Blood-gas properties of plateau zokor (Myospalax baileyi)

Plateau zokor (Myospalax baileyi) is one of the blind subterranean mole rats that spend their life solely underground in scaled burrows. It is one of the special species of the Qinghai-Tibet plateau. In their burrows, oxygen is low and carbon dioxide is high and their contents fluctuate with the change of seasons, soil types, rain and depth of burrows. However, plateau zokors show successful adaptation to that extreme environment. In this study, their adapting mechanisms to the hypoxic hypercapnic environment were analyzed through the comparison of their blood-gas properties with that of pikas (Ochotona curzniae) and Sprague-Dawley rats. The results indicated that plateau zokors had higher red blood corpuscle counts (8.11 +/- 0.59 (10(12)/L)) and hemoglobin concentrations (147 +/- 9.85 g/L), but hematocrit (45.9 +/- 3.29%) and mean corpuscular volume (56.67 +/- 2.57 fL) were lower than the other rodents. Their arterial blood and venous blood pH were 7.46 +/- 0.07 and 7.27 +/- 0.07. Oxygen pressure in arterial blood of plateau zokors was about 1.5 times higher than that of pikas and rats, and it was 0.36 and 0.26 times in their venous blood. Partial pressure for carbon dioxide in arterial and venous blood of plateau zokors was 1.5-fold and 2.0-fold higher, respectively, than in rats and pikas. Oxygen saturation of plateau zokors was 5.7 and 9.3 times lower in venous blood than that of pikas and rats, respectively. As result, the difference of oxygen saturation in arterial blood to venous blood was 2- and 4.5-fold higher in plateau zokors as that of pikas and rats, respectively. In conclusion, plateau zokors had a high tolerance to pH changes in tissues, together with strong capabilities to obtain oxygen from their hypoxic-hypercapnic environment. (c) 2006 Published by Elsevier Inc.

The impact of plateau zokor Myospalax fontanierii burrows on alpine meadow vegetation on the Qinghai-Xizang (Tibetan) plateau

The impact of burrows constructed by plateau zokors Myospalax fontanierii (Milne-Edwards, 1867) on alpine meadow vegetation on the Qinghai-Xizang (Tibetan) plateau was investigated. Plant samples taken from quadrats directly over active zokor burrows, back-filled burrows, adjacent burrow controls, and random sites from a field, in which no burrows or mounds occurred were compared. The biomass of plants (below- and above-ground) directly over shallow active burrows was significantly lower than on control plots. This reduction in biomass was not significantly different than that between deep active burrows and control plots. There were no significant differences between above- and below-ground plant biomass on areas perpendicular to active burrows when compared to random sites. Back-filling soil in burrows could promote the growth of above-ground monocotyledonous plants. However, the burrowing activities of zokors had a negative effect on biomass of dicotyledonous plants.

���������������������������������������������������������(������)

Burrowing behaviors of the plateau zokors ( Myospalax bailely) in relation to soil hardness were investigated by using radio2telemetry at Haibei Alpine Meadow Ecosystem Research Station ,Qinghai , China. The results showed that there were no differences of burrowing behaviors and the efficiencies of the excavating segment between male and female , except the digging duration of the male was longer than that of the female in the same soil. With increase of soil hardness , digging duration in incisors significantly increased , but dried soil mass dug out by the zokors in each bout reduced. Mean-while the field investigation also showed that soil hardness affected the distribution of the zokor.

Burrowing rodents as ecosystem engineers: the ecology and management of plateau zokors Myospalax fontanierii in alpine meadow ecosystems on the Tibetan Plateau

1. Plateau zokors, Myospalax fontanierii, are the only subterranean herbivores on the Tibetan plateau of China. Although the population biology of plateau zokors has been studied for many years, the interactions between zokors and plants, especially for the maintenance and structure of ecological communities, have been poorly recognized. In the past, plateau zokors have been traditionally viewed as pests, competitors with cattle, and agents of soil erosion, thus eradication programmes have been carried out by local governments and farmers. Zokors are also widely and heavily exploited for their use in traditional Chinese medicine.2. Like other fossorial animals, such as pocket gophers Geomys spp. and prairie dogs Cynomys spp. in similar ecosystems, zokors may act to increase local environmental heterogeneity at the landscape level, aid in the formation, aeration and mixing of soil, and enhance infiltration of water into the soil thus curtailing erosion. The changes that zokors cause in the physical environment, vegetation and soil clearly affect the herbivore food web. Equally, plateau zokors also provide a significant food source for many avian and mammalian predators on the plateau. Zokor control leading to depletion of prey and secondary poisoning may therefore present problems for populations of numerous other animals.3. We highlight the important role plateau zokors play in the Tibetan plateau ecosystem. Plateau zokors should be managed in concert with other comprehensive rangeland treatments to ensure the ecological equilibrium and preservation of native biodiversity, as well as the long-term sustainable use of pastureland by domestic livestock.

