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Structure and succession of salt marsh decomposer communities in Minas Basin, Nova Scotia
No full textCoastal salt marshes are distinctive ecosystems known for providing many ecosystem services, however little is known of the biology of decomposer taxa in these systems. This study employed a litter bag experiment to characterize the fungal and mite communities associated with the dominant salt marsh grass, Sporobolus pumilus, in the Minas Basin, Nova Scotia. Decomposition rates of above-ground and below-ground tissues, and environmental variables were quantified to contextualize temporal patterns in community composition. Litter bag mass loss peaked in July, which positively correlated with fungal richness. Seventeen fungal species and 26 mite species were encountered. The fungal species were described in this study. Fungal and mite richness displayed inverse relationships over time, suggesting the presence of a complex detrital network that extends beyond decomposition of salt marsh grasses. Overall, this preliminary study offers a first look at decomposer biodiversity associated with S. pumilus in Canada
Island selection and nest site partitioning by common, Arctic, and Roseate Terns in the Northwest Atlantic
No full textPatterns of habitat use do not necessarily reveal optimal choice, so habitat selection studies should relate habitat use to reproductive success to reveal processes critical to the evolution of habitat choice behaviour.
In Lobster Bay, Nova Scotia, I conducted a study of habitat use and selection by Common Terns (Sterna hirundo), Arctic Terns (S. paradisaea), and Roseate Terns (S. dougallii) at two spatial scales: 1) island-level selection, and 2) nest-site selection. For four years and across 97 similar islands, the absence of trees was the most important factor predicting island use by terns and used islands were also generally less elevated than those not used. I studied the amount of lateral cover, the number of different sized rocks, and the amount of inter and intraspecific nest density from 292 nests in a colony of Common, Arctic, and Roseate Terns. I examined whether the species partitioned habitat at a fine spatial scale and I compared these characteristics between used sites and available sites and between successful and unsuccessful nests for each species.
My results indicated that all three species partitioned habitat based on physical characteristics like lateral cover and large rocks and biological features (nearby density of nesting terns). I found that high lateral cover was an important feature for nest site selection of both Common Terns and Roseate Terns. Common Terns had higher nest success with greater interspecific nest density (i.e. density of Roseate and Arctic tern nests)
within 2 m, possibly via reduced predation pressure by gulls (Larus spp.) in areas with dense tern nesting. A similar trend was observed for Roseate and Arctic terns, although it was much less pronounced than in Common Terns. Overall, my results suggest that mixed species colonies of terns can provide fitness advantages to each species, and that Common, Arctic, and Roseate Terns nesting in the Northwest Atlantic have evolved habitat preferences that serve to reduce competition in dense colonies
Sales forecasting using long short term memory networks
No full textThe Annapolis Cider Company would like to estimate their future hourly and daily sales based on their historical sales, date and time, weather conditions and knowledge of special events in Annapolis Valley. This study uses machine learning methods to predict hourly and daily sales for up to two days in advance. The Annapolis Cider Company has provided sales data stored in their POS system for up to four years. Both observed and forecast weather data have been retrieved from the Dark Sky website. Special event data has been extracted from various online calendars from the web. This study focues on the performance of LSTM neural networks compared to ARIMA, persistence and Avg6Week models. Mean absolute error (MAE) and mean absolute percentage error (MAPE) are used to evaluate the performance of each model. The LSTM daily prediction model provides the lowest test MAE of 51.59 and MAPE of 40.8% on an hourly basis, which is 17.2% lower than the persistence hourly model
Using DNA barcodes to review the taxonomy of water and pygmy shrews in Canada
No full textThe American water shrew (Sorex palustris Richardson, 1828) and the American pygmy shrew (S. hoyi Baird, 1857) have two or more distinct clades in North America. Sorex hoyi is divided into an Eastern and Western clade; S. palustris is divided into Boreal, Cordilleran and Eastern clades. Previous studies have used Cytochrome b sequence data from the mitochondrial genome to attempt to determine if the subspecies associated with these clades warranted species status. In this study, cytochrome oxidase subunit 1 sequence data are tested to see whether two putative species, the eastern water shrew (S. albibarbis [Cope, 1862]), and Thompson's pygmy shrew (S. thompsoni [Baird 1858]), are supported as separate species from their respective species complexes. DNA sequences of Cytochrome oxidase were downloaded from Genbank, n=14 for S. palustris and n=23 for S. hoyi. These were then used for phylogenetic tree construction and pairwise distance comparisons. The results from the analysis found for S. palustris the Boreal and Eastern clades had bootstrap support of 98-100% as was a Kimura-2-Parameter (K2P) pairwise distances of 4.98%. For S. hoyi, bootstrap support was 93% for the western clade and 83% for the eastern clade with a distance of 2.23% between the clades. The Cytochrome oxidase data did provide support to the species status of S. albibarbis of the Eastern from S. palustris of the Boreal clade with indirect support for S. navigator
of the Cordilleran clade. The sequence data did not have enough divergence or confidence for S. hoyi to support species status for S. h. thompsoni of the eastern clade
Aboriginal people and the Charter of Rights and Freedoms: is Section 25 an untapped means to claim contemporary rights?
