No abstract

No abstract

Forty-three patients (47 heels) underwent decompression of the nerve to abductor digiti minimi with partial plantar fascia release for intractable plantar fasciitis over a 4-year period. Forty-one patients (45 heels) were available for follow-up. All of the patients had failed to respond to nonoperative treatment. The mean duration of symptoms before surgery was 34.8 months (range, 12-132 months), and the mean follow-up was 31.4 months (range, 11-66 months). Seventy percent of the patients in the study were overweight or obese. Before surgery, 39 patients (43 heels) rated their heel pain as severe. At follow-up, 34 of 45 (75.6%) of the heels were pain-free or only mildly painful. The mean visual analogue pain score dropped from 8.5 of 10 preoperatively to 2.5 of 10 postoperatively. Only four patients failed to report an improvement in their activity restrictions, and only one patient had a walking distance of under 100 m after surgery; this patient had been affected by a reflex sympathetic dystrophy. Overall, however, only 20 of 41 patients were totally satisfied with the outcome (48.8%). We recommend that the small group of patients who fail to respond to nonoperative treatment be considered for surgical intervention. The results in terms of symptomatic relief are generally good but in terms of patient satisfaction can only be rated as moderate. The patients should be counseled about the likely outcome of surgery.

Snails are highly unusual among multicellular animals in that they move on a layer of costly mucus, leaving behind a trail that can be followed and utilized for various purposes by themselves or by other animals. Here we review more than 40 years of experimental and theoretical research to try to understand the ecological and evolutionary rationales for trail-following in gastropods. Data from over 30 genera are currently available, representing a broad taxonomic range living in both aquatic and terrestrial environments. The emerging picture is that the production of mucus trails, which initially was an adaptation to facilitate locomotion and/or habitat extension, has evolved to facilitate a multitude of additional functions. Trail-following supports homing behaviours, and provides simple mechanisms for self-organisation in groups of snails, promoting aggregation and thus relieving desiccation and predation pressures. In gastropods that copulate, trail-following is an important component in mate-searching, either as an alternative, or in addition to the release of water- or air-borne pheromones. In some species, this includes a capacity of males not only to identify trails of conspecifics but also to discriminate between trails laid by females and males. Notably, trail discrimination seems important as a pre-zygotic barrier to mating in some snail species. As production of a mucus trail is the most costly component of snail locomotion, it is also tempting to speculate that evolution has given rise to various ways to compensate for energy losses. Some snails, for example, increase energy intake by eating particles attached to the mucus of trails that they follow, whereas others save energy through reducing the production of their own mucus by moving over previously laid mucus trails. Trail-following to locate a prey item or a mate is also a way to save energy. While the rationale for trail-following in many cases appears clear, the basic mechanisms of trail discrimination, including the mechanisms by which many snails determine the polarity of the trail, are yet to be experimentally determined. Given the multiple functions of trail-following we propose that future studies should adopt an integrated approach, taking into account the possibility of the simultaneous occurrence of many selectively advantageous roles of trail-following behaviour in gastropods. We also believe that future opportunities to link phenotypic and genotypic traits will make possible a new generation of research projects in which gastropod trail-following, its multitude of functions and evolutionary trade-offs can be further elucidated.

Sexual size dimorphism is widespread among dioecious species but its underlying driving forces are often complex. A review of sexual size dimorphism in marine gastropods revealed two common patterns: firstly, sexual size dimorphism, with females being larger than males, and secondly females being larger than males in mating pairs; both of which suggest sexual selection as being causally related with sexual size dimorphism. To test this hypothesis, we initially investigated mechanisms driving sexual selection on size in three congeneric marine gastropods with different degrees of sexual size dimorphism, and, secondly, the correlation between male/female sexual selection and sexual size dimorphism across several marine gastropod species. Male mate choice via mucus trail following (as evidence of sexual selection) was found during the mating process in all three congeneric species, despite the fact that not all species showed sexual size dimorphism. There was also a significant and strong negative correlation between female sexual selection and sexual size dimorphism across 16 cases from seven marine gastropod species. These results suggest that sexual selection does not drive sexual size dimorphism. There 2 was, however, evidence of males utilizing a similar mechanism to choose mates (i.e. selecting a female slightly larger than own size) which may be widespread among gastropods, and in tandem with present variability in sexual size dimorphism among species, provide a plausible explanation of the observed mating patterns in marine gastropods.

This is the first series specifically assessing patients who have had repeat arthroscopic debridement of osteochondral lesions of the talus, using the same debridement technique by a single surgeon. Our results question the assumption that repeat arthroscopic debridement yields poor results. They also provide a baseline for the newer chondral and osteochondral transplantation techniques to compare to at the medium term.

Hong Kong is within the tropics and has a seasonal climate. In winter, shores support patches of ephemeral macroalgae and areas of seemingly bare rock close to crevices where molluscan herbivores are abundant. Using a factorial design of herbivore exclusions in areas far and close to crevices, the development of algal assemblages was monitored in mid-shore, cleared areas, in winter. To estimate the role of herbivore mucus deposition, half the treatments received a mucus application. Algal development was estimated from macroalgal and biofilm development and chlorophyll a levels. In all areas, biofilms (diatoms, unicellular cyanobacteria) developed rapidly in herbivore exclusions followed by ephemeral macroalgae (Enteromorpha spp. and Porphyra suborbiculata). In herbivore access treatments, however, the algal assemblage was influenced by treatment location; few macroalgae developed in areas close to crevices, and the rock was dominated by cyanobacteria. A negative relationship between macroalgae and biofilms suggested that ephemeral algae were competitively dominant. In areas distant from herbivore refuges, ephemeral macroalgae did develop, illustrating that the effectiveness of molluscan herbivores was limited to 50 to 100 cm from these refuges. The absence of large herbivorous fish, and the sparse numbers of herbivorous crabs at this site, means that algae can achieve a spatial escape from consumption, and where this occurs competition between producers is important in assemblage development. Mucus appeared to play a limited role, only sometimes stimulating initial stages of unicellular cyanobacteria and macroalgae. With the onset of summer, macroalgae died back, and rock space became available for colonization. Unicellular cyanobacteria developed rapidly but were replaced in all treatments by the encrusting macroalga, Hapalospongidion gelatinosum, which dominated treatments until the end of the experiment. On seasonal, tropical shores processes influencing community structure can, therefore, be temporally variable and their relative importance, even at the same shore level, can change with season.

22A key element missing from many predictive models of the impacts of climate change 23 on intertidal ectotherms is the role of individual behaviour. In this synthesis, using 24 littorinid snails as a case study, we show how thermoregulatory behaviours may 25 buffer changes in environmental temperatures. These behaviours include either a 26 flight response, to escape the most extreme conditions and utilize warmer or cooler 27 environments; or a fight response, where individuals modify their own environments 28 to minimize thermal extremes. A conceptual model, generated from studies of 29 littorinid snails, shows that various flight and fight thermoregulatory behaviours may 30 allow an individual to widen its thermal safety margin (TSM) under warming or 31 cooling environmental conditions and hence increase species' resilience to climate 32 change. Thermoregulatory behaviours may also buffer sublethal fitness impacts 33 associated with thermal stresses. Through this synthesis, we emphasise that future 34 studies need to consider not only animals' physiological limits but also their capacities 35 to buffer the impact of climate change through behavioural responses. Current 36 generalizations, made largely on physiological limits of species, often neglect the 37 buffering effects of behaviour and may, therefore, provide an over-estimation of 38 vulnerability, and consequently poor prediction of the potential impacts of climate 39 change on intertidal ectotherms. 40 41