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Environmental and climatic factors, as well as host demographics and behaviour, significantly influence the exposure of herbivorous mammalian hosts to pathogens such as Bacillus anthracis, the causative agent of anthrax. Until the early 1990s in Kruger National Park (KNP), kudu (Tragelaphus strepsiceros) was the host species most affected by anthrax, with outbreaks occurring predominantly in the dry season, particularly during drought cycles. However, the most affected host species has shifted to impala (Aepyceros melampus), with more frequent anthrax outbreaks during the wet season. This study investigates the roles of environmental variation and other host species in this shift. Temporal trends in environmental variables such as precipitation, soil moisture, temperature, and normalised difference vegetation index (NDVI) were analyzed in relation to anthrax occurrence (presence/ absence and counts). Additionally, correlations between host species' densities and anthrax mortalities over time were examined. Anthrax cases in 1990 were concentrated in the central and northern regions of KNP (excluding Pafuri), primarily affected kudus; while subsequent mortalities affected mostly impala and were restricted to the far north, in Pafuri. Significant correlations were found between kudu anthrax mortality and a decrease in NDVI, average temperature, SPI-6 and SPI-12 (Standardised Precipitation Index in various time intervals. Conversely, anthrax occurrence in impalas was associated with a decline in SPI-3, and temperature rise, with increased mortality during the rainy season. Elephant density correlated negatively with kudu mortality, but a positive correlation with both impala mortality and impala density. The study concludes that environmental variables and species' densities may alter the diversity and frequency of hosts exposed to B. anthracis. Climate extremes and alterations therein may exacerbate anthrax severity by modifying species susceptibility and their probability of exposure over time.

Robust monitoring techniques, capable of showing change in the savanna when change has occurred, are a prerequisite for better managing this ecosystem. The Step Point Method is a well-established technique in South African range surveys (Short and Morris 2016). However, it is often considered inaccurate in describing vegetation dynamics in the savanna herbaceous layer due primarily to issues with sample sizes and cover estimates, its inability to capture the spatial heterogeneity and patchy distribution typical of these ecosystems, sensitivity to observer bias, reliance on relative values and poor inclusion of sparse or less common species. This study aimed to test the effectiveness and accuracy of the Step Point Method for monitoring the herbaceous layer of savanna by comparison to absolute densities of plants. The results show that the Step Point Method only recorded 41–50% of species richness. It overestimated the relative species richness of grasses by 17.4% while underestimating that of forbs by 13.8% on average. The relative abundance of grasses was overestimated by 32.4%, while that of forbs was underestimated on average by 28.4%. Dominance was overestimated by 115.5% on average, and species diversity was underestimated by 15%. Considering these shortcomings, the Step Point Method should be used with extreme caution in studies focusing on monitoring temporal and spatial changes in veld condition and for biodiversity management.

Pediatric button battery ingestion is known to cause potentially devastating injuries to the aerodigestive tract. Placement of a button battery in the nasal passages and subsequent damage it may cause poses a unique management problem as it may involve bony and membranous scarring, aesthetic irregularities, and long-term nasal obstruction. We present a case of a child with complete stenosis of the right nasal vestibule after a button battery injury. With a multidisciplinary surgical approach between an otolaryngologist and a plastic surgeon, the nasal airway patency was restored via a series of dilations and stents. The patient now has a patent right nasal airway that measures equal in diameter to the contralateral side. We conclude that in the case of a child with a button battery in the nose, repair of stenosis may be approached similarly to a case of unilateral choanal atresia, including dilations and stents.

