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22


Top-down vs. bottom-up effects in kelp forests [Letter]

Steele, Mark A; Schroeter, Stephen C; Carpenter, Robert C; Kushner, David J
PMID: 16998963
ISSN: 1095-9203
CID: 94859

Assessing the magnitude of intra- and interspecific competition in two coral reef fishes

Forrester, Graham E; Evans, Bryn; Steele, Mark A; Vance, Richard R
Many field experiments have tested for effects of competition in nature, but relatively few have used designs allowing simultaneous assessment of the influence of intra- and interspecific competition. Using a response surface design and a press manipulation of densities, we tested effects of competition within and between two species of coral reef fishes (Coryphopterus glaucofraneum and Gnatholepis thompsoni). By tracking individually tagged fishes, we showed that the per-capita effect of intraspecific competitors on individual growth was at least twice as great as the effect of interspecific competitors. Growth rate was better predicted by measures of density that incorporated body size, rather than numerical density, suggesting interference competition. Individuals of both species interacted aggressively with conspecifics at least twice as often as with heterospecifics. Individuals of both species also covered more area while foraging and spent less time in shelter when crowded than when at lower densities. In combination, these behaviours suggest that increased metabolic costs at high density contribute to competitive effects on growth. These competitive interactions occurred among adult fishes, so reduced growth may translate to reduced fecundity as well as reduced survival, and so contribute to population regulation
PMID: 16518631
ISSN: 0029-8549
CID: 94860

Risk factors for amblyopia in children with capillary hemangiomas of the eyelids and orbit

Schwartz, Shirah R; Blei, Francine; Ceisler, Emily; Steele, Mark; Furlan, Louis; Kodsi, Sylvia
Introduction: Capillary hemangiomas are the most common orbital tumors of childhood and can cause amblyopia secondary to occlusion of the pupil, anisometropia, or strabismus. We undertook this study to describe the clinical characteristics of children with capillary hemangiomas and to propose a classification system to guide clinical treatment decisions. Methods: A retrospective review of the records of 129 patients with 132 capillary hemangiomas in two pediatric ophthalmology practices was conducted. Hemangiomas were classified based on size. Presence of aniosometropic astigmatism, ptosis, pupillary occlusion, lid margin change, proptosis, globe displacement, and strabismus was recorded. Results: Thirty-one hemangiomas measured less than 1 cm in greatest dimension and were not associated with amblyogenic factors. Seventy-five patients had hemangiomas that measured greater than 1 cm, 40 of which were associated with amblyopia. Eighteen children had diffuse hemangiomas that could not be measured and 14 of these were associated with amblyopia. Five of seven hemangiomas in six patients with PHACES syndrome were associated with amblyopia. Conclusion: This study is the largest review of capillary hemangiomas of the orbit and eyelids. Our findings suggest that size greater than 1 cm in largest diameter is an important predictor of amblyogenic factors and approximately half of these patients will require treatment. Diffuse hemangiomas and hemangiomas in patients with PHACES syndrome will cause amblyopia in the majority of cases
PMID: 16814181
ISSN: 1091-8531
CID: 66077

Small-scale field experiments accurately scale up to predict density dependence in reef fish populations at large scales

Steele, Mark A; Forrester, Graham E
Field experiments provide rigorous tests of ecological hypotheses but are usually limited to small spatial scales. It is thus unclear whether these findings extrapolate to larger scales relevant to conservation and management. We show that the results of experiments detecting density-dependent mortality of reef fish on small habitat patches scale up to have similar effects on much larger entire reefs that are the size of small marine reserves and approach the scale at which some reef fisheries operate. We suggest that accurate scaling is due to the type of species interaction causing local density dependence and the fact that localized events can be aggregated to describe larger-scale interactions with minimal distortion. Careful extrapolation from small-scale experiments identifying species interactions and their effects should improve our ability to predict the outcomes of alternative management strategies for coral reef fishes and their habitats
PMCID:1224630
PMID: 16150721
ISSN: 0027-8424
CID: 94861

Double-outlet right ventricle with partial anomalous pulmonary venous connection: prenatal diagnosis [Case Report]

Patel, Chandrakant R; Steele, Mark A; Stewart, John W
PMID: 15914691
ISSN: 0278-4297
CID: 94862

Growth of estuarine fish is associated with the combined concentration of sediment contaminants and shows no adaptation or acclimation to past conditions

