhibit fairly high catalytic activity (0.178 mA cm-2) on methanol oxidation (1.0 M) in alkaline media due to the presence of increasing density of atomic steps, ledges, and kinks on the NC surfaces. Their current density is reduced by less than 7% after 500 cycling tests. {331}-Faceted TOH Au NCs with sizes of 175 nm exhibit the highest SERS activity for 4-aminothiophenol (4-ATP) molecules. The enhancement factors of a1 modes of 4-ATP molecules can reach the order of 109 when the 4-ATP concentration is 3 × 10-6 M. Moreover, Raman signals (ag modes) of 4,4'-dimercaptoazobenzene (DMAB) molecules on TOH Au NCs are stronger than those on spherical Au NCs of comparable size due to the enhanced laser-induced transformation of 4-ATP molecules by high-index {331}-facets during SERS measurement. Furthermore, the SERS intensities of 4-methylbenzenethiol (4-MTP) molecules on TOH Au NCs are also higher than those on spherical Au NCs of comparable size due to sharp extremities. Electronic supplementary information (ESI) available: Extra TEM images and extinction spectra of the corresponding TOH Au NCs obtained with CTAB-Au seeds and CTAC-Au seeds, cyclic voltammograms of the corresponding TOH Au NCs with {221} facets and {331} facets in 0.50 M H2SO4 medium, cyclic voltammograms of TOH Au NCs with different sizes in 0.50 M H2SO4 medium and in 0.50 M KOH medium, the variation of oxidation peak current density of the GCEs modified by the 110 nm TOH Au NCs at different scanning cycle numbers, experimental extinction spectra of TOH Au NCs of different sizes, SERS spectra of 4-ATP molecules on the aggregates of 175 nm TOH Au NCs and 170 nm spherical Au NCs, the normal Raman spectrum of the neat film of the 4-ATP molecule, and summarized data of the Raman intensity and SERS enhancement factors of the TOH Au NCs with different sizes in specific Raman bands. See DOI: 10.1039/c5nr01049g

78 FR 18798 - Amendment of Class E Airspace; West Union, IA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-28

...-1434; Airspace Docket No. 11-ACE-27] Amendment of Class E Airspace; West Union, IA AGENCY: Federal... West Union, IA. Decommissioning of the West Union non-directional beacon (NDB) at George L. Scott... Federal Register a notice of proposed rulemaking (NPRM) to amend Class E airspace for the West Union, IA...

77 FR 71361 - Proposed Amendment of Class E Airspace; West Union, IA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-30

...-1434; Airspace Docket No. 11-ACE-27] Proposed Amendment of Class E Airspace; West Union, IA AGENCY... action proposes to amend Class E airspace at West Union, IA. Decommissioning of the West Union non... instrument approach procedures at George L. Scott Municipal Airport, West Union, IA. Airspace reconfiguration...

12 CFR Appendix A to Part 701 - Federal Credit Union Bylaws

Code of Federal Regulations, 2011 CFR

2011-01-01

... union must explain the reasons for the denial in writing. Section 3. Maintenance of membership share... member who is disruptive to credit union operations may be subject to limitations on services and access to credit union facilities. A credit union that wishes to restrict services to members no longer...

Leading the Local: Teachers Union Presidents Chart Their Own Course

ERIC Educational Resources Information Center

Johnson, Susan Moore; Donaldson, Morgaen L.; Munger, Mindy Sick; Papay, John P.; Qazilbash, Emily K.

2009-01-01

Teachers unions are among the most powerful, yet least studied, actors in public education today. Although public attention focuses on the influence of national unions, the policies that most affect teachers and schooling are bargained by local unions and school boards. Interviews with 30 recently elected local union presidents reveal that these…

12 CFR 721.2 - What is an incidental powers activity?

Code of Federal Regulations, 2010 CFR

2010-01-01

... business of credit unions; and (c) Involves risks similar in nature to those already assumed as part of the... Section 721.2 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS... in carrying out the mission or business of credit unions consistent with the Federal Credit Union Act...

12 CFR 741.7 - Conversion to a state-chartered credit union.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Conversion to a state-chartered credit union. 741.7 Section 741.7 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING... § 741.7 Conversion to a state-chartered credit union. Any federal credit union that petitions to convert...

12 CFR 741.7 - Conversion to a state-chartered credit union.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Conversion to a state-chartered credit union. 741.7 Section 741.7 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING... § 741.7 Conversion to a state-chartered credit union. Any federal credit union that petitions to convert...

12 CFR 704.3 - Corporate credit union capital.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 7 2012-01-01 2012-01-01 false Corporate credit union capital. 704.3 Section... CORPORATE CREDIT UNIONS § 704.3 Corporate credit union capital. (a) Capital requirements. (1) A corporate... percent or greater. (2) To ensure it meets its capital requirements, a corporate credit union must develop...

12 CFR 704.3 - Corporate credit union capital.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 7 2014-01-01 2014-01-01 false Corporate credit union capital. 704.3 Section... CORPORATE CREDIT UNIONS § 704.3 Corporate credit union capital. (a) Capital requirements. (1) A corporate... percent or greater. (2) To ensure it meets its capital requirements, a corporate credit union must develop...

12 CFR 704.3 - Corporate credit union capital.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 7 2013-01-01 2013-01-01 false Corporate credit union capital. 704.3 Section... CORPORATE CREDIT UNIONS § 704.3 Corporate credit union capital. (a) Capital requirements. (1) A corporate... percent or greater. (2) To ensure it meets its capital requirements, a corporate credit union must develop...

Open-Source Unionism: New Workers, New Strategies

ERIC Educational Resources Information Center

Schmid, Julie M.

2004-01-01

In "Open-Source Unionism: Beyond Exclusive Collective Bargaining," published in fall 2002 in the journal Working USA, labor scholars Richard B. Freeman and Joel Rogers use the term "open-source unionism" to describe a form of unionization that uses Web technology to organize in hard-to-unionize workplaces. Rather than depend on the traditional…

Crystal structure of Au25(SePh)18 nanoclusters and insights into their electronic, optical and catalytic properties

NASA Astrophysics Data System (ADS)

Song, Yongbo; Zhong, Juan; Yang, Sha; Wang, Shuxin; Cao, Tiantian; Zhang, Jun; Li, Peng; Hu, Daqiao; Pei, Yong; Zhu, Manzhou

