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Current situation and future trends for beef production in the United States of America - A review

  • Drouillard, James S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.7
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    • pp.1007-1016
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    • 2018
  • USA beef production is characterized by a diversity of climates, environmental conditions, animal phenotypes, management systems, and a multiplicity of nutritional inputs. The USA beef herd consists of more than 80 breeds of cattle and crosses thereof, and the industry is divided into distinct, but ofttimes overlapping sectors, including seedstock production, cow-calf production, stocker/backgrounding, and feedlot. Exception for male dairy calves, production is predominantly pastoral-based, with young stock spending relatively brief portions of their life in feedlots. The beef industry is very technology driven, utilizing reproductive management strategies, genetic improvement technologies, exogenous growth promoting compounds, vaccines, antibiotics, and feed processing strategies, focusing on improvements in efficiency and cost of production. Young steers and heifers are grain-based diets fed for an average of 5 months, mostly in feedlots of 1,000 head capacity or more, and typically are slaughtered at 15 to 28 months of age to produce tender, well-marbled beef. Per capita beef consumption is nearly 26 kg annually, over half of which is consumed in the form of ground products. Beef exports, which are increasingly important, consist primarily of high value cuts and variety meats, depending on destination. In recent years, adverse climatic conditions (i.e., draught), a shrinking agricultural workforce, emergence of food-borne pathogens, concerns over development of antimicrobial resistance, animal welfare/well-being, environmental impact, consumer perceptions of healthfulness of beef, consumer perceptions of food animal production practices, and alternative uses of traditional feed grains have become increasingly important with respect to their impact on both beef production and demand for beef products. Similarly, changing consumer demographics and globalization of beef markets have dictated changes in the types of products demanded by consumers of USA beef, both domestically and abroad. The industry is highly adaptive, however, and responds quickly to evolving economic signals.

Ethnobotanical survey and threats to medicinal plants traditionally used for the management of human diseases in Nyeri County, Kenya

  • Kamau, Loice Njeri;Mbaabu, Peter Mathiu;Mbaria, James Mucunu;Gathumbi, Peter Karuri;Kiama, Stephen Gitahi
    • CELLMED
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    • v.6 no.3
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    • pp.21.1-21.15
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    • 2016
  • In Kenya, traditional knowledge on herbal medicine has remained a mainstream source of maintaining wellbeing for generations in many communities. However, the knowledge has been eroded in the course of time due to sociocultural dynamics virtually advanced by Christianity and formal education especially in the Kikuyu community. The study documented current ethnobotanical knowledge and threat to the traditional knowledge on medicinal plants among the Kikuyu community. A survey was carried out in Mathira, Tetu, Kieni, Othaya, Mukurweini, and Nyeri Town constituencies. Thirty practicing herbalists were purposively sampled; 5 per constituency. Data was obtained through semi - structured questionnaires and analyzed both qualitatively and quantitatively. A total of 80 ailments treated using 111 medicinal plant species distributed within 98 genera and 56 families were documented. Prevalent communicable diseases treated using herbal medicine included; gonorrhea (17.5%), malaria (15%), respiratory infections (12%), colds (10%) and amoebiasis (10%). Non-communicable diseases were; joint pains (11.1%), ulcers/hyperacidity (8.7%), high blood pressure (8.7%), intestinal worms (11.1%) and arthritis/gout (10%). Frequently harvested plant materials were; roots, barks and leaves. The study concluded that, traditional medicine practitioners in Nyeri County possessed wide knowledge of herbal medicine but this knowledge was on the verge of disappearing as it was largely a preserve of the aged generation. The study recommended massive campaign about the benefits of using herbal medicine in the study area. Further pharmacological studies are recommended on the mentioned plant species aimed at establishing their efficacy and safety as well as standardization as potential drugs.

