Time Epochs Research Articles

Inhuman, All Too Human: Virginia Woolf and the Anthropocene

Inhuman, All Too Human: Virginia Woolf and the Anthropocene Emma Brush (bio) The idea that we are living in a time of crisis may be less contentious than the claim that we find ourselves in the Anthropocene— a new geological era defined by human impact— but the two often go hand in hand. Dipesh Chakrabarty’s four theses on the “current planetary crisis of climate change” offer one view of the ways in which crisis and Anthropocene have combined to characterize, and disrupt, modern life and understanding.1 According to Chakrabarty, climate change and the accompanying Anthropocene formulation together trouble not only the scale of human history and the scope of what it means to be human but also the potential for a legible future altogether. The need to internalize these conceptual ruptures becomes as urgent as it is difficult— we can no more experience the full force of global impact than we can the life of the species nor the possibility of its extinction. As a result, the Anthropocene concept emerges as a formal challenge and imperative— to come to terms with the facts of planetary crisis, collective interdependence, and the potential elision of futurity— for the sake of living on.2 But however novel, as an environmental condition, the Anthropocene as discourse owes to a longer conceptual lineage— and a particular inheritance, I argue, from literary and artistic modernism— that complicates these claims. The comparison might begin with the rhetoric of newness (the “structural principle of radical rupture,” to quote Susan Stanford Friedman) that reenacts in a different century the modernist imperative to “make it new.”3 The Anthropocene’s “turn toward epochal time” similarly appears in the modernists’ fascination [End Page 69] with the prehistoric, the primeval, and the primordial.4 Indeed, the species thinking prevalent in Anthropocene discourse originates in evolutionary theory, the provocations of which feature prominently in early twentieth-century thought and literature. The millenarian posture of contemporary environmental discourse, meanwhile, evokes a modernist temporality, in which the “past, present, and future exist in a relationship of crisis” in response to perceived decline and looming catastrophe, both increasingly out of control and of humanity’s making.5 Technological advance and the social structures underpinning it play a central role in this narrative of decline and rupture, just as they do for the modernists. As Sarah Cole writes in her study of modernism and violence, “The precariousness of humanity, in the face of a bewildering array of powers— mass violence, totalitarianism, bureaucracy, technology, the onslaught of visuality— is one of the primary morals of the twentieth century.”6 Cole’s framing suggests that the Anthropocene’s basic motif— the impotence of the human faced with the force of humanity’s collective work— derives much from the social and political disruptions of the first half of the twentieth century and the modernist articulations forged in response. Without question, climate change brings unprecedented scientific and technological challenges and beckons perilous social, political, and environmental consequences. But the Anthropocene, as a rhetorical response to climate change and other anthropogenic activity, does not authorize any self-evident ethical or political answers. Modernism’s example “as a discourse of diagnosis and protest, an artistic response to a social problem,” serves as a reminder that such projects need not serve democratic governance nor equitable outcomes.7 A shadow side of modernism was an often-racist reification of nature and place, an offshoot of Darwinism and imperialism that manifested most directly in the form of eugenics and fascism, but also in a wide range of misanthropic, chauvinistic, and primitivist formulations that continue to trouble scholars of the period.8 Anthropologist Andrew Bauer has argued that the Anthropocene might similarly promote “a regressive environmental politics based on romanticized notions of nature,” essentialized versions of humanity, and inequitable forms of knowledge production.9 The larger work of this essay will be to begin to contextualize the figural and rhetorical work performed by the Anthropocene concept within the modernist canon and legacy, in an effort to sharpen [End Page 70] its use and articulate its hazards, with an eye, ultimately, toward better navigating the material conditions the term succeeds in calling into view. As a...

