The Effect of Circadian Rhythm on Cortisol and Perceived Stress Correlations

Stress is a known trigger of the Hypothalamus-Pituitary-Adrenal (HPA) Axis which leads to the production and secretion of the catabolic steroid cortisol by the adrenal gland. Since cortisol production is affected by stress, it follows that a high self-perception of stress would be correlated with high blood and saliva cortisol levels. Literature generally shows a gap in identifying this correlation, perhaps because of the interconnected nature of endocrine pathways. New experimental methods that control for the effects of circadian rhythm have shown limited success in demonstrating this correlation. Our purpose is to continue exploring the relationship between cortisol, perceived stress, and circadian rhythm. This will be done by comparing the results of the Trier Inventory for Chronic Stress (TICS) survey, to the cortisol concentration in saliva samples taken during the cortisol awakening response (CAR). When these results are analyzed, based on individual chronotype (whether someone is a morning or evening person based on the Lark or Owl Questionnaire), we hypothesize that a stronger, positive correlation between perceived stress and cortisol concentration change will be exhibited. When the salivary cortisol concentration changes, during the CAR, were compared to participant perceived stress and chronotype, no statistical significance was determined. Despite conflicting correlative trends, based on comparing results from different time points during the CAR, this research has shown evidence towards a negative correlation between perceived stress and CAR reactivity, and parallel correlative trends between perceived stress and chronotype

An Accountability Architecture for the Internet

In the current Internet, senders are not accountable for the packets they send. As a result, malicious users send unwanted traffic that wastes shared resources and degrades network performance. Stopping such attacks requires identifying the responsible principal and filtering any unwanted traffic it sends. However, senders can obscure their identity: a packet identifies its sender only by the source address, but the Internet Protocol does not enforce that this address be correct. Additionally, affected destinations have no way to prevent the sender from continuing to cause harm. An accountable network binds sender identities to packets they send for the purpose of holding senders responsible for their traffic. In this dissertation, I present an accountable network-level architecture that strongly binds senders to packets and gives receivers control over who can send traffic to them. Holding senders accountable for their actions would prevent many of the attacks that disrupt the Internet today. Previous work in attack prevention proposes methods of binding packets to senders, giving receivers control over who sends what to them, or both. However, they all require trusted elements on the forwarding path, to either assist in identifying the sender or to filter unwanted packets. These elements are often not under the control of the receiver and may become corrupt. This dissertation shows that the Internet architecture can be extended to allow receivers to block traffic from unwanted senders, even in the presence of malicious devices in the forwarding path. This dissertation validates this thesis with three contributions. The first contribution is DNA, a network architecture that strongly binds packets to their sender, allowing routers to reject unaccountable traffic and recipients to block traffic from unwanted senders. Unlike prior work, which trusts on-path devices to behave correctly, the only trusted component in DNA is an identity certification authority. All other entities may misbehave and are either blocked or evicted from the network. The second contribution is NeighborhoodWatch, a secure, distributed, scalable object store that is capable of withstanding misbehavior by its constituent nodes. DNA uses NeighborhoodWatch to store receiver-specific requests block individual senders. The third contribution is VanGuard, an accountable capability architecture. Capabilities are small, receiver-generated tokens that grant the sender permission to send traffic to receiver. Existing capability architectures are not accountable, assume a protected channel for obtaining capabilities, and allow on-path devices to steal capabilities. VanGuard builds a capability architecture on top of DNA, preventing capability theft and protecting the capability request channel by allowing receivers to block senders that flood the channel. Once a sender obtains capabilities, it no longer needs to sign traffic, thus allowing greater efficiency than DNA alone. The DNA architecture demonstrates that it is possible to create an accountable network architecture in which none of the devices on the forwarding path must be trusted. DNA holds senders responsible for their traffic by allowing receivers to block senders; to store this blocking state, DNA relies on the NeighborhoodWatch DHT. VanGuard extends DNA and reduces its overhead by incorporating capabilities, which gives destinations further control over the traffic that sources send to them

Management of Oral Cavity Mucormycosis in a Ketoacidotic Patient with Targeted Debridement and a Palate Obturator

Mucormycosis is an opportunistic mycosis common in poorly-controlled insulin dependent diabetic patients particularly with ketoacidosis. It often begins as a nasal and paranasal sinus infection with inhalation of spores into the paranasal sinuses of a susceptible host. In this case report we review the clinical symptoms, relevant imaging, and management of a diabetic patient with mucormycosis threatening his better seeing eye. This case report offers the clinician a review of important clinical and diagnostic findings that can help direct the need for orbital exenteration. In addition, various reconstruction options are considered to help guide informed management

Extent of craniofacial fungal osteomyelitis in a ketoacidotic patient may predict optic nerve involvement: A case report

