Zinc deposits and related mineralization of the Burketown mineral field, including the world-class Century Deposit, Northern Australia: Fluid inclusion and stable isotope evidence for basin fluid sources

The stratiform Century Zn-Pb deposit and the discordant Zn-Pb lode deposits of the Burketown mineral field, northern Australia, host ore and gangue minerals with primary fluid inclusions that have not been affected by the Isan orogeny, thus providing a unique opportunity to investigate the nature of the ore-forming brines. All of the deposits are hosted in shales and siltstones belonging to the Isa superbasin and comprise sphalerite, pyrite, carbonate, quartz, galena, minor chalcopyrite, and minor illite. According to Pb model ages, the main ore stage of mineralization at Century formed at I575 Ma, some 20 m.y. after deposition of the host shale sequence. Microthermometry on undeformed, primary fluid inclusions hosted in porous sphalerite shows that the Zn at Century was transported to the deposit by a homogeneous, Ca2+- and Na+-bearing brine with a salinity of 21.6 wt percent NaCl equiv. delta D-fluid of the fluid inclusion water ranges from -89 to -83 per mil, consistent with a basinal brine that evolved from meteoric water. Fluid inclusion homogenization temperatures range between 74 degrees and 125 degrees C, which are lower than the 120 degrees to 160 degrees C range calculated from vitrinite reflectance and illite crystallinity data from the deposit. This discrepancy indicates that mineralization likely formed at 50 to 85 Mpa, corresponding to a depth of 1,900 to 3,100 m. Transgressive galena-sphalerite veins that cut stratiform mineralization at Century and breccia-filled quartz-dolomite-sphalerite-galena veins in the discordant Zn-Pb lodes have Pb model ages between 1575 and 1485 Ma. Raman spectroscopy and microthermometry reveal that the primary fluid inclusions in these veins contain Ca2+, Na+. but they have lower salinities between 23 and 10 wt percent NaCl equiv and higher delta D-fluid values ranging from -89 to -61 per mil than fluid inclusions in porous sphalerite from Century. Fluid inclusion water from sphalerite in one of the lode deposits has delta O-18(fluid) values of 1.6 and 2.4 per mil, indistinguishable from delta O-18(fluid) values between -0.3 to +7.4 per mil calculated from the isotopic composition of coexisting quartz, dolomite, and illite. The trend toward lower salinities and higher delta D-fluid values relative to the earlier mineralizing fluids is attributed to mixing between the fluid that formed Century and a seawater-derived fluid from a different source. Based on seismic data from the Lawn Hill platform and paragenetic and geochemical results from the Leichhardt River fault trough to the south, diagenetic aquifers in the Underlying Calvert superbasin appear to have been the most likely sources for the fluids that formed Century and the discordant lode deposits. Paragenetically late sphalerite and calcite cut sphalerite, quartz, and dolomite in the lode deposits and contain Na+-dominated fluid inclusions with much lower salinities than their older counterparts. The isotopic composition of calcite also indicates delta O-18(fluid) from 3.3 to 10.7 per mil, which is larger than the range obtained from synmineralization minerals, supporting the idea that a unique fluid source was involved. The absolute timing of this event is unclear, but a plethora of Pb model, K-Ar, and Ar-40/Ar-39 ages between 1440 and 1300 Ma indicate that a significant volume of fluid was mobilized at this time. The deposition of the Roper superbasin from ca. 1492 +/- 4 Ma suggests that these late veins formed from fluids that may have been derived from aquifers in overlying sediments of the Roper superbasin. Clear, buck, and drusy quartz in veins unrelated to any form of Pb-Zn mineralization record the last major fluid event in the Burketown mineral field and form distinct outcrops and ridges in the district. Fluid inclusions in these veins indicate formation from a low-salinity, 300 degrees +/- 80 degrees C fluid. Temperatures approaching 300 degrees C recorded in organic matter adjacent to faults and at sequence boundaries correspond to K-Ar ages spanning 1300 to 1100 Ma, which coincides with regional hydrothermal activity in the northern Lawn Hill platform and the emplacement of the Lakeview Dolerite at the time of assemblage of the Rodinia supercontinent.

