Economic decision making in ants - A comparative approach to investigating individual decision making in ants

Social insects have the striking ability to collectively choose the most profitable among all available options, even without a central control. This extremely successful system is built on the subjective decisions of many individuals. By following a comparative approach, integrating theories from behavioural economics and consumer psychology, this thesis provides deep insights into individual decision making in ants and how it is affected by factors apparently independent of an option’s absolute value. In chapter 2, we demonstrated that expectations of upcoming reward qualities affect value perception in individual ant foragers and provide, to our knowledge, the first relative value curve for an invertebrate, covering a wide range of reward expectations. Specifically, we show that medium quality food is rated as higher quality by ants which expected to find poor quality food based on previous experience (positive incentive contrast) compared to ants which expected good food and were thus disappointed (negative incentive contrast). Through association formation, ants can learn to predict reward qualities based on odour cues. By confronting ants with medium food along with odours previously associated to good or poor food, in chapter 3, we show that odour labels can affect perceived value, and thus diminish contrast effects, by adding a value assigned to them in the past. The presence of other nestmates often leads to compensatory behaviour aimed at preventing crowding on trails and at food sources. Chapter 4 reveals that experienced foragers not only downregulate their recruitment effort to prevent crowding, but also prefer unoccupied over occupied food sources, allowing uninformed recruits to focus on already established food sources. Ants, as central-place foragers, strongly discount time to maximize their individual food intake rate. We demonstrate in chapter 5 that experienced foragers can forego low quality food close to the nest in favour of good food far-away, showing self-control. If the close food is of similar or identical quality, however, they ignore far-away food, displaying impulsivity. Finally, despite many factors affecting value perception being described, the genetic and neuronal mechanisms underlying relative value perception are widely unknown. Thus in chapter 6 presents multiple attempts to train Drosophila fruit flies to expect different reward qualities depending on previously associated odours, a prerequisite for revealing these mechanisms. However, flies did not show a preference for one of the associated odour cues. Taking an interdisciplinary approach, and thus benefiting from the work of behavioural economists and comparative and consumer psychologists, allowed us to gain fresh insights into the behaviour and cognition of individual ant foragers. This work reveals a broad spectrum of factors affecting value perception in ants. These factors in turn allow ants to adapt their foraging decisions to a changing environment and thus maximize colony-level food intake

Fab Fridays: Fostering Elementary Teacher Candidate Preparation Through Informal STEM Events

Informal STEM learning opportunities offered outside of the structured school day have been gaining popularity in today’s STEM-oriented culture. These are venues where children and their families gather to engage and explore in science, technology, engineering, and math —together. For a number of years, faculty from the College of Education at Tennessee Tech University have been promoting these events for the local community, free of charge, to encourage and foster a love for STEM Education. Methods professors recognize these events as golden opportunities for teacher candidates enrolled to learn about STEM content while aiding in the development of their pedagogy. In addition to the experience gained from working with the materials at various STEM stations, teacher candidates have the opportunity to interact with children and families. Furthermore, teacher candidates interact with faculty and students from other academic areas such as nursing, engineering, biology and physics, as well as content specialists from the community. These interactions help to bolster preservice teachers’ skills and feelings of self-efficacy toward communicating with families and teaching STEM concepts. The informal STEM learning events offer a variety of experiences often unavailable during the school day and promote the social, emotional, and intellectual skills of our teacher candidates, as well as, those of the children and families who attend

Positive and negative incentive contrasts lead to relative value perception in ants

Humans usually assess things not according to their absolute value, but relative to reference points - a main tenant of Prospect Theory. For example, people rate a new salary relative to previous salaries and salaries of their peers, rather than absolute income. We demonstrate a similar effect in an insect: ants expecting to find low-quality food showed higher acceptance of medium-quality food than ants expecting medium quality, and vice versa for high expectations. Further experiments demonstrate that these contrast effects arise from cognitive rather than mere sensory or pre-cognitive perceptual causes. Social information gained inside the nest can also serve as a reference point: the quality of food received from other ants affected the perceived value of food found later. Value judgement is a key element in decision making, and thus relative value perception strongly influences which option is chosen and ultimately how all animals make decisions

Severe infections of Panton-Valentine leukocidin positive Staphylococcus aureus in children