2014-10-01

The crystal structure of selenolate-capped Au25(SePh)18- nanoclusters has been unambiguously determined for the first time, and provides a solid basis for a deeper understanding of the structure-property relationships. The selenolate-capped Au25 cluster shows noticeable differences from the previously reported Au25(SCH2CH2Ph)18- counterpart, albeit both share the icosahedral Au13 core and semi-ring Au2(SeR)3 or Au2(SR)3 motifs. Distinct differences in the electronic structure and optical, catalytic and electrochemical properties are revealed by the coupling experiments with density functional theory (TD-DFT) calculations. Overall, the successful determination of the Au25(SePh)18- structure removes any ambiguity about its structure, and comparison with the thiolated Au25 counterpart helps us to further understand how the ligands affect the properties of the nanocluster.The crystal structure of selenolate-capped Au25(SePh)18- nanoclusters has been unambiguously determined for the first time, and provides a solid basis for a deeper understanding of the structure-property relationships. The selenolate-capped Au25 cluster shows noticeable differences from the previously reported Au25(SCH2CH2Ph)18- counterpart, albeit both share the icosahedral Au13 core and semi-ring Au2(SeR)3 or Au2(SR)3 motifs. Distinct differences in the electronic structure and optical, catalytic and electrochemical properties are revealed by the coupling experiments with density functional theory (TD-DFT) calculations. Overall, the successful determination of the Au25(SePh)18- structure removes any ambiguity about its structure, and comparison with the thiolated Au25 counterpart helps us to further understand how the ligands affect the properties of the nanocluster. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr04631e

Vapochromic Behaviour of M[Au(CN)2]2-Based Coordination Polymers (M = Co, Ni)

PubMed Central

Lefebvre, Julie; Korčok, Jasmine L.; Katz, Michael J.; Leznoff, Daniel B.

2012-01-01

A series of M[Au(CN)2]2(analyte)x coordination polymers (M = Co, Ni; analyte = dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), pyridine; x = 2 or 4) was prepared and characterized. Addition of analyte vapours to solid M(μ-OH2)[Au(CN)2]2 yielded visible vapochromic responses for M = Co but not M = Ni; the IR νCN spectral region changed in every case. A single crystal structure of Zn[Au(CN)2]2(DMSO)2 revealed a corrugated 2-D layer structure with cis-DMSO units. Reacting a Ni(II) salt and K[Au(CN)2] in DMSO yielded the isostructural Ni[Au(CN)2]2(DMSO)2 product. Co[Au(CN)2]2(DMSO)2 and M[Au(CN)2]2(DMF)2 (M = Co, Ni) complexes have flat 2-D square-grid layer structures with trans-bound DMSO or DMF units; they are formed via vapour absorption by solid M(μ-OH2)[Au(CN)2]2 and from DMSO or DMF solution synthesis. Co[Au(CN)2]2(pyridine)4 is generated via vapour absorption by Co(μ-OH2)[Au(CN)2]2; the analogous Ni complex is synthesized by immersion of Ni(μ-OH2)[Au(CN)2]2 in 4% aqueous pyridine. Similar immersion of Co(μ-OH2)[Au(CN)2]2 yielded Co[Au(CN)2]2(pyridine)2, which has a flat 2-D square-grid structure with trans-pyridine units. Absorption of pyridine vapour by solid Ni(μ-OH2)[Au(CN)2]2 was incomplete, generating a mixture of pyridine-bound complexes. Analyte-free Co[Au(CN)2]2 was prepared by dehydration of Co(μ-OH2)[Au(CN)2]2 at 145 °C; it has a 3-D diamondoid-type structure and absorbs DMSO, DMF and pyridine to give the same materials as by vapour absorption from the hydrate. PMID:22737031

Synthesis of octahedral gold tip-blobbed nanoparticles and their dielectric sensing properties.

PubMed

Zhang, Liqiu; Jang, Hee-Jeong; Yoo, Sung Jae; Cho, Sanghyun; Won, Ji Hye; Liu, Lichun; Park, Sungho

2018-06-22

Site-selective synthesis of nanostructures is an important topic in the nanoscience community. Normally, the difference between seeds and deposition atoms in terms of crystallinity triggers the deposition atoms to grow initially at the specific site of nucleation. It is more challenging to control the deposition site of atoms that have the same composition as the seeds because the atoms tend to grow epitaxially, covering the whole surface of the seed nanoparticles. Gold (Au) nano-octahedrons used as seeds in this study possess obvious hierarchical surface energies depending on whether they are at vertices, edges, or terraces. Although vertices of Au nano-octahedrons have the highest surface energy, it remains a challenge to selectively deposit Au atoms at the vertices but not at the edges and faces; this selectivity is required to meet the ever-increasing demands of engineered nanomaterial properties. This work demonstrates an easy and robust method to precisely deposit Au nanoparticles at the vertices of Au nano-octahedrons via wet-chemical seed-mediated growth. The successful synthesis of octahedral Au tip-blobbed nanoparticles (Oh Au TBPs) benefited from the cooperative use of thin silver (Ag) layers at the surface of Au nano-octahedron seeds and iodide ions in the Au growth solution. As-synthesized Au nanostructures gave rise to hybrid optical properties, as evidenced from the UV-VIS-NIR extinction spectra, in which a new extinction peak appeared after Au nanoparticles were formed at the vertices of Au nano-octahedrons. A sensitivity evaluation toward dielectric media of a mixture of dimethyl sulfoxide and water suggested that Au TBPs were more optically sensitive compared to the original Au nano-octahedrons. The method demonstrated in this work is promising in the synthesis of advanced Au nanostructures with hybrid optical properties for versatile applications by engineering the surface energy of vertex-bearing Au nanostructures to trigger site-selective overgrowth of congener Au atoms. © 2018 IOP Publishing Ltd.

The neodymium-gold phase diagram

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saccone, A.; Maccio, D.; Delfino, S.

The Nd-Au phase diagram was studied in the 0 to 100 at. pct Au composition range by differential thermal analysis (DTA), X-ray diffraction (XRD), optical microscopy (LOM), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). Six intermetallic phases were identified, the crystallographic structures were determined or confirmed, and the melting behavior was determined, as follows: Nd{sub 2}Au, orthorhombic oP12-Co{sub 2}Si type, peritectic decomposition at 810 C; NdAu, R.T. form, orthorhombic oP8-FeB type, H.T. forms, orthorhombic oC8-CrB type and, at a higher temperature, cubic cP2-CsCl type, melting point 1470 C; Nd{sub 3}Au{sub 4}, trigonal hR42-Pu{sub 3}Pd{sub 4} type, peritectic decompositionmore » at 1250 C; Nd{sub 17}Au{sub 36}, tetragonal tP106-Nd{sub 17}Au{sub 36} type, melting point 1170 C; Nd{sub 14}Au{sub 51}, hexagonal hP65-Gd{sub 14}Ag{sub 51} type, melting point 1210 C; and NdAu{sub 6}, monoclinic mC28-PrAu{sub 6} type, peritectic decomposition at 875 C. Four eutectic reactions were found, respectively, at 19.0 at. pct Au and 655 C, at 63.0 at. pct Au and 1080 C, at 72.0 at. pct Au and 1050 C, and, finally, at 91.0 at. pct Au and 795 C. A catatectic decomposition of the ({beta}Nd) phase, at 825 C and {approx}1 at. pct Au, was also found. The results are briefly discussed and compared to those for the other rare earth-gold (R-Au) systems. A short discussion of the general alloying behavior of the coinage metals (Cu, Ag, and Au) with the rare-earth metals is finally presented.« less

