bluuebunny/crossref_metadata_2025_split huggingface dataset:
What Can Frogs Teach Us about Resilience? Adaptive Renewal in Amphibian and Academic Ecosystems
Authors: Byrne Allison Q 
Published: May 2024

Synopsis
Examples of resilience in nature give us hope amid a growing biodiversity crisis. While resilience has many definitions across disciplines, here I discuss resilience as the ability to continue to adapt and persist. Naturally, as biologists, we seek to uncover the underlying mechanisms that can help us explain the secrets of resilience across scales, from individuals to species to ecosystems and beyond. Perhaps we also ponder what the secrets to resilience are in our own lives, in our own research practices, and academic communities. In this paper, I highlight insights gained through studies of amphibian resilience following a global disease outbreak to uncover shared patterns and processes linked to resilience across amphibian communities. I also reflect on how classical resilience heuristics could be more broadly applied to these processes and to our own academic communities. Focusing on the amphibian systems that I have worked in—the Golden Frogs of Panama (Atelopus zeteki/varius) and the Mountain Yellow-Legged Frogs of California (Rana muscosa/sierrae)—I highlight shared and unique characteristics of resilience across scales and systems and discuss how these relate to adaptive renewal cycles. Reflecting on this work and previous resilience scholarship, I also offer my own thoughts about academia and consider what lessons we could take from mapping our own adaptive trajectories and addressing threats to our own community resilience.
On the singularity point in acoustic orthorhombic media
Authors: Stovas Alexey 
Published: May 2024

Abstract
The acoustic orthorhombic model is widely used in seismic modeling and processing of P-wave data. However, the anisotropic acoustic models have so called S-wave artifacts (1 artifact in transversely isotropic acoustic medium and two artifacts in orthorhombic acoustic medium). I show that S-wave artifacts can have one singularity point that results in complications in polarization field and the group velocity surface. The conditions of the existence of this point are defined in terms of anellipticity parameters. This singularity point and its group velocity image are the objects of my analysis.
Neck Anatomy
Authors: Pan Wenyu , Malik Tariq M. 
Published: May 2024

Abstract
The anatomy of the neck is essential for anesthesia practice, including airway management, central venous catheter cannulation through the internal jugular vein, nerve blocks for regional anesthesia, and cervical sympathetic block for pain syndromes. The anatomy of the neck is divided into the anterior and posterior neck triangles by the sternocleidomasoid muscle. The anterior triangle contains airway structures, thyroid, and major vessels of the neck, while the posterior triangle contains most nerves of interest that are blocked for postoperative analgesia of shoulder and arm. This chapter reviews the major landmarks of the neck and important learning points related to its anatomy. Airway innervation, implications of nerve injury, and anatomy of the cricothyroid membrane are reviewed. Major vascular structures of the neck, bony landmarks, and application in central venous access and nerve blocks are delineated.
Principles of Ultrasound
Authors: Young Emily , Zaky Sherif 
Published: May 2024

Abstract
Ultrasound is a safe and noninvasive tool that uses sound waves to produce a real-time image of organs and tissues. Medical ultrasound uses high frequency waves between 2 000 000–15 000 000 Hz (2–15 MHz). As the ultrasound beam travels through the body, it is attenuated by the tissues via absorption, reflection, and scattering. Reflection of ultrasound waves depends on the difference in the acoustic impedance between two substances. Acoustic impedance of a substance depends on its density and the propagation speed of ultrasound through this substance. When an ultrasound beam reflects at the interface between two materials, it creates an “echo” which can be described as hyperechoic, hypoechoic, or anechoic. Anesthesiologists can compensate for attenuation by adjusting overall gain or gain at certain depth (time gain compensation). Spatial resolution (axial and lateral) refers to the ability to distinguish between two objects in space as separate echoes. Temporal resolution is the ability to distinguish between two events in time. Penetration refers to the ability of ultrasound waves to reach deep structures. The higher the frequency, the more the ultrasound beam is attenuated as it travels, and the less distance it can penetrate.
Principles of Doppler Ultrasound
Authors: Young Emily , Zaky Sherif 
Published: May 2024

