bluuebunny/crossref_metadata_2025_split huggingface dataset:
Late Classic Maya Water Management and Community Organization at Copan, Honduras
Authors: Davis-Salazar Karla L. 
Published: February 2007

AbstractRecent research on prehispanic water management throughout the Americas has made significant contributions to our understanding of the diversity of adaptive systems employed in regions where water is seasonally scarce, such as the Maya Lowlands. Since much of this workfocuses on large-scale technologies, the political and economic consequences of these systems for smaller social units remain poorly understood. Social dynamics associated with less-intensive forms of water use and control are investigated at Late Classic (A.D. 600–900) Copán, in a water-rich setting of western Honduras. Ethnographic, iconographic, and archaeological datasets suggest that lagoons located in Copán’s urban residential sectors may have been conceptualized, utilized, and maintained as communal property with ancestral ties by the inhabitants of surrounding domestic groups. By shifting the scale of analysis from the polity to the community level, these lagoons can be viewed as forms of communal property that created an economic and ideological basis for local social integration but offered limited opportunity for the centralization of power through monopolistic control. Yet, toward the end of the Late Classic, the appropriation of water-related dynastic symbolism and possibly ritual seems to have provided nonroyal elites with a means for creating local social identities, which undercut and eroded royal authority.
First Report of a Newly Discovered Paleoindian Quarry Site on the Isthmus of Panama
Authors: Pearson Georges A. 
Published: February 2007

AbstractAn archaeological survey on the Azuero Peninsula in Panama has recently discovered a Paleoindian quarry/workshop at the base of a quartz outcrop. The Nieto site contains seldom-seen preforms and flake blanks that provide new information on early-stage reduction strategies used by Clovis-like point makers in the Neotropics. Finished tools recovered at the site include gravers, side scrapers, and large scraper planes. The production of flake blanks followed a core reduction and rejuvenation strategy already observed at other Paleoindian sites in Costa Rica and Florida. Although the quartz outcrop is located only a few kilometers away from better-quality sources of jasper and chert, Paleoindians appear to have preferred this translucent stone for their weaponry. This new information, when combined with late-stage production strategies previously recorded from other Panamanian sites, brings us closer to tracing a complete manufacturing trajectory for Clovislike points on the Isthmus. It is hoped that data from the Nieto quarry/workshop will eventually help archaeologists determine if the presence of the fluting technique in Central and South America is attributable to a migration of Clovis-related people or a technological diffusion among pre-established southerly populations.
Sak Tz’i’, a Classic Maya Center: A Locational Model Based on GIS and Epigraphy
Authors: Hernández Armando Anaya , Guenter Stanley P. , Zender Marc U. 
Published: February 2007

AbstractThe ancient Maya hieroglyphic inscriptions of the upper Usumacinta region record an intensive interaction that took place among its regional capitals. The precise geographic locations of some of these sites are presently unknown. Through the application of the Gravity Model within the framework of Geographic Information Systems (GIS), we present the probable locations and possible territorial extents of a few of these: Sak Tz’i’, Hix-Witz, and the “Knot-Site.” On this occasion, however, we concentrate our discussion on the role that the kingdom of Sak Tz’i’ played in the geopolitical scenario of the region. It is our belief that this case study constitutes a good example of how, through a conjunctive approach that integrates the archaeological with the epigraphic data, GIS can represent an excellent analytical tool to approach archaeological issues such as the political organization of the Maya Lowlands during the Late Classic period.
Geologic Water Storage in Precolumbian Peru
Authors: Fairley Jerry P. 
Published: February 2007

AbstractAgriculture in the arid and semi-arid regions that comprise much of present-day Peru, Bolivia, and Northern Chile is heavily dependent on irrigation; however, obtaining a dependable water supply in these areas is often difficult. The precolumbian peoples of Andean South America adapted to this situation by devising many strategies for transporting, storing, and retrieving water to insure consistent supply. I propose that the “elaborated springs” found at several Inka sites near Cuzco, Peru, are the visible expression of a simple and effective system of groundwater control and storage. I call this system “geologic water storage” because the water is stored in the pore spaces of sands, soils, and other near-surface geologic materials. I present two examples of sites in the Cuzco area that use this technology (Tambomachay and Tipón) and discuss the potential for identification of similar systems developed by other ancient Latin American cultures.
Can We Read Cosmology in Ancient Maya City Plans? Comment on Ashmore and Sabloff
Authors: Smith Michael E. 
Published: February 2007