The Kruger National Park's (KNP) long-running experimental burn plots (EBPs) have a history of research projects, which improve the understanding of fire in savanna ecosystems. Using data from KNP's aerial censuses (2005-2016) and in situ dung count data (2008-2017), this study assessed (1) herbivore densities on the Satara, N'Wanetsi and Marheya EBPs, on annual, triennial and no-burn treatments and across pre-, during and post-drought climate conditions; (2) herbivore densities of these EBPs relative to their non-manipulated surroundings and (3) the extent to which distance to water and rainfall influence ungulate densities. The results revealed that herbivore mean density differed significantly between the three EBPs of Satara and across their fire treatments. N'Wanetsi showed the highest density (0.30 animals/ha), whilst the lowest was found at Marheya (0.12 animals/ha). Overall, pre-drought density was higher on the annual plots (0.56 animals/ha), whilst higher post-drought density was evidenced on the triennial plots (0.80 animals/ha). On average, there were significantly higher herbivore densities on the EBPs (2.54 animals/ha) compared to the surrounding matrix at the larger scales of the Satara management section (0.15 animals/ha) and the central KNP (0.18 animals/ha). A positive correlation between herbivore mean density estimate and distance to water was shown. However, grazer mean density across fire treatments was strongly correlated to rainfall.Conservation implications: Given the variation in fire regimes and their application, and the non-uniform and elevated herbivore densities of the EBPs, inferences from the EBPs cannot be made to the larger KNP. The trials should rather be viewed as an isolated, fire herbivory experiment. It is also recommended to align the experiment with South African National Parks' mandate by including biodiversity parameters like small mammals and insects in the monitoring of the plots.

Subepidermal calcified nodules are benign entities that can be seen in the head and neck region and are part of a family of calcifying disorders known as calcinosis cutis, in which calcium is deposited in subcutaneous tissue. We describe a middle aged childhood boy with a rapidly enlarging ear mass of unknown aetiology who presents for otolaryngologic evaluation. In this case, surgical excision provided both definitive diagnosis and sufficient treatment. Although uncommon, it is important to recognise these lesions in order to appropriately counsel patients on management options and rule out underlying disorders that may be responsible for the pathology.

BackgroundNeuroimaging detection of sensorineural hearing loss (SNHL)-related temporal bone abnormalities is limited (20–50%). We hypothesize that cochlear signal differences in gray-scale data may exceed the threshold of human eye detection. Gray-scale images can be post-processed to enhance perception of tonal difference using “pseudo-color” schemes.ObjectiveTo compare patients with unilateral SNHL to age-matched normal magnetic resonance imaging (MRI) exams for “labyrinthine color differences” employing pseudo-color post-processing.Materials and methodsThe MRI database at an academic children’s hospital was queried for “hearing loss.” Only unilateral SNHL cases were analyzed. Sixty-nine imaging exams were reviewed. Thirteen age-matched normal MR exams in children without hearing loss were chosen for comparison. Pseudo-color was applied with post-processing assignment of specific hues to each gray-scale intensity value. Gray-scale and pseudo-color images were qualitatively evaluated for signal asymmetries by a board-certified neuroradiologist blinded to the side of SNHL.ResultsTwenty-six SNHL (mean: 7.6±3 years) and 13 normal control exams (mean: 7.3±4 years) were included. All patients had normal gray-scale cochlear signal and all controls had symmetrical pseudo-color signal. However, pseudo-color images revealed occult asymmetries localizing to the SNHL ear with lower values in 38%. Ninety-one percent of these cases showed concordance between the side of pseudo-color positivity and the side of hearing loss.ConclusionPseudo-color perceptual image enhancement reveals intra-labyrinthine fluid alterations on MR exams in children with unilateral SNHL. Pseudo-color image enhancement techniques improve detection of cochlear pathology and could have therapeutic implications.

Temporal bone dehiscence is an infrequent but clinically important phenomenon. Cochlear–facial dehiscence, the rarest type, has been described only in adults. We report cochlear–facial dehiscence in a child. Knowledge of this entity is imperative for radiologists searching for anatomical markers of inner ear pathology and for cochlear implant planning.

External auditory canal (EAC) stenosis is the narrowing of the external auditory meatus to less than 4 mm. Severe stenosis of the EAC may inhibit the ability to conduct sound and may lead to the formation of a cholesteatoma. While most cases of EAC stenosis may be managed nonoperatively, the significant impact that the associated symptoms can have on patients may require surgical intervention. Progression of the cholesteatoma can erode the bony ossicles, may encase the facial nerve, and impact infection risk causing chronic otorrhea, and further worsening patient quality of life. We present the case of a pediatric patient who presented due to chronic left-sided hearing loss. Further examination and imaging demonstrated near-total obstruction of the left EAC secondary to a soft tissue mass and evidence of bony hypertrophy. Following a canalplasty, the patient now has returned to baseline hearing and has no associated complications. Canalplasty remains a safe, effective surgical intervention for EAC stenosis complicated by cholesteatoma.