Gene expression and energetic metabolism changes in the whiteleg shrimp (Litopenaeus vannamei) in response to short‐term hypoxia     

Sergio Alan Ulaje  Liliana Rojo‐Arreola  Salvador E. Lluch‐Cota  Felipe Ascencio  Pedro Cruz‐Hernndez  María Teresa Sicard 《Aquaculture Research》2019,50(4):994-1004

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A dynamic simulation analysis of Japanese abalone (<Emphasis Type="Italic">Haliotis discus hannai</Emphasis>) production in Chile     

Sergio Zúñiga 《Aquaculture International》2010,18(4):603-620

In this paper the author develops a dynamic simulation model and uses it to analyze the economics of pond cultivation of Japanese abalone in Chile. The analysis is done in continuous time by defining discounted free cash flows on the basis of explicit relationships between several biological, technical, and economic functions. In a culture batch starting with 600,000 seedlings when abalone has an average length of 19 mm, and the optimal harvest time is day 763 from stocking, harvesting at that optimum time implies a per-unit cost of production of approximately CH$320 per abalone. This includes consumption of 443,644 kg algae per generation, providing approximately 1.46 kg algae per abalone, and an electric energy requirement of about 433,200 kWh. Even at the optimum time of harvest, the profits are rather low. This explains why Japanese abalone culture has been substantially reduced in the north of Chile. To obtain abalones with an average weight of 100 g, harvest should be on day 1,460, when operating net present value is negative. In addition, the effect of changes of some key parameters on the results is analyzed via a sensitivity analysis.  相似文献   

Colletotrichum species causing anthracnose on avocado fruit in Mexico: Current status     

Dionicio Fuentes-Aragón  Hilda V. Silva-Rojas  Vladimiro Guarnaccia  José A. Mora-Aguilera  Sergio Aranda-Ocampo  Néstor Bautista-Martínez  Daniel Téliz-Ortíz 《Plant pathology》2020,69(8):1513-1528

Colletotrichum species cause anthracnose disease in tropical and subtropical fruit crops worldwide. Mexico is the main producer and exporter of avocado (Persea americana) globally and has yearly outbreaks of anthracnose on this crop. However, which specific Colletotrichum spp. cause these outbreaks in avocado-producing regions remain uncertain; thus, the objective of the present study was to identify the species responsible. A survey performed in six production regions of Mexico yielded 232 isolates, from which a subset of 104 strains was selected based on morphological characteristics and origin. This subset was sequenced and haplotypes were analysed in the gapdh partial gene. Finally, 31 strains were identified through multilocus phylogenetic analyses using the sequences of the internal transcribed spacer region and six loci. This study revealed the presence of two species previously reported in Mexico (C. karsti and C. godetiae), three novel records in Mexico (C. siamense, C. fioriniae, and C. cigarro), four novel records on avocado (C. chrysophilum, C. jiangxiense, C. tropicale, and C. nymphaeae), and two novel lineages (Colletotrichum sp. 1 and Colletotrichum sp. 2). C. siamense was the most prevalent, while the species reported for the first time on avocado, including the novel lineages, were the least prevalent. C. karsti was the most widespread (four regions), followed by C. siamense, C. jiangxiense, and C. chrysophilum (three regions). Pathogenicity tests showed that all species caused anthracnose on avocado fruit. These findings will be useful for improving the management of avocado anthracnose outbreaks in Mexico.  相似文献   

Common bile duct obstruction due to a duodenal gastrinoma in a dog     

Vergine M  Pozzo S  Pogliani E  Rondena M  Roccabianca P  Bertazzolo W 《Veterinary journal (London, England : 1997)》2005,170(1):141-143