AbstractArguments for the cosmological significance of ancient Maya city layouts are plausible, but empirical applications are subjective and lack rigor. I illustrate this contention through brief comments on a recent article by Ashmore and Sabloff. I first discuss some of the complexities and pitfalls in studying cosmology from ancient city plans, and then focus on one component of the authors’ cosmological model—the hypothesized north-south axis at Classic Maya cities. My goal is not to down-play or rule out the role of cosmology in Maya city planning, but rather to encourage the use of explicit assumptions and rigorous methods that will provide the study of Maya city planning with a more secure empirical foundation.
Immunohistochemical evaluation of cyclooxygenase expression in corneal squamous cell carcinoma in horses
Authors: McInnis Carey L. , Giuliano Elizabeth A. , Johnson Philip J. , Turk James R. 
Published: February 2007

Abstract
Objective—To evaluate expression of cyclooxygenase (COX)-1 and COX-2 in the cornea, eyelid, and third eyelid of healthy horses and those affected with squamous cell carcinoma (SCC) by use of immunohistochemical techniques.
Animals—15 horses with SCC involving ocular tissues and 5 unaffected control horses.
Procedures—SCC-affected tissues were obtained from the cornea (n = 5 horses), eyelid (5), and third eyelid (5). Site-matched control tissues were obtained from 5 horses unaffected with SCC. Tissue sections of affected and control cornea, eyelid, and third eyelid were stained immunohistochemically for COX-1 and COX-2 via standard techniques. Stain uptake was quantified by use of computer-assisted image analysis of digital photomicrographs.
Results—Immunoreactivity for both COX-1 and COX-2 was significantly greater in equine corneas with SCC than in control corneas. No significant differences in COX-1 or COX-2 immunoreactivity were detected in eyelid and third-eyelid SCC, compared with site-matched control tissues.
Conclusions and Clinical Relevance—Immunoreactivity for COX-1 and COX-2 is high in equine corneal SCC, possibly indicating that COX plays a role in oncogenesis or progression of this tumor type at this site. Pharmacologic inhibition of COX may represent a useful adjunctive treatment for corneal SCC in horses.
Treatment of traumatic cervical myelopathy with surgery, prolonged positive-pressure ventilation, and physical therapy in a dog
Authors: Smarick Sean D. , Rylander Helena , Burkitt Jamie M. , Scott Nancy E. , Woelz Jacqueline S. , Jandrey Karl E. , Aldrich Janet , Sturges Beverly K. 
Published: February 2007

Abstract
Case Description—A 9-year-old dog was evaluated for traumatic cervical myelopathy after a surgical attempt to realign and stabilize the C2 and C3 vertebrae.
Clinical Findings—The dog could not ventilate spontaneously and was tetraplegic; positive-pressure ventilation (PPV) was maintained. Myelography and computed tomography revealed spinal cord compression with subluxation of the C2 and C3 vertebrae and extrusion of the C2-3 intervertebral disk.
Treatment and Outcome—Surgically, the protruding disk material was removed and the vertebrae were realigned with screws and wire. For PPV, assist control ventilation in volume control mode and then in pressure control mode was used in the first 6 days; this was followed by synchronized intermittent mandatory ventilation until 33 days after the injury; then only continuous positive airway pressure was provided until the dog could breathe unassisted, 37 days after the injury. Physical therapy that included passive range of motion exercises, neuromuscular electrical stimulation, and functional weight-bearing positions was administered until the dog was discharged 46 days after injury; the dog was severely ataxic and tetraparetic but could walk. Therapy was continued at home, and 1 year later, the dog could run and had moderate ataxia and tetraparesis.
Clinical Relevance—Hypoventilation with tetraparesis in traumatic spinal cord injury can be successfully treated with PPV exceeding 30 days, surgery, and physical therapy.
Ultrasound-assisted collection of cerebrospinal fluid from the lumbosacral space in equids
Authors: Aleman Monica , Borchers Angela , Kass Philip H. , Puchalski Sarah M. 
Published: February 2007

