6,066 research outputs found
Temperature, organic matter and the sustainability of aquatic systems
Changes in sustainability of aquatic ecosystems are likely to be brought about by the global warming that has been widely predicted. In this article, the effects of water temperature on water-bodies (lakes, oceans and rivers) are reviewed followed by the effects of temperature on aquatic organisms. Almost all aquatic organisms require exogenous heat before they can metabolise efficiently. An organism that is adapted to warm temperatures will have a higher rate of metabolism of food organisms and this increases feeding rate. In addition, an increase in temperature raises the metabolism of food organisms, so food quality can be altered. Where populations have a different tolerance to temperature the result is habitat partitioning. One effect of prolonged high temperature is that it causes water to evaporate readily. In the marine littoral this is not an important problem as tides will replenish water in pools. Small rain pools are found in many tropical countries during the rainy season and these become incompletely dried at intervals. The biota of such pools must have resistant stages within the life cycle that enable them to cope with periods of drying. The most important potential effects of global warming include (i) the alteration of existing coastlines, (ii) the development of more deserts on some land masses, (iii) higher productivity producing higher crop production but a greater threat of algal blooms and (iv) the processing of organic matter at surface microlayers
Maize silage for dairy cows: mitigation of methane emissions can be offset bij and use change
Increasing the digestibility of cattle rations by feeding grains and whole plant silages from maize have been identified as effective options to mitigate greenhouse gas emissions. The effect of ploughing grassland for maize crops have not been taken into account yet. A intensive dairy farm is used as an example to demonstrate the trade offs by this type of land use change when more maize silage is fed to dairy cows. The model DAIRY WISE has been used to calculate the mitigation by the changed ration, the Introductory Carbon Balance Model to calculate the changes in soil organic carbon and nitrogen caused by ploughing grassland for maize crops. The losses of soil carbon and the loss of sequestration potential are much larger than the annual mitigation by feeding more maize. The ecosystem carbon payback time defines the years of mitigation that are needed before the emissions due to land use change are compensated. For ploughing grassland on sandy soils, the carbon payback time is 60 years. A higher global warming potential for methane can reduce the carbon payback time with 30%. Ploughing clay soils with a higher equilibrium level of soil organic matter increases the payback time by maximally 70%. The payback times occur only in the case of permanent maize cropping, grass maize rotations cause annual losses of nitrous oxide that are larger than the mitigation by feeding more maize
Sex workers who provide services to clients with disability in New South Wales, Australia
Aims: Sexuality and sexual needs/desires of people with disability have historically been overlooked amongst the general public. Long standing social attitudes and stereotypes have fundamentally dictated that people with disabilities cannot and should not express their sexual agency. In particular, when people with disability have sought to express their sexual needs via the services of a sex worker, this has tended to provoke much social and political ire. This research is an exploratory study about sex workers who provide services to clients with disability. The aim of this research is to identify the nature and extent of such activities to produce empirical data to support anecdotal evidence and recent emerging research in this field. Method: This exploratory online survey asked sex workers who worked in New South Wales (NSW) to share their experiences of providing services to clients with disability. This included the frequency, type and range of services provided, location of service delivery and how clients made contact. Questions were asked regarding third party assistance and the identification of any barriers or challenges faced by sex workers. The survey also encouraged sex workers to share personal reflections on what they thought were the most positive aspects of their work. Results: The findings, from 65 respondents, indicate that sex workers in NSW have provided a wide range of sexual services to clients with disability across the state. The sex workers’ ages ranged from 21 to 61 years, identifying as either female, male or transgender. Services were provided in varied locations including brothels, massage parlours, private homes, hotels, nursing homes, the client’s hospital room or their client’s group home/ supported accommodation. Their clients’ disabilities were quite expansive, spanned both physical and cognitive disabilities and acquired and congenital disabilities. A number of issues and barriers were identified that concerned the client, carers, support staff and / or family and friends of the client. Forty seven sex workers shared their personal perspectives of what they considered the most positive aspects in providing services to clients with disability. Conclusions: The respondents’ narratives revealed their professional enthusiasm with interacting with clients with disability. This includes a desire to have further training and support to alleviate barriers and challenging situations that impede clear communication and supportive pathways between themselves and their clients. These results also contribute to an awareness of how decriminalisation can provide a supportive environment for this to occur. This study builds upon an expanding body of work that can be used to educate and influence the future development of training and awareness workshops for sex workers, disability services provider, clients with a disability, academics, policy makers and the general public
