Histological and MRI brain atlas of the common shrew, Sorex araneus, with brain region-specific gene expression profiles.

The common shrew, Sorex araneus, is a small mammal of growing interest in neuroscience research, as it exhibits dramatic and reversible seasonal changes in individual brain size and organization (a process known as Dehnel's phenomenon). Despite decades of studies on this system, the mechanisms behind the structural changes during Dehnel's phenomenon are not yet understood. To resolve these questions and foster research on this unique species, we present the first combined histological, magnetic resonance imaging (MRI), and transcriptomic atlas of the common shrew brain. Our integrated morphometric brain atlas provides easily obtainable and comparable anatomic structures, while transcriptomic mapping identified distinct expression profiles across most brain regions. These results suggest that high-resolution morphological and genetic research is pivotal for elucidating the mechanisms underlying Dehnel's phenomenon while providing a communal resource for continued research on a model of natural mammalian regeneration. Morphometric and NCBI Sequencing Read Archive are available at https://doi.org/10.17617/3.HVW8ZN.

Impact of Breast Density Legislation on Breast Cancer Risk Assessment and Supplemental Screening: A Survey of 110 Radiology Facilities.

Breast density notification laws, passed in 19 states as of October 2014, mandate that patients be informed of their breast density. The purpose of this study is to assess the impact of this legislation on radiology practices, including performance of breast cancer risk assessment and supplemental screening studies. A 20-question anonymous web-based survey was emailed to radiologists in the Society of Breast Imaging between August 2013 and March 2014. Statistical analysis was performed using Fisher's exact test. Around 121 radiologists from 110 facilities in 34 USA states and 1 Canadian site responded. About 50% (55/110) of facilities had breast density legislation, 36% of facilities (39/109) performed breast cancer risk assessment (one facility did not respond). Risk assessment was performed as a new task in response to density legislation in 40% (6/15) of facilities in states with notification laws. However, there was no significant difference in performing risk assessment between facilities in states with a law and those without (p < 0.831). In anticipation of breast density legislation, 33% (16/48), 6% (3/48), and 6% (3/48) of facilities in states with laws implemented handheld whole breast ultrasound (WBUS), automated WBUS, and tomosynthesis, respectively. The ratio of facilities offering handheld WBUS was significantly higher in states with a law than in states without (p < 0.001). In response to breast density legislation, more than 33% of facilities are offering supplemental screening with WBUS and tomosynthesis, and many are performing formal risk assessment for determining patient management.

Factors associated with repetitive strain, and strategies to reduce injury among breast-imaging radiologists.

PURPOSE: To investigate the prevalence of repetitive strain injury (RSI) among breast-imaging radiologists, the factors associated with such symptoms, and strategies to reduce injury. METHODS: In 2012, an anonymous survey regarding RSI and work habits was administered to 2,618 physician members of the Society of Breast Imaging via e-mail. Analysis of 727 (27.8%) de-identified responses was completed using STATA 12.1. Pain levels before and after implementation of digital imaging were compared with the Wilcoxon signed-rank test. The associations between RSI symptoms and work habits were assessed with logistic regression and test for trend. RESULTS: In the survey 438 of 727 (60.2%) respondents reported RSI symptoms, and 242 of 727 (33.3%) reported prior diagnosis/treatment. Results showed a statistically significant trend for the odds of RSI symptoms to increase with decreasing age (P = .0004) or increasing number of daily hours spent working (P = .0006), especially in an awkward position (P < .0001). Respondents recalled a significant increase in pain level after implementation of PACS, and a decrease in pain after ergonomic training or initiating use of an ergonomic mouse, adjustable chair, or adjustable table (P < .001, all comparisons). Only 17.7% (129 of 727) used an ergonomic mouse and 13.3% (97 of 727) had attended ergonomic training. Those with RSI symptoms or prior diagnosis of a Repetitive Strain Syndrome (RSS) were more likely to desire future ergonomic training compared with those without symptoms or injury (odds ratio 5.36, P < .001; odds ratio 2.63, P = .001, respectively). CONCLUSIONS: RSI is highly prevalent among breast-imaging radiologists nationwide and may worsen after implementation of PACS or with longer work hours. Ergonomic training and ergonomic devices may diminish or prevent painful RSI among radiologists.

