301 research outputs found

    The costs of kleptoparasitism: a study of mixed-species seabird breeding colonies

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    This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.Mixed-species assemblages are common in nature, providing mutual benefits to associating species including anti-predator advantages or resource facilitation. However, associating with other species may also impose costs through kleptoparasitism (food theft). Identification of these costs, and how they vary when different species breed alongside one another, is essential to understand the payoffs of mixed-species assemblages. We explore the costs of kleptoparasitism for greater crested terns Thalasseus bergii provisioning offspring at a single-species colony, where individuals suffer kleptoparasitism from conspecifics, and at a mixed colony where terns breed alongside Hartlaub’s gulls Chroicocephalus hartlaubii and are vulnerable to both intra and interspecific kleptoparasitism. Gull presence likely contributes to increases in both kleptoparasitic attacks and the proportion of prey lost or stolen during provisioning, relative to the single-species colony. Provisioning adults suffered additional energetic costs in response to gull kleptoparasitism, requiring more attempts to deliver prey, taking longer to do so, and swallowing more prey (to the detriment of their offspring). Gulls also appear to increase the duration of tern vulnerability to kleptoparasitism, because they continued to steal food from adults and chicks after precocial chicks left the nest, when intraspecific kleptoparasitism is negligible. Terns breeding in a mixed colony, therefore, suffer direct and indirect costs through decreased provisioning and increased provisioning effort, which may ultimately affect reproductive success, resulting in colony decline where kleptoparasitism is frequent. This study illustrates how forming a mixed-species seabird breeding assemblage has costs as well as benefits, potentially fluctuating between a parasitic and a mutualistic relationship.This work was supported by a Department of Science and TechnologyCentre of Excellence grant to the FitzPatrick Institute of African Ornithology. R.B.S.  was supported by a fellowship from the Leiden Conservation Foundation. This research was approved by SANParks (CONM1182), the Department of Environmental Affairs (RES2013/24, RES2014/83, and RES2015/65) and the animal ethics committee of the University of Cape Town (2013/V3/TC)

    A non-invasive approach to estimate the energetic requirements of an increasing seabird population in a perturbed marine ecosystem

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    This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this record.There is a growing desire to integrate the food requirements of predators living in marine ecosystems impacted by humans into sustainable fisheries management. We used non- invasive video-recording, photography and focal observations to build time-energy budget models and to directly estimate the fish mass delivered to chicks by adult greater crested terns Thalasseus bergii breeding in the Benguela ecosystem. Mean modelled adult daily food intake increased from 140.9 g·d−1 of anchovy Engraulis capensis during incubation to 171.7g·d−1 and 189.2 g·d−1 when provisioning small and large chicks, respectively. Modelled prey intake expected to be returned to chicks was 58.3 g·d−1 (95% credible intervals: 44.9–75.8 g·d−1) over the entire growth period. Based on our observations, chicks were fed 19.9 g·d−1 (17.2–23.0 g·d−1) to 45.1 g·d−1 (34.6–58.7 g·d−1 25 ) of anchovy during early and late provisioning, respectively. Greater crested terns have lower energetic requirements at the individual (range: 15–34%) and population level (range: 1–7%) than the other Benguela endemic seabirds that feed on forage fish. These modest requirements – based on a small body size and low flight costs – coupled with foraging plasticity have allowed greater crested terns to cope with changing prey availability, unlike the other seabirds species using the same exploited prey base.Our research was supported by a Department of Science and Technology-National Research Foundation Centre of Excellence grant to the FitzPatrick Institute of African Ornithology, the Leiden Conservation Foundation (RBS) and our institutes. Robben Island Museum provided logistical support and access to the tern colonies

    Chemical composition of essential oils from Pantelleria Island autochthonous and naturalized spices and evaluation of their individual and combined antimicrobial activities

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    In this study, the antimicrobial activity of the essential oils (EOs) from Origanum majorana L. and Rosmarinus officinalis L. growing in Pantelleria (Sicily, Italy) were tested alone and in combination against some prokaryotic and eukaryotic food-borne pathogens. The chemical composition of the EOs as well as the minimum inhibitory concentrations (MIC) against the most sensitive strains were also determined. Both EOs showed interesting antimicrobial effects against all bacteria and yeasts tested. MIC was in the range 1.25-2.50 mu l/ml. Interestingly, O. majorana was particularly rich in thymol acetate, while carvacrol was present at very low percentages. Also R. officinalis EOs composition was different from rosemary collected in different areas, as being particularly rich in caryophyllene. Furthermore, the antimicrobial activity of the combination of O. majorana and R. officinalis EOs indicated their potential as food biopreservatives

    A large factory-scale application of selected autochthonous lactic acid bacteria for PDO Pecorino Siciliano cheese production

