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Miners
Kinds of Miners Selected AbstractsSex-biased hatching sequences in the cooperatively breeding Noisy MinerJOURNAL OF AVIAN BIOLOGY, Issue 3 2001Kathryn E. Arnold The Noisy Miner Manorina melanocephala (Meliphagidae) is a cooperatively breeding bird species in which sons often remain on their natal home ranges and help one or both of their parents. In a population of Noisy Miners in SE Queensland, Australia, a molecular technique was used to explore adult and offspring sex ratios, and also hatching sequences. Among the adult population, there were 2.31 males for every female, and roughly 99% of helping was performed by males. At hatching and fledging, the population sex ratio was even, with exactly 57 males and 57 females. However, in 17 out of 18 broods the first egg to hatch was male. First-hatched males were significantly larger and heavier than their sisters just prior to fledging. Through their helping behaviour, large healthy sons could clearly enhance the future reproductive success of parents, and benefit the entire group. Sex-biased hatching sequences could potentially provide cooperatively breeding birds with a subtle and precise way of varying investment in the helping sex. [source] Further characterization of human fetal osteoblastic hFOB 1.19 and hFOB/ER, cells: Bone formation in vivo and karyotype analysis using multicolor fluorescent in situ hybridizationJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2002M. Subramaniam Abstract We have previously generated an immortalized human fetal osteoblastic cell line (hFOB) using stably transfected temperature sensitive SV40 T-antigen (Harris et al. [1995a] J. Bone. Miner. Res. 10:178,1860). To characterize these cells for phenotypic/genotypic attributes desired for a good cell model system, we performed karyotype analysis by multicolor fluorescent in situ hybridization (M-FISH), their ability to form bone in vivo without developing cell transformation, and finally their ability to form extracellular matrix formation in vitro. The karyotype analysis of hFOB cells revealed structural or numeric anomalies involving 1,2 chromosomes. In contrast, the human osteosarcoma MG63 cells displayed multiple, and often complex, numeric, and structural abnormalities. Subcutaneous injection of hFOB cells in the presence of Matrigel into nude mice resulted in bone formation after 2,3 weeks. Electron microscopic analysis of the extracellular matrix deposited by hFOB cells in culture revealed a parallel array of lightly banded fibrils typical of the fibrillar collagens such as type I and III. These results demonstrate that the hFOB cell line has minimal chromosome abnormalities, exhibit the matrix synthetic properties of differentiated osteoblasts, and are immortalized but non-transformed cell line. These hFOB cells thus appear to be an excellent model system for the study of osteoblast biology in vitro. J. Cell. Biochem. 87: 9,15, 2002. © 2002 Wiley-Liss, Inc. [source] Band-related leg injuries in an Australian passerine and their possible causesJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2006Kate Splittgerber ABSTRACT We examined the extent and causes of band-related leg injuries in an Australian passerine, the Bell Miner (Manorina melanophrys). Eight percent of banded birds exhibited leg injuries, and most were birds with two plastic color bands on a tarsus. Leg injuries typically followed the accumulation of shed tarsal scales under the color bands. Color bands used on Bell Miners were tighter on the tarsus than the metal band and also tighter than the color bands used on Superb Fairy-wrens (Malurus cyaneus), a commonly banded species with no reported leg injuries. The tendency for scales to accumulate under two plastic color bands appeared to be influenced by the diameter of a band relative to the size of a bird's tarsus (with looser bands less likely to cause accumulation) and the material used to make the band (with smoother surfaces less likely to cause accumulation). Celluloid color bands had rougher internal surfaces than either Darvic or metal bands. In addition, both celluloid and Darvic color bands generated static electricity capable of attracting tarsal scales. Scales that accumulated under bands provided an environment where potentially harmful fungi became established, potentially contributing to the severity of leg injuries. Our results suggest that, when selecting an appropriate band size for a bird, the diameter of the tarsus at its midpoint should occupy only between 60% and 65% of the internal diameter of the band and, when possible, a single, bicolored, anodized aluminum alloy band should be used instead of multiple plastic color bands. SINOPSIS Examinamos la causa y la extensión de lesiones en las patas causadas por anillas en Manorina melanophrys, en Australia. Un 8% de las aves mostraron lesiones en las patas, la mayoría aves con dos anillas plásticas. Las lesiones causaron la acumulación de escamas tarsales mudadas, bajo la anilla. Se encontraron que las anillas plásticas ejercían mas presión o estaban más ajustadas que las anillas de metal y que estaban más apretadas que en Malurus cyaneus, una especie comúnmente anillada y en donde no encontramos lesiones. La tendencia de acumulación de escamas bajo las dos anillas plásticas, parece ser influenciada por el diámetro de la anilla, con respecto al grosor del tarso del ave y del material con que estuvo echo la anilla. Encontramos que las anillas de celuloide tienen una superficie interna más áspera que las anillas de metal. Además, ambos tipos de anillas, generan estática capaz de atraer las escama de la pata. Las partículas de escama que se acumulan bajo una anilla proveen de una buena base para que se crezcan hongos, que contribuyen a la gravedad de la lesión en la pata. Sugerimos que se deben seleccionar anillas apropiadas en tamaño en donde el diámetro del tarso en la parte media de la pata, ocupe entre el 60,65% del diámetro interno de la anilla. También, que cuando sea posible, se utilice una sola anilla de metal pintada con dos colores, en vez de dos anillas plásticas. [source] Rushing for Gold: Mobility and Small-Scale Mining in East AfricaDEVELOPMENT AND CHANGE, Issue 2 2009Jesper Bosse Jønsson ABSTRACT African rural dwellers have faced depressed economic prospects for several decades. Now, in a number of mineral-rich countries, multiple discoveries of gold and precious stones have attracted large numbers of prospective small-scale miners. While their ,rush' to, and activities within, mining sites are increasingly being noted, there is little analysis of miners' mobility patterns and material outcomes. In this article, on the basis of a sample survey and interviews at two gold-mining sites in Tanzania, we probe when and why miners leave one site in favour of another. Our findings indicate that movement is often ,rushed' but rarely rash. Whereas movement to the first site may be an adventure, movement to subsequent sites is calculated with knowledge of the many risks entailed. Miners spend considerable time at each site before migrating onwards. Those with the highest site mobility tend to be more affluent than the others, suggesting that movement can be rewarding for those willing to ,try their luck' with the hard work and social networking demands of mining another site. [source] Predators, parasitoids and pathogens: species richness, trophic generality and body sizes in a natural food webJOURNAL OF ANIMAL ECOLOGY, Issue 1 2000J. Memmott Summary 1.,A food web is presented which describes trophic interactions among the herbivores, parasitoids, predators and pathogens associated with broom, Cytisus scoparius (L.) Link. The data come from published work on the community at a single site. The web comprises a total of 154 taxa: one plant, 19 herbivores, 66 parasitoids, 60 predators, five omnivores and three pathogens. There are 370 trophic links between these taxa in the web. The taxa form 82 functionally distinct groups, called trophic species. 