1,794 research outputs found

    Honeybees learn floral odors while receiving nectar from foragers within the hive

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    Abstract Recent studies showed that nectar odors brought back by honeybee foragers can be learned associatively inside the hive. In the present study, we focused on the learning abilities of bees, which directly interact via trophallaxis with the incoming nectar foragers: the workers that perform nectar-receiving tasks inside the hive. Workers that have received food directly from foragers coming back from a feeder offering either unscented or scented sugar solution [phenylacetaldehyde (PHE) or nonanal diluted] were captured from two observational hives, and their olfactory memories were tested using the proboscis exten-sion response paradigm. Bees that have received scented solution from incoming foragers showed significantly increased response frequencies for the corresponding solution odor in comparison with those that have received unscented solution. No differences in the response frequen-cies were found between food odors and colonies. The results indicate that first-order receivers learn via trophal-laxis the association between the scent and the sugar solution transferred by incoming foragers. The implications of these results should be considered at three levels: the operational cohesion of bees involved in foraging-related tasks, the information propagation inside the hive related to the floral type exploited, and the putative effect of these memories on future preferences for resources

    Update in laparoscopic approach to acute mesenteric ischemia

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    AMI is an uncommon but serious disease often associated with a bad prognosis, associated with occlusion of Superior Mesenteric Artery (SMA) for embolism or thrombosis (67.2%), mesenteric venous thrombosis (15.7%), and non-occlusive mesenteric ischemia (15.4%). Clinical markers are often aspecific and symptoms low suggestive. The gold standard for the diagnosis is multidetector CT Angiography (CTA) with sensibility of 93.3% and specificity of 95.9%. Abdominal exploration could be useful to confirm cases of AMI without signs of SMA occlusion at CTA. Few reports have been found on the diagnostic role of Exploratory Laparoscopy. To increase the sensibility of laparoscopy in the diagnosis of AMI in the last ten years, some studies had shown the possibility of using fluorescein to underline the bowel areas of interest by ischemia. The best of laparoscopy in AMI diagnosis remains the second look and bedside use (directly in ICU when possible) overall in patients with Aortic dissection type B (preferable chronic type). In a limited number of cases, it is possible to evaluate bowel perfusion laparoscopically and at the same time perform a laparoscopical bowel resection of residual ischemic segments. However, laparoscopic primary access overall in AoD is an important tool for leading therapeutic decision and timing. Finally, laparoscopy may be a feasible alternative to CTA in patients with kidney failure that contraindicates injection of iodate CT contrast medium

    Family functioning but not social capital is associated with better mental health in adolescents affected by violence and displacement by armed conflict in Colombia

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    Background: The effect of the Colombian armed conflict on the mental health of adolescents is still poorly understood. Aims: Given social interventions are most likely to inform policy, we tested whether two potential intervention targets, family functioning and social capital, were associated with mental health in Colombian adolescents, and whether this was moderated by experience of violence and displacement. Methods: We examined the cross-sectional association between family functioning, cognitive social capital, structural social capital and 12-month prevalence of Composite International Diagnostic Interview (CIDI) diagnosed psychiatric disorder, using data on 12 to 17-year-old adolescents (N = 1,754) from the 2015 National Mental Health Survey of Colombia, a nationally representative epidemiological study. We tested whether associations survived cumulative adjustment for demographic confounders, experience of non-specific violence and harm and displacement by armed conflict. Results: Neither structural nor cognitive social capital were associated with better mental health. Better family functioning was associated with reduced risk of poor mental health in an unadjusted analysis (OR 0.90 [0.85–0.96]), and after cumulative adjustments for demographic confounders (OR 0.91 [0.86–0.97]), non-specific violence and harm (OR 0.91 [0.86–0.97]) and social capital variables (OR 0.91 [0.85–0.97]). In the final model, each additional point on the family APGAR scale was associated with a 9% reduced odds of any CIDI diagnosed disorder in the last 12 months. Conclusions: Better family functioning was associated with better mental health outcomes for all adolescents. This effect remained present in those affected by the armed conflict even after accounting for potential confounders

    The Effect of Tear Supplementation on Ocular Surface Sensations during the Interblink Interval in Patients with Dry Eye.

