Functional consequences of animal community changes in managed grasslands: An application of the CAFE approach.

In the midst of an ongoing biodiversity crisis, much research has focused on species losses and their impacts on ecosystem functioning. The functional consequences (ecosystem response) of shifts in communities are shaped not only by changes in species richness, but also by compositional shifts that result from species losses and gains. Species differ in their contribution to ecosystem functioning, so species identity underlies the consequences of species losses and gains on ecosystem functions. Such research is critical to better predict the impact of disturbances on communities and ecosystems. We used the "Community Assembly and the Functioning of Ecosystems" (CAFE) approach, a modification of the Price equation to understand the functional consequences and relative effects of richness and composition changes in small nonvolant mammal and dung beetle communities as a result of two common disturbances in North American prairie restorations, prescribed fire and the reintroduction of large grazing mammals. Previous research in this system has shown dung beetles are critically important decomposers, while small mammals modulate much energy in prairie food webs. We found that dung beetle communities were more responsive to bison reintroduction and prescribed fires than small nonvolant mammals. Dung beetle richness increased after bison reintroduction, with higher dung beetle community biomass resulting from changes in remaining species (context-dependent component) rather than species turnover (richness components); prescribed fire caused a minor increase in dung beetle biomass for the same reason. For small mammals, bison reintroduction reduced energy transfer through the loss of species, while prescribed fire had little impact on either small mammal richness or energy transfer. The CAFE approach demonstrates how bison reintroduction controls small nonvolant mammal communities by increasing prairie food web complexity, and increases dung beetle populations with possible benefits for soil health through dung mineralization and soil bioturbation. Prescribed fires, however, have little effect on small mammals and dung beetles, suggesting a resilience to fire. These findings illustrate the key role of re-establishing historical disturbance regimes when restoring endangered prairie ecosystems and their ecological function.

Reintroduced megaherbivores indirectly shape small-mammal responses to moonlight.

Moonlight structures activity patterns of many nocturnal species. Bright moonlight often limits the activity of nocturnal prey, but dense vegetation weakens this effect. Using 8 years of live-trapping data, we asked whether reintroduced megaherbivores (Bison bison) indirectly altered moonlight avoidance by small mammals in tallgrass prairies. In plots with bison, plants intercepted 20% less light, allowing more moonlight to reach ground level. During nights with no moonlight, Peromyscus maniculatus activity was similar in plots with and without bison. During nights with peak moonlight, P. maniculatus activity was four times greater in plots without bison compared to plots with bison. Conversely, Microtus ochrogaster activity was twice as great during full moons compared to new moons, but only in plots with bison. We also equipped a subset of traps with temperature sensors to estimate trap-entry time. Although M. ochrogaster was more active on bright nights, most activity occurred before moonrise or after moonset, avoiding periods of bright moonlight. We conclude that megaherbivores play an unappreciated but important indirect role in tallgrass prairies by inducing behavioral shifts in other animal species. Because overlap in activity patterns can predict the likelihood of predator-prey encounters, such activity shifts have important implications for trophic interactions throughout restored prairie food webs. Additional work to understand interspecific and intraspecific variation in response to moonlight may improve efforts to forecast changes in community assembly due to restoration and land-use change.

Reactive nitrogen species in acetaminophen-induced mitochondrial damage and toxicity in mouse hepatocytes.