Family Member Experiences With Augmentative And Alternative Communication Systems Used By Nonspeaking Autistic Individuals
Nonspeaking autistic individuals who have no way to communicate cannot share their thoughts, dreams, or desires. The purpose of this qualitative narrative inquiry was to explore the experiences of family members of nonspeaking autistic individuals who use augmentative and alternative communication (AAC) systems. This study documented family members’ experiences of identifying, learning, and implementing two types of AAC: Rapid Prompting Method and Spelling to Communicate. Through one-on-one interviews, five participants shared their lived experiences. Three themes emerged from the data. The first theme was an increase in well-being for the entire family. All five participants described transformations and improvements in life not only for their speller, but for the entire family. There was an increase in well-being both physically and emotionally for spellers and their families. The second theme was a remarkable improvement from the past. All five families shared changes to communication and, for their nonspeaking autistic family member, shared a dramatic shift in the social aspect of their family member. They also shared major improvements in self-injurious behaviors. The third theme was that learning and implementing AAC was laborious but beneficial for the communication partner. They all described the commitment it took and that it was worth every minute. Each participant talked about sharing the benefits and changes with other families. All of the participants encouraged families who might be considering spelling as AAC
Studies on blackflies (Diptera: Simuliidae) breeding in bog streams in upper Teesdale
This study, on the immature stages of the Simuliidae, was undertaken in streams draining bogs in Upper Teesdale. There were four parts to the investigation: Firstly, a qualitative survey of fourteen sites showed eleven of the thirty-five British species of Simuliids to be present. Secondly, quantitative programmes showed streams to have three types of population structure: those with larvae present mainly in winter; mainly in summer; and throughout the year. Most streams were in the latter two categories, larval numbers being lower in winter at the higher altitudes. In summer 1972, absolute population estimates were obtained from two streams by removal trapping. More larvae occurred in the lower sections of the streams and, in the streams where the winter populations were low, larval numbers were larger early in summer; this was not true of the lower altitude stream. Thirdly, cumulative frequency x size-measurement plots were made on probability paper from which the modal size-classes corresponding to the larval instars of each species could be determined. All species had seven larval instars and percentage frequency distributions for each sampling date were constructed. The detailed population biology could then be determined. Larval life was much shorter in summer at 30-40 days than in winter. Two generations were distinguished, that in winter commonly having two cohorts and that in summer often as many as four
Do benthic biologists pay enough attention to aggregates formed in the water column of streams and rivers?
Comparative genomics of vertebrate Fox cluster loci.
Published onlineComparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tThis is the final version of the article. Available from BioMed Central via the DOI in this record.BACKGROUND: Vertebrate genomes contain numerous duplicate genes, many of which are organised into paralagous regions indicating duplication of linked groups of genes. Comparison of genomic organisation in different lineages can often allow the evolutionary history of such regions to be traced. A classic example of this is the Hox genes, where the presence of a single continuous Hox cluster in amphioxus and four vertebrate clusters has allowed the genomic evolution of this region to be established. Fox transcription factors of the C, F, L1 and Q1 classes are also organised in clusters in both amphioxus and humans. However in contrast to the Hox genes, only two clusters of paralogous Fox genes have so far been identified in the Human genome and the organisation in other vertebrates is unknown. RESULTS: To uncover the evolutionary history of the Fox clusters, we report on the comparative genomics of these loci. We demonstrate two further paralogous regions in the Human genome, and identify orthologous regions in mammalian, chicken, frog and teleost genomes, timing the duplications to before the separation of the actinopterygian and sarcopterygian lineages. An additional Fox class, FoxS, was also found to reside in this duplicated genomic region. CONCLUSION: Comparison of loci identifies the pattern of gene duplication, loss and cluster break up through multiple lineages, and suggests FoxS1 is a likely remnant of Fox cluster duplication.We thank Peter Holland and Dave Ferrier for their discussions on this project and John Mulley for supplying the Amia calva genomic DNA, and for comments on the manuscript. This work was supported by the BBSRC
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