538 research outputs found
Microcystin Accumulation in Fish Muscle Tissue: Exploring the Safety of Fish Consumption in Several Michigan Water Bodies
A variety of anthropogenic factors, including global climate change and eutrophication, are causing increases in cyanobacterial abundance. Increased prevalence of cyanobacteria can be detrimental, as some genera of cyanobacteria have the ability to produce toxic secondary metabolites known as cyanotoxins. The cyanotoxin microcystin- a hepatotoxin, is the most ubiquitous and toxic cyanotoxin in freshwater ecosystems, and has been quantified in a number of aquatic organisms. Microcystin was quantified in 8 fish species from St. Mary’s River in June, Saginaw Bay in September, and from Stony Creek Lake in October in 2014 by the Michigan Department of Environmental Quality and the Michigan Department of Natural Resources and findings were compared to current microcystin consumption advisories in order to determine what quantities of fish could be safely consumed. Total microcystin was determined in each sample with enzyme linked immuno sorbent assays and the total quantity of the microcystin variant microcystin-LR (the most toxic variant of microcystin) was determined with Liquid Chromatography coupled with tandem Mass Spectrometry. Results indicated that fish from these water bodies were well within established consumption limits. However, although results indicate that consumption need not be limited, findings from the present study should not be extrapolated beyond the specific time frames and locations studied, due to variability in environmental microcystin concentrations. Therefore, further research spanning long time frames and locations needs to be done in order to confidently determine safe fish consumption limits in regards to microcystin
Determination of transfer of methicillin-resistant Stapylococcus aureus from retail pork products onto food contact surfaces and the potential for consumer exposure
Methicillin-resistant Staphylococcus aureus, commonly referred to as MRSA, first emerged from Staphylococcus aureus in the 1960\u27s as an organism that was resistant to beta-lactam antibiotics such as penicillin. MRSA is able to colonize the skin, mouth and nares of both humans and animals without causing disease. However, if the bacteria gains entry via a cut or other skin abrasion, it can lead to more serious infections such as pneumonia, meningitis and septicemia. The three main types of MRSA infections currently recognized are hospital associated (HA), community associated (CA) and livestock associated (LA).
Recently, MRSA has also been discovered in retail meat products in the United States and other countries throughout the world. This discovery has raised concerns about the possibility of food being a vehicle for MRSA transmission and infection. It has been reported that MRSA can be found in meat processing facilities at any stage of production. Many studies have determined that pork and swine production are the major MRSA reservoirs. The current understanding of how MRSA may be transmitted in the food chain is limited thus preventing proper risk assessment to identify potential hazards to food handlers as well as to consumers.
The purpose of this research is to estimate the percent transfer of MRSA from retail pork products to food contact surfaces (cutting board or knife) and to estimate the risk of consumer exposure to
MRSA via contact with contaminated products and contaminated food contact surfaces. In order to simulate how these events may occur; pork products were obtained from a local supplier and inoculated with a 4 strain MRSA mixed culture at levels of 10, 100, 1,000, 10,000 and 100,000 CFU/ ml. Products were then analyzed to obtain initial bacterial populations. All products were vacuum- packaged and stored at 5°C for 2 weeks to simulate normal packaging and distribution. After 2 weeks, products were aseptically removed from the vacuum package and exposed to the transfer surfaces via 2 methods: light exposure to assess the percent transfer of MRSA from product to surface and heavy exposure to assess human exposure from contaminated products and surfaces. In light exposure, samples were laid on the transfer surfaces at room temperature for 5 minutes without any additional weight on the product and allowed to sit at room temperature before analysis. In heavy exposure, samples were laid on the transfer surface and a 500g lead donut was placed on top of the product as it was moved across a defined area of the transfer surface. The transfer surfaces then sat for 5 minutes at room temperature before being analyzed.
2
It was found that MRSA not only survived on the pork products during 2 weeks of cold storage but was able to transfer to food contact surfaces. This was true for all products tested across all 5 cell concentrations. These results suggest that even when cell concentration is low (≤ 10 CFU/cm2) human exposure is possible. Even though MRSA may only be present in very small quantities, more research is needed to determine the infectious dose of MRSA that may be in meat products in order to establish a risk assessment. Public education on safe raw meat handling and cooking practices should be continued as well as education of food handlers until there is a better understanding of the infectious dose of MRSA in raw meat products
The Puzzle of Humility and Disparity
Suppose that you are engaging with someone who is your oppressor, or someone who espouses a heinous view like Nazism or a ridiculous view like flat-earthism. In contexts like these, there is a disparity between you and your interlocutor, a dramatic normative difference across which you are in the right and they are in the wrong. As theorists of humility, we find these contexts puzzling. Humility seems like the *last* thing oppressed people need and the *last* thing we need in dealing with those whose views are heinous or ridiculous. Responding to such people via humility seems uncalled for, even inappropriate. But how could this be, given that humility is a *virtue*? The purpose of the paper is to explore this puzzle. We explain what the puzzle is and then attempt to draw some lessons from it: first, the lesson that the importance of humility is limited in several ways, and second, the lesson that humility nonetheless has several important roles to play, even for people who are in the right in contexts of disparity
Single Source of Error State Space Approach to the Beveridge Nelson Decomposition
A well known property of the Beveridge Nelson decomposition is that the innovations in the permanent and transitory components are perfectly correlated. We use a single source of error state space model to exploit this property and perform a Beveridge Nelson decomposition. The single source of error state space approach to the decomposition is computationally simple, and in contrast to other methods of performing the Beveridge-Nelson decomposition, it incorporates the direct estimation of the long-run multiplier.Beveridge Nelson decomposition; Long-run multiplier; Single source of error; State-space models.
