• 제목/요약/키워드: Nigeria

검색결과 322건 처리시간 0.024초

Geochemistry and Petrogenesis of Pan-african Granitoids in Kaiama, North Central, Nigeria

  • Aliyu Ohiani Umaru;Olugbenga Okunlola;Umaru Adamu Danbatta;Olusegun G. Olisa
    • 자원환경지질
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    • 제56권3호
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    • pp.259-275
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    • 2023
  • Pan African granitoids of Kaiama is comprised of K-feldspar rich granites, porphyritic granites, and granitic gneiss that are intruded by quartz veins and aplitic veins and dykes which trend NE-SW. In order to establish the geochemical signatures, petrogenesis, and tectonic settings of the lithological units, petrological, petrographical, and geochemical studies was carried out. Petrographic analysis reveals that the granitoids are dominantly composed of quartz, plagioclase feldspar, biotite, and k-feldspar with occasional muscovites, sericite, and opaque minerals that constitute very low proportion. Major, trace, and rare earth elements geochemical data reveal that the rocks have moderate to high silica (SiO2=63-79.7%) and alumina (Al2O3=11.85-16.15) contents that correlate with the abundance of quartz, feldspars, and biotite. The rocks are calc-alkaline, peraluminous (ASI=1.0-<1.2), and S-type granitoids sourced by melting of pre-existing metasedimentary or sedimentary rocks containing Al, Na, and K oxides. They plot dominantly in the WPG and VAG fields suggesting emplacement in a post-collisional tectonic setting. On a multi-element variation diagram, the granitoids show depletion in Ba, K, P, Rb, and Ti while enrichment was observed for Th, U, Nd, Pb and Sm. Their rare-earth elements pattern is characterized by moderate fractionation ((La/Yb)N=0.52-38.24) and pronounced negative Eu-anomaly (Eu/Eu*=0.02-1.22) that points to the preservation of plagioclase from the source magma. Generally, the geochemical features of the granitoids show that they were derived by the partial melting of crustal rocks with some input from greywacke and pelitic materials in a typical post-collisional tectonic setting.

Mapping Publication Pattern in African Journal of Library, Archives and Information Science, 2009-2018: An Informetric Study

  • Amusan, Blessing Babawale;Adeyoyin, Samuel Olu
    • International Journal of Knowledge Content Development & Technology
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    • 제12권1호
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    • pp.17-34
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    • 2022
  • This informetrics study was conducted to find out the distribution of articles and authors that published in African Journal of Library, Archives and Information Studies [AJLAIS]) from 2009 to 2018; considering the year-wise growth of research articles; authorship pattern and collaboration ratio; subject and geographical distributions of authors; and authors' productivity level. A descriptive informetrics research design was adopted. Quota sampling technique was used to select all the articles published within the ten-year period. Data collected through a self-designed checklist was analyzed using frequency count and percentage. The findings revealed that 141 articles, contributed by 266 authors were published by AJLAIS during the period. An annual average growth of 1.20% was recorded. Overall year-wise authorship pattern revealed that majority of articles (62.41%) published in AJLAIS were multiple authored. Also, articles on Informetrics and ICT dominated the journal. Some subject areas not covered were identified such as: indexing and serial collections management. Average collaborative index across the 10-year period for the journal was 0.62. South Africa and Nigeria were the two major prolific contributors to AJLAIS, just as evidence-based research papers of survey type (65.25%) were the most common to the journal. There should be increased numbers of articles in each edition over the coming years, and awareness should be created by the publishers to familiarize the researchers with the publishing requirements of the journal. Also, LIS researchers should concentrate more on areas usually left untouched by previous studies. The study is original as no other similar study was found on publication pattern of articles in AJLAIS covering a ten year period of 2009-2018. The findings of the study will also serve as a feedback mechanism for the Publisher of the Journal and LIS researchers on how to improve the journal and LIS research in general.

