Development of Purkinje cells in the ovine brain

Purkinje cells are involved in many vital functions within the body. Twenty ovine fetuses ranging from 2 to 5 months of gestation, two lambs in the first week after birth and three adult sheep were studied. Sections of the cerebellum were stained with haematoxylin and eosin, cresyl violet and Klüver-Barrera. This study indicates that Purkinje cells began to appear after the 15(th) week of gestation. There were varying degrees of development of Purkinje cells in different zones of the cerebellum. Our findings in sheep fetuses suggest that the maturation of Purkinje cells starts in the caudal regions of the cerebellum and that the process begins in the vermis before it does in the cerebellar hemispheres. The alignment of Purkinje cells was found to be very regular in the caudal regions of the cerebellum. A partial absence of Purkinje cells in the rostral regions of the cerebellum was observed in both sheep fetuses and adult sheep. In the first post-natal week, some ectopic Purkinje cells were found in the white matter of the cerebellum.     

Role of waterlogging-responsive genes in shaping interspecific differentiation between two sympatric oak species

Pedunculate (Quercus robur L.) and sessile oak (Quercus petreae Matt. Liebl.) are closely related species with a widely sympatric distribution in Europe. These two oak species are also known to display different ecological features, particularly related to their adaptation to soil waterlogging. Pedunculate oak grows in humid areas and can withstand high moisture content of the soil, whereas sessile oak requires drier soil with better drainage. The main goal of this study was to explore the role of gene expression contributing to differences in terms of waterlogging tolerance between these two species. We implemented a series of experiments aimed at evaluating whether differentially expressed genes between species are associated with their ecological preferences and underlie adaptive genetic divergence. Rooted cuttings of both species were grown in hydroponic conditions and subjected to gradual root hypoxia. White roots were sampled after 6, 12, 24 and 48 h. Real-time polymerase chain reaction (qPCR) was first used to monitor the expression of 10 known waterlogging-responsive genes, to identify discriminating sampling time points along the kinetics of hypoxia. Secondly, four subtractive suppressive hybridization libraries (sessile vs. pedunculate, pedunculate vs. sessile for early and late responses) were generated to isolate differentially expressed genes between species. A total of 2160 high-quality expressed sequence tags were obtained and annotated, and a subset of 45 genes were selected for qPCR analysis in a second independent factorial experimental design applying two stress durations per two species. Significant differences of gene expression between pedunculate and sessile oaks were detected, suggesting species-specific molecular strategies to respond to hypoxia. This study revealed that the ability of pedunculate oak to maintain glycolysis and fermentation under hypoxic conditions may help explain its tolerance to waterlogging.     

Testing fertilizer, gypsum, planting season and varieties of wild leek (Allium tricoccum) in forest farming system

Wild leek (Allium tricoccum) is an edible spring ephemeral of the eastern deciduous forests of North America that takes advantage of the short period of high light conditions between snowmelt and canopy closure to accumulate the carbon required to complete its annual growth and seed production. In Québec (Canada), this slow-growing species has been subjected to great harvesting pressure, which forced the provincial government to ban commercial harvest and sales in 1995. An illegal market has since developed and the plant is still under threat. Conservation of existing natural populations might be possible through commercial production of wild leek. To investigate this possibility, we set up plots in four sugar maple forest stands where different organic fertilizer and gypsum (0 or 3,000 kg ha^?1) applications were tested, together with two wild leek varieties, and bulb planting season. The two varieties, tricoccum and burdickii, despite morphological differences, are both suitable for cultivation. Planting bulbs in the spring seems more advantageous than in autumn, but these results will need to be confirmed. Fertilized plants exhibited better growth the year following transplantation than did non-fertilized plants. Belowground:aboveground biomass ratios indicated that plants receiving more fertilizer produced larger bulbs, but leaf size did not differ statistically. According to leaf nutrient analysis, fertilizers would need to be applied each year, whereas gypsum (as a calcium source) can be applied less frequently. Our results indicated a high potential for wild leek as a forest crop, at least when the bulbs are planted.     

