Back Of Head Research Articles

Assessment of potential strain injury to rectus capitis posterior minor muscles during whiplash type distortions of the cervical spine.

Whiplash type injuries resulting from a rear end motor vehicle accident (REMVA) are thought to be caused by excessive loading and displacement of structural components of the cervical spine. On impact, the seat propels the driver's torso forward relative to the head, resulting in forced flexion of the occipitoatlantal (OA) joint, accompanied by forced stretching of the rectus capitis posterior minor (RCPm) muscles. Flexion of the OA joint and stretching of the RCPm muscles continues to increase until the vehicle's headrest strikes the back of the driver's head. It is known that externally applied forces that attempt to move the OA joint beyond its anatomic barrier can result in fracture, dislocation, or soft tissue damage to its structural components. However, the magnitude of headrest backset, defined as the distance between the driver's head and the vehicle's headrest, that would result in RCPm muscles being stretched to a length that would put them at risk for a muscle strain injury is unknown. To quantify the relationships among flexion of the OA joint, RCPm muscle stretch, and backset, and to quantify the biomechanical response of RCPm muscles to increasing levels of axial load due to stretching. Unembalmed head and neck specimens from three White females aged 85, 63, and 70 years were obtained from the Anatomical Services Division at the University of Maryland. Donors had provided written consent allowing use of their body for research purposes. Using an analytic model of the OA joint, the relationships between flexion of the OA joint and RCPm muscle stretch as a function of backset were estimated. RCPm muscles were removed from the cadavers and forcibly stretched using a servomechanism controlled hydraulic testing machine to quantify the load/displacement properties. After testing, the tissues were sectioned, mounted, and stained using Masson's trichrome to selectively stain muscle fibers red and collagen blue. Forced flexion of the OA joint was seen to be directly related to the magnitude of headrest backset. For values of backset greater than 7.2cm, biomechanical testing of the RCPm muscles revealed that strain injuries ranged from the tearing of a few muscle fibers to complete rupture of the muscle and separation of the tendon at the posterior process of C1. Results showed that headrest backset at the time of vehicle impact is an important factor in estimating the risk of muscle strain injury to RCPm muscles. Muscle strain injury would be expected to impact the functional relationship between the RCPm muscles and the pain sensitive spinal dura. Physicians should be alert to the possibility that cervicogenic pain patients who have experienced whiplash associated with REMVA may show clinically relevant structural damage to the RCPm muscles on MRI.

A new species of Dixonius (Squamata: Gekkonidae) from Vientiane Capital, Laos.

A new species of the gekkonid genus Dixonius is described from Huaysorn-Huaysua village, Nasaithong District, Vientiane Capital, Laos. The new species can be distinguished from all other species by a combination of the following characters: maximum SVL 47.1 mm; 1921 longitudinal rows of dorsal tubercles at midbody; 2326 longitudinal rows of ventrals across the abdomen; 7 or 8 supralabials, 6 in mid-orbital position; 5 or 6 infralabials; 5 or 6 precloacal pores in males, femoral pores lacking; precloacal and femoral pores absent in females; a canthal stripe running from rostrum through the eye and terminating at back of head; dorsum brown with irregular dark marks. In phylogenetic analyses, the species is recovered as the sister taxon to D. siamensis, which occurs in Laos, Thailand, and Vietnam. Genetically, the two species are approximately 9.4% divergent from each other based on the complete mitochondrial ND2 gene with six partial or complete adjacent tRNAs. It is the 12th species known in the genus Dixonius and the second Dixonius species described from Laos.

