An increasing number of convolutional neural networks for fracture recognition and classification in orthopaedics:are these externally validated and ready for clinical application?

Aims: The number of convolutional neural networks (CNN) available for fracture detection and classification is rapidly increasing. External validation of a CNN on a temporally separate (separated by time) or geographically separate (separated by location) dataset is crucial to assess generalizability of the CNN before application to clinical practice in other institutions. We aimed to answer the following questions: are current CNNs for fracture recognition externally valid?; which methods are applied for external validation (EV)?; and, what are reported performances of the EV sets compared to the internal validation (IV) sets of these CNNs? Methods: The PubMed and Embase databases were systematically searched from January 2010 to October 2020 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The type of EV, characteristics of the external dataset, and diagnostic performance characteristics on the IV and EV datasets were collected and compared. Quality assessment was conducted using a seven-item checklist based on a modified Methodologic Index for NOn-Randomized Studies instrument (MINORS). Results: Out of 1,349 studies, 36 reported development of a CNN for fracture detection and/or classification. Of these, only four (11%) reported a form of EV. One study used temporal EV, one conducted both temporal and geographical EV, and two used geographical EV. When comparing the CNN’s performance on the IV set versus the EV set, the following were found: AUCs of 0.967 (IV) versus 0.975 (EV), 0.976 (IV) versus 0.985 to 0.992 (EV), 0.93 to 0.96 (IV) versus 0.80 to 0.89 (EV), and F1-scores of 0.856 to 0.863 (IV) versus 0.757 to 0.840 (EV). Conclusion: The number of externally validated CNNs in orthopaedic trauma for fracture recognition is still scarce. This greatly limits the potential for transfer of these CNNs from the developing institute to another hospital to achieve similar diagnostic performance. We recommend the use of geographical EV and statements such as the Consolidated Standards of Reporting Trials–Artificial Intelligence (CONSORT-AI), the Standard Protocol Items: Recommendations for Interventional Trials–Artificial Intelligence (SPIRIT-AI) and the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis–Machine Learning (TRIPOD-ML) to critically appraise performance of CNNs and improve methodological rigor, quality of future models, and facilitate eventual implementation in clinical practice

What is the long-term clinical outcome after fragility fractures of the pelvis? - A CT-based cross-sectional study

Background: Recently, Rommens and Hoffman introduced a CT-based classification system for fragility fractures of the pelvis (FFP). Although fracture characteristics have been described, the relationship with clinical outcome is lacking. The purpose of this study was to get insight into the type of treatment and subsequent clinical outcome after all types of FFP. Methods: A cross-sectional cohort study was performed including all elderly patients (≥ 65 years) with a CT-diagnosed FFP, between 2007-2019 in two level 1 trauma centers. Data regarding treatment, mortality and clinical outcome was gathered from the electronic patient files. Patients were asked to complete patient-reported outcome measures (PROMs) regarding physical functioning (SMFA) and quality of life (EQ-5D). Additionally, a standardized multidisciplinary treatment algorithm was constructed. Results: A total of 187 patients were diagnosed with an FFP of whom 117 patients were available for follow-up analysis and 58 patients responded. FFP type I was most common (60%), followed by type II (27%), type III (8%) and type IV (5%). Almost all injuries were treated non-operatively (98%). Mobility at six weeks ranged from 50% (type III) to 80% type II). Mortality at 1 year was respectively 16% (type I and II), 47% (type III) and 13% (type IV). Physical functioning (SMFA function index) ranged from 62 (type III and IV) to 69 (type II) and was significantly decreased (P=<0.001) compared to the age-matched general population. Quality of life was also significantly decreased, ranging from 0.26 (type III) to 0.69 (type IV). Conclusions: FFP type I and II are most common. Treatment is mainly non-operative, resulting in good mobility after six weeks, especially for patients with FFP type I and II. Mortality rates at one year were substantial in all patients. Physical functioning and quality of life was about 20-30% decreased compared to the general population

Similarity of Traveling-Wave Delays in the Hearing Organs of Humans and Other Tetrapods

Transduction of sound in mammalian ears is mediated by basilar-membrane waves exhibiting delays that increase systematically with distance from the cochlear base. Most contemporary accounts of such “traveling-wave” delays in humans have ignored postmortem basilar-membrane measurements in favor of indirect in vivo estimates derived from brainstem-evoked responses, compound action potentials, and otoacoustic emissions. Here, we show that those indirect delay estimates are either flawed or inadequately calibrated. In particular, we argue against assertions based on indirect estimates that basilar-membrane delays are much longer in humans than in experimental animals. We also estimate in vivo basilar-membrane delays in humans by correcting postmortem measurements in humans according to the effects of death on basilar-membrane vibrations in other mammalian species. The estimated in vivo basilar-membrane delays in humans are similar to delays in the hearing organs of other tetrapods, including those in which basilar membranes do not sustain traveling waves or that lack basilar membranes altogether