2.,Predators consumed significantly more species than did parasitoids: a median of two prey species per species of predator (range = 1,9), compared to a median of one host species per species of parasitoid (range = 1,4). Significant differences in the number of species consumed were also found among the five predator groups: birds (median = 4), spiders (median = 5), Coleoptera (median = 1), Diptera (median = 2) and Hemiptera (median = 7). 3.,Vulnerability, measured by numbers of consumer species, was significantly affected by the herbivores' feeding styles: externally feeding herbivores were most vulnerable and the concealed herbivores were least vulnerable. Miners were vulnerable to the most parasitoid species and externally feeding herbivores were the most vulnerable to predators. 4.,Resource species had a median vulnerability of 13 consumer species, a figure far higher than that in most published food webs. No significant relationship was found between species' vulnerability to predators and vulnerability to parasitoids. However, there was a strong negative relationship between the percentage mortality due to predation and percentage mortality due to parasitism. 5.,The broom food web contains nine orders of insects, a figure higher than previously recorded. The web also contains vertebrates, arachnids, bacteria and fungi. Most of the interactions between the orders were weak. Connectance was calculated for the complete web, the parasitoid sub-web and the predator sub-web. The connectance of the predator sub-web, a value of 0·0364, was more than an order of magnitude larger than the connectance of the entire web (0·0156) or the parasitoid sub-web (0·018). 6.,The body lengths of 52 species in the food web were estimated from field guides or museum specimens. Larger predators consumed smaller prey in 93% of predator,prey interactions. Smaller parasitoids consumed larger hosts in 79% of parasitoid,host interactions. Parasitoids were significantly smaller than predators. 7.,The 52 species were arranged in order of increasing body length along the columns and down the rows of a food web matrix. The predator sub-web was predominantly upper triangular with 8% of non-zero elements falling below the leading diagonal. The parasitoid sub-web was predominantly lower triangular with 21% non-zero elements falling above the leading diagonal. The entire web contains entries both above and below the main diagonal and thus violates a central assumption of the cascade model. [source] Sex-biased hatching sequences in the cooperatively breeding Noisy MinerJOURNAL OF AVIAN BIOLOGY, Issue 3 2001Kathryn E. Arnold The Noisy Miner Manorina melanocephala (Meliphagidae) is a cooperatively breeding bird species in which sons often remain on their natal home ranges and help one or both of their parents. In a population of Noisy Miners in SE Queensland, Australia, a molecular technique was used to explore adult and offspring sex ratios, and also hatching sequences. Among the adult population, there were 2.31 males for every female, and roughly 99% of helping was performed by males. At hatching and fledging, the population sex ratio was even, with exactly 57 males and 57 females. However, in 17 out of 18 broods the first egg to hatch was male. First-hatched males were significantly larger and heavier than their sisters just prior to fledging. Through their helping behaviour, large healthy sons could clearly enhance the future reproductive success of parents, and benefit the entire group. Sex-biased hatching sequences could potentially provide cooperatively breeding birds with a subtle and precise way of varying investment in the helping sex. [source] Band-related leg injuries in an Australian passerine and their possible causesJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2006Kate Splittgerber ABSTRACT We examined the extent and causes of band-related leg injuries in an Australian passerine, the Bell Miner (Manorina melanophrys). Eight percent of banded birds exhibited leg injuries, and most were birds with two plastic color bands on a tarsus. Leg injuries typically followed the accumulation of shed tarsal scales under the color bands. Color bands used on Bell Miners were tighter on the tarsus than the metal band and also tighter than the color bands used on Superb Fairy-wrens (Malurus cyaneus), a commonly banded species with no reported leg injuries. The tendency for scales to accumulate under two plastic color bands appeared to be influenced by the diameter of a band relative to the size of a bird's tarsus (with looser bands less likely to cause accumulation) and the material used to make the band (with smoother surfaces less likely to cause accumulation). Celluloid color bands had rougher internal surfaces than either Darvic or metal bands. In addition, both celluloid and Darvic color bands generated static electricity capable of attracting tarsal scales. Scales that accumulated under bands provided an environment where potentially harmful fungi became established, potentially contributing to the severity of leg injuries. Our results suggest that, when selecting an appropriate band size for a bird, the diameter of the tarsus at its midpoint should occupy only between 60% and 65% of the internal diameter of the band and, when possible, a single, bicolored, anodized aluminum alloy band should be used instead of multiple plastic color bands. SINOPSIS Examinamos la causa y la extensión de lesiones en las patas causadas por anillas en Manorina melanophrys, en Australia. Un 8% de las aves mostraron lesiones en las patas, la mayoría aves con dos anillas plásticas. Las lesiones causaron la acumulación de escamas tarsales mudadas, bajo la anilla. Se encontraron que las anillas plásticas ejercían mas presión o estaban más ajustadas que las anillas de metal y que estaban más apretadas que en Malurus cyaneus, una especie comúnmente anillada y en donde no encontramos lesiones. La tendencia de acumulación de escamas bajo las dos anillas plásticas, parece ser influenciada por el diámetro de la anilla, con respecto al grosor del tarso del ave y del material con que estuvo echo la anilla. Encontramos que las anillas de celuloide tienen una superficie interna más áspera que las anillas de metal. Además, ambos tipos de anillas, generan estática capaz de atraer las escama de la pata. Las partículas de escama que se acumulan bajo una anilla proveen de una buena base para que se crezcan hongos, que contribuyen a la gravedad de la lesión en la pata. Sugerimos que se deben seleccionar anillas apropiadas en tamaño en donde el diámetro del tarso en la parte media de la pata, ocupe entre el 60,65% del diámetro interno de la anilla. También, que cuando sea posible, se utilice una sola anilla de metal pintada con dos colores, en vez de dos anillas plásticas. [source] Metal and non-metal miners' exposure to crystalline silica, 1998,2002AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2006James L. Weeks ScD Abstract Background Crystalline silica is well known to cause silicosis and other diseases. Exposure is common in the mining industry and consequently, the US Mine Safety and Health Administration (MSHA) evaluates miners exposure to silica to determine compliance with its exposure limit. Methods MSHA exposure measurements were obtained for the 5-year period from 1998 to 2002 and average exposure was calculated classified by occupation and by mine. Evaluation criteria were whether average values exceeded MSHA's permissible exposure limit or the limit recommended by the National Institute for Occupational Safety and Health (NIOSH), whether there was a risk of exposure to freshly fractured silica, and whether there was a risk of a high rate of exposure to silica. Results Miners in certain jobs are exposed to silica above