No description available.

No description available.

Ingeniera Civil en Biotecnología / Este informe presenta la memoria de título realizada en colaboración con el Consorcio BAL Chile S.A.; cuyo objetivo es evaluar las condiciones de fermentación de carbohidratos de macroalga parda para optimizar su bioconversión a etanol, mediante el uso de cepas de microorganismos genéticamente modificados, y así, contribuir al desarrollo de la industria de biocombustibles de tercera generación en Chile. El desarrollo de este proyecto consistió, principalmente, en dos etapas: en la primera se realizaron fermentaciones aeróbicas con reactivos puros en distintas razones de alginato-manitol, de modo de simular la composición de carbohidratos presentes en las macroalgas pardas. Con estos cultivos se calculó y evaluó la velocidad de crecimiento y los rendimientos de biomasa y de producto, con la finalidad de determinar condiciones óptimas para fermentar. En una segunda etapa, realizaron fermentaciones micro-aeróbicas mediante un diseño experimental estadístico, para evaluar, principalmente, la producción de etanol. No se obtuvieron resultados favorables en esta condición, por lo que procedió a fermentar Macrocystis pyrifera en condiciones aeróbicas, con el objeto de verificar si los resultados con reactivos puros era reproducible al fermentar algas. Como resultado principal se obtuvo que la razón de alginato-manitol que reporta mejor rendimiento de etanol es 5:8 en condiciones aeróbicas. No obstante, el microorganismo puede crecer y fermentar favorablemente en distintas razones de carbohidratos, lo que elimina la variable de composición química de algas pardas. Las fermentaciones con Macrocystis pyrifera determinaron que no es necesario que la razón de carbohidratos se asemeje a la razón óptima determinada como óptima, sino que basta con la composición natural de la misma. Por lo tanto, esta macroalga nativa de Chile y su uso como materia prima para la producción de biocombustibles abre una oportunidad importante para la aumentar la participación de las Energías Renovables No Convencionales en la generación de energía del país, avanzando hacia la meta propuesta por el gobierno. Tras los análisis realizados, se estima que el rol principal de manitol es entregar poder reductor a la célula, el cual puede ser utilizado tanto en el crecimiento y metabolismo del microorganismo, como para la producción de etanol. Por otro lado, alginato es consumido para la formación de biomasa y de piruvato destinado a la producción de etanol. El estudio experimental desarrollado en esta memoria no consideró variables como la temperatura, pH o agitación. Por lo tanto se recomienda complementar este estudio añadiendo dichas variables, otorgando otras perspectivas valiosas al momento de decidir el escalamiento del proceso.

In this study, options for restoring fish populations in Hamilton City (37.47'S, 175.19'E) were explored. Habitat and fish populations in Hamilton urban streams were manipulated using a two-fold experimental design. Firstly, habitat was enhanced in ten urban streams with three continuous treatments in a 60-m reach at each site (20 m with 10 ponga logs, 20 m with 20 hollow clay pipes, and 20 m with no added structure). Secondly, juvenile farm-reared giant kokopu (Galaxias argenteus), were stocked into five of the enhanced stream sections. Giant kokopu are threatened and occur naturally in Hamilton urban streams in sparse populations. The abundance of wild fish was monitored before and after enhancement and fish release from November 2006 to November 2007. Stocked fish were monitored for eight months, from April to November 2007. Over this time electric fishing was conducted three times, trap nets (Gee minnow and fyke nets) were set monthly and spotlighting was conducted monthly at three release sites where water clarity allowed. Anticipated outcomes of this research were; to determine whether giant kokopu abundance in Hamilton urban streams is limited by recruitment or by habitat, and to assist with the development of methods to restore fish populations in Hamilton City urban streams. Logs used as enhancement structures in Hamilton urban streams provided more stable habitat for fish and created more suitable microhabitat than pipe structures. Pipes moved considerably during high flows, and their instability made them less effective at providing habitat. Within the study sites there appeared to be complex interactions with turbidity, stream width and depth, which complicated the effect of the habitat structures. The limited replication and variability among sites contributed to statistically insignificant results using analysis of variance. Retention and recapture rates of stocked juvenile giant kokopu were greatest at Site M11, where the stream was narrow, shallow, clear and had lower numbers and biomass of shortfin eels, compared to other survey sites. Marked and released giant kokopu were retained in the release reaches at four of the five sites, for a minimum of four months, and exhibited substantial growth. Daily growth of juvenile giant kokopu ranged from 0.19 to 0.33 mm day-1 and from 0.03 to 0.11 g day-1, exhibiting substantial growth over winter. Giant kokopu appeared to have a slight bias to the log section of enhanced habitat, but habitat selection appeared to be overwhelmingly controlled by initial habitat selection. The stocking of farm-reared fish into urban streams was largely successful, but the success of the habitat enhancement was variable and further work is required to determine better techniques for habitat enhancement in these urban environments. It is concluded that releasing farm-reared giant kokopu can be used to restore populations especially where recruitment limitations control fish abundance and diversity.

