A letter e ∈ Σ is said to be neutral for a language L if it can be inserted and deleted at will in a word without affecting membership in L. The Crane-Beach Conjecture, which was recently disproved, stated that any language containing a neutral letter and definable in FO is in fact FO[<] definable and is thus a regular, star-free language. More generally, we say that a logic or a computational ...

Marine beach water quality is typically monitored in early morning once a week without respect to tidal condition. To assess the effect of tide on this public health warning system, we analyzed enterococci (ENT) data from 60 southern California marine beaches with differing geomorphology, orientation, and proximity to runoff sources. ENT concentrations during spring tides were significantly hig...

The majority of the touristic activities, especially in the Mediterranean countries, are concentrated around coastal areas, making coastal erosion, among others, a significant threat to coastal economies that depend heavily on revenue from tourism. In this paper a methodology for the estimation of the economic impact of beach erosion to tourism, is been described. Input about the conceptualizat...

Monitoring microbial water quality is essential for recreational beaches in order to protect human health. To evaluate the relative importance and impacts of various types of non-point microbial sources at a subtropical beach (Hobie Beach, Miami, USA), we utilized a coastal ocean circulation model (Delft3D) with a microbe transport-fate model. Those non-point sources include beach sediment, dog...

In order to better understand the nature of disturbances to wintering snowy plovers, I observed snowy plovers and activities that might disturb them at a beach near Devereux Slough in Santa Barbara, California, USA. Disturbance (activity that caused plovers to move or fly) to wintering populations of threatened western snowy plovers was 16 times higher at a public beach than at protected beache...

Pollution, exploitation of resources, erosion and recreational activities produce the most common impacts that somehow alter the natural balance of beach ecosystems. The aim of this study was to compare the richness and abundance of the benthic macrofauna of two sectors, one non-urbanized and the other urbanized, on each of two morphodynamically different beaches. Sectors of each beach were ana...

Incidences of Staphylococcus aureus and methicillin resistant S. aureus (MRSA) have risen worldwide prompting a need to better understand routes of human exposure and whether standard bacterial water quality monitoring practices adequately account for this potential threat. Beach water and sand samples were analyzed during summer months for S. aureus, enterococci, and MRSA at three southern Cal...

Cross-shore exchange of plankton plays an important role in marine ecosystems and coastal communities. Larvae of many intertidal invertebrate species grow offshore and come back to the shore for settlement by crossing the energetic surf zone; however, shoreward transport mechanisms are not well understood. To test the possible onshore transport mechanisms, numerical simulations were performed b...

BACKGROUND Very little is known about the injury characteristics of beach volleyball. PURPOSE To describe the incidence and pattern of injuries among professional male and female beach volleyball players. STUDY DESIGN Cohort study--retrospective injury recall and prospective registration. METHODS Injuries occurring over a 7.5-week interval of the summer season were retrospectively registe...

The seashore, especially coral bank, is sensitive to human activities and environmental changes. A multispectral image, with coarse spectral resolution, is inadaptable for identify subtle spectral distinctions between various beaches. To the contrary, hyperspectral image with narrow and consecutive channels increases our capability to retrieve minor spectral features which is suit for identific...