Giant clams are bivalves found across Indo-Pacific coral reefs and intensively harvested for both food and marine aquarium trade markets. Aquaculture protocols are well established, but there is very ...little data available on production and trade. This review compiled data from several international agencies and from each one of the 20 giant clam farms active in 13 countries in the Indo-Pacific. The findings show that the import/export data do not match, and that approximately 50% of internationally traded clams are aquacultured. Approximately 150,000 individuals were produced in 2015, mostly by private companies targeting the aquarium trade. Government hatcheries produced clams not only for the aquarium trade, but also for restocking and feeding local communities. However, production is still low and only three of the 20 farms collaborate with universities or research institutions and all of them reported production problems related to technical, commercial, infrastructure, and environmental issues. In order to fight such problems and optimize production, it is important that producers, universities, and government agencies throughout the world communicate with each other.
Many species of reef-building corals are mixotrophic, relying on both photoautotrophy performed by their dinoflagellate symbionts and heterotrophy from consumption of zooplankton. Autotrophy and ...heterotrophy supply corals with specific
ω
3 fatty acids, which can be used as trophic markers and record the contribution of each feeding strategy. This study investigated whether the reef-building coral
Mussismilia hispida
, endemic to Brazil, is able to shift between predominantly autotrophic and predominantly heterotrophic by monitoring the concentration of fatty acids in the host tissue. We then examined whether shifts are related to changes in temperature and wind stress. For that purpose,
M. hispida
colonies were monitored for a year with monthly tissue sampling. Symbiont concentration was determined and lipid extraction performed. Four fatty acids were quantitatively analyzed by gas chromatography with flame ionization detector: the autotrophy markers: stearidonic acid (SDA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and a heterotrophy marker: cis-gondoic acid (CGA). Three preliminary experiments confirmed the specificity of SDA, DPA and CGA, but not of DHA. Shifts of predominance occurred multiple times during the year and were associated with minimal temperatures and wind stress. Colonies underwent mild bleaching during summer months, which they seemed to compensate with heterotrophic feeding. Our major findings include the validation of three FATM and a trophic index for coral reef ecology studies and also describing the in situ occurrences of shifts between feeding modes, while highlighting the role of temperature and meteorological events.
Coral reefs are diverse ecosystems relying on the presence of dinoflagellates (genus
Symbiodinium
), that are found in symbiotic association with multiple phyla and performing the majority of primary ...production. However, coral reefs are currently threatened by climate change and the increase in seawater temperature, which causes the bleaching phenomenon. While bleaching has been well documented for adult host organisms, it is still poorly understood in larval stages. We offered
Symbiodinium
types within clades A–F to the larvae of
Mussismilia hispida
(scleractinian coral),
Berghia stephanieae
(nudibranch) and
Tridacna crocea
(giant clam) and manipulated the temperature to 26, 29 or 32 °C. Samples were taken at 0, 12, 24, 48 and 72 h post-temperature increase, chlorophyll-
a
(chl-
a
) was extracted and its content measured in a fluorometer.
Symbiodinium
type, temperature and time all influenced chl-
a
content.
M. hispida
larvae displayed a bleaching threshold at 29 °C; larvae containing
Symbiodinium
A–F all bleached at 32 °C, but with significantly lower bleaching in larvae associated with type A1.
B. stephanieae
digested the symbionts; while chl-
a
content decreased over time equally for all clades, it is not possible to determine if it is related to bleaching.
T. crocea
larvae at 29 °C bleached for all symbiont types, except for A1. At 32 °C, all types were bleached, but type A1 bleached significantly less. These findings show that type A1 seems to be more thermo-tolerant in larvae of the tested species. This may be related to the fact that strains within this clade are homologous to both
M. hispida
and
T. crocea
, as they are found within these adult host’ tissues. Therefore, symbiont type may have an important role in invertebrate larvae development and present relevant implications for recruitment.
