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PubMed2003

Botulinum A toxin (BOTOX) in the lower eyelid: dose-finding study.

BACKGROUND: Botulinum toxin type A (BTX-A, BOTOX) is an excellent therapeutic option for hyperkinetic facial lines. It improves wrinkles by relaxing the muscles of facial expression, which underlie the rhytids. Periocular wrinkles such as lateral orbital rhytids respond well to treatment. BOTOX can be used in the lower eyelid to improve wrinkles and widen the eye. OBJECTIVE: To determine whether there is additional benefit in using more than 2 U of BTX-A to improve infraorbital wrinkles and widen the eye. METHODS: Nineteen women had BTX-A injected into the orbicularis oculi muscle. Eleven women had 4 U injected into the lower eyelid bilaterally, 3 mm below the ciliary margin, and 12 U of BTX-A injected into one lateral orbital (crow's feet) area. Eight patients had 8 U injected bilaterally into the lower eyelid and 12 U placed unilaterally into the crow's feet. Physicians and patients independently evaluated the degree of improvement (grade 3=dramatic improvement, grade 2=moderate improvement, grade 1=mild improvement, and grade 0=no improvement). Single investigator analysis was used to measure, in actual millimeters, the amount of increase in palpebral aperture. Side effects were noted. RESULTS: Improvement was noted in lower eyelid wrinkles by both physicians and patients at both dose groups. When only the lower lid was injected, patients reported an improvement of 1.18 with 4 U and a grade of 1.63 with 8 U. When both the lower eyelid the lateral orbital area were treated, an improvement of 1.73 was reported with 4 U and a grade of 2.25 reported with 8 U in the lower eyelid. Physician evaluations had grades of 1.85 for 4 U alone and 1.85 with 8 U alone. Grades of 2.35 and 2.25 were obtained for 4 U plus 12 U and 8 U plus 12 U, respectively. An increase in palpebral aperture (IPA) occurred in all subjects. Subjects who received 4 U in the lower eyelid alone had a 1.8-mm IPA at rest and a 2.6-mm increase at full smile. Subjects who received 8 U of BTX-A alone in the lower lid had an IPA of 2.2 mm at rest and 2.9 mm at full smile. Eyes treated with 12 U in the bilateral orbital area plus 4 U in the lower eyelid had an IPA of 2.2 at rest and 4.5 mm at full smile. Those treated with 8 U in the lower lid plus the crow's feet had an IPA of 1.5 at rest and 4.0 at full smile. Side effects increased with dosage, with eight of eight subjects in the 8-U dose groups reporting bothersome side effects such as lower eyelid edema and incomplete sphincter function. CONCLUSION: A dose-response curve is seen with increasing doses of BTX-A used in the lower eyelid. Treatment of the lateral orbital area in combination with the lower lid produces a synergistic response at lower doses, but at higher doses, a plateau effect is suggested. Although increasing doses of BTX-A increases eye widening, unattractive results and side effects are seen at higher doses. The authors recommend that lower 2- or 4-U doses of BTX-A be used in the lower eyelid and specifically discuss techniques.

Adolescent↗
PubMed1993

Times to extinction for small populations of large birds.

A major practical problem in conservation biology is to predict the survival times-"lifetimes"-for small populations under alternative proposed management regimes. Examples in the United States include the 'Alala (Hawaiian Crow; Corvus hawaiiensis) and Northern Spotted Owl (Strix occidentalis caurina). To guide such decisions, we analyze counts of all crow, owl, and hawk species in the most complete available data set: counts of bird breeding pairs on 14 European islands censused for 29-66 consecutive years. The data set yielded 129 records for analysis. We define the population ceiling as the highest number of breeding pairs observed from colonization to extinction, within a consecutive series of counts for a given species on a given island. The resulting distributions of population lifetimes as a function of population size prove to be highly skewed: most small populations disappear quickly, but a few last for a long time. Median (i.e., 50th percentile) lifetimes are calculated as only 1-5 yr for hawk, owl, and crow populations with ceilings of one or two breeding pairs. As expected if demographic accidents are the main cause of extinction for small populations, lifetimes rise by a factor of 3-4 for each additional pair up to three pairs. They rise more slowly thereafter. These observations suggest that lifetimes of the 'Alala (now reduced to about three pairs in the wild), and of populations of Northern Spotted Owl in the smallest forest fragments, will be short unless active management is implemented.

