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Introduction: The uniqueness of the atlas (C1) and axis (C2) cervical vertebrae helps in transmitting weight from the cranial cavity to the rest of the vertebral column. A detailed understanding of the C1 and C2 morphometric dimensions is essential for evaluating treatment protocols such as screw placement and intralaminar fixations to provide stability for the occipitocervical complex. Computerised Tomography (CT) scan images are best for demonstrating the osseous margins. Aim: To assess the relationship between the linear morphometric measurements of the CT images and dry C1 and C2 vertebrae. Materials and Methods: A descriptive, cross-sectional study was conducted using 35 atlas (C1) and 35 axis (C2) dry bones from the Department of Anatomy, Karuna Institute of Medical Sciences, Palakkad, Kerala, India, from August 2023 to October 2023. A total of 35 CT scan images were also taken for the study. Siemens Syngo software tool was utilised to assess the C1 and C2 vertebrae. Measurements of the vertebral canal, foramen transversarium, superior articular facets, vertebral artery groove, dens, and body were performed on dry C1, C2, and CT images. Descriptive statistics were evaluated using mean, standard deviation, percentage difference, and mean deviation. The unpaired t-test was used to test significance, with p-value

Introduction: The uniqueness of the atlas (C1) and axis (C2) cervical vertebrae helps in transmitting weight from the cranial cavity to the rest of the vertebral column. A detailed understanding of the C1 and C2 morphometric dimensions is essential for evaluating treatment protocols such as screw placement and intralaminar fixations to provide stability for the occipitocervical complex. Computerised Tomography (CT) scan images are best for demonstrating the osseous margins. Aim: To assess the relationship between the linear morphometric measurements of the CT images and dry C1 and C2 vertebrae. Materials and Methods: A descriptive, cross-sectional study was conducted using 35 atlas (C1) and 35 axis (C2) dry bones from the Department of Anatomy, Karuna Institute of Medical Sciences, Palakkad, Kerala, India, from August 2023 to October 2023. A total of 35 CT scan images were also taken for the study. Siemens Syngo software tool was utilised to assess the C1 and C2 vertebrae. Measurements of the vertebral canal, foramen transversarium, superior articular facets, vertebral artery groove, dens, and body were performed on dry C1, C2, and CT images. Descriptive statistics were evaluated using mean, standard deviation, percentage difference, and mean deviation. The unpaired t-test was used to test significance, with p-value <0.05 considered statistically significant. Results: Concerning the anatomical parameters, between the dry C1 and CT scan images, all linear parameters were statistically significant (p-value <0.05), except for the vertebral artery grooveinner and outer distances, which were not statistically significant. Regarding C2, when comparing anatomical parameters between dry vertebrae and CT scan images, the width of the body and the length of the vertebral canal were not statistically significant, while all other C2 parameters were statistically significant (p-value <0.05). Conclusion: The results obtained from the study on the atlas and axis may be valuable for operating surgeons during surgical procedures in the craniovertebral region. The present study also aids in preventing iatrogenic complications, including vertebral neurovascular injuries, and provides a roadmap for skilled surgical access. [ABSTRACT FROM AUTHOR]

Introduction: Chiari 1 malformation and hind brain hernia can be associated with skull base and craniocervical anomalies. One of the more recently associated anomalies is a retroverted or retroflexed odontoid process or dens. We conducted a retrospective study of our operated symptomatic and conservatively managed asymptomatic Chiari cohort to assess the impact of dens retroflexion on rate of revision or cerebrospinal fluid diversion following primary foramen magnum decompression (FMD). Methods: We undertook a retrospective study of all foramen magnum decompression (FMD) cases for Chiari type 1 malformation performed over a 15-year period in a single tertiary paediatric neurosurgical unit. For comparison, non-operated asymptomatic Chiari cases were considered as reference cohort. Information gathered included: demographics, age, sex, length of cerebellar tonsils below McRae's line, pB-C2 distance (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C2 body), angle of retroflexion (angle formed between a line drawn through the odontoid synchondrosis and its intersection with a line drawn from the tip of the odontoid process) and angle of retroversion (angle formed between the line drawn from the base of C2 and its intersection with a line drawn from the tip of the odontoid process). Grade of retroflexion was measured using pre-operative mid-sagittal MR images and classified as grade 0 (> 90°), grade 1 (85°–89°); grade 2 (80°–84°) and grade 3 (< 80°). The rates for redo surgery or need for cerebrospinal fluid (CSF) diversion were obtained from clinical records and compared in the operated and non-operated groups. Results: One hundred twenty-six Chiari 1 patients were included in this study with adequate imaging. Sixty-five patients were in the non-operated asymptomatic cohort with 61 patients in the operated symptomatic cohort. Mean age of non-operated cohort was 10.2 years with M:F ratio (30:35). Mean cerebellar tonsillar length below McRae's line was 10.3 mm. 7.7% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 76 and 78°, respectively. Retroflexion grades included (9.2% grade 1, 35% grade 2 and 52.3% grade 3). pB-C2 distance was 6.8 mm. Mean age of operated cohort was 11.3 years, with M:F ratio (21:40). Mean cerebellar tonsillar length below McRae's line was 15 mm. 45.9% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 73 and 74.5°, respectively. Retroflexion grades included (4.9% grade 1, 16.5% grade 2 and 78.6% grade 3). pB-C2 distance was 6.9 mm. No association was identified between retroflexion grade and rate of revision or CSF diversion following primary foramen magnum decompression. Conclusion: The operated Chiari 1 cohort had more retroflexed dens, longer tonsils and associated syrinx compared to the non-operated asymptomatic cohort. [ABSTRACT FROM AUTHOR]