permissible and recommended exposure limits. Some miners may also be exposed at a high rate or to freshly fractured silica. Conclusions Known dust control methods should be implemented and regular medical surveillance should be provided. Am. J. Ind. Med. 49:523,534, 2006. © 2006 Wiley-Liss, Inc. [source] Nestedness in fragmented landscapes: birds of the box-ironbark forests of south-eastern AustraliaECOGRAPHY, Issue 6 2002Ralph Mac Nally Nestedness in biota as a function of species richness , biota of depauperate assemblages being non-random subsets of richer biotas , has been widely documented in recent years (see Wright et al. 1998, Oecologia 113: 1,20). Ordering sites by richness maximizes nestedness indices; however, ordering by other criteria such as area or isolation may be more ecologically interpretable. We surveyed birds in true fragments (35 in all), and in "reference areas" in large extant forest blocks (30 locations), of the same range of areas (10, 20, 40, 80 ha). The avifauna was divided into "bush birds", species dependent on forest and woodland, and "open country" species. We looked at nestedness in four data sets: "bush birds" in fragments and reference areas, and "all birds" in fragments and in reference areas. All data sets were significantly nested. Ordering by area in all cases was not significantly less nested than ordering by richness. Ordering by area in fragments was significantly greater than in reference areas, but the differences in standardized nestedness indices were small (<15%). We identified those birds that had distributions among fragments that conformed strongly with area, those that were more randomly distributed and some species that were more likely to occupy the smallest fragments. Among the latter was a hyperaggressive, invasive, colonial native species (noisy miner Manorina melanocephala). A suite of small, insectivorous birds were more likely to strongly conform with expected distributions in relation to area, which was consistent with observations of their vulnerability to the effects of the noisy miner in smaller fragments. [source] Structure and vertical stratification of plant galler,parasitoid food webs in two tropical forestsECOLOGICAL ENTOMOLOGY, Issue 3 2009MIGUEL R. PANIAGUA Abstract 1.,Networks of feeding interactions among insect herbivores and natural enemies such as parasitoids, describe the structure of these assemblages and may be critically linked to their dynamics and stability. The present paper describes the first quantitative study of parasitoids associated with gall-inducing insect assemblages in the tropics, and the first investigation of vertical stratification in quantitative food web structure. 2.,Galls and associated parasitoids were sampled in the understorey and canopy of Parque Natural Metropolitano in the Pacific forest, and in the understorey of San Lorenzo Protected Area in the Caribbean forest of Panama. Quantitative host,parasitoid food webs were constructed for each assemblage, including 34 gall maker species, 28 host plants, and 57 parasitoid species. 3.,Species richness was higher in the understorey for parasitoids, but higher in the canopy for gall makers. There was an almost complete turnover in gall maker and parasitoid assemblage composition between strata, and the few parasitoid species shared between strata were associated with the same host species. 4.,Most parasitoid species were host specific, and the few polyphagous parasitoid species were restricted to the understorey. 5.,These results suggest that, in contrast to better-studied leaf miner,parasitoid assemblages, the influence of apparent competition mediated by shared parasitoids as a structuring factor is likely to be minimal in the understorey and practically absent in the canopy, increasing the potential for coexistence of parasitoid species. 6.,High parasitoid beta diversity and high host specificity, particularly in the poorly studied canopy, indicate that tropical forests may be even more species rich in hymenopteran parasitoids than previously suspected. [source] A new stem-borer of the genus Bucculatrix (Lepidoptera: Bucculatricidae) from Japan, with description of the life historyENTOMOLOGICAL SCIENCE, Issue 1 2009Shigeki KOBAYASHI Abstract A new species of bucculaticid moth, Bucculatrix hamaboella sp. nov. (Host plant: Hibiscus hamabo, Malvaceae) is described from Wakayama Prefecture, Japan. The feeding habit of the new species is unique in that: (i) the young larva is a leaf miner forming a long red linear mine but in the later instars the larva becomes a stem borer; (ii) later instar larvae undergo double molts within a cocoonet (molting cocoon); and (iii) penultimate and final instars appear on the surface of the leaf as non-feeding stages. The external non-feeding larvae of B. hamaboella undergoing double molts within one cocoonet are considered to be an abbreviated form of the external feeding instars of other bucculatricids typically making first and second cocoonets, undergoing a single molt within each cocoonet. On the basis of morphological characters, this species is related to the species of Sections I and II (Host: Asteraceae) of Braun (1963), rather than to the species of Section VIII (Host: Malvaceae). [source] Products of the Imagination: Mining, Luxury, and the Romantic Artist in Heinrich von OfterdingenGERMAN LIFE AND LETTERS, Issue 1 2007Matt Erlin ABSTRACT Scholars have long been interested in the relationship between capitalism and early romantic aesthetics. The following investigation offers a fresh perspective on this topic through a reconsideration of the figure of the miner and the representation of mining in Friedrich von Hardenberg's Heinrich von Ofterdingen. Rather than elucidating this representation on the basis of general concepts like alienation and instrumental rationality, as has often been the case, the essay situates mining within the context of the wide-ranging late eighteenth- and early nineteenth-century debates about luxury. When contextualised along these lines, it becomes clear that Hardenberg's representation of mining is best understood as part of an effort to defend the legitimacy of literature, especially the still fragile legitimacy of the novel. Re-framing the representation of mining in the work in this way also necessitates a re-evaluation of other key aspects of the novel, most significantly, its negotiation with processes of economic modernisation and especially its stance toward an incipient consumer culture in which reading and literature play a paradigmatic role. [source] ,1-Antitrypsin deficiency presenting with panniculitis and incidental discovery of chronic obstructive pulmonary diseaseINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2007Gretchen Korver MD A 60-year-old man presented to the Emergency Department (ED) with large, painful, indurated plaques on the right thigh, left abdomen, left chest, and right chest, which began without any preceding trauma on the right thigh 3 weeks prior to presentation in the ED. He was initially treated with cefazolin 1 g three times daily as home infusions. When the lesions continued to progress, he was admitted to the hospital and placed on amoxicillin/clavulanate and vancomycin. He had a single episode of fever of 102°F, but his white blood cell count and differential remained normal. An initial biopsy showed a dermal inflammatory infiltrate composed primarily of neutrophils and eosinophils with rare flame figures in the dermis. There was minimal fat seen in this biopsy. A differential diagnosis of Wells or Sweet's syndrome was entertained, and he was placed on 60 mg/day prednisone with no resolution of his symptoms. The patient's past medical history included hypertension, hyperlipidemia, peripheral neuropathy, and hiatal hernia. His family history was significant for emphysema in both parents and coronary artery disease in his father. Both of his parents