Temporal and spatial fluctuations of environmental parameters are normally assigned as causes of variations in morpho-phenological characters of seaweeds and in their epibionts, but formal tests of ...such hypotheses are lacking, especially in narrow gradients. The present study evaluated the influence of a very small depth gradient (1 to 3 m) and of subtle seasonality characteristic of tropical areas on morpho-phenological traits and on the occurrence of sessile epiphytic organisms using a controlled orthogonal sampling design in a sublittoral population of the tropical brown alga Sargassum cymosum. Four temporal samples were obtained over a one-year period at three depths using nine replicates. The wet weight, maximum length, number of primary and secondary branches, and proportion of secondary branches with receptacles were recorded. Epibiosis was estimated by visual evaluation of percentage cover on secondary branches. Algal morphology varied as a function of the period of the year (weaker effect) and depth (stronger effect) but in different ways for each variable analysed. In general, fronds tended to be shorter, heavier, and more ramified in shallower areas. In relation to time, the morphological characters tended mostly to present higher values in January (summer) and/or April (autumn). Frequency of receptacles did not depend on algal morphology and depth at all but varied in time, although only in the deepest area. Epibiosis also did not depend on algal morphology but varied in relation to time (stronger effect) and, to a lesser extent, depth (weaker effect). The effect of time upon epibiosis also depended on the biological group analysed. These data support the hypothesis that algal morphology varies in relation to period of the year and depth, even under small temporal and spatial environmenal gradients.
► The cube texture as a typical sheet texture can also be formed by cold drawing and recrystallization in profile wires. ► Cube textured Ni profile wires containing up to 96.2% cube oriented grains ...in the central region were obtained. ► Forthcoming investigations are promising to get a textured substrate wire for YBCO-coated conductors.
Cube textured nickel alloy tapes prepared by cold rolling and annealing (RABiTS method) represent a standard metallic substrate for superconductor coatings of the YBa
2Cu
3O
7−
δ
(YBCO) type. These tapes have a width to thickness ratio of about 30–100. However, a value of close to one is optimal concerning low energetic losses under alternating current applications. First experiments on micro-alloyed nickel prove that the cube texture as a typical sheet texture can also be formed in profile wires with a rectangular cross-section after cold drawing and recrystallization treatment.
Symbiodinium
are dinoflagellates engaged in a mutualistic symbiosis with multiple coral reef taxa. They are divided in nine different clades (A–I), which typically associate with different hosts. ...However, very little information is available on metabolic differences in
Symbiodinium
types, especially when associated with metazoan larvae. We tested whether three ω3 fatty acids (stearidonic acid, SDA; docosapentaenoic acid, DPA; and docosahexaenoic acid, DHA) that are typically translocated from
Symbiodinium
to its host are produced by
Symbiodinium
types within clades A–F associated with
Mussismilia hispida
(scleractinian coral),
Berghia stephanieae
(nudibranch), and
Tridacna crocea
(giant clam) larvae. We acquired and spawned broodstock for each host, cultured their larvae, and offered
Symbiodinium
types belonging to clades A–F. Samples were taken during a 72-h window after the offer of
Symbiodinium
, and fatty acids were extracted and analyzed by gas chromatography. The concentrations of SDA and DPA for all host larvae–dinoflagellate associations were low and variable, without trends. However,
M. hispida
planula larvae associated with
Symbiodinium
A1 and C1 had a statistically significant higher amount of DHA. The veliger larvae of
B. stephanieae
digested the
Symbiodinium
, and the amount of DHA remained constant throughout the experiment. The veliger larvae of
T. crocea
associated with
Symbiodinium
A1 and C1 also presented a higher amount of DHA, although not statistically different from the other types. These results show that
Symbiodinium
A1 and C1, in the case of
M. hispida
and
T. crocea
(which usually harbor strains within clades A and C), may contribute a small amount of DHA to the larvae of these organisms and form a stronger mutualism than other strains.
