Ecological role of the giant root‐rat (Tachyoryctes macrocephalus) in the Afroalpine ecosystem          下载免费PDF全文

Jan ŠKLÍBA  Tereza VLASATÁ  Matěj LÖVY  Ema HROUZKOVÁ  Yonas MEHERETU  Claudio SILLERO‐ZUBIRI  Radim ŠUMBERA 《Integrative zoology》2017,12(4):333-344

Rodents with prevailing subterranean activity usually play an important role in the ecosystems of which they are a part due to the combined effect of herbivory and soil perturbation. This is the case for the giant root‐rat Tachyoryctes macrocephalus endemic to the Afroalpine ecosystem of the Bale Mountains, Ethiopia. We studied the impact of root‐rats on various ecosystem features within a 3.5‐ha study locality dominated by Alchemilla pasture, which represents an optimal habitat for this species, in 2 periods of a year. The root‐rats altered plant species composition, reducing the dominant forb, Alchemilla abyssinica, while enhancing Salvia merjame and a few other species, and reduced vegetation cover, but not the fresh plant biomass. Where burrows were abandoned by root‐rats, other rodents took them over and A. abyssinica increased again. Root‐rat burrowing created small‐scale heterogeneity in soil compactness due to the backfilling of some unused burrow segments. Less compacted soil tended to be rich in nutrients, including carbon, nitrogen and phosphorus, which likely affected the plant growth on sites where the vegetation has been reduced as a result of root‐rat foraging and burrowing.  相似文献   

William John Stevenson     

KL Hughes 《Australian veterinary journal》2005,83(5):299-299

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Ray Liver Oils Obtained by Different Methodologies: Characterization and Refining     

Daniela Lorena Lamas  Agueda Elena Massa 《Journal Of Aquatic Food Product Technology》2019,28(5):555-569

Currently, the use of by-products generated from fish processing is a relevant issue for the sustainable development of the fisheries. Fins are the main commercialized product of cartilaginous species. However, the livers contain a high content of polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These fatty acids have been exhaustively studied due to their remarkable benefits to human health. In the present work, different methodologies were investigated to extract oil from the livers of Zearaja flavirostris and Atlantoraja castelnaui. Enzyme-assisted processes, cold extractions, and high temperatures were studied. The extraction with enzymes was the most efficient in both species. The oils obtained presented physicochemical and quality parameters suitable for its refinement and commercialization. Palmitic (C16:0) and oleic acid (C18:1) were the most abundant saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs), respectively. Both species showed similar content of DHA; however, the oil of Z. flavirostris had twice as much EPA than A. castelnaui. The results suggest that the livers of the species studied can be used as a source of valuable oils, rich in PUFAs, as a viable alternative for the integral use of these resources.  相似文献   

Alexander Kennedy Sutherland, OAM     

KL Hughes  JH Arundel 《Australian veterinary journal》2000,78(1):58-58

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Communicating the risks of handling bats: analysing approaches used by Australian stakeholders in the context of Australian bat lyssavirus     

BP Liang  K Wingett  KL Bosward  MR Taylor 《Australian veterinary journal》2023,101(11):430-439

Australian bat lyssavirus (ABLV) is a member of the Lyssavirus genus of the Rhabdoviridae family and is found in Australian bat species. It is of public health concern because of the rabies-like syndrome it causes in humans, resulting in government health and wildlife agencies using varied communication approaches to inform targeted audiences about zoonotic risks associated with handling bats. Despite these warnings, the number of reports of human-bat interactions remains high. This paper details a survey conducted to analyse the approaches utilised by a range of stakeholders to educate and communicate warnings to their target audiences. The survey focused on identifying the target audiences, communication methods used, along with the message frequency, content, and perceived effectiveness. Analysis of the top three messages delivered by stakeholders revealed that over half were information-focused messages and over a third, instruction-focused. Stakeholders identified the need to balance messaging about bat handling risks with information regarding the vulnerable status of bats and their environmental significance. Whilst the most common and (perceived) effective method of communication was one-on-one discussions, it was also identified to be ineffective for targeting mass audiences leading stakeholders to recognise the need to adapt to more efficient means of communication. The outcomes of this study may be useful to improve risk communication strategies regarding ABLV in Australia.  相似文献   

Nonrandom processes maintain diversity in tropical forests     

Wills C  Harms KE  Condit R  King D  Thompson J  He F  Muller-Landau HC  Ashton P  Losos E  Comita L  Hubbell S  Lafrankie J  Bunyavejchewin S  Dattaraja HS  Davies S  Esufali S  Foster R  Gunatilleke N  Gunatilleke S  Hall P  Itoh A  John R  Kiratiprayoon S  de Lao SL  Massa M  Nath C  Noor MN  Kassim AR  Sukumar R  Suresh HS  Sun IF  Tan S  Yamakura T  Zimmerman J 《Science (New York, N.Y.)》2006,311(5760):527-531

