Parental care is a critical component of many breeding systems that enhances both parent and offspring fitness. It is widely recognized that parental care varies in quality and quantity in response to variation in offspring need, parental condition, and ecological context. One context that has been underexplored, however, is the difference in parental care between day and night, with many parental care studies focused on diurnal care. To fully understand the evolution of parental care, the costs and benefits and the negotiations between parents, both diurnal and nocturnal care must be accounted for. Here, we show that nocturnal parental care exists in the clownfish Amphiprion percula, with males and females actively caring for offspring at night throughout embryo development and during hatching in a laboratory setting. At night, as during the day, males are the dominant caregivers and both parents increase care as embryos mature. At night, in contrast to the day, females provide substantially more care. This increase in energy expended by parents on care may be a mechanism to increase dissolved oxygen in the water at night, improving embryo survival. We also document the existence of three new nocturnal parental care behaviors, not previously seen during the day: vigorous fanning, vigorous mouthing, and anemone biting. These behaviors are particularly frequent during hatching, and although they are not necessary for hatching to occur, they may serve to enhance the embryos’ successful transition from the benthos to the water column. This study contributes to our understanding of parental care, demonstrating the importance of considering nocturnal care if we are to gain a complete understanding of the evolution of parental care. / 2023-03-16T00:00:00Z

Effects of temperature (23, 26, 29°C) and salinity (0, 5, 10, 15, 20 ppt) on hatch success, growth, development, and survival of bigmouth sleeper Gobiomorus dormitor yolk sac larvae were determined. Hatch success was greater at lower temperatures (23°C) and salinities (0-10 ppt), while larval survival and growth were greater at 26°C and 0 ppt. Larvae reared at 29°C- 0 ppt developed rapidly but rarely survived 48-h post hatch, while larvae at 23°C- 0 ppt survived 120-h post hatch, developed slower. Salinity adversely affected larval survival and size at hatch, larvae reared at salinities 5 ppt or greater died within 12-h post hatch and larvae set at 0 ppt were significantly larger than larvae hatched at salinities 5 ppt or greater. The exogenously feeding larval stage was not achieved; however, this study provides valuable insight of the bigmouth sleeper early ontogeny and provides several techniques for improving future propagation attempts.

No description available.

In this project, the scan strategy of selective laser melting (SLM) for thin walled structures was investigated by changing laser parameters and tool path. Producing thin walled structures is difficult due to defects such as warpage and porosity. A layer on the SLM 125 consists of hatch volume, fill contours, and borders, however, for thin walls, hatch volume can become unavailable, resulting in a solely border/fill contour laser tool path. Three central composite designs (CCD) were created to optimize the laser parameters of borders to minimize leakage rate and porosity. The two factors changed were border laser power and scanning speed. The center points of the CCDs were 0.24 J/mm, 0.20 J/mm, and 0.16 J/mm, respectively. This border linear energy density value was calculated by (border laser power / border scanning speed). A machined aluminum fixture was designed and assembled with pneumatics to perform a pressure drop leakage test. Additionally, micrographs of 500μm and 200μm wall thicknesses were analyzed to study between and within layers as well as melt pool dimensions. In the 200μm thick samples, there was delamination and insufficient overlap in border only prints. For border only prints, a lower border linear energy density is recommended, similar to Cal Poly’s hatch volume optimized parameters of 0.15 J/mm.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22074号 / 農博第2366号 / 新制||農||1072(附属図書館) / 学位論文||R1||N5228(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 近藤 直, 准教授 小川 雄一, 教授 飯田 訓久 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Seven experimental trials were conducted to develop and use novel techniques to examine the relationships between pre- and post-hatch physiological parameters in the progeny of young broiler breeders. Trials 1, 2 and 3 together examined the safer and effective use of transponders to determine embryonated egg air cell temperature (Temb) as an estimation of broiler embryo temperature during incubation, and to subsequently calculate eggshell water vapor conductance (GH2O), specific GH2O (gH2O) and GH2O constants (KH2O) in modern broiler strains. Trials 4 and 5 together examined the relationships of early, middle and late post-hatch growth quality parameters and tissue nutritional profiles of broilers with the corresponding Temb, GH2O, gH2O and KH2O. Furthermore, Trials 6 and 7 together examined the changes in nutritional profiles and histological structures of the broiler embryonic pipping muscle between 15 and 19 days of incubation. Based on the results from Trials 1, 2 and 3, it was concluded that transponders may be effectively implanted in the embryonated egg air cells with minimal invasion to the broiler embryo to efficiently determine Temb, and to subsequently calculate GH2O, gH2O and KH2O of modern broiler strain eggs during incubation. The results from Trials 4 and 5 also suggested that within physiological limits, an increased gH2O results in increased embryo metabolism, which subsequently increases growth and yolk sac absorption in the corresponding broiler chicks through 3 days post-hatch. Moreover, it was also observed that a higher gH2O was negatively associated with chick hydration status on day 28 post-hatch; although such effects were not observed through day 48 of the post-hatch grow out period. It was concluded that the effects of gH2O on post-hatch broiler physiology may be more pronounced during early and middle post-hatch periods and may subside as the chick reaches marketing age. Furthermore, the results from Trials 6 and 7 indicated that changes in the nutritional profiles of the pipping muscle occur in accordance with corresponding changes in liver metabolism, and that these together with associated morphological changes in the pipping muscle, as observed through histological techniques may be critical for the broiler embryo’s preparation for hatch.