The anticancer properties of iron core–gold shell nanoparticles in colorectal cancer cells

PubMed Central

Wu, Ya-Na; Wu, Ping-Ching; Yang, Li-Xing; Ratinac, Kyle R; Thordarson, Pall; Jahn, Kristina A; Chen, Dong-Hwang; Shieh, Dar-Bin; Braet, Filip

2013-01-01

Previously, iron core–gold shell nanoparticles (Fe@Au) have been shown to possess cancer-preferential cytotoxicity in oral and colorectal cancer (CRC) cells. However, CRC cell lines are less sensitive to Fe@Au treatment when compared with oral cancer cell lines. In this research, Fe@Au are found to decrease the cell viability of CRC cell lines, including Caco-2, HT-29, and SW480, through growth inhibition rather than the induction of cell death. The cytotoxicity induced by Fe@Au in CRC cells uses different subcellular pathways to the mitochondria-mediated autophagy found in Fe@Au-treated oral cancer cells, OECM1. Interestingly, the Caco-2 cell line shows a similar response to OECM1 cells and is thus more sensitive to Fe@Au treatment than the other CRC cell lines studied. We have investigated the underlying cell resistance mechanisms of Fe@Au-treated CRC cells. The resistance of CRC cells to Fe@Au does not result from the total amount of Fe@Au internalized. Instead, the different amounts of Fe and Au internalized appear to determine the different response to treatment with Fe-only nanoparticles in Fe@Au-resistant CRC cells compared with the Fe@Au-sensitive OECM1 cells. The only moderately cytotoxic effect of Fe@Au nanoparticles on CRC cells, when compared to the highly sensitive OECM1 cells, appears to arise from the CRC cells’ relative insensitivity to Fe, as is demonstrated by our Fe-only treatments. This is a surprising outcome, given that Fe has thus far been considered to be the “active” component of Fe@Au nanoparticles. Instead, we have found that the Au coatings, previously considered only as a passivating coating to protect the Fe cores from oxidation, significantly enhance the cytotoxicity of Fe@Au in certain CRC cells. Therefore, we conclude that both the Fe and Au in these core–shell nanoparticles are essential for the anticancer properties observed in CRC cells. PMID:24039416

Exploring the Photoreduction of Au(III) Complexes in the Gas-Phase

NASA Astrophysics Data System (ADS)

Marcum, Jesse C.; Kaufman, Sydney H.; Weber, J. Mathias

2010-06-01

We have used photodissociation spectroscopy to probe the electronic structure and photoreduction of Au(III) in gas-phase complexes containing Cl- and OH-. The gas-phase electronic spectrum of [AuCl_4]- closely resembles the aqueous solution spectrum, showing a lack of strong solvatochromic shifts. Substitution of Cl- ligands with OH- results in a strong blue shift, in agreement with ligand-field theory. Upon excitation, [AuCl_4]- can dissociate by loss of either one or two neutral Cl atoms, resulting in the reduction of gold from Au(III) to Au(II) and Au(I) respectively. The hydroxide substituted complex, [AuCl_2(OH)_2]-, demonstrates similar behavior but the only observable fragment channel is the loss of two neutral OH ligands, leading only to Au(I).

Tunable random lasing behavior in plasmonic nanostructures

NASA Astrophysics Data System (ADS)

Yadav, Ashish; Zhong, Liubiao; Sun, Jun; Jiang, Lin; Cheng, Gary J.; Chi, Lifeng

2017-01-01

Random lasing is desired in plasmonics nanostructures through surface plasmon amplification. In this study, tunable random lasing behavior was observed in dye molecules attached with Au nanorods (NRs), Au nanoparticles (NPs) and Au@Ag nanorods (NRs) respectively. Our experimental investigations showed that all nanostructures i.e., Au@AgNRs, AuNRs & AuNPs have intensive tunable spectral effects. The random lasing has been observed at excitation wavelength 532 nm and varying pump powers. The best random lasing properties were noticed in Au@AgNRs structure, which exhibits broad absorption spectrum, sufficiently overlapping with that of dye Rhodamine B (RhB). Au@AgNRs significantly enhance the tunable spectral behavior through localized electromagnetic field and scattering. The random lasing in Au@AgNRs provides an efficient coherent feedback for random lasers.

Theoretical prediction of a new stable structure of Au28(SR)20 cluster

NASA Astrophysics Data System (ADS)

Sun, Xiangxiang; Wang, Pu; Xiong, Lin; Pei, Yong

2018-07-01

A new stable structure of Au28(SR)20 cluster is predicted, which has the same gold core as two known structures but different Au-S framework. The new Au28(SR)20 cluster is proposed to be a key link in the evolution of Au22(SR)18, Au34(SR)22 and Au40(SR)24 clusters. The four clusters belong to a homogenous Au16+6N(SR)16+2N series (N = 1-4). The relative stabilities of the new Au28 isomer structure were confirmed by density functional theory calculations including dispersion corrections (DFT-D). It is found that upon protection of certain SR ligands, the new isomer structure has lower or comparable energies to two known cluster structures.

Sur la présence d'une série molassique (de type série pourprée) au Sud-Est de l'Ahaggar (In Guezzam, Ahaggar, Algérie)Presence of molassic series ('Série pourprée' type) in the Southeast of the Ahaggar (In Guezzam, Ahaggar, Algeria)

NASA Astrophysics Data System (ADS)

Djellit, Hamou; Henry, Bernard; Derder, Mohamed E. M.

In the western Ahaggar shield, the transition between the Precambrian and the Ordovician units is characterised by thick volcano-sedimentary series ('Série pourprée' of the Ahnet). This series, in part of Cambrian age, results from the demolition of the Panafrican belt. Similar series were known in grabens located between the West African craton and the Ahaggar, from the 'Adrar des Iforas', in the south, to the Ougarta belt, in the north. We describe in this study a new formation identical to the 'Série pourprée' of the Ahnet, but cropping out in the far Southeast of the Ahaggar (In Guezzam). This new datum improves the Panafrican belt configuration. To cite this article: H. Djellit et al., C. R. Geoscience 334 (2002) 789-794.

