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While most early limbed vertebrates possessed a fully-roofed dermatocranium in their temporal skull region, temporal fenestrae and excavations evolved independently at least twice in the earliest amniotes, with several different variations in shape and position of the openings. Yet, the specific drivers behind this evolution have been only barely understood. It has been mostly explained by adaptations of the feeding apparatus as a response to new functional demands in the terrestrial realm, including a rearrangement of the jaw musculature as well as changes in strain distribution. Temporal fenestrae have been retained in most extant amniotes but have also been lost again, notably in turtles. However, even turtles do not represent an optimal analog for the condition in the ancestral amniote, highlighting the necessity to examine Paleozoic fossil material. Here, we describe in detail the sutures in the dermatocranium of the Permian reptileCaptorhinus aguti(Amniota, Captorhinidae) to illustrate bone integrity in an early non-fenestrated amniote skull. We reconstruct the jaw adductor musculature and discuss its relation to intracranial articulations and bone flexibility within the temporal region. Lastly, we examine whether the reconstructed cranial mechanics inC. aguticould be treated as a model for the ancestor of fenestrated amniotes. We show thatC. agutilikely exhibited a reduced loading in the areas at the intersection of jugal, squamosal, and postorbital, as well as at the contact between parietal and postorbital. We argue that these “weak” areas are prone for the development of temporal openings and may be treated as the possible precursors for infratemporal and supratemporal fenestrae in early amniotes. These findings provide a good basis for future studies on other non-fenestrated taxa close to the amniote base, for example diadectomorphs or other non-diapsid reptiles. 

Abstract Lipid oxidation by reactive oxygen species (ROS) provide several different oxidation products that have been implicated in inflammatory responses. Ground state atomic oxygen [O(³P)] is produced by the photodeoxygenation of certain heterocyclic oxides and has a reactivity that is unique from other ROS. Due to the reactive nature of O(³P), the site of O(³P)‐generation is expected to influence the products in heterogenous solutions or environments. In this work, the oxidation of low‐density lipoprotein (LDL) by lipids with covalently bound O(³P)‐photoprecursors was compared to more hydrophilic O(³P)‐photoprecursors. Lipid oxidation products were quantified after Bligh‐Dyer extraction and pentafluorobenzyl bromide (PFB) derivatization by GC–MS. Unlike the more hydrophilic O(³P)‐photoprecursors, the oxidation of LDL during the irradiation of lipid‐(O³P)‐photoprecursor conjugates showed little quenching by the addition of the O(³P)‐scavenging sodium allyl sulfonate. This indicated that lipophilic O(³P)‐photoprecursors are expected to generate lipid oxidation products where other more hydrophilic O(³P)‐photoprecursors could be quenched by other reactive groups present in solution or the environment. 

Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) is a federal program designed to promote postsecondary readiness and success among low-income students. Some evidence suggests that this program promotes college enrollment and persistence, but GEAR UP may include a wide variety of services, and it is unclear which ones actually contribute to these apparent overall effects. The present study investigates this issue using doubly robust propensity score analyses to provide stronger causal conclusions. Four general service types and seven specific services were examined; the results provide important implications for GEAR UP and other programs designed to promote postsecondary attainment. 

A beneficial property of photogenerated reactive oxygen species (ROS) is the capability of oxidant generation within a specific location or organelle inside a cell. Dibenzothiophene S -oxide ( DBTO ), which is known to undergo a photodeoxygenation reaction to generate ground state atomic oxygen [O( 3 P)] upon irradiation, was functionalized to afford localization within the plasma membrane of cells. The photochemistry, as it relates to oxidant generation, was studied and demonstrated that the functionalized DBTO derivatives generated O( 3 P). Irradiation of these lipophilic O( 3 P)-precursors in the presence of LDL and within RAW 264.7 cells afforded several oxidized lipid products (oxLP) in the form of aldehydes. The generation of a 2-hexadecenal ( 2-HDEA ) was markedly increased in irradiations where O( 3 P) was putatively produced. The substantial generation of 2-HDEA is not known to accompany the production of other ROS. These cellular irradiation experiments demonstrate the potential of inducing oxidation with O( 3 P) in cells.