Nonculturability of the pathogenic Vibrio parahaemolyticus in live culture of Grateloupia turuturu is associated with bacterial attachment to the algal thalli

The invasive red alga Grateloupia turuturu Yamada could turn Vibrio parahaemolyticus into nonculturable state in live algal culture.In order to elucidate the mechanism of such an effect,a series of culture experiments were performed in this investigation based on three hypothesized causes,namely bacterial attachment,production of reactive oxygen species （ROS） and the discharge of water soluble secondary metabolic compounds.The results reveal that attachment to the thallus surface of G.turuturu was the major reason for the decrease of V.parahaemolyticus in seawater.Further investigations show that V.parahaemolyticus attachment to the surface of algal thallus in live cultures of seaweeds was a common phenomenon.However,the disappearance of the culturability of V.parahaemolyticus occurred only on the thallus of G.turuturu over 72 h among all six algal species tested.Electron microscopic scanning shows that most of V.parahaemolyticus attached to G.turuturu changed from the initial normal bacilli to coccoid-shape after 72 h.The enclosure experiments by enclosing the algal thallus in tubes demonstrate that the nonculturability of V.parahaemolyticus in the water of live culture of G.turuturu occurred after the physical contact of the V.parahaemolyticus to the alga.The capacity of G.turuturu in affecting the culturability of V.parahaemolyticus was not influenced after inhibition of photosynthesis by treatment of 3（3,4dichlorophenyl）-1 ,1dimethyl urea （DCMU） at non-lethal levels.Production of reactive oxygen species after addition of live culture of bacteria was excluded by on-line analyzing the oxidation of dichlorohydrofluorescein （DCFH） to dichlorofluorescein （DCF） in the presence of peroxidase on a VersaFluor fluorometer.

Applications of Three DNA Barcodes in Assorting Intertidal Red Macroalgal Flora in Qingdao, China

This study is part of the endeavor to construct a comprehensive DNA barcoding database for common seaweeds in China. Identifications of red seaweeds, which have simple morphology and anatomy, are sometimes difficult solely depending on morphological characteristics. In recent years, DNA barcode technique has become a more and more effective tool to help solve some of the taxonomic difficulties. Some DNA markers such as COI (cytochrome oxidase subunitⅠ) are proposed as standardized DNA barcodes for all seaweed species. In this study, COI, UPA (universal plastid amplicon, domain V of 23S rRNA), and ITS (nuclear internal transcribed spacer) were employed to analyze common species of intertidal red seaweeds in Qingdao (119.3 -121 E, 35.35 -37.09 N). The applicability of using one or a few combined barcodes to identify red seaweed species was tested. The results indicated that COI is a sensitive marker at species level. However, not all the tested species gave PCR amplification products due to lack of the universal primers. The second barcode UPA had effective universal primers but needed to be tested for the effectiveness of resolving closely related species. More than one ITS sequence types were found in some species in this investigation, which might lead to confusion in further analysis. Therefore ITS sequence is not recommended as a universal barcode for seaweeds identification.

Circadian rhythms in the growth and reproduction of the brown alga Undaria pinnatifida and gametogenesis under different photoperiods

Circadian growth rhythm of the juvenile sporophyte of the brown alga Undaria pinnatifida was measured with the computer-aided image analysis system in constant florescent white light under constant temperature （ 10 ℃ ）. The growth rhythm persisted for 4 d in constant light with a free-running period of 25.6 h. Egg release from filamentous gametophytes pre-cultured in the light - dark regime was evaluated for six consecutive days at fixed time intervals in constant white light and 12 h light per day. Egg release rhythm persisted for 3 d in both regimes, indicating the endogenous nature. Temporal scale of egg release and gametogenesis in 18, 16, 12 and 8 h light per day were evaluated respectively using vegetatively propagated filamentous gametophytes. Egg release occurred 2 h after the onset of dark phase and peaked at midnight. Evaluation of the rates of oogonium formation, egg release or fertilization revealed no significant differences in four light-dark regimes, indicating the great plasticity of sexual reproduction. No photoperiodic effect in gametogenesis in terms of oogonium formation and egg release was found, but fertilization in short days was significantly higher than in long days. Results of this investigation further confirmed the general occurrence of circadian rhythms in intertidal seaweed species.

Production and Characterization of Monoclonal Antibodies to Bluetongue Virus

In the present study,a total of 24 MAbs were produced against bluetongue virus (BTV) by polyethyleneglycol (PEG) mediated fusion method using sensitized lymphocytes and myeloma cells. All these clones were characterized for their reactivity to whole virus and recombinant BTV-VP7 protein,titres,isotypes and their reactivity with 24 BTV-serotype specific sera in cELISA. Out of 24 clones,a majority of them (n = 18) belong to various IgG subclasses and the remaining (n = 6) to the IgM class. A panel of eight clones reactive to both whole BTV and purified rVP7 protein were identified based on their reactivity in iELISA. For competitive ELISA,the clone designated as 4A10 showed better inhibition to hyperimmune serum of BTV serotype 23. However,this clone showed a variable percent of inhibition ranging from16.6% with BTV 12 serotype to 78.9% with BTV16 serotype using 24 serotype specific sera of BTV originating from guinea pig at their lowest dilutions. From the available panel of clones,only 4A10 was found to have a possible diagnostic application.

