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1.

Purpose  

A renewable thermoplastic called Novatein Thermoplastic Protein (NTP) has been developed from blood meal—a low-value by-product of the meat processing industry. The aim of this research was to develop a non-renewable energy and greenhouse gas emission eco-profile for cradle to gate production of NTP. Environmental impacts of supplying blood meal as a raw material were investigated using different allocation methods for farming and blood meal production. These included mass, economic, treating low-value by-products as waste and system expansion by substitution. In part 2, the entire system will be analysed on a cradle to gate basis and include the production of thermoplastic (NTP).  相似文献   

2.

Purpose  

This study’s aim was to understand the effect of mine characteristics on cradle-to-gate life cycle impacts of surface coal mining in the USA. Five bituminous coal strip mines were used as case studies. The study assessed the life cycle water use, land use, energy use, abiotic resource depletion, and climate change impacts.  相似文献   

3.

Purpose

Biopolymers are considered to be environmentally friendlier than petroleum-based polymers, but little is known about their environmental performance against petroleum-based products. This paper presents the results of a life cycle assessment (LCA) of two prototype biocomposite formulations produced by extrusion of wood fibre with either polylactic acid (PLA) or a blend of PLA and locally produced thermoplastic starch (TPS).

Methods

The study followed the LCA methodology outlined in the two standards set out by the International Organization for Standardization (ISO): ISO 14040 and ISO 14044 of 2006. A life cycle inventory (LCI) for the biocomposite formulations was developed, and a contribution analysis was performed to identify the significant inputs. Environmental performances of the two formulations were then compared with each other and polypropylene (PP), a petroleum-based polymer. The US Environmental Protection Agency’s impact assessment method, “TRACI: The Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts”, was combined with Cumulative Energy Demand (a European method) in order to characterize the inventory flows. Environmental impact categories chosen for the analysis were the following: global warming, stratospheric ozone depletion, acidification of land and water, eutrophication, smog, human health (respiratory, carcinogenic, and non-carcinogenic) effects and ecotoxicity.

Results and discussion

We found that PLA is the significant input which contributes mostly to fossil fuel consumption, acidification and respiratory and smog effects. Impacts from PLA transport from the faraway source significantly added more burden to its contributions. TPS causes less environmental burden compared to PLA; the environmental performance of the biocomposite improved when a blend of PLA and TPS is used in formulating the biocomposite. The two formulations performed better than PP in all the environmental impact categories except eutrophication effects, which is important on a regional basis.

Conclusions

The following conclusions were drawn from this study:
  • PLA is the environmentally significant input among the three raw materials.
  • TPS causes less environmental burden than PLA. Environmental performance of the biocomposite improves in the life cycle energy consumption, fossil energy use, ozone depletion and non-carcinogenic impact categories when a blend of PLA and TPS is used.
  • The biocomposite can outperform PP in all the impact categories except eutrophication effects if manufactured using hydroelectricity.
The biopolymer could be a potential alternative to PP as it could cause less of a burden to the environment on a cradle-to-gate basis. Environmental impacts at the complete life cycle levels should be looked into in order to fully understand its potential.  相似文献   

4.

Purpose

Part 1 of this research investigated environmental footprint for the cradle-to-grave of a linear metre I-beam made from traditional and alternative materials which are stainless steel (316) and glass reinforced plastics (GRP). Results revealed that GRP generally produced less environmental footprint than stainless steel. The main contribution found in the cradle-to-gate caused by raw materials (90 %) and associated transportation (10 %). Certain impact categories of GRP were either equalled or higher than stainless steel I-beam including the climate change impact category. Therefore, part 2 of this research further investigates the ecological and economic hot spots of the cradle-to-gate of GRP I-beam and alternative supply chain scenarios. The potential carbon tax was also estimated under two different situations.

Methods

GRP and stainless steel (316) are used to assess the environmental footprint and the economic impact of 6,098 m I-beams as a production volume in practice. The World ReCiPe midpoint and endpoint methods generated the life cycle inventory, characteristic and single score results for the environmental footprint. The economic impact estimated based on a simple cost calculation associated with the cradle-to-gate including material, production and transportation costs. The ecological and economic hot spots were identified and formed 12 supply chain scenarios.