Abstract
Objective—To describe ultrasonographic landmarks for use in collection of CSF from the lumbosacral region in equids.
Design—Prospective study.
Animals—37 equids (27 with neurologic disease and 10 with nonneurologic disease).
Procedures—Standing equids (n = 17) were sedated with detomidine hydrochloride (0.006 to 0.01 mg/kg [0.003 to 0.005 mg/lb], IV) followed by butorphanol tartrate (0.01 mg/kg, IV) and restrained with a nose twitch for collection of CSF. The CSF was collected from 20 laterally recumbent equids (10 sedated and 10 immediately after euthanasia). Anatomic landmarks were identified ultrasonographically. Height at the dorsal point of the shoulders, body weight, depth of the spinal needle, number of attempts to collect CSF, and cytologic evaluation of CSF were recorded.
Results—Lumbosacral puncture cranial to the cranial border of the most superficial location of both tuber sacrale along the midline was consistently successful for CSF collection (35/37 equids). Two horses had anatomic abnormalities that precluded CSF collection. Mean number of attempts to collect CSF per animal was 1.1. Height and body weight were strongly correlated with needle depth for CSF collection. Pelvic and sacral displacement was observed in several laterally recumbent animals, which resulted in discrepancies of the midline between the cranial and caudal aspects of the vertebral column. In most equids, the spinal needle was aligned on the midline of the caudal aspect of the vertebral column.
Conclusions and Clinical Relevance—Ultrasonography was a useful aid for collection of CSF from the lumbosacral space and decreased the risk of repeated trauma and contamination in equids.
Transition to Weight-Based High-Flow Nasal Cannula Use Outside of the ICU for Bronchiolitis
Authors: Willer Robert J. , Brady Patrick W. , Tyler Amy N. , Treasure Jennifer D. , Coon Eric R. 
Published: March 2024

ImportanceMost children’s hospitals have adopted weight-based high-flow nasal cannula (HFNC) bronchiolitis protocols for use outside of the intensive care unit (ICU) setting. Whether these protocols are achieving their goal of reducing bronchiolitis-related ICU admissions remains unknown.ObjectiveTo measure the association between hospital transition to weight-based non-ICU HFNC use and subsequent ICU admission.Design, Setting, and ParticipantsThis multicenter retrospective cohort study was conducted with a controlled interrupted time series approach and involved 18 children’s hospitals that contribute data to the Pediatric Health Information Systems database. The cohort included patients aged 0 to 24 months who were hospitalized with a diagnosis of bronchiolitis between January 1, 2010, and December 31, 2021. Data were analyzed from July 2023 to January 2024.ExposureHospital-level transition from ICU-only to weight-based non-ICU protocol for HFNC use. Data for the ICU-only group were obtained from a previously published survey.Main Outcomes and MeasuresProportion of patients with bronchiolitis admitted to the ICU.ResultsA total of 86 046 patients with bronchiolitis received care from 10 hospitals in the ICU-only group (n = 47 336; 27 850 males [58.8%]; mean [SD] age, 7.6 [6.2] years) and 8 hospitals in the weight-based protocol group (n = 38 710; 22 845 males [59.0%]; mean [SD] age, 7.7 [6.3] years). Mean age and sex were similar for patients between the 2 groups. Hospitals in the ICU-only group vs the weight-based protocol group had higher proportions of Black (26.2% vs 19.8%) and non-Hispanic (81.6% vs 63.8%) patients and patients with governmental insurance (68.1% vs 65.9%). Hospital transition to a weight-based HFNC protocol was associated with a 6.1% (95% CI, 8.7%-3.4%) decrease per year in ICU admission and a 1.5% (95% CI, 2.8%-0.1%) reduction per year in noninvasive positive pressure ventilation use compared with the ICU-only group. No differences in mean length of stay or the proportion of patients who received invasive mechanical ventilation were found between groups.Conclusions and RelevanceResults of this cohort study of hospitalized patients with bronchiolitis suggest that transition from ICU-only to weight-based non-ICU HFNC protocols is associated with reduced ICU admission rates.
Toward One‐Way Smoke: Synthesis of Copper‐Based Microclubs with Asymmetric Scattering and Absorption
Authors: Guo Shichen , Boyarsky Michael , Vigil S. Avery , Yu Yifan , Moreno‐Hernandez Ivan A. , Gehm Michael E. , Wiley Benjamin J. 
Published: March 2024

