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Sample records for medial rectus weakness

  1. Congenital dystrophic medial rectus muscles

    PubMed Central

    Murthy, Ramesh

    2017-01-01

    We report two patients, one with congenital dystrophic medial rectus muscles and one with absence of the medial rectus muscles; in addition, one of them had absence of the lateral rectus muscles. While absence of the superior oblique and superior rectus has been more commonly reported in literature, especially with craniofacial syndromes, our patients were nonsyndromic. Considering the risk of anterior segment ischemia, correction of the large-angle exotropia was performed by horizontal rectus muscle surgery where possible, along with transfer of the superior oblique tendon to the superior part of the normal medial rectus muscle insertion area to create a tethering effect with a good outcome. PMID:28300745

  2. Medial rectus muscle anchoring in complete oculomotor nerve palsy.

    PubMed

    Lee, Si Hyung; Chang, Jee Ho

    2015-10-01

    The management of exotropia resulting from complete oculomotor nerve palsy is challenging. Conventional therapeutic interventions, including supramaximal resection and recession, superior oblique tendon resection and transposition, and several ocular anchoring procedures have yielded less-than-adequate results. Here we describe a novel surgical technique of anchoring the medial rectus muscle to the medial orbital wall in combination with lateral rectus disinsertion and reattachment to the lateral orbital wall.

  3. Ultrastructure of medial rectus muscles in patients with intermittent exotropia

    PubMed Central

    Yao, J; Wang, X; Ren, H; Liu, G; Lu, P

    2016-01-01

    Purpose To study the ultrastructure of the medial rectus in patients with intermittent exotropia at different ages. Patients and methods The medial recti were harvested surgically from 20 patients with intermittent exotropia. Patients were divided into adolescent (age<18 years, n=10) and adult groups (age >18 years, n=10). The normal control group included five patients without strabismus and undergoing eye enucleation. Hematoxylin and eosin staining and transmission electron microscopy were used to visualize the medial recti. Western blot was used to determine the levels of myosin and actin. Results Varying fiber thickness, atrophy, and misalignment of the medial recti were visualized under optical microscope in patients with exotropia. Electron microscopy revealed sarcomere destruction, myofilament disintegration, unclear dark and light bands, collagen proliferation, and fibrosis. The adolescent group manifested significantly higher levels of myosin and actin than the adult group (P<0.05). Conclusion Younger patients with intermittent exotropia show stronger contraction of the medial recti compared with older patients. Our findings suggest that childhood was the appropriate time for surgery as the benefit of the intervention was better than in adulthood. PMID:26514242

  4. Outcome of unilateral lateral rectus recession and medial rectus resection in primary exotropia

    PubMed Central

    2013-01-01

    Background The purpose of this study was to measure the success rate of unilateral lateral rectus recession and medial rectus resection in primary exotropia. Methods This is an interventional case series of 55 patients with primary exotropia (degree of deviation 15–85 PD), above the age of 5 years. Patients were treated in the Department of Ophthalmology, Jinnah Postgraduate Medical Center, Karachi, Pakistan, during the period of July 2009 to March 2010. All the patients underwent surgical procedure i.e., lateral rectus muscle recession (maximum up to 10 mm) and medial rectus muscle resection (up to 6 mm) of one eye, according to the Park’s method. Surgery was done based on prism cover test measurements obtained at 6 m with appropriate optical correction in place. Patients were re evaluated at one day, one month, two months and six months post operatively. Final outcome was considered at the end of six months at which achievement of ≤10 PD of exotropia was the success. Data was analyzed on SPSS version 17.0. Results We obtained success (≤10 PD) in 42 out of 55 patients (76.4%) and 13 out of 55 patients (23.6%) did not meet our criteria for surgical success (>10 PD). Analysis of success with the type of primary exotropia showed that success was achieved in 22 out of 24 cases of intermittent type (91.6%) and 20 out of 31 cases of constant type (64.5%)(P Value 0.019). The highest percentage of success was achieved in patients with the pre-operative deviation of ≤70 PD i.e., 93.3% (42 out of 45 cases), while none of the patients with the pre-operative deviation of >70 PD (10 out of 10 cases) achieved the criteria for success. Conclusion We conclude that pre-operative deviation is one of the strongest predictor for favorable surgical outcome. Therefore, eliminating the factors causing error in the correct determination of pre-operative deviation should improve the success and predictability of the surgical outcome. Despite the obstacles in the surgical

  5. Situational Restriction of Elevation in Adduction Relieved by Faden on the Medial Rectus

    PubMed Central

    Muralidhar, R.; Vijayalakshmi, P.; Sujatha, K.; Shetty, Shashikanth; Malay, K.; Rosenberg, Steve

    2016-01-01

    We describe a patient with situational restriction of elevation in adduction in his left eye. Clinical examination pointed to instability of the left medial rectus pulley. This was corrected by Faden on the medial rectus. The importance of this relatively new concept in identifying and treating orbital pulley instability is discussed. PMID:27162460

  6. Medial Rectus Recession Is as Effective as Lateral Rectus Resection in Divergence Paralysis Esotropia

    PubMed Central

    Chaudhuri, Zia; Demer, Joseph L.

    2013-01-01

    Objective To propose medial rectus (MR) recession to be equally as effective as lateral rectus (LR) resection, which has heretofore been the preferred treatment for divergence paralysis esotropia (DPE). Methods We examined a 17-year surgical experience comparing LR resection with MR recession in adults with DPE, defined as symptomatic distance esotropia (ET) at least double the asymptomatic ET of 10 or less prism diopters (Δ) at near. Results Twenty-four patients with DPE underwent surgery. Six patients underwent bilateral LR resection and 2 underwent unilateral LR resection (group L), while 13 underwent bilateral MR recession and 3 underwent unilateral MR recession, with the target angle double the distance ET (group M). One of 8 patients in group L and 15 of 16 patients in group M underwent intraoperative adjustable surgery under topical anesthesia. Mean (SD) preoperative central gaze ET measured 15.0 (7.7) Δ at distance and 4.1 (3.4) Δ at near in group L, but 10.4 (6.8) Δ at distance and 0.6 (1.7) Δ at near in group M (P=.15; distance, 0.003, near). Postoperatively, no patient in either group had symptomatic diplopia or convergence insufficiency in follow-up from 8.5 to 40 months. Twice the usual surgical dose of MR recession per prism diopter was required to achieve correction of the distance deviation in DPE as compared with that recommended for ET generally and also for LR resection in the same condition. Conclusions Recession of the MR provides binocular single vision in DPE without convergence insufficiency at near, and it is convenient for intraoperative adjustment under topical anesthesia. PMID:22688183

  7. Internal organization of medial rectus and inferior rectus muscle neurons in the C group of the oculomotor nucleus in monkey.

    PubMed

    Tang, Xiaofang; Büttner-Ennever, Jean A; Mustari, Michael J; Horn, Anja K E

    2015-08-15

    Mammalian extraocular muscles contain singly innervated twitch muscle fibers (SIF) and multiply innervated nontwitch muscle fibers (MIF). In monkey, MIF motoneurons lie around the periphery of oculomotor nuclei and have premotor inputs different from those of the motoneurons inside the nuclei. The most prominent MIF motoneuron group is the C group, which innervates the medial rectus (MR) and inferior rectus (IR) muscle. To explore the organization of both cell groups within the C group, we performed small injections of choleratoxin subunit B into the myotendinous junction of MR or IR in monkeys. In three animals the IR and MR myotendinous junction of one eye was injected simultaneously with different tracers (choleratoxin subunit B and wheat germ agglutinin). This revealed that both muscles were supplied by two different, nonoverlapping populations in the C group. The IR neurons lie adjacent to the dorsomedial border of the oculomotor nucleus, whereas MR neurons are located farther medially. A striking feature was the differing pattern of dendrite distribution of both cell groups. Whereas the dendrites of IR neurons spread into the supraoculomotor area bilaterally, those of the MR neurons were restricted to the ipsilateral side and sent a focused bundle dorsally to the preganglionic neurons of the Edinger-Westphal nucleus, which are involved in the "near response." In conclusion, MR and IR are innervated by independent neuron populations from the C group. Their dendritic branching pattern within the supraoculomotor area indicates a participation in the near response providing vergence but also reflects their differing functional roles.

  8. The Efficacy of Botulinum Toxin Treatment for Children with a Persistent Esotropia Following Bilateral Medial Rectus Recessions and Lateral Rectus Resections

    PubMed Central

    Lambert, Scott R.; Shainberg, Marla J.

    2015-01-01

    Background and Purpose To report on the outcomes of treating children with a persistent esotropia with an injection of botulinum toxin in a medial rectus muscle. Patients and Methods The medical records of all children at one institution with a persistent esotropia after bilateral medial rectus recessions and bilateral lateral rectus resections who were then treated with a botulinum toxin injection were reviewed. Results Five patients with a mean preoperative esotropia of 37 PD (range, 25-50 PD) underwent bilateral medial rectus recessions and then bilateral lateral rectus resections. Their residual esotropia (mean, 25 PD; range, 18-35) was then treated with a single injection of 3- 5 units of botulinum toxin into one medial rectus muscle. The patients were then followed for a mean of 34 months (range, 14 to 79 months). At last follow-up, 2 patients had an esotropia <10 PD. The other 3 patients had no long-term improvement in their ocular alignment. Two of these patients then underwent additional strabismus surgery. In both cases, they then developed a consecutive exotropia. Conclusion Treatment with a single injection of botulinum toxin was beneficial in 2 of 5 children. Botulinum toxin treatment alone did not result in a consecutive exotropia in any patients treated. PMID:24260804

  9. Bilateral combined resection and recession of the medial rectus muscle for convergence excess esotropia.

    PubMed

    Ramasamy, Balasubramanian; Rowe, Fiona; Whitfield, Kath; Nayak, Harish; Noonan, Carmel P

    2007-06-01

    Five patients with true convergence excess esotropia were surgically managed with combined resection and recession of the medial rectus muscles. This technique was chosen to address the near/distance angle disparity. The use of this surgical technique produced full asymptomatic binocular control at near and distance fixation in four patients. One patient developed a consecutive exotropia but regained full binocular control following a second surgical procedure.

  10. Surgical Responses of Medial Rectus Muscle Recession in Thyroid Eye Disease-Related Esotropia.

    PubMed

    Lyu, In Jeong; Lee, Ju-Yeun; Kong, Mingui; Park, Kyung-Ah; Oh, Sei Yeul

    2016-01-01

    We evaluate the surgical outcomes and surgical responses of medial rectus muscle (MR) recession patients with thyroid eye disease (TED)-related esotropia (ET). The surgical dose-response curves 1 week postoperatively and at the final visit were analyzed. Univariable and multivariable linear regression analyses were applied to investigate factors influencing surgical dose-response. A total of 43 patients with TED-related ET that underwent MR recession were included. The final success rate was 86.0% and the rate of undercorrection was 14.0%. The surgical dose-response curves of TED-related ET showed a gentle slope compared with those of standard surgical tables. In the univariable model, simultaneous vertical rectus muscle recession was the only significant factor influencing surgical dose-response of MR recession in TED-related ET (β = -0.397, P = 0.044). In a model adjusted for age, sex, type of surgery, and preoperative horizontal angle of deviation, simultaneous vertical rectus muscle recession showed marginal significance (β = -0.389, P = 0.064). The surgical dose-response curve of TED-related ET was unique. Simultaneous vertical rectus muscle recession was associated with increased surgical dose-response in TED-related ET.

  11. Surgical Responses of Medial Rectus Muscle Recession in Thyroid Eye Disease-Related Esotropia

    PubMed Central

    Lyu, In Jeong; Lee, Ju-Yeun; Kong, Mingui; Park, Kyung-Ah; Oh, Sei Yeul

    2016-01-01

    We evaluate the surgical outcomes and surgical responses of medial rectus muscle (MR) recession patients with thyroid eye disease (TED)-related esotropia (ET). The surgical dose-response curves 1 week postoperatively and at the final visit were analyzed. Univariable and multivariable linear regression analyses were applied to investigate factors influencing surgical dose-response. A total of 43 patients with TED-related ET that underwent MR recession were included. The final success rate was 86.0% and the rate of undercorrection was 14.0%. The surgical dose-response curves of TED-related ET showed a gentle slope compared with those of standard surgical tables. In the univariable model, simultaneous vertical rectus muscle recession was the only significant factor influencing surgical dose-response of MR recession in TED-related ET (β = -0.397, P = 0.044). In a model adjusted for age, sex, type of surgery, and preoperative horizontal angle of deviation, simultaneous vertical rectus muscle recession showed marginal significance (β = -0.389, P = 0.064). The surgical dose-response curve of TED-related ET was unique. Simultaneous vertical rectus muscle recession was associated with increased surgical dose-response in TED-related ET. PMID:26796354

  12. Intramuscular Cavernous Hemangioma of Medial Rectus Muscle in Paediatric Age Group

    PubMed Central

    Mehta, Anuj; Butola, Shalini; Abrol, Sangeeta; Kumari, Anju

    2017-01-01

    An 11-year-old male child presented with a mass on the nasal aspect of the right eye that has been there for the last 2 years. Extraocular movements were decreased in the right eye on levoversion, levoelevation, and levodepression. Local examination revealed a bluish mass with irregular surface and ill-defined margins located in the medial rectus muscle. The mass was 10 × 20 mm in size, firm, nodular, nontender, nonpulsatile, noncompressible, and nonreducible. MRI of the orbit revealed a well-defined mass of approximately 23 × 13 mm along the medial rectus (MR) muscle. It was hyperintense on T2W images with very minimal contrast enhancement. A provisional diagnosis of hemangioma or lymphangioma with intralesional haemorrhage was made. During surgical excision, the mass was found to be encapsulated by MR fibres. The MR fibres were separated, and the mass measuring 20 × 8 × 6.5 mm was removed and sent for histopathology. The histopathological examination revealed an intramuscular cavernous hemangioma.

  13. Renal Carcinoid Tumor Metastatic to the Uvea, Medial Rectus Muscle, and the Contralateral Lacrimal Gland.

    PubMed

    Kiratli, Hayyam; Uzun, Salih; Tarlan, Berçin; Ateş, Deniz; Baydar, Dilek Ertoy; Söylemezoğlu, Figen

    2015-01-01

    Renal carcinoid tumor is an exceedingly rare malignancy. A 57-year-old man with a renal carcinoid tumor discovered after metastasizing to intraocular and bilateral orbital structures is described. The patient presented with a blind painful OS and a right superotemporal subconjunctival mass. Imaging studies revealed a large left intraocular tumor, a mass in the left medial rectus muscle, and right lacrimal gland enlargement. The OS was enucleated, and incisional biopsies were performed from the other 2 lesions. Histopathological studies demonstrated metastatic neuroendocrine tumor with chromogranin and synaptophysin positivity. Systemic work up revealed a right renal mass and multiple hepatic metastatic lesions. Radical nephrectomy was performed, and octreotide, capecitabine, and temozolomide were administered. Removal of the primary tumor and the eye that had no prospect for useful vision and further treatment with octreotide, capecitabine, and temozolomide provided a disease progression-free period of 24 months and allowed the patient to function normally.

  14. Long-Term Outcome of Medial Rectus Recession and Pulley Posterior Fixation in Esotropia With High AC/A Ratio

    PubMed Central

    Wabulembo, Geoffrey; Demer, Joseph L.

    2014-01-01

    Purpose: Medial rectus (MR) recession with pulley posterior fixation (PF) can be used to treatesotropia (ET) with a high accommodative convergence to accommodation (AC/A) ratio as effectively in the short term as MR recession with scleral PF. This study provides a novel examination of the long-term results of MR recession with pulley PF (PPF). Methods: In 21 children we performed bilateral MR recession and pulley PF for ET greater at near than distance (high AC/A). Mean follow-up was 3.5 ± 2.5 (standard deviation [SD]) years. Results: Mean age at presentation was 2.7 ± 1.8 and at surgery 4.3 ± 1.6 years. Fourteen (67%) children had amblyopia. Distance and near pre-operative ET averaged 19.6Δ ± 10.5Δ and 36.9Δ ± 18.9Δ, respectively. Mean near-distance (N-D) disparity was 16.4Δ ± 12.3Δ. The MR recession averaged 4.4 ± 0.9 mm. Early mean postoperative ET was 1.3 ± 3.3Δ at distance and 2.8Δ ± 5.2Δ at near. Mean late postoperative ET was 0.1Δ ± 5.8Δ and 1.0Δ ± 6.2Δ at distance and near, respectively. At the final postoperative examination, mean N-D disparity was reduced to 0.9Δ ± 3.6Δ. Discussion: MR recession with PPF has a high long-term effectiveness, even in patients with amblyopia and autism. Since no posterior scleral suturing is required, it minimizes the perforation risk associated with scleral PF. Conclusion: MR recession with PPF is a safe and highly effective long-term treatment for ET with high AC/A ratio. Long-term results may surpass those of alternate procedures. PMID:22906381

  15. [How to understand the excessive lateral rectus muscle recession].

    PubMed

    Kang, Xiaoli; Wei, Yan

    2014-07-01

    Surgical treatments of intermittent exotropia include symmetric bilateral lateral rectus recession, symmetric bilateral medial rectus resection, asymmetric monocular lateral rectus recession and/or medial rectus resection, in which lateral rectus recession is the most common method. The maximum amount of lateral rectus recession, however, is still controversial. Bilateral lateral rectus recession 7-8 mm for 35(Δ)-40(Δ) exotropia and unilateral lateral rectus recession and medial rectus resection for exotropia larger than 40(Δ) are suggested by most doctor usually. But some other doctors advocated augmented bilateral lateral rectus recession (9-14 mm ) for exotropia larger than 50(Δ) or augmented unilateral lateral rectus recession for moderate angle exotropia (30(Δ)-35(Δ)), which brought confusion in practical clinical work. In this paper, we'll focus on the amount of lateral rectus recession, and discuss several common issues related to augmented lateral rectus recession, in order to provide references for the majority of clinicians.

  16. Avoiding Complications in Abdominal Wall Surgery: A Mathematical Model to Predict the Course of the Motor Innervation of the Rectus Abdominis.

    PubMed

    Tessone, Ariel; Nava, Maurizio; Blondeel, Phillip; Spano, Andrea

    2016-02-01

    Ever since its introduction, the transverse rectus abdominis myocutaneous flap has become the mainstay of autologous breast reconstruction. However, concerns regarding donor site morbidity due to the breach of abdominal wall musculature integrity soon followed. Muscle-sparing techniques, eventually eliminating the muscle from the flap all-together with the deep inferior epigastric artery perforator flap, did not eliminate the problem of abdominal wall weakness. This led to the conclusion that motor innervation might be at fault. Studies have shown that even in the presence of an intact rectus abdominis muscle, and an intact anterior rectus sheath, denervation of the rectus abdominis muscle results in significant abdominal wall weakness leading to superior and inferior abdominal bulges, and abdominal herniation. Our aim was to establish a mathematical model to predict the location of the motor innervation to the rectus abdominis muscle, and thus provide surgeons with a tool that will allow them to reduce abdominal morbidity during deep inferior epigastric artery perforator and free muscle-sparing transverse rectus abdominis myocutaneous surgery. We dissected 42 cadaveric hemiabdomens and mapped the course of the thoracolumbar nerves. We then standardized and analyzed our findings and presented them as a relative map which can be adjusted to body type and dimensions. Our dissections show that the motor innervation is closely related to the lateral vascular supply. Thus, when possible, we support the preferred utilization of the medial vascular supply, and the preservation of the lateral supply and motor innervation.

  17. Medial canthal support structures: the medial retinaculum: a review.

    PubMed

    Kang, Hyera; Takahashi, Yasuhiro; Nakano, Takashi; Asamoto, Ken; Ikeda, Hiroshi; Kakizaki, Hirohiko

    2015-04-01

    The medial canthus is supported by several structures with a complicated 3-dimensional arrangement in a narrow space. Although the medial canthal tendon occupies a major portion of the area, the medial canthal support structures include the following entities: Horner's muscle, the medial rectus capsulopalpebral fascia including the medial check ligament, the medial horn of the levator aponeurosis, the medial horn supporting ligament, the medial horn of the lower eyelid retractors, the preseptal part of the orbicularis oculi muscle, and 3 variations of the Lockwood's ligament. We named the composite of these structures the "medial retinaculum," which is similar to the "lateral retinaculum" of the lateral canthus. Profound comprehension and consideration of the medial retinaculum warrants safe and effective surgery in the medial canthal region.

  18. Rectus Femoris Tendon Calcification

    PubMed Central

    Zini, Raul; Panascì, Manlio; Papalia, Rocco; Franceschi, Francesco; Vasta, Sebastiano; Denaro, Vincenzo

    2014-01-01

    Background: Since it was developed, hip arthroscopy has become the favored treatment for femoroacetabular impingement. Due to recent considerable improvements, the indications for this technique have been widely extended. Injuries of the rectus femoris tendon origin, after an acute phase, could result in a chronic tendinopathy with calcium hydroxyapatite crystal deposition, leading to pain and loss of function. Traditionally, this condition is addressed by local injection of anesthetic and corticosteroids or, when conservative measures fail, by open excision of the calcific lesion by an anterior approach. Purpose: To assess whether arthroscopic excision of calcification of the proximal rectus is a safe and effective treatment. Study Design: Case series; Level of evidence, 4. Methods: Outcomes were studied from 6 top amateur athletes (age range, 30-43 years; mean, 32.6 years) affected by calcification of the proximal rectus who underwent arthroscopic excision of the calcification. Patients were preoperatively assessed radiographically, and diagnosis was confirmed by a 3-dimensional computed tomography scan. To evaluate the outcome, standardized hip rating scores were used pre- and postoperatively (at 6 and 12 months): the Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score, and Modified Harris Hip Score. Moreover, visual analog scales (VAS) for pain, sport activity level (SAL), and activities of daily living (ADL) were also used. Results: One year after surgery, all patients reported satisfactory outcomes, with 3 of 6 rating their return-to-sport level as high as preinjury level, and the remaining 3 with a percentage higher than 80%. Five patients ranked their ability to carry on daily activities at 100%. Statistical analysis showed significant improvement of the Oxford Hip Score, the Modified Harris Hip Score, and all 3 VAS subscales (pain, SAL, and ADL) from pre- to latest postoperative assessment (P < .05). Conclusion: Arthroscopic excision of

  19. Weakness

    MedlinePlus

    Lack of strength; Muscle weakness ... feel weak but have no real loss of strength. This is called subjective weakness. It may be ... flu. Or, you may have a loss of strength that can be noted on a physical exam. ...

  20. Convergence excess esotropia treated surgically with fadenoperation and medical rectus muscle recessions.

    PubMed

    Leitch, R J; Burke, J P; Strachan, I M

    1990-05-01

    Convergence excess esotropia has been treated with bifocals, miotics, medial rectus recession(s), fadenoperation, or a combination of these. However, comparatively few studies on the sensory status of these patients exist. We present the sensory findings in 31 children treated surgically. Twenty-one had fadenoperations combined with bimedial rectus recessions, one had a fadenoperation alone, and nine had augmented bimedial rectus recessions. Five children (16%) achieved bifoveal fusion, 22 (71%) had varying degrees of peripheral fusion, and four (13%) had no detectable binocularity after a mean postoperative follow-up of 2.4 years.

  1. Full-tendon nasal transposition of the vertical rectus muscles: a retrospective review.

    PubMed

    Dawson, Emma L M; Boyle, Natalie J; Lee, John P

    2007-01-01

    The authors report the results of a retrospective review of patients who underwent nasal transposition of the vertical rectus muscles between 1997 and 2004. Eight patients were identified, 4 males and 4 females. There was an average age at surgery of 37 years, with a range from 8 to 79 years. The aetiologies included 6 patients with trauma to their medial rectus (4 following endoscopic sinus surgery) and 2 patients with paralytic medial rectus muscles secondary to 3rd nerve palsy. All patients underwent whole tendon transposition of the superior and inferior rectus muscles, with resection of both muscles in 7 cases, before reattachment adjacent to the upper and lower borders of the medial rectus, respectively. One patient had a reduced amount of resection and this was combined with inferior oblique disinsertion and traction sutures. All patients had a reduction in deviation in the primary position and in 5 patients there was some improvement in adduction. A consequence of surgery was a degree of limitation of abduction, elevation and depression in some patients. Overall, patients were satisfied with the improvement in their appearance.

  2. Rectus sheath abscess after laparoscopic appendicectomy

    PubMed Central

    Golash, Vishwanath

    2007-01-01

    Port site wound infection, abdominal wall hematoma and intraabdominal abscess formation has been reported after laparoscopic appendicectomy. We describe here a rectus sheath abscess which occurred three weeks after the laparoscopic appendicectomy. It was most likely the result of secondary infection of the rectus sheath hematoma due to bleeding into the rectus sheath from damage to the inferior epigastric arteries or a direct tear of the rectus muscle. As far as we are aware this complication has not been reported after laparoscopic appendicectomy. PMID:21124654

  3. Thoracic empyema caused by Campylobacter rectus.

    PubMed

    Ogata, Tomoyuki; Urata, Teruo; Nemoto, Daisuke; Hitomi, Shigemi

    2017-03-01

    We report a case of thoracic empyema caused by Campylobacter rectus, an organism considered as a periodontal pathogen but rarely recovered from extraoral specimens. The patient fully recovered through drainage of purulent pleural fluid and administration of antibiotics. The present case illustrates that C. rectus can be a cause of not only periodontal disease but also pulmonary infection.

  4. Rectus muscle plication using an adjustable technique

    PubMed Central

    Velez, Federico G.; Demer, Joseph L.; Pihlblad, Matthew S.; Pineles, Stacy L.

    2013-01-01

    Background Rectus muscle plication is an alternative muscle-strengthening procedure to rectus muscle resection. Possible advantages of rectus muscle plication include a lower risk of “lost” muscles and anterior segment ischemia. Methods This was a retrospective case series describing a surgical procedure for rectus muscle plication using an adjustable suture technique that can be employed on any of the four rectus muscles. Results A total of 5 adult patients underwent adjustable suture plication procedures. Of these, 2 patients required suture adjustment postoperatively. At the final follow-up visit, all of the patients maintained satisfactory ocular alignment within 6Δ of orthotropia for horizontal deviations and 2Δ of orthotropia for vertical deviations. Diplopia was eliminated in all cases with preoperative diplopia. There were no postoperative complications or unexpected shifts in ocular alignment. Conclusions Rectus muscle plication using this adjustable suture technique may serve as an alternative to rectus muscle resection and may be particularly useful in patients who are at risk for anterior segment ischemia or those in whom a shorter anesthesia time is recommended. PMID:24160967

  5. Bimedial rectus hypermetabolism in convergence spasm as observed on positron emission tomography.

    PubMed

    Jeong, Seong-Hae; Oh, Young-Mi; Kim, Chae-Yong; Kim, Ji Soo

    2008-09-01

    A 52-year-old man developed vertical gaze palsy, convergence spasm, and convergence-retraction nystagmus due to glioblastoma of the right thalamus. 18F-fluorodeoxyglucose positron emission tomography (PET) inadvertently demonstrated markedly increased metabolism in the medial rectus muscles. The hypermetabolism indicates active contraction of these extraocular muscles due to excessive convergence drive attributed to inappropriate activation or disrupted inhibition of convergence neurons by the diencephalic lesion.

  6. Rectus sheath hematoma: three case reports

    PubMed Central

    Kapan, Selin; Turhan, Ahmet N; Alis, Halil; Kalayci, Mustafa U; Hatipoglu, Sinan; Yigitbas, Hakan; Aygun, Ersan

    2008-01-01

    Introduction Rectus sheath hematoma is an uncommon cause of acute abdominal pain. It is an accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear. It could occur spontaneously or after trauma. They are usually located infraumblically and often misdiagnosed as acute abdomen, inflammatory diseases or tumours of the abdomen. Case presentation We reported three cases of rectus sheath hematoma presenting with a mass in the abdomen and diagnosed by computerized tomography. The patients recovered uneventfully after bed rest, intravenous fluid replacement, blood transfusion and analgesic treatment. Conclusion Rectus sheath hematoma is a rarely seen pathology often misdiagnosed as acute abdomen that may lead to unnecessary laparotomies. Computerized tomography must be chosen for definitive diagnosis since ultrasonography is subject to error due to misinterpretation of the images. Main therapy is conservative management. PMID:18221529

  7. Rectus abdominis muscle strains in tennis players

    PubMed Central

    Maquirriain, Javier; Ghisi, Juan P; Kokalj, Antonio M

    2007-01-01

    Rectus abdominis muscle strains are common and debilitating injuries among competitive tennis players. Eccentric overload, followed by forced contraction of the non‐dominant rectus abdominis during the cocking phase of the service motion is the accepted injury mechanism. A tennis‐specific rehabilitation program emphasising eccentrics and plyometric strengthening of the abdominal wall muscles, contributes to the complete functional recovery in tennis players, and could help reduce recurrences. PMID:17957025

  8. Rectus abdominis muscle strains in tennis players.

    PubMed

    Maquirriain, Javier; Ghisi, Juan P; Kokalj, Antonio M

    2007-11-01

    Rectus abdominis muscle strains are common and debilitating injuries among competitive tennis players. Eccentric overload, followed by forced contraction of the non-dominant rectus abdominis during the cocking phase of the service motion is the accepted injury mechanism. A tennis-specific rehabilitation program emphasising eccentrics and plyometric strengthening of the abdominal wall muscles, contributes to the complete functional recovery in tennis players, and could help reduce recurrences.

  9. Large bimedial rectus recessions in congenital esotropia.

    PubMed Central

    Szmyd, S. M.; Nelson, L. B.; Calhoun, J. H.; Spratt, C.

    1985-01-01

    The success rate of large (6 and 7 mm) bimedial rectus recessions in 45 congenital esotropes with deviations of 50 prism dioptres or greater was found to be 91%. Judgment of final alignment was made six weeks postoperatively, with an average follow-up of 13 months. Large bimedial rectus recessions are an effective surgical treatment for congenital esotropia. This procedure does not significantly alter adduction, and leaves other muscles available should further surgery be necessary. These findings show that initial surgery on three or more muscles is unnecessary in congenital esotropia. PMID:3994944

  10. Rectus Abdominis Endometrioma after Caesarean Section

    PubMed Central

    Mishina, Anna; Zaharia, Sergiu; Zastavnitsky, Gheorghe

    2016-01-01

    Isolated rectus abdominis muscle endometriosis is very uncommon with less than 20 case reports being published to date since its first description in 1984 by Amato and Levitt. We report another case of isolated rectus abdominis endometriosis in a 37-year-old patient with a previous caesarian section. We also discuss the diagnostic and treatment particularities in these patients. In our case, the treatment was only surgical and currently the patient is disease-free during the 24-month follow-up. PMID:27999704

  11. Weak action potential backpropagation is associated with high-frequency axonal firing capability in principal neurons of the gerbil medial superior olive.

    PubMed

    Scott, Luisa L; Hage, Travis A; Golding, Nace L

    2007-09-01

    Principal neurons of the medial superior olive (MSO) convey azimuthal sound localization cues through modulation of their rate of action potential firing. Previous intracellular studies in vitro have shown that action potentials appear highly attenuated at the soma of MSO neurons, potentially reflecting specialized action potential initiation and/or a physically distant site of generation. To examine this more directly, we made dual patch-clamp recordings from MSO principal neurons in gerbil brainstem slices. Using somatic and dendritic whole-cell recordings, we show that graded action potentials at the soma are highly sensitive to the rate of rise of excitation and undergo strong attenuation in their backpropagation into the dendrites (length constant, 76 microm), particularly during strong dendritic excitation. Using paired somatic whole-cell and axonal loose-patch recordings, we show that action potentials recorded in the axon at distances > 25 microm are all-or-none, and uniform in amplitude even when action potentials appear graded at the soma. This proximal zone corresponded to the start of myelination in the axon, as assessed with immunocytochemical staining for myelin basic protein in single-labelled neurons. Finally, the axon was capable of sustaining remarkably high firing rates, with perfect entrainment occurring at frequencies of up to 1 kHz. Together, our findings show that action potential signalling in MSO principal neurons is highly secure, but shows a restricted invasion of the somatodendritic compartment of the cell. This restriction may be important for minimizing distortions in synaptic integration during the high frequencies of synaptic input encountered in the MSO.

  12. Herniated gyrus rectus causing idiopathic compression of the optic chiasm.

    PubMed

    Smith, Jacob; Jack, Megan M; Peterson, Jeremy C; Chamoun, Roukoz B

    2017-02-01

    Anomalies in the frontal lobe can interfere with visual function by compression of the optic chiasm and nerve. The gyrus rectus is located at the anterior cranial fossa floor superior to the intracranial optic nerves and chiasm. Compression of these structures by the gyrus rectus is often caused by neoplastic or dysplastic growth in the area. We report a rare case of a herniated gyrus rectus impinged on the optic chiasm and nerve without a clear pathological cause for the herniation.

  13. Rectus sheath haematoma: a rare masquerader for abdominal pain.

    PubMed

    Changal, Khalid Hamid; Saleem, Saad; Ghous, Ghulam

    2017-04-13

    Rectus sheath haematoma is a rare cause of abdominal pain. It can be easily confused for other causes of acute abdomen and may even lead to unnecessary laparotomies. Our patient has the rectus sheath haematoma because of violent coughing and on presentation had no obvious clinical sign pointing to the same. Diagnosis was made by a CT scan of the abdomen, and patient was treated conservatively. Rectus sheath haematomas are usually present on the posterior aspect of the rectus muscles and thus may not be clinically appreciable.

  14. Abdominal wall injuries: rectus abdominis strains, oblique strains, rectus sheath hematoma.

    PubMed

    Johnson, Rob

    2006-04-01

    Abdominal wall injuries are reported to be less common than actually perceived by sports medicine practitioners. National Collegiate Athletic Association injury statistics for 2004-2005 cite a high of 0.71 abdominal muscle injuries per 1000 player-hours in wrestling competition to a low of 0.01 injuries per 1000 player-hours in autumn football practices. British professional soccer clubs reported an incidence of "torso" injuries of up to 7% of all injuries over the course of several seasons. Injury definition is most likely the explanation for this discrepancy. The abdominal wall muscles (rectus abdominis, external and internal obliques, and transverse abdominis) are injured by direct blows to the abdomen or by sudden or repetitive trunk movement, either rotation or flexion/extension. With the exception of the rare rectus sheath hematoma that does not self-tamponade, the treatment for these problems is nonoperative with symptoms guiding rehabilitation and return to play decisions.

  15. Rectus sheath tunnels for continent stomas.

    PubMed

    Dickson, Alan P; Khalil, Basem A; Cervellione, Raimondo M

    2008-03-01

    Continent stoma rectus sheath tunnel (CSRST) has been used in antegrade colonic enema (ACE) and urinary continent cutaneous diversion (UCCD) stomas to reduce leakage and to support a straight track for the continent conduit. All patients that underwent CSRST between 1995 and 2005 were identified and their case notes retrospectively reviewed. Patients were divided into two groups: the ACE group and the UCCD group. Demographic data, age at surgery and complications including stenosis and leakage were recorded. Forty patients underwent CSRST between 1995 and 2005. The mean age and standard deviation (SD) at surgery was 6.8 (2.1) years. Eighteen patients underwent ACE with a mean (SD) follow-up of 7.6 (3.1) years. No patient has faecal leakage. No patient had stomal revision, but one patient (5.5%) required an indwelling gastrostomy button to maintain patency. Twenty-two patients underwent UCCD with a mean (SD) follow-up of 8.1 (2.8) years. No patient developed urinary leakage. Two patients (9%) required revision of the stoma and one (4.5%) required an indwelling catheter because of recurring stomal stenosis. CSRST prevents stoma leakage. Revision surgery rate after CSRST is low, particularly after ACE reconstruction.

  16. Medial epicondylitis - golfer's elbow

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/007638.htm Medial epicondylitis - golfer's elbow To use the sharing features on this page, please enable JavaScript. Medial epicondylitis is soreness or pain on the inside of ...

  17. Proximal Rectus Femoris Avulsion: Ultrasonic Diagnosis and Nonoperative Management

    PubMed Central

    Esser, Stephan; Jantz, David; Hurdle, Mark F.; Taylor, Walter

    2015-01-01

    Objective To present a case of ultrasonic diagnosis and nonoperative management of a complete proximal rectus femoris avulsion in a National Collegiate Athletic Association Division 1 soccer goalkeeper. Background While delivering a goal kick, a previously uninjured 24-year-old collegiate soccer goalkeeper had the sudden onset of right anterior thigh pain. He underwent rehabilitation with rapid resolution of his presenting pain but frequent intermittent recurrence of anterior thigh pain. After he was provided a definitive diagnosis with musculoskeletal ultrasound, he underwent an extended period of rehabilitation and eventually experienced complete recovery without recurrence. Differential Diagnosis Rectus femoris avulsion, rectus femoris strain or partial tear, inguinal hernia, or acetabular labral tear. Treatment Operative and nonoperative options were discussed. In view of the player's recovery, nonoperative options were pursued with a good result. Uniqueness Complete proximal rectus femoris avulsions are rare. Our case contributes to the debate on whether elite-level kicking and running athletes can return to full on-field performance without surgery. Conclusions Complete proximal rectus femoris avulsions can be treated effectively using nonoperative measures with good preservation of function even in the elite-level athlete. In addition, musculoskeletal ultrasound is an excellent tool for on-site evaluation and may help guide prognosis and management. PMID:25978099

  18. Dengue Fever with rectus sheath hematoma: a case report.

    PubMed

    Sharma, Anurag; Bhatia, Sonia; Singh, Rajendra Pratap; Malik, Gaurav

    2014-04-01

    Dengue fever, also known as breakbone fever, is an infectious tropical disease caused by the Dengue virus. It is associated with a number of complications, which are well documented. However, Dengue fever associated with rectus sheath hematoma (RSH) is a very rare complication. Only one case report has been published prior supporting the association of Dengue fever with RSH. We report a case of Dengue fever who presented with RSH and was successfully treated conservatively. RSH is also an uncommon cause of acute abdominal pain. It is accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear.

  19. Intractable pain due to rectus abdominis intramuscular haemangioma.

    PubMed

    Scozzari, G; Reddavid, R; Conti, L; Trombetta, F; Toppino, M; Sandrucci, S

    2014-08-01

    Haemangiomas are tumours of vascular origin accounting for approximately 7 % of all benign tumours. Three types of haemangioma have been described according to the vessel type involved: capillary, cavernous and mixed. Intramuscular haemangiomas (IMHs) are infrequent, accounting for less than 1 % of all haemangiomas and are mostly located in the extremities and the trunk. Intramuscular haemangiomas of the rectus abdominis muscle are extremely rare, with only one previous case reported in the literature to the best of our knowledge. In this report, we present the case of a patient with intractable pain related to IMHs of the rectus abdominis and we analyse diagnostic assessment and surgical management of the condition.

  20. Rectus sheath hematoma: a complication of laparoscopic cholecystectomy.

    PubMed

    Neufeld, D; Jessel, J; Freund, U

    1992-12-01

    We describe a complication in laparoscopic cholecystectomy. The routine introduction of a midclavicular secondary trocar resulted in a large hematoma of the rectus sheath. The patient developed atelectasis and pneumonia and required extended hospitalization. This previously described complication is detailed with recommendations to prevent its occurrence.

  1. Traumatic longitudinal splitting of the inferior rectus muscle

    PubMed Central

    Laursen, Jessica; Demer, Joseph L.

    2011-01-01

    Orbital floor fractures and associated injuries can cause strabismus. We present the case of a 34-year-old man with incomitant strabismus following orbital reconstruction after a high-impact baseball injury. Multipositional, high-resolution magnetic resonance imaging (MRI) revealed extensive longitudinal splitting of the inferior rectus muscle by an orbital floor implant that separated its orbital and global layers. PMID:21463958

  2. Medial Collateral Ligament (MCL) Injuries

    MedlinePlus

    ... of Healthy Breakfasts Shyness Medial Collateral Ligament (MCL) Injuries KidsHealth > For Teens > Medial Collateral Ligament (MCL) Injuries ... Treatment Coping With an MCL Injury About MCL Injuries A torn medial collateral ligament (MCL) is a ...

  3. Acute Calcific Tendinitis of the Rectus Femoris: A Case Series

    PubMed Central

    Kobayashi, Hideo; Kaneko, Haruka; Homma, Yasuhiro; Baba, Tomonori; Kaneko, Kazuo

    2015-01-01

    Introduction: Periarticular calcific tendinitis is a common cause of Orthopedic outpatient referral. Calcific tendinitis of the rectus femoris, however, is very rare and not well known. Due to its rarity, correct diagnosis and prompt treatment are not fully understood. Case Report: Two females (38 and 40 years old) of acute calcific tendinitis of the rectus femoris with the good clinical course without any operative treatment were presented. The pain was managed with oral non-steroidal antiinflammatory drugs and/or local steroid injection. Interval radiographic assessment showed complete resorption of the calcification. Conclusion: Establishing the correct diagnosis and initiating prompt treatment are shown to be important in achieving resolution of symptoms and in avoiding unnecessary investigations. PMID:27299063

  4. Surgical Management of Rectus Femoris Avulsion Among Professional Soccer Players

    PubMed Central

    Sonnery-Cottet, Bertrand; Barbosa, Nuno Camelo; Tuteja, Sanesh; Gardon, Roland; Daggett, Matt; Monnot, Damien; Kajetanek, Charles; Thaunat, Mathieu

    2017-01-01

    Background: Rectus femoris injuries are common among athletes, especially in kicking sports such as soccer; however, proximal rectus femoris avulsions in athletes are a relatively rare entity. Purpose/Hypothesis: The purpose of this study was to describe and report the results of an original technique of surgical excision of the proximal tendon remnant followed by a muscular suture repair. Our hypothesis was that this technique limits the risk of recurrence in high-level athletes and allows for rapid recovery without loss of quadriceps strength. Study Design: Case series; Level of evidence, 4. Methods: Our retrospective series included 5 players aged 31.8 ± 3.9 years with acute proximal rectus femoris avulsion injuries who underwent a surgical resection of the proximal tendon between March 2012 and June 2014. Four of these players had recurrent rectus femoris injuries in the 9 months before surgery, while 1 player had surgery after a first injury. Mean follow-up was 18.2 ± 12.6 months, and minimum follow-up was 9 months. We analyzed the age, sex distribution, physical examination outcomes, type and mechanism of injury, diagnosis, treatment and complications during surgery, postoperative follow-up, and time to return to play. The Lower Extremity Functional Scale (LEFS) and Marx scores were obtained at 3-month follow-up, and isokinetic tests were performed before return to sports. A telephone interview was completed to determine the presence of recurrence at an average follow-up of 18.2 months. Results: At 3-month follow-up, all patients had Marx activity scores of 16 and LEFS scores of 80. Return to the previous level of play occurred at a mean of 15.8 ± 2.6 weeks after surgery, and none of the athletes suffered a recurrence. Isokinetic test results were comparable between both sides. Conclusion: The surgical treatment of proximal rectus femoris avulsions, consisting of resection of the tendinous part of the muscle, is a reliable and safe technique allowing a

  5. Chuave Medial Verbs

    ERIC Educational Resources Information Center

    Thurman, Robert C.

    1975-01-01

    This article discusses two syntactic processes known as chaining and linkage, insofar as they are relevant to Chuave, a Papuan language spoken in the East New Guinea Highlands. These processes are discussed in relation to Chuave medial verbs. (CLK)

  6. Rectus abdominis muscle free flap harvest by laparoscopic sheath-sparing technique.

    PubMed

    Greensmith, A; Januszkiewicz, J; Poole, G

    2000-04-01

    Previous reports of endoscopic rectus abdominis muscle harvest have described techniques that are hampered by the need for anterior rectus sheath division or mechanical devices to maintain the optical cavity. The authors report the first successful clinical case of a laparoscopic sheath-sparing rectus abdominis muscle harvest for free tissue transfer. It offers considerable advantages over the traditional open method and, with the help of an experienced laparoscopic surgeon, it should add little to operative time.

  7. Architecture of the rectus abdominis, quadratus lumborum, and erector spinae.

    PubMed

    Delp, S L; Suryanarayanan, S; Murray, W M; Uhlir, J; Triolo, R J

    2001-03-01

    Quantitative descriptions of muscle architecture are needed to characterize the force-generating capabilities of muscles. This study reports the architecture of three major trunk muscles: the rectus abdominis, quadratus lumborum, and three columns of the erector spinae (spinalis thoracis, longissimus thoracis and iliocostalis lumborum). Musculotendon lengths, muscle lengths, fascicle lengths, sarcomere lengths, pennation angles, and muscle masses were measured in five cadavers. Optimal fascicle lengths (the fascicle length at which the muscle generates maximum force) and physiologic cross-sectional areas (the ratio of muscle volume to optimal fascicle length) were computed from these measurements. The rectus abdominis had the longest fascicles of the muscles studied, with a mean (S.D.) optimal fascicle length of 28.3 (4.2)cm. The three columns of the erector spinae had mean optimal fascicle lengths that ranged from 6.4 (0.6)cm in the spinalis thoracis to 14.2 (2.1)cm in the iliocostalis lumborum. The proximal portion of the quadratus lumborum had a mean optimal fascicle length of 8.5 (1.5)cm and the distal segment of this muscle had a mean optimal fascicle length of 5.6 (0.9)cm. The physiologic cross-sectional area of the rectus abdominis was 2.6 (0.9)cm(2), the combined physiologic cross-sectional area of the erector spinae was 11.6 (1.8)cm(2), and the physiologic cross-sectional area of the quadratus lumborum was 2.8 (0.5)cm(2). These data provide the basis for estimation of the force-generating potential of these muscles.

  8. Retracted: Spontaneous rectus sheath haematoma associated with rivaroxaban treatment.

    PubMed

    Tas Tuna, A; Palabiyik, O; Beyaz, S G

    2015-08-01

    http://onlinelibrary.wiley.com/doi/10.1111/jcpt.12228/pdf The above article, published online on 10 November 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, A. Li Wan Po, and John Wiley & Sons Ltd. The retraction has been agreed because, unknown to the authors, another group published a similar study based on the same material in the Indian Journal of Pharmacology: Kocayigit I, Can Y, Sahinkus S, et al. Spontaneous rectus sheath haematoma during rivaroxaban therapy. Indian Journal of Pharmacology. 2014;46(3):339-340. doi:10.4103/0253-7613.132193.

  9. Correction of Excyclotropia by Surgery on the Inferior Rectus Muscle in Patients with Thyroid Eye Disease: A Retrospective, Observational Study

    PubMed Central

    Takahashi, Yasuhiro; Kitaguchi, Yoshiyuki; Nakakura, Shunsuke; Mito, Hidenori; Kimura, Akiko; Kakizaki, Hirohiko

    2016-01-01

    Purpose To examine the characteristics of excyclotropia correction through surgery on the inferior rectus muscle in patients with thyroid eye disease. Methods This was a retrospective, observational study at a single institution. We reviewed 36 patients who had undergone unilateral inferior rectus muscle recession, with or without nasal inferior rectus muscle transposition. The following factors were investigated as possibly influencing excyclotropia correction: inferior rectus muscle thickness, degree of adipose change in the inferior rectus muscle, smoking status, history of orbital radiotherapy, and the amount of inferior rectus muscle recession. Using T1-weighted coronal magnetic resonance imaging, we measured the cross-sectional area of the inferior rectus muscle at its largest point, as well as the bright-signal area of the inferior rectus muscle, which reflects intermuscular adipose change. We then calculated the percentage internal bright-signal area at the point of the largest inferior rectus muscle cross-sectional area. The history of orbital radiotherapy was graded using a binary system. We evaluated correlations among excyclotropia correction, the amount of nasal inferior rectus muscle transposition, and the possible influencing factors listed, using stepwise multiple regression analyses. Results The multiple regression model demonstrated a significant relationship among excyclotropia correction, amount of nasal inferior rectus muscle transposition, and the amount of inferior rectus muscle recession (YCORRECTION = 8.546XTENDON WIDTH + 0.405XRECESSION− 0.908; r = 0.844; adjusted r2 = 0.695; P < 0.001). Conclusions Excyclotropia correction was correlated with the amount of nasal inferior rectus muscle transposition and the amount of inferior rectus muscle recession, but not with the other factors. The regression model presented in this study will enable us to determine more precisely the amount of nasal inferior rectus muscle transposition in patients

  10. Medial plica syndrome.

    PubMed

    Sznajderman, Tal; Smorgick, Yossi; Lindner, Dror; Beer, Yiftah; Agar, Gabriel

    2009-01-01

    Synovial plicae are membranous inward folds of the synovial lining of the knee joint capsula. Such folds are regularly found in the human knee, but most are asymptomatic and of little clinical consequence. However, they can become symptomatic and cause knee pain. In this review, we will discuss medial plica syndrome. Medial plica irritation of the knee is a common source of anterior knee pain. The main complaint is an intermittent, dull, aching pain in the area medial to the patella above the joint line and in the supramedial patellar area. Pain increases with activity, especially when knee flexion and extension are required. Treatment includes physiotherapy, reducing activity, and rest. In cases that do not respond initially to an exercise program, corticosteroid injections and non-steroidal antiinflammatory medication are given. Results of conservative treatment seem to be more appropriate in young patients with a short duration of symptoms. If conservative treatment fails, surgical treatment using arthroscopy is appropriate. During arthroscopy, excision of the whole plica should be achieved.

  11. Bedside Ultrasound Measurement of Rectus Femoris: A Tutorial for the Nutrition Support Clinician

    PubMed Central

    Monares Zepeda, Enrique; Lescas Méndez, Octavio Augusto

    2017-01-01

    Intensive care unit acquired weakness is a long-term consequence after critical illness; it has been related to muscle atrophy and can be considered as one of the main nutritional support challenges at the intensive care unit. Measuring muscle mass by image techniques has become a new area of research for the nutritional support field, extending our knowledge about muscle wasting and the impact of nutritional approaches in the critical care setting, although currently there is no universally accepted technique to perform muscle measurements by ultrasound. Because of this, we present this tutorial for nutrition support clinicians, in order to understand and perform muscle measurements by this reliable, accessible, low-cost, and easy-to-use technique. Reviewing issues such as quadriceps muscle anatomy, correct technique (do's and don'ts), identification of structures, and measurement of the rectus femoris and vastus intermedius muscles helps to acquire the basic concepts of this technique and encouraging more research in this field. PMID:28386479

  12. Initial experience with the use of porcine acellular dermal matrix (Strattice) for abdominal wall reinforcement after transverse rectus abdominis myocutaneous flap breast reconstruction.

    PubMed

    Cicilioni, Orlando; Araujo, Gerson; Mimbs, Nancy; Cox, Matthew D

    2012-03-01

    Reestablishing anterior rectus fascial integrity remains a clinical challenge after transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction. The main concerns include herniation and bulging due to abdominal weakness. Mesh-assisted closure of the fascial defect has improved bulging and herniation rates but infection, extrusion, and encapsulation are serious concerns with mesh use. Biologic tissue matrices may overcome some of these mesh-related complications. The initial experience of using Strattice for fascial closure after TRAM flap procedure is described in this article. Strattice was in-lain and sutured between the anterior and posterior layers of the rectus fascia, at the rectus muscle donor site. The abdominal wall was closed with progressive tension sutures. Postoperative complications at the donor site were assessed. A total of 16 unilateral and 9 bilateral reconstructions were performed in 25 patients. Length of hospital stay was 2 to 3 days which is shorter than with mesh repair (typically 4-5 days). During a mean follow-up period of 14.0 months, complications occurred in 7 patients (28%): seroma formation (2), minor skin separation (2), superficial skin infection (2), and superficial wound dehiscence (1). Complications were not directly related to Strattice and all, except one (superficial skin infection), were resolved without surgical intervention. In all patients, routine abdominal functions were restored 4 months postoperatively. Strattice is a safe, alternative option to synthetic mesh for fascial repair following TRAM flap breast reconstruction. When used in conjunction with progressive tension suture closure of the abdominal wall, dynamic reconstruction of the abdominal wall with resumption of abdominal function is possible with Strattice.

  13. [Paragliding-associated bilateral partial rupture of the rectus femoris muscle].

    PubMed

    Schulze Bertelsbeck, D; Veelken, D

    2004-12-01

    Pain in the thigh or groin due to a rupture of the rectus femoris muscle is rather uncommon. We report on a patient with a bilateral rupture of the rectus femoris muscle that occurred due to a landing maneuver while para-gliding. The diagnosis was confirmed by ultrasound and MRI. Additionally, an old unilateral anterior cruciate ligament rupture was present. As a functional deficit of the quadriceps muscle could not be observed, a primarily conservative treatment seems to be appropriate.

  14. Rectus abdominis overuse injury in a tennis athlete treated with traumeel

    PubMed Central

    Natsis, Konstantinos; Lyrtzis, Christos; Papathanasiou, Efthymia; Anastasopoulos, Nikos

    2012-01-01

    Summary Background: Rectus abdominis injuries are common in tennis players at all levels of competition. Traumeel® injection can be used for treatment of muscle strains and hematomas. Case Report: A 21-year-old female tennis athlete was injured on the non-dominant rectus abdominis during the cocking phase of the service motion. She suffered from pain and tenderness. One week later, during a serve, she experienced severe pain on the contralateral side of her abdomen. Conservative treatment was performed by the team physician with rest, ice therapy and analgesics for 20 days, but she had recurrent injuries. The ultrasonography and MRI showed hematoma of the rectus abdominis muscle. She was treated with 2 injections of Traumeel® on the 2nd, 4th, 6th post-traumatic day and received 1 injection on the 10th post-traumatic day. She also modified her serve technique. On the fourth post-treatment week the athlete had pain-free function and both the MRI appearance and the size of rectus abdominal muscle were normal. She returned to her sport activities. There is no recurrence of her injury 2 years later. Conclusions: Rectus abdominis hematoma must be diagnosed early. Traumeel® injections are effective, safe and well-tolerated for the treatment of overuse injury of the rectus abdominis following strain. PMID:23569472

  15. Musculo-tendon length and lengthening velocity of rectus femoris in stiff knee gait.

    PubMed

    Jonkers, Ilse; Stewart, Caroline; Desloovere, Kaat; Molenaers, Guy; Spaepen, Arthur

    2006-02-01

    Inappropriate activity of M. rectus femoris (RF) during swing is believed to contribute to stiff knee gait in cerebral palsy. This study used musculoskeletal modeling techniques to analyze rectus femoris musculo-tendon (MT) length and lengthening velocity during stiff knee gait in 35 children with diplegic cerebral palsy (CP). Duncan Ely test scores were used to categorize the patients into four groups with increasing levels of rectus femoris spasticity. Knee kinematics confirmed a significant reduction and delay of maximal peak knee flexion during swing in the patient groups compared to reference values. Maximal musculo-tendon length of M. rectus femoris was reduced and occurred prematurely in swing. Musculo-tendon lengthening velocity was significantly reduced and the timing of the maximal lengthening velocity was shifted into stance phase. The present study demonstrates altered dynamic behavior of the M. rectus femoris in stiff knee gait and the results indicate that maximal knee flexion in swing was not a valid reference for the MT length of the M. rectus femoris. Furthermore, in the patient group maximal musculo-tendon lengthening velocity of the muscle related to the stance phase rather than the stance-swing transition.

  16. Rectus femoris transfer and musculo-skeletal modeling: effect of surgical treatment on gait and on rectus femoris kinematics.

    PubMed

    Desailly, Eric; Khouri, Nejib; Sardain, Philippe; Yepremian, Daniel; Lacouture, Patrick

    2011-10-01

    Spasticity of the rectus femoris (RF) is one of the possible causes of stiff knee gait (SKG) in cerebral palsy. Musculoskeletal studies have shown that in SKG, length and speed of the RF are affected. No evaluation had been made to quantify the modifications of those parameters after surgery. The effect of this operation on gait quality and on RF kinematics was assessed in this study in order to identify kinematic patterns that may aid its diagnosis. For 26 transfers, clinical gait analysis pre- and post-surgery was used to compute the Gait Deviation Index (GDI) and Goldberg's index. The kinematics of the Original RF path (ORFp) was studied before and after surgery. The expression ORFp was chosen to avoid any confusion between this modeling parameter, whose computation was unchanged, and the actual anatomical path that was modified by surgery. The gait quality was improved (+18±12GDI) and there was an inverse relation between the pre-operative GDI and its improvement. The Golberg's index was improved (88% of the cases). The operation had a significant effect on the normalization of the timings of maximum length and speed of the ORFp. The improvement of SKG was correlated with the normalization of the timing of the ORFp's maximum length. The global improvement of the gait quality and of the SKG was demonstrated. Some parameters of muscular kinematics (RF length and velocity) have been standardized, showing an effect of the transfer not only during the swing, but also during stance. The premature timing of the ORFp peak length has been identified as a prognostic factor of a successful surgical outcome.

  17. Cloning and Characterization of Two Bistructural S-Layer-RTX Proteins from Campylobacter rectus

    PubMed Central

    Braun, Martin; Kuhnert, Peter; Nicolet, Jacques; Burnens, André P.; Frey, Joachim

    1999-01-01

    Campylobacter rectus is an important periodontal pathogen in humans. A surface-layer (S-layer) protein and a cytotoxic activity have been characterized and are thought to be its major virulence factors. The cytotoxic activity was suggested to be due to a pore-forming protein toxin belonging to the RTX (repeats in the structural toxins) family. In the present work, two closely related genes, csxA and csxB (for C. rectus S-layer and RTX protein) were cloned from C. rectus and characterized. The Csx proteins appear to be bifunctional and possess two structurally different domains. The N-terminal part shows similarity with S-layer protein, especially SapA and SapB of C. fetus and Crs of C. rectus. The C-terminal part comprising most of CsxA and CsxB is a domain with 48 and 59 glycine-rich canonical nonapeptide repeats, respectively, arranged in three blocks. Purified recombinant Csx peptides bind Ca2+. These are characteristic traits of RTX toxin proteins. The S-layer and RTX domains of Csx are separated by a proline-rich stretch of 48 amino acids. All C. rectus isolates studied contained copies of either the csxA or csxB gene or both; csx genes were absent from all other Campylobacter and Helicobacter species examined. Serum of a patient with acute gingivitis showed a strong reaction to recombinant Csx protein on immunoblots. PMID:10198015

  18. Cloning and characterization of two bistructural S-layer-RTX proteins from Campylobacter rectus.

    PubMed

    Braun, M; Kuhnert, P; Nicolet, J; Burnens, A P; Frey, J

    1999-04-01

    Campylobacter rectus is an important periodontal pathogen in humans. A surface-layer (S-layer) protein and a cytotoxic activity have been characterized and are thought to be its major virulence factors. The cytotoxic activity was suggested to be due to a pore-forming protein toxin belonging to the RTX (repeats in the structural toxins) family. In the present work, two closely related genes, csxA and csxB (for C. rectus S-layer and RTX protein) were cloned from C. rectus and characterized. The Csx proteins appear to be bifunctional and possess two structurally different domains. The N-terminal part shows similarity with S-layer protein, especially SapA and SapB of C. fetus and Crs of C. rectus. The C-terminal part comprising most of CsxA and CsxB is a domain with 48 and 59 glycine-rich canonical nonapeptide repeats, respectively, arranged in three blocks. Purified recombinant Csx peptides bind Ca2+. These are characteristic traits of RTX toxin proteins. The S-layer and RTX domains of Csx are separated by a proline-rich stretch of 48 amino acids. All C. rectus isolates studied contained copies of either the csxA or csxB gene or both; csx genes were absent from all other Campylobacter and Helicobacter species examined. Serum of a patient with acute gingivitis showed a strong reaction to recombinant Csx protein on immunoblots.

  19. A novel method of minimally invasive rectus abdominis muscle flap harvest: Laparoscopic surgeons take note

    PubMed Central

    Aijaz, Tabish; Singhal, Dhruv; Tan, Sanda A.; Iqbal, Atif

    2017-01-01

    The rectus abdominis muscle (RAM) is a workhorse flap to fill or repair abdominal defects. A drawback of an open RAM harvest is donor site morbidity, and minimally invasive techniques for flap harvesting have been previously proposed but involve vertical division of the rectus fascia. We present a case of a 52-year-old woman with a recurrent rectovaginal fistula in a radiated field treated with a laparoscopic low anterior resection with simultaneous RAM flap harvest utilising a single Pfannenstiel incision. Our novel modified laparoscopic-assisted RAM harvest technique prevents longitudinal violation of the anterior and posterior rectus sheaths, thereby promoting a quick recovery, improved cosmesis and decreased post-operative morbidity. PMID:28281481

  20. Medial Patellofemoral Ligament Reconstruction

    PubMed Central

    Palacios, Jose Antonio; Yacuzzi, Carlos; Oñativia, Jose I.; Zicaro, Juan Pablo; Costa-Paz, Matias

    2017-01-01

    Objectives: Recurrent patellofemoral dislocation is usually a multifactorial pathology. Different surgical techniques have been described according to the etiology of dislocation. In absence of a severe malalignment or an anatomical patellofemoral dysplasia, reconstruction of Medial Patello-femoral Ligament (MPFL) can restore the normal tracking of the patella, avoiding lateral excursion. The purpose of this study was to evaluate clinical results and complications in patients who underwent a MPFL reconstruction. Methods: We retrospectively evaluated 19 patients who underwent an anatomic MPFL reconstruction using autologous semitendinosus graft between 2007 and 2012. Exclusion criteria were patients with less than three years of follow-up and those with an associated procedure such as distal realignment or trochleoplasty. Clinical outcomes were measured using Kujala score and return to sport rate. We registered the postoperative complications and recurrence rate. Results: Nine patients were men and 10 women with a mean age of 25 years. Average follow-up was 5.8 years. Nine patients (47.4%) returned to their previous sport level, 8 (42.1%) changed to another sport or decreased their level and 2 (10.5%) were unable to practice any sports at all. Kujala score improvement was from 62.8 preoperative to 88.8 postoperative. One patient decreased the Kujala score. Eighty-nine percent of patients were satisfied with their outcome. One patient had a patellar fracture and four developed an arthrofibrosis and required mobilization under anesthesia. No recurrences were registered. Conclusion: Isolated MPFL reconstruction for recurrent patellofemoral dislocation is an effective alternative in absence of severe malalignment or anatomical dysplasia. Although no recurrences where registered at minimum 3-year follow-up, almost half of the patients were not able to return to their previous sport level.

  1. Giant pseudocyst of the rectus femoris muscle--repetitive strain injury in recreational soccer player.

    PubMed

    Cicvarić, Tedi; Lucin, Ksenija; Roth, Sandor; Ivancić, Aldo; Marinović, Marin; Santić, Veljko

    2010-04-01

    We report a case of a traumatic pseudocyst, in a recreational soccer player, after rupture of rectus femoris muscle. 37-year-old male, with history of repetitive painful accidents, was examined because of a double fist-sized mass in the anterior thigh. Ultrasound examination revealed a cystic mass in the rectus femoris muscle. Surgical removal of the mass and proximal remnant of muscle was done. Primary healing and functional recovery was achieved. Histological analysis revealed pseudocyst filled with degenerating clot and surrounded with thick fibrous capsule. The repetitive strain muscle injury, with prolonged period of healing, can occur like pseudocyst.

  2. Acute calcific tendinitis of the rectus femoris associated with intraosseous involvement: a case report with serial CT and MRI findings.

    PubMed

    Kim, Young Sung; Lee, Ho Min; Kim, Jong Pil

    2013-11-01

    Acute calcific tendinitis of the shoulder is a well-known condition, but it is rare in the rectus femoris origin. Mostly reported cases were occurred in the reflected head of the rectus femoris, and only few cases were in the direct head of the rectus femoris. Intraosseous marrow involvement of calcific tendinitis is a more rare condition; it often goes misdiagnosed as an infection or a neoplasm. We report a rare, unusual case of acute calcific tendinitis of the direct head of the rectus femoris associated with intraosseous marrow involvement of calcification in anterior inferior iliac spine with serial CT and MRI findings. Aggressive osseous change may occur in acute calcific tendinitis of the rectus femoris as in this case which should be made an appropriate diagnosis to avoid unnecessary investigation and overtreatment like a surgery.

  3. Experimental definition of latissimus dorsi, gracilis, and rectus abdominus musculocutaneous flaps in the dog.

    PubMed

    Gregory, C R; Gourley, I M; Koblik, P D; Patz, J D

    1988-06-01

    Dissection and injection studies in canine cadavers and in anesthetized dogs were conducted to determine the feasibility of using the latissimus dorsi, gracilis, and rectus abdominus muscles as musculocutaneous free flaps. Lengths of vascular pedicles for the latissimus dorsi (2 +/- 0.8 cm), gracilis (1.8 +/- 0.8 cm), and rectus abdominus (1.9 +/- 0.9-cm cranial deep epigastric, 1.7 +/- 0.5-cm caudal deep epigastric), as well as arterial diameters (1.28 +/- 0.31-mm thoracodorsal for the latissimus dorsi, 1.10 +/- 0.33-mm muscular branch for the gracilis, 1.25 +/- 0.25-mm cranial deep epigastric and 1.26 +/- 0.32-mm caudal deep epigastric for the rectus abdominus) were considered satisfactory for microvascular transfer. Fluorometry demonstrated overlying cutaneous perfusion in all flaps based on their muscle vascular pedicles, with the exception of the rectus abdominus flap based on the caudal deep epigastric artery. In this instance, up to 20% of the cutaneous element had questionable or no perfusion.

  4. Rabbit rectus femoris muscle for ischemia-reperfusion studies: an improved model.

    PubMed

    Hoballah, J J; Mohan, C R; Schipper, P H; Chalmers, R T; Corry, D C; Corson, J D

    1996-11-01

    The rabbit rectus femoris muscle was evaluated as a potential model for skeletal muscle reperfusion injury studies. Six white New Zealand rabbits were used. On one randomly selected hind limb, ischemia was induced by direct clamping of the rectus femoris muscle's vascular pedicle. On the other side, blood flow was interrupted by clamping the femoral artery above and below the origin of the vascular pedicle that supplies the rectus femoris muscle. The duration of normothermic ischemia was 4 hr and was followed by 24 hr of normothermic reperfusion. The interruption and restoration of blood flow was monitored using a laser flow meter. The rectus femoris muscles were weighed on a suspension spring balance prior to ischemia and at the end of reperfusion to estimate edema. The extent of muscle necrosis was determined using planimetry following staining with nitroblue tetrazolium. The muscle necrosis obtained by direct clamping of the vascular pedicle (66.9 +/- 14.3%) was significantly greater than that obtained by indirect clamping (18.6 +/- 11.4%) (P < 0.03 by t test). Unlike the indirect clamping technique, direct clamping achieved a good magnitude of muscle necrosis, thus allowing that specific model to be used in skeletal muscle reperfusion injury studies. The muscle weight gain observed in the direct clamping muscle group was 19.8 +/- 9.0% and was significantly greater than that observed in the opposite group being 6.3 +/- 6.5% (P < 0.05 by t test). The rabbit rectus femoris muscle is a suitable model for evaluating skeletal muscle reperfusion injury provided that direct clamping of the vascular pedicle is utilized.

  5. GRADED PARTIAL TENOTOMY OF VERTICAL RECTUS MUSCLES FOR TREATMENT OF HYPERTROPIA

    PubMed Central

    Yim, Hye Bin; Biglan, Albert W; Cronin, Tara H

    2004-01-01

    ABSTRACT Purpose To evaluate the effectiveness of graded (adjustable intraoperatively) partial vertical rectus muscle tenotomy at the insertion in correcting small degrees of hypertropia. Methods All patients with best-corrected visual acuity of better than 6/30 in both eyes who over a 30-month period underwent partial tenotomy of vertical rectus muscle(s) only (no concurrent oblique muscles) were included. Improvement was evaluated 6 weeks postoperatively as change in alignment in prism diopters (PD) in primary gaze and in the field of action of the affected rectus muscle(s). Binocular function was evaluated by Titmus stereoacuity and the Worth 4-light tests. Results All 24 patients who met criteria for inclusion had diplopia preoperatively versus seven patients (29%) postoperatively (P < .005, Student’s paired t test). Prisms were used by six preoperatively versus two postoperatively (P < .05, Student’s paired t test). The average vertical deviation in primary gaze decreased from 8 PD to 2 PD (P < .005, Student’s paired t test). In the field of action of the treated rectus muscle, hypertropia decreased from an average of 8 PD to 3 PD (P < .005, Student’s paired t test). For the preoperative and the postoperative assessments available, stereoacuity improved after 10 (56%) of the 18 procedures and Worth 4-light testing showed improvement or maintenance of fusion after 15 (79%) of 19 procedures. Conclusions Graded vertical rectus partial tenotomy can effectively reduce small degrees of hypertropia and associated diplopia, improve binocular function, and reduce or eliminate the need for prism correction. PMID:15747755

  6. Clinical anatomy and mechanical tensile properties of the rectus femoris tendon

    PubMed Central

    Zhu, Xing-Fei; Zhang, Xin-Chao

    2015-01-01

    Purpose: We aimed to provide anatomical data and mechanical tensile properties for the rectus femoris tendon to determine if it is a feasible substitute for the anterior cruciate ligament during knee joint reconstruction. Methods: The length and width of the quadriceps femoris tendon were measured from ten adult cadavers (20 knees; age =48±2 years). The anatomic features of the patellar insertion on the quadriceps femoris tendon were also documented. The rectus femoris tendon and anterior cruciate ligament were harvested from an additional five fresh specimens (10 knees; age =41±3 years). To minimize dehydration, each specimen was wrapped in saline-moistened paper towels and stored at -10°C. We imposed tensile stresses on a total of twenty samples in a sample-driven machine at 10 mm/min until the specimens failed. Results: The inserted and discrete widths of the rectus femoris tendon were 3.20±0.33 and 1.28±0.25 cm, respectively. The length of the tendon tissue was 6.96±0.80 cm and the length of mixing zone was 3.81±0.53 cm. The average thickness of the upper pole of the patella was 2.22±0.14 cm. In mechanical tensile properties, the unit modulus and unit maximum load of the rectus femoris tendon were both 63% of the anterior cruciate ligament. Conclusions: Based on its anatomical and mechanical tensile properties, the rectus femoris tendon is a feasible donor site to reconstitute the anterior cruciate ligament. PMID:26885205

  7. Donor-site Morbidity of Medial and Lateral Thigh-based Flaps: A Comparative Study

    PubMed Central

    Purnell, Chad A.; Lewis, Kevin C.; Mioton, Lauren M.; Hanwright, Philip J.; Galiano, Robert D.; Dumanian, Gregory A.; Alghoul, Mohammed S.