Effects of plateau zokors (Myospalax Fontanierii) on plant community and soil in an alpine meadow

Effects of plateau zokors (Myospalax fontanierii) on seasonal above- and belowground plant biomass, plant species diversity, and soil moisture and organic matter were examined at an alpine meadow site in Qinghai Province, People's Republic of China. Above- and belowground biomass increased significantly in areas where zokors were removed or burrow systems were abandoned for 5 years compared with areas that zokors had occupied for >10 years. Biomass of monocotyledons was reduced greatly, but biomass of nonpalatable dicotyledons increased significantly, in occupied areas. Diversity of dicotyledons, monocotyledons, and total plants in unoccupied areas was significantly greater than in occupied or abandoned areas. Vegetation cover and height in occupied areas were significantly less than in unoccupied and abandoned areas. No consistent effect by zokors on soil moisture and organic matter was observed.

Effect of plateau zokors on vegetation characteristics and productivity of alpine meadow

This research was conducted on alpine meadow site at Menyuan county, Qinghai Province, People's Republic of China to determine the effects of native, subterranean rodent of Qinghai-Tibet grasslands, the plateau zokors (Myospalax baileyi), on seasonal above-and below-ground plant biomass, plant species diversity and productivity. Both total peaks of above-and below-ground biomass were the greatest (413.600 g/m~2 and 2297.502 g/m~2) in the patch no any plateau zokors colonized by plateau zokors over 10 years in August and October, respectively. Both above-and below-ground biomass were significantly increased in the patches where plateau zokors were removed or the burrow systems were abandoned for five years compared to the patches plateau zokors colonized over 10 years. However, both above-and below-ground biomass in abandoned patches were significantly lower than that in uncolonized patches. Monocotyledonous biomass was reduced greatly, but the non-palatable dicots were significantly increased in colonized patches. The palatable biomass of monocots and dicots were increased in abandoned patches. Total plant species diversity was the greatest in uncolonized patchesand least in abandoned patch. The total net primary production in colonized patches was reduced by 68.98% compared with uncolonized patches. Although the patches were without any plateau zokors disturbance for fives years, the total net primary production just reached 58.69% of the uncolonized patches. The above-ground net primary production in abandoned patches increased 28.74% and the below-ground increased 54.91% compared with the colonized patches. We suggest that plateau zokor-induced changes in plant above- and below-ground biomass and species diversity may lead to further alterations of nutrient cycling and trophic dynamics in this alpine meadow ecosystem.

Diet shift of upland buzzards (Buteo hemilasius): evidence from stable carbon isotope ratios

We measured the stable carbon isotope ratios for muscle of the upland buzzards (Buteo hemilasius), plateau pika (Ochotoma curzoniae), root vole (Microtus oeconomus), plateau zokor (Myospalax fontanierii) and passerine bird species at the Haibei Alpine Meadow Ecosystem Research Station (HAMERS), and provided diet information of upland buzzards with the measurement of stable carbon isotopes in tissues of these consumers. The results showed that ��~(13)C values of small mammals and passerine bird species ranged from -25.57��� to -25.78��� (n = 12), and from -24.81��� to -22.51% (n = 43), respectively, ��~(13)C values of the upland buzzards ranged from -22.60��� to -23.10��� when food was not available. The difference in ��~(13)C values (2.88�����0.31���) between upland buzzards and small mammals was much larger than the differences reported previously, 1���-2���, and showed significant difference, while 1.31�����0.34��� between upland buzzard and passerine bird species did not differ from the previously reported trophic fractionation difference of 1���-2���. Estimation of trophic position indicated that upland buzzards stand at trophic position 4.23, far from that of small mammals, i.e., upland buzzards scarcely captured small mammals as food at the duration of food shortage. According to isotope mass balance model, small mammals contributed 7.89% to 35.04% of carbon to the food source of the upland buzzards, while passerine bird species contributed 64.96% to 92.11%. Upland buzzards turned to passerine bird species as food during times of shortage of small mammals. ��~(13)C value, a useful indicator of diet, indicates that the upland buzzards feed mainly on passerine bird species rather than small mammals due to "you are what you eat" when small mammal preys are becoming scarce.