Abstract
Doppler ultrasound is a modality that can be used to examine the direction, velocity, and pattern of blood flow in a vessel. This imaging modality uses the principles of the Doppler effect to detect movement within body tissues. It is most often used to examine the direction, speed, and pattern of blood flow in a target vessel or across a valve. Doppler ultrasound works by detecting shifts in frequency that occur when sound waves reflect off a moving surface. If an object is moving toward the ultrasound probe, the reflected frequency of the ultrasound beam is shifted higher. If an object is moving away from the ultrasound probe, the reflected frequency is shifted lower. The transducer detects these positive and negative shifts and uses them to display information about detected blood flow as a waveform or a color image. Continuous wave Doppler emits a continuous sound beam and receives all returning signals. It detects all signals along its path. Pulsed wave Doppler sends out a sound beam in short pulses. An “electronic gate” can be set to evaluate only Doppler signals from a certain target depth. Color flow Doppler assigns a color hue to moving objects based on their direction and speed. The color flow image is superimposed on a traditional gray-scale image, allowing for real-time assessment of blood flow within specific anatomical structures. Power Doppler detects subtle, low-volume flow. It uses the amplitude of the returning Doppler signals to generate an image without providing information about direction of flow.
Vaporizer Types and Safety Features
Authors: Aquino Ben 
Published: May 2024

Abstract
The vaporizer is a key component of any anesthesia machine and any gas-based anesthetic, using oxygen and other carrying gases to deliver vaporized volatile anesthetic gas to the patient via the anesthesia circuit—in a predictable, consistent, easily controlled, and safe way. The vaporizers in use today include the variable-bypass vaporizer, dual-circuit vaporizer, and cassette vaporizer. The variable bypass vaporizers are used for sevoflurane and isoflurane. The high vapor pressure and low boiling point of desflurane make it unusable in a variable bypass vaporizer at normal room temperature. As a result, it is dispensed via its own unique dual-circuit vaporizer, where it is heated in one circuit and then the vaporized gas is added to the carrier gas mixture in the other circuit. Modern-day vaporizers have multiple structural and schematic features that ensure safe delivery of volatile anesthetic to the patient. These safeguard against potential problems, such as overfilling or tipping the vaporizer, filling the vaporizer with the wrong gas, or leaking.
Toxicity of Inhaled Anesthetics
Authors: Drennen Zachary , Cormican Daniel S. 
Published: May 2024

Abstract
Inhalational anesthetics are ubiquitous, reliable agents with which a patient can be placed under general anesthesia. Although rare, there are documented toxicities associated with the use of these agents. Older agents such as methoxyflurane, halothane, and enflurane are no longer used, due in large part to their associated toxicities. Newer agents such as isoflurane, sevoflurane, and desflurane are not without risk of toxicities of their own. Despite being vital to human life, oxygen is also associated with neurological, respiratory, and ocular toxicities through the formation of reactive oxygen species. The toxicities associated with inhaled agents and oxygen are discussed further herein.
Heart Functions
Authors: Noor Nazir , Viswanath Omar 
Published: May 2024

Abstract
The American Society of Anesthesiologists (ASA) has five standard monitors which are intended to provide critical physiologic monitoring for the anesthetized patient. Additional monitoring, whether invasive or noninvasive, depends on the condition of the patient and the procedure they are scheduled to undergo. One of the most important organ systems to monitor is the heart. Three important approaches in monitoring the heart function include the physical exam and auscultation of the heart tones, the electrical activity of the heart via electrocardiography (EKG), and assessing the motion of the heart walls via transesophageal echocardiography (TEE). These three approaches in assessing the heart function of the perioperative patient are the topic of discussion in this chapter.
Mechanical Ventilators
Authors: White Peggy , Giordano Chris 
Published: May 2024