ПАЛЕОСЕЙСМОГЕННЫЕ ТЕКТОНИЧЕСКИЕ РВЫ – УНИКАЛЬНЫЕ АРХИВЫ ИСТОРИИ БЕЛОГО МОРЯ В ГОЛОЦЕНЕ

Various sedimentary archives at the Karelian coast of the White Sea (Kindo Peninsula, White Sea Biological Station area) as the paleoseismic fault trenches filling, marine terraces sections and buried shell lenses have been studied. The results were obtained by applying the paleoseismological approach in course of detailed field studies with the identification of characteristic morphological, structural and dynamic features of ancient earthquakes. The lithostratigraphic study of depositional sequence was verified by radiocarbon, diatom, plant macrofossil analysis of peat and the degree of its decomposition and loss-of-ignition analyzes. It was established that the earthquake that generated the seismic fault trench system occurred in the Late Glacial or Early Holocene with the formation of a seismic underwater fracture, and the trench “opened” because of the subsequent lifting of the bottom, erosion and removal of fragmented rocks in the wave-breaking zone shortly before filling it with Holocene sediments. Sediments that filled the paleoseismic trench accumulated over the period from 9 ka BP to the present, with a break for passage through the coastal zone. They demonstrate a successive change from marine sedimentary environment (gray silt with Hiatella arctica shells, dated back to 9 ka BP) to coastal-marine (sand with clasts), then again to an isolated, gradually desalinated lagoon-type sea gulf (mica silt dated back to 3 ka BP), and ultimately – swamp overgrown with spruce forest (woody peat dated back to 2 ka BP). The structure of the upper part of the section could be caused by a) a weak rise in sea level in the Late Holocene, or b) a weak lowering of the block of the earth’s crust with a seismic trench located on it. New data were obtained on specific features of subfossil malacofauna taphocoenosis formation in the Kandalaksha Bay of the White Sea and on the changes of sedimentation environment under the conditions of rising coast. The traces of strong seismicity in the Late Galcial epoch and postglacial time were discovered. Therefore, a comprehensive approach to the study of seismogenic forms combined with a full range of age-related markers of various paleogeographic events proved to be very productive.

Stochastic modelling and analysis of maximum entropy of <i>M<SUP align="right">X</SUP></i>/<i>G</i>/1 queuing system with balking, startup and vacation interruption

In this paper, a batch arrival single server queuing system with startup, balking and vacation interruption is considered. During the busy period, the customers may join the queue with probability α or may balk with probability 1−. On completion of service, the server goes for vacation when there are no customers available in the queue, otherwise, it resumes service. After a vacation, the server stays idle until the customer arrives and when an arrival occurs, the server begins the startup followed by service. Furthermore, vacation is interrupted suddenly when a customer arrives during vacation and goes for startup and then starts service. The probability generating function of the system size at an arbitrary time epoch is obtained. Various performance measures, some particular cases and cost model are discussed. Moreover, maximum entropy approach is employed and the results are compared with the analytical results, and validated through numerical illustration.

Analysis of customer’s impatience on bulk service queueing system with unreliable server, setup time and two types of multiple vacation

In this investigation, we analyse the customer's impatience on unreliable bulk queueing system with two types of vacation. Depending upon the length of queue, the server is permitted to take two types of vacation called type I vacation and type II vacation. The server is possibly affected by breakdowns and takes considerable time for setup before the repair begins to start. After repair completion, the server will start its remaining service to the batch of customers whose service was interrupted. It could be assumed that the arriving units may be balked from the system when the server is on vacation (type I or type II). By incorporating the supplementary variables technique, the probability generating function of the queue size at an arbitrary and departure time epoch for the designed queueing system are derived. Finally, the stability condition, some performance measures, particular cases are obtained with appropriate numerical illustrations and graphical presentation.

Numerical Study on Transient Behaviour of Finite Bulk Arrival or Service Queues with Multiple Working Vacations

The transient behaviour of single server bulk queues with finite-buffer capacity is discussed numerically under the assumption that the server may take multiple working vacations after completing a busy period. It is considered that the inter-arrival and the service times are exponentially distributed and independent of each other. The buffer space is limited, therefore partial and full batch rejection policies are studied for the bulk arrival queueing model. However, for the batch service, the general bulk service rule is considered. Using probabilistic arguments and relating the state of the systems at two consecutive time epochs, differential equations are obtained to model such phenomena. Further, these equations are solved numerically by Runge-Kutta method and the time dependent numerical solutions are compared with the exact stationary solutions. The blocking probability and the mean waiting time of the first, last and an arbitrary customer are also reviewed mathematically and computed numerically.

Safety and Outcomes of Intravenous tPA in Acute Ischemic Stroke Patients With Prior Stroke Within 3 Months: Findings From Get With The Guidelines-Stroke.