Successful synthesis and thermal stability of immiscible metal Au-Rh, Au-Ir andAu-Ir-Rh nanoalloys

NASA Astrophysics Data System (ADS)

Shubin, Yury; Plyusnin, Pavel; Sharafutdinov, Marat; Makotchenko, Evgenia; Korenev, Sergey

2017-05-01

We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn2][Ir(NO2)6], [AuEn2][Ir(NO2)6] х [Rh(NO2)6]1-х and [AuEn2][Rh(NO2)6]. The precursors employed contain all desired metals ‘mixed’ at the atomic level, thus providing significant advantages for obtaining alloys. The observations using high-resolution transmission electron microscopy show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5 ± 3 nm. Еnergy dispersive x-ray spectroscopy and x-ray powder diffraction (XRD) measurements confirm the formation of AuIr, AuRh, AuIr0.75Rh0.25, AuIr0.50Rh0.50 and AuIr0.25Rh0.75 metastable solid solutions. In situ high-temperature synchrotron XRD (HTXRD) was used to study the formation mechanism of nanoalloys. The observed transformations are described by the ‘conversion chemistry’ mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 °C for 30 h does not cause any dealloying process.

Successful synthesis and thermal stability of immiscible metal Au-Rh, Au-Ir andAu-Ir-Rh nanoalloys.

PubMed

Shubin, Yury; Plyusnin, Pavel; Sharafutdinov, Marat; Makotchenko, Evgenia; Korenev, Sergey

2017-05-19

We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn 2 ][Ir(NO 2 ) 6 ], [AuEn 2 ][Ir(NO 2 ) 6 ] х [Rh(NO 2 ) 6 ] 1-х and [AuEn 2 ][Rh(NO 2 ) 6 ]. The precursors employed contain all desired metals 'mixed' at the atomic level, thus providing significant advantages for obtaining alloys. The observations using high-resolution transmission electron microscopy show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5 ± 3 nm. Еnergy dispersive x-ray spectroscopy and x-ray powder diffraction (XRD) measurements confirm the formation of AuIr, AuRh, AuIr 0.75 Rh 0.25 , AuIr 0.50 Rh 0.50 and AuIr 0.25 Rh 0.75 metastable solid solutions. In situ high-temperature synchrotron XRD (HTXRD) was used to study the formation mechanism of nanoalloys. The observed transformations are described by the 'conversion chemistry' mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 °C for 30 h does not cause any dealloying process.

Nucleon-gold collisions at 200 A GeV using tagged d + Au interactions in the PHOBOS detector

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.; Zhang, J.; Phobos Collaboration

2015-09-01

Forward calorimetry in the PHOBOS detector has been used to study charged hadron production in d +Au , p +Au , and n +Au collisions at √{sN N}=200 GeV . The forward proton calorimeter detectors are described and a procedure for determining collision centrality with these detectors is detailed. The deposition of energy by deuteron spectator nucleons in the forward calorimeters is used to identify p +Au and n +Au collisions in the data. A weighted combination of the yield of p +Au and n +Au is constructed to build a reference for Au +Au collisions that better matches the isospin composition of the gold nucleus. The pT and centrality dependence of the yield of this improved reference system is found to match that of d +Au . The shape of the charged-particle transverse momentum distribution is observed to extrapolate smoothly from p +p ¯ to central d +Au as a function of the charged-particle pseudorapidity density. The asymmetry of positively and negatively charged hadron production in p +Au is compared to that of n +Au . No significant asymmetry is observed at midrapidity. These studies augment recent results from experiments at the CERN Large Hadron Collider and BNL Relativistic Heavy Ion Collider facilities to give a more complete description of particle production in p +A and d +A collisions, essential for the understanding the medium produced in high-energy nucleus-nucleus collisions.

Nucleon-gold collisions at 200A GeV using tagged d + Au interactions in the PHOBOS detector

DOE PAGES

Back, B. B.; Nouicer, R.; Baker, M. D.; ...

2015-09-23

Forward calorimetry in the PHOBOS detector has been used to study charged hadron production in d+Au, p+Au, and n+Au collisions at √s NN =200GeV. The forward proton calorimeter detectors are described and a procedure for determining collision centrality with these detectors is detailed. The deposition of energy by deuteron spectator nucleons in the forward calorimeters is used to identify p+Au and n+Au collisions in the data. A weighted combination of the yield of p+Au and n+Au is constructed to build a reference for Au+Au collisions that better matches the isospin composition of the gold nucleus. The p T and centralitymore » dependence of the yield of this improved reference system is found to match that of d+Au. The shape of the charged-particle transverse momentum distribution is observed to extrapolate smoothly from p+p¯ to central d+Au as a function of the charged-particle pseudorapidity density. The asymmetry of positively and negatively charged hadron production in p+Au is compared to that of n+Au. No significant asymmetry is observed at midrapidity. In conclusion, these studies augment recent results from experiments at the CERN Large Hadron Collider and BNL Relativistic Heavy Ion Collider facilities to give a more complete description of particle production in p+A and d+A collisions, essential for the understanding the medium produced in high-energy nucleus-nucleus collisions.« less

Selection and Socialization Effects in Early Adolescent Alcohol Use: A Propensity Score Analysis

PubMed Central

Scalco, Matthew D.; Trucco, Elisa M.; Coffman, Donna L.; Colder, Craig R.

2015-01-01

The robust correlation between peer and adolescent alcohol use (AU) has been taken as evidence for both socialization and selection processes in the etiology of adolescent AU. Accumulating evidence from studies using a diverse range of methodological and statistical approaches suggests that both processes are involved. A major challenge in testing whether peer AU predicts an adolescent's drinking (socialization) or whether an adolescent's drinking predicts peer AU (selection) is the myriad of potentially confounding factors that might lead to an overestimation of socialization and selection effects. After creating AU transition groups based on peer and adolescent AU across two waves (N = 765; age = 10-15; 53% female), we test whether transitions into AU by adolescents and peers predict later peer and adolescent AU respectively, using (1) propensity score analysis to balance transition groups on 26 potential confounds, (2) a longitudinal design with three waves to establish temporal precedence, and (3) both adolescent (target) and peer self-report of peer AU to disentangle effects attributable to shared reporter bias. Both selection and socialization were supported using both peer self-report of AU and adolescent-report of peer AU. Although cross-sectional analyses suggested peer self-reported models were associated with smaller effects than perceived peer AU, longitudinal analyses suggest a similar sized effect across reporter of peer AU for both selection and socialization. The implications of these findings for the etiology and treatment of adolescent AU are discussed. PMID:25601099

Application of Direct Current Atmospheric Pressure Glow Microdischarge Generated in Contact with a Flowing Liquid Solution for Synthesis of Au-Ag Core-Shell Nanoparticles.