    2016-01-01

    Background: Free and pedicled medial and lateral thigh-based flaps are common reconstructive procedures. However, there have been no comparative studies of morbidity between medial and lateral donor sites. Methods: We conducted an Enterprise Data Warehouse-based review of all the senior authors’ (R.D.G., G.A.D., and M.S.A.) thigh-based free and pedicled flaps. Patient demographic data, donor-site complications, drain duration, and number of postoperative visits were collected and compared. Complications were also compared between fasciocutaneous flaps and muscle or myocutaneous flaps, and skin grafted donor sites. Results: We analyzed 352 flap donor sites, with 155 medial and 197 lateral. Two hundred seventeen (217) flaps were pedicled. Flap types included 127 gracilis, 27 rectus femoris, 134 anterolateral thigh, and 36 vastus lateralis-only flaps. There were no significant differences in complications between medial (17.4%) and lateral thigh (21.3%) donor sites, although lateral thigh flaps had a mean of 1 additional postoperative visit. Rates of wound dehiscence/healing issues were significantly higher in both gracilis myocutaneous flaps (25.9%) and flaps requiring a skin grafted donor site (31.2%). Postoperative therapeutic anticoagulation was the only significant risk factor for a donor-site complication. Flap complications resulted in increased drain duration and postoperative office visits. Conclusions: Donor-site morbidity is similar in both lateral and medial thigh-based flaps. The inclusion of muscle in the flap from either donor site does not seem to increase complications, but the inclusion of a skin paddle with gracilis muscle, or a skin grafted lateral thigh donor site, results in increased wound healing complications. PMID:27975004

  8. Weak Interactions

    DOE R&D Accomplishments Database

    Lee, T. D.

    1957-06-01

    Experimental results on the non-conservation of parity and charge conservation in weak interactions are reviewed. The two-component theory of the neutrino is discussed. Lepton reactions are examined under the assumption of the law of conservation of leptons and that the neutrino is described by a two- component theory. From the results of this examination, the universal Fermi interactions are analyzed. Although reactions involving the neutrino can be described, the same is not true of reactions which do not involve the lepton, as the discussion of the decay of K mesons and hyperons shows. The question of the invariance of time reversal is next examined. (J.S.R.)

  9. Patterns of attachment of the myodural bridge by the rectus capitis posterior minor muscle.

    PubMed

    Yuan, Xiao-Ying; Yu, Sheng-Bo; Li, Yun-Fei; Chi, Yan-Yan; Zheng, Nan; Gao, Hai-Bin; Luan, Bing-Yi; Zhang, Zhao-Xi; Sui, Hong-Jin

    2016-03-01

    The myodural bridge was first described by Hack in 1995 and was thought to be related to chronic cervicogenic headaches. For a long time, few studies revealed the patterns of the myodural bridge considering the rectus capitis posterior minor muscle. In this study, P45 plastination technology and anatomical dissection were performed on head specimens, and four different terminal region types of the rectus capitis posterior minor muscle were observed, including the posterior atlanto-occipital interspace, posterior arch of the atlas and posterior atlanto-axial interspace. We propose that the myodural complex structures in the posterior atlanto-occipital and posterior atlanto-axial interspace have cooperative effects on cerebrospinal fluid and work together. This force might be an important source for the circulation of cerebrospinal fluid.

  10. Successful Treatment of Rectus Femoris Calcification with Ultrasound-guided Injection: A Case Report

    PubMed Central

    Hong, Myong Joo; Park, Jeong Ki; Kang, Tai Ug

    2015-01-01

    Painful periarticular calcification most commonly occurs within the rotator cuff of the shoulder and rarely around the elbow, hip, foot, and neck. As acute inflammatory reaction develops, severe pain, exquisite tenderness, local swelling, and limitation of motion with pain occur. In case of calcific tendinitis of the shoulder, it can be easily diagnosed according to the symptoms and with x-ray. However, in lesions of the hip, as it is a rare location and usually involves pain in the posterolateral aspect of the thigh, which can simulate radicular pain from a lumbar intervertebral disc, it could be difficult to diagnose. Hence, physicians usually focus on lumbar lesions; therefore, misdiagnosis is common and leads to a delayed management. Here, we report the case of a 30-year-old female patient with calcific tendinitis of the rectus femoris that was successfully managed with ultrasound-guided steroid injection. This study offers knowledge about the rectus femoris calcification. PMID:25589947

  11. Proximal rectus femoris avulsion in an elite, olympic-level sprinter.

    PubMed

    Langer, Phillip R; Selesnick, Harlan

    2010-11-01

    Quadriceps injuries, ranging from simple strains to disabling muscle ruptures, are common athletic injuries. The rectus femoris is the most commonly injure portion of the quadriceps musculature. This article is, to our knowledge, the first report of a proximal rectus femoris avulsion in an elite, Olympic-level 100-meter sprinter, acutely managed with surgical repair. Several key factors must be considered and carefully assessed when determining the appropriate course of management (ie, deciding between operative and nonoperative treatment): amount of distal retraction of the tendon, severity of associated soft-tissue trauma, physical examination, and postoperative goals (eg, return to elite-level competitive sports involving running or kicking vs resuming basic activities of daily living). We believe that these factors in our elite, high-performance athlete dictated an operative course of management.

  12. Rectus femoris muscle injuries in football: a clinically relevant review of mechanisms of injury, risk factors and preventive strategies.

    PubMed

    Mendiguchia, Jurdan; Alentorn-Geli, Eduard; Idoate, Fernando; Myer, Gregory D

    2013-04-01

    Quadriceps muscle strains frequently occur in sports that require repetitive kicking and sprinting, and are common in football in its different forms around the world. This paper is a review of aetiology, mechanism of injury and the natural history of rectus femoris injury. Investigating the mechanism and risk factors for rectus femoris muscle injury aims to allow the development of a framework for future initiatives to prevent quadriceps injury in football players.

  13. Rectus abdominis muscle resection and fascial reconstruction for the treatment of uterine leiomyosarcoma invading the abdominal wall: a case report.

    PubMed

    Yoon, B S; Seong, S J; Song, T; Kim, M L; Kim, M K

    2014-01-01

    The authors present a case of intra-abdominal recurrent leiomyosarcoma invading a large area of the abdominal wall. The patient underwent cytoreductive surgery, including resection of the rectus abdominis muscle, followed by reconstruction of the defect using synthetic mesh. The tumor was surgically removed by en bloc resection, including most of the rectus abdominis muscle and ileum. The abdominal wall defect was repaired using synthetic mesh. The patient underwent radiotherapy and chemotherapy after the surgery and was healthy one year later.

  14. Muscle Weakness

    PubMed Central

    Al Kaissi, Ali; Ryabykh, Sergey; Ochirova, Polina; Kenis, Vladimir; Hofstätter, Jochen G.; Grill, Franz; Ganger, Rudolf; Kircher, Susanne Gerit

    2017-01-01

    Marked ligamentous hyperlaxity and muscle weakness/wasting associated with awkward gait are the main deficits confused with the diagnosis of myopathy. Seven children (6 boys and 1 girl with an average age of 8 years) were referred to our department because of diverse forms of skeletal abnormalities. No definitive diagnosis was made, and all underwent a series of sophisticated investigations in other institutes in favor of myopathy. We applied our methodology through the clinical and radiographic phenotypes followed by targeted genotypic confirmation. Three children (2 boys and 1 girl) were compatible with the diagnosis of progressive pseudorheumatoid chondrodysplasia. The genetic mutation was correlated with the WISP 3 gene actively expressed by articular chondrocytes and located on chromosome 6. Klinefelter syndrome was the diagnosis in 2 boys. Karyotyping confirmed 47,XXY (aneuploidy of Klinefelter syndrome). And 2 boys were finally diagnosed with Morquio syndrome (MPS type IV A) as both showed missense mutations in the N-acetylgalactosamine-sulfate sulfatase gene. Misdiagnosis can lead to the initiation of a long list of sophisticated investigations. PMID:28210640

  15. Large Asymmetric Hypertrophy of Rectus Abdominis Muscle in Professional Tennis Players

    PubMed Central

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Dorado, Cecilia; Alayón, Santiago; Calbet, Jose A. L.

    2010-01-01

    Purpose To determine the volume and degree of asymmetry of the musculus rectus abdominis (RA) in professional tennis players. Methods The volume of the RA was determined using magnetic resonance imaging (MRI) in 8 professional male tennis players and 6 non-active male control subjects. Results Tennis players had 58% greater RA volume than controls (P = 0.01), due to hypertrophy of both the dominant (34% greater volume, P = 0.02) and non-dominant (82% greater volume, P = 0.01) sides, after accounting for age, the length of the RA muscle and body mass index (BMI) as covariates. In tennis players, there was a marked asymmetry in the development of the RA, which volume was 35% greater in the non-dominant compared to the dominant side (P<0.001). In contrast, no side-to-side difference in RA volume was observed in the controls (P = 0.75). The degree of side-to-side asymmetry increased linearly from the first lumbar disc to the pubic symphysis (r = 0.97, P<0.001). Conclusions Professional tennis is associated with marked hypertrophy of the musculus rectus abdominis, which achieves a volume that is 58% greater than in non-active controls. Rectus abdominis hypertrophy is more marked in the non-dominant than in the dominant side, particularly in the more distal regions. Our study supports the concept that humans can differentially recruit both rectus abdominis but also the upper and lower regions of each muscle. It remains to be determined if this disequilibrium raises the risk of injury. PMID:21209832

  16. Lateral rectus myositis mimicking an abducens nerve palsy in a pregnant woman.

    PubMed

    Haslinda, Abd-Rahim; Shatriah, Ismail; Azhany, Yaakub; Nik-Ahmad-Zuky, Nik-Lah; Yunus, Rohaizan

    2014-01-01

    Myositis is a rare unknown inflammatory disorder of the skeletal muscle tissue. Generalized inflammatory myopathies, polymyositis, and dermatomyositis have been reported during pregnancy. Isolated orbital myositis in pregnancy has not been previously described in the literature. The authors report a case of left isolated orbital myositis in a primigravida at 38 weeks gestation affecting the patient's left lateral rectus muscle. MRI of the orbit was consistent with the diagnosis. She showed remarkable clinical improvement with oral corticosteroids therapy.

  17. Rectus abdominis muscle injuries in elite handball players: management and rehabilitation.

    PubMed

    Balius, Ramon; Pedret, Carles; Pacheco, Laura; Gutierrez, Josep Antoni; Vives, Joan; Escoda, Jaume

    2011-01-01

    Muscle injuries generally occur in two-joint muscles with a high percentage of type II fibers during the performance of eccentric activity. Some muscle injuries, such as those located in the adductor longus, a monoarticular muscle, as well as rectus abdominis do not fully comply with these requirements. This study examines five cases of elite handball players with ruptured rectus abdominals. Sonographically, lesions in rectus abdominis are shown as a disruption of the fibrillar pattern with a hematic suffusion that invades the entire lesion. In some of the cases, the ultrasound study was complemented with a MRI. A unified rehabilitation protocol was applied and the return to play time of each handball player ranged between 16 and 22 days, with an average of 18.2 days. Follow-up at 15 months showed no evidence of re-injury or residual discomfort and all of them are playing at their highest level. The aim of this study was to illustrate a feature of handball injury that, as in tennis and volleyball, is uncommon and so far has not been specifically reported. The phenomenon of contralateral abdominal hypertrophy in handball appears in the dominant arm as in tennis and volleyball.

  18. Rectus abdominis muscle injuries in elite handball players: management and rehabilitation

    PubMed Central

    Balius, Ramon; Pedret, Carles; Pacheco, Laura; Gutierrez, Josep Antoni; Vives, Joan; Escoda, Jaume

    2011-01-01

    Muscle injuries generally occur in two-joint muscles with a high percentage of type II fibers during the performance of eccentric activity. Some muscle injuries, such as those located in the adductor longus, a monoarticular muscle, as well as rectus abdominis do not fully comply with these requirements. This study examines five cases of elite handball players with ruptured rectus abdominals. Sonographically, lesions in rectus abdominis are shown as a disruption of the fibrillar pattern with a hematic suffusion that invades the entire lesion. In some of the cases, the ultrasound study was complemented with a MRI. A unified rehabilitation protocol was applied and the return to play time of each handball player ranged between 16 and 22 days, with an average of 18.2 days. Follow-up at 15 months showed no evidence of re-injury or residual discomfort and all of them are playing at their highest level. The aim of this study was to illustrate a feature of handball injury that, as in tennis and volleyball, is uncommon and so far has not been specifically reported. The phenomenon of contralateral abdominal hypertrophy in handball appears in the dominant arm as in tennis and volleyball. PMID:24198573

  19. Identification and Characterization of a Putative Chemotaxis Protein, CheY, from the Oral Pathogen Campylobacter rectus

    PubMed Central

    LaGier, Michael J.; Bilokopytov, Ihor; Cockerill, Bradley; Threadgill, Deborah S.

    2014-01-01

    Campylobacter rectus is an understudied oral bacterium that contributes to periodontitis. Processes that contribute to the disease-causing capabilities of pathogens, such as chemotaxis, are largely unknown in C. rectus. The aim of this study was to better understand C. rectus chemotaxis, by examining the C. rectus genome for the presence of a cheY gene. CheY proteins play a part in chemotaxis by acting as two-component response regulators. Significantly, CheY proteins from several pathogens, including the related species Campylobacter jejuni, have been shown to contribute to bacterial virulence. Degenerate PCR, RT-PCR, sequence analyses, and structural modeling showed that C. rectus encodes a gene (Cr-CheY) which shares significant homology with previously characterized CheY proteins. Functional studies of a recombinant form of the protein supports a likely role of Cr-CheY in C. rectus chemotaxis. Cr-CheY is the first CheY characterized from the oral campylobacters. PMID:25598863

  20. A new technique of closing a gastroatmospheric fistula with a rectus abdominis muscle flap

    PubMed Central

    Singh, Harjeet; Talukder, Shibojit; Verma, Ganga Ram

    2015-01-01

    Proximal enteroatmospheric fistulae are difficult to manage and carry high mortality from sepsis and electrolyte imbalances. Conservative management with total parenteral nutrition, exclusion of fistula, resection and anastomosis are conventional methods of treatment with low success rate. Providing muscle cover to manage an enteroatmospheric fistula is a noble concept. A postoperative high-output gastroatmospheric fistula (GAF) was repaired by superior epigastric artery-based rectus abdominis muscle flap (RAMF). Postoperative recovery was uneventful. This technique may be useful for closure of proximal enteroatmospheric fistulae that fail to heal through medical and conventional surgical management. PMID:25819831

  1. Scrub Typhus Presenting with Bilateral Lateral Rectus Palsy in A Female

    PubMed Central

    Mishra, Jaya; Barman, Bhupen; Mondal, Sumantro; Sivam, Rondeep Kumar Nath

    2016-01-01

    Scrub typhus, a rickettsial disease is endemic in several parts of India usually presenting with acute symptoms. Fever, maculopapular rash, eschar, history of tick exposure and supportive diagnostic tests usually leads to diagnosis. Scrub typhus should be included in the differential diagnosis in occasions when a patient presents with fever with or without eschar and isolated cranial nerve palsy. Here we are reporting a case of Scrub typhus who presented with fever and altered sensorium of short duration, eschar formation and bilateral lateral rectus palsy. Patient was treated with doxycycline with complete reversal of neurodeficit. PMID:27190871

  2. Dissociable contributions of the left and right posterior medial orbitofrontal cortex in motivational control of goal-directed behavior.

    PubMed

    Szatkowska, Iwona; Szymańska, Olga; Marchewka, Artur; Soluch, Paweł; Rymarczyk, Krystyna

    2011-09-01

    Several findings from both human neuroimaging and nonhuman primate studies suggest that the posterior medial orbitofrontal cortex (OFC) may be critical for the motivational control of goal-directed behavior. The present study was conducted to clarify the role of the left and right posterior medial OFC in that function by examining the effects of focal unilateral lesions to this region on the performance on an incentive working memory task. The study covered patients who had undergone surgery for an ACoA aneurysm and normal control subjects (C). The patients were subdivided into three groups: those with resection of the left (LGR+) or right (RGR+) posterior part of the gyrus rectus, and without such a resection (GR-). Participants performed a 2-back working memory task under three motivational conditions (penalty, reward, and no-incentive). The C group performed worse in the penalty condition and better in the reward condition as compared to the no-incentive condition. Similar results were obtained for the GR- group. Performance of the LGR+ group did not depend on incentive manipulations, whereas the RGR+ group performed better in both the penalty and reward conditions than in the no-incentive condition. The results show that the posterior medial OFC is involved in the motivational modulation of working memory performance. Our findings also suggest that the left posterior medial OFC plays a crucial role in this function, whereas the right posterior medial OFC is particularly involved in the processing of the punishing aspect of salient events and it probably mediates in guiding behavior on the basis of negative outcomes of action.

  3. Electromyographic activity of the rectus abdominis during a traditional crunch and the basic jackknife exercise with the Ab Lounge™.

    PubMed

    Nelson, Gail A; Bent-Forsythe, Denise A; Roopchand-Martin, Sharmella C

    2012-06-01

    The use of nontraditional exercise devices such as the Ab Lounge™ has been promoted as being as effective as the traditional abdominal crunch in strengthening the abdominal musculature. Evidence for this is lacking, however. The purpose of this study was to compare the degree of activation of the upper and lower rectus abdominis using electromyography (EMG) during a traditional crunch with the basic jackknife using the Ab Lounge™. Twenty-two subjects (6 men and 16 women) were randomly selected from the student population at the University of the West Indies (Mona Campus). The mean age of the participants was 20.5 ± 1.5 years, height 166.4 ± 6.2 cm, weight 64 ± 10.3 kg, and waist-hip ratio 0.7 ± 0.1. Surface EMG was used to assess the muscle activity from the upper and lower rectus abdominis while each exercise was performed. The EMG data were full-wave rectified and normalized using a mathematical model that was set up in Microsoft Excel for Windows XP. Statistical analysis was performed on the data using a univariate analysis of variance with gender as a covariate. Significance was determined by p < 0.05. The mean EMG data recorded for the upper rectus abdominis was significantly higher with the traditional crunch when compared with the basic jackknife performed on the Ab Lounge™ (F = 4.39, p = 0.04). The traditional crunch produced a higher level of activity in the lower rectus abdominis when compared with the basic jackknife, but this was not statistically significant (F = 0.249, p = 0.62). There was no significant interaction between gender and the effect of the type of exercise on upper and lower rectus abdominis activation. These results suggest that the traditional abdominal crunch is more effective than the basic jackknife is in activating the rectus abdominis musculature.

  4. Low-Grade Myxofibrosarcoma of the Rectus Abdominus Muscle Infiltrating into Abdominal Cavity: A Case Report

    PubMed Central

    Sakakibara, Shunsuke; Moriwaki, Aya; Kawamoto, Teruya; Suzuki, Satoshi; Ishimura, Takeshi; Hashikawa, Kazunobu; Terashi, Hiroto

    2017-01-01

    Objective: Myxofibrosarcoma (MFS) is a relatively rare tumor that is histologically characterized by myxoid stroma and spindle cell proliferation. This tumor most commonly arises as a slow growing, enlarging painless mass in the extremities of elderly patients. Methods: We report a case of a primary, low-grade MFS in the rectus abdominis muscle infiltrating the abdominal cavity of a 75-year-old man. Results: The patient underwent a wide excision of the right abdominal wall mass with a 3-cm surgical margin from the scar due to a biopsy. The tumor infiltrated the urinary bladder, peritoneum, and external iliac vessels. Twenty-six months after the initial operation, he had recurrences in his abdominal wall, urinary bladder, and right iliac vessels. Conclusions: To our knowledge, primary MFS of the muscle in the abdomen has not been documented previously. Although this case was histopathologically classified as a low-grade tumor, it infiltrated the abdominal cavity. The tumor is suspected to have penetrated the abdominal cavity below the linea arcuata, which lacks the posterior sheath of the rectus abdominis muscle; from there, it could easily spread without being blocked by any biological barriers. PMID:28293331

  5. Low-Grade Myxofibrosarcoma of the Rectus Abdominus Muscle Infiltrating into Abdominal Cavity: A Case Report.

    PubMed

    Nomura, Tadashi; Sakakibara, Shunsuke; Moriwaki, Aya; Kawamoto, Teruya; Suzuki, Satoshi; Ishimura, Takeshi; Hashikawa, Kazunobu; Terashi, Hiroto

    2017-01-01

    Objective: Myxofibrosarcoma (MFS) is a relatively rare tumor that is histologically characterized by myxoid stroma and spindle cell proliferation. This tumor most commonly arises as a slow growing, enlarging painless mass in the extremities of elderly patients. Methods: We report a case of a primary, low-grade MFS in the rectus abdominis muscle infiltrating the abdominal cavity of a 75-year-old man. Results: The patient underwent a wide excision of the right abdominal wall mass with a 3-cm surgical margin from the scar due to a biopsy. The tumor infiltrated the urinary bladder, peritoneum, and external iliac vessels. Twenty-six months after the initial operation, he had recurrences in his abdominal wall, urinary bladder, and right iliac vessels. Conclusions: To our knowledge, primary MFS of the muscle in the abdomen has not been documented previously. Although this case was histopathologically classified as a low-grade tumor, it infiltrated the abdominal cavity. The tumor is suspected to have penetrated the abdominal cavity below the linea arcuata, which lacks the posterior sheath of the rectus abdominis muscle; from there, it could easily spread without being blocked by any biological barriers.

  6. The S-layer protein from Campylobacter rectus: sequence determination and function of the recombinant protein.

    PubMed

    Miyamoto, M; Maeda, H; Kitanaka, M; Kokeguchi, S; Takashiba, S; Murayama, Y

    1998-09-15

    The gene encoding the crystalline surface layer (S-layer) protein from Campylobacter rectus, designated slp, was sequenced and the recombinant gene product was expressed in Escherichia coli. The gene consisted of 4086 nucleotides encoding a protein with 1361 amino acids. The N-terminal amino acid sequence revealed that Slp did not contain a signal sequence, but that the initial methionine residue was processed. The deduced amino acid sequence displayed some common characteristic features of S-layer proteins previously reported. A homology search showed a high similarity to the Campylobacter fetus S-layer proteins, especially in their N-terminus. The C-terminal third of Slp exhibited homology with the RTX toxins from Gram-negative bacteria via the region including the glycine-rich repeats. The Slp protein had the same N-terminal sequence as a 104-kDa cytotoxin isolated from the culture supernatants of C. rectus. However, neither native nor recombinant Slp showed cytotoxicity against HL-60 cells or human peripheral white blood cells. These data support the idea that the N-terminus acts as an anchor to the cell surface components and that the C-terminus is involved in the assembly and/or transport of the protein.

  7. Relation between serum ischemia-modified albumin levels and rectus abdominis muscle flap viability.

    PubMed

    Livaoğlu, Murat; Arvas, Leyla; Karaçal, Naci; Menteşe, Ahmet; Karahan, S Caner; Sözen, Emrah

    2011-05-01

    Ischemia is a major cause of flap failure in reconstructive surgery. To detect circulatory compromise, many flap monitoring methods are used; however, there is no any optimal standard method. Ischemia-modified albumin (IMA) is an ischemia marker, which has recently been investigated in many studies and largely validated for early detection of ischemia. In this study, we investigated possible relationship between muscle flap viability and serum IMA levels in experimental flap model. The rectus abdominis muscle flap model was used in 18 New Zealand white rabbits. The study was planned using 3 groups. In group 1, the rectus abdominis muscle flap was harvested as a superior pedicle-based flap in which the inferior pedicle was sacrificed. In group 2, the flap was harvested by severing the superior pedicle. Both pedicles were harvested in group 3. Serum IMA levels were measured before the procedure and 1 hour, 6 hours, and 7 days postoperatively and then compared. In group 3, in which the ischemia was evident, and in group 1, IMA levels were significantly high 1 hour postoperatively (P < 0.05). There was no other significant difference in any of the other studied parameters between the groups. In conclusion, IMA can be used as a biochemical parameter for monitoring muscle flap viability.

  8. The force-length curves of the human rectus femoris and gastrocnemius muscles in vivo.

    PubMed

    Winter, Samantha L; Challis, John H

    2010-02-01

    For a physiologically realistic joint range of motion and therefore range of muscle fiber lengths, only part of the whole muscle force-length curve can be used in vivo; that is, only a section of the force-length curve is expressed. Previous work has determined that the expressed section of the force-length curve for individual muscles can vary between subjects; however, the degree of intersubject variability is different for different muscles. This study determined the expressed section of both the rectus femoris and gastrocnemius--muscles with very different ratios of tendon slack length to muscle fiber optimum length--for 28 nonspecifically trained subjects to test the hypothesis that the value of this ratio affects the amount of variability in the expressed section. The force-length curves of the two muscles were reconstructed from moment-angle data using the method of Herzog & ter Keurs (1988). There was no relationship between the expressed sections of the force-length curve for the two muscles. Less variability was found in the expressed section of the gastrocnemius compared with the rectus femoris, supporting the hypothesis. The lack of relationship between the expressed sections of the two muscles has implications for motor control and for training muscle for rehabilitation.

  9. Reconstruction of full-thickness chest wall defects using rectus abdominis musculocutaneous flap: A report of fifteen cases

    SciTech Connect

    Miyamoto, Y.; Hattori, T.; Niimoto, M.; Toge, T. )

    1986-02-01

    In 15 patients chest walls were excised because of recurrent breast cancer, radiation ulcer, or rib tumor. In most cases the full-thickness defect of the chest wall was about 10 x 10 cm. Reconstruction was performed using only a rectus abdominis musculocutaneous flap. No patient developed circulation problems in the flap or severe flail chest, and we had successful results in all our cases. These results show that the rectus abdominis musculocutaneous flap is quite effective and safe to use in the reconstruction of chest wall defects.

  10. Characterization of the invasive and inflammatory traits of oral Campylobacter rectus in a murine model of fetoplacental growth restriction and in trophoblast cultures

    PubMed Central

    Arce, R.M.; Diaz, P.I.; Barros, S.P.; Galloway, P.; Bobetsis, Y.; Threadgill, D.; Offenbacher, S.

    2010-01-01

    Campylobacter species (C. jejuni, C. fetus) are enteric abortifacient bacteria in humans and ungulates. Campylobacter rectus is a periodontal pathogen associated with human fetal exposure and adverse pregnancy outcomes including preterm delivery. Experiments in pregnant mice have demonstrated that C. rectus can translocate from a distant site of infection to the placenta to induce fetal growth restriction and impair placental development. However, placental tissues from human, small-for-gestational age deliveries have not been reported to harbor C. rectus despite evidence of maternal infection and fetal exposure by fetal IgM response. This investigation examined the temporal relationship between the placental translocation of C. rectus and the effects on fetal growth in mice. BALB/c mice were infected at gestational day E7.5 to examine placental translocation of C. rectus by immunohistology. C. rectus significantly decreased fetoplacental weight at E14.5 and at E16.5. C. rectus was detected in 63% of placentas at E14.5, but not at E16.5. In in vitro trophoblast invasion assays, C. rectus was able to effectively invade human trophoblasts (BeWo) but not murine trophoblasts (SM9-1), and showed a trend for more invasiveness than C. jejuni. C. rectus challenge significantly upregulated both mRNA and protein levels of IL-6 and TNFα in a dose-dependent manner in human trophoblasts, but did not increase cytokine expression in murine cells, suggesting a correlation between invasion and cytokine activation. In conclusion, the trophoblast-invasive trait of C. rectus that appears limited to human trophoblasts may play a role in facilitating bacterial translocation and placental inflammation during early gestation. PMID:20089314

  11. The snapping medial antebrachial cutaneous nerve.

    PubMed

    Cesmebasi, Alper; O'driscoll, Shawn W; Smith, Jay; Skinner, John A; Spinner, Robert J

    2015-10-01

    Snapping elbow is a well-known condition where elbow flexion and extension elicits a painful, popping sensation. The most frequent etiology is anterior dislocation of the ulnar nerve over the medial epicondyle. Four patients (3 females and 1 male) presented with complaints of a popping sensation in the elbow, pain over the medial aspect of the forearm, and ulnar neuritis. All patients underwent preoperative dynamic ultrasound and surgical exploration of the medial elbow. Intraoperatively, snapping of the MABC over the medial epicondyle was discovered in all four patients. In three patients, there was abnormal displacement of the medial triceps and ulnar nerve: in two of these, both structures dislocated over the medial epicondyle and in one patient both structures subluxated. In each case, the MABC was decompressed (n = 1) and transposed (n = 3), and in three cases, the medial triceps and ulnar nerve were addressed as well. Symptomatic improvement was achieved in all cases. Retrospective review of the ultrasound revealed the snapping MABC, though it was less effective prospectively in the cases when snapping MABC was not suspected. In conclusion, snapping of the MABC broadens the spectrum of disorders that results in snapping elbow. To our knowledge, we are unaware of prior reports of this entity.

  12. Morphological and histomorphometric evaluation of the ventral rectus sheath of the rectus abdominis muscle, fascia lata and pectoral fascia. The beginning of a morphological information bank of human fascias.

    PubMed

    Morales-Avalos, Rodolfo; Soto-Domínguez, Adolfo; García-Juárez, Jaime; Cardenas-Serna, Marcela; Esparza-Hernández, Claudia N; Carreño-Salcedo, Sofía Alejandra; Montes-de-Oca-Luna, Roberto; Loera-Arias, María de Jesús; Saucedo-Cárdenas, Odila; Elizondo-Omaña, Rodrigo E; Guzmán-López, Santos

    2017-03-01

    The aim of this study was to characterize and compare the morphological and histomorphometric characteristics of the pectoral fascia, fascia lata and ventral rectus sheath. Twenty cadaveric samples of these fascias were analyzed and stained with hematoxylin and eosin, orcein, Van Gieson, Masson's trichrome and Verhoeff¨s stain (1200 slides in total). Morphological evaluation, semiquantitative, morphometric and microdensitometric analysis of elastic fibers present in each of the tissues and a morphometrical analysis of tissue thickness were performed. The mean value of the pectoral fascia thickness was 612±68.13 μm; 84±246 μm for the fascia lata and 584±92 μm for the ventral rectus sheath. The area occupied by the elastic fibers in the pectoral fascia was 12.24±5.84%; 6,54±3.85% for the fascia lata and 11.11±5.26% for the ventral rectus sheath. There were no statistically significant differences when comparing the mean values between the pectoral fascia and the ventral rectus sheath (p=0.07). There were statistically significant differences when comparing the fascia lata to the pectoral fascia and the ventral rectus sheath (p≤0.001). This study reports other morphological characteristics not described in previous histological studies of the analyzed tissues. The results of the morphometric and densitometric analysis in this study reveal that the fascia lata has the fewest elastic fibers of all the tissues analyzed, and the pectoral fascia has the most. These results will be useful for the beginning of a morphological information bank of human fascias.

  13. Use of MMG signals for the control of powered orthotic devices: development of a rectus femoris measurement protocol.

    PubMed

    Antonelli, Michele Gabrio; Zobel, P Beomonte; Giacomin, J

    2009-01-01

    A test protocol is defined for the purpose of measuring rectus femoris mechanomyographic (MMG) signals. The protocol is specified in terms of the following: measurement equipment, signal processing requirements, human postural requirements, test rig, sensor placement, sensor dermal fixation, and test procedure. Preliminary tests of the statistical nature of rectus femoris MMG signals were performed, and Gaussianity was evaluated by means of a two-sided Kolmogorov-Smirnov test. For all 100 MMG data sets obtained from the testing of two volunteers, the null hypothesis of Gaussianity was rejected at the 1%, 5%, and 10% significance levels. Most skewness values were found to be greater than 0.0, while all kurtosis values were found to be greater than 3.0. A statistical convergence analysis also performed on the same 100 MMG data sets suggested that 25 MMG acquisitions should prove sufficient to statistically characterize rectus femoris MMG. This conclusion is supported by the qualitative characteristics of the mean rectus femoris MMG power spectral densities obtained using 25 averages.

  14. Relationships between Muscle Architecture of Rectus Femoris and Functional Parameters of Knee Motion in Adults with Down Syndrome

    PubMed Central

    Micale, Marco; Cioni, Matteo

    2016-01-01

    This study was designed to measure in vivo muscle architecture of the rectus femoris in adults with Down syndrome, testing possible relationships with functional parameters of the knee motion. Ten adults with Down syndrome and ten typically developed participated in the study. Pennation angle and thickness of the rectus femoris and subcutaneous layer of the thigh were measured via ultrasound imaging. Knee kinematics and electromyographic activity of the rectus femoris were recorded during free leg dropping. Muscle thickness was reduced and subcutaneous layer was thicker in persons with Down syndrome with respect to typically developed adults, but there were no differences in the pennation angle. The area of the rectus femoris EMG activity during the leg flexion was greater in Down syndrome with respect to typically developed adults. The leg movement velocity was lower in Down people than in controls, but the knee excursion was similar between the groups. Functional parameters correlated with pennation angle in the persons with Down syndrome and with muscle thickness in typically developed persons. The description of muscle architecture and the relationships between morphological and functional parameters may provide insights on the limits and the opportunities to overcome the inherent biomechanical instability in Down syndrome. PMID:27896273

  15. Relationships between Muscle Architecture of Rectus Femoris and Functional Parameters of Knee Motion in Adults with Down Syndrome.

    PubMed

    Valle, Maria Stella; Casabona, Antonino; Micale, Marco; Cioni, Matteo

    2016-01-01

    This study was designed to measure in vivo muscle architecture of the rectus femoris in adults with Down syndrome, testing possible relationships with functional parameters of the knee motion. Ten adults with Down syndrome and ten typically developed participated in the study. Pennation angle and thickness of the rectus femoris and subcutaneous layer of the thigh were measured via ultrasound imaging. Knee kinematics and electromyographic activity of the rectus femoris were recorded during free leg dropping. Muscle thickness was reduced and subcutaneous layer was thicker in persons with Down syndrome with respect to typically developed adults, but there were no differences in the pennation angle. The area of the rectus femoris EMG activity during the leg flexion was greater in Down syndrome with respect to typically developed adults. The leg movement velocity was lower in Down people than in controls, but the knee excursion was similar between the groups. Functional parameters correlated with pennation angle in the persons with Down syndrome and with muscle thickness in typically developed persons. The description of muscle architecture and the relationships between morphological and functional parameters may provide insights on the limits and the opportunities to overcome the inherent biomechanical instability in Down syndrome.

  16. Workhorse Flaps in Chest Wall Reconstruction: The Pectoralis Major, Latissimus Dorsi, and Rectus Abdominis Flaps

    PubMed Central

    Bakri, Karim; Mardini, Samir; Evans, Karen K.; Carlsen, Brian T.; Arnold, Phillip G.

    2011-01-01

    Large and life-threatening thoracic cage defects can result from the treatment of traumatic injuries, tumors, infection, congenital anomalies, and radiation injury and require prompt reconstruction to restore respiratory function and soft tissue closure. Important factors for consideration are coverage with healthy tissue to heal a wound, the potential alteration in respiratory mechanics created by large extirpations or nonhealing thoracic wounds, and the need for immediate coverage for vital structures. The choice of technique depends on the size and extent of the defect, its location, and donor site availability with consideration to previous thoracic or abdominal operations. The focus of this article is specifically to describe the use of the pectoralis major, latissimus dorsi, and rectus abdominis muscle flaps for reconstruction of thoracic defects, as these are the workhorse flaps commonly used for chest wall reconstruction. PMID:22294942

  17. Insertional tendinopathy of the adductors and rectus abdominis in athletes: a review

    PubMed Central

    Valent, Alessandro; Frizziero, Antonio; Bressan, Stefano; Zanella, Elena; Giannotti, Erika; Masiero, Stefano

    2012-01-01

    Summary Insertional tendinopathy of the adductors and rectus abdominis is common in male athletes, especially in soccer players. It may be worsened by physical activity and it usually limits sport performance. The management goal in the acute phase consists of analgesic and anti-inflammatory drugs and physical rehabilitation. In the early stages of rehabilitation, strengthening exercises of adductors and abdominal muscles, such as postural exercises, have been suggested. In the sub-acute phase, muscular strength is targeted by overload training in the gym or aquatherapy; core stability exercises seem to be useful in this phase. Finally, specific sport actions are introduced by increasingly complex exercises along with a preventive program to limit pain recurrences. PMID:23738289

  18. Extensive Chest Wall Tissue Loss and its Management by Vertical Rectus Abdominis Myocutaneous Flap

    PubMed Central

    Basu, Sandip Kanti; Bain, Jayanta; Chattopadhyay, Debarati; Majumdar, Bijay Kumar

    2017-01-01

    Extensive electric burn around the chest in children is rare and this type of injury always poses a great challenge for its management. A 12-year-old male child with extensive electric burn of the chest wall was admitted to hospital. It was a neglected case of 9 days old burn; the young boy was in critical condition having systemic features of toxemia with widespread necrosis of the skin, subcutaneous tissues, and muscles along with exposed bones (ribs and sternum) with the risk of impending rupture of pleura through the exposed intercostal spaces. After initial resuscitation, a thorough debridement of all necrotic tissues was done. Thereafter, a superiorly based vertical rectus abdominis myocutaneous flap was harvested to cover the exposed bones and intercostal spaces. The remaining raw areas were skin grafted. The child made an excellent recovery with good outcome. PMID:28082777

  19. A panel data set on harvest and perfusion decellularization of porcine rectus abdominis

    PubMed Central

    Zhang, Jian; Cheng, Wen Yue; Hu, Zhi Qian; Turner, Neill J.; Zhang, Li; Wang, Qiang; Badylak, Stephen F.

    2016-01-01

    In this dataset, we particularly depicted the harvest and perfusion decellularization of porcine rectus abdominis (RA), accompanied with displaying of the retained vascular trees within the perfusion-decellularized skeletal muscle matrix (pM-ECM) using vascular corrosion casting. In addition, several important tips for successful pM-ECM preparation were emphasized, which including using anatomically isolated skeletal muscle as tissue source with all main feeding and draining vessels perfused, preserving the internal microcirculation availability, aseptic technique and pyrogen free in all steps, sequential perfusion via artery or vein, and longtime washing after decellularization. The data are supplemental to our original research article describing detailed associations of pM-ECM as a clinically relevant scale, three-dimensional scaffold with a vascular network template for tissue-specific regeneration, “Perfusion-decellularized skeletal muscle as a three-dimensional scaffold with a vascular network template” Zhang et al. (2016) [1]. PMID:27158653

  20. [Tibial periostitis ("medial tibial stress syndrome")].

    PubMed

    Fournier, Pierre-Etienne

    2003-06-01

    Medial tibial stress syndrome is characterised by complaints along the posteromedial tibia. Runners and athletes involved in jumping activities may develop this syndrome. Increased stress to stabilize the foot especially when excessive pronation is present explain the occurrence this lesion.

  1. Reliability of the inter-rectus distance measured by palpation. Comparison of palpation and ultrasound measurements.

    PubMed

    Mota, Patrícia; Pascoal, Augusto Gil; Sancho, Fátima; Carita, Ana Isabel; Bø, Kari

    2013-08-01

    An increased inter-rectus distance (IRD) is a common condition in late pregnancy and in the postnatal period. The condition is difficult to assess. Palpation is the most commonly used method to assess IRD. To date there is scant knowledge of intra and inter-tester reliability of palpation to measure IRD and how palpation compares with ultrasound measurements. The aims of this study were: 1) evaluate intra and inter-rater reliability of abdominal palpation; 2) validate abdominal palpation of IRD measurements using ultrasound imaging as a reference. Two physiotherapists (PTs) conducted the palpation study in random order, blinded to each other's assessments. IRD was measured as finger widths between the two rectus abdominis (RA) muscles. Ultrasound images were recorded at the same locations as the palpation test. A blinded investigator measured the IRD offline. Palpation showed good intra-rater reliability between days expressed by a weighted Kappa (wK) higher than 0.7 for both physiotherapists, and moderate inter-rater reliability (wK = 0.534). Ultrasound was found to be more responsive for differences in IRD compared with values obtained by palpation. The intra-rater reliability was higher than the inter-rater reliability. Besides the difference in experience with palpation testing between the PTs, this result may be due to differences in finger width and/or the subjective interpretation of abdominal soft-tissues pressure. Ultrasound measures are highly sensitive to changes of IRD, which is not possible to replicate by palpation assessment using a finger width scale. Palpation has sufficient reliability to be used in clinical practice. However, ultrasound is a more accurate and valid method and is recommended in future research of IRD.

  2. Medial medullary infarction: abnormal ocular motor findings.

    PubMed

    Kim, J Soo; Choi, K-D; Oh, S-Y; Park, S-H; Han, M-K; Yoon, B-W; Roh, J-K

    2005-10-25

    In 20 consecutive patients with isolated medial medullary infarction, abnormal ocular motor findings included nystagmus (n = 8), ocular contrapulsion (n = 5), and contralesional ocular tilt reaction (n = 2). The nystagmus was ipsilesional (n = 4), gaze-evoked (n = 5), upbeating (n = 4), and hemiseesaw (n = 1). The ocular motor abnormalities may be explained by involvements of the nucleus prepositus hypoglossi, medial longitudinal fasciculus or efferent fibers from the vestibular nuclei, climbing fibers, and cells of the paramedian tracts.

  3. The medial sural artery perforator free flap.

    PubMed

    Cavadas, P C; Sanz-Giménez-Rico, J R; Gutierrez-de la Cámara, A; Navarro-Monzonís, A; Soler-Nomdedeu, S; Martínez-Soriano, F

    2001-11-01

    The medial sural artery supplies the medial gastrocnemius muscle and sends perforating branches to the skin. The possible use of these musculocutaneous perforators as the source of a perforator-based free flap was investigated in cadavers. Ten legs were dissected, and the topography of significant perforating musculocutaneous vessels on both the medial and the lateral gastrocnemius muscles was recorded. A mean of 2.2 perforators (range, 1 to 4) was noted over the medial gastrocnemius muscle, whereas in only 20 percent of the specimens was a perforator of moderate size noted over the lateral gastrocnemius muscle. The perforating vessels from the medial sural artery clustered about 9 to 18 cm from the popliteal crease. When two perforators were present (the most frequent case), the perforators were located at a mean of 11.8 cm (range, 8.5 to 15 cm) and 17 cm (range, 15 to 19 cm) from the popliteal crease. A series of six successful clinical cases is reported, including five free flaps and one pedicled flap for ipsilateral lower-leg and foot reconstruction. The dissection is somewhat tedious, but the vascular pedicle can be considerably long and of suitable caliber. Donor-site morbidity was minimal because the muscle was not included in the flap. Although the present series is short, it seems that the medial sural artery perforator flap can be a useful flap for free and pedicled transfer in lower-limb reconstruction.

  4. Successful application of endoscopic modified medial maxillectomy to orbital floor trapdoor fracture in a pediatric patient.

    PubMed

    Matsuda, Yasunori; Sakaida, Hiroshi; Kobayashi, Masayoshi; Takeuchi, Kazuhiko

    2016-10-01

    Although surgical treatment of orbital floor fractures can be performed by many different approaches, the application of endoscopic modified medial maxillectomy (EMMM) for this condition has rarely been described in the literature. We report on a case of a 7-year-old boy with a trapdoor orbital floor fracture successfully treated with the application of EMMM. The patient suffered trauma to the right orbit floor and the inferior rectus was entrapped at the orbital floor. Initially, surgical repair via endoscopic endonasal approach was attempted. However, we were unable to adequately access the orbital floor through the maxillary ostium. Therefore, an alternative route of access to the orbital floor was established by EMMM. With sufficient visualization and operating space, the involved orbital content was completely released from the entrapment site and reduced into the orbit. To facilitate wound healing, the orbital floor was supported with a water-inflated urethral balloon catheter for 8 days. At follow-up 8 months later, there was no gaze restriction or complications associated with the EMMM. This case illustrates the efficacy and safety of EMMM in endoscopic endonasal repair of orbital floor fracture, particularly for cases with a narrow nasal cavity such as in pediatric patients.

  5. Isolated primary amyloidosis of the inferior rectus muscle mimicking Graves' orbitopathy.

    PubMed

    Monteiro, Mário Luiz Ribeiro; Gonçalves, Allan Christian Pieroni; Bezerra, Alanna Mara Pinheiro Sobreira

    2016-01-01

    The diagnosis of Graves' orbitopathy is usually straightforward. However, orbital diseases that mimick some clinical signs of Graves' orbitopathy may cause diagnostic confusion, particularly when associated to some form of thyroid dysfunction. This report describes the rare occurrence of localized inferior rectus muscle amyloidosis in a patient with autoimmune hypothyroidism, who was misdiagnosed as Graves' orbitopathy. A 48-year-old man complained of painless progressive proptosis on the left side and intermittent vertical diplopia for 6 months. The diagnosis of Graves' orbitopathy was entertained after magnetic resonance imaging revealing a markedly enlarged, tendon-sparing inferior rectus enlargement on the left side, and an autoimmune hypothyroidism was disclosed on systemic medical workup. After no clinical improvement with treatment, the patient was referred to an ophthalmologist and further investigation was performed. The presence of calcification in the inferior rectus muscle on computed tomography, associated with the clinical findings led to a diagnostic biopsy, which revealed amyloid deposition. This report emphasizes that a careful evaluation of atypical forms of Graves' orbitopathy may be crucial and should include, yet with rare occurrence, amyloidosis in its differential diagnosis. RESUMO O diagnóstico de orbitopatia de Graves usualmente é fácil de ser estabelecido. No entanto, doenças da órbita que simulam alguns sinais clínicos da orbitopatia de Graves podem levar à confusão diagnóstica, particularmente quando associada à alguma forma de disfunção tireoidiana. Relatamos a ocorrência rara de amiloidose localizada no músculo reto inferior em paciente com hipotireoidismo autoimune, que recebeu inicialmente o diagnóstico errôneo de orbitopatia de Graves. Paciente masculino, 48 anos, com queixa de proptose progressiva e indolor do lado esquerdo e diplopia vertical intermitente há 6 meses. O diagnóstico de orbitopatia de Graves foi

  6. Comparison of Postoperative Exodrift after First Unilateral and Second Contralateral Lateral Rectus Recession in Recurrent Exotropia

    PubMed Central

    Kim, Eun Yeong; Kim, Hyun Kyung; Lee, Se Youp

    2016-01-01

    Purpose To compare postoperative exodrift of the first unilateral lateral rectus (ULR) muscle recession with the exodrift of the second contralateral ULR muscle recession in patients with recurrent small-angle exotropia (XT). Methods We evaluated the results of a second ULR muscle recession in 19 patients with recurrent XT with deviation angles under 25 prism diopter (PD), following a first procedure of ULR muscle recession for small-angle XT. Recession of the lateral rectus muscle ranged from 8 to 9 mm. The postoperative motor alignment and degree of exodrift were investigated after the first ULR muscle recession and the second ULR muscle recession in the same patients. Results Observed differences in postoperative ocular alignment between the first ULR muscle recession and the second ULR muscle recession were statistically significant at follow-up periods of six months (7.84 ± 4.43 vs. 3.89 ± 3.47 PD), one year (9.58 ± 4.97 vs. 5.21 ± 4.94 PD), and at a final follow-up (21.11 ± 2.98 vs. 7.52 ± 4.06 PD) after surgery (p = 0.006, 0.013, and 0.000). Postoperative exodrift was statistically different between the first and second ULR muscle recessions at three to six months (2.89 ±3.75 vs. 0.63 ± 3.45 PD) and one year to final follow-up (11.52 ± 5.50 vs. 2.32 ± 3.53 PD) (p = 0.034 and 0.000). All of the first ULR muscle recession patients showed XT with deviation angles of more than 15 PD at the final follow-up. Regardless, the surgical success rate (<8 PD) after the second ULR recession was 63.16% (12 patients) among the total amount of patients with recurrent XT. Conclusions This study shows that changes in exodrift after a second ULR muscle recession are less than changes after the first URL muscle recession among patients with recurrent XT. A second ULR muscle recession may be a useful surgery for small-angle XT patients with deviation angles of 25 PD or less after a first ULR muscle recession. PMID:26865803

  7. EFFECTS OF 2-PAM AND EA 1814 ON NEUROMUSCULAR TRANSMISSION. I. EFFECTS OF 2-PAM AND EA 1814 ON THE FROG RECTUS ABDOMINIS MUSCLE PREPARATION

    DTIC Science & Technology

    Contracture of the isolated frog Rectus abdominis muscle was used to study pharmacological properties of 2-PAM (2-pyridine aldoxime methiodide) and...example, concentrations of 2-PAM in excess of 4 x 10 to the -5th power M potentiate contractures of the frog rectus muscle elicited by acetylcholine...2-PAM inhibits the response to the depolarizing agents, decamethonium and carbamylcholine, which are not susceptible to hydrolysis by the ChE of frog

  8. Postselected weak measurement beyond the weak value

    SciTech Connect

    Geszti, Tamas

    2010-04-15

    Closed expressions are derived for the quantum measurement statistics of pre- and postselected Gaussian particle beams. The weakness of the preselection step is shown to compete with the nonorthogonality of postselection in a transparent way. The approach is shown to be useful in analyzing postselection-based signal amplification, allowing measurements to be extended far beyond the range of validity of the well-known Aharonov-Albert-Vaidman limit. Additionally, the present treatment connects postselected weak measurement to the topic of phase-contrast microscopy.

  9. Clinical utility of the Duncan-Ely test for rectus femoris dysfunction during the swing phase of gait.

    PubMed

    Marks, M C; Alexander, J; Sutherland, D H; Chambers, H G

    2003-11-01

    The Ely Test (or Duncan-Ely test) has been accepted as a clinical tool to assess rectus femoris spasticity by passively flexing the knee rapidly while the patient lies prone in a relaxed state. In this retrospective review, patients' dynamic knee range of motion (ROM) during gait and an electromyogram (EMG) were compared with the results of the Ely test. Data for 70 patients (44 males, 26 females; 104 limbs) were included. Mean age of patients was 13 years, SD 9 years, range 4 years 5 months to 54 years. All patients were diagnosed with cerebral palsy (spastic diplegia, n = 42; spastic quadriplegia, n = 15, and hemiplegia, n = 13). All patients were ambulatory (50 independent, 20 with assistive devices). A standard matrix was used to calculate sensitivity and specificity of the Ely test as well as its positive and negative predictive value. For the gait variables examined (decreased dynamic knee ROM, timing of peak knee flexion, and abnormal EMG in swing) the sensitivity of the Ely test ranged from 56 to 59% and the specificity ranged from 64 to 85%. For the same variables the positive predictive value ranged from 91 to 98% and the negative predictive value ranged from 4 to 19%. The Ely test was shown to have a good positive predictive value (i.e. the certainty about the presence of rectus spasticity in patients with a positive Ely test result) for rectus femoris dysfunction during gait.

  10. Using the traditional model to evaluate the active force of the human lateral rectus muscle

    NASA Astrophysics Data System (ADS)

    Gao, ZhiPeng; Chen, WeiYi; Jing, Lin; Feng, PengFei; Wu, XiaoGang; Guo, HongMei

    2014-05-01

    The information on the force of extraocular muscles (EOMs) is beneficial for strabismus diagnosis and surgical planning, and a direct and simple method is important for surgeons to obtain these forces. Based on the traditional model, a numerical simulation method was proposed to achieve this aim, and then the active force of the lateral rectus (LR) muscle was successfully simulated when the eye rotated every angle from 0° to 30° in the horizontal plane from the nasal to the temporal side. In order to verify these simulations, the results were compared with the previous experimental data. The comparison shows that the simulation results diverged much more than the experimental data in the range of 0°-10°. The errors were corrected to make the simulation results closer to the experimental data. Finally, a general empirical equation was proposed to evaluate the active force of the LR muscle by fitting these data, which represent the relationship between the simulation forces and the contractive amounts of the LR muscle.

  11. Functional Improvement Following Diastasis Rectus Abdominus Repair in an Active Duty Navy Female.

    PubMed

    Gallus, Katerina M; Golberg, Kathy F; Field, Robert

    2016-08-01

    Return to physical activity following childbirth can be a difficult process complicated by structural changes during pregnancy. A common problem is the development of a diastasis of the rectus abdominus (DRA), defined as a horizontal separation of the abdominus muscles at the linea alba. Recent data indicate that the greater the distance of separation of the muscle, the worse the functional ability. We describe a 24-year-old active duty U.S. Navy female G1P2 with a diagnosis of DRA. At 2 months postpartum, she was referred to physical therapy because of back pain and inability to meet baseline activities of daily living. After 4 months of physical therapy, she was unable to complete curl ups as required by U.S. Navy physical fitness standards. Abdominoplasty with imbrication of the abdominal wall diastasis was performed followed by additional physical therapy, after which she returned to baseline functioning. The restoration of functional ability postoperatively suggests there is a therapeutic indication for surgical correction of DRA. In high-functioning military patients with DRA who fail to return to baseline level of activity following a trial of physical therapy, surgical intervention should be considered to obtain the optimal functional ability.

  12. Efficacy of Transversus Abdominis Plane Block and Rectus Sheath Block in Laparoscopic Inguinal Hernia Surgery

    PubMed Central

    Takebayashi, Katsushi; Matsumura, Masakata; Kawai, Yasuhiro; Hoashi, Takahiko; Katsura, Nagato; Fukuda, Seijun; Shimizu, Kenji; Inada, Takuji; Sato, Masugi

    2015-01-01

    We aimed to assess the efficacy of transversus abdominis plane (TAP) block and rectus sheath (RS) block in patients undergoing laparoscopic inguinal hernia surgery. Few studies have addressed the efficacy and safety associated with TAP block and RS block for laparoscopic surgery. Thirty-two patients underwent laparoscopic inguinal hernia surgery, either with TAP and RS block (Block+ group, n = 18) or without peripheral nerve block (Block− group, n = 14). Preoperatively, TAP and RS block were performed through ultrasound guidance. We evaluated postoperative pain control and patient outcomes. The mean postoperative hospital stays were 1.56 days (Block+ group) and 2.07 days (Block− group; range, 1–3 days in both groups; P = 0.0038). A total of 11 patients and 1 patient underwent day surgery in the Block+ and Block− groups, respectively (P = 0.0012). Good postoperative pain control was more commonly observed in the Block+ group than in the Block− group (P = 0.011). TAP and RS block was effective in reducing postoperative pain and was associated with a fast recovery in patients undergoing laparoscopic inguinal hernia surgery. PMID:25875548

  13. Complications and oncologic outcomes of pedicled transverse rectus abdominis myocutaneous flap in breast cancer patients

    PubMed Central

    Somintara, Ongart; Lertsithichai, Panuwat; Kongdan, Youwanush; Supsamutchai, Chairat; Sukpanich, Rupporn

    2016-01-01

    Background There are several techniques for harvesting the pedicled transverse rectus abdominis myocutaneous (TRAM) flap after mastectomy in breast cancer patients. We examined the whole muscle with partial sheath sparing technique and determined factors associated with its complications and oncological outcomes. Methods We retrospectively reviewed the results of 168 TRAM flaps performed between January 2003 and December 2010, focusing on complications and oncologic outcomes. Results Among the 168 pedicled TRAM flap procedures in 158 patients, flap complications occurred in 34%. Most of the flap complications included some degree of fat necrosis. There was no total flap loss. Flap complications were associated with elderly patients and the presence of major donor site complications. Abdominal bulging and hernia occurred in 12% of patients. The bi-pedicled TRAM flap and higher body mass index (BMI) were significant factors associated with increased donor site complications. Seven patients (4%) developed loco-regional recurrence. Within a median follow-up of 27 months, distant metastasis and death occurred in 6% and 4% of patients, respectively. Conclusions The pedicled TRAM flap using the whole muscle with partial sheath sparing technique in the present study is consistent with the results from previous studies in flap complication rates and oncological outcomes. PMID:27563562

  14. Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.

    PubMed

    Hacker, Eileen Danaher; Peters, Tara; Garkova, Miglena

    2016-09-01

    Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass.

  15. DOES RECTUS FEMORIS TRANSFER INCREASE KNEE FLEXION DURING STANCE PHASE IN CEREBRAL PALSY?

    PubMed Central

    de Morais, Mauro César; Blumetti, Francesco Camara; Kawamura, Cátia Miyuki; Lopes, José Augusto Fernandes; Neves, Daniella Lins; Cardoso, Michelle de Oliveira

    2016-01-01

    ABSTRACT Objective: To evaluate whether distal rectus femoris transfer (DRFT) is related to postoperative increase of knee flexion during the stance phase in cerebral palsy (CP). Methods: The inclusion criteria were Gross Motor Function Classification System (GMFCS) levels I-III, kinematic criteria for stiff-knee gait at baseline, and individuals who underwent orthopaedic surgery and had gait analyses performed before and after intervention. The patients included were divided into the following two groups: NO-DRFT (133 patients), which included patients who underwent orthopaedic surgery without DRFT, and DRFT (83 patients), which included patients who underwent orthopaedic surgery that included DRFT. The primary outcome was to evaluate in each group if minimum knee flexion in stance phase (FMJFA) changed after treatment. Results: The mean FMJFA increased from 13.19° to 16.74° (p=0.003) and from 10.60° to 14.80° (p=0.001) in Groups NO-DRFT and DRFT, respectively. The post-operative FMJFA was similar between groups NO-DRFT and DRFT (p=0.534). The increase of FMJFA during the second exam (from 13.01° to 22.51°) was higher among the GMFCS III patients in the DRFT group (p<0.001). Conclusion: In this study, DRFT did not generate additional increase of knee flexion during stance phase when compared to the control group. Level of Evidence III, Retrospective Comparative Study. PMID:26997910

  16. Is myoelectric activity distributed equally within the rectus femoris muscle during loaded, squat exercises?

    PubMed

    de Souza, Leonardo Mendes Leal; da Fonseca, Desirée Barros; Cabral, Hélio da Veiga; de Oliveira, Liliam Fernandes; Vieira, Taian Martins

    2017-04-01

    Recent evidence suggests different regions of the rectus femoris (RF) muscle respond differently to squat exercises. Such differential adaptation may result from neural inputs distributed locally within RF, as previously reported for isometric contractions, walking and in response to fatigue. Here we therefore investigate whether myoelectric activity distributes evenly within RF during squat. Surface electromyograms (EMGs) were sampled proximally and distally from RF with arrays of electrodes, while thirteen healthy volunteers performed 10 consecutive squats with 20% and 40% of their body weight. The root mean square (RMS) value, computed separately for thirds of the concentric and eccentric phases, was considered to assess the proximo-distal changes in EMG amplitude during squat. The channels with variations in EMG amplitude during squat associated with shifts in the muscle innervation zone were excluded from analysis. No significant differences were observed between RF regions when considering squat phases and knee joint angles individually (P>0.16) while a significant interaction between phase and knee joint angle with detection site was observed (P<0.005). For the two loads considered, proximal RMS values were greater during the eccentric phase and for the more flexed knee joint position (P<0.001). Our results suggest inferences on the degree of RF activation during squat must be made cautiously from surface EMGs. Of more practical relevance, there may be a potential for the differential adaption of RF proximal and distal regions to squat exercises.

  17. Influence of angular velocity on vastus lateralis and rectus femoris oxygenation dynamics during knee extension exercises.

    PubMed

    Denis, Romain; Wilkinson, Jennifer; De Vito, Giuseppe

    2011-09-01

    The purpose of this study was to investigate whether changes in angular velocity would alter vastus lateralis (VL) and rectus femoris (RF) oxygenation status during maximal isokinetic knee extension exercises. Eleven recreationally active male participants randomly performed ten maximal knee extensions at 30, 60, 120 and 240° s(-1). Tissue oxygenation index (TOI) and total haemoglobin concentration ([tHb]) were acquired from the VL and RF muscles by means of near-infrared spectroscopy (NIRS). Breath-by-breath pulmonary oxygen consumption (VO(2p)) was recorded throughout the tests. Peak torque and VO(2p) significantly decreased as a function of velocity (P<0·05). Interestingly, RF and VL TOI significantly increased as a function of velocity (P<0·05), whereas [tHb] significantly decreased as a function of velocity (P<0·05). A greater number of muscle fibre recruited at slow velocity, where the torque and VO(2p) were the highest, might explain the lower VL and RF TOI observed herein. Furthermore, the increase in local blood flow (suggested by [tHb] changes) during isokinetic knee extension exercises performed at slow angular velocity might have been induced by a higher intramuscular pressure during the contraction phases as well as a greater microcirculatory vasodilatation during relaxation phases. Implementing slow-velocity isokinetic exercises in rehabilitation or other training programmes could delay the short-term anoxia generated by such exercises and result in muscle metabolism enhancement.

  18. Medial Canthoplasty Combined with Conjunctivodacryocystorhinostomy for the Treatment of Delayed Medial Telecanthal Deformity

    PubMed Central

    Sun, Hua; Li, Yang; Huang, Qian; Ding, Jing-Wen; Hou, Zhi-Jia; Li, Dong-Mei

    2017-01-01

    Background: Rupture of the medial canthal ligament can be caused by many events. It remains a challenge to rebuild the drainage system and restore the function. The aim of this study was to evaluate the clinical efficacy of medial canthoplasty combined with conjunctivodacryocystorhinostomy (CDCR) in patients with medial telecanthal deformities and lacrimal drainage system damage. Methods: Twenty-two patients (22 eyes) treated with medial canthoplasty and CDCR during June 2012 to June 2014 were included in this retrospective study. For all patients, a self-tapping, titanium, low-profile head microscrew was drilled into the solid bone on the posterior aspect of the anterior lacrimal crest at the attachment position of the medial canthal ligament. Medpor-coated tear drainage tubes were applied. Distance of patient's lateral displacement before and after operation was recorded and compared. The complications of CDCR were described. Results: Before the surgery, distance of patient's canthal displacement was 4–6 mm. The canthal distance between two eyes of patients with surgery was 1 mm or less. Among patients with CDCR, four patients had proximal obstruction and two patients had distal obstruction. Five patients had tube malposition, for example, tube extrusion 1–3 months after surgery. Conclusions: Medial canthoplasty combined with CDCR is an effective surgical method for treatment of patients with medial telecanthal deformity and lacrimal drainage system obstruction. The study indicates that medial canthoplasty combined with CDCR surgery rebuilds normal appearance of eyelid and contour of the medial canthus and successfully repairs the function of the lacrimal drainage system. PMID:28303853

  19. Affective Aprosodia from a Medial Frontal Stroke

    ERIC Educational Resources Information Center

    Heilman, Kenneth M.; Leon, Susan A.; Rosenbek, John C.

    2004-01-01

    Background and objectives: Whereas injury to the left hemisphere induces aphasia, injury to the right hemisphere's perisylvian region induces an impairment of emotional speech prosody (affective aprosodia). Left-sided medial frontal lesions are associated with reduced verbal fluency with relatively intact comprehension and repetition…

  20. Robust Weak Measurements

    NASA Astrophysics Data System (ADS)

    Tollaksen, Jeff; Aharonov, Yakir

    2006-03-01

    We introduce a new type of weak measurement which yields a quantum average of weak values that is robust, outside the range of eigenvalues, extends the valid regime for weak measurements, and for which the probability of obtaining the pre- and post-selected ensemble is not exponentially rare. This result extends the applicability of weak values, shifts the statistical interpretation previously attributed to weak values and suggests that the weak value is a property of every pre- and post-selected ensemble. We then apply this new weak measurement to Hardy's paradox. Usually the paradox is dismissed on grounds of counterfactuality, i.e., because the paradoxical effects appear only when one considers results of experiments which do not actually take place. We suggest a new set of measurements in connection with Hardy's scheme, and show that when they are actually performed, they yield strange and surprising outcomes. More generally, we claim that counterfactual paradoxes point to a deeper structure inherent to quantum mechanics characterized by weak values (Aharonov Y, Botero A, Popescu S, Reznik B, Tollaksen J, Physics Letters A, 301 (3-4): 130-138, 2002).

  1. Retrospective study of recession of four horizontal rectus muscle in periodic alternating nystagmus

    PubMed Central

    Mimura, Osamu; Ishikawa, Hiroto; Kimura, Naoki; Kimura, Akiko; Borlongan, Cesar V

    2014-01-01

    Purpose Periodic alternating nystagmus (PAN) is a spontaneous horizontal nystagmus observed in disorders of the central nervous system. Patients with congenital PAN complain of oscillating vision at high rates. Medication is the first-choice treatment for PAN; however, clinicians still seek better therapy. The aim of this study was to evaluate outcomes of recession of four horizontal rectus muscle (R-FHR) in patients with congenital PAN. Patients and methods This study reports a retrospective case series of ten patients (seven males and three females; mean age 24.4±10.9) with congenital PAN who underwent R-FHR between 2007 and 2012, which was performed by the same surgeon at the Hyogo College of Medicine. Patients were evaluated for complications, recession amount, deviation angle, eye movements including a nystagmus amplitude, and visual acuity during pre- and post-operative periods. Results Pre-operatively, patients complained of oscillating vision, abnormal head posture, esotropia, and congenital superior oblique palsy. Post-operatively, changes from the previous observations of nystagmus amplitudes and abnormal head posture demonstrated a complete reversal in all patients. In addition, visual acuity determined with a Snellen chart improved in two patients. However, esotropia occurred in three patients who underwent additional strabismus surgery 2 days after R-FHR. R-FHR was particularly effective in eight patients who pre-operatively had periodic oscillating vision with a regular pattern of periodic nystagmus. Conclusion We demonstrated that ten patients with congenital PAN had improved vision following R-FHR, indicating that R-FHR was an effective procedure, especially in patients suffering PAN with periodic oscillating vision. PMID:25525330

  2. Predictive Factors Affecting Long-Term Outcome of Unilateral Lateral Rectus Recession

    PubMed Central

    Yang, Hee Kyung; Kim, Mi-Jin; Hwang, Jeong-Min

    2015-01-01

    Background There are few long-term outcome reports of unilateral lateral rectus (LR) recession for exotropia including a large number of subjects. Previous reports on unilateral LR recession commonly show extremely low rates of initial overcorrection and large exodrifts after surgery suggesting that the surgical dose may be increased. However, little is known of the long-term outcome of a large unilateral LR recession for exotropia. Objectives To determine long-term outcomes and predictive factors of recurrence after a large unilateral LR recession in patients with exotropia. Data Extraction Retrospective analysis was performed on 92 patients aged 3 to 17 years who underwent 10 mm unilateral LR recession for exotropia of ≤ 25 prism diopters (Δ) with prism and alternate cover testing and were followed up for more than 2 years after surgery. Final success rates within 10Δ of exophoria/tropia and 5Δ of esophoria/tropia at distance in the primary position, improvement in stereopsis and the predictive factors for recurrence were evaluated. Results At 24 months after surgery, 54% of patients had ocular alignment meeting the defined criteria of success, 45% had recurrence and 1% had overcorrection. After a mean follow-up of 39 months, 36% showed success, 63% showed recurrence and 1% resulted in overcorrection. The average time of recurrence was 23.4±14.7 months (range, 1–60 months) and the rate of recurrence per person-year was 23% after unilateral LR recession. Predictive factors of recurrence were a larger preoperative near angle of deviation (>16Δ) and larger initial postoperative exodeviation (>5Δ) at distance. Conclusions Long-term outcome of unilateral LR recession for exotropia showed low success rates with high recurrence, thus should be reserved for patients with a small preoperative near angle of exodeviation. PMID:26418819

  3. Inter-Rectus Distance Measurement Using Ultrasound Imaging: Does the Rater Matter?

    PubMed

    Keshwani, Nadia; Hills, Nicole; McLean, Linda

    2016-01-01

    Purpose: To investigate the interrater reliability of inter-rectus distance (IRD) measured from ultrasound images acquired at rest and during a head-lift task in parous women and to establish the standard error of measurement (SEM) and minimal detectable change (MDC) between two raters. Methods: Two physiotherapists independently acquired ultrasound images of the anterior abdominal wall from 17 parous women and measured IRD at four locations along the linea alba: at the superior border of the umbilicus, at 3 cm and 5 cm above the superior border of the umbilicus, and at 3 cm below the inferior border of the umbilicus. The interrater reliability of the IRD measurements was determined using intra-class correlation coefficients (ICCs). Bland-Altman analyses were used to detect bias between the raters, and SEM and MDC values were established for each measurement site. Results: When the two raters performed their own image acquisition and processing, ICCs(3,5) ranged from 0.72 to 0.91 at rest and from 0.63 to 0.96 during head lift, depending on the anatomical measurement site. Bland-Altman analyses revealed no systematic bias between the raters. SEM values ranged from 0.23 cm to 0.71 cm, and MDC values ranged from 0.64 cm to 1.97 cm. Conclusion: When using ultrasound imaging to measure IRD in women, it is acceptable for different therapists to compare IRDs between patients and within patients over time if IRD is measured above or below the umbilicus. Interrater reliability of IRD measurement is poorest at the level of the superior border of the umbilicus.

  4. Measurement of rectus femoris muscle velocities during patellar tendon jerk using vector tissue doppler imaging.

    PubMed

    Sikdar, Siddhartha; Lebiedowska, Maria; Eranki, Avinash; Garmirian, Lindsay; Damiano, Diane

    2009-01-01

    We have developed a vector tissue Doppler imaging (TDI) system based on a clinical scanner that can be used to measure muscle velocities independent of the direction of motion. This method overcomes the limitations of conventional Doppler ultrasound, which can only measure velocity components along the ultrasound beam. In this study, we utilized this method to investigate the rectus femoris muscle velocities during a patellar tendon jerk test. Our goal was to investigate whether the muscle elongation velocities during a brisk tendon tap fall within the normal range of velocities that are expected due to rapid stretch of limb segments. In a preliminary study, we recruited six healthy volunteers (three men and three women) following informed consent. The stretch reflex response to tendon tap was evaluated by measuring: (1) the tapping force using an accelerometer instrumented to the neurological hammer (2) the angular velocities of the knee extension and flexion using a electrogoniometer (3) reflex activation using electromyography (EMG) and (4) muscle elongation, extension and flexion velocities using vector TDI. The passive joint angular velocity was linearly related to the passive muscle elongation velocity (R(2)=0.88). The maximum estimated joint angular velocity corresponding to muscle elongation due to tendon tap was less than 8.25 radians/s. This preliminary study demonstrates the feasibility of vector TDI for measuring longitudinal muscle velocities and indicates that the muscle elongation velocities during a clinical tendon tap test are within the normal range of values for rapid limb stretch encountered in daily life. With further refinement, vector TDI could become a powerful method for quantitative evaluation of muscle motion in musculoskeletal disorders.