Background Guidelines recommend against the use of intravenous tPA (tissue-type plasminogen activator; IV tPA) in acute ischemic stroke patients with prior ischemic stroke within 3 months. However, there are limited data on the safety of IV tPA in this population. Methods and Results A retrospective observational study of patients ≥66 years of age linked to Medicare claims and treated with IV tPA at Get With The Guidelines-Stroke hospitals (February 2009 to December 2015). We identified 293 patients treated with IV tPA who had a prior ischemic stroke within 3 months and 30 655 with no history of stroke. Patients with prior stroke had a higher stroke severity (median National Institutes of Health Stroke Scale, 11 [6-19] versus 11 [6-18]; absolute standardized difference, 11.2%) and a higher prevalence of cardiovascular comorbidities. Patients with prior stroke had a higher unadjusted risk for symptomatic intracranial hemorrhage (7.7% versus 4.8%) and in-hospital mortality (12.6% versus 8.9%), but these differences were not statistically significant after adjustment. When stratified by prespecified time epochs, the elevated risk for symptomatic intracranial hemorrhage was seen only within the first 14 days (16.3% versus 4.8%; adjusted odds ratio [aOR], 3.7 [95% CI, 1.62-8.43]) but not in other epochs (2.1% versus 4.8%; aOR, 0.38 [95% CI, 0.05-2.79] for 15-30 days and 7.4% versus 4.8%; aOR, 1.36 [95% CI, 0.77-2.40] for 31-90 days). In addition, patients with prior stroke were significantly more likely to have a combined outcome of in-hospital mortality or discharge to hospice (25.9% versus 17.0%; aOR, 1.70 [95% CI, 1.21-2.38]), less likely to be discharged to home (28.3% versus 32.3%; aOR, 0.72 [95% CI, 0.54-0.98]), or to have good functional outcomes at discharge (modified Rankin Scale, 0-1; 11.3% versus 20.0%; aOR, 0.46 [95% CI, 0.24-0.89]). Conclusions Stroke providers need to continue to be vigilant about the safety of IV tPA in patients with prior stroke, particularly those with an event in the previous 14 days.

Extended Periodic Inspection Policies for a Single Unit System Subject to Shocks

In this paper, two types of failures are taken into account to extend the classical periodic inspection policy for a single unit system when it has failed, in which type I failure can be rectified by a minimal repair and type II failure should be removed by a corrective replacement. More specifically, we investigate three extended periodic inspection models for a system subject to two kinds of distinctive shocks, i.e., a general periodic inspection model where the system is checked at periodic time epochs over an infinite time span (Policy A), a periodic inspection model with the consideration of quality warranty where the system is periodically checked within a maximal inspection number (Policy B), and a random periodic inspection model where the system is either periodically checked or randomly checked, whichever takes place first (Policy C). For each extended model, the average maintenance cost in one renewal cycle under special conditions is minimized to seek the optimal inspection interval theoretically and the numerical example is arranged to authenticate it analytically. Last but not least, comparisons are made among the extended models, indicating that the optimum solution varies from policy to policy.

Resolving VLBI correlator ambiguity in the time delay model improves precision of geodetic measurements

Abstract The modern Very Long Baseline Interferometry (VLBI) relativistic delay model, as documented in the IERS Conventions, refers to the time epoch when the signal passes one of two stations of an interferometer baseline (selected arbitrarily from the pair of stations and called the ‘reference station’ or ‘station 1’). This model consists of the previous correlation procedure used before the year 2002. However, since 2002 a new correlation procedure that produces the VLBI group delays referring to the time epoch of signal passage at the geocenter has been used. A corresponding correction to the conventional VLBI model delay has to be introduced. However, this correction has not been thoroughly presented in peer reviewed journals, and different approaches are used at the correlators to calculate the final group delays officially published in the IVS database. This may cause an inconsistency up to 6 ps for ground-based VLBI experiments between the group delay obtained by the correlator and the geometrical model delay from the IERS Conventions used in data analysis software. Moreover, a miscalculation of the signal arrival moment to the ‘reference station’ could result in a larger modelling error (up to 50 ps). The paper presents the justification of the correction due to transition between two epochs elaborated from the Lorentz transformation and the approach to model the uncertainty of the calculation of the signal arrival moment. Both changes are particularly essential for upcoming broadband technology geodetic VLBI observations.

Stochastic modelling and analysis of maximum entropy of <i>M<SUP align="right">X</SUP></i>/<i>G</i>/1 queuing system with balking, startup and vacation interruption

In this paper, a batch arrival single server queuing system with startup, balking and vacation interruption is considered. During the busy period, the customers may join the queue with probability α or may balk with probability 1−. On completion of service, the server goes for vacation when there are no customers available in the queue, otherwise, it resumes service. After a vacation, the server stays idle until the customer arrives and when an arrival occurs, the server begins the startup followed by service. Furthermore, vacation is interrupted suddenly when a customer arrives during vacation and goes for startup and then starts service. The probability generating function of the system size at an arbitrary time epoch is obtained. Various performance measures, some particular cases and cost model are discussed. Moreover, maximum entropy approach is employed and the results are compared with the analytical results, and validated through numerical illustration.

