Matching Items (184)
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Description

The production, characterization, and antioxidant capacity of the carotenoid fucoxanthin from the marine diatom Odontella aurita were investigated. The results showed that low light and nitrogen-replete culture medium enhanced the biosynthesis of fucoxanthin. The maximum biomass concentration of 6.36 g L-1 and maximum fucoxanthin concentration of 18.47 mg g-1 were

The production, characterization, and antioxidant capacity of the carotenoid fucoxanthin from the marine diatom Odontella aurita were investigated. The results showed that low light and nitrogen-replete culture medium enhanced the biosynthesis of fucoxanthin. The maximum biomass concentration of 6.36 g L-1 and maximum fucoxanthin concentration of 18.47 mg g-1 were obtained in cultures grown in a bubble column photobioreactor (Ø 3.0 cm inner diameter), resulting in a fucoxanthin volumetric productivity of 7.96 mg L-1 day-1. A slight reduction in biomass production was observed in the scaling up of O. aurita culture in a flat plate photobioreactor, yet yielded a comparable fucoxanthin volumetric productivity. A rapid method was developed for extraction and purification of fucoxanthin. The purified fucoxanthin was identified as all-trans-fucoxanthin, which exhibited strong antioxidant properties, with the effective concentration for 50% scavenging (EC50) of 1,1-dihpenyl-2-picrylhydrazyl (DPPH) radical and 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical being 0.14 and 0.03 mg mL-1, respectively. Our results suggested that O. aurita can be a natural source of fucoxanthin for human health and nutrition.

ContributorsXia, Song (Author) / Wang, Ke (Author) / Wan, Linglin (Author) / Li, Aifen (Author) / Hu, Qiang (Author) / Zhang, Chengwu (Author) / Julie Ann Wrigley Global Institute of Sustainability (Contributor)
Created2013-07-23
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Description

Human vulnerability to heat varies at a range of spatial scales, especially within cities where there can be noticeable intra-urban differences in heat risk factors. Mapping and visualizing intra-urban heat vulnerability offers opportunities for presenting information to support decision-making. For example the visualization of the spatial variation of heat vulnerability

Human vulnerability to heat varies at a range of spatial scales, especially within cities where there can be noticeable intra-urban differences in heat risk factors. Mapping and visualizing intra-urban heat vulnerability offers opportunities for presenting information to support decision-making. For example the visualization of the spatial variation of heat vulnerability has the potential to enable local governments to identify hot spots of vulnerability and allocate resources and increase assistance to people in areas of greatest need. Recently there has been a proliferation of heat vulnerability mapping studies, all of which, to varying degrees, justify the process of vulnerability mapping in a policy context. However, to date, there has not been a systematic review of the extent to which the results of vulnerability mapping studies have been applied in decision-making. Accordingly we undertook a comprehensive review of 37 recently published papers that use geospatial techniques for assessing human vulnerability to heat. In addition, we conducted an anonymous survey of the lead authors of the 37 papers in order to establish the level of interaction between the researchers as science information producers and local authorities as information users. Both paper review and author survey results show that heat vulnerability mapping has been used in an attempt to communicate policy recommendations, raise awareness and induce institutional networking and learning, but has not as yet had a substantive influence on policymaking or preventive action.

Created2015-10-23
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Description

Myxoma virus (MYXV) is Leporipoxvirus that possesses a specific rabbit‐restricted host tropism but exhibits a much broader cellular host range in cultured cells. MYXV is able to efficiently block all aspects of the type I interferon (IFN)‐induced antiviral state in rabbit cells, partially in human cells and very poorly in

