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1.
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The present study aimed at assessing the annual reproductive cycle of female Arabian carpetshark, Chiloscyllium arabicum from the Persian Gulf by a macroscopic and microscopic evaluation of the reproductive tract. The annual cycle of gonadal steroids [17β-estradiol (E2), progesterone (P4) and testosterone (T)] was also assessed in this shark. In total, 130 female C. arabicum were collected from the Bahrakan Creek (located northwest of the Persian Gulf) between January 2018 and March 2019. Females were oviparous with an external-type ovary and only one functional ovary. Five sexual maturity stages were recognized based on macroscopic and microscopic evaluation: Immature I (August–October), Immature II (November–January), Mature (February–March), Pregnant (April–May) and Spent (June–July). The structural changes in the oviducts, oviducal glands and uterus throughout the annual reproductive cycle were consistent with their roles in the egg movement, the egg capsule production and sperm storage. The plasma levels of the gonadal steroids were associated with morphological changes in the reproductive tract. E2 showed two detectable peaks during March (close to ovulation) and June (just before mating). P4 and T displayed a peak just before ovulation.  相似文献   

3.
The symbiotic association of corals and unicellular algae of the genus Symbiodinium in the southern Persian/Arabian Gulf (PAG) display an exceptional heat tolerance, enduring summer peak temperatures of up to 36 °C. As yet, it is not clear whether this resilience is related to the presence of specific symbiont types that are exclusively found in this region. Therefore, we used molecular markers to identify the symbiotic algae of three Porites species along >1000 km of coastline in the PAG and the Gulf of Oman and found that a recently described species, Symbiodinium thermophilum, is integral to coral survival in the southern PAG, the world''s hottest sea. Despite the geographic isolation of the PAG, we discovered that representatives of the S. thermophilum group can also be found in the adjacent Gulf of Oman providing a potential source of thermotolerant symbionts that might facilitate the adaptation of Indian Ocean populations to the higher water temperatures expected for the future. However, corals from the PAG associated with S. thermophilum show strong local adaptation not only to high temperatures but also to the exceptionally high salinity of their habitat. We show that their superior heat tolerance can be lost when these corals are exposed to reduced salinity levels common for oceanic environments elsewhere. Consequently, the salinity prevailing in most reefs outside the PAG might represent a distribution barrier for extreme temperature-tolerant coral/Symbiodinium associations from the PAG.  相似文献   

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Life cycle assessment framework in agriculture on the farm level   总被引:1,自引:0,他引:1  
Life Cycle Assessment (LCA) is a method that can be used to assess the environmental impact of agriculture, but impact categories and the functional unit of classical LCA’s must be adapted to the specific agricultural production process. Serving as an example, the framework of a LCA of 18 grassland dairy farms covering three farming intensity levels and carried out in the Allgäu region in southern Germany is presented. By focussing on the chosen impact categories and the respective, suitable functional units, the specific needs and backgrounds of conducting an agricultural LCA are discussed in general.  相似文献   