Introduction: Atlas fractures often accompany traumatic dens fractures, but existing literature on the management of simultaneous atlantoaxial fractures is limited. Methods: We examined all patients with traumatic dens fractures at our institution between 2008 and 2018. We used multivariable logistic regression and ordinal logistic regression to identify factors independently associated with presentation with a simultaneous atlas fracture, as well myelopathy severity, fracture nonunion, and selection for surgery. Results: Two hundred and eighty-two patients with traumatic dens fractures without subaxial fractures were identified, including 65 (22.8%) with simultaneous atlas fractures. The distribution of injury mechanisms differed between groups (χ2 P = 0.0360). On multivariable logistic regression, dens nonunion was positively associated with type II fractures (odds ratio [OR] = 2.00, P = 0.038) and negatively associated with having surgery (OR = 0.52, P = 0.049), but not with having a C1 fracture (P = 0.3673). Worse myelopathy severity on presentation was associated with having a severe injury severity score (OR = 102.3, P < 0.001) and older age (OR = 1.28, P = 0.002), but not with having an atlas fracture (P = 0.2446). Having a simultaneous atlas fracture was associated with older age (OR = 1.29, P = 0.024) and dens fracture angulation (OR = 2.62, P = 0.004). Among patients who underwent surgery, C1/C2 posterior fusion was the most common procedure, and having a simultaneous atlas fracture was associated with selection for occipitocervical fusion (OCF) (OR = 14.35, P = 0.010). Conclusions: Among patients with traumatic dens, patients who have simultaneous atlas fractures are a distinct subpopulation with respect to age, mechanism of injury, fracture morphology, and management. Traumatic dens fractures with simultaneous atlas fractures are independently associated with selection for OCF rather than posterior cervical fusion alone.

The red fox (Vulpes vulpes) is the second largest mammalian predator in Prince Edward Island (PEI), Canada. Finding suitable sites for denning has a direct effect on the success of this species in urban habitats. However, information is lacking regarding the ecology of these animals, including the location of their dens and factors that may influence densite selection in small urban areas. This information can be valuable for wildlife management. The goal of this study is to better understand the patterns of den-site selection of the red fox in urban areas. Through field surveys and community science data collection over 2 yrs, 124 red fox dens were observed in Charlottetown, PEI. A resource selection function design was used to explore habitat use versus availability and identify factors that may influence den-site selection within the urban matrix, including land use, distance to roads and distance to commercial and residential buildings. Logistic regression analyses identified environmental attributes that best predicted the occurrence of den sites, compared to available den-site locations. Akaike Information Criterion model selection techniques were used to determine best fit of the observed data. The best multiple regression model fitting the data showed that there is a higher probability of foxes selecting den sites within 20 m of natural areas and/or urban green spaces. The odds of finding fox dens also increased by 35% when moving away from roads, and by 56% when moving away from buildings. Overall, our findings suggest that although foxes appear to use all land use types existing in the Charlottetown region for denning, the ideal sites for dens include some natural habitats, low levels of human disturbance, and roads and buildings ~50 m away. Such sites may provide several advantages during the breeding season, including access to both natural and anthropogenic food items, less human disturbance including noise, vehicles and domestic animals. As a prominent, well-adapted carnivore coexisting in cities with humans and domestic animals, the red fox can act as a vector for disease and parasites. Thus, understanding den-site selection in urban environments may be a valuable tool in wildlife management to reduce conflicts with humans including the transmission risk of serious zoonotic diseases. [ABSTRACT FROM AUTHOR]

Introduction: Atlas fractures often accompany traumatic dens fractures, but existing literature on the management of simultaneous atlantoaxial fractures is limited. Methods: We examined all patients with traumatic dens fractures at our institution between 2008 and 2018. We used multivariable logistic regression and ordinal logistic regression to identify factors independently associated with presentation with a simultaneous atlas fracture, as well myelopathy severity, fracture nonunion, and selection for surgery. Results: Two hundred and eighty-two patients with traumatic dens fractures without subaxial fractures were identified, including 65 (22.8%) with simultaneous atlas fractures. The distribution of injury mechanisms differed between groups (χ2 P = 0.0360). On multivariable logistic regression, dens nonunion was positively associated with type II fractures (odds ratio [OR] = 2.00, P = 0.038) and negatively associated with having surgery (OR = 0.52, P = 0.049), but not with having a C1 fracture (P = 0.3673). Worse myelopathy severity on presentation was associated with having a severe injury severity score (OR = 102.3, P < 0.001) and older age (OR = 1.28, P = 0.002), but not with having an atlas fracture (P = 0.2446). Having a simultaneous atlas fracture was associated with older age (OR = 1.29, P = 0.024) and dens fracture angulation (OR = 2.62, P = 0.004). Among patients who underwent surgery, C1/C2 posterior fusion was the most common procedure, and having a simultaneous atlas fracture was associated with selection for occipitocervical fusion (OCF) (OR = 14.35, P = 0.010). Conclusions: Among patients with traumatic dens, patients who have simultaneous atlas fractures are a distinct subpopulation with respect to age, mechanism of injury, fracture morphology, and management. Traumatic dens fractures with simultaneous atlas fractures are independently associated with selection for OCF rather than posterior cervical fusion alone. [ABSTRACT FROM AUTHOR]