Cultural Nourishment for the Development of Chinese Medicine

Medicine,especially traditional Chinese medicine,is by no means a single level of knowledge system and operational skills,blit is frill of humanistic color,encompassing natural science and social science,medical theory and traditional culture.Traditional Chinese medicine is rooted in the splendid traditional culture of China,and its theoretical exploration methods and explanations are based on the historical and colorful traditional Chinese culture.This article will give advice on the irrigation and nourishment of traditional culture.

Periodic exposure to ambient solar irradiance benefits the growth of juvenile seedlings of Hizikia fusiformis

In our trials, from 2007 to 2008, of mass production of seedlings of Hizikia fusiformis using synchronization techniques, problems of a "dark thalli" phenomenon and epiphytes contamination severely threatened the health of juvenile seedlings. In this investigation, we optimized conditions for improving the growth of juvenile seedlings. Seven string collectors were seeded with zygotes and a series of experiments were conducted including direct exposure to solar irradiance, co-culture with Ulva spp. and treatment with sodium hypochlorite. It was found that direct exposure to solar irradiance (maximum: 1 740 μmol photons/(m2?s)) for 2 h per day could efficiently enhance the growth of young seedlings and simultaneously inhibit the growth of epiphytic algae. In this treatment, 50-day old seedlings could reach an average of 0.44 cm in length and possess up to nine leaflets. However, a single treatment with 18-mmol/L sodium hypochlorite for 10 min severely harmed 15-day old seedlings. In comparison, weekly treatment with 2.2-mmol/L sodium hypochlorite for 10 min brought no apparent harm to seedlings and eliminated epiphytic algae efficiently. However, this treatment significantly increased the detachment rate of seedlings. Inoculating Ulva spp. onto the collector caused a dramatic decrease in the number of seedlings. However, the growth of the remaining seedlings appeared unhampered. All collectors except the control were daily sprayed with a high pressure water jet from the 8th day post fertilization. From the first day to 50th day, no "dark thallus" was observed on any of the seven collectors. We believe that well-timed daily exposure to solar irradiance would favor H. fusiformis in its early growing stages.

Evaluation of Efficacy of Stabilizers on the Thermostability of Live Attenuated Thermo-adapted Peste des petits ruminants Vaccines

In this study,thermo-adapted (Ta) PPR vaccines were assessed for their stability at 25,37,40,42 and 45℃ in lyophilized form using two extrinsic stabilizers {lactalbumin hydrolysate-sucrose (LS) and stabilizer E} and in reconstituted form with the diluents (1 mol/L MgSO4 or 0.85% NaCl).The lyophilized vaccines showed an expiry period of 24-26 days at 25℃,7-8 days at 37℃ and 3-4 days at 40℃.LS stabilizer was superior at 42℃ with a shelf-life of 44 h,whereas in stabilizer E,a 40 h shelf-life with a comparable half-life was observed.At 45℃,the half-life in stabilizer E was better than LS and lasted for 1 day.Furthermore,the reconstituted vaccine maintained the titre for 48 h both at 4℃ and 25℃ and for 24-30 h at 37℃.As both the stabilizers performed equally well with regard to shelf-life and half-life,the present study suggests LS as stabilizer as a choice for lyophilization with 0.85% NaCl diluent,because it has better performance at higher temperature.These Ta vaccines can be used as alternatives to existing vaccines for the control of the disease in tropical countries as they are effective in avoiding vaccination failure due to the breakdown in cold-chain maintenance,as this vaccine is considerably more stable at ambient temperatures.

The Rise and Fall of Overseas Chinese Problem in the Early Republic of China

In the late Qing Dynasty and the early R epublic of China,foreign invasion made China suffer from an unprecedented humiliation,and the W estern powers initiated a commercial intrusion by forcing China to sign unequal treaties and open treaty ports. From this perspective,a deep exploration is made to study the corresponding influence and its function. The rule shows that the developing route of national politics,economy and culture can determine the trend of the development of overseas Chinese problem; in addition,it objectively reflects that the social nature is vital to overseas Chinese problem.

Biological identification and determination of optimum growth conditions for four species of Navicula

Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning elec-tron microscopy （SEM） and sequence comparisons of two segments of genes （small ribosomal subunit and large subunit of Rubisco）, the species were identified asNavicula perminuta,N. pseudacceptata,N. vara, andN. rhynchocephala. Based on phylogenetic analysis and culture trials,there was a close relationship betweenN. perminutaandN. vara. Growth of these species was evaluated using measurements of optical density at 680 nm （OD680） under various environmental factors. Results showed that the optimum culture conditions were 25°C, 50-100 μmol photons m-2 s-1, pH 8.0, and salinities from 25 to 30. However, the favor-able salinity forN. perminuta was surprisingly high at 35. Nutrient requirement analysis demonstrated that growth ofNavicula depended on the availability of SiO32-. Their relative growth rates （RGR） peaked at the highest tested level （0.25 mmol/L）. The optimal concentrations of NO3-and PO43- were 3.6 mmol/L and 0.18 mmol/L, respectively. Culture of theseNavicula species for abalone or sea cucumber aquaculture should take these factors into consideration.