PubMed

Dzimitrowicz, Anna; Jamroz, Piotr; Nyk, Marcin; Pohl, Pawel

2016-04-06

A direct current atmospheric pressure glow microdischarge (dc-μAPGD) generated between an Ar nozzle microjet and a flowing liquid was applied to produce Au-Ag core-shell nanoparticles (Au@AgCSNPs) in a continuous flow system. Firstly, operating dc-μAPGD with the flowing solution of the Au(III) ions as the cathode, the Au nanoparticles (AuNPs) core was produced. Next, to produce the core-shell nanostructures, the collected AuNPs solution was immediately mixed with an AgNO₃ solution and passed through the system with the reversed polarity to fabricate the Ag nanoshell on the AuNPs core. The formation of Au@AgCSNPs was confirmed using ultraviolet-visible (UV-Vis) absorbance spectrophotometry, transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Three localized surface plasmon resonance absorption bands with wavelengths centered at 372, 546, and 675 nm were observed in the UV-Vis spectrum of Au@AgCSNPs, confirming the reduction of both the Au(III) and Ag(I) ions. The right configuration of metals in Au@AgCSNPs was evidenced by TEM. The Au core diameter was 10.2 ± 2.0 nm, while the thickness of the Ag nanoshell was 5.8 ± 1.8 nm. The elemental composition of the bimetallic nanoparticles was also confirmed by EDS. It is possible to obtain 90 mL of a solution containing Au@AgCSNPs per hour using the applied microdischarge system.

Thiol ligand-induced transformation of Au38(SC2H4Ph)24 to Au36(SPh-t-Bu)24.

PubMed

Zeng, Chenjie; Liu, Chunyan; Pei, Yong; Jin, Rongchao

2013-07-23

We report a disproportionation mechanism identified in the transformation of rod-like biicosahedral Au38(SCH2CH2Ph)24 to tetrahedral Au36(TBBT)24 nanoclusters. Time-dependent mass spectrometry and optical spectroscopy analyses unambiguously map out the detailed size-conversion pathway. The ligand exchange of Au38(SCH2CH2Ph)24 with bulkier 4-tert-butylbenzenethiol (TBBT) until a certain extent starts to trigger structural distortion of the initial biicosahedral Au38(SCH2CH2Ph)24 structure, leading to the release of two Au atoms and eventually the Au36(TBBT)24 nanocluster with a tetrahedral structure, in which process the number of ligands is interestingly preserved. The other product of the disproportionation process, i.e., Au40(TBBT)m+2(SCH2CH2Ph)24-m, was concurrently observed as an intermediate, which was the result of addition of two Au atoms and two TBBT ligands to Au38(TBBT)m(SCH2CH2Ph)24-m. The reaction kinetics on the Au38(SCH2CH2Ph)24 to Au36(TBBT)24 conversion process was also performed, and the activation energies of the structural distortion and disproportionation steps were estimated to be 76 and 94 kJ/mol, respectively. The optical absorption features of Au36(TBBT)24 are interpreted on the basis of density functional theory simulations.

Uncommon and Emissive {[Au2(C3H6NS2)2][Au(C3H6NS2)2]2(PF6)2} Mixed Au+ and Au3+ Pseudotetranuclear Crystalline Compound: Synthesis, Structural Characterization, and Optical Properties.

PubMed

Langaro, Ana P; Souza, Ana K R; Morassuti, Claudio Y; Lima, Sandro M; Casagrande, Gleison A; Deflon, Victor M; Nunes, Luiz A O; Da Cunha Andrade, Luis H

2016-11-23

An uncommon emissive pseudotetranuclear compound, {[Au 2 (C 3 H 6 NS 2 ) 2 ][Au(C 3 H 6 NS 2 ) 2 ] 2 (PF 6 ) 2 }, was synthesized and characterized in terms of its structure and optical properties. The synthesis produced a crystalline compound composed of four gold atoms with two different oxidation states (Au + and Au 3+ ) in the same crystalline structure. The title complex belonged to a triclinic crystalline system involving the centrosymmetric P1̅ space group. X-ray diffractometry and vibrational spectroscopy (infrared, Raman, and SERS) were used for structural characterization of the new crystal. The vibrational spectroscopy techniques supported the X-ray diffraction results and confirmed the presence of bonds including Au-Au and Au-S. Optical characterization performed using UV-vis spectroscopy showed that under ultraviolet excitation, the emissive crystalline complex presented characteristic broad luminescent bands centered at 420 and 670 nm.

Enhancement of simultaneous gold and copper recovery from discarded mobile phone PCBs using Bacillus megaterium: RSM based optimization of effective factors and evaluation of their interactions.

PubMed

Arshadi, M; Mousavi, S M; Rasoulnia, P

2016-11-01

Bioleaching of Au from mobile phone printed circuit boards (MPPCBs) was studied, using Bacillus megaterium which is a cyanogenic bacterium. To maximize Au extraction, initial pH, pulp density, and glycine concentration were optimized via response surface methodology (RSM). Bioleaching of Cu, an important inhibitor on Au recovery, was also examined. To maximize Au recovery, the optimal condition suggested by the models was initial pH of 10, pulp density of 8.13g/l, and glycine concentration of 10g/l. Under the optimal condition, approximately 72% of Cu and 65g Au/ton MPPCBs, which is 7 times greater than the recovery from gold mines, was extracted. Cu elimination from the MPPCBs having a rich content of Au did not cause a significant effect on Au recovery. It was found that when the ratio of Cu to Au is high, Cu elimination can considerably improve Au recovery. B. megaterium could extract the total Au from PCBs containing 130g Au/ton MPPCBs. Copyright © 2016 Elsevier Ltd. All rights reserved.

CO2 hydrogenation to methanol on supported Au catalysts under moderate reaction conditions: support and particle size effects.

PubMed

Hartadi, Yeusy; Widmann, Daniel; Behm, R Jürgen

2015-02-01

The potential of metal oxide supported Au catalysts for the formation of methanol from CO2 and H2 under conditions favorable for decentralized and local conversion, which could be concepts for chemical energy storage, was investigated. Significant differences in the catalytic activity and selectivity of Au/Al2 O3 , Au/TiO2 , AuZnO, and Au/ZrO2 catalysts for methanol formation under moderate reaction conditions at a pressure of 5 bar and temperatures between 220 and 240 °C demonstrate pronounced support effects. A high selectivity (>50 %) for methanol formation was obtained only for Au/ZnO. Furthermore, measurements on Au/ZnO samples with different Au particle sizes reveal distinct Au particle size effects: although the activity increases strongly with the decreasing particle size, the selectivity decreases. The consequences of these findings for the reaction mechanism and for the potential of Au/ZnO catalysts for chemical energy storage and a "green" methanol technology are discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Predictors of Time to Union After Operative Fixation of Closed Ankle Fractures.

