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At least 685 records · Page 38Linked to original sources
PubMed2026

Quantifying the control laws governing terminal attack in lions.

Intercepting an evasive, maneuvering target is among the most computationally demanding tasks a predator performs: in the terminal phase of a chase, it must continuously convert sensory information about the target into steering and speed commands, subject to its own biomechanical limits. How terrestrial predators solve this in real time has remained difficult to quantify. Here, we combine drone videography with AI-based markerless pose estimation to reconstruct the kinematics of 67 lion (Panthera leo) attacks on a mechanized lure programmed to move unpredictably. Lion steering is described by a combination of proportional navigation and proportional pursuit, which is a mixed guidance law previously identified only in the aerial pursuit of Harris's hawks (Parabuteo unicinctus), and speed is regulated within a defined kinematic envelope during turns, which declines at close range where the cost of overshooting is greatest. These findings reveal shared guidance principles across aerial and terrestrial pursuit, thus providing a quantitative framework for comparing pursuit strategies across species.

computational ethology↗
PubMed2005

Visual field defects in deformational posterior plagiocephaly.

PURPOSE: We sought to determine whether visual field abnormalities occur in infants with deformational posterior plagiocephaly and to assess whether there is a relationship between the severity and laterality of visual field abnormalities with the severity and laterality of skull deformity. METHODS: A retrospective chart review was performed on 40 consecutive infants with deformational posterior plagiocephaly. Each was tested with standardized binocular arc perimetry in the horizontal plane. Sixteen patients also had 3-dimensional computed tomography of the skull. Hemifield asymmetry of >/=20 degrees and/or a decrease in hemifield values by >/=20 degrees from established normal patients was considered abnormal. Visual field data from study patients was plotted against previously published normative data. Graphs comparing visual field defects and laterality to cranial asymmetry also were generated. RESULTS: Thirty-five percent of infants with deformational posterior plagiocephaly had constriction of one or both hemifields by at least 20 degrees from established normal patients. Hemifield asymmetry of 20 degrees or more was found in 17.5% of infants tested. There was a significant difference in the worse hemifield values measured in each patient and the standard visual fields obtained from normative data ( P = 0.036). There was no correlation between the laterality of the visual fields to the laterality of the defects. A correlation between severity of hemifield constriction and % asymmetry on computed tomography was noted ( P = 0.209). CONCLUSIONS: Deformational posterior plagiocephaly may affect visual field development but neither the laterality nor the severity of skull deformity is predictive of the severity of visual field defects.

Humans↗
PubMed2025

Pioneer in Molecular Biology: Conformational Ensembles in Molecular Recognition, Allostery, and Cell Function.

In 1978, for my PhD, I developed the efficient O(n3) dynamic programming algorithm for the-then open problem of RNA secondary structure prediction. This algorithm, now dubbed the "Nussinov algorithm", "Nussinov plots", and "Nussinov diagrams", is still taught across Europe and the U.S. As sequences started coming out in the 1980s, I started seeking genome-encoded functional signals, later becoming a bioinformatics trend. In the early 1990s I transited to proteins, co-developing a powerful computer vision-based docking algorithm. In the late 1990s, I proposed the foundational role of conformational ensembles in molecular recognition and allostery. At the time, conformational ensembles and free energy landscapes were viewed as physical properties of proteins but were not associated with function. The classical view of molecular recognition and binding was based on only two conformations captured by crystallography: open and closed. I proposed that all conformational states preexist. Proteins always have not one folded form-nor two-but many folded forms. Thus, rather than inducing fit, binding can work by shifting the ensembles between states, and this shifting, or redistributing the ensembles to maintain equilibrium, is the origin of the allosteric effect and protein, thus cell, function. This transformative paradigm impacted community views in allosteric drug design, catalysis, and regulation. Dynamic conformational ensemble shifts are now acknowledged as the origin of recognition, allostery, and signaling, underscoring that conformational ensembles-not proteins-are the workhorses of the cell, pioneering the fundamental idea that dynamic ensembles are the driving force behind cellular processes. Nussinov was recognized as pioneer in molecular biology by JMB.

Molecular Biology↗
PubMed2005

Intraosseous lipoma of the body of the sphenoid bone.

A case of intraosseous lipoma arising from the body of the sphenoid bone with intrasellar and suprasellar components is reported. This is the first report of this uncommon tumour occurring in an atypical intracranial site, producing the locally invasive and pressure effects of visual failure and hypopituitarism. The diagnosis was based on computed tomographic (CT) and magnetic resonance (MR) imaging with histological confirmation following frontal craniotomy.

Female↗
PubMed2000

Pachymeningitis with pseudo-Foster Kennedy syndrome.