In dogs gastrinomas are rare endocrine neoplasms that have always been reported to arise from the pancreas. We report here what we believe to be the first case of a duodenal gastrinoma in a dog. A nine-year-old, male, Pekinese dog was presented with a three-day history of anorexia, vomiting and mucous diarrhoea. Clinical examination and laboratory findings suggested the presence of a severe hepatobiliary disorder. Abdominal ultrasonography showed a diffuse increase in echogenicity of the liver, with severe gallbladder dilation and marked dilation of the cystic duct, common bile duct and extrahepatic bile ducts. Based on these findings, an extrahepatic biliary tract obstruction (EBTO) of unknown cause was suspected. At laparotomy, the gallbladder and the extrahepatic bile ducts appeared severely dilated. The gallbladder was tense and could not be compressed suggesting an outflow obstruction. The duodenum at the level of the common duct orifice appeared slightly thickened and severely hardened for a length of 1 cm. Biopsies from the duodenum and liver were obtained and a cholecystoduodenostomy was performed. The duodenal biopsy revealed severe fibrosis of the submucosa and a infiltrate of small pockets and cords of round to polygonal cells with granular cytoplasm. Based on this appearance the differential diagnoses included neuroendocrine tumours and poorly differentiated carcinoma. Despite surgery and supportive therapy the dog continued to be anorexic and to vomit 3-6 times daily. After euthanasia and necropsy, histopathology showed the presence of a neuroendocrine neoplasia involving the duodenal wall with focal invasion of the adjacent pancreas and small liver metastases. On immunohistochemistry, the cytoplasm of approximately 90% of neoplastic cells intensely expressed neuron specific enolase and gastrin. These findings were consistent with a diagnosis of gastrinoma.  相似文献   

The impact of sugarcane filter cake on the availability of P in the rhizosphere and associated microbial community structure     

Bruna Arruda  Marcos Rodrigues  Thiago Gumiere  Alan E. Richardson  Fernando Dini Andreote  Amin Soltangheisi  Luciano Colpo Gatiboni  Paulo Sergio Pavinato 《Soil Use and Management》2019,35(2):334-345

This study aimed to evaluate the interaction between filter cake (FC), and phosphorus fertilizers with differing solubility on the growth and P nutrition of sugarcane. Effects of soil amendment with FC on different soil P fractions and influence on microbial community structure in the rhizosphere were also assessed. Two glasshouse experiments were conducted with completely randomized block designs. The first experiment evaluated rates of FC using a factorial design (5 × 2): 0, 2.5, 5, 10 and 15 g FC kg^?1 soil applied as either broadcast in bulk soil or in the planting furrow. The second experiment used a factorial design (2 × 3): without and with FC (5 g kg^?1 soil, dry basis), both without P (NP) and with P supplied as either triple superphosphate (TSP) or as rock phosphate (RP), both at the rate of 78.4 mg kg^?1 based on total P. Microbial community structure was determined using TRFLP and dynamics of soil P by Hedley fractionation. Filter cake applied at increasing rates in the absence of P was effective in increasing shoot growth and P uptake by plant, particularly when applied to bulk soil as compared to furrow application. Also, FC improved P uptake and increased the availability of labile inorganic P in the rhizosphere and modified the structure of fungal and bacterial communities, whereas only bacterial and archaea communities were influenced by P fertilizer use. Filter cake was more effective when combined with RP, with increased growth and P utilization and thus can be considered as a feasible and practical option for farmer use in substitution to TSP, a more expensive source.  相似文献   

Immunization with Eimeria ninakohlyakimovae-live attenuated oocysts protect goat kids from clinical coccidiosis     

Antonio Ruiz  María Carmen Muñoz  José Manuel Molina  Carlos Hermosilla  Marisa Andrada  Pedro Lara  Elisa Bordón  Davinia Pérez  Adassa María López  Lorena Matos  Aránzazu Carmen Guedes  Soraya Falcón  Yaiza Falcón  Sergio Martín  Anja Taubert 《Veterinary parasitology》2014,199(1-2):8-17

Caprine coccidiosis, affecting mainly young goat kids around the weaning period, is worldwide the most important disease in the goat industry. Control of caprine coccidiosis is increasingly hampered by resistances developed against coccidiostatic drugs leading to an enhanced need for anticoccidial vaccines. In the current study we conducted an oral immunization trial with live attenuated sporulated Eimeria ninakohlyakimovae oocysts. Sporulated E. ninakohlyakimovae oocysts were attenuated by X-irradiation technique. The experimental design included a total of 18 goat kids divided into the following groups: (i) animals immunized with attenuated E. ninakohlyakimovae oocysts at 5 weeks of age and challenged 3 weeks later with non-irradiated homologous oocysts (group 1); (ii) animals infected with non-attenuated E. ninakohlyakimovae oocysts at 5 weeks of age and challenged 3 weeks later with non-attenuated homologous oocysts (group 2); (iii) animals primary-infected with untreated E. ninakohlyakimovae oocysts at 8 weeks of age (control of the challenge infection, group 3); (iv) non-infected control animals (group 4). Goat kids immunized with live attenuated E. ninakohlyakimovae oocysts (group 1) excreted significantly less oocysts in the faeces (95.3% reduction) than kids infected with non-attenuated ones (group 2). Furthermore, immunization with live but attenuated oocysts resulted in ameliorated clinical coccidiosis compared to goat kids infected with untreated oocysts (group 2) and resulted in equally reduced signs of coccidiosis after challenge infection compared to acquired immunity driven by non-attenuated oocysts. Overall, the present study demonstrates for the first time that live attenuated E. ninakohlyakimovae oocysts orally administered showed almost no pathogenicity but enough immunogenicity in terms of immunoprotection. Importantly, vaccinated animals still shed low amounts of oocysts, guaranteeing environmental contamination and consecutive booster infections to sustain ongoing immunity.  相似文献   

