The even darker side of the eastern gray squirrel (Sciurus carolinensis): a review of global introductions, invasion biology, and pest management strategies

Huynh, H.M., Bertolino, S., Lurz, P.W.W., Koprowski, J.L., Williams, G.R., Thompson, C.W., McAlpine, D.F

Fundamental issues in antenna design for microwave medical imaging applications

This paper surveys the development of microwave medical imaging and the fundamental challenges associated with microwave antennas design for medical imaging applications. Different microwave antennas used in medical imaging applications such as monopoles, bow-tie, vivaldi and pyramidal horn antennas are discussed. The challenges faced when the latter used in medical imaging environment are detailed. The paper provides the possible solutions for the challenges at hand and also provides insight into the modelling work which will help the microwave engineering community to understand the behaviour of the microwave antennas in coupling media

Encouragement for Further Study of Tranexamic Acid Administration for Sacroiliac Joint Fusion Surgery.

We read with great interest the article by Huynh et al.regarding the association between tranexamic acid (TXA) and blood loss in patients undergoing surgical treatment for hip fracture (Huynh PAN, Miller M, Will R. Intravenous Tranexamic Acid Decreases Blood Transfusions and Blood Loss for Patients with Surgically Treated Hip Fractures. Geriatric Orthopedic Surg Rehabil. 2021). The authors illustrated, via retrospective chart review of 505 patients who were surgically treated for hip fractures, that patients administered TXA had statistically significant decreases in perioperative blood loss and reduced relative risk of transfusion. Huynh et al. reported no statistically significant increases in thromboembolic events in patients given TXA. Mechanistically, TXA is a synthetic anti-fibrinolytic that competitively inhibits the plasminogen activation pathway. By preventing activated plasmin from de-stabilizing the fibrin matrix, TXA promotes clot formation. Given the anti-fibrinolytic effects of TXA, concerns in the literature exist regarding its use being associated with increased risk for thromboembolic events. However, it is important to note the complication profile associated with TXA is minimal, as elucidated by Brown et al., specifically finding that no patients who were administered TXA perioperatively experienced a thromboembolic event (or at least, there were no reports of thromboembolism or any other adverse events). While administration of TXA may theoretically increase the risk for thrombosis, Brown et al. showed this does not seem to occur in spinal laminectomy and fusion with posterior instrumentation. Similarly, in a systematic review of the literature describing TXA use in intracranial tumor resection, this study revealed a statistically significant reduction in the need for intraoperative blood transfusion in patients administered TXA. Upon consideration of postoperative outcomes, no significant increase in complication rate was found. This evidence in the existing literature on TXA use in orthopedic, spinal, and cranial neurosurgery exemplifies the wide potential of TXA for reducing blood loss with minimal complications in surgical procedures, especially involving the craniospinal axis

Simulation of Buoyancy Driven and Winddriven Ventilation Flow in a Three Dimensional Room Fitted with a Windcatcher

© 2018 Australasian Fluid Mechanics Society. All rights reserved. Natural ventilation is the process of supplying and removing air through an indoor space by natural means. There are two types of natural ventilation occurring in buildings: winddriven ventilation and buoyancy driven or stack ventilation. Combining the wind driven and the buoyancy driven ventilation will be investigated in this study through the use of a windcatcher natural ventilation system. As stack driven air rises leaving the windcatcher, it is replaced with fresh air from outside entering through the positively pressured windward side. To achieve this, CFD (computational fluid dynamics) tool is used to simulate the air flow in a three dimensional room fitted with a windcatcher based on the winddriven ventilation alone, and combined buoyancy and winddriven ventilation. A three dimensional real sized room with a length of 5 m, a width of 4 m and a height of 3 m fitted with a windcatcher is modeled in this study using Ansys Fluent. The combined, buoyancy driven and winddriven ventilation, has provided approximately 3.16% increase in the total air flow rate, when heat flux of 500 W/m2 is applied at the front and bottom walls of the windcatcher’s outlet compared to the winddriven ventilation only. The pattern of air flow through the room has provided full ventilation at 1.2 m height where most of the human occupancy occurs

Extremal Problems for Subset Divisors

Let $A$ be a set of $n$ positive integers. We say that a subset $B$ of $A$ is a divisor of $A$, if the sum of the elements in $B$ divides the sum of the elements in $A$. We are interested in the following extremal problem. For each $n$, what is the maximum number of divisors a set of $n$ positive integers can have? We determine this function exactly for all values of $n$. Moreover, for each $n$ we characterize all sets that achieve the maximum. We also prove results for the $k$-subset analogue of our problem. For this variant, we determine the function exactly in the special case that $n=2k$. We also characterize all sets that achieve this bound when $n=2k$.Comment: 10 pages, 0 figures. This is essentially the journal version of the paper, which appeared in the Electronic Journal of Combinatoric

Teknik Peer Instruction dengan Analisis Sumber-Sumber Sejarah: Kekekalan Kemahiran Pemikiran Kritikal?

