Variation and variability.

The world has been turned upside down with the novel Coronavirus pandemic. The most effective approaches to prevent the spread of the virus have been social distancing and wearing personal protective equipment (PPE), which has significantly changed our approach to life. Most of our daily activities have been altered, including medical appointments. My physicians have recommended that I cancel or postpone medical appointments that are not critical. To the extent that I am able, I have followed their advice.

The reniform reflecting superposition compound eyes of Nephrops norvegicus: optics, susceptibility to light-induced damage, electrophysiology and a ray tracing model.

The large reniform eyes of the reptant, tube-dwelling decapod Nephrops norvegicus are described in detail. Optically these reflecting superposition compound eyes are a little unusual in that they are laterally flattened, a feature that may enhance their sensitivity in that region, albeit at the expense of resolution. Electrophysiological and anatomical investigations suggest that the eyes are tuned to appropriate spectral and temporal sensitivities in the long and short term through movement of proximal pigments and possibly rhabdom adaptation. Although exposure to ambient surface light intensities is shown to cause damage to the retinal layer, especially in deeper living animals, there is no evidence yet that demonstrates an impact of eye damage on their survival. It is suggested that experimentation on marine decapods, with sensitive eyes, requires that particular attention is paid to their light environment.

Development of merosporangia in Linderina pennispora (Kickxellales, Kickxellaceae).

The vegetative and sporulating structures of Linderina pennispora are described using scanning and transmission electron microscopy. The vegetative hyphae and sporangiophores were regularly septate, possessed a two-layered wall, and coated with rod-shaped, 0.2-0.7 µm long, 0.15-0.25 µm wide ornamentations. The sporangiophore was erect, cylindrical, and narrower (4-8 µm) than the vegetative mycelium (8-12 µm). The mature sporocladium was ovoid to dome-shaped, sessile, non-septate, 18-24 µm diam, possessed a two-layered wall, and coated with rod-shaped ornamentations. Mature pseudophialides were ellipsoid, 2.0-2.5 µm wide, 4-7 µm long, possessed a two-layered wall, and formed in a series of concentric groups radiating from the "apex" of the sporocladium. The pseudophialides had a round, ca. 1.5 µm diam, base with a narrower, 0.7-0.8 µm diam lobed, cylindrical neck structure in the distal region which extended to the pseudophialide neck. The merosporangia were obovate, 3-4 µm wide near the base, and narrowed distally to 2.0-2.5 µm wide, 18-23 µm long, possessed a three-layered wall, with regular surface annulation with interconnecting ridges, but lacked rod-shaped ornamentations. The merosporangia contained a single, obovate, 2.3-2.5 µm diam merosporangiospore, with a ca. 1 µm diam papilla-like base, that possessed a four-layered wall. Detached merosporangia had a single, acicular, unbranched, 3-5 µm long, ca. 0.1 µm diam "appendage" that was attached to the merosporangiospore inner cell wall layer and passed through the septum plug to the pseudophialide.

A longitudinal study of the survival of All-on-4 implants in the mandible with up to 10 years of follow-up.

BACKGROUND: Immediate-function implants have become an accepted alternative for fixed restoration protocols in edentulous mandibles on the basis of documented high success rates. The All-on-4 concept (Nobel Biocare, Göteborg, Sweden), a surgical and prosthetic protocol for immediate function involving the use of four implants to support a fixed prosthesis in patients with completely edentulous mandibles, represents one of these protocols. The authors conducted a study to document long-term follow-up of the All-on-4 concept. METHODS: This longitudinal study included 245 patients with a total of 980 immediate-function implants (four per patient), all placed in the anterior region, to support fixed full-arch mandibular prostheses. The inclusion criterion was having an edentulous mandible, or a mandible with hopeless teeth, in need of fixed implant restorations. RESULTS: A total of 21 implants failed in 13 patients, giving cumulative patient-related and implant-related success rates of 94.8 percent and 98.1 percent, respectively, at five years, and 93.8 percent and 94.8 percent, respectively, with up to 10 years of follow-up. The prostheses' survival rate was 99.2 percent with up to 10 years of follow up. CONCLUSIONS: The results support the conclusion that use of the All-on-4 immediate-function implant concept in completely edentulous mandibles is viable in the long term. CLINICAL IMPLICATIONS: High prosthesis survival rates can be achieved by the use of four implants to support a full-arch fixed prosthesis in the mandible.

Targeting of calcium:calmodulin signals to the cytoskeleton by IQGAP1.

Mast cells reorganize their actin cytoskeleton in response to cytosolic calcium signals while in parallel secreting histamine and other inflammatory mediators. The effect of calcium on actin is mediated in large part through calmodulin. EGFP-tagged calmodulin is concentrated in the actin-rich cortex of RBL-2H3 mast cells. Transfection with small interfering RNA directed against the actin and calmodulin-binding protein IQGAP1 dramatically reduced expression of the latter protein and reduced or eliminated the concentration of calmodulin at the actin-rich cortex. Both actin reorganization and secretion were enhanced in IQGAP1 knockdown cells. Our results suggest a model in which calmodulin is targeted to and sequestered at the actin cytoskeleton by IQGAP1. Upon cell stimulation and the subsequent [Ca2+]i increase, it is immediately available to activate local downstream targets.

Early-onset schizophrenia in children with mental retardation: diagnostic reliability and stability of clinical features.

OBJECTIVES: To investigate the presentation of early-onset schizophrenia in children with mental retardation (MR) and the stability of clinical features over time. METHOD: A purpose-designed assessment protocol was developed based on best-practice recommendations in the research literature. Diagnostic reliability, investigated in a group of 20 children with MR, was found to be very good (kappa = 0.87). Using this protocol, the clinical service identified 10 children with an initial diagnosis of schizophrenia. This group was then reassessed 2 years later. RESULTS: At the end of 2 years, 8 of the 10 children with schizophrenia still warranted this diagnosis. However, there was considerable instability in relation to certain diagnostic criteria, notably delusions and visual hallucinations. In all cases some improvements in severity were seen at follow-up. However, the eight whose schizophrenia was confirmed at follow-up showed major deterioration in cognitive level. CONCLUSIONS: It is possible to make reliable diagnoses of early-onset schizophrenia in people with MR, provided the assessment system is carefully structured and pays attention to all the important sources of information. However, symptoms should be reviewed frequently, particularly those that cannot be substantiated by patient interview.

Guidelines for assessing the biofidelity of side impact dummies of various sizes and ages.

The Human Mechanical Simulation Subcommittee of the Human Biomechanics and Simulation Standards Committee of the Society of Automotive Engineers took on the task of defining test procedures and associated response guidelines to be used to assess the level of biofidelity of side impact dummies that are being developed. This paper describes the results of their efforts. Guidelines are provided for assessing the levels of biofidelity of dummies that represent 6-, 12-, and 18-month-old infants, 3-, 6-, and 10-year-old children, and of dummies that represent a small female, midsize male and large male adults. These guidelines were developed by normalizing the side impact biofidelity guidelines that were established by the International Standards Organization for the head, neck, shoulder, thorax, abdomen and pelvis of the midsize adult male. The ISO guidelines can be used to define biofidelity guidelines for any size or age of dummy provided pertinent geometric, inertial and tissue properties are specified.