Endangered San Joaquin kit foxes (Vulpes macrotis mutica; SJKF) and California ground squirrels (Otospermophilus beecheyi; CAGS) occur sympatrically in many locations. CAGS can constitute a nuisance species and control strategies have included lethal measures administered within CAGS burrows. These measures could harm or kill a SJKF if mistakenly applied to an occupied SJKF den. To identify attributes to distinguish between SJKF dens and CAGS burrow, we assessed dimensions, penetration depths by 9.7-cm and 7.5-cm spheres, ejecta patterns, and the presence of various types of sign at 65 dens to which radiocollared SJKF were tracked and at 80 burrows that CAGS were observed to enter. Mean entrance height, width, and circumference all were significantly larger for SJKF den entrances. However, the ranges of values for all dimensions for the CAGS burrows completely encompassed the ranges for the SJKF dens. Penetration depths with the 7.5-cm sphere were similar for SJKF dens and CAGS burrows. The 9.7-cm sphere could not be inserted in over half of CAGS burrows and exceeded 1 m in depth in over half of the SJKF dens. Most SJKF dens had dirt berms but so did over half of the CAGS burrows. SJKF scats, prey remains, CAGS scats, and trash were observed at both SJKF dens and CAGS burrows although at different frequencies. CAGS tracks were only observed at seven CAGS burrows. None of the attributes we assessed provided unequivocal criteria for distinguishing between SJKF dens and CAGS burrows. Also, SJKF occasionally usurp CAGS burrows and CAGS occasionally move into vacant SJKF dens. Therefore, administering lethal control measures within burrows should be avoided as it presents too great a risk to SJKF as well as the many other species that also use CAGS burrows.

Dens fractures are an increasingly common injury, yet their epidemiology and its implications remain underexamined. We retrospectively analyzed all traumatic dens fracture patients managed at our institution over a 10-year period, examining demographic, clinical, and outcomes data. Patient subsets were compared across these parameters. Among 303 traumatic dens fracture patients, we observed a bimodal age distribution with a strong goodness of fit centered at age 22.3 ± 5.7 (R = 0.8781) and at 77.7 ± 13.9 (R = 0.9686). A population pyramid demonstrated a bimodal distribution among male patients, but not female patients, which was confirmed with a strong goodness of fit for male patient subpopulations age <35 (R = 0.9791) and age ≥35 (R = 0.8843), but a weaker fit for a second female subpopulation age <35. Both age groups were equally likely to undergo surgery. Patients younger than age 35 were more likely to be male (82.4% vs. 46.9%, odds ratio [OR] = 5.29 [1.54, 17.57], P = 0.0052), have motor vehicle collision as their mechanism of injury (64.7% vs. 14.1%, OR = 11.18 [3.77, 31.77], P < 0.0001), and to have a severe trauma injury severity score (17.6% vs. 2.9%, OR = 7.23 [1.88, 28.88], P = 0.0198). Nevertheless, patients age <35 were less likely to have fracture nonunion at follow (18.2% vs. 53.7%, OR = 0.19 [0.041, 0.76], P = 0.0288). The dens fracture patient population comprises 2 subpopulations, distinguished by differences in age, sex, injury mechanism and severity, and outcome, with male dens fracture patients demonstrating a bimodal age distribution. Young, male patients were more likely to have high-energy injury mechanisms leading to severe trauma, yet were less likely to have fracture nonunion at follow-up. [ABSTRACT FROM AUTHOR]

Background: Patients with simultaneous fractures of the atlas and dens have traditionally been managed according to the dens fracture's morphology, but data supporting this practice are limited. Methods: We retrospectively examined all patients with traumatic atlas fractures at our institution between 2008 and 2016. We used multivariable regression and propensity score matching to compare the presentation, management, and outcomes of patients with isolated atlas fractures to patients with simultaneous atlas-dens fractures. Results: Ninety-nine patients were identified. Patients with isolated atlas fractures were younger (61 ± 22 vs. 77 ± 14, P = 0.0003), had lower median Charlson Comorbidity Index (3 vs. 5, P = 0.0005), had better presenting Nurick myelopathy scores (0 vs. 3, P < 0.0001), and had different mechanisms of injury (P = 0.0011). Multivariable regression showed that having a simultaneous atlas-dens fracture was independently associated with older age (odds ratio [OR] =1.59 [1.22, 2.07], P = 0.001), worse presenting myelopathy (OR = 3.10 [2.04, 4.16], P < 0.001), and selection for surgery (OR = 4.91 [1.10, 21.97], P = 0.037). Propensity score matching yielded balanced populations (Rubin's B = 23.3, Rubin's R = 1.96) and showed that the risk of atlas fracture nonunion was no different among isolated atlas fractures compared to simultaneous atlas-dens fractures (P = 0.304). Age was the only variable independently associated with atlas fracture nonunion (OR = 2.39 [1.15, 5.00], P = 0.020), having a simultaneous atlas-dens fracture was not significant (P = 0.2829). Conclusions: Among patients with atlas fractures, simultaneous fractures of the dens occur in older patients and confer an increased risk of myelopathy and requiring surgical stabilization. Controlling for confounders, the risk of atlas fracture nonunion is equivalent for isolated atlas fractures versus simultaneous atlas-dens fractures. [ABSTRACT FROM AUTHOR]