Genetic diversity of the subterranean Gansu zokor in a semi-natural landscape

We studied the relationship between genetic diversity of the subterranean Gansu zokor Myospalax cansus and habitat variability in the Loess Plateau, Qinghai Province, China. We used a combination of geographic information systems and molecular techniques to assess the impact of habitat composition and human activities on the genetic diversity of zokor populations in this semi-natural landscape. Although they occurred relatively infrequently in the landscape, woodland and high-coverage grassland habitats were the main positive contributors to the genetic diversity of zokor populations. Rural residential land, plain agricultural land and low-coverage grassland had a negative effect on genetic diversity. Hilly agricultural land and middle-coverage grassland had little impact on zokor genetic diversity. There were also interactions between some habitat types, that is, habitat types with relatively better quality together promoted conservation of genetic diversity, while the interaction between (among) bad habitat types made situations worse. Finally, habitat diversity, measured as patch richness and Shannon's diversity index, was positively correlated with the genetic diversity. These results demonstrated that: (1) different habitat types had different effects on the genetic diversity of zokor populations and (2) habitat quality and habitat heterogeneity were important in maintaining genetic diversity. Habitat composition was closely related to land use thus emphasizing the importance of human activities on the genetic diversity of subterranean rodent populations in this semi-natural landscape. Although the Gansu zokor was considered to be a pest species in the Loess Plateau, our study provides insights for the management and conservation of other subterranean rodent species.

Summer diet of two sympatric species of raptors Upland Buzzard (Buteo hemilasius) and Eurasian Eagle Owl (Bubo bubo) in alpine meadow: problem of coexistence

Summer diets of two sympatric raptors Upland Buzzards (Buteo hemilasius Temminck et Schlegel) and Eurasian Eagle Owls (Bubo bubo L. subsp. Hemachalana Hume) were studied in an alpine meadow (3250 m a.s.l.) on Qinghai-Tibet Plateau, China. Root voles Microtus oeconomus Pallas, plateau pikas Ochotona curzoniae Hodgson, Gansu pikas O. cansus Lyon and plateau zokors Myospalax baileyi Thomas were the main diet components of Upland Buzzards as identified through the pellets analysis with the frequency of 57, 20, 19 and 4%, respectively. The four rodent species also were the main diet components of Eurasian Eagle Owls basing on the pellets and prey leftovers analysis with the frequency of 53, 26, 13 and 5%, respectively. The food niche breadth indexes of Upland Buzzards and Eurasian Eagle Owls were 1.60 and 1.77 respectively (higher value of the index means the food niche of the raptor is broader), and the diet overlap index of the two raptors was larger (C-ue = 0.90) (the index range from 0 - no overlap - to I - complete overlap). It means that the diets of Upland Buzzards and Eurasian Eagle Owls were similar (Two Related Samples Test, Z = -0.752, P = 0.452). The classical resource partitioning theory can not explain the coexistence of Upland Buzzards and Eurasian Eagle Owls in alpine meadows of Qinghai-Tibet Plateau. However, differences in body size, predation mode and activity rhythm between Upland Buzzards and Eurasian Eagle Owls may explain the coexistence of these two sympatric raptors.

Analysis of diets of upland buzzards using stable carbon and nitrogen isotopes

We measured the stable carbon and nitrogen isotope ratios for muscles of the upland buzzards (Buteo hemilasius) and their potential food sources, plateau pikas (Ochotona curzoniae), Qinghai voles (Lasiopodomys fuscus), plateau zokors (Myospalax fontanierii), and several passerine bird species at the alpine meadow in Maduo county, Guoluo prefecture of Qinghai province, People's Republic of China, to provide diet information of upland buzzards, highlighting different diet composition of upland buzzards exposed to different locations. The results demonstrated that stable carbon isotope ratios of upland buzzards, passerine birds, plateau pikas, plateau zokors, and Qinghai voles were -24.42 +/- 0.25parts per thousand, -22.89 +/- 1.48parts per thousand, -25.30 +/- 1.47parts per thousand, -25.78 +/- 0.22parts per thousand, and -25.41 +/- 0.01parts per thousand, respectively, and stable nitrogen isotope ratios were 7.89 +/- 0.38parts per thousand, 8.37 +/- 2.05parts per thousand, 5.83 +/- 1.10parts per thousand, 5.23 +/- 0.34parts per thousand, and 8.86 +/- 0.06parts per thousand, respectively. Fractionation of stable carbon and nitrogen isotope ratios between upland buzzards and their food were 1.03parts per thousand and 2.11parts per thousand, respectively. Based on mass balance principle of stable isotopes and the Euclidean distance mixing model, upland buzzards depended mainly on plateau pikas as food (74.56%). Plateau zokors, Qinghai voles, and passerine birds only contributed a small proportion (25.44%) to diets of upland buzzards. The results were closely accordant with analyses of stomach contents and food pellets, which firmly supported the feasibility of using stable carbon and nitrogen isotope ratios to investigate diet information of upland buzzards. Another study based on stable carbon isotopes showed that upland buzzards living in the Haibei prefecture (another prefecture located in the southeast Qinghai province) mainly preyed on passerine birds (64.96% or more) as food supply. We were alarmed by the preliminary results that widespread poisoning activities of small mammals could reshape the food composition of upland buzzards, influencing the stability and sustainability of the alpine meadow. Bio-control on rodent pests should be carried out rather than the chemical measures.