6.
Background, aims, and scope  Food is a vital human need that not only provides essential nutrition but is also a key part of our social life as well as being a valued sensory experience. However, food, or rather the production chain of food, from primary production (agriculture/aquaculture/fishing) to consumer and beyond, also results in some form of environmental impact, as does transport between steps. There are several life cycle assessment studies of food products, most of them analysing the impact of the food chain of single food items. Still, detailed studies of complete meals are less frequent in the literature. In the Swedish study presented in this article, the environmental impacts of two different chicken meals (homemade and semi-prepared) were analysed. The aim of the study was to gain knowledge of the environmental impact of integrated food chains and also to explore the effect of improvement measures in the post-farm systems. To this end, two chicken meals were chosen for analysis, with two scenarios for each meal; the first scenario reflects the present conditions of the food chain, and the second scenario incorporates a number of improvement actions in the stages after the farm. Materials and methods  Input data to the model were based mainly on previous life cycle assessment (LCA) studies of Swedish food products and studies on wastage and consumer transport. Food engineering data and information from producing companies were used for modelling the industries. The improvement scenario was constructed using insight from a preceding LCA study of a meatball meal (Sonesson et al., Ambio, 34:411–418, 2005a) along with goals set out by a Swedish agreement between representatives from national and regional government, food industry sectors and retailers. The impact assessment was conducted according to Lindfors et al. (Nordic guidelines on life cycle assessment, The Nordic Council of Ministers, Copenhagen, Denmark, 1995), and the following environmental effects were included: global warming potential, eutrophication potential, acidification potential, photochemical ozone creation potential, and use of primary energy carriers and secondary energy. Results  In terms of energy use, the largest part is used in the steps after the farm for both meal types. Hence, the changes made in the improvement scenario have a significant impact on the total energy use. For the homemade and semi-prepared meal, the reduction is 15% and 20% respectively, not only due to less consumer transport and packaging but also reduction in industry (semi-prepared). Agriculture is also a significant contributor to emissions of greenhouse gases and eutrophying emissions; for the homemade meal, around 40% of the greenhouse gases originate from agriculture, and for the semi-prepared meal, the figure is 50%. The improvement actions with the greatest reduction in greenhouse gases are, again, less consumer transport and, in the case of the semi-prepared meal, the reduction in energy use in industry. Regarding eutrophication, more than 90% of the emissions originate from agriculture. Hence, the only improvement action that has an effect here is the utilisation of raw material downstream in the production chain; a slight reduction in waste still gives a notable reduction in overall eutrophic emissions. Discussion  There are two significant areas of research to reduce the impact of meals that are not explored in this study: choice of meal components and production methods in agriculture. However, the aim with this study was to explore if there are further ways of reducing the impact without going into these very complex areas, and our conclusion is that there are effective ways in the post-farm chain to cut emissions that, together with choices of diet and agricultural research, can significantly reduce the impact of our food consumption. Conclusions  Actions in the post-farm chain that can significantly reduce the environmental impact of a meal are less food thrown away in the household, fewer car trips to the supermarket (e.g. only once a week) and, for semi-prepared food products, more efficient energy use in the food industry. The study shows that consumer actions prove just as important as industrial actions. Recommendations and perspectives  Further research is needed to understand the mechanism for the disposal of food, i.e. the reasons for food being wasted, and the relationship between shopping frequency, retail location, size of packaging, etc. in order to reduce the impact of waste and consumer transport. Responsible editor: Niels Jungbluth  相似文献   

7.

Purpose

In life cycle assessment (LCA), resource availability is currently evaluated by means of models based on depletion time, surplus energy, etc. Economic aspects influencing the security of supply and affecting availability of resources for human use are neglected. The aim of this work is the development of a new model for the assessment of resource provision capability from an economic angle, complementing existing LCA models. The inclusion of criteria affecting the economic system enables an identification of potential supply risks associated with resource use. In step with actual practice, such an assessment provides added value compared to conventional (environmental) resource assessment within LCA. Analysis of resource availability including economic information is of major importance to sustain industrial production.

Methods

New impact categories and characterization models are developed for the assessment of economic resource availability based on existing LCA methodology and terminology. A single score result can be calculated providing information about the economic resource scarcity potential (ESP) of different resources. Based on a life cycle perspective, the supply risk associated with resource use can be assessed, and bottlenecks within the supply chain can be identified. The analysis can be conducted in connection with existing LCA procedures and in line with current resource assessment practice and facilitates easy implementation on an organizational level.

Results and discussion

A portfolio of 17 metals is assessed based on different impact categories. Different impact factors are calculated, enabling identification of high-risk metals. Furthermore, a comparison of ESP and abiotic depletion potential (ADP) is conducted. Availability of resources differs significantly when economic aspects are taken into account in addition to geologic availability. Resources assumed uncritical based on ADP results, such as rare earths, turn out to be associated with high supply risks.