Acetaminophen (APAP) toxicity in primary mouse hepatocytes occurs in two phases. The initial phase (0-2 h) occurs with metabolism to N-acetyl-p-benzoquinoneimine which depletes glutathione, and covalently binds to proteins, but little toxicity is observed. Subsequent washing of hepatocytes to remove APAP and reincubating in media alone (2-5 h) results in toxicity. We previously reported that the reincubation phase occurs with mitochondrial permeability transition (MPT) and increased oxidative stress (dichlorodihydrofluorescein fluorescence) (DCFH(2)). Since DCFH(2) may be oxidized by multiple oxidative mechanisms, we investigated the role of reactive nitrogen species (RNS) leading to 3-nitrotyrosine in proteins by ELISA and by immunoblots. Incubation of APAP with hepatocytes for 2 h did not result in toxicity or protein nitration; however, washing hepatocytes and reincubating in media alone (2-5 h) resulted in protein nitration which correlated with toxicity. Inclusion of the MPT inhibitor, cyclosporine A, in the reincubation media eliminated toxicity and protein nitration. The general nitric oxide synthase (NOS) inhibitor L-NMMA and the neuronal NOS (NOS1) inhibitor, 7-nitroindazole, added in the reincubation media decreased toxicity and protein nitration; however, neither the inducible NOS (NOS2) inhibitors L-NIL (N6-(1-iminoethyl)-L-lysine) nor SAIT (S-(2-aminoethyl)isothiourea) decreased protein nitration or toxicity. The RNS scavengers, N-acetylcysteine, and high concentrations of APAP, added in the reincubation phase decreased toxicity and protein nitration. 7-Nitroindazole and cyclosporine A inhibited the APAP-induced loss of mitochondrial membrane potential when added in the reincubation phase. The data indicate a role for RNS in APAP induced toxicity.

Evaluation of Chlorine Dioxide Gas against Four Salmonella enterica Serovars Artificially Contaminated on Whole Blueberries.

ABSTRACT: Fresh produce, such as blueberries, continues to be a source of foodborne illness in the United States. Despite new practices and intervention technologies, blueberries and other produce are contaminated with foodborne pathogens, such as Salmonella. The aim of this study was to evaluate the efficacy of chlorine dioxide gas (CDG) against Salmonella enterica serovars Newport, Stanley, Muenchen, and Anatum on artificially contaminated whole fresh blueberries. Blueberries were dip inoculated into a 400-mL bath containing a Salmonella serovar cocktail of either ca. 6 or 9 log CFU/mL. Samples were dried for either 2 or 24 h before treatment with 1.5 or 3 mg of CDG/L of air to a final treatment of 3.55 to 6 ppm/h/g of blueberry. Salmonella cells were recovered by stomaching CDG-treated and nontreated control samples with 0.1% peptone and enumerated on xylose lysine Tergitol 4 agar. CDG treatments achieved up to a 5.63-log CFU/g reduction of the cocktail using 5.5 ppm/h/g, whereas the lowest treatment, 4 ppm/h/g (1.5 mg of CDG/L), was still capable of a 4.45-log CFU/g reduction. Incubation time significantly (P < 0.001) affected CDG efficacy against both inoculation concentrations. Additionally, all serovars responded similarly to CDG treatment when tested individually (P > 0.0691). Finally, the availability of a water reservoir during treatments did not have a significant effect (P = 0.9818) on CDG efficacy in this study. Our results demonstrate that CDG can be an efficacious treatment option for whole blueberry decontamination.

Experimental study on the hemostatic effect of cyanoacrylate intended for catheter securement.

PURPOSE:: The use of cyanoacrylate for intravenous catheter securement is of interest to clinicians and patients, because of the superior adhesive strength and hemostatic effect of cyanoacrylate compared to current securement devices. The purpose of this study is to use novel in vitro and in vivo testing methods to analyze the hemostatic effect of a catheter securement cyanoacrylate (cyanoacrylate). METHODS:: An unprecedented in vitro method was performed to determine the effects of a cyanoacrylate on a customized modified activated clotting time assay and blood flow inhibition assay by exposing blood or plasma to either one or three drops of cyanoacrylate. For the in vivo testing, full-thickness incisions were made on swine, and the bleeding was scored prior to treatment and at 3, 6, 9, and 12 min after treatment. RESULTS:: The cyanoacrylate rapidly achieved hemostasis in the presence of anticoagulated whole blood, platelet-poor plasma, and non-anticoagulated whole blood, in vitro. The cyanoacrylate achieved hemostasis 12-fold faster than thromboplastin in the modified activated clotting time assay. The cyanoacrylate does not alter normal blood clotting, as measured by prothrombin time. In vivo, the bleeding score of cyanoacrylate prior to treatment and at 3, 6, 9, and 12 min after treatment were 2.3 ± 1.0, 0.3 ± 0.5, 0.2 ± 0.5, 0.2 ± 0.4, and 0.2 ± 0.4, respectively. CONCLUSION:: This study indicates that cyanoacrylate demonstrates a potent mechanical hemostatic effect and cyanoacrylate in the presence of anticoagulated whole blood has an activated clotting time that is 12 times quicker than thromboplastin. The cyanoacrylate was found to be significantly equivalent to two known hemostatic agents, in vivo.

