Perioperative fluid administration to optimise haemodynamics without fluid overload in anaesthetised dogs : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Manawatu, New Zealand

Perioperative fluid therapy is the mainstay of anaesthetic management. Fluid administration improves haemodynamics during anaesthesia as it increases preload and thus cardiac output and blood pressure. However, excessive fluid administration can cause detrimental adverse effects, such as haemodulution and oedema, resulting in prolonged hospital stay and increased morbidity and mortality in people. Therefore, fluid administration should be restricted to those who are able to increase stroke volume or cardiac output in response to the fluid administration (responders) and should not be given to those who are unable to do so (non-responders) based on the famous “Frank–Starling law of the heart” Previously static parameters such as central venous pressure were believed to be a clinical gold standard to estimate preload and fluid responsiveness. Over the last decade, dynamic parameters such as pulse pressure variation and pleth variability index have been shown to be reliable predictors for fluid responsiveness in people. This study found that pulse pressure variation and pleth variability index were more accurate than central venous pressure for predicting fluid responsiveness in dogs. Mini-fluid challenge is another technique that is currently available and can be reliably used to determine fluid responsiveness in human medicine. Mini-fluid challenge is an administration of a small amount of fluid to increase preload. Thus, fluid responsiveness can be assessed based on whether stroke volume increases following mini-fluid challenge according to the Frank-Starling curve. The change in stroke volume of a heart at the steep portion of the Frank-Starling curve will be greater than at the plateau portion after mini-fluid challenge. The studies revealed a percentage change in pulse wave transit time (a surrogate parameter of stroke volume, which was also one of results in this thesis) following mini-fluid challenge could predict fluid responsiveness in mechanically ventilated anaesthetised dogs under an experimental condition, and spontaneously breathing anaesthetised dogs undergoing stifle surgery in clinical setting. Lastly, these methods are still of limited use in veterinary clinical practice because of availability of equipment, difficulty of their interpretation and a cumbersome process. The main purpose of this thesis was to obtain evidence on how to optimise haemodynamics in anaesthetised dogs and prevent excessive fluid administration. The time when most practitioners administer a bolus of fluid during anaesthesia is when hypotension is encountered because of anaesthesia. Thus, prevention of hypotension could avoid excessive fluid administration. Therefore, the study found that prophylactic noradrenaline administration, which counteracts some of the cardiovascular adverse effects of anaesthesia, was able to prevent hypotension, and thus minimise fluid administration in anaesthetised dogs. Although all of these methods tested in this thesis have pros and cons in clinical veterinary practice, they were shown to be able to optimise haemodynamics without fluid overload in anaesthetised dogs

Possibility of cryopreservation of medaka eggs using liquid meniscus

The First Pacific Rim Thermal Engineering Conference (PRTEC2016), Marchi 13-17, 2016, Waikoloa Beach Marriott Resort & Spa Hawaii's Big Island, USAThe cryopreservation of fish eggs is an important subject in the field of fishery and preservation of biological species. Thus far, there has been no success in the preservation of fish eggs because of the large size of the eggs and the thick external shell. This paper discusses the effectiveness of using the liquid meniscus formed around the egg for protecting its morphology. Freezing and thawing experiments of medaka eggs were performed under different freezing conditions, and the hatching rate of the egg was examined. Before freezing, the eggs were dehydrated at room temperature in order to reduce the effect of volume expansion caused by freezing. It was confirmed that 100% of the eggs dehydrated by 15% or less were successfully hatched. In the freezing process, a medaka egg was placed on a hydrophobic cooling plate and a thin liquid meniscus was formed around the hydrophilic egg surface. An aqueous solution of trehalose was used as the liquid meniscus as well as a cryoprotectant to prevent damage caused by freezing. Cryopreservation of the egg was not successfully performed for all processes, including intracellular freezing; however, 80% of the eggs were alive even after freezing of the external meniscus. Therefore, it is confirmed that the liquid meniscus is effective for the cryopreservation of the external shell. The liquid meniscus can reduce the physical stress due to extracellular ice growth. Moreover, since the liquid meniscus system has a low heat capacity, the thermal process is easy to control compared to the conventional method. We concluded that the present method can be used for the cryopreservation of fish eggs