In the Genoa river valley (west-central province of Chubut, Argentina), the information on interactions between human groups and animals is scarce. The discovery of Cueva de Plaza archaeological site, where human remains dated 200 years ago, glass beads and the only zooarchaeological assemblage available in the valley were recovered, was a chance to find out if the association between the human and faunal remains responded to funerary offerings or, if as a first evaluation suggested, it was due only to the activity of carnivorous mammals. The results suggest the site functioned as a fox den after the burials and highlight the importance of taphonomic analysis since they provide information on the presence of faunal remains in mortuary contexts and on the intensity of human use of the site. [ABSTRACT FROM AUTHOR]

Background: Patients with simultaneous fractures of the atlas and dens have traditionally been managed according to the dens fracture's morphology, but data supporting this practice are limited. Methods: We retrospectively examined all patients with traumatic atlas fractures at our institution between 2008 and 2016. We used multivariable regression and propensity score matching to compare the presentation, management, and outcomes of patients with isolated atlas fractures to patients with simultaneous atlas-dens fractures. Results: Ninety-nine patients were identified. Patients with isolated atlas fractures were younger (61 ± 22 vs. 77 ± 14, P = 0.0003), had lower median Charlson Comorbidity Index (3 vs. 5, P = 0.0005), had better presenting Nurick myelopathy scores (0 vs. 3, P < 0.0001), and had different mechanisms of injury (P = 0.0011). Multivariable regression showed that having a simultaneous atlas-dens fracture was independently associated with older age (odds ratio [OR] =1.59 [1.22, 2.07], P = 0.001), worse presenting myelopathy (OR = 3.10 [2.04, 4.16], P < 0.001), and selection for surgery (OR = 4.91 [1.10, 21.97], P = 0.037). Propensity score matching yielded balanced populations (Rubin's B = 23.3, Rubin's R = 1.96) and showed that the risk of atlas fracture nonunion was no different among isolated atlas fractures compared to simultaneous atlas-dens fractures (P = 0.304). Age was the only variable independently associated with atlas fracture nonunion (OR = 2.39 [1.15, 5.00], P = 0.020), having a simultaneous atlas-dens fracture was not significant (P = 0.2829). Conclusions: Among patients with atlas fractures, simultaneous fractures of the dens occur in older patients and confer an increased risk of myelopathy and requiring surgical stabilization. Controlling for confounders, the risk of atlas fracture nonunion is equivalent for isolated atlas fractures versus simultaneous atlas-dens fractures.

Emotion recognition using EEG signals is an emerging area of research due to its broad applicability in Brain-Computer Interfaces. Emotional feelings are hard to stimulate in the lab. Emotions don’t last long, yet they need enough context to be perceived and felt. However, most EEG-related emotion databases either suffer from emotionally irrelevant details (due to prolonged duration stimulus) or have minimal context, which may not elicit enough emotion. We tried to overcome this problem by designing an experiment in which participants were free to report their emotional feelings while watching the emotional stimulus. We called these reported emotional feelings “Emotional Events” in our Dataset on Emotion with Naturalistic Stimuli (DENS), which has the recorded EEG signals during the emotional events. To compare our dataset, we classify emotional events on different combinations of Valence(V) and Arousal(A) dimensions and compared the results with benchmark datasets of DEAP and SEED. Short-Time Fourier Transform (STFT) is used for feature extraction and in the classification model consisting of CNN-LSTM hybrid layers. We achieved significantly higher accuracy with our data compared to DEAP and SEED data. We conclude that having precise information about emotional feelings improves the classification accuracy compared to long-duration recorded EEG signals which might be contaminated by mind-wandering. This dataset can be used for detailed analysis of specific experienced emotions and related brain dynamics.

Although wolves are wide‐ranging generalist carnivores throughout their life cycle, during the pup‐rearing season wolf activity is focused on natal den sites where pup survival depends upon pack members provisioning food. Because prey availability is influenced by habitat quality within the home range, we investigated the relative importance of prey species for adults and pups and further examined the relationship between habitat characteristics, wolf diet, and litter size on Prince of Wales Island (POW) in Southeast Alaska. During 2012–2020, we detected 13 active den sites within the home ranges of nine wolf packs. We estimated minimum pup counts using motion‐detecting cameras and individual genotypes from noninvasive samples (hair: n = 322; scat: n = 227) and quantified wolf diet composition using fecal DNA metabarcoding (n = 538). We assessed habitat composition, configuration, and connectivity within denning and annual home ranges estimated using wolf GPS‐collar data. Contrary to expectations, wolves had a more constricted diet during denning season (April 15–July 31), and within this season pups had a narrower dietary niche (species richness [S] = 4) focused more on deer (relative frequency of occurrence [O/I] = 0.924) than adults (S = 15; deer O/I = 0.591). Litter size had a positive relationship with the relative frequency of deer in a wolf pack's diet. Wolf consumption of deer was positively associated with the proportion of young‐growth forest (≤25 years old) within denning and annual home ranges. High levels of vegetation patch interspersion, and the density of closed logging roads were also important predictors, suggesting these habitat qualities were influential for increasing the availability of deer to wolves. Our results contrast with previous research indicating wolf pup diets included more alternate prey (i.e., beaver) than adults and emphasize the importance of deer to wolf viability on POW, especially during denning season. [ABSTRACT FROM AUTHOR]