PURPOSE: To report a case of pachymeningitis with pseudo-Foster Kennedy syndrome in a patient who was positive for perinuclear antineutrophil cytoplasmic antibody. METHODS: Case report. A 44-year-old man was examined for headache and diplopia. RESULTS: Left eye showed limitation of abduction. Ocular fundus, computed tomography (CT), and magnetic resonance imaging (MRI) of the head and orbits were normal. The diplopia subsided spontaneously. Six months later, he noticed sudden visual loss in the left eye. The left eye showed optic disk atrophy and episcleritis, and the right eye showed papilloedema. Computed tomography and MRI exhibited thickened dura mater. Serum perinuclear antineutrophil cytoplasmic antibody level was highly increased. CONCLUSION: Pachymeningitis with ocular involvement sometimes requires repeated CT or MRI for diagnosis. This disorder may be caused by microvasculitis.

Adult↗
PubMed2002

Primary adrenal lymphoma with choroidal metastases.

PURPOSE: To describe a 71-year-old man with bilateral primary adrenal lymphoma with metastases to the choroid. DESIGN: Interventional case report. METHODS: A 71-year-old man presented with decreased visual acuity in his left eye secondary to an exudative retinal detachment. Abdominal computed tomography and percutaneous biopsy revealed non-Hodgkin large-cell lymphoma involving both adrenal glands. RESULTS: Ocular and adrenal lesions resolved after six cycles of chemotherapy with cytoxan, adriamycin, vincristine, and prednisone. Seven years after his initial diagnosis, the patient reported no recurrence of either ocular or systemic lymphoma. CONCLUSIONS: To our knowledge, this is the first case report of bilateral primary adrenal lymphoma with apparent metastases exclusively to the eye.

Adrenal Gland Neoplasms↗
PubMed1996

Choroidal neovascular membrane associated with optic nerve head drusen in a child.

PURPOSE: To illustrate the diagnosis, evaluation, and complications of pseudopapilledema in children. METHODS: We examined a 9-year-old boy who had suspected papilledema and a retinal mass. He had undergone neuroradiologic imaging at an outside facility. RESULTS: Clinical examination of the patient provided the diagnosis of optic nerve head drusen, pseudopapilledema, and a cicatrized choroidal neovascular membrane. Examination of the boy's parents disclosed optic nerve head drusen in the father. CONCLUSIONS: Choroidal neovascular membranes caused by optic nerve head drusen are uncommon in children. Clinical examination of the patient and family members, along with B-scan ultrasonography, can establish this cause. Neuroradiologic testing is unnecessary, and carries risk related to the need for sedation.

Calcinosis↗
PubMed1996

Advances in neuroimaging of the visual pathways.

PURPOSE: To provide a practical review for the ophthalmologist of advances in neuroimaging of the visual pathways. METHODS: We reviewed recent advances in computed tomography, magnetic resonance imaging, and angiography that are applicable to visual pathways imaging. RESULTS: For detailed ocular imaging, computed tomography complements ocular sonography for imaging of calcification, trauma, and masses. Magnetic resonance imaging may be helpful for localization and characterization of ocular masses in the setting of hemorrhage. For orbital imaging, computed tomography is most appropriate in the evaluation of suspected thyroid ophthalmopathy, infection, and trauma; otherwise, either computed tomography or magnetic resonance imaging is useful for detection and characterization of abnormality. For disorders affecting the sellar, retrochiasmal, and brainstem pathways, magnetic resonance imaging is the study of choice, except for acute hemorrhage, for which noncontrast computed tomography is preferable. Although magnetic resonance angiography has a role in the elective evaluation of cerebrovascular disease, conventional angiography is the definitive study for suspected aneurysm and for surgical planning. CONCLUSIONS: A practical approach for selection of the most appropriate imaging modalities by the ophthalmologist is suggested on the basis of the anatomic location and type of disease suspected.

Adult↗
PubMed1996

Attempted autoenucleation.

PURPOSE: A 24-year-old man had visual acuity of no light perception in the left eye after attempted autoenucleation. METHODS: An urgent lateral canthotomy was performed, followed by treatment with high-dose intravenous corticosteroids. RESULTS: Visual acuity improved to L.E.: 20/30. Visual field testing disclosed recovery of the central visual field with persistent arcuate visual field defects. CONCLUSION: Visual acuity of no light perception after attempted autoenucleation does not preclude the return of good visual acuity.

Adult↗
PubMed1990

Visual function improvement in patients with macroprolactinomas treated with bromocriptine.

We studied eight patients who had visual field defects secondary to prolactin-secreting macroadenomas and who had improved visual function with bromocriptine treatment without surgery or radiation. We recommend bromocriptine as a primary treatment for prolactin-secreting macroadenomas. If therapy is effective, continued regular neuro-ophthalmologic, endocrine, and imaging studies are necessary, because treatment with bromocriptine must be continued indefinitely.