Dynamic balance and neuropathic changes following ankle proprioceptive training in type II diabetic patients with peripheral neuropathy

Introduction: Peripheral neuropathy is one of the major complications of type II diabetes mellitus. Lower limb proprioceptive impairments due to neuropathy can lead to balance disorders in these patients. The present study aimed to investigate postural stability and neuropathic changes following ankle proprioceptive training in type II diabetic patients with moderate neuropathy. Materials and Methods: The present study was conducted on 24 type II diabetic patients with moderate neuropathy (9 females and 15 males) aged 40-65 years (with a mean age of 57.25 years). The treatment consisted of ankle proprioceptive training by the balance board and rocker for 10 consecutive days. Balance indices, including Overall Stability Index (OSI), Anterior-Posterior Stability Index (APSI), and Medial-Lateral Stability Index (MLSI), were measured with Biodex system before and after the treatment, as well as two weeks after treatment in two conditions: condition1: Eyes open, head straight, without using trunk, pelvis, thigh, and knee constrained orthosis. Condition 2: Eyes closed, head back (hyperextension), with using trunk, pelvis, thigh, and knee constrained orthosis. Plate-based Biodex stability was fixed at levels 6 and 8 for condition1 and level 8 for condition 2. The severity of neuropathy was assessed using Valk and Michigan questionnaires, as well as light touch sensation. The analysis of variance with repeated measure was used to evaluate alterations in the stability of patients. Furthermore, the correlation of neuropathic changes and stability parameters were assessed by the Pearson correlation coefficients. Results: Significant improvements were observed in OSI in all tests of condition 1 (Biodex Balance System (BBS) at level 8 (P=0.001) and level 6 (P=0.017), as well as test conditions 2 (level 8; P=0.004). After the treatment, at stability level 8, a significant improvement in the mean values of postural sways in the Anterior-Posterior (AP) direction demonstrated that the ankle strategy was improved in the patients. After the treatment, the scores of the Valk (P=0.02) and Michigan (P=0.001) questionnaires were significantly decreased. After two weeks of follow-up, the observed improvement was maintained in the mean values of balance indices (OSI, APSI) and neuropathy due to treatment. Conclusion: As evidenced by the obtained results, 10 sessions of targeted ankle proprioceptive training improved stability, neuropathy, and light touch sensation of the foot in type II diabetic patients with moderate neuropathy. Foot somatosensory information is one of the most important causes of balance alterations in these patients

Ewes behavioural and physiological reactions to the odour of fox (Lycalopex gymnocercus) and wild boar (Sus scrofa) faeces

Predation of sheep is a production problem that deserves the studies of how this prey species detects and react to predators. In this context, this study determined the behavioural and physiological responses of ewes exposed to the odour of predators’ faeces as fox (Lycalopex gymnocercus) and wild boar (Sus scrofa). Four experimental treatments were applied to 48 Corriedale sheep (12 ewes each): fox faeces (FFO), wild boar faeces (WBFO), unknown sheep wool (SWOC) and no odour (NOC). All ewes were evaluated in a behavioural test for 5 min and then rectal temperature was measured, and a series of blood samples were obtained to determine cortisol concentration, glycaemia, total protein, albumin and globulin. The frequency of kicking the ground, turning their head, going back and stillness behaviours increased significantly in FFO in comparison with NOC (p = 0.01; p < 0.0001; p = 0.005 and p = 0.002, respectively) and kicking the ground and turning the head compared with SWOC (p = 0.03 and p < 0.001 respectively). The FFO group spent significantly more time turning the head and going back than NOC (p < 0.001 and p = 0.01 respectively) and SWOC (p = 0.002 and p = 0.05). For ewes evaluated with WBFO, kicking the ground, turning their head, going back and remaining still occurred significantly more times than with NOC (p = 0.008; p = 0.005; p = 0.01 and p = 0.003), and kicking the ground, turning their head and remaining still occurred significantly more times than with SWOC (p = 0.02; p = 0.02 and p = 0.05). Furthermore, WBFO group spent significantly less time still (p = 0.01) and more time turning their head and going back (p = 0.001 and p = 0.02, respectively) than NOC, that spent significantly more time turning their head than SWOC (p = 0.006). Rectal temperature and haematological variables were not affected by treatments. The increase in the frequency of agonistic behaviours and duration of locomotion behaviours in ewes treated with predators’ faeces, allow us to conclude that ewes respond to fox and wild boar’s faeces exposure with a similar aversive behavioural repertoire. Also, ewes displayed some physiological responses although these responses cannot be attributed to the odour of predators.