Cost optimisation and maximum entropy analysis of a bulk queueing system with breakdown, controlled arrival and multiple vacations

This article analyses a bulk queueing system with multiple vacations, controlled arrival and breakdown. The service is done in bulk with a minimum of 'a' customers and a maximum of 'b' customers. The server is assigned for secondary jobs (vacations) repeatedly when the number of customers is inadequate to process. The arrivals are accepted with a probability α, β and γ during the busy, vacation and renovation period respectively. During a batch service, if the server breaks down with probability π, the service for the particular batch is processed without interruption. Upon completion of service, the renovation of service station will be considered. The probability generating function for the queue size at an arbitrary time epoch is derived. Various performance measures are obtained. A few particular cases are discussed. Maximum entropy analysis is carried out and validated through numerical illustration. The cost model is also developed to optimise the cost.

Cost optimisation and maximum entropy analysis of a bulk queueing system with breakdown, controlled arrival and multiple vacations

This article analyses a bulk queueing system with multiple vacations, controlled arrival and breakdown. The service is done in bulk with a minimum of 'a' customers and a maximum of 'b' customers. The server is assigned for secondary jobs (vacations) repeatedly when the number of customers is inadequate to process. The arrivals are accepted with a probability α, β and γ during the busy, vacation and renovation period respectively. During a batch service, if the server breaks down with probability π, the service for the particular batch is processed without interruption. Upon completion of service, the renovation of service station will be considered. The probability generating function for the queue size at an arbitrary time epoch is derived. Various performance measures are obtained. A few particular cases are discussed. Maximum entropy analysis is carried out and validated through numerical illustration. The cost model is also developed to optimise the cost.

637: Does time of day of betamethasone administration affect neonatal outcomes?

In adults, administration of exogenous steroids overnight results in greater hypothalamic-pituitary-adrenal (HPA) axis suppression than when given during the day. This finding has not been shown in pregnancy and the consequent effect on neonatal outcomes is not known. The purpose of this study was to evaluate if time of day of betamethasone (BMZ) administration affects neonatal respiratory morbidity outcomes in the late preterm period. We conducted a secondary analysis of a multicenter randomized trial of late preterm BMZ. We included women who received BMZ and were ≥34 weeks at time of enrollment. We excluded major congenital anomalies. The primary outcome was a composite of treatment for respiratory morbidity (continuous positive air pressure or high-flow nasal cannula for ≥ 2 hours, supplemental oxygen for ≥ 4 hours, extracorporeal membrane oxygenation, or mechanical ventilation). Secondary outcomes included composite of major respiratory morbidity and adverse events. Time of day of BMZ administration was approximated by time of randomization and divided into 3 time epochs (epoch 1 – 00:00-07:59, epoch 2 – 08:00-15:59, epoch 3 – 16:00-23:59). Baseline demographics were compared by time epochs. Multivariable logistic regression estimated the association between time of administration and neonatal outcomes, adjusting for statistically or clinically significant baseline confounders. 1,414 women met the inclusion criteria: 131 in epoch 1, 785 in epoch 2, 498 in epoch 3. The groups were similar with the exception of maternal age, indication for steroid administration, and history of previous live-born with respiratory problems at birth (Table 1). After adjusting for confounders, there was no significant difference in outcomes by time of steroid administration. HPA axis suppression due to overnight steroid administration did not significantly influence neonatal outcomes.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Suicide among physicians and health-care workers: A systematic review and meta-analysis.

