294 research outputs found
Unsuccessful Cassava Brown Streak Disease (CBSD) evaluation attempts in western Democratic Republic of Congo and implications with cassava root necrosis disease (CRND) etiology
Open Access ArticleCassava brown streak disease (CBSD) is the second most important virus disease after Cassava mosaic disease (CMD), infecting cassava (ManihotesculetaCrantz) in Africa. The disease is caused by two distinct viruses, Cassava brown streak virus [2, 3] and Ugandan Cassava brown streak virus (family, Potyviridae: genus, Ipomovirus). Transmission of CBSV from one plant to another is reported to occur through grafting CBSV-free with infected cuttings and subsequent dissemination by infected cuttings. The basic approach to control of CBSD is selecting planting material from symptomless mother plants. Graft inoculation is the most efficient and effective of the techniques for CBSD virus transmission and consequently cuttings are the most effective way of the disease spreading.
In early 2000s, cassava root necrosis similar to those of CBSD were reported in western provinces of Democratic Republic of Congo (RDC) (Kinshasa and Kongo Central) and up to date PCR diagnoses did not detect any causal agent related to the observed symptoms and the disease which was still referred as âCBSD-like diseaseâ.
Due to lack of molecular data and the similarity of root symptoms with CBSD, the existence of a virus has always been suspected to be the cause of CBSD-like propagation. Thus, 2 field experiments were proposed in order to verify the existence of a systematic transmission of a possible CBSD related virus, knowing that CBSD viruses are transmitted efficiently by cuttings.
The first trial focused on the field evaluation of CBSD â like infected and apparently uninfected planting materials, while the second trial involved the importation of tanzanian CBSD resistant genotypes for evaluation in INERA Mvuazi research center under CBSD-like infection conditions.
Results of the first trial did not show a systemic transmission of any CBSD-like pathogen while CBSD-resistant parents involved in the second trial all succumbed to CBSD-like disease
Analisis Perilaku Berisiko Tertular Human Immunodeficiency Virus / Acquired Immuno Deficiency Syndrome (Hiv/aids) pada Terpidana Kasus Narkoba di Lapas Kelas Iia Kota Kendari Tahun 2016
HIV/AIDS merupakan masalah kesehatan yang mendunia. Infeksi dari virus yang menyerang kekebalan tubuhmanusia ini dihadapi oleh negara maju dan berkembang. Penyalahgunaan narkoba dapat mempengaruhiperilaku berisiko HIV/AIDS, khususnya melalui pemakaian bersama jarum suntik narkoba. Tujuan penelitian iniadalah untuk mengetahui perilaku berisiko tertular HIV/AIDS pada terpidana kasus narkoba di LAPAS Kelas IIAKendari tahun 2016. Jenis penelitian ini adalah penelitian kuantitatif dengan menggunakan desain penelitiansurvey deskriptif. Populasi dalam penelitian ini adalah seluruh terpidana kasus narkoba yang dipenjara diLAPAS Kelas IIA Kendari yaitu sebanyak 135 orang dan sampel pada penelitian ini sebanyak 56 orang. Teknikpengambilan sampel dalam penelitian ini menggunakan metode Simple Random Sampling. Hasil penelitianmenunjukkan bahwa pengetahuan responden tentang HIV/AIDS sudah cukup baik yaitu sebesar 98%. Sikapresponden terhadap HIV/AIDS cenderung menunjukkan sikap postitif yaitu sebanyak 95%. Tindakan respondenyang berisiko tertular HIV/AIDS sebelum berada di LAPAS sebanyak 93%. Selain itu, responden yangmengetahui dan mendapat risiko tertular HIV/AIDS dari teman sesama napinya sebanyak 29%. Disarankanuntuk pihak Lembaga Pemasyarakatan Kelas IIA Kendari agar para petugas LAPAS ditingkatkan pengawasannyaterhadap narapidana
Tingkat Bahaya Erosi (TBE) pada Hutan dan Lahan Kakao di Desa Sejahtera, Kecamatan Palolo, Kabupaten Sigi
Pada umumnya erosi merupakan faktor utama yang menyebabkan kerusakan tanah. Terjadinya erosi dipengaruhi oleh beberapa faktor antara lain erosivitas, erodibilitas, kemiringan dan panjang lereng, pengelolaan tanaman dan pengelolaan tanah. Penelitian ini dilaksanakan pada bulan Juni sampai dengan bulan Oktober 2012 dengan menggunakan metode survey secara langsung dilapangan dan dilanjutkan dengan pengambilan sampel bahan untuk analisis di Laboratorium. Kemudian hasil analisis tersebut diolah dengan menggunakan persamaan USLE (Universal Soil Loss Equation). Hasil analisis dari penelitian ini yaitu batas toleransi pada hutan 1 dan hutan 2 adalah 29,80 dan 30,60 ton/ha/thn, sedangkan lahan kakao berkisar antara 24,55-34,10 ton/ha/thn. Pada penelitian ini tingkat bahaya erosi hutan 1 dan hutan 2 tergolong rendah (R) yaitu 0,09 dan 0,08. Sedangkan tingkat bahaya erosi pada lahan kakao tertinggi terdapat pada lahan kakao 2c yaitu 18,68 dan tingkat bahaya erosi pada lahan kakao terendah terdapat pada lahan kakao 1b yaitu 3,70