Conclusions

The model developed in this work allows for a more realistic assessment of resource availability beyond geologic finiteness. The new impact categories provide organizations with a practical measure to identify supply risks associated with resources. The assessment delivers a basis for developing appropriate mitigation measures and for increasing resilience towards supply disruptions. By including an economic dimension into resource availability assessment, a contribution towards life cycle sustainability assessment (LCSA) is achieved.  相似文献   

8.
Retrospective estimates of historic abundances and distributions of marine organisms are crucial to understanding the anthropogenic impacts on the structure and species of coastal ecosystems, especially in the case of vulnerable species such as the Dugong (Dugong dugon). The Persian/Arabian Gulf is home to the second largest Dugong population in the world, yet little is known about their current or past abundance, distribution, and ecological role. Here, we examine historical changes in dugong distribution and estimate perceived changes in their abundance. We create a ‘dugong discovery curve’ and compile global density estimates as proxies for the overall health of the population in the Gulf. We find that since 1950 dugong range may have contracted by one quarter, and despite their large population, their overall densities in the Gulf are far lower than in other areas within their range. Basic understanding of historical trajectories for Dugongs is needed in order to develop appropriate management plans and conservation targets, particularly in light of large and wide-spread coastal development projects in the region.  相似文献   

9.
Given widespread concern about the status of elasmobranch fishes globally, information on this group in the Persian (Arabian) Gulf is reviewed comprehensively for the first time. The Arabian region may be of overlooked significance to elasmobranch biogeography, and the environmentally unique Gulf has some highly distinctive elements of biodiversity: an endemic and critically endangered rajid skate, a rarely recorded carcharhinid shark, and preliminary molecular studies which indicate intriguing levels of distinctness from conspecifics elsewhere in the Indo-Pacific. Elasmobranchs also have a long history of association with, and exploitation by, humans around the Gulf. Despite this, Gulf elasmobranchs have been poorly researched, probably due to their low esteem as food. Information is scattered through a variety of literature, and only a handful of published works have been primarily concerned with aspects relevant to management. Key areas of concern include large reported landings by Iran; the export of fins to east Asian markets (particularly through the United Arab Emirates); potentially increasing demand for elasmobranchs for pharmaceutical products and human consumption; a reported change in elasmobranch community structure along the Iranian coast; and major degradation of the Gulf’s shallow, semi-enclosed environment. Priorities for research in the near future should include: resolution of taxonomic issues; species-level monitoring and reporting of fisheries landings by all Gulf states (including the species, pathways and fisheries involved in the fin trade locally); establishing the degree of connectivity of Gulf populations to those in adjacent waterbodies; and identification of key spatio-temporal sensitivities.  相似文献   

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11.
Identification of microbial communities within shoreline sediments and sediment precipitates from the Tigris-Euphrates delta (northern Kuwait) were determined by microscopic/nanoscopic studies, and by molecular analysis. Oncolites are syn-diagenetic carbonate precipitates that are surviving in a shallow subtidal to intertidal siliciclastic environment with periodically excessive hydraulic energy, extreme salinity (up to 47 per mil), and high concentrations of organic matter. X-ray diffraction techniques reveal that oncolite cortices are predominantly composed of calcite, quartz, halite and dolomite, associated with minor fractions of clay minerals. Quantitative analysis of the Corey Shape Factor reveals distinct morphological populations but with local overlap. A plot of the Equivalent Diameter vs. Corey Shape Factor provided the best indicator of the morphological relationships within the total oncolite population, indicating a hydrodynamically controlled morphological distribution defining intertidal and subtidal oncolite classes. Direct microscopic examination of the samples indicates that diatoms are the most abundant eukaryotic algae in subtidal sediments and within actively precipitating carbonate cements, especially the genus Navicula. In contrast, filamentous cyanobacteria from the genus Anabaena are most abundant in the intertidal zone sediments. The PCR-DGGE of the 16SrRNA gene of the cyanobacteria shows a higher diversity for this genus of bacteria in all sediment samples and that the cyanobacterial population in the diagenetically precipitating oncolites are closely related to the population found in the subtidal sediments. Dunaliella viridis dominates the culturable algae obtained from the four tidal zones. Our results indicate that a range of microbial populations are actively contributing to the formation of microbially-induced sedimentary structures in the extreme conditions of the southern Tigris-Euphrates delta.  相似文献   

