Dynamical transitions in a pollination--herbivory interaction

Plant-pollinator associations are often seen as purely mutualistic, while in reality they can be more complex. Indeed they may also display a diverse array of antagonistic interactions, such as competition and victim--exploiter interactions. In some cases mutualistic and antagonistic interactions are carried-out by the same species but at different life-stages. As a consequence, population structure affects the balance of inter-specific associations, a topic that is receiving increased attention. In this paper, we developed a model that captures the basic features of the interaction between a flowering plant and an insect with a larval stage that feeds on the plant's vegetative tissues (e.g. leaves) and an adult pollinator stage. Our model is able to display a rich set of dynamics, the most remarkable of which involves victim--exploiter oscillations that allow plants to attain abundances above their carrying capacities, and the periodic alternation between states dominated by mutualism or antagonism. Our study indicates that changes in the insect's life cycle can modify the balance between mutualism and antagonism, causing important qualitative changes in the interaction dynamics. These changes in the life cycle could be caused by a variety of external drivers, such as temperature, plant nutrients, pesticides and changes in the diet of adult pollinators. Abstract Keywords: mutualism, pollination, herbivory, insects, stage-structure, oscillationsComment: 20 pages, 7 main figures, 2 appendix figure

Effectiveness of a Surgery Admission Unit for patients undergoing major elective surgery in a tertiary university hospital

<p>Abstract</p> <p>Background</p> <p>The increasing demand on hospitalisation, either due to elective activity from the waiting lists or due to emergency admissions coming from the Emergency Department (ED), requires looking for strategies that lead to effective bed management. The aim of this study was to evaluate the effectiveness of a surgery admission unit for major elective surgery patients who were admitted for same-day surgery.</p> <p>Methods</p> <p>We included all patients admitted for elective surgery in a university tertiary hospital between the 1st of September and the 31st of December 2006, as well as those admitted during the same period of 2008, after the introduction of the Surgery Admission Unit. The main outcome parameters were global length of stay, pre-surgery length of stay, proportion of patients admitted the same day of the surgery and number of cancellations. Differences between the two periods were evaluated by the T-test and Chi-square test. Significance at P < 0.05 was assumed throughout.</p> <p>Results</p> <p>We included 6,053 patients, 3,003 during 2006 and 3,050 patients during 2008. Global length of stay was 6.2 days (IC 95%:6.4-6) in 2006 and 5.5 days (IC 95%:5.8-5.2) in 2008 (p < 0.005). Pre-surgery length of stay was reduced from 0.46 days (IC 95%:0.44-0.48) in 2006 to 0.29 days (IC 95%:0.27-0.31) in 2008 (p < 0.005). The proportion of patients admitted for same-day surgery was 67% (IC 95%:69%-65%) in 2006 and 76% (IC 95%:78%-74%) in 2008 (p < 0.005). The number of cancelled interventions due to insufficient preparation was 31 patients in 2006 and 7 patients in 2008.</p> <p>Conclusions</p> <p>The implementation of a Surgery Admission Unit for patients undergoing major elective surgery has proved to be an effective strategy for improving bed management. It has enabled an improvement in the proportion of patients admitted on the same day as surgery and a shorter length of stay.</p

Influence of essential oils (cinnamaldehyde and garlic oil) on rumen fermentation, feeding 1 behavior and performance of lactating dairy cattle

Two experiments were conducted to study the effects of Next Enhance® 300 (NE300; cinnamaldehyde and garlic oil encapsulated product) on rumen fermentation and milk production of dairy cows. In experiment 1, batch cultures of mixed rumen micro-organisms were used to study the effects of increasing concentrations of NE300 (0, 200, 300, and 400 mg/L) on ruminal fermentation in 24 h in vitro incubations. All tested doses decreased (P < 0.05) methane production, but the dose of 400 mg/L also reduced the production of volatile fatty acid (VFA). The addition of NE300 at 300 mg/L produced the most beneficial effects, reducing methane production, acetate proportion, and ammonia-N concentration, and increasing propionate proportion compared with CON, without affecting total VFA production. These results would indicate a potentially greater supply of energy for the host animal. In experiment 2, sixteen lactating dairy cows (8 rumen-cannulated) participated in a switch-back design with three 4-wk periods and 2 treatments: control (CON, unsupplemented) and NE300 (300 mg NE300/cow/d). Milk yield response was affected by a 3-way interaction among treatment, parity, and days on treatment; after 15 d on treatment, multiparous cows on NE300 produced more milk (approximately additional 3 kg/d) than multiparous cows on CON. Total rumen VFA concentrations tended (P = 0.06) to be greater in NE300 than in CON when rumen fermentation kinetics were evaluated at the end of each period (day 28). It is concluded that NE300 modifies ruminal fermentation resulting in increased milk yield in multiparous lactating dairy cows after 15 d of adaptation

The juvenile hormone analogue, pyriproxifen, alters protein and fat composition of Tenebrio molitor larvae