Journal Article↗
PubMed2006

Age-related changes of the cutaneous microcirculation in vivo.

BACKGROUND: The architectural frameworks of the skin microcirculation are rather complex and change continuously with aging. But these changes are yet poorly documented in vivo. OBJECTIVES: Using non-invasive methods belonging to the field of biometrology, the study aimed to investigate quantitatively the changes of the cutaneous microvasculature in different anatomic sites with age. METHODS: Measurements were performed on crow's feet, forehead, volar forearm and dorsum of hand in 50 women (aged 20-74 years who consisted of 10 probands in each live decades). The superficial vascular plexus was scanned by videocapillaroscopy and assessed with the software Capilab Toolbox. The subpapillary vascular plexus was explored with laser Doppler flowmetry. The skin color a* was analyzed by chromametry. RESULTS: A marked site and age effect on the skin microcirculation has been demonstrated. The density of capillary loops in the eldest group decreased by about 40-70% compared with the youngest group whereas the vascular length increased by 35-156%. The capillary density in the back of the hand was 4 times higher than in the crow's feet. The vascular length in the crow's feet was 3 times longer than in the back of the hand. Both blood flow and skin redness (a*) increased also with age. CONCLUSION: Both morphology and quantification of the cutaneous microvasculature showed changes with site and age. Videocapillaroscopy associated to an image processing and laser Doppler flowmetry revealed different vascular layers. So the combination of both instruments offers an easy way to observe the architectural frameworks in vivo.

Adult↗
PubMed1994

[Positive and negative symptoms in schizophrenia: a current overview].

The purpose of this article is to summarize the results of studies examining the validity of the positive and negative sub-types of schizophrenia as proposed by Crow. The authors summarized Crow's model's predictions in the form of 12 research questions and examined whether its predictions were confirmed. The following predictions are generally confirmed by the data collected: (i) it is possible to measure negative symptoms with accuracy; (ii) the negative symptoms predict a deterioration; (iii) the negative symptoms are generally correlated with overall cognitive deficits; (iv) each dimension appears to have distinct neurobiological substrata. However, several elements of the Crow model are not supported by the data collected. Among the necessary modifications, the most important are as follows: (i) it appears more productive to conceive of the negative symptoms as distinct dimensions, rather than distinct diseases; (ii) at least three dimensions exist for describing the symptoms of schizophrenia; (iii) the negative symptoms are not necessarily intrinsic to the schizophrenic process, and they may be due to other causes; (iv) the negative symptoms are not necessarily irreversible, and can be improved under ataractics; (v) the positive symptoms, in particular those relating to disorganization, can also be correlated with cognitive deficits.

Antipsychotic Agents↗
PubMed1998

Charcot restraint orthotic walker.

Five patients (three with insulin dependent diabetes mellitus (IDDM), one with noninsulin dependent diabetes mettlitus (NIDDM), and one with hereditary sensorimotor neuropathy (HSMN)) with stage 1 Charcot's neuroarthropathy involving the midfoot and or subtalar and ankle joints were fitted with a Charcot restraint orthotic walker (CROW). The rationale for this orthotic management was to maintain a plantigrade foot for ambulation and to protect the joints and skin by the uniform transfer or distribution of weight over the foot until the time when the pathology reached the stage of coalescence. The patients were able to fully bear weight and to ambulate with the CROW. All patients noted varying measures of improvement in symptoms and function at an average 12-month follow-up. The CROW is a useful orthosis in the armamentarium for treating neuroarthropathy of the pedal joints.

Adult↗
PubMed2003

Systematic design of single-mode coupled-resonator optical waveguides in photonic crystals.

By establishing a direct relation between the dispersion and the field profile of a coupled-resonator optical waveguide (CROW) and those of its constituent cavities, we present a systematic method for the design of a single-mode CROW and for control of its dispersion. The procedure includes the design of a single-mode cavity and control of its frequency by engineering its structure. Then, by chaining these cavities in the proper direction and at an appropriate distance, we achieve the desired dispersion for the CROW.

Journal Article↗
PubMed2005

Single-center, double-blind, randomized study to evaluate the efficacy of 4% lidocaine cream versus vehicle cream during botulinum toxin type A treatments.