Individuals within a species often compete for resources in both space and time. In dominance hierarchies individuals with the greatest competitive ability will occupy prime locations during optimal periods to increase efficiency in gathering a resource. Subdominant individuals with low competitive abilities may be forced to reside in habitats of poor quality relative to dominant individuals. In this study I examined the long term patterns of giant kokopu distribution, movement, growth, habitat use, and social interaction between fish in relation to invertebrate drift (food supply). The habitat quality and abundance of food along a one km section of Alex�s Creek was monitored for a two year period. Though the physical structure of Alex�s Creek was relatively homogenous there were significant spatial differences in the density of drifting invertebrates sampled between riffles and pools over this long temporal period. In general, more drifting invertebrates were sampled in riffles of relatively long length and area. Within Alex�s Creek the distribution of giant kokopu, Galaxias argenteus, was determined by patchy distributions of food supply, specific physical factors of pools, and interactions between fish in dominance hierarchies. Over the 20 month study period, the most important biotic factor determining fish biomass was the total number of drifting invertebrates within pools while the most important abiotic factor determining fish abundances within pools was the pool size (surface area). The growth rate of individual fish correspondingly varied between fish residing within pools of different quality. Growth rates were higher for individual fish residing in pools with a relatively high density of drifting invertebrates. The differences in individual growth rates of giant kokopu may determine when fish leave a particular habitat patch (pool) and move to a new one. Fish that moved had lower growth rates (before moving) than fish that remained resident within home pools. Overall the movement of giant kokopu within Alex�s Creek was very restricted due to a relatively consistent distribution of food, however there were differences in the mobility of giant kokopu among different social ranks. The most dominant fish in pools were largely sedentary while fish ranked directly below fish 1 (i.e. fish 2 and 3 in social hierarchies) were relatively mobile. The ability of dominant fish to exclude subdominant fish from the most preferred feeding positions during optimal feeding times had consequences for overall giant kokopu activity. Under normal food supply conditions dominant fish were predominantly nocturnal and maintained large home ranges at night. Conversely subdominant fish occupied large home ranges by day, but were generally not observed at night. When the food supply was limited the utilization of pools was determined by social rank. Dominant fish from each pool increased daytime activity, home range size, aggressiveness, and the capture of food items offered by day while simultaneously reducing the spatial and temporal activity and habitat use of subdominant fish. These results indicate that behavioral changes in large dominant fish influence and reduce the amount of resources available to subdominant fish.