AbstractThe ultimate goal of this work is to create an engineered aerosol that acts as one‐way smoke, i.e. it creates an asymmetric vision environment in which the ability to image objects depends on the viewing direction. To this end, a rapid, one‐pot synthesis of copper‐based microclubs is developed that consists of a Cu2O octahedron attached to a Cu2O@Cu shaft. Millions of synthesized particles are analyzed in minutes with a FlowCam to provide a robust statistical analysis of their geometry, and rapidly elucidate the roles of the reaction constituents on the particle shape and yield. The combination of asymmetry in both shape and composition introduces a 30% difference in scattering of light propagating parallel to the microclub axis from opposing directions. This work represents a first step toward the creation of an asymmetric imaging environment with an aerosol consisting of acoustically aligned microclubs.
Recent Design Strategies for M‐N‐C Single‐Atom Catalysts in Oxygen Reduction: An Entropy Increase Perspective
Authors: Yan Wei , Chen Wenmiao , Chen Yanli 
Published: March 2024

AbstractRecently, a diverse array of novel metal‐nitrogen‐carbon (M‐N‐C) single‐atom catalysts (SACs) have rapidly evolve, particularly in the realm of oxygen reduction reaction (ORR). Despite the plethora of proposed design and improvement strategies for SACs, a comprehensive review systematically compiling the components in M‐N‐C from a unified perspective is notably absent. For the first time, a thorough examination of each component in M‐N‐C is conducted, focusing on the perspective of entropy increase in the active sites of SACs. For the single M‐N4 sites and the whole M‐N‐C system, an increase in entropy implies an elevated degree of disorder and chaos. Broadly, the entropy‐increasing modification of M (single mental sites) and guest groups entails an augmentation of chaos, with the most effective co‐catalytic synergy achieved by establishing multiple active sites through a “cocktail effect”. Concerning N (nitrogen and other heteroatoms) and C (carbon supports), the entropy increase modification induces heightened disorder, with symmetry breaking more likely to drive M‐N4 toward adsorbing oxygen molecules to attain an equilibrium symmetric structure. All these innovative design strategies have led to a remarkable improvement in the ORR activity and stability and offer a guiding criterion for the future preparation of SACs.
Precursor Symmetry Triggered Modulation of Fluorescence Quantum Yield in Graphene Quantum Dots
Authors: Chen Liangfeng , Yang Siwei , Li Yongqiang , Liu Zheng , Wang Hang , Zhang Yuqing , Qi Kai , Wang Gang , He Peng , Ding Guqiao 
Published: March 2024

AbstractAlthough various effective machine‐learning attempts have been made to investigate the photoluminescence properties of graphene quantum dots (GQDs) or carbon dots, the physical correlation behind their mathematical models has not been reasonably elucidated. In this work, the correlation mechanism between the precursor structure and quantum yield of GQDs prepared by a “bottom‐up” method is sufficiently studied. Three decisive factors affecting the quantum yield of GQDs during the two‐component reaction system preparation are revealed, namely structure factor (F1), temperature factor (F2), and concentration factor (F3). The symmetry of precursors in the formation of sp2–sp3 hybrid carbon nanostructures is considered the key factor in the modulation of fluorescence quantum yield in GQDs. Notably, in contrast to previous work, it is first demonstrated that the normal modes of molecular vibration are the core mechanism by which the structural properties of the precursors act on the fluorescence quantum yield of GQDs. The conclusion further proved conducive in obtaining GQDs with a higher absolute quantum yield up to 83.33%.
Centimeter‐Size Single Crystal of a Polar Dion–Jacobson Double Perovskite with Large Mobility‐Lifetime Product toward Effective X‐Ray Detection
Authors: Guo Wuqian , Xu Haojie , Fan Qingshun , Zhu Pengfei , Ma Yu , Liu Yi , Zeng Xi , Luo Junhua , Sun Zhihua 
Published: March 2024

