Advection And Retention Of Larval Dungeness Crab Cancer Magister In Glacier Bay And Adjacent Areas

Thesis (Ph.D.) University of Alaska Fairbanks, 2007Spatial and temporal variations of larval abundance of Dungeness crabs were investigated as indications of larval advection and retention in southeastern Alaska. Larvae were collected in five transects: upper Chatham, Icy Strait, Cross Sound, and Icy Point, May to September 1997-2004 and Cape Edward in June 1998-1999. Larval densities were higher in inland water transect and lowest in offshore transects. In all transects, larval densities were highest in June. Zoeae I (ZI) were predominant with a small portion of later larval stages (ZII to ZV) in May. In May and June, late stages (ZIV and ZV) co-occurred with ZI. Later larval hatching in 1997 and 2002 and earlier larval hatching in 1998 may have been related to water temperature during the egg incubation period. Late larval stages that co-occurred with early larval stages can be transported from southern parts of their range where hatching occurs earlier. Mixing, loss, and distribution of larval Dungeness crabs were investigated inside and outside of Glacier Bay, southeastern Alaska, biweekly from late May to mid-September and monthly in Icy Strait from late May to late August in 2004. Larvae were collected from two different portions of the water column: above and below the thermocline and at four stations in Icy Strait. Larval loss was markedly high for ZI, ZIV, and ZV, and relatively low for ZII and ZIII. ZI occurred from late May to late July. Larval stages progressed seasonally from ZI to ZV and density decreased from ZI through ZV. The larval densities at the inner and outer bay stations and at the shallow and deep depths were similar. Co-occurrence of late and early larval stages and larvae with different rostrum lengths may be evidence of mixing of larvae incubated in different thermal regimes. The pattern of larval stages in Alaskan sites was markedly different from other parts of the species range: many of the early and intermediate stages occurred within inland waters, as opposed to increasing abundance of later stages with distance offshore

Larval development of the sidestriped shrimp (Pandalopsis dispar Rathbun) (Crustacea, Decapoda, Pandalidae) reared in the laboratory

Larval development of the sidestriped shrimp (Pandalopsis dispar) is described from larvae reared in the laboratory. The species has five zoeal stages and one postlarval stage. Complete larval morphological characteristics of the species are described and compared with those of related species of the genus. The number of setae on the margin of the telson in the first and second stages is variable: 11+12, 12+12, or 11+11. Of these, 11+12 pairs are most common. The present study confirms that what was termed the fifth stage in the original study done by Berkeley in 1930 was the sixth stage and that the fifth stage in the Berkeley’s study is comparable to the sixth stage that is described in the present study. The sixth stage has a segmented inner flagellum of the antennule and fully developed pleopods with setae. The ability to distinguish larval stages of P. dispar from larval stages of other plankton can be important for studies of the effect of climate change on marine communities in the Northeast Pacific and for marine resource management strategies

Development of CNN-Based Data Crawler to Support Learning Block Programming

Along with the importance of digital literacy, the need for SW(Software) education is steadily emerging. Programming education in public education targets a variety of learners from elementary school to high school. This study was conducted for the purpose of judging the proficiency of low school-age learners in programming education. To achieve the goal, a tool to collect data on the entire programming learning process was developed, and a machine learning model was implemented to judge the proficiency of learners based on the collected data. As a result of determining the proficiency of 20 learners, the model developed through this study showed an average accuracy of approximately 75%. Through the development of programming-related data collection tools and programming proficiency judging models for low school-age learners, this study is meaningful in that it presents basic data for providing learner-tailored feedback

Estimation of Fuel Economy Improvement in Gasoline Vehicle Using Cylinder Deactivation

Cylinder deactivation is a fuel economy improvement technology that has attracted particular attention recently. The currently produced cylinder deactivation engines utilize fixed-type cylinder deactivation in which only a fixed number of cylinders are deactivated. As fixed-type cylinder deactivation has some shortcomings, variable-type cylinder deactivation with no limit on the number of deactivated cylinders is under research. For variable-type cylinder deactivation, control is more complicated and production cost is higher than fixed-type cylinder deactivation. Therefore, it is necessary to select the cylinder deactivation control method considering both advantages and disadvantages of the two control methods. In this study, a fuel economy prediction simulation model was created using the measurement data of various vehicles with engine displacements of 1.0⁻5.0 L. The fuel economy improvement of fixed-type cylinder deactivation was compared with that of variable-type cylinder deactivation using the created simulation. As a result of examining the fuel economy improvement of the test vehicle in the FTP-75 driving cycle, the improvement was 2.2⁻10.0% for fixed-type cylinder deactivation and 2.2⁻12.8% for variable-type cylinder deactivation. Furthermore, the effect of the engine load on fuel economy improvement under cylinder deactivation and the effect of changes in engine control were examined via a simulation

Characterization of the complete mitochondrial genome of brown barracuda, Sphyraena pinguis (Perciformes: Sphyraenidae)

The entire mitochondrial genome sequence of Sphyraena pinguis collected from Korean water was determined by the Next Generation Sequencing (NGS) technology. Its total length was 16,620 bps in length, which possessed the canonical 37 genes in the eukaryotes. Unusual start codon was exclusively found in COX1(GTG), while incomplete stop codons (TA–/T—) were identified in ATP6, COX2, ND3, ND4, and Cyt b. A phylogenetic analysis with currently identified full mitogenomes in Perciformes, S. pinguis was most closely related to S. barracuda (76.87%) and S. jello (76.84%). This mitogenome sequence would explain the evolution of genus Sphyraena

Characterization of the complete mitochondrial genome of Odontobutis platycephala collected from Nakdong River, South Korea

The complete mitochondrial genome of Odontobutis platycephala collected from a native Korean river was determined by the bioinformatics assembly of the next-generation sequencing (NGS) reads. The circular mitogenome was 17,590 bp length which harbored canonical 13 protein-coding genes, 22 tRNAs, and 2 rRNAs, which was identical to those of family Odontobutidae. Twenty-eight genes were located on H strand, whereas remaining nine genes were on L strand. Except for COX1 gene (GTG), other 12 protein-coding genes were predicted typical start codons (ATG). Among the currently known mitogenome sequences, O. platycephala showed highest identity (96.98%) to Korean haplotype of O. platycephala (NC010199)