On the pathways feeding the H₂ production process in nutrient-replete, hypoxic conditions : commentary on the article 'Low oxygen levels contribute to improve photohydrogen production in mixotrophic non-stressed Chlamydomonas cultures', by Jurado-Oller et al., Biotechnology for Biofuels, published September 7, 2015; 8:149

Background: Under low O-2 concentration ( hypoxia) and low light, Chlamydomonas cells can produce H-2 gas in nutrient-replete conditions. This process is hindered by the presence of O-2, which inactivates the [FeFe]-hydrogenase enzyme responsible for H-2 gas production shifting algal cultures back to normal growth. The main pathways accounting for H-2 production in hypoxia are not entirely understood, as much as culture conditions setting the optimal redox state in the chloroplast supporting long-lasting H-2 production. The reducing power for H-2 production can be provided by photosystem II (PSII) and photofermentative processes during which proteins are degraded via yet unknown pathways. In hetero- or mixotrophic conditions, acetate respiration was proposed to indirectly contribute to H-2 evolution, although this pathway has not been described in detail. Main body: Recently, Jurado-Oller et al. (Biotechnol Biofuels 8: 149, 7) proposed that acetate respiration may substantially support H-2 production in nutrient-replete hypoxic conditions. Addition of low amounts of O-2 enhanced acetate respiration rate, particularly in the light, resulting in improved H-2 production. The authors surmised that acetate oxidation through the glyoxylate pathway generates intermediates such as succinate and malate, which would be in turn oxidized in the chloroplast generating FADH(2) and NADH. The latter would enter a PSII-independent pathway at the level of the plastoquinone pool, consistent with the light dependence of H-2 production. The authors concluded that the water-splitting activity of PSII has a minor role in H-2 evolution in nutrient-replete, mixotrophic cultures under hypoxia. However, their results with the PSII inhibitor DCMU also reveal that O-2 or acetate additions promoted acetate respiration over the usually dominant PSII-dependent pathway. The more oxidized state experienced by these cultures in combination with the relatively short experimental time prevented acclimation to hypoxia, thus precluding the PSII-dependent pathway from contributing to H-2 production. Conclusions: In Chlamydomonas, continuous H-2 gas evolution is expected once low O-2 partial pressure and optimal reducing conditions are set. Under nutrient-replete conditions, the electrogenic processes involved in H-2 photoproduction may rely on various electron transport pathways. Understanding how physiological conditions select for specific metabolic routes is key to achieve economic viability of this renewable energy source

Osmotic stress confers enhanced cell integrity to hydrostatic pressure but impairs growth in Alcanivorax borkumensis SK2

Alcanivorax is a hydrocarbonoclastic genus dominating oil spills worldwide. While its presence has been detected in oil-polluted seawaters, marine sediment and salt marshes under ambient pressure, its presence in deep-sea oil-contaminated environments is negligible. Recent laboratory studies highlighted the piezosensitive nature of some Alcanivorax species, whose growth yields are highly impacted by mild hydrostatic pressures (HPs). In the present study, osmotic stress was used as a tool to increase HP resistance in the type strain Alcanivorax borkumensis SK2. Control cultures grown under standard conditions of salinity and osmotic pressure with respect to seawater (35.6 ppt or 1136 mOsm kg(-1), respectively) were compared with cultures subjected to hypo- and hyperosmosis (330 and 1720 mOsm kg(-1), or 18 and 62 ppt in salinity, equivalent to brackish and brine waters, respectively), under atmospheric or increased HP (0.1 and 10 MPa). Osmotic stress had a remarkably positive impact on cell metabolic activity in terms of CO2 production (thus, oil bioremediation) and O-2 respiration under hyperosmosis, as acclimation to high salinity enhanced cell activity under 10 MPa by a factor of 10. Both osmotic shocks significantly enhanced cell protection by reducing membrane damage under HP, with cell integrities close to 100% under hyposmosis. The latter was likely due to intracellular water-reclamation as no trace of the piezolyte ectoine was found, contrary to hyperosmosis. Notably, ectoine production was equivalent at 0.1 MPa in hyperosmosis-acclimated cells and at 10 MPa under isosmotic conditions. While stimulating cell metabolism and enhancing cell integrity, osmotic stress had always a negative impact on culture growth and performance. No net growth was observed during 4-days incubation tests, and CO2:O-2 ratios and pH values indicated that culture performance in terms of hydrocarbon degradation was lowered by the effects of osmotic stress alone or combined with increased HP. These findings confirm the piezosensitive nature of A. borkumensis, which lacks proper resistance mechanisms to improve its metabolic efficiency under increased HP, thus explaining its limited role in oil-polluted deep-sea environments