First report and preliminary evaluation of cassava root necrosis in Angola
Open Access ArticleCassava is a main staple food for 800 million people world-wide. Production is limited by pest and pathogens. The most devastating cassava viruses are Cassava Brown Streak Virus and Uganda Cassava Brown Streak Virusboth causing severe root necrosis called Cassava Brown Streak Disease. In the last 10 years, the Cassava Brown Streak Disease (CBSD)has spread across Africa from the east coast of Africa to central Africa. Similar root necrosis to cassava brown streak disease has also been identified in the Democratic Republic of Congo where the first symptoms were identified in 2002 in Kinshasa and Kongo central province. In 2012, the presence of CBSD was confirmed in eastern Democratic Republic of Congo. All attempts since 2002 in western Democratic Republic of Congo to identify the cause of these root necrosis have failed. In 2017, a team of scientists surveying the Songololo Territory in the Kongo central province at the northern Angola, identified the same root necrosis similar to CBSD in several localities bordering Angola. These unexpected results will foreshadow the presence of cassava root necrosis in Angola. This preliminary investigation in northern Angola was conducted specifically in the Zaire province and the territory of Mbanza Kongo at approximatively 62 kms from the Democratic Republic of Congo border in order to verify, whether or not, these root necrosis are present in Angola. Results obtained from this exploratory survey in several fields of the Zaire province and territory of Mbanza Kongo confirmed, for the first time, the presence of cassava root necrosis in Angola, similar to CBSD, as identified in western DRC
Assessing the severity and the incidence of Cassava Root Necrosis Disease (CRND) in western Democratic Republic of Congo
Open Access ArticleCassava is the staple food in the Democratic Republic of Congo (DRC) where both the roots and leaves are consumed. This crop is susceptible to several viral diseases, including Cassava Mosaic Disease(CMD) and Cassava Brown Streak Disease(CBSD) in eastern DRC. Following earlier studies that show root necrosis occurring in western DR Care not due to CBSD but to Cassava Root Necrosis Disease (CRND), an exploratory survey was conducted in western DRC from 2016 to 2017 in order to determine the distribution, the severity and the incidence of this disease (previously known as CBSD-like disease). NGS ( Next Generation Sequencing) results confirmed all the previous negative results obtained using PCR and CBSV primers. This suggests that microorganisms such as bacteria or fungi could be responsible for cassava root necrosis in western DRC and is not CBSD as predicted. Five provinces (Bas-Congo, Kinshasa, Bandundu, Equateur and Kasai-Oriental) were surveyed and data were collected according to the harmonized protocols adopted by countries within the West African Virus Epidemiology (WAVE) project. Statistical tests (ANOVA) performed on our data showed that CRND severity did not vary significantly among the provinces of Kinshasa, Bandundu and Bas-Congo which are the areas most affected by the disease. Bas-Congo and Kinshasa provinces presented the highest maximum disease severity (score 3 and 5 respectively), while Equateur province had the lowest disease severity score. Equateur province also had the highest percentage of healthy plants and few plants presented mild symptoms. The overall average of cassava root necrosis severity in western DRC ranged around 1.88 ± 0.08, an approximate score of 2. The overall mean incidence of CRND in western DRC was 22.24 ± 2.4% but reached 100% in localities considered as hotspots (Lukuakua in Bas-Congo and Nguma in Plateau des Batékés). The behaviour of cassava varieties against CRND is similar with CBSD in East Africa, most of improved varieties and