Determinants of Hospital Length of Stay among Burn Patients Using Quantile Regression

Determinants of Hospital Length of Stay among Burn Patients Using Quantile Regression

The Need for Three Separate Parallel WAD Ratings of Whiplash Injuries to Cervical, Lumbosacral, and Thoracic Spine in Clinical Assessments of Injured Motorists

Background: The prevailing classification of whiplash associated disorder (WAD) focuses solely on neck injuries, thus implying that injuries to other spinal regions are relatively inconsequential. In fact, some whiplash studies exclude patients with injuries to lower spine. We examined whiplash pain locations of injured motorists and their statistical correlates. Method: De-identified archival data of 158 injured motorists (57 men and 101 women; mean age 39.4 years, SD=12.5) were reviewed statistically. Their motor vehicle accidents (MVAs) occurred 7 to 194 weeks previously (mean=50.7 weeks, SD=38.5), but all still experienced active whiplash symptoms requiring therapy. Results: The most frequently reported locations of whiplash pain were the head (89.9%), neck (88.6%), shoulders (80.4%), and lower back (77.8%). WAD studies that exclude patients with lower back pain might exclude about 82.9% of injured motorists: the remaining 17.1% of patients with whiplash injury only to the neck are presumably those less adversely affected by the MVA than patients with pain in multiple locations. No correlations of high or moderate magnitude were detected among the various pain locations. Furthermore, no high or moderate correlations were observed between clinical variables (including 2 neuropsychological symptoms scales) and reports of headache or pain in the neck or in lower back. Discussion and Conclusions: The prevailing WAD classification system needs to be renamed as specific to neck injury only: WAD-C. Parallel WAD classification systems need to be introduced separately for the lumbosacral spine (as WAD-LS) as well as the thoracic spine (as WAD-T) to improve diagnostic descriptive precision of clinical WAD assessments and of their research applications.

Work Profile and Hazards Review Study of Workers in Small Scale Enterprises

The review study highlight the rigorous work profile of the workers in small scale industries and depict how the hazards caused to them in their daily life are affecting their health. Different hazards such as very severe pain in neck, head, shoulders, fingers, hands, and lower back were identified, always leading to various musculoskeletal disorders. A need to improve workstation and workplace environment to make it user friendly to workers is felt so the workers could be comfortable is highlighted in all the studies. The study has its focus majorly on the craft industries and presents the plight of the jewelers specially. Proper task analysis and work rest pattern are identified as useful to alleviate the mental fatigue and to improve work efficiency of the workers.

Gone

Gone Linda Wastila (bio) The late-May morning I drove east from Chapel Hill, I didn't pay much mind to the tracts of yellowed corn and soy or the tobacco-curing sheds standing derelict. As I headed home, Ma beside me, my junior year and final exams behind me, all that filled my head was catching up on sleep and getting ready for my summer internship at the National Institutes of Health. [End Page 18] Click for larger view View full resolution Photo by Renee Grayson [End Page 19] "Fred Jarvis had a heart attack over Easter," Ma said. "Didn't get the seed in. Probably a good thing, what with this drought." "I hope you made him pay the lease," I said. "Don't be cold, Clayton. Poor man's bedridden." "Jesus, Ma. He has kids to help. We can't afford to take on his twohundred-acre problems." She patted my thigh. "Don't worry. I leased ten acres to a girl from up north. She's farming daylilies." The space behind my eyes pinched. "Flowers? Now there's a real moneymaker." Ma got quiet and scribbled in her sketchpad. I mumbled an apology. She coughed low in her throat, polite, like she was holding back. The AC rattled, working hard. The road curled through Kingsboro, past the Barbeque Lodge and the Purina factory. When we passed the hog-rendering plant, the air took on a sulfuric edge. At the east end of town, I steered right at what had once been the far corner of family land, now a used-car dealership. The town peeled away in the side-view mirror, replaced by red clay. Ma leaned against the window, eyes closed, sketchbook fallen at her feet. Her cheekbones jutted sharp against her skin. The zygomatics, I remembered, from my anatomy final. Yesterday, when we'd met in the cool dim of the art museum, I'd found her sitting on the leather bench, gazing at sepia-colored paintings of tobacco leaves and buds, her botanical creations that she'd donated to the collection. The same spot where I sat when I needed to destress from school. When she stood up and I pulled her into my hug, she felt as insubstantial as a dragonfly wing. The car rolled into the next intersection. An ancient oak anchored the corner. The Kissing Tree, we'd called it in high school, for the mistletoe dripping from its uppermost branches. Fifty feet back, under the oak's shade, stood one of the original slave shacks, modernized with electricity and running water. I'd helped Daddy install the porcelain on my tenth birthday. The year before he passed. Ma stirred. "That's the lily farm," she said. "The owner lives in the cabin." "I hope you're charging rent." "She's hiring," Ma said. "Needs someone with a strong back and a sharp mind." [End Page 20] "Plenty of strong backs around here," I said. "The sharp minds, though, that's a problem." "Don't be a snob—I raised you better than that. There's more to smarts than book learning." Her words stung. Money was tight. My scholarship helped, and if I shaved off a semester and got early admission to med school, all the better. The NIH internship paid a small stipend, but I'd use most of it for room and board. State school was fine, but I aimed higher—Duke, Yale, maybe Harvard. "Sorry, Mama," I said. "I'm tired from finals." "You have all summer to rest up." "I'm leaving for my internship in two weeks," I reminded her. "I'll be back Labor Day." To pack my belongings, share a few meals, and head back to school. Back to the real world. Ma reached over and stroked the back of my neck. "Well, get a haircut before you go," she said, soft-like, then stared back out the window. ________ Too tired to sleep, I wandered the three-bedroom ranch that had never felt like home, flipping through her sketchbooks, the piles of overdue bills, turning the television on, then off. From her bedroom in the back, Ma hacked and wheezed. She...