The establishment of coyote (Canis latrans) populations in urban areas across North America has been accompanied by increased rates of human–coyote conflict. One factor thought to promote physical conflict between coyotes and people or pets is the presence of coyote pups near natal dens; however, this idea has not been tested, and no multivariate study of den selection within cities has occurred. Our objectives were to conduct a multivariate analysis of third‐ (i.e., home range) and fourth‐order (i.e., den sites) habitat selection at dens and determine whether proximity to dens is associated with reports of physical conflict with coyotes. We found 120 dens by following coyote trails using snow tracking within urban green spaces that comprise presumed high‐quality habitat for coyotes in Edmonton, Alberta, Canada. We used resource selection functions to assess habitat selection for dens, testing variables related to land cover and anthropogenic features at the third order, and testing microsite habitat features via paired sites at the fourth order. We defined conflict encounters from comments in a community reporting database and used general linear models to assess their spatial proximity to the nearest den and prevalence during the pup‐rearing period compared to the rest of the year. Habitat selection was strongest at the fourth order, wherein coyotes selected for abundant hiding cover, steep slopes, and eastern exposure. The prevalence of physical conflict with coyotes increased during the pup‐rearing period. Conflict also increased near known dens as an overall effect and when reports occurred outside of naturalized urban areas. These results suggest that coyotes in Edmonton den in green spaces near human development in microsites that minimize detection by people via steep slopes and dense vegetation. We suggest urban wildlife managers increase public safety education about recognition of coyote denning habitat and coyote defensive behaviors, especially outside of naturalized urban areas, because of the observed increase in physical conflict near dens. [ABSTRACT FROM AUTHOR]

Background Context: Prior upper cervical spine injury classification systems have focused on injuries to the craniocervical junction (CCJ), atlas, and dens independently. However, no previous system has classified upper cervical spine injuries using a comprehensive system incorporating all injuries from the occiput to the C2-3 joint.Purpose: To (1) determine the accuracy of experts at correctly classifying upper cervical spine injuries based on the recently proposed AO Spine Upper Cervical Injury Classification System (2) to determine their interobserver reliability and (3) identify the intraobserver reproducibility of the experts.Study Design/setting: International Multi-Center Survey.Patient Sample: A survey of international spine surgeons on 29 unique upper cervical spine injuries.Outcome Measures: Classification accuracy, interobserver reliability, intraobserver reproducibility.Methods: Thirteen international AO Spine Knowledge Forum Trauma members participated in two live webinar-based classifications of 29 upper cervical spine injuries presented in random order, four weeks apart. Percent agreement with the gold-standard and kappa coefficients (ƙ) were calculated to determine the interobserver reliability and intraobserver reproducibility.Results: Raters demonstrated 80.8% and 82.7% accuracy with identification of the injury classification (combined location and type) on the first and second assessment, respectively. Injury classification intraobserver reproducibility was excellent (mean, [range] ƙ=0.82 [0.58-1.00]). Excellent interobserver reliability was found for injury location (ƙ = 0.922 and ƙ=0.912) on both assessments, while injury type was substantial (ƙ=0.689 and 0.699) on both assessments. This correlated to a substantial overall interobserver reliability (ƙ=0.729 and 0.732).Conclusions: Early phase validation demonstrated classification of upper cervical spine injuries using the AO Spine Upper Cervical Injury Classification System to be accurate, reliable, and reproducible. Greater than 80% accuracy was detected for injury classification. The intraobserver reproducibility was excellent, while the interobserver reliability was substantial. [ABSTRACT FROM AUTHOR]

Purpose: To assess the accuracy and reliability of the AO Spine Upper Cervical Injury Classification System based on a surgeons' work setting and trauma center affiliation.Methods: A total of 275 AO Spine members participated in a validation of 25 upper cervical spine injuries, which were evaluated by computed tomography (CT) scans. Each participant was grouped based on their work setting (academic, hospital-employed, or private practice) and their trauma center affiliation (Level I, Level II or III, and Level IV or no trauma center). The classification accuracy was calculated as percent of correct classifications, while interobserver reliability, and intraobserver reproducibility were evaluated based on Fleiss' Kappa coefficient.Results: The overall classification accuracy for surgeons affiliated with a level I trauma center was significantly greater than participants affiliated with a level II/III center or a level IV/no trauma center on assessment one (p1<0.0001) and two (p2 = 0.0003). On both assessments, surgeons affiliated with a level I or a level II/III trauma center were significantly more accurate at identifying IIIB injury types (p1 = 0.0007; p2 = 0.0064). Academic surgeons and hospital employed surgeons were significantly more likely to correctly classify type IIIB injuries on assessment one (p1 = 0.0146) and two (p2 = 0.0015). When evaluating classification reliability, the largest differences between work settings and trauma center affiliations was identified in type IIIB injuries.Conclusion: Type B injuries are the most difficult injury type to correctly classify. They are classified with greater reliability and classification accuracy when evaluated by academic surgeons, hospital-employed surgeons, and surgeons associated with higher-level trauma centers (I or II/III). [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cross-sectional analysis of US national data collected by PearlDiver Inc. database.Objective: To determine the rates of surgical/nonsurgical treatments and associated one-year mortality for displaced type II dens fractures without neurological deficit.Summary Of Background Data: Existing literature on dens fractures includes small series of patients with highly variable surgical rates. These studies contain insufficient data to determine the benefits of surgical or nonsurgical treatment as surgeon bias in treatment and selection of patients have significant effects on the results.Materials and Methods: Displaced type II dens fractures and upper cervical surgeries were identified using their respective International Classification of Diseases, 10th Revision (ICD-10) diagnosis and Current Procedural Terminology (CPT) codes. Inclusion criteria included patients older than 65, diagnosed with a displaced type II dens fracture, absent neurological damage, during the years 2015 to 2018. Age, sex, ICD-10 diagnosis codes, CPT codes, displacement type, and Elixhauser Comorbidity Index scores were obtained through the PearlDiver database. Patient-related variables and one-year mortality associated with surgical versus nonsurgical treatment were compared using univariate χ 2 analysis, odds ratios, and multivariate logistic regression analysis.Results: Among the 5300 patients who met our inclusion criteria, 59% (n=3108) were female, the mean age was 76.6 (±3.9) years old, and the average Elixhauser Comorbidity Index was 7.1 (±4.0). Only 8.3% (n=437) had surgical treatment for the displaced dens fracture. Multivariate logistic regression analysis for one-year mortality showed surgery was associated with decreased one-year mortality in all patients ( z =-6.26; P <0.001), patients between the ages of 65 and 74 ( z =-2.53; P =0.012), and patients over the age of 75 ( z =-5.81; P <0.001).Conclusion: Despite surgery improving survival in elderly patients with type II dens fractures, surgical management is rarely pursued. Factors that independently increase the likelihood of surgery include younger age, male sex, and posterior displacement.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

