Effects of Recurrent Inclement Winter Weather Cues on White-Throated Sparrows (Zonotrichia albicollis)

Climate change has been linked to an increasing frequency of inclement weather and winter storms. As such, it is important to understand the effects changing weather patterns have on avian species. I investigated the effects of recurrent inclement winter weather cues on glucocorticoid hormones and behaviour of a native Canadian songbird, white-throated sparrows (Zonotrichia albicollis). I used a hypobaric climatic wind tunnel to simulate storms by altering barometric pressure and temperature accordingly, and measured behavioural responses, body composition, and baseline corticosterone levels in birds exposed, or not exposed, to weekly simulated storms. After environmental manipulations, experimental birds had significantly higher fat and lean masses. Baseline corticosterone levels decreased over time in both groups, and time spent at food cups increased over time in both groups as well. Thus, although manipulations did not have a detectable effect on baseline corticosterone, it did affect body composition. This research provides novel experimental evidence that birds detect changing weather patterns and respond appropriately, and indicates that repeated exposure to inclement weather cues directly affects birds’ energy reserves

Weathering the Storm: Physiological and Behavioural Responses of White-Throated Sparrows to Inclement Weather Cues

Changes in weather patterns and extreme weather events are becoming more common with the onset of climate change. This predicted increase in severe weather globally is alarming and it draws concern for the adaptability and ultimate survival of many species. It is clear that birds are able to cope with and respond to inclement weather with physiological and behavioural responses in many circumstances, but as environmental conditions become more severe, the adaptive coping responses of many species may be pushed to their limit. As such, it is important to understand the effects that such changes in environmental conditions will have on birds. Most of our current understanding of how birds respond to inclement weather relies on observational field studies, but these types of studies are unable to draw conclusions about which specific weather variables, or the changes in such variables, are mainly responsible for physiological and behavioural responses. Through experimental studies simulating inclement weather cues, my doctoral research investigated a general question: how do white-throated sparrows (Zonotrichia ablicollis) respond to exposure of inclement weather cues? Within this thesis, I examined the effects of recurrent inclement weather cues (Chapter 2), and also acute exposure to inclement weather cues (Chapter 5) in a controlled setting to investigate the responses of birds to individual weather cues. I also investigated how temperature alone can influence migratory behaviour (Chapter 3). To complement these experimental studies, I also examined the effects that natural storm systems had on birds in a controlled setting (Chapter 4). I found interesting effects that were sex- and season-specific throughout. White-throated sparrows are able to detect changes in both temperature and barometric pressure, and respond to each cue differently depending on the season. For example, exposure to acute changes in temperature alone influenced behavioural responses in spring, but acute exposure to both temperature and barometric pressure elicited a stronger response of both physiological and behavioural measures in the winter. Food availability had limited effects throughout, suggesting that a variety of alternative external and endogenous factors influence the response of birds to storm exposure. Combined, these projects provide further evidence of the complexity of responses of birds to inclement weather, but these responses are dependent upon a variety of factors. Thus, it is difficult to draw a linear conclusion from these studies. This thesis reflects other multi-directional findings within the published literature, highlighting that white-throated sparrows must use a variety of cues to respond to inclement weather, and that multiple other factors including season, sex and food availability can influence this response. However, further research is needed to understand how external and endogenous factors interact to modify birds’ responses to inclement weather

High Rates of Exposure to Simulated Winter Storm Cues Negatively Affect White-Throated Sparrow (Zonotrichia albicollis) Energy Reserves

Birds are often able to cope with, and respond to, inclement weather with physiological and behavioral responses. As storms become more severe or frequent as a result of climate change, the adaptive coping responses of many species may be pushed beyond current tolerance limits. We investigated the effects of experimental recurrent inclement winter weather cues on body composition, glucocorticoid hormones, and behavior of white-throated sparrows (Zonotrichia albicollis). We used a hypobaric climatic wind tunnel to simulate storms by transiently decreasing barometric pressure and temperature, and measured behavioral responses, body composition, and baseline corticosterone levels in birds exposed, or not exposed (control), to different frequencies of simulated storms. In study 1, experimental birds were exposed to one storm per week over 9 weeks. In study 2, experimental birds were exposed to two storms per week over 12 weeks. Birds exposed to one simulated storm per week had higher fat and lean masses than control birds, with no differences in the amount of time groups spent feeding. This change in body composition suggests that birds were coping by increasing energy stores. In contrast, birds exposed to two simulated storms per week had lower fat masses compared to control birds, even though they spent more time feeding. Experimental birds in study 2 also had lower baseline corticosterone levels than controls. These changes suggest that the coping response observed in study 1 was not possible in study 2. These findings provide novel experimental evidence that birds detect and respond to changes in temperature and barometric pressure independent of other storm-related cues. One simulated storm per week resulted in potentially adaptive responses of increased mass. However, increasing the frequency of storm exposure to twice per week exceeded the birds’ capacity to maintain these energy reserves. These results also experimentally demonstrate that repeated exposure to inclement weather cues can directly affect birds’ energy reserves, even in the absence of a storm itself, with strong implications for survival as severe weather events continue to become more prevalent