smoked cigarettes. His grandfather, who was a coal miner, also had emphysema. Whilst on antibiotics and prednisone, the plaques on the patient's right thigh, right abdomen, and left chest expanded and ulcerated, draining an oily liquid (Figs 1 and 2). An incisional biopsy was obtained from his thigh. Histopathology showed a septal and lobular panniculitis with fat necrosis, neutrophils, and histiocytes (Fig. 3). Special stains for organisms were negative. Tissue sent for bacterial and fungal culture had no growth. Amylase and lipase levels were normal. Rheumatoid factor, antinuclear antibody (ANA), antineutrophil cytoplasmic antibody (ANCA), cryoglobulins, and antiphospholipid antibodies were all normal. The ,1-antitrypsin level was low at 25 mg/dL (ref. 75,135). The ,1-antitrypsin phenotype was PiZZ. Figure 1. Indurated plaques on right chest and thigh and left chest Figure 2. Ulcerated plaques on left chest Figure 3. Septal and lobular panniculitis with fat necrosis. Hematoxylin and eosin ×10 The patient had a normal glucose-6-phosphate dehydrogenase level and was placed on dapsone 200 mg/day. The inflammation resolved and, over the course of several months, the involved areas healed with scarring. The patient denied any pulmonary complaints but, during his hospitalization, was found incidentally to have an oxygen saturation of 88% on room air. He was sent for evaluation by a pulmonologist, and pulmonary function tests revealed a mixed restrictive and obstructive pattern with a forced expiratory volume in 1 to forced vital capacity (FEV1/FVC) ratio of 63% of predicted. He had never smoked. He was placed on supplemental oxygen but, as his pulmonary disease has been stable, he has not been treated with intravenous antitrypsin inhibitor. [source] Regional climate modulates the canopy mosaic of favourable and risky microclimates for insectsJOURNAL OF ANIMAL ECOLOGY, Issue 3 2007SYLVAIN PINCEBOURDE Summary 1,One major gap in our ability to predict the impacts of climate change is a quantitative analysis of temperatures experienced by organisms under natural conditions. We developed a framework to describe and quantify the impacts of local climate on the mosaic of microclimates and physiological states of insects within tree canopies. This approach was applied to a leaf mining moth feeding on apple leaf tissues. 2,Canopy geometry was explicitly considered by mapping the 3D position and orientation of more than 26 000 leaves in an apple tree. Four published models for canopy radiation interception, energy budget of leaves and mines, body temperature and developmental rate of the leaf miner were integrated. Model predictions were compared with actual microclimate temperatures. The biophysical model accurately predicted temperature within mines at different positions within the tree crown. 3,Field temperature measurements indicated that leaf and mine temperature patterns differ according to the regional climatic conditions (cloudy or sunny) and depending on their location within the canopy. Mines in the sun can be warmer than those in the shade by several degrees and the heterogeneity of mine temperature was incremented by 120%, compared with that of leaf temperature. 4.,The integrated model was used to explore the impact of both warm and exceptionally hot climatic conditions recorded during a heat wave on the microclimate heterogeneity at canopy scale. During warm conditions, larvae in sunlight-exposed mines experienced nearly optimal growth conditions compared with those within shaded mines. The developmental rate was increased by almost 50% in the sunny microhabitat compared with the shaded location. Larvae, however, experienced optimal temperatures for their development inside shaded mines during extreme climatic conditions, whereas larvae in exposed mines were overheating, leading to major risks of mortality. 5,Tree canopies act as both magnifiers and reducers of the climatic regime experienced in open air outside canopies. Favourable and risky spots within the canopy do change as a function of the climatic conditions at the regional scale. The shifting nature of the mosaic of suitable and risky habitats may explain the observed uniform distribution of leaf miners within tree canopies. [source] Approaching risk assessment of complex disease development in horse chestnut trees: a chemical ecologist's perspectiveJOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2008A. B. Johne Abstract The chemo-ecological predispositions were investigated for the development of a complex disease on the basis of an insect,fungus mutualism using the system of horse chestnuts (Aesculus hippocastanum and Aesculus x carnea), the horse chestnut leaf miner (Cameraria ohridella) and the biotrophic powdery mildew (Erysiphe flexuosa). Both C. ohridella and E. flexuosa can appear on the same horse chestnut leaf tissue simultaneously. The olfactory detection of fungal infection by the insect, its ability to discriminate the potentially mutualistic fungus from other fungi and the impact of fungal infection on insect oviposition were examined. Gas chromatography coupled with mass spectroscopic and electroantennographic detection by C. ohridella (GC-MS/EAD) was used to assess the olfactory detection of fungal-infected A. hippocastanum and A. x carnea leaves by C. ohridella. Infection-related compounds, such as benzyl alcohol, dodecane, tridecane and methyl salicylate as well as fungus-related C8 compounds, are perceived by C. ohridella. The discrimination of E. flexuosa from another phytopathogenic fungus, such as Guignardia aesculi, is based primarily on the differing pattern of C8 compounds of these fungi. Oviposition on fungal-infected leaves of A. hippocastanum and leaves treated with fungal-related compounds showed that C. ohridella is able to respond to the modifications in the leaf volatile profiles of horse chestnuts caused by the different fungal infections. Thus, from the perception point of view, the necessary predispositions for the development of a close insect,fungus relation between the biotrophic fungus E. flexuosa and the leaf-mining insect C. ohridella are fulfilled. However, decreased oviposition on infected leaves does not enhance the selective contact between the species. As a consequence, an important predisposition for forming an insect,fungus mutualism is not fulfilled by these two species and, according to this approach, the risk of forming a complex disease can be assessed as low. [source] Explaining bird species composition and richness in eucalypt-dominated remnants in subhumid TasmaniaJOURNAL OF BIOGEOGRAPHY, Issue 9 2003Michael A. MacDonald Abstract Aim To determine the factors influencing the distribution of birds in remnants in a fragmented agricultural landscape. Location Forty-seven eucalypt remnants and six sites in continuous forest in the subhumid Midlands region of Tasmania, Australia. Methods Sites were censused over a two-year period, and environmental data were collected for remnants. The avifauna of the sites was classified and ordinated. The abundances of bird species, and bird species composition, richness, abundance and diversity were related to environmental variables, using simple correlation and modelling. Results There were two distinct groups of sample sites, which sharply differed in species composition, richness, diversity and bird abundance, separated on the presence/absence of noisy miner (Manorina melanocephala Latham) colonies, remnant size, vegetation structural attributes and variables that reflected disturbance history. The approximate remnant size threshold for the change from one group to another was 20,30 ha. Remnant species richness and diversity were most strongly explained by remnant area and noisy miner abundance, with contributions from structural and isolation attributes in the second case. Segment richness was explained by precipitation, logging history and noisy miner