12.
The Brookings Institute analysis rate both Lexington and Louisville, Kentucky (USA) as two of the nation's largest carbon emitters. This high carbon footprint is largely due to the fact that 95% of electricity is produced from coal. Kentucky has limited options for electric power production from low carbon sources such as solar, wind, geothermal, and hydroelectric. Other states (TN, IN, OH, WV, and IL) in this region are similarly limited in renewable energy capacity. Bioenergy agriculture could account for a proportion of renewable energy needs, but to what extent is unclear. Herein, we found that abandoned agricultural land, not including land that is in fallow or crop rotation, aquatic ecosystems, nor plant-life that had passed through secondary ecological succession totaled 1.9 Mha and abandoned mine-land totaled 0.3 Mha, which combined accounted for 21% of Kentucky's land mass. A life cycle assessment was performed based on local yield and agronomic data for native grass bioenergy agriculture. These data showed that utilizing Kentucky's marginal land to grow native C 4 grasses for cellulosic ethanol and bioelectricity may account for up to 13.3% and 17.2% of the states 2 trillion MJ energy consumption and reduce green house gas emissions by 68% relative to gasoline.  相似文献   

13.
Presented is a phylogenetic reconstruction of mudskippers using sequences of the mitochondrial COI and cytb genes. The phylogeny combines the sequences of 12 species from GenBank with those of three species (Boleophthalmus dussumieri, Periophthalmus waltoni and Scartelaos tenuis) collected from the coastal area of the Persian Gulf and Oman (Makran) Sea and sequenced for the first time. Based on the Maximum likelihood and Bayesian methods, Periophthalmus forms a separate clade that is the sister lineage to a group formed by all remaining genera. The subfamilies Oxudercinae and Amblyopinae established on the basis of morphological characters have been shown to be paraphyletic and their use as taxonomic units is no longer recommended. The evolution of Periophthalmus waltoni, Periophthalmus barbarous and Boleophthalmus dussumieri is discussed based on molecular phylogenetic reconstruction.  相似文献   

14.
Three species of the cosmopolitan genus Ulva (U. paschima , U. chaugulii and U. ohnoi ) from the Persian Gulf were identified using morphological and molecular markers, and were analyzed for total lipids, fatty acids, proteins and amino acid profiles. Our results show that the studied Ulva species have high protein content (9?25% dry weight), contain essential fatty acids and nearly all essential amino acids. This suggests Ulva could have potential as a form of human nutrition and animal feed with a low carbon footprint.  相似文献   

15.

Purpose

In life cycle assessment (LCA), literature suggests accounting for land as a resource either by what it delivers (e.g., biomass content) or the time and space needed to produce biomass (land occupation), in order to avoid double-counting. This paper proposes and implements a new framework to calculate exergy-based spatial explicit characterization factors (CF) for land as a resource, which deals with both biomass and area occupied on the global scale.

Methods

We created a schematic overview of the Earth, dividing it into two systems (human-made and natural), making it possible to account for what is actually extracted from nature, i.e., the biomass content was set as the elementary flow to be accounted at natural systems and the land occupation (through the potential natural net primary production) was set as the elementary flow at human-made systems. Through exergy, we were able to create CF for land resources for these two different systems. The relevancy of the new CF was tested for a number of biobased products.

Results and discussion

Site-generic CF were created for land as a resource for natural systems providing goods to humans, and site-generic and site-dependent CF (at grid, region, country, and continent level) were created for land as a resource within human-made systems. This framework differed from other methods in the sense of accounting for both land occupation and biomass content but without double-counting. It is set operationally for LCA and able to account for land resources with more completeness, allowing spatial differentiation. When site-dependent CF were considered for land resources, the overall resource consumption of certain products increased up to 77 % in comparison with site-generic CF-based data.

Conclusions

This paper clearly distinguished the origin of the resource (natural or human-made systems), allowing consistent accounting for land as a resource. Site-dependent CF for human-made systems allowed spatial differentiation, which was not considered in other resource accounting life cycle impact assessment methods.  相似文献   

16.
A Life Cycle Assessment (LCA) was carried out for milk production extending from the origin of the inputs to the agricultural step to the consumer phase and the waste management of the packaging. Three Norwegian dairies of different sizes and degree of automation were studied. The main objectives were to find any hot spots in the life cycle of milk, to determine the significance of the dairy size and degree of automation, and to study the influence of transport. The agriculture was found to be the main hot spot for almost all the environmental themes studied, although the dairy processing, packaging, consumer phase and waste management were also of importance. The consumer phase was the main contributor to photo-oxidant formation and important regarding eutrophication. The small dairy was found to have a greater environmental impact than the middle-sized and the largest dairies. The transport did not have any major influence.  相似文献   

17.

