Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-28374638

RESUMO

Optimising supply chain management can help to reduce food waste. This paper describes how intelligent packaging can be used to reduce food waste when used in supply chain management based on quality-controlled logistics (QCL). Intelligent packaging senses compounds in the package that correlate with the critical quality attribute of a food product. The information on the quality of each individual packaged food item that is provided by the intelligent packaging can be used for QCL. In a conceptual approach it is explained that monitoring food quality by intelligent packaging sensors makes it possible to obtain information about the variation in the quality of foods and to use a dynamic expiration date (IP-DED) on a food package. The conceptual approach is supported by quantitative data from simulations on the effect of using the information of intelligent packaging in supply chain management with the goal to reduce food waste. This simulation shows that by using the information on the quality of products that is provided by intelligent packaging, QCL can substantially reduce food waste. When QCL is combined with dynamic pricing based on the predicted expiry dates, a further waste reduction is envisaged.


Assuntos
Embalagem de Alimentos/métodos , Qualidade dos Alimentos , Abastecimento de Alimentos , Conservação de Alimentos , Humanos
2.
Epidemiol Infect ; 144(5): 1084-95, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26415763

RESUMO

Decision making on hazard surveillance in livestock product chains is a multi-hazard, multi-stakeholder, and multi-criteria process that includes a variety of decision alternatives. The multi-hazard aspect means that the allocation of the scarce resource for surveillance should be optimized from the point of view of a surveillance portfolio (SP) rather than a single hazard. In this paper, we present a novel conceptual approach for economic optimization of a SP to address the resource allocation problem for a surveillance organization from a theoretical perspective. This approach uses multi-criteria techniques to evaluate the performances of different settings of a SP, taking cost-benefit aspects of surveillance and stakeholders' preferences into account. The credibility of the approach has also been checked for conceptual validity, data needs and operational validity; the application potentials of the approach are also discussed.


Assuntos
Doenças dos Animais/economia , Doenças dos Animais/epidemiologia , Gado , Vigilância da População/métodos , Animais , Técnicas de Apoio para a Decisão , Modelos Econômicos , Alocação de Recursos , Medição de Risco/economia
3.
Transbound Emerg Dis ; 63(3): 296-313, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25213149

RESUMO

Classical swine fever (CSF) is a highly contagious pig disease that causes economic losses and impaired animal welfare. Improving the surveillance system for CSF can help to ensure early detection of the virus, thereby providing a better initial situation for controlling the disease. Economic analysis is required to compare the benefits of improved surveillance with the costs of implementing a more intensive system. This study presents a comprehensive economic analysis of CSF surveillance in the Netherlands, taking into account the specialized structure of Dutch pig production, differences in virulence of CSF strains and a complete list of possible surveillance activities. The starting point of the analysis is the current Dutch surveillance system (i.e. the default surveillance-setup scenario), including the surveillance activities 'daily clinical observation by the farmer', 'veterinarian inspection after a call', 'routine veterinarian inspection', 'pathology in AHS', 'PCR on tonsil in AHS', 'PCR on grouped animals in CVI' and 'confirmatory PCR by NVWA'. Alternative surveillance-setup scenarios were proposed by adding 'routine serology in slaughterhouses', 'routine serology on sow farms' and 'PCR on rendered animals'. The costs and benefits for applying the alternative surveillance-setup scenarios were evaluated by comparing the annual mitigated economic losses because of intensified CSF surveillance with the annual additional surveillance costs. The results of the cost-effectiveness analysis show that the alternative surveillance-setup scenarios with 'PCR on rendered animals' are effective for the moderately virulent CSF strain, whereas the scenarios with 'routine serology in slaughterhouses' or 'routine serology on sow farms' are effective for the low virulent strain. Moreover, the current CSF surveillance system in the Netherlands is cost-effective for both moderately virulent and low virulent CSF strains. The results of the cost-benefit analysis for the moderately virulent CSF strain indicate that the current surveillance system in the Netherlands is adequate. From an economic perspective, there is little to be gained from intensifying surveillance.


