184 research outputs found
Colouration and Colour Changes of the Fiddler Crab, Uca capricornis: A Descriptive Study
Colour changes in animals may be triggered by a variety of social and environmental factors and may occur over a matter of seconds or months. Crustaceans, like fiddler crabs (genus Uca), are particularly adept at changing their colour and have been the focus of numerous studies. However, few of these studies have attempted to quantitatively describe the individual variation in colour and pattern or their adaptive significance. This paper quantitatively describes the colour patterns of the fiddler crab Uca capricornis and their ability to change on a socially significant timescale. The most dramatic changes in colour pattern are associated with moulting. These ontogenetic changes result in a general reduction of the colour pattern with increasing size, although females are more colourful and variable than similarly-sized males. Uca capricornis are also capable of rapid colour changes in response to stress, but show no endogenous rhythms associated with the semilunar and tidal cycles commonly reported in other fiddler crabs. The extreme colour polymorphism and the relative stability of the colour patterns in Uca capricornis are consistent with their use in visually mediated mate recognition
Disentangling the Effects of Vapor Pressure Deficit and Soil Water Availability on Canopy Conductance in a Seasonal Tropical Forest During the 2015 El Niño Drought
Water deficit in the atmosphere and soil are two key interactive factors that constrain transpiration and vegetation productivity. It is not clear which of these two factors is more important for the water and carbon flux response to drought stress in ecosystems. In this study, field data and numerical modeling were used to isolate their impact on evapotranspiration (ET) and gross primary productivity (GPP) at a tropical forest site in Barro Colorado Island (BCI), Panama, focusing on their response to the drought induced by the El Niño event of 2015–2016. Numerical simulations were performed using a plant hydrodynamic scheme (HYDRO) and a heuristic approach that ignores stomatal sensitivity to leaf water potential in the Energy Exascale Earth System Model (E3SM) Land Model (ELM). The sensitivity of canopy conductance (Gs) to vapor pressure deficit (VPD) obtained from eddy-covariance fluxes and measured sap flux shows that, at both ecosystem and plant scale, soil water stress is more important in limiting Gs than VPD at BCI during the El Niño event. The model simulations confirmed the importance of water stress limitation on Gs, but overestimated the VPD impact on Gs compared to that estimated from the observations. We also found that the predicted soil moisture is less sensitive to the diversity of plant hydraulic traits than ET and GPP. During the dry season at BCI, seasonal ET, especially soil evaporation at VPD \u3e 0.42 kPa, simulated using HYDRO and ELM, were too strong and will require alternative parameterizations
Robust estimation of absorbing root surface distributions from xylem water isotope compositions with an inverse plant hydraulic model
Environmental Biolog
Point prevalence survey of antibiotic use and healthcare-associated infections in acute care hospitals: a comprehensive report from the Marche Region of Italy
Background: Healthcare Associated Infections (HAIs) and Antimicrobial Resistance (AMR) are serious health challenges. Point prevalence surveys (PPS) are valuable tools for monitoring HAIs and AMR.
Aim: To describe results of the ECDC-PPS 2022 dealing with the prevalence of HAIs, antimicrobial consumption, and associated factors, in acute care hospitals.
Methods: The present point-prevalence have been carried out survey in November 2022 in fourteen hospitals according to the protocol proposed by the European Centre for Disease Prevention and Control (ECDC). Multilevel logistic regression was performed using geographical area/hospital type as cluster variable to evaluate the factors independently associated with HAIs and antibiotics.
Results: The point prevalence of HAIs was 7.43%. Patients hospitalized for longer periods were more likely to have an HAI as well as those aged 15-44, with a rapidly fatal disease, intubated and with 1 or 2 devices. Antibiotics prevalence was 47.30%. Males, unknown McCabe scores, minimally invasive/non-NHSN surgery, patients with HAIs, hospitals with a higher alcohol hand rub consumption, hospitals with a higher amount of IPC personnel, geriatric wards and hospital with 300-600 beds were more likely to be under antimicrobial therapy.
Conclusion: This point prevalence survey provided valuable information on the prevalence of HAIs and antimicrobial consumption and variables associated. The high prevalence of HAIs highlights the need for improved infection control measure
Disturbance and the resilience of coupled carbon and nitrogen cycling in a north temperate forest
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96419/1/jgrg864.pd
Crayfish Recognize the Faces of Fight Opponents
The capacity to associate stimuli underlies many cognitive abilities, including recognition, in humans and other animals. Vertebrates process different categories of information separately and then reassemble the distilled information for unique identification, storage and recall. Invertebrates have fewer neural networks and fewer neural processing options so study of their behavior may reveal underlying mechanisms still not fully understood for any animal. Some invertebrates form complex social colonies and are capable of visual memory–bees and wasps, for example. This ability would not be predicted in species that interact in random pairs without strong social cohesion; for example, crayfish. They have chemical memory but the extent to which they remember visual features is unknown. Here we demonstrate that the crayfish Cherax destructor is capable of visual recognition of individuals. The simplicity of their interactions allowed us to examine the behavior and some characteristics of the visual features involved. We showed that facial features are learned during face-to-face fights, that highly variable cues are used, that the type of variability is important, and that the learning is context-dependent. We also tested whether it is possible to engineer false identifications and for animals to distinguish between twin opponents
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