Abstract
Mechanical ventilators have substantially evolved over the last half century to facilitate the management of respiratory decompensation. They have transitioned from operating room and intensive care units to transport and noninvasive options. To appreciate these options, the healthcare provider needs to recognize the forces applied to the pulmonary system and the resulting pulmonary mechanics for the safe delivery of anesthesia. Dynamic and static compliance impacts the efficacy of gases that the ventilator delivers. Ventilator scalars (flow, pressure, or volume as functions of time) provide a graphical understanding of the ventilator-pulmonary interface. By applying the information from scalars, anesthesia professionals can optimize patient-ventilator synchrony.
Drug Absorption and Distribution
Authors: Parker Nicholas M. 
Published: May 2024

Abstract
Two important components of pharmacokinetics are absorption and distribution. Absorption depends on the route of administration and chemical properties of the drug. Intravenous administration bypasses the absorption step completely, while absorption after oral administration requires a complex series of events that many molecules cannot survive. Distribution refers to drugs moving from the bloodstream to tissues throughout the body, and depends on local blood flow, protein binding, and chemical factors like the drug’s partition coefficient. Impairments in absorption or distribution may necessitate a change in dose and/or route to attain the desired effect; such changes are common in the operating room given conditions like fluctuating blood pressure and administration of blood products.
Tolerance and Tachyphylaxis
Authors: Zaky Sherif , Hozian Nicholas 
Published: May 2024

Abstract
Tolerance is defined as the progressive diminished response to a drug at a certain dose following repeated exposure, thus requiring increased dosage on subsequent administrations to achieve the same effect. It is a state of adaptation in which exposure to a certain dose of a drug for a long duration of time leads to diminished drug effects. Tachyphylaxis is a type of tolerance that develops acutely within only a few doses of a drug. Both terms involve biological responses to certain dosages of drugs and include similar cellular mechanisms but differing rates of desensitization. Cellular mechanisms of tolerance and tachyphylaxis involve pharmacokinetic (absorption, distribution, metabolism, and elimination) and pharmacodynamic (receptor adaptive changes, recruitment of opposing mechanisms, and downregulation) changes. Management of such conditions can be difficult and can involve increasing dosage and frequency, drug rotation, and gradual weaning of the drug of concern to allow for restored pharmacological response to the drug in the future.
Hepatic Blood Flow
Authors: Jones Courtney R. 
Published: May 2024

Abstract
The liver receives nearly a quarter of the cardiac output every minute and serves as a large reservoir of blood. It is unique in that it has a dual supply of oxygenated blood from the portal vein and the hepatic artery. The interaction between the two sources of blood supply is complex, and the two work together to maintain nearly constant hepatic blood flow; the hepatic arterial buffer response is one of the specialized mechanisms that allow for regulation in hepatic arterial flow in response to the portal venous flow. Anesthesiologists should also be aware that the hepatic blood flow is affected by general anesthesia, neuraxial anesthesia, inhalational anesthetics, and intravenous anesthetics. The physiology of hepatic blood flow is often manipulated during liver transplantation to modulate portal venous flow and improve the graft outcome.
Propofol
Authors: Ferguson Kris , Papapetrou Peter 
Published: May 2024

Abstract
Propofol is one of the most common intravenous anesthetic agents. It rapidly crosses the blood-brain barrier for quick onset of action at the GABA A receptor. Termination of action is through liver metabolism and diffusion. Propofol is a short acting medication that can induce and maintain general anesthesia. Sedation is dose dependent, and effects can range from sedation with varying levels of amnesia to general anesthesia. Propofol decreases postoperative nausea and vomiting. Propofol has been shown to be safe in children as an induction dose. Long-term, continuous infusion of propofol can cause propofol infusion syndrome, which involves metabolic acidosis, rhabdomyolysis, heart failure, and kidney failure. This combination of metabolic deragements can be fatal if not appropriately treated.
Calcium Channel Blockers
Authors: Sprowell Andrew , Sharma Archit 
Published: May 2024