Introduction: Mucormycosis is an opportunistic mycosis common in poorly-controlled insulin dependent diabetic patients particularly with ketoacidosis. Fungal osteomyelitis is a life-threatening condition affectation of the nose and paranasal sinuses within the orofacial region. Presentation of case: We present a 63-year-old diabetic male patient with maxillary mucormycotic osteomyelitis threatening his better seeing eye and review the clinical symptoms, relevant imaging, and management. Discussion: We highlight a rare pattern of craniofacial fungal bone infection with maxillary and orbital involvement that ultimately spared the optic nerve. This case report offers the clinician a review of important clinical and diagnostic findings that can help direct the need for orbital exenteration. Conclusion: Maxillary mucormycotic osteomyelitis is an aggressive infection that needs to be addressed promptly to prevent fatal consequences

Standardized loads acting in knee implants

The loads acting in knee joints must be known for improving joint replacement, surgical procedures, physiotherapy, biomechanical computer simulations, and to advise patients with osteoarthritis or fractures about what activities to avoid. Such data would also allow verification of test standards for knee implants. This work analyzes data from 8 subjects with instrumented knee implants, which allowed measuring the contact forces and moments acting in the joint. The implants were powered inductively and the loads transmitted at radio frequency. The time courses of forces and moments during walking, stair climbing, and 6 more activities were averaged for subjects with I) average body weight and average load levels and II) high body weight and high load levels. During all investigated activities except jogging, the high force levels reached 3,372–4,218N. During slow jogging, they were up to 5,165N. The peak torque around the implant stem during walking was 10.5 Nm, which was higher than during all other activities including jogging. The transverse forces and the moments varied greatly between the subjects, especially during non-cyclic activities. The high load levels measured were mostly above those defined in the wear test ISO 14243. The loads defined in the ISO test standard should be adapted to the levels reported here. The new data will allow realistic investigations and improvements of joint replacement, surgical procedures for tendon repair, treatment of fractures, and others. Computer models of the load conditions in the lower extremities will become more realistic if the new data is used as a gold standard. However, due to the extreme individual variations of some load components, even the reported average load profiles can most likely not explain every failure of an implant or a surgical procedure

Improving Exposure for Transoral Oropharyngeal Surgery with the Floor of Mouth Window: A Cadaveric Feasibility Study

Background: Transoral robotic and laser surgery is rising in popularity due to the increasing incidence of Human Papilloma Virus (HPV) related oropharyngeal cancer. However, adequate exposure of the tongue base remains a major hurdle in many cases. This study introduces a novel surgical technique called the Floor of Mouth Window, which can be used to improve tongue base exposure at the time of transoral surgery. Methods: This is a preclinical anatomic cadaver study. Seven fresh cadavers were used for this study. Exposure of the tongue base was compared between conventional mouth gags – the Feyh-Kastenbauer and McIvor – and our novel procedure, the Floor of Mouth Window. Exposure was compared subjectively using endoscopic and extracorporeal photographs, as well as objective measurements of inter-incisor distance, and oral cavity volume. Results: The exposure achieved by the Floor of Mouth Window technique was superior to the mouth gags. Inter-incisor distance and oral cavity volume measurements were all more favorable with the Floor of Mouth Window. This technique allowed for successful transoral laser tongue base and tonsil resection without the use of gags or scopes. Conclusion: The Floor of Mouth Window is an adjunctive procedure that simply and reliably improved exposure for transoral oropharyngeal surgery in this cadaveric feasibility study. This improved exposure may help increase the adoption of transoral surgery and reduce the number of aborted cases due to anatomic limitations

Eustachian Tube Foreign Body with Endoscopic-Assisted Surgical Removal

Abstract Objectives. Foreign bodies of the external and middle ear are not uncommon; however, foreign bodies in the eustachian tube are rare. Here we describe the presentation, imaging, and endoscopic-assisted surgical management of a case of eustachian tube foreign body. Methods. A 34-year-old male was seen for evaluation of foreign body of the left eustachian tube while working with metal at a machine shop. Imaging and surgical management are highlighted and review of available literature regarding foreign bodies of the eustachian tube is presented. Results. A CT scan revealed a foreign body present approximately 1 cm into the bony eustachian tube. The patient underwent middle ear exploration which required endoscopic assistance to adequately visualize the foreign body. The foreign body was unable to be removed and required the creation of a bony tunnel lateral to the eustachian tube for visualization and access to the foreign body. Conclusions. This report presents a rare case of eustachian tube foreign body. Use of the endoscope during the surgical removal greatly enhanced the ease and safety of removal. This report also highlights the importance of ear protection with any machining and welding work

Engaging Students in the Basic Course By Asking Big Questions

This paper advocates for the inclusion of big questions into the basic course curriculum. It begins by exploring the nature of big questions as those that engage pressing and perennial civic and global issues, and details their effectiveness in encouraging students and faculty to think about interpersonal responsibility and social space as dynamically interfacing and mutually reflexive, thus challenging us to negotiate the civic call of engaging in democratic processes. The basic course, whether public speaking or hybrid, offers a crucial opportunity for big questions to emerge because it brings people together to critically question and produce messages about the social and civic contexts in which we all engage as students, faculty, employees, family, and citizens. Thus, the article includes examples from several basic course instructors and administrators of how big questions can be incorporated into the curriculum to enhance the learning outcomes of students, while at the same time situating the basic course as more deeply embedded into the stated mission and requirements of our departments, colleges, and general education programs