Myxoma virus (MYXV) is Leporipoxvirus that possesses a specific rabbit‐restricted host tropism but exhibits a much broader cellular host range in cultured cells. MYXV is able to efficiently block all aspects of the type I interferon (IFN)‐induced antiviral state in rabbit cells, partially in human cells and very poorly in mouse cells. The mechanism(s) of this species‐specific inhibition of type I IFN‐induced antiviral state is not well understood. Here we demonstrate that MYXV encoded protein M029, a truncated relative of the vaccinia virus (VACV) E3 double‐stranded RNA (dsRNA) binding protein that inhibits protein kinase R (PKR), can also antagonize the type I IFN‐induced antiviral state in a highly species‐specific manner. In cells pre‐treated with type I IFN prior to infection, MYXV exploits M029 to overcome the induced antiviral state completely in rabbit cells, partially in human cells, but not at all in mouse cells. However, in cells pre‐infected with MYXV, IFN‐induced signaling is fully inhibited even in the absence of M029 in cells from all three species, suggesting that other MYXV protein(s) apart from M029 block IFN signaling in a speciesindependent manner. We also show that the antiviral state induced in rabbit, human or mouse cells by type I IFN can inhibit M029‐knockout MYXV even when PKR is genetically knocked‐out, suggesting that M029 targets other host proteins for this antiviral state inhibition. Thus, the MYXV dsRNA binding protein M029 not only antagonizes PKR from multiple species but also blocks the type I IFN antiviral state independently of PKR in a highly species‐specific fashion.

Created2017-02-02
Description
Major Depressive Disorder (MDD) is a common mental disorder that can affect individuals at nearly every stage of life. Women are especially vulnerable to MDD in part, from ovarian hormone level fluctuations. In this thesis, I focused on MDD using a rat model in middle-age to explore potential sex differences

Major Depressive Disorder (MDD) is a common mental disorder that can affect individuals at nearly every stage of life. Women are especially vulnerable to MDD in part, from ovarian hormone level fluctuations. In this thesis, I focused on MDD using a rat model in middle-age to explore potential sex differences in response to a corticosterone (CORT) – induced depressive-like state. Estradiol (E2), a naturally occurring steroid sex hormone in humans and rats, is implicated in mood changes, which is especially prominent during the menopause transition. CORT, a stress hormone, was used to create a depressive-like state in middle-aged female (F) and male (M) rats with their gonads surgically removed. This produced the following independent treatment groups: Sex (F, M), CORT (vehicle = V ml/kg, C 40mg/kg), E2 (V 0.1 ml, E 0.3µg/0.1ml). CORT and E2 injections were injected daily, s.c) for 7 days before behavioral testing began and continued throughout the study when behavior was assessed. For my honor’s thesis, I focused on the social interaction test and elevated plus maze to investigate whether CORT enhanced social avoidance and anxiety, and whether E2 mitigated the CORT effects. In the social interaction test, three new behaviors were assessed (interacting, grooming, and immobility) to better understand exploratory and anxiety profiles of the rats, and these behaviors were quantified over two 5-minute periods in the 10-minute trial. These new quantifications showed that for the female rats, C+E and V+V enhanced the interaction with the novel rat significantly more than an inanimate object, which was not observed in the females given CORT only or E2 only. The males in all conditions showed a significant preference for side with the novel rat compared to the object, however no treatment differences were observed. In both sexes, the overall time spent interacting decreased in the second five minutes of quantification compared to the first five minutes. No effects were observed with grooming or immobility, in part from the high variability across rats. For EPM, female rats treated with CORT and E2 exhibited a lower anxiety index than compared to female rats given CORT only, indicating that E2 mitigated the depressive-like effects of CORT. Males showed no CORT or E2 effects. The result in part supported my hypothesis, as the CORT-treated females exhibited reduced socialization and E2 improved socialization in CORT-treated females, as this was seen in the F-C-E group. Interestingly, CORT failed to produce a depressive-like effect in males in both behavioral tests, which was an unexpected outcome. These results suggest that administration of E2 with CORT mitigated the depressive-like state created by CORT in female rats, however failed to produce these outcomes in males. The outcome of this work will give us insight into the potential mechanisms that may contribute to sex differences with MDD.
ContributorsSladkova, Sara (Author) / Conrad, Cheryl (Thesis director) / Amdam, Gro (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor)
Created2024-05