토파즈의 人工着色 處理를 위한 硏究(I) : 世界 主要 産地別 토파즈의 鑛物學的 및 化學的 特性 (A Study of Coloration of Topaz(I): Mineralogical and Chemical Study on the Topaz Selected from Some Localities of the World)

  • 한이경;박맹언;장영남
    • 한국광물학회지
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    • 제5권2호
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    • pp.109-121
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    • 1992
  • 본 연구는 토파즈의 인공착색 처리 방법을 설정하기 위하여 브라질, 중국, 인도, 나이지리아, 스리랑카 등 5개국에서 산출된 토파즈를 대상으로, 전자현미분석(EPMA), 중성자활성분석(NAA), X선 회절분석, 라만 분광분석, 주사현미경(SEM), 부식시험, 굴절률측정, 비중측정, 유체 포유물 관찰 등의 실험을 실시하여 광물학적, 화학적 특성에 관한 연구를 수행하였다. 연구 결과 토파즈는 산지에 따라 화학적, 구조적 및 물리적 특성의 차이를 나타내었으며 특히, F와 OH 고용체 함량의 차이는 물리적, 구조적 특성과 밀접한 관련성이 있음이 확인되었다. F에 대한 OH로 치환정도가 가장 높은 인도산 토파즈는 굴절률, 단위포상수 b, 단위포 체적 및 ${\Delta}021$값이 가장 크고, 비중값은 가장 작으며 스리랑카산, 중국산, 브라질산, 나이지리아산순으로 F에 대한 OH로 치환 정도가 낮다. F에 대한 OH로 치환정도가 가장 낮은 나이지리아산 토파즈는 굴절률, 단위포상수 b, 단위포 체적 및 ${\Delta}021$값이 가장 작고, 비중값은 가장 크다. 토파즈내에 함유되는 미량원소종은 Na, Fe, Br, Co, Ce, La, Sm, Th, Au, Sc, Cr 등이며 이러한 미량원소의 정성정량적 특성은 물리적 특성에는 거의 영향을 미치지 않았다. 라만 분광분석 결과 토파즈의 피크는 산지에 따라 강도의 차이를 나타내었으며 브라질산과 인도산은 455∼458($cm^{-1}$)근처의 피크, 중국산은 282∼284($cm^{-1}$) 근처의 피크가 나타나지 않았다. 산지에 따른 결정구조결함 특성은 주로 point-bottom pit의 negative crystal defect(인도산, 나이지리아산)와 curl-bottom pit의 net work defect(브라질산, 중국산)로 구분되며, 결정내에 발달하는 미세한 균열을 따라 형성된 선결함 양상(linear defect)을 보여준다. 유체 포유물의 특징은 브라질산이 액상 $CO_2$를 가지는 III형이고, 중국산에는 유체 포유물이 거의 관찰되지 않으며 단지 $10{\mu}m$이하의 매우 작은 크기인 초생포유물의 극소량 존재한다. 인도산은 기체가 풍부한 II형이고, 나이지리아산은 암염, 실바이트 등의 고체 포유물을 함유하는 IV형이며 스리랑카산은 거의 대부분의 유체 포유물이 2차 생성의 I형이 주로 형성되어 있다. 본 연구의 결과는 광물학적 특성의 차이를 갖는 산지별 토파즈의 인공착색을 위한 처리 방법을 설정하는 유용한 기초 자료로 이용될 수 있을 것이다.

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멀티도어코트하우스제도: 기원, 확장과 사례분석 (The Multi-door Courthouse: Origin, Extension, and Case Studies)