Purpose

Life cycle assessment (LCA) methodology is a well-established analytical method to quantify environmental impacts, which has been mainly applied to products. However, recent literature would suggest that it has also the potential as an analysis and design tool for processes, and stresses that one of the biggest challenges of this decade in the field of process systems engineering (PSE) is the development of tools for environmental considerations.

Method

This article attempts to give an overview of the integration of LCA methodology in the context of industrial ecology, and focuses on the use of this methodology for environmental considerations concerning process design and optimization.

Results

The review identifies that LCA is often used as a multi-objective optimization of processes: practitioners use LCA to obtain the inventory and inject the results into the optimization model. It also shows that most of the LCA studies undertaken on process analysis consider the unit processes as black boxes and build the inventory analysis on fixed operating conditions.

Conclusions

The article highlights the interest to better assimilate PSE tools with LCA methodology, in order to produce a more detailed analysis. This will allow optimizing the influence of process operating conditions on environmental impacts and including detailed environmental results into process industry.  相似文献   

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Abstract.
  • 1 Food demands of the predatory carabid Notiophilus biguttatus F. and their fulfilment were studied in the laboratory and field.
  • 2 In the laboratory, larval consumption, growth, adult body size and egg production were established for different regimes of temperature and food, the springtail Orchesella cincta.
  • 3 Temperature strongly influenced feeding rate of larvae and adults and consequently growth and oviposition rates. Accordingly, growth rate and ovi-position rate increased with prey supply.
  • 4 Prey supply also had an effect on fat content, but the number of ripe eggs in the ovaries was related neither to temperature nor to prey supply.
  • 5 Adult body size was affected by temperature during the larval period but more so by food supply.
  • 6 Dissection of field fresh females showed them to bear eggs for the whole year, except in late winter/early spring and in July.
  • 7 Fat content was low in spring and, from July on, high in summer and autumn. Survivorship during starvation differed widely between samples and seemed to be related to reproductive status rather than to fat content.
  • 8 Samples of beetles and springtails from eleven pine plantations revealed for the beetles significant differences in fat content and body size, the latter ranging between the maximum and minimum value obtained in the laboratory.
  • 9 Conclusions about food limitation based on body size and fat content were not corroborated by a relationship of these indices with springtail density.
  相似文献   

20.

Purpose

The wood panel industry is one of the most important forest-based industries in Brazil. The medium density particleboard (MDP) is currently produced and consumed worldwide and represents about 50 % of the wood panel industry in Brazil. Unlike other regions, Brazilian MDP is produced from dedicated eucalyptus plantations and heavy fuel oil is an important energy source in MDP manufacture, which may result in a different environmental profile. This paper presents a life cycle assessment of MDP panel produced in Brazil and suggests improvement opportunities by assessing alternative production scenarios.

Methods

The cradle-to-gate assessment of 1 m3 of MDP produced in Brazil considered two main subsystems: forest and industrial production. Detailed inventories for Brazilian eucalyptus production and MDP industrial production were collected as a result of technical visits to Brazilian MDP producers (foreground systems) as well as literature review (mainly background systems). The potential environmental impacts of MDP were assessed in terms of seven impact categories using CML (abiotic depletion, acidification, global warming, eutrophication, and photochemical oxidation) and USEtox (ecotoxicity and human toxicity) impact assessment methods in order to identify the main hotspots.

Results and discussion

The industrial production was responsible for most of the impacts in all impact categories, except ecotoxicity (EC). The main hotspots identified were the use of heavy fuel oil (HFO) as a thermal energy source in MDP manufacture and the production of urea–formaldehyde (UF) resin used as synthetic adhesive. Glyphosate herbicide application in soil in forestry operations was the main responsible for the impacts in EC. Scenarios for HFO substitution were assessed and results showed that substituting HFO for in-mill wood residues or diesel leads to reduced environmental impacts.

Conclusions

The identification of the main hotspots in the MDP life cycle can assist the wood panel industry to improve their environmental profile. Further research should focus on UF resin production in order to reduce its environmental impacts as well as the possibility of using alternatives resins. Other sources of wood for MDP production could also be investigated (e.g., pine wood and wood residues) to assess potential improvements.  相似文献   

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