Magnetic resonance imaging of stress injury of the cuneiform bones in patients with plantar fasciitis.

OBJECTIVE: The authors reported the magnetic resonance (MR) appearance of stress fractures of the cuneiform bones in patients with plantar fasciitis and performed a review of the literature on stress fractures associated with plantar fasciitis. MATERIALS AND METHODS: The authors performed a retrospective review of their experience with 5 cases of cuneiform stress fractures and associated plantar fasciitis. The medical records and MR examinations were reviewed. A literature search was performed on the PubMed search engine. RESULTS: There were 5 patients (1 man and 4 women) with stress fractures of at least 1 cuneiform bone. Patients' age ranged from 41 to 77 years, and their average weight was 212 lb. All patients had heel pain and either midfoot or lateral foot pain. There were 2 intermediate, 1 medial, and 3 lateral cuneiform stress fractures seen on MR imaging in these 5 patients. Two of these patients had undergone plantar fasciotomy, and all 5 had been treated with steroid injections. CONCLUSION: Plantar fascia injury, changes in gait, large body habitus, and excessive or new onset of exercise regimens are all potential causes of cuneiform stress fractures. Although the incidence of cuneiform stress fractures is extremely rare, they may occur in patients with plantar fasciitis.

Residence at moderate altitude improves ventilatory response to high altitude.

BACKGROUND: This study compared the distribution of arterial oxygen saturation (SaO2) and susceptibility to Acute Mountain Sickness (AMS) in moderate altitude residents (MAR) and low altitude residents (LAR) following rapid ascent to 4056 m. METHODS: Resting PETCO2 and SaO2 were measured in 38 subjects residing for > 3 mo near Colorado Springs, CO (MAR group), at 1940 m (USAF Academy), and after approximately 1 h at 4056 m on the summit of Pikes Peak, CO, following ascent by car. SaO2 was also measured at 610-m elevation intervals during the ascent. Of the LAR (50 m) group, 39 subjects were exposed to a similar ascent profile in a hypobaric chamber. RESULTS: At 1940 m the MAR SaO2 and PETCO2 were 94 +/- 1% (X +/- SD) and 33.6 +/- 2.8 mmHg, respectively. At 3048 m and higher, MAR SaO2 decreased, reaching 86 +/- 2% (p < 0.001) at 4056 m, and PETCO2 (32.1 +/- 4.5 mmHg) decreased (p < 0.05). At 50 m the LAR SaO2 and PETCO2 were 98 +/- 1% and 38.7 +/- 2.7 mmHg, respectively. At 1940 m and higher, LAR SaO2 decreased (p < 0.001), reaching 82 +/- 5% at 4056 m, and PETCO2 (36.4 +/- 3.5 mmHg) decreased (p < 0.05). Above 2438 m, the MAR SaO2 was higher (p < 0.001) than the LAR. Only one MAR subject, but nine LAR subjects reported AMS symptoms. CONCLUSIONS: Ventilatory acclimatization developed during moderate altitude residence substantially enhances arterial oxygenation during rapid ascents to higher altitudes. Compared with prior studies, the level of ventilatory acclimatization achieved at moderate altitude is similar to residing at 4056 m for approximately 5-9 d.

Asymmetries in population growth regulated by intraspecific competition: Empirical studies and model tests.

The linearity assumption in the logistic model of population growth is violated for nearly all organisms. Two simple models, the θ-logistic and the θ-Ricker, are shown to account for asymmetric patterns of population growth for 27 species of Drosophila and for a variety of other organisms, where the data were derived from the literature. These models are developed so as to aid laboratory and field ecologists to anticipate the dynamics of various experimental organisms. Potential problems of data gathering and model applications for experimental ecologists and wild life management biologists are identified. Intraspecific asymmetries offer alternative explanations to the "habitat selection" model, and the "higher order interactions" or coalitions model, for interspecific competition.