Results and discussion

Both identified hot spots came from raw materials that used in large quantities, consumed higher electricity and delivered by road and water transportation over long travel distances. The climate change impact category and the potential carbon tax values are improved under the scenarios that use a supplier from countries that generate electricity from less coal-based energy source and involve less transportation in delivering the raw materials.

Conclusions

Win–win and trade-off scenarios were revealed when comparing both impacts. The former scenario reduces material costs, the travel distances and using lower freight rate transportation that consumes less fuel such as shipping. The latter scenarios are often occurred by either attempting to reduce the environmental footprint from using less transportation but the raw material costs are suffered. Manufacturers may select the scenario based on their production constrains. Cradle-to-grave was discussed and shown the benefits in including steel recycling into the assessment which can equate the potential carbon tax of the stainless steel with some GRP I-beam scenarios. Future work can be enhanced by considering other factors in the practice of manufacturing system such as insurance cost and lead time.  相似文献   

5.

Methods  

The main objective of this study is to combine the environmental evaluation of a basic wood box used to store wine bottles by means of the integration of two environmental methodologies: a quantitative methodology known as life cycle assessment (LCA) and a qualitative methodology which is useful in integrating environmental aspects into design, that is, the design for the environment (DfE). The LCA study covers the life cycle of wood box production from a cradle-to-gate perspective. A wood processing company located in Galicia (NW, Spain) was analysed in detail, dividing the process chain into five stages: cogeneration unit, material assembling, painting, packaging and distribution to clients.  相似文献   

6.

Purpose

I-beams for outdoor structures are traditionally made from conventional materials such as stainless steel due to its high strength and corrosive resistant properties. Alternatively, the I-beam can also be made from composite materials such as glass-reinforced plastics (GRP), which provide similar properties under a lighter weight and a lower cost condition. Nonetheless, their environmental footprint performance depends largely on activities involved during their life cycle. Therefore, the findings are presented in two parts: Part 1 and 2. This paper is about Part 1, which presents the environmental footprint for the cradle-to-grave of one linear metre I-beam that is made from two materials namely stainless steel (316) and GRP. Part 2, which will be submitted as a separate paper, has specifically analysed their environmental and economic impacts for the different cradle-to-gate scenarios and the potential carbon tax.

Materials and methods

Materials that were used to compare the environmental footprint of an I-beam are GRP and stainless steel (316). Their cradle-to-grave activities included raw material extraction, supplier transportation, manufacturing process, distribution, disposal transportation and process. Input data were based on data provided by a composites company in Australia, the Ecoinvent 2.2 and Australian data 2007 databases. The World ReCiPe midpoint and endpoint methods were used to assess the environmental footprint.

Results and discussion

The environmental footprint results for the cradle-to-grave of the I-beams are presented as a contribution percentage of the single score unit in the total and damage category levels which produced by the endpoint method. The characteristic and normalisation results were also generated for all impact categories by the midpoint method.

Conclusions

Overall, the cradle-to-grave results show that the composite I-beam produces 20 % less environmental footprint than that of the stainless steel I-beam. The human health damage category is affected the most due to the main contribution from the material stage. The cradle-to-gate results are contributed by 90 % from raw material extraction, 7 % from the manufacturing process and 3 % from the supplier transportation. In terms of the characteristic results, the composite I-beam produces less environmental impact in most of the impact categories except for the climate change, photochemical oxidant formation, terrestrial acidification, marine eutrophication, natural land transformation and fossil depletion. Therefore, the influential parameters of these impact categories are investigated further in Part 2 where the environmental footprint and economic impact are estimated for different cradle-to-gate scenarios of the I-beams.  相似文献   

7.