Group diversity and group identification:the moderating role of diversity beliefs

Research on diversity in teams and organizations has revealed ambiguous results regarding the effects of group composition on workgroup performance. The categorization—elaboration model (van Knippenberg et al., 2004) accounts for this variety and proposes two different underlying processes. On the one hand diversity may bring about intergroup bias which leads to less group identification, which in turn is followed by more conflict and decreased workgroup performance. On the other hand, the information processing approach proposes positive effects of diversity because of a more elaborate processing of information brought about by a wider pool and variety of perspectives in more diverse groups. We propose that the former process is contingent on individual team members' beliefs that diversity is good or bad for achieving the team's aims. We predict that the relationship between subjective diversity and identification is more positive in ethnically diverse project teams when group members hold beliefs that are pro-diversity. Results of two longitudinal studies involving postgraduate students working in project teams confirm this hypothesis. Analyses further reveal that group identification is positively related to students' desire to stay in their groups and to their information elaboration. Finally, we found evidence for the expected moderated mediation model with indirect effects of subjective diversity on elaboration and the desire to stay, mediated through group identification, moderated by diversity beliefs.

Can you tell your clunis from your cubitus? A benchmark for functional imaging

Advances in functional brain imaging have allowed the development of new investigative techniques with clinical application—ranging from presurgical mapping of eloquent cortex to identifying cortical regions involved in religious experiences. Similarly a variety of methods are available to referring physicians, ranging from metabolic measures such as functional magnetic resonance imaging and positron emission tomography to measurements based on electrical activity such as electroencephalography and magnetoencephalography. However, there are no universal benchmarks by which to judge between these methods. In this study we attempt to develop a standard for functional localisation, based on the known functional organisation of somatosensory cortex. Studies have shown spatially distinct sites of brain activity in response to stimulation of various body parts. Generally these studies have focused on areas with large cortical representations, such as the index finger and face. We tested the limits of magnetoencephalography source localisation by stimulation of body parts, namely the clunis and the cubitus, that map to proximal and relatively poorly represented regions of somatosensory cortex.

Virtually isotropic transmission media with fiber Raman amplifier

We report a theoretical study and simulations of a novel fiber-spin tailoring technique to suppress the polarization impairments, namely polarization mode dispersion and polarization dependent gain (PDG), in fiber Raman amplifiers. Whereas use of depolarizer or multiplexing pump laser diodes with a final degree of pump polarization of 1% for periodically spun fiber results in PDG of about 0.3 dB, we demonstrate that application of just a two-section fiber (where the first part is short and has no spin, and the second one is periodically spun) can reduce the PDG to as low as below 0.1 dB.

Doubling of optical signals using triangular pulses

We propose a novel technique of doubling optical pulses in both frequency and time domains based on a combination of cross-phase modulation induced by a triangular pump pulse in a nonlinear Kerr medium and subsequent propagation in a dispersive medium.

Софтуерна среда за представяне на детерминирани динамични модели с възможност за статистика

Доклад по покана, поместен в сборника на Националната конференция "Образованието в информационното общество", Пловдив, октомври, 2006 г.

Az értékesítés és a marketing kapcsolatának piaci tájékozódásban betöltött szerepe és meghatározó tényezői (Role of the sales and marketing relationship in market orientation and its determining factors)

A szerző kutatásában azt vizsgálja, hogy az értékesítés területén dolgozó munkatársak piaci megfigyeléseit milyen mértékben képesek beépíteni a marketingvezetők a menedzsmentmunkába. Az értékesítési munkatársak piaci megfigyelései mindig naprakészek, ráadásul jelentősebb ráfordítás nélkül hozzáférhetők. A marketing- és a sales munkatársak közötti hagyományosan konfliktusokkal terhelt kapcsolat miatt azonban a vállalatok sokszor mégsem aknázzák ki a piaci tájékozódásnak ezt a lehetőségét. A nagyvállalati mintán empirikusan tesztelt modell szerint a menedzserek azon képessége, hogy felhasználják a vállalaton belül rendelkezésre álló információkat, alapvetően nem egyéni, hanem szervezeti képesség. Azok a menedzserek, akik olyan cégeknél dolgoznak, ahol a vállalati továbbképzések során más részlegek munkájába is bekapcsolódhatnak, nagyobb mértékben támaszkodnak a munkatársak piaci megfigyeléseire döntéseik meghozatala során. _____ The author examines in her research that to what extent marketing leaders can build market experience of sales employees into the management activity. Because of the traditionally problematic relationship between marketing and sales employees, companies do not exploit this opportunity of market orientation. According to the model tested on a big corporation sample, the capacity of managers to use information available within the company is basically not an individual but organisational capacity.