Effect of Different Plant Growth Promoting Rhizobacteria on Maize Seed Germination and Seedling Development

Our study aimed at assessing the effects of 3 Plants Growth Promoting Rhizobacteria (PGPR) either singly or in combination on maize growth under laboratory and greenhouse conditions. Seeds were inoculated with single and combined solution of 108 CFU/ml of Rhizobacteria. Seeds were not inoculated for the control variant. The highest germination percentage was obtained with the combination of Pseudomonas fluorescens and Pseudomonas putida. This combination also recorded the best vigor index, plants circumferences number of leaves and the leaf area. The maximal heights of plants were observed with seeds treated with Azospirillum lipoferum with an increase of 37.32%. The highest rates of underground dry matter were recorded with A. lipoferum, with an increase of more than 56% comparative to control, while the combination P. fluorescens and P. putida increased the aerial dry matter of 59.11%. Finally, the highest value of the aerial biomass was obtained with the plants treated with the combination of P. fluorescens and P. putida and the highest underground biomass was obtained with plants treated only with A. lipoferum. These results suggest that specific combinations of PGPR can be considered as efficient alternative biofertilizers to promote maize seed germination, biomass and crop yield.

Deep learning methods for biotic and abiotic stresses detection and classification in fruits and vegetables:State of the art and perspectives

Deep Learning(DL),a type of Machine Learning,has gained significant interest in many fields,including agriculture.This paper aims to shed light on deep learning techniques used in agriculture for abiotic and biotic stress detection in fruits and vegetables,their benefits,and the challenges faced by users.Scientific papers were collected from Web of Science,Scopus,Google Scholar,Springer,and Directory of Open Access Journals(DOAJ)using combinations of specific keywords such as:’Deep Learning’OR’Artificial Intelligence’in combination with fruit disease’,vegetable disease’,‘fruit stress',OR‘vegetable stress'following PRISMA guidelines.From the initial 818 papers identified using the keywords,132 were reviewed after excluding books,reviews,and the irrelevant.The recovered scientific papers were from 2003 to 2022;93%addressed biotic stress on fruits and vegetables.The most common biotic stresses on species are fungal diseases(grey spots,brown spots,black spots,downy mildew,powdery mildew,and anthracnose).Few studies were interested in abiotic stresses(nutrient deficiency,water stress,light intensity,and heavy metal contamination).Deep Learning and Convolutional Neural Networks were the most used keywords,with GoogleNet(18.28%),ResNet50(16.67%),and VGG16(16.67%)as the most used architectures.Fifty-two percent of the data used to compile these models come from the fields,followed by data obtained online.Precision problems due to unbalanced classes and the small size of some databases were also analyzed.We provided the research gaps and some perspectives from the reviewed papers.Further research works are required for a deep understanding of the use of machine learning techniques in fruit and vegetable studies:collection of large datasets according to different scenarios on fruit and vegetable diseases,evaluation of the effect of climatic variability on the fruit and vegetable yield using AI methods and more abiotic stress studies.

The evolution of George Town’s urban morphology in the Straits of Malacca,late 18th century-early 21st century

George Town is a significant World Heritage Site in the Straits of Malacca.This paper examined the evolution of urban morphology in George Town within geography,politics,economy,and culture in a horizontal dimension and layer upon layer in a vertical dimension.In this study,to ensure the objectives are achieved,qualitative methods will be applied including several approaches such as literature review,interpretation of archives chronologically,maps study,census returns,trade directories,photographs and postcards,and urban master plan study.The research is based on the analysis of urban construction,land use,economic development,and municipal policies.First,study the urban morphology in a specific period,and construct the inner layer structure in each period.Second,an analogy is drawn among the evolution of the urban morphology by time-scale,this section focusses on the historical conjunctures and events related to the urban construction.An important contribution can be made to the conservation and management of urban built heritage in George Town,on the one hand,explaining the evolution of urban morphology by examining George Tow nphysical and spatial environment,and in turn,on the other hand,understanding about the physical and spatial environment by examining the urban morphology.

听说示证的类型及其语义特征——以藏缅语、南岛语为例

本文考察听说示证作为语法范畴在中国境内藏缅语、南岛语中的类型及其语义特征。藏缅语具有间接、引用、报道等示证,南岛语只有报道示证;藏缅语分二手信息和三手信息,南岛语不区分;藏缅语听说示证的语法手段有添加附缀、词缀和小品词,南岛语则只添加附缀示证标记;南岛语有非命题性听说示证,藏缅语没有;藏缅语和南岛语的听说示证都有语法义和语用义。