Ethnic identity and Chicano literature: How ethnicity affects reading and reading affects ethnic consciousness

This article interrogates the impact of readers’ ethnicity (Latino and non-Latino) on meanings crafted from Chicano literature. This article addresses the effect of Chicano literature on ethnic identity and worldview formation. The data source is participant observation and interviews with eighteen students in a college-level Chicano literature seminar in the United States. Latino students found that the literature spoke to their experience as Latinos, inciting a sense of membership in a community that merits inclusion in a college course. This connection with the literature transmuted into ethnic validation for nearly all Latino students. Non-Latinos, hindered from relating to the course content on an ethnic level, discovered alternate entryways into the texts that allowed for identification on other particular levels. Non-Latinos ascertained how ethnic distinctions partially shape human experience and that this understanding is critical to cross-cultural appreciation and empathy. Non-Latinos additionally perceived that a common humanity tunnels beneath ethnic difference.     

Low temperature constrains growth rates but not short-term ingestion rates of Antarctic ciliates

Low environmental temperature is a major factor affecting the feeding activities, growth rates, and growth efficiencies of metazooplankton, but these features are poorly characterized for most protistan species. Laboratory experiments were conducted to examine the growth and ingestion rates of cultured herbivorous Antarctic ciliates. Three ciliates fed several algal species individually at 0 °C exhibited uniformly low growth rates (<0.26 day^?1), but the algae varied substantially in their ability to support ciliate growth. Specific ingestion rate (prey biomass consumed per unit ciliate biomass per unit time) was strongly affected by ciliate physiological state (starved vs. actively growing). Starved cells ingested many more prey than cells in balanced growth during short-term (minutes-to-hours) experiment but did not grow faster, indicating temperature compensation of ingestion rate but not growth rate. Field experiments were also conducted in the Ross Sea, Antarctica, to characterize the feeding rates of ciliates in natural plankton assemblages. Specific ingestion rates of two dominant ciliates were an order of magnitude lower than rates reported for temperate ciliates, but estimated rates were strongly affected by prey abundance. Our data indicate that short-term ingestion rates of Antarctic ciliates were not constrained by low environmental temperature although overall growth rates were, indicating the need for caution when designing experiments to measure the ingestion rates of these species at low environmental temperature. We present evidence that artifacts arising from estimating ingestion in short-term experiments may lead to errors in estimating feeding impact and growth efficiencies that are particularly large for polar protists.     

Isolation and functional analysis of denitrifiers in an aquifer with high potential for denitrification

Aquifers are among the main freshwater sources. The Raigón aquifer is susceptible to contamination, mainly by nitrate and pesticides, such as atrazine, due to increasing agricultural activities in the area. The capacity of indigenous bacteria to attenuate nitrate contamination in different wells of this aquifer was assessed by measuring denitrification rates with either acetate plus succinate or nitrate amendments. Denitrification activity in nitrate-amended assays was significantly higher than in unamended assays, particularly in groundwater from wells where nitrate concentration was 33.5 mg L⁻¹ or lower. Furthermore, groundwater denitrifiers capable of using acetate or succinate as electron donors were isolated, identified by 16S rRNA gene sequencing and evaluated for functional denitrification genes (nirS, nirK and nosZ). Phylogenetic affiliation of 54 isolates showed that all members belonged to nine different genera within the Proteobacteria (Bosea, Ochrobactrum, Azospira, Zoogloea, Acidovorax, Achromobacter, Vogesella, Stenotrophomonas and Pseudomonas). In addition, isolate AR28 that clustered separately from validly described species could potentially belong to a new genus. The majority of the isolates were related to species belonging to previously reported denitrifying genera. However, the phylogeny of the nirS and nosZ genes revealed new sequences of these functional genes. To our knowledge, this is the first isolation and sequencing of the nirS gene from the genus Vogesella, as well as the nosZ gene from the genera Acidovorax and Zoogloea. The results indicated that indigenous bacteria in the Raigón aquifer had the capacity to overcome high nitrate contamination and exhibited functional gene diversity.     

