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Search Results: 1 - 10 of 210698 matches for " Virginia L. Barraquio "
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Lactic Acid and Probiotic Bacteria from Fermented and Probiotic Dairy Products
B.K.L. Karna,Virginia L. Barraquio,O. C. Emata
Science Diliman , 2007,
Abstract: Lactic acid and probiotic bacteria were enumerated and isolated from commercially available yoghurt andprobiotic milk products. Lactobacillus delbrueckii ssp. bulgaricus were enumerated and isolated usingMRS agar incubated anaerobically at 37oC for 72 hrs. M17 agar was used for the enumeration andisolation of Streptococcus thermophilus incubated aerobically at 37oC for 48 hrs. MRS agar and modifiedMRS agar (MRS + L-cysteine + LiCl + Na propionate) were used for the enumeration and isolation ofprobiotic bacteria. Both were incubated anaerobically at 37oC for 72 hrs. Morphological, physiologicaland biochemical reactions were used to characterize the isolates.Str. thermophilus counts ranged from 2.6 x 1011 to 2.9 x 1020 CFU/g with Fruit Yoghurt (FY) having thehighest count and Yoghurt Natural (YN) with the lowest count. Highest Lactobacillus delbrueckii ssp.bulgaricus count was obtained in Duo Yoghurt (DY), 1.1 x 109 and lowest in Yoghurt Drink (YD), 8.0 x 107CFU/g. The highest probiotic bacterial count of 2.3 x 108 was obtained in Yakult (YK) and Neslac (Nes)showed the lowest, 1.6 x 102 CFU/g. The viable counts of all the products examined met the prescribedminimum viable count of 105 to 106CFU/g for the claimed health benefits for the consumer except forChamyto Plain (CP), Nes and Nan-2 (Nan).Morphological, physiological and biochemical characteristics showed that the following genera andspecies were present Pediococcus acidilactici (YN), P. pentosaceus (FY), Lactobacillus delbrueckiidelbrueckii and L. brevis in Non Fat High Calcium Yoghurt (NC), L. acidophilus and L. delbrueckiidelbrueckii (DY, YD), P. damnosus and P. pentosaceus in Chamyto Orange (CO), L. delbrueckii bulgaricus,L. acidophilus, and L. delbrueckii delbrueckii (CP), L. para. paracasei (YK) and Bifidobacterium ssp.(Nes and Nan).Of the 28 isolates characterized in this study, 15 were Lactobacillus (5 species), 5 werePediococcus (3 species), 6 were Bifidobacterium (species not identified), and 2 were Actinomyces israelii(1 species)
Characterization of Mercury and Its Risk in Nelson’s, Saltmarsh, and Seaside Sparrows
Virginia L. Winder
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0044446
Abstract: Background Nelson’s, Saltmarsh, and Seaside Sparrows (Ammodramus nelsoni, A. caudacutus, and A. maritimus, respectively) depend on marsh and wetland habitats – ecosystems in which mercury (Hg) bioavailability is notoriously high. The purpose of the present study was to address the potential impact of Hg on these species using first primary and breast feathers as non-destructive biomonitoring tools. Methods and Principal Findings Feathers were sampled from wintering sparrows in North Carolina salt marshes (2006–2010). Feather Hg data were used in three risk analysis components (1) Threshold Component – examined feather Hg with regard to published negative effects thresholds; (2) Hg Dynamics Component – examined Hg in sparrows captured multiple times; and (3) Capture Frequency and Survival Component – tested for links between Hg and return frequency and survival. Threshold Component analyses indicated that Hg concentrations in 42–77% of sampled individuals (breast feather n = 879; first primary feather n = 663) were within the range associated with decreased reproduction in other avian species. Hg Dynamics Component analyses demonstrated that Hg increased between first and second captures for Nelson’s (n = 9) and Seaside Sparrows (n = 23). Capture Frequency and Survival Component analyses detected a negative relationship between Hg and capture frequency in Nelson’s Sparrows (n = 315). However, MARK models detected no effect of Hg on apparent survival in any species. Conclusion and Significance This study indicates that current Hg exposure places a considerable proportion of each population at risk. In particular, 52% of all sampled Saltmarsh Sparrows exhibited first primary feather Hg concentrations exceeding those associated with a >60% reduction in reproductive success in other species. This study reports evidence for net annual bioaccumulation, indicating an increased risk in older individuals. These data can be used to inform future population assessments and management for these species.