Tracheocutaneous Sinus following Tracheocutaneous Fistula Repair: Management Strategies in a Pediatric Patient

Objective. To present a rare case of a pediatric tracheocutaneous sinus years after repair of a tracheocutaneous fistula and to review management strategies. Background. A tracheocutaneous fistula is a common sequela of pediatric tracheostomy and can occur in as many as one in three pediatric patients. There is debate in the literature regarding optimal surgical management. Case Presentation. An 8-year-old girl presented to the emergency department with swelling and erythema over the anterior neck. Clinical exam and diagnostic imaging revealed an underlying tracheocutaneous sinus. Discussion. Complications following pediatric tracheostomy are common and range in complexity from stomal granulation to tracheocutaneous fistula. There is some debate regarding the optimal surgical management of children with tracheocutaneous fistula following tracheostomy. This report discusses the management of a pediatric child with an unusual tracheocutaneous sinus and reviews the various surgical techniques which have been described for definitive repair

Lawrence Head Volcanics and Dunnage Mélange, Newfoundland Appalachians: Origin by Ordovician Ridge Subduction or in Back-Arc Rift?

This paper reviews the geological setting and reports new geochemical trace element data from the Ordovician Lawrence Head Volcanics (LHV) and the underlying gabbro sills in the Exploits Group. In combination with existing published analyses and ages of these rocks, the volcanic rocks and sills are indistinguishable in composition and age, and the data are consistent with the hypothesis that they represent the same (mostly E-MORB composition) magmatic event in the early–mid Darriwilian (~465 ± 2 Ma). The LHV and their enclosing strata show regional evidence for: 1) upward decline of volume and grain size of arc-derived volcaniclastic materials over the uppermost interval of turbidite sedimentary strata below the LHV; 2) change to shallow marine conditions locally by the end of the LHV event, followed immediately by significant subsidence, and 3) no evidence of coarse-grained clastic input, nor of normal faulting, during or immediately after LHV magmatism. Ridge–trench interaction (ridge subduction) at a subduction system is consistent with all of these features and spatial distribution of related elements, but a rift (back-arc) origin over a subduction zone can only accommodate the compositions, and is inconsistent with the geological evidence. The Dunnage Mélange (DM) has been interpreted either as olistostromal in a developing back-arc rift basin, or as a subduction accretionary prism. Peraluminous intrusions in the mélange (Coaker Porphyry ― CP) are more readily explained by ridge subduction, and a previously reported zircon age (469 ± 4 Ma) is consistent with the age of the LHV and gabbro sills, also interpreted as products of ridge subduction. Localization of the CP in the eastern area of DM, and of most of the large LHV-derived volcanic blocks in the western DM, suggests a slightly younger age, and perhaps a different mechanism, for the origin of the western DM.SOMMAIRECet article passe en revue le contexte géologique et présente de nouvelles données géochimiques d’éléments traces des roches volcaniques ordoviciennes de Lawrence Head (LHV) et des filons-couches de gabbro sous-jacents du Groupe Exploits.  Considérant la combinaison des données d’analyse publiées et des datations de ces roches, les roches volcaniques et les filons-couches sont indiscernables tant en composition qu’en âge, et les données sont compatibles avec l’hypothèse selon laquelle ils représentent le même événement magmatique (principalement E-MORB) du Darriwilien précoce à moyen (~465 ± 2 Ma).  Les LHV ainsi que les strates de l’encaissant renferment des indices régionaux qui montrent : 1) que le volume et la granulométrie des matériaux volcanoclastiques d’arc diminuent vers le haut dans l’intervalle supérieur des strates de turbidites sédimentaires sous les LHV; 2) que le changement vers des milieux marins peu profonds localement vers la fin de l’événement des LHV a été suivi immédiatement par une subsidence importante, et 3) qu’il n’existe pas d’indices d’apports clastiques à gros grains, non plus que de formation de failles normales, durant ou immédiatement après le magmatisme des LHV.  L’interaction crête-fosse (subduction de la crête) au lieu d’un système de subduction concorde avec toutes ces caractéristiques et la répartition spatiale des éléments reliés, alors qu’une origine de crête (arrière-arc) au-dessus d’une zone de subduction ne peut expliquer que les compositions et qu’elle est incompatible avec l’évidence géologique.  Le Dunnage Mélange (DM) a été interprété soit comme un olistostome dans un bassin d’arrière-arc en développement, ou comme un prisme d’accrétion de subduction.  Les intrusions hyperalumineuses dans le mélange (Porphyre Coaker — CP), s’explique plus facilement par une subduction de crête, et un âge de datation sur zircon de (469 ± 4 Ma) correspond à l’âge des LHV et des filons-couche de gabbro, aussi interprétés comme produits d’une subduction de crête.  La localisation du CP dans la portion orientale du DM, et de la majeure partie des grands blocs volcaniques dérivés des LHV de la portion ouest du DM, suggère un âge légèrement plus jeune, et peut-être un mécanisme différent, pour l’origine de la portion ouest du DM