Abstract
Calcium plays an important part in various bodily processes, such as blood coagulation, esophageal tone, enzyme systems, muscle contraction, bone metabolism, synaptic transmission, myocardial contractility, and conduction, as well as vascular smooth muscle reactivity. Due to these effects, this group has found widespread application in treatment of arrhythmias, angina, pulmonary hypertension, achalasia, and esophageal spasm. Hence, it can be anticipated that any drug interfering with the action of calcium could have widespread effects. This chapter emphasizes the effects that calcium channel blockers have and the anesthetic implications of managing a patient that is using these medications.
Guidelines for Perioperative Cardiovascular Evaluation
Authors: Hanna Rewais B. , Abd-Elsayed Alaa 
Published: May 2024

Abstract
In 2014, the American College of Cardiology/American Heart Association Task Force introduced guidelines for perioperative cardiovascular evaluation in an attempt to minimize the risk of major cardiac events during surgery. The preoperative evaluation of a patient should include (1) assessment of perioperative risk, (2) determination of the need for changes in management, and (3) identification of cardiovascular conditions or risk factors requiring longer-term management. Lastly, the objective of preoperative evaluation is to encourage shared decision-making between providers and patients about their cardiovascular risk prior to surgery.
ASA Classification
Authors: Patel Sheetal , Abd-Elsayed Alaa 
Published: May 2024

Abstract
ASA classification is widely used for preoperative risk assessment and prediction of postoperative complications of surgical patients. It is also useful to predict perioperative risks when used with other factors such as type of surgery, functional status of the patient, and frailty. Higher ASA class is associated with a substantial increase in risk. ASA classification is popular among all other available tools to predict risks for the patient for the surgery due to its simplicity and quickly assessment.
Uremia
Authors: Walia Anureet , Sharma Archit 
Published: May 2024

Abstract
Uremia refers to high levels of urea in the blood, which usually occur during renal failure due to the inability of the kidneys to excrete urea in the urine. Renal failure leads to the patient having constitutional symptoms, nausea, tremors, and encephalopathy. Extracellular fluid overload from sodium retention, in association with increased cardiac demand from anemia, leads to these patients being prone to congestive heart failure. Prolonged severe uremia can lead to pericarditis and pleural effusion, as well as uremia-induced platelet dysfunction and malnutrition. Treatment involves providing supportive care, maintaining renal perfusion by fluid resuscitation or vasopressors, avoiding nephrotoxic agents, and eventually hemodialysis, if all other means fail.
Obstructive Sleep Apnea
Authors: Varshney Shivani , Yuan Adam Yu 
Published: May 2024

Abstract
Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder seen in the surgical population. It is an independent risk factor for increased morbidity and mortality during the perioperative period. Patients with OSA present complex challenges to the anesthesiologist with compromised cardiopulmonary reserves, increased sensitivity to anesthetic drugs, and a potentially difficult airway. These patients tend to be obese and often have other associated comorbidities such as hypertension, diabetes, and heart failure. Preoperative recognition of at-risk patients, perioperative utilization of continuous positive airway pressure (CPAP) therapy, and a well-designed anesthetic plan will improve outcomes in patients with OSA.
Hypertension
Authors: Dagher Talia H. , Beck Lauren 
Published: May 2024

Abstract
Hypertension is a prevalent disease that affects all aspects of perioperative care. Hypertension is typically managed with diet, exercise, and antihypertensive medications, including calcium channel blockers, beta blockers, ACE-inhibitors, and diuretics. Preoperative optimization is key, with the goal of normotension prior to surgery; however, this is not always feasible. Intraoperative blood pressure may be labile in this patient population, and appropriate management of both hypertension and hypotension is important to reduce morbidity and mortality. The risk of postoperative hypertension is also increased in this patient population. Intravenous labetalol and hydralazine are the most commonly used antihypertensive agents in the post-anesthesia care unit if this occurs.
Anesthetic Management of Patients with Allergies
Authors: Girma Brook , Kaye Alan D. 
Published: May 2024