Lenguajes de valoración y conflictos territoriales en el campo argentino: reflexiones en torno a la producción de agrocombustibles
Virginia Toledo López
Desenvolvimento e Meio Ambiente , 2010,
Abstract: The paper proposes an approach to the study of the language of valuation present in contemporary social actors of Argentine’s rural sector. This will allow a further reflection on the differing strategies of appropriation that they implemented in their territories and their consideration in the perspective of sustainability. Thus, from primary and secondary sources, we will try to analyze the valuation criteria of Nature for different actors (popular organizations and promoters of agrofuels).
Aplicación de HACCP en la elaboración de jamón crudo
Virginia L. Cousté
Invenio , 2001,
Abstract: El objetivo de este artículo es explicar qué es el sistema de asegu-ramiento de lacalidad llamado HACCP (Hazard Analysis Critical Control Points) y cómo se aplicó su análi-sis a la elaboración de jamón crudo. Como resultado del mismo se identificaron tres PCC(Puntos Críticos de Control) en las etapas de salazón, escurrido (presecado) y secado
Discovering Multicultural Connections
Virginia L. Driggers
Colonial Academic Alliance Undergraduate Research Journal , 2011,
Abstract: The context of this research took place at an art center in Midlothian, Virginia, ArtAdventures, and a school in the rural highlands of Guatemala, Chuicavioc, where the students took part in the same small art course incorporating the themes of culture, recycling and time. In this project the students were to exchange works of art and follow the exact same lessons, guideline, criteria and expectations.The power of cultural communication and appreciation lies in the teacher’s hands as they conduct an Art Exchange. However when produced rapidly with poor communication and expectations to the projects a group of students might just as quickly lose appreciation for another culture. The importance of researching how to create an exemplary model for Art Exchanges is necessary for those teachers who wish to bring little bias, student discovery, art and multiculturalism to the classroom.
Zebrafish Reproduction: Revisiting In Vitro Fertilization to Increase Sperm Cryopreservation Success
Mary Hagedorn,Virginia L. Carter
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0021059
Abstract: Although conventional cryopreservation is a proven method for long-term, safe storage of genetic material, protocols used by the zebrafish community are not standardized and yield inconsistent results, thereby putting the security of many genotypes in individual laboratories and stock centers at risk. An important challenge for a successful zebrafish sperm cryopreservation program is the large variability in the post-thaw in vitro fertilization success (0 to 80%). But how much of this variability was due to the reproductive traits of the in vitro fertilization process, and not due to the cryopreservation process? These experiments only assessed the in vitro process with fresh sperm, but yielded the basic metrics needed for successful in vitro fertilization using cryopreserved sperm, as well. We analyzed the reproductive traits for zebrafish males with a strict body condition range. It did not correlate with sperm volume, or motility (P>0.05), but it did correlate with sperm concentration. Younger males produced more concentrated sperm (P<0.05). To minimize the wastage of sperm during the in vitro fertilization process, 106 cells/ml was the minimum sperm concentration needed to achieve an in vitro fertilization success of ≥ 70%. During the in vitro process, pooling sperm did not reduce fertilization success (P>0.05), but pooling eggs reduced it by approximately 30 to 50% (P<0.05). This reduction in fertilization success was due not to the pooling of the females' eggs, but to the type of tools used to handle the eggs. Recommendations to enhance the in vitro process for zebrafish include: 1) using males of a body condition closer to 1.5 for maximal sperm concentration; 2) minimizing sperm wastage by using a working sperm concentration of 106 motile cells/ml for in vitro fertilization; and 3) never using metal or sharp-edged tools to handle eggs prior to fertilization.