Evaluation of Hot Water, Gaseous Chlorine Dioxide, and Chlorine Treatments in Combination with an Edible Coating for Enhancing Safety, Quality, and Shelf Life of Fresh-Cut Cantaloupes.

Fresh-cut cantaloupes have been implicated in numerous foodborne outbreaks of salmonellosis. Commercial aqueous wash treatments are limited in their ability to inactivate Salmonella enterica. Our objective was to evaluate the efficacy of hot water, gaseous chlorine dioxide, and chlorine on enhancing microbial safety and sensory qualities of fresh-cut cantaloupes. Cantaloupes were inoculated with an S. enterica cocktail (serovars Michigan, Mbandaka, and Poona) and treated with chlorine (200 ppm of free chlorine) for 40 min, 5 mg/L gaseous chlorine dioxide for 4.5 h, and hot water (76.1°C) for 3 min. Fresh-cut cantaloupes were prepared from treated whole cantaloupes and divided into two sets; one set of samples was treated with NatureSeal to evaluate its effect on shelf life and sensory quality and the second set (control) was packed without further treatment. Fresh-cut samples were stored at 4°C for up to 21 days. For the sensory quality parameters analyzed (color, water loss, and texture), the samples treated with NatureSeal had significantly better quality ( P < 0.05) than did the control samples. All treatments significantly reduced ( P < 0.05) the pathogen populations on the rind of the whole melons and on the fresh-cut samples prepared from the treated melons. All fresh-cut samples prepared from melons treated with hot water were negative for Salmonella throughout the storage period except for the samples treated with hot water and NatureSeal and evaluated on day 7. The fresh-cut samples prepared from melons treated with chlorine dioxide and chlorine were negative for Salmonella after 21 days of storage. These results provide a framework to producers of fresh-cut cantaloupes for the potential use of hot water as an intervention treatment in combination with NatureSeal for enhancing the microbiological safety and quality of this commodity.

Mechanisms of chloroform-induced hepatotoxicity: oxidative stress and mitochondrial permeability transition in freshly isolated mouse hepatocytes.

The role of mitochondrial permeability transition (MPT) and oxidative stress in chloroform toxicity was determined in freshly isolated female B6C3F1 mouse hepatocytes. Incubation of chloroform (12 mM) with hepatocytes resulted in cell death (alanine aminotransferase release and propidium iodide fluorescence). Chloroform had volatilized from the incubation and glutathione was depleted by 1 h; however, toxicity was not significantly different between control and chloroform-incubated cells. Hepatocytes were washed and reincubated in fresh media at 1 h. Subsequent reincubation of chloroform-treated hepatocytes resulted in significant toxicity at 3-5 h. Inclusion of the MPT inhibitor cyclosporine A or the antioxidant N-acetylcysteine (NAC) in the reincubation media at 1 h prevented toxicity. Confocal microscopy studies with the dye calcein AM indicated MPT that was blocked by cyclosporine A or NAC. Fluorescence microscopy studies utilizing JC-1 indicated loss of mitochondrial membrane potential, which was also blocked by cyclosporine A or NAC. Dichlorofluorescein fluorescence increased during the reincubation phase, indicating increased oxidative stress, and the increase was blocked by cyclosporine A. Since oxidative stress may occur by peroxynitrite, its role in toxicity was examined. Either of the nitric oxide synthase inhibitors N(G)-methyl-L-arginine (L-NMMA) and 7-nitroindazole (7-NI) at 1 h blocked toxicity. Western blot analysis of hepatocytes for 3-nitrotyrosine in proteins, a biomarker of peroxynitrite, indicated one major nitrated protein at 81 kD. Nitration of this protein was inhibited by cyclosporine A, L-NMMA, 7-NI, or NAC. The data indicate that chloroform-induced cell death occurs in two phases: a metabolic phase characterized by glutathione depletion, and an oxidative phase characterized by MPT and protein nitration.