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    PURPOSE: To investigate the characteristics of ocular surface sensations and corneal sensitivity during the interblink interval before and after tear supplementation in dry eye patients. METHODS: Twenty subjects (41.88+/-14.37 years) with dry eye symptoms were included in the dry eye group. Fourteen subjects (39.13+/-11.27 years) without any clinical signs and/or symptoms of dry eye were included in the control group. Tear film dynamics was assessed by non-invasive tear film breakup time (NI-BUT) in parallel with continuous recordings of ocular sensations during forced blinking. Corneal sensitivity to selective stimulation of corneal mechano-, cold and chemical receptors was assessed using a gas esthesiometer. All the measurements were made before and 5 min after saline and hydroxypropyl-guar (HP-guar) drops. RESULTS: In dry eye patients the intensity of irritation increased rapidly after the last blink during forced blinking, while in controls there was no alteration in the intensity during the first 10 sec followed by an exponential increase. Irritation scores were significantly higher in dry eye patients throughout the entire interblink interval compared to controls (p0.05). CONCLUSION: Ocular surface irritation responses due to tear film drying are considerably increased in dry eye patients compared to normal subjects. Although tear supplementation improves the protective tear film layer, and thus reduce unpleasant sensory responses, the rapid rise in discomfort is still maintained and might be responsible for the remaining complaints of dry eye patients despite the treatment

    Extraction and Fractionation of Pigments from Saccharina latissima (Linnaeus, 2006) Using an Ionic Liquid plus Oil plus Water System

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    There is a strong industrial interest in the development of greener and more sustainable processes based on the use of renewable resources, and a biorefinery based on marine resources, such as macroalgae, stands as a major opportunity toward that end. In this work, Saccharina latissima (Linnaeus), a brown macroalga, was used as a source of pigments to develop an integrated platform that is able to promote the extraction and separation of chlorophyll and fucoxanthin in one single step. The process was studied, and its operational conditions were optimized with yields of extraction of chlorophyll and fucoxanthin of 4.93 ± 0.22 mgchl·gdry biomass–1 and 1956 ± 84 ÎŒgfuco·gdry biomass–1, respectively. These results were achieved with extraction systems composed of 84% of an aqueous solution of a tensioactive phosphonium-based ionic liquid (IL) at 350 mM + 16% of sunflower oil, during 40 min, using a solid–liquid ratio of 0.017 gdry biomass·mLsolvent–1. After the separation of both aqueous IL-rich and oil-rich phases, the IL content in both phases was investigated, the oil phase being free of IL. Envisioning the industrial potential of the process developed in this work, the recovery of the IL from the aqueous IL-rich phase of the initial system was attempted by a back-extraction using organic solvents immiscible in water, being shown that 82% of the IL can be recovered and reused in new cycles of extraction. The environmental and economic impacts of the final process proposed for the extraction and fractionation of chlorophyll and fucoxanthin were evaluated. Different scenarios were considered, but summing up the main results, the solvents’ recycling allowed better results, proving the economic and environmental viability of the overall process

    Corneal Sensitivity and Dry Eye Symptoms in Patients with Keratoconus.