Beveridge-Nelson Decomposition with Markov Switching
This paper considers Beveridge-Nelson decomposition in a context where the permanent and transitory components both follow a Markov switching process. Our approach incorporates Markov switching into a single source of error state-space framework, allowing business cycle asymmetries and regime switches in the long run multiplier.Beveridge-Nelson decomposition, Markov switching, Single source of error state space models
Combining insulins for optimal blood glucose control in type 1 and 2 diabetes: Focus on insulin glulisine
Normalization of blood glucose is essential for the prevention of diabetes mellitus (DM)-related microvascular and macrovascular complications. Despite substantial literature to support the benefits of glucose lowering and clear treatment targets, glycemic control remains suboptimal for most people with DM in the United States. Pharmacokinetic limitations of conventional insulins have been a barrier to achieving treatment targets secondary to adverse effects such as hypoglycemia and weight gain. Recombinant DNA technology has allowed modification of the insulin molecule to produce insulin analogues that overcome these pharmacokinetic limitations. With time action profiles that more closely mimic physiologic insulin secretion, rapid acting insulin analogues (RAAs) reduce post-prandial glucose excursions and hypoglycemia when compared to regular human insulin (RHI). Insulin glulisine (Apidra®) is a rapid-acting insulin analogue created by substituting lysine for asparagine at position B3 and glutamic acid for lysine at position B29 on the B chain of human insulin. The quick absorption of insulin glulisine more closely reproduces physiologic first-phase insulin secretion and its rapid acting profile is maintained across patient subtypes. Clinical trials have demonstrated comparable or greater efficacy of insulin glulisine versus insulin lispro or RHI, respectively. Efficacy is maintained even when insulin glulisine is administered post-meal. In addition, glulisine appears to have a more rapid time action profile compared with insulin lispro across various body mass indexes (BMIs). The safety and tolerability profile of insulin glulisine is also comparable to that of insulin lispro or RHI in type 1 or 2 DM and it has been shown to be as safe and effective when used in a continuous subcutaneous insulin infusion (CSII). In summary, insulin glulisine is a safe, effective, and well tolerated rapid-acting insulin analogue across all BMIs and a worthy option for prandial glucose control in type 1 or 2 DM
The creative self: Do people distinguish creative self-perceptions, efficacy, and personal identity?
Intellectual Humility: Owning Our Limitations
What is intellectual humility? In this essay, we aim to answer this question by assessing several contemporary accounts of intellectual humility, developing our own account, offering two reasons for our account, and meeting two objections and solving one puzzl
Finding middle ground between intellectual arrogance and intellectual servility: Development and assessment of the limitations-owning intellectual humility scale
Recent scholarship in intellectual humility (IH) has attempted to provide deeper understanding of the virtue as personality trait and its impact on an individual's thoughts, beliefs, and actions. A limitations-owning perspective of IH focuses on a proper recognition of the impact of intellectual limitations and a motivation to overcome them, placing it as the mean between intellectual arrogance and intellectual servility. We developed the Limitations-Owning Intellectual Humility Scale to assess this conception of IH with related personality constructs. In Studies 1 (n= 386) and 2 (n = 296), principal factor and confirmatory factor analyses revealed a three-factor model – owning one's intellectual limitations, appropriate discomfort with intellectual limitations, and love of learning. Study 3 (n = 322) demonstrated strong test-retest reliability of the measure over 5 months, while Study 4 (n = 612) revealed limitations-owning IH correlated negatively with dogmatism, closed-mindedness, and hubristic pride and positively with openness, assertiveness, authentic pride. It also predicted openness and closed-mindedness over and above education, social desirability, and other measures of IH. The limitations-owning understanding of IH and scale allow for a more nuanced, spectrum interpretation and measurement of the virtue, which directs future study inside and outside of psychology
Accessing 3D Data
The issue of access and discoverability is not simply a matter of permissions and availability. To identify, locate, retrieve, and reuse 3D materials requires consideration of a multiplicity of content types, as well as community and financial investment to resolve challenges related to usability, interoperability, sustainability, and equity. This chapter will cover modes, audiences, assets and decision points, technology requirements, and limitations impacting access, as well as providing recommendations for next steps
- …