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Dolichotis patagonum (common name: mara) is a large sized rodent, endemic of Argentina, which raises its juveniles in burrows. It has recently been categorized as vulnerable. This is the first study to evaluate D. patagonum interactions with potential predators in the surroundings of the dens. We monitored 20 burrows, using camera-traps, with a total of 5644 camera-days, obtained over two years (2015 and 2016). Five potential predator species were detected (Lycalopex griseus, Puma concolor, Leopardus geoffroyi, Salvator sp. and Chaetophractus villosus). L. griseus and L. geoffroyi were the species with the highest frequency of visits. Both species were photographed attacking the juveniles. Four out of five potential predator species registered presented agonistic interactions with adults of mara. Overlap between all species analyzed and mara was low to moderate, and potential predator visits to the surrounding of the burrows did not vary according to the presence of juveniles. Our results suggest that in this system, predators behave as opportunistic predators of mara's juveniles. Mara's social and reproductive behavior varies along the distribution range of the species, therefore it is of great ecological value to analyze and understand the variations of its interactions with predators in different regions and environments. [ABSTRACT FROM AUTHOR]

This article proposes a novel account for the overuse of free morphemes and underuse of bound morphemes in English as a second language (L2) based on the framework of Distributed Morphology. It will be argued that an Economy Principle 'Do everything in Narrow Syntax (DENS)' operates in the L2 learner's computational system. Consequently, derivation in Morphology becomes as limited as possible except when applying Vocabulary Items to syntactic objects (Vocabulary Insertion). This results in non-target-like use/acceptance of certain morphemes: Bound morphemes are often omitted in early L2 grammar, and alternative free morphemes may apparently be used instead. Two types of data, namely the overuse of be reported in previous research, and the preference of to- infinitives over -ing gerunds in early L2 grammar, will be presented in support of the proposal, and the plausibility of the operation of DENS will be discussed. [ABSTRACT FROM AUTHOR]

Abstract The giant otter (Pteronura brasiliensis) is an endangered mammal that occupies aquatic environments, especially in the Amazon Rainforest and Pantanal wetlands in South America. The species uses shelters (dens and campsites), such as burrowed tunnels and tangles of branches and roots along watercourses, where it feeds mainly on fishes. In Espírito Santo Creek (northern portion of the Pantanal wetlands in the state of Mato Grosso, Brazil), 60 shelters (45 dens and 15 campsites) were identified and georeferenced during 12 fieldtrips between 2002 and 2003. The density was 1.8 dens/km. The shelters were significantly found in locations with partial (35%) or complete (55%) plant cover. The dens were dug mainly in soil associated with roots located, on average, 4.4 m in distance and 2.4 m in height in relation to the waterline. The campsites had a significantly smaller distance and height compared to the dens. The greater density of dens in the study area underscores the need for conserved environments with little human interference for the protection of giant otter populations. The vegetal coverage of riparian forests and the occurrence of ravines along Espírito Santo Creek offer greater protection to the shelters, hindering the access of predators to the interior of the shelter. Studies integrating biological and ecological knowledge with social participation in areas of occurrence of the giant otter are fundamental to the conservation of the species and its habitat in the Pantanal wetlands of Mato Grosso, Brazil.