abundance. Bird abundance was positively related to precipitation and negatively related to tree dieback. The 28 individual bird species models were highly individualistic, with vegetation structural variables, noisy miner abundance, climatic variables, variables related to isolation, area, variables related to floristics, disturbance variables, the nature of the matrix and remnant shape all being components in declining order of incidence. Age of the remnant did not relate to any of the dependent variables. Main conclusions Degraded and small remnants may have become more distinct in their avifaunal characteristics than might otherwise be the case, as a result of the establishment of colonies of an aggressive native bird, the noisy miner. The area, isolation and shape of remnants directly relate to the abundance of relatively few species, compared to vegetation attributes, climate and the abundance of the noisy miner. The nature of the matrix is important in the response of some species to fragmentation. [source] Quantitative trait locus mapping of resistance in apple to Cydia pomonella and Lyonetia clerkella and of two selected fruit traitsANNALS OF APPLIED BIOLOGY, Issue 3 2009S. Stoeckli Abstract Apple, Malus×domestica, is the most important fruit grown within the temperate zonobiome. It is attacked by both fruit-damaging and leaf-damaging lepidopteran pest insects, which require regular control such as the carpophagous codling moth, Cydia pomonella, or frequent control such as the phyllophagous apple leaf miner, Lyonetia clerkella. As many environmentally friendly pest control tactics are only effective at low levels of infestation, host plant resistance is a promising future component of integrated pest management systems, but knowledge is still lacking on such genetically based approaches against lepidopteran pests. The aim of the study was to identify molecular markers linked to C. pomonella and L. clerkella resistance or susceptibility in commercial apple as well as markers linked to selected fruit traits. The number of C. pomonella -infested fruits and the number of L. clerkella mines were quantified as measures of apple resistance or susceptibility to the studied moth species. Herbivore surveys on 160 apple genotypes, representing a segregating F1 cross of the apple cultivars ,Fiesta' and ,Discovery', were carried out during two consecutive years and at two sites in Switzerland. Broad-sense heritability was 29.9% (C. pomonella), 18.2% (L. clerkella), 21.9% (fruit number) and 16.6% (fruit diameter). A subsequent analysis identified a quantitative trait locus (QTL) associated to C. pomonella susceptibility on the Discovery linkage group 10. The closest marker to this QTL was the random amplified polymorphic marker Z19-350. No significant QTL was identified for resistance to L. clerkella. A putative QTL associated to fruit number was identified on Fiesta linkage group 12. The presented QTL associated with C. pomonella susceptibility and the putative QTL linked to fruit number may facilitate marker-assisted breeding of resistant apple cultivars with cropping traits desirable for optimal fruit production. [source] Non-lethal foraging by bell miners on a herbivorous insect: Potential implications for forest healthAUSTRAL ECOLOGY, Issue 4 2010KATHRYN M. HAYTHORPE Abstract Tree health is often negatively linked with the localized abundance of parasitic invertebrates. One group, the sap-sucking psyllid insects (Homoptera: Psyllidae) are well known for their negative impact upon vegetation, an impact that often culminates in the defoliation and even death of hosts. In Australia, psyllid-infested forest in poor health is also frequently occupied by a native honeyeater, the bell miner (Manorina melanophrys; Meliphagidae), so much so that the phenomenon has been dubbed ,bell miner-associated dieback' (BMAD). Bell miners are thought to be the causative agent behind BMAD, in part because the species may selectively forage only upon the outer covering (lerp) exuded by psyllid nymphs, leaving the insect underneath to continue parasitizing hosts. As bell miners also aggressively exclude all other avian psyllid predators from occupied areas, these behavioural traits may favour increases in psyllid populations. We examined bell miner foraging behaviour to determine if non-lethal foraging upon psyllid nymphs occurred more often than in a congener, the noisy miner (M. melanocephala; Meliphagidae). This was indeed the case, with bell miners significantly more likely to remove only the lerp covering during feeding, leaving the insect intact underneath. This arose from bell miners using their tongue to pry off the lerp cases, whereas noisy miners used their mandibles to snap at both the lerp and insect underneath. Furthermore, psyllids left behind following a bell miner foraging event were significantly more likely to be viable and regrow a lerp covering than those exposed by noisy miners. Together, this behaviour supports the theory that non-lethal foraging behaviour of bell miners may contribute to high psyllid abundance, consistent with the mechanisms by which BMAD is thought to develop. [source] Habitat preferences of the noisy miner (Manorina melanocephala) , a propensity for prime real estate?AUSTRAL ECOLOGY, Issue 3 2009JOANNE M. OLDLAND Abstract This study investigated habitat characteristics that have been postulated to influence the occurrence of noisy miners (Manorina melanocephala Family Meliphagidae). It builds on an earlier study that identified corners along remnant edges as important predictors of the presence of noisy miners in large blocks of remnant vegetation (>300 ha). Six habitat characteristics were recorded at 39 corner sites within the box-ironbark region of Victoria. We failed to detect any significant effect of the density of understorey vegetation on the likelihood of noisy miners occupying a site, but this might have been an artefact of prolonged drought conditions. The most powerful predictors of the presence of noisy miners at remnant corners were found to be soil type and the proportion of canopy trees at a site that were yellow gum (Eucalyptus leucoxylon), with noisy miners being associated with deeper, more fertile soils and higher proportions of yellow gums present. As yellow gum is a prolific and reliable nectar producer, the inherent productivity of a site might be more important in determining the attractiveness of a site to noisy miners than structural attributes like the presence or absence of an understorey. Noisy miners are sedentary colonial birds that occupy year-round territories, often at high densities. Sites capable of supporting such high density occupation year-round might be limited to the most productive sites within the landscape. This productivity hypothesis has potentially profound implications for other woodland avifauna, as noisy miners might be excluding other woodland birds from some of the most fertile components of the landscape; components that are already rare in the box-ironbark region due preferential clearing for agriculture at the time of settlement. [source] Rushing for Gold: Mobility and Small-Scale Mining in East AfricaDEVELOPMENT AND CHANGE, Issue 2 2009Jesper Bosse Jønsson ABSTRACT African rural dwellers have faced depressed economic prospects for several decades. Now, in a number of mineral-rich countries, multiple discoveries of gold and precious stones have attracted large numbers of prospective small-scale miners. While their ,rush' to, and activities within, mining sites are increasingly being noted, there is little analysis of miners' mobility patterns and material outcomes. In this article, on the basis of a sample survey and interviews at two gold-mining sites in Tanzania, we probe when and why miners leave one site in favour of another. Our findings indicate that movement is often ,rushed' but rarely rash. Whereas movement to the first site