Sunflower inflorescences absorb maximum light energy if\xa0they face east and afternoons are cloudier than mornings

The mature inflorescence of sunflowers (Helianthus annuus) orients eastward after its anthesis (the flowering period, especially the maturing of the stamens), from which point it no longer tracks the Sun. Although several hypothetical explanations have been proposed for the ecological functions of this east facing, none have been tested. Here we propose an atmospheric-optical explanation. Using (i) astronomical data of the celestial motion of the Sun, (ii) meteorological data of diurnal cloudiness for Boone County located in the region from which domesticated sunflowers originate, (iii) time-dependent elevation angle of mature sunflower heads, and (iv) absorption spectra of the inflorescence and the back of heads, we computed the light energy absorbed separately by the inflorescence and the back between anthesis and senescence. We found that the inflorescences facing east absorb the maximum radiation, being advantageous for seed production and maturation, furthermore west facing would be more advantageous than south facing. The reason for these is that afternoons are cloudier than mornings in the cultivation areas of sunflowers. Since the photosynthesizing green back of mature heads absorbs maximal energy when the inflorescence faces west, maximizing the energy absorbed by the back cannot explain the east facing of inflorescences. The same results were obtained for central Italy and Hungary, where mornings are also less cloudy than afternoons. In contrast, in south Sweden, where mornings are cloudier than afternoons, west-facing mature inflorescences would absorb the maximum light energy. We suggest that the domesticated Helianthus annuus developed an easterly final orientation of its mature inflorescence, because it evolved in a region with cloudier afternoons.

DanielSusskindA World Without Work: Technology, Automation and How We Should RespondMetropolitan Books, 2020. 305 p. $28.00

DanielSusskindA World Without Work: Technology, Automation and How We Should RespondMetropolitan Books, 2020. 305 p. $28.00

Soundz at the Back of My Head

Research Article| November 01 2020 Soundz at the Back of My Head Thomas F. DeFrantz/slippage Thomas F. DeFrantz/slippage Search for other works by this author on: This Site Google Theater (2020) 50 (3): 69–85. https://doi.org/10.1215/01610775-8651221 Cite Icon Cite Share Icon Share Twitter Permissions Search Site Citation Thomas F. DeFrantz/slippage; Soundz at the Back of My Head. Theater 1 November 2020; 50 (3): 69–85. doi: https://doi.org/10.1215/01610775-8651221 Download citation file: Zotero Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter Books & JournalsAll JournalsTheater Search Advanced Search The text of this article is only available as a PDF. © 2020 by Thomas F. DeFrantz/slippage2020 Article PDF first page preview Close Modal Issue Section: Articles You do not currently have access to this content.

