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AbstractIn the ophioplutei of brittle stars, the posterior coeloms are commonly assumed to be produced by a transverse fission of the initially formed coeloms; but in ophioplutei of Ophiopholis aculeata, the posterior coeloms first appear separately as aggregations of mesenchyme-like cells near the base of the posterolateral arms. Initiation of posterior coeloms was similar in ophioplutei of another family and may be similar in diverse ophiuroids. Initiation is easily missed without frequent observations. Early interpretations that diagrammed a fission of the first-formed coeloms appear to have influenced later authors for more than a century. Growth of posterior coeloms from a small initial size facilitated observations of developmental plasticity in growth of coeloms relative to that of larval arms. This plasticity, as observed in echinoplutei of echinoids, is relatively greater growth of a ciliary band for food capture when food is scarce and relatively greater growth of juvenile structures that will function after metamorphosis when food is abundant; however, juvenile structures develop extensively as a rudiment within the echinopluteus prior to settlement and metamorphosis, whereas in ophioplutei there is little development of juvenile structures until metamorphosis. In ophioplutei there is, therefore, less scope for shifting growth to structures that gain function after metamorphosis. Nevertheless, we found that when ophioplutei were at higher concentrations of food, the growth of the posterior coeloms was greater relative to the growth of the larval arms. Developmental plasticity in allocation of growth to larval and postlarval equipment can occur despite disparate patterns of development.AbstractThe catecholamine 3,4-dihydroxyphenethylamine, or dopamine, acts as a neurotransmitter across a broad phylogenetic spectrum. Functions attributed to dopamine in the mammalian brain include regulation of motor circuits, valuation of sensory stimuli, and mediation of reward or reinforcement signals. Considerable evidence also supports a neurotransmitter role for dopamine in gastropod molluscs, and there is growing appreciation for its potential common functions across phylogeny. This article reviews evidence for dopamine's transmitter role in the nervous systems of gastropods. The functional properties of identified dopaminergic neurons in well-characterized neural circuits suggest a hypothetical incremental sequence by which dopamine accumulated its diverse roles. The successive acquisition of dopamine functions is proposed in the context of gastropod feeding behavior (1) sensation of potential nutrients, (2) activation of motor circuits, (3) selection of motor patterns from multifunctional circuits, (4) valuation of sensory stimuli with reference to internal state, (5) association of motor programs with their outcomes, and (6) coincidence detection between sensory stimuli and their consequences. At each stage of this sequence, it is proposed that existing functions of dopaminergic neurons favored their recruitment to fulfill additional information processing demands. Common functions of dopamine in other intensively studied groups, ranging from mammals and insects to nematodes, suggest an ancient origin for this progression.AbstractMany shell-bearing gastropods exhibit pre-capture behaviors when encountering predatory asteroid sea stars. As shown in this meta-analysis of 48 studies on 24 sea star and 100 gastropod and chiton species, almost three-quarters of prey escape by moving or tumbling away, whereas the remaining species clamp tightly to the substratum or otherwise resist. The aim of the present paper is to correlate these behaviors with predicted shell traits, including those with gravitational stability for species that escape on the substratum and those that clamp, and those with a strongly sculptured shell in species that resist sea star attacks. Escaping species and those that clamp have gravitationally stable shells, with the center of gravity located above the broad aperture and large foot. Species that resist have significantly more sculptured shells. All of these traits would also work well in encounters with other slow-moving predators, such as gastropods and planarians. Although the sea stars are generalist predators, and the gastropods have many enemies besides sea stars, cool-water gastropods are well adapted to predatory sea stars on temperate and polar coasts, where most hard-bottom sea stars with molluscan diets occur. The prominence of escape among cool-water gastropods seems contradictory, given that locomotor speed rises with increasing temperature; but tropical gastropods rely more on armor than on escape, because of the prevalence of faster, more powerful predators in warm water. The black pigment of shells of many temperate prey species of sea stars might confer crypsis against these predators.AbstractFollowing traumatic spinal cord injury, most mammalian species are unable to achieve substantial neuronal regeneration and often experience loss of locomotor function. LY3295668 research buy In contrast, larval sea lampreys (Petromyzon marinus) spontaneously recover normal swimming behaviors by 10-12 weeks post-injury, which is supported by robust regeneration of spinal axons. While recovery of swimming behavior is well established, the lamprey's ability to recover more complex behaviors, such as burrowing, is unknown. Here we evaluated the lamprey's ability to burrow into a sand substrate over the typical time course of functional recovery (1-11 weeks post-injury). Compared to uninjured control lampreys, which burrow rapidly and completely, spinal-transected animals did not attempt burrowing until 2 weeks post-injury; and they often did not succeed in fully covering their entire body in the sand. Burrowing behavior gradually improved over post-injury time, with most animals burrowing partially or completely by 9-11 weeks post-injury. Burrowing behavior has two components the initial component that resembles swimming with propagated body undulations and the final component that pulls the tail under the sand. While the duration of the initial component did not differ between control and spinal-transected animals across the entire recovery period, the duration of the final component in spinal-transected animals was significantly longer at all time points measured. These data indicate that, after spinal cord injury, lampreys are able to recover burrowing behaviors, though some deficits persist.AbstractFor many historical and contemporary experimental studies in marine biology, seawater carbonate chemistry remains a ghost factor, an uncontrolled, unmeasured, and often dynamic variable affecting experimental organisms or the treatments to which investigators subject them. We highlight how environmental variability, such as seasonal upwelling and biological respiration, drive variation in seawater carbonate chemistry that can influence laboratory experiments in unintended ways and introduce a signal consistent with ocean acidification. As the impacts of carbonate chemistry on biochemical pathways that underlie growth, development, reproduction, and behavior become better understood, the hidden effects of this previously overlooked variable need to be acknowledged. Here we bring this emerging challenge to the attention of the wider community of experimental biologists who rely on access to organisms and water from marine and estuarine laboratories and who may benefit from explicit considerations of a growing literature on the pervasive effects of aquatic carbonate chemistry changes.Coronavirus disease-2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has abruptly transformed the outlook of employer health benefits plans for 2020 and 2021. Containing the spread of the virus and facilitating care of those infected have quickly emerged as immediate priorities. Employers have adjusted health benefits coverage to make COVID-19 testing and treatment accessible and remove barriers to care in order to facilitate the containment of the disease. Employers also are introducing strategies focused on testing, surveillance, workplace modifications, and hygiene to keep workforces healthy and workplaces safe. This paper is intended to provide evidence-based perspectives for self-insured employers for managing population health during the COVID-19 pandemic. Such considerations include (1) return to work practices focused on mitigating the spread of COVID-19 through safety practices, testing and surveillance; and (2) anticipating the impact of COVID-19 on health benefits and costs (including adaptations in delivery of care, social and behavioral health needs, and managing interrupted care for chronic conditions).The single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) has been introduced in the past few years for the treatment of morbid obesity. SADI-S has shown good results in terms of long-term results and short-term complications. However, the management of patients undergoing SADI-S and suffering from a leak is a great challenge for surgeons. We present an extensive review of the currently available literature on the management of leak after SADI in morbid obese (MO) patients. We aim at providing objective information regarding the optimal management, including diagnosis, technical options for the different strategies that have been proposed, to facilitate the selection of the best individual approach for each MO patient.