BACKGROUND: Botulinum toxin type A (BTX-A) injections are overwhelmingly safe and effective treatment in cosmetic treatment, but some patients are apprehensive about pain associated with injection. OBJECTIVE: To determine whether preprocedural application of lidocaine 4% topical anesthetic cream to the injection site will reduce pain on injection of BTX-A for the treatment of crow's feet. METHODS: Twenty-four participants receiving bilateral injections for crow's feet were enrolled. Subjects were randomized to one of four study groups. Prior to BTX-A injection, group 1 (n = 6) received lidocaine 4% cream on the right side of the face and vehicle cream on the left side of the face; group 2 (n = 6) received vehicle cream on the right side and lidocaine 4% on the left side; group 3 (n = 6) received lidocaine 4% on both sides; and group 4 (n = 6) received vehicle cream on both sides. RESULTS: We observed a statistically significant reduction in subject-reported procedural pain in participants pretreated with lidocaine 4% on both sides of the face compared with controls. CONCLUSION: Lidocaine 4% cream is effective in reducing the pain associated with BTX-A injection for crow's feet. We encourage further study to clarify the optimal use of topical anesthetics in the practice of cosmetic dermatology.

Administration, Topical↗
PubMedDate not supplied

West Nile virus surveillance in Connecticut in 2000: an intense epizootic without high risk for severe human disease.

In 1999, Connecticut was one of three states in which West Nile (WN) virus actively circulated prior to its recognition. In 2000, prospective surveillance was established, including monitoring bird deaths, testing dead crows, trapping and testing mosquitoes, testing horses and hospitalized humans with neurologic illness, and conducting a human seroprevalence survey. WN virus was first detected in a dead crow found on July 5 in Fairfield County. Ultimately, 1,095 dead crows, 14 mosquito pools, 7 horses, and one mildly symptomatic person were documented with WN virus infection. None of 86 hospitalized persons with neurologic illness (meningitis, encephalitis, Guillain-Barré-like syndrome) and no person in the seroprevalence survey were infected. Spraying in response to positive surveillance findings was minimal. An intense epizootic of WN virus can occur without having an outbreak of severe human disease in the absence of emergency adult mosquito management.

Animals↗
PubMed1998

Coxiellosis in domestic and wild birds from Japan.

Serological evidence of infection with Coxiella burnetii was found in 41 (2%) of 1,951 domestic birds and in 167 (19%) of 863 wild birds from 17 and 5 prefectures in Japan, respectively, by microagglutination (MA) test. The bacteriological evidence of the infection was found in 17 (41%) of 41 domestic birds and 37 (22%) of 167 wild birds by the nested polymerase chain reaction (PCR). In addition, C. burnetii was isolated from five each of serum, spleen and fecal specimens from five jungle crows (Corvus macrorhynchos) (whose sera were positive by both the MA test and PCR) by inoculating laboratory mice. Domestic quail (Coturnix coturnix japonica) (3%), domestic muscovy ducks (Cairina moschata) (3%), domestic chickens (2%), domestic mallards (Anas platyrhynchos domesticus) (2%), carrion crows (Corvus corone) (37%), jungle crows (35%), and wild rock doves (Columba livia) (6%) showed serologic evidence of experience with C. burnetii. There was a tendency for a high prevalence among birds living and/or feeding in close proximity to infected livestock. This suggests that these birds are one of the less important links in maintaining the whole cycle of C. burnetii infection.

Agglutination Tests↗
PubMed2001

[A case of polyneuropathy associated with increased levels of vascular endotherial growth factor (VEGF) insera].

A 54-year-old woman began to notice numbness and motor weakness in the lower extremities in July 1999. These symptoms rapidly progressed and she could not walk any more. When she admitted to our hospital, she showed peripherally dominant, moderate motor weakness, drop foot and loss of superficial and deep sensation in the lower extremities, but only slight weakness in the hands. Cranial nerves were intact. Deep tendon reflexes were all absent. Nerve conduction velocities were reduced and cerebrospinal fluid protein was elevated. VEGF was greatly increased in serum (1,850 pg/ml), which has been found to be increased exclusively in patients with Crow-Fukase syndrome. Many characteristic manifestations of the syndrome except polyneuropathy are well explained to be resulted from the abnormal production of VEGF. She did not, however, exhibit any constellation of Crow-Fukase syndrome such as edema, skin change, organomegaly, bone lesions or M-proteinemia. Steroid therapy improved her symptoms and lessened the levels of serum VEGF and cerebrospinal fluid protein. This case indicated that overproduction of VEGF could induce polyneuropathy rather than the other symptoms of Crow-Fukase syndrome, and that a polyneuropathy associated with increased VEGF might exist.