SARS-CoV-2 Infection in Children: Special Considerations.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) appeared in December 2019 in Wuhan, Hubei province, China. Soon after, it was discovered to be a novel human virus and it subsequently spread throughout the world, leading to a global pandemic. From the experience we have so far with this virus, it appears that compared to most other respiratory viral illnesses to which they are typically highly susceptible, children are affected less by SARS-CoV-2 than adults. It will continue to be important to collect data and study different populations to learn more about how children are affected by the disease, particularly as we head back to school in different forms this fall. We also must pay close attention to whether or not children are significant transmitters of the disease, as this is largely unknown and will have an affect on those who are providing care for children at school, daycare, and at home. [Pediatr Ann. 2020;49(10):e407-e412.].

Positional Installation of Intranasal Corticosteroids in the Treatment of Chronic Rhinosinusitis: A Systematic Review of the Literature.

First-line treatment of chronic rhinosinusitis includes topical corticosteroids aimed at decreasing inflammation of sinonasal mucosa. No guidelines exist regarding the effect of head position during administration of corticosteroids. We hypothesize certain positions enhance delivery to the paranasal sinuses, with further improvement in delivery after sinus surgery. A systematic review of the literature was conducted using Medline Ovid, Embase, Scopus, and Cochrane databases. All studies evaluating intranasal medications administered in 2 or more head positions were included. Study population, head position(s), method/volume of delivery, and outcome metrics were recorded. Twenty-four studies compared head positions and their role in distribution of intranasal medication. Of 12 papers studying surgically naive subjects, 6 found improvement in delivery to specific sinonasal regions (middle meatus; lateral, superior, or posterior nasal cavity) and/or symptomatic improvement, in the lying head back (LHB) or head down and forward (HDF) positions, but only 3 reached statistical significance. Of 12 papers studying surgically altered patients, 10 found delivery improved in the HDF, LHB, and head forward 45° or 90° positions. Of 5 studies of extended frontal sinus procedures (Draf IIb/III), a majority found distribution to the frontal sinus improved with the head forward 90° position. Patients found the HDF position most uncomfortable. Studies found no statistically significant difference in distribution to unoperated sinuses among different head positions. A minority of studies supported the use of the LHB and HDF positions. This suggests that in surgically naive patients, intranasal corticosteroid delivery to sinonasal regions and/or symptomatic improvement may be best achieved with the sinuses positioned inferior to the delivery device. Surgery improved distribution to the paranasal sinuses regardless of head position, although tilting the head forward 90° was particularly effective in delivery to the frontal sinus after extended frontal sinus procedures.

Defining pain and interference recovery trajectories after acute non-catastrophic musculoskeletal trauma through growth mixture modeling

BackgroundRecovery trajectories support early identification of delayed recovery and can inform personalized management or phenotyping of risk profiles in patients. The objective of this study was to investigate the trajectories in pain severity and functional interference following non-catastrophic musculoskeletal (MSK) trauma in an international, mixed injury sample.MethodsA prospective longitudinal cohort (n = 241) was formed from patients identified within four weeks of trauma, from attendance at emergency or urgent care centres located in London, ON, Canada, or Chicago, IL, USA. Pain interference was measured via the Brief Pain Inventory (London cohort) or the Neck Disability Index (Chicago cohort). Pain severity was captured in both cohorts using the numeric pain rating scale. Growth mixture modeling and RM repeated measures ANOVA approaches identified distinct trajectories of recovery within pain interference and pain severity data.ResultsFor pain interference, the three trajectories were labeled accordingly: Class 1 = Rapid recovery (lowest intercept, full or near full recovery by 3 months, 32.0% of the sample); Class 2 = Delayed recovery (higher intercept, recovery by 12 months, 26.7% of the sample); Class 3 = Minimal or no recovery (higher intercept, persistently high interference scores at 12 months, 41.3% of the sample). For pain severity, the two trajectories were labeled: Class 1 = Rapid recovery (lower intercept, recovery by 3 months, 81.3% of the sample); and Class 2 = Minimal or no recovery (higher intercept, flat curve, 18.7% of the sample). The “Minimal or No Recovery” trajectory could be predicted by female sex and axial (vs. peripheral) region of trauma with 74.3% accuracy across the 3 classes for the % Interference outcome. For the Pain Severity outcome, only region (axial trauma, 81.3% accuracy) predicted the “Minimal or No Recovery” trajectory.ConclusionsThese results suggest that three meaningful recovery trajectories can be identified in an international, mixed-injury sample when pain interference is the outcome, and two recovery trajectories emerge when pain severity is the outcome. Females in the sample or people who suffered axial injuries (head, neck, or low back) were more likely to be classed in poor outcome trajectories.Trial registrationNational Institutes of Health - clinicaltrials.gov (NCT02711085; Retrospectively registered Mar 17, 2016).