  5. Comparison of Astigmatism Induced by Combined Inferior Oblique Anterior Transposition Procedure and Lateral Rectus Recession Alone

    PubMed Central

    Eum, Sun Jung

    2016-01-01

    Purpose The purpose of this study is to compare the magnitude and axis of astigmatism induced by a combined inferior oblique (IO) anterior transposition procedure with lateral rectus (LR) recession versus LR recession alone. Methods Forty-six patients were retrospectively analyzed. The subjects were divided into two groups: those having concurrent inferior oblique muscle overaction (IOOA) and intermittent exotropia (group 1, 20 patients) and those having only intermittent exotropia as a control (group 2, 26 patients). Group 1 underwent combined anterior transposition of IO with LR recession and group 2 underwent LR recession alone. Induced astigmatism was defined as the difference between preoperative and postoperative astigmatism using double-angle vector analysis. Cylinder power, axis of induced astigmatism, and spherical equivalent were analyzed at 1 week, 1 month, and 3 months after surgery. Results Larger changes in the axis of induced astigmatism were observed in group 1, with 4.5° incyclotorsion, than in group 2 at 1 week after surgery (axis, 84.5° vs. 91°; p < 0.001). However, there was no statistically significant inter-group difference thereafter. Relaxation and rapid regression in the incyclotorsion of induced astigmatism were observed over-time. Spherical equivalent significantly decreased postoperatively at 1 month in both groups, indicating a myopic shift (p = 0.011 for group 1 and p = 0.019 for group 2) but did not show significant differences at 3 months after surgery (p = 0.107 for group 1 and p = 0.760 for group 2). Conclusions Combined IO anterior transposition procedures caused an increased change in the axis of induced astigmatism, including temporary incyclotorsion, during the first week after surgery. However, this significant difference was not maintained thereafter. Thus, combined IO surgery with LR recession does not seem to produce a sustained astigmatic change, which can be a potential risk factor of postoperative amblyopia or

  6. Reduced dopamine function within the medial shell of the nucleus accumbens enhances latent inhibition.

    PubMed

    Nelson, A J D; Thur, K E; Horsley, R R; Spicer, C; Marsden, C A; Cassaday, H J

    2011-03-01

    Latent inhibition (LI) manifests as poorer conditioning to a CS that has previously been presented without consequence. There is some evidence that LI can be potentiated by reduced mesoaccumbal dopamine (DA) function but the locus within the nucleus accumbens of this effect is as yet not firmly established. Experiment 1 tested whether 6-hydroxydopamine (6-OHDA)-induced lesions of DA terminals within the core and medial shell subregions of the nucleus accumbens (NAc) would enhance LI under conditions that normally disrupt LI in controls (weak pre-exposure). LI was measured in a thirst motivated conditioned emotional response procedure with 10 pre-exposures (to a noise CS) and 2 conditioning trials. The vehicle-injected and core-lesioned animals did not show LI and conditioned to the pre-exposed CS at comparable levels to the non-pre-exposed controls. 6-OHDA lesions to the medial shell, however, produced potentiation of LI, demonstrated across two extinction tests. In a subsequent experiment, haloperidol microinjected into the medial shell prior to conditioning similarly enhanced LI. These results underscore the dissociable roles of core and shell subregions of the NAc in mediating the expression of LI and indicate that reduced DA function within the medial shell leads to enhanced LI.

  7. [SECOT consensus on medial femorotibial osteoarthritis].

    PubMed

    Moreno, A; Silvestre, A; Carpintero, P

    2013-01-01

    A consensus, prepared by SECOT, is presented on the management of medial knee compartment osteoarthritis, in order to establish clinical criteria and recommendations directed at unifying the criteria in its management, dealing with the factors involved in the pathogenesis of medial femorotibial knee osteoarthritis, the usefulness of diagnostic imaging techniques, and the usefulness of arthroscopy. Conservative and surgical treatments are also analysed. The experts consulted showed a consensus (agreed or disagreed) in 65.8% of the items considered, leaving 14items where no consensus was found, which included the aetiopathogenesis of the osteoarthritis, the value of NMR in degenerative disease, the usefulness of COX-2 and the chondroprotective drugs, as well as on the ideal valgus tibial osteotomy technique.

  8. Medial Cochlear Efferent Function: A Theoretical Analysis

    NASA Astrophysics Data System (ADS)

    Mountain, David C.

    2011-11-01

    Since the discovery of the cochlear efferent system, many hypotheses have been put forth for its function. These hypotheses for its function range from protecting the cochlea from over stimulation to improving the detection of sounds in noise. It is known that the medial efferent system innervates the outer hair cells and that stimulation of this system reduces basilar membrane and auditory nerve sensitivity which suggests that this system acts to decrease the gain of the cochlear amplifier. Here I present modeling results as well as analysis of published experimental data that suggest that the function of the medial efferent reflex is to decrease the cochlear amplifier gain by just the right amount so that the nonlinearity in the basilar membrane response lines up perfectly with the inner hair cell nonlinear transduction process to produce a hair cell receptor potential that is proportional to the logarithm of the sound pressure level.

  9. Masseter and medial pterygoid muscle hypertrophy.

    PubMed

    Guruprasad, R; Rishi, Sudhirkumar; Nair, Preeti P; Thomas, Shaji

    2011-09-26

    Hypertrophy refers to an enlargement caused by an increase in the size but not in the number of cells. Generalised masticatory muscle hypertrophy may affect the temporalis muscle, masseters and medial pterygoids in a variety of combinations. Masseteric hypertrophy may present as either unilateral or bilateral painless swelling of unknown origin in the region of angle of mandible. It is a relatively rare condition and presents a diagnostic dilemma. While the history and clinical examination are important in differentiating this benign condition from parotid or dental pathology, they cannot necessarily exclude rare malignant lesion within the muscle. Advanced imaging modalities like CT and MRI are essential to confirm the diagnosis. Here the authors are reporting a unique case of masseter muscle hypertrophy along with medial pterygoid hypertrophy which was missed clinically but confirmed using CT and MRI.

  10. Osteoligamentous injuries of the medial ankle joint.

    PubMed

    Lötscher, P; Lang, T H; Zwicky, L; Hintermann, B; Knupp, M

    2015-12-01

    Injuries of the ankle joint have a high incidence in daily life and sports, thus, playing an important socioeconomic role. Therefore, proper diagnosis and adequate treatment are mandatory. While most of the ligament injuries around the ankle joint are treated conservatively, great controversy exists on how to treat deltoid ligament injuries in ankle fractures. Missed injuries and inadequate treatment of the medial ankle lead to inferior outcome with instability, progressive deformity, and ankle joint osteoarthritis.

  11. Medial septal lesion enhances general anesthesia response.

    PubMed

    Leung, L Stan; Ma, Jingyi; Shen, Bixia; Nachim, Ilan; Luo, Tao

    2013-09-01

    Electrolytic lesion of the medial septum, a basal forebrain nucleus that projects to the hippocampus, prolonged the emergence from general anesthesia in rats. Septal lesioned rats required a longer time to recover from a loss of righting reflex (LORR) and a loss of tail-pinch response after injectable (20 mg/kg i.p. pentobarbital, 5mg/kg i.v. propofol) or volatile (1.5% halothane, 2% isoflurane) anesthetic. When incremental doses of propofol were given i.p., septal lesioned rats as compared to control rats showed LORR at a lower dose of propofol. Similarly, when the rats were exposed to increasing concentrations of isoflurane, the percent of rats showing LORR was leftward shifted for lesioned rats as compared to control rats. Septal lesioned rats as compared to control rats showed decreased locomotor activity when exposed to 1.5% halothane. Lesion of the medial septum was confirmed by thionin-stained histological sections as well as loss of acetylcholinesterase (AchE) staining in the hippocampus, indicating a depletion of septohippocampal cholinergic afferents. Medial septal lesion resulted in a near complete loss of hippocampal theta rhythm during walking and a general decrease in power of the hippocampal EEG at all frequencies (0-100 Hz), during walking or immobility. It is concluded that lesion of medial septum, in part through a loss of septohippocampal cholinergic afferents, increased the anesthesia response to volatile and injectable general anesthetics, during both induction and emergence. It is suggested that the septohippocampal system participates in many components of general anesthesia including hypnosis, immobility, and analgesia.

  12. History of Weak Interactions

    DOE R&D Accomplishments Database

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  13. Transcatheter Arterial Embolization of Concurrent Spontaneous Hematomas of the Rectus Sheath and Psoas Muscle in Patients Undergoing Anticoagulation

    SciTech Connect

    Basile, Antonio; Medina, Jose Garcia; Mundo, Elena; Medina, Vicente Garcia; Leal, Rafael

    2004-11-15

    We report a case of concurrent rectus sheath and psoas hematomas in a patient undergoing anticoagulant therapy, treated by transcatheter arterial embolization (TAE) of inferior epigastric and lumbar arteries. Computed tomography (CT) demonstrated signs of active bleeding in two hematomas of the anterior and posterior abdominal walls. Transfemoral arteriogram confirmed the extravasation of contrast from the right inferior epigastric artery (RIEA). Indirect signs of bleeding were also found in a right lumbar artery (RLA). We successfully performed TAE of the feeding arteries. There have been few reports in the literature of such spontaneous hemorrhages in patients undergoing anticoagulation, successfully treated by TAE.

  14. Variations in the origin of the medial calcaneal nerve.

    PubMed

    Dellon, A Lee; Kim, Jaesuk; Spaulding, Cecily M

    2002-02-01

    Previous anatomic studies of the medial heel region were done on embalmed human cadavers. Here, the innervation of the medial heel region was studied by dissecting living tissue with the use of 3.5-power loupe magnification during decompression of the medial ankle for tarsal tunnel syndrome in 85 feet. The medial heel was found to be innervated by just one medial calcaneal nerve in 37% of the feet, by two medial calcaneal nerves in 41%, by three medial calcaneal nerves in 19%, and by four medial calcaneal nerves in 3%. An origin for a medial calcaneal nerve from the medial plantar nerve was found in 46% of the feet. This nerve most often innervates the skin of the posteromedial arch, where it is at risk for injury during calcaneal spur removal or plantar fasciotomy. Knowledge of the variations in location of the medial calcaneal nerves may prevent neuroma formation during surgery and provide insight into the variability of heel symptoms associated with tarsal tunnel syndrome.

  15. Percutaneous Partial Medial Collateral Ligament Release (PPMCLR) Does Not Result in Residual Medial Collateral Laxity (MCL)

    PubMed Central

    Hinton, M. Alan

    2015-01-01

    Objectives: The intra-articular posterior medial knee can be difficult to approach during arthroscopy. This is especially true for medial meniscal tears, medial meniscal repairs or medial meniscal transplantation. Various methods and instruments have been proposed to help with this approach. PPMCLR is one of these methods. This study found that this is a safe technique and does not result in measurable laxity of the MCL. Methods: 50 consecutive patients took part in the study. The patients were then randomized into a control or partial percutaneous release group (25 in each group). Prior to arthroscopy each patient had standardized 30 degree valgus stress radiograph performed. The MCL was stressed with the Telos Stress Device GA/III at 30 degrees of flexion; utilizing 150 Newton's of stress. The stress radiographs were measured independently for the maximal separation at the medial compartment. At six weeks the stress radiographs were repeated and the results again recorded. The postoperative care for each group was the same. Results: The results were then statistically evaluated using the, finding no radiographic evidence of residual laxity P<.005. There was also no difference in the control and PPMCLR group p<.0005. No patient complained of residual laxity. Patient follow up will be discussed. Conclusion: PPMCLR is an effective and safe method to reach the intra-articular posterior aspect of the knee during arthroscopy. PPMCLR does not result in measurable laxity of the MCL.

  16. Persistently active neurons in human medial frontal and medial temporal lobe support working memory.

    PubMed

    Kamiński, Jan; Sullivan, Shannon; Chung, Jeffrey M; Ross, Ian B; Mamelak, Adam N; Rutishauser, Ueli

    2017-04-01

    Persistent neural activity is a putative mechanism for the maintenance of working memories. Persistent activity relies on the activity of a distributed network of areas, but the differential contribution of each area remains unclear. We recorded single neurons in the human medial frontal cortex and medial temporal lobe while subjects held up to three items in memory. We found persistently active neurons in both areas. Persistent activity of hippocampal and amygdala neurons was stimulus-specific, formed stable attractors and was predictive of memory content. Medial frontal cortex persistent activity, on the other hand, was modulated by memory load and task set but was not stimulus-specific. Trial-by-trial variability in persistent activity in both areas was related to memory strength, because it predicted the speed and accuracy by which stimuli were remembered. This work reveals, in humans, direct evidence for a distributed network of persistently active neurons supporting working memory maintenance.

  17. Management of medial-sided knee injuries, part 1: medial collateral ligament.

    PubMed

    Marchant, Milford H; Tibor, Lisa M; Sekiya, Jon K; Hardaker, William T; Garrett, William E; Taylor, Dean C

    2011-05-01

    The medial collateral ligament complex is a primary stabilizer that combines static and dynamic resistance to direct valgus stress while contributing significant restraints to rotatory motion and anterior-posterior translation. Varying opinions exist among investigators regarding injury classification and treatment algorithms. Whereas most agree that the majority of isolated medial collateral ligament complex injuries can be treated nonoperatively, isolated injuries with chronic instability and multiligament injuries may require operative intervention. Substantial confounding factors are present within published reports, making comparative analyses and systematic review challenging. This review focuses on the anatomy and biomechanics of the medial structures of the knee; it discusses the clinical evaluation of complex injuries; and it reviews nonoperative and operative treatment methods.

  18. Post-ablative reconstruction of the medial canthus and medial orbital wall using conchal cartilage graft with three illustrative cases.

    PubMed

    Dagregorio, G; Darsonval, V

    2005-12-01

    When the medial third of the upper or lower eyelid has to be reconstructed after full-thickness tumour excision, we usually use Hübner tarsomarginal grafts, but when medial canthal lesions spread to the medial orbital wall without invading the orbital margin, conchal graft becomes our first surgical option. Previously reported solutions to this difficult problem are few and concern more directly medial orbital wall fractures. We found no article dealing specifically with the use of conchal graft in post-ablative reconstruction of the medial orbital wall. Nevertheless the concha presents great advantages over bone grafting or rib cartilage, because it is more flexible and malleable. And it is less prone to extrusion or infection as may be allografts implants. It is a very effective way to repair medial orbital defects, but graft reorientation must be perfect to match exactly the medial orbital wall concavity.

  19. "Tag-Team" Orbital and Strabismus Surgeries with Immediate Reconstruction After Tumor Excision Metastatic to the Inferior Rectus.

    PubMed

    Wu, Chris Y; Archer, Steven M; Kahana, Alon

    2016-01-01

    Carcinoid tumors are rare, slow-growing, low-grade neuroendocrine tumors with a propensity for orbital metastatic spread. The typical treatment paradigm for localized orbital disease involves excision, adjuvant radiotherapy, and/or receptor-targeted chemotherapy, followed by delayed evaluation for reconstructive strabismus surgery. We present a 58-year-old female patient with carcinoid tumor metastatic to the right inferior rectus muscle who presented with worsening binocular diplopia. The patient underwent coordinated "tag-team" orbital and strabismus surgeries that included excision of the right inferior rectus muscle to the annulus of Zinn followed immediately by reconstructive strabismus surgery. The patient required 1 additional strabismus surgery 1 year later. Follow up revealed no tumor recurrence at 4 years, and excellent binocular vision with good function. Deep orbital and strabismus surgeries, when performed simultaneously in a "tag-team" approach, may offer superior functional outcomes and improved patient quality of life, with expedited functional recovery. This approach may become a new treatment paradigm for surgical disease processes localized to the extraocular muscles.

  20. Real-time measurement of rectus femoris muscle kinematics during drop jump using ultrasound imaging: a preliminary study.

    PubMed

    Eranki, Avinash; Cortes, Nelson; Ferencek Gregurić, Zrinka; Kim, John J; Sikdar, Siddhartha

    2012-01-01

    We have developed an office based vector tissue Doppler imaging (vTDI) that can be used to quantitatively measure muscle kinematics using ultrasound. The goal of this preliminary study was to investigate if vTDI measures are repeatable and can be used robustly to measure and understand the kinematics of the rectus femoris muscle during a drop jump task. Data were collected from 8 healthy volunteers. Vector TDI along with a high speed camera video was used to better understand the dynamics of the drop jump. Our results indicate that the peak resultant vector velocity of the rectus femoris immediately following landing was repeatable across trials (intraclass correlation coefficient=0.9).The peak velocity had a relatively narrow range in 6 out of 8 subjects (48-62 cm/s), while in the remaining two subjects it exceeded 70 cm/s. The entire drop jump lasted for 1.45 0.27 seconds. The waveform of muscle velocity could be used to identify different phases of the jump. Also, the movement of the ultrasound transducer holder was minimal with peak deflection of 0.91 0.54 degrees over all trials. Vector TDI can be implemented in a clinical setting using an ultrasound system with a research interface to better understand the muscle kinematics in patients with ACL injuries.

  1. The lateral column lengthening and medial column stabilization procedures.

    PubMed

    Chi, T D; Toolan, B C; Sangeorzan, B J; Hansen, S T

    1999-08-01

    The results of medial column stabilization, lateral column lengthening, and combined medial and lateral procedures were reviewed in the treatment of adult acquired flatfoot secondary to posterior tibialis tendon insufficiency. All bony procedures were accompanied by transfer of the flexor digitorum longus tendon to the medial cuneiform or stump of the posterior tibialis tendon and tendoachilles lengthening or gastrocnemius recession. Medial column fusion was performed for naviculocuneiform and cuneiform first metatarsal sag; lateral column lengthening was performed for calcaneovalgus deformity with a flat pitch angle; and combined procedures were performed for complex combined deformities. At 1 to 4 year followup of 65 feet, 88% of the feet that had lateral column lengthening, 80% that had medial column stabilization, and 88% of the feet that had medial and lateral procedures had a decrease in pain or were pain free. The lateral talar first metatarsal angle improved by 16 degrees in the patients in the lateral column lengthening group, 20 degrees in the patients in the medial column stabilization group, and 24 degrees in the patients in the combined medial and lateral procedures group. The anteroposterior talonavicular coverage angle improved by 14 degrees in the patients in the lateral column lengthening group, 10 degrees in the patients in the medial column stabilization group, and 14 degrees in the patients in the combined medial and lateral procedures group. These techniques effectively correct deformity without disrupting the essential joints of the hindfoot and midfoot.

  2. Weak lensing and cosmology

    NASA Astrophysics Data System (ADS)

    Lombardi, Marco; Bertin, Giuseppe

    1999-02-01

    Recently, it has been shown that it is possible to reconstruct the projected mass distribution of a cluster from weak lensing provided that both the geometry of the universe and the probability distribution of galaxy redshifts are known; actually, when additional photometric data are taken to be available, the galaxy redshift distribution could be determined jointly with the cluster mass from the weak lensing analysis. In this paper we develop, in the spirit of a ``thought experiment,'' a method to constrain the geometry of the universe from weak lensing, provided that the redshifts of the source galaxies are measured. The quantitative limits and merits of the method are discussed analytically and with a set of simulations, in relation to point estimation, interval estimation, and test of hypotheses for homogeneous Friedmann-Lema\\^\\i tre models. The constraints turn out to be significant when a few thousand source galaxies are used.

  3. Medial unicondylar knee arthroplasty: technical pearls

    PubMed Central

    BONIFORTI, FILIPPO

    2015-01-01

    Unicondylar knee arthroplasty implantation is extremely demanding as the prosthesis needs to be integrated in the natural anatomy of the knee. It ensures the integrity of the natural knee kinematic. Some studies and registries data have shown lower success rate in comparison with total knee arthroplasty, and patient-related factors may have an impact on outcome. While, better results have been published by high volume centres. The indications for surgery should be reconsidered critically, even if medial osteoarthritis of the knee remains the most common. This article sets out the diagnostic, and surgical steps in order to fine tuning the unicompartmental replacement of the knee. PMID:26605256

  4. High-Frequency Resonance in the Gerbil Medial Superior Olive

    PubMed Central

    Mikiel-Hunter, Jason; Kotak, Vibhakar; Rinzel, John

    2016-01-01

    A high-frequency, subthreshold resonance in the guinea pig medial superior olive (MSO) was recently linked to the efficient extraction of spatial cues from the fine structure of acoustic stimuli. We report here that MSO neurons in gerbil also have resonant properties and, based on our whole-cell recordings and computational modeling, that a low-voltage-gated potassium current, IKLT, underlies the resonance. We show that resonance was lost following dynamic clamp replacement of IKLT with a leak conductance and in the model when voltage-gating of IKLT was suppressed. Resonance was characterized using small amplitude sinusoidal stimuli to generate impedance curves as typically done for linear systems analysis. Extending our study into the nonlinear, voltage-dependent regime, we increased stimulus amplitude and found, experimentally and in simulations, that the subthreshold resonant frequency (242Hz for weak stimuli) increased continuously to the resonant frequency for spiking (285Hz). The spike resonance of these phasic-firing (type III excitable) MSO neurons and of the model is of particular interest also because previous studies of resonance typically involved neurons/models (type II excitable, such as the standard Hodgkin-Huxley model) that can fire tonically for steady inputs. To probe more directly how these resonances relate to MSO neurons as slope-detectors, we presented periodic trains of brief, fast-rising excitatory post-synaptic potentials (EPSCs) to the model. While weak subthreshold EPSC trains were essentially low-pass filtered, resonance emerged as EPSC amplitude increased. Interestingly, for spike-evoking EPSC trains, the threshold amplitude at spike resonant frequency (317Hz) was lower than the single ESPC threshold. Our finding of a frequency-dependent threshold for repetitive brief EPSC stimuli and preferred frequency for spiking calls for further consideration of both subthreshold and suprathreshold resonance to fast and precise temporal processing

  5. FMRI signals associated with memory strength in the medial temporal lobes: a meta-analysis.

    PubMed

    Wais, Peter E

    2008-12-01

    To identify patterns of memory-related neural activity in the medial temporal lobes (MTL), a quantitative meta-analysis of 17 functional magnetic resonance imaging (fMRI) studies was performed. The analysis shows that increased activity in the hippocampus and the parahippocampal cortex predicts subsequent memory strength. During retrieval, activity in the hippocampus increases in association with strong memory. In the perirhinal cortex, increased activity predicts subsequent recognition, whether based on weak or strong memory, whereas during retrieval activity decreases below the level for misses in association with both weak and strong memory. The results are consistent with the claim that the hippocampus selectively subserves recollection, whereas adjacent structures subserve familiarity [Eichenbaum, H., Yonelinas, A., & Ranganath, C. (2007). The medial temporal lobe and recognition memory. The Annual Review of Neuroscience, 30, 123-152]. However, this conclusion depends on a specific dual-process theory of recognition memory that has been used to interpret the results. An alternative dual-process model holds that the behavioral methods used to differentiate recollection from familiarity instead separate strong memories from weak memories. When the fMRI data are interpreted in terms of the alternative theory, the fMRI results do not point to selective roles for the hippocampus or the adjacent MTL structures. The fMRI data alone cannot distinguish between these two models, so other methods are needed to resolve the issue.

  6. Medial knee joint loading increases in those who respond to hyaluronan injection for medial knee osteoarthritis.

    PubMed

    Briem, Kristin; Axe, Michael J; Snyder-Mackler, Lynn

    2009-11-01

    Knee osteoarthritis (OA) is a cause of decline in function and the medial compartment is often affected. Intraarticular injection of hyaluronic acid (HA) is indicated as a symptom modifying treatment with at least 6 months passing between consecutive injection series. The effects of HA injection on gait variables have not been extensively examined. Therefore, our objective was to investigate the effects of HA injection on gait in people with medial knee OA. Twenty-seven subjects were included; each was tested prior to treatment (baseline), no later than 3 weeks following the last injection (post-HA), and again 5 months after treatment ended (follow-up). Responder criteria were defined to identify responders and non-responders. Subjects underwent 3D gait analysis, muscle activity was sampled, and co-contraction indices were calculated. Responders experienced increased peak knee adduction moments post-HA, whereas non-responders did not. Improved self-report scores were associated with increased knee adduction moments and increased medial co-contraction. Pain relief may result in higher loading onto the already vulnerable medial compartment due to changes in lower limb mechanics and muscle activation patterns. Eventually this may result in a more rapid progression of joint deterioration.

  7. Medial subluxation of the patella without previous lateral retinacular release.

    PubMed

    Richman, N M; Scheller, A D

    1998-07-01

    This case presented a 17-year-old patient with persistent complaints localized to the right patellofemoral joint. Clinical examination demonstrated increased medial translation of the patella on manual stress. In contrast to previous published reports on medial patellar subluxation, this patient had not undergone prior lateral retinacular release. Arthroscopic examination documented medial tracking of the patella as well as excess medial translation. Imbrication of the patient's lateral patellar retinaculum centralized patella tracking and diminished medial translation on stress testing as observed arthroscopically and clinically. This case illustrates that medial patellar subluxation is a subtle problem that may be overlooked in the patient presenting with patellofemoral complaints and should be included in the differential diagnosis.

  8. Weaknesses in Underperforming Schools

    ERIC Educational Resources Information Center

    van de Grift, Wim; Houtveen, Thoni

    2007-01-01

    In some Dutch elementary schools, the average performance of students over several years is significantly below the level that could be expected of them. This phenomenon is known as "underperformance." The most important identifiable weaknesses that go along with this phenomenon are that (a) learning material offered at school is…

  9. [Medial epicondylitis. Etiology, diagnosis, therapeutic modalities].

    PubMed

    Tschantz, P; Meine, J

    1993-01-01

    Medial epicondylitis is rather uncommon, less frequent than external epicondylitis. For this reason, the diagnosis is thought of rather late. While taking the history, one should try to find out the possible causative effects. Symptoms of irritation of the cubital nerve, which are present in one out of five cases should be looked for. Several sports such as baseball, javelin or weight throwing, volleyball, climbing, tennis, golf, which need a strong flexion of the hand and fingers can induce this condition. However, in more than half of our patients, sports or professional activities were not in cause. The majority were housewives and do-it-yourself enthusiasts. Among our 55 operated cases, out of which few had professional or sports activities, we did not encounter during the operation the macroscopic tendinous lesions that are sometimes described by some authors. The treatment should be conservative in all cases. This includes rest, anti-inflammatory drugs, physiotherapy, muscular stretching, immobilisation in a cast, steroid infiltrations. One patient out of ten will have to be operated on. The operative techniques differ on some details, but they all include the desinsertion of the flexor muscles on the medial epicondyle. When there are clinical signs of irritation of the cubital nerve, it should be transposed anteriorly. The result of these operations is good in more than 90 per cent of the cases. However, a come back to professional sport can take as long as 8 months.

  10. The medial tibial stress syndrome. A cause of shin splints.

    PubMed

    Mubarak, S J; Gould, R N; Lee, Y F; Schmidt, D A; Hargens, A R

    1982-01-01

    The medial tibial stress syndrome is a symptom complex seen in athletes who complain of exercise-induced pain along the distal posterior-medial aspect of the tibia. Intramuscular pressures within the posterior compartments of the leg were measured in 12 patients with this disorder. These pressures were not elevated and therefore this syndrome is a not a compartment syndrome. Available information suggests that the medial tibial stress syndrome most likely represents a periostitis at this location of the leg.

  11. Cartilage Delamination Flap Mimicking a Torn Medial Meniscus

    PubMed Central

    Bin Abd Razak, Hamid Rahmatullah; Amit Kanta, Mitra

    2016-01-01

    We report a case of a chondral delamination lesion due to medial parapatellar plica friction syndrome involving the medial femoral condyle. This mimicked a torn medial meniscus in clinical and radiological presentation. Arthroscopy revealed a chondral delamination flap, which was debrided. Diagnosis of chondral lesions in the knee can be challenging. Clinical examination and MRI have good accuracy for diagnosis and should be used in tandem. Early diagnosis and treatment of chondral lesions are important to prevent progression to early osteoarthritis. PMID:28070434

  12. Medial Prefrontal-Medial Temporal Theta Phase Coupling in Dynamic Spatial Imagery.

    PubMed

    Kaplan, Raphael; Bush, Daniel; Bisby, James A; Horner, Aidan J; Meyer, Sofie S; Burgess, Neil

    2017-03-01

    Hippocampal-medial prefrontal interactions are thought to play a crucial role in mental simulation. Notably, the frontal midline/medial pFC (mPFC) theta rhythm in humans has been linked to introspective thought and working memory. In parallel, theta rhythms have been proposed to coordinate processing in the medial temporal cortex, retrosplenial cortex (RSc), and parietal cortex during the movement of viewpoint in imagery, extending their association with physical movement in rodent models. Here, we used noninvasive whole-head MEG to investigate theta oscillatory power and phase-locking during the 18-sec postencoding delay period of a spatial working memory task, in which participants imagined previously learned object sequences either on a blank background (object maintenance), from a first-person viewpoint in a scene (static imagery), or moving along a path past the objects (dynamic imagery). We found increases in 4- to 7-Hz theta power in mPFC when comparing the delay period with a preencoding baseline. We then examined whether the mPFC theta rhythm was phase-coupled with ongoing theta oscillations elsewhere in the brain. The same mPFC region showed significantly higher theta phase coupling with the posterior medial temporal lobe/RSc for dynamic imagery versus either object maintenance or static imagery. mPFC theta phase coupling was not observed with any other brain region. These results implicate oscillatory coupling between mPFC and medial temporal lobe/RSc theta rhythms in the dynamic mental exploration of imagined scenes.

  13. Medial and Lateral Discoid Menisci of Both Knees

    PubMed Central

    Kan, Hiroyuki; Arai, Yuji; Nakagawa, Shuji; Inoue, Hiroaki; Minami, Ginjiro; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2016-01-01

    Discoid menisci on both the medial and lateral sides are rare, and there are very few reports on cases involving both sides. We report a case of a 52-year-old female with medial and lateral discoid menisci in both knees. Arthroscopy revealed the lateral menisci of both knees were complete discoid menisci, and partial meniscectomy was performed. The medial menisci were incomplete discoid menisci, but there were no findings of abnormal mobility or injury; therefore, the medial menisci were observed without treatment. At six months postoperatively, her pain and range of motion restrictions disappeared. PMID:27894182

  14. Formation of independently revascularized bowel segments using the rectus abdominis muscle flap: a rat model for jejunal prefabrication.

    PubMed

    Tan, Bien-Keem; Chen, Hung-Chi; Wei, Fu-Chan; Ma, Shwu-Fan; Lan, Chyn-Tair; See, Lai-Chu; Wan, Yung-Liang

    2002-02-01

    Reconstruction of the pharyngoesophagus with free jejunal transfer is a major challenge when recipient neck vessels are absent because of previous surgery or irradiation. In such instances, jejunal transfer using a muscle flap as a "vascular carrier" may be a problem-solving alternative. Pretransfer vascularization of the jejunum is achieved by wrapping the muscle flap around the small bowel segment. After a short staging period, the mesenteric pedicle is divided and the bowel segment is transferred up to the neck based on its new blood supply. The objectives of this study were to develop an animal model for prefabricating independently revascularized jejunal segments using the rectus abdominis muscle flap and to determine the minimal time required for independent bowel survival. Twenty-four mature (500-g to 700-g) rats were divided into six experimental groups of four animals each. In each animal, a 1.5-cm segment of proximal jejunum was isolated on two jejunal arteries and wrapped with a superior pedicled rectus abdominis muscle flap. To determine the time of neovascular takeover, the mesenteric pedicles were ligated on postoperative day 2 (group I), day 3 (group II), day 4 (group III), day 5 (group IV), day 6 (group V), and day 7 (group VI). At the time of pedicle ligation, the composite flap was transposed to a new subcutaneous position. Viability of bowel was assessed according to gross appearance and histologic examination 48 hours after transfer. Complete survival of revascularized jejunum in 11 of 12 animals was obtained after pedicle ligation on postoperative day 5 and beyond (p < 0.0001, Fisher's exact test). These bowel segments demonstrated luminal patency, intact pink mucosa, mucus production, and visible peristalsis. Histologic examination showed healthy intestinal epithelium and tissue integration along the serosa-muscle interphase. In contrast, pedicle ligation on day 4 and earlier resulted in varying degrees of bowel necrosis characterized by

  15. Weak Finsler structures and the Funk weak metric

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Athanase; Troyanov, Marc

    2009-04-01

    We discuss general notions of metrics and of Finsler structures which we call weak metrics and weak Finsler structures. Any convex domain carries a canonical weak Finsler structure, which we call its tautological weak Finsler structure. We compute distances in the tautological weak Finsler structure of a domain and we show that these are given by the so-called Funk weak metric. We conclude the paper with a discussion of geodesics, of metric balls and of convexity properties of the Funk weak metric.

  16. Successful extraocular muscle re-resection for a strabismus surgery complication: a "snapped" [severed, inadvertently] and retrieved inferior rectus muscle: a case report.

    PubMed

    Akbari, Mahammad Reza; Jafari, Alireza Keshtcar; Ameri, Ahmed; Anvari, Faramarz; Eshraghi, Bahram; Masoomian, Babak

    2012-01-01

    A 26- year-old woman who had a left head tilt since childhood was undergoing left inferior rectus resection to correct her left inferior rectus paresis. During the surgery, when the inferior rectus was isolated and engaged with an eye muscle hook, the muscle tore (snapped) completely into two pieces, 8 mm posterior to insertion. Fortunately, we were able to find the proximal portion of the muscle and, after a 3 mm resection, of the distal yet attached 8 mm portion, the proximal and distal portions were sutured together with a non-absorbable suture. After nine months followup there was significant diplopia, and the preoperative left head tilt and left hypertropia remained, so a left inferior rectus re-resection was done. At the end of 18 months followup after the second procedure there was no binocular deviation (strabismus) in primary position nor in any other gaze positions, but there was a mild ocular motility infraduction deficit present on left and down gaze.

  17. Weak Gravitational Lensing

    NASA Astrophysics Data System (ADS)

    Pires, Sandrine; Starck, Jean-Luc; Leonard, Adrienne; Réfrégier, Alexandre

    2012-03-01

    This chapter reviews the data mining methods recently developed to solve standard data problems in weak gravitational lensing. We detail the different steps of the weak lensing data analysis along with the different techniques dedicated to these applications. An overview of the different techniques currently used will be given along with future prospects. Until about 30 years ago, astronomers thought that the Universe was composed almost entirely of ordinary matter: protons, neutrons, electrons, and atoms. The field of weak lensing has been motivated by the observations made in the last decades showing that visible matter represents only about 4-5% of the Universe (see Figure 14.1). Currently, the majority of the Universe is thought to be dark, that is, does not emit electromagnetic radiation. The Universe is thought to be mostly composed of an invisible, pressure less matter - potentially relic from higher energy theories - called "dark matter" (20-21%) and by an even more mysterious term, described in Einstein equations as a vacuum energy density, called "dark energy" (70%). This "dark" Universe is not well described or even understood; its presence is inferred indirectly from its gravitational effects, both on the motions of astronomical objects and on light propagation. So this point could be the next breakthrough in cosmology. Today's cosmology is based on a cosmological model that contains various parameters that need to be determined precisely, such as the matter density parameter Omega_m or the dark energy density parameter Omega_lambda. Weak gravitational lensing is believed to be the most promising tool to understand the nature of dark matter and to constrain the cosmological parameters used to describe the Universe because it provides a method to directly map the distribution of dark matter (see [1,6,60,63,70]). From this dark matter distribution, the nature of dark matter can be better understood and better constraints can be placed on dark energy

  18. Medial perirhinal cortex disambiguates confusable objects.

    PubMed

    Kivisaari, Sasa L; Tyler, Lorraine K; Monsch, Andreas U; Taylor, Kirsten I

    2012-12-01

    Our brain disambiguates the objects in our cluttered visual world seemingly effortlessly, enabling us to understand their significance and to act appropriately. The role of anteromedial temporal structures in this process, particularly the perirhinal cortex, is highly controversial. In some accounts, the perirhinal cortex is necessary for differentiating between perceptually and semantically confusable objects. Other models claim that the perirhinal cortex neither disambiguates perceptually confusable objects nor plays a unique role in semantic processing. One major hurdle to resolving this central debate is the fact that brain damage in human patients typically encompasses large portions of the anteromedial temporal lobe, such that the identification of individual substructures and precise neuroanatomical locus of the functional impairments has been difficult. We tested these competing accounts in patients with Alzheimer's disease with varying degrees of atrophy in anteromedial structures, including the perirhinal cortex. To assess the functional contribution of each anteromedial temporal region separately, we used a detailed region of interest approach. From each participant, we obtained magnetic resonance imaging scans and behavioural data from a picture naming task that contrasted naming performance with living and non-living things as a way of manipulating perceptual and semantic confusability; living things are more similar to one another than non-living things, which have more distinctive features. We manually traced neuroanatomical regions of interest on native-space cortical surface reconstructions to obtain mean thickness estimates for the lateral and medial perirhinal cortex and entorhinal cortex. Mean cortical thickness in each region of interest, and hippocampal volume, were submitted to regression analyses predicting naming performance. Importantly, atrophy of the medial perirhinal cortex, but not lateral perirhinal cortex, entorhinal cortex or

  19. Composite weak bosons

    SciTech Connect

    Suzuki, M.

    1988-04-01

    Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.

  20. Weakly supervised glasses removal

    NASA Astrophysics Data System (ADS)

    Wang, Zhicheng; Zhou, Yisu; Wen, Lijie

    2015-03-01

    Glasses removal is an important task on face recognition, in this paper, we provide a weakly supervised method to remove eyeglasses from an input face image automatically. We choose sparse coding as face reconstruction method, and optical flow to find exact shape of glasses. We combine the two processes iteratively to remove glasses more accurately. The experimental results reveal that our method works much better than these algorithms alone, and it can remove various glasses to obtain natural looking glassless facial images.

  1. Anterior transposition of the inferior oblique muscle as the initial treatment of a snapped inferior rectus muscle.

    PubMed

    Aguirre-Aquino, B I; Riemann, C D; Lewis, H; Traboulsi, E I

    2001-02-01

    Snapping or tearing of an extraocular muscle refers to its rupture across its width, usually at the junction between muscle and tendon several millimeters behind the insertion. Tearing occurs during strabismus or retinal reattachment surgery, or after trauma. If the proximal end of the muscle cannot be located, transposition procedures are necessary to achieve ocular realignment. These surgical procedures carry the risk of anterior segment ischemia, especially in the elderly. Anterior transposition of the inferior oblique muscle has been used for the treatment of inferior oblique overaction, especially in the presence of a dissociated vertical deviation, and in patients with fourth nerve palsy. We transposed the inferior oblique muscle insertion in a 73-year-old woman with a snapped inferior rectus muscle.

  2. Multiple brain parenchymal neurocysticercosis with extraocular muscle cysticercosis affecting levator palpebral superioris and superior rectus complex: an unusual association

    PubMed Central

    Verma, Rajesh; Jaiswal, Anupam

    2013-01-01

    An 8-year-old girl presented to the neurology department with a complaint of insidious onset of left-sided ptosis and restricted elevation of the left eye. A CT scan orbit and brain revealed a ring-enhancing lesion in the levator palpebral superioris (LPS) and superior rectus (SR) muscle complex of the left eye and left parietal and right temporal region. She was started on steroid, followed by albendazole with improvement. The LPS/SR complex is the least common site of involvement among extraocular muscles in ocular cysticercosis. Specially, with brain neurocysticercosis (NCC), it is extremely rare. We report an unusual association of multiple brain NCC with ocular cysticercosis involving LPS and SR muscle. PMID:23355567

  3. An unusually medial axillary arch muscle.

    PubMed Central

    Dharap, A

    1994-01-01

    In the left upper limb of an adult male cadaver a triangular muscular slip, 3.5 cm long and 2.5 cm wide, arose from the lower border of latissimus dorsi just proximal to its tendon of insertion. It was inserted by a slender 6 cm long tendon mainly into the coracoid process of the scapula. Three short fibrous strands radiated from this slender tendon to gain attachments to pectoralis minor and the common tendon of origin of the short head of biceps brachii and coracobrachialis. In addition 2 flat tendinous bands attached the margin of this muscular slip to teres major. The thoracodorsal nerve entered the main bulk of latissimus dorsi close to the muscular slip but did not supply a separate branch to the latter. This is an axillary arch muscle in an unusually medial location. Images Fig. 1 Fig. 2 PMID:7928652

  4. Motor unit organization of human medial gastrocnemius.

    PubMed Central

    Garnett, R A; O'Donovan, M J; Stephens, J A; Taylor, A

    1979-01-01

    1. The properties of fifty-seven motor units in human medial gastrocnemius have been studied using controlled intramuscular microstimulation, glycogen depletion and muscle biopsy. 2. Motor units could be divided into three classes on the basis of their mechanical properties. Type S units were slow, small and fatigue resistant. Type FR units were fast, intermediate in size, and fatigue resistant. Type FF units were fast, large and fatigable. 3. Glycogen depletion of a number of type S and FF units revealed them to be composed of type 1 and type 2b muscle fibres respectively. 4. The results suggest that during slowly increasing voluntary contractions where units are recruited in order of size, type 1 and 2a muscle fibres would be employed at low force levels followed by type 2b muscle fibres in stronger contractions. Images Fig. 5 Fig. 6 PMID:430414

  5. Motor unit organization of human medial gastrocnemius.

    PubMed

    Garnett, R A; O'Donovan, M J; Stephens, J A; Taylor, A

    1979-02-01

    1. The properties of fifty-seven motor units in human medial gastrocnemius have been studied using controlled intramuscular microstimulation, glycogen depletion and muscle biopsy. 2. Motor units could be divided into three classes on the basis of their mechanical properties. Type S units were slow, small and fatigue resistant. Type FR units were fast, intermediate in size, and fatigue resistant. Type FF units were fast, large and fatigable. 3. Glycogen depletion of a number of type S and FF units revealed them to be composed of type 1 and type 2b muscle fibres respectively. 4. The results suggest that during slowly increasing voluntary contractions where units are recruited in order of size, type 1 and 2a muscle fibres would be employed at low force levels followed by type 2b muscle fibres in stronger contractions.

  6. Rectus sheath block for postoperative analgesia in patients with mesenteric vascular occlusion undergoing laparotomy: A randomized single-blinded study

    PubMed Central

    Elbahrawy, Khaled; El-Deeb, Alaa

    2016-01-01

    Background: Acute mesenteric ischemia is a life-threatening vascular emergency that requires early diagnosis, immediate anticoagulation, and intervention to restore mesenteric blood flow adequately. Aims: To investigate the effect of rectus sheath block (RSB) for postoperative analgesia in patients with mesenteric vascular occlusion. Settings and Design: Forty patients with mesenteric vascular occlusion, American Society of Anesthesiologists physical status I or II or III, scheduled for laparotomy were enrolled in this study. Subjects and Methods: Patients were randomized into two groups; control group (C Group) and rectus block group (RB Group). In both groups, general anesthesia was induced fentanyl 1 μg/kg with sleeping dose of propofol and 0.15 mg/kg cisatracurium. Then, anesthesia was maintained with sevoflurane in oxygen 100%. In RB Group, under aseptic condition, RSB guided by ultrasound was performed. Surgery is then continued and intravenous fentanyl patient-controlled analgesia pump started. Postoperative pain, sedation, and opioid side effects were assessed. Statistical Analysis Used: Statistical analysis was done using Statistical Package for Social Sciences (SPSS 19.0, Chicago, IL, USA). Results: Patients in the RB Group consumed statistically significant less opioid in comparison to control group either intraoperatively or postoperatively. Mean pain scores were statistically significant less in RB Group than in the control group at 2, 4, and 6 h postoperatively. Sedation score, incidence of nausea and vomiting were statistically significant less in the RB Group in comparison to control group. More patients’ satisfaction was reported in the RB Group. Conclusions: Ultrasound-guided RSB resulted in postoperative reduction of pain scores and opioid consumption compared with general anesthesia alone. Moreover, RSB was associated with better patient satisfaction and less nausea and vomiting. PMID:27746544

  7. Medial septum regulates the hippocampal spatial representation

    PubMed Central

    Mamad, Omar; McNamara, Harold M.; Reilly, Richard B.; Tsanov, Marian

    2015-01-01

    The hippocampal circuitry undergoes attentional modulation by the cholinergic medial septum. However, it is unclear how septal activation regulates the spatial properties of hippocampal neurons. We investigated here what is the functional effect of selective-cholinergic and non-selective septal stimulation on septo-hippocampal system. We show for the first time selective activation of cholinergic cells and their differential network effect in medial septum of freely-behaving transgenic rats. Our data show that depolarization of cholinergic septal neurons evokes frequency-dependent response from the non-cholinergic septal neurons and hippocampal interneurons. Our findings provide vital evidence that cholinergic effect on septo-hippocampal axis is behavior-dependent. During the active behavioral state the activation of septal cholinergic projections is insufficient to evoke significant change in the spiking of the hippocampal neurons. The efficiency of septo-hippocampal processing during active exploration relates to the firing patterns of the non-cholinergic theta-bursting cells. Non-selective septal theta-burst stimulation resets the spiking of hippocampal theta cells, increases theta synchronization, entrains the spiking of hippocampal place cells, and tunes the spatial properties in a timing-dependent manner. The spatial properties are augmented only when the stimulation is applied in the periphery of the place field or 400–650 ms before the animals approached the center of the field. In summary, our data show that selective cholinergic activation triggers a robust network effect in the septo-hippocampal system during inactive behavioral state, whereas the non-cholinergic septal activation regulates hippocampal functional properties during explorative behavior. Together, our findings uncover fast septal modulation on hippocampal network and reveal how septal inputs up-regulate and down-regulate the encoding of spatial representation. PMID:26175674

  8. Medial septum regulates the hippocampal spatial representation.

    PubMed

    Mamad, Omar; McNamara, Harold M; Reilly, Richard B; Tsanov, Marian

    2015-01-01

    The hippocampal circuitry undergoes attentional modulation by the cholinergic medial septum. However, it is unclear how septal activation regulates the spatial properties of hippocampal neurons. We investigated here what is the functional effect of selective-cholinergic and non-selective septal stimulation on septo-hippocampal system. We show for the first time selective activation of cholinergic cells and their differential network effect in medial septum of freely-behaving transgenic rats. Our data show that depolarization of cholinergic septal neurons evokes frequency-dependent response from the non-cholinergic septal neurons and hippocampal interneurons. Our findings provide vital evidence that cholinergic effect on septo-hippocampal axis is behavior-dependent. During the active behavioral state the activation of septal cholinergic projections is insufficient to evoke significant change in the spiking of the hippocampal neurons. The efficiency of septo-hippocampal processing during active exploration relates to the firing patterns of the non-cholinergic theta-bursting cells. Non-selective septal theta-burst stimulation resets the spiking of hippocampal theta cells, increases theta synchronization, entrains the spiking of hippocampal place cells, and tunes the spatial properties in a timing-dependent manner. The spatial properties are augmented only when the stimulation is applied in the periphery of the place field or 400-650 ms before the animals approached the center of the field. In summary, our data show that selective cholinergic activation triggers a robust network effect in the septo-hippocampal system during inactive behavioral state, whereas the non-cholinergic septal activation regulates hippocampal functional properties during explorative behavior. Together, our findings uncover fast septal modulation on hippocampal network and reveal how septal inputs up-regulate and down-regulate the encoding of spatial representation.

  9. Medial pivot knee in primary total knee arthroplasty.

    PubMed

    Atzori, Francesco; Salama, Wael; Sabatini, Luigi; Mousa, Shazly; Khalefa, Abdelrahman

    2016-01-01

    Total knee arthroplasty (TKA) with a medial pivot design was developed in order to mimic normal knee kinematics; the highly congruent medial compartment implant should improve clinical results and decrease contact stresses. Clinical and radiographic mid-term outcomes are satisfactory, but we need other studies to evaluate long-term results and indications for unusual cases.

  10. Weakly broken galileon symmetry

    SciTech Connect

    Pirtskhalava, David; Santoni, Luca; Trincherini, Enrico; Vernizzi, Filippo

    2015-09-01

    Effective theories of a scalar ϕ invariant under the internal galileon symmetryϕ→ϕ+b{sub μ}x{sup μ} have been extensively studied due to their special theoretical and phenomenological properties. In this paper, we introduce the notion of weakly broken galileon invariance, which characterizes the unique class of couplings of such theories to gravity that maximally retain their defining symmetry. The curved-space remnant of the galileon’s quantum properties allows to construct (quasi) de Sitter backgrounds largely insensitive to loop corrections. We exploit this fact to build novel cosmological models with interesting phenomenology, relevant for both inflation and late-time acceleration of the universe.

  11. `Weak A' phenotypes

    PubMed Central

    Cartron, J. P.; Gerbal, A.; Hughes-Jones, N. C.; Salmon, C.

    1974-01-01

    Thirty-five weak A samples including fourteen A3, eight Ax, seven Aend, three Am and three Ae1 were studied in order to determine their A antigen site density, using an IgG anti-A labelled with 125I. The values obtained ranged between 30,000 A antigen sites for A3 individuals, and 700 sites for the Ae1 red cells. The hierarchy of values observed made it possible to establish a quantitative relationship between the red cell agglutinability of these phenotypes measured under standard conditions, and their antigen site density. PMID:4435836

  12. The medial scaffold of 3D unorganized point clouds.

    PubMed

    Leymarie, Frederic F; Kimia, Benjamin B

    2007-02-01

    We introduce the notion of the medial scaffold, a hierarchical organization of the medial axis of a 3D shape in the form of a graph constructed from special medial curves connecting special medial points. A key advantage of the scaffold is that it captures the qualitative aspects of shape in a hierarchical and tightly condensed representation. We propose an efficient and exact method for computing the medial scaffold based on a notion of propagation along the scaffold itself, starting from initial sources of the flow and constructing the scaffold during the propagation. We examine this method specifically in the context of an unorganized cloud of points in 3D, e.g., as obtained from laser range finders, which typically involve hundreds of thousands of points, but the ideas are generalizable to data arising from geometrically described surface patches. The computational bottleneck in the propagation-based scheme is in finding the initial sources of the flow. We thus present several ideas to avoid the unnecessary consideration of pairs of points which cannot possibly form a medial point source, such as the "visibility" of a point from another given a third point and the interaction of clusters of points. An application of using the medial scaffold for the representation of point samplings of real-life objects is also illustrated.

  13. Weakly relativistic plasma expansion

    SciTech Connect

    Fermous, Rachid Djebli, Mourad

    2015-04-15

    Plasma expansion is an important physical process that takes place in laser interactions with solid targets. Within a self-similar model for the hydrodynamical multi-fluid equations, we investigated the expansion of both dense and under-dense plasmas. The weakly relativistic electrons are produced by ultra-intense laser pulses, while ions are supposed to be in a non-relativistic regime. Numerical investigations have shown that relativistic effects are important for under-dense plasma and are characterized by a finite ion front velocity. Dense plasma expansion is found to be governed mainly by quantum contributions in the fluid equations that originate from the degenerate pressure in addition to the nonlinear contributions from exchange and correlation potentials. The quantum degeneracy parameter profile provides clues to set the limit between under-dense and dense relativistic plasma expansions at a given density and temperature.

  14. Optogenetic dissection of medial prefrontal cortex circuitry

    PubMed Central

    Riga, Danai; Matos, Mariana R.; Glas, Annet; Smit, August B.; Spijker, Sabine; Van den Oever, Michel C.

    2014-01-01

    The medial prefrontal cortex (mPFC) is critically involved in numerous cognitive functions, including attention, inhibitory control, habit formation, working memory and long-term memory. Moreover, through its dense interconnectivity with subcortical regions (e.g., thalamus, striatum, amygdala and hippocampus), the mPFC is thought to exert top-down executive control over the processing of aversive and appetitive stimuli. Because the mPFC has been implicated in the processing of a wide range of cognitive and emotional stimuli, it is thought to function as a central hub in the brain circuitry mediating symptoms of psychiatric disorders. New optogenetics technology enables anatomical and functional dissection of mPFC circuitry with unprecedented spatial and temporal resolution. This provides important novel insights in the contribution of specific neuronal subpopulations and their connectivity to mPFC function in health and disease states. In this review, we present the current knowledge obtained with optogenetic methods concerning mPFC function and dysfunction and integrate this with findings from traditional intervention approaches used to investigate the mPFC circuitry in animal models of cognitive processing and psychiatric disorders. PMID:25538574

  15. Subspecialization in the human posterior medial cortex

    PubMed Central

    Bzdok, Danilo; Heeger, Adrian; Langner, Robert; Laird, Angela R.; Fox, Peter T.; Palomero-Gallagher, Nicola; Vogt, Brent A.; Zilles, Karl; Eickhoff, Simon B.

    2014-01-01

    The posterior medial cortex (PMC) is particularly poorly understood. Its neural activity changes have been related to highly disparate mental processes. We therefore investigated PMC properties with a data-driven exploratory approach. First, we subdivided the PMC by whole-brain coactivation profiles. Second, functional connectivity of the ensuing PMC regions was compared by task-constrained meta-analytic coactivation mapping (MACM) and task-unconstrained resting-state correlations (RSFC). Third, PMC regions were functionally described by forward/reverse functional inference. A precuneal cluster was mostly connected to the intraparietal sulcus, frontal eye fields, and right temporo-parietal junction; associated with attention and motor tasks. A ventral posterior cingulate cortex (PCC) cluster was mostly connected to the ventromedial prefrontal cortex and middle left inferior parietal cortex (IPC); associated with facial appraisal and language tasks. A dorsal PCC cluster was mostly connected to the dorsomedial prefrontal cortex, anterior/posterior IPC, posterior midcingulate cortex, and left dorsolateral prefrontal cortex; associated with delay discounting. A cluster in the retrosplenial cortex was mostly connected to the anterior thalamus and hippocampus. Furthermore, all PMC clusters were congruently coupled with the default mode network according to task-constrained but not task-unconstrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. PMID:25462801

  16. A dysexecutive syndrome of the medial thalamus.

    PubMed

    Liebermann, Daniela; Ploner, Christoph J; Kraft, Antje; Kopp, Ute A; Ostendorf, Florian

    2013-01-01

    Thalamic stroke is associated with neurological and cognitive sequelae. Resulting neuropsychological deficits vary with the vascular territory involved. Whereas sensory, motor and memory deficits following thalamic stroke are comparatively well characterized, the exact relationship between executive dysfunction and thalamic damage remains more ambiguous. To assess the pattern of executive-cognitive deficits following thalamic stroke and its possible association with distinct thalamic nuclei, 19 patients with focal thalamic lesions were examined with high-resolution structural imaging and neuropsychological testing. Twenty healthy individuals served as controls. Patient MRIs were co-registered to an atlas of the human thalamus. Lesion overlap and subtraction analyses were used for lesion-to-symptom mapping. In eight patients (42.1%), neuropsychological assessment demonstrated a disproportionate deficit in the Wisconsin Card Sorting Test (WCST), while other executive and memory functions were much less affected. Subtraction analysis revealed an area in the left medial thalamus, mainly consisting of the centromedian and parafascicular nuclei (CM-Pf complex) that was damaged in these patients and spared in patients with normal WCST performance. Thus, damage to the CM-Pf complex may yield a distinct dysexecutive syndrome in which deficient maintenance and shifting between cognitive sets predominates. We hypothesize that the CM-Pf complex may contribute to maintenance and shifting of cognitive sets by virtue of its dense connections with the striatum. The pattern of executive dysfunction following thalamic stroke may vary considerably with lesion location.

  17. Behavior of the Linea Alba During a Curl-up Task in Diastasis Rectus Abdominis: An Observational Study.

    PubMed

    Lee, Diane; Hodges, Paul W

    2016-07-01

    Study Design Cross-sectional repeated measures. Background Rehabilitation of diastasis rectus abdominis (DRA) generally aims to reduce the inter-rectus distance (IRD). We tested the hypothesis that activation of the transversus abdominis (TrA) before a curl-up would reduce IRD narrowing, with less linea alba (LA) distortion/deformation, which may allow better force transfer between sides of the abdominal wall. Objectives This study investigated behavior of the LA and IRD during curl-ups performed naturally and with preactivation of the TrA. Methods Curl-ups were performed by 26 women with DRA and 17 healthy control participants using a natural strategy (automatic curl-up) and with TrA preactivation (TrA curl-up). Ultrasound images were recorded at 2 points above the umbilicus (U point and UX point). Ultrasound measures of IRD and a novel measure of LA distortion (distortion index: average deviation of the LA from the shortest path between the recti) were compared between 3 tasks (rest, automatic curl-up, TrA curl-up), between groups, and between measurement points (analysis of variance). Results Automatic curl-up by women with DRA narrowed the IRD from resting values (mean U-point between-task difference, -1.19 cm; 95% confidence interval [CI]: -1.45, -0.93; P<.001 and mean UX-point between-task difference, -0.51 cm; 95% CI: -0.69, -0.34; P<.001), but LA distortion increased (mean U-point between-task difference, 0.018; 95% CI: 0.0003, 0.041; P = .046 and mean UX-point between-task difference, 0.025; 95% CI: 0.004, 0.045; P = .02). Although TrA curl-up induced no narrowing or less IRD narrowing than automatic curl-up (mean U-point difference between TrA curl-up versus rest, -0.56 cm; 95% CI: -0.82, -0.31; P<.001 and mean UX-point between-task difference, 0.02 cm; 95% CI: -0.22, 0.19; P = .86), LA distortion was less (mean U-point between-task difference, -0.025; 95% CI: -0.037, -0.012; P<.001 and mean UX-point between-task difference, -0.021; 95% CI: -0.038, -0

  18. Weak neutral current chemistry

    SciTech Connect

    Mohan, R.

    1996-07-01

    Metal cluster organic complexes, neither atomic nor solid but in analogy to atomic nuclei and to mesoscopic systems, have unusual dynamics and catalytic properties. Organo-metal clusters as quintessence prebiotic enzymes could have originated the homochirality of the molecules from achiral precursors, controlled from the atomic-nucleus, with the initial product itself serving subsequently as chiral auxiliary transferring and amplifying the chirality in the autocatalytic process now. High resolution spectroscopic studies of diatomic molecules beginning now may lead to upper estimates of the interaction strength of weak neutral currents (WNG) with valence electrons of metal clusters and suggest kinetic pathways to dynamic symmetry breaking in the asymmetric synthesis of chiral molecules. An estimate of 10{sup {minus}5} kT (thousand times larger than for radiolysis) for the parity violating energy (PVE) could be sufficient to run an entropy driven spin-catalyzed asymmetric synthesis. Expect then, wherever there are metal clusters in interstellar dust or under the sea chiral molecular production. {copyright} {ital 1996 American Institute of Physics.}

  19. Weak neutral current chemistry

    NASA Astrophysics Data System (ADS)

    Mohan, R.

    1996-07-01

    Metal cluster organic complexes, neither atomic nor solid but in analogy to atomic nuclei and to mesoscopic systems, have unusual dynamics and catalytic properties. Organo-metal clusters as quintessence prebiotic enzymes could have originated the homochirality of the molecules from achiral precursors, controlled from the atomic-nucleus, with the initial product itself serving subsequently as chiral auxiliary transferring and amplifying the chirality in the autocatalytic process now. High resolution spectroscopic studies of diatomic molecules beginning now may lead to upper estimates of the interaction strength of weak neutral currents (WNG) with valence electrons of metal clusters and suggest kinetic pathways to dynamic symmetry breaking in the asymmetric synthesis of chiral molecules. An estimate of 10-5 kT (thousand times larger than for radiolysis) for the parity violating energy (PVE) could be sufficient to run an entropy driven spin-catalyzed asymmetric synthesis. Expect then, wherever there are metal clusters in interstellar dust or under the sea chiral molecular production.

  20. Photocopy of photograph in Fitzsimons Army Medial Center Real Property ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph in Fitzsimons Army Medial Center Real Property Book (green cloth cover), south and west sides. - Fitzsimons General Hospital, Officers Quarters, Northeast Corner of West Harlow Avenue & North Seventh Street, Aurora, Adams County, CO

  1. Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test.

    PubMed

    Vigotsky, Andrew D; Lehman, Gregory J; Contreras, Bret; Beardsley, Chris; Chung, Bryan; Feser, Erin H

    2015-01-01

    Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson's r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = -1.39° (-5.53, +2.75); t(22) = -0.70; p = 0.4933; Cohen's d = - 0.15 (-0.58, 0.29)) or rectus femoris length (change = -0.005 (-0.013, +0.003); t(22) = -1.30; p = 0.2070; Cohen's d = - 0.27 (-0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol.

  2. Evaluation of three-dimensional printing for internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach: a preliminary report

    PubMed Central

    Zeng, Canjun; Xiao, Jidong; Wu, Zhanglin; Huang, Wenhua

    2015-01-01

    Objective: The aim of this study is to evaluate the efficacy and feasibility of three-dimensional printing (3D printing) assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach. Methods: A total of 38 patients with unstable pelvic fractures were analyzed retrospectively from August 2012 to February 2014. All cases were treated operatively with internal fixation assisted by three-dimensional printing from minimal invasive para-rectus abdominis approach. Both preoperative CT and three-dimensional reconstruction were performed. Pelvic model was created by 3D printing. Data including the best entry points, plate position and direction and length of screw were obtained from simulated operation based on 3D printing pelvic model. The diaplasis and internal fixation were performed by minimal invasive para-rectus abdominis approach according to the optimized dada in real surgical procedure. Matta and Majeed score were used to evaluate currative effects after operation. Results: According to the Matta standard, the outcome of the diaplasis achieved 97.37% with excellent and good. Majeed assessment showed 94.4% with excellent and good. The imageological examination showed consistency of internal fixation and simulated operation. The mean operation time was 110 minutes, mean intraoperative blood loss 320 ml, and mean incision length 6.5 cm. All patients have achieved clinical healing, with mean healing time of 8 weeks. Conclusion: Three-dimensional printing assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach is feasible and effective. This method has the advantages of trauma minimally, bleeding less, healing rapidly and satisfactory reduction, and worthwhile for spreading in clinical practice. PMID:26550226

  3. Selective lengthening of the psoas and rectus femoris and preservation of the iliacus for flexion deformity of the hip in cerebral palsy patients.

    PubMed

    Matsuo, T; Hara, H; Tada, S

    1987-01-01

    Between 1978 and 1983, 52 Japanese patients with cerebral palsy underwent operative correction of flexion deformity of the hip. The results of lengthening of the psoas, rectus femoris, and proximal hamstrings were satisfactory. The iliacus was left intact. Improvement in gait and activities of daily living was attained. Concentric reduction was obtained in 27 of 33 dislocated or subluxated hips. Sitting and perineal care were facilitated, and pain was alleviated. We conclude that preservation of the iliacus is important.

  4. Medial tibial stress syndrome: a critical review.

    PubMed

    Moen, Maarten H; Tol, Johannes L; Weir, Adam; Steunebrink, Miriam; De Winter, Theodorus C

    2009-01-01

    Medial tibial stress syndrome (MTSS) is one of the most common leg injuries in athletes and soldiers. The incidence of MTSS is reported as being between 4% and 35% in military personnel and athletes. The name given to this condition refers to pain on the posteromedial tibial border during exercise, with pain on palpation of the tibia over a length of at least 5 cm. Histological studies fail to provide evidence that MTSS is caused by periostitis as a result of traction. It is caused by bony resorption that outpaces bone formation of the tibial cortex. Evidence for this overloaded adaptation of the cortex is found in several studies describing MTSS findings on bone scan, magnetic resonance imaging (MRI), high-resolution computed tomography (CT) scan and dual energy x-ray absorptiometry. The diagnosis is made based on physical examination, although only one study has been conducted on this subject. Additional imaging such as bone, CT and MRI scans has been well studied but is of limited value. The prevalence of abnormal findings in asymptomatic subjects means that results should be interpreted with caution. Excessive pronation of the foot while standing and female sex were found to be intrinsic risk factors in multiple prospective studies. Other intrinsic risk factors found in single prospective studies are higher body mass index, greater internal and external ranges of hip motion, and calf girth. Previous history of MTSS was shown to be an extrinsic risk factor. The treatment of MTSS has been examined in three randomized controlled studies. In these studies rest is equal to any intervention. The use of neoprene or semi-rigid orthotics may help prevent MTSS, as evidenced by two large prospective studies.

  5. GABAergic Projections from the Medial Septum Selectively Inhibit Interneurons in the Medial Entorhinal Cortex

    PubMed Central

    Gonzalez-Sulser, Alfredo; Parthier, Daniel; Candela, Antonio; McClure, Christina; Pastoll, Hugh; Garden, Derek; Sürmeli, Gülşen

    2014-01-01

    The medial septum (MS) is required for theta rhythmic oscillations and grid cell firing in the medial entorhinal cortex (MEC). While GABAergic, glutamatergic, and cholinergic neurons project from the MS to the MEC, their synaptic targets are unknown. To investigate whether MS neurons innervate specific layers and cell types in the MEC, we expressed channelrhodopsin-2 in mouse MS neurons and used patch-clamp recording in brain slices to determine the response to light activation of identified cells in the MEC. Following activation of MS axons, we observed fast monosynaptic GABAergic IPSPs in the majority (>60%) of fast-spiking (FS) and low-threshold-spiking (LTS) interneurons in all layers of the MEC, but in only 1.5% of nonstellate principal cells (NSPCs) and in no stellate cells. We also observed fast glutamatergic responses to MS activation in a minority (<5%) of NSPCs, FS, and LTS interneurons. During stimulation of MS inputs at theta frequency (10 Hz), the amplitude of GABAergic IPSPs was maintained, and spike output from LTS and FS interneurons was entrained at low (25–60 Hz) and high (60–180 Hz) gamma frequencies, respectively. By demonstrating cell type-specific targeting of the GABAergic projection from the MS to the MEC, our results support the idea that the MS controls theta frequency activity in the MEC through coordination of inhibitory circuits. PMID:25505326

  6. GABAergic projections from the medial septum selectively inhibit interneurons in the medial entorhinal cortex.

    PubMed

    Gonzalez-Sulser, Alfredo; Parthier, Daniel; Candela, Antonio; McClure, Christina; Pastoll, Hugh; Garden, Derek; Sürmeli, Gülşen; Nolan, Matthew F

    2014-12-10

    The medial septum (MS) is required for theta rhythmic oscillations and grid cell firing in the medial entorhinal cortex (MEC). While GABAergic, glutamatergic, and cholinergic neurons project from the MS to the MEC, their synaptic targets are unknown. To investigate whether MS neurons innervate specific layers and cell types in the MEC, we expressed channelrhodopsin-2 in mouse MS neurons and used patch-clamp recording in brain slices to determine the response to light activation of identified cells in the MEC. Following activation of MS axons, we observed fast monosynaptic GABAergic IPSPs in the majority (>60%) of fast-spiking (FS) and low-threshold-spiking (LTS) interneurons in all layers of the MEC, but in only 1.5% of nonstellate principal cells (NSPCs) and in no stellate cells. We also observed fast glutamatergic responses to MS activation in a minority (<5%) of NSPCs, FS, and LTS interneurons. During stimulation of MS inputs at theta frequency (10 Hz), the amplitude of GABAergic IPSPs was maintained, and spike output from LTS and FS interneurons was entrained at low (25-60 Hz) and high (60-180 Hz) gamma frequencies, respectively. By demonstrating cell type-specific targeting of the GABAergic projection from the MS to the MEC, our results support the idea that the MS controls theta frequency activity in the MEC through coordination of inhibitory circuits.

  7. Medial entorhinal cortex and medial septum contribute to self-motion-based linear distance estimation.

    PubMed

    Jacob, Pierre-Yves; Gordillo-Salas, Marta; Facchini, Justine; Poucet, Bruno; Save, Etienne; Sargolini, Francesca

    2017-02-04

    Path integration is a navigation strategy that requires animals to integrate self-movements during exploration to determine their position in space. The medial entorhinal cortex (MEC) has been suggested to play a pivotal role in this process. Grid cells, head-direction cells, border cells as well as speed cells within the MEC collectively provide a dynamic representation of the animal position in space based on the integration of self-movements. All these cells are strongly modulated by theta oscillations, thus suggesting that theta rhythmicity in the MEC may be essential for integrating and coordinating self-movement information during navigation. In this study, we first show that excitotoxic MEC lesions, but not dorsal hippocampal lesions, impair the ability of rats to estimate linear distances based on self-movement information. Next, we report similar deficits following medial septum inactivation, which strongly impairs theta oscillations in the entorhinal-hippocampal circuits. Taken together, these findings demonstrate a major role of the MEC and MS in estimating distances to be traveled, and point to theta oscillations within the MEC as a neural mechanism responsible for the integration of information generated by linear self-displacements.

  8. The perforator-based conjoint (chimeric) medial Sural(MEDIAL GASTROCNEMIUS) free flap.

    PubMed

    Sano, Kazufumi; Hallock, Geoffrey G; Hamazaki, Masahiro; Daicyo, Yoshihiro

    2004-12-01

    The prototypical conjoint or so-called "chimeric" free flap heretofore has been composed of several large independent flaps, each supplied by a separate major branch, that ultimately arise from a common source vessel. The perforator-based type of chimeric flap is a relatively new concept, usually involving multiple muscle perforator flaps each based on a solitary musculocutaneous perforator, but still arising from the same "mother" vessel. This principle of split cutaneous perforator flaps has been now successfully adapted to the medial suralMEDIAL GASTROCNEMIUS perforator free flap on 2 separate occasions. As a chimeric flap, there was greater flexibility in insetting, and overall flap width may be larger but still narrow enough to allow primary donor site closure; and yet, by definition, only a single recipient site was needed for any microanastomoses. This is further proof that the perforator-based chimeric free flap may be an option for any muscle perforator flap donor site, so that potential donor territories for conjoint flaps have become virtually unlimited.