Morphometric analyses of the body and the branches of the normal third interosseous muscle (suspensory ligament) in Standardbreds

The third interosseous muscle (suspensory ligament, TIOM) is composed of connective tissue (CT) with a variable proportion of muscle (MT) and adipose tissue (AT). The aim of our study is to quantify the CT, MT and AT within the body and the branches of right thoracic and pelvic limbs TIOM in sound horses to determine whether there are differences in CT, MT and AT between age, sex, limbs and levels. Right limbs from 11 sound horses were collected. Samples from 6 levels of the TIOM were embedded in paraffin or in Tissue‐Tek^®. Most of the paraffin sections were shredded. Using the cryosection, some artefacts appeared. Cryoprotection was carried out, which produced the best results. Hematoxylin–phloxine–saffron and Hematoxylin–eosin gave a good contrast of colours between the tissues observed allowing the use of an image analysis programme to calculate percentage of each tissue within the TIOM. The percentage of MT and AT decreased significantly (P < 0.0001), whereas the percentage of CT increased significantly (P < 0.0001) with age and when descending from the proximal to the distal level of the TIOM. The percentage of MT was significantly higher (P < 0.0001) in females than males, while the percentage of CT was significantly higher (P < 0.0001) in males than females. The percentage of AT was significantly higher (P = 0.0278) in pelvic limbs than in thoracic limbs. These results confirm the variation in tissue composition within the TIOM of sound horses.     

Effect of supplied phytosiderophore on 59Fe absorption and translocation in Fe-deficient barley grown hydroponically in low phosphorus media

Hydroponically grown barley plants ( Hordeum vulgare L. cv. Minorimugi) under iron-deficient (–Fe) and high phosphorus (P) conditions (500 µmol L⁻¹) showed Fe chlorosis and lower growth compared with plants grown in –Fe and low P conditions (50, 5 and 0.5 µmol L⁻¹). To understand the physiological role of P in regulating the growth of plants in –Fe medium, we carried out an Fe feeding experiment using four P levels (500, 50, 5 and 0.5 µmol L⁻¹) and phytosiderophores (PS), mugineic acid. Our results suggest that plants grown in a high P medium had higher absorption activity of ⁵⁹Fe compared with plants grown in low P media, irrespective of the presence or absence of added PS. Translocation of ⁵⁹Fe from roots to shoots was not affected by the P level. The relative translocation rate of ⁵⁹Fe increased with decreasing levels of P in the medium. In general, the addition of PS enhanced the absorption of ⁵⁹Fe and its translocation. Taken together these results suggest that the lower relative translocation rate of Fe in high P plants may be induced by the physiological inactivation of Fe in the roots, and the higher absorption activity of Fe in high P conditions possibly results from the response of barley plants to Fe deficiency.     

Does reintroduction stabilize the population of the critically endangered gharial (Gavialis gangeticus,Gavialidae) in Chitwan National Park,Nepal?

• 1 Despite conservation programmes (India 1975, Nepal 1978) gharial populations (Gavialis gangeticus) have declined over their entire distribution range. Information about the current status and main threats is needed to implement effective conservation measures.
• 2 This study presents a survey (2003/2004) of the largest Nepalese gharial population in the Chitwan National Park that has benefited from regular re‐introduction of young gharials since 1981.
• 3 Population size estimates fluctuate between 34 (2003) and 38 (2004). The reintroduction programme, although of limited success, has helped to maintain the gharial population.
• 4 Gharials bask preferentially in large sand banks, and these sites must be protected.
• 5 The main threats are from a dam that causes fish depletion and flushes gharials from the protected area, sand mining and grazing that destroy basking sites, fishing that causes food shortage, drift nets that kill gharial, and water pollution.
• 6 Improvement in the survival of reintroduced gharials is needed. Strict protection of preferred basking sites and prohibition of fishing in the main settling zones are the principal conservation measures while in the long term, education and participatory management by local people are also necessary. Copyright © 2010 John Wiley & Sons, Ltd.

     

Agriculture as an asset class: reshaping the South African farming sector

According to portfolio managers, agriculture in general, and farmland in particular, can be considered an emerging asset class. Specialized financial vehicles, such as private equity and mutual funds, are emerging and competing to attract potential investment in this asset class. In recent years, there has been significant development of such vehicles targeting South Africa’s farming sector. These innovations are led by a group of market intermediaries (e.g. asset managers or consultants) who endeavour to “re-shape” South African farmland as an opportunity for institutional investors. These “pioneers” engage in a multifaceted mediation process between global financial investors on one hand, and the South African agricultural sector on the other. Drawing upon an empirical study of such intermediaries in South Africa, this paper analyses the concrete mechanisms that facilitate this particular form of commodification. The paper presents and compares the intermediaries, giving particular attention to their structure, governance mechanisms and asset allocations within this “market in the making”. It describes how intermediaries develop different paths of asset valorization to unlock the “financial value” of South African farmlands (i.e. “liquifying”, standardizing, neutralizing, and depoliticizing agriculture as an asset). But, it also highlights some of the difficulties faced in the process of translating between international investors and local managers, questioning the “land-asset fiction” that is materializing through the subordination of farmland to the needs of financial society.