Optimalisatie van het openbaar groen

Het openbaar groen is een belangrijk onderdeel in de steden en dorpen. Iedereen die dit afstudeerwerkstuk leest, neemt hier bewust of onbewust deel aan. Het beheren van dit gezamenlijke groen blijkt echter steeds moeilijker te worden. Bestaande, maar ook nieuwe planten en bomen sterven steeds sneller af. De huidige klimaatverandering speelt hier een grote rol in. De doelstelling van dit onderzoek is oplossingsrichtingen geven om het openbaar groen beter in te richten naar aanleiding van de vele plant- en boomsterfte. Hieruit is de hoofdvraag geformuleerd: Hoe kan het openbaar groen zo ingericht worden, dat de sterfte van beplanting en bomen minimaal is

Effects of brood size manipulations on sexual attractiveness of offspring in the zebra finch

In a laboratory study the effect of brood size manipulations on the sexual attractiveness of offspring was investigated. Zebra finches, Taeniopygia guttata, were reared in small or large broods. Young were exchanged so that natural siblings from different rearing conditions could be compared. Birds of both sexes reared in small broods were larger and heavier as adults; furthermore, they developed the adult bill colour sooner than birds reared in large broods. Males reared in small broods had a redder beak as adults. Males but not females reared in small broods were more attractive to opposite sex individuals, as measured in choice tests. Males with redder beaks were more attractive to females. No relation was found in females between attractiveness and measured traits. Sexual attractiveness may thus be a potentially important mechanism by which brood size affects fitness. (C) 1996 The Association for the Study of Animal Behaviour

Host finding and feeding in Hydrotaea irritans (diptera, muscidae):The role of chemical senses

Hydroteae irritans is commonly considered to be the primary vector for the bacteria which cause summer mastitis in cattle. A behavioral physiology approach was used to investigate potential host odours (kairomones) that may be used by the fly in finding its host and to determine which substrates or sites on the host may be utilised in feeding. Attractant odours include CO2 and butyric, propionic and acetic acids: the latter three are also produced by the bacteria causing summer mastitis. When milk, slaver, nasal secretion, mastitis secretion and blood were offered to flies as feeding substrates only the last three produced significant increases in feeding duration in comparison to controls offered distilled water.Hydroteae irritans is commonly considered to be the primary vector for the bacteria which cause summer mastitis in cattle. A behavioral physiology approach was used to investigate potential host odours (kairomones) that may be used by the fly in finding its host and to determine which substrates or sites on the host may be utilised in feeding. Attractant odours include CO2 and butyric, propionic and acetic acids: the latter three are also produced by the bacteria causing summer mastitis. When milk, slaver, nasal secretion, mastitis secretion and blood were offered to flies as feeding substrates only the last three produced significant increases in feeding duration in comparison to controls offered distilled water

Diagnostic values for skin temperature assessment to detect diabetes-related foot complications

Skin temperature assessment is a promising modality for early detection of diabetic foot problems, but its diagnostic value has not been studied. Our aims were to investigate the diagnostic value of different cutoff skin temperature values for detecting diabetes-related foot complications such as ulceration, infection, and Charcot foot and to determine urgency of treatment in case of diagnosed infection or a red-hot swollen foot. Materials and Methods: The plantar foot surfaces of 54 patients with diabetes visiting the outpatient foot clinic were imaged with an infrared camera. Nine patients had complications requiring immediate treatment, 25 patients had complications requiring non-immediate treatment, and 20 patients had no complications requiring treatment. Average pixel temperature was calculated for six predefined spots and for the whole foot. We calculated the area under the receiver operating characteristic curve for different cutoff skin temperature values using clinical assessment as reference and defined the sensitivity and specificity for the most optimal cutoff temperature value. Mean temperature difference between feet was analyzed using the Kruskal-Wallis tests. Results: The most optimal cutoff skin temperature value for detection of diabetes-related foot complications was a 2.2 degrees C difference between contralateral spots (sensitivity, 76%; specificity, 40%). The most optimal cutoff skin temperature value for determining urgency of treatment was a 1.35 degrees C difference between the mean temperature of the left and right foot (sensitivity, 89%; specificity, 78%). Conclusions: Detection of diabetes-related foot complications based on local skin temperature assessment is hindered by low diagnostic values. Mean temperature difference between two feet may be an adequate marker for determining urgency of treatment