分析化学 , 1985,
Abstract: 捕集和富集挥发性化合物近来已成为制备试样的一种标准方法[1,2],但很少用以取得法庭物证。在文献报导的几乎所有应用中,都是将小量挥发性化合物捕集在过量的吸附剂上,但在物证中挥发物的量很容易超过吸附剂的容量,使试样失去代表性。
Spanish-Language Home Visitation to Disadvantaged Latino Preschoolers: A Means of Promoting Language Development and English School Readiness  [PDF]
Virginia Mann
Creative Education (CE) , 2014, DOI: 10.4236/ce.2014.56051

This study reports five years of a school readiness intervention called “HABLA” (Home Based Activities Building Language Acquisition), designed to increase and enrich speech and literacy activities in the homes of economically and educationally disadvantaged Latino families with children between the age of 2 and 4. A team of trained home visitors provided two years of a 23-week program of visitation in which they met with parent(s) and child twice weekly. Both years presented a Spanish language adaptation of the parent-child home program model; home visitors provide intensive modeling and coaching of non-directive Spanish language use, conversation, and literacy activities. Administration of the PLS-3 in Spanish at the onset and culmination of each year of the program indicates significant increases in receptive and expressive language for each year of visitation (7.8 standard points for the first year, 4.4 for the second) with effect-size r ranging from .24 to 42. Participants had significantly improved their levels of oral Spanish skill and scored much higher than a comparison group of non-treated. A subset of graduates of the two-year program was tested as kindergarteners; they showed a continued advantage over a comparison group of 18 peers who had not received the intervention. For the graduates, both their Spanish PLS-3 scores and English PLS-4 scores were significantly higher, and their parents reported a continued effort to provide literacy experiences at home. The HABLA participants also showed a clear advantage for an English language test of phonological awareness, one of the strongest predictors of school success.

Mercury in Nelson's Sparrow Subspecies at Breeding Sites
Virginia L. Winder, Steven D. Emslie
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0032257
Abstract: Background Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni) use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. Methodology/Principal Findings From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick) and sampled breast feathers, the first primary feather (P1), and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84±0.37 to 1.65±1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (P<0.01). Breast feather mercury did not vary among sites within a given sampling year (site means ranged from 0.98±0.69 to 2.71±2.93 ppm). Mean P1 mercury in alterus (2.96±1.84 ppm fw) was significantly lower than in any other sampled population (5.25±2.24–6.77±3.51 ppm; P≤0.03). Conclusions/Significance Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure.
Deep sequencing-based analysis of the anaerobic stimulon in Neisseria gonorrhoeae
Vincent M Isabella, Virginia L Clark
BMC Genomics , 2011, DOI: 10.1186/1471-2164-12-51
Abstract: We determined that 198 chromosomal genes were differentially expressed (~10% of the genome) in response to anaerobic conditions. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Validation of RNA-seq data using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. We also determined that many genes found to be responsive to anaerobiosis have also been shown to be responsive to iron and/or oxidative stress.Gonococci will be subject to many forms of environmental stress, including oxygen-limitation, during the course of infection. Here we determined that the anaerobic stimulon in gonococci was larger than previous studies would suggest. Many new targets for future research have been uncovered, and the results derived from this study may have helped to elucidate factors or mechanisms of virulence that may have otherwise been overlooked.N. gonorrhoeae was long considered to be an obligate aerobe until it was discovered that anaerobic growth was possible when nitrite or nitric oxide (NO) was used as a terminal electron acceptor [1,2]. Anaerobic growth is accomplished through utilization of a truncated denitrification pathway, which is encoded within the gonococcal genome as a pair of divergently transcribed genes, aniA, encoding a nitrite reductase, and norB, encoding a nitric oxide reductase [3,4]. Anaerobiosis is presumed to be a physiologically significant state during infection, as the gonococcus is often recovered from infected individuals in co-culture with obligate anaerobes such as Peptococcus and Bacteroides spp. [5]. Furthermore, gonococci have been shown to induce and repress the exp
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