Detergent and sanitizer stresses decrease the thermal resistance of Enterobacter sakazakii in infant milk formula

Infant milk formula has been identified as a potential source of Enterobacter sakazakii. This bacterium can cause a severe form of neonatal meningitis and necrotizing entercolitis. This study determined the effect of acid, alkaline, chlorine and ethanol stresses on the thermal inactivation of E. sakazakii in infant milk formula. Stressed cells were mixed with reconstituted powdered infant milk formula (PIMF) at temperatures between 52 and 58°C for various time periods or mixed with PFMF prior to reconstitution with water at temperatures between 50 and 100°C. The D- and z-values of the cells were determined using linear regression analysis. Detergent and sanitizer stresses decreased the thermal resistance of E. sakazakii in powdered and reconstituted infant milk formula. The values for Z)- acid, alkaline, chlorine and ethanol stressed E. sakazakii at 52-58°C were 14.57-0.54, 12.07-0.37, 10.08-0.40 and 11.61-0.50 min, respectively. The values of alkaline, chlorine and ethanol stressed cells were significantly lower than those of unstressed cells. Only the z-value (4.4°C) of ethanol stressed E. sakazakii was significantly different than that of unstressed cells (4.12°C). Reconstitution at 60°C did not significantly reduce the number of pre-stressed E. sakazakii cells compared with unstressed control cells, whereas significant decreases were obtained at 70°C. Using water at 70°C during the preparation of reconstituted PIMF before feeding infants, may be a suitable and applicable means of reducing the risk of E. sakazakii in the formula. The results of this study may be of use to regulatory agencies, infant milk producers and infant caregivers to design heating processes to eliminate E. sakazakii that may be present in infant milk formula

COPING EXPERIENCES OF LOW-INCOME INDIVIDUALS WITH A HISTORY OF OPIOID USE IN SANTA CRUZ COUNTY: A QUALITATIVE STUDY

The opioid epidemic has increased exponentially in severity across the United States in the last decade. This research project was conducted to understand the needs of a vulnerable population (opioid users) at the local level. The research sought to answer the following question: How do low-income individuals in Santa Cruz County cope with opioid use? The purpose is to identify the most common coping strategies used by this population, so that social workers and others in helping professions in Santa Cruz County will have a fuller picture of what this vulnerable demographic is facing. The data for this research was collected via 13 anonymous interviews. Data was analyzed via thematic analysis, which produced the following themes: coping strategies, negative effects of opioid use, experiences of services used, and gaps in services. Implications from this research for social work practice include revealing a lack of affordable addiction services, a lack of clarity in services available, and a need for advocacy and local political action to secure funding and program expansion in Santa Cruz County

Paraphrasing away properties with pluriverse counterfactuals

In this paper, I argue that for the purposes of ordinary reasoning, sentences about properties of concrete objects can be replaced with sentences concerning how things in our universe would be related to inscriptions were there a pluriverse. Speaking loosely, pluriverses are composites of universes that collectively realize every way a universe could possibly be. As such, pluriverses exhaust all possible meanings that inscriptions could take. Moreover, because universes necessarily do not influence one another, our universe would not be any different intrinsically if there were a pluriverse. These two facts enable anti-realists about abstract objects to replace, e.g. talk of anatomical features with talk of the inscriptions concerning anatomical structure that would exist were there a pluriverse. The availability of such replacements enables anti-realists to carry out essential ordinary reasoning without referring to properties, thereby making room for a consistent anti-realist worldview. The inscriptions of the would-be pluriverse are so numerous and varied that sentences about them can play the roles in ordinary reasoning served by simple sentences about properties of concrete objects

Effect of desiccation, starvation, heat, and cold stresses on the thermal resistance of Enterobacter sakazakii in rehydrated infant milk formula

Enterobacter sakazakii has been implicated in outbreaks of meningitis, septicemia, and necrotizing enterocolitis in immunocompromised and premature neonates. In this study, the effect of desiccation stress, starvation stress, heat shock and cold shock on thermal inactivation of E. sakazakii in rehydrated infant milk formula was evaluated. Stressed cells were mixed with rehydrated infant milk formula at 52, 54, 56, and 58°C for various time periods. The D- and z-values were determined by using linear regression analysis. Z)-values for unstressed E. sakazakii at 52, 54, 56 and 58°C were 15.33, 4.53, 2.00 and 0.53 min, respectively. Desiccation and heat stress, but not starvation or cold stress, caused significant reduction in Z)-values. For example, D52 was 15.33 min for unstressed cells compared with 8.72 and 7.36 after desiccation and heat stress. Z-values of 53 desiccated, starved, heat shocked and cold shocked E. sakazakii were not significantly different from unstressed cells (4.22°C). The results of this study may be of use to regulatory agencies, infant milk producers and infant caregivers to design heating processes to eliminate E. sakazakii that may be present in infant milk formula

Survival and growth of Cronobacter species (Enterobacter) sakazakii in wheat-based infant follow on formulas