Construction Partnering on Alternative Project Delivery Methods: A Case Study of Construction Manager/General Contractor Partnered Transportation Projects

  • Adamtey, Simon A.;Kereri, James O.
    • Journal of Construction Engineering and Project Management
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    • v.9 no.4
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    • pp.1-15
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    • 2019
  • Since its adoption by the transportation sector in the early 1990s, partnering has been broadly used with the traditional delivery method by many agencies with significant reported benefits. During the same era, a number of transportation agencies (DOTs) started experimenting with a wide variety of alternative project delivery methods (APDMs) aimed at improving the delivery of highway construction projects. The effect of collaborative working strategies such as partnering, together with the APDMs have become somehow interrelated posing a potential challenge on how to effectively integrate partnering as a concept in the APDMs. The salient question has been if the collaborative nature of these APDMs has affected how partnering is being used by state DOTs. Through an extensive literature review, analysis of 32 CMGC RFPs/RFQs and review of three CMGC case studies, the study found that there is limited information in state DOT documents that show procedures on the usage of partnering with CMGC projects. Majority of DOTs are relying on the inherent nature of the CMGC contract to promote healthy collaborative practices and there is the need to consider partnering during preconstruction and construction separately to cater for any personnel change over. The study also revealed that partnering may become less important at the construction phase due to overlap between partnering and CMGC practices. In support of this finding, a CMGC partnering model was developed that can be adopted by DOTs. This paper contributes to both research and practice by expanding the existing knowledge on partnering on APDMs.

Development of a multi channel measurement system for the cellular respiration measurement (세포 호흡량 측정용 다채널 측정 시스템 개발)

  • Nam, Hyun-Wook;Park, Jung-Il;KimPak, Young-Mi;Pak, James Jung-Ho
    • Journal of Sensor Science and Technology
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    • v.19 no.1
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    • pp.36-42
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    • 2010
  • This paper describes a multi channel measurement system which can measure the cellular respiration level in a solution containing cells by using a Clark-type sensor with the solution temperature control unit. The Clark-type sensor can measure the cellular respiration level in the solution because it can measure the reduction current depending on the dissolved oxygen level in the solution. This measurement system was maintained the temperature within ${\pm}0.1^{\circ}C$ of the setting temperature value by on/off control method in order to measure the precise cellular respiration level. The measurement system showed that the applied voltage to the working electrode was very stable(-0.8 V$\pm$ 0.0071 V) by using proportional control method. From the current measurement, the response time and the linearity correlation coefficient were 25 sec and 0.94, respectively, which are very close to the results of the commercial product. Using this system and the fabricated Clarktype sensor, the average ratio of the uncoupled OCR(oxygen consumption rate) to the coupled OCR was 1.35 and this is almost the same as that obtained from a commercial systems.

Electrochemical Immunosensor Based on the ZnO Nanorods Inside PDMS Channel for H7N9 Influenza Virus Detection (PDMS 채널 내부에 성장된 산화아연 나노막대를 이용한 H7N9 인플루엔자 바이러스 전기화학 면역센서)

  • Han, Ji-Hoon;Lee, Dongyoung;Pak, James Jungho
    • Journal of Sensor Science and Technology
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    • v.23 no.4
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    • pp.278-283
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    • 2014
  • In this study, we propose an immunosensor using zinc oxide nanorods (NRs) inside PDMS channel for detecting the influenza A virus subtype H7N9. ZnO with high isoelectric point (IEP, ~9.5) makes it suitable for immobilizing proteins with low IEP. In this proposed H7N9 immunosensor structure ZnO NRs were grown on the PDMS channel inner surface to immobilize H7N9 capture antibody. A sandwich enzyme-linked immunosorbent assay (ELISA) method with was used 3,3',5,5' tetramethylbenzidine (TMB) for detecting H7N9 influenza virus. The immunosensor was evaluated by amperometry at various H7N9 influenza antigen concentrations (1 pg/ml - 1 ng/ml). The redox peak voltage and current were measured by amperometry with ZnO NWs and without ZnO NWs inside PDMS channel. The measurement results of the H7N9 immunosensor showed that oxidation peak current of TMB at 0.25 V logarithmically increased from 2.3 to 3.8 uA as the H7N9 influenza antigen concentration changed from 1 pg/ml to 1 ng/ml. And then we demonstrated that ZnO NRs inside PDMS channel can improve the sensitivity of immunosensor to compare non-ZnO NRs inside PDMS channel.