Adult↗
PubMed1991

Visual recovery in patients with optic neuritis and visual loss to no light perception.

We reviewed the records of 151 patients with optic neuritis examined over an eight-year period. Of these patients, 12 developed visual acuity of no light perception during the first episode of optic neuritis in the affected eye. Eight of the 12 patients recovered visual acuity of 20/40 or better. Of these, five patients had visual acuity of 20/20 or better, one had visual acuity of 20/25, one had visual acuity of 20/30, and one had visual acuity of 20/40. Four of the 12 patients recovered peripheral visual fields but had dense central scotomas and visual acuity of less than 20/400. Dyschromatopsia persisted after visual recovery in 11 of 12 patients.

Adolescent↗
PubMed1994

Traumatic chiasmal syndrome associated with midline basilar skull fractures.

We studied two young males who had visual field defects consistent with optic chiasmal injury after blunt frontal head trauma. One patient also had a unilateral optic neuropathy. Long-term follow-up disclosed complete bi-temporal hemianopsias in these patients. Both patients had midline basilar skull fractures that traversed the midclivus through the sella turcica floor, dorsum sellae, and sphenoid sinus. Magnetic resonance images did not identify intrachiasmal hemorrhage as the cause of the visual field defect. We believe this fracture pattern, in conjunction with the magnetic resonance image findings, suggests tearing of the optic chiasm on a microscopic, if not macroscopic, scale as the cause of the complete bitemporal hemianopsia.

Accidents, Traffic↗
PubMed1995

Ophthalmic manifestations of Rathke's cleft cysts.

PURPOSE: We studied the neuro-ophthalmic features of patients with symptomatic Rathke's cleft cysts, to distinguish features of Rathke's cleft cysts from those of craniopharyngioma. METHODS: Eleven patients who had undergone surgery for symptomatic Rathke's cleft cysts in the Liverpool University Department of Neurological Science were identified from the records. Histopathologic analyses, clinical notes, and radiologic investigations were reviewed. RESULTS: Eight of the 11 patients initially had visual problems. Reduced visual acuity, visual field defect, or both, were detected in nine patients. Optic atrophy was observed in eight patients. Other initial features included headaches, epilepsy, and endocrine disturbance. All patients recovered from surgery, and an improvement in the visual acuity or visual field defect was noted in six patients. CONCLUSIONS: Symptomatic Rathke's cleft cysts often manifest as visual disturbance. Every effort to distinguish Rathke's cleft cysts from craniopharyngiomas should be made preoperatively. Rathke's cleft cysts only require limited surgical intervention, and radiotherapy is not necessary. Early recognition and treatment can lead to improvement in visual function.

Adolescent↗
PubMed1992

Congenital oculomotor nerve palsy, cerebellar hypoplasia, and facial capillary hemangioma.

We saw two infants with the unusual combination of oculomotor nerve palsy, facial capillary hemangioma, cerebellar hypoplasia, and apparent gaze palsy. Systematic imaging of children with congenital oculomotor nerve palsy may lead to the recognition of more associated neurologic abnormalities that are not clinically apparent, as was the case in our patients.

Capillaries↗
PubMed1992

Failure of metacontrol: breakdown in behavioural unity after lesion of the corpus callosum and inferomedial frontal lobes.

A right-handed man suffered aneurysmal haemorrhage with lesions of the genu and body of the corpus callosum and the inferomedial frontal lobes bilaterally (right more than left). He exhibited remarkable breakdown in behavioural unity characterized by conflict between the two sides of the body, actions inconsistent with verbalizations, and internal conflict over control of the left hand. A major feature of the deficit was its temporal variability. This is interpreted as reflecting intermittent failure of metacontrol processes, which are neural mechanisms for maintaining behavioural unity. Medial frontal structures and their interconnections through the corpus callosum appear particularly important in the maintenance of metacontrol.

Adult↗
PubMed1988

How long is a piece of string? A study of line bisection in a case of visual neglect.

We report a case of severe left visual neglect consequent upon extensive infarction in the territory of the right middle cerebral artery. A detailed analysis is given of the patient's performance on line bisection. The stimuli cover a wider range of lengths than is usually employed in such studies (11'' to 1''). The magnitude of the patient's rightward displacement of his transections is linearly related to the length of the stimulus line, such that the longer the line, the greater the left 'neglect'. At line length 2'', the patient's transections are relatively accurate, and at length 1'', the transections cross the objective midpoint to give a reliable left displacement (= 'right neglect'). On some occasions, these latter transections are placed beyond the leftmost point of the stimulus line. We interpret the data in terms of two constructs: (a) an 'attentional boundary' placed slightly to the left of the objective midline; (b) 'representational completion' that extends to the attentional boundary.

Adult↗