Assuntos
Vírus da Febre Suína Clássica/patogenicidade , Peste Suína Clássica/economia , Monitoramento Epidemiológico/veterinária , Animais , Peste Suína Clássica/epidemiologia , Peste Suína Clássica/virologia , Vírus da Febre Suína Clássica/genética , Análise Custo-Benefício , Feminino , Modelos Teóricos , Países Baixos/epidemiologia , Suínos , Virulência
4.
Prev Vet Med ; 114(3-4): 188-200, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24630402

RESUMO

Economic analysis of hazard surveillance in livestock production chains is essential for surveillance organizations (such as food safety authorities) when making scientifically based decisions on optimization of resource allocation. To enable this, quantitative decision support tools are required at two levels of analysis: (1) single-hazard surveillance system and (2) surveillance portfolio. This paper addresses the first level by presenting a conceptual approach for the economic analysis of single-hazard surveillance systems. The concept includes objective and subjective aspects of single-hazard surveillance system analysis: (1) a simulation part to derive an efficient set of surveillance setups based on the technical surveillance performance parameters (TSPPs) and the corresponding surveillance costs, i.e., objective analysis, and (2) a multi-criteria decision making model to evaluate the impacts of the hazard surveillance, i.e., subjective analysis. The conceptual approach was checked for (1) conceptual validity and (2) data validity. Issues regarding the practical use of the approach, particularly the data requirement, were discussed. We concluded that the conceptual approach is scientifically credible for economic analysis of single-hazard surveillance systems and that the practicability of the approach depends on data availability.


Assuntos
Agricultura , Doenças dos Animais/economia , Doenças dos Animais/epidemiologia , Gado/fisiologia , Modelos Econômicos , Animais , Vigilância da População , Medição de Risco , Medicina Veterinária/economia
5.
J Dairy Sci ; 97(4): 1893-908, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24508435

RESUMO

Production of many consumer products results in byproducts that contain a considerably large part of nutrients originating from input materials. High production volumes, environmental impact, and nutritional content of byproducts make them an important subject for careful valorization. Valorization allows us to explore the possibility of reusing nutrients in the production of main products, and thus highlights the potential gains that can be achieved. The main aim of this study was to evaluate the added value of cheese whey valorization, and to determine the effect of integral valorization of main products and byproducts on the profit of a dairy producer. Several scenarios and cases were implemented and analyzed using a decision support tool, the integral dairy valorization model. Data originated from the international dairy processor FrieslandCampina (Amersfoort, the Netherlands). The outcomes of scenarios were analyzed with regard to profit and shifts in the production of nonwhey end products, and were validated by company experts. Modeling results showed that the valorization of byproducts is very profitable (24.3% more profit). Furthermore, additional profit can be achieved when 2 valorization processes (main products and byproducts) are integrated. This effect is, however, considerably affected by current capacity and market demand limitations. Significant benefits can be created if demand of whey-based products is increased by 25%.


Assuntos
Queijo/economia , Indústria de Laticínios/economia , Leite/economia , Animais , Bovinos , Técnicas de Apoio para a Decisão , Modelos Teóricos , Países Baixos
6.
J Dairy Sci ; 96(2): 761-79, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23200469

RESUMO

Dairy processors face numerous challenges resulting from both unsteady dairy markets and some specific characteristics of dairy supply chains. To maintain a competitive position on the market, companies must look beyond standard solutions currently used in practice. This paper presents a comprehensive dairy valorization model that serves as a decision support tool for mid-term allocation of raw milk to end products and production planning. The developed model was used to identify the optimal product portfolio composition. The model allocates raw milk to the most profitable dairy products while accounting for important constraints (i.e., recipes, composition variations, dairy production interdependencies, seasonality, demand, supply, capacities, and transportation flows). The inclusion of all relevant constraints and the ease of understanding dairy production dynamics make the model comprehensive. The developed model was tested at the international dairy processor FrieslandCampina (Amersfoort, the Netherlands). The structure of the model and its output were discussed in multiple sessions with and approved by relevant FrieslandCampina employees. The elements included in the model were considered necessary to optimally valorize raw milk. To illustrate the comprehensiveness and functionality of the model, we analyzed the effect of seasonality on milk valorization. A large difference in profit and a shift in the allocation of milk showed that seasonality has a considerable impact on the valorization of raw milk.