Medical-related professions are at high suicide risk. However, data are contradictory and comparisons were not made between gender, occupation and specialties, epochs of times. Thus, we conducted a systematic review and meta-analysis on suicide risk among health-care workers. The PubMed, Cochrane Library, Science Direct and Embase databases were searched without language restriction on April 2019, with the following keywords: suicide* AND (« health care worker* » OR physician* OR nurse*). When possible, we stratified results by gender, countries, time, and specialties. Estimates were pooled using random-effect meta-analysis. Differences by study-level characteristics were estimated using stratified meta-analysis and meta-regression. Suicides, suicidal attempts, and suicidal ideation were retrieved from national or local specific registers or case records. In addition, suicide attempts and suicidal ideation were also retrieved from questionnaires (paper or internet). The overall SMR for suicide in physicians was 1.44 (95CI 1.16, 1.72) with an important heterogeneity (I2 = 93.9%, p<0.001). Female were at higher risk (SMR = 1.9; 95CI 1.49, 2.58; and ES = 0.67; 95CI 0.19, 1.14; p<0.001 compared to male). US physicians were at higher risk (ES = 1.34; 95CI 1.28, 1.55; p <0.001 vs Rest of the world). Suicide decreased over time, especially in Europe (ES = -0.18; 95CI -0.37, -0.01; p = 0.044). Some specialties might be at higher risk such as anesthesiologists, psychiatrists, general practitioners and general surgeons. There were 1.0% (95CI 1.0, 2.0; p<0.001) of suicide attempts and 17% (95CI 12, 21; p<0.001) of suicidal ideation in physicians. Insufficient data precluded meta-analysis on other health-care workers. Physicians are an at-risk profession of suicide, with women particularly at risk. The rate of suicide in physicians decreased over time, especially in Europe. The high prevalence of physicians who committed suicide attempt as well as those with suicidal ideation should benefits for preventive strategies at the workplace. Finally, the lack of data on other health-care workers suggest to implement studies investigating those occupations.

Characterizations of random walks on random lattices and their ramifications

We analyze the behavior of a particle moving along a d-dimensional lattice and representing a “doubly stochastic” random walk. Unlike the classical random walk, the lattice is randomly generated upon particle’s landing at a node. At any time, the particle is enclosed in a rectangular cylinder (i.e., with a bounded a-dimensional rectangle Ra at its base) it attempts to escape. Thus, the particle moves from one node to another at random epochs of time and, with some probability, leaves The particle may jump arbitrarily far beyond the boundary at its passage time. Furthermore, the particle’s location is not assumed to be known in real time, but only upon certain random epochs Of a key interest is the location of the particle at any time, where is the linear interpolation of particle’s positions at times τn’s. If denotes the first observed escape time (virtual first passage time), where we target the joint characteristic function of and itself, where or in tractable forms, thereby attempting to enhance as much as possible the probabilistic data lost due to the crudeness of the observations and to couple and with deterministic time intervals Among various applications, we discuss and treat antagonistic games of two active and several passive players as well as situations that occur in complex queueing systems.

Wavelet-based combination approach for modeling sub-divisional rainfall in India

Agriculture in India is highly sensitive to climatic variations particularly to rainfall and temperature; therefore, any change in rainfall and temperature will influence crop yields. An understanding of the spatial and temporal distribution and changing patterns in climatic variables is important for planning and management of natural resources. Time series analysis of climate data can be a very valuable tool to investigate its variability pattern and, maybe, even to predict short- and long-term changes in the series. In this study, the sub-divisional rainfall data of India during the period 1871 to 2016 has been investigated. One of the widely used powerful nonparametric techniques namely wavelet analysis was used to decompose and de-noise the series into time–frequency component in order to study the local as well as global variation over different scales and time epochs. On the decomposed series, autoregressive integrated moving average (ARIMA) and artificial neural network (ANN) models were applied and by means of inverse wavelet transform, the prediction of rainfall for different sub-divisions was obtained. To this end, empirical comparison was carried out toward forecast performance of the approaches namely Wavelet-ANN, Wavelet-ARIMA, and ARIMA. It is reported that Wavelet-ANN and Wavelet-ARIMA approach outperforms the usual ARIMA model for forecasting of rainfall for the data under consideration.

Satellite Orbital Drag During Magnetic Storms

AbstractWe investigate satellite orbital drag effects at low‐Earth orbit associated with thermosphere heating during magnetic storms caused by coronal mass ejections. CHAllenge Mini‐satellite Payload (CHAMP) and Gravity Recovery And Climate Experiment (GRACE) neutral density data are used to compute orbital drag. Storm‐to‐quiet density comparisons are performed with background densities obtained by the Jacchia‐Bowman 2008 (JB2008) empirical model. Our storms are grouped in different categories regarding their intensities as indicated by minimum values of the SYM‐H index. We then perform superposed epoch analyses with storm main phase onset as zero epoch time. In general, we find that orbital drag effects are larger for CHAMP (lower altitudes) in comparison to GRACE (higher altitudes). Results show that storm time drag effects manifest first at high latitudes, but for extreme storms, particularly observed by GRACE, stronger orbital drag effects occur during early main phase at low/equatorial latitudes, probably due to heating propagation from high latitudes. We find that storm time orbital decay along the satellites' path generally increases with storm intensity, being stronger and faster for the most extreme events. For these events, orbital drag effects decrease faster probably due to elevated cooling effects caused by nitric oxide, which introduce modeled density uncertainties during storm recovery phase. Errors associated with total orbit decay introduced by JB2008 are generally the largest for the strongest storms and increase during storm times, particular during recovery phases. We discuss the implication of these uncertainties for the prediction of collision between space objects at low‐Earth orbit during magnetic storms.