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    The main hypothesis of this study was that the autochthonous lactic acid bacteria (LAB) selected for their dairy traits are able to stabilize the production of PDO (Protected Denomination of Origin) Pecorino Siciliano cheese, preserving its typicality. The experimental plan included the application of a multistrain lactic acid bacteria (LAB) culture, composed of starter (Lactococcus lactis subsp. lactis CAG4 and CAG37) and non starter (Enterococcus faecalis PSL71, Lactococcus garviae PSL67 and Streptococcus macedonicus PSL72) strains, during the traditional production of cheese at large scale level in six factories located in different areas of Sicily. The cheese making processes were followed from milk to ripened cheeses and the effects of the added LAB were evaluated on the microbiological, chemico-physical and sensorial characteristics of the final products. Results highlighted a high variability for all investigated parameters and the dominance of LAB cocci in bulk milk samples. The experimental curds showed a faster pH drop than control curds and the levels of LAB estimated in 5-month ripened experimental cheeses (7.59 and 7.27 Log CFU/g for rods and cocci, respectively) were higher than those of control cheeses (7.02 and 6.61 Log CFU/g for rods and cocci, respectively). The comparison of the bacterial isolates by randomly amplified polymorphic DNA (RAPD)-PCR evidenced the dominance of the added starter lactococci over native milk and vat LAB, while the added non starter LAB were found at almost the same levels of the indigenous strains. The sensory evaluation showed that the mixed LAB culture did not influence the majority of the sensory attributes of the cheeses and that each factory produced cheeses with unique characteristics. Finally, the multivariate statistical analysis based on all parameters evaluated on the ripened cheeses showed the dissimilarities and the relationships among cheeses. Thus, the main hypothesis of the work was accepted since the quality parameters of the final cheeses were stabilized, but all cheeses maintained their local typicality

    The Ursinus Weekly, May 2, 1974

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    Two faculty members receive promotions • Committee of USGA proposes rule changes • Henry and Perreten get study grants • Dr. Parsons and Dr. Snyder to run Pa. Dutch course • Japanese will join U.C. summer school • U.C. to honor Rep. Ware at commencement • Dave Liscom to attend St. Andrews • Editorial: So what else is new?; Say something good • Italian philosopher is reborn • Alumni corner: The Ruby in debt • The ghost of Ursinus past • Ursinus students view unicorns • New 3-plus-3 plan: Degree in 3 years • Pi Gamma Mu names 10 to membership • Brazilians say “Saudade!” • U.C. students plan summers in Europe • Review: Springsteen’s rock rocks U.C. campus • ‘Chap’ resigns his U.C posts • Lacrosse trials select players • Bear runners looking good • Faculty focus: Georgia Ferrell leads winning gymnasts • Baseball squad facing tough competition • Two Ursinus basketball stars honoredhttps://digitalcommons.ursinus.edu/weekly/1015/thumbnail.jp

    KNOWLEDGE AND VIEWPOINTS ON THE EFFECTS OF CORRUPTION ON HEALTHCARE: A SURVEY CONDUCTED AMONG STUDENTS OF PALERMO UNIVERSITY MEDICAL SCHOOL, ITALY

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    Corruption affects healthcare effectiveness and efficiency and limits equity in access to health services. Aim of the survey was to document knowledge and viewpoints on the impact of corruption on healthcare system in a sample of students attending pre-lauream healthcare professional courses at Palermo University Medical school and to evaluate any improvement in their awareness on this topic after a dedicated multidisciplinary educational intervention. An anonymous questionnaire was administered to students before and after the intervention. Absolute and relative frequency of correct and incorrect answers was computed. Chi-squared test was used to compare answers given before and after the educational intervention. Approximately less than a quarter of the respondents were able to correctly estimate impact of corruption, inappropriateness and waste in healthcare on NHS. The study documented how improving students\u2019 knowledge of the impact of corruption in the healthcare system could represent a possible strategy to prevent corruption in healthcare

    Transcriptomics and metabolomics integration reveals redox-dependent metabolic rewiring in breast cancer cells

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    Rewiring glucose metabolism toward aerobic glycolysis provides cancer cells with a rapid generation of pyruvate, ATP, and NADH, while pyruvate oxidation to lactate guarantees refueling of oxidized NAD+ to sustain glycolysis. CtPB2, an NADH-dependent transcriptional co-regulator, has been proposed to work as an NADH sensor, linking metabolism to epigenetic transcriptional reprogramming. By integrating metabolomics and transcriptomics in a triple-negative human breast cancer cell line, we show that genetic and pharmacological down-regulation of CtBP2 strongly reduces cell proliferation by modulating the redox balance, nucleotide synthesis, ROS generation, and scavenging. Our data highlight the critical role of NADH in controlling the oncogene-dependent crosstalk between metabolism and the epigenetically mediated transcriptional program that sustains energetic and anabolic demands in cancer cells

    A 3D Human Posture Approach for Activity Recognition Based on Depth Camera

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    Human activity recognition plays an important role in the context of Ambient Assisted Living (AAL), providing useful tools to improve people quality of life. This work presents an activity recognition algorithm based on the extraction of skeleton joints from a depth camera. The system describes an activity using a set of few and basic postures extracted by means of the X-means clustering algorithm. A multi-class Support Vector Machine, trained with the Sequential Minimal Optimization is employed to perform the classification. The system is evaluated on two public datasets for activity recognition which have different skeleton models, the CAD-60 with 15 joints and the TST with 25 joints. The proposed approach achieves precision/recall performances of 99.8 % on CAD-60 and 97.2 %/91.7 % on TST. The results are promising for an applied use in the context of AAL
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