  9. A Case of Extrusion of a Solid Silicone Tire Migrating through the Superior Rectus Muscle with Aeromonas hydrophila Infection following a Scleral Buckling Procedure

    PubMed Central

    Makino, Shinji; Sato, Yukihiro

    2012-01-01

    To our knowledge, there are no reports of Aeromonas hydrophila infection after a scleral buckling procedure. Also, migration of a silicone explant element through the rectus muscles is extremely rare. Herein, we describe a case experiencing extrusion of a solid silicone tire migrating through the superior rectus muscle with Aeromonas hydrophila infection following a scleral buckling procedure. A 42-year-old man was referred to our hospital complaining of ocular pain and purulent discharge in his left eye which has persisted for several months. He had a history of bilateral rhegmatogenous retinal detachment which had been treated with scleral buckling. The left eye showed extrusion of the solid silicone buckle which had migrated through the superior rectus muscle and an infection in the upper quadrant of the sclera. The buckle was removed, and the patient was treated with antibiotics. After the removal of the buckle, the symptoms showed rapid amelioration and there was no recurrence of retinal detachment. Aeromonas hydrophila was isolated from the discharge and the removed explant. He used well water in daily life. In this case, the Aeromonas hydrophila infection of the extruded buckle might have originated from contaminated well water. PMID:23213585

  10. Development of estimation system of knee extension strength using image features in ultrasound images of rectus femoris

    NASA Astrophysics Data System (ADS)

    Murakami, Hiroki; Watanabe, Tsuneo; Fukuoka, Daisuke; Terabayashi, Nobuo; Hara, Takeshi; Muramatsu, Chisako; Fujita, Hiroshi

    2016-04-01

    The word "Locomotive syndrome" has been proposed to describe the state of requiring care by musculoskeletal disorders and its high-risk condition. Reduction of the knee extension strength is cited as one of the risk factors, and the accurate measurement of the strength is needed for the evaluation. The measurement of knee extension strength using a dynamometer is one of the most direct and quantitative methods. This study aims to develop a system for measuring the knee extension strength using the ultrasound images of the rectus femoris muscles obtained with non-invasive ultrasonic diagnostic equipment. First, we extract the muscle area from the ultrasound images and determine the image features, such as the thickness of the muscle. We combine these features and physical features, such as the patient's height, and build a regression model of the knee extension strength from training data. We have developed a system for estimating the knee extension strength by applying the regression model to the features obtained from test data. Using the test data of 168 cases, correlation coefficient value between the measured values and estimated values was 0.82. This result suggests that this system can estimate knee extension strength with high accuracy.

  11. Predictors of the Dose-Effect Relationship regarding Unilateral Inferior Rectus Muscle Recession in Patients with Thyroid Eye Disease.

    PubMed

    Takahashi, Yasuhiro; Kakizaki, Hirohiko

    2015-01-01

    Purpose. To evaluate whether inferior rectus muscle (IRM) thickness, the degree of adipose change in the IRM, smoking status, and the previous history of orbital radiotherapy can predict the dose-effect relationship regarding unilateral IRM recession in thyroid eye disease (TED). Methods. Twenty-five patients were retrospectively reviewed. We calculated the largest IRM cross-sectional area and evaluated the degree of adipose change in the IRM using magnetic resonance imaging. The degree of adipose change and smoking status were classified using grading scales (0-3); previous orbital radiotherapy was graded as 0 when a history was not available and 1 when it was available. The correlation between the dose-effect relationship and the hypothesized predictive factors was evaluated using stepwise multiple regression analysis. Results. The multiple regression model, with the exception of the history of the previous orbital radiotherapy, estimated a significant dose-effect relationship for the parameters evaluated (Y DOSE-EFFECT = 0.013X IRM AREA  - 0.222X ADIPOSE  - 0.102X SMOKING + 1.694; r = 0.668; adjusted r (2) = 0.367; P = 0.005). Conclusions. The dose-effect relationship regarding unilateral IRM recession in TED could be predicted using IRM thickness, degree of intramuscular adipose change, and smoking status but could not be predicted using the previous orbital radiotherapy history.

  12. Delayed lateral rectus palsy following resection of a pineal cyst in sitting position: direct or indirect compressive phenomenon?

    PubMed

    Stevens, Qualls E; Colen, Chaim B; Ham, Steven D; Kattner, Keith A; Sood, Sandeep

    2007-12-01

    A rare case of delayed lateral rectus palsy in a patient following resection of a pineal lesion in the sitting position is presented. Postoperative pneumocephalus is common following craniospinal surgical intervention in the sitting position. The sixth cranial nerve is frequently injured because of its prolonged intracranial course. A 13-year-old girl was evaluated for unremitting headaches. No focal deficits were demonstrated on neurological examination. Magnetic resonance imaging revealed a cystlike pineal region mass with peripheral enhancement following intravenous contrast administration. A supracerebellar infratentorial craniotomy was performed in the sitting position, and complete resection of the lesion was achieved. Her postoperative course was complicated by sixth nerve palsy on the third postoperative day. Her symptoms improved with conservative management. The occurrence of sixth cranial nerve palsy secondary to pneumocephalus is a rare entity. Even rarer is the report of this anomaly following craniotomy in the sitting position. This patient's symptoms manifested in a delayed fashion. Although uncommon, this complication should be considered in patients undergoing cranial or spinal surgical interventions in this position.

  13. Medial Patellofemoral Ligament Reconstruction Femoral Tunnel Accuracy

    PubMed Central

    Hiemstra, Laurie A.; Kerslake, Sarah; Lafave, Mark

    2017-01-01

    Background: Medial patellofemoral ligament (MPFL) reconstruction is a procedure aimed to reestablish the checkrein to lateral patellar translation in patients with symptomatic patellofemoral instability. Correct femoral tunnel position is thought to be crucial to successful MPFL reconstruction, but the accuracy of this statement in terms of patient outcomes has not been tested. Purpose: To assess the accuracy of femoral tunnel placement in an MPFL reconstruction cohort and to determine the correlation between tunnel accuracy and a validated disease-specific, patient-reported quality-of-life outcome measure. Study Design: Case series; Level of evidence, 4. Methods: Between June 2008 and February 2014, a total of 206 subjects underwent an MPFL reconstruction. Lateral radiographs were measured to determine the accuracy of the femoral tunnel by measuring the distance from the center of the femoral tunnel to the Schöttle point. Banff Patella Instability Instrument (BPII) scores were collected a mean 24 months postoperatively. Results: A total of 155 (79.5%) subjects had adequate postoperative lateral radiographs and complete BPII scores. The mean duration of follow-up (±SD) was 24.4 ± 8.2 months (range, 12-74 months). Measurement from the center of the femoral tunnel to the Schöttle point resulted in 143 (92.3%) tunnels being categorized as “good” or “ideal.” There were 8 failures in the cohort, none of which occurred in malpositioned tunnels. The mean distance from the center of the MPFL tunnel to the center of the Schöttle point was 5.9 ± 4.2 mm (range, 0.5-25.9 mm). The mean postoperative BPII score was 65.2 ± 22.5 (range, 9.2-100). Pearson r correlation demonstrated no statistically significant relationship between accuracy of femoral tunnel position and BPII score (r = –0.08; 95% CI, –0.24 to 0.08). Conclusion: There was no evidence of a correlation between the accuracy of MPFL reconstruction femoral tunnel in relation to the Schöttle point and

  14. Knee stabilization in patients with medial compartment knee osteoarthritis

    PubMed Central

    Lewek, Michael D.; Ramsey, Dan K.; Snyder-Mackler, Lynn; Rudolph, Katherine S.

    2005-01-01

    OBJECTIVE Individuals with medial knee osteoarthritis (MKOA) experience knee laxity and instability. Muscle stabilization strategies may influence the long term integrity of the joint. In this study we determined how individuals with medial knee OA respond to a rapid valgus knee movement to investigate the relationship between muscle stabilization strategies and knee instability. METHODS Twenty one subjects with MKOA and genu varum, and 19 control subjects were tested. Subjects stood with the test limb on a moveable platform that translated laterally to rapidly stress the knee’s medial periarticular structures and create a potentially destabilizing feeling at the knee joint. Knee motion and muscle responses were recorded. Subjects rated their knee instability with a self-report questionnaire about knee instability during daily activities. RESULTS Prior to plate movement the OA subjects demonstrated more medial muscle co-contraction (p=0.014). Following plate movement the OA subjects shifted less weight off the test limb (p = 0.013) and had more medial co-contraction (p=0.037). Those without instability had higher VMMH co-contraction than those who reported more instability (p=0.038). Knee stability correlated positively with VMMH co-contraction prior to plate movement (r = 0.459; p = 0.042). CONCLUSION This study demonstrates that individuals with MKOA attempt to stabilize the knee with greater medial muscle co-contraction in response to laxity that appears on only the medial side of the joint. This strategy presumably contributes to higher joint compression and could exacerbate joint destruction and needs to be altered to slow or stop the progression of the OA disease process. PMID:16142714

  15. Relationship between foot function and medial knee joint loading in people with medial compartment knee osteoarthritis

    PubMed Central

    2013-01-01

    Background Dynamic joint loading, particularly the external knee adduction moment (KAM), is an important surrogate measure for the medio-lateral distribution of force across the knee joint in people with knee osteoarthritis (OA). Foot motion may alter the load on the medial tibiofemoral joint and hence affect the KAM. Therefore, this study aimed to investigate the relationship between tibia, rearfoot and forefoot motion in the frontal and transverse planes and the KAM in people with medial compartment knee OA. Method Motion of the knee, tibia, rearfoot and forefoot and knee moments were evaluated in 32 patients with clinically and radiographically-confirmed OA, predominantly in the medial compartment. Pearson’s correlation coefficient was used to investigate the association between peak values of tibia, rearfoot and forefoot motion in the frontal and transverse planes and 1st peak KAM, 2nd peak KAM, and the knee adduction angular impulse (KAAI). Results Lateral tilt of the tibia was significantly associated with increased 1st peak KAM (r = 0.60, p < 0.001), 2nd peak KAM (r = 0.67, p = 0.001) and KAAI (r = 0.82, p = 0.001). Increased peak rearfoot eversion was significantly correlated with decreased 2nd peak KAM (r = 0.59, p < 0.001) and KAAI (r = 0.50, p = 0.004). Decreased rearfoot internal rotation was significantly associated with increased 2nd peak KAM (r = −0.44, p = 0.01) and KAAI (r = −0.38, p = 0.02), while decreased rearfoot internal rotation relative to the tibia was significantly associated with increased 2nd peak KAM (r = 0.43, p = 0.01). Significant negative correlations were found between peak forefoot eversion relative to the rearfoot and 2nd peak KAM (r = −0.53, p = 0.002) and KAAI (r = −0.51, p = 0.003) and between peak forefoot inversion and 2nd peak KAM (r = −0.54, p = 0.001) and KAAI (r = −0.48, p = 0.005). Conclusion Increased rearfoot

  16. Refinement of Neuronal Synchronization with Gamma Oscillations in the Medial Prefrontal Cortex after Adolescence

    PubMed Central

    de Almeida, Julián; Jourdan, Iván; Murer, Mario Gustavo; Belforte, Juan E.

    2013-01-01

    The marked anatomical and functional changes taking place in the medial prefrontal cortex (PFC) during adolescence set grounds for the high incidence of neuropsychiatric disorders with adolescent onset. Although circuit refinement through synapse pruning may constitute the anatomical basis for the cognitive differences reported between adolescents and adults, a physiological correlate of circuit refinement at the level of neuronal ensembles has not been demonstrated. We have recorded neuronal activity together with local field potentials in the medial PFC of juvenile and adult mice under anesthesia, which allowed studying local functional connectivity without behavioral or sensorial interference. Entrainment of pyramidal neurons and interneurons to gamma oscillations, but not to theta or beta oscillations, was reduced after adolescence. Interneurons were synchronized to gamma oscillations across a wider area of the PFC than pyramidal neurons, and the span of interneuron synchronization was shorter in adults than juvenile mice. Thus, transition from childhood to adulthood is characterized by reduction of the strength and span of neuronal synchronization specific to gamma oscillations in the mPFC. The more restricted and weak ongoing synchronization in adults may allow a more dynamic rearrangement of neuronal ensembles during behavior and promote parallel processing of information. PMID:23646166

  17. Grid-layout and theta-modulation of layer 2 pyramidal neurons in medial entorhinal cortex.

    PubMed

    Ray, Saikat; Naumann, Robert; Burgalossi, Andrea; Tang, Qiusong; Schmidt, Helene; Brecht, Michael

    2014-02-21

    Little is known about how microcircuits are organized in layer 2 of the medial entorhinal cortex. We visualized principal cell microcircuits and determined cellular theta-rhythmicity in freely moving rats. Non-dentate-projecting, calbindin-positive pyramidal cells bundled dendrites together and formed patches arranged in a hexagonal grid aligned to layer 1 axons, parasubiculum, and cholinergic inputs. Calbindin-negative, dentate-gyrus-projecting stellate cells were distributed across layer 2 but avoided centers of calbindin-positive patches. Cholinergic drive sustained theta-rhythmicity, which was twofold stronger in pyramidal than in stellate neurons. Theta-rhythmicity was cell-type-specific but not distributed as expected from cell-intrinsic properties. Layer 2 divides into a weakly theta-locked stellate cell lattice and spatiotemporally highly organized pyramidal grid. It needs to be assessed how these two distinct principal cell networks contribute to grid cell activity.

  18. Intestinal Transport of Weak Electrolytes

    PubMed Central

    Jackson, Michael J.; Shiau, Yih-Fu; Bane, Susan; Fox, Margaret

    1974-01-01

    A study has been made of the transmural fluxes of benzoic, phenylacetic, and pentanoic acids, benzylamine, hexylamine, and D-amphetamine across rat jejunum incubated in vitro. The M to S fluxes of the weak acids were greater than their corresponding S to M fluxes, and the S to M fluxes of the weak bases were larger than their M to S fluxes. These patterns of asymmetric movements were observed when the transmural electrical potential difference was clamped at 0 mV, and when the pH values of the mucosal and serosal fluids were identical. The effects of a weak acid on the fluxes of other weak electrolytes were qualitatively similar when the effector weak acid was added to the mucosal fluid, and when it was added to the serosal fluid. But the effects of a weak base on the fluxes of other weak electrolytes were dependent upon its location, and the interactions observed when the effector weak base was added to the mucosal fluid were qualitatively different than those seen when it was added to the serosal fluid. The interactions between weak electrolytes could readily be explained in terms of the function of a system of three compartments in series, in which the pH of the intermediate compartment is greater than that of the bulk phases. But these observations could not be explained in terms of an analogous system involving an intermediate compartment of low pH, or in terms of a carrier mediated system. The transport function of the three-compartment system can be described in the form of an equation, and it is found that a pH difference of less than 0.5 unit may explain our observations on weak electrolyte transport. PMID:4812635

  19. A pseudo-iatrogenic case of medial clavicular fracture

    PubMed Central

    Staal, Heleen Muriel; Willems, Willem Jacob

    2008-01-01

    Medial fractures are the least common type of clavicular fracture (2–10%). The patient is a 29-year-old gynaecology resident with hyper-laxity and sternoclavicular instability. The latter had been surgically stabilized with Dacron® tape, which eroded the bone causing an usura. Acute right shoulder pain occurred 10 years later. CT revealed medial clavicular stress fracture. After 4 weeks of conservative management, internal fixation followed. Five months postoperatively the patient performed all activities without pain. In this patient the weakened medial clavicle due to usura clearly played a role in both the site and nature of the fracture. Furthermore, CT is essential in arriving at the correct diagnosis. PMID:18427920

  20. A pseudo-iatrogenic case of medial clavicular fracture.

    PubMed

    Poelmann, Tibor Antonius Johannes; Staal, Heleen Muriel; Willems, Willem Jacob

    2008-04-01

    Medial fractures are the least common type of clavicular fracture (2-10%). The patient is a 29-year-old gynaecology resident with hyper-laxity and sternoclavicular instability. The latter had been surgically stabilized with Dacron((R)) tape, which eroded the bone causing an usura. Acute right shoulder pain occurred 10 years later. CT revealed medial clavicular stress fracture. After 4 weeks of conservative management, internal fixation followed. Five months postoperatively the patient performed all activities without pain. In this patient the weakened medial clavicle due to usura clearly played a role in both the site and nature of the fracture. Furthermore, CT is essential in arriving at the correct diagnosis.

  1. Traumatic fragmented medial coronoid process in a Chihuahua.

    PubMed

    Hadley, H S; Wheeler, J L; Manley, P A

    2009-01-01

    Fragmented medial coronoid process (FMCP) is a disease process that has not previously been reported in toy-breed dogs. This report describes a presumptive case of FMCP in a 14-month-old Chihuahua that was presented for evaluation approximately four weeks following acute onset of moderate lameness in the left forelimb. Definitive diagnosis of a fragmented medial coronoid process was based upon computed tomography (CT) scan. A CT scan also demonstrated moderate joint incongruity in the affected elbow. Surgical removal of the fragment and subtotal coronoidectomy were performed via a medial arthrotomy. An ulnar ostectomy was also performed to address joint incongruity. Histology of specimens removed at surgery did not demonstrate evidence of microdamage as characteristic of FMCP in large breed dogs, and instead, suggested that the fracture was acute and traumatic in nature. Rapid return to function was observed following surgery.

  2. Medial collateral ligament reconstruction in the baseball Pitcher's elbow.

    PubMed

    Erne, Holger C; Zouzias, Ioannis C; Rosenwasser, Melvin P

    2009-08-01

    Pitchers are prone to elbow injuries because of high and repetitive valgus stresses on the elbow. The anterior bundle of the medial ulnar collateral ligament (MCL) of the elbow is the primary restraint and is often attenuated with time, leading to functional incompetence and ultimate failure. Pitchers with a history of medial elbow pain, reduced velocity, and loss of command may have an MCL injury in evolution. Physical examination and imaging can confirm the diagnosis. Treatment begins with rest and activity modification. All medial elbow pain is not MCL injury. Surgery is considered only for talented athletes who wish to return to competitive play and may include elite scholastic and other collegiates and professionals. The technique for MCL reconstruction was first described in 1986. Many variations have been offered since then, which can result in predictable outcomes, allowing many to return to the same level of competitive play.

  3. Experimental investigations of weak definite and weak indefinite noun phrases.

    PubMed

    Klein, Natalie M; Gegg-Harrison, Whitney M; Carlson, Greg N; Tanenhaus, Michael K

    2013-08-01

    Definite noun phrases typically refer to entities that are uniquely identifiable in the speaker and addressee's common ground. Some definite noun phrases (e.g., the hospital in Mary had to go the hospital and John did too) seem to violate this uniqueness constraint. We report six experiments that were motivated by the hypothesis that these "weak definite" interpretations arise in "incorporated" constructions. Experiments 1-3 compared nouns that seem to allow for a weak definite interpretation (e.g., hospital, bank, bus, radio) with those that do not (e.g., farm, concert, car, book). Experiments 1 and 2 used an instruction-following task and picture-judgment task, respectively, to demonstrate that a weak definite need not uniquely refer. In Experiment 3 participants imagined scenarios described by sentences such as The Federal Express driver had to go to the hospital/farm. Scenarios following weak definite noun phrases were more likely to include conventional activities associated with the object, whereas following regular nouns, participants were more likely to imagine scenarios that included typical activities associated with the subject; similar effects were observed with weak indefinites. Experiment 4 found that object-related activities were reduced when the same subject and object were used with a verb that does not license weak definite interpretations. In Experiment 5, a science fiction story introduced an artificial lexicon for novel concepts. Novel nouns that shared conceptual properties with English weak definite nouns were more likely to allow weak reference in a judgment task. Experiment 6 demonstrated that familiarity for definite articles and anti-familiarity for indefinite articles applies to the activity associated with the noun, consistent with predictions made by the incorporation analysis.

  4. Experimental investigations of weak definite and weak indefinite noun phrases

    PubMed Central

    Klein, Natalie M.; Gegg-Harrison, Whitney M.; Carlson, Greg N.; Tanenhaus, Michael K.

    2013-01-01

    Definite noun phrases typically refer to entities that are uniquely identifiable in the speaker and addressee’s common ground. Some definite noun phrases (e.g. the hospital in Mary had to go the hospital and John did too) seem to violate this uniqueness constraint. We report six experiments that were motivated by the hypothesis that these “weak definite” interpretations arise in “incorporated” constructions. Experiments 1-3 compared nouns that seem to allow for a weak definite interpretation (e.g. hospital, bank, bus, radio) with those that do not (e.g. farm, concert, car, book). Experiments 1 and 2 used an instruction-following task and picture-judgment task, respectively, to demonstrate that a weak definite need not uniquely refer. In Experiment 3 participants imagined scenarios described by sentences such as The Federal Express driver had to go to the hospital/farm. The imagined scenarios following weak definite noun phrases were more likely to include conventional activities associated with the object, whereas following regular nouns, participants were more likely to imagine scenarios that included typical activities associated with the subject; similar effects were observed with weak indefinites. Experiment 4 found that object-related activities were reduced when the same subject and object were used with a verb that does not license weak definite interpretations. In Experiment 5, a science fiction story introduced an artificial lexicon for novel concepts. Novel nouns that shared conceptual properties with English weak definite nouns were more likely to allow weak reference in a judgment task. Experiment 6 demonstrated that familiarity for definite articles and anti- familiarity for indefinite articles applies to the activity associated with the noun, consistent with predictions made by the incorporation analysis. PMID:23685208

  5. Weak-shock reflection factors

    SciTech Connect

    Reichenbach, H.; Kuhl, A.L.

    1993-09-07

    The purpose of this paper is to compare reflection factors for weak shocks from various surfaces, and to focus attention on some unsolved questions. Three different cases are considered: square-wave planar shock reflection from wedges; square-wave planar shock reflection from cylinders; and spherical blast wave reflection from a planar surface. We restrict ourselves to weak shocks. Shocks with a Mach number of M{sub O} < 1.56 in air or with an overpressure of {Delta}{sub PI} < 25 psi (1.66 bar) under normal ambient conditions are called weak.

  6. Medial Meniscal Extrusion Relates to Cartilage Loss in Specific Femorotibial Subregions- Data from the Osteoarthritis Initiative

    PubMed Central

    Bloecker, K.; Wirth, W.; Guermazi, A.; Hunter, DJ; Resch, H.; Hochreiter, J.; Eckstein, F.

    2015-01-01

    Objective Medial meniscal extrusion is known to be related to structural progression of knee OA. However, it is unclear whether medial meniscal extrusion is more strongly associated with cartilage loss in certain medial femorotibial subregions than to others. Methods Segmentation of the medial tibial and femoral cartilage (baseline; 1-year follow-up) and the medial meniscus (baseline) was performed in 60 participants with frequent knee pain (age 61.3±9.2y, BMI 31.3±3.9 kg/m2) and with unilateral medial radiographic joint space narrowing (JSN) grade 1–3, using double echo steady state MR-images. Medial meniscal extrusion distance and extrusion area (%) between the external meniscal and tibial margin at baseline, and longitudinal medial cartilage loss in eight anatomical subregions were determined. Results A significant association (Pearson correlation coefficient) was seen between medial meniscus extrusion area in JSN knees and cartilage loss over one year throughout the entire medial femorotibial compartment. The strongest correlation was with cartilage loss in the external medial tibia (r=−0.34 [p<0.01] in JSN, and r=−0.30 [p=0.02] in noJSN knees). Conclusion Medial meniscus extrusion was associated with subsequent medial cartilage loss. The external medial tibial cartilage may be particularly vulnerable to thinning once the meniscus extrudes and its surface is “exposed” to direct, non-physiological, cartilage-cartilage contact. PMID:25988986

  7. Weak interactions and presupernova evolution

    SciTech Connect

    Aufderheide, M.B. State Univ. of New York . Dept. of Physics)

    1991-02-19

    The role of weak interactions, particularly electron capture and {beta}{sup {minus}} decay, in presupernova evolution is discussed. The present uncertainty in these rates is examined and the possibility of improving the situation is addressed. 12 refs., 4 figs.

  8. [Acute muscle weakness: differential diagnoses].

    PubMed

    Antoniuk, Sérgio A

    2013-09-06

    Acute muscle weakness, a common disorder in pediatrics, can occur from impairment of any part of the motor unit, including the upper motor neuron, lower motor neuron, peripheral nerve, neuromuscular junction or muscle. It usually manifests itself as an acute or hyperacute motor disorder of progressive or rapidly progressive course. Acute muscle weakness is a neuromuscular emergency, especially if it affects the respiratory or oropharyngeal musculature. The location of the motor weakness and associated neurological signs and symptoms usually indicate the location of the lesion. The onset, speed and clinical evolution, as well as other data from the patient's history, suggest the pathophysiological differential diagnosis. Successful treatment depends on the immediate and correct differential diagnosis. This paper presents the main differential diagnosis of main neuromuscular diseases that cause acute muscle weakness in children.

  9. Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test

    PubMed Central

    Lehman, Gregory J.; Contreras, Bret; Beardsley, Chris; Chung, Bryan; Feser, Erin H.

    2015-01-01

    Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson’s r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = −1.39° (−5.53, +2.75); t(22) = −0.70; p = 0.4933; Cohen’s d = − 0.15 (−0.58, 0.29)) or rectus femoris length (change = −0.005 (−0.013, +0.003); t(22) = −1.30; p = 0.2070; Cohen’s d = − 0.27 (−0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol. PMID:26421244

  10. [Application of three-dimensional printing personalized acetabular wing-plate in treatment of complex acetabular fractures via lateral-rectus approach].

    PubMed

    Mai, J G; Gu, C; Lin, X Z; Li, T; Huang, W Q; Wang, H; Tan, X Y; Lin, H; Wang, Y M; Yang, Y Q; Jin, D D; Fan, S C

    2017-03-01

    Objective: To investigate reduction and fixation of complex acetabular fractures using three-dimensional (3D) printing technique and personalized acetabular wing-plate via lateral-rectus approach. Methods: From March to July 2016, 8 patients with complex acetabular fractures were surgically managed through 3D printing personalized acetabular wing-plate via lateral-rectus approach at Department of Orthopedics, the Third Affiliated Hospital of Southern Medical University. There were 4 male patients and 4 female patients, with an average age of 57 years (ranging from 31 to 76 years). According to Letournel-Judet classification, there were 2 anterior+ posterior hemitransverse fractures and 6 both-column fractures, without posterior wall fracture or contralateral pelvic fracture. The CT data files of acetabular fracture were imported into the computer and 3D printing technique was used to print the fractures models after reduction by digital orthopedic technique. The acetabular wing-plate was designed and printed with titanium. All fractures were treated via the lateral-rectus approach in a horizontal position after general anesthesia. The anterior column and the quadrilateral surface fractures were fixed by 3D printing personalized acetabular wing-plate, and the posterior column fractures were reduction and fixed by antegrade lag screws under direct vision. Results: All the 8 cases underwent the operation successfully. Postoperative X-ray and CT examination showed excellent or good reduction of anterior and posterior column, without any operation complications. Only 1 case with 75 years old was found screw loosening in the pubic bone with osteoporosis after 1 month's follow-up, who didn't accept any treatment because the patient didn't feel discomfort. According to the Matta radiological evaluation, the reduction of the acetabular fracture was rated as excellent in 3 cases, good in 4 cases and fair in 1 case. All patients were followed up for 3 to 6 months and all

  11. Weak Deeply Virtual Compton Scattering

    SciTech Connect

    Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin

    2007-03-01

    We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities.

  12. Precision metrology using weak measurements.

    PubMed

    Zhang, Lijian; Datta, Animesh; Walmsley, Ian A

    2015-05-29

    Weak values and measurements have been proposed as a means to achieve dramatic enhancements in metrology based on the greatly increased range of possible measurement outcomes. Unfortunately, the very large values of measurement outcomes occur with highly suppressed probabilities. This raises three vital questions in weak-measurement-based metrology. Namely, (Q1) Does postselection enhance the measurement precision? (Q2) Does weak measurement offer better precision than strong measurement? (Q3) Is it possible to beat the standard quantum limit or to achieve the Heisenberg limit with weak measurement using only classical resources? We analyze these questions for two prototypical, and generic, measurement protocols and show that while the answers to the first two questions are negative for both protocols, the answer to the last is affirmative for measurements with phase-space interactions, and negative for configuration space interactions. Our results, particularly the ability of weak measurements to perform at par with strong measurements in some cases, are instructive for the design of weak-measurement-based protocols for quantum metrology.

  13. Endoscopic Extra-articular Surgical Removal of Heterotopic Ossification of the Rectus Femoris Tendon in a Series of Athletes

    PubMed Central

    Comba, Fernando; Piuzzi, Nicolás S.; Oñativia, José Ignacio; Zanotti, Gerardo; Buttaro, Martín; Piccaluga, Francisco

    2016-01-01

    Background: Calcific deposits in tendon, muscles, and periarticular areas are very common. Heterotopic ossification of the rectus femoris (HORF) is a rare condition, and several theories exist regarding the etiopathogenesis, which appears to be multifactorial with traumatic, genetic, and local metabolic factors involved. Although HORF typically responds to nonoperative treatment, when this approach fails, endoscopic treatment is a minimally invasive technique to address the pathology. Purpose: To report the clinical and radiological outcomes of 9 athletes with HORF who underwent endoscopic resection. Study Design: Case series; Level of evidence, 4. Methods: Nine male athletes were treated with endoscopic extra-articular resection of HORF after failure of a 6-month course of nonoperative treatment. All patients were studied with radiographs, computed tomography, and magnetic resonance imaging. Outcomes were assessed clinically using the modified Harris Hip Score (mHHS), a visual analog scale for sport activity–related pain (VAS-SRP), patient satisfaction, and ability and time to return to the preoperative sport level. Radiographic assessment was performed to determine recurrence. Results: The mean age of the patients was 32 years (range, 23-47 years). Mean follow-up was 44 months (range, 14-73 months). All patients had improved mHHS scores from a mean preoperative of 65.6 (SD, 8.2) to 93.9 (SD, 3.6). Pain decreased from a mean 8.2 preoperatively (SD, 0.9) to 0.4 (SD, 0.7) at last follow-up. There were no complications, and all patients were able to return to their previous sports at the same level except for 1 recreational athlete. There was only 1 radiological recurrence at last follow-up in an asymptomatic patient. Conclusion: To our knowledge, this is the largest case series of athletes with HORF treated with endoscopic resection. We found this extra-articular endoscopic technique to be safe and effective, showing clinical outcome improvement and 90% chance of

  14. Arthroscopic Treatment of Medial Femoral Condylar Coronal Fractures and Nonunions

    PubMed Central

    Ercin, Ersin; Bilgili, M. Gokhan; Basaran, S. Hakan; Baca, Emre; Kural, Cemal; Avkan, M. Cevdet

    2013-01-01

    Nonunion of medial femoral condylar coronal fractures are uncommon. In neglected Hoffa fractures despite nonunion, there is a risk of missing accompanying ligamentous and intra-articular injuries. Neither preoperative clinical examination nor magnetic resonance imaging showed these injuries before arthroscopy. Arthroscopy before internal fixation gives additional information and changes the surgical protocol for these fractures and nonunions. PMID:24400191

  15. Medial Patellofemoral Ligament Reconstruction in a Below-Knee Amputee.

    PubMed

    El-Tawil, Sherif; Elfons Tawafig, Marian; Miles, Jonathan

    2015-01-01

    Patellar instability is a common finding in patients with below-knee amputation and yet management options are not commonly described in the literature. We describe the first reported case of a medial patellofemoral ligament reconstruction using allograft in a patient with a below-knee amputation. Clinical outcome at two-year follow-up remains very good.

  16. Medial Patellofemoral Ligament Reconstruction in a Below-Knee Amputee

    PubMed Central

    El-Tawil, Sherif; Elfons Tawafig, Marian; Miles, Jonathan

    2015-01-01

    Patellar instability is a common finding in patients with below-knee amputation and yet management options are not commonly described in the literature. We describe the first reported case of a medial patellofemoral ligament reconstruction using allograft in a patient with a below-knee amputation. Clinical outcome at two-year follow-up remains very good. PMID:26579321

  17. Medial Temporal Lobe Memory in Childhood: Developmental Transitions

    ERIC Educational Resources Information Center

    Townsend, Elise L.; Richmond, Jenny L.; Vogel-Farley, Vanessa K.; Thomas, Kathleen

    2010-01-01

    The medial temporal lobes (MTL) support declarative memory and mature structurally and functionally during the postnatal years in humans. Although recent work has addressed the development of declarative memory in early childhood, less is known about continued development beyond this period of time. The purpose of this investigation was to explore…

  18. Medial Temporal Lobe Structures Contribute to On-Line Processing

    ERIC Educational Resources Information Center

    Warren, David

    2009-01-01

    For the last five decades, the medial temporal lobes have been generally understood to facilitate enduring representation of certain kinds of information. In particular, knowledge about the relations among items and concepts appears to rely on that region of the brain. Recent results suggest that those same structures also play a subtle role in…

  19. Theta Synchronizes the Activity of Medial Prefrontal Neurons during Learning

    ERIC Educational Resources Information Center

    Paz, Rony; Bauer, Elizabeth P.; Pare, Denis

    2008-01-01

    Memory consolidation is thought to involve the gradual transfer of transient hippocampal-dependent traces to distributed neocortical sites via the rhinal cortices. Recently, medial prefrontal (mPFC) neurons were shown to facilitate this process when their activity becomes synchronized. However, the mechanisms underlying this enhanced synchrony…

  20. Medial temporal lobe volume predicts elders' everyday memory.

    PubMed

    Bailey, Heather R; Zacks, Jeffrey M; Hambrick, David Z; Zacks, Rose T; Head, Denise; Kurby, Christopher A; Sargent, Jesse Q

    2013-07-01

    Deficits in memory for everyday activities are common complaints among healthy and demented older adults. The medial temporal lobes and dorsolateral prefrontal cortex are both affected by aging and early-stage Alzheimer's disease, and are known to influence performance on laboratory memory tasks. We investigated whether the volume of these structures predicts everyday memory. Cognitively healthy older adults and older adults with mild Alzheimer's-type dementia watched movies of everyday activities and completed memory tests on the activities. Structural MRI was used to measure brain volume. Medial temporal but not prefrontal volume strongly predicted subsequent memory. Everyday memory depends on segmenting activity into discrete events during perception, and medial temporal volume partially accounted for the relationship between performance on the memory tests and performance on an event-segmentation task. The everyday-memory measures used in this study involve retrieval of episodic and semantic information as well as working memory updating. Thus, the current findings suggest that during perception, the medial temporal lobes support the construction of event representations that determine subsequent memory.

  1. Medial Temporal Lobe Volume Predicts Elders' Everyday Memory

    PubMed Central

    Bailey, Heather R.; Zacks, Jeffrey M.; Hambrick, David Z.; Zacks, Rose T.; Head, Denise; Kurby, Christopher A.; Sargent, Jesse Q.

    2013-01-01

    Deficits in memory for everyday activities are common complaints among healthy and demented older adults. The medial temporal lobes and dorsolateral prefrontal cortex are both affected by aging and early-stage Alzheimer's disease, and are known to influence performance on laboratory memory tasks. We investigated whether the volume of these structures predicts everyday memory. Cognitively healthy older adults and older adults with mild Alzheimer's-type dementia watched movies of everyday activities and completed memory tests on the activities. Structural MRI was used to measure brain volume. Medial temporal but not prefrontal volume strongly predicted subsequent memory. Everyday memory depends on segmenting activity into discrete events during perception, and medial temporal volume partially accounted for the relationship between performance on the memory tests and performance on an event-segmentation task. The everyday-memory measures used in this study involve retrieval of episodic and semantic information as well as working memory updating. Thus, the current findings suggest that during perception, the medial temporal lobes support the construction of event representations that determine subsequent memory. PMID:23630222

  2. Medial Prefrontal Cortex Lesions Abolish Contextual Control of Competing Responses

    ERIC Educational Resources Information Center

    Haddon, J. E.; Killcross, A. S.

    2005-01-01

    There is much debate as to the extent and nature of functional specialization within the different subregions of the prefrontal cortex. The current study was undertaken to investigate the effect of damage to medial prefrontal cortex subregions in the rat. Rats were trained on two biconditional discrimination tasks, one auditory and one visual, in…

  3. Scene-Selectivity and Retinotopy in Medial Parietal Cortex

    PubMed Central

    Silson, Edward H.; Steel, Adam D.; Baker, Chris I.

    2016-01-01

    Functional imaging studies in human reliably identify a trio of scene-selective regions, one on each of the lateral [occipital place area (OPA)], ventral [parahippocampal place area (PPA)], and medial [retrosplenial complex (RSC)] cortical surfaces. Recently, we demonstrated differential retinotopic biases for the contralateral lower and upper visual fields within OPA and PPA, respectively. Here, using functional magnetic resonance imaging, we combine detailed mapping of both population receptive fields (pRF) and category-selectivity, with independently acquired resting-state functional connectivity analyses, to examine scene and retinotopic processing within medial parietal cortex. We identified a medial scene-selective region, which was contained largely within the posterior and ventral bank of the parieto-occipital sulcus (POS). While this region is typically referred to as RSC, the spatial extent of our scene-selective region typically did not extend into retrosplenial cortex, and thus we adopt the term medial place area (MPA) to refer to this visually defined scene-selective region. Intriguingly MPA co-localized with a region identified solely on the basis of retinotopic sensitivity using pRF analyses. We found that MPA demonstrates a significant contralateral visual field bias, coupled with large pRF sizes. Unlike OPA and PPA, MPA did not show a consistent bias to a single visual quadrant. MPA also co-localized with a region identified by strong differential functional connectivity with PPA and the human face-selective fusiform face area (FFA), commensurate with its functional selectivity. Functional connectivity with OPA was much weaker than with PPA, and similar to that with face-selective occipital face area (OFA), suggesting a closer link with ventral than lateral cortex. Consistent with prior research, we also observed differential functional connectivity in medial parietal cortex for anterior over posterior PPA, as well as a region on the lateral

  4. Weak Energy: Form and Function

    NASA Astrophysics Data System (ADS)

    Parks, Allen D.

    The equation of motion for a time-dependent weak value of a quantum mechanical observable contains a complex valued energy factor—the weak energy of evolution. This quantity is defined by the dynamics of the pre-selected and post-selected states which specify the observable's weak value. It is shown that this energy: (i) is manifested as dynamical and geometric phases that govern the evolution of the weak value during the measurement process; (ii) satisfies the Euler-Lagrange equations when expressed in terms of Pancharatnam (P) phase and Fubini-Study (FS) metric distance; (iii) provides for a PFS stationary action principle for quantum state evolution; (iv) time translates correlation amplitudes; (v) generalizes the temporal persistence of state normalization; and (vi) obeys a time-energy uncertainty relation. A similar complex valued quantity—the pointed weak energy of an evolving quantum state—is also defined and several of its properties in PFS coordinates are discussed. It is shown that the imaginary part of the pointed weak energy governs the state's survival probability and its real part is—to within a sign—the Mukunda-Simon geometric phase for arbitrary evolutions or the Aharonov-Anandan (AA) geometric phase for cyclic evolutions. Pointed weak energy gauge transformations and the PFS 1-form are defined and discussed and the relationship between the PFS 1-form and the AA connection 1-form is established. [Editors note: for a video of the talk given by Prof. Parks at the Aharonov-80 conference in 2012 at Chapman University, see http://quantum.chapman.edu/talk-25.

  5. A Finite Element Analysis of Medial Patellofemoral Ligament Reconstruction

    PubMed Central

    DeVries Watson, Nicole A.; Duchman, Kyle R.; Bollier, Matthew J.; Grosland, Nicole M.

    2015-01-01

    Background The medial patellofemoral ligament is the primary soft-tissue restraint to lateral patella translation. Medial patellofemoral ligament reconstruction has become a viable surgical option to provide patellar stability in patients with recurrent instability. The primary goal of this study was to determine the effect of medial patellofemoral ligament reconstruction on the lateral force-displacement behavior of the patella using finite element analyses. Methods A finite element model of the knee was created using cadaveric image data. Experimental testing was performed to validate the computational model. After validation, the model was modified to study the effect of various medial patellofemoral ligament reconstruction insertion sites, allowing comparison of patellofemoral contact force and pressure. Results For the intact anatomic model, the lateral restraining force was 80.0 N with a corresponding patellar contact area of 54.97 mm2. For the anatomic reconstructed medial patellofemoral ligament model, the lateral restraining force increased to 148.9 N with a contact area of 71.78 mm2. This compared favorably to the corresponding experimental study. The force required to laterally displace the patella increased when the femoral insertion site was moved anteriorly or distally. The lateral restraining force decreased when the femoral insertion site moved proximally and the patellar insertion site moved either proximal or distal by 5 mm. Conclusion The line of action was altered with insertion site position, which in turn changed the amount of force it took to displace the patella laterally. Considering the model constraints, an anterior femoral attachment may over constrain the patella and increase cartilage wear due to increase contact area and restraining force. Clinical Relevance A malpositioned femoral tunnel in MPFL reconstruction could increase restraining forces and PF contact pressure, thus it is suggested to use intra-operative fluoroscopy to confirm

  6. Rehabilitation and Return to Sport Following Surgical Repair of the Rectus Abdominis and Adductor Longus in a Professional Basketball Player: A Case Report.

    PubMed

    Short, Steven M; Anloague, Philip A; Strack, Donald S

    2016-08-01

    Study Design Case report. Background Acute traumatic avulsion of the rectus abdominis and adductor longus is rare. Chronic groin injuries, often falling under the athletic pubalgia spectrum, have been reported to be more common. There is limited evidence detailing the comprehensive rehabilitation and return to sport of an athlete following surgical or conservative treatment of avulsion injuries of the pubis or other sports-related groin pathologies. Case Description A 29-year-old National Basketball Association player sustained a contact injury during a professional basketball game. This case report describes a unique clinical situation specific to professional sport, in which a surgical repair of an avulsed rectus abdominis and adductor longus was combined with a multimodal impairment- and outcomes-based rehabilitation program. Outcomes The patient returned to in-season competition at 5 weeks postoperation. Objective measures were tracked throughout rehabilitation and compared to baseline assessments. Measures such as the Copenhagen Hip and Groin Outcome Score and numeric pain-rating scale revealed progress beyond the minimal important difference. Discussion This case report details the clinical reasoning and evidence-informed interventions involved in the return to elite sport. Detailed programming and objective assessment may assist in achieving desired outcomes ahead of previously established timelines. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2016;46(8):697-706. Epub 3 Jul 2016. doi:10.2519/jospt.2016.6352.

  7. Free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps for breast reconstruction: a systematic review of flap complication rates and donor-site morbidity.

    PubMed

    Sailon, Alexander M; Schachar, Jeffrey S; Levine, Jamie P

    2009-05-01

    Free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps represent increasingly popular options for breast reconstruction. Although several retrospective, small-scale studies comparing these flaps have been published, most have failed to find a significant difference in flap complication rates or donor-site morbidity. We systematically reviewed the current literature, and subsequently pooled and analyzed data from included studies. Included studies reported flap complications and/or donor site morbidities for both flap types. Eight studies met the inclusionary criteria. For flap complications, there was a statistically significant difference between deep inferior epigastric perforator and free transverse rectus abdominis myocutaneous flaps in fat necrosis rates (25.5 +/- 0.49 vs. 11.3% +/- 0.41%, P < 0.001) and total necrosis rates (4.15 +/- 0.08 vs. 1.59% +/- 0.08%, P = 0.044). Partial necrosis rates were not statistically significant (3.54 +/- 0.07 vs. 1.60% +/- 0.07%, P = 0.057). For donor-site morbidity, there was no statistically significant difference in abdominal bulge (8.07 +/- 0.23 vs. 11.25% +/- 0.29%, P = 0.28). Multicenter, prospective studies are needed to further investigate differences between these flap options.

  8. Warping the Weak Gravity Conjecture

    NASA Astrophysics Data System (ADS)

    Kooner, Karta; Parameswaran, Susha; Zavala, Ivonne

    2016-08-01

    The Weak Gravity Conjecture, if valid, rules out simple models of Natural Inflation by restricting their axion decay constant to be sub-Planckian. We revisit stringy attempts to realise Natural Inflation, with a single open string axionic inflaton from a probe D-brane in a warped throat. We show that warped geometries can allow the requisite super-Planckian axion decay constant to be achieved, within the supergravity approximation and consistently with the Weak Gravity Conjecture. Preliminary estimates of the brane backreaction suggest that the probe approximation may be under control. However, there is a tension between large axion decay constant and high string scale, where the requisite high string scale is difficult to achieve in all attempts to realise large field inflation using perturbative string theory. We comment on the Generalized Weak Gravity Conjecture in the light of our results.

  9. Weak values in continuous weak measurements of qubits

    NASA Astrophysics Data System (ADS)

    Qin, Lupei; Liang, Pengfei; Li, Xin-Qi

    2015-07-01

    For continuous weak measurements of qubits, we obtain exact expressions for weak values (WVs) from the postselection restricted average of measurement outputs, by using both the quantum-trajectory equation (QTE) and the quantum Bayesian approach. The former is applicable to short-time weak measurement, while the latter can relax the measurement strength to finite. We find that even in the "very" weak limit the result can be essentially different from the one originally proposed by Aharonov, Albert, and Vaidman (AAV), in the sense that our result incorporates nonperturbative correction which could be important when the AAV WV is large. Within the Bayesian framework, we obtain also elegant expressions for finite measurement strength and find that the amplifier's noise in quantum measurement has no effect on the WVs. In particular, we obtain very useful results for homodyne measurement in a circuit-QED system, which allows for measuring the real and imaginary parts of the AAV WV by simply tuning the phase of the local oscillator. This advantage can be exploited as an efficient state-tomography technique.

  10. Weak localization and weak antilocalization in doped germanium epilayers

    NASA Astrophysics Data System (ADS)

    Newton, P. J.; Mansell, R.; Holmes, S. N.; Myronov, M.; Barnes, C. H. W.

    2017-02-01

    The magnetoresistance of 50 nm thick epilayers of doped germanium is measured at a range of temperatures down to 1.6 K. Both n- and p-type devices show quantum corrections to the conductivity in an applied magnetic field, with n-type devices displaying weak localization and p-type devices showing weak antilocalization. From fits to these data using the Hikami-Larkin-Nagaoka model, the phase coherence length of each device is extracted, as well as the spin diffusion length of the p-type device. We obtain phase coherence lengths as large as 325 nm in the highly doped n-type device, presenting possible applications in quantum technologies. The decay of the phase coherence length with temperature is found to obey the same power law of lϕ ∝ Tc, where c = -0.68 ± 0.03, for each device, in spite of the clear differences in the nature of the conduction. In the p-type device, the measured spin diffusion length does not change over the range of temperatures for which weak antilocalization can be observed. The presence of a spin-orbit interaction manifested as weak antilocalization in the p-type epilayer suggests that these structures could be developed for use in spintronic devices such as the spin-FET, where significant spin lifetimes would be important for efficient device operation.

  11. Cosmology and the weak interaction

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1989-01-01

    The weak interaction plays a critical role in modern Big Bang cosmology. Two of its most publicized comological connections are emphasized: big bang nucleosynthesis and dark matter. The first of these is connected to the cosmological prediction of neutrine flavors, N(sub nu) is approximately 3 which in now being confirmed. The second is interrelated to the whole problem of galacty and structure formation in the universe. The role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure is demonstrated.

  12. Cosmology and the weak interaction

    SciTech Connect

    Schramm, D.N. ):)

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.

  13. Medial Auditory Thalamus Inactivation Prevents Acquisition and Retention of Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Poremba, Amy; Freeman, John H.

    2008-01-01

    The auditory conditioned stimulus (CS) pathway that is necessary for delay eyeblink conditioning was investigated using reversible inactivation of the medial auditory thalamic nuclei (MATN) consisting of the medial division of the medial geniculate (MGm), suprageniculate (SG), and posterior intralaminar nucleus (PIN). Rats were given saline or…

  14. Dynamic Changes in Acetylcholine Output in the Medial Striatum during Place Reversal Learning

    ERIC Educational Resources Information Center

    Ragozzino, Michael E.; Choi, Daniel

    2004-01-01

    The present studies explored the role of the medial striatum in learning when task contingencies change. Experiment 1 examined whether the medial striatum is involved in place reversal learning. Testing occurred in a modified cross-maze across two consecutive sessions. Injections of the local anesthetic, bupivacaine, into the medial striatum, did…

  15. Expression of mu opioid receptor in dorsal diencephalic conduction system: new insights for the medial habenula

    PubMed Central

    Gardon, O.; Faget, L.; Chu Sin Chung, P.; Matifas, A.; Massotte, D; Kieffer, B.L.

    2014-01-01

    The habenular complex, encompassing medial (MHb) and lateral (LHb) divisions, is a highly conserved epithalamic structure involved in the dorsal diencephalic conduction system (DDC). These brain nuclei regulate information flow between the limbic forebrain and the mid- and hindbrain, integrating cognitive with emotional and sensory processes. The MHb is also one of the strongest expression sites for mu opioid receptors (MORs), which mediate analgesic and rewarding properties of opiates. At present however, anatomical distribution and function of these receptors have been poorly studied in MHb pathways. Here we took advantage of a newly generated MOR-mcherry knock-in mouse line to characterize MOR expression sites in the DDC. MOR-mcherry fluorescent signal is weak in the lateral habenula, but strong expression is visible in the medial habenula, fasciculus retroflexus and interpeduncular nucleus (IPN), indicating that MOR is mainly present in the MHb-IPN pathway. MOR-mcherry cell bodies are detected both in basolateral and apical parts of MHb, where the receptor co-localizes with cholinergic and Substance P (SP) neurons, respectively, representing two main MHb neuronal populations. MOR-mcherry is expressed in most MHb-SP neurons, and is present in only a subpopulation of MHb-cholinergic neurons. Intense diffuse fluorescence detected in lateral and rostral parts of the IPN further suggests that MOR-mcherry is transported to terminals of these SP and cholinergic neurons. Finally, MOR-mcherry is present in septal regions projecting to the MHb, and in neurons of the central and intermediate IPN. Together, this study describes MOR expression in several compartments of the MHb-IPN circuitry. The remarkably high MOR density in the MHb-IPN pathway suggests that these receptors are in a unique position to mediate analgesic, autonomic and reward responses. PMID:25086313

  16. Anisotropic weak localization of light.

    PubMed

    Sapienza, Riccardo; Mujumdar, Sushil; Cheung, Cecil; Yodh, A G; Wiersma, Diederik

    2004-01-23

    We have observed angular anisotropy in weak localization of light from highly scattering, orientationally ordered, nematic liquid crystals. This demonstration of angular anisotropy in a multiple-scattering interference phenomenon was facilitated by a light scattering instrument with extraordinary angular resolution. The measured anisotropies were consistent with a simple model of coherent backscattering generalized for propagation-direction dependent mean free paths.

  17. N-{Delta} weak transition

    SciTech Connect

    Graczyk, Krzysztof M.

    2011-11-23

    A short review of the Rein-Sehgal and isobar models is presented. The attention is focused on the nucleon-{Delta}(1232) weak transition form-factors. The results of the recent re-analyses of the ANL and BNL bubble chamber neutrino-deuteron scattering data are discussed.

  18. Theory of weak hypernuclear decay

    SciTech Connect

    Dubach, J.F.; Feldman, G.B.; Holstein, B.R. |; de la Torre, L.

    1996-07-01

    The weak nomesonic decay of {Lambda}-hypernuclei is studied in the context of a one-meson-exchange model. Predictions are made for the decay rate, the {ital p}/{ital n} stimulation ratio and the asymmetry in polarized hypernuclear decay. Copyright {copyright} 1996 Academic Press, Inc.

  19. Weak localization of seismic waves.

    PubMed

    Larose, E; Margerin, L; Van Tiggelen, B A; Campillo, M

    2004-07-23

    We report the observation of weak localization of seismic waves in a natural environment. It emerges as a doubling of the seismic energy around the source within a spot of the width of a wavelength, which is several tens of meters in our case. The characteristic time for its onset is the scattering mean-free time that quantifies the internal heterogeneity.

  20. Cosmology with weak lensing surveys.

    PubMed

    Munshi, Dipak; Valageas, Patrick

    2005-12-15

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening mass. Since the lensing effects arise from deflections of the light rays due to fluctuations of the gravitational potential, they can be directly related to the underlying density field of the large-scale structures. Weak gravitational surveys are complementary to both galaxy surveys and cosmic microwave background observations as they probe unbiased nonlinear matter power spectra at medium redshift. Ongoing CMBR experiments such as WMAP and a future Planck satellite mission will measure the standard cosmological parameters with unprecedented accuracy. The focus of attention will then shift to understanding the nature of dark matter and vacuum energy: several recent studies suggest that lensing is the best method for constraining the dark energy equation of state. During the next 5 year period, ongoing and future weak lensing surveys such as the Joint Dark Energy Mission (JDEM; e.g. SNAP) or the Large-aperture Synoptic Survey Telescope will play a major role in advancing our understanding of the universe in this direction. In this review article, we describe various aspects of probing the matter power spectrum and the bi-spectrum and other related statistics with weak lensing surveys. This can be used to probe the background dynamics of the universe as well as the nature of dark matter and dark energy.

  1. Medial prefrontal D1 dopamine neurons control food intake

    PubMed Central

    Land, Benjamin B; Narayanan, Nandakumar S; Liu, Rong-Jian; Gianessi, Carol A; Brayton, Catherine E; Grimaldi, David; Sarhan, Maysa; Guarnieri, Douglas J; Deisseroth, Karl; Aghajanian, George K; Dileone, Ralph J

    2014-01-01

    Although the prefrontal cortex influences motivated behavior, its role in food intake remains unclear. Here, we demonstrate a role for D1-type dopamine receptor-expressing neurons in the medial prefrontal cortex (mPFC) in the regulation of feeding. Food intake increases activity in D1 neurons of the mPFC in mice, and optogenetic photostimulation of D1 neurons increases feeding. Conversely, inhibition of D1 neurons decreases intake. Stimulation-based mapping of prefrontal D1 neuron projections implicates the medial basolateral amygdala (mBLA) as a downstream target of these afferents. mBLA neurons activated by prefrontal D1 stimulation are CaMKII positive and closely juxtaposed to prefrontal D1 axon terminals. Finally, photostimulating these axons in the mBLA is sufficient to increase feeding, recapitulating the effects of mPFC D1 stimulation. These data describe a new circuit for top-down control of food intake. PMID:24441680

  2. Downregulation of the posterior medial frontal cortex prevents social conformity.

    PubMed

    Klucharev, Vasily; Munneke, Moniek A M; Smidts, Ale; Fernández, Guillén

    2011-08-17

    We often change our behavior to conform to real or imagined group pressure. Social influence on our behavior has been extensively studied in social psychology, but its neural mechanisms have remained largely unknown. Here we demonstrate that the transient downregulation of the posterior medial frontal cortex by theta-burst transcranial magnetic stimulation reduces conformity, as indicated by reduced conformal adjustments in line with group opinion. Both the extent and probability of conformal behavioral adjustments decreased significantly relative to a sham and a control stimulation over another brain area. The posterior part of the medial frontal cortex has previously been implicated in behavioral and attitudinal adjustments. Here, we provide the first interventional evidence of its critical role in social influence on human behavior.

  3. Cochlear shape description and analyzing via medial models

    NASA Astrophysics Data System (ADS)

    Gaa, Johannes; Kahrs, Lüder A.; Müller, Samuel; Majdani, Omid; Ortmaier, Tobias

    2015-03-01

    Planning and analyzing of surgical interventions are often based on computer models derived from computed tomography images of the patient. In the field of cochlear implant insertion the modeling of several structures of the inner ear is needed. One structure is the overall helical shape of the cochlea itself. In this paper we analyze the cochlea by applying statistical shape models with medial representation. The cochlea is considered as tubular structure. A model representing the skeleton of training data and an atomic composition of the structure is built. We reduce the representation to a linear chain of atoms. As result a compact discrete model is possible. It is demonstrated how to place the atoms and build up their correspondence through a population of training data. The outcome of the applied representation is discussed in terms of impact on automated segmentation algorithms and known advantages of medial models are revisited.

  4. Taiwanese life scientists less "medialized" than their Western colleagues.

    PubMed

    Lo, Yin-Yueh; Peters, Hans Peter

    2015-01-01

    The article presents results from surveys of life scientists in Taiwan (n=270) and in Germany (n=326). Fewer Taiwanese than German researchers have frequent contact with the media and they rate their experiences with journalists less positively. Furthermore, they are less prepared to adapt to journalistic expectations and to a greater extent than German researchers they expect journalists to consider scientific criteria in their reporting. These findings are interpreted in Weingart's "medialization of science" framework as indicators of lower medialization of science in Taiwan than in Germany. However, Taiwanese scientists are more willing than German scientists to accept journalistic simplification at the expense of accuracy. This is explained as an adaptation to the media system and to the perceived scientific literacy of the media audience. We hypothesize that cultural differences regarding the relative priority of relational vs. rational communication goals may also contribute to more tolerance of journalistic simplification in Taiwan.

  5. Medial vestibular connections with the hypocretin (orexin) system

    NASA Technical Reports Server (NTRS)

    Horowitz, Seth S.; Blanchard, Jane; Morin, Lawrence P.

    2005-01-01

    The mammalian medial vestibular nucleus (MVe) receives input from all vestibular endorgans and provides extensive projections to the central nervous system. Recent studies have demonstrated projections from the MVe to the circadian rhythm system. In addition, there are known projections from the MVe to regions considered to be involved in sleep and arousal. In this study, afferent and efferent subcortical connectivity of the medial vestibular nucleus of the golden hamster (Mesocricetus auratus) was evaluated using cholera toxin subunit-B (retrograde), Phaseolus vulgaris leucoagglutinin (anterograde), and pseudorabies virus (transneuronal retrograde) tract-tracing techniques. The results demonstrate MVe connections with regions mediating visuomotor and postural control, as previously observed in other mammals. The data also identify extensive projections from the MVe to regions mediating arousal and sleep-related functions, most of which receive immunohistochemically identified projections from the lateral hypothalamic hypocretin (orexin) neurons. These include the locus coeruleus, dorsal and pedunculopontine tegmental nuclei, dorsal raphe, and lateral preoptic area. The MVe itself receives a projection from hypocretin cells. CTB tracing demonstrated reciprocal connections between the MVe and most brain areas receiving MVe efferents. Virus tracing confirmed and extended the MVe afferent connections identified with CTB and additionally demonstrated transneuronal connectivity with the suprachiasmatic nucleus and the medial habenular nucleus. These anatomical data indicate that the vestibular system has access to a broad array of neural functions not typically associated with visuomotor, balance, or equilibrium, and that the MVe is likely to receive information from many of the same regions to which it projects.

  6. Bottom-up Visual Integration in the Medial Parietal Lobe.

    PubMed

    Pflugshaupt, Tobias; Nösberger, Myriam; Gutbrod, Klemens; Weber, Konrad P; Linnebank, Michael; Brugger, Peter

    2016-03-01

    Largely based on findings from functional neuroimaging studies, the medial parietal lobe is known to contribute to internally directed cognitive processes such as visual imagery or episodic memory. Here, we present 2 patients with behavioral impairments that extend this view. Both had chronic unilateral lesions of nearly the entire medial parietal lobe, but in opposite hemispheres. Routine neuropsychological examination conducted >4 years after the onset of brain damage showed little deficits of minor severity. In contrast, both patients reported persistent unusual visual impairment. A comprehensive series of tachistoscopic experiments with lateralized stimulus presentation and comparison with healthy participants revealed partial visual hemiagnosia for stimuli presented to their contralesional hemifield, applying inferential single-case statistics to evaluate deficits and dissociations. Double dissociations were found in 4 experiments during which participants had to integrate more than one visual element, either through comparison or formation of a global gestalt. Against the background of recent neuroimaging findings, we conclude that of all medial parietal structures, the precuneus is the most likely candidate for a crucial involvement in such bottom-up visual integration.

  7. Dopamine in the medial amygdala network mediates human bonding

    PubMed Central

    Touroutoglou, Alexandra; Rudy, Tali; Salcedo, Stephanie; Feldman, Ruth; Hooker, Jacob M.; Dickerson, Bradford C.; Catana, Ciprian; Barrett, Lisa Feldman

    2017-01-01

    Research in humans and nonhuman animals indicates that social affiliation, and particularly maternal bonding, depends on reward circuitry. Although numerous mechanistic studies in rodents demonstrated that maternal bonding depends on striatal dopamine transmission, the neurochemistry supporting maternal behavior in humans has not been described so far. In this study, we tested the role of central dopamine in human bonding. We applied a combined functional MRI-PET scanner to simultaneously probe mothers’ dopamine responses to their infants and the connectivity between the nucleus accumbens (NAcc), the amygdala, and the medial prefrontal cortex (mPFC), which form an intrinsic network (referred to as the “medial amygdala network”) that supports social functioning. We also measured the mothers’ behavioral synchrony with their infants and plasma oxytocin. The results of this study suggest that synchronous maternal behavior is associated with increased dopamine responses to the mother’s infant and stronger intrinsic connectivity within the medial amygdala network. Moreover, stronger network connectivity is associated with increased dopamine responses within the network and decreased plasma oxytocin. Together, these data indicate that dopamine is involved in human bonding. Compared with other mammals, humans have an unusually complex social life. The complexity of human bonding cannot be fully captured in nonhuman animal models, particularly in pathological bonding, such as that in autistic spectrum disorder or postpartum depression. Thus, investigations of the neurochemistry of social bonding in humans, for which this study provides initial evidence, are warranted. PMID:28193868

  8. A combinatorial optogenetic approach to medial habenula function

    NASA Astrophysics Data System (ADS)

    Turner, Eric E.; Hsu, Yun-Wei; Wang, Si; Morton, Glenn; Zeng, Hongkui

    2013-03-01

    The habenula is a brain region found in all vertebrate species. It consists of medial and lateral subnuclei which make complex descending connections to the brainstem. Although the medial habenula (MHb) and its projection, the fasciculus retroflexus (FR), have been recognized for decades, their function remains obscure. The small size of the MHb in rodents, and the cellular and molecular complexity of this region, have made it difficult to study the function of this region with high specificity. Here we describe a Cre-mediated genetic system for expressing the microbial opsin channelrhodopsin (ChR2) specifically in the dorsal (dMHb) and ventral (vMHb) medial habenula. Genetically targeted expression of ChR2 allows MHb neurons to be selectively activated with light in acute brain slices with electrophysiological readouts, and in vivo by means of custom-built fiber optic cannulas. These tools will allow highly specific studies of MHb circuitry and the role of the MHb in behaviors related to addiction and mood regulation.

  9. Medial Gastrocnemius Myoelectric Control of a Robotic Ankle Exoskeleton

    PubMed Central

    Kinnaird, Catherine R.; Ferris, Daniel P.

    2010-01-01

    A previous study from our laboratory showed that when soleus electromyography was used to control the amount of plantar flexion assistance from a robotic ankle exoskeleton, subjects significantly reduced their soleus activity to quickly return to normal gait kinematics. We speculated that subjects were primarily responding to the local mechanical assistance of the exoskeleton rather than directly attempting to reduce exoskeleton mechanical power via decreases in soleus activity. To test this observation we studied ten healthy subjects walking on a treadmill at 1.25 m/s while wearing a robotic exoskeleton proportionally controlled by medial gastrocnemius activation. We hypothesized that subjects would primarily decrease soleus activity due to its synergistic mechanics with the exoskeleton. Subjects decreased medial gastrocnemius recruitment by 12% (p<0.05) but decreased soleus recruitment by 27% (p<0.05). In agreement with our hypothesis, the primary reduction in muscle activity was not for the control muscle (medial gastrocnemius) but for the anatomical synergist to the exoskeleton (soleus). These findings indicate that anatomical morphology needs to be considered carefully when designing software and hardware for robotic exoskeletons. PMID:19211321

  10. Radiofrequency Neurotomy of Cervical Medial Branches for Chronic Cervicobrachialgia

    PubMed Central

    Shin, Woo-Ram; Shin, Dong-Gyu; Shin, Dong-Ah

    2006-01-01

    Chronic neck and arm pain or cervicobrachialgia commonly occurs with the degeneration of cervical spine. Authors investigated the usefulness of radiofrequency (RF) neurotomies of cervical medial branches in patients with cervicobrachialgia and analyzed the factors which can influence the treatment outcome. Demographic data, types of pain distribution, responses of double controlled blocks, electrical stimulation parameters, numbers and levels of neurotomies, and surgical outcomes were evaluated after mean follow-up of 12 months. Pain distribution pattern was not significantly correlated with the results of diagnostic blocks. Average stimulation intensity was 0.45 V, ranging from 0.3 to 0.69, to elicit pain response in cervical medial branches. The most common involvement of nerve branches was C4 (89%), followed by C5 (82%), C6 (75%), and C7 (43%). Among total of 28 patients, nineteen (68%) reported successful outcome according to outcome criteria after 6 months of follow-up (p=0.001), and eight (42%) of 19 patients reported complete relief (100%) of pain. Four patients showed recurrence of pain between 6 and 12 months. It was therefore concluded that cervical medial branch neurotomy is considered useful therapeutic modality for the management of cervicobrachialgia in selected patients, particularly in degenerative zygapophyseal disorders. PMID:16479077

  11. Radiofrequency neurotomy of cervical medial branches for chronic cervicobrachialgia.

    PubMed

    Shin, Woo-Ram; Kim, Hyoung-Ihl; Shin, Dong-Gyu; Shin, Dong-Ah

    2006-02-01

    Chronic neck and arm pain or cervicobrachialgia commonly occurs with the degeneration of cervical spine. Authors investigated the usefulness of radiofrequency (RF) neurotomies of cervical medial branches in patients with cervicobrachialgia and analyzed the factors which can influence the treatment outcome. Demographic data, types of pain distribution, responses of double controlled blocks, electrical stimulation parameters, numbers and levels of neurotomies, and surgical outcomes were evaluated after mean follow-up of 12 months. Pain distribution pattern was not significantly correlated with the results of diagnostic blocks. Average stimulation intensity was 0.45 V, ranging from 0.3 to 0.69, to elicit pain response in cervical medial branches. The most common involvement of nerve branches was C4 (89%), followed by C5 (82%), C6 (75%), and C7 (43%). Among total of 28 patients, nineteen (68%) reported successful outcome according to outcome criteria after 6 months of followup (p=0.001), and eight (42%) of 19 patients reported complete relief (100%) of pain. Four patients showed recurrence of pain between 6 and 12 months. It was therefore concluded that cervical medial branch neurotomy is considered useful therapeutic modality for the management of cervicobrachialgia in selected patients, particularly in degenerative zygapophyseal disorders.

  12. Arthroscopic Removal of Shotgun Pellet From Within the Medial Meniscus

    PubMed Central

    Lacy, Kyle; Cooke, Chris; Cooke, Pat; Tonnos, Frederick

    2016-01-01

    Arthroscopic techniques are effective for the removal of intra-articular bullet and metal fragments after gunshot wounds to the shoulder, hip, knee, and sacroiliac joints. Surgical removal of bullets retained within the synovial joints is indicated; lead is dissolved by synovial fluid over time, leading to proliferative synovitis, lead arthropathy, elevated serum lead levels, and lead toxicity. We present an arthroscopic technique for removal of a shotgun pellet retained within the medial meniscus. In this technique, diagnostic knee arthroscopy is initially performed, which allows for localization of the pellet within the medial meniscus. An up-biter is used to resect the inner rim of meniscus surrounding the pellet, and the pellet is removed with a grasper. This arthroscopic approach is advantageous because it allows for efficient visualization of the pellet within the meniscus, thorough visualization of all compartments of the knee, a reduction in blood loss, and a decrease in surgical morbidity to the surrounding cartilaginous, neurovascular, and soft-tissue structures. This technique may therefore be one option to address bullet fragments or shotgun pellets that are retained within the medial meniscus. PMID:27073774

  13. Arthroscopic trans-portal deep medial collateral ligament pie-crusting release.

    PubMed

    Atoun, Ehud; Debbi, Ronen; Lubovsky, Omri; Weiler, Andreas; Debbi, Eytan; Rath, Ehud

    2013-02-01

    Arthroscopic treatments of meniscal injuries of the knee are among the most common orthopaedic procedures performed. Adequate visualization of the posterior horn of the medial meniscus might be challenging, especially in patients with tight medial compartments. In these cases instrument manipulation in an attempt to reach the posterior horn of the meniscus can cause an iatrogenic chondral injury because of the narrow medial joint space. A transcutaneous medial collateral ligament (MCL) pie-crusting release facilitates expansion of the medial joint space in a case of a tight medial compartment. Nevertheless, it might cause injury to the superficial MCL, infection, and pain and injury to the saphenous nerve because of multiple needle punctures of the skin. We describe an inside-out, arthroscopic deep MCL pie-crusting release, which allows access to the medial meniscus through the anterior approach to provide good visualization of the footprint and sufficient working space.

  14. Weak values and weak coupling maximizing the output of weak measurements

    SciTech Connect

    Di Lorenzo, Antonio

    2014-06-15

    In a weak measurement, the average output 〈o〉 of a probe that measures an observable A{sup -hat} of a quantum system undergoing both a preparation in a state ρ{sub i} and a postselection in a state E{sub f} is, to a good approximation, a function of the weak value A{sub w}=Tr[E{sub f}A{sup -hat} ρ{sub i}]/Tr[E{sub f}ρ{sub i}], a complex number. For a fixed coupling λ, when the overlap Tr[E{sub f}ρ{sub i}] is very small, A{sub w} diverges, but 〈o〉 stays finite, often tending to zero for symmetry reasons. This paper answers the questions: what is the weak value that maximizes the output for a fixed coupling? What is the coupling that maximizes the output for a fixed weak value? We derive equations for the optimal values of A{sub w} and λ, and provide the solutions. The results are independent of the dimensionality of the system, and they apply to a probe having a Hilbert space of arbitrary dimension. Using the Schrödinger–Robertson uncertainty relation, we demonstrate that, in an important case, the amplification 〈o〉 cannot exceed the initial uncertainty σ{sub o} in the observable o{sup -hat}, we provide an upper limit for the more general case, and a strategy to obtain 〈o〉≫σ{sub o}. - Highlights: •We have provided a general framework to find the extremal values of a weak measurement. •We have derived the location of the extremal values in terms of preparation and postselection. •We have devised a maximization strategy going beyond the limit of the Schrödinger–Robertson relation.

  15. Tomography and weak lensing statistics

    SciTech Connect

    Munshi, Dipak; Coles, Peter; Kilbinger, Martin E-mail: peter.coles@astro.cf.ac.uk

    2014-04-01

    We provide generic predictions for the lower order cumulants of weak lensing maps, and their correlators for tomographic bins as well as in three dimensions (3D). Using small-angle approximation, we derive the corresponding one- and two-point probability distribution function for the tomographic maps from different bins and for 3D convergence maps. The modelling of weak lensing statistics is obtained by adopting a detailed prescription for the underlying density contrast that involves hierarchal ansatz and lognormal distribution. We study the dependence of our results on cosmological parameters and source distributions corresponding to the realistic surveys such as LSST and DES. We briefly outline how photometric redshift information can be incorporated in our results. We also show how topological properties of convergence maps can be quantified using our results.