  • 정용균
    • 한국중재학회지:중재연구
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    • 제28권2호
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    • pp.3-43
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    • 2018
  • The emergence of a multi-door courthouse is related with a couple of reasons as follows: First, a multi-door courthouse was originally initiated by the United States government that increasingly became impatient with the pace and cost of protracted litigation clogging the courts. Second, dockets of courts are overcrowded with legal suits, making it difficult for judges to handle those legal suits in time and causing delays in responding to citizens' complaints. Third, litigation is not suitable for the disputant that has an ongoing relationship with the other party. In this case, even if winning is achieved in the short run, it may not be all that was hoped for in the long run. Fourth, international organizations such as the World Bank, UNDP, and Asia Development Bank urge to provide an increased access to women, residents, and the poor in local communities. The generic model of a multi-door courthouse consists of three stages: The first stage includes a center offering intake services, along with an array of dispute resolution services under one roof. At the second stage, the screening unit at the center would diagnose citizen disputes, then refer the disputants to the appropriate door for handling the case. At the third stage, the multi-door courthouse provides diverse kinds of dispute resolution programs such as mediation, arbitration, mediation-arbitration (med-arb), litigation, and early neutral evaluation. This study suggests the extended model of multi-door courthouse comprised of five layers: intake process, diagnosis and door-selection process, neutral-selection process, implementation process of dispute resolution, and process of training and education. One of the major characteristics of extended multi-door courthouse model is the detailed specification of individual department corresponding to each process within a multi-door courthouse. The intake department takes care of the intake process. The screening department plays the role of screening disputes, diagnosing the nature of disputes, and determining a suitable door to handle disputes. The human resources department manages experts through the construction and management of the data base of mediators, arbitrators, and judges. The administration bureau manages the implementation of each process of dispute resolution. The education and training department builds long-term planning to procure neutrals and experts dealing with various kinds of disputes within a multi-door courthouse. For this purpose, it is necessary to establish networks among courts, law schools, and associations of scholars in order to facilitate the supply of manpower in ADR neutrals, as well as judges in the long run. This study also provides six case studies of multi-door courthouses across continents in order to grasp the worldwide picture and wide spread phenomena of multi-door courthouse. For this purpose, the United States and Latin American countries including Argentina and Brazil, Middle Eastern countries, and Southeast Asian countries (such as Malaysia and Myanmar), Australia, and Nigeria were chosen. It was found that three kinds of patterns are discernible during the evolution of a multi-door courthouse model. First, the federal courts of the United States, land and environment court in Australia, and Lagos multi-door courthouse in Nigeria may maintain the prototype of a multi-door courthouse model. Second, the judicial systems in Latin American countries tend to show heterogenous patterns in terms of the adaptation of a multi-door courthouse model to their own environments. Some court systems of Latin American countries including those of Argentina and Brazil resemble the generic model of a multi-door courthouse, while other countries show their distinctive pattern of judicial system and ADR systems. Third, it was found that legal pluralism is prevalent in Middle Eastern countries and Southeast Asian countries. For example, Middle Eastern countries such as Saudi Arabia have developed various kinds of dispute resolution methods, such as sulh (mediation), tahkim (arbitration), and med-arb for many centuries, since they have been situated at the state of tribe or clan instead of nation. Accordingly, they have no unified code within the territory. In case of Southeast Asian countries such as Myanmar and Malaysia, they have preserved a strong tradition of customary laws such as Dhammthat in Burma, and Shriah and the Islamic law in Malaysia for a long time. On the other hand, they incorporated a common law system into a secular judicial system in Myanmar and Malaysia during the colonial period. Finally, this article proposes a couple of factors to strengthen or weaken a multi-door courthouse model. The first factor to strengthen a multi-door courthouse model is the maintenance of flexibility and core value of alternative dispute resolution. We also find that fund raising is important to build and maintain the multi-door courthouse model, reflecting the fact that there has been a competition surrounding the allocation of funds within the judicial system.

해외진출 한국 기업의 대테러 경호${\cdot}$경비 전략에 관한 연구 (A Study on the Counter-Terrorism and Security Strategy for Korean Companies Engaged in the Overseas Business)

  • 최진태
    • 시큐리티연구
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    • 제13호
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    • pp.507-528
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    • 2007
  • 테러는 지금 이 시간에도 전 세계 곳곳에서 연쇄적으로 발생하고 있어 테러의 시대에 살아가고 있음을 실감나게 하고 있다. 그 동안 테러는 특정 지역에서만 발생하는 국지적인 문제이며, 정치적인 문제만으로 인식하는 경향이 있었다. 최근에 발생하고 있는 테러 사건 중 주목할 만한 것은 해외에서 활동하고 있는 기업과 기업 소속 근로자들이 테러조직의 공격 대상으로 등장하고 있다는 것이다. 기업이 테러의 공격 대상이 된 것은 최근의 일이 아니다. 현대적 의미의 테러의 태동기라고 할 수 있는 1960년대에도 기업과 기업인, 그리고 근로자들에 대한 테러는 있었다. 그러나 세계 여러 나라의 기업들이 테러를 중대한 문제로 인식하지 않고 있었다. 지금은 상황이 변했다. 테러조직들이 국제적인 대도시에 위치한 다국적 기업의 본사는 물론이고 중남미 그리고 아프리카의 건설 현장까지 공격하기 시작했다. 한국의 기업들도 더 이상 예외가 아니다. 2005년 6월 그리고 2006년 1월에 나이지리아에서 발생한 대우건설 근로자 납치사건 그리고 현대중공업 선박에 대한 무장 공격 사건 등은 해외에 진출한 한국 기업 역시 테러로부터 결코 안전하지 않다는 것을 증명했다. 이에 따라 현재 해외에 진출하여 활동하고 있는 기업뿐만 아니라 향후 해외 진출을 고려하는 기업들도 테러에 대한 대책을 마련하지 않으면 안 된다는 것을 교훈으로 남겼다고 할 것이다. 테러 조직이 저지를 수 있는 여러 가지 공격 유형에 대응할 수 있는 전략과 전술을 미리 새워 유사시를 대비하는 노력을 통해 새롭게 등장하고 있는 테러로부터 안전한 기업 경영의 토대를 구축하는 노력을 기울려야 할 것이다.