may be an adventure, movement to subsequent sites is calculated with knowledge of the many risks entailed. Miners spend considerable time at each site before migrating onwards. Those with the highest site mobility tend to be more affluent than the others, suggesting that movement can be rewarding for those willing to ,try their luck' with the hard work and social networking demands of mining another site. [source] Interannual changes in folivory and bird insectivory along a natural productivity gradient in northern Patagonian forestsECOGRAPHY, Issue 1 2004C. Noemi Mazía Trophic regulation models suggest that the magnitude of herbivory and predation (top-down forces) should vary predictably with habitat productivity. Theory also indicates that temporal abiotic variation and within-trophic level heterogeneity both affect trophic dynamics, but few studies addressed how these factors interact over broad-scale environmental gradients. Here we document herbivory from leaf-feeding insects along a natural rainfall/productivity gradient in Nothofagus pumilio forests of northern Patagonia, Argentina, and evaluate the impact of insectivorous birds on foliar damage experienced by tree saplings at each end of the gradient. The study ran over three years (1997,2000) comprising a severe drought (1998,1999), which allowed us to test how climatic events alter top-down forces. Foliar damage tended to increase towards the xeric, least productive forests. However, we found a predictable change of insect guild prevalence across the forest gradient. Leaf miners accounted for the greater damage recorded in xeric sites, whereas leaf chewers dominated in the more humid and productive forests. Interannual folivory patterns depended strongly on the feeding guild and forest site. Whereas leaf-miner damage decreased during the drought in xeric sites, chewer damage increased after the drought in the wettest site. Excluding birds did not affect leaf damage from miners, but generally increased chewer herbivory on hydric and xeric forest saplings. Indirect effects elicited by bird exclusion became most significant after the drought, when total folivory levels were higher. Thus, interannual abiotic heterogeneity markedly influenced the amount of folivory and strength of top-down control observed across the forest gradient. Moreover, our results suggest that spatial turnovers between major feeding guilds may need be considered to predict the dynamics of insect herbivory along environmental gradients. [source] Weak parasitoid-mediated apparent competition between two Phyllonorycter (Lepidoptera: Gracillariidae) leaf miner species on a deciduous oak Quercus dentataENTOMOLOGICAL SCIENCE, Issue 3 2009Takashi NAKAMURA Abstract Parasitoid assemblages and the rates of parasitism on tissue-feeding larvae of two Phyllonorycter leaf miner species, P. persimilis and P. leucocorona, were studied from the autumn generation in 2002 to the summer generation in 2005 to understand whether parasitoids mediate interactions between the two leaf miner species. Fourteen species of parasitoids emerged from P. persimilis and 11 emerged from P. leucocorona. The parasitism rate was high: 24.1,92.6% in P. persimilis and 58.9,81.7% in P. leucocorona. Thus, parasitism was a major mortality factor in the present Phyllonorycter species. The parasitoid composition was distinctly different between the two host species, although most parasitoids were able to parasitize both leaf miner species. The analysis based on the quantitative parasitoid overlap revealed that the present parasitoids could mediate interactions between the present leaf miner species, but their effects would be weak. This is attributable to parasitoid's preferential uses of either of the leaf miners as a host. [source] Trauma and amputations in 19th century miners from Kimberley, South AfricaINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2010A. E. Van der Merwe Abstract Trauma is the result of violent accidental or therapeutic events that cause physical or psychological injury. The frequencies and types of trauma within a population can give important information regarding their lifestyle as well as the quantity and quality of medical care available to them. The purpose of this study was to assess the incidence of trauma in the Gladstone sample population with regards to the presence of interpersonal violence a hazardous working environment strenuous working requirements and the availability of medical care. The individuals studied here were diamond miners from Kimberley dating to the late 19th century. A total of 107 well-preserved skeletons were excavated from unmarked graves after accidental discovery. This sample included 86 males 15 females and 6 individuals of unknown sex. The majority of individuals (71%) were between 19 and 45 years of age. The remains were most likely those of migrant mine workers of low socioeconomic status who had passed away at the local hospitals. All bones were visually assessed for macroscopic indications of traumatic bone alterations and compared to standard palaeopathological texts and photographs. A total of 27% (n,=,28) of the individuals in the sample presented with well-healed healing or perimortem fractures. Fractures to the skull encompassed 49% (n,=,20) of all the fractures that were observed. A total of six (6%) amputations were noted. Spondylolysis was observed in 7% (n,=,7) of the individuals within the sample and longstanding subluxation was noted in two individuals. The high incidences of cranial fractures within this population are suggestive of high levels of interpersonal violence while long bone fractures spondylolysis and evidence of longstanding subluxations are indicative of the strenuous work requirements and the high-risk environment to which these individuals were exposed. When considering the presence of well-reduced fractures and healed amputations it seems that adequate medical care was available to at least some members of this community. Copyright © 2009 John Wiley & Sons Ltd. This article was published online on 17 February 2009. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 3 November 2009. [source] Regional climate modulates the canopy mosaic of favourable and risky microclimates for insectsJOURNAL OF ANIMAL ECOLOGY, Issue 3 2007SYLVAIN PINCEBOURDE Summary 1,One major gap in our ability to predict the impacts of climate change is a quantitative analysis of temperatures experienced by organisms under natural conditions. We developed a framework to describe and quantify the impacts of local climate on the mosaic of microclimates and physiological states of insects within tree canopies. This approach was applied to a leaf mining moth feeding on apple leaf tissues. 2,Canopy geometry was explicitly considered by mapping the 3D position and orientation of more than 26 000 leaves in an apple tree. Four published models for canopy radiation interception, energy budget of leaves and mines, body temperature and developmental rate of the leaf miner were integrated. Model predictions were compared with actual microclimate temperatures. The biophysical model accurately predicted temperature within mines at different positions within the tree crown. 3,Field temperature measurements indicated that leaf and mine temperature patterns differ according to the regional climatic conditions (cloudy or sunny) and depending on their location within the canopy. Mines in the sun can be warmer than those in the shade by several degrees and the heterogeneity of mine temperature was incremented by 120%, compared with that of leaf temperature. 