PubMed

Matson, Andrew P; Hamid, Kamran S; Adams, Samuel B

2017-08-01

Ankle fractures are common and represent a significant burden to society. We aim to report the rate of union as determined by clinical and radiographic data, and to identify factors that predict time to union. A cohort of 112 consecutive patients with isolated, closed, operative malleolar ankle fractures treated with open reduction and internal fixation was retrospectively reviewed for time to clinical union. Clinical union was defined based on radiographic and clinical parameters, and delayed union was defined by time to union >12 weeks. Injury characteristics, patient factors and treatment variables were recorded, and statistical techniques employed included the Chi-square test, the Student's T-test, and multivariate linear regression modeling. Forty-two (37.5%) of patients who achieved union did so in less than 12 weeks, and 69 (61.6%) of these patients demonstrated delayed union at a mean of 16.7 weeks (range, 12.1-26.7 weeks), and the remaining patient required revision surgery. Factors associated with higher rates of delayed union or increased time to union included tobacco use, bimalleolar fixation, and high energy mechanism (all p<0.05). In regression analysis, statistically significant negative predictors of time to union were BMI, dislocation of the tibiotalar joint, external fixation for initial stabilization and delay of definitive management (all p<0.05). Patient characteristics, injury factors and treatment variables are predictive of time to union following open reduction and internal fixation of closed ankle fractures. These findings should assist with patient counseling, and help guide the provider when considering adjunctive therapies that promote bone healing. Prognostic, Level IV: Case series.

Regional Utilization of the Union Catalog of Medical Periodicals System

PubMed Central

Sprinkle, Michael D.

1969-01-01

This paper describes regional utilization of the Union Catalog of Medical Periodicals system and data base in producing union lists outside Metropolitan New York, the area served by the Union Catalog. A basic introduction to the Medical Library Center of New York's UCMP system is set forth, demonstrating the system's value in the production of such medical and paramedical union lists throughout the country. Several applications are then described, showing how these union lists were produced. PMID:5789816

Amplified photoacoustic performance and enhanced photothermal stability of reduced graphene oxide coated gold nanorods for sensitive photoacoustic imaging.

PubMed

Moon, Hyungwon; Kumar, Dinesh; Kim, Haemin; Sim, Changbeom; Chang, Jin-Ho; Kim, Jung-Mu; Kim, Hyuncheol; Lim, Dong-Kwon

2015-03-24

We report a strongly amplified photoacoustic (PA) performance of the new functional hybrid material composed of reduced graphene oxide and gold nanorods. Due to the excellent NIR light absorption properties of the reduced graphene oxide coated gold nanorods (r-GO-AuNRs) and highly efficient heat transfer process through the reduced graphene oxide layer, r-GO-AuNRs exhibit excellent photothermal stability and significantly higher photoacoustic amplitudes than those of bare-AuNRs, nonreduced graphene oxide coated AuNRs (GO-AuNRs), or silica-coated AuNR, as demonstrated in both in vitro and in vivo systems. The linear response of PA amplitude from reduced state controlled GO on AuNR indicates the critical role of GO for a strong photothermal effect of r-GO-AuNRs. Theoretical studies with finite-element-method lab-based simulation reveal that a 4 times higher magnitude of the enhanced electromagnetic field around r-GO-AuNRs can be generated compared with bare AuNRs or GO-AuNRs. Furthermore, the r-GO-AuNRs are expected to be a promising deep-tissue imaging probe because of extraordinarily high PA amplitudes in the 4-11 MHz operating frequency of an ultrasound transducer. Therefore, the r-GO-AuNRs can be a useful imaging probe for highly sensitive photoacoustic images and NIR sensitive therapeutics based on a strong photothermal effect.

Analyzing the electrooxidation of ethylene glycol and glucose over platinum-modified gold electrocatalysts in alkaline electrolyte using in-situ infrared spectroscopy

NASA Astrophysics Data System (ADS)

Mahoney, Elizabeth G.; Sheng, Wenchao; Cheng, Mei; Lee, Kevin X.; Yan, Yushan; Chen, Jingguang G.

2016-02-01

Platinum modified gold (Pt/Au) catalysts are evaluated for the electrooxidation of ethylene glycol (EG) and glucose (Glc). The Pt/Au catalysts are synthesized on an Au disk and supported Au/C particles through the galvanic displacement of a copper monolayer with Pt. The Pt/Au catalysts are compared to monometallic Pt and Au catalysts for the oxidation of EG and Glc in alkaline electrolyte. The Pt/Au disk has an onset potential for these reactions that is similar to Pt and is lower than Au. The supported catalysts are less active toward the electrooxidation of EG and Glc than the corresponding disk electrodes, but the Pt/Au/C also has an onset potential similar to Pt/C. In-situ FTIR is used to analyze the C-C bond scission in both reactions on the surfaces of Pt, Au, and Pt/Au disks. While the Pt/Au disk is found to have a low onset potential for the oxidation of EG, it does not produce as much CO2 as bulk Pt. On the other hand, the FTIR results show that CO2 is produced for the oxidation of Glc on the Pt/Au disk. These results show promise for the possibility of decreasing the amount of Pt needed for the electrooxidation of polyol molecules.

How Do the Size, Charge and Shape of Nanoparticles Affect Amyloid β Aggregation on Brain Lipid Bilayer?

NASA Astrophysics Data System (ADS)

Kim, Yuna; Park, Ji-Hyun; Lee, Hyojin; Nam, Jwa-Min

2016-01-01

Here, we studied the effect of the size, shape, and surface charge of Au nanoparticles (AuNPs) on amyloid beta (Aβ) aggregation on a total brain lipid-based supported lipid bilayer (brain SLB), a fluid platform that facilitates Aβ-AuNP aggregation process. We found that larger AuNPs induce large and amorphous aggregates on the brain SLB, whereas smaller AuNPs induce protofibrillar Aβ structures. Positively charged AuNPs were more strongly attracted to Aβ than negatively charged AuNPs, and the stronger interactions between AuNPs and Aβ resulted in fewer β-sheets and more random coil structures. We also compared spherical AuNPs, gold nanorods (AuNRs), and gold nanocubes (AuNCs) to study the effect of nanoparticle shape on Aβ aggregation on the brain SLB. Aβ was preferentially bound to the long axis of AuNRs and fewer fibrils were formed whereas all the facets of AuNCs interacted with Aβ to produce the fibril networks. Finally, it was revealed that different nanostructures induce different cytotoxicity on neuroblastoma cells, and, overall, smaller Aβ aggregates induce higher cytotoxicity. The results offer insight into the roles of NPs and brain SLB in Aβ aggregation on the cell membrane and can facilitate the understanding of Aβ-nanostructure co-aggregation mechanism and tuning Aβ aggregate structures.

Cytotoxicity of Ultrasmall Gold Nanoparticles on Planktonic and Biofilm Encapsulated Gram-Positive Staphylococci.