Determining pain in patients with voice disorders: a qualitative study

Aim The present study aimed to determine pain in patients with voice disorders (PWVDs). Patients and methods A total number of 28 patients with a range of voice disorders and without any other diseases participated in the study. To gain maximum variation, purposive sampling method was used. Moreover, semi-structured interviews were employed for data collection. The interviews were then continued until data saturation was reached, and the data were subsequently recorded and transcribed verbatim. Qualitative content analysis was utilized for data analysis. Results Data analysis of the interviews emerged three themes about pain experienced by PWVDs. The emerged themes included location of pain, type of pain, and time of pain occurrence. In this respect, PWVDs reported pain in different locations on their body including head, ears, anterior neck, posterior neck, larynx, temporomandibular joint, submandibular area, shoulders, and upper back. Furthermore, chronic, acute, severe, and mild were the most common types of pain reported by PWVDs. The PWVDs also stated that they had experienced pain at different times, i.e. during speaking, after long-time speaking, after voice use, during swallowing, during palpation, and all the time (even at rest). Conclusions One of the physical discomforts experienced by PWVDs is pain. According to the results of the present study, pain should properly be considered in the assessment and treatment of PWVDs in clinical practices. Also, our study suggested that a specific scale is needed to measure pain in voice disorders.

New insight into Parkinson's disease-related impairment of the automatic control of upright stance.

Parkinson's disease (PD) affects the automatic control of body movements. In our study, we tested PD-related impairments in automatic postural control in quiet upright stance. Twenty PD patients (mean age: 60±8years; Hoehn and Yahr: 2.00±0.32, on-drug) and twenty age-matched controls (61±7years) were recruited. We studied interrelations between center-of-pressure movements, body movements (head, neck, and lower back), eye movements and variability of pupil size. Participants performed two fixation tasks while standing, during which they looked at: (a) a cross surrounded by a white background; and (b) a cross surrounded by a structured visual background (images used: rooms in houses). PD patients exhibited stronger and weaker correlations between eye and center-of-pressure/body movement variables than age-matched controls in the white and structured fixation tasks, respectively. Partial correlations, controlling for variability of pupil size showed that PD patients used lower and greater attentional resources than age-matched controls to control their eye and center-of-pressure/body movements simultaneously in the white fixation and structured fixation tasks, respectively. In the white fixation task, PD patients used attentional resources to optimize visuomotor coupling between eye and body movements to control their posture. In the structured fixation task, the salient visual stimuli distracted PD patients' attention and that possibly affected postural control by deteriorating the automatic visuomotor coupling. In contrast, age-matched controls were able to use surrounding visual background to improve the automatic coupling between eye and center-of-pressure movements to control their posture. These results suggest that cluttered environments may distract PD patients and deteriorate their postural control.

