The algae Ulva lactuca and Gracilaria parvispora are abundant in the Gulf of California, rich in nutrients, and may be used as a source of protein in balanced diets for shrimp. This study tests ...whether their meal, as a partial inclusion in diets for juvenile Litopenaeus vannamei, is feasible. Percentages of inclusion were 5, 10, and 15 %. Results showed that final weight, weight gain, and specific growth rate varied significantly among diets (P < 0.05). There were significant differences in growth among the trials of amount of inclusion of meal when using U. lactuca (P < 0.05), and no significant differences among the trials when using G. parvispora (P > 0.05). In general, better results were obtained when using G. parvispora compared with U. lactuca. When compared to the control diet (without inclusion), diets that included 10 and 15 % U. lactuca meal yielded a significantly lower growth (P < 0.05), but no significant differences were detected when using U. lactuca 5 % meal (P > 0.05), suggesting the feasibility of inclusion to this limited percentage. No significant differences were detected between the control and the three treatments with G. parvispora, suggesting the possibility of using higher percentages of inclusion. We conclude that both seaweeds may be used as a component in preparing feed for juvenile L. vannamei.
Photosynthetic and respiratory responses (P–E curves) of Gracilaria parvispora from the southeast Gulf of California were studied at four temperatures (20, 25, 30, 35 °C) and salinity (25, 30, 35, 40 ...psu) combinations. The alga showed acclimation in its photosynthetic and respiratory responses to tropical temperature as well as to oceanic salinity. A positive effect of temperature on photosynthetic rate (P ₘₐₓ) was observed for all salinities. Photosynthetic rates for treatments at 20 and 25 °C were lower (<9.2 mg O₂ g dry weight (dw)⁻¹ h⁻¹) than for treatments at 30 and 35 °C (>12 mg O₂ g dw⁻¹ h⁻¹). G. parvispora showed limited tolerance to low salinities (25 psu) and low temperatures (20 °C) and the interaction between temperature and salinity was significant (analysis of variance, P < 0.05). Responses to salinity indicated adaptation to oceanic salinity. Photosynthetic responses were lower at 25 psu than at higher salinities. The lowest P ₘₐₓ values (6.2–8.2 mg O₂ g dw⁻¹ h⁻¹) were observed at the lowest salinity (25 psu) regardless of temperature. Compensation and saturation irradiances (26–170 and 57–149 μmol photons m⁻² s⁻¹, respectively) indicate adaptation to lower irradiances in shallow (1–2 m depth) habitats, where turbidity can be high, and the capacity of shade adaptation has been developed. Results suggest distribution of this species is mainly related to salinity or temperature. The potential mariculture efforts of G. parvispora would be limited by low temperatures in winter, and indicate that this species will probably not be able to spread further due to low temperatures (<15 °C) in the upper part of the Gulf of California.
Abstract
Gracilaria parvispora
is reported for the first time as an invasive species in northwestern Mexico based on morphological, anatomical and molecular data. The species is widely distributed in ...the region, where it colonizes sandy and rocky habitats from intertidal areas down to a depth of 1.5 m. The morphological and anatomical data from the Mexican specimens matched the circumscription of the species in Hawaiian waters. Two molecular markers (
rbc
L and
cox
1) showed that the Mexican populations were closer to the Hawaiian populations than the Korean populations, which may relate to a similarity in seawater temperatures between Hawaii and Baja California.
Gracilaria parvispora
formed extensive mats together with
Gracilaria vermiculophylla.
It was found in stomach samples from a green turtle (
Chelonia mydas
) in the coastal lagoons of Baja California Sur. The ecological impacts of the two alien
Gracialria
species on other native species and communities have yet to be determined. This is the first demonstration of a second invasive
Gracilaria
species, following the introduction of
G. vermiculophylla
into the northwestern Mexico region.
Triploid Crassostrea gigas were cultured during 13 months in Nestier-type oyster trays. The impact of environmental parameters on the physiological and immunological parameters was evaluated. ...Temperature, salinity and seston were recorded monthly. Seventeen oysters were sampled monthly for immunological and condition index (CI) analyses. Samples were obtained as a haemolymph lysate supernatant (HLS). Protein content was determined using the Bradford method. The activity of hydrolytic enzymes was determined using the API ZYM kit and the lysoplate assay. Seston showed different patterns throughout the cycle. Condition index showed a positive correlation with the protein content of HLS. Protein showed a negative correlation with temperature. Eleven hydrolytic enzymes were detected in samples and higher enzymatic activity corresponded to leucine arylamidase and esterase. Leucine arylamidase and lysozyme activity showed a positive correlation with temperature. Oyster mortality was 28% in our modules and 70% in the oyster farm. Oysters showed low values of CI and haemolymph protein content in summer-autumn when mortalities were observed in the culture system. This finding suggests that these stressed oysters may have insufficient energy to invest in their immune system. It appears that oyster mortality in the culture system resulted from a combination of animal overcrowding, high temperature and low salinity.