Assuntos
Indústria de Laticínios/organização & administração , Animais , Bovinos , Laticínios/economia , Laticínios/provisão & distribuição , Indústria de Laticínios/economia , Indústria de Laticínios/métodos , Leite/economia , Leite/provisão & distribuição , Modelos Teóricos , Países Baixos , Estações do Ano
7.
Magn Reson Med ; 46(5): 932-8, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11675645

RESUMO

The signal-enhancing characteristics of a new monodisperse monogadolinated macromolecular MR contrast medium (P792) were evaluated for magnetic resonance angiography (MRA) of the coronary arteries. A total of 15 cardiac examinations were performed in pigs at 1.5 T using a 3D gradient-echo sequence. Images were acquired during breath-hold before and up to 35 min after IV injection of Gd-DTPA (0.3 mmol Gd/kg), Gd-BOPTA (0.2 mmol Gd/kg), and P792 (13 micromol Gd/kg). An increase in the signal-to-noise ratio (SNR) of 97% +/- 17%, 108% +/- 37%, and 109% +/- 31% in coronary arteries and of 82% +/- 19%, 82% +/- 24%, and 28% +/- 18% in myocardium, respectively, was measured during the first postcontrast acquisition. The blood-to-myocardium signal-difference-to-noise ratio (SDNR) was significantly higher for P792 than for the other Gd compounds (P <.05) for up to 15 min after injection. Qualitative assessment showed that visualization of the coronary arteries and their branches was significantly better for P792 compared to the low-molecular Gd compounds (P <.05). The blood pool contrast medium P792 is well suited for MRA of the coronary arteries.


Assuntos
Vasos Coronários/anatomia & histologia , Compostos Heterocíclicos , Angiografia por Ressonância Magnética/métodos , Meglumina/análogos & derivados , Compostos Organometálicos , Animais , Meios de Contraste , Gadolínio , Gadolínio DTPA , Imageamento Tridimensional , Suínos , Porco Miniatura
9.
Proc Natl Acad Sci U S A ; 97(17): 9498-503, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10920185

RESUMO

c-Myc plays a vital role in cell-cycle progression. Deregulated expression of c-Myc can overcome cell-cycle arrest in order to promote cellular proliferation. Transforming growth factor beta (TGFbeta) treatment of immortalized human keratinocyte cells inhibits cell-cycle progression and is characterized by down-regulation of c-Myc followed by up-regulation of p21(CIP1). A direct role of c-Myc in this pathway was demonstrated by the observation that ectopic expression of c-Myc overcame the cell-cycle block induced by TGFbeta treatment. The induction of p21(CIP1) transcription by TGFbeta was blocked in human keratinocyte cells stably expressing c-Myc. Furthermore, overexpression of c-Myc in NIH 3T3 cells repressed the basal levels of p21(CIP1) mRNA. Repression of p21(CIP1) transcription by c-Myc occurred at the promoter level in a region near the start site of transcriptional initiation and was independent of histone deacetylase activity. These data suggest that the down-regulation of c-Myc after TGFbeta signaling is important for subsequent regulation of p21(CIP1) and cell-cycle inhibition. Thus, repression of the cell-cycle inhibitory gene p21(CIP1) plays a role in c-Myc-dependent cell-cycle progression.


Assuntos
Ciclo Celular/efeitos dos fármacos , Ciclinas/genética , Inativação Gênica , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fator de Crescimento Transformador beta/antagonistas & inibidores , Fator de Crescimento Transformador beta/farmacologia , Células 3T3 , Animais , Linhagem Celular , Inibidor de Quinase Dependente de Ciclina p21 , Regulação para Baixo/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases , Histona Desacetilases/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Camundongos , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas c-myc/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Elementos de Resposta/genética , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética , Transfecção , Regulação para Cima/efeitos dos fármacos
10.
Mol Cell Biol ; 20(14): 5276-84, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10866684

RESUMO

Somatic mutations at Thr-58 of c-Myc have been detected in Burkitt's lymphoma (BL) tumors and have been shown to affect the transforming potential of the Myc oncoprotein. In addition, the N-terminal domain of c-Myc has been shown to interact with microtubules in vivo, and the binding of c-Myc to alpha-tubulin was localized to amino acids 48 to 135 within the c-Myc protein. We demonstrate that c-Myc proteins harboring a naturally occurring mutation at Thr-58 from BL cell lines have increased stability and are constitutively hyperphosphorylated, which disrupts the in vivo interaction of c-Myc with alpha-tubulin. In addition, we show that wild-type c-Myc-alpha-tubulin interactions are also disrupted during a transient mitosis-specific hyperphosphorylation of c-Myc, which resembles the constitutive hyperphosphorylation pattern of Thr-58 in BL cells.


Assuntos
Linfoma de Burkitt/genética , Mitose , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Tubulina (Proteína)/metabolismo , Substituição de Aminoácidos , Linfoma de Burkitt/patologia , Linhagem Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Microtúbulos/metabolismo , Mutação , Mapeamento de Peptídeos , Fosfoproteínas/metabolismo , Fosforilação
11.
Mol Cell Biol ; 20(12): 4309-19, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10825194

RESUMO

We have assayed the oncogenic, proliferative, and apoptotic activities of the frequent mutations that occur in the c-myc gene in Burkitt's lymphomas. Some alleles have a modest (50 to 60%) increase in transforming activity; however, the most frequent Burkitt's lymphoma allele (T58I) had an unexpected substantial decrease in transforming activity (85%). All alleles restored the proliferation function of c-Myc in cells that grow slowly due to a c-myc knockout. There was discordance for some alleles between apoptotic and oncogenic activities, but only the T58A allele had elevated transforming activity with a concomitant reduced apoptotic potential. We discovered a novel missense mutation, MycS71F, that had a very low apoptotic activity compared to wild-type Myc, yet this mutation has never been found in lymphomas, suggesting that there is no strong selection for antiapoptotic c-Myc alleles. MycS71F also induced very low levels of cytochrome c release from mitochondria, suggesting a mechanism of action for this mutation. Phosphopeptide mapping provided a biochemical basis for the dramatically different biological activities of the transformation-defective T58I and transformation-enhanced T58A c-Myc alleles. Furthermore, the antiapoptotic survival factor insulin-like growth factor 1 was found to suppress phosphorylation of T58, suggesting that the c-Myc transactivation domain is a direct target of survival signals.


Assuntos
Apoptose/genética , Regulação da Expressão Gênica , Genes myc , Mutação de Sentido Incorreto , Animais , Linfoma de Burkitt/genética , Linfoma de Burkitt/patologia , Divisão Celular/genética , Linhagem Celular , Humanos , Transfecção
12.
Oncogene ; 18(19): 2925-33, 1999 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-10378689

RESUMO

Myc is an important regulator of many cellular processes, including growth promotion, differentiation, and apoptosis. The mechanisms underlying Myc biological activity, however, remain elusive. For many years, research in the field has focused on the idea of Myc as a transactivator of gene expression. More recently, alternative mechanisms of Myc function have been proposed, including gene repression. In this review we present several lines of evidence to support a connection between Myc-mediated transformation and transcriptional repression.


Assuntos
Transformação Celular Neoplásica , Proteínas Proto-Oncogênicas c-myc/fisiologia , Animais , Regulação da Expressão Gênica , Humanos , Modelos Genéticos
13.
Genes Dev ; 12(24): 3803-8, 1998 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9869633

RESUMO

Transcriptional activation by c-Myc through specific E box elements is thought to be essential for its biological role. However, c-MycS is unable to activate transcription through these elements and yet retains the ability to stimulate proliferation, induce anchorage-independent growth, and induce apoptosis. In addition, c-MycS retains the ability to repress transcription of several specific promoters. Furthermore, c-MycS can rescue the c-myc null phenotype in fibroblasts with homozygous deletion of c-myc. Taken together, our data argue against the paradigm that all of the biological functions of c-Myc are mediated by transcriptional activation of specific target genes through E box elements.


Assuntos
Apoptose , Divisão Celular , Regulação da Expressão Gênica , Isoformas de Proteínas/fisiologia , Proteínas Proto-Oncogênicas c-myc/fisiologia , Proteínas de Saccharomyces cerevisiae , Células 3T3 , Animais , Linhagem Celular , Transformação Celular Neoplásica , Elementos Facilitadores Genéticos/genética , Genes myc , Genes p53 , Peptídeos e Proteínas de Sinalização Intracelular , Glicoproteínas de Membrana/genética , Camundongos , Ornitina Descarboxilase/genética , Fenótipo , Isoformas de Proteínas/genética , Precursores de Proteínas/genética , Proteínas/genética , Ratos , Proteínas Repressoras/genética , Proteínas Repressoras/fisiologia , Elementos de Resposta/genética , Deleção de Sequência , Timosina/análogos & derivados , Timosina/genética , Ativação Transcricional , Transfecção , Proteínas GADD45
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...