Combination of hot-water surface pasteurization of whole fruit and low-dose gamma irradiation of fresh-cut cantaloupe.

Improvements in methods for disinfecting fresh-cut cantaloupe could reduce spoilage losses and reduce the risk of foodborne illness from human pathogen contamination. The objective of this study was to investigate the feasibility of using hot-water treatment in combination with low-dose irradiation to reduce native microbial populations while maintaining the quality of fresh-cut cantaloupe. Whole cantaloupes were washed in tap water at 20 or 76 degrees C for 3 min. Fresh-cut cantaloupe cubes, prepared from the washed fruit, were then packaged in clamshell containers, and half the samples were exposed to 0.5 kGy of gamma radiation. Native microflora populations and sensory qualities were evaluated during the subsequent 7 days of storage at 4 degrees C. The hot-water surface pasteurization reduced the microflora population by 3.3 log on the surface of whole fruits, resulting in a lower microbial load on the fresh-cut cubes compared with cubes cut from fruit treated with cold water. Irradiation of cubes prepared from untreated fruit to an absorbed dose of 0.5 kGy achieved a low microbial load similar to that of cubes prepared from hot-water-treated fruit. The combination of the two treatments was able to further reduce the microflora population. During storage, the headspace atmosphere of the packages was not significantly influenced by any of the treatments. Color, titratable acidity, pH, ascorbic acid, firmness, and drip loss were not consistently affected by treatment with irradiation, hot water, or the combination of the two. Cubes prepared from hot-water-treated whole fruit had slightly lower soluble solids content. The combination of hot-water pasteurization of whole cantaloupe and low-dose irradiation of packaged fresh-cut melon can reduce the population of native microflora while maintaining the quality of this product.

Development of Combined Dry Heat and Chlorine Dioxide Gas Treatment with Mechanical Mixing for Inactivation of Salmonella enterica Serovar Montevideo on Mung Bean Seeds.

Foodborne outbreaks have been associated with the consumption of fresh sprouted beans. The sprouting conditions of mung bean seeds provide optimal conditions of temperature and relative humidity for any potential pathogenic contaminant on the seeds to grow. The lack of a kill step postsprouting is a major safety concern. Thus, the use of a kill step on the seeds prior to a sprouting step would enhance the safety of fresh sprouts. The objective of this work was to evaluate the effectiveness of the combined thermal and chlorine dioxide gas (3.5 mg/liter of air) treatment with mechanical mixing (tumbling) to eliminate Salmonella on artificially inoculated mung bean seeds. Although no viable Salmonella was recovered from seeds treated in hot water at 60°C for 2 h, these treated seeds failed to germinate. Dry heat treatments (55, 60, or 70°C) for up to 8 h reduced Salmonella populations in excess of 3 log CFU/g. The use of tumbling, while treating the seeds, resulted in up to 1.6 log CFU/g reduction in Salmonella populations compared with no tumbling. Dry heat treatment at 65°C for 18 h with tumbling resulted in a complete inactivation of Salmonella populations on inoculated seeds with low inoculum levels (2.83 log CFU/g) as compared with high inoculum levels (4.75 log CFU/g). The increased reductions in pathogenic populations on the seeds with the use of tumbling could be attributed to increased uniformity of heat transfer and exposure to chlorine dioxide gas. All treated seeds were capable of germinating, as well as the nontreated controls. These results suggest that this combined treatment would be a viable process for enhancing the safety of fresh sprouts.

Surface pasteurization of whole fresh cantaloupes inoculated with Salmonella poona or Escherichia coli.

