Feeding ecology of juvenile sockeye salmon in Afognak Lake, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2016Much attention has been given to juvenile Sockeye Salmon (Oncorhynchus nerka) ecology with particular focus on pelagic food webs in deep nursery lakes. In contrast, this study took place at Afognak Lake, Alaska, to better understand juvenile Sockeye Salmon foraging ecology, potential consumer interactions, and metabolic opportunities and constraints in a shallow nursery lake. I collected fish every two weeks from Afognak Lake from May through August, 2013. I described ontogenetic and temporal variation in the diets of juvenile Sockeye Salmon and a potential competitor, adult Threespine Stickleback (Gasterosteus aculeatus). Notably, this study revealed that adult aquatic insects are an important prey item for lake rearing juveniles. Threespine Stickleback diets showed some overlap with diets of juvenile Sockeye Salmon; however, significant differences in diet composition suggest that Sockeye Salmon and Threespine Stickleback partition prey and habitat resources. I then used my field-derived temperature, demographic, and diet data as inputs to a bioenergetics model to estimate summer consumption rate and growth efficiency of juvenile Sockeye Salmon from Afognak Lake across a range of foraging scenarios. Consumption rate was greater and mean growth efficiency was lower for all littoral-use scenarios relative to pelagic-use scenarios. Further, daily consumption was lowest and mean growth efficiency was highest for model scenarios in which insects were a dominant component of the diet relative to scenarios in which zooplankton were the dominant prey. My findings highlight the importance of benthic-pelagic coupling in Sockeye Salmon nursery lakes and the potential for juveniles to navigate trade-offs between energy acquisition and thermal conditions across lake habitats.General Introduction -- Chapter 1: Feeding ecology of juvenile Sockeye Salmon and a potential competitor, Threespine Stickleback, in a shallow Alaskan lake -- Chapter 2: Bioenergetic tradeoffs among foraging environments for lake rearing juvenile sockeye salmon -- General Conclusions -- Benthic and pelagic production pathways in Afognak Lake -- Potential for competition between Threespine Stickleback and Sockeye Salmon -- Heterogeneity in lake foraging habitat for Sockeye Salmon

Formation of radiation defects in Silicate and borosilicate glasses caused by UV lamp and excimer laser Irradiation

Solarization of colourless and coloured glasses of the type AR®, BK7® and DURAN® with high transmission in the UV-B region (280 to 320 nm) was investigated for their use as Container glasses in the solar disinfection of drinking water. The samples were coloured by doping with NiO or CoO. The influence of the Fe³⁺/Fe²⁺ content and of the reducing component Sn²⁺ was investigated on both the initial transmission of the glasses and the solarizadon. The samples were irradiated with a 1 kW Xe lamp and a XeCl excimer laser. The solarization depends on the glass matrix and is enhanced by colouring ions. The influence of Fe³⁺/Fe²⁺ and Sn²⁺ on the defect generation is different for glasses coloured with NiO than for those coloured with CoO. For the samples investigated it was possible to simulate the loss of transmission in the UV-B region due to long-time irradiation with sunlight by a laser experiment

Self-care appraisal in nursing assistant students: Adaptation, validation and psychometric properties of the Spanish ASAS

The core implication of nursing professionals' labor is promoting self-care and foster well-being among healthcare service users. The beginning of the healing process starts with the provider, and self-care habits are needed to positively impact on patients' care outcomes at different spheres. Overall, current literature supports the idea that nurses' personal self-care should be a necessary skill to be expected in their professional role. In this regard, the Appraisal of Self-care Agency Scale (ASAS) is a worldwide known instrument aimed at assessing the ability to engage in self-care. However, it has never been tested in the Spanish context before, and much less in nursing practitioners or apprentices. The aim of this study was to translate, adapt and validate the ASAS for Spanish nursing apprentices, assessing its dimensionality, psychometric properties and convergent validity by means of the Sense of Coherence (SOC-13) questionnaire. Methods: Data were collected from a random sample of 921 Certificated Nursing Assistant (CNA) Spanish students and was analyzed trough confirmatory factor analyses via structural equation models. The core ASAS construct and its subscales were correlated with the SOC-13 scores. Results: Fair psychometric properties for the questionnaire were set. Also, SEM models endorse the validity and reliability of the four-factor dimensionality of the Spanish adaptation of the ASAS, whose associations to SOC scores were coherent and significant. Conclusion: This study allowed to establish that the Spanish version of the ASAS might be a useful tool for addressing self-care-related issues among nursing apprentices, a key population for promoting both their own and patients' health and welfare through healthy and care-related behaviors

The Pareto Cover Problem

We introduce the problem of finding a set B of k points in [0,1]? such that the expected cost of the cheapest point in B that dominates a random point from [0,1]? is minimized. We study the case where the coordinates of the random points are independently distributed and the cost function is linear. This problem arises naturally in various application areas where customers\u27 requests are satisfied based on predefined products, each corresponding to a subset of features. We show that the problem is NP-hard already for k = 2 when each coordinate is drawn from {0,1}, and obtain an FPTAS for general fixed k under mild assumptions on the distributions

Evolution of Adaptive Behaviour in Robots by Means of Darwinian Selection

ii.34., humans have been intrigued by the origin and mechanisms underlying complexity in nature. Darwin suggested that adaptation and complexity could evolve by natural selection acting successively on numerous small, heritable modifications. But is this enough? Here, we describe selected studies of experimental evolution with robots to illustrate how the process of natural selection can lead to the evolution of complex traits such as adaptive behaviours. Just a few hundred generations of selection are sufficient to allow robots to evolve collision-free movement, homing, sophisticate

Konflik peran ganda dan stres kerja karyawati yang bekerja di Bank XXX Kanca Dharmasraya

Bekerja sebagai karyawan Bank merupakan salah satu pekerjaan yang cukup banyak diminati masyarakat. Hal tersebut dikarenakan selain bergengsi, gaji yang didapatkan juga relatif besar dan berbanding lurus dengan tuntutan kerja yang diemban karyawan, yang kemudian berpotensi besar pula untuk mengalami stres dalam bekerja. Khususnya bagi karyawati, mengingat secara empirik salah satu hasil penelitian sebelumnya menjelaskan bahwa karyawan wanita yang bekerja di Bank memiliki tingkat stres yang lebih tinggi dibandingkan dengan karyawan pria. Oleh karena itu, untuk melakukan antisipasi tingginya tingkat stres yang dialami oleh karyawati yang bekerja di perbankan, maka penting untuk menguji hubungan antara konflik peran ganda dengan stres kerja karyawati yang bekerja di Bank, mengingat penelitian ini masih sangat jarang ditemui dalam konteks perbankan. Dengan demikian penelitian ini bertujuan untuk melihat hubungan antara konflik peran ganda dengan stres kerja karyawati yang bekerja di Bank XXX Kanca Dharmasraya. Pendekatan pada penelitian ini menggunakan pendekatan kuantitatif dengan metode korelasi. Teknik pengambilan sampel yang digunakan dalam penelitian ini adalah purposive sampling dengan jumlah sampel penelitian sebanyak 31 orang. Alat ukur yang digunakan dalam penelitian ini adalah skala konflik peran ganda dan skala stres kerja. Hasil analisis data menunjukkan besarnya koefisien korelasi sebesar r=0,609 dengan taraf signifikan p=0,000 (p<0,01), sehingga dapat disimpulkan bahwa ada hubungan yang sangat signifikan dengan arah positif antara konflik peran ganda dengan stres kerja karyawati yang bekerja di Bank XXX Kanca Dharmasraya