Background: Fractures can occur in various locations within the odontoid process with differing orientations. However, little is known about what factors contribute to the anterior versus posterior angles/orientation of these fractures. Methods: We evaluated 74 patients with odontoid fractures (2013-2018) from a single-institution. Patients' fracture angles/orientations were measured on computed tomography studies, and were grouped into oblique posterior (OP) or oblique anterior (OA) groups. We also took into account cervical sagittal balance utilizing upright x-rays. Other variables studied included patients' ages, sagittal balance measurements, and the mechanisms of injury. Results: Fracture angles were significantly steeper in the OP group. OP fractures had larger C2-C7 sagittal vertical axis, occiput-C2 angles, and occiput-C7 angles versus anteriorly oriented fractures. In our linear regression model, advanced age and large occiput-C2 angles were predictive of the odontoid fracture angle. Patients who sustained ground-level falls also had significantly steeper fracture angles versus those involved in motor vehicle accidents. Conclusion: The odontoid tends to fracture at a steep, posterior angle in elderly patients who demonstrate a large positive sagittal balance when the head is extended following a ground-level falls. [ABSTRACT FROM AUTHOR]

The pathogenesis of Chiari 1 malformations has been explained in several different ways, but extensive evidence suggests a relationship between loss of volume within the posterior cranial fossa and Chiari 1 presentations. It is important to be able to differentiate Chiari 1.5 from Chiari 1 malformations as they have similar clinical presentations, but the latter have progressed further and are characterized by caudal herniations of the brain stem through the foramen magnum. Despite the similarities of presentation, Chiari 1.5 malformations have greater rates of complications following posterior decompression surgeries, which are typically performed to relieve ventral compression. An improved understanding of the odontoid synchondroses could lead to better understanding of Chiari malformations and lead to improved treatment of patients with these presentations. Here we present a rare case of an accessory odontoid synchondrosis in a patient with a Chiari 1.5 malformation and ventral compression. [ABSTRACT FROM AUTHOR]

The San Joaquin kit fox is listed as federally Endangered and California Threatened, primarily due to habitat loss from agricultural, industrial, and urban developments. However, a population of kit foxes estimated at 200-400 persists within the city of Bakersfield, CA. This population appears to be demographically robust with a high probability of persistence. Thus, this population potentially could contribute to range-wide conservation and recovery efforts. The presence of this population in an urban environment creates management challenges. Management issues include human and pet safety, dens in inconvenient locations, and carcass disposal. Resolution of these issues generally is not difficult. Conservation challenges include roads and vehicles, rodenticides and other toxins, sports netting, den destruction during routine maintenance operations, interspecific competition and disease transmission, movement corridors, and regulatory policy. Although the Metropolitan Bakersfield Habitat Conservation Plan provides protective measures for kit foxes during new construction, such measures do not extend to operations, maintenance, and other routine activities. Furthermore, formal policies regarding management and conservation of urban kit foxes have not yet been developed by the U.S. Fish and Wildlife Service and California Department of Fish and Game, resulting in inconsistent responses to urban kit fox issues. Based on a public opinion survey, Bakersfield residents generally support conservation of urban kit foxes. Successful resolution of management issues will minimize conflicts and enhance efforts to conserve kit foxes.

Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda (Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cubs are highly vulnerable, which may significantly influence the selection of breeding sites by females. Here, we used infrared camera traps to monitor giant panda dens for 5.5 years in Foping National Nature Reserve (FNNR) to determine how interspecific factors affect den selection by wild female pandas. Results indicated that Asian black bears (Ursus thibetanus), yellow-throated martens (Martes flavigula), leopard cats (Prionailurus bengalensis), and masked palm civets (Paguma larvata) visited the dens frequently, and the presence of these species negatively influenced den selection by female pandas. Interestingly, the presence of rodents and terrestrial birds appeared to indicate den safety, and female giant pandas were not averse and even preferred dens with a high abundance index of rodents and terrestrial birds. The den suitability index (DSI) was a reliable tool for evaluating whether dens were suitable for female giant pandas to give birth to and rear cubs, with preference for dens with high DSI values. This study increases our understanding of the den selection criteria of female giant pandas and the main threats to the survival of their cubs, thus providing important guidance for the conservation and management of this species. [ABSTRACT FROM AUTHOR]

Traumatic spinal epidural hematomas (TSEDH) are rare, with the reported incidence being < 1% of all spinal injuries. Causes of TSEDHs include vertebral fractures, obstetrical birth trauma, lumbar punctures, postsurgical bleeding, epidural anesthesia, and missile injuries. The retrodental location has not been reported as a location for spontaneous epidural hematoma. A 4-year-old boy was admitted to our Emergency Department after falling down and experiencing head trauma. Glasgow Coma Scale score was 15/15 with no neurologic deficit. Brain computed tomography scan showed isolated hyperdense hematoma in the retrodental area without any fractures in the skull or cervical vertebrae. Brain and cervical magnetic resonance imaging showed a retrodental acute hematoma that was isointense in T1-weighted sequences and hypointense in T2-weighted sequences. The hematoma was in the epidural space with possible odontoid process intracapsular origin. Isolated retrodental epidural hematoma without dens fracture is an extremely rare pathology and finding, and to the best of our knowledge, this is the first case to be reported in the literature. Emergency physicians should consider this pathology for any patients presenting for head trauma with head hematoma. [ABSTRACT FROM AUTHOR]

More than 460 cases of sarcoptic mange (Sarcoptes scabiei) in endangered San Joaquin kit foxes (SJKF; Vulpes macrotis mutica) have been reported in Bakersfield, California, US. Because SJKF are a den-obligate species, their dens have been proposed as a route of transmission. We determined whether SJKF den temperatures and humidities could support mite off-host survival based on previously published estimates of off-host mite survival times. We monitored SJKF dens for 6 d in summer and winter of 2017 and 2018 using temperature- and humidity-sensing data loggers placed within the dens. Motion-triggered cameras monitored animal use of and entrances into the dens. Linear regression models were fitted to the published mite survival data to predict estimated mite survival time (EMST) in SJKF dens based on observed mean temperature and humidity of the den. Den covariates including irrigation, type of den, and season were then fitted to a mixed effects linear model to predict EMST. The average EMST across various habitats in Bakersfield was 4.8 d; the longest EMST was 7.1 d for dens in habitats with irrigated grass in the winter. Den climatic conditions in Bakersfield may support off-host mite survival through a timeframe adequate for revisitation by another fox. The finding that irrigation may enhance EMST suggested that risk to foxes varied with den type and that mitigation strategies may need to vary with den types. [ABSTRACT FROM AUTHOR]