Stable carbon isotope analyses show dominance of C3 grasses in the feed selected by small herbivores at the alpine meadow at the Tibetan Plateau

Muscle samples were collected from small herbivorous mammals (Ochotona curzoniae, Microtus oecnomus, Myospalax fontanierii and Lepus oiostolus) at the alpine meadow ecosystem at the Tibetan Plateau in order to address variability in stable carbon isotope composition. Stable carbon isotope values of muscles remain steady and show no significant variations (-25.72 to -27.04 parts per thousand) among the four small mammal species. Based on the mass balance theory of stable isotopes, it is proposed that small herbivorous mammals mainly (or totally) rely on C3 grasses as food supply, and there is few or no distribution of C4 grasses at the ecosystem. The results reflect our previous study on the isotope patterns of plant species. Thus, stable carbon isotope analysis of muscles provides a method to address dietary selection and dietary variability in herbivores. In addition, stable carbon isotopic analyses can be used to address changes in vegetation distributions in ecosystem and paleovegetaion and paleoclimate.

Age-related development of a refractive index plateau in the human lens : evidence for a distinct nucleus

The human lens comprises two distinct regions in which the refractive index changes at different rates. The periphery contains a rapidly increasing refractive index gradient, which becomes steeper with age. The inner region contains a shallow gradient, which flattens with age, due to formation of a central plateau, of RI = 1.418, which reaches a maximum size of 7.0 �� 3.05 mm around age 60 years. Formation of the plateau can be attributed to compression of fibre cells generated in prenatal life. Present in prenatal but not in postnatal fibre cells, ��-crystallin may play a role in limiting nuclear cell compression.

Engaging with the Bailey Review : blogging, academia and authenticity

This article reproduces and discusses a series of blog posts posted by academics in anticipation of the report on commercialisation, sexualisation and childhood, 'Letting Children Be Children' by Reg Bailey for the UK Department of Education in June 2011. The article discusses the difficulty of 'translating' scholarly work for the public in a context where 'impact' is increasingly important and the challenges that academics face in finding new ways of speaking about sex in public.

Death in the Bolivian High Plateau : Burials and Tiwanaku Society

My Ph.D. dissertation presents a multi-disciplinary analysis of the mortuary practices of the Tiwanaku culture of the Bolivian high plateau, situated at an altitude of c. 3800 m above sea level. The Tiwanaku State (c. AD 500-1150) was one of the most important pre-Inca civilisations of the South Central Andes. The book begins with a brief introductory chapter. In chapter 2 I discuss methodological and theoretical developments in archaeological mortuary studies from the late 1960s until the turn of the millennium. I am especially interested in the issue how archaeological burial data can be used to draw inferences on the social structure of prehistoric societies. Chapter 3 deals with the early historic sources written in the 16th and 17th centuries, following the Spanish Conquest of the Incas. In particular, I review information on how the Incas manifested status differences between and within social classes and what kinds of burial treatments they applied. In chapter 4 I compare the Inca case with 20th century ethnographic data on the Aymara Indians of the Bolivian high plateau. Even if Christianity has affected virtually every level of Aymara religion, surprisingly many traditional features can still be observed in present day Aymara mortuary ceremonies. The archaeological part of my book begins with chapter 5, which is an introduction into Tiwanaku archaeology. In the next chapter, I present an overview of previously reported Tiwanaku cemeteries and burials. Chapter 7 deals with my own excavations at the Late Tiwanaku/early post-Tiwanaku cemetery site of Tiraska, located on the south-eastern shore of Lake Titicaca. During the 1998, 2002, and 2003 field seasons, a total of 32 burials were investigated at Tiraska. The great majority of these were subterranean stone-lined tombs, each containing the skeletal remains of 1 individual and 1-2 ceramic vessels. Nine burials have been radiocarbon dated, the dates in question indicating that the cemetery was in use from the 10th until the 13th century AD. In chapter 8 I point out that considerable regional and/or ethnic differences can be noted between studied Tiwanaku cemetery sites. Because of the mentioned differences, and a general lack of securely dated burial contexts, I feel that at present we can do no better than to classify most studied Tiwanaku burials into three broad categories: (1) elite and/or priests, (2) "commoners", and (3) sacrificial victims and/or slaves and/or prisoners of war. On the basis of such indicators as monumental architecture and occupational specialisation we would expect to find considerable status-related differences in tomb size, grave goods, etc. among the Tiwanaku. Interestingly, however, such variation is rather modest, and the Tiwanaku seem to have been a lot less interested in expending considerable labour and resources in burial facilities than their pre-Columbian contemporaries of many parts of the Central Andes.