Efficient molasses fermentation under high salinity by inocula of marine and terrestrial origin

BACKGROUND: Molasses is a dense and saline by-product of the sugar agroindustry. Its high organic content potentially fuels a myriad of renewable products of industrial interest. However, the biotechnological exploitation of molasses is mainly hampered by the high concentration of salts, an issue that is nowadays tackled through dilution. In the present study, the performance of microbial communities derived from marine sediment was compared to that of communities from a terrestrial environment (anaerobic digester sludge). The aim was to test whether adaptation to salinity represented an advantage for fermenting molasses into renewable chemicals such as volatile fatty acids (VFAs) although high sugar concentrations are uncommon to marine sediment, contrary to anaerobic digesters. RESULTS: Terrestrial and marine microbial communities were enriched in consecutive batches at different initial pH values (pH(i); either 6 or 7) and molasses dilutions (equivalent to organic loading rates (OLRs) of 1 or 5 g(COD) L(−1) d(−1)) to determine the best VFA production conditions. Marine communities were supplied with NaCl to maintain their native salinity. Due to molasses inherent salinity, terrestrial communities experienced conditions comparable to brackish or saline waters (20–47 mS cm(−1)), while marine conditions resembled brine waters (>47 mS cm(−1)). Enrichments at optimal conditions of OLR 5 g(COD) L(-1) d(-1) and pH(i) 7 were transferred into packed-bed biofilm reactors operated continuously. The reactors were first operated at 5 g(COD) L(-1) d(-1), which was later increased to OLR 10 g(COD) L(−1) d(−1). Terrestrial and marine reactors had different gas production and community structures but identical, remarkably high VFA bioconversion yields (above 85%) which were obtained with conductivities up to 90 mS cm(−1). COD-to-VFA conversion rates were comparable to the highest reported in literature while processing other organic leftovers at much lower salinities. CONCLUSIONS: Although salinity represents a major driver for microbial community structure, proper acclimation yielded highly efficient systems treating molasses, irrespective of the inoculum origin. Selection of equivalent pathways in communities derived from different environments suggests that culture conditions select for specific functionalities rather than microbial representatives. Mass balances, microbial community composition, and biochemical analysis indicate that biomass turnover rather than methanogenesis represents the main limitation to further increasing VFA production with molasses. This information is relevant to moving towards molasses fermentation to industrial application. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13068-017-0701-8) contains supplementary material, which is available to authorized users

Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivorax genus, namely A. jadensis KS_339 and A. dieselolei KS_293, which is known to rapidly grow after oil spills. Strains were subjected to atmospheric and mild pressure (0.1, 5 and 10?MPa, corresponding to a depth of 0, 500 and 1000?m, respectively) providing n-dodecane as sole carbon source. Pressures equal to 5 and 10?MPa significantly lowered growth yields of both strains. However, in strain KS_293 grown at 10?MPa CO2 production per cell was not affected, cell integrity was preserved and PO43- uptake increased. Analysis of its transcriptome revealed that 95% of its genes were downregulated. Increased transcription involved protein synthesis, energy generation and respiration pathways. Interplay between these factors may play a key role in shaping the structure of microbial communities developed after oil spills at low depth and limit their bioremediation potential

It’s All About the Punch(line): The Crossing of Masculinity’s Border as Portrayed in Todd Phillips’ Joker

Catcalls, rapists, dick jokes, and risky business are only a handful of symptoms of the current worldwide viral epidemic dubbed “toxic masculinity.” Focusing on toxic masculinity in Todd Phillips’s film, Joker, this essay recounts the toxic behaviors associated with America’s hegemonic masculine system and addresses how party clown and failed comic Arthur Fleck’s journey across masculinity’s border—and transformation into the famous villain, Joker— glorifies the adoption of these toxic traits.  Phillips’s film is an unhealthy influence on young, nontraditionally masculine males. Fleck’s character arc teaches them that using violence, sexually asserting oneself, and withholding emotions all come with serious social benefits and lack any consequences. Phillips claims through Joker that the oppressed unmasculine man can overcome his social hardships by simply replacing his weak, effeminate personality traits (such as crying openly, solving conflicts without physicality, and sexual passivity) with mainstream toxic behaviors. This personality change is necessary to cross the border into mainstream masculinity and elevated social states, according to Phillips’s character study. Phillips’s catch-all solution is a claim I contradict with evidence of the failing health of young men in real-world America, concluding with a plea for the creation of safe spaces for healthy male identity exploration