Aim: To determine the survival and growth characteristics of Cronobacter species (Enterobacter sakazakii) in infant wheat-based formulas reconstituted with water, milk, grape juice or apple juice during storage. Methods and Results: Infant wheat-based formulas were reconstituted with water, UHT milk, pasteurized grape or apple juices. The reconstituted formulas were inoculated with C. sakazakii and C. muytjensii and stored at 4, 25 or 37°C for up to 24h. At 25 and 37°C, Cronobacter grew more (>5 logio) in formulas reconstituted with water or milk than those prepared with grape or apple juices (ca. 2-3 logio). The organism persisted, but did not grow in any formulas stored at 4°C. Formulas reconstituted with water and milk decreased from pH 6.0 to 4.8-5.0 after 24h, whereas the pH of the formulas reconstituted with fruit juices remained at their initial pH values, ca. pH 4.8-5.0. Conclusion: C sakazakii and C muytjensii can grow in reconstituted wheat-based formulas. If not immediately consumed, these formulas should be stored at refrigeration temperatures to reduce the risk of infant infection. Significance and Impact of the Study: The results of this study will be of use to regulatory agencies and infant formula producers to recommend storage conditions that reduce the growth of Cronobacter in infant wheat-based formulas

Sequential Ovulation, Fertility of Polyestrus, and Induced Ovulation in American Black Bears (Ursus americanus)

Improving our understanding of the reproductive physiology of bears is critical for effective conservation and management of both captive and wild bears. Increasing our knowledge of bear reproductive physiology is of ever increasing importance due to the fact six of eight species are either threatened or endangered on a global scale, and all 8 species are threatened with extinction in at least some of their range. Bears evolved several unique reproductive physiological adaptations, including multiple paternity and delayed implantation, but other more subtle adaptations may exist as well. This thesis studied, during three mating seasons, a semi-free ranging population of the non-threatened American black bear (Ursus americanus) to better understand the subtle intricacies of the reproductive physiology in bears. This study examined equal estrus fertility and sequential ovulation. Sequential ovulation is defined as ovulations occurring during each estrus, which are temporally sequential. Equal estrus fertility is defined as equal fertility of each estrus of a polyestrous female regardless of current pregnancy status. Ovaries were examined to determine if sequential ovulation occurred in each estrus of polyestrous females. During the mating season, females were anesthetized and their ovaries were observed to document ovulatory events, which allowed accurate pairing of an ovulation with a specific estrus. The presence of both a corpus luteum (CL) and corpus hemorrhagicum (CH) in the same female as well as a recent and well developed CL in 2 of 4 polyestrous females confirms temporally distinct ovulatory events (sequential ovulation) in this study population. Breeding behavior of females was extensively observed and recorded during the breeding seasons to determine if each estrus was fertile regardless of conception status. All mating behavior was recorded until females were anesthetized for examination and embryo extraction. Matching conception to a specific estrus was achieved using paternity testing and examining embryo development. Paternity results of 9 embryos from 6 polyestrous females showed 4 embryos were conceived during the first estrus while 5 were conceived during the second estrus, clearly indicating equal estrus fertility regardless of current conception status. These results strongly indicate the potential of superfetation in the American black bear and provide insight into the complex behavioral and physiological breeding mechanisms of bears. Captive breeding programs may eventually be able to breed females with different males during each estrus to potentially increase the chances of multiple paternity. Induced ovulation has been widely assumed in bears, yet little conclusive evidence exists. The third chapter of this thesis reexamines this question by looking at both hormonal data of isolated females during the mating season and anatomical data of ovulatory events from both successfully bred and unsuccessfully bred females. The estrogen profiles showed clear indications ovulation did occur in the nonmated and isolated females. Ovulatory events also occurred in unsuccessfully mated females, which also had a higher average number of ovulatory events compared to successfully bred females. Although preliminary, the combination of these data challenge the assumption that bears are induced ovulators. Further research is needed to resolve this matter conclusively

Reassessing the Explanatory Indispensability Argument: A Bayesian Defence of Nominalism

Advocates of the explanatory indispensability argument for platonism say two things. First, we should believe in the parts of our best scientific theories that are explanatory. Second, mathematical objects play an explanatory role within those theories. I give a two-part response. I start by using a Bayesian framework to argue that the standards many have proposed must be met to show that mathematical objects are dispensable are too demanding. In particular, nominalistic theories may be more probable than platonistic ones even if they are extremely complicated by comparison. This is true even if there are genuine cases of mathematical explanation in science. The point made here is a matter of principle, holding regardless of how one assesses nominalistic theories already on offer. I then examine my recent nominalization of second-order impure set theory in light of the correct, laxer standards. I make a tentative case that my nominalistic theory meets those standards, which would undermine the explanatory indispensability argument. While this case is provisional, I aim to bring attention to my nominalization and others in light of the revised standards for demonstrating dispensability

Applied Mathematics without Numbers

In this paper, I develop a "safety result" for applied mathematics. I show that whenever a theory in natural science entails some non-mathematical conclusion via an application of mathematics, there is a counterpart theory that carries no commitment to mathematical objects, entails the same conclusion, and the claims of which are true if the claims of the original theory are "correct": roughly, true given the assumption that mathematical objects exist. The framework used for proving the safety result has some advantages over existing nominalistic accounts of applied mathematics. It also provides a nominalistic account of pure mathematics

A Lewisian Argument Against Platonism, or Why Theses About Abstract Objects Are Unintelligible

In this paper, I argue that all expressions for abstract objects are meaningless. My argument closely follows David Lewis’ argument against the intelligibility of certain theories of possible worlds, but modifies it in order to yield a general conclusion about language pertaining to abstract objects. If my Lewisian argument is sound, not only can we not know that abstract objects exist, we cannot even refer to or think about them. However, while the Lewisian argument strongly motivates nominalism, it also undermines certain nominalist theories