Hatching Strategies in Monogenean (Platyhelminth) Parasites that Facilitate Host Infection

In parasites, environmental cues may influence hatching of eggs and enhance the success of infections. The two major endoparasitic groups of parasitic platyhelminths, cestodes (tapeworms) and digeneans (flukes), typically have high fecundity, infect more than one host species, and transmit trophically. Monogeneans are parasitic flatworms that are among the most host specific of all parasites. Most are ectoparasites with relatively low fecundity and direct life cycles tied to water. They infect a single host species, usually a fish, although some are endoparasites of amphibians and aquatic chelonian reptiles. Monogenean eggs have strong shells and mostly release ciliated larvae, which, against all odds, must find, identify, and infect a suitable specific host. Some monogeneans increase their chances of finding a host by greatly extending the hatching period (possible bet-hedging). Others respond to cues for hatching such as shadows, chemicals, mechanical disturbance, and osmotic changes, most of which may be generated by the host. Hatching may be rhythmical, larvae emerging at times when the host is more vulnerable to invasion, and this may be combined with responses to other environmental cues. Different monogenean species that infect the same host species may adopt different strategies of hatching, indicating that tactics may be more complex than first thought. Control of egg assembly and egg-laying, possibly by host hormones, has permitted colonization of frogs and toads by polystomatid monogeneans. Some monogeneans further improve the chances of infection by attaching eggs to the host or by retaining eggs on, or in, the body of the parasite. The latter adaptation has led ultimately to viviparity in gyrodactylid monogeneans

UTILIZING VROOM\u27S EXPECTANCY THEORY AS A PREDICTOR OF STUDENT ACADEMIC SUCCESS ON THE ILLINOIS NURSE ASSISTANT COMPETENCY EXAMINATION

AN ABSTRACT OF THE DISSERTATION OF Kelli D. Whittington, for the Doctor of Philosophy degree in Work Force Education, presented on June 23, 2014, at Southern Illinois University Carbondale. TITLE: UTILIZING THE EXPECTANCY THEORY AS A PREDICTOR OF STUDENT ACADEMIC SUCCESS ON THE ILLINOIS NURSE ASSISTANT COMPETENCY EXAMINATION MAJOR PROFESSOR: Dr. C. Keith Waugh This study researches the relationship between motivation and academic success as measured by the Valence, Instrumentality, Expectancy Scale. Utilizing Vroom\u27s Expectancy Theory as the framework for study, the research assessed the responses of 375 nurse assistant students in the state of Illinois to evaluate the self-report of the constructs of Vroom\u27s Expectancy Theory in relation to their performance on the Illinois Nurse Assistant Training Competency Examination

The impact of feed cost on U.S. poultry production: implications for the impact of increased ethanol production

Crop Production/Industries, Livestock Production/Industries,

Water resources management in the Nile basin: The economic value of cooperation

Water Policy73227-252WPAO

A new species of Dermopristis Kearn, Whittington & Evans-Gowing, 2010 (Monogenea: Microbothriidae), with observations on associations between the gut diverticula and reproductive system and on the presence of denticles in the nasal fossae of the host Glaucostegus typus (Bennett) (Elasmobranchii: Rhinobatidae)

Dermopristis cairae n. sp. (Microbothriidae) is described from the skin and possibly from the nasal fossae of the giant shovelnosed ray Glaucostegus typus (Bennett). The new species is distinguished from D. paradoxus Kearn, Whittington & Evans-Gowing, 2010 by its larger size, body shape, lack of transverse ridges on the ventral surface and absence of a seminal receptacle. Extensive short gut branches lie dorsal to the testes and adjacent to the coiled region of the vas deferens and the oo¨type, possibly reflecting high metabolic demand in these areas. Denticles are present in the lining of the nasal fossae of G. typus, providing a firm substrate for the cement-based attachment of a microbothriid. However, confirmation that D. cairae inhabits the nasal fossae of G. typus is required