PubMed

Boda, Sunil Kumar; Broda, Janine; Schiefer, Frank; Weber-Heynemann, Josefine; Hoss, Mareike; Simon, Ulrich; Basu, Bikramjit; Jahnen-Dechent, Willi

2015-07-01

The emergence of multidrug resistant bacteria, especially biofilm-associated Staphylococci, urgently requires novel antimicrobial agents. The antibacterial activity of ultrasmall gold nanoparticles (AuNPs) is tested against two gram positive: S. aureus and S. epidermidis and two gram negative: Escherichia coli and Pseudomonas aeruginosa strains. Ultrasmall AuNPs with core diameters of 0.8 and 1.4 nm and a triphenylphosphine-monosulfonate shell (Au0.8MS and Au1.4MS) both have minimum inhibitory concentration (MIC) and minimum bactericidal concentration of 25 × 10(-6) m [Au]. Disc agar diffusion test demonstrates greater bactericidal activity of the Au0.8MS nanoparticles over Au1.4MS. In contrast, thiol-stabilized AuNPs with a diameter of 1.9 nm (AuroVist) cause no significant toxicity in any of the bacterial strains. Ultrasmall AuNPs cause a near 5 log bacterial growth reduction in the first 5 h of exposure, and incomplete recovery after 21 h. Bacteria show marked membrane blebbing and lysis in biofilm-associated bacteria treated with ultrasmall AuNP. Importantly, a twofold MIC dosage of Au0.8MS and Au1.4MS each cause around 80%-90% reduction in the viability of Staphylococci enveloped in biofilms. Altogether, this study demonstrates potential therapeutic activity of ultrasmall AuNPs as an effective treatment option against staphylococcal infections. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of Sn and SnAgCu Solders Wetting Reaction on Ni/Pd/Au Substrates

NASA Astrophysics Data System (ADS)

Liu, C. Y.; Wei, Y. S.; Lin, E. J.; Hsu, Y. C.; Tang, Y. K.

2016-12-01

Wetting reactions of pure Sn and Sn-Ag-Cu solder balls on Au(100 Å and 1000 Å)/Pd(500 Å)/Ni substrates were investigated. The (Au, Pd)Sn4 phase formed in the initial interfacial reaction between pure Sn and Au(100 Å and 1000 Å)/Pd(500 Å)/Ni substrates. Then, the initially formed (Au, Pd)Sn4 compound layer either dissolved or spalled into the molten Sn solder with 3 s of reflowing. The exposed Ni under-layer reacted with Sn solder and formed an interfacial Ni3Sn4 compound. We did not observe spalling compound in the Sn-Ag-Cu case, either on the thin Au (100 Å) or the thick Au (1000 Å) substrates. This implies that the Cu content in the Sn-Ag-Cu solder can efficiently suppress the spalling effect and really stabilize the interfacial layer. Sn-Ag-Cu solder has a better wetting than that of the pure Sn solder, regardless of the Au thickness of the Au/Pd/Ni substrate. For both cases of pure Sn and Sn-Ag-Cu, the initial wetting (<3-s reflowing) on the thin Au (100 Å) substrate is better than that of the thick Au (1000 Å) substrate. Over 3-s reflowing, the wetting on the thicker Au layer (1000 Å) substrate becomes better than the wetting on the thinner Au layer (100 Å) substrate.

Structures and magnetic properties of Fe and Ni monoatomic chains encapsulated by an Au nanotube

NASA Astrophysics Data System (ADS)

Han, Zhi-Dong; Li, Xiu-Yan; Yang, Zhi; Liu, Rui-Ping; Liu, Shao-Ding; Zhang, Ying

2012-11-01

Structures and magnetic properties of transition metal (TM) Fe or Ni monoatomic chains (MACs) encapsulated by a Au (5, 5) nanotube (Fe@Au and Ni@Au) are investigated using the density functional theory (DFT). The calculated results show that both Fe@Au and Ni@Au prefer to adopt ferromagnetic (FM) orders as ground states. In particular, the Fe@Au keeps the magnetic properties of free-standing Fe MAC, indicating that this system may be viewed as a new candidate in electromagnetic devices.

26 CFR 1.501(c)(14)-1 - Credit unions and mutual insurance funds.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Credit unions and mutual insurance funds. 1.501(c... unions and mutual insurance funds. Credit unions (other than Federal credit unions described in section 501(c)(1)) without capital stock, organized and operated for mutual purposes and without profit, are...

26 CFR 1.501(c)(14)-1 - Credit unions and mutual insurance funds.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Credit unions and mutual insurance funds. 1.501(c... unions and mutual insurance funds. Credit unions (other than Federal credit unions described in section 501(c)(1)) without capital stock, organized and operated for mutual purposes and without profit, are...

12 CFR 721.6 - May a credit union derive income from activities approved under this part?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false May a credit union derive income from activities approved under this part? 721.6 Section 721.6 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS INCIDENTAL POWERS § 721.6 May a credit union derive income...

12 CFR 721.6 - May a credit union derive income from activities approved under this part?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 6 2011-01-01 2011-01-01 false May a credit union derive income from activities approved under this part? 721.6 Section 721.6 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS INCIDENTAL POWERS § 721.6 May a credit union derive income...

Career Transitions after a Long Experience as Trade Union Officer: A Qualitative Study

ERIC Educational Resources Information Center

Cohen-Scali, Valérie

2016-01-01

In France, trade union officers are former shop stewards who have chosen to work full-time for the union for several years. This research investigates the career transitions of former union officers who have returned to the labour market following extended experience with high-level responsibilities in the union. Semi-directed interviews were…

Teacher Unionism in Changing Times: Is This the Real "New Unionism"?

ERIC Educational Resources Information Center

Stevenson, Howard

2015-01-01

This article provides a case study of union change in an environment in which radical school restructuring is taking place, and active strategies to weaken and marginalize organized teachers are being pursued by the state. The case study union is the National Union of Teachers in England. The article explores a number of different strategies open…

New Roles for Teachers Unions? Reform Unionism in School Decentralization

ERIC Educational Resources Information Center

Donaldson, Morgaen L.; Mayer, Anysia P.; Cobb, Casey D.; LeChasseur, Kimberly; Welton, Anjale

2013-01-01

Of late, teachers unions have worked together with district management in new and notable ways. This paper examines the role of teachers unions in shaping the Together Initiative (TI), which seeks to increase autonomy and broaden decision making in urban schools in one northeastern state. In general, state-level union leaders have taken more…

Reachout: Associations of College Unions-International Proceedings of the Forty Eighth Annual Conference.

ERIC Educational Resources Information Center

Association of Coll. Unions-International, Madison, WI.