Maximising the yield of product from livestock is common practice in the agriculture industry and there is potential to extend this practice to the emerging insect industry, to produce high-quality, sustainable protein. Tenebrio molitor larvae, commonly called yellow mealworms, were fed for 28 days on wheat bran containing the juvenile hormone analogue, pyriproxifen at either 2 mg pyriproxifen/kg wheat bran (JH-PL) or 15 mg pyriproxifen/kg wheat bran (JH-PH). As expected, pupation was inhibited in both pyriproxifen treated groups and significant changes in nutritional composition were observed. Pyriproxifen treated mealworms had a higher protein content per 100 grams of dried material, while fat content was reduced 68% in JH-PH compared to control. These changes were associated with an increase in moisture content and reduction in energy content. The fatty acid profile of extracted fat also displayed significant alterations, with pyriproxifen treated mealworms showing an increase in proportions of saturated fatty acids, reduction in oleic acid but no effect on linoleic acid. The amino acid composition also exhibited a change in composition as a result of pyriproxifen treatment, including an increase in the essential amino acid, lysine, in JH-PH treated mealworms. This change in amino acid profile was associated with a change in the protein composition as observed on SDS-PAGE, with the appearance of a new band identified as the egg-yolk protein, vitellogenin, which has lipid-transporter activity. Hence, pyriproxifen treatment of mealworms has a repartitioning effect, resulting in an increase in the proportion of protein and a decrease in fat on a dry matter basis, demonstrating that mealworm nutrient composition can be manipulated to provide a higher value feed ingredient

2018 MAX-C/ExoMars Mission: The Orleans Mars-Analogue Rock Collection for Instrument Testing

International audienceIn order to reply to the exobiological goals of the 2018 MAX-C/ExoMars mission, the Orléans-OSUC analogue rock collection and database contains well characterised Mars analogue rocks and minerals for use in instrument testing and in situ missions

Changes in nutrient composition and gene expression in growing mealworms (Tenebrio molitor)

Insects are of high interest as a sustainable source of nutrients to be included in the food production system. The larvae of Tenebrio molitor, commonly known as yellow mealworms (MW), have a high protein content, which means potential applications in the animal feed and human food sectors. However, previous reports have shown considerable variability in the nutrient composition of mealworms, which may in part, be due to harvesting at different developmental stages. A better understanding of the regulation of composition during development would potentially facilitate future attempts to manipulate nutrient content, perhaps through gene editing, to maximize commercial value. In the present study, mealworms were harvested at various time points within a 24 day period leading up to the start of pupation. At the earliest time points (between days −24 and −17), a 44% increase in fat content was seen, which was maintained throughout the rest of development. By day −12, protein content fell by 12%, a change that was also maintained. Throughout development there was a change in fatty acid composition, with a shift from oleic acid being the major fatty acid at day −24, to linoleic acid being predominant at later time points. In an attempt to better understand the genetic basis of these changes, an analysis of the transcriptome was undertaken. In the absence of a specific annotated genome for the mealworm, an Affymetrix GeneChip microarray for Drosophila was utilized. The hybridisation of RNA extracted from five developmental stages (larvae and pupae) showed differential gene expression; and some potential orthologs were identified which may be involved in regulating nutrient composition during development. However, we were unable to identify a significant proportion of the most highly regulated genes, highlighting the need for a fully annotated mealworm genome

Reacción en cadena de la polimerasa para la detección del VPH en mucosa bucal

Varias patologías de la mucosa bucal y de los huesos maxilares han sido relacionadas con el Virus Papiloma Humano (VPH). Aquellas conforman un amplio espectro: benignas, potencialmente malignas y malignas. Las más llamativas son las lesiones de estirpe odontogénica. El ameloblastoma es un tumor epitelial odontogénico localmente agresivo de frecuencia relativa de localización maxilar con la posibilidad de ser periférico. El carcinoma a células escamosas es la neoplasia más frecuente de la mucosa bucal. Como el VPH es un virus epiteliotrópico, sus funciones y la síntesis viral de su ADN se realiza a nivel de las células del estrato espinoso. Si bien la vía de contacto con el virus es la transmisión sexual, no puede dejarse de lado la transmisión vertical. Por este motivo existen lesiones pediátricas que se asociaron al virus tanto de bajo como de alto riesgo para la transformación a la malignidad. La técnica de reacción en cadena de la polimerasa (PCR) sigue demostrando su alta especificidad y sensibilidad para la identificación y sobre todo la genotipificación viral.Facultad de Odontologí

Reacción en cadena de la polimerasa para la detección del VPH en mucosa bucal

Varias patologías de la mucosa bucal y de los huesos maxilares han sido relacionadas con el Virus Papiloma Humano (VPH). Aquellas conforman un amplio espectro: benignas, potencialmente malignas y malignas. Las más llamativas son las lesiones de estirpe odontogénica. El ameloblastoma es un tumor epitelial odontogénico localmente agresivo de frecuencia relativa de localización maxilar con la posibilidad de ser periférico. El carcinoma a células escamosas es la neoplasia más frecuente de la mucosa bucal. Como el VPH es un virus epiteliotrópico, sus funciones y la síntesis viral de su ADN se realiza a nivel de las células del estrato espinoso. Si bien la vía de contacto con el virus es la transmisión sexual, no puede dejarse de lado la transmisión vertical. Por este motivo existen lesiones pediátricas que se asociaron al virus tanto de bajo como de alto riesgo para la transformación a la malignidad. La técnica de reacción en cadena de la polimerasa (PCR) sigue demostrando su alta especificidad y sensibilidad para la identificación y sobre todo la genotipificación viral.Facultad de Odontologí