No full textThis thesis reviews the historical and contemporary relationship between indigenous people and the state, highlighting the institutionalization of indigenous people as second-class citizens, and the consequences of this hierarchical categorization through national reports, statistics and firsthand accounts. An analysis of foundational documents and relevant jurisprudence including the Canadian Charter of Rights and Freedoms, R v. Knapp (2008) and Haig v. Canada (1993) is completed for to establish a framework for the activation of s.25 in a way that allows indigenous people to claim positive contemporary rights. The thesis also includes an analysis of the Canadian Human Rights Tribunal (CHRT) case (2016) which found that the government discriminates against
indigenous people in the management and delivery of child welfare services. This case provides evidence of state orchestrated discrimination and is used to apply the reimaged s.25 framework
to allow for the CHRT 2016 case to be adjudicated as a Charter case
Evaluating bias in alewife sex-ratio within the upper reaches of the Lacoupe, Laplanche and Missaquash rivers, Isthmus of Chignecto, NB, Canada
No full textAlewife (Alosa pseudoharengus) is an anadromous fish that spawn between late April-July in freshwater lakes in the Isthmus of Chignecto, NB, Canada. Alewife populations support both recreational and commercial fisheries for food and bait fisheries. These fish are major vectors of marine derived nutrients into coastal freshwater systems. Rivers within the Isthmus of Chignecto have been heavily influenced by the construction of culverts dams, and tide gates which may delay or impede the movements of alewives. Differential success in navigating barriers has the potential to bias
upstream sex ratios in preferred spawning grounds. Using data collected during tagging and sampling activities between 2016-2019 from estuarine sites (n=3658), freshwater riverine sites (n=914), and a known spawning site (n=201) were used to document sex ratios. The spawning run was split into early (April 24 -15 May), mid (16 May -6 June,), and late (7 June -28 June) periods, including
all fish captured in each year. Male to female sex ratios in estuary study sites were not significantly different (ANOVA, p>0.05). Sex ratios at estuarine sites did not differ significantly during the early, mid and late periods (ANOVA, p>0.05). A general linear model with binomial distribution was used to examine if the probability of passage success through three fishways as a function of sex, total
length, returnees, and site. It was found that with increasing total length, fish passage increased significantly. Returnees also differed significantly from first time spawners and were more successful in passing the fishways which was also found by Nau et al (2017) in the Isthmus of Chignecto between 2013 –2016. Sex was not a significant factor in determining passage success. However, trends show that males are better at passing tide gates than females. This is likely due to the relative muscle of males compared to females. Future research should focus on the analysis of telemetry data
at tide gates and antenna array sites throughout the river to identify sources of potential sex bias
Exploring differential gene expression in Striped Bass (Morone saxatilus) in response to mercury exposure
No full textMature Striped Bass, (Morone saxatilis) feed on high trophic level prey, enabling biomagnification of contaminants such as mercury. Mercury is a non-essential heavy metal existing in several forms in aquatic environments and produces various toxic effects in organisms. In this study, the expression of genes coding for antioxidants involved in the oxidative stress response and detoxification, specifically glutathione S-transferase, metallothionein, and thioredoxin reductase in Striped Bass, were examined. Total mercury levels in liver tissues, received in coordination with local fishers in Nova Scotia, were measured using thermal decomposition, gold amalgamation and atomic absorption spectrometry. Real time quantitative polymerase chain reaction and the ∆∆Cq method was used to calculate relative normalized expression of target genes in comparison to the reference, elongation factor 1-alpha.Total mercury levels in liver tissues increased with total length of Striped Bass, indicative of bioaccumulation. No statistically significant relationships were initially observed regarding the expression of target genes and mercury concentration in Striped Bass liver. Metallothionein
gene expression exhibited a statistically significant positive relationship with mercury concentration after outlier removal and may serve as a potential biomarker of mercury exposure. This study is the first to show differential expression of novel genes involved in the oxidative stress response and detoxification processes in Striped Bass in response to mercury contamination