  16. The effect of different depths of medial heel skive on plantar pressures

    PubMed Central

    2012-01-01

    Background Foot orthoses are often used to treat lower limb injuries associated with excessive pronation. There are many orthotic modifications available for this purpose, with one being the medial heel skive. However, empirical evidence for the mechanical effects of the medial heel skive modification is limited. This study aimed to evaluate the effect that different depths of medial heel skive have on plantar pressures. Methods Thirty healthy adults (mean age 24 years, range 18–46) with a flat-arched or pronated foot posture and no current foot pain or deformity participated in this study. Using the in-shoe pedar-X® system, plantar pressure data were collected for the rearfoot, midfoot and forefoot while participants walked along an 8 metre walkway wearing a standardised shoe. Experimental conditions included a customised foot orthosis with the following 4 orthotic modifications: (i) no medial heel skive, (ii) a 2 mm medial heel skive, (iii) a 4 mm medial heel skive and (iv) a 6 mm medial heel skive. Results Compared to the foot orthosis with no medial heel skive, statistically significant increases in peak pressure were observed at the medial rearfoot – there was a 15% increase (p = 0.001) with the 4 mm skive and a 29% increase (p < 0.001) with the 6 mm skive. No significant change was observed with the 2 mm medial heel skive. With respect to the midfoot and forefoot, there were no significant differences between the orthoses. Conclusions This study found that a medial heel skive of 4 mm or 6 mm increases peak pressure under the medial rearfoot in asymptomatic adults with a flat-arched or pronated foot posture. Plantar pressures at the midfoot and forefoot were not altered by a medial heel skive of 2, 4 or 6 mm. These findings provide some evidence for the effects of the medial heel skive orthotic modification. PMID:22889267

  17. Multimodal intervention in older adults improves resting-state functional connectivity between the medial prefrontal cortex and medial temporal lobe.

    PubMed

    Li, Rui; Zhu, Xinyi; Yin, Shufei; Niu, Yanan; Zheng, Zhiwei; Huang, Xin; Wang, Baoxi; Li, Juan

    2014-01-01

    The prefrontal cortex and medial temporal lobe are particularly vulnerable to the effects of aging. The disconnection between them is suggested to be an important cause of cognitive decline in normal aging. Here, using multimodal intervention training, we investigated the functional plasticity in resting-state connectivity of these two regions in older adults. The multimodal intervention, comprised of cognitive training, Tai Chi exercise, and group counseling, was conducted to explore the regional connectivity changes in the default-mode network, as well as changes in prefrontal-based voxel-wise connectivity in the whole brain. Results showed that the intervention selectively affected resting-state functional connectivity between the medial prefrontal cortex and medial temporal lobe. Moreover, the strength of resting-state functional connectivity between these regions correlated with individual cognitive performance. Our results suggest that multimodal intervention could postpone the effects of aging and improve the function of the regions that are most heavily influenced by aging, as well as play an important role in preserving the brain and cognition during old age.

  18. Comparison of fat necrosis between zone II and zone III in pedicled transverse rectus abdominis musculocutaneous flaps: a prospective study of 400 consecutive cases.

    PubMed

    Kim, Eun Key; Lee, Taik Jong; Eom, Jin Sup

    2007-09-01

    Fat necrosis in transverse rectus abdominis musculocutaneous (TRAM) flap is considered to be mainly affected by blood supply. This prospective study compares the incidence of fat necrosis between zones II and III in 400 consecutive patients who had undergone unipedicled TRAM flap breast reconstruction. Fifty-eight patients (14.5%) suffered from fat necrosis, and 7 had 2 separate nodules. Fifty-four occurred in zone II, 10 in zone III, and 1 in zone I. The incidence of fat necrosis in zone II was significantly higher than in zone III (P < 0.001). The weight of the mastectomy specimen and the relative amount of zone II tissue included in the flap had positive correlation with the incidence of fat necrosis. This result implies relatively poor perfusion of zone II compared with zone III.

  19. Spontaneous Rectus Sheath Hematoma in Pregnancy Complicated by the Development of Transfusion Related Acute Lung Injury: A Case Report and Review of the Literature

    PubMed Central

    Gibbs, Jennifer; Bridges, Firas; Trivedi, Kiran; Vullo, John

    2016-01-01

    Background Rectus sheath hematoma (RSH) represents a rare, but serious cause of abdominal pain. Case Here we discuss the case of a healthy multigravida female who presented at 28 weeks gestation with spontaneous RSH. Conservative management with multiple blood transfusions led to the development of transfusion related acute lung injury (TRALI) and intensive care unit admission. She was managed with noninvasive ventilatory support, gradually improved, and was weaned of ventilation. After hospital discharge, she progressed to full term and delivered a viable male infant vaginally at 37 weeks gestation. Conclusion Review of the literature demonstrates 13 cases of RSH in pregnancy, including our own. No other cases were complicated by transfusion related morbidity. RSH and TRALI are rare, but life threatening entities that can complicate pregnancy. PMID:27651980

  20. A Novel Medial Soft Tissue Release Method for Varus Deformity during Total Knee Arthroplasty: Femoral Origin Release of the Medial Collateral Ligament

    PubMed Central

    Lee, Seung-Yup; Yang, Jae-Hyuk; Lee, Yong-In

    2016-01-01

    Introduction Numerous methods of medial soft tissue release for severe varus deformity during total knee arthroplasty (TKA) have been reported. These include tibial stripping of the superficial medial collateral ligament (MCL), pie-crusting technique, and medial epicondylar osteotomy. However, there are inherent disadvantages in these techniques. Authors hereby present a novel quantitative method: femoral origin release of the medial collateral ligament (FORM). Surgical Technique For medial tightness remaining even after the release of the deep MCL and semimembranosus, the FORM is initiated with identification of the femoral insertion area of the MCL with the knee in flexion. Starting from the most posterior part of the femoral insertion, one third of the MCL femoral insertion is released from its attachment. If necessary, further sequential medial release is performed. Materials and Methods Seventeen knees that underwent the FORM were evaluated for radiological and clinical outcomes. Results Regardless of the extent of the FORM, no knees showed residual valgus instability at 24 weeks after surgery. Conclusions As the FORM is performed in a stepwise manner, fine adjustment during medial release might be beneficial to prevent inadvertent over-release of the medial structures of the knee. PMID:27274473

  1. Arthroscopic decompressive medial release of the varus arthritic knee: Expanding the functional envelope.

    PubMed

    Leon, H O; Blanco, C E; Guthrie, T B

    2001-05-01

    We present the rationale and technique for treating medial knee osteoarthritis by dynamically unloading the medial compartment of the knee. Recent advances in kinematic studies indicate a dynamic linkage between differing degrees of freedom in the knee joint. Both the adduction moment and the foot progression angle are important determinants of medial compartment loading. The medially osteoarthritic knee has progressive compromise of free motion in more than 1 plane. Arthroscopic decompressive medial release unloads the medial compartment by release of the medial capsule and medial collateral ligament in the presence of intact cruciate ligaments, which may allow a decreased adduction moment and decrease of the external rotation restraint in extension found in more severely osteoarthritic knees. A case series of 38 patients with medial gonarthrosis was treated by this technique at the Hermanos Ameijeiras Hospital in Havana, Cuba. All patients had good results without postoperative valgus instability or significant complications. We feel that this technique warrants further clinical and biomechanical study for its use in isolation or in combination with high tibial osteotomy or minimally invasive selective osteotomy for the treatment of medial gonarthrosis of the knee. A minimally invasive, selective approach to biomechanical factors in osteoarthritis may be combined with other modulating techniques in efforts to forestall or prevent the need for total joint replacement.

  2. Detecting weakly interacting massive particles.

    NASA Astrophysics Data System (ADS)

    Drukier, A. K.; Gelmini, G. B.

    The growing synergy between astrophysics, particle physics, and low background experiments strengthens the possibility of detecting astrophysical non-baryonic matter. The idea of direct detection is that an incident, massive weakly interacting particle could collide with a nucleus and transfer an energy that could be measured. The present low levels of background achieved by the PNL/USC Ge detector represent a new technology which yields interesting bounds on Galactic cold dark matter and on light bosons emitted from the Sun. Further improvements require the development of cryogenic detectors. The authors analyse the practicality of such detectors, their optimalization and background suppression using the "annual modulation effect".

  3. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    PubMed

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  4. Modulating Phonation Through Alteration of Vocal Fold Medial Surface Contour

    PubMed Central

    Mau, Ted; Muhlestein, Joseph; Callahan, Sean; Chan, Roger W.

    2012-01-01

    Objectives 1. To test whether alteration of the vocal fold medial surface contour can improve phonation. 2. To demonstrate that implant material properties affect vibration even when implant is deep to the vocal fold lamina propria. Study Design Induced phonation of excised human larynges. Methods Thirteen larynges were harvested within 24 hours post-mortem. Phonation threshold pressure (PTP) and flow (PTF) were measured before and after vocal fold injections using either calcium hydroxylapatite (CaHA) or hyaluronic acid (HA). Small-volume injections (median 0.0625 mL) were targeted to the infero-medial aspect of the thyroarytenoid (TA) muscle. Implant locations were assessed histologically. Results The effect of implantation on PTP was material-dependent. CaHA tended to increase PTP, whereas HA tended to decrease PTP (Wilcoxon test P = 0.00013 for onset). In contrast, the effect of implantation on PTF was similar, with both materials tending to decrease PTF (P = 0.16 for onset). Histology confirmed implant presence in the inferior half of the vocal fold vertical thickness. Conclusions Taken together, these data suggested the implants may have altered the vocal fold medial surface contour, potentially resulting in a less convergent or more rectangular glottal geometry as a means to improve phonation. An implant with a closer viscoelastic match to vocal fold cover is desirable for this purpose, as material properties can affect vibration even when the implant is not placed within the lamina propria. This result is consistent with theoretical predictions and implies greater need for surgical precision in implant placement and care in material selection. PMID:22865592

  5. Medial prefrontal cortical integration of psychological stress in rats.

    PubMed

    McDougall, S J; Widdop, Robert E; Lawrence, Andrew J

    2004-11-01

    The present study aimed to determine whether the medial prefrontal cortex (mPFC) (prelimbic and infralimbic regions) is implicated in the integration of a stress response. Sprague-Dawely rats were implanted with telemetry probes and guide cannulae so that either muscimol or vehicle could be administered locally within the mPFC or dorsomedial hypothalamus (DMH). The heart rate and blood pressure of rats was continuously recorded as either muscimol or vehicle was administered centrally and rats were either exposed to restraint stress or left alone in their home cages. After the stress challenge, or equivalent period, rats that had received intra-mPFC injections were processed for immunohistochemical detection of Fos throughout the neuraxis. Bilateral microinjection of muscimol into the mPFC had no effect upon either baseline cardiovascular parameters or restraint stress-induced tachycardia or pressor responses whereas, in the DMH, pretreatment with muscimol attenuated the cardiovascular stress response. Analysis of Fos expression throughout the CNS of nonstressed rats showed no effect of muscimol injections into the mPFC on baseline expression in the nuclei examined. In contrast, rats that had received muscimol injections into their mPFC and were subsequently restrained exhibited an increase in the number of Fos-positive cells in the DMH, medial amygdala, and medial nucleus tractus solitarius as compared to vehicle-injected rats that experienced restraint stress. These results indicate that, during acute psychological stress, the mPFC does not modulate the cardiovascular system in rats but does inhibit specific subcortical nuclei to exert control over aspects of an integrated response to a stressor.

  6. The Efferent Medial Olivocochlear-Hair Cell Synapse

    PubMed Central

    Elgoyhen, Ana Belén; Katz, Eleonora

    2011-01-01

    Amplification of incoming sounds in the inner ear is modulated by an efferent pathway which travels back from the brain all the way to the cochlea. The medial olivocochlear system makes synaptic contacts with hair cells, where the neurotransmitter acetylcholine is released. Synaptic transmission is mediated by a unique nicotinic cholinergic receptor composed of α9 and α10 subunits, which is highly Ca2+ permeable and is coupled to a Ca2+-activated SK potassium channel. Thus, hyperpolarization of hair cells follows efferent fiber activation. In this work we review the literature that has enlightened our knowledge concerning the intimacies of this synapse. PMID:21762779

  7. Considerations for the Management of Medial Orbital Wall Blowout Fracture

    PubMed Central

    Park, Youngsoo; Chung, Kyu Jin

    2016-01-01

    Recently, diagnoses of and operations for medial orbital blowout fracture have increased because of the development of imaging technology. In this article, the authors review the literature, and overview the accumulated knowledge about the orbital anatomy, fracture mechanisms, surgical approaches, reconstruction materials, and surgical methods. In terms of surgical approaches, transcaruncular, transcutaneous, and transnasal endoscopic approaches are discussed. Reconstruction methods including onlay covering, inlay implantation, and repositioning methods are also discussed. Consideration and understanding of these should lead to more optimal outcomes. PMID:27218019

  8. Snapping knee caused by the thickening of the medial hamstrings.

    PubMed

    de la Hera Cremades, B; Escribano Rueda, L; Lara Rubio, A

    2016-11-17

    We report a case of symptomatic subluxation of the semitendinosus and gracilis over the medial condyle of the tibia caused by the thickening of its tendons. Snapping was reproduced on active extension. Clinical examination and, above all, dynamic ultrasound were the key for the diagnosis because other imaging tests were normal. Due to failure of conservative treatment with physiotherapy and infiltrations, surgery was undertaken, involving desinsertion and excision of distal 8cm segment of the semitendinosus and gracilis tendons. At the present time (6 months postoperatively), the patient is symptom-free and has returned to the previous normal life activities.

  9. The medial antebrachial cutaneous nerve: antidromic and orthodromic conduction studies.

    PubMed

    Seror, Paul

    2002-09-01

    Medial antebrachial cutaneous nerve (MABCN) conduction studies were performed antidromically and orthodromically in 70 control subjects to determine normal values and define the lower limits of normality. The mean sensory action potential (SAP) amplitudes were 17.7 and 17.5 microV and the sensory conduction velocities were 60 and 61 m/s, respectively, with the antidromic and orthodromic techniques. With both techniques, no SAP amplitude was lower than 6 microV. The lower limits of normal of the interside amplitude ratio were 1.66 when both techniques were used and 2.0 when only one was used.

  10. Medial ectropion repair of lower eyelids with a cicatricial component.

    PubMed

    Hesse, Richard J

    2011-01-01

    A new technique for the management of medial ectropion with a mild to moderate cicatricial component is presented that avoids the necessity for skin grafting. A subciliary incision is made inferior to the punctum and extending laterally, followed by preseptal dissection to the orbital rim. A base-up triangle of the posterior lamella is then excised lateral to the punctum. This is closed with a marginal mattress suture. Tightening of the posterior lamella in this fashion produces laxity in the anterior lamella, which can then be closed without tension, eliminating the need for skin grafting.

  11. Tibial nerve neuropathy following medial opening-wedge high tibial osteotomy-case report of a rare technical complication.

    PubMed

    Shin, Young-Soo; Sim, Hyun-Bo; Yoon, Jung-Ro

    2017-03-21

    A 63-year-old woman developed tibial nerve injury caused by an overlong K wire and 4.5-mm cortical lag screw through the first distal hole below the osteotomy during medial opening-wedge high tibial osteotomy (HTO), leading to a lack of sensation on the sole of the foot with no disturbances in motor functions. The temporary lag screw in the first distal hole below the osteotomy is often inserted by an excessive length in order to compress the potentially fractured opposite cortex. By doing so, posterior neurovascular structures including the tibial nerve and the popliteal vessels can be injured. To avoid this type of injury during medial opening-wedge HTO, proper knee position and appropriate Hohmann retractor position in combination with meticulous insertion of the K wire or screw under fluoroscopic control are essential. In addition, our study reinforces the fact that different presentations of injury to the tibial nerve should be carefully considered in the absence of common diagnostic features, including weakness of the toe flexors and posterior tibial muscle of the leg with intractable pain.

  12. Weak interactions at the SSC

    SciTech Connect

    Chanowitz, M.S.

    1986-03-01

    Prospects for the study of standard model weak interactions at the SSC are reviewed, with emphasis on the unique capability of the SSC to study the mechanism of electroweak symmetry breaking whether the associated new quanta are at the TeV scale or higher. Symmetry breaking by the minimal Higgs mechanism and by related strong interaction dynamical variants is summarized. A set of measurements is outlined that would calibrate the proton structure functions and the backgrounds to new physics. The ability to measure the three weak gauge boson vertex is found to complement LEP II, with measurements extending to larger Q/sup 2/ at a comparable statistical level in detectable decays. B factory physics is briefly reviewed as one example of a possible broad program of high statistics studies of sub-TeV scale phenomena. The largest section of the talk is devoted to the possible manifestations of symmetry breaking in the WW and ZZ production cross sections. Some new results are presented bearing on the ability to detect high mass WW and ZZ pairs. The principal conclusion is that although nonstandard model scenarios are typically more forgiving, the capability to study symmetry breaking in the standard model (and in related strong interaction dynamical variants) requires achieving the SSC design goals of ..sqrt.. s,L = 40Tev, 10/sup 33/cm/sup -2/sec/sup -1/. 28 refs., 5 figs.

  13. The weak scale from BBN

    NASA Astrophysics Data System (ADS)

    Hall, Lawrence J.; Pinner, David; Ruderman, Joshua T.

    2014-12-01

    The measured values of the weak scale, v, and the first generation masses, m u, d, e , are simultaneously explained in the multiverse, with all these parameters scanning independently. At the same time, several remarkable coincidences are understood. Small variations in these parameters away from their measured values lead to the instability of hydrogen, the instability of heavy nuclei, and either a hydrogen or a helium dominated universe from Big Bang Nucleosynthesis. In the 4d parameter space of ( m u , m d , m e , v), catastrophic boundaries are reached by separately increasing each parameter above its measured value by a factor of (1.4, 1.3, 2.5, ˜ 5), respectively. The fine-tuning problem of the weak scale in the Standard Model is solved: as v is increased beyond the observed value, it is impossible to maintain a significant cosmological hydrogen abundance for any values of m u, d, e that yield both hydrogen and heavy nuclei stability.

  14. Cognitive functioning after medial frontal lobe damage including the anterior cingulate cortex: a preliminary investigation.

    PubMed

    Baird, Amee; Dewar, Bonnie-Kate; Critchley, Hugo; Gilbert, Sam J; Dolan, Raymond J; Cipolotti, Lisa

    2006-03-01

    Two patients with medial frontal lobe damage involving the anterior cingulate cortex (ACC) performed a range of cognitive tasks, including tests of executive function and anterior attention. Both patients lesions extended beyond the ACC, therefore caution needs to be exerted in ascribing observed deficits to the ACC alone. Patient performance was compared with age and education matched healthy controls. Both patients showed intact intellectual, memory, and language abilities. No clear-cut abnormalities were noted in visuoperceptual functions. Speed of information processing was mildly reduced only in Patient 2 (bilateral ACC lesion). The patients demonstrated weak or impaired performance only on selective executive function tests. Performance on anterior attention tasks was satisfactory. We tentatively suggest that our findings are inconsistent with anterior attention theories of ACC function based on neuroimaging findings. We propose that the data may imply that the ACC does not have a central role in cognition. We speculate that our findings may be compatible with the view that the ACC integrates cognitive processing with autonomic functioning to guide behaviour.

  15. Cell Type-Specific Differences in Spike Timing and Spike Shape in the Rat Parasubiculum and Superficial Medial Entorhinal Cortex.

    PubMed

    Ebbesen, Christian Laut; Reifenstein, Eric Torsten; Tang, Qiusong; Burgalossi, Andrea; Ray, Saikat; Schreiber, Susanne; Kempter, Richard; Brecht, Michael

    2016-07-26

    The medial entorhinal cortex (MEC) and the adjacent parasubiculum are known for their elaborate spatial discharges (grid cells, border cells, etc.) and the precessing of spikes relative to the local field potential. We know little, however, about how spatio-temporal firing patterns map onto cell types. We find that cell type is a major determinant of spatio-temporal discharge properties. Parasubicular neurons and MEC layer 2 (L2) pyramids have shorter spikes, discharge spikes in bursts, and are theta-modulated (rhythmic, locking, skipping), but spikes phase-precess only weakly. MEC L2 stellates and layer 3 (L3) neurons have longer spikes, do not discharge in bursts, and are weakly theta-modulated (non-rhythmic, weakly locking, rarely skipping), but spikes steeply phase-precess. The similarities between MEC L3 neurons and MEC L2 stellates on one hand and parasubicular neurons and MEC L2 pyramids on the other hand suggest two distinct streams of temporal coding in the parahippocampal cortex.

  16. A geometric morphometric analysis of the medial tibial condyle of African hominids.

    PubMed

    Sylvester, Adam D

    2013-10-01

    Although the hominid knee has been heavily scrutinized, shape variation of the medial tibial condyle has yet to be described. Humans, chimpanzees, and gorillas differ in the shape of their medial femoral condyles and in their capacity for external and internal rotation of the tibia relative to the femur. I hypothesize that these differences should be reflected in the shape of the medial tibial condyle of these hominids. Here I use geometric morphometric techniques to uncover shape differences between the medial tibial condyles of humans, chimpanzees, and gorillas. Humans are distinguished from the other two species by having a much more oval-shaped medial tibial condyle, while those of chimpanzees and gorillas are more triangular in outline. Gorillas (especially males) are distinguished by having more concavely-curved condyles (mediolateral direction), which is interpreted as an effect of heavy loading through the medial compartment of the knee in conjunction with differences in the degree of arboreality.

  17. Joint space narrowing after partial medial meniscectomy in the anterior cruciate ligament-intact knee.

    PubMed

    Shelbourne, K Donald; Dickens, Jonathan F

    2007-09-01

    Osteoarthritis of the knee is common after total medial meniscectomy. In anterior cruciate ligament-intact knees, the reported outcomes of partial medial meniscectomy are variable. Radiographic assessment using a posteroanterior weight-bearing view is a reliable tool for detecting minor medial joint space narrowing, which may be an early sign of osteoarthritis. Studies that assessed the effect of partial medial meniscectomy found a low percentage of patients with >50% joint narrowing at 10 to 15 years after surgery. Digital radiography, using a posteroanterior weight-bearing view, is a highly sensitive method for observing minor joint space narrowing in the involved knee. A recent study showed that 88% of patients who underwent partial medial meniscectomy had joint space narrowing of <2 mm, and none had narrowing >or=2 mm, at a mean follow-up of 12 years. Subjective results after partial medial meniscectomy are favorable, with 88% to 95% of patients reporting good to excellent results.

  18. Reconstruction of medial patellofemoral ligament using quadriceps tendon combined with reconstruction of medial patellotibial ligament using patellar tendon: initial experience☆

    PubMed Central

    Hinckel, Betina Bremer; Gobbi, Riccardo Gomes; Bonadio, Marcelo Batista; Demange, Marco Kawamura; Pécora, José Ricardo; Camanho, Gilberto Luis

    2016-01-01

    Objective To describe a surgical technique for anatomical reconstruction of the medial patellofemoral ligament using the quadriceps tendon, combined with reconstruction of the medial patellotibial ligament using the patellar tendon; and to present the initial results from a case series. Method The proposed technique was used on a series of cases of patients with diagnoses of patellofemoral instability and indications for surgical treatment, who were attended by the Knee Group of HC-IOT, University of São Paulo. The following were evaluated before and after the operation: range of motion (ROM), apprehension test, lateral translation test, patellar inclination test, inverted J sign, subluxation upon extension, pain from compression of the patella and pain from contraction of the quadriceps. After the operation, the patients were asked whether any new episode of dislocation had occurred, what their degree of satisfaction with the surgery was (on a scale from 0 to 10) and whether they would be prepared to go through this operation again. Results Seven knees were operated, in seven patients, with a mean follow-up of 5.46 months (±2.07). Four patients who presented apprehension before the operation did not show this after the operation. The lateral translation test became normal for all the patients, while the patellar inclination test remained positive for two patients. The patients with an inverted J sign continued to be positive for this sign. Five patients were positive for subluxation upon extension before the operation, but all patients were negative for this after the operation. None of the patients presented any new episode of dislocation of the patella. All of them stated that they were satisfied: five gave a satisfaction score of 9 and two, a score of 10. All of them said that they would undergo the operation again. Only one patient presented a postoperative complication: dehiscence of the wound. Conclusion Reconstruction of the medial patellofemoral ligament

  19. Medial cortex strain distribution during noncemented total hip arthroplasty.

    PubMed

    Elias, J J; Nagao, M; Chu, Y H; Carbone, J J; Lennox, D W; Chao, E Y

    2000-01-01

    Intraoperative proximal femur fractures are a significant concern during noncemented total hip arthroplasty. The current study was performed to investigate the hypothesis that broaching the femur and inserting the stem without using mallet applied impact loads will reduce the risk of intraoperative fracture. Rosette strain gauges were applied to the medial and anteromedial cortex of six human anatomic specimen femurs to compare the strain distribution for broaching and stem insertion. Eight additional femurs were used to compare the strain distribution for stem insertion using impact loading and constant rate stem insertion. For the impact loading stem insertions, the soft tissues surrounding the femur were modeled. Constant rate stem insertions were performed using a mechanical testing machine. The largest strains measured at the medial and anteromedial sites primarily were aligned with the femur hoop axis. The largest strain magnitude, orientation, and sign (tensile or compressive) varied widely among femurs. The stem insertion strains were significantly larger than the broaching strains (two-way analysis of variance with replication). The impact stem insertion strains were not significantly different from the constant rate stem insertion strains. The results indicate that the femur geometry and material properties have a greater influence on the strain distribution than does the implantation technique.

  20. Perineoscrotal reconstruction using a medial circumflex femoral artery perforator flap.

    PubMed

    Karsidag, Semra; Akcal, Arzu; Sirvan, Selami Serhat; Guney, Soner; Ugurlu, Kemal

    2011-02-01

    Major scrotal defects may result from infection due to Fournier's gangrene, excision of scrotal skin diseases, traumatic avulsion of scrotal and penile skin, and genital burns. The wide spectrum of bacterial flora of the perineum, difficulty in providing immobilisation, and obtaining a natural contour of the testes make testicular cover very difficult. Various methods have been reported to cover the penoscrotal area, including skin grafting, transposing them to medial thigh skin, and use of local fasciocutaneous or musculocutaneous flaps. In this report, reconstruction using six local medial circumflex femoral artery perforator (MCFAP) flaps was undertaken in five male patients (mean age, 47 years) with complex penoscrotal or perineal wounds. The cause of the wounds in four patients was Fournier's gangrene, and was a wide papillomateous lesion in the other patient. Flap width was 6-10 cm and flap length was 10-18 cm. The results showed that a MCFAP flap provided the testes with a pliable local flap without being bulky and also protected the testicle without increasing the temperature. The other advantage of the MCFAP flap was that the donor-site scar could be concealed in the gluteal crease. Our results demonstrated that the MCFAP flap is an ideal local flap for covering penoscrotal defects.

  1. Medial prefrontal cortex role in recognition memory in rodents.

    PubMed

    Morici, Juan Facundo; Bekinschtein, Pedro; Weisstaub, Noelia V

    2015-10-01

    The study of the neurobiology of recognition memory, defined by the integration of the different components of experiences that support recollection of past experiences have been a challenge for memory researches for many years. In the last twenty years, with the development of the spontaneous novel object recognition task and all its variants this has started to change. The features of recognition memory include a particular object or person ("what"), the context in which the experience took place, which can be the arena itself or the location within a particular arena ("where") and the particular time at which the event occurred ("when"). This definition instead of the historical anthropocentric one allows the study of this type of episodic memory in animal models. Some forms of recognition memory that require integration of different features recruit the medial prefrontal cortex. Focusing on findings from spontaneous recognition memory tasks performed by rodents, this review concentrates on the description of previous works that have examined the role that the medial prefrontal cortex has on the different steps of recognition memory. We conclude that this structure, independently of the task used, is required at different memory stages when the task cannot be solved by a single item strategy.

  2. Clinical results in reconstruction of medial patellofemoral ligament

    PubMed Central

    Irigoitia, Nicolas Alejandro; Catan, Agustín Felipe; Arroquy, Damián; Guiñazu, Jorge; Vilaseca, Tomas; Nazur, Gabriel; Bisso, Martín Carboni

    2017-01-01

    Background: The reconstruction of the medial patellofemoral ligament (MPFL) is the most suitable treatment for the patellar instability at the present in patients with two or more episodes of dislocation or only one with condral lesion. This is because it is the principal medial stabilizer of the patella. This process could be supplemented with an osseous correction as tibial tuberosity transference. Objectives: assess the clinical results of the reconstruction of the MPLF in patients with patellar instability. Study Design: Case series, level of evidence IV. Methods: We enroll all patients with this procedure between form April 2011 to February 2015, the sample has 27 reconstruction in 25 patients, who has two or more episodes of patellar dislocation. The graft used was gracilis tendon, set with suture anchor, and tibial tuberosity transfer in 9 patients who need an osseous procedure. Results: The average Kujala score was 90,1 points ( 64-100). Was necessary tibial tuberosity transference in one third of se sample. And in those patients there no difference compared with the isolated reconstruction.There was no episode of patellar dislocation or a second surgical time in the sample. Conclusion: The reconstruction of MPLF show excellent clinical outcomes in a short and medium terms , with 0% of dislocation and no second surgical time, in this kind of patients.

  3. The medial gastrocnemius muscle attenuates force fluctuations during plantar flexion.

    PubMed

    Shinohara, Minoru; Yoshitake, Yasuhide; Kouzaki, Motoki; Fukunaga, Tetsuo

    2006-02-01

    Force fluctuations during steady contractions of multiple agonist muscles may be influenced by the relative contribution of force by each muscle. The purpose of the study was to compare force fluctuations during steady contractions performed with the plantar flexor muscles in different knee positions. Nine men (25.8+/-5.1 years) performed steady contractions of the plantar flexor muscles in the knee-flexed and knee-extended (greater involvement of the gastrocnemii muscles) positions. The maximal voluntary contraction (MVC) force was 32% greater in the knee-extended position compared with the knee-flexed position. The target forces were 2.5-10% MVC force in the respective position. The amplitude of electromyogram in the medial gastrocnemius muscle was greater in the knee-extended position (10.50+/-9.80%) compared with the knee-flexed position (1.26+/-1.15%, P<0.01). The amplitude of electromyogram in the soleus muscle was not influenced by the knee position. The amplitude of electromyogram in the lateral gastrocnemius and tibialis anterior muscles was marginal and unaltered with knee position. At the same force (in Newtons), the standard deviation of force was lower in the knee-extended position compared with the knee-flexed position. These results indicate that force fluctuations during plantar flexion are attenuated with greater involvement of the medial gastrocnemius muscle.

  4. Function of the medial meniscus in force transmission and stability.

    PubMed

    Walker, Peter S; Arno, Sally; Bell, Christopher; Salvadore, Gaia; Borukhov, Ilya; Oh, Cheongeun

    2015-06-01

    We studied the combined role of the medial meniscus in distributing load and providing stability. Ten normal knees were loaded in combinations of compressive and shear loading as the knee was flexed over a full range. A digital camera tracked the motion, from which femoral-tibial contacts were determined by computer modelling. Load transmission was determined from the Tekscan for the anterior horn, central body, posterior horn, and the uncovered cartilage in the centre of the meniscus. For the three types of loading; compression only, compression and anterior shear, compression and posterior shear; between 40% and 80% of the total load was transmitted through the meniscus. The overall average was 58%, the remaining 42% being transmitted through the uncovered cartilage. The anterior horn was loaded only up to 30 degrees flexion, but played a role in controlling anterior femoral displacement. The central body was loaded 10-20% which would provide some restraint to medial femoral subluxation. Overall the posterior horn carried the highest percentage of the shear load, especially after 30 degrees flexion when a posterior shear force was applied, where the meniscus was estimated to carry 50% of the shear force. This study added new insights into meniscal function during weight bearing conditions, particularly its role in early flexion, and in transmitting shear forces.

  5. Modified endoscopic medial maxillectomy for zygomatic implant salvage

    PubMed Central

    Tajudeen, Bobby A.; Adappa, Nithin D.; Palmer, James N.

    2016-01-01

    Objectives: Odontogenic chronic rhinosinusitis (CRS) is an epidemiologically important disease process due, in part, to the increasingly commonplace use of dental restorative procedures such as zygomatic implantation. Traditional management of this clinical entity typically entails extraction of the infected hardware via an open or endoscopic approach. We describe a novel management strategy of odontogenic CRS following bilateral zygomatic implantation for oral rehabilitation that we surgically salvaged via a modified endoscopic medial maxillectomy. Methods: We describe the presentation and management of a case of metachronous development of bilateral CRS subsequent to zygomatic implantation. Results: The patient's postoperative course was characterized by marked endoscopic, radiologic, and symptomatic improvement as measured by the 22-item Sino-Nasal Outcome Test. Conclusion: We describe a novel treatment strategy for the management of odontogenic sinusitis resulting from erroneous zygomatic implant placement. Modified endoscopic medial maxillectomy in this clinical context facilitates mucosal normalization of the affected sinus, while permitting preservation of oral function through salvage of the displaced implant. PMID:28107147

  6. Medial Elbow Exposure for Coronoid Fractures: FCU-Split Versus Over-the-Top

    DTIC Science & Technology

    2013-12-01

    margin of the mass anteriorly) was split and the pronator teres was released from the medial epicondyle and reflected off the anterior elbow capsule and...ORIGINAL ARTICLE Medial Elbow Exposure for Coronoid Fractures: FCU-Split Versus Over-the-Top Jeannie Huh, MD,* Chad A. Krueger, MD,* Michael J...fractures is unknown. The purpose of this study was to quantitatively compare the osseous and ligamentous exposure of the medial elbow using the flexor

  7. The Mechanical Benefit of Medial Support Screws in Locking Plating of Proximal Humerus Fractures

    PubMed Central

    Liu, Yanjie; Pan, Yao; Zhang, Wei; Zhang, Changqing; Zeng, Bingfang; Chen, Yunfeng

    2014-01-01

    Background The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures. Methods Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. Results Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001). When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P≤0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. Conclusions Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure. PMID:25084520

  8. A man with worsening weakness.

    PubMed

    Proietti, G; Puliti, M; Tulli, F; Silvestri, M

    1999-01-01

    The contemporary presence of organomegaly, skin manifestations, polyneuropathy, endocrinopathy and monoclonal component characterises the POEMS syndrome, often associated with osteosclerotic myeloma and Castelman's disease and more frequent in the Japanese. Clinical manifestations seem to be related to the production of many interleukins, mainly IL-1, IL-6 and TNF. Several endocrinopathies have been described, the most frequent being diabetes. Only one previous case of hypoparathyroidism associated with the syndrome has been described in medical reviews. Polyneuropathy is often sensitivo-motory and skin disease accounts for Raynaud phenomenon, skin pigmentation, hypertricosis and others. We describe the case of a 74-year-old man who underwent clinical examination for weakness mainly in the legs. Clinical and instrumental data showed rhabdomyolysis due to hypoparathyroidism. The contemporary presence of a monoclonal band of light chains on proteic electrophoresis, organomegaly and distal leg neuropathy allowed us to make a diagnosis of POEMS syndrome.

  9. Weakly nonlinear magnetohydrodynamic wave interactions

    SciTech Connect

    Webb, G.M.; Brio, M.; Kruse, M.T.; Zank, G.P.

    1999-06-01

    Equations describing weakly nonlinear magnetohydrodynamic (MHD) wave interactions in one Cartesian space dimension are discussed. For wave propagation in uniform media, the wave interactions of interest consist of: (a) three-wave resonant interactions in which high frequency waves, may evolve on long space and time scales if the wave phases satisfy the resonance conditions; (b) Burgers self-wave steepening for the magnetoacoustic waves, and (c) mean wave field effects, in which a particular wave interacts with the mean wave field of the other waves. For wave propagation in non-uniform media, further linear wave mixing terms appear in the equations. The equations describe four types of resonant triads: slow-fast magnetosonic wave interaction; Alfv{acute e}n-entropy wave interaction; Alfv{acute e}n-magnetosonic wave interaction; and magnetosonic-entropy wave interaction. The formalism is restricted to coherent wave interactions. {copyright} {ital 1999 American Institute of Physics.}

  10. Medial tibial pain. A prospective study of its cause among military recruits.

    PubMed

    Milgrom, C; Giladi, M; Stein, M; Kashtan, H; Margulies, J; Chisin, R; Steinberg, R; Swissa, A; Aharonson, Z

    1986-12-01

    In a prospective study of 295 infantry recruits during 14 weeks of basic training, 41% had medial tibial pain. Routine scintigraphic evaluation in cases of medial tibial bone pain showed that 63% had abnormalities. A stress fracture was found in 46%. Only two patients had periostitis. None had ischemic medial compartment syndrome. Physical examination could not differentiate between cases with medial tibial bone pain secondary to stress fractures and those with scintigraphically normal tibias. When both pain and swelling were localized in the middle one-third of the tibia, the lesion most likely proved to be a stress fracture.

  11. The significance of medial sural artery integrity in popliteal artery trauma: a case report.

    PubMed

    Tzilalis, V D; Georgiadis, G S; Papas, T T; Arvanitis, D P; Lazarides, M K

    2005-12-01

    Two patients with popliteal artery trauma who underwent secondary amputations due to refractory calf sepsis despite a patent arterial repair are presented in this case report. The medial sural artery, the main arterial supply of the medial head of the gastrocnemius, was surgically severed in both patients owing to the use of a continuous medial incision from the supra level to infragenicular level. The compromised arterial supply of the medial head of the gastrocnemius muscle may have contributed to the devitalization of the muscle and the subsequent calf sepsis, and it is speculated that this was related to the unfavorable outcome.

  12. The medial malleolus osteoligamentous complex and its role in ankle fractures.

    PubMed

    Davidovitch, Roy I; Egol, Kenneth A

    2009-01-01

    Ankle stability in ankle fractures is dependent on multiple factors. The medial malleolus and the associated deltoid ligament provide for ankle stability on the medial side. Over the years, the relative importance of this medial malleolar osteoligamentous complex (MMOLC) has been debated. This review will describe the evolution of ankle fracture surgery from the perspective of the contribution of the MMOLC to re-establishing ankle stability. Also discussed are the surgical and nonsurgical treatment options, various presentations of medial sided injuries in ankle fractures, and, finally, current recommendations for fixation.

  13. Simulations of foot stability during gait characteristic of ankle dorsiflexor weakness in the elderly.

    PubMed

    Gefen, A

    2001-12-01

    Falls are common among the elderly and often cause injuries. They most frequently occut during walking and are associated with the chronic deterioration in neuromuscular and sensory systems, as well as with ankle dorsiflexor muscular weakness and lowered endurance of these muscles to fatigue. In the present study, a three-dimensional (3-D) finite element model of the structure of the foot was utilized to determine the effects of ankle dorsiflexor muscle weakness on the structural stability of the foot and, consequently, on the risk of falls during gait. The medial-lateral tendency of instability of the foot during gait in such conditions of weakness was analyzed by means of this model to identify the most important muscles used in controlling foot stability in affected individuals. The values of the eccentricity of the center of pressure under the heel during foot placement were used to indicate the degree of foot stability. The computational analysis indicated that it is the tibialis anterior muscle's weakness that dramatically decreases foot stability. Clinical investigation is now needed to correlate the significance of tibialis anterior muscle weakness with other known risk factors affecting the tendency to falls among the elderly, e.g., deterioration of sensory abilities. Rehabilitation practitioners and physical therapists may apply the present analytic approach to evaluate the stability of a foot before treatment and compare the predicted with the actual therapeutic results in terms of optimization of foot-ground pressure.

  14. A Case of Spontaneous Osteonecrosis of the Knee with Early and Simultaneous Involvement of the Medial Femoral Condyle and Medial Tibial Plateau

    PubMed Central

    Fujita, Shinya; Arai, Yuji; Honjo, Kuniaki; Nakagawa, Shuji; Kubo, Toshikazu

    2016-01-01

    Spontaneous osteonecrosis of the knee (SPONK) usually involves a single condyle, most often the medial femoral condyle (MFC). Involvement of the medial tibial plateau (MTP) is less common, occurring in about 2% of knees with SPONK. Early onset SPONK on the ipsilateral side of the medial compartment is very rare, with, to our knowledge, only four cases reported to date. We describe a very rare case of SPONK with early simultaneous development in the MFC and MTP. Serial plain radiographs and magnetic resonance imaging showed that SPONK in both condyles followed a similar progressive course. The pathological findings in these lesions were similar to those observed in subchondral insufficiency fractures. PMID:27242941

  15. Deterministic weak localization in periodic structures.

    PubMed

    Tian, C; Larkin, A

    2005-12-09

    In some perfect periodic structures classical motion exhibits deterministic diffusion. For such systems we present the weak localization theory. As a manifestation for the velocity autocorrelation function a universal power law decay is predicted to appear at four Ehrenfest times. This deterministic weak localization is robust against weak quenched disorders, which may be confirmed by coherent backscattering measurements of periodic photonic crystals.

  16. Weak D in the Tunisian population

    PubMed Central

    Ouchari, Mouna; Romdhane, Houda; Chakroun, Taher; Abdelkefi, Saida; Houissa, Batoul; Hmida, Slama; Yacoub, Saloua Jemni

    2015-01-01

    Background More than 90 weak D types have been discovered to date. As there are no published data on the frequencies of weak D types in the Tunisian population, the aim of this study was to determine the composition of weak D alleles in our population. Material and methods Blood samples from 1777 D+ and 223 D− blood donors were tested for markers 809G, 1154C, 8G, 602G, 667G, 446A, and 885T relative to translation start codon by polymerase chain reaction with sequence-specific primers to estimate the frequencies of weak D type 1, weak D type 2, weak D type 3, weak D type 4, weak D type 5 and weak D type 11 in our population. Twenty-three samples with positive reactions were re-evaluated by DNA sequencing of RHD exons 1–10 and adjacent intronic sequences. Results Among the D+ donor cohort, weak D type 4 was the most prevalent allele (n=33, 1.2%) followed by weak D type 2 (n=6, 0.17%), weak D type 1 (n=4, 0.11%), and weak D type 5 (n=1, 0.28%) and weak D type 11 (n=1, 0.28%). RHD sequencing identified a weak D type 4.0 allele in all 19 samples tested. Among the D− pool, comprising 223 samples, we detected one sample with weak D type 4.0 associated with a C+c+E−e+ phenotype which had been missed by routine serological methods. Discussion Weak D type 4.0 appears to be the most prevalent weak D in our population. However, all samples must be sequenced in order to determine the exact subtype of weak D type 4, since weak D type 4.2 has considerable clinical importance, being associated with anti-D alloimmunisation. One case of weak D type 4 associated with dCe in trans had been missed by serology, so quality control of serological tests should be developed in our country. PMID:25369614

  17. Comparison of Medial and Lateral Meniscus Root Tears.

    PubMed

    Koo, Ji Hyun; Choi, Sang-Hee; Lee, Seung Ah; Wang, Joon Ho

    2015-01-01

    The meniscus root plays an essential role in maintaining the circumferential hoop tension and preventing meniscal displacement. Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. However, few studies have directly compared the medial and lateral root tears. To assess the prevalence of meniscal extrusion and its relationship with clinical features in medial and lateral meniscus root tears, we performed a retrospective review of the magnetic resonance imaging (MRI) results of 42 knee patients who had meniscus posterior horn root tears and who had undergone arthroscopic operations. The presence of meniscal extrusion was evaluated and the exact extent was measured from the tibial margin. The results were correlated with arthroscopic findings. Clinical features including patients' ages, joint abnormalities, and previous trauma histories were evaluated. Twenty-two patients had medial meniscus root tears (MMRTs) and twenty patients had lateral meniscus root tears (LMRTs). Meniscal extrusion was present in 18 MMRT patients and one LMRT patient. The mean extent of extrusion was 4.2mm (range, 0.6 to 7.8) in the MMRT group and 0.9mm (range, -1.9 to 3.4) in the LMRT group. Five patients with MMRT had a history of trauma, while 19 patients with LMRT had a history of trauma. Three patients with MMRT had anterior cruciate ligament (ACL) tears, while 19 patients with LMRT had ACL tears. The mean age of the patients was 52 years (range: 29-71 years) and 30 years (range: 14-62 years) in the MMRT and LMRT group, respectively. There was a significant correlation between a MMRT and meniscal extrusion (p<0.0001), and between an ACL tear and LMRT (p<0.0001). A history of trauma was significantly common in LMRT (p<0.0001). LMRT patients were significantly younger than MMRT patients (p<0.0001). Kellgren-Lawrence (K-L) grade differed significantly between MMRT and LMRT group (p<0.0001). Meniscal extrusion is common in

  18. The properties of the extraocular muscles of the frog. I. Mechanical properties of the isolated superior oblique and superior rectus muscles.

    PubMed

    Asmussen, G

    1978-01-01

    The mechanical properties of two extraocular muscles (superior oblique and superior rectus muscles) of the frog were studied and compared with those of a frog's skeletal muscle (iliofibularis muscle) which contains the same types of muscle fibres as the oculorotatory muscles. The extraocular muscles are very fast twitching muscles. They exhibit a smaller contraction time, a smaller half-relaxation time, a higher fusion frequency, and a lower twitch-tetanus ratio than the skeletal muscles. The maximum isometric tetanic tension produced per unit cross-sectional area is lower in the extraocular muscles than in skeletal muscles. However, the extraocular muscles show a higher fatigue resistance than the skeletal muscles. With respect to the dynamic properties there are some differences between the various oculorotatory muscles of the frog. The superior rectus muscle exhibits a faster time-course of the contraction, a higher fusion frequency, and a higher fatigability than the superior oblique muscle. An increase of the extracellular K+-concentration evokes sustained contractures not only in the extraocular muscles but also in the iliofibularis muscle; between these muscles there are no striking differences in the mechanical threshold of the whole muscle preparation. The mechanical threshold depends on the Ca++-concentration of the bathing solution and it is found in a range between 12.5 and 17.5 mM K+ in a normal Ringer solution containing 1.8 mM Ca++. The static-mechanical properties of the extraocular muscles of the frog and the dependence of the active developed tension on the muscle extension are very similar to those which are known to exist in the extraocular muscles of other vertebrates. In tetanic activated frog's oculorotatory muscles a linear relationship exists between length and tension. A variation of the stimulation frequency does not change the slope of this curve but causes parallel shifts of the curve. The peculiar properties of the extraocular muscles

  19. Radiological analysis of the medial epicondyle in the adolescent throwing athlete

    PubMed Central

    Ng, Wuey Min; Chan, Chee Ken; Takahashi, Norimasa; Kawai, Nobuaki; Teh, Kok Kheng; Saravana, R; Sugaya, Hiroyuki

    2017-01-01

    INTRODUCTION Injuries to the medial structures of the elbow due to overhead throwing games are well documented. However, variations of medial epicondyles are not well described, especially in athletes with fused medial epicondyles. In this study, we evaluated variations in the medial epicondyle of baseball players who were aged 15–17 years and had fused epicondyles. METHODS In this cross-sectional observational study, 155 skeletally mature baseball players with unilateral medial elbow pain and 310 elbow radiographs were reviewed by two independent reviewers. The medial epicondyles were categorised into three groups: normal, elongated or separated. RESULTS Among the 155 patients, 65 (41.9%) had normal epicondyles, 41 (26.5%) had elongated epicondyles and 49 (31.6%) had separated epicondyles. The medial epicondyle was larger on the dominant arm for 125 (80.6%) patients; the mean surface area on the dominant arm was 222.50 ± 45.77 mm2, while that of the non-dominant arm was 189.14 ± 39.56 mm2 (p < 0.01). Among the three categories of medial epicondyles, separated epicondyles had the largest surface area, followed by elongated and normal epicondyles. CONCLUSION Medial epicondyles in adolescent throwing athletes can be categorised into three different groups according to their shape (normal, elongated and separated). We observed a correlation between the shape and the surface area of the medial epicondyle in adolescent throwing athletes, with separated medial epicondyles having the largest surface area. Further studies and follow-up are needed to determine the prognostic value and clinical significance of these morphological variations. PMID:26976222

  20. Weakly relativistic dispersion of Bernstein waves

    NASA Technical Reports Server (NTRS)

    Robinson, P. A.

    1988-01-01

    Weakly relativistic effects on the dispersion of Bernstein waves are investigated for waves propagating nearly perpendicular to a uniform magnetic field in a Maxwellian plasma. Attention is focused on those large-wave-vector branches that are either weakly damped or join continuously onto weakly damped branches since these are the modes of most interest in applications. The transition between dispersion at perpendicular and oblique propagation is examined and major weakly relativistic effects can dominate even in low-temperature plasmas. A number of simple analytic criteria are obtained which delimit the ranges of harmonic number and propagation angle within which various types of weakly damped Bernstein modes can exist.

  1. Sports injury to a bipartite medial cuneiform in a child.

    PubMed

    Eves, Timothy B; Ahmad, Mudussar A; Oddy, Michael J

    2014-01-01

    We report the case of an 11-year-old boy who had sustained a soccer injury to his mid-foot. Plain radiography did not reveal any fracture to account for the severity of his symptoms or his inability to bear weight. Magnetic resonance imaging was undertaken and demonstrated the medial cuneiform to be a bipartite bone consisting of 2 ossicles connected by a synchondrosis. No acute fracture or diastasis of the bipartite bone was demonstrated; however, significant bone marrow edema was noted, corresponding to the site of the injury and his clinical point bony tenderness. This anatomic variant should be considered as a rare differential diagnosis in the skeletally immature foot. The injury was treated nonoperatively with a non-weightbearing cast and pneumatic walker immobilization, with successful resolution of his symptoms and a return to sports activity by 4 months after injury.

  2. The Vascularized Medial Femoral Corticoperiosteal Flap for Thumb Reconstruction

    PubMed Central

    Amin, Kavit; Darhouse, Nagham; Sivakumar, Bran; Floyd, David

    2015-01-01

    Summary: We present an interesting method of shaping a vascularized medial femoral condyle (MFC) flap into a “neophalanx” for phalangeal reconstruction. Our patient presented with limited strength and function secondary to fracture nonunion of the proximal phalanx of the dominant thumb. Following excision of the pseudarthrosis, an MFC corticoperiosteal flap was harvested, sculpted into a prism shape and inset. The superomedial genicular pedicle was anastomosed to the princeps pollicis artery and a cephalic tributary. On follow-up, new bone growth was seen on radiographs and the patient had substantially improved function, with full metacarpophalangeal extension, a Kapandji score of 9, and a markedly reduced Disabilities of the Arm, Shoulder and Hand score of 2.68. The MFC flap is useful for reconstruction of bony defects, with minimal donor morbidity. This versatile vascularized flap can be crafted to requisite shapes and is useful for small defects in the hand, including phalangeal reconstruction. PMID:26495205

  3. Medial temporal lobe memory in childhood: Developmental transitions

    PubMed Central

    Townsend, Elise L.; Richmond, Jenny L.; Vogel-Farley, Vanessa K.; Thomas, Kathleen

    2009-01-01

    The medial temporal lobes (MTL) support declarative memory and mature structurally and functionally during the postnatal years in humans. Although recent work has addressed the development of declarative memory in early childhood, less is known about continued development beyond this period of time. The purpose of this investigation was to explore MTL-dependent memory across middle childhood. Children (6 – 10 years old) and adults completed two computerized tasks, place learning (PL) and transitive inference (TI), that each examined relational memory, as well as the flexible use of relational learning. Findings suggest that the development of relational memory precedes the development of the ability to use relational knowledge flexibly in novel situations. Implications for the development of underlying brain areas and ideas for future neuroimaging investigations are discussed. PMID:20712740

  4. Failed medial patellofemoral ligament reconstruction: Causes and surgical strategies

    PubMed Central

    Sanchis-Alfonso, Vicente; Montesinos-Berry, Erik; Ramirez-Fuentes, Cristina; Leal-Blanquet, Joan; Gelber, Pablo E; Monllau, Joan Carles

    2017-01-01

    Patellar instability is a common clinical problem encountered by orthopedic surgeons specializing in the knee. For patients with chronic lateral patellar instability, the standard surgical approach is to stabilize the patella through a medial patellofemoral ligament (MPFL) reconstruction. Foreseeably, an increasing number of revision surgeries of the reconstructed MPFL will be seen in upcoming years. In this paper, the causes of failed MPFL reconstruction are analyzed: (1) incorrect surgical indication or inappropriate surgical technique/patient selection; (2) a technical error; and (3) an incorrect assessment of the concomitant risk factors for instability. An understanding of the anatomy and biomechanics of the MPFL and cautiousness with the imaging techniques while favoring clinical over radiological findings and the use of common sense to determine the adequate surgical technique for each particular case, are critical to minimizing MPFL surgery failure. Additionally, our approach to dealing with failure after primary MPFL reconstruction is also presented. PMID:28251062

  5. Medial prefrontal cortex predicts internally driven strategy shifts

    PubMed Central

    Schuck, Nicolas W.; Gaschler, Robert; Wenke, Dorit; Heinzle, Jakob; Frensch, Peter A.; Haynes, John-Dylan; Reverberi, Carlo

    2015-01-01

    Summary Many daily behaviors require us to actively focus on the current task and ignore all other distractions. Yet, ignoring everything else might hinder the ability to discover new ways to achieve the same goal. Here, we studied the neural mechanisms that support the spontaneous change to better strategies while an established strategy is executed. Multivariate neuroimaging analysis showed that before the spontaneous change to an alternative strategy, medial prefrontal cortex (MPFC) encoded information that was irrelevant for the current strategy but necessary for the later strategy. Importantly, this neural effect was related to future behavioral changes: information encoding in MPFC was changed only in participants who eventually switched their strategy and started before the actual strategy change. This allowed us to predict spontaneous strategy shifts ahead of time. These findings suggest that MPFC might internally simulate alternative strategies and sheds new light on the organization of PFC. PMID:25819613

  6. A Universe without Weak Interactions

    SciTech Connect

    Harnik, Roni; Kribs, Graham D.; Perez, Gilad

    2006-04-07

    A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.

  7. Weak percolation on multiplex networks

    NASA Astrophysics Data System (ADS)

    Baxter, Gareth J.; Dorogovtsev, Sergey N.; Mendes, José F. F.; Cellai, Davide

    2014-04-01

    Bootstrap percolation is a simple but nontrivial model. It has applications in many areas of science and has been explored on random networks for several decades. In single-layer (simplex) networks, it has been recently observed that bootstrap percolation, which is defined as an incremental process, can be seen as the opposite of pruning percolation, where nodes are removed according to a connectivity rule. Here we propose models of both bootstrap and pruning percolation for multiplex networks. We collectively refer to these two models with the concept of "weak" percolation, to distinguish them from the somewhat classical concept of ordinary ("strong") percolation. While the two models coincide in simplex networks, we show that they decouple when considering multiplexes, giving rise to a wealth of critical phenomena. Our bootstrap model constitutes the simplest example of a contagion process on a multiplex network and has potential applications in critical infrastructure recovery and information security. Moreover, we show that our pruning percolation model may provide a way to diagnose missing layers in a multiplex network. Finally, our analytical approach allows us to calculate critical behavior and characterize critical clusters.

  8. Testing the weak equivalence principle

    NASA Astrophysics Data System (ADS)

    Nobili, Anna M.; Comandi, Gian Luca; Pegna, Raffaello; Bramanti, Donato; Doravari, Suresh; Maccarone, Francesco; Lucchesi, David M.

    2010-01-01

    The discovery of Dark Energy and the fact that only about 5% of the mass of the universe can be explained on the basis of the current laws of physics have led to a serious impasse. Based on past history, physics might indeed be on the verge of major discoveries; but the challenge is enormous. The way to tackle it is twofold. On one side, scientists try to perform large scale direct observations and measurements - mostly from space. On the other, they multiply their efforts to put to the most stringent tests ever the physical theories underlying the current view of the physical world, from the very small to the very large. On the extremely small scale very exciting results are expected from one of the most impressive experiments in the history of mankind: the Large Hadron Collider. On the very large scale, the universe is dominated by gravity and the present impasse undoubtedly calls for more powerful tests of General Relativity - the best theory of gravity to date. Experiments testing the Weak Equivalence Principle, on which General Relativity ultimately lies, have the strongest probing power of them all; a breakthrough in sensitivity is possible with the “Galileo Galilei” (GG) satellite experiment to fly in low Earth orbit.

  9. The topology of dermatomal projection in the medial lemniscal system

    PubMed Central

    Werner, Gerhard; Whitsel, Barry L.

    1967-01-01

    1. The topographic organization of first order afferent fibres in the lumbar, sacral and coccygeal dorsal roots, and in the fasciculus gracilis was studied in squirrel monkeys. 2. At the entry zone, progressing from caudal to rostral, dorsal root filaments receive fibres from tail and hind-limb receptive fields which serially overlap and describe a spiral-shaped trajectory. The latter starts with tail, progresses post-axially towards the foot, crosses the foot from lateral to medial, and ascends the preaxial leg. 3. In the fasciculus gracilis, this arrangement of fibres at the dorsal root entry zone is preserved in its entirety. It assumes the form of a fibre lamination, with the most caudal dorsal root fibres occupying a dorso-medial location; further rostral dorsal root fibres come to lie more ventrolaterally. 4. Dorsum and sole of foot project in an overlapping and interdigitating manner to the fibre lamina of the 7th lumber dermatome in the fasciculus gracilis. Thereby, dorsum and sole of foot behave in the projection as if they were one and the same surface. 5. The argument is presented that the foot and its projection on to the cross-sectional plane of the dorsal funiculus are topologically equivalent and that the hind-limb as a whole and its projection are not. On the other hand, homotopic mapping of the foot together with the sequential fibre organization in the dorsal funiculus enable many more types of closed curves on the body surface to remain arc-wise connected in the projection than would otherwise be possible. ImagesPlate 1 PMID:4963874

  10. Proximal Scaphoid Arthroplasty Using the Medial Femoral Trochlea Flap

    PubMed Central

    Higgins, James P.; Burger, Heinze K.

    2013-01-01

    Background The medial trochlea of the femur (medial femoral trochlea, MFT) provides a source of convex osteocartilaginous vascularized bone that has been demonstrated to have a similar contour to the proximal scaphoid. This provides a potential solution for difficult recalcitrant proximal pole scaphoid nonunions. Materials and Methods Sixteen consecutive patients who underwent MFT proximal scaphoid arthroplasty were reviewed. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months. The results of this cohort were previously reported in detail but are summarized herein. Description of Technique The ability to reconstruct both bone and cartilage of the nonunion enables the surgeon to resect the nonunited proximal pole to prepare for scaphoid reconstruction. A segment of osteocartilaginous MFT is harvested in dimensions required by the scaphoid defect. The MFT segment is harvested on the transverse branch of the descending geniculate vessels. Fixation may be achieved with ease due to the size of the reconstructed segment. Results Computed tomography imaging demonstrated 15 of 16 reconstructed scaphoids achieving osseous union. Follow-up range of motion (ROM) of the wrist averaged 46.0° extension (range 28-80°) and 43.8° flexion (range 10-80°), which was similar to preoperative (average 45.7° extension and 43.0° flexion). Scapholunate angles remained unaffected (51.6° preoperatively and 48.6° postoperatively), indicating preservation of carpal relationships. Conclusions Vascularized MFT flaps provide a useful tool in the treatment of difficult proximal pole scaphoid nonunions. Early follow-up demonstrates high rate of achieving union with acceptable ROM and good pain relief. PMID:24436821

  11. Medialized Versus Lateralized Center of Rotation in Reverse Shoulder Arthroplasty.

    PubMed

    Streit, Jonathan J; Shishani, Yousef; Gobezie, Reuben

    2015-12-01

    Reverse shoulder arthroplasty may be performed using components that medialize or lateralize the center of rotation. The purpose of this prospective study was to directly compare 2 reverse shoulder arthroplasty designs. Two treatment groups and 1 control group were identified. Group I comprised 9 patients using a medialized Grammont-style (GRM) prosthesis with a neck-shaft angle of 155°. Group II comprised 9 patients using a lateralized (LAT) prosthesis with a neck-shaft angle of 135°. Pre- and postoperative assessment of range of motion, American Shoulder and Elbow Surgeons score, and visual analog scale pain score were performed. Radiographic measurements of lateral humeral offset and acromiohumeral distance were compared. The GRM prosthesis achieved greater forward flexion (143.9° vs 115.6°; P=.05), whereas the LAT achieved greater external rotation (35.0° vs 28.3°; P=.07). The lateral humeral offset was greater for the LAT prosthesis compared with the GRM prosthesis, but this distance was not significantly different from that found in the control group. The acromiohumeral distance was significantly greater in the GRM prosthesis group compared with both the LAT and the control groups. The results of this study confirm that different reverse shoulder arthroplasty designs produce radiographically different anatomy. Whereas the GRM prosthesis significantly alters the anatomy of the shoulder, the LAT design can preserve some anatomic relationships found in the normal shoulder. The clinical outcomes indicate that this may have an effect on range of motion, with traditional designs achieving greater forward flexion and lateralized designs achieving greater external rotation.

  12. Reversed Procrastination by Focal Disruption of Medial Frontal Cortex.

    PubMed

    Jha, Ashwani; Diehl, Beate; Scott, Catherine; McEvoy, Andrew W; Nachev, Parashkev

    2016-11-07

    An enduring puzzle in the neuroscience of voluntary action is the origin of the remarkably wide dispersion of the reaction time distribution, an interval far greater than is explained by synaptic or signal transductive noise [1, 2]. That we are able to change our planned actions-a key criterion of volition [3]-so close to the time of their onset implies decision-making must reach deep into the execution of action itself [4-6]. It has been influentially suggested the reaction time distribution therefore reflects deliberate neural procrastination [7], giving alternative response tendencies sufficient time for fair competition in pursuing a decision threshold that determines which one is behaviorally manifest: a race model, where action selection and execution are closely interrelated [8-11]. Although the medial frontal cortex exhibits a sensitivity to reaction time on functional imaging that is consistent with such a mechanism [12-14], direct evidence from disruptive studies has hitherto been lacking. If movement-generating and movement-delaying neural substrates are closely co-localized here, a large-scale lesion will inevitably mask any acceleration, for the movement itself could be disrupted. Circumventing this problem, here we observed focal intracranial electrical disruption of the medial frontal wall in the context of the pre-surgical evaluation of two patients with epilepsy temporarily reversing such hypothesized procrastination. Effector-specific behavioral acceleration, time-locked to the period of electrical disruption, occurred exclusively at a specific locus at the ventral border of the pre-supplementary motor area. A cardinal prediction of race models of voluntary action is thereby substantiated in the human brain.

  13. Left medial orbitofrontal cortex volume correlates with skydive-elicited euphoric experience.

    PubMed

    Carlson, Joshua M; Cha, Jiook; Fekete, Tomer; Greenberg, Tsafrir; Mujica-Parodi, Lilianne R

    2016-11-01

    The medial orbitofrontal cortex has been linked to the experience of positive affect. Greater medial orbitofrontal cortex volume is associated with greater expression of positive affect and reduced medial orbital frontal cortex volume is associated with blunted positive affect. However, little is known about the experience of euphoria, or extreme joy, and how this state may relate to variability in medial orbitofrontal cortex structure. To test the hypothesis that variability in euphoric experience correlates with the volume of the medial orbitofrontal cortex, we measured individuals' (N = 31) level of self-reported euphoria in response to a highly anticipated first time skydive and measured orbitofrontal cortical volumes with structural magnetic resonance imaging. Skydiving elicited a large increase in self-reported euphoria. Participants' euphoric experience was predicted by the volume of their left medial orbitofrontal cortex such that, the greater the volume, the greater the euphoria. Further analyses indicated that the left medial orbitofrontal cortex and amygdalo-hippocampal complex independently explain variability in euphoric experience and that medial orbitofrontal cortex volume, in conjunction with other structures within the mOFC-centered corticolimbic circuit, can be used to predict individuals' euphoric experience.

  14. Anterolateral Versus Medial Plating of Distal Extra-articular Tibia Fractures: A Biomechanical Model.

    PubMed

    Pirolo, Joseph M; Behn, Anthony W; Abrams, Geoffrey D; Bishop, Julius A

    2015-09-01

    Both medial and anterolateral plate applications have been described for the treatment of distal tibia fractures, each with distinct advantages and disadvantages. The objective of this study was to compare the biomechanical properties of medial and anterolateral plating constructs used to stabilize simulated varus and valgus fracture patterns of the distal tibia. In 16 synthetic tibia models, a 45° oblique cut was made to model an Orthopedic Trauma Association type 43-A1.2 distal tibia fracture in either a varus or valgus injury pattern. Each fracture was then reduced and plated with a precontoured medial or anterolateral distal tibia plate. The specimens were biomechanically tested in axial and torsional loading, cyclic axial loading, and load to failure. For the varus fracture pattern, medial plating showed less fracture site displacement and rotation and was stiffer in both axial and torsional loading (P<.05). For the valgus fracture pattern, there was no statistically significant difference between medial and anterolateral plating. There were no significant differences between the 2 constructs for either fracture pattern with respect to ultimate load, displacement, or energy absorption in load to failure testing. When used to stabilize varus fracture patterns, medial plates showed superior biomechanical performance compared with anterolateral plates. In this application, the medial plates functioned in anti-glide mode. For valgus fracture patterns, no biomechanical differences between anterolateral and medial plating were observed. In clinical practice, surgeons should take this biomechanical evidence into account when devising a treatment strategy for fixation of distal tibia fractures.

  15. A case report on a full-thickness chest wall reconstruction with polypropylene mesh and stainless steel mesh concurrently using a transverse rectus abdominis myocutaneous flap.

    PubMed

    Yoshino, Naoyuki; Yamauchi, Shigeo; Akimoto, Masataka; Hisayoshi, Takao; Koizumi, Kiyoshi; Shimizu, Kazuo

    2006-12-01

    A full-thickness chest wall resection requires subsequent chest wall reconstruction. A chest wall resection and reconstruction was performed using a transverse rectus abdominis myocutaneous (TRAM) flap, together with polypropylene mesh (Marlex mesh) and stainless steel mesh (SSM). A 71-year-old man was diagnosed as having recurrent lung cancer in the chest wall, and underwent surgical resection. Marlex mesh was sutured to the posterior wall of the surgical defect. A portion of the SSM was adjusted to the size of the defect and cut out. Its edges were folded to make the portion into a plate. This SSM plate was placed anteriorly to the Marlex mesh and sutured to the ribs. The Marlex mesh was folded back on the SSM plate by 2 cm and fixed. After the above procedures, a left-sided TRAM flap was raised through a subcutaneous tunnel up to the defect and sutured to the region. The patient was discharged from hospital 19 days postoperatively. The wound was fine and he had no flail chest or dyspnea, and carcinomatous pain resolved.

  16. A case of central carcinoma of the mandible arising from a recurrent odontogenic keratocyst: delineation of surgical margins and reconstruction with bilateral rectus abdominis myocutaneous free flaps.

    PubMed

    Ota, Y; Karakida, K; Watanabe, D; Miyasaka, M; Tsukinoki, K

    1998-10-01

    A case of central carcinoma of the mandible arising from a recurrent odontogenic keratocyst is reported. A 38-year-old man was admitted to the Tokai University Hospital due to postoperative infection of a recurrent odontogenic keratocyst of the left mandible. He had had a cystectomy for an odontogenic keratocyst 4 years ago. The lesion revealed bony destruction of the mandible with worm-eating shaped margins with extension to the facial skin. A biopsy specimen revealed squamous cell carcinoma. The mandible was resected with facial skin and the sublingual space was dissected to preserve the lingual nerve. The oral and the facial resections were reconstructed with a titanium plate and bilateral rectus abdominis myocutaneous free flaps. The plate was removed due to infection around the margins and readjustment of the flaps was conducted 5 months after the surgery. He has not had a local relapse, metastasis, or incisional hernia for 8 months following surgery. Good occlusion has been attained by the residual mandible, and he is able to eat without any problems.

  17. The properties of the extraocular muscles of the frog. II. Pharmacological properties of the isolated superior oblique and superior rectus muscles.

    PubMed

    Asmussen, G

    1978-01-01

    The pharmacological properties of the superior oblique and the superior rectus muscles of the frog's eye were investigated in comparison with those of a skeletal muscle (iliofibularis muscle) of the same animal. Acetylcholine causes sustained contractures of the extraocular muscles; this effect is increased by physostigmine and decreased or abolished by d-tubocurarine. Also the applications of succinylcholine, choline or caffeine are able to evoke contractures. There are no striking differences in pharmacological properties between extraocular and skeletal muscles of the frog. The time-course of the contractures and the sensitivity of the muscle preparations to the drugs which evoke contractures are identical in extraocular and iliofibularis muscles. In comparison with skeletal muscles there is no higher sensitivity of the extraocular muscles against curare-like drugs. The existence of adrenergic receptors could not be found neither in extraocular nor in skeletal muscles of the frog. It is concluded that in frogs no pharmacological differences exist between the muscle fibre types which compose the extraocular and the skeletal muscles.

  18. Pixelation Effects in Weak Lensing

    NASA Technical Reports Server (NTRS)

    High, F. William; Rhodes, Jason; Massey, Richard; Ellis, Richard

    2007-01-01

    Weak gravitational lensing can be used to investigate both dark matter and dark energy but requires accurate measurements of the shapes of faint, distant galaxies. Such measurements are hindered by the finite resolution and pixel scale of digital cameras. We investigate the optimum choice of pixel scale for a space-based mission, using the engineering model and survey strategy of the proposed Supernova Acceleration Probe as a baseline. We do this by simulating realistic astronomical images containing a known input shear signal and then attempting to recover the signal using the Rhodes, Refregier, and Groth algorithm. We find that the quality of shear measurement is always improved by smaller pixels. However, in practice, telescopes are usually limited to a finite number of pixels and operational life span, so the total area of a survey increases with pixel size. We therefore fix the survey lifetime and the number of pixels in the focal plane while varying the pixel scale, thereby effectively varying the survey size. In a pure trade-off for image resolution versus survey area, we find that measurements of the matter power spectrum would have minimum statistical error with a pixel scale of 0.09' for a 0.14' FWHM point-spread function (PSF). The pixel scale could be increased to 0.16' if images dithered by exactly half-pixel offsets were always available. Some of our results do depend on our adopted shape measurement method and should be regarded as an upper limit: future pipelines may require smaller pixels to overcome systematic floors not yet accessible, and, in certain circumstances, measuring the shape of the PSF might be more difficult than those of galaxies. However, the relative trends in our analysis are robust, especially those of the surface density of resolved galaxies. Our approach thus provides a snapshot of potential in available technology, and a practical counterpart to analytic studies of pixelation, which necessarily assume an idealized shape

  19. Reverse Evans peroneus brevis medial ankle stabilization for balancing valgus ankle contracture during total ankle replacement.