In this study, the effects of individual and combinatorial electrolyte solution comprised of carbohydrate, salt, and a stimulant injected into broiler hatching eggs on subsequent late term embryogenesis and post hatch performance up to D 10 were evaluated in separate trials. The effects of solution concentration and volume on embryo body weight and yolk reserves were likewise considered, and limited posthatch growth, body weight, and yolk sac effects of a compound electrolyte solution were evaluated. The individual and combinatorial effects of injected solutions were examined in an effort to yield the maximum physiological growth effects on embryogenesis from the metabolic pathways in which these compounds are involved. Limited effects on embryo and post hatch mortality were found. However, both post hatch yolk reserves and liver weights were affected by in ovo injection. These effects could be key in increasing bird weight by processing day.

In today’s society, the majority of our population lacks knowledge about agriculture and its importance. Therefore, there is a demand for agricultural programs to increase a general knowledge of agriculture. This study aimed to develop, pilot test, and evaluate the Hybrid-Online Hatch-out Program. Due to limited resources with the current Hands-on Hatch-out program, this Hybrid-Online Hatch-out Program could reach a larger population of youth and aid in educating more youth about poultry (one of the largest sectors of agriculture). The RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, and Maintenance) was utilized to guide the evaluation process. The program was pilot-tested in two elementary schools with 14 teachers and 172 students in Pre-K through first grade. Overall, teachers were satisfied with the program, indicated that it was feasible to implement, and planned to repeat the program in the future. Additionally, students’ pre- to post-program increase in poultry knowledge was statistically significant.

No description available.

Syftet med detta arbete har varit att genomföra en konceptstudie av en teknisk lösning för öppning och stängning av en testcells avgastorn. Detta som en del av det projekt som omfattar ombyggnation av testcellens utlopp. Frågeställningen som studien skall svara på är om det lönar sig att ha en lucka på tornet med hänsyn till det skydd den kan erbjuda och den ekonomiska kostnaden. De mål som sattes upp var att framställa en lämplig kravspecifikation, framställa minst ett fullständigt koncept, framställa en jämförelsematris, föreslå en lösning att ta till förstudie och ge förslag på fortsatt arbete till förstudien. Konceptmetodiken har hämtats från den metod som SAAB använder sig av i utvecklingsprojekt men har modifierats aningen av författarna. Intressenterna till testcellen står i fokus för att framställa en kravspecifikation utifrån deras behov. Intervjuer genomfördes med intressenter och sakkunniga för att erhålla uttalanden. Dessa uttalanden skulle sammanställas och användas som en del av underlaget till en rekommendation. Ett iterativt arbetssätt användes i konceptgenereringen där koncept framställdes och dess funktion utvärderades. De koncept som togs vidare utvärderades mot de identifierade behoven och mot varandra i ett antal jämförelsematriser. Den ekonomiska prognosen byggdes på uppskattade värden och historisk data för kostnader. En övervägande del av intressenterna och sakkunniga som intervjuats har varit positivt inställda till att ha en lucka på avgastornet. Framförallt för det utökade skydd det bidrar med och den potentiellt förlängda livslängden. Kravspecifikationen utformades på ett sådant sätt att det skulle fungera som ett styrdokument för studien, men också innehålla tillräckligt med information för att ge en översiktlig bild av problemet vid överlämning. Tre slutgiltiga koncept presenterades varav ett rekommenderas att ta vidare till förstudie, med motiveringen att den uppfyllde kravet på funktionalitet bäst. Det var även en känd lösning så livscykelanalysen hade en högre grad av säkerhet. / The purpose of this work has been to carry out a concept study of a technical solution for opening and closing a test cell's exhaust tower. This is a part of the project that includes rebuilding the test cell outlet. The question that the study will answer is whether it pays to have a hatch on the tower with regard to the protection it can offer and the financial cost. The goals that were set were to produce an appropriate requirements specification, produce at least one complete concept, produce a comparison matrix, propose a solution to use for a prestudy and provide suggestions for further work for the prestudy. The concept methodology has been taken from the method that SAAB uses in development projects but has been slightly modified by the authors. The stakeholders in the test cell are the prime focus as the requirements specification is based on their needs. Interviews were conducted with stakeholders and experts to obtain statements. These statements would be compiled and used as part of the basis for are commendation. An iterative approach was used in the concept generation where concepts were produced and its function was evaluated. Suitable concepts were evaluated against the identified needs and against each other in a number of comparison matrices. The economic forecast was based on estimated values and historical data for costs. A predominant part of the interviewed stakeholders and experts were positive about having a hatch on the exhaust tower. Mainly because of the increased protection it would contribute and the potential extension of the towers lifespan. The requirements specification was designed to function as a control document but also contain enough information to provide an overview of the problem for the handover to the prestudy. Three final concepts were presented, one of which is recommended for further study, with the justification that it best met the requirement for functionality. It was also a known solution so the life cycle analysis had a higher degree of certainty.