Fuel Element Structural Design and Manufacture for the Consolidated Edison Thorium Reactor Plant

The design of the fuel-element structure for the CETR is described. Component parts of the assembly comprise the fuel-bundle assembly, the fuel-can assembly, the upper transition, the fuel-element spring, and the upper nozzle and seal assembly. (J.R.D.

Search for CP Violation in the Decay Z -> b (b bar) g

About three million hadronic decays of the Z collected by ALEPH in the years 1991-1994 are used to search for anomalous CP violation beyond the Standard Model in the decay Z -> b \bar{b} g. The study is performed by analyzing angular correlations between the two quarks and the gluon in three-jet events and by measuring the differential two-jet rate. No signal of CP violation is found. For the combinations of anomalous CP violating couplings, ${\hat{h}}_b = {\hat{h}}_{Ab}g_{Vb}-{\hat{h}}_{Vb}g_{Ab}$ and $h^{\ast}_b = \sqrt{\hat{h}_{Vb}^{2}+\hat{h}_{Ab}^{2}}$, limits of \hat{h}_b < 0.59$and$h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st

Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|$\eta$|<0.8) and transverse momentum range 0.2< $p_{\rm T}$< 5.0 GeV/$c$. The elliptic flow signal v$_2$, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 $\pm$ 0.002 (stat) $\pm$ 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v$_2(p_{\rm T})$ reaches a maximum of 0.2 near $p_{\rm T}$ = 3 GeV/$c$. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Superization of Homogeneous Spin Manifolds and Geometry of Homogeneous Supermanifolds

Let M_0=G_0/H be a (pseudo)-Riemannian homogeneous spin manifold, with reductive decomposition g_0=h+m and let S(M_0) be the spin bundle defined by the spin representation Ad:H->\GL_R(S) of the stabilizer H. This article studies the superizations of M_0, i.e. its extensions to a homogeneous supermanifold M=G/H whose sheaf of superfunctions is isomorphic to Lambda(S^*(M_0)). Here G is the Lie supergroup associated with a certain extension of the Lie algebra of symmetry g_0 to an algebra of supersymmetry g=g_0+g_1=g_0+S via the Kostant-Koszul construction. Each algebra of supersymmetry naturally determines a flat connection nabla^{S} in the spin bundle S(M_0). Killing vectors together with generalized Killing spinors (i.e. nabla^{S}-parallel spinors) are interpreted as the values of appropriate geometric symmetries of M, namely even and odd Killing fields. An explicit formula for the Killing representation of the algebra of supersymmetry is obtained, generalizing some results of Koszul. The generalized spin connection nabla^{S} defines a superconnection on M, via the super-version of a theorem of Wang.Comment: 50 page

Genetic and Epigenetic Factors at COL2A1 and ABCA4 Influence Clinical Outcome in Congenital Toxoplasmosis

Background: Primary Toxoplasma gondii infection during pregnancy can be transmitted to the fetus. At birth, infected infants may have intracranial calcification, hydrocephalus, and retinochoroiditis, and new ocular lesions can occur at any age after birth. Not all children who acquire infection in utero develop these clinical signs of disease. Whilst severity of disease is influenced by trimester in which infection is acquired by the mother, other factors including genetic predisposition may contribute.Methods and Findings: In 457 mother-child pairs from Europe, and 149 child/parent trios from North America, we show that ocular and brain disease in congenital toxoplasmosis associate with polymorphisms in ABCA4 encoding ATP-binding cassette transporter, subfamily A, member 4. Polymorphisms at COL2A1 encoding type II collagen associate only with ocular disease. Both loci showed unusual inheritance patterns for the disease allele when comparing outcomes in heterozygous affected children with outcomes in affected children of heterozygous mothers. Modeling suggested either an effect of mother's genotype, or parent-of-origin effects. Experimental studies showed that both ABCA4 and COL2A1 show isoform-specific epigenetic modifications consistent with imprinting.Conclusions: These associations between clinical outcomes of congenital toxoplasmosis and polymorphisms at ABCA4 and COL2A1 provide novel insight into the molecular pathways that can be affected by congenital infection with this parasite