A láthatatlan kéz – szemelvények egy metafora történetéből (The invisible hand - extracts from the history of a metaphor)

A láthatatlan kéz Adam Smith nyomán a közgazdaságtan legismertebb metaforája lett, de jelentősége és értelmezése máig megosztja a közgazdászokat és eszmetörténészeket. Az interpretációk skálája rendkívül széles: mértékadó közgazdászok szerint ez a közgazdaságtan alapeszméje, míg mások Smith ironikus tréfájának vélik. A tanulmány áttekinti a láthatatlan kéz Smith előtti használatát teológiai, politikai és irodalmi szövegekben és a hozzájuk kapcsolódó interpretációkat. Ezt követően bemutatja, hogyan alkalmazta Smith a nevezetes kifejezést a merkantilista politika ironikus és paradox kritikájaként, és miként került a 19. század végétől e metafora a Smith-olvasatokban központi helyre, majd miként vált kérdésessé ez a felfogás a 2008-as válság nyomán. ____ Adam Smith's phrase the invisible hand has become the best-known metaphor in economics, yet both its interpretation and its relevance are hotly debated by economists and intellectual historians. The range of opinions is wide: several leading economists view it as the founding idea in economics and social studies, some historians see it as an ironic jest by Smith. The study surveys the different uses of the metaphor in theological, political and literary texts before Smith and reconstructs the "invisible hand" passage in The Wealth of Nations as an ironic and paradoxical critique of mercantilist policy. A vast literature has emerged since the late 19th century treating the metaphor in various way, ranging from the description and justification of free markets to the claim that it is a purely fictitious mechanism. The critical approach to it has become stronger since the great recession of 2008.

The braids of the virgin: Taino roots of the early cult of La Virgen de la Caridad del Cobre in Cuba

Since her discovery in Cuban waters in 1611, La Virgen de la Caridad del Cobre (The Virgin of Charity) has become the leading transnational religious symbol for Cubans. The oldest stories about the appearance of La Virgen in Cuba suggest the presence of Cuban Taino in the early years of her cult. Yet historians have minimized Taino influence when examining Cuba's sixteenth and seventeenth centuries, pivotal years in the cult's development. This thesis demonstrated the significant role of the Taino in the formation of the early cult of La Virgen de la Caridad del Cobre, by employing revisionist historiography to the years between 1492 and 1687, to better understand the demographics and religious culture of Eastern Cuba, where the cult originated. It also found specific contributions from Taino religious culture in the myths, beliefs, and material culture associated with the early cult of La Virgen. ^

Generational Differences in Work Attitudes: Evidence from the Hospitality Industry

Our understanding of employee attitudes and their impact on business outcomes has been further complicated in recent years by the newest cohort of service workers. Known as Generation Y (Gen Y), they appear to approach employment in a manner different to that of their predecessors. A review of the academic literature reveals little empirical evidence to support an appropriate understanding of the impact of such difference. This paper provides an overview of a large-scale study into generational differences in employee attitudes and reports on the preliminary data analysis of a survey of over 900 hospitality employees. The most important initial finding from the data analysis is that, on the whole, Gen Y employees have lower scores on those constructs that an organization should be attempting to maximize. Non-Gen Y employees are more satisfied with their jobs, more engaged and more affectively committed to the organization they work for than their Gen Y counterparts, amongst a range of other important constructs. Conversely, Gen Y employees display higher scores onthe constructs that an organization would want to minimize in its staff. Gen Y employees are more likely to be planning to quit their jobs, are more likely to perform poorly if their co-workers are doing so, and are also more likely to switch jobs for no particular reason. The discussion covers implications for management as well as directions for future research.

The Beacon, December 1, 2010

Vol. 24, Issue 42, 8 pages

The palatability of monosodium glutamate-enhanced vegetables as rated by Cuban-American older adults at a congregate meal site

The purpose of this study was to investigate the efficacy of using monosodium glutamate (MSG) as a means to increase palatability and prospective consumption of vegetables at a congregate meal site with Cuban-American clients. Thirty to 32 subjects participated in hedonic testing each day. MSG-enhanced (2 g MSG/500 g vegetable) and non-enhanced beets, string beans, carrots and peas were evaluated for palatability, preference and prospective consumption. Results showed that MSG significantly increased both palatability and prospective consumption of string beans (ps < .05) but not of the other 3 vegetables tested. These findings provide some evidence that MSG can be used to increase the palatability of vegetables served at congregate meal sites. However, these results suggest that older adults may not find the palatability of some vegetables to be improved by MSG and that optimal flavor enhancement cannot be achieved by adding the same amount of MSG to every vegetable.

Data on the biogeochemical cycle of methane in the ocean

Geological, mineralogical and microbiological aspects of the methane cycle in water and sediments of different areas in the oceans are under consideration in the monograph. Original and published estimations of formation- and oxidation rates of methane with use of radioisotope and isotopic methods are given. The role of aerobic and anaerobic microbial oxidation of methane in production of organic matter and in formation of authigenic carbonates is considered. Particular attention is paid to processes of methane transformation in areas of its intensive input to the water column from deep-sea hydrothermal sources, mud volcanoes, and cold methane seeps.