Accounting for Indirect Costs in Public Health Cost Analyses

Background. There is a gap in research regarding the resources needed to deliver public health activities, which inhibits informed decision making around investments in public health and the allocation of funds among activities. When conducting cost analyses in public health, it is important to include costs from all cost components, including personnel, non-personnel, and indirect costs. However, defining, identifying, and measuring indirect costs is challenging and can impede studies of this type. Purpose. The purpose of this pilot study is to create a catalog of the methodologies public health researchers have used to account for indirect costs. Methods. We surveyed the final products submitted by the eleven practice-based research networks who received funding from the Robert Wood Johnson Foundation to explore the delivery and cost of public health activities for their indirect cost inclusion method. The primary investigators were contacted to verify their methodology. Ten of the 11 networks (91%) could be reached. Results. Four of the networks used a pre-negotiated rate the health department had with the state agency. Three of the networks used a data collection instrument that had public health administrative staff estimate these costs. Three of the networks did not include indirect costs in their analyses. Implications. Although challenging, it is important to include indirect costs in public health cost analyses as they are a real cost to public health departments and research findings without these costs have limited applicability. This review can assist researchers by reviewing approaches previously used by public health researchers

A role for fast rhythmic bursting neurons in cortical gamma oscillations in vitro

Basic cellular and network mechanisms underlying gamma frequency oscillations (30–80 Hz) have been well characterized in the hippocampus and associated structures. In these regions, gamma rhythms are seen as an emergent property of networks of principal cells and fast-spiking interneurons. In contrast, in the neocortex a number of elegant studies have shown that specific types of principal neuron exist that are capable of generating powerful gamma frequency outputs on the basis of their intrinsic conductances alone. These fast rhythmic bursting (FRB) neurons (sometimes referred to as "chattering" cells) are activated by sensory stimuli and generate multiple action potentials per gamma period. Here, we demonstrate that FRB neurons may function by providing a large-scale input to an axon plexus consisting of gap-junctionally connected axons from both FRB neurons and their anatomically similar counterparts regular spiking neurons. The resulting network gamma oscillation shares all of the properties of gamma oscillations generated in the hippocampus but with the additional critical dependence on multiple spiking in FRB cells

Preweaning and Postweaning Performance of Crossbred Calves--0, 1 or 2 Ralgro Implants

The preweaning performance of 221 steer and heifer calves given differing numbers of Ralgro implants was evaluated. The steer and heifer calves given one implant had an additional 23 and 33 lb weaning weight compared to those receiving no implant. No additional response was shown by steer calves receiving a second implant 100 days after the first was given. Average daily gains during the 105-day growing period were not significantly faster than those receiving two implants during the 103-day finishing phase. This work supports other studies indicating that implanting calves at weaning time is an economical management practice. The work further indicates to feeders that calfhood implants have little or no effect on subsequent performance in the feedlot

Effect of Length of Feeding Period on Performance of British and Exotic Crossbred Yearling Heifers

Seventy-two heifers were fed for 47, 61 and 75 days to determine the optimum feeding period for exotic cross and black baldy heifers. Average daily gains and feed conversions of the heifers were similar among treatments. Carcass weight, quality grade and yield grade increased with time on feed. Fat thickness, quality grade and yield grade increased faster for the black baldy heifers. Cost per pound of gain was similar for all treatments. The optimum weight at which to slaughter the black baldy yearling heifers appeared to be between 1000 and 1050 lb., both from a quality and economic view point. The optimum weight for slaughtering the exotic cross heifers was apparently not reached, as the last slaughter group was still gaining rapidly and efficiently with little increase in condition. The limited research conducted in this study indicates that a producer with mixed lots of cattle needs to be aware of the weight at which different types of cattle reach optimum condition. The feeder has greater flexibility in marketing the larger framed exotic cross type cattle as compared to the relatively smaller framed English breeds

Feeding Value of Pro-Sil Treated High-Moisture Ground Ear Corn with Two Groups of Crossbred Heifers

Pro-Sil, an ammonia-molasses-mineral suspension, has been shown to be a highly effective commercial additive for corn silage in studies at SDSU and other midwest universities. When added to corn silage at the time of ensiling, this product stimulates beneficial fermentation and increases the crude protein content of the silage, thereby reducing or eliminating the need for protein supplementation at the time of feeding. While Pro-Sil has been thoroughly tested with whole plant corn silage, no research has been conducted with ensiled high-moisture ear corn (HMEC). Since the crude protein content of HMEC is low compared to the needs of feedlot cattle, research is needed to evaluate economical methods of boosting the level of this critical nutrient. Thus, the major objective of this initial study was to compare the feedlot performance of cattle fed Pro-Sil treated HMEC or regular HMEC mixed with either a control or a urea-based protein supplement at the time of feeding. Both types of HMEC were ensiled in a plastic Silopress bag to examine the effectiveness of this storage method with HMEC. The relative performance of exotic and British crossbred yearling heifers was also studied in this trial