Growth and Feeding Studies on the Algal Feeding Stage of a Pfiesteria-like Dinoflagellate

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 105 mL-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were highest with a cryptophyte, Cryptomonas, as food, but growth was also demonstrated utilizing both diatoms and chlorophytes. Cryptoperidiniopsis sp. is similar to Pfiesteria in that it feeds myzocytotically with a peduncle, is similar in size and shape, has a complex life cycle, and is distinguished only by plates hidden under membranes

Growth and Feeding Studies on the Algal Feeding Stage of a Pfiesteria-like Dinoflagellate

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 105 mL-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were highest with a cryptophyte, Cryptomonas, as food, but growth was also demonstrated utilizing both diatoms and chlorophytes. Cryptoperidiniopsis sp. is similar to Pfiesteria in that it feeds myzocytotically with a peduncle, is similar in size and shape, has a complex life cycle, and is distinguished only by plates hidden under membranes

The Standardized Fish Bioassay Procedure for Detecting and Culturing Actively Toxic Pfiesteria, Used by Two Reference Laboratories for Atlantic and Gulf Coast States

In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the gold standard that must be used to detect toxic strains of Pfiesteria slop. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in research with toxic Pfiesteria. The steps involve isolating toxic strains of Pfiesteria (or other potentially, as-yet-undetected, toxic Pfiesteria or Pfiesteria-like species) from fish-killing bioassays with natural samples; growing the clones with axenic algal prey; and retesting the isolates in a second set of fish bioassays. The specific environmental conditions used (e.g., temperature, salinity, light, other factors) must remain flexible, given the wide range of conditions from which natural estuarine samples are derived. We present a comparison of information provided for fish culture conditions, reported in international science journals in which such research is routinely published, and we provide information from more than 2,000 fish bioassays with toxic Pfiesteria, along with recommendations for suitable ranges and frequency of monitoring of environmental variables. We present data demonstrating that algal assays, unlike these standardized fish bioassays, should not be used to detect toxic strains of Pfiesteria spp. Finally, we recommend how quality control/assurance can be most rapidly advanced among laboratories engaged in studies that require research-quality isolates of toxic Pfiesteria spp

Integrating gamification into a system to improve diet compliance for elderly users

Nowadays, gamification is applied in many areas, including healthy lifestyle promotion. In earlier work, a system has been proposed to stimulate diet compliance and adherence of participants of a trial within the PROMISS-project. In this paper, we describe the design of a gamified version of this system. The goal of the gamification is to further stimulate diet compliance and adherence to the system, but also to increase the knowledge about the diet and make the use of the system more fun. To do so, we implemented gamification elements (profile page, achievements, mini-games, and a reward garden) to address multiple behaviour change techniques. Based on a small evaluation, the system has been improved so that it can be used by participants of the PROMISS trial. At the end of this paper, future improvements are suggested in the future work sectio

Hydrogen atom in a spherical well: linear approximation

We discuss the boundary effects on a quantum system by examining the problem of a hydrogen atom in a spherical well. By using an approximation method which is linear in energy we calculate the boundary corrections to the ground-state energy and wave function. We obtain the asymptotic dependence of the ground-state energy on the radius of the well.Comment: Revised version to appear in European Journal of Physic

Gamification through leaderboards : an empirical study in engineering education

Universities are looking for solutions to engage more students in STEM domains and enhance their learning performance (LP). In this context, gamification is put forward as a solution to achieve this aim. The present study examined the effect of gamification – building on leaderboards ‐ on LP. Furthermore, mediating variables, such as intrinsic motivation, self‐efficacy, engagement, and background variables, such as sex, previous gaming experience, and undergraduate major, were considered. A pretest‐posttest quasi‐experimental design with an experimental and a control condition was set up (n = 89) in an Introductory Computer Programming course. We observed a significant improvement in the LP of students in the gamified condition. However, no interaction effect was detected, due to mediating and background variables. The high learning gain is a favorable indicator that gamification might be a promising approach to promote STEM programs

Computers in Secondary Schools: Educational Games

This entry introduces educational games in secondary schools. Educational games include three main types of educational activities with a playful learning intention supported by digital technologies: educational serious games, educational gamification, and learning through game creation. Educational serious games are digital games that support learning objectives. Gamification is defined as the use of "game design elements and game thinking in a non-gaming context" (Deterding et al. 2011, p. 13). Educational gamification is not developed through a digital game but includes game elements for supporting the learning objectives. Learning through game creation is focused on the process of designing and creating a prototype of a game to support a learning process related to the game creation process or the knowledge mobilized through the game creation process. Four modalities of educational games in secondary education are introduced in this entry to describe educational games in secondary education: educational purpose of entertainment games, serious games, gamification, and game design