Sleeping beaus: How toxic masculinity is poisoning America's men

Catcalls, rapists, dick jokes, and risky business are only a handful of symptoms of the current worldwide viral epidemic dubbed “toxic masculinity.” Focusing on hegemonic masculinity’s proposed birthplace, America, this project recounts the hierarchical masculine system’s development and the culmination of its most harmful performative behaviors and widespread dogmas into what we now call “toxic masculinity.” What follows is an exposé of the societal perpetuators which groom young boys throughout their lifetime, and an evaluation of toxic masculinity’s irreparable mental and physical damages. The project’s research portion concludes by addressing the small steps taken thus far to promote healthy masculinity; it proposes further necessary changes on both the individual and societal planes, and presents the ideal alternative to toxic masculinity—mindful masculinity. The project then transitions to a creative retelling of Stephen and Owen Kings’ novel, Sleeping Beauties, wherein the world’s women contract a sleeping sickness and struggle to rebuild society in an alternate realm void of any men, who are left in chaos on Earth’s surface. The included rewrite, Sleeping Beaus, tells the struggle of the world’s men, who, after falling asleep, fail to rebuild civilization until they shed toxic masculinity’s vices.Honors CollegeThesis (B.?

The Effects of Cultural Competence and Racial Identity Development on the Working Alliance in African-American and Caucasian Counseling Dyads: A Preliminary Analysis

Multicultural considerations in behavioral healthcare rightfully remain a point of interest for practitioners, administrators and educators alike. Attention to culturally sensitive practice as a core competency for mental health practitioners has become rooted in academic curriculum and clinical trainings (Bussema & Nemec, 2006; Schottler et al., 2004). Despite this increased awareness of culturally competent practice, the results of these efforts are unclear as minority utilization of behavioral healthcare services continues to decline (Flaskerud, 2007). Racial biases and prejudice are still apparent in administrative and institutional settings that aspire to integrate cultural competencies into their organizations (Sue & Sue, 2007). Literature investigating the translation of training to practice is minimal and inconclusive (Flaskerud, 2007). This study examined how a Caucasian practitioner\u27s degree of cultural competence related to the formation of the therapeutic alliance as well as how each individual\u27s respective stage of racial identity development influenced their relationship. Results observed a significant correlation between a clinician\u27s degree of cultural competence and strength of the therapeutic alliance. Small sample size and lack of differentiation among key variables did not allow for several hypotheses to be tested, however, an exploratory analysis found the subscales of the Working Alliance Inventory (WAI) to be highly predictive of one another between two administrations. A strong negative correlation was observed between the Skills and Awareness subscales of the Multicultural Counseling Inventory (MCI). Outcomes from this investigation were promising and provide future direction for further research in this area

The Development Of Loop-based Cinematic Techniques In Twentieth Century Motion Pictures And Their Application In Early Digital C

For centuries, repetition in one form or another has been seen as a significant element in the artistic palette. In numerous formats of expression, duplication and looping became a significant tool utilized by artisans in a multitude of creative formats. Yet within the realm of film, the Griffith and Eisenstein models of cinematic editing techniques (as the most popular-- and near-monolithic--narrative aesthetic criteria) effectively disregarded most other approaches, including looping. Despite the evidence for the consistent use of repetition and looping in multiple ways throughout the course of cinematic history, some theorists and practitioners maintain that the influx of the technique within digital cinema in recent years represents a sudden breakthrough, one that has arrived simply because technology has currently advanced to a point where their utilization within digital formats now makes sense both technologically and aesthetically. This situation points to a cyclical problem. Students of film and video frequently are not taught aesthetical or editorial options other than standard industry procedures. Those who are interested in varying techniques are therefore put in the position of having to learn alternative practices on their own. When they do look beyond visual norms to try applying different approaches in their projects, they risk going against the views of their instructors who are only interested in implementations of the standard methods which have been in the forefront for so long. Yet the loop s importance and prevalence as a digital language tool will only likely grow with the evolution of digital cinema. With this is mind, the dissertation addresses the following questions: To what extent can various forms of repetitive visuals be found throughout film history, and are not simply technical manifestations that have merely emerged within digital cinema? How might current educational practices in the realm of film and video work to inform students of techniques outside of the common narrative means? Finally, what other sources or strategies might be available to enlighten students and practitioners exploring both the history surrounding--and possible applications of--techniques based upon early cinema practices such as the loop