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Hannaea baicalensis is a benthic pennate diatom that predominantly grows at depths of less than a metre attached to rocks and filamentous algae in Lake Baikal, Russia. This narrow zone at the edge of the lake is subject to frequent wave action and lake level fluctuations, which combine with other factors to affect seasonal abundance. During ice cover from January to May in 2008, when lake levels decreased from 42 to 14 cm above datum, H. baicalensis cell abundance remained low (0.39 × 106 cells cm–2). The main period of net cell increase occurred in autumn, when there was a period of stable lake level (±10 cm changes in water depth) that coincided with the return of nutrients during autumn overturn. Cell abundance reached 1.52 × 106 cells cm–2 on 31 October. Alongside the changes in abundance, cyclic size changes in cell apical lengths were found (40 to 144 µm), which were associated with timing of the length of the life cycle. Size decline occurred in both spring and autumn, with an average decre...

The purpose of this study is to evaluate the efficacy of simple aspiration of cystic thyroid nodules by comparing with control groups to exclude the occurrence of spontaneous regression by the definition of current guidelines of American Thyroid Association.217 nodules from 210 patients with cystic thyroid nodules (cystic portion50%) were included. Nodules were classified into three groups as follows: Group 1, observation only; Group 2, fine needle aspiration (FNA) without aspiration of internal fluid; and Group 3, FNA after aspiration of internal fluid. Significant nodule size change was defined as a difference in the largest diameter of 20%, as seen on the last follow-up ultrasound (US) compared to the initial US.Demographic characteristics did not show significant differences among the three groups except for the patient age (p = 0.039). Mean nodule size significantly decreased only in group 3 (p = 0.005). Significant nodule size reductions were observed in 22.0% (13/59) in group 1, 25.7% (28/109) in group 2, and 40.8% (20/49) in group 3, respectively.Aspiration of internal fluid should be considered as the first-line procedure for both the diagnosis and treatment of cystic or predominantly cystic thyroid nodules.

A dense late Neogene history of pocket gophers from the Meade Basin of south-western Kansas and north-western Oklahoma preserves a detailed record of size change, as indicated by mean length of the lower fourth premolar. A ‘time for space substitution’ interpretation results in the tentative recognition of a pattern analogous to character displacement, in which the small to medium-sized Pliogeomys buisi, P. louderbachi, Geomys minor and G. floralindae are considered ecological analogues and treated as a single ecological entity, Avatar A. The larger G. jacobi and G. quinni are combined as Avatar B. Statistical analyses confirm that populations of Avatar A are of equal size when allochronic from Avatar B, and significantly smaller when synchronic (and sympatric) with Avatar B. However, this pattern is complicated by the observation that Avatar A began dwarfing before the appearance of Avatar B. This historical perspective suggests that static size patterns among modern taxa may have a complex history. Occa...

For decades, electroactive polymers received relatively little attention due to their limited actuation capability. However, in the last 15 years, a series of electroactive polymer materials have emerged that produce a significant shape or size change in response to electrical stimulation. These materials have the closest functional similarity to biologic muscles, enabling the engineering of novel capabilities that were, up until recently, impossible to achieve. Efforts are underway to address the many challenges that are hampering the practical application of these materials, and recent progress has already led to dramatic capability improvements. Various novel mechanisms and devices were demonstrated including robotic fish, catheter steering elements, robotic arms, miniature grippers, loudspeakers, active diaphragms, Braille display and dust-wipers. For developers of future medical devices, these materials are offering numerous advantages for their flexibility, fracture toughness and controllability, as well as low mass and low power requirements. This article provides a review of the current status, challenges and potential near-future applications of these materials.

SUMMARYNine queen honey bees (Apis mellifera) were restricted for 4 h 30 min under a queen-excluder cap on an empty comb in the centre of the broodnest. 25 eggs were removed from each comb and their length and width were measured, as well as the length of the embryo. The egg removal and measurements were repeated every 7 h 30 min. In total, 2475 eggs were measured, on which 7425 measurements were made. In addition, groups of 25 eggs were weighed in four determined periods. Results showed that the length, width and volume of eggs 7 h 30 min-12 h old reduced to 98%, 98% and 94% of their initial dimensions, respectively Eggs 15–19 h 30 min old increased the three dimensions to 99%, 98% and 96%, respectively Next the eggs decreased to 91 %, 90% and 73% at the age of 52 h 30 min-57 h. Subsequently a peculiar phenomenon occurred, namely the eggs increased to 93%, 92% and 78% at the time of hatching. The embryo changed its length similarly to the egg. The correlation coefficient between the length of embryo and ...

Standardised data, representing ‘adulthood’, reveal that in characters of gross shape, shell thickness and size G. (Gryphaea) exhibits marked changes through the European Lower Jurassic. Evolution, evidently anagenetic, was not certainly unidirectional and even‐paced (truly gradualistic) in any character — for some characters brief periods of stasis may have occurred. However, few, if any, intervals were marked by stasis in all characters, and no horizons by especially conspicuous change. Punctuated equilibrium is thus not displayed. Parallel patterns of gross shape, thickness and size change can be readily integrated in an ‘adaptational’ model of evolution upon appreciation that each variable is likely to affect shell stability, a factor influencing survival in reclining bivalves. Thus periods of evolution towards a more stable gross shape (broader, flatter) are considered to be a selectively‐driven response to coeval size and thickness changes (reductions) tending to diminish stability in a shell poorly...

The nuclear volume in cells of the subfornical organ of Rana esculenta shows a cyclic annual size change. It is pronounced both in the so‐called Gomori‐positive cells and the ependymal covering of the organ. There appears a maximum in April in the epen‐dyma and in May in the Gomori‐positive cells. The amount of neurosecretory material present in the subependymal layer also shows a maximum in April.

Burnishing is a plastic deformation process in which force is applied on to a metal surface through a hard roller or ball. In this paper, an attempt has been made to investigate the optimum burnishing force, change in dimension and the variations of tangential and normal forces in the process. Expressions were derived to calculate analytically the following: (i) optimum burnishing force, (ii) size change in burnishing. The accuracy of these expressions was verified by suitably conducted experiments. Five non-dimensional numbers of importance to burnishing were established. The variation of normal and tangential forces in roller burnishing (and so the coefficient of friction) was investigated experimentally.