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    PURPOSE: To investigate corneal sensitivity to selective mechanical, chemical, and thermal stimulation and to evaluate their relation to dry eye symptoms in patients with keratoconus. METHODS: Corneal sensitivity to mechanical, chemical, and thermal thresholds were determined using a gas esthesiometer in 19 patients with keratoconus (KC group) and in 20 age-matched healthy subjects (control group). Tear film dynamics was assessed by Schirmer I test and by the non-invasive tear film breakup time (NI-BUT). All eyes were examined with a rotating Scheimpflug camera to assess keratoconus severity. RESULTS: KC patients had significatly decreased tear secretion and significantly higher ocular surface disease index (OSDI) scores compared to controls (5.3+/-2.2 vs. 13.2+/-2.0 mm and 26.8+/-15.8 vs. 8.1+/-2.3; p0.05). The mean threshold for selective mechanical (KC: 139.2+/-25.8 vs. control: 109.1+/-24.0 ml/min), chemical (KC: 39.4+/-3.9 vs. control: 35.2+/-1.9%CO2), heat (KC: 0.91+/-0.32 vs. control: 0.54+/-0.26 Delta degrees C) and cold (KC: 1.28+/-0.27 vs. control: 0.98+/-0.25 Delta degrees C) stimulation in the KC patients were significantly higher than in the control subjects (p0.05), whereas in the control subjects both mechanical (r = 0.52, p = 0.02), chemical (r = 0.47, p = 0.04), heat (r = 0.26, p = 0.04) and cold threshold (r = 0.40, p = 0.03) increased with age. In the KC group, neither corneal thickness nor tear flow, NI-BUT or OSDI correlated significantly with mechanical, chemical, heat or cold thresholds (p>0.05 for all variables). CONCLUSIONS: Corneal sensitivity to different types of stimuli is decreased in patients with keratoconus independently of age and disease severity. The reduction of the sensory input from corneal nerves may contribute to the onset of unpleasant sensations in these patients and might lead to the impaired tear film dynamics

    IgG antibodies against phospholipase A2 from Crotalus durissus terrificus: cross-reaction with venoms from Bothrops species from Argentina

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    We examined the ability of IgG anti-crotalic PLA2 to cross-react with Bothrops spp. venoms, from snakes found in the northeast of Argentina. Immunoblotting and ELISA tests showed that IgG anti-crotalic PLA2 recognize antigens of bothropic venoms. Indirect hemolytic activity tests showed that the quantity of antibodies that neutralized 50% of Crotalus durissus terrificus venom (ED50: 2.1 mg IgG anti-crotalic PLA2/100 ”g of venom) were also able to neutralize venom from other snakes in the following proportion: 34% of B. alternatus, 18% of B. diporus and 12% of B. jararacussu. Likewise, direct PLA2 activity neutralization tests showed a similar cross-neutralization pattern including 56% of B. alternatus, 29% of B. diporus and 30% of B. jararacussu. In addition, in a myotoxic activity neutralization test, measured by plasma activity of creatine kinase, 35% of B. alternatus venom and 26% of B. diporus venom were neutralized, while no neutralization was detected with B. jararacussu venom. This study presents original data concerning cross-reactions between bothropic venoms from Argentina and IgG anti-crotalic PLA2. Our results suggest that anti-crotalic PLA2 antibodies should not be used to neutralize PLA2 activity of B. alternatus, B. diporus and especially B. jararacussu venoms; nor to enrich commercial antivenoms against these Bothrops species

    Co-opetition models for governing professional football

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    In recent years, models for co-creating value in a business-to-business context have often been examined with the aim of studying the strategies implemented by and among organisations for competitive and co-operative purposes. The traditional concepts of competition and co-operation between businesses have now evolved, both in terms of the sector in which the businesses operate and in terms of the type of goods they produce. Many researchers have, in recent times, investigated the determinants that can influence the way in which the model of co-opetition can be applied to the football world. Research interest lies in the particular features of what makes a good football. In this paper, the aim is to conduct an analysis of the rules governing the “football system”, while also looking at the determinants of the demand function within football entertainment. This entails applying to football match management the co-opetition model, a recognised model that combines competition and co-operation with the view of creating and distributing value. It can, therefore, be said that, for a spectator, watching sport is an experience of high suspense, and this suspense, in turn, depends upon the degree of uncertainty in the outcome. It follows that the rules ensuring that both these elements can be satisfied are a fertile ground for co-operation between clubs, as it is in the interest of all stakeholders to offer increasingly more attractive football, in comparison with other competing products. Our end purpose is to understand how co-opetition can be achieved within professional football
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