4.,The integrated model was used to explore the impact of both warm and exceptionally hot climatic conditions recorded during a heat wave on the microclimate heterogeneity at canopy scale. During warm conditions, larvae in sunlight-exposed mines experienced nearly optimal growth conditions compared with those within shaded mines. The developmental rate was increased by almost 50% in the sunny microhabitat compared with the shaded location. Larvae, however, experienced optimal temperatures for their development inside shaded mines during extreme climatic conditions, whereas larvae in exposed mines were overheating, leading to major risks of mortality. 5,Tree canopies act as both magnifiers and reducers of the climatic regime experienced in open air outside canopies. Favourable and risky spots within the canopy do change as a function of the climatic conditions at the regional scale. The shifting nature of the mosaic of suitable and risky habitats may explain the observed uniform distribution of leaf miners within tree canopies. [source] Variations in parasitism in sympatric populations of three invasive leaf minersJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2007S. Girardoz Abstract:, Parasitism was investigated in sympatric populations of three invasive gracillariid leaf miners in Europe, Cameraria ohridella, Phyllonorycter robiniella and Phyllonorycter platani to test the hypotheses that C. ohridella is less heavily parasitized by native parasitoids and attacked by fewer species than the two other invasive species. In all regions investigated, C. ohridella showed a lower parasitism rate, and its parasitoid complex was poorer in species than those of either Phyllonorycter spp. Comparisons were made between sympatric populations of C. ohridella on its main host tree, Aesculus hippocastanum, and an occasional host, Acer pseudoplatanus. Parasitism rates were similarly low and composed of the same parasitoid species on both trees. In contrast, a sympatric population of Phyllonorycter geniculella, a native species mining A. pseudoplatanus, was heavily parasitized by a totally different parasitoid complex. These results suggest that the low parasitism in C. ohridella by native polyphagous leaf miner parasitoids is due neither to its host tree, nor to a problem of synchronization between the phenology of the pest and that of its parasitoids. Instead, it probably results from the inability of the native parasitoids to locate, attack, or develop on a new host that does not have any native congener in Europe. [source] Hunting, disturbance and roost persistence of bats in caves at Ankarana, northern MadagascarAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009Scott G. Cardiff Abstract Surveys and monitoring of 37 caves in and around the Ankarana Special Reserve, northern Madagascar, yielded evidence of hunting of bats and potential disturbance of bats by miners and tourists, and colony counts for several bat species of potential conservation concern. Colony size decreased by 95% and 14% for a colony of Hipposideros commersoni and a colony of Eidolon dupreanum, respectively, when recent evidence of hunting occurred at those colonies and those declines are probably attributable to hunting. Evidence of hunting occurred commonly at the roosts of those species and most commonly at the roosts of Rousettus madagascariensis. Hunting of pteropodids was associated with high vulnerability of roosts to hunters, little forest buffer between the cave and open savannah and the absence of tombs in the cave. Roost sites of the hunted species persisted for at least several years and this regularity may facilitate hunting. This work supports the ranking of E. dupreanum, R. madagascariensis and H. commersoni as species of conservation concern. Managers should consider the impact of tourist visits on bats and of increasing access to caves for tourism. Conservation efforts for the hunted species should also seek to protect vulnerable and unprotected cave roosts. Résumé Des études et un suivi continu de 37 grottes dans la Réserve Spéciale d'Ankarana et dans les environs, dans le nord de Madagascar, ont permis de récolter des preuves de la chasse aux chauves-souris et de l'éventuel dérangement des chauves-souris par des mineurs et des touristes; et des comptes de colonies pour plusieurs espèces dont le statut de conservation pourrait être inquiétant. La taille des colonies avait baissé de 95% et de 14% respectivement pour Hipposideros commersoni et pour Eidolon dupreanum, lorsque des preuves récentes de chasse sont apparues dans ces colonies; ces déclins sont probablement dus à la chasse. Des preuves de chasse étaient réguliérement présentes aux dortoirs de ces espèces, et plus communes encore aux dortoirs de Rousettus madagascariensis. La chasse des ptéropodidés était associée à une grande vulnérabilité des dortoirs face aux chasseurs, à une petite zone forestière tampon entre la grotte et la savane ouverte, et à l'absence de tombes dans la grotte. Les sites de repos des espèces chassées existaient depuis plusieurs années au moins, et cette persistance pourrait faciliter la chasse. Ce travail soutient le classement de E. dupreanum, R. madagascariensis et H. commersoni parmi les espèces dont le statut de conservation est inquiétant. Les gestionnaires devraient considérer l'impact des visites de touristes sur les chauves-souris et de l'augmentation de l'accès aux grottes pour le tourisme. Les efforts de conservation des espèces chassées devraient aussi viser à protéger les dortoirs dans des grottes vulnérables et non protégées. [source] Agroforestry management affects coffee pests contingent on season and developmental stageAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2009A. Teodoro Abstract 1,Management of vegetational diversity in agroecosystems is a potentially regulating factor of pest population dynamics and may affect developmental stages in different ways. 2,We investigated the population dynamics of red spider mites, coffee leaf miners, and coffee berry borers in three management types of coffee agroforests: increasing plant diversity from a few shade tree species (simple-shade agroforests), intermediate-shade tree species (complex-shade agroforests) to high-shade tree species (abandoned coffee agroforests) in Ecuador. Furthermore, we studied how changes in agroforestry management affect population stage structure of each coffee pest. 3,Our results show that agroforestry management affected seasonal patterns of coffee pests in that higher densities of red spider mites were observed from August to December, coffee leaf miners from December to February, and coffee berry borers from May to July. Moreover, specific developmental stages of red spider mites, coffee leaf miners, and coffee berry borers differed in their responses to agroforestry management. During all stages, red spider mite reached higher densities in simple-shade agroforests compared with complex-shade and abandoned agroforests. Meanwhile, coffee leaf miner densities decreased from simple-shade to complex-shade and abandoned agroforests, but only for larvae, not pupae. Similarly, only coffee berry borer adults (but not eggs, larvae and pupae) demonstrated a response to agroforestry management. Environmental variables characterizing each agroforestry type proved to be important drivers of pest population densities in the field. 