Numerous outbreaks of salmonellosis by Salmonella Poona have been associated with the consumption of cantaloupe. Commercial washing processes for cantaloupe are limited in their ability to inactivate or remove this human pathogen. Our objective was to develop a commercial-scale surface pasteurization process to enhance the microbiological safety of cantaloupe. Populations of indigenous bacteria recovered from cantaloupes that were surface pasteurized at 96, 86, or 76 degrees C for 2 to 3 min were significantly (P < 0.05) lower than those of the controls. Whole cantaloupes, surface inoculated with Salmonella Poona RM 2350 or Escherichia coli ATCC 25922 to a final cell concentration of ca. 5 log CFU/cm2 were stored at 4 degrees C or room temperature (RT = 19+/-1 degrees C) for up to 72 h before processing. Treatments at 76 degrees C for 2 to 3 min at 24 h postinoculation resulted in a reduction in excess of 5 log CFU/cm2 of Salmonella Poona and E. coli populations. Cantaloupes that were surface pasteurized and stored at 4 degrees C for 21 days retained their firmness qualities and had no visible mold growth compared with the controls, which became soft and moldy. These results indicate that surface pasteurization will enhance the microbiological safety of cantaloupes and will extend the shelf life of this commodity as well. Storage of untreated inoculated cantaloupes at RT for 24 to 72 h postinoculation caused a significant (P < 0.05) increase in Salmonella Poona and E. coli populations compared with storage at 4 degrees C. This indicates that cantaloupes should be refrigerated as soon as possible following harvest to suppress the growth of any possible contaminant on the rind.

Zen shiatsu: a longitudinal case study measuring stress reduction in a child with autism spectrum disorder.

INTRODUCTION: Autism Spectrum Disorder (ASD) is a developmental disability that manifests as impairments in social interaction, communication, and behavior. OBJECTIVE: The objective of this study is to determine if Zen Shiatsu can reduce short- and long-term stress levels in a child with ASD. METHODS: This is a longitudinal case study of a seven-year-old male with a diagnosis of autism who was given 20-min Zen Shiatsu sessions weekly for six consecutive weeks. Using a five-point stress scale designed for children with autism, the client indicated his stress level before and after each session. In addition, the parent was given the PEDS QL 4.0 Young Child Questionnaire to determine the child's HRQoL (Health Related Quality of Life) prior to Zen Shiatsu treatment to establish a baseline. The parent completed the same questionnaire after six weeks of sessions to compare results. RESULTS: Based on the five-point pictorial stress scale, data collected before and after each Zen Shiatsu session indicated a decrease in stress levels after treatment. The PEDS QL 4.0 showed higher HRQoL scores in all domains, indicating that the child's overall quality of life improved within the six weeks of receiving Zen Shiatsu. CONCLUSIONS: Zen Shiatsu, a Japanese modality based on traditional Chinese medicine, provided meaningful and positive benefits for a child with autism. This case study offers preliminary evidence for the possibility of Zen Shiatsu providing a viable complementary therapy for alleviating stress in children with Autism Spectrum Disorder, thereby potentially improving the overall health-related quality of life.

Commercial thermal process for inactivating Salmonella Poona on surfaces of whole fresh cantaloupes.

Outbreaks of salmonellosis by Salmonella Poona and listeriosis by Listeria monocytogenes have been associated with the consumption of cantaloupes. Commercial washing processes for cantaloupes are limited in their ability to inactivate and/or remove this human pathogen. Our objective was to develop a commercial-scale surface pasteurization process for enhancing microbiological safety of cantaloupes. Whole cantaloupes, surface inoculated with Salmonella Poona RM 2350, were stored at 32°C for 24 h prior to processing. Temperature-penetration profiles indicated that the surface temperature of the whole cantaloupe was 26 and 30°C below that of the hot water temperature after 2 min of immersion at 82 and 92°C, respectively. Hot water treatments at 92°C for 60 and 90 s reduced Salmonella Poona populations in excess of 5 log CFU/g of rind. Cantaloupes that were treated and stored at 4°C for 9 days retained their firmness quality and maintained nondetectable levels of Salmonella Poona as compared with the controls. Also, levels of Salmonella Poona on fresh-cut cantaloupe prepared from hot water-treated cantaloupes and stored for 9 days at 4°C were nondetectable as compared with the controls. These results indicate that surface pasteurization at 92°C for 90 s will enhance the microbiological safety of cantaloupes and will extend the shelf life of this commodity as well. The process parameter of 90 s or less falls within the commercial requirements of the whole-cantaloupe processor-packer industry.

Toxicological and toxicokinetic analysis of angiotensin (1-7) in two species.