    PubMed

    Roukis, Thomas S; Prissel, Mark A

    2014-01-01

    Medial ankle instability secondary to deltoid ligament insufficiency is frequently encountered when performing total ankle replacement and remains a challenge. In the present techniques report, we describe a "reverse" Evans peroneus brevis tendon nonanatomic deltoid ligament reconstruction for medial ankle stabilization harvested through limited incisions using simple topographic anatomic landmarks. The harvested peroneus brevis tendon is brought through a drill hole in the talus from laterally to medially, aiming for the junction of the talar neck and body plantar to the midline. The tendon is the brought superiorly and obliquely to the anterior medial aspect of the distal tibia where it is secured under a plate and screw construct. This modified Evans peroneus brevis tendon nonanatomic deltoid ligament reconstruction is useful in providing medial ankle stability during or after primary and revision total ankle replacement.

  20. The medial septum acts through the medial preoptic area for thermoregulation and works with it for sleep regulation.

    PubMed

    Srividya, Rajagopalan; Mallick, Hruda Nanda; Kumar, Velayudhan Mohan

    2007-01-01

    The chronic changes in sleep-wakefulness (S-W), body temperature (Tb), locomotor activity (LMA) and thermal preference were studied in male Wistar rats after the destruction of neurons in both the medial preoptic area (mPOA) and the medial septum (MS) by intracerebral injection of N-methyl-D-aspartic acid. An increase in the Tb, and a preference for higher ambient temperature (Tamb) of 30 degrees C were observed after the combined lesion of the mPOA and the MS. Similar changes were reported to occur after the lesion that was restricted to the mPOA. But these alterations were in contrast to the decrease in Tb and preference for lower Tamb, observed after the MS lesion. The thermostat of the brain would have been reset at a higher level after the combined lesion, as there was an increase in Tb, along with a preference for a higher Tamb, and an increase in LMA. There was a reduction in the frequency and the duration of the slow wave sleep (SWS) episodes, and a reduction in the frequency of the paradoxical sleep (PS) episodes after the combined lesion. The destruction of the MS neurons was probably responsible for the reduction in the frequency of SWS, whereas the loss of mPOA neurons was responsible for the decrease in the duration of SWS and frequency of PS. It can be suggested that the MS exerts its influence on thermoregulation through the mPOA. However, the MS and the mPOA seem to play independent, but complementary roles in sleep promotion.

  1. Connections of the medial telencephalic wall in the spotted African Lungfish.

    PubMed

    Northcutt, R Glenn; Westhoff, Guido

    2011-01-01

    The extent and boundaries of the roof, or pallium, of the telencephalon in lungfishes have been debated for over 30 years, and two hypotheses exist. Proponents of a restricted pallium claim that the medial border of the pallium occurs in a dorsal position and that the entire medial hemispheric wall is formed by the septal nuclei. Proponents of an extended pallium claim that the medial border of the pallium occurs in a more ventral position and that the medial hemispheric wall is divided into a dorsal medial pallium and ventral septal nuclei, as in amphibians. Immunohistochemical data have generally been interpreted to support the hypothesis of an extended pallium, but disagreement still exists. To clarify the extent of the pallium in lungfishes, the connections of the dorsal and ventral divisions of the medial hemispheric wall in the Spotted African Lungfish were examined using a number of neuronal tracers. In amphibians and other tetrapods, the afferent projections to the medial pallium and the septal nuclei differ extensively, as do the commissural routes taken by decussating interhemispheric connections. Although the descending projections of the medial pallium and septal nuclei are very similar to one another in amphibians and other tetrapods, they do differ in that the septal nuclei and the ventral thalamus are extensively interlinked, whereas the medial pallium lacks such connections. These differences also characterize the connections of the dorsal and ventral divisions of the medial hemispheric wall in the Spotted African Lungfish, which supports the hypothesis of an extended pallium. The telencephalic organization in lungfishes thus appears remarkably similar to that in amphibians and reflects a pattern that almost certainly existed in the last common ancestor of lungfishes and tetrapods.

  2. Transcaruncular Approach for Treatment of Medial Wall and Large Orbital Blowout Fractures

    PubMed Central

    Nguyen, Dennis C.; Shahzad, Farooq; Snyder-Warwick, Alison; Patel, Kamlesh B.; Woo, Albert S.

    2015-01-01

    We evaluate the safety and efficacy of the transcaruncular approach for reconstruction of medial orbital wall fractures and the combined transcaruncular–transconjunctival approach for reconstruction of large orbital defects involving the medial wall and floor. A retrospective review of the clinical and radiographic data of patients who underwent either a transcaruncular or a combined transcaruncular–transconjunctival approach by a single surgeon for orbital fractures between June 2007 and June 2013 was undertaken. Seven patients with isolated medial wall fractures underwent a transcaruncular approach, and nine patients with combined medial wall and floor fractures underwent a transcaruncular–transconjunctival approach with a lateral canthotomy. Reconstruction was performed using a porous polyethylene implant. All patients with isolated medial wall fractures presented with enophthalmos. In the combined medial wall and floor group, five out of eight patients had enophthalmos with two also demonstrating hypoglobus. The size of the medial wall defect on preoperative computed tomography (CT) scan ranged from 2.6 to 4.6 cm2; the defect size of combined medial wall and floor fractures was 4.5 to 12.7 cm2. Of the 11 patients in whom postoperative CT scans were obtained, all were noted to have acceptable placement of the implant. All patients had correction of enophthalmos and hypoglobus. One complication was noted, with a retrobulbar hematoma having developed 2 days postoperatively. The transcaruncular approach is a safe and effective method for reconstruction of medial orbital floor fractures. Even large fractures involving the orbital medial wall and floor can be adequately exposed and reconstructed with a combined transcaruncular–transconjunctival-lateral canthotomy approach. The level of evidence of this study is IV (case series with pre/posttest). PMID:26889348

  3. Classical field approach to quantum weak measurements.

    PubMed

    Dressel, Justin; Bliokh, Konstantin Y; Nori, Franco

    2014-03-21

    By generalizing the quantum weak measurement protocol to the case of quantum fields, we show that weak measurements probe an effective classical background field that describes the average field configuration in the spacetime region between pre- and postselection boundary conditions. The classical field is itself a weak value of the corresponding quantum field operator and satisfies equations of motion that extremize an effective action. Weak measurements perturb this effective action, producing measurable changes to the classical field dynamics. As such, weakly measured effects always correspond to an effective classical field. This general result explains why these effects appear to be robust for pre- and postselected ensembles, and why they can also be measured using classical field techniques that are not weak for individual excitations of the field.

  4. Pyramidal and stellate cell specificity of grid and border representations in layer 2 of medial entorhinal cortex.

    PubMed

    Tang, Qiusong; Burgalossi, Andrea; Ebbesen, Christian Laut; Ray, Saikat; Naumann, Robert; Schmidt, Helene; Spicher, Dominik; Brecht, Michael

    2014-12-17

    In medial entorhinal cortex, layer 2 principal cells divide into pyramidal neurons (mostly calbindin positive) and dentate gyrus-projecting stellate cells (mostly calbindin negative). We juxtacellularly labeled layer 2 neurons in freely moving animals, but small sample size prevented establishing unequivocal structure-function relationships. We show, however, that spike locking to theta oscillations allows assigning unidentified extracellular recordings to pyramidal and stellate cells with ∼83% and ∼89% specificity, respectively. In pooled anatomically identified and theta-locking-assigned recordings, nonspatial discharges dominated, and weakly hexagonal spatial discharges and head-direction selectivity were observed in both cell types. Clear grid discharges were rare and mostly classified as pyramids (19%, 19/99 putative pyramids versus 3%, 3/94 putative stellates). Most border cells were classified as stellate (11%, 10/94 putative stellates versus 1%, 1/99 putative pyramids). Our data suggest weakly theta-locked stellate border cells provide spatial input to dentate gyrus, whereas strongly theta-locked grid discharges occur mainly in hexagonally arranged pyramidal cell patches and do not feed into dentate gyrus.

  5. Weak gravitational lensing by galaxies

    SciTech Connect

    Brainerd, T.G. |; Blandford, R.D.; Smail, I. |

    1996-08-01

    We report a detection of weak, tangential distortion of the images of cosmologically distant, faint galaxies due to gravitational lensing by foreground galaxies. A mean image polarization of ({ital p})=0.011{plus_minus}0.006 (95{percent} confidence bounds) is obtained for 3202 pairs of source (23{lt}{ital r}{sub {ital s}}{le}24) and lens (20{le}{ital r}{sub {ital d}}{le}23) galaxies with projected separations of 5{double_prime}{le}{theta}{le}34{double_prime}. Averaged over annuli of inner radius 5{double_prime} and outer radius {theta}{sub max}, the signal is string for lens-source separations of {theta}{sub max}{approx_lt}90{double_prime} consistent with quasi-isothermal galaxy halos extending to large radii ({approx_gt}100{ital h}{sup {minus}1} kpc). The observed polarization is also consistent with the signal expected on the basis of simulations incorporating measured properties of local galaxies and modest extrapolations of the observed redshift distribution of faint galaxies (to which the results are somewhat sensitive). From the simulations we obtain formal best-fit model parameters for the dark halos of the lens galaxies that consist of a characteristic circular velocity of {ital V}{asterisk}{approximately}220{plus_minus}80 kms{sup {minus}1} and characteristic radial extent of {ital s}{asterisk}{approx_gt}100{ital h}{sup {minus}1} kpc. The predicted polarization based on the model is relatively insensitive to the characteristic radial extent of the halos, {ital s}{asterisk}, and very small halos ({ital s}{asterisk}{approximately}10{ital h}{sup {minus}1} kpc) are excluded only at the 2 {sigma} level. The formal best-fit halo parameters imply typical masses for the lens galaxies within a radius of 100{ital h}{sup -1} kpc on the order of 1.0{sup +1.2}{sub {minus}0.5}{times}10{sup 12} {ital h}{sup {minus}1}{ital M}{sub {circle_dot}} (90% confidence bounds), in agreement with recent dynamical estimates of the masses of local spiral galaxies.

  6. Spin effects in the weak interaction

    SciTech Connect

    Freedman, S.J. Chicago Univ., IL . Dept. of Physics Chicago Univ., IL . Enrico Fermi Inst.)

    1990-01-01

    Modern experiments investigating the beta decay of the neutron and light nuclei are still providing important constraints on the theory of the weak interaction. Beta decay experiments are yielding more precise values for allowed and induced weak coupling constants and putting constraints on possible extensions to the standard electroweak model. Here we emphasize the implications of recent experiments to pin down the strengths of the weak vector and axial vector couplings of the nucleon.

  7. Expression of mu opioid receptor in dorsal diencephalic conduction system: new insights for the medial habenula.

    PubMed

    Gardon, O; Faget, L; Chu Sin Chung, P; Matifas, A; Massotte, D; Kieffer, B L

    2014-09-26

    The habenular complex, encompassing medial (MHb) and lateral (LHb) divisions, is a highly conserved epithalamic structure involved in the dorsal diencephalic conduction system (DDC). These brain nuclei regulate information flow between the limbic forebrain and the mid- and hindbrain, integrating cognitive with emotional and sensory processes. The MHb is also one of the strongest expression sites for mu opioid receptors (MORs), which mediate analgesic and rewarding properties of opiates. At present however, anatomical distribution and function of these receptors have been poorly studied in MHb pathways. Here we took advantage of a newly generated MOR-mcherry knock-in mouse line to characterize MOR expression sites in the DDC. MOR-mcherry fluorescent signal is weak in the LHb, but strong expression is visible in the MHb, fasciculus retroflexus (fr) and interpeduncular nucleus (IPN), indicating that MOR is mainly present in the MHb-IPN pathway. MOR-mcherry cell bodies are detected both in basolateral and apical parts of MHb, where the receptor co-localizes with cholinergic and substance P (SP) neurons, respectively, representing two main MHb neuronal populations. MOR-mcherry is expressed in most MHb-SP neurons, and is present in only a subpopulation of MHb-cholinergic neurons. Intense diffuse fluorescence detected in lateral and rostral parts of the IPN further suggests that MOR-mcherry is transported to terminals of these SP and cholinergic neurons. Finally, MOR-mcherry is present in septal regions projecting to the MHb, and in neurons of the central and intermediate IPN. Together, this study describes MOR expression in several compartments of the MHb-IPN circuitry. The remarkably high MOR density in the MHb-IPN pathway suggests that these receptors are in a unique position to mediate analgesic, autonomic and reward responses.

  8. Catecholaminergic depletion within the prelimbic medial prefrontal cortex enhances latent inhibition.

    PubMed

    Nelson, A J D; Thur, K E; Marsden, C A; Cassaday, H J

    2010-09-29

    Latent inhibition (LI) refers to the reduction in conditioning to a stimulus that has received repeated non-reinforced pre-exposure. Investigations into the neural substrates of LI have focused on the nucleus accumbens (NAc) and its inputs from the hippocampal formation and adjacent cortical areas. Previous work has suggested that lesions to the medial prefrontal cortex (mPFC), another major source of input to the NAc, do not disrupt LI. However, a failure to observe disrupted LI does not preclude the possibility that a particular brain region is involved in the expression of LI. Moreover, the mPFC is a heterogeneous structure and there has been no investigation of a possible role of different regions within the mPFC in regulating LI under conditions that prevent LI in controls. Here, we tested whether 6-hydroxydopamine (6-OHDA)-induced lesions of dopamine (DA) terminals within the prelimbic (PL) and infralimbic (IL) mPFC would lead to the emergence of LI under conditions that do produce LI in controls (weak pre-exposure). LI was measured in a thirst motivated conditioned emotional response procedure with 10 pre-exposures to a noise conditioned stimulus (CS) and two conditioning trials. Sham-operated and IL-lesioned animals did not show LI and conditioned to the pre-exposed CS at comparable levels to the non-pre-exposed controls. 6-OHDA lesions to the PL, however, produced potentiation of LI. These results provide the first demonstration that the PL mPFC is a component of the neural circuitry underpinning LI.

  9. Catecholaminergic depletion within the prelimbic medial prefrontal cortex enhances latent inhibition

    PubMed Central

    Nelson, A.J.D.; Thur, K.E.; Marsden, C.A.; Cassaday, H.J.

    2010-01-01

    Latent inhibition (LI) refers to the reduction in conditioning to a stimulus that has received repeated non-reinforced pre-exposure. Investigations into the neural substrates of LI have focused on the nucleus accumbens (NAc) and its inputs from the hippocampal formation and adjacent cortical areas. Previous work has suggested that lesions to the medial prefrontal cortex (mPFC), another major source of input to the NAc, do not disrupt LI. However, a failure to observe disrupted LI does not preclude the possibility that a particular brain region is involved in the expression of LI. Moreover, the mPFC is a heterogeneous structure and there has been no investigation of a possible role of different regions within the mPFC in regulating LI under conditions that prevent LI in controls. Here, we tested whether 6-hydroxydopamine (6-OHDA)-induced lesions of dopamine (DA) terminals within the prelimbic (PL) and infralimbic (IL) mPFC would lead to the emergence of LI under conditions that do produce LI in controls (weak pre-exposure). LI was measured in a thirst motivated conditioned emotional response procedure with 10 pre-exposures to a noise conditioned stimulus (CS) and two conditioning trials. Sham-operated and IL-lesioned animals did not show LI and conditioned to the pre-exposed CS at comparable levels to the non-pre-exposed controls. 6-OHDA lesions to the PL, however, produced potentiation of LI. These results provide the first demonstration that the PL mPFC is a component of the neural circuitry underpinning LI. PMID:20619321

  10. Weak point target detection in star sensor

    NASA Astrophysics Data System (ADS)

    Liu, Da; Xiong, Yazhou; Li, Yi; Wang, Li; Li, Chunyan; Yin, Fang

    2016-11-01

    Space weak point targets detection is very useful in non cooperative target detection. Influenced by the chip noise and space environmental noise, weak point targets detection becomes a difficulty. In the paper, firstly the star is extracted from the picture, the background picture is filtered to reduce the noise, and then the moving distance between adjacent pictures is calculated, after picture overlapping between adjacent pictures, the energy of the weak point target is improved, with a appropriate threshold, the weak point target is extracted. The proposed method can be widely utilized in space exploration, space defense etc.

  11. Weak measurements and nonClassical correlations

    NASA Astrophysics Data System (ADS)

    Lekshmi, S.; Shaji, N.; Shaji, Anil

    2017-01-01

    We extend the definition of quantum discord as a quantifier of nonClassical correlations in a quantum state to the case where weak measurements are performed on subsystem A of a bipartite system AB. The properties of weak discord are explored for several families of quantum states. We find that in many cases weak quantum discord is identical to normal discord and in general the values of the two are very close to each other. Weak quantum discord reduces to discord in the appropriate limits as well. We also discuss the implications of these observations on the interpretations of quantum discord.

  12. Effects of different medial arch support heights on rearfoot kinematics

    PubMed Central

    Mayer, Frank; Baur, Heiner

    2017-01-01

    Background Foot orthoses are usually assumed to be effective by optimizing mechanically dynamic rearfoot configuration. However, the effect from a foot orthosis on kinematics that has been demonstrated scientifically has only been marginal. The aim of this study was to examine the effect of different heights in medial arch-supported foot orthoses on rear foot motion during gait. Methods Nineteen asymptomatic runners (36±11years, 180±5cm, 79±10kg; 41±22km/week) participated in the study. Trials were recorded at 3.1 mph (5 km/h) on a treadmill. Athletes walked barefoot and with 4 different not customized medial arch-supported foot orthoses of various arch heights (N:0 mm, M:30 mm, H:35 mm, E:40mm). Six infrared cameras and the `Oxford Foot Model´ were used to capture motion. The average stride in each condition was calculated from 50 gait cycles per condition. Eversion excursion and internal tibia rotation were analyzed. Descriptive statistics included calculating the mean ± SD and 95% CIs. Group differences by condition were analyzed by one factor (foot orthoses) repeated measures ANOVA (α = 0.05). Results Eversion excursion revealed the lowest values for N and highest for H (B:4.6°±2.2°; 95% CI [3.1;6.2]/N:4.0°±1.7°; [2.9;5.2]/M:5.2°±2.6°; [3.6;6.8]/H:6.2°±3.3°; [4.0;8.5]/E:5.1°±3.5°; [2.8;7.5]) (p>0.05). Range of internal tibia rotation was lowest with orthosis H and highest with E (B:13.3°±3.2°; 95% CI [11.0;15.6]/N:14.5°±7.2°; [9.2;19.6]/M:13.8°±5.0°; [10.8;16.8]/H:12.3°±4.3°; [9.0;15.6]/E:14.9°±5.0°; [11.5;18.3]) (p>0.05). Differences between conditions were small and the intrasubject variation high. Conclusion Our results indicate that different arch support heights have no systematic effect on eversion excursion or the range of internal tibia rotation and therefore might not exert a crucial influence on rear foot alignment during gait. PMID:28257426

  13. The Medial Orbitofrontal Cortex Regulates Sensitivity to Outcome Value

    PubMed Central

    Zimmermann, Kelsey S.; Allen, Amanda G.; Taylor, Jane R.

    2016-01-01

    An essential component of goal-directed decision-making is the ability to maintain flexible responding based on the value of a given reward, or “reinforcer.” The medial orbitofrontal cortex (mOFC), a subregion of the ventromedial prefrontal cortex, is uniquely positioned to regulate this process. We trained mice to nose poke for food reinforcers and then stimulated this region using CaMKII-driven Gs-coupled designer receptors exclusively activated by designer drugs (DREADDs). In other mice, we silenced the neuroplasticity-associated neurotrophin brain-derived neurotrophic factor (BDNF). Activation of Gs-DREADDs increased behavioral sensitivity to reinforcer devaluation, whereas Bdnf knockdown blocked sensitivity. These changes were accompanied by modifications in breakpoint ratios in a progressive ratio task, and they were recapitulated in Bdnf+/− mice. Replacement of BDNF selectively in the mOFC in Bdnf+/− mice rescued behavioral deficiencies, as well as phosphorylation of extracellular-signal regulated kinase 1/2 (ERK1/2). Thus, BDNF expression in the mOFC is both necessary and sufficient for the expression of typical effort allocation relative to an anticipated reinforcer. Additional experiments indicated that expression of the immediate-early gene c-fos was aberrantly elevated in the Bdnf+/− dorsal striatum, and BDNF replacement in the mOFC normalized expression. Also, systemic administration of an MAP kinase kinase inhibitor increased breakpoint ratios, whereas the addition of discrete cues bridging the response–outcome contingency rescued breakpoints in Bdnf+/− mice. We argue that BDNF–ERK1/2 in the mOFC is a key regulator of “online” goal-directed action selection. SIGNIFICANCE STATEMENT Goal-directed response selection often involves predicting the consequences of one's actions and the value of potential payoffs. Lesions or chemogenetic inactivation of the medial orbitofrontal cortex (mOFC) in rats induces failures in retrieving outcome

  14. Location and tension of the medial palpebral ligament.

    PubMed

    Hwang, Kun; Huan, Fan; Nam, Yong Seok; Han, Seung Ho; Kim, Dae Joong

    2013-11-01

    The aim of this study was to elucidate the precise anatomic location and tension of the medial palpebral ligament (MPL). Eleven hemifaces of 10 fresh Korean adult cadavers were used in this study. Nine specimens were used for measurement of dissection and tension, and 2 were used for histologic study. Measurements of tensile strength of each part of the MPL and Horner muscle were performed using a force gauge.The MPL consisted of 2 layers in all specimens dissected. The superficial layer of the palpebral ligament (SMPL) was observed from the anterior lacrimal crest to the upper and lower tarsal plates. The deep layer of the palpebral ligament (DMPL) lay from the anterior lacrimal crest to the posterior lacrimal crest, covering the lacrimal sac. The Horner muscle was observed at the posterior lacrimal crest just lateral to the attachment of the DMPL and ran laterally to the tarsal plate deep to the SMPL. The SMPL began at 4.5 ± 2.3 mm lateral to the nasomaxillary suture line to the upper and lower tarsal plates. Its transverse length was 9.6 ± 1.5 mm, and vertical width was 2.4 ± 0.7 mm, and its thickness was 4.5 ± 2.3 mm. The transverse length of the DMPL was 3.7 ± 0.4 mm, and its vertical width was 2.9 ± 1.3 mm, with a thickness of 0.3 ± 0.1 mm. The transverse length of the Horner muscle was 7.6 ± 1.9 mm, and its vertical width was 4.06 ± 1.5 mm, with a thickness of 0.4 ± 0.1 mm. The tensile strength of the SMPL was 13.4 ± 3.2 N, that of the DMPL was 4.1 ± 1.7 N, and that for Horner muscle was 9.0 ± 3.1 N. The tensile strength of the SMPL was significantly higher than that of the DMPL (P = 0.003).We reconfirmed that the MPL consisted of 2 layers: superficial layer and deep layer. Our results might be of use in surgeries of the medial canthi.

  15. Editorial Commentary: Chondrocytes Trump Ligaments! Partial Release of the Medial Collateral Ligament During Knee Arthroscopy Protects Chondrocytes.

    PubMed

    Leland, J Martin

    2016-10-01

    With knee arthroscopy being the most common orthopaedic procedure performed in the United States, it is crucial to be able to access the entire knee without iatrogenic injury. Frequently orthopaedic surgeons encounter tight medial compartments, creating difficulty in accessing the posterior horn of the medial meniscus without damaging the articular cartilage. Partial release of the medial collateral ligament during knee arthroscopy protects chondrocytes.

  16. The effects of thermal capsulorrhaphy of medial parapatellar capsule on patellar lateral displacement

    PubMed Central

    Zheng, Naiquan; Davis, Brent R; Andrews, James R

    2008-01-01

    Background The effectiveness of thermal shrinkage on the medial parapatellar capsule for treating recurrent patellar dislocation is controversial. One of reasons why it is still controversial is that the effectiveness is still qualitatively measured. The purpose of this study was to quantitatively determine the immediate effectiveness of the medial parapatellar capsule shrinkage as in clinical setting. Methods Nine cadaveric knees were used to collect lateral displacement data before and after medial shrinkage or open surgery. The force and displacement were recorded while a physician pressed the patella from the medial side to mimic the physical exam used in clinic. Ten healthy subjects were used to test the feasibility of the technique on patients and establish normal range of lateral displacement of the patella under a medial force. The force applied, the resulting displacement and the ratio of force over displacement were compared among four data groups (normal knees, cadaveric knees before medial shrinkage, after shrinkage and after open surgery). Results Displacements of the cadaveric knees both before and after thermal modification were similar to normal subjects, and the applied forces were significantly higher. No significant differences were found between before and after thermal modification groups. After open surgery, displacements were reduced significantly while applied forces were significantly higher. Conclusion No immediate difference was found after thermal shrinkage of the medial parapatellar capsule. Open surgery immediately improved of the lateral stiffness of the knee capsule. PMID:18826583

  17. The effect of different types of insoles or shoe modifications on medial loading of the knee in persons with medial knee osteoarthritis: a randomised trial

    PubMed Central

    Chapman, Graham J.; Parkes, Matthew J.; Forsythe, Laura.; Felson, David T.

    2015-01-01

    ABSTRACT Many conservative treatments exist for medial knee osteoarthritis (OA) which aims to reduce the external knee adduction moment (EKAM). The objective of this study was to determine the difference between different shoes and lateral wedge insoles on EKAM, knee adduction angular impulse (KAAI), external knee flexion moment, pain, and comfort when walking in individuals with medial knee OA. Seventy individuals with medial knee OA underwent three‐dimensional walking gait analysis in five conditions (barefoot, control shoe, typical wedge, supported wedge, and mobility shoe) with pain and comfort recorded concurrently. The change in EKAM, KAAI, external knee flexion moment, pain, and comfort were assessed using multiple linear regressions and pairwise comparisons. Compared with the control shoe, lateral wedge insoles and barefoot walking significantly reduced early stance EKAM and KAAI. The mobility shoe showed no effect. A significant reduction in latter stance EKAM was seen in the lateral wedge insoles compared to the other conditions, with only the barefoot condition reducing the external knee flexion moment. However, the mobility shoe showed significant immediate knee pain reduction and improved comfort scores. Different lateral wedge insoles show comparable reductions in medial knee loading and in our study, the mobility shoe did not affect medial loading. © 2015 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. J Orthop Res 33:1646–1654, 2015. PMID:25991385

  18. The effect of different types of insoles or shoe modifications on medial loading of the knee in persons with medial knee osteoarthritis: a randomised trial.

    PubMed

    Jones, Richard K; Chapman, Graham J; Parkes, Matthew J; Forsythe, Laura; Felson, David T

    2015-11-01

    Many conservative treatments exist for medial knee osteoarthritis (OA) which aims to reduce the external knee adduction moment (EKAM). The objective of this study was to determine the difference between different shoes and lateral wedge insoles on EKAM, knee adduction angular impulse (KAAI), external knee flexion moment, pain, and comfort when walking in individuals with medial knee OA. Seventy individuals with medial knee OA underwent three-dimensional walking gait analysis in five conditions (barefoot, control shoe, typical wedge, supported wedge, and mobility shoe) with pain and comfort recorded concurrently. The change in EKAM, KAAI, external knee flexion moment, pain, and comfort were assessed using multiple linear regressions and pairwise comparisons. Compared with the control shoe, lateral wedge insoles and barefoot walking significantly reduced early stance EKAM and KAAI. The mobility shoe showed no effect. A significant reduction in latter stance EKAM was seen in the lateral wedge insoles compared to the other conditions, with only the barefoot condition reducing the external knee flexion moment. However, the mobility shoe showed significant immediate knee pain reduction and improved comfort scores. Different lateral wedge insoles show comparable reductions in medial knee loading and in our study, the mobility shoe did not affect medial loading.

  19. Correlation between the knee adduction torque and medial contact force for a variety of gait patterns.

    PubMed

    Zhao, Dong; Banks, Scott A; Mitchell, Kim H; D'Lima, Darryl D; Colwell, Clifford W; Fregly, Benjamin J

    2007-06-01

    The external knee adduction torque has been proposed as a surrogate measure for medial compartment load during gait. However, a direct link between these two quantities has not been demonstrated using in vivo measurement of medial compartment load. This study uses in vivo data collected from a single subject with an instrumented knee implant to evaluate this link. The subject performed five different overground gait motions (normal, fast, slow, wide, and toe-out) with simultaneous collection of instrumented implant, video motion, and ground reaction data. For each trial, the knee adduction torque was measured externally while the total axial force applied to the tibial insert was measured internally. Based on data collected from the same subject performing treadmill gait under fluoroscopic motion analysis, a regression equation was developed to calculate medial contact force from the implant load cell measurements. Correlation analyses were performed for the stance phase and entire gait cycle to quantify the relationship between the knee adduction torque and both the medial contact force and the medial to total contact force ratio. When the entire gait cycle was analyzed, R(2) for medial contact force was 0.77 when all gait trials were analyzed together and between 0.69 and 0.93 when each gait trial was analyzed separately (p < 0.001 in all cases). For medial to total force ratio, R(2) was 0.69 for all trials together and between 0.54 and 0.90 for each trial separately (p < 0.001 in all cases). When only the stance phase was analyzed, R(2) values were slightly lower. These results support the hypothesis that the knee adduction torque is highly correlated with medial compartment contact force and medial to total force ratio during gait.

  20. The Role of Medial Frontal Cortex in Action Anticipation in Professional Badminton Players

    PubMed Central

    Xu, Huan; Wang, Pin; Ye, Zhuo’er; Di, Xin; Xu, Guiping; Mo, Lei; Lin, Huiyan; Rao, Hengyi; Jin, Hua

    2016-01-01

    Some studies show that the medial frontal cortex is associated with more skilled action anticipation, while similar findings are not observed in some other studies, possibly due to the stimuli employed and the participants used as the control group. In addition, no studies have investigated whether there is any functional connectivity between the medial frontal cortex and other brain regions in more skilled action anticipation. Therefore, the present study aimed to re-investigate how the medial frontal cortex is involved in more skilled action anticipation by circumventing the limitations of previous research and to investigate that the medial frontal cortex functionally connected with other brain regions involved in action processing in more skilled action anticipation. To this end, professional badminton players and novices were asked to anticipate the landing position of the shuttlecock while watching badminton match videos or to judge the gender of the players in the matches. The video clips ended right at the point that the shuttlecock and the racket came into contact to reduce the effect of information about the trajectory of the shuttlecock. Novices who lacked training and watching experience were recruited for the control group to reduce the effect of sport-related experience on the medial frontal cortex. Blood oxygenation level-dependent activation was assessed by means of functional magnetic resonance imaging. Compared to novices, badminton players exhibited stronger activation in the left medial frontal cortex during action anticipation and greater functional connectivity between left medial frontal cortex and some other brain regions (e.g., right posterior cingulate cortex). Therefore, the present study supports the position that the medial frontal cortex plays a role in more skilled action anticipation and that there is a specific brain network for more skilled action anticipation that involves right posterior cingulate cortex, right fusiform gyrus

  1. The Necessity of the Medial Temporal Lobe for Statistical Learning

    PubMed Central

    Schapiro, Anna C.; Gregory, Emma; Landau, Barbara; McCloskey, Michael; Turk-Browne, Nicholas B.

    2014-01-01

    The sensory input that we experience is highly patterned, and we are experts at detecting these regularities. Although the extraction of such regularities, or statistical learning (SL), is typically viewed as a cortical process, recent studies have implicated the medial temporal lobe (MTL), including the hippocampus. These studies have employed fMRI, leaving open the possibility that the MTL is involved but not necessary for SL. Here, we examined this issue in a case study of LSJ, a patient with complete bilateral hippocampal loss and broader MTL damage. In Experiments 1 and 2, LSJ and matched control participants were passively exposed to a continuous sequence of shapes, syllables, scenes, or tones containing temporal regularities in the co-occurrence of items. In a subsequent test phase, the control groups exhibited reliable SL in all conditions, successfully discriminating regularities from recombinations of the same items into novel foil sequences. LSJ, however, exhibited no SL, failing to discriminate regularities from foils. Experiment 3 ruled out more general explanations for this failure, such as inattention during exposure or difficulty following test instructions, by showing that LSJ could discriminate which individual items had been exposed. These findings provide converging support for the importance of the MTL in extracting temporal regularities. PMID:24456393

  2. Medial temporal lobe roles in human path integration.

    PubMed

    Yamamoto, Naohide; Philbeck, John W; Woods, Adam J; Gajewski, Daniel A; Arthur, Joeanna C; Potolicchio, Samuel J; Levy, Lucien; Caputy, Anthony J

    2014-01-01

    Path integration is a process in which observers derive their location by integrating self-motion signals along their locomotion trajectory. Although the medial temporal lobe (MTL) is thought to take part in path integration, the scope of its role for path integration remains unclear. To address this issue, we administered a variety of tasks involving path integration and other related processes to a group of neurosurgical patients whose MTL was unilaterally resected as therapy for epilepsy. These patients were unimpaired relative to neurologically intact controls in many tasks that required integration of various kinds of sensory self-motion information. However, the same patients (especially those who had lesions in the right hemisphere) walked farther than the controls when attempting to walk without vision to a previewed target. Importantly, this task was unique in our test battery in that it allowed participants to form a mental representation of the target location and anticipate their upcoming walking trajectory before they began moving. Thus, these results put forth a new idea that the role of MTL structures for human path integration may stem from their participation in predicting the consequences of one's locomotor actions. The strengths of this new theoretical viewpoint are discussed.

  3. Medial efferent mechanisms in children with auditory processing disorders.

    PubMed

    Mishra, Srikanta K

    2014-01-01

    Auditory processing disorder (APD) affects about 2-5% of children. However, the nature of this disorder is poorly understood. Children with APD typically have difficulties in complex listening situations. One mechanism thought to aid in listening-in-noise is the medial olivocochlear (MOC) inhibition. The purpose of this review was to critically analyze the published data on MOC inhibition in children with APD to determine whether the MOC efferents are involved in these individuals. The otoacoustic emission (OAE) methods used to assay MOC reflex were examined in the context of the current understanding of OAE generation mechanisms. Relevant literature suggests critical differences in the study population and OAE methods. Variables currently known to influence MOC reflex measurements, for example, middle-ear muscle reflexes or OAE signal-to-noise ratio, were not controlled in most studies. The use of potentially weaker OAE methods and the remarkable heterogeneity across studies does not allow for a definite conclusion whether or not the MOC reflex is altered in children with APD. Further carefully designed studies are needed to confirm the involvement of MOC efferents in APD. Knowledge of efferent functioning in children with APD would be mechanistically and clinically beneficial.

  4. The role of the medial prefrontal cortex in social categorization.

    PubMed

    Molenberghs, Pascal; Morrison, Samantha

    2014-03-01

    Group membership is an important aspect of our everyday behavior. Recently, we showed that existing relevant in-group labels increased activation in the medial prefrontal cortex (MPFC) compared with out-group labels, suggesting a role of the MPFC in social categorization. However, the question still remains whether this increase in MPFC activation for in-group representation is solely related with previous experience with the in-group. To test this, we randomly assigned participants to a red or blue team and in a subsequent functional magnetic resonance imaging experiment they categorized red and blue team words as belonging to either the in-group or the out-group. Results showed that even under these minimal conditions increased activation was found in the MPFC when participants indicated that they belonged to a group, as compared with when they did not. This effect was found to be associated with the level of group identification. These results confirm the role of MPFC in social categorization.

  5. Decoding Representations of Scenes in the Medial Temporal Lobes

    PubMed Central

    Bonnici, Heidi M; Kumaran, Dharshan; Chadwick, Martin J; Weiskopf, Nikolaus; Hassabis, Demis; Maguire, Eleanor A

    2012-01-01

    Recent theoretical perspectives have suggested that the function of the human hippocampus, like its rodent counterpart, may be best characterized in terms of its information processing capacities. In this study, we use a combination of high-resolution functional magnetic resonance imaging, multivariate pattern analysis, and a simple decision making task, to test specific hypotheses concerning the role of the medial temporal lobe (MTL) in scene processing. We observed that while information that enabled two highly similar scenes to be distinguished was widely distributed throughout the MTL, more distinct scene representations were present in the hippocampus, consistent with its role in performing pattern separation. As well as viewing the two similar scenes, during scanning participants also viewed morphed scenes that spanned a continuum between the original two scenes. We found that patterns of hippocampal activity during morph trials, even when perceptual inputs were held entirely constant (i.e., in 50% morph trials), showed a robust relationship with participants' choices in the decision task. Our findings provide evidence for a specific computational role for the hippocampus in sustaining detailed representations of complex scenes, and shed new light on how the information processing capacities of the hippocampus may influence the decision making process. © 2011 Wiley Periodicals, Inc. PMID:21656874

  6. Medial temporal lobe damage impairs representation of simple stimuli.

    PubMed

    Warren, David E; Duff, Melissa C; Tranel, Daniel; Cohen, Neal J

    2010-01-01

    Medial temporal lobe (MTL) damage in humans is typically thought to produce a circumscribed impairment in the acquisition of new enduring memories, but recent reports have documented deficits even in short-term maintenance. We examined possible maintenance deficits in a population of MTL amnesics, with the goal of characterizing their impairments as either representational drift or outright loss of representation over time. Patients and healthy comparisons performed a visual search task in which the similarity of various lures to a target was varied parametrically. Stimuli were simple shapes varying along one of several visual dimensions. The task was performed in two conditions, one presenting a sample target simultaneously with the search array and the other imposing a delay between sample and array. Eye-movement data collected during search revealed that the duration of fixations to items varied with lure-target similarity for all participants, i.e., fixations were longer for items more similar to the target. In the simultaneous condition, patients and comparisons exhibited an equivalent effect of similarity on fixation durations. However, imposing a delay modulated the effect differently for the two groups: in comparisons, fixation duration to similar items was exaggerated; in patients, the original effect was diminished. These findings indicate that MTL lesions subtly impair short-term maintenance of even simple stimuli, with performance reflecting not the complete loss of the maintained representation but rather a degradation or progressive drift of the representation over time.

  7. Structural development and dorsoventral maturation of the medial entorhinal cortex.

    PubMed

    Ray, Saikat; Brecht, Michael

    2016-04-02

    We investigated the structural development of superficial-layers of medial entorhinal cortex and parasubiculum in rats. The grid-layout and cholinergic-innervation of calbindin-positive pyramidal-cells in layer-2 emerged around birth while reelin-positive stellate-cells were scattered throughout development. Layer-3 and parasubiculum neurons had a transient calbindin-expression, which declined with age. Early postnatally, layer-2 pyramidal but not stellate-cells co-localized with doublecortin - a marker of immature neurons - suggesting delayed functional-maturation of pyramidal-cells. Three observations indicated a dorsal-to-ventral maturation of entorhinal cortex and parasubiculum: (i) calbindin-expression in layer-3 neurons decreased progressively from dorsal-to-ventral, (ii) doublecortin in layer-2 calbindin-positive-patches disappeared dorsally before ventrally, and (iii) wolframin-expression emerged earlier in dorsal than ventral parasubiculum. The early appearance of calbindin-pyramidal-grid-organization in layer-2 suggests that this pattern is instructed by genetic information rather than experience. Superficial-layer-microcircuits mature earlier in dorsal entorhinal cortex, where small spatial-scales are represented. Maturation of ventral-entorhinal-microcircuits - representing larger spatial-scales - follows later around the onset of exploratory behavior.

  8. Anterior medial prefrontal cortex implements social priming of mimicry.

    PubMed

    Wang, Yin; Hamilton, Antonia F de C

    2015-04-01

    The neural and cognitive mechanisms by which primed constructs can impact on social behavior are poorly understood. In the present study, we used functional magnetic resonance imaging (fMRI) to explore how scrambled sentence priming can impact on mimicry behavior. Sentences involving pro/antisocial events from a first/third-person point of view were presented in short blocks, followed by a reaction-time assessment of mimicry. Behavioral results showed that both prosociality and viewpoint impact on mimicry, and fMRI analysis showed this effect is implemented by anterior medial prefrontal cortex (amPFC). We suggest that social primes may subtly modulate processing in amPFC in a manner linked to the later behavior, and that this same region also implements the top-down control of mimicry responses. This priming may be linked to processing of self-schemas in amPFC. Our findings demonstrate how social priming can be studied with fMRI, and have important implications for our understanding of the underlying mechanisms of prime-to-behavior effects as well as for current theories in social psychology.

  9. Single-cell recordings in the human medial temporal lobe

    PubMed Central

    Rey, Hernan G; Ison, Matias J; Pedreira, Carlos; Valentin, Antonio; Alarcon, Gonzalo; Selway, Richard; Richardson, Mark P; Quian Quiroga, Rodrigo

    2015-01-01

    Recordings from individual neurons in patients who are implanted with depth electrodes for clinical reasons have opened the possibility to narrow down the gap between neurophysiological studies in animals and non-invasive (e.g. functional magnetic resonance imaging, electroencephalogram, magnetoencephalography) investigations in humans. Here we provide a description of the main procedures for electrode implantation and recordings, the experimental paradigms used and the main steps for processing the data. We also present key characteristics of the so-called ‘concept cells’, neurons in the human medial temporal lobe with selective and invariant responses that represent the meaning of the stimulus, and discuss their proposed role in declarative memory. Finally, we present novel results dealing with the stability of the representation given by these neurons, by studying the effect of stimulus repetition in the strength of the responses. In particular, we show that, after an initial decay, the response strength reaches an asymptotic value after approximately 15 presentations that remains above baseline for the whole duration of the experiment. PMID:25163775

  10. Basket-Weave Technique for Medial Patellofemoral Ligament Reconstruction

    PubMed Central

    Kodkani, Pranjal S.

    2015-01-01

    The anatomy of the medial patellofemoral ligament (MPFL) has been well defined, with parts of its uppermost fibers having a soft-tissue insertion onto the vastus intermedius. Bone tunnels and implants on the patellar side therefore cannot replicate this anatomic construct precisely. Because of implants and tunnels, complications have been reported with bone tunnel fracture. Similarly, on the femoral side, rigid fixation with implants can result in over-constraint with compromised results. Moreover, bone tunnels cannot be used in skeletally immature cases. To overcome issues related to bone tunneling and implants, as well as to reconstruct the MPFL in a precise anatomic manner, an all–soft-tissue fixation technique was devised. Bony landmarks were used as reference points instead of radiologic markers to achieve a more precise construct and to eliminate intraoperative radiography. Hamstring graft was used to reconstruct the MPFL. Special suturing techniques were used to achieve optimal graft fixation with minimal suture knots. A special tissue elevator–suture passer device was designed to facilitate graft passage and ease in performing the procedure. This technique permits differential tensioning, and therefore one achieves stability throughout the range of motion. PMID:26258044

  11. Behavioral control, the medial prefrontal cortex, and resilience

    PubMed Central

    Maier, Steven F.; Amat, Jose; Baratta, Michael V.; Paul, Evan; Watkins, Linda R.

    2006-01-01

    The degree of control that an organism has over a stressor potently modulates the impact of the stressor, with uncontrollable stressors producing a constellation of outcomes that do not occur if the stressor is behaviorally controllable. It has generally been assumed that this occurs because uncontrollability actively potentiates the effects of stressors. Here it will be suggested that in addition, or instead, the presence of control actively inhibits the impact of stressors. At least in part this occurs because (i) the presence of control is detected by regions of the ventral medial prefrontal cortex (mPFCv); and (ii) detection of control activates mPFCv output to stress-responsive brain stem and limbic structures that actively inhibit stress-induced activation of these structures, Furthermore, an initial experience with control over stress alters the mPFCv response to subsequent stressors so that mPFCv output is activated even if the subsequent stressor is uncontrollable, thereby making the organism resilient. The general implications of these results for understanding resilience in the face of adversity are discussed. PMID:17290798

  12. Correlating Function and Imaging Measures of the Medial Longitudinal Fasciculus

    PubMed Central

    Sakaie, Ken; Takahashi, Masaya; Remington, Gina; Wang, Xiaofeng; Conger, Amy; Conger, Darrel; Dimitrov, Ivan; Jones, Stephen; Frohman, Ashley; Frohman, Teresa; Sagiyama, Koji; Togao, Osamu

    2016-01-01

    Objective To test the validity of diffusion tensor imaging (DTI) measures of tissue injury by examining such measures in a white matter structure with well-defined function, the medial longitudinal fasciculus (MLF). Injury to the MLF underlies internuclear ophthalmoparesis (INO). Methods 40 MS patients with chronic INO and 15 healthy controls were examined under an IRB-approved protocol. Tissue integrity of the MLF was characterized by DTI parameters: longitudinal diffusivity (LD), transverse diffusivity (TD), mean diffusivity (MD) and fractional anisotropy (FA). Severity of INO was quantified by infrared oculography to measure versional disconjugacy index (VDI). Results LD was significantly lower in patients than in controls in the medulla-pons region of the MLF (p < 0.03). FA was also lower in patients in the same region (p < 0.0004). LD of the medulla-pons region correlated with VDI (R = -0.28, p < 0.05) as did FA in the midbrain section (R = 0.31, p < 0.02). Conclusions This study demonstrates that DTI measures of brain tissue injury can detect injury to a functionally relevant white matter pathway, and that such measures correlate with clinically accepted evaluation indices for INO. The results validate DTI as a useful imaging measure of tissue integrity. PMID:26800522

  13. A general role for medial prefrontal cortex in event prediction

    PubMed Central

    Alexander, William H.; Brown, Joshua W.

    2014-01-01

    A recent computational neural model of medial prefrontal cortex (mPFC), namely the predicted response-outcome (PRO) model (Alexander and Brown, 2011), suggests that mPFC learns to predict the outcomes of actions. The model accounted for a wide range of data on the mPFC. Nevertheless, numerous recent findings suggest that mPFC may signal predictions and prediction errors even when the predicted outcomes are not contingent on prior actions. Here we show that the existing PRO model can learn to predict outcomes in a general sense, and not only when the outcomes are contingent on actions. A series of simulations show how this generalized PRO model can account for an even broader range of findings in the mPFC, including human ERP, fMRI, and macaque single-unit data. The results suggest that the mPFC learns to predict salient events in general and provides a theoretical framework that links mPFC function to model-based reinforcement learning, Bayesian learning, and theories of cognitive control. PMID:25071539

  14. Role of the medial prefrontal cortex in coping and resilience *

    PubMed Central

    Maier, Steven F.; Watkins, Linda R.

    2010-01-01

    The degree of behavioral control that an organism has over an aversive event is well known to modulate the behavioral and neurochemical consequences of exposure to the event. Here we review recent research that suggests that the experience of control over a potent stressor alters how the organism responds to future aversive events as well as to the stressor being controlled. More specifically, subjects that have experienced control show blunted behavioral and neurochemical responses to subsequent stressors occurring days to months later. Indeed, these subjects respond as if a later uncontrollable stressor is actually controllable. Further, we review research indicating that the stress-resistance induced by control depends on control-induced activation of ventral medial prefrontal cortical (vmPFC) inhibitory control over brainstem and limbic structures. Furthermore, there appears to be plasticity in these circuits such that the experience of control alters the vmPFC in such a way that later uncontrollable stressors now activate the vmPFC circuitry, leading to inhibition of stress-responsive limbic and brainstem structures, i.e., stressor resistance. This controllability-induced proactive stressor resistance generalizes across very different stressors and may be involved in determining individual difference in reactions to traumatic events. PMID:20727864

  15. Structural development and dorsoventral maturation of the medial entorhinal cortex

    PubMed Central

    Ray, Saikat; Brecht, Michael

    2016-01-01

    We investigated the structural development of superficial-layers of medial entorhinal cortex and parasubiculum in rats. The grid-layout and cholinergic-innervation of calbindin-positive pyramidal-cells in layer-2 emerged around birth while reelin-positive stellate-cells were scattered throughout development. Layer-3 and parasubiculum neurons had a transient calbindin-expression, which declined with age. Early postnatally, layer-2 pyramidal but not stellate-cells co-localized with doublecortin – a marker of immature neurons – suggesting delayed functional-maturation of pyramidal-cells. Three observations indicated a dorsal-to-ventral maturation of entorhinal cortex and parasubiculum: (i) calbindin-expression in layer-3 neurons decreased progressively from dorsal-to-ventral, (ii) doublecortin in layer-2 calbindin-positive-patches disappeared dorsally before ventrally, and (iii) wolframin-expression emerged earlier in dorsal than ventral parasubiculum. The early appearance of calbindin-pyramidal-grid-organization in layer-2 suggests that this pattern is instructed by genetic information rather than experience. Superficial-layer-microcircuits mature earlier in dorsal entorhinal cortex, where small spatial-scales are represented. Maturation of ventral-entorhinal-microcircuits – representing larger spatial-scales – follows later around the onset of exploratory behavior. DOI: http://dx.doi.org/10.7554/eLife.13343.001 PMID:27036175

  16. Medial Prefrontal Cortex Reduces Memory Interference by Modifying Hippocampal Encoding.

    PubMed

    Guise, Kevin G; Shapiro, Matthew L

    2017-04-05

    The prefrontal cortex (PFC) is crucial for accurate memory performance when prior knowledge interferes with new learning, but the mechanisms that minimize proactive interference are unknown. To investigate these, we assessed the influence of medial PFC (mPFC) activity on spatial learning and hippocampal coding in a plus maze task that requires both structures. mPFC inactivation did not impair spatial learning or retrieval per se, but impaired the ability to follow changing spatial rules. mPFC and CA1 ensembles recorded simultaneously predicted goal choices and tracked changing rules; inactivating mPFC attenuated CA1 prospective coding. mPFC activity modified CA1 codes during learning, which in turn predicted how quickly rats adapted to subsequent rule changes. The results suggest that task rules signaled by the mPFC become incorporated into hippocampal representations and support prospective coding. By this mechanism, mPFC activity prevents interference by "teaching" the hippocampus to retrieve distinct representations of similar circumstances.

  17. Assessing cognitive function following medial prefrontal stroke in the rat.

    PubMed

    Livingston-Thomas, Jessica M; Jeffers, Matthew S; Nguemeni, Carine; Shoichet, Molly S; Morshead, Cindi M; Corbett, Dale

    2015-11-01

    Cognitive impairments are prevalent following clinical stroke; however, preclinical research has focused almost exclusively on motor deficits. In order to conduct systematic evaluations into the nature of post-stroke cognitive dysfunction and recovery, it is crucial to develop focal stroke models that predominantly affect cognition while leaving motor function intact. Herein, we evaluated a range of cognitive functions 1-4 months following focal medial prefrontal cortex (mPFC) stroke using a battery of tests. Male Sprague-Dawley rats underwent focal ischemia induced in the mPFC using bilateral intracerebral injections of endothelin-1, or sham surgery. Cognitive function was assessed using an open field, several object recognition tests, attentional set-shifting, light-dark box, spontaneous alternation, Barnes maze, and win-shift/win-stay tests. Prefrontal cortex damage resulted in significant changes in object recognition function, behavioural flexibility, and anxiety-like behaviour, while spontaneous alternation and locomotor function remained intact. These deficits are similar to the cognitive deficits following stroke in humans. Our results suggest that this model may be useful for identifying and developing potential therapies for improving post-stroke cognitive dysfunction.

  18. Capsaicin augments synaptic transmission in the rat medial preoptic nucleus.

    PubMed

    Karlsson, Urban; Sundgren-Andersson, Anna K; Johansson, Staffan; Krupp, Johannes J

    2005-05-10

    The medial preoptic nucleus (MPN) is the major nucleus of the preoptic area (POA), a hypothalamic area involved in the regulation of body-temperature. Injection of capsaicin into this area causes hypothermia in vivo. Capsaicin also causes glutamate release from hypothalamic slices. However, no data are available on the effect of capsaicin on synaptic transmission within the MPN. Here, we have studied the effect of exogenously applied capsaicin on spontaneous synaptic activity in hypothalamic slices of the rat. Whole-cell patch-clamp recordings were made from visually identified neurons located in the MPN. In a subset of the studied neurons, capsaicin enhanced the frequency of spontaneous glutamatergic EPSCs. Remarkably, capsaicin also increased the frequency of GABAergic IPSCs, an effect that was sensitive to removal of extracellular calcium, but insensitive to tetrodotoxin. This suggests an action of capsaicin at presynaptic GABAergic terminals. In contrast to capsaicin, the TRPV4 agonist 4alpha-PDD did not affect GABAergic IPSCs. Our results show that capsaicin directly affects synaptic transmission in the MPN, likely through actions at presynaptic terminals as well as on projecting neurons. Our data add to the growing evidence that capsaicin receptors are not only expressed in primary afferent neurons, but also contribute to synaptic processing in some CNS regions.

  19. Transient medial prefrontal perturbation reduces false memory formation.

    PubMed

    Berkers, Ruud M W J; van der Linden, Marieke; de Almeida, Rafael F; Müller, Nils C J; Bovy, Leonore; Dresler, Martin; Morris, Richard G M; Fernández, Guillén

    2017-03-01

    Knowledge extracted across previous experiences, or schemas, benefit encoding and retention of congruent information. However, they can also reduce specificity and augment memory for semantically related, but false information. A demonstration of the latter is given by the Deese-Roediger-McDermott (DRM) paradigm, where the studying of words that fit a common semantic schema are found to induce false memories for words that are congruent with the given schema, but were not studied. The medial prefrontal cortex (mPFC) has been ascribed the function of leveraging prior knowledge to influence encoding and retrieval, based on imaging and patient studies. Here, we used transcranial magnetic stimulation (TMS) to transiently perturb ongoing mPFC processing immediately before participants performed the DRM-task. We observed the predicted reduction in false recall of critical lures after mPFC perturbation, compared to two control groups, whereas veridical recall and recognition memory performance remained similar across groups. These data provide initial causal evidence for a role of the mPFC in biasing the assimilation of new memories and their consolidation as a function of prior knowledge.

  20. Medial PFC Damage Abolishes the Self-reference Effect

    PubMed Central

    Philippi, Carissa L.; Duff, Melissa C.; Denburg, Natalie L.; Tranel, Daniel; Rudrauf, David

    2012-01-01

    Functional neuroimaging studies suggest that the medial PFC (mPFC) is a key component of a large-scale neural system supporting a variety of self-related processes. However, it remains unknown whether the mPFC is critical for such processes. In this study, we used a human lesion approach to examine this question. We administered a standard trait judgment paradigm [Kelley, W. M., Macrae, C. N., Wyland, C. L., Caglar, S., Inati, S., & Heatherton, T. F. Finding the self? An event-related fMRI study. Journal of Cognitive Neuroscience, 14, 785–794, 2002] to patients with focal brain damage to the mPFC. The self-reference effect (SRE), a memory advantage conferred by self-related processing, served as a measure of intact self-processing ability. We found that damage to the mPFC abolished the SRE. The results demonstrate that the mPFC is necessary for the SRE and suggest that this structure is important for self-referential processing and the neural representation of self. PMID:21942762

  1. CP Violation, Neutral Currents, and Weak Equivalence

    DOE R&D Accomplishments Database

    Fitch, V. L.

    1972-03-23

    Within the past few months two excellent summaries of the state of our knowledge of the weak interactions have been presented. Correspondingly, we will not attempt a comprehensive review but instead concentrate this discussion on the status of CP violation, the question of the neutral currents, and the weak equivalence principle.

  2. On modeling weak sinks in MODPATH

    USGS Publications Warehouse

    Abrams, Daniel B.; Haitjema, Henk; Kauffman, Leon J.

    2012-01-01

    Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that water to pass. A physical strong sink can be modeled by either a strong sink cell or a weak sink cell, with the latter generally occurring in low resolution models. Likewise, a physical weak sink may also be represented by either type of sink cell. The representation of weak sinks in the particle tracing code MODPATH is more equivocal than in MODFLOW. With the appropriate parameterization of MODPATH, particle traces and their associated travel times to weak sink streams can be modeled with adequate accuracy, even in single layer models. Weak sink well cells, on the other hand, require special measures as proposed in the literature to generate correct particle traces and individual travel times and hence capture zones. We found that the transit time distributions for well water generally do not require special measures provided aquifer properties are locally homogeneous and the well draws water from the entire aquifer depth, an important observation for determining the response of a well to non-point contaminant inputs.

  3. On modeling weak sinks in MODPATH.

    PubMed

    Abrams, Daniel; Haitjema, H; Kauffman, L

    2013-01-01

    Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that water to pass. A physical strong sink can be modeled by either a strong sink cell or a weak sink cell, with the latter generally occurring in low-resolution models. Likewise, a physical weak sink may also be represented by either type of sink cell. The representation of weak sinks in the particle tracing code MODPATH is more equivocal than in MODFLOW. With the appropriate parameterization of MODPATH, particle traces and their associated travel times to weak sink streams can be modeled with adequate accuracy, even in single layer models. Weak sink well cells, on the other hand, require special measures as proposed in the literature to generate correct particle traces and individual travel times and hence capture zones. We found that the transit time distributions for well water generally do not require special measures provided aquifer properties are locally homogeneous and the well draws water from the entire aquifer depth, an important observation for determining the response of a well to non-point contaminant inputs.

  4. Spin Seebeck effect in a weak ferromagnet

    NASA Astrophysics Data System (ADS)

    Arboleda, Juan David; Arnache Olmos, Oscar; Aguirre, Myriam Haydee; Ramos, Rafael; Anadon, Alberto; Ibarra, Manuel Ricardo

    2016-06-01

    We report the observation of room temperature spin Seebeck effect (SSE) in a weak ferromagnetic normal spinel Zinc Ferrite (ZFO). Despite the weak ferromagnetic behavior, the measurements of the SSE in ZFO show a thermoelectric voltage response comparable with the reported values for other ferromagnetic materials. Our results suggest that SSE might possibly originate from the surface magnetization of the ZFO.

  5. Few body hypernuclear systems: Weak decays

    SciTech Connect

    Dover, C.B.

    1987-01-01

    The experimental and theoretical situation regarding mesonic and non-mesonic decays of light hypernuclei is reviewed. Although some models give reasonable results for pionic decays as well as the total weak decay rate, no existing approach explains, even qualitatively, the observed spin-isospin dependence of ..lambda..N ..-->.. NN non-mesonic weak decays. 31 refs., 2 figs.

  6. Miniarthrotomy assisted percutaneous screw fixation for displaced medial malleolus fractures – A novel technique

    PubMed Central

    Saini, Pramod; Aggrawal, Abhinav; Meena, Sanjay; Trikha, Vivek; Mittal, Samarth

    2014-01-01

    Aim To describe here a technique of miniarthrotomy assisted percutaneous screw insertion for displaced Herscovici type B and C medial malleolar fractures. Method Incision was made centred over the superomedial angle of the ankle mortise, about half a cm medial to tibialis anterior. Arthrotomy was done and reduction obtained. Percuntaneously, two 4 mm cancellous cannulated screws were inserted through medial malleolus. Results and conclusion This approach allows direct visualization of reduction, removal of entrapped soft tissue and preservation of saphenous vein and nerve. PMID:25983507

  7. Treatment of medial and posteromedial knee instability: indications, techniques, and review of the results.

    PubMed

    Bonasia, D E; Bruzzone, M; Dettoni, F; Marmotti, A; Blonna, D; Castoldi, F; Gasparetto, F; D'Elicio, D; Collo, G; Rossi, R

    2012-01-01

    Injuries of the posteromedial corner of the knee are relatively common. These can be isolated or combined with other ligament lesions. In some cases the treatment of postero-medial corner injuries is controversial. After a brief description of the anatomy and biomechanics of the medial side of the knee, this paper reviews the indications for isolated and multiligamentous medial/posteromedial corner injuries both in the acute and in the chronic setting. In addition, the most common surgical techniques for repair and reconstruction are described in addition to outcomes based upon a review of the literature.

  8. Ulnar entrapment neuropathy along the medial intermuscular septum in the midarm.

    PubMed

    Nakajima, Masashi; Ono, Nobuko; Kojima, Tomoko; Kusunose, Koichi

    2009-05-01

    We report a patient with primary ulnar entrapment neuropathy in the midarm. Stimulation of multiple sites along the ulnar nerve showed a motor conduction block at a distance of 7.5-10 cm proximal to the medial epicondyle, where the nerve was compressed by the medial intermuscular septum. Anatomically, the possibility of ulnar nerve entrapment in this segment has long been suggested, and stimulation at least 10 cm above the medial epicondyle may reveal the entrapment. Muscle Nerve 39: 707-710, 2009.

  9. Medial pterygoid trismus (myospasm) following inferior alveolar nerve block: case report and literature review.

    PubMed

    Wright, Edward F

    2011-01-01

    A patient developed a medial pterygoid trismus (myospasm) the day after receiving three inferior alveolar nerve blocks and a routine restoration. She had a significantly restricted mouth opening and significant medial pterygoid muscle pain when she opened beyond the restriction; however, she had no swelling, lymphadenopathy, or fever. A medial pterygoid myospasm can occur secondary to an inferior alveolar nerve block. This disorder generally is treated by the application of heat, muscle stretches, analgesic and/or muscle relaxant ingestion, and a physical therapy referral. The severity of the disorder typically dictates the extent of therapy that is needed.

  10. Weak-value amplification: state of play

    NASA Astrophysics Data System (ADS)

    Knee, George C.; Combes, Joshua; Ferrie, Christopher; Gauger, Erik M.

    2016-01-01

    Weak values arise in quantum theory when the result of a weak measurement is conditioned on a subsequent strong measurement. The majority of the trials are discarded, leaving only very few successful events. Intriguingly those can display a substantial signal amplification. This raises the question of whether weak values carry potential to improve the performance of quantum sensors, and indeed a number of impressive experimental results suggested this may be the case. By contrast, recent theoretical studies have found the opposite: using weak-values to obtain an amplification generally worsens metrological performance. This survey summarises the implications of those studies, which call for a reappraisal of weak values' utility and for further work to reconcile theory and experiment.

  11. The control of eye movements by the cerebellar nuclei: polysynaptic projections from the fastigial, interpositus posterior and dentate nuclei to lateral rectus motoneurons in primates.

    PubMed

    Prevosto, Vincent; Graf, Werner; Ugolini, Gabriella

    2017-02-22

    Premotor circuits driving extraocular motoneurons and downstream motor outputs of cerebellar nuclei are well known. However, there is, as yet, no unequivocal account of cerebellar output pathways controlling eye movements in primates. Using retrograde transneuronal transfer of rabies virus from the lateral rectus (LR) eye muscle, we studied polysynaptic pathways to LR motoneurons in primates. Injections were placed either into the central or distal muscle portion, to identify innervation differences of LR motoneurons supplying singly innervated (SIFs) or multiply innervated muscle fibers (MIFs). We found that SIF motoneurons receive major cerebellar 'output channels' bilaterally, while oligosynaptic cerebellar innervation of MIF motoneurons is negligible and/or more indirect. Inputs originate from the fastigial nuclei di- and trisynaptically, and from a circumscribed rostral portion of the ventrolateral interpositus posterior and from the caudal pole of the dentate nuclei trisynaptically. While disynaptic cerebellar inputs to LR motoneurons stem exclusively from the caudal fastigial region involved in saccades, pursuit and convergence (via its projections to brainstem oculomotor populations), minor trisynaptic inputs from the rostral fastigial nucleus, which contributes to gaze shifts, may reflect access to vestibular and reticular eye-head control pathways. Trisynaptic inputs to LR motoneurons from the rostral ventrolateral interpositus posterior, involved in divergence (far-response), is likely mediated by projections to the supraoculomotor area, contributing to LR motoneuron activation during divergence. Trisynaptic inputs to LR motoneurons from the caudal dentate, which also innervates disynaptically the frontal and parietal eye fields, can be explained by its superior colliculus projections, and likely target saccade-related burst neurons.

  12. Ultrasound-guided rectus sheath and transversus abdominis plane blocks for perioperative analgesia in upper abdominal surgery: A randomized controlled study

    PubMed Central

    Abdelsalam, Khaled; Mohamdin, OW

    2016-01-01

    Background: Regional anesthetic techniques can be used to alleviate postoperative pain in patients undergoing major upper abdominal surgery. Our aim was to evaluate the efficacy of bilateral ultrasound (US)-guided rectus sheath (RS) and transversus abdominis plane (TAP) blocks for better perioperative analgesia. Patients and Methods: It is a prospective, observer-blinded, randomized clinical study. 40 eligible patients undergoing elective liver resection or Whipple procedure were included. All patients received a standardized anesthetic technique. Group 1 (n = 20) received preincisional US-guided bilateral RS and TAP blocks using 20 ml volume of bupivacaine 0.25% for each, and group 2 (n = 20) received local wound infiltration at end of surgery with 40 ml of bupivacaine 0.25%. A standardized postoperative analgesic regimen composed of intravenous paracetamol and a morphine patient-controlled analgesia (PCA). The use of intraoperative fentanyl and recovery room morphine boluses, PCA-administered morphine, pain scores as well as number of patients’ experienced postoperative nausea and vomiting in the ward at 6 and 24 h were recorded. Results: Group 1 patients received a significantly lower cumulative intraoperative fentanyl, significantly lesser boluses of morphine in postanesthesia care unit, as well, significantly lower cumulative 24 h postoperative morphine dosage than the group 2 patients. Pain visual analog scale scores were significantly lower at both 6 and 24 h postoperatively in TAP group when compared with the no-TAP group. There were no complications related to the TAP block procedures. No signs or symptoms of local anesthetic systemic toxicity were detected. Conclusion: The combination of bilateral US-guided RS and TAP blocks provides excellent perioperative analgesia for major upper abdominal surgery. PMID:26955306

  13. Pain related to robotic cholecystectomy with lower abdominal ports: effect of the bilateral ultrasound-guided split injection technique of rectus sheath block in female patients

    PubMed Central

    Kim, Jin Soo; Choi, Jong Bum; Lee, Sook Young; Kim, Wook Hwan; Baek, Nam Hyun; Kim, Jayoun; Park, Chu Kyung; Lee, Yeon Ju; Park, Sung Yong

    2016-01-01

    Abstract Background: Robotic cholecystectomy (RC) using port sites in the lower abdominal area (T12-L1) rather than the upper abdomen has recently been introduced as an alternative procedure for laparoscopic cholecystectomy. Therefore, we investigated the time course of different components of pain and the analgesic effect of the bilateral ultrasound-guided split injection technique for rectus sheath block (sRSB) after RC in female patients. Methods: We randomly assigned 40 patients to undergo ultrasound-guided sRSB (RSB group, n = 20) or to not undergo any block (control group, n = 20). Pain was subdivided into 3 components: superficial wound pain, deep abdominal pain, and referred shoulder pain, which were evaluated with a numeric rating scale (from 0 to 10) at baseline (time of awakening) and at 1, 6, 9, and 24 hours postoperatively. Consumption of fentanyl and general satisfaction were also evaluated 1 hour (before discharge from the postanesthesia care unit) and 24 hours postoperatively (end of study). Results: Superficial wound pain was predominant only at awakening, and after postoperative 1 hour in the control group. Bilateral ultrasound-guided sRSB significantly decreased superficial pain after RC (P < 0.01) and resulted in a better satisfaction score (P < 0.05) 1 hour after RC in the RSB group compared with the control group. The cumulative postoperative consumption of fentanyl at 6, 9, and 24 hours was not significantly different between groups. Conclusions: After RC with lower abdominal ports, superficial wound pain predominates over deep intra-abdominal pain and shoulder pain only at the time of awakening. Afterwards, superficial and deep pain decreased to insignificant levels in 6 hours. Bilateral ultrasound-guided sRSB was effective only during the first hour. This limited benefit should be balanced against the time and risks entailed in performing RSB. PMID:27495072

  14. Spectrum of Mathematical Weaknesses: Related Neuropsychological Correlates.

    PubMed

    Perna, Robert; Loughan, Ashlee R; Le, Jessica; Hertza, Jeremy; Cohen, Morris J

    2015-01-01

    Math disorders have been recognized for as long as language disorders yet have received far less research. Mathematics is a complex construct and its development may be dependent on multiple cognitive abilities. Several studies have shown that short-term memory, working memory, visuospatial skills, processing speed, and various language skills relate to and may facilitate math development and performance. The hypotheses explored in this research were that children who performed worse on math achievement than on Full-Scale IQ would exhibit weaknesses in executive functions, memory, and visuoperceptual skills. Participants included 436 children (27% girls, 73% boys; age range = 5-17 years, M(age) = 9.45 years) who were referred for neuropsychological evaluations due to academic and/or behavioral problems. This article specifically focuses on the spectrum of math weakness rather than clinical disability, which has yet to be investigated in the literature. Results suggest that children with relative weakness to impairments in math were significantly more likely to have cognitive weaknesses to impairments on neuropsychological variables, as compared with children without math weaknesses. Specifically, the math-weak children exhibit a weakness to impairment on measures involving attention, language, visuoperceptual skills, memory, reading, and spelling. Overall, our results suggest that math development is multifaceted.

  15. Assessment of medial and lateral neurovascular structures after percutaneous posterior calcaneal displacement osteotomy: a cadaver study.

    PubMed

    Didomenico, Lawrence A; Anain, Joseph; Wargo-Dorsey, Mari

    2011-01-01

    A prospective investigation of the effects on the medial and lateral neurovascular structures of the rearfoot after percutaneous posterior calcaneal displacement osteotomy was performed using 20 below the knee fresh frozen cadaver specimens. This anatomic study aimed to examine the medial and lateral neurovascular structures to determine whether they were jeopardized during execution of the osteotomy. After completion of the osteotomy, the medial plantar, lateral plantar, medial calcaneal, sural, and posterior tibial neurovascular structures, along with their respective branches, were inspected for iatrogenic injury. Our findings demonstrated that the percutaneous, subperiosteal osteotomy minimized trauma to the local soft tissue envelope and protected the adjacent neurovascular structures. Because no iatrogenic injury was observed in the cadaveric specimens, we postulated that percutaneous calcaneal displacement osteotomy is a safe, predictable, and advantageous alternative compared with open techniques for osteotomy and could result in reduced postoperative complications. The results of this investigation remain to be confirmed in the clinical setting.

  16. Biomechanical validation of medial pie-crusting for soft-tissue balancing in knee arthroplasty.

    PubMed

    Mihalko, William M; Woodard, Erik L; Hebert, Casey T; Crockarell, John R; Williams, John L

    2015-02-01

    Balancing a varus knee is traditionally accomplished by releasing the medial soft-tissue sleeve off the tibia. Recently, "pie-crusting" (PC) medial structures has been described. In a biomechanical cadaver study we compared PC to traditional release (TR) to determine their effects on flexion and extension gaps. PC was done in five specimens along the anterior half of the medial soft-tissue sleeve and five along the posterior half, followed by a traditional release. In 90° flexion, valgus laxity after TR was significantly greater than after PC alone. PC of the anterior or posterior aspect of the medial soft-tissue sleeve can effect changes more in flexion than in extension, respectively. Complete TR did not provide more gap opening than PC in extension, but produced more effect in flexion.

