Multivariate analysis of fresh-cut carambola slices stored under different temperatures     

Gustavo H.A. Teixeira  José F. DuriganAntônio S. Ferraudo  Ricardo E. AlvesTimothy J. O’Hare 《Postharvest Biology and Technology》2012,63(1):91-97

Quality of fresh-cut carambola (Averrhoa carambola L.) is related to many chemical and biochemical variables especially those involved with softening and browning, both influenced by storage temperature. To study these effects, a multivariate analysis was used to evaluate slices packaged in vacuum-sealed polyolefin bags, and stored at 2.5 °C, 5 °C and 10 °C, for up to 16 d. The quality of slices at each temperature was correlated with the duration of storage, O₂ and CO₂ concentration in the package, physical chemical constituents, and activity of enzymes involved in softening (PG) and browning (PPO) metabolism. Three quality groups were identified by hierarchical cluster analysis, and the classification of the components within each of these groups was obtained from a principal component analysis (PCA). The characterization of samples by PCA clearly distinguished acceptable and non-acceptable slices. According to PCA, acceptable slices presented higher ascorbic acid content, greater hue angles (°h) and final lightness (L-5) in the first principal component (PC1). On the other hand, non-acceptable slices presented higher total pectin content, PPO activity in the PC1. Non-acceptable slices also presented higher soluble pectin content, increased pectin solubilisation and higher CO₂ concentration in the second principal component (PC2) whereas acceptable slices showed lower total sugar content. The hierarchical cluster and PCA analyses were useful for discriminating the quality of slices stored at different temperatures.  相似文献   

High-resolution protein structure determination by serial femtosecond crystallography     

Boutet S  Lomb L  Williams GJ  Barends TR  Aquila A  Doak RB  Weierstall U  DePonte DP  Steinbrener J  Shoeman RL  Messerschmidt M  Barty A  White TA  Kassemeyer S  Kirian RA  Seibert MM  Montanez PA  Kenney C  Herbst R  Hart P  Pines J  Haller G  Gruner SM  Philipp HT  Tate MW  Hromalik M  Koerner LJ  van Bakel N  Morse J  Ghonsalves W  Arnlund D  Bogan MJ  Caleman C  Fromme R  Hampton CY  Hunter MS  Johansson LC  Katona G  Kupitz C  Liang M  Martin AV  Nass K  Redecke L  Stellato F  Timneanu N  Wang D  Zatsepin NA  Schafer D  Defever J 《Science (New York, N.Y.)》2012,337(6092):362-364

Structure determination of proteins and other macromolecules has historically required the growth of high-quality crystals sufficiently large to diffract x-rays efficiently while withstanding radiation damage. We applied serial femtosecond crystallography (SFX) using an x-ray free-electron laser (XFEL) to obtain high-resolution structural information from microcrystals (less than 1 micrometer by 1 micrometer by 3 micrometers) of the well-characterized model protein lysozyme. The agreement with synchrotron data demonstrates the immediate relevance of SFX for analyzing the structure of the large group of difficult-to-crystallize molecules.  相似文献   

Synthetic genetic polymers capable of heredity and evolution     

Pinheiro VB  Taylor AI  Cozens C  Abramov M  Renders M  Zhang S  Chaput JC  Wengel J  Peak-Chew SY  McLaughlin SH  Herdewijn P  Holliger P 《Science (New York, N.Y.)》2012,336(6079):341-344

Genetic information storage and processing rely on just two polymers, DNA and RNA, yet whether their role reflects evolutionary history or fundamental functional constraints is currently unknown. With the use of polymerase evolution and design, we show that genetic information can be stored in and recovered from six alternative genetic polymers based on simple nucleic acid architectures not found in nature [xeno-nucleic acids (XNAs)]. We also select XNA aptamers, which bind their targets with high affinity and specificity, demonstrating that beyond heredity, specific XNAs have the capacity for Darwinian evolution and folding into defined structures. Thus, heredity and evolution, two hallmarks of life, are not limited to DNA and RNA but are likely to be emergent properties of polymers capable of information storage.  相似文献   

Maximizing endangered species research     

DK Rosenberg  DG Vesely  JA Gervais 《Science (New York, N.Y.)》2012,337(6096):799

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A distinct role of the temporal-parietal junction in predicting socially guided decisions     

RM Carter  DL Bowling  C Reeck  SA Huettel 《Science (New York, N.Y.)》2012,337(6090):109-111

To make adaptive decisions in a social context, humans must identify relevant agents in the environment, infer their underlying strategies and motivations, and predict their upcoming actions. We used functional magnetic resonance imaging, in conjunction with combinatorial multivariate pattern analysis, to predict human participants' subsequent decisions in an incentive-compatible poker game. We found that signals from the temporal-parietal junction provided unique information about the nature of the upcoming decision, and that information was specific to decisions against agents who were both social and relevant for future behavior.  相似文献   

Food sovereignty, urban food access, and food activism: contemplating the connections through examples from Chicago   总被引：1，自引：0，他引：1  

