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Irregular Form (irregular + form)

Distribution by Scientific Domains

Psychology	50%

Selected Abstracts

Juvenile psoriatic arthritis with nail psoriasis in the absence of cutaneous lesions

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2000
Carola Duran-McKinster MD
A 4-year-old white boy without a significant family history had morning stiffness and painful swelling of his left knee and ankle, right elbow, and dorsolumbar region of 2 months' evolution. The following laboratory studies were within normal limits: complete blood cell count, C-reactive protein (CRP), latex, antistreptolysin, and antinuclear antibodies. Rheumatoid factor was negative and an increase in the erythrocyte sedimentation rate (ESR) was detected (56 mm/h). The pediatric department made an initial diagnosis of juvenile rheumatoid arthritis, and treatment with acetylsalicylic acid at 100 mg/kg/day and naproxen at 10 mg/kg/day was started. A thick, yellowish toenail was diagnosed as onychomycosis. No mycologic investigations were performed. Intermittent episodes of painful arthritis of different joints were present. The radiographic features of the peripheral joints included: narrow joint spaces, articular erosions, soft tissue swelling, and diffuse bony demineralization. Characteristic bilateral sacroiliitis and a swollen tendon sheath on the left ankle were detected. At 11 years of age the nail changes had extended to five other toenails and to four fingernails, were yellow,brown in color, and showed marked subungual hyperkeratosis ( Figs 1, 2). The rest of the nails showed significant nail pitting. Trials of griseofulvin alternated with itraconazole in an irregular form for five consecutive years resulted in no clinical improvement, which prompted a consultation to our dermatology department. On three different occasions, KOH nail specimens were negative for fungus, but the presence of parakeratotic cells aroused the suspicion of psoriasis. A complete physical examination was negative for psoriatic skin lesions. A nail bed biopsy specimen was characteristic of nail psoriasis ( Fig. 3). Figure 1. Thickened nails with severe subungual hyperkeratosis in five fingernails Figure 2. Secondary deformity of nail plate. No "sausage" fingers were observed Figure 3. Light microscopic appearance of a nail biopsy specimen showing parakeratotic hyperkeratosis, elongation of interpapillary processes, and Munroe abscess (arrow) (hematoxylin and eosin stain, ×40) The following human leukocyte antigens (HLAs) were positive: A9, A10, B12, B27, Cw1, Bw4, DR6, DR7, DQ1, DQ2, and DR53. A diagnosis of juvenile psoriatic arthritis associated with nail psoriasis was made. Toenail involvement became so painful that walking became very difficult. Occlusive 40% urea in vaseline applied to the affected toenails for 48 h resulted in significant improvement. Currently, the patient is 20 years old with nail involvement, but no psoriatic skin lesions have ever been observed. [source]

Maternal and fetal microvasculature in sheep placenta at several stages of gestation

JOURNAL OF ANATOMY, Issue 3 2010
Shireen A. Hafez
Abstract Maternal and fetal microvasculature was studied in ewes at days 50, 90 and 130 of gestation using microvascular corrosion casting and scanning electron microscopy. Microvascular corrosion casts of caruncles at day 50 were cup-shaped with a centrally located cavity. Branches of radial arteries entered the caruncle from its base and ramified on the maternal surface of the caruncle. Stem arteries broke into an extensive mesh of capillaries forming crypts on the fetal surface. The architecture of the caruncle at day 90 was similar to what was found at day 50 but the vascularity and the depth of the crypts increased in correspondence to increased branching of fetal villi. The substance of the caruncle was thicker at day 130 compared with day 50, with no remarkable difference compared with day 90. Capillary sinusoids of irregular form and diameter were observed on the fetal surface of the caruncle at all stages. These sinusoids may reduce blood flow resistance and subsequently increase transplacental exchange capacity. A microvascular corrosion cast of the cotyledon was cup-shaped with wide and narrow sides. Cotyledonary vessels entered and left the cotyledon from the narrow side. A cotyledonary artery gave proximal collateral branches immediately after entering the cotyledon and then further branched to supply the remaining portion of the cotyledon. Vessel branches broke into a mesh of capillaries forming the fetal vascular villi. Fetal villi that were nearest to the center of the cotyledon were the longest. Capillaries forming villi were in the form of a web-like mesh, were irregular in size and had sinusoidal dilations. The architecture of the cotyledon at day 90 was similar to day 50, but the vascularity increased. Branching of the fetal villi became more abundant. This extensive branching presumably allows a higher degree of invasion and surface contact to maternal tissues. At day 130, the distal portions of the fetal villi showed low ridges and troughs to increase the surface area for diffusion. Branching of fetal villi appears to influence the elaboration of maternal crypts in all stages of gestation. However, correspondence between crypts and villi is restricted to distal portions of fetal villi. [source]

The role of type and token frequency in using past tense morphemes correctly

DEVELOPMENTAL SCIENCE, Issue 2 2007
Elena Nicoladis
Type and token frequency have been thought to be important in the acquisition of past tense morphology, particularly in differentiating regular and irregular forms. In this study we tested the role of frequency in two ways: (1) in bilingual children, who typically use and hear either language less often than monolingual children and (2) cross-linguistically: French and English have different patterns of frequency of regular/irregular verbs. Ten French-English bilingual children, 10 French monolingual and 10 English monolingual children between 4 and 6 years watched a cartoon and re-told the story. The results demonstrated that the bilingual children were less accurate than the monolingual children. Their accuracy in both French and English regular and irregular verbs corresponded to frequency in the input language. These results are consistent with the hypothesis that children learn past tense morphemes by analogy with other words in their vocabularies. We propose a developmental sequence based on conservative generalization across a growing set of verbs. [source]

Overtensing and the effect of regularity

COGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 6 2002
Joseph Paul Stemberger
Abstract Regularly inflected forms often behave differently in language production than irregular forms. These differences are often used to argue that irregular forms are listed in the lexicon but regular forms are produced by rule. Using an experimental speech production task with adults, it is shown that overtensing errors, where a tensed verb is used in place of an infinitive, predominantly involve irregular forms, but that the differences may be due to phonological confounds, not to regularity per se. Errors involve vowel-changing irregular forms more than suffixing inflected forms, with at best a small difference between regular -ed and irregular -en. Frequency effects on overtensing errors require a model in which the past-tense and base forms of the verb are in competition and in which activation functions are nonlinear, and rule out models with specialized subnetworks for past-tense forms. Implications for theories of language production are discussed. [source]