The objectives of this study were to determine the potential systemic and local toxicity, as well as evaluate the toxicokinetic (TK) profile of angiotensin (1-7) [A(1-7)] when administered daily via subcutaneous injection for 28 days to Sprague-Dawley rats and Beagle dogs. A(1-7) is a member of the renin-angiotensin system and has undergone clinical evaluation for the treatment of chemotherapy-induced myelosuppression. In this present study, A(1-7) was given at 10 mg/(kg day) for 28 days to rats and canines. At day 27, blood was harvested to evaluate the TK parameters. On day 28, systemic toxicology was evaluated. Following A(1-7) administration for 27 days, no plasma A(1-7) accumulation was detected in canines; however, increased A(1-7) plasma concentrations were detected in rats. Despite the accumulation observed in rats, no detectable toxicity was found following A(1-7) administration for 28 days. The TK analysis of A(1-7) revealed a plasma half-life of 20-30 min in both rats and canines. The time to maximum plasma concentration was found to be 15 and 26.25 min in rats and canines, respectively. This study shows that subcutaneous administration of A(1-7) at 10 mg/(kg day) for 28 days did not lead to any detectable toxicities in either rats or canines.

Efficacy of chlorine, acidic electrolyzed water and aqueous chlorine dioxide solutions to decontaminate Escherichia coli O157:H7 from lettuce leaves.

This study compared the efficacy of chlorine (20-200 ppm), acidic electrolyzed water (50 ppm chlorine, pH 2.6), acidified sodium chlorite (20-200 ppm chlorite ion concentration, Sanova), and aqueous chlorine dioxide (20-200 ppm chlorite ion concentration, TriNova) washes in reducing populations of Escherichia coli O157:H7 on artificially inoculated lettuce. Fresh-cut leaves of Romaine or Iceberg lettuce were inoculated by immersion in water containing E. coli O157:H7 (8 log CFU/ml) for 5 min and dried in a salad spinner. Leaves (25 g) were then washed for 2 min, immediately or following 24 h of storage at 4 degrees C. The washing treatments containing chlorite ion concentrations of 100 and 200 ppm were the most effective against E. coli O157:H7 populations on Iceberg lettuce, with log reductions as high as 1.25 log CFU/g and 1.05 log CFU/g for TriNova and Sanova wash treatments, respectively. All other wash treatments resulted in population reductions of less than 1 log CFU/g. Chlorine (200 ppm), TriNova, Sanova, and acidic electrolyzed water were all equally effective against E. coli O157:H7 on Romaine, with log reductions of approximately 1 log CFU/g. The 20 ppm chlorine wash was as effective as the deionized water wash in reducing populations of E. coli O157:H7 on Romaine and Iceberg lettuce. Scanning electron microscopy indicated that E. coli O157:H7 that was incorporated into biofilms or located in damage lettuce tissue remained on the lettuce leaf, while individual cells on undamaged leaf surfaces were more likely to be washed away.

Induction of the nuclear factor HIF-1alpha in acetaminophen toxicity: evidence for oxidative stress.

Hypoxia inducible factor (HIF) controls the transcription of genes involved in angiogenesis, erythropoiesis, glycolysis, and cell survival. HIF-1alpha levels are a critical determinant of HIF activity. The induction of HIF-1alpha was examined in the livers of mice treated with a toxic dose of APAP (300 mg/kg i.p.) and sacrificed at 1, 2, 4, 8, and 12 h. HIF-1alpha was induced at 1-12 h and induction occurred prior to the onset of toxicity. Pre-treatment of mice with N-acetylcysteine (1200 mg/kg i.p.) prevented toxicity and HIF-1alpha induction. In further studies, hepatocyte suspensions were incubated with APAP (1 mM) in the presence of an oxygen atmosphere. HIF-1alpha was induced at 1 h, prior to the onset of toxicity. Inclusion of cyclosporine A (10 microM), an inhibitor of mitochondrial permeability transition, oxidative stress, and toxicity, prevented the induction of HIF-1alpha. Thus, HIF-1alpha is induced before APAP toxicity and can occur under non-hypoxic conditions. The data suggest a role for oxidative stress in the induction of HIF-1alpha in APAP toxicity.