Double-consciousness pervades the workplace experiences of minority professionals. Prior research captures various manifestations of double-consciousness in the workplace, yet much of what we know comes from understanding the experiences of minority professionals in predominantly White workplaces. Inherent in conceptions of double-consciousness is the sense of twoness in one's self concept that arises from seeing oneself through the eyes of both the predominantly White profession and one's own racial community. In this study, we examine contrasts as well as commonalities in experiences of double-consciousness across different social contexts in the socialization of minority scientists-in-training. We draw from qualitative data collected from 64 individuals (including 39 underrepresented minority doctoral students, and 25 faculty, staff, and administrators) in science, technology, engineering, and mathematics (STEM) doctoral programs in both predominantly White and historically Black institutions to examine and compare the factors across different contexts that influence how minority scientists-in-training are able to express their emerging professional identity. Our findings reveal how minority scientists-in-training experience twoness as both a struggle and a strength, and we develop an inductive model of how different socializations influence the double-conscious professional self-expressions of minority scientists in training. 相似文献
Estimates of biodiversity change are essential for the management and conservation of ecosystems. Accurate estimates rely on selecting representative sites, but monitoring often focuses on sites of special interest. How such site-selection biases influence estimates of biodiversity change is largely unknown. Site-selection bias potentially occurs across four major sources of biodiversity data, decreasing in likelihood from citizen science, museums, national park monitoring, and academic research. We defined site-selection bias as a preference for sites that are either densely populated (i.e., abundance bias) or species rich (i.e., richness bias). We simulated biodiversity change in a virtual landscape and tracked the observed biodiversity at a sampled site. The site was selected either randomly or with a site-selection bias. We used a simple spatially resolved, individual-based model to predict the movement or dispersal of individuals in and out of the chosen sampling site. Site-selection bias exaggerated estimates of biodiversity loss in sites selected with a bias by on average 300–400% compared with randomly selected sites. Based on our simulations, site-selection bias resulted in positive trends being estimated as negative trends: richness increase was estimated as 0.1 in randomly selected sites, whereas sites selected with a bias showed a richness change of −0.1 to −0.2 on average. Thus, site-selection bias may falsely indicate decreases in biodiversity. We varied sampling design and characteristics of the species and found that site-selection biases were strongest in short time series, for small grains, organisms with low dispersal ability, large regional species pools, and strong spatial aggregation. Based on these findings, to minimize site-selection bias, we recommend use of systematic site-selection schemes; maximizing sampling area; calculating biodiversity measures cumulatively across plots; and use of biodiversity measures that are less sensitive to rare species, such as the effective number of species. Awareness of the potential impact of site-selection bias is needed for biodiversity monitoring, the design of new studies on biodiversity change, and the interpretation of existing data. 相似文献
The aim of this study is to analyze the effect of salinity on polycyclic aromatic hydrocarbons (PAHs) biodegradation, community structure and naphthalene dioxygenase gene (ndo) diversity of a halophilic bacterial consortium with the denaturing gradient gel electrophoresis (DGGE) approach. The consortium was developed from oil-contaminated saline soil after enrichment for six times, using phenanthrene as the substrate. The prominent species in the bacterial consortium at all salinities were identified as halophilic bacteria Halomonas, Alcanivorax, Marinobacter, Idiomarina, Martelella and uncultured bacteria. The predominant microbes gradually changed associating with the saline concentration fluctuations ranging from 0.1% to 25% (w/v). Two ndo alpha subunits were dominant at salinities ranging from 0.1% to 20%, while not been clearly detected at 25% salinity. Consistently, the biodegradation occurred at salinities ranging from 0.1% to 20%, while no at 25% salinity, suggesting the two ndo genes played an important role in the degradation. The phylogenetic analysis revealed that both of the two ndo alpha subunits were related to the classic nah-like gene from Pseudomonas stutzeri AN10 and Pseudomonas aeruginosa PaK1, while one with identity of about 82% and the other one with identity of 90% at amino acid sequence level. We concluded that salinity greatly affected halophilic bacterial community structure and also the functional genes which were more related to biodegradation.
Benthic communities on soft bottoms off Barcelona, at and around two main pollution sources, the mouth of the Besòs River and the outlet of the submarine pipeline draining wastewater and organic sludges from the wastewater treatment plant of Sant Adrià del Besòs, have been studied. Samples were obtained with a Van Veen grab from 36 stations covering a 100 km2 grid, between 10 and 70 m in depth. The effect of both pollution sources is clearly seen both at the species (the following macrofauna groups have been studied: Polychaeta, Mollusca, Echinodermata and Crustacea Decapoda) and community levels. The distribution of species and individuals numbers, species diversity and a pollution index, and of some selected (indicator) polychaeta species, all clearly define the degree of environmental degradation and the extent of the areas under the influence of the organic pollution. 相似文献