Kajian eksperimental ini bertujuan untuk mengenal pasti kesan teknik Peer Instruction dengan analisis sumber-sumber sejarah terhadap kekekalan kemahiran berfikir kritikal. Seramai 25 orang murid Tingkatan Empat melalui teknik persampelan bertujuan terlibat dalam kajian ini. Instrumen ujian pemikiran kritikal yang diadaptasi yang telah disahkan pakar penilai dan mempunyai nilai kebolehpercayaan yang baik merupakan instrumen kajian ini. Data kajian ini dianalisis secara inferensi iaitu ujian ANOVA Satu Hala dengan pengukuran berulang melalui perisian IBM SPSS. Dapatan kajian ini menunjukkan bahawa teknik Peer Instruction dengan analisis sumber-sumber sejarah adalah berkesan terhadap kekekalan kemahiran berfikir kritikal dalam kalangan murid. Implikasi kajian ini telah mencadangkan kepada guru-guru Sejarah pada semua peringkat persekolahan untuk melaksanakan teknik Peer Instruction dengan analisis sumber-sumber sejarah untuk memupuk kemahiran berfikir kritikal yang beterusan dalam kalangan murid

An Agent Based Model for the Simulation of Transport Demand and Land Use

Agent based modelling has emerged as a promising tool to provide planners with insights on social behaviour and the interdependencies characterising urban system, particularly with respect to transport and infrastructure planning. This paper presents an agent based model for the simulation of land use and transport demand of an urban area of Sydney, Australia. Each individual in the model has a travel diary which comprises a sequence of trips the person makes in a representative day as well as trip attributes such as travel mode, trip purpose, and departure time. Individuals are associated with each other by their household relationship, which helps define the interdependencies of their travel diary and constrains their mode choice. This allows the model to not only realistically reproduce how the current population uses existing transport infrastructure but more importantly provide comprehensive insight into future transport demands. The router of the traffic micro-simulator TRANSIMS is incorporated in the model to inform the actual travel time of each trip and changes of traffic density on the road network. Simulation results show very good agreement with survey data in terms of the distribution of trips done by transport modes and by trip purposes, as well as the traffic density along the main road in the study area

Influence of Pacing Strategy on Oxygen Uptake During Treadmill Middle-Distance Running

The oxygen uptake (V·O2) attained during a constant speed 800-m pace trial on a treadmill is less than the maximal V·O2 (V·O2max) in male middle-distance runners with a high V·O2max (i.e., > 65 ml · kg-1 · min-1). We therefore investigated whether the V·O2 attained was influenced by the pacing strategy adopted. Eight male middle-distance runners (age 25.8 ± 3.3 years; height 1.78 ± 0.10 m; mass 67.8 ± 4.7 kg) with a personal best 800-m time of 112.0 ± 3.3 s volunteered to participate. Subjects undertook a speed ramped progressive test to determine V·O2max and three 800-m pace runs to exhaustion all in a randomised order. The three 800-m pace runs included constant speed, acceleration, and race simulation runs. Oxygen uptake was determined throughout each test using 15-s Douglas bag collections. Following the application of a 30-s rolling average, the highest V·O2 during the progressive test (i.e., V·O2max) and the highest V·O2 during the 800-m pace runs (i.e., V·O2peak) were compared. For the eight runners, V·O2max was 67.2 ± 4.3 ml · kg-1 · min-1. V·O2peak was 60.1 ± 5.1 ml · kg-1 · min-1, 61.1 ± 5.2 ml · kg-1 · min-1, and 62.2 ± 4.9 ml · kg-1 · min-1, yielding values of 89.3 ± 2.4 %, 90.8 ± 2.8 %, and 92.5 ± 3.1 % V·O2max for the constant speed, acceleration and race simulation runs, respectively. Across runs, repeated measures ANOVA revealed a significant effect (p = 0.048). Trend analysis identified a significant linear trend (p = 0.025) with the % V·O2max attained being higher for the acceleration run than the constant speed run, and higher still for the race simulation run. These results demonstrate that in middle-distance runners a) pacing strategy influences the V·O2 attained, with a race simulation run elevating the V·O2 attained compared with other pacing strategies, and b) regardless of pacing strategy the V·O2 attained in an 800-m pace run on a treadmill is less than V·O2max