Differences in Ethylene and Fruit Quality Attributes during Storage in New Apple Cultivars

  • Yoo, Jingi;Lee, Jinwook;Kwon, Soon-Il;Chung, Kyeong Ho;Lee, Dong Hoon;Choi, In Myung;Mattheis, James P.;Kang, In-Kyu
    • Horticultural Science & Technology
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    • v.34 no.2
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    • pp.257-268
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    • 2016
  • Physiological characteristics of five new apple cultivars from the Korean apple breeding program were evaluated as a function of harvest time and storage after harvest. Internal ethylene concentration (IEC), flesh firmness, soluble solids concentration (SSC), and titratable acidity (TA) were measured in 'Summer Dream', 'Summer King', 'Green Ball', 'Picnic', and 'Hwangok' apples at harvest, during shelf life at $20^{\circ}C$, and one day after cold storage at $0.5^{\circ}C$ in air. IEC increased during shelf life in 'Summer Dream', 'Summer King', and 'Green Ball' but not in 'Picnic' or 'Hwangok', regardless of harvest time. Flesh firmness decreased towards harvest time and decreased gradually with time in cold storage only in the former three cultivars. In turn, IEC increased during cold storage in the first three cultivars but not for the last two cultivars, irrespective of harvest time. Changes in SSC and TA did not consistently relate to harvest time or storage period but TA tended to decrease as IEC increased. Furthermore, IEC was negatively correlated with flesh firmness except in the 'Green Ball' cultivar but the significance level was much greater in 'Summer Dream' and 'Summer King' (p < 0.0001) than in 'Picnic' (p < 0.01) or 'Hwangok' (p < 0.05) cultivars. Flesh firmness was positively correlated with TA in the first three cultivars but not in the last two cultivars. Overall, the results indicate that cultivars for which IEC increased after harvest had reduced flesh firmness and TA after storage.

Transcriptional Activator Elements for Curtovirus C1 Expression Reside in the 3' Coding Region of ORF C1

  • Hur, Jingyung;Buckley, Kenneth J.;Lee, Sukchan;Davis, Keith R.
    • Molecules and Cells
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    • v.23 no.1
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    • pp.80-87
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    • 2007
  • Beet curly top virus (BCTV) and Beet severe curly top virus (BSCTV), members of curtoviruses, encode seven open reading frames (ORFs) within a ~3 kb genome. One of these viral ORFs, C1, is known to play an important role in the early stage of viral infection in plants during initiation of viral DNA replication. We used promoter:: reporter (${\beta}$-glucuronidase) gene fusions in transgenic Arabidopsis to identify the putative promoter region of BCTV ORF C1. Unlike other geminiviruses, the intergenic region of BCTV was not sufficient to promote C1 expression in transgenic plants. When sequences extending into the coding region of C1 were tested, strong expression of the reporter protein was observed in vascular tissues of transgenic plants. This expression was not dependent on the presence of the intergenic regions or proximal 5' portions of the C1 coding region. Transgenic plants expressing a reporter gene under control of the putative complete C1 promoter were inoculated with virus to determine if any viral transcript affected C1 expression. Virus inoculated plants did not show any altered pattern or change in of reporter gene expression level. These results suggest that (1) important transcriptional activator elements for C1 expression reside in the 3' portion of C1 coding area itself, (2) C1 protein does not auto-regulate its own expression and (3) C1 expression of two curtoviruses is controlled differently compared to other geminiviruses.