4,We emphasize the importance of considering seasonal differences and population structure while investigating arthropod responses to different habitat types because responses change with time and developmental stages. [source] Skills under threat: the case of HIV/AIDS in the mining industry in ZimbabweJOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 5 2006Caroline N. Matangi Abstract The Zimbabwe mining industry is currently battling to arrest further spread of the HIV/AIDS crisis in workplaces, especially its impact on labour productivity. Labour in the closed community of mines has been greatly susceptible to HIV/AIDS infection. The current AIDS incidence in the mine sites is estimated at a weighted average of 15,per,cent amongst miners, with the largest category of workers,the 30,39 years age group,also constituting the worst affected category. Given the current state of the country's economy and consequently its adverse impact on the lifestyle of miners, the pandemic is expected to increase. This paper builds on the work of the ILO (1995) involving a survey of 18 various firms/institutions. The survey was carried out in Zambia in order to assess the impact of HIV/AIDS on the productive labour force. The survey revealed that many of the firms are experiencing irregular work attendance, ,wasted' training as some of the trained workers are constantly ill or die, high medical bills, funeral costs and reduced productivity and profits. An analysis of data on the main causes of death in 1993 shows that at least 61.8,per,cent of deaths could be attributed to causes that are very closely related to HIV/AIDS complications. Based on points highlighted by respondents and analysis of symptoms suffered, it was observed that HIV/AIDS tended to affect most general workers (36.8,per,cent), followed by the lower management (30.9,per,cent) and the middle management (20.6,per,cent). Comparatively, 11.8,per,cent of the deaths in 1993 belonged to the top management. Although it is hard to appreciate the meaning of the figures without knowledge of the number of people in each category, it nevertheless helps to form a clear picture of the impact of HIV/AIDS on industry. This paper seeks to further investigate the impact of HIV/AIDS on the productive labour force, by focusing on one particular industry,mining,using a blend of research methods to collect the data. This paper examines the impact of HIV/AIDS on the productive labour force and management responses. It forms part of the findings of data gathered in 2001 in the mining industry in Zimbabwe, to examine factors affecting management responses to HIV/AIDS in the mine sites. Zimbabwe is a country with a complex historical legacy of mine labour. This phenomenon can largely be attributed to the production oriented nature of the mining industry. Mines focus mainly on mineral extraction and as a result the bulk of mine workers tend to be production workers whose skills have developed over long periods of time. Production workers on mines have a tradition of long-term employment. This phenomenon has meant that labour in the mines is hard to replace as a result of skills, especially tacit knowledge, acquired over many years. Thus while the recent closure of some gold mines, largely due to low commodity prices, has meant that more miners are available in the labour market, this situation has not necessarily eased the process of replacing labour lost to the HIV/AIDS epidemic, as certain skills are firm specific. Production workers are predominantly male with the bulk falling in the 35,39 years age group. Most mine workers reside in mine villages, a colonial legacy that ensured miners were close to the workplace. The village system is a system of housing labourers, which demonstrates capitalistic methods of controlling labour and minimising costs. Of significance in this study's background is how the village system has come to be viewed as a factor in the spread of HIV/AIDS in the mining communities, because of its ,closed' nature. It is against this complex historical backdrop that the paper turns to examine the impact of the HIV/AIDS pandemic on production workers and management responses to the crisis using the Resource Based View of the Firm model (RBV), one of the theories in the Strategic Human Resource Management (SHRM) tradition. RBV was chosen for this study out of many HRM models that exist, because this theory, in particular, explains why it is advantageous for sites to use their ,unique' firm based resources in order to achieve sustainable competitive advantage. Given this rationale it was, therefore, presumed that this theory would best apply in mines battling with the adverse impact of HIV/AIDS on productivity, especially in the light of the harsh national economic climate, which would likely place limitations on response mechanisms. Further, the issue of firm-specific skills was also taken into consideration as an important factor in the mines, limiting their ability to resort to external solutions. Thus, given these factors, RBV was deemed the most appropriate model. The study finds that the pandemic depresses labour productivity through a number of significant ways: increased rate of HIV/AIDS induced absenteeism gradual labour turnover as a result of AIDS induced morbidity; and consequently declining skills availability, particularly firm-specific skills. Maintaining labour productivity in the face of gradually diminishing skills and indisposed labour will be key to softening the adverse economic consequences of the pandemic in the mines. To reduce the threat to labour productivity, mines must find ways of utilising, to the maximum extent practicable, existing skills. Results indicate that a move towards the utilisation of existing miners is the most favoured response mechanism in most mines. Utilising existing miners enables mines from spending financial resources on avoidable recruitment and training and quite often mechanisation, which may not necessarily be compatible with the old infrastructure in certain mines. Copyright © 2006 John Wiley & Sons, Ltd. [source] In the Wake of Things: Speculating in and about Sapphires in Northern MadagascarAMERICAN ANTHROPOLOGIST, Issue 2 2004ANDREW WALSH ABSTRACT This article discusses the interrelatedness of two sorts of speculation undertaken by Malagasy sapphire miners and traders involved in the northern Malagasy sapphire trade: first, the speculating that these people do in sapphires, and, second, the speculating that they do about the uses to which sapphires are put by foreigners. Although Malagasy people involved in the local trade know a great deal about how sapphires might be profitably traded, most of them do not know why foreigners are so interested in these stones. Dubious of foreign traders' assurances that sapphires are used in the production of jewelry, they speculate a variety of alternate, secret uses for them. In this article, it is argued that these speculations emerge out of a variety of locally developed assumptions about how the sapphire trade works, and specifically, the significant roles that deception and knowledge differentials play in its operation. [source] Risk attitudes and mitigation among gold miners and others in the Suriname rainforestNATURAL RESOURCES FORUM, Issue 4 2003Marieke Heemskerk Abstract This article analyses the question: do attitudes towards risk influence participation in small-scale gold mining, a hazardous activity that generates uncertain income? This question is examined by measuring and comparing the risk attitudes of gold miners and non-mining community members in the rainforest of Suriname, South America. The author presents a multivariate model to predict the duration of work in mining areas as a function of risk tolerance, age, education, and household demographics. The results suggest that a greater tolerance to risk increases the duration of a person's mining career. However, attitudes explain only a fraction of the variation in occupational choices. Qualitative data suggest that these choices are primarily shaped by local barriers to human capital development and by national economic volatility. Given their marginal position in society and the multitude of mining risk mitigation strategies, it is questionable whether gold mining exposes Suriname forest peoples to greater risks than other subsistence alternatives. The author argues that sensitivity to local historical and cultural conditions would improve the efficiency of policies aimed at developing a more sustainable mining industry. By zooming in on the daily lives of miners, anthropology can complement macro-scale analyses and contribute to policy interventions in the small-scale mining sector. [source] | ||||||||||||||||||||||||||||||||||