An ecological community's species diversity tends to erode through time as a result of stochastic extinction, competitive exclusion, and unstable host-enemy dynamics. This erosion of diversity can be prevented over the short term if recruits are highly diverse as a result of preferential recruitment of rare species or, alternatively, if rare species survive preferentially, which increases diversity as the ages of the individuals increase. Here, we present census data from seven New and Old World tropical forest dynamics plots that all show the latter pattern. Within local areas, the trees that survived were as a group more diverse than those that were recruited or those that died. The larger (and therefore on average older) survivors were more diverse within local areas than the smaller survivors. When species were rare in a local area, they had a higher survival rate than when they were common, resulting in enrichment for rare species and increasing diversity with age and size class in these complex ecosystems.  相似文献   

Coliform detection from river waters: Comparison between MPN and MF techniques     

S. Massa  Maria Grandi  G. Poda  Daniela Cesaroni  F. Cangamella  L.D. Trovatelli 《Water, air, and soil pollution》1989,43(1-2):135-145

This paper compares three different methods used to determine fecal pollution in river water. Two of the methods are based on direct estimation using standard aerobic incubation of membrane filters (S-MF) and anaerobic incubation of membrane filters (A-MF); the third is based on statistical evaluation by the most probable number method (MPN). It was seen from regression analysis of the results obtained that the MPN, S-MF and A-MF techniques are equally valid as regards the enumeration of fecal coliforms, whereas the S-MF and A-MF techniques are more sensitive than the MPN procedure for the enumeration of total coliforms.  相似文献   

The effects of lactation on the fertility of dairy cows   总被引：1，自引：0，他引：1  

KL MACMILLAN  IJ LEAN†  CT WESTWOOD† 《Australian veterinary journal》1996,73(4):141-147

Lactation has been negatively associated with fertility because pregnancy rates in maiden heifers exceed those obtained after first or subsequent calvings. The extent of this difference is less in pasture-fed dairy cows (<10%) than in American Holsteins (>20%) fed grain and conserved forages. The latter cows have pregnancy rates to first insemination and oestrus detection rates of only 40 to 45%. This suggests that the subsequent fertility of inherently fertile Holstein heifers may be severely compromised by high levels of milk production. International comparisons show that pasture-fed dairy cows may experience extended periods of anovulatory anoestrum but have normal fertility (60% pregnancy rate to first insemination) once cycling. The high-producing American Holstein may ovulate within 4 weeks postpartum but is more likely to continue ovulating without being detected in oestrus. Both situations are associated with negative energy balances (NEB) during early lactation. The severity and duration of this NEB may vary with body condition at calving, age or parity, ration formulation, production level and environmental factors. Relative daily milk yield is not an absolute indicator of NEB, because some lower producing cows within a herd have lower feed intakes and more severe energy deficits. NEB is not simple to measure; nonetheless, it is correlated with genetic improvement for milk yield. A positive energy balance, greater weight gain and higher body condition score have all been shown to be positively correlated with plasma progesterone concentrations in early lactation. No studies have investigated the possibility that the rapid increase in metabolic rate at this time may also alter steroid concentrations with consequent effects on oestrous behaviour and fertility. Studies to more precisely define the effects of increasing milk yields in early lactation, especially in Holsteins, may need to be completed in Australia and New Zealand. Oestrus detection rates and pregnancy rates for American Holsteins of less than 50% are accepted widely in the USA. Such low detection rates confound studies on fertility. The objective should be to increase these 2 rates to at least 80% and 60% respectively. This may involve the use of controlled breeding, especially if oestrous behaviour is less overt in high-producing Holstein cows.  相似文献   

Myofibroblastic fibrosarcoma with multifocal osseous metaplasia at the site of equine influenza vaccination     

NJ Kannegieter  KL Schaaf  DK Lovell  CD Simon  BM Stone 《Australian veterinary journal》2010,88(4):132-136

We describe a fibrosarcoma in a 12-year-old Quarterhorse × Arabian gelding as a sequela to equine influenza vaccination. Shortly after the second vaccination, swelling at the site was noticed by the owner and it continued to increase in size over the following 6 months. Biopsy of the mass indicated a fibrosarcoma had developed at the vaccination site. It was approximately 20 cm in diameter and elevated well above the level of the skin. There was no clinical evidence of metastases to the lungs or local lymph nodes. Surgical resection of the mass was performed and the wound healed by first and second intention. Histopathological examination and immunohistochemical staining confirmed a myofibroblastic fibrosarcoma with multifocal osseous metaplasia. To the authors' knowledge, this is the first equine case of a vaccine-associated fibrosarcoma.  相似文献   

Erratum     

ML Lepherd  PJ Canfield  GB Hunt  PC Thomson  KL Bosward 《Australian veterinary journal》2011,89(7):238-238

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