Developmental stress in birds: phenotypic and fitness

The environment animals experience during development can have important effects on phenotype, performance, and fitness across multiple life-history stages. Environmental cues experienced during development can provide information to animals about the environment they will soon inhabit and promote phenotypic changes which affect fitness. Increasing evidence suggests that physiological stress may be one such cue that conveys environmental information to developing animals. Here, I explore the short- and long-term consequences of developmental stress in captive and free-living birds. In chapter one, I explore the effects of developmental stress on body size and physiological stress responses across life-history stages in zebra finches (Taeniopygia guttata). I found that developmental stress increases stress response and decreases body size in juvenile zebra finches. In chapter two, I examine the effects of developmental stress on learning in zebra finches. Developmental stress has well-known suppressive effects on song learning in passerines. I examine whether this is generalizable for other types of learning, specifically learning that relates to foraging. I found that adult zebra finches exposed to developmental stress learned a novel foraging task faster compared to control siblings. In chapter three, I investigated the effects of developmental stress on male reproductive success in zebra finches. I found that developmentally stressed males invested more in parental care and reared nestlings in better condition compared to control males. Developmentally stressed males also sired more offspring and were less likely raise non-genetic nestlings compared to control males. In chapters four and five, I explore the causes and consequences of stressors in a free-living model species, the white-crowned sparrow (Zonotrichia leucophryus oriantha). I examine the effects of an anthropogenic stressor (a high traffic road) on nestling stress responses, growth, and survival. I found that proximity to a road increased both nest failure due to predation and nestling stress responses. Cumulatively, these studies expand our understanding of the phenotypic and fitness consequences of developmental stress. In contrast to most studies, I find several beneficial outcomes in response to developmental stress. Hence, early life stress appears to shape phenotype and performance in some ways that are beneficial

A Group Theoretic Tabu Search Methodology for Solving the Theater Distribution Vehicle Routing and Scheduling Problem

The application of Group Theory to Tabu Search is a new and exciting field of research. This dissertation applies and extends some of Colletti\u27s (1999) seminal work in group theory and metaheuristics in order to solve the theater distribution vehicle routing and scheduling problem (TDVRSP). This research produced a robust, efficient, effective and flexible generalized theater distribution model that prescribes the routing and scheduling of multi-modal theater transportation assets to provide economically efficient time definite delivery of cargo to customers. In doing so, advances are provided in the field of group theoretic tabu search and its application to difficult combinatorial optimization problems, e.g., the multiple trip multiple services vehicle routing and scheduling problem with hubs and other defining constraints

Globalization and mental distress

We study the effects of import competition on workers' mental distress, using unique longitudinal data on mental health for British residents, coupled with measures of import competition in more than 100 industries over 1995\u20132007. We find that import competition has a large negative impact on individual mental health. Compared to a worker employed in the industry at the 25th percentile of the import competition distribution, a worker employed in the industry at the 75th percentile would need a yearly monetary compensation of \ua3270 to make up for her greater utility loss. We find import competition to have larger effects on the right tail of the mental distress distribution, thereby increasing inequality in mental health not only across but also within industries. We show that this is consistent with import competition disproportionately hitting specific groups of workers in an industry, such as the youngest or those with a large family, a poor financial condition, a short job tenure, a temporary contract, and a blue-collar or tradable job. Using information on family ties, we find that import competition has negative spillovers to other family members. In particular, women's mental distress increases as a consequence of the import competition faced by their partners. Moreover, paternal import competition leads to reduced investment in child rearing and worsened children's self-esteem and life satisfaction. Finally, we provide evidence that import competition is likely to work through a complex set of channels. These include observable labor market outcomes such as higher likelihood of job displacement and lower wage growth, but also reduced job satisfaction and gloomier expectations about the future

Endoscopic Ultrasound Guided Gallbladder Interventions: a Review of the Current Literature

Interventional endoscopic ultrasound (EUS) is a rapidly expanding field with a wide variety of indications, including different drainage procedures and delivery of locoregional treatment mainly for pancreatic solid tumors. Transgastric or transduodenal gallbladder drainage in high-risk patients with acute cholecystitis or biliary decompression in patients with unresectable distal biliary malignant obstruction who failed endoscopic retrograde colangiography is one of the newest areas of EUS-guided intervention. The large-caliber lumen apposing metal stents placed during these procedures allow direct endoscopic gallbladder access and the possibility of performing gallstone treatment or resection of mucosal polyps. The current review presents the indications of endoscopic gallbladder interventions and discusses the results of available studies, foreseeing future potential applications

A novel androgen-regulated isoform of the TSC2 tumour suppressor gene increases cell proliferation

TSC2 (Tuberous sclerosis complex 2) is an important tumour suppressor gene, mutations within which are linked to the development of tuberous sclerosis and implicated in multiple tumour types. TSC2 protein complexes with TSC1 and blocks the ability of the Rheb (Ras homolog enriched in brain) GTPase to activate mTOR (mammalian target of rapamycin), a crucial signal transducer which regulates protein synthesis and cell growth. Here, we report the characterisation of a novel isoform of TSC2 which is under direct control of the ligand-activated androgen receptor. TSC2 isoform A (TSC2A) is derived from an internal androgen-regulated alternative promoter and encodes a 508-amino acid cytoplasmic protein corresponding to the C-terminal region of full-length TSC2, lacking the interaction domain for TSC1 and containing an incomplete interaction domain required for Rheb inactivation. Expression of TSC2A is induced in response to androgens and full-length TSC2 is co-ordinately down-regulated, indicating an androgen-driven switch in TSC2 protein isoforms. In contrast to the well-characterised suppressive effect on cell proliferation of full-length TSC2 protein, both LNCaP and HEK293 cells over-expressing TSC2 isoform A proliferate more rapidly (measured by MTT assays) and have increased levels of cells in S-phase (measured by both Edu staining and FACS analysis). Our work indicates, for the first time, a novel role for this well-known tumour suppressor gene, which encodes an activator of cell proliferation in response to androgen stimulation

Automated Brittle Fracture Rate Estimator for Steel Property Evaluation Using Deep Learning After Drop-Weight Tear Test

This study proposes an automated brittle fracture rate (BFR) estimator using deep learning. As the demand for line-pipes increases in various industries, the need for BFR estimation through dropweight tear test (DWTT) increases to evaluate steel's property. Conventional BFR or ductile fracture rate (DFR) estimation methods require an expensive 3D scanner. Alternatively, a rule-based approach is used with a single charge-coupled device (CCD) camera. However, it is sensitive to the hyper-parameter. To solve these problems, we propose an approach based on deep learning that has recently been successful in the fields of computer vision and image processing. The method proposed in this study is the first to use deep learning approach for BFR estimation. The proposed method consists of a VGG-based U-Net (VU-Net) which is inspired by U-Net and fully convolutional network (FCN). VU-Net includes a deep encoder and a decoder. The encoder is adopted from VGG19 and transferred with a pre-trained model with ImageNet. In addition, the structure of the decoder is the same as that of the encoder, and the decoder uses the feature maps of the encoder through concatenation operation to compensate for the reduced spatial information. To analyze the proposed VU-Net, we experimented with different depths of networks and various transfer learning approaches. In terms of accuracy used in real industrial application, we compared the proposed VU-Net with U-Net and FCN to evaluate the performance. The experiments showed that VU-Net was the accuracy of approximately 94.9 %, and was better than the other two, which had the accuracies of about 91.8 % and 93.7 %, respectively.11Ysciescopu