Infections caused by Panton-Valentine leukocidin-positive Staphylococcus aureus (PVL-SA) mostly present as recurrent skin abscesses and furunculosis. However, life-threatening infections (eg, necrotizing pneumonia, necrotizing fasciitis, and osteomyelitis) caused by PVL-SA have also been reported.We assessed the clinical phenotype, frequency, clinical implications (surgery, length of treatment in hospitals/intensive care units, and antibiotic treatments), and potential preventability of severe PVL-SA infections in children.Total, 75 children treated for PVL-SA infections in our in- and outpatient units from 2012 to 2017 were included in this retrospective study.Ten out of 75 children contracted severe infections (PVL-methicillin resistant S aureus n = 4) including necrotizing pneumonia (n = 4), necrotizing fasciitis (n = 2), pyomyositis (n = 2; including 1 patient who also had pneumonia), mastoiditis with cerebellitis (n = 1), preorbital cellulitis (n = 1), and recurrent deep furunculosis in an immunosuppressed patient (n = 1). Specific complications of PVL-SA infections were venous thrombosis (n = 2), sepsis (n = 5), respiratory failure (n = 5), and acute respiratory distress syndrome (n = 3). The median duration of hospital stay was 14 days (range 5-52 days). In 6 out of 10 patients a history suggestive for PVL-SA colonization in the patient or close family members before hospital admission was identified.PVL-SA causes severe to life-threatening infections requiring lengthy treatments in hospital in a substantial percentage of symptomatic PVL-SA colonized children. More than 50% of severe infections might be prevented by prompt testing for PVL-SA in individuals with a history of abscesses or furunculosis, followed by decolonization measures

Evaluation of the Effect of Nandrolone Decanoate on Experimental Spinal Cord Injury in Rats

Background: Acute spinal cord injury, a common cause of neurological dysfunction in humans and animals, impairs motor, sensory and autonomic functions and may result in permanent disability. Nandrolone decanoate (ND) is a steroid widely studied for its predominantly anabolic effect and low androgenic potential. Several researchers have described the positive interference of ND in neurological tissue, such as increased synthesis and release of neurotrophic substances, but to date no studies have evaluated the action of this steroid in acute spinal cord injury. The aim of this study was therefore to evaluate the effect of ND in rats subjected to acute spinal cord injury. Materials, Methods & Results: Thirty-two young adult Wistar rats (Rattus norvegicus), weighing between 240 and 260 g, were divided into three groups. The first group (GNAN) (n=13) was subjected to acute spinal cord injury and treated with ND; the control group (GCON) (n=13) was subjected to spinal cord injury without treatment; and the third group (GLAM) (n=6) underwent laminectomy without prior spinal cord injury, in order to control changes caused by the procedure. A 20 g metal device was released from a height of 25 cm to produce the spinal cord injury. After exposing the spinal canal, a 2-mm diameter metal rod was placed directly in contact with the spinal cord, and when the weight was released, the rod was struck, causing the spinal cord injury. An intramuscular injection of 2 mg/kg of ND was administered the immediate postoperative period. The animals were assessed to ascertain the recovery of their motor function on five occasions, namely at 24 h, 48 h, 72 h, 7 and 14 days after undergoing spinal cord injury. This assessment was performed using the Basso, Beattie and Bresnahan (BBB) model. The animals were euthanized 14 days post-op and fragments of the spinal cord and urinary bladder were collected for histological evaluation. Discussion: The animals subjected to spinal cord injury presented paraplegia, failing to score on the BBB scale in the first three assessments. Starting 7 days after surgery, the GNAN (0-13) and GCON (0-5) groups gradually began showing locomotor improvements, with scale variations. On day 14 after spinal cord injury, 22% of the animals in GNAN and 11% in GCON had failed to recover their locomotor function, scoring zero on the BBB scale. After spinal cord injury, all the animals showed urine retention. The urinary function returned on average on day 5 post surgery, with no significant difference between the groups. The locomotor assessment of the animals subjected to acute spinal cord injury revealed that the injury varied in intensity in GNAN and GCON, with signs of pelvic limb paraplegia and asymmetric non-ambulatory paraparesis. Time was a determining factor in the clinical evolution of the animals, with no evidence of the influence of ND. The histological findings revealed variations in the intensity of the injury, with a tendency for lower intensity in the cranial and epicentral segments of the lesion in the animals subjected to ND treatment, albeit without statistically significant evidence (P ≥ 0.05). The spinal cord assessments of the GLAM group indicated that the surgical procedure did not cause histological alterations, since the normal architecture of the neural tissue was preserved. The histopathological evaluations of the urinary bladder revealed an inflammatory response characterized by lymphohistiocytosis and neutrocytosis in the animals of GNAN and GCON, without interference of ND in the change (P ≥ 0.05). The method to elicit spinal cord injury reproduced functional, sensory and motor incapacity heterogeneously in rats. In the dose evaluated here, ND did not significantly influence the return of locomotor function and the intensity of spinal cord histopathological alterations.  