Exploring the use of face video to measure mental health
No full textCovid-19 frontline workers are at risk for depression, moral injury, and suicide. People who need help are often reluctant to seek help, and so a mechanism for detecting emotional distress from face video could be part of a more comprehensive plan to detect and treat mental distress in frontline workers. Here we explore the potential application of face video analysis to detect depression CESD-R), attachment style (ECR-RS), mood (POMS-SF), and empathy (EQ) in an undergraduate student population. Face video was collected remotely using iMotions software. Facial expressions
and Eye Blink Rate (EBR) were measured using the AFFDEX automated facial affect coding algorithm and an R script. Facial responses were measured while watching a video, speaking a narrative, and performing a range of face imitation tasks. The face imitation tasks consisted of making emotional faces on command (COMMAND), imitating videos of facial expressions from one of four models (IMITATE), and making the opposite expression (OPPOSITE). These tasks were repeated in two conditions: a POSITIVE VALENCE condition, featuring a positive video and narratives in
response to questions about YouTube, and a NEGATIVE VALENCE condition, featuring a Covid-19 news video and narratives in response to questions about Covid-19. For the preliminary analysis, we looked at expression of joy vs. fear across all conditions, as well as EBR. There were more expressions, p = .016, and micro expressions, p = .038, of joy during the positive videos. In all of the motor tasks, AFFDEX was much stronger at detecting expressions of joy, p< .001. EBR was lower during the surveys than during both narratives and the negative video, p < .001
Vertical ground reaction force asymmetries in male and female athletes across four athletic tasks
No full textMotor asymmetries are naturally occurring phenomena that may result from longstanding participation in sport and athletic activity. Ground reaction forces (GRF) produced by athletes
through tasks such as cutting, running, and landing on one or two legs yield various levels of asymmetry when comparing one leg to the other. Certain levels of asymmetry may increase the risk of injury to an athlete if not addressed and remediated. The purpose of this study was to identify and compare the level of asymmetries across various athletic tasks in males and females of contact (male football and female rugby), soccer, and basketball sport backgrounds while qualitatively comparing three different symmetry indices including; the Symmetry Index (SI), Symmetry Angle (SA), and Normalized Symmetry Index (NSI). Data were collected in the John MacIntyre motion Laboratory of Applied Biomechanics (mLAB) located in the Athletic Complex of Acadia University in Wolfville, Nova Scotia, Canada. The cohorts included: male contact (football), female contact (rugby), male soccer, female soccer, male basketball, and female
basketball. The athletes performed a sub-maximal run, an unanticipated cut to change direction,and double leg and single leg drop landings. Data collection involved capturing muscle activity,
ground reaction forces, and 3D marker position for each participant, however only vertical forces were analyzed in this study. Using MATLAB, symmetry index values were tabulated for the peak
vertical ground reaction force (vGRF) through the stance phases of the run and cut, and the landing phases of a double and single leg drop jumps, referred to as double leg landings and single leg landings. RStudio was used to calculate means and standard deviations and then create two-factor gamma generalized linear models (GLM) for each task for sex and sport. A Wald chi-
squared test was performed on the GLMs to identify significant main or interaction effects. If a significant effect was found (p < 0.05), a pairwise comparison test was conducted using the Tukey p-value adjustment method to reveal the levels of the main effects. This study found that through a cutting and running task, males produced significantly greater asymmetries than females.
In the cutting task, contact athletes produced significantly greater asymmetries than basketball athletes. In the running task, basketball athletes produced significantly greater asymmetries than soccer athletes. Significant differences were not evident through the double leg landing and single leg landing tasks. The present findings may help address the injury implications of vGRF asymmetries within high school and university athletes, while providing a qualitative understanding of various symmetry indices