TORTICOLLIS CAUSED BY NEUROENTERIC CYST OF UPPER CERVICAL REGION

Objective:Torticollis is a symptom that can be related to different pathological mechanisms ranging from simple to life-threatening conditions. Here we report a child with torticollis caused by a neuroenteric cyst in the upper cervical region; this is a very rare condition in childhood and  in this case, it was successfully resolved by surgery.Clinical presentation:A 2.5 year old boy presented with a 2 month-history of torticollis, he had developed paraparesia 2 weeks before admission. At examination he was found to be quadriparetic. Radiographic study of  the cervical spine revealed widening of the cervical canal. Brain and spinal magnetic resonance imaging revealed a hypointense lesion on the T1 at the craniovertebral junction having a  compressive effect on the anterior aspect of the brain stem and spinal cord.Intervention:The patient underwent surgery. After craniotomy and opening of the dura, a cystic lesion was seen; clear fluid was aspirated and the cyst wall was removed.Conclusion:Considering the quadriparesis and torticollis, the patient improved significantly within the first few days after surgery. No relapse of symptoms occurred during the follow up period. This is the first case report of a child in whom torticollis was due to a neuroenteric cyst of the upper cervical intradural region.Keywords:Torticollis - Neuroenteric cyst - Child - Quadriparesi

Order of invasion affects the spatial distribution of a reciprocal intraguild predator

When intraguild predation is reciprocal, i.e. two predator species kill and feed on each other, theory predicts that well-mixed populations of the two species cannot coexist. At low levels of the shared resource, only the best competitor exists, whereas if the level of the common resource is high, the first species to arrive on a patch can reach high numbers, which prevents the invasion of the second species through intraguild predation. The order of invasion may therefore be of high importance in systems with reciprocal intraguild predation with high levels of productivity, with the species arriving first excluding the other species. However, natural systems are not well mixed and usually have a patchy structure, which gives individuals the possibility to choose patches without the other predator, thus reducing opportunities for intraguild predation. Such avoidance behaviour can cause spatial segregation between predator species, which, in turn, may weaken the intraguild interaction strength and facilitate their co-occurrence in patchy systems. Using a simple set-up, we studied the spatial distribution of two reciprocal intraguild predators when either of them was given priority on a patch with food. We released females of two predatory mite species sequentially and found that both species avoided patches on which the other species was resident. This resulted in partial spatial segregation of the species and thus a lower chance for the two species to encounter each other. Such behaviour reinforces segregation, because heterospecifics avoid patches with established populations of the other species. This may facilitate coexistence of two intraguild predators that would exclude each other in well-mixed populations

More Than Smell - COVID-19 Is Associated With Severe Impairment of Smell,Taste, and Chemesthesis

Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19-79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change +/- 100) revealed a mean reduction of smell (-79.7 +/- 28.7, mean +/- standard deviation), taste (-69.0 +/- 32.6), and chemesthetic (-37.3 +/- 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis.The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms

A Numerical Analysis of Partial Slip Problems Under Hertzian Contacts

[[abstract]]In this study the tangential partial slip problems in Hertzian contact regions are treated by a numerical technique. The tangential loading may include tangential forces in the contact plane and a twisting moment normal to the contact plane. The Coulomb’s law of friction and the property that the direction of friction must oppose the relative motion lead to nonlinear equations. The Newton-Raphson method is utilized to solve these nonlinear equations. Numerical results for tangential tractions and sizes of stick and slip zones may be determined, and they agree with existing analytical results for circular contacts.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[countrycodes]]NL