AbstractDion–Jacobson (DJ) double perovskites have emerged as environmentally friendly candidates for X‐ray detection, owing to their prominent optoelectronic performance and highlighted structural rigidity. Despite considerable efforts, the exploration of polar DJ‐type double perovskites for self‐powered X‐ray detection remains scarce. Herein, by introducing a diamine spacer to increase the structural rigidity, the study has successfully designed a new polar 2D DJ‐type double perovskite of (HIA)2AgBiBr8 (1, HIA = histamine), and centimeter‐size crystals are successfully obtained for effective X‐ray detection. Structurally, 1 features the quantum‐confined motif comprised of the directionally arranged inorganic perovskite sheets and alternating organic spacing cations, which endows a large mobility‐lifetime (µτ) product up to 1.23 × 10−3 cm2 V−1 on the par with typical X‐ray sensing candidates (MAPbI3 wafers, µτ = 2 × 10−3 cm2 V−1). This attribute gives rise to a high sensitivity of 118 µCGyair−1 cm−2 to X‐ray illumination. Moreover, based on its polar structure, bulk photovoltaic effect with the photovoltage of ≈0.45 V is obtained in 1, which affords the driving source toward the self‐powered X‐ray photodetection. This work highlights the potential of DJ‐type double perovskites in high‐energy ray detection and opens avenues for exploring new functionalities of DJ double perovskites as smart photoelectric candidates.
Ni active sites isolated by antimony toward enhanced propyne semi‐hydrogenation
Authors: Xi Jiahang , Yan Kelin , Zhu Ningchao , Ge Xiaohu , Yuwen Qiang , Chen Mingming , Jiang Hao , Cao Yueqiang , Zhou Xinggui , Duan Xuezhi 
Published: March 2024

AbstractRegulating Ni active sites toward the formation of target product is of great importance for designing high‐performance cost‐effective catalysts for catalytic semi‐hydrogenations but remains challenging. Herein, we report the fabrication of NiSb intermetallic catalyst via structural transformation from a layered double hydroxides precursor for boosting propyne semi‐hydrogenation. Systematic characterizations, including x‐ray diffraction, atomic‐resolution electron microscopy, and x‐ray absorption spectroscopy, provide evidence for the formation of P63/mmc NiSb intermetallic phase in the synthesized NiSb catalyst. The host Ni active sites are demonstrated to be isolated by the high‐electronegativity p‐block guest Sb sites, which deliver remarkably high selectivity to target propene, that is, up to propene selectivity of 96% at nearly full propyne conversion. Temperature‐programmed surface reaction and temperature‐programmed desorption measurements combined with theoretical calculations unravel that the excellent selectivity originates from kinetically more favorable desorption of propene than its hydrogenation to propane on the regulated Ni active sites.
Exploring Pyroelectricity, Thermal and Photochemical Switching in a Hybrid Organic‐Inorganic Crystal by In Situ X‐Ray Diffraction
Authors: Morris Joshua J. , Bowen Chris R. , Coulson Ben A. , Eaton Mark , Raithby Paul R. , Saunders Lucy K. , Skelton Jonathan M. , Wang Qingping , Warren Mark R. , Zhang Yan , Hatcher Lauren E. 
Published: March 2024

AbstractThe switching behavior of the novel hybrid material (FA)Na[Fe(CN)5(NO)].H2O (1) in response to temperature (T), light irradiation and electric field (E) is studied using in situ X‐ray diffraction (XRD). Crystals of 1 display piezoelectricity, pyroelectricity, second and third harmonic generation. XRD shows that the FA+ are disordered at room‐temperature, but stepwise cooling from 273–100 K induces gradual ordering, while cooling under an applied field (E=+40 kVcm−1) induces a sudden phase change at 140 K. Structural‐dynamics calculations suggest the field pushes the system into a region of the structural potential‐energy surface that is otherwise inaccessible, demonstrating that application of T and E offers an effective route to manipulating the crystal chemistry of these materials. Photocrystallography also reveals photoinduced linkage isomerism, which coexists with but is not correlated to other switching behaviors. These experiments highlight a new approach to in situ studies of hybrid materials, providing insight into the structure–property relationships that underpin their functionality.
Radicalizing CO by Mononuclear Palladium(I)
Authors: Bruckhoff Tim , Ballmann Joachim , Gade Lutz H. 
Published: March 2024

AbstractA mononuclear, T‐shaped palladium(I) d9 metalloradical (3), stabilized by a bulky carbazole‐based PNP‐ligand, was obtained by reduction of palladium chloride or thermal Pd−C bond homolysis of the corresponding neopentyl complex. Pressurizing with CO gave the Pd(I) carbonyl complex, which was structurally characterized by X‐ray diffraction. Delocalization of the unpaired electron to the carbonyl carbon was detected by EPR spectroscopy and theoretically modeled by DFT and ab initio methods. The partially reduced and radicalized CO slowly reacts with di(tert‐butyl) disulfide under homolytic S−S cleavage and C−S bond formation to give the corresponding metallathioester.