Multipotent adult progenitor cells sustain function of ischemic limbs in mice

Despite progress in cardiovascular research, a cure for peripheral vascular disease has not been found. We compared the vascularization and tissue regeneration potential of murine and human undifferentiated multipotent adult progenitor cells (mMAPC-U and hMAPC-U), murine MAPC-derived vascular progenitors (mMAPC-VP), and unselected murine BM cells (mBMCs) in mice with moderate limb ischemia, reminiscent of intermittent claudication in human patients. mMAPC-U durably restored blood flow and muscle function and stimulated muscle regeneration, by direct and trophic contribution to vascular and skeletal muscle growth. This was in contrast to mBMCs and mMAPC-VP, which did not affect muscle regeneration and provided only limited and transient improvement. Moreover, mBMCs participated in a sustained inflammatory response in the lower limb, associated with progressive deterioration in muscle function. Importantly, mMAPC-U and hMAPC-U also remedied vascular and muscular deficiency in severe limb ischemia, representative of critical limb ischemia in humans. Thus, unlike BMCs or vascular-committed progenitors, undifferentiated multipotent adult progenitor cells offer the potential to durably repair ischemic damage in peripheral vascular disease patients

Protective Intestinal Effects of Pituitary Adenylate Cyclase Activating Polypeptide

Pituitary adenylate cyclase activating polypeptide (PACAP) is an endogenous neuropeptide widely distributed throughout the body, including the gastrointestinal tract. Several effects have been described in human and animal intestines. Among others, PACAP infl uences secretion of intestinal glands, blood fl ow, and smooth muscle contraction. PACAP is a well-known cytoprotective peptide with strong anti-apoptotic, anti-infl ammatory, and antioxidant effects. The present review gives an overview of the intestinal protective actions of this neuropeptide. Exogenous PACAP treatment was protective in a rat model of small bowel autotransplantation. Radioimmunoassay (RIA) analysis of the intestinal tissue showed that endogenous PACAP levels gradually decreased with longer-lasting ischemic periods, prevented by PACAP addition. PACAP counteracted deleterious effects of ischemia on oxidative stress markers and cytokines. Another series of experiments investigated the role of endogenous PACAP in intestines in PACAP knockout (KO) mice. Warm ischemia–reperfusion injury and cold preservation models showed that the lack of PACAP caused a higher vulnerability against ischemic periods. Changes were more severe in PACAP KO mice at all examined time points. This fi nding was supported by increased levels of oxidative stress markers and decreased expression of antioxidant molecules. PACAP was proven to be protective not only in ischemic but also in infl ammatory bowel diseases. A recent study showed that PACAP treatment prolonged survival of Toxoplasma gondii infected mice suffering from acute ileitis and was able to reduce the ileal expression of proinfl ammatory cytokines. We completed the present review with recent clinical results obtained in patients suffering from infl ammatory bowel diseases. It was found that PACAP levels were altered depending on the activity, type of the disease, and antibiotic therapy, suggesting its probable role in infl ammatory events of the intestine

Appropriateness of antibiotic treatment in intravenous drug users, a retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Infectious disease is often the reason for intravenous drug users being seen in a clinical setting. The objective of this study was to evaluate the appropriateness of treatment and outcomes for this patient population in a hospital setting.</p> <p>Methods</p> <p>Retrospective study of all intravenous drug users hospitalized for treatment of infectious diseases and seen by infectious diseases specialists 1/2001–12/2006 at a university hospital. Treatment was administered according to guidelines when possible or to alternative treatment program in case of patients for whom adherence to standard protocols was not possible. Outcomes were defined with respect to appropriateness of treatment, hospital readmission, relapse and mortality rates. For statistical analysis adjustment for multiple hospitalizations of individual patients was made by using a generalized estimating equation.</p> <p>Results</p> <p>The total number of hospitalizations for infectious diseases was 344 among 216 intravenous drug users. Skin and soft tissue infections (n = 129, 37.5% of hospitalizations), pneumonia (n = 75, 21.8%) and endocarditis (n = 54, 15.7%) were most prevalent. Multiple infections were present in 25%. Treatment was according to standard guidelines for 78.5%, according to an alternative recommended program for 11.3%, and not according to guidelines or by the infectious diseases specialist advice for 10.2% of hospitalizations. Psychiatric disorders had a significant negative impact on compliance (compliance problems in 19.8% of hospitalizations) in multiple logistic regression analysis (OR = 2.4, CI 1.1–5.1, p = 0.03). The overall readmission rate and relapse rate within 30 days was 13.7% and 3.8%, respectively. Both non-compliant patient behavior (OR = 3.7, CI 1.3–10.8, p = 0.02) and non-adherence to treatment guidelines (OR = 3.3, CI 1.1–9.7, p = 0.03) were associated with a significant increase in the relapse rate in univariate analysis. In 590 person-years of follow-up, 24.6% of the patients died: 6.4% died during hospitalization (1.2% infection-related) and 13.6% of patients died after discharge.</p> <p>Conclusion</p> <p>Appropriate antibiotic therapy according to standard guidelines in hospitalized intravenous drug users is generally practicable and successful. In a minority alternative treatments may be indicated, although associated with a higher risk of relapse.</p