A wide range of articles concerned with the major work and interests of college unions are organized into six topical areas; (1) philosophical considerations about the purposes and directions of college unions; (2) management and operation of the college union; (3) food service; (4) programming; (5) contemporary society and the college union; and…

Inverse Catalysts for CO Oxidation: Enhanced Oxide–Metal Interactions in MgO/Au(111), CeO 2/Au(111), and TiO 2/Au(111)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palomino, Robert M.; Gutiérrez, Ramón A.; Liu, Zongyuan

Au(111) does not bind CO and O 2 well. The deposition of small nanoparticles of MgO, CeO 2, and TiO 2 on Au(111) produces excellent catalysts for CO oxidation at room temperature. In an inverse oxide/metal configuration there is a strong enhancement of the oxide–metal interactions, and the inverse catalysts are more active than conventional Au/MgO(001), Au/CeO 2(111), and Au/TiO 2(110) catalysts. An identical trend was seen after comparing the CO oxidation activity of TiO2/Au and Au/TiO 2 powder catalysts. In the model systems, the activity increased following the sequence: MgO/Au(111) < CeO 2/Au(111) < TiO 2/Au(111). Ambient pressure X-raymore » photoelectron spectroscopy (AP-XPS) was used to elucidate the role of the titania–gold interface in inverse TiO 2/Au(111) model catalysts during CO oxidation. Stable surface intermediates such as CO(ads), CO 3 2–(ads), and OH(ads) were identified under reaction conditions. CO 3 2–(ads) and OH(ads) behaved as spectators. The concentration of CO(ad) initially increased and then decreased with increasing TiO 2 coverage, demonstrating a clear role of the Ti–Au interface and the size of the TiO 2 nanostructures in the catalytic process. Overall, our results show an enhancement in the strength of the oxide–metal interactions when working with inverse oxide/metal configurations, a phenomenon that can be utilized for the design of efficient catalysts useful for green and sustainable chemistry.« less

Fabrication of Au 25(SG) 18–ZIF-8 Nanocomposites: A Facile Strategy to Position Au 25(SG) 18 Nanoclusters Inside and Outside ZIF-8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Yucheng; Fan, Shiyan; Yu, Wenqian

Multifunctional composite materials are currently highly desired for sustainable energy applications. A general strategy to integrate atomically precise Au 25(SG) 18 with ZIF-8 (Zn(MeIm) 2, MeIm = 2-methylimidazole), is developed in this paper via the typical Zn-carboxylate type of linkage. Au 25(SG) 18 are uniformly encapsulated into a ZIF-8 framework (Au 25(SG) 18@ZIF-8) by coordination-assisted self-assembly. In contrast, Au 25(SG) 18 integrated by simple impregnation is oriented along the outer surface of ZIF-8 (Au 25(SG) 18/ZIF-8). The porous structure and thermal stability of these nanocomposites are characterized by N 2 adsorption–desorption isothermal analysis and thermal gravimetric analysis. The distribution ofmore » Au 25(SG) 18 in the two nanocomposites is confirmed by electron microscopy, and the accessibility of Au 25(SG) 18 is evaluated by the 4-nitrophenol reduction reaction. The as-prepared nanocomposites retain the high porosity and thermal stability of the ZIF-8 matrix, while also exhibiting the desired catalytic and optical properties derived from the integrated Au 25(SG) 18 nanoclusters (NCs). Au 25(SG) 18@ZIF-8 with isolated Au 25 sites is a promising heterogenous catalyst with size selectivity imparted by the ZIF-8 matrix. Finally, the structural distinction between Au 25(SG) 18@ZIF-8 and Au 25(SG) 18/ZIF-8 determines their different emission features, and provides a new strategy to adjust the optical behavior of Au 25(SG) 18 for applications in bioimaging and biotherapy.« less

Fabrication of Au 25(SG) 18–ZIF-8 Nanocomposites: A Facile Strategy to Position Au 25(SG) 18 Nanoclusters Inside and Outside ZIF-8

DOE PAGES

Luo, Yucheng; Fan, Shiyan; Yu, Wenqian; ...

2017-12-22

Multifunctional composite materials are currently highly desired for sustainable energy applications. A general strategy to integrate atomically precise Au 25(SG) 18 with ZIF-8 (Zn(MeIm) 2, MeIm = 2-methylimidazole), is developed in this paper via the typical Zn-carboxylate type of linkage. Au 25(SG) 18 are uniformly encapsulated into a ZIF-8 framework (Au 25(SG) 18@ZIF-8) by coordination-assisted self-assembly. In contrast, Au 25(SG) 18 integrated by simple impregnation is oriented along the outer surface of ZIF-8 (Au 25(SG) 18/ZIF-8). The porous structure and thermal stability of these nanocomposites are characterized by N 2 adsorption–desorption isothermal analysis and thermal gravimetric analysis. The distribution ofmore » Au 25(SG) 18 in the two nanocomposites is confirmed by electron microscopy, and the accessibility of Au 25(SG) 18 is evaluated by the 4-nitrophenol reduction reaction. The as-prepared nanocomposites retain the high porosity and thermal stability of the ZIF-8 matrix, while also exhibiting the desired catalytic and optical properties derived from the integrated Au 25(SG) 18 nanoclusters (NCs). Au 25(SG) 18@ZIF-8 with isolated Au 25 sites is a promising heterogenous catalyst with size selectivity imparted by the ZIF-8 matrix. Finally, the structural distinction between Au 25(SG) 18@ZIF-8 and Au 25(SG) 18/ZIF-8 determines their different emission features, and provides a new strategy to adjust the optical behavior of Au 25(SG) 18 for applications in bioimaging and biotherapy.« less

Fabrication of Au25 (SG)18 -ZIF-8 Nanocomposites: A Facile Strategy to Position Au25 (SG)18 Nanoclusters Inside and Outside ZIF-8.

PubMed

Luo, Yucheng; Fan, Shiyan; Yu, Wenqian; Wu, Zili; Cullen, David A; Liang, Chaolun; Shi, Jianying; Su, Chengyong

2018-02-01

Multifunctional composite materials are currently highly desired for sustainable energy applications. A general strategy to integrate atomically precise Au 25 (SG) 18 with ZIF-8 (Zn(MeIm) 2 , MeIm = 2-methylimidazole), is developed via the typical Zn-carboxylate type of linkage. Au 25 (SG) 18 are uniformly encapsulated into a ZIF-8 framework (Au 25 (SG) 18 @ZIF-8) by coordination-assisted self-assembly. In contrast, Au 25 (SG) 18 integrated by simple impregnation is oriented along the outer surface of ZIF-8 (Au 25 (SG) 18 /ZIF-8). The porous structure and thermal stability of these nanocomposites are characterized by N 2 adsorption-desorption isothermal analysis and thermal gravimetric analysis. The distribution of Au 25 (SG) 18 in the two nanocomposites is confirmed by electron microscopy, and the accessibility of Au 25 (SG) 18 is evaluated by the 4-nitrophenol reduction reaction. The as-prepared nanocomposites retain the high porosity and thermal stability of the ZIF-8 matrix, while also exhibiting the desired catalytic and optical properties derived from the integrated Au 25 (SG) 18 nanoclusters (NCs). Au 25 (SG) 18 @ZIF-8 with isolated Au 25 sites is a promising heterogenous catalyst with size selectivity imparted by the ZIF-8 matrix. The structural distinction between Au 25 (SG) 18 @ZIF-8 and Au 25 (SG) 18 /ZIF-8 determines their different emission features, and provides a new strategy to adjust the optical behavior of Au 25 (SG) 18 for applications in bioimaging and biotherapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.