This study evaluates the spectrum of visual impairment in stroke survivors.

The Impact of Visual Impairment after Stroke (IVIS) study is a multi-centre, acute stroke unit, prospective epidemiology study. Comprehensive visual examination was offered to all stroke survivors.

1500 stroke admissions were recruited. 1204 stroke survivors had visual assessment. Reduced central vision was documented in 529, visual field loss in 308, ocular motility abnormalities in 533 stroke survivors, visual perception deficits in 59 stroke survivors and visual inattention in 315 stroke survivors. About half, regardless of visual impairment type, were visually asymptomatic. Recovery, whether full or partial, was best for central vision, ocular motility abnormalities and visual perception deficits (about 70% improvement) occurring over a mean follow-up period of 2-3 months.

Incidence of impaired central vision, visual field loss, ocular motility disorders and visual inattention was 29.4%, 24.8%, 39.3% and 26.2% respectivelyatic cases raise concerns for acute stroke units where robust specialist vision screening is not routine. Those with partial/no recovery require specialist follow-up and management whilst the wide range of abnormalities highlight the need for specialist visual assessment acutely.Implications for rehabilitationVisual impairment is a common consequence of stroke.Incidence of visual impairment is about 60%.Significant numbers of stroke survivors are visually asymptomatic, highlighting the need for standardised vision assessments.Many stroke survivors have persistent long-term visual impairment, necessitating referral and access to specialist eye care services.

Illness narratives are cultural artifacts that reflect the ways through which a certain culture perceives and constructs a given illness. Against this backdrop, the study explored the social construction of MS in Israeli society.

Thematic content analysis of all (70) illness narratives posted on the Israel MS Society's website between 2012-2018, was employed.

Five themes were identified in our analysis, according to chronological order (1) "Becoming ill" - consisted of framing MS as a sudden affliction or constructing MS as a gradual development. (2) "Negative changes" depicted MS as inflicting negative bodily changes and a disruption to the social order. The "happy ending" of the narratives pertained to (3) "adjustments" to MS and, (4) "never giving up" to MS. These were facilitated by embracing (5) "positive thinking and optimism."

MS is perceived in Israel as a form of "deviance" and as a biomedical phenomenon. Rehabilitation and healthcare staff, therefore, need to actively engage in interventions that challenge and change the ways that MS is perceived, as well as to partner with people with MS, and disability advocates to reconstruct and design policies and services that reflect a more socio-political understanding of MS.