Daniel R. Block  Noel Chávez  Erika Allen  Dinah Ramirez 《Agriculture and Human Values》2012,29(2):203-215

The idea of food sovereignty has its roots primarily in the response of small producers in developing countries to decreasing levels of control over land, production practices, and food access. While the concerns of urban Chicagoans struggling with low food access may seem far from these issues, the authors believe that the ideas associated with food sovereignty will lead to the construction of solutions to what is often called the ??food desert?? issue that serve and empower communities in ways that less democratic solutions do not. In Chicago and elsewhere, residents and activists often see and experience racial and economic inequalities through the variety of stores and other food access sites available in their community. The connections between food access, respect, and activism are first considered through a set of statements of Chicagoans living in food access poor areas. We will then discuss these connections through the work and philosophy of activists in Chicago centered in food sovereignty and food justice. Particular focus will be placed on Growing Power, an urban food production, distribution, and learning organization working primarily in Milwaukee and Chicago, and Healthy South Chicago, a community coalition focused on health issues in a working class area of the city.  相似文献   

Attributes of clinical role models as described by senior veterinary students in Australia     

Schull DN  Kyle GJ  Coleman GT  Mills PC 《Journal of veterinary medical education》2012,39(3):263-266

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Preparing students for careers in food-supply veterinary medicine: a review of educational programs in the United States     

Posey RD  Hoffsis GF  Cullor JS  Naylor JM  Chaddock M  Ames TR 《Journal of veterinary medical education》2012,39(3):257-262

The real and/or perceived shortage of veterinarians serving food-supply veterinary medicine has been a topic of considerable discussion for decades. Regardless of this debate, there are issues still facing colleges of veterinary medicine (CVMs) about the best process of educating future food-supply veterinarians. Over the past several years, there have been increasing concerns by some that the needs of food-supply veterinary medicine have not adequately been met through veterinary educational institutions. The food-supply veterinary medical curriculum offered by individual CVMs varies depending on individual curricular design, available resident animal population, available food-animal caseload, faculty, and individual teaching efforts of faculty. All of the institutional members of the Association of American Veterinary Medical Colleges (AAVMC) were requested to share their Food Animal Veterinary Career Incentives Programs. The AAVMC asked all member institutions what incentives they used to attract and educate students interested in, or possibly considering, a career in food-supply veterinary medicine (FSVM). The problem arises as to how we continue to educate veterinary students with ever shrinking budgets and how to recruit and retain faculty with expertise to address the needs of society. Several CVMs use innovative training initiatives to help build successful FSVM programs. This article focuses on dairy, beef, and swine food-animal education and does not characterize colleges' educational efforts in poultry and aquaculture. This review highlights the individual strategies used by the CVMs in the United States.  相似文献   

Efficacy of albendazole and moxidectin and resistance to ivermectin against Libyostrongylus douglassii and Libyostrongylus dentatus in ostriches     

de Souza LP  Lelis RT  Granja IR  Damatta RA  Santos Cde P 《Veterinary parasitology》2012,189(2-4):387-389

Anthelmintic resistance has emerged globally as a problem amongst nematode of livestock and has been particularly well documented in equine and small ruminants. There are no studies regarding the efficacy of anthelmintics against the hematophagous nematodes in ostriches, Libyostrongylus dentatus; and just a few on L. douglassii. Here the efficacy of albendazole, ivermectin and moxidectin were evaluated against these two species in an ostrich farm in Minas Gerais state, Brazil. The feces were collected on the day of treatment and after 13days of an oral dose of albendazole (6mg/kg), or an injected dose (0.2mg/kg) of ivermectin or moxidectin. The fecal egg count reduction test and coprocultures were performed to determine possible resistance against the drugs used. An efficacy of 60% was found for ivermectin, while albendazole and moxidectin were 100% effective. Both worm species appeared to have reduced sensitivity to ivermectin.  相似文献   

Humoral and cellular immune responses in pigs immunized intranasally with crude rhoptry proteins of Toxoplasma gondii plus Quil-A     

da Cunha IA  Zulpo DL  Bogado AL  de Barros LD  Taroda A  Igarashi M  Navarro IT  Garcia JL 《Veterinary parasitology》2012,186(3-4):216-221

We evaluated the humoral and cellular immune responses in pigs immunized intranasally with crude rhoptry proteins of Toxoplasma gondii plus Quil-A. The experiment used 13 mixed-breed pigs divided into the following three groups: G1 (vaccinated-challenged, n=6), which received the rhoptry vaccine (200(g/dose); G2 (adjuvant-challenged, n=4), which received PBS plus Quil-A; and G3 (unvaccinated-challenged, n=3), which was the control group. The treatments were performed intranasally at days 0, 21, and 42. Three pigs from G1 produced IgG and IgM antibody levels above the cut-off in the ELISA on the challenge day. Partial protection was observed in G1 at the chronic phase of infection when compared with G3. The preventable fractions were 41.6% and 6.5%, in G1 and G2, respectively. The results of this study suggest that rhoptry proteins plus Quil-A stimulated humoral, local, and systemic immune responses, which were able to partially protect the brain from cyst formation.  相似文献