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Clinical experience in managing temporomandibular joint ankylosis: five-year appraisal in a Nigerian subpopulation

  • Braimah, Ramat;Taiwo, Abdurrazaq;Ibikunle, Adebayo;Oladejo, Taoreed;Adeyemi, Mike;Adejobi, Francis;Abubakar, Siddiq
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제44권3호
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    • pp.112-119
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    • 2018
  • Objectives: Temporomandibular joint ankylosis (TMJA) is a joint pathology caused by bony and/or fibrous adhesion of the joint apparatus, resulting in partial or total loss of function. Materials and Methods: This is a retrospective study conducted between 2012 and 2016 in the northwest region of Nigeria. The data retrieved includes gender, age, etiology of ankylosis, duration of ankylosis, laterality of ankylosis, type of imaging technique, type of airway management, types of incision, surgical procedure, mouth opening, interpositional materials used, and complications. Results were presented as simple frequencies and descriptive statistics. Results: Thirty-six patients with TMJA were evaluated during the study period. There were 21 males (58.3%) and 15 females (41.7%), yielding a male:female ratio of 1.4:1. The patients' age ranged from 5 to 33 years with $mean{\pm}standard$ deviation ($13.8{\pm}6.6years$). Thirty-five cases (97.2%) were determined to be true/bony ankylosis, while only 1 case (2.8%) was false/fibrous ankylosis. Most of the TMJA cases (16 cases, 44.4%) were secondary to a fall. In our series, the most commonly utilized incision was the Bramley-Al-Kayat (15 cases, 41.7%). The mostly commonly performed procedures were condylectomies and upper ramus ostectomies (12 cases each, 33.3%), while the most commonly used interpositional material was temporalis fascia (14 cases, 38.9%). The complications that developed included 4 cases (11.1%) of severe hemorrhage, 1 case (2.8%) of facial nerve palsy, and 1 case (2.8%) of re-ankylosis. Conclusion: Plain radiographs, with their shortcomings, still have significant roles in investigating TMJA. Aggressive postoperative physiotherapy for a minimum of 6 months is paramount for successful treatment.