Abstract
Adverse drug reactions are an unfortunate occurrence during anesthesia. Prior to surgery the anesthesiologist should gather any clinical or past medical history to assess whether the patient is at risk for a possible drug allergy. The most effective management to prevent an allergic reaction is to avoid the allergen itself. Prophylactic treatments include corticosteroids alone or in combination with an H1 antagonist.
Prophylactic Cardiac Risk Reduction
Authors: Gibson Christina , Cormican Daniel S. 
Published: May 2024

Abstract
This chapter focuses on perioperative cardiac risk assessment and evaluation. The ACC/AHA have published guidelines for perioperative testing and management, including revascularization and medical therapy, focusing on beta-blocking agents, antiplatelet agents, statins, and angiotensin converting enzyme (ACE) inhibitors. If noninvasive test results will not change patient management, then further testing is not warranted. Patients who may benefit from stress testing include those who have at least one risk factor or elevated risk with poor or unknown functional capacity. The ACC/AHA guidelines indicate the role of preoperative revascularization and timing of elective surgery following stent placement, based on the type of stent and the antiplatelet therapy utilized. Evidence suggests that patients who undergo revascularization prior to surgery show no benefit over those who are medically optimized. Patients with stable coronary artery disease and multiple cardiac risk factors are likely to benefit from beta-blocker therapy. Beta blockers should be initiated several weeks prior to surgery and titrated to appropriate heart rate and blood pressure levels to minimize adverse effects in the perioperative period. Patients on chronic beta-blocker therapy should continue their medication perioperatively. Perioperative statin therapy should also be continued and is recommended for all vascular surgery patients. ACE inhibitors are associated with perioperative hypotension; however, no increased risk of adverse cardiovascular events has been shown. Antiplatelet agents result in increased risk of bleeding. Therefore, the risk of bleeding versus thrombosis needs to be weighed in the context of the surgical procedure and discussed with each patient.
Airway Devices
Authors: Schmitt Ben , Jani Jai 
Published: May 2024

Abstract
This chapter explores commonly used devices for placement of endotracheal tubes, including direct laryngoscopy techniques, fiberoptic devices, video laryngoscopy, and transillumination. The focus is on how the device works, and unique aspects of each technique. Direct laryngoscopy relies upon creating a line of sight from mouth to larynx to visualize insertion of an endotracheal tube. Video and fiberoptic technologies rely on indirect visualization (either through viewing lens or video screen) and do not require alignment of oral, pharyngeal, and laryngeal axis. Transillumination relies upon the anterior positioning of the trachea, and ability to see a bright light emitted from inside the trachea as a red glow on the patient’s neck.
Types of Endotracheal Tubes
Authors: Jindal Aparna , Sharma Archit 
Published: May 2024

Abstract
Endotracheal tubes serve the function of securing the airway and acting as a conduit between the ventilator and the patient to assist with gas exchange. Different types of tubes are used in different situations, based on their properties, patient size, and the type of surgery being performed. These are commonly used devices that are critical for patient safety, so it is important to understand their design and use. Modifications were made to the initial design to accomplish tasks, such as minimizing aspiration, isolating a lung, providing a clear facial surgical field during general anesthesia, monitoring laryngeal nerve damage during surgery, preventing airway fires during laser surgery, and administering medications. This chapter discusses the various kinds of endotracheal tubes and their clinical applications.
Colloids
Authors: Watt Stacey , D’Auria Anthony 
Published: May 2024

Abstract
The textbook Basic Anesthesia Review examines the anesthesiologist’s role in intravenous fluid administration as an integral component of an anesthesiologist’s responsibilities and surveys the efficacy, benefits, and potential deleterious effects on the use of the colloid solutions: albumin, hetastach, and pentastarch. This chapter reviews the differences between crystalloid and colloid solutions in terms of intravascular volume expansion, colloid reactions, the effects of albumin on sodium concentration, and the effects of hydroxyethyl starches (HESs) on coagulation, and renal dysfunction. It also reviews intravascular and extravascular volume and a brief description of the glycocalyx layer. This chapter is targeted for anesthesiology residents in preparation for Basic Exam Review.