  17. Recruitment of the Rhesus soleus and medial gastrocnemius before, during and after spaceflight

    NASA Technical Reports Server (NTRS)

    Roy, R. R.; Hodgson, J. A.; Aragon, J.; Day, M. K.; Kozlovskaya, I.; Edgerton, V. R.

    1996-01-01

    Electromyograms were recorded from the soleus and medial gastrocnemius muscles and tendon force from the medial gastrocnemius muscle of 2 juvenile Rhesus monkeys before, during and after Cosmos flight 2229 and of ground control animals. Recording sessions were made while the Rhesus were performing a foot pedal motor task. Preflight testing indicated normal patterns of recruitment between the soleus and medial gastrocnemius, i.e. a higher level of recruitment of the soleus compared to the medial gastrocnemius during the task. Recording began two days into the spaceflight and showed that the media gastrocnemius was recruited preferentially over the soleus. This observation persisted throughout the flight and for the 2 week period of postflight testing. These data indicate a significant change in the relative recruitment of slow and fast extensor muscles under microgravity conditions. The appearance of clonic-like activity in one muscle of each Rhesus during flight further suggests a reorganization in the neuromotor system in a microgravity environment.

  18. Avulsion of the anterior medial meniscus root: case report and surgical technique.

    PubMed

    Feucht, Matthias J; Minzlaff, Philipp; Saier, Tim; Lenich, Andreas; Imhoff, Andreas B; Hinterwimmer, Stefan

    2015-01-01

    Injuries of the meniscus roots have become increasingly recognised as a serious pathology of the knee joint. However, the current available literature focuses primarily on posterior meniscus root tears. In this article, a case with an isolated avulsion of the anterior medial meniscus root is presented, and a new arthroscopic technique to treat this type of injury is described. The anterior horn of the medial meniscus was sutured with a double-looped nonabsorbable suture and reattached to the tibial plateau using a knotless suture anchor. This technique may also be useful to treat avulsion injuries of the anterolateral or posteromedial meniscus root, and symptomatic subluxation of the medial meniscus in case of a variant insertion anatomy with an absent attachment of the anterior horn of the medial meniscus to the tibial plateau. Level of evidence V.

  19. Sural artery injury with arteriovenous fistula: case report about a rare complication following arthroscopic medial meniscectomy

    PubMed Central

    In den Kleef, Nick J.H.M.; Konings, Peer C.; Smeets, Luuk

    2015-01-01

    This case report presents a patient with hematoma and pain after a knee arthroscopy with partial medial meniscectomy. A lesion of the sural artery was treated by endovascular coiling. The level of evidence is IV. PMID:25656167

  20. Cellular components of the human medial amygdaloid nucleus.

    PubMed

    Dall'Oglio, Aline; Xavier, Léder L; Hilbig, Arlete; Ferme, Denise; Moreira, Jorge E; Achaval, Matilde; Rasia-Filho, Alberto A

    2013-02-15

    The medial nucleus (Me) is a superficial component of the amygdaloid complex. Here we assessed the density and morphology of the neurons and glial cells, the glial fibrillary acidic protein (GFAP) immunoreactivity, and the ultrastructure of the synaptic sites in the human Me. The optical fractionator method was applied. The Me presented an estimated mean neuronal density of 1.53 × 10⁵ neurons/mm³ (greater in the left hemisphere), more glia (72% of all cells) than neurons, and a nonneuronal:neuronal ratio of 2.7. Golgi-impregnated neurons had round or ovoid, fusiform, angular, and polygonal cell bodies (10-30 μm in diameter). The length of the dendrites varied, and pleomorphic spines were found in sparsely spiny or densely spiny cells (1.5-5.2 spines/dendritic μm). The axons in the Me neuropil were fine or coarsely beaded, and fibers showed simple or notably complex collateral terminations. The protoplasmic astrocytes were either isolated or formed small clusters and showed GFAP-immunoreactive cell bodies and multiple branches. Furthermore, we identified both asymmetrical (with various small, clear, round, electron-lucent vesicles and, occasionally, large, dense-core vesicles) and symmetrical (with small, flattened vesicles) axodendritic contacts, also including multisynaptic spines. The astrocytes surround and may compose tripartite or tetrapartite synapses, the latter including the extracellular matrix between the pre- and the postsynaptic elements. Interestingly, the terminal axons exhibited a glomerular-like structure with various asymmetrical contacts. These new morphological data on the cellular population and synaptic complexity of the human Me can contribute to our knowledge of its role in health and pathological conditions.

  1. Fear Expression Suppresses Medial Prefrontal Cortical Firing in Rats

    PubMed Central

    Giustino, Thomas F.; Fitzgerald, Paul J.; Maren, Stephen

    2016-01-01

    The medial prefrontal cortex (mPFC) plays a crucial role in emotional learning and memory in rodents and humans. While many studies suggest a differential role for the prelimbic (PL) and infralimbic (IL) subdivisions of mPFC, few have considered the relationship between neural activity in these two brain regions recorded simultaneously in behaving animals. Importantly, how concurrent PL and IL activity relate to conditioned freezing behavior is largely unknown. Here we used single-unit recordings targeting PL and IL in awake, behaving rats during the acquisition and expression of conditioned fear. On Day 1, rats received either signaled or unsignaled footshocks in the recording chamber; an auditory conditioned stimulus (CS) preceded signaled footshocks. Twenty-four hours later, animals were returned to the recording chamber (modified to create a novel context) where they received 5 CS-alone trials. After fear conditioning, both signaled and unsignaled rats exhibited high levels of post-shock freezing that was associated with an enduring suppression of mPFC spontaneous firing, particularly in the IL of signaled rats. Twenty-four hours later, CS presentation produced differential conditioned freezing in signaled and unsignaled rats: freezing increased in rats that had received signaled shocks, but decreased in animals in the unsignaled condition (i.e., external inhibition). This group difference in CS-evoked freezing was mirrored in the spontaneous firing rate of neurons in both PL and IL. Interestingly, differences in PL and IL firing rate highly correlated with freezing levels. In other words, in the signaled group IL spontaneous rates were suppressed relative to PL, perhaps limiting IL-mediated suppression of fear and allowing PL activity to dominate performance, resulting in high levels of freezing. This was not observed in the unsignaled group, which exhibited low freezing. These data reveal that the activity of mPFC neurons is modulated by both associative and

  2. Visualization of the medial forebrain bundle using diffusion tensor imaging.

    PubMed

    Hana, Ardian; Hana, Anisa; Dooms, Georges; Boecher-Schwarz, Hans; Hertel, Frank

    2015-01-01

    Diffusion tensor imaging is a technique that enables physicians the portrayal of white matter tracts in vivo. We used this technique in order to depict the medial forebrain bundle (MFB) in 15 consecutive patients between 2012 and 2015. Men and women of all ages were included. There were six women and nine men. The mean age was 58.6 years (39-77). Nine patients were candidates for an eventual deep brain stimulation. Eight of them suffered from Parkinson's disease and one had multiple sclerosis. The remaining six patients suffered from different lesions which were situated in the frontal lobe. These were 2 metastasis, 2 meningiomas, 1 cerebral bleeding, and 1 glioblastoma. We used a 3DT1-sequence for the navigation. Furthermore T2- and DTI- sequences were performed. The FOV was 200 × 200 mm(2), slice thickness 2 mm, and an acquisition matrix of 96 × 96 yielding nearly isotropic voxels of 2 × 2 × 2 mm. 3-Tesla-MRI was carried out strictly axial using 32 gradient directions and one b0-image. We used Echo-Planar-Imaging (EPI) and ASSET parallel imaging with an acceleration factor of 2. b-value was 800 s/mm(2). The maximal angle was 50°. Additional scanning time was < 9 min. We were able to visualize the MFB in 12 of our patients bilaterally and in the remaining three patients we depicted the MFB on one side. It was the contralateral side of the lesion. These were 2 meningiomas and one metastasis. Portrayal of the MFB is possible for everyday routine for neurosurgical interventions. As part of the reward circuitry it might be of substantial importance for neurosurgeons during deep brain stimulation in patients with psychiatric disorders. Surgery in this part of the brain should always take the preservation of this white matter tract into account.

  3. Anatomical segmentation of the human medial prefrontal cortex.

    PubMed

    Córcoles-Parada, M; Müller, Ncj; Ubero, M; Serrano-Del-Pueblo, V M; Mansilla, F; Marcos-Rabal, P; Artacho-Pérula, E; Dresler, M; Insausti, R; Fernández, G; Muñoz-López, M

    2017-03-20

    The medial prefrontal areas 32, 24, 14, and 25 (mPFC) form part of the limbic memory system, but little is known about their functional specialization in humans. To add anatomical precision to structural and functional MRI data, we aimed to identify these mPFC subareas in histological preparations of human brain tissue, determine sulci most consistently related with mPFC areal boundaries, and use these sulci to delineate mPFC areas in MRIs. To achieve this, we obtained 3D MRI data from 11 ex vivo hemispheres and processed them for cyto- and myelo-architectonic analysis. The architectonic boundaries of mPFC areas were identified in histology and cortical surface length and volumes were measured. Unfolded maps of histologically determined boundaries were generated to identify the association of mPFC areal boundaries with sulci across cases. This analysis showed that cingulate and superior rostral were the sulci most consistently related to mPFC areal boundaries. Based on presence/absence and anastomosis between such sulci, 6 sulci patterns in the 11 hemispheres were found. A further analysis of 102 hemispheres of in vivo MRI scans (N=51 males, mean±sd 24.1±3.1 years of age) showed similar sulci patterns, which allowed us to delineate the mFPC areas in them. The volumes of mPFC areas across histological, ex vivo and in vivo MRI delineations were comparable and probabilistic maps generated from the MRIs of the102 hemispheres. Probabilistic maps of mPFC areas were registered to MNI space and are available for regional analysis of fMRI data. This article is protected by copyright. All rights reserved.

  4. Medial olivocochlear efferent reflex inhibition of human cochlear nerve responses.

    PubMed

    Lichtenhan, J T; Wilson, U S; Hancock, K E; Guinan, J J

    2016-03-01

    Inhibition of cochlear amplifier gain by the medial olivocochlear (MOC) efferent system has several putative roles: aiding listening in noise, protection against damage from acoustic overexposure, and slowing age-induced hearing loss. The human MOC reflex has been studied almost exclusively by measuring changes in otoacoustic emissions. However, to help understand how the MOC system influences what we hear, it is important to have measurements of the MOC effect on the total output of the organ of Corti, i.e., on cochlear nerve responses that couple sounds to the brain. In this work we measured the inhibition produced by the MOC reflex on the amplitude of cochlear nerve compound action potentials (CAPs) in response to moderate level (52-60 dB peSPL) clicks from five, young, normal hearing, awake, alert, human adults. MOC activity was elicited by 65 dB SPL, contralateral broadband noise (CAS). Using tympanic membrane electrodes, approximately 10 h of data collection were needed from each subject to yield reliable measurements of the MOC reflex inhibition on CAP amplitudes from one click level. The CAS produced a 16% reduction of CAP amplitude, equivalent to a 1.98 dB effective attenuation (averaged over five subjects). Based on previous reports of efferent effects as functions of level and frequency, it is possible that much larger effective attenuations would be observed at lower sound levels or with clicks of higher frequency content. For a preliminary comparison, we also measured MOC reflex inhibition of DPOAEs evoked from the same ears with f2's near 4 kHz. The resulting effective attenuations on DPOAEs were, on average, less than half the effective attenuations on CAPs.

  5. Visualization of the medial forebrain bundle using diffusion tensor imaging

    PubMed Central

    Hana, Ardian; Hana, Anisa; Dooms, Georges; Boecher-Schwarz, Hans; Hertel, Frank

    2015-01-01

    Diffusion tensor imaging is a technique that enables physicians the portrayal of white matter tracts in vivo. We used this technique in order to depict the medial forebrain bundle (MFB) in 15 consecutive patients between 2012 and 2015. Men and women of all ages were included. There were six women and nine men. The mean age was 58.6 years (39–77). Nine patients were candidates for an eventual deep brain stimulation. Eight of them suffered from Parkinson‘s disease and one had multiple sclerosis. The remaining six patients suffered from different lesions which were situated in the frontal lobe. These were 2 metastasis, 2 meningiomas, 1 cerebral bleeding, and 1 glioblastoma. We used a 3DT1-sequence for the navigation. Furthermore T2- and DTI- sequences were performed. The FOV was 200 × 200 mm2, slice thickness 2 mm, and an acquisition matrix of 96 × 96 yielding nearly isotropic voxels of 2 × 2 × 2 mm. 3-Tesla-MRI was carried out strictly axial using 32 gradient directions and one b0-image. We used Echo-Planar-Imaging (EPI) and ASSET parallel imaging with an acceleration factor of 2. b-value was 800 s/mm2. The maximal angle was 50°. Additional scanning time was < 9 min. We were able to visualize the MFB in 12 of our patients bilaterally and in the remaining three patients we depicted the MFB on one side. It was the contralateral side of the lesion. These were 2 meningiomas and one metastasis. Portrayal of the MFB is possible for everyday routine for neurosurgical interventions. As part of the reward circuitry it might be of substantial importance for neurosurgeons during deep brain stimulation in patients with psychiatric disorders. Surgery in this part of the brain should always take the preservation of this white matter tract into account. PMID:26581828

  6. Medial Temporal Lobe Activity Predicts Successful Relational Memory Binding

    PubMed Central

    Hannula, Deborah E.; Ranganath, Charan

    2009-01-01

    Previous neuropsychological findings have implicated medial temporal lobe (MTL) structures in retaining object-location relations over the course of short delays, but MTL effects have not always been reported in neuroimaging investigations with similar short-term memory requirements. Here, we used event-related functional magnetic resonance imaging to test the hypothesis that the hippocampus and related MTL structures support accurate retention of relational memory representations, even across short delays. On every trial, four objects were presented, each in one of nine possible locations of a three-dimensional grid. Participants were to mentally rotate the grid and then maintain the rotated representation in anticipation of a test stimulus: a rendering of the grid, rotated 90° from the original viewpoint. The test stimulus was either a “match” display, in which object-location relations were intact, or a “mismatch” display, in which one object occupied a new, previously unfilled location (mismatch position), or two objects had swapped locations (mismatch swap). Encoding phase activation in anterior and posterior regions of the left hippocampus, and in bilateral perirhinal cortex, predicted subsequent accuracy on the short-term memory decision, as did bilateral posterior hippocampal activity after the test stimulus. Notably, activation in these posterior hippocampal regions was also sensitive to the degree to which object-location bindings were preserved in the test stimulus; activation was greatest for match displays, followed by mismatch-position displays, and finally mismatch-swap displays. These results indicate that the hippocampus and related MTL structures contribute to successful encoding and retrieval of relational information in visual short-term memory. PMID:18171929

  7. MEG identifies dorsal medial brain activations during sleep.

    PubMed

    Ioannides, Andreas A; Kostopoulos, George K; Liu, Lichan; Fenwick, Peter B C

    2009-01-15

    All sleep stages contain epochs with high-amplitude electrophysiological phasic events, alternating with quieter "core periods." High-amplitude and core state properties cannot be disentangled with PET and fMRI. Here from high temporal resolution magnetoencephalography data, regional changes in neuronal activity were extracted during core periods in different frequency bands for each sleep stage and waking. We found that gamma-band activity increases in precuneus during light sleep (stages 1/2) and in the left dorso-medial prefrontal cortex (L-DMPFC) during deep sleep (stages 3/4). The L-DMPFC activated area expands laterally during rapid eye movement (REM) sleep, into a volume of about 5 cm(3) bounded by regions attributed to Theory of Mind (ToM) and default systems, both involved in introspection. Gamma band activity in this area was higher during REM sleep than other sleep stages and active wakefulness. There is a tantalizing correspondence between increased wide-band activity (dominated by low frequencies) in early non-REM (NREM) sleep stages and increases in gamma-band activity in late NREM and REM periods that we attribute to a lateral disinhibition mechanism. The results provide a description of regional electrophysiological changes in awake state, light and deep sleep, and REM sleep. These changes are most pronounced in the L-DMPFC and the other areas around the dorsal midline that are close to, but do not overlap with areas of the default and ToM systems, suggesting that the DMPFC, particularly in the left hemisphere, plays an important role in late NREM stages, in REM and possibly in dreaming.

  8. ANTIDEPRESSANT EFFECT OF OPTOGENETIC STIMULATION OF THE MEDIAL PREFRONTAL CORTEX

    PubMed Central

    Covington, Herbert E.; Lobo, Mary Kay; Maze, Ian; Vialou, Vincent; Hyman, James M; Zaman, Samir; LaPlant, Quincey; Mouzon, Ezekiel; Ghose, Subroto; Tamminga, Carol A.; Neve, Rachael L.; Deisseroth, Karl; Nestler, Eric J.

    2010-01-01

    Brain stimulation and imaging studies in humans have highlighted a key role for the prefrontal cortex in clinical depression, however, it remains unknown whether excitation or inhibition of prefrontal cortical neuronal activity is associated with antidepressant responses. Here, we examined cellular indicators of functional activity, including the immediate early genes (IEG), zif268 (egr1), c-fos and arc, in the prefrontal cortex of clinically depressed humans obtained postmortem. We also examined these genes in the ventral portion of the medial prefrontal cortex (mPFC) of mice after chronic social defeat stress, a mouse model of depression. In addition, we used viral vectors to overexpress channel rhodopsin 2 (a light-activated cation channel) in mouse mPFC in order to optogenetically drive “burst” patterns of cortical firing in-vivo and examine the behavioral consequences. Prefrontal cortical tissue derived from clinically depressed humans displayed significant reductions in IEG expression, consistent with a deficit in neuronal activity within this brain region. Mice subjected to chronic social defeat stress exhibited similar reductions in levels of IEG expression in mPFC. Interestingly, some of these changes were not observed in defeated mice that escape the deleterious consequences of the stress, i.e., resilient animals. In those mice that expressed a strong depressive-like phenotype, i.e., susceptible animals, optogenetic stimulation of mPFC exerted potent antidepressant-like effects, without affecting general locomotor activity, anxiety-like behaviors, or social memory. These results indicate that the activity of the mPFC is a key determinant of depression-like behavior, as well as antidepressant responses. PMID:21123555

  9. Quantum correlation cost of the weak measurement

    SciTech Connect

    Zhang, Jun; Wu, Shao-xiong; Yu, Chang-shui

    2014-12-15

    Quantum correlation cost (QCC) characterizing how much quantum correlation is used in a weak-measurement process is presented based on the trace norm. It is shown that the QCC is related to the trace-norm-based quantum discord (TQD) by only a factor that is determined by the strength of the weak measurement, so it only catches partial quantumness of a quantum system compared with the TQD. We also find that the residual quantumness can be ‘extracted’ not only by the further von Neumann measurement, but also by a sequence of infinitesimal weak measurements. As an example, we demonstrate our outcomes by the Bell-diagonal state.

  10. Passive limitation of adduction after Cüppers's 'Fadenoperation' on medial recti.

    PubMed Central

    Paliaga, G P; Braga, M

    1989-01-01

    In 40 eyes of 20 esotropic subjects in which a 'Fadenoperation' was performed on the medial recti we measured the resistance to ocular rotation in adduction before and after the operation. The difference between the two sets of force measurements demonstrates that the Fadenoperation on medial recti produces a mechanical restriction to adduction which can explain the effect of the surgical procedure on the strabismic deviation. PMID:2765442

  11. Post traumatic osteoma of tibial insertion of medial collateral ligament of knee joint.

    PubMed

    Shanker, V S; Gadikoppula, S; Loeffler, M D

    1998-03-01

    Two cases are presented of post traumatic para-articular osteoma developing at the site of tibial attachment of the medial collateral ligament of knee joint. These occurred after injuries sustained while playing football and in one case the ossified mass was treated with surgical excision for unresolved symptoms after conservative measures. A comparison is made with Pellegrini Stieda disease, which is a similar affection of the femoral insertion of the medial ligament of the knee joint.

  12. In vivo medial and lateral tibial loads during dynamic and high flexion activities.

    PubMed

    Zhao, Dong; Banks, Scott A; D'Lima, Darryl D; Colwell, Clifford W; Fregly, Benjamin J

    2007-05-01

    Though asymmetric loading between the medial and lateral compartments of total knee replacements may contribute to implant loosening and failure, the in vivo contact force distribution during dynamic daily activities remains unknown. This study reports in vivo medial and lateral contact forces experienced by a well-aligned knee implant for a variety of activities. In vivo implant motion and total axial load data were collected from a single knee replacement patient performing treadmill gait (hands resting on handlebars), step up/down, lunge, and kneel activities. In vivo motion was measured using video fluoroscopy, while in vivo axial loads were collected simultaneously using an instrumented tibial component. An elastic foundation contact model employing linear and nonlinear polyethylene material properties was constructed to calculate medial and lateral contact forces based on the measured kinematics, total axial loads, and centers of pressure. For all activities, the predicted medial and lateral contact forces were insensitive to the selected material model. The percentage of medial to total contact force ranged from 18 to 60 for gait, 47 to 65 for step up/down, and 55 to 60 for kneel and lunge. At maximum load during the motion cycle, medial force was 1.2 BW for gait and 2.0 BW for step up/down, while the corresponding lateral forces were 1.0 and 1.5 BW, respectively. At mean load in the final static pose, medial force was 0.2 BW for kneel and 0.9 BW for lunge, with corresponding lateral forces of 0.1 and 0.7 BW, respectively. For this patient, a constant load split of 55% medial-45% lateral during loaded activity would be a reasonable approximation for these test conditions.

  13. Computed Tomographic Distinction of Intimal and Medial Calcification in the Intracranial Internal Carotid Artery

    PubMed Central

    Vos, Annelotte; Van Hecke, Wim; Vink, Aryan; Bleys, Ronald L. A. W.; Verdoorn, Daphne; Mali, Willem P. Th. M.; Hendrikse, Jeroen; Koek, Huiberdina L.; de Jong, Pim A.; De Vis, Jill B.

    2017-01-01

    Background Intracranial internal carotid artery (iICA) calcification is associated with stroke and is often seen as a proxy of atherosclerosis of the intima. However, it was recently shown that these calcifications are predominantly located in the tunica media and internal elastic lamina (medial calcification). Intimal and medial calcifications are thought to have a different pathogenesis and clinical consequences and can only be distinguished through ex vivo histological analysis. Therefore, our aim was to develop CT scoring method to distinguish intimal and medial iICA calcification in vivo. Methods First, in both iICAs of 16 cerebral autopsy patients the intimal and/or medial calcification area was histologically assessed (142 slides). Brain CT images of these patients were matched to the corresponding histological slides to develop a CT score that determines intimal or medial calcification dominance. Second, performance of the CT score was assessed in these 16 patients. Third, reproducibility was tested in a separate cohort. Results First, CT features of the score were circularity (absent, dot(s), <90°, 90–270° or 270–360°), thickness (absent, ≥1.5mm, or <1.5mm), and morphology (indistinguishable, irregular/patchy or continuous). A high sum of features represented medial and a lower sum intimal calcifications. Second, in the 16 patients the concordance between the CT score and the dominant calcification type was reasonable. Third, the score showed good reproducibility (kappa: 0.72 proportion of agreement: 0.82) between the categories intimal, medial or absent/indistinguishable. Conclusions The developed CT score shows good reproducibility and can differentiate reasonably well between intimal and medial calcification dominance in the iICA, allowing for further (epidemiological) studies on iICA calcification. PMID:28060941

  14. Knee adduction moment and medial contact force--facts about their correlation during gait.

    PubMed

    Kutzner, Ines; Trepczynski, Adam; Heller, Markus O; Bergmann, Georg

    2013-01-01

    The external knee adduction moment is considered a surrogate measure for the medial tibiofemoral contact force and is commonly used to quantify the load reducing effect of orthopedic interventions. However, only limited and controversial data exist about the correlation between adduction moment and medial force. The objective of this study was to examine whether the adduction moment is indeed a strong predictor for the medial force by determining their correlation during gait. Instrumented knee implants with telemetric data transmission were used to measure tibiofemoral contact forces in nine subjects. Gait analyses were performed simultaneously to the joint load measurements. Skeletal kinematics, as well as the ground reaction forces and inertial parameters, were used as inputs in an inverse dynamics approach to calculate the external knee adduction moment. Linear regression analysis was used to analyze the correlation between adduction moment and medial force for the whole stance phase and separately for the early and late stance phase. Whereas only moderate correlations between adduction moment and medial force were observed throughout the whole stance phase (R(2) = 0.56) and during the late stance phase (R(2) = 0.51), a high correlation was observed at the early stance phase (R(2) = 0.76). Furthermore, the adduction moment was highly correlated to the medial force ratio throughout the whole stance phase (R(2) = 0.75). These results suggest that the adduction moment is a surrogate measure, well-suited to predicting the medial force ratio throughout the whole stance phase or medial force during the early stance phase. However, particularly during the late stance phase, moderate correlations and high inter-individual variations revealed that the predictive value of the adduction moment is limited. Further analyses are necessary to examine whether a combination of other kinematic, kinetic or neuromuscular factors may lead to a more reliable

  15. Knee Adduction Moment and Medial Contact Force – Facts about Their Correlation during Gait

    PubMed Central

    Kutzner, Ines; Trepczynski, Adam; Heller, Markus O.; Bergmann, Georg

    2013-01-01

    The external knee adduction moment is considered a surrogate measure for the medial tibiofemoral contact force and is commonly used to quantify the load reducing effect of orthopedic interventions. However, only limited and controversial data exist about the correlation between adduction moment and medial force. The objective of this study was to examine whether the adduction moment is indeed a strong predictor for the medial force by determining their correlation during gait. Instrumented knee implants with telemetric data transmission were used to measure tibiofemoral contact forces in nine subjects. Gait analyses were performed simultaneously to the joint load measurements. Skeletal kinematics, as well as the ground reaction forces and inertial parameters, were used as inputs in an inverse dynamics approach to calculate the external knee adduction moment. Linear regression analysis was used to analyze the correlation between adduction moment and medial force for the whole stance phase and separately for the early and late stance phase. Whereas only moderate correlations between adduction moment and medial force were observed throughout the whole stance phase (R2 = 0.56) and during the late stance phase (R2 = 0.51), a high correlation was observed at the early stance phase (R2 = 0.76). Furthermore, the adduction moment was highly correlated to the medial force ratio throughout the whole stance phase (R2 = 0.75). These results suggest that the adduction moment is a surrogate measure, well-suited to predicting the medial force ratio throughout the whole stance phase or medial force during the early stance phase. However, particularly during the late stance phase, moderate correlations and high inter-individual variations revealed that the predictive value of the adduction moment is limited. Further analyses are necessary to examine whether a combination of other kinematic, kinetic or neuromuscular factors may lead to a more reliable prediction of

  16. Intralaminar and medial thalamic influence on cortical synchrony, information transmission and cognition

    PubMed Central

    Saalmann, Yuri B.

    2014-01-01

    The intralaminar and medial thalamic nuclei are part of the higher-order thalamus, which receives little sensory input, and instead forms extensive cortico-thalamo-cortical pathways. The large mediodorsal thalamic nucleus predominantly connects with the prefrontal cortex, the adjacent intralaminar nuclei connect with fronto-parietal cortex, and the midline thalamic nuclei connect with medial prefrontal cortex and medial temporal lobe. Taking into account this connectivity pattern, it is not surprising that the intralaminar and medial thalamus has been implicated in a variety of cognitive functions, including memory processing, attention and orienting, as well as reward-based behavior. This review addresses how the intralaminar and medial thalamus may regulate information transmission in cortical circuits. A key neural mechanism may involve intralaminar and medial thalamic neurons modulating the degree of synchrony between different groups of cortical neurons according to behavioral demands. Such a thalamic-mediated synchronization mechanism may give rise to large-scale integration of information across multiple cortical circuits, consequently influencing the level of arousal and consciousness. Overall, the growing evidence supports a general role for the higher-order thalamus in the control of cortical information transmission and cognitive processing. PMID:24847225

  17. Differential effects of unilateral lesions in the medial amygdala on spontaneous and induced ovulation.

    PubMed

    Sanchez, M A; Dominguez, R

    1995-01-01

    The possible existence of asymmetry in the control of ovulation by the medial amygdala was explored. Unilateral lesions of the medial amygdala were performed on each day of the estrous cycle. The estral index diminished in almost all animals with a lesion in the right side of medial amygdala. Lesions of the right medial amygdala, when performed on diestrus-1, resulted in a significant decrease in the number of rats ovulating compared to controls (4/8 vs. 8/8, p < 0.05). In ovulating animals a significant reduction in the number of ova shed by the left ovary was found (2.2 +/- 0.8 vs. 6.3 +/- 0.8, p < 0.05). Lesions of the stria terminalis performed on diestrus-1 did not affect ovulation. In a second experiment, administration of GnRH did not restore ovulation in rats with lesions of the right medial amygdala. However, sequential injections of PMSG-hCG did result in ovulation by all members of a group of lesioned animals. In this last condition a significant decrease in the number of ova shed by the right ovary was found compared to animals in the lesion-only condition (1.5 +/- 0.5 vs. 6.0 +/- 1.5, p < 0.05). These data suggest that control of ovulation by the medial amygdala is asymmetric and varies during the estrous cycle.

  18. [Anatomical variants of the medial calcaneal nerve and the Baxter nerve in the tarsal tunnel].

    PubMed

    Martín-Oliva, X; Elgueta-Grillo, J; Veliz-Ayta, P; Orosco-Villaseñor, S; Elgueta-Grillo, M; Viladot-Perice, R

    2013-01-01

    The tarsal tunnel is composed of the posterior border of the medial malleoulus, the posterior aspect of the talus and the medial aspect of the calcaneus. The medial calcaneal nerve emerges from the posterior aspect of the posterior tibial nerve in 75% of cases and from the lateral plantar nerve in the remaining 25%. Finally, the medial calcaneal nerve ends as a single terminal branch in 79% of cases and in numerous terminal branches in the remaining 21%. To describe the anatomical variants of the posterior tibial nerve and its terminal branches. To describe the steps for tarsal tunnel release. To describe Baxter nerve release. The anatomical variants of the posterior tibial nerve and its terminal branches within the tarsal tunnel were studied. Then the Lam technique was performed; it consists of: 1) opening of the laciniate ligament, 2) opening of the fascia over the abductor hallucis muscle, 3) exoneurolysis of the posterior tibial nerve and its terminal branches, identifying the emergence and pathway of the medial calcaneal branch, the lateral plantar nerve and its Baxter nerve branch and the medial plantar nerve. Baxter nerve was found in 100% of cases. In 100% of cases in our series the nerve going to the abductor digiti minimi muscle of the foot was found; 87.5% of cases had two terminal branches. The dissections proved that a crucial step was the release of the distal tarsal tunnel.

  19. Dual role of medial A10 dopamine neurons in affective encoding.

    PubMed

    Liu, Zhong-Hua; Shin, Rick; Ikemoto, Satoshi

    2008-11-01

    Increasing evidence suggests that the activation of medial A10 neurons mediates positive affective encoding. However, little is known about the functions of the inhibition of midbrain dopamine neurons. Here we show evidence suggesting that the inhibition of medial A10 neurons mediates a negative affective state, leading to negative affective encoding, whereas blunting the activation of medial A10 neurons disrupts positive affective encoding involving food reward. We used a microinjection procedure, in which the D(2) dopamine receptor agonist quinpirole was administered into the cell body region of the dopamine neurons, a procedure that reduces dopamine cell firing. Microinjections of quinpirole into the posteromedial ventral tegmental area, but not its more lateral counterparts, led to conditioned place aversion. Quinpirole administration to this site also decreased food intake and basal dopamine concentration in the ventromedial striatum, a major projection area of medial A10 neurons. In addition, moderate quinpirole doses that did not lead to conditioned place aversion or disrupt food intake abolished food-conditioned place preference, suggesting that blunting dopamine impulse activity in response to food reward disrupts positive affective encoding in associated external stimuli. Our data support the hypothesis that activation of medial A10 dopamine neurons mediates a positive affective state, leading to positive affective encoding, while their inhibition mediates a negative affective state, leading to negative affective encoding. Together with previous findings, we propose that medial A10 neurons are an important component of the mechanism via which animals learn to avoid negative incentive stimuli.

  20. Medial epicondylitis in occupational settings: prevalence, incidence and associated risk factors

    PubMed Central

    Descatha, Alexis; Leclerc, Annette; Chastang, Jean-François; Roquelaure, Yves

    2003-01-01

    As medial epicondylitis has not been studied alone, we investigated its links between personal and occupational factors in repetitive work, and its course. 1757 workers were examined by an occupational health physician in 1993–94. 598 of them were re-examined three years later. Prevalence was between 4 and 5%, with annual incidence estimated at 1.5%. Forceful work was a risk factor for medial epicondylitis (OR 1.95 CI [1.15–3.32]), but not exposure to repetitive work (OR 1.11, CI [0.59–2.10]). Workers with medial epicondylitis had a significantly higher prevalence of other work-related upper-limb musculoskeletal disorders (WRMD). Risk factors differed for medial and lateral epicondylitis. The prognosis for medial epicondylitis in this population was good with a three-year recovery rate at 81%. Medial epicondylitis was clearly associated with forceful work and other upper-limb WRMD, and its prognosis was good. PMID:14506342

  1. The JCR:LA-cp rat: a novel rodent model of cystic medial necrosis.

    PubMed

    Pung, Yuh Fen; Chilian, William M; Bennett, Martin R; Figg, Nichola; Kamarulzaman, Mohd Hamzah

    2017-03-01

    Although there are multiple rodent models of the metabolic syndrome, very few develop vascular complications. In contrast, the JCR:LA-cp rat develops both metabolic syndrome and early atherosclerosis in predisposed areas. However, the pathology of the normal vessel wall has not been described. We examined JCR:LA control (+/+) or cp/cp rats fed normal chow diet for 6 or 18 mo. JCR:LA-cp rats developed multiple features of advanced cystic medial necrosis including "cysts," increased collagen formation and proteoglycan deposition around cysts, apoptosis of vascular smooth muscle cells, and spotty medial calcification. These appearances began within 6 mo and were extensive by 18 mo. JCR:LA-cp rats had reduced medial cellularity, increased medial thickness, and vessel hypoxia that was most marked in the adventitia. In conclusion, the normal chow-fed JCR:LA-cp rat represents a novel rodent model of cystic medial necrosis, associated with multiple metabolic abnormalities, vascular smooth muscle cell apoptosis, and vessel hypoxia.NEW & NOTEWORTHY Triggers for cystic medial necrosis (CMN) have been difficult to study due to lack of animal models to recapitulate the pathologies seen in humans. Our study is the first description of CMN in the rat. Thus the JCR:LA-cp rat represents a useful model to investigate the underlying molecular changes leading to the development of CMN.

  2. Anconeus epitrochlearis as a source of medial elbow pain in baseball pitchers.

    PubMed

    Li, Xinning; Dines, Joshua S; Gorman, Matthew; Limpisvasti, Orr; Gambardella, Ralph; Yocum, Lou

    2012-07-01

    Medial elbow pain is reported in 18% to 69% of baseball players aged of 9 and 19 years. This is due to the large valgus stresses focused on the medial side of the elbow during overhead activities. In overhead throwers and pitchers, pain can be attributed to valgus extension overload with resultant posteromedial impingement, overuse of the flexor-pronator musculature resulting in medial epicondylitis, or occasional muscle tears or ruptures. The anconeus epitrochlearis is a known cause of cubital tunnel syndrome and has been postulated as a source of medial elbow pain in overhead athletes. This article describes the cases of 3 right-handed baseball pitchers with persistent right-sided medial elbow pain during throwing despite a prolonged period of rest, physical therapy, and nonsteroidal anti-inflammatory drugs. Two patients had symptoms of cubital tunnel syndrome as diagnosed by electromyogram and nerve conduction studies and the presence of the anconeus epitrochlearis muscle per magnetic resonance imaging. All patients underwent isolated release of the anconeus muscle without ulnar nerve transposition and returned to their previous levels of activity. The diagnosis and treatment of pitchers who present with medial-sided elbow pain can be complex. The differential should include an enlarged or inflamed anconeus epitrochlearis muscle as a possible cause. Conservative management should be the first modality. However, surgical excision with isolated release of the muscle can be successful in returning patients with persistent pain despite a trial of conservative management to their previous levels of function.

  3. Predictors of Visual Outcome Following Surgical Resection of Medial Sphenoid Wing Meningiomas

    PubMed Central

    Chaichana, Kaisorn L.; Jackson, Christopher; Patel, Amar; Miller, Neil R.; Subramanian, Prem; Lim, Michael; Gallia, Gary; Olivi, Alessandro; Weingart, Jon; Brem, Henry; Quiñones-Hinojosa, Alfredo

    2012-01-01

    Objective Medial sphenoid wing meningiomas (SWMs) are relatively common tumors that are associated with significant morbidity and mortality, primarily from their anatomic proximity to many critical neurological and vascular structures. A major complication is visual deterioration. This study aimed to identify predictors of visual outcome following medial SWM resection. Design Retrospective, stepwise multivariate proportional hazards regression analysis. Setting Johns Hopkins Hospital. Participants All patients who underwent medial SWM resection from 1998 to 2009. Main Outcome Measures Visual function. Results Sixty-five medial SWM resections were performed. After multivariate proportional hazards regression analysis, preoperative visual decline (relative risk [RR] 95% confidence interval [CI]; 13.431 [2.601 to 46.077], p = 0.006), subtotal resection (RR [95% CI]; 3.717 [1.204 to 13.889], p = 0.02), and repeat surgery (RR [95% CI]; 5.681 [1.278 to 19.802], p = 0.03) were found to be independent predictors of visual decline at last follow-up. Tumor recurrence and postoperative radiation therapy trended toward, but did not reach statistical significance. Conclusion These findings advocate for early and aggressive surgical intervention for patients with medial SWMs to maximize the likelihood of subsequent visual preservation. This may provide patients and physicians with prognostic information that may guide medical and surgical therapy for patients with medial SWMs. PMID:24083123

  4. Regional divergence of palate medial edge epithelium along the anterior to posterior axis.

    PubMed

    Jin, Jiu-Zhen; Warner, Dennis R; Ding, Jixiang

    2014-01-01

    Recent studies have shown that mouse palatal mesenchymal cells undergo regional specification along the anterior-posterior (A-P) axis defined by anterior Shox2 and Msx1 expression and posterior Meox2 expression. A-P regional specification of the medial edge epithelium, which is directly responsible for palate fusion, has long been proposed, but it has not yet been demonstrated due to the lack of regional specific markers. In this study, we have demonstrated that the palate medial edge epithelium is regionalized along the A-P axis, similar to that for the underlying mesenchyme. Mmp13, a medial edge epithelium specific marker, was uniformly expressed from anterior to posterior in wild-type mouse palatal shelves. Previous studies demonstrated that medial edge epithelium expression of Mmp13 was regulated by TGF-beta3. We have found that the changes in Mmp13 expression in TGF-beta3 knockouts varied along the A-P axis, and can be broken down into three distinct regions. These regions correlated with regional specification of the underlying medial edge mesenchymal cells and timing of palate fusion. Mouse palate medial edge epithelium along the A-P axis can be divided into different regions according to the differential response to the loss of TGF-beta3.

  5. Medial septum lesions disrupt exploratory trip organization: evidence for septohippocampal involvement in dead reckoning.

    PubMed

    Martin, Megan M; Horn, Katharine L; Kusman, Kelly J; Wallace, Douglas G

    2007-02-28

    Rats organize their open field behavior into a series of exploratory trips focused around a central location or home base. In addition, differences in movement kinematics have been used to fractionate the exploratory trip into tour (i.e., sequences of linear movement or progressions punctuated by stops) and homeward (i.e., single progression direct to the home base) segments. The observation of these characteristics independent of environmental familiarity and visual cue availability has suggested a role for self-movement information or dead reckoning in organizing exploratory behavior. Although previous work has implicated a role for the septohippocampal system in dead reckoning based navigation, as of yet, no studies have investigated the contribution of the medial septum to dead reckoning. First, the present study examined the organization of exploratory behavior under dark and light conditions in control rats and rats receiving either electrolytic or sham medial septum lesions. Medial septum lesions produced a significant increase in homeward segment path circuity and variability of temporal pacing of linear speeds. Second, as an independent assessment of the effectiveness of the medial septum lesions, rats were trained to locate a hidden platform in the standard water maze procedure. Consistent with previous research, medial septum lesions attenuated learning the location of the hidden platform. These results demonstrate a role for the medial septum in organizing exploratory behavior and provide further support for the role of the septohippocampal system in dead reckoning based navigation.

  6. Dual Role of Medial A10 Dopamine Neurons in Affective Encoding

    PubMed Central

    Liu, Zhong-Hua; Shin, Rick; Ikemoto, Satoshi

    2008-01-01

    Increasing evidence suggests that the activation of medial A10 neurons mediates positive affective encoding. However, little is known about the functions of the inhibition of midbrain dopamine neurons. Here we show evidence suggesting that the inhibition of medial A10 neurons mediates a negative affective state, leading to negative affective encoding, whereas blunting the activation of medial A10 neurons disrupts positive affective encoding involving food reward. We used a microinjection procedure, in which the D2 dopamine receptor agonist quinpirole was administered into the cell body region of the dopamine neurons, a procedure that reduces dopamine cell firing. Microinjections of quinpirole into the posteromedial ventral tegmental area, but not its more lateral counterparts, led to conditioned place aversion. Quinpirole administration to this site also decreased food intake and basal dopamine concentration in the ventromedial striatum, a major projection area of medial A10 neurons. In addition, moderate quinpirole doses that did not lead to conditioned place aversion or disrupt food intake abolished food-conditioned place preference, suggesting that blunting dopamine impulse activity in response to food reward disrupts positive affective encoding in associated external stimuli. Our data support the hypothesis that activation of medial A10 dopamine neurons mediates a positive affective state, leading to positive affective encoding, while their inhibition mediates a negative affective state, leading to negative affective encoding. Together with previous findings, we propose that medial A10 neurons are an important component of the mechanism via which animals learn to avoid negative incentive stimuli. PMID:18256592

  7. Sensitivity of medial and lateral knee contact force predictions to frontal plane alignment and contact locations.

    PubMed

    Saliba, Christopher M; Brandon, Scott C E; Deluzio, Kevin J

    2017-03-12

    Musculoskeletal models are increasingly used to estimate medial and lateral knee contact forces, which are difficult to measure in vivo. The sensitivity of contact force predictions to modeling parameters is important to the interpretation and implication of results generated by the model. The purpose of this study was to quantify the sensitivity of knee contact force predictions to simultaneous errors in frontal plane knee alignment and contact locations under different dynamic conditions. We scaled a generic musculoskeletal model for N=23 subjects' stature and radiographic knee alignment, then perturbed frontal plane alignment and mediolateral contact locations within experimentally-possible ranges of 10° to -10° and 10 to -10mm, respectively. The sensitivity of first peak, second peak, and mean medial and lateral knee contact forces to knee adduction angle and contact locations was modeled using linear regression. Medial loads increased, and lateral loads decreased, by between 3% and 6% bodyweight for each degree of varus perturbation. Shifting the medial contact point medially increased medial loads and decreased lateral loads by between 1% and 4% bodyweight per millimeter. This study demonstrates that realistic measurement errors of 5mm (contact distance) or 5° (frontal plane alignment) could result in a combined 50% BW error in subject specific contact force estimates. We also show that model sensitivity varies between subjects as a result of differences in gait dynamics. These results demonstrate that predicted knee joint contact forces should be considered as a range of possible values determined by model uncertainty.

  8. Sodium in weak G-band giants

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy J.; Lambert, David L.

    1994-01-01

    Sodium abundances have been determined for eight weak G-band giants whose atmospheres are greatly enriched with products of the CN-cycling H-burning reactions. Systematic errors are minimized by comparing the weak G-band giants to a sample of similar but normal giants. If, further, Ca is selected as a reference element, model atmosphere-related errors should largely be removed. For the weak-G-band stars (Na/Ca) = 0.16 +/- 0.01, which is just possibly greater than the result (Na/Ca) = 0.10 /- 0.03 from the normal giants. This result demonstrates that the atmospheres of the weak G-band giants are not seriously contaminated with products of ON cycling.

  9. Reversing entanglement change by a weak measurement

    SciTech Connect

    Sun Qingqing; Zubairy, M. Suhail; Al-Amri, M.; Davidovich, Luiz

    2010-11-15

    Entanglement of a system changes due to interactions with the environment. A typical type of interaction is amplitude damping. If we add a detector to monitor the environment and only select the no-damping outcome, this amplitude damping is modified into a weak measurement. Here we show that the entanglement change of a two-qubit state due to amplitude damping or weak measurement can be probabilistically reversed. For the amplitude-damping case, the entanglement partially recovers under most conditions. For the weak-measurement case, the recovery of the initial entangled state is exact. The reversal procedure involves another weak measurement, preceded and followed by bit flips applied to both qubits. We propose a linear optics scheme for the experimental demonstration of these procedures.

  10. Elastic scattering with weakly bound projectiles

    SciTech Connect

    Figueira, J. M.; Abriola, D.; Arazi, A.; Capurro, O. A.; Marti, G. V.; Martinez Heinmann, D.; Pacheco, A. J.; Testoni, J. E.; Barbara, E. de; Fernandez Niello, J. O.; Padron, I.; Gomes, P. R. S.; Lubian, J.

    2007-02-12

    Possible effects of the break-up channel on the elastic scattering threshold anomaly has been investigated. We used the weakly bound 6,7Li nuclei, which is known to undergo break-up, as projectiles in order to study the elastic scattering on a 27Al target. In this contribution we present preliminary results of these experiments, which were analyzed in terms of the Optical Model and compared with other elastic scattering data using weakly bound nuclei as projectile.

  11. The effects of neuromuscular exercise on medial knee joint load post-arthroscopic partial medial meniscectomy: ‘SCOPEX’ a randomised control trial protocol

    PubMed Central

    2012-01-01

    Background Meniscectomy is a risk factor for knee osteoarthritis, with increased medial joint loading a likely contributor to the development and progression of knee osteoarthritis in this group. Therefore, post-surgical rehabilitation or interventions that reduce medial knee joint loading have the potential to reduce the risk of developing or progressing osteoarthritis. The primary purpose of this randomised, assessor-blind controlled trial is to determine the effects of a home-based, physiotherapist-supervised neuromuscular exercise program on medial knee joint load during functional tasks in people who have recently undergone a partial medial meniscectomy. Methods/design 62 people aged 30–50 years who have undergone an arthroscopic partial medial meniscectomy within the previous 3 to 12 months will be recruited and randomly assigned to a neuromuscular exercise or control group using concealed allocation. The neuromuscular exercise group will attend 8 supervised exercise sessions with a physiotherapist and will perform 6 exercises at home, at least 3 times per week for 12 weeks. The control group will not receive the neuromuscular training program. Blinded assessment will be performed at baseline and immediately following the 12-week intervention. The primary outcomes are change in the peak external knee adduction moment measured by 3-dimensional analysis during normal paced walking and one-leg rise. Secondary outcomes include the change in peak external knee adduction moment during fast pace walking and one-leg hop and change in the knee adduction moment impulse during walking, one-leg rise and one-leg hop, knee and hip muscle strength, electromyographic muscle activation patterns, objective measures of physical function, as well as self-reported measures of physical function and symptoms and additional biomechanical parameters. Discussion The findings from this trial will provide evidence regarding the effect of a home-based, physiotherapist

  12. Enhancing QKD security with weak measurements

    NASA Astrophysics Data System (ADS)

    Farinholt, Jacob M.; Troupe, James E.

    2016-10-01

    Publisher's Note: This paper, originally published on 10/24/2016, was replaced with a corrected/revised version on 11/8/2016. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance. In the late 1980s, Aharonov and colleagues developed the notion of a weak measurement of a quantum observable that does not appreciably disturb the system.1, 2 The measurement results are conditioned on both the pre-selected and post-selected state of the quantum system. While any one measurement reveals very little information, by making the same measurement on a large ensemble of identically prepared pre- and post-selected (PPS) states and averaging the results, one may obtain what is known as the weak value of the observable with respect to that PPS ensemble. Recently, weak measurements have been proposed as a method of assessing the security of QKD in the well-known BB84 protocol.3 This weak value augmented QKD protocol (WV-QKD) works by additionally requiring the receiver, Bob, to make a weak measurement of a particular observable prior to his strong measurement. For the subset of measurement results in which Alice and Bob's measurement bases do not agree, the weak measurement results can be used to detect any attempt by an eavesdropper, Eve, to correlate her measurement results with Bob's. Furthermore, the well-known detector blinding attacks, which are known to perfectly correlate Eve's results with Bob's without being caught by conventional BB84 implementations, actually make the eavesdropper more visible in the new WV-QKD protocol. In this paper, we will introduce the WV-QKD protocol and discuss its generalization to the 6-state single qubit protocol. We will discuss the types of weak measurements that are optimal for this protocol, and compare the predicted performance of the 6- and 4-state WV-QKD protocols.

  13. PHYSICAL THERAPY INTERVENTION FOR MEDIAL PATELLOFEMORAL LIGAMENT RECONSTRUCTION AFTER REPEATED LATERAL PATELLAR SUBLUXATION/DISLOCATION

    PubMed Central

    Mooney, Brianne; Vitale, Ashley; Apergis, Demitra; Wirth, Stephen; Grossman, Mark G.

    2016-01-01

    ABSTRACT Background The incidence of patellar subluxation or dislocation has been documented up to 43/100,000 with females more prevalent then males. There are many contributing factors involving the hip, knee, and ankle that lead to patellar subluxation. A patellar position of lateral tilt with lateral glide may indicate weakness of the vastus medialis oblique (VMO) and adductors, increased tightness in the iliotibial band, and overpowering of the vastus lateralis. Patella alta can predispose an individual to lateral dislocation due to the patella placement outside of the femoral trochlear groove with a disadvantage of boney stability. Other factors that may cause the patella to laterally sublux or dislocate during a functional activity or sporting activity include a position of femoral external rotation, tibial internal rotation, and excessive contraction of the vastus lateralis. The medial patellofemoral ligament (MPFL) aids in the prevention of a lateral patellar subluxation or dislocation. In cases where there is recurrent subluxation/dislocation and Magnetic Resonance Imaging confirms a MPFL tear, a reconstruction may be the treatment of choice. Purpose The purpose of this case series is to describe the post-surgical physical therapy management of MPFL reconstructions, outcomes using the Modified Cincinnati Knee Outcome Measure (MCKOM) and to propose staged physical therapy interventions for this pathology in the form of a treatment progression. Methods Post-operative management data and outcomes were retrospectively collected using a detailed chart review methodology from seven subjects who underwent MPFL reconstruction. Findings The Modified Cincinnati Knee Outcome Measure (MCKOM) was analyzed for each participant in four sections that were most important to the return and maintenance of participation in sport. At follow-up the mean scores for the seven subjects in Section 3 (instability) was 19.3/20, Section 4 (overall activity level) was 17.3/20, Section

  14. Knee adduction moment relates to medial femoral and tibial cartilage morphology in clinical knee osteoarthritis.

    PubMed

    Maly, Monica R; Acker, Stacey M; Totterman, Saara; Tamez-Peña, José; Stratford, Paul W; Callaghan, Jack P; Adachi, Jonathan D; Beattie, Karen A

    2015-09-18

    The objective was to determine the extent to which the external peak knee adduction moment (KAM) and cumulative knee adductor load explained variation in medial cartilage morphology of the tibia and femur in knee osteoarthritis (OA). Sixty-two adults with clinical knee OA participated (61.5 ± 6.2 years). To determine KAM, inverse dynamics was applied to motion and force data of walking. Cumulative knee adductor load reflected KAM impulse and loading frequency. Loading frequency was captured from an accelerometer. Magnetic resonance imaging scans were acquired with a coronal fat-saturated sequence using a 1.0 T peripheral scanner. Scans were segmented for medial cartilage volume, surface area of the bone-cartilage interface, and thickness. Forward linear regressions assessed the relationship of loading variables with cartilage morphology unadjusted, then adjusted for covariates. In the medial tibia, age and peak KAM explained 20.5% of variance in mean cartilage thickness (p<0.001). Peak KAM alone explained 12.3% of the 5th percentile of medial tibial cartilage thickness (i.e., thinnest cartilage region) (p=0.003). In the medial femur, sex, BMI, age, and peak KAM explained 44% of variance in mean cartilage thickness, with peak KAM contributing 7.9% (p<0.001). 20.7% of variance in the 5th percentile of medial femoral cartilage thickness was explained by BMI and peak KAM (p=0.001). In these models, older age, female sex, greater BMI, and greater peak KAM related with thinner cartilage. Models of KAM impulse produced similar results. In knee OA, KAM peak and impulse, but not loading frequency, were associated with cartilage thickness of the medial tibia and femur.

  15. How Tibiofemoral Alignment and Contact Locations Affect Predictions of Medial and Lateral Tibiofemoral Contact Forces

    PubMed Central

    Lerner, Zachary F.; DeMers, Matthew S.; Delp, Scott L.; Browning, Raymond C.

    2015-01-01

    Understanding degeneration of biological and prosthetic knee joints requires knowledge of the in-vivo loading environment during activities of daily living. Musculoskeletal models can estimate medial/lateral tibiofemoral compartment contact forces, yet anthropometric differences between individuals make accurate predictions challenging. We developed a full-body OpenSim musculoskeletal model with a knee joint that incorporates subject-specific tibiofemoral alignment (i.e. knee varus-valgus) and geometry (i.e. contact locations). We tested the accuracy of our model and determined the importance of these subject-specific parameters by comparing estimated to measured medial and lateral contact forces during walking in an individual with an instrumented knee replacement and post-operative genu valgum (6°). The errors in the predictions of the first peak medial and lateral contact force were 12.4% and 11.9%, respectively, for a model with subject-specific tibiofemoral alignment and contact locations determined via radiographic analysis, vs. 63.1% and 42.0%, respectively, for a model with generic parameters. We found that each degree of tibiofemoral alignment deviation altered the first peak medial compartment contact force by 51N (r2=0.99), while each millimeter of medial-lateral translation of the compartment contact point locations altered the first peak medial compartment contact force by 41N (r2=0.99). The model, available at www.simtk.org/home/med-lat-knee/, enables the specification of subject-specific joint alignment and compartment contact locations to more accurately estimate medial and lateral tibiofemoral contact forces in individuals with non-neutral alignment. PMID:25595425

  16. Forebrain medial septum region facilitates nociception in a rat formalin model of inflammatory pain.

    PubMed

    Lee, Andy Thiam-Huat; Ariffin, Mohammed Zacky; Zhou, Mingyi; Ye, Jenn Zhou; Moochhala, Shabbir M; Khanna, Sanjay

    2011-11-01

    The medial septum is anatomically and functionally linked to the hippocampus, a region implicated in nociception. However, the role of medial septum in nociception remains unclear. To investigate the role of the region in nociception in rats, muscimol, a GABA agonist, or zolpidem, a positive allosteric modulator of GABA(A) receptors, was microinjected into medial septum to attenuate the activity of neurons in the region. Electrophysiological studies in anesthetized rats indicated that muscimol evoked a stronger and longer-lasting suppression of medial septal-mediated activation of hippocampal theta field activity than zolpidem. Similarly, microinjection of muscimol (1 or 2 μg/0.5 μl) into the medial septum of awake rats suppressed both licking and flinching behaviors in the formalin test of inflammatory pain, whereas only the latter behavior was affected by zolpidem (8 or 12 μg/0.5 μl) administered into the medial septum. Interestingly, both drugs selectively attenuated nociceptive behaviors in the second phase of the formalin test that are partly driven by central plasticity. Indeed, muscimol reduced the second phase behaviors by 30% to 60%, which was comparable to the reduction seen with systemic administration of a moderate dose of the analgesic morphine. The reduction was accompanied by a decrease in formalin-induced expression of spinal c-Fos protein that serves as an index of spinal nociceptive processing. The drug effects on nociceptive behaviors were without overt sedation and were distinct from the effects observed after septal lateral microinjections. Taken together, these findings suggest that the activation of medial septum is pro-nociceptive and facilitates aspects of central neural processing underlying nociception.

  17. Functional specialization of medial auditory belt cortex in the alert rhesus monkey.

    PubMed

    Kusmierek, Pawel; Rauschecker, Josef P

    2009-09-01

    Responses of neural units in two areas of the medial auditory belt (middle medial area [MM] and rostral medial area [RM]) were tested with tones, noise bursts, monkey calls (MC), and environmental sounds (ES) in microelectrode recordings from two alert rhesus monkeys. For comparison, recordings were also performed from two core areas (primary auditory area [A1] and rostral area [R]) of the auditory cortex. All four fields showed cochleotopic organization, with best (center) frequency [BF(c)] gradients running in opposite directions in A1 and MM than in R and RM. The medial belt was characterized by a stronger preference for band-pass noise than for pure tones found medially to the core areas. Response latencies were shorter for the two more posterior (middle) areas MM and A1 than for the two rostral areas R and RM, reaching values as low as 6 ms for high BF(c) in MM and A1, and strongly depended on BF(c). The medial belt areas exhibited a higher selectivity to all stimuli, in particular to noise bursts, than the core areas. An increased selectivity to tones and noise bursts was also found in the anterior fields; the opposite was true for highly temporally modulated ES. Analysis of the structure of neural responses revealed that neurons were driven by low-level acoustic features in all fields. Thus medial belt areas RM and MM have to be considered early stages of auditory cortical processing. The anteroposterior difference in temporal processing indices suggests that R and RM may belong to a different hierarchical level or a different computational network than A1 and MM.

  18. A Modified Posterolateral Approach for Radiofrequency Denervation of the Medial Branch of the Cervical Segmental Nerve in Cervical Facet Joint Pain Based on Anatomical Considerations.

    PubMed

    van Eerd, Maarten; Lataster, Arno; Sommer, Micha; Patijn, Jacob; van Kleef, Maarten

    2016-10-13

    The cervical facet joints, also called the zygapophyseal joints, are a potential source of neck pain (cervical facet joint pain). The cervical facet joints are innervated by the cervical medial branches (CMBs) of the cervical segmental nerves. Cervical facet joint pain has been shown to respond to multisegmental radiofrequency denervation of the cervical medial branches. This procedure is performed under fluoroscopic guidance. Currently, three approaches are described and used. Those three techniques of radiofrequency treatment of the CMBs, classified on the base of the needle trajectory toward the anatomical planes, are as follows: the posterolateral technique, the posterior technique, and the lateral technique. We describe the three techniques with their advantages and disadvantages. Anatomical studies providing a topographic anatomy of the course of the CMBs are reviewed. We developed a novel approach based on the observed strengths and weaknesses of the three currently used approaches and based on recent anatomical findings. With this fluoroscopic-guided approach, there is always bone (the facet column) in front of the needle, which makes it safer, and the insertion point is easier to determine without the risk of positioning the radiofrequency needle too dorsally.

  19. Weak crystallization theory of metallic alloys

    NASA Astrophysics Data System (ADS)

    Martin, Ivar; Gopalakrishnan, Sarang; Demler, Eugene A.

    2016-06-01

    Crystallization is one of the most familiar, but hardest to analyze, phase transitions. The principal reason is that crystallization typically occurs via a strongly first-order phase transition, and thus rigorous treatment would require comparing energies of an infinite number of possible crystalline states with the energy of liquid. A great simplification occurs when crystallization transition happens to be weakly first order. In this case, weak crystallization theory, based on unbiased Ginzburg-Landau expansion, can be applied. Even beyond its strict range of validity, it has been a useful qualitative tool for understanding crystallization. In its standard form, however, weak crystallization theory cannot explain the existence of a majority of observed crystalline and quasicrystalline states. Here we extend the weak crystallization theory to the case of metallic alloys. We identify a singular effect of itinerant electrons on the form of weak crystallization free energy. It is geometric in nature, generating strong dependence of free energy on the angles between ordering wave vectors of ionic density. That leads to stabilization of fcc, rhombohedral, and icosahedral quasicrystalline (iQC) phases, which are absent in the generic theory with only local interactions. As an application, we find the condition for stability of iQC that is consistent with the Hume-Rothery rules known empirically for the majority of stable iQC; namely, the length of the primary Bragg-peak wave vector is approximately equal to the diameter of the Fermi sphere.

  20. Experimental noiseless linear amplification using weak measurements

    NASA Astrophysics Data System (ADS)

    Ho, Joseph; Boston, Allen; Palsson, Matthew; Pryde, Geoff

    2016-09-01

    The viability of quantum communication schemes rely on sending quantum states of light over long distances. However, transmission loss can degrade the signal strength, adding noise. Heralded noiseless amplification of a quantum signal can provide a solution by enabling longer direct transmission distances and by enabling entanglement distillation. The central idea of heralded noiseless amplification—a conditional modification of the probability distribution over photon number of an optical quantum state—is suggestive of a parallel with weak measurement: in a weak measurement, learning partial information about an observable leads to a conditional back-action of a commensurate size. Here we experimentally investigate the application of weak, or variable-strength, measurements to the task of heralded amplification, by using a quantum logic gate to weakly couple a small single-optical-mode quantum state (the signal) to an ancilla photon (the meter). The weak measurement is carried out by choosing the measurement basis of the meter photon and, by conditioning on the meter outcomes, the signal is amplified. We characterise the gain of the amplifier as a function of the measurement strength, and use interferometric methods to show that the operation preserves the coherence of the signal.

  1. Weak turbulence theory for reactive instability

    SciTech Connect

    Yoon, P. H.

    2010-11-15

    In the present paper, the customary weak turbulence theory is generalized to include reactive instabilities. For the sake of simplicity, the formalism assumes electrostatic perturbation propagating in one-dimensional uniform unmagnetized plasmas. By weak turbulence theory it is meant as the perturbative nonlinear theory based upon Vlasov equation, truncated at the second (or up to third) order nonlinearity and ensemble averaged. By reactive instability it is meant as the plasma instability whose growth rate is not necessarily exceedingly small. The traditional weak turbulence theory found in the literature is applicable only to weakly growing plasma instabilities whose real frequency {omega}{sub k} can be determined from the real part of the dispersion relation, Re {epsilon}(k,{omega}{sub k})=0, while the growth rate may be determined by the Landau formula, {gamma}{sub k}=-Im {epsilon}(k,{omega}{sub k})[{partial_derivative} Re {epsilon}(k,{omega}{sub k})/{partial_derivative}{omega}{sub k}]{sup -1}. This implies the assumption that |{gamma}{sub k}|<<{omega}{sub k}. On the other hand, for reactive instabilities for which {gamma}{sub k}/{omega}{sub k} is not necessarily small, the real frequency and growth/damping rate must be determined from the complex roots of the dispersion relation, {epsilon}(k,{omega}{sub k}+i{gamma}{sub k})=0. The present paper extends the textbook weak turbulence theory to deal with such a situation.

  2. Disturbance in weak measurements and the difference between quantum and classical weak values

    NASA Astrophysics Data System (ADS)

    Ipsen, Asger C.

    2015-06-01

    The role of measurement-induced disturbance in weak measurements is of central importance for the interpretation of the weak value. Uncontrolled disturbance can interfere with the postselection process and make the weak value dependent on the details of the measurement process. Here we develop the concept of a generalized weak measurement for classical and quantum mechanics. The two cases appear remarkably similar, but we point out some important differences. A priori it is not clear what the correct notion of disturbance should be in the context of weak measurements. We consider three different notions and get three different results: (1) For a "strong" definition of disturbance, we find that weak measurements are disturbing. (2) For a weaker definition we find that a general class of weak measurements is nondisturbing, but that one gets weak values which depend on the measurement process. (3) Finally, with respect to an operational definition of the "degree of disturbance," we find that the AAV weak measurements are the least disturbing, but that the disturbance is always nonzero.

  3. Intraoperative medial pivot affects deep knee flexion angle and patient-reported outcomes after total knee arthroplasty.

    PubMed

    Nishio, Yusuke; Onodera, Tomohiro; Kasahara, Yasuhiko; Takahashi, Daisuke; Iwasaki, Norimasa; Majima, Tokifumi

    2014-04-01

    The aim of this study was to evaluate the relationship between clinical results including patient-reported outcomes and intraoperative knee kinematic patterns after total knee arthroplasty (TKA). A cross-sectional survey of forty consecutive medial osteoarthritis patients who had a primary TKA using a CT-based navigation system was conducted. Subjects were divided into two groups based on intraoperative kinematic patterns: a medial pivot group (n = 20) and a non-medial pivot group (n = 20). Subjective outcomes with the new Knee Society Score and clinical outcomes were evaluated. The functional activities, patient satisfaction and the knee flexion angle of the medial pivot group were significantly better than those of the non-medial pivot group. An intraoperative medial pivot pattern positively influences deep knee flexion and patient-reported outcomes.

  4. Abnormal isokinetic time-to-peak torque of the medial rotators of the shoulder in subjects with impingement syndrome.

    PubMed

    Mattiello-Rosa, Stela M; Camargo, Paula R; Santos, Alexandre A S; Pádua, Michelle; Reiff, Rodrigo B M; Salvini, Tania F

    2008-01-01

    The time-to-peak torque (TPT) and the peak torque ratio of the lateral to medial rotators (LR/MR) during isokinetic lateral and medial rotation of the shoulder were evaluated in patients with shoulder impingement and in healthy subjects. Fifteen patients with shoulder impingement on the dominant side and 9 healthy subjects were evaluated. TPT and LR/MR were measured bilaterally during isokinetic concentric lateral and medial rotation at 60 degrees/s and 180 degrees/s. The impingement group showed a bilateral decrease in the TPT during medial rotation for both 60 degrees/s and 180 degrees/s. No differences were found in the LR/MR between the groups. It is proposed that decreased (TPT) of the medial rotators can be used as a tool for early detection of shoulder impingement. Notably, the decreased time-to-peak torque of the medial rotators may occur before the alteration in the peak torque ratio.

  5. Continuously Varying Critical Exponents Beyond Weak Universality

    PubMed Central

    Khan, N.; Sarkar, P.; Midya, A.; Mandal, P.; Mohanty, P. K.

    2017-01-01

    Renormalization group theory does not restrict the form of continuous variation of critical exponents which occurs in presence of a marginal operator. However, the continuous variation of critical exponents, observed in different contexts, usually follows a weak universality scenario where some of the exponents (e.g., β, γ, ν) vary keeping others (e.g., δ, η) fixed. Here we report ferromagnetic phase transition in (Sm1−yNdy)0.52Sr0.48MnO3 (0.5 ≤ y ≤ 1) single crystals where all three exponents β, γ, δ vary with Nd concentration y. Such a variation clearly violates both universality and weak universality hypothesis. We propose a new scaling theory that explains the present experimental results, reduces to the weak universality as a special case, and provides a generic route leading to continuous variation of critical exponents and multi-criticality. PMID:28327622

  6. Continuously Varying Critical Exponents Beyond Weak Universality

    NASA Astrophysics Data System (ADS)

    Khan, N.; Sarkar, P.; Midya, A.; Mandal, P.; Mohanty, P. K.

    2017-03-01

    Renormalization group theory does not restrict the form of continuous variation of critical exponents which occurs in presence of a marginal operator. However, the continuous variation of critical exponents, observed in different contexts, usually follows a weak universality scenario where some of the exponents (e.g., β, γ, ν) vary keeping others (e.g., δ, η) fixed. Here we report ferromagnetic phase transition in (Sm1‑yNdy)0.52Sr0.48MnO3 (0.5 ≤ y ≤ 1) single crystals where all three exponents β, γ, δ vary with Nd concentration y. Such a variation clearly violates both universality and weak universality hypothesis. We propose a new scaling theory that explains the present experimental results, reduces to the weak universality as a special case, and provides a generic route leading to continuous variation of critical exponents and multi-criticality.

  7. Phase slips in superconducting weak links

    SciTech Connect

    Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.

    2017-01-01

    Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires and slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.

  8. Weak Acid Ionization Constants and the Determination of Weak Acid-Weak Base Reaction Equilibrium Constants in the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Nyasulu, Frazier; McMills, Lauren; Barlag, Rebecca

    2013-01-01

    A laboratory to determine the equilibrium constants of weak acid negative weak base reactions is described. The equilibrium constants of component reactions when multiplied together equal the numerical value of the equilibrium constant of the summative reaction. The component reactions are weak acid ionization reactions, weak base hydrolysis…

  9. Precision cosmology with weak gravitational lensing

    NASA Astrophysics Data System (ADS)

    Hearin, Andrew P.

    In recent years, cosmological science has developed a highly predictive model for the universe on large scales that is in quantitative agreement with a wide range of astronomical observations. While the number and diversity of successes of this model provide great confidence that our general picture of cosmology is correct, numerous puzzles remain. In this dissertation, I analyze the potential of planned and near future galaxy surveys to provide new understanding of several unanswered questions in cosmology, and address some of the leading challenges to this observational program. In particular, I study an emerging technique called cosmic shear, the weak gravitational lensing produced by large scale structure. I focus on developing strategies to optimally use the cosmic shear signal observed in galaxy imaging surveys to uncover the physics of dark energy and the early universe. In chapter 1 I give an overview of a few unsolved mysteries in cosmology and I motivate weak lensing as a cosmological probe. I discuss the use of weak lensing as a test of general relativity in chapter 2 and assess the threat to such tests presented by our uncertainty in the physics of galaxy formation. Interpreting the cosmic shear signal requires knowledge of the redshift distribution of the lensed galaxies. This redshift distribution will be significantly uncertain since it must be determined photometrically. In chapter 3 I investigate the influence of photometric redshift errors on our ability to constrain dark energy models with weak lensing. The ability to study dark energy with cosmic shear is also limited by the imprecision in our understanding of the physics of gravitational collapse. In chapter 4 I present the stringent calibration requirements on this source of uncertainty. I study the potential of weak lensing to resolve a debate over a long-standing anomaly in CMB measurements in chapter 5. Finally, in chapter 6 I summarize my findings and conclude with a brief discussion of my

  10. Extrapolating Weak Selection in Evolutionary Games

    PubMed Central

    Wu, Bin; García, Julián; Hauert, Christoph; Traulsen, Arne

    2013-01-01

    In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By “qualitatively valid” we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more) strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies . In particular, rank changes are almost certain for , which jeopardizes the predictive power of results derived for weak selection. PMID:24339769

  11. TopMaker: Technique Developed for Automatic Multiblock Topology Generation Using the Medial Axis

    NASA Technical Reports Server (NTRS)

    Rigby, David L.