Forrester, Graham E; Fredericks, Brett I; Gerdeman, Dean; Evans, Bryn; Steele, Mark A; Zayed, Kareem; Schweitzer, Linda E; Suffet, Irwin H; Vance, Richard R; Ambrose, Richard F
We tested whether the growth rates of small benthic fish (Gillichthys mirabilis) in three southern California estuaries corresponded with the local concentrations of contaminants. Fish originating from each estuary were transplanted to cages in each estuary in two reciprocal transplant experiments. The growth rates of caged fish, and the size-distribution of natural populations, showed the same pattern of difference among estuaries. Twelve metals and organic contaminants occurred in bulk sediments at concentrations close to their individual ERL values, and a simple index of their combined concentration (the mean ERL quotient) was inversely correlated to the growth of caged fish. Metals in the water column occurred at lower concentrations, relative to toxicity thresholds, than those in sediments and were unrelated to fish growth. Fish used in the field caging experiments, and other fish held in the laboratory under constant conditions, showed no difference in growth according to their estuary of origin. Fish originating from different estuaries also showed no consistent differences in their tissue burden of organic contaminants. Our results thus suggested no genetic adaptation or physiological acclimation to the past contaminant regime, but revealed a possible association between fish growth rates and the combined concentration of multiple sediment contaminants
PMID: 12738223
ISSN: 0141-1136
CID: 94863

Congenital self-healing reticulohistiocytosis with eye involvement [Case Report]

Zaenglein AL; Steele MA; Kamino H; Chang MW
Congenital self-healing reticulohistiocytosis (CSHR) represents the benign end of the spectrum of Langerhans cell histiocytoses, with spontaneous resolution of lesions within the first year of life. However, involvement of organ systems other than the skin has been described occasionally and recurrence of disease at sites distant from the skin has been documented. We report a case of CSHR with eye involvement that spontaneously resolved concurrent with resolution of skin lesions. Because multiple organ systems can be involved and recurrences are possible, long-term follow-up of these patients is indicated
PMID: 11358555
ISSN: 0736-8046
CID: 20659

A prospective study of the relationship between strabismus and head posture in patients with frontal plagiocephaly

Gosain AK; Steele MA; McCarthy JG; Thorne CH
A prospective study was performed on 16 unoperated patients with frontal plagiocephaly to characterize the relationship between strabismus and abnormal head posture. Serial eye examinations were performed preoperatively and for 24 to 46 months following fronto-orbital advancement. In 14 patients (88 percent), preoperative clinical examination and CT scan indicated coronal plagiocephaly (synostotic); unicoronal synostosis was documented during fronto-orbital advancement in all these patients. Ten patients had abnormal head posture on preoperative examination, 9 of whom had strabismus at some time during the study. These 9 patients all had unicoronal synostosis with ipsilateral strabismus and a contralateral head tilt. All had eye muscle findings consistent with superior oblique paresis, although in 2 patients these signs first developed following fronto-orbital advancement. Strabismus resolved spontaneously in 2 patients between 2 and 8 months following fronto-orbital advancement; the remaining 7 patients underwent extraocular muscle surgery following fronto-orbital advancement, with early resolution of strabismus in all cases. The head tilt resolved or improved significantly in all 9 patients following resolution of the strabismus. Two patients had recurrent superior oblique paresis following surgical correction, necessitating secondary strabismus surgery. The present study indicates that extraocular muscle dysfunction is the major cause of abnormal head posture in patients with coronal plagiocephaly and emphasizes the need for long-term ophthalmologic surveillance in these patients
PMID: 8618990
ISSN: 0032-1052
CID: 7000

Congenital esotropia

Steele M; Furlan L; Howard N
ORIGINAL:0004461
ISSN: 0896-1549
CID: 34102

Sub-Tenon's infusion of local anesthetic for strabismus surgery [see comments] [Comment]

Steele MA; Lavrich JB; Nelson LB; Koller HP
We used a blunt irrigating cannula to infuse tetracaine 0.5% solution into the posterior sub-Tenon's space in 26 consecutive patients undergoing strabismus surgery under local anesthesia. All patients were sedated with combinations of fentanyl citrate and either propofol or midazolam. The results suggest that this technique is a safe and effective method of performing strabismus surgery under local anesthesia
PMID: 1574266
ISSN: 0022-023x
CID: 9339