landraces are susceptible to both diseases. Correlation analyses showed a positive correlation (r = 0.6940) between severity and incidence of CRND. Therefore, Bas-Congo province is the most affected province, while the province of Equateur is the least affected province in western DRC. Further investigations, including genomic surveillance, should also be conducted in the eastern DRC where CBSD is confirmed to know if CRND is found in conjunction with CBSD and to report possible instances of mixed infections. For medium-term disease control, our study suggests that the development and deployment of control measures including cultivars with resistance to CRND and CBSD should be a priority
Affordable & Accessible Housing for All Minnesotans: Equitable Investment in Housing for People with Disabilities
Without ensuring that housing is also accessible, Minnesotaâs efforts to increase affordable housing is leaving out a segment of our community, Minnesotanâs with disabilities. Minnesota must commit to ensuing that every man, every woman, every child in Minnesota, without exception, has a safe, affordable, dignified and ACCESSIBLE place to call home
Attempts to identify Cassava Brown Streak Virus in western Democratic Republic of Congo
Open Access ArticleRoot necrosis similar to those of the cassava brown streak disease (CBSD) were observed on cassava in western provinces of the Democratic Republic of Congo (DR.Congo) in the early 2000âs. However molecular laboratory diagnosis were not able to detect any causative agent responsible for the attacks, hence, the disease related to these symptoms was named CBSD-like disease.
In order to assess the distribution and the incidence of the CBSD-like disease, surveys were carried out in four western provinces, comprising, Kwango and Kwilu, Sud Ubangi, Kinshasa and Kongo Central. CBSD-like disease was observed in all surveyed provinces on the basis of root symptoms because foliar symptoms were different to those of the documented cases of CBSD in other parts of east Africa. CBSD-like disease incidence was high in Kongo Central and Sud Ubangi, exceeding an average of 50 %, but low in Kwango and Kwilu (32.8%) and in Kinshasa (19.1%).
During the surveys, cassava leaf samples were collected for lab identification of the causal agent. PCR diagnosis was done on these samples using primers specific for the two known CBSVs. All samples tested negative with no amplification of DNA fragments of the correct size. Thus, further analysis on the causative organism is needed using Next Generation Sequencing (NGS) approaches. NGS approaches will help also to identify the causative organism in other Central Africa countries (Angola, Congo-Brazzaville and Gabon) where such cassava root necrosis have been reported or are suspected
Mental health care for irregular migrants in Europe: Barriers and how they are overcome
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited
Diversity and distribution of whiteflies colonizing cassava in eastern Democratic Republic of Congo
Open Access Journal; Published online: 19 Sep 2022The present study characterizes Bemisia tabaci and Bemisia afer from cassava in eastern Democratic Republic of Congo (DRC). The Mitochondrial COI sequencing revealed the occurrence of six cassava B. tabaci mitotypes, which were designated into four haplogroups (SSA-ECA, SSA-CA, SSA2, and SSA-ESA) using KASP SNP genotyping. SSA-ECA (72%) was the most prevalent and occurred in the northern part of the surveyed area, in the Ituri and Nord/Sud-Kivu provinces, whilst SSA-CA (21%) was present in the south, primarily in Haut-Katanga. SSA-ECA was predominant in the areas of north-eastern DRC most severely affected by cassava brown streak disease and was also reported in the new outbreak area in Pweto territory, Haut-Katanga, in the south. Bemisia afer comprised two major clusters with 85.5% of samples in cluster one, while the rest were in cluster two, which has no reference sequence in GenBank. This study provides important information on the genetic diversity of B. tabaci and B. afer in eastern DRC. This knowledge will be used as a basis for further studies to understand and to identify the role of whitefly haplogroups, their population densities and consequences for virus epidemics and spread as well as leading to improved vector and virus management strategies
- âŠ