Agar properties of two potentially commercial important seaweeds from the Gulf of California were studied. Maximum yield in Gracilaria vermiculophylla (45.7%) occurred during the summer months, ...coinciding with high water temperatures (31°C) whereas minimum yields (11.6%) were obtained during the coldest months of the year when populations of this species diminish in the bay. Gracilariopsis longissima showed two yield peaks, one in spring and another in fall, before the maximum and minimum seawater temperatures. Gel strength in native agar from the two species was low (<22.5 g cm⁻²) for most of the year. G. vermiculophylla native agar showed a slight increase in gel strength from June to August, which were the hottest months. Maximum value was 85 g cm⁻¹ in August. Maximum gel strength in G. longissima was observed in October (91 g cm⁻¹), and an unusual native agar with no detectable gel strength was observed in March and April samples. Gelling temperatures range from 27.7 to 36.5°C in G. vermiculophyla and from 26.6 to 34.9°C in G. longissima, meanwhile melting points were 73.9 - 53.5°C and 75.5 - 56.6°C, respectively. Sulfate content was high, 6.3-13.9% in G. vermiculophylla and 1.9-11.9% in G. longissima, and on the other hand 3,6 anhydrogalactose content was low 12.1-26.7% and 9.1-23%, respectively compared to other species. Results obtained showed that mean native agar yields of Gracilaria vermiculophylla and Gracilariopsis longissima from the Gulf of California are comparable to other tropical Gracilaria. However, the low gel strength, high sulfate content and low 3,6 anhydrogalactose content observed in the native agar extracted from these species make this an agaroid, thus alternative methods of extraction should be used to evaluate the possibility of commercial utilization of both species.
Salmonella is one of the main microorganisms that causes food-borne illnesses worldwide, although there are standard procedures to determine its presence or absence in food samples. However, these ...methodologies are time consuming and cumbersome, so the development of devices that rapidly and accurately determine bacteria is necessary. Various materials have been used to construct these devices. Hydrogenated amorphous silicon carbide (a-SiC:H) is one of the least studied. Therefore, in the present work, self-assembled monolayers were applied on a-SiC:H thin films to determine Salmonella Typhimurium ATCC 14028 by Fourier transform infrared spectroscopy. The detection of this microorganism was performed between 1060 and 960 cm
−1
corresponding to carbohydrate and phosphate groups of the bacteria. The lowest detected concentration was 10 CFU/mL. This work confirms the utility of a-SiC:H to reliably and rapidly determine Salmonella.
Highlights•The WHO recommends dengue vaccine in highly endemic areas as part of integrated management strategy. •Serostatus and age at the time of vaccination are main drivers of vaccine efficacy. ...•Main conclusions of the 6 th IDI Meeting for dengue vaccine introduction in the region are discussed. •A dengue vaccine program entails consensual public health strategies and robust communication.
Pituicytomas are rare entities which develop in the neurohypophysis. They were included in the last World Health Organization (WHO) Classification of Central Nervous System Tumours in 2007, but for ...many years they have been confused with other pituitary tumours. We report the case of a 31-year-old woman who was diagnosed of a tumour in the suprasellar region during an infertility study due to hypogonadotropic hypogonadism and slight hyperprolactinemia. A standard pterional approach was performed, achieving total tumour excision. After the surgery the patient suffered bitemporal hemianopsia, diabetes insipidus and panhypopituitarism, although she recovered from the latter 2 in a few weeks. We conducted a review of the most common clinical and radiological features of this entity, as well as the treatments proposed in the literature to treat this rare tumour.
Ocio e interculturalidad Barón Del Pópolo, Guillermo; Bedmar Moreno, Matías; Bravo, Cristóbal ...
Polis (Santiago, Chile : 2001),
12/2010
Journal Article
Odprti dostop
La Universidad Bolivariana (UB), en su continua búsqueda de conocimientos innovadores, relevantes y actuales, viene trabajando con la Universidad Federal de Minas Gerais (UFMG), de Brasil, en el ...Programa de investigación titulado “Ocio, Tiempo libre y Recreación en Latino América: Desafíos para el siglo XXI / Lazer na América Latina: Desafios para o século XXI”. A partir de este Convenio de Cooperación UB-UFMG es que desde el Grupo de Investigación OTIUM: Lazer, Brasil & América Latina, de la UFMG, se está avanzando en un campo de estudios relativamente nuevo y poco profundizado: la temática del “ocio”. Desde aquí nace este actual número de Polis que presentamos. Es así que en este número de Polis queremos aportar en este proceso de generación de nuevos conocimientos, debates y diálogos, sabiendo que el ocio y la interculturalidad expresan algo de las emergentes identidades y diversidades globales y locales, algo que sin duda debe ser expresado y escuchado.