Chromosome 22 LD Map Comparison between Korean and Other Populations

  • Lee, Jong-Eun;Jang, Hye-Yoon;Kim, Sook;Yoo, Yeon-Kyeong;Hwang, Jung-Joo;Jun, Hyo-Jung;Lee, Kyu-Sang;Son, Ok-Kyung;Yang, Jun-Mo;Ahn, Kwang-Sung;Kim, Eug-Ene;Lee, Hye-Won;Song, Kyu-Young;Kim, Hie-Lim;Lee, Seong-Gene;Yoon, Yong-Sook;Kimm, Ku-Chan;Han, Bok-Ghee;Oh, Berm-Seok;Kim, Chang-Bae;Jin, Hoon;Choi, Kyoung-O.;Kang, Hyo-Jin;Kim, Young-J.
    • Genomics & Informatics
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    • 제6권1호
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    • pp.18-28
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    • 2008
  • Single nucleotide polymorphisms (SNPs) are the most abundant forms of human genetic variations and resources for mapping complex genetic traits and disease association studies. We have constructed a linkage disequilibrium (LD) map of chromosome 22 in Korean samples and compared it with those of other populations, including Yorubans in Ibadan, Nigeria (YRI), Centre d'Etude du Polymorphisme Humain (CEPH) reference families (CEU), Japanese in Tokyo (JPT) and Han Chinese in Beijing (CHB) in the HapMap database. We genotyped 4681 of 111,448 publicly available SNPs in 90 unrelated Koreans. Among genotyped SNPs, 4167 were polymorphic. Three hundred and five LD blocks were constructed to make up 18.6% (6.4 of 34.5 Mb) of chromosome 22 with 757 tagSNPs and 815 haplotypes (frequency $\geq$ 5.0%). Of 3430 common SNPs genotyped in all five populations, 514 were monomorphic in Koreans. The CHB + JPT samples have more than a 72% overlap with the monomorphic SNPs in Koreans, while the CEU + YRI samples have less than a 38% overlap. The patterns of hot spots and LD blocks were dispersed throughout chromosome 22, with some common blocks among populations, highly concordant between the three Asian samples. Analysis of the distribution of chimpanzee-derived allele frequency (DAF), a measure of genetic differentiation, Fst levels, and allele frequency difference (AFD) among Koreans and the HapMap samples showed a strong correlation between the Asians, while the CEU and YRI samples showed a very weak correlation with Korean samples. Relative distance as a quantitative measurement based upon DAF, Fst, and AFD indicated that all three Asian samples are very proximate, while CEU and YRI are significantly remote from the Asian samples. Comparative genome-wide LD studies provide useful information on the association studies of complex diseases.

그라비올라 잎 추출물의 이화학적 특성 및 항산화 활성 (Antioxidative Effects and Chemical Characteristics of Annona muricata Leaf Extracts)

  • 김영완;김태훈;안희영;조영수
    • 생명과학회지
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    • 제28권5호
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    • pp.540-546
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    • 2018
  • 그라비올라(Annona muricata) 잎으로부터 정제수, 에탄올, 메탄올로 추출하여 수율, 총 페놀성 화합물과 이에 속하는 flavonoid 함량, 미네랄 함량을 측정하고 DPPH free radical scavenging 활성, Cu/Fe 환원력, 간 조직의 microsome 생체막의 지질과산화 억제능 및 linoleic acid를 이용한 지질과산화, ${\beta}$-Carotene 탈색화 정도를 비교검토하였다. 그라비올라 잎의 수율은 수용성 추출물이 가장 높았으며(1.76%), 총 페놀성 화합물 함량은 그라비올라의 메탄올 추출물에서 가장높았으나 페놀성 화합물에 속하는 폴리페놀 함량은 에탄올 추출물에서 가장 높은 결과를 나타내었고, 미네랄 함량은 Ca, K, Mg, Na, Mn의 순으로 높게 측정되었다. DPPH를 이용한 radical 소거능을 측정한 결과, 그라비올라 잎의 에탄올과 메탄올 추출물에서 대조구인 BHT 0.05%와 가장 근접한 활성을 나타내었다. Fe와 Cu의 환원력은 모든 군에서 농도 의존적으로 증가하였고, 그 중 에탄올과 메탄올 추출물에서 Cu/Fe 환원력 활성이 매우 강하였다. 그러나 간 조직을 이용하여 측정하는 지질과산화 억제활성과 TBA법으로 지질과산화를 측정한 결과, 그라비올라 잎의 에탄올 추출물에서 지질과산화 억제능을 보였다. ${\beta}$-Carotene bleaching에서 높은 lipid peroxyl 라디칼 소거 활성이 있음을 확인할 수 있었다. 따라서, 그라비올라 잎은 기능성 식품의 개발을 위한 천연 항산화제 소재로서 활용 될 수 있을 것으로 판단되어진다.