    2004-01-01

    The TopMaker technique was developed in an effort to reduce the time required for grid generation in complex numerical studies. Topology generation accounts for much of the man-hours required for structured multiblock grids. With regard to structured multiblock grids, topology refers to how the blocks are arranged and connected. A two-dimensional multiblock topology generation technique has been developed at the NASA Glenn Research Center. Very general configurations can be addressed by the technique. A configuration is defined by a collection of non-intersecting closed curves, which will be referred to as loops. More than a single loop implies that holes exist in the domain, which poses no problem. This technique requires only the medial vertices and the touch points that define each vertex. From the information about the medial vertices, the connectivity between medial vertices is generated. The physical shape of the medial edge is not required. By applying a few simple rules to each medial edge, a multiblock topology can be generated without user intervention. The resulting topologies contain only the level of complexity dictated by the configurations. Grid lines remain attached to the boundary except at sharp concave turns, where a change in index family is introduced as would be desired. Keeping grid lines attached to the boundary is especially important in computational fluid dynamics, where highly clustered grids are used near no-slip boundaries. This technique is simple and robust and can easily be incorporated into the overall grid-generation process.

  12. Bipartite medial cuneiform: new frequencies from skeletal collections and a meta-analysis of previous cases.

    PubMed

    Burnett, S E; Case, D T

    2011-04-01

    Bipartition of the medial cuneiform is a malsegmentation defect of the foot characterized by separation of the normal cuneiform into dorsal and plantar segments. In many cases, these segments are held together by means of a cartilaginous or fibrocartilaginous bridge, resulting in a deep, lytic-like pit in dry bone reminiscent of those seen in cases of non-osseous tarsal coalition. Partial bipartition, where separation of the two segments is incomplete, may also occur. Though originally documented over 250 years ago, relatively little is known about the bipartite medial cuneiform. The purpose of this paper is to present thirteen new cases (ten complete, three partial) from Egypt, England, South Africa, Denmark, and the United States, and to analyze all known cases to investigate patterns in sex, laterality, frequency, and associated anomalies. Results suggest that bipartite medial cuneiforms are significantly more prevalent in males. Bipartite medial cuneiforms are also frequently bilateral, perhaps indicating a strong genetic component. Identification of this condition in multiple individuals from a cemetery could, therefore, suggest a familial relationship. Frequencies of this variant are consistently less than 1% in most large samples, and significant frequency differences among samples from around the world are rare. Several other minor congenital variations have been noted in individuals with bipartition of the medial cuneiform. However, additional systematic research is needed to elucidate further the prevalence of associated variants.

  13. TopMaker: A Technique for Automatic Multi-Block Topology Generation Using the Medial Axis

    NASA Technical Reports Server (NTRS)

    Heidmann, James D. (Technical Monitor); Rigby, David L.

    2004-01-01

    A two-dimensional multi-block topology generation technique has been developed. Very general configurations are addressable by the technique. A configuration is defined by a collection of non-intersecting closed curves, which will be referred to as loops. More than a single loop implies that holes exist in the domain, which poses no problem. This technique requires only the medial vertices and the touch points that define each vertex. From the information about the medial vertices, the connectivity between medial vertices is generated. The physical shape of the medial edge is not required. By applying a few simple rules to each medial edge, the multiblock topology is generated with no user intervention required. The resulting topologies contain only the level of complexity dictated by the configurations. Grid lines remain attached to the boundary except at sharp concave turns where a change in index family is introduced as would be desired. Keeping grid lines attached to the boundary is especially important in the area of computational fluid dynamics where highly clustered grids are used near no-slip boundaries. This technique is simple and robust and can easily be incorporated into the overall grid generation process.

  14. Voltage dependence of subthreshold resonance frequency in layer II of medial entorhinal cortex.

    PubMed

    Shay, Christopher F; Boardman, Ian S; James, Nicholas M; Hasselmo, Michael E

    2012-08-01

    The resonance properties of individual neurons in entorhinal cortex (EC) may contribute to their functional properties in awake, behaving rats. Models propose that entorhinal grid cells could arise from shifts in the intrinsic frequency of neurons caused by changes in membrane potential owing to depolarizing input from neurons coding velocity. To test for potential changes in intrinsic frequency, we measured the resonance properties of neurons at different membrane potentials in neurons in medial and lateral EC. In medial entorhinal neurons, the resonant frequency of individual neurons decreased in a linear manner as the membrane potential was depolarized between -70 and -55 mV. At more hyperpolarized membrane potentials, cells asymptotically approached a maximum resonance frequency. Consistent with the previous studies, near resting potential, the cells of the medial EC possessed a decreasing gradient of resonance frequency along the dorsal to ventral axis, and cells of the lateral EC lacked resonant properties, regardless of membrane potential or position along the medial to lateral axis within lateral EC. Application of 10 μM ZD7288, the H-channel blocker, abolished all resonant properties in MEC cells, and resulted in physiological properties very similar to lateral EC cells. These results on resonant properties show a clear change in frequency response with depolarization that could contribute to the generation of grid cell firing properties in the medial EC.

  15. Effect of center of pressure modulation on knee adduction moment in medial compartment knee osteoarthritis.

    PubMed

    Haim, Amir; Wolf, Alon; Rubin, Guy; Genis, Yulya; Khoury, Mona; Rozen, Nimrod

    2011-11-01

    The knee adduction moment (KAM) provides a major contribution to the elevated load in the medial compartment of the knee. An abnormally high KAM has been linked with the progression of knee osteoarthritis (OA). Footwear-generated biomechanical manipulations reduce the magnitude of this moment by conveying a more laterally shifted trajectory of the foot's center of pressure (COP), reducing the distance between the ground reaction force and the center of the knee joint, thus lowering the magnitude of the torque. We sought to examine the outcome of a COP shift in a cohort of female patients suffering from medial knee OA. Twenty-two female patients suffering from medial compartment knee OA underwent successive gait analysis testing and direct pedobarographic examination of the COP trajectory with a foot-worn biomechanical device allowing controlled manipulation of the COP. Modulation of the COP coronal trajectory from medial to lateral offset resulted in a significant reduction of the KAM. This trend was demonstrated in subjects with mild-to-moderate OA and in patients suffering from severe stages of the disease. Our results indicate that controlled manipulation of knee coronal kinetics in individuals suffering from medial knee OA can be facilitated by customized COP modification.

  16. Maturation and maintenance of cholinergic medial septum neurons require glucocorticoid receptor signaling.

    PubMed

    Guijarro, Christian; Rutz, Susanne; Rothmaier, Katharina; Turiault, Marc; Zhi, Qixia; Naumann, Thomas; Frotscher, Michael; Tronche, Francois; Jackisch, Rolf; Kretz, Oliver

    2006-05-01

    Glucocorticoids have been shown to influence trophic processes in the nervous system. In particular, they seem to be important for the development of cholinergic neurons in various brain regions. Here, we applied a genetic approach to investigate the role of the glucocorticoid receptor (GR) on the maturation and maintenance of cholinergic medial septal neurons between P15 and one year of age by using a mouse model carrying a CNS-specific conditional inactivation of the GR gene (GRNesCre). The number of choline acetyltransferase and p75NTR immuno-positive neurons in the medial septum (MS) was analyzed by stereology in controls versus mutants. In addition, cholinergic fiber density, acetylcholine release and cholinergic key enzyme activity of these neurons were determined in the hippocampus. We found that in GRNesCre animals the number of medial septal cholinergic neurons was significantly reduced during development. In addition, cholinergic cell number further decreased with aging in these mutants. The functional GR gene is therefore required for the proper maturation and maintenance of medial septal cholinergic neurons. However, the loss of cholinergic neurons in the medial septum is not accompanied by a loss of functional cholinergic parameters of these neurons in their target region, the hippocampus. This pinpoints to plasticity of the septo-hippocampal system, that seems to compensate for the septal cell loss by sprouting of the remaining neurons.

  17. Metric Measurements and Attachment Levels of the Medial Patellofemoral Ligament: An Anatomical Study in Cadavers

    PubMed Central

    Aragão, José Aderval; Reis, Francisco Prado; de Vasconcelos, Diego Protásio; Feitosa, Vera Lúcia Corrêa; Nunes, Marco Antonio Prado

    2008-01-01

    OBJECTIVE To determine the metric measurements and to verify the attachment levels of the medial patellofemoral ligament in human cadavers. METHODS Seventeen knees (eight right and nine left knees) from 10 cadavers (nine male and one female) were dissected and stored in a 10% formaldehyde solution. All of the knees were whole and did not show any macroscopic signs of injuries. RESULTS The medial patellofemoral ligament was present in 88% of the knees studied, localized transversally between the medial femoral epicondyle and the medial margin of the patella. Its dimensions were quite variable, even between the knees of the same individual. The width of the patellar insertion ranged from 16 to 38.8 mm, with a mean of 27.90 mm, and its mean length was 55.67 mm. The margins of the ligament were concave or rectilinear. At the upper margin, the concave form predominated and was better characterized, while at the lower margin, the rectilinear form predominated. CONCLUSIONS The medial patellofemoral ligament is a very distinct structure with variable anatomical aspects and is always located in a plane inferior to the vastus medialis obliquus muscle. PMID:18719768

  18. Physical examination and imaging of medial collateral ligament and posteromedial corner of the knee.

    PubMed

    Craft, Jason A; Kurzweil, Peter R

    2015-06-01

    The medial collateral ligament (MCL) is the most commonly injured knee ligament. Most will heal well with nonoperative treatment. However, not all medial knee injuries are the same. A detailed physical examination can help determine the severity of the medial-sided injury. When combined with advanced imaging, the examination will delineate damage to associated medial knee structures, including the location of MCL damage, posteromedial capsule injuries, and combined cruciate injuries. Failure to recognize MCL injuries that may be prone to chronic laxity can lead to significant disability, joint damage, and failure of concomitant cruciate ligament reconstructions. Magnetic resonance imaging is the mainstay of diagnostic imaging, with coronal sequences allowing full assessment of the MCL complex. Tangential views aid in the diagnosis of concomitant injuries. Stress radiography can play a role in evaluating MCL healing and subtle chronic laxity. Ultrasonography is also gaining acceptance as a means to assess MCL injuries. Use of a detailed examination and advanced imaging will allow optimal treatment of medial knee injuries and improve clinical outcomes.

  19. Weak Lie symmetry and extended Lie algebra

    SciTech Connect

    Goenner, Hubert

    2013-04-15

    The concept of weak Lie motion (weak Lie symmetry) is introduced. Applications given exhibit a reduction of the usual symmetry, e.g., in the case of the rotation group. In this context, a particular generalization of Lie algebras is found ('extended Lie algebras') which turns out to be an involutive distribution or a simple example for a tangent Lie algebroid. Riemannian and Lorentz metrics can be introduced on such an algebroid through an extended Cartan-Killing form. Transformation groups from non-relativistic mechanics and quantum mechanics lead to such tangent Lie algebroids and to Lorentz geometries constructed on them (1-dimensional gravitational fields).

  20. Critical level statistics for weakly disordered graphene.

    PubMed

    Amanatidis, E; Kleftogiannis, I; Katsanos, D E; Evangelou, S N

    2014-04-16

    In two dimensions chaotic level statistics with the Wigner spacing distribution P(S) is expected for massless fermions in the Dirac region. The obtained P(S) for weakly disordered finite graphene samples with zigzag edges turns out, however, to be neither chaotic (Wigner) nor localized (Poisson). It is similar to the intermediate statistics at the critical point of the Anderson metal-insulator transition. The quantum transport of finite graphene for weak disorder, with critical level statistics can occur via edge states as in topological insulators, and for strong disorder, graphene behaves as an ordinary Anderson insulator with Poisson statistics.

  1. Landau Weak Crystallization Theory and its Applications

    NASA Astrophysics Data System (ADS)

    Kats, E. I.

    Aim of this lecture is to explain main features and ingredients of weak first order phase transitions between liquid-like (uniform in space) and solid-like (non-uniform with characteristic wave vector q0) states. We illustrate how this theory (traditionally termed as Landau weak crystallization theory) works. We consider two examples describing universal temperature dependence of shear viscosity in liquids, and so-called main phase transition in membranes. Our results are in a good qualitative agreement with experimental data, offering a deeper understanding of this kind of phase transitions. We discuss also why and where predicted universal effects can be masked.

  2. Simple understanding of quantum weak values

    PubMed Central

    Qin, Lupei; Feng, Wei; Li, Xin-Qi

    2016-01-01

    In this work we revisit the important and controversial concept of quantum weak values, aiming to provide a simplified understanding to its associated physics and the origin of anomaly. Taking the Stern-Gerlach setup as a working system, we base our analysis on an exact treatment in terms of quantum Bayesian approach. We also make particular connection with a very recent work, where the anomaly of the weak values was claimed from the pure statistics in association with “disturbance” and “post-selection”, rather than the unique quantum nature. Our analysis resolves the related controversies through a clear and quantitative way. PMID:26838670

  3. Measuring the dark side (with weak lensing)

    SciTech Connect

    Amendola, Luca

    2008-04-15

    We introduce a convenient parameterization of dark energy models that is general enough to include several modified gravity models and generalized forms of dark energy. In particular we take into account the linear perturbation growth factor, the anisotropic stress and the modified Poisson equation. We discuss the sensitivity of large-scale weak lensing surveys like the proposed DUNE satellite to these parameters (assuming systematic errors can be controlled). We find that a large-scale weak lensing tomographic survey is able to easily distinguish the Dvali-Gabadadze-Porrati model from {Lambda}CDM and to determine the perturbation growth index to an absolute error of 0.02-0.04.

  4. Geometric Integration of Weakly Dissipative Systems

    NASA Astrophysics Data System (ADS)

    Modin, K.; Führer, C.; Soöderlind, G.

    2009-09-01

    Some problems in mechanics, e.g. in bearing simulation, contain subsystems that are conservative as well as weakly dissipative subsystems. Our experience is that geometric integration methods are often superior for such systems, as long as the dissipation is weak. Here we develop adaptive methods for dissipative perturbations of Hamiltonian systems. The methods are "geometric" in the sense that the form of the dissipative perturbation is preserved. The methods are linearly explicit, i.e., they require the solution of a linear subsystem. We sketch an analysis in terms of backward error analysis and numerical comparisons with a conventional RK method of the same order is given.

  5. A Novel Implant System for Unloading the Medial Compartment of the Knee by Lateral Displacement of the Iliotibial Band

    PubMed Central

    Shenoy, Vivek N.; Gifford, Hanson S.; Kao, John T.

    2017-01-01

    Background: Medial knee osteoarthritis (OA) typically occurs with excessive mechanical load within the medial compartment, resulting in degeneration of the articular cartilage. Purpose: A novel extracapsular implant (Latella Knee Implant) has been developed to unload the medial compartment of the knee. The implant displaces the iliotibial band (ITB) over the lateral femoral condyle, thereby increasing its effective moment arm, resulting in a transfer of load from the medial compartment to the lateral compartment of the knee. A cadaveric study was performed to evaluate the effect of altering the moment arm of the ITB on knee biomechanics. Study Design: Controlled laboratory study. Methods: A 6-degrees-of-freedom robotic testing system was utilized to measure medial and lateral compartment loads in 8 fresh-frozen cadaveric knees at various ITB loads and knee flexion angles. Measurements were made with and without the implant in place. The system measured the compartment forces at flexion angles between 0° and 30° under 3 simulated loading conditions (300 N quadriceps, 100 N hamstrings, and [1] 0 N ITB, [2] 50 N ITB, [3] 100 N ITB). Results: Lateral displacement of the ITB between 15 and 20 mm resulted in medial compartment unloading between 34% and 65%. Conclusion: Unloading the medial compartment with this novel implant has the potential to address the treatment gap for patients with medial knee OA. Clinical Relevance: Currently, there exists a treatment gap for patients with medial compartment OA who have exhausted conservative management but whose disease and symptoms do not warrant more invasive surgical procedures. An extracapsular implant to unload the medial compartment could fill this treatment gap by providing patients and surgeons with a less invasive option for early to mid-stage OA. Unloading the medial compartment may alleviate pain and improve function, allowing patients with early-stage medial OA to remain active longer prior to considering more

  6. Duane Syndrome

    MedlinePlus

    ... the eye muscles. In Duane syndrome, the sixth cranial nerve that controls the lateral rectus muscle (the muscle ... abnormal innervation of a branch from the third cranial nerve, which normally controls the medial rectus muscle (the ...

  7. Ankle inversion taping using kinesiology tape for treating medial ankle sprain in an amateur soccer player

    PubMed Central

    Lee, Sun-Min; Lee, Jung-Hoon

    2015-01-01

    [Purpose] The purpose of this study was to report the effects of ankle inversion taping using kinesiology tape in a patient with a medial ankle sprain. [Subject] A 28-year-old amateur soccer player suffered a Grade 2 medial ankle sprain during a match. [Methods] Ankle inversion taping was applied to the sprained ankle every day for 2 months. [Results] His symptoms were reduced after ankle inversion taping application for 2 months. The self-reported function score, the reach distances in the Star Excursion Balance Test, and the weight-bearing ankle dorsiflexion were increased. [Conclusion] This study showed that ankle inversion taping using kinesiology tape may be an effective therapy for a patient with a medial ankle sprain. PMID:26311991

  8. Management of acute isolated medial and posteromedial instability of the knee.

    PubMed

    Roth, Jonathan; Taylor, Dean C

    2015-06-01

    Medial-sided knee injuries are very common, the medial collateral ligament being the most commonly injured ligament of the knee. Injuries to the medial side of the knee can occur in isolation or concomitant with other knee ligament injuries. Isolated grade I and II injuries have been typically treated nonoperatively with excellent results. Isolated grade III injuries, however, are less common and more controversial. Although some recent literature has shown acceptable results with nonoperative treatment of isolated grade III injuries, most authors recommend surgical treatment. A variety of operative techniques have been described, including repair, augmentation, and reconstruction, all with favorable outcomes. Choice of treatment method should be based on injury pattern with the goal of regaining valgus and anteromedial rotatory stability of the knee.

  9. [SOUND SIGNALS OF DANGER ACTIVATE THE NITRERGIC SYSTEM OF THE MEDIAL PREFRONTAL CORTEX].

    PubMed

    Sudorgina, P V; Saulskaya, N B

    2015-07-01

    In Sprague-Dawley rats by means of in vivo microdialysis, we have shown that presentation to rats-during conditioned fear expression of a sound conditioned stimulus previously paired with footshock (CS+) produces an increase in extracellular levels of citrulline (an NO co-product) in the medial prefrontal cortex. Presentation to the same rats of a different sound stimulus (not associated with footshock) (CS-) causes a very small increase in extracellular citrulline level. CS+ induced citrulline increase is prevented by infusions into the medial prefrontal cortex of Nomega-propyl-L-arginine (1 mM), a neuronal NO synthase inhibitor and it is not observed in control rats (same procedure, no footshock). These data indicate for the first time that sound signals of danger, but not safety signals activate nitrergic system of the medial prefrontal cortex.

  10. Extracellular norepinephrine in the medial hypothalamus increases during feeding in chicks: a microdialysis study.

    PubMed

    Tachibana, T; Utimura, D; Kato, H; Kubo, T; Sugahara, K

    2000-11-01

    Norepinephrinergic function in the medial hypothalamus is important for the regulation of feeding behavior in chicks as well as in rats. This study was conducted to clarify the variation of extracellular norepinephrine (NE) in the medial hypothalamus, including the paraventricular nucleus (PVN) and the ventromedial hypothalamic nucleus (VMN), during feeding behavior of layer-type chicks. To measure extracellular NE and 4-hydroxy-3-methoxyphenylglycol (MHPG), a major metabolite of NE, we used microdialysis and high-pressure liquid chromatography (HPLC) with electrochemical detection. After the collection of baseline samples, food-deprived animals were allowed access to the food for 3 h. Extracellular NE significantly increased during the first hour of access to food, and then returned to baseline levels. MHPG also increased during the feeding, but its increase continued throughout the remainder of the experiment. This study suggests that the variation of NE in the medial hypothalamus may be involved in the control of feeding in layer-type chicks.

  11. Intact Visual Perception in Memory-Impaired Patients with Medial Temporal Lobe Lesions

    PubMed Central

    Shrager, Yael; Gold, Jeffrey J.; Hopkins, Ramona O.; Squire, Larry R.

    2006-01-01

    A recent proposal that structures of the medial temporal lobe support visual perception in addition to memory challenges the long-standing idea that the ability to acquire new memories is separable from other cognitive and perceptual functions. In four experiments, we have put this proposal to a rigorous test. Six memory-impaired patients with well characterized lesions of either the hippocampal region or the hippocampal region plus additional medial temporal lobe structures were assessed on difficult tests of visual perceptual discrimination. Across all four experiments, the patients performed as well as controls. The results show that visual perception is intact in memory-impaired patients with damage to the medial temporal lobe even when perception is assessed with challenging tasks. Furthermore, the results support the principle that the ability to acquire new memories is a distinct cerebral function, dissociable from other perceptual and cognitive functions. PMID:16495450

  12. Grossly apparent cartilage erosion of the patellar articular surface in dogs with congenital medial patellar luxation.

    PubMed

    Daems, R; Janssens, L A; Béosier, Y M

    2009-01-01

    One hundred and forty-five stifles of client-owned dogs that underwent corrective surgery for congenital medial patellar luxation were inspected for cartilage erosion on the articular surface of the patella. The lesions were mapped in surface percentage ranges of 20% and by location. Two-thirds of the patellae had cartilage erosion. Cartilage erosion varied between 0 and 100% of the total patellar articular surface and was localised mainly on the medial and distal side of the patella. Dogs with Grade IV patellar luxations and heavier dogs were more affected. The majority of dogs in our study with congenital medial patellar luxation had grossly apparent cartilage erosion on the articular surface of the patella, which may help to explain why certain patients do not function well clinically after technically successful corrective surgery.

  13. A new surgical technique for medial collateral ligament balancing: multiple needle puncturing.

    PubMed

    Bellemans, Johan; Vandenneucker, Hilde; Van Lauwe, Johan; Victor, Jan

    2010-10-01

    In this article, we present our experience with a new technique for medial soft tissue balancing, where we make multiple punctures in the medial collateral ligament (MCL) using a 19-gauge needle, to progressively stretch the MCL until a correct ligament balance is achieved. Ligament status was evaluated both before and after the procedure using computer navigation and mediolateral stress testing. The procedure was considered successful when 2 to 4-mm mediolateral joint line opening was obtained in extension and 2 to 6 mm in flexion. In 34 of 35 cases, a progressive correction of medial tightness was achieved according to the above described criteria. One case was considered overreleased in extension. Needle puncturing is a new, effective, and safe technique for progressive correction of MCL tightness in the varus knee.

  14. Vocal fold medialization with tragal cartilage and perichondrium in high vagal paralysis.

    PubMed

    Chirilă, Magdalena; Mureşan, Rodica

    2013-05-01

    The goal of this pilot study was to test vocal fold medialization using autologous tragal cartilage and perichondrium by direct approach for treating high vagal paralysis. Five patients with the skull base tumors with involvement of the vagus nerve underwent concurrent vocal fold medialization with surgical excision. The patients were evaluated preoperatively, and at 14, 60 days, and 6 months later. Complete medialization with horizontal and vertical realignment was achieved. Improvement of voice and breathiness was correlated with the increase of closed quotient; the contact area of the vocal fold mucosa has increased. This advancement reduces breathiness and induced an improvement in subglottic pressure with aerodynamic parameters improvement, which led to stabilization of the vocal fold oscillation and a better voice quality recovery. This method can be considered a safe, quick, and efficient phonosurgical procedure combined with a skull-base surgical procedure.

  15. Panmedullary edema with inferior olivary hypertrophy in bilateral medial medullary infarction.

    PubMed

    Inoue, Yasuteru; Miyashita, Fumio; Koga, Masatoshi; Yamada, Naoaki; Toyoda, Kazunori; Minematsu, Kazuo

    2014-03-01

    Bilateral medial medullary infarction (MMI) is a rare type of stroke with poor outcomes. Inferior olivary nucleus hypertrophy results from a pathologic lesion in the Guillain-Mollaret triangle. The relationship between inferior olivary nucleus hypertrophy and the medullary lesion is obscure. To the best of our knowledge, only 1 autopsy case with unilateral medial medullary infarction that was associated with ipsilateral inferior olivary nucleus hypertrophy has been reported. We describe a rare case with acute infarction in the bilateral medial medulla oblongata accompanied by subacute bilateral inferior olivary nucleus hypertrophy and panmedullary edema. The hypertrophy appeared to have been caused by local ischemic damage to the termination of the central tegmental tract at the bilateral inferior olivary nucleus.

  16. Glutamate microinjection in the medial septum of rats decreases paradoxical sleep and increases slow wave sleep.

    PubMed

    Mukherjee, Didhiti; Kaushik, Mahesh K; Jaryal, Ashok Kumar; Kumar, Velayudhan Mohan; Mallick, Hruda Nanda

    2012-05-09

    The role of the medial septum in suppressing paradoxical sleep and promoting slow wave sleep was suggested on the basis of neurotoxic lesion studies. However, these conclusions need to be substantiated with further experiments, including chemical stimulation studies. In this report, the medial septum was stimulated in adult male rats by microinjection of L-glutamate. Sleep-wakefulness was electrophysiologically recorded, through chronically implanted electrodes, for 2 h before the injection and 4 h after the injection. There was a decrease in paradoxical sleep during the first hour and an increase in slow wave sleep during the second hour after the injection. The present findings not only supported the lesion studies but also showed that the major role of the medial septum is to suppress paradoxical sleep.

  17. Reconstruction of lateral forefoot using reversed medial plantar flap with free anterolateral thigh flap.

    PubMed

    Fujioka, Masaki; Hayashida, Kenji; Senju, Chikako

    2014-01-01

    Skin defects of the heel have frequently been reconstructed using the medial plantar flap; however, forefoot coverage has remained a challenge, because the alternatives for flap coverage have been very limited. We describe a case of malignant melanoma on the lateral forefoot that was radically removed and reconstructed successfully with a distally based medial plantar flap, together with a free anterolateral thigh flap. The advantages of this flap include that it does not reduce the vascular supply to the foot owing to reconstruction of the medial plantar vascular systems, reduces the risk of flap congestion, minimizes donor site morbidity, and enables the transport of structurally similar tissues to the plantar forefoot. We believe this technique is a reasonable reconstructive option for large lateral plantar forefoot defects.

  18. Transient medial patellar dislocation: injury patterns at US and MR imaging.

    PubMed

    Le Corroller, Thomas; Dediu, Melania; Champsaur, Pierre

    2009-05-01

    Medial dislocation of the patella is an unusual entity. It is usually an iatrogenic complication of surgical lateral retinacular release. We describe the clinical, ultrasound (US), and magnetic resonance (MR) imaging features of a transient medial patellar dislocation in a 19-year-old patient with trochlear groove dysplasia presenting no surgical history. US showed acute injury to the lateral patellar retinaculum with complete avulsion at its patellar insertion. MR imaging confirmed the complete tear of the lateral patellar retinaculum and disclosed contusion of the anteromedial portion of the medial femoral condyle and lateral patella. This case is noteworthy because the injury patterns of patellar soft tissue restraints differ markedly from the classical features of lateral patellar dislocation.

  19. Molecular Handshake: Recognition through Weak Noncovalent Interactions

    ERIC Educational Resources Information Center

    Murthy, Parvathi S.

    2006-01-01

    The weak noncovalent interactions between substances, the handshake in the form of electrostatic interactions, van der Waals' interactions or hydrogen bonding is universal to all living and nonliving matter. They significantly influence the molecular and bulk properties and behavior of matter. Their transient nature affects chemical reactions and…

  20. Weak radiative baryonic decays of B mesons

    SciTech Connect

    Kohara, Yoji

    2004-11-01

    Weak radiative baryonic B decays B{yields}B{sub 1}B{sub 2}-bar{gamma} are studied under the assumption of the short-distance b{yields}s{gamma} electromagnetic penguin transition dominance. The relations among the decay rates of various decay modes are derived.

  1. Engineering molecular crystals with abnormally weak cohesion.

    PubMed

    Maly, Kenneth E; Gagnon, Eric; Wuest, James D

    2011-05-14

    Adding astutely placed methyl groups to hexaphenylbenzene increases molecular weight but simultaneously weakens key C-H···π interactions, thereby leading to decreased enthalpies of sublimation and showing that materials with abnormally weak cohesion can be made by identifying and then obstructing interactions that help control association.

  2. Resource Letter WI-1: Weak Interactions

    ERIC Educational Resources Information Center

    Holstein, Barry R.

    1977-01-01

    Provides a listing of sources of literature and teaching aids to improve course content in the fields of: weak interactions, beta decay, orbital electron capture, muon capture, semileptonic decay, nonleptonic processes, parity violation in nuclei, neutrino physics, and parity violation in atomic physics. (SL)

  3. [A strong man with a weak shoulder].

    PubMed

    Henket, Marjolijn; Lycklama á Nijeholt, Geert J; van der Zwaal, Peer

    2013-01-01

    A 47-year-old former olympic athlete had pain and weakness of his left shoulder. There was no prior trauma. He had full range-of-motion and a scapular dyskinesia. There was atrophy of the trapezius and sternocleidomastoideus muscles. He was diagnosed with 'idiopathic neuritis of the accessorius nerve'.

  4. Musculotendinous infraspinatus rupture and shoulder weakness.

    PubMed

    Lipford, Melissa C; Bond, Jeffrey R; Steinmann, Scott P; Kumar, Neeraj

    2011-12-01

    We report a patient with bilateral simultaneous onset of weakness of shoulder lateral rotation due to musculotendinous infraspinatus rupture that occurred after shoulder steroid injections. Disruption of the musculotendinous junction of the infraspinatus is a rare recently described entity. Electromyography is normal, and magnetic resonance image findings are characteristic.

  5. Modeling, Measuring, and Compensating Color Weak Vision.

    PubMed

    Oshima, Satoshi; Mochizuki, Rika; Lenz, Reiner; Chao, Jinhui

    2016-06-01

    We use methods from Riemann geometry to investigate transformations between the color spaces of color-normal and color-weak observers. The two main applications are the simulation of the perception of a color weak observer for a color-normal observer, and the compensation of color images in a way that a color-weak observer has approximately the same perception as a color-normal observer. The metrics in the color spaces of interest are characterized with the help of ellipsoids defined by the just-noticeable-differences between the colors which are measured with the help of color-matching experiments. The constructed mappings are the isometries of Riemann spaces that preserve the perceived color differences for both observers. Among the two approaches to build such an isometry, we introduce normal coordinates in Riemann spaces as a tool to construct a global color-weak compensation map. Compared with the previously used methods, this method is free from approximation errors due to local linearizations, and it avoids the problem of shifting locations of the origin of the local coordinate system. We analyze the variations of the Riemann metrics for different observers obtained from new color-matching experiments and describe three variations of the basic method. The performance of the methods is evaluated with the help of semantic differential tests.

  6. Modelling, Measuring and Compensating Color Weak Vision.

    PubMed

    Oshima, Satoshi; Mochizuki, Rika; Lenz, Reiner; Chao, Jinhui

    2016-03-08

    We use methods from Riemann geometry to investigate transformations between the color spaces of color-normal and color weak observers. The two main applications are the simulation of the perception of a color weak observer for a color normal observer and the compensation of color images in a way that a color weak observer has approximately the same perception as a color normal observer. The metrics in the color spaces of interest are characterized with the help of ellipsoids defined by the just-noticable-differences between color which are measured with the help of color-matching experiments. The constructed mappings are isometries of Riemann spaces that preserve the perceived color-differences for both observers. Among the two approaches to build such an isometry, we introduce normal coordinates in Riemann spaces as a tool to construct a global color-weak compensation map. Compared to previously used methods this method is free from approximation errors due to local linearizations and it avoids the problem of shifting locations of the origin of the local coordinate system. We analyse the variations of the Riemann metrics for different observers obtained from new color matching experiments and describe three variations of the basic method. The performance of the methods is evaluated with the help of semantic differential (SD) tests.

  7. Ostectomy and Medial Plantar Artery Flap Reconstruction for Charcot Foot Ulceration Involving the Midfoot.

    PubMed

    Sato, Tomoya; Ichioka, Shigeru

    2016-01-01

    Charcot foot is a serious complication of diabetes, characterized by deformity and overlying ulceration. The condition most commonly affects the midfoot. However, little information is available on the use of a medial plantar artery flap to treat diabetic midfoot ulceration. The purpose of the present study was to evaluate the versatility of ostectomy and medial plantar flap reconstruction for midfoot plantar ulceration associated with rocker-bottom deformity secondary to Charcot foot. Four patients underwent ostectomy and medial plantar flap reconstruction. Before flap reconstruction, the devitalized soft tissues and bone were radically resected. After the infection had been controlled, the ulcerated portion was minimally excised, and the bony prominence underlying the ulcer was removed. A medial plantar artery flap was applied to the ulcer. The donor site was covered with a split-thickness skin graft or artificial dermis. In all patients, the ulcers healed and independent ambulation was achieved. However, 1 patient experienced ulcer recurrence, and subsequent infection necessitated a major amputation. Limb salvage is challenging in the setting of deformity and intractable plantar ulceration. The advantages of medial plantar artery flap reconstruction are that tissues with a rich blood supply are used to cover the exposed bone, and the flap can withstand the pressure and shear stress of the patient's body weight. However, a dominant artery in the foot is sacrificed. Therefore, the patency of the dorsalis pedis artery must be confirmed in every patient. The results of the present study have demonstrated that a medial plantar artery can be an effective alternative for diabetic patients with a plantar ulcer secondary to Charcot foot.

  8. Medial Orbitofrontal Neurons Preferentially Signal Cues Predicting Changes in Reward during Unblocking

    PubMed Central

    Lopatina, Nina; McDannald, Michael A.; Styer, Clay V.; Peterson, Jacob F.; Sadacca, Brian F.; Cheer, Joseph F.

    2016-01-01

    The orbitofrontal cortex (OFC) has been broadly implicated in the ability to use the current value of expected outcomes to guide behavior. Although value correlates have been prominently reported in lateral OFC, they are more often associated with more medial areas. Further, recent studies in primates have suggested a dissociation in which the lateral OFC is involved in credit assignment and representation of reward identity and more medial areas are critical to representing value. Previously, we used unblocking to test more specifically what information about outcomes is represented by OFC neurons in rats; consistent with the proposed dichotomy between the lateral and medial OFC, we found relatively little linear value coding in the lateral OFC (Lopatina et al., 2015). Here we have repeated this experiment, recording in the medial OFC, to test whether such value signals might be found there. Neurons were recorded in an unblocking task as rats learned about cues that signaled either more, less, or the same amount of reward. We found that medial OFC neurons acquired responses to these cues; however, these responses did not signal different reward values across cues. Surprisingly, we found that cells developed responses to cues predicting a change, particularly a decrease, in reward value. This is consistent with a special role for medial OFC in representing current value to support devaluation/revaluation sensitive changes in behavior. SIGNIFICANCE STATEMENT This study uniquely examines encoding in rodent mOFC at the single-unit level in response to cues that predict more, less, or no change in reward in rats during training in a Pavlovian unblocking task, finding more cells responding to change-predictive cues and stronger activity in response to cues predictive of less reward. PMID:27511013

  9. Medial Tibiofemoral-Joint Stiffness in Males and Females Across the Lifespan.

    PubMed

    Aronson, Patricia; Rijke, Arie; Hertel, Jay; Ingersoll, Christopher D

    2014-02-12

    Context : Analyzing ligament stiffness between males and females at 3 maturational stages across the lifespan may provide insight into whether changes in ligament behavior with aging may contribute to joint laxity. Objective : To compare the stiffness of the medial structures of the tibiofemoral joint and the medial collateral ligament to determine if there are differences at 3 distinct ages and between the sexes. Design : Cross-sectional study. Setting : Laboratory. Patients or Other Participants : A total of 108 healthy and physically active volunteers with no previous knee surgery, no knee injury, and no use of exogenous hormones in the past 6 months participated. They were divided into 6 groups based on sex and age (8-10, 18-40, 50-75 years). Main Outcome Measure(s) : Ligament stiffness of the tibiofemoral joint was measured with an arthrometer in 0° and 20° of tibiofemoral-joint flexion. The slope values of the force-strain line that represents stiffness of the medial tibiofemoral joint at 0° and the medial collateral ligament at 20° of flexion were obtained. Results : When height and mass were controlled, we found a main effect (P < .001) for age group: the 8- to 10-year olds were less stiff than both the 18- to 40- and the 50- to 75-year-old groups. No effects of sex or tibiofemoral-joint position on stiffness measures were noted when height and mass were included as covariates. Conclusions : Prepubescent medial tibiofemoral-joint stiffness was less than postpubescent knee stiffness. Medial tibiofemoral-joint stiffness was related to height and mass after puberty in men and women.

  10. Multiple telencephalic and extratelencephalic embryonic domains contribute neurons to the medial extended amygdala.

    PubMed

    Bupesh, Munisamy; Legaz, Isabel; Abellán, Antonio; Medina, Loreta

    2011-06-01

    Dysfunctions in emotional control and social behavior are behind human neuropsychiatric disorders, some of which are associated with an alteration of amygdalar development. The medial extended amygdala is a key telencephalic center for control of social behavior, but very little is known about its development. We used in vitro migration assays for analyzing the origin of the neurons of the medial extended amygdala in mouse embryos (E13.5-E16.5). We compared the migration assays with immunofluorescence/immunohistochemistry for calbindin and radial glial fibers and with mRNA expression of several genetic markers of distinct forebrain subdivisions. We provide experimental evidence for multiple embryonic origins of the principal neurons of the medial extended amygdala. In particular, we provide novel evidence indicating that a major part of the neurons derives from a caudoventral pallidal subdivision (previously called or included as part of the anterior peduncular area), forming a cell corridor with similar molecular features (expression of Lhx6 and calbindin), connectivity, and function, which relates to reproductive behavior. We also provide novel experimental evidence indicating that the ventral pallium produces some neurons for the medial amygdala, which correlates with data from Lhx9 expression. Our results also confirm that some neurons of the medial extended amygdala originate in the preoptic area (our results indicate that these cells specifically originate in its commissural subdivision) and the supraoptoparaventricular domain of the hypothalamus. Our study helps to set up the foundations for a better understanding of medial amygdalar control of behavior in normal and abnormal conditions.

  11. Oxford unicompartmental knee arthroplasty: medial pain and functional outcome in the medium term

    PubMed Central

    2011-01-01

    Background In our experience results of the Oxford unicompartmental knee replacement have not been as good as had been expected. A common post operative complaint is of persistent medial knee discomfort, it is not clear why this phenomenon occurs and we have attempted to address this in our study. Methods 48 patients were retrospectively identified at a mean of 4.5 years (range = 3 to 6 years) following consecutive Oxford medial Unicompartmental Knee arthroplasties for varus anteromedial osteoarthritis. The mean age at implantation was 67 years (range 57-86). Of these 48 patients, 4 had died, 4 had undergone revision of their unicompartmental knee replacements and 2 had been lost to follow up leaving 38 patients with 40 replaced knees available for analysis using the 'new Oxford Knee Score' questionnaire. During assessment patients were asked specifically whether or not they still experienced medial knee discomfort or pain. Results The mean 'Oxford score' was only 32.7 (range = 16 to 48) and 22 of the 40 knees were uncomfortable or painful medially. The accuracy of component positioning was recorded, using standard post operative xrays, by summing the angulation or displacement of each component in two planes from the ideal position (according to the 'Oxford knee system radiographic criteria'). No correlation was demonstrated between the radiographic scores and the 'Oxford scores', or with the presence or absence of medial knee discomfort or pain. Conclusion In our hands the functional outcome following Oxford Unicompartmental knee replacement was variable, with a high incidence of medial knee discomfort which did not correlate with the postoperative radiographic scores, pre-op arthritis and positioning of the prosthesis. PMID:21981987

  12. Medial Tibiofemoral-Joint Stiffness in Males and Females Across the Lifespan

    PubMed Central

    Aronson, Patricia; Rijke, Arie; Hertel, Jay; Ingersoll, Christopher D.

    2014-01-01

    Context: Analyzing ligament stiffness between males and females at 3 maturational stages across the lifespan may provide insight into whether changes in ligament behavior with aging may contribute to joint laxity. Objective: To compare the stiffness of the medial structures of the tibiofemoral joint and the medial collateral ligament to determine if there are differences at 3 distinct ages and between the sexes. Design: Cross-sectional study. Setting: Laboratory. Patients or Other Participants: A total of 108 healthy and physically active volunteers with no previous knee surgery, no acute knee injury, and no use of exogenous hormones in the past 6 months participated. They were divided into 6 groups based on sex and age (8–10, 18–40, 50–75 years). Main Outcome Measure(s): Ligament stiffness of the tibiofemoral joint was measured with an arthrometer in 0° and 20° of tibiofemoral-joint flexion. The slope values of the force-strain line that represents stiffness of the medial tibiofemoral joint at 0° and the medial collateral ligament at 20° of flexion were obtained. Results: When height and mass were controlled, we found a main effect (P < .001) for age group: the 8- to 10-year olds were less stiff than both the 18- to 40- and the 50- to 75-year-old groups. No effects of sex or tibiofemoral-joint position on stiffness measures were noted when height and mass were included as covariates. Conclusions: Prepubescent medial tibiofemoral-joint stiffness was less than postpubescent knee stiffness. Medial tibiofemoral-joint stiffness was related to height and mass after puberty in men and women. PMID:24955624

  13. The correlation between medial plica and trochlear dysplasis: An MRI study

    PubMed Central

    Ekin, Elif E; Yildiz, Hülya K; Mutlu, Harun; Çetinkaya, Engin

    2016-01-01

    Background: Trochlear dysplasia is the most commonly encountered congenital etiologic factor of anterior knee pain. Aims: The purpose of this study was to evaluate the relationship between trochlear dysplasia with medial patellar plica as well as to investigate the distribution of plica types according to types of dysplasia. Settings and Design: This is a retrospective case-control study. Materials and Methods: This study was conducted among 138 knee magnetic resonance imaging (MRI) scans. The presence of medial plica and its types were compared among 69 patients in whom trochlear dysplasia had been detected and 69 individuals with normal trochlear who were of the same age and gender as the patient group. Statistical Analysis: Trochlear dysplasia and medial plica was compared by Chi-square with Yates correction and Fisher's exact probability tests (P < 0.001). The data were presented as mean, standard deviation, minimum–maximum, frequency, and percentage. Results: Of all the patients (n = 138), the number of patients in whom plica was observed was n = 104 (75.3%), and the distribution of plica type was as follows: n = 70 (67.3%) Type 1, n = 25 (24%) Type 2, and n = 9 (8.6%) Type 3. Medial plica was more frequently observed in patients with trochlear dysplasia (P < 0.001). Type 2 and Type 3 medial plica were more frequently encountered in trochlear dysplasia (P < 0.001). Type 3 plica was not seen in patients with normal trochlea. Conclusion: Medial patellar plica is more frequently seen in trochlear dysplasia. As the type of trochlear dysplasia progresses, the prevalence of thicker and shelf-shaped plica increases. PMID:28104937

  14. The effects of kinematically aligned total knee arthroplasty on stress at the medial tibia

    PubMed Central

    Tian, Y.; Tanaka, Y.; Kuriyama, S.; Ito, H.; Furu, M.; Matsuda, S.

    2017-01-01

    Objectives Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments. Materials and Methods Bone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis. Results In all bone models, posterior translation on the lateral side and external rotation in the KA TKA models were greater than in the MA TKA models. The tibiofemoral force at the medial side was increased in the moderate and severe varus models with KA TKA. In the severe varus model with KA TKA, the contact stress on the tibial insert and the stress to the resection surface and to the medial tibial cortex were increased by 41.5%, 32.2% and 53.7%, respectively, compared with MA TKA, and the bone strain at the medial side was highest among all models. Conclusion Near normal kinematics was observed in KA TKA. However, KA TKA increased the contact force, stress and bone strain at the medial side for moderate and severe varus knee models. The application of KA TKA for severe varus knees may be inadequate. Cite this article: S. Nakamura, Y. Tian, Y. Tanaka, S. Kuriyama, H. Ito, M. Furu, S. Matsuda. The effects of kinematically aligned total knee arthroplasty on stress at the medial tibia: A case study for varus knee. Bone Joint Res 2017;6:43–51. DOI: 10.1302/2046-3758.61.BJR-2016-0090.R1. PMID:28077396

  15. Role of the medial septum cholinoceptors in anxiogenic-like effects of nicotine.

    PubMed

    Zarrindast, Mohammad-Reza; Tajik, Rohjan; Ebrahimi-Ghiri, Mohaddeseh; Nasehi, Mohammad; Rezayof, Ameneh

    2013-07-02

    The medial septum which is extensively connected to the hippocampus is involved in cholinergic theta oscillation control as well as the anxiety related disorders. In the present study, we aimed to investigate the possible involvement of the medial septum cholinoceptors in the nicotine-induced anxiogenic-like behaviors in rats, using the elevated plus-maze (EPM) test. Intraperitoneal administration of nicotine at 0.6 and 0.8 mg/kg, decreased the open-arms time percentage (%OAT) and open-arms entries percentage (%OAE); indicating an anxiogenic-like response. Intra-medial septum microinjection of mecamylamine, a nicotinic acetylcholine receptor (nAChR) antagonist at the doses of 1-4 μg/rat, increased %OAT (4 μg/rat), suggesting an anxiolytic-like effect. This however, did not alter the anxiogenic-like response induced by the effective dose of nicotine (0.6 mg/kg). Moreover, co-administration of the subthreshold dose of mecamylamine (2 μg/rat) plus nicotine at the dose of 0.5 or 0.6 mg/kg, increased or decreased the anxiolytic-like behaviors, respectively. On the other hand, sole intra-medial septum infusion of atropine, a muscarinic acetylcholine receptor (mAChR) antagonist, induced an anxiolytic (0.05 μg/rat) and anxiogenic (0.25 μg/rat)-like effects, respectively. The dose of 0.05 μg/rat however, blocked the nicotine response. Furthermore, intra-medial septum microinjection of the highest dose of mecamylamine (4 μg/rat) plus nicotine (0.6 mg/kg) decreased the locomotor activity, while other treatments had no effect on this parameter. Our results suggested that, nicotine-induced anxiogenic-like behaviors may be mediated via the activation of cholinoceptors and possibly other receptor mechanism(s) in the medial septum.

  16. Histaminergic receptors of medial septum and conditioned place preference: D1 dopamine receptor mechanism.

    PubMed

    Zarrindast, Mohammad-Reza; Moghimi, Maryam; Rostami, Parvin; Rezayof, Ameneh

    2006-09-13

    In the present study, the effects of intra-medial septum injections of histamine and/or the histamine H1 or H2 receptor antagonists on the acquisition of conditioned place preference (CPP) in male Wistar rats have been investigated. Our data showed that the conditioning treatments with intra-medial septum injection of different doses of histamine (0.5-15 microg/rat) induced a significant CPP for the drug-associated place. Using a 3-day schedule of conditioning, it was found that the histamine H1 receptor antagonist, pyrilamine (10 and 15 microg/rat, intra-medial septum) also induced a significant place preference. In addition, pyrilamine inhibited the histamine (7.5 microg/rat)-induced place preference. Intra-medial septum administration of the histamine H2 receptor antagonist, ranitidine (5-15 microg/rat) alone or in combination with histamine did not produce a significant place preference or place aversion. On the other hand, intra-medial septum administration of the dopamine D1 receptor antagonist, SCH 233390 (0.5, 0.75 and 1 microg/rat) inhibited the histamine (7.5 microg/rat) or pyrilamine (15 microg/rat)-induced place preference in a dose-dependent manner, but no effect was observed for the dopamine D2 receptor antagonist, sulpiride on the histamine or pyrilamine response. The administration of histamine (2.5-15 microg/rat) or pyrilamine (10 and 15 microg/rat) during acquisition increased locomotor activity of the animals on the testing days. The results suggest that histaminergic receptors of the medial septum may be involved in CPP and thus it is postulated that dopamine D1 receptors may play an important role in this effect.

  17. Effect of Posterior Horn Medial Meniscus Root Tear on In Vivo Knee Kinematics

    PubMed Central

    Marsh, Chelsea A.; Martin, Daniel E.; Harner, Christopher D.; Tashman, Scott

    2014-01-01

    Background: Medial meniscus root tear (MMRT) is a recently recognized yet frequently missed meniscal tear pattern that biomechanically creates an environment approaching meniscal deficiency. Hypothesis/Purpose: The purpose of this study was to assess the effect of MMRT on tibiofemoral kinematics and arthrokinematics during daily activities by comparing the injured knees of subjects with isolated MMRT to their uninjured contralateral knees. The hypothesis was that the injured knee will demonstrate significantly more lateral tibial translation and adduction than the uninjured knee, and that the medial compartment will exhibit significantly different arthrokinematics than the lateral compartment in the affected limb. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Seven subjects with isolated MMRT were recruited and volumetric, density-based 3-dimensional models of their distal femurs and proximal tibia were created from computed tomography scans. High-speed, biplane radiographs were obtained of both their affected and unaffected knees. Moving 3-dimensional models of tibiofemoral kinematics were calculated using model-based tracking to assess overall kinematic variables and specific measures of tibiofemoral joint contact. The affected knees of the subjects were then compared to their unaffected contralateral knees. Results: Affected knees demonstrated significantly more lateral tibial translation than the uninjured contralateral limb in all dynamic activities. Additionally, the medial compartment displayed greater amounts of mobility than the lateral compartment in the injured limbs. Conclusion: This study suggests that MMRT causes significant changes in in vivo knee kinematics and arthrokinematics and that the magnitude of these changes is influenced by dynamic task difficulty. Clinical Relevance: Medial meniscus root tears lead to significant changes in joint arthrokinematics, with increased lateral tibial translation and greater medial

  18. Cosmological model discrimination with weak lensing

    NASA Astrophysics Data System (ADS)

    Pires, S.; Starck, J.-L.; Amara, A.; Réfrégier, A.; Teyssier, R.

    2009-10-01

    Weak gravitational lensing provides a unique way of mapping directly the dark matter in the Universe. The majority of lensing analyses use the two-point statistics of the cosmic shear field to constrain the cosmological model, a method that is affected by degeneracies, such as that between σ8 and Ωm which are respectively the rms of the mass fluctuations on a scale of 8 Mpc/h and the matter density parameter, both at z = 0. However, the two-point statistics only measure the Gaussian properties of the field, and the weak lensing field is non-Gaussian. It has been shown that the estimation of non-Gaussian statistics for weak lensing data can improve the constraints on cosmological parameters. In this paper, we systematically compare a wide range of non-Gaussian estimators to determine which one provides tighter constraints on the cosmological parameters. These statistical methods include skewness, kurtosis, and the higher criticism test, in several sparse representations such as wavelet and curvelet; as well as the bispectrum, peak counting, and a newly introduced statistic called wavelet peak counting (WPC). Comparisons based on sparse representations indicate that the wavelet transform is the most sensitive to non-Gaussian cosmological structures. It also appears that the most helpful statistic for non-Gaussian characterization in weak lensing mass maps is the WPC. Finally, we show that the σ8 - Ωm degeneracy could be even better broken if the WPC estimation is performed on weak lensing mass maps filtered by the wavelet method, MRLens.

  19. Cosmological model discrimination from weak lensing data

    NASA Astrophysics Data System (ADS)

    Pires, S.; Starck, J.-L.; Amara, A.; Réfrégier, A.; Teyssier, R.

    2010-06-01

    Weak gravitational lensing provides a unique way of mapping directly the dark matter in the Universe. The majority of lensing analyses use the two-point statistics of the cosmic shear field to constrain the cosmological model, a method that is affected by degeneracies, such as that between σ8 and Ωm which are respectively the rms of the mass fluctuations on a scale of 8 Mpc/h and the matter density parameter, both at z = 0. However, the two-point statistics only measure the Gaussian properties of the field, and the weak lensing field is non-Gaussian. It has been shown that the estimation of non-Gaussian statistics for weak lensing data can improve the constraints on cosmological parameters. In this paper, we systematically compare a wide range of non-Gaussian estimators to determine which one provides tighter constraints on the cosmological parameters. These statistical methods include skewness, kurtosis, and the higher criticism test, in several sparse representations such as wavelet and curvelet; as well as the bispectrum, peak counting, and a newly introduced statistic called wavelet peak counting (WPC). Comparisons based on sparse representations indicate that the wavelet transform is the most sensitive to non-Gaussian cosmological structures. It also appears that the most helpful statistic for non-Gaussian characterization in weak lensing mass maps is the WPC. Finally, we show that the σ8-Ωm degeneracy could be even better broken if the WPC estimation is performed on weak lensing mass maps filtered by the wavelet method, MRLens.

  20. Selective disappearance of medial back muscles in a case of myotonic dystrophy type 1.

    PubMed

    Morihara, Ryuta; Hishikawa, Nozomi; Yamashita, Toru; Deguchi, Kentaro; Kurata, Tomoko; Abe, Koji

    2015-01-01

    Here, we report a unique case of late-onset myotonic dystrophy type 1 in a 64-year-old woman, with selective disappearance of the medial lower back muscles. We compared the clinical features of this patient with those of a cohort of 29 patients with myotonic dystrophy type 1 to clarify the correlation between clinical features and lower back muscle atrophy. After classification into three subgroups according to muscle atrophy pattern, medial muscle atrophy was present in 17.2% of the patients. Affected patients were older at onset than non-affected patients, and limb muscle power and respiratory function decreased with atrophy progression.

  1. Medial malleolus fracture of the ankle combined with rupture of the Achilles tendon

    PubMed Central

    Lu, Jike; Maruo Holledge, Masumi

    2016-01-01

    A 59-year-old man fell off a 60-cm-high step, with his ankle in a twisted position, and sustained a closed fracture of the medial malleolus, with an ipsilateral complete Achilles tendon (TA) rupture. The TA rupture was initially missed but diagnosed by ultrasound examination, 2 weeks post-operatively. The ankle fracture was diagnosed from routine radiographs. Such a combination of injuries has been reported infrequently in the literature, but significant similarities have been described in the mechanism of injury and fracture patterns. Nevertheless, three of five reported cases with combined medial malleolus fractures were initially misdiagnosed. PMID:27141047

  2. Post traumatic osteoma of tibial insertion of medial collateral ligament of knee joint

    PubMed Central

    Shanker, V. S.; Gadikoppula, S.; Loeffler, M. D.

    1998-01-01

    Two cases are presented of post traumatic para-articular osteoma developing at the site of tibial attachment of the medial collateral ligament of knee joint. These occurred after injuries sustained while playing football and in one case the ossified mass was treated with surgical excision for unresolved symptoms after conservative measures. A comparison is made with Pellegrini Stieda disease, which is a similar affection of the femoral insertion of the medial ligament of the knee joint. 




 PMID:9562171

  3. Perforator arteries of the medial upper arm: anatomical basis of a new flap donor site.

    PubMed

    Perignon, D; Havet, E; Sinna, R

    2013-01-01

    The development of perforator flaps' concept based on knowledge on vascular anatomy of the skin represents a major improvement in reconstructive surgery. Succeeding description about vascular territories and anatomical basics of the main donor sites, the study of hidden donor sites, such as medial upper arm, constitutes a new step and an additional refinement. 20 upper limbs of 10 fresh adult cadavers were studied with colored latex injections. The origin and distribution of the perforator arteries of the superior ulnar collateral artery and the brachial artery were investigated. We have noted constant perforator arteries and described the limits of vascular territories of the medial upper arm.

  4. Editorial Commentary: Is Medial-Side Repair Indicated in the Treatment of Multiligament Knee Injuries?

    PubMed

    Marx, Robert G

    2016-09-01

    Multiligament knee injuries are heterogenous and demand individualized treatment. In addition to the complexity of the injury, factors such as the timing and type of surgery are also crucial to patient outcomes. In a case series, patients who underwent medial-side repair had inferior patient-reported outcomes compared with those who had medial reconstruction or lateral surgery. Interestingly, patients with common peroneal nerve injury did not have inferior outcomes, probably because of the lack of sensitivity of rating scales to measure nerve-related disability. In view of the complexity and heterogeneity of these injuries, the above-mentioned findings may not be generalizable to all patients.

  5. Treatment of the lacrimal excretory system after resection of medial canthal and eyelid tumors.

    PubMed

    Older, J J

    1979-06-01

    A simplified method of lacrimal excretory system repair is presented. If part of a canaliculus is resected during removal of an eyelid tumor, the remaining section of the canaliculus can be exteriorized to the lacrimal lake. A silicone tube is threaded into the canaliculus and allowed to remain in place for one to two weeks. If both canaliculi and the common canaliculus are removed during resection for a medial canthal tumor, a silicone tube can be threaded into the nasolacrimal duct and brought out the area of the medial canthal angle. Conjunctiva which is wrapped around the tube can then form a new drainage canal into the remainder of the lacrimal excretory system.

  6. Mechanism of the Rapid Effect of 17β -Estradiol on Medial Amygdala Neurons

    NASA Astrophysics Data System (ADS)

    Nabekura, Junichi; Oomura, Yutaka; Minami, Taketsugu; Mizuno, Yuji; Fukuda, Atsuo

    1986-07-01

    The mechanism by which sex steroids rapidly modulate the excitability of neurons was investigated by intracellular recording of neurons in rat medial amygdala brain slices. Brief hyperpolarization and increased potassium conductance were produced by 17β - estradiol. This effect persisted after elimination of synaptic input and after suppression of protein synthesis. Thus, 17β -estradiol directly changes the ionic conductance of the postsynaptic membrane of medial amygdala neurons. In addition, a greater proportion of the neurons from females than from males responded to 17β -estradiol.

  7. Indications for the microvascular medial femoral condylar flap in craniomaxillofacial surgery.

    PubMed

    Thiele, Oliver Christian; Kremer, Thomas; Kneser, Ulrich; Mischkowski, Robert Andreas

    2014-07-01

    The medial femoral condylar flap makes it possible to reconstruct bone, cartilage, and skin, but elongation of the pedicle is usually required to bridge the distances to the vascular connections in the neck. The indications in the maxillofacial area include reconstruction of the temporomandibular joint (TMJ), pseudarthrosis of the jaws, osteonecrosis of the jaws and skull, and augmentation of bone in irradiated or otherwise compromised tissue. If small bony defects require safe and reliable osseous, osteochondral, or osteocutaneous reconstruction, the medial femoral condylar flap can be used to fill the gap between small avascular, and larger microvascular, bone transplants.

  8. The weak measurement process and the weak value of spin for metastable helium 23S1

    NASA Astrophysics Data System (ADS)

    Monachello, Vincenzo; Barker, Peter; Flack, Robert; Hiley, Basil

    2016-05-01

    An experiment is being designed and constructed in order to measure the weak value of spin for an atomic system. The principle of the ``weak measurement'' process was first proposed by Aharonov, Albert and Vaidman, and describes a scenario in which a system is weakly coupled to a pointer between well-defined pre- and post-selected states. This experiment will utilise a pulsed supersonic beam of spin-1 metastable Helium (He*) atoms in the 23S1 state. The spin of the pre-selected He* atoms will be weakly coupled to its centre-of-mass. During its flight, the atomic beam will be prepared in a desired quantum state and travel through two inhomogeneous magnets (weak and strong) which both comprise the ``weak measurement'' process. The deviation of the post-selected ms = + 1 state as measured using a micro-channel plate, phosphor screen and CCD camera setup will allow for the determination of the weak value of spin. This poster will report on the methods used and the experimental realisation.

  9. Weak Gravitatational Lensing by Illustris-1 Galaxies

    NASA Astrophysics Data System (ADS)

    Brainerd, Tereasa G.; Koh, Patrick H.

    2016-06-01

    We compute the weak gravitational lensing signal of isolated, central galaxies obtained from the z=0.5 timestep of the ΛCDM Illustris-1 simulation. The galaxies have stellar masses ranging from 9.5 ≤ log10(M*/Msun) ≤ 11.0 and are located outside cluster and rich group environments. Although there is local substructure present in the form of small, luminous satellite galaxies, the central galaxies are the dominant objects within the virial radii (r200), and each central galaxy is at least 5 times brighter than any other luminous galaxy within the friends-of-friends halo. We compute the weak lensing signal within projected radii 0.05 < rp/r200 < 1.5 and investigate the degree to which the weak lensing signal is anisotropic. Since CDM halos are non-spherical, the weak lensing signal is expected to be anisotropic; however, the degree of anisotropy that is observed depends upon the symmetry axes that are used to define the geometry. The anisotropy is expected to be maximized when the major axis of the projected dark matter mass distribution is used to define the geomety. In practice in the observed universe, one must necessarily use the projected distribution of the luminous mass to define the geometry. If mass and light are not well-aligned, this results in a suppression of the weak lensing anistropy. Our initial analysis shows that the ellipticity of the projected dark matter halo is uncorrelated with the ellipticity of the projected stellar mass. That is ɛhalo ≠ f × ɛlight, where f is a constant multiplicative factor. In addition, in projection on the sky, the major axis of the dark matter mass is offset from that of the stellar mass by ˜40o on average. On scales rp ≤ 0.15 r200, the weak lensing anisotropy obtained when using the stellar mass to define the geometry is of order 7% and agrees well with the anisotropy obtained when using the dark matter mass to define the geometry. On scales rp ˜ r200, the anisotropy obtained when using the stellar mass to

  10. Weak gravitational lensing theory and data analysis

    NASA Astrophysics Data System (ADS)

    Hirata, Christopher Michael

    2005-12-01

    This thesis describes methodology for analysis of weak gravitational lensing data. Weak lensing, i.e. the perturbative distortion of the images of distant objects by the gravitational deflection of light, is an important tool for understanding the distribution of matter in the universe. This is interesting because a number of extentions to the standard cosmological model, including dynamical dark energy and neutrino masses, affect the growth of structure and hence may be detectable using weak lensing. Studies of weak lensing are also motivated by lensing's ability to affect the modes in the cosmic microwave background (CMB) polarization that are sensitive to primordial gravitational waves. Both lensing of galaxies and lensing of the CMB are considered here. The section devoted to galaxies is principally concerned with measuring the lensing-induced shape distortions from galaxy images in the Sloan Digital Sky Survey (SDSS), although the methodology will be applicable to future projects. We investigate in detail the problem of separating lensing from other shape distortions such as those induced by the atmosphere, the telescope, and photon Poisson noise. Since the intrinsic shapes of observed galaxies are not known, weak lensing observations always attempt some sort of statistical averaging over galaxies that presumably have independent orientations. We investigate the extent to which this process "averages down" the intrinsic shapes and identify a new type of bias that can affect the weak lensing power spectrum. Selection biases are considered and their importance in SDSS estimated. We present some recent cosmological results using the SDSS analysis, including new upper limits on the neutrino mass. Lensing of the CMB has not yet been detected, nevertheless several experiments are being built that should have the sensitivity to see it. The statistical problem of extracting lensing information from the distortion of the CMB anisotropy is considered, and in the case of

  11. Experimental observation of weak non-Markovianity

    PubMed Central

    Bernardes, Nadja K.; Cuevas, Alvaro; Orieux, Adeline; Monken, C. H.; Mataloni, Paolo; Sciarrino, Fabio; Santos, Marcelo F.

    2015-01-01

    Non-Markovianity has recently attracted large interest due to significant advances in its characterization and its exploitation for quantum information processing. However, up to now, only non-Markovian regimes featuring environment to system backflow of information (strong non-Markovianity) have been experimentally simulated. In this work, using an all-optical setup we simulate and observe the so-called weak non-Markovian dynamics. Through full process tomography, we experimentally demonstrate that the dynamics of a qubit can be non-Markovian despite an always increasing correlation between the system and its environment which, in our case, denotes no information backflow. We also show the transition from the weak to the strong regime by changing a single parameter in the environmental state, leading us to a better understanding of the fundamental features of non-Markovianity. PMID:26627910

  12. From weak discontinuities to nondissipative shock waves

    SciTech Connect

    Garifullin, R. N. Suleimanov, B. I.

    2010-01-15

    An analysis is presented of the effect of weak dispersion on transitions from weak to strong discontinuities in inviscid fluid dynamics. In the neighborhoods of transition points, this effect is described by simultaneous solutions to the Korteweg-de Vries equation u{sub t}'+ uu{sub x}' + u{sub xxx}' = 0 and fifth-order nonautonomous ordinary differential equations. As x{sup 2} + t{sup 2} {yields}{infinity}, the asymptotic behavior of these simultaneous solutions in the zone of undamped oscillations is given by quasi-simple wave solutions to Whitham equations of the form r{sub i}(t, x) = tl{sub i} x/t{sup 2}.

  13. Weak cosmic censorship: as strong as ever.

    PubMed

    Hod, Shahar

    2008-03-28

    Spacetime singularities that arise in gravitational collapse are always hidden inside of black holes. This is the essence of the weak cosmic censorship conjecture. The hypothesis, put forward by Penrose 40 years ago, is still one of the most important open questions in general relativity. In this Letter, we reanalyze extreme situations which have been considered as counterexamples to the weak cosmic censorship conjecture. In particular, we consider the absorption of scalar particles with large angular momentum by a black hole. Ignoring back reaction effects may lead one to conclude that the incident wave may overspin the black hole, thereby exposing its inner singularity to distant observers. However, we show that when back reaction effects are properly taken into account, the stability of the black-hole event horizon is irrefutable. We therefore conclude that cosmic censorship is actually respected in this type of gedanken experiments.

  14. Shock Wave Dynamics in Weakly Ionized Plasmas

    NASA Technical Reports Server (NTRS)

    Johnson, Joseph A., III

    1999-01-01

    An investigation of the dynamics of shock waves in weakly ionized argon plasmas has been performed using a pressure ruptured shock tube. The velocity of the shock is observed to increase when the shock traverses the plasma. The observed increases cannot be accounted for by thermal effects alone. Possible mechanisms that could explain the anomalous behavior include a vibrational/translational relaxation in the nonequilibrium plasma, electron diffusion across the shock front resulting from high electron mobility, and the propagation of ion-acoustic waves generated at the shock front. Using a turbulence model based on reduced kinetic theory, analysis of the observed results suggest a role for turbulence in anomalous shock dynamics in weakly ionized media and plasma-induced hypersonic drag reduction.

  15. Intensive care unit-acquired weakness.

    PubMed

    Horn, J; Hermans, G

    2017-01-01

    When critically ill, a severe weakness of the limbs and respiratory muscles often develops with a prolonged stay in the intensive care unit (ICU), a condition vaguely termed intensive care unit-acquired weakness (ICUAW). Many of these patients have serious nerve and muscle injury. This syndrome is most often seen in surviving critically ill patients with sepsis or extensive inflammatory response which results in increased duration of mechanical ventilation and hospital length of stay. Patients with ICUAW often do not fully recover and the disability will seriously impact on their quality of life. In this chapter we discuss the current knowledge on the pathophysiology and risk factors of ICUAW. Tools to diagnose ICUAW, how to separate ICUAW from other disorders, and which possible treatment strategies can be employed are also described. ICUAW is finally receiving the attention it deserves and the expectation is that it can be better understood and prevented.

  16. Universal portfolios generated by weakly stationary processes

    NASA Astrophysics Data System (ADS)

    Tan, Choon Peng; Pang, Sook Theng

    2014-12-01

    Recently, a universal portfolio generated by a set of independent Brownian motions where a finite number of past stock prices are weighted by the moments of the multivariate normal distribution is introduced and studied. The multivariate normal moments as polynomials in time consequently lead to a constant rebalanced portfolio depending on the drift coefficients of the Brownian motions. For a weakly stationary process, a different type of universal portfolio is proposed where the weights on the stock prices depend only on the time differences of the stock prices. An empirical study is conducted on the returns achieved by the universal portfolios generated by the Ornstein-Uhlenbeck process on selected stock-price data sets. Promising results are demonstrated for increasing the wealth of the investor by using the weakly-stationary-process-generated universal portfolios.

  17. The Strict-Weak Lattice Polymer

    NASA Astrophysics Data System (ADS)

    Corwin, Ivan; Seppäläinen, Timo; Shen, Hao

    2015-08-01

    We introduce the strict-weak polymer model, and show the KPZ universality of the free energy fluctuation of this model for a certain range of parameters. Our proof relies on the observation that the discrete time geometric -TASEP model, studied earlier by Borodin and Corwin, scales to this polymer model in the limit . This allows us to exploit the exact results for geometric -TASEP to derive a Fredholm determinant formula for the strict-weak polymer, and in turn perform rigorous asymptotic analysis to show KPZ scaling and GUE Tracy-Widom limit for the free energy fluctuations. We also derive moments formulae for the polymer partition function directly by Bethe ansatz, and identify the limit of the free energy using a stationary version of the polymer model.

  18. Mutual synchronization of weakly coupled gyrotrons

    SciTech Connect

    Rozental, R. M.; Glyavin, M. Yu.; Sergeev, A. S.; Zotova, I. V.; Ginzburg, N. S.

    2015-09-15

    The processes of synchronization of two weakly coupled gyrotrons are studied within the framework of non-stationary equations with non-fixed longitudinal field structure. With the allowance for a small difference of the free oscillation frequencies of the gyrotrons, we found a certain range of parameters where mutual synchronization is possible while a high electronic efficiency is remained. It is also shown that synchronization regimes can be realized even under random fluctuations of the parameters of the electron beams.

  19. Measuring neutrino masses with weak lensing

    SciTech Connect

    Wong, Yvonne Y. Y.

    2006-11-17

    Weak gravitational lensing of distant galaxies by large scale structure (LSS) provides an unbiased way to map the matter distribution in the low redshift universe. This technique, based on the measurement of small distortions in the images of the source galaxies induced by the intervening LSS, is expected to become a key cosmological probe in the future. We discuss how future lensing surveys can probe the sum of the neutrino masses at the 0 05 eV level.

  20. Electrodiagnostic approach to patients with weakness.

    PubMed

    Dillingham, Timothy R

    2003-05-01

    Electrodiagnosis has a key role in the evaluation of patients presenting with weakness. The electrodiagnostician should maintain a broad inclusive differential diagnosis and tailor the examination using a sound conceptual framework. A clear understanding of what is normal provides the proper foundation upon which to judge electrodiagnostic findings. Many peripheral neuromuscular conditions manifest themselves in characteristic ways on NEE and nerve conduction testing, making them identifiable to the skilled electrodiagnostic medicine consultant.