48 research outputs found
Simultaneously Hermaphroditic Shrimp Use Lipophilic Cuticular Hydrocarbons as Contact Sex Pheromones
Successful mating is essentially a consequence of making the right choices at the correct time. Animals use specific strategies to gain information about a potential mate, which is then applied to decision-making processes. Amongst the many informative signals, odor cues such as sex pheromones play important ecological roles in coordinating mating behavior, enabling mate and kin recognition, qualifying mate choice, and preventing gene exchange among individuals from different populations and species. Despite overwhelming behavioral evidence, the chemical identity of most cues used in aquatic organisms remains unknown and their impact and omnipresence have not been fully recognized. In many crustaceans, including lobsters and shrimps, reproduction happens through a cascade of events ranging from initial attraction to formation of a mating pair eventually leading to mating. We examined the hypothesis that contact pheromones on the female body surface of the hermaphroditic shrimp Lysmata boggessi are of lipophilic nature, and resemble insect cuticular hydrocarbon contact cues. Via chemical analyses and behavioural assays, we show that newly molted euhermaphrodite-phase shrimp contain a bouquet of odor compounds. Of these, (Z)-9-octadecenamide is the key odor with hexadecanamide and methyl linoleate enhancing the bioactivity of the pheromone blend. Our results show that in aquatic systems lipophilic, cuticular hydrocarbon contact sex pheromones exist; this raises questions on how hydrocarbon contact signals evolved and how widespread these are in the marine environment
Shrimps from the Santana Group (Cretaceous: Albian): new species (Crustacea: Decapoda: Dendrobranchiata) and new record (Crustacea: Decapoda: Caridea)
Ecophysiological studies on the developing eggs and embryos of the European lobster Homarus gammarus
Influence of estuarine hypoxia on feeding and sound production by two sympatric pipefish species (Syngnathidae)
A Review of the Trachysalambria curvirostris Species Group (Crustacea : Decapoda : Penaeidae) with Description of a New Species
Bioluminescence in Dinoflagellates: Evidence that the Adaptive Value of Bioluminescence in Dinoflagellates is Concentration Dependent
New record of occurrence ofSergia lncens (Hansen) (crustacea, sergestidae) off Tung-kang, Taiwan, with special reference to phylogeny and distribution of the species
Bioluminescence in a Complex Coastal Environment: 2. Prediction of Bioluminescent Source Depth From Spectral Water-leaving Radiance
Many bioluminescence observations are made from the ocean\u27s surface. However, the depth of the bioluminescent source is difficult to estimate on the basis of surface observations alone, given the variable light attenuation of unknown concentrations of water column constituents such as phytoplankton, colored dissolved organic matter, and detritus. Part 1 of this paper showed that bioluminescent water-leaving radiance signals are detectable, even in extremely turbid and dynamic coastal waters. Here, in part 2 of this paper, we analyze the water-leaving radiance patterns of bioluminescence modeled by HydroLight 4.2 to determine if the depth of the bioluminescent source can be estimated from its spectral signature. We find that the depth of the bioluminescent source is contained within the spectral signal and can be elucidated by simple neural networks. These networks can predict the depth of a bioluminescent layer with great accuracy, solely on the basis of the spectral shape of bioluminescent water-leaving radiance in a variety of water column and bottom type conditions. In addition, we found that as little as three wavelengths from the spectrum of water-leaving radiance are sufficient for an accurate determination of the depth of the bioluminescent source
Recommended from our members
A signal-finding study of nivolumab and relatlimab in patients with advanced chordoma
11578 Background: Chordomas are derived from notochordal remnants and are typically treated with surgery and radiation therapy. For advanced chordomas, there are no approved systemic therapies. Preclinical evidence and anecdotal reports have indicated that the immune system is active in chordomas and that there may be a role for immunomodulation in treating this disease. Methods: This study is a single-arm, signal-finding trial in patients with advanced chordoma treated with the anti PD-1 antibody nivolumab (480 mg Q4 weeks up to 2 years) and the anti-LAG3 antibody relatlimab (160 mg Q4 weeks up to 2 years). The primary objective of this study was to assess the safety of nivolumab and relatlimab in subjects with progressive metastatic or locally advanced/unresectable chordoma. Secondary objectives were to ascertain the median progression free survival (PFS), response rate (RR), and the 4- and 6-month PFS by RECIST 1.1. Results: Out of a planned enrollment of 20 patients, 10 patients (8 Male, 2 Female) were consented and treated on trial. Enrolled patients had the following sites of involvement: 5 clival/c-spine, 4 sacral, and 1 thoracic. Nine had conventional subtype chordoma and 1 had chondroid subtype. Eight of the 10 patients had previous surgery, 6 had previous radiation therapy and 5 had 1-2 lines of prior systemic therapy, including one who received pembrolizumab. Pretreatment biopsies were obtained from 9 out of 10 patients and blood has been collected on all patients. Nine patients were evaluable for study outcomes. A total of 64 AEs (Grades 1-4) have been noted to date, with 6 events being classified as grade 3-4: nausea, facial pain, headache, and pulmonary embolism. Five serious adverse events (SAEs) were noted in patients on treatment: headache (2), asthma (1), myocarditis (1), and sepsis (1). The median PFS of the 9 evaluable patients was 21.4 weeks. At 4 months, 7 out of 9 patients were progression free (77.7%). At 6 months, 4 out of 9 patients remained progression free (44.4%) and had continued progression-free survival at 1 year. One out of 9 (9.1%) patients had a PR via RECIST 1.1. One patient discontinued treatment due to an adverse event (grade 1 myocarditis). Conclusions: This signal-finding study indicated that some patients with advanced chordomas can receive benefit with relatlimab in combination with nivolumab. The combination was well-tolerated and no new safety signals were found in this rare patient population. Correlative studies are ongoing. The study was closed for slow accrual. Clinical trial information: NCT03623854