Mineralogy and Geochemistry of Shale Deposits in the Lower Anambra Basin, Nigeria: Implication for Provenance, Tectonic Setting and Depositional Environment

  • Olugbenga Okunlola;Agonsi Udodirim Lydia;Aliyu Ohiani Umaru;Raymond Webrah Kazapoe;Olusegun G. Olisa
    • 자원환경지질
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    • 제56권6호
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    • pp.799-816
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    • 2023
  • Mineralogical and geochemical studies of shales within the Lower Anambra Basin was conducted to unravel the depositional environment, provenance, maturity, paleo-weathering conditions, and tectonic settings. Mineralogical studies conducted using X-ray diffraction analysis revealed that the samples were composed of kaolinite, montmorillonite, chlorite, and illite. KaolinIite is the dominant mineral, constituting approximately 41.5% of the bulk composition, whereas the non-clay minerals are quartz, ilmenite, and sillimanite. Geochemical analysis showed a predominance of SiO2, Al2O3, and Fe2O3 contents of the shale samples with mean values of 52.29%, 14.09%, and 6.15% for Imo Shale (IS); 52.31%, 16.70%, and 7.39% for Mamu Shale (MS); 43.21%, 21.33%, and 10.36% for Enugu Shale (ES); 53.35%, 15.64%, and 7.17% for Nkporo Shale (NS); and 51.24%, 17.25%, and 7.78% for Agwu Shale (AS). However, the shales were depleted in Na2O, MgO, K2O, MnO, TiO2, CaO, and P2O5. The trace element ratios of Ni/Co and Cu/Zn of the shale suggest an oxic depositional environment. The average SiO2 vs. Al2O3 ratio of the shales indicated textural maturity. Compared to the PAAS standard, the shales plot below the PAAS value of 0.85, suggesting a high degree of maturity and intensive chemical weathering, further confirmed on a CIA vs. PIA plot. On log (K2O/Na2O) against SiO2 and tectonic setting discriminant function diagrams, the shales plot mostly in the field of passive continental margin tectonic setting. The discriminant function diagrams as well as Al2O3/TiO2 ratio of the shales showed that they were derived from a mixed source (mafic and intermediate igneous rocks).

Potentials of Phyllanthus amarus, Viscum album and Moringa oleifera supplements to mitigate heat stress in female rabbits in humid tropics

  • Olatunji Abubakar Jimoh;Blessing Oluwaseun Olakanye;Ayoola Mercy Ajewole;Saanu Olajumoke Akinbuyide;Johnson Sunday Adetifa;Abdul-Quadri Ayodeji Jimoh;Adewale Oluwatosin Mayowa;Feyisayo Pemisire Adesina
    • Journal of Animal Science and Technology
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    • 제66권1호
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    • pp.79-92
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    • 2024
  • Global warming is a key challenge subjecting animals to heat stress conditions resulting in multiple physiological alterations in tropical climate. Dietary approach seems to be the more friendly approach to curb the adverse effects of heat stress in rabbits. Some herbs have been categorized to have high potential for promotion of immune responses for amelioration of heat stress. Thus, this research aims to evaluate the potential of Mistletoe (Viscum album), Moringa (Moringa oleifera) and Phyllanthus (Phyllanthus amarus) leaf meal as herbal supplements for the alleviation of heat stress in female rabbits by measuring improvement in sex and stress hormonal responses in serum biochemistry. 80 Rabbit does were exposed to 4 dietary groups supplemented with each of Mistletoe, Moringa, Phyllanthus and a control in an 84-day trial at the summit of thermal stress in South west Nigeria. Growth indices were monitored throughout the study, blood samples were compiled at the end of the trial to assess serum biochemistry, stress and sex hormonal responses of the Does using standard protocols. The results revealed that final weight and weight gain of Does fed on Phyllanthus were significantly (p < 0.05) higher (11.46% and 14.25%, respectively) than Does on control. The herbal supplements enhance glucose, protein, albumin and globulin, reduced cholesterol, and creatinine of Does under heat stress conditions. Among the herbal treatment groups, mistletoe, moringa and phyllanthus had 12.42%, 18.39% and 16.90%, respectively, lower corticosterone than control groups which had 39.76ng/ml. Triiodothyronine of Does fed control were significantly (p < 0.05) lower than Does on Moringa oleifera and Phyllanthus amarus supplements. Estradiol and Follicle stimulating hormone of rabbit Does fed on moringa supplement were significantly (p < 0.05) higher than other treatments. In conclusion, the herbal supplements tend to mitigate the detrimental outcome of thermal stress on Does by suppressing stress hormones. Moringa oleifera and Phyllanthus amarus enhanced sex hormones while Phyllanthus amarus confered growth promoting effects on the Does.