High-strength in situ composites with enhanced ductility were prepared by various casting methods from Zr–Nb–Cu–Ni–Al alloys related to bulk metallic glass compositions. The composites exhibit a ...bimodal size distribution consisting of bcc β-Zr dendrites stabilized by the addition of Nb and a nanocrystalline/amorphous matrix. The dendrite and matrix crystallite size and the morphology depend sensitively on casting conditions. The cooling rates estimated from the secondary dendrite arm spacing of the Zr
73.5Nb
9Cu
7Ni
1Al
9.5 alloy vary between
ϵ≈2.6×10
3
K/s to 4.0×10
1
K/s. The effect of processing parameters on the mechanical properties is less significant for the Zr
66.4Nb
6.4Cu
10.5Ni
8.7Al
8.0 alloy while highly pronounced for the Zr
73.5Nb
9Cu
7Ni
1Al
9.5 alloy, where optimum properties like fracture stress of 1754 MPa and 17.5% strain to failure were achieved for cast rods 10 mm in diameter. The deformation of the composite proceeds partly through dislocation movement in dendrites and a shear banding mechanism in the nanostructured matrix.
The Southwestern Atlantic harbors unique reef environments with high proportions of endemic species. The most prominent reefs are located in the Abrolhos Bank, a 46,000 km2 extension of the South ...American continental shelf. However, just 100 km north of Abrolhos is the Royal Charlotte Bank (RCB), an area still poorly investigated. From a biological perspective, the only scientific information available is the historical record of lobster fisheries in the region. Hence, we performed an expedition to investigate what macrohabitats are found in the RCB and perform a preliminary biodiversity assessment. A dropcam was deployed in 67 sites and recorded images of macrohabitats and associated biodiversity. Four different macrohabitats were detected: rhodolith beds, macroalgal forests associated with rhodolith beds, calcareous sand deposits and coral reefs. The former two were the most frequent, and both rhodolith and macroalgae densities were higher on the outer shelf. A total of 83 species of fish, invertebrates and algae were identified, which comprises a comparatively high diversity for visual reef biodiversity assessments in the Southwestern Atlantic. Our findings show that the RCB is a large and diverse ecosystem complex mostly composed of rhodoliths, and also that it may be already undergoing anthropogenic impacts associated with climate change and fisheries. Therefore, further investigations are necessary to understand the extent of biodiversity and its main threats and evaluate the possible need of conservation and management measures.
Display omitted
•The RCB is an ecosystem complex composed of at least four different macrohabitats.•Rhodolith beds encompass most of the RCB, and density is higher on the outer shelf.•Diversity is similar to SWA reef hotspots, including endemic and endangered species.•There is evidence of anthropogenic impacts associated with climate change.•Despite historical fishery activity, stock assessments are still lacking.
Underuse of adjuvant therapy is a potentially important and remediable explanation for the inferior survival of minority women with breast cancer. We sought to measure a racial disparity in the ...underuse of adjuvant treatments for early-stage breast cancer and to identify associated factors.
Cross-sectional study with review of all inpatient and outpatient medical records of 677 women treated surgically for a primary American Joint Committee on Cancer stage I or II breast cancer in 1999 to 2000. Underuse was defined as omissions of radiation therapy after breast-conserving surgery, adjuvant chemotherapy after resection of hormone-receptor-negative tumors > or = 1 cm, or hormonal therapy for receptor-positive tumors > or = 1 cm.
One hundred forty-five (21%) of 677 women experienced underuse of appropriate adjuvant therapy: 16% in whites, 34% in blacks, and 23% in Hispanics (P < .001). Women referred to medical oncologists were less likely to experience underuse of necessary adjuvant treatments (relative risk RR for underuse = 0.2; 95% CI, 0.1 to 0.3). Women who were minorities (RR = 2.0; 95% CI, 1.3 to 3.1), had higher levels of comorbidity (RR = 1.4; 95% CI, 1.1 to 1.8) and lacked insurance (RR = 1.9; 95% CI, 0.9 to 4.0) were at greater risk for underuse.
Minority women with early-stage breast cancer have double the risk of white women for failing to receive necessary adjuvant treatments despite rates of oncologic consultation similar to those for white women. Oncology referrals are necessary to reduce treatment disparities but are not sufficient to ensure patients' receipt of efficacious adjuvant treatment.