Endothelial Growth Factors↗
PubMed2003

Chiari pelvic osteotomy in the management of developmental hip dysplasia: a long term follow-up.

PURPOSE OF THE STUDY: Developmental hip dysplasia in adults causes several anatomical changes which can lead to premature and progressive secondary osteoarthritis. The principle of Chiari osteotomy is the medialisation of the subluxated femoral head. This improves the biomechanics of the hip. The goal of the study was to assess the long term results of Chiari innominate osteotomy. MATERIAL: The authors evaluated 130 hips after Chiari ostetomy from 230 patients operated on in the sears 1969-1985 at the Ist Orthopaedic Department of St. Anna University Hospital in Brno, Czech Republic. The mean follow-up was 22.3 years (15-30) and there were 125 women and 5 men. The average age at the time of the procedure was 29 years (15-52). METHODS: We assessed the Harris hip score, daily activities, the length of the improvement after the procedure and asked the patients if they would undergo again the same procedure. We also assessed the CE angle, the Sharp angle, AHI index, the CCD angle, the Shenton's line, Crowe type of dysplasia, the shape of the femoral head and Kellgren-Lawrence grades of the osteoarthritis. There were 5 types of hip dysplasia in the study: coxa valga subluxans, coxa valga luxans, coxa plana brevis, coxa magna and severe deformity of the femoral head. There were 26 cases of hip dysplasia alone, 87 cases of hip dysplasia with a subluxation of the femoral head and 13 cases of dysplasia with a false acetabulum. We searched for the factors influencing the end results. We measured the medial shift of the distal pelvic fragment and the level of the osteotomy. RESULTS: The mean nmedial shift of the distal fragment was 22 mm e.g. 48.6%. There was a correct level of the osteotomy in 113 patients. Radiological features improved: the CE angle (-12 degrees to +37.2 degrees), the Sharp angle (48 degrees to 41 degrees), AHI index (51 to 96.3%). The Harris hip score improved from 42 points to 67.5 points an average. 65 patients have been satisfied with the procedure, 49 were partialy satisfied and 16 were not satisfied. There were 80 patients without any other procedure (the first group) and there were 50 patients with the conversion to total hip replacement at the time of the latest follow-up (the second group). The mean age at the time of the operation was 24.2 years in the first group and 33.7 years in the second group. 62 patients in the first group had no osteoarthritis or grade 1 osteoarthritis at the time of the operation. 43 patients in the second group had grade 2 or 3 osteoarthritis at the time of the operation. The favourable results of the operation lasted 17.6 years in the first group and 11.1 years in the second group. The time between Chiari osteotomy and the conversion to total hip replacement was 12.2 years in the second group. DISCUSSION: The favourable factors are the age up to 30 years, no osteoarthritis or the grade 1 of osteoarthritis, coxa valga subluxans of Crowe type I and type II of hip dysplasia with a normal Shenton line, the spherical and ovoid shape of the femoral head, the correct level of the osteotomy and full coverage of the femoral head (medial shift 40%). The unfavourable factors for long term results were older age (over 35 years) of the patient at the time of the operation, grade 2 and 3 of osteoarthritis, severe deformity of the femoral head, Crowe type III of hip dysplasia with broken Shenton's line more than 20 mm, an angular shape of the femoral head, a CE angle bellow -15 degrees, a high CCD angle (near to 180 degrees) and incorrect procedure technique. CONCLUSION: The study approved a favourable effect of Chiari pelvic osteotomy in patients with residual developmental hip dysplasia. The authors evaluated 130 patients operated on in the years 1969-1985 with a mean follow-up 22.3 years. In the first group (80 patients) a favourable result lasted an average of 17.6 years (3-30). 37 patients are still painfree, 35 patients have conservative treatment for osteoarthritis, 8 patients are planning a conversion to total hip replacement. Radiological signs have improved substantialy. Harris hip score has improved from 42 points to 67.5 points on average. In the second group (50 patients) a favourable result lasted for average 11.1 years (0-29). All of them had a conversion to total hip replacement at the average of 12.2 years. Chiari osteotomy gives the patients with residual developmental hip dysplasia and a correct indication favourable long-term results. It diminishes pain, prevents further subluxation and reduces the development of secondary osteoarthritis of the hip joint. (Tab. 6, Ref. 23.).