Dens invaginatus is a rare malformation affecting the teeth. The teeth that are most commonly affected are the permanent maxillary lateral incisors. The mandibular posterior teeth are rarely affected by dens invaginatus. In most of the cases, a single dens invaginatus is seen affecting the tooth. Cases of double dens invaginatus affecting a single tooth are rare, and those of triple dens invaginatus in a single tooth are even rarer. Here, we present a case of a 14-year-old where three dens invaginatus were seen in the mandibular second premolar. This is the fourth case of three dens invaginatus in a single tooth as only three have been reported previously.

Wolf Canis lupus reproductive success may be enhanced by access to favorable habitat with limited disturbance during denning season. Therefore, protection of den sites can be an important management strategy for maintaining viable wolf populations. On Prince of Wales Island in southeast Alaska, USA, management agencies recommend protection of dens and surrounding home ranges. However, these agencies are concerned current protection buffer sizes might be inadequate to promote pup-rearing success. To inform management decisions regarding buffers surrounding wolf dens, we used wolf GPS collar data during 2012–2016 to quantify core and home range area sizes during denning season. We used an autocorrelated kernel density estimator (AKDE) to calculate the extent of home ranges and fit individual wolf movement models. Breeding wolves used smaller core (AKDE 50% isopleth = 6 km2, SD = 4 km2) and home range areas (AKDE 95% isopleth = 57 km2, SD = 17 km2) during denning season (15 April–15 June) than non-breeding wolves at active dens (core = 69 km2, SD = 45 km2; home range = 252 km2, SD = 161 km2). Home ranges for breeding wolves and wolves belonging to a reproductive pack were smaller than non-breeding wolves throughout the pup-rearing period (15 April–31 July). The mean minimum and maximum distance from the core area edge to the active den site (1186–6326 m) varied widely but was smaller for breeding wolves (734–2308 m), and all distances exceeded the existing recommended den buffer distance (366 m). These results underscore the importance of evaluating individual variation in space use when considering management actions intended to protect cooperative breeders or other social carnivores. Wolf managers should recognize the current protection buffer around dens constitutes only a portion of the core area used by breeding wolves, and habitat alterations near den sites may force breeding wolves to use sub-optimal habitat they would normally avoid. [ABSTRACT FROM AUTHOR]

Abstract: Research on the project "Traditional Knowledge of Chukotka Native Peoples on the Polar Bear and Its Habitat" was carried out in the years 1999-2003. One of the main objectives of the project was to collect information about the location of polar bear dens. The studies were based on individual interviews with the most active hunters and elders from native villages located within the polar bear range. Fifty-three people from 20 villages were questioned. Data on 278 den locations in the period from 1943 to 2002, as well as on the pattern of denning area use, were obtained. All dens and denning areas were mapped. Based on this information, 17 areas with regular and relatively high den densities were outlined. The total number of females that annually reproduced on the Chukotka mainland and offshore islands in the 1990s was estimated to be approximately 100-200 individuals. Possible options for changes in the reproductive strategy of females from the Alaska-Chukotka subpopulation against the background of an increase in the rate of loss of the sea ice habitat in the Pacific part of the Arctic are considered. [ABSTRACT FROM AUTHOR]

Endangered San Joaquin kit foxes (Vulpes macrotis mutica; SJKF) and California ground squirrels (Otospermophilus beecheyi; CAGS) occur sympatrically in many locations. CAGS can constitute a nuisance species and control strategies have included lethal measures administered within CAGS burrows. These measures could harm or kill a SJKF if mistakenly applied to an occupied SJKF den. To identify attributes to distinguish between SJKF dens and CAGS burrow, we assessed dimensions, penetration depths by 9.7-cm and 7.5-cm spheres, ejecta patterns, and the presence of various types of sign at 65 dens to which radiocollared SJKF were tracked and at 80 burrows that CAGS were observed to enter. Mean entrance height, width, and circumference all were significantly larger for SJKF den entrances. However, the ranges of values for all dimensions for the CAGS burrows completely encompassed the ranges for the SJKF dens. Penetration depths with the 7.5-cm sphere were similar for SJKF dens and CAGS burrows. The 9.7-cm sphere could not be inserted in over half of CAGS burrows and exceeded 1 m in depth in over half of the SJKF dens. Most SJKF dens had dirt berms but so did over half of the CAGS burrows. SJKF scats, prey remains, CAGS scats, and trash were observed at both SJKF dens and CAGS burrows although at different frequencies. CAGS tracks were only observed at seven CAGS burrows. None of the attributes we assessed provided unequivocal criteria for distinguishing between SJKF dens and CAGS burrows. Also, SJKF occasionally usurp CAGS burrows and CAGS occasionally move into vacant SJKF dens. Therefore, administering lethal control measures within burrows should be avoided as it presents too great a risk to SJKF as well as the many other species that also use CAGS burrows. [ABSTRACT FROM AUTHOR]