Evidence for developmental thermal acclimation in the damselfish, Pomacentrus moluccensis

Tropical species are predicted to have limited capacity for acclimation to global warming. This study investigated the potential for developmental thermal acclimation by the tropical damselfish Pomacentrus moluccensis to ocean temperatures predicted to occur over the next 50–100 years. Newly settled juveniles were reared for 4 months in four temperature treatments, consisting of the current-day summer average (28.5 °C) and up to 3 °C above the average (29.5, 30.5 and 31.5 °C). Resting metabolic rate (RMR) of fish reared at 29.5 and 31.5 °C was significantly higher than the control group reared at 28.5 °C. In contrast, RMR of fish reared at 30.5 °C was not significantly different from the control group, indicating these fish had acclimated to their rearing temperature. Furthermore, fish that developed in 30.5 and 31.5 °C exhibited an enhanced ability to deal with acute temperature increases. These findings illustrate that developmental acclimation may help coral reef fish cope with warming ocean temperatures.     

Artificial insemination in dromedary camels

Artificial insemination (AI) is an important technique in all domestic species to ensure rapid genetic progress. The use of AI has been reported in camelids although insemination trials are rare. This could be because of the difficulties involved in collecting as well as handling the semen due to the gelatinous nature of the seminal plasma. In addition, as all camelids are induced ovulators, the females need to be induced to ovulate before being inseminated.     

In vitro production of embryos in South American camelids

Studies in reproductive biotechnology techniques have been minimal in South American camelids (SAC). Complex reproductive characteristics of these species contribute to slow progress. Nevertheless, some techniques, such as in vitro fertilization, intracytoplasmic sperm injection and nuclear transfer have been applied and have produced advances in knowledge on embryo environment and in vitro conditions necessary for development. Embryo production may have a high impact in both domestic and wild camelids population. Studies addressed to improve in vitro embryo production and oocyte collection could be a potential key to develop IVF and embryo production as a routine procedure in camelids.     

Migration of Atlantic salmon smolts and post-smolts in the Rivière Saint-Jean, QC north shore from riverine to marine ecosystems

The characteristics of the Atlantic salmon (Salmo salar) smolt run of the Rivière Saint-Jean, Quebec, Canada, in 2009 and 2010 were determined using acoustic telemetry. Tagged smolts were tracked from freshwater release sites for 17 km, then through the estuary and for their entry into the Gulf of St. Lawrence. The smolt migration began in both years at water temperatures of 10 °C, but lasted twice as long in the cooler year. The smolts in 2009 crossed the river to ocean boundary faster than the smolts of 2010, despite being similar in size. Smolt speed over ground increased from the river to the estuary to the marine environment. Smolts migrated both during the day and the night, but most movements began near or just after sunset, with increasingly nocturnal movements in the ocean. Smolts crossed the estuary during ebbing tides and moved faster during the night than the day. The tide cycle also influenced estuarine smolt travelling rates, but only secondarily to the diel cycle.     

Multiphoton tomography visualizes collagen fibers in the tumor microenvironment that maintain cancer‐cell anchorage and shape

Second harmonic generation (SHG) multiphoton imaging can visualize fibrillar collagen in tissues. SHG has previously shown that fibrillar collagen is altered in various types of cancer. In the present study, in vivo high resolution SHG multi‐photon tomography in living mice was used to study the relationship between cancer cells and intratumor collagen fibrils. Using green fluorescent protein (GFP) to visualize cancer cells and SHG to image collagen, we demonstrated that collagen fibrils provide a scaffold for cancer cells to align themselves and acquire optimal shape. These results suggest a new paradigm for a stromal element of tumors: their role in maintaining anchorage and shape of cancer cells that may enable them to proliferate. J. Cell. Biochem. 114: 99–102, 2012. © 2012 Wiley Periodicals, Inc.