The COSMICS (Container Scanning by Muon-based Imaging using Cosmic rayS) Project; an introduction and preliminary results

Muon tomography represents a new and promising imaging technique, making use of ambient high-energy cosmic ray muons to generate images of three-dimensional volumes. The technique predominantly combines measurements of the Coulomb scattering of muons with sophisticated analysis methods to estimate the composition of objects and their distribution within an unknown volume. The COSMICS project will use this technique to design a passive tomographic system capable of detecting the presence of high atomic mass materials within a shipping container. The initial physics simulation studies are presented in this work. Consideration is also given to the ethical and legal concerns associated with the development of such a system and the impact on low- and middle-income countries (LMIC). Initial studies into potential risk scenarios relating to the trade of illicit and counterfeit goods have been undertaken, and a data-driven pre-screening concept is outlined

Identifying the need for specialized palliative care in adult cancer patients – development and validation of a screening procedure based on proxy assessment by physicians and filter questions

Background One challenge in caring for cancer patients with incurable disease is the adequate identification of those in need for specialized palliative care (SPC). The study’s aim was to validate an easy to use phenomenological screening tool. Methods The German tool is based on the National Comprehensive Cancer Network (NCCN) Palliative Care guidelines and contains ten items in five domains that focus e.g. on diagnosis, functional status, complications, comorbidities, and palliative care relevant problems such as symptom management, distress, and support of family and team members. Sum score ranges from 0 to 14 (no need to great need). Assessment to identify SPC needs was done in university hospital wards between 1 and 08/2017 by health care professionals on admission of the patient if the disease was incurable and expected prognosis < 12 months. The Integrated Palliative Outcome Scale (IPOS, staff version), an outcome assessment instrument for palliative care that consists of ten items, served as external criterion; in sub samples inter-rater/test-retest were performed. Results Data from 208 patients with incurable disease and life expectancy < 12 months (54.8% female; average age 63.5 years, range 21–96) were assessed using the tool. The tool has good convergent validity; the correlation between the sum scores of IPOS and our tool showed a significant and substantial effect. The sum score was independent of the patient’s age, gender and primary diagnosis. Patients who already were in contact with SPC had significantly higher screening scores than patients without. With a cut point of  ≥ 5, 80.8% of the screened patients were in need for SPC. Cronbach’s alpha was α = .600. Rater agreement (inter-rater, test-retest) varied between single items. Correlation coefficients showed significant substantial effects. Conclusions This is the first validation of a screening procedure in German language identifying SPC needs of adult patients with advanced cancer and the first using filter questions as a pre-screening. Proxy assessment of SPC needs by physicians in cancer care settings is feasible and the suggested tool presents a valid instrument to trigger a PC consultation. Trial registration The study was not registered

City of Hitchcock Comprehensive Plan 2020-2040

Hitchcock is a small town located in Galveston County (Figure 1.1), nestled up on the Texas Gulf Coast. It lies about 40 miles south-east of Houston. The boundaries of the city encloses an area of land of 60.46 sq. miles, an area of water of 31.64 sq. miles at an elevation just 16 feet above sea level. Hitchcock has more undeveloped land (~90% of total area) than the county combined. Its strategic location gives it a driving force of opportunities in the Houston-Galveston Region.The guiding principles for this planning process were Hitchcock’s vision statement and its corresponding goals, which were crafted by the task force. The goals focus on factors of growth and development including public participation, development considerations, transportation, community facilities, economic development, parks, and housing and social vulnerabilityTexas Target Communitie