Adolescent↗
PubMed2003

Three-dimensional shape of the dysplastic femur: implications for THR.

This study evaluates the three-dimensional anatomy of the femur with congenital dysplasia of the hip (CDH) in comparison with healthy controls. Computed tomographic scans were obtained from 207 women (154 with dysplasia; 54 healthy controls) with an average age of 51.6 years (range, 18-82 years). Most of the dysplastic joints were classified as Crowe I (43%), or Crowe II or III (48%), with 9% Crowe IV. Individualized three-dimensional computer models of the femur were generated by reconstruction of the CT scans. Dimensional and morphometric parameters were derived by computer analysis of each of the femoral reconstructions. The dysplastic femurs had shorter necks and smaller, straighter canals than the controls. The shape of the canal became more abnormal with increasing subluxation. Detailed analysis showed that the primary deformity of the dysplastic femur is rotational, with an increase in anteversion of 5 degrees to 16 degrees, depending on the degree of subluxation of the hip. The rotational deformity of the dysplastic femur arises within the diaphysis between the lesser trochanter and the isthmus and is not attributable to a torsional deformity of the metaphysis. This study shows that there is a significant difference in the geometry of the normal femurs and those with CDH, even in mild cases. In CDH cases, we recommend the use of modular or specially-designed components to accommodate the shape of the dysplastic canal.

Adolescent↗
PubMed1989

[Histological studies on the controlled eruption to the rabbit lower incisor].

In order to investigate the mechanism of eruption, the rabbit lower incisors under the influence of controlled eruption were examined. The first experiment was carried out by repeated resection of the incisal edges of both upper and lower incisors so that the rate of eruption was accelerated. The second experiment was to crown the incisors for the purpose of inhibiting the eruption. In the control group, the periodontal ligament was made up of three layers. Fibers of the inner layer were continuous to the Sharpey's fibers of the cementum, and those of the outer layer were to the alveolar bone. Fibers of the middle layer ran parallel to the tooth axis. In the repeated resection group, the distance between the root end and the bottom of socket was increased, indicating the extrusion of the tooth took place. The odontogenic tissue showed increased frequency of mitosis, and the formative end of the enamel as well as the cementum shifted cervically. The eruption rate measured by the movement of metal bead embedded in the dentin, demonstrated that the rate was increased about 2 times in the repeated resection group, while the rate of growth measured by the Tetracycline method remained 1.6 times of the control group. This discrepancy was supposed to be due to the extrusion of the tooth. In case of the crowing group, the opposite was observed; the rate of eruption was reduced to about a third. Whereas the rate of growth to about a half, probably due to the intrusion of the tooth. In the crowing group, the distance between the root end and the bottom of socket was reduced, resulting the resorption of the bone tissue, and the root became sinuous, particularly at the labial side. In the lingual side, mitotic figures of the odontogenic tissue were rarely observed. The middle layer of the periodontal ligament increased in breadth in the repeated resection group, while it reduced in breadth in the crowing group. Indicating the middle layer plays an important part to the mechanism of eruption.

Animals↗
PubMedDate not supplied

[Comparative study of the neuronal structure of the neostriatum in birds with different extrapolation capabilities].

A comparative study of the neuronal structure of neostriatum in crows possessing a great capacity for extrapolation of the movement direction of an alimentary stimulus, and in pigeons deprived of it, did not reveal any fundamental differences in the size of cells, the number of dendritic endings and dendritic ramifications. Differences were observed in the neuronal morphology. In the crow neostriatum neurones, the dendrites are thinner, more sinous and provided with a denser cover of extremely fine protoplasmatic protrusions. In corresponding pigeon neurones the dendrites are thicker, more straight and with a smaller number of rather large protoplasmatic outgrowths. Such differences apparently set up morphological prerequisites for a finer analysis and processing of information, which may contribute to greater capacity of crows for extrapolation.

Animals↗
PubMed1981

[The occurrence of campylobacter fetus subsp. jejuni and Salmonella bacteria in some wild birds (author's transl)].