Hereditary early-onset Parkinson's disease caused by mutations in PINK1     

Valente EM  Abou-Sleiman PM  Caputo V  Muqit MM  Harvey K  Gispert S  Ali Z  Del Turco D  Bentivoglio AR  Healy DG  Albanese A  Nussbaum R  González-Maldonado R  Deller T  Salvi S  Cortelli P  Gilks WP  Latchman DS  Harvey RJ  Dallapiccola B  Auburger G  Wood NW 《Science (New York, N.Y.)》2004,304(5674):1158-1160

Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra. We previously mapped a locus for a rare familial form of PD to chromosome 1p36 (PARK6). Here we show that mutations in PINK1 (PTEN-induced kinase 1) are associated with PARK6. We have identified two homozygous mutations affecting the PINK1 kinase domain in three consanguineous PARK6 families: a truncating nonsense mutation and a missense mutation at a highly conserved amino acid. Cell culture studies suggest that PINK1 is mitochondrially located and may exert a protective effect on the cell that is abrogated by the mutations, resulting in increased susceptibility to cellular stress. These data provide a direct molecular link between mitochondria and the pathogenesis of PD.  相似文献   

Raptor nest decorations are a reliable threat against conspecifics     

Sergio F  Blas J  Blanco G  Tanferna A  López L  Lemus JA  Hiraldo F 《Science (New York, N.Y.)》2011,331(6015):327-330

Individual quality is often signaled by phenotypic flags, such as bright plumage patches in birds. Extended phenotype signals can similarly show quality, but in these cases the signals are external to the individual, often taking the form of objects scavenged from the environment. Through multiple manipulative experiments, we showed that objects used for nest decoration by a territorial raptor, the black kite (Milvus migrans), act as reliable threats to conspecifics, revealing the viability, territory quality, and conflict dominance of the signaler. Our results suggest that animal-built structures may serve as signaling devices much more frequently than currently recognized.  相似文献   

Laboratory simulation of volcano seismicity     

Benson PM  Vinciguerra S  Meredith PG  Young RP 《Science (New York, N.Y.)》2008,322(5899):249-252

The physical processes generating seismicity within volcanic edifices are highly complex and not fully understood. We report results from a laboratory experiment in which basalt from Mount Etna volcano (Italy) was deformed and fractured. The experiment was monitored with an array of transducers around the sample to permit full-waveform capture, location, and analysis of microseismic events. Rapid post-failure decompression of the water-filled pore volume and damage zone triggered many low-frequency events, analogous to volcanic long-period seismicity. The low frequencies were associated with pore fluid decompression and were located in the damage zone in the fractured sample; these events exhibited a weak component of shear (double-couple) slip, consistent with fluid-driven events occurring beneath active volcanoes.  相似文献   

Differential lysosomal proteolysis in antigen-presenting cells determines antigen fate   总被引：2，自引：0，他引：2  

Delamarre L  Pack M  Chang H  Mellman I  Trombetta ES 《Science (New York, N.Y.)》2005,307(5715):1630-1634

Antigen-presenting cells (APCs) internalize antigens and present antigen-derived peptides to T cells. Although APCs have been thought to exhibit a well-developed capacity for lysosomal proteolysis, here we found that they can exhibit two distinct strategies upon antigen encounter. Whereas macrophages contained high levels of lysosomal proteases and rapidly degraded internalized proteins, dendritic cells (DCs) and B lymphocytes were protease-poor, resulting in a limited capacity for lysosomal degradation. Consistent with these findings, DCs in vivo degraded internalized antigens slowly and thus retained antigen in lymphoid organs for extended periods. Limited lysosomal proteolysis also favored antigen presentation. These results help explain why DCs are able to efficiently accumulate, process, and disseminate antigens and microbes systemically for purposes of tolerance and immunity.  相似文献