Analysis of Organic Molecular Markers in Atmospheric Fine Particulate Matter: Understanding the Impact of "Unknown" Point Sources on Chemical Mass Balance Models

  • Bae, Min-Suk;Schauer, James J.
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.3
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    • pp.219-236
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    • 2009
  • Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

The Role of Stem Cells and Gap Junctional Intercellular Communication in Carcinogenesis

  • Trosko, James E.
    • BMB Reports
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    • v.36 no.1
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    • pp.43-48
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    • 2003
  • Understanding the process of carcinogenesis will involve both the accumulation of many scientific facts derived from molecular, biochemical, cellular, physiological, whole animal experiments and epidemiological studies, as well as from conceptual understanding as to how to order and integrate those facts. From decades of cancer research, a number of the "hallmarks of cancer" have been identified, as well as their attendant concepts, including oncogenes, tumor suppressor genes, cell cycle biochemistry, hypotheses of metastasis, angiogenesis, etc. While all these "hallmarks" are well known, two important concepts, with their associated scientific observations, have been generally ignored by many in the cancer research field. The objective of the short review is to highlight the concept of the role of human adult pluri-potent stem cells as "target cells" for the carcinogenic process and the concept of the role of gap junctional intercellular communication in the multi-stage, multi-mechanism process of carcinogenesis. With these two concepts, an attempt has been made to integrate the other well-known concepts, such as the multi-stage, multi-mechanisn or the "initiation/promotion/progression" hypothesis; the stem cell theory of carcinogenesis; the oncogene/tumor suppression theory and the mutation/epigenetic theories of carcinogenesis. This new "integrative" theory tries to explain the well-known "hallmarks" of cancers, including the observation that cancer cells lack either heterologous or homologous gap junctional intercellular communication whereas normal human adult stem cells do not have expressed or functional gap junctional intercellular communication. On the other hand, their normal differentiated, non-stem cell derivatives do express connexins and express gap junctional intercellular communication during their differentiation. Examination of the roles of chemical tumor promoters, oncogenes, connexin knock-out mice and roles of genetically-engineered tumor and normal cells with connexin and anti-sense connexin genes, respectively, seems to provide evidence which is consistent with the roles of both stem cells and gap junctional communication playing a major role in carcinogenesis. The integrative hypothesis provides new strategies for chemoprevention and chemotherapy which focuses on modulating connexin gene expression or gap junctional intercellular communication in the premalignant and malignant cells, respectively.

Methods for sampling and analysis of marine microalgae in ship ballast tanks: a case study from Tampa Bay, Florida, USA

  • Garrett, Matthew J.;Wolny, Jennifer L.;Williams, B. James;Dirks, Michael D.;Brame, Julie A.;Richardson, R. William
    • ALGAE
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    • v.26 no.2
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    • pp.181-192
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    • 2011
  • Ballasting and deballasting of shipping vessels in foreign ports have been reported worldwide as a vector of introduction of non-native aquatic plants and animals. Recently, attention has turned to ballast water as a factor in the global increase of harmful algal blooms (HABs). Many species of microalgae, including harmful dinoflagellate species, can remain viable for months in dormant benthic stages (cysts) in ballast sediments. Over a period of four years, we surveyed ballast water and sediment of ships docked in two ports of Tampa Bay, Florida, USA. Sampling conditions encountered while sampling ballast water and sediments were vastly different between vessels. Since no single sample collection protocol could be applied, existing methods for sampling ballast were modified and new methods created to reduce time and labor necessary for the collection of high-quality, qualitative samples. Five methods were refined or developed, including one that allowed for a directed intake of water and sediments. From 63 samples, 1,633 dinoflagellate cysts and cyst-like cells were recovered. A native, cyst-forming, harmful dinoflagellate, Alexandrium balechii (Steidinger) F. J. R. Taylor, was collected, isolated, and cultured from the same vessel six months apart, indicating that ships exchanging ballast water in Tampa Bay have the potential to transport HAB species to other ports with similar ecologies, exposing them to non-native, potentially toxic blooms.