Giant reed (Arundo donax L.) is a candidate to provide feedstock for the Portland General Electric power plant in Boardman, Oregon. Giant reed is a fast perennial grass, producing 23-27 metric tons ha⁻¹ of biomass and has the ability to adapt to diverse environments making it a good candidate for biomass production. This study tested postemergence and preemergence herbicides for controlling weeds in giant reed during the establishment year in which giant reed plants are more sensitive to weed competition. The greenhouse study demonstrated that among the tested herbicides, bromoxynil plus MCPA at 0.841 kg ai ha⁻¹, nicosulforun at 0.035 kg ha⁻¹, and dimethenamid-p at 0.735 kg ha⁻¹ did not injure giant reed. In a field study, preemergence application of dimethenamid-p at 0.735 kg ha⁻¹ followed by a postemergence application of 2,4-D amine at 0.560 kg ha⁻¹ and a postemergence application of bromoxynil plus MCPA at 0.841 kg ha⁻¹ did not injure giant reed. The presence of weeds in a field does not always mean that crop yield will be reduced and there are some periods during the growing season when weeds will not cause considerable yield loss. Therefore, predicting a critical period of weed control (CPWC) that includes the best time for weed control in giant reed could improve weed management in the field. The length of the CPWC could be different depending on the level of acceptable yield loss (AYL). Our results are reported for AYL of 5 and 10%. The CPWC started at 290 accumulated growing degree days (GDD) and ended at 820 for a 5% AYL, while for a 10% AYL, it started at 333 GDD and ended at 727 GDD. Based on the results, there are some herbicides which could be selected for further study for weed control in the giant reed and the estimated CPWC which could be used to inform weed management practices in giant reed production. / Graduation date: 2013

The objective of this study was to develop near infrared reflectance spectroscopy (NIRS) calibration equations from bamboo and fecal samples to predict diet composition and the physiological status of giant pandas. Discrimination between branch, culm, and leaf parts of bamboo resulted in an Rsquare (R2) of 0.88. The calibration equation for discriminating between 4 species of bamboo had an R2 of 0.47. Calibration equations were created for all bamboo species combined to determine the ability of NIRS to predict the nutrient constituents of CP, NDF, ADF, DM, and OM. No R2 was lower than 0.96, with the exception of DM at 0.63, which was consistently difficult to accurately predict due to variation in factors relating to difference in location of lab work (humidity, shipping, methods, etc.). Giant panda diets vary between seasons from eating primarily leaf to eating almost only culm. When bamboo part samples were compared between March and October, all resulting R2s were above 0.80. The sensitivity analyses for leaf and culm samples within diet season produced inconclusive results, but sensitivity analyses for fecal samples yielded an ability to more greatly discriminate between months that were further apart. For giant panda physiological status calibrations, fecal samples were collected from the Memphis Zoo, Smithsonian's National Zoo, Zoo Atlanta, and San Diego Zoo from 2006 to 2007. One-hundred fecal spectra were used to develop discriminant equations with which to predict between adults and juveniles. The resulting calibration was 100% correct for both age classes. Predictions between 252 male and female fecal spectra were 89% correct for females and 90% correct for males. A small number of samples (N= 60) were used to create a discriminant equation to differentiate between pregnant and non pregnant females. The exercise resulted in an R2 of 0.68 and a prediction of 100% for both pregnant and not-pregnant. It has been determined through these studies that NIRS has the potential to determine nutrient composition of bamboo and giant panda fecals, but increased sampling and equation development is needed before these calibrations are applicable in a captive or wild giant panda setting.

Giant clams (Tridacnidae) are economic species which have been the main materials for ganbei. Due to a huge decline in population size, it was reported as an endangered species in CITES list. In this study, the effects of different preservative methods on the expression of DNA sequences in giant clams were examined and whether ganbai is made from giant clams were also determined. I collected samples from Kenting, Green Island, Orchid Island, Shaio-Liu-Chu and Penghu Islands. And, ganbei were bought from markets. Species identification was based on four DNA sequences (COI, 16S, 18S, 28S) and morphological characters. The distinction power of four preservative methods (-70 ¢J frozen, 70 % ethanol, dried and freeze dried) on clam samples was evaluated. DNA sequences of CO1 and 16S are the best fragments to distinguish samples at species level. Additionally, a cryptic species of Tridacna noae was found from Tridacna maxima. The 18S and 28S sequences have low variation among giant clam species which are more suitable for higher level of phylogeny. The DNA fragments with different preservative methods were mostly in good condition having extracted DNA size up to 10 Kb. The sequencing divergences of the four preservation were 0 - 0.020 within an individual and 0 - 0.070 among individuals. In conclusion, the four preservative methods are similar in sequence expression. Ganbei made from giant clams was not found in the market. Instead, commercial ganbei are made from scallops, mostly Patinopecten yessoensis and some Argopecten irradians.

No description available.

No description available.