Quantitative Measurement and Analysis to Computational Thinking for Elementary Schools in Japan

In Japan, programming education has been made compulsory in elementary schools since 2020. The Programming Education Guide (GPE) explains the purpose of programming education and the abilities that can be fostered through programming education. In addition, the “Portal Site for Programming Education Focusing on Elementary Schools” introduces various examples of programming education. However, there is little information measuring whether programming classes are effective in improving OTWP (Objective Thinking as a Way of Programming) abilities based on CT (Computational Thinking), except for reports of improvement after simple statistical analysis. Therefore, we prepared 30 CT questions, 12 basic and 18 applied, for the CT test considering four key techniques, decomposition, pattern recognition, abstraction, and algorithms, of which 14 questions were pre-test and seven questions were assessment test. In the experiment, 18 elementary school students from grades 1st to 6th were given a short workshop only once, and the analysis of the effect was done statistically, considering their habituation to the problems. The results of the experiment showed that there was no effect of the one-time workshop, unlike other reports of improvement that used simple statistical methods. It became clear that the CT ability was not improved by the short education. On the other hand, a new finding is that females may be inferior to males in three techniques: decomposition, algorithm, and abstraction

Multiple Retinal Vascular Occlusion after Vitrectomy

Retinal vascular occlusion after ocular surgery is a rare but serious complication. A history of cardiovascular diseases, retrobulbar anesthesia injection, high intraocular pressure during the perioperative period, and drug toxicity have been reported as possible causative factors. We report here two cases of multiple retinal vascular occlusions after the subconjunctival injection of gentamicin at the end of uncomplicated 25-gauge vitrectomy. Case 1 was a 61-year-old man who developed a macular hole in the right eye. Phacovitrectomy with gas tamponade was performed. On postoperative day (POD) 1, dot hemorrhage was observed on the temporal side of the optic disk. On POD10, macular whitening, retinal hemorrhage, and multiple occlusion of retinal arteries and veins were observed. Case 2 was a 51-year-old woman who was diagnosed with rhegmatogenous retinal detachment in the right eye and underwent phacovitrectomy with gas tamponade. On POD3, macular whitening with cotton wool spots and retinal hemorrhage were observed with macular ischemia owing to occlusion of retinal arteries and veins. In both cases, subconjunctival injection of gentamicin given at the end of surgery was the most suspected cause of retinal vascular occlusion

A Highly Sensitive Strain Sensor Using Surface Acoustic Wave and Its Evaluation for Wireless Battery-less Sensor Network

Proceedings of The 6th IEEE Conference on Sensors (SENSORS2007

Security Impact Analysis of Degree of Field Extension in Lattice Attacks on Ring-LWE Problem

Modern information communications use cryptography to keep the contents of communications confidential. RSA (Rivest-Shamir-Adleman) cryptography and elliptic curve cryptography, which are public-key cryptosystems, are widely used cryptographic schemes. However, it is known that these cryptographic schemes can be deciphered in a very short time by Shor's algorithm when a quantum computer is put into practical use. Therefore, several methods have been proposed for quantum computer-resistant cryptosystems that cannot be cracked even by a quantum computer. A simple implementation of LWE-based lattice cryptography based on the LWE (Learning With Errors) problem requires a key length of $O(n^2)$ to ensure the same level of security as existing public-key cryptography schemes such as RSA and elliptic curve cryptography. In this paper, we attacked the Ring-LWE (RLWE) scheme, which can be implemented with a short key length, with a modified LLL (Lenstra-Lenstra-Lov\'asz) basis reduction algorithm and investigated the trend in the degree of field extension required to generate a secure and small key. Results showed that the lattice-based cryptography may be strengthened by employing Cullen or Mersenne prime numbers as the degree of field extension.Comment: accepted in COMPSAC 2023 Workshop DSML: The 1st IEEE International Workshop on Data Science & Machine Learning for Cybersecurity, IoT & Digital Forensic