Analysis of $GI^{[X]}/D$-$MSP/1/\infty$ queue using $RG$-factorization

<p style='text-indent:20px;'>This paper analyzes an infinite-buffer single-server queueing system wherein customers arrive in batches of random size according to a discrete-time renewal process. The customers are served one at a time under discrete-time Markovian service process. Based on the censoring technique, the UL-type <inline-formula><tex-math id="M1">\begin{document}$ RG $\end{document}</tex-math></inline-formula>-factorization for the Toeplitz type block-structured Markov chain is used to obtain the prearrival epoch probabilities. The random epoch probabilities are obtained with the help of classical principle based on Markov renewal theory. The system-length distributions at outside observer's, intermediate and post-departure epochs are obtained by making relations among various time epochs. The analysis of waiting-time distribution measured in slots of an arbitrary customer in an arrival batch has also been investigated. In order to unify the results of both discrete-time and its continuous-time counterpart, we give a brief demonstration to get the continuous-time results from those of the discrete-time ones. A variety of numerical results are provided to illustrate the effect of model parameters on the performance measures.

LARGE DEVIATIONS FOR THE LONGEST GAP IN POISSON PROCESSES

The longest gap $L(t)$ up to time $t$ in a homogeneous Poisson process is the maximal time subinterval between epochs of arrival times up to time $t$; it has applications in the theory of reliability. We study the Laplace transform asymptotics for $L(t)$ as $t\rightarrow \infty$ and derive two natural and different large-deviation principles for $L(t)$ with two distinct rate functions and speeds.

On a class of spatial renewal processes: Renewal processes synchronization probabilities

We mainly focus on the sojourn boxes in spatial renewal processes. On sojourn boxes, the components of a multivariate renewal process are synced together. We provide formulations for the probability that the components to be synced at a multivariate time epoch, and for the average number of synced cases. Then, we introduce a new spatial renewal process by restricting a spatial renewal process to its sojourn boxes, and derive the limiting behavior of the corresponding multivariate renewal function, and cumulative function of synced probability along rays initiated from the origin. Examples are provided as well.

P5. Abstract Title: Characterization of Unfractionated Heparin Infusions in a Comprehensive Stroke Centre

<h3>Introduction</h3> Stroke patients with arterial or venous intraluminal thrombus (ILT) are at high risk of stroke recurrence and embolic or hemorrhagic complications. Treatment with anticoagulation remains challenging in this group of patients due to onset of action, efficacy, and risk of hemorrhage. Traditionally, unfractionated heparin (UFH) has been used due to its short half-life in the context of risk of hemorrhagic transformation of the infarct zone. Heparin nomograms and associated bolus dosing are not standardized in clinical practice across centres and patients can exhibit long epochs of time under or over the therapeutic PTT range. Thus, resulting in suboptimal protection and added risk of hemorrhage respectively. We aim to characterize the use and efficacy of UFH infusion in cerebrovascular conditions at a large academic comprehensive stroke centre. <h3>Methods</h3> A retrospective analysis from 2017 to 2019 was conducted at Sunnybrook Health Sciences Centre (SHSC) on adult patients in either critical care or stroke units with UFH infusion for ILT and other cerebrovascular etiologies. We characterized use-cases and stroke etiology. PTT values were extracted from patient profiles for the duration of UFH infusion. These values were used to find the duration of time in target PTT range (70-90.9 sec); subtherapeutic (PTT<70 sec); and supratherapeutic (PTT>90.9 sec) epochs. Duration of time above theraputic PTT and mean values were measured. Where possible, we also correlated with clinical parameters and imaging findings. <h3>Expected Results</h3> In regards to PTT, we expect a significant amount of time spent in the subtherapeutic and/or supratherapeutic ranges, compared to target range. <h3>Conclusion</h3> There is limited evidence for the scope and efficacy of UFH infusions from a therapeutic perspective in stroke patients admitted to a comprehensive stroke centre. Future research efforts should be directed towards the utilization of other anticoagulation therapies, such as low molecular weight heparins (LMWH), with appropriate dosing that offers reliable, efficacious, and safe anticoagulation.