An investigation was carried out into the occurrence of Campylobacter fetus subsp. jejuni and Salmonella species in some wild birds. A total of 129 birds was examined, consisting of 71 pigeons, 54 seagulls, three crows and one raven. Campylobacter bacteria were isolated from 32 birds (24.8%), of which three were pigeons, 27 seagulls and two were crows. Of the 27 Campylobacter strains isolated from seagulls, four had the biochemical characteristics of the NARTC biotype described by Skirrow and Benjamin, seven were grouped as Campylobacter coli biotype and 16 as the biotype of Campylobacter jejuni. All the strains isolated from crows and pigeons had the biochemical characteristics of Campylobacter jejuni biotypes. Salmonella bacteria were isolated from the intestinal contents of two of the 54 seagulls (3.7%), and were identified serologically as Salmonella indiana and Salmonella typhimurium. One seagull was found to be a carrier of both Campylobacter fetus subsp. jejuni and Salmonella typhimurium. A correlation could not be demonstrated between the occurrence of Salmonella bacteria and Campylobacter fetus subsp. jejuni.

Animals↗
PubMed1993

[Differential fertility in the Kharkhov population].

The distribution of the number of pregnancies, births and abortions in the Kharkov population was analysed in the cohort of women with the completed fertility. The mean number of pregnancies per woman was 3.77 for the first generation and 4.30 for the second generation. The mean number of births in the first and second generations was 1.47 and 1.35. The Crow's Index of the opportunity for selection and its components connected with differential mortality was estimated. The value of the Crow's Index was decreased during one generation from 0.56 to 0.35. In the women of the second generations having high and secondary education, the number of pregnancies was 3.72 and 4.38, respectively, the Crow's Indexes being 0.33 and 0.35.

Adult↗
PubMedDate not supplied

[The capacity for transitive inference in birds: the solving of the Gillan test by Corvidae and pigeons].

Transitive inference in birds was investigated using D. J. Gillan (1981) experimental procedure. In the initial experiment 11 pigeons and 14 crows were trained to differentiate colour stimuli in pairs of adjacent ones from five-stimulus succession A, B, C, D, and E. The birds learned that stimulus E was associated with more food items than D, D, in turn, signalled less food items than C, and so on. Then the birds were tested by newly formed pairs of stimuli from the same succession (BD, CE, and BE). There were two series of testing. Both crows and pigeons solved the transitive inference test successfully (choosing D and E) in the series with small numbers of food items. In the series with larger numbers of food items the pigeons shifted to random performance while in crows the percentage of correct choices decreased. The proportion of adequate test solutions grew with the absolute difference between the numbers of food items associated with stimuli to compare. The capacity for solving the test in our experiments can be considered as the result of immediate comparison of the absolute numbers of food items associated with each stimulus. Thus, the data cannot be regarded as the final proof that these species are capable for transitive inference.

Animals↗
PubMed2000

Comparison of the solution conformation and dynamics of antifreeze glycoproteins from Antarctic fish.

The (1)H- and (13)C-NMR spectra of antifreeze glycoprotein fractions 1-5 from Antarctic cod have been assigned, and the dynamics have been measured using (13)C relaxation at two temperatures. The chemical shifts and absence of non-sequential (1)H-(1)H NOEs are inconsistent with a folded, compact structure. (13)C relaxation measurements show that the protein has no significant long-range order, and that the local correlation times are adequately described by a random coil model. Hydroxyl protons of the sugar residues were observed at low temperature, and the presence of exchange-mediated ROEs to the sugar indicate extensive hydration. The conformational properties of AFGP1-5 are compared with those of the previously examined 14-mer analog AFGP8, which contains proline residues in place of some alanine residues (Lane, A. N., L. M. Hays, R. E. Feeney, L. M. Crowe, and J. H. Crowe. 1998. Protein Sci. 7:1555-1563). The infrared (IR) spectra of AFGP8 and AFGP1-5 in the amide I region are quite different. The presence of a wide distribution of backbone torsion angles in AFGP1-5 leads to a rich spectrum of frequencies in the IR spectrum, as interconversion among conformational states is slow on the IR frequency time scale. However, these transitions are fast on the NMR chemical shift time scales. The restricted motions for AFGP8 may imply a narrower distribution of possible o, psi angles, as is observed in the IR spectrum. This has significance for attempts to quantify secondary structures of proteins by IR in the presence of extensive loops.

Animals↗