Challenges in topical therapy of chronic rhinosinusitis: The case of nasal drops application – A systematic review

ObjectiveChronic rhinosinusitis (CRS) is a common health issue associated with a significant life quality impairment. Intranasal glucocorticoid is the treatment of choice both as initial therapy as well as after surgery. In contrast to nasal spray, liquid glucocorticoids in form of nasal drops have the advantage of reaching the middle and upper meatus. The efficiency of the glucocorticoid nasal drops is nevertheless strictly dependent on the head position they are being applied in. Several head positions have been described in the literature but no clear recommendation towards the best suited position exist to date. MethodsA systematic review was completed using the PubMed database. Journal articles assessing the effect of head position on intranasal drop fluid distribution, clinical effectiveness, or factors affecting patient compliance were included. ResultsIn total 15 publications meeting the inclusion criteria have been found, out of which 9 cover the effect of head position as a primary outcome using quantitative measures. ConclusionsThe positions Lying Head Back, Lateral Head Low, and variations of those can be recommended equally at the moment. Evidence speaks against the use of the classic Head Back position because of poor clinical outcome, and against the position Head Down and Forward as initial therapeutic approach because of high discomfort. For the olfactory cleft, a new head position has been described (Kaiteki), although no comparisons to other positions exist to date.

Effect of music from headphone on pedestrians

The objective of this study is to examine whether vehicle alerting sounds from the back of pedestrians such as car horn and bicycle bell can be detected by pedestrians or not if they are listening to the music from an headphone at the same time. The laboratory measurement data from an artificial human head demonstrated that the sound level and spectrum trend of the music from headphone together with alerting sound from the back of the human head were almost identical with that of music from headphone. In addition, the sound level of the alerting sound was also much lower than that of the alerting sound + music. These findings are very significant and it can prove that pedestrians are not able to notice the vehicle alerting sound from the back if they are listening to music from an headphone at that time.

Imaging through a homogeneous circular cylinder: the role of virtual caustics, rainbow glare points, and image fragmentation.

Small air bubbles on the rear inside surface of a water-filled cylinder, near its edges, appear horizontally elongated, joined in pairs, and take on color. Similarly, if an extended object is sufficiently close to the water-filled cylinder, three images of the object are seen when looking through the cylinder. The center image joins onto the left or right image as the observer moves his or her head back and forth in front of the cylinder. The first observation is explained in terms of glare points of light, and the real and virtual parts of the external caustic of the light transmitted through the water-filled cylinder. The second observation is explained as an example of Berry's caustic touching theorem which describes the topological method of fragmentation of an object's image into multiple images. For the situation studied here, an imaginary cylindrical aberration caustic of the water-filled cylinder decomposes object space into a three-ray region sandwiched between two one-ray regions. As an extended object crosses the caustic boundary from one of the one-ray regions into the three-ray region, an image-pair creation event occurs, which is followed by an image-pair disconnection event producing the three images. Similarly, when the extended object crosses the caustic boundary from the three-ray region into one of the one-ray regions, an image-pair merging event occurs, which is followed by an image-pair annihilation event producing the one remaining image.

Shoulder Release and Tendon Transfer following Neonatal Brachial Plexus Palsy: Gains, Losses, and Midline Function.

Shoulder release and tendon transfer is frequently performed to address persistent weakness from neonatal brachial plexus palsy. Although postoperative improvements in motion are well described, associated deficits are poorly documented, and functional assessments are lacking. Loss of ability to reach midline can occur with surgery and may result in impairment. The purpose of this study was to comprehensively assess the gains, losses, functional changes, and patient-reported outcome associated with the authors' surgical approach. Consecutive patients undergoing surgery with 2-year follow-up were included (n = 30). Prospectively recorded assessments by therapists were reviewed. Changes were assessed by t test and Wilcoxon rank sum (p < 0.05). Active external rotation and abduction improved and internal rotation diminished. Aggregate modified Mallet score increased with improvements in all subscales, except that hand to spine was unchanged and hand to belly decreased. Functional assessment using the Brachial Plexus Outcome Measure revealed an increase of aggregate score, with no decline in any subscales. Improvements were in hand to back of head, forward overhead reach, holds plate with palm up, opening large container, and strings bead. Aggregate patient self-report of appearance and function increased (from 18 to 23). Loss of ability to reach midline occurred in three patients (10 percent) who had extended Erb or total palsy and preoperative limitations of internal rotation. Secondary reconstruction rebalances shoulder motion by increasing external rotation and abduction and reducing internal rotation. In this study, a conservative surgical approach results in overall improvement in task-based abilities and self-reported outcomes and preservation of internal rotation within a functional range. Therapeutic, IV.