Background, aim, and scope  

North American pulp and paper mills are facing tremendous challenges, which may necessitate major mill modernizations. An example is process modification to reduce dependency on purchased power, which is an expensive resource. Such modifications may have environmental implications at the mills’ sites, on their product life cycle, and on other interconnected systems, and therefore, systematic tools such as life cycle assessment (LCA) need to be applied. Different LCA system boundary approaches can be used for such process design applications, and these approaches need to be compared to determine their respective benefits and limitations in this context. This study compares setting the system boundary according to a cradle-to-gate approach [attributional LCA (ALCA)] and a system expansion [consequential LCA (CLCA)] approach using a case study, which deals with implementing cogeneration and increased de-inked pulp production at an integrated newsprint mill.  相似文献   

8.

Goal, Scope and Background  

District heating, the utilization of centrally produced heat for space heating and domestic hot water generation, has the potential to contribute to the eco-efficient use of energy resources in the parts of the world where space heating is needed. In literature, environmental studies on district heating mainly consider the emissions from heat generation; the environmental impact from the distribution system is seldom discussed. This paper presents a life cycle assessment of the production of district heating pipes, based on a cradle-to-gate life cycle inventory commissioned by the Swedish District Heating Association. No external review has been performed but a reference group of district heating experts familiar with the practice was involved in the choice of cases as well as in reviewing parts of the study.  相似文献   

9.

Objective:

The aim of this study was to compare postprandial lipemia, oxidative stress, antioxidant activity, and insulinemia between a three and six isocaloric high‐carbohydrate meal frequency pattern in obese women.

Design and Methods:

In a counterbalanced order, eight obese women completed two, 12‐h conditions in which they consumed 1,500 calories (14% protein, 21% fat, and 65% carbohydrate) either as three 500 calorie liquid meals every 4‐h or six 250 calorie liquid meals every 2‐h. Blood samples were taken every 30 min and analyzed for triacylglycerol (TAG), total cholesterol, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, oxidized low‐density lipoprotein cholesterol, myeloperoxidase, paraoxonase‐1 activity, and insulin.

Results:

The TAG incremental area under the curve (iAUC) during the three meal condition (321 ± 129 mg/dl·12 h) was significantly lower (P = 0.04) compared with the six meal condition (481 ± 155 mg/dl·12 h). The insulin iAUC during the three meal condition (5,549 ± 1,007 pmol/l.12 h) was significantly higher (P = 0.05) compared with the six meal condition (4,230 ± 757 pmol/l.12 h). Meal frequency had no influence on the other biochemical variables.

Conclusions:

Collectively, a three and six isocaloric high‐carbohydrate meal frequency pattern differentially alters postprandial TAG and insulin concentrations but has no effect on postprandial cholesterol, oxidative stress, or antioxidant activity in obese women.  相似文献   

10.

Background

In this study we compared the utility of two molecular biology techniques, cloning of the mitochondrial 12S ribosomal RNA gene and hydrolysis probe-based qPCR, to identify blood meal sources of sylvatic Chagas disease insect vectors collected with live-bait mouse traps (also known as Noireau traps). Fourteen T. guasayana were collected from six georeferenced trap locations in the Andean highlands of the department of Chuquisaca, Bolivia.

Methodology/Principal Findings

We detected four blood meals sources with the cloning assay: seven samples were positive for human (Homo sapiens), five for chicken (Gallus gallus) and unicolored blackbird (Agelasticus cyanopus), and one for opossum (Monodelphis domestica). Using the qPCR assay we detected chicken (13 vectors), and human (14 vectors) blood meals as well as an additional blood meal source, Canis sp. (4 vectors).

Conclusions/Significance

We show that cloning of 12S PCR products, which avoids bias associated with developing primers based on a priori knowledge, detected blood meal sources not previously considered and that species-specific qPCR is more sensitive. All samples identified as positive for a specific blood meal source by the cloning assay were also positive by qPCR. However, not all samples positive by qPCR were positive by cloning. We show the power of combining the cloning assay with the highly sensitive hydrolysis probe-based qPCR assay provides a more complete picture of blood meal sources for insect disease vectors.  相似文献   

11.

Background

During their blood meal, ticks secrete a wide variety of proteins that can interfere with their host''s defense mechanisms. Among these proteins, lipocalins play a major role in the modulation of the inflammatory response.

Methodology/Principal Findings

We previously identified 14 new lipocalin genes in the tick Ixodes ricinus. One of them codes for a protein that specifically binds leukotriene B4 with a very high affinity (Kd: ±1 nM), similar to that of the neutrophil transmembrane receptor BLT1. By in silico approaches, we modeled the 3D structure of the protein and the binding of LTB4 into the ligand pocket. This protein, called Ir-LBP, inhibits neutrophil chemotaxis in vitro and delays LTB4-induced apoptosis. Ir-LBP also inhibits the host inflammatory response in vivo by decreasing the number and activation of neutrophils located at the tick bite site. Thus, Ir-LBP participates in the tick''s ability to interfere with proper neutrophil function in inflammation.

Conclusions/Significance

These elements suggest that Ir-LBP is a “scavenger” of LTB4, which, in combination with other factors, such as histamine-binding proteins or proteins inhibiting the classical or alternative complement pathways, permits the tick to properly manage its blood meal. Moreover, with regard to its properties, Ir-LBP could possibly be used as a therapeutic tool for illnesses associated with an increased LTB4 production.  相似文献   

12.

Background

Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama.

Methodology/Principal Findings

R. pallescens vectors (N = 643) were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3%) vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3%) dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas) were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as rmax, the maximum intrinsic rate of population increase), and habitat type (forest fragments and peridomiciliary sites) were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of rmax were positively associated with higher vector infection rate at a site.

Conclusions/Significance

In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially by changing host community structure to favor hosts that are short-lived with high reproductive rates. Study results apply to potential environmental management strategies for Chagas disease.  相似文献   

13.

Background

Triatoma dimidiata, currently the major Central American vector of Trypanosoma cruzi, the parasite that causes Chagas disease, inhabits caves throughout the region. This research investigates the possibility that cave dwelling T. dimidiata might transmit the parasite to humans and links the blood meal sources of cave vectors to cultural practices that differ among locations.

Methodology/Principal Findings

We determined the blood meal sources of twenty-four T. dimidiata collected from two locations in Guatemala and one in Belize where human interactions with the caves differ. Blood meal sources were determined by cloning and sequencing PCR products amplified from DNA extracted from the vector abdomen using primers specific for the vertebrate 12S mitochondrial gene. The blood meal sources were inferred by ≥99% identity with published sequences. We found 70% of cave-collected T. dimidiata positive for human DNA. The vectors had fed on 10 additional vertebrates with a variety of relationships to humans, including companion animal (dog), food animals (pig, sheep/goat), wild animals (duck, two bat, two opossum species) and commensal animals (mouse, rat). Vectors from all locations fed on humans and commensal animals. The blood meal sources differ among locations, as well as the likelihood of feeding on dog and food animals. Vectors from one location were tested for T. cruzi infection, and 30% (3/10) tested positive, including two positive for human blood meals.

Conclusions/Significance

Cave dwelling Chagas disease vectors feed on humans and commensal animals as well as dog, food animals and wild animals. Blood meal sources were related to human uses of the caves. We caution that just as T. dimidiata in caves may pose an epidemiological risk, there may be other situations where risk is thought to be minimal, but is not.  相似文献   

14.

Purpose  

As liquid crystal display (LCD) flat-screen televisions increase in popularity, their potential contribution to global warming has received wide attention. This study presents global warming impacts resulting from the life cycle assessment (LCA) of LCD flat-screen televisions for key global warming contributors from the “cradle-to-gate” and use stages of the product’s life cycle. The emissions from nitrogen trifluoride (NF3), a greenhouse gas with a global warming potential (GWP) 17,000 times more potent than carbon dioxide (CO2), are not monitored in the Kyoto Protocol. Emissions in the cradle-to-gate and use stages were modeled in this study according to their GWP (kg CO2 equivalent), focusing and analyzing the most significant source of NF3 emissions.  相似文献   

15.
16.
Zhou G  Isoe J  Day WA  Miesfeld RL 《PloS one》2011,6(3):e18150

Background

One of the early events in midgut epithelial cells of Aedes aegypti mosquitoes is the dynamic reorganization of rough endoplasmic reticulum (RER) whorl structures coincident with the onset of blood meal digestion. Based on our previous studies showing that feeding on an amino acid meal induces TOR signaling in Ae. aegypti, we used proteomics and RNAi to functionally identify midgut epithelial cell proteins that contribute to RER whorl formation.

Methodology/Principal Findings

Adult female Ae. aegypti mosquitoes were maintained on sugar alone (unfed), or fed an amino acid meal, and then midgut epithelial cells were analyzed by electron microscopy and protein biochemistry. The size and number of RER whorls in midgut epithelial cells were found to decrease significantly after feeding, and several KDEL-containing proteins were shown to have altered expression levels. LC-MS/MS mass spectrometry was used to analyze midgut microsomal proteins isolated from unfed and amino acid fed mosquitoes, and of the 127 proteins identified, 8 were chosen as candidate whorl forming proteins. Three candidate proteins were COPI coatomer subunits (alpha, beta, beta''), all of which appeared to be present at higher levels in microsomal fractions from unfed mosquitoes. Using RNAi to knockdown alpha-COPI expression, electron microscopy revealed that both the size and number of RER whorls were dramatically reduced in unfed mosquitoes, and moreover, that extended regions of swollen RER were prevalent in fed mosquitoes. Lastly, while a deficiency in alpha-COPI had no effect on early trypsin protein synthesis or secretion 3 hr post blood meal (PBM), expression of late phase proteases at 24 hr PBM was completely blocked.

Conclusions

alpha-COPI was found to be required for the formation of RER whorls in midgut epithelial cells of unfed Aa. aegypti mosquitoes, as well as for the expression of late phase midgut proteases.  相似文献   

17.
18.

Background  

Recent interest in the function of the nuclear lamina has been provoked by the discovery of lamin A/C mutations in the laminopathy diseases. However, it is not understood why mutations in lamin A give such a range of tissue-specific phenotypes. Part of the problem in rationalising genotype-phenotype correlations in the laminopathies is our lack of understanding of the function of normal and mutant lamin A. To investigate this we have used photobleaching in human cells to analyse the dynamics of wild-type and mutant lamin A protein at the nuclear periphery.  相似文献   

19.
Cellulose cassava bagasse nanofibrils (CBN) were directly extracted from a by-product of the cassava starch (CS) industry, viz. the cassava bagasse (CB). The morphological structure of the ensuing nanoparticles was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), presence of other components such as sugars by high performance liquid chromatography (HPLC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) experiments. The resulting nanofibrils display a relatively low crystallinity and were found to be around 2–11 nm thick and 360–1700 nm long. These nanofibrils were used as reinforcing nanoparticles in a thermoplastic cassava starch matrix plasticized using either glycerol or a mixture of glycerol/sorbitol (1:1) as plasticizer. Nanocomposite films were prepared by a melting process. The reinforcing effect of the filler evaluated by dynamical mechanical tests (DMA) and tensile tests was found to depend on the nature of the plasticizer employed. Thus, for the glycerol-plasticized matrix-based composites, it was limited especially due to additional plasticization by sugars originating from starch hydrolysis during the acid extraction. This effect was evidenced by the reduction of glass vitreous temperature of starch after the incorporation of nanofibrils in TPSG and by the increase of elongation at break in tensile test. On the other hand, for glycerol/sorbitol plasticized nanocomposites the transcrystallization of amylopectin in nanofibrils surface hindered good performances of CBN as reinforcing agent for thermoplastic cassava starch. The incorporation of cassava bagasse cellulose nanofibrils in the thermoplastic starch matrices has resulted in a decrease of its hydrophilic character especially for glycerol plasticized sample.  相似文献   

20.

Background  

The brain-derived protein S100B has been shown to be a useful marker of brain injury of different etiologies. Cognitive dysfunction after cardiac surgery using cardiopulmonary bypass has been reported to occur in up to 70% of patients. In this study we tried to evaluate S100B as a marker for cognitive dysfunction after coronary bypass